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191.
Rhizostoma pulmo is one of the most abundant scyphomedusae along the Mediterranean coasts. To understand changes in the population densities of the medusa stage and its relationship with the benthic stage, we describe all developmental stages from the life cycle of R. pulmo, from the scyphistoma stage to young medusae reared in the laboratory. Mature scyphistomae showed a mean total body length of 1.7 mm and the average tentacle number was 16. Asexual reproduction occurred by lateral budding, podocyst and pedalocyst production. Each strobila released up to 8 ephyrae that had a mean total body diameter of 3.5 mm. Moreover, we also present data on the temporal and spatial distribution of the species in the Catalan Sea and the coastal lagoon on Mar Menor (NW Mediterranean) during the years 2007–2009. In the Catalan Sea, the presence of adult R. pulmo was recorded as extended along the whole coast, but most of the observation was concentrated in the central area; the highest abundances were recorded during the months of July and August. The highest number of observations was detected in 2008 in coincidence with the inter-annual variation observed in the Mar Menor lagoon.  相似文献   
192.
Suspended solids either as total suspended solids (TSS) or suspended sediment concentration (SSC) is an integral particulate water quality parameter that is important in assessing particle-bound contaminants. At present, nearly all stormwater runoff quality monitoring is performed with automatic samplers in which the sampling intake is typically installed at the bottom of a storm sewer or channel. This method of sampling often results in a less accurate measurement of suspended sediment and associated pollutants due to the vertical variation in particle concentration caused by particle settling. In this study, the inaccuracies associated with sampling by conventional intakes for automatic samplers have been verified by testing with known suspended sediment concentrations and known particle sizes ranging from approximately 20 μm to 355 μm under various flow rates. Experimental results show that, for samples collected at a typical automatic sampler intake position, the ratio of sampled to feed suspended sediment concentration is up to 6600% without an intake strainer and up to 300% with a strainer. When the sampling intake is modified with multiple sampling tubes and fitted with a wing to provide lift (winged arm sampler intake), the accuracy of sampling improves substantially. With this modification, the differences between sampled and feed suspended sediment concentration were more consistent and the sampled to feed concentration ratio was accurate to within 10% for particle sizes up to 250 μm.  相似文献   
193.
The recent publication of evaluation protocols for vapor source term models and vapor dispersion models have influenced the modeling approaches that can be used for approval of new and expansion projects at LNG receiving terminals. In the past few years the scientific basis of integral vapor source term models has been questioned with growing concerns regarding their validity. In this paper, the shallow water equations (SWEs) were solved to study the characteristics of the evaporating LNG pool associated with a constant flow rate spill of LNG into a concrete sump. In the early stages of pool spreading, the leading edge thickness profile of the SWE model scales with the square root of the distance from the leading edge as the pool spreads. After the edge of the pool reaches the wall, the reflected wave forms a hydraulic jump that travels back towards the center of the pool at a speed that is considerably slower than the initial spreading of the pool. Once the hydraulic jump reaches the center, the pool assumes a nearly flat free surface for the rest of the spill. The pool spreading and the rate of evaporation from the SWEs were then compared to the solution provided by the integral model, PHAST. The two approaches were found to agree well with one another. The SWE model was also used to demonstrate the influence of an elevated spill source. With an elevated source, the LNG pool spreads faster, significantly increasing the initial rate of vaporization and peak vaporization rate. This increase in the initial rate of vaporization could lead to an increase in the vapor cloud hazard distance. The SWE model was also used to demonstrate the influence of an inclined sump floor in the shape of an inverted cone where the spilling LNG accumulates in the low vertex of the cone. Inclined sump floors can be used to significantly reduce the cumulative evaporation, making them attractive as a possible mitigation approach in cases where a containment sump is located close to a property boundary.  相似文献   
194.
This study tested the hypotheses that (1) exposure to treated Water Reclamation Plant (WRP) effluent will induce biological effects in exposed fish that are consistent with environmental estrogen (EE) exposure; and (2) seasonal differences in effluent composition will moderate biological effects. We conducted seven on‐site exposures using a mobile laboratory. Total estrogenicity of effluents was 10‐ to 20‐fold higher during spring than in fall. Common EEs including steroid estrogens, alkylphenols, and bisphenol‐A were ubiquitous. An unusual spike in total estrogenicity identified a combined sewer overflow event. Fathead minnows (Pimephales promelas) responded to exposure with subtle changes in vitellogenin concentrations and secondary sex characteristics. An opportunity to assess a common carp (Cyprinus carpio) population permanently sustained inside the Stickney WRP revealed pronounced exposure effects, but also the resilience of biological organisms even under long‐term exposure. In contrast to other studies, no histopathological changes were found. The mobile exposure laboratory proved capable of maintaining U.S. Environmental Protection Agency‐recommended exposure conditions while providing flexibility for rapid deployment at multiple sites with minimal operational disruption. Further studies using this platform hold promise to resolve the convoluted interactions between complex effluents and inherent biological complexity.  相似文献   
195.
ABSTRACT

This paper explores how Australia's Indigenous peoples understand and respond to climate change impacts on their traditional land and seas. Our results show that: (i) Indigenous peoples are observing modifications to their country due to climate change, and are doing so in both ancient and colonial time scales; (ii) the ways that climate change terminology is discursively understood and used is fundamental to achieving deep engagement and effective adaptive governance; (iii) Indigenous peoples in Australia exhibit a high level of agency via diverse approaches to climate adaptation; and (iv) humour is perceived as an important cultural component of engagement about climate change and adaptation. However, wider governance regimes consistently attempt to “upscale” Indigenous initiatives into their own culturally governed frameworks - or ignore them totally as they “don't fit” within neoliberal policy regimes. We argue that an opportunity exists to acknowledge the ways in which Indigenous peoples are agents of their own change, and to support the strategic localism of Indigenous adaptation approaches through tailored and place-based adaptation for traditional country.  相似文献   
196.
Climate change will impact on ecological, social, and economic elements of fisheries; however, the three are seldom considered in an integrated fashion. We develop a fishery-level assessment of economic resilience to climate change for the Tasmanian rock lobster fishery, a linked social–ecological system. We outline the main climate change forcing influences that link climate change to the fishery via changes in lobster abundance, distribution, and phenology. Using a bottom-up approach, we identify twelve economic attributes strongly related to the fisheries’ economic resilience to climate change. Resilience attributes are grouped according to the level of the economic domain (business, sectoral, and governance). Attributes are then evaluated to determine the overall economic resilience of the rock lobster fishery in the context of the specific nature of predicted climate change effects. We identify areas of low resilience in the economic sub-system for this fishery. Evaluating the economic resilience of regional fisheries using this integrated, interdisciplinary framework provides a practical, parsimonious, and conceptually sound basis for undertaking comprehensive and contextually tailored assessments of climate change impacts and economic vulnerability. The framework can be extended to include a broader range of climate change impacts and the social domain of the human sub-system.  相似文献   
197.
Climate change is affecting fishing communities across Bangladesh. While work has been undertaken to investigate the nature of these impacts, understanding how fishers perceive climate change at a local level, especially within developing countries, is crucial. This paper presents the results of a three-year study of the contextual determinants and dimensions of artisanal fishing community perceptions about climate change in coastal Bangladesh. Results of this study indicate that geographic characteristics, socio-economic status, worldviews, tradition, observations and disaster experiences are important determinants for shaping fishers’ perceptions about climate change. Fishers also demonstrate a long-standing tradition of risk adaptation strategies, but do not link them to climate change. We argue that these perceptions provide ideas for how to form appropriate climate responses at local levels not only in Bangladesh but other developing countries.  相似文献   
198.
The extent to which active female mating preferences influence male reproductive success in mammals is unclear, particularly for promiscuously breeding species like chimpanzees (Pan troglodytes). Previous studies from multiple long-term study sites have shown that female chimpanzees mate more restrictively around ovulation, and this has been taken as evidence for female choice. However, none of these studies rigorously evaluated the alternative hypothesis that restrictive mating results not from unconstrained choice, but in response to coercive mate guarding, in which males use punishment and intimidation to reduce female promiscuity and promote their own mating interests. Nor did they consider evidence for the potential genetic or phenotypic benefits that females might be choosing. Using 11 years of data from the Kanyawara community in Kibale National Park, Uganda, we previously demonstrated that males achieve elevated mating success with those females toward whom they direct high levels of aggression. Here we extend those findings to show that even female copulatory approaches, which have previously been attributed to female choice, are correlated with male aggression. Specifically, individual females at our site initiated periovulatory copulations most frequently with the males who were most aggressive toward them throughout their cycles. Those males showed high rates of aggression toward females throughout estrus, despite achieving high copulation rates, demonstrating a continuing conflict of interest over the exclusivity of mating access. Because sexual coercion is potentially widespread in primates and other mammals, our results stress the importance of considering the influence of male aggression in studies of female choice.  相似文献   
199.
Despite decades of messages warning about the dangers of tobacco use in pregnancy, 10% to 15% of pregnant women continue to smoke. Furthermore, an increased popularity of electronic nicotine delivery systems (ENDS) over the past decade in women of childbearing age raises parallel concerns regarding the effects of vaporized nicotine use in pregnancy. While research using animal models which mimic tobacco smoke and nicotine exposure in pregnancy have largely replicated findings in humans, few studies focus directly on the effects of these exposures on the placenta. Because the placenta is a fetal derived tissue, and nicotine and other components of tobacco smoke are either processed by or transported directly through the placenta, such studies help us understand the risks of these exposures on the developing fetus. In this review, we summarize research on the placenta and placental-derived cells examining either tobacco smoke or nicotine exposure, including both histologic and subcellular (ie, epigenetic and molecular) modifications. Collectively, these studies reveal that tobacco and nicotine exposure are accompanied by some common and several unique molecular and epigenomic placental modifications. Consideration of the nature and sequelae of these molecular mediators of risk may help to better inform the public and more effectively curtail modifiable behavior.  相似文献   
200.
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