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Готові списки джерел за темами / Extinction methods

Добірка наукової літератури з теми "Extinction methods"

Автор: Grafiati

Опубліковано: 7 липня 2024

Оновлено: 7 липня 2024

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Статті в журналах з теми "Extinction methods":

1

Bromham, Lindell, Robert Lanfear, Phillip Cassey, Gillian Gibb, and Marcel Cardillo. "Reconstructing past species assemblages reveals the changing patterns and drivers of extinction through time." Proceedings of the Royal Society B: Biological Sciences 279, no. 1744 (August 2012): 4024–32. http://dx.doi.org/10.1098/rspb.2012.1437.

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Predicting future species extinctions from patterns of past extinctions or current threat status relies on the assumption that the taxonomic and biological selectivity of extinction is consistent through time. If the driving forces of extinction change through time, this assumption may be unrealistic. Testing the consistency of extinction patterns between the past and the present has been difficult, because the phylogenetically explicit methods used to model present-day extinction risk typically cannot be applied to the data from the fossil record. However, the detailed historical and fossil records of the New Zealand avifauna provide a unique opportunity to reconstruct a complete, large faunal assemblage for different periods in the past. Using the first complete phylogeny of all known native New Zealand bird species, both extant and extinct, we show how the taxonomic and phylogenetic selectivity of extinction, and biological correlates of extinction, change from the pre-human period through Polynesian and European occupation, to the present. These changes can be explained both by changes in primary threatening processes, and by the operation of extinction filter effects. The variable patterns of extinction through time may confound attempts to identify risk factors that apply across time periods, and to infer future species declines from past extinction patterns and current threat status.

2

Geyle, Hayley M., John C. Z. Woinarski, G. Barry Baker, Chris R. Dickman, Guy Dutson, Diana O. Fisher, Hugh Ford, et al. "Quantifying extinction risk and forecasting the number of impending Australian bird and mammal extinctions." Pacific Conservation Biology 24, no. 2 (2018): 157. http://dx.doi.org/10.1071/pc18006.

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A critical step towards reducing the incidence of extinction is to identify and rank the species at highest risk, while implementing protective measures to reduce the risk of extinction to such species. Existing global processes provide a graded categorisation of extinction risk. Here we seek to extend and complement those processes to focus more narrowly on the likelihood of extinction of the most imperilled Australian birds and mammals. We considered an extension of existing IUCN and NatureServe criteria, and used expert elicitation to rank the extinction risk to the most imperilled species, assuming current management. On the basis of these assessments, and using two additional approaches, we estimated the number of extinctions likely to occur in the next 20 years. The estimates of extinction risk derived from our tighter IUCN categorisations, NatureServe assessments and expert elicitation were poorly correlated, with little agreement among methods for which species were most in danger – highlighting the importance of integrating multiple approaches when considering extinction risk. Mapped distributions of the 20 most imperilled birds reveal that most are endemic to islands or occur in southern Australia. The 20 most imperilled mammals occur mostly in northern and central Australia. While there were some differences in the forecasted number of extinctions in the next 20 years among methods, all three approaches predict further species loss. Overall, we estimate that another seven Australian mammals and 10 Australian birds will be extinct by 2038 unless management improves.

3

Lombardi, Marco. "Optimal extinction measurements." Astronomy & Astrophysics 615 (July 2018): A174. http://dx.doi.org/10.1051/0004-6361/201832769.

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In this paper we present XNICER, an optimized multi-band extinction technique based on the extreme deconvolution of the intrinsic colors of objects observed through a molecular cloud. XNICER follows a rigorous statistical approach and provides the full Bayesian inference of the extinction for each observed object. Photometric errors in both the training control field and in the science field are properly taken into account. XNICER improves over the known extinction methods and is computationally fast enough to be used on large datasets of objects. Our tests and simulations show that this method is able to reduce the noise associated with extinction measurements by a factor 2 with respect to the previous NICER algorithm, and it has no evident bias even at high extinctions.

4

Nawrot, Rafał, Daniele Scarponi, Michele Azzarone, Troy A. Dexter, Kristopher M. Kusnerik, Jacalyn M. Wittmer, Alessandro Amorosi, and Michał Kowalewski. "Stratigraphic signatures of mass extinctions: ecological and sedimentary determinants." Proceedings of the Royal Society B: Biological Sciences 285, no. 1886 (September 12, 2018): 20181191. http://dx.doi.org/10.1098/rspb.2018.1191.

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Stratigraphic patterns of last occurrences (LOs) of fossil taxa potentially fingerprint mass extinctions and delineate rates and geometries of those events. Although empirical studies of mass extinctions recognize that random sampling causes LOs to occur earlier than the time of extinction (Signor–Lipps effect), sequence stratigraphic controls on the position of LOs are rarely considered. By tracing stratigraphic ranges of extant mollusc species preserved in the Holocene succession of the Po coastal plain (Italy), we demonstrated that, if mass extinction took place today, complex but entirely false extinction patterns would be recorded regionally due to shifts in local community composition and non-random variation in the abundance of skeletal remains, both controlled by relative sea-level changes. Consequently, rather than following an apparent gradual pattern expected from the Signor–Lipps effect, LOs concentrated within intervals of stratigraphic condensation and strong facies shifts mimicking sudden extinction pulses. Methods assuming uniform recovery potential of fossils falsely supported stepwise extinction patterns among studied species and systematically underestimated their stratigraphic ranges. Such effects of stratigraphic architecture, co-produced by ecological, sedimentary and taphonomic processes, can easily confound interpretations of the timing, duration and selectivity of mass extinction events. Our results highlight the necessity of accounting for palaeoenvironmental and sequence stratigraphic context when inferring extinction dynamics from the fossil record.

5

Smith, Woollcott K., and Andrew R. Solow. "Missing and presumed lost: extinction in the ocean and its inference." ICES Journal of Marine Science 69, no. 1 (November 13, 2011): 89–94. http://dx.doi.org/10.1093/icesjms/fsr176.

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Abstract Smith, W. K., and Solow, A. R. 2012. Missing and presumed lost: extinction in the ocean and its inference. – ICES Journal of Marine Science, 69: 89–94. The number of modern extinctions in the ocean is unknown. The actual demise of the last individual of a species is essentially unobservable, so extinction can only be inferred. Statistical methods are described for inferring extinction from sighting records, species–area considerations, and taxonomic samples collected at two different times. The methods are illustrated using a variety of real datasets, including a sighting record of the Caribbean monk seal and results from three surveys of benthic invertebrates.

6

Burgman, M. A. "Evaluating methods for assessing extinction risk." Acta Oecologica 26, no. 2 (October 2004): 65–66. http://dx.doi.org/10.1016/j.actao.2004.06.001.

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7

Dai, Xu, and Haijun Song. "Toward an understanding of cosmopolitanism in deep time: a case study of ammonoids from the middle Permian to the Middle Triassic." Paleobiology 46, no. 4 (September 21, 2020): 533–49. http://dx.doi.org/10.1017/pab.2020.40.

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AbstractCosmopolitanism occurred recurrently during the geologic past, especially after mass extinctions, but the underlying mechanisms remain poorly known. Three theoretical models, not mutually exclusive, can lead to cosmopolitanism: (1) selective extinction in endemic taxa, (2) endemic taxa becoming cosmopolitan after the extinction and (3) an increase in the number of newly originated cosmopolitan taxa after extinction. We analyzed an updated occurrence dataset including 831 middle Permian to Middle Triassic ammonoid genera and used two network methods to distinguish major episodes of ammonoid cosmopolitanism during this time interval. Then, we tested the three proposed models in these case studies. Our results confirm that at least two remarkable cosmopolitanism events occurred after the Permian–Triassic and late Smithian (Early Triassic) extinctions, respectively. Partitioned analyses of survivors and newcomers revealed that the immediate cosmopolitanism event (Griesbachian) after the Permian–Triassic event can be attributed to endemic genera becoming cosmopolitan (model 2) and an increase in the number of newly originated cosmopolitan genera after the extinction (model 3). Late Smithian cosmopolitanism is caused by selective extinction in endemic taxa (model 1) and an increase in the number of newly originated cosmopolitan genera (model 3). We found that the survivors of the Permian–Triassic mass extinction did not show a wider geographic range, suggesting that this mass extinction is nonselective among the biogeographic ranges, while late Smithian survivors exhibit a wide geographic range, indicating selective survivorship among cosmopolitan genera. These successive cosmopolitanism events during severe extinctions are associated with marked environmental upheavals such as rapid climate changes and oceanic anoxic events, suggesting that environmental fluctuations play a significant role in cosmopolitanism.

8

Nogueras-Lara, F., R. Schödel, N. Neumayer, E. Gallego-Cano, B. Shahzamanian, A. T. Gallego-Calvente, and F. Najarro. "GALACTICNUCLEUS: A high angular-resolution JHKs imaging survey of the Galactic centre." Astronomy & Astrophysics 641 (September 2020): A141. http://dx.doi.org/10.1051/0004-6361/202038606.

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Context. The characterisation of the extinction curve in the near-infrared (NIR) is fundamental to analysing the structure and stellar population of the Galactic centre (GC), whose analysis is hampered by the extreme interstellar extinction (AV ~ 30 mag) that varies on arc-second scales. Recent studies indicate that the behaviour of the extinction curve might be more complex than previously assumed, pointing towards a variation of the extinction curve as a function of wavelength. Aims. We aim to analyse the variations of the extinction index, α, with wavelength, line-of-sight, and absolute extinction, extending previous analyses to a larger area of the innermost regions of the Galaxy. Methods. We analysed the whole GALACTICNUCLEUS survey, a high-angular resolution (~0.2″) JHKs NIR survey specially designed to observe the GC in unprecedented detail. It covers a region of ~6000 pc2, comprising fields in the nuclear stellar disc, the inner bulge, and the transition region between them. We applied two independent methods based on red clump (RC) stars to constrain the extinction curve and analysed its variation superseding previous studies. Results. We used more than 165 000 RC stars and increased the size of the regions analysed significantly to confirm that the extinction curve varies with the wavelength. We estimated a difference Δα = 0.21 ± 0.07 between the obtained extinction indices, αJH = 2.44 ± 0.05 and αHKs = 2.23 ± 0.05. We also concluded that there is no significant variation of the extinction curve with wavelength, with the line-of-sight or the absolute extinction. Finally, we computed the ratios between extinctions, AJ∕AH = 1.87 ± 0.03 and AH/AKs = 1.84 ± 0.03, consistent with all the regions of the GALACTICNUCLEUS catalogue.

9

Ausich, William I., Thomas W. Kammer, and Tomasz K. Baumiller. "Demise of the middle Paleozoic crinoid fauna: a single extinction event or rapid faunal turnover?" Paleobiology 20, no. 3 (1994): 345–61. http://dx.doi.org/10.1017/s0094837300012811.

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Macroevolutionary change from the Middle to the Late Paleozoic crinoid fauna was not the result of mass extinction. The presumption that the decline of the middle Paleozoic crinoid fauna was from a single mass extinction event was tested using seriation, multidimensional scaling (MDS), binomial analysis, and bootstrapping simulations on a data set which is a comprehensive revision of old faunal lists. The data for these analyses were based on temporal distributions of 214 species from 69 late Osagean and early Meramecian localities from the midcontinental United States. The time under consideration is subdivided into seven informal intervals using MDS in conjunction with biostratigraphy. Seriation of species ranges into these intervals results in a gradual pattern of faunal turnover, and sampling bias can be eliminated as a cause for this more gradual pattern. MDS analysis of the crinoid range data is similar to MDS simulations using data with continuous, monotonic species turnover and dissimilar to a simulated mass extinction. Binomial analysis and bootstrapping demonstrate that the observed number of extinctions at the putative extinction boundary were not unusually high. All methods agree that extinctions throughout this time were high but spanned several time intervals and that rapid, monotonic faunal turnover describes the data better than mass extinction. Macroevolutionary processes other than mass extinction and microevolutionary processes must have dictated the character and composition of this remarkable faunal transition among the Crinoidea.

10

Viglietti, Pia A., Roger B. J. Benson, Roger M. H. Smith, Jennifer Botha, Christian F. Kammerer, Zaituna Skosan, Elize Butler, et al. "Evidence from South Africa for a protracted end-Permian extinction on land." Proceedings of the National Academy of Sciences 118, no. 17 (April 19, 2021): e2017045118. http://dx.doi.org/10.1073/pnas.2017045118.

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Earth’s largest biotic crisis occurred during the Permo–Triassic Transition (PTT). On land, this event witnessed a turnover from synapsid- to archosauromorph-dominated assemblages and a restructuring of terrestrial ecosystems. However, understanding extinction patterns has been limited by a lack of high-precision fossil occurrence data to resolve events on submillion-year timescales. We analyzed a unique database of 588 fossil tetrapod specimens from South Africa’s Karoo Basin, spanning ∼4 My, and 13 stratigraphic bin intervals averaging 300,000 y each. Using sample-standardized methods, we characterized faunal assemblage dynamics during the PTT. High regional extinction rates occurred through a protracted interval of ∼1 Ma, initially co-occurring with low origination rates. This resulted in declining diversity up to the acme of extinction near the Daptocephalus–Lystrosaurus declivis Assemblage Zone boundary. Regional origination rates increased abruptly above this boundary, co-occurring with high extinction rates to drive rapid turnover and an assemblage of short-lived species symptomatic of ecosystem instability. The “disaster taxon” Lystrosaurus shows a long-term trend of increasing abundance initiated in the latest Permian. Lystrosaurus comprised 54% of all specimens by the onset of mass extinction and 70% in the extinction aftermath. This early Lystrosaurus abundance suggests its expansion was facilitated by environmental changes rather than by ecological opportunity following the extinctions of other species as commonly assumed for disaster taxa. Our findings conservatively place the Karoo extinction interval closer in time, but not coeval with, the more rapid marine event and reveal key differences between the PTT extinctions on land and in the oceans.

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Дисертації з теми "Extinction methods":

1

Faller, Beáta. "Combinatorial and probabilistic methods in biodiversity theory." Thesis, University of Canterbury. Mathematics and Statistics, 2010. http://hdl.handle.net/10092/3985.

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Phylogenetic diversity (PD) is a measure of species biodiversity quantified by how much of an evolutionary tree is spanned by a subset of species. In this thesis, we study optimization problems that aim to find species sets with maximum PD in different scenarios, and examine random extinction models under various assumptions to predict the PD of species that will still be present in the future. Optimizing PD with Dependencies is a combinatorial optimization problem in which species form an ecological network. Here, we are interested in selecting species sets of a given size that are ecologically viable and that maximize PD. The NP-hardness of this problem is proved and it is established which special cases of the problem are computationally easy and which are computationally hard. It is also shown that it is NP-complete to decide whether the feasible solution obtained by the greedy algorithm is optimal. We formulate the optimization problem as an integer linear program and find exact solutions to the largest food web currently in the empirical literature. In addition, we give a generalization of PD that can be used for example when we do not know the true evolutionary history. Based on this measure, an optimization problem is formulated. We discuss the complexity and the approximability properties of this problem. In the generalized field of bullets model (g-FOB), species are assumed to become extinct with possibly different probabilities, and extinction events are independent. We show that under this model the distribution of future phylogenetic diversity converges to a normal distribution as the number of species grows. When extinction probabilities are influenced by some binary character on the tree, the state-based field of bullets model (s-FOB) represents a more realistic picture. We compare the expected loss of PD under this model to that under the associated g-FOB model and find that the former is always greater than or equal to the latter. It is natural to further generalize the s-FOB model to allow more than one binary character to affect the extinction probabilities. The expected future PD obtained for the resulting trait-dependent field of bullets model (t-FOB) is compared to that for the associated g-FOB model and our previous result is generalized.

2

Li, Linlin, Shiyin Shen, Jinliang Hou, Fangting Yuan, Jing Zhong, Hu Zou, Xu Zhou, et al. "GALACTIC EXTINCTION AND REDDENING FROM THE SOUTH GALACTIC CAP u -BAND SKY SURVEY: u -BAND GALAXY NUMBER COUNTS AND u − r COLOR DISTRIBUTION." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/623264.

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We study the integral Galactic extinction and reddening based on the galaxy catalog of the South Galactic Cap u-band Sky Survey (SCUSS), where u-band galaxy number counts and u - r color distribution are used to derive the Galactic extinction and reddening respectively. We compare these independent statistical measurements with the reddening map of Schlegel et al. (SFD) and find that both the extinction and reddening from the number counts and color distribution are in good agreement with the SFD results at low extinction regions (E(B - V)(SFD) < 0.12 mag). However, for high extinction regions (E(B - V)(SFD) > 0.12 mag), the SFD map overestimates the Galactic reddening systematically, which can be approximated by a linear relation Delta E(B - V)= 0.43[ E(B - V)(SFD) - 0.12]. By combining the results from galaxy number counts and color distribution, we find that the shape of the Galactic extinction curve is in good agreement with the standard R-V = 3.1 extinction law of O'Donnell.

3

Cole, Selina R. "Phylogeny, Diversification, and Extinction Selectivity in Camerate Crinoids." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1492594839778373.

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4

Corey, Sarah J. "Understanding Amphibian Vulnerability to Extinction: A Phylogenetic and Spatial Approach." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1244036842.

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5

Rådahl, Elmer. "Extinction in the solar neighborhood : A comparative study of two methods used to measure reddening towards individual stars." Thesis, Uppsala universitet, Observationell astrofysik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-296426.

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Interstellar extinction and reddening are inescapable sources of uncertainty in the study of astronomical objects. Many creative ways to measure its effects have been developed, two of them being evaluated in this study. I apply two recently improved methods to estimate extinction toward individual stars, one based on interstellar absorption of sodium and the other based on opacity maps of the interstellar medium. The methods are applied to 14 stars in the local neighborhood, all within a distance of 250 pc from the Sun, and their results are compared. I find that both methods have severe limitations and large uncertainties, but can still be useful under the right conditions. I also provide suggestions on how the methods can be improved.
Interstellär extinktion och rödfärgning är oundvikliga osäkerhetskällor i studiet av astronomiska objekt. Många kreativa sätt att mäta dess effekter har utvecklats, av vilka två utvärderas i denna studie. Jag tillämpar två nyligen förbättrade metoder för att uppskatta utsläckning mot enskilda stjärnor, en baserad på interstellär absorption av natrium och den andra baserad på opacitetskartor över det interstellära mediet. Metoderna tillämpas på 14 stjärnor i solens närområde, alla inom ett avstånd av 250 pc, och deras resultat jämförs. Jag finner att båda metoderna har allvarliga begränsningar och stora osäkerheter, men ändå kan vara användbara under rätt förutsättningar. Jag ger också förslag på hur metoderna kan förbättras.

6

Myers, Alexandra. "A computational study of the effect of cross wind on the flow of fire fighting agent." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Jun%5FMyers.pdf.

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7

Myburgh, Erena. "Evaluating methods for fire protection and related fire risk categories in rural towns of the Western Cape, South Africa." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20066.

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Thesis (MScEng)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: Water flows required for fire protection (fire flows) from water distribution systems (WDS) in rural towns in the Western Cape Province, South Africa, were evaluated as part of this research project. The fire flow requirements specified in different South African guidelines, as well as a number of international standards, were compared. Various guidelines and codes used in South Africa, including the South African National Standards, specify fire flow requirements according to the risk category of the area concerned. Alternative methods of firefighting and new firefighting technologies that can reduce the reliance on potable water resources for firefighting were evaluated. The traditional method of designing a WDS to provide potable water for firefighting, commonly employed in South African municipal areas formed the focus of the study. The potential fire risk costs (potential costs of damages if a fire was to occur) should also be considered, in addition to the network construction costs, when designing a WDS, in order to determine the most economically feasible option. Data obtained from the fire departments of three municipalities in rural towns of the Western Cape, was analysed to determine the actual flow rates that were required to extinguish fires in these towns. The records considered covered approximately one year in each case and included a total of 564 fire incident reports suitable for this study. According to the data, a small fraction (11%) of the fires was extinguished using water from the WDS by connecting firefighting equipment directly to a fire hydrant. The majority of the fires were extinguished by means of water ejected from a firefighting vehicle. This method implies the use of water drawn from the potable network at a certain location; the water is shuttled by firefighting vehicles, from either the fire station or from a central abstraction point in the WDS. The location of the said abstraction point was found to have a notable impact on the WDS and this received attention in this study. The data showed that 99.8% of the flows required in rural towns were lower than the flows recommended for moderate risk areas in typical South African guidelines. Hydraulic modelling of a hypothetical WDS model was conducted to illustrate that the provision of fire flows according to commonly used South African fire flow standards leads to higher costs. The latter hypothetical case study illustrates that designing a network to provide fire flows according to the referred standards resulted in 15% higher costs, compared to designing a network that would have provided for the actual recorded fire flows according to the data set obtained from the selected rural towns compiled for this study. The hypothetical case study also showed that the cost for a WDS, where sufficient pressure is required at all hydrants during peak fire flows, is 2.4% higher than the cost for a distribution system where water is supplied via predetermined hydrants for refilling firefighting vehicles. A WDS with central, predetermined abstraction points for refilling firefighting vehicles offers a solution to providing fire flows in areas where the distribution systems may be inadequate. The revision of the current fire flow standards of South Africa would, therefore, be a logical next step along with the reassessment of methods used for supplying fire flows.
AFRIKAANSE OPSOMMING: Water vloei vir brandbestryding (brandvloei) uit waterverspreidingstelsels (WVS) in plattelandse dorpe in die Wes-Kaap, Suid Afrika, is as deel van hierdie navorsingsprojek geëvalueer. Die brandvloei soos gespesifiseer in verskillende Suid-Afrikaanse riglyne, asook ŉ aantal internasionale standaarde is vergelyk. Verskeie riglyne en kodes wat in Suid-Afrika gebruik word, insluitende die Suid-Afrikaanse Nasionale Standaarde, spesifiseer brandvloei-vereistes op grond van die risiko-kategorie van ŉ spesifieke gebied. ŉ Verskeidenheid alternatiewe metodes vir brandbestryding en nuwe brandbestrydings-tegnologieë is ondersoek, om sodoende die afhanklikheid van ons beperkte drinkbare waterbronne vir brandbestryding te verminder. Die tradisionele metode om water aan munisipale areas te voorsien, die gebruik van ŉ WVS, is ook geassesseer. Hierdie metodes dui daarop dat die potensiële brandgevaar-kostes (potensiële koste van skade indien ŉ brand sou plaas vind) ook in ag geneem moet word, tesame met die konstruksie kostes van ŉ WVS, om sodoende die mees ekonomies haalbare netwerk te bepaal. Data wat verkry is vanaf die brandweer departement van drie plattelandse munisipaliteite in die Wes-Kaap is ontleed om die werklike vloei-tempos vas te stel wat nodig was om brande te blus in hierdie dorpe. Die data is verkry vir ŉ tydperk van een jaar en 564 brandverslae was bruikbaar vir die doeleindes van hierdie studie. Volgens die data was ŉ lae aantal (11%) van die brande geblus vanuit die WVS deur die koppeling van brandbestrydingstoerusting direk aan ŉ brandkraan. Die meeste van die brande is geblus met behulp van water wat voorsien is deur ŉ brandbestrydingsvoertuig. Met hierdie metode word water deur die brandbestrydings-voertuie aangery vanaf die brandweerstasie of onttrek vanuit ŉ sentrale ontrekkingspunt in die WVS. Daar is gevind dat die ligging van laasgenoemde ontrekkingspunt ŉ beduidende impak op die WVS het – hierdie aspek is daarom verder ondersoek. Die data het getoon dat 99.8% van die vloei-tempo’s wat nodig is om brande te blus in plattelandse dorpe, laer is as die brandvloei riglyne vir matige risiko-areas volgens tipes Suid-Afrikaanse standaarde. Hidrouliese modellering van ŉ hipotetiese WVS is uitgevoer om te illustreer dat die verskaffing van brandvloei volgens die standaarde wat algemeen gebruik word, hoër kostes tot gevolg het. Die laasgenoemde hipotetiese gevallestudie illustreer dat ŉ netwerk ontwerp om brandvloei te verskaf volgens die huidige standaarde 15% duurder is as vir netwerke wat ontwerp is om die werklike aangetekende brandvloei te voorsien soos getoon deur die veld-data wat vir hierdie studie verkry is. Die hipotetiese gevallestudie het ook getoon dat die koste vir ŉ WVS, waar voldoende drukke gehandhaaf moet word by alle brandkrane terwyl piek brand vloeie voorsien word, 2.4% duurder is as vir ŉ WVS waar die brandvloei verskaf word by voorafbepaalde brandkrane vir die hervulling van brandbestrydingsvoertuie. ŉ WVS met sentrale onttrekkingspunte vir die hervulling van brandbestrydingsvoertuie, bied ŉ metode om brandvloei te voorsien in gebiede waar die WVS onvoldoende is, bv. informele nedersettings. Die hersiening van die huidige brandvloei standaarde van Suid Afrika sou dus ŉ logiese volgende stap wees, tesame met die herevaluering van die metodes wat gebruik word vir die verskaffing van brandvloei.

8

Sennblad, Adina. "Effects of past fragmentation and habitat loss and current management methods on the changes in vascular plant communities. : An evaluation of extinction debt in semi-natural grasslands in Sweden." Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-447366.

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Habitat loss and fragmentation are believed to be two of the main reasons for high extinction rates of species, resulting in decreased biodiversity. According to the island biogeography theory, the species richness in a patch, here a semi-natural grassland, is dependent on the landscape composition, and therefore changes in the landscape composition will result in changes in the species richness of the grassland. However, this change in species richness may be delayed for several years, causing an extinction debt. The aim of this study was to examine the change of species richness of vascular plants in Swedish semi-natural grasslands between 2007 and 2020 and investigate if there is evidence of an extinction debt and evaluate what factors causes changes in the plant community. Data of species richness and occurrence for 40 semi-natural grasslands, as well as data of landscape changes in area and connectivity between the 1950:s and the 2000:s for these grasslands, were analysed. This study found that changes in species richness in semi-natural grasslands were affected by the changes in connectivity of the landscape. However, the effect depended on the degree of specialisation of the species to semi-natural grassland. Between 2007 and 2020, the species richness of semi- natural grasslands specialist decreased, while the species richness of non-specialist species increased. This resulted in a mean increase of overall species richness between 2007 and 2020. Observed immigration of new non-specialist species appears to suggest that, not only the connectivity, but also the habitat types in the matrix surrounding the semi-natural grasslands may substantially influence the species composition in the grassland; this is in contrast to what is predicted by the original theory of island biogeography. Species that were classified as specialist were more vulnerable to ceased management, such as grazing, than to area and connectivity decrease. This was likely because the ceased management increased the competition for light. The results also indicated that re-established management of abandoned grasslands may increase specialist species richness, highlighting the need for management actions taken in order to reverse extinction debt.

9

Caumont-Prim, Chloé. "Détermination de la distribution de taille des nanoparticules de suie par analyse du spectre d'extinction et de diffusion angulaire de la lumière." Phd thesis, INSA de Rouen, 2013. http://tel.archives-ouvertes.fr/tel-00800137.

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Le but de ce travail est de déterminer par méthodes optiques la distribution de taille (pdf) des nanoparticules de suie, agrégats de morphologie fractale. Après des études préliminaires qui utilisent DDSCAT pour valider la théorie RDG-FA et permettent de convertir un rayon de giration en rayon de mobilité, deux diagnostics optiques sont étudiés. Le premier consiste à exploiter une mesure d'extinction spectrale de la lumière. Nous montrons que pour exploiter ce signal, il faut connaître les propriétés optiques des suies, leur préfacteur et dimension fractale, la loi de distribution et le diamètre des sphérules primaires. Le second diagnostic tire parti de la mesure angulaire de la diffusion de la lumière. Nous montrons qu'il est possible de déterminer la pdf à l'aide de la mesure de diffusion à trois angles. Il faut supposer la loi de distribution et la dimension fractale. Cette deuxième approche, in-situ, est plus appropriée que la première pour déterminer optiquement la pdf des suies.

10

Hautphenne, Sophie. "An algorithmic look at phase-controlled branching processes." Doctoral thesis, Universite Libre de Bruxelles, 2009. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210255.

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Branching processes are stochastic processes describing the evolution of populations of individuals which reproduce and die independently of each other according to specific probability laws. We consider a particular class of branching processes, called Markovian binary trees, where the lifetime and birth epochs of individuals are controlled by a Markovian arrival process.

Our objective is to develop numerical methods to answer several questions about Markovian binary trees. The issue of the extinction probability is the main question addressed in the thesis. We first assume independence between individuals. In this case, the extinction probability is the minimal nonnegative solution of a matrix fixed point equation which can generally not be solved analytically. In order to solve this equation, we develop a linear algorithm based on functional iterations, and a quadratic algorithm, based on Newton's method, and we give their probabilistic interpretation in terms of the tree.

Next, we look at some transient features for a Markovian binary tree: the distribution of the population size at any given time, of the time until extinction and of the total progeny. These distributions are obtained using the Kolmogorov and the renewal approaches.

We illustrate the results mentioned above through an example where the Markovian binary tree serves as a model for female families in different countries, for which we use real data provided by the World Health Organization website.

Finally, we analyze the case where Markovian binary trees evolve under the external influence of a random environment or a catastrophe process. In this case, individuals do not behave independently of each other anymore, and the extinction probability may no longer be expressed as the solution of a fixed point equation, which makes the analysis more complicated. We approach the extinction probability, through the study of the population size distribution, by purely numerical methods of resolution of partial differential equations, and also by probabilistic methods imposing constraints on the external process or on the maximal population size.

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Les processus de branchements sont des processus stochastiques décrivant l'évolution de populations d'individus qui se reproduisent et meurent indépendamment les uns des autres, suivant des lois de probabilités spécifiques.

Nous considérons une classe particulière de processus de branchement, appelés arbres binaires Markoviens, dans lesquels la vie d'un individu et ses instants de reproduction sont contrôlés par un MAP. Notre objectif est de développer des méthodes numériques pour répondre à plusieurs questions à propos des arbres binaires Markoviens.

La question de la probabilité d'extinction d'un arbre binaire Markovien est la principale abordée dans la thèse. Nous faisons tout d'abord l'hypothèse d'indépendance entre individus. Dans ce cas, la probabilité d'extinction s'exprime comme la solution minimale non négative d'une équation de point fixe matricielle, qui ne peut être résolue analytiquement. Afin de résoudre cette équation, nous développons un algorithme linéaire, basé sur l'itération fonctionnelle, ainsi que des algorithmes quadratiques, basés sur la méthode de Newton, et nous donnons leur interprétation probabiliste en termes de l'arbre que l'on étudie.

Nous nous intéressons ensuite à certaines caractéristiques transitoires d'un arbre binaire Markovien: la distribution de la taille de la population à un instant donné, celle du temps jusqu'à l'extinction du processus et celle de la descendance totale. Ces distributions sont obtenues en utilisant l'approche de Kolmogorov ainsi que l'approche de renouvellement.

Nous illustrons les résultats mentionnés plus haut au travers d'un exemple où l'arbre binaire Markovien sert de modèle pour des populations féminines dans différents pays, et pour lesquelles nous utilisons des données réelles fournies par la World Health Organization.

Enfin, nous analysons le cas où les arbres binaires Markoviens évoluent sous une influence extérieure aléatoire, comme un environnement Markovien aléatoire ou un processus de catastrophes. Dans ce cas, les individus ne se comportent plus indépendamment les uns des autres, et la probabilité d'extinction ne peut plus s'exprimer comme la solution d'une équation de point fixe, ce qui rend l'analyse plus compliquée. Nous approchons la probabilité d'extinction au travers de l'étude de la distribution de la taille de la population, à la fois par des méthodes purement numériques de résolution d'équations aux dérivées partielles, ainsi que par des méthodes probabilistes en imposant des contraintes sur le processus extérieur ou sur la taille maximale de la population.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished

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Книги з теми "Extinction methods":

1

Newman, M. E. J. Modeling extinction. New York, NY: Oxford University Press, 2002.

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2

Newman, M. E. J. Modeling extinction. Oxford: Oxford University Press, 2003.

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3

R, Skaggs Stephanie, and National Institute of Standards and Technology (U.S.), eds. Screening methods for agent compatibility with people, materials, and the environment. Gaithersburg, MD: U.S. Dept. of Commerce, Technology Administration, National Institute of Standards and Technology, 1999.

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4

International Conference on Performance-Based Codes and Fire Safety Design Methods. Proceedings, 4th International Conference on Performance-Based Codes and Fire Safety Design Methods: 20-22 March 2002, Melbourne Exhibitions & Convention Centre, Melbourne, Australia. [Bethesda, Md.]: Society of Fire Protection Engineers, 2002.

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5

E, Holmes E., and Northwest Fisheries Science Center (U.S.), eds. Cross validation of quasi-extinction risks from real time series: An examination of diffusion approximation methods. Seattle, Wash: U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Fisheries Service, Northwest Fisheries Science Center, 2005.

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6

McClincy, William D. Instructional methods in emergency services: A resource text designed for EMS, fire, and rescue instructors. Englewood Cliffs, N.J: Brady Prentice Hall, 1995.

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7

Lindsey, Jeffrey. Fire service instructor. Upper Saddle River, N.J: Pearson Prentice Hall, 2006.

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8

Maher, Patrick T. Designing emergency scene simulations for police and fire promotional examiniations. La Palma, Calif: Personnel and Organization Development Consultants, 1993.

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9

Amato, George. Conservation genetics in the age of genomics. New York: Columbia University Press, 2009.

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10

Gross, S. S. Improved method for extinguishing coal refuse fires. [Pittsburgh, PA]: Bureau of Mines, U.S. Dept. of the Interior, 1991.

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Частини книг з теми "Extinction methods":

1

Lieberman, Mira. "Research Methods." In Extinction Governance, Finance and Accounting, 530–48. London: Routledge, 2022. http://dx.doi.org/10.4324/9781003045557-35.

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2

Knude, Jens. "Methods to Account for Interstellar Extinction." In Census of the Galaxy: Challenges for Photometry and Spectrometry with GAIA, 97–107. Dordrecht: Springer Netherlands, 2002. http://dx.doi.org/10.1007/978-94-010-0361-2_15.

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3

Santovito, Luca Spiro, and Graziano Pinna. "Preclinical Methods of Neurosteroid-Induced Facilitation of Fear Extinction and Fear Extinction Retention." In Translational Methods for PTSD Research, 325–48. New York, NY: Springer US, 2023. http://dx.doi.org/10.1007/978-1-0716-3218-5_15.

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4

Drummond, Katherine, and Jee Hyun Kim. "Periadolescent Social Isolation Effects on Extinction of Conditioned Fear." In Translational Methods for PTSD Research, 23–35. New York, NY: Springer US, 2023. http://dx.doi.org/10.1007/978-1-0716-3218-5_2.

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5

Suzuki, Takao K., Motomu Matsui, Sira Sriswasdi, and Wataru Iwasaki. "Lifestyle Evolution Analysis by Binary-State Speciation and Extinction (BiSSE) Model." In Methods in Molecular Biology, 327–42. New York, NY: Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-2691-7_16.

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6

Mcfarlane, Donald A. "A Comparison of Methods for the Probabilistic Determination of Vertebrate Extinction Chronologies." In Extinctions in Near Time, 95–103. Boston, MA: Springer US, 1999. http://dx.doi.org/10.1007/978-1-4757-5202-1_5.

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7

Velasco, Eric Raul, Antonio Florido, Ignacio Javier Marin-Blasco, Patricia Molina, Laura Perez-Caballero, and Raul Andero. "Stress Immobilization Inducing Fear Extinction Deficits in Male and Female Mice." In Translational Methods for PTSD Research, 191–201. New York, NY: Springer US, 2023. http://dx.doi.org/10.1007/978-1-0716-3218-5_9.

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8

Marusak, Hilary A., Craig Peters, and Christine A. Rabinak. "Using Virtual Reality to Study Fear and Extinction in Children and Adolescents." In Translational Methods for PTSD Research, 37–49. New York, NY: Springer US, 2023. http://dx.doi.org/10.1007/978-1-0716-3218-5_3.

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9

Miller, Dylan B., Madeleine M. Rassaby, Zhenfu Wen, and Mohammed R. Milad. "Pavlovian Conditioning and Extinction Methods for Studying the Neurobiology of Fear Learning in PTSD." In Translational Methods for PTSD Research, 97–115. New York, NY: Springer US, 2023. http://dx.doi.org/10.1007/978-1-0716-3218-5_5.

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10

Mohammadi Ziabari, Seyed Sahand, and Jan Treur. "An Adaptive Cognitive Temporal-Causal Model for Extreme Emotion Extinction Using Psilocybin." In Computational Statistics and Mathematical Modeling Methods in Intelligent Systems, 176–86. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-31362-3_18.

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Тези доповідей конференцій з теми "Extinction methods":

1

Perez, Maximillian A., Steffen Kross, Jeff De Natale, Rob Mihailovich, Jaime Ramirez-Serrano, and Megan Ivory. "High-extinction chip-scale shuttering for quantum technologies." In Novel Optical Systems, Methods, and Applications XXII, edited by Cornelius F. Hahlweg and Joseph R. Mulley. SPIE, 2019. http://dx.doi.org/10.1117/12.2527220.

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2

Andrews, Gordon E., N. T. Ahmed, Roth Phylaktou, and Phil King. "Weak Extinction in Low NOx Gas Turbine Combustion." In ASME Turbo Expo 2009: Power for Land, Sea, and Air. ASMEDC, 2009. http://dx.doi.org/10.1115/gt2009-59830.

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Well mixed low NOx gas turbines are limited, in the operational range of the low NOx mode, by the weak extinction and CO limits of the flame stabiliser used. The operational range of the combustor in the <10ppm low NOx mode is set by the range of equivalence ratios over which ultra low NOx without acoustic resonance can be achieved. This paper reviews the available data on weak extinction in well mixed low NOx combustion systems and presents some new data. Atmospheric pressure weak extinction data is shown to be similar to weak extinction at pressure for similar stabiliser designs and reference velocities. For low NOx gas turbine combustion it is demonstrated that all the best weak extinctions are identical to the lean flammability limit for laminar flames. Weak extinction is where the flow velocity exceeds the turbulent burning velocity and data on weak extinction is used as a measure of the mean turbulent burning velocity and shown to correlate with turbulent burning velocity data and theories. Methods of predicting the peak turbulence generated downstream of a flame stabiliser are outlined, based on grid plate measurements of turbulence and pressure loss. It is shown that a wide range of premixed flame stabilisers including swirling and non-swirling flame stabilisers have a weak extinction that can be predicted using this method.

3

Ma, Yunfeng, Shanshan Chang, Lifen Liao, Chunmin Tian, Wang Cheng, Peng Zhao, and Nan Jiang. "Research on two test methods of polarizer extinction ratio." In Micro- and Nano-Optics, Catenary Optics, and Subwavelength Electromagnetics, edited by Reinhart Poprawe, Bin Fan, Xiong Li, Min Gu, Mingbo Pu, and Xiangang Luo. SPIE, 2019. http://dx.doi.org/10.1117/12.2506163.

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4

Ferri, Fabio, Enrico Paganini, and Luca De Stefano. "Particle Sizing from Spectral Extinction Data." In Photon Correlation and Scattering. Washington, D.C.: Optica Publishing Group, 1996. http://dx.doi.org/10.1364/pcs.1996.fc.2.

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Particle sizing is a topic of great interest for the characterization of many biological, chemical and physical systems. Among the techniques which deal with particle sizing, the optical methods and, in particular the scattering techniques, are the most suitable and convenient ones. Indeed, they allow the characterization of a large number of particles to be carried out in situ and in real time. Scattering techniques include dynamic light scattering for studying submicron particles, low angle elastic light scattering for particles larger than microns, and spectral extinction methods for particles of intermediate size. This last method is probably the most convenient one since it requires a very simple optical layout, obtainable, for example, by adapting commercial spectrophotometers.

5

Kovalev, Vladimir A., Michael P. Bristow, James L. McElroy, and Raul J. Alvarez. "Compensational Methods for Retrieving Ozone Concentration Profiles with a Multiwavelength DIAL System." In Optical Remote Sensing of the Atmosphere. Washington, D.C.: Optica Publishing Group, 1995. http://dx.doi.org/10.1364/orsa.1995.tuc23.

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Uncertainty in the spectral dependencies of atmospheric aerosol backscattering and extinction produces an uncertainty in the corresponding correction terms in the DIAL equation used to determine O3 concentration values, especially in turbid atmospheres where large aerosol backscattering gradients exist. Two ways exist for reducing the systematic distortion in ozone concentration profiles caused by aerosol differential extinction and backscattering, viz. i) to correct the calculated O3 profile using assumed atmospheric spectral dependencies for extinction (total scattering) and backscattering (the conventional correction method), or ii) to reduce this distortion using new methods for processing an extended DIAL signal set measured simultaneously at a number of wavelengths (the compensational method).

6

Wang, Xiaobin, Bin Xu, Zhengzheng Ma, and Shunxing Hu. "New Measurement Methods of Dust Charge Based on Infrared Extinction Theory." In 2018 12th International Symposium on Antennas, Propagation and EM Theory (ISAPE). IEEE, 2018. http://dx.doi.org/10.1109/isape.2018.8634214.

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7

Chiba, Kazuhisa, Masahiro Kanazaki, and Toru Shimada. "MANIFESTATION OF ASCENDANCY OF EXTINCTION-REIGNITION ON SOUNDING HYBRID ROCKET USING DESIGN INFORMATICS." In VII European Congress on Computational Methods in Applied Sciences and Engineering. Athens: Institute of Structural Analysis and Antiseismic Research School of Civil Engineering National Technical University of Athens (NTUA) Greece, 2016. http://dx.doi.org/10.7712/100016.2422.6360.

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8

Hall, Freeman F. "Cirrus cloud transmittance and backscatter measured with an infrared CO2 lidar." In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1987. http://dx.doi.org/10.1364/oam.1987.mz5.

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We have measured the transmittance of cirrus clouds at 10.59-μm wavelength with a CO2 lidar using two independent methods. The first method used backscatter from the calibration target El Chichon stratospheric cloud that was present over Boulder during 1982 and 1983. The second method used conical lidar scans at different zenith angles when uniform cirrus decks were present during the 1986 FIRE intensive observations in Oshkosh, WI. Extinction coefficients from both methods average 0.1 km−1 for thin cirrus, 0.5 km thick to 0.6 km−1 for cirrus several kilometers thick. There is a wide standard deviation in extinction values. Extinction to backscatter ratios vary from ~800 sr for thin clouds to 2600 sr for thick clouds.

9

Reinhardt, C. N., D. T. Wayne, K. M. McBryde, and A. K. Ascencio. "Machine Learning Methods for the Analysis of Turbulence- and Extinction-Degraded Imagery." In Imaging Systems and Applications. Washington, D.C.: OSA, 2014. http://dx.doi.org/10.1364/isa.2014.im4c.4.

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10

Prakash, Shashvat, Yedidia Neumeier, and Ben T. Zinn. "Blowout Margin Estimation Based on Two Precursor Types." In ASME Turbo Expo 2007: Power for Land, Sea, and Air. ASMEDC, 2007. http://dx.doi.org/10.1115/gt2007-27874.

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Lean, premixed combustion has been aggressively pursued in recent years because it offers a practical approach for reducing emissions of nitrogen oxides (NOx) from gas turbines. However, lean premixed flames pose a greater risk of blowout. Studies on swirl and dump stabilized flames have shown that as a flame approaches blowout, distinctive precursors occur, such as pockets of localized extinctions and brief flame shape transitions to a thin ‘tornado’ configuration. For this study, both precursor types are detected using separate, dedicated optical sensors. Observations indicate that the tornado mode is part of the blowout process in a 127 mm long combustor and that a localized extinction precursor immediately precedes the tornado mode transition. Despite the causality, the statistics of tornado bursts and localized extinctions suggest a ‘memoryless’ Poisson process, where the occurrence of one event type does not influence the time until the next event of the same type. Localized extinctions have been used previously for blowout margin estimation, and are well suited for the purpose because the occurrence frequency increases with diminishing margin. However, the signals commonly used to detect localized extinction events are noisy due to the nature of the flame; thus, detection is prone to false alarms. Detecting tornado bursts, by comparison, is less ambiguous but such events occur too rarely for blowout mitigation applications. The shortcomings of both precursor detection methods can be addressed by combining observations of both precursor types in a meaningful manner. The presence of tornado bursts indicates that the flame is near blowout; this fact can be used to calibrate margin estimation routines based upon localized extinction. However, this approach would require two sensors since any one optical sensor cannot directly differentiate both precursor types. A single sensor approach can be developed whereby the causal relationship between the two precursor types is exploited. Local extinctions with longer duration times can potentially perturb the flame into an alternate flow configuration. The presence of these tornado ‘triggers’ manifest as an increase in the low frequency content of the chemiluminescence signal. A low pass filter with the appropriate cutoff frequency can differentiate between the tornado-triggering and benign, inconsequential localized extinctions. Therefore, the same signal that detects localized extinctions can be filtered to capably predict tornado mode shifts. This scheme will enable robust margin detection and minimize sensitivity to noise.

Звіти організацій з теми "Extinction methods":

1

Paulson, M. R. Utility of a Dual-Lidar Method to Measure Integrated Extinction. Fort Belvoir, VA: Defense Technical Information Center, November 1988. http://dx.doi.org/10.21236/ada203145.

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Minagawa, Tomohiro, Makoto Shimono, Toshihiko Muramatsu, Fumihide Sato, and Takeyuki Kamimoto. Temporal Measurements of Trapping Efficiency of a DPF by a Laser Extinction Method. Warrendale, PA: SAE International, May 2005. http://dx.doi.org/10.4271/2005-08-0278.

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