589 research outputs found

    Spatiotemporal Distribution of Key Pelagic Microbes in a Seasonal Oxygen-Deficient Coastal Upwelling System of the Eastern South Pacific Ocean

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    Indexación: Scopus.The strong seasonal variability in physical-chemical conditions of the Eastern South Pacific Ocean creates an ideal setting to study spatiotemporal distribution of key marine microbial communities. We herein report a nearly 4-year-long time series of the variability in amoA gene counts of ammonia oxidizing archaea (AOA) and bacteria (betaproteobacteria, bAOB) by quantitative PCR, GI.1a Thaumarchaeota and MG-II Euryarchaeota by CARD-FISH, and the picoplanktonic community by flow cytometry for this area. During spring-summer, non-photosynthetic picoplankton such as MG-II Euryarchaeota and GI.1a Thaumarchaeota peaked at the surface and deeper waters, respectively. General AOA and bAOB achieved higher abundances at the oxycline mainly in summer (up to 105–104 amoA copies mL–1). Generalized additive models for location, scale, and shape (GAMLSS) indicated that season and depth account for 19–46% of variations in the abundance of the groups studied, particularly GI.1a Thaumarchaeota and AOA. The oxygen and nitrite concentration were statistically meaningful predictors for the studied groups. GAMLSS models indicate that ammonia oxidizing assemblage’s variability is coupled with ammonia, nitrite, and nitrate variations. Our results indicate that microbial abundances fluctuation is associated with upwelling variability and oxygen-deficient water conditions that shape the substrates availability and metabolic response of marine microbes, including keystone ammonia oxidizing assemblages and their ecological interactions. Overall, our results support planktonic nitrification activity and its contribution to nitrous oxide excess production in the time series off Concepción and the ecological dynamics regarding AOA and bAOB in coastal waters. © Copyright © 2020 Molina, Belmar, Levipan, Ramírez-Flandes, Anguita, Galán, Montes and Ulloa.https://www.frontiersin.org/articles/10.3389/fmars.2020.561597/ful

    Enthalpy of formation of ye’elimite and ternesite

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    Calcium sulfoaluminate clinkers containing ye’elimite (Ca4Al6O12(SO4)) and ternesite (Ca5(SiO4)2SO4) are being widely investigated as components of calcium sulfoaluminate cement clinkers. These may become low energy replacements for Portland cement. Conditional thermodynamic data for ye’elimite and ternesite (enthalpy of formation) have been determined experimentally using a combination of techniques: isothermal conduction calorimetry, X-ray powder diffraction and thermogravimetric analysis. The enthalpies of formation of ye’elimite and ternesite at 25 °C were determined to be − 8523 and − 5993 kJ mol−1, respectively

    The LBNO long-baseline oscillation sensitivities with two conventional neutrino beams at different baselines

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    The proposed Long Baseline Neutrino Observatory (LBNO) initially consists of 20\sim 20 kton liquid double phase TPC complemented by a magnetised iron calorimeter, to be installed at the Pyh\"asalmi mine, at a distance of 2300 km from CERN. The conventional neutrino beam is produced by 400 GeV protons accelerated at the SPS accelerator delivering 700 kW of power. The long baseline provides a unique opportunity to study neutrino flavour oscillations over their 1st and 2nd oscillation maxima exploring the L/EL/E behaviour, and distinguishing effects arising from δCP\delta_{CP} and matter. In this paper we show how this comprehensive physics case can be further enhanced and complemented if a neutrino beam produced at the Protvino IHEP accelerator complex, at a distance of 1160 km, and with modest power of 450 kW is aimed towards the same far detectors. We show that the coupling of two independent sub-MW conventional neutrino and antineutrino beams at different baselines from CERN and Protvino will allow to measure CP violation in the leptonic sector at a confidence level of at least 3σ3\sigma for 50\% of the true values of δCP\delta_{CP} with a 20 kton detector. With a far detector of 70 kton, the combination allows a 3σ3\sigma sensitivity for 75\% of the true values of δCP\delta_{CP} after 10 years of running. Running two independent neutrino beams, each at a power below 1 MW, is more within today's state of the art than the long-term operation of a new single high-energy multi-MW facility, which has several technical challenges and will likely require a learning curve.Comment: 21 pages, 12 figure

    Analysis of Interactions of Salmonella Type Three Secretion Mutants with 3-D Intestinal Epithelial Cells

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    The prevailing paradigm of Salmonella enteropathogenesis based on monolayers asserts that Salmonella pathogenicity island-1 Type Three Secretion System (SPI-1 T3SS) is required for bacterial invasion into intestinal epithelium. However, little is known about the role of SPI-1 in mediating gastrointestinal disease in humans. Recently, SPI-1 deficient nontyphoidal Salmonella strains were isolated from infected humans and animals, indicating that SPI-1 is not required to cause enteropathogenesis and demonstrating the need for more in vivo-like models. Here, we utilized a previously characterized 3-D organotypic model of human intestinal epithelium to elucidate the role of all characterized Salmonella enterica T3SSs. Similar to in vivo reports, the Salmonella SPI-1 T3SS was not required to invade 3-D intestinal cells. Additionally, Salmonella strains carrying single (SPI-1 or SPI-2), double (SPI-1/2) and complete T3SS knockout (SPI-1/SPI-2: flhDC) also invaded 3-D intestinal cells to wildtype levels. Invasion of wildtype and TTSS mutants was a Salmonella active process, whereas non-invasive bacterial strains, bacterial size beads, and heat-killed Salmonella did not invade 3-D cells. Wildtype and T3SS mutants did not preferentially target different cell types identified within the 3-D intestinal aggregates, including M-cells/M-like cells, enterocytes, or Paneth cells. Moreover, each T3SS was necessary for substantial intracellular bacterial replication within 3-D cells. Collectively, these results indicate that T3SSs are dispensable for Salmonella invasion into highly differentiated 3-D models of human intestinal epithelial cells, but are required for intracellular bacterial growth, paralleling in vivo infection observations and demonstrating the utility of these models in predicting in vivo-like pathogenic mechanisms

    Background discrimination with a Micromegas detector prototype and veto system for BabyIAXO

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    In this paper we present measurements performed with a Micromegas X-ray detector setup. The detector is a prototype in the context of the BabyIAXO helioscope, which is under construction to search for an emission of the hypothetical axion particle from the sun. An important component of such a helioscope is a low background X-ray detector with a high efficiency in the 1-10 keV energy range. The goal of the measurement was to study techniques for background discrimination. In addition to common techniques we used a multi-layer veto system designed to tag cosmogenic neutron background. Over an effective time of 52 days, a background level of 8.6×107counts keV1cm2s18.6 \times 10^{-7}\,\text{counts keV}^{-1}\,\text{cm}^{-2} \, \text{s}^{-1} was reached in a laboratory at above ground level. This is the lowest background level achieved at surface level. In this paper we present the experimental setup, show simulations of the neutron-induced background, and demonstrate the process to identify background signals in the data. Finally, prospects to reach lower background levels down to 107counts keV1cm2s110^{-7} \, \text{counts keV}^{-1} \, \text{cm}^{-2} \, \text{s}^{-1} will be discussed

    Eficiencia del modelo pedagógico de enseñanza de los estilos básicos de natación competitiva a niños con parálisis cerebral

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    Objective: According to many outstanding scholars, sport is essential for social adaptation and integration of people with disabilities. Therefore, it is important to research innovative models for teaching competitive swimming strokes to children with cerebral palsy. The objective of the study is to design the pedagogical model of teaching the basic competitive swimming strokes to children with cerebral palsy and to evaluate its effectiveness for mastering the front crawl swimming stroke. Material and methods: A selective research methodology was used. It involved direct data collection thanks to the survey of the participants. The results showed that the level of mastering the swimming stroke used by children who applied this designed model was objectively higher in comparison with the same indicators of training related to the traditional method. Conclusions: Drawing on the assessment of swimming stroke efficiency, we believe that the proposed pedagogical model of teaching the basic competitive swimming strokes to children with cerebral palsy is effective.Objetivo: Según muchos estudiosos destacados, el deporte es fundamental para la adaptación social y la integración de las personas con discapacidad. Por lo tanto, es importante investigar modelos innovadores para enseñar brazadas de natación competitiva a niños con parálisis cerebral. El objetivo del estudio es diseñar el modelo pedagógico de enseñanza de los estilos básicos de natación competitiva a niños con parálisis cerebral y evaluar su efectividad para dominar el estilo de natación estilo crol. Material y métodos: Se utilizó una metodología de investigación selectiva. Implicó la recopilación directa de datos gracias a la encuesta a los participantes. Los resultados mostraron que el nivel de dominio de la brazada de natación utilizado por los niños que aplicaron este modelo diseñado fue objetivamente mayor en comparación con los mismos indicadores de entrenamiento relacionados con el método tradicional. Conclusiones: Basándonos en la evaluación de la eficiencia de la brazada de natación, creemos que el modelo pedagógico propuesto de enseñar las brazadas básicas de natación competitiva a niños con parálisis cerebral es eficaz

    Cooperation, Norms, and Revolutions: A Unified Game-Theoretical Approach

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    Cooperation is of utmost importance to society as a whole, but is often challenged by individual self-interests. While game theory has studied this problem extensively, there is little work on interactions within and across groups with different preferences or beliefs. Yet, people from different social or cultural backgrounds often meet and interact. This can yield conflict, since behavior that is considered cooperative by one population might be perceived as non-cooperative from the viewpoint of another. To understand the dynamics and outcome of the competitive interactions within and between groups, we study game-dynamical replicator equations for multiple populations with incompatible interests and different power (be this due to different population sizes, material resources, social capital, or other factors). These equations allow us to address various important questions: For example, can cooperation in the prisoner's dilemma be promoted, when two interacting groups have different preferences? Under what conditions can costly punishment, or other mechanisms, foster the evolution of norms? When does cooperation fail, leading to antagonistic behavior, conflict, or even revolutions? And what incentives are needed to reach peaceful agreements between groups with conflicting interests? Our detailed quantitative analysis reveals a large variety of interesting results, which are relevant for society, law and economics, and have implications for the evolution of language and culture as well

    Monitoring β-cell survival after intrahepatic islet transplantation using dynamic exendin PET imaging: a proof-of-concept study in individuals with type 1 diabetes

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    Intrahepatic transplantation of islets of Langerhans (ITx) is a treatment option for individuals with complicated type 1 diabetes and profoundly unstable glycemic control, but its therapeutic success is hampered by deterioration of graft function over time. To improve ITx strategies, technologies to noninvasively monitor the fate and survival of transplanted islets over time are of great potential value. We used [68Ga]Ga-NODAGA-exendin-4 (68Ga-exendin) positron emission tomography (PET)/computed tomography (CT) imaging to demonstrate the feasibility of quantifying β-cell mass in intrahepatic islet grafts in 13 individuals with type 1 diabetes, nine after ITx with functional islet grafts and four control patients not treated with ITx. β-Cell function was measured by mixed-meal tolerance test. With dynamic 68Ga-exendin PET/CT images, we determined tracer accumulation in hepatic hotspots, and intrahepatic fat was assessed using MRI and spectroscopy. Quantification of hepatic hotspots showed a significantly higher uptake of 68Ga-exendin in the ITx group compared with the control group (median 0.55 [interquartile range 0.51–0.63] vs. 0.43 [0.42–0.45]). GLP-1 receptor expression was found in transplanted islets by immunohistochemistry. Intrahepatic fat was not detected in a majority of the individuals. Our study provides the first clinical evidence that radiolabeled exendin imaging can be used to monitor viable transplanted islets after intraportal ITx. Metabolic health: pathophysiological trajectories and therap

    New genetic loci implicated in fasting glucose homeostasis and their impact on type 2 diabetes risk.

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    Levels of circulating glucose are tightly regulated. To identify new loci influencing glycemic traits, we performed meta-analyses of 21 genome-wide association studies informative for fasting glucose, fasting insulin and indices of beta-cell function (HOMA-B) and insulin resistance (HOMA-IR) in up to 46,186 nondiabetic participants. Follow-up of 25 loci in up to 76,558 additional subjects identified 16 loci associated with fasting glucose and HOMA-B and two loci associated with fasting insulin and HOMA-IR. These include nine loci newly associated with fasting glucose (in or near ADCY5, MADD, ADRA2A, CRY2, FADS1, GLIS3, SLC2A2, PROX1 and C2CD4B) and one influencing fasting insulin and HOMA-IR (near IGF1). We also demonstrated association of ADCY5, PROX1, GCK, GCKR and DGKB-TMEM195 with type 2 diabetes. Within these loci, likely biological candidate genes influence signal transduction, cell proliferation, development, glucose-sensing and circadian regulation. Our results demonstrate that genetic studies of glycemic traits can identify type 2 diabetes risk loci, as well as loci containing gene variants that are associated with a modest elevation in glucose levels but are not associated with overt diabetes
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