Tesi sul tema "Human dispersal"

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1

Banha, Filipe Miguel Santos. "Human dispersal of freshwater invasive fauna". Doctoral thesis, Universidade de Évora, 2016. http://hdl.handle.net/10174/18152.

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The main goal of this thesis was to improve the knowledge on the mechanisms involved on Human dispersal of freshwater invasive fauna, contributing for the management of these problematic species. Several vectors were investigated, both accidental and intentional, from a freshwater invaders list that included some of the worse species. It was found that the red swamp crayfish and the signal crayfish presented desiccation survival capacities compatible with long-distance human-mediated dispersal. Off-road vehicles constituted a viable accidental vector for invasive macroinvertebrates, like the red swamp crayfish and the bladder snail. Live bait capture using dip nets and crayfish trapping constitute viable vectors for invasive freshwater macrofauna dispersal. The former is more related with accidental transport of small invasive organisms, and the latter is mostly related with intentional transport of invasive fish species. The importance of the angling web forums as a useful tool to help detection of non-native fish species was demonstrated with the first record of European Perch, a non-native fish in continental Portugal. Freshwater anglers from Portugal and Spain presented preference for invasive fish species, similar mobility, low incidence of live bait use and similar perception of biological freshwater invasions processes and impacts. Differences among countries were found for angler's activity patterns throughout the year and motivations for introductions. Zebra mussel larvae desiccation survival is compatible with long-distance overland dispersal. Its transport by natural vectors, like ducks, or human vectors like fishing tackle, such as waders and keep nets is viable. Yet, when comparing both types of vectors, fishing tackle presented a higher propensity to spread zebra mussel larvae than ducks; Dispersão de fauna invasiva dulçaquícola pelo Homem Resumo: O principal objetivo desta tese foi melhorar o conhecimento dos mecanismos envolvidos na dispersão de fauna dulçaquícola invasiva pelo homem, contribuindo assim para a gestão destas espécies problemáticas. Investigaram-se vários vetores, quer acidentais quer intencionais de uma lista de invasores dulçaquícolas que incluem algumas das piores espécies. Verificou-se que o lagostim vermelho e o lagostim sinal possuem uma capacidade de sobrevivência à dessecação compatível com a sua dispersão a longa distância pelo Homem. Os veículos todo-o-terreno constituem um vetor viável para macroinvertebrados invasivos como o lagostim vermelho e o caracol aquático. A captura de isco vivo com recurso a camaroeiro e o uso de armadilhas para a captura de lagostim constituem vetores viáveis de dispersão para a macrofauna dulçaquícola, sendo que o primeiro está relacionado com o transporte acidental de pequenos organismos invasores e o segundo com transporte intencional de peixes invasores. Através do primeiro registo em Portugal Continental de Perca-europeia, uma espécie não-nativa, demostrou-se a importância de fóruns on-line de pesca desportiva como uma ferramenta útil para a deteção de peixes não-nativos. Os pescadores dulçaquícolas de Portugal e Espanha apresentam preferência por espécies de peixes invasores, similar mobilidade, baixa incidência no uso de isco vivo e similar perceção dos processos e impactos das invasões biológicas dulçaquícolas. Detetaram-se diferenças entre países nos padrões de atividade dos pescadores durante o ano e na motivação para as introduções. A sobrevivência à dessecação de larvas de mexilhão-zebra é compatível com o seu transporte a longas distâncias fora de água, sendo viável o seu transporte quer por vetores naturais, como patos, quer humanos como equipamento de pesca, como botas altas e redes de retenção. No entanto, quando se comparam ambos os tipos de vetores, o equipamento de pesca apresenta maior propensão que os patos para dispersar larvas de mexilhão-zebra.
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2

Wasilwa, Noah Sitati. "Human-elephant conflict in the Masai Mara dispersal areas of Transmara District". Thesis, University of Kent, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399587.

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3

Davies, S. W. G. "The Aurignacian as a reflection of modern human population dispersal in Europe". Thesis, University of Cambridge, 1999. https://www.repository.cam.ac.uk/handle/1810/272097.

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4

Bateman, Ashley. "The Dynamics of Microbial Transfer and Persistence on Human Skin". Thesis, University of Oregon, 2017. http://hdl.handle.net/1794/22709.

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The skin microbiome is a critical component of human health, however, little is understood about the daily dynamics of skin microbiome community assembly and the skin’s potential to acquire microorganisms from the external environment. I performed a series of microbial transfers using three skin habitat types (dry, moist, sebaceous) on human subject volunteers. Microbial communities were transferred to recipient skin using a sterile swab 1) from other skin sites on the same individual, 2) from other skin sites on a different individual, 3) and from two environmental donor sources (plant leaf surfaces and farm soil). With these experiments I was able to test for the presence of initial transfer effects and for the persistence of those effects over the time period sampled (2-, 4-, 8-, and 24-hours post-transfer). The sebaceous skin community was associated with the strongest initial effect of transfer and persistence on the moist recipient skin site, and to a lesser extent the dry skin site. The soil donor community when transferred to dry skin resulted in the strongest initial transfer effect and was persistent over 8- and even 24-hours post-transfer. These experiments are the first in scope and scale to directly demonstrate that dispersal from other human or environmental microbial communities are plausible drivers of community dynamics in the skin microbiome.
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5

Escoda, Assens Lídia. "Applications of next-generation sequencing in conservation genomics: kinship analysis and dispersal patterns". Doctoral thesis, Universitat de Barcelona, 2018. http://hdl.handle.net/10803/586083.

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Knowledge of the genealogical relationships among individuals of a population and their dispersal patterns are essential to many studies of endangered species, especially those with small and fragmented populations. The main objective of this doctoral thesis is to use genomic data obtained with next-generation sequencing techniques to infer contemporary dispersal patterns of species from relatedness networks, to construct pedigrees from kinship categories, and to quantify the effect of anthropogenic and geographic barriers on the dispersal of individuals, using as a model the Pyrenean desman (Galemys pyrenaicus), a small semi-aquatic mammal endemic to the Iberian Peninsula. First, the contact zone between two lineages of the Pyrenean desman in the Iberian Range (La Rioja) was studied using SNPs obtained from ddRAD (double-digest restriction associated DNA) genomic libraries. According to the genomic tree, the principal component analysis, and the population structure analyses, the genetic variability in the area was structured by rivers instead of by mitochondrial lineages. Relatedness and inbreeding coefficients were then calculated with a maximum-likelihood estimator. Mean relatedness was found to be very high in the area. Individuals also showed high inbreeding levels. The reliability of these estimates was assessed with bioinformatics simulations based on artificial pedigrees that included as founders actual genotypes of the studied population. The relatedness networks showed a low level of contemporary inter-river dispersal compared to intra-river dispersal, indicating poor connectivity between rivers. Then, kinship relationships and pedigrees of Pyrenean desmans of two rivers of the northwestern part of the Iberian Peninsula (Zamora) were inferred. The ddRAD protocol was modified to allow processing each sample independently, which enabled the use of minimally invasive hair samples. Mean relatedness and inbreeding coefficients obtained from the SNPs were much lower than those from La Rioja. In addition, relatedness was higher for female dyads than for male dyads, suggesting a higher degree of female philopatry. Kinship categories were determined and their reliability was assessed using bioinformatics simulations based on artificial pedigrees. Using these kinship categories, pedigrees were reconstructed and their congruence was evaluated with the age of the individuals, the mitochondrial haplotypes, and the inbreeding coefficients. Pedigrees allowed the estimation of the average dispersal distance per generation, as well as preliminary data about the reproductive biology of the species. Finally, the assortativity coefficient obtained from the kinships networks was used to quantify the effect of specific barriers on the dispersal of individuals in the two rivers studied of Zamora, the Tera and the Tuela. The most important barrier found with this approach was the watershed divide between both rivers, followed by a dam located in one of them. These results were highly congruent with those obtained from the population structure analysis. The information obtained with the approaches presented in this thesis can be used to unravel fundamental aspects about the biology of endangered species, such as their dispersal patterns and their reproductive biology, as well as to quantify the effect of potential barriers on dispersal. These data may be fundamental to develop conservation plans aimed at improving the connectivity between populations.
El conocimiento de las relaciones genealógicas entre individuos de una población y sus patrones de dispersión son esenciales en muchos estudios sobre especies amenazadas, especialmente de aquellas con poblaciones pequeñas y fragmentadas. El objetivo principal de esta tesis doctoral es utilizar datos genómicos obtenidos con técnicas de secuenciación de última generación para inferir patrones de dispersión contemporánea de las especies a partir de redes de parentesco, construir pedigríes a partir de categorías de parentesco y cuantificar el efecto de barreras antropogénicas y geográficas en la dispersión de individuos, usando como modelo el desmán ibérico (Galemys pyrenaicus), un pequeño mamífero semi-acuático endémico de la Península Ibérica. En primer lugar, se estudió la zona de contacto entre dos linajes de desmán ibérico en el Sistema Ibérico (La Rioja) usando SNPs obtenidos mediante bibliotecas genómicas ddRAD (DNA asociado a sitios de restricción con doble digestión). De acuerdo con el árbol genómico, el análisis de componentes principales y el análisis de estructura poblacional, la variabilidad genética en el área estudiada resultó estar estructurada por ríos en lugar de por linajes mitocondriales. A continuación, los coeficientes de parentesco y de consanguinidad fueron calculados con un estimador de máxima verosimilitud. La media del coeficiente de parentesco encontrada en el área fue muy alta. Los individuos también mostraron altos niveles de consanguinidad. La fiabilidad de estas estimaciones se comprobó mediante simulaciones bioinformáticas basadas en pedigríes artificiales que incluían como fundadores genotipos reales de la población estudiada. Las redes de parentesco construidas mostraron un bajo nivel de dispersión contemporánea entre ríos en comparación con la dispersión dentro de ríos, lo que indicaba una mala conectividad entre los ríos del Sistema Ibérico. Después se infirieron las relaciones de parentesco y los pedigríes de desmanes ibéricos de dos ríos del noroeste de la Península Ibérica (Zamora). El protocolo de ddRAD se modificó y optimizó para poder procesar cada muestra de forma independiente, lo que permitió el uso de muestras de pelo mínimamente invasivas. Las medias de los coeficientes de parentesco y de consanguinidad obtenidos a partir de los SNPs fueron mucho más bajas que en La Rioja. Además, la media del coeficiente de parentesco fue mayor para las parejas de hembras que para las de machos, lo que sugiere un mayor grado de filopatría de las hembras. Se determinaron las categorías de parentesco existentes y se evaluó su fiabilidad con simulaciones bioinformáticas basadas en pedigríes artificiales. Usando estas categorías de parentesco, se reconstruyeron pedigríes y se evaluó su congruencia mediante la comprobación de la edad de los individuos, los haplotipos mitocondriales y los coeficientes de consanguinidad. La reconstrucción de pedigríes permitió estimar el promedio de la distancia de dispersión por generación, así como datos preliminares sobre la biología reproductiva de la especie. Por último, se usó el coeficiente de asortatividad obtenido a partir de las redes de parentesco para cuantificar el efecto de barreras específicas en la dispersión de los individuos en los dos ríos estudiados en Zamora, el Tera y el Tuela. La barrera más importante encontrada en el área fue la divisoria de aguas entre ambos ríos, seguida por una presa situada en uno de ellos. Estos resultados fueron altamente congruentes con los obtenidos con el análisis de estructura poblacional. La información obtenida con el enfoque metodológico presentado en esta tesis puede ser usada para desentrañar aspectos fundamentales sobre la biología de especies amenazadas, como pueden ser sus patrones de dispersión y su biología reproductiva, así como para cuantificar el efecto de barreras potenciales en la dispersión. Estos datos pueden ser fundamentales para desarrollar planes de conservación dirigidos a la mejora de la conectividad entre diferentes poblaciones.
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6

Mogollones, Barrera Sol C. "Seed dispersal, seedling emergence and bird community structure in a human-modified landscape mosaic in Sri Lanka". Thesis, University of Aberdeen, 2013. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=202126.

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7

Hulme-Beaman, Ardern. "Exploring the human-mediated dispersal of commensal small mammals using dental morphology : Rattus exulans and Rattus rattus". Thesis, University of Aberdeen, 2014. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=215116.

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A handful of rat species are among the most pervasive mammal species across the globe, primarily because of their close relationship with humans. The processes involved in this relationship, commensalism, are described in detail. Two rat species, Rattus rattus and Rattus exulans, are the focus of this thesis and their biology and taxonomy are described and discussed. Their modern distributions are the direct result of some of the earliest and most extensive human migration events in human history. The archaeology of the Pacific and Indian Oceans is described and migration vectors and spheres of interaction are identified. These possible patterns of human migration and exchange networks provide testable hypotheses that can be investigated using the subject rat species as proxies for long distance human movement. Modern and archaeological tooth samples of R. exulans and modern samples of R. rattus are analysed using geometric morphometrics. The results reveal important aspects of human migration and differences between these species' biology. R. exulans was likely to have been transported out of Island Southeast Asia at a very early date. Human colonisation of the Pacific occurred in a series of complex pulses and pauses that are clearly reflected in the R. exulans data. For the first time it is possible to demonstrate, within one dataset, the multiple origins and directions of colonisation across the Pacific. The R. rattus data provides a striking comparison, showing very different results that allude to a different level of modern gene-­‐ flow and therefore a difference in behaviour and biology. The results provide a framework for comparison with future archaeological material. The results presented and hypotheses raised have immediate application to existing archaeological material and areas of interest. Further commensal species should be examined following similar lines of questioning as applied here.
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8

Blome, Margaret Whiting. "Lacustrine Paleoecological Records and Modern Training Sets from Lake Malawi: Implications for African Paleoclimate and Connections to Human Prehistory". Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/265558.

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African climate changed considerably throughout the Pleistocene (2.588 million (Ma) to 12 thousand years ago (ka)). The timing, rate, and magnitude of past climate change across the continent impacted the evolutionary and migratory history of many mammalian species, including hominins. Investigating paleoclimatic variability through time at local and regional scales allows for an assessment of the extent to which climate change affected hominin evolution in Africa. This dissertation presents three approaches for increasing the understanding of past climate change in Africa. One method is to critically synthesize the existing literature of African climate (n=85) and hominid demography (n=64) over a restricted time frame (150 ka to 30 ka) and specific spatial scale (regional). Results from this study are two-fold: 1) climate change in Africa during this period was variable by region, responding to different climate-forcing mechanisms, and 2) changes in population and climate were asynchronous and likely created alternating opportunities for migration into adjacent regions, including hominin migrations out of Africa (~140-80 ka). The second approach is to evaluate modern ecological relationships between species and their environment to better quantify interpretations of paleoecological records. A modern distribution study of 33 ostracode species from 104 sites in the southwest arm of Lake Malawi suggest that depth-dependent variables likely define species niches. Relationships between ostracodes, fish and the green algae Botryococcus, were used to inform the paleoecological interpretations in the third study of this dissertation. Additional results suggest that macrocharcoal is likely delivered to the lake basin via river rather than wind-borne methods. The third approach involves primary analysis of climatic indicators from the sedimentary record to chronicle paleoecological and paleoenvironmental change at the basin scale through time. Results from a 380.7 meter-long sediment core recovered from Lake Malawi indicate a change of state likely caused by local tectonism, which affected ostracode assemblages, but had little effect on lake level history through time. Furthermore, the local hydroclimate of Lake Malawi alternately covaried with global glacial/interglacial cycles and local insolation maxima over the past 1.25 Ma. The magnitude and frequency of hydroclimatic variability in the watershed will be further assessed in future research.
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Kirika, Jasper Mbae [Verfasser]. "Frugivores, seed dispersal and tree regeneration along a human disturbance gradient in East African tropical rainforests / Jasper Mbae Kirika". Mainz : Universitätsbibliothek der Johannes Gutenberg-Universität Mainz, 2007. http://d-nb.info/1225402077/34.

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10

Auffret, Alistair G. "Seed mobility and connectivity in changing rural landscapes". Doctoral thesis, Stockholms universitet, Institutionen för naturgeografi och kvartärgeologi (INK), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-89105.

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The success or failure of many organisms to respond to the challenges of habitat destruction and a warming climate lies in the ability of plant species to disperse between isolated habitats or to migrate to new ranges. European semi-natural grasslands represent one of the world's most species-rich habitats at small scales, but agricultural intensification during the 20th century has meant that many plant species are left only on small fragments of former habitat. It is important that these plants can disperse, both for the maintenance of existing populations, and for the colonisation of target species to restored grasslands. This thesis investigates the ecological, geographical and historical influences on seed dispersal and connectivity in semi-natural grasslands, and the mobility of plants through time and space. Seed dispersal by human activity has played a large role in the build-up of plant communities in rural landscapes, but patterns have shifted. Livestock are the most traditional, and probably the most capable seed dispersal vector in the landscape, but other dispersal methods may also be effective. Motor vehicles disperse seeds with similar traits to those dispersed by livestock, while 39% of valuable grasslands in southern Sweden are connected by the road network. Humans are found to disperse around one-third of available grassland species, including several protected and red-listed species, indicating that humans may have been valuable seed dispersers in the past when rural populations were larger. Past activities can also affect seed mobility in time through the seed bank, as seeds of grassland plant species are shown to remain in the soil even after the grassland had been abandoned. Today however, low seed rain in intensively grazed semi-natural grasslands indicates that seed production may be a limiting factor in allowing seeds to be dispersed in space through the landscape.

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Accepted. Paper 4: In press. Paper 5: Manuscript.

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Kaartinen, S. (Salla). "Space use and habitat selection of the wolf (Canis lupus) in human-altered environment in Finland". Doctoral thesis, Oulun yliopisto, 2011. http://urn.fi/urn:isbn:9789514293825.

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Abstract The grey wolf is the most widely distributed of all land mammals and is a habitat generalist that inhabits all the vegetation types of the Northern Hemisphere. Wolves also breed well and have the potential to rapidly expand to new areas. In Finland, the wolf is a game species, and as a result of Finland’s membership of the European Union, the wolf population is subject to very limited hunting due to the obligation to protect the species. Mainly for this reason, the wolf population in Finland has increased significantly in recent years. In particular, the birth rate has developed favourably and the number of litters increased from just four in 1996 to 20 in 2005. It also seems at present that the wolf population in Finland is no longer following the fluctuations in wolf numbers in Russian Karelia. The general aim of this dissertation is to provide applicable knowledge for wolf management and conservation purposes, and especially to examine the effects of human-modified landscapes on wolf population expansion in Finland. Various aspects of habitat selection were investigated in four sub-studies to gain a thorough insight into the space use and habitat needs of wolves. Species data came from a long-term wolf population study that included location information from 85 radio- and GPS-GSM-collared wolves from 1998 onwards, as well as track location data based on about 30 000 annual observations recorded with geographical coordinates by a local network of experts on large carnivores. I found that adaptability makes it possible for the wolf to live in the multiple-use, semi-wild forests of Finland and that no restrictions are imposed by the landscape on wolf population growth and expansion. In general, the results of my dissertation provide evidence that wolves tend to avoid the presence of human influence when establishing a territory and also when selecting their den site. However, as wolf numbers increase, conflict situations will more frequently occur between wolves and humans, although the risk of depredation events, for example among sheep farms, varies between farms in Finland. That is, there are some environmental and farm level factors that are associated with wolf depredation. The breeding wolf population in Finland has gradually expanded and the first litters have recently been born in western Finland after an absence of more than 100 years. The geographical distance to the Scandinavian population is shorter from these new western territories than from the population’s core area in eastern Finland. This could potentially increase the likelihood of dispersal from Finland to Scandinavia
Tiivistelmä Susi on habitaattigeneralisti, jonka levinneisyys kattaa kaikki pohjoisen pallonpuoliskon kasvillisuustyypit. Sudet myös lisääntyvät hyvin ja voivat näin ollen levittäytyä nopeasti uusille alueille. Suomessa susi on riistalaji, jonka metsästys on rajoitettua Euroopan unionin jäsenyyden myötä. Lähinnä tästä syystä Suomen susikanta on kasvanut voimakkaasti 1990-luvun ja 2000-luvun alun aikana. Erityisesti syntyvyys on kasvanut: pentueiden määrä lisääntyi neljästä 20:een vuosien 1996 ja 2005 välillä. Näyttäisi siltä, ettei Suomen nykyinen susipopulaatio enää seuraa Venäjän Karjalassa tapahtuvia kannanvaihteluita. Väitöskirjan tavoitteena on ollut tuottaa susikannan hoidossa ja suojelussa käytettävissä olevaa tietoa ja erityisesti tutkia susikannan levittäytymistä ihmisen muokkaamassa ympäristössä Suomessa. Neljässä osatutkimuksessa on käsitelty suden habitaatinvalintaa eri näkökulmista, jotta saataisiin kokonaiskuva suden tilankäytöstä Suomessa. Tutkimusaineisto rakentui pitkäaikaisesta seuranta-aineistosta, jota on kerätty vuodesta 1989 lähtien. Vuosien 1989 ja 2010 välillä 85 sutta on pannoitettu radio- tai GPS-GSM –pannalla. Tutkimuksessa käytettiin hyväksi myös noin 30 000 vuosittain tehtyä jälkihavaintoa. Tutkimustulosten perusteella susi selviää hyvin Suomen monikäyttömetsissä, eivätkä maisematyypit itsestään rajoita susipopulaation kasvua ja levittäytymistä. Toisaalta tulokset osoittavat myös sen, että sudet välttelevät ihmistoimintoja valitessaan reviiri- tai pesäpaikkoja. Kuitenkin susien lukumäärän kasvaessa ristiriitatilanteet susien ja ihmisten välillä tulevat lisääntymään, vaikka susivahinkoriskin suuruus vaihteleekin Suomessa huomattavasti. Esimerkiksi lammastilojen susivahinkoriski riippuu sekä ympäristötekijöistä, että tilan sisäisistä tekijöistä. Kaiken kaikkiaan lisääntyvän susipopulaation esiintymisalue on Suomessa vähitellen kasvanut leviten itärajan tuntumasta kohti länttä. Tämän myötä maantieteellinen etäisyys Skandinavian susipopulaatioon on pienentynyt viimeisten vuosien aikana. Tämä voi edesauttaa susiyksilöiden siirtymistä Suomesta Skandinaviaan
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Henselowsky, Felix [Verfasser], Olaf [Gutachter] Bubenzer e Georg [Gutachter] Bareth. "Early Late Pleistocene environments in Northeast Africa and their relevance for Anatomically Modern Human dispersal / Felix Henselowsky ; Gutachter: Olaf Bubenzer, Georg Bareth". Köln : Universitäts- und Stadtbibliothek Köln, 2019. http://d-nb.info/1197797424/34.

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Chichkoyan, Kayayan Karina Vanesa. "Initial human dispersal and native fauna at the South American southern cone, Argentina. An example case from the revision of the fossil collections". Doctoral thesis, Universitat Rovira i Virgili, 2017. http://hdl.handle.net/10803/404087.

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Abstract (sommario):
La falta de registres directes com intervencions biològiques (marques de tall i marques de carnívors) no ha permès la discussió de com serien les relacions paleoecològiques de competència i depredació entre humans, megaherbívors i carnívors durant la primera dispersió humana a les Amèriques. Buscar aquest tipus d’informació en fonts no tradicionals dins de la investigació arqueològica, com les col•leccions vuitcentistes de fauna nativa, és una manera alternativa d’obtenir dades. Aquesta temàtica permet entendre com Homo sapiens intervingué en un ecosistema natiu establert i que mai havia estat alterat per la presencia homínida. El primer poblament humà a les Amèriques pot ser caracteritzat com a invasiu, ja que aquesta espècie no nativa va tenir una ràpida dispersió. Es va fer ús de la tafonomia per diferenciar intervencions biològiques, d’altre tipus de modificacions. A partir de les espècies registrades amb marques biològiques, els humans haurien depredat (i/o carronyejat) sobre especies que posseïen defenses desenvolupades per confrontar carnívors holàrtics (gigantisme en el cas de Megatherium americanum o cuirassa en Glyptodontidae) mentre que especies més petites dins la megafauna (Mylodontidae) haurien estat explotades per carnívors i humans. Així els carnívors haurien aprofitat alguns taxons d’aquesta megafauna en diferents moments del Pleistocè. Aquesta situació es va mantenir malgrat les fluctuacions ambientals. Al final d’aquest període, l’ingrés d’ Homo sapiens, va suposar afegir un nou carnívor en la cadena tròfica, que hauria depredat una major varietat d’espècies, moltes d’elles no explotades pels carnívors presents. Els grups humans haurien modificat els nitxos ecològics existents i colonitzat les vacants afectant les relacions de competència i depredació establerta. Aquest fet va provocar impactes directes i indirectes en la cadena tròfica nativa, que a llarg termini hauria afectat la sostenibilitat d’aquest ecosistema.
La escasez de registros directos como intervenciones biológicas (huellas de corte y marcas de carnívoros) no ha permitido la discusión de cómo serían las relaciones paleoecológicas de competencia y depredación entre humanos, megaherbívoros y carnívoros durante la primera dispersión humana en las Américas. Buscar este tipo de información en fuentes no tradicionales dentro de la investigación arqueológica, como las colecciones decimonónicas de fauna nativa, es una manera alternativa de obtener datos. Esta temática permite entender cómo Homo sapiens intervino en un ecosistema nativo establecido y que nunca había sido alterado por la presencia homínida. El primer poblamiento humano en las Américas puede ser caracterizado como de invasivo, ya que esta especie no nativa tuvo una rápida dispersión. Se hizo uso de la tafonomía para diferenciar intervenciones biológicas, de otro tipo de modificaciones. A partir de las especies registradas con marcas biológicas, los humanos habrían depredado (y/o carroñado) sobre especies que poseían defensas desarrolladas para confrontar carnívoros holárticos (gigantismo en el caso de Megatherium americanum o coraza en Glyptodontidae) mientras que especies más pequeñas dentro de la megafauna (Mylodontidae) habrían sido explotada por carnívoros y humanos. Así los carnívoros habrían aprovechado algunos taxones de esta megafauna en distintos momentos del Pleistoceno. Esta situación se mantuvo a pesar de las fluctuaciones ambientales. Al final de este período, el ingreso de Homo sapiens, supuso añadir un nuevo carnívoro en la cadena trófica, que habría depredado una mayor variedad de especies, muchas de ellas, no explotadas por los carnívoros presentes. Los grupos humanos habrían modificado los nichos ecológicos existentes y colonizado los vacantes, afectando las relaciones de competencia y depredación establecidas. Esto provocó impactos directos e indirectos en la cadena trófica nativa, lo que a largo plazo habría afectado la sustentabilidad de este ecosistema.
The scarcity of direct evidence as biological interventions (cut maks or carnivore marks) made difficult the discussion of how paleoecological relationships (e.g.. depredation an competition) should have been between humans, megaherbivores and carnivores during first humans’ dispersal in the Americas. To search this type of evidence in non-traditional archaeological sources, such as nineteenth collections of native fauna, is an alternative way to obtain information. This allows the understanding of how Homo sapiens has intervened in the established native ecosystem that has never been changed by hominid presence. First human dispersal in the Americas can be characterized as invasive, as this non-native species had a fast dispersion. Taphonomy was used to differentiate biological interventions from other types of modifications. Considering the identified species with biological marks, humans should have depredate (or scavenge) over species that possessed defences to confront holartic carnivores (gigantism in Megatherium americanum case or armor in Glyptodontidae case). Smaller species of the megafauna, such as Mylodontidae, should have been exploited by carnivores and humans. Therefore carnivores should have consumed some taxa of the megafauna in different moments of the Pleistocene period. This situation was sustained thought time despite environmental fluctuations. At the end of the Pleistocene, Homo sapiens entrance should have implied the addition of a new carnivore in the trophic chain. This new species had depredated over a major variety of fauna, even those ones not exploited by the native carnivores. Humans should have modified the existing ecological niches and colonized the empty ones affecting the established competition and depredation relationships. This provoked direct and indirect impacts in the native trophic chain. In long term, this situation should have affected the sustainability of this ecosystem.
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14

Pflüger, Femke [Verfasser]. "Advancing our understanding of animal dispersal and functional connectivity in human-altered landscapes: conceptual considerations and their empirical and simulation-based demonstration / Femke Pflüger". Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2020. http://d-nb.info/1217062793/34.

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15

Morandi, Marc Joseph. "Assessing the Influence of Different Inland Lake Management Strategies on Human-Mediated Invasive Species Spread". University of Toledo / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1365116997.

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16

Whittington‐Jones, Brendan Mark. "The dispersal of African wild dogs (Lycaon Pictus) from protected areas in the Northern KwaZulu‐Natal Province, South Africa". Thesis, Rhodes University, 2012. http://hdl.handle.net/10962/d1013414.

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Abstract (sommario):
The number of African wild dogs Lycaon pictus in Northern KwaZulu‐Natal, South Africa has increased substantially over the last six years. This is largely due to a managed metapopulation approach of introductions onto protected areas and private game reserves since 1998. Because of the increasing wild dog population, the likelihood of rural communities surrounding protected areas encountering dispersing wild dogs in northern KwaZulu‐Natal has also increased. Resident wild dog populations currently occur in Hluhluwe‐iMfolozi Park (HiP), Mkhuze Game Reserve (MGR) of Isimangaliso Wetland Park and Thanda Private Game Reserve (TPGR) all of which are bordered by a matrix of natural habitats and human settlements. Thus, land outside these protected areas could be utilized to expand wild dog distribution and provide connectivity between existing resident populations of wild dogs within KwaZulu‐Natal. To investigate the viability of such an approach, Maximum Entropy Modelling (Maxent) was used to characterize habitat niche selection of dispersing wild dogs, and to identify potential dispersal linkages between current wild dog metapopulation reserves. The model was calibrated using 132 location points collected from 2006 until 2009. From 2008 to 2009 I also conducted a survey of 247 community members in tribal authorities bordering HiP and MGR, to understand factors influencing attitudes towards wild dogs. A habitat suitability model with seven predictor variables had an AUC of 0.96 (SD = 0.02) and indicated four variables which best predicted probability of presence for dispersing wild dogs: elevation, road density, land cover and human density. The results suggest that elevation and land cover may be of greater influence for dispersing wild dogs than human density or activity. Elevation was the single most effective variable indicating a higher probability of presence for dispersing wild dogs in lower lying locations; peaking at approximately 200 – 300m a.s.l. Wild dogs also showed a preference for Woodland and Bushland habitats which in KwaZulu‐Natal tend to be found on lower lying topography. A preference for areas of lower human density and a highest probability of presence at road densities of approximately 0.7km/km2 or less would suggest that while wild dogs may show a tendency to avoid areas of high human activity, they can coexist in close proximity to humans. Respondent’s attitudes, knowledge of wild dogs and livestock husbandry were interpreted by the development of a set of indices. Attitudes were positively related to formal education levels and wild dog‐specific education, but were not influenced by demographic factors such as gender, age and employment status. Eighty three percent of respondents believed efforts to protect wild dogs should continue. Respondents with higher numbers of livestock tended to have more positive attitudes towards wild dogs despite generally incurring higher losses to carnivore depredation than those with less livestock. This appears to be because the financial burden of livestock losses to those with fewer livestock is perceived to be a loss of a greater proportion of total financial wealth. The study highlighted the substantial scope for improvement in livestock management. Theft (34 percent), drought (30 percent) and disease (14 percent) were ranked as the greatest problems facing livestock owners while predators were ranked as the greatest problem by only 4 percent of respondents. My findings suggest that wild dogs are generally viewed positively or with ambivalence. Concerns over the potentially increasing threat to livestock, as natural prey numbers outside protected areas decline and wild dogs disperse from natal packs, are likely to be manageable. However, wild dog population expansion within KwaZulu‐Natal will continue to rely on managed core populations on perimeter‐fenced metapopulation reserves with tolerant communities and landowners contributing to the connectivity of isolated reserves. Generation of tolerance can be instilled through continued advocacy and education, supported by conflict mitigation initiatives and rapid response to conflict reports. The implementation of incentive schemes for adjoining private landowners to co‐manage wild dog populations will need to be addressed in conjunction with managed metapopulation practices and law enforcement, to promote range expansion, and reduce potentially lethal edge effects and wild dog‐human conflict.
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17

Lagostina, Elisa [Verfasser], Georg [Gutachter] Zizka e Christian [Gutachter] Printzen. "Dispersal and genetic exchange of lichen populations between the Maritime Antarctic and southern South America (with a focus on human impact) / Elisa Lagostina ; Gutachter: Georg Zizka, Christian Printzen". Frankfurt am Main : Universitätsbibliothek Johann Christian Senckenberg, 2020. http://d-nb.info/122843249X/34.

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18

Gravuer, Kelly. "Determinants of the introduction, naturalisation, and spread of Trifolium species in New Zealand". Master's thesis, Lincoln University. Bio-Protection and Ecology Division, 2004. http://theses.lincoln.ac.nz/public/adt-NZLIU20071015.060329/.

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Two conceptual approaches which offer promise for improved understanding of biological invasions are conceptualizing the invasion process as a series of distinct stages and explicitly incorporating human actions into analyses. This study explores the utility of these approaches for understanding the invasion of Trifolium (true clover) species in New Zealand. From the published literature, I collected a range of Trifolium species attributes, including aspects of global transport and use by humans, opportunistic association with humans in New Zealand, native range attributes, habitat characteristics, and biological traits. I also searched historical records to estimate the extent to which each species had been planted in New Zealand, a search facilitated by the enormous importance of Trifolium in New Zealand’s pastoral agriculture system. Regression analysis and structural equation modelling were then used to relate these variables to success at each invasion stage. Fifty-four of the 228 species in the genus Trifolium were intentionally introduced to New Zealand. Species introduced for commercial agriculture were characterised by a large number of economic uses and presence in Britain, while species introduced for horticulture or experimental agriculture were characterised by a large native range area. Nine of these 54 intentionally introduced species subsequently naturalised in New Zealand. The species that successfully naturalised were those that had been planted extensively by humans and that were well-matched to the New Zealand climate. A further 16 species (from the pool of 174 species that were never intentionally introduced) arrived and naturalised in New Zealand without any recorded intentional aid of humans. Several attributes appeared to assist species in unintentional introduction-naturalisation, including a good match to the New Zealand climate, a large native range area, presence in human-influenced habitats, a widespread distribution in Britain, and self-pollination capability. The 25 total naturalised species varied greatly in their current distributions and in the rates at which they had spread to achieve those distributions. Species that had spread quickly and are currently more widespread had been frequent contaminants in the pasture seed supply and have a long flowering period in New Zealand. Other biological traits and native range attributes played supporting roles in the spread process. Attributes facilitating success clearly varied among invasion stages. Humans played a dominant role at all stages of this invasion, although biological traits had increasing importance as a species moved through the invasion sequence. My findings suggest that incorporation of human actions and the stage-based framework provide valuable insight into the invasion process. I discuss potential avenues by which these approaches might be integrated into predictive invasion models.
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19

Mormina, Maria Eugenia. "Mitochondrial DNA perspectives on human dispersals in Mainland Southeast Asia". Thesis, University of Leeds, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442476.

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20

Faltyskova, Zuzana. "Human dispersals to Tierra del Fuego revealed by ancient mitochondrial DNA". Thesis, University of Cambridge, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.709073.

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21

Lowman, Mark Andrew. "Studies on the biochemical pharmacology of human dispersed skin mast cells". Thesis, University of Southampton, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292929.

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22

Stagaman, Keaton. "Investigating the Role of Immunity and Other Selective Pressures on the Assembly of the Gut Microbiota in Zebrafish and Humans". Thesis, University of Oregon, 2016. http://hdl.handle.net/1794/20455.

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Over the past few decades, it has become increasingly apparent that host-associated microbial communities play an integral role in the development, physiology, and health of their host organisms. All hosts have evolved mechanisms to filter the microbial taxa that comprise their resident intestinal microbial community, or gut microbiota. Utilizing the zebrafish as a model host organism, we documented the development of the gut microbiota through time, and found a significant shift in the composition of the gut microbiota after the onset of adaptive immunity. This led us to hypothesize that adaptive immunity is an important determinant of gut microbiota composition. We tested this hypothesis using wild type and rag1-/- zebrafish, which lack a functional adaptive immune system. Additionally we tested the robustness of the effects of adaptive immunity to dispersal of microbes between immune-compromised and immune-competent genotypes. We found that adaptive immunity had less of an effect on the composition of the gut microbiota than we expected, although there were intriguing differences in the nature of selection imposed when adaptive immunity was present than when it was absent. Because “westernization”, or market-integration, has been associated with significant changes in the human microbiota and certain health risks, we used similar analyses to those we applied to the zebrafish system to determine whether market-integration alters the filtering effects of inflammation and intestinal helminth parasites on the intestinal microbial community. We found that market-integration increased inter-subject dissimilarity and reduced inter-subject dispersal. Even small changes in the inflammation marker, CRP, were associated with differences in the gut microbiota, but these effects were reduced in the presence of helminth infection, which has been hypothesized to affect the microbiota by reducing inflammation. In total, this dissertation provides evidence for the nature and importance of host filters of the gut microbiota across two vertebrate species, as well as providing a framework for future studies of the effects of such filters on the assembly of the gut microbiota. This dissertation includes previously published, and unpublished, co-authored material.
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23

Gippet, Jérôme. "Patrons de distribution, dispersion par l’Homme et variations intraspécifiques au sein des paysages urbanisés : réponses des fourmis à l’urbanisation". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1286/document.

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L'urbanisation est un processus complexe tant par les mécanismes historiques, sociaux, économiques et environnementaux qu'il implique que par les multiples modifications qu'il provoque au sein des écosystèmes. Ainsi, les paysages urbanisés sont soumis à des changements spatialement et temporellement abrupts des conditions environnementales comme la température au sol et dans l'air, la fragmentation des habitats et les concentrations de divers polluants. Pourtant, malgré leur apparente inhospitalité pour la biodiversité, les milieux urbanisés sont de véritables écosystèmes où de nombreuses espèces, natives et invasives, sont capables de survivre et même de prospérer. L‟ « écosystème urbain » est désormais considéré comme un élément important du fonctionnement des environnements densément peuplés, de la santé et du bien être humain ainsi que de la conservation de la biodiversité. De manière plus fondamentale, l'urbanisation, au même titre que le changement climatique et les processus d'invasions biologiques, est une « expérience grandeur nature » nous offrant l'opportunité de comprendre les règles d'assemblage des communautés biologiques, les processus de sélection d'habitat et de dispersion ou encore les processus évolutifs d'adaptation et de diversification. Ce travail s'inscrit dans ce cadre de pensée en se proposant d'étudier les conséquences écologiques et évolutives de l'urbanisation à différents niveaux d'organisations biologiques chez les Formicidae. Cette thèse comprend 4 chapitres s'organisant autour des thèmes et questions suivants : Chapitre 1 : Urbanisation et communautés biologiques : Comment l'urbanisation affecte-t-elle la distribution des espèces à l'échelle du paysage ? Chapitre 2 : Urbanisation et dispersion par l'être humain : Conceptualisation et modélisation du rôle des activités humaines et des réseaux de transports dans la dispersion d'espèces. Chapitre 3 : Urbanisation et interactions biotiques : L'urbanisation affecte-t-elle les patrons de co-invasions d'un couple invasif hôte-parasite introduits indépendamment ? Chapitre 4 : Urbanisation et variations intraspécifiques : Les populations urbaines et rurales présentent-elles des différences de traits biologiques ? Nos résultats démontrent qu'en tant que changement multifactoriel, l'urbanisation affecte de manière complexe la composition des communautés biologiques en modifiant de manière idiosyncrasique la distribution des espèces natives et invasives. En effet, chacune des 7 espèces de fourmis étudiées était affecté par une combinaison unique de facteur environnementaux associés à l'urbanisation (p.ex. fragmentation des milieux ouverts, température de surface) mais également au climat (Chapitre 1, Gippet et al. 2016 Urban Ecosystems). Parce qu'ils concentrent des activités humaines, les paysages urbanisés sont le théâtre de multiples invasions biologiques. En effet, l'être humain déplace de nombreuses espèces, leur permettant de franchir des barrières biogéographiques mais aussi de se propager au sein des paysages. Afin de provoquer la discussion autour du concept de la dispersion des espèces par l'Homme, nous proposons un nouveau point de vue général centré sur les activités humaines (Chapitre 2, Partie 1, Gippet et al. soumis) ainsi qu'un modèle de propagation secondaire d'espèce invasive par les activités humaines : MoRIS, dont la principale innovation est d'utiliser la structure du réseau de transport pour influencer la direction des événements de dispersion (Chapitre 2, Partie 2, Gippet et al. In prep). La suite est à retrouver sur la version téléchargeable du manuscrit
Urbanization is a complex process involving simultaneous changes in several environmental conditions, including ground and air temperature (urban heat island effect), habitat fragmentation and chemical pollution. These changes are often associated with biodiversity loss and changes in ecosystems functioning. However, more than a sink for biodiversity, urban areas constitute true ecosystems where many native and alien species survive and even grow stable populations. The “urban ecosystem” is now considered as an important element in the functioning of densely populated environments, in human health and well-being, as well as in biodiversity conservation. More fundamentally, urbanization constitutes “real life experiment” offering ecologists an opportunity to better understand ecological and evolutionary processes over fine spatial and temporal scale. This thesis investigates ecological and evolutionary consequences urbanization at different biological organization levels using ants (Formicidae) as biological models. First, at the biological community level, we showed that native and alien ant responses to urbanization were species-specific as each species was affected by its own set of environmental changes associated with urbanization (e.g., fragmentation, ground temperature) and climate. Second, we explored the little studied process of human-mediated dispersal by (i) proposing a novel theoretical framework focusing on human activities rather than directly on species and (ii) developing an innovative simulation model of dispersal by transport in terrestrial landscapes, MoRIS (Model of Routes of Invasive Spread). Third, we investigated how urbanization affected novel biotic interactions between an alien ant species (Lasius neglectus), an alien ectoparasite fungus (Laboulbenia formicarum) and native ant species. We showed that urbanization impacted the size of L. neglectus colonies, which were smaller in urban area, as well as L. formicarum prevalence on L. neglectus, which was higher in urban areas. Finally, we investigated intraspecific variations between urban and rural conspecifics of an urban tolerant species: Lasius niger. We found that urban young queens were smaller and lighter, less stressed by high temperature and performed multiple mating more often than rural young queens. In common garden, colony founding success were globally similar but urban incipient colonies produced significantly less pupae (and consequently workers). We also found that workers produced in common garden experiments were more variable in size (higher head width variance in both inter- and intra-colony) in urban colonies than in rural colonies. No evidence for genetic differentiation between urban and rural populations was found, suggesting that gene flow was not disrupted between urban and rural populations. All our results converge to a renewed vision of ecological and potential evolutionary dynamics occurring in urban environments. Further investigation will be necessary to assess how ecological processes influence evolutionary trajectories in urban ecosystems, using both ecological (e.g. ant densities and abundances along the urban gradient) and genomic approaches (e.g. using “genotyping by sequencing” methods to identify genes responsible for adaptation to urbanization)
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24

Doody, Brendan J. "Riccarton Bush and the natural and social realities of native trees in Christchurch, New Zealand". Lincoln University, 2008. http://hdl.handle.net/10182/865.

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Urbanization has destroyed and fragmented previously large areas of natural habitat. Small remnants that still exist in numerous cities will be unable to sustain many viable wild plant populations if they do not expand into the surrounding urban matrix. Residential gardens surrounding such remnants, and which form a significant component of urban green space in many cities, could play a role in redressing this problem. Riccarton Bush, a 7.8 hectare forest remnant, and its surrounding suburban residential area, in Christchurch, New Zealand, is a good example. Over 125 years the reported number of native vascular plants in the bush has declined by a third. My study was an attempt to understand: 1) the ecological, social and cultural factors influencing the dispersal and regeneration of 12 native bird-dispersed woody species from Riccarton Bush, into surrounding residential properties; and 2) the potential role residential properties could play in the future of the bush. To examine these diverse factors I adopted an interdisciplinary research approach combining methodologies, concepts and theories from ecology and the social sciences. In a broader context my work was an attempt to demonstrate how urban ecology can further develop and strengthen by adopting and integrating new methodologies, theories and concepts. The ecological component involved recording individuals of the study species found on 90 randomly selected properties within a 1.4 km radius of the bush. Soil samples were also collected from 31 of those properties and placed in a glasshouse and the study species that germinated were recorded. Results showed some species, particularly kahikatea (Dacrycarpus dacrydioides), the most abundant species in the bush, are being dispersed and establishing on properties predominantly within 250 m of the forest margin. These juveniles are not reaching maturity as most gardeners tend to remove all non-planted woody species. Qualitative interviews with 16 residents and a quantitative survey of the residents of 85 of the properties provided insights into the social context which these natural processes were operating. Using notions of place and performance I argue that gardens are continuously created and recreated by humans and non-humans. Residents attempt to create and maintain a garden that fulfils their individual and familial needs and desires (e.g., aesthetics, leisure and privacy), and public responsibilities such as ensuring they have a ‘neat’ and ‘tidy’ garden. This involves selecting plants for colour, shape and the care they require, and encouraging certain performances (e.g., flowering) while controlling other undesirable plants and performances (e.g. growth, spread and shading). While people make connections between native plants, belonging and identity; the ‘scientific’ demarcation between native and exotic species often becomes obscured as the garden is co-created by people and plants. Some plants become more significant than others but usually this is attributable to their performances rather than whether they are native or exotic. Residential gardens have the potential to play a major role in the conservation of species restricted to urban remnants. My research suggests that although the potential exists for woody species restricted to Riccarton Bush to naturally regenerate in nearby gardens, this will not happen without human intervention. Plants will need to be eco-sourced and propagated to avoid detrimental impacts on the genetic health of remnant populations, and then actively planted in gardens. The success of such planting initiatives will be increased by providing residents with information about the plants that are suitable for their performative needs and desires (e.g., the size, colour, and maintenance requirements of plants) and, most importantly, control over the location of plantings. In concluding, I argue that by adopting new concepts, theories and methodologies, the productivity, creativity and relevance of urban ecology can be significantly enhanced.
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25

Chequer, Farah Maria Drumond. "Utilização do Teste de Micronúcleo na avaliação da toxicidade dos azo corantes Disperse Red 1, Disperse Orange 1 e Disperse Red 13". Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/60/60134/tde-14092008-235513/.

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Abstract (sommario):
Atualmente, a utilização de azo corantes pelas indústrias de tingimento constitui um problema ambiental e de saúde, considerando o lançamento de quantidades elevadas para o meio ambiente e a falta de dados toxicológicos dos corantes disponíveis para as indústrias. Vários estudos têm demonstrado o potencial genotóxico de diversos corantes azóicos, porém para os corantes Disperse Red 1, Disperse Orange 1 e o Disperse Red 13, não foram encontrados dados na literatura relativos à sua capacidade de dano ao material genético. Considerando que esses corantes são empregados em processos de tingimento no Brasil, esse trabalho teve como objetivo a avaliação de sua atividade mutagênica, utilizando o teste de micronúcleo (MN) em linfócitos humanos e em células HepG2. Os resultados obtidos no teste com linfócitos, demonstram que na menor concentração testada (0,2 µg/mL), o número de micronúcleos presentes foi semelhante ao controle negativo, mas esse número aumenta à medida que eleva-se a concentração. No entanto, a partir da concentração de 1,0 µg/mL, este valor começa a decair. Isso provavelmente se deve à citotoxidade dos corantes, levando à morte celular ou redução da divisão celular e, conseqüentemente, não há a formação de micronúcleo. Embora o perfil de mutagenicidade dos três corantes seja semelhante, o corante Disperse Red 13 parece ter maior potencial de dano sobre os linfócitos em relação aos demais, seguido pelo Disperse Red 1 e Disperse Orange 1, respectivamente. Os resultados obtidos para o teste de MN em células HepG2 foram semelhantes aos obtidos no teste feito em linfócitos. O aumento do número de micronúcleos em relação ao aumento da concentração dos corantes, ocorreu até o limite de 2,0 µg/mL em células HepG2, excetuando-se o corante Disperse Red 13, para o qual o limite foi de 1,0 µg/mL. E a partir desses pontos, considerados como limites, ocorreu uma redução no número de MN. Para este sistema celular, os três corantes parecem ter potencial mutagênico bastante semelhante. Portanto, a análise dos resultados mostrou que os corantes Disperse Red 13, Disperse Red 1 e Disperse Orange 1 são mutagênicos para sistemas celulares diferentes. Foi também avaliado Índice de Proliferação do Bloqueio de Citocinese (IPBC), que permite a avaliação de toxicidade celular ou atraso no ciclo celular por meio da determinação da proliferação celular nas culturas. Porém, neste estudo não foram observadas diferenças estatísticas entre o controle negativo e as concentrações testadas. Nossos resultados confirmam que os azo corantes constituem uma importante classe de contaminantes ambientais e devem ser avaliados e utilizados de forma cautelosa.
Currently, the use of azo dyes for the textile industries can causes direct and/or indirect effects on human health and on the environment, considering the discharge of industrial effluents that contain toxic dyes and the lack of reports in the literature about the toxic effects of these compounds. Several studies have been demonstrated the genotoxic effect of diverse azo dyes, however for the dyes Disperse Red 1, Disperse Orange 1 and Disperse Red 13 no information about their capacity to cause DNA damage was found in the literature. Considering that these dyes are used for dying processes in Brazil, the main of this work was the evaluation of the mutagenic activity of Disperse Red 1, Disperse Orange 1 and Disperse Red 13, using the micronucleus assay (MN) in human lymphocytes and HepG2 cells. For the lymphocytes assay, we observed that the number of micronucleus induced by the lowest concentration of each dye (0,2 µg/mL) was similar to the negative control. For the other concentrations we observed a dose response micronucleus formation, until 1,0 µg/mL. Above this concentration, the number of micronucleus has decreased, probably because of the cytotoxic effects of the dyes, which leads to cellular death or reduction of cellular division and, consequently, does not have the micronucleus formation. Although the mutagenicity profile of the three dyes is similar, Disperse Red 13 seems to be the strongest for the lymphocytes, followed by Disperse Red 1 and Disperse Orange 1, respectively. For the HepG2 cells the results were similar to the lymphocytes. For the three dyes we noted a dose dependent increase in the frequency of micronuclei. However, for the HepG2 the threshold for this increase was 2,0 µg/mL, except for Disperse Red 13, which the limit was at 1 µg/ml, after this point a reduction in the MN number occurred. For this cellular system, the three dyes seem to have similar mutagenic potential. Therefore, our results suggest that the dyes Disperse Red 13, Disperse Red 1 and Disperse Orange 1 are potentially mutagenic for different cellular systems. Besides, cytokinesis-block proliferation index (CBPI) was calculated, in order to evaluate cellular toxicity or delay in the cellular cycle through of the determination of the cellular proliferation in the cultures. No statistical difference was detected between the tested concentrations and the negative control. Our results confirmed that azo dyes constitute an important class of environmental contamination and they should be evaluated and used carefully.
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26

Rees, Paul Hywell. "Studies on the biochemical pharmacology of mast cells dispersed from the human large intestine". Thesis, University of Southampton, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292926.

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27

Baudouin, Guillaume. "Mode de colonisation et dynamique de propagation d'un termite américain à Paris". Thesis, Tours, 2017. http://www.theses.fr/2017TOUR4016/document.

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Abstract (sommario):
L’objectif principal de cette thèse est d’identifier les facteurs urbains et les caractéristiques biologiques de Reticulitermes flavipes qui ont permis à cette espèce invasive de coloniser et de persister en milieu urbain. Plus précisément, les études développées ont visé à mieux comprendre l’origine des colonies introduites à Paris, de déterminer comment celles-ci étaient arrivées en ville et, comment, malgré les moyens de lutte mis en oeuvre au cours de ces dernières décennies elles ont persisté dans le paysage parisien. Une première étude nous a permis de voir que les colonies présentes à Paris sont capables de persister et de réinfester des zones qui ont été précédemment traitées. Ces réinfestations sont possibles grâce aux modes de reproduction (néoténie) et de dispersion (par bouturage) de cette espèce qui lui permettent de survivre localement et de recoloniser des zones où les colonies avaient été partiellement éradiquées et ce, même après 15 ans. Dans une seconde étude, nous avons pu montrer deux facteurs majeurs pouvant expliquer la distribution et la propagation de R. flavipes à Paris : la structure complexe des colonies observées et la combinaison spécifique des variables de l’environnement parisien. Enfin, dans la troisième étude, nous avons décrit la dynamique d’expansion de cette espèce à des échelles nationales et régionales. Cette étude révèle des patterns de distribution variés, reflétant les caractéristiques propres des populations invasives de cette espèce en France. Dans ce travail, nous avons discuté de l’implication des caractéristiques biologiques et paysagères sur le succès invasif de cette espèce. Au vue des données obtenues au cours de cette thèse, nous avons également précisé les scénarios concernant l’histoire de l’invasion de ce termite en France, puis nous avons présenté quelques outils et préconisations qui pourraient permettre, selon nous, d’améliorer la lutte contre cet insecte nuisible en ville
The main objective of this thesis is to identify the urban factors and biological characteristics of Reticulitermes flavipes which have allowed this invasive species to colonize and persist in urban habitat. More specifically, the developed studies aimed at better understanding the origin of introduced colonies in Paris as well as determining how they persisted in the Parisian landscape, despite implementing pest control during the last decades. A first study allowed us to observe that Parisian colonies were able to persist and reinfest areas which were previously treated. These reinfestations are possible thanks to the mode of reproduction (neoteny) and the way of dispersal (by budding) of this species, which allows it to locally survive and recolonize areas where colonies had been partially eradicated, even fifteen years later. In a second study, we were able to highlight two main factors which could explain the distribution and propagation of R. flavipes in Paris: the observed complex colony structure and the specific combination of the Parisian environmental variables. Finally, in a third study, we were able to identify its dynamic of expansion at national and regional scales which showed varied distribution patterns, reflecting the peculiar characteristics of these invasive species populations in France. In this piece of work, we analyzed the implications of the biological and landscape characteristics on the successful invasion of this species. In the view of the data obtained in this thesis, we also suggested some scenarios on the invasion history of this termite species in France and we provided tools and recommendations which, according to us, could allow the improvement of pest management of this insect in cities
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28

Lau, Laurie Chi-Kwong. "Studies on the release characteristics and pharmacological regulation of mast cells dispersed from human nasal polyp tissue". Thesis, University of Southampton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295754.

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29

Dellazari, Letícia. "Sistema endócrino e desreguladores hormonais dispersos no ambiente: avaliação de uma proposta educacional". Pontifícia Universidade Católica do Rio Grande do Sul, 2009. http://hdl.handle.net/10923/2941.

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This study departed from previous research on endocrine disruptors, substances present in industrial chemicals, even in minimal amounts, that affecting the hormonal balance of animals, including humans. This work, in the context of Science Education, presents the evaluation of possible contributions of a Learning Unit about Human Physiology and Hormone Disrupters dispersed into the environment. The research involved the training of teachers education and was developed through a case study, with a mainly qualitative and descriptive approach. The subjects were students of a graduate course in Biological Sciences. The instruments to obtain informations consisted of an initial question to check the previous conceptions of students; a daily record of the meetings; a final questionnaire, with selfevaluation concerning the changes in knowledge and practice. All information obtained was analyzed using the methodology of Textual Analysis Discourse, resulting in three major categories, previously established from questions of research: exploring the initial knowledge of the students, their learning and the contributions to training of science teachers.Accordingly to the statements, few students had previous knowledge on the subject. Most of the students considered the experience valid due to innovation, both in methodology as in terms of content, because the implications for personal and professional life. The conclusions attest the importance of studying actual and diversified issues related to the CTS approach and of experimenting new methodologies during the graduation, as well as the need for constant updating of teachers, both in its continuing education as in initial formation. There was emphasis on the importance of science teachers in developing a more critical and questioning awareness on current and relevant issues to the society as the ethical use of Science and Technology.
Este estudo partiu de pesquisas anteriores sobre disruptores endócrinos, substâncias presentes em produtos químicos industrializados que, mesmo em quantidades mínimas, são capazes de afetar o equilíbrio hormonal de diversos animais, inclusive os humanos. Considerando como relevante incluir este tema na educação, o presente trabalho apresenta a avaliação de possíveis contribuições de uma Unidade de Aprendizagem, Fisiologia humana e desreguladores hormonais dispersos no ambiente, à formação inicial de professores de Ciências. A pesquisa foi desenvolvida por meio de um estudo de caso, com abordagem essencialmente qualitativa e descritiva, tendo como sujeitos os alunos de uma turma de um curso de graduação em Ciências Biológicas (Licenciatura). Os instrumentos para obter informações constaram de um questionário inicial para verificar as concepções prévias dos alunos; um diário de campo com registro dos encontros; um questionário final, com depoimentos auto-avaliativos quanto a transformações em conhecimentos e práticas. Todas as informações obtidas foram analisadas segundo a metodologia de Análise Textual Discursiva, resultando em três grandes categorias, estabelecidas previamente a partir das questões de pesquisa: explorando os conhecimentos iniciais; explorando o aprendizado dos licenciandos; explorando as contribuições para formação inicial de professores de Ciências.Foi constatado que, conforme os depoimentos, poucos alunos tinham conhecimentos prévios sobre o tema. A maioria considerou válido vivenciar a proposta devido à inovação, tanto pela metodologia como em termos de conteúdo, devido a implicações na vida pessoal e profissional. As conclusões atestam a importância de estudar temas atuais e diversificados relacionados ao enfoque Ciência Tecnologia e Sociedade (CTS) e experimentar novas metodologias durante a graduação, bem como a necessidade de atualização constante dos professores, tanto em sua educação continuada como na formação inicial. Houve destaque à importância dos professores de Ciências no desenvolvimento de uma consciência mais crítica e questionadora sobre assuntos atuais e relevantes para a sociedade, como o uso ético da Ciência e da Tecnologia.
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30

Valero, Thomas Ernesto. "A sustainable cartography of emerging and dispersed human landscapes : case study : the sustainable cartography of Ciudad Obregon, Mexico". Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/31009.

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The thesis is focused on the construction of cartographic systems not only as a tool for environmental representation, but also for shaping practices, values, technologies, and cultural narratives around sustainable development of human landscapes in non- Western contexts. Cartographic theory is employed to question existing mapping techniques, especially in relation to documenting sustainable development. The thesis investigates the merging of technology, science and art in the process of making maps and explores the possibility to represent several spheres of reality in cartographic elements. Representation concepts and methodologies were tested around the Mexican settlement of Ciudad Obregon, within the bioregion of the Gulf of California. Parts of the agendas for sustainable development revised stimulate the collection of dreams, images, and fantasies about non-Western human agglomerations and their ecosystems, critically informing sustainable narratives framed in other contexts. The works reviewed reveal an absence of complex cartographic and visual systems, portraying instead emerging landscapes in growing economies as exotic, mysterious, folkloric, chaotic, less developed, and in need of corrective study and supervision from a Western viewpoint. Interpretive, visual, and technological instrumentations were utilized with the aim of constructing a cartographic system that exposes dynamics of sustainable development in emerging settlements. The methodological scheme considers a series of associations between quantitative and qualitative approaches, employing eighteen dialectical negotiations in the representation of six ecologies. The outcome was a hybrid system of representation concerning bi-dimensional maps, photography, and chronicles from local newspapers. Two fieldtrips to Mexico were completed in 2012 and 2013, visiting and studying eighteen human agglomerations in total. The outcomes (measured and gathered data, perceptions, bibliography, photographs, and cartographic evidences) of both fieldtrips were linked to the hypothesis previously outlined in the literature review. The methodological structure was influenced by the cartographic representation interpretation of the biosphere of Ciudad Obregon and its natural ecosystems. On the other hand, the cartographic representation-interpretation of different networks resulted in the study of polymorphous infrastructures that facilitate the flow of goods, capital and people throughout the same territory. The correlation of the research interrogates the paradigmatic challenges of the ‘network society’ in developing contexts. It questions the notion that human settlements develop sophisticated infrastructure networks, selectively connecting together the most favoured users and places, linking valuable segments and discarding irrelevant habitats, locales and people. As the cartographic and visual evidences gathered by this research suggest, these commodity landscapes allow terrestrial and aerial flow of physical and knowledge resources (food, water, gasoline, telecommunications, transport, information, services, waste) in granulated and disseminated environments of buildings and networks, materializing a palimpsest of infrastructures. The research finds that the assessment of social, cultural, and environmental sustainability in emerging and dispersed landscapes requires an adjacent design of cartographic and visual frameworks that represent the complexity found in developing locations.
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31

Serra, Marcelo Galli. "Fenômenos de dispersão urbana no território paulista: o caso de Itupeva, 1990-2010". Universidade Presbiteriana Mackenzie, 2015. http://tede.mackenzie.br/jspui/handle/tede/3344.

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We can observe around the globe the emergence of a new type of urban occupation with a dispersive or diffused character, resulting from a number of factors, including the technological revolution, favorable turn-of-the-century global economic conditions, neoliberal urban policies, and new ways of life evolving in a redefined society. However, this occupation brings low densities, and burdens public agents with the expensive costs of extending infrastructure in vaster and distant spaces. This kind of occupation tends to multiply disorganized, disconnected, and often enclosed urban enclaves such as closed subdivisions, created according to the logic of real estate developers, limiting social exchange between social groups. This phenomenon, which presents peculiar traits in each locality or region – as seen in the referential cases of the American Sunbelt and Houston, Texas; and the megadevelopment of Nordelta to the North of Buenos Aires, Argentina – marks the formation of the São Paulo Macrometropolis, an urban complex in the State of São Paulo, Brazil, formed by the articulation of the Metropolitan Regions of São Paulo, Campinas, Baixada Santista, Vale do Paraíba / Litoral Norte, Sorocaba and the Urban Agglomerations of Jundiaí and Piracicaba; and, at the heart of this territory, occurs intensively in the city of Itupeva, which in this work is the object of study. Although a number of uses are present, the main protagonists in this case are residential subdivisions that function as gated communities, which multiplied intensively between the years 1990 and 2010. There is another example in the region that illustrates this phenomenon, the enterprise "Vida Completa Serra Azul", a private complex which brings together a range of urban activities; such as residential areas, hotel, theme parks, services and entertainment with controlled access. This urban morphology is supported by commercial enclaves, designed, implemented and managed by the private sector, and depends on your purchasing power to access its various elements.
Observa-se ao redor do globo a emergência, desde o final do século XX, de um novo tipo de ocupação urbana, de caráter disperso ou difuso, consequência de um conjunto de fatores que incluem a revolução tecnológica, as favoráveis condições econômicas globais vigentes em torno da última virada do século, políticas urbanas neoliberais e a readequação dos modos de vida numa sociedade em reformulação. Contudo, destaca-se a baixa densidade dessas ocupações, os onerosos custos para o poder público em termos da provisão de infraestrutura em extensões e distâncias muito ampliadas, e a natureza sócio-espacial dessa ocupação, que tende a se multiplicar de forma desorganizada e desconectada, formando muitas vezes enclaves, atendendo somente a pautas imobiliárias, sem relação com a cidade, desfavorecendo os palcos de troca social entre diferentes grupos sociais. Esse fenômeno, que apresenta diferentes particularidades em cada região ou local – como verificamos nos casos referenciais do Sunbelt e de Houston, Texas, nos Estados Unidos, e do macroempreendimento Nordelta, ao Norte de Buenos Aires, Argentina – marca a formação da Macrometrópole Paulista, complexo urbano formado pela articulação das regiões metropolitanas de São Paulo, Campinas, Baixada Santista, Vale do Paraíba / Litoral Norte, Sorocaba e pelas Aglomerações Urbanas de Jundiaí e Piracicaba; e, no âmago desse território macrometropolitano, ocorre de forma intensa no município de Itupeva/SP, Brasil, que nesta dissertação é o objeto de estudo. Embora haja variedades nos usos, nota-se a criação de loteamentos residenciais, funcionando como condomínios horizontais fechados, como principal protagonista desse processo nesse município, adquirindo maior intensidade de ocupação entre os anos de 1990 a 2010. Além do uso residencial, há na região um exemplo bem ilustrativo desse fenômeno, trata-se do empreendimento “Vida Completa Serra Azul”, complexo privado que reúne uma gama de atividades urbanas; como moradia, serviços e entretenimento, com acesso controlado – uma morfologia urbana sustentada por enclaves comerciais, onde depende-se de poder aquisitivo para acessar os variados elementos urbanos privados.
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32

Tendeiro, Diogo Filipe Lucas. "Implementação de um sistema para simulação por Monte Carlo da passagem de fotões através do olho humano mediante a utilização da plataforma GEANT4 - I". Master's thesis, Faculdade de Ciências e Tecnologia, 2012. http://hdl.handle.net/10362/7704.

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Dissertação para obtenção do Grau de Mestre em Engenharia Biomédica
A Degeneração Macular Relacionada com a Idade (DMRI) é uma doença ocular crónica e degenerativa que provoca milhões de casos de cegueira no mundo ocidental. Na maioria das situações, desenvolve-se com o aparecimento de drusas sob as camadas profundas da retina. A acumulação constante destas estruturas, resultantes da acumulação de material extra celular, promove a deterioração da camada de fotorreceptores da retina, originando-se pontos cegos na área da visão central dos indivíduos. O presente trabalho surgiu com o objectivo de simular e avaliar os resultados de uma hipótese de diagnóstico para esta doença, utilizando a plataforma de simulação Geant4, que aplica métodos de Monte Carlo. Adoptando alguns fundamentos de trabalhos anteriores, construíram-se programas, em linguagem C++, que simularam a interacção de feixes de fotões com as estruturas anatómicas de um globo ocular virtual. Neste âmbito, foram implementadas drusas de diferentes formatos, dimensões e posições na retina, com o objectivo de estudar a sua influência no padrão de dispersão do feixe de fotões reflectido. O registo dos padrões de dispersão foi obtido mediante a implementação de detectores no interior e no exterior do globo ocular. Os resultados deste trabalho mostraram que a presença de drusas na retina influencia o padrão de dispersão do feixe de fotões reflectido. Dependendo da sua forma, tamanho ou posição, as alterações são mais ou menos significativas, em comparação com os resultados da simulação sem drusas.
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33

Dellazari, Let?cia. "Sistema end?crino e desreguladores hormonais dispersos no ambiente : avalia??o de uma proposta educacional". Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2009. http://tede2.pucrs.br/tede2/handle/tede/3364.

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Este estudo partiu de pesquisas anteriores sobre disruptores end?crinos, subst?ncias presentes em produtos qu?micos industrializados que, mesmo em quantidades m?nimas, s?o capazes de afetar o equil?brio hormonal de diversos animais, inclusive os humanos. Considerando como relevante incluir este tema na educa??o, o presente trabalho apresenta a avalia??o de poss?veis contribui??es de uma Unidade de Aprendizagem, Fisiologia humana e desreguladores hormonais dispersos no ambiente, ? forma??o inicial de professores de Ci?ncias. A pesquisa foi desenvolvida por meio de um estudo de caso, com abordagem essencialmente qualitativa e descritiva, tendo como sujeitos os alunos de uma turma de um curso de gradua??o em Ci?ncias Biol?gicas (Licenciatura). Os instrumentos para obter informa??es constaram de um question?rio inicial para verificar as concep??es pr?vias dos alunos; um di?rio de campo com registro dos encontros; um question?rio final, com depoimentos auto-avaliativos quanto a transforma??es em conhecimentos e pr?ticas. Todas as informa??es obtidas foram analisadas segundo a metodologia de An?lise Textual Discursiva, resultando em tr?s grandes categorias, estabelecidas previamente a partir das quest?es de pesquisa: explorando os conhecimentos iniciais; explorando o aprendizado dos licenciandos; explorando as contribui??es para forma??o inicial de professores de Ci?ncias. Foi constatado que, conforme os depoimentos, poucos alunos tinham conhecimentos pr?vios sobre o tema. A maioria considerou v?lido vivenciar a proposta devido ? inova??o, tanto pela metodologia como em termos de conte?do, devido a implica??es na vida pessoal e profissional. As conclus?es atestam a import?ncia de estudar temas atuais e diversificados relacionados ao enfoque Ci?ncia Tecnologia e Sociedade (CTS) e experimentar novas metodologias durante a gradua??o, bem como a necessidade de atualiza??o constante dos professores, tanto em sua educa??o continuada como na forma??o inicial. Houve destaque ? import?ncia dos professores de Ci?ncias no desenvolvimento de uma consci?ncia mais cr?tica e questionadora sobre assuntos atuais e relevantes para a sociedade, como o uso ?tico da Ci?ncia e da Tecnologia.
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34

Will, Manuel [Verfasser], e Nicholas J. [Akademischer Betreuer] Conard. "Lithic technology and behavioral variability during the Middle Stone Age of southern Africa : Implications for the evolution and dispersal of early modern humans / Manuel Will ; Betreuer: Nicholas J. Conard". Tübingen : Universitätsbibliothek Tübingen, 2016. http://d-nb.info/1164169890/34.

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35

Watermeyer, Jessica Patricia. "Anthropogenic threats to resident and dispersing African wild dogs west and south of the Kruger National Park, South Africa". Thesis, Rhodes University, 2012. http://hdl.handle.net/10962/d1005318.

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African wild dog Lycaon pictus populations are declining and the species is listed as Endangered by the IUCN. The Kruger National Park (KNP) is home to the only viable population of wild dogs in South Africa, but census results reveal consistently low numbers since the late 1990s. Wild dogs display wide-ranging behaviour and it is possible that the species might frequently use unprotected lands adjacent to the KNP. However, very little is known about wild dog movements beyond the boundaries of the KNP, and whether or not adjacent land owners are tolerant of the species. Significantly, threats along the boundaries may have negative consequences for the KNP population. This research investigated the dispersal habits of wild dogs beyond the western and southern boundaries of the KNP, and gathered information on human tolerance, and anthropogenic threats in an area of mixed land use. The land west of the KNP presented the best prospect for wild dog range expansion. The wild dog packs operating outside the KNP had smaller home ranges and less home range overlap than the packs operating within the KNP. In addition, my data suggested that the development of conservancies and the formation of ecotourism-based land use practices would be beneficial for wild dog conservation. Failed wild dog dispersals due to snaring and human persecution could threaten the genetic stability and persistence of the KNP population. Therefore, raising awareness and an understanding of the plight of wild dogs is important for improving land owner perception and tolerance outside of protected areas. The rapidly increasing human population continues to infringe on protected lands and fragment landscapes, thus cooperation from individual land owners is vital for the conservation of free-ranging large carnivores.
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ALVES, Cyntia Santos Daltro. "Formas espaciais recentes da urbanização na Amazônia: a dinâmica socioespacial do município de Castanhal em face do processo de dispersão metropolitana de Belém". Universidade Federal do Pará, 2012. http://repositorio.ufpa.br/jspui/handle/2011/8188.

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A dinâmica metropolitana que caracteriza o atual contexto amazônico acarreta a conformação de novos arranjos espaciais urbanos, que necessitam ser considerados a partir de uma leitura dialética da realidade. No caso belenense, percebe-se que essa metrópole apresenta um caráter disperso, ao mesmo tempo em que se desconcentra, amplia-se ao criar novos vetores de expansão para além de sua área oficialmente considerada metropolitana. Nesse sentido, o presente trabalho tem por objetivo analisar a dinâmica socioespacial do Município de Castanhal em face do processo de dispersão metropolitana de Belém, haja vista a notória articulação existente entre ambos. Com o intuito de alcançar esse objetivo três variáveis foram consideradas para efeito de análise: a produção de espaços de moradia, a produção industrial e a acesso a serviços básicos. Para tanto, utilizou-se como instrumental teórico-metodológico o método de interpretação baseado no materialismo histórico-dialético, onde as relações de produção são analisadas como produto sociohistórico. Sendo assim, o processo de metropolização e de dispersão urbana devem ser compreendidos a partir do movimento dialético das práticas espaciais da sociedade. Com relação ao instrumental técnico-empírico, ressalta-se que a natureza da presente pesquisa está pautada em uma perspectiva qualitativa e quantitativa. Na perspectiva quantitativa algumas técnicas foram empregadas a saber: a quantificação da expansão urbana de Castanhal a partir de uma análise das imagens de satélite dos anos de 1984, 1994 e 2008, utilizando o software de geoprocessamento ARCGIS 9.3, bem como a construção de gráficos, tabelas e quadros a partir da sistematização de dados obtidos junto a órgãos oficiais, a exemplo do Instituto Brasileiro de Geografia e Estatística, buscando identificar estaticamente a intensidade das relações entre a Região Metropolitana de Belém (RMB) e Castanhal. Quanto à natureza qualitativa, utilizou-se técnicas como levantamento e análise bibliográfica, levantamento e análise documental e realização de entrevistas semiestruturadas com representantes das principais indústrias e distribuidoras de Castanhal, com intuito de analisar a produção industrial desse Município e sua relação com o processo de dispersão metropolitana de Belém. A partir dos dados levantados e analisados constatou-se que as práticas espaciais urbanas existentes no Município de Castanhal, voltadas aos espaços de assentamentos residenciais e industriais e serviços, promovem uma relação de interdependência com a RMB. Infere-se que tal relação seja fruto de uma nova configuração metropolitana, com base em uma dinâmica de fluxos que aponta para a existência de uma unidade urbana mais ampliada, fragmentada, dispersa e descontínua. Ratifica-se, portanto, a necessidade de se estudar o fenômeno metropolitano para além de sua forma institucionalizada, mas confirma a importância de se compreender o processo de urbanização, que imprime a determinadosespaços características consideradas metropolitanas.
The metropolitan dynamics that characterize the current amazon context, lead to an urban spatial reshape that need to be considered, based on a dialectical reading of this reality. In Belém, it is noted that the metropolis shows a dispersed mold. As it decentralizes, it expands, creating new expansion arrays beyond the considered legal metropolis’ borders. In this sense, this paper’s objective is to analyse the city of Castanhal’s socio-spatial dynamics against the sprawl process in Belém, considering the notorious link between them. In order to achieve this goal, three variables were considered: the providing of residential areas, industrial production and access to basic services. Therefore, the interpretation method based on the historical and dialectical materialism was used as theoretical-methodological tool, where the relations of production are analyzed as a social-historical consequence. That said, the metropolization process and urban sprawl must be realized from the dialectical movement of society’s spatial using. About the technical and empirical instruments, it must be said that this research’s nature is approached in a qualitative and quantitative perspective. In the quantitative perspective, some techniques were applied: the urban expansion quantification of Castanhal made from an analysis of satellites images from 1984, 1994 e 2008, using a software called ARCGIS 9.3, as well as the making of graphics and tabs using gathered data from official bodies, such as the Brazilian Institute of Geography and Statistics (IBGE), in order to statistically identify the relations force between Castanhal and Metropolitan Region of Belém (RMB). For the qualitative perspective, techniques such as survey and bibliographic analysis were used, as well as documental analysis and survey, and the making of interviews with representatives of the main Castanhal’s industries and distributors, in order to examine this city’s industrial production and its link to the metropolitan sprawl in Belém. Based on gathered and analyzed data, it was found that the urban spatial use in Castanhal dedicated to residences, industries and the third sector, create an interdependency link with RMB. One could infer that such relation is created by a new metropolitan configuration, based on flux dynamics that leads to the existence of an more amplified, disperse and discontinuous urban unity, confirming the need to study such metropolitan phenomenon beyond its institutionalized borders, and the importance of understanding the urbanization process that leads to metropolitan considered features on certain areas.
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37

Lasley, Carrie E. "Catastrophes and the Role of Social Networks in Recovery: A Case Study of St. Bernard Parish, LA, Residents After Hurricane Katrina". ScholarWorks@UNO, 2012. http://scholarworks.uno.edu/td/1504.

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The purpose of this dissertation is to examine the experiences of St. Bernard Parish, La., residents as they coped with the impact of the catastrophe of Hurricane Katrina on August 29, 2005. An estimated 50,000 St. Bernard Parish residents relocated to a new home one year after Katina in 2006, and many of those residents moved again. This study examines the effects of the decisions of St. Bernard residents to relocate or to return on their social connections. The utility, adaptability and durability of social networks of these residents will be explored to enrich our knowledge about the social effects of recovery and the role that distance plays in the way residents connect to each other six years after Hurricane Katrina. It also examines the applicability of disaster theory as it relates to this case and develops a methodology for examining the impact of geographic dispersal on social networks.
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FERREIRA, Sandro Brito. "A expansão dos assentamentos residenciais na Ilha do Mosqueiro: uma particularidade de dispersão urbana no espaço metropolitano de Belém (PA)". Universidade Federal do Pará, 2012. http://repositorio.ufpa.br/jspui/handle/2011/8210.

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O presente estudo tem como objetivo principal analisar a forma dispersa de Belém, tendo como referência empírica o Distrito Administrativo de Mosqueiro, espaço de lazer, tradicionalmente frequentado pela população da capital paraense. Nesse distrito, os assentamentos urbanos que se destacam em sua paisagem são os residenciais, especialmente os de uso ocasional, as chamadas segundas residências. Estas cresceram numericamente, em virtude do processo de metropolização de Belém, a partir de 1970. Atualmente, entretanto, a dispersão metropolitana de Belém, em uma escala geográfica mais ampla, tem sido decisiva para a incorporação de Mosqueiro como espaço de ação dos grupos sociais excluídos que lutam pela moradia, assim como para que as segundas residências sejam convertidas em moradias de uso permanente. Desse modo, a produção do espaço mosqueirense ocorre, fundamentalmente, em razão da reprodução das relações sociais de produção, sobretudo no que diz respeito à reposição da força de trabalho, por intermédio da conquista de uma moradia.
This study‟s main objective is to analyze Belém‟s sprawled shape, taking the Administrative District of Mosqueiro as empirical reference, which is a place for leisure, traditionally attended by the population of the Pará state capital. In this district, the urban settlements that distinguish themselves in the landscape are the residential ones, especially those occasionally used, the so called second residences. Their number increased due to the metropolization process in Belém since 1970. However, nowadays Belém‟s metropolitan sprawl, on a broader geographic scale, has been decisive in incorporating Mosqueiro as area of action of socially excluded groups that strive for housing as well as for the transformation of those second residences into primary ones. Thereby, the production of space in Mosqueiro occurs basically due to the reproduction of its social relations of production, mostly with regard to the replacement of workforce by the acquisition of housing.
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39

Medina, Nava Yedid, e García Javier Jaimes. "Detección del Virus del Papiloma Humano mediante HYBRID CAPTURE 2 en poblacion Femenina de 30 a 65 años del Centro de Salud Rural Disperso "La Laguna", San Pablo Autopan, 2012 - 2013". Tesis de Licenciatura, Medicina-Quimica, 2013. http://hdl.handle.net/20.500.11799/14405.

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Una infección persistente por tipos virales de alto riesgo del Virus del Papiloma Humano (VPH) desde el punto de vista biológico y epidemiológico es importante para el desarrollo de Cáncer Cervicouterino, siendo coparticipe de la evolución a neoplasias en el 70% de los casos. Objetivos: Determinar los resultados de detección del Virus del Papiloma Humano mediante Hybrid Capture 2 en población femenina de 30 a 65 años del Centro de Salud Rural Disperso La Laguna, San Pablo Autopan, durante el periodo de un año. Material y métodos: Se revisan los expedientes de pacientes que acudieron para detección de VPH mediante Hybrid Capture 2 (HC2) siendo un total de 188 pacientes, de las cuales se excluyeron 19 pacientes por estar fuera de rango de edad y 31 por no contar con resultado de la muestra de detección; de tal manera que el estudio quedó representado por 138 pacientes. Resultados: El intervalo por grupo de edad en el que predomina la detección es de 35 a 39 años con 40 casos (28.9 %). Referente al resultado de Hybrid Capture 2; 131 casos fueron negativos (94.93%) y 7 positivos (5.07%); 2 casos fueron del grupo de 30 a 34 años, 4 casos del grupo de 35 a 39 años y un caso de 40 a 44 años. Conclusiones: En el estudio los resultados de detección del VPH mediante captura de híbridos arrojaron una prevalencia del 5.07%. El cribado mediante HC2 para detección de serotipos con alto poder oncogénico resulta importante para intervenir en la transformación de éste, la infección persistente y su evolución a displasia.
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40

Förster, Matthias. "Évaluation de la pénétration cutanée des ingrédients de systèmes dispersés : utilisation combinée des cellules de diffusion et de la microscopie confocale Raman". Phd thesis, Université Claude Bernard - Lyon I, 2010. http://tel.archives-ouvertes.fr/tel-00865818.

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L'objet de cette thèse est l'étude de la pénétration des actifs cosmétiques dans la peau. Les axes d'investigation principaux ont concerné l'influence des propriétés physicochimiques des actifs et des ingrédients de la formule sur les mécanismes de pénétration. Les actifs cosmétiques choisis sont le rétinol, actif lipophile, et la caféine, actif hydrophile. Les formulations investiguées sont des émulsions de type huile dans eau, comparées aux solutions de tensioactifs correspondantes. Trois huiles cosmétiques ont été utilisées: Butylène glycol de cocoate, Octyldodecyl myristate et la Paraffine liquide, stabilisées en émulsion avec des tensioactifs ester de polyéthylène glycol (PEG20 et PEG6) possédant des longueurs de chaîne carbonées variables (C8, C12, C18 et C18:1). La pénétration percutanée a été mesurée quantitativement en utilisant la méthode des cellules de diffusion de Franz en fonctionnement statique et dynamique et qualitativement par la microscopie confocale Raman. Avec cette combinaison de techniques analytiques, il est possible, de mesurer la pénétration et d'évaluer l'impact de chaque composant de la formulation sur la pénétration cutanée d'un actif. Une corrélation a pu être établie entre l'effet fluidifiant d'une huile et l'augmentation de la pénétration du rétinol. Par ailleurs les tensioactifs, même s'ils ont montré un effet moindre en terme de fluidification conduisent également à une augmentation de la pénétration en raison d'une variation du coefficient de partage de l'actif entre la formule et la peau. Concernant la caféine, l'influence de la structure des tensioactifs et en particulier de la longueur de chaîne carbonée a été mise en évidence
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41

Ciesielski, Elsa. "La pratique celtique des "têtes coupées" en France méditerranéenne : l’exemple du site du Cailar (Gard) au IIIe s. av. n. è. Approche archéothanatologique et traitements informatiques des données". Thesis, Montpellier 3, 2017. http://www.theses.fr/2017MON30047.

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En Gaule méridionale la pratique des têtes coupées, décrite par la littérature antique, est attestée par les vestiges lapidaires et les restes humains mis au jour depuis plus d’un siècle. Des données inédites sur cette coutume ont été acquises suite à la découverte au Cailar (Gard, France), à partir de 2003, d’un ensemble de crânes humains fragmentés, d’armement manipulé et de plusieurs dizaines de monnaies, dispersés dans les phases de remblaiement d’une place publique entre la fin du IVe et la fin du IIIe s av. n. è. Cette dernière appartient à une agglomération fortifiée fondée dès le VIe s. av. n. è. Les fragments de crânes trouvés sur ce site constituent le sujet de cette étude. Ces os forment un corpus assez différent des restes généralement associés aux têtes coupées : ils sont nombreux, très fragmentés et largement mélangés et dispersés dans les couches. Pour comprendre les évènements qui ont conduit à la création d’un tel assemblage, il a été nécessaire de mettre en place des outils adaptés à leur étude. Après une remise en contexte archéologique régionale et locale, ce travail se propose de présenter les méthodes de l’archéothanatologie adaptées à l’étude de ce type d’ossements (quantification, modification osseuses). Dans un deuxième temps, sont détaillés l’outil d’enregistrement créé pour optimiser l’étude (base de données/géodatabase, SIG), et les méthodes d’analyses spatiales retenues pour étudier non seulement les traces et les fractures des pièces osseuses, mais aussi leur répartition sur le terrain. Les résultats obtenus sont multiples : données quantitatives et taphonomiques précises sur l’assemblage, proposition d’une méthode inédite pour l’analyse de la découpe et de la fragmentation sur des crânes humains fragmentés, analyse poussée de la répartition spatiale dans les trois dimensions. Tous ces éléments permettent de proposer des hypothèses solides quant à la chaîne opératoire qui concerne les têtes coupées : mode de récupération, traitement, rejet, mise en place du dépôt. Ce travail permet également de suggérer des pistes à approfondir ou à abandonner dans les méthodes usuelles d’analyses des grands ensembles fragmentés et dispersés
Once only known from Classical accounts, the practice of collecting and curating human heads by certain Iron Age groups in southern France has, for more than a century now, been evinced by materials including stone carvings and human remains. In particular, new evidence has been brought to light at the site of Le Cailar (Gard), a fortified site occupied from the end of the 6th century BCE. Specially, excavations carried out since 2003 have revealed an extensive deposit accumulated from the end of the 4th until the end of the 3rd century BCE, comprising fragmented human crania, purposefully deformed armaments, and many dozens of coins scattered across a public plaza, beneath a thick layer of rubble. The human cranial fragments discovered on this plaza are the subject of this study. These bones form a corpus quite different from the remains generally associated with severed heads: they are numerous, very fragmented, and largely mixed and dispersed in the levels. In order to understand the events that led to the creation of the assemblage, it has been necessary to adapt tools to this study. After putting the site into its local and regional context, this work proposes to present bioarchaeological methods adapted to the study of these types of bone (especially, quantification and modification of the bone). In a second time, the recording tool created to optimize the study is presented (database / geodatabase, GIS), then the spatial analysis methods used to study, not only the traces and the fractures of the parts bones, but also their distribution on the field. There are a lot of results: precise quantitative and taphonomic data about the assemblage, proposition of new method to study cut marks and fracturing, a hitherto unparalleled understanding of the process of how crania were distributed across the site (this last measured in three dimensions). All these elements permit to propose solid hypotheses regarding the process by which these heads were produced: the means of recuperation, treatment, disposal, and deposition. This work also suggests which avenues of research will or won't be useful to pursue in future projects of a similar nature
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42

Maley, Lejla Bilal. "Teaming at a Distance: The Work Experience on Global Virtual Teams". Antioch University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=antioch1588265024091539.

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43

"Settlement dispersal, economic disintensification, and human health at Moundville". Tulane University, 2005.

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This research proposes a model of economic disintensification, applied to the Mississippi period chiefdom of Moundville, in Alabama. I hypothesized the post-A.D. 1300 population dispersal from Moundville to outlying sites would have resulted in economic disintensification. To evaluate this model, I proposed subsistence, settlement pattern, and health correlates of disintensification, and tested these correlates against data from the Moundville site. I reviewed the existing literature on Moundville subsistence, and found that the published data were insufficient for determining if disintensification had occurred. Next, I performed a settlement pattern analysis of the number, mean size, distribution and density of Moundville phase sites, and found that although population dispersal occurred, there was no firm evidence of disintensification. I also collected primary demographic and paleopathological data from Moundville phase human skeletal remains, and made a diachronic comparison of skeletal samples before and after population dispersal, to see if there were any differences in health or nutrition that would signal disintensification. I found no statistically significant differences in rates of disease, trauma, degenerative joint disease, dental pathology or dental wear between pre-dispersal and post-dispersal populations, indicating that disintensification did not take place The model of disintensification is upheld, and most of the archaeological correlates I proposed for disintensification are valid tests of the model. However, disintensification did not occur within the Moundville chiefdom. Instead, Moundville and the outlying communities in the chiefdom appear to have maintained close ties, and continued to act as a single entity in terms of subsistence and social connections, thereby leaving open the vectors of disease at consistent low levels throughout the Moundville era. I believe this low-level exposure partially accounts for the lack of clear distinctions in health between the subphases. Overall, people appear to have maintained good health and an adequate diet across time, regardless of population movements and political change. The dispersal of Moundville's population after A.D. 1300 in no way represents 'the beginning of the end' of the chiefdom, but rather an organizational improvement that maintained the social and salutary status quo to the benefit of outlying communities and the residents of Moundville alike
acase@tulane.edu
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44

Rothlisberger, John D. "Human-mediated dispersal of aquatic nonindigenous species impacts and interventions /". 2009. http://etd.nd.edu/ETD-db/theses/available/etd-08302009-164109/.

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45

Lefevre, Kara Lynn. "The Influence of Human Disturbance on Avian Frugivory and Seed Dispersal in a Neotropical Rainforest". Thesis, 2008. http://hdl.handle.net/1807/11223.

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Habitat loss and disturbance due to human activity are major causes of global biodiversity decline. Beyond outright species loss, one potential outcome is modification of species interactions that are integral to ecosystem functioning. To investigate this possibility, I asked whether human activity influences avian frugivory and seed dispersal, bird-fruit interactions that facilitate plant reproduction. On Tobago (West Indies), I compared patterns of frugivory in three adjacent rainforest habitats along a gradient of increasing disturbance: primary forest in a reserve, unprotected intermediate forest outside the reserve, and nearby forest that was moderately disturbed by subsistence resource use. I assessed plant and bird community composition, seedling species, fruit removal, and bird fecal samples, to estimate human effects on seed dispersal and plant recruitment in this ecosystem. Disturbed forest had different species assemblages than primary forest, characterized by more light-demanding plants, more birds, and a shift in the relative abundance of avian feeding guilds: insectivores and frugivores declined, while nectarivores and omnivores increased. Canopy cover declined with disturbance; along with plant abundance, this explained much of the variation in bird species composition. The rate of avian fruit consumption in removal experiments varied considerably but tended to be highest in primary forest. Fecal samples showed that fruit composition of avian diets also varied with disturbance; birds captured in disturbed forest consumed more seeds from light-demanding plants. Seeds in the samples provided evidence of some seed transfer between habitats—from disturbed forest into the reserve and vice versa. Seedling composition was consistent with plant species fruiting in the same study plots, and illustrated some successful recruitment of light-demanding plants in primary forest and shade-tolerant plants in disturbed forest. Notably, the plant community of intermediate forest was more similar to disturbed than primary forest. This suggests that habitat adjacent to areas of human activity can be susceptible to ecological change, even though it does not experience the same direct disturbance. In summary, the unprotected portion of Tobago’s rainforest has a markedly different plant and bird community than the forest reserve, and my results indicate that avian frugivory and seed dispersal can be influenced by moderate human activity.
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46

"Spread Rate Estimation and the Role of Spatial Configuration and Human Behavior". Master's thesis, 2012. http://hdl.handle.net/2286/R.I.15143.

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abstract: The spread of invasive species may be greatly affected by human responses to prior species spread, but models and estimation methods seldom explicitly consider human responses. I investigate the effects of management responses on estimates of invasive species spread rates. To do this, I create an agent-based simulation model of an insect invasion across a county-level citrus landscape. My model provides an approximation of a complex spatial environment while allowing the "truth" to be known. The modeled environment consists of citrus orchards with insect pests dispersing among them. Insects move across the simulation environment infesting orchards, while orchard managers respond by administering insecticide according to analyst-selected behavior profiles and management responses may depend on prior invasion states. Dispersal data is generated in each simulation and used to calculate spread rate via a set of estimators selected for their predominance in the empirical literature. Spread rate is a mechanistic, emergent phenomenon measured at the population level caused by a suite of latent biological, environmental, and anthropogenic. I test the effectiveness of orchard behavior profiles on invasion suppression and evaluate the robustness of the estimators given orchard responses. I find that allowing growers to use future expectations of spread in management decisions leads to reduced spread rates. Acting in a preventative manner by applying insecticide before insects are actually present, orchards are able to lower spread rates more than by reactive behavior alone. Spread rates are highly sensitive to spatial configuration. Spatial configuration is hardly a random process, consisting of many latent factors often not accounted for in spread rate estimation. Not considering these factors may lead to an omitted variables bias and skew estimation results. The ability of spread rate estimators to predict future spread varies considerably between estimators, and with spatial configuration, invader biological parameters, and orchard behavior profile. The model suggests that understanding the latent factors inherent to dispersal is important for selecting phenomenological models of spread and interpreting estimation results. This indicates a need for caution when evaluating spread. Although standard practice, current empirical estimators may both over- and underestimate spread rate in the simulation.
Dissertation/Thesis
M.S. Biology 2012
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47

Jesse, Ruth [Verfasser]. "Natural or human mediated : biogeography of widespread Mediterranean invertebrates with poor dispersal capacities / von Ruth Jesse". 2011. http://d-nb.info/1013124642/34.

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48

Kristensen, Kurt A. "Human disturbance and seed dispersal by understory avian frugivores key elements in the maintenance of tropical forest diversity /". 1993. http://catalog.hathitrust.org/api/volumes/oclc/28653187.html.

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49

Chaves, Patrícia Alexandra Pereira. "Response of avian and mammal seed dispersal networks, to human induced forest edges in a sub-humid forest". Master's thesis, 2018. http://hdl.handle.net/10451/35506.

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Tese de mestrado, Biologia da Conservação, Universidade de Lisboa, Faculdade de Ciências, 2018
A destruição florestal de origem antropogénica e a perda de habitat são as principais ameaças à biodiversidade na actual crise de extinção do Antropoceno. Quando consideramos esse impacto em ecossistemas ricos em espécies como as florestas tropicais, a perda de grandes frugívoros leva à diminuição do serviço de dispersão, a alteração de padrões de recrutamento de árvores e abundância relativa de espécies. Estas paisagens têm sido continuamente convertidas em zonas de pastoreio e cultivo, resultando em manchas reduzidas de floresta intercaladas por sistemas modificados. A dispersão de sementes é uma função dos ecossistemas criticamente importante, sendo essencial para lidar com a fragmentação de paisagens, sobre-exploração de recursos, invasões biológicas e até alterações climáticas. Este serviço depende em grande parte das relações entre plantas e animais frugívoros, que funcionam como uma rede de dispersão. As ferramentas derivadas da teoria de rede têm permitido compreender estes padrões de interação entre espécies, providenciando uma perspetiva abrangente do funcionamento da comunidade. Em África as redes de dispersão são ainda pouco estudadas, constituindo um facto alarmante devido à defaunação contínua por todo o continente. A Guiné-Bissau possui uma das últimas florestas primárias sub-humidas de África, onde está incluído o Parque Nacional de Cantanhez. A área do parque tem sofrido alterações ao longo dos anos, vendo assim a sua floresta já naturalmente fragmentada sujeita a aumentos de pressão de actividades antropogénicas, com conversão de terrenos para agricultura. Este trabalho tem como principal objectivo explorar as consequências da indução antropogénica de margens de floresta, através da comparação de redes de dispersão entre floresta madura e orla, em duas manchas de floresta integradas no Parque Nacional de Cantanhez. Pretende-se também compreender o papel de cada espécie na rede, e como estas poderão afectar o serviço de dispersão providenciado às plantas. Adicionalmente, espera-se compreender se existe influência do tipo de habitat e disponibilidade de frutos na riqueza e abundância de frugívoros e plantas. Para tal realizaram-se observações focais de árvores ao longo de transectos na floresta madura e nas orlas das manchas de floresta de Lauchande e Madina. Foram identificados frugívoros e registados os eventos de consumo ou transporte de frutos. Adicionalmente registou-se o número de árvores com frutos maduros ao longo dos transectos. As redes de dispersão foram posteriormente construídas através da análise de matrizes de interação, considerando o número de eventos de consumo de frutos por cada espécie de frugívoro. Foram identificadas mais interações na floresta madura, sendo que os frutos mais consumidos pertenciam a Ficus sp., Antiaris toxicaria e Strombosia pustulata, enquanto na margem as Ficus sp. foram o recurso mais amplamente preferido. Os maiores consumidores na floresta madura foram Ceratogymna elata, Treron calvus e Cercopithecus mona, enquanto na orla foram os Ploceus sp., Pycnonotus barbatus e Cercopithecus mona. Grandes frugívoros como calaus e primatas foram mais comuns na floresta madura, e a rede neste habitat estava mais ligada, com maior equitabilidade de interações e maior robustez a extinções tanto de plantas como de frugívoros. A estrutura de rede foi similar entre habitats, com o mesmo número de espécies de plantas, e apenas mais um frugívoro na floresta madura. Para ambos, foram detectados baixos valores de aninhamento, conectividade, especialização (H2’) e modularidade, em contrapartida a equitabilidade das interações foi elevada. A sobreposição de nicho foi baixa e a robustez elevada para as plantas e frugívoros das duas redes. No que diz respeito à importância das espécies de um nível da rede para as espécies no nível oposto, C. elata, C. mona e Pan troglodytes foram as mais importantes, enquanto as espécies de árvores foram a A. toxicaria, Ficus sp., e S. pustulata. Para a rede da orla, as espécies de árvores mais importantes coincidiram com as da floresta madura e os frugívoros mais importantes foram Ploceus sp., P. barbatus e C. mona. Métricas como o Krisk, permitiram a criação de uma hierarquia do risco e vulnerabilidade da rede à perda individual de espécies, sendo que A. toxicaria e Ficus sp., foram respetivamente as mais preocupantes para a floresta madura e a margem. Todas as espécies de frugívoros e plantas nas duas redes, foram consideradas periféricas em relação ao papel que desempenham na rede, à excepção de Parinari excelsa e A. toxicaria, identificadas como conectoras de diferentes comunidades para a floresta madura e a orla respectivamente. A disponibilidade de frutos foi superior na floresta madura, mas a abundância e riqueza de frugívoros foi superior na orla. O facto de a floresta madura apresentar maior conectividade e maior equitabilidade de interação, poderá ser explicado pela maior presença de grandes frugívoros neste habitat. Para além disso, os baixos níveis de especialização e equitabilidade de interação resultam em elevada robustez para ambas as redes devido a redundância na rede, que providencia vias alternativos para a persistência da rede aquando a extinção de uma espécie. Dos vários módulos que compõe as redes, alguns incluíam aves de grande porte como calaus, e primatas. É possível que estes módulos sejam formados por espécies com limitações morfológicas e funcionais semelhantes, como a abertura do bico e o tamanho dos frutos. Árvores como A. toxicaria e P. excelsa, possíveis conectoras, com sementes grandes, foram consumidas por uma vasta gama de frugívoros de diferentes tamanhos, sendo que a forma de tratamento dos mesmos difere. Os frugívoros mais pequenos tendem a extrair a polpa e a deixar cair as sementes debaixo da planta-mãe, enquanto os primatas as transportam para longe nas suas bochechas. Outras árvores como Ficus sp. e S. pustulata possuem elevada importância para os frugívoros, sendo que as primeiras são consideradas recursos chave em florestas tropicais e consumidas por quase todos os frugívoros no estudo, enquanto a última parece estar mais associada à dieta de grandes frugívoros. Calaus e primatas apresentaram maior importância na floresta madura, sendo que o seu papel como dispersores já está amplamente documentado. Os seu grandes home ranges, a sua capacidade de se deslocarem entre manchas de habitat e atravessarem zonas degradas, e a capacidade de voo no caso dos calaus, e a sua capacidade de consumirem grandes frutos, resulta num aumento da sua importância para a dispersão e restauração de zonas degradadas. Nas margens, esse papel recai sobre Ploceus sp. e P. barbatus, sendo que o papel de dispersão para o primeiro não está muito estudado, enquanto o último é considerado um importante dispersor para uma espécie de pequeno tamanho. A maior abundância de potenciais dispersores na orla poderá dever-se ao maior número de visitantes da floresta aí registados. Esta maior ocorrência na margem pode também dever-se à baixa heterogeneidade da vegetação, árvores amplamente visíveis e elevada abundância de frugívoros nas áreas de cultivo circundantes. A dispersão de sementes é um importante condutor da regeneração de várias espécies de plantas. Estudos como este são relevantes porque permitem aceder à estrutura e funcionamento desta função ecológica numa perspetiva integrativa de rede. Para além disso, a identificação de árvores e potenciais dispersores mais importantes, permite propor medidas especificas, como a de plantação de determinadas espécies em zonas de forma a atrair frugívoros e as sementes que transportam. A identificação de potenciais dispersores permite ainda acompanhar o estado das suas populações e propor medidas direccionadas para a sua conservação. Em suma, medidas de conservação para o PNC, devem ter em conta os papeis de todos os componentes da rede de dispersão e os comportamentos das espécies que as compõem, procurando uma abordagem que tenha em conta o contexto regional e cultural do parque.
Human induced forest destruction and habitat loss are the current main threats to biodiversity. Impacts on species rich ecosystems such as tropical forests are considered, along with the abundance of mutualistic relationships they include, the loss of a species, may have unpredictable and deleterious consequences in the continuity of these ecological processes. Most tropical plant species rely on animals to disperse their seeds, thus studying the disruption of mutualistic networks becomes urgent in fragmentation scenarios. In the last couple of decades ecologists have been using the network theory as a tool to understand the pattern of mutualistic interactions. However, few are the studies that use this tool to compare populations in different types of strata or habitat. In Africa, seed dispersal networks are poorly studied, which is alarming considering the increasing defaunation in the continent. Guinea-Bissau contains one of the last primary sub-humid forest in Africa, where the National Park of Cantanhez (CNP) is included. The area of the park has been continuously converted for agriculture practices and the forest increasingly fragmented. The goal of this work is to explore the consequences of induced forest edges, by comparing seed dispersal networks between mature forest and forest edge, in two forest patches within the CNP. Additionally, I aim to understand the role of each species within the network, and how they may affect the seed dispersal service provided to plants. Focal tree observations were carried along transects at the edge and mature forest in two forest remnants of the Cantanhez National Forest (Guinea Bissau) for 39 days, and fruit consumption events were registered. Additionally, trees along each transect were inspected for ripe fruits to test the influence of fruit availability on the frugivore community. Fruit availability was higher at the mature forest whereas frugivore abundance and richness was higher at the forest edge, mostly due to an increase in forest visitors. The structure of plant frugivore networks was quite similar in the two habitats, with low nestedness, connectance, specialization (H2’) and modularity. Interaction evenness was quite high for both. Niche overlap was low, and robustness was high for frugivore level and plant level in both networks. Regarding species roles, most species were peripheral, with only one connector detected for each habitat. In the mature forest there was a prevalence of large bodied frugivores, whereas small bodied frugivores were more abundant at the edge. Species such as the Yellow casqued hornbill, the Bark cloth tree and the Guinea Plum, pose the highest risk for the cohesion of the network of interactions if they go extinct for the mature forest, whereas Weaver, Fig trees and the Bark cloth tree bear the same roles at the forest edge. These results suggest that the dispersal by large bodied frugivores may be hindered at the forest edges. Moreover, mature forest had higher interaction evenness, slightly higher connectance and higher robustness for plants and frugivores, which may be explained by the increase in the importance of large bodied frugivores. Nevertheless, both networks had low to moderate nestedness, modularity and specialization, resulting in functional redundancy and network robustness in both habitats. These results are positive, but there is still a need for more information on how seed dispersers are moving between the two habitats, and how effectively is the service being provided.
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Pflüger, Femke. "Advancing our understanding of animal dispersal and functional connectivity in human-altered landscapes: conceptual considerations and their empirical and simulation-based demonstration". Doctoral thesis, 2019. http://hdl.handle.net/21.11130/00-1735-0000-0005-1461-7.

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