28 research outputs found
Immediate and Late Effects of Stress on Kidneys of Prepubertal and Adult Rats
Background/Aims: Stress had been related to physiological and morphological alterations in different organs, however kidney morphology and function after stress conditions are not well-known. To evaluate the effects of chronic stress on renal morphology in prepubertal and adult rats, and to investigate if the effects of induced stress remain stable or worsen following removal of the stress stimuli. Methods: Forty prepubertal rats (4 weeks old) and thirty six adult rats (10 weeks old) were used. Each age group was divided a into control group and a stressed group. Stressed animals were restrained in rigid tubes 2 hours per day for 6 weeks. Animals were euthanized 24 hours after the last stress stimulus for immediate evaluation (50% of the groups), and 6 weeks after the last stress stimulus for late evaluation (50% of the groups). Kidney weight and volume, cortical-medullar ratio, glomerular volumetric density, volume-weighted glomerular volume, and number of glomeruli per kidney were evaluated using the Image J software. Results: Prepubertal stressed animals showed reduced kidney weight and volume, and increased cortical-medullar ratio in comparison to its control group when evaluated immediately. Furthermore, stressed prepubertal and adult animals evaluated immediately had reduced glomerular volumetric density. Most importantly, all stressed groups exhibited reduced number of glomeruli per kidney. Other analyzed parameters did not difeer significantly the groups. Conclusion: Chronic stress induced before and after puberty led to irreversible glomerular loss, however, renal impairment was interrupted by removal of the stress stimuli
Effects of chronic restraint stress in the prostate of prepubertal and adult rats
ABSTRACT Purpose: To investigate the effects of chronic stress in the prostate of prepubertal and adult rats. Methods: Thirty-two male rats were assigned into four groups depending on the type of treatment (control or stressed) and the age at which stress was initiated (prepubertal or adult). Restraint stress stimuli were applied for six weeks. Stressed prepubertal and adult rats evaluated immediately after the last stress stimuli were named SP and SA groups, respectively. Age-matched rats were used as control groups (CP and CA). At the end of the experiment, the rats were euthanized, and prostate morphological parameters were evaluated and statistically compared. Results: Application of stress stimuli to the SP group resulted in reduced body weight, but no prostate morphological modification was noted. The SA group showed reduced testosterone level and prostatic epithelium surface density, in comparison to CA group. Further, the prostatic lumen surface density was increased in adult stressed animals, in comparison to adult controls. Conclusions: The stress stimuli promoted changes in hormonal and morphological parameters in the prostate of adult stressed rats. Prepubertal stressed animals did not presented modifications of prostate morphology
Experiência, teoria e ação : práticas pedagógicas de ensino de língua portuguesa
-Este livro apresenta ações pedagógicas de ensino de língua portuguesa e literatura implementadas no âmbito do Mestrado Profissional em Letras da Universidade Federal de Juiz de Fora. Em uma perspectiva de pesquisa ação, foram desenvolvidas intervenções em sala de aula de ensino básico, pautadas em abordagens teóricas recentes. As motivações, etapas de intervenção, bases teóricas, experiências e resultados das intervenções são expostos e discutidos na obra como forma de incentivar a replicação de ações exitosas de ensino de língua materna
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. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ
Morphological aspects of atrioventricular valves in the ostrich (Struthio camelus)
http://dx.doi.org/10.5007/2175-7925.2013v26n4p203Heart anatomy in the ostrich has been reported, but there are few information on the histological features of the atrioventricular valves. Hearts of young ostriches were fixed in 10% formaldehyde for 24 h and dissected to characterize their macroscopic anatomy. Samples of valves were harvested and stained with Mallory’s trichrome, Gomori’s trichrome, and Picro-Sirius red, for later analysis. The right atrioventricular valve consists of a muscle flap with two fixations. The left atrioventricular valve consists of two layers of endocardium with a layer of connective tissue between them. The free border of the tricuspid valve supports a varying number of chordae tendineae. One of the cusps is attached to the septum, while the other two cusps are attached to the opposite wall. The aortic valve, as well as the pulmonary trunk valve, consists of three cusps. The right atrioventricular valve showed up only as a muscle flap of myocardium coated with a thin layer of dense connective tissue, with two fixations. In the connective tissue, we find a predominance of type I collagen fibers and a lesser amount of type III, with a small presence of elastic fibers. The presence of Purkinje fibers were also usual in the valvular subendocardium, suggesting that they directly participate in the transmission of nervous stimulation to the muscle fibers within the valves. The left atrioventricular valve consisted of 3 cusps, a dorsal, a left, and a right.
A EVOLUÇÃO DA PAISAGEM APLICADA NA INTERPRETAÇÃO DE TRILHAS, NO PARQUE NACIONAL DA SERRA DOS ÓRGÃOS (PARNASO-RJ)
A interpretação da natureza, contida nos programas de Uso Público e Educação
Ambiental em Unidades de Conservação, visa traduzir a linguagem técnica
das ciências naturais para uma linguagem inteligível ao público em geral,
realizando-a de forma lúdica e criativa, sendo parte integrante dos programas
de Uso Público e Educação Ambiental em Unidades de Conservação. Ela deve
trazer para o usuário uma nova visão sobre o ambiente visitado, relacionando
aspectos da paisagem com temáticas voltadas para a valorização e conservação
ambiental. Esse artigo refere-se ao conceito de criação de um roteiro
interpretativo, envolvendo oito trilhas e um recanto do Parque Nacional da
Serra dos Órgãos (PARNASO-RJ). Por meio de um tema central elaborado para
a interpretação ambiental, os usuários são estimulados a refletirem sobre a
“evolução da paisagem”, agregando valor à experiência turística e estimulando
a conscientização ambiental nessa unidade de conservação. Dessa forma, os
visitantes podem perceber as intrincadas relações ecológicas e interfaces entre
o homem e a natureza, revelando a importância do PARNASO como uma área
núcleo integrante do corredor central da Mata Atlântica, fundamental para a
conservação desse bioma