1,069 research outputs found

    Spatio-temporal Analysis of Remote Sensing and Field Measurements for Smart Farming

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    AbstractFor the optimization of crop yield and quality, there is an ongoing development in improving crop management advice, in order to cope with the spatial variability of the growth process, caused by local variations in, amongst others, soil composition, moisture and nutrition content. To achieve this improvement, reliable information is required on the actual status of the vegetation and the expected development and yield given different management scenarios. Remote sensing observations form a valuable information source for assessing the location of suboptimal growth, but hardly ever provide the cause of the arrearage. In order to determine this cause, the observations must be combined with other observations and models and analyzed integrally.This article presents the followed approach and initial results of a pilot project Smart Farming carried out in the Dutch North East Polder. Observations and data from several sources have been collected for a number of potato parcels in 2014. The collected data includes multi-temporal satellite and UAS observations, field based soil, vegetation and yield observations, soil type maps, height maps, historic parcel and crop information and meteorological data. A data driven approach was followed to determine the presence of relations between the various observations in order to couple location and probable cause of sub-optimal crop growth and determine temporal developments in series of observations. The available data was analyzed integrally using correlation, regression and histogram analysis techniques. All resulting spatial layers are visually presented in a GIS based web service environment, so that the advisor or farmer can view the raw and derived information interactively and form his/her conclusions

    Laser light scattering (LLS) to observe plasma impact on the adhesion of micrometer-sized particles to a surface

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    Laser light scattering (LLS) method, combined with a long-distance microscope was utilized to detect micrometer-sized particles on a smooth substrate. LLS was capable to detect individual particle release, shrink, or fragmentation during exposure to a plasma or a gas jet. In-situ monitoring of hundreds of particles was carried out to investigate the effect of hydrogen plasma exposure on particle adhesion, morphology, and composition. LLS was calibrated with monodisperse melamine resin spheres with known sizes of 2.14 µm, 2.94 µm, and 5.26 µm in diameter. The lowest achievable noise level of approximately 3% was demonstrated for counting 5.26 µm spherical melamine particles. The accuracy for melamine particle size measurements ranged from 50% for 2.14 µm particles to 10% for 5.26 µm particles. This scatter was taken as the imprecision of the method. Size distribution for polydisperse particles with known refractive index was obtained by interpolating to an effective scattering cross-section of a sphere using Mie theory. While the Abbe diffraction limit was about 2 µm in our system, the detection limit for Si particles in LLS according to Mie approximation was assessed to about 3 µm, given the limitations of the laser flux, microscope resolution, camera noise, and particle composition. Additionally, the gradual changes in forward scattering cross-sections for Si particles during the exposure to the hydrogen plasma were consistent with Si etching reported in the literature.</p

    Reported versus measured body weight and height of 4-year-old children and the prevalence of overweight

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    Background: In adults, body weight tends to be underestimated when based on self-reported data. Whether this discrepancy between measured and reported data exists in healthy young children is unclear. We studied whether parental reported body weight and height of 4-year-old children corresponded with measured body weight and height. In addition, we studied the determinants and the consequences of differences between reported and measured data. Methods: Data on body weight and height of 864 4-year-old Dutch children born in 1996/1997 enrolled in the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) birth cohort study were collected via a questionnaire and a medical examination. Overweight was defined according to standard international age and gender specific definitions. Results: Mean differences between measured and reported body weight, height, and body mass index (BMI) were small. Parents of children with a low BMI tended to over report body weight while parents of children with a high BMI tended to underreport body weight. Whereas 9.5% of the children were overweight according to reported BMI, the prevalence of overweight was 13.4% based on measured BMI. Over 45% of the overweight children according to measured BMI were missed when reported BMI was used. Conclusion: These findings suggest that overweight prevalence rates in children are underestimated when based on reported weight and height

    Zoonotic Diseases Report 2014

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    De Staat van zoönosen geeft jaarlijks een overzicht van infectieziekten die overgaan van dier op mens, de zogenoemde zoönosen. Het gaat om de mate waarin meldingsplichtige zoönosen voorkomen en de ontwikkelingen daarvan op de lange termijn. Hierbij betreft het zowel het aantal ziektegevallen bij mensen als het voorkomen van deze ziekteverwekkers bij dieren. Ook worden elk jaar opmerkelijke voorvallen uitgelicht en wordt een thema behandeld. Voor de meeste zoönosen zijn in 2014 geen uitgesproken veranderingen waargenomen. Wel is het aantal mensen met leptospirose (waarvan de bekendste vorm de ziekte van Weil is) aanmerkelijk hoger dan het vorige jaar, van gemiddeld 30 gevallen in de afgelopen jaren naar 97 in 2014. Ook steeg het aantal Hantavirusinfecties (van gemiddeld 13 in de voorgaande jaren naar 36 in 2014). UItgelicht Een opmerkelijke gebeurtenis in 2014 is dat twee patiënten in een ziekenhuis zijn opgenomen met een ernstige longontsteking na een infectie met Chlamydia caviae. Beide patiënten bleken thuis cavia's te houden die een luchtweginfectie hadden doorgemaakt. Verder was er sinds 2003 weer een uitbraak van vogelgriep bij pluimveebedrijven veroorzaakt door een hoogpathogeen virus. Hierbij zijn vier van de vijf besmette bedrijven onafhankelijk van elkaar besmet geraakt. Het virus was vermoedelijk afkomstig van trekkende watervogels. Het is onbekend of dit virustype overdraagbaar is op de mens; wereldwijd zijn daar geen gevallen van bekend. Vogels Het thema van dit jaar is 'Onze gevleugelde vrienden' en gaat over zoönosen die via vogels kunnen worden overgebracht, zoals de papegaaienziekte. Hierbij wordt onder andere beschreven op welke vliegroutes van trekvogels gezamenlijke broed- en voederplaatsen liggen waar ze elkaar kunnen treffen en zoönoseverwekkers aan elkaar zouden kunnen overdragen.The Zoonotic Diseases Report provides an annual overview of infectious diseases transmitted from animals to humans, so-called zoonotic diseases or zoonoses. It focuses on the degree to which notifiable zoonoses occur and how they develop over the long term. Specifically, this concerns both the number of human cases and the occurrence of these pathogens in animals. Noteworthy incidents of zoonoses are also highlighted each year and a particular theme is discussed. For most zoonoses, no pronounced changes were observed in 2014. Nonetheless, the number of people with leptospirosis (of which the most well-known form is Weil's disease) was considerably higher than in the previous year, rising from an average of 30 cases in recent years to 97 cases in 2014. The number of Hantavirus infections also rose (from an average of 13 cases in the previous years to 36 cases in 2014). A closer look A notable event in 2014 is the admission of two patients to hospital with serious lung infections after being infected with Chlamydia caviae. Both patients kept guinea pigs at home that suffered from respiratory infections. There was also the first outbreak of highly pathogenic avian influenza since 2003 affecting five poultry farms. Four of the five farms became contaminated independently of each other. It is thought that the virus was transmitted from waterfowls. It is not known whether the particular virus strain can be transmitted to humans; worldwide no cases of such transmission have been reported. Birds This year's theme is 'Our winged friends'. It focuses on zoonoses that can be transmitted by birds, such as psittacosis (parrot fever). The migratory routes that coincide with shared breeding and feeding locations where migratory birds can come into contact with one another and thereby possibly transmit zoonotic pathogens to each other are also described.NVW
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