3,349 research outputs found
Review of the spatial and temporal distribution by life stage for 19 North Sea fish species
Considering the increase in human activity in the North Sea, particularly cargo shipping and the rapidly expanding construction and operation of oil platforms and wind farms, as well as the continued use of the area for military purposes, fisheries and sand extraction, there is a growing concern about the potentially harmful impacts of such anthropogenic activities on marine life. Particular concerns have been raised about the effect of loud impulse sounds and high noise levels, which may affect marine animal life in different ways: habitat use, such as feeding and migration, and reproduction patterns may be disturbed. In the extreme case animals may suffer from sub-lethal or lethal physical damage such as hearing loss and disrupted swim ladders. Knowledge of the spatial distribution and seasonal patterns in the presence of different life stages of marine species is therefore critical for assessing to what extent the dispersion of marine life overlaps with the distribution of human activities and for estimating how potentially harmful impacts can be mitigated both spatially and temporally. The aim of this desk study is consequently to provide a concise overview of existing information on seasonal patterns in the dispersion of fish species in the North Sea, in particular by highlighting the knowledge gaps
The impact of intellectual disability and sport expertise on cognitive and executive functions.
Our aim was to identify the suitability of three assessment tools (i.e., Flanker test, Updating Word Span, and Color Trails Test) for future inclusion in the classification process of elite Paralympic athletes with intellectual disability and to assess the strength of the relation between Executive function (EF) and intelligence. Cognitive and EF assessments were performed on 59 participants, divided into four groups according to their cognitive level (with versus without intellectual disability) and sport expertise (athlete versus novice). Inhibition and working memory update skills were implicated in people with intellectual disability. For set-shifting, a more nuanced picture was observed. Strong associations between EF and intelligence was found in people with intellectual disability. Working memory updating and set-shifting are relevant EF skills to assess in the context of elite sport; however, culture-free alternatives for the Updating Word Span test are needed, and alternatives to the Color Trails Test, less reliant on literacy skills are required
Distribution and contamination status of heavy metals in estuarine sediments near Cua Ong Harbour, Ha Long Bay, Vietnam
The distribution, controlling geochemical factors and contamination status of heavy metals in estuarine sediments near Cua Ong Habor, Ha Long Bay (Vietnam) were investigated. 36 surface sediment samples were collected and analyzed for major elements (Al, Ca, Fe, K, Mg, S), heavy metals (As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn), organic matter, loss on ignition (LOI), grain size composition and pH. Spatial distribution patterns of heavy metals as well as their controlling factors were elucidated based on geochemical mapping and statistical methods such as the Pearson ProductMoment linear correlation and Factor Analysis. The results illustrated that the distribution patterns of As, Cd, Cr, Cu, Ni, Pb and Zn are mainly controlled by organic matter and clay minerals and determined by the distribution of the finegrained fraction (F < 63 µm) in the sediments. In contrast, Fe and Mn compounds seem to exert some control on the distribution of Co. Carbonates partly control the distribution of Mn, but are not important with respect to the other studied heavy metals. The contamination status by heavy metals was assessed based on comparison with Canadian, Wisconsin- United States and Flemish numerical Sediment Quality Guidelines, and calculation of Geo-accumulation Index (Igeo) and Enrichment Factor (EF). The results indicated that natural processes such as weathering and erosion of bedrock are the main supply sources of heavy metals in sediments near Cua Ong Harbor. Among the studied heavy metals, only As is of concern whereas Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn seem to reflect their background concentrations in sediments of Ha Long Bay
Evolutionary history and identification of conservation units in the giant otter, Pteronura brasiliensis.
The giant otter, Pteronura brasiliensis, occupies a range including the major drainage basins of South America, yet the degree of structure that exists within and among populations inhabiting these drainages is unknown. We sequenced portions of the mitochondrial DNA (mtDNA) cytochrome b (612 bp) and control region (383 bp) genes in order to determine patterns of genetic variation within the species. We found high levels of mtDNA haplotype diversity (h = 0.93 overall) and support for subdivision into four distinct groups of populations, representing important centers of genetic diversity and useful units for prioritizing conservation within the giant otter. We tested these results against the predictions of three hypotheses of Amazonian diversification (Pleistocene Refugia, Paleogeography, and Hydrogeology). While the phylogeographic pattern conformed to the predictions of the Refugia Hypothesis, molecular dating using a relaxed clock revealed the phylogroups diverged from one another between 1.69 and 0.84 Ma, ruling out the influence of Late Pleistocene glacial refugia. However, the role of Plio-Pleistocene climate change could not be rejected. While the molecular dating also makes the influence of geological arches according to the Paleogeography Hypothesis extremely unlikely, the recent Pliocene formation of the Fitzcarrald Arch and its effect of subsequently altering drainage pattern could not be rejected. The data presented here support the interactions of both climatic and hydrological changes resulting from geological activity in the Plio-Pleistocene, in shaping the phylogeographic structure of the giant otter
QSAR analysis of salicylamide isosteres with the use of quantum chemical molecular descriptors
Quantitative relationships between the molecular structure and the biological activity of 49 isosteric salicylamide derivatives as potential antituberculotics with a new mechanism of action against three Mycobacterial strains were investigated. The molecular structures were represented by quantum chemical B3LYP/6-31G* based molecular descriptors. A resulting set of 220 molecular descriptors, including especially electronic properties, was statistically analyzed using multiple linear regression, resulting in acceptable and robust QSAR models. The best QSAR model was found for Mycobacterium tuberculosis (r(2) = 0.92; q(2) = 0.89), and somewhat less good QSAR models were found for Mycobacterium avium (r(2) = 0.84; q(2) = 0.78) and Mycobacterium kansasii (r(2) = 0.80; q(2) = 0.56). All QSAR models were cross-validated using the leave-10-out procedure
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