Does Beta React to Market Conditions? Estimates of Bull and Bear Betas using a Nonlinear Market Model with an Endogenous Threshold Parameter

We apply a logistic smooth transition market model (LSTM) to a sample of returns on Australian industry portfolios to investigate whether bull and bear market betas differ. Unlike other studies, our LSTM model allows for smooth transition between bull and bear states and allows the data to determine the threshold value. The estimated value of the smoothness parameter was very large for all industries implying that transition is abrupt. Therefore we estimated the threshold as a parameter along with the two betas in a dual beta market (DBM) framework using a sequential conditional least squares (SCLS) method. Using Lagrange Multiplier type tests of linearity, and the SCLS method our results indicate that for all but two industries the bull and bear betas are significantly different.Logistic Smooth Transition Market Model (LSTM); Sequential Conditional Least Squares (SCLS); Linearity Tests; Bull/Bear Betas

Does beta react to market conditions? Estimates of "bull" and "bear" betas using a nonlinear market model with an endogenous threshold parameter

The authors use a logistic smooth transition market (LSTM) model to investigate whether ‘bull’ and ‘bear’ market betas for Australian industry portfolios returns differ. The LSTM model allows the data to determine a threshold parameter that diffe

Effects of Training Intensity on Locomotor Performance in Individuals With Chronic Spinal Cord Injury: A Randomized Crossover Study

Background. Many physical interventions can improve locomotor function in individuals with motor incomplete spinal cord injury (iSCI), although the training parameters that maximize recovery are not clear. Previous studies in individuals with other neurologic injuries suggest the intensity of locomotor training (LT) may positively influence walking outcomes. However, the effects of intensity during training of individuals with iSCI have not been tested. Objective. The purpose of this pilot, blinded-assessor randomized trial was to evaluate the effects of LT intensity on walking outcomes in individuals with iSCI. Methods. Using a crossover design, ambulatory participants with iSCI \u3e1 year duration performed either high- or low-intensity LT for ≤20 sessions over 4 to 6 weeks. Four weeks following completion, the training interventions were alternated. Targeted intensities focused on achieving specific ranges of heart rate (HR) or ratings of perceived exertion (RPE), with intensity manipulated by increasing speeds or applying loads. Results. Significantly greater increases in peak treadmill speeds (0.18 vs 0.02 m/s) and secondary measures of metabolic function and overground speed were observed following high- versus low-intensity training, with no effects of intervention order. Moderate to high correlations were observed between differences in walking speed or distances and differences in HRs or RPEs during high- versus low-intensity training. Conclusion. This pilot study provides the first evidence that the intensity of stepping practice may be an important determinant of LT outcomes in individuals with iSCI. Whether such training is feasible in larger patient populations and contributes to improved locomotor outcomes deserves further consideration

Food Security & Civil Society

Findings from an in-depth qualitative investigation of Food Security with people from civil society organisations. A ‘boots on the ground’ perspective, which reveals the concerns about food security, and stakeholder evaluations of what they think needs to be done

SERUM VITAMIN D AND MAGNESIUM LEVELS IN A PSYCHIATRIC COHORT

Background: Both Vitamin D deficiency and magnesium deficiency have an increased prevalence and have been associated with an increased risk of and increased severity of symptoms in both depression and schizophrenia (Boerman 2016, Tarleton & Littenberg 2015). This effect appears more pronounced in younger populations and is often apparent from the time of initial diagnosis and is present with adjustment for confounding factors. Thus, the evidence suggests that Vitamin D and magnesium deficiency reflects not only dietary or somatic aspects of health but also may have a role in the pathophysiology of depression and schizophrenia. Subjects and methods: A single site audit of serum Vitamin D and magnesium levels in patients at an Acute Day Treatment Unit was carried out. Blood tests were performed on admission and analysed in house. Data were collected between April - June 2019 and was analysed subsequently, as described below (n=73). Results: Our data show that our psychiatric day treatment unit cohort (n=73) had a higher proportion of vitamin D deficiency (52%) than the general population (40%), although due to the limited sample size this was not significant (p=0.22, Chi-squared test). The percentage of patients who were magnesium deficient was 78.6% (n=22/28). However, the F60 subgroup of patients with personality disorders showed a high prevalence of vit D deficiency (p=0.07), highlighting a trend towards significance despite the limited size of this subgroup. Conclusions: We carried out a single-site audit of serum vitamin D and magnesium levels in a psychiatric day unit population in order to assess the extent of vitamin deficiency in such patients. These data indicate that that the proportion of patients with vitamin D deficiency is higher than in the general population. Further larger analysis is needed to establish the statistical significance of these data and whether treatment with vitamin D supplementation improves outcomes

The Chronic Kidney Disease in Africa (CKD-Africa) collaboration: Lessons from a new pan-African network

Chronic kidney disease (CKD) is a global public health problem, seemingly affecting individuals from low-income and-middle-income countries (LMICs) disproportionately, especially in sub-Saharan Africa. Despite the growing evidence pointing to an increasing prevalence of CKD across Africa, there has not been an Africa-wide concerted effort to provide reliable estimates that could adequately inform health services planning and policy development to address the consequences of CKD. Therefore, we established the CKD in Africa (CKD-Africa) Collaboration. To date, the network has curated data from 39 studies conducted in 12 African countries, totalling 35 747 participants, of which most are from sub-Saharan Africa. We are, however, continuously seeking further collaborations with other groups who have suitable data to grow the network. Although many successful research consortia exist, few papers have been published (with none from Africa) detailing the challenges faced and lessons learnt in setting up and managing a research consortium. Drawing on our experience, we describe the steps taken and the key factors required to establish a functional collaborative consortium among researchers in Africa. In addition, we present the challenges we encountered in building our network, how we managed those challenges and the benefit of such a collaboration for Africa. Although the CKD-Africa Collaboration is focused primarily on CKD research, many of the lessons learnt can be applied more widely in public health research in LMICs

Serum Vitamin D and Magnesium levels in a psychiatric cohort

Background: Both Vitamin D deficiency and magnesium deficiency have an increased prevalence and have been associated with an increased risk of and increased severity of symptoms in both depression and schizophrenia (Boerman 2016, Tarleton & Littenberg 2015). This effect appears more pronounced in younger populations and is often apparent from the time of initial diagnosis and is present with adjustment for confounding factors. Thus, the evidence suggests that Vitamin D and magnesium deficiency reflects not only dietary or somatic aspects of health but also may have a role in the pathophysiology of depression and schizophrenia. Subjects and methods: A single site audit of serum Vitamin D and magnesium levels in patients at an Acute Day Treatment Unit was carried out. Blood tests were performed on admission and analysed in house. Data were collected between April - June 2019 and was analysed subsequently, as described below (n=73). Results: Our data show that our psychiatric day treatment unit cohort (n=73) had a higher proportion of vitamin D deficiency (52%) than the general population (40%), although due to the limited sample size this was not significant (p=0.22, Chi-squared test). The percentage of patients who were magnesium deficient was 78.6% (n=22/28). However, the F60 subgroup of patients with personality disorders showed a high prevalence of vit D deficiency (p=0.07), highlighting a trend towards significance despite the limited size of this subgroup. Conclusions: We carried out a single-site audit of serum vitamin D and magnesium levels in a psychiatric day unit population in order to assess the extent of vitamin deficiency in such patients. These data indicate that that the proportion of patients with vitamin D deficiency is higher than in the general population. Further larger analysis is needed to establish the statistical significance of these data and whether treatment with vitamin D supplementation improves outcomes