52 resultados para WESTERN-CAPE
Resumo:
Exchange of immature loggerhead sea turtles (Caretta caretta) between the northern and southern regions of the western Mediterranean was investigated using data obtained from several Spanish tagging programmes. Tagged turtles ranged in straight carapace length from 23.0 to 74.0 cm. Thirty-six turtles were recaptured after an average interval of 390.5±462.6 days (SD). As the mean dispersal distance (MDD) of a turtle population that spreads over the western Mediterranean would stabilize after 117 days (CI 95%: 98 to 149), two analyses were conducted that included data from turtles recaptured after 98 and 149 days respectively. In both analyses, turtles were recaptured more often than expected in the same region where they had been tagged. No difference was found in either of the two regions between the average distance between the capture and recapture locations and the expected MDD if the turtles were to remain in the region where they were first captured. Turtles recaptured after 15 and 25 days respectively were excluded from the analysis to ensure data independence. The overall evidence indicates that immature turtles exhibit strong site fidelity to certain areas and that there is a strong barrier to dispersal between the northern and southern parts of the western Mediterranean. Therefore, loggerhead turtles in the western Mediterranean should be split into at least two management units.
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Ecosystems are complex systems and changing one of their components can alter their whole functioning. Decomposition and biodiversity are two factors that play a role in this stability, and it is vital to study how these two factors are interrelated and how other factors, whether of human origin or not, can affect them. This study has tested different hypotheses regarding the effects of pesticides and invasive species on the biodiversity of the soil fauna and litter decomposition rate. Decomposition was measured using the litterbags technique. Our results indicate that pesticides had a negative effect on decomposition whereas invasive species increased decomposition rate. At the same time, the diversity of the soil biota was unaffected by either factor. These results allow us to better understand the response of important ecosystem functions to human‐induced alterations, in order to mitigate harmful effects or restore them wherever necessary.
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In recent years, a number of zoonotic flaviviruses have emerged worldwide, and wild birds serve as their major reservoirs. Epidemiological surveys of bird populations at various geographical scales can clarify key aspects of the eco-epidemiology of these viruses. In this study, we aimed at exploring the presence of flaviviruses in the western Mediterranean by sampling breeding populations of the yellow-legged gull (Larus michahellis), a widely distributed, anthropophilic, and abundant seabird species. For 3 years, we sampled eggs from 19 breeding colonies in Spain, France, Algeria, and Tunisia. First, ELISAs were used to determine if the eggs contained antibodies against flaviviruses. Second, neutralization assays were used to identify the specific flaviviruses present. Finally, for colonies in which ELISA-positive eggs had been found, chick serum samples and potential vectors, culicid mosquitoes and soft ticks (Ornithodoros maritimus), were collected and analyzed using serology and PCR, respectively. The prevalence of flavivirus-specific antibodies in eggs was highly spatially heterogeneous. In northeastern Spain, on the Medes Islands and in the nearby village of L'Escala, 56% of eggs had antibodies against the flavivirus envelope protein, but were negative for neutralizing antibodies against three common flaviviruses: West Nile, Usutu, and tick-borne encephalitis viruses. Furthermore, little evidence of past flavivirus exposure was obtained for the other colonies. A subset of the Ornithodoros ticks from Medes screened for flaviviral RNA tested positive for a virus whose NS5 gene was 95% similar to that of Meaban virus, a flavivirus previously isolated from ticks of Larus argentatus in western France. All ELISA-positive samples subsequently tested positive for Meaban virus neutralizing antibodies. This study shows that gulls in the western Mediterranean Basin are exposed to a tick-borne Meaban-like virus, which underscores the need of exploring the spatial and temporal distribution of this flavivirus as well as its potential pathogenicity for animals and humans.
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This paper is a preliminary report on the petrographic and geochemical characteristics of a new sulphate mineral associated with lacustrine glauberite layers. This mineral is present in two boreholes recently drilled in the Emet borate district (Mio-cene; western Anatolia , Turkey). The evaporitic succession in these boreholes is mainly formed of a glauber ite-probertiteal-ternation. We suggest the name"emetite", after the town of Emet, for the new sulphate mineral, although the fine crystal size hinders the appropriate chemical and crystallographic characterization required to propose it as a new mineral to the International Mineralogical Association. .
Resumo:
This paper is a preliminary report on the petrographic and geochemical characteristics of a new sulphate mineral associated with lacustrine glauberite layers. This mineral is present in two boreholes recently drilled in the Emet borate district (Mio-cene; western Anatolia , Turkey). The evaporitic succession in these boreholes is mainly formed of a glauber ite-probertiteal-ternation. We suggest the name"emetite", after the town of Emet, for the new sulphate mineral, although the fine crystal size hinders the appropriate chemical and crystallographic characterization required to propose it as a new mineral to the International Mineralogical Association. .
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Study on the composition and distribution of Phytobenthic Assemblages of Addaia Bay (Menorca, Western Mediterranean)
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Al Cap de Shirr e ff (Fig. 1) hi aflora una successió volcànica de com a mínim 450 m de potència, constituïda principalment per laves i, en menor proporció, bretxes vulcanoclàstiques (Fig. 2). Les laves són basalts olivínics subalcalins i andesites basàltiques, que generalment tenen un aspecte massiu. Tot i això, la successió volcànica localment forma una alternança decimètrica de nivells durs i tous, amb potències va r i a bles i presència local de discordances angulars i onlaps, que reflecteixen geometries deposicionals complexes. A la zona nord del Cap de Shirr e ff hi ha aflorament de bretxes vulcanoclàstiques d"aspecte massiu, que localment tenen intercalacions de laves...
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A charophyte succession has been established in nineteen sections and eight isolated outcrops from the Ebro Basin, ranging from the Priabonian ro the Aquitanian. Most assemblages were recovered fmm continuous sections and their abundance and diversity allow to define a new zonal scheme for the Upper Eocene-Lower Miocene of Europe. The new zonation includes nine subdivisions, based on the distribution of thirty-two species and directly correlated with the mammal standard levels. Changes in diversity, occurring mainly in the Middle and Upper Oligocene, have been related to climatíc variations. A new species, Chara sp. A. is also described and figured.
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The bryozoan fauna growing on deep-water corals (Lophelia, Madrepora) from the upper-slope of Catalonia (Blanes and Banyuls-sur-mer: NW Mediterranean Sea) was studied. Among the 36 species recorded, a new species, Escharella acuta sp. nov., and a new subspecies, Escharina dutertrei protecta ssp. nov., are described; five other species have been rarely reported or were unknown from the Mediterranean Sea (Copidozoum exiguum, Amphiblestrum flemingii, Schizomavella neptuni, Smittina crystallina, Phylactellipora eximia) . This epibiotic bryozoan fauna differs clearly from shallow-water assemblages and comprises a greater proportion of boreo-atlantic species.
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Ophichthus Rufus is a Mediterranean benthic fish with nocturnal habits. It lives in sand or mud bottoms at depths between 50 and 150m. Until now, nothing about its feeding habits was known. Stomach contents of 689 individuals, collected between 1985 and 1987, were analysed. The diet is basically composed of benthic organisms, among which the decapods processa canaliculata and Alpheus glaber and the teleost fish Callionymus maculatus are prominent. Young of both sexes and adult males have a euryphagic carnivorous diet, whereas adult females are closer to a stenophagic piscivorous diet
Resumo:
La inversió estrangera directa és important a causa dels seus avantatges per al país d'acollida, per exemple augmentarà la competitivitat i s’intensifica el desenvolupament. Els avantatges són significatives als països dels Balcans occidentals que s'enfronten a les dificultats de la competència i el creixement més baix de la UE-27. El treball analitza el tipus dominant de la IED de la UE-27 a la regió dels Balcans Occidentals a escala nacional i sectorial per formar les implicacions sobre el futur creixement de la competitivitat i la intensitat del desenvolupament econòmic. Es troba que la IED horitzontal domina als Balcans occidentals, per tant, el creixement de la competitivitat i el desenvolupament econòmic es va intensificar a la regió.
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This dissertation argues that the Government of the People’s Republic of China, when it made the decision to import a quota of Hollywood films in 1994 to revive the failing domestic film industry, had different possible criteria in mind. This project has studied four of them: first, importing films that gave a negative image of the United States; second, importing films that featured Chinese talent or themes; third, importing films that were box office hits in the United States; and fourth, importing films with a strong technological innovation ingredient. In order to find out the most important criteria for the Chinese Government, this dissertation offers a dataset that analyzes a population of 262 Hollywood films released in the PRC between 1994 and 2010. For each unit, a method has been developed to compile data that will determine whether the film reflects any of the four criteria, and findings in the form of yearly percentages have been drawn. Results show that, out of the four studied criteria, the two predominant reasons for China to import films were technological innovation and box office hits. This tells us that, at this point, the Chinese Government shows more interest in obtaining big revenues and learning from technically innovative American films than in delivering underlying political messages. This dissertation contributes to the existing literature by analyzing the content of all the films imported by China between 1994 and 2010, while integrating in the analysis variables based on the existing knowledge.
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The aim of this study is to provide an effective and quick reference guide based on the most useful European formulae recently published for subadult age estimation. All of these formulae derive from studies on postnatal growth of the scapula, innominate, femur, and tibia, based on modern skeletal data (173 ♂, 173 ♀) from five documented collections from Spain, Portugal, and Britain. The formulae were calculated from Inverse Regression. For this reason, these formulae are especially useful for modern samples from Western Europe and in particular on 20th century human remains from the Iberian Peninsula. Eleven formulae were selected as the most useful because they can be applied to individuals from within a wide age range and in individuals of unknown sex. Due to their high reliability and because they derive from documented European skeletal samples, we recommend these formulae be used on individuals of Caucasoid ancestry from Western Europe.
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Międzyrzecz Fortified Front, were Natura 2000 site PLH080003 Nietoperek is situated, was built by the Germans in the 1930s and during the World War II. It is composed of above ground bunkers connected by underground tunnels of ca. 32 km total length. Nietoperek is the eighth largest bats hibernation site in EU. Monthly censuses were carried out from October to April during three consecutive winter seasons (2011/12 – 2013/14) in area covering ca. 30% of the undergrounds. The aims of the study were: (1) to describe changes in numbers of each species in the course of hibernation season, (2) to suggest deadlines for counting particular bat species to obtain maximal numbers and (3) to describe negative impact of tourism on hibernating bats. The results will be useful for restriction of winter tourism in Nietoperek. The total number of bats observed during the study was 37869 individuals of 9 species. Because of difficulties in distinguishing without handling M. mystacinus and M. brandtii were treated as one group. M. myotis constituted from 53% (first season) to 64% (last season) of all hibernating bats. The maximal numbers of individuals were observed in November (first two seasons) and in December (third season). M. daubentonii constituted from 27% (first season) to 21% (last season) and M. nattereri from 10% (first season) to 11% (second season) of all bats. During the three seasons the maximal numbers of M. daubentonii and M. nattereri were observed in November and December respectively. B. barbastellus and P. auritus constituted from 4% (first season) to 2% (last season) of the multi species colony. The maximal numbers of B. barbastellus were observed in January and P. auritus in January (first and second seasons) and in December (third season). Results indicated that the best period for counting maximal numbers of M. myotis and M. daubentonii is November, for M. nattereri is December and for B. barbastellus and P. auritus is January. The study undertaken in the part visited by tourists in winter (total length of 900 m) proved negative effect caused by human disturbance with 23% decline of total bat numbers.
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Longline fisheries, oil spills, and offshore wind farms are some of the major threats increasing seabird mortality at sea, but the impact of these threats on specific populations has been difficult to determine so far. We tested the use of molecular markers, morphometric measures, and stable isotope (δ15N and δ13C) and trace element concentrations in the first primary feather (grown at the end of the breeding period) to assign the geographic origin of Calonectris shearwaters. Overall, we sampled birds from three taxa: 13 Mediterranean Cory's Shearwater (Calonectris diomedea diomedea) breeding sites, 10 Atlantic Cory's Shearwater (Calonectris diomedea borealis) breeding sites, and one Cape Verde Shearwater (C. edwardsii) breeding site. Assignment rates were investigated at three spatial scales: breeding colony, breeding archipelago, and taxa levels. Genetic analyses based on the mitochondrial control region (198 birds from 21 breeding colonies) correctly assigned 100% of birds to the three main taxa but failed in detecting geographic structuring at lower scales. Discriminant analyses based on trace elements composition achieved the best rate of correct assignment to colony (77.5%). Body measurements or stable isotopes mainly succeeded in assigning individuals among taxa (87.9% and 89.9%, respectively) but failed at the colony level (27.1% and 38.0%, respectively). Combining all three approaches (morphometrics, isotopes, and trace elements on 186 birds from 15 breeding colonies) substantially improved correct classifications (86.0%, 90.7%, and 100% among colonies, archipelagos, and taxa, respectively). Validations using two independent data sets and jackknife cross-validation confirmed the robustness of the combined approach in the colony assignment (62.5%, 58.8%, and 69.8% for each validation test, respectively). A preliminary application of the discriminant model based on stable isotope δ15N and δ13C values and trace elements (219 birds from 17 breeding sites) showed that 41 Cory's Shearwaters caught by western Mediterranean long-liners came mainly from breeding colonies in Menorca (48.8%), Ibiza (14.6%), and Crete (31.7%). Our findings show that combining analyses of trace elements and stable isotopes on feathers can achieve high rates of correct geographic assignment of birds in the marine environment, opening new prospects for the study of seabird mortality at sea.