Distribuição e abundância do coral invasor Tubastraea spp.

As espécies de corais invasores, Tubastraea tagusensis e T. coccinea foram acidentalmente introduzidos no Brasil através de plataformas de petróleo. O rápido crescimento e estágio reprodutivo, competição contra espécies nativas, defesas químicas contra predadores e competidores naturais e uso amplo em diferentes substratos utilizados contribuem para o sucesso e expansão de Tubastraea spp. na costa brasileira. O presente estudo teve dois objetivos principais: 1) investigar uma metodologia que resulte em uma maior eficiência e custo-benefício nos processsos de monitoramento dos corais invasores Tubastraea spp. no litoral brasileiro; 2) mapear a distribuição geográfica, caracterizar as populações e estudar o efeito da inserção dos corais na comunidade bêntica de costões rochosos do litoral norte do estado de São Paulo (LNSP). O primeiro avaliou quatro metodologias, comparando o método do censo visual, e outras três metodologias que utilizam fotografia e filmagem. O método do censo visual mostrou ser mais eficiente na obtenção dos resultados quando comparado com os outros métodos, principalmente para identificar pequenos organismos. Contudo, seu tempo em campo e seus custos foram maiores. O segundo utilizou o método visual para estudar o efeito da inserção dos corais invasores na comunidade local do LNSP. Ainda, foi realizado um monitoramento espacial semi-quantitativo em larga escala para caracterizar a distribuição espacial dos corais invasores; transectos com quadrados amostrais foram usados para estimar a densidade de Tubastraea ao longo da profundidade, e transectos e arcos graduados empregados para estimar a ocorrência de colônias em diferentes inclinações do substrato, no LNSP. Os corais invasores estão aumentado sua distribuição, causando diversos impactos nas comunidades e nos organismos nativos. T. tagusensis é comumente encontrado dominando diversos costões rochosos, com uma densidade maior em ambientes mais profundos e com maior ocorência em substratos de inclinções verticais e negativas no LNSP. A erradicação e/ou controle do coral invasor é recomendado no litoral brasileiro, principalmente onde as populações estão isoladas ou ainda são pequenas.

Mode competition in acousto-optically Q-switched planar waveguide lasers

Multi-mode rate equations have been developed to investigate mode competition in high-power acousto-optically Q-switched planar waveguide lasers. The mode competition arises from coupling effects and temporal losses in the transform between guided modes and free-space propagation. Pulse-to-pulse instability and temporal beam distortions are enlarged by mode competition when the laser works in the multi-mode regime. The influence of parasitic oscillation is also discussed. A Nd:YAG planar waveguide laser has been established with a folded hybrid/unstable resonator. A maximum average power of 83 W with a beam propagation factor M-x(2) x M-y(2) = 1.2 x 1.4 is obtained. The theoretical simulation agrees well with the experimental observation. (c) 2006 Elsevier Ltd. All rights reserved.

Community Turnover of Wood-Inhabiting Fungi across Hierarchical Spatial Scales

For efficient use of conservation resources it is important to determine how species diversity changes across spatial scales. In many poorly known species groups little is known about at which spatial scales the conservation efforts should be focused. Here we examined how the community turnover of wood-inhabiting fungi is realised at three hierarchical levels, and how much of community variation is explained by variation in resource composition and spatial proximity. The hierarchical study design consisted of management type (fixed factor), forest site (random factor, nested within management type) and study plots (randomly placed plots within each study site). To examine how species richness varied across the three hierarchical scales, randomized species accumulation curves and additive partitioning of species richness were applied. To analyse variation in wood-inhabiting species and dead wood composition at each scale, linear and Permanova modelling approaches were used. Wood-inhabiting fungal communities were dominated by rare and infrequent species. The similarity of fungal communities was higher within sites and within management categories than among sites or between the two management categories, and it decreased with increasing distance among the sampling plots and with decreasing similarity of dead wood resources. However, only a small part of community variation could be explained by these factors. The species present in managed forests were in a large extent a subset of those species present in natural forests. Our results suggest that in particular the protection of rare species requires a large total area. As managed forests have only little additional value complementing the diversity of natural forests, the conservation of natural forests is the key to ecologically effective conservation. As the dissimilarity of fungal communities increases with distance, the conserved natural forest sites should be broadly distributed in space, yet the individual conserved areas should be large enough to ensure local persistence.

Structural Synthesis of 3-DoF Spatial Fully Parallel Manipulators

In this paper, the architectures of three degrees of freedom (3-DoF) spatial, fully parallel manipulators (PMs), whose limbs are structurally identical, are obtained systematically. To do this, the methodology followed makes use of the concepts of the displacement group theory of rigid body motion. This theory works with so-called 'motion generators'. That is, every limb is a kinematic chain that produces a certain type of displacement in the mobile platform or end-effector. The laws of group algebra will determine the actual motion pattern of the end-effector. The structural synthesis is a combinatorial process of different kinematic chains' topologies employed in order to get all of the 3-DoF motion pattern possibilities in the end-effector of the fully parallel manipulator.

Modelling Lipid Competition Dynamics in Heterogeneous Protocell Populations

Recent experimental work in the field of synthetic protocell biology has shown that prebiotic vesicles are able to 'steal' lipids from each other. This phenomenon is driven purely by asymmetries in the physical state or composition of the vesicle membranes, and, when lipid resource is limited, translates directly into competition amongst the vesicles. Such a scenario is interesting from an origins of life perspective because a rudimentary form of cell-level selection emerges. To sharpen intuition about possible mechanisms underlying this behaviour, experimental work must be complemented with theoretical modelling. The aim of this paper is to provide a coarse-grain mathematical model of protocell lipid competition. Our model is capable of reproducing, often quantitatively, results from core experimental papers that reported distinct types vesicle competition. Additionally, we make some predictions untested in the lab, and develop a general numerical method for quickly solving the equilibrium point of a model vesicle population.

Spatial-temporal excess mortality patterns of the 1918-1919 influenza pandemic in Spain

Background: The impact of socio-demographic factors and baseline health on the mortality burden of seasonal and pandemic influenza remains debated. Here we analyzed the spatial-temporal mortality patterns of the 1918 influenza pandemic in Spain, one of the countries of Europe that experienced the highest mortality burden. Methods: We analyzed monthly death rates from respiratory diseases and all-causes across 49 provinces of Spain, including the Canary and Balearic Islands, during the period January-1915 to June-1919. We estimated the influenza-related excess death rates and risk of death relative to baseline mortality by pandemic wave and province. We then explored the association between pandemic excess mortality rates and health and socio-demographic factors, which included population size and age structure, population density, infant mortality rates, baseline death rates, and urbanization. Results: Our analysis revealed high geographic heterogeneity in pandemic mortality impact. We identified 3 pandemic waves of varying timing and intensity covering the period from Jan-1918 to Jun-1919, with the highest pandemic-related excess mortality rates occurring during the months of October-November 1918 across all Spanish provinces. Cumulative excess mortality rates followed a south-north gradient after controlling for demographic factors, with the North experiencing highest excess mortality rates. A model that included latitude, population density, and the proportion of children living in provinces explained about 40% of the geographic variability in cumulative excess death rates during 1918-19, but different factors explained mortality variation in each wave. Conclusions: A substantial fraction of the variability in excess mortality rates across Spanish provinces remained unexplained, which suggests that other unidentified factors such as comorbidities, climate and background immunity may have affected the 1918-19 pandemic mortality rates. Further archeo-epidemiological research should concentrate on identifying settings with combined availability of local historical mortality records and information on the prevalence of underlying risk factors, or patient-level clinical data, to further clarify the drivers of 1918 pandemic influenza mortality.

Esporte como experiência : uma análise fenomenológico-pragmática da Constituição do jogo coletivo

O objetivo desse trabalho é compreender a ação humana nos jogos esportivos coletivos. Os jogos em questão são aqueles que são disputados em interações conduzidas pelos jogadores em ações simultâneas mutuamente referidas que envolvem o corpo em um mesmo ambiente ? geralmente esportes com bola, como o futebol, o basquetebol e o voleibol, entre outros. A perspectiva adotada nos conduziu no sentido de compreender a ação no curso da experiência de jogar, uma experiência comumente retratada por praticantes como uma experiência desafiadora, excitante, arrebatadora e autêntica. A realização da ação adequada à lógica dos eventos no sentido de propiciar o alcance das metas e objetivos propostos pelo jogo aos jogadores e à sua equipe, com uma organização e sentido de desafio, conduz e ordena todo o curso da experiência competitiva até o fim da partida ocasionando aquela experiência. Como isso é possível? Para tentar entender como ação e experiência se articulam em uma vivência singular, distinta das demais, na prática dos esportes coletivos, devemos compreender toda a ordem presente na própria constituição do desafio que caracteriza todo o jogo ? uma ordem prática que confere ao ser um impulso contínuo e arrebatador à ação. O jogo, desse modo, é apresentado aqui como um mundo a que corresponde toda uma ordem de existência. Esse mundo, em relação ao qual um modo agonistico de ser se alinha, é ordenado por um conjunto de regras que determina a forma lógica básica da prática competitiva. No modo como foi subjetivada e incorporada pelos jogadores em suas competências, essa forma ordena as interações permitindo que uma dinâmica competitiva real se desdobre fluentemente entre eles numa mesma corrente simultânea e sequencial de eventos que envolvem a todos, sendo vivenciada por cada um no mesmo tempo e no mesmo espaço de uma experiência competitiva nossa. Essa forma se apresenta como ordem de uma mesma realidade contínua, presente tanto numa dimensão predominante espacial e corporal da experiência, envolvendo objetos físicos, no tempo imediato; quanto numa dimensão predominantemente temporal, onde se situa um espaço relacional no qual segue se definindo quem está melhor ou pior e, ao final, o vencedor e o perdedor da partida. Nesse mundo dos jogos agonísticos, ambas as dimensões se mantêm articuladas por mecanismos de definição, acumulação e objetivação numérica dos eventos (como o placar) que são programados para funcionar de acordo com um princípio integrador de justiça, baseados em critérios de excelência e competitividade ? mecanismos cujas operações bem inter-relacionadas devem definir o melhor a cada partida, conferindo à realidade vivenciável nesse mundo um sentido de unidade e completude próprias de uma experiência singular.

Distribution, movements, and habitat use of small striped bass (Morone saxatilis) across multiple spatial scales

Distribution, movements, and habitat use of small (<46 cm, juveniles and individuals of unknown maturity) striped bass (Morone saxatilis) were investigated with multiple techniques and at multiple spatial scales (surveys and tag-recapture in the estuary and ocean, and telemetry in the estuary) over multiple years to determine the frequency and duration of use of non-natal estuaries. These unique comparisons suggest, at least in New Jersey, that smaller individuals (<20 cm) may disperse from natal estuaries and arrive in non-natal estuaries early in life and take up residence for several years. During this period of estuarine residence, individuals spend all seasons primarily in the low salinity portions of the estuary. At larger sizes, they then leave these non-natal estuaries to begin coastal migrations with those individuals from nurseries in natal estuaries. These composite observations of frequency and duration of habitat use indicate that non-natal estuaries may provide important habitat for a portion of the striped bass population.

Spatial and temporal distribution of grouper larvae (Serranidae: Epinephelinae: Epinephelini) in the Gulf of Mexico and Straits of Florida

Little is known about the seasonality and distribution of grouper larvae (Serranidae: Epinephelini) in the Gulf of Mexico and Atlantic Ocean off the coast of the southeast United States. Grouper larvae were collected from a transect across the Straits of Florida in 2003 and 2004 and during the Southeast Area Monitoring and Assessment Program spring and fall surveys from 1982 through 2005. Analysis of these larval data provided information on location and timing of spawning, larval distribution patterns, and interannual occurrence for a group of species not easily studied as adults. Our analyses indicated that shelf-edge habitat is important for spawning of many species of grouper—some species for which data were not previously available. Spawning for some species may occur year-round, but two peak seasons are evident: late winter and late summer through early fall. Interannual variability in the use of three important subregions by species or groups of species was partially explained by environmental factors (surface temperature, surface salinity, and water depth). A shift in species dominance over the last three decades from spring-spawned species (most of the commercial species) to fall-spawned species also was documented. The results of these analyses expand our understanding of the basic distribution and spawning patterns of northwest Atlantic grouper species and indicate a need for further examination of the changing population structure of individual species and species dominance in the region.