Changing diets over time: knock-on effects of marine megafauna overexploitation on their competitors in the South-Western Atlantic Ocean

This study compares the δ15N values and the trophic position of two seabird species throughout the late Holocene in three regions in the southwestern Atlantic Ocean to assess the hypothesis that the decimation of megafauna led to changes in the trophic position of mesopredators. Modern and ancient mollusk shells were also analyzed to account for changes in the isotopic baseline through time. Results revealed that modern Magellanic penguins have higher δ15N values than their ancient conspecifics in the three regions, after controlling for changes in the isotopic baseline. This was also true for modern Imperial shags compared with ancient unidentified cormorants/shags from the two areas where ancient specimens were recovered (southern Patagonia and the Beagle Channel). Such temporal variability might be caused by three non-mutually exclusive processes: decreased availability of pelagic squat lobster resulting from decreasing primary productivity through the late Holocene, increased availability of small fishes resulting from the sequential depletion of other piscivores (South American fur seal and sea lion and Argentine hake) since the late eighteenth century, and modification of the migratory patterns of Magellanic penguins. Although disentangling the relative contribution of all those processes is impossible at this time, the results reported here demonstrate that the ecology of Magellanic penguins and Imperial shags has undergone major changes since the late Holocene.Fil: Bas, Maria. Universidad de Barcelona; EspañaFil: Tivoli, Angelica Montserrat. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Briz Godino, Ivan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. University of York; Reino UnidoFil: Salemme, Monica Cira. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Santiago, Fernando Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Belardi, Juan Bautista. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Borella, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; ArgentinaFil: Vales, Damián Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Crespo, Enrique Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Cardona, Luis. Universidad de Barcelona; Españ

Convalescent plasma treatment for patients of 80 years and older with COVID-19 pneumonia

Background: Older patients, frequently with multiple comorbidities, have a high mortality from COVID-19 infection. Convalescent plasma (CP) is a therapeutic option for these patients. Our objective is to retrospectively evaluate the efficacy and adverse events of CP treatment in this population group. Methods: Forty one patients over 80 years old with COVID-19 pneumonia received CP added to standard treatment, 51.2% with high anti-SARS-CoV-2 IgG titers and 48.8% with low titers. Median time between the onset of symptoms and the infusion of plasma was 7 days (IQR 4-10). A similar group of 82 patients who received only standard treatment, during a period in which CP was not available, were selected as a control group. Results: In-hospital mortality was 26.8% for controls and 14.6% for CP patients (P = 0.131) and ICU admission was 8.5% for controls and 4.9% for CP patients (P = 0.467). Mortality tended to be lower in the high-titer group (9.5%) than in the low-titer group (20%), and in patients transfused within the first 7 days of symptom onset (10%) than in patients transfused later (19.1%), although the differences were not statistically significant (P = 0.307 and P = 0.355 respectively). There was no difference in the length of hospitalization. No significant adverse events were associated with CP treatment. Conclusions: Convalescent plasma treatment in patients over 80 years old with COVID-19 pneumonia was well tolerated but did not present a statistically significant difference in hospital mortality, ICU admission, or length of hospitalization. The results should be interpreted with caution as only half the patients received high-titer CP and the small number of patients included in the study limits the statistical power to detect significant differences

Las unidades del discurso oral. La propuesta Val.Es.Co. de segmentación de la conversación (coloquial)

El presente artículo resume y examina críticamente la propuesta de segmentación del discurso realizada en Briz y Grupo Val.Es.Co (2003). El modelo Val.Es.Co. consta de ocho unidades (discurso, diálogo, intercambio/ alternancia de turnos, intervención/turno, acto y subacto), tres órdenes (social, estructural e informativo) y cuatro posiciones (inicial, media, final e independiente); se caracteriza, además, por ser jerárquico y recursivo. La aplicación del modelo Val.Es.Co. permite la segmentación de una conversación coloquial sin residuos, así como un adecuado tratamiento de diversos fenómenos conversacionales (actos truncados, solapamientos, elementos suprasegmentales o marcadores discursivos)This paper summarizes and critically reviews the model of discourse segmentation made by Briz and Grupo Val.Es.Co (2003). This model is made up of eight units (discourse, dialogue, exchange/ turn taking, intervention/turn, act and subact), three orders (social, structural and informative) and four positions (initial, medial, final and independent). The Val.Es.Co model is also hyerarchical and recursive. By applying the Val.Es.Co model, a conversation can be divided into parts and subparts without any element remaining unanalyzed. Also, some specific features occurring in conversations such as false starts, overlappings, the segmentation value of prosodic features or discourse markers, can be successfully analyze

Provirus reactivation is impaired in HIV-1 infected individuals on treatment with dasatinib and antiretroviral therapy

The latent viral reservoir formed by HIV-1, mainly in CD4 + T cells, is responsible for the failure of antiretroviral therapy (ART) to achieve a complete elimination of the virus in infected individuals. We previously determined that CD4 + T cells from individuals with chronic myeloid leukemia (CML) on treatment with dasatinib are resistant to HIV-1 infection ex vivo. The main mechanism for this antiviral effect is the preservation of SAMHD1 activity. In this study, we aimed to evaluate the impact of dasatinib on the viral reservoir of HIV-infected individuals with CML who were on simultaneous treatment with ART and dasatinib. Due to the low estimated incidence of HIV-1 infection and CML (1:65,000), three male individuals were recruited in Spain and Germany. These individuals had been on treatment with standard ART and dasatinib for median 1.3 years (IQR 1.3-5.3 years). Reservoir size and composition in PBMCs from these individuals was analyzed in comparison with HIV-infected individuals on triple ART regimen and undetectable viremia. The frequency of latently infected cells was reduced more than 5-fold in these individuals. The reactivation of proviruses from these cells was reduced more than 4-fold and, upon activation, SAMHD1 phosphorylation was reduced 40-fold. Plasma levels of the homeostatic cytokine IL-7 and CD4 effector subpopulations TEM and TEMRA in peripheral blood were also reduced. Therefore, treatment of HIV-infected individuals with dasatinib as adjuvant of ART could disturb the reservoir reactivation and reseeding, which might have a beneficial impact to reduce its size

Estudio del quimerismo en el trasplante alogenico de progenitores hemopoyeticos

Centro de Informacion y Documentacion Cientifica (CINDOC). C/Joaquin Costa, 22. 28002 Madrid. SPAIN / CINDOC - Centro de Informaciòn y Documentaciòn CientìficaSIGLEESSpai

Estudio del quimerismo en el trasplante alogénico de progenitores hemopoyéticos

Tesis doctoral inédita leída el 10 de Julio de 1998 en la Facultad de Medicina, Departamento de Medicina, Universidad Autónoma de Madri