1,953 research outputs found

    Ectoparasites of Bats in Mongolia (Ischnopsyllidae, Nycteribiidae, Cimicidae and Spinturnicidae)

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    For large parts of the world, the knowledge of bat ectoparasites is still scanty. Regarding Mongolia, only few studies exist to date. This paper analyzes results from extensive captures between 2005-2008, carried out in different sites of Mongolia. Discussed ectoparasites include bat fleas, (Ischnopsyllidae), bat flies (Nycteribiidae), and bat bugs (Cimicidae) and spinturnicid mites (Spinturnicidae). A number of species found in this study were new records for Mongolia, and for many species additional sites were reported. For some bat species, the spectrum and frequency of larger ectoparasites could be determined for the first time

    Ectoparasites of Bats in Mongolia (Ischnopsyllidae, Nycteribiidae, Cimicidae and Spinturnicidae)

    Get PDF
    For large parts of the world, the knowledge of bat ectoparasites is still scanty. Regarding Mongolia, only few studies exist to date. This paper analyzes results from extensive captures between 2005 -2008, carried out in different sites of Mongolia. Discussed ectoparasites include bat fleas, (Ischnopsyllidae), bat flies (Nycteribiidae), and bat bugs (Cimicidae) and spinturnicid mites (Spinturnicidae). A number of species found in this study were new records for Mongolia, and for many species additional sites were reported. For some bat species, the spectrum and frequency of larger ectoparasites could be determined for the first time

    The Solid-on-Solid Surface Width Around the Roughening Transition

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    We investigate the surface width WW of solid-on-solid surfaces in the vicinity of the roughening temperature TrT_r. Above TrT_r, W2W^2 is expected to diverge with the system size LL like ln⁡L\ln L. However, close to TrT_r a clean ln⁡L\ln{L} behavior can only be seen on extremely large lattices. Starting from the Kosterlitz-Thouless renormalization group, we derive an improved formula that describes the small LL behavior on both sides of TrT_r. For the Discrete Gaussian model, we used the valleys-to-mountains-reflections cluster algorithm in order to simulate the fluctuating solid-on-solid surface. The base plane above which the surface is defined is an L×LL \times L square lattice. In the simulation we took 8≤L≤2568\leq L\leq 256. The improved formula fits the numerical results very well. {}From the analysis, we estimate the roughening temperature to be Tr=0.755(3)T_r = 0.755(3).Comment: 9 pages, LaTeX (no figures), FSU-SCRI-93-67, CERN-TH.6893/9

    Pareto Optimal Matchings in Many-to-Many Markets with Ties

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    We consider Pareto-optimal matchings (POMs) in a many-to-many market of applicants and courses where applicants have preferences, which may include ties, over individual courses and lexicographic preferences over sets of courses. Since this is the most general setting examined so far in the literature, our work unifies and generalizes several known results. Specifically, we characterize POMs and introduce the \emph{Generalized Serial Dictatorship Mechanism with Ties (GSDT)} that effectively handles ties via properties of network flows. We show that GSDT can generate all POMs using different priority orderings over the applicants, but it satisfies truthfulness only for certain such orderings. This shortcoming is not specific to our mechanism; we show that any mechanism generating all POMs in our setting is prone to strategic manipulation. This is in contrast to the one-to-one case (with or without ties), for which truthful mechanisms generating all POMs do exist

    The College Admissions problem with lower and common quotas

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    We study two generalised stable matching problems motivated by the current matching scheme used in the higher education sector in Hungary. The first problem is an extension of the College Admissions problem in which the colleges have lower quotas as well as the normal upper quotas. Here, we show that a stable matching may not exist and we prove that the problem of determining whether one does is NP-complete in general. The second problem is a different extension in which, as usual, individual colleges have upper quotas, but, in addition, certain bounded subsets of colleges have common quotas smaller than the sum of their individual quotas. Again, we show that a stable matching may not exist and the related decision problem is NP-complete. On the other hand, we prove that, when the bounded sets form a nested set system, a stable matching can be found by generalising, in non-trivial ways, both the applicant-oriented and college-oriented versions of the classical Gale–Shapley algorithm. Finally, we present an alternative view of this nested case using the concept of choice functions, and with the aid of a matroid model we establish some interesting structural results for this case

    Stable isotope ratios of nitrogen and carbon as biomarkers of a vegan diet

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    Purpose Dietary biomarkers can potentially overcome the limitations of self-reported dietary data. While in ecology and archaeology, stable isotope ratios of carbon and nitrogen are widely used as biomarkers, this is not the case in nutrition research. Since the abundance of the 13C and the 15N isotope differ in food sources from plant and animal origin, stable isotope ratios of carbon and nitrogen (δ13C and δ15N) may differ in human biological material. Here, we investigated the stable isotope ratios of nitrogen and carbon in serum and urine from vegans and omnivores. Method Measurement of δ15N and δ13C in serum and 24 h urine was performed by Elemental Analyzer–Isotope Ratio Mass Spectrometer in the cross-sectional study “Risks and Benefits of a Vegan Diet”. The study included 36 vegans and 36 omnivores with a median age of 37.5 years (matched for age and sex), who adhered to their diet for at least 1 year. Results Both δ15N and δ13C were significantly lower in both the serum and 24 h urine of vegans compared to omnivores. δ15N either in serum or urine had 100% specificity and sensitivity to discriminate between vegans and omnivores. Specificity of δ13C was also > 90%, while sensitivity was 93% in serum and 77% in urine. Conclusion δ15N both in serum and urine was able to accurately identify vegans and thus appears to be a promising marker for dietary habits.publishedVersio

    Matching Dynamics with Constraints

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    We study uncoordinated matching markets with additional local constraints that capture, e.g., restricted information, visibility, or externalities in markets. Each agent is a node in a fixed matching network and strives to be matched to another agent. Each agent has a complete preference list over all other agents it can be matched with. However, depending on the constraints and the current state of the game, not all possible partners are available for matching at all times. For correlated preferences, we propose and study a general class of hedonic coalition formation games that we call coalition formation games with constraints. This class includes and extends many recently studied variants of stable matching, such as locally stable matching, socially stable matching, or friendship matching. Perhaps surprisingly, we show that all these variants are encompassed in a class of "consistent" instances that always allow a polynomial improvement sequence to a stable state. In addition, we show that for consistent instances there always exists a polynomial sequence to every reachable state. Our characterization is tight in the sense that we provide exponential lower bounds when each of the requirements for consistency is violated. We also analyze matching with uncorrelated preferences, where we obtain a larger variety of results. While socially stable matching always allows a polynomial sequence to a stable state, for other classes different additional assumptions are sufficient to guarantee the same results. For the problem of reaching a given stable state, we show NP-hardness in almost all considered classes of matching games.Comment: Conference Version in WINE 201
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