2,700 research outputs found

    Remote sensing in Michigan for land resource management

    Get PDF
    The Environmental Research Institute of Michigan is conducting a program whose goal is the large-scale adoption, by both public agencies and private interests in Michigan, of NASA earth-resource survey technology as an important aid in the solution of current problems in resource management and environmental protection. During the period from June 1975 to June 1976, remote sensing techniques to aid Michigan government agencies were used to achieve the following major results: (1) supply justification for public acquisition of land to establish the St. John's Marshland Recreation Area; (2) recommend economical and effective methods for performing a statewide wetlands survey; (3) assist in the enforcement of state laws relating to sand and gravel mining, soil erosion and sedimentation, and shorelands protection; (4) accomplish a variety of regional resource management actions in the East Central Michigan Planning and Development Region. Other tasks on which remote sensing technology was used include industrial and school site selection, ice detachment in the Soo Harbor, grave detection, and data presentation for wastewater management programs

    Anemia Offers Stronger Protection Than Sickle Cell Trait Against the Erythrocytic Stage of Falciparum Malaria and This Protection Is Reversed by Iron Supplementation.

    Get PDF
    BACKGROUND: Iron deficiency causes long-term adverse consequences for children and is the most common nutritional deficiency worldwide. Observational studies suggest that iron deficiency anemia protects against Plasmodium falciparum malaria and several intervention trials have indicated that iron supplementation increases malaria risk through unknown mechanism(s). This poses a major challenge for health policy. We investigated how anemia inhibits blood stage malaria infection and how iron supplementation abrogates this protection. METHODS: This observational cohort study occurred in a malaria-endemic region where sickle-cell trait is also common. We studied fresh RBCs from anemic children (135 children; age 6-24months; hemoglobin <11g/dl) participating in an iron supplementation trial (ISRCTN registry, number ISRCTN07210906) in which they received iron (12mg/day) as part of a micronutrient powder for 84days. Children donated RBCs at baseline, Day 49, and Day 84 for use in flow cytometry-based in vitro growth and invasion assays with P. falciparum laboratory and field strains. In vitro parasite growth in subject RBCs was the primary endpoint. FINDINGS: Anemia substantially reduced the invasion and growth of both laboratory and field strains of P. falciparum in vitro (~10% growth reduction per standard deviation shift in hemoglobin). The population level impact against erythrocytic stage malaria was 15.9% from anemia compared to 3.5% for sickle-cell trait. Parasite growth was 2.4 fold higher after 49days of iron supplementation relative to baseline (p<0.001), paralleling increases in erythropoiesis. INTERPRETATION: These results confirm and quantify a plausible mechanism by which anemia protects African children against falciparum malaria, an effect that is substantially greater than the protection offered by sickle-cell trait. Iron supplementation completely reversed the observed protection and hence should be accompanied by malaria prophylaxis. Lower hemoglobin levels typically seen in populations of African descent may reflect past genetic selection by malaria. FUNDING: National Institute of Child Health and Development, Bill and Melinda Gates Foundation, UK Medical Research Council (MRC) and Department for International Development (DFID) under the MRC/DFID Concordat

    The daily cloud-to-ground lightning flash density in the contiguous united states and Finland

    Get PDF
    A method is developed to quantify thunderstorm intensity according to cloud-to-ground lightning flashes (hereafter ground flashes) determined by a lightning-location sensor network. The method is based on the ground flash density ND per thunderstorm day (ground flashes per square kilometer per thunderstorm day) calculated on 20 km × 20 km fixed squares. Because the square size roughly corresponds to the area covered by a typical thunderstorm, the flash density for one square defines a unit thunderstorm for the purposes of this study. This method is tested with ground flash data obtained from two nationwide lightning-location systems: the National Lightning Detection Network (NLDN) in the contiguous United States and the portion of the Nordic Lightning Information System (NORDLIS) in Finland. The distribution of daily ground flash density ND is computed for all of Finland and four 800 000 km2 regions in the United States (identified as western, central, eastern, and Florida). Although Finland and all four U.S. regions have median values of ND of 0.01- 0.03 flashes per square kilometer per thunderstorm day-indicating that most thunderstorms produce relatively few ground flashes regardless of geographical region-the most intense 1% of the storms (as measured by the 99th percentiles of the ND distributions within each region) show much larger differences among regions. For example, the most intense 1% of the ND distributions is 1.3 flashes per square kilometer per thunderstorm day in the central U.S. region, but only 0.2 flashes per square kilometer per thunderstorm day in Finland. The spatial distribution of the most intense 1% of the ND distributions illustrates that the most intense thunderstorm days occur in the central United States and upper Midwest, which differs from the maximaof the average annual flash density NA and the number of thunderstorm days TD, bothof which occur in Florida and along the coast of the Gulf of Mexico. This method for using ND to quantify thunderstorm intensity is applicable to any region as long as the detection efficiency of the lightning-location network is high enough or known. This method can also be employed in operational forecasting to provide a quantitative measure of the lightning intensity of thunderstorms relative to climatology. © 2011 American Meteorological Society

    Experience-driven well-being and purchase: An alternative model of memorable wine tourism experiences

    Get PDF
    Wine tourism has several distinctive features that militate against using Kim et al.'s model of memorable tourism experiences to understand its antecedents and consequences. Accordingly, this study adopts an alternative theoretical framework—the stimulus–organism–response theory—to develop an alternative model. Data were collected from visitors to a well-known vineyard in Yantai, China and structural equation modelling and multiple group analysis were used to analyse them. The results suggest that experience co-creation, sensory experience, experiential satisfaction and appealing winescape are significant and positive antecedents of a memorable wine tourism experience, while eudaimonic well-being and wine purchase intention are significant and positive outcome variables. Visit frequency was found to be a moderating variable linking the winescape to memorable wine tourism experiences. Those who travel to the region frequently form a bond with the winescape that not only contributes to their well-being but also stimulates their future intentions to purchase its wine

    The Royal Society Climate Updates: What have we learnt since the IPCC 5th Assessment Report?

    Get PDF
    Climate has a huge influence on the way we live. For example, it affects the crops we can grow and the diseases we might encounter in particular locations. It also determines the physical infrastructure we need to build to survive comfortably in the face of extremes of heat, cold, drought and flood. Human emissions of carbon dioxide and other greenhouse gases have changed the composition of the atmosphere over the last two centuries. This is expected to take Earth’s climate out of the relatively stable range that has characterised the last few thousand years, during which human society has emerged. Measurements of ice cores and sea-floor sediments show that the current concentration of carbon dioxide, at just over 400 parts per million, has not been experienced for at least three million years. This causes more of the heat from the Sun to be retained on Earth, warming the atmosphere and ocean. The global average of atmospheric temperature has so far risen by about 1˚C compared to the late 19th century, with further increases expected dependent on the trajectory of carbon dioxide emissions in the next few decades. In 2013 and 2014 the Intergovernmental Panel on Climate Change (IPCC) published its fifth assessment report (AR5) assessing the evidence about climate change and its impacts. This assessment considered data from observations and records of the past. It then assessed future changes and impacts based on various scenarios for emissions of greenhouse gases and other anthropogenic factors. In 2015, almost every nation in the world agreed (in the so-called Paris Agreement) to the challenging goal of keeping global average warming to well below 2°C above pre-industrial temperatures while pursuing efforts to limit it to 1.5°C. With the next assessment report (AR6) not due until 2022, it is timely to consider how evidence presented since the publication of AR5 affects the assessments made then. The Earth’s climate is a complex system. To understand it, and the impact that climate change will have, requires many different kinds of study. Climate science consists of theory, observation and modelling. Theory begins with well-established scientific principles, seeks to understand processes occurring over a range of spatial and temporal scales and provides the basis for models. Observation includes long time series of careful measurements, recent data from satellites, and studies of past climate using archives such as tree rings, ice cores and marine sediments. It also encompasses laboratory and field experiments designed to test and enhance understanding of processes. Computer models of the Earth climate system use theory, calibrated and validated by the observations, to calculate the result of future changes. There are nevertheless uncertainties in estimating future climate. Firstly the course of climate change is dependent on what socioeconomic, political and energy paths society takes. Secondly there remain inevitable uncertainties induced for example by variability in the interactions between different parts of the Earth system and by processes, such as cloud formation, that occur at too small a scale to incorporate precisely in global models. Assessments such as those of the IPCC describe the state of knowledge at a particular time, and also highlight areas where more research is needed. We are still exploring and improving our understanding of many of the processes within the climate system, but, on the whole, new research confirms the main ideas underpinning climate research, while refining knowledge, so as to reduce the uncertainty in the magnitude and extent of crucial impacts

    Molecular weight effects on chain pull-out fracture of reinforced polymeric interfaces

    Full text link
    Using Brownian dynamics, we simulate the fracture of polymer interfaces reinforced by diblock connector chains. We find that for short chains the interface fracture toughness depends linearly on the degree of polymerization NN of the connector chains, while for longer chains the dependence becomes N3/2N^{3/2}. Based on the geometry of initial chain configuration, we propose a scaling argument that accounts for both short and long chain limits and crossover between them.Comment: 5 pages, 3 figure

    Reverse genetics with a full-length infectious cDNA of severe acute respiratory syndrome coronavirus

    Get PDF
    A previously undescribed coronavirus (CoV) is the etiologic agent responsible for severe acute respiratory syndrome (SARS). Using a panel of contiguous cDNAs that span the entire genome, we have assembled a full-length cDNA of the SARS-CoV Urbani strain, and have rescued molecularly cloned SARS viruses (infectious clone SARS-CoV) that contained the expected marker mutations inserted into the component clones. Recombinant viruses replicated as efficiently as WT virus and both were inhibited by treatment with the cysteine proteinase inhibitor (2S,3S)-transepoxysuccinyl-l-leucylamido-3-methylbutane ethyl ester. In addition, subgenomic transcripts were initiated from the consensus sequence ACGAAC in both the WT and infectious clone SARS-CoV. Availability of a SARS-CoV full-length cDNA provides a template for manipulation of the viral genome, allowing for the rapid and rational development and testing of candidate vaccines and therapeutics against this important human pathogen
    • …
    corecore