17 research outputs found
Towards theorising assessment as critical inquiry
Throughout the past two decades assessment has operated on two fronts. First has been the continuing interest in large-scale, standardised testing, which affords governments and countries data for accountability and reporting purposes. Second has been the increasing interest in assessment within a learning culture (Shepard, 2000). Broadly speaking, this has concentrated on formative assessment for improving learning and has generated a proliferation of phrases seeking to highlight vital connections between assessment and learning (for example, 'assessment for/as learning'). Each of these fronts can be understood as giving priority to particular assessment activities and contexts. In the case of standardised testing, usually undertaken to generate data for systems' purposes, the context is necessarily controlled, with variables such as time and place fixed and regulated.Arts, Education & Law Group, School of Education and Professional StudiesFull Tex
A Genomic Regulatory Network for Development
Original article can be found at: http://www.sciencemag.org/ Copyright American Association for the Advancement of Science. [Full text of this article is not available in the UHRA]Development of the body plan is controlled by large networks of regulatory genes. A gene regulatory network that controls the specification of endoderm and mesoderm in the sea urchin embryo is summarized here. The network was derived from large-scale perturbation analyses, in combination with computational methodologies, genomic data, cis-regulatory analysis, and molecular embryology. The network contains over 40 genes at present, and each node can be directly verified at the DNA sequence level by cis-regulatory analysis. Its architecture reveals specific and general aspects of development, such as how given cells generate their ordained fates in the embryo and why the process moves inexorably forward in developmental time.Peer reviewe
Efeito do estresse térmico e do exercício sobre parâmetros fisiológicos de cavalos do exército brasileiro Effect of heat stress and exercise on physiological parameters of horses of the Brazilian army
Os cavalos do exército brasileiro são usados em dias de exposição e, muitas vezes, submetidos a exercício intenso, que, aliado às condições climáticas do cerrado do Centro-Oeste brasileiro, resulta na necessidade de extrema aclimatação dos mesmos. O objetivo desse estudo foi determinar o efeito do estresse térmico e do exercício a que estão submetidas às raças de eqüinos estudadas. Foram utilizados 40 cavalos adultos (4 a 13 anos) do 1º Regimento de Cavalaria de Guarda (10 animais de cada uma das raças Puro Sangue de Corrida - PSC, Mestiço <FONT FACE=Symbol>¾</FONT> M e Brasileiro de Hipismo - BH) e do 32º Grupo de Artilharia de Campanha (10 animais da raça Bretã), localizado no Setor Militar Urbano do Distrito Federal. Foram realizadas três medidas das freqüências cardíaca e respiratória, da temperatura retal e colhidas amostras de sangue quatro vezes por dia, de manhã e à tarde, antes e depois dos animais terem sido submetidos a exercício. A raça afetou todas as características exceto VCM, HCM e CHCM. Animais da raça PSC tiveram médias mais altas para leucócitos (7,83 ± 1,59), hemácias (9,21 ± 1,27), VG (40,75 ± 4,58) e hemoglobina (14,34 ± 1,67), enquanto os mestiços tiveram médias mais altas para proteína plasmática total (6,93 ± 0,66). Na raça Bretã foram observados níveis mais baixos para a maioria das características examinadas. O exercício afetou todas as características exceto VCM, HCM e CHCM com o nível das características aumentando em todos os casos. As correlações entre as características investigadas variam muito, sendo que entre hemácias, hemoglobina, VG foram em geral altas e positivas (>0,58), enquanto com a proteína plasmática total foram de médias a baixas (<0,26). O presente experimento nos permite concluir que os animais da raça PSC são os mais susceptíveis e os da raça Bretã os melhores adaptados às condições do clima do DF.<br>The horses of the Brazilian army are used for expositions, and frequently subjected to intense exercise. This, together with environmental conditions of the Central west savanna result in the need for acclimatization. The objective of this study was to determine what is the effect of thermal and exercise stress on four groups of stabled horses in the savanna region. 40 Adult horses (4 to 13 years of age) from the 1st Mounted Guard Regiment (10 of each breed Thoroughbred <FONT FACE=Symbol>¾</FONT> PSC, Crossbred <FONT FACE=Symbol>¾</FONT> M and Brazilian Showjumper <FONT FACE=Symbol>¾</FONT> BH) as well as 10 Bretãs from the 32nd Campaign Artillery Group, were used. All horses were kept in the Urban Military Sector in the Federal District. The measurements made on the animals included heart and respiratory rates, rectal temperature and blood samples were taken at four opportunities during the day, in the morning and afternoon, before and after exercise. Genetic group influenced all traits except VCM, HCM e CHCM. Animals of the PSC group had higher means for leukocytes (7.83 ± 1.59), hematocytes (9.21 ± 1.27), VG (40.75 ± 4.58) and hemoglobin (14.34 ± 1.67), while crossbreds had higher total plasmatic protein levels (6,93 ± 0,66). The Breton breed had lowest levels for the majority traits examined. Exercise increased all traits except VCM, HCM and CHCM. The correlations between traits vary greatly, the highest being between hematocytes, hemoglobin and VG (>0.58), while with total plasma protein they were low (<0.26). The present work allows us to conclude that in terms of exercise of horses of the Brazilian army PSC are worst adapted and Bretã best adapted to the conditions of this study
Radial Glia in Echinoderms
Radial glial cells are crucial in vertebrate neural development and regeneration. It has been recently proposed that this neurogenic cell type might be older than the chordate lineage itself and might have been present in the last common deuterostome ancestor. Here, we summarize the results of recent studies on radial glia in echinoderms, a highly regenerative phylum of marine invertebrates with shared ancestry to chordates. We discuss the involvement of these cells in both homeostatic neurogenesis and post-traumatic neural regeneration, compare the features of radial glia in echinoderms and chordates to each other, and review the molecular mechanisms that control differentiation and plasticity of the echinoderm radial glia. Overall, studies on echinoderm radial glia provide a unique opportunity to understand the fundamental biology of this cell type from evolutionary and comparative perspectives