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The Importance of Adhesive Area Delimitation in a Microshear Bond Strength Experimental Design

SHIMAOKA, Angela M.; ANDRADE, Alessandra P. de; CARDOSO, Marcio V.; CARVALHO, Rubens C. R. de
Fonte: QUINTESSENCE PUBLISHING CO INC Publicador: QUINTESSENCE PUBLISHING CO INC
Tipo: Artigo de Revista Científica
ENG
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27.31%
Purpose: The purpose of this study was to assess the influence of adhesive area delimitation on the microshear bond strength of different adhesives to dentin. Materials and Methods: Eighteen bovine incisors were sectioned and the exposed dentin surfaces were prepared with 600-grit SIC paper. These teeth were randomly divided into three groups, according to the adhesive to be applied: two-step etch-and-rinse Adper Single Bond 2 (3M ESPE), two-step self-etching Clearfil SE Bond (Kuraray), and one-step Clearfil S(3) Bond (Kuraray). On each dentin surface, 4 samples were built up with the composite resin Z100 (3M ESPE); on 2 of these, a suggested area delimitation technique was employed. After 24 h of storage in water at 37 degrees C, samples were subjected to the microshear bond strength test, and the failure modes were evaluated under optical and scanning electron microscopes. The obtained results were statistical analyzed using two-way ANOVA and Tukey`s test. Results: Groups without area delimitation presented significantly higher bond strength results (p < 0.05) and a higher incidence of cohesive failures. In these groups, fractures tended to occur beyond the limits of the actual adhesive area, while the area restriction technique succeeded in avoiding this phenomenon. The three adhesives performed similarly when area delimitation was employed (p > 0.05)...

Out of the deep: Cryptic speciation in a Neotropical gecko (Squamata, Phyllodactylidae) revealed by species delimitation methods

Domingos, Fabricius M. C. B.; Bosque, Renan J.; Cassimiro, José; Colli, Guarino R.; Rodrigues, Miguel Trefaut Urbano; Santos, Marcella G.; Beheregaray, Luciano B.
Fonte: Elsevier Inc.; Maryland Heights Publicador: Elsevier Inc.; Maryland Heights
Tipo: Artigo de Revista Científica
ENG
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37.18%
Levels of biodiversity in the Neotropics are largely underestimated despite centuries of research interest in this region. This is particularly true for the Cerrado, the largest Neotropical savanna and a formally recognized biodiversity hotspot. Molecular species delimitation methods have become essential tools to uncover cryptic species and can be notably robust when coupled with morphological information. We present the first evaluation of the monophyly and cryptic speciation of a widespread Cerrado endemic lizard, Gymnodactylus amarali, using phylogenetic and species-trees methods, as well as a coalescent-based Bayesian species delimitation method. We tested whether lineages resulting from the analyses of molecular data are morphologically diagnosed by traditional meristic scale characters. We recovered eight deeply divergent molecular clades within G. amarali, and two additional ones from seasonally dry tropical forest enclaves between the Cerrado and the Caatinga biomes. Analysis of morphological data statistically corroborated the molecular delimitation for all groups, in a pioneering example of the use of support vector machines to investigate morphological differences in animals. The eight G. amarali clades appear monophyletic and endemic to the Cerrado. They display several different properties used by biologists to delineate species and are therefore considered here as candidates for formal taxonomic description. We also present a preliminary account of the biogeographic history of these lineages in the Cerrado...

Influência da delimitação da área adesiva no ensaio mecânico de microcisalhamento; Evaluation of adhesive area delimitation on microshear test

Shimaoka, Angela Mayumi
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 26/06/2007 PT
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37.46%
Este estudo teve como objetivos avaliar se a delimitação da área adesiva a ser testada no ensaio mecânico de microcisalhamento é capaz de alterar os resultados de resistência de união obtidos; determinar se a delimitação da área adesiva do ensaio mecânico de microcisalhamento pode alterar o ranqueamento dos sistemas adesivos analisados e correlacionar os tipos de fratura encontrados com valores de resistência adesiva obtidos em cada um dos grupos experimentais. As unidades experimentais foram confeccionadas sobre 18 superfícies de dentina obtidas a partir de incisivos bovinos distribuídas aleatoriamente em 3 grupos, segundo o sistema adesivo a ser utilizado (Adper Single Bond 2, Clearfil Se Bond, Clearfil S3 Bond). Desta forma foram compostos 6 grupos experimentais segundo os dois fatores de variação a serem estudados: sistema adesivo e delimitação da área adesiva. Sobre cada superfície dentinária foram confeccionados 4 cilindros em resina composta, sendo 2 com delimitação da área adesiva e 2 sem a delimitação desta área, totalizando n=12. Após 24 horas de armazenamento os espécimes foram submetidos ao ensaio mecânico de microcisalhamento. O teste estatístico ANOVA (p<0,01) e o teste auxiliar de Tukey determinaram que todos os grupos experimentais em que a delimitação da área adesiva foi realizada apresentaram menores valores de resistência adesiva quando comparados aos seus respectivos grupos controle (sem delimitação da área adesiva). Para os grupos em que não foi realizada a delimitação da área não foram observadas diferenças estatisticamente significantes entre os adesivos empregados. Em contrapartida...

Investigação de limites específicos em Corbula (Corbulidae: Bivalvia) do Sudeste e Sul do Brasil, com base em marcadores moleculares; Species boundaries in Corbula (Corbulidae: Bivalvia) from South-Southeastern Brazil based on molecular markers

Monica Paiva Quast
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 31/01/2013 PT
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27.08%
Espécies são unidades fundamentais da biologia e sua identificação é essencial para a pesquisa nos mais diversos campos. Esta tarefa, no entanto, é dificultada por limites interespecíficos naturalmente mal definidos, especialmente em ambientes marinhos, onde complexos de espécies crípticas são comuns. Assim, a delimitação de espécies tem recebido grande atenção nos últimos anos e técnicas moleculares têm se mostrado de grande importância para a questão. Corbula (Bivalvia: Corbulidae) é um gênero frequente e ecologicamente importante em comunidades bentônicas marinhas de sublitoral. A taxonomia do grupo é bastante confusa, em parte devido à plasticidade fenotípica das conchas que dificulta o estabelecimento de limites morfológicos entre as espécies. O presente estudo teve como objetivo estudar, com base em sequências de dois marcadores moleculares (COI e 16S), os limites entre seis espécies de Corbula morfologicamente identificadas da costa sudeste e sul do Brasil, de forma a testar a delimitação morfológica. Como se trata de espécies predominantemente de sublitoral, o material analisado encontrava-se preservado em álcool, havendo sido fixado em formol. Dessa forma, fez-se necessário o desenvolvimento de protocolos específicos de extração e amplificação. Uma combinação de extração orgânica com adsorção em sílica mostrou-se o melhor método de extração de DNA total. Para as reações de amplificação...

Inventariação e análise dos autos de delimitação do Domínio Público Marítimo na área de intervenção da Polis Litoral - Ria de Aveiro

Pontes, Diogo Alberto Lourenço
Fonte: ISA/UTL Publicador: ISA/UTL
Tipo: Dissertação de Mestrado
Publicado em //2012 POR
Relevância na Pesquisa
27.26%
Mestrado em Engenharia do Ambiente - Instituto Superior de Agronomia; The procedure of delimitation of the Public Domain Water (DPH) determines the limits of the Maritime Public Domain (DPM) in the confrontation with another ground natures. This procedure is reflected by the publication of the Delimitation Act. According to the Law of Ownership of Water Resources, the Portuguese Water Institute (INAG) has the jurisdiction on the inventory of the Delimitation Act. In this context, the aims of this work are to inventor, systematize and review of published Delimitation Act of DPM in the area of Polis Litoral - Ria de Aveiro. In order to meet the proposed objectives, was developed a methodology of analysis that contemplates beyond the analysis of the delimitation Act, a comparative analysis of the published limits of DPM with limits estimated by applying the criteria (approved by INAG) for demarcation of the seabed and margin for the effect of identification of the jurisdiction area of the Portuguese Water Authority. The errors/anomalies resultant from the application of the methodology has two distinct origins: Act errors and comparison anomalies. To be statistically analyzed they were divided into classes in order to test the interaction between the errors classes. It was concluded that interactions exist between the errors classes.

Bayesian species delimitation in West African forest geckos (Hemidactylus fasciatus)

Leaché, Adam D.; Fujita, Matthew K.
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.26%
Genealogical data are an important source of evidence for delimiting species, yet few statistical methods are available for calculating the probabilities associated with different species delimitations. Bayesian species delimitation uses reversible-jump Markov chain Monte Carlo (rjMCMC) in conjunction with a user-specified guide tree to estimate the posterior distribution for species delimitation models containing different numbers of species. We apply Bayesian species delimitation to investigate the speciation history of forest geckos (Hemidactylus fasciatus) from tropical West Africa using five nuclear loci (and mtDNA) for 51 specimens representing 10 populations. We find that species diversity in H. fasciatus is currently underestimated, and describe three new species to reflect the most conservative estimate for the number of species in this complex. We examine the impact of the guide tree, and the prior distributions on ancestral population sizes (θ) and root age (τ0), on the posterior probabilities for species delimitation. Mis-specification of the guide tree or the prior distribution for θ can result in strong support for models containing more species. We describe a new statistic for summarizing the posterior distribution of species delimitation models...

Species Delimitation and Global Biosecurity

Boykin, Laura M.; Armstrong, Karen F.; Kubatko, Laura; De Barro, Paul
Fonte: Libertas Academica Publicador: Libertas Academica
Tipo: Artigo de Revista Científica
Publicado em 08/12/2011 EN
Relevância na Pesquisa
27.31%
Species delimitation directly impacts on global biosecurity. It is a critical element in the decisions made by national governments in regard to the flow of trade and to the biosecurity measures imposed to protect countries from the threat of invasive species. Here we outline a novel approach to species delimitation, “tip to root”, for two highly invasive insect pests, Bemisia tabaci (sweetpotato whitefly) and Lymantria dispar (Asian gypsy moth). Both species are of concern to biosecurity, but illustrate the extremes of phylogenetic resolution that present the most complex delimitation issues for biosecurity; B. tabaci having extremely high intra-specific genetic variability and L. dispar composed of relatively indistinct subspecies. This study tests a series of analytical options to determine their applicability as tools to provide more rigorous species delimitation measures and consequently more defensible species assignments and identification of unknowns for biosecurity. Data from established DNA barcode datasets (COI), which are becoming increasingly considered for adoption in biosecurity, were used here as an example. The analytical approaches included the commonly used Kimura two-parameter (K2P) inter-species distance plus four more stringent measures of taxon distinctiveness...

Species delimitation and digit number in a North African skink

Brown, R P; Tejangkura, T; El Mouden, E H; Ait Baamrane, M A; Znari, M
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.18%
Delimitation of species is an important and controversial area within evolutionary biology. Many species boundaries have been defined using morphological data. New genetic approaches now offer more objective evaluation and assessment of the reliability of morphological variation as an indicator that speciation has occurred. We examined geographic variation in morphology of the continuously distributed skink Chalcides mionecton from Morocco and used Bayesian analyses of nuclear and mitochondrial DNA (mtDNA) loci to examine: (i) their concordance with morphological patterns, (ii) support for species delimitation, (iii) timing of speciation, and (iv) levels of gene flow between species. Four digit individuals were found at sites between Cap Rhir (in the south) and the northern extreme of the range, whereas five-digit individuals were found in two disjunct areas: (i) south of Cap Rhir and (ii) the north of the range where they were often syntopic with four-digit individuals. The pattern of variation in generalized body dimensions was largely concordant with that in digit number, suggesting two general morphotypes. Bayesian analyses of population structure showed that individuals from sites south of Cap Rhir formed one genetic cluster, but that northern four- and five-digit individuals clustered together. Statistical support for delimitation of these genetic clusters into two species was provided by a recent Bayesian method. Phylogenetic–coalescent dating with external time calibrations indicates that speciation was relatively recent...

New Metrics for Comparison of Taxonomies Reveal Striking Discrepancies among Species Delimitation Methods in Madascincus Lizards

Miralles, Aurélien; Vences, Miguel
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 12/07/2013 EN
Relevância na Pesquisa
27.08%
Delimiting and describing species is fundamental to numerous biological disciplines such as evolution, macroecology, and conservation. Delimiting species as independent evolutionary lineages may and often does yield different outcomes depending on the species criteria applied, but methods should be chosen that minimize the inference of objectively erroneous species limits. Several protocols exploit single-gene or multi-gene coalescence statistics, assignment tests or other rationales related to nuclear DNA (nDNA) allele sharing to automatically delimit species. We apply seven different species delimitation protocols to a taxonomically confusing group of Malagasy lizards (Madascincus), and compare the resulting taxonomies with two newly developed metrics: the Taxonomic index of congruence Ctax which quantifies the congruence between two taxonomies, and the Relative taxonomic resolving power index Rtax which quantifies the potential of an approach to capture a high number of species boundaries. The protocols differed in the total number of species proposed, between 9 and 34, and were also highly incongruent in placing species boundaries. The Generalized Mixed Yule-Coalescent approach captured the highest number of potential species boundaries but many of these were clearly contradicted by extensive nDNA admixture between sympatric mitochondrial DNA (mtDNA) haplotype lineages. Delimiting species as phenotypically diagnosable mtDNA clades failed to detect two cryptic species that are unambiguous due to a lack of nDNA gene flow despite sympatry. We also consider the high number of species boundaries and their placement by multi-gene Bayesian species delimitation as poorly reliable whereas the Bayesian assignment test approach provided a species delimitation highly congruent with integrative taxonomic practice. The present study illustrates the trade-off in taxonomy between reliability (favored by conservative approaches) and resolving power (favored by inflationist approaches). Quantifying excessive splitting is more difficult than quantifying excessive lumping...

Rigorous approaches to species delimitation have significant implications for African crocodilian systematics and conservation

Shirley, Matthew H.; Vliet, Kent A.; Carr, Amanda N.; Austin, James D.
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
Publicado em 07/02/2014 EN
Relevância na Pesquisa
27.08%
Accurate species delimitation is a central assumption of biology that, in groups such as the Crocodylia, is often hindered by highly conserved morphology and frequent introgression. In Africa, crocodilian systematics has been hampered by complex regional biogeography and confounded taxonomic history. We used rigorous molecular and morphological species delimitation methods to test the hypothesis that the slender-snouted crocodile (Mecistops cataphractus) is composed of multiple species corresponding to the Congolian and Guinean biogeographic zones. Speciation probability was assessed by using 11 mitochondrial and nuclear genes, and cranial morphology for over 100 specimens, representing the full geographical extent of the species distribution. Molecular Bayesian and phylogenetic species delimitation showed unanimous support for two Mecistops species isolated to the Upper Guinean and Congo (including Lower Guinean) biomes that were supported by 13 cranial characters capable of unambiguously diagnosing each species. Fossil-calibrated phylogenetic reconstruction estimated that the species split ± 6.5–7.5 Ma, which is congruent with intraspecies divergence within the sympatric crocodile genus Osteolaemus and the formation of the Cameroon Volcanic Line. Our results underscore the necessity of comprehensive phylogeographic analyses within currently recognized taxa to detect cryptic species within the Crocodylia. We recommend that the community of crocodilian researchers reconsider the conceptualization of crocodilian species especially in the light of the conservation ramifications for this economically and ecologically important group.

Species detection and individual assignment in species delimitation: can integrative data increase efficacy?

Edwards, Danielle L.; Knowles, L. Lacey
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
Publicado em 22/02/2014 EN
Relevância na Pesquisa
27.26%
Statistical species delimitation usually relies on singular data, primarily genetic, for detecting putative species and individual assignment to putative species. Given the variety of speciation mechanisms, singular data may not adequately represent the genetic, morphological and ecological diversity relevant to species delimitation. We describe a methodological framework combining multivariate and clustering techniques that uses genetic, morphological and ecological data to detect and assign individuals to putative species. Our approach recovers a similar number of species recognized using traditional, qualitative taxonomic approaches that are not detected when using purely genetic methods. Furthermore, our approach detects groupings that traditional, qualitative taxonomic approaches do not. This empirical test suggests that our approach to detecting and assigning individuals to putative species could be useful in species delimitation despite varying levels of differentiation across genetic, phenotypic and ecological axes. This work highlights a critical, and often overlooked, aspect of the process of statistical species delimitation—species detection and individual assignment. Irrespective of the species delimitation approach used...

Unguided Species Delimitation Using DNA Sequence Data from Multiple Loci

Yang, Ziheng; Rannala, Bruce
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.36%
A method was developed for simultaneous Bayesian inference of species delimitation and species phylogeny using the multispecies coalescent model. The method eliminates the need for a user-specified guide tree in species delimitation and incorporates phylogenetic uncertainty in a Bayesian framework. The nearest-neighbor interchange algorithm was adapted to propose changes to the species tree, with the gene trees for multiple loci altered in the proposal to avoid conflicts with the newly proposed species tree. We also modify our previous scheme for specifying priors for species delimitation models to construct joint priors for models of species delimitation and species phylogeny. As in our earlier method, the modified algorithm integrates over gene trees, taking account of the uncertainty of gene tree topology and branch lengths given the sequence data. We conducted a simulation study to examine the statistical properties of the method using six populations (two sequences each) and a true number of three species, with values of divergence times and ancestral population sizes that are realistic for recently diverged species. The results suggest that the method tends to be conservative with high posterior probabilities being a confident indicator of species status. Simulation results also indicate that the power of the method to delimit species increases with an increase of the divergence times in the species tree...

Effects of phylogenetic reconstruction method on the robustness of species delimitation using single-locus data

Tang, Cuong Q; Humphreys, Aelys M; Fontaneto, Diego; Barraclough, Timothy G; Paradis, Emmanuel
Fonte: John Wiley & Sons Ltd Publicador: John Wiley & Sons Ltd
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.08%
Coalescent-based species delimitation methods combine population genetic and phylogenetic theory to provide an objective means for delineating evolutionarily significant units of diversity. The generalised mixed Yule coalescent (GMYC) and the Poisson tree process (PTP) are methods that use ultrametric (GMYC or PTP) or non-ultrametric (PTP) gene trees as input, intended for use mostly with single-locus data such as DNA barcodes. Here, we assess how robust the GMYC and PTP are to different phylogenetic reconstruction and branch smoothing methods. We reconstruct over 400 ultrametric trees using up to 30 different combinations of phylogenetic and smoothing methods and perform over 2000 separate species delimitation analyses across 16 empirical data sets. We then assess how variable diversity estimates are, in terms of richness and identity, with respect to species delimitation, phylogenetic and smoothing methods. The PTP method generally generates diversity estimates that are more robust to different phylogenetic methods. The GMYC is more sensitive, but provides consistent estimates for BEAST trees. The lower consistency of GMYC estimates is likely a result of differences among gene trees introduced by the smoothing step. Unresolved nodes (real anomalies or methodological artefacts) affect both GMYC and PTP estimates...

Assessing Species Boundaries Using Multilocus Species Delimitation in a Morphologically Conserved Group of Neotropical Freshwater Fishes, the Poecilia sphenops Species Complex (Poeciliidae)

Bagley, Justin C.; Alda, Fernando; Breitman, M. Florencia; Bermingham, Eldredge; van den Berghe, Eric P.; Johnson, Jerald B.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 07/04/2015 EN
Relevância na Pesquisa
27.18%
Accurately delimiting species is fundamentally important for understanding species diversity and distributions and devising effective strategies to conserve biodiversity. However, species delimitation is problematic in many taxa, including ‘non-adaptive radiations’ containing morphologically cryptic lineages. Fortunately, coalescent-based species delimitation methods hold promise for objectively estimating species limits in such radiations, using multilocus genetic data. Using coalescent-based approaches, we delimit species and infer evolutionary relationships in a morphologically conserved group of Central American freshwater fishes, the Poecilia sphenops species complex. Phylogenetic analyses of multiple genetic markers (sequences of two mitochondrial DNA genes and five nuclear loci) from 10/15 species and genetic lineages recognized in the group support the P. sphenops species complex as monophyletic with respect to outgroups, with eight mitochondrial ‘major-lineages’ diverged by ≥2% pairwise genetic distances. From general mixed Yule-coalescent models, we discovered (conservatively) 10 species within our concatenated mitochondrial DNA dataset, 9 of which were strongly supported by subsequent multilocus Bayesian species delimitation and species tree analyses. Results suggested species-level diversity is underestimated or overestimated by at least ~15% in different lineages in the complex. Nonparametric statistics and coalescent simulations indicate genealogical discordance among our gene tree results has mainly derived from interspecific hybridization in the nuclear genome. However...

Eingrenzung der Leichenliegezeit mittels immunhistochemischer Untersuchung des Glial Fibrillary Acidic Protein (GFAP) in Astrocyten; Delimitation of the time of death by immunhistochemical detection of GFAP (Glial Fibrillary Acidic Protein) in astrocytes

Steinriede, Anja
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
Relevância na Pesquisa
27.08%
Die Eingrenzung des Todeszeitpunktes von Leichen wird immer schwieriger und ungenauer, je weiter der Todeszeitpunkt zurück liegt. Mit dieser Arbeit soll ein immunhistochemisches Verfahren zur Bestimmung der Liegezeit (Langliegezeit – Tage bis Wochen) von Leichen untersucht werden. Gehirnschnitte von 498 Leichen des Institutes für Gerichtliche Medizin der Universität Tübingen wurden mit monklonalen Antikörpern (Fa DAKO A/S: Monoclonal Mouse Anti-Human Glial Fibrillary acidic Protein) immunhistochemisch gefärbt. Es wurde ein statistisches Modell entwickelt, das färbeergebnisabhängige Wahrscheinlichkeitsangaben zum Todeszeitpunkt ermöglicht. Des weiteren wurde der Einfluss von Umgebungsbedingungen in Form von Fundort und Jahreszeit berücksichtigt. Eine zeitabhängige Anfärbbarkeit ist gegeben. Bis einschließlich 3. postmortalem Tag waren alle Schnitte immunhistochemisch anfärbbar. Ab dem 14. Tag post mortem traten durchweg negative Färbeergebnisse auf. Im Zeitraum dazwischen sank der Anteil der anfärbbaren Präparate. Ein zusätzlicher Einfluss auf die Anfärbbarkeit konnte für die Faktoren Temperatur, Luftfeuchtigkeit und Jahreszeit nachgewiesen werden. Eine weitere Eingrenzung der Liegezeit war durch den Vergleich verschiedener immunhistochemischer Färbungen von Proteinen möglich. Immunhistochemische Färbemethoden stellen ein kostengünstiges und universell einsetzbares Verfahren zur Todeszeitbestimmung dar. Insbesondere durch Kombination von Färbungen unterschiedlicher Proteine lässt sich eine präzise Vorhersage über die Liegezeit einer Leiche treffen.; The delimitation of the time of death becomes even more difficult and inaccurate the further back it lays in time. With this study we established a immunhistochemical method to determine the time since death of dead corposes (postmortem intervall from days to weeks). Tissue slices of 498 corpses from the Institute of Science and Forensic Medicine of the University of Tuebingen were stained with an monoclonal antibody (DAKO A/S...

Delimiting species in recent radiations with low levels of morphological divergence: A case study in Australian Gehyra geckos

Sistrom, M.; Donnellan, S.; Hutchinson, M.
Fonte: Academic Press Inc Elsevier Science Publicador: Academic Press Inc Elsevier Science
Tipo: Artigo de Revista Científica
Publicado em //2013 EN
Relevância na Pesquisa
27.26%
Recent conceptual and methodological advances have increased the ability to apply multifaceted approaches to species delimitation, which is particularly useful in delimiting recently diversified species where single lines of evidence lead to incorrect species delimitation or assignment of individuals to species (e.g. cryptic, morphological species and paraphyletic, hybridizing species). Species of the Australian Gehyra gecko radiation have historically proven difficult to delimit due the group's uniform, almost continent-wide geographic distribution and conservative morphology, contrasting high chromosomal and genetic diversity. Using an integrated approach to species delimitation taking advantage of morphological, geographic distributional and multi-locus genetic data, we investigate the diversity within three Gehyra species from the Australian arid zone. Our results show that these species represent eight distinct phylogenetic lineages, which display different patterns of morphological distinction and reproductive isolation. Using a recently developed Bayesian species delimitation method, we also find different levels of support for putative species dependent on priors for population size and timing of diversification assumed. Our results show that the current taxonomy does not adequately account for the diversity of the group. Discrepancies between lines of evidence indicate that diversification of the group is recent and ongoing...

Delimitação territorial de municípios: proposta metodológica; Territorial delimitation of municipalities: methodological proposal

Cavellani, Caio Lourencini
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 20/07/2015 PT
Relevância na Pesquisa
36.93%
O presente trabalho tem, como objetivo principal, apresentar uma proposta metodológica para a delimitação territorial de municípios. A questão fronteiriça, aparentemente irrelevante em um mundo cada vez mais integrado, classificado por muitos como um mundo sem fronteiras, mostra-se, na verdade, cada vez mais presente, dentro de uma fragmentação permanente do espaço geográfico em diversas unidades políticas. Dentro disto, os limites territoriais internos, primordialmente os de caráter municipal, apresentam grande importância na vida cotidiana de todos os indivíduos. São estas linhas que determinam a localização de eleitores, a implantação de escolas, atendimentos em postos de saúde, entregas de correspondências, implantação de linhas telefônicas, cadastramentos pra fins escolares, recolhimento de lixo, pesquisa para censos demográficos, abastecimento de água e luz, melhoramentos em vias de acesso, entre outros. Dada tamanha importância, espera-se que os mesmos tenham suas definições baseadas em critérios concretos e coerentes. A análise dos limites municipais brasileiros demonstra, entretanto, uma situação distante da ideal. Enquanto parâmetros populacionais, econômicos e eleitorais são discutidos como requisitos mínimos para a criação de municípios...

The decision on the maritime boundary between Chile and Perú : international law revisited

Infante Caffi, María Teresa
Fonte: University of the West Indies Publicador: University of the West Indies
Tipo: Artículo de revista
EN
Relevância na Pesquisa
27.08%
In2014,the International Court of Justice rendered its judgment on matters submitted to it by Peru against Chile in 2008. Peru contended that there was a bilateral legal controversy over the delimitation of the maritime spaces between both countries. Chile argued for the validity of long-­‐standing treaties between the parties, which had been enforced and implemented in law and in practice. Was it a classical delimitation controversy from one part, or a reinterpretation of existing agreements from another perspective? The judgment acknowledged the existing maritime delimitation, while jointly declaring that the extent of the parallel line reaches 80 nautical miles.

Desarrollo de un filtro temático para la delimitación bibliométrica de un área interdisciplinar: el caso de Ciencias del Mar; Development of a thematic filter for the bibliometric delimitation on interdisciplinary area: the case of Marine Science

Costas, Rodrigo; Bordons, María
Fonte: Consejo Superior de Investigaciones Científicas (España) Publicador: Consejo Superior de Investigaciones Científicas (España)
Tipo: Artículo Formato: 52349 bytes; application/pdf
SPA
Relevância na Pesquisa
37.31%
[ES] En esta nota metodológica se analiza la precisión y exhaustividad de un filtro temático diseñado para delimitar el área de Ciencias del Mar a través de revistas especializadas y palabras clave, y se compara su eficacia con una delimitación basada sólo en revistas. El estudio analiza la producción científica española en Ciencias del Mar obtenida del SCI, SSCI & AHCI durante los años 1994-2004. La estrategia basada en revistas obtiene una alta precisión (96%) pero baja exhaustividad en la delimitación (próxima al 30%). El filtro mixto presenta una menor precisión (69%) pero una mayor exhaustividad (alrededor del 75%). La delimitación basada en revistas ofrece una imagen incompleta del área e ignora contribuciones que generan alto impacto publicadas en revistas de otras disciplinas. Se pone de manifiesto el interés de desarrollar filtros temáticos más elaborados y el importante papel de los expertos para obtener un equilibrio entre precisión y exhaustividad.; [EN] In this methodological note, the recall and precision of a mixed thematic filter developed for the delimitation of the Marine Science area by means of specialised journals and keywords is analysed, and its efficiency is compared with a delimitation based only on scientific journals. The scientific production of Marine Science in Spain during 1994-2004 as covered by SCI...

Cubic spline population density functions and subcentre delimitation. The case of Barcelona

Muñiz, Iván; Galindo, Anna; García López, Miquel-Àngel
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: Trabalho em Andamento Formato: application/pdf
Publicado em //2006 ENG
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The presence of subcentres cannot be captured by an exponential function. Cubic spline functions seem more appropriate to depict the polycentricity pattern of modern urban systems. Using data from Barcelona Metropolitan Region, two possible population subcentre delimitation procedures are discussed. One, taking an estimated derivative equal to zero, the other, a density gradient equal to zero. It is argued that, in using a cubic spline function, a delimitation strategy based on derivatives is more appropriate than one based on gradients because the estimated density can be negative in sections with very low densities and few observations, leading to sudden changes in estimated gradients. It is also argued that using as a criteria for subcentre delimitation a second derivative with value zero allow us to capture a more restricted subcentre area than using as a criteria a first derivative zero. This methodology can also be used for intermediate ring delimitation.