163 research outputs found

    LAVICAD: LAboratori VIrtual de Comunicacions Analògiques i Digitals

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    Mitjançant el present ajut s’ha ampliat l’aplicació en xarxa LAVICAD (LAboratori VIrtual de COmunicacions Analògiques i Digitals) que s’ofereix de forma integrada dins de la plataforma d’e-learning COM@WEB. LAVICAD és una eina programada en Java i Matlab i està formada per un conjunt de simuladors de la capa física de sistemes de comunicacions. Tots els simuladors es presenten en xarxa i es poden utilitzar pels estudiants des de qualsevol ordinador sense necessitat d’instal·lació de cap tipus de software especial. Durant el curs 2007 2008 s’han desenvolupat entre d’altres dos línies de treball. D’una banda s’ha programat l’applet que emula la capa física de la televisió digital terrestre, com a referent per a l’ensenyament de sistemes de comunicacions avançats. D’altra banda s’ha treballat en la programació de noves funcionalitats de l’eina LAVICAD, que permeten ajudar als professors en el seguiment i avaluació del treball continuat dels estudiants. En particular s’ha programat la generació d’una base de dades que conté la informació dels usuaris que s’han connectat i els resultats obtinguts a l’executar un determinat simulador. Les dues línies desenvolupades han de permetre durant l’actual curs, consolidar l’ús dels diferents simuladors per a la docència de les assignatures implicades al projecte.Peer Reviewe

    Insights into Structure-Activity Relationships of Somatostatin Analogs Containing Mesitylalanine.

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    The non-natural amino acid mesitylalanine (2,4,6-trimethyl-L-phenylalanine; Msa) has an electron-richer and a more conformationally restricted side-chain than that of its natural phenylalanine counterpart. Taking these properties into account, we have synthesized ten somatostatin analogs containing Msa residues in different key positions to modify the intrinsic conformational flexibility of the natural hormone. We have measured the binding affinity of these analogs and correlated it with the main conformations they populate in solution. NMR and computational analysis revealed that analogs containing one Msa residue were conformationally more restricted than somatostatin under similar experimental conditions. Furthermore, we were able to characterize the presence of a hairpin at the pharmacophore region and a non-covalent interaction between aromatic residues 6 and 11. In all cases, the inclusion of a D-Trp in the eighth position further stabilized the main conformation. Some of these peptides bound selectively to one or two somatostatin receptors with similar or even higher affinity than the natural hormone. However, we also found that multiple incorporations of Msa residues increased the life span of the peptides in serum but with a loss of conformational rigidity and binding affinity

    Presumed killers? Vultures, stakeholders, misperceptions, and fake news

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    Vultures and condors are among the most threatened avian species in the world due to the impacts of human activities. Negative perceptions can contribute to these threats as some vulture species have been historically blamed for killing livestock. This perception of conflict has increased in recent years, associated with a viral spread of partial and biased information through social media and despite limited empirical support for these assertions. Here, we highlight that magnifying infrequent events of livestock being injured by vultures through publically shared videos or biased news items negatively impact efforts to conserve threatened populations of avian scavengers. We encourage environmental agencies, researchers, and practitioners to evaluate the reliability, frequency, and context of reports of vulture predation, weighing those results against the diverse and valuable contributions of vultures to environmental health and human well-being. We also encourage the development of awareness campaigns and improved livestock management practices, including commonly available nonlethal deterrence strategies, if needed. These actions are urgently required to allow the development of a more effective conservation strategy for vultures worldwide.Peer reviewe

    Evidence for functional pre-coupled complexes of receptor heteromers and adenylyl cyclase

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    G protein-coupled receptors (GPCRs), G proteins and adenylyl cyclase (AC) comprise one of the most studied transmembrane cell signaling pathways. However, it is unknown whether the ligand-dependent interactions between these signaling molecules are based on random collisions or the rearrangement of pre-coupled elements in a macromolecular complex. Furthermore, it remains controversial whether a GPCR homodimer coupled to a single heterotrimeric G protein constitutes a common functional unit. Using a peptide-based approach, we here report evidence for the existence of functional pre-coupled complexes of heteromers of adenosine A2A receptor and dopamine D2 receptor homodimers coupled to their cognate Gs and Gi proteins and to subtype 5 AC. We also demonstrate that this macromolecular complex provides the necessary frame for the canonical Gs-Gi interactions at the AC level, sustaining the ability of a Gi-coupled GPCR to counteract AC activation mediated by a Gs-coupled GPCR

    Updated guidance on the management of COVID-19:from an American Thoracic Society/European Respiratory Society coordinated International Task Force (29 July 2020)

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    BACKGROUND: Coronavirus disease 2019 (COVID-19) is a disease caused by severe acute respiratory syndrome-coronavirus-2. Consensus suggestions can standardise care, thereby improving outcomes and facilitating future research. METHODS: An International Task Force was composed and agreement regarding courses of action was measured using the Convergence of Opinion on Recommendations and Evidence (CORE) process. 70% agreement was necessary to make a consensus suggestion. RESULTS: The Task Force made consensus suggestions to treat patients with acute COVID-19 pneumonia with remdesivir and dexamethasone but suggested against hydroxychloroquine except in the context of a clinical trial; these are revisions of prior suggestions resulting from the interim publication of several randomised trials. It also suggested that COVID-19 patients with a venous thromboembolic event be treated with therapeutic anticoagulant therapy for 3 months. The Task Force was unable to reach sufficient agreement to yield consensus suggestions for the post-hospital care of COVID-19 survivors. The Task Force fell one vote shy of suggesting routine screening for depression, anxiety and post-traumatic stress disorder. CONCLUSIONS: The Task Force addressed questions related to pharmacotherapy in patients with COVID-19 and the post-hospital care of survivors, yielding several consensus suggestions. Management options for which there is insufficient agreement to formulate a suggestion represent research priorities.status: Published onlin

    The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients

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    Background: Mortality due to COVID-19 is high, especially in patients requiring mechanical ventilation. The purpose of the study is to investigate associations between mortality and variables measured during the first three days of mechanical ventilation in patients with COVID-19 intubated at ICU admission. Methods: Multicenter, observational, cohort study includes consecutive patients with COVID-19 admitted to 44 Spanish ICUs between February 25 and July 31, 2020, who required intubation at ICU admission and mechanical ventilation for more than three days. We collected demographic and clinical data prior to admission; information about clinical evolution at days 1 and 3 of mechanical ventilation; and outcomes. Results: Of the 2,095 patients with COVID-19 admitted to the ICU, 1,118 (53.3%) were intubated at day 1 and remained under mechanical ventilation at day three. From days 1 to 3, PaO2/FiO2 increased from 115.6 [80.0-171.2] to 180.0 [135.4-227.9] mmHg and the ventilatory ratio from 1.73 [1.33-2.25] to 1.96 [1.61-2.40]. In-hospital mortality was 38.7%. A higher increase between ICU admission and day 3 in the ventilatory ratio (OR 1.04 [CI 1.01-1.07], p = 0.030) and creatinine levels (OR 1.05 [CI 1.01-1.09], p = 0.005) and a lower increase in platelet counts (OR 0.96 [CI 0.93-1.00], p = 0.037) were independently associated with a higher risk of death. No association between mortality and the PaO2/FiO2 variation was observed (OR 0.99 [CI 0.95 to 1.02], p = 0.47). Conclusions: Higher ventilatory ratio and its increase at day 3 is associated with mortality in patients with COVID-19 receiving mechanical ventilation at ICU admission. No association was found in the PaO2/FiO2 variation

    SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues

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    Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types

    Long-range angular correlations on the near and away side in p–Pb collisions at

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