Evolutionary processes and its environmental correlates in the cranial morphology of western chipmunks (Tamias).

The importance of the environment in shaping phenotypic evolution lies at the core of evolutionary biology. Chipmunks of the genus Tamias (subgenus Neotamias) are part of a very recent radiation, occupying a wide range of environments with marked niche partitioning among species. One open question is if and how those differences in environments affected phenotypic evolution in this lineage. Herein we examine the relative importance of genetic drift versus natural selection in the origin of cranial diversity exhibited by clade members. We also explore the degree to which variation in potential selective agents (environmental variables) are correlated with the patterns of morphological variation presented. We found that genetic drift cannot explain morphological diversification in the group, thus supporting the potential role of natural selection as the predominant evolutionary force during Neotamias cranial diversification, although the strength of selection varied greatly among species. This morphological diversification, in turn, was correlated with environmental conditions, suggesting a possible causal relationship. These results underscore that extant Neotamias represent a radiation in which aspects of the environment might have acted as the selective force driving species' divergence

Influence of bunch exposure on anthocyanins extractability from grapes skins (Vitis vinifera L.)

In relation to bunch exposure to solar irradiance (sun exposed vs. leaf shaded conditions), anthocyanin ripening and extractability were studied in two grape cultivars ('Croatina' and 'Pinot Noir') coming from three different vineyards in Northern Italy. Analysis of anthocyanin content were carried out by HPLC and spectrophotometry, and a simulated maceration process was developed. Pigments extraction occurred mainly in the first few hours of the maceration process. Anthocyanins with disubstituted B-ring showed a faster extractability than the trisubsituted ones. Bunch exposure to sunlight seemed to be important for pigment extractability timing in winemaking, showing a delay in pigments release. This delay was only partially explained by the different pigments profile, with higher percentage of disubstituted compounds in shaded berries, because all the molecules indicated a similar extraction trend during maceration.

Campos Organizacionais: Seis Diferentes Leituras e a Perspectiva de Estruturação

The concept of the organizational field has been greatly dealt with in the literature on institutional theory in recent years. As the concept of field involves a relational and symbolic dimension, we propose that the theory of structuration, based on the logic of recursiveness between agency and structure should be adapted to the understanding of the field dynamically. In this way, the objective of this theoretical essay is to deal with the dynamic of the organizational field using structurationist logic, allowing that from this logic we recall both the importance of the practice in the structuration process of the organizational field and the historical and recursive character which may constrain or enable the actions of social actors. To this end, we revise the concept of field in different perspectives of analysis, reflecting on the implication of the theoretical presuppositions of each approach and then discuss in a critical manner the theoretical foundation of the structuration process of organizational fields based on the structurationist approach. We conclude the paper with propositions pertaining to the revision of the concept of field from a multiparadigmatic viewpoint in which structure and agency are recursively implied

Organizational Fields and the Structuration Perspective: Analytical Possibilities

The concept of the organizational field has been greatly dealt with in the literature on institutional theory in recent years. As the concept of field involves a relational and symbolic dimension, we propose that the theory of structuration, based on the logic of recursiveness between agency and structure should be adapted to theunderstanding of the field dynamically. In this way, the objective of this theoretical essay is to deal with the dynamic of the organizational field using structurationist logic, allowing that from this logic we recall both the importance of the practice in the structuration process of the organizational field and the historical and recursive character which may constrain or enable the actions of social actors. To this end, we revise the concept of field in different perspectives of analysis, reflecting on the implication of the theoretical presuppositions of each approach and then discuss in a critical manner the theoretical foundation of the structuration process of organizational fields based on the structurationist approach. We conclude the paper with propositions pertaining to the revision of the concept of field from a multiparadigmatic viewpoint in which structure and agency are recursively implied

Drag reduction by polyethylene glycol in the tail arterial bed of normotensive and hypertensive rats

This study was designed to evaluate the effect of drag reducer polymers (DRP) on arteries from normotensive (Wistar) and spontaneously hypertensive rats (SHR). Polyethylene glycol (PEG 4000 at 5000 ppm) was perfused in the tail arterial bed with (E+) and without endothelium (E-) from male, adult Wistar (N = 14) and SHR (N = 13) animals under basal conditions (constant flow at 2.5 mL/min). In these preparations, flow-pressure curves (1.5 to 10 mL/min) were constructed before and 1 h after PEG 4000 perfusion. Afterwards, the tail arterial bed was fixed and the internal diameters of the arteries were then measured by microscopy and drag reduction was assessed based on the values of wall shear stress (WSS) by computational simulation. In Wistar and SHR groups, perfusion of PEG 4000 significantly reduced pulsatile pressure (Wistar/E+: 17.5 ± 2.8; SHR/E+: 16.3 ± 2.7%), WSS (Wistar/E+: 36; SHR/E+: 40%) and the flow-pressure response. The E- reduced the effects of PEG 4000 on arteries from both groups, suggesting that endothelial damage decreased the effect of PEG 4000 as a DRP. Moreover, the effects of PEG 4000 were more pronounced in the tail arterial bed from SHR compared to Wistar rats. In conclusion, these data demonstrated for the first time that PEG 4000 was more effective in reducing the pressure-flow response as well as WSS in the tail arterial bed of hypertensive than of normotensive rats and these effects were amplified by, but not dependent on, endothelial integrity. Thus, these results show an additional mechanism of action of this polymer besides its mechanical effect through the release and/or bioavailability of endothelial factors

A Questão da Agência em Redes Acadêmicas de Pesquisa : Centralidade, Produtividade e Escolha

No presente artigo, investigamos o papel da agência na construção do conhecimento científico com base em pressupostos do estruturacionismo. Para tanto, a noção de agência foi empiricamente tratada a partir da análise de redes sociais, tendo como indicadores a centralidade, produtividade e escolha preferencial de pesquisadores do campo da pesquisa na área dos estudos organizacionais e da estratégia em organizações no Brasil. Foram considerados 2.332 artigos entre os anos de 1997 e 2005, por meio dos quais analisamos 2.072 pesquisadores. Destacamos o papel de alguns deles, classificados como continuantes, para avaliar mais detalhadamente indicadores estruturais, além da trajetória de sua produção acadêmica. Nossos achados permitem afirmar que não somente a estrutura social apresenta dualidade, condicionando e habilitando a ação, mas também a própria capacidade de agência. Vista correntemente na literatura como potencialmente transformadora, ela também condiciona a ação dos agentes, pois suas capacidades projetivas tendem a ser guiadas por condutas do passado, no sentido de vincular suas ações à trajetória social e intelectual vivida no campo, podendo acarretar maior conformidade e habitualidade na pesquisa. Denominamos esse fenômeno como paradoxo da capacidade de agência, pois a mesma via que habilita a ação também a limita cognitivamente.In this article, we examine the role of the agency in the construction of scientific knowledge under the assumptions of structurationism. For this purpose, the notion of agency has been empirically treated from the social network analysis, with the indicators being the centrality, productivity and preferential attachment of researchers in the field of organizational studies and strategy in Brazil. We analyzed 2,072 researchers, in that we highlight the role of some of them, classified as continuants, in order to evaluate structural indicators in more detail, in addition to the trajectory of their academic production. Our findings allow us to affirm that it is not only the social structure that shows duality, conditioning and enabling the action, but also the capacity of agency itself. Currently viewed in the literature as a transforming capacity, it also conditions the action of agents because their projective capacities tend to be guided by past conduct in that they link their actions to the social and intellectual trajectory they have experienced in the field, bringing greater conformity and habitualness to research. We have addressed this phenomenon into a cognitive realm and have called it as paradox of agency capability

Institucionalismo Organizacional e Práticas de Governança Corporativa

In this essay, we outline an institutional approach concerning corporate governance, highlighting its dimensions, institutions, and institutionalization. Special attention is paid to the legitimizing quality of governance, since legitimacy is the central point in organizational institutionalism. The literature claims that the legitimacy of governance practices is based not only on rational-utilitarian questions but also on matters of social and symbolic order, e.g., the ideal of distributive justice, in which minority shareholders seek to justify greater control over controlling shareholders and managers guiding organizations on the morality of such requirements. We delineate some elements of the process of institutionalization of corporate governance practices around the world, noting that the emergence of the phenomenon and its spread is the result of several factors that end up pushing the product and capital markets to conform their practices to internationally prevailing standards. We conclude this theoretical essay by highlighting the implications for understanding the governance practices from the standpoint of organizational institutionalism, unfolding possibilities for future studies

ANÁLISE INSTITUCIONAL DA CONSTRUÇÃO DO CONHECIMENTO CIENTÍFICO EM MUNDOS PEQUENOS

O objetivo do presente artigo foi verificar como a estrutura de relacionamento no campo da pesquisa em organizações e estratégia no Brasil condiciona a construção do conhecimento científico nesse campo social. Por meio da análise de redes e com o apoio da análise de conteúdo, foram avaliados 2.332 artigos publicados entre os anos de 1997 e 2005. Com base na vertente estruturacionista da perspectiva institucional de análise examinamos a influência das relações entre autores na persistência e mudança de temáticas no decorrer do tempo. Verificamos que o campo apresenta uma configuração do tipo mundos pequenos (small worlds), o que lhe garante capacidade de persistência institucional em momentos de grande crescimento. Apesar da rede não ser completamente conectada, observamos alto grau de homogeneidade dentro dos agrupamentos mesmo em face da ocorrência de heterogeneidade de temas de pesquisa no campo como um todo. Tal constatação indica que a imersão em grupos sociais condiciona o que é legitimamente aceito no campo científico. A configuração estrutural nos moldes de mundos pequenos possibilita que o campo mantenha significados compartilhados, garantindo durabilidade dinâmica às instituições

Short communication: Characterization of a monoclonal antibody for κ-casein B of cow's milk1

A monoclonal antibody (antik-B) against an oligopeptide of 23 AA corresponding to the region 131-153 of bovine kappa-casein (kappa-CN) B was generated using the Human Combinatorial Antibody Library (HuCAL) technology. Both AA substitutions distinguishing kappa-CN A and B are located in that region (positions 136 and 148). In this study, the reactivity of antik-B to milk samples collected from cows previously genotyped as CSN3*AA, CSN3*AB, and CSN3*BB was tested. According to Western blot results, antik-B recognized kappa-CN B and it showed no cross-reactivity toward kappa-CN A and other milk proteins. Furthermore, a modified Western blot method, urea-PAGE Western blot, was set up to assess the reactivity of antik-B toward all isoforms of kappa-CN B. In conclusion, antik-B was specific to kappa-CN B in milk and it seemed to be reactive toward all its isoforms