2,145 research outputs found

    Field Monitoring of X-Disease Leafhopper Vectors (Homoptera: Cicadellidae) and Infected Chokecherry in Michigan Peach and Cherry Orchards

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    Populations of leafhopper vectors of X-disease, a major disease problem of the Michigan peach industry, were monitored by yellow sticky board traps and sweepnet samples during 1985 and 1986. Abundance of known leafhopper vectors varied throughout the stone fruit belt of Michigan, with Paraphlepsius irroratus common in the southwest Lower Peninsula, but representing 73.1 % of all known vectors found. Other commonly found vectors included Scaphytopius acutus (22%), Colladonus clitellarius (1.5\u27k). and Norvellina seminuda (3.4%). Yellow sticky boards were the best monitoring method used. accounting for 90.3% of all vectors captured. The appearance of X-disease symptoms on chokecherry throughout the survey area indicated transmission between wild hosts was occurring in areas where X-disease is not yet a major problem to growers

    Validation of a smartphone app to map social networks of proximity

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    Social network analysis is a prominent approach to investigate interpersonal relationships. Most studies use self-report data to quantify the connections between participants and construct social networks. In recent years smartphones have been used as an alternative to map networks by assessing the proximity between participants based on Bluetooth and GPS data. While most studies have handed out specially programmed smartphones to study participants, we developed an application for iOS and Android to collect Bluetooth data from participants own smartphones. In this study, we compared the networks estimated with the smartphone app to those obtained from sociometric badges and self-report data. Participants (n=21) installed the app on their phone and wore a sociometric badge during office hours. Proximity data was collected for 4 weeks. A contingency table revealed a significant association between proximity data (rho = 0.17, p<0.0001), but the marginal odds were higher for the app (8.6%) than for the badges (1.3%), indicating that dyads were more often detected by the app. We then compared the networks that were estimated using the proximity and self-report data. All three networks were significantly correlated, although the correlation with self-reported data was lower for the app (rho = 0.25) than for badges (rho = 0.67). The scanning rates of the app varied considerably between devices and was lower on iOS than on Android. The association between the app and the badges increased when the network was estimated between participants whose app recorded more regularly. These findings suggest that the accuracy of proximity networks can be further improved by reducing missing data and restricting the interpersonal distance at which interactions are detected.Comment: 20 pages, 5 figure

    Using Bluetooth Low Energy in smartphones to map social networks

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    Social networks have an important role in an individual's health, with the propagation of health-related features through a network, and correlations between network structures and symptomatology. Using Bluetooth-enabled smartphones to measure social connectivity is an alternative to traditional paper-based data collection; however studies employing this technology have been restricted to limited sets of homogenous handsets. We investigated the feasibility of using the Bluetooth Low Energy (BLE) protocol, present on users' own smartphones, to measure social connectivity. A custom application was designed for Android and iOS handsets. The app was configured to simultaneously broadcast via BLE and perform periodic discovery scans for other nearby devices. The app was installed on two Android handsets and two iOS handsets, and each combination of devices was tested in the foreground, background and locked states. Connectivity was successfully measured in all test cases, except between two iOS devices when both were in a locked state with their screens off. As smartphones are in a locked state for the majority of a day, this severely limits the ability to measure social connectivity on users' own smartphones. It is not currently feasible to use Bluetooth Low Energy to map social networks, due to the inability of iOS devices to detect another iOS device when both are in a locked state. While the technology was successfully implemented on Android devices, this represents a smaller market share of partially or fully compatible devices.Comment: 6 pages, 1 tabl

    The Achille Lauro Incident and the Permissible Use of Force

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    Installation of insecticide-treated durable wall lining: evaluation of attachment materials and product durability under field conditions.

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    BACKGROUND: Insecticide-treated durable wall lining (DL) is a new method of vector control designed to supplement LLINs and overcome two inherent limitations of LLINs and IRS: nightly behavioural compliance and short residual activity, respectively. DL is a deltamethrin-treated polyethylene material, which when used to cover interior house walls, functions as long-lasting IRS. Because the DL concept anticipates minimal upkeep, a primary challenge is how to guarantee correct household installation and in situ longevity for several years. Field trials were undertaken on various wall surfaces in Ghana to identify a logistically feasible, durable and re-usable method for DL wall attachment and to pilot new methods for assessing DL durability. METHODS: Over fifty-five candidate attachment or fixing products, including mechanical fasteners, material anchors and adhesives, were evaluated for their ability to tolerate static loads (simulating long-term installation) and short-term heavy weights (imitating shock damage). Attachment products were also scored using qualitative logistical and feasibility criteria, including ease of preparation, grip of fixing to DL and possibility of re-use. RESULTS: The stress tests provided a standardised, reproducible and reliable system for assessing fixing effectiveness and DL durability, with 64% (14/22) of adhesives and 15% (2/13) of mechanical fasteners failing to meet the minimum requirements of attaching DL to mud walls for set time periods. For most fixings, less outward load (0.2-8.0 kg) was required to detach DL from the wall, compared to downward load (0.2-19.2 kg). Fixings were better able to grip DL onto concrete than clay surfaces. Using a plastic nail cap to increase DL attachment area greatly improved grip and outward load tolerance, more so than varying nail size, length or texture. CONCLUSIONS: Based on a series of systematic stress tests, optimized fixing products for polyethylene DL wall attachment were identified. In parallel, a detailed and adaptable method of DL household installation was developed for routine deployment in malaria endemic areas. These standardized stress tests will form the basis for comparative evaluations of new types of DL textile, which incorporate non-pyrethroid insecticides to control malaria transmitted by resistant mosquito populations

    Integration of technologies for understanding the functional relationship between reef habitat and fish growth and production

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    Functional linkage between reef habitat quality and fish growth and production has remained elusive. Most current research is focused on correlative relationships between a general habitat type and presence/absence of a species, an index of species abundance, or species diversity. Such descriptive information largely ignores how reef attributes regulate reef fish abundance (density-dependent habitat selection), trophic interactions, and physiological performance (growth and condition). To determine the functional relationship between habitat quality, fish abundance, trophic interactions, and physiological performance, we are using an experimental reef system in the northeastern Gulf of Mexico where we apply advanced sensor and biochemical technologies. Our study site controls for reef attributes (size, cavity space, and reef mosaics) and focuses on the processes that regulate gag grouper (Mycteroperca microlepis) abundance, behavior and performance (growth and condition), and the availability of their pelagic prey. We combine mobile and fixed-active (fisheries) acoustics, passive acoustics, video cameras, and advanced biochemical techniques. Fisheries acoustics quantifies the abundance of pelagic prey fishes associated with the reefs and their behavior. Passive acoustics and video allow direct observation of gag and prey fish behavior and the acoustic environment, and provide a direct visual for the interpretation of fixed fisheries acoustics measurements. New application of biochemical techniques, such as Electron Transport System (ETS) assay, allow the in situ measurement of metabolic expenditure of gag and relates this back to reef attributes, gag behavior, and prey fish availability. Here, we provide an overview of our integrated technological approach for understanding and quantifying the functional relationship between reef habitat quality and one element of production – gag grouper growth on shallow coastal reefs

    Valuation of aircraft noise by time of day: a comparison of two approaches

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    This paper reports an innovative application of stated preference techniques to derive values of aircraft noise by time of day and day of week. Revealed preference techniques cannot provide such segmentations which would clearly be of use in policy development especially relating to airport operations. Given the lack of research on this issue the work reported here is highly experimental. Two stated preference experiments were designed. The first focussed on a single time period whilst the second asked respondents to trade between time periods. Both approaches yielded results that are plausible and mutually consistent in terms of relative values by time period. We conclude that stated preference techniques are particularly useful in this context where the use of aggregated values may lead to non-optimal policy decisions

    Size and Scope of Millard County Agriculture 2019

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    Millard County borders Nevada on the west. It is in the center of the western border of Utah. Surrounding Utah counties include Juab, Sanpete, Sevier, and Beaver. The population was estimated at 12,863 in 2017. The county has a total area of 6,828 square miles, making it the third largest county in Utah. The Sevier desert covers much of the county with the Pahvant Mountains forming the eastern county boundary. This fact sheet reviews the irrigation, crop and livestock production, land ownership, growing season, and farm income of Millard County agriculture

    Size and Scope of Beaver County Agriculture 2019

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    This fact sheet profiles agriculture in Beaver County, Utah, and includes location, land ownership, growing season, crop and livestock production, farm income, and age of operator
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