As comunidades de anfíbios e lagartos dos remanescentes de restingas do estado do Espírito Santo: uma análise da ocorrência e distribuição das espécies

Ecologicamente, comunidades são conjuntos de populações convivendo no mesmo espaço e tempo. A forma como as espécies que compõem estas comunidades, como elas se distribuem e como estão estruturadas, depende de inúmeros fatores, entre eles históricos, biogeográficos e evolutivos. Neste estudo, buscamos compreender como as comunidades de anfíbios anuros e de lagartos estão estruturadas e quais fatores ambientais e de degradação são determinantes nesta estruturação. Amostramos cinco remanescentes de restinga no estado do Espírito Santo, utilizando método de procura ativa em transecções lineares nas diferentes fisionomias vegetais destes ecossistemas. Realizamos amostragens nas estações seca e de chuvas em todas as restingas, e somamos um total de 60 horas de esforço amostral para os anfíbios e 75 horas para os lagartos. Registramos um total de 32 espécies de anfíbios anuros conjuntamente nos cinco remanescentes de restinga, sendo duas destas espécies endêmicas deste ecossistema: Scinax agilis e Melanophryniscus setiba. A restinga do Parque Paulo Cesar Vinha foi o remanescente com a maior riqueza de espécies de anuros, enquanto a restinga da Reserva Biológica de Comboios foi, comparativamente, o remanescente com menor riqueza de espécies. Em termos de composição de espécies, as restingas de Praia das Neves e Paulo Cesar Vinha foram as mais similares, enquanto a restinga de Comboios foi a mais distante na análise de agrupamento. Registramos no conjunto de restingas seis modos reprodutivos para as espécies de anuros, sendo 75% deles relacionados aos ambientes aquáticos. A disponibilidade de locais de desova esteve positivamente relacionada à riqueza de espécies. Todos os mesohábitats das restingas, com exceção das fitofisionomias de halófila-psamófila, foram utilizados pelos indivíduos registrados, entretanto, uma porcentagem considerável dos indivíduos foi encontrada nos alagados. Em relação às comunidades de lagartos, adotamos além dos nossos dados, aqueles disponíveis em Dias e Rocha (2014) e aqueles disponíveis em Winck (2012). Registramos um total de 23 espécies de lagartos nos remanescentes de restinga amostrados nos estados do Rio de Janeiro, Espírito Santo e Bahia. Observamos que as comunidades presentes nos remanescentes estudados possuem considerável diferenciação entre elas. A diversidade beta (β) foi elevada enquanto o grau de aninhamento foi intermediário. Registramos ainda a presença do lagarto exótico invasor Hemidactylus mabouia em ambiente natural nos remanescentes de restinga estudados neste Tese. Encontramos 45 indivíduos, distribuídos em três dos cinco remanescentes amostrados. Registramos ainda ovos de H. mabouia (2 deles eclodidos) em dois dos cinco locais estudados, indicando que o recrutamento de indivíduos está ocorrendo com sucesso nas populações invasoras. A presença de H. mabouia esteve relacionada à restingas com maior frequência de degradação ambiental. Consideramos que os dados obtidos nesta tese, fornecem informações de considerável importância para o entendimento da estrutura das comunidades de anfíbios e lagartos nos ecossistemas de restinga ao longo da costa brasileira

Enzimas antioxidantes em sangue de peixes expostos à hipoxia e hiperoxia

O oxigênio é importante não só por sua participação no metabolismo energético, mas também por sua conversão em derivados parcialmente reduzidos, as espécies reativas de oxigênio (ERO). ERO participam de funções importantes em diversas vias do metabolismo, entretanto, em concentrações desequilibradamente elevadas deflagram a peroxidação lipídica, processo deletério que forma aldeídos tóxicos, como o 4-hidroxi-2-nonenal (4-HNE). A manutenção de concentrações não deletérias das ERO é realizada por moléculas componentes do sistema antioxidante. Peixes podem ser expostos a grandes variações das concentrações de oxigênio, o que provoca ciclos oxidantes. A maioria dos estudos usa fígado e rim para avaliar estresse oxidante por meio de ensaios das atividades antioxidantes, o que requer o sacrifício dos animais. Contudo, o sangue sofre efeitos das ERO e avaliações no sangue podem permitir o estudo de antioxidantes no mesmo animal, sem a necessidade de sacrifício. Em consequência, foram nossos objetivos estabelecer uma técnica de cateterismo branquial em peixes, a padronização dos ensaios e a avaliação em sangue de componentes do sistema antioxidante de duas espécies de teleósteos em diferentes tensões de oxigênio. Pacus e tilápias foram avaliados em 6,0 mg de O2.L-1 e em hipoxia a 0,5 mg de O2.L-1 por 42 horas . Para os ensaios de hiperoxia os animais foram avaliados em 6,0 mg de O2.L-1, depois de 6 horas em 9,5 mg de O2.L-1 e depois de 30 horas de recuperação a 6,0 mg de O2.L-1. A utilização de materiais para o cateterismo de humanos permitiu a implantação de um acesso branquial. Infelizmente, houve formação de trombo após 24 horas. Mesmo assim, a observação de fluxo sanguíneo no interior da cânula e a sobrevida dos animais testados, confirmam a viabilidade da técnica. Verificamos em sangue uma maior atividade da enzima glutationa S-transferase (GST) sobre o 4-HNE em relação ao 1-cloro-2-dinitrobenzeno (CDNB). Isto reflete a importância de avaliações de atividade de enzimas, como a GST, sobre substratos endógenos. As respostas enzimáticas de tilápias mostraram-se mais sensíveis que as dos pacus quando comparadas em diferentes tensões de oxigênio.

Scientific assessment of marine harmful algal blooms

Algae are the most abundant photosynthetic organisms in marine ecosystems and are essential components of marine food webs. Harmful algal bloom or “HAB” species are a small subset of algal species that negatively impact humans or the environment. HABs can pose health hazards for humans or animals through the production of toxins or bioactive compounds. They also can cause deterioration of water quality through the buildup of high biomass, which degrades aesthetic, ecological, and recreational values. Humans and animals can be exposed to marine algal toxins through their food, the water in which they swim, or sea spray. Symptoms from toxin exposure range from neurological impairment to gastrointestinal upset to respiratory irritation, in some cases resulting in severe illness and even death. HABs can also result in lost revenue for coastal economies dependent on seafood harvest or tourism, disruption of subsistence activities, loss of community identity tied to coastal resource use, and disruption of social and cultural practices. Although economic impact assessments to date have been limited in scope, it has been estimated that the economic effects of marine HABs in U.S. communities amount to at least $82 million per year including lost income for fisheries, lost recreational opportunities, decreased business in tourism industries, public health costs of illness, and expenses for monitoring and management. As reviewed in the report, Harmful Algal Research and Response: A Human Dimensions Strategy1, the sociocultural impacts of HABs may be significant, but remain mostly undocumented.

A new Lagrangian-Eulerian shell-fluid coupling algorithm based on level sets

We propose a computational method for the coupled simulation of a compressible flow interacting with a thin-shell structure undergoing large deformations. An Eulerian finite volume formulation is adopted for the fluid and a Lagrangian formulation based on subdivision finite elements is adopted for the shell response. The coupling between the fluid and the solid response is achieved via a novel approach based on level sets. The basic approach furnishes a general algorithm for coupling Lagrangian shell solvers with Cartesian grid based Eulerian fluid solvers. The efficiency and robustness of the proposed approach is demonstrated with a airbag deployment simulation. It bears emphasis that in the proposed approach the solid and the fluid components as well as their coupled interaction are considered in full detail and modeled with an equivalent level of fidelity without any oversimplifying assumptions or bias towards a particular physical aspect of the problem.

Changes in lipids of mussel during storage

Proximate composition, lipid and fatty acid components of dried mussel and changes in lipids during 1 year storage were studied. Male mussel contained lower fat contents and higher contents of polyunsaturated fatty acids of C20:5n-3, and C22:6n-3. High percentages of Cl6:1, Cl7:1, Cl8:3n-3, C20:3n-8 existed in NL and C!6:0, C18:0, Cl8:1n-9, C20:2n-6, C20:5n- 3, C22:6n-3 were very rich in PL. Triglycerides phosphatidylcholine, cholesterol were major components of mussel lipids. Free fatty acids (FFA) increased greatly and phospholipids decreased during storage, saturated fatty acids showed an increase trend and polyunsaturated fatty adds decreased differently. Dried mussels were vacuum packed and air packed and packaging methods had a great influence on the oxidation of mussellip,ids, indicating preference of vacuum packaging.

Soft turn-on of NPT IGBT under Active Voltage Control

In this paper the soft turn-on of NPT IGBT under Active Voltage Control (AVC) is presented. The AVC technique is able to control the IGBT switching trajectory according to a pre-defined reference signal generated by a FPGA chip. By applying a special designed reference signal at turn-on, the IGBT turn-on current overshoot and diode recovery can be optimized. Experiments of soft turn-on with different reference signal are presented in this paper. This technique can be used to reduce the switching stress on the device and on other components of the circuit. © 2011 IEEE.

The effect of a twin tunnel on the propagation of ground-borne vibration from an underground railway

Accurate predictions of ground-borne vibration levels in the vicinity of an underground railway are greatly sought after in modern urban centres. Yet the complexity involved in simulating the underground environment means that it is necessary to make simplifying assumptions about this system. One such commonly made assumption is to ignore the effects of neighbouring tunnels, despite the fact that many underground railway lines consist of twin-bored tunnels, one for the outbound direction and one for the inbound direction. This paper presents a unique model for two tunnels embedded in a homogeneous, elastic fullspace. Each of these tunnels is subject to both known, dynamic train forces and dynamic cavity forces. The net forces acting on the tunnels are written as the sum of those tractions acting on the invert of a single tunnel, and those tractions that represent the motion induced by the neighbouring tunnel. By apportioning the tractions in this way, the vibration response of a two-tunnel system is written as a linear combination of displacement fields produced by a single-tunnel system. Using Fourier decomposition, forces are partitioned into symmetric and antisymmetric modenumber components to minimise computation times. The significance of the interactions between two tunnels is quantified by calculating the insertion gains, in both the vertical and horizontal directions, that result from the existence of a second tunnel. The insertion-gain results are shown to be localised and highly dependent on frequency, tunnel orientation and tunnel thickness. At some locations, the magnitude of these insertion gains is greater than 20 dB. This demonstrates that a high degree of inaccuracy exists in any surface vibration prediction model that includes only one of the two tunnels. This novel two-tunnel solution represents a significant contribution to the existing body of research into vibration from underground railways, as it shows that the second tunnel has a significant influence on the accuracy of vibration predictions for underground railways. © 2011 Elsevier Ltd. All rights reserved.

Regulation: A Burden in Biopharmaceutical Industry? The Case of EU-Risk Management Plans

The generation of new medicinal products is both a contributor to global economic growth and a source of valuable benefits to human health. Given their direct responsibility for public health, regulatory authorities monitor closely both the development and exploitation of the underlying technologies and the products derived from them. The manner in which such regulation is implemented can result in regulators constraining or facilitating the generation of new products. This paper will study as an example the impact of EU Risk Management Plans (EU-RMPs), which have been mandatory for the approval of new medicines since 2005, on both the industry and regulatory authorities. In interviews, the responses of those who had experience of the implementation of EU-RMPs were mixed. Although the benefits of a more structured and predictable approach to the evaluation of risk were appreciated, some respondents perceived the regulation as an excessive burden on their organisations. The exploration of factors that influence how EU-RMP regulation affects individual firms provides new insights for both regulators and managers, and demonstrates one aspect of the complexity of the process by which new medicinal products are brought to market.

Regulation: A burden in biopharmaceutical industry? The case of EU-risk management plans

The generation of new medicinal products is both a contributor to global economic growth and a source of valuable benefits to human health. Given their direct responsibility for public health, regulatory authorities monitor closely both the development and exploitation of the underlying technologies and the products derived from them. The manner in which such regulation is implemented can result in regulators constraining or facilitating the generation of new products. This paper will study as an example the impact of EU Risk Management Plans (EU-RMPs), which have been mandatory for the approval of new medicines since 2005, on both the industry and regulatory authorities. In interviews, the responses of those who had experience of the implementation of EU-RMPs were mixed. Although the benefits of a more structured and predictable approach to the evaluation of risk were appreciated, some respondents perceived the regulation as an excessive burden on their organisations. The exploration of factors that influence how EU-RMP regulation affects individual firms provides new insights for both regulators and managers, and demonstrates one aspect of the complexity of the process by which new medicinal products are brought to market. © 2010 IEEE.

Technology confidence in early stage development of medical devices

Innovation is a critical factor in ensuring commercial success within the area of medical technology. Biotechnology and Healthcare developments require huge financial and resource investment, in-depth research and clinical trials. Consequently, these developments involve a complex multidisciplinary structure, which is inherently full of risks and uncertainty. In this context, early technology assessment and 'proof of concept' is often sporadic and unstructured. Existing methodologies for managing the feasibility stage of medical device development are predominantly suited to the later phases of development and favour detail in optimisation, validation and regulatory approval. During these early phases, feasibility studies are normally conducted to establish whether technology is potentially viable. However, it is not clear how this technology viability is currently measured. This paper aims to redress this gap through the development of a technology confidence scale, as appropriate explicitly to the feasibility phase of medical device design. These guidelines were developed from analysis of three recent innovation studies within the medical device industry.

Recycle of transuranium elements in light water reactors for reduction of geological storage requirements

This paper presents results of a feasibility study aimed at developing a zero-transuranic-discharge fuel cycle based on the U-Th-TRU ternary cycle. The design objective is to find a fuel composition (mixture of thorium, enriched uranium, and recycled transuranic components) and fuel management strategy resulting in an equilibrium charge-discharge mass flow. In such a fuel cycle scheme, the quantity and isotopic vector of the transuranium (TRU) component is identical at the charge and discharge time points, thus allowing the whole amount of the TRU at the end of the fuel irradiation period to be separated and reloaded into the following cycle. The TRU reprocessing activity losses are the only waste stream that will require permanent geological storage, virtually eliminating the long-term radiological waste of the commercial nuclear fuel cycle. A detailed three-dimensional full pressurized water reactor (PWR) core model was used to analyze the proposed fuel composition and management strategy. The results demonstrate the neutronic feasibility of the fuel cycle with zero-TRU discharge. The amount of TRU and enriched uranium loaded reach equilibrium after about four TRU recycles. The reactivity coefficients were found to be within a range typical for a reference PWR core. The soluble boron worth is reduced by a factor of ∼2 from a typical PWR value. Nevertheless, the results indicate the feasibility of an 18-month fuel cycle design with an acceptable beginning-of-cycle soluble boron concentration even without application of burnable poisons.

Modeling sub-threshold current-voltage characteristics in thin film transistors

In this paper, we present a physically-based compact model for the sub-threshold behavior in a TFT with an amorphous semiconductor channel. Both drift and diffusion current components are considered and combined using an harmonic average. Here, the diffusion component describes the exponential current behavior due to interfacial deep states, while the drift component is associated with presence of localized deep states formed by dangling bonds broken from weak bonds in the bulk and follows a power law. The proposed model yields good agreement with measured results. © 2013 IEEE.

Solar UV radiation drives CO2 fixation in marine phytoplankton: A double-edged sword

Photosynthesis by phytoplankton cells in aquatic environments contributes to more than 40% of the global primary production (Behrenfeld et al., 2006). Within the euphotic zone (down to 1% of surface photosynthetically active radiation [PAR]), cells are exposed not only to PAR (400-700 nm) but also to UV radiation (UVR; 280-400 nm) that can penetrate to considerable depths (Hargreaves, 2003). In contrast to PAR, which is energizing to photosynthesis, UVR is usually regarded as a stressor (Hader, 2003) and suggested to affect CO2-concentrating mechanisms in phytoplankton (Beardall et al., 2002). Solar UVR is known to reduce photosynthetic rates (Steemann Nielsen, 1964; Helbling et al., 2003), and damage cellular components such as D1 proteins (Sass et al., 1997) and DNA molecules (Buma et al., 2003). It can also decrease the growth (Villafane et al., 2003) and alter the rate of nutrient uptake (Fauchot et al., 2000) and the fatty acid composition (Goes et al., 1994) of phytoplankton. Recently, it has been found that natural levels of UVR can alter the morphology of the cyanobacterium Arthrospira (Spirulina) platensis (Wu et al., 2005b). On the other hand, positive effects of UVR, especially of UV- A (315-400 nm), have also been reported. UV- A enhances carbon fixation of phytoplankton under reduced (Nilawati et al., 1997; Barbieri et al., 2002) or fast-fluctuating (Helbling et al., 2003) solar irradiance and allows photorepair of UV- B-induced DNA damage (Buma et al., 2003). Furthermore, the presence of UV-A resulted in higher biomass production of A. platensis as compared to that under PAR alone (Wu et al., 2005a). Energy of UVR absorbed by the diatom Pseudo-nitzschia multiseries was found to cause fluorescence (Orellana et al., 2004). In addition, fluorescent pigments in corals and their algal symbiont are known to absorb UVR and play positive roles for the symbiotic photosynthesis and photoprotection (Schlichter et al., 1986; Salih et al., 2000). However, despite the positive effects that solar UVR may have on aquatic photosynthetic organisms, there is no direct evidence to what extent and howUVR per se is utilized by phytoplankton. In addition, estimations of aquatic biological production have been carried out in incubations considering only PAR (i. e. using UV-opaque vials made of glass or polycarbonate; Donk et al., 2001) without UVR being considered (Hein and Sand-Jensen, 1997; Schippers and Lurling, 2004). Here, we have found that UVR can act as an additional source of energy for photosynthesis in tropical marine phytoplankton, though it occasionally causes photoinhibition at high PAR levels. While UVR is usually thought of as damaging, our results indicate that UVR can enhance primary production of phytoplankton. Therefore, oceanic carbon fixation estimates may be underestimated by a large percentage if UVR is not taken into account.

Spin Hall effect on the kagome lattice with Rashba spin-orbit interaction

We study the spin Hall effect in the kagome lattice with Rashba spin-orbit coupling. The conserved spin Hall conductance sigma(s)(xy) (see text) and its two components, i.e., the conventional term sigma(s0)(xy) and the spin-torque-dipole term sigma(s tau)(xy), are numerically calculated, which show a series of plateaus as a function of the electron Fermi energy epsilon(F). A consistent two-band analysis, as well as a Berry-phase interpretation, is also given. We show that these plateaus are a consequence of various Fermi-surface topologies when tuning epsilon(F). In particular, we predict that compared to the case with the Fermi surface encircling the Gamma point in the Brillouin zone, the amplitude of the spin Hall conductance with the Fermi surface encircling the K points is twice enhanced, which makes it highly meaningful in the future to systematically carry out studies of the K-valley spintronics.

Suppression of self-sustained field domain oscillation in GaAs/AlAs superlattice by hydrostatic pressure at room temperature

The behavior of room temperature self-sustained current oscillations resulting from sequential resonance tunneling in a doped weakly-coupled GaAs/AlAs superlattice (SL) is investigated under hydrostatic pressure. From atmosphere pressure to 6.5 kbar, oscillations exist in the whole plateau of the I-V curve and oscillating characteristics are affected by the pressure. When hydrostatic pressure is higher than 6.5 kbar, the current oscillations are completely suppressed although a current plateau still can be seen in the I-V curve. The plateau disappears when the pressure is close to 13.5 kbar. As the main effect of hydrostatic pressure is to lower the X point valley with respect to Gamma point valley, the disappearance of oscillation and the plateau shrinkage before Gamma - X resonance takes place are attributed to the increases of thermoionic emission and nonresonant tunneling components determined by the lowest Gamma - X barrier height in GaAs/AlAs SL structure.