Mortality rates of the Alpine Chamois : the influence of snow-meteorological factors

Especially for animals inhabiting alpine areas, winter environmental conditions can be limiting. Cold temperatures, hampered food availability and natural perils are just three of many potential threats that mountain ungulates face in winter. Understanding their sensitivity to climate variability is essential for game management. Here we focus on analyzing the influence of snow and weather conditions on the mortality pattern of Alpine chamois. Our mortality data are derived from a systematic assessment of 6,500 chamois that died of natural causes over the course of 13 years. We use population- and habitat-specific data on snow, climate and avalanche danger to identify the key environmental factors that essentially determine the spatio-temporal variations in chamois mortality. Initially, we show that most fatalities occurred in winter, with a peak around March, when typically snow depths were highest. Death causes related to poor general conditions were the major component of seasonal variations. As for the interannual variations in mortality, snow depth and avalanche risk best explained the occurrence of winters with increased numbers of fatalities. Finally, analyzing differences in mortality rates between populations, we identified sun-exposed winter habitats with little snow accumulation as favourable for alpine chamois

Deep Convolutional Neural Networks as strong gravitational lens detectors

Future large-scale surveys with high resolution imaging will provide us with a few $10^5$ new strong galaxy-scale lenses. These strong lensing systems however will be contained in large data amounts which are beyond the capacity of human experts to visually classify in a unbiased way. We present a new strong gravitational lens finder based on convolutional neural networks (CNNs). The method was applied to the Strong Lensing challenge organised by the Bologna Lens Factory. It achieved first and third place respectively on the space-based data-set and the ground-based data-set. The goal was to find a fully automated lens finder for ground-based and space-based surveys which minimizes human inspect. We compare the results of our CNN architecture and three new variations ("invariant" "views" and "residual") on the simulated data of the challenge. Each method has been trained separately 5 times on 17 000 simulated images, cross-validated using 3 000 images and then applied to a 100 000 image test set. We used two different metrics for evaluation, the area under the receiver operating characteristic curve (AUC) score and the recall with no false positive ($\mathrm{Recall}_{\mathrm{0FP}}$). For ground based data our best method achieved an AUC score of $0.977$ and a $\mathrm{Recall}_{\mathrm{0FP}}$ of $0.50$. For space-based data our best method achieved an AUC score of $0.940$ and a $\mathrm{Recall}_{\mathrm{0FP}}$ of $0.32$. On space-based data adding dihedral invariance to the CNN architecture diminished the overall score but achieved a higher no contamination recall. We found that using committees of 5 CNNs produce the best recall at zero contamination and consistenly score better AUC than a single CNN. We found that for every variation of our CNN lensfinder, we achieve AUC scores close to $1$ within $6\%$.Comment: 9 pages, accepted to A&

Parton cascade description of relativistic heavy-ion collisions at CERN SPS energies ?

We examine Pb+Pb collisions at CERN SPS energy 158 A GeV, by employing the earlier developed and recently refined parton-cascade/cluster-hadronization model and its Monte Carlo implementation. This space-time model involves the dynamical interplay of perturbative QCD parton production and evolution, with non-perturbative parton-cluster formation and hadron production through cluster decays. Using computer simulations, we are able to follow the entwined time-evolution of parton and hadron degrees of freedom in both position and momentum space, from the instant of nuclear overlap to the final yield of particles. We present and discuss results for the multiplicity distributions, which agree well with the measured data from the CERN SPS, including those for K mesons. The transverse momentum distributions of the produced hadrons are also found to be in good agreement with the preliminary data measured by the NA49 and the WA98 collaboration for the collision of lead nuclei at the CERN SPS. The analysis of the time evolution of transverse energy deposited in the collision zone and the energy density suggests an existence of partonic matter for a time of more than 5 fm.Comment: 16 pages including 7 postscript figure

A New Field of Dreams: A Study of the Writing Major

Within Writing Studies, the tension between pedagogy and theory, between teaching and disciplinary status receives much commentary. This dissertation explores that tension within the context of the undergraduate Writing major. I begin by reviewing scholarship about advanced composition, advanced Writing, and the Writing major. I read this literature in light of concerns about student subjectivity, authorship, and disciplinary participation. Through that reading, I explore the conflicted status of the student subject imagined within this literature. The subject I discern contains elements of what Susan Miller describes as the normative subject of composition as well as elements of a revised and politically astute Writing Studies. In chapter two, I demonstrate how these elements also appeared in the discourse of students who participated in the two-institution study of undergraduate Writing majors upon which the remaining chapters of this dissertation are based. In chapter three, I argue that when students articulated the work of the Writing major, they privileged relational, affective labor in ways that may potentially affirm arguments for the Writing major as a vehicle for disciplinarity as well as assert pedagogy\u27s continued importance within Writing Studies even as its practitioners pursue academic professionalization. Chapter four examines students\u27 discourse and their writing for scholarly, professional, and civic purposes in order to demonstrate how students contribute to-- and participate in--goals widely held within Writing Studies through academic, creative, and creative nonfiction forms. In the fifth and concluding chapter, I consider the implications of this research for scholarly writing practice and for writing pedagogy. I also acknowledge the limitations of this current project and outline an agenda for future research. Ultimately, this dissertation encourages a broad understanding of students\u27 disciplinary contribution and participation

“Weaving all of them together”: How Writing Majors Talk about Creative Writing

The labels “creative” and “creative writing” serve several purposes in the discourses of undergraduate writing majors. In a study of students in two writing major programs, students often exerted significant effort to negotiate among diverse writing experiences and to integrate different understandings of writing. Their efforts mirror scholars’ conversations about negotiation and integration at the level of curricula and programs. Writing majors in this study raised issues relevant to the well-established curricular domains of theoretical knowledge, professional expertise, and civic action. They explained their insights using a mix of idiosyncratic, institutional, and disciplinary language that frequently relied on forms of “’not’ talk” (Reiff and Bawarshi). One term around which much of their blended-language and ‘not’ talk centered was “creative.” Students used the label “creative” to mean writing fiction and poetry, personal expression, creative nonfiction prose, nonacademic discourse, and flexibility in style and genre. Frequently, these uses were mixed together or slipped casually from one to another. These findings suggest that as students engage with disciplinary purposes for writing in the major, they draw from a range of literacy discourses to negotiate among and to integrate diverse forms of knowledge

Heavy resonance production in high energy nuclear collisions

We estimate freezeout conditions for $s$, $c$, and $b$ quarks in high energy nuclear collisions. Freezeout is due either to loss of thermal contact, or to particles ``wandering'' out of the region of hot matter. We then develop a thermal recombination model in which both single-particle (quark and antiquark) and two-particle (quark-antiquark) densities are conserved. Conservation of two-particle densities is necessary because quarks and antiquarks are always produced in coincidence, so that the local two-particle density can be much larger than the product of the single-particle densities. We use the freezeout conditions and recombination model to discuss heavy resonance production at zero baryon density in high energy nuclear collisions.Comment: revtex, 15 pages, no figures, KSUCNR-009-9

Thermal quark production in ultra-relativistic nuclear collisions

We calculate thermal production of u, d, s, c and b quarks in ultra-relativistic heavy ion collisions. The following processes are taken into account: thermal gluon decay (g to ibar i), gluon fusion (g g to ibar i), and quark-antiquark annihilation (jbar j to ibar i), where i and j represent quark species. We use the thermal quark masses, $m_i^2(T)\simeq m_i^2 + (2g^2/9)T^2$, in all the rates. At small mass ($m_i(T)<2T$), the production is largely dominated by the thermal gluon decay channel. We obtain numerical and analytic solutions of one-dimensional hydrodynamic expansion of an initially pure glue plasma. Our results show that even in a quite optimistic scenario, all quarks are far from chemical equilibrium throughout the expansion. Thermal production of light quarks (u, d and s) is nearly independent of species. Heavy quark (c and b) production is quite independent of the transition temperature and could serve as a very good probe of the initial temperature. Thermal quark production measurements could also be used to determine the gluon damping rate, or equivalently the magnetic mass.Comment: 14 pages (latex) plus 6 figures (uuencoded postscript files); CERN-TH.7038/9

Sub-gap spectroscopy of thermally excited quasiparticles in a Nb contacted carbon nanotube quantum dot

We present electronic transport measurements of a single wall carbon nanotube quantum dot coupled to Nb superconducting contacts. For temperatures comparable to the superconducting gap peculiar transport features are observed inside the Coulomb blockade and superconducting energy gap regions. The observed temperature dependence can be explained in terms of sequential tunneling processes involving thermally excited quasiparticles. In particular, these new channels give rise to two unusual conductance peaks at zero bias in the vicinity of the charge degeneracy point and allow to determine the degeneracy of the ground states involved in transport. The measurements are in good agreement with model calculations.Comment: 5 pages, 4 figure

Examining the Personal and Institutional Determinants of Research Productivity in Hospitality and Tourism Management

The transition toward a post-capitalist knowledge-oriented economy has resulted in an increasingly competitive academic environment, where the success of faculty is dependent on their research productivity. This study examines the personal and institutional determinants of the quantity and quality of the research productivity of hospitality and tourism management faculty in US institutions. A survey of 98 faculty found that a different set of determinants impact the quantity and quality aspects of research productivity. Also, institutional determinants were found to play a larger role, indicating the need for administrators to strive for a culture that is supportive of and an infrastructure that is conducive to their faculty’s research success. The authors use the field of hospitality and tourism management as a case study to develop a holistic and cohesive framework for knowledge worker productivity that can guide the evaluation, hiring, and development of researchers