Association Patterns in Saproxylic Insect Networks in Three Iberian Mediterranean Woodlands and Their Resistance to Microhabitat Loss

The assessment of the relationship between species diversity, species interactions and environmental characteristics is indispensable for understanding network architecture and ecological distribution in complex networks. Saproxylic insect communities inhabiting tree hollow microhabitats within Mediterranean woodlands are highly dependent on woodland configuration and on microhabitat supply they harbor, so can be studied under the network analysis perspective. We assessed the differences in interacting patterns according to woodland site, and analysed the importance of functional species in modelling network architecture. We then evaluated their implications for saproxylic assemblages’ persistence, through simulations of three possible scenarios of loss of tree hollow microhabitat. Tree hollow-saproxylic insect networks per woodland site presented a significant nested pattern. Those woodlands with higher complexity of tree individuals and tree hollow microhabitats also housed higher species/interactions diversity and complexity of saproxylic networks, and exhibited a higher degree of nestedness, suggesting that a higher woodland complexity positively influences saproxylic diversity and interaction complexity, thus determining higher degree of nestedness. Moreover, the number of insects acting as key interconnectors (nodes falling into the core region, using core/periphery tests) was similar among woodland sites, but the species identity varied on each. Such differences in insect core composition among woodland sites suggest the functional role they depict at woodland scale. Tree hollows acting as core corresponded with large tree hollows near the ground and simultaneously housing various breeding microsites, whereas core insects were species mediating relevant ecological interactions within saproxylic communities, e.g. predation, competitive or facilitation interactions. Differences in network patterns and tree hollow characteristics among woodland sites clearly defined different sensitivity to microhabitat loss, and higher saproxylic diversity and woodland complexity showed positive relation with robustness. These results highlight that woodland complexity goes hand in hand with biotic and ecological complexity of saproxylic networks, and together exhibited positive effects on network robustness.The research Projects I+D CGL2011-23658 y CGL2012-31669 of the Spanish Minister of Science provided economic support

The NOX toolbox: validating the role of NADPH oxidases in physiology and disease

Reactive oxygen species (ROS) are cellular signals but also disease triggers; their relative excess (oxidative stress) or shortage (reductive stress) compared to reducing equivalents are potentially deleterious. This may explain why antioxidants fail to combat diseases that correlate with oxidative stress. Instead, targeting of disease-relevant enzymatic ROS sources that leaves physiological ROS signaling unaffected may be more beneficial. NADPH oxidases are the only known enzyme family with the sole function to produce ROS. Of the catalytic NADPH oxidase subunits (NOX), NOX4 is the most widely distributed isoform. We provide here a critical review of the currently available experimental tools to assess the role of NOX and especially NOX4, i.e. knock-out mice, siRNAs, antibodies, and pharmacological inhibitors. We then focus on the characterization of the small molecule NADPH oxidase inhibitor, VAS2870, in vitro and in vivo, its specificity, selectivity, and possible mechanism of action. Finally, we discuss the validation of NOX4 as a potential therapeutic target for indications including stroke, heart failure, and fibrosis

Avicultura Industrial: Novos Conceitos de Materiais, Concepções e Técnicas Construtivas Disponíveis para Galpões Avícolas Brasileiros Industrial Aviculture: New Concepts of Materials, Conceptions and Constructive Techniques Available for Brazilian Poultry Houses

Ao grande crescimento das fronteiras mercadológicas e ao extraordinário progresso científico verificado na avicultura industrial, contrapõe-se a pouca atenção que se deu, até recentemente, às técnicas de alojamento e, efetivamente, ao ambiente de criação das aves. Somente há questão de sete anos, com a perspectiva do processo de globalização que hoje movimenta a economia mundial, essa indústria passou a buscar, nas instalações e no ambiente, as possibilidades de melhoria no desempenho avícola e a redução dos custos de produção como forma de manter a competitividade. A produção de aves em alta densidade passou a ser imperativa e, dessa forma, a exigência de conforto térmico ambiental, que já havia crescido muito com o aumento da precocidade das aves, tornou-se ainda maior, como conseqüência da elevação da densidade de alojamento. Assim, para se manter competitiva, a indústria avícola brasileira está tendo de evoluir, rapidamente, de uma situação de quase indiferença aos princípios do acondicionamento térmico ambiente, para uma situação em que cada empresa ou integração deve tomar decisões relativas à adoção de concepções arquitetônicas e manejos inovadores, associados a sistemas de acondicionamento térmico naturais e artificiais, compatíveis com a sua realidade. Essas decisões incluem a readequação dos galpões já existentes e a concepção de novas unidades. Seguramente, estamos vivendo o momento de mais intensas transformações dos alojamentos avícolas brasileiros até então presenciado. Do exposto, esse trabalho busca abordar o planejamento, a concepção arquitetônica e os diferentes materiais e técnicas construtivas disponíveis para a indústria avícola brasileira no que diz respeito aos galpões de alojamentos das aves, visando propiciar um melhor acondicionamento térmico ambiente, compatível com as diferentes regiões climáticas brasileiras.<br>To the great growth of the market and the extraordinary scientific progress verified in the Brazilian poultry industry, little attention was given, until recently, to the lodging techniques and, indeed, to the environment of growing birds. This is only a seven year-old subject, and with the perspective of the globalization process that today moves the world economy, this industry started to look for facilities and environment, seeking the improvement possibilities in the poultry activity and the reduction of the production costs as a form of maintaining the competitiveness. The high-density production of birds became imperative and, this way, the demand of environmental thermal comfort, which had already grown a lot with the increase of the precocity of the birds, became even larger, as a consequence of the increase of lodging density. Thus, to continue being competitive, the Brazilian poultry industry has to develop, as soon as possible, from the situation of almost indifference of the beginning of the thermal atmosphere conditioning, to a situation in which each company or integration should take its own decisions of adoption of architectural conceptions and innovations associated with systems of thermal, natural and artificial conditioning, compatible with its reality. Decisions that already include the modifications of the existing houses and the conception of new units. We are witnessing, for sure, the moment of more intense transformations of the Brazilian poultry lodgings. From what was exposed, this work intends to approach the planning, the architectural conception and the different materials and available constructive techniques for the Brazilian poultry industry that refers to the lodgings of the birds, seeking to propitiate a better conditioned thermal atmosphere, compatible with the different Brazilian climatic areas

Pushing it to the Limit: Adaptation with Dynamically Switching Gain Control

With this paper we propose a model to simulate the functional aspects of light adaptation in retinal photoreceptors. Our model, however, does not link specific stages to the detailed molecular processes which are thought to mediate adaptation in real photoreceptors. We rather model the photoreceptor as a self-adjusting integration device, which adds up properly amplified luminance signals. The integration process and the amplification obey a switching behavior that acts to shut down locally the integration process in dependence on the internal state of the receptor. The mathematical structure of our model is quite simple, and its computational complexity is quite low. We present results of computer simulations which demonstrate that our model adapts properly to at least four orders of input magnitude