616 research outputs found

    Changes in eggshell ultrastructure of Falco naumanni and Tyto alba exposed to pesticides and polychlorinated biphenyls (PCBs)

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    Changes in the quality of eggs of birds exposed to environmental contaminants have been described, but few reports concern eggshell ultrastructure. In this study, infertile or addled Lesser Kestrels (Falco naumanni) and Barn owls (Tyto alba) eggs were collected from the polluted area of Gela plain (Sicily) during 2007, and compared in terms of organophosphate and organochlorine pesticides, and PCBs levels, and eggshell ultrastructure as determined by scanning electron microscopy. Pesticide and PCB residues in eggs were determined by Gas chromatography/ mass spectrometry (GC/MS) [GC Agilent 7890A/MS Agilent 5975C (Agilent technologies) using a DB-5 capillary column in the selected ion monitoring mode]. The GC/MS analysis revealed that eggs contained measurable amounts of some pesticides and PCBs. There was a low detection of organophosphate pesticides while the most abundant organochlorine residues detected were p,p’ DDT, p,p’ DDE, and Hexachlorobenzene. While, the most abundant PCBs detected congeners were PCB 138, 153, 170, 180, and 187. Although the general structure of the eggshell layers was maintained, the results showed ultrastructural differences in mammillary and palisade eggshell layers between high level and low level contaminated eggs in Tyto alba. Furthermore, mammillary cores of the eggshell had an increased distance between themselves with respect to well organized structures present in uncontaminated egg. In this paper we verify the presence of environmental contaminants in the eggs and document structural changes in bird of prey eggshells. The data could suggest that some contaminants can contribute to reduced reproductive performance (infertile or addled egg) by structural changes in the eggshell. The alteration in morphological disposition of mammillary cores could also suggest an impairment of gas exchange

    Potential association of specific Candida parapsilosis genotypes, bloodstream infections and colonization of health workers' hands

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    Fungal nosocomial infections continue to be a serious problem among hospitalized patients, decreasing quality of life and adding millions of euros to healthcare costs. The aim of this study was to describe the pattern of fungi associated with the hands of healthcare workers and to genotype Candida parapsilosis isolates in order to understand whether their high clinical prevalence stems from endemic nosocomial genotypes or from the real emergence of epidemiologically-unrelated strains. Approximately 39% (50/129) of healthcare workers were positive for yeasts and among 77 different fungal isolates recovered, C. parapsilosis was the most frequent (44/77; 57%). Twenty-seven diverse genotypes were obtained by microsatellite analysis of 42 selected blood and hand isolates. Most of the isolates from hands showed a new, unrelated, genotype, whereas a particular group of closely related genotypes prevailed in blood samples. Some of the latter genotypes were also found on the hands of healthcare workers, indicating a persistence of these clones within our hospital. C. parapsilosis genotypes from the hands were much more heterogeneous than clinical ones, thus reflecting a high genetic diversity among isolates, which is notably unusual and unexpected for this species

    Self-Affirmation Activates Brain Systems Associated with Self-Related Processing and Reward and is Reinforced by Future Orientation

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    Self-affirmation theory posits that people are motivated to maintain a positive self-view and that threats to perceived self-competence are met with resistance. When threatened, self-affirmations can restore self-competence by allowing individuals to reflect on sources of self-worth, such as core values. Many questions exist, however, about the underlying mechanisms associated with self-affirmation. We examined the neural mechanisms of self-affirmation with a task developed for use in a functional magnetic resonance imaging environment. Results of a region of interest analysis demonstrated that participants who were affirmed (compared with unaffirmed participants) showed increased activity in key regions of the brain’s self-processing (medial prefrontal cortex + posterior cingulate cortex) and valuation (ventral striatum + ventral medial prefrontal cortex) systems when reflecting on future-oriented core values (compared with everyday activities). Furthermore, this neural activity went on to predict changes in sedentary behavior consistent with successful affirmation in response to a separate physical activity intervention. These results highlight neural processes associated with successful self-affirmation, and further suggest that key pathways may be amplified in conjunction with prospection

    Global Brain Dynamics during Social Exclusion Predict Subsequent Behavioral Conformity

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    Individuals react differently to social experiences; for example, people who are more sensitive to negative social experiences, such as being excluded, may be more likely to adapt their behavior to fit in with others. We examined whether functional brain connectivity during social exclusion in the fMRI scanner can be used to predict subsequent conformity to peer norms. Adolescent males (n = 57) completed a two-part study on teen driving risk: a social exclusion task (Cyberball) during an fMRI session and a subsequent driving simulator session in which they drove alone and in the presence of a peer who expressed risk-averse or risk-accepting driving norms. We computed the difference in functional connectivity between social exclusion and social inclusion from each node in the brain to nodes in two brain networks, one previously associated with mentalizing (medial prefrontal cortex, temporoparietal junction, precuneus, temporal poles) and another with social pain (dorsal anterior cingulate cortex, anterior insula). Using predictive modeling, this measure of global connectivity during exclusion predicted the extent of conformity to peer pressure during driving in the subsequent experimental session. These findings extend our understanding of how global neural dynamics guide social behavior, revealing functional network activity that captures individual differences

    The Crystal Structure of a Cyanobacterial Water-Soluble Carotenoid Binding Protein

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    AbstractCarotenoids undergo a wide range of photochemical reactions in animal, plant, and microbial systems. In photosynthetic organisms, in addition to light harvesting, they perform an essential role in protecting against light-induced damage by quenching singlet oxygen, superoxide anion radicals, or triplet-state chlorophyll. We have determined the crystal structure of a water-soluble orange carotenoid protein (OCP) isolated from the cyanobacterium Arthrospira maxima at a resolution of 2.1 Ă…. OCP forms a homodimer with one carotenoid molecule per monomer. The carotenoid binding site is lined by a striking number of methionine residues. The structure reveals several possible ways in which the protein environment influences the spectral properties of the pigment and provides insight into how the OCP carries out its putative functions in photoprotection

    Applications of Direct Injection Soft Chemical Ionisation-Mass Spectrometry for the Detection of Pre-blast Smokeless Powder Organic Additives

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    Analysis of smokeless powders is of interest from forensics and security perspectives. This article reports the detection of smokeless powder organic additives (in their pre-detonation condition), namely the stabiliser diphenylamine and its derivatives 2-nitrodiphenylamine and 4-nitrodiphenylamine, and the additives (used both as stabilisers and plasticisers) methyl centralite and ethyl centralite, by means of swab sampling followed by thermal desorption and direct injection soft chemical ionisation-mass spectrometry. Investigations on the product ions resulting from the reactions of the reagent ions H3O+ and O2+ with additives as a function of reduced electric field are reported. The method was comprehensively evaluated in terms of linearity, sensitivity and precision. For H3O+, the limits of detection (LoD) are in the range of 41-88 pg of additive, for which the accuracy varied between 1.5 and 3.2%, precision varied between 3.7 and 7.3% and linearity showed R20.9991. For O2+, LoD are in the range of 72 to 1.4 ng, with an accuracy of between 2.8 and 4.9% and a precision between 4.5 and 8.6% and R20.9914. The validated methodology was applied to the analysis of commercial pre-blast gun powders from different manufacturers.(VLID)4826148Accepted versio

    Buffering Social Influence: Neural Correlates of Response Inhibition Predict Driving Safety in the Presence of a Peer

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    Adolescence is a period characterized by increased sensitivity to social cues, as well as increased risk-taking in the presence of peers. For example, automobile crashes are the leading cause of death for adolescents, and driving with peers increases the risk of a fatal crash. Growing evidence points to an interaction between neural systems implicated in cognitive control and social and emotional context in predicting adolescent risk. We tested such a relationship in recently licensed teen drivers. Participants completed an fMRI session in which neural activity was measured during a response inhibition task, followed by a separate driving simulator session 1 week later. Participants drove alone and with a peer who was randomly assigned to express risk-promoting or risk-averse social norms. The experimentally manipulated social context during the simulated drive moderated the relationship between individual differences in neural activity in the hypothesized cognitive control network (right inferior frontal gyrus, BG) and risk-taking in the driving context a week later. Increased activity in the response inhibition network was not associated with risk-taking in the presence of a risky peer but was significantly predictive of safer driving in the presence of a cautious peer, above and beyond self-reported susceptibility to peer pressure. Individual differences in recruitment of the response inhibition network may allow those with stronger inhibitory control to override risky tendencies when in the presence of cautious peers. This relationship between social context and individual differences in brain function expands our understanding of neural systems involved in top–down cognitive control during adolescent development

    Neural Responses to Exclusion Predict Susceptibility to Social Influence

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    Purpose Social influence is prominent across the lifespan, but sensitivity to influence is especially high during adolescence and is often associated with increased risk taking. Such risk taking can have dire consequences. For example, in American adolescents, traffic-related crashes are leading causes of nonfatal injury and death. Neural measures may be especially useful in understanding the basic mechanisms of adolescents\u27 vulnerability to peer influence. Methods We examined neural responses to social exclusion as potential predictors of risk taking in the presence of peers in recently licensed adolescent drivers. Risk taking was assessed in a driving simulator session occurring approximately 1 week after the neuroimaging session. Results Increased activity in neural systems associated with the distress of social exclusion and mentalizing during an exclusion episode predicted increased risk taking in the presence of a peer (controlling for solo risk behavior) during a driving simulator session outside the neuroimaging laboratory 1 week later. These neural measures predicted risky driving behavior above and beyond self-reports of susceptibility to peer pressure and distress during exclusion. Conclusions These results address the neural bases of social influence and risk taking; contribute to our understanding of social and emotional function in the adolescent brain; and link neural activity in specific, hypothesized, regions to risk-relevant outcomes beyond the neuroimaging laboratory. Results of this investigation are discussed in terms of the mechanisms underlying risk taking in adolescents and the public health implications for adolescent driving

    WebGIS implementation for dynamic mapping and visualization of coastal geospatial data: A case study of BESS project

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    Within an E.U.-funded project, BESS (Pocket Beach Management and Remote Surveillance System), the notion of a geographic information system is an indispensable tool for managing the dynamics of georeferenced data and information for any form of territorial planning. This notion was further explored with the creation of a WebGIS portal that will allow local and regional stake-holders/authorities obtain an easy remote access tool to monitor the status of pocket beaches (PB) in the Maltese Archipelago and Sicily. In this paper, we provide a methodological approach for the implementation of a WebGIS necessary for very detailed dynamic mapping and visualization of geospatial coastal data; the description of the dataset necessary for the monitoring of coastal areas, especially the PBs; and a demonstration of a case study for the PBs of Sicily and Malta by using the methodology and the dataset used during the BESS project. Detailed steps involved in the creation of the WebGIS are presented. These include data preparation, data storage, and data publication and transformation into geo-services. With the help of different Open Geospatial Consortium pro-tocols, the WebGIS displays different layers of information for 134 PBs including orthophotos, sed-imentological/geomorphological beach characteristics, shoreline evolution, geometric and morphological parameters, shallow water bathymetry, and photographs of pocket beaches. The WebGIS allows not only for identifying, evaluating, and directing potential solutions to present and arising issues, but also enables public access and involvement. It reflects a platform for future local and regional coastal zone monitoring and management, by promoting public/private involvement in addressing coastal issues and providing local public administrations with an improved technology to monitor coastal changes and help better plan suitable interventions
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