131 research outputs found

    Projekt Optimilch: Wirtschaftlichkeit der Vollweidestrategie – Ergebnisse 2000 bis 2010

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    Im Projekt Optimilch (2000–2004) wurde die produktionstechnische Umsetzbarkeit der Vollweidestrategie mit saisonaler Abkalbung für Milchwirtschaftsbetriebe im schweizerischen Mittelland aufgezeigt. Die betriebswirtschaftlichen Perspektiven der Strategie können erst in der vorliegenden Arbeit mit einer Analyse der Vollkosten-Ergebnisse dieser Milchproduktionsbetriebe über den Zeitraum von 1999–2010 Jahren beschrieben werden. Die Strategie erlaubte eine deutliche Senkung der Produktionskosten pro kg Milch, die massgeblich durch die konsequente arbeitstechnische Vereinfachung mittels saisonaler Abkalbung der Herden im Frühjahr und der damit entscheidend verbesserten Arbeitsproduktivität erreicht wurde. Bei kleiner Vergrösserung der Milchmenge lag der Arbeitsverdienst am Ende des Beobachtungszeitraums bei acht von neun Vollweidebetrieben deutlich über dem Schweizer Durchschnitt. Die Strategie stellt im Schweizer Talgebiet eine wirtschaftlich sehr interessante, sozial und ökologisch nachhaltige Alternative zu den etablierten Milchproduktionsstrategien dar

    Projekt Optimilch: Wirtschaftlichkeit der Hochleistungsstrategie – Ergebnisse 2000 bis 2010

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    Im Projekt Optimilch (2000–2004) wurde die produktionstechnische Umsetzbarkeit der Hochleistungs- oder High-Output-Strategie für Milchwirtschaftsbetriebe im schweizerischen Mittelland aufgezeigt. Die damals als erfolgsversprechend beurteilten betriebswirtschaftlichen Perspektiven der Strategie konnten erst mit einer Analyse der Vollkosten- Ergebnisse dieser Milchproduktionsbetriebe über den Zeitraum von 1999–2011 überprüft werden. Die Strategie erlaubte in der Tat eine deutliche Senkung der Produktionskosten pro kg Milch, die massgeblich durch die stark ausgedehnte Milchmenge und der damit entscheidend verbesserten Arbeitsproduktivität erreicht wurde; die Skaleneffekte bewirkten auch eine Reduktion der fremden Strukturkosten je kg Milch. Am Ende des Beobachtungszeitraums lag der Arbeitsverdienst bei drei von sieben Hochleistungsbetrieben deutlich über dem Schweizer Durchschnitt. Diese Strategie kann im Schweizer Talgebiet wirtschaftlich interessant sein, konfrontiert die Betriebsleiterfamilien aber mit ausserordentlichen Herausforderungen

    Do experts see it in slow motion? Altered timing of action simulation uncovers domain-specific perceptual processing in expert athletes

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    Accurate encoding of the spatio-temporal properties of others' actions is essential for the successful implementation of daily activities and, even more, for successful sportive performance, given its role in movement coordination and action anticipation. Here we investigated whether athletes are provided with special perceptual processing of spatio-temporal properties of familiar sportive actions. Basketball and volleyball players and novices were presented with short video-clips of free basketball throws that were partially occluded ahead of realization and were asked to judge whether a subsequently presented pose was either taken from the same throw depicted in the occluded video (action identification task) or temporally congruent with the expected course of the action during the occlusion period (explicit timing task). Results showed that basketball players outperformed the other groups in detecting action compatibility when the pose depicted earlier or synchronous, but not later phases of the movement as compared to the natural course of the action during occlusion. No difference was obtained for explicit estimations of timing compatibility. This leads us to argue that the timing of simulated actions in the experts might be slower than that of perceived actions ("slow-motion" bias), allowing for more detailed representation of ongoing actions and refined prediction abilities

    The abrupt onset of the modern South Asian Monsoon winds

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    The South Asian Monson (SAM) is one of the most intense climatic elements yet its initiation and variations are not well established. Dating the deposits of SAM wind-driven currents in IODP cores from the Maldives yields an age of 12. 9 Ma indicating an abrupt SAM onset, over a short period of 300 kyrs. This coincided with the Indian Ocean Oxygen Minimum Zone expansion as revealed by geochemical tracers and the onset of upwelling reflected by the sediment's content of particulate organic matter. A weaker 'proto-monsoon' existed between 12.9 and 25 Ma, as mirrored by the sedimentary signature of dust influx. Abrupt SAM initiation favors a strong influence of climate in addition to the tectonic control, and we propose that the post Miocene Climate Optimum cooling, together with increased continentalization and establishment of the bipolar ocean circulation, i.e. the beginning of the modern world, shifted the monsoon over a threshold towards the modern system

    An Efficient Coding Hypothesis Links Sparsity and Selectivity of Neural Responses

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    To what extent are sensory responses in the brain compatible with first-order principles? The efficient coding hypothesis projects that neurons use as few spikes as possible to faithfully represent natural stimuli. However, many sparsely firing neurons in higher brain areas seem to violate this hypothesis in that they respond more to familiar stimuli than to nonfamiliar stimuli. We reconcile this discrepancy by showing that efficient sensory responses give rise to stimulus selectivity that depends on the stimulus-independent firing threshold and the balance between excitatory and inhibitory inputs. We construct a cost function that enforces minimal firing rates in model neurons by linearly punishing suprathreshold synaptic currents. By contrast, subthreshold currents are punished quadratically, which allows us to optimally reconstruct sensory inputs from elicited responses. We train synaptic currents on many renditions of a particular bird's own song (BOS) and few renditions of conspecific birds' songs (CONs). During training, model neurons develop a response selectivity with complex dependence on the firing threshold. At low thresholds, they fire densely and prefer CON and the reverse BOS (REV) over BOS. However, at high thresholds or when hyperpolarized, they fire sparsely and prefer BOS over REV and over CON. Based on this selectivity reversal, our model suggests that preference for a highly familiar stimulus corresponds to a high-threshold or strong-inhibition regime of an efficient coding strategy. Our findings apply to songbird mirror neurons, and in general, they suggest that the brain may be endowed with simple mechanisms to rapidly change selectivity of neural responses to focus sensory processing on either familiar or nonfamiliar stimuli. In summary, we find support for the efficient coding hypothesis and provide new insights into the interplay between the sparsity and selectivity of neural responses

    Oncoplastic Breast Consortium consensus conference on nipple-sparing mastectomy

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    Purpose Indications for nipple-sparing mastectomy (NSM) have broadened to include the risk reducing setting and locally advanced tumors, which resulted in a dramatic increase in the use of NSM. The Oncoplastic Breast Consortium consensus conference on NSM and immediate reconstruction was held to address a variety of questions in clinical practice and research based on published evidence and expert panel opinion. Methods The panel consisted of 44 breast surgeons from 14 countries across four continents with a background in gynecology, general or reconstructive surgery and a practice dedicated to breast cancer, as well as a patient advocate. Panelists presented evidence summaries relating to each topic for debate during the in-person consensus conference. The iterative process in question development, voting, and wording of the recommendations followed the modified Delphi methodology. Results Consensus recommendations were reached in 35, majority recommendations in 24, and no recommendations in the remaining 12 questions. The panel acknowledged the need for standardization of various aspects of NSM and immediate reconstruction. It endorsed several oncological contraindications to the preservation of the skin and nipple. Furthermore, it recommended inclusion of patients in prospective registries and routine assessment of patient-reported outcomes. Considerable heterogeneity in breast reconstruction practice became obvious during the conference. Conclusions In case of conflicting or missing evidence to guide treatment, the consensus conference revealed substantial disagreement in expert panel opinion, which, among others, supports the need for a randomized trial to evaluate the safest and most efficacious reconstruction techniques

    Aerosols Transmit Prions to Immunocompetent and Immunodeficient Mice

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    Prions, the agents causing transmissible spongiform encephalopathies, colonize the brain of hosts after oral, parenteral, intralingual, or even transdermal uptake. However, prions are not generally considered to be airborne. Here we report that inbred and crossbred wild-type mice, as well as tga20 transgenic mice overexpressing PrPC, efficiently develop scrapie upon exposure to aerosolized prions. NSE-PrP transgenic mice, which express PrPC selectively in neurons, were also susceptible to airborne prions. Aerogenic infection occurred also in mice lacking B- and T-lymphocytes, NK-cells, follicular dendritic cells or complement components. Brains of diseased mice contained PrPSc and transmitted scrapie when inoculated into further mice. We conclude that aerogenic exposure to prions is very efficacious and can lead to direct invasion of neural pathways without an obligatory replicative phase in lymphoid organs. This previously unappreciated risk for airborne prion transmission may warrant re-thinking on prion biosafety guidelines in research and diagnostic laboratories
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