Studies of helium gas mixtures in drift chambers
Nuclear instruments and methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment/Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/1992
Journal Article
The results of the three experiments provide insight into the time/motion characteristics of racquetball and the physiological responses of elite-level racquetball players during competition. The ...maximum oxygen uptakes of the male and female athletes tested were relatively low in comparison to those of other elite-level sports, suggesting that aerobic demand, although necessary, is probably not a limiting factor at this level of racquetball play. Racquetball games at the elite level last from 10 to 15 min, and the distance covered by each player during this time is minimal. Even though the rest periods between rallies are from one to two times as long as the work intervals, the work intensity during the rallies is sufficient to produce an average heart rate of between 75 and 95% of maximum throughout most of a game. Although some lactic acid accumulates in the blood, the concentration remains at a steady state during a game (10 to 30% of maximum).
Many techniques for increasing the amount of instruction-level parallelism (ILP) put increased pressure on the registers inside a CPU. These techniques allow for more operations to occur ...simultaneously at the cost of requiring more registers to hold the operands and results of those operations, and importantly, more ports on the register banks to allow for concurrent access to the data. One approach of ameliorating the number of ports on a register bank (the cost of ports in gates varies as N/sup 2/ where N is the number of ports, and adding ports increases access time) is to have multiple register banks with fewer ports, each attached to a subset of the available functional units. This reduces the number of ports needed on a per-bank basis, but can slow operations if a necessary value is not in an attached register bank as copy operations must be inserted. Therefore, there is a circular dependence between assigning operations to functional units and assigning values to register banks. We describe an approach that produces good code by separating partitioning from scheduling and register assignment. Our method is independent of both the scheduling technique and register assignment method used.
Biologists have long recognized the dangers of the lack of diversity or monocultures in biological systems. Recently, it has been noted that much of the fragility of our networked computing systems ...can be attributed to the lack of diversity or monoculture of our software systems. The problem is severe. Because it is virtually inevitable that software will ship with flaws, our software monoculture leaves systems open to large-scale attacks by knowledgeable adversaries. Inspired by the resilience of diverse biological systems, the authors developed the genesis software development toolchain. An innovative aspect of genesis is the use of an application-level virtual machine technology that enables the application of diversity transforms at any point in the software toolchain. Using Genesis, they authors demonstrated that diversity, when judiciously applied, is a practical and effective defense against two widely used types of attacks - return-to-libc and code injection.
Cervical cancer rates in Mississippi are disproportionately high, particularly among Black individuals; yet, research in this population is lacking. We designed a statewide, racially diverse cohort ...of individuals undergoing cervical screening in Mississippi. Here, we report the baseline findings from this study.
We included individuals aged 21 years and older undergoing cervical screening with cytology or cytology-human papillomavirus (HPV) co-testing at the Mississippi State Health Department (MSDH) and the University of Mississippi Medical Center (UMMC) (December 2017–May 2020). We collected discarded cytology specimens for future biomarker testing. Demographics and clinical results were abstracted from electronic medical records and evaluated using descriptive statistics and chi-square tests.
A total of 24,796 individuals were included, with a median age of 34.8 years. The distribution of race in our cohort was 60.2% Black, 26.4% White, 7.5% other, and 5.9% missing. Approximately 15% had abnormal cytology and, among those who underwent co-testing at MSDH (n = 6,377), HPV positivity was 17.4% and did not vary significantly by race. Among HPV positives, Black individuals were significantly less likely to be HPV16/18 positive and more likely to be positive for other high-risk 12 HPV types compared to White individuals (20.5% vs. 27.9%, and 79.5% and 72.1%, respectively, p = 0.011).
Our statewide cohort represents one of the largest racially diverse studies of cervical screening in the U.S. We show a high burden of abnormal cytology and HPV positivity, with significant racial differences in HPV genotype prevalence. Future studies will evaluate cervical precancer risk, HPV genotyping, and novel biomarkers in this population.
•Cervical screening cohort - underrepresented rural and racially diverse population•High prevalence of abnormal cytology and HPV positivity•Significant difference of HPV genotype distribution by race
Background
Mississippi (MS) has among the highest rates of cervical cancer incidence and mortality in the United States, with disproportionately higher rates among Blacks compared to Whites. Here, we ...evaluate the prevalence of high‐risk human papillomavirus (HPV) and abnormal cytology in a representative baseline sample from a diverse statewide cohort of individuals attending cervical screening in MS from the STRIDES Study (STudying Risk to Improve DisparitiES in cervical cancer).
Methods
We included individuals aged 21–65 years undergoing screening at the University of Mississippi Medical Center (UMMC) and the Mississippi State Department of Health (MSDH) from May to November 2018. We calculated age‐specific HPV prevalence, overall and by partial HPV16/18 genotyping, and abnormal cytology by race.
Results
A total of 6871 individuals (mean age 35.7 years) were included. HPV prevalence was 25.6% and higher in Blacks (28.0%) compared to Whites (22.4%). HPV prevalence was significantly higher in Blacks aged 21–24 years (50.2%) and 30–34 years (30.2%) compared to Whites in the same age groups (32.1% and 20.7%; p < 0.0001, respectively). The prevalence of high‐grade cytologic abnormalities, a cytologic sign of cervical precancer, peaked earlier in Blacks (ages 25–29) compared to Whites (35–39). For comparison, we also analyzed HPV prevalence data from the National Health and Nutrition Examination Survey (NHANES, 2013–2016) and observed similar racial differences in HPV prevalence among women aged 21–24 years.
Conclusions
Our findings suggest that Blacks undergoing cervical cancer screening in MS have higher prevalence of other high‐risk 12 HPV types at younger ages and experience an earlier peak of high‐grade cytologic abnormalities compared to Whites.
We evaluated the age‐specific prevalence of human papillomavirus (HPV) and abnormal cytology in a baseline sample from a large, diverse statewide screening cohort in Mississippi. Overall, HPV prevalence was high (25.6%), and varied by race, with Blacks having significantly higher prevalence of other high‐risk 12 HPV types at younger ages compared to Whites, corresponding to an earlier peak of high‐grade cytologic abnormalities.
•We investigate protein unfolding in ion exchange and multi mode chromatography.•Mass spectrometry is used to detect any conformational changes upon adsorption.•Protein unfolding depends on pH and ...surface ligand charge (cationic vs. anionic).•Some, but not all regions of the protein, unfold to varying extents on the surfaces.•Electrostatic interactions drive protein unfolding on a multi mode surface.
Recent studies with proteins indicate that conformational changes and aggregation can occur during ion exchange chromatography (IEC). Such behavior is not usually expected, but could lead to decreased yield and product degradation from both IEC and multi mode chromatography (MMC) that has ligands of both hydrophobic and charged functionalities. In this study, we used hydrogen exchange mass spectrometry to investigate unfolding of the model protein BSA on IEC and MMC surfaces under different solution conditions at 25°C. Increased solvent exposure, indicating greater unfolding relative to that in solution, was found for protein adsorbed on cationic IEC and MMC surfaces in the pH range of 3.0 to 4.5, where BSA has decreased stability in solution. There was no effect of anionic surfaces at pH values in the range from 6.0 to 9.0. Differences of solvent exposure of whole molecules when adsorbed and in solution suggest that adsorbed BSA unfolds at lower pH values and may show aggregation, depending upon pH and the surface type. Measurements on digested peptides showed that classifications of stability can be made for various regions; these are generally retained as pH is changed. When salt was added to MMC systems, where electrostatic interactions would be minimized, less solvent exposure was seen, implying that it is the cationic moieties, rather than the hydrophobic ligands, which cause greater surface unfolding at low salt concentrations. These results suggest that proteins of lower stability may exhibit unfolding and aggregation during IEC and MMC separations, as they can with hydrophobic interaction chromatography.
Motor neuron degeneration and malnutrition alter body composition in amyotrophic lateral sclerosis (ALS). Resulting losses of weight, fat mass (FM), and fat-free mass (FFM) shorten survival. ...Nutritional management relies on body weight or BMI; neither reliably indicates malnutrition nor differentiates body compartments.
We aimed to 1) develop an equation to compute FM and FFM using clinical data, validated against DXA; and 2) examine the effect of computed FM and FFM on disease course and survival.
We studied 364 ALS patients from 3 cohorts. In Cohort #1 we used logistic regression on clinical and demographic data to create an equation (test cohort). In Cohort #2 we validated FM and FFM computed using this equation against DXA (validation cohort). In Cohort #3, we examined the effect of computed body composition on disease course and survival.
In Cohort #1 (n = 29) the model incorporated sex, age, BMI, and bulbar-onset to create an equation to estimate body fat: % body fat = 1.73 – 19.80*gender (1 if male or 0 if female) + 0.25*weight (kg) + 0.95*BMI (kg/m2) − (5.20*1 if bulbar-onset or *0 if limb-onset). In Cohort #2 (n = 104), body composition using this equation, compared to other published equations, showed the least variance from DXA values. In Cohort #3 (n = 314), loss of body composition over 6 mo was greater in males. Adjusted survival was predicted by low baseline FM (HR: 1.39; 95% CI: 1.07, 1.80), and loss of FM (HR: 1.87; 95% CI: 1.30, 2.69) and FFM (HR: 1.73; 95% CI: 1.20, 2.49) over 6 mo.
Our equation broadens the traditional nutritional evaluation in clinics and reliably estimates body composition. Measuring body composition could target FM as a focus for nutritional management to ensure adequate energy intake and complement measures, such as the ALS functional rating scale-revised score and forced vital capacity, currently used.
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