Magnetic Field Strength Effects on Nucleosynthesis from Neutron Star Merger Outflows

Magnetohydrodynamic turbulence drives the central engine of post-merger remnants, potentially powering both a nucleosynthetically active disk wind and the relativistic jet behind a short gamma ray burst. We explore the impact of the magnetic field on this engine by simulating three post-merger black hole accretion disks using general relativistic magnetohydrodynamics with Monte Carlo neutrino transport, in each case varying the initial magnetic field strength. We find increasing ejecta masses associated with increasing magnetic field strength. We find that a fairly robust main r -process pattern is produced in all three cases, scaled by the ejected mass. Changing the initial magnetic field strength has a considerable effect on the geometry of the outflow and hints at complex central engine dynamics influencing lanthanide outflows. We find that actinide production is especially sensitive to magnetic field strength, with overall actinide mass fraction calculated at 1 Gyr post-merger increasing by more than a factor of six with a tenfold increase in magnetic field strength. This hints at a possible connection to the variability in actinide enhancements exhibited by metal poor, r -process-enhanced stars

Do Elliptical Trainers Accurately Estimate Energy Expenditure?

Life Fitness and Precor elliptical exercise trainers are very popular in fitness centers because of the reduced impact on joints as compared to running on a treadmill. Modern elliptical trainers measure heart rate, distance traveled, and provide an estimated amount of calories expended during the exercise bout. Each piece of equipment uses an internal algorithm to estimate energy expenditure based upon resistance and pedal rate. The purpose of this study was to determine if the PRECOR model EFX 556i and Life Fitness model 95X elliptical trainers accurately estimated energy expenditure. Three men and three women performed exercise sessions on each elliptical trainer on 3 separate occasions (2 bouts per day). The order of the machines used for each exercise session was randomized. Each exercise bout lasted 12 minutes (2-min warmup at a resistance of 3, rpm of 70; 10-min measure period at a resistance of 10, rpm of 70). During the test V02 was measured using a Medical Graphics Ultima metabolic cart; heart rate was measured using a Polar heart rate monitor and energy expenditure calculated by the metabolic cart. HR, VO2, and energy expenditure data were recorded each minute of the 10 minute exercise session. The results are shown in the table below. Brand Elliptical Mean (Kcal) MC Mean (Kcal) % Error P Value LF 91 (13.98) 93.54 (14.13) -2.72 0.024 PC 122.93 (12.74) 98.58 (12.68) 24.70 \u3c0.0001 LF = Life Fitness, PC = Precor, MC = Medical Graphics Ultima metabolic cart We conclude that the Life Fitness EFX 556i slightly underestimates, while the Precor model EFX 556i overestimates exercise energy expenditure

Non-growing follicle density is increased following adriamycin, bleomycin, vinblastine and dacarbazine (ABVD) chemotherapy in the adult human ovary

Funded by UK Medical Research Council Grants G0901839 and MR/L00299X/1.Study question: Do the chemotherapeutic regimens of ABVD (adriamycin, bleomycin, vinblastine and dacarbazine) or OEPA-COPDAC (combined vincristine, etoposide, prednisone, doxorubicin (OEPA) and cyclophosphamide, vincristine, prednisone, dacarbazine (COPDAC)) used to treat Hodgkin lymphoma (HL), affect the density, morphology and in vitro developmental potential of human ovarian follicles? Summary answer: Ovarian tissue from women treated with ABVD contained a higher density of non-growing follicles (NGFs) per cubic millimetre and increased numbers of multiovular follicles but showed reduced in vitro growth compared with patients with lymphoma who had not received chemotherapy, patients treated with OEPA-COPDAC, age-matched healthy women and age-related model-predicted values. What is known already: Chemotherapy regimens can cause a loss of follicles within the ovary that depends on the drugs given. Early stage HL is commonly treated by ABVD, a non-alkylating regimen which apparently has ovarian sparing qualities, thus it is important to investigate the histological appearance and distribution of follicles within ABVD-treated ovarian tissue. Study design, size, duration: Thirteen ovarian biopsies were obtained from HL patients (6 adolescents and 7 adults) and one biopsy from a non-HL patient. Two HL patients and the non-HL patient had received no treatment prior to biopsy collection. The remaining 11 HL patients received one of two regimens; ABVD or OEPA-COPDAC. Tissue was analysed histologically and compared to biopsies from healthy women, and in a sub-group of patients, tissue was cultured for 6 days in vitro. Participants/materials, setting, methods: Ovarian biopsies were obtained from patients undergoing ovarian cryopreservation for fertility preservation, and from healthy women at the time of Caesarian section (‘obstetric tissue’). Follicle number and maturity were evaluated in sections of ovarian cortical tissue, and compared to an age-related model of mean follicle density and to age-matched contemporaneous biopsies. The developmental potential of follicles was investigated after 6 days tissue culture. Main results and the role of chance: A total of 6877 follicles was analysed. ABVD-treated tissue contained a higher density of non-growing follicles/mm3 (230±17) (mean±SEM) than untreated (110±54), OEPA-COPDAC-treated (50±27 and obstetric tissue (20±4)(P< 0.01),with follicle density 9-21 standard deviations higher than predicted by an age-related model. Bi-ovular and binucleated non-growing follicles occurred frequently in ABVD-treated and in adolescent untreated tissue but were not observed in OEPA-COPDAC-treated or obstetric tissue, although OEPA-COPDAC-treated tissue contained a high proportion of morphologically abnormal oocytes (52% versus 23% in untreated, 22% in ABVD-treated and 25% in obstetric tissue; P< 0.001). Activation of follicle growth in vitro occurred in all groups, but in ABVD-treated samples there was very limited development to the secondary stage, whilst in untreated samples from lymphoma patients growth was similar to that observed in obstetric tissue (untreated; P< 0.01 versus ABVD-treated, ns versus obstetric). Large scale data: N/A Limitations, reasons for caution: Although a large number of follicles were analysed, these data were derived from a small number of biopsies. The mechanisms underpinning these observations have yet to be determined and it is unclear how they relate to future fertility. Wider implications of the findings: This study confirms that the number of NGFs is not depleted following ABVD treatment, consistent with clinical data that female fertility is preserved. Our findings demonstrate that immature follicle density can increase as well as decrease following at least one chemotherapy treatment. This is the first report of morphological and follicle developmental similarities between ABVD-treated tissue and the immature human ovary. Further experiments will investigate the basis for the marked increase in follicle density in ABVD-treated tissue.PostprintPeer reviewe

Energy Expenditure Overestimation Bias in Elliptical Trainer Machine

Elliptical trainers are a common mode of aerobic exercise in recreationally active populations. Those with a weight loss goal might rely upon the energy expenditure (EE) estimation that many elliptical brands provide to keep track of calories (kcals) burned and make nutritional decisions. For this reason, it is important to evaluate the accuracy of the algorithms used by elliptical trainers to estimate EE. The purpose of this study was to compare EE estimates by a common brand of elliptical trainer to that measured using open circuit spirometry, at different combinations of resistance and pedal speed. Twenty subjects (10 male, 10 female; 34 ± 12 yr; 175.3 ± 10.7 cm; 77.1 ± 14.1 kg) consented to participate. Each completed three 15-min bouts of elliptical exercise on the same elliptical trainer, with at least 24 hr between exercise bouts. Pedal rates were held constant throughout each bout at 50, 60, or 70 RPM, and resistance was increased incrementally every 5 min from level 5 to 10 to 15. The different cadences were completed in a randomized order between participants. Expired gases were collected continuously throughout the 15 min. Heart rate, distance (mi), and EE from the elliptical readout were recorded every 1 min. RPE was collected twice per resistance level. A two-tailed paired samples t-test was used to compare elliptical EE to measured EE. A linear regression model was used to evaluate the ability of the elliptical EE to predict measured EE. Significance for all statistical measures was held at an alpha level of 0.05. The difference between EE estimates from the elliptical and measured VO2 was significant (p Measured EE = 0.95*(Elliptical EE) – 3.161 In conclusion, the elliptical trainer used for this study demonstrated a bias to overestimate EE. This should be taken into account by health/fitness professionals using these estimations to program for clients. There may be some variation in the EE correction regression depending on elliptical model, and proper machine calibration should be ensured

Predicting VO2max in Collegiate American-Style Football Athletes

Introduction: Maximal oxygen uptake (VO2max) is an important measurement for athletic performance. A common method of VO2max prediction is the Foster equation (MSSE, 1996). This equation produces accurate predictions in a normal population, however, significant difference has been noted between predicted and measured VO2max values when testing athletes. While other studies have produced new equations for athletes in general or even for soccer players, to our knowledge none have made one specifically for American-style football players. Purpose: The aim of this study is to develop an accurate VO2max prediction equation for collegiate American-style football athletes for testing on the treadmill with the standard Bruce protocol. Methods: Over 13 years, a total of 413 collegiate American football players (age: 18.5±1.15 yrs, height: 186.8±7.0 cm, weight 102.1±20.8 kg) were assessed for VO2max (Medical Graphics, Corp® Metabolic Cart) using the standard Bruce treadmill protocol. Linear regression analysis (JMP v. 12) determined which factor out of height, weight, or time spent on the test had a greater impact on VO2max. The linear regression analysis of the most significant factor against VO2max produced a prediction equation. Predicted VO2max was calculated using these data in both the Foster equation and this novel equation. Predicted values were compared to actual measured values with a t-test. α=0.05 for all statistical tests. Results: Of all the factors, time had the strongest relationship (p\u3c0.0001; r2=0.6464). The linear regression between VO2max and time produced a prediction equation: VO2max= -3.546 + 3.904(time in minutes). Both the Foster equation and this new equation were significantly and positively correlated with the actual VO2max values (Foster=0.805, New r=0.804). However, t-tests indicate that the Foster equation results were significantly different from the measured values (p=0.0007), and the new model’s results were not significantly different (p=1.0). Conclusion: The Foster equation is not a reliable predictor of VO2max as assessed on a treadmill in collegiate American-style football athletes. This new equation is more accurate to predict VO2max in this population

Superheavy Elements in Kilonovae

As LIGO-Virgo-KAGRA enters its fourth observing run, a new opportunity to search for electromagnetic counterparts of compact object mergers will also begin. The light curves and spectra from the first "kilonova" associated with a binary neutron star binary (NSM) suggests that these sites are hosts of the rapid neutron capture ("$r$") process. However, it is unknown just how robust elemental production can be in mergers. Identifying signposts of the production of particular nuclei is critical for fully understanding merger-driven heavy-element synthesis. In this study, we investigate the properties of very neutron rich nuclei for which superheavy elements ($Z\geq 104$) can be produced in NSMs and whether they can similarly imprint a unique signature on kilonova light-curve evolution. A superheavy-element signature in kilonovae represents a route to establishing a lower limit on heavy-element production in NSMs as well as possibly being the first evidence of superheavy element synthesis in nature. Favorable NSMs conditions yield a mass fraction of superheavy elements is $X_{Z\geq 104}\approx 3\times 10^{-2}$ at 7.5 hours post-merger. With this mass fraction of superheavy elements, we find that kilonova light curves may appear similar to those arising from lanthanide-poor ejecta. Therefore, photometric characterizations of superheavy-element rich kilonova may possibly misidentify them as lanthanide-poor events.Comment: 9 pages, 5 figure

The Relationships between Fitness Assessments, Fitness Levels and Coronary Heart Disease Risk Markers in Police Officers

Given the physical nature of a position in law enforcement, the assessment of cardiovascular (CV) health as well as muscular strength and endurance is paramount to ensuring the safety of these personnel and the citizens they serve. The present study retrospectively examined correlations between several markers of CV and muscular fitness for 65 local police officers (8 female, average age 35.6 ± 9.0 yrs, height 70.5 ± 2.8 in, weight 91.8 ± 18.7 kg, VO2 33.0 ± 5.3 mL/kg/min) taken from their annual screening including a graded exercise test (GXT; Bruce protocol), pushups completed in 1 minute, situps completed in 1 minute, handgrip strength, body composition (through DEXA and circumference measures) and bloodwork. Maximal oxygen uptake (VO2max) was estimated using the Foster equation. Coronary heart disease risk (CHD risk) was calculated using the online NIH 10-year heart attack risk calculator, which uses age, gender, total cholesterol, HDL cholesterol, smoking status, and blood pressure status in its algorithm. Significance was determined using an alpha level of 0.05. Interestingly, there was no significant correlation between VO2max and CHD risk (p = 0.1851). Apart from risk markers included in the risk calculation, CHD risk was significantly correlated with waist-hip ratio (r = 0.24739), and LDL cholesterol (r = 0.39117). VO2max was significantly negatively correlated with fat mass (r = -0.51849), body fat percentage (%BF; r = -0.64297), total cholesterol (TC; r = -0.3371), and LDL cholesterol (r = -0.267). Positive correlations were found between VO2max and other measures of fitness such as pushups (r = 0.54274), situps (r = 0.3282), and handgrip strength (r = 0.32041). As for body composition measures, %BF was significantly positively correlated with TC (r = 0.30188), systolic blood pressure (r = 0.28795), LDL cholesterol (r = 0.26533), and fasting glucose (r = 0.26536), but negatively correlated with fitness markers such as pushups (r = -0.58599), situps (r = -0.43604), and handgrip strength (r = -0.32393). Lean mass was significantly correlated with handgrip strength (r = 0.71835), though not pushups, situps or VO2max. Waist circumference was significantly negatively correlated with HDL cholesterol (r = -0.39202). Additionally, 62 of the participants (7 female) completed both a 1.5 mile run and GXT, allowing for a comparison of a submaximal to a maximal fitness assessment of CV fitness. Time to complete 1.5 miles was significantly correlated to GXT VO2max, with a Pearson correlation coefficient of -0.79593. Overall, relationships found between health markers, fitness, and CHD risk in this sample were in line with previous research on CHD risk factors and the assessment of CV and muscular fitness

Residents\u27 Perceptions of Community and Environmental Impacts From Development of Natural Gas in the Marcellus Shale: A Comparison of Pennsylvania and New York Cases

Communities experiencing rapid growth due to energy development (‘boomtowns’) have reported positive and negative impacts on community and individual well-being. The perceptions of impacts vary according to stage of energy development as well as experience with extractive industries. Development of the Marcellus Shale provides an opportunity to examine these impacts over time and across geographic and historical contexts. This paper describes case study research in Pennsylvania and New York to document preliminary impacts of development occurring there. Cases vary by level of development and previous extractive history. The study finds that, in areas with low population density, higher levels of development lead to a broader awareness of natural gas impacts, both positive and negative. Participants draw from the regional history of extraction to express environmental concern despite direct, local experience. Our findings suggest the need to track these perceptions during development, and as individuals and communities react and adapt to the impacts