Factors affecting the political stability of certain Latin American countries

The purpose of this paper is to test the hypothesis that the factors that have produced political stability in Mexico have been largely absent from the political development experience of other Latin American countries that have experi~nced instability. Based on the literature on political development theory and on an historical survey of political development in Mexico, the factors of consensus, legitimacy and institutionalization are identified as having been primarily responsible for political stability. These factors have allowed the Mexican political system to respond successfully to the destabilizing pressures of modernization, economic development, social mobilization and urbanization, as well as the external pressures of economic dependence. From an analysis of political development in Argentina, Chile and Brazil, it is my conclusion that these countries have failed to develop a consensus, suffered repeated crises of legitimacy, and failed to develop political institutions to check the destabilizing forces of modernization, the military and external influences

Systemic Insulin Sensitivity and Skeletal Muscle Akt Signaling in Rats Artificially Selected for Low and High Aerobic Capacity

The mechanism(s) linking physical inactivity, obesity, and type-II diabetes are unclear. I hypothesized low intrinsic aerobic capacity is associated with reduced systemic insulin sensitivity via skeletal muscle insulin signaling. After 34 generations of selective breeding, high aerobic capacity (HCR) rats exhibited an 8-fold increase in running distance vs low aerobic capacity (LCR) rats (n=14 per group). LCR rats had higher rates of weight gain vs HCR (p\u3c0.05) though food consumption was constant (p=0.86) over a 12-week study. Rats were divided into 4 groups: 1) LCR-Sham Surgery, 2) LCR-Catheterization, 3) HCR-Sham Surgery or 4) HCR-Catheterization (n=7 per group). Euglycemic-hyperinsulinemic clamps on catheterized rats tested insulin sensitivity while sham LCR and HCR were used for basal tissue analysis. Plasma insulin levels did not differ during the clamps, but LCR required lower glucose infusion rates than HCR (p\u3c0.05). Upon insulin stimulation, both absolute and normalized phospho-Akt(Ser473) of soleus muscle were significantly increased in HCR above basal group (p\u3c0.05), but not in LCR. No difference was observed between insulin-stimulated phospho-Akt(Ser473) of HCR and LCR groups . These data support that LCR is linked to a reduction in insulin sensitivity in vivo without impairments of insulin-stimulated skeletal muscle phospho-Akt(Ser473) vs HCR rats

Metabolic foundations of exercise-induced cardiac growth.

Regular aerobic exercise promotes physiological cardiac growth, which is an adaptive response thought to enable the heart to meet higher physical demands. Cardiac growth involves coordination of catabolic and anabolic activities to support ATP generation, macromolecule biosynthesis, and myocyte hypertrophy. Although previous studies suggest that exercise-induced reductions in cardiac glycolysis are critical for physiological myocyte hypertrophy, it remains unclear how exercise influences the many interlinked pathways of metabolism that support adaptive remodeling of the heart. In this thesis project, we tested the general hypothesis that aerobic exercise promotes physiological cardiac growth by coordinating myocardial metabolism to promote glucose-supported anabolic pathway activity. Because little is known about how cardiac mitochondria adapt to exercise, we first characterized exercise-induced changes in murine cardiac mitochondrial metabolism and found that treadmill exercise has minimal effects on respiration and does not influence ADP sensitivity in the isolated organelle (Chapter II). These findings indicate that increases in cardiac mitochondrial respiration during exercise likely occur via changes in mitochondrial substrate abundance or via allosteric regulation of metabolic enzymes. To better describe how exercise influences cardiac metabolism in vivo, we examined changes in cardiac metabolite abundance via untargeted metabolomics. Although exercise altered metabolite abundances in female hearts more than male hearts, physiological cardiac growth was evident only in male hearts. Nevertheless, in both male and female hearts, exercise increased circulating and intracardiac ketone bodies and branched-chain amino acids (BCAAs). The idea that exercise-induced elevations in BCAAs are critical for exercise-induced cardiac growth is suggested by data showing that a diet deficient in BCAAs prevents cardiac growth following a treadmill exercise training program (Chapter III). We next standardized a noninvasive method for delivering 13C6-labeled glucose to mice via liquid diet. Paired with resolution mass spectrometry, this method enables insight into relationships between anabolic and catabolic pathways in the heart. We found that low cardiac phosphofructokinase (PFK) activity, which occurs transiently during a bout of intense treadmill exercise, increases glycogen storage and promotes biosynthesis of 5-aminoimidazole-4-carboxyamide ribonucleotide (AICAR). In vivo stable isotope tracing paired with native protein complex separation suggest that elevated levels of AICAR that occur with low PFK activity occur via formation of a multimeric complex containing several metabolic enzymes that appear to promote metabolic channeling (Chapter IV). We then performed deep network tracing following various durations of exercise training and found that cardiac glucose oxidation, amino acid synthesis, Krebs cycle activity, and glycogen synthesis increase in the early phases of an exercise training program, but progressively return to levels observed in non-exercised hearts following 4 weeks of training (Chapter V). Collectively, the findings of this thesis project provide a new working model of exercise-induced cardiac growth. Our data suggest that glucose-derived carbon is a major source of both energy and building material for the remodeling heart that integrates with BCAA metabolism to promote physiological cardiac growth

RI Veterans for Justice Grievance over ROTC Discrimination

A letter from the RI Veterans for Justice speaking out against the ROT

Metabolic Mechanisms of Exercise-Induced Cardiac Remodeling

Exercise has a myriad of physiological benefits that derive in part from its ability to improve cardiometabolic health. The periodic metabolic stress imposed by regular exercise appears fundamental in driving cardiovascular tissue adaptation. However, different types, intensities, or durations of exercise elicit different levels of metabolic stress and may promote distinct types of tissue remodeling. In this review, we discuss how exercise affects cardiac structure and function and how exercise-induced changes in metabolism regulate cardiac adaptation. Current evidence suggests that exercise typically elicits an adaptive, beneficial form of cardiac remodeling that involves cardiomyocyte growth and proliferation; however, chronic levels of extreme exercise may increase the risk for pathological cardiac remodeling or sudden cardiac death. An emerging theme underpinning acute as well as chronic cardiac adaptations to exercise is metabolic periodicity, which appears important for regulating mitochondrial quality and function, for stimulating metabolism-mediated exercise gene programs and hypertrophic kinase activity, and for coordinating biosynthetic pathway activity. In addition, circulating metabolites liberated during exercise trigger physiological cardiac growth. Further understanding of how exercise-mediated changes in metabolism orchestrate cell signaling and gene expression could facilitate therapeutic strategies to maximize the benefits of exercise and improve cardiac health

Emergency Room Use by Undocumented Mexican Immigrants

This study examined emergency room use by undocumented Mexican immigrants and their sources of health care information. Thirty-eight percent of the respondents reported that they would use a hospital emergency room (ER) for primary medical care. ER use rates declined with time spent in the United States. Emergency room use rates varied significantly by region. Respondents receiving information from a church reported less ER use, compared to all others; respondents receiving information from U.S. newspapers reported higher ER use rates. Lack of health care access for undocumented immigrants remains a public health issue as well as a social justice concern

Gaseous Electronics

Contains research objectives and reports on one research project.Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DA 28-043-AMC-02536(E