Cross Section Measurements Research Articles

Experimental Validation of the Remote Sensing Method for River Velocity Measurement Using an Open-Source PIV Scheme—Case Study: Antisana River in the Ecuadorian Andes

This study presents the experimental validation of a remote sensing method for river flow velocity measurement, from which discharge is calculated, using Particle Image Velocimetry (PIV) combined with Unmanned Aerial Vehicles (UAVs). The case study focuses on the Antisana River in the Ecuadorian Andes, a region with challenging geography where accurate flow measurement is crucial for hydroelectric projects. The validation results demonstrate that the velocity measurements obtained through PIV closely align with those from standardized traditional methods. Furthermore, integrating technologies such as LiDAR for cross-sectional measurements, along with UAVs, would enable the accurate estimation of discharge in difficult-to-access areas. This approach has the potential to significantly enhance hydrological studies and water resource management in remote regions, especially for hydroelectric projects in the Ecuadorian Andes.

Added value in low-risk pregnancies of longitudinal changes in uterine Doppler and circulating angiogenic factors during the third trimester in predicting term preeclampsia.

To assess the relationship between longitudinal changes in the uterine Doppler velocimetry and the maternal profile of angiogenic factors in the third trimester of pregnancy and to assess their ability to predict term preeclampsia. A cohort of low-risk pregnant women was constructed at second trimester routine scan and scheduled for a uterine Doppler evaluation and measurement of the circulating levels of angiogenic factors at ~30 and ~36 weeks. The performance of both parameters at both time-points and their change over time from the first to the second measurement in predicting term preeclampsia was evaluated by logistic regression and receiver operating characteristic curve (ROC) analyses. A total of 1172 women were analyzed, of which 28 (2.4%) women developed term preeclampsia. At ~30 weeks, a model including the ratio sFlt-1/PlGF (fms-like tyrosine kinase-1/placental growth factor) and the uterine Doppler explained 16.2% of the uncertainty of developing term preeclampsia, while at ~36 weeks the same variables explained 25.2% [p<0.001]. A model including the longitudinal changes of both predictors had an R2 of 26.8%, which was not significantly different from that of the ~36 weeks evaluation [p=0.45]. The area under the curve (AUC) of the ~36 weeks sFlt-1/PlGF ratio was significantly higher than at ~30 weeks (0.86 [0.77-0.94] vs. 0.81 [0.73-0.9]; p=0.043). The AUC of the 30-to-36 week change of the sFlt-1/PlGF ratio (0.85 [0.77-0.94]) did not significantly differ from that of at ~36 weeks (p=0.82). At ~36 weeks, for a 10% of false positives, the sFlt-1/PlGF ratio had a detection rate of 71.4%, with positive and negative likelihood ratios of 7.3 and 0.32, respectively. A cross-sectional measurement of the sFlt-1/PlGF ratio outperforms uterine Doppler in predicting term preeclampsia. The combination of both markers does not improve such prediction, nor the evaluation of the longitudinal changes between ~30 and ~36 weeks.

Production of neutron-rich nuclei in the vicinity of 78Ni: Fragmentation reactions of unstable 81Ga and 82Ge beams

The fragmentation reactions of neutron-rich unstable nuclei 81Ga and 82Ge at 250 MeV/nucleon have been studied in order to search the optimal mean for the production of very neutron-rich nuclei in the vicinity of 78Ni. The newly measured cross sections were compared with various calculations, showing a good agreement with EPAX3.01. The present work provides experimental insights into the two-step scheme—fragmentation following fission—as a method to produce very neutron-rich nuclei through a combination of ISOL and fragmentation of post-accelerated beams of unstable nuclei. Our results enable an evaluation of the potential of the two-step scheme in the production of very neutron-rich nuclei for the 78Ni region. The two-step scheme using fragmentation of a post-accelerated 81Ga beam could be an option to produce neutron-rich nuclei around 78Ni when the 81Ga beam intensity reaches 1.0×108 pps, compared to the one-step scheme with fission of 238U.

Modeling the Process of Critical Exhaustion of Oxygen in a River Caused by Exponential Source of Pollution

The analysis and improvement of the river's change dynamics are critical to the global investigation of water quality issues. This study investigates the mathematical model representation of one dimension of a pair of advection-dispersion equations. These equations pertain to the concentrations of both pollutants and dissolved oxygen. Certain terms, which demonstrate an increase in the decay rate of pollution through exponential sources and assume a decreasing river's cross-sectional measurement, lead to the diminished oxygen levels observed in this study. The crucial points are demonstrated using both analytical and numerical analysis of the steady-state model, which allows for examining multiple situations about the elimination of oxygen and aquatic survival in a river with severe pollution.

First 70Zn(p,x) nuclear cross section measurements for theranostic 67Cu radionuclide production extended up to 100 MeV

In this work the nuclear reaction routes 70Zn(p,x)64,67Cu, 66,67Ga, and 65,69mZn, induced by a high-energy proton beam up to 100 MeV have been investigated. Demand for 67Cu is increasing worldwide because it is known to be one of the best radionuclides having theranostic properties. Thus, efforts to improve its global production are underway. In previous studies, experimental data about nuclear cross-section measurements on 70Zn-enriched targets induced by proton beams were limited to an energy range of up to 70 MeV. Our goal was to extend nuclear data on 70Zn over a wider and unexplored so far region from 42 MeV to 98 MeV. As a result, our data turned out to be in good agreement with the literature ones in the overlapping energy range. In addition, to the best of our knowledge, new nuclear data exceeding 70 MeV were provided, demonstrating an excellent analytical method for producing 67Cu in the extended energy range.

Measurements of jet cross-section ratios in 13 TeV proton-proton collisions with ATLAS

Measurements of jet cross-section ratios between inclusive bins of jet multiplicity are performed in 140 fb−1 of proton-proton collisions with s=13 TeV center-of-mass energy, recorded with the ATLAS detector at CERN’s Large Hadron Collider. These ratios are constructed from double-differential cross-section measurements that are made in bins of jet multiplicity and other observables that are sensitive the energy scale and angular distribution of radiation due to the strong interaction in the final state. Additionally, the scalar sum of the two leading jets’ transverse momenta is measured triple differentially, in bins of the third jet’s transverse momentum and of jet multiplicity. These measurements are unfolded to account for acceptance and detector-related effects. The measured distributions are used to construct ratios of the inclusive jet-multiplicity bins, which have been shown to be sensitive to the strong coupling αS while being less sensitive than other observables to systematic uncertainties and parton distribution functions. The measured distributions are compared with state-of-the-art QCD calculations, including next-to-next-to-leading-order predictions for two- and three-jet events. These predictions are generally found to model the data well and perform best in bins with a modest requirement on the third jet’s transverse momentum. Significant differences between data and Monte Carlo predictions are observed in events with large rapidity gaps and invariant masses of the leading jet pair. Studies leading to reduced jet energy scale uncertainties significantly improve the precision of this work and are documented herein. © 2024 CERN, for the ATLAS Collaboration 2024 CERN

A comprehensive head-to-head comparison of key plasma phosphorylated tau 217 biomarker tests.

Plasma phosphorylated-tau 217 (p-tau217) is currently the most promising biomarker for reliable detection of Alzheimer's disease (AD) pathology. Various p-tau217 assays have been developed, but their relative performance is unclear. We compared key plasma p-tau217 tests using cross-sectional and longitudinal measures of amyloid-β (Aβ)-PET, tau-PET, and cognition as outcomes, and benchmarked them against cerebrospinal fluid (CSF) biomarker tests. Samples from 998 individuals (mean[range] age 68.5[20.0-92.5], 53% female) from the Swedish BioFINDER-2 cohort, including both cognitively unimpaired and cognitively impaired individuals, were analyzed. Plasma p-tau217 was measured with mass spectrometry (MS) assays (the ratio between phosphorylated and non-phosphorylated [%p-tau217WashU] and p-tau217WashU) as well as with immunoassays (p-tau217Lilly, p-tau217Janssen, p-tau217ALZpath). CSF biomarkers included p-tau217Lilly, the FDA-approved p-tau181/Aβ42Elecsys, and p-tau181Elecsys. All plasma p-tau217 tests exhibited a high ability to detect abnormal Aβ-PET (AUC range: 0.91-0.96) and tau-PET (AUC range: 0.94-0.97). Plasma %p-tau217WashU had the highest performance, with significantly higher AUCs than all the immunoassays (Pdiff<0.007). For detecting Aβ-PET status, %p-tau217WashU had an accuracy of 0.93 (immunoassays: 0.83-0.88), sensitivity of 91% (immunoassays: 84-87%), and a specificity of 94% (immunoassays: 85-89%). Among immunoassays, p-tau217Lilly and plasma p-tau217ALZpath had higher AUCs than plasma p-tau217Janssen for Aβ-PET status (Pdiff<0.006), and p-tau217Lilly outperformed plasma p-tau217ALZpath for tau-PET status (Pdiff=0.025). Plasma %p-tau217WashU exhibited stronger associations with all PET load outcomes compared to immunoassays; baseline Aβ-PET load (R2: 0.72; immunoassays: 0.47-0.58; Pdiff<0.001), baseline tau-PET load (R2: 0.51; immunoassays: 0.38-0.45; Pdiff<0.001), longitudinal Aβ-PET load (R2: 0.53; immunoassays: 0.31-0.38; Pdiff<0.001) and longitudinal tau-PET load (R2: 0.50; immunoassays: 0.35-0.43; Pdiff<0.014). Among immunoassays, plasma p-tau217Lilly was more associated with Aβ-PET load than plasma p-tau217Janssen (Pdiff<0.020) and with tau-PET load than both plasma p-tau217Janssen and plasma p-tau217ALZpath (all Pdiff<0.010). Plasma %p-tau217 also correlated more strongly with baseline cognition (Mini-Mental State Examination[MMSE]) than all immunoassays (R2 %p-tau217WashU: 0.33; immunoassays: 0.27-0.30; Pdiff<0.024). The main results were replicated in an external cohort from Washington University in St Louis (n =219). Finally, p-tau217NULISA showed similar performance to other immunoassays in subsets of both cohorts. In summary, both MS- and immunoassay-based p-tau217 tests generally perform well in identifying Aβ-PET, tau-PET, and cognitive abnormalities, but %p-tau217WashU performed significantly better than all the examined immunoassays. Plasma %p-tau217 may be considered as a stand-alone confirmatory test for AD pathology, while some immunoassays might be better suited as triage tests where positive results are confirmed with a second test, which needs to be determined by future reviews incorporating results from multiple cohorts.

Measurement of γ-Rays Generated by Neutron Interaction with 16O at 30 MeV and 250 MeV

Abstract Deep understanding of $\gamma$-ray production from the fast neutron reaction in water is crucial for various physics studies at large-scale water Cherenkov detectors. We performed test experiments using quasi-mono energetic neutron beams ($E_n = 30$ and 250 MeV) at Osaka University’s Research Center for Nuclear Physics to measure $\gamma$-rays originating from the neutron–oxygen reaction with a high-purity germanium detector. Multiple $\gamma$-ray peaks which are expected to be from excited nuclei after the neutron–oxygen reaction were successfully observed. We measured the neutron beam flux using an organic liquid scintillator for the cross section measurement. With a spectral fitting analysis based on the tailored $\gamma$-ray signal and background templates, we measured cross sections for each observed $\gamma$-ray component. The results will be useful to validate neutron models employed in ongoing and future water Cherenkov experiments.

Cross-section measurements of neutron-induced reactions on Ge isotopes in the neutron energy range 14.0–18.9 MeV

Cross-section measurements of neutron-induced reactions on Ge isotopes in the neutron energy range 14.0–18.9 MeV

Longitudinal Changes in Peak Expiratory Flow Predict Risk for Incident Dementia.

Impaired respiratory function, measured via peak expiratory flow (PEF), has been associated with increased dementia risk. However, much of the current literature uses cross-sectional measures of PEF, whereas longitudinal relationships between changes in respiratory function and dementia risk are underexplored. Using 10 years of data (2011-2021) from 2,439 adults ages 65 and older in the National Health and Aging Trends Study (NHATS), we examined whether 5-year changes in PEF (2011-2016) were associated with risk for incident dementia over the subsequent 5-year period (2017-2021). PEF slopes for each participant were estimated using linear mixed-effects models and then grouped into quartiles: rapid, moderate, mild, and no declines. Discrete-time Cox proportional hazards models were used to estimate the risk for incident dementia by PEF slope category, while controlling for several health and sociodemographic characteristics. After excluding dementia cases during the exposure window (2011-2016), we identified 338 cases of incident dementia (13.9%) between 2017-2021. Rapid PEF declines between 2011-2016 were associated with 85% higher risk for incident dementia between 2017-2021 compared to those with no declines in PEF (HR=1.85; 95% CI [1.24, 2.76]). Results were robust to several sensitivity analyses. These findings demonstrate that declines in PEF may precede declines in cognition, suggesting that respiratory function may be an important dementia risk factor in older adults. Additionally, these findings highlight the utility of measuring PEF via a peak flow meter, which is a simple and inexpensive measure of respiratory function.

Measurement of single top-quark production in association with a W boson in pp collisions at s=13 TeV with the ATLAS detector

The inclusive cross section for the production of a single top quark in association with a W boson is measured using 140 fb−1 of proton-proton collision data collected with the ATLAS detector at s=13 TeV. Events containing two charged leptons and at least one jet identified as originating from a b-quark are selected. A multivariate discriminant is constructed to separate the tW signal from the tt¯ background. The cross section is extracted using a profile likelihood fit to the signal and control regions and it is measured to be σtW=75−14+15 pb, in good agreement with the Standard Model prediction. The measured cross section is used to extract a value for the left-handed form factor at the Wtb vertex times the Cabibbo-Kobayashi-Maskawa matrix element |fLVVtb| of 0.97±0.10. © 2024 CERN, for the ATLAS Collaboration 2024 CERN

Measurement of cross section of proton-induced reactions on oxygen with silicon dioxide target

Oxygen is one of the most common elements in the human body. Proton beams used in therapy induce nuclear reactions that cause a loss of fluence along the beam path. These reactions often lead to production of β+\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\beta ^+$$\\end{document} emitters with relatively short half-lives (less than 20 min). Cross sections for reactions on oxygen are not sufficiently known, particularly at proton energies above few tens of MeV. This contribution presents the results of an experiment, where silicon dioxide targets were used to study nuclear reactions induced by protons with energy below 60 MeV on oxygen. The proton beam was delivered by the AIC-144 cyclotron of the Institute of Nuclear Physics in Kraków. Cross sections of reactions leading to production of 11\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ ^{11}$$\\end{document}C, 13\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ ^{13}$$\\end{document}N and 15\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ ^{15}$$\\end{document}O were obtained. They agree well with the measurements using Cherenkov radiation in bulk SiO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_2$$\\end{document}. The recent measurements performed with a PET scanner provided similar results, except in the case of 16\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ ^{16}$$\\end{document}O(p,x)11\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ ^{11}$$\\end{document}C reaction studied in the energy of up to 200 MeV, where our results are 30% lower.

Effects of school closure on lifestyle behaviours and health outcomes in children during the COVID-19 pandemic in Chile: A time-matched analysis.

The COVID-19 pandemic led to school closures, potentially impairing children's behaviours and health. We aimed to explore the effects of school closure on lifestyle behaviours (dietary habits, physical activity) and health outcomes (adiposity, fitness, self-esteem, self-concept) in children. We measured 247 children before school closure (October-November 2019) and after school reopening (October-November 2021) (COVID-19 group). To distinguish the changes due to school closure from changes due to growth, we included 655 age-matched children with cross-sectional measurements in October-November 2019 (control group). The response of this group (i.e., differences between children with 2 years of difference) was considered the expected response to growth. Two-way ANOVA was used to test age-by-group interactions, indicating an effect of school closure. In 7-to-9-year-old children, the COVID-19 group had larger-than-expected decreases in physical activity (by 0.4 points), resulting in higher physical inactivity prevalence (by 19 percent points) at 9 years. This was accompanied by larger-than-expected increases in fat percentage (by 6.1 percent point). In 8-to-10-year-old children, the COVID-19 group had higher physical inactivity prevalence at 10 years (by 20 percent points). This was accompanied by larger-than-expected increases in fat percentage (by 8.3 percent points), z-score BMI (by 0.90 units), and waist circumference (by 6.1 cm). In 9-to-11-year-old children, the COVID-19 group had larger-than-expected decreases in physical activity (by 0.3 points) and increases in self-concept (by 0.2 points). The response in dietary habits, fitness, or self-esteem was not different between groups. Overall, school closure negatively impacted physical activity and adiposity, particularly in the youngest children.

Respiratory Symptoms and Paper Dust Exposure among Workers in the Paper Industry in Ethiopia: A Comparative Cross-Sectional Study

Chronic respiratory symptoms are a health concern in the paper industry. This study evaluates the association between personal inhalable paper dust exposure and chronic respiratory symptoms among workers in this industry. In total, 270 workers from the paper industry and 267 from a water bottling factory participated. Chronic respiratory symptoms were assessed using a standardized questionnaire, modified from the American Thoracic Society. A job exposure matrix, based on cross-sectional personal measurements of inhalable paper dust, was used to estimate the exposure–response relationship between cumulative dust exposure and chronic respiratory symptoms. There was a higher prevalence of chronic coughs (27.4% vs. 7.5%), breathlessness (25.6% vs. 11%), coughs with sputum (21.1% vs. 1.1%), and wheezing (25.6% vs. 5%) among paper workers compared to those in the water bottling industry. A Poisson regression analysis revealed that the prevalence ratios for chronic coughs (APR = 3.3 and 95% CI: 2.0–5.4), breathlessness (APR = 2.2 and 95% CI: 1.4–3.4), and wheezing (APR = 4.3 and 95% CI: 2.3–7.7) were significantly higher in paper workers than in water bottling workers. Among paper workers, a significant exposure–response relationship was observed between cumulative dust exposure and chronic coughs after adjusting for age, sex, history of respiratory illnesses, work in other dusty industries, and use of biofuels. As there were only four ever-smokers, smoking was not included in the regression analysis. The results show a significant association between dust exposure and coughing, highlighting the need for control measures to prevent the development of respiratory symptoms among workers.

Measurement of the e+e−→KSKL cross section near the ϕ(1020) resonance with the SND detector

The cross section for the e+e−→KSKL process is measured in the center-of-mass energy range from 1000 to 1100 MeV in the experiment with the SND detector at the VEPP-2000 e+e− collider. The measurement is carried out in the KS→2π0 decay mode. Data with an integrated luminosity of 20 pb−1 recorded in 2018 at 18 energy points are used in the analysis. The systematic uncertainty in the measured cross section at the maximum of the ϕ resonance is 0.9%. The mass, width of the ϕ meson, and the product of the branching fractions B(ϕ→KSKL)B(ϕ→e+e−) are determined from the fit to the cross section energy dependence. Published by the American Physical Society 2024

New BABAR studies for the data-driven predictions of the muon g − 2

Using the full BABAR data sample, a dedicated measurement of additional radiation in e+e−→μ+μ−γ and e+e−→π+π−γ initial-state-radiation events is presented. Results are obtained at next-to-leading and next-to-next-to-leading order, with one and two additional photons, respectively, for radiation from the initial and final states. The comparison with predictions from Phokhara and AfkQed Monte Carlo generators reveals discrepancies for the former in the one-photon rates and angular distributions. While this disagreement has a negligible effect on the e+e−→π+π−(γ) cross section measured by BABAR, the impact on other cross-section measurements may be larger than uncertainties assigned. The findings shed a new light on the long-standing deviation between the muon g−2 measurement and the Standard Model prediction using the data-driven dispersive approach.

Experimental measurements and theoretical calculations of excitation functions of 103Rh(α,xn)106m,105g,104gAg and 103Rh(α,αxn)101m,102gRh reactions up to 40 MeV

Activation cross sections of 103Rh(α,xn)106m,105g,104gAg and 103Rh(α,αxn)101m,102gRh radionuclides were measured at energies ranging from their respective threshold energies up to 40 MeV. Standard stacked foil activation technique was employed for irradiation. Residual activity was assayed using high-resolution gamma-ray spectrometry. Excitation functions were also theoretically calculated using TALYS nuclear reaction model to reproduce the experimental cross section data. The present data are compared with the available literature data, TENDL-2023 data using default values as well as the theoretical data calculated by TALYS-1.96. The shape and amplitude of the experimentally obtained excitation functions were well reproduced theoretically for all the studied radionuclides except for 105gAg, for which magnitude of the cross sections was not reproduced. The integral yields were also deduced using the measured cross sections and the stopping power of natural Rh from 40 MeV down to their threshold energies for these radionuclides, and compared with the experimental yield data available in the literature.

Persistently Low IgG2 Levels in a Subset of Patients Following Hematopoietic Cell Transplantation.

Infectious diseases remain a major cause of morbidity and mortality after hematopoietic cell transplantation (HCT). Secondary hypogammaglobulinemia is a risk factor for infectious diseases. Total immunoglobulin G (IgG) levels and the history of infectious diseases are an integral part of determining the indication for immunoglobulin replacement therapy. The clinical significance of IgG2 levels is not well established. Guidelines recommend using pathogen-specific IgG to evaluate patients with potential secondary immunodeficiency. However, it is difficult in practice to perform such testing. IgG2 may correlate well with pathogen-specific IgG but the clinical significance of IgG2 is not well established. To assess the prevalence of low IgG2 levels with normal IgG after HCT, we cross-sectionally measured the levels of several immunoglobulins, including IgG, IgA, IgM, and IgG2, after HCT, and we assessed the correlation between them. Among 121 patients who underwent cross-sectional measurements of IgG, IgA, IgM, and IgG2 levels after HCT, 114 had normal IgG2 levels (normal IgG2 group, ≥ 100mg/dL) and 7 had low IgG2 levels (low IgG2 group, < 100mg/dL). These 7 patients were allogeneic HCT recipients. All 7 patients with low IgG2 had cGVHD and 4/7 patients had normal total IgG levels. IgG2 levels may be low even in patients with normal IgG levels years after allogeneic HCT. Therefore, our study suggests that when patients develop infectious diseases, especially multiple episodes, it is recommended to measure IgG2 levels to exclude the possibility of secondary hypogammaglobulinemia after allogeneic HCT.

The AMS-02 Cosmic-Ray Deuteron Flux is Consistent with a Secondary Origin

The recent measurements of cosmic-ray (CR) deuteron fluxes by AMS-02 show that the rigidity dependence of deuterons is similar with that of protons but flatter than 3He, which has been attributed to the existence of primary deuterons with abundance much higher than that from the Big Bang nucleosynthesis. The requirement of highly deuteron-abundant sources imposes a serious challenge to modern astrophysics since there is no known process to produce a large amount of deuterons without violating other constraints. In this work we demonstrate that the fragmentation of heavy nuclei up to nickel plays a crucial role in shaping/enhancing the spectrum/flux of the CR deuterons. Based on the latest CR data, the predicted secondary fluxes of deuterons and 3He are found to be reasonably consistent with the AMS-02 measurements, and a primary deuteron component is not needed. The observed differences between the spectra of D and 3He, as well as those between the D/4He (D/p) and 3He/4He (3He/p) flux ratios, measured in the rigidity space, is probably due to the kinetic-energy-to-rigidity conversion and the solar modulation, given different charge-to-mass ratios of D and 3He. More precise measurements of the fragmentation cross sections of various nuclei to produce deuterons, tritons, and 3He in a wide energy range will be very helpful in further testing the secondary origin of cosmic-ray deuterons.

Improving Osteoporosis Prediction Using Vertebral Bone Quality Score and Paravertebral Muscle Measurements From Lumbar MRI Scans.

Retrospective cohort. This study aims to use a novel method of combining vertebral bone quality score with paravertebral cross-sectional area measurements to improve the accuracy of predicting individuals with total hip T-scores <-2.5. Osteoporosis is a prevalent skeletal condition associated with decreased bone density and increased fracture risk. Dual-energy x-ray absorptiometry (DXA) is the conventional method for diagnosing osteoporosis, but it has limitations. Opportunistic osteoporosis screening techniques using lumbar magnetic resonance imaging (MRI), particularly the vertebral bone quality (VBQ) score, have shown promise. This study aims to improve the accuracy of predicting individuals with low total hip T-scores using a novel method that combines VBQ scores with paravertebral cross-sectional area (CSA) measurements. A retrospective cohort of 98 patients with DXA and lumbar MRI scans was analyzed. VBQ scores were calculated based on lumbar MRI images, and CSA measurements of paravertebral and psoas muscles were obtained. Threshold-based logistic regression was used to identify optimal thresholds for predicting total hip T-scores <-2.5. The combined model incorporating the VBQ score and paravertebral muscle percent achieved an accuracy of 96.9% for predicting total hip T-scores <-2.5, compared to 81.6% when using the VBQ score alone. Incorporating paravertebral muscle measurements significantly improved the accuracy of identifying osteoporotic individuals. The combination of VBQ score and paravertebral muscle measurements enhances the accuracy of predicting individuals with low total hip T-scores. Lumbar MRI scans provide valuable information beyond opportunistic osteoporosis screening, and the inclusion of paravertebral muscle measurements could aid in identifying at-risk individuals more accurately.