Stock Market Interdependence: Evidence from Australia

This study examines the relationship between Australia’s stock market and the five largest international markets for the period 1991 through 2001. Preliminary findings, using correlation statistics, indicated potential benefits to international diversification for the Australian investor. Further analysis, conducted in the VAR framework using the Johansen co-integration method, found that the Australian market has short and long run linkages with the United States, while tests with other markets found little evidence of interdependence. Moreover, only the US market was found to Grangercause the Australian market.Interdependence, price linkages, internationalisation.

A Solar Tornado Observed by AIA/SDO: Rotational Flow and Evolution of Magnetic Helicity in a Prominence and Cavity

During 2011/09/24, as observed by the Atmospheric Imaging Assembly (AIA) instrument of the Solar Dynamic Observatory (SDO) and ground-based \Ha\ telescopes, a prominence and associated cavity appeared above the southwest limb. On 2011/09/25 8:00UT material flows upwards from the prominence core along a narrow loop-like structure, accompanied by a rise ($\geq$50,000km) of the prominence core and the loop. As the loop fades by 10:00, small blobs and streaks of varying brightness rotate around the top part of the prominence and cavity, mimicking a cyclone. The most intense and coherent rotation lasts for over three hours, with emission in both hot ($\sim$1MK) and cold (hydrogen and helium) lines. We suggest that the cyclonic appearance and overall evolution of the structure can be interpreted in terms of the expansion of helical structures into the cavity, and the movement of plasma along helical structures which appears as a rotation when viewed along the helix axis. The coordinated movement of material between prominence and cavity suggest that they are structurally linked. Complexity is great due to the combined effect of these actions and the line-of-sight integration through the structure which contains tangled fields.Comment: 4 pages, 5 figures, accepted by ApJ Letter

Impact of Cardiorespiratory Fitness on Markers of Cardiovascular Disease in Professional Firefighters

Higher cardiorespiratory fitness (CRF) levels (V̇O2max) are associated with lower oxidative stress and inflammatory markers in addition to lower cardiovascular disease (CVD) risk; however, there are a lack of data examining this relationship among firefighters. CVD is the leading cause of mortality among firefighters and correlates with low CRF. PURPOSE: To examine differences in markers of CVD risk between firefighters classified as having either high or low levels of CRF. METHODS: Forty-six professional firefighters performed a maximal graded exercise test (GXT; Bruce Protocol), where V̇O2max was estimated from the Foster equation using time to exhaustion. Fasted blood samples were also taken to assess traditional and non-traditional biomarkers of CVD risk: HDL, LDL, glucose, cholesterol, triglycerides, advanced oxidation protein products (AOPP), homeostatic model assessment for insulin resistance (HOMA-IR) and C-reactive protein (CRP). Body fat percentage (BF%) was determined via Dual-Energy X-Ray Absorptiometry (DEXA),V̇O2max values were categorized based on American College of Sports Medicine (ACSM) guidelines to establish a high fitness group (n=19; V̇O2max = 44.7 ± 5.2 ml·kg-1·min-1; age = 35.94 ± 9.73 yrs; height = 178.86 ± 7.28 cm; waist circumference = 35.5 ± 2.73 cm; BF% = 19.9 ± 2.66) and a low fitness group (n=27; V̇O2max = 28.2 ± 4.9ml·kg-1·min-1; age = 38.5 ± 9.33 yrs; height = 179.21 ± 8.48 cm; waist circumference = 40.06 ± 4.29 cm; BF% = 27.2 ± 5.07). Non-parametric Mann-Whitney U tests were used to assess differences in CVD risk markers between the high and low fitness groups. Effect sizes were calculated as Cohen’s d (i.e., small [0.2-0.5], medium [0.5-0.8], large [\u3e 0.8]). RESULTS: Participants classified as high fitness had significantly (p \u3c 0.05) higher V̇O2max and HDL concentrations coupled with significantly lower BF%, cholesterol, triglycerides, LDL, insulin, HOMA-IR, CRP, and AOPP. Half of the observed differences demonstrated a medium effect size (LDL, insulin, HOMA-IR, CRP, and AOPP), while large effect sizes were noted for V̇O2max, BF%, cholesterol, triglycerides, HDL, LDL/HDL risk ratio. CONCLUSION: The high fitness group exhibited lower CVD risk levels and higher HDL levels compared to the low fitness group. Considering the results, firefighters are encouraged to maintain high CRF as well as lower BF% in an effort to reduce the risk of CVD and on-duty cardiac events

Relationship Between Body Composition, Body Fat Distribution, and Blood Lipids Among Law Enforcement Officers: Part 2

Law enforcement officers (LEOs) have a high-stress occupation, which is prone to cardiovascular disease (CVD). Data suggest a 1.7-fold higher CVD prevalence versus the general public, in addition to 40.5% of LEOs being classified as obese. Emerging evidence suggests that lipid-related atherosclerotic risk may be better captured by including advanced blood lipid panels (i.e., cholesterol particle type and size). However, there needs to be more research regarding the relationship between body composition, body fat distribution, and advanced blood lipid panels concerning CVD risk in LEOs. PURPOSE: To determine if body composition and fat distribution measures correlate with predictive advanced lipid markers in LEOs. METHODS: Forty-three LEOs (male: n=40; Female: n=3; age = 41.7±9.6 yrs; weight = 91.9±15.4 kg; height = 179.8±8.7 cm; VO2max: 37.0±6.1 ml/kg/min) from a local police department were evaluated. Fasting blood samples were collected to assess biomarkers of CVD risk: number of low-density lipoprotein particles (LDL-p), small LDL-p, LDL size (LDL-s), number of high-density lipoprotein particles (HDL-p), large HDL-p, HDL size (HDL-s), number of very low-density lipoprotein particles (VLDL-p), and VLDL size (VLDL-s). Dual-energy x-ray absorptiometry was used to measure body composition. Bivariate Pearson correlation matrix and ordinary least squares (OLS) regression analyses were used to examine the relationship between body composition and fat distribution. RESULTS: The Bivariate Pearson correlation matrix revealed higher body weight, lean mass, visceral adipose tissue, and gynoid adiposity correlated with several advanced lipid biomarkers. The OLS regression analysis revealed Body weight to be positively predictive (p\u3c0.05) of LDL-p and small LDL-p but inversely predictive (p\u3c0.05) of LDL-s, large HDL-p, and HDL-s; Lean mass to be positively predictive of LDL-p, small LDL-p, but inversely predictive of LDL-s, HDL-p, large HDL-p, and HDL-s; Visceral adipose tissue to be positively predictive of small LDL-p and large VLDL-p, but inversely predictive of LDL-s, large HDL-p, and HDL-s; and gynoid fat distribution to be positively predictive of HDL-p, large HDL-p, and HDL-s. CONCLUSION: Changes in body composition seen in LEOs with increased weight and fat distribution showed correlations with advanced blood lipid markers, which can be predictive of high CVD risk and other potential medical conditions. These data provide insight into the association of body composition and fat distribution with markers of CVD risk (i.e., advanced blood lipids)

Predictors of Cardiometabolic Disease Risk Factors in Professional Firefighters

The leading cause of mortality (~50% of deaths) among on-duty firefighters is sudden cardiac death. Firefighters with adequate cardiorespiratory fitness levels (among other muscular fitness metrics) and lower body fat percentage (BF%) are likely to better combat on-duty cardiac events and cardiovascular disease (CVD) risk. Individuals with higher VO2max values may be at lower risk noted by lower oxidative stress and inflammatory biomarkers, which may be more ideal predictors of CVD risk compared to traditional biomarkers (i.e., blood glucose and lipids) among the fire community; however, more research is needed to elucidate. PURPOSE: This study examined the relationship between fitness metrics, body fat percentage, and traditional and non-traditional biomarkers among professional firefighters. METHODS: Ninety-eight professional, male firefighters (age = 36.26 ± 9.08 yrs; height = 179.53 ± 7.06 cm; waist circumference = 37.99 ± 4.13 cm; BF% = 24.39 ± 5.21; years of experience = 11.81 ± 8.00 yrs) from a local fire department were studied VO2max was estimated from total treadmill exercise time using the Foster equation.. Fitness metrics including muscular strength, endurance, and power variables were also measured. Fasted blood samples were analyzed for concentrations of lipids, glucose, insulin resistance (HOMA-IR), advanced oxidation protein products (AOPP), and ultra-sensitive C-reactive protein (CRP). To assess the relationship between fitness metrics and AOPP, CRP, and HOMA-IR, ordinary least square regression analyses were used. RESULTS: VO2max values were inversely (p \u3c 0.05) related to AOPP, HOMA-IR, and CRP. Waist circumference was positively correlated to AOPP concentrations and HOMA-IR, while increased BF% was significantly related to increased CRP concentrations. CONCLUSION: High VO2max values were significantly related to lower AOPP, CRP, and HOMA-IR. Additionally, high waist circumference and BF% values were related to increases in oxidative stress, inflammation, and insulin resistance. Firefighters are encouraged to maintain high cardiorespiratory fitness (VO2max) and lower BF% to reduce CVD and, ultimately, on-duty sudden cardiac death risk

Statistical Learning Methods to Predict Activity Intensity from Body-Worn Accelerometers

 Physical activity, especially when performed at moderate or vigorous intensity, has short- and long-term health benefits, but measurement of free-living physical activity is challenging. Accelerometers are popular tools to assess physical activity, although accuracy of conventional accelerometer analysis methods is suboptimal. This study developed and tested statistical learning models for assessing activity intensity from body-worn accelerometers. Twenty-eight adults performed 10-21 activities of daily living in two visits while wearing four accelerometers (right hip, right ankle, both wrists). Accelerometer placement is of crucial practical concern and this paper addresses this issue. Boosting, bagging, random forest and decision tree models were created for each accelerometer and for two-, three-, and four-accelerometer combinations to predict activity intensity. Research staff observations of activity intensity served as the criterion. Point estimates of error for the ankle accelerometer were 2.2-4.7 percentage points lower than other single-accelerometer placements, and the left wrist-ankle combination had errors 0.8-5.8 percentage points lower than other two-accelerometer combinations. Decision trees had poorer accuracy than the other models. Using an accelerometer worn on the lower limb, by itself or in combination with an upper-limb accelerometer, appears to offer optimal accuracy for activity intensity measurement

Relationship Between Body Composition, Body Fat Distribution, and Blood Lipids Among Law Enforcement Officers: Part 1

Law enforcement officers (LEOs) have a high-stress occupation which is prone to cardiovascular disease (CVD). In fact, data suggest that LEOs have a 1.7-fold higher CVD prevalence versus the general public, in addition to 40.5% of LEOs being classified as obese. However, research is lacking regarding the relationship between body composition, body fat distribution, and blood lipid panels as it pertains to CVD risk in LEOs. PURPOSE: To determine if body composition and fat distribution measures correlate with predictive lipid markers in LEOs. METHODS: Forty-three LEOs (age = 41.7±9.6 yrs; weight = 91.9±15.4 kg; height = 179.8±8.7 cm; VO2max: 37.0±6.16 ml/kg/min) from a local police department were evaluated. Fasting blood samples were collected to assess biomarkers of CVD risk: low-density lipoprotein (LDL), high-density lipoprotein (HDL), total cholesterol (TC), and triglycerides (TG). Dual-energy x-ray absorptiometry was used to measure body composition and body fat distribution. Bivariate Pearson correlation matrix was used to determine correlations (p\u3c0.05* and p\u3c0.01**). To further assess the relationship between body composition, fat distribution measures, and blood lipids, ordinary least square (OLS) regression analyses were used. RESULTS: Lower body weight correlated with greater HDL concentrations (r=-0.432**). Higher fat mass correlated with greater TG concentrations (r=0.338*), while greater lean mass was inversely correlated with HDL concentrations (r=-0.496**). Android and gynoid adiposity were positively correlated with greater TG (r=0.359*) and HDL (r=0.320*) concentrations, respectively. Lastly, higher visceral adipose tissue was correlated with greater TG concentrations (r=0.430**). The OLS regression analysis revealed (p\u3c0.05) 1) weight was inversely predictive of HDL, 2) Fat mass was positively predictive of TG, 3) lean mass was inversely predictive of HDL, 4) android adiposity was positively predictive of TG, 5) gynoid adiposity was positively predictive of HDL, and 6) visceral adipose tissue was positively predictive of TG. CONCLUSION: Measures of body composition seen in LEOs with increased body fat showed positive correlations with blood lipid markers (TG and HDL), which can be predictive of high CVD risk and other potential medical conditions. These data provide insight into the association of body composition and fat distribution with markers of CVD risk

Neuroanatomical Correlates of the Income-Achievement Gap

In the United States, the difference in academic achievement between higher- and lower-income students (i.e., the income-achievement gap) is substantial and growing. In the research reported here, we investigated neuroanatomical correlates of this gap in adolescents (N = 58) in whom academic achievement was measured by statewide standardized testing. Cortical gray-matter volume was significantly greater in students from higher-income backgrounds (n = 35) than in students from lower-income backgrounds (n = 23), but cortical white-matter volume and total cortical surface area did not differ significantly between groups. Cortical thickness in all lobes of the brain was greater in students from higher-income than lower-income backgrounds. Greater cortical thickness, particularly in temporal and occipital lobes, was associated with better test performance. These results represent the first evidence that cortical thickness in higher- and lower-income students differs across broad swaths of the brain and that cortical thickness is related to scores on academic-achievement tests.Bill & Melinda Gates FoundationNational Institutes of Health (U.S.) (Grant F32 HD079143-01)National Institutes of Health (U.S.) (Grant F32 MH095354-01

An immunoinformatics-derived DNA vaccine encoding human class II T cell epitopes of Ebola virus, Sudan virus, and Venezuelan equine encephalitis virus is immunogenic in HLA transgenic mice

Immunoinformatics tools were used to predict human leukocyte antigen (HLA) class II-restricted T cell epitopes within the envelope glycoproteins and nucleocapsid proteins of Ebola virus (EBOV) and Sudan virus (SUDV) and the structural proteins of Venezuelan equine encephalitis virus (VEEV). Selected epitopes were tested for binding to soluble HLA molecules representing 5 class II alleles (DRB1*0101, DRB1*0301, DRB1*0401, DRB1*0701, and DRB1*1501). All but one of the 25 tested peptides bound to at least one of the DRB1 alleles, and 4 of the peptides bound at least moderately or weakly to all 5 DRB1 alleles. Additional algorithms were used to design a single “string-of-beads” expression construct with 44 selected epitopes arranged to avoid creation of spurious junctional epitopes. Seventeen of these 44 predicted epitopes were conserved between the major histocompatibility complex (MHC) of humans and mice, allowing initial testing in mice. BALB/c mice vaccinated with the multi-epitope construct developed statistically significant cellular immune responses to EBOV, SUDV, and VEEV peptides as measured by interferon (IFN)-γ ELISpot assays. Significant levels of antibodies to VEEV, but not EBOV, were also detected in vaccinated BALB/c mice. To assess immunogenicity in the context of a human MHC, HLA-DR3 transgenic mice were vaccinated with the multi-epitope construct and boosted with a mixture of the 25 peptides used in the binding assays. The vaccinated HLA-DR3 mice developed significant cellular immune responses to 4 of the 25 (16%) tested individual class II peptides as measured by IFN-γ ELISpot assays. In addition, these mice developed antibodies against EBOV and VEEV as measured by ELISA. While a low but significant level of protection was observed in vaccinated transgenic mice after aerosol exposure to VEEV, no protection was observed after intraperitoneal challenge with mouse-adapted EBOV. These studies provide proof of concept for the use of an informatics approach to design a multi-agent, multi-epitope immunogen and provide a basis for further testing aimed at focusing immune responses toward desired protective T cell epitopes

A Parallel Autonomy Research Platform

We present the development of a full-scale “parallel autonomy” research platform including software and hardware. In the parallel autonomy paradigm, the control of the vehicle is shared; the human is still in control of the vehicle, but the autonomy system is always running in the background to prevent accidents. Our holistic approach includes: (1) a driveby-wire conversion method only based on reverse engineering, (2) mounting of relatively inexpensive sensors onto the vehicle, (3) implementation of a localization and mapping system, (4) obstacle detection and (5) a shared controller as well as (6) integration with an advanced autonomy simulation system (Drake) for rapid development and testing. The system can operate in three modes: (a) manual driving, (b) full autonomy, where the system is in complete control of the vehicle and (c) parallel autonomy, where the shared controller is implemented. We present results from extensive testing of a full-scale vehicle on closed tracks that demonstrate these capabilities