32 research outputs found

    ARRIVAL:Next stop in CLS

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    ARRIVAL: Next Stop in CLS

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    We study the computational complexity of ARRIVAL, a zero-player game on nn-vertex switch graphs introduced by Dohrau, G\"{a}rtner, Kohler, Matou\v{s}ek, and Welzl. They showed that the problem of deciding termination of this game is contained in NPcoNP\text{NP} \cap \text{coNP}. Karthik C. S. recently introduced a search variant of ARRIVAL and showed that it is in the complexity class PLS. In this work, we significantly improve the known upper bounds for both the decision and the search variants of ARRIVAL. First, we resolve a question suggested by Dohrau et al. and show that the decision variant of ARRIVAL is in UPcoUP\text{UP} \cap \text{coUP}. Second, we prove that the search variant of ARRIVAL is contained in CLS. Third, we give a randomized O(1.4143n)\mathcal{O}(1.4143^n)-time algorithm to solve both variants. Our main technical contributions are (a) an efficiently verifiable characterization of the unique witness for termination of the ARRIVAL game, and (b) an efficient way of sampling from the state space of the game. We show that the problem of finding the unique witness is contained in CLS, whereas it was previously conjectured to be FPSPACE-complete. The efficient sampling procedure yields the first algorithm for the problem that has expected runtime O(cn)\mathcal{O}(c^n) with c<2c<2.Comment: 13 pages, 6 figure

    Wann würden Frauen für Tarifkommissionen kandidieren? Befunde aus einem faktoriellen Survey

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    Verhandlungsergebnisse hängen unter anderem davon ab, ob Gruppen in Verhandlungen vertreten sind. Dies legt nahe, dass sich die geschlechtsspezifische Lohnlücke unter anderem durch eine stärkere Beteiligung von Frauen an Tarifkommissionen abbauen ließe. Mit Hilfe eines faktoriellen Surveys untersucht dieser Beitrag, wie wahrscheinlich es ist, dass Beschäftigte unter verschiedenen Umständen für eine Gehaltsverhandlungskommission kandidieren würden und welche Einflussmöglichkeiten sie im Fall einer Wahl für sich sehen würden. Frauen geben insgesamt deutlich seltener als Männer an, dass sie für eine Position in der Verhandlungskommission kandidieren würden. Ebenso erwarten sie im Mittel signifikant seltener, in den Verhandlungen etwas bewirken zu können. Dieser Geschlechterunterschied lässt sich durch persönliche und arbeitsplatzbezogene Merkmale der Befragten „erklären“, die aber teilweise wiederum selbst Ergebnis geschlechtsspezifischen Verhaltens sein dürften. Insgesamt deuten die Ergebnisse darauf hin, dass vor allem Regelungen, die eine Anrechenbarkeit von Gremiensitzungen auf die Arbeitszeit festschreiben, dazu geeignet sein können, die Bereitschaft zur Mitarbeit zu erhöhen.Among other things, negotiation results depend on which groups are represented in negotiations. This suggests that a stronger participation of women in collective bargaining commissions could contribute to reducing the gender pay gap. Using a factorial survey, this article examines the likelihood of employees running for wage negotiation commissions under different circumstances, and what influence they expect to have in the case of successfully being elected. Compared to their male counterparts, women are significantly less likely to indicate that they would run for a position on bargainig commissions. Likewise, they expect on average to have significantly less impact on negotiation results. This gender difference can be "explained" by the personal and job-related characteristics of respondents, which are, however, likely to partly result from gender specific behavior. Overall, the results suggest that regulations that ensure committee meetings occur during working hours could increase the willingness of women to participate on wage negotiation commissions

    Minimal information for studies of extracellular vesicles 2018 (MISEV2018):a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines

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    The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points

    26th Annual Computational Neuroscience Meeting (CNS*2017): Part 3 - Meeting Abstracts - Antwerp, Belgium. 15–20 July 2017

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    This work was produced as part of the activities of FAPESP Research,\ud Disseminations and Innovation Center for Neuromathematics (grant\ud 2013/07699-0, S. Paulo Research Foundation). NLK is supported by a\ud FAPESP postdoctoral fellowship (grant 2016/03855-5). ACR is partially\ud supported by a CNPq fellowship (grant 306251/2014-0)

    Improving Usability of Search and Rescue Decision Support Systems : WARA-PS Case Study

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    Novel autonomous search and rescue systems, although powerful, still require a human decision-maker involvement. In this project, we focus on the human aspect of one such novel autonomous SAR system. Relying on the knowledge gained in a field study, as well as through the literature, we introduced several extensions to the system that allowed us to achieve a more user-centered interface. In the evaluation session with a rescue service specialist, we received positive feedback and defined potential directions for future work

    Characterization of light lesion paradigms and optical coherence tomography as tools to study adult retina regeneration in zebrafish

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    Light-induced lesions are a powerful tool to study the amazing ability of photoreceptors to regenerate in the adult zebrafish retina. However, the specificity of the lesion towards photoreceptors or regional differences within the retina are still incompletely understood. We therefore characterized the process of degeneration and regeneration in an established paradigm, using intense white light from a fluorescence lamp on swimming fish (diffuse light lesion). We also designed a new light lesion paradigm where light is focused through a microscope onto the retina of an immobilized fish (focused light lesion). Focused light lesion has the advantage of creating a locally restricted area of damage, with the additional benefit of an untreated control eye in the same animal. In both paradigms, cell death is observed as an immediate early response, and proliferation is initiated around 2 days post lesion (dpl), peaking at 3 dpl. We furthermore find that two photoreceptor subtypes (UV and blue sensitive cones) are more susceptible towards intense white light than red/green double cones and rods. We also observed specific differences within light lesioned areas with respect to the process of photoreceptor degeneration: UV cone debris is removed later than any other type of photoreceptor in light lesions. Unspecific damage to retinal neurons occurs at the center of a focused light lesion territory, but not in the diffuse light lesion areas. We simulated the fish eye optical properties using software simulation, and show that the optical properties may explain the light lesion patterns that we observe. Furthermore, as a new tool to study retinal degeneration and regeneration in individual fish in vivo, we use spectral domain optical coherence tomography. Collectively, the light lesion and imaging assays described here represent powerful tools for studying degeneration and regeneration processes in the adult zebrafish retina

    Evaluating the effectiveness of retention forestry to enhance biodiversity in production forests of Central Europe using an interdisciplinary, multi-scale approach

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    Retention forestry, which retains a portion of the original stand at the time of harvesting to maintain continuity of structural and compositional diversity, has been originally developed to mitigate the impacts of clear-cutting. Retention of habitat trees and deadwood has since become common practice also in continuous-cover forests of Central Europe. While the use of retention in these forests is plausible, the evidence base for its application is lacking, trade-offs have not been quantified, it is not clear what support it receives from forest owners and other stakeholders and how it is best integrated into forest management practices. The Research Training Group ConFoBi (Conservation of Forest Biodiversity in Multiple-use Landscapes of Central Europe) focusses on the effectiveness of retention forestry, combining ecological studies on forest biodiversity with social and economic studies of biodiversity conservation across multiple spatial scales. The aim of ConFoBi is to assess whether and how structural retention measures are appropriate for the conservation of forest biodiversity in uneven-aged and selectively harvested continuous-cover forests of temperate Europe. The study design is based on a pool of 135 plots (1 ha) distributed along gradients of forest connectivity and structure. The main objectives are (a) to investigate the effects of structural elements and landscape context on multiple taxa, including different trophic and functional groups, to evaluate the effectiveness of retention practices for biodiversity conservation; (b) to analyze how forest biodiversity conservation is perceived and practiced, and what costs and benefits it creates; and (c) to identify how biodiversity conservation can be effectively integrated in multifunctional forest management. ConFoBi will quantify retention levels required across the landscape, as well as the socio-economic prerequisites for their implementation by forest owners and managers. ConFoBi's research results will provide an evidence base for integrating biodiversity conservation into forest management in temperate forests
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