76 research outputs found

    Arctic warming amplifies climate change and its impacts

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    This ScienceBrief Review examines the evidence linking Arctic warming to the amplification of climate change impacts in Arctic, boreal and mid-latitude regions. It synthesises findings from more than 190 peer-reviewed scientific articles gathered using ScienceBrief. The evidence shows that the Arctic region has warmed at least twice as much as the global average, leading to a number of environmental consequences. The extent and thickness of sea-ice have decreased and rates of permafrost thaw have increased in recent decades. The impacts of rising mean annual temperatures have been exacerbated by an increase in heatwaves this century. These changes amplify climate change and its impacts. Permafrost thaw and wildfires are releasing greenhouse gases and amplifying climate change, while the loss of sea ice is reducing the amount of solar energy reflected by the Earth’s surface. There is ongoing debate about how changes in the Arctic energy balance influence patterns of extreme weather in the mid-latitudes

    Chronic pancreatitis: Pediatric and adult cohorts show similarities in disease progress despite different risk factors

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    Objectives: To investigate the natural history of chronic pancreatitis (CP), patients in the North American Pancreatitis Study2 (NAPS2, adults) and INternational Study group of Pediatric Pancreatitis: In search for a cuRE (INSPPIRE, pediatric) were compared. Methods: Demographics, risk factors, disease duration, management and outcomes of 224 children and 1,063 adults were compared using appropriate statistical tests for categorical and continuous variables. Results: Alcohol was a risk in 53% of adults and 1% of children (p<0.0001); tobacco in 50% of adults and 7% of children (p<0.0001). Obstructive factors were more common in children (29% vs 19% in adults, p=0.001). Genetic risk factors were found more often in children. Exocrine pancreatic insufficiency was similar (children 26% vs adult 33%, p=0.107). Diabetes was more common in adults than children (36% vs 4% respectively, p<0.0001). Median emergency room visits, hospitalizations, and missed days of work/school were similar across the cohorts. As a secondary analysis, NAPS2 subjects with childhood onset (NAPS2-CO) were compared to INSPPIRE subjects. These two cohorts were more similar than the total INSPPIRE and NAPS2 cohorts, including for genetic risk factors. The only risk factor significantly more common in the NAPS2-CO cohort compared with the INSPPIRE cohort was alcohol (9% NAPS2-CO vs 1% INSPPIRE cohorts, p=0.011). Conclusions: Despite disparity in age of onset, children and adults with CP exhibit similarity in demographics, CP treatment, and pain. Differences between groups in radiographic findings and diabetes prevalence may be related to differences in risk factors associated with disease and length of time of CP

    Analysis of noise in the NOvA near detector, An

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    2016 Spring.Includes bibliographical references.The NOvA (NuMI Off-axis νe Appearance) long-baseline neutrino experiment utilizes neutrino oscillations to gain insight into the unanswered questions in neutrino physics and further our knowledge of particle physics. The answers can only be arrived at through precise and accurate measurements of neutrino properties. To obtain these high precision results using the NOvA experiment background signals and noise must be understood and characterized. The work described is a study of noise characteristics from the electronics and photosensors used in the near detector of the NOvA experiment. A number of methods for the identification and elimination of noise in the electronics are discussed

    Crystallization at Droplet Interfaces for the Fabrication of Geometrically Programmed Synthetic Magnetosomes

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    Many organisms rely on the precise growth, assembly, and/or organization of inorganic crystals to achieve vital functions, for example, three-dimensional structural support (i.e., skeletal systems based on calcite) or environmental sensing (i.e., magnetosomes based on magnetite). Mimicking the production of the complex products observed in these biomineralization processes, synthetically, remains challenging. Herein, a method for the synthesis of artificial magnetosomes with programmable magnetic domains was developed. Specifically, precursors were compartmentalized inside different surfactant-stabilized aqueous-phase droplets suspended in oil and microfluidic technologies were implemented to control their interactions precisely. When reactive droplets were brought into contact with one another, a lipid bilayer formed, allowing transport of reagents between droplets. This process led to interface-confined magnetite growth. These polarized magnetic domains were used to manipulate the synthetic magnetosomes using external magnetic fields, thus providing a convenient method for droplet manipulation and transport. This method of producing synthetic magnetosomes provides a route toward useful materials with applications in areas such as drug delivery and microfluidics

    Measurement of the inclusive electron neutrino charged-current cross section in the NOvA near detector

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    2019 Fall.Includes bibliographical references.This thesis describes the methods used to extract the inclusive νₑ charged-current cross section in the NOνA near detector using data collected from November 2014 to February 2017, corresponding to an exposure of $8.09 x 10²⁰ protons-on-target of a primarily neutrino beam. The near detector is located at Fermilab, 800 m from the primary target. The neutrino beam peaks near 2 GeV and is able to probe a variety of different neutrino-nucleus interactions through their final-state characteristics. The flux-integrated double-differential cross section is measured with respect to the final-state electron kinematics, as well as the total cross-section as a function of neutrino energy integrated over the same phase space used for the double-differential measurement