Letteratura scientifica selezionata sul tema "Interaction niche"
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Articoli di riviste sul tema "Interaction niche"
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Badali, Matthew, e Anton Zilman. "Effects of niche overlap on coexistence, fixation and invasion in a population of two interacting species". Royal Society Open Science 7, n. 2 (febbraio 2020): 192181. http://dx.doi.org/10.1098/rsos.192181.
Testo completoAbstract (sommario):
Synergistic and antagonistic interactions in multi-species populations—such as resource sharing and competition—result in remarkably diverse behaviours in populations of interacting cells, such as in soil or human microbiomes, or clonal competition in cancer. The degree of inter- and intra-specific interaction can often be quantified through the notion of an ecological ‘niche’. Typically, weakly interacting species that occupy largely distinct niches result in stable mixed populations, while strong interactions and competition for the same niche result in rapid extinctions of some species and fixations of others. We investigate the transition of a deterministically stable mixed population to a stochasticity-induced fixation as a function of the niche overlap between the two species. We also investigate the effect of the niche overlap on the population stability with respect to external invasions. Our results have important implications for a number of experimental systems.
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Allgeier, Jacob E., Thomas C. Adam e Deron E. Burkepile. "The importance of individual and species-level traits for trophic niches among herbivorous coral reef fishes". Proceedings of the Royal Society B: Biological Sciences 284, n. 1856 (14 giugno 2017): 20170307. http://dx.doi.org/10.1098/rspb.2017.0307.
Testo completoAbstract (sommario):
Resolving how species compete and coexist within ecological communities represents a long-standing challenge in ecology. Research efforts have focused on two predominant mechanisms of species coexistence: complementarity and redundancy. But findings also support an alternative hypothesis that within-species variation may be critical for coexistence. Our study focuses on nine closely related and ecologically similar coral reef fish species to test the importance of individual- versus species-level traits in determining the size of dietary, foraging substrate, and behavioural interaction niches. Specifically, we asked: (i) what level of biological organization best describes individual-level niches? and (ii) how are herbivore community niches partitioned among species, and are niche widths driven by species- or individual-level traits? Dietary and foraging substrate niche widths were best described by species identity, but no level of taxonomy explained behavioural interactions. All three niches were dominated by only a few species, contrasting expectations of niche complementarity. Species- and individual-level traits strongly drove foraging substrate and behavioural niches, respectively, whereas the dietary niche was described by both. Our findings underscored the importance of species-level traits for community-level niches, but highlight that individual-level trait variation within a select few species may be a key driver of the overall size of niches.
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Mauretti, Arianna, Sergio Spaans, Noortje A. M. Bax, Cecilia Sahlgren e Carlijn V. C. Bouten. "Cardiac Progenitor Cells and the Interplay with Their Microenvironment". Stem Cells International 2017 (2017): 1–20. http://dx.doi.org/10.1155/2017/7471582.
Testo completoAbstract (sommario):
The microenvironment plays a crucial role in the behavior of stem and progenitor cells. In the heart, cardiac progenitor cells (CPCs) reside in specific niches, characterized by key components that are altered in response to a myocardial infarction. To date, there is a lack of knowledge on these niches and on the CPC interplay with the niche components. Insight into these complex interactions and into the influence of microenvironmental factors on CPCs can be used to promote the regenerative potential of these cells. In this review, we discuss cardiac resident progenitor cells and their regenerative potential and provide an overview of the interactions of CPCs with the key elements of their niche. We focus on the interaction between CPCs and supporting cells, extracellular matrix, mechanical stimuli, and soluble factors. Finally, we describe novel approaches to modulate the CPC niche that can represent the next step in recreating an optimal CPC microenvironment and thereby improve their regeneration capacity.
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Schirmer, Annika, Julia Hoffmann, Jana A. Eccard e Melanie Dammhahn. "My niche: individual spatial niche specialization affects within- and between-species interactions". Proceedings of the Royal Society B: Biological Sciences 287, n. 1918 (15 gennaio 2020): 20192211. http://dx.doi.org/10.1098/rspb.2019.2211.
Testo completoAbstract (sommario):
Intraspecific trait variation is an important determinant of fundamental ecological interactions. Many of these interactions are mediated by behaviour. Therefore, interindividual differences in behaviour should contribute to individual niche specialization. Comparable with variation in morphological traits, behavioural differentiation between individuals should limit similarity among competitors and thus act as a mechanism maintaining within-species variation in ecological niches and facilitating species coexistence. Here, we aimed to test whether interindividual differences in boldness covary with spatial interactions within and between two ecologically similar, co-occurring rodent species ( Myodes glareolus , Apodemus agrarius ). In five subpopulations in northeast Germany, we quantified individual differences in boldness via repeated standardized tests and spatial interaction patterns via capture–mark–recapture ( n = 126) and automated VHF telemetry ( n = 36). We found that boldness varied with space use in both species. Individuals of the same population occupied different spatial niches, which resulted in non-random patterns of within- and between-species spatial interactions. Behavioural types mainly differed in the relative importance of intra- versus interspecific competition. Within-species variation along this competition gradient could contribute to maintaining individual niche specialization. Moreover, behavioural differentiation between individuals limits similarity among competitors, which might facilitate the coexistence of functionally equivalent species and, thus, affect community dynamics and local biodiversity.
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Costa-Pereira, Raul, Márcio S. Araújo, Franco L. Souza e Travis Ingram. "Competition and resource breadth shape niche variation and overlap in multiple trophic dimensions". Proceedings of the Royal Society B: Biological Sciences 286, n. 1902 (maggio 2019): 20190369. http://dx.doi.org/10.1098/rspb.2019.0369.
Testo completoAbstract (sommario):
Competition plays a central role in the maintenance of biodiversity. A backbone of classic niche theory is that local coexistence of competitors is favoured by the contraction or divergence of species' niches. However, this effect should depend on the diversity of resources available in the local environment, particularly when resources vary in multiple ecological dimensions. Here, we investigated how available resource breadth (i.e. prey diversity) and competition together shape multidimensional niche variation (between and within individuals) and interspecific niche overlap in 42 populations of congeneric tropical frog species. We modelled realized niches in two key trophic dimensions (prey size and carbon stable isotopes) and sampled available food resources to quantify two-dimensional resource breadth. We found a 14-fold variation in multidimensional population niche width across populations, most of which was accounted for by within-individual diet variation. This striking variation was predicted by an interaction whereby individual niche breadth increased with resource breadth and decreased with the number of congeneric competitors. These ecological gradients also interact to influence the degree of niche overlap between species, which surprisingly decreased with population total niche width, providing novel insights on how similar species can coexist in local communities. Together, our results emphasize that patterns of exploitation of resources in multiple dimensions are driven by both competitive interactions and extrinsic factors such as local resource breadth.
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Richards, Greg. "Rethinking niche tourism: The example of backpacking". Croatian Regional Development Journal 2, n. 1 (1 giugno 2021): 1–10. http://dx.doi.org/10.2478/crdj-2021-0004.
Testo completoAbstract (sommario):
Abstract This conceptual paper re-evaluates the concept of niches in tourism markets. As many regions are now attempting to address niche markets in tourism as a development strategy, understanding of the dynamics of niche markets is crucial. Current approaches are often limited to seeing niche markets as simple subsectors of larger consumer markets. We argue for a broader view of market niches as forms of social rituals involving both consumers and producers with a mutual focus of attention. Based on the work of Randall Collins we examine how interaction rituals are produced and maintained, and how these are also reflected in niche markets, such as backpacking. We illustrate the how backpacking produces a mutual focus of attention and boundaries to outsiders, helping to sustain the niche over the longer term. This analysis has implications for producers hoping to tap into niche markets, as they too need to become part of the niche community.
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Adiloglu, Ali Kudret. "The Interaction of Diet, Microbiota, and Antimicrobial Peptides in the Gastrointestinal Ecosystem". Niche Journal 3, n. 2 (22 febbraio 2016): 28–32. http://dx.doi.org/10.5152/niche.2016.218.
Testo completo
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Khattab, Shaimaa, Manal El Sorady, Ashraf El-Ghandour, Giuseppe Visani e Pier Paolo Piccaluga. "Hematopoietic and leukemic stem cells homeostasis: the role of bone marrow niche". Exploration of Targeted Anti-tumor Therapy 5, n. 5 (15 agosto 2024): 1027–55. http://dx.doi.org/10.37349/etat.2024.00262.
Testo completoAbstract (sommario):
The bone marrow microenvironment (BMM) has highly specialized anatomical characteristics that provide a sanctuary place for hematopoietic stem cells (HSCs) that allow appropriate proliferation, maintenance, and self-renewal capacity. Several cell types contribute to the constitution and function of the bone marrow niche. Interestingly, uncovering the secrets of BMM and its interaction with HSCs in health paved the road for research aiming at better understanding the concept of leukemic stem cells (LSCs) and their altered niche. In fact, they share many signals that are responsible for interactions between LSCs and the bone marrow niche, due to several biological similarities between LSCs and HSCs. On the other hand, LSCs differ from HSCs in their abnormal activation of important signaling pathways that regulate survival, proliferation, drug resistance, invasion, and spread. Targeting these altered niches can help in better treatment choices for hematological malignancies and bone marrow disorders in general and acute myeloid leukemia (AML) in particular. Moreover, targeting those niches may help in decreasing the emergence of drug resistance and lower the relapse rate. In this article, the authors reviewed the most recent literature on bone marrow niches and their relations with either normal HSCs and AML cells/LSC, by focusing on pathogenetic and therapeutic implications.
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Kuek, Vincent, Anastasia M. Hughes, Rishi S. Kotecha e Laurence C. Cheung. "Therapeutic Targeting of the Leukaemia Microenvironment". International Journal of Molecular Sciences 22, n. 13 (26 giugno 2021): 6888. http://dx.doi.org/10.3390/ijms22136888.
Testo completoAbstract (sommario):
In recent decades, the conduct of uniform prospective clinical trials has led to improved remission rates and survival for patients with acute myeloid leukaemia and acute lymphoblastic leukaemia. However, high-risk patients continue to have inferior outcomes, where chemoresistance and relapse are common due to the survival mechanisms utilised by leukaemic cells. One such mechanism is through hijacking of the bone marrow microenvironment, where healthy haematopoietic machinery is transformed or remodelled into a hiding ground or “sanctuary” where leukaemic cells can escape chemotherapy-induced cytotoxicity. The bone marrow microenvironment, which consists of endosteal and vascular niches, can support leukaemogenesis through intercellular “crosstalk” with niche cells, including mesenchymal stem cells, endothelial cells, osteoblasts, and osteoclasts. Here, we summarise the regulatory mechanisms associated with leukaemia–bone marrow niche interaction and provide a comprehensive review of the key therapeutics that target CXCL12/CXCR4, Notch, Wnt/b-catenin, and hypoxia-related signalling pathways within the leukaemic niches and agents involved in remodelling of niche bone and vasculature. From a therapeutic perspective, targeting these cellular interactions is an exciting novel strategy for enhancing treatment efficacy, and further clinical application has significant potential to improve the outcome of patients with leukaemia.
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Gottfried, Iwona, Bartosz Borczyk e Tomasz Gottfried. "Snakes use microhabitats created by the great capricorn beetle Cerambyx cerdo in southwest Poland". Herpetozoa 32 (12 giugno 2019): 133–35. http://dx.doi.org/10.3897/herpetozoa.32.e35824.
Testo completoAbstract (sommario):
Niche engineering is considered one of the most important interspecific interactions that shape ecosystems, but this kind of interaction network has not been sufficiently studied so far. Here we present the first observation of grass snake Natrixnatrix in the galleries of Cerambyxcerdo. We recorded three grass snake individuals basking and hiding inside the C.cerdo galleries. We suggest the presence of this beetle species may create new environmental niches and improve habitat quality for snakes and other vertebrates.
Tesi sul tema "Interaction niche"
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Grégoire, Murielle. "Polynucléaires neutrophiles, cellules stromales, lymphocytes B : interaction tripartite dans la niche des lymphomes B". Thesis, Rennes 1, 2014. http://www.theses.fr/2014REN1S156/document.
Testo completoAbstract (sommario):
Les polynucléaires neutrophiles ont longtemps été considérés comme des cellules n’intervenant que dans la réponse immune innée. Cependant, au cours de ces dernières années, de nombreuses publications suggèrent que ces cellules, retrouvées au sein du microenvironnement de nombreux cancers, pourraient également jouer un rôle dans la tumorigénèse et la progression tumorale. Ces études mettent en évidence leur fréquence comme marqueur pronostique dans différents cancers solides, mais peu de travaux se sont intéressés à la caractérisation fonctionnelle de ces cellules dans la progression tumorale. Dans de nombreux cancers dont les lymphomes B issus du centre germinatif, les cellules tumorales, qui sont incapables de proliférer et de survivre seules, sont dépendantes de leur microenvironnement de soutien. Dans cette étude, nous avons évalué la fonctionnalité des polynucléaires neutrophiles dans la croissance des lymphomes B. Ainsi, nous avons démontré pour la première fois que les polynucléaires neutrophiles soutiennent directement la croissance et la survie des cellules tumorales de lymphomes B. De plus, un dialogue bidirectionnel existe entre les polynucléaires neutrophiles et les cellules stromales. D’une part, les cellules stromales soutiennent la survie des polynucléaires neutrophiles, qui en retour induisent les caractéristiques d’un stroma lymphoïde. L’induction de ce phénotype permet aux cellules stromales d’acquérir de meilleures capacités de soutien envers les cellules tumorales. Cette étude confirme donc que les polynucléaires neutrophiles sont une composante importante du microenvironnement tumoral, et pourraient devenir une nouvelle cible thérapeutique pour le traitement des lymphomes B issus du centre germinatifFor long time, neutrophils have only been considered as cells involved in the innate immune response. More recently, in descriptive publications, neutrophils were found in the microenvironment of many solid cancers, hypothesizing that they could also play a role in tumorigenesis and cancer progression. These studies highlighted the prognostic value of their frequency, but few of them focused on the functional characterization of these cells in tumor growth. In many cancers, including germinal centre-derived B-cell lymphomas, tumor cells are dependent on their microenvironment to proliferate and survive. In this study, we focused on the role of neutrophils in the progression of B-cell lymphomas, and for the first time we demonstrated that neutrophils directly support the growth and survival of tumor Bcells. In addition, we highlighted the existence of bidirectional cooperation between neutrophils and stromal cells. In one hand stromal cells support the survival of neutrophils. On the other hand, neutrophils induce a lymphoid stroma phenotype which is well known to enhance their supportive effect on tumor cells. This study demonstrates that neutrophils are a significant component of the tumor microenvironment and may be considered as a potential therapeutic target for the treatment of B-cell lymphomas
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Maby-El, Hajjami Hélène. "Microenvironnement et lymphomes B du centre germinatif : importance de la niche mésenchymateuse". Rennes 1, 2008. http://www.theses.fr/2008REN1S017.
Testo completoAbstract (sommario):
Le lymphome folliculaire (FL) est une pathologie tumorale se développant au dépens de lymphocytes B des centres germinatifs des ganglions. Il est caractérisé par une forte dépendance à un environnement ganglionnaire cellulaire et cytokinique complexe. La moelle osseuse fournit également une «niche» propice au développement du FL, puisqu’une infiltration tumorale est observée dans plus de 70% des cas au diagnostic, avec l'apparition ectopique d'un environnement de type ganglionnaire. L’originalité et le but de notre projet ont été d’étudier in vitro les cellules de FL dans le contexte de leur environnement de soutien, en nous intéressant plus particulièrement à deux compartiments mésenchymateux potentiellement impliqués dans la lymphomagenèse B: les cellules fibroblastiques réticulaires (FRC) et leur précurseur putatif, les cellules souches mésenchymateuses (CSM) présentes au niveau médullaire et ganglionnaire. Nous avons démontré que les CSM pouvaient acquérir l'ensemble des caractéristiques des FRC après stimulation par le tumor necrosis factor-α et la lymphotoxine-α1β2 ou après contact direct avec des cellules de FL, et devenaient ainsi capables de soutenir la migration, l'adhérence et la croissance des cellules de FL. Cependant, l’effet de soutien des CSM et FRC était inhibé suite à leur exposition à un environnement comportant de l’interféron-γ. En effet, ces cellules mésenchymateuses dans ce contexte développaient une activité indoléamine 2,3 dioxygénase, responsable d’effets antiprolifératif et pro-apoptotique sur les cellules tumorales. Ces résultats montrent l’importance et la complexité de l’environnement cellulaire et cytokinique au cours du FLFollicular lymphoma (FL) results from the malignant transformation of germinal center-derived B cells that accumulate within lymph nodes. This disease is characterized by an important crosstalk between non malignant cells and the tumoral compartment. Bone marrow also provides a preferential niche for FL malignant cells, since tumoral infiltration is found in up to 70% of FL cases at diagnosis, in association with the emergence of ectopic lymph node-like environment. The originality and the goal of our project were to study in vitro FL cells in respect of their supportive microenvironment. We focused our studies on mesenchymal cell compartments. Two cell populations seemed to be of great interest in B-cell lymphomagenesis: fibroblastic reticular cells (FRCs), and their postulated progenitors mesenchymal stem cells (MSCs). Indeed, cells with phenotypic and functional features of MSCs could be found not only in the medullar but also in the lymphoid compartments. We demonstrated that MSCs could acquire a complete phenotype of FRCs after stimulation with tumor necrosis factor-α and lymphotoxin-α1β2 or after a direct contact with FL cells, and were able to support migration, adhesion and growth of lymphoma B cells. However, the B cell-supportive properties of MSCs and FRCs were overruled following their pretreatment with interferon-γ. Indeed, IFN-γ-conditioned mesenchymal cells developed functional indoleamine 2, 3 dioxygenase activity, which was reponsible of both antiproliferative and proapoptotic effects on tumoral B cells. Our results underline the key role and the complexity of cellular and molecular environment in FL
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Sugimura, Ryohichi. "Non-canonical Wnt signaling maintains hematopoietic stem cell through Flamingo and Frizzled8 interaction in the niche". Thesis, Open University, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.580673.
Testo completoAbstract (sommario):
Wnt signaling is involved in self-renewal and maintenance ofhematopoietic stem cells (HSCs); however, the particular role of non-canonical Wnt signaling in regulating HSCs in vivo is largely unknown. Here I show Flamingo and Frizzled8, members of non-canonical Wnt signaling, both express in and functionally maintain quiescent long-term HSCs. Flamingo regulates Frizzled8 distribution at the interface between HSCs and N-cadherin + osteoblasts (N-cad+OBs that enrich osteoprogenitors) in the niche. I further show that N-cad+OBs predominantly express non-canonical Wnt ligands and inhibitors of canonical Wnt signaling under homeostasis. This non-canonical Wnt signaling is attenuated prior to activation of HSCs. In the activated HSCs, however, canonical Wnt signaling is enhanced. Mechanistically, non-canonical Wnt signaling mediated by Frizzled8 suppresses the Ca2+-NF AT- IFNy pathway and antagonizes canonical Wnt signaling in HSCs. My findings demonstrate that non-canonical Wnt signaling maintains quiescent long- term HSCs through Flamingo and Frizzled8 interaction in the niche.
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Costa, Paula Lemos da. "Variação intrapopulacional no uso do recurso: modelos teóricos e evidência empírica". Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/41/41134/tde-14102013-112513/.
Testo completoAbstract (sommario):
Tradicionalmente, nichos populacionais são descritos como a somatória de todos os recursos utilizados por uma população. Entretanto, diversos estudos mostram que indivíduos dentro de uma população podem usar recursos de forma distinta. Investigamos três maneiras pelas quais indivíduos podem variar quanto ao uso do recurso. Indivíduos podem apresentar a mesma preferência por presas, mas diferir na propensão à adição de novos itens alimentares em sua dieta (Preferências Compartilhadas); indivíduos podem apresentar a mesma presa preferida mas diferirem em suas presas alternativas (Refúgio Competitivo); ou indivíduos podem apresentar presas preferidas distintas (Preferências Distintas). Estudamos os padrões de interação que emergem sob os pressupostos de cada um dos modelos usando redes de interação entre indivíduos e os recursos que eles consomem. Dessa forma, para derivarmos as previsões de cada um dos modelos de uso de recurso, desenvolvemos modelos simples que geram redes de interação segundo regras que seguem os pressupostos dos modelos e confrontamos essas previsões com dados empíricos, comparando a estrutura dessa redes de interação. Encontramos que o modelo que menos se assemelha ao padrão de uso de recurso observado para as populações estudadas foi o modelo de Preferências Compartilhadas. Para as populações estudadas, a variação intrapopulacional na escolha de presas parece estar mais associada a diferenças nas sequências de preferências por presas entre indivíduos e não à propensão desses indivíduos em adicionarem novos recursos às suas dietas.Traditionally, a population\'s niche is described as the sum of all resources consumed by a population. However, several studies have highlighted that individuals within a population can use resources differently. We investigate three ways in which individuals can vary in their resource use. Individuals can show the same preference for prey, but differ in their likelihood of adding new prey to their diets (Shared Preferences); individuals can share the same top-ranked prey but differ in their alternative prey (Competitive Refuge); or individuals can have different top-ranked prey (Distinct Preferences). We studied the pattern of interaction that emerges under each model\'s assumption using interaction networks between individuals and the resources they consume. In this sense, to derive the predictions associated with each model of resource use, we developed simple models that generates interaction networks according to a set of rules that represent the assumptions of each model and then confronted these predictions with empirical data on interaction networks, by looking at the structure of these interaction networks. We found that the model that least resembles the pattern of resource use observed in the populations studied was the Shared Preferences model. For the studied populations, intrapopulation variation is not associated with individuals sharing the same rank sequence and differing in their willingness to add new resources to their diets. Instead, it seems that differences in the rank sequence of prey choice are more important in structuring the pattern of resource use in these populations.
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Escoriza, Daniel. "Factors regulating the invasion of two Mediterranean anurans. The role of niche conservatism, species interaction and habitat selection". Doctoral thesis, Universitat de Girona, 2015. http://hdl.handle.net/10803/300902.
Testo completoAbstract (sommario):
Amphibians are a group in worldwide decline. The factors that are causing this decline are not well known, but could be multifactorial, related to the recent expansion of pathogens and habitat disturbance. One of these factors related to the loss of habitat quality is the introduction of alien species. These species can compete with or prey on species of the recipient community, producing deep changes in the structure of these communities. For this reason it is a priority to know which factors act by facilitating the invasion process and which species could be more affected by the presence of this alien species.
In Catalonia has become established an alien frog, the painted frog. Introduced in the extreme south of France in the early XXth century, this species has expanded gradually, reaching the Llobregat delta to the south and Llanguedoc to the north. This region is rich in native species of amphibians, some of them endemic, and therefore it is necessary to know how this newcomer species interacts with each of these species. We have used a novel approach when analyzing these interactions, applying the theory of morphospaces. The morphospace is the range of morphological variation observed within a community. This morphology is correlated with the use of a niche, and hence the morphological similarities between the invasive and native species serve as a proxy to assess the functional overlap.
These analogies in morphospace were evaluated also in the area of native species and among other species of Discoglossus. The question asked is "Does the invasive species occupy a vacant niche, maintaining a similar morphological gap than that observed in the source assemblage and in the case of other species of the genus Discoglossus?”.Els amfibis són un grup en declivi a nivell mundial. Els factors que estan causant aquest declivi no són coneguts, però podria ser multifactorial, en relació amb l'expansió recent de certs patògens i les alteracions dels hàbitats. Un d'aquests factors que es relacionen amb la pèrdua de qualitat dels hàbitats és la introducció d'espècies exòtiques. Aquestes espècies poden competir o depredar sobre les espècies de la comunitat recipient, produint profundes alteracions en l'estructura d'aquestes comunitats. Per aquesta raó és prioritari conèixer que factors actuen facilitant el procés invasiu i quines espècies es poden veure més afectades per la presència d'una espècie exòtica. A Catalunya s'ha establert una espècie de anur d'origen africà, la granota pintada. Introduïda a l'extrem sud de França a inicis del segle XX, aquesta espècie s'ha anat expandint de forma progressiva, fins a arribar pel sud al delta del Llobregat i pel nord el Llenguadoc. Aquesta regió és rica en espècies natives d'amfibis, algunes d'elles endèmiques, i per tant cal conèixer com interacciona aquesta espècie recent arribada amb cadascuna d'aquestes espècies. Nosaltres hem utilitzat un enfocament nou en el moment d'analitzar aquestes interaccions, aplicant la teoria dels morfoespais. El morfoespai és el rang de variació morfològica que s'observa dins d'un acoblament. Aquesta morfologia es correlaciona amb l'ús d'un nínxol, i per tant les analogies morfològiques entre l'espècie invasora i les espècies natives poden servir com una aproximació per valorar el solapament funcional. Aquestes analogies en el morfoespai s'han avaluat també en l'area nativa de l'espècie i entre altres espècies de Discoglossus. La pregunta formulada és "ocupa l'espècie invasora un nínxol vacant, mantenint una distància morfològica similar que a l'acoblament d'origen i que altres espècies del gènere Discoglossus?".
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Nicvert, Lisa. "Méthodes statistiques et outils logiciels pour l'analyse et l'inférence de réseaux écologiques et le traitement de données multi-espèces". Electronic Thesis or Diss., Lyon 1, 2024. http://www.theses.fr/2024LYO10130.
Testo completoAbstract (sommario):
Les interactions entre espèces dans les communautés écologiques sont complexes : de nombreuses espèces peuvent interagir les unes avec les autres de façons variées et à différentes échelles spatiales et temporelles. De plus, ces réseaux d'interactions sont la résultante de multiples causes, engendrent de multiples processus et ont des conséquences parfois indirectes transmises au travers de la structure du réseau. Cette complexité nécessite une diversité d'approches pour comprendre les déterminants des interactions et prédire leurs effets dans les systèmes écologiques. Cette thèse étudie plusieurs aspects des réseaux d'interactions écologiques par une approche méthodologique qui se concentre sur la description, l'évaluation et le développement de méthodes statistiques et d'outils logiciels. Dans une première partie, j'étudie les causes de la structure des réseaux d'interactions en me concentrant sur les niches d'interactions et en utilisant la notion de concordance des traits entre espèces. Pour cela, j'utilise des méthodes de la famille de l'analyse des correspondances et j'applique et j'étends des méthodes de mise à l'échelle réciproque à l'analyse de réseaux bipartites. J'applique ces méthodes à l'analyse d'un réseau d'interactions plantes-frugivores d'une forêt de montagne péruvienne et je montre que les traits des espèces peuvent être reliés à leur largeur de niche. Dans une deuxième partie, j'étudie les conséquences des interactions au travers de leur influence sur la répartition spatio-temporelle des espèces. Pour cela, j'utilise des processus de Hawkes multivariés pour analyser des données de pièges photographiques. J'illustre ces modèles sur cinq mammifères de la savane sud-africaine et je montre des attractions et évitements entre plusieurs de ces espèces à courte échelle spatio-temporelle. Dans une troisième partie, je me penche sur l'analyse de données collectées par pièges photographiques. Je développe un package R pour nettoyer et standardiser ces données à l'usage du programme Snapshot Safari, ainsi qu'une application Shiny destinée à un usage plus général pour visualiser de données de façon interactive et reproductible. Cette thèse présente des méthodes statistiques et outils logiciels pour analyser des données écologiques complexes et améliorer la compréhension des réseaux d'interactions. Ces résultats ouvrent des perspectives nouvelles concernant l'analyse de données écologiques ainsi que les développement méthodologique en écologieInteractions between species in ecological communities are complex: many species can interact with each other in a variety of ways and at different spatial and temporal scales. Moreover, these interaction networks are the result of multiple causes, generate multiple processes and can have indirect effects transmitted through the structure of the network. This complexity calls for a variety of approaches to understand the determinants of interactions and predict their effects in ecological systems. This thesis studies several aspects of ecological interaction networks using a methodological approach that focuses on the description, evaluation and development of statistical methods and software tools. In a first part, I study causes of the structure of interaction networks, focusing on interaction niches and using the notion of trait matching between species. To this end, I use methods from the correspondence analysis family and apply and extend reciprocal scaling methods to the analysis of bipartite networks. I apply these methods to the analysis of a plant-frugivore interaction network in a Peruvian montane forest, and show that species traits can be related to their niche width. In a second part, I study the consequences of interactions through their influence on the spatio-temporal distribution of species. To this end, I use multivariate Hawkes processes to analyze camera trap data. I illustrate these models on five mammals from the South African savanna, showing attraction and avoidance between several of these species at a short spatio-temporal scale. In a third part, I consider camera trap data analysis. I develop a R package to clean and standardize camera trap data intended for the Snapshot Safari program, as well as a Shiny application intended for a more general use to visualize data in an interactive and reproducible way. This thesis presents statistical methods and software tools to analyze complex ecological data and improve our understanding of interaction networks. These results open new perspectives on ecological data analysis and methodological development in ecology
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Silva, Maria de Fátima de Oliveira Coutinho. "Concepções sobre desenvolvimento infantil de enfermeiros que atuam na Estratégia Saúde da Família". Universidade Federal da Paraíba, 2013. http://tede.biblioteca.ufpb.br:8080/handle/tede/6933.
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The aim of this research was to analyze the conceptions of child development for nurses working in the Family Health Strategy. This study is anchored in Social-Historical Theory of Vigotski, on the understanding that human development departs from the concept that all human organism is active and establishes successive interactions between the social and the biological basis of human behavior and the approach of the Niche Development of Harkness and Super, which provides insight on the quality of care and possible influences on child development in a given context. We conducted a field study, in the Family Health Units belonging to the Sanitary District III and it was used for data collection a questionnaire that captured the socio-demographic data, and a semi-structured interview, which was analyzed according to Bardin s Thematic Content Analysis. Participants were 38 nurses aged between 41-50 years, 30 were married, with children, and had an average of 20 years graduated. Regarding graduated studies, 35 participants were experts in Public Health and related areas and 32 underwent a Training Development Surveillance. Regarding time of service, 25 had around six years of activity in the Family Health Strategy. Applied and analyzed the interviews emerged a thematic class, ten categories, 27 sub-categories and 1.367 units of analysis. The results showed that the conceptions of nurses on child development are guided by the assumptions of the maturationist theory, transpiring in their speeches the actual theoretical construction of Health Ministry s guidelines for monitoring child development. Apprehends that nurses follow the protocols provided by Health Ministry found in the records or the Child Health Card for the children care and it sustains clearly that among the aspects of development evaluated by nurses predominating maintenance of a natural development conception, based on the existence of an intrinsic force from the child. This study finds these professionals as inconsistent and limited to the ideas of mothers on child development, reports that the process of child development is influenced by the family context, affective and environmental and guides mothers to stimulate child development, according to the contents of the Child Health Card or the age and developmental milestones. The study also reveals that majority of nurses do not realize the systematic care for children up to two years of age, judge their own performance in a fragmented way but realize the need to improve the children care. Apprehends, generally, that there are contradictions in the nurses conceptions, it concludes the need to create spaces for the reflection of these professionals, so that they rethink their conceptions from the context of their work place, and take into account the multiple variables in the understanding of the child, family and development.
O objetivo desta pesquisa foi analisar as concepções sobre desenvolvimento infantil de enfermeiros que atuam na Estratégia Saúde da Família. O mesmo se ancorou na Teoria Sócio-Histórica de Vigotski, na compreensão de que o desenvolvimento humano parte da concepção que todo organismo humano é ativo e institui sucessivas interações entre as condições sociais e a base biológica do comportamento humano e na abordagem do Nicho do Desenvolvimento de Harkness e Super, na qual permite compreender sobre a qualidade do cuidado e possíveis influências no desenvolvimento infantil situado em um determinado contexto. Foi realizado um estudo de campo, nas Unidades de Saúde da Família pertencentes ao Distrito Sanitário III e utilizou-se para a coleta de dados um questionário que captava os dados sócio-demográficos e uma entrevista semi-estruturada, na qual foi analisada de acordo com Análise de Conteúdo Temática de Bardin. Participaram da pesquisa 38 enfermeiras com idades variando entre 41 a 50 anos, destas, 30 eram casadas, com filhos e apresentavam em média 20 anos de graduadas. Em relação à pós-graduação, 35 participantes eram especialistas em Saúde Coletiva e áreas a fins e 32 realizaram curso de Capacitação em Vigilância do Desenvolvimento. Quanto ao tempo de serviço, 25 apresentavam em torno de seis anos de atividades na Estratégia Saúde da Família. Das entrevistas aplicadas e analisadas, emergiram uma classe temática, dez categorias, 27 subcategorias e 1.367 unidades de análises. Os resultados apontaram que as concepções das enfermeiras sobre desenvolvimento infantil estão pautadas nos pressupostos da teoria maturacionista, transparecendo nos seus discursos a própria construção teórica das diretrizes de acompanhamento do desenvolvimento infantil do Ministério da Saúde. Apreende-se que as enfermeiras seguem os protocolos disponibilizados pelo Ministério da Saúde encontrados nos prontuários ou no Cartão de Saúde da Criança para o atendimento às crianças e percebe-se que dentre os aspectos do desenvolvimento avaliados pelas enfermeiras, predominam a manutenção de uma concepção de desenvolvimento natural, pautada na existência de uma força intrínseca à criança. Julgam ainda esses profissionais como inconsistentes e limitados às ideias das mães sobre desenvolvimento infantil, relatam que o processo de desenvolvimento infantil sofre influência do contexto familiar, afetivo e ambiental e orientam as mães para estimular o desenvolvimento infantil, de acordo com o conteúdo do Cartão de Saúde da Criança ou pela idade e marcos do desenvolvimento. Revela também o estudo, que a maioria das enfermeiras não realiza o atendimento sistemático à criança até aos dois anos de idade, julgam a sua própria atuação fragmentada, mas percebem a necessidade de melhorar o atendimento à criança. Apreende-se de um modo geral, que há contradições nas concepções dos enfermeiros, conclui-se a necessidade de criar espaços de reflexão para estes profissionais, a fim de que os mesmos repensem suas concepções a partir do contexto do seu lugar no trabalho, de modo que levem em consideração as múltiplas variáveis de entendimento sobre criança, família e desenvolvimento.
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Hornoy, Benjamin. "Processus évolutifs contribuant au succès envahissant de l'ajonc d'Europe, Ulex europaeus". Phd thesis, Université Rennes 1, 2012. http://tel.archives-ouvertes.fr/tel-00740154.
Testo completoAbstract (sommario):
Etudier les invasions biologiques est essentiel dans le cadre de la conservation de la biodiversité. De plus, elles représentent de véritables expérimentations grandeur nature pour appréhender les processus écologiques et évolutifs. La problématique de cette thèse est d‟étudier la contribution de processus évolutifs dans le succès envahissant de l‟ajonc d‟Europe, Ulex europaeus, à travers le monde, notamment en relation avec la perte de ses ennemis naturels (Enemy Release). La première partie s‟intéresse à l‟évolution de l‟ajonc dans sa zone d‟origine et au moment de l‟introduction dans de nouvelles régions, (i) en synthétisant les résultats concernant le polymorphisme de traits et la plasticité phénotypique, (ii) en couplant des données historiques et moléculaires pour inférer le mode d‟introduction de l‟ajonc dans le monde et ses conséquences sur la diversité génétique introduite. La deuxième partie s‟intéresse à l‟évolution post-introduction des populations d‟ajonc. Elle s‟appuie principalement sur des comparaisons en jardin expérimental d‟ajoncs issus de populations de régions d‟origine et envahies. L‟évolution des traits d‟histoire de vie et des stratégies de défense contre les ennemis a été étudiée en lien avec la perte d‟ennemis spécialistes en zone introduite. Nos résultats suggèrent que l‟histoire évolutive dans la zone d‟origine et le mode d‟introduction volontaire par l‟Homme ont conféré un fort potentiel évolutif aux populations d‟ajonc introduites. De plus, un relâchement des corrélations génétiques dans les régions d‟introduction a pu entraîner une évolution plus libre des traits d‟histoire de vie, facilitant l‟adaptation locale à une large gamme d‟environnements. Ces résultats suggèrent que l‟étude conjointe des niches écologiques et des matrices G pourrait permettre une meilleure compréhension des processus impliqués dans les invasions biologiques.
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Shimizu, Kaya. "Host plant use in the assemblage of herbivorous insects on Macaranga myrmecophytes". Kyoto University, 2014. http://hdl.handle.net/2433/188797.
Testo completoAbstract (sommario):
Kyoto University (京都大学)0048
新制・課程博士
博士(人間・環境学)
甲第18359号
人博第672号
新制||人||162(附属図書館)
25||人博||672(吉田南総合図書館)
31217
京都大学大学院人間・環境学研究科相関環境学専攻
(主査)教授 市岡 孝朗, 教授 加藤 眞, 教授 松井 正文
学位規則第4条第1項該当
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Cloete, Andrea. "Exploring the uses and gratifications of Facebook : a psychological study". Diss., University of Pretoria, 2010. http://hdl.handle.net/2263/27560.
Testo completoAbstract (sommario):
Social networking sites such as Twitter, Facebook and My Space have experience rapid worldwide growth. It is crucial that this global phenomenon be investigated within the South African context. Social networking is a relatively new trend in South Africa and there is a paucity of academic literature on the topic. This quantitative study investigated one of the most popular social networking websites to date, namely Facebook. Facebook is a social networking website which was launched in early 2004. The primary research question focused on determining the usage patterns of South African Facebook users. In specific, the study investigated the purposes for which the site was used, the self-reported substitution of Facebook usage for face-to-face interaction and the relationship between Facebook affinity and Facebook use. A survey research design was used to collect data via an electronic questionnaire posted on Facebook. The theoretical point of departure was post-positivist. Media theories applied to the phenomenon under investigation include the uses and gratifications theory and the theory of the niche. The findings suggest that Facebook is primarily used for its intended purpose of communication. The respondents reported the gratification of versatile (multipurpose) communication. Furthermore, only half of the sample reported privacy concerns regarding Facebook. There was no significant indication that Facebook is a substitute for face-to-face interaction. Half of the sample claimed that their interpersonal contact has increased as a result of Facebook use. In addition, in accordance with expectations, the more affiliated a person is to Facebook, the more they will use Facebook. The findings of this study conform to other studies concerning social networking and provide a South African view of the global phenomenon of social networking websites.Dissertation (MA)--University of Pretoria, 2010.
Psychology
unrestricted
Libri sul tema "Interaction niche"
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Latif, Mojib. Das Ende der Ozeane: Warum wir ohne die Meere nicht überleben werden. Freiburg im Breisgau: Herder, 2014.
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Bijutsukan, Ibaraki-ken Kindai. Kōkansuru jiba-- 6-tsu no koten: 1996-nen 6-gatsu 29-nichi--7-gatsu 28-nichi = Exhibitions of six artists : interactive--individual. Mito-shi: Ibaraki-ken Kindai Bijutsukan, 1996.
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Tavares-Cromar, Annette Fatima. A study of niche overlap, species interactions and the food web of a macroinvertebrate riffle community in Duffin Creek, Ontario. Ottawa: National Library of Canada, 1990.
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Schaible, Ulrich E., e Haas Albert. Intracellular niches of microbes: A pathogens guide through the host cell. Weinheim: Wiley-VCH, 2009.
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Wolfgang, Büchs, e Gesellschaft für Ökologie (Germany). Arbeitskreis "Agrarökologie." Tagung, a cura di. Nicht bewirtschaftete Areale in der Agrarlandschaft: Ihre Funktionen und ihre Interaktionen mit landnutzungsorientierten Ökosystemen = Uncultivated areas in rural landscapes : ecological functions and interactions with agroecosytems. Berlin: Parey Buchverlag, 1999.
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Holland, John H. 7. Co-evolution and the formation of niches. Oxford University Press, 2014. http://dx.doi.org/10.1093/actrade/9780199662548.003.0007.
Testo completoAbstract (sommario):
What is a niche? ‘Co-evolution and the formation of niches’ explains that the term ‘niche’ is widely used to describe an important part of the hierarchical organization of complex adaptive systems: local use of signals and resources. Using Markov processes, a mathematical theory of niches can be formed that allows for multiple species with interaction networks that involve loops and recirculation. When realistic niches are considered, the diversity of the niche dwellers stands out. We see a complicated recirculation of resources and signals. How did this complex network of interactions evolve? The short answer is co-evolution through recombination of building blocks, often accompanied by an exaggeration of some of the resulting characteristics.
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Owen, Jennifer C., Dana M. Hawley e Kathryn P. Huyvaert, a cura di. Infectious Disease Ecology of Wild Birds. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780198746249.001.0001.
Testo completoAbstract (sommario):
Disease ecology is an interdisciplinary field that recognizes that the host–parasite interaction is shaped by the environment and can affect and be affected by the processes that occur across all levels of ecological organization. This book focuses on the dynamics of infectious diseases for wild avian hosts across different scales of biological organization—from within-host processes to landscape-level patterns. Parasite–bird interactions are both influenced by and have consequences for every level of ecological hierarchy, from the physiology, behavior, and evolution of individual hosts up to the complex biotic and abiotic interactions occurring within biological communities and ecosystems. As the most diverse group of extant vertebrates, birds have evolved to utilize every ecological niche on earth, giving them the capacity to serve as a host of pathogens in every part of the world. The diversity of birds is outmatched only by the diversity of the parasite fauna infecting them. Given the overwhelming diversity of both avian hosts and their parasites, we have only scratched the surface regarding the role that pathogens play in avian biology and the role that birds play in the maintenance and spread of zoonotic pathogens. In addition to this understudied diversity, parasite–bird interactions are increasingly occurring in rapidly changing global environments—thus, their ecology is changing—and this shapes the complex ways by which parasites influence the interconnected health of birds, humans, and shared ecosystems. The chapters in this book illustrate that the understanding of these complex and multiscale interactions requires an inherently integrative approach.
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Gow, Neil A. R., e Alistair J. P. Brown. Physiology and metabolism of fungal pathogens. A cura di Christopher C. Kibbler, Richard Barton, Neil A. R. Gow, Susan Howell, Donna M. MacCallum e Rohini J. Manuel. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780198755388.003.0003.
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The metabolism and physiology of an invading fungal pathogen determine the outcome of its interaction with the host. The pathogen must be able to assimilate nutrients to grow and colonize diverse host niches. Meanwhile, the host attempts to restrict this growth by withholding some essential nutrients, by imposing stresses, and by inducing innate immune defences. These interactions involve complex regulatory networks that ultimately dictate the equilibrium between pathogen killing and the establishment of commensal or pathogenic associations.
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Ecological Niches: Linking Classical and Contemporary Approaches (Interspecific Interactions). University Of Chicago Press, 2003.
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Ecological Niches: Linking Classical and Contemporary Approaches (Interspecific Interactions). University Of Chicago Press, 2003.
Cerca il testo completoCapitoli di libri sul tema "Interaction niche"
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Pocklington, Michael J. "Quantum Interactions as Niche-Structure". In Quantum Interaction, 335–47. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-662-45912-6_31.
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Pocklington, Michael J. "Quantum Interactions as Niche-Structure". In Quantum Interaction, 335–47. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-54943-4_31.
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Krinner, Axel, e Ingo Roeder. "Quantification and Modeling of Stem Cell–Niche Interaction". In A Systems Biology Approach to Blood, 11–36. New York, NY: Springer New York, 2014. http://dx.doi.org/10.1007/978-1-4939-2095-2_2.
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Donohue, Kathleen. "Some Evolutionary Consequences of Niche Construction with Genotype-Environment Interaction". In Adaptation and Fitness in Animal Populations, 131–49. Dordrecht: Springer Netherlands, 2009. http://dx.doi.org/10.1007/978-1-4020-9005-9_9.
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Sevic, Ina, Daiana Lujan Vitale, Fiorella Mercedes Spinelli, Matías Valenzuela Alvarez, Luciana Gutiérrez, Marcela Fabiana Bolontrade e Laura Alaniz. "The Hyaluronic Acid–CD44 Interaction in the Physio- and Pathological Stem Cell Niche". In Proteoglycans in Stem Cells, 237–62. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-73453-4_10.
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Hoshino, Junichi, Takeru Umemura, Sachi Urano e Daiki Satoi. "SONAR: Communication System for Supporting Information Gathering and Social Interaction in a Niche Market". In Advanced Information Systems Engineering, 181–88. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-662-45212-7_23.
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Castro-Muñozledo, Federico. "The Mammalian Limbal Stem Cell Niche: A Complex Interaction Between Cells, Growth Factors and Extracellular Matrix". In Stem Cell Biology and Regenerative Medicine, 23–56. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-21702-4_2.
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Estefani, Thales, Pedro Atã e João Queiroz. "How Cognitive Niche Construction Shapes Storytelling?" In Interactive Storytelling, 345–48. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-27036-4_33.
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Rees, Paul A. "Community ecology and species interactions." In Key questions in ecology: a study and revision guide, 121–39. Wallingford: CABI, 2020. http://dx.doi.org/10.1079/9781789247572.0121.
Testo completoAbstract (sommario):
Abstract This chapter contains questions about the structure of biological communities, their development over time, and the interactions between the species living within them, especially competition, niche separation and predation.
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Tang, Duozhuang. "Niche-Stem Cell Interactions and Environmental Influences". In Else Kröner-Fresenius Symposia, 87–91. Basel: S. KARGER AG, 2012. http://dx.doi.org/10.1159/000339386.
Testo completoAtti di convegni sul tema "Interaction niche"
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Guan, Xiaolan, Zhenji Zhang, Honglu Liu e Runtong Zhang. "Factor Interaction and Evaluation of the Enterprise Niche Based on Mutation". In 2008 Fourth International Conference on Natural Computation. IEEE, 2008. http://dx.doi.org/10.1109/icnc.2008.402.
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Danilina, Viktoriya A., e Kseniya S. Kardanova-Biryukova. "ACTIVITY AS A DETERMINANT OF COMMUNICATIVE BEHAVIOR OF PARTICIPANTS TO INTERNET-MEDIATED COMMUNICATION". In Люди речисты - 2021. Ulyanovsk State Pedagogical University named after I. N. Ulyanov, 2021. http://dx.doi.org/10.33065/978-5-907216-49-5-2021-359-367.
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The paper focuses on activity as the key feature of communicative behavior of participants to Internet-mediated communication. The methodological platform of the research the autopoiesis theory which allows us to model communication as the interaction between the communicant and his/her niche. The theoretical framework is supported by the experiment conducted with Russian-speaking respondents.
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Карпин, Владимир Александрович, e Ольга Ивановна Шувалова. "MECHANISMS OF BACTERIAL PERSISTENCE IN INTERACTION WITH THE MACROORGANISM". In Перспективные научные исследования: актуальные вопросы, достижения и инновации: сборник статей международной научной конференции (Санкт-Петербург, Май 2024), 101–3. Crossref, 2024. http://dx.doi.org/10.58351/240502.2024.42.99.002.
Testo completoAbstract (sommario):
Наиболее часто наблюдаемый исход инфекционного процесса имеет достаточно четкую альтернативу: процесс заканчивается либо выздоровлением организма, либо его гибелью. Но может возникать и третье состояние, когда между взаимодействующими биологическими объектами возникает «вооруженный нейтралитет», и микроб надолго поселяется в новой для него экологической нише. Феномен микробного персистирования является важнейшей проблемой современной инфектологии. В статье обсуждаются наиболее изученные механизмы выживания патогенных бактерий в организме хозяина, позволяющие уклоняться от биологической защиты. Ликвидация этих механизмов персистенции бактерий будет во многом способствовать повышению эффективности лечения больных и ликвидации бактерионосительства. The most frequently observed outcome of the infectious process has a fairly clear alternative: the process ends with either the recovery of the body or its death. But there may also be a third state, when "armed neutrality" arises between interacting biological objects, and the microbe settles for a long time in a new ecological niche for it. The phenomenon of microbial persistence is the most important problem of modern infectology. The article discusses the most studied mechanisms of survival of pathogenic bacteria in the host body, allowing them to evade biological protection. The elimination of these mechanisms of bacterial persistence will greatly contribute to improving the effectiveness of treatment of patients and the elimination of bacterial transmission.
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Hori, Yuichi, Kazuya Shimizu e Sachie Chiba. "Abstract 1501: Direct interaction between human pancreatic cancer stem cells and stromal cells remodels extracellular matrix formation for cancer stem cell niche". In Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL. American Association for Cancer Research, 2012. http://dx.doi.org/10.1158/1538-7445.am2012-1501.
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Kleine-gung, Joerg, e Elizabeth Koumpan. "Pay-per-use models, the backbone of a sharing economy: How to stimulate a sustainable human-centered ecosystem success to achieve a faster Society 5.0". In 10th International Conference on Human Interaction and Emerging Technologies (IHIET 2023). AHFE International, 2023. http://dx.doi.org/10.54941/ahfe1004069.
Testo completoAbstract (sommario):
In Society 5.0 humans aim to leverage advanced technologies to create innovative solutions for social and environmental issues. Public awareness of the need to act now to shape a liveable future for the next generations and to set the course for a climate-friendly and sustainable future has reached its peak. This societal and political pressure is currently changing and will change industries, corporate strategies, buying behaviors, and society dramatically and lastingly in the coming years. Strengthening the concept of the sharing economy is essential to achieving the sustainability goals of Society 5.0. Effective and mature implementation of pay-per-use models is the heart of the sharing economy and essential to drive that concept to the next level. Due to their cost-effectiveness, flexibility, scalability, and predictability pay-per-use models are attractive to both businesses and consumers and offer several benefits. Pay-per-use is nowadays established as the standard for payment processes of native cloud services, electric vehicles, and many others, but the full potential is not exhausted, and currently serves as a payment model rather in niche areas. We will discuss how this can be changed, and what possible implementations could look like enabled with micropayments, cryptocurrencies, and distributed ledgers. We will provide the architecture overview and explain how it fits future (should we change for the future or leave current?) banking architecture. The implementation of frictionless payment models is a significant opportunity to improve customer perception and increase revenue by providing a more convenient, secure, and efficient payment experience and is, therefore, a win for the industry, consumers, and the environment. Finally, we describe what obstacles there have been so far in implementing, and what a roadmap to strengthen pay-per-use models and sharing economies might look like.
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Zhartun, E. S., e D. B. Nizheharodava. "EXTRACELLULAR VESICLES AS A MECHANISM OF INTERCELLULAR COMMUNICATION IN TUMOR PATHOPHYSIOLOGY". In SAKHAROV READINGS 2022: ENVIRONMENTAL PROBLEMS OF THE XXI CENTURY. International Sakharov Environmental Institute of Belarusian State University, 2022. http://dx.doi.org/10.46646/sakh-2022-2-125-128.
Testo completoAbstract (sommario):
In normal cells, mechanisms that prevent the development of cancer function, while in tumor cells there are defects in the regulatory chain that controls cell proliferation and its homeostasis. Intercellular communication is the exchange of information through various signaling mechanisms affecting many aspects of cell life and is crucial for morphogenesis, differentiation, interaction, homeostasis and cell growth. The study of the mechanisms of intercellular communication mediated by extracellular vesicles is important for understanding the sequential events in the cell that lead to the development of cancer. The key importance of intercellular communication of tumor cells is manifested in autocrine stimulation (increased proliferation and inhibition of apoptosis signals), suppression of immunity (tumor extracellular vesicles create an immunosuppressive environment), preparation of a metastatic niche.
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Ercegovac, Ivana, Mirjana Tankosić e Andrea Vlahović. "From Content Creators to Business Innovators: The Entrepreneurial Impact of YouTube Influencer Channels". In 9th International Scientific Conference ERAZ - Knowledge Based Sustainable Development. Association of Economists and Managers of the Balkans, Belgrade, Serbia, 2023. http://dx.doi.org/10.31410/eraz.s.p.2023.187.
Testo completoAbstract (sommario):
Social media’s transformative impact has led YouTube influencers to assume roles as content creators and entrepreneurs. This study delves into their innovative strategies encompassing revenue models, brand collaborations, and audience engagement. Ad revenue, sponsorships, subscriptions, merchandise sales, and crowdfunding form the diverse income streams. Affiliate marketing and product placements foster new business avenues. Niche content and data insights elevate audience interaction. Supported by platforms like Patreon, varied revenue channels drive sustainable financial growth. Collaboration strategies, such as endorsements, invigorate the digital economy. Entrepreneurial impact resonates through job creation, small business support, and innovation. Ethical considerations ensure sustainable growth. This study guides aspiring entrepreneurs and marketers by accentuating diverse revenue streams, strategic partnerships, and audience engagement. Future exploration may assess the endurance of influencer entrepreneurship, its effects on traditional media, and emerging platforms’ nurturing of entrepreneurial endeavors.
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Li, Yanheng, Lin Luoying, Xinyan Li, Yaxuan Mao e Ray LC. ""Nice to meet you!"". In HRI '23: ACM/IEEE International Conference on Human-Robot Interaction. New York, NY, USA: ACM, 2023. http://dx.doi.org/10.1145/3568294.3580045.
Testo completo
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Sanz, W., Carl-W. Hustad e H. Jericha. "First Generation Graz Cycle Power Plant for Near-Term Deployment". In ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/gt2011-45135.
Testo completoAbstract (sommario):
Carbon Capture and Storage (CCS) is a recognized technology pathway to curb the increasing emissions of carbon dioxide (CO2) from the power generation sector. But most available technologies are still on the study or laboratory-scale level, so that considerable R&D efforts are needed to achieve commercialization level. The Graz Cycle originally presented in 1995 by Jericha [1] is an oxyfuel technology and promises highest efficiency using state-of-the-art turbine materials and improved thermodynamic developments in a comparatively complex interaction of rotating machinery, condensers and heat exchanger components. But although detailed conceptual design for all main components has been presented, there is still a large step towards a Graz Cycle pilot demonstration plant. In order to facilitate construction of a demonstration plant we consider the performance of a near-term Graz Cycle process design based on modest cycle data and available turbomachinery components using a simplified flow scheme. The work is supported by on-going development work for a first generation oxyfuel turbine that has already been undertaken by Clean Energy Systems, Inc. [2]. Their further work on a second generation oxyfuel turbine received $30 million funding support from the U.S. Department of Energy in September 2010 [3]. Two near-term Graz Cycle plants are presented based on basic and advanced operating conditions of the proposed commercially available turbine. Besides the turbine the additional equipment for a first-generation cycle is discussed. The predicted optimum net efficiency is 23.2% (HHV). A near-term zero-emission power plant can only be commercially attractive if it will be deployed in a niche market. Therefore an economic analysis commensurate with an early pre-FEED conceptual study is carried out for the U.S. Gulf Coast where revenue from multiple product streams that could include power, steam, CO2 and water, as well as argon and (potentially) nitrogen from the ASU is provided. The economic analysis suggests that a capital investment of $94 million can secure construction of a 13.2 MWe zero emission oxyfuel power plant and yield a 14.5% (unlevered) return on capital invested.
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Gibson, Andrew, e Roberto Martinez-Maldonado. "That dashboard looks nice, but what does it mean?" In OzCHI '17: 29th Australian Conference on Human-Computer Interaction. New York, NY, USA: ACM, 2017. http://dx.doi.org/10.1145/3152771.3156171.
Testo completoRapporti di organizzazioni sul tema "Interaction niche"
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Piza, Caio, Tulio Cravo, Simon Lodato e Jose Claudio Linhares Pires. Evaluation of the Opportunities for the Majority Initiative. Inter-American Development Bank, giugno 2012. http://dx.doi.org/10.18235/0010433.
Testo completoAbstract (sommario):
The Opportunities for the Majority Initiative (OMJ) was originally set up for three years as a time-bound pilot initiative. The OMJ team has worked diligently to test the Base of the Pyramid model and develop the OMJ portfolio, and from that standpoint the initiative has been successful. Regarding OMJ's operational objectives, its achievements on targeting, innovation, learning, and replication have been mixed. OMJ has not found a unique market niche that cannot be served by another IDB Group private sector window with significant operational advantages over OMJ. In light of the findings, the IDB should strengthen OMJ's operations; improve the evaluability, monitoring and evaluation of projects; and adapt risk management, pricing, and legal procedures to facilitate interactions with lower-income clients. The IDB should consider options for consolidating OMJ activities and those of other IDB Group private sector windows.
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Shpigel, Nahum Y., Ynte Schukken e Ilan Rosenshine. Identification of genes involved in virulence of Escherichia coli mastitis by signature tagged mutagenesis. United States Department of Agriculture, gennaio 2014. http://dx.doi.org/10.32747/2014.7699853.bard.
Testo completoAbstract (sommario):
Mastitis, an inflammatory response of the mammary tissue to invading pathogenic bacteria, is the largest health problem in the dairy industry and is responsible for multibillion dollar economic losses. E. coli are a leading cause of acute mastitis in dairy animals worldwide and certainly in Israel and North America. The species E. coli comprises a highly heterogeneous group of pathogens, some of which are commensal residents of the gut, infecting the mammary gland after contamination of the teat skin from the environment. As compared to other gut microflora, mammary pathogenic E. coli (MPEC) may have undergone evolutionary adaptations that improve their fitness for colonization of the unique and varied environmental niches found within the mammary gland. These niches include competing microbes already present or accompanying the new colonizer, soluble and cellular antimicrobials in milk, and the innate immune response elicited by mammary cells and recruited immune cells. However, to date, no specific virulence factors have been identified in E. coli isolates associated with mastitis. The original overall research objective of this application was to develop a genome-wide, transposon-tagged mutant collection of MPEC strain P4 and to use this technology to identify E. coli genes that are specifically involved in mammary virulence and pathogenicity. In the course of the project we decided to take an alternative genome-wide approach and to use whole genomes bioinformatics analysis. Using genome sequencing and analysis of six MPEC strains, our studies have shown that type VI secretion system (T6SS) gene clusters were present in all these strains. Furthermore, using unbiased screening of MPEC strains for reduced colonization, fitness and virulence in the murine mastitis model, we have identified in MPEC P4-NR a new pathogenicity island (PAI-1) encoding the core components of T6SS and its hallmark effectors Hcp, VgrG and Rhs. Next, we have shown that specific deletions of T6SS genes reduced colonization, fitness and virulence in lactating mouse mammary glands. Our long-term goal is to understand the molecular mechanisms of host-pathogen interactions in the mammary gland and to relate these mechanisms to disease processes and pathogenesis. We have been able to achieve our research objectives to identify E. coli genes that are specifically involved in mammary virulence and pathogenicity. The project elucidated a new basic concept in host pathogen interaction of MPEC, which for the best of our knowledge was never described or investigated before. This research will help us to shed new light on principles behind the infection strategy of MPEC. The new targets now enable prevalence and epidemiology studies of T6SS in field strains of MPEC which might unveil new geographic, management and ecological risk factors. These will contribute to development of new approaches to treat and prevent mastitis by MPEC and perhaps other mammary pathogens. The use of antibiotics in farm animals and specifically to treat mastitis is gradually precluded and thus new treatment and prevention strategies are needed. Effective mastitis vaccines are currently not available, structural components and effectors of T6SS might be new targets for the development of novel vaccines and therapeutics.
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Salavisa, Isabel, Mark Soares e Sofia Bizarro. A Critical Assessment of Organic Agriculture in Portugal: A reflection on the agro-food system transition. DINÂMIA'CET-Iscte, 2021. http://dx.doi.org/10.15847/dinamiacet-iul.wp.2021.05.
Testo completoAbstract (sommario):
Over the last few decades, the organic agriculture sector has experienced sustained growth. Globally, as well as in the European Union and Portugal, organic production accounts for just under 10% of total Utilised Agricultural Area (UAA) (FiBL, 2019; Eurostat, 2019; DGADR, 2019; INE, 2019; GPP, 2019). This growth has been seen in terms of production, number of producers, amount of retail sales, imports and exports. This article attempts to build on the multi-level perspective (MLP) of the socio-technical (ST) transitions theory by employing a whole systems analysis (Geels, 2018) of organic agriculture in Portugal, which defends an integrated vision of the systems, where multiple interactions occur within and among the niche, the regime and the landscape levels. This approach has been employed in order to develop a critical analysis of the current state of the Portuguese organic agriculture sector, stressing the multiplicity of elements that are contributing to the agro-food system´s transformation into a more sustainable one. In fact, the agro-food system is related with climate change but also has connections with other domains such as public health, water management, land use and biodiversity. Therefore, it is affected by shifts in these areas. This analysis considers developments in increasing domestic organic production, number of producers, amount of retail sales, imports, exports, market innovations, and the sector´s reconfiguration. The organic sector´s increase has been attributed to European regulation, institutionalization, standardization, farmer certification, external (government) subsidy support programs, incremental market improvements (visibility and product access), the emergence of new retailers, the rise of supporting consumers and a shift away from conventional agriculture (Truninger, 2010; DGADR, 2019; Pe´er et al, 2019). However, together with positive incentives, this sector also faces numerous barriers that are hindering a faster transformation. Difficulties for the sector to date have included: product placement; a disconnect between production, distribution and marketing systems; high transport costs; competition from imports; European subsidies focused on extensive crops (pastures, olive groves, and arable crops), entailing a substantial growth in the area of pasture to the detriment of other crops; the fact that the products that are in demand (fresh vegetables and fruit) are being neglected by Portuguese producers; expensive certification procedures; lack of adequate support and market expertise for national producers; the hybrid configuration of the sector; and price. Organic agriculture as a niche-innovation is still not greatly contributing to overall agricultural production. The low supply of organic products, despite its ever-increasing demand, suggests that a transition to increased organic production requires a deeper and faster food system reconfiguration, where an array of distinct policies are mobilized and a diversity of actions take place at different levels (Geels, 2018; Pe´er et al, 2019). This paper will attempt to contribute an overall critical assessment of the organic sector´s features and evolution and will identify some of the main obstacles to be overcome, in order to boost the sustainability transition of the agro-food system in Portugal.
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Vaskivskyj, Yurij. STATE AND PROSPECTS OF THE DEVELOPMENT OF RUSSIAN-UKRAINIAN WAR: PERSONNEL ASPECT. Ivan Franko National University of Lviv, marzo 2024. http://dx.doi.org/10.30970/vjo.2024.54-55.12144.
Testo completoAbstract (sommario):
The article analyzes the state of development of Ukrainian advertising in the conditions of the Russian-Ukrainian war. Studying the work of Ukrainian advertising agencies during the war is a unique experience of Ukrainian specialists during the war. The article emphasizes that Ukrainian advertising agencies have become an example for global corporations with their resilience and courage. The study of the place of Ukrainian advertising agencies in the world system made it possible to state that the domestic industry is developing in step with the world one. This was facilitated by the fact that Ukrainians quickly adapt to modern technologies and catch global trends. In some areas of advertising, Ukrainian agencies are one step ahead of European and American ones. Communication with Ukrainian heads of advertising campaigns, marketers and target specialists, who were directly involved in the “rescue” of companies at the beginning of the war, made it possible to find out how the business development strategy changed, what tactical solutions they used at the beginning of the war, and how they optimized the work of the team. The results of the research give grounds for asserting that in the conditions of the Russian-Ukrainian war, many brands have developed new rules for content and communication in social networks. The content strategy of brands needs maximum adaptation to new realities. The traditional division of content into branded, selling, fan and interactive content is losing its relevance. This market niche is occupied by social, supportive and useful content. In particular, as an example of social brand content, we can name: the national position of an advertising agency, support of the Armed Forces of Ukraine, assistance to consumers, new adapted services, HR information about agency support, assistance to temporarily displaced persons, volunteering. Ukrainian advertising agencies were able to quickly adapt to the conditions of the war, entered international markets, took care of their employees and continue their work. Keywords: advertising, agencies, Russian-Ukrainian war, social networks, work with clients, personnel problems.
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Aleksandrov, Pavlo. NEWS GAMES IN THE UKRAINIAN MEDIA SPACE DURING THE FULL-SCALE RUSSIAN INVASION. Ivan Franko National University of Lviv, marzo 2024. http://dx.doi.org/10.30970/vjo.2024.54-55.12140.
Testo completoAbstract (sommario):
The phenomenon of news games on the topic of the Russian-Ukrainian war of 2022-2023 has been explored in the article. During the research, a number of gaming projects from this period were analyzed, their genre and thematic specificity were determined, examples of gaming products were provided, and our own concept of a news game on the topical subject of wartime was presented. In 2022-2023, many game projects on the theme of the war in Ukraine appeared, which can be fully or partially classified as news games, conditionally dividing them into “civilian” ones, where the game character is a volunteer, an immigrant, a peaceful resident of the occupied territory, etc. and “combat”, in which the character is a Ukrainian soldier or combat unit. These games are primarily developed by gaming studios or individual game developers, rather than journalistic editorial teams, and they target an international audience (almost all the analyzed games have an English version). We categorize these news games as “entertainment” (those primarily oriented towards humor, boosting morale, and using current information or media images) and “serious” (those attempting to explain, reveal the essence, and show the war through the eyes of witnesses). According to the level of technical implementation, these games can be divided into “simple” ones (browser-based, requiring no download or payment) and “complex” ones that offer extended gameplay and are available only through subscription. Almost all gaming projects encourage donations to the Armed Forces of Ukraine and charitable funds, and the authors of paid games always emphasize that a portion of the proceeds will go towards supporting Ukrainian military personnel. Despite their significant potential, news games currently occupy a small niche in the Ukrainian media landscape. At the same time, in our opinion, the creative possibilities offered by the gaming mechanism of this interactive narrative are quite promising for explaining and revealing various socially important topics related to the Russian-Ukrainian war. Keywords: gamification; news games; game format; game research.
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Prusky, Dov, e Jeffrey Rollins. Modulation of pathogenicity of postharvest pathogens by environmental pH. United States Department of Agriculture, dicembre 2006. http://dx.doi.org/10.32747/2006.7587237.bard.
Testo completoAbstract (sommario):
Until recently, environmental pH was not considered a factor in determining pathogen compatibility. Our hypothesis was that the environmental pH at the infection site, which is dynamically controlled by activities of both the host and the pathogen, regulates the expression of genes necessary for disease development in Colletotrichum gloeosporioides and Sclerotinia sclerotiorum. This form of regulation ensures that genes are expressed at optimal conditions for their encoded activities.Pectate lyase encoded by pelB, has been demonstrated to play a key role in virulence of C. gloeosporioides in avocado fruit. Polyglacturonase synergism with oxalic acid production is considered to be an essential pathogenicity determinant in the interactions of S. sclerotiorum with its numerous hosts. A common regulatory feature of these virulence and pathogenicity factors is their dependence upon environmental pH conditions within the host niche to create optimal conditions for expression and secretion. In this proposal we have examined, 1) the mechanisms employed by these fungi to establish a suitable pH environment, 2) the molecular levels at which genes and gene products are regulated in response to environmental pH, and 3) the molecular basis and functional importance of pH-responsive gene regulation during pathogenicity. The specific objectives of the proposal were: 1. Characterize the mechanism of local pH modulation and the effect of ambient pH on the expression and secretion of virulence factors. 2. Provide evidence that a conserved molecular pathway for pH-responsive gene expression exists in C. gloeosporioides by cloning a pacC gene homologue. 3. Determine the role of pacC in pathogenicity by gene disruption and activating mutations. Major conclusions 1. We determined the importance of nitrogen source and external pH in the secretion of the virulence factor pectate lyase with respect to the ambient pH transcriptional regulator pacC. It was concluded that nitrogen source availability and ambient pH are two independent signals for the transcriptional regulation of genes required for the disease process of C. gloeosporioides and possibly of other pathogens. 2. We also determined that availability of ammonia regulate independently the alkalinization process and pelB expression, pecate lyase secretion and virulence of C. gloeosporioides. 3. Gene disruption of pacC reduced virulence of C. gloeosporioides however did not reduced fully pelB expression. It was concluded that pelB expression is regulated by several factors including pH, nitrogen and carbon sources. 4. Gene disruption of pacC reduced virulence of S. slcerotiourum Creation of a dominant activating
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Or, Dani, Shmulik Friedman e Jeanette Norton. Physical processes affecting microbial habitats and activity in unsaturated agricultural soils. United States Department of Agriculture, ottobre 2002. http://dx.doi.org/10.32747/2002.7587239.bard.
Testo completoAbstract (sommario):
experimental methods for quantifying effects of water content and other dynamic environmental factors on bacterial growth in partially-saturated soils. Towards this end we reviewed critically the relevant scientific literature and performed theoretical and experimental studies of bacterial growth and activity in modeled, idealized and real unsaturated soils. The natural wetting-drying cycles common to agricultural soils affect water content and liquid organization resulting in fragmentation of aquatic habitats and limit hydraulic connections. Consequently, substrate diffusion pathways to soil microbial communities become limiting and reduce nutrient fluxes, microbial growth, and mobility. Key elements that govern the extent and manifestation of such ubiquitous interactions include characteristics of diffusion pathways and pore space, the timing, duration, and extent of environmental perturbations, the nature of microbiological adjustments (short-term and longterm), and spatial distribution and properties of EPS clusters (microcolonies). Of these key elements we have chosen to focus on a manageable subset namely on modeling microbial growth and coexistence on simple rough surfaces, and experiments on bacterial growth in variably saturated sand samples and columns. Our extensive review paper providing a definitive “snap-shot” of present scientific understanding of microbial behavior in unsaturated soils revealed a lack of modeling tools that are essential for enhanced predictability of microbial processes in soils. We therefore embarked on two pronged approach of development of simple microbial growth models based on diffusion-reaction principles to incorporate key controls for microbial activity in soils such as diffusion coefficients and temporal variations in soil water content (and related substrate diffusion rates), and development of new methodologies in support of experiments on microbial growth in simple and observable porous media under controlled water status conditions. Experimental efforts led to a series of microbial growth experiments in granular media under variable saturation and ambient conditions, and introduction of atomic force microscopy (AFM) and confocal scanning laser microscopy (CSLM) to study cell size, morphology and multi-cell arrangement at a high resolution from growth experiments in various porous media. The modeling efforts elucidated important links between unsaturated conditions and microbial coexistence which is believed to support the unparallel diversity found in soils. We examined the role of spatial and temporal variation in hydration conditions (such as exist in agricultural soils) on local growth rates and on interactions between two competing microbial species. Interestingly, the complexity of soil spaces and aquatic niches are necessary for supporting a rich microbial diversity and the wide array of microbial functions in unsaturated soils. This project supported collaboration between soil physicists and soil microbiologist that is absolutely essential for making progress in both disciplines. It provided a few basic tools (models, parameterization) for guiding future experiments and for gathering key information necessary for prediction of biological processes in agricultural soils. The project sparked a series of ongoing studies (at DTU and EPFL and in the ARO) into effects of soil hydration dynamics on microbial survival strategy under short term and prolonged desiccation (important for general scientific and agricultural applications).