3,075 research outputs found
Analyzing the Welfare Impacts of Full-line Forcing Contracts
Theoretical investigations have examined both anti-competitive and efficiency-inducing rationales for vertical bundling, making empirical evidence important to understanding its welfare implications. We use an extensive dataset on full-line forcing contracts between movie distributors and video retailers to empirically measure the impact of vertical bundling on welfare. We identify and measure three primary effects of fullline forcing contracts: market coverage, leverage, and efficiency. We find that bundling increases market coverage and efficiency, but has little impact on one distributor gaining leverage over another. As a result, we estimate that full-line forcing contracts increased consumer and producer surplus in this application.
The Use of Full-line Forcing Contracts in the Video Rental Industry
We provide an empirical study of bundling in a supply chain, referred to as fullline forcing. We use an extensive dataset on contracts between video retailers and movie distributors to analyze the choices made on both sides of the market: which distributors offer full-line forcing contracts, which retailers take them up, and whether their decisions are profitable. Most large distributors offer full-line forcing contracts in our data. Our simulations indicate that their choices of which contracts to offer are profit-maximizing. However, many retailers prefer to utilize linear pricing contracts even when our model indicates that this may not be profit-maximizing.
Ibuprofen Blunts Ventilatory Acclimatization to Sustained Hypoxia in Humans.
Ventilatory acclimatization to hypoxia is a time-dependent increase in ventilation and the hypoxic ventilatory response (HVR) that involves neural plasticity in both carotid body chemoreceptors and brainstem respiratory centers. The mechanisms of such plasticity are not completely understood but recent animal studies show it can be blocked by administering ibuprofen, a nonsteroidal anti-inflammatory drug, during chronic hypoxia. We tested the hypothesis that ibuprofen would also block the increase in HVR with chronic hypoxia in humans in 15 healthy men and women using a double-blind, placebo controlled, cross-over trial. The isocapnic HVR was measured with standard methods in subjects treated with ibuprofen (400 mg every 8 hrs) or placebo for 48 hours at sea level and 48 hours at high altitude (3,800 m). Subjects returned to sea level for at least 30 days prior to repeating the protocol with the opposite treatment. Ibuprofen significantly decreased the HVR after acclimatization to high altitude compared to placebo but it did not affect ventilation or arterial O2 saturation breathing ambient air at high altitude. Hence, compensatory responses prevent hypoventilation with decreased isocapnic ventilatory O2-sensitivity from ibuprofen at this altitude. The effect of ibuprofen to decrease the HVR in humans provides the first experimental evidence that a signaling mechanism described for ventilatory acclimatization to hypoxia in animal models also occurs in people. This establishes a foundation for the future experiments to test the potential role of different mechanisms for neural plasticity and ventilatory acclimatization in humans with chronic hypoxemia from lung disease
Comparative performance of human and mobile robotic assistants in collaborative fetch-and-deliver tasks
There is an emerging desire across manufacturing industries to deploy robots that support people in their manual work, rather than replace human workers. This paper explores one such opportunity, which is to field a mobile robotic assistant that travels between part carts and the automotive final assembly line, delivering tools and materials to the human workers. We compare the performance of a mobile robotic assistant to that of a human assistant to gain a better understanding of the factors that impact its effectiveness. Statistically significant differences emerge based on type of assistant, human or robot. Interaction times and idle times are statistically significantly higher for the robotic assistant than the human assistant. We report additional differences in participant's subjective response regarding team fluency, situational awareness, comfort and safety. Finally, we discuss how results from the experiment inform the design of a more effective assistant.BMW Grou
Microtubule Reorganization during Mitosis and Cytokinesis: Lessons Learned from Developing Microgametophytes in Arabidopsis Thaliana
In angiosperms, mitosis and cytokinesis take place in the absence of structurally defined microtubule-organizing centers and the underlying mechanisms are largely unknown. In the spindle and phragmoplast, microtubule reorganization depends on microtubule-interacting factors like the γ-tubulin complex. Because of their critical functions in cell division, loss-of-function mutations in the corresponding genes are often homozygous or sporophytic lethal. However, a number of mutations like gem1, gcp2, and nedd1 can be maintained in heterozygous mutants in Arabidopsis thaliana. When mutant microspores produced by a heterozygous parent undergo pollen mitosis I, they are amenable for phenotypic characterization by fluorescence microscopy. The results would allow us to pinpoint at specific functions of particular proteins in microtubule reorganization that are characteristic to specific stages of mitosis and cytokinesis. Conclusions made in the developing microgametophytes can be extrapolated to somatic cells regarding mechanisms that regulate nuclear migration, spindle pole formation, phragmoplast assembly, and cell division plane determination
Innovative Approach to Measure Effectiveness of Handwashing Education in School-Age Children by Extension Educators
University of Idaho Extension educators developed an innovative approach to analyze the effectiveness of handwashing lessons taught to school-age children. A protocol was designed to determine if there was a significant decrease in bacterial Colony Forming Units (CFUs) before and after implementing an educational handwashing lesson. The protocol allowed Extension educators with limited to no research experience to validate their handwashing lessons with scientific research. A 79% reduction in Mean CFU counts pre- and post-handwashing was found, excluding an outlier. The results support the effectiveness of Extension handwashing lessons using a novel quantitative approac
Southwest Detroit Wind Feasibility Study
http://deepblue.lib.umich.edu/bitstream/2027.42/120378/1/BajaGainesHoMartinSchneiderSklar_SouthwestDetroitWindFeasibilityStudy.pd
Tumor protein Tctp regulates axon development in the embryonic visual system.
The transcript encoding translationally controlled tumor protein (Tctp), a molecule associated with aggressive breast cancers, was identified among the most abundant in genome-wide screens of axons, suggesting that Tctp is important in neurons. Here, we tested the role of Tctp in retinal axon development in Xenopus laevis We report that Tctp deficiency results in stunted and splayed retinotectal projections that fail to innervate the optic tectum at the normal developmental time owing to impaired axon extension. Tctp-deficient axons exhibit defects associated with mitochondrial dysfunction and we show that Tctp interacts in the axonal compartment with myeloid cell leukemia 1 (Mcl1), a pro-survival member of the Bcl2 family. Mcl1 knockdown gives rise to similar axon misprojection phenotypes, and we provide evidence that the anti-apoptotic activity of Tctp is necessary for the normal development of the retinotectal projection. These findings suggest that Tctp supports the development of the retinotectal projection via its regulation of pro-survival signalling and axonal mitochondrial homeostasis, and establish a novel and fundamental role for Tctp in vertebrate neural circuitry assembly.This work was supported by Fundação para a Ciência e Tecnologia (C.G.R.; fellowship SFRH/BD/33891/2009), Sir Edward Youde Memorial Fund, Croucher Foundation, Cambridge Commonwealth–European & International Trust (H.W.), Gates Cambridge Scholarship (J.Q.L.), and a Wellcome Trust Programme Grant (C.E.H.; grant 085314/Z/08/Z).This is the final version of the article. It first appeared from The Company of Biologists via http://dx.doi.org/10.1242/dev.13106
Multidisciplinary Perspectives on Signalling Text Organisation: Introduction to the Special Issue.
International audienceTexts are organised wholes. Understanding a text entails constructing a representation of its organisation. Several research domains, with different assumptions and objectives, have taken an interest in the devices which seem to help readers in this process. As a consequence, research concerned with the signalling of text organisation is far from constituting a unified field. The notion of signal itself may be associated with different key concepts according to discipline and theoretical underpinning: document structure, discourse organisation, layout structure, text architecture, etc. As far as function is concerned, signals may be seen as discourse construction devices, as metadiscourse, as reading or processing instructions, as traces of the writer's cognitive processes, as cues revealing the author's intentions... This special issue, which follows on from the MAD 2010 workshop in Moissac (http://w3.workshop-mad2010.univ-tlse2.fr), is a first step towards the development of multidisciplinary approaches: by bringing together perspectives from different disciplines interested in the signalling of text organisation --linguists, computational linguists, psycholinguists, educational/cognitive psychologists, document designers-- we aim to contribute to mutual understanding and cross-fertilisation. We urge readers to resist the temptation to stay smugly within their own field, and invite them to find out what research in other disciplines brings up in relation to text organisation signals. Though this issue is modestly multidisciplinary in the sense that it mostly brings together research from different fields, it is also more ambitiously so in the first two papers, which present approaches associating several disciplines: cognitive psychology and linguistics for the first, information design (and architecture...) and linguistics for the second.Les textes étant des ensembles organisés, comprendre un texte passe par la construction d'une représentation de cette organisation. Différentes disciplines s'intéressent aux dispositifs qui guident le lecteur dans ce processus de construction, avec des hypothèses, des méthodes et des objectifs très variés. Il en résulte que les différents travaux de recherche relatifs à la signalisation de l'organisation des textes sont loin de constituer un champ unifié. La notion même de " signalisation " est associée à différents concepts selon les disciplines et les théories adoptées : structure de document, organisation discursive, structure visuelle, architecture textuelle, etc. Du point de vue fonctionnel, les signaux (i. e. les éléments signalant l'organisation des textes) peuvent être vus comme des dispositifs participant à la construction du discours, des indications métadiscursives, des instructions de lecture et de traitement du texte, des traces reflétant les processus de rédaction, des indices révélant les intentions de l'auteur... Ce numéro thématique consacré à la " signalisation de l'organisation des textes ", qui fait suite au colloque MAD organisé à Moissac en mars 2010 (http://w3.workshop-mad2010.univ-tlse2.fr), constitue une première étape vers le développement d'approches multidisciplinaires : en rassemblant des perspectives issues de différentes disciplines intéressées par la signalisation de l'organisation du texte - linguistique, TAL (Traitement Automatique du Langage), psycholinguistique, psychologie cognitive, " document design " -, nous cherchons à favoriser la compréhension mutuelle et la fertilisation croisée. Nous encourageons ainsi le lecteur à résister à la tentation de rester confortablement dans son champ d'étude et l'invitons à découvrir l'apport d'autres disciplines à la question de la " signalisation de l'organisation des textes ". Bien que l'ambition multidisciplinaire de ce numéro spécial réside modestement dans le regroupement de travaux issus de différents domaines, les deux premiers articles associent plus audacieusement différentes disciplines : psychologie cognitive et linguistique pour le premier, linguistique et " document design " (et architecture...) pour le second
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