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A class of games for finding a leader among a group of candidates is studied in detail. This class covers games based on coin tossing and rock-paper-scissors as special cases and its complexity exhibits similar stochastic behaviors: either of logarithmic mean and bounded variance or of exponential mean and exponential variance. Many applications are also discussed. [ABSTRACT FROM AUTHOR]

This paper analyzes the tradeoff between cost and risk of discretely rebalanced option hedges in the presence of transactions costs. I present closed form solutions for expected hedging error, transactions costs, and variance of the cash flow from a time-based hedging strategy similar to that analyzed by Leland (1985). Furthermore, I characterize the cost and risk of a move-based hedging strategy without resorting to Monte Carlo simulations. All results are sufficiently general to accommodate the use of a transactions costs adjusted hedging volatility and an asset rate of return that differs from the risk-free rate of return. [ABSTRACT FROM AUTHOR]

Background: Contrasting the well-described effects of early intervention (EI) services for youth-onset psychosis, the potential benefits of the intervention for adult-onset psychosis are uncertain. This paper aims to examine the effectiveness of EI on functioning and symptomatic improvement in adult-onset psychosis, and the optimal duration of the intervention. Methods: 360 psychosis patients aged 26–55 years were randomized to receive either standard care (SC, n = 120), or case management for two (2-year EI, n = 120) or 4 years (4-year EI, n = 120) in a 4-year rater-masked, parallel-group, superiority, randomized controlled trial of treatment effectiveness (Clinicaltrials.gov: NCT00919620). Primary (i.e. social and occupational functioning) and secondary outcomes (i.e. positive and negative symptoms, and quality of life) were assessed at baseline, 6-month, and yearly for 4 years. Results: Compared with SC, patients with 4-year EI had better Role Functioning Scale (RFS) immediate [interaction estimate = 0.008, 95% confidence interval (CI) = 0.001–0.014, p = 0.02] and extended social network (interaction estimate = 0.011, 95% CI = 0.004–0.018, p = 0.003) scores. Specifically, these improvements were observed in the first 2 years. Compared with the 2-year EI group, the 4-year EI group had better RFS total (p = 0.01), immediate (p = 0.01), and extended social network (p = 0.05) scores at the fourth year. Meanwhile, the 4-year (p = 0.02) and 2-year EI (p = 0.004) group had less severe symptoms than the SC group at the first year. Conclusions: Specialized EI treatment for psychosis patients aged 26–55 should be provided for at least the initial 2 years of illness. Further treatment up to 4 years confers little benefits in this age range over the course of the study. [ABSTRACT FROM AUTHOR]

Various studies suggest that the maritime industry will continue to face the challenge of seafarer shortages. Young seafarer turnover has become a serious issue that cannot be underestimated. This paper aims to identify the root causes of young seafarer attrition in China and explore relevant solutions. It collects information via semi-structured interviews and questionnaires. Independent sample t-test, one-way ANOVA and least-significant difference are utilised for the variance analysis. The findings of the study show that occupational recognition and family responsibility are the two major factors contributing to young seafarers' outflow. Chinese seafarers' health status is another important factor that has received little attention. In addition, young seafarers of 31–35 years old have the most possibility of turnover, due to a number of reasons discussed in this paper. Age 40 or thereabouts is viewed as the watershed moment in a seafarer's career, so efforts should be made to help young seafarers pass through the hard period in their early thirties. This paper suggests that a clear career plan could be a potential solution to retain this backbone group as prospective senior officers. [ABSTRACT FROM AUTHOR]

This paper reexamines and extends the work of Ben Horim and Levy [1], which argued that risk decomposition should be based on standard deviation rather than on variance. Their analysis showed that decomposition of variance is wrong when β < 0 and that, in general, this procedure produces incorrect estimates of undiversifiable risk. This paper shows that these conclusions also apply to the no-risk-free asset extended CAPM if risk is adjusted for the unavoidable risk associated with the global minimum variance portfolio. [ABSTRACT FROM AUTHOR]

Studies of size and earnings/price ratio effects together have produced contradictory results. Does one effect subsume the other or are there two separate effects?. This paper demonstrates that equity returns are related to both size and earnings/price ratio as well as the month of January. Reinganum [20] and Basu [4] are reexamined to find the reasons for their contradictory results. Reinganum's finding that size subsumes earnings/price ratio is caused by a fortuitous choice of methods. Basu's finding that earnings/price ratio subsumes size appears to be sample-specific. This paper examines the implied standard deviation (ISD) estimated from transactions data on options, using the Black-Scholes pricing model. It was found that the distribution of the ISD is symmetric, though not normal. Also, the ISD based on the last daily observation deviates significantly from the daily average ISD. It is suggested that the daily average is a more reliable estimate of the standard deviation. [ABSTRACT FROM AUTHOR]

The article reports on beta as a random coefficient and discusses the paper, "Beta as a Random Coefficient," by Frank J. Fabozzi and Jack Clark Francis. Fabozzi and Francis' work suggests that beta as a random coefficient is a significant minority in stocks of the New York Stock Exchange (NYSE). Their evidence is taken through characterizing the market model as a random coefficient model and by estimating its parameters in a sampling of NYSE stocks between December 1965 and December 1971. Their methodology is analyzed and it is found that they overstated the use of beta as a random coefficient.

The article discusses the influence of uncertainty or inflation on mean-variance equilibrium that will prove that the market portfolio is nonefficient. The author claims that the paper addresses theoretical issues involving multivariate analysis of nominal returns in a situation where investors are concerned with real wealth optimization. The author suggests that if inflation does have an impact on asset returns, then the consideration of capital asset pricing models cannot yield a perfect or positive answer. The article addresses portfolio efficiency and special cases of a nominal riskfree asset.

The Eetscore FFQ was developed to score the Dutch Healthy Diet index 2015 (DHD2015-index) representing the Dutch food-based dietary guidelines of 2015. This paper describes the development of the Eetscore FFQ, a short screener assessing diet quality, examines associations between diet quality and participants' characteristics, and evaluates the relative validity and reproducibility of the Eetscore FFQ in a cross-sectional study with Dutch adults. The study sample consisted of 751 participants, aged 19–91 years, recruited from the EetMeetWeet research panel. The mean DHD2015-index score based on the Eetscore FFQ of the total sample was 111 (sd 17·5) out of a maximum score of 160 points and was significantly higher in women than in men, positively associated with age and education level, and inversely associated with BMI. The Kendall's tau-b coefficient of the DHD2015-index between the Eetscore FFQ and the full-length FFQ (on average 1·7-month interval, n 565) was 0·51 (95 % CI 0·47, 0·55), indicating an acceptable ranking ability. The intraclass correlation coefficient between DHD2015-index scores derived from two repeated Eetscore FFQ (on average 3·8-month interval, n 343) was 0·91 (95 % CI 0·89, 0·93) suggesting a very good reproducibility. In conclusion, the Eetscore FFQ was considered acceptable in ranking participants according to their diet quality compared with the full-length FFQ and showed good to excellent reproducibility. [ABSTRACT FROM AUTHOR]

This paper proposes an analytical method of solving the inverse kinematic problem for a humanoid manipulator with five degrees-of-freedom (DOF) under the condition that the target orientation of the manipulator's end-effector is not constrained around an axis fixed with respect to the environment. Since the number of the joints is less than six, the inverse kinematic problem cannot be solved for arbitrarily specified position and orientation of the end-effector. To cope with the problem, a generalized unconstrained orientation is introduced in this paper. In addition, this paper conducts the singularity analysis to identify all singular conditions. [ABSTRACT FROM AUTHOR]

Despite the increased attention paid to federal-state unemployment insurance (UI) schemes after the Great Recession (2007–2009), research examining the policy characteristics and the underlying logic shaping the social protection provided by a federal-state UI system is limited. Integrating the perspectives of policy design theory, comparative welfare politics, and fiscal welfare, this paper examines the unequal social protection under the American UI system during and after the Great Recession. By using model-based cluster analysis and fixed-effect panel regression models, this paper identifies three distinct UI approaches, i.e. the limited social protection approach, the unbalanced social protection approach, and the balanced social protection approach. The policy choices made by those states that follow the three approaches reflect different mixtures of policy logic, including social protection, economic stabilization, work disincentives, and interstate competition. The overall downward trend in social protection signals that the American UI system is under-prepared for the next economic recession, thereby exposing unemployed workers to the risk of economic insecurity. These findings provide implications for future policy designs aiming to strengthen the social protection of the federal-state UI system. [ABSTRACT FROM AUTHOR]

In this paper we propose a model for biological neural nets where the activity of the network is described by Hawkes processes having a variable length memory. The particularity in this paper is that we deal with an infinite number of components. We propose a graphical construction of the process and build, by means of a perfect simulation algorithm, a stationary version of the process. To implement this algorithm, we make use of a Kalikow-type decomposition technique. Two models are described in this paper. In the first model, we associate to each edge of the interaction graph a saturation threshold that controls the influence of a neuron on another. In the second model, we impose a structure on the interaction graph leading to a cascade of spike trains. Such structures, where neurons are divided into layers, can be found in the retina. [ABSTRACT FROM PUBLISHER]

This paper examines estimation issues associated with multivariate tests of asset pricing. Two issues are considered: (1) the constraint that the sample size (N) must be less than the time series (T), and (2) the relative effect on power of using the multivariate statistic versus a univariate counterpart. We find that an alternative statistic that allows for large N does not dominate the usual portfolio tests. More notably, we find that the power of a simple diagonal statistic usually dominates the multivariate statistic for cases considered in this study. [ABSTRACT FROM AUTHOR]

The primary objective of this paper is to derive a multi-factor equilibrium model using a mean-variance approach. The results of this derivation provide greater insight into the nature of the resulting factors than does APT. There are several important implications for empirical tests of any a priori defined multi-factor model. [ABSTRACT FROM AUTHOR]

This paper examines the implied standard deviation (ISD) estimated from transactions data on options, using the Black-Scholes pricing model. It was found that the distribution of the ISD is symmetric, though not normal. Also, the ISD based on the last daily observation deviates significantly from the daily average ISD. It is suggested that the daily average is a more reliable estimate of the standard deviation. [ABSTRACT FROM AUTHOR]

This paper has presented a method for generating fairly realistic and tractable discrete state probability distributions of security returns from a market model that employed a discrete approximation to normally distributed market returns. This technique was employed to generate state return distributions for a variety of actual securities and portfolios. The operational feasibility off the suggestion was investigated by computing GO and MV investment policies for various specifications of the state return distribution. The investment policies were then compared to determine whether the GO and MV models are empirically identical when returns are approximately normal, as is often claimed in the literature. The key result indicated that for a given state probability distribution there are pronounced differences in the GO and MV investment policies measured either in terms of the assets chosen—i.e., the number of assets chosen, the individual assets chosen, and, hence, the mix of risky assets—or the forecasted expected returns and the standard deviations of the optimal unlevered portfolios. In addition, very short computational times were involved in solving the investment problems, particularly the GO problem. If the results prove to be robust, there appear to be two rather interesting implications. First, the forecasting and solution techniques suggested for the GO model may prove to be a small first step in formulating expected-utilitybased investment problems that can be used by real-world investors. In other words, in terms of operating feasibility with further refinement, the simple twist on Sharpe's diagonal model idea and a good numerical analysis routine may do for the expected utility model what the diagonal model did for the operational feasibility of the MV model. Second, it is often stated that, with exact multivariate normality and a risk-free rate, there is no difference in the unlevered GO and MV portfolios. Given that the statement is... [ABSTRACT FROM AUTHOR]

In this paper, we have presented the exact probabilities of correctly concluding dominance by the criterion of EV for normal populations with n = 10(10)50 and ρ = 0. We have also studied the influence of correlation on the effectiveness of the EV criterion (and indirectly on the SSD criterion). We have shown that positive correlation always increases the effectiveness of EV when the populations differ. Negative correlation reduces the effectiveness of EV when the variances are equal; it increases its effectiveness when the means are equal but the variances differ. When the means and variances both differ, negative correlation has an indeterminate effect on the EV criterion. Our results show that the investor's work is not done when the EV criterion identifies an "efficient" solution. An "efficient" solution is efficient only with respect to the model used to represent the investor's problem; such a solution becomes a reliable guide for action only after it has been verified as performing well for other reasonable representations of the problem as well. For these reasons we have in a sense performed a sensitivity analysis to investigate the effect on the efficient solution due to sampling error. We have seen that estimation risk can affect the efficiency analysis seriously, with consequent choices for the investor that provide unsatisfactory expected utility. [ABSTRACT FROM AUTHOR]

Recent theoretical and empirical work in portfolio theory has exhibited a natural evolution from the two-moment EV model popularized by Markowitz through the higher moment models to selection on the basis of the entire probability function. This latter approach, referred to as the Stochastic Dominance (SD) approach to portfolio selection, has been shown to be theoretically superior to all of the "moment methods" and has been the focus of an increasing volume of empirical work. In comparison with the EV model, however, the SD approach has one potentially significant deficiency from the standpoint of empirical testing. With a given set of portfolios to evaluate, the computer processor time required for the determination of the EV efficient set is quite short. One can calculate and sort means and variances on several hundred portfolios in a matter of seconds. In contrast, the processor time required for the determination of the SD efficient set for the same number of portfolios can be prohibitive. The purpose of this paper is to examine the factors responsible for the relatively time-consuming nature of empirical tests of SD efficiency and to present the major results of our search for efficient algorithms for conducting SD tests. Section I briefly examines the time-consuming nature of the tests for SD efficiency. Section II presents and evaluates; our most efficient algorithms for obtaining true SD efficiency results. Section lit examines an approach that yields approximate SD efficiency results with further reductions in required processor time. [ABSTRACT FROM AUTHOR]

The objectives of this paper are to derive the relationship of the geometric mean of a distribution of positive values to the conventional first four moments — arithmetic mean, variance, absolute skewness, and absolute kurtosis — and to empirically evaluate certain approximations involving these four moments for estimating the geometric means of monthly and annual holding period returns for individual stocks and for portfolios. The geometric mean is shown to be positively related to the arithmetic mean and absolute skewness and negatively related to variance and absolute kurtosis. In the case of a normal distribution a very good approximation to the geometric mean is revealed to be a function of just the arithmetic mean and variance. Additionally, empirical evidence indicates that even though a number of the monthly and annual distributions deviate significantly from normality, the approximation involving only the mean and variance produces quite accurate estimates of the geometric means of these distributions. [ABSTRACT FROM AUTHOR]

In this paper we consider an Ornstein-Uhlenbeck (OU) process (M(t))t≥0 whose parameters are determined by an external Markov process (X(t))t≥0 on a finite state space {1, . . . , d}; this process is usually referred to as Markov-modulated Ornstein- Uhlenbeck. We use stochastic integration theory to determine explicit expressions for the mean and variance of M(t). Then we establish a system of partial differential equations (PDEs) for the Laplace transform of M(t) and the state X(t) of the background process, jointly for time epochs t = t1, . . . , tK. Then we use this PDE to set up a recursion that yields all moments of M(t) and its stationary counterpart; we also find an expression for the covariance between M(t) and M(t+u). We then establish a functional central limit theorem for M(t) for the situation that certain parameters of the underlying OU processes are scaled, in combination with the modulating Markov process being accelerated; interestingly, specific scalings lead to drastically different limiting processes. We conclude the paper by considering the situation of a single Markov process modulating multiple OU processes. [ABSTRACT FROM AUTHOR]

In this paper, we formally show that the cross-sectional variance of stock returns is a consistent and asymptotically efficient estimator for aggregate idiosyncratic volatility. This measure has two key advantages: It is model free and observable at any frequency. Previous approaches have used monthly model-based measures constructed from time series of daily returns. The newly proposed cross-sectional volatility measure is a strong predictor for future returns on the aggregate stock market at the daily frequency. Using the cross section of size and book-to-market portfolios, we show that the portfolios’ exposures to the aggregate idiosyncratic volatility risk predict the cross section of expected returns. [ABSTRACT FROM PUBLISHER]

Crop scientists occasionally compute sample correlations between traits based on observed data from designed experiments, and this is often accompanied by significance tests of the null hypothesis that traits are uncorrelated. This simple approach does not account for effects due to the randomization layout and treatment structure of the experiments and hence statistical inference based on standard procedures is not appropriate. The present paper describes how valid inferences accounting for all relevant effects can be obtained using bivariate mixed linear model procedures. A salient feature of the approach is that the bivariate model is commensurate with the model used for univariate analysis of individual traits and allows bivariate correlations to be computed at the level of effects. Heterogeneity of correlations between effects can be assessed by likelihood ratio tests or by graphical inspection of bivariate scatter plots of effect estimates. if heterogeneity is found to be substantial, it is crucial to focus on the correlation of effects, and usually, the main interest will be in the treatment effects. If heterogeneity is judged to be negligible, the marginal correlation can be estimated from the bivariate model for an overall assessment of association. The proposed methods are illustrated using four examples. Hints are given to alternative routes of analysis accounting for all treatment and design effects such as regression with groups and analysis of covariance. [ABSTRACT FROM PUBLISHER]

Objective: This study compares the detection rates of haemoglobin absorption spectral imaging and white light imaging in laryngeal papilloma surgery. Methods: Seventeen patients with laryngeal papilloma who underwent surgery in our department from September 2019 to September 2021 were selected. All patients underwent carbon dioxide laser surgery under a microscope. The lesion sites were explored in white light mode and haemoglobin absorption spectral imaging mode. The pharynx and larynx anatomical sites were evaluated using Derkay's all-position scoring system. The numbers and scores for lesions observed in the two modes were compared. Results: In 17 cases, there were statistically significant differences in the numbers of laryngeal papillomas (Derkay score) detected by white light mode and haemoglobin absorption spectral imaging mode. In 9 of 17 patients (52.94 per cent), the haemoglobin absorption spectral imaging mode showed additional diseased tissues. Conclusion: The haemoglobin absorption spectral imaging mode can dynamically identify diseased tissues in carbon dioxide laser surgery under a microscope and improve the laryngeal papilloma detection rate. [ABSTRACT FROM AUTHOR]

Pricing variance swaps have become a popular subject recently, and most research of this type come under Heston’s two-factor model. This paper is an extension of some recent research which used the dimension-reduction technique based on the Heston model. A new closed-form pricing formula focusing on a log-return variance swap is presented here, under the assumption that the underlying asset prices can be described by a mean-reverting Gaussian volatility model (Ornstein–Uhlenbeck process). Numerical tests in two respects using the Monte Carlo (MC) simulation are included. Moreover, we discuss a procedure of solving a quadratic differential equation with one variable. Our method can avoid the previously encountered limitations, but requires more time for calculation than other recent analytical discrete models. [ABSTRACT FROM AUTHOR]

This paper considers adaptive hypothesis testing for the fractional differencing parameter in a parametric ARFIMA model with unconditional heteroskedasticity of unknown form. A weighted score test based on a nonparametric variance estimator is proposed and shown to be asymptotically equivalent, under the null and local alternatives, to the Neyman-Rao effective score test constructed under Gaussianity and known variance process. The proposed test is therefore asymptotically efficient under Gaussianity. The finite sample properties of the test are investigated in a Monte Carlo experiment and shown to provide potentially large power gains over the usual unweighted long memory test. [ABSTRACT FROM AUTHOR]

Objective: The role of high-resolution computed tomography scans in otosclerosis remains uncertain. There is a debate over the relationship between radiological and audiometric findings among patients. Method: Pre-operative audiometry and high-resolution computed tomography findings from 40 ears with surgically confirmed otosclerosis were compared. High-resolution computed tomography scan data regarding the characteristics of the disease foci, the endosteal extension and the occurrence of internal auditory canal diverticula were obtained. The influence of each radiological variable on the simple pure tone average, the high-frequency pure tone average and the bone-conduction pure tone average were investigated. Results: Cases with endosteal extension (p = 0.047) and a higher number of affected sites within the otic capsule had a worse bone-conduction pure tone average, although it was only significant for the latter (p = 0.006). Those without concomitant retrofenestral disease (p = 0.019) had better simple pure tone average. Conclusion: The number of sites of involvement and concomitant retrofenestral disease seem to significantly impact audiometric findings in otosclerosis. [ABSTRACT FROM AUTHOR]

This paper performs specification analysis on the term structure of variance swap rates on the S&P 500 index and studies the optimal investment decision on the variance swaps and the stock index. The analysis identifies 2 stochastic variance risk factors, which govern the short and long end of the variance swap term structure variation, respectively. The highly negative estimate for the market price of variance risk makes it optimal for an investor to take short positions in a short-term variance swap contract, long positions in a long-term variance swap contract, and short positions in the stock index. [ABSTRACT FROM AUTHOR]

This paper examines time-series forecast errors of expected returns from conditional and unconditional asset pricing models for portfolio and individual firm equity returns. A new result that increases predictive precision concerning model specification and forecasting is introduced. Conditional versions of the models generally produce higher mean squared errors than unconditional versions for step ahead prediction. This holds for individual firm data when the instruments are firm specific. Mean square forecast error decompositions indicate that the asset pricing models produce relatively unbiased predictions, but the variance is severe enough to ruin the step ahead predictive ability beyond that of a constant benchmark. [ABSTRACT FROM AUTHOR]

In this paper we provide a perturbation analysis of finite time-inhomogeneous Markov processes. We derive closed-form representations for the derivative of the transition probability at time t , with t > 0. Elaborating on this result, we derive simple gradient estimators for transient performance characteristics either taken at some fixed point in time t , or for the integrated performance over a time interval [0, t]. Bounds for transient performance sensitivities are presented as well. Eventually, we identify a structural property of the derivative of the generator matrix of a Markov chain that leads to a significant simplification of the estimators. [ABSTRACT FROM AUTHOR]

When designing programs to assist the poor, it is important to recognize who is most in need of government assistance. Although measures of poverty are often based on income alone, poverty measures based on both income and assets provide greater precision in the analysis of this group since accumulated assets can be liquidated to compensate for temporary shortfalls in income. The current study used the Panel Study of Income Dynamics (2007–2017) to analyze associations between different facets of poverty dynamics (i.e. poverty entry and exit) and its determinants. We explored differences in results based on whether poverty was measured by income alone, or income plus assets. The Cox proportional hazard regression was used to examine how demographic characteristics predicted poverty entry and poverty exit. Results indicated factors predicting poverty entry were not identical to those predicting difficulty of exiting poverty. Also, the risk of poverty entry and exit differed based on whether poverty was measured by income alone, or income plus assets. Thus, using income plus assets provides new perspectives into poverty dynamics which past research, based on income alone, did not provide. These new insights can be used to inform decisions about policies for poverty prevention and alleviation. [ABSTRACT FROM AUTHOR]

Camelina cake (CAM) is a co-product proposed as an alternative protein source; however, piglet data are still limited. This study aimed to evaluate the effect of different doses of CAM in substitution of soyabean meal on the growth, health and gut health of weaned pigs. At 14 d post-weaning (d0), sixty-four piglets were assigned either to a standard diet or to a diet with 4 %, 8 % or 12 % of CAM. Piglets were weighed weekly. At d7 and d28, faeces were collected for microbiota and polyamine and blood for reactive oxygen metabolites (ROM) and thyroxine analysis. At d28, pigs were slaughtered, organs were weighed, pH was recorded on gut, colon was analysed for volatile fatty acids (VFA) and jejunum was used for morphological and gene expression analysis. Data analysis was carried out using a mixed model including diet, pen and litter as factors; linear and quadratic contrasts were tested. CAM linearly reduced the average daily gain from d0–d7, d0–d14, d0–d21 and d0–d28 (P ≤ 0·01). From d0–d7 increasing CAM linearly decreased feed intake (P = 0·04) and increased linearly the feed to gain (P = 0·004). CAM increased linearly the liver weight (P < 0·0001) and affected the cadaverine (P < 0·001). The diet did not affect the ROM, thyroxine, intestinal pH, VFA and morphology. All doses of CAM increased the α diversity indices at d28 (P < 0·05). CAM at 4 % promoted the abundance of Butyricicoccaceae_UCG-008. Feeding with CAM enhanced resilience in the gut microbiome and can be evaluated as a potential alternative protein source with dose-dependent limitations on piglet growth performance. [ABSTRACT FROM AUTHOR]

Non-alcoholic fatty liver disease (NAFLD), which is a prevalent hepatic condition worldwide, is expected to develop into the leading reason for end-stage fatty liver in the forthcoming decades. Incorporating rapeseed oil into a balanced diet may be beneficial in improving NAFLD. The goal of this trial was to evaluate the impact of substituting ghee with rapeseed oil on primary outcomes such as fatty liver and liver enzymes, as well as on secondary outcomes including glycaemic variables, lipid profile and anthropometric measurements in individuals with NAFLD. Over 12 weeks, 110 patients (seventy men and forty women; BMI (mean) 28·2 (sd 1·6 kg/m2); mean age 42 (sd 9·6) years), who daily consumed ghee, were assigned to the intervention or control group through random allocation. The intervention group was advised to substitute ghee with rapeseed oil in the same amount. The control group continued the consumption of ghee and was instructed to adhere to a healthy diet. Results showed a significant reduction in the steatosis in the intervention group in comparison with the control group (P < 0·001). However, a significant change in the levels of alanine aminotransferase (–14·4 μg/l), γ-glutamyl transferase (–1·8 μg/l), TAG (–39·7 mg/dl), total cholesterol (–17·2 mg/dl), LDL (–7·5 mg/dl), fasting blood glucose (–7·5 mg/dl), insulin (–3·05 mU/l), Homeostatic Model Assessment for Insulin Resistance (–0·9), Quantitative Insulin-Sensitivity Check Index (+0·01), weight (–4·3 kg), BMI (–0·04 kg/m2), waist (–5·6 cm) and waist:height ratio (–0·04) was seen in the intervention group. The consumption of rapeseed oil instead of ghee caused improvements in liver steatosis and enzymes, glycaemic variables and anthropometric measurements among individuals with NAFLD. [ABSTRACT FROM AUTHOR]

Background: Adolescence is a key developmental period for the emergence of psychopathology. Reward-related brain activity increases across adolescence and has been identified as a potential neurobiological mechanism of risk for different forms of psychopathology. The reward positivity (RewP) is an event-related potential component that indexes reward system activation and has been associated with both concurrent and family history of psychopathology. However, it is unclear whether the RewP is also associated with higher-order psychopathology subfactors and whether this relationship is present across different types of reward. Methods: In a sample of 193 adolescent females and a biological parent, the present study examined the association between adolescent and parental psychopathology subfactors and adolescent RewP to monetary and social reward. Results: Results indicated that the adolescent and parental distress subfactors were negatively associated with the adolescent domain-general RewP. The adolescent and parental positive mood subfactors were negatively associated with the adolescent domain-general and domain-specific monetary RewP, respectively. Conversely, the adolescent and parental fear/obsessions subfactors were positively associated with the adolescent domain-general RewP. The associations between parental and adolescent psychopathology subfactors and the adolescent RewP were independent of each other. Conclusions: The RewP in adolescent females is associated with both concurrent and parental psychopathology symptoms, suggesting that it indexes both severity and risk for higher-order subfactors. [ABSTRACT FROM AUTHOR]

Many seed quality tests are conducted by first randomly assigning seeds into replicates of a given size. The replicate results are then used to check whether or not any problems occur in the realization of the test. The two main tools developed for this verification are the ratio of the observed variance of the replicate results to a theoretical variance and the tolerance for the range of the results. In this paper, we derive the theoretical distribution and its related properties of the sequence of numbers of seeds with a given quality attribute present in the replicates. From these theoretical results, we revisit the two quality checking tools widely used for the germination test. We show a precaution to be taken when relying on the variance ratio to check for under- or over-dispersion of the replicate results. This has led to the development of tables providing credible intervals of the variance ratio. The International Seed Testing Association tolerance tables for the range of the results are also compared with tolerances computed from the exact theoretical distribution of the range, leading us to recommend a revision of these tables. [ABSTRACT FROM AUTHOR]

Background.: This paper reviews the efficacy of a community psychosocial arts program focused on building mental health capacity within post-Ebola Liberia. The aim of this paper was to evaluate the outcome effects of two groups using pre- and post-treatment data. We hypothesized that there would be a difference in symptoms pre- and post-treatment, and the longer program would yield more significant results. Methods.: There was a total of 870 child participants. Of 40 sites, 24 were selected for a 5-month treatment (TG1) while the remaining 16 sites received 3 months of treatment (TG2). Paired t tests and a mixed-model analysis of variance (ANOVA) were used to analyse pre- and post-psychological stress symptoms (PSS) for samples from both groups. Results.: Separately, treatment group 1 (TG1) and treatment group 2's (TG2) paired t test yielded significant results (p < 0.001) for the decrease of PSS. The mixed-model ANOVA found that there were significant differences in total pre- and post-test PSS and a significant difference in PSS means over time. Conclusions.: Results indicated that there was a statistically significant decrease in reported symptoms in both treatment groups pre- to post-intervention and a significant difference in total symptoms over time. However, the findings do not indicate that the longer programming was statistically different compared to the shorter programming. The study presented had gaps in data, largely due to limits in research during the crisis. However, this paper provides a unique case study for challenges that can be faced for project evaluation in emergency settings. [ABSTRACT FROM AUTHOR]

This paper deals with the first passage optimality and variance minimisation problems of discrete-time Markov decision processes (MDPs) with varying discount factors and unbounded rewards/costs. First, under suitable conditions slightly weaker than those in the previous literature on the standard (infinite horizon) discounted MDPs, we establish the existence and characterisation of the first passage expected-optimal stationary policies. Second, to further distinguish the expected-optimal stationary policies, we introduce the variance minimisation problem, prove that it is equivalent to a new first passage optimality problem of MDPs, and, thus, show the existence of a variance-optimal policy that minimises the variance over the set of all first passage expected-optimal stationary policies. Finally, we use a computable example to illustrate our main results and also to show the difference between the first passage optimality here and the standard discount optimality of MDPs in the previous literature. [ABSTRACT FROM AUTHOR]

The main result of this paper is the solution to the optimal stopping problem of maximizing the variance of a geometric Lévy process. We call this problem the variance problem. We show that, for some geometric Lévy processes, we achieve higher variances by allowing randomized stopping. Furthermore, for some geometric Lévy processes, the problem has a solution only if randomized stopping is allowed. When randomized stopping is allowed, we give a solution to the variance problem. We identify the Lévy processes for which the allowance of randomized stopping times increases the maximum variance. When it does, we also solve the variance problem without randomized stopping. [ABSTRACT FROM AUTHOR]

The properties of variance ratio tests across trading and non-trading periods are examined using the generalized method of moments. For the case of opening and closing return variances, the joint tests indicate that the null hypothesis that the variance of opening returns equals the variance of closing returns cannot be rejected for a sample of New York Stock Exchange stocks. This example demonstrates the importance of accounting for overlapping observations and cross correlation in such frameworks. The conventional average (across assets) variance ratio test is shown to be biased against the null in small samples. Specifically, when non-zero correlations are ignored, previous tests have the wrong asymptotic size. This bias persists in other frameworks as well: although this study confirms earlier findings that the return variance during non-trading periods is significantly lower than during trading periods, test statistics that ignore correlations are shown to be inflated. [ABSTRACT FROM AUTHOR]

In this paper, we derive simple, directly computable conditions for minimum-variance portfolios to have all positive weights. We show that either there is no minimum- variance portfolio with all positive weights or there is a single segment of the minimum-variance frontier for which all portfolios have positive weights. Then, we examine the likelihood of observing positively weighted minimum-variance portfolios. Analytical and computational results suggest that: i) even if the mean vector and covariance matrix are compatible with a given positively weighted portfolio being mean-variance efficient, the proportion of the minimum-variance frontier containing positively weighted portfolios is small and decreases as the number of assets in the universe increases, and ii) small perturbations in the means will likely lead to no positively weighted minimum-variance portfolios. [ABSTRACT FROM AUTHOR]

A spot portfolio of rate-sensitive assets can be hedged by a portfolio of interest-sensitive futures contracts. The hedge ratios of minimum-variance portfolios are unique when the fixed cash flows of underlying instruments are linearly independent and when the covariance matrix of unexpected changes in spot rates over the term of the cash flows is of full rank. Hilliard's (1984) full-rank model has produced smaller portfolio variances than a duration model in a short-term hedging context. However, the methodology typically requires extensive econometric analysis. This paper develops a structured covariance matrix of full rank that requires only one parameter estimate. Hedging examples are provided. [ABSTRACT FROM AUTHOR]

In this paper, we examine the pricing of European call options on stocks that have variance rates that change randomly. We study continuous time diffusion processes for the stock return and the standard deviation parameter, and we find that one must use the stock and two options to form a riskless hedge. The riskless hedge does not lead to a unique option pricing function because the random standard deviation is not a traded security. One must appeal to an equilibrium asset pricing model to derive a unique option pricing function. In general, the option price depends on the risk premium associated with the random standard deviation. We find that the problem can be simplified by assuming that volatility risk can be diversified away and that changes in volatility are uncorrelated with the stock return. The resulting solution is an integral of the Black-Scholes formula and the distribution function for the variance of the stock price. We show that accurate option prices can be computed via Monte Carlo simulations and we apply the model to a set of actual prices. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to show that, when Φ[sub V]/Φ[sub E] is assumed to be constant, the mean-variance model is consistent with the expected-utility principle if and only if the utility function and the distribution of asset values are of specific forms: namely, negative exponential and normal. The result is stated formally and proved in Section II. Its significance is discussed in the final section. [ABSTRACT FROM AUTHOR]

The promotion of choice and control for older people is a policy priority for social care services in the United Kingdom and is at the heart of recent drives to personalise services. Increasingly, we are seeing a move away from institutionalised care (e.g. in care homes) towards enablement, with more services being delivered in community-based settings. Extra care housing has been promoted as a purpose-built, community-based alternative to residential care for older people. However, whilst accounts of users' experiences in particular service types are plentiful, the use of different instrumentation and measures makes comparison between settings difficult. We combined data from four studies where participants were older people either living in care homes or extra care housing or receiving care at home. All of these studies asked participants to rate their control over daily life, using the Adult Social Care Outcomes Toolkit (ASCOT). This paper presents the results of an ordinal logistic regression analysis indicating that, after controlling for differences in age, ability to perform activities of daily living and self-rated health, setting had a significant effect on older people's sense of control. Residents in care homes and extra care housing report similar levels of control over daily life but consistently report feeling more in control than older people receiving care at home. Implications for policy and practice are discussed. [ABSTRACT FROM PUBLISHER]

The article presents an examination into the shortcomings of the mean-variance approach to portfolio selection modeling, wherein the simultaneous estimation error problem is not accounted for. A particular scenario is presented where the estimation error becomes so large it invalidates the utility of the mean-variance approach. Implications and further questions on the model's inadequacies are also provided.