Destination Areas (DAs)
Permanent URI for this community
Destination Areas provide faculty and students with new tools to identify and solve complex, 21st-century problems in which Virginia Tech already has significant strengths and can take a global leadership role. The initiative represents the next step in the evolution of the land-grant university to meet economic and societal needs of the world. DAs connect the full span of relevant knowledge necessary for addressing issues comprehensively. Humanistic, scientific, and technological perspectives are addressed in relationship to one another and they are treated as complementary to overcome traditional academic boundaries, such as those that separate the STEM fields and liberal arts. [http://provost.vt.edu/destination-areas.html]
Browse
Browsing Destination Areas (DAs) by Issue Date
Now showing 1 - 20 of 1371
Results Per Page
Sort Options
- Public, animal, and environmental health implications of aquacultureGarrett, E. Spencer; dos Santos, Carlos Lima; Jahncke, Michael L. (1997-10)Aquaculture is important to the United States and the world's fishery system. Both import and export markets for aquaculture products will expand and increase as research begins to remove physiologic and other animal husbandry barriers. Overfishing of wild stock will necessitate supplementation and replenishment through aquaculture. The aquaculture industry must have a better understanding of the impact of the ''shrouded'' public and animal health issues: technology ignorance, abuse, and neglect. Cross-pollination and cross-training of public health and aquaculture personnel in the effect of public health, animal health, and environmental health on aquaculture are also needed. Future aquaculture development programs require an integrated Gestalt public health approach to ensure that aquaculture does not cause unacceptable risks to public or environmental health and negate the potential economic and nutritional benefits of aquaculture.
- Campylobacter jejuni - An emerging foodborne pathogenAltekruse, Sean Fitzgerald; Stern, N. J.; Fields, P. I.; Swerdlow, David L. (1999-01)Campylobacter jejuni is the most commonly reported bacterial cause of foodborne infection in the United States. Adding to the human and economic costs are chronic sequelae associated with C. jejuni infection-Guillain-Barre syndrome and reactive arthritis. In addition, an increasing proportion of human infections caused by C. jejuni are resistant to antimicrobial therapy. Mishandling of raw poultry and consumption of undercooked poultry are the major risk factors for human campylobacteriosis. Efforts to prevent human illness are needed throughout each link in the food chain.
- Choosing a Sustainable Future: SANREM CRSP 1999 Annual ReportCason, K. (ed.) (Watkinsville, Ga.: SANREM CRSP, 2000)This document describes the progress of the SANREM CRSP for the period June 1, 1999 to May 31, 2000.
- Dendritic Spikes and Their Influence on Extracellular Calcium SignalingWiest, Michael C.; Eagleman, David M.; King, Richard D.; Montague, P. Read (American Physiological Society, 2000)Extracellular calcium is critical for many neural functions, including neurotransmission, cell adhesion, and neural plasticity. Experiments have shown that normal neural activity is associated with changes in extracellular calcium, which has motivated recent computational work that employs such fluctuations in an information-bearing role. This possibility suggests that a new style of computing is taking place in the mammalian brain in addition to current ‘circuit’ models that use only neurons and connections. Previous computational models of rapid external calcium changes used only rough approximations of calcium channel dynamics to compute the expected calcium decrements in the extracellular space. Using realistic calcium channel models, experimentally measured back-propagating action potentials, and a model of the extracellular space, we computed the fluctuations in external calcium that accrue during neural activity. In this realistic setting, we showed that rapid, significant changes in local external calcium can occur when dendrites are invaded by back-propagating spikes, even in the presence of an extracellular calcium buffer. We further showed how different geometric arrangements of calcium channels or dendrites prolong or amplify these fluctuations. Finally, we computed the influence of experimentally measured synaptic input on peridendritic calcium fluctuations. Remarkably, appropriately timed synaptic input can amplify significantly the decrement in external calcium. The model shows that the extracellular space and the calcium channels that access it provide a medium that naturally integrates coincident spike activity from different dendrites that intersect the same tissue volume.
- From Landscapes to Waterscapes: A PSE for Landuse Change AnalysisRubin, E.J.; Diet, R.; Chanat, J.; Speir, C.; Dymond, Randel L.; Lohani, Vinod K.; Kibler, David F.; Bosch, D. D.; Shaffer, Clifford A.; Ramakrishnan, Naren; Watson, Layne T. (Department of Computer Science, Virginia Polytechnic Institute & State University, 2000)We describe the design and implementation of L2W — a problem solving environment (PSE) for landuse change analysis. L2W organizes and unifies the diverse collection of software typically associated with ecosystem models (hydrological, economic, and biological). It provides a web-based interface for potential watershed managers and other users to explore meaningful alternative land development and management scenarios and view their hydrological, ecological, and economic impacts. A prototype implementation for the Upper Roanoke River Watershed in Southwest Virginia, USA is described.
- Delayed Medical Care After Diagnosis in a US National Probability Sample of Persons Infected With Human Immunodeficiency VirusTurner, Barbara J.; Cunningham, William E.; Duan, Naihua; Andersen, Ronald M.; Shapiro, Martin F.; Bozzette, Samuel A.; Nakazono, Terry; Morton, Sally C.; Crystal, Steven; St. Clair, Patti; Stein, Michael; Zierler, Sally (AMA, 2000-09-25)Objective: To identify health care and patient factors associated with delayed initial medical care for human immunodeficiency virus (HIV) infection. Design: Survey of a national probability sample of persons with HIV in care. Setting: Medical practices in the contiguous United States. Patients: Cohort A (N = 1540) was diagnosed by February 1993 and was in care within 3 years; cohort B (N = 1960) was diagnosed by February 1995 and was in care within 1 year of diagnosis. Main Outcome Measure: More than 3- or 6-month delay. Results: Delay of more than 3 months occurred for 29% of cohort A (median, 1 year) and 17% of cohort B. Having a usual source of care at diagnosis reduced delay, with adjusted odds ratios (ORs) of 0.61 (95% confidence interval [CI], 0.48-0.77) in cohort A and 0.70 (95% CI, 0.50-0.99) in cohort B. Medicaid coverage at diagnosis showed lower adjusted ORs of delay compared with private insurance (cohort A: adjusted OR, 0.52; 95% CI, 0.30-0.92; cohort B: adjusted OR, 0.48; 95% CI, 0.27-0.85). Compared with whites, Latinos had 53% and 95% higher adjusted ORs of delay (P<.05) in cohorts A and B, respectively, and African Americans had a higher adjusted OR in cohort A (1.56; 95% CI, 1.19-2.04). The health care factors showed similar effects on delay of greater than 6 months. Conclusions: Medicaid insurance and a usual source of care were protective against delay after HIV diagnosis. After full adjustment, delay was still greater for Latinos and, to a lesser extent, African Americans compared with whites.
- Sustainable Use of Land and Resources: SANREM CRSP 2000 Annual ReportCason, K. (ed.) (Watkinsville, Ga.: SANREM CRSP, 2001)This document describes the progress of the SANREM CRSP for the period June 1, 2000 through May 31, 2001.
- Saving a river: Why do local governments matter?Rola, Agnes C.; Tabien, C. (College, Laguna, Philippines: University of the Philippines Los Baños. School of Environmental Science and Management, 2001)This paper evaluates the sufficiency and local implementation of river management laws in the Philippines. The assessment is that although there are enough policies and regulations, they are not adequately implemented at the local level because the LGUs do not have the necessary ordinances to implement national policies effectively. The authors suggest how market-based instruments to can be developed and implemented to improve river management, using a river in Lantapan, Bukidnon as a case study.
- Usability Evaluation in Virtual Environments: Classification and Comparison of MethodsBowman, Douglas A.; Gabbard, Joseph L.; Hix, Deborah (Department of Computer Science, Virginia Polytechnic Institute & State University, 2001)Virtual environments (VEs) are a relatively new type of human-computer interface in which users perceive and act in a three-dimensional world. The designers of such systems cannot rely solely on design guidelines for traditional two-dimensional interfaces, so usability evaluation is crucial for VEs. We present an overview of VE usability evaluation. First, we discuss some of the issues that differentiate VE usability evaluation from evaluation of traditional user interfaces such as GUIs. We also present a review of VE evaluation methods currently in use, and discuss a simple classification space for VE usability evaluation methods. This classification space provides a structured means for comparing evaluation methods according to three key characteristics: involvement of representative users, context of evaluation, and types of results produced. To illustrate these concepts, we compare two existing evaluation approaches: testbed evaluation [Bowman, Johnson, & Hodges, 1999], and sequential evaluation [Gabbard, Hix, & Swan, 1999]. We conclude by presenting novel ways to effectively link these two approaches to VE usability evaluation.
- Expenditures for the Care of HIV-Infected Patients in the Era of Highly Active Antiretroviral TherapyBozzette, Samuel A.; Joyce, Geoffrey; McCaffrey, Daniel F.; Leibowitz, Arleen A.; Morton, Sally C.; Berry, Sandra H.; Rastegar, Afshin; Timberlake, David; Shapiro, Martin F.; Goldman, Dana P. (NEJM Group, 2001-03-15)Background: The introduction of expensive but very effective antiviral medications has led to questions about the effects on the total use of resources for the care of patients with human immunodeficiency virus (HIV) infection. We examined expenditures for the care of HIV-infected patients since the introduction of highly active antiretroviral therapy. Methods: We interviewed a random sample of 2864 patients who were representative of all American adults receiving care for HIV infection in early 1996, and followed them for up to 36 months. We estimated the average expenditure per patient per month on the basis of self-reported information about care received. Results: The mean expenditure was $1,792 per patient per month at base line, but it declined to $1,359 for survivors in 1997, since the increases in pharmaceutical expenditures were smaller than the reductions in hospital costs. Use of highly active antiretroviral therapy was independently associated with a reduction in expenditures. After adjustments for the interview date, clinical status, and deaths, the estimated annual expenditure declined from $20,300 per patient in 1996 to $18,300 in 1998. Expenditures among subgroups of patients varied by a factor of as much as three. Pharmaceutical costs were lowest and hospital costs highest among underserved groups, including blacks, women, and patients without private insurance. Conclusions: The total cost of care for adults with HIV infection has declined since the introduction of highly active antiretroviral therapy. Expenditures have increased for medications but have declined for other services. However, there are large variations in expenditures across subgroups of patients. (N Engl J Med 2001;344:817-23.)
- LTD Induction in Adult Visual Cortex: Role of Stimulus Timing and InhibitionPerrett, Stephen P.; Dudek, Serena M.; Eagleman, David M.; Montague, P. Read; Friedlander, Michael J. (Society for Neuroscience, 2001-04-01)One Hertz stimulation of afferents for 15 min with constant interstimulus intervals (regular stimulation) can induce longterm depression (LTD) of synaptic strength in the neocortex. However, it is unknown whether natural patterns of lowfrequency afferent spike activity induce LTD. Although neurons in the neocortex can fire at overall rates as low as 1 Hz, the intervals between spikes are irregular. This irregular spike activity (and thus, presumably, irregular activation of the synapses of that neuron onto postsynaptic targets) can be approximated by stimulation with Poisson-distributed interstimulus intervals (Poisson stimulation). Therefore, if low-frequency presynaptic spike activity in the intact neocortex is sufficient to induce a generalized LTD of synaptic transmission, then Poisson stimulation, which mimics this spike activity, should induce LTD in slices. We tested this hypothesis by comparing changes in the strength of synapses onto layer 2/3 pyramidal cells induced by regular and Poisson stimulation in slices from adult visual cortex. We find that regular stimulation induces LTD of excitatory synaptic transmission as assessed by field potentials and intracellular postsynaptic potentials (PSPs) with inhibition absent. However, Poisson stimulation does not induce a net LTD of excitatory synaptic transmission. When the PSP contained an inhibitory component, neither Poisson nor regular stimulation induced LTD. We propose that the short bursts of synaptic activity that occur during a Poisson train have potentiating effects that offset the induction of LTD that is favored with regular stimulation. Thus, natural (i.e., irregular) low-frequency activity in the adult neocortex in vivo should not consistently induce LTD.
- Predictability Modulates Human Brain Response to RewardBerns, Gregory S.; McClure, Samuel M.; Pagnoni, Giuseppe; Montague, P. Read (Society for Neuroscience, 2001-04-15)Certain classes of stimuli, such as food and drugs, are highly effective in activating reward regions. We show in humans that activity in these regions can be modulated by the predictability of the sequenced delivery of two mildly pleasurable stimuli, orally delivered fruit juice and water. Using functional magnetic resonance imaging, the activity for rewarding stimuli in both the nucleus accumbens and medial orbitofrontal cortex was greatest when the stimuli were unpredictable. Moreover, the subjects’ stated preference for either juice or water was not directly correlated with activity in reward regions but instead was correlated with activity in sensorimotor cortex. For pleasurable stimuli, these findings suggest that predictability modulates the response of human reward regions, and subjective preference can be dissociated from this response.
- Use of Mental Health and Substance Abuse Treatment Services Among Adults With HIV in the United StatesBurnam, M. Audrey; Bing, Eric G.; Morton, Sally C.; Sherbourne, Cathy Donald; Fleishman, John A.; London, Andrew S.; Vitiello, Benedetto; Stein, Michael; Bozzette, Samuel A.; Shapiro, Martin F. (AMA, 2001-08)Background: The need for mental health and substance abuse services is great among those with human immunodeficiency virus (HIV), but little information is available on services used by this population or on individual factors associated with access to care. Methods: Data are from the HIV Cost and Services Utilization Study, a national probability survey of 2864 HIV-infected adults receiving medical care in the United States in 1996. We estimated 6-month use of services for mental health and substance abuse problems and examined socioeconomic, HIV illness, and regional factors associated with use. Results: We estimated that 61.4% of 231 400 adults under care for HIV used mental health or substance abuse services: 1.8% had hospitalizations, 3.4% received residential substance abuse treatment, 26.0% made individual mental health specialty visits, 15.2% had group mental health treatment, 40.3% discussed emotional problems with medical providers, 29.6% took psychotherapeutic medications, 5.6% received outpatient substance abuse treatment, and 12.4% participated in substance abuse self-help groups. Socioeconomic factors commonly associated with poorer access to health services predicted lower likelihood of using mental health outpatient care, but greater likelihood of receiving substance abuse treatment services. Those with less severe HIV illness were less likely to access services. Persons living in the Northeast were more likely to receive services. Conclusions: The magnitude of mental health and substance abuse care provided to those with known HIV infection is substantial, and challenges to providers should be recognized. Inequalities in access to care are evident, but differ among general medical, specialty mental health, and substance abuse treatment sectors.
- Psychiatric Disorders and Drug Use Among Human Immunodeficiency Virus–Infected Adults in the United StatesBing, Eric G.; Burnam, M. Audrey; Longshore, Douglas; Fleishman, John A.; Sherbourne, Cathy Donald; London, Andrew S.; Turner, Barbara J.; Eggan, Ferd; Beckman, Robin; Vitiello, Benedetto; Morton, Sally C.; Orlando, Maria; Bozzette, Samuel A.; Ortiz-Barron, Lucila; Shapiro, Martin F. (AMA, 2001-08)Background: There have been no previous nationally representative estimates of the prevalence of mental disorders and drug use among adults receiving care for human immunodeficiency virus (HIV) disease in the United States. It is also not known which clinical and sociodemographic factors are associated with these disorders. Subjects and Methods: We enrolled a nationally representative probability sample of 2864 adults receiving care for HIV in the United States in 1996. Participants were administered a brief structured psychiatric instrument that screened for psychiatric disorders (major depression, dysthymia, generalized anxiety disorders, and panic attacks) and drug use during the previous 12 months. Sociodemographic and clinical factors associated with screening positive for any psychiatric disorder and drug dependence were examined in multivariate logistic regression analyses. Results: Nearly half of the sample screened positive for a psychiatric disorder, nearly 40% reported using an illicit drug other than marijuana, and more than 12% screened positive for drug dependence during the previous 12 months. Factors independently associated with screening positive for a psychiatric disorder included number of HIV-related symptoms, illicit drug use, drug dependence, heavy alcohol use, and being unemployed or disabled. Factors independently associated with screening positive for drug dependence included having many HIV-related symptoms, being younger, being heterosexual, having frequent heavy alcohol use, and screening positive for a psychiatric disorder. Conclusions: Many people infected with HIV may also have psychiatric and/or drug dependence disorders. Clinicians may need to actively identify those at risk and work with policymakers to ensure the availability of appropriate care for these treatable disorders.
- Managing Shrub-Infested, Postmined Pasturelands With Goats and Cattle. Part II, Effects on Forage Biomass, Nutritive Values, and Animal PerformanceAbaye, Azenegashe Ozzie; Webb, D. Matthew; Zipper, Carl E.; Luginbuhl, Jean-Marie; Teutsch, Christopher D. (Virginia Cooperative Extension, 2001-12-09)Reclamation of mined lands in the Appalachian coal region has resulted in the successful establishment and utilization of pasture for beef cattle production. Research goals were to determine the effects of mixed grazing of goats with cattle on forage biomass, forage nutritive quality, and animal performance. The three treatments included an ungrazed control, cattle grazing alone, and mixed grazing goats with cattle.
- Why watershed-based water management makes senseFrancisco, H. (Makati City, Philippines: Philippine Institute for Development Studies, 2002)The alarming increase in the scarcity of water in various parts of the world has focused global attention on the need for a stronger and more appropriate water resource management solution. With about 166 million people in 18 countries suffering from water scarcity and about 270 million in 11 countries having "water stresses" conditions (World Bank 2002), it becomes imperative for nations to come up with more focused and direct measures that would address and stem this resource scarcity.
- Goals and Conditions for a Sustainable WorldCairns, John Jr. (Ethics in Science and Environmental Politics, 2002)This book is a collection of John Cairns, Jr.'s papers, articles, and commentaries focusing primarily on goals and conditions needed to achieve the sustainable use of the planet.
- A Survey of Usability Evaluation in Virtual Environments: Classification and Comparison of MethodsBowman, Douglas A.; Gabbard, Joseph L.; Hix, Deborah (MIT Press, 2002-08-01)Virtual environments (VEs) are a relatively new type of human-computer interface in which users perceive and act in a three-dimensional world. The designers of such systems cannot rely solely on design guidelines for traditional two-dimensional interfaces, so usability evaluation is crucial for VEs. This paper presents an overview of VE usability evaluation to organize and critically analyze diverse work from this field. First, we discuss some of the issues that differentiate VE usability evaluation from evaluation of traditional user interfaces such as GUIs. We also present a review of some VE evaluation methods currently in use, and discuss a simple classification space for VE usability evaluation methods. This classification space provides a structured means for comparing evaluation methods according to three key characteristics: involvement of representative users, context of evaluation, and types of results produced. Finally, to illustrate these concepts, we compare two existing evaluation approaches: testbed evaluation (Bowman, Johnson, & Hodges, 1999) and sequential evaluation (Gabbard, Hix, & Swan, 1999).
- Politics and water policy: A Southern Africa exampleNicol, A.; Mtisi, S. (Brighton, U.K.: Kensington Press, 2003)Drawing on fieldwork from the Sustainable Livelihoods in Southern Africa programme - largely undertaken in Zimbabwe, with some additional material from South Africa and Mozambique - this article examines the politics surrounding water resources and policy change in southern Africa. It outlines the policy contexts of water reforms in the three countries. The article then investigates: the process of institution-building accompanying water policy reform and resulting complex and politicised institutional layering; the contested meanings attached to water by different stakeholders and their implications for new institutions and decision-making processes; and the significance of the "grey area" between domestic and commercial water usage to an understanding of the role of water in household livelihoods. It draws some conclusions as to possible policy development and implementation options that could address these critical issues.
- Eco-Ethics and Sustainability Ethics (part 1)Cairns, John Jr. (Ethics in Science and Environmental Politics, 2003)This book is part one of a collection of John Cairns, Jr's papers and articles highlighting the importance of eco-ethics and sustainability ethics in protecting the biospheric life support system.