845 resultados para sensory ecology


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A 57-year-old man, operated eight years before for a left frontal falx meningioma, presented with short lasting, stereotyped episodes of paresthesias ascending from the right foot to the hand. A diagnosis of somatosensory seizures with jacksonian march was made. The patient was given antiepilectics but 5 days later, a few hours after another paresthesic episodes, he developed right hemiplegia, hemianesthesia and dysartria due to an infarct of left capsular posterior limb. We deem that in this patient the paresthesic episodes were more likely an expression of a capsular warning syndrome than of parietal epilepsy because of the frontal localization of the surgical lesion, the absence of motor components in all episodes, the negativity of repeated EEG, and the lack of recurrences after stroke. In capsular warning syndrome sensory symptoms mimicking a jacksonian march can be due to ischemic depolarization progressively recruiting the somatotopically arranged sensory fibers in the posterior capsular limb.

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OBJECTIVE: To describe an alternative method for the treatment of non-responsive self-mutilation injuries in three dogs after carpal/tarsal arthrodesis. STUDY DESIGN: Case series ANIMALS: Two dogs with carpal injury and one dog with tarsal injury treated by arthrodesis METHODS: All dogs developed self-mutilation injuries due to licking and/or chewing of the toes within 21-52 days of surgery. Clinical signs did not resolve within one week after conservative treatment with wound debridement and protective bandages. Following general anaesthesia, a deep horseshoe-shaped skin incision, including the subdermal tissue, was performed proximal to the self-mutilation injury transecting the sensory cutaneous afferent nerves. The skin incision was closed with simple interrupted sutures. RESULTS: All wounds healed without complication. Self-mutilation resolved completely within 24 hours after surgery in all dogs. No recurrence was observed (5 months to 3 years). CONCLUSION: Non-selective cutaneous sensory neurectomy may lead to resolution of self-mutilation following arthrodesis in dogs. CLINICAL RELEVANCE: Failure of conservative treatment in self-mutilation injuries often leads to toe or limb amputation as a last resort. The technique described in this case series is a simple procedure that should be considered prior to amputation. The outcome of this procedure in dogs self-multilating due to neurological or behavioral disturbances unrelated to carpal or tarsal arthrodesis is not known.

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Understanding factors driving the ecology of N cycling microbial communities is of central importance for sustainable land use. In this study we report changes of abundance of denitrifiers, nitrifiers and nitrogen-fixing microorganisms (based on qPCR data for selected functional genes) in response to different land use intensity levels and the consequences for potential turnover rates. We investigated selected grassland sites being comparable with respect to soil type and climatic conditions, which have been continuously treated for many years as intensely used meadows (IM), intensely used mown pastures (IP) and extensively used pastures (EP), respectively. The obtained data were linked to above ground biodiversity pattern as well as water extractable fractions of nitrogen and carbon in soil. Shifts in land use intensity changed plant community composition from systems dominated by s-strategists in extensive managed grasslands to c-strategist dominated communities in intensive managed grasslands. Along the different types of land use intensity, the availability of inorganic nitrogen regulated the abundance of bacterial and archaeal ammonia oxidizers. In contrast, the amount of dissolved organic nitrogen determined the abundance of denitrifiers (nirS and nirK). The high abundance of nifH carrying bacteria at intensive managed sites gave evidence that the amounts of substrates as energy source outcompete the high availability of inorganic nitrogen in these sites. Overall, we revealed that abundance and function of microorganisms involved in key processes of inorganic N cycling (nitrification, denitrification and N fixation) might be independently regulated by different abiotic and biotic factors in response to land use intensity.

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We present the data of the 3rdresearch expedition of the European Dry Grasslands Group (EDGG), which was conducted in 2011 in two contrasting areas in NW Bulgarian mountains. The aim was to collect plot data for comparing Bulgarian dry grasslands with those of other parts of Europe in terms of syntaxonomy and biodiversity. We sampled 15 nested-plot series (0.0001–100 m²) and 68 normal plots(10 m²) covering the full variety of dry grassland types occurring in the Vratsa area (Balkan Mts.) and the Koprivshtitsa area (Sredna Gora Mt.). In the plots all vascular plants, terricolous non-vascular plants and a set of soil and other environmental parameters were determined. By applying modified TWIN-SPAN, we distinguished 10 floristically well characterised vegetation types at the association level. After comparison with the regional and European literature, we propose to place them within three classes and five orders: Festuco-Brometea with the orders Stipo pulcherrimae-Festucetalia pallentis (xerophilous dry grasslands of base-rich rocks; alliance Saturejion montanae), Brachypodietalia pinnate (meso-xeric, basiphilous grasslands; alliances Cirsio-Brachypodion pinnate and Chyrsopogono grylli-Danthonion calycinae),Calluno-Ulicetea with the order Nardetalia stricae (lowland to montane Nardus swards; alliance Violion caninae), and Koelerio-Corynephoretea with the orders Sedo-Scleranthetalia (open communities of skeleton-rich, acidic soils; alliance unclear) and Trifolioarvensis-Festucetalia ovinae(closed, meso-xeric, acidophilous grasslands; alliance Armerio rumelicae-Potentillion). The Violion caninae with the association Festuco rubrae-Genistelletum sagittalisis reported from Bulgaria for the first time, while the two occurring Koelerio-Corynephoretea communities are described as new associations (Cetrario aculeatae-Plantaginetum radicatae, Plantagini radicatae-Agrostietum capillaris). According to DCA the main floristic gradient was largely determined by soil conditions, differentiating the Festuco-Brometea communities on soils with high pH and high humus content from the Koelerio-Corynephoretea communities on acidic, humus-poor soils, while the Calluno-Ulicetea stands are the connecting link. At 10 m² Festuco-Brometea and Calluno-Ulicetea stands were richer in species across all investigated taxa and in vascular plants than Koelerio-Corynephoretea stands; the latter were richest in lichen species, while bryophyte richness did not differ significantly among syntaxa. Among the Bulgarian classes, the species-area relationships tended to be steepest in the Festuco-Brometea (i.e. highest beta diversity), but both alpha and beta diversity clearly fell behind the Festuco-Brometea communities in the Transylvanian Plateau, Romania, located less than 500 km north of the study region. Overall, our study contributes to a more adequate placement of the Bulgarian dry grasslands in the European syntaxonomic system and provides valuable data for large-scale analyses of biodiversity patterns

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The dog is the natural host of Staphylococcus pseudintermedius. Many research efforts are currently being undertaken to expand our knowledge and understanding of this important canine commensal and opportunistic pathogen. The objective of this review is to summarize the current knowledge of the species, including the latest research outcomes, with emphasis on taxonomy, diagnostics, ecology, epidemiology and pathogenicity. Despite the important taxonomic changes that have occurred over the past few years, the risk of misidentification in canine specimens is low and does not have serious consequences for clinical practice. Staphylococcus pseudintermedius carriage in the dog is more frequent and genetically heterogeneous compared with that of Staphylococcus aureus in man. It appears that these staphylococcal species have evolved separately through adaptation to their respective natural hosts and differ with regard to various aspects concerning ecology, population structure and evolution of antibiotic resistance. Further understanding of the ecology and epidemiology of S. pseudintermedius is hampered by the lack of a standard method for rapid and discriminatory typing and by the limited data available on longitudinal carriage and population structure of meticillin-susceptible strains. With regard to pathogenicity, it is only now that we are starting to explore the virulence potential of S. pseudintermedius based on genomic and proteomic approaches, and more research is needed to assess the importance of individual virulence factors and the possible existence of hypervirulent strains.

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Verbal thoughts (such as negative cognitions) and sensory phenomena (such as visual mental imagery) are usually conceptualised as distinct mental experiences. The present study examined to what extent depressive thoughts are accompanied by sensory experiences and how this is associated with symptom severity, insight of illness and quality of life. A large sample of mildly to moderately depressed patients (N = 356) was recruited from multiple sources and asked about sensory properties of their depressive thoughts in an online study. Diagnostic status and symptom severity were established over a telephone interview with trained raters. Sensory properties of negative thoughts were reported by 56.5% of the sample (i.e., sensation in at least one sensory modality). The highest prevalence was seen for bodily (39.6%) followed by auditory (30.6%) and visual (27.2%) sensations. Patients reporting sensory properties of thoughts showed more severe psychopathological symptoms than those who did not. The degree of perceptuality was marginally associated with quality of life. The findings support the notion that depressive thoughts are not only verbal but commonly accompanied by sensory experiences. The perceptuality of depressive thoughts and the resulting sense of authenticity may contribute to the emotional impact and pervasiveness of such thoughts, making them difficult to dismiss for their holder.

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Sound perception requires functional hair cell mechanotransduction (MET) machinery, including the MET channels and tip-link proteins. Prior work showed that uptake of ototoxic aminoglycosides (AG) into hair cells requires functional MET channels. In this study, we examined whether tip-link proteins, including Cadherin 23 (Cdh23), regulate AG entry into hair cells. Using time-lapse microscopy on cochlear explants, we found rapid uptake of gentamicin-conjugated Texas Red (GTTR) into hair cells from three-day-old Cdh23(+/+) and Cdh23(v2J/+) mice, but failed to detect GTTR uptake in Cdh23(v2J/v2J) hair cells. Pre-treatment of wildtype cochleae with the calcium chelator 1,2-bis(o-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid (BAPTA) to disrupt tip-links also effectively reduced GTTR uptake into hair cells. Both Cdh23(v2J/v2J) and BAPTA-treated hair cells were protected from degeneration caused by gentamicin. Six hours after BAPTA treatment, GTTR uptake remained reduced in comparison to controls; by 24 hours, drug uptake was comparable between untreated and BAPTA-treated hair cells, which again became susceptible to cell death induced by gentamicin. Together, these results provide genetic and pharmacologic evidence that tip-links are required for AG uptake and toxicity in hair cells. Because tip-links can spontaneously regenerate, their temporary breakage offers a limited time window when hair cells are protected from AG toxicity.

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A major objective in ecology is to find general patterns, and to establish the rules and underlying mechanisms that generate those patterns. Nevertheless, most of our current insights in ecology are based on case studies of a single or few species, whereas multi-species experimental studies remain rare. We underline the power of the multi-species experimental approach for addressing general ecological questions, e. g. on species environmental responses or on patterns of among-and within-species variation. We present simulations that show that the accuracy of estimates of between-group differences is increased by maximizing the number of species rather than the number of populations or individuals per species. Thus, the more species a multi-species experiment includes, the more powerful it is. In addition, we discuss some inevitable methodological challenges of multi-species experiments. While we acknowledge the value of single-or few-species experiments, we strongly advocate the use of multi-species experiments for addressing ecological questions at a more general level.