Using Social Network Analysis to Improve Communities of Practice

PublishedThis is the final version of the article. Available from University of California Press via the DOI in this record.n/

Material alternativo para confecção de filtros empregados na metodologia "Nylon bag" para a determinação de fibra.

Teores de fibra em detergente neutro (FDN) e fibra em detergente ácido (FDA) em milho, soja, farelo de trigo, capins, feno, silagens, fezes e conteúdo duodenal de bovinos, foram determinados em analisador de fibra ANKOM 220, empregando saquinhos de polipropileno (TNT ? Tecido Não Tecido) confeccionados no laboratório, como material alternativo aos filtros fabricados e comercializados pela ANKOM. As análises foram conduzidas no Laboratório de Nutrição Animal da Embrapa Pecuária Sudeste, São Carlos - SP. Em um primeiro ensaio, os dois materiais foram comparados. O delineamento experimental foi inteiramente casualizado, em esquema fatorial 6 x 2 (seis amostras e dois tipos de saquinho), com três repetições. Em um segundo ensaio, amostras de referência foram usadas para confirmar a eficiência dos saquinhos de TNT. Para tal, foram avaliados o efeito da massa de amostra (0,5 e 0,25 mg) nos teores de FDN e FDA e o emprego de a amilase nos resultados de FDN. O delineamento experimental foi inteiramente casualizado em esquema fatorial 5 x 4 (cinco fatores e 4 amostras), com três repetições. Não foram observadas diferenças significativas (P > 0,05) entre os resultados obtidos com o emprego deste material em comparação aos filtros ANKOM. Os fatores variação de massa de amostra e adição de a amilase não tiveram efeito sobre os teores de FDN e FDA (P > 0,05). O TNT apresentou características favoráveis e promissoras ao seu uso, como baixo custo, rigidez e baixa porosidade

The autonomy of the contracting partner. An argument for heuristic contractarian business ethics

Due to the domain characteristics of business ethics, a contractarian theory for business ethics will need to be essentially different from the contract model as it is applied to other domains. Much of the current criticism of contractarian business ethics (CBE) can be traced back to autonomy, one of its three boundary conditions. After explaining why autonomy is so important, this article considers the notion carefully vis à vis the contracting partners in the contractarian approaches in business ethics. Autonomy is too demanding a condition for the realm of CBE. But a less stringent version of the contract may be possible, a version which uses the contract as a heuristic device, which merely requires moral responsibility. Furthermore, it is argued that views of (human) agency and the moral subject should be made explicit in such a theory. © Springer 2006

Observational constraints on Rastall's cosmology

Rastall's theory is a modification of General Relativity, based on the non-conservation of the stress-energy tensor. The latter is encoded in a parameter $\gamma$ such that $\gamma = 1$ restores the usual $\nabla_\nu T^{\mu\nu} = 0$ law. We test Rastall's theory in cosmology, on a flat Robertson-Walker metric, investigating a two-fluid model and using the type Ia supernovae Constitution dataset. One of the fluids is pressureless and obeys the usual conservation law, whereas the other is described by an equation of state $p_x = w_x\rho_x$, with $w_x$ constant. The Bayesian analysis of the Constitution set does not strictly constrain the parameter $\gamma$ and prefers values of $w_x$ close to -1. We then address the evolution of small perturbations and show that they are dramatically unstable if $w_x \neq -1$ and $\gamma \neq 1$, i.e. General Relativity is the favored configuration. The only alternative is $w_x = -1$, for which the dynamics becomes independent from $\gamma$.Comment: Latex file, 14 pages, 6 figures in eps format. Substantial modifications performed, main conclusions change

Spermidine protects from age-related synaptic alterations at hippocampal mossy fiber-CA3 synapses

Aging is associated with functional alterations of synapses thought to contribute to age-dependent memory impairment (AMI). While therapeutic avenues to protect from AMI are largely elusive, supplementation of spermidine, a polyamine normally declining with age, has been shown to restore defective proteostasis and to protect from AMI in Drosophila. Here we demonstrate that dietary spermidine protects from age-related synaptic alterations at hippocampal mossy fiber (MF)-CA3 synapses and prevents the aging-induced loss of neuronal mitochondria. Dietary spermidine rescued age-dependent decreases in synaptic vesicle density and largely restored defective presynaptic MF-CA3 long-term potentiation (LTP) at MF-CA3 synapses (MF-CA3) in aged animals. In contrast, spermidine failed to protect CA3-CA1 hippocampal synapses characterized by postsynaptic LTP from age-related changes in function and morphology. Our data demonstrate that dietary spermidine attenuates age-associated deterioration of MF-CA3 synaptic transmission and plasticity. These findings provide a physiological and molecular basis for the future therapeutic usage of spermidine

Managerial Work in a Practice-Embodying Institution - The role of calling, the virtue of constancy

What can be learned from a small scale study of managerial work in a highly marginal and under-researched working community? This paper uses the ‘goods-virtues-practices-institutions’ framework to examine the managerial work of owner-directors of traditional circuses. Inspired by MacIntyre’s arguments for the necessity of a narrative understanding of the virtues, interviews explored how British and Irish circus directors accounted for their working lives. A purposive sample was used to select subjects who had owned and managed traditional touring circuses for at least 15 years, a period in which the economic and reputational fortunes of traditional circuses have suffered badly. This sample enabled the research to examine the self-understanding of people who had, at least on the face of it, exhibited the virtue of constancy. The research contributes to our understanding of the role of the virtues in organizations by presenting evidence of an intimate relationship between the virtue of constancy and a ‘calling’ work orientation. This enhances our understanding of the virtues that are required if management is exercised as a domain-related practice