56 research outputs found
Luminosity distance in Swiss cheese cosmology with randomized voids. II. Magnification probability distributions
We study the fluctuations in luminosity distances due to gravitational
lensing by large scale (> 35 Mpc) structures, specifically voids and sheets. We
use a simplified "Swiss cheese" model consisting of a \Lambda -CDM
Friedman-Robertson-Walker background in which a number of randomly distributed
non-overlapping spherical regions are replaced by mass compensating comoving
voids, each with a uniform density interior and a thin shell of matter on the
surface. We compute the distribution of magnitude shifts using a variant of the
method of Holz & Wald (1998), which includes the effect of lensing shear. The
standard deviation of this distribution is ~ 0.027 magnitudes and the mean is ~
0.003 magnitudes for voids of radius 35 Mpc, sources at redshift z_s=1.0, with
the voids chosen so that 90% of the mass is on the shell today. The standard
deviation varies from 0.005 to 0.06 magnitudes as we vary the void size, source
redshift, and fraction of mass on the shells today. If the shell walls are
given a finite thickness of ~ 1 Mpc, the standard deviation is reduced to ~
0.013 magnitudes. This standard deviation due to voids is a factor ~ 3 smaller
than that due to galaxy scale structures. We summarize our results in terms of
a fitting formula that is accurate to ~ 20%, and also build a simplified
analytic model that reproduces our results to within ~ 30%. Our model also
allows us to explore the domain of validity of weak lensing theory for voids.
We find that for 35 Mpc voids, corrections to the dispersion due to lens-lens
coupling are of order ~ 4%, and corrections to due shear are ~ 3%. Finally, we
estimate the bias due to source-lens clustering in our model to be negligible
Development and comparison of a minimally-invasive model of autologous clot pulmonary embolism in Sprague-Dawley and Copenhagen rats
Background
Experimental models of pulmonary embolism (PE) that produce pulmonary hypertension (PH) employ many different methods of inducing acute pulmonary occlusion. Many of these models induce PE with intravenous injection of exogenous impervious objects that may not completely reproduce the physiological properties of autologous thromboembolism. Current literature lacks a simple, well-described rat model of autlogous PE. Objective: Test if moderate-severity autologous PE in Sprague-Dawley (SD) and Copenhagen (Cop) rats can produce persistent PH.
Methods
blood was withdrawn from the jugular vein, treated with thrombin-Ca++ and re-injected following pretreatment with tranexamic acid. Hemodynamic values, clot weights and biochemical measurements were performed at 1 and 5 days.
Results
Infusion of clot significantly increased the right ventricular peak systolic pressure to 45-55 mm Hg, followed by normalization within 24 hours in SD rats, and within 5 days in COP rats. Clot lysis was 95% (24 hours) and 97% (5 days) in SD rats and was significantly lower in COP rats (70%, 24 hours; 87% 5 days). Plasma D-dimer was elevated in surgical sham animals and was further increased 8 hours after pulmonary embolism. Neither strain showed a significant increase in bronchoalveolar chemotactic activity, myeloperoxidase activity, leukocyte infiltration, or chemokine accumulation, indicating that there was no significant pulmonary inflammation.
Conclusions
Both SD and COP rats exhibited near complete fibrinolysis of autologous clot PE within 5 days. Neither strain developed persistent PH. Experimental models of PE designed to induce sustained PH and a robust inflammatory response appear to require significant, persistent pulmonary vascular occlusion
2019 American College of Rheumatology/Arthritis Foundation Guideline for the Management of Osteoarthritis of the Hand, Hip, and Knee
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153772/1/acr24131.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153772/2/acr24131_am.pd
Development and comparison of a minimally-invasive model of autologous clot pulmonary embolism in Sprague-Dawley and Copenhagen rats
Abstract Background Experimental models of pulmonary embolism (PE) that produce pulmonary hypertension (PH) employ many different methods of inducing acute pulmonary occlusion. Many of these models induce PE with intravenous injection of exogenous impervious objects that may not completely reproduce the physiological properties of autologous thromboembolism. Current literature lacks a simple, well-described rat model of autlogous PE. Objective: Test if moderate-severity autologous PE in Sprague-Dawley (SD) and Copenhagen (Cop) rats can produce persistent PH. Methods blood was withdrawn from the jugular vein, treated with thrombin-Ca++ and re-injected following pretreatment with tranexamic acid. Hemodynamic values, clot weights and biochemical measurements were performed at 1 and 5 days. Results Infusion of clot significantly increased the right ventricular peak systolic pressure to 45-55 mm Hg, followed by normalization within 24 hours in SD rats, and within 5 days in COP rats. Clot lysis was 95% (24 hours) and 97% (5 days) in SD rats and was significantly lower in COP rats (70%, 24 hours; 87% 5 days). Plasma D-dimer was elevated in surgical sham animals and was further increased 8 hours after pulmonary embolism. Neither strain showed a significant increase in bronchoalveolar chemotactic activity, myeloperoxidase activity, leukocyte infiltration, or chemokine accumulation, indicating that there was no significant pulmonary inflammation. Conclusions Both SD and COP rats exhibited near complete fibrinolysis of autologous clot PE within 5 days. Neither strain developed persistent PH. Experimental models of PE designed to induce sustained PH and a robust inflammatory response appear to require significant, persistent pulmonary vascular occlusion.</p
Decrease in Glycemic Index Associated with Improved Glycemic Control among Latinos with Type 2 Diabetes
BACKGROUND: Glycemic index and glycemic load are used to facilitate glucose control among adults with type 2 diabetes, with a low glycemic index diet associated with improved glycemic control.
OBJECTIVE: To examine long-term longitudinal associations between changes in glycemic index and glycemic load with glycemic and metabolic control among Latino adults with diabetes.
DESIGN: Secondary data from intervention and comparison participants in the Latinos en Control trial (2006 to 2008) were analyzed.
PARTICIPANTS/SETTING: Data on dietary intake and metabolic characteristics were from low-income, Latino adults (N = 238; 87.7% Puerto Rican) with type 2 diabetes.
INTERVENTION: The Latinos en Control trial was a randomized clinical trial targeting diabetes self-management among Latinos with type 2 diabetes. Participants were randomized to a group-based behavioral intervention or usual care and followed through 12 months.
MAIN OUTCOME MEASURES: Outcomes included hemoglobin A1c (HbA1c) levels, fasting blood glucose, lipid profiles, anthropometrics, and blood pressure.
STATISTICAL ANALYSIS: Glycemic index and load were analyzed using data from three 24-hour dietary recalls conducted at baseline, 4 months, and 12 months. Repeated measures regression models were used to examine change in glycemic index and load associated with metabolic characteristics at 12 months. Covariates included sex, age, body mass index, blood pressure, total energy intake, medication use and intensity, physical activity, intervention status (intervention vs usual care), and time.
RESULTS: Increases in glycemic index from baseline to 12 months were associated with increased logarithm of HbA1c levels (beta = 0.003; P = 0.034) and waist circumference (beta = 0.12; P = 0.026) over time, but not with fasting glucose, blood lipids, or body mass index. There was modest evidence to support small, positive associations between glycemic load and HbA1c levels and waist circumference.
CONCLUSIONS: Lowering glycemic index is associated with improvements in certain metabolic risk factors among Latinos with diabetes. Targeting glycemic index may be an important component of dietary strategies for diabetes self-management. All rights reserved
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