987 resultados para Bulkan Peninsula


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Glacial cirques reflect former regions of glacier initiation, and are therefore used as indicators of past climate. One specific way in which palaeoclimatic information is obtained from cirques is by analysing their elevations, on the assumption that cirque floor altitudes are a proxy for climatically controlled equilibrium-line altitudes (ELAs) during former periods of small scale (cirque-type) glaciation. However, specific controls on cirque altitudes are rarely assessed, and the validity of using cirque floor altitudes as a source of palaeoclimatic information remains open to question. In order to address this, here we analyse the distribution of 3520 ice-free cirques on the Kamchatka Peninsula (eastern Russia), and assess various controls on their floor altitudes. In addition, we analyse controls on the mid-altitudes of 503 modern glaciers, currently identifiable on the peninsula, and make comparisons with the cirque altitude data. The main study findings are that cirque floor altitudes increase steeply inland from the Pacific, suggesting that moisture availability (i.e., proximity to the coastline) played a key role in regulating the altitudes at which former (cirque-forming) glaciers were able to initiate. Other factors, such as latitude, aspect, topography, geology and neo-tectonics seem to have played a limited (but not insignificant) role in regulating cirque floor altitudes, though south-facing cirques are typically higher than their north-facing equivalents, potentially reflecting the impact of prevailing wind directions (from the SSE) and/or variations in solar radiation on the altitudes at which former glaciers were able to initiate. Trends in glacier and cirque altitudes across the peninsula are typically comparable (i.e., values typically rise from both the north and south, inland from the Pacific coastline, and where glaciers/cirques are south-facing), yet the relationship with latitude is stronger for modern glaciers, and the relationship with distance to the coastline (and to a lesser degree with aspect) is notably weaker. These differences suggest that former glacier initiation (leading to cirque formation) was largely regulated by moisture availability (during winter months) and the control this exerted on accumulation; whilst the survival of modern glaciers is also strongly regulated by the variety of climatic and non climatic factors that control ablation. As a result, relationships between modern glacier mid-altitudes and peninsula-wide climatic trends are more difficult to identify than when cirque floor altitudes are considered (i.e., cirque-forming glaciers were likely in climatic equilibrium, whereas modern glaciers may not be).

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A sediment record from a small lake in the north-eastern part of the Kamchatka Peninsula has been investigated in a multi-proxy study to gain knowledge of Holocene climatic and environmental change. Pollen, diatoms, chironomids and selected geochemical parameters were analysed and the sediment record was dated with radiocarbon. The study shows Holocene changes in the terrestrial vegetation as well as responses of the lake ecosystem to catchment maturity and multiple stressors, such as climate change and volcanic eruptions. Climate change is the major driving force resulting in the recorded environmental changes in the lake, although recurrent tephra deposition events also contributed. The sediment record has an age at the base of about 10,000 cal yrs BP, and during the first 400 years the climate was cold and the lake exhibited extensive ice-cover during winter and relatively low primary production. Soils in the catchment were poor with shrub alder and birches dominating the vegetation surrounding the lake. At about 9600–8900 cal yrs BP the climate was cold and moist, and strong seasonal wind stress resulted in reduced ice-cover and increased primary production. After ca. 8900 cal yrs BP the forest density increased around the lake, runoff decreased in a generally drier climate resulting in decreased primary production in the lake until ca. 7000 cal yrs BP. This generally dry climate was interrupted by a brief climatic perturbation, possibly attributed to the 8.2 ka event, indicating increasingly windy conditions with thick snow cover, reduced ice-cover and slightly elevated primary production in the lake. The diatom record shows maximum thermal stratification at ca. 6300–5800 cal yrs BP and indicates together with the geochemical proxies a dry and slightly warmer climate resulting in a high productive lake. The most remarkably change in the catchment vegetation occurred at ca. 4200 cal yrs BP in the form of a conspicuous increase in Siberian dwarf pine (Pinus pumila), indicating a shift to a cooler climate with a thicker and more long-lasting snow cover. This vegetational change was accompanied by marked shifts in the diatom and chironomid stratigraphies, which are also indicative of colder climate and more extensive ice-cover.

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The Jutland peninsula in northern Denmark is home to the Limfjord, one of the largest estuarine bodies of water in the region. Human inhabitance of the Limfjord’s surrounding coastlines stretches back further than 7,800 cal BP, with anthropogenic influence on the landscape beginning approximately 6,000 cal BP. Understanding how the Limfjord as a system has changed throughout time is useful in comprehending subsistence patterns and anthropogenic influence. This research is part of a larger project aimed at discerning subsistence patterns and environmental change in the region. Following the Younger Dryas, as the Fennoscandian ice sheet began to melt, Denmark experienced isostatic rebound, which contributed to the complex sea level history in the region. Between ice melt and isostatic rebound, the Jutland peninsula experienced many transgression and regression events. Connections to surrounding seas have shifted throughout time, with most attention focused on the western connection of the Limfjord with the North Sea, which has experienced numerous closures and subsequent re-openings throughout the Holocene. Furthermore, the Limfjord-North Sea connection has been the focal point of research because of the west to east water flow in the system, and the present day higher salinity in the west compared to the east. Little to no consideration has been paid to the influence of the Kattegat and Baltic on the Limfjord until now. A 10m sediment core was taken from Sebbersund (near Nibe, Limfjord), along the connection between the Limfjord and the Kattegat in the east to understand how the eastern part of the system has changed and differed from changes observed in the west. The Sebbersund sequence spans a majority of the Holocene, from 9600 cal BP to 1030 cal BP, determined via radiocarbon dating of terrestrial macrofossils and bulk sediment. Over this time period palaeoenvironmental conditions were reconstructed through the use of geochemical analyses (13C, 15N, C:N), physical sediment analyses, dinoflagellate cyst abundances and molluscan analyses. apart from two instances of low salinity, one at the top and one at the bottom of the core, the sequence has a strong marine signal for a majority of the Holocene. Radiocarbon dating of bulk sediment samples showed the presence of old carbon in the system, creating an age offset between 1,300 ± 200 and 2,800 ± 200 calibrated 14C years compared to the age-depth curve based on the terrestrial macrofossils. This finding, along with the strong marine influence in the system, discerned through geochemical data, dinoflagellate cyst and mollusc counts, is important for obtaining accurate radiocarbon ages in the region and stresses the importance of understanding both the marine and freshwater reservoir effects. The marine dominance in the eastern Limfjord differs from the west, which is characterized by a number of freshwater events when the North Sea connection was closed off during the Holocene. The eastern connection was open to the Kattegat throughout a large portion of the Holocene, with influx of open ocean water entering the system during periods of higher sea level.

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In Britain, the majority of Lower and Middle Paleolithic archaeological finds come from river terrace deposits. The impressive “staircase” terrace sequences of southeast England, and research facilitated by aggregate extraction have provided a considerable body of knowledge about the terrace chronology and associated archaeology in that area. Such research has been essential in considering rates of uplift, climatic cycles, archaeological chronologies, and the landscapes in which hominins lived. It has also promoted the view that southeast England was a major hominin route into Britain. By contrast, the terrace deposits of the southwest have been little studied. The Palaeolithic Rivers of South West Britain (PRoSWEB) project employed a range of geoarchaeological methodologies to address similar questions at different scales, focusing on the rivers Exe, Axe, Otter, and the paleo-Doniford, all of which were located south of the maximum Pleistocene glacial limit (marine oxygen isotope stage [MIS] 4–2). Preliminary analysis of the fieldwork results suggests that although the evolution of these catchments is complex, most conform to a standard staircase-type model, with the exception of the Axe, and, to a lesser extent, the paleo-Doniford, which are anomalous. Although the terrace deposits are less extensive than in southeast Britain, differentiation between terraces does exist, and new dates show that some of these terraces are of great antiquity (MIS 10+). The project also reexamined the distribution of artifacts in the region and confirms the distributional bias to the river valleys, and particularly the rivers draining southward to the paleo–Channel River system. This distribution is consistent with a model of periodic occupation of the British peninsula along and up the major river valleys from the paleo–Channel River corridor. These data have a direct impact on our understanding of the paleolandscapes of the southwest region, and therefore our interpretations of the Paleolithic occupation of the edge of the continental landmass.

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Leticia Valle, the eleven-year-old narrator and protagonist of Rosa Chacel’s 1945 novel Memorias de Leticia Valle seduces and destroys her history teacher, Daniel. Here, I argue that Daniel represents traditionalist, right-wing interpretations of Spanish history while also recalling the importance of the colonial wars in Morocco in the build up to the Civil War, and the Nationalists’ use of Moroccan conscripts and recruits within the peninsula. Written at a time when history was being used to justify an armed rebellion, a civil war, and the imposition of a brutal dictatorship, Chacel’s novel depends on ellipses and absence to question historiographical principles. Furthermore, it combines continued reference to Spanish history with the use of violent and militant language. The most devastating conflict of all is between Leticia and Daniel: she silences and dehumanizes him, though she is not able to fully explain what happened. Writing from Switzerland, Chacel’s narrator takes possession of Spanish history at a time when dissent within Spain was being silenced by the Francoist regime.

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We describe seven polymorphic, dinucleotide microsatellite loci isolated from bank voles (Clethrionomys glareolus, Rodentia: Muridae) collected from the Wirral Peninsula, United Kingdom. Microsatellites were isolated as part of a long-term study on the wider effects of host-pathogen interactions of an endemic viral disease. These microsatellites showed between five and 13 alleles per locus in these populations. Observed and expected heterozygosities varied between 0.275 to 0.777 and 0.487 to 0.794, respectively. These markers will allow us to investigate the structure of this bank vole population. © 2005 Blackwell Publishing Ltd.

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Neuropeptide Y (NPY) is a 36 amino acid peptide that is abundantly expressed in both the central and peripheral nervous systems. NPY has previously been shown to be present in human dental pulp although its exact role in pulpal health and disease remains to be fully elucidated. In addition to serving a neurotransmitter role, NPY may also have a role in modulating the pulpal response to injury and inflammation. Indeed NPY is known to be a potent vasoconstrictor in a range of tissues. Recent work by our research group has demonstrated changes in sensory neuropeptide levels measured by radioimmunoassay (RIA) in healthy and carious teeth. In addition to elevated levels of sensory neuropeptides, it is also possible that the carious process is associated with increased levels of autonomic neuropeptides such as NPY. Objectives: The aim of the present study was to undertake a comprehensive quantitative RIA analysis of NPY expression in human dental pulps from carious and non-carious teeth. Methods: A total of 22 non-carious and 46 carious teeth were included in the study. NPY was measured in all samples using RIA. Briefly, the RIA system consisted of a total volume of 400 ul, comprising 100 ul anti-NPY antibody (Peninsula Laboratories), 200 ul human NPY synthetic standard or pulp sample, and 100 ul of 125I-labelled NPY as radioactive tracer. Results: The mean concentration of NPY in non-carious teeth was found to be 4.28 ng/g (4.34 SD) compared to 9.57 ng/g (9.39 SD) in carious teeth. Using ANOVA the difference in NPY levels between the non-carious group and the carious group was found to be statistically significant (p= 0.003). Conclusion: The significant increase in the levels of NPY in carious dental pulps reported in this study provides evidence for a role for NPY in the pulpal response to caries.

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This paper addresses the representation of landscape complexity in stated preferences research. It integrates landscape ecology and landscape economics and conducts the landscape analysis in a three-dimensional space to provide ecologically meaningful quantitative landscape indicators that are used as variables for the monetary valuation of landscape in a stated preferences study. Expected heterogeneity in taste intensity across respondents is addressed with a mixed logit model in Willingness to Pay space. Our methodology is applied to value, in monetary terms, the landscape of the Sorrento Peninsula in Italy, an area that has faced increasing pressure from urbanization affecting its traditional horticultural, herbaceous, and arboreal structure, with loss of biodiversity, and an increasing risk of landslides. We find that residents of the Sorrento Peninsula would prefer landscapes characterized by large open views and natural features. Residents also appear to dislike heterogeneous landscapes and the presence of lemon orchards and farmers' stewardship, which are associated with the current failure of protecting the traditional landscape. The outcomes suggest that the use of landscape ecology metrics in a stated preferences model may be an effective way to move forward integrated methodologies to better understand and represent landscape and its complexity.

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Lavandula spp. belong to the family Lamiatae and some species are often used in popular medicine and have been used for centuries in a large number of medical applications and in aromatherapy. Although similar ethnobotanical properties of Lavandula spp., its essential oils, general chemical composition and therapeutic applications differ from different species. Lavandula stoechas L. subsps. luisieri (Rozeira) Rozeira and L. viridis L’Hér are endemic to the Iberian Peninsula, widespread in the South of Portugal, namely in Southern Alentejo and Algarve. The aim of our study was evaluate the chemical composition and toxicological and pharmacological activities of leaves essential oils of spontaneous plants of L. stoechas L. subsps. luisieri (Alentejo) and L. viridis (Algarve). The essential oils of these wild plants, collected in spring, were obtained by hydrodistillation in a Clevenger-type apparatus and its chemical composition was evaluated by GC/FID. The acute toxicity of essential oils was evaluated "in vitro" using brine shrimp (LC50) and "in vivo" using Swiss mice (DL50). The analgesic and anti-inflammatory pharmacological properties of L. stoechas subsp. luisieri essential oil were evaluated in mouse or rats by the Amour-Smith and carrageen-induced paw edema tests, respectively. Results showed important differences in chemical composition of essential oils from two species analyzed either to diversity and proportion of its constituents. The essentials oils showed citotoxicity against Artemia salina and a DL50 higher than 2000 mg/kg for mice. The analgesic and anti-inflammatory activities of essential oils were exhibit for the doses of 100 and 200 mg/kg.

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Lavenders belong to the family Labiatae and represent some of the most popular medicinal plants of great economic importance. Their essential oils are important for the perfume, cosmetic, flavouring and pharmaceutical industries. However, despite its popularity, and the long tradition of use, biological properties of the various Lavandula species are not yet been well sustained by scientific or clinical studies and some available data being inconclusive and controversial [1]. Although Lavandula spp. have similar ethnobotanical properties, however, chemical composition and therapeutic uses differ from different species and main composition of essential oils showed differences with species and with the region were they grow [1,2,3]. L. stoechas L. subsps. luisieri (Rozeira) Rozeira. L. pedunculata (Mill.) Cav. and L. viridis L’Hér are endemic to the Iberian Peninsula, widespread in the South of Portugal, namely in Alentejo and Algarve. In our work, essential oils from the stems or leaves from wild grown plants of L. luisieri (Alentejo), L. pedunculata (Alentejo) and L. viridis (Algarve), were extracted by hydrodistillation and analyzed by GC-FID. Antimicrobial activity was evaluated by solid diffusion disk assay and minimal inhibitory concentration (MIC) against pathogenic Gram-positive and Gram-negative bacteria and food spoilage fungi.

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Background: Native pig breeds in the Iberian Peninsula are broadly classified as belonging to either the Celtic or the Mediterranean breed groups, but there are other local populations that do not fit into any of these groups. Most of the native pig breeds in Iberia are in danger of extinction, and the assessment of their genetic diversity and population structure, relationships and possible admixture between breeds, and the appraisal of conservation alternatives are crucial to adopt appropriate management strategies. Methods: A panel of 24 microsatellite markers was used to genotype 844 animals representing the 17 most important native swine breeds and wild populations existing in Portugal and Spain and various statistical tools were applied to analyze the results. Results: Genetic diversity was high in the breeds studied, with an overall mean of 13.6 alleles per locus and an average expected heterozygosity of 0.80. Signs of genetic bottlenecks were observed in breeds with a small census size, and population substructure was present in some of the breeds with larger census sizes. Variability among breeds accounted for about 20% of the total genetic diversity, and was explained mostly by differences among the Celtic, Mediterranean and Basque breed groups, rather than by differences between domestic and wild pigs. Breeds clustered closely according to group, and proximity was detected between wild pigs and the Mediterranean cluster of breeds. Most breeds had their own structure and identity, with very little evidence of admixture, except for the Retinto and Entrepelado varieties of the Mediterranean group, which are very similar. Genetic influence of the identified breed clusters extends beyond the specific geographical areas across borders throughout the Iberian Peninsula, with a very sharp transition from one breed group to another. Analysis of conservation priorities confirms that the ranking of a breed for conservation depends on the emphasis placed on its contribution to the betweenand within-breed components of genetic diversity. Conclusions: Native pig breeds in Iberia reveal high levels of genetic diversity, a solid breed structure and a clear organization in well-defined clusters.