463 research outputs found
Legislation - Foreign Relations - International Trade Reauthorization for the Overseas Private Investment Corporation
A Deconstruction of Horror, Fear and Terror: Using Horror Films as Didactic Tools in Art Education
This arts-based study discusses using the horror film and monsters as a means of exploring the personification of fear in contemporary society. The paper incorporates the viewing and dissection of horror films into an artistic process to explore fears in order to further artistic expression. It additionally shows how this process can be used in an art classroom within the context of contemporary art to empower students and facilitate art criticism discussions
IMPROVING NEAR SURFACE REFRACTIVITY ESTIMATES IN MARINE ENVIRONMENTS
This study utilizes in-situ measurements and numerical weather prediction datasets collected during the Coupled Air-Sea Processes Electromagnetic Ducting Research East field campaign to assess how thermodynamic properties in the marine atmospheric surface layer influence evaporation duct shape and to develop a simple near-surface modified refractivity estimation method. This study utilizes a logarithmic linear parametric model, which describes evaporation ducts via three main parameters: evaporation duct height, evaporation duct curvature, and mixed layer slope. Notably, most studies utilizing this type of model assume the curvature, C0, to be a theoretical value derived assuming neutral atmospheric stability; a thermodynamic regime that is rarely observed precisely. Prior studies suggest varying C0 to represent a wider range of ED shapes. Unfortunately, the physical significance of C0 is poorly understood so this approach is not commonly adopted. This study investigates relationships between C0 and near surface thermodynamic properties. The relationship between C0 and the air-sea temperature difference (ASTD) reveal, during unstable periods, that C0 are generally greater than in near-neutral or stable environments. C0 in near-neutral environments are generally close to the theoretical value. The linear relationship between the near surface specific humidity gradient (NSSHG) and C0 is stronger than that with ASTD thus, it is concluded that C0 variations are primarily driven by NSSHG. Modified refractivity profiles are modeled using C0 based on a NSSHG empirical linear model (termed, EDS model) and compared to other common methods of near surface estimation such as Monin-Obukhov similarity theory (MOST) and extrapolation from ~3m to the surface. Refractivity estimated from the EDS model was similar to in-situ refractivity measurements. Linearly or non-linearly (i.e., polynomials) extrapolating refractivity to the surface resulted in closer agreement between measured and modeled propagation loss, indicating that measured data better predicted PL than either model. Notably, the EDS model predicted PL that is statistically similar to that predicted by MOST implying this novel empirical method is a practical alternative to MOST in applications such as propagation modeling and requires significantly less environmental measurements
Parallelism in Flower Evolution and Development
Posted with permission from the Annual Review of Ecology, Evolution, and Systematics, v.51. Copyright by Annual Reviews, http://www.annualreviews.orgFlower evolution is characterized by widespread repetition, with adaptations to pollinator environment evolving in parallel. Recent studies have expanded our understanding of the developmental basis of adaptive floral noveltiesâpetal fusion, bilateral symmetry, heterostyly, and floral dimensions. In this article, we describe patterns of trait evolution and review developmental genetic mechanisms underlying floral novelties. We discuss the diversity of mechanisms for parallel adaptation, the evidence for constraints on these mechanisms, and how constraints help explain observed macroevolutionary patterns. We describe parallel evolution resulting from similarities at multiple hierarchical levelsâgenetic, developmental, morphological, functionalâwhich indicate general principles in floral evolution, including the central role of hormone signaling. An emerging pattern is mutational bias that may contribute to rapid patterns of parallel evolution, especially if the derived trait can result from simple degenerative mutations. We argue that such mutational bias may be less likely to govern the evolution of novelties patterned by complex developmental pathways
Selfing Can Facilitate Transitions between Pollination Syndromes
Pollinator-mediated selection on plants can favor transitions to a new pollinator depending on the relative abundances and efficiencies of pollinators present in the community. A frequently observed example is the transition from bee pollination to hummingbird pollination. We present a population genetic model that examines whether the ability to inbreed can influence evolutionary change in traits that underlie pollinator attraction. We find that a transition to a more efficient but less abundant pollinator is favored under a broadened set of ecological conditions if plants are capable of delayed selfing rather than obligately outcrossing. Delayed selfing allows plants carrying an allele that attracts the novel pollinator to reproduce even when this pollinator is rare, providing reproductive assurance. In addition, delayed selfing weakens the effects of Haldaneâs sieve by increasing the fixation probability for recessive alleles that confer adaptation to the new pollinator. Our model provides novel insight into the paradoxical abundance of recessive mutations in adaptation to hummingbird attraction. It further predicts that transitions to efficient but less abundant pollinators (such as hummingbirds in certain communities) should disproportionately occur in self-compatible lineages. Currently available mating system data sets are consistent with this prediction, and we suggest future areas of research that will enable a rigorous test of this theory.National Institutes of Health (F32 GM 110988-3)National Institutes of Health (R01 GM073990-02)National Science Foundation (DEB-1542402
Readersâ Advisory in the Public Library: A Look at the Promotion of Diverse Literature to Teens
Teens are reading, and libraries are helping teens read. One way that libraries are helping teens read is through readersâ advisory, the recommendation of books to readers for the purpose of pleasure reading. In the library field, there is a recognition of the need for diverse literature and its positive impacts. This study investigates the perspectives of librarians and library staff on readersâ advisory, with special attention to the promotion of diverse literature. Interview data and document analysis showed that librarians are performing readersâ advisory often, and teens are taking advantages of the different advisory opportunities provided by the libraries. The librarians view diverse literature as valuable and do promote it, though none cited promoting diverse literature as a guiding principle in readersâ advisory.Master of Science in Library Scienc
Effect of Huperzine A on Cognitive Function and Perception of Effort during Exercise: A Randomized Double-Blind Crossover Trial
International Journal of Exercise Science 14(2): 727-741, 2021. Huperzine A has shown the ability to acutely improve cognitive function in certain populations, and therefore is commonly added to pre-workout supplements. However, its effects have not been studied in exercise-trained individuals. OBJECTIVE: We hypothesized that acute consumption of huperzine A would improve cognitive function during exercise, which may be beneficial for exercise performance. METHODS: From January to April, 2018, 15 exercise-trained individuals (11 women [height 166 ± 2 cm, weight 60.5 ± 3.0 kg] and 4 men [height 173 ± 4 cm, weight 82.0 ± 11.0 kg], BMI 23.5 ± 1.4 kg/m2, age 30.4 ± 3.6 years) were studied in a double blind randomized-sequence cross-over study, in which they underwent tests for cognitive function (digit span, verbal/word fluency, and Stroop), neuromuscular performance (sharpened Romberg and dart throwing), and exercise performance (estimated aerobic capacity, hand-grip strength, vertical jump, and push-up) after acute ingestion of huperzine A (200 mcg) or placebo. One week separated the two trials. RESULTS: No measures of cognitive function differed between placebo and huperzine A trials (all p ℠0.296). Heart rates (157 ± 4 vs. 158 ± 4 bpm; p = 0.518) and ratings of perceived exertion (13.7 ± 0.56 vs. 13.9 ± 0.61; p = 0.582) did not differ between placebo and huperzine A trials, respectively. Ratings of subjective difficulty post-exercise (0-10 scale) were significantly higher (5.7 ± 0.38 vs. 6.8 ± 0.38; p = 0.002) in the huperzine A trial than the placebo trial. No differences were observed for neuromuscular or exercise performance measures between groups (all p ℠0.497). CONCLUSIONS: Huperzine A does not enhance cognitive function during exercise despite it being marketed as a cognitive enhancer. Because of its inability to enhance cognitive function, its inclusion in pre-workout supplements warrants reconsideration. Other more practical and effective strategies should be considered
Identifying powerful project stakeholders using workflow, communication and friendship social networks
The social networks of IT projects are examined to determine whether powerful stakeholders are identifiable by their centrality in the communication, workflow and friendship networks. Traditional stakeholder models rely on the abilities of the project manager to correctly attribute certain characteristics to stakeholders and thereby determine who is powerful or important to the project. The purpose of the research is to provide an initial network-based stakeholder model that can be used to identify stakeholders by their social interactions in project teams.Stakeholder interactions and power ratings are collected from project team members that are part of three IT projects using social network tools and the resultant sociomatrices analysed to produce centrality measures for each stakeholder. The power ratings consisted of positional, personal and political power variables which were then entered into a regression analysis with nine centrality measures for degree, closeness and betweenness centrality. Overall, the results provided evidence that powerful stakeholders could be determined by their centrality in the various network types. Stakeholders with high personal power can be identified using the communications network. Those with high positional power can be identified using the workflow network and those with high political power can be identified using the friendship network.Dissertation (MBA)--University of Pretoria, 2012.Gordon Institute of Business Science (GIBS)unrestricte
Paradigms for Clinical fMRI
This unit presents description of four basic clinical paradigms for clinical fMRI of language cmprehension, eye movement (visually guidede saccades), motor cortex (fingerâthumb apposition), and visual cortex. Given the neurosurgical concern with preservation of eloquent cortex, brain functions of particular interest are primary sensory (e.g., visual, auditory) and motor functions, and high level processing of language comprehension and expression. Compromise of these functions is usually readily apparent clinically and the quality of life of the patient is severely diminished. Functional MRI offers a means to locate these functions, thereby allowing the surgeon to plan on preserving these functions, or prepare the patient appropriately.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145259/1/cpmia0603.pd
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