758 research outputs found
Streamlining analysis methods for large acoustic surveys using automatic detectors with operator validation
1. Passive acoustic surveys are becoming increasingly popular as a means of surveying for cetaceans and other marine species. These surveys yield large amounts of data, the analysis of which is time consuming and can account for a substantial proportion of the survey budget. Semi-automatic processes enable the bulk of processing to be conducted automatically while allowing analyst time to be reserved for validating and correcting detections and classifications. 2. Existing modules within the Passive Acoustic Monitoring software PAMGuard were used to process a large (25.4 Terabyte) dataset collected during towed acoustic ship transits. The recently developed âMulti-Hypothesis Tracking Click Train Detectorâ and the âWhistle and Moan Detectorâ modules were used to identify occasions within the dataset at which vocalising toothed whales (odontocetes) were likely to be acoustically present. These putative detections were then reviewed by an analyst, with false positives being corrected. Target motion analysis provided a perpendicular distance to odontocete click events enabling the estimation of detection functions for both sperm whales and delphinids. Detected whistles were assigned to the lowest taxonomical level possible using the PAMGuard âWhistle Classifierâ module. 3. After an initial tuning process, this semi-automatic method required 91 hr of an analyst's time to manually review both automatic click train and whistle detections from 1,696 hr of survey data. Use of the âMulti-Hypothesis Tracking Click Train Detectorâ reduced the amount of data for the analyst to search by 74.5%, while the âWhistle and Moan Detectorâ reduced data to search by 85.9%. In total, 443 odontocete groups were detected, of which 55 were from sperm whale groups, six were from beaked whales, two were from porpoise and the remaining 380 were identified to the level of delphinid group. An effective survey strip half width of 3,277 and 699âm was estimated for sperm whales and delphinids respectively. 4. The semi-automatic workflow proved successful, reducing the amount of analyst time required to process the data, significantly reducing overall project costs. The workflow presented here makes use of existing modules within PAMGuard, a freely available and open-source software, readily accessible to acoustic analysts.Publisher PDFPeer reviewe
Effect of Longitude-Dependent Cloud Coverage on Exoplanet Visible Wavelength Reflected-Light Phase Curves
We use a planetary albedo model to investigate variations in visible wavelength phase curves of exoplanets. Thermal and cloud properties for these exoplanets are derived using one-dimensional radiative-convective and cloud simulations. The presence of clouds on these exoplanets significantly alters their planetary albedo spectra. We confirm that non-uniform cloud coverage on the dayside of tidally locked exoplanets will manifest as changes to the magnitude and shift of the phase curve. In this work, we first investigate a test case of our model using a Jupiter-like planet, at temperatures consistent to 2.0 AU insolation from a solar type star, to consider the effect of H2O clouds. We then extend our application of the model to the exoplanet Kepler-7b and consider the effect of varying cloud species, sedimentation efficiency, particle size, and cloud altitude. We show that, depending on the observational filter, the largest possible shift of the phase curve maximum will be similar to 2 degrees-10 degrees for a Jupiter-like planet, and up to similar to 30 degrees (similar to 0.08 in fractional orbital phase) for hot-Jupiter exoplanets at visible wavelengths as a function of dayside cloud distribution with a uniformly averaged thermal profile. The models presented in this work can be adapted for a variety of planetary cases at visible wavelengths to include variations in planet-star separation, gravity, metallicity, and source-observer geometry. Finally, we tailor our model for comparison with, and confirmation of, the recent optical phase-curve observations of Kepler-7b with the Kepler space telescope. The average planetary albedo can vary between 0.1 and 0.6 for the 1300 cloud scenarios that were compared to the observations. Many of these cases cannot produce a high enough albedo to match the observations. We observe that smaller particle size and increasing cloud altitude have a strong effect on increasing albedo. In particular, we show that a set of models where Kepler-7b has roughly half of its dayside covered in small-particle clouds high in the atmosphere, made of bright minerals like MgSiO3 and Mg2SiO4, provide the best fits to the observed offset and magnitude of the phase-curve, whereas Fe clouds are found to be too dark to fit the observations
ADVISORY SERVICE MARKETING PROFILES FOR SOYBEANS OVER 1995-2000
This report presents marketing profiles and loan deficiency payment/marketing loan gain profiles for the advisory services followed by the AgMAS Project for the 1995 through 2000 soybean crops. Marketing profiles are constructed by plotting the cumulative net amount priced under each program's set of recommendations throughout a crop year. Loan deficiency payment/marketing loan gain (LDP/MLG) profiles are constructed by plotting the cumulative percentage of the crop on which the LDP/MLG was claimed during the crop year. Marketing profiles provide information to evaluate the style of advisory services in several ways. The percentage of crop priced is a measure of within-crop year price risk. The higher the proportion of a crop priced, the lower the sensitivity of the farmer's position value to crop price changes. For example, when 100% of the crop is priced there is no price sensitivity, which means that changes in price do not affect the value of the farmer's position. On the other hand, when the amount priced is 0%, the value of the farmer's position will vary in the same proportion as the change in price. Marketing profiles, therefore, allow investigating the evolution of price sensitivity under each service's set of recommendations along the marketing window. Marketing profiles also provide other useful information. The number of steps in the profile lines and the location of these steps in the marketing window provide information about timing, frequency and size of recommended transactions. It is also possible to determine from the marketing profile figures how intensely a program uses options markets, since when options positions are open the profile line is irregular. In the same way, LDP/MLG profiles provide information about the size and timing of LDP/MLG claims.Marketing,
ADVISORY SERVICE MARKETING PROFILES FOR CORN OVER 1995-2000
This report presents marketing profiles and loan deficiency payment/marketing loan gain profiles for the advisory services followed by the AgMAS Project for the 1995 through 2000 corn crops. Marketing profiles are constructed by plotting the cumulative net amount priced under each program's set of recommendations throughout a crop year. Loan deficiency payment/marketing loan gain (LDP/MLG) profiles are constructed by plotting the cumulative percentage of the crop on which the LDP/MLG was claimed during the crop year. Marketing profiles provide information to evaluate the style of advisory services in several ways. The percentage of crop priced is a measure of within-crop year price risk. The higher the proportion of a crop priced, the lower the sensitivity of the farmer's position value to crop price changes. For example, when 100% of the crop is priced there is no price sensitivity, which means that changes in price do not affect the value of the farmer's position. On the other hand, when the amount priced is 0%, the value of the farmer's position will vary in the same proportion as the change in price. Marketing profiles, therefore, allow investigating the evolution of price sensitivity under each service's set of recommendations along the marketing window. Marketing profiles also provide other useful information. The number of steps in the profile lines and the location of these steps in the marketing window provide information about timing, frequency and size of recommended transactions. It is also possible to determine from the marketing profile figures how intensely a program uses options markets, since when options positions are open the profile line is irregular. In the same way, LDP/MLG profiles provide information about the size and timing of LDP/MLG claims.Marketing,
EFFECT OF LONGITUDE-DEPENDENT CLOUD COVERAGE ON EXOPLANET VISIBLE WAVELENGTH REFLECTED-LIGHT PHASE CURVES
We use a planetary albedo model to investigate variations in visible wavelength phase curves of exoplanets. Thermal and cloud properties for these exoplanets are derived using one-dimensional radiative-convective and cloud simulations. The presence of clouds on these exoplanets significantly alters their planetary albedo spectra. We confirm that non-uniform cloud coverage on the dayside of tidally locked exoplanets will manifest as changes to the magnitude and shift of the phase curve. In this work, we first investigate a test case of our model using a Jupiter-like planet, at temperatures consistent to 2.0 AU insolation from a solar type star, to consider the effect of H[subscript 2]O clouds. We then extend our application of the model to the exoplanet Kepler-7b and consider the effect of varying cloud species, sedimentation efficiency, particle size, and cloud altitude. We show that, depending on the observational filter, the largest possible shift of the phase curve maximum will be ~2°â10° for a Jupiter-like planet, and up to ~30° (~0.08 in fractional orbital phase) for hot-Jupiter exoplanets at visible wavelengths as a function of dayside cloud distribution with a uniformly averaged thermal profile. The models presented in this work can be adapted for a variety of planetary cases at visible wavelengths to include variations in planetâstar separation, gravity, metallicity, and source-observer geometry. Finally, we tailor our model for comparison with, and confirmation of, the recent optical phase-curve observations of Kepler-7b with the Kepler space telescope. The average planetary albedo can vary between 0.1 and 0.6 for the 1300 cloud scenarios that were compared to the observations. Many of these cases cannot produce a high enough albedo to match the observations. We observe that smaller particle size and increasing cloud altitude have a strong effect on increasing albedo. In particular, we show that a set of models where Kepler-7b has roughly half of its dayside covered in small-particle clouds high in the atmosphere, made of bright minerals like MgSiO[subscript 3] and Mg[subscript 2]SiO[subscript 4], provide the best fits to the observed offset and magnitude of the phase-curve, whereas Fe clouds are found to be too dark to fit the observations
Study protocol:the effectiveness and cost effectiveness of a brief behavioural intervention to promote regular self-weighing to prevent weight regain after weight loss: randomised controlled trial (The LIMIT Study)
BACKGROUND: Although obesity causes many adverse health consequences, modest weight loss reduces the incidence. There are effective interventions that help people to lose weight but weight regain is common and long term maintenance remains a critical challenge. As a high proportion of the population of most high and middle income countries are overweight, there are many people who would benefit from weight loss and its maintenance. Therefore, we need to find effective low cost scalable interventions to help people achieve this. One such intervention that has shown promise is regular self-weighing, to check progress against a target, however there is no trial that has tested this using a randomised controlled design (RCT). The aim of this RCT is to evaluate the effectiveness and cost effectiveness of a brief behavioural intervention delivered by non-specialist staff to promote regular self-weighing to prevent weight regain after intentional weight loss. METHODS: A randomised trial of 560 adults who have lost âĽ5 % of their initial body weight through a 12 week weight loss programme. The comparator group receive a weight maintenance leaflet, a diagram representing healthy diet composition, and a list of websites for weight control. The intervention group receive the same plus minimally trained telephonists will ask participants to set a weight target and encourage them to weigh themselves daily, and provide support materials such as a weight record card. The primary outcome is the difference between groups in weight change from baseline to 12 months. DISCUSSION: If effective, this study will provide public health agencies with a simple, low cost maintenance intervention that could be implemented immediately. TRIAL REGISTRATION: ISRCTN52341938 Date Registered: 31/03/201
Organization of the magnetosphere during substorms
The change in degree of organization of the magnetosphere during substorms is
investigated by analyzing various geomagnetic indices, as well as
interplanetary magnetic field z-component and solar wind flow speed. We
conclude that the magnetosphere self-organizes globally during substorms, but
neither the magnetosphere nor the solar wind become more predictable in the
course of a substorm. This conclusion is based on analysis of five hundred
substorms in the period from 2000 to 2002. A minimal dynamic-stochastic model
of the driven magnetosphere that reproduces many statistical features of
substorm indices is discussed
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