770 research outputs found
The Acute Effects of Moderate Intensity Aerobic Exercise on Short-Term Memory in College Students
Undergraduate
Applie
3D Immersive Visualization: Expanding Human Sensation
Unmet Need: The constant push for better and more interactive data visualization aids: the Oculus Rift replaced a two-dimensional fixed monitor with head tracking and a three-dimensional virtual space to explore; the Novint Falcon replaces two-dimensional pointing tools with a haptic sensor with force feedback and three degrees of axial freedom.
Deliverables: A demonstration of the technologies involved, in the form of an Oculus- and Falconenabled physical simulation of a room containing several objects that can be handled and manipulated in three dimensions.
Constraints: The hardware is expensive and difficult to acquire, and it requires a beefy computer to run.
Approach: We chose two exciting alternative human interface devices and put together a demo that shows off their capabilities for real-time input and feedback when used together.
Results: We realized our goal of a physical simulation on a smaller scale than we initially planned; technological limitations got in the way of us expanding it beyond what we have here.
Issues: The devices used here and the technologies they represent are still new and experimental; they are prohibitively expensive, and their software is unstable and resource intensive. In order for the technologies to be adopted widely, they will have to become more accessible, and a software infrastructure will have to be built around them.
Impact: Devices like these are poised to change the way we interact with computers and think about virtual space and data presentation. This project shows off just two, aiming to give the user an idea of the interactions that are possible.https://scholarscompass.vcu.edu/capstone/1104/thumbnail.jp
Parameter Sensitivity for In Vitro Anthrax Studies
Studies done on interactions between spores and macrophages done in vitro show inconsistent results based on experimental protocol and inhibit meaningful extrapolation to in vivo. In this study, we perform a sensitivity analysis of a model representing in vitro studies of interactions between anthrax spores and macrophages to help address the effects of these inconsistencies. We perform both local and global analyses using Latin hypercube sampling and partial rank correlation coefficients. Our analysis indicates the amount of intracellular bacteria over time is most sensitive to the killing of intracellular bacteria by the macrophages and replication of the bacteria inside the macrophage. Extracellular germination rates are shown to affect the amount of intracellular bacteria only during the incubation period, due to the assumption that any remaining extracellular bacteria is assumed to be washed away after the incubation period
Stretching beyond the Semester: Undergraduate Research, Ethnography of the University, and Proposals for Local Change
This article focuses on undergraduate research and mentoring through the lens of an âEthnography of the Universityâ course that engages students in writing and researching for local change. At our institution (Marquette University in Milwaukee, Wisconsin), âEthnography of the Universityâ is a writing-intensive English course in which students conduct semester-long, original, mixed-method research projects about some aspect of their undergraduate experience. Students move from asking questions of interest and importance to the campus community through stages of data collection and analysis and toward final reporting through multiple means: (1) article-length papers, (2) in-class presentations, and (3) research posters. Students present their final projectsâwith concrete proposals for changeâat a campus-wide research poster fair, which students ârunâ each semester by bringing food, arranging the room, and publicizing the event. When students seek publication and act on their proposed changes, their projects also stretch beyond a single semester: though they begin in the course, projects often develop into extracurricular pursuits, independent studies, or advocacy work. Our article describes how this happensâwith examples of student projects at the center of the pieceâand advocates for the course framework of âEthnography of the Universityââwith an argument for ethnographic writing research as part of undergraduate curricula across the disciplines
Recovering Ecosystem Functions in a Restored Salt Marsh by Leveraging Positive Effects of Biodiversity
Natural and managed ecosystems provide a variety of ecological, economic, and cultural benefits; yet most have been altered by human activity such that they exhibit deficits in both biodiversity and functionality. Identifying factors accelerating the recovery of key species and associated functions in degraded systems is therefore a global priority. We tested the hypotheses that explicitly incorporating biodiversity into restoration design will lead to greater ecosystem function and that positive effects of diversity will strengthen over time due to an increase in the importance of complementarity relative to selection effects. We did this by manipulating salt marsh plant species richness across a tidal elevation gradient as part of a coastal wetland restoration project in southern California. Overall, diversity enhanced biomass accumulation in experimental plots, with the magnitude of the effect strengthening from one to three years post-restoration due to a combination of decreasing performance in monocultures and increasing performance in multispecies mixtures over time. Positive diversity effects were initially due exclusively to selection, as mixtures were dominated by species also exhibiting high performance in monoculture, although the identity of the highest performing species varied across tidal elevations and over time. By the end of the study, complementarity, indicative of niche partitioning and/or positive interactions among species, contributed to productivity at least as much as selection effects. Our study provides real-world support for a recent theoretical model predicting strong positive biodiversity effects when functionally different species coexist in a heterogeneous landscape. Incorporating biodiversity into restoration designs can result in net gains in ecosystem function especially in low diversity systems, yet shorter experiments lacking broad environmental and species trait variability may both underestimate the strength of and misidentify the mechanisms underlying positive diversity effects
Witnessing Parental Violence and Cyber IPV Perpetration in Hispanic Emerging Adults: The Mediating Role of Attitudes Toward IPV
Recent studies indicate that the perpetration of intimate partner violence via cyberspaces (cyber IPV), namely, psychological aggression, sexual aggression, and cyberstalking is high among emerging adults. However, little is known of the risk factors that lead to cyber IPV and far lesser within Hispanic adults. Based on the intergenerational transmission of violence hypothesis, the present study examined the indirect effect of witnessing parental violence during childhood on the three types of cyber IPV through attitudes condoning IPV in Hispanic men and women, separately. Participants were 1,136 Hispanic emerging adults in the age range of 18-29 years (M = 20.53 years, SD = 2.42; 72.5% women, 88% Mexican descent). Over half of the participants (54.2%) witnessed at least one instance of parental violence during childhood. In contrast to women, men were more likely to hold attitudes accepting of IPV and perpetrate cyber sexual IPV, whereas women were more likely to report cyberstalking perpetration. Men and women with exposure to mother-to-father violence held attitudes justifying IPV that was associated with perpetrating the three cyber IPV types in adulthood (women: Brange = .016-.036; men: Brange = .016-.024). No significant gender differences were found in the associations of mother-to-father WPV and father-to-mother WPV on the three types of cyber IPV perpetration. These findings are discussed in the context of Hispanic culture, which has specific implications for cyber IPV intervention strategies
Finite-time Singularity Formation for Strong Solutions to the Euler Equations, I
In this paper and the companion paper [EJE2], we establish finite-time
singularity formation for finite-energy strong solutions to the axi-symmetric
Euler equations in the domain for some . In the spirit of our previous works, [EJSI] and
[EJB], we do this by first studying scale-invariant solutions which satisfy a
one dimensional PDE system and proving that they may become singular in finite
time for properly chosen initial data. We then prove local well-posedness for
the Euler equations in a natural regularity class which includes
scale-invariant solutions. While these solutions have uniformly bounded
vorticity from time zero until right before the blow-up time, they do not have
finite energy. To remedy this, we cut off the scale-invariant data to ensure
finite energy and prove that the corresponding local solution must also become
singular in finite time. This paper focuses only on the analysis of the
scale-invariant solutions themselves and the proof that they can become
singular in finite time. The local well-posedness theorem and the cut-off
argument are very close to those in [JSI] and [EJB] and are left for the
companion paper [EJE2].
It is important to remark that while the fluid domain is the exterior of a
cone, we prove global regularity for the axi-symmetric Euler equations
without swirl in the exact same regularity classes and in the same domain. It
is quite possible that the methods we use can be adapted to establish
finite-time singularity formation for finite-energy solutions to the
Euler equations on .Comment: There was a sign error in the version of the axi-symmetric Euler
equations that we have adopted. While Theorems A and D remain valid as
stated, it is unclear whether finite-time singularity formation results hold
for the systems with correct sign
Impact of Cardiorespiratory Fitness on Markers of Cardiovascular Disease in Professional Firefighters
Higher cardiorespiratory fitness (CRF) levels (VÌO2max) are associated with lower oxidative stress and inflammatory markers in addition to lower cardiovascular disease (CVD) risk; however, there are a lack of data examining this relationship among firefighters. CVD is the leading cause of mortality among firefighters and correlates with low CRF. PURPOSE: To examine differences in markers of CVD risk between firefighters classified as having either high or low levels of CRF. METHODS: Forty-six professional firefighters performed a maximal graded exercise test (GXT; Bruce Protocol), where VÌO2max was estimated from the Foster equation using time to exhaustion. Fasted blood samples were also taken to assess traditional and non-traditional biomarkers of CVD risk: HDL, LDL, glucose, cholesterol, triglycerides, advanced oxidation protein products (AOPP), homeostatic model assessment for insulin resistance (HOMA-IR) and C-reactive protein (CRP). Body fat percentage (BF%) was determined via Dual-Energy X-Ray Absorptiometry (DEXA),VÌO2max values were categorized based on American College of Sports Medicine (ACSM) guidelines to establish a high fitness group (n=19; VÌO2max = 44.7 ± 5.2 ml·kg-1·min-1; age = 35.94 ± 9.73 yrs; height = 178.86 ± 7.28 cm; waist circumference = 35.5 ± 2.73 cm; BF% = 19.9 ± 2.66) and a low fitness group (n=27; VÌO2max = 28.2 ± 4.9ml·kg-1·min-1; age = 38.5 ± 9.33 yrs; height = 179.21 ± 8.48 cm; waist circumference = 40.06 ± 4.29 cm; BF% = 27.2 ± 5.07). Non-parametric Mann-Whitney U tests were used to assess differences in CVD risk markers between the high and low fitness groups. Effect sizes were calculated as Cohenâs d (i.e., small [0.2-0.5], medium [0.5-0.8], large [\u3e 0.8]). RESULTS: Participants classified as high fitness had significantly (p \u3c 0.05) higher VÌO2max and HDL concentrations coupled with significantly lower BF%, cholesterol, triglycerides, LDL, insulin, HOMA-IR, CRP, and AOPP. Half of the observed differences demonstrated a medium effect size (LDL, insulin, HOMA-IR, CRP, and AOPP), while large effect sizes were noted for VÌO2max, BF%, cholesterol, triglycerides, HDL, LDL/HDL risk ratio. CONCLUSION: The high fitness group exhibited lower CVD risk levels and higher HDL levels compared to the low fitness group. Considering the results, firefighters are encouraged to maintain high CRF as well as lower BF% in an effort to reduce the risk of CVD and on-duty cardiac events
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