Population structure in high shore littorinids: contrast between riprap and rocky shores

World Congress of Malacology, Ponta Delgada, July 22-28, 2013.The number of anthropogenic structures deployed in coastal areas has increased markedly in recent times and many studies have now shown that these structures seldom mimic the natural habitais they replace. To date, however, most such studies have focused on the numbers and relative abundance of species and little is known about how these structures affect the patterns of species aggregation and size structure, despite the fact that variations in these parameters may have important ecological consequences at population and community levels. Here we compare the relative abundance, patterns of aggregation and size structure of two high shore gastropod littorinids (Tectarius striatus and Melarhaphe neritoides) on riprap and adjacent rocky shores. While the relative abundance of T. striatus was similar on riprap and natural rocky shores, M. neritoides was significantly more abundant on rocky shores. At small spatial scales (cm’s) both littorinids specics showed more aggregated distributions on riprap. At larger scales (cm’s), both littorinids were also more aggregated on riprap although this was only significant for T. striatus. Habitat type influenced the size structure whith both species attaining a significantly larger size on riprap. Here we add to the wider literature by showing that anthropogenic structures can affect intertidal assemblages in ways other than richness or the relative abundance of organisms alone. The here documented variation in patterns of aggregation and size structure between habitats likely influence the population dynamics of these species and may have wider community level consequences

Avaliação do stock de Abalones: uma pesca sustentável

Jornadas "Ciência nos Açores – que futuro? Tema Ciências Naturais e Ambiente", Ponta Delgada, 7-8 de Junho de 2013.A falta de informação anterior ao início de uma exploração de uma espécie alvo é ponto comum à maior parte das pescarias. A maioria dos estudos só é iniciada após indícios claros de efeitos de um excesso de pesca. No entanto, esta situação é indicadora de que a pesca já causou alterações drásticas na estrutura das populações alvo e que, consequentemente, já não existe um ponto de referência que informe a gestão e a recuperação dos mananciais. A exploração do abalone nos Açores é virtualmente inexistente, ao contrário de muitas outras regiões onde a sua captura tem levado à ruptura dos mananciais. A espécie existente nos Açores, Haliotis tuberculata, é um recurso com elevado interesse gastronómico e económico e existem indícios de que tem sido gradualmente introduzida na gastronomia regional. Nos Açores os mananciais de H. tuberculata podem, à partida, ser considerados virgens, mas não existe informação sobre a sua abundância, biologia e ecologia. Concomitantemente, não existe qualquer tipo de restrição ou legislação regional relativamente à exploração deste marisco. O presente projecto tem como objectivo avaliar o estado actual das populações de H. tuberculata providenciando um ponto de referência para estudos futuros e garantindo deste modo uma avaliação rigorosa dos impactos de uma potencial pescaria. Neste projecto examinam-se aspectos da biologia e da ecologia de H. tuberculata que providenciarão dados úteis para garantir uma exploração sustentável deste recurso. O presente estudo providenciará também recomendações para a gestão desta pescaria baseadas na revisão bibliográfica e na informação recolhida.ABSTRACT: A common drawback in predicting the consequences of harvest rates is that there is no a priori information regarding the status of exploited populations. Most studies are done only when there is a perceived impact upon the targeted populations. In most situations, this means that fishing has already caused dramatic reductions in populations sizes and changes in the population structure so that a reference state against which to compare and predict the resilience or recovery of target populations does not exist. In the Azores unlike there has been little impact on the stocks of the abalone Haliotis tuberculata. However, H. tuberculata is a valuable and highly regarded resource and there is now evidence that it is slowly being introduced into the regional gastronomy. Although Azorean abalone stocks may be considered relatively virgin, there is yet no information regarding the local abundance, biology or ecology of this species. Similarly, there is no regional legislation regarding the exploitation of this shellfish. The present project aims to provide a reference state to which future studies can be compared and thus accurately assess the impact of a potential fishery. This involves examining the biology and ecology of H. tuberculata, creating a dynamic population model that will inform the authorities and provide valuable information that fosters sustainable harvest rates. The present project will also provide recommendations for the future management of the fishery based on a literature review and the field information collected

Effects of coastal orientation and depth on the distribution of subtidal benthic assemblages

Copyright © 2013 Blackwell Verlag GmbH.A better understanding of biological systems can only be gained if we understand what processes are important and how they operate to determine the distribution of organisms. Coastal orientation and depth can influence environmental conditions, including the degree of water motion and availability of light, which in turn may influence the horizontal and vertical patterns of organism distribution. Here, we used a mixed-model design to examine the effects of coastal orientation and depth on the structure of benthic assemblages by comparing the abundance and distribution of macroalgae and invertebrates in shallow and deep waters on the opposing coasts of Sa˜o Miguel. Generally, coastal orientation had little influence on the distribution of most taxa. In contrast, significant differences were generally associated with depth, although patterns were spatially variable at the scale of locations. This study suggests that depth, and processes operating at the scale of location, but not at the scale of the coast, have an important influence on these assemblages, and that failure to recognise such a scale of variability may hamper our ability to better understand the processes that structure these communities

DRAFT: An On-line Concurrent Test for Partial and Dynamically Reconfigurable FPGAs

The use of partial and dynamically reconfigurable FPGAs in reconfigurable systems opens exciting possibilities, since they enable the concurrent reconfiguration of part of the system without interrupting its operation. Nevertheless, larger dies and the use of smaller submicron scales in the manufacturing of this new kind of FPGAs increase the probability of failures after many reconfiguration processes. New methods of test and fault tolerance are therefore required, capable of ensuring system reliability.This paper presents improvements to our RaT Freed Resources technique, a structural concurrent test approach able to detect and diagnose faults without disturbing system operation, throughout its lifetime

Frondose and turf-dominated marine habitats support distinct trophic pathways: evidence from ¹⁵N and ¹³C stable isotope analyses

Marine vegetation plays an important structuring role, delivering key functions and services to coastal systems the extent of which depends on the foundation species and their architecture. In increasingly urbanised coastlines, turf-forming macroalgae are replacing frondose morphotypes. Trophic relationships within these systems can be studied through stable isotope analysis of the different food web compartments. In the present study, we investigated trophic pathways in two distinct macroalgal assemblages: one dominated by small brown frondose algae, and one dominated by low-lying turf-forming species. ¹⁵N and ¹³C isotopic signatures were determined for selected macroalgae and sedentary animals from distinct trophic levels, collected from two habitats on São Miguel Island (Azores, Portugal). In frondose habitats macroalgae appeared to make up the primary carbon source for the entire food web, whilst in turf-dominated habitats there was a decouple between macroalgae and higher trophic levels. Because canopy replacement by algal turf may affect the structure of the littoral food webs, coastal biodiversity conservation strategies should give priority to natural areas rich in canopy-forming algae.This research was supported by the European Commission BEST Preparatory Action, under the project “ECOSUBVEG – Changes in submersed vegetation: assessing loss in ecosystems services from frondose to depauperate systems dominated by opportunistic vegetation”, ref. 07.032700/2012/635752/SUB/B2. The research was also partially supported by Portuguese National Funds, through FCT – Fundação para a Ciência e a Tecnologia, within the projects UID/BIA/00329/2013, 2015 - 2018, UID/BIA/00329/2019 and UID/BIA/00329/2020-2023. Logistic support was also provided by CIRN/UAc (Centre of natural Resources of University of the Azores) and by CVARG (Centro de Vulcanologia e Avaliação de Riscos Geológicos). GMM was supported by a post-doctoral grant awarded by FCT (SFRH/BDP/63040/2009 and SFRH/BDP/108114/2015).info:eu-repo/semantics/publishedVersio

Testando ...

Os dispositivos lógicos reconfiguráveis, nomeadamente as FPGAs (Field Programmable Gate Arrays), conheceram uma considerável expansão nos últimos anos. A utilização deste tipo de componentes permite uma poupança de espaço nas placas de circuito impresso e uma mais rápida transição do projecto para o mercado, com um nível inigualável de flexibilidade quando comparado com a tradicional lógica discreta com funcionalidade pré-definida. Estas vantagens foram reforçadas pelo recente aparecimento de FPGAs dinâmica e parcialmente reconfiguráveis (de que a família Virtex da Xilinx é um exemplo), as quais permitem a adaptação dinâmica das funções implementadas pelo hardware a uma aplicação ou a um sistema em particular, sem interromper o funcionamento de todo o sistema, isto é, a funcionalidade destes dispositivos pode ser modificada sem que tal implique a sua paragem ou a do sistema em que se encontram inseridos. Esta nova possibilidade levanta, no entanto, uma questão: como garantir que, independentemente da funcionalidade implementada após múltiplos processos de reconfiguração, o sistema continua a operar sem falhas? Este trabalho procura dar resposta a esta questão propondo um novo método de teste estrutural concorrente, baseado no princípio da replicação e libertação de recursos para serem testados.info:eu-repo/semantics/publishedVersio

Associations between movement behaviours and obesity markers among preschoolers compliant and non-compliant with sleep duration:A latent profile analysis

This study identifies physical activity (PA) and sedentary behaviour (SB) clusters in preschoolers compliant (C) or non-compliant (NC) with sleep recommendations; and associates these clusters with obesity markers. PA and SB were objectively assessed (Actigraph WGT3-X) in 272 preschoolers (4.4 ± 0.7 years old). Sleep duration was parent-reported, and preschoolers were classified as C (3–4 years old: 600–780 min/day; 5 years old: 540–660 min/day) or NC with sleep recommendations. Body mass index (BMI) and waist circumference (WC) were assessed according to international protocols. Moderate to vigorous physical activity (MVPA) and light physical activity (LPA) were categorized as low/high (60 min/day or <180 min/180 min/day, respectively). SB was defined according to mean values between clusters. Latent profile analysis was performed. Associations between the observed clusters and obesity markers were determined using linear regression (RStudio; 1.3.1073). Four cluster solutions for C and NC preschoolers were identified. A negative association between C/Low MVPA cluster and BMI, and a positive association between NC/Low MVPA and BMI (β = −0.8, 95%CI = −1.6;−0.1, and β = 0.9, 95%CI = 0.1;1.7, respectively) were observed. No association was seen for SB clusters. Adequate sleep duration may have a protective role for preschoolers’ BMI, even if the children do not comply with MVPA recommendations

Calibração do Modelo de Interação de Superfície Atmosfera (sib2) para uma Plantação de Arroz na Região Central do Rio Grande do Sul

Calibração do modelo de interação de superfície atmosfera(SiB2) para uma plantação de arroz na região central doRio Grande do Su

Pseudobatos horkelii, Brazilian Guitarfish

The Brazilian Guitarfish (Pseudobatos horkelii) is a small (to 138 cm total length) shark-like ray that occurs in the Southwest Atlantic from Rio de Janeiro, Brazil, to northern Argentina. It is demersal on soft substrates of the continental shelf inshore to 150 m depth. It is captured in intense and largely unmanaged commercial and artisanal demersal trawl, gillnet, longline, and beach seine fisheries throughout its geographic range. There are three estimates of population reduction. First, in Rio Grande do Sul, total landings increased from 842 t in 1975 to 1,804 t in 1984 and then declined continuously to 157 t in 2001, the equivalent of a >99% reduction over three generations (55.5 years). Second, the average research trawl catch-per-unit-effort of Brazilian Guitarfish in southern Brazil over the years 1993 to 1999 was 17% of that observed during 1975 to 1986, also the equivalent of a >99% reduction over three generations. Fisheries remain intense and unmanaged there. Third, in Uruguay, this guitarfish is captured frequently in gillnets and longlines, is landed, and is sometimes targeted, and it is also captured in artisanal trawl fisheries. Catches from research trawls there in the 1980s and early 1990s were on average around 1,400 kg/hr, and between 2013 and 2017 were only 480 kg/hr, the equivalent of a >92% reduction over three generations. In Argentina, it is suspected that intense and inadequately managed gillnet fishing pressure has led to declines in abundance there as well. Overall, due to intense and inadequately managed fishing pressure throughout its range, and steep population declines, it is inferred that the Brazilian Guitarfish has undergone a population reduction of >80% over the past three generations (55.5 years), and it is assessed as Critically Endangered A2bd.Fil: Pollom, R.. University Fraser Simon; CanadáFil: Barreto, R.. Instituto Chico Mendes de Conservacao Da Biodiversidade; BrasilFil: Charvet, P.. Universidade Federal do Paraná; BrasilFil: Chiaramonte, Gustavo Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Estación Hidrobiológica de Puerto Quequén (sede Quequén); ArgentinaFil: Cuevas, J. M.. Wildlife Conservation Society; Estados UnidosFil: Herman, K.. Georgia Aquarium; Estados UnidosFil: Martins, M. F.. Universidade Federal Do Rio Grande.; BrasilFil: Montealegre Quijano, S.. Universidade Federal de Sao Paulo; BrasilFil: Motta, F.. Universidade Federal de Sao Paulo; BrasilFil: Paesch, L.. Dirección Nacional de Recursos Acuáticos; UruguayFil: Rincon, G.. Universidade Federal Do Maranhao.; Brasi

The first observed stellar occultations by the irregular satellite Phoebe (Saturn IX) and improved rotational period

peer reviewedWe report six stellar occultations by Phoebe (Saturn IX), an irregular satellite of Saturn, obtained between mid-2017 and mid-2019. The 2017 July 6 event was the first stellar occultation by an irregular satellite ever observed. The occultation chords were compared to a 3D shape model of the satellite obtained from Cassini observations. The rotation period available in the literature led to a sub-observer point at the moment of the observed occultations where the chords could not fit the 3D model. A procedure was developed to identify the correct sub-observer longitude. It allowed us to obtain the rotation period with improved precision compared to the currently known value from literature. We show that the difference between the observed and the predicted sub-observer longitude suggests two possible solutions for the rotation period. By comparing these values with recently observed rotational light curves and single- chord stellar occultations, we can identify the best solution for Phoebe's rotational period as 9.27365 ± 0.00002 h. From the stellar occultations, we also obtained six geocentric astrometric positions in the ICRS as realized by the Gaia DR2 with uncertainties at the 1-mas level