112 research outputs found

    Statistics of surface divergence and their relation to air-water gas transfer velocity

    Get PDF
    Air-sea gas fluxes are generally defined in terms of the air/water concentration difference of the gas and the gas transfer velocity,kL. Because it is difficult to measure kLin the ocean, it is often parameterized using more easily measured physical properties. Surface divergence theory suggests that infrared (IR) images of the water surface, which contain information concerning the movement of water very near the air-water interface, might be used to estimatekL. Therefore, a series of experiments testing whether IR imagery could provide a convenient means for estimating the surface divergence applicable to air-sea exchange were conducted in a synthetic jet array tank embedded in a wind tunnel. Gas transfer velocities were measured as a function of wind stress and mechanically generated turbulence; laser-induced fluorescence was used to measure the concentration of carbon dioxide in the top 300 μm of the water surface; IR imagery was used to measure the spatial and temporal distribution of the aqueous skin temperature; and particle image velocimetry was used to measure turbulence at a depth of 1 cm below the air-water interface. It is shown that an estimate of the surface divergence for both wind-shear driven turbulence and mechanically generated turbulence can be derived from the surface skin temperature. The estimates derived from the IR images are compared to velocity field divergences measured by the PIV and to independent estimates of the divergence made using the laser-induced fluorescence data. Divergence is shown to scale withkLvalues measured using gaseous tracers as predicted by conceptual models for both wind-driven and mechanically generated turbulence

    A unique therapeutic approach to emesis and itch with a proanthocyanidin-rich genonutrient

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>We examined the therapeutic potential of a proprietary <it>Croton palanostigma </it>extract (Zangrado<sup>®</sup>) in the management of emesis and itch.</p> <p>Methods</p> <p>Emesis was induced in ferrets with morphine-6-glucuronide (0.05 mg/kg sc) in the presence of Zangrado (3 mg/kg, ip) and the cannabinoid receptor 1 antagonist, AM 251 (5 mg/kg, ip). Topical Zangrado (1%) was assessed for anti-pruretic actions in the 5-HT-induced scratching model in rats and evaluated in capsaicin-induced gastric hyperemia as measured by laser doppler flow. In the <it>Apc</it><sup><it>Min</it></sup>mouse model of precancerous adenomatosis polyposis, mice received Zangrado (100 μg/ml in drinking water) from the age of 6 – 16 weeks for effects on polyp number. In RAW 264.7 cells Zangrado was examined for effects on lipopolysaccharide-induced nitrite production.</p> <p>Results</p> <p>Zangrado was a highly effective anti-emetic, reducing morphine-induced vomiting and retching by 77%. These benefits were not associated with sedation or hypothermia and were not reversed by cannabinoid receptor antagonism. Itch responses were blocked in both the morphine and 5-HT models. Zangrado did not exacerbate the <it>Apc</it><sup><it>Min</it></sup>condition rather health was improved. Capsaicin-induced hyperemia was blocked by Zangrado, which also attenuated the production of nitric oxide by activated macrophages.</p> <p>Conclusion</p> <p>Zangrado is an effective anti-emetic and anti-itch therapy that is devoid of common side-effects, cannabinoid-independent and broadly suppresses sensory afferent nerve activation. This complementary medicine represents a promising new approach to the management of nausea, itch and irritable bowel syndrome.</p

    New Horned Dinosaurs from Utah Provide Evidence for Intracontinental Dinosaur Endemism

    Get PDF
    Background:\ud During much of the Late Cretaceous, a shallow, epeiric sea divided North America into eastern and western landmasses. The western landmass, known as Laramidia, although diminutive in size, witnessed a major evolutionary radiation of dinosaurs. Other than hadrosaurs (duck-billed dinosaurs), the most common dinosaurs were ceratopsids (large-bodied horned dinosaurs), currently known only from Laramidia and Asia. Remarkably, previous studies have postulated the occurrence of latitudinally arrayed dinosaur “provinces,” or “biomes,” on Laramidia. Yet this hypothesis has been challenged on multiple fronts and has remained poorly tested.\ud \ud Methodology/Principal Findings:\ud Here we describe two new, co-occurring ceratopsids from the Upper Cretaceous Kaiparowits Formation of Utah that provide the strongest support to date for the dinosaur provincialism hypothesis. Both pertain to the clade of ceratopsids known as Chasmosaurinae, dramatically increasing representation of this group from the southern portion of the Western Interior Basin of North America. Utahceratops gettyi gen. et sp. nov.—characterized by short, rounded, laterally projecting supraorbital horncores and an elongate frill with a deep median embayment—is recovered as the sister taxon to Pentaceratops sternbergii from the late Campanian of New Mexico. Kosmoceratops richardsoni gen. et sp. nov.—characterized by elongate, laterally projecting supraorbital horncores and a short, broad frill adorned with ten well developed hooks—has the most ornate skull of any known dinosaur and is closely allied to Chasmosaurus irvinensis from the late Campanian of Alberta.\ud \ud Conclusions/Significance:\ud Considered in unison, the phylogenetic, stratigraphic, and biogeographic evidence documents distinct, co-occurring chasmosaurine taxa north and south on the diminutive landmass of Laramidia. The famous Triceratops and all other, more nested chasmosaurines are postulated as descendants of forms previously restricted to the southern portion of Laramidia. Results further suggest the presence of latitudinally arrayed evolutionary centers of endemism within chasmosaurine ceratopsids during the late Campanian, the first documented occurrence of intracontinental endemism within dinosaurs

    Diverse perspectives on interdisciplinarity from the Members of the College of the Royal Society of Canada

    Get PDF
    Various multiple-disciplinary terms and concepts (although most commonly “interdisciplinarity”, which is used herein) are used to frame education, scholarship, research, and interactions within and outside academia. In principle, the premise of interdisciplinarity may appear to have many strengths; yet, the extent to which interdisciplinarity is embraced by the current generation of academics, the benefits and risks for doing so, and the barriers and facilitators to achieving interdisciplinarity represent inherent challenges. Much has been written on the topic of interdisciplinarity, but to our knowledge there have been few attempts to consider and present diverse perspectives from scholars, artists, and scientists in a cohesive manner. As a team of 57 members from the Canadian College of New Scholars, Artists, and Scientists of the Royal Society of Canada (the College) who self-identify as being engaged or interested in interdisciplinarity, we provide diverse intellectual, cultural, and social perspectives. The goal of this paper is to share our collective wisdom on this topic with the broader community and to stimulate discourse and debate on the merits and challenges associated with interdisciplinarity. Perhaps the clearest message emerging from this exercise is that working across established boundaries of scholarly communities is rewarding, necessary, and is more likely to result in impact. However, there are barriers that limit the ease with which this can occur (e.g., lack of institutional structures and funding to facilitate cross-disciplinary exploration). Occasionally, there can be significant risk associated with doing interdisciplinary work (e.g., lack of adequate measurement or recognition of work by disciplinary peers). Solving many of the world’s complex and pressing problems (e.g., climate change, sustainable agriculture, the burden of chronic disease, and aging populations) demand thinking and working across long-standing, but in some ways restrictive, academic boundaries. Academic institutions and key support structures, especially funding bodies, will play an important role in helping to realize what is readily apparent to all who contributed to this paper—that interdisciplinarity is essential for solving complex problems; it is the new norm. Failure to empower and encourage those doing this research will serve as a great impediment to training, knowledge, and addressing societal issues

    Physiological Correlates of Volunteering

    Get PDF
    We review research on physiological correlates of volunteering, a neglected but promising research field. Some of these correlates seem to be causal factors influencing volunteering. Volunteers tend to have better physical health, both self-reported and expert-assessed, better mental health, and perform better on cognitive tasks. Research thus far has rarely examined neurological, neurochemical, hormonal, and genetic correlates of volunteering to any significant extent, especially controlling for other factors as potential confounds. Evolutionary theory and behavioral genetic research suggest the importance of such physiological factors in humans. Basically, many aspects of social relationships and social activities have effects on health (e.g., Newman and Roberts 2013; Uchino 2004), as the widely used biopsychosocial (BPS) model suggests (Institute of Medicine 2001). Studies of formal volunteering (FV), charitable giving, and altruistic behavior suggest that physiological characteristics are related to volunteering, including specific genes (such as oxytocin receptor [OXTR] genes, Arginine vasopressin receptor [AVPR] genes, dopamine D4 receptor [DRD4] genes, and 5-HTTLPR). We recommend that future research on physiological factors be extended to non-Western populations, focusing specifically on volunteering, and differentiating between different forms and types of volunteering and civic participation

    A new Basal sauropodomorph dinosaur from the Lower Jurassic Navajo sandstone of Southern Utah.

    Get PDF
    BACKGROUND: Basal sauropodomorphs, or 'prosauropods,' are a globally widespread paraphyletic assemblage of terrestrial herbivorous dinosaurs from the Late Triassic and Early Jurassic. In contrast to several other landmasses, the North American record of sauropodomorphs during this time interval remains sparse, limited to Early Jurassic occurrences of a single well-known taxon from eastern North America and several fragmentary specimens from western North America. METHODOLOGY/PRINCIPAL FINDINGS: On the basis of a partial skeleton, we describe here a new basal sauropodomorph dinosaur from the Lower Jurassic Navajo Sandstone of southern Utah, Seitaad ruessi gen. et sp. nov. The partially articulated skeleton of Seitaad was likely buried post-mortem in the base of a collapsed dune foreset. The new taxon is characterized by a plate-like medial process of the scapula, a prominent proximal expansion of the deltopectoral crest of the humerus, a strongly inclined distal articular surface of the radius, and a proximally and laterally hypertrophied proximal metacarpal I. CONCLUSIONS/SIGNIFICANCE: Phylogenetic analysis recovers Seitaad as a derived basal sauropodomorph closely related to plateosaurid or massospondylid 'prosauropods' and its presence in western North America is not unexpected for a member of this highly cosmopolitan clade. This occurrence represents one of the most complete vertebrate body fossil specimens yet recovered from the Navajo Sandstone and one of the few basal sauropodomorph taxa currently known from North America

    A new macrovertebrate assemblage from the late Cretaceous (Campanian) of Southern Utah

    No full text
    [Extract] For most of the late Cretaceous, a shallow epeiric sea subdivided North America into eastern and western landmasses - Appalachia and Laramiclia, respectively. Whereas little is known of Appalachian faunas, Laramidia has yielded an abundant terrestrial fossil record, arguably the best continent-scale example for any Mesozoic time interval. To date, however, the bulk of these fossils have been recovered from the northern portion of Laramidia, in particular Alberta and Montana. The relatively poor fossil record from southern Laramidia has limited our ability to test several key biogeographic and evolutionary hypotheses.\ud \ud In 2000, the Utah Museum of Natural History (now the Natural History Museum of Utah), University of Utah, launched an interdisciplinary project in Grand Staircase-Escalante National Monument aimed at exploring Late Cretaceous terrestrial and freshwater ecosystems preserved within the Kaiparowits Basin. Although emphasis has been placed on collection and study of macrovertebrates, from the outset the "Kaiparowits Basin Project" has targeted a spectrum of data sources, spanning sedimentology, stratigraphy, paleobotany, and ichnology, as well as vertebrate and invertebrate paleontology. This large-scale, interdisciplinary effort has thus far concentrated on two Campanian-aged geologic formations, the Kaiparowits and Wahweap, with spectacular results that include a previously unknown assemblage of dinosaurs and other macrovertebrates. Turtles, crocodylians, and dinosaurs all exhibit relatively high species diversity, with many endemic taxa. The fossiliferous Kaiparowits Formation alone has yielded remains of 14 turtle taxa, six crocodylian taxa, and l6 dinosaur taxa, with evidence that these communities inhabited a wet, largely swampy environment with vegetation ranging from cypress trees (lowest elevation) to dicot forests (better-drained settings) to forests of taxodiaceolls and other gymnosperms (well-drained settings). These and other finds are stratigraphically constrained by multiple radiometric dates, allowing robust comparisons with coeval northern vertebrate assemblages. Considered in unison, five distinct lines of evidence- taxonomy, phylogeny, stratigraphy, paleoenvironment, and biogeography - provide strong support for the vertebrate provincialism hypothesis, which postulates the occurrence of latitudinally arrayed biotic "provinces" on Laramidia for at least a portion of the Late Cretaceous. Paleontologically, the Kaiparowits Formation has now been established as the best-known Campanian unit from southern Laramidia, exceeded in the north only by the Dinosaur Park Formation of Alberta
    corecore