Feasibility Of Caribou Winter Habitat Analysis Using Satellite Data

Thesis (Ph.D.) University of Alaska Fairbanks, 197

Caribou Feeding Sites in Relation to Snow Characteristics in Northeastern Alaska

Caribou select areas of relatively shallow snow for winter feeding, and do so on at least two levels: broad area and microsite. They do not normally select sites with snow-packs having mean integrated Ram hardness values in excess at 85. However, in areas of relatively shallow hard-packed snow, which is easily fractured into slab-like pieces, they can obtain access to vegetation with less expenditure of energy than Ram hardness values alone would suggest. Alpine feeding areas in the Porcupine Lake basin of northeastern Alaska had this type of snow-pack in the winter of 1972-73. In typical taiga winter range, caribou use areas where the snow depth is less than 50 centimetres

Boreal forest multifunctionality is promoted by low soil organic matter content and high regional bacterial biodiversity in Northeastern Canada

Boreal forests provide important ecosystem services, most notably being the mitigation of increasing atmospheric CO2 emissions. Microbial biodiversity, particularly the local diversity of fungi, has been shown to promote multiple functions of the boreal forests of Northeastern China. However, this microbial biodiversity-multifunctionality relationship has yet to be explored in Northeastern Canada, where historical environment have shaped a different regional pool of microbial diversity. This study focuses on the relationship between the soil microbiome and ecosystem multifunctionality, as well as the influence of pH and redox potential (Eh) on the regulation of such relationship. Structural equation modelling (SEM) was used to explore the different causal relationships existing in the studied ecosystems. In a managed part of the Canadian boreal forest, 156 forest polygons were sampled to (1) estimate the α- and β-diversity of fungal and bacterial communities and (2) measure 12 ecosystem functions mainly related to soil nutrient storage and cycling. Both bacteria and fungi influenced ecosystem multifunctionality, but on their own respective functions. Bacterial β-diversity was the most important factor increasing primary productivity and soil microbial biomass, while reducing soil emitted atmospheric CO2. Environmental characteristics, particularly low levels of organic matter in soil, were shown to have the strongest positive impact on boreal ecosystem multifunctionality. Overall, our results were consistent with those obtained in Northeastern China; however, some differences need to be further explored especially considering the history of forest management in Northeastern Canada

Enhancing the health of women living with HIV: the SMART/EST Women’s Project

The principal objective of these multisite studies (Florida, New York, New Jersey: epicenters for human immunodeficiency virus [HIV] among women) was to develop and implement effective combinations of behavioral interventions to optimize the health status of the most neglected and understudied population affected by the acquired immunodeficiency syndrome (AIDS) epidemic in the United States: poor women of color living with HIV. The two studies enrolled nearly 900 women randomly assigned to “high intensity” (cognitive–behavioral stress management training combined with expressive–supportive therapy [CBSM]+ group) or “low intensity” (individual psychoeducational program) treatment conditions over a period of 9 years. The initial study of the stress management and relaxation training/expressive–supportive therapy (SMART/EST) Women’s Project (SWP I) focused on reducing depression and anxiety, as well as improving self-efficacy and overall quality of life for women with case-defined AIDS. Findings from this study demonstrated the utility of CBSM+ in reducing distress (depression, anxiety) and denial, while improving social support, self-efficacy, coping skills, and quality of life. The second study (SWP II), which included all women living with HIV, extended these findings by demonstrating that exposure to CBSM+ significantly improved the ability of the participants to take advantage of a health behavior change program encouraging the adoption and maintenance of healthier lifestyle behaviors (high levels of medication adherence, appropriate nutritional intake and physical activity, safer sexual practices, and reduced alcohol use/abuse) essential for optimal health in the context of living with HIV. SWP II also determined that the intervention program was equally beneficial to less-acculturated segments of the affected population (ie, non-English speaking HIV+ women) through the creation of culturally and linguistically sensitive Spanish and Creole versions of the program. A third study (SWP III) is currently underway to “translate” this evidence-based treatment program into Community Health Centers in Miami, New York City, and metropolitan New Jersey

Impaired immune function in Gulf War Illness

<p>Abstract</p> <p>Background</p> <p>Gulf War Illness (GWI) remains a serious health consequence for at least 11,000 veterans of the first Gulf War in the early 1990s. Our understanding of the health consequences that resulted remains inadequate, and this is of great concern with another deployment to the same theater of operations occurring now. Chronic immune cell dysfunction and activation have been demonstrated in patients with GWI, although the literature is not uniform. We exposed GWI patients and matched controls to an exercise challenge to explore differences in immune cell function measured by classic immune assays and gene expression profiling.</p> <p>Methods</p> <p>This pilot study enrolled 9 GWI cases identified from the Department of Veterans Affairs GWI registry, and 11 sedentary control veterans who had not been deployed to the Persian Gulf and were matched to cases by sex, body mass index (BMI) and age. We measured peripheral blood cell numbers, NK cytotoxicity, cytokines and expression levels of 20,000 genes immediately before, immediately after and 4 hours following a standard bicycle ergometer exercise challenge.</p> <p>Results</p> <p>A repeated-measures analysis of variance revealed statistically significant differences for three NK cell subsets and NK cytotoxicity between cases and controls (p < 0.05). Linear regression analysis correlating NK cell numbers to the gene expression profiles showed high correlation of genes associated with NK cell function, serving as a biologic validation of both the <it>in vitro </it>assays and the microarray platform. Intracellular perforin levels in NK and CD8 T-cells trended lower and showed a flatter profile in GWI cases than controls, as did the expression levels of the perforin gene PRF1. Genes distinguishing cases from controls were associated with the glucocorticoid signaling pathway.</p> <p>Conclusion</p> <p>GWI patients demonstrated impaired immune function as demonstrated by decreased NK cytotoxicity and altered gene expression associated with NK cell function. Pro-inflammatory cytokines, T-cell ratios, and dysregulated mediators of the stress response (including salivary cortisol) were also altered in GWI cases compared to control subjects. An interesting and potentially important observation was that the exercise challenge augments these differences, with the most significant effects observed immediately after the stressor, possibly implicating some block in the NK and CD8 T-cells ability to respond to "stress-mediated activation". This has positive implications for the development of laboratory diagnostic tests for this syndrome and provides a paradigm for exploration of the immuno-physiological mechanisms that are operating in GWI, and similar complex syndromes. Our results do not necessarily elucidate the cause of GWI, but they do reveal a role for immune cell dysfunction in sustaining illness.</p

Aerobic exercise training and the immune system

Healthy gay males (n = 14) at high risk for AIDS, whose human immunodeficiency virus antibody status was negative, were randomly assigned to control (n = 7) or aerobic exercise training (n = 7) groups. The exercisers received 45 min of aerobic training, at an intensity of 70-80% predicted maximum heart rate, 3 times per week. After 10 weeks, a significant 8.5% increase in fitness level was obtained for the exercisers as measured by VO2max. The control group showed no significant changes in fitness level across a similar 10 week period. Aerobic exercise training produced a significant increase in the number of T4-helper cells, 2H4+T4+ subset of T4 cells, and B1 cells. In contrast, subjects in the control group did not show significant changes in T4 cells, 2H4+T4+, or B1 cells. These data collectively provide evidence that an aerobic exercise training program may enhance both cellular and humoral immunity

Stress and immunity in individuals at risk for aids

We have examined psychosocial and immune system stress responses in gay men before and after their notification of human immunodeficiency virus (HIV‐1) status and as a consequence of stress management intervention procedures. Prior to notification, early stage, asymptomatic, seropositive men displayed compromised immunity as evidenced by significant decreases in CD4+ cell number, the helper subset (CD29 + CD4 +), CD4 +/CD8 + ratio, and lymphocyte responses to mitogens. Prior to diagnosis, both seronegative and seropositive men revealed suppression of NK cell cytotoxicity and mitogen responsivity relative to matched laboratory control subjects not awaiting diagnosis. Immune suppression in these seronegative men disappeared after diagnosis, indicating its relationship to anticipation of serostatus notification. We also found that a 10‐week program of aerobic exercise or psychosocial stress management buffered the psychological impact of notification of seropositivity. The aerobic exercise program produced a significant increase in CD4+ cells for seronegatives and a smaller increase approaching significance for seropositives. The psychosocial intervention, which included relaxation training and cognitive stress management, produced significant increases in CD4+ and NKH.1 + for seronegatives and CD45R + CD4 + cell number and mitogen responsivity for seropositives. We are assessing our interventions as tools for retarding immune deterioration and disease progression in HIV‐1 seropositive individuals

Disparities in psychological, neuroendocrine, and immunologic patterns in asymptomatic HIV-1 seropositive and seronegative gay men

The present study concurrently measured psychological distress (state anxiety, depression, confusion, and intrusive thoughts), neuroendocrine (plasma cortisol concentrations), and immunologic [lymphocyte proliferative responses to phytohemagglutinin (PHA) and pokeweed mitogen (PWM)] changes in the 5-week periods preceding and following serostatus notification among asymptomatic Human Immunodeficiency Virus-type 1 (HIV-1) seropositive and seronegative gay men. Seropositives, as opposed to seronegatives, showed a disparity in predicted relationships among distress, cortisol, and immunologic measures across the prenotification to postnotification period. Individual difference analyses suggested that among seropositives, in contrast to seronegatives, plasma cortisol concentrations were negatively correlated with psychological distress and positively correlated with responses to PHA (assessed at study entry and after serostatus notification). This pattern in seropositives could not be explained by differences in prenotification perceived risk of infectivity, extraneous environmental stressors, or CD4 cell counts within the seropositive group

Aerobic circuit exercise training: Effect on adolescents with well-controlled insulin-dependent diabetes mellitus

Objectives: To test the safety and effects of exercise conditioning on cardiorespiratory fitness, body composition, muscle strength, glucose regulation, and lipid/cholesterol levels. Subjects: Ten male adolescents with insulin-dependent diabetes mellitus (IDDM) and 10 adolescent nondiabetic (ND) subjects. Design: Pretest, posttest intervention trial with control group. Setting: University-based human performance laboratory. Intervention: Mixed endurance and calisthenic/strength activities performed at a rapid pace three times weekly for 12 weeks. Results: Only one subject with IDDM experienced hypoglycemia after a single exercise session. Both subject groups improved their cardiorespiratory endurance ( p < .05). Lean body mass of IDDM subjects increased by 3.5% ( p < .05). Subjects with and without IDDM lowered their percent body fat ( p < .05 and .001, respectively). Strength improvement of IDDM subjects ranged from 13.7% ( p < .001) to 44.4% ( p < .01), depending upon the maneuver. Fasting blood plasma glucose for all subjects was unchanged by training, but glycosylated hemoglobin A 1c of IDDM subjects was reduced by .96 percentage point ( p < .05). Reductions of HbA 1c benefitted subjects exhibiting poor preconditioning glycemic control. Low-density lipoprotein cholesterol was decreased in subjects with IDDM ( p < .05), but not total cholesterol or triglycerides. Conclusion: Adolescents with IDDM undergoing aerobic circuit training improve their cardiorespiratory endurance, muscle strength, lipid profile, and glucose regulation. Aerobic circuit training is safe for properly trained and monitored adolescent diabetics