Hydrological Variability In Chilean Altiplano Lakes during the Last Millennia

Peer Reviewe

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

Accuracy of Immunodiagnostic Tests for Active Tuberculosis Using Single and Combined Results: A Multicenter TBNET-Study

The clinical application of IFN-gamma release assays (IGRAs) has recently improved the diagnosis of latent tuberculosis infection. In a multicenter study of the Tuberculosis Network European Trialsgroup (TBNET) we aimed to ascertain in routine clinical practice the accuracy of a novel assay using selected peptides encoded in the mycobacterial genomic region of difference (RD) 1 for the diagnosis of active tuberculosis in comparison with tuberculin skin test (TST), QuantiFERON-TB GOLD In-Tube (Cellestis Ltd., Carnegie, Australia) and T-SPOT.TB (Oxfordimmunotec, Abingdon, UK)

The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure

Hepatocarcinoma y trombosis portal diagnosticados por ecografía y tomografía computada en pacientes cirróticos chilenos en un hospital público, 2004 - 2011 Hepatocellular carcinoma and portal vein thrombosis diagnosed by sonography and ct scan in chilean cirrhotic patients between 2004 and 2011

No existen datos en pacientes cirróticos chilenos de prevalencia de hepatocarcinoma(CHC) y trombosis portal(TP). Objetivos: Evaluar el desarrollo de estas complicaciones y el rol que podría jugar el ultrasonido (US) como primer método de imagen en su aproximación diagnóstica. Material y métodos: Estudio de cohorte en pacientes diagnosticados mediante US o TC de cirrosis entre 2004 y 2008. Se evaluaron datos demográficos, clínicos, y su evolución hasta 2011, realizando revisión retrospectiva de sus estudios imagenológicos. Se investigó si presentaron HCC y/o TP que fueran detectados mediante US/TC. Resultados: Se incluyeron 211 pacientes, con un promedio de 62,6 años. En el 10,4% se diagnosticó HCC y en el 4,3% TP. El 33% de TP ocurrieron asociadas a CHC y determinaron peor sobrevida. El US fue sospechoso en un porcentaje significativo de los casos, motivando la realización de TC confirmatoria. Conclusiones: El US aparece como una herramienta útil para la detección de complicaciones de cirrosis.There is no available data on prevalence of hepatocellular carcinoma (HCC) and portal thrombosis (PT) in Chilean cirrhotic patients. Objectives: To evaluate the development of these entities and the role ultrasound (US) may play as the imaging method of choice in their diagnostic approach. Material and methods: A cohort study of patients with diagnosis of cirrhosis by US or CT scans between 2004 and 2008. We evaluated both demographic and clinical records, along with disease development until 2011, by performing a retrospective review of their imaging findings. We investigated whether patients presented HCC and / or PT as detected by US / CT studies. Results: Two hundred and eleven (211) patients with an average age of 62.6 years were included. HCC was diagnosed in 10.4% of cases, whilst PT was observed in 4.3% of patients. A 33% of PT occurred in association with HCC and exhibited worse survival rates. Ultrasonographic studies yielded suspicious results in a significant percentage of cases, thus CT scans were performed to confirm the diagnosis. Conclusions: Ultrasound examination appears to be a useful tool for detecting complications of cirrhosis

PLEISTOCENE HUMAN OCCUPATION IN THE ATACAMA DESERT: FIRST RESULTS FROM THE APPLICATION OF AN INTERDISCIPLINARY PREDICTIVE RESEARCH MODEL

International audienceIn South America. evidence of human occupation dates back to 14,600 calibrated years BP (14.6 ka). Yet, important areas such as the Atacama Desert, between latitude 17 degrees to 21 degrees S (northern Atacama), lack occupations older than 11.5 ka. Current hyperarid conditions in the Atacama have dissuaded many researchers from considering this region as a possible territory for Pleistocene-Holocene peoples. Paleoecological data, however, have suggested increased availability of water along the western slope of the Andes from 17.5-9.5 ka. Thus, we systematically searched for rodent middens and paleowetlands in the large canyons of the Andean Precordillera as well as the interfluves (1,000-3,000 masl). As a result, we identified specific habitats favorable for early human settling. This interdisciplinary and predictive methodological model, summarized in this pope!; allowed us to identify several sites. Among these, Quebrada Mani 12 is the first Pleistocene-Holocene human occupation (similar to 11.9 a 12.7 ka) known from the northern Atacama

Late pleistocene fuel management and human colonization of the atacama desert, northern Chile

International audienceHunter-gatherers collected and used various woody species depending on the landscape, availability of plant communities, and sociocultural considerations. With extensive paleo-wetlands and groundwater-fed oases, the Atacama Desert was interspersed with riparian woodlands that provided vital resources (fuel, water, and game) at the end of the Pleistocene in areas such as the Pampa del Tamarugal (PdT) basin. We use anthracological analyses to determine the fuel management strategies of hunter-gatherer societies in this hyperarid environment and explore whether the “Principle of Least Effort” applies. First, we present the combustion qualities and characteristics of woody taxa from the Atacama and analyze possible exploitation strategies. Second, we use anthracological analyses from Quebrada Maní 12 (QM12), a late Pleistocene archaeological site (dated from 12,750 to 11,530 cal B.P.) located in the PdT basin, to show the prevalence of two woody species that were either freshly collected or gathered (very likely on purpose) from subfossil wood. Our results suggest that fuel selection strategies were based on prior knowledge of the qualities of these woody taxa and how they burned. Thus we conclude that fuel management was part of a number of social and economic decisions that allowed for effective colonization of this region. Furthermore, we stress the need for caution when using charcoal to exclusively date archaeological sites located in desert environments