Volcanism and climate change as drivers in Holocene depositional dynamic of Laguna del Maule (Andes of central Chile – 36° S)

Late Quaternary volcanic basins are active landscapes from which detailed archives of past climate and seismic and volcanic activity can be obtained. A multidisciplinary study performed on a transect of sediment cores was used to reconstruct the depositional evolution of the high-elevation Laguna del Maule (LdM) (36∘ S, 2180 m a.s.l., Chilean Andes). The recovered 5 m composite sediment sequence includes two thick turbidite units (LT1 and LT2) and numerous tephra layers (23 ash and 6 lapilli). We produced an age model based on nine new 14C AMS dates, existing 210Pb and 137Cs data, and the Quizapú ash horizon (1932 CE). According to this age model, the relatively drier Early Holocene was followed by a phase of increased productivity during the mid-Holocene and higher lake levels after 4.0 ka cal BP. Major hydroclimate transitions occurred at ca. 11, 8.0, 4.0 and 0.5 ka cal BP. Decreased summer insolation and winter precipitation due to a southward shift in the southern westerly winds and a strengthened Pacific Subtropical High could explain Early Holocene lower lake levels. Increased biological productivity during the mid-Holocene (∼8.0 to 6.0 ka cal BP) is coeval with a warm–dry phase described for much of southern South America. Periods of higher lake productivity are synchronous to a higher frequency of volcanic events. During the Late Holocene, the tephra layers show compositional changes suggesting a transition from silica-rich to silica-poor magmas at around 4.0 ka cal BP. This transition was synchronous with increased variability of sedimentary facies and geochemical proxies, indicating higher lake levels and increased moisture at LdM after 4.0 ka cal BP, most likely caused by the inception of current El Niño–Southern Oscillation and Pacific Decadal Oscillation (ENSO–PDO) dynamics in central Chile.Postprin

Influence of Milk-Feeding Type and Genetic Risk of Developing Coeliac Disease on Intestinal Microbiota of Infants: The PROFICEL Study

Interactions between environmental factors and predisposing genes could be involved in the development of coeliac disease (CD). This study has assessed whether milk-feeding type and HLA-genotype influence the intestinal microbiota composition of infants with a family history of CD. The study included 164 healthy newborns, with at least one first-degree relative with CD, classified according to their HLA-DQ genotype by PCR-SSP DQB1 and DQA1 typing. Faecal microbiota was analysed by quantitative PCR at 7 days, and at 1 and 4 months of age. Significant interactions between milk-feeding type and HLA-DQ genotype on bacterial numbers were not detected by applying a linear mixed-model analysis for repeated measures. In the whole population, breast-feeding promoted colonization of C. leptum group, B. longum and B. breve, while formula-feeding promoted that of Bacteroides fragilis group, C. coccoides-E. rectale group, E. coli and B. lactis. Moreover, increased numbers of B. fragilis group and Staphylococcus spp., and reduced numbers of Bifidobacterium spp. and B. longum were detected in infants with increased genetic risk of developing CD. Analyses within subgroups of either breast-fed or formula-fed infants indicated that in both cases increased risk of CD was associated with lower numbers of B. longum and/or Bifidobacterium spp. In addition, in breast-fed infants the increased genetic risk of developing CD was associated with increased C. leptum group numbers, while in formula-fed infants it was associated with increased Staphylococcus and B. fragilis group numbers. Overall, milk-feeding type in conjunction with HLA-DQ genotype play a role in establishing infants' gut microbiota; moreover, breast-feeding reduced the genotype-related differences in microbiota composition, which could partly explain the protective role attributed to breast milk in this disorder

Lo glocal y el turismo. Nuevos paradigmas de interpretación.

El estudio del turismo se realiza desde múltiples escalas y enfoques, este libro aborda muchos temas que es necesario discutir desde diversas perspectivas; es el caso de la reflexión sobre la propia disciplina y sus conceptos, así como los asuntos específicos referidos al impacto territorial, los tipos de turismo, las cuestiones ambientales, el tema de la pobreza, la competitividad, las políticas públicas, el papel de las universidades, las áreas naturales protegidas, la sustentabilidad, la cultura, el desarrollo, la seguridad, todos temas centrales documentados y expuestos con originalidad y dominio del asunto. Lo multiescalar es básico para la comprensión del sistema turístico, sistema formado de procesos globales, regionales y locales. El eje de discusión del libro es lo glocal, esa interacción entre lo nacional y local con lo global

Diseño instruccional para el entorno virtual de aprendizaje: Posgrado Universidad del Zulia

The objective of the research was to describe the instructional design process applied in the Virtual Learning Environment (EVA) of the Postgraduate Division of the Eastern coast of Maracaibo lake Nucleus of the University of Zulia (LUZ-COL). The online work methodology P.A.C.I.E (Presence-Outreach-Training-Interaction-Elearning), Camacho, (2004) was applied for the instructional design of virtual classrooms, created under Moodle technology. Methodologically and functionally, the EVA was developed with design of classrooms by themes for the academic programs offered. As a conclusion, it is considered necessary to keep the standards updated for the optimal performance of the platformLa investigación tuvo como objetivo, describir el proceso de diseño instruccional aplicado en el Entorno Virtual de Aprendizaje (EVA) de la División de Postgrado del Núcleo Costa Oriental del Lago de la Universidad del Zulia (LUZ-COL). Se aplicó la metodología de trabajo online P.A.C.I.E (Presencia-Alcance-Capacitación-InteracciónElearning), Camacho, (2004) para el diseño instruccional de las aulas virtuales, creadas bajo tecnología Moodle. Metodológica y funcionalmente se desarrolló el EVA con diseño de aulas por temas para los programas académicos ofrecidos. Como conclusión se considera necesario mantener la actualización de los estándares para el rendimiento óptimo de la plataforma

ECMO as a bridge to heart transplantation: Insights into stratification by heart failure etiology

Background: Revisions to the heart allocation criteria in 2018 motivated an increased use of extracorporeal membrane oxygenation (ECMO) as a bridge to transplantation. Studies have demonstrated inferior post-transplant outcomes in patients bridged with ECMO but do not account for underlying diagnosis. Our objective was to elucidate the differential impact of ECMO on outcomes by heart failure (HF) etiology. Methods: The United Network of Organ Sharing database was queried for adults who underwent isolated heart transplantation after October 2018. Patients were stratified by ECMO utilization at the time of transplantation and then by HF etiology. After baseline statistical comparisons, survival analysis relied on Kaplan-Meier estimates and Cox proportional models. Results: A total of 13,203 patients were included, of whom 761 (5.8%) were supported with ECMO. ECMO patients were younger (48 vs 54 years, p < 0.001), less likely to have diabetes (24% vs 30%, p < 0.001), smoke cigarettes (31% vs 41%, p < 0.001), or have prior cardiac surgery (29% vs 36%, p < 0.001), more likely to require dialysis (20% vs 5%, p < 0.001), and spent fewer days on the waitlist (59 vs 190, p < 0.001). After adjustment, ECMO was associated with increased mortality (hazard ratio 1.85, p < 0.001) in the full cohort. After incorporating HF etiology, this increased mortality risk persisted in all subgroups except restrictive cardiomyopathy and congenital heart disease (CHD). Conclusions: Our findings illustrate that HF etiology is associated with differing outcomes when bridging with ECMO. ECMO patients with restrictive cardiomyopathy or CHD did not have increased mortality risk. With ECMO utilization increasing, these data are hypothesis-generating and serve as a basis for further studies

Holocene depositional evolution of Laguna del Maule (central Andes, Chile, 36° S): volcanic and paleoclimate implications

The Laguna del Maule (LdM) volcanic field is one of the most seismically and volcanically active areas in the central-southern Andes, with intense postglacial and Holocene activity. We performed a seismic survey and collected a transect of sediment cores to study the depositional evolution of the lake located in the LdM caldera. This new high-resolution centennial-scale multi-proxy record provides insight into environmental and eruptive dynamics over the last 13.0 ka BP. Up to 18 ash and 5 lapilli layers mark volcanic events, which mostly cluster in the early and late Holocene with an extensive volcanic event at ~ 4.0 ka. Sedimentary facies and geochemical indicators (TOC, C/N, Br/Ti and Fe/Mn) are used to infer higher (lower) organic productivity during early and mid-Holocene (late Holocene) associated to lower (higher) water levels and dominant anoxic (oxic) conditions at the bottom of the lake. We attribute decreased lake levels between ~ 8.0 and 5.0 ka in part to lowered winter precipitation, which is coeval with a southward shift in the Southern Westerly Winds documented in other records, and a strengthening of the Pacific Subtropical High. Higher fluctuations in lake levels after 4.0¿3.0 ka BP are indicative of increased ENSO variability. Several important global climate transitions (LIA, 4.0, 8.0 and 11 ka) are well represented in the LdM sequence showing the importance of this record for reconstructing regional paleohydrology. Finally, periods of higher lake productivity during early and mid-Holocene were synchronous with elevated frequencies of volcanic events suggesting a climatic-volcanic synergy in limnological processes.Peer Reviewe