186 research outputs found

    Bewertung von Pflanzenbeständen und Milchleistung in Ökobetrieben Nordwestdeutschlands

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    In order to produce high quality forages, the species composition of the grass sward is of special importance. A good measure for estimating the quality of grass swards is the so-called mean Futterwertzahl of the sward by Klapp (1965) which is further referred to as Sward Quality Index (SQI). On 56 organic farms the average SQI of the farm has been calculated and the yield proportion of different species of the sward has been calculated for different regions of Northwest Germany. Within 22 organic farms with grassland farming exclusively, a comparison of the milk yields (kg ECM/cow and year) and the mean SQI of the grassland has been calculated with special regard to the concentrate rates fed to the cows. In tendency the results show lower SQI in farms with lower milk yields in comparison to farms with higher SQI. However, the evaluations show high variations, indicating, that other factors (management, animal health problems, cutting dates and forage quality factors) might have influenced the result

    Untersuchungen zu Fütterung, Milchleistung und Tiergesundheit von Milchkühen im Ökologischen Landbau

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    The breeding scheme entails yield differences of more than 2 000 kg energy corrected milk (ECM) per cow and year. On average, farms feeding less concentrate yielded slightly lower milk yields per cow and year, however, because of the longer productive life the cows showed similar milk yields over their lifetime. The farms investigated so far appeared to have healthy cows, even if fed low levels of concentrates or in the case of extremely low or high urea contents in the milk. These values could indicate the cows’ ability to compensate for short-dated changes

    Kraftfuttergaben und Milchleistung bei Weidegang von Milchviehherden im ökologischen Landbau

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    During grazing, the efficiency of concentrate feeding on milk yields is low, especially when white clover is present in the sward (Wilkens et al., 1994). Clover in animal feed enhances forage intake; feeding trials have shown increased intake rates by 15-30 % (Paul, 2003). These results are of special interest for organic farms, where clover has a higher impact on the farming system. In the experimental organic farm of the Landwirtschaftskammer Nordrhein-Westfalen (Haus Riswick) the concentrate rate fed during grazing time showed no influence upon milk yields (2,6 resp.4,7 kg DM concentrate/ animal/day). In agreement with these results a three years investigation on 89 organic farms in Northwest Germany showed no effect of concentrate feeding on milk yield during the grazing season. Furthermore, a reduction or increase of concentrate rates during the grazing season did not show any differences in animal health so far

    Geochemical and micro-textural fingerprints of boiling in pyrite

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    The chemical composition, textures and mineral associations of pyrite provide key information that help elucidate the evolution of hydrothermal systems. However, linking the compositional and micro-textural features of pyrite with a specific physico-chemical process, e.g., boiling versus non-boiling, remains elusive and challenging. In this study we examine pyrite geochemical and micro-textural features and relate these results to pyrite-forming processes at the active Cerro Pabellón Geothermal System (CPGS) in the Altiplano of the northern Chile. We integrate electron microprobe analysis (EMPA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) data with micro-textural observations of pyrite and associated gangue minerals recovered from a ∼500 m long drill core that crosscuts the argillic, sub-propylitic and propylitic alteration zones of the CPGS. Additionally, we carried out a Principal Component Analysis (PCA) in order to inspect and understand the main data structure of the pyrite geochemical dataset. The concentrations of precious metals (Au and Ag), metalloids (As, Sb, Se, Bi and Tl), and base and heavy metals (Cu, Co, Ni and Pb) in pyrite from the CPGS are significant. Among the elements analyzed, As, Cu and Pb are the most abundant with concentrations that vary from a few parts per million (ppm) to wt% levels (up to 4.4 wt% of As, 0.5 wt% of Cu and 0.2 wt% of Pb). Based on contemporaneous gangue mineral associations and textures, the mechanisms of pyrite precipitation in the CPGS were inferred. Pyrite formed during vigorous boiling is characterized by relatively high concentrations of As, Cu, Pb, Ag and Au and lower concentrations of Co and Ni compared to pyrite formed under different conditions. These anhedral to euhedral pyrite grains display zones with a porous texture and abundant mineral micro- to nano-inclusions (mainly galena and chalcopyrite) indicating a formation by rapid crystallization. In contrast, pyrite formed under gentle boiling (more gradual cooling and less abrupt physico-chemical variations than in vigorous boiling) to non-boiling conditions is characterized by a higher concentration of Co and Ni, and relatively low concentrations of As, Cu, Pb, Ag and Au. Texturally, these pyrites form aggregates of euhedral and pristine pyrite crystals with scarce pores and mineral inclusions suggesting formation under steadier physico-chemical conditions. Our results show that pyrite can not only record the chemical evolution of hydrothermal fluids, but can also provide critical information related to physico-chemical process such as boiling and phase separation. Since boiling of aqueous fluids is a common phenomenon occurring in a variety of pyrite-forming environments, e.g., active continental and seafloor hydrothermal systems, and porphyry Cu-epithermal Au-Ag deposits, pyrite compositional and textural features are a valuable complement for discriminating and tracking boiling events in modern and fossil hydrothermal systems

    Generalized Species Sampling Priors with Latent Beta reinforcements

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    Many popular Bayesian nonparametric priors can be characterized in terms of exchangeable species sampling sequences. However, in some applications, exchangeability may not be appropriate. We introduce a {novel and probabilistically coherent family of non-exchangeable species sampling sequences characterized by a tractable predictive probability function with weights driven by a sequence of independent Beta random variables. We compare their theoretical clustering properties with those of the Dirichlet Process and the two parameters Poisson-Dirichlet process. The proposed construction provides a complete characterization of the joint process, differently from existing work. We then propose the use of such process as prior distribution in a hierarchical Bayes modeling framework, and we describe a Markov Chain Monte Carlo sampler for posterior inference. We evaluate the performance of the prior and the robustness of the resulting inference in a simulation study, providing a comparison with popular Dirichlet Processes mixtures and Hidden Markov Models. Finally, we develop an application to the detection of chromosomal aberrations in breast cancer by leveraging array CGH data.Comment: For correspondence purposes, Edoardo M. Airoldi's email is [email protected]; Federico Bassetti's email is [email protected]; Michele Guindani's email is [email protected] ; Fabrizo Leisen's email is [email protected]. To appear in the Journal of the American Statistical Associatio

    Doctor of Education Newsletter 2020

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    WSU Doctor of Education Cohort 2020 This newsletter was created by the second Education Doctorate graduate student cohort 2020.https://openriver.winona.edu/educationeddnewsletters/1001/thumbnail.jp

    String-like Clusters and Cooperative Motion in a Model Glass-Forming Liquid

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    A large-scale molecular dynamics simulation is performed on a glass-forming Lennard-Jones mixture to determine the nature of dynamical heterogeneities which arise in this model fragile liquid. We observe that the most mobile particles exhibit a cooperative motion in the form of string-like paths (``strings'') whose mean length and radius of gyration increase as the liquid is cooled. The length distribution of the strings is found to be similar to that expected for the equilibrium polymerization of linear polymer chains.Comment: 6 pages of RevTex, 6 postscript figures, uses epsf.st

    Objective Bayesian Analysis of the Yule-Simon Distribution with Applications

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    The Yule-Simon distribution is usually employed in the analysis of frequency data. As the Bayesian literature, so far, has ignored this distribution, here we show the derivation of two objective priors for the parameter of the Yule--Simon distribution. In particular, we discuss the Jeffreys prior and a loss-based prior, which has recently appeared in the literature. We illustrate the performance of the derived priors through a simulation study and the analysis of real datasets

    What do measures of patient satisfaction with the doctor tell us?

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    Objective: To gain an understanding of how patient satisfaction (PS) with the doctor (PSD) is conceptualized through an empirical review of how it is currently being measured. The content of PS questionnaire items was examined to (a) determine the primary domains underlying PSD, and (b) summarize the specific doctor-related characteristics and behaviors, and patient-related perceptions, composing each domain. Methods: A scoping review of empirical articles that assessed PSD published from 2000 to November 2013. MEDLINE and PsycINFO databases were searched. Results: The literature search yielded 1726 articles, 316 of which fulfilled study inclusion criteria. PSD was realized in one of four health contexts, with questions being embedded in a larger questionnaire that assessed PS with either: (1) overall healthcare, (2) a specific medical encounter, or (3) the healthcare team. In the fourth context, PSD was the questionnaire's sole focus. Five broad domains underlying PSD were revealed: (1) Communication Attributes; (2) Relational Conduct; (3) Technical Skill/Knowledge; (4) Personal Qualities; and (5) Availability/Accessibility. Conclusions: Careful consideration of measurement goals and purposes is necessary when selecting a PSD measure. Practice implications: The five emergent domains underlying PSD point to potential key areas of physician training and foci for quality assessment

    Residents' support for tourism development: The role of residents' place image and perceived tourism impacts

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    Drawing on the triple bottom line approach for tourism impacts (economic, socio-cultural and environmental) and adopting a non-forced approach for measuring residents' perception of these impacts, this study explores the role of residents' place image in shaping their support for tourism development. The tested model proposes that residents' place image affects their perceptions of tourism impacts and in turn their support for tourism development. The results stress the need for a more flexible and resident oriented measurement of tourism impacts, revealing that more favorable perceptions of the economic, socio-cultural and environmental impacts lead to greater support. Moreover, while residents' place image has been largely neglected by tourism development studies, the findings of this study reveal its significance in shaping residents' perception of tourism impacts as well as their level of support. The practical implications of the findings for tourism planning and development are also discussed
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