140 research outputs found
Historical legacies, competition and dispersal control patterns of invasion by a non-native grass, Microstegium vimineum Trin. (A. Camus)
No full textBiological invasions can be controlled by a number of factors, and the importance of these factors for individual species can change depending on the spatial scale under consideration. Furthermore, the long-term legacies of past land use may be among the major factors structuring contemporary communities. This study was designed to merge these two lines of thought by observing the processes influencing invasion success of an exotic grass species, Microstegium vimineum. Plots within twenty hardwood forest stands of different ages (40 years old to [greater than] 100 years) were surveyed in central New Jersey for the presence and abundance of this species, and the data was analyzed using simple, multiple linear and logistic regressions, as well as regression trees. At the stand scale, M. vimineum abundance was influenced by age, slope, shrub cover and forest connectivity, with far more predictable responses in younger stands than in old. On the plot scale, forest age and prior use were again the dominant influences on abundance of the invasive. Invasion in old forests was most promoted by thinner canopy cover, while younger stands were most influenced by soil type and distance to forest edge. Further studies along dispersal corridors (streams and trails) in these stands consistently showed more invasion in younger stands than older, but also found the intensity of invasion to be higher along such corridors than through areas without them. Observation of isolated patches confirmed that seed dispersal is mostly short-range without dispersal conduits, with most seeds germinating less than a meter from their parent patch boundaries. Finally, an experimental study of the role of understory shrub cover and litter depth on seed germination and seedling growth showed that shade from shrubs strongly limits survival and growth. Seeds also need to be in contact with mineral soil to establish, but otherwise litter depth does not influence growth. These studies demonstrate that the establishment and spread of this invasive species is affected by complex hierarchies of factors that differ in stands with different land use histories. Land managers can use these differences to design targeted control programs that are more effective and stand-specific.Ph.D.Includes bibliographical references (p. 148-159)
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Oriental enlightenment: the problematic military experiences and cultural claims of Count Maurice Auguste comte de Benyowsky in Formosa during 1771
No full textMaurice Benyowsky's colourful version of his global adventures during the heady, expansive days of the late-Enlightenment remains still as an historical account, and is perhaps destined for reification at a time of romantic, postmodernist cultural affirmation. Yet this paper argues that within it there lies a virile and possibly dangerous Orientalism, one at least partially based upon a lurid, opportunistic and self-seeking fabrication of his visit to Taiwan (Formosa) in the year 1771. This paper examines the veracity, provenance and historiography of the Benyowsky account of late-eighteenth century Formosa, both as an exercise in one facet of Taiwanese history and as some exploration of the origin and maintenance of European views of the "other" and of the "orient" as they were transforming during the late-Enlightenment period. Furthermore a principal task is to provide an historiographical analysis that illustrates both the initial reasons for the acceptance of Benyowsky's lurid account as well as the wider contexts of its long life as a seemingly reliable and authentic tale. Questions remain as to the cultural contexts of any general acceptance of otherwise doubtful stories, experiments, claims and "adventures". Here there is little doubt that the original Memoirs were given greater credence by Benyowsky's talent in self-fashioning his character and status as those of a reliable gentleman
Steady-state modulation of voltage-gated K+ channels in rat arterial smooth muscle by cyclic AMP-dependent protein kinase and protein phosphatase 2B
No full textVoltage-gated potassium channels (Kv) are important regulators of membrane potential in vascular smooth muscle cells, which is integral to controlling intracellular Ca2+ concentration and regulating vascular tone. Previous work indicates that Kv channels can be modulated by receptor-driven alterations of cyclic AMP-dependent protein kinase (PKA) activity. Here, we demonstrate that Kv channel activity is maintained by tonic activity of PKA. Whole-cell recording was used to assess the effect of manipulating PKA signalling on Kv and ATP-dependent K+ channels of rat mesenteric artery smooth muscle cells. Application of PKA inhibitors, KT5720 or H89, caused a significant inhibition of Kv currents. Tonic PKA-mediated activation of Kv appears maximal as application of isoprenaline (a β-adrenoceptor agonist) or dibutyryl-cAMP failed to enhance Kv currents. We also show that this modulation of Kv by PKA can be reversed by protein phosphatase 2B/calcineurin (PP2B). PKA-dependent inhibition of Kv by KT5720 can be abrogated by pre-treatment with the PP2B inhibitor cyclosporin A, or inclusion of a PP2B auto-inhibitory peptide in the pipette solution. Finally, we demonstrate that tonic PKA-mediated modulation of Kv requires intact caveolae. Pre-treatment of the cells with methyl-β-cyclodextrin to deplete cellular cholesterol, or adding caveolin-scaffolding domain peptide to the pipette solution to disrupt caveolae-dependent signalling each attenuated PKA-mediated modulation of the Kv current. These findings highlight a novel, caveolae-dependent, tonic modulatory role of PKA on Kv channels providing new insight into mechanisms and the potential for pharmacological manipulation of vascular tone
Re-Visioning Reality: Quantum Superposition in Visual Art
No full textThe counterintuitive phenomenon of quantum superposition requires a radical review of our ideas of reality. The author suggests that translations of quantum concepts into visual art may assist in provoking such a revision. This essay first introduces the concept of quantum superposition and points out its divergence from conventional perceptions of reality. The author then discusses how visual art might provide insight into quantum superposition. Finally she discusses the visual representation of quantum superposition by contemporary artists Jonathon Keats, Julian Voss-Andreae, Antony Gormley and Daniel Crooks; the problematic and paradoxical nature of such representations; and how these works might provoke a revision of our views of physical reality.Arts, Education & Law Group, Queensland College of ArtFull Tex
Public health workforce survey data (2016–2021) related to employee turnover: proposed methods for harmonization and triangulation
No full textIntroduction: Public health workforce numbers are unsustainable at best and dire at worst: based on 2017 and 2019 data, 80,000 FTEs needed to be hired by health departments to provide basic public health foundational services before COVID-19 hit, suggesting that the situation is worse after the mass exodus of public health officials due to the pandemic. As such, a better understanding of public health workforce turnover is critical to improving recruitment and retention in the discipline.
Methods: This methods report details how the authors harmonized four public health workforce surveys—the Public Health Workforce Interests and Needs Survey (PH WINS), the National Association of County and City Health Officials (NACCHO) Profile, the NACCHO Forces of Change survey, and the Association of State and Territorial Health Officials (ASTHO) Profile—in order to examine employee turnover.
Results: We found that 31% of the public health workforce reported considering leaving their positions at some time in the future. Furthermore, the majority of agencies reported that zero vacancies had been filled in both 2018 and 2019.
Discussion: These findings suggest that retention, recruitment, and onboarding may be areas upon which to focus evaluation and quality improvement endeavors, allowing public health organizations to better attract and retain the most qualified candidates.The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This project was supported by the Centers for Diseases Control and Prevention and the Health Resources and Services Administration under awards U81HP47167 and UR2HP47371 (total amount $1,121,814). This information or content and conclusions are those of the author and should not be construed as the official position or policy of, nor should any endorsements be inferred by CDC, HRSA, HHS or the U.S. Government.Weiss, Nicole M.; Martin, Skky; Onal, Sezen O.; McDaniel, Nicole; Leider, Jonathon P.. (2024). Public health workforce survey data (2016–2021) related to employee turnover: proposed methods for harmonization and triangulation. Retrieved from the University Digital Conservancy, 10.3389/fpubh.2023.1306274
105 - Alex M Fout
No full textIncludes bibliographical references.This poster was presented at the 2017 Colorado State University Graduate Student Showcase, 9 November 2017.Determining the interface between two interacting proteins can help illuminate cellular biology, improve our understanding of disease, and aid pharmaceutical research. Such determination is expensive and time consuming using wet-lab experiments, which has motivated the development of computational methods. Inspired by the success of deep learning in image processing and other application areas, we adapt convolutional neural networks to work with irregularly structured data, such as proteins. We construct a novel pairwise classification architecture which is trained and tested with data from the Docking Benchmark Dataset versions 4.0 and 5.0. This outperforms the existing state-of-the-art prediction method, PAIRpred.Graduate Student Council - New Graduate Student - Research Top Scholar
G protein-coupled receptor kinase 6 (GRK6) selectively regulates endogenous secretin receptor responsiveness in NG108-15 cells
No full textG protein-coupled receptor kinase 2 is essential to enable vasoconstrictor-mediated arterial smooth muscle proliferation
No full textHypertension is associated with increased production and circulation of vasoconstrictors, resulting in enhanced signalling through their cognate G protein-coupled receptors (GPCR). Prolonged vasoconstrictor GPCR signalling increases arterial contraction and stimulates signalling pathways that promote vascular smooth muscle cell (VSMC) proliferation, contributing to the development of atherosclerotic plaques, re-stenosis lesions and vascular remodelling. GPCR signalling through phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) promotes VSMC proliferation. In VSMC, G protein-coupled receptor kinase 2 (GRK2) is known to regulate numerous vasoconstrictor GPCRs and their downstream signalling pathways. As GRK2 is implicated in controlling various aspects of cellular growth, we examined whether GRK2 could affect VSMC proliferation. Using two indices of cell growth, we show that PI3K inhibition and depletion of GRK2 expression produced a similar ablation of pro-proliferative vasoconstrictor-stimulated VSMC growth. Furthermore, GRK2-knockdown ablated the sustained phase of endothelin-1 and angiotensin-II-stimulated Akt phosphorylation, whilst the peak (5 min) phase was unaffected. Conversely, the GRK2 inhibitor compound 101 did not affect vasoconstrictor-driven Akt phosphorylation. Vasoconstrictor-stimulated phosphorylation of the Akt substrates GSK3α and GSK3β was ablated following RNAi-mediated GRK2 depletion, or after PI3K inhibition. Moreover, GRK2 knockdown prevented endothelin-1 and angiotensin-II from increasing cyclin D1 expression. These data suggest GRK2 expression is essential to facilitate vasoconstrictor-driven VSMC proliferation through its ability to promote efficient prolonged PI3K-Akt signalling, and thus relieve the GSK3-mediated block on cell cycling. Considering VSMC GRK2 expression increases early in the development of hypertension, this highlights the potential for GRK2 to promote VSMC growth and exacerbate hypertensive pathophysiological vascular remodelling
WHO BENEFITS FROM MICROFINANCE? THE IMPACT EVALUATION OF LARGE SCALE PROGRAMS IN BANGLADESH
No full textThis paper evaluates the impact of microfinance on household consumption using a new, large and unique cross-section data set from Bangladesh. The richness of the data and program eligibility criterion allow the use of a number of non-experimental impact evaluation techniques, in particular instrumental variable (IV) estimation and propensity score matching (PSM). Estimates from both IV and PSM strategies have been interpreted as average causal effects that are valid for various groups of participants in microfinance. The overall results indicate that the effects of micro loans are not robust across all groups of poor household borrowers. It appears that the poorest of the poor participants are among those who benefit most. The impact estimates are lower, or sometimes even negative, for those households marginal to the participation decision. The effects of participation are, in general, stronger for male borrowers. These results hold across different specifications and methods, including correction for various sources of selection bias (including possible spill-over effects).Microfinance, treatment effect, Matching, Consumption.
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