Long-term variations in abundance and distribution of sulfuric acid vapor in the Venus atmosphere inferred from Pioneer Venus and Magellan radio occultation studies

Radio occultation experiments have been used to study various properties of planetary atmospheres, including pressure and temperature profiles, and the abundance profiles of absorbing constituents in those planetary atmospheres. However, the reduction of amplitude data from such experiments to determine abundance profiles requires the application of the inverse Abel transform (IAT) and numerical differentiation of experimental data. These two operations preferentially amplify measurement errors above the true signal underlying the data. A new technique for processing radio occultation data has been developed that greatly reduces the errors in the derived absorptivity and abundance profiles. This technique has been applied to datasets acquired from Pioneer Venus Orbiter radio occultation studies and more recently to experiments conducted with the Magellan spacecraft. While primarily designed for radar studies of the Venus surface, the high radiated power (EIRP) from the Magellan spacecraft makes it an ideal transmitter for measuring the refractivity and absorptivity of the Venus atmosphere by such experiments. The longevity of the Pioneer Venus Orbiter has made it possible to study long-term changes in the abundance and distribution of sulfuric acid vapor, H2SO4(g), in the Venus atmosphere between 1979 and 1992. The abundance of H2SO4(g) can be inferred from vertical profiles of 13-cm absorptivity profiles retrieved from radio occultation experiments. Data from 1979 and 1986-87 suggest that the abundance of H2SO4(g) at latitudes northward of 70 deg decreased over this time period. This change may be due to a period of active volcanism in the late 1970s followed by a relative quiescent period, or some other dynamic process in the Venus atmosphere. While the cause is not certain, such changes must be incorporated into dynamic models of the Venus atmosphere. Potentially, the Magellan spacecraft will extend the results of Pioneer Venus Orbiter and allow the continued monitoring of the abundance of distribution of H2SO4(g) in the Venus atmosphere, as well as other interesting atmospheric properties. Without such measurements it will be difficult to address other issues such as the short-term spatial variability of the abundance of H2SO4(g) at similar latitudes in Venus atmosphere, and the identities of particles responsible for large-scale variations observed in NIR images

Glomerular distribution of type IV collagen in diabetes by high resolution quantitative immunochemistry

Glomerular distribution of type IV collagen in diabetes by high resolution quantitative immunochemistry. We examined type IV collagen distribution and density in human diabetic kidneys by quantitative immunogold electron microscopy. We studied normal kidney transplant donors and “slow-track” and “fast-track” insulin dependent diabetic (IDDM) patients. The “slow-track” patients had IDDM for ≥ 20 years and mesangial volume fraction (VvMes/glom) of ≤ 0.32. The “fast-track” patients had IDDM for ≤ 20 years and VvMes/glom ≥ 0.37. Renal biopsies were embedded in Lowicryl, reacted with polyclonal anti-type IV collagen (in the distribution of the classical α1(IV) and α2(IV) collagen chains) and monoclonal anti-α4(IV) collagen chain antibody followed by gold conjugated secondary antibody. We found, by morphometric techniques, a decrease in the immunogold densities of anti-type IV collagen in the subendothelial zone of the GBM in the “fast-track” IDDM patients. There was a trend towards a decrease in mesangial matrix (MM) particle density in the “fast-track” (P = 0.07) but not in the “slow-track” patients. However, because of the marked increase in MM in the “fast-track” patients, the per glomerulus estimated quantity of these antigens in MM was increased. In contrast, the density of α4(IV) collagen chain was increased in the epithelial zone of the GBM in the “fast-track” IDDM patients. It is not known whether these changes in glomerular type IV collagen represent markers of advanced diabetic lesions or whether these changes might be detected earlier in diabetic patients destined for the later development of serious lesions

Comparison of X-Ray, Millimeter Wave, Shearography and Through-Transmission Ultrasonic Methods for Inspection of Honeycomb Composites

Honeycomb composites are increasingly finding utility in a variety of environments and applications, such as aircraft structural components, flight control components, radomes, etc. In-service and environmental stresses can produce unwanted flaws that adversely affect the structural integrity and functionality of these composites. These flaws may be in the forms of disbonds, delaminations, impact damage, crushed honeycomb, moisture intrusion, internal cracks, etc. There are several nondestructive testing (NDT) methods that may be used to inspect these composites for the presence and evaluation of these flaws. Such NDT methods include X-ray computed tomography, near-field millimeter wave, shearography, and ultrasonic testing. To assess the capabilities of these methods for honeycomb composite inspection, two honeycomb composites panels were produced with several embedded flaws and missing material primarily representing planar disbonds at various levels within the thickness of the panels and with different shapes. Subsequently, the aforementioned NDT methods were used to produce images of the two panels. This paper presents the results of these investigations and a comparison among the capabilities of these methods

Too Much Glucagon, Too Little Insulin: Time course of pancreatic islet dysfunction in new-onset type 1 diabetes

OBJECTIVE—To determine the time course of changes in glucagon and insulin secretion in children with recently diagnosed type 1 diabetes

Serum Adiponectin is Associated with Adverse Outcomes of Asthma in Men but Not in Women

Background: Murine studies suggest a beneficial effect of systemic adiponectin on asthma. Our objective was to determine the association between serum adiponectin concentrations and asthma control/severity outcomes in men and women separately. Methods: Cross-sectional and longitudinal analyses of data from years 10, 15, and 20 examinations of the prospective coronary artery risk development in young adults study in the United States were performed. Asthma was defined by self-reported provider diagnosis at or prior to year 15 examination. Outcomes included presence of active disease, number of respiratory symptoms, and number of asthma medications; as well as longitudinal decline in absolute FEV1. Year 15 serum adiponectin concentration was the predictor variable. Results: In a multivariable analysis of 411 eligible subjects, after adjusting for body mass index and covariates, higher serum adiponectin concentrations were associated with more frequent active disease (including more frequent use of any asthma medication), and greater number of respiratory symptoms and asthma medications among men but not among women with asthma (p for interactions between sex and adiponectin for all analyses < 0.05). Conclusions: Higher serum adiponectin concentrations may be independently associated with adverse clinical outcomes of asthma in men but not in women. If biological effect is confirmed in future studies, modification of systemic adiponectin concentrations may open up newer ways to treat asthma in men

Disparity Outcomes in Patients Undergoing Pancreas Surgery at an Urban Tertiary Care Center

INTRODUCTION: Previous studies have shown significant disparities in pancreas cancer outcomes in African American (AA) compared to non-AA patients. Pancreas surgery continues to be associated with significant morbidity, however, there is little reported data on pancreas surgical outcomes by race. We sought to evaluate how race would affect surgical outcomes in an urban tertiary care center for patients undergoing pancreas surgery. METHODS: A retrospective single-center analysis of patients undergoing pancreas surgery between January 2013 and September 2021 was performed. Patient demographics and post-surgical complications were collected and stratified by race. Area Deprivation Index (ADI) was used to determine patient socioeconomic status. Charlson Comorbidity Index (CCI) was calculated for comorbidities. Clavien-Dindo (CD) complications, as well as postoperative pancreatic fistula (POPF), delayed gastric emptying (DGE) and postpancreatectomy hemorrhage (PPH) were evaluated. Patient reoperation, readmission, and mortality in the 30- and 90- day period were collected and univariate and multivariate analyses were performed. RESULTS: Among 461 patients, 82% (N = 378) were nonAA and 18% (N = 83) were AA. Age and sex were found to be significantly different between the two groups, while ADI and CCI were not. Length of stay (LOS), POPF, PPH, PPH grade C and intra-abdominal abscess (IAA) were found to be significant on univariate analysis in the AA cohort. On multivariate analysis, LOS (OR 4.0; 95% CI 2.0-5.7; p \u3c 0.001), POPF (OR 0.6; 95% CI 0.4-1.0; p = 0.043), PPH (OR 0.5; 95% CI 0.2-0.9; p = 0.022), PPH grade C (OR 0.2; 95% CI 0.1-0.7; p = 0.017) and IAA (OR 0.4; 95% CI 0.2-0.9; p = 0.017) were still significantly higher in the AA cohort. CONCLUSIONS: AA patients undergoing pancreas surgery were noted to have a longer LOS, higher incidence of POPF, PPH and IAA compared to non-AA patients. However, no significant difference was seen in reoperation rates, major CD complications, or 30- and 90-day readmission. Elucidating patient selection, tumor biology, and preoperative treatment algorithms may shed additional insight on the differences in surgical outcomes in this particular patient cohort

Measurement of islet cell antibodies in the Type 1 Diabetes Genetics Consortium: efforts to harmonize procedures among the laboratories

Background and Purpose Three network laboratories measured antibodies to islet autoantigens. Antibodies to glutamic acid decarboxylase (GAD65 [GADA]) and the intracellular portion of protein tyrosine phosphatase (IA-2ic [IA-2A]) were measured by similar, but not identical, methods in samples from participants in the Type 1 Diabetes Genetics Consortium (T1DGC)