bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on the friction pair of the space high-power and long-life rolling ring
Authors: Liu Chengshan , Chen Xiuqun , Qian Zhiyuan
Published: October 2019

With the development of spacecraft, the requirement for high-power, long-life and high-reliability electrical transmission technology of the rolling ring is increasingly urgent. Aiming at the friction pair’s structure of the rolling ring, relevant theoretical and experimental research was carried out. The kinematic model is established to determine the friction pair’s structure of the rolling ring, and the zero sliding of friction pair is verified by ADAMS simulation. The electrical contact resistance and fatigue life of the friction pair are theoretically analyzed, and the cycling life of the flexure was analyzed. The stress distribution of flexure during rolling was simulated by FEM. The lifetime experiment of 1.5 × 105 r that the prototype transmitted the 6.6 kW of single loop was verified. The experimental result shows that the electrical contact resistance and the fluctuation value of the single loop are less than 1m Ω during the rolling, although the transmission power increased to 10 times as compared with the traditional slip ring. The kinematic model can provide a certain theoretical reference for design of the space high-power and long-life rolling ring.
Research on automatic assembly technology for final assembly of helicopter fuselage
Authors: Xiao Q D , Zhang L A , Gan L , Cheng T
Published: October 2019

The helicopter fuselage has the characteristics of compact structure space, complex coordination relationship and weak rigidity, etc. It is difficult to control the accuracy of the desired shape. According to the high precision and quality requirement of final assembly for helicopter fuselage, the application status of automatic assembly technology in aviation manufacturing was analyzed. Then the difficulties of automatic assembly technology for fuselage final assembly were also discussed. In this paper, an automatic assembly system for the final assembly of helicopter fuselage was designed, and relevant key technologies of the assembly system mentioned above were proposed. The designed system have the functions of automatic positioning, clamping, measuring, drilling, feeding and blind fastener riveting for fuselage components, which can improve the assembly quality and efficiency of helicopter fuselage during the final assembly process.
Study on the compacting device of combination for ridge-till and no-till planters
Authors: Luo Hongqi , Liu Xia , Qin Jiatong , Zhao Guangwei
Published: October 2019

Ridge tillage and conservation tillage combination is an important technology. The compacting device is one of the key components of no till planter. According to different agronomic requirements, a general type of combined type of pressing device was designed. In the device, the compacted wheel set should be designed, the ridge is compacted along the loose soil, and the ridging effect is enhanced. Meanwhile, the ring structure is designed on the compacting wheel to suppress the seeding belt. Through the force analysis and Simulation of the suppression device, the structural parameters are determined, and the adjustable mechanism is designed to realize the adjustability of the pressure of the town. By designing movable pressing ring, the number and size of the ring can be adjusted to meet the needs of different agronomic conditions. The modelling of combined press device is conducive to the promotion of no tillage seeding technique, which is a better combination of advantages of ridge tillage and conservation tillage.
Impact wear behavior of WC/a-C nanomultilayers
Authors: He Dongqing , Li Wensheng , Wang Liping , Lu Zhibin , Zhang Guangan , Cai Zhenbing
Published: October 2019

A novel design of WC/a-C multilayers with ultrathin modulation period ranging from 1.3 to 11.5 nm was fabricated by unbalanced magnetron sputtering process, and the influence of modulation period on the impact wear behavior of the films was investigated from impact dynamic response and typical wear analysis. Results show that the peak impact force, impact energy absorption rate and impact wear volume loss of the films decrease firstly and then increase with increasing the modulation period, and both reach the minimum value at Λ = 9.1 nm. High hardness, toughness and plastic deformation resistance originated from the ‘superlattice-like structure’ of the films at appropriate modulation period are proved to be responsible for the low peak impact force, low impact energy absorption rate and then the improved impact wear resistance. While, the films with low hardness and H3/E2 have severe plastic deformation and impact-induced graphitization during impact process which in turn further reduce the hardness and H3/E2 of the film itself, thus eventually resulting in severe impact wear.
Influence of a dynamic rearing environment on development of metabolic phenotypes in age-0 Lake Sturgeon, Acipenser fulvescens
Authors: Yoon Gwangseok R , Deslauriers David , Anderson W Gary
Published: October 2019

Environment–phenotype interactions are the most pronounced during early life stages and can strongly influence metabolism and ultimately ecological fitness. In the present study, we examined the effect of temperature [ambient river temperature (ART) vs ART+2°C], dissolved oxygen (DO; 100% vs 80%) and substrate (presence vs absence) on standard metabolic rate, forced maximum metabolic rate and metabolic scope with Fulton’s condition factor (K), energy density (ED) and critical thermal maximum (CTmax) in age-0 Lake Sturgeon, Acipenser fulvescens, before and after a simulated overwintering event. We found that all the environmental variables strongly influenced survival, K, ED and CTmax. Fish reared in elevated temperature showed higher mortality and reduced K pre-winter at 127 days post-hatch (dph). Interestingly, we did not find any significant difference in terms of metabolic rate between treatments at both sampling points of pre- and post-winter. Long-term exposure to 80% DO reduced ED in Lake Sturgeon post-winter at 272 dph. Our data suggest that substrate should be removed at the onset of exogenous feeding to enhance the survival rate of age-0 Lake Sturgeon in the first year of life. Effects of early rearing environment during larval development on survival over winter are discussed with respect to successful recruitment of stock enhanced Lake Sturgeon, a species that is at risk throughout its natural range.
Traffic noise exposure depresses plasma corticosterone and delays offspring growth in breeding zebra finches
Authors: Zollinger Sue Anne , Dorado-Correa Adriana , Goymann Wolfgang , Forstmeier Wolfgang , Knief Ulrich , Bastidas­Urrutia Ana María , Brumm Henrik
Published: October 2019

The impact of human activity on the acoustic environment is overwhelming, with anthropogenic noise reaching even remote areas of the planet. The World Health Organization has identified noise pollution as one of the leading environmental health risks in humans, and it has been linked to a myriad of short- and long-term health effects in exposed individuals. However, less is known about the health effects of anthropogenic noise exposure on animals. We investigated long- and short-term effects of traffic noise on zebra finches breeding in small communal aviaries, using a repeated measures design. Birds bred in both noise and no-noise conditions, and we measured baseline plasma glucocorticoid levels before, during and after breeding. In addition, we assayed immune function, measured reproductive success and offspring growth and compared rates of extra-pair paternity of breeding adults. Breeding birds had significantly lower baseline plasma corticosterone levels when exposed to traffic noise than when they were not exposed to noise playback. In addition, the nestlings reared during noise exposure were lighter than nestlings of the same parents when breeding in control conditions. Our results suggest that traffic noise poses a more severe hurdle to birds at more vulnerable stages of their life history, such as during reproductive events and ontogeny. While chronic exposure to traffic noise in our birds did not, by itself, prove to be a sufficient stressor to cause acute effects on health or reproductive success in exposed individuals, it did result in disruptions to normal glucocorticoid profiles and delayed offspring growth. However, animals living in urban habitats are exposed to a multitude of anthropogenic disturbances, and it is likely that even species that appear to be thriving in noisy environments may suffer cumulative effects of these multiple disturbances that may together impact their fitness in urban environments.
Usefulness of 18F-fluorodeoxyglucose positron emission tomography/computed tomography angiography in a patient with blood culture-negative prosthetic valve endocarditis complicated with perivalvular abscess: a case report
Authors: Miura Shiro , Naya Masanao , Yamashita Takehiro , Ohkawa Youhei
Published: October 2019

Background

Prosthetic valve endocarditis (PVE) is a life-threatening systemic infection involving a high mortality rate and severe complications, including perivalvular abscess. Early diagnosis and detection of PVE continue to be challenging in clinical settings.

Case summary

A 64-year-old man with a history of mechanical aortic valve implantation 12 years prior was referred to our hospital with a major complaint of high fever and was admitted. Although results of three blood culture tests at admission were negative, transthoracic echocardiography, and transoesophageal echocardiography (TOE) were performed to exclude the possibility of PVE; both, however, were inconclusive. Subsequently, 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) was performed; revealing intense hyper-metabolism above the aortic valve prosthesis with a greater intensity at the posterior end, confirming a diagnosis of aortic PVE complicated with perivalvular abscess.

Discussion

Considering the intermediate suspicion of PVE despite negative TOE and negative blood culture tests, 18F-FDG PET/CT can play a central role in diagnosing PVE. However, this new imaging modality often fails to differentiate thrombi, soft atherosclerotic plaques, or foreign body reactions on the surface of prosthetic valves. In this report, we have successfully enhanced the diagnostic accuracy of 18F-FDG PET/CT by focusing on perivalvular involvement, which could be a key finding, because intense 18F-FDG uptake surrounding the aortic annulus was consistent with the thickened area within the aortic annular region observed in the TOE examinations.
Focal mechanisms of the 2017 North Korean nuclear test and its early collapse event
Authors: Xu Henglei , Ni Sidao , Liu Wenxue , Zhu Haofeng , Wang Xuliang
Published: October 2019

North Korea conducted sixth underground nuclear test on 3 September 2017. Unlike its previous tests, a rare subsequent collapse event occurred after about 8.5 min. As two types of distinctive shallow seismic events, accurate inversion of their focal mechanisms is important for event identification for CTBT. In this paper, we carry out moment tensor inversion of the nuclear test and the collapse event with gCAP using waveform data from dense regional seismic stations. And their focal mechanisms are further constrained with surface wave amplitude ratio. The results show that the surface wave amplitude ratio has further constraints for screening the waveform inversion results. The resolution of the focal mechanism inversion for the nuclear test is high, which is close to a Crack source. However, the resolution for the collapse event inversion is not so high and the source type is difficult to be accurately determined. One reason of the poor resolution for the collapse event may be due to the limited availability of high quality data, and complexity of the source process might be another factor.
Engaging users in the design of an mHealth, text message-based intervention to increase physical activity at a safety-net health care system
Authors: Avila-Garcia Patricia , Hernandez-Ramos Rosa , Nouri Sarah S , Cemballi Anupama , Sarkar Urmimala , Lyles Courtney R , Aguilera Adrian
Published: October 2019

Objectives

Text-messaging interventions are a promising approach to increasing physical activity in vulnerable populations. To better inform the development of a text-messaging intervention, we sought to identify barriers and facilitators to using text messaging and engaging in physical activity among patients with diabetes and comorbid depression.

Materials and Methods

We conducted interviews with primary care patients at a safety-net health care system (N = 26). Data were collected at 3 stages, including a focus group (stage 1), and individual interviews (stage 2 and 3). Patients in stage 1 and 2 previously participated in a text-messaging intervention as part of depression treatment. Discussions focused on participant experience of previously using a text-messaging intervention, influences and perceptions of physical activity, and mobile phone use. We analyzed all transcripts for emerging themes.

Results

Participants were 56.2 years (±9.7); 69.2% were female, 65.4% identified as Hispanic/Latino(a), and 46.2% reported having less than a high school education. All had depression and 61.5% had diabetes. Specific barriers that emerged included low literacy and only basic use of mobile phones in everyday life, in combination with a high prevalence of comorbid health conditions and limited mobility. These were each addressed with a specific content or intervention delivery change in the overall intervention design.

Conclusions

Conducting a focus group and individual interviews with end users of an mHealth intervention under development has implications for tailoring and modifying components of the content and format to ensure that the final intervention will engage end users most effectively.
Improvement of Endoscopic Reports with Implementation of a Dictation Template
Authors: Harris Natasha , Telford Jennifer , Yonge Jordan , Galorport Cherry , Amar Jack , Bressler Brian , Brown Carl , Lam Eric , Nap-Hill Estello , Phang Terry , Ramji Alnoor , Suzuki Matthew , Whittaker J Scott , Enns Robert
Published: October 2019

Aims

Completeness of procedure reports is an important quality indicator in endoscopy. A dictation template was developed to ensure key elements were included in colonoscopy and esophagogastroduodenoscopy (EGD) reports. Endoscopy reports were reviewed prior to and following implementation of the dictation templates to determine whether report completeness improved.

Methods

Key elements in an endoscopic report were identified from published guidelines and posted at dictation stations. Colonoscopy and EGD reports were reviewed for the nine physicians performing endoscopy at St. Paul’s Hospital prior to and following implementation of dictation templates. Dictation completeness was defined as inclusion of all key elements. Dictation completeness and inclusion of individual key elements at the two time points were compared using the t-test and Chi-square test.

Results

Reports for 4648 procedures undertaken by nine endoscopists were reviewed for completeness at each time point (2008 and 2014). Colonoscopy report completeness increased from 65.8% to 83.2% (P < 0.001). Items that improved included documentation of consent, endoscope used, complications, withdrawal time and rectal retroflexion. EGD report completeness increased from 72.7% to 77.3% (P < 0.001) with improvement in documentation of consent and complications. Items consistently underreported for colonoscopy and EGD at both time points included: patient age, comorbidities, current medications and patient comfort.

Conclusion

There was an association between the use of a posted dictation template at dictation stations and the improved completeness of endoscopic reports.
Missing Unmarried Women
Authors: Anderson Siwan , Ray Debraj
Published: October 2019

That unmarried individuals die at a faster rate than married individuals at all ages is well documented. Unmarried women in developing countries face particularly severe vulnerabilities, so that excess mortality faced by the unmarried is more extreme for women in these regions compared to developed countries. We provide systematic estimates of the excess female mortality faced by older unmarried women in developing regions. We place these estimates in the context of the missing women phenomenon. There are approximately 1.5 million missing women between the ages of 30 and 60 years old each year. We find that 35% of these missing women of adult age can be attributed to not being married. These estimates vary by region. India has the largest proportion of missing adult women who are without a husband, followed by the countries in East Africa. By contrast, China has almost no missing unmarried women. We show that 70% of missing unmarried women are of reproductive age and that it is the relatively high mortality rates of these young unmarried women (compared to their married counterparts) that drive this phenomenon.
Simple Forecasting Heuristics that Make us Smart: Evidence from Different Market Experiments
Authors: Anufriev Mikhail , Hommes Cars , Makarewicz Tomasz
Published: October 2019

In this paper we address the question of how individuals form expectations and invent, reinforce, and update their forecasting rules in a complex world. We do so by fitting a novel, parsimonious, and empirically validated genetic algorithm learning model with explicit heterogeneity in expectations to a set of laboratory experiments. Agents use simple linear first order price forecasting rules, adapting them to the complex evolving market environment with a Genetic Algorithm optimization procedure. The novelties are: (1) a parsimonious experimental foundation of individual forecasting behavior; (2) explanation of individual and aggregate behavior in three different experimental settings, (3) improved one- and 50-period ahead forecasting of experiments, and (4) characterization of the mean, median, and empirical distribution of forecasting heuristics. The median of the distribution of GA forecasting heuristics can be used in designing or validating simple Heuristic Switching Models.
Measuring the impact of insurance on urban earthquake recovery using nightlights
Authors: Nguyen Cuong Nhu , Noy Ilan
Published: October 2019

We measure the longer-term effect of a major earthquake on the local economy, using night-time light intensity, and focus on the role of insurance payments for damaged residential property in the recovery process. The destructive Canterbury Earthquake Sequence (2010–2011) in New Zealand is our case study. Uniquely, for this event, >95% of residential housing units were covered by insurance and almost all incurred some damage. However, insurance payments were staggered over 5 years, enabling us to identify their local impact on recovery. We find that night-time luminosity can capture the process of recovery; and that insurance payments contributed significantly to the process of local economic recovery after the earthquake. Cash settlement of claims was no more effective than insurance-managed repairs in generating local recovery. Notably, delayed payments were less affective in assisting recovery; this suggests an important role for the regulator in making sure insurance payments are made promptly after disaster events.
Laboratory Rearing of Culicoides stellifer (Diptera: Ceratopogonidae), a Suspected Vector of Orbiviruses in the United States
Authors: Erram Dinesh , Burkett-Cadena Nathan
Published: October 2019

Laboratory rearing procedures of Culicoides stellifer Coquillett (Diptera: Ceratopogonidae) were evaluated with an aim towards colonization of this species. Eggs collected from field-collected gravid females were placed on 0.25% agar slants and given a diet of 1) nematodes (Panagrellus redivivus Linnaeus), 2) nematodes + lactalbumin and yeast (LY), 3) microbes from nematode medium, and 4) tap water (autoclaved). Complete larval development to adult stage occurred only in two treatments: 1) nematodes and 2) nematodes + LY. Culicoides stellifer larvae could not survive beyond 1 wk on a diet of microbes alone or in the sterile water treatment. Larval survival rates were high using nematode diet (79.2 ± 11.3% [mean ± SE]) but were slightly lower in the nematode + LY group (66.5 ± 19.6%). Larval stage lasted ~21 d in both treatments. Sex ratio of F1 adults was ~1:1 (M:F) using nematode diet but was male biased (~2:1) with nematode + LY diet. These findings collectively suggest that a microbial community is required for midge larvae, either to support invertebrate prey base or as a potential food source. But in the present study, the supplied microbes alone were not sufficient to support midge survival/development. It appears that other nutritional components may also be essential to support the larval survival/development of C. stellifer. Overall, a simple diet of bacterial feeding nematodes and their associated microorganisms can be used to rear C. stellifer larvae under laboratory conditions. However, captive mating in F1 adults poses a major obstacle for successful colonization of this species currently.
Efficacy of Long-lasting Insecticidal Nets With Declining Physical and Chemical Integrity on Aedes aegypti (Diptera: Culicidae)
Authors: Herrera-Bojórquez Josué , Trujillo-Peña Emilio , Vadillo-Sánchez José , Riestra-Morales Martin , Che-Mendoza Azael , Delfín-González Hugo , Pavía-Ruz Norma , Arredondo-Jimenez Juan , Santamaría Erika , Flores-Suárez Adriana E , Vazquez-Prokopec Gonzalo , Manrique-Saide Pablo
Published: October 2019

Fitting long-lasting insecticidal nets (LLIN) as screens on doors/windows has a significant impact on indoor-adult Aedes aegypti (L.), with entomological reductions measured in a previous study being significant for up to 2 yr post-installation, even in the presence of pyrethroid-resistant Aedes populations. To better understand the mode of LLIN protection, bioassays were performed to evaluate the effects of field deployment (0, 6, and 12 mo) and damage type (none, central, lateral, and multiple) on LLIN efficacy. Contact bioassays confirmed that LLIN residual activity (median knockdown time, in minutes, or MKDT) decreased significantly over time: 6.95 (95% confidence interval [CI]: 5.32–8.58) to 9.24 (95% CI: 8.69–9.79) MKDT at 0- and 12-mo age, respectively, using a pyrethroid-susceptible Aedes strain. Tunnel tests (exposing human forearm for 40 min as attractant) showed that deployment time affected negatively Aedes passage inhibition from 54.9% (95% CI: 43.5–66.2) at 0 mo to 35.7% (95% CI: 16.3–55.1) at 12 mo and blood-feeding inhibition from 65.2% (95% CI: 54.2–76.2) to 48.9% (95% CI: 26.4–71.3), respectively; both the passage/blood-feeding inhibition increased by a factor of 1.8–2.9 on LLINs with multiple and central damages compared with nets with lateral damage. Mosquito mortality was 74.6% (95% CI: 65.3–83.9) at 0 mo, 72.3% (95% CI: 64.1–80.5) at 6 mo, and 59% (95% CI: 46.7–71.3) at 12 mo. Despite the LLIN physical integrity could be compromised over time, we demonstrate that the remaining chemical effect after field conditions would still contribute to killing/repelling mosquitoes.
Cost-Effectiveness of Risk-Stratified Colorectal Cancer Screening Based on Polygenic Risk: Current Status and Future Potential
Authors: Naber Steffie K , Kundu Suman , Kuntz Karen M , Dotson W David , Williams Marc S , Zauber Ann G , Calonge Ned , Zallen Doris T , Ganiats Theodore G , Webber Elizabeth M , Goddard Katrina A B , Henrikson Nora B , van Ballegooijen Marjolein , Janssens A Cecile J W , Lansdorp-Vogelaar Iris
Published: October 2019

Background

Although uniform colonoscopy screening reduces colorectal cancer (CRC) mortality, risk-based screening may be more efficient. We investigated whether CRC screening based on polygenic risk is a cost-effective alternative to current uniform screening, and if not, under what conditions it would be.

Methods

The MISCAN-Colon model was used to simulate a hypothetical cohort of US 40-year-olds. Uniform screening was modeled as colonoscopy screening at ages 50, 60, and 70 years. For risk-stratified screening, individuals underwent polygenic testing with current and potential future discriminatory performance (area under the receiver-operating curve [AUC] of 0.60 and 0.65–0.80, respectively). Polygenic testing results were used to create risk groups, for which colonoscopy screening was optimized by varying the start age (40–60 years), end age (70–85 years), and interval (1–20 years).

Results

With current discriminatory performance, optimal screening ranged from once-only colonoscopy at age 60 years for the lowest-risk group to six colonoscopies at ages 40–80 years for the highest-risk group. While maintaining the same health benefits, risk-stratified screening increased costs by $59 per person. Risk-stratified screening could become cost-effective if the AUC value would increase beyond 0.65, the price per polygenic test would drop to less than $141, or risk-stratified screening would lead to a 5% increase in screening participation.

Conclusions

Currently, CRC screening based on polygenic risk is unlikely to be cost-effective compared with uniform screening. This is expected to change with a greater than 0.05 increase in AUC value, a greater than 30% reduction in polygenic testing costs, or a greater than 5% increase in adherence with screening.
Combining Information from Multiple Data Sources to Assess Population Health
Authors: Raghunathan Trivellore , Ghosh Kaushik , Rosen Allison , Imbriano Paul , Stewart Susan , Bondarenko Irina , Messer Kassandra , Berglund Patricia , Shaffer James , Cutler David
Published: October 2019

Information about an extensive set of health conditions on a well-defined sample of subjects is essential for assessing population health, gauging the impact of various policies, modeling costs, and studying health disparities. Unfortunately, there is no single data source that provides accurate information about health conditions. We combine information from several administrative and survey data sets to obtain model-based dummy variables for 107 health conditions (diseases, preventive measures, and screening for diseases) for elderly (age 65 and older) subjects in the Medicare Current Beneficiary Survey (MCBS) over the fourteen-year period, 1999–2012. The MCBS has prevalence of diseases assessed based on Medicare claims and provides detailed information on all health conditions but is prone to underestimation bias. The National Health and Nutrition Examination Survey (NHANES), on the other hand, collects self-reports and physical/laboratory measures only for a subset of the 107 health conditions. Neither source provides complete information, but we use them together to derive model-based corrected dummy variables in MCBS for the full range of existing health conditions using a missing data and measurement error model framework. We create multiply imputed dummy variables and use them to construct the prevalence rate and trend estimates. The broader goal, however, is to use these corrected or modeled dummy variables for a multitude of policy analysis, cost modeling, and analysis of other relationships either using them as predictors or as outcome variables.
Epidemiology and Financial Burden of Musculoskeletal Injuries as the Leading Health Problem in the Military
Authors: Dijksma Captain Iris , Bekkers Marga , Spek Bea , Lucas Cees , Stuiver Martijn
Published: October 2019

Introduction

Musculoskeletal injuries (MSIs) have direct impact on occupational readiness and task performance in military populations. Until this date, no epidemiologic data have been published concerning MSI incidence in the Netherlands Armed Forces (NAF). The aim of this study was to assess the MSI incidence and related costs in the NAF.

Methods

In this descriptive epidemiologic study, we collected injury surveillance data from the electronic patient records of multiple military units of the NAF. Using data of all new consultations with a military physician from January 1, 2014 to December 31, 2016, we calculated MSI incidence rates per 100 person-years, with a 95% confidence interval (CI). Physician care costs were determined based on the number of physician consults and the charge per appointment. We used two methods to determine productivity costs; the top-down microcosting method and the friction cost method.

Results

Our study sample included 22% (n = 8,847) of the total NAF population of 2016 (n =40,178). In this sample, consultations of MSIs accounted for 23.2% (n = 7,815) of all new consultations (n = 33,666). MSI incidence rates per unit ranged from 12.5 to53.3 per 100 person-years. In the total sample, MSI incidence rates were highest in the back (6.73, 95% CI 6.39–7.10), knee (5.04, 95% CI 4.74–5.35), and foot (4.79, 95% CI 4.50–5.10). The estimated costs for physician visits for MSIs in our sample were €0.69 million. Limited duty days accounted for €1.10 million productivity costs using top-down microcosting method.

Conclusion

Our study provided evidence that MSIs result in substantial financial burden. Injuries of the back, knee, and foot account for the majority of demands on curative care for MSIs.
Semi-Automated Neurofeedback Therapy for Persistent Postconcussive Symptoms in a Military Clinical Setting: A Feasibility Study
Authors: Hershaw Jamie N , Hill-Pearson Candace A , Arango Jorge I , Souvignier Alicia R , Pazdan Renee M
Published: October 2019

Introduction

Neurofeedback therapy (NFT) has demonstrated effectiveness for reducing persistent symptoms following traumatic brain injury (TBI); however, its reliance on NFT experts for administration and high number of treatment sessions limits its use in military medicine. Here, we assess the feasibility of live Z-score training (LZT)—a variant of NFT that requires fewer treatment sessions and can be administered by nonexperts—for use in a military clinical setting.

Materials and Methods

A single group design feasibility study was conducted to assess acceptability, tolerance, treatment satisfaction, and change in symptoms after a 6-week LZT intervention in 38 Service Members (SMs) with persistent symptoms comorbid with or secondary to mild TBI. Acceptance and feasibility were assessed using treatment completion and patients’ satisfaction with treatment. To evaluate changes in symptom status, a battery of self-report questionnaires was administered at baseline, posttreatment, and 3-month follow-up to evaluate changes in psychological, neurobehavioral, sleep, pain, and headache symptoms, as well as self-efficacy in symptom management and life satisfaction.

Results

Participants tolerated the treatment well and reported a positive experience. Symptom improvement was observed, including depressive, neurobehavioral, and pain-related symptoms, with effects sustained at 3-month follow-up.

Conclusion

LZT treatment appears to be a feasible, non-pharmacological therapy amenable to SMs. Results from this pilot study promote further investigation of LZT as an intervention for SMs with persistent symptoms following TBI.
The Influence of Self-Reported Tobacco Use on Baseline Concussion Assessments
Authors: Roach Sean P , Houston Megan N , Peck Karen Y , Svoboda Steven J , Kelly Tim F , Malvasi Steven R , McGinty Gerald T , Campbell Darren E , Cameron Kenneth L
Published: October 2019

Introduction

Baseline symptom, balance, and neurocognitive scores have become an integral piece of the concussion management process. Factors such as sleep, learning disorders, fitness level, and sex have been linked to differences in performance on baseline assessments; however, it is unclear how tobacco use may affect these scores. The objective of this study was to compare baseline concussion assessment scores between service academy cadets who use and do not use tobacco.

Methods

Cadets completed a standard battery of concussion baseline assessments per standard of care and were classified into two groups: tobacco users (n = 1,232) and nonusers (n = 5,922). Dependent variables included scores on the Balance Error Scoring System, Standardized Assessment of Concussion, Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT), Brief Symptom Inventory-18, and Brief Sensation Seeking Scale (BSSS). Separate Mann–Whitney U-tests were used to compare all baseline assessment scores between groups with an adjusted P-value < 0.004.

Results

Cadets that used tobacco performed significantly worse on the impulse control (P < 0.001) section of the ImPACT, reported greater ImPACT symptom severity scores (P < 0.001), and were more likely to take risks as measured by the BSSS (P < 0.001). No differences were detected for Balance Error Scoring System, Standardized Assessment of Concussion, Brief Symptom Inventory-18, and Sport Concussion Assessment Tool-3 symptom scores, verbal memory, visual memory, visual-motor speed, or reaction time on the ImPACT (P > 0.004).

Conclusions

Tobacco users performed significantly worse than tobacco nonusers on the impulse control section of the ImPACT, reported greater symptom severity scores on the ImPACT, and were more likely to take risks as measured by the BSSS. Despite statistical significance, these results should be interpreted with caution, as the overall effect sizes were very small. Future research should examine the influence of tobacco use on recovery post-concussion.
Controlling and leveraging small-scale information in tomographic galaxy–galaxy lensing
Authors: MacCrann Niall , Blazek Jonathan , Jain Bhuvnesh , Krause Elisabeth
Published: October 2019

The tangential shear signal receives contributions from physical scales in the galaxy–matter correlation function well below the transverse scale at which it is measured. Since small scales are difficult to model, this non-locality has generally required stringent scale cuts or new statistics for cosmological analyses. Using the fact that uncertainty in these contributions corresponds to an uncertainty in the enclosed projected mass around the lens, we provide an analytic marginalization scheme to account for this. Our approach enables the inclusion of measurements on smaller scales without requiring numerical sampling over extra free parameters. We extend the analytic marginalization formalism to retain cosmographic (shear-ratio) information from small-scale measurements that would otherwise be removed due to modelling uncertainties, again without requiring the addition of extra sampling parameters. We test the methodology using simulated likelihood analysis of a Dark Energy Survey Year 5-like galaxy–galaxy lensing and galaxy clustering datavector. We demonstrate that we can remove parameter biases due to the presence of an unmodelled one-halo contamination of the galaxy–galaxy lensing signal, and use the shear-ratio information on small scales to improve cosmological parameter constraints.
H α morphologies of star clusters: a LEGUS study of H ii region evolution time-scales and stochasticity in low-mass clusters
Authors: Hannon Stephen , Lee Janice C , Whitmore B C , Chandar R , Adamo A , Mobasher B , Aloisi A , Calzetti D , Cignoni M , Cook D O , Dale D , Deger S , Della Bruna L , Elmegreen D M , Gouliermis D A , Grasha K , Grebel E K , Herrero A , Hunter D A , Johnson K E , Kennicutt R , Kim H , Sacchi E , Smith L , Thilker D , Turner J , Walterbos R A M , Wofford A
Published: October 2019

The morphology of H ii regions around young star clusters provides insight into the time-scales and physical processes that clear a cluster’s natal gas. We study ∼700 young clusters (≤10 Myr) in three nearby spiral galaxies (NGC 7793, NGC 4395, and NGC 1313) using Hubble Space Telescope (HST) imaging from LEGUS (Legacy ExtraGalactic Ultraviolet Survey). Clusters are classified by their H α morphology (concentrated, partially exposed, no-emission) and whether they have neighbouring clusters (which could affect the clearing time-scales). Through visual inspection of the HST images, and analysis of ages, reddenings, and stellar masses from spectral energy distributions fitting, together with the (U− B), (V − I) colours, we find (1) the median ages indicate a progression from concentrated (∼3 Myr), to partially exposed (∼4 Myr), to no H α emission (>5 Myr), consistent with the expected temporal evolution of H ii regions and previous results. However, (2) similarities in the age distributions for clusters with concentrated and partially exposed H α morphologies imply a short time-scale for gas clearing (≲1 Myr). Also, (3) our cluster sample’s median mass is ∼1000 M⊙, and a significant fraction ($\sim 20{{\ \rm per\ cent}}$) contain one or more bright red sources (presumably supergiants), which can mimic reddening effects. Finally, (4) the median E(B − V) values for clusters with concentrated H α and those without H α emission appear to be more similar than expected (∼0.18 versus ∼0.14, respectively), but when accounting for stochastic effects, clusters without H α emission are less reddened. To mitigate stochastic effects, we experiment with synthesizing more massive clusters by stacking fluxes of clusters within each H α morphological class. Composite isolated clusters also reveal a colour and age progression for H α morphological classes, consistent with analysis of the individual clusters.
MusE GAs FLOw and Wind (MEGAFLOW) – III. Galactic wind properties using background quasars
Authors: Schroetter Ilane , Bouché Nicolas F , Zabl Johannes , Contini Thierry , Wendt Martin , Schaye Joop , Mitchell Peter , Muzahid Sowgat , Marino Raffaella A , Bacon Roland , Lilly Simon J , Richard Johan , Wisotzki Lutz
Published: October 2019

We present results from our on-going MusE GAs FLOw and Wind (MEGAFLOW) survey, which consists of 22 quasar lines of sight, each observed with the integral field unit MUSE and the UVES spectrograph at the ESO Very Large Telescopes (VLT). The goals of this survey are to study the properties of the circumgalactic medium around z ∼ 1 star-forming galaxies. The absorption-line selected survey consists of 79 strong Mg ii absorbers (with rest-frame equivalent width ≳0.3 Å) and, currently, 86 associated galaxies within 100 projected kpc of the quasar with stellar masses (M⋆) from 109 to 1011 M⊙. We find that the cool halo gas traced by Mg ii is not isotropically distributed around these galaxies from the strong bi-modal distribution in the azimuthal angle of the apparent location of the quasar with respect to the galaxy major axis. This supports a scenario in which outflows are bi-conical in nature and co-exist with a co-planar gaseous structure extending at least up to 60–80 kpc. Assuming that absorbers near the minor axis probe outflows, the current MEGAFLOW sample allowed us to select 26 galaxy–quasar pairs suitable for studying winds. From this sample, using a simple geometrical model, we find that the outflow velocity only exceeds the escape velocity when M⋆ ≲ 4 × 109 M⊙, implying the cool material is likely to fall back except in the smallest haloes. Finally, we find that the mass loading factor η, the ratio between the ejected mass rate and the star formation rate, appears to be roughly constant with respect to the galaxy mass.
Evolution of atmospheric escape in close-in giant planets and their associated Ly α and H α transit predictions
Authors: Allan A , Vidotto A A
Published: October 2019

Strong atmospheric escape has been detected in several close-in exoplanets. As these planets consist mostly of hydrogen, observations in hydrogen lines, such as Ly α and H α, are powerful diagnostics of escape. Here, we simulate the evolution of atmospheric escape of close-in giant planets and calculate their associated Ly α and H α transits. We use a 1D hydrodynamic escape model to compute physical properties of the atmosphere and a ray tracing technique to simulate spectroscopic transits. We consider giant (0.3 and 1 Mjup) planets orbiting a solar-like star at 0.045 au, evolving from 10 to 5000 Myr. We find that younger giants show higher rates of escape, owing to a favourable combination of higher irradiation fluxes and weaker gravities. Less massive planets show higher escape rates (1010–1013 g s−1) than those more massive (109–1012 g s−1) over their evolution. We estimate that the 1-Mjup planet would lose at most 1 per cent of its initial mass due to escape, while the 0.3-Mjup planet, could lose up to 20 per cent. This supports the idea that the Neptunian desert has been formed due to significant mass-loss in low-gravity planets. At younger ages, we find that the mid-transit Ly α line is saturated at line centre, while H α exhibits transit depths of at most 3–4 per cent in excess of their geometric transit. While at older ages, Ly α absorption is still significant (and possibly saturated for the lower mass planet), the H α absorption nearly disappears. This is because the extended atmosphere of neutral hydrogen becomes predominantly in the ground state after ∼1.2 Gyr.
Prospects of cosmic superstring detection through microlensing of extragalactic point-like sources
Authors: Chernoff David F , Goobar Ariel , Renk Janina J
Published: October 2019

The existence of cosmic superstrings may be probed by astronomical time domain surveys. When crossing the line of sight to point-like sources, strings produce a distinctive microlensing signature. We consider two avenues to hunt for a relic population of superstring loops: frequent monitoring of (1) stars in Andromeda, lensed by loops in the haloes of the Milky-Way and Andromeda and (2) supernovae at cosmological distances, lensed by loops in the intergalactic medium. We assess the potential of such experiments to detect and/or constrain strings with a range of tensions, 10−15 ≲ Gμ/c2 ≲ 10−6. The practical sensitivity is tied to cadence of observations which we explore in detail. We forecast that high-cadence monitoring of ∼105 stars on the far side of Andromeda over a year-long period will detect microlensing events if Gμ/c2 ∼ 10−13, while ∼106 stars will detect events if 10−13.5 < Gμ/c2 < 10−11.5; the upper and lower bounds of the accessible tension range continue to expand as the number of stars rises. We also analyse the ability to reject models in the absence of fluctuations. While challenging, these studies are within reach of forthcoming time-domain surveys. Supernova observations can hypothetically constrain models with 10−12 < Gμ/c2 < 10−6 without any optimization of the survey cadence. However, the event rate forecast suggests it will be difficult to reject models of interest. As a demonstration, we use observations from the Pantheon Type Ia supernova cosmology data set to place modest constraints on the number density of cosmic superstrings in a poorly tested region of the parameter space.
Excision and Primary Reanastomosis of the Anterior Inferior Cerebellar Artery for Treatment of a Ruptured Mycotic Aneurysm: 2-Dimensional Operative Video
Authors: Mascitelli Justin , Gandhi Sirin , Cavallo Claudio , Baranoski Jacob , Meybodi Ali Tayebi , Lawton Michael T
Published: October 2019

Anterior inferior cerebellar artery (AICA) aneurysms are rare lesions with a predisposition for distal location and non-saccular morphology.
1,2
These aneurysms are less amenable to clipping and may instead require aneurysm trapping with bypass.
3
This video reports a novel bypass for a ruptured, fusiform distal AICA aneurysm. A 51-yr-old woman with newly diagnosed acquired immunodeficiency syndrome presented to the hospital with meningitis and experienced an acute neurological decline while admitted. Neuroimaging revealed a fusiform left a2-AICA aneurysm, thought to be mycotic with diffuse subarachnoid and intraventricular hemorrhage (Hunt-Hess Grade-IV). The occipital artery was harvested as an alternative donor in the myocutaneous flap using a hockey-stick incision. An extended retrosigmoid approach exposed the infectious aneurysm. After aneurysm excision, an a2-AICA-a2-AICA end-to-end reanastomosis was performed in between and deep to the vestibulocochlear nerves superiorly and the glossopharyngeal nerve inferiorly. Indocyanine green videoangiography and postoperative angiogram confirmed bypass patency. Postoperatively, she developed epidural and subdural hematomas due to human immunodeficiency virus-associated coagulopathy and/or increased aspirin sensitivity, requiring reoperation. The patient made a complete recovery at late follow-up. AICA reanastomosis is an elegant intracranial-intracranial bypass for treating distal AICA aneurysms. To our knowledge, this is the first report of AICA reanastomosis in the proximal a2-AICA (lateral pontine) segment. This technique has been reported in the literature for distally located aneurysms (a3-AICA).
4
Microanastomosis for more medial AICA aneurysms must be performed deep to the lower cranial nerves. OA to a3-AICA bypass is an alternative in cases where primary reanastomosis is not technically feasible. (Published with permission from Barrow Neurological Institute).
Diagnostic Accuracy of the Short Physical Performance Battery for Detecting Frailty in Older People
Authors: Perracini Monica R , Mello Mateus , de Oliveira Máximo Roberta , Bilton Tereza L , Ferriolli Eduardo , Lustosa Lygia P , da Silva Alexandre Tiago
Published: October 2019

Background

The Short Physical Performance Battery (SPPB) is widely used to predict negative health-related outcomes in older adults. However, the cutoff point for the detection of the frailty syndrome is not yet conclusive.

Objective

The aim of this study was to determine the diagnostic value of the SPPB for detecting frailty in community-dwelling older adults.

Design

This was a population-based cross-sectional study focusing on households in urban areas. A total of 744 people who were 65 years old or older participated in this study.

Methods

Frailty was determined by the presence of 3 or more of the following components: unintentional weight loss, self-reported fatigue, weakness, low level of physical activity, and slowness. Diagnostic accuracy measures of the SPPB cutoff points were calculated for the identification of frailty (individuals who were frail) and the frailty process (individuals who were considered to be prefrail and frail). Receiver operating characteristic curves were constructed. Odds ratios for frailty and the frailty process and respective CIs were calculated on the basis of the best cutoff points. A bootstrap analysis was conducted to confirm the internal validity of the findings.

Results

The best cutoff point for the determination of frailty was ≤  8 points (sensitivity = 79.7%; specificity = 73.8%; Youden J statistic = 0.53; positive likelihood ratio = 3.05; area under the curve = 0.85). The best cutoff point for the determination of the frailty process was ≤  10 points (sensitivity = 75.5%; specificity = 52.8%; Youden J statistic = 0.28; positive likelihood ratio = 1.59; area under the curve = 0.76). The adjusted odds of being frail and being in the frailty process were 7.44 (95% CI = 3.90–14.19) and 2.33 (95% CI = 1.65–3.30), respectively.

Limitations

External validation using separate data was not performed, and the cross-sectional design does not allow SPPB predictive capacity to be established.

Conclusions

The SPPB might be used as a screening tool to detect frailty syndrome in community-dwelling older adults, but the cutoff points should be tested in another sample as a further validation step.
Who Cared? Locating Caregivers in Chronicles of the Twelfth- and Thirteenth-Century Crusades1
Authors: Phillips Joanna
Published: October 2019

The crusades were religiously-inspired armed expeditions. Many of those who took the cross needed care of some sort: whether they were ill, impaired, wounded, starving or exhausted. However, any reference to medical practitioners—medici or physici in Latin terminology—is unusual in the sources for the crusader expeditions. But as the scholarship of pre-modern medical occupations has shown us, it was not only people identified with explicitly ‘medical’ terminology who attended to ill health in the medieval period. Newer historiographical developments go even further, to suggest utilising a framework of practice to interpret ‘care’ in a way that will be shown to be particularly apt for the crusader context. Through the analysis of incidents in the crusader narrative sources that describe the administration of bodily care, this article will show that practitioners qua caregivers can be found throughout the crusader host.