538 research outputs found

    On the hadronic origin of the TeV radiation from GRB 190114C

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    The recently discovered TeV emission from Gamma-Ray Bursts (GRBs) hints towards a possible hadronic origin of this radiation component. We developed a Monte Carlo (MC) simulation reproducing the kinematics of photo-hadronic interactions at internal shocks, including the pair production process that the secondary gamma rays undergo in the GRB jet. We find that sub-TeV observations of GRB 190114C can be reproduced by a baryonic energy content comparable to that in sub-GeV photons and a bulk Lorentz factor Γ=100\Gamma=100, with a ms variability timescale. Neutrino flux predictions by the model are found to be consistent with experimental upper limits set by ANTARES and IceCube

    Análisis de los distintos procesos de interacción de los electrones con los componentes atmosféricos

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    En este trabajo se hace un análisis de los diferentes procesos de interacción de los electrones con los componentes atmosféricos determinándose para cada energía cuáles son predominantes y cuáles pueden ser despreciados. Como resultado se obtiene un modelo simplificado de la degradación energética de los electrones que permite además un ahorro importante en tiempo de computación.An analysis of the different excitation processes by which electrons interact with the atmospheric components is presented. The energy ranges in which they predominate or they can be neglected are determined. As a result, a simplified model of the energy degradation of electrons is- obtained that also implies a considerable reduction in the computing time.Asociación Argentina de Geofísicos y Geodesta

    UAV LOW-COST SYSTEM FOR EVALUATING AND MONITORING THE GROWTH PARAMETERS OF CROPS

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    New generation sensors (RGB, thermal, NIR and multispectral cameras) on unmanned aerial vehicles are continuously being developed for precision farming applications. In particular, this paper presents a study and an experimentation linked to the determination of viticulture growth indices by integrating the innovative techniques of digital photogrammetry from UAV platform, GPS satellite technique and traditional measures. Furthermore we demonstrate that the products from the processed raw-data represent good quality support to determine health state of the crop, and provide in addition a quantitative evaluation of the observed data. Through the use of such a technology it is possible to improve productivity between 15% and 17%, reducing the market price of the product and the costs of control and management. In particular, during the monitoring campaign lasting three years from 2015 to 2017, it was possible to observe that vine cultivation increased the growth index by about 12% following the corrections resulting from the critical interpretation of the results

    Mentalizing subtypes in eating disorders: A latent profile analysis

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    Background: Mentalizing, the mental capacity to understand oneself and others in terms of mental states, has been found to be reduced in several mental disorders. Some studies have suggested that eating disorders (EDs) may also be associated with impairments in mentalizing. The aim of this work is to investigate the possible presence of mentalizing subtypes in a sample of patients with EDs. Method: A sample of patients with eating disorders (N = 157) completed a battery of measures assessing mentalization and related variables, including the Reflective Functioning Questionnaire (RFQ), the Difficulties in Emotion Regulation Strategies (DERS), the Interpersonal Reactivity Index (IRI). Clinicians rated patients in relation to imbalances in different dimensions of mentalization to prementalizing modes and attachment style by using the Mentalization Imbalances Scale, the Modes of Mentalization Scale (MMS), and the Adult Attachment Questionnaire. A latent profile analysis was conducted to test the possible presence of different subgroups. MANOVA was used to test the possible differences between the four mentalizing profiles in relation to emotion dysregulation (DERS), empathy (IRI), and adequate and impairments in mentalizing (MMS and RFQ). Results: The latent profile analysis suggested the presence of four different profiles in relation to impairments in the dimensions of mentalization: (1) affective/self/automatic imbalances, (2) external imbalance, (3) cognitive/self/automatic imbalances, and (4) cognitive/other/automatic imbalances. Patients belonging to profile 1 are characterized by the prevalence of affective mentalization that overwhelms the capacity to reflect on mental states with an imbalance on the self-dimension; profile 2 patients are excessively focused on the external cues of mentalization; profile 3 patients are characterized by an over-involvement on the cognitive and self-facets of mentalization, with an impairment in adopting the other mind perspective; and profile 4 patients have similar impairments compared to profile 3 patients but with an excessive focus on others and deficits in self-reflection. These profiles were heterogeneous in terms of EDs represented in each group and presented significant differences on various variables such as attachment style, emotion dysregulation, empathy, interpersonal reactivity, and reflective function. This study represents, so far, the first work that confirms the presence of different mentalizing patterns in ED patients. Conclusions: ED patients can be classified in relation to impairments in different dimensions of mentalization above and beyond ED diagnosis

    Chitin and Its Derivatives: Nanostructured Materials from Different Marine and Terrestrial Sources

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    Chitin is a very abundant polysaccharide that can be obtained from well-known marine sources (crustaceans), but also from terrestrial sources (mushrooms and insects). In the case where animal sources are considered, the material can be obtained by much abundant food or feeding waste. The extraction methodologies were not developed with similar technical readiness levels considering the different sources and the further conversion to chitin nanofibrils and chitosan is also under study, enabling the production of products differentiated for their macromolecular structures and morphology.Chitin nanofibrils from sea food sources were used in sanitary, cosmetic and packaging applications, where their anti-microbial properties and good biocompatibility were very useful. Chitin from mushrooms and sea food was used as starting material in possible coatings for cellulosic and bioplastic substrates. Currently chitin from insects (Hermetia Illucens) is also under study as well as the methodologies for extracting derivatives from it. Infrared analysis is an interesting technique to compare chitins, chitin nanofibrils and chitosan from different sources as well as electron microscopy for studying their morphology. The derivatives of chitin, such as chitosan and chitin nanofibrils, show anti-microbial properties. Hence, their use in several applications, ranging from packaging to sanitary and cosmetics, can conjugate high performance novel products with a reduced environmental concern. The comparison between chitin derivatives from different sources is very useful to address the biopolymers to specific applications, including the agricultural sector. While more and more applications for chitin derivatives will be developed, differences between them should be clarified and correlated to the sources, the methodologies of their production and their physical-chemical properties

    Time spent with HIV-RNA ≤ 200 copies/ml in a cohort of people with HIV during the U=U era

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    Objective: Zero risk of linked HIV transmission in sero-discordant couples when the HIV-infected partner had viral load (VL) <200 copies/mL (‘U status’) was found in observational studies. We aimed at estimating the proportion of time in which ‘U status’ was maintained and identifying factors associated with the risk of losing it. / Design: Observational cohort study. / Methods: We included participants in the ICONA cohort who had reached an established ‘U status’ (VL≤200 copies/mL for >6 months) as of December 2010. The outcome was the number of person-days of follow up (PDFU) above a VL>200 copies/ml, relative to the total number of PDFU observed. A logistic regression model was used to identify factors independently associated with the risk of losing ‘U status’. / Results: 8,241 persons living with HIV were included in the analysis who contributed 12,670,888 PDFU. Of these, 1,648 (20%) were female, 768 (9%) were people who inject drugs (PWID), and 2,066 (25%) were foreing-born. The median of VL measurements was 9 (IQR: 4–15). Overall, only 3.1% of PDFU were observed when VL was >200 copies/mL. The proportion of PDFU with VL>200 cp/ml was higher than average in females (5.3%), unemployed (5.4%), PWID (4.7%), and in people with>3 previous virologic failures (6.3%). These variables were significant predictors of losing ‘U status’ in the multivariable logistic regression. / Conclusions: Our results reinforce the validity of the U=U message in real-world setting. However, we identified subsets of our study population at higher risk of losing the ‘U status’ for whom additional efforts are needed

    Change of the ice rheology with climatic transitions – implication on ice flow modelling and dating of the EPICA Dome C core

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    International audienceThe study of the distribution of the crystallographic orientations (the fabric) along ice cores supplies information on the past and current ice flows of ice-sheets. Beside the usually observed formation of a vertical single maximum fabric, the EPICA Dome Concordia ice core (EDC) shows an abrupt and unexpected strenghtening of its fabric during termination II around 1750 m depth. Such strengthenings were already observed for sites located on an ice-sheet. This suggests that horizontal shear could occur along the EDC core. Moreover, the change in the fabric leads to a modification of the viscosity between neighbouring ice layers. Through the use of an anisotropic ice flow model, we quantify the change in viscosity and investigate its implication on ice flow and dating
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