562 research outputs found

    Synegies Between Visible/Near-Infrared Imaging Spectrometry and the Thermal Infrared in an Urban Environment: An Evaluation of the Hyperspectral Infrared Imager (HYSPIRI) Mission

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    A majority of the human population lives in urban areas and as such, the quality of urban environments is becoming increasingly important to the human population. Furthermore, these areas are major sources of environmental contaminants and sinks of energy and materials. Remote sensing provides an improved understanding of urban areas and their impacts by mapping urban extent, urban composition (vegetation and impervious cover fractions), and urban radiation balance through measures of albedo, emissivity and land surface temperature (LST). Recently, the National Research Council (NRC) completed an assessment of remote sensing needs for the next decade (NRC, 2007), proposing several missions suitable for urban studies, including a visible, near-infrared and shortwave infrared (VSWIR) imaging spectrometer and a multispectral thermal infrared (TIR) instrument called the Hyperspectral Infrared Imagery (HyspIRI). In this talk, we introduce the HyspIRI mission, focusing on potential synergies between VSWIR and TIR data in an urban area. We evaluate potential synergies using an Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) and MODIS-ASTER (MASTER) image pair acquired over Santa Barbara, United States. AVIRIS data were analyzed at their native spatial resolutions (7.5m VSWIR and 15m TIR), and aggregated 60 m spatial resolution similar to HyspIRI. Surface reflectance was calculated using ACORN and a ground reflectance target to remove atmospheric and sensor artifacts. MASTER data were processed to generate estimates of spectral emissivity and LST using Modtran radiative transfer code and the ASTER Temperature Emissivity Separation algorithm. A spectral library of common urban materials, including urban vegetation, roofs and roads was assembled from combined AVIRIS and field-measured reflectance spectra. LST and emissivity were also retrieved from MASTER and reflectance/emissivity spectra for a subset of urban materials were retrieved from co-located MASTER and AVIRIS pixels. Fractions of Impervious, Soil, Green Vegetation (GV) and Non-photosynthetic Vegetation (NPV), were estimated using Multiple Endmember Spectral Mixture Analysis (MESMA) applied to AVIRIS data at 7.5, 15 and 60 m spatial scales. Surface energy parameters, including albedo, vegetation cover fraction, broadband emissivity and LST were also determined for urban and natural land-cover classes in the region. Fractions were validated using 1m digital photography

    Smoking and acute urinary retention: The Olmsted County study of urinary symptoms and health status among men

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    BACKGROUND Previous reports have suggested an inverse relationship between smoking and surgery for benign prostatic hyperplasia (BPH). We hypothesized that acute urinary retention (AUR), an adverse outcome of this disease and indication for surgical treatment, may be related to smoking. METHODS Study subjects were randomly selected from Olmsted County men aged 40–79 identified through the Rochester Epidemiology Project. Of the 3,854 eligible men, 2,089 (54%) completed a questionnaire that included the American Urological Association Symptom Score and assessed smoking status. Community medical records were examined for occurrence of AUR with documented catheterization in the subsequent 10 years and occurrence of BPH surgery. Proportional hazard models were used to assess the relationship between baseline smoking status and subsequent retention. RESULTS In the 18,307 person-years of follow-up, 114 men had AUR. When compared to 727 never-smokers, there was a trend among the 336 current smokers to be at lower risk (Relative risk (RR) = 0.62, 95% Confidence Interval (CI) = 0.33, 1.18) whereas the 1,026 former smokers were at similar risk to non-smokers (RR = 1.0, 95%CI = 0.67, 1.46). Among men with moderate-severe symptoms at baseline, current smokers were at lower risk of retention compared to non-smokers (RR = 0.65, 95%CI = 0.22, 1.91) but the association approached the null among those with none-mild symptoms (RR = 0.91, 95% CI = 0.40, 2.06). CONCLUSIONS Community-dwelling men who currently smoke may be at a modestly reduced risk of AUR. The magnitude of this association is sufficiently small that it seems unlikely that this explains a sizable proportion of the inverse association between smoking and surgically treated BPH. Prostate 69: 699–705, 2009. © 2009 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62129/1/20914_ftp.pd

    Selection of HyspIRI optimal band positions for the earth compositional mapping using HyTES data

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    The National Aeronautics and Space Administration (NASA) has proposed the launch of a new space-borne sensor called HyspIRI (Hyperspectral and Infrared Imager) which will cover the spectral range from 0.4–12 μm. Two instruments will be mounted on HyspIRI platform: 1) a hyperspectral instrument which can sense earth surface between 0.4 and 2.5 μm at 10 nm intervals and 2) a multispectral infrared sensor will acquire images between 3 and 12 μm in eight spectral bands (one in Mid infrared (MIR) and seven in Thermal Infrared (TIR)). The TIR spectral wavebands will be positioned based on their importance in various applications. This study aimed to identify HyspIRI optimal TIR wavebands position for earth compositional mapping. A Genetic Algorithm coupled with the Spectral Angle Mapper (GA-SAM) was used as a spectral bands selector. High dimensional HyTES (Hyperspectral Thermal Emission Spectrometer) emissivity spectra comprised of 202 spectral bands of Cuprite and Death Valley regions were used to select meaningful subsets of bands for earth compositional mapping. The GA-SAM was trained for fifteen mineral classes and the algorithms were run iteratively 50 times. High calibration (> 95%) and validation (> 90%) accuracies were achieved with a limited number (seven) of spectral bands selected by GA-SAM. The knowledge of important band positions will help the scientists of the HyspIRI group to place spectral bands in regions where accuracies of earth compositional mapping can be enhanced

    Ebola exposure, illness experience, and Ebola antibody prevalence in international responders to the West African Ebola epidemic 2014-2016: A cross-sectional study.

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    BACKGROUND: Healthcare and other front-line workers are at particular risk of infection with Ebola virus (EBOV). Despite the large-scale deployment of international responders, few cases of Ebola virus disease have been diagnosed in this group. Since asymptomatic or pauci-symptomatic infection has been described, it is plausible that infections have occurred in healthcare workers but have escaped being diagnosed. We aimed to assess the prevalence of asymptomatic or pauci-symptomatic infection, and of exposure events, among returned responders to the West African Ebola epidemic 2014-2016. METHODS AND FINDINGS: We used snowball sampling to identify responders who had returned to the UK or Ireland, and used an online consent and questionnaire to determine their exposure to EBOV and their experience of illness. Oral fluid collection devices were sent and returned by post, and samples were tested using an EBOV IgG capture assay that detects IgG to Ebola glycoprotein. Blood was collected from returnees with reactive samples for further testing. Unexposed UK controls were also recruited. In all, 300 individuals consented, of whom 268 (89.3%) returned an oral fluid sample (OFS). The majority had worked in Sierra Leone in clinical, laboratory, research, and other roles. Fifty-three UK controls consented and provided samples using the same method. Of the returnees, 47 (17.5%) reported that they had had a possible EBOV exposure. Based on their free-text descriptions, using a published risk assessment method, we classified 43 (16%) as having had incidents with risk of Ebola transmission, including five intermediate-risk and one high-risk exposure. Of the returnees, 57 (21%) reported a febrile or diarrhoeal illness in West Africa or within 1 mo of return, of whom 40 (70%) were not tested at the time for EBOV infection. Of the 268 OFSs, 266 were unreactive. Two returnees, who did not experience an illness in West Africa or on return, had OFSs that were reactive on the EBOV IgG capture assay, with similar results on plasma. One individual had no further positive test results; the other had a positive result on a double-antigen bridging assay but not on a competitive assay or on an indirect EBOV IgG ELISA. All 53 controls had non-reactive OFSs. While the participants were not a random sample of returnees, the number participating was high. CONCLUSIONS: This is the first study, to our knowledge, of the prevalence of EBOV infection in international responders. More than 99% had clear negative results. Sera from two individuals had discordant results on the different assays; both were negative on the competitive assay, suggesting that prior infection was unlikely. The finding that a significant proportion experienced "near miss" exposure events, and that most of those who experienced symptoms did not get tested for EBOV at the time, suggests a need to review and standardise protocols for the management of possible exposure to EBOV, and for the management of illness, across organisations that deploy staff to outbreaks

    How to ask sensitive questions in conservation: A review of specialized questioning techniques

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    Tools for social research are critical for developing an understanding of conservation problems and assessing the feasibility of conservation actions. Social surveys are an essential tool frequently applied in conservation to assess both people’s behaviour and to understand its drivers. However, little attention has been given to the weaknesses and strengths of different survey tools. When topics of conservation concern are illegal or otherwise sensitive, data collected using direct questions are likely to be affected by non-response and social desirability biases, reducing their validity. These sources of bias associated with using direct questions on sensitive topics have long been recognised in the social sciences but have been poorly considered in conservation and natural resource management. We reviewed specialized questioning techniques developed in a number of disciplines specifically for investigating sensitive topics. These methods ensure respondent anonymity, increase willingness to answer, and critically, make it impossible to directly link incriminating data to an individual. We describe each method and report their main characteristics, such as data requirements, possible data outputs, availability of evidence that they can be adapted for use in illiterate communities, and summarize their main advantages and disadvantages. Recommendations for their application in conservation are given. We suggest that the conservation toolbox should be expanded by incorporating specialized questioning techniques, developed specifically to increase response accuracy. By considering the limitations of each survey technique, we will ultimately contribute to more effective evaluations of conservation interventions and more robust policy decisions

    Spin state behavior of iron(II)/dipyrazolylpyridine complexes. New insights from crystallographic and solution measurements

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    The isomeric complexes [Fe(1-bpp)2]2+ and [Fe(3-bpp)2]2+ (1-bpp=2,6-di[pyrazol-1-yl]pyridine; 3-bpp=2,6-di[1H-pyrazol-3-yl]pyridine) and their derivatives are some of the most widely investigated complexes in spin-crossover research. This article addresses two unique aspects of their spin-state chemistry. First, is an unusual structural distortion in the high-spin form that can inhibit spin-crossover in the solid state. A new analysis of these structures using continuous shape measures has explained this distortion in terms of its effect on the metal coordination geometry, and has shown that the most highly distorted structures are a consequence of crystal packing effects. Second, solution studies have quantified the influence of second-sphere hydrogen bonding on spin-crossover in [Fe(3-bpp)2]2+, which responds to the presence of different anions and solvents (especially water). Previously unpublished data from the unsymmetric isomer [Fe(1,3-bpp)2]2+ (1,3-bpp=2-[pyrazol-1-yl]-6-[1H-pyrazol-3-yl]pyridine) are presented for comparison. Modifications to the structure of [Fe(3-bpp)2]2+, intended to augment these supramolecular effects, are also described

    The relationship between physical and wellness measures and injury in amateur rugby union players

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    peer-reviewedObjectives To investigate factors associated with injury in amateur male and female rugby union players. Design A prospective cohort study. Setting Amateur rugby clubs in Ireland. Participants Male (n = 113) and female (n = 24) amateur rugby union players from 5 of the top 58 amateur clubs in Ireland. Main outcome measures Pre-season testing included physical tests assessing hamstring flexibility, dorsiflexion range of movement, adductor muscle strength and foot position. Wellness questionnaires assessed sleep quality (PSQI), coping skills (ACSI-28) and support levels (PASS-Q). Players were monitored throughout the season for injury. Results The time-loss match injury incidence rate was 48.2/1000 player hours for males and 45.2/1000 player hours for females. Two risk profiles emerged involving; ‘age + navicular drop + training pitch surface’ (53%) and ‘age + navicular drop + groin strength’ (16%). An inverse relationship between groin strength and groin injury was found for the ‘backs’ players (−0.307, p < 0.05). Using the PSQI, 61% of players had poor sleep quality, however no relationship between the wellness questionnaires and injury was found. Conclusion Two injury risk profiles emerged, associated with subsequent injury occurrence. Using these risk profiles, individualized prevention strategies may be designed regarding deficits in groin muscle strength and identifying foot alignment.ACCEPTEDpeer-reviewe
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