A toolkit for characterizing uncertainties in hypersonic flow-induced ablation

textA one-dimensional, quasi-steady ablation model with finite rate surface chemistry and frozen equilibrium pyrolysis gases is developed and discussed. This material response model is then coupled to a film-transfer boundary layer model to enable the computation of heat and mass transfer to and from the ablating surface. A shock model is outlined, as well, and all three components are then coupled together to form a stand-alone ablation code. The coupled models in the code are validated with respect to arcjet experiments, and comparisons are drawn between the ablation code and the unsteady ablation code Chaleur, as well as other computations for a graphite ablator in an arcjet. The coupled code is found to compare very well to both the experimental results and the other calculations. It is also found to have unique computational capabilities due to the use of finite-rate surface chemistry. Finally, uncertainty propagation using the quadrature method of moments (QMOM) is discussed. The method is applied to a number of simplified sample problems, for both univariate and multivariate scenarios. QMOM is then used to compute the uncertainty in an application of the coupled ablation code using a graphite ablator. The results of this study are discussed, and conclusions about the utility of the method as well as the properties of the ablation code are drawn.Mechanical Engineerin

Concurrent Validity of the Sahara Portable Bone Sonometer

Osteoporosis is a contemporary health issue in today’s society. Bone mineral density tests have the ability to detect low bone density before a fracture occurs. Presently, dual-energy X-ray absorptiometry (DXA) is a common method used to measure bone mineral density. In recent years, quantitative ultrasonography (ultrasound) has been used as a screening device at health fairs and other venues to estimate bone mineral density. The use of ultrasound offers several advantages: it exposes individuals to no radiation, it is inexpensive, and requires less tester skill and oversight than DXA. PURPOSE: To assess the accuracy of calcaneal ultrasound as a bone mineral density screening method compared to total body dual-energy X-ray absorptiometry. METHODS: A total of 44 men between the ages of 18-25 years (21.6 ± 1.41) completed both a total body dual-energy X-ray absorptiometry (DXA) (GE Lunar) scan and an ultrasound (Hologic Sahara) calcaneus scan in a single visit. Correlation coefficients were calculated to determine the relationship between the two devices. Independent sample t-tests were used to determine if the two devices produced significantly different raw values. Bland-Altman plots were used to visually display agreement between devices. RESULTS: The ultrasound device had a weak relationship to the DXA (r = 0.514, p \u3c 0.01). Comparing the absolute agreement between the two devices, the ultrasound device was consistently conservative. It provided mean values of 0.689g/cm2 less than the DXA. It produced values significantly lower (1.31± 0.13 g/cm2 vs. 0.62 ± 0.14 g/cm2 , p \u3c 0.01). CONCLUSIONS: In this study, the ultrasound device produced values significantly lower than the values produced by the DXA. Ultrasound should not be used for individuals requiring a high degree of precision in their measurement. It could be useful, however, as a field device in the screening and estimating of bone mineral density

Educators\u27 Perspectives on Secondary Education Alternative Placement, Student Recidivism, and Treatment Models

The recidivism rate for disciplinary offenses has increased during the last 8 years in the secondary student population of a sizeable, urban school district in the southwest United States. Recidivism for this district is the act of committing a second disciplinary offense during a single calendar year following completion of a behavior program. Guided by Erikson\u27s theory of social development, this case study was designed to collect a purposeful sample of 21 educators\u27 perceptions of the impact of recidivism on students\u27 education and the effectiveness of treatment models to reduce recidivism. Data were collected from qualitative semi-structured interviews and field notes. Data were coded to identify common themes. Six themes emerged from the analysis: academics vs. discipline, stigmas, mentoring, social pressures, truancy, and loneliness and isolation. The most effective models for reducing recidivism were identified as restorative justice and teaching-family. In addition, educators believed recidivism lowered overall student achievement. The results of this study are of interest to those seeking an understanding of the impact of recidivism on students\u27 education. This study promotes positive social change by suggesting effective practices, models, and treatments that contribute to improved educational environments that support for all students

The Influence of Physical Activity on Monocyte Phenotype on Circulating Platelet-Monocyte Complexes in Overweight/Obese Persons

Elevated platelet-monocyte complexes (PMC) promote atherosclerosis and are associated with cardiovascular disease. It is unknown whether consistent physical activity (PA) decreases circulating PMCs. Additionally, no one has determined the monocyte phenotype most associated with PMCs. Purposes: 1) to examine the influence of PA on PMCs and their association with inflammatory /prothrombotic markers such as C-reactive protein (CRP), L-selectin (LS), platelet factor 4 (PF4), von Willebrand Factor (vWF), and hemoglobin A1C (HbA1c) and 2) to determine the monocyte phenotype most likely to form PMCs. Methods: Thirty-one overweight/obese subjects (44±5yr, BMI 34.2±5 kg×m2) were divided into two groups: sedentary (SED, n=17) and physically active (PA, n=14) based on physical activity logs. SED participated in \u3c 1 h of formal exercise while PA participated in moderate-high intensity exercise at least 3 h per week. Flow cytometry was used to identify PMCs on the monocyte phenotypes: classical (CD14+CD16-), intermediate (CD14+CD16+), and non-classical (CD14+CD16++). Platelets were identified using the marker CD42a. Results: Percentage of circulating PMCs and median fluorescence intensity of CD42a (MedFI; marker of platelet density per monocyte) were not different between groups; however, monocyte phenotype significantly impacted PMC percentage and MedFI where the lower the CD16 expression, the greater the adhesion of platelets. Classical monocytes (CD16-) had the highest % of PMC, etc. (Fig 1). HbA1c was greater (p=0.031) and LS (p=0.019) was lower in SED compared to PA (Fig. 2). There were no significant associations between any blood marker and PMC percentage, but PF4 was correlated with percent of CD16 -(r= -0.482, p=0.031) and CD16+(r= 0.473, p=0.035) monocytes. Conclusions: The absence of a separation between groups in VO2max may partially explain the lack of a difference in PMCs between groups. Regarding our second aim, classical monocytes appear to be more involved in PMC formation than do CD16+ monocytes with CD16++ having the lowest percentage of cells with platelets adhered (PMC). This observation may be due to the shedding of adhesion molecules from platelets and monocytes during activation from classical (CD16-) to a more inflammatory state (ie. CD16+)

Use of magnetic source imaging to assess recovery after severe traumatic brain injury—an MEG pilot study

RationaleSevere TBI (sTBI) is a devastating neurological injury that comprises a significant global trauma burden. Early comprehensive neurocritical care and rehabilitation improve outcomes for such patients, although better diagnostic and prognostic tools are necessary to guide personalized treatment plans.MethodsIn this study, we explored the feasibility of conducting resting state magnetoencephalography (MEG) in a case series of sTBI patients acutely after injury (~7 days), and then about 1.5 and 8 months after injury. Synthetic aperture magnetometry (SAM) was utilized to localize source power in the canonical frequency bands of delta, theta, alpha, beta, and gamma, as well as DC–80 Hz.ResultsAt the first scan, SAM source maps revealed zones of hypofunction, islands of preserved activity, and hemispheric asymmetry across bandwidths, with markedly reduced power on the side of injury for each patient. GCS scores improved at scan 2 and by scan 3 the patients were ambulatory. The SAM maps for scans 2 and 3 varied, with most patients showing increasing power over time, especially in gamma, but a continued reduction in power in damaged areas and hemispheric asymmetry and/or relative diminishment in power at the site of injury. At the group level for scan 1, there was a large excess of neural generators operating within the delta band relative to control participants, while the number of neural generators for beta and gamma were significantly reduced. At scan 2 there was increased beta power relative to controls. At scan 3 there was increased group-wise delta power in comparison to controls.ConclusionIn summary, this pilot study shows that MEG can be safely used to monitor and track the recovery of brain function in patients with severe TBI as well as to identify patient-specific regions of decreased or altered brain function. Such MEG maps of brain function may be used in the future to tailor patient-specific rehabilitation plans to target regions of altered spectral power with neurostimulation and other treatments

Characterizing Long COVID: Deep Phenotype of a Complex Condition.

BACKGROUND: Numerous publications describe the clinical manifestations of post-acute sequelae of SARS-CoV-2 (PASC or long COVID ), but they are difficult to integrate because of heterogeneous methods and the lack of a standard for denoting the many phenotypic manifestations. Patient-led studies are of particular importance for understanding the natural history of COVID-19, but integration is hampered because they often use different terms to describe the same symptom or condition. This significant disparity in patient versus clinical characterization motivated the proposed ontological approach to specifying manifestations, which will improve capture and integration of future long COVID studies. METHODS: The Human Phenotype Ontology (HPO) is a widely used standard for exchange and analysis of phenotypic abnormalities in human disease but has not yet been applied to the analysis of COVID-19. FINDINGS: We identified 303 articles published before April 29, 2021, curated 59 relevant manuscripts that described clinical manifestations in 81 cohorts three weeks or more following acute COVID-19, and mapped 287 unique clinical findings to HPO terms. We present layperson synonyms and definitions that can be used to link patient self-report questionnaires to standard medical terminology. Long COVID clinical manifestations are not assessed consistently across studies, and most manifestations have been reported with a wide range of synonyms by different authors. Across at least 10 cohorts, authors reported 31 unique clinical features corresponding to HPO terms; the most commonly reported feature was Fatigue (median 45.1%) and the least commonly reported was Nausea (median 3.9%), but the reported percentages varied widely between studies. INTERPRETATION: Translating long COVID manifestations into computable HPO terms will improve analysis, data capture, and classification of long COVID patients. If researchers, clinicians, and patients share a common language, then studies can be compared/pooled more effectively. Furthermore, mapping lay terminology to HPO will help patients assist clinicians and researchers in creating phenotypic characterizations that are computationally accessible, thereby improving the stratification, diagnosis, and treatment of long COVID. FUNDING: U24TR002306; UL1TR001439; P30AG024832; GBMF4552; R01HG010067; UL1TR002535; K23HL128909; UL1TR002389; K99GM145411

Fluctuations in Blood Biomarkers of Head Trauma in NCAA Men’s Soccer Athletes over the Course of a Season

Repetitive subconcussive impacts to the head are commonplace in soccer. The ability to detect the extent of neurological injury due to these impacts over the course of a season is paramount. PURPOSE: The purpose of the current study was to examine alterations in blood biomarkers of head injury over the course of a soccer season. METHODS: Sixteen National Collegiate Athletic Association (NCAA) male soccer athletes participated in weekly blood sampling throughout an 18-week season. Athlete statistics were received from the coaches post-season. Serum samples were stored at -80°C until analysis for Tau and Neurofilament Light polypeptide (NFL) using a QuanterixTM Simoa HD-1 analyzer. We used R statistical language and the lme4 statistical package to perform a linear mixed effects analysis of the relationships of minutes played (MP) and headers (HEAD) with Tau and NFL. We included the intercept for subjects as a random effect, and time point (TP), MP and HEAD (without the interaction term) as fixed effects. P-values for model comparisons were obtained by likelihood ratio tests. RESULTS: NFL was significantly elevated in weeks 5 (7.3±2.8pg/mL; pCONCLUSION: In our study, neither MP nor HEAD were significant predictors for Tau concentration over the course of an NCAA Men’s soccer season. HEAD appeared to have a small predictive effect on NFL concentrations across the season. Research reported in this publication was supported (in part) by the National Institute on Aging of the National Institutes of Health under Award Numbers R01AG051848, R01AG058537, and R01AG058252. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health

Probiotic Streptococcus thermophilus FP4 and Bifidobacterium breve BR03 Supplementation Attenuates Performance and Range-of-Motion Decrements Following Muscle Damaging Exercise

Probiotics have immunomodulatory effects. However, little is known about the potential benefit of probiotics on the inflammation subsequent to strenuous exercise. In a double-blind, randomized, placebo controlled, crossover design separated by a 21-day washout, 15 healthy resistance-trained men ingested an encapsulated probiotic Streptococcus (S.) thermophilus FP4 and Bifidobacterium (B.) breve BR03 at 5 bn live cells (AFU) concentration each, or a placebo, daily for 3 weeks prior to muscle-damaging exercise (ClinicalTrials.gov NCT02520583). Isometric strength, muscle soreness, range of motion and girth, and blood interleukin-6 (IL-6) and creatine kinase (CK) concentrations were measured from pre- to 72 h post-exercise. Statistical analysis was via mixed models and magnitude-based inference to the standardized difference. Probiotic supplementation resulted in an overall decrease in circulating IL-6, which was sustained to 48 h post-exercise. In addition, probiotic supplementation likely enhanced isometric average peak torque production at 24 to 72 h into the recovery period following exercise (probiotic–placebo point effect ±90% CI: 24 h, 11% ± 7%; 48 h, 12% ± 18%; 72 h, 8% ± 8%). Probiotics also likely moderately increased resting arm angle at 24 h (2.4% ± 2.0%) and 48 h (1.9% ± 1.9%) following exercise, but effects on soreness and flexed arm angle and CK were unclear. These data suggest that dietary supplementation with probiotic strains S. thermophilus FP4 and B. breve BR03 attenuates performance decrements and muscle tension in the days following muscle-damaging exercise