Response of young and adult birds to the same environmental variables and different spatial scales during post breeding period

Context: How do young birds achieve spatial knowledge about the environment during the initial stages of their life? They may follow adults, so gaining social information and learning; alternatively, young birds may acquire knowledge of the environment themselves by experiencing habitat and landscape features. If learning is at least partially independent of adults then young birds should respond to landscape composition at finer spatial scale than adults, who possess knowledge over a larger area. Objectives: We studied the responses of juvenile, immature and adult Caspian Gull Larus cachinnans to the same habitat and landscape variables, but at several spatial scales (ranging from 2.5 to 15\ua0km), during post-breeding period. Methods: We surveyed 61 fish ponds (foraging patches) in southern Poland and counted Caspian gulls. Results: Juvenile birds responded at finer spatial scales to the factors than did adults. Immature birds showed complicated, intermediate responses to spatial scale. The abundance of juvenile birds was mostly correlated with the landscape composition (positively with the cover of corridors and negatively with barriers). Adult abundance was positively related to foraging patch quality (fish stock), which clearly required previous spatial experience of the environment. The abundance of all age classes were moderately correlated with each other indicating that social behaviour may also contribute to the learning of the environment. Conclusions: This study shows that as birds mature, they respond differently to components of their environment at different spatial scales. This has considerable ecological consequences for their distribution across environments

Timing of Exposure and Bisphenol-A: Implications for Diabetes Development

Bisphenol-A (BPA) is one of the most widespread endocrine disrupting chemicals (EDCs). It is used as the base compound in the production of polycarbonate and other plastics present in many consumer products. It is also used as a building block in epoxy can coating and the thermal paper of cash register receipts. Humans are consistently exposed to BPA and, in consequence, this compound has been detected in the majority of individuals examined. Over the last decade, an enlarging body of evidence has provided a strong support for the role of BPA in the etiology of diabetes and other metabolic disorders. Timing of exposure to EDCs results crucial since it has important implications on the resulting adverse effects. It is now well established that the developing organisms are particularly sensitive to environmental influences. Exposure to EDCs during early life may result in permanent adverse consequences, which increases the risk of developing chronic diseases like diabetes in adult life. In addition to that, developmental abnormalities can be transmitted from one generation to the next, thus affecting future generations. More recently, it has been proposed that gestational environment may also program long-term susceptibility to metabolic disorders in the mother. In the present review, we will comment and discuss the contributing role of BPA in the etiology of diabetes. We will address the metabolic consequences of BPA exposure at different stages of life and comment on the final phenotype observed in different whole-animal models of study

G protein-coupled estrogen receptor activation by bisphenol-A disrupts the protection from apoptosis conferred by the estrogen receptors ERα and ERβ in pancreatic beta cells

17β-estradiol protects pancreatic β-cells from apoptosis via the estrogen receptors ERα, ERβ and GPER. Conversely, the endocrine disruptor bisphenol-A (BPA), which exerts multiple effects in this cell type via the same estrogen receptors, increased basal apoptosis. The molecular-initiated events that trigger these opposite actions have yet to be identified. We demonstrated that combined genetic downregulation and pharmacological blockade of each estrogen receptor increased apoptosis to a different extent. The increase in apoptosis induced by BPA was diminished by the pharmacological blockade or the genetic silencing of GPER, and it was partially reproduced by the GPER agonist G1. BPA and G1-induced apoptosis were abolished upon pharmacological inhibition, silencing of ERα and ERβ, or in dispersed islet cells from ERβ knockout (BERKO) mice. However, the ERα and ERβ agonists PPT and DPN, respectively, had no effect on beta cell viability. To exert their biological actions, ERα and ERβ form homodimers and heterodimers. Molecular dynamics simulations together with proximity ligand assays and coimmunoprecipitation experiments indicated that the interaction of BPA with ERα and ERβ as well as GPER activation by G1 decreased ERαβ heterodimers. We propose that ERαβ heterodimers play an antiapoptotic role in beta cells and that BPA- and G1-induced decreases in ERαβ heterodimers lead to beta cell apoptosis. Unveiling how different estrogenic chemicals affect the crosstalk among estrogen receptors should help to identify diabetogenic endocrine disruptors.This work was supported by Ministerio de Ciencia e Innovación, Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER) grants BPU2017-86579-R (AN), PID2020-117294RB-I00 (AN, JM-P), Generalitat Valenciana PROMETEO II/2020/006 (AN) and European Union’s Horizon 2020 research and innovation programme under grant agreement GOLIATH No. 825489 (AN). Author laboratories hold grants from Ministerio de Ciencia e Innovación, Agencia Estatal de Investigación y Fondo Europeo de Desarrollo Regional (FEDER) RTI2018-096724-B-C21 (J-AE) and PID2020-117569RA-I00 (LM). PROMETEO/2016/006 (J-AE) and SEJI/2018/023 (LM) supported by Generalitat Valenciana, Spain. Robert A. Welch Foundation (grant E-0004) (J-AG). CIBERDEM is an initiative of the Instituto de Salud Carlos III

Quantificação do número de amostras de solo para análise química em um planossolo do município de Guarabira - PB.

Para o reconhecimento da estimativa de fertilidade agrícola faz-se necessário a análise química do solo. Esta pesquisa teve como objetivo desenvolver o melhor critério de amostragem de solo para análise química e de granulometria para fins agrícolas. Foram analisados quatro critérios de amostragem, sendo eles; três amostras simples; duas amostras compostas formadas de cinco simples; duas amostras compostas formadas de dez simples e duas amostras compostas formadas de vinte simples, em uma área de 250 m2. Utilizando-se para a retirada das amostras um trado de caneca de 20 cm em um Planossolo Háplico Eutrófico solódico, localizado no município de Guarabira, no Agreste do Estado da Paraíba, utilizou-se a média(m) para a avaliação do erro padrão s(m) e o coeficiente de variação para as ariáveis dos seguintes parâmetros de fertilidade do solo: pHH2O, P, S-SO4 -2, K+, H+ + Al+3, Al+3, Ca+2, Mg+2 e M.O. (Matéria Orgânica), B, Fe, Cu, Mg e Zn, como também para as análises granulométricas. Com os resultados obtidos observouse que para a análise ranulométrica foram mais satisfatórios os critérios constituídos de duas amostras compostas formadas de dez simples e o duas amostras compostas formadas de vinte simples. No entanto não foi observado um comportamento regular entre os critérios de amostragem estudados para os macros e micronutrientes

Lymphocyte subsets in human immunodeficiency virus-unexposed Brazilian individuals from birth to adulthood

Ethnic origin, genetics, gender and environmental factors have been shown to influence some immunologic indices, so that development of reference values for populations of different backgrounds may be necessary. We have determined the distribution of lymphocyte subsets in healthy Brazilian individuals from birth to adulthood. Lymphocyte subsets were determined using four-colour cytometry in a cross-sectional study of 463 human immunodeficiency virus-unexposed children and adults from birth through 49 years of age. Lymphocyte subsets varied according to age, as previously observed in other studies. However, total CD4+ T cell numbers were lower than what was described in the Pediatric AIDS Clinical Trials Group P1009 (PACTG P1009), which assessed an American population of predominantly African and Hispanic backgrounds until the 12-18 year age range, when values were comparable. Naïve percentages and absolute values of CD8+ T cells, as assessed by CD45RA expression, were also lower than the PACTG P1009 data for all analysed age ranges. CD38 expression on both CD4+ and CD8+ T cells was lower than the PACTG P1009 values, with a widening gap between the two studies at older age ranges. Different patterns of cell differentiation seem to occur in different settings and may have characteristic expression within each population.Universidade Federal de São Paulo (UNIFESP) Departamento de MedicinaCentro Assistencial Cruz de MaltaUniversidade Federal de São Paulo (UNIFESP) Departamento de PediatriaUNIFESP, Depto. de MedicinaUNIFESP, Depto. de PediatriaSciEL