186 research outputs found

    Dioxins in organic eggs: a review

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    Eggs contribute for about 4% to the daily dioxin intake of humans. Research among layer farms in the Netherlands and other EU countries has shown that organic eggs contain more dioxin than conventional ones and that a significant number of organic farms produce eggs with a dioxin content that exceeds the EU standard. The hens’ intake of dioxins from various sources leads to an increase in the dioxin content of organic eggs. These sources include plants, feed, soil, worms and insects, and compared with hens on conventional and free-range farms, organic hens make more use of these sources due to better access to the outdoor run. Plants appear to be relatively unimportant as a source of dioxins. Also commercial organic feed generally has very low dioxin contents, but not much is known about non-commercial feed. Consumption of worms and insects and particularly ingestion of soil are important causes of high dioxin levels in eggs. Management interventions, like a reduction of the time the hens spend outside, may decrease the dioxin levels in organic eggs but at the same time may interfere with the image of the organic production system

    Performance Comparison of Various Order Picking Methods in Different Behavioral Contexts

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    Three manual picker-to-parts order picking methods (parallel picking, zone picking, and dynamic zone picking) are employed in an experimental warehouse setup and compared in terms of productivity, quality, and job satisfaction. Participants worked in teams and were subject to either an individual- based, or a team-based incentive scheme. Furthermore, the influence of individual participants’ dominant regulatory focus (promotion or prevention) was taken into account. The outcomes show that in parallel picking an incentive system focused on individual performance is beneficial for productivity and quality compared to an incentive system focused on team performance, whereas team-based incentives are more productive in zone picking. These results were more explicitly present for participants with a dominant promotion focus. Participants with a dominant prevention focus picked more productively with team-based incentives in all picking methods. In addition to this, team-based incentives led to a relatively high quality in zone-picking, but a relatively low quality in dynamic zone picking. Our study shows that assigning the right people to the right picking task with a fitting incentive system can substantially cut wage costs without simultaneously harming productivity, quality, or job satisfaction

    Patents as a measure for eco-innovation

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    First paragraph: What is a patent? A patent is an exclusive right to exploit (make, use, sell, or import) an invention over a limited period of time (20 years from filing) within the country wherethe application is made. Patents are granted for inventions which are novel, inventive(non-obvious) and have an industrial application (useful). There are other types ofexclusive rights over intangible assets, notably copyright, design protection andtrademarks, but patents provide a broader protection that extends beyond the specificexpression of an invention to the invention itself. Due to this control over the technology,the patent holder is in a position to set a higher-than-competitive price for thecorresponding good or service, which allows recovery of innovation costs. In return, theapplicant must disclose the invention in the text of the application, which is published 18months after application (From OECD report Patents and Innovation: Trends andchallenges, 2004, p.8)

    The Impact of Massed and Spaced-Out Curriculum in Oncology Knowledge Acquisition

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    Starting in 2009, cancer has been the leading cause of death in the Netherlands. Oncology is therefore an important part of the medical curriculum in undergraduate education. It is crucial that medical students know about cancer, since doctors will encounter many cases of oncology. We have compared the influence that teaching oncology has when spread over a 3-year curriculum versus concentrated in one semester. The participants comprised 525 medical students from one medical school with comprehensive integrated curricula. Of those, 436 followed the massed curriculum, with oncology concentrated in one semester. The remaining 89 students followed a spaced-out curriculum, in which oncology was spread out over 3 years. To measure students' knowledge, we used their progress test results from 2009 to 2012. All questions about oncology were categorized and selected. Because of our unbalanced sample and missing data and to reduce the chances for a type II error, we compared the growth of oncology questions using mixed effect models. A cubic growth model with an unstructured covariance matrix fitted our data best. At the start, students in the spaced-out curriculum scored higher on oncology questions. The initial growth was faster for the spaced-out curriculum students, whereas the acceleration over time was slower compared to the massed curriculum students. At the end of the growth curve, the knowledge of the massed curriculum students increased faster. In the last test, the massed curriculum students outperformed those in the spaced-out curriculum. The way students acquired and applied their knowledge was similar in both curricula. It seems, however, that students benefitted more from massed than spaced-out education, which may be due to the comprehensive integrated teaching involved.</p

    Integrating verification, testing, and learning for cryptographic protocols

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    International audienceThe verification of cryptographic protocol specifications is an active research topic and has received much attention from the formal verification community. By contrast, the black-box testing of actual implementations of protocols, which is, arguably, as important as verification for ensuring the correct functioning of protocols in the “real†world, is little studied. We propose an approach for checking secrecy and authenticity properties not only on protocol specifications, but also on black-box implementations. The approach is compositional and integrates ideas from verification, testing, and learning. It is illustrated on the Basic Access Control protocol implemented in biometric passports

    ALMA Resolves CI Emission from the beta Pictoris Debris Disk

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    The debris disk around β\beta~Pictoris is known to contain gas. Previous ALMA observations revealed a CO belt at \sim85 au with a distinct clump, interpreted as a location of enhanced gas production. Photodissociation converts CO into C and O within \sim50 years. We resolve CI emission at 492 GHz using ALMA and study its spatial distribution. CI shows the same clump as seen for CO. This is surprising, as C is expected to quickly spread in azimuth. We derive a low C mass (between 5×1045\times10^{-4} and 3.1×1033.1\times10^{-3} M_\oplus), indicating that gas production started only recently (within \sim5000 years). No evidence is seen for an atomic accretion disk inwards of the CO belt, perhaps because the gas did not yet have time to spread radially. The fact that C and CO share the same asymmetry argues against a previously proposed scenario where the clump is due to an outward migrating planet trapping planetesimals in an resonance; nor can the observations be explained by an eccentric planetesimal belt secularly forced by a planet. Instead, we suggest that the dust and gas disks should be eccentric. Such a configuration, we further speculate, might be produced by a recent tidal disruption event. Assuming that the disrupted body has had a CO mass fraction of 10%, its total mass would be \gtrsim3 MMoonM_\mathrm{Moon}.Comment: 30 pages, 15 figures, accepted by Ap

    Metformin Preconditioning and Postconditioning to Reduce Ischemia Reperfusion Injury in an IsolatedEx VivoRat and Porcine Kidney Normothermic Machine Perfusion Model

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    Metformin may act renoprotective prior to kidney transplantation by reducing ischemia-reperfusion injury (IRI). This study examined whether metformin preconditioning and postconditioning duringex vivonormothermic machine perfusion (NMP) of rat and porcine kidneys affect IRI. In the rat study, saline or 300 mg/kg metformin was administered orally twice on the day before nephrectomy. After 15 minutes of warm ischemia, kidneys were preserved with static cold storage for 24 hours. Thereafter, 90 minutes of NMP was performed with the addition of saline or metformin (30 or 300 mg/L). In the porcine study, after 30 minutes of warm ischemia, kidneys were preserved for 3 hours with oxygenated hypothermic machine perfusion. Subsequently, increasing doses of metformin were added during 4 hours of NMP. Metformin preconditioning of rat kidneys led to decreased injury perfusate biomarkers and reduced proteinuria. Postconditioning of rat kidneys resulted, dose-dependently, in less tubular cell necrosis and vacuolation. Heat shock protein 70 expression was increased in metformin-treated porcine kidneys. In all studies, creatinine clearance was not affected. In conclusion, both metformin preconditioning and postconditioning can be done safely and improved rat and porcine kidney quality. Because the effects are minor, it is unknown which strategy might result in improved organ quality after transplantation

    High protein S activity due to C4b-binding protein deficiency in a 34-year-old Surinamese female with ischemic retinopathy

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    Key Clinical Message In this study, we present the first case of a 34-year-old Surinamese female with ischemic retinopathy and increased free protein S due to C4BP deficiency. Possibly, the low PS/C4BP complex level has increased the risk of arterial thrombosis in our patient

    A clinical decision aid for patients with suspected midfacial and mandibular fractures (the REDUCTION-I study):A prospective multicentre cohort study

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    Purpose To assess physical examination findings related to maxillofacial trauma to identify patients at risk of midfacial and mandibular fractures and then to construct a clinical decision aid to rule out the presence of midfacial and mandibular fractures in emergency department patients. Methods We performed a prospective multicentre cohort study in four hospitals in the Netherlands, including consecutive patients with maxillofacial trauma. Each patient received a standardized physical examination consisting of 15 and 14 findings for midfacial and mandibular traumas, respectively. Consequently, clinical decision aids were constructed with the focus being on ruling out the presence of midfacial and mandibular fractures, and diagnostic accuracy was calculated. Results A total of 993 consecutive patients were identified of whom 766 and 280 patients were suspected of midfacial and mandibular fractures, respectively. Midfacial fractures were diagnosed in 339 patients (44.3%), whereas mandibular fractures were observed in 66 patients (23.6%). The decision aid for midfacial trauma consisting of peri-orbital hematoma, epistaxis, ocular movement limitation, infra-orbital nerve paresthesia, palpable step-off and tooth mobility or avulsion, produced a sensitivity of 89.7 (86.0-92.5), a specificity of 42.6 (38.0-47.4), and a negative predictive value of 83.9% (78.4-88.2). The decision aid for mandibular trauma consisting of the angular compression test, axial chin pressure test, objective malocclusion, tooth mobility or avulsion and the tongue blade bite test resulted in a sensitivity of 98.5 (91.9-99.7), a specificity of 34.6 (28.5-41.2), and a negative predictive value of 98.7% (92.8-99.8). Conclusion The constructed clinical decision aids for maxillofacial trauma may aid in stratifying patients suspected for midfacial and mandibular fractures to reduce unnecessary diagnostic imaging
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