Single Standard Deviation Research Articles

Reliability testing of an IMU-based 2-segment foot model for clinical gait analysis

BackgroundThe one of the most commonly used reference system for clinical gait analysis is an optical motion capture system (OMC) using a multi-segment foot model. A time- and cost-efficient alternative could be an inertial measurement unit (IMU)-based systems. However, these are limited to a single segment approach for the foot and ankle. Therefore, the current setup was modified to be based on a 2-segment foot model, allowing for a separate analysis of the hind- and midfoot. The study aimed to evaluate the reliability (inter-rater, intra-rater, and test-retest reliability) of an IMU-based 2-segment foot model. Material and methodsTwelve healthy subjects were recruited to test the inter-rater, intra-rater, and test-retest reliability of the new IMU based 2-segment foot model. Gait analysis was performed on a treadmill at a constant speed of 4 km/h. Kinematic data of the tibia/hindfoot, tibia/forefoot and hindfoot/forefoot over 100 % gait cycle were analyzed. The reliability was tested by using statistical parametric mapping (SPM) and the intraclass correlation coefficient (ICC). ResultsThe SPM showed no significant difference for inter-, intra-rater, and test-retest reliability, but for a small segment of tibia/forefoot dorsiflexion test-retest reliability (2.1° difference). The single standard deviation measurement error for the sagittal and transverse plane was <5° and worse for the frontal plane. ConclusionThe new 2-segment foot model revealed a high inter-rater, intra-rater, and test-retest reliability. It is suitable for use in adult clinical practice. Still, comparative data to the OMC system using a multi-segment foot model are missing.

Positronium lifetime validation measurements using a long-axial field-of-view positron emission tomography scanner

BackgroundPositron emission tomography (PET) traditionally uses coincident annihilation photons emitted from a positron interacting with an electron to localize cancer within the body. The formation of positronium (Ps), a bonded electron-positron pair, has not been utilized in clinical applications of PET due to the need to detect either the emission of a prompt gamma ray or the decay of higher-order coincident events. Assessment of the lifetime of the formed Ps, however, can potentially yield additional diagnostic information of the surrounding tissue because Ps properties vary due to void size and molecular composition. To assess the feasibility of measuring Ps lifetimes with a PET scanner, experiments were performed in a Biograph Vision Quadra (Siemens Healthineers). Quadra is a long-axial field-of-view (LA-FOV) PET scanner capable of producing list-mode data from single interaction events.ResultsOrtho-Ps (o-Ps) lifetimes were measured for quartz-glass and polycarbonate samples using a 22Na\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{22}\ ext{Na}$$\\end{document} positron source. Results produced o-Ps lifetimes of 1.538 ± 0.036 ns for the quartz glass and 1.927 ± 0.042 ns for the polycarbonate. Both o-Ps lifetimes were determined using a double-exponential fit to the time-difference distribution between the emission of a prompt gamma ray and the annihilation of the correlated positron. The measured values match within a single standard deviation of previously published results. The quartz-glass samples were additional measured with 82Rb\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${^{82}}\ ext{Rb}$$\\end{document}, 68\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{68}$$\\end{document}Ga and 124I\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{124}\ ext{I}$$\\end{document} to validate the lifetime using clinically available sources. A double-exponential fit was initially chosen as a similar methodology to previously published works, however, an exponentially-modified Gaussian distribution fit to each lifetime more-accurately models the data. A Bayesian method was used to estimate the variables of the fit and o-Ps lifetime results are reported using this methodology for the three clinical isotopes: 1.59 ± 0.03 ns for 82Rb\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{82}\ ext{Rb}$$\\end{document}, 1.58 ± 0.07 ns for 68Ga\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{68}\ ext{Ga}$$\\end{document} and 1.62 ± 0.01 ns for 124I\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{124}\ ext{I}$$\\end{document}. The impact of scatter and attenuation on the o-Ps lifetime was also assessed by analyzing a water-filled uniform cylinder (20 ϕ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\phi$$\\end{document}×\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ imes$$\\end{document} 30 cm3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{3}$$\\end{document}) with an added 82Rb\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{82}\ ext{Rb}$$\\end{document} solution. Lifetimes were extracted for various regions of the cylinder and while there is a shape difference in the lifetime due to scatter, the extracted o-Ps lifetime of the water, 1.815 ± 0.013 ns, agrees with previously published results.ConclusionOverall, the methodology presented in this manuscript demonstrates the repeatability of Ps lifetime measurements with clinically available isotopes in a commercially-available LA-FOV PET scanner. This validation work lays the foundation for future in-vivo patient scans with Quadra.

Aging and antioxidants: the impact of dietary carotenoid intakes on soluble klotho levels in aged adults.

The association between dietary carotenoid intake and Soluble Klotho (S-Klotho) levels among the elderly population requires further evaluation. The purpose of this study is to evaluate the relationship between the dietary carotenoid intake and the S-Klotho plasma levels in older adults. Eligible participants aged 60 years or above were selected from the National Health and Nutrition Examination Surveys (NHANES) data, collected between 2007 and 2016. The consumption of carotenoids was determined through two 24-hour dietary recall assessments. Moreover, the S-Klotho levels in the serum were measured using an Enzyme-Linked Immuno-Sorbent Assay (ELISA). A total of 5,056 participants were included in the study having a median total carotenoid intake of 9775.25 μg (95% confidence interval (CI): 8971.30-10579.21) and a median S-Klotho concentration of 815.59 pg/mL (95% CI: 802.59-828.60). The multivariable regression analysis showed that a single standard deviation increase in total carotenoid intake was significantly associated with an 8.40 pg/mL increase in S-Klotho levels (95% CI: 0.48-16.31). When the carotenoids were divided into quartiles, participants in the third ((4963.5μg/day,11662.5μg/day]) and fourth quartiles ((11662.5μg/day,377178μg/day]) showed higher S-Klotho levels compared to those in the first quartile. Among carotenoid subtypes, increased intake of α-carotene, β-carotene, and lutein with zeaxanthin was associated with elevated S-Klotho levels. These observed associations between carotenoid subtypes and S-Klotho levels remained consistent across male participants, having a normal weight, and a moderate physical activity based on stratified analysis. The total carotenoid intake was positively related to plasma levels of S-Klotho in the elderly population, particularly for α-carotene, β-carotene, and lutein with zeaxanthin. However, further research is needed to confirm these findings and explore the underlying mechanisms behind this relationship.

Stable isotope analysis of atmospheric CO2 using a Gasbench II-Cold Trap-IRMS setting.

The measurement of the stable carbon and oxygen isotope ratio of (atmospheric) carbon dioxide (CO2 ) is a useful technique for the investigation and identification of the sources and sinks of the most abundant greenhouse gases by far. For this reason, we are presenting a measuring system here that enables a wide range of users to carry out stable isotope analysis of atmospheric CO2 using off-the-bench hardware and software. The fully automated system uses cryogenic and gas chromatographic separation to analyse CO2 from 12-mL whole air samples and consists of an autosampler, a Gasbench II (GB), a downstream cryo trap and a continuous flow gas interface feeding into a sector field mass spectrometer (GC Pal/GB/Cold Trap/ConFlo IV/DeltaV Plus). The evaluation of the system performance was based on the analysis of samples prepared from eight CO2 sources (four CO2 reference gases and four artificial air tanks). The overall measurement uncertainty (averaged single standard deviation (1σ) of measurement replicates from each CO2 source) in the determination of the carbon and oxygen isotope ratio was 0.04‰ and 0.09‰ (n = 24). Furthermore, we were able to show that the measurement data also allowed for the quantification of the CO2 mole fraction, with a precision of 1.2μmol mol-1 in the analysis range of 400-500 μmol mol-1 . Our protocol provides a detailed description of the measurement set-up and the analysis procedure, how raw data should be evaluated and gives recommendations for sample preparation and sampling to enable a fully automated whole air sample analysis. The quantification limit of CO2 mole fractions and measurement precision for carbon and oxygen isotope ratios of CO2 should meet the requirements of a wide range of users.

Business cycle transmission between France and United Kingdom

PurposeThe literature mostly investigates the business cycle transmission of the United Kingdom (UK) and France as a part of a wider group (e.g. European Exchange Rate Mechanism or G7), despite their historical links and regional significance. Thus, herein paper aims to analyse the inter-dependence of these economies and how a shock from one of them affects the other for the data since 1978 to 2019.Design/methodology/approachIn this paper, first, preliminary statistics were calculated in order to describe the historical relationship between these countries. The econometric part estimates the vector auto-regression model (VAR) to assess the inter-dependence of the economies. VAR model allows further to inspect the impulse response functions that shows the shock dynamics from one country to another. In order to verify if a shock from one of the economies is important to another, the study uses granger causality test.FindingsThe study establishes a strong link between these countries. A business cycle is transmitted significantly between the economies of France and UK, with a single standard deviation shock from France resulting in a long term effect of 0.4% change in gross domestic product (GDP) of UK and 1% vice versa. Additionally changes in GDP of both of the countries significantly Granger-cause change to GDP of the corresponding economy.Originality/valueThis is the first empirical study investigating the business cycle transmission between France and UK and providing a quantitative assessment of their inter-dependence.

Amperometric Measurements by a Novel Aerosol Jet Printed Flexible Sensor for Wearable Applications

In the last years, increasing interest has been addressed on wearable devices for the continuous monitoring of biochemical profiles of patients and athletes. Among various markers, lactate represents one of the most interesting to deepen the knowledge on fatigue processes, in combination with traditional electromyographic features. In this work, we propose a new, low-cost, rapid, and flexible electrochemical amperometric lactate carbon biosensor fabricated by the novel technique of aerosol jet printing (AJP). The developed biosensors were combined with a paper-based microfluidic system and a chitosan-based stable functionalization to allow a long-term continuous monitoring of human daily activities. The sensor performances were evaluated by static and dynamic electrochemical tests in buffered media. The limit of detection is 11 ± 2 mM for the static setup and of 15 ± 6 mM for the dynamic setup, while sensitivity is 0.02 and 0.04 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{A}$ </tex-math></inline-formula> /mM, respectively, with single sigma standard deviation lower than 8%. Increasing and decreasing concentration steps of lactate induces comparable response times below 30 s. These results obtained in vitro under controlled laboratory conditions represent a promising starting point to pursue with ex-vivo and in vivo validation for the future development of stand-alone wearable patches for noninvasive lactate measurements.

A Comparative Study to assess the knowledge on behavioral pattern of single child and a child with siblings between the age group of 6-12 years children of selected areas in Mehsana city

Introduction: A child is a human being between the stages of birth and puberty. Children Behaviour refers to how one conducts themselves. It is their actions, reactions and functioning in response to everyday environments and situations. The term behaviour include Cognitive activity (mental skill (knowledge)), Affective activity (growth in feeling or emotional areas (attitude)), psychomotor activity (manual or physical skill (skills). Design: Comparative descriptive research design, Participinats: Total 100 sample (50- single child and 50 – child with siblings) were selected using non probability convenient sampling technique. Tool: Likert scale Results: Reveals that in single child mean was 50.92 and sibling child mean was 100.86. The single child standard deviation was 27.61 and the sibling child standard deviation was 28.19. The standard error was 5.58 and the obtained t-value was 0.103 which are significant at 0.005 levels. So the researcher concluded that there was a significant difference in behavior pattern between single child and child with sibling. Knowledge level on behaviour pattern was classified as good, average, and poor. In sibling child, 27(54%) had good behavioral pattern, 21(42%) had average behavioral pattern, 02(4%) had poor behavioral pattern. In child with sibling, 08(16%) had good behavioral pattern, 6(12%) had average behavioral pattern, 36(72%) had poor behavioral pattern. Conclusion: Childhood period is important in the life. Many of single child have poor knowledge on behaviour pattern. Parents must realize there problem and mingle with them.

Maritime Traffic Evaluation Using Spatial-Temporal Density Analysis Based on Big AIS Data

For developing national maritime traffic routes through the coastal waters of Korea, the customary maritime traffic flow must be accurately identified and quantitatively evaluated. In this study, the occupancy time of ships in cells was calculated through a density analysis based on automatic identification system data. The density map was statistically created by logarithmically transforming the density values and adopting standard deviation-based stretch visualization to increase the normality of the distribution. Many types of traffic routes such as open-sea, coastal, inland, and coastal access routes were successfully identified; moreover, the stretch color ramp ratio was reduced to identify routes having relatively high density. Adopting a single standard deviation and demonstrating the top 25% of color ramps, the analysis afforded the main routes through which customary traffic flows. This novel density analysis method and statistical visualization method is expected to be used for developing national maritime traffic routes and should ultimately contribute to maritime safety. Moreover, it provides a scientific means and simulator for determining the navigation area and analyzing conflicts with other activities in marine spatial planning.

Health Literacy and Smoking Habits Among a Sample of Jordanian University Students.

Limited health literacy is a significant predictor of engaging in unhealthy behaviors. However, the literature regarding the association between health literacy and smoking in university students is very limited. Thus, this study was conducted to examine the association between university students' health literacy and smoking habits. A cross-sectional design was used. A sample of university students (N = 327) was recruited to conduct this study. Data collection was performed using a demographics questionnaire and the health literacy questionnaire. AMOS was used to conduct data analysis using structural equation modeling analysis with maximum likelihood estimation. Different versions of the structural model were compared and evaluated based on specific fit indices criteria. The results showed that 30% of the participants were current smokers. Smoking cigarettes was the most common type of smoking in this study, and 23.1% of the participants were current users of two or more types of smoking (e.g., cigarettes and hookah). The structural model with three latent variables (health literacy, smoking status and type, and smoking frequency and duration) was the one that best fit the data; the model fit indices were X2 = 305.84, df = 102, p < .001; RMSEA = .068; CFI = .95; CMIN/df = 2.51; TLI = .929; and AIC = 355.75. A single standard deviation increase of health literacy causes .38 decrease in smoking status and type and .13 decrease of smoking frequency and duration. The results showed that health literacy is negatively associated with smoking in a sample of Jordanian university students.

Comparative analysis of patient scatter to phantom scatter for computed tomography systems.

Current computed tomography (CT) shielding practices are largely based on calculations of scattered radiation emitted from an acrylic head or body phantom, such as the Computed Tomography Dose Index (CTDI) phantom, or anthropomorphic phantoms of these two anatomical categories. This report considers the difference in scattered air kerma or dose from phantom models, to actual patient scatter under a variety of clinical scan conditions. Empirical patient scatter measurements recorded at different positions around the gantry, for 3 different CT scanners, resulted in average patient scatter fractions per unit Dose Length Product (DLP: mGycm) at 1m from the isocentre of 0.09 ± 0.03 and 0.17 ± 0.04 µGy (mGycm)-1 for head and body scans respectively. For the purposes of shielding design and scattered dose estimates to staff it is recommended that a single standard deviation be applied to these averages in the continued interest of conservatism. These values are reasonably comparative to the widely published scatter fractions by the National Council of Radiological Protection using the CTDI phantom, and the British Institute of Radiology using head and body anthropomorphic phantoms.

Probabilistic Reserves Categorization Using Percentiles of a Single Probability Distribution

Summary Petroleum reserves assessment is a routine exercise performed by every oil and gas company. The reserves estimation could be achieved using deterministic or probabilistic methods. Depending on the type of data available, different assumptions and data are used at various stages of the assessment throughout the E&amp;P life cycle (i.e., exploration, appraisal, development, depletion, and so on). The accuracy of the reserves estimate is highly dependent on the amount and quality of data available and experience of the evaluator. The estimates become more accurate and refined as more and more data become available. The objective of this paper is to urge the industry to rethink the terminology used for categorizing probabilistic reserves (P90, P50, and P10) using a single probability distribution. As a routine practice, we consider 1P = P90 = proved reserves, 2P = P50 = proved + probable reserves, and 3P = P10 = proved + probable + possible reserves. The reserves categories depend on the range of uncertainty as shown in the Petroleum Resources Classification Framework of the Petroleum Resources Management System (PRMS). It is shown here that P50 (or mean/expected value) of each reserve category is a more robust and logical value to be used for categorizing reserves. The P90 and P10 demonstrate confidence levels of a certain probability distribution, which is owing to the standard deviation (proxy for uncertainty) of the specific distribution and not the range of uncertainty. The range in uncertainty is assessed from varying standard deviations from more than one probability distribution. Therefore, the use of P90 and P10 for reserves categorization contradicts the x-axis title of the Petroleum Resources Classification Framework in the PRMS. The P90, P50, and P10 from a single probability distribution with a single standard deviation will have the same uncertainty (not range of uncertainty). The difference between P90 and P10 is also owing to this single standard deviation. Some examples are presented in this paper to show this and to show that P50 (or mean) with its corresponding standard deviation (indication of uncertainty) could be more appropriately used to book and categorize reserves. The concept of expected value (EV) is also revisited as this may not be correctly reported in some publications.

Effect of preoperative keratometry on visual outcomes after small-incision lenticule extraction for myopia

PurposeTo investigate the relationship between preoperative keratometry (K) and postoperative refraction and compare the visual outcomes after small-incision lenticule extraction (SMILE) between preoperative flat and steep corneas.MethodsThis study involved 814 consecutive eyes of 409 patients who underwent SMILE. A month later, a linear regression analysis of the relationship between preoperative K and the residual spherical equivalent (SE) along with eyes divided by a single standard deviation between flat and steep corneas (< 41.85 D, > 44.57 D, respectively) was conducted. Eyes were distinguished based on the degree of myopia.ResultsOne month after surgery, no significant correlation existed between mean preoperative K and residual SE (P = 0.459). Linear regression analysis showed a weak negative correlation between flat corneas (r2 = 0.042, P = 0.025) rather than steep corneas (P = 0.908). Eyes with preoperative low myopia (< 3.00 D) (r2 = 0.233, P = 0.001) had a weak correlation compared with moderate and high myopia (P = 0.272, P = 0.257, respectively). Twelve months later, the predictability, safety, and efficacy did not vary between preoperative flat and steep corneas (P > 0.05).ConclusionsOne month after SMILE for myopia, the corneas were flatter in the preoperative flat corneas or all the low myopic corneas, and they were more overcorrected. However, preoperative corneal curvature does not influence visual outcomes at 1 year after SMILE.

Mixture Representation Learning for Deep Speaker Embedding

How to effectively convert a sequence of variable-length acoustic features to a fixed-dimension representation has always been a research focus in speaker recognition. In state-of-the-art speaker recognition systems, the conversion is implemented by concatenating the mean and the standard deviation of a sequence of frame-level features. However, a single mean and a single standard deviation are limited descriptive statistics for an acoustic sequence even with powerful feature extractors such as convolutional neural networks. In this paper, we propose a novel statistics pooling method that can produce more descriptive statistics through a mixture representation. Our approach is inspired by the expectation–maximization (EM) algorithm in Gaussian mixture models (GMMs). Instead of using traditional GMM style alignment, we novelly leverage modern deep learning tools to produce a more powerful mixture representation. The novelty includes: (1) unlike GMMs, the mixture assignments are determined by an attention network instead of the Euclidean distances between the frame-level features and explicit centers; (2) instead of using a single frame as input to the attention network, contextual frames are included to smooth out attention transition; and (3) soft-attention assignments are replaced by hard-attention assignments via the Gumbel-Softmax with straight-through estimators. With the proposed attention mechanism, we obtained a 13.7% relative improvement over vanilla mean and standard deviation pooling in the VOiCES19-eval set.

Factors affecting the placement of agricultural best management practices in the agricultural conservation planning framework (ACPF) toolbox in the mid-Atlantic region.

There has been a recent push to conduct spatially explicit landscape planning at finer hydrologic unit scales to mitigate diffuse pollution. The Agricultural Conservation and Planning Framework (ACPF) helps identify potential locations for agricultural conservation practices by using high-resolution soils and elevation data. This spatially explicit approach attempts to identify runoff and nutrient pathways, but output may be influenced by user-specified parameters and the properties of the digital elevation model (DEM) being used. Here we assess differences in the density and location of conservation practices sited by the ACPF toolbox across three DEM resolutions in three agricultural catchments, each in distinct physiographies (Ridge and Valley, Piedmont, Coastal Plain) of the United States mid-Atlantic region. Output frequency did not vary much for contour buffer strips or water and sediment control basins (WASCOBs) across DEM resolution, particularly compared with landscape type. The DEM resolution was crucial for the density of grassed waterways but of little consequence for contour buffer strips. Placement density of WASCOBs and contour buffer strips varied by region. Grassed waterways are sited based on either discrete values or statistical distributions of stream power index (SPI). A higher density of grassed waterways was placed in lower relief landscapes when a single standard deviation threshold was applied. Using discrete SPI values for the grassed waterway tool generated more consistent output across watersheds than output based on statistical distributions. These and other reported findings can help guide user decisions in future applications of the ACPF toolbox, particularly across different areas of study.

Lagrangian analysis of enstrophy dynamics in a highly turbulent premixed flame

A Lagrangian analysis approach is used to examine the effects of heat release on the dynamics of the enstrophy during highly turbulent premixed combustion. The analysis is performed using data from a direct numerical simulation of a statistically planar premixed methane–air flame at a Karlovitz number of 100. Through cumulative, conditional, and correlation analyses, we show, consistent with prior studies, that vortex stretching and baroclinic torque both increase enstrophy at these highly turbulent conditions, while viscous transport and dilatation both lead to enstrophy destruction. However, although vortex stretching and viscous transport are individually an order of magnitude greater than all other terms in the enstrophy budget, the cumulative and combined effect of these two terms along Lagrangian trajectories is roughly only twice as large as the combined cumulative effect of dilatation and baroclinic torque. Moreover, trajectories that exhibit an increase in enstrophy through the flame are found to frequently have cumulative contributions from budget terms outside a single standard deviation of the mean contribution, indicating that enstrophy production at such highly turbulent conditions is associated with relatively infrequent but large values of dynamical terms. Lagged correlations further reveal a small but measurable contribution of baroclinic torque in enstrophy production, but these increases are overwhelmed, on average, by concurrent decreases in enstrophy due to viscous transport and dilatation. Taken together, these results provide further understanding of enstrophy dynamics in highly turbulent premixed flames.

Anisotropic neutron response of trans-stilbene and impact on a handheld dual particle imager

This manuscript details measurements of the anisotropic light-output response of trans-stilbene, henceforth referred to as stilbene, along the three primary crystal planes and analyzes how this anisotropic response impacts neutron image reconstruction in a handheld dual particle imager (H2DPI). A prototype H2DPI composed of stilbene pillars (6×6×50 mm3) coupled to silicon photomultipliers was built and is capable of imaging both fast neutrons and gamma rays from kilogram quantities of special nuclear material. Stilbene was chosen as the scintillating medium for the imager because of its pulse shape discrimination capability, time resolution and relatively high light output. A drawback to using stilbene, however, is the anisotropic response. A recoiling proton from a neutron elastic-scattering event in stilbene will yield different amounts of scintillation light depending on the direction of the recoiling proton with respect to the crystal lattice. This manuscript analyzes how this anisotropic response impacts neutron image reconstruction in 4π. The light output in the three primary crystal planes of stilbene were independently measured 6–7 times for proton recoil energies ranging from 0.5–5.0 MeV using a quasi-monoenergetic time-of-flight neutron source. The measured light-output data in the three crystal planes were fit with a semi-empirical function based on Birks’ formula. These fits were used to reconstruct the location of a 252Cf source in front of the imager (0°, −0.8°), to the left of the imager (−90°, −0.8°) and directly above the imager (0°, 90°) to determine if it is necessary to apply the directionally-dependent response of stilbene to accurately reconstruct source locations. A bootstrapping technique was applied to the measured data sets to produce 1000 images composed of 2000 cone projections for each source location and each measured light-output curve. List-mode maximum likelihood expectation maximization was applied to each image; the highest pixel location and the full width at half maximum (FWHM) were then recorded. The average and standard deviations of these parameters were taken for each set of images. The maximum difference in the average azimuthal pixel location when varying between the appropriate and incorrect light-output curves for the source locations at (0°, −0.8°) and (−90°, −0.8°) were respectively found to be 1.85±1.39° and 2.03±1.78°. All other pixel locations and FWHMs were within a single standard deviation of uncertainty. Taken together, the anisotropic response of stilbene has negligible impact on the neutron image reconstruction capability of the H2DPI.

Causal Associations of Anthropometric Measurements With Fracture Risk and Bone Mineral Density: A Mendelian Randomization Study.

Uncovering additional causal clinical traits and exposure variables is important when studying osteoporosis mechanisms and for the prevention of osteoporosis. Until recently, the causal relationship between anthropometric measurements and osteoporosis had not been fully revealed. In the present study, we utilized several state-of-the-art Mendelian randomization (MR) methods to investigate whether height, body mass index (BMI), waist-to-hip ratio (WHR), hip circumference (HC), and waist circumference (WC) are causally associated with two major characteristics of osteoporosis, bone mineral density (BMD) and fractures. Genomewide significant (p ≤ 5× 10-8 ) single-nucleotide polymorphisms (SNPs) associated with the five anthropometric variables were obtained from previous large-scale genomewide association studies (GWAS) and were utilized as instrumental variables. Summary-level data of estimated bone mineral density (eBMD) and fractures were obtained from a large-scale UK Biobank GWAS. Of the MR methods utilized, the inverse-variance weighted method was the primary method used for analysis, and the weighted-median, MR-Egger, mode-based estimate, and MR pleiotropy residual sum and outlier methods were utilized for sensitivity analyses. The results of the present study indicated that each increase in height equal to a single standard deviation (SD) was associated with a 9.9% increase in risk of fracture (odds ratio [OR]=1.099; 95% confidence interval [CI] 1.067-1.133; p=8.793× 10-10 ) and a 0.080 SD decrease of estimated bone mineral density (95% CI -0.106-(-0.054); p=2.322 × 10-9 ). We also found that BMI was causally associated with eBMD (beta=0.129, 95% CI 0.065-0.194; p=8.113× 10-5 ) but not associated with fracture. The WHR adjusted for BMI, HC adjusted for BMI, and WC adjusted for BMI were not found to be related to fracture occurrence or eBMD. In conclusion, the present study provided genetic evidence for certain causal relationships between anthropometric measurements and bone mineral density or fracture risk. © 2021 American Society for Bone and Mineral Research (ASBMR).

Abstract C070: Social determinants of health disparities in triple-negative breast cancer in Louisiana

Abstract Introduction: Triple-negative breast cancer (TNBC) is an aggressive, heterogeneous subtype of breast cancer. TNBC patients have generally high risk of recurrence and metastasis, and treatment options remain limited, as there are no effective targeted therapies available. In USA, TNBC is diagnosed disproportionately more frequently in African American (AA) women than in European American (EA) women. We set out to investigate the role of social determinants in racial disparities in TNBC. Methods: TNBC patients diagnosed in Louisiana from 2010-2012 were identified from the Louisiana Tumor Registry. Patients were geocoded to census tract of residence at time of diagnosis. Census tract population and socioeconomic measures were obtained from the US Census American Community Survey. We used multilevel statistical models to analyze the role of neighborhood concentrated disadvantage index (CDI), a robust measure of physical and social environment, in racial disparities in TNBC incidence, stage at diagnosis, and stage-specific survival for the study population. CDI scores were calculated according to the PhenX Toolkit protocol. Results: We identified 1,216 women with TNBC for the study. Controlling for age, we found that AA women had a 2.21-fold risk of TNBC incidence compared to EA in Louisiana. Results from multivariate analyses indicated that the incidence of TNBC was independent of neighborhood CDI, as was the racial disparity. However, CDI did explain existing racial disparities in both stage at diagnosis and stage-specific survival. The odds of diagnosis at later stages were 42% higher for black women. A single standard deviation increase in CDI increased the hazard of breast cancer-related death by 19%. Overall, our results suggest that the increased incidence of TNBC in black women is independent of CDI, while neighborhood environment has a greater impact than race on the promotion and progression of the disease. The socioeconomic disadvantage experienced by black women coupled with increased biologic risk for TNBC contribute to the large racial disparity in breast cancer mortality in Louisiana. Further research is needed to determine the mechanisms through which social determinants affect the promotion and progression of this disease and guide efforts to improve overall survival. Citation Format: Fokhrul Hossain, Denise Danos, Aubrey Gilliland, Claudia Leonardi, Tekeda Ferguson, Neal Simonsen, Qingzhao Yu, Om Prakesh, Richard Scribner, Lucio Miele. Social determinants of health disparities in triple-negative breast cancer in Louisiana [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C070.

TAAM: a reliable and user friendly tool for hydrogen-atom location using routine X-ray diffraction data.

Hydrogen is present in almost all of the molecules in living things. It is very reactive and forms bonds with most of the elements, terminating their valences and enhancing their chemistry. X-ray diffraction is the most common method for structure determination. It depends on scattering of X-rays from electron density, which means the single electron of hydrogen is difficult to detect. Generally, neutron diffraction data are used to determine the accurate position of hydrogen atoms. However, the requirement for good quality single crystals, costly maintenance and the limited number of neutron diffraction facilities means that these kind of results are rarely available. Here it is shown that the use of Transferable Aspherical Atom Model (TAAM) instead of Independent Atom Model (IAM) in routine structure refinement with X-ray data is another possible solution which largely improves the precision and accuracy of X-H bond lengths and makes them comparable to averaged neutron bond lengths. TAAM, built from a pseudoatom databank, was used to determine the X-H bond lengths on 75 data sets for organic molecule crystals. TAAM parametrizations available in the modified University of Buffalo Databank (UBDB) of pseudoatoms applied through the DiSCaMB software library were used. The averaged bond lengths determined by TAAM refinements with X-ray diffraction data of atomic resolution (dmin ≤ 0.83 Å) showed very good agreement with neutron data, mostly within one single sample standard deviation, much like Hirshfeld atom refinement (HAR). Atomic displacements for both hydrogen and non-hydrogen atoms obtained from the refinements systematically differed from IAM results. Overall TAAM gave better fits to experimental data of standard resolution compared to IAM. The research was accompanied with development of software aimed at providing user-friendly tools to use aspherical atom models in refinement of organic molecules at speeds comparable to routine refinements based on spherical atom model.

Mobility Analysis of AmpuTees (MAAT 6): Mobility, Satisfaction, and Quality of Life among Long-Term Dysvascular/Diabetic Prosthesis Users-Results of a Cross-Sectional Analysis.

ABSTRACTObjectiveThe aim of this study was to establish the mobility, satisfaction, and quality of life (QoL) among prosthesis users with dysvascular/diabetic amputation at both acute and long-term phases of prosthetic rehabilitation.MethodsThis is a multisite, cross-sectional outcomes analysis. A total of 341 individuals met the inclusion/exclusion criteria. Individuals were grouped into acute phases (0–3 months [n = 24], 4–6 months [n = 72]) and chronic phases (24–36 months [n = 91], 37–48 months [n = 53], 49–60 months [n = 47], and 60–84 months [n = 54]) after amputation. Mobility was measured with the Prosthetic Limb Users Survey of Mobility (PLUS-M), whereas QoL and satisfaction (Sat) were reported using 10-point scales adapted from the Prosthesis Evaluation Questionnaire–Well-Being (PEQ-WB). Composite PEQ-WB scores were also compared.ResultsThe average mobility, QoL, and Sat among prosthesis users was, respectively, 44.8 ± 10.6, 7.6 ± 2.2, and 7.6 ± 2.2. There were no observed differences in mobility (F5,330 = 1.52, P = 0.18), QoL (F5,333 = 0.78, P = 0.57), or PEQ-WB (F5,335 = 1.618, P = 0.155) between any groups. For Sat, there was a group difference (F5,334 = 2.44, P = 0.03) as individuals appear to experience an initial increase in Sat with receipt of a prosthesis (0–3 months) compared with 25 to 36 months (P = 0.005), 49 to 60 months (P = 0.008), and 61 to 84 months (P = 0.009).ConclusionsThose individuals with amputation secondary to dysvascular disease and diabetes who continue to participate in prosthetic rehabilitation appear to experience levels of mobility, Sat, and QoL 7 years after amputation comparable to that reported in the first 6 months postamputation. There may be a modest increase in Sat with receipt of an initial prosthesis, potentially due to an increased optimism for one's situation. Notably, the mobility levels observed in the dysvascular population through a range of long-term postamputation periods remain within a single standard deviation of the population mean for individuals with a lower-limb amputation using a prosthesis for mobility.