85 research outputs found
Seasonal Temperature Changes with Elevation on Mount Washington
The summit of Mount Washington is warming more slowly than surrounding lower elevations of the Northeast, which is opposite to climate model projections and observations in other mountain ranges. A looming scientific question is: why? A hypothesis is that the exposure of the summit to the âfree troposphereâ, an air mass that sits above the ground-based boundary layerâ, for approximately half the year is imparting a slower warming at the summit. This research project takes a preliminary first step toward answering this question by finding methods to determine when Mount Washington is in the boundary layer. Temperature readings from the summit, and the bases of the Cog Railway (west side) and Auto Road (east side) from 2015-2016 were used to calculate lapse rates. Lapse rates were plotted for their monthly and seasonal variability. For daily variability, the lapse rates were low at night and increased during the day. Spring and summer were found to have to greatest lapse rates compared to fall and winter months. During the spring and summer the sun is higher in the sky, which leads to more warming of the ground and greater vertical motions that grow the boundary layer to the summit altitude frequently
The Fugitive for Mississippi
This poem pictures an orphan who imitates the desperate recklessness of Huckleberry Finn as he flees his broken past and present life
IL-10-conditioned dendritic cells, decommissioned for recruitment of adaptive immunity, elicit innate inflammatory gene products in response to danger signals
Dendritic cells (DCs) are the professional APCs of the immune system, enabling T cells to perceive and respond appropriately to potentially dangerous microbes, while also being able to maintain T cell tolerance toward self. In part, such tolerance can be determined by IL-10 released from certain types of regulatory T cells. IL-10 has previously been shown to render DCs unable to activate T cells and it has been assumed that this process represents a general block in maturation. Using serial analysis of gene expression, we show that IL-10 pretreatment of murine bone marrow-derived DCs alone causes significant changes in gene expression. Furthermore, these cells retain the ability to respond to Toll-like receptor agonists, but in a manner skewed toward the selective induction of mediators known to enhance local inflammation and innate immunity, among which we highlight a novel CXCR2 ligand, DC inflammatory protein-1. These data suggest that, while the presence of a protolerogenic and purportedly anti-inflammatory agent such as IL-10 precludes DCs from acquiring their potential as initiators of adaptive immunity, their ability to act as initiators of innate immunity in response to Toll-like receptor signaling is enhanced
Implications of leg length for metabolic health and fitness
BACKGROUND AND OBJECTIVES: Several studies have linked longer legs with favorable adult metabolic health outcomes and greater offspring birth weight. A recent Mendelian randomization study suggested a causal link between height and cardiometabolic risk; however, the underlying reasons remain poorly understood. METHODOLOGY: Using a cross-sectional design, we tested in a convenience sample of 70 healthy young women whether birth weight and tibia length as markers of early-life conditions associated more strongly with metabolically beneficial traits like organ size and skeletal muscle mass (SMM) than a statistically derived height-residual variable indexing later, more canalized growth. RESULTS: Consistent with the âdevelopmental origins of health and diseaseâ hypothesis, we found relatively strong associations of tibia lengthâbut not birth weightâwith adult organ size, brain size, SMM and resting energy expenditure measured by magnetic resonance imaging (MRI), dual-energy X-ray absorptiometry and indirect calorimetry, respectively. CONCLUSIONS AND IMPLICATIONS: Building on prior work, these results suggest that leg length is a sensitive marker of traits directly impacting metabolic and reproductive health. Alongside findings in the same sample relating tibia length and height-residual to MRI-measured pelvic dimensions, we suggest there may exist a degree of coordination in the development of long bone, lean mass and pelvic traits, possibly centered on early, pre-pubertal growth periods. Such phenotypic coordination has important implications for fitness, serving to benefit both adult health and the health of offspring in subsequent generations
Growth, body composition, and cardiovascular and nutritional risk of 5- to 10-y-old children consuming vegetarian, vegan, or omnivore diets.
BACKGROUND: Plant-based diets (PBDs) are increasingly recommended for human and planetary health. However, comprehensive evidence on the health effects of PBDs in children remains incomplete, particularly in vegans. OBJECTIVES: To quantify differences in body composition, cardiovascular risk, and micronutrient status of vegetarian and vegan children relative to omnivores and to estimate prevalence of abnormal micronutrient and cholesterol status in each group. METHODS: In a cross-sectional study, Polish children aged 5-10 y (63 vegetarian, 52 vegan, 72 matched omnivores) were assessed using anthropometry, deuterium dilution, DXA, and carotid ultrasound. Fasting blood samples, dietary intake, and accelerometry data were collected. RESULTS: All results are reported relative to omnivores. Vegetarians had lower gluteofemoral adiposity but similar total fat and lean mass. Vegans had lower fat indices in all regions but similar lean mass. Both groups had lower bone mineral content (BMC). The difference for vegetarians attenuated after accounting for body size but remained in vegans (total body minus the head: -3.7%; 95% CI: -7.0, -0.4; lumbar spine: -5.6%; 95% CI: -10.6, -0.5). Vegetarians had lower total cholesterol, HDL, and serum B-12 and 25-hydroxyvitamin D [25(OH)D] without supplementation but higher glucose, VLDL, and triglycerides. Vegans were shorter and had lower total LDL (-24 mg/dL; 95% CI: -35.2, -12.9) and HDL (-12.2 mg/dL; 95% CI: -17.3, -7.1), high-sensitivity C-reactive protein, iron status, and serum B-12 (-217.6 pmol/L; 95% CI: -305.7, -129.5) and 25(OH)D without supplementation but higher homocysteine and mean corpuscular volume. Vitamin B-12 deficiency, iron-deficiency anemia, low ferritin, and low HDL were more prevalent in vegans, who also had the lowest prevalence of high LDL. Supplementation resolved low B-12 and 25(OH)D concentrations. CONCLUSIONS: Vegan diets were associated with a healthier cardiovascular risk profile but also with increased risk of nutritional deficiencies and lower BMC and height. Vegetarians showed less pronounced nutritional deficiencies but, unexpectedly, a less favorable cardiometabolic risk profile. Further research may help maximize the benefits of PBDs in children
Estimating body mass and composition from proximal femur dimensions using dual energy x-ray absorptiometry.
Body mass prediction from the skeleton most commonly employs femoral head diameter (FHD). However, theoretical predictions and empirical data suggest the relationship between mass and FHD is strongest in young adults, that bone dimensions reflect lean mass better than body or fat mass and that other femoral measurements may be superior. Here, we generate prediction equations for body mass and its components using femoral head, neck and proximal shaft diameters and body composition data derived from dual-energy x-ray absorptiometry (DXA) scans of young adults (nâ=â155, 77 females and 78 males, mean age 22.7â±â1.3 years) from the Andhra Pradesh Children and Parents Study, Hyderabad, India. Sex-specific regression of log-transformed data on femoral measurements predicted lean mass with smaller standard errors of estimate (SEEs) than body mass (12-14% and 16-17% respectively), while none of the femoral measurements were significant predictors of fat mass. Subtrochanteric mediolateral shaft diameter gave lower SEEs for lean mass in both sexes and for body mass in males than FHD, while FHD was a better predictor of body mass in women. Our results provide further evidence that lean mass is more closely related to proximal femur dimensions than body or fat mass and that proximal shaft diameter is a better predictor than FHD of lean but not always body mass. The mechanisms underlying these relationships have implications for selecting the most appropriate measurement and reference sample for estimating body or lean mass, which also depend on the question under investigation.This work was funded by a British Academy International Partnership and Mobility Scheme Grant to EP and VM, and a Leverhulme Trust/Isaac Newton Trust Early Career Fellowship to EP. The third survey wave of APCAPS data collection was supported by a Wellcome Trust Strategic Award (grant no. 084774) and subsidised access to DXA scan facilities given by the National Institute of Nutrition (Directors), Indian Council for Medical Research. TJC was funded by MRC grant MR/M012069/1
GPS-determination of along-strike variation in Cascadia margin kinematics: Implications for relative plate motion, Subduction zone coupling, and permanent deformation
Highâprecision GPS geodesy in the Pacific Northwest provides the first synoptic view of the alongâstrike variation in Cascadia margin kinematics. These results constrain interfering deformation fields in a region where typical earthquake recurrence intervals are one or more orders of magnitude longer than the decadesâlong history of seismic monitoring and where geologic studies are sparse. Interseismic strain accumulation contributes greatly to GPS station velocities along the coast. After correction for a simple elastic dislocation model, important residual motions remain, especially south of the international border. The magnitude of northward forearc motion increases southward from western Washington (3â7 mm/yr) to northern and central Oregon (âŒ9 mm/yr), consistent with oblique convergence and geologic constraints on permanent deformation. The marginâparallel strain gradient, concentrated in western Washington across the populated Puget Lowlands, compares in magnitude to shortening across the Los Angeles Basin. Thus crustal faulting also contributes to seismic hazard. Farther south in southern Oregon, northâwestward velocities reflect the influence of PacificâNorth America motion and impingement of the Sierra Nevada block on the Pacific Northwest. In contrast to previous notions, some deformation related to the Eastern California shear zone crosses northernmost California in the vicinity of the Klamath Mountains and feeds out to the Gorda plate margin
Presentâday motion of the Sierra Nevada block and some tectonic implications for the Basin and Range province, North American Cordillera
Global Positioning System (GPS) data from five sites on the stable interior of the Sierra Nevada block are inverted to describe its angular velocity relative to stable North America. The velocity data for the five sites fit the rigid block model with rms misfits of 0.3 mm/yr (north) and 0.8 mm/yr (east), smaller than independently estimated data uncertainty, indicating that the rigid block model is appropriate. The new Euler vector, 17.0°N, 137.3°W, rotation rate 0.28 degrees per million years, predicts that the block is translating to the northwest, nearly parallel to the plate motion direction, at 13â14 mm/yr, faster than previous estimates. Using the predicted Sierra Nevada block velocity as a kinematic boundary condition and GPS, VLBI and other data from the interior and margins of the Basin and Range, we estimate the velocities of some major boundary zone faults. For a transect approximately perpendicular to plate motion through northern Owens Valley, the eastern California shear zone (western boundary of the Basin and Range province) accommodates 11±1 mm/yr of rightâlateral shear primarily on two faults, the Owens ValleyâWhite Mountain (3±2 mm/yr) and Fish Lake Valley (8±2 mm/yr) fault zones, based on a viscoelastic coupling model that accounts for the effects of the 1872 Owens Valley earthquake and the rheology of the lower crust. Together these two faults, separated by less than 50 km on this transect, define a region of high surface velocity gradient on the eastern boundary of the Sierra Nevada block. The Wasatch Fault zone accommodates less than 3±1 mm/yr of eastâwest extension on the eastern boundary of the Basin and Range province. Remaining deformation within the Basin and Range interior is also probably less than 3 mm/yr
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