329 research outputs found

    Classical-path integral adaptive resolution in molecular simulation: towards a smooth quantum-classical coupling

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    Simulations that couple different classical molecular models in an adaptive way by changing the number of degrees of freedom on the fly, are available within reasonably consistent theoretical frameworks. The same does not occur when it comes to classical-quantum adaptivity. The main reason for this is the difficulty in describing a continuous transition between the two different kind of physical principles: probabilistic for the quantum and deterministic for the classical. Here we report the basic principles of an algorithm that allows for a continuous and smooth transition by employing the path integral description of atoms.Comment: 8 pages 4 figure

    Gender quota on corporate boards in Italy: spillover effects and financial performance

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    This paper analyzes the impact of the introduction of mandatory gender quotas for the boards of directors of listed firms and state-participated companies (LP) in Italy. It investigates its effects on firms directly targeted by the new regulation as well as its indirect effects on firms that are not. To this aim, we use difference-in-difference and panel fixed-effects estimations. Our main results are that quotas directly increased female presence on boards of LP companies and produced some “positive spillover effects”, i.e., a higher proportion of women in top executive positions in LP firms and a higher share of women on boards of non-listed firms and non-participated firms (NLNP), even if the latter were not targeted by the law. We also find evidence for a positive impact of higher board gender diversity on firm performance in specific conditions, such as boards of small size and NLNP companies

    The G\=oMartini approach: Revisiting the concept of contact maps and the modelling of protein complexes

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    We present a review of a series of contact maps for the determination of native interactions in proteins and nucleic acids based on a distance-threshold. Such contact maps are mostly based on physical and chemical construction, and yet they are sensitive to some parameters (e.g. distances or atomic radii) and can neglect some key interactions. Furthermore, we also comment on a new class of contact maps that only requires geometric arguments. The contact map is a necessary ingredient to build a robust G\=oMartini model for proteins and their complexes in the Martini 3 force field. We present the extension of a popular structure-based G\=o-like approach for the study of protein-sugar complexes, and also limitations of this approach are discussed. The G\=oMartini approach was first introduced by Poma et al. J. Chem. Theory Comput. 2017, 13(3), 1366-1374 in Martini 2 force field and recently, it has gained the status of gold-standard for protein simulation undergoing conformational changes in Martini 3 force field. We discuss several studies that have provided support to this approach in the context of the biophysical community.Comment: 19 pages, 3 figure

    'He just gave up': an exploratory study into the perspectives of paid carers on supporting older people living in care homes with depression, self-harm, and suicide ideation and behaviours

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    This study explored the concept of ‘giving up’ from the perspective of care staff working in care homes, and their everyday communication and hidden knowledge concerning what they think about this taboo topic and the context it reflects. Moving to a care home is a major transition where cumulative losses can pose risks to mental health in later life. If not recognised, this vulnerability can lead to depression which extends to suicide ideation and behaviours in the form of self-harm and self-neglect. Care homes are a significant place of care until death, yet a discourse of silence means that self-harm and suicide is under-reported or not attended to with specialist expertise. The layperson’s concept of an older person ‘giving up’ on life is hardly discussed in the literature. This co-produced qualitative study used an inductive approach to explore this phenomenon through focus groups with 33 care staff across four care homes in South-East England. Findings paint a complex picture, highlighting tensions in providing the right support and creating spaces to respond to such challenging situations. ‘Giving up’ requires skilled detailed assessment to respond to risks alongside improved training and support for paid carers, to achieve a more holistic strategy which capitalises on significant relationships within a wider context

    Targeting Macrophages and Synoviocytes Intracellular Milieu to Augment Anti-Inflammatory Drug Potency

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    Using a preclinical in vivo model of arthritis and the gold standard disease-modifying anti-rheumatic drug, methotrexate, pH-responsive phosphorylcholine polymersomes, elicit both anti-inflammatory and anti-arthritic therapeutic efficacy, while drastically minimizing off-target toxicity. First, the selective accumulation of polymersomes within synovium of inflamed joints. Second, the polymersomes targeting ability toward activated macrophages and synoviocytes, via scavenger receptors, allow their uptake via endocytosis. And third, the polymersomes pH-responsiveness enables the drug escape from early endosomes and hence its intracellular milieu delivery. On-site augment of methotrexate loaded polymersomes enable the complete abrogation of synovial inflammation and prevent the disease progression and severity. Overall, in vitro and in vivo investigations reveal the potential of polymersomes as a promising nanotherapy for treating arthritic inflammation

    Long-Standing International Cooperation in Parasitology Research: A Summary of 35 Years of Activities in the Bolivian Chaco

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    The Bolivian Chaco is a semiarid region with a low population density, situated in the southeast part of the Plurinational State of Bolivia. Here, despite the improvements of the last 15 years, poverty remains high in rural areas, where social vulnerability is widespread. The Guaraní ethnic group often lives in isolated communities with a low standard of hygiene and sanitation. This epidemiological scenario favors the spread of transmissible diseases, including several parasitic infections belonging to the neglected tropical diseases (NTDs) group. In this area, a long-standing research activity, built upon the synergism between local and foreign institutions, has been established since the late 1980s and helps to fill in the knowledge gap about the epidemiology dynamics of soil-transmitted helminths, vector-borne parasites, and other parasitic diseases. A 35-year history of cooperation programs in parasitology research has contributed to informing local health authorities of the NTD burden in the Bolivian Chaco and, ultimately, supports local healthcare providers in the management of parasitic diseases

    Performance Characteristics of qPCR Assays Targeting Human- and Ruminant-Associated Bacteroidetes for Microbial Source Tracking across Sixteen Countries on Six Continents

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    Numerous quantitative PCR assays for microbial fecal source tracking (MST) have been developed and evaluated in recent years. Widespread application has been hindered by a lack of knowledge regarding the geographical stability and hence applicability of such methods beyond the regional level. This study assessed the performance of five previously reported quantitative PCR assays targeting human-, cattle-, or ruminant-associated Bacteroidetes populations on 280 human and animal fecal samples from 16 countries across six continents. The tested cattle-associated markers were shown to be ruminant-associated. The quantitative distributions of marker concentrations in target and nontarget samples proved to be essential for the assessment of assay performance and were used to establish a new metric for quantitative source-specificity. In general, this study demonstrates that stable target populations required for marker-based MST occur around the globe. Ruminant-associated marker concentrations were strongly correlated with total intestinal Bacteroidetes populations and with each other, indicating that the detected ruminant-associated populations seem to be part of the intestinal core microbiome of ruminants worldwide. Consequently tested ruminant-targeted assays appear to be suitable quantitative MST tools beyond the regional level while the targeted human-associated populations seem to be less prevalent and stable, suggesting potential for improvements in human-targeted methods

    Assessing the determinants of stillbirths and early neonatal deaths using routinely collected data in an inner city area

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    BACKGROUND: Within the UK there is considerable variation in the perinatal mortality rate. The objective of this study was to assess the factors associated with stillbirths and early neonatal deaths (ENND) and the suitability of the available databases in a health authority with one of the highest rates in the country. METHODS: Two case-control studies were carried out in three hospital trusts in the Lambeth, Southwark and Lewisham Health Authority, London, using routinely collected information. In one study, 342 stillbirths and 1,368 controls were included, and in the other study, 205 ENND and 820 controls were included. In the two studies cases and controls were matched for hospital trust. RESULTS: A birthweight below 1.5 kg was found in 54% and 48% of the stillbirths and ENND, respectively. More than 50% of the cases, stillbirths and ENND, had a length of gestation below 32 weeks. Length of gestation, birthweight, emergency caesarean section and age of the mother were associated with stillbirths. Birthweight and Apgar score at 1 minute as a categorical variable were associated with ENND. There was no direct evidence of an effect of social deprivation on the outcomes of interest. CONCLUSION: Birthweight and length of gestation are the most influential factors on an unfavourable outcome. Conception at an older age has a serious impact on stillbirth rates. In our health authority social disadvantage did not have a direct impact on stillbirth and ENND. Maternity information systems should collect routine data on fewer variables, but their quality in terms of value, standardization and completion rates must improve
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