5,738 research outputs found
Endothelium-Dependent Delivery of Insulin to Muscle Interstitium
Insulin contributes to skeletal muscle glucose uptake by increasing blood flow and recruiting perfused capillaries. In this issue of Cell Metabolism, Kubota et al. (2011) show that deletion of IRS-2 in endothelial cells in mice causes impaired transcapillary insulin transport, decreased insulin-stimulated glucose uptake in muscle, and mild glucose intolerance
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Response to Comment on: Keenan et al. (2010) Residual Insulin Production and Pancreatic ÎČ-Cell Turnover After 50 Years of Diabetes: Joslin Medalist Study. Diabetes 2010;59:2846â2853
The annual course of precipitation over much of the United States: observed versus GCM simulation
General Circulation Models (GCMs) may be useful in estimating the ecological impacts of global climatic change. We analyzed seasonal weather patterns over the conterminous United States and determined that regional patterns of rainfall seasonality appear to control the distributions of the Nation's major biomes. These regional patterns were compared to the output from three GCMs for validation. The models appear to simulate the appropriate seasonal climates in the northern tier of states. However, the spatial extent of these regions is distorted. None of the models accurately portrayed rainfall seasonalities in the southern tier of states, where biomes are primarily influenced by the Bermuda High
Testing metallicity indicators at z~1.4 with the gravitationally lensed galaxy CASSOWARY 20
We present X-shooter observations of CASSOWARY 20 (CSWA 20), a star-forming
(SFR ~6 Msol/yr) galaxy at z=1.433, magnified by a factor of 11.5 by the
gravitational lensing produced by a massive foreground galaxy at z=0.741. We
analysed the integrated physical properties of the HII regions of CSWA 20 using
temperature- and density-sensitive emission lines. We find the abundance of
oxygen to be ~1/7 of solar, while carbon is ~50 times less abundant than in the
Sun. The unusually low C/O ratio may be an indication of a particularly rapid
timescale of chemical enrichment. The wide wavelength coverage of X-shooter
gives us access to five different methods for determining the metallicity of
CSWA 20, three based on emission lines from HII regions and two on absorption
features formed in the atmospheres of massive stars. All five estimates are in
agreement, within the factor of ~2 uncertainty of each method. The interstellar
medium of CSWA 20 only partially covers the star-forming region as viewed from
our direction; in particular, absorption lines from neutrals and first ions are
exceptionally weak. We find evidence for large-scale outflows of the
interstellar medium (ISM) with speeds of up 750 km/s, similar to the values
measured in other high-z galaxies sustaining much higher rates of star
formation.Comment: 18 pages, 11 figures, accepted for publication in MNRA
First-principles study of (BiScO3){1-x}-(PbTiO3){x} piezoelectric alloys
We report a first-principles study of a class of (BiScO3)_{1-x}-(PbTiO3)_x
(BS-PT) alloys recently proposed by Eitel et al. as promising materials for
piezoelectric actuator applications. We show that (i) BS-PT displays very large
structural distortions and polarizations at the morphotropic phase boundary
(MPB) (we obtain a c/a of ~1.05-1.08 and P_tet of ~1.1 C/m^2); (ii) the
ferroelectric and piezoelectric properties of BS-PT are dominated by the onset
of hybridization between Bi/Pb-6p and O-2p orbitals, a mechanism that is
enhanced upon substitution of Pb by Bi; and (iii) the piezoelectric responses
of BS-PT and Pb(Zr_{1-x}Ti_x)O3 (PZT) at the MPB are comparable, at least as
far as the computed values of the piezoelectric coefficient d_15 are concerned.
While our results are generally consistent with experiment, they also suggest
that certain intrinsic properties of BS-PT may be even better than has been
indicated by experiments to date. We also discuss results for PZT that
demonstrate the prominent role played by Pb displacements in its piezoelectric
properties.Comment: 6 pages, with 3 postscript figures embedded. Uses REVTEX and epsf
macros. Also available at
http://www.physics.rutgers.edu/~dhv/preprints/ji_bi/index.htm
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Sexual Dysfunction as a Marker of Cardiovascular Disease in Males With 50 or More Years of Type 1 Diabetes
OBJECTIVE Vascular dysfunction is a major contributor to diabetes complications. It is also the primary physiologic cause of erectile dysfunction and considered an independent predictor of cardiovascular disease (CVD) in males over age 40 years. A cohort of individuals with 50 or more years of type 1 diabetes, Joslin Medalists, have low rates of small but not large vessel complications. This study aims to identify the prevalence and longitudinal association of sexual dysfunction (SD) with CVD in Joslin Medalists. RESEARCH DESIGN AND METHODS Description and association of self-assessment of SD in males of the Medalist cohort by self-reported sexual problems with CVD. SD is validated through the use of the abbreviated International Index of Erectile Dysfunction (IIEF). RESULTS Of 301 males in the Medalist Study, 69.8% reported a history of SD. Unadjusted risk factors included elevated glycated hemoglobin (HbA1c) (P = 0.02), elevated BMI (P = 0.03), higher total cholesterol (P = 0.02), lower HDL (P 0.05) with SD. Current report of SD (IIEF score â€17) in a subset of Medalists was significantly correlated with self-reported longitudinal SD. CONCLUSIONS SD in those with extreme-duration type 1 diabetes is independently associated with CVD, representing a large-vessel pattern. The findings suggest that SD may predict CVD in those with type 1 diabetes of long duration. These individuals have also been found to be relatively free of microvascular complications
Grassland Resources and Protections in the Yellow River Source Zone on the Qinghai-Tibet Plateau
This paper summarises resources and protections of the Yellow River Source Zone on the Qinghai-Tibet Plateau. A concerted effort has been made to address concerns for overgrazing on the alpine steppe and alpine meadow landscapes in the source zone of the Yellow River. An assessment of the impacts of overgrazing includes consideration of the role of small mammals (on the one hand they are considered as a critical ecosystem engineer, on the other they are perceived as a major threatening pest). Analyzed in this paper are management options in the restoration of degraded grasslands
Effect of Omega-3 Fatty Acids on Lipoprotein Profile and Particle Size in Hispanic Women
The effect of increased Ω3 fatty acids on lipoprotein sub-fractions has not been well studied in Hispanic women, a group with a high prevalence of dyslipidemia and metabolic syndrome. The purpose of this randomized, placebo-controlled trial was to examine the effect of a 90-day (90D) combined EPA+DHA supplementation on lipoprotein profiles of Hispanic women. Twenty-seven non-diabetic women were randomly assigned to the Ω3 group (n=17, 1.9 g/day EPA+DHA) or the placebo group (n=10, 2 g/day oleic acid). At baseline (0D) and 90D a fasting blood sample was drawn for determination of lipoprotein profile and lipoprotein particle sub-fractions. For the Ω3 group, total cholesterol increased 6.5%, triglycerides were reduced 14.8%, LDL concentration increased 5.6%, and total LDL particle size concentration increased 8.2% (P \u3c 0.05). Large LDL particle size concentration increased 16% from 0D to 90D, this change was not significant (P = 0.051). At 90D, total cholesterol, LDLs, and LDL particle concentration were higher in the Ω3 group compared to placebo (P \u3c 0.05). Omega-3 supplementation resulted in reduced plasma TGs and an increase in large LDL particle size concentration, yet had no effect on HDL particle size or concentration. Further research is necessary to examine the effects of increased Ω3 fatty acid intake in Hispanic women on dyslipidemia and related co-morbidities
Improvement of Insulin Sensitivity by Isoenergy High Carbohydrate Traditional Asian Diet: A Randomized Controlled Pilot Feasibility Study
The prevalence of diabetes is rising dramatically among Asians, with increased consumption of the typical Western diet as one possible cause. We explored the metabolic responses in East Asian Americans (AA) and Caucasian Americans (CA) when transitioning from a traditional Asian diet (TAD) to a typical Western diet (TWD), which has not been reported before. This 16-week randomized control pilot feasibility study, included 28AA and 22CA who were at risk of developing type 2 diabetes. Eight weeks of TAD were provided to all participants, followed by 8 weeks of isoenergy TWD (intervention) or TAD (control). Anthropometric measures, lipid profile, insulin resistance and inflammatory markers were assessed. While on TAD, both AA and CA improved in insulin AUC (â960.2 ”U/mLĂh, P = 0.001) and reduced in weight (â1.6 kg; P<0.001), body fat (â1.7%, P<0.001) and trunk fat (â2.2%, P<0.001). Comparing changes from TAD to TWD, AA had a smaller weight gain (â1.8 to 0.3 kg, P<0.001) than CA (â1.4 to 0.9 kg, P = 0.001), but a greater increase in insulin AUC (AA: â1402.4 to 606.2 ”U/mLĂh, P = 0.015 vs CA: â466.0 to 223.5 ”U/mLĂh, P = 0.034) and homeostatic static model assessment-insulin resistance (HOMA-IR) (AA: â0.3 to 0.2, P = 0.042 vs CA: â0.1 to 0.0, P = 0.221). Despite efforts to maintain isoenergy state and consumption of similar energy, TAD induced weight loss and improved insulin sensitivity in both groups, while TWD worsened the metabolic profile. Trial Registration: ClinicalTrials.gov NCT0037954
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