213 research outputs found

    RISK FACTORS ASSOCIATED WITH CULLING AGE IN DAIRY CATTLE: APPLICATIONS OF FRAILTY MODELS

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    Culling decisions for dairy cattle are an important component of dairy herd management. To investigate risk factors for culling, farms (clusters) constitute the sampling units. Therefore, we believe that ages-at-culling may be correlated within farms. The score test on the null hypothesis of no extra-variation in survival data was not supported by age-at-culling data collected from 72 dairy farms from the province of Ontario, Canada. To correct for the intraherd correlation, three modelling approaches were used to fit the data: Population-Averaged (PA) , cluster-specific (CS), and Random Effects Models (RAEM). The modelling approaches are described and compared using the dairy cow culling data

    Protocol: Non-antibiotic, alternative approaches to the nursery phase of swine production: a scoping review

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    It is widely accepted that antibiotic use drives the development of antibiotic resistance. Hence it is important that swine production uses antibiotics in a judicious manner. In addition, the label claim for livestock antibiotic growth promoters (AGP) of importance to humans has been removed in Canada. In reality, antibiotics have contributed greatly to efficiencies in meat production and animal health. A reduction in the use of growth promoting antibiotics has ramifications for costs of meat production and animal welfare given that sick animals need to be treated, often with antibiotics. Consequences of similar AGP bans in swine production in Europe included an immediate increase in therapeutic use of antibiotics considered important for humans, particularly for nursery stage pigs in Denmark and the Netherlands. It is important to identify and advance our knowledge through the existing research of alternative approaches to antibiotic use, in the nursery stage of pig production. Scoping reviews are a relatively novel approach for synthesizing research evidence in the veterinary and livestock production research literature (Pham MT., 2014). They are useful for mapping the extent, range, and nature of existing literature on a broad topic area. In addition, scoping reviews are useful for identifying gaps in the literature and for determining the feasibility of conducting one or more systematic reviews to help answer a specific question about the effectiveness of a specific intervention in a specific population measuring a specific outcome (Arksey and O’Malley, 2005)

    The efficacy of antibiotics to prevent respiratory diseases in swine: A protocol for a systematic review

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    The treatment and prevention of infectious diseases in pigs is an important aspect of swine production worldwide. The prudent use of antimicrobials and other therapeutic drugs is a primary responsibility of swine producers and veterinarians and decisions surrounding the use of drug therapy include considerations such as cost, efficacy, and food safety. The World Health Organization has published numerous reports urging all stakeholders concerned with both food-producing animals and humans to establish recommended steps to enhance the prudent use of antimicrobials (WHO, 2015). Similarly, the Organization for Animal Health has also published recommendations and position statements regarding prudent use and risk management related to antimicrobial use in animals (OIE, 2017)

    Information retrieval for systematic reviews in food and feed topics: a narrative review

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    Introduction Systematic review methods are now being used for reviews of food production, food safety and security, plant health, and animal health and welfare. Information retrieval methods in this context have been informed by human healthcare approaches and ideally should be based on relevant research and experience. Objective This narrative review seeks to identify and summarise current research-based evidence and experience on information retrieval for systematic reviews in food and feed topics. Methods MEDLINE (Ovid), Science Citation Index (Web of Science) and ScienceDirect (http://www.sciencedirect.com/) were searched in 2012 and 2016. We also contacted topic experts and undertook citation searches. We selected and summarised studies reporting research on information retrieval, as well as published guidance and experience. Results There is little published evidence on the most efficient way to conduct searches for food and feed topics. There are few available study design search filters, and their use may be problematic given poor or inconsistent reporting of study methods. Food and feed research makes use of a wide range of study designs so it might be best to focus strategy development on capturing study populations, although this also has challenges. There is limited guidance on which resources should be searched and whether publication bias in disciplines relevant to food and feed necessitates extensive searching of the grey literature. Conclusions There is some limited evidence on information retrieval approaches, but more research is required to inform effective and efficient approaches to searching to populate food and feed reviews

    Fully Integrated CMOS Phase-Locked Loop With 30MHz to 2GHz Locking Range and +-35ps Jitter

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    A fully integrated phase-locked loop (PLL) fabricated in a 0.24 micrometer, 2.5v digital CMOS technology is described. The PLL is intended for use in multi-gigabit-per-second clock recovery circuits in fiber-optic communication chip. This PLL first time achieved a very large locking range measured to be from 30MHz up to 2GHz in 0.24 micrometer CMOS technology. Also it has very low peak-to-peak jitter less than +-35ps at 1.25GHz output frequency

    A Fully Integrated CMOS Phase-Locked Loop With 30MHz to 2GHz Locking Range and ±35 ps Jitter

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    A fully integrated phase-locked loop (PLL) fabricated in a 0.24μm, 2.5v digital CMOS technology is described. The PLL is intended for use in multi-gigabit-per-second clock recovery circuits in fiber-optic communication chips. This PLL first time achieved a very large locking range measured to be from 30MHz up to 2GHz in 0.24μm CMOS technologies. Also it has very low peak-to-peak jitter less than ±35ps at 1.25GHz output frequency

    An Extended Frequency Range CMOS Voltage-Controlled Oscillator

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    This paper presents an extended frequency range CMOS monolithic voltage-controlled oscillator (VCO) design. A negative feedback control algorithm is used to automatically adjust the VCO range according to the control voltage. Based on this analog feedback control algorithm, the VCO achieves a wide range without any pre-register settings. Low phase noise is achieved by using both coarse control and fine control in VCO. A 600 MHz to 3.3 GHz monolithic CMOS PLL based on this wide range and low phase noise VCO has been fabricated in TSMC 0.18 μm, 1.8V CMOS technology and is used in many different applications such as FC, GE, and SONET etc

    Methodological Quality Assessment of Review Articles Evaluating Interventions to Improve Microbial Food Safety

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    Review articles are a means of summarizing the potentially vast volume of research on a topic. However, the methodological quality of review articles varies, and reviews on the same topic may reach different conclusions. We evaluated 65 review articles published between 2000 and 2005 that addressed the effectiveness of microbial food safety interventions, using criteria for methodological soundness developed in the medical field. Overall, the methodological quality of the review articles was poor, with none of the reviews providing information on the method of locating primary research studies or the inclusion/exclusion criteria for selecting primary studies. None of the reviews included a critical appraisal of the methodological quality of the primary studies. Less than half of the reviews stated a focused research question, explored possible reasons for differences in the results of primary studies, discussed the generalizability of results, or proposed directions for future research. There is a need to improve the methodological quality of review articles on microbial food safety interventions if they are to be of use in policy and decision making
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