Simulación de la Pequeña Edad de Hielo usando el modelo EdGCM

La Pequeña Edad de Hielo fue un período frío que abarcó desde mediados del siglo XIV hasta mediados del siglo XIX. Durante ese tiempo ocurrieron tres pulsos de temperaturas extremadamente bajas. En el presente trabajo se analiza el segundo de ellos denominado Mínimo de Maunder (MM) que ocurrió entre 1645 y 1715. La disminución de la actividad solar, el aumento de la actividad volcánica y el cambio en las concentraciones de Dióxido de Carbono fueron sus principales forzantes. Mediante el Modelo de Circulación General EdGCM se realizan distintas simulaciones de las condiciones climáticas, con el fin de obtener escenarios de respuesta de la temperatura y la circulación atmosférica a los cambios producidos en la irradiancia y los gases invernadero, en especial del CO2. A su vez, son calculadas por medio de los re-análisis del NCEP/NCAR, las diferencias climáticas entre años de máxima y mínima irradiancia a fin de compararlas con las diferencias ocurridas entre las condiciones actuales y del MM dadas por el modelo. Las anomalías anuales de temperatura, entre el MM y las condiciones de fines del siglo XX, son negativas para ambos hemisferios y las anomalías de temperatura resultan más intensas para el semestre frío. Además, sobre Sudamérica, se observa un centro más intenso en latitudes subtropicales y desde el centro hasta el sur de Patagonia. El patrón de enfriamiento simulado por el modelo concuerda, en algunos casos aún en magnitud, con la información de proxy datos de algunas regiones de Sudamérica. La componente zonal del oeste se muestra desplazada hacia menores latitudes durante el MM. Los campos de anomalías de circulación atmosférica simulados para el MM, muestran un patrón, en latitudes medias y altas, en que alternan tres ó cuatro centros positivos con negativos, el cual concuerda con una mayor componente meridional del flujo. Ambos resultan patrones parecidos con los que ocurren actualmente durante eventos El Niño.The Little Ice Age (LIA) was a cold period that ranged from taken part of the century XIV until taken part of the century XIX. In the period occurred three pulses of minimum values of temperature and will study the second of them comprised between 1645-1715 designated Maunder Minimum (MM). The decrease of the solar activity, the increase of the volcanic activity and the change in the Carbon Dioxide concentrations were the main forcings during these periods. In present work we realize distinct simulations of the climatic conditions for the South Hemisphere, by means of the General Circulation Model EdGCM, with the end to obtain stages of answer to the changes of irradiance and CO2 for the MM. At the same time, the climatic differences between years of maxima and minimum values of sunshine during the century XX determined by means of the results of the re-analysis of the NCEP/NCAR, compare with the differences between the current conditions and the ones of the MM, simulated by the model. The anomalies between the XX century and the MM obtained with the EdGCM are in agree qualitatively, and also quantitatively in some locations, with the proxy data information for various regions of the Hemisphere South. The annual temperature anomalies, between the MM and the 20th century ending conditions, are negative for both hemispheres and the temperature anomalies result more intense on semester November-April. Furthermore, over South America, shows a more intense centre in subtropical latitude and central and south Patagonia. The cold pattern obtained by the model is in agreement, on magnitude too, with proxy information obtained in some South America regions. The westerly wind component undergoes a shift to lower latitudes during the MM. The atmospheric circulation anomalies obtained in the simulations, show a pattern, over middle and high latitudes, where alternate three or four positive and negative anomaly centres, which is in agreement with a greater meridional component of the flux. Both patterns are similar to those present during El Niño events.Asociación Argentina de Geofísicos y Geodesta

Contribution à l’étude de l’hépatite contagieuse du chien. Ill. - Essai de «diagnostic enzymatique » de l'infection expérimentale du chien

Compagnucci M., Pilet Ch., Chevet A., Goret Pierre. Contribution à l’étude de l’hépatite contagieuse du Chien. III. Essai de «diagnostic enzymatique» de l’infection expérimentale du Chien. In: Bulletin de l'Académie Vétérinaire de France tome 116 n°1, 1963. pp. 35-39

Series de precipitación de la región centro oeste y sus variaciones

Se analizan las series de precipitaciones estivales de 8 estaciones meteorológicas de la región Centro Oeste de la Argentina mediante la aplicación de filtros de baja y alta frecuencias. Se establecen las matrices de correlación de las series originales y filtradas y se efectúa un análisis de enlace (linkage). Los resultados muestran que la región presenta igual variabilidad,1as ondas lar gas que la componen se encuentran en fase, con un período de 18 años aproximadamente por lo que están altamente correlacionadas. Las ondas cortas, más representativas del microclima de cada estación, no se correlacionan.The records of summer rainfall from 8 meteorological stations in the Central West region of Argentina has been analyzed by means of low-pass and high-pass filters. Linkage analysis has also been applied to the correlation matrix of filtered and unfiltered data. The results show that the region has equal variabllity, the long waves components are in face with a period of 18 years aproximately and high correlation coefficients. The short waves are more representatives of the microclima of each station. They are not correlated.Asociación Argentina de Geofísicos y Geodesta

Ethical perspectives on surgical video recording for patients, surgeons and society: systematic review

Background Operating-room audiovisual recording is increasingly proposed, although its ethical implications need elucidation. The aim of this systematic review was to examine the published literature on ethical aspects regarding operating-room recording. Methods MEDLINE (via PubMed), Embase, and Cochrane databases were systematically searched for articles describing ethical aspects regarding surgical (both intracorporeal and operating room) recording from database inception to the present (the last search was undertaken in July 2022). Medical subject headings used in the search included ‘operating room’, ‘surgery’, ‘video recording’, ‘black box’, ‘ethics’, ‘consent’, ‘confidentiality’, ‘privacy’, and more. Title, abstract, and full-text screening determined relevance. The quality of studies was assessed using Centre for Evidence-Based Medicine grading and no formal assessment of risk of bias was attempted given the theoretical nature of the data collected. Results From 1048 citations, 22 publications met the inclusion criteria, with three more added from their references. There was evident geographical (21 were from North America/Europe) and recency (all published since 2010) bias and an exclusive patient/clinician perspective (25 of 25). The varied methodology (including ten descriptive reviews, seven opinion pieces, five surveys, two case reports, and one RCT) and evidence level (14 level V and 10 level III/IV) prevented meaningful systematic grading/meta-analysis. Publications were narratively analysed for ethical thematic content (mainly education, performance, privacy, consent, and ownership) that was then grouped by the four principles of biomedical ethics of Beauchamp and Childress, accounting for 63 distinct considerations concerning beneficence (22 of 63; 35 per cent), non-maleficence (17 of 63; 27 per cent), justice (14 of 63; 22 per cent), and autonomy (10 of 63; 16 per cent). From this, a set of proposed guidelines on the use of operative data is presented. Conclusion For a surgical video to be a truly valuable resource, its potential benefits must be more fully weighed against its potential disadvantages, so that any derived instruments have a solid ethical foundation. Universal, ethical, best-practice guidelines are needed to protect clinicians, patients, and society

Diagnosis and treatment of idiopathic premature ventricular contractions: A stepwise approach based on the site of origin

Premature ventricular contractions in the absence of structural heart disease are among the most common arrhythmias in clinical practice, with well-defined sites of origin in the right and left ventricle. In this review, starting from the electrocardiographic localization of premature ventricular contractions, we investigated the mechanisms, prevalence in the general population, diagnostic work-up, prognosis and treatment of premature ventricular contractions, according to current scientific evidence

Hepatic, renal, hematologic, and inflammatory markers in HIV-infected children on long-term suppressive antiretroviral therapy

BACKGROUND: Data on long-term toxicity of antiretroviral therapy (ART) in HIV-infected children are sparse. PENPACT-1 was an open-label trial in which HIV-infected children were assigned randomly to receive protease inhibitor (PI)- or nonnucleoside reverse-transcriptase inhibitor (NNRTI)-based ART. METHODS: We examined changes in clinical, immunologic, and inflammatory markers from baseline to year 4 in the subset of children in the PENPACT-1 study who experienced viral suppression between week 24 and year 4 of ART. Liver enzyme, creatinine, and cholesterol levels and hematologic parameters were assessed during the trial. Cystatin C, high-sensitivity C-reactive protein (hs-CRP), interleukin 6 (IL-6), d-dimer, and soluble CD14 (sCD14) were assayed from cryopreserved specimens. RESULTS: Ninety-nine children (52 on PI-based and 47 on NNRTI-based ART) met inclusion criteria. The median age at initiation of ART was 6.5 years (interquartile range [IQR], 3.7-13.4 years), and 22% were aged < 3 years at ART initiation; 56% of the PI-treated children received lopinavir/ritonavir, and 70% of NNRTI-treated children received efavirenz initially. We found no evidence of significant clinical toxicity in either group; growth, liver, kidney, and hematologic parameters either remained unchanged or improved between baseline and year 4. Total cholesterol levels increased modestly, but no difference between the groups was found. IL-6 and hs-CRP levels decreased more after 4 years in the NNRTI-based ART group. The median change in IL-6 level was -0.35 pg/ ml in the PI-based ART group and -1.0 in the NNRTI-based ART group (P = .05), and the median change in hs-CRP level was 0.25 μg/ml in the PI-based ART group and -0.95 μg/ml in the NNRTI-based ART group (P = .005). CONCLUSION: These results support the safety of prolonged ART use in HIV-infected children and suggest that suppressive NNRTI-based regimens can be associated with lower levels of systemic inflammation

Arrhythmic Risk Stratification in Arrhythmogenic Right Ventricular Cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an heritable cardiomyopathy characterized by a predominantly arrhythmic presentation. It represents the leading cause of sudden cardiac death (SCD) among athletes and poses a significant morbidity treat in the general population. As a causative treatment for ARVC is still not available, the placement of an implantable cardioverter defibrillator (ICD) represent the current cornerstone for SCD prevention in this setting. Thanks to international ARVC-dedicated efforts, significant steps have been achieved in recent years towards an individualized, patient-centered risk stratification approach. A novel risk calculator algorithm estimating the 5 year risk of arrhythmias of patients with ARVC have been introduced in clinical practice and subsequently validated. The purpose of this article is to summarize the body of evidence that has allowed the development of this tool and to discuss the best way to implement its use in the care of an individual patient

Activation of Type 1 Cannabinoid Receptor (CB1R) promotes neurogenesis in murine subventricular zone cell cultures

The endocannabinoid system has been implicated in the modulation of adult neurogenesis. Here, we describe the effect of type 1 cannabinoid receptor (CB1R) activation on self-renewal, proliferation and neuronal differentiation in mouse neonatal subventricular zone (SVZ) stem/progenitor cell cultures. Expression of CB1R was detected in SVZ-derived immature cells (Nestin-positive), neurons and astrocytes. Stimulation of the CB1R by (R)-(+)-Methanandamide (R-m-AEA) increased self-renewal of SVZ cells, as assessed by counting the number of secondary neurospheres and the number of Sox2+/+ cell pairs, an effect blocked by Notch pathway inhibition. Moreover, R-m-AEA treatment for 48 h, increased proliferation as assessed by BrdU incorporation assay, an effect mediated by activation of MAPK-ERK and AKT pathways. Surprisingly, stimulation of CB1R by R-m-AEA also promoted neuronal differentiation (without affecting glial differentiation), at 7 days, as shown by counting the number of NeuN-positive neurons in the cultures. Moreover, by monitoring intracellular calcium concentrations ([Ca2+](i)) in single cells following KCl and histamine stimuli, a method that allows the functional evaluation of neuronal differentiation, we observed an increase in neuronal-like cells. This proneurogenic effect was blocked when SVZ cells were co-incubated with R-m-AEA and the CB1R antagonist AM 251, for 7 days, thus indicating that this effect involves CB1R activation. In accordance with an effect on neuronal differentiation and maturation, R-m-AEA also increased neurite growth, as evaluated by quantifying and measuring the number of MAP2-positive processes. Taken together, these results demonstrate that CB1R activation induces proliferation, self-renewal and neuronal differentiation from mouse neonatal SVZ cell cultures.Fundacao para a Ciencia e a Tecnologia - Portugal [POCTI/SAU-NEU/68465/2006, PTDC/SAU-NEU/104415/2008, PTDC/SAU-NEU/101783/2008, POCTI/SAU-NEU/110838/2009]; Fundacao Calouste Gulbenkian [96542]; Fundacao para a Ciencia e Tecnologiainfo:eu-repo/semantics/publishedVersio