956 research outputs found
Fellow travelers: Indians and Europeans together on the early American trail
The European exploration of America has traditionally conjured up images of Europeans intrepidly scanning horizons, meticulously detailing maps, and graciously offering curious natives access to God and goods. More than two decades of anthropological, historical, and ethnohistorical scholarship have tempered this heroic image and shown in great detail the complex and often contradictory role Indians played in this grand drama. Consequently, one can no longer picture colonial-era European explorers or travelers without also envisioning their Indian companions, both men and women, guiding the way, carrying the baggage, gathering the food, and providing needed information. This dissertation examines the character of the personal relationships that Indians and Europeans formed together while on North American expeditions of conquest, trade, and Christianizing between 1520 and 1800.;Travel entailed confrontations with the elements that could literally wipe out a party that made a wrong turn, ignored or misread the weather, or misjudged the current of a given rapid. Furthermore, poor provision planning or diplomatic bungling could also bring the grandest plans to grand disaster. But while battling the elements, Indian and European travel partners often battled each other. They played a subtle game of tug-of-war for control over the course, pace, and timing of travel. They fumed and connived over whose leadership, strategies, and values should hold sway. They wrestled over whose deities should be honored, and they derided each other\u27s individual and collective abilities when one failed to live up to the other\u27s visions of the ideal traveler. Tensions ranged from the subtlest forms of petty one-upmanship to physical coercion, and even occasional fisticuffs. It was the trail\u27s defining conditions, its dangers, unfamiliarity, and isolation from comfortable and reassuring trappings of social prestige that exacerbated these tensions. The resulting contests reveal how different cultural meanings could swirl around trips and travel events often seen by historians as relatively straightforward moments in Europe\u27s colonial expansion. They also demonstrate how individuals of different backgrounds constructed themselves and their fellow travelers while on the trail
Markers of Maternal and Infant Metabolism are Associated with Ventricular Dysfunction in Infants of Obese Women with Type 2 Diabetes
BACKGROUND
To test the hypothesis that infants born to obese women with pregestational type 2 diabetes mellitus (IBDM) have ventricular dysfunction at one month that is associated with markers of maternal lipid and glucose metabolism.
METHODS
In a prospective observational study of IBDM (OB+DM, n=25), echocardiography measures of septal, left (LV) and right ventricular (RV) function and structure were compared at one month of age to infants born to OB mothers without DM (OB, n=24), and non-OB without DM (Lean, n=23). Basal maternal lipid and glucose kinetics and maternal plasma and infant (cord) plasma were collected for hormone and cytokine analyses.
RESULTS
RV, LV, and septal strain measures were lower in the OB+DM infants vs. other groups, without evidence of septal hypertrophy. Maternal hepatic insulin sensitivity, maternal plasma free fatty acid concentration, and cord plasma insulin and leptin most strongly predicted decreased septal strain in the OB+DM infants.
CONCLUSION
IBDM’s have reduced septal function at one month in the absence of septal hypertrophy, which is associated with altered maternal and infant lipid and glucose metabolism. These findings suggest that maternal obesity and DM may have a prolonged impact on the cardiovascular health of their offspring, despite resolution of cardiac hypertrophy
Impact of Cannabis Use on Treatment Outcomes among Adults Receiving Cognitive-Behavioral Treatment for PTSD and Substance Use Disorders
Background: Research has demonstrated a strong link between trauma, posttraumatic stress disorder (PTSD) and substance use disorders (SUDs) in general and cannabis use disorders in particular. Yet, few studies have examined the impact of cannabis use on treatment outcomes for individuals with co-occurring PTSD and SUDs. Methods: Participants were 136 individuals who received cognitive-behavioral therapies for co-occurring PTSD and SUD. Multivariate regressions were utilized to examine the associations between baseline cannabis use and end-of-treatment outcomes. Multilevel linear growth models were fit to the data to examine the cross-lagged associations between weekly cannabis use and weekly PTSD symptom severity and primary substance use during treatment. Results: There were no significant positive nor negative associations between baseline cannabis use and end-of-treatment PTSD symptom severity and days of primary substance use. Cross-lagged models revealed that as cannabis use increased, subsequent primary substance use decreased and vice versa. Moreover, results revealed a crossover lagged effect, whereby higher cannabis use was associated with greater PTSD symptom severity early in treatment, but lower weekly PTSD symptom severity later in treatment. Conclusion: Cannabis use was not associated with adverse outcomes in end-of-treatment PTSD and primary substance use, suggesting independent pathways of change. The theoretical and clinical implications of the reciprocal associations between weekly cannabis use and subsequent PTSD and primary substance use symptoms during treatment are discussed
Effects of Cocaine and/or Heroin Use on Resting Cardiovascular Function
Background: Regular cocaine and/or heroin use is associated with major health risks, especially cardiovascular disease (CVD), but confounded by other factors.
Objectives: We examined effects of chronic (years of regular use) and recent (past-month) use of cocaine and heroin, controlling for other factors, on resting cardiovascular function.
Methods: In a sample of cocaine and/or heroin users (N=292), we obtained data on demographics, body mass index (BMI), history of substance use, and electrocardiogram, heart rate (HR) and blood pressure (BP). Following bivariate correlations, three-block (1: demographics, BMI; 2: tobacco, alcohol, marijuana; 3: cocaine, heroin) regression analyses were conducted to predict cardiovascular measures.
Results: Higher BMI predicted increased systolic and diastolic BP (as did older age), increased supine HR, and longer QRS duration, QTc interval, PR interval, and P-wave duration. Recent substance use had more reliable effects than chronic use on cardiovascular measures. Past-month marijuana-use days predicted higher systolic BP, lower supine HR, and greater likelihood of early repolarization and ST elevation, whereas average daily marijuana use predicted shorter QTc interval. Average daily alcohol use predicted higher diastolic BP, higher supine HR and lower likelihood of sinus bradycardia (HRbpm). Past-month tobacco-use days predicted shorter QTc interval and increased likelihood of profound bradycardia (HRbpm). Past-month heroin-use days predicted lower seated HR, greater likelihood of sinus bradycardia and lower likelihood of left ventricular hypertrophy. More years of regular cocaine use and past-month cocaine-use days predicted longer QTc interval.
Conclusions: Cocaine and heroin incrementally predicted modest variance in resting bradycardia and QTc interval. Clinicians should first consider demographics and recent use of tobacco, alcohol and marijuana before assuming cocaine and heroin affect these measures
Impacts of Climate Change on indirect human exposure to pathogens and chemicals from agriculture
Objective: Climate change is likely to affect the nature of pathogens and chemicals in the environment and their fate and transport. Future risks of pathogens and chemicals could therefore be very different from those of today. In this review, we assess the implications of climate change for changes in human exposures to pathogens and chemicals in agricultural systems in the United Kingdom and discuss the subsequent effects on health impacts.
Data sources: In this review, we used expert input and considered literature on climate change ; health effects resulting from exposure to pathogens and chemicals arising from agriculture ; inputs of chemicals and pathogens to agricultural systems ; and human exposure pathways for pathogens and chemicals in agricultural systems.
Data synthesis: We established the current evidence base for health effects of chemicals and pathogens in the agricultural environment ; determined the potential implications of climate change on chemical and pathogen inputs in agricultural systems ; and explored the effects of climate change on environmental transport and fate of different contaminant types. We combined these data to assess the implications of climate change in terms of indirect human exposure to pathogens and chemicals in agricultural systems. We then developed recommendations on future research and policy changes to manage any adverse increases in risks.
Conclusions: Overall, climate change is likely to increase human exposures to agricultural contaminants. The magnitude of the increases will be highly dependent on the contaminant type. Risks from many pathogens and particulate and particle-associated contaminants could increase significantly. These increases in exposure can, however, be managed for the most part through targeted research and policy changes
Reference Ranges of Left Ventricular Strain Measures by Two-Dimensional Speckle-Tracking Echocardiography in Children: A Systematic Review and Meta-Analysis
BACKGROUND:
Establishment of the range of reference values and associated variations of two-dimensional speckle-tracking echocardiography (2DSTE)-derived left ventricular (LV) strain is a prerequisite for its routine clinical adoption in pediatrics. The aims of this study were to perform a meta-analysis of normal ranges of LV global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) measurements derived by 2DSTE in children and to identify confounding factors that may contribute to variance in reported measures.
METHODS:
A systematic review was launched in MEDLINE, Embase, Scopus, the Cumulative Index to Nursing and Allied Health Literature, and the Cochrane Library. Search hedges were created to cover the concepts of pediatrics, STE, and left-heart ventricle. Two investigators independently identified and included studies if they reported 2DSTE-derived LV GLS, GCS, or GRS. The weighted mean was estimated by using random effects models with 95% CIs, heterogeneity was assessed using the Cochran Q statistic and the inconsistency index (I(2)), and publication bias was evaluated using the Egger test. Effects of demographic (age), clinical, and vendor variables were assessed in a metaregression.
RESULTS:
The search identified 2,325 children from 43 data sets. The reported normal mean values of GLS among the studies varied from -16.7% to -23.6% (mean, -20.2%; 95% CI, -19.5% to -20.8%), GCS varied from -12.9% to -31.4% (mean, -22.3%; 95% CI, -19.9% to -24.6%), and GRS varied from 33.9% to 54.5% (mean, 45.2%; 95% CI, 38.3% to 51.7%). Twenty-six studies reported longitudinal strain only from the apical four-chamber view, with a mean of -20.4% (95% CI, -19.8% to -21.7%). Twenty-three studies reported circumferential strain (mean, -20.3%; 95% CI, -19.4% to -21.2%) and radial strain (mean, 46.7%; 95% CI, 42.3% to 51.1%) from the short-axis view at the midventricular level. A significant apex-to-base segmental longitudinal strain gradient (P 94% and P < .001 for each strain measure), which was not explained by age, gender, body surface area, blood pressure, heart rate, frame rate, frame rate/heart rate ratio, tissue-tracking methodology, location of reported strain value along the strain curve, ultrasound equipment, or software. The metaregression showed that these effects were not significant determinants of variations among normal ranges of strain values. There was no evidence of publication bias (P = .40).
CONCLUSIONS:
This study defines reference values of 2DSTE-derived LV strain in children on the basis of a meta-analysis. In healthy children, mean LV GLS was -20.2% (95% CI, -19.5% to -20.8%), mean GCS was -22.3% (95% CI, -19.9% to -24.6%), and mean GRS was 45.2% (95% CI, 38.3% to 51.7%). LV segmental longitudinal strain has a stable apex-to-base gradient that is preserved throughout maturation. Although variations among different reference ranges in this meta-analysis were not dependent on differences in demographic, clinical, or vendor parameters, age- and vendor-specific referenced ranges were established as well
Haptoglobin Genotype and the Rate of Renal Function Decline in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications Study
Many patients with type 1 diabetes develop renal disease despite moderately good metabolic control, suggesting other risk factors may play a role. Recent evidence suggests that the haptoglobin (HP) 2-2 genotype, which codes for a protein with reduced antioxidant activity, may predict renal function decline in type 1 diabetes. We examined this hypothesis in 1,303 Caucasian participants in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study. HP genotype was determined by polyacrylamide gel electrophoresis. Glomerular filtration rate was estimated by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and albumin excretion based on timed urine samples. Participants were followed up for a mean of 22 years. HP genotype was significantly associated with the development of sustained estimated glomerular filtration rate (GFR) \u3c60 mL/min/1.73 m2and with end-stage renal disease (ESRD), with HP 2-2 having greater risk than HP 2-1 and 1-1. No association was seen with albuminuria. Although there was no treatment group interaction, the associations were only significant in the conventional treatment group, where events rates were much higher. We conclude that the HP genotype is significantly associated with the development of reduced GFR and ESRD in the DCCT/EDIC study
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