2,884 research outputs found

    Myanmar Ecological Forecasting: Utilizing NASA Earth Observations to Monitor, Map, and Analyze Mangrove Forests in Myanmar for Enhanced Conservation

    Get PDF
    Mangroves supply many essential environmental amenities, such as preventing soil erosion, filtering water pollution, and protecting shorelines from harmful waves, floods, storms and winds. The Mangroves in Myanmar not only provide citizens with a food source, but they also offer firewood, charcoal, and construction materials. The depletion of mangroves is threatening more than the biodiversity however; Myanmar's fiscal livelihood is also in harm's way. Mangroves are valued at 100,000to100,000 to 277,000 per square kilometer and if managed in a sustainable fashion, can infuse constant income to the emerging Myanmarese economy. This study analyzed three coastline regions, the Ayeyarwady Delta, Rakhine and Tanintharyi, and mapped the spatial extent of mangrove forest during the dry season in 2000 and 2013. The classifications were derived from Landsat 7 Enhanced Thematic Mapper Plus (ETM+) and Landsat 8 Operation Land Imager (OLI) imagery, as well as the Terra Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) digital elevation model information. This data was atmospherically corrected, mosaicked, masked and classified in ENVI, followed by ArcGIS to perform raster calculations and create final products. Forest degradation collected from 2000 to 2013 was later used to forecast the density and health of Mangroves in the year 2030. These results were subsequently presented to project partners Dr. Peter Leimgruber and Ellen Aiken at the Smithsonian Conservation Biology Institute in Front Royal, VA. After the presentation of the project to the partners, these organizations formally passed on to the Myanmar Ministry of Environment, Conservation and Forestry for policy makers and forest managers to utilize in order to protect the Myanmar mangrove ecosystem while sustaining a healthy economy

    Topological edge states in periodically-driven trapped-ion chains

    Get PDF
    Topological insulating phases are primarily associated with condensed-matter systems, which typically feature short-range interactions. Nevertheless, many realizations of quantum matter can exhibit long-range interactions, and it is still largely unknown the effect that these latter may exert upon the topological phases. In this Letter, we investigate the Su-Schrieffer-Heeger topological insulator in the presence of long-range interactions. We show that this model can be readily realized in quantum simulators with trapped ions by means of a periodic driving. Our results indicate that the localization of the associated edge states is enhanced by the long-range interactions, and that the localized components survive within the ground state of the model. These effects could be easily confirmed in current state-of-the-art experimental implementations

    Single-Molecule Fluorophores as Environmental Nanoprobes

    Get PDF
    The DCDHF dyes are under development as a promising new class of single-molecule fluorophores. The utility of these fluorophores is derived from a range of attributes including their synthetic accessibility, structural versatility and photostability, all permitting a range of practical labelling applications. Their polarity- and viscosity-dependent emission, required for their application as local environment nanoprobes, is of particular interest. A wide range of DCDHF chromophores with different p-systems have been prepared for control of absorption and emission characteristics. Structure-function analysis has been performed in conjunction with theoretical evaluations of these chromophores.The DCDHF dyes are under development as a promising new class of single-molecule fluorophores. The utility of these fluorophores is derived from a range of attributes including their synthetic accessibility, structural versatility and photostability, all permitting a range of practical labelling applications. Their polarity- and viscosity-dependent emission, required for their application as local environment nanoprobes, is of particular interest. A wide range of DCDHF chromophores with different p-systems have been prepared for control of absorption and emission characteristics. Structure-function analysis has been performed in conjunction with theoretical evaluations of these chromophores

    Enhanced normalisation of CD4/CD8 ratio with earlier antiretroviral therapy at Primary HIV Infection.

    Get PDF
    BACKGROUND: Total CD4 T-cell counts predict HIV disease progression, but do not necessarily reflect normalization of immune function. CD4/CD8 ratio is a marker of immune dysfunction, a prognostic indicator for non-AIDS mortality, and reflects viral reservoir size. Despite ART, recovery of CD4/CD8 ratio in chronic HIV infection is incomplete; we hypothesize enhanced CD4/CD8 ratio recovery with earlier treatment initiation in recently infected individuals. METHODS: CD4 count and CD4/CD8 ratio were analyzed using data from two cohorts: SPARTAC trial, and the UK HIV Seroconverters Cohort where Primary HIV infection (PHI) was defined as within 6 months from estimated date of infection. Using time-to-event methods and Cox proportional hazard models we examined the effect of CD4/CD8 ratio at seroconversion on disease progression (CD41.0). FINDINGS: Of 573 seroconverters, 482 (84%) had abnormal CD4/CD8 ratios at HIV seroconversion. Individuals with higher CD4/CD8 ratio at seroconversion were significantly less likely to reach the disease progression end point (aHR [95% CI] = 0.52 [0.32, 0.82], p=0.005). The longer the interval between seroconversion and ART initiation (HR [95% CI] =0.98 per month increase [0.97, 0.99], p<0.001) the less likely CD4/CD8 ratio normalization. ART initiation within 6 months from seroconversion was significantly more likely to normalize (HR [95% CI] =2.47 [1.67, 3.67], p<0.001) than those initiating later. INTERPRETATION: The majority of individuals presenting in PHI have abnormal CD4/CD8 ratios. The sooner ART is initiated in PHI the greater the probability of achieving normal CD4/CD8 ratio

    Hamiltonian Dynamics and the Phase Transition of the XY Model

    Full text link
    A Hamiltonian dynamics is defined for the XY model by adding a kinetic energy term. Thermodynamical properties (total energy, magnetization, vorticity) derived from microcanonical simulations of this model are found to be in agreement with canonical Monte-Carlo results in the explored temperature region. The behavior of the magnetization and the energy as functions of the temperature are thoroughly investigated, taking into account finite size effects. By representing the spin field as a superposition of random phased waves, we derive a nonlinear dispersion relation whose solutions allow the computation of thermodynamical quantities, which agree quantitatively with those obtained in numerical experiments, up to temperatures close to the transition. At low temperatures the propagation of phonons is the dominant phenomenon, while above the phase transition the system splits into ordered domains separated by interfaces populated by topological defects. In the high temperature phase, spins rotate, and an analogy with an Ising-like system can be established, leading to a theoretical prediction of the critical temperature TKT0.855T_{KT}\approx 0.855.Comment: 10 figures, Revte

    Evolution of the Bianchi I, the Bianchi III and the Kantowski-Sachs Universe: Isotropization and Inflation

    Get PDF
    We study the Einstein-Klein-Gordon equations for a convex positive potential in a Bianchi I, a Bianchi III and a Kantowski-Sachs universe. After analysing the inherent properties of the system of differential equations, the study of the asymptotic behaviors of the solutions and their stability is done for an exponential potential. The results are compared with those of Burd and Barrow. In contrast with their results, we show that for the BI case isotropy can be reached without inflation and we find new critical points which lead to new exact solutions. On the other hand we recover the result of Burd and Barrow that if inflation occurs then isotropy is always reached. The numerical integration is also done and all the asymptotical behaviors are confirmed.Comment: 22 pages, 12 figures, Self-consistent Latex2e File. To be published in Phys. Rev.

    Improved Survival of Patients With Extensive Burns: Trends in Patient Characteristics and Mortality Among Burn Patients in a Tertiary Care Burn Facility, 2004–2013

    Get PDF
    Classic determinants of burn mortality are age, burn size, and the presence of inhalation injury. Our objective was to describe temporal trends in patient and burn characteristics, inpatient mortality, and the relationship between these characteristics and inpatient mortality over time. All patients aged 18 years or older and admitted with burn injury, including inhalation injury only, between 2004 and 2013 were included. Adjusted Cox proportional hazards regression models were used to estimate the relationship between admit year and inpatient mortality. A total of 5540 patients were admitted between 2004 and 2013. Significant differences in sex, race/ethnicity, burn mechanisms, TBSA, inhalation injury, and inpatient mortality were observed across calendar years. Patients admitted between 2011 and 2013 were more likely to be women, non-Hispanic Caucasian, with smaller burn size, and less likely to have an inhalation injury, in comparison with patients admitted from 2004 to 2010. After controlling for patient demographics, burn mechanisms, and differential lengths of stay, no calendar year trends in inpatient mortality were detected. However, a significant decrease in inpatient mortality was observed among patients with extensive burns (≥75% TBSA) in more recent calendar years. This large, tertiary care referral burn center has maintained low inpatient mortality rates among burn patients over the past 10 years. While observed decreases in mortality during this time are largely due to changes in patient and burn characteristics, survival among patients with extensive burns has improved

    RECOVER: An Automated Cloud-Based Decision Support System for Post-fire Rehabilitation Planning

    Get PDF
    RECOVER is a site-specific decision support system that automatically brings together in a single analysis environment the information necessary for post-fire rehabilitation decision-making. After a major wildfire, law requires that the federal land management agencies certify a comprehensive plan for public safety, burned area stabilization, resource protection, and site recovery. These burned area emergency response (BAER) plans are a crucial part of our national response to wildfire disasters and depend heavily on data acquired from a variety of sources. Final plans are due within 21 days of control of a major wildfire and become the guiding document for managing the activities and budgets for all subsequent remediation efforts. There are few instances in the federal government where plans of such wide-ranging scope and importance are assembled on such short notice and translated into action more quickly. RECOVER has been designed in close collaboration with our agency partners and directly addresses their high-priority decision-making requirements. In response to a fire detection event, RECOVER uses the rapid resource allocation capabilities of cloud computing to automatically collect Earth observational data, derived decision products, and historic biophysical data so that when the fire is contained, BAER teams will have a complete and ready-to-use RECOVER dataset and GIS analysis environment customized for the target wildfire. Initial studies suggest that RECOVER can transform this information-intensive process by reducing from days to a matter of minutes the time required to assemble and deliver crucial wildfire-related data

    Household Management of Childhood Diarrhoea: A Population-based Study in Nicaragua

    Get PDF
    Diarrhoea remains an important cause of mortality and morbidity among children in Nicaragua. As the majority of diarrhoeal cases are treated at home and appropriate household management can lessen severity of diarrhoea, the objective of this study was to examine household management of childhood diarrhoea. A simple random sample of households was selected from the Health and Demographic Surveillance Site-Le\uf3n. Parents or caretakers of children below five years of age, who developed diarrhoea (n=232), were surveyed about household diarrhoea management practices in 2011. Fifty-seven percent of children received oral rehydration therapy (ORT) in the home prior to visiting any health facility. We encountered certain practices in contradiction with WHO recommendations for the management of diarrhoea in communities: 41% of children were offered protein-rich foods less frequently during diarrhoeal episodes, 20% of children were nursed less frequently or not at all during diarrhoeal episodes, and zinc supplementation was recommended at only 39% of visits with healthcare providers. Our findings provide insights for efforts to improve the household management of childhood diarrhoea in Nicaragua

    Household Management of Childhood Diarrhoea: A Population-based Study in Nicaragua

    Get PDF
    Diarrhoea remains an important cause of mortality and morbidity among children in Nicaragua. As the majority of diarrhoeal cases are treated at home and appropriate household management can lessen severity of diarrhoea, the objective of this study was to examine household management of childhood diarrhoea. A simple random sample of households was selected from the Health and Demographic Surveillance Site-León. Parents or caretakers of children below five years of age, who developed diarrhoea (n=232), were surveyed about household diarrhoea management practices in 2011. Fifty-seven percent of children received oral rehydration therapy (ORT) in the home prior to visiting any health facility. We encountered certain practices in contradiction with WHO recommendations for the management of diarrhoea in communities: 41% of children were offered protein-rich foods less frequently during diarrhoeal episodes, 20% of children were nursed less frequently or not at all during diarrhoeal episodes, and zinc supplementation was recommended at only 39% of visits with healthcare providers. Our findings provide insights for efforts to improve the household management of childhood diarrhoea in Nicaragua
    corecore