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1.
BMC Ecol Evol ; 24(1): 71, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38811886

RESUMO

Home range is a fundamental characteristic of an animal natural history. The study of home range provides information on the sites where organisms forage for food, find shelter, or locate mates. Home range size and shape can change throughout the lifespan of an organism, during the year, or across seasons, driven by resource availability and the basic needs for each organism. For freshwater and semi-aquatic turtles, home range is greatly affected by water availability, humidity, and temperature throughout the year, nevertheless demographic factors such age and sex are also important determinants of home range size. In this study we estimated home range and dispersal movements for Kinosternon creaseri, Terrapene yucatana, and Rhinoclemmys areolata in a semi-tropical dry forest in central Yucatán. For a two-year period, turtles were surveyed using hoop traps and visual encounters. Twenty-one individuals (5-8 per species) were equipped with radio transmitters to track them across the landscape. Distances between relocations and home range were compared across species seasons, sex, and interactions of these variables. Monthly average movements were positively correlated with rain in the three species studied. Home range of R. areolata was larger than those of K. creaseri and T. yucatana. Home range of the three studied species were larger during the wet season. Home range overlap index within same species individuals was higher during the rainy than dry season, but overall overlap is low between and within species.


Assuntos
Comportamento de Retorno ao Território Vital , Estações do Ano , Tartarugas , Tartarugas/fisiologia , Animais , Feminino , Masculino , México , Comportamento de Retorno ao Território Vital/fisiologia
2.
Rev. chil. nutr ; 50(4)ago. 2023.
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1515197

RESUMO

There is an increasing interest in having validated instruments that can classify food environments due to their influence on eating behavior and nutritional status. In Chile, it is not known how people perceive food environments and only a few studies have adapted instruments to the Chilean context, all of which use objective measures. The aim of this study is to present the adaptation and validation of the Perceived Nutrition Environment Measures Survey (NEMS-P-Ch) for Chile using a cross-sectional, non-probability study. First, the NEMS-P was adapted in 3 stages: cultural translation and adaptation, expert judgment (focus groups), and cognitive interviews with a population similar to the target audience. Then, the adapted questionnaire (NEMS-P for Chile, NEMS-P-Ch) was tested on people responsible for buying food in their homes in the Metropolitan Region, Chile, for statistical validation. After 200 people completed the questionnaire a final version of the NEMS-P-Ch was generated with 48 questions and seven sections that measure food environments: home, food supply, restaurants and street. NEMS-P-Ch had acceptable reliability in more than half of the questions analyzed, with Cronbach's alpha values between 0.44 and 0.82. Acceptable values were also obtained for most of the questions when the consistency of the instrument was evaluated after applying it for the second time (n= 167). The NEMS-P-Ch adapted to the Chilean context showed acceptable validity and reliability. Having instruments adapted and validated to the national reality will promote their use and adaptation in other countries of the region and thus deepen the study of food environments in various territories and populations.


El creciente interés por contar con instrumentos validados que clasifiquen los ambientes alimentarios se debe a la influencia que estos tienen en la conducta alimentaria y el estado nutricional. En Chile, se desconoce cómo las personas perciben los ambientes alimentarios y son pocos los estudios que han adaptado instrumentos al contexto chileno, todos utilizando medidas objetivas. En este estudio se presenta la adaptación y validación para Chile de la Encuesta de Medición del Entorno Nutricional Percibido (NEMS-P-Ch). Estudio transversal, no probabilístico. Inicialmente, NEMS-P fue adaptado siguiendo 3 etapas: traducción y adaptación cultural, juicio de expertos (grupos focales) y entrevistas cognitivas con población similar a la audiencia objetivo. Luego, el cuestionario adaptado (NEMS-P-Ch) fue testeado en personas responsables de la compra de alimentos del hogar, Región Metropolitana, Chile, para finalmente validarlo estadísticamente. Tras su aplicación a 200 personas, se generó la última versión de NEMS-PCh, instrumento con 48 preguntas y 7 secciones que mide los ambientes alimentarios: doméstico, de abastecimiento, restauración y vía pública. NEMS-P-Ch mostró una confiabilidad aceptable en más de la mitad de las preguntas analizadas, con valores alfa de Cronbach entre 0,44 y 0,82. También se obtuvieron valores aceptables en la mayoría de las preguntas cuando se evaluó su consistencia al aplicarlo por segunda vez (n= 167). NEMS-P-Ch adaptado al contexto chileno mostró una validez y confiabilidad aceptables. Contar con instrumentos validados a la realidad nacional promoverá su uso, su adaptación en otros países de la región y la profundización del estudio de los ambientes alimentarios en diversos territorios y poblaciones.

3.
BMC Ecol Evol ; 22(1): 74, 2022 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-35672668

RESUMO

BACKGROUND: Diet is a key component of a species ecological niche and plays critical roles in guiding the trajectories of evolutionary change. Previous studies suggest that dietary evolution can influence the rates and patterns of species diversification, with omnivorous (animal and plant, 'generalist') diets slowing down diversification compared to more restricted ('specialist') herbivorous and carnivorous diets. This hypothesis, here termed the "dietary macroevolutionary sink" hypothesis (DMS), predicts that transitions to omnivorous diets occur at higher rates than into any specialist diet, and omnivores are expected to have the lowest diversification rates, causing an evolutionary sink into a single type of diet. However, evidence for the DMS hypothesis remains conflicting. Here, we present the first test of the DMS hypothesis in a lineage of ectothermic tetrapods-the prolific Liolaemidae lizard radiation from South America. RESULTS: Ancestral reconstructions suggest that the stem ancestor was probably insectivorous. The best supported trait model is a diet-dependent speciation rate, with independent extinction rates. Herbivory has the highest net diversification rate, omnivory ranks second, and insectivory has the lowest. The extinction rate is the same for all three diet types and is much lower than the speciation rates. The highest transition rate was from omnivory to insectivory, and the lowest transition rates were between insectivory and herbivory. CONCLUSIONS: Our findings challenge the core prediction of the DMS hypothesis that generalist diets represent an 'evolutionary sink'. Interestingly, liolaemid lizards have rapidly and successfully proliferated across some of the world's coldest climates (at high elevations and latitudes), where species have evolved mixed arthropod-plant (omnivore) or predominantly herbivore diets. This longstanding observation is consistent with the higher net diversification rates found in both herbivory and omnivory. Collectively, just like the evolution of viviparity has been regarded as a 'key adaptation' during the liolaemid radiation across cold climates, our findings suggest that transitions from insectivory to herbivory (bridged by omnivory) are likely to have played a role as an additional key adaptation underlying the exceptional diversification of these reptiles across extreme climates.


Assuntos
Lagartos , Animais , Dieta/veterinária , Ecossistema , Herbivoria , Filogenia
4.
Ann Bot ; 127(2): 175-189, 2021 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-32880645

RESUMO

BACKGROUND AND AIMS: There is a paucity of empirical research and a lack of predictive models concerning the interplay between spatial scale and disturbance as they affect the structure and assembly of plant communities. We proposed and tested a trait dispersion-based conceptual model hypothesizing that disturbance reinforces assembly processes differentially across spatial scales. Disturbance would reinforce functional divergence at the small scale (neighbourhood), would not affect functional dispersion at the intermediate scale (patch) and would reinforce functional convergence at the large scale (site). We also evaluated functional and species richness of native and exotic plants to infer underlying processes. Native and exotic species richness were expected to increase and decrease with disturbance, respectively, at the neighbourhood scale, and to show similar associations with disturbance at the patch (concave) and site (negative) scales. METHODS: In an arid shrubland, we estimated species richness and functional dispersion and richness within 1 m2 quadrats (neighbourhood) nested within 100 m2 plots (patch) along a small-scale natural disturbance gradient caused by an endemic fossorial rodent. Data for the site scale (2500 m2 plots) were taken from a previous study. We also tested the conceptual model through a quantitative literature review and a meta-analysis. KEY RESULTS: As spatial scale increased, disturbance sequentially promoted functional divergence, random trait dispersion and functional convergence. Functional richness was unaffected by disturbance across spatial scales. Disturbance favoured natives over exotics at the neighbourhood scale, while both decreased under high disturbance at the patch and site scales. CONCLUSIONS: The results supported the hypothesis that disturbance reinforces assembly processes differentially across scales and hampers plant invasion. The quantitative literature review and the meta-analysis supported most of the model predictions.


Assuntos
Biodiversidade , Ecossistema , Animais , Modelos Teóricos , Plantas , Roedores
5.
Front Microbiol ; 11: 607693, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33519754

RESUMO

Codon usage bias (the preferential use of certain synonymous codons (optimal) over others is found at the organism level (intergenomic) within specific genomes (intragenomic) and even in certain genes. Whether it is the result of genetic drift due to GC/AT content and/or natural selection is a topic of intense debate. Preferential codons are mostly found in genes encoding highly-expressed proteins, while lowly-expressed proteins usually contain a high proportion of rare (lowly-represented) codons. While optimal codons are decoded by highly expressed tRNAs, rare codons are usually decoded by lowly-represented tRNAs. Whether rare codons play a role in controlling the expression of lowly- or temporarily-expressed proteins is an open question. In this work we approached this question using two strategies, either by replacing rare glycine codons with optimal counterparts in the gene that encodes the cell cycle protein Cdc13, or by overexpression the tRNA Gly that decodes rare codons from the fission yeast, Schizosaccharomyces pombe. While the replacement of synonymous codons severely affected cell growth, increasing tRNA levels affected the aggregation status of Cdc13 and cell division. These lead us to think that rare codons in lowly-expressed cyclin proteins are crucial for cell division, and that the overexpression of tRNA that decodes rare codons affects the expression of proteins containing these rare codons. These codons may be the result of the natural selection of codons in genes that encode lowly-expressed proteins.

6.
Rev. colomb. radiol ; 31(3): 5408-5410, sept. 2020. ilus, graf
Artigo em Inglês, Espanhol | LILACS | ID: biblio-1343670

RESUMO

El edema pulmonar de las alturas es una condición clínica que se desarrolla en individuos que han estado en regiones a nivel del mar y que posteriormente ascienden rápidamente a altitudes por encima de los 2500 metros. Se describe el caso de un paciente de 26 años con cuadro clínico y hallazgos radiológicos típicos de esta patología, en quién inicialmente se sospechó infección por coronavirus dada la sintomatología y el contexto de pandemia actual


High altitude pulmonary edema is a clinical condition that develops in individuals who have been in regions at sea level and who subsequently have a rapid ascent to altitudes above 2500 meters. We present the case of a 26-year-old male with clinical presentation and radiological findings typical of this entity, in whom coronavirus infection was initially suspected given the signs and symptoms in context of the current pandemic


Assuntos
Adulto , Edema Pulmonar , Infecções por Coronavirus , Doença da Altitude , COVID-19
7.
Comput Struct Biotechnol J ; 17: 746-756, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31303979

RESUMO

Mobile Genetic Elements (MGEs) are mosaics of functional gene modules of diverse evolutionary origin and are generally divergent from the hosts´ genetic background. Existing biases in base composition and codon usage of these elements` genes impose transcription and translation limitations that may affect the physical and regulatory integration of MGEs in new hosts. Stable appropriation of the foreign DNA depends on a number of host factors among which are the Nucleoid-Associated Proteins (NAPs). These small, basic, highly abundant proteins bind and bend DNA, altering its topology and folding, thereby affecting all known essential DNA metabolism related processes. Both chromosomally- (endogenous) and MGE- (foreign) encoded NAPs have been shown to exist in bacteria. While the role of host-encoded NAPs in xenogeneic silencing of both episomal (plasmids) and integrative MGEs (pathogenicity islands and prophages) is well acknowledged, less is known about the role of MGE-encoded NAPs in the foreign elements biology or their influence on the host's chromosome expression dynamics. Here we review existing literature on the topic, present examples on the positive and negative effects that endogenous and foreign NAPs exert on global transcriptional gene expression, MGE integrative and excisive recombination dynamics, persistence and transfer to suitable hosts and discuss the nature and relevance of synergistic and antagonizing higher order interactions between diverse types of NAPs.

8.
Front Microbiol ; 10: 30, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30804894

RESUMO

The dispersal of mobile genetic elements and their gene cargo relies on type IV secretion systems (T4SS). In this work the ICEAfe1 Tra-type T4SS nanomachine, encoded in the publicly available genome of Acidithiobacillus ferrooxidans ATCC 23270TY, was characterized in terms of its organization, conservation, expression and mating bridge formation. Twenty-one conjugative genes grouped in four genetic clusters encode the ICEAfe1 T4SS, containing all the indispensable functions for the formation and stabilization of the pili and for DNA processing. The clusters' organization resembles that of other mobile genetic elements (such as plasmids and integrative and conjugative elements-ICEs). Sequence conservation, genetic organization and distribution of the tra system in the genomes of other sequenced Acidithiobacillus spp. suggests that the ICEAfe1 T4SS could mediate the lateral gene transfer between related bacteria. All ICEAfe1 T4SS genes are transcriptionally active and expressed from four independent operons. The transcriptional levels of selected marker genes increase in response to Mitomycin C treatment, a DNA damage elicitor that has acknowledged stimulatory effects on excision rates and gene expression of other ICEs, including ICEAfe1. Using a tailor-made pilin-antiserum against ICEAfe1 T4SS TraA pilin and epifluorescence microscopy, the presence of the conjugative pili on the cell surface of A. ferrooxidans could be demonstrated. Additionally, immunodetection assays, by immunogold, allowed the identification of pili-like extracellular structures. Together, the results obtained in this work demonstrate that the ICEAfe1 T4SS is phylogenetically conserved within the taxon, is expressed at mRNA and protein levels in vivo in the A. ferrooxidans type strain, and produces a pili-like structure of extracellular and intercellular localization in this model acidophile, supporting its functionality. Additional efforts will be required to prove conjugation of the ICEAfe1 or parts of this element through the cognate T4SS.

9.
Rev. colomb. radiol ; 30(3): 5194-5198, Sept. 2019. ilus, graf
Artigo em Inglês, Espanhol | LILACS, COLNAL | ID: biblio-1290943

RESUMO

Los informes estructurados contextualizados cumplen tres características fundamentales: tienen una estructura uniforme que responde una pregunta clínica, son el producto de listas de chequeo estandarizadas o de árboles de conocimiento previamente concertados con equipos clínicos multidisciplinarios y se construyen a partir de cuadros de selección de atributos incorporados en los sistemas de informe electrónicos, adicionalmente, el atributo contextualizado hace referencia a la capacidad del informe de responder las preguntas clínicas de la situación actual del paciente, otorgando información relevante de forma concisa y clara a los médicos tratantes. Dentro de las principales ventajas de migrar hacia el informe estructurado se encuentran la uniformidad y la alta calidad del informe, el aumento en la concordancia intra e interobservador, así como la reducción de las tasas de error diagnóstico y una mejora significativa en la comunicación con los médicos tratantes. Se presenta una revisión temática que abarca las características esenciales del informe estructurado contextualizado, los argumentos a favor y en contra de este, los pasos recomendados para su implementación y las oportunidades de mejora hacia el futuro.


Structured reporting in radiology fulfill three fundamental characteristics: they have a uniform structure that answers a clinical question, they are the product of standardized checklists or of knowledge trees previously arranged with multidisciplinary clinical teams, and they are incorporated in option-selection boxes available in electronic reporting systems. Among the main advantages of migrating towards structured reporting are the uniformity and high quality of the report, the increase in intra and interobserver concordance, as well as the reduction of the diagnostic error rates and a significant improvement in communication with the clinical practitioner. This thematic review covers the essential characteristics of the structured report, the arguments for and against it, the recommended steps for its implementation, and the future opportunities for improvement.


Assuntos
Humanos , Sistemas de Informação em Radiologia , Informática Médica , Diagnóstico por Computador
10.
PeerJ ; 5: e3182, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28462019

RESUMO

In birds, the environmental variables and intrinsic characteristics of the nest have important fitness consequences through its influence on the selection of nesting sites. However, the extent to which these variables interact with variables that operate at the landscape scale, and whether there is a hierarchy among the different scales that influences nest-site selection, is unknown. This interaction could be crucial in burrowing birds, which depend heavily on the availability of suitable nesting locations. One representative of this group is the burrowing parrot, Cyanoliseus patagonus that breeds on specific ravines and forms large breeding colonies. At a particular site, breeding aggregations require the concentration of adequate environmental elements for cavity nesting, which are provided by within ravine characteristics. Therefore, intrinsic ravine characteristics should be more important in determining nest site selection compared to landscape level characteristics. Here, we assess this hypothesis by comparing the importance of ravine characteristics operating at different scales on nest-site selection and their interrelation with reproductive success. We quantified 12 characteristics of 105 ravines in their reproductive habitat. For each ravine we quantified morphological variables, distance to resources and disturbance as well as nest number and egg production in order to compare selected and non-selected ravines and determine the interrelationship among variables in explaining ravine differences. In addition, the number of nests and egg production for each reproductive ravine was related to ravine characteristics to assess their relation to reproductive success. We found significant differences between non-reproductive and reproductive ravines in both intrinsic and extrinsic characteristics. The multidimensional environmental gradient of variation between ravines, however, shows that differences are mainly related to intrinsic morphological characteristics followed by extrinsic variables associated to human disturbance. Likewise, within reproductive ravines, intrinsic characteristics are more strongly related to the number of nests. The probability of producing eggs, however, was related only to distance to roads and human settlements. Patterns suggest that C. patagonus mainly selects nesting sites based on intrinsic morphological characteristics of ravines. Scale differences in the importance of ravine characteristics could be a consequence of the particular orography of the breeding habitat. The arrangement of resources is associated to the location of the gullies rather than to individual ravines, determining the spatial availability and disposition of resources and disturbances. Thus, nest selection is influenced by intrinsic characteristics that maximize the fitness of individuals. Scaling in nest-selection is discussed under an optimality approach that partitions patch selection based on foraging theory.

11.
Ann Bot ; 119(4): 659-670, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28087661

RESUMO

Background and Aims: Disturbance often drives plant invasion and may modify community assembly. However, little is known about how these modifications of community patterns occur in terms of taxonomic, functional and phylogenetic structure. This study evaluated in an arid shrubland the influence of disturbance by an endemic rodent on community functional divergence and phylogenetic structure as well as on plant invasion. It was expected that disturbance would operate as a habitat filter favouring exotic species with short life cycles. Methods: Sixteen plots were sampled along a disturbance gradient caused by the endemic fossorial rodent Spalacopus cyanus , measuring community parameters and estimating functional divergence for life history traits (functional dispersion index) and the relative contribution to functional divergence of exotic and native species. The phylogenetic signal (Pagel's lambda) and phylogenetic community structure (mean phylogenetic distance and mean nearest taxon phylogenetic distance) were also estimated. The use of a continuous approach to the disturbance gradient allowed the identification of non-linear relationships between disturbance and community parameters. Key Results: The relationship between disturbance and both species richness and abundance was positive for exotic species and negative for native species. Disturbance modified community composition, and exotic species were associated with more disturbed sites. Disturbance increased trait convergence, which resulted in phylogenetic clustering because traits showed a significant phylogenetic signal. The relative contribution of exotic species to functional divergence increased, while that of natives decreased, with disturbance. Exotic and native species were not phylogenetically distinct. Conclusions: Disturbance by rodents in this arid shrubland constitutes a habitat filter over phylogeny-dependent life history traits, leading to phylogenetic clustering, and drives invasion by favouring species with short life cycles. Results can be explained by high phenotypic and phylogenetic resemblance between exotic and native species. The use of continuous gradients when studying the effects of disturbance on community assembly is advocated.


Assuntos
Ecossistema , Plantas , Roedores , Animais , Biodiversidade , Clima Desértico , Espécies Introduzidas , Filogenia , Dinâmica Populacional
12.
Evolution ; 70(12): 2736-2745, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27669683

RESUMO

The climbing habit is a key innovation in plants: climbing taxa have higher species richness than nonclimbing sister groups. We evaluated the hypothesis that climbing plant species show greater among-population genetic differentiation than nonclimber species. We compared the among-population genetic distance in woody climbers (eight species, 30 populations) and trees (seven species, 29 populations) coexisting in nine communities in a temperate rainforest. We also compared within-population genetic diversity in co-occurring woody climbers and trees in two communities. Mean genetic distance between populations of climbers was twice that of trees. Isolation by distance (increase in genetic distance with geographic distance) was greater for climbers. Climbers and trees showed similar within-population genetic diversity. Our longevity estimate suggested that climbers had shorter generation times, while other biological features often associated with diversification (dispersal and pollination syndromes, mating system, size, and metabolic rate) did not show significant differences between groups. We hypothesize that the greater population differentiation in climbers could result from greater evolutionary responses to local selection acting on initially higher within-population genetic diversity, which could be driven by neutral processes associated with shorter generation times. Increased population genetic differentiation could be incorporated as another line of evidence when testing for key innovations.


Assuntos
Evolução Biológica , Variação Genética , Magnoliopsida/anatomia & histologia , Fenótipo , Chile , Magnoliopsida/genética , Especificidade da Espécie , Árvores/anatomia & histologia , Árvores/genética
14.
PLoS One ; 9(6): e99871, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24914958

RESUMO

The climbing habit is an evolutionary key innovation in plants because it is associated with enhanced clade diversification. We tested whether patterns of species divergence and variation of three ecophysiological traits that are fundamental for plant adaptation to light environments (maximum photosynthetic rate [A(max)], dark respiration rate [R(d)], and specific leaf area [SLA]) are consistent with this key innovation. Using data reported from four tropical forests and three temperate forests, we compared phylogenetic distance among species as well as the evolutionary rate, phylogenetic distance and phylogenetic signal of those traits in lianas and trees. Estimates of evolutionary rates showed that R(d) evolved faster in lianas, while SLA evolved faster in trees. The mean phylogenetic distance was 1.2 times greater among liana species than among tree species. Likewise, estimates of phylogenetic distance indicated that lianas were less related than by chance alone (phylogenetic evenness across 63 species), and trees were more related than expected by chance (phylogenetic clustering across 71 species). Lianas showed evenness for R(d), while trees showed phylogenetic clustering for this trait. In contrast, for SLA, lianas exhibited phylogenetic clustering and trees showed phylogenetic evenness. Lianas and trees showed patterns of ecophysiological trait variation among species that were independent of phylogenetic relatedness. We found support for the expected pattern of greater species divergence in lianas, but did not find consistent patterns regarding ecophysiological trait evolution and divergence. R(d) followed the species-level pattern, i.e., greater divergence/evolution in lianas compared to trees, while the opposite occurred for SLA and no pattern was detected for A(max). R(d) may have driven lianas' divergence across forest environments, and might contribute to diversification in climber clades.


Assuntos
Filogenia , Característica Quantitativa Herdável , Árvores/fisiologia , Intervalos de Confiança , Folhas de Planta/anatomia & histologia , Especificidade da Espécie
15.
PLoS One ; 8(3): e58518, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23505527

RESUMO

The stress gradient hypothesis posits that facilitation and stress are positively correlated. The hump-shaped hypothesis, on the contrary, proposes that facilitation is greater at intermediate stress levels. The relationship between facilitation and environmental stress is commonly studied at small spatial scales and/or considering few species; thus, the implications of facilitation at a community level remain poorly understood. Here, we analyzed local co-occurrence patterns of all plant species at 25 sites within the subtropical Andes to evaluate the role of facilitation and competition as drivers of community structure. We considered a wide latitudinal gradient (19-26°S) that incorporates great variation in aridity. No previous studies have attempted to study these patterns across such a broad scale in warm deserts. Each locality was sampled at two scales (quadrat and patch), and co-occurrence was analyzed via null models. Furthermore, we tested for a relationship between plant co-occurrences and environmental aridity. Resulting patterns depended on life form. When all species were considered, negative associations were found, indicating competition. Woody/cactus life forms tended to be associated across communities, suggesting that there is facilitation between these life forms. Additionally, and unlike previous studies, we found positive associations among shrubs. The strength of the association between woody species changed non-monotonically with aridity. Herbs showed an inverted hump-shaped relationship, albeit ranging mostly among neutral values. Independent of the association type exhibited by different life forms, our community level results do not support current stress gradient hypotheses.


Assuntos
Meio Ambiente , Plantas , Estresse Fisiológico , Algoritmos , Argentina , Biodiversidade , Bolívia , Clima , Ecossistema , Geografia , Modelos Teóricos
16.
Zoolog Sci ; 29(1): 60-5, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22233498

RESUMO

Optimal offspring size theory states that natural selection should balance reproductive output by optimizing between offspring size and offspring number. If a species has evolved an optimal offspring size, the fitness of larger females should be increased by simply producing more offspring of an optimum size. In contrast, when offspring size is not optimized, the morphological constraint hypothesis may apply, and in this case, maternal fitness is increased by producing the greatest number of the largest offspring that mothers are physically capable of producing. We used a log-log allometric regression approach on clutch size, egg size, and body size data to test the application of optimal offspring size theory and the morphological constraint hypothesis in the Mexican mud turtle (Kinosternon integrum) in southern Mexico. Our results indicate that this turtle seems to follow the morphological constraint hypothesis when all data are analyzed together, but when data are divided between small (< 140 mm plastron length) and large females (> 140 mm plastron length), optimal offspring (egg) size theory was supported only in large females, while the morphological constraint hypothesis was supported in small females. Our results thus indicate that K. integrum females may increase their fitness in two different, size-dependent ways as they grow from size at sexual maturity to maximum body size.


Assuntos
Tamanho Corporal/fisiologia , Tartarugas/crescimento & desenvolvimento , Tartarugas/fisiologia , Animais , Evolução Biológica , Demografia , Feminino , Aptidão Genética , México , Óvulo/citologia , Seleção Genética
17.
Rev Salud Publica (Bogota) ; 13(2): 298-307, 2011 Apr.
Artigo em Espanhol | MEDLINE | ID: mdl-22030887

RESUMO

OBJECTIVE: Analysing scientific production in the area of infectious diseases in Colombia, 2000-2009. MATERIAL AND METHODS: A literature search was made in category A journals in Colciencias' Publindex. The journals were: Biomédica, Revista de Salud Pública (Universidad Nacional), Colombia Médica, Ciencias Pecuarias, Latreia, MVZ Córdoba, Revista de Medicina (Universidad Nacional) and Infectio. RESULTS: 2,963 publications were found; 2,744 (92.6 %) were national publications and 219 (7.4 %) were foreign submissions, of which 863 (29.1 %) were on infectious diseases, 817 (94.7 %) having been submitted nationally and 46 (5.3 %) submitted by foreigners. National publications on infectious diseases were distributed as follows: 268 on parasitology (32.8 %), bacteriology and antimicrobial resistance accounted for 267 (32.7 %), virology 210 (25.7 %), mycology 46 (5.6 %) and other items related to infectious diseases accounted for 26 (3.2 %). The regional distribution of publications was: Cundinamarca 239 (29.3 %), Antioquia 211 (25.8 %), Valle del Cauca 60 (7.3 %), Caribbean coast 52 (6.4 %), the Santanders 38 (4.6 %), the coffee-growing area 31 (3.8 %) and southern Colombia 13 (1.6 %). CONCLUSIONS: This is the first study which has analysed publications on infectious diseases in Colombia. There was regional imbalance concerning bibliometric indicators in Colombia; public universities accounted for 90 % of research being carried out in the area of infectious diseases in Colombia.


Assuntos
Bibliometria , Infectologia , Microbiologia , Parasitologia , Academias e Institutos/estatística & dados numéricos , Ensaios Clínicos como Assunto/estatística & dados numéricos , Colômbia , Publicações Periódicas como Assunto/estatística & dados numéricos , Estudos Retrospectivos , Universidades/estatística & dados numéricos
18.
Am J Bot ; 98(8): 1317-26, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21821592

RESUMO

PREMISE OF THE STUDY: Seed dispersal is a key process for plant regeneration in tropical areas. Differences in disperser behavior result in a nonrandom distribution of seeds among habitats. Patterns of seed dispersal may cascade through the entire recruitment phase or uncoupling between developmental stages may occur such that patterns of seed dispersal are discordant with patterns of recruitment. Here, we analyzed how habitat and interannual variability affect the recruitment dynamics of a bird-dispersed tree, Guettarda viburnoides (RUB.). METHODS: Over 3 years, we determined the habitats where seeds of G. viburnoides are dispersed, and we experimentally quantified postdispersal seed predation, seedling emergence, and survival in four habitats of a forest-savanna mosaic in Bolivia. KEY RESULTS: Habitat affected seed dispersal, seed predation, and seedling emergence. The strength of postdispersal processes, however, varied between years and no consistent within-habitat pattern emerged. Uncoupling among different life-stages was observed across habitats, and spatial concordance was found between seed rain and sapling recruitment patterns. CONCLUSIONS: Habitat can affect seed dispersal, postdispersal processes and the recruitment dynamics of a Neotropical tree in a heterogeneous landscape. Additionally, our results show interannual variability in the strength of postdispersal processes, which leads to shifts in habitat suitability between years. Therefore, to better understand the role of site suitability for recruitment, we need to explicitly consider not only variation in habitat-specificity for dispersal and postdispersal processes, but also how this variation can shift under different environmental conditions-that is, the context dependence of suitability.


Assuntos
Rubiaceae/fisiologia , Dispersão de Sementes , Sementes/fisiologia , Árvores , Animais , Formigas/fisiologia , Aves/fisiologia , Bolívia , Ecossistema , Germinação , Herbivoria , Plântula/fisiologia , Especificidade da Espécie , Clima Tropical
19.
Rev. salud pública ; Rev. salud pública;13(2): 298-307, abr. 2011. ilus, tab
Artigo em Espanhol | LILACS | ID: lil-602876

RESUMO

Objetivo Analizar la producción científica en el área de las enfermedades infecciosas en Colombia durante el periodo de 2000-2009. Material y métodos Se realizó una búsqueda bibliográfica en las revistas de categoría A del Publindex de Colciencias. Las revistas fueron: Biomédica, Salud Pública de la Universidad Nacional, Colombia Médica, Ciencias Pecuarias, Iatreia, MVZ Córdoba, Medicina de la Universidad Nacional e Infectio. Resultados Se encontraron un total de 2 963 publicaciones, 2 744 (92,6 por ciento) publicaciones nacionales y 219 (7,4 por ciento) publicaciones de origen extranjero; De las cuales 863 (29,1 por ciento) fueron sobre enfermedades infecciosas, 817 (94,7 por ciento) publicaciones de origen nacional y 46 (5,3 por ciento) publicaciones extranjeras. Las publicaciones nacionales en enfermedades infecciosas, se distribuyeron de la siguiente manera: parasitología 268 (32,8 por ciento), bacteriología y resistencia antimicrobiana 267 (32,7 por ciento), virología 210 (25,7 por ciento), micología 46 (5,6 por ciento) y otros artículos relacionados con las enfermedades infecciosas 26 (3,2 por ciento). La distribución regional de las publicaciones fue: Cundinamarca 239 (29,3 por ciento), Antioquia 211 (25,8 por ciento) Valle del Cauca 60 (7,3 por ciento), Costa Caribe 52 (6,4 por ciento), Santanderes 38 (4,6 por ciento), eje cafetero 31 (3,8 por ciento) y sur del país 13 (1,6 por ciento). Conclusiones Este es el primer trabajo que analiza las publicaciones en enfermedades infecciosas en Colombia. Existe un desequilibrio regional en los indicadores bibliométricos en Colombia. La universidad pública soporta el 90 por ciento de la investigación del área de infectología en Colombia.


Objective Analysing scientific production in the area of infectious diseases in Colombia, 2000-2009. Material and methods A literature search was made in category A journals in Colciencias' Publindex. The journals were: Biomédica, Revista de Salud Pública (Universidad Nacional), Colombia Médica, Ciencias Pecuarias, Latreia, MVZ Córdoba, Revista de Medicina (Universidad Nacional) and Infectio. Results 2,963 publications were found; 2,744 (92.6 percent) were national publications and 219 (7.4 percent) were foreign submissions, of which 863 (29.1 percent) were on infectious diseases, 817 (94.7 percent) having been submitted nationally and 46 (5.3 percent) submitted by foreigners. National publications on infectious diseases were distributed as follows: 268 on parasitology (32.8 percent), bacteriology and antimicrobial resistance accounted for 267 (32.7 percent), virology 210 (25.7 percent), mycology 46 (5.6 percent) and other items related to infectious diseases accounted for 26 (3.2 percent). The regional distribution of publications was: Cundinamarca 239 (29.3 percent), Antioquia 211 (25.8 percent), Valle del Cauca 60 (7.3 percent), Caribbean coast 52 (6.4 percent), the Santanders 38 (4.6 percent), the coffee-growing area 31 (3.8 percent) and southern Colombia 13 (1.6 percent). Conclusions This is the first study which has analysed publications on infectious diseases in Colombia. There was regional imbalance concerning bibliometric indicators in Colombia; public universities accounted for 90 percent of research being carried out in the area of infectious diseases in Colombia.


Assuntos
Bibliometria , Infectologia , Microbiologia , Parasitologia , Academias e Institutos/estatística & dados numéricos , Ensaios Clínicos como Assunto/estatística & dados numéricos , Colômbia , Publicações Periódicas como Assunto/estatística & dados numéricos , Estudos Retrospectivos , Universidades/estatística & dados numéricos
20.
Chiropt. neotrop. ; 16(2): 762-768, 2010.
Artigo em Português | VETINDEX | ID: vti-464670

RESUMO

Even though it is abundant throughout its distribution range, Myotis levis (I. Geoffroy, 1824) is a poorly-known species. Field efforts were carried out in the present study to better understand some aspects of this species natural history on the shelter (house shelter). Information was obtained through captures using mist-nets positioned at the exit of an artificial shelter, during three consecutive nights, as well as incursions into the shelter, with the goal of estimating the number of individuals in the colony. The study area is located within the Palmas Grasslands, Palmas Municipality, southern Paraná (26º3459S and 51º3616W). Captures resulted in 186 individuals, being 96 adults and 90 juveniles. The colony size was estimated in circa of 12 000 and 15 000 individuals. Based on the structure of the population, the presence of reproductive females, juveniles, and infants, a nursery colony was characterized. In addition to aspects of their reproductive biology, this study deals also morphometric and coloration variations, as well as two cases of partial albinism.


A despeito de ser abundante em sua área de distribuição, a biologia de Myotis levis (I. Geoffroy, 1824) é pouco conhecida. Realizou-se uma campanha de campo com o objetivo de melhor conhecer alguns aspectos da história natural dessa espécie, em um abrigo (forro de casa). Coletaram-se informações através de capturas com redes de neblina posicionadas à saída do abrigo, durante três noites consecutivas, além de incursões feitas dentro do mesmo, com objetivo de fazer uma estimativa do número de indivíduos na colônia. A área de estudo situa-se nos Campos de Palmas, Município de Palmas, Sul do Paraná (26º3459S e 51º3616W). Foram capturados 186 indivíduos, sendo 96 adultos e 90 juvenis. O número de morcegos foi estimado entre 12 000 e 15 000 indivíduos. Pela estrutura da população, presença de fêmeas reprodutivas, juvenis e infantes caracterizou-se uma colônia maternidade. Além de aspectos da biologia reprodutiva, esse trabalho descreve variações morfométricas e de coloração e registra dois casos de albinismo parcial.

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