Phylogenetic diversity and the structure of host-epiphyte interactions across the Neotropics.

Understanding the mechanisms driving community assembly has been a major focus of ecological research for nearly a century, yet little is known about these mechanisms in commensal communities, particularly with respect to their historical/evolutionary components. Here, we use a large-scale dataset of 4,440 vascular plant species to explore the relationship between the evolutionary distinctiveness (ED) (as measured by the 'species evolutionary history' (SEH)) of host species and the phylogenetic diversity (PD) of their associated epiphyte species. Although there was considerable variation across hosts and their associated epiphyte species, they were largely unrelated to host SEH. Our results mostly support the idea that the determinants of epiphyte colonization success might involve host characteristics that are unrelated to host SEH (e.g., architectural differences between hosts). While determinants of PD of epiphyte assemblages are poorly known, they do not appear to be related to the evolutionary history of host species. Instead, they might be better explained by neutral processes of colonization and extinction. However, the high level of phylogenetic signal in epiphyte PD (independent of SEH) suggests it might still be influenced by yet unrecognized evolutionary determinants. This study highlights how little is still known about the phylogenetic determinants of epiphyte communities.

Host tree traits in pasture areas affect forest and pasture specialist epiphyte species differently.

PREMISE: Epiphytes have commensal relationships with their host trees. Besides the influence of tree traits, little has been discussed concerning the ecology of epiphytes in disturbed habitats (e.g., pasture). We herein tested whether the occurrences of pasture and forest specialist epiphytes in pastures are affected differently by tree traits. We hypothesized that (H1) the richness and abundance of generalist epiphytes would be positively associated with area availability; (H2) the richness and abundance of forest epiphyte species would be associated both with (H2.a) area availability and (H2.b) tree traits related to higher seed adherence, and/or (H2.c) less severe habitat (e.g., high humidity and more shade). METHODS: We sampled 9567 epiphyte individuals from 16 species on 759 scattered remnant trees. The epiphyte species were divided into two ecological groups: forest specialists and pasture specialists. We evaluated four host tree traits: two related to tree size (crown area and trunk diameter) and two related to habitat type (crown leaf density and bark rugosity). RESULTS: The richness and abundance of both pasture and forest specialists were positively related with tree size. However, the abundance of pasture specialists was negatively related with crown leaf density, whereas richness of forest epiphytes was positively related with bark rugosity. CONCLUSIONS: Large scattered trees tend to present higher richness and abundance of both pasture and forest specialist epiphytes compared to the smaller trees. However, high crown leaf density limits abundance of pasture specialist epiphytes, whereas rugose bark increases the richness of forest epiphytes.

Endoscopic sleeve gastroplasty in the management of weight regain after sleeve gastrectomy.

BACKGROUND: Sleeve gastrectomy is a well-standardized surgical treatment for obesity. However, rates of weight regain after sleeve gastrectomy in long-term follow-up are relatively high. This multicenter study is the first to evaluate the use of an endoscopic sleeve gastroplasty (ESG) technique for the management of this population. METHODS: This was a multicenter retrospective study, including patients with weight regain following sleeve gastrectomy who underwent ESG for weight loss. Primary outcomes included absolute weight loss, percent total weight loss (%TWL), change in body mass index (BMI), percent excess weight loss (%EWL) at 6 and 12 months, and safety profile. Clinical success was defined as achieving ≥ 25 % EWL at 1 year, ≤ 5 % serious adverse event (SAE) rate following society-recommended thresholds, and %TWL ≥ 10 %. RESULTS: 34 patients underwent ESG after sleeve gastrectomy. Technical success was 100 %. At 1 year, 82.4 % and 100 % of patients achieved ≥ 10 %TWL and ≥ 25 % EWL, respectively. Mean (SD) %TWL was 13.2 % (3.9) and 18.3 % (5.5), and %EWL was 51.9 % (19.1) and 69.9 % (29.9) at 6 months and 1 year, respectively. Mean (SD) %TWL was 14.2 % (12.5), 19.3 % (5.3), 17.5 % (5.2), and 20.4 % (3.3), and %EWL was 88.5 % (52.8), 84.4 % (22.4), 55.4 % (14.8), and 47.8 % (11.2) for BMI categories of overweight and obesity class I, II, and III, respectively, at 1 year. No predictors of success were identified in the multivariable regression analysis. No SAEs were reported. CONCLUSION: ESG appears to be safe and effective in the management of weight regain following sleeve gastrectomy.

FragSAD: A database of diversity and species abundance distributions from habitat fragments.

Habitat destruction is the single greatest anthropogenic threat to biodiversity. Decades of research on this issue have led to the accumulation of hundreds of data sets comparing species assemblages in larger, intact, habitats to smaller, more fragmented, habitats. Despite this, little synthesis or consensus has been achieved, primarily because of non-standardized sampling methodology and analyses of notoriously scale-dependent response variables (i.e., species richness). To be able to compare and contrast the results of habitat fragmentation on species' assemblages, it is necessary to have the underlying data on species abundances and sampling intensity, so that standardization can be achieved. To accomplish this, we systematically searched the literature for studies where abundances of species in assemblages (of any taxa) were sampled from many habitat patches that varied in size. From these, we extracted data from several studies, and contacted authors of studies where appropriate data were collected but not published, giving us 117 studies that compared species assemblages among habitat fragments that varied in area. Less than one-half (41) of studies came from tropical forests of Central and South America, but there were many studies from temperate forests and grasslands from all continents except Antarctica. Fifty-four of the studies were on invertebrates (mostly insects), but there were several studies on plants (15), birds (16), mammals (19), and reptiles and amphibians (13). We also collected qualitative information on the length of time since fragmentation. With data on total and relative abundances (and identities) of species, sampling effort, and affiliated meta-data about the study sites, these data can be used to more definitively test hypotheses about the role of habitat fragmentation in altering patterns of biodiversity. There are no copyright restrictions. Please cite this data paper and the associated Dryad data set if the data are used in publications.

Endoscopic sleeve gastroplasty in the management of overweight and obesity: an international multicenter study.

BACKGROUND AND AIMS: Obesity is a pandemic affecting approximately 700 million adults worldwide, with an additional 2 billion overweight. Endoscopic sleeve gastroplasty (ESG) is a minimally invasive endoscopic bariatric therapy that involves remodeling of the greater curvature in an effort to reduce gastric capacity and delay gastric emptying. A variety of ESG suture patterns has been reported. This study is the first to use a uniform "U" stitch pattern across all centers to simplify technical aspects of the procedure and limit cost. This also uniquely assessed outcomes in all body mass index (BMI) categories and changes in metabolic rate, lean body mass, and adipose tissue composition. METHODS: This is a multicenter analysis of prospectively collected data from 7 centers including patients with overweight and obesity who underwent ESG. Primary outcomes included absolute weight loss, percent total body weight loss (%TWL), change in BMI, and percent excess weight loss (%EWL) at 6 and 12 months in overweight and obese classes I, II, and III. Secondary outcomes included adipose tissue, lean body mass reduction, and metabolic rate analyzed by bioimpedance. Additionally, immediate or delayed adverse events (AEs) were analyzed. Clinical success was defined as achieving ≥25% EWL at 1 year with ≤5% serious AE (SAE) rate following the American Society for Gastrointestinal Endoscopy (ASGE)/American Society for Metabolic and Bariatric Surgery (ASMBS) threshold. RESULTS: A total of 193 patients underwent ESG during the study period. All groups had >10% TWL and >25% EWL at 6 months of follow-up. On average, %TWL was 14.25% ± 5.26% and 15.06% ± 5.22% and the %EWL 56.15% ± 22.93% and 59.41% ± 25.69% at 6 months and 1 year of follow-up, respectively. %TWL was 8.91% ± .3%, 13.92% ± 5.76%, 16.22% ± 7.69%, and 19.01% ± .95% and %EWL 56.21% ± 2.0%, 62.03% ± 27.63%, 54.13% ± 23.46%, and 46.78% ± 2.43% for overweight and obesity classes I, II, and III, respectively, at 1 year. Male sex, age <41 years, and higher BMI were predictors of achieving a TWL ≥10% at 1-year follow-up. There was a significant reduction in adipose tissue from baseline. SAEs occurred in 1.03%, including 2 perigastric collections needing surgery. CONCLUSIONS: ESG appears to be feasible, safe, and effective in the treatment of patients with overweight and obesity according to ASGE/ASMBS thresholds.

ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest.

Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events.

Agricultural matrices affect ground ant assemblage composition inside forest fragments.

The establishment of agricultural matrices generally involves deforestation, which leads to fragmentation of the remaining forest. This fragmentation can affect forest dynamics both positively and negatively. Since most animal species are affected, certain groups can be used to measure the impact of such fragmentation. This study aimed to measure the impacts of agricultural crops (matrices) on ant communities of adjacent lower montane Atlantic rainforest fragments. We sampled nine forest fragments at locations surrounded by different agricultural matrices, namely: coffee (3 replicates); sugarcane (3); and pasture (3). At each site we installed pitfall traps along a 500 m transect from the interior of the matrix to the interior of the fragment (20 pitfall traps ~25 m apart). Each transect was partitioned into four categories: interior of the matrix; edge of the matrix; edge of the fragment; and interior of the fragment. For each sample site, we measured ant species richness and ant community composition within each transect category. Ant richness and composition differed between fragments and matrices. Each sample location had a specific composition of ants, probably because of the influence of the nature and management of the agricultural matrices. Species composition in the coffee matrix had the highest similarity to its corresponding fragment. The variability in species composition within forest fragments surrounded by pasture was greatest when compared with forest fragments surrounded by sugarcane or, to a lesser extent, coffee. Functional guild composition differed between locations, but the most representative guild was 'generalist' both in the agricultural matrices and forest fragments. Our results are important for understanding how agricultural matrices act on ant communities, and also, how these isolated forest fragments could act as an island of biodiversity in an 'ocean of crops'.

Efficacy of Utilizing Argon Plasma Coagulation for Weight Regain in Roux-en-Y Gastric Bypass Patients: a Multi-center Study.

BACKGROUND: Endoscopic approaches exist for targeting weight regain after Roux-en-Y gastric bypass (RYGB), including endoscopic suturing, clipping, and sclerotherapy. Argon plasma coagulation (APC) is a noncontact electrocoagulation method, and when used in RYGB patients, it has shown reduction in the diameter of the gastrojejunal anastomosis. OBJECTIVES: To study the effectiveness of APC for weight regain in terms of weight loss for RYGB patients, from eight bariatric centers. METHODS: A retrospective chart review was performed for 558 patients at eight bariatric centers in the USA (1) and Brazil (7) who underwent APC procedure between 31st July 2009 and 29th March 2017. APC was performed on patients who regained weight after RYGB procedure. RESULTS: Upon exploratory analysis of the individual BMI data, the mean BMI decreased slightly during the first 24 months and increased slightly afterwards following the APC intervention. The mean weight was 94.5 ± 18.6 kg and the mean BMI was 34.0 kg/m2 at APC. Where data were available, the mean of lowest weight was 67.0 ± 23.0 kg and the mean of lowest BMI was 24.1 kg/m2 following gastric bypass. The mean weight loss was 6.5, 7.7, and 8.3 kg at 6, 12, and 24 months, respectively, and the changes in weight over time was statistically significant (p < 0.0001). Multi-level for change model showed the low body mass index (BMI) group (BMI < 30 kg/m2) to have greater TWL than the high BMI (BMI ≥ 30 kg/m2) group at 6, 12, and 24 months. In the low BMI group, the mean TWL was 4.7, 6.1, 6.9, and 2.4%, at 6, 12, and 24 months, respectively. In the high BMI group, the mean TWL was 7.5, 10.4, 13.4, and 3.7%, at 6, 12, 24, and 36 months, respectively. Of the 333 patients in four centers who provided complication information, complications after APC included stenosis (n = 9), GJ ulcer (n = 3), vomiting (n = 3), GJ leakage (n = 2), and melena (n = 1). CONCLUSION: APC can be useful in reducing the regained weight after RYGB, and patients showed 6-10% total weight loss at 12 months. Randomized trials would be needed to validate the findings.

Anthropogenic Matrices Favor Homogenization of Tree Reproductive Functions in a Highly Fragmented Landscape.

Species homogenization or floristic differentiation are two possible consequences of the fragmentation process in plant communities. Despite the few studies, it seems clear that fragments with low forest cover inserted in anthropogenic matrices are more likely to experience floristic homogenization. However, the homogenization process has two other components, genetic and functional, which have not been investigated. The purpose of this study was to verify whether there was homogenization of tree reproductive functions in a fragmented landscape and, if found, to determine how the process was influenced by landscape composition. The study was conducted in eight fragments in southwest Brazil. The study was conducted in eight fragments in southwestern Brazil. In each fragment, all individual trees were sampled that had a diameter at breast height ≥3 cm, in ten plots (0.2 ha) and, classified within 26 reproductive functional types (RFTs). The process of functional homogenization was evaluated using additive partitioning of diversity. Additionally, the effect of landscape composition on functional diversity and on the number of individuals within each RFT was evaluated using a generalized linear mixed model. appeared to be in a process of functional homogenization (dominance of RFTs, alpha diversity lower than expected by chance and and low beta diversity). More than 50% of the RFTs and the functional diversity were affected by the landscape parameters. In general, the percentage of forest cover has a positive effect on RFTs while the percentage of coffee matrix has a negative one. The process of functional homogenization has serious consequences for biodiversity conservation because some functions may disappear that, in the long term, would threaten the fragments. This study contributes to a better understanding of how landscape changes affect the functional diversity, abundance of individuals in RFTs and the process of functional homogenization, as well as how to manage fragmented landscapes.

Gestão de pessoas: uma abordagem epistemológica / People management: an epistemological approach / Gestión de personas: un enfoque epistemológico

As transformações pelas quais passa o processo de produção de conhecimento científico nos últimos anos têm deflagrado oportunidades criativas e de mudanças paradigmáticas sobre conhecimento, ciência, pesquisa, intervenção sobre grupos sociais e proposições teóricas. O objetivo deste trabalho é apresentar reflexões envolvendo o debate em torno do que se convencionou chamar de gestão de pessoas no mundo das organizações e a constituição da área de conhecimento como campo teórico e prática social que, historicamente, consolidou-se a partir de uma visão racional, objetiva e normativa dos indivíduos nas organizações. O artigo, portanto, constitui-se como ensaio teórico, cujo suporte principal é expor conceitos, argumentos e autores que produziram esforços na tentativa de definir precisamente os âmbitos dos estudos organizacionais a partir de duas formações teóricas: reducionistas e complexidades sistêmicas. Procurar-se-á compreender as formulações teóricas investigando os conceitos de gestão de pessoas no âmbito dos estudos organizacionais a partir de reflexões epistemológicas. O campo principal deste ensaio teórico está focado em compreensões no processo de gestão de pessoas e algumas de suas práticas mais conhecidas, como avaliação de desempenho, remuneração estratégica, bem como a gestão por habilidades e competências e as contraditórias concepções de aprendizagem organizacional. A gestão de pessoas parece refletir as ambiguidades e os paradoxos organizacionais. Diante deste quadro, o artigo procura investigar duas formações teóricas: reducionistas e complexidades sistêmicas. Procurou-se compreender as formas segundo as quais autores produzem diferenças e semelhanças nessas formulações teóricas, investigando os conceitos de sociedade e ambiente associados aos estudos organizacionais e a forma como a gestão de pessoas é compreendida como ciência reducionista.(AU)

The changes that have taken place in the production of scientific knowledge in recent years have led to creative opportunities and paradigmatic changes in the areas of knowledge, science, research, intervention on social groups, and theoretical proposals. This work presents some reflections on the debate surrounding what is known as people management in the world of organizations, and the constitution of the area of knowledge, as a theoretical field and as a social practice that has, historically, been built based on a rational, objective and regulatory view of individuals in organizations. This article therefore constitutes a theoretical assay, based on concepts, arguments and authors who have attempted to define, more precisely, the scope of organizational studies, based on two theoretical constructions: reductionist and systemic complexities. This work seeks to understand the theoretical formulations, investigating the concepts of people management within organizational studies, based on epistemological reflections. The main field of this theoretical assay is focused on understanding the people management process, and some of its more well-known practices, such as performance appraisal, strategic remuneration, management by skills and competencies, and the contradictory concepts that exist in the field of organizational learning. People management appears to reflect the organizational ambiguities and paradoxes. It seeks to understand the ways in which authors produce differences and similarities in these theoretical formulations, investigating the concepts of society and environment associated with organizational studies, and the form in which people management is understood as a reductionist science.(AU)

Las transformaciones a través del cual pasa el proceso de producción del conocimiento científico en los últimos años han desencadenado oportunidades creativas y cambios paradigmáticos sobre conocimiento, ciencia, investigación, intervención en grupos sociales y las proposiciones teóricas. El objetivo de este trabajo es presentar reflexiones rodean el debate en torno a los llamados de la administración de personal en el mundo de las organizaciones y el establecimiento del área de conocimiento como un campo teórico y prácticas sociales que, históricamente, se ha consolidado desde una visión racional, objetiva y normativa de los individuos en las organizaciones. El artículo se constituye por lo tanto como una prueba teórica, cuyo soporte principal es conceptos expuestos, argumentos y autores que producen los esfuerzos en un intento por definir precisamente las áreas de estudios organizacionales de dos formaciones teóricas: reduccionista y complejidad sistémica. Busca entender las formulaciones teóricas investigar conceptos de gestión. El campo principal de este ensayo se centra en la comprensión teórica en gestión de casos de personas y algunas de sus prácticas más conocidas como la evaluación del desempeño, remuneración, así como las habilidades de gestión estratégica y las competencias y las concepciones contradictorias del aprendizaje organizacional. Gestión de personas parece reflejar las ambigüedades y las paradojas. En este cuadro, el artículo intenta investigar dos formaciones teóricas: reduccionista y complejidad sistémica. Tratamos de comprender las formas en las que autores producen diferencias y similitudes en estas formulaciones teóricas, investigando los conceptos de sociedad y medio ambiente asociados a estudios organizacionales y la forma en la gestión de personas es entendida como la ciencia reduccionista.(AU)

Les transformations par lesquelles passe le processus de production des connaissances scientifiques au cours des dernières années ont déclenché des possibilités créatives et changements paradigmatiques sur la connaissance, science, recherche, intervention sur les groupes sociaux et des propositions théoriques. Le but de ce travail est de présenter les réflexions entourant le débat autour de ce qu'on appelle de la gestion du personnel dans le monde des organisations et la mise en place de la zone de la connaissance comme un champ théorique et pratique sociale qui, historiquement, s'est renforcée d'une vision rationnelle, objective et normative des individus dans les organisations. L'article se constitue par conséquent un test théorique, dont le principal soutien est exposé des concepts, des arguments et des auteurs qui ont produit des efforts pour tenter de définir précisément les domaines d'études organisationnelles de deux formations théoriques : réductionnistes et complexité systémiques. Chercher à comprendre les formulations théoriques étudie les concepts de gestion. Le domaine principal de cet essai se concentre sur la compréhension théorique dans la prise en charge des personnes et certaines de ses pratiques plus connus tels que l'évaluation de la performance, rémunération, ainsi que les compétences en gestion stratégique et les compétences et les conceptions contradictoires de l'apprentissage organisationnel. Gestion des ressources humaines semble refléter les ambiguïtés et les paradoxes. Sur cette photo, l'article tente d'enquêter sur les deux formations théoriques : réductionnistes et complexité systémiques. Nous avons essayé de comprendre les façons dont auteurs produisent des différences et des similitudes dans ces formulations théoriques, enquêter sur les concepts de la société et l'environnement associés aux études organisationnelles et la façon dont la gestion des ressources humaines est comprise comme la science réductionniste.(AU)

Gestão de pessoas: uma abordagem epistemológica / People management: an epistemological approach / Gestión de personas: un enfoque epistemológico / Gestión de personas: un enfoque epistemológico

As transformações pelas quais passa o processo de produção de conhecimento científico nos últimos anos têm deflagrado oportunidades criativas e de mudanças paradigmáticas sobre conhecimento, ciência, pesquisa, intervenção sobre grupos sociais e proposições teóricas. O objetivo deste trabalho é apresentar reflexões envolvendo o debate em torno do que se convencionou chamar de gestão de pessoas no mundo das organizações e a constituição da área de conhecimento como campo teórico e prática social que, historicamente, consolidou-se a partir de uma visão racional, objetiva e normativa dos indivíduos nas organizações. O artigo, portanto, constitui-se como ensaio teórico, cujo suporte principal é expor conceitos, argumentos e autores que produziram esforços na tentativa de definir precisamente os âmbitos dos estudos organizacionais a partir de duas formações teóricas: reducionistas e complexidades sistêmicas. Procurar-se-á compreender as formulações teóricas investigando os conceitos de gestão de pessoas no âmbito dos estudos organizacionais a partir de reflexões epistemológicas. O campo principal deste ensaio teórico está focado em compreensões no processo de gestão de pessoas e algumas de suas práticas mais conhecidas, como avaliação de desempenho, remuneração estratégica, bem como a gestão por habilidades e competências e as contraditórias concepções de aprendizagem organizacional. A gestão de pessoas parece refletir as ambiguidades e os paradoxos organizacionais. Diante deste quadro, o artigo procura investigar duas formações teóricas: reducionistas e complexidades sistêmicas. Procurou-se compreender as formas segundo as quais autores produzem diferenças e semelhanças nessas formulações teóricas, investigando os conceitos de sociedade e ambiente associados aos estudos organizacionais e a forma como a gestão de pessoas é compreendida como ciência reducionista.

The changes that have taken place in the production of scientific knowledge in recent years have led to creative opportunities and paradigmatic changes in the areas of knowledge, science, research, intervention on social groups, and theoretical proposals. This work presents some reflections on the debate surrounding what is known as people management in the world of organizations, and the constitution of the area of knowledge, as a theoretical field and as a social practice that has, historically, been built based on a rational, objective and regulatory view of individuals in organizations. This article therefore constitutes a theoretical assay, based on concepts, arguments and authors who have attempted to define, more precisely, the scope of organizational studies, based on two theoretical constructions: reductionist and systemic complexities. This work seeks to understand the theoretical formulations, investigating the concepts of people management within organizational studies, based on epistemological reflections. The main field of this theoretical assay is focused on understanding the people management process, and some of its more well-known practices, such as performance appraisal, strategic remuneration, management by skills and competencies, and the contradictory concepts that exist in the field of organizational learning. People management appears to reflect the organizational ambiguities and paradoxes. It seeks to understand the ways in which authors produce differences and similarities in these theoretical formulations, investigating the concepts of society and environment associated with organizational studies, and the form in which people management is understood as a reductionist science.

Las transformaciones a través del cual pasa el proceso de producción del conocimiento científico en los últimos años han desencadenado oportunidades creativas y cambios paradigmáticos sobre conocimiento, ciencia, investigación, intervención en grupos sociales y las proposiciones teóricas. El objetivo de este trabajo es presentar reflexiones rodean el debate en torno a los llamados de la administración de personal en el mundo de las organizaciones y el establecimiento del área de conocimiento como un campo teórico y prácticas sociales que, históricamente, se ha consolidado desde una visión racional, objetiva y normativa de los individuos en las organizaciones. El artículo se constituye por lo tanto como una prueba teórica, cuyo soporte principal es conceptos expuestos, argumentos y autores que producen los esfuerzos en un intento por definir precisamente las áreas de estudios organizacionales de dos formaciones teóricas: reduccionista y complejidad sistémica. Busca entender las formulaciones teóricas investigar conceptos de gestión. El campo principal de este ensayo se centra en la comprensión teórica en gestión de casos de personas y algunas de sus prácticas más conocidas como la evaluación del desempeño, remuneración, así como las habilidades de gestión estratégica y las competencias y las concepciones contradictorias del aprendizaje organizacional. Gestión de personas parece reflejar las ambigüedades y las paradojas. En este cuadro, el artículo intenta investigar dos formaciones teóricas: reduccionista y complejidad sistémica. Tratamos de comprender las formas en las que autores producen diferencias y similitudes en estas formulaciones teóricas, investigando los conceptos de sociedad y medio ambiente asociados a estudios organizacionales y la forma en la gestión de personas es entendida como la ciencia reduccionista.

Les transformations par lesquelles passe le processus de production des connaissances scientifiques au cours des dernières années ont déclenché des possibilités créatives et changements paradigmatiques sur la connaissance, science, recherche, intervention sur les groupes sociaux et des propositions théoriques. Le but de ce travail est de présenter les réflexions entourant le débat autour de ce qu'on appelle de la gestion du personnel dans le monde des organisations et la mise en place de la zone de la connaissance comme un champ théorique et pratique sociale qui, historiquement, s'est renforcée d'une vision rationnelle, objective et normative des individus dans les organisations. L'article se constitue par conséquent un test théorique, dont le principal soutien est exposé des concepts, des arguments et des auteurs qui ont produit des efforts pour tenter de définir précisément les domaines d'études organisationnelles de deux formations théoriques : réductionnistes et complexité systémiques. Chercher à comprendre les formulations théoriques étudie les concepts de gestion. Le domaine principal de cet essai se concentre sur la compréhension théorique dans la prise en charge des personnes et certaines de ses pratiques plus connus tels que l'évaluation de la performance, rémunération, ainsi que les compétences en gestion stratégique et les compétences et les conceptions contradictoires de l'apprentissage organisationnel. Gestion des ressources humaines semble refléter les ambiguïtés et les paradoxes. Sur cette photo, l'article tente d'enquêter sur les deux formations théoriques : réductionnistes et complexité systémiques. Nous avons essayé de comprendre les façons dont auteurs produisent des différences et des similitudes dans ces formulations théoriques, enquêter sur les concepts de la société et l'environnement associés aux études organisationnelles et la façon dont la gestion des ressources humaines est comprise comme la science réductionniste.

Polymorphisms involved in folate metabolism pathways and the risk of the development of childhood acute leukemia.

OBJECTIVE: Polymorphisms that reduce the activity of reduced folate carrier (RFC) and methylenetetrahydrofolate reductase (MTHFR) and double (2R2R) or triple (3R3R) 28-bp tandem repeats in the promoter region of thymidylate synthase (TS) have been associated with the risk of childhood acute leukemia (AL). A case-control genotyping study was conducted in Brazilian children with the aim of investigating RFC, MTHFR, and TS polymorphisms as risk factors. METHODS: The polymerase chain reaction-restriction fragment length polymorphism method was employed in 177 AL cases and 390 controls. RESULTS: The presence of the mutant 1298C, also RFC 80A, was linked to a decreased risk of developing acute lymphoid leukemia (ALL) (odds ratio (OR)=0.46, 95% confidence interval (CI)=0.30-071 and OR=0.51, 95% CI=0.28-0.0.93, respectively). CONCLUSIONS: The genotype 677 CT was associated with increased risk of developing ALL (OR=1.6, 95% CI=1.1-2.7). Further epidemiological study is needed to unravel the role of complex multiple gene-environment interactions in leukemogenesis.

Efeito do tamanho do fragmento na dispersão de sementes de Copaíba (Copaifera langsdorffii Delf.) / Effect of fragment size on Copaifera langsdorffii seeds dispersal

A fragmentação de habitats pode afetar negativamente a relação mutualística entre plantas e animais, se estes tornarem-se localmente extintos nos fragmentos. No decorrer do processo de fragmentação há evidências de substituição de espécies especialistas por generalistas, adotando também sua função no ecossistema. Nós estudamos a frugivoria de Copaifera langsdorfii por aves para avaliar o efeito do tamanho do fragmento no potencial de dispersão das suas sementes. Durante o ano de 2008 foram selecionadas vinte plantas focais distribuídas em cinco remanescentes de Mata Atlântica (amplitude 29,2 a 104,8 ha) para descrever o comportamento de forrageamento de aves consumidoras e avaliar o potencial de dispersão de sementes de cada espécie através do método de observação focal. O potencial de dispersão variou entre as espécies, juntamente com o padrão de distribuição e abundância nos diferentes fragmentos. O tamanho dos fragmentos afetou positivamente o número de interações de espécies com bom potencial de dispersão (R2 = 0,85; p = 0,05). A riqueza de espécies com má qualidade de dispersão foi negativamente afetada pelo tamanho do fragmento, mas com significância marginal (R2 = 0,77; p= 0,08). Portanto a preservação de fragmentos de maior tamanho garante mais eventos de interação entre a C. langsdorfii e seus bons dispersores, e consequentemente favorece seu sucesso reprodutivo.

Effect of fragment size on Copaifera langsdorffii seed dispersal. Habitat fragmentation may cause functional disruption in seed dispersal, if the disperser species become locally extinct in the fragments. However during the fragmentation process, there is empirical evidence of replacement of specialist by generalist species, and these generalist species could also replace the functional activity of the specialists in the ecosystem. We studied bird frugivory on C. langsdorffii in order to evaluate the patch size effect on the potential of seed dispersal of this plant. During 2008 we chose 20 focal trees distributed in five Atlantic forest remnants (range 29.2 to 104.8 ha), looking for which bird species consumed the fruits, describing their foraging behavior and consequently evaluating the potential for seed dispersal. The results suggest that there was lower similarity of bird richness among the patches. The ability to disperse seeds also varied among birds and their patterns of distribution and abundance were related with patch size. The number of good disperser species and their interactions were positively related with patch size (R2 = 0.85; p = 0.05); in contrast, the poor dispersers had the opposite tendency (R2 = 0.77; p=0.08). Therefore the preservation of larger patch size increases the interaction events between C. langsdorffii and their good dispersers, and consequently improving their fitness.

Genetic structure of tree and shrubby species among anthropogenic edges, natural edges, and interior of an atlantic forest fragment.

Two species, Psychotria tenuinervis (shrub, Rubiaceae) and Guarea guidonia (tree, Meliaceae), were used as models to compare the genetic structure of tree and shrubby species among natural edges, anthropogenic edges, and a fragment interior. There were significant differences between two genetic markers. For isozymes, P. tenuinervis presented greater heterozygosity (expected and observed) and a higher percentage of polymorphic loci and median number of alleles than G. guidonia. For microsatellites, there was no difference in genetic variability between the species. Only P. tenuinervis, for isozymes, showed differences in genetic variability among the three habitats. There was no genetic structure (F (ST) < 0.05) among habitats in both plant species for both genetic markers. Isozymes showed great endogamy for both plant species, but not microsatellites. The forest fragmentation may have negative effects on both spatial (among edges and interior) and temporal genetic variability.

Mating systems of Psychotria tenuinervis (Rubiaceae): distance from anthropogenic and natural edges of Atlantic forest fragment.

The aim of this study was to determine and compare the mating systems among Psychotria tenuinervis populations at anthropogenic edges, natural edges, and the forest interior using allozyme electrophoresis of naturally pollinated progeny arrays. P. tenuinervis showed low outcrossing rates, varying from 37% to 50% of the mating attributable to outcrossing and 50% to 63% attributable to self-fertilization, in the three habitats. The forest interior had the highest outcrossing rate (t(m) = 0.50 and t(s) = 0.43) among the three habitats. However, there were no differences in either multilocus or single-locus rates among the three habitats, indicating that the contribution of biparental inbreeding to the apparent selfing rate in these populations was very low. The multilocus (t(m)) and single-locus (t(s)) outcrossing rates for the P. tenuinervis in the sample plots within each habitat showed great heterogeneity. In conclusion, edge creation seems not to influence its mating systems. Additionally, although P. tenuinervis is a distylous species, the population's inbreeding can be attributed almost entirely to self-fertilization.

Quality of seeds produced by Psychotria tenuinervis (Rubiaceae): distance from anthropogenic and natural edges of Atlantic forest fragment.

The aim of this study was to investigate whether there were differences in the genetic variability and rate and velocity of the seed germination produced by Psychotria tenuinervis located at anthropogenic edges, natural edges, and in the forest interior. The populations of P. tenuinervis showed no differences in genetic variability or structure among the three habitats. There was, however, an indication of inbreeding, which was significantly higher in natural edges than in anthropogenic edges and the forest interior. Within-habitat variation was considerable, but there were no differences in seed mass or rate and velocity of germination among the three habitats. These results suggest that seed characteristics were not influenced by the genetic pattern of P. tenuinervis and that other characteristics of the forest fragment, such as gaps, edge age, and type of matrix exert more influence on seed mass and germination than the distance from the edges.

Alzheimer's disease in Brazilian elderly has a relation with homocysteine but not with MTHFR polymorphisms / A doença de Alzheimer em idosos brasileiros tem relação com homocisteina mas não com polimorfismos MTHFR

OBJECTIVE: To investigate the association between total plasma homocysteine concentration, C677T and A1298C polymorphisms in MTHFR gene and Alzheimer's disease (AD) development. METHOD: Forty-three patients with probable (63 percent) and possible (37 percent) AD and 50 non-demented controls were evaluated. Groups did not differ as to gender, age, scholar years, diabetes, alcohol and coffee intake and physical activity. Total plasma homocysteine (Hcy) levels were determined by HPLC and genotyping for MTHFR by PCR/RFLP. Mann-Whitney "U" test was used to compare quantitative variable, Fisher-Freeman-Halton test to compare genotypes and allele proportions and Chi-square test to other qualitative variables. RESULTS: AD patients presented higher total plasma Hcy levels than controls and the difference was statistically significant. No differences in the C677T and A1298C MTHFR polymorphisms distributions were found between patients and controls. Plasma homocysteine concentration did not change with MTHFR genotypes. CONCLUSION: Our data confirms the association between increased plasma Hcy concentration and AD and suggests that neither C677T nor A1298C MTHFR polymorphisms contributed to genetic susceptibility for AD in elderly individuals in the Northeast of Brazil.

OBJETIVO: Investigar a associação entre a concentração plasmática total de homocisteína (Hcy), os polimorfismos C677T e A1298C do gene MTHFR e o desenvolvimento da Doença de Alzheimer (AD). MÉTODO: Foram avaliados 43 pacientes com doença de Alzheimer possível (37 por cento) e provável (63 por cento) e 50 controles não dementes, não divergentes quanto ao sexo, idade, anos de escolaridade, diabetes, consumo de álcool e de café e vida sedentária. Os níveis plasmáticos de homocisteína foram determinados por HPLC e a genotipagem para MTHFR por PCR/RFLP. A comparação dos níveis de homocisteína foi realizada pelo teste "U" Mann-Whitney, a comparação das proporções dos genótipos e alelos pelo teste de Fisher-Freeman-Halton e as demais variáveis qualitativas, pelo teste do qui-quadrado. RESULTADOS: Os pacientes AD apresentaram níveis mais elevados de Hcy plamática total do que os controles e a diferença entre os grupos foi estatisticamente significante. Não houve diferença nas distribuições genotípicas C677T e A1298C entre pacientes e controles. A concentração de Hcy não variou com os genótipos. CONCLUSÃO: Nossos dados confirmam a associação de concentração elevada de Hcy plasmática com DA e sugerem que os polimorfismos C677T e A1209C não contribuem para a susceptibilidade genética a DA em idosos do Nordeste do Brasil.

Microclimate of Atlantic forest fragments: regional and local scale heterogeneity

The aim of this work was to investigate whether (i) the organisms within different fragments, on regional scale (separated by up to 100 km), could be submitted to similar climatic conditions (rainfall and temperature), and whether (ii) the edge formation in forest fragments could stimulate microclimatic changes (canopy cover, air temperature and soil humidity), on local scale. The organisms within different fragments, on regional scale, were submitted to different climatic conditions, and the edge formation in the forest fragment stimulated microclimatic changes, on local scale, although in a heterogenic way. Not just the distance from the edge influenced the microclimatic differences. Probably, the edge age, location, the matrix structure, as well as, gap proximity could change the microclimatic even within edges.

O objetivo deste trabalho foi investigar se (i) os organismos dentro de diferentes fragmentos, em escala regional (separados por até 100 km), podem ser submetidos a condições climáticas similares (pluviosidade e temperatura) e se (ii) a formação de borda em fragmentos florestais pode estimular mudanças microclimáticas (abertura de dossel, temperatura do ar e umidade do solo), em escala regional. O estudo foi conduzido em cinco fragmentos (escala regional) no Rio de Janeiro, sudeste do Brasil, e em escala local, dentro de um deles. Os organismos dentro dos diferentes fragmentos, em escala regional, foram submetidos a diferentes condições climáticas, e a formação de borda nos fragmentos florestais estimulou mudanças climáticas, de maneira heterogênea. Não apenas a distância das bordas tem influencia nas diferenças microclimáticas. Provávelmente, a idade e localização da borda, a estrutura da matriz, assim como a proximidade de clareiras pode modificar o microclima mesmo entre bordas.

Association between the MTHFR A1298C polymorphism and increased risk of acute myeloid leukemia in Brazilian children.

Methylenetetrahydrofolate reductase (MTHFR) is an essential enzyme in the metabolism of folate. The presence of polymorphisms that reduce the activity of MTHFR has been linked to the multifactor process of development of acute leukemia. A case control study was conducted on Brazilian children in different regions of the country with the aim of investigating the role of MTHFR C677T and A1298C polymorphisms as risk factors in the development of acute myeloid leukemia (AML). We used the polymerase chain reaction restriction fragment length polymorphism method to genotyping 182 AML and 315 healthy individuals. The genotype 677 CT was associated with decreased risk [odds ratio (OR), 0.37; confidence interval (CI) 95%, 0.14 - 0.92], whereas 1298 AC genotype was linked with an increased risk [OR, 2.90; CI 95%, 1.26 - 6.71] of developing AML in non-white children. Further epidemiological study is needed to unravel the complex multiple gene-environment interactions in the role of the AML leukemogenesis.

The role of methylenetetrahydrofolate reductase in acute lymphoblastic leukemia in a Brazilian mixed population.

The polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene are associated with leukemogenesis. In order to investigate the influence of two polymorphisms in the MTHFR gene, 677C>T and 1298A>C, on the risk of acute lymphoblastic leukemia (ALL) we performed a case-control study in children from different Brazilians' regions. Genotyping of 176 ALL and 199 unselected healthy subjects was performed using PCR-RFLP assay. There was no association between the 677C>T or 1298A>C and risk of ALL in total case-control sample. However, 677T allele was linked to a decrease risk of ALL [odds ratio (OR), 0.43; 95% confidence interval (CI), 0.22-0.86], whereas the 1298A>C polymorphism presents an elevated risk factor [OR, 2.01; 95% CI, 1.01-3.99] in non-White children. Our investigation provides interesting data concerning the opposite effect of A1298C polymorphisms, particularly in the light of relatively scarce data regarding the MTHFR role in leukemia susceptibility in different populations.