Visual and Olfactory Concealment of Duck Nests: Influence on Nest Site Selection and Success

Selecting a nest site is an important decision for waterfowl. Because most nest failure is due to depredation, the primary selective pressure in choosing a nest site should be to reduce depredation risk. This task is difficult, however, because predators use differing tactics to locate nests, such as olfactory or visual cues. The purpose of this research was to evaluate both the olfactory and visual components of waterfowl nest site selection and nest depredation in North Dakota. We located waterfowl nests, monitored them until termination (hatched or depredated), and collected both visual and olfactory concealment characteristics of nest sites and paired random sites in 2006 and 2007. Waterfowl nest sites and random sites did not differ in their olfactory concealment characteristics. However, waterfowl did select nesting sites with greater lateral concealment than random sites, a visual characteristic. The only difference found between successful and depredated nests consisted of lateral dispersion, an olfactory concealment characteristic. These results indicate that while waterfowl may select nest sites based on visual concealment characteristics, those characteristics were not predictive of nest success. Olfactory concealment characteristics may be more important for nest success in our study area because the dominant nest predators, including raccoons (Procyon lotor) and striped skunks (Mephitis mephitis), primarily utilize olfactory cues to locate nest sites

Towards a Conceptualization of Sociomaterial Entanglement

In knowledge representation, socio-technical systems can be modeled as multiagent systems in which the local knowledge of each individual agent can be seen as a context. In this paper we propose formal ontologies as a means to describe the assumptions driving the construction of contexts as local theories and to enable interoperability among them. In particular, we present two alternative conceptualizations of the notion of sociomateriality (and entanglement), which is central in the recent debates on socio-technical systems in the social sciences, namely critical and agential realism. We thus start by providing a model of entanglement according to the critical realist view, representing it as a property of objects that are essentially dependent on different modules of an already given ontology. We refine then our treatment by proposing a taxonomy of sociomaterial entanglements that distinguishes between ontological and epistemological entanglement. In the final section, we discuss the second perspective, which is more challenging form the point of view of knowledge representation, and we show that the very distinction of information into modules can be at least in principle built out of the assumption of an entangled reality

Reification and Truthmaking Patterns

Reification is a standard technique in conceptual modeling, which consists of including in the domain of discourse entities that may otherwise be hidden or implicit. However, deciding what should be rei- fied is not always easy. Recent work on formal ontology offers us a simple answer: put in the domain of discourse those entities that are responsible for the (alleged) truth of our propositions. These are called truthmakers. Re-visiting previous work, we propose in this paper a systematic analysis of truthmaking patterns for properties and relations based on the ontolog- ical nature of their truthmakers. Truthmaking patterns will be presented as generalization of reification patterns, accounting for the fact that, in some cases, we do not reify a property or a relationship directly, but we rather reify its truthmakers

Greater Sage-Grouse Select Nest Sites to Avoid Visual Predators but Not Olfactory Predators

Birds can hide from visual predators by locating nests where there is cover and from olfactory predators where habitat features create updrafts, high winds, and atmospheric turbulence, but sites optimal for hiding from visual and olfactory predators often differ. We examined how Greater Sage-Grouse (Centrocercus urophasianus) balance the dual needs of hiding from both visual and olfactory predators on Parker Mountain, Utah, where the Common Raven (Corvus corax) is the main visual predator and the striped skunk (Mephitis mephitis) and American badger (Taxidea taxus) are the main olfactory predators. By comparing nest sites to random sites during 2005 and 2006, we found that sage-grouse nest at sites where their nests were obscured from visual predators but were exposed to olfactory predators. To validate these findings, we replicated the study in southwest Wyoming during 2008. Again, we found that visual obscurity at nest sites was greater than at control sites but olfactory obscurity was less. Our results indicate that Greater Sage-Grouse select nest sites where they will be concealed from visual predators but at the cost of locating nests where they are exposed to olfactory predators. In southwest Wyoming, we found that olfactory predators (mammals) and visual predators (birds) depredated an equal number of nests. By selecting nest sites with visual obscurity, Greater Sage-Grouse have reduced the threat from visual predators to where it was similar to the threat posed by olfactory predators

Caenorhabditis elegans glp-4 encodes a valyl aminoacyl tRNA synthetase

Germline stem cell proliferation is necessary to populate the germline with sufficient numbers of cells for gametogenesis and for signaling the soma to control organismal properties such as aging. The Caenorhabditis elegans gene glp-4 was identified by the temperature-sensitive allele bn2 where mutants raised at the restrictive temperature produce adults that are essentially germ cell deficient, containing only a small number of stem cells arrested in the mitotic cycle but otherwise have a morphologically normal soma. We determined that glp-4 encodes a valyl aminoacyl transfer RNA synthetase (VARS-2) and that the probable null phenotype is early larval lethality. Phenotypic analysis indicates glp-4(bn2ts) is partial loss of function in the soma. Structural modeling suggests that bn2 Gly296Asp results in partial loss of function by a novel mechanism: aspartate 296 in the editing pocket induces inappropriate deacylation of correctly charged Val-tRNA(val). Intragenic suppressor mutations are predicted to displace aspartate 296 so that it is less able to catalyze inappropriate deacylation. Thus glp-4(bn2ts) likely causes reduced protein translation due to decreased levels of Val-tRNA(val). The germline, as a reproductive preservation mechanism during unfavorable conditions, signals the soma for organismal aging, stress and pathogen resistance. glp-4(bn2ts) mutants are widely used to generate germline deficient mutants for organismal studies, under the assumption that the soma is unaffected. As reduced translation has also been demonstrated to alter organismal properties, it is unclear whether changes in aging, stress resistance, etc. observed in glp-4(bn2ts) mutants are the result of germline deficiency or reduced translation

Visualizing Natural Image Statistics

Natural image statistics is an important area of research in cognitive sciences and computer vision. Visualization of statistical results can help identify clusters and anomalies as well as analyze deviation, distribution and correlation. Furthermore, they can provide visual abstractions and symbolism for categorized data. In this paper, we begin our study of visualization of image statistics by considering visual representations of power spectra, which are commonly used to visualize different categories of images. We show that they convey a limited amount of statistical information about image categories and their support for analytical tasks is ineffective. We then introduce several new visual representations, which convey different or more information about image statistics. We apply ANOVA to the image statistics to help select statistically more meaningful measurements in our design process. A task-based user evaluation was carried out to compare the new visual representations with the conventional power spectra plots. Based on the results of the evaluation, we made further improvement of visualizations by introducing composite visual representations of image statistics

A Survey of GPU-Based Large-Scale Volume Visualization

This survey gives an overview of the current state of the art in GPU techniques for interactive large-scale volume visualization. Modern techniques in this field have brought about a sea change in how interactive visualization and analysis of giga-, tera-, and petabytes of volume data can be enabled on GPUs. In addition to combining the parallel processing power of GPUs with out-of-core methods and data streaming, a major enabler for interactivity is making both the computational and the visualization effort proportional to the amount and resolution of data that is actually visible on screen, i.e., “output-sensitive” algorithms and system designs. This leads to recent outputsensitive approaches that are “ray-guided,” “visualization-driven,” or “display-aware.” In this survey, we focus on these characteristics and propose a new categorization of GPU-based large-scale volume visualization techniques based on the notions of actual output-resolution visibility and the current working set of volume bricks—the current subset of data that is minimally required to produce an output image of the desired display resolution. For our purposes here, we view parallel (distributed) visualization using clusters as an orthogonal set of techniques that we do not discuss in detail but that can be used in conjunction with what we discuss in this survey.Engineering and Applied Science

The effect of timing and composition of gestational weight gain in obese pregnant women on infant birth weight: A prospective cohort study.

Introduction: CK2 is a protein kinase implicated in several essential cellular processes, over-expressed in cancer and described to regulate insulin signaling cascade. Recently CK2 has been described to negatively regulate thermogenesis (Shinoda K et al, 2015, Cell Metabolism) and to inhibit insulin release (Rossi M et al, 2015, PNAS). Nevertheless, the role of CK2 in adipose tissue (AT) and its involvement in human obesity development and therapy has been poorly investigated. Methods: Our multi-disciplinary team performed biochemical analysis of signaling pathways by WB and in vitro kinase activity assays, and glucose handling studies using glucose uptake assay and IF in adipocyte cultures and glucose and insulin tolerance test in mice. Moreover we quantify CK2 expression/activity in human AT specimens of 27 obese patients, clinically characterized, in 12 obese patients underwent relevant weight loss and 11 normal-weight controls. Results: We proved that CK2 amount and activity were not influenced by insulin stimulation and that CK2 activity was efficiently inhibited by specific inhibitors, structurally unrelated. We worked with CX-4945, a CK2 inhibitor currently used in cancer clinical trials, using the minimal concentration (2.5 \u192 dM) and pre-treatment time (1hr) able to efficiently inhibit CK2 activity, avoiding any cytotoxic effect. Pharmacological inhibition of CK2 did not significantly affect in vitro adipogenic differentiation or expression profiling of mature adipocytes. Conversely, we showed that in human and murine adipocytes CK2-inhibition decreases the insulin-induced glucose uptake by counteracting Akt-signaling and GLUT4-translocation to the plasma membrane. We compared CK2 expression and activity in different mouse tissues highlighted that white skeletal muscle fibres and liver contained the highest quantity of this kinase. CK2 was expressed more in brown AT than in white AT depots. We show that CK2 promotes insulin-signaling in mouse AT, liver and skeletal muscle and that in vivo acute treatment with CX-4945 impairs glucose- tolerance in mice. Studies in tissues of ob/ob and db/db mice highlights an up-regulation of CK2 expression and activity only in WAT. CK2 hyper-activation is strongly evident also in SAT and VAT of obese patients and weight loss obtained by bariatric surgery or hypocaloric diet reverts CK2 up-regulation to normal level. Conclusion: We show that CK2 is involved in insulin sensitivity, glucose handling and remodeling of WAT. Moreover we identify CK2 hyper-activation as a hallmark of human obesity, suggesting a new potential therapeutic target for metabolic diseases