608 research outputs found

    A note on the effect of supplementation with microbial phytase and organic acids on feed intake and growth performance of growing pigs

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    peer-reviewedThis experiment was designed to investigate the effects of supplementation with phytase, either alone or in combination with organic acids, on feed intake and growth of pigs from 8 to 89 kg live weight. Some 240 pigs were used in four experimental treatments comprising: (1) control, (2) control plus phytase, (3) control plus phytase plus liquid organic acids (formic, propionic), and (4) control plus phytase plus powdered organic acids (formic, fumaric, propionic). Feed intake and growth rate in the weaner stage were increased (P < 0.05) by phytase supplementation, with some additional benefits from organic acid inclusion. Interval to slaughter was reduced (P < 0.05) by phytase supplementation

    Comparison of synthetic membranes in the development of an in vitro feeding system for Dermanyssus gallinae

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    Although artificial feeding models for the poultry red mite (Dermanyssus gallinae) most frequently use biological membranes consisting of day-old chick skin, there are ethical considerations associated with the use of skin. The few studies reported in the literature that have investigated the use of synthetic membranes to feed D. gallinae in vitro have reported limited success. The current study describes an investigation into the use of synthetic membranes made from either Nescofilm® or rayon and silicone, used either alone or in combination with different feather or skin extracts, as well as the use of capillary tubes. In all, 12 different treatments were used, and the feeding rate of D. gallinae was compared to that of day-old chick skin. Allowing mites to feed on a membrane consisting of Nescofilm with a skin extract resulted in the highest proportion of mites feeding (32.3%), which was not significantly different to the feeding rate of mites on day-old chick skin (38.8%). This study confirms that synthetic membranes can be used to feed D. gallinae artificially. Further optimization of the membrane and mite storage conditions is still necessary, but the study demonstrates a proof of concept

    Використання словникових технологій у процесі вивчення іноземних мов

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    Методичні рекомендації щодо використання словникових технологій складаються з теоретичної і прикладної частин. Теоретична частина подає характеристики основних типів словників і рекомендації щодо користування ними. Прикладна частина містить добірку завдань з основних видів робіт з урахуванням тем навчальних програм для студентів різних спеціальностей денної та заочної форми навчання, які володіють основами граматики, необхідним лексичним запасом для розуміння запропонованого матеріалу й навичками усного мовлення. Рекомендуються для використання на практичних заняттях, а також для самостійної роботи студентів із залученням словників різних типів. Ці методичні рекомендації розроблені з метою надання методичної допомоги викладачам і студентам у процесі роботи зі словником під час вивчення іноземних мов. Книга включає безліч пропозицій для формування вмінь і навичок роботи зі словником на заняттях і під час самостійної роботи. Теоретична частина написана українською мовою та подає роз’яснення особливостей словників різних типів, способів їх використання й умови оптимального вибору словника. Прикладна частина на матеріалі англійської мови пропонує основні види роботи зі словником, спрямовані на формування вмінь і навичок правильної вимови, читання, письма, граматики, перекдау, а також збагаченя власного словникового запасу. Для кожного виду роботи зі словником підібрано п’ять завдань по темах робочих програм з навчальної дисципліни “Англійська мова” для студентів вищих навчальних закладів. Крім того, запропоновані матеріали розкривають такі теми, як сполученя слів, фразові дієслова, ідіоми та словотворення. Види роботи зі словником спрямовані на використання не тільки традиційних паперових, а й електронних та інших нестандартних спеціалізованих словників. Матеріал цих рекомендацій може бути використаний як джерело навчальної та практичної інформації для викладачів і студентів різних спеціальностей. Автор сподівається, що методичні рекомендації будуть цінними для будь-якого користувача, який хоче поліпшити своє особисте знання словника

    Opportunities for integrated pest management to control the poultry red mite, Dermanyssus gallinae

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    Dermanyssus gallinae is the most economically important ectoparasite of laying hens in Europe. Control of D. gallinae is already hampered by issues of pesticide resistance and product withdrawal and, with the prohibition of conventional cages in 2012 and the resulting switch to more structurally complex housing which favours red mite, the importance of managing this pest will increase. Integrated Pest Management (IPM), as often employed in agricultural pest control, may be a way to address these issues where a combination of different novel control methods could be used with/without conventional management techniques to provide a synergistic and more efficacious effect. Work at in our laboratory has shown that essential oils including thyme and garlic may act as effective D. gallinae repellents and acaricides, whilst preliminary vaccine studies have demonstrated a significant increase in mite mortality in vitro using concealed antigens. Work elsewhere 27 has considered predators and fungi for D. gallinae control and other husbandry techniques such as manipulating temperature and lighting regimes in poultry units. This paper will review the available and emerging techniques for D. gallinae control and discuss which techniques might be suitable for inclusion in an integrated management programme (e.g. synthetic acaricides and diatomaceous earths)

    Graph Treewidth and Geometric Thickness Parameters

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    Consider a drawing of a graph GG in the plane such that crossing edges are coloured differently. The minimum number of colours, taken over all drawings of GG, is the classical graph parameter "thickness". By restricting the edges to be straight, we obtain the "geometric thickness". By further restricting the vertices to be in convex position, we obtain the "book thickness". This paper studies the relationship between these parameters and treewidth. Our first main result states that for graphs of treewidth kk, the maximum thickness and the maximum geometric thickness both equal k/2\lceil{k/2}\rceil. This says that the lower bound for thickness can be matched by an upper bound, even in the more restrictive geometric setting. Our second main result states that for graphs of treewidth kk, the maximum book thickness equals kk if k2k \leq 2 and equals k+1k+1 if k3k \geq 3. This refutes a conjecture of Ganley and Heath [Discrete Appl. Math. 109(3):215-221, 2001]. Analogous results are proved for outerthickness, arboricity, and star-arboricity.Comment: A preliminary version of this paper appeared in the "Proceedings of the 13th International Symposium on Graph Drawing" (GD '05), Lecture Notes in Computer Science 3843:129-140, Springer, 2006. The full version was published in Discrete & Computational Geometry 37(4):641-670, 2007. That version contained a false conjecture, which is corrected on page 26 of this versio

    Loop-Generated Bounds on Changes to the Graviton Dispersion Relation

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    We identify the effective theory appropriate to the propagation of massless bulk fields in brane-world scenarios, to show that the dominant low-energy effect of asymmetric warping in the bulk is to modify the dispersion relation of the effective 4-dimensional modes. We show how such changes to the graviton dispersion relation may be bounded through the effects they imply, through loops, for the propagation of standard model particles. We compute these bounds and show that they provide, in some cases, the strongest constraints on nonstandard gravitational dispersions. The bounds obtained in this way are the strongest for the fewest extra dimensions and when the extra-dimensional Planck mass is the smallest. Although the best bounds come for warped 5-D scenarios, for which the 5D Planck Mass is O(TeV), even in 4 dimensions the graviton loop can lead to a bound on the graviton speed which is comparable with other constraints.Comment: 18 pages, LaTeX, 4 figures, uses revte

    The effect of steps to promote higher levels of farm animal welfare across the EU. Societal versus animal scientists’ perceptions of animal welfare

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    Information about animal welfare standards and initiatives from eight European countries was collected, grouped, and compared to EU welfare standards to detect those aspects beyond minimum welfare levels demanded by EU welfare legislation. Literature was reviewed to determine the scientific relevance of standards and initiatives, and those aspects going beyond minimum EU standards. Standards and initiatives were assessed to determine their strengths and weaknesses regarding animal welfare. Attitudes of stakeholders in the improvement of animal welfare were determined through a Policy Delphi exercise. Social perception of animal welfare, economic implications of upraising welfare levels, and differences between countries were considered. Literature review revealed that on-farm space allowance, climate control, and environmental enrichment are relevant for all animal categories. Experts’ assessment revealed that on-farm prevention of thermal stress, air quality, and races and passageways’ design were not sufficiently included. Stakeholders considered that housing conditions are particularly relevant regarding animal welfare, and that animal-based and farm-level indicators are fundamental to monitor the progress of animal welfare. The most notable differences between what society offers and what farm animals are likely to need are related to transportation and space availability, with economic constraints being the most plausible explanation

    An expandable embryonic stem cell-derived Purkinje neuron progenitor population that exhibits in vivo maturation in the adult mouse cerebellum

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    The directed differentiation of patient-derived induced pluripotent stem cells into cell-type specific neurons has inspired the development of therapeutic discovery for neurodegenerative diseases. Many forms of ataxia result from degeneration of cerebellar Purkinje cells, but thus far it has not been possible to efficiently generate Purkinje neuron (PN) progenitors from human or mouse pluripotent stem cells, let alone to develop a methodology for in vivo transplantation in the adult cerebellum. Here, we present a protocol to obtain an expandable population of cerebellar neuron progenitors from mouse embryonic stem cells. Our protocol is characterized by applying factors that promote proliferation of cerebellar progenitors. Cerebellar progenitors isolated in culture from cell aggregates contained a stable subpopulation of PN progenitors that could be expanded for up to 6 passages. When transplanted into the adult cerebellum of either wild-type mice or a strain lacking Purkinje cells (L7cre-ERCC1 knockout), GFP-labeled progenitors differentiated in vivo to establish a population of calbindin-positive cells in the molecular layer with dendritic trees typical of mature PNs. We conclude that this protocol may be useful for the generation and maturation of PNs, highlighting the potential for development of a regenerative medicine approach to the treatment of cerebellar neurodegenerative diseases

    A simplified protocol for differentiation of electrophysiologically mature neuronal networks from human induced pluripotent stem cells

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    Progress in elucidating the molecular and cellular pathophysiology of neuropsychiatric disorders has been hindered by the limited availability of living human brain tissue. The emergence of induced pluripotent stem cells (iPSCs) has offered a unique alternative strategy using patient-derived functional neuronal networks. However, methods for reliably generating iPSC-derived neurons with mature electrophysiological characteristics have been difficult to develop. Here, we report a simplified differentiation protocol that yields electrophysiologically mature iPSC-derived cortical lineage neuronal networks without the need for astrocyte co-culture or specialized media. This protocol generates a consistent 60:40 ratio of neurons and astrocytes that arise from a common forebrain neural progenitor. Whole-cell patch-clamp recordings of 114 neurons derived from three independent iPSC lines confirmed their electrophysiological maturity, including resting membrane potential (−58.2±1.0 mV), capacitance (49.1±2.9 pF), action potential (AP) threshold (−50.9±0.5 mV) and AP amplitude (66.5±1.3 mV). Nearly 100% of neurons were capable of firing APs, of which 79% had sustained trains of mature APs with minimal accommodation (peak AP frequency: 11.9±0.5 Hz) and 74% exhibited spontaneous synaptic activity (amplitude, 16.03±0.82 pA; frequency, 1.09±0.17 Hz). We expect this protocol to be of broad applicability for implementing iPSC-based neuronal network models of neuropsychiatric disorders.Molecular Psychiatry advance online publication, 18 April 2017; doi:10.1038/mp.2017.56

    An intervention study to prevent relapse in patients with schizophrenia

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    Purpose: To determine whether the use of relapse prevention plans (RPPs) in nursing practice is an effective intervention in reducing relapse rates among patients with schizophrenia. Design and Methods: Experimental design. Patients with schizophrenia (or a related psychotic disorder) and nurses from three mental health organizations were randomly assigned to either an experimental (RPP) or control condition (care as usual). The primary outcome measure was the psychotic relapses in the research groups. Results: The relapse rates in the experimental and control groups after 1-year follow-up were 12.5% and 26.2%, respectively (p=.12, ns). The relative risk of a relapse in the experimental versus the control group was 0.48(ns). Conclusions: In this study no statistically significant effects of the intervention were found. Effectiveness research in this area should be continued with larger sample sizes and longer follow-up periods
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