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151.
Loggerhead turtles nesting in the Mediterranean Sea exhibit remarkable genetic structuring. This paper tests the hypothesis that young loggerhead turtles from different rookeries do not distribute homogeneously among the major Mediterranean foraging grounds, due to a complex pattern of surface currents. We extracted long fragments of mitochondrial DNA from 275 stranded or bycaught juvenile turtles from six foraging grounds (Catalano-Balearic Sea, Algerian basin, Tyrrhenian Sea, Adriatic Sea, northern Ionian Sea and southern Levantine Sea). We used a Bayesian mixed-stock analysis to estimate the contributions from rookeries in the Mediterranean, the North-west Atlantic and Cape Verde to the studied foraging grounds. Differences were found in the relative contribution of juvenile turtles of Atlantic and Mediterranean origin to each foraging ground. A decreasing proportion of Atlantic juveniles was detected along the main surface current entering the Mediterranean, with a high prevalence of turtles from eastern Florida in the Algerian basin and lower numbers elsewhere. In regard to the turtles of Mediterranean origin, juveniles from Libya prevailed in central and western Mediterranean foraging grounds other than the Algerian basin. Conversely, the Adriatic Sea was characterised by a large presence of individuals from western Greece, while the southern Levantine Sea was inhabited by a heterogeneous mix of turtles from the eastern Mediterranean rookeries (Turkey, Lebanon and Israel). Overall, the distribution of juveniles may be related to surface circulation patterns in the Mediterranean and suggests that fisheries might have differential effects on each population depending on the overlap degree between foraging and fishing grounds.  相似文献   
152.
In this study, the striated heron (Butorides striatus), a species that reproduces in the Middle Paraná River floodplain, was examined for lead, cadmium, chromium, zinc, nickel, mercury and copper concentrations, using liver, kidney, muscle, vertebra and feathers. The results showed low exposure to chromium because all tissue samples had concentrations below the limit of detection. Similar results were obtained for nickel and lead, with the exception of vertebra. This might be associated with either long-term exposure to these metals, or it may be that both nesting and wintering areas are non-polluted. Zinc and copper, both essential metals, were found in all tissues and their concentrations were within the ranges reported in the literature. Mercury was also found in all tissues, but at very low concentrations and even at concentrations below those that produce negative effects in several species of birds (e.g. reproductive success, food intake). Studies of this type are needed to interpret the role of organisms within environments impacted by different human activities.  相似文献   
153.
New lines of evidence suggest that less than 10% of neurodegenerative diseases have a strict genetic aetiology and other factors may be prevalent. Environmental exposures to potentially toxic elements appear to be a risk factor for Parkinson’s, Alzheimer’s and sclerosis diseases. This study proposes a multidisciplinary approach combining neurosciences, psychology and environmental sciences while integrating socio-economic, neuropsychological, environmental and health data. We present the preliminary results of a neuropsychological assessment carried out in elderly residents of the industrial city of Estarreja. A battery of cognitive tests and a personal questionnaire were administered to the participants. Multivariate analysis and multiple linear regression analysis were used to identify potential relationships between the cognitive status of the participants and environmental exposure to potentially toxic elements. The results suggest a relationship between urinary PTEs levels and the incidence of cognitive disorders. They also point towards water consumption habits and profession as relevant factors of exposure. Linear regression models show that aluminium (R 2 = 38%), cadmium (R 2 = 11%) and zinc (R 2 = 6%) are good predictors of the scores of the Mini-Mental State Examination cognitive test. Median contents (µg/l) in groundwater are above admissible levels for drinking water for aluminium (371), iron (860), manganese (250), and zinc (305). While the World Health Organization does not provide health-based reference values for aluminium, results obtained from this study suggest that it may have an important role in the cognitive status of the elderly. Urine proved to be a suitable biomarker of exposure both to elements with low and high excretion rates.  相似文献   
154.
Behavioral Ecology and Sociobiology - Scents play an important role in the life of most terrestrial mammals and may transmit valuable information about conspecifics. Olfaction was long considered...  相似文献   
155.
Aerobic and anaerobic microbial key processes were quantified and compared to microbial numbers and morphological structure in Mediterranean sponges. Direct counts on histological sections stained with DAPI showed that sponges with high microbial abundances (HMA sponges) have a denser morphological structure with a reduced aquiferous system compared to low microbial abundance (LMA) sponges. In Dysidea avara, the LMA sponge, rates of nitrification and denitrification were higher than in the HMA sponge Chondrosia reniformis, while anaerobic ammonium oxidation and sulfate reduction were below detection in both species. This study shows that LMA sponges may host physiologically similar microbes with comparable or even higher metabolic rates than HMA sponges, and that anaerobic processes such as denitrification can be found both in HMA and LMA sponges. A higher concentration of microorganisms in the mesohyl of HMA compared to LMA sponges may indicate a stronger retention of and, hence, a possible benefit from associated microbes.  相似文献   
156.
Ladybirds (Coleoptera: Coccinellidae) provide services that are critical to food production, and they fulfill an ecological role as a food source for predators. The richness, abundance, and distribution of ladybirds, however, are compromised by many anthropogenic threats. Meanwhile, a lack of knowledge of the conservation status of most species and the factors driving their population dynamics hinders the development and implementation of conservation strategies for ladybirds. We conducted a review of the literature on the ecology, diversity, and conservation of ladybirds to identify their key ecological threats. Ladybird populations are most affected by climate factors, landscape composition, and biological invasions. We suggest mitigating actions for ladybird conservation and recovery. Short-term actions include citizen science programs and education, protective measures for habitat recovery and threatened species, prevention of the introduction of non-native species, and the maintenance and restoration of natural areas and landscape heterogeneity. Mid-term actions involve the analysis of data from monitoring programs and insect collections to disentangle the effect of different threats to ladybird populations, understand habitat use by taxa on which there is limited knowledge, and quantify temporal trends of abundance, diversity, and biomass along a management-intensity gradient. Long-term actions include the development of a worldwide monitoring program based on standardized sampling to fill data gaps, increase explanatory power, streamline analyses, and facilitate global collaborations.  相似文献   
157.
There is a strong political divide on climate change in the US general public, with Liberals and Democrats expressing greater belief in and concern about climate change than Conservatives and Republicans. Recent studies find a similar though less pronounced divide in other countries. Its leadership in international climate policy making warrants extending this line of research to the European Union (EU). The extent of a left–right ideological divide on climate change views is examined via Eurobarometer survey data on the publics of 25 EU countries before the 2008 global financial crisis, the 2009 ‘climategate’ controversy and COP-15 in Copenhagen, and an increase in organized climate change denial campaigns. Citizens on the left consistently reported stronger belief in climate change and support for action to mitigate it than did citizens on the right in 14 Western European countries. There was no such ideological divide in 11 former Communist countries, likely due to the low political salience of climate change and the differing meaning of left–right identification in these countries.  相似文献   
158.
At the nexus of watersheds, land, coastal areas, oceans, and human settlements, river delta regions pose specific challenges to environmental governance and sustainability. Using the Amazon Estuary-Delta region (AD) as our focus, we reflect on the challenges created by the high degree of functional interdependencies shaping social–ecological dynamics of delta regions. The article introduces the initial design of a conceptual framework to analyze delta regions as coupled social–ecological systems (SES). The first part of the framework is used to define a delta SES according to a problem and/or collective action dilemma. Five components can be used to define a delta SES: social–economic systems, governance systems, ecosystems-resource systems, topographic-hydrological systems, and oceanic-climate systems. These components are used in association with six types of telecoupling conditions: socio-demographic, economic, governance, ecological, material, and climatic-hydrological. The second part of the framework presents a strategy for the analysis of collective action problems in delta regions, from sub-delta/local to delta to basin levels. This framework is intended to support both case studies and comparative analysis. The article provides illustrative applications of the framework to the AD. First, we apply the framework to define and characterize the AD as coupled SES. We then utilize the framework to diagnose an example of collective action problem related to the impacts of urban growth, and urban and industrial pollution on small-scale fishing resources. We argue that the functional interdependencies characteristic of delta regions require new approaches to understand, diagnose, and evaluate the current and future impacts of social–ecological changes and potential solutions to the sustainability dilemmas of delta regions.  相似文献   
159.
Based on the national database of 28,104 water rights (concessions) granted in Colombia, this paper presents an analysis of how the principles of equity and sustainability are reflected in water allocation. Concessions appear to be an exclusionary mechanism since only a minority of small water users have concessions and the distribution of water volumes among those who have them is extremely inequitable. The 2009 Gini coefficient calculated for water concessions granted for agriculture was 0.90 compared with the rural land Gini of 0.88 (both indicators grouping holdings under the same entity). More than half of the Colombian departments have a higher Gini coefficient for water than for land, suggesting that water rights are at least as unequally distributed as land, in one of the most inequitable countries in Latin America. Water allocated to domestic, agriculture and hydropower use indicates a lack of consistency of water allocation criteria across regions. The volumetric and administrative attributes of water allocation in Colombia do not account for environmental flows or the concerns of marginalised groups of society that have limited access to the mechanism. Water allocation as a technical task, with limited transparency and secluded from public scrutiny, does not contribute to the solution of increasing water-related conflicts.  相似文献   
160.
Genotoxic damage was evaluated in 70 agricultural workers, 25 women and 45 men, exposed to pesticides in Las Grullas, Ahome, Sinaloa, Mexico, with an average of 7 years of exposure. The effect was detected through the sister chromatid exchanges (SCE) in lymphocytes of peripheral blood and micronuclei (MN) and other nuclear anomalies (NA) in buccal exfoliated cells. Also, the influence on cellular proliferation kinetics (CPK) was studied by means of the replication index (RI) and the cytotoxic effect was examined with the mitotic index (MI). The non-exposed group consisted of 70 other persons, 21 women and 47 men from the city of Los Mochis, Sinaloa, Mexico. Significant differences between the exposed and the non-exposed groups were observed in SCE, CPK, MI, MN and NA. Analysis of variance revealed that age, gender, smoking and alcohol consumption did not have a significant effect on genetic damage. However, there was a correlation between exposure time to pesticides and SCE frequency. These results could have been due to the exposure of workers to pesticides containing different chemical compounds. This study afforded valuable data to estimate the possible risk to health associated with pesticide exposure.  相似文献   
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