Surface code fidelity at finite temperatures

We study the dependence of the fidelity of the surface code in the presence of a single finite-temperature massless bosonic environment after a quantum error correction cycle. The three standard types of environment are considered: super-Ohmic, Ohmic, and sub-Ohmic. Our results show that, for regimes relevant to current experiments, quantum error correction works well even in the presence of environment-induced, long-range inter-qubit interactions. A threshold always exists at finite temperatures, although its temperature dependence is very sensitive to the type of environment. For the super-Ohmic case, the critical coupling constant separating high- from low-fidelity decreases with increasing temperature. For both Ohmic and super-Ohmic cases, the dependence of the critical coupling on temperature is weak. In all cases, the critical coupling is determined by microscopic parameters of the environment. For the sub-Ohmic case, it also depends strongly on the duration of the QEC cycle.Comment: 13 pages, 6 figure

Advanced smoke meter development survey and analysis

Ideal smoke meter characteristics are determined to provide a basis for evaluation of candidate systems. Five promising techniques are analyzed in detail to evaluate compilance with the practical smoke meter requirements. Four of the smoke measurement concepts are optical methods: Modulated Transmission (MODTRAN), Cross Beam Absorption Counter (CBAC), Laser Induced Incandescence (LIN), and Photoacoustic Spectroscopy (PAS). A rapid response filter instrument called a Taper Element Oscillating Microbalance (TEOM) is also evaluated. For each technique, the theoretical principles are described, the expected performance is determined, and the advantages and disadvantages are discussed The expected performance is evaluated against each of the smoke meter specifications, and the key questions for further study are given. The most promising smoke meter technique analyzed was MODTRAN, which is a variation on a direct transmission measurement. The soot-laden gas is passed through a transmission cell, and the gas pressure is modulated by a speaker

Lean Body Mass Index for women ages 18-75 years of age

Purpose: Lean mass is an important component of health because of its multifaceted role in the body. Of particular concern are the effects of muscle mass loss due to aging. Lean mass index (LMI), calculated as lean mass/height2, and fat-free mass index (FFMI) are used to assist in determining a healthy lean mass. The exact FFMI a healthy individual should have to be considered clinically healthy is unclear. Three population-based studies have been done to establish FFMI percentiles, but none were with American subjects. The purpose of this study was to develop LMI percentiles for females of different age groups, to compare the LMI values among these groups, and to compare the FFMI of this cohort to previous studies. Methods: Participants included 762 women, 18 to 75 yrs of age, who had DXA body composition testing at the Fitness Institute of Texas. LMI was calculated for each participant. The women were split into age groups of 18-22 (G1), 23-39 (G2), and 40+ (G3) yrs of age. Cumulative relative frequency was used to determine the LMI percentiles for each group and a univariate ANOVA was used to compare the LMI of the three groups. FFMI percentiles were developed to compare with previously published studies using age groupings of 18-34 and 35-59 yrs of age. Results: The LMI percentiles for each age group are shown in Figure 1. LMI increased significantly between each age group: G1 (15.2±1.8 kg/ m2) \u3c G2 (15.7±1.9 kg/ m2) \u3c G3 (16.1±2.0 kg/ m2) (

Body Composition and Body Satisfaction in Adult Men and Women

Objective: The purpose of this study was to determine the strongest relationships and predictors of self-perceived weight/body composition dissatisfaction from various body anthropometric measures. Hypotheses were that, 1) men (M) and women (W) with an overall higher percentage of body fat would exhibit greater weight dissatisfaction, and 2) that W would experience a greater dissatisfaction than M. Methods: A convenience cohort of 1404 participants (642 M and 762 W), 18-75 yrs of age (30.6 ± 12.4 yrs), ranked their satisfaction with their weight/body composition on a Likert scale of 1 to 5 (1= very satisfied, 2 = satisfied, 3 = somewhat satisfied/somewhat dissatisfied, 4= dissatisfied, 5 = very dissatisfied). If not satisfied or very satisfied, participants were asked “what would make you satisfied?” Responses included: no choice, gain weight and/or muscle, lose 5-10 lbs., lose 10-15 lbs., lose 15-25 lbs., lose more than 25 lbs., be within recommended BF% range, and other. Their total and regional body composition was then measured using dual-energy x-ray absorptiometry (DXA) at the Fitness Institute of Texas. Results: Spearman correlations were used to compare dissatisfaction ratings and body composition measures. Most body composition variables were significantly correlated (p \u3c 0.01) with dissatisfaction. The highest correlations for W were: total fat mass (FM) (0.60), android FM (0.58), trunk FM (0.58), and BMI (0.58). For M the highest correlations were: android fat% (0.55), android FM (0.55), android mass (0.55), total fat % (0.55) and trunk fat % (0.55). All lean mass measures had the lowest correlation with dissatisfaction for M (0.03 – 0.19) and W (0.18 – 0.28). At all body composition levels, more W than M were dissatisfied with their weight/body composition. Stepwise ordinal regression, with dissatisfaction as the outcome variable and DXA variables as predictors, determined that total fat, BMI and age explained 19.7% of the variation in the dissatisfaction of W, while android fat % and lean arm mass accounted for 16.3% of the variation in M (p \u3c 0.05). Of those dissatisfied, 19.2% of W and 42.5% of M wanted to “gain weight and/or muscle,” while 80.8% of W and 57.5% of M wanted to lose weight. Conclusion: In general, as total or regional body fat increases, so does weight/body composition dissatisfaction. At all levels of body composition, more W than M were dissatisfied with their weight/body composition. Of those dissatisfied, most participants wanted to lose weight instead of gain weight/muscle; however, more W than M want to lose weight, and more M than W want to gain weight/muscle. Body composition measures accounted for only a modest amount of self-perceived dissatisfaction; therefore further research should investigate factors beyond the physical that may better predict body dissatisfaction and better understand body image perceptions to develop individual strategies that encourage the adoption of healthy behaviors that promote an overall better quality of life

Pepsin properties, structure, and its accurate measurement: a narrative review

Pepsin is an aspartate protease that is generated from its proenzyme, pepsinogen by autocatalysis initiated by a fall in pH below 5. Human gastric juice contains eight isoenzymes of pepsin. The peptides released on conversion of pepsinogen to pepsin of which there are potentially five, have been shown to have antimicrobial activity against a wide range of bacteria including Escherichia coli, Pseudomonas and Staphylococcus which have also been shown to have biofilm formation inhibiting properties. The stability in response to changes in pH varies between pepsin and pepsinogen. Pepsinogen is stable up to pH 10, pepsin is only stable to pH just above 7.0 and is completely denatured at pH 8.0. Many diseases of the aerodigestive tract have been linked to reflux and the presence of pepsin. Therefore, the measurement of pepsin in tissue and lavages or in saliva or sputum, could be a good screening tool for the diagnosis of reflux related disease. However, there is no current consensus as to the best methods to measure it or the best time to sample it. For an effective pepsin ELISA, the following is required; a monoclonal/monospecific polyclonal antibody with a good lowest level of detection (LLOD) and sensitivity 1–25 ng/mL (depending on dilution) and an adequate supply of purified human pepsin as a standard for antibody-based assays. If possible, an activity assay for pepsin should also be used as the presence of pepsin protein does not indicate it is capable of damaging activity. Finally, if pepsin is associated with a disease large studies are required to confirm it with multiple samples. This review deals with several studies where pepsin quantitation is attempted, and their measurement techniques assessed

Salivary cortisol differs with age and sex and shows inverse associations with WHR in Swedish women: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Most studies on cortisol have focused on smaller, selected samples. We therefore aimed to sex-specifically study the diurnal cortisol pattern and explore its association with abdominal obesity in a large unselected population.</p> <p>Methods</p> <p>In 2001–2004, 1811 men and women (30–75 years) were randomly selected from the Vara population, south-western Sweden (81% participation rate). Of these, 1671 subjects with full information on basal morning and evening salivary cortisol and anthropometric measurements were included in this cross-sectional study. Differences between groups were examined by general linear model and by logistic and linear regression analyses.</p> <p>Results</p> <p>Morning and Δ-cortisol (morning – evening cortisol) were significantly higher in women than men. In both genders older age was significantly associated with higher levels of all cortisol measures, however, most consistently with evening cortisol. In women only, age-adjusted means of WHR were significantly lower in the highest compared to the lowest quartile of morning cortisol (p = 0.036) and Δ-cortisol (p < 0.001), respectively. Furthermore, when comparing WHR above and below the mean, the age-adjusted OR in women for the lowest quartile of cortisol compared to the highest was 1.5 (1.0–2.2, p = 0.058) for morning cortisol and 1.9 (1.3–2.8) for Δ-cortisol. All findings for Δ-cortisol remained after adjustments for multiple covariates and were also seen in a linear regression analysis (p = 0.003).</p> <p>Conclusion</p> <p>In summary, our findings of generally higher cortisol levels in women than men of all ages are novel and the stronger results seen for Δ-cortisol as opposed to morning cortisol in the association with WHR emphasise the need of studying cortisol variation intra-individually. To our knowledge, the associations in this study have never before been investigated in such a large population sample of both men and women. Our results therefore offer important knowledge on the descriptive characteristics of cortisol in relation to age and gender, and on the impact that associations previously seen between cortisol and abdominal obesity in smaller, selected samples have on a population level.</p

Predictors of Hospitals with Endemic Community-Associated Methicillin-Resistant Staphylococcus aureus

OBJECTIVE: We sought to identify hospital characteristics associated with community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) carriage among inpatients. DESIGN: Prospective cohort study. SETTING: Orange County, California. PARTICIPANTS: Thirty hospitals in a single county. METHODS: We collected clinical MRSA isolates from inpatients in 30 of 31 hospitals in Orange County, California, from October 2008 through April 2010. We characterized isolates by spa typing to identify CA-MRSA strains. Using California’s mandatory hospitalization data set, we identified hospital-level predictors of CA-MRSA isolation. RESULTS: CA-MRSA strains represented 1,033 (46%) of 2,246 of MRSA isolates. By hospital, the median percentage of CA-MRSA isolates was 46% (range, 14%–81%). In multivariate models, CA-MRSA isolation was associated with smaller hospitals (odds ratio [OR], 0.97, or 3% decreased odds of CA-MRSA isolation per 1,000 annual admissions; P < .001), hospitals with more Medicaid-insured patients (OR, 1.2; P = .002), and hospitals with more patients with low comorbidity scores (OR, 1.3; P < .001). Results were similar when restricted to isolates from patients with hospital-onset infection. CONCLUSIONS: Among 30 hospitals, CA-MRSA comprised nearly half of MRSA isolates. There was substantial variability in CA-MRSA penetration across hospitals, with more CA-MRSA in smaller hospitals with healthier but socially disadvantaged patient populations. Additional research is needed to determine whether infection control strategies can be successful in targeting CA-MRSA influx