2,117 research outputs found

    Ontwikkelingen kraamhokken in Raalte gaan door

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    In Raalte wordt onderzocht in hoeverre in de gangbare varkenshouderij stro verstrekt kan worden. Tot nu toe lijkt stro verstrekken in de huidige kraamhokken van ruim 4 m2 , waarvan het merendeel van de vloer roostervloer is, niet zinvol

    Prevention and treatment of parasitic infections in organic pigs

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    Organic and free range pigs are potentially exposed to a wider range of parasites and zoonotic challenges. The livestock Subproject QLIF addresses 4 strategies to combat these challenges, and the present paper describes the initial results. Rodent control is the first strategy, and a survey concludes that Salmonella and Campylobacter infections were encountered in house mice and Norway rats, but not in other species. T. gondii antibodies could be detected in 6.4% of the blood samples taken from 235 wild small mammals. To reduce the presence of rodents around farms, the use of live-traps may be a good alternative for the use of rodenticides on organic farms. A second strategy is aimed at directing pig dunging behaviour in such a way that contact with (infected) faeces is minimised. The study showed that a rooting area resulted in a cleaner outdoor are and an extra outdoor drinker led to a cleaner area around the drinker, but to a dirtier indoor area. However, no difference in Ascaris suum infection were found. The nutritional strategy tested showed that pure inulin appeared the most effective as Oesophagostomum dentatum presence was reduced by 91%. Finally, as part of Strategy 4, a mixture of dried Thymus vulgaris, Melissa officinalis and Echinacea purpurea in a dosage of 5% in the diet showed to be preventive against a mild round-worm infection. The same mixture, however, was not effective in a lower dosage (3% in the diet) against a serious round-worm infection. Work is continuing to develop the above strategies further

    Metastatic model of HPV+ oropharyngeal squamous cell carcinoma demonstrates heterogeneity in tumor metastasis

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    Human papillomavirus induced (HPV+) cancer incidence is rapidly rising, comprising 60–80% of oropharyngeal squamous cell carcinomas (OPSCCs); while rare, recurrent/metastatic disease accounts for nearly all related deaths. An in vivo pre-clinical model for these invasive cancers is necessary for testing new therapies. We characterize an immune competent recurrent/metastatic HPV+ murine model of OPSSC which consists of four lung metastatic (MLM) cell lines isolated from an animal with HPV+ OPSCC that failed cisplatin/radiation treatment. These individual metastatic clonal cell lines were tested to verify their origin (parental transgene expression and define their physiological properties: proliferation, metastatic potential, heterogeneity and sensitivity/resistance to cisplatin and radiation. All MLMs retain expression of parental HPV16 E6 and E7 and degrade P53 yet are heterogeneous from one another and from the parental cell line as defined by Illumina expression microarray. Consistent with this, reverse phase protein array defines differences in protein expression/activation between MLMs as well as the parental line. While in vitro growth rates of MLMs are slower than the parental line, in vivo growth of MLM clones is greatly enhanced. Moreover, in vivo resistance to standard therapies is dramatically increased in 3 of the 4 MLMs. Lymphatic and/or lung metastasis occurs 100% of the time in one MLM line. This recurrent/metastatic model of HPV+ OPSCC retains the characteristics evident in refractory human disease (heterogeneity, resistance to therapy, metastasis in lymph nodes/lungs) thus serving as an ideal translational system to test novel therapeutics. Moreover, this system may provide insights into the molecular mechanisms of metastasis

    Extra aandacht voor de jongste zeugen in groepshuisvesting

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    Zeugen die in de eerste dracht met oudere zeugen in één groep gehouden worden verdienen extra aandacht. Het gebruik van vaste dekgroepen, zoals vaste jeugdgroepen, is daarbij voor de jonge zeugen nog van groter belang dan voor de oudereworpszeugen

    Biologische varkenshouderij wordt vlotgetrokken

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    De prijs- en afzetgaranties die in ketens, tussenslachterijen en grootwinkelbedrijf, zijn afgesproken,geven de biologische varkenshouderijsector eenstimulans

    Zeugen in vaste dekgroepen of wisselgroepen?

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    Groepshuisvestingssystemen waarin dekgroepen tijdens de dracht niet worden gemengd zijn qua huisvesting wat duurder dan wisselgroepen, maar bieden meer kans op goede technische resultaten

    Themaboek Groepshuisvesting guste en drachtige zeugen

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    In het themaboek 'Groepshuisvesting voor guste endrachtige zeugen' zijn onderzoeksresultaten uit binnen- en buitenland en ervaringen met groepshuisvesting op proef- en praktijkbedrijven vanaf1985 gebundeld. Het boek is bedoeld voor iedereen die betrolken is bij het maken van plannen voor groepshuisvesting van zeugen

    Development of a switchless sorption compressor for the cryogenic refrigeration within the METIS instrument:Part II. Experimental demonstration

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    Due to its vibration-free feature, sorption-based refrigeration technology has been proposed for the cryogenic cooling of the Mid-infrared E-ELT Imager and Spectrograph (METIS) instrument in the European Extremely Large Telescope. Sorption compressor is the most critical component in the METIS sorption refrigerator. A switchless sorption compressor has been designed for replacing the conventional gas-gap heat switch design. In this paper, the METIS switchless sorption compressor is validated in an experimental setup with a down-scaled version. The detailed design of the sorption compressor is introduced and the experimental setup is described. Then, the experimental procedures and results are discussed, including single-cell operation, multi-cell operation, and verification of the effects of the aluminum-foil inserts, the cycle time and the heat-sink temperature on the compressor performance. Finally, the experimental result showed good agreement with the simulations, and the deviation from the simulation to the measurement is caused by the model input inaccuracy

    Development of a switchless sorption compressor for the cryogenic refrigeration within the METIS instrument:Part I. Theoretical design

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    Vibration-free cryogenic sorption refrigerator was proposed for the Mid-infrared E-ELT Imager and Spectrograph (METIS) instrument in the European Extremely Large Telescope. Sorption compressor is the most important part in the refrigerator due to its dominate size, cost and complexity. Generally, gas-gap heat switches are applied for efficiency consideration which is particularly essential for space applications. In METIS refrigerator as a terrestrial application, low input powers, however, should not be the major concern, whereas complexity and costs become more important as high refrigeration powers and thus large numbers of sorption cells are required. To reduce these, we developed an alternative switchless sorption-compressor design. This paper presents the theoretical design of the switchless METIS sorption compressors, including the comparison between the designs with and without heat switches. Based on the switchless design, critical parameters for the METIS sorption compressors are determined to enable further development such as mechanical design, fabrication and experimental demonstration
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