Leidos (United States)

ABSTRACT Objective This study longitudinally assessed how mobility across geographic regions and work–family conflict influenced spouse employment trajectories and perceptions of career hindrance. Background The unemployment rate for U.S. military spouses has remained 21% since 2015 with specific aspects of military life, such as moving, reported as negatively influencing their careers. Methods Survey data were used for multivariable regression models examining employment trajectories between baseline and follow‐up ( N = 3,149) and perceptions of career hindrance at follow‐up ( N = 2,766). Employment trajectories were categorized as follows: consistent, newly employed, and newly unemployed. Career hindrance was assessed continuously. Results Spouses who moved across geographic regions were more likely to be newly unemployed and less likely to be newly employed at follow‐up than to have consistent employment. Greater career hindrance was reported at follow‐up by spouses who moved across regions and experienced increased work–family conflict. Conclusion Findings suggest mobility was highly predictive of spouses becoming newly unemployed and reporting higher rates of career hindrance. Spouses' reports of increased military‐related work–family conflict also resulted in increased career hindrance. Implications Programs are available to assist military spouses with career development; however, employers should consider ways to help spouses maintain employment after military moves.

Noncompliance with mental health referrals among US military personnel remains a significant barrier to care. Operational deployments and military stressors contribute to mental health challenges, impacting treatment access and increasing costs for the Department of Defense. Identifying service members unlikely to follow through on referrals may enable targeted interventions. To develop machine learning (ML) models to predict noncompliance with mental health referrals and identify key predictors among active-duty personnel. This study utilized retrospective data to create predictive models for referral noncompliance. The study sample consisted of 14,289 active-duty personnel who received mental health referrals through the Periodic Health Assessment (PHA) from 2016 to 2020. Predictors included demographics, health screenings, medical history, and prior health care utilization. Outcome measures focused on noncompliance within 90 days of referral. Noncompliance with referrals occurred in 34.0% of the sample. Among predictive models, extreme gradient boosting (XGBoost) achieved the highest performance (AUC ≈ 0.80), with prior health care utilization (eg, previous clinic visits and mental health diagnoses) identified as the strongest predictor, followed by alcohol screening and age. ML models demonstrated strong potential for identifying at-risk individuals, supporting targeted interventions to improve mental health care follow-up. Future research will emphasize validation and explore mechanisms influencing noncompliance.

Abstract Since landing in 2012, the Radiation Assessment Detector (RAD) onboard the Mars science laboratory (MSL) Curiosity rover has encountered different local landscapes, which have induced variations in the local surface environment. The aim of this study is to include realistic and site‐specific local topography for any position in a radiation transport model, and to validate this modeling strategy by comparison with MSL/RAD results. We present a method that integrates complex planetary surface models into neutron transport simulations to assess how surface heterogeneities influence secondary neutron environments—combining flexible terrain representation with radiation transport modeling. By modeling the topography of the main sites traversed by the rover, we show and quantify the dependence of downward neutron intensity on topography, in particular on the blocking zenith angle, across the different energy ranges: thermal, epithermal, fast neutrons. Using a method involving the visible surface from an observation point, we reconstruct the additional albedo neutron environment created by the terrain as seen by MSL/RAD, using the Atmospheric RAdiation Model for Ionizing spectra on martian Surface (ARAMIS). In particular, we show that the terrain‐generated thermal neutron spectrum increases with greater topographic relief, while the flux of high‐energy neutrons (>1 MeV) decreases.

Instances of withdrawal, the practice of removing a penis from a vagina before ejaculation to prevent pregnancy, have increased in some US populations over the past two decades. There is a paucity of research, however, on the prevalence and correlates of withdrawal among adolescents and young adults (AYAs). This study sought to determine the prevalence and correlates of withdrawal use in a representative sample of AYAs in the US, highlighting the association between receipt of informal sexuality education and withdrawal use. We analyzed cross-sectional National Survey of Family Growth data from AYAs surveyed between 2011 and 2019 (15-24 years; N = 14,262). Prevalence of withdrawal was determined using different sexual activity time-points (at first sex and ever) and reference periods (past 3 and 12 months). Logistic regression models were used to identify correlates of withdrawal alone and combined with at least one other method. Across all waves and reference periods, the prevalence of withdrawal was higher among AYAs who combined it with at least one other method (ever [overall]=15.15, SE = 0.58) compared with those who used it as the only method (ever [overall]=8.32, SE = 0.38). Compared to the 2011-2013 wave, those in the 2015-2017 wave had greater odds of reporting using only withdrawal in the past 3 months (AOR: 1.50; 95% CI: 1.02, 2.21). The same trend was seen in those who used withdrawal with another method at last sex in the past 3 and 12 months. Withdrawal alone or combined with another method varied by receipt of informal sexuality education topics (e.g., methods of birth control vs STIs). Variations in use of withdrawal based on type of informal sexuality education received suggests that different motivations might inform interventions in promoting effective reproductive health practices.

Venezuelan equine encephalitis virus (VEEV) is an arbovirus that causes a disease in which 4%-14% of individuals can develop neurological symptoms. Prior to 1970, VEEV was developed as a biological threat agent due to its stability and high morbidity when administered by aerosol. Currently, no FDA-licensed vaccines nor therapeutics for VEEV exist. Single-domain antibodies (sdAbs) may provide a therapeutic option due to their small size and ability to bind recessed epitopes not recognized by conventional antibodies. This study identified two bivalent sdAbs that were able to protect mice from a lethal challenge against both epizootic and enzootic subtypes of VEEV. Cryo-EM structures of sdAb-VEEV complexes revealed the sdAbs that comprised the bivalent sdAbs to recognize a mixture of conserved and non-conserved regions of the VEEV envelope proteins. While all three of the cryo-EM-characterized epitopes were unique in terms of their recognized VEEV residues, two sdAbs, V2B3 and V2C3, overlapped sterically, explaining why only their combinations with the non-sterically overlapping sdAb V3A8f, which composed the bivalent sdAbs described here, were so particularly effective. Binding and neutralization studies found that the bivalent sdAbs have the potential to be broad-spectrum anti-alphavirus therapeutics as they cross-neutralize multiple alphaviruses.IMPORTANCEAlphaviruses are no longer geographically constrained to one region of the world but are expanding to be of global concern. In many regions of the world, multiple alphaviruses co-circulate; therefore, having a therapeutic that is pan-alphavirus is important. A cocktail of multiple pan-alphavirus binding/neutralizing antibodies (Abs) may provide optimal coverage against alphaviruses while decreasing the prevalence of viral escape mutants, which could cause the therapeutic to no longer be efficacious. Structures of these Abs, defining their recognition, could assist in identifying optimal combinations. A bivalent pan-alphavirus single-domain antibody could be used in a cocktail with already identified alphavirus IgG antibodies.

BackgroundWith increases in population aging and life expectancy, the burden of mild cognitive impairment (MCI), Alzheimer's disease, and related dementias (ADRDs) is projected to increase. Veterans, in particular, experience the same risk factors for MCI and ADRDs as the general U.S. population (e.g., aging, genetic risk) as well as service‐specific risk factors (e.g., traumatic brain injury, posttraumatic stress disorder [PTSD], occupational exposures) that may put them at greater risk.MethodThe current study aimed to examine the incidence and correlates of MCI and ADRDs in post‐9/11 veterans utilizing over 20 years of longitudinal data from the Millennium Cohort Study (n = 146,670). MCI and ADRD cases were ascertained through ICD‐9 and 10 codes obtained through Veterans Health Administration and Military Health System Data Repository electronic health records between 2001‐2024. Age‐ and sex‐adjusted rates were reported per 100,000 person‐years calculated from the date of birth and censored at the date of diagnosis, date of death, or end of the observation period (August 15th, 2024), whichever came first. Age‐ and sex‐adjusted rates by characteristic subgroups were estimated from direct standardization methods and standardized to the total military population in 2010.ResultDuring the study period, 1,759 veterans were diagnosed with MCI (25.82 cases per 100,000 person‐years, 95% CI=24.25, 27.38) and 661 veterans were diagnosed with ADRD (6.86 cases per 100,00 person‐years, 95% CI=6.17, 7.54). A majority of ADRDs did not have an identified etiology (e.g., unspecified dementias). Among those who did, Alzheimer's disease and vascular dementia were the most prevalent diagnoses within the cohort. Military characteristics, such as serving in the Army and in occupations with high risk for low‐level blast, were associated with higher age‐ and sex‐adjusted rates of MCI and ADRD diagnoses. Mental (e.g., PTSD, depression) and physical health (e.g., hearing loss, smoking) factors were also associated with higher rates of MCI and ADRDs.ConclusionFindings highlight potential unique military risk factors for the development of cognitive impairment and dementia. These findings may help to inform future policy and develop interventions aimed at reducing long‐term cognitive health consequences that may be associated with military service.

A historian confronts the transformative nature of metamorphosis.

A woven polyester fabric conformally coated with microcrystals of bismuth-based conductive coordination polymer absorbs H2S plume. As reported by Katherine A. Mirica et al. in their Research Article (e202509883), the resulting smart membrane acts as a variable resistor within an electronic circuit, giving a concentration-dependent signal as the fabric captures the gas. A molecular visualization shows polysulfide chains wrapping Bi nodes that promote multifunctional performance of detection, capture, and detoxification in one electronic textile.