14,088 research outputs found

    On the distribution of proportions and ratios as indicators of ungulate body condition

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    In the wildlife literature various studies have shown that the amount of fat around the kidneys is often a good indicator of body condition and health of ungulate species ([1],[2]). Wildlife biologies often measure the weights of fat around the kidneys and the kidneys themselves (without fat), comparing these two quantities and transforming them into a ratio or a proportion as surrogates of body condition of dead animals. Later, they use these indices as response variables to model the e®ect of covariates or treatments, such as age group and season of the year, on body condition. The more commonly used models are ANOVA-type. Most debate has been concentrated on whether or not to use a simple ANOVA model of ratios or proportions with ¯xed e®ects, or an ANCOVA model using fat weight as response variable, and the kidneys weight as a covariate ([3]). Results have taken by surprise some biologists because using one or another model with both response variables could lead to very di®erent results for what it considered the most important e®ects. In this manuscript we attempt to highlight the main di®erences and the distributional properties of these response variables, ratio and proportion

    Patent collateral, investor commitment, and the market for venture lending

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    This paper investigates the market for lending to technology startups (i.e., venture lending) and examines two mechanisms that may facilitate trade within it: (1) the ‘salability’ of patent collateral; and (2) the credible commitment of existing equity investors. We find that intensified trading in the secondary patent market is strongly related to the annual rate of startup lending, particularly for startups with more redeployable patent assets. Moreover, we show that the credibility of venture capitalist commitments to reinvest in their startups’ next round of financing can be critical for startup debt provision. Utilizing the crash of 2000 as a severe and unexpected capital supply shock for VCs, we show that lenders continue to finance startups with recently funded investors better able to credibly commit to refinance their portfolio companies, but withdraw from otherwise-promising projects that may have needed their funds the most. The findings are consistent with predictions of incomplete contracting and financial intermediation theory.Accepted manuscrip

    Comparing alignment factors in SMEs and large organizations: a planning integration perspective

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    Measurement of the alignment between business strategies and information systems (IS) has demonstrated positive impact for the organizational performance. The factors that have proved relevant when assessing the maturity level of alignment are: communication, competency/value measurement, governance, partnership, architecture & scope, and skills. Existing research, however, has focused on the assessment of these factors on large organizations and has barely explored their impact on Small and Medium Enterprises (SME). This paper uses the data provided by 127 participants from large and SMEs in order to identify whether the aforementioned factors are also relevant for assessing the level of alignment maturity in SMEs. The results from this research suggest that there are not significant differences between large organizations and SMEs when assessing those factors. In addition, this research also explored the relation between different planning integration of alignment (independent, sequential and simultaneous) in order to measure the perceived relevance of the factors. The results suggest that the planning integration identified on SMEs and large organizations has a positive correlation on how these factors are ranked. For both SMEs and large organizations where the formulation is simultaneous, the relevance of the factors is higher perceived than it is for those where the formulation is independent or sequential

    The role of magnetoplasmons in Casimir force calculations

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    In this paper we review the role of magneto plasmon polaritons in the Casimir force calculations. By applying an external constant magnetic field a strong optical anisotropy is induced on two parallel slabs reducing the reflectivity and thus the Casimir force. As the external magnetic field increases, the Casimir force decreases. Thus, with an an external magnetic field the Casimir force can be controlled.The calculations are done in the Voigt configuration where the magnetic field is parallel to the slabs. In this configuration the reflection coefficients for TE and TM modes do not show mode conversion.Comment: contribution to QFEXT09, Norman, Oklahoma 200

    Bayesian Implications of Current LHC Supersymmetry and Dark Matter Detection Searches for the Constrained MSSM

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    We investigate the impact of recent limits from LHC searches for supersymmetry and from direct and indirect searches for dark matter on global Bayesian inferences of the parameter space of the Constrained Minimal Supersymmetric Standard Model (CMSSM). In particular we apply recent exclusion limits from the CMS \alpha_T analysis of 1.1/fb of integrated luminosity, the current direct detection dark matter limit from XENON100, as well as recent experimental constraints on \gamma-ray fluxes from dwarf spheroidal satellite galaxies of the Milky Way from the FermiLAT telescope, in addition to updating values for other non-LHC experimental constraints. We extend the range of scanned parameters to include a significant fraction of the focus point/hyperbolic branch region. While we confirm earlier conclusions that at present LHC limits provide the strongest constraints on the model's parameters, we also find that when the uncertainties are not treated in an excessively conservative way, the new bounds from dwarf spheroidal have the power to significantly constrain the focus point/hyperbolic branch region. Their effect is then comparable, if not stronger, to that from XENON100. We further analyze the effects of one-year projected sensitivities on the neutrino flux from the Sun in the 86-string IceCube+DeepCore configuration at the South Pole. We show that data on neutrinos from the Sun, expected for the next few months at IceCube and DeepCore, have the potential to further constrain the same region of parameter space independently of the LHC and can yield additional investigating power for the model.Comment: 27 pages, 7 figures, version published in PR

    How was the Hubble sequence 6 Gyrs ago?

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    The way galaxies assemble their mass to form the well-defined Hubble sequence is amongst the most debated topic in modern cosmology. One difficulty is to link distant galaxies to those at present epoch. We aim at establishing how were the galaxies of the Hubble sequence, 6 Gyrs ago. We intend to derive a past Hubble sequence that can be causally linked to the present-day one. We selected samples of nearby galaxies from the SDSS and of distant galaxies from the GOODS survey. We verified that each sample is representative of galaxies. We further showed that the observational conditions necessary to retrieve their morphological classification are similar in an unbiased way. Morphological analysis has been done in an identical way for all galaxies in the two samples. We found an absence of number evolution for elliptical and lenticular galaxies, which strikingly contrasts with the strong evolution of spiral and peculiar galaxies. Spiral galaxies were 2.3 times less abundant in the past, that is exactly compensated by the strong decrease by a factor 5 of peculiar galaxies. It strongly suggests that more than half of the present-day spirals had peculiar morphologies, 6 Gyrs ago, and this has to be accounted by any scenario of galactic disk evolution and formation. The past Hubble sequence can be used to test these scenarios as well as to test evolution of fundamental planes for spirals and bulges.Comment: Version accepted by Astronomy and Astrophysics, October 21 2009. Including low resolution images. 11 pages, 8 figure

    Towards wafer scale inductive determination of magnetostatic and dynamic parameters of magnetic thin films and multilayers

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    We investigate an inductive probe head suitable for non-invasive characterization of the magnetostatic and dynamic parameters of magnetic thin films and multilayers on the wafer scale. The probe is based on a planar waveguide with rearward high frequency connectors that can be brought in close contact to the wafer surface. Inductive characterization of the magnetic material is carried out by vector network analyzer ferromagnetic resonance. Analysis of the field dispersion of the resonance allows the determination of key material parameters such as the saturation magnetization MS or the effective damping parameter Meff. Three waveguide designs are tested. The broadband frequency response is characterized and the suitability for inductive determination of MS and Meff is compared. Integration of such probes in a wafer prober could in the future allow wafer scale in-line testing of magnetostatic and dynamic key material parameters of magnetic thin films and multilayers

    The visual binary AG Tri in β\beta Pictoris Association: can a debris disc cause very different rotation periods of its components?

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    We measure the photometric rotation periods of the components of multiple systems in young stellar associations to investigate the causes of the observed rotation period dispersion. We present the case of the wide binary AG Tri in the 23-Myr young beta Pictoris Association consisting of K4 + M1 dwarfs. Our multi-band, multi-season photometric monitoring allowed us to measure the rotation periods of both components P_A = 12.4d and P_B = 4.66d, to detect a prominent magnetic activity in the photosphere, likely responsible for the measured radial velocity variations, and for the first time, a flare event on the M1 component AG Tri B. We investigate either the possibility that the faster rotating component may have suffered an enhanced primordial disc dispersal, starting its PMS spin-up earlier than the slower rotating component, or the possibility that the formation of a debris disc may have prevented AG Tri A from gaining part of the angular momentum from the accreting disc.Comment: 28 pages, 7 figures, accepted for publication in Astrophysics and Space Science 2015, (ASTR-D-15-00445R2
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