1,237 research outputs found

    Blind protein structure prediction using accelerated free-energy simulations.

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    We report a key proof of principle of a new acceleration method [Modeling Employing Limited Data (MELD)] for predicting protein structures by molecular dynamics simulation. It shows that such Boltzmann-satisfying techniques are now sufficiently fast and accurate to predict native protein structures in a limited test within the Critical Assessment of Structure Prediction (CASP) community-wide blind competition

    Asymptomatic patients as a source of transmission of COVID-19 in homeless shelters

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    Objectives: Asymptomatic carriers account for over a third of all Coronavirus Disease 19 (COVID-19) cases and are characterized by the absence of symptoms but the same infectivity as symptomatic infections. The high percentage of asymptomatic COVID-19 patients is significant in settings with specific vulnerabilities, such as homeless shelters, where the consequences of an outbreak may be dramatic. In this work, we briefly report our experience on residents and staff of homeless shelters in the City of Rome, Italy, with a particular focus on asymptomatic transmission, and compare it with the available evidence. Methods: We performed routine Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) nasopharyngeal swab tests in all residents and staff of homeless shelters managed by the Eleemosynaria Apostolica of the Vatican City State in the city of Rome, Italy, in addition to daily symptom screening, body temperature monitoring, and application of other prevention measures. Results: We evaluated 298 persons and identified twelve positive cases (4%). Most of the positive cases (75%) were asymptomatic, while only three patients reported symptoms that included fever, diarrhea, and cough. Conclusions: Our data confirm the importance of early identification of asymptomatic carriers that could, in vulnerable conditions such as homeless shelters, spread the infection and cause outbreaks with severe consequences on individual and public health

    Blood Oxygen Level-Dependent Activation of the Primary Visual Cortex Predicts Size Adaptation Illusion

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    In natural scenes, objects rarely occur in isolation but appear within a spatiotemporal context. Here, we show that the perceived size of a stimulus is significantly affected by the context of the scene: brief previous presentation of larger or smaller adapting stimuli at the same region of space changes the perceived size of a test stimulus, with larger adapting stimuli causing the test to appear smaller than veridical and vice versa. In ahumanfMRI study, we measured the blood oxygen level-dependent activation (BOLD) responses of the primary visual cortex (V1) to the contours of large-diameter stimuli and found that activation closely matched the perceptual rather than the retinal stimulus size: the activated area of V1 increased or decreased, depending on the size of the preceding stimulus. A model based on local inhibitory V1 mechanisms simulated the inward or outward shifts of the stimulus contours and hence the perceptual effects. Our findings suggest that area V1 is actively involved in reshaping our perception to match the short-term statistics of the visual scene

    Homeless persons and migrants in precarious housing conditions and COVID-19 pandemic: peculiarities and prevention strategies

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    Homeless persons and migrants in precarious housing conditions are vulnerable populations that have been peculiarly impacted by the Coronavirus Disease 19 (COVID-19) pandemic. These populations are more at risk of contracting COVID-19 as they often find it difficult to adhere to public health directives and, if exposed, may be more susceptible to illness or death due to the higher prevalence of underlying physical and mental comorbidities compared to the general population. In addition, vulnerable populations may have limited access to essential diagnostics and treatments, thus leading to untreated COVID-19 cases and their development into more severe forms. Health, social and government agencies should collaborate to develop services that support these communities, in accordance with the World Health Organization principles. Migrant and homeless centers have a central role, as they provide a significant contribution to prevent infection spread and favor access to early medical treatment to those affected, thus preventing more severe forms of infection

    Hydrothermal Carbonization of Oat in a Lab-Scale Batch Reactor

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    Biomass as feedstock for renewable energy and biomaterials production is of great importance to tackle energy, economic and environmental issues. Biomass can be processed in several ways depending on its composition, moisture content and availability. Hydrothermal Carbonization (HTC) is one possible option to deal with the biomass streams. In this study, oat was processed in a lab-scale stirred-batch HTC reactor to evaluate the effect of reaction temperature and residence time on the composition and yield of hydrochar obtained during the process. The results demonstrate that these operating parameters strongly affect the characteristics and the amount of the hydrochar produced. The results indicate that the increasing of the HTC severity conditions produces an enrichment of hydrochar in carbon content up to 72.8%. On the other hand, the hydrochar yield decreases from 0.85 to 0.56 g/g as the severity factor increases from 0.11 to 0.37

    Inhibition of Neuromuscular Contractions of Human and Rat Colon by Bergamot Essential Oil and Linalool: Evidence to Support a Therapeutic Action

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    Bergamot essential oil (BEO) added to food and drink promotes a citrus flavour. Folklore suggests benefits on gastrointestinal functions but with little supporting evidence. BEO and major constituents (linalool, limonene, linalyl acetate) were therefore examined for any ability to influence neuromuscular contractions of human and rat colon. Circular muscle strips (macroscopically-normal human colon obtained following ethical approval at cancer surgery; Sprague–Dawley rats) were suspended in baths (Krebs solution; 37 °C; 5% CO2 in O2) for measurement of neuronally-mediated contractions (prevented by tetrodotoxin or atropine) evoked by electrical field stimulation (5 Hz, 0.5 ms pulse width, 10s/minute, maximally-effective voltage), or contractions evoked by KCl (submaximally-effective concentrations). BEO and each constituent concentration dependently inhibited neuronally-mediated and KCl-induced contractions. In human: apparent pIC50 for BEO (volume/volume Krebs), respectively, 3.8 ± 0.3 and 4.4 ± 0.3; Imax 55.8% ± 4.2% and 37.5% ± 4.2%. For the constituents, the rank order of potency differed in human (linalool > limonene >> linalyl-acetate) and rat colon (linalyl-acetate > limonene = linalool), but rank order of efficacy was similar (linalool >> (BEO) = linalyl-acetate >> limonene). Thus, linalool had high efficacy but greater potency in human colon (Imax 76.8% ± 6.9%; pIC50 6.7 ± 0.2; n = 4) compared with rat colon (Imax 75.3% ± 1.9%; pIC50 5.8 ± 0.1; n = 4). The ability of BEO and linalool to inhibit human colon neuromuscular contractility provides a mechanism for use as complementary treatments of intestinal disorders

    Visual BOLD Response in Late Blind Subjects with Argus II Retinal Prosthesis

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    Retinal prosthesis technologies require that the visual system downstream of the retinal circuitry be capable of transmitting and elaborating visual signals. We studied the capability of plastic remodeling in late blind subjects implanted with the Argus II Retinal Prosthesis with psychophysics and functional MRI (fMRI). After surgery, six out of seven retinitis pigmentosa (RP) blind subjects were able to detect high-contrast stimuli using the prosthetic implant. However, direction discrimination to contrast modulated stimuli remained at chance level in all of them. No subject showed any improvement of contrast sensitivity in either eye when not using the Argus II. Before the implant, the Blood Oxygenation Level Dependent (BOLD) activity in V1 and the lateral geniculate nucleus (LGN) was very weak or absent. Surprisingly, after prolonged use of Argus II, BOLD responses to visual input were enhanced. This is, to our knowledge, the first study tracking the neural changes of visual areas in patients after retinal implant, revealing a capacity to respond to restored visual input even after years of deprivation

    Health and social conditions of children living in disadvantaged neighborhoods in the city of Rome, Italy

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    OBJECTIVE: The number of children living in socio-economically disadvantaged neighborhoods in developed countries is constantly growing, resulting in important implications for children's development, physical and psychological health and increased future disparities. In this study, we explored several key elements of children living in poor neighborhoods, such as demographic characteristics, access to public health assistance and school, and availability of housing and basic hygienic conditions.PATIENTS AND METHODS: The study included 711 children aged 0-17 years referring to primary care services in the suburbs of the city of Rome, Italy.RESULTS: Most children were born in Italy, while almost none of their parents were. Nearly 60% of the children did not have access to basic pediatric care, causing possible misdiagnosis and delayed treatment for acute and chronic conditions. A smaller percentage of the children did not have access to basic housing (8%) and hygienic facilities, such as heating, running water, and refrigerator (3.2%), leading to malnutrition, isolation and poor physical and psychological development.CONCLUSIONS: This study confirms a critical condition for children living in disadvantaged neighborhoods, whose vulnerability is further worsened by the limited access to paediatric health assistance and, in some cases, to basic facilities with a severe impact on their physical and psychological development
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