A Small BVAR-DSGE Model for Forecasting the Australian Economy

This paper estimates a small structural model of the Australian economy, designed principally for forecasting the key macroeconomic variables of output growth, underlying inflation and the cash rate. In contrast to models with purely statistical foundations, which are often used for forecasting, the Bayesian Vector Autoregressive Dynamic Stochastic General Equilibrium (BVAR-DSGE) model uses the theoretical information of a DSGE model to offset in-sample over-fitting. We follow the method of Del Negro and Schorfheide (2004) and use a variant of the small open economy DSGE model of Lubik and Schorfheide (2007) to provide prior information for the VAR. The forecasting performance of the model is competitive with benchmark models such as a Minnesota VAR and an independently estimated DSGE model.BVAR-DSGE; forecasting

Exercise Completed When Young Provides Lifelong Benefit to Cortical Bone Structure and Estimated Strength

poster abstractExercise induces greatest bone gains during growth, yet reduced bone strength is an age-related phenomenon. This raises the question of whether exercise-induced bone changes when young persist into adulthood. The current studies used Major/Minor League Baseball (MLB/MiLB) players to explore whether exercise-induced gains in humeral bone structure and strength accrued when young persist lifelong. MLB/MiLB players are a unique model as the unilateral upper extremity loading associated with throwing enables the contralateral side to serve as an internal control site and former MLB/MiLB players were consistently exposed to extreme loading reducing secular variations in exercise levels between generations. Dominant-to-nondominant (D-to-ND) differences in humeral cross-sectional properties in MLB/MiLB players were normalized to matched controls to correct for side-to-side differences due to elevated habitual loading associated with arm dominance. Exercise when young induced significant skeletal benefits, with active MLB/MiLB players having nearly double the estimated ability to resist torsion (polar moment of inertia, IP) in the humerus of their dominant arm. The cortical bone mass and area benefits of exercise observed in active MLB/MiLB players were lost in former MLB players following 40-49 years of detraining as a result of elevated medullary expansion and endocortical trabecularization. However, 42% of the total bone area benefit persisted following 50+ years of detraining and contributed to the maintenance of 24% of the benefit on IP. In MLB players who continued to exercise during aging, medullary expansion and endocortical trabecularization were reduced and there was maintenance of the cortical bone mass and area benefits of exercise. These cumulative data indicate: 1) the extreme plasticity of the growing skeleton to exercise; 2) that exercise when young has lifelong benefits on cortical bone size and estimated strength, but not bone mass, and; 3) exercise continued during aging maintains the bone mass benefits of exercise

Baseball and softball pitchers are distinct within-subject controlled models for exploring proximal femur adaptation to physical activity

Purpose: Within-subject controlled models in individuals who preferentially load one side of the body enable efficient exploration of the skeletal benefits of physical activity. There is no established model of physical activity-induced side-to-side differences (i.e., asymmetry) at the proximal femur. Methods: Proximal femur asymmetry was assessed via dual-energy x-ray absorptiometry in male jumping athletes (JMP, n=16), male baseball pitchers (BB, n=21), female fast-pitch softball pitchers (SB, n=22), and controls (CON, n=42). The jumping leg was the dominant leg in JMP, whereas in BB, SB and CON the dominant leg was contralateral to the dominant/throwing arm. Results: BB and SB had 5.5% (95%CI, 3.9 to 7.0%) and 6.5% (95%CI, 4.8 to 8.2%) dominant-to-nondominant leg differences for total hip areal bone mineral density (aBMD), with the asymmetry being greater than both CON and JMP (p8%) dominant-to-nondominant leg differences in cross-sectional area, cross-sectional moment of inertia and section modulus, which were larger than any other group (p≤0.02). Conclusion: Male baseball and female softball pitchers are distinct within-subject controlled models for exploring adaptation of the proximal femur to physical activity. They exhibit adaptation in their dominant/landing leg (i.e., leg contralateral to the throwing arm), but the pattern differs with softball pitchers exhibiting greater femoral neck adaptation

Age-Related Changes in Proximal Humerus Bone Health in White Males

poster abstractThe proximal humerus is a common site for osteoporotic fracture during aging, accounting for up to 5% of fractures to the appendicular skeleton. While falls onto an outstretched hand are usually physically responsible for proximal humerus fractures, the ability of the underlying bone to resist applied loads must also play a role. Few studies have assessed proximal humerus bone health with aging. The aim of the current study was to explore age-related bone changes at the proximal humerus in men. A cross-sectional study design was used to assess peripheral quantitative computed tomography (pQCT)-derived bone properties of the proximal humerus in a cohort of 112 white males (age range = 30-85 yrs). A tomographic slice of the non-dominant upper extremity was acquired at 80% of humeral length proximal from its distal end—a location corresponding to the surgical neck of the humerus. Images were assessed for cortical (Ct.BMC) and trabecular (Tb.BMC) BMC, total (Tt.Ar), cortical (Ct.Ar) and medullary (Me.Ar) area, periosteal (Ps.Pm) and endosteal (Es.Pm) perimeter, cortical thickness (Ct.Th), and bone strength index for compression (BSIc). BSIc was calculated as the product of Tt.Ar and the square of total volumetric BMD. Data were plotted against age and linear regression lines assessed for their slope. Slopes were subsequently converted to percent change in the bone property per year. During aging, the proximal humerus expanded with Tt.Ar and Ps.Pm increasing at rates of 0.40%/yr and 0.19%/yr, respectively. However, Me.Ar (0.62%/yr) and Es.Pm (0.34%/yr) expanded at faster rates such that there was net loss of both Ct.BMC (-0.23%/yr) and Tb.BMC (-1.08%/yr). Also, the more rapid expansion of Me.Ar relative to Tt.Ar meant that Ct.Ar (-0.15%/yr) and Ct.Th (-0.34%/yr) both decreased with age. The net result of these mass and structural changes was progressive loss of bone strength with age, as indicated by a 0.44%/yr decline in BSIc. These data provide a picture of bone changes at the proximal humerus during aging. They suggest that between age 30 and 80 yrs, approximately 54% and 11% of Tb.BMC and Ct.BMC at the proximal humerus is lost, respectively. They also suggest that compressive strength of the proximal humerus declines by 22% between age 30 and 80 years. These declines in proximal humerus bone health have implications for fracture risk at this location during aging

Comprehensive Analysis of Copy Number Variation of Genes at Chromosome 1 and 10 Loci Associated with Late Age Related Macular Degeneration

Copy Number Variants (CNVs) are now recognized as playing a significant role in complex disease etiology. Age-related macular degeneration (AMD) is the most common cause of irreversible vision loss in the western world. While a number of genes and environmental factors have been associated with both risk and protection in AMD, the role of CNVs has remained largely unexplored. We analyzed the two major AMD risk-associated regions on chromosome 1q32 and 10q26 for CNVs using Multiplex Ligation-dependant Probe Amplification. The analysis targeted nine genes in these two key regions, including the Complement Factor H (CFH) gene, the 5 CFH-related (CFHR) genes representing a known copy number “hotspot”, the F13B gene as well as the ARMS2 and HTRA1 genes in 387 cases of late AMD and 327 controls. No copy number variation was detected at the ARMS2 and HTRA1 genes in the chromosome 10 region, nor for the CFH and F13B genes at the chromosome 1 region. However, significant association was identified for the CFHR3-1 deletion in AMD cases (p = 2.38×10−12) OR = 0.31, CI-0.95 (0.23–0.44), for both neovascular disease (nAMD) (p = 8.3×10−9) OR = 0.36 CI-0.95 (0.25–0.52) and geographic atrophy (GA) (p = 1.5×10−6) OR = 0.36 CI-0.95 (0.25–0.52) compared to controls. In addition, a significant association with deletion of CFHR1-4 was identified only in patients who presented with bilateral GA (p = 0.02) (OR = 7.6 CI-0.95 1.38–41.8). This is the first report of a phenotype specific association of a CNV for a major subtype of AMD and potentially allows for pre-diagnostic identification of individuals most likely to proceed to this end stage of disease