4,222 research outputs found

    Academic community in the face of emergency situations: Sense of responsible togetherness and sense of belonging as protective factors against academic stress during covid-19 outbreak

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    In the face of emergency situations, such as a global pandemic, individuals rely on their personal resources, but also on community dimensions, to deal with the unprecedented changes and risks and to safeguard their well-being. The present study specifically addresses the role of individual resources and community dimensions with reference to academic communities facing COVID-19-related lockdowns and the changes that these have implied. An online questionnaire was administered to 1124 Italian University students. It detected their sense of belonging and of responsible togetherness with reference to their academic community through community dimensions, their student self-efficacy as an individual resource, and their academic stress—potentially stemming from studying in the middle of a pandemic. A multiple mediation model was been run with structural equation modeling. The results show that both the community dimensions associate with higher student self-efficacy and the sense of responsible togetherness, while also associating with lower academic stress. Moreover, student self-efficacy, in turn, associates with lower academic stress and mediates the relationships between both community dimensions and students’ academic stress levels. From these findings, the protective role that community dimensions can exert on an individual’s life becomes apparent. Building on this, further strategies should be implemented to reinforce personal and community resources in order to strengthen individuals against potentially stressful circumstances

    Habitat and ecological diversity influences the species-area relationship and the biogeography of the Sicilian archipelago's isopods

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    Terrestrial isopods are a well-studied invertebrate taxon in Sicily and in the surrounding islands (Maltese archipelago included). During the last 30 years their systematics, ecology and biogeography have been analysed by many authors. The size and the diverse geological origin of the Sicilian archipelago represents an ideal open laboratory in which to study some biogeographical patterns, such as the species-area relationship (SAR). Since many species show limited adaptation to broad physiological conditions and low mobility, and, therefore, their active dispersion is very slow, SAR can be a useful means to examine biogeographical patterns of isopods. Here we analyse their biogeography and whether there is a relationship between the area and the habitat variability of the island surveyed, and whether these factors have an either direct or coupled influence on species richness and ecology. Moreover, we evaluate a potential relationship between Isopoda species richness and the distance from the centre of dispersion (Sicily). Finally, we test for a difference in species and habitat richness between volcanic and non-volcanic islands. Our results show a positive correlation between the area and the habitat, more significant than that between the area and the species, leading us to speculate that habitat diversity has an influence on the SAR of isopods. We find a significantly higher richness of both species and habitats on non-volcanic islands. Finally, our analysis confutes the hypothesis that the number of isopod species on the archipelago's islets declines with the distance from Sicily. We suggest some potential explanations

    Habitat and ecological diversity influences the species-area relationship and the biogeography of the Sicilian archipelago’s isopods

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    Terrestrial isopods are a well-studied invertebrate taxon in Sicily and in the surrounding islands (Maltese archipelago included). During the last 30 years their systematics, ecology and biogeography have been analysed by many authors. The size and the diverse geological origin of the Sicilian archipelago represents an ideal open laboratory in which to study some biogeographical patterns, such as the species-area relationship (SAR). Since many species show limited adaptation to broad physiological conditions and low mobility, and, therefore, their active dispersion is very slow, SAR can be a useful means to examine biogeographical patterns of isopods. Here we analyse their biogeography and whether there is a relationship between the area and the habitat variability of the island surveyed, and whether these factors have an either direct or coupled influence on species richness and ecology. Moreover, we evaluate a potential relationship between Isopoda species richness and the distance from the centre of dispersion (Sicily). Finally, we test for a difference in species and habitat richness between volcanic and non-volcanic islands. Our results show a positive correlation between the area and the habitat, more significant than that between the area and the species, leading us to speculate that habitat diversity has an influence on the SAR of isopods. We find a significantly higher richness of both species and habitats on non-volcanic islands. Finally, our analysis confutes the hypothesis that the number of isopod species on the archipelago’s islets declines with the distance from Sicily. We suggest some potential explanations

    Radiomics in colorectal cancer patients

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    The main therapeutic options for colorectal cancer are surgical resection and adjuvant chemotherapy in non-metastatic disease. However, the evaluation of the overall adjuvant chemotherapy benefit in patients with a high risk of recurrence is challenging. Radiological images can represent a source of data that can be analyzed by using automated computer-based techniques, working on numerical information coded within Digital Imaging and Communications in Medicine files: This image numerical analysis has been named "radiomics". Radiomics allows the extraction of quantitative features from radiological images, mainly invisible to the naked eye, that can be further analyzed by artificial intelligence algorithms. Radiomics is expanding in oncology to either understand tumor biology or for the development of imaging biomarkers for diagnosis, staging, and prognosis, prediction of treatment response and diseases monitoring and surveillance. Several efforts have been made to develop radiomics signatures for colorectal cancer patient using computed tomography (CT) images with different aims: The preoperative prediction of lymph node metastasis, detecting BRAF and RAS gene mutations. Moreover, the use of delta-radiomics allows the analysis of variations of the radiomics parameters extracted from CT scans performed at different timepoints. Most published studies concerning radiomics and magnetic resonance imaging (MRI) mainly focused on the response of advanced tumors that underwent neoadjuvant therapy. Nodes status is the main determinant of adjuvant chemotherapy. Therefore, several radiomics model based on MRI, especially on T2-weighted images and ADC maps, for the preoperative prediction of nodes metastasis in rectal cancer has been developed. Current studies mostly focused on the applications of radiomics in positron emission tomography/CT for the prediction of survival after curative surgical resection and assessment of response following neoadjuvant chemoradiotherapy. Since colorectal liver metastases develop in about 25% of patients with colorectal carcinoma, the main diagnostic tasks of radiomics should be the detection of synchronous and metachronous lesions. Radiomics could be an additional tool in clinical setting, especially in identifying patients with high-risk disease. Nevertheless, radiomics has numerous shortcomings that make daily use extremely difficult. Further studies are needed to assess performance of radiomics in stratifying patients with high-risk disease

    Seasonal cycles of isoprene concentrations in the Amazonian rainforest

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    International audienceTropical forests are an important global source of volatile organic compounds (VOCs) and other atmospheric trace gases. The high biodiversity in tropical rainforests complicates the extrapolation of biogenic volatile organic compound (BVOC) emissions from leaf-level measurements to landscape and regional or global scales. In Amazônia, a significant fraction of the carbon emitted from the biosphere to the atmosphere is emitted in the form of BVOCs, and the knowledge of these emissions is important to our understanding of tropical and global atmospheric chemistry and carbon cycling. As part of the Large scale Biosphere-atmosphere experiment in Amazônia (LBA). VOC concentrations were measured at two sites near Santarém, Para State, Brazil. The two sites are located in the National Forest of Tapajós, the first corresponding to primary forest and the second to a forest, that was selectively logged. The samples were collected simultaneously at heights of 65 and 55 m (20 and 10 m above forest canopy, respectively). The average isoprene mixing ratio was 2.2?2.5 ppb at the two sites and the standard deviations within a site ranged from 1 to 1.2 ppb. A strong seasonality of isoprene mixing ratio was observed and associated with the wet and dry seasons. The lowest mixing ratios were found during the transition between the wet to dry season, while at the start of the biomass burning season the mixing ratios increase. A qualitative analysis of a one dimensional model demonstrates that the seasonal cycle in concentrations reflects changes in isoprene production by the ecosystem, not changes in boundary layer dynamics or chemistry. The magnitude of the cycle indicates that the physiological capacity of the ecosystem to emit isoprene may depend on water availability although phenological changes could also contribute to the observed variations. A simple 1-D model that assumes mean daytime isoprene fluxes of 1.5 mg m?2h?1 and 0.9 mg m?2h?1 scaled by an algorithm depending on precipitation at the primary forest and selectively logged sites, respectively, is able to reproduce the observed vertical gradients

    Sensitivity studies on the photolysis rates calculation in Amazonian atmospheric chemistry ? Part I: The impact of the direct radiative effect of biomass burning aerosol particles

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    International audienceThe impact of the direct radiative effect of the aerosol particles on the calculation of the photolysis rates and consequently on the atmospheric chemistry in regional smoke clouds due to biomass burning over the Amazon basin is addressed in this work. It explores a case study for 19 September 2002 at LBA-RACCI-SMOCC (The Large-Scale Biosphere-Atmosphere experiment in Amazonia ? Radiation, Cloud, and Climate Interactions ? Smoke, Aerosols, Clouds, Rainfall and Climate) pasture site in SW Amazonia. The Tropospheric Ultraviolet Visible radiation model (TUV) version 4.2, (Madronich et al., 1987) is used for the photolysis rates calculation considering the layer aerosol optical depth from the Coupled Aerosol Tracer Transport model to the Brazilian Regional Atmospheric Modeling System (CATT-BRAMS) (Freitas et al., 2005). A dynamical aerosol model (ProcĂłpio et al., 2003) is included in the radiative transfer model to take into account the high temporal variability of the aerosol optical thickness. This methodology is tested by comparing modeled and measured clear sky solar irradiances. The results show a good agreement with measured PAR radiation values. The actinic flux attenuation, for AOT (500 nm) values around 1.94, decreases the photolysis rates by about 70% in the presence of near-ground smoke aerosol and above the smoke layer the photolysis process tends to increase by about 40%. A simulation of the ozone production is carried out using a one-dimensional photochemical box model and comparisons with observation are shown

    Deep learning model for automatic prostate segmentation on bicentric T2w images with and without endorectal coil

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    Automatic segmentation of the prostate on Magnetic Resonance Imaging (MRI) is one of the topics on which research has focused in recent years as it is a fundamental first step in the building process of a Computer aided diagnosis (CAD) system for cancer detection. Unfortunately, MRI acquired in different centers with different scanners leads to images with different characteristics. In this work, we propose an automatic algorithm for prostate segmentation, based on a U-Net applying transfer learning method in a bi-center setting. First, T2w images with and without endorectal coil from 80 patients acquired at Center A were used as training set and internal validation set. Then, T2w images without endorectal coil from 20 patients acquired at Center B were used as external validation. The reference standard for this study was manual segmentation of the prostate gland performed by an expert operator. The results showed a Dice similarity coefficient >85% in both internal and external validation datasets.Clinical Relevance- This segmentation algorithm could be integrated into a CAD system to optimize computational effort in prostate cancer detection

    Constraint-induced movement therapy for upper extremities in people with stroke

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    Background In people who have had a stroke, upper limb paresis affects many activities of daily life. Reducing disability is therefore a major aim of rehabilitative interventions. Despite preserving or recovering movement ability after stroke, sometimes people do not fully realise this ability in their everyday activities. Constraint-induced movement therapy (CIMT) is an approach to stroke rehabilitation that involves the forced use and massed practice of the affected arm by restraining the unaffected arm. This has been proposed as a useful tool for recovering abilities in everyday activities. Objectives To assess the efficacy of CIMT, modified CIMT (mCIMT), or forced use (FU) for arm management in people with hemiparesis after stroke. Search methods We searched the Cochrane Stroke Group trials register (last searched June 2015), the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library Issue 1, 2015), MEDLINE (1966 to January 2015), EMBASE (1980 to January 2015), CINAHL (1982 to January 2015), and the Physiotherapy Evidence Database (PEDro; January 2015). Selection criteria Randomised control trials (RCTs) and quasi-RCTs comparing CIMT, mCIMT or FU with other rehabilitative techniques, or none. Data collection and analysis One author identified trials from the results of the electronic searches according to the inclusion and exclusion criteria, three review authors independently assessed methodological quality and risk of bias, and extracted data. The primary outcome was disability. Main results We included 42 studies involving 1453 participants. The trials included participants who had some residual motor power of the paretic arm, the potential for further motor recovery and with limited pain or spasticity, but tended to use the limb little, if at all. The majority of studies were underpowered (median number of included participants was 29) and we cannot rule out small-trial bias. Eleven trials (344 participants) assessed disability immediately after the intervention, indicating a non-significant standard mean difference (SMD) 0.24 (95% confidence interval (CI) -0.05 to 0.52) favouring CIMT compared with conventional treatment. For the most frequently reported outcome, arm motor function (28 studies involving 858 participants), the SMD was 0.34 (95% CI 0.12 to 0.55) showing a significant effect (P value 0.004) in favour of CIMT. Three studies involving 125 participants explored disability after a few months of follow-up and found no significant difference, SMD -0.20 (95% CI -0.57 to 0.16) in favour of conventional treatment. Authors' conclusions CIMT is a multi-faceted intervention where restriction of the less affected limb is accompanied by increased exercise tailored to the person\u2019s capacity. We found that CIMT was associated with limited improvements in motor impairment and motor function, but that these benefits did not convincingly reduce disability. This differs from the result of our previous meta-analysis where there was a suggestion that CIMT might be superior to traditional rehabilitation. Information about the long-term effects of CIMT is scarce. Further trials studying the relationship between participant characteristics and improved outcomes are required

    Development and implementation of a new biomass burning emissions injection height scheme (BBEIH v1.0) for the GEOS-Chem model (v9-01-01)

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    Biomass burning is a significant source of trace gases and aerosols to the atmosphere, and the evolution of these species depends acutely on where they are injected into the atmosphere. GEOS-Chem is a chemical transport model driven by assimilated meteorological data that is used to probe a variety of scientific questions related to atmospheric composition, including the role of biomass burning. This paper presents the development and implementation of a new global biomass burning emissions injection scheme in the GEOS-Chem model. The new injection scheme is based on monthly gridded Multi-angle Imaging SpectroRadiometer (MISR) global plume-height stereoscopic observations in 2008. To provide specific examples of the impact of the model updates, we compare the output from simulations with and without the new MISR-based injection height scheme to several sets of observations from regions with active fires. Our comparisons with Arctic Research on the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) aircraft observations show that the updated injection height scheme can improve the ability of the model to simulate the vertical distribution of peroxyacetyl nitrate (PAN) and carbon monoxide (CO) over North American boreal regions in summer. We also compare a simulation for October 2010 and 2011 to vertical profiles of CO over the Amazon Basin. When coupled with larger emission factors for CO, a simulation that includes the new injection scheme also better matches selected observations in this region. Finally, the improved injection height improves the simulation of monthly mean surface CO over California during July 2008, a period with large fires
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