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The Monte Carlo method is used to solve for the price of a call when the variance is changing stochastically. [ABSTRACT FROM AUTHOR]

To date, a number of studies involving the use of bond prices and/or returns have utilized the published prices of trades on the New York and other exchanges. These exchange quotes reflect the odd-lot activities of individual investors and account for only a negligible portion of the trading in listed issues. In contrast, the vast majority of listed corporate trading occurs over-the-counter and involves round-lot trades between institutions. Given differences in market characteristics, odd-lot exchange prices may differ substantially from those in the round-lot institutional market. This study compares exchange quotations from Moody's Bond Record with prices assigned by Merrill Lynch's institutional pricing service and uses each set of prices to calculate return and risk measures. Institutional (Merrill Lynch) bond prices are shown to be systematically greater than exchange (Moody's) prices. In addition, bond returns based on Merrill Lynch prices are shown to yield significantly higher beta and R² estimates, as well as significantly lower standard deviation and residual risk estimates. [ABSTRACT FROM AUTHOR]

The article discusses shelf registration of securities allowed by the United States Securities and Exchange Commission's (SEC) Rule 415 that went into effect in March 1982. The regulation allows firms to register securities they plan to issue within the next two years and then sell the securities when market conditions seem to be best suited for such actions. The rule offers increased flexibility in the way issues are underwritten. The study applies a multiple regression analysis to historic data to see if Rule 415 benefits firms by lessening the interest costs of debt.

Using a technique based upon the behavior of the sample standard deviation as the sample size increases, we have rejected the hypothesis that security return distributions have an infinite variance. Our findings indicate that while the variance of return is finite, it changes over time in a complex fashion. This finding has important implications for future research in finance, both empirical and theoretical. Specifically, the need for a better understanding of those factors which influence return variability is clear. Further, statistical techniques used in conjunction with security returns must be robust with respect to parameter shifts. [ABSTRACT FROM AUTHOR]

The article presents an exploration into the empirical relationships between the alternative portfolio risk evaluation and selection models of mean-lower partial moment and mean-variance sub-forms of the capital asset pricing model (CAPM). Results are given, with moderating considerations outlining the assumptions of underlying positive or negative distribution skewness of returns, highlighting scenarios of significant differences between the two in their variance slope and intercept calculations.

The article reports on the virtues of parameter preference models in portfolio choice. Parameter preference models have empirical content and mean variance (MV) versions which are used in applied models of financial theory. MV efficiency is the optimal strategy for when asset prices follow a diffusion process and portfolios are continuously rebalanced, as is the capital asset pricing model (CAPM). There are some negative test results in the CAPM, or skewness of returns, which are demonstrated due to the empirical content of the tests.

The article discusses the coefficient variation (CV) in investment returns. The mean-coefficient of variation (MCV) efficiency criterion is presented as an alternative to the mean-standard deviation (MSD) definition of efficiency. The differences in MCV and MSD definitions of efficiency are examined in this article on the basis of investors' risk preferences. Corporate decision makers, though they do not know the range of risk aversion coefficients for stockholders, they assume there is a finite range and this enables MCV to evaluate alternative risky ventures.

This article focuses on estimating the optimal stochastic dominance efficient set. The purpose of this research was to investigate empirically the second-degree stochastic dominance (SSD) and third degree stochastic dominance (TSD) efficient sets by mean-semivariance (ESh). To meet this objective the theoretical relationships between SD and ESh developed by R.B. Porter and V.S. Bawa were used. This study examines the relationship between the ESh and SD efficient sets and provides information for developing a SD optimal search algorithm.

This article presents a discussion of heteroscedasticity in the market model. The researchers seek to resolve any contradictions from past studies on heteroscedasticity, identify the incidence of heteroscedasticity in securities, and discuss the implications of heteroscedasticity in a market model. The researchers used a procedure that allowed them to study both the impact of several of the statistical tests and the time period selected on the reported heteroscedasticity incidence. That researchers discuss the limitations on the scope of their study.

This article presents an equilibrium analysis of the capital asset pricing model. The research seeks to approach the capital asset pricing model in a way that is consistent with how general equilibrium theory is usually treated. The properties of the model are determined, including the structure of asset prices and comparative statistics, through a study of the aggregate excess demand functions. By means of the capital asset pricing model the researchers provide conditions for determining equilibrium prices. They then undertake a comparative static analysis.

The article discusses investor portfolio management that accounts for risk-expected return characteristics. The author presents a comparison of the semivariance capital market model to the variance capital market model. The author explains that using semivariance provides a vehicle to measure portfolio risk for those rates of return that fall below the target rate. Further, the author argues, using semivariance answers the needs of the portfolio manager's intuitive notion of risk as a failure to reach a minimum target.

The article discusses common stock return distributions during homogenous activity periods, questioning the authenticity of previous research suggesting return generation processes to be Paretian and non-Gaussian in nature. Empirical research is presented evaluating common stock return behavior, particularly regarding its adherence to normal distribution patterns. Conclusions suggest that the capital asset pricing model remains an unbiased measure of distribution behaviors.

The purpose of this study was to test empirically the risk and return relationships for a mean-variance (E-V) and a mean-semivariance (E-S) capital asset pricing model (CAPM). To date, virtually all empirical work has focused on the Sharpe-Lintner [28,17] E-V model. In the E-V model, the risk of an efficient portfolio is measured by the standard deviation of return, σ[sub p]. For individual securities, the appropriate measure of risk is the covariance of return on the security and the market portfolio. The E-V model states that the expected return of any security or portfolio equals the risk-free rate of return plus a risk premium that is beta;times the difference between the expected return on the market portfolio and the risk-free rate of return, i.e., (1) E(&Rtilde;[sub i]) = R[sub f] + [E(&Rtilde;[sub m]) - R[sub f]1β[sub i] where the tildes denote random variables, and E(&Rtilde;[sub i]) = expected rate of return on security i, R[sub f] = risk-free rate of return, E (&Rtilde;[sub m]) = expected rate of return on the market portfolio, and β = Cov(&Rtilde;[sub i], &Rtilde;[sub m)/σ²(&Rtilde;[sub m]). [ABSTRACT FROM AUTHOR]

The article focuses on extending Hogan and Warren's mean-semivariance model to a capital budgeting decision rule. The authors also seek to compare the parallel developments the mean-variance (EV) model and the mean-semivariance (ES) model. The article provides illustrations for the EV and ES models, as well as a discussion on extending the E-S model with the expression for the expected return of an individual asset.

This article presents an examination of exchange-rate flexibility and the efficiency of the foreign-exchange markets. The article takes the approach of substantial flexibility. Substantial flexibility may yield greater results compared to a direct comparison of transaction costs under different exchange-rate regimes because a direct comparison may be invalidated by differences in underlying economic conditions. Commented on is the cost of using the foreign-exchange markets, hypothesis regarding variation in markups, and tests of the hypothesis.

Despite the enormous attention received by the single-period mean-variance model in the literature, its structural relationship to the empirical world is still largely unexplored. The purpose of this note is to show that when certain consistency requirements and equilibrium conditions in the financial markets are taken into account, the collective judgment of the present literature concerning the mean-variance approach is in some respects too lenient and in other respects too harsh. In addition, it will be noted that the mean-variance model can only achieve consistency with the von Neumann-Morgenstern postulates and absolute preference (also known as first-order stochastic dominance) at the price of a severe upper bound on the risk aversion that can be possessed by the decision maker. [ABSTRACT FROM AUTHOR]

This article presents an analytic derivation of the efficient portfolio frontier. The author explicitly derives the efficient portfolio frontiers and verifies the characteristics of these frontiers. The author states that the most significant implication that results from the verification of these characteristics is the separation theorem and that this theorem is stated and proved in the context of the mutual fund theorem. As a result of this finding, the author argues that the classical graph technique for deriving the efficient portfolio frontier is incorrect.

This article presents information on the computation of the efficient boundary in the E-S portfolio selection model. The authors note that this method for managing a portfolio has yet to be studied in-depth and attempt to bring together what empirical evidence has been gathered in an effort to remove the computational barrier that remains. They show that the model has levels of validity comparable to other portfolio selection models and while it may be more complex that others, it is has efficient computation schemes.

The analysis of efficient portfolio selection, by economist Harry Markowitz, which can be interpreted as solving the quadratic-programming problem of minimizing the variance of a normal variate subject to each prescribed mean value, easily can be generalized to the concave-programming problem of minimizing the "dispersion" of a stable Pareto-Levy variate subject to each prescribed mean value. The Pareto-Levy functions are interesting because they have the stable reproduction property. This of course includes the familiar property of the normal distribution as the special case where it can be interpreted as the standard or root-mean-square deviation. Let an investor begin with initial money wealth, W, which by conventional choice of units can be set equal to unity. One can allocate it among investments at constant returns-to-scale, so that each dollar invested in X brings the same return as any other dollar.

Objective: To assess produce availability, quality and price in a large sample of food stores in low-income neighbourhoods in California.Design: Cross-sectional statewide survey.Setting: Between 2011 and 2015, local health departments assessed store type, WIC (Supplemental Nutrition Program for Women, Infants, and Children)/SNAP (Supplemental Nutrition Assistance Program) participation, produce availability, quality and price of selected items in stores in low-income neighbourhoods. Secondary data provided reference chain supermarket produce prices matched by county and month. t Tests and ANOVA examined differences by store type; regression models examined factors associated with price.Subjects: Large grocery stores (n 231), small markets (n 621) and convenience stores (n 622) in 225 neighbourhoods.Results: Produce in most large groceries was rated high quality (97 % of fruits, 98 % of vegetables), but not in convenience stores (25 % fruits, 14 % vegetables). Small markets and convenience stores participating in WIC and/or SNAP had better produce availability, variety and quality than non-participating stores. Produce prices across store types were, on average, higher than reference prices from matched chain supermarkets (27 % higher in large groceries, 37 % higher in small markets, 102 % higher in convenience stores). Price was significantly inversely associated with produce variety, adjusting for quality, store type, and SNAP and WIC participation.Conclusions: The study finds that fresh produce is more expensive in low-income neighbourhoods and that convenience stores offer more expensive, poorer-quality produce than other stores. Variety is associated with price and most limited in convenience stores, suggesting more work is needed to determine how convenience stores can provide low-income consumers with access to affordable, high-quality produce. WIC and SNAP can contribute to the solution. [ABSTRACT FROM AUTHOR]

ABSTRACTObjective:Little is known about the associations between family satisfaction with end-of-life care and caregiver burden. We conducted a researcher-assisted questionnaire survey to clarify the impact of caregiver burden on family satisfaction and to determine the types of burden that decrease family satisfaction.Method: Bereaved family caregivers of patients with advanced cancer who received our outreach palliative care service were retrospectively identified. Family satisfaction with the end-of-life care provided by the palliative care service and caregiver burden were quantified using the Japanese versions of the FAMCARE Scale and the Zarit Burden Interview (ZBI), respectively.Results: Our study subjects included 23 family caregivers. The mean scores on the FAMCARE Scale and the ZBI for the total population were 72.8 ± 11.2 and 22.8 ± 17.3, respectively, indicating moderate-to-high satisfaction and low-to-moderate burden. Caregiver burden had a strong negative correlation to family satisfaction with end-of-life care (Spearman's rho [ρ] = -0.560, p = 0.005), which remained after adjustment for potential confounders (standardized beta [β] = -0.563, p = 0.01). Several burden items-including loss of control, personal time, social engagement with others, feeling angry with the patient, feeling that the patient wants more help than he/she needs, and a wish to leave the care to someone else-were associated with decreased satisfaction. The major cause of dissatisfaction for family members included the information provided regarding prognosis, family conferences with medical professionals, and the method of involvement of family members in care decisions.Significance Of Results: Caregiver burden can be a barrier to family satisfaction with end-of-life care at home. A home care model focused on caregiver burden could improve end-of-life experiences for patients and family caregivers. [ABSTRACT FROM AUTHOR]

Background: Evidence suggests that autism and schizophrenia share similarities in genetic, neuropsychological and behavioural aspects. Although both disorders are associated with theory of mind (ToM) impairments, a few studies have directly compared ToM between autism patients and schizophrenia patients. This study aimed to investigate to what extent high-functioning autism patients and schizophrenia patients share and differ in ToM performance. Methods: Thirty high-functioning autism patients, 30 schizophrenia patients and 30 healthy individuals were recruited. Participants were matched in age, gender and estimated intelligence quotient. The verbal-based Faux Pas Task and the visual-based Yoni Task were utilised to examine first- and higher-order, affective and cognitive ToM. The task/item difficulty of two paradigms was examined using mixed model analyses of variance (ANOVAs). Multiple ANOVAs and mixed model ANOVAs were used to examine group differences in ToM. Results: The Faux Pas Task was more difficult than the Yoni Task. High-functioning autism patients showed more severely impaired verbal-based ToM in the Faux Pas Task, but shared similar visual-based ToM impairments in the Yoni Task with schizophrenia patients. Conclusions: The findings that individuals with high-functioning autism shared similar but more severe impairments in verbal ToM than individuals with schizophrenia support the autism–schizophrenia continuum. The finding that verbal-based but not visual-based ToM was more impaired in high-functioning autism patients than schizophrenia patients could be attributable to the varied task/item difficulty between the two paradigms. [ABSTRACT FROM AUTHOR]

In the context of 90 adult Japanese learners of English with diverse second language experience and 10 native speakers, this study examined the linguistic characteristics and learner profiles of low-, mid- and high-level fluency performance. The participants' spontaneous speech samples were initially rated by 10 native listeners for global fluency on a 9-point scale (1 = dysfluent , 9 = very fluent), and then divided into four proficiency groups via cluster analyses: low (n = 29), mid (n = 30), high (n = 31), and native (n = 10). Next, the data set was analyzed for the number of pauses within/between clauses, articulation rate, and the frequency of repetitions/self-corrections. According to the results of a series of analyses of variance, the frequency of final-clause pauses differentiated low- and mid-level fluency performance; the number of mid-clause pauses differentiated mid- and high-level performance; and articulation rate differentiated high-level and nativelike performance. The analyses also found that the participants' second language fluency was significantly associated with their length of residence profiles (0–18 years), but not with their age of arrival profiles (19–40 years). [ABSTRACT FROM AUTHOR]

This study was a randomised, double-blind, placebo-controlled cross-over trial examining the effects of β-hydroxy β-methylbutyrate free acid (HMB-FA) supplementation on muscle protein breakdown, cortisol, testosterone and resting energy expenditure (REE) during acute fasting. Conditions consisted of supplementation with 3 g/d HMB-FA or placebo during a 3-d meat-free diet followed by a 24-h fast. Urine was collected before and during the 24-h fast for analysis of 3-methylhistidine:creatinine ratio (3MH:CR). Salivary cortisol, testosterone, their ratio (T:C), and the cortisol awakening response were assessed. ANOVA was used to analyse all dependent variables, and linear mixed models were used to confirm the absence of carryover effects. Eleven participants (six females, five males) completed the study. Urinary HMB concentrations confirmed compliance with supplementation. 3MH:CR was unaffected by fasting and supplementation, but the cortisol awakening response differed between conditions. In both conditions, cortisol increased from awakening to 30 min post-awakening (P=0·01). Cortisol was reduced from 30 to 45 min post-awakening with HMB-FA ( − 32 %, d= − 1·0, P=0·04), but not placebo (PL) ( − 6 %, d= − 0·2, P=0·14). In males, T:C increased from 0 to 24 h of fasting with HMB-FA (+162 %, d=3·0, P=0·001), but not placebo (+13 %, d=0·4, P=0·60), due to reductions in cortisol. REE was higher at 24 h of fasting than 16 h of fasting independent of supplementation (+4·0 %, d=0·3, P=0·04). In conclusion, HMB-FA may affect cortisol responses, but not myofibrillar proteolysis, during acute 24-h fasting. [ABSTRACT FROM AUTHOR]

In this systematic review and meta-analysis of observational studies, we aimed to estimate the associations between prenatal vitamin D status and offspring growth, adiposity and metabolic health. We searched the literature in human studies on prenatal vitamin D status and offspring growth in PubMed, up to July 2017. Studies were selected according to their methodological quality and outcomes of interest (anthropometry, fat mass and diabetes in offspring). The inverse variance method was used to calculate the pooled mean difference (MD) with 95% CI for continuous outcomes, and the Mantel-Haenszel method was used to calculate the pooled OR with 95% CI for dichotomous outcomes. In all, thirty observational studies involving 35 032 mother-offspring pairs were included. Vitamin D status was evaluated by circulating 25-hydroxyvitamin D (25(OH)D) level. Low vitamin D status was based on each study's cut-off for low 25(OH)D levels. Low prenatal vitamin D levels were associated with lower birth weight (g) (MD -100·69; 95% CI -162·25, -39·13), increased risk of small-for-gestational-age (OR 1·55; 95% CI 1·16, 2·07) and an elevated weight (g) in infant at the age of 9 months (g) (MD 119·75; 95% CI 32·97, 206·52). No associations were observed between prenatal vitamin D status and other growth parameters at birth, age 1 year, 4-6 years or 9 years, nor with diabetes type 1. Prenatal vitamin D may play a role in infant adiposity and accelerated postnatal growth. The effects of prenatal vitamin D on long-term metabolic health outcomes in children warrant future studies. [ABSTRACT FROM AUTHOR]

This study examined the personal factors as measured by the Vocational Rehabilitation Index and their influence on returning to work after compensable occupational injuries. The participants comprised 462 patients (335 males; 127 females) who underwent a vocational assessment. The length of time since the injury occurred varied from less than 1 year to 15 years with a mean of 3 years (SD = 2). Results indicated that only 23% had returned to work. Just on 30% of the patients had not worked at all since the accident and some 48% had returned to work but were now not working. The major influences on return to work following an occupational injury that were statistically significant (p < 0.001) were (a) the length of treatment (i.e., time since the injury), and (b) whether there was a psychological problem. The findings support the validity of the Vocational Rehabilitation Index for predicting the probability of return to work following an accident. [ABSTRACT FROM PUBLISHER]

BackgroundEarly trauma is linked to higher symptom levels in bipolar and psychotic disorders, but the translating mechanisms are not well understood. This study examines whether the relationship between early emotional abuse and depressive symptoms is mediated by metacognitive beliefs about thoughts being uncontrollable/dangerous, and whether this pathway extends to influence positive symptoms.MethodPatients (N = 261) with psychotic or bipolar disorders were assessed for early trauma experiences, metacognitive beliefs, and current depression/anxiety and positive symptoms. Mediation path analyses using ordinary least-squares regressions tested if the effect of early emotional abuse on depression/anxiety was mediated by metacognitive beliefs, and if the effect of early emotional abuse on positive symptoms was mediated by metacognitive beliefs and depression/anxiety.ResultsMetacognitive beliefs about thoughts being uncontrollable/dangerous significantly mediated the relationship between early emotional abuse and depression/anxiety. Metacognitive beliefs and depression/anxiety significantly mediated the relationship between early emotional abuse and positive symptoms. The models explained a moderate amount of the variance in symptoms (R2 = 0.21–0.29).ConclusionOur results indicate that early emotional abuse is relevant to depression/anxiety and positive symptoms in bipolar and psychotic disorders, and suggest that metacognitive beliefs could play a role in an affective pathway to psychosis. Metacognitive beliefs could be relevant treatment targets with regards to depression/anxiety and positive symptoms in bipolar and psychotic disorders. [ABSTRACT FROM PUBLISHER]

It is not known if breakfast consumption is an effective intervention for altering daily energy balance in adolescents when compared with breakfast omission. This study examined the acute effect of breakfast consumption and omission on free-living energy intake (EI) and physical activity (PA) in adolescent girls. Using an acute randomised cross-over design, forty girls (age 13⋅3 (SD 0⋅8) years, BMI 21⋅5 (SD 5⋅0) kg/m ²) completed two, 3-d conditions in a randomised, counter-balanced order: no breakfast (NB) and standardised (approximately 1962 kJ) breakfast (SB). Dietary intakes were assessed using food diaries combined with digital photographic records and PA was measured via accelerometry throughout each condition. Statistical analyses were completed using repeated-measures ANOVA. Post-breakfast EI was 483 (SD 1309) kJ/d higher in NB v. SB (P =0⋅025), but total daily EI was 1479 (SD 11311) kJ/d higher in SB v. NB (P<0⋅0005). Daily carbohydrate, fibre and protein intakes were higher in SB v. NB (P<0⋅0005), whereas daily fat intake was not different (P=0⋅405). Effect sizes met the minimum important difference of ≥0⋅20 for all significant effects. Breakfast manipulation did not affect post-breakfast macronutrient intakes (P ≥0⋅451) or time spent sedentary or in PA (P≥0⋅657). In this sample of adolescent girls, breakfast omission increased post-breakfast free-living EI, but total daily EI was greater when a SB was consumed. We found no evidence that breakfast consumption induces compensatory changes in PA. Further experimental research is required to determine the effects of extended periods of breakfast manipulation in young people. [ABSTRACT FROM AUTHOR]

Second language (L2) research relies heavily and increasingly on ANOVA (analysis of variance)-based results as a means to advance theory and practice. This fact alone should merit some reflection on the utility and value of ANOVA. It is possible that we could use this procedure more appropriately and, as argued here, other analyses such as multiple regression may prove to be more illuminating in certain research contexts. We begin this article with an overview of problems associated with ANOVA; some of them are inherent to the procedure, and others are tied to the way it is applied in L2 research. We then present three rationales for when researchers might turn to multiple regression in place of ANOVA. Output from ANOVA and multiple regression analyses based on published and mock-up studies are used to illustrate major points. [ABSTRACT FROM PUBLISHER]

Taylor's law (TL) originated as an empirical pattern in ecology. In many sets of samples of population density, the variance of each sample was approximately proportional to a power of the mean of that sample. In a family of nonnegative random variables, TL asserts that the population variance is proportional to a power of the population mean. TL, sometimes called fluctuation scaling, holds widely in physics, ecology, finance, demography, epidemiology, and other sciences, and characterizes many classical probability distributions and stochastic processes such as branching processes and birth-and-death processes. We demonstrate analytically for the first time that a version of TL holds for a class of distributions with infinite mean. These distributions, a subset of stable laws, and the associated TL differ qualitatively from those of light-tailed distributions. Our results employ and contribute to the methodology of Albrecher and Teugels (2006) and Albrecher et al. (2010). This work opens a new domain of investigation for generalizations of TL. [ABSTRACT FROM PUBLISHER]

BackgroundDSM-5 includes two conceptualizations of personality disorders (PDs). The classification in Section II is identical to the one found in DSM-IV, and includes 10 categorical PDs. The Alternative Model (Section III) includes criteria for dimensional measures of maladaptive personality traits organized into five domains. The degree to which the two conceptualizations reflect the same etiological factors is not known.MethodsWe use data from a large population-based sample of adult twins from the Norwegian Institute of Public Health Twin Panel on interview-based DSM-IV PDs and a short self-report inventory that indexes the five domains of the DSM-5 Alternative Model plus a domain explicitly targeting compulsivity. Schizotypal, Paranoid, Antisocial, Borderline, Avoidant, and Obsessive-compulsive PDs were assessed at the same time as the maladaptive personality traits and 10 years previously. Schizoid, Histrionic, Narcissistic, and Dependent PDs were only assessed at the first interview. Biometric models were used to estimate overlap in genetic and environmental risk factors.ResultsWhen measured concurrently, there was 100% genetic overlap between the maladaptive trait domains and Paranoid, Schizotypal, Antisocial, Borderline, and Avoidant PDs. For OCPD, 43% of the genetic variance was shared with the domains. Genetic correlations between the individual domains and PDs ranged from +0.21 to +0.91.ConclusionThe pathological personality trait domains, which are part of the Alternative Model for classification of PDs in DSM-5 Section III, appears to tap, at an aggregate level, the same genetic risk factors as the DSM-5 Section II classification for most of the PDs. [ABSTRACT FROM PUBLISHER]

The tail index as a measure of tail thickness provides information that is not captured by standard volatility measures. It may however change over time. Currently available procedures for detecting those changes for dependent data (e.g., Quintos et al., 2001) are all based on comparing Hill (1975) estimates from different subsamples. We derive tests for a wide class of other tail index estimators. The limiting distribution of the test statistics is shown not to depend on the particular choice of the estimator, while the assumptions on the dependence structure allow for sufficient generality in applications. A simulation study investigates empirical sizes and powers of the tests in finite samples. [ABSTRACT FROM AUTHOR]

This article reports a study of acoustic phonetic variation between ethnic groups in the realisation of the British English liquids /l/ and /ɹ/. Data are presented from ‘Anglo’ and ‘Asian’ native speakers of Sheffield English. Sheffield Anglo English is typically described as having ‘dark’ /l/, but there is some disagreement in the literature. British Asian speakers, on the other hand, are often described as producing much ‘clearer’ realisations of /l/, but the specific differences between varieties may vary by geographical location. Regression analysis of liquid steady states and Smoothing Spline ANOVAs of vocalic–liquid formant trajectories show consistent F2−F1 differences in /l/ between Anglo and Asian speakers in non-final contexts, which is suggestive of a strong distinction between varieties in terms of clearness/darkness. There is also evidence of a polarity effect in liquids, with differing relationships between liquid phonemes in each variety: Asian speakers produce /l/ with higher F2−F1 values than /ɹ/, and Anglo speakers produce /ɹ/ with higher F2−F1 values than /l/. The results are discussed in terms of phonetic variation in liquids and socioindexical factors in speech production. [ABSTRACT FROM AUTHOR]

We derive nonparametric efficiency bounds for regular estimators of integrated smooth transformations of instantaneous variances, in particular, integrated power variance. We find that realized variance attains the efficiency bound for integrated variance under both regular and irregular sampling schemes. For estimating higher powers such as integrated quarticity, the block-based procedures of Mykland and Zhang (2009) can get arbitrarily close to the nonparametric bounds, when observation times are equidistant. Moreover, the estimator in Jacod and Rosenbaum (2013), whose efficiency was documented for the submodel assuming constant volatility, is efficient also for nonconstant volatility paths. When the observation times are possibly random but predictable, we provide an estimator, similar to that of Kristensen (2010), which can get arbitrarily close to the nonparametric bound. Finally, parametric information about the functional form of volatility leads to a lower efficiency bound, unless the volatility process is piecewise constant. [ABSTRACT FROM AUTHOR]

BackgroundAutism spectrum disorder (ASD) is a highly heritable neurodevelopmental disorder, yet the search for definite genetic etiologies remains elusive. Delineating ASD endophenotypes can boost the statistical power to identify the genetic etiologies and pathophysiology of ASD. We aimed to test for endophenotypes of neuroanatomy and associated intrinsic functional connectivity (iFC) via contrasting male youth with ASD, their unaffected brothers and typically developing (TD) males.MethodThe 94 participants (aged 9–19 years) – 20 male youth with ASD, 20 unaffected brothers and 54 TD males – received clinical assessments, and undertook structural and resting-state functional magnetic resonance imaging scans. Voxel-based morphometry was performed to obtain regional gray and white matter volumes. A seed-based approach, with seeds defined by the regions demonstrating atypical neuroanatomy shared by youth with ASD and unaffected brothers, was implemented to derive iFC. General linear models were used to compare brain structures and iFC among the three groups. Assessment of familiality was investigated by permutation tests for variance of the within-family pair difference.ResultsWe found that atypical gray matter volume in the mid-cingulate cortex was shared between male youth with ASD and their unaffected brothers as compared with TD males. Moreover, reduced iFC between the mid-cingulate cortex and the right inferior frontal gyrus, and increased iFC between the mid-cingulate cortex and bilateral middle occipital gyrus were the shared features of male ASD youth and unaffected brothers.ConclusionsAtypical neuroanatomy and iFC surrounding the mid-cingulate cortex may be a potential endophenotypic marker for ASD in males. [ABSTRACT FROM PUBLISHER]

Objective:To determine the length and position of a thyroidectomy scar that is cosmetically most appealing to naïve raters.Methods:Images of thyroidectomy scars were reproduced on male and female necks using digital imaging software. Surgical variables studied were scar position and length. Fifteen raters were presented with 56 scar pairings and asked to identify which was preferred cosmetically. Twenty duplicate pairings were included to assess rater reliability. Analysis of variance was used to determine preference.Results:Raters preferred low, short scars, followed by high, short scars, with long scars in either position being less desirable (p < 0.05). Twelve of 15 raters had acceptable intra-rater and inter-rater reliability.Conclusion:Naïve raters preferred low, short scars over the alternatives. High, short scars were the next most favourably rated. If other factors influencing incision choice are considered equal, surgeons should consider these preferences in scar position and length when planning their thyroidectomy approach. [ABSTRACT FROM PUBLISHER]

It can be challenging to provide person-centred care for individuals with cognitive impairment if they are unable to communicate their needs to facility providers clearly. The high base rates of dementia and mild cognitive impairment (MCI) in US nursing homes is well documented; however, our understanding of the unique prevalence of cognitive levels in long-term care and short-stay residents is limited. Our aim is to determine whether there are significant differences in specific cognitive levels between these two groups. Long-term care and short-stay residents (N = 579) were randomly selected from 18 Maryland, US skilled nursing facilities; 345 met inclusion criteria for participation (mean age 79.41) and completed a cognitive test (Brief Cognitive Assessment Tool (BCAT)). Based on BCAT scores, 78.9 per cent of the long-term care residents had dementia compared to 61.4 per cent for short-stay residents. The proportions of MCI, mild, and moderate to severe dementia were significantly different between the two groups (p = 0.00). The odds of residents having moderate to severe dementia were 2.76 times greater for long-term care compared to short-stay residents. BCAT total and factor scores were significantly different between long-term care and short-stay nursing home residents (p < 0.001). We discuss the implications of these empirical findings in terms of facilitating person-centred care in nursing homes. [ABSTRACT FROM AUTHOR]

ObjectiveThe specific role of major socio-economic indicators (education, occupation, income) in influencing consumer choice of animal foods (AF) intake could reveal distinct socio-economic facets, thus enabling elucidation of mechanisms leading to social inequalities in health. We investigated the independent association of each indicator with intake of different AF and their effect modification.DesignCross-sectional study. AF intake was estimated using three 24 h dietary records. Associations between socio-economic factors and AF intake and interactions between socio-economic indicators were assessed using ANCOVA adjusted for age and energy intake. Analyses were performed separately for men and women, since gender interactions were found.SettingFrance.SubjectsAdults (n 92 036) participating in the NutriNet-Santé Study.ResultsLow educated persons had higher intake of red meat (+9–12 g/d), processed meat (+6–9 g/d) and poultry (for men, +7 g/d) than those with a higher education level. Percentage of fish consumers was lower in individuals of the lowest income class compared with those in higher classes. Manual workers had a higher intake of cream desserts (for men, +14 g/d) than managerial staff. Few significant interactions were found. In stratified analyses, persons with the highest income consumed more yoghurt than those who had lower income, only in low educated individuals.ConclusionsSocio-economic disparities in AF intake varied according to the socio-economic indicator, suggesting the specific influence of each indicator on AF intake. In particular, lower education was associated with higher intake of red and processed meats and cream desserts, and had an effect modification on the relationship between income and AF intake. [ABSTRACT FROM PUBLISHER]

Mounting evidence showed that bitter-tasting compounds modulate eating behaviour through bitter taste receptors in the gastrointestinal tract. This study aimed at evaluating the influence of microencapsulated bitter compounds on human appetite and energy intakes. A microencapsulated bitter ingredient (EBI) with a core of bitter Gentiana lutea root extract and a coating of ethylcellulose–stearate was developed and included in a vanilla microencapsulated bitter ingredient-enriched pudding (EBIP). The coating masked bitterness in the mouth, allowing the release of bitter secoiridoids in the gastrointestinal tract. A cross-over randomised study was performed: twenty healthy subjects consumed at breakfast EBIP (providing 100 mg of secoiridoids) or the control pudding (CP) on two different occasions. Blood samples, glycaemia and appetite ratings were collected at baseline and 30, 60, 120 and 180 min after breakfast. Gastrointestinal peptides, endocannabinoids (EC) and N-acylethanolamines (NAE) were measured in plasma samples. Energy intakes were measured at an ad libitum lunch 3 h after breakfast and over the rest of the day (post lunch) through food diaries. No significant difference in postprandial plasma responses of gastrointestinal hormones, glucose, EC and NAE and of appetite between EBIP and CP was found. However, a trend for a higher response of glucagon-like peptide-1 after EBIP than after CP was observed. EBIP determined a significant 30 % lower energy intake over the post-lunch period compared with CP. These findings were consistent with the tailored release of bitter-tasting compounds from EBIP along the gastrointestinal tract. This study demonstrated that microencapsulated bitter secoiridoids were effective in reducing daily energy intake in humans. [ABSTRACT FROM PUBLISHER]

Active Ageing is conceptualised to measure the extent to which older people remain actively engaged with life. However, there is no evidence that the concept of Active Ageing is actually associated with the activity levels of older persons. Influences of age, ethnicity and spirituality on Active Ageing are also unexplored. Using the Active Ageing Index (AAI), this study examines whether the level of Active Ageing predicted the actual activity level of 120 Singaporeans of Chinese, Malay and Indians ethnicities, aged 55–64 years old or 65 years and above. Spirituality, measured by the Spirituality Index of Well-Being, was added to the AAI, to see if the predictive power of AAI improved. Hierarchical multiple regression showed that the AAI alone (controlling for age) did not significantly predict the activity level of older persons. The predictive power of the AAI improved significantly with spirituality included. Two-way between-groups Analysis of Variance revealed main effects of age and ethnicity, with higher AAI in those aged 55–64 and in Indian-Singaporeans. These findings suggest that the theoretical construct of Active Ageing needs further examination to identify the domains that distinguish it from chronological age, and support broadening the construct by including spirituality in Active Ageing. [ABSTRACT FROM AUTHOR]

BackgroundRelatively few studies have investigated whether relatives of patients with bipolar disorder show brain functional changes, and these have focused on activation changes. Failure of de-activation during cognitive task performance is also seen in the disorder and may have trait-like characteristics since it has been found in euthymia.MethodA total of 20 euthymic patients with bipolar disorder, 20 of their unaffected siblings and 40 healthy controls underwent functional magnetic resonance imaging during performance of the n-back working memory task. An analysis of variance (ANOVA) was fitted to individual whole-brain maps from each set of patient–relative–matched pair of controls. Clusters of significant difference among the groups were used as regions of interest to compare mean activations/de-activations between them.ResultsA single cluster of significant difference among the three groups was found in the whole-brain ANOVA. This was located in the medial prefrontal cortex, a region of task-related de-activation in the healthy controls. Both the patients and their siblings showed significantly reduced de-activation compared with the healthy controls in this region, but the failure was less marked in the relatives.ConclusionsFailure to de-activate the medial prefrontal cortex in both euthymic bipolar patients and their unaffected siblings adds to evidence for default mode network dysfunction in the disorder, and suggests that it may act as a trait marker. [ABSTRACT FROM PUBLISHER]

The benefits of exercise are well documented, nevertheless, physical activity decreases progressively with age, a trend exacerbated in those who have fallen. An important predictor of exercise behaviour is the extent to which motivation for exercise has been internalised into one's identity, however, we know little about changing health behaviours in older people, with calls for longitudinal studies to aid understanding. Grounded in self-determination theory, the present study explored the role of self-talk in the process of identity change during the initial ten weeks of an exercise referral falls prevention programme. Six participants identified at risk of falling completed weekly measures of their physical activity-related cognition and identity; in-depth interviews were completed at course commencement and ten weeks later. During this initial phase of the behaviour change programme, participants developed stronger physical activity identities, with themes reflecting a transition from a physically impaired and negative self to a more future-orientated, capable and integrated self-identity. Concurrently, autonomy-supportive and competence-reinforcing self-talk significantly increased, with non-significant increases and decreases in controlling and amotivational self-talk, respectively. The data suggest that self-talk may be usefully conceptualised as a process through which social messages are interpreted and internalised to integrate a new behaviour into one's existing self-concept. [ABSTRACT FROM PUBLISHER]

Identification and characterisation of dietary patterns are needed to define public health policies to promote better food behaviours. The aim of this study was to identify the major dietary patterns in the French adult population and to determine their main demographic, socioeconomic, nutritional and environmental characteristics. Dietary patterns were defined from food consumption data collected in the second French national cross-sectional dietary survey (2006-2007). Non-negative-matrix factorisation method, followed by a cluster analysis, was implemented to derive the dietary patterns. Logistic regressions were then used to determine their main demographic and socio-economic characteristics. Finally, nutritional profiles and contaminant exposure levels of dietary patterns were compared using ANOVA. Seven dietary patterns, with specific food consumption behaviours, were identified: 'Small eater', 'Health conscious', 'Mediterranean', 'Sweet and processed', 'Traditional', 'Snacker' and 'Basic consumer'. For instance, the Health-conscious pattern was characterised by a high consumption of low-fat and light products. Individuals belonging to this pattern were likely to be older and to have a better nutritional profile than the overall population, but were more exposed to many contaminants. Conversely, individuals of Snacker pattern were likely to be younger, consumed more highly processed foods, had a nutrient-poor profile but were exposed to a limited number of food contaminants. The study identified main dietary patterns in the French adult population with distinct food behaviours and specific demographic, socio-economic, nutritional and environmental features. Paradoxically, for better dietary patterns, potential health risks cannot be ruled out. Therefore, this study demonstrated the need to conduct a risk-benefit analysis to define efficient public health policies regarding diet. [ABSTRACT FROM AUTHOR]

Background. Research has shown that maternal mental illness can affect mother-infant interactions with implications for infant outcomes. Severe and chronic mental illness (SMI), particularly schizophrenia, is associated with the greatest risk. Schizophrenia is also associated with impairments in attribution of mental states, 'theory of mind' (ToM). Recent attachment research has suggested that maternal mentalizing skills are strongly associated with attachment outcome in infants. To date, no research has explored the relationship between ToM and maternal sensitivity in mothers with SMI using standard tests of ToM. The present study was designed as an exploratory study in order to investigate this. Method. A total of 40 women with SMI in the postpartum period were administered a battery of ToM tasks and general neuropsychological tasks. The women were also filmed in an unstructured play session with their infants, which was coded for maternal sensitivity using the Crittenden CARE-Index. Results. One ToM task, the Frith-Happé Animations, predicted maternal sensitivity across all diagnoses. There was also an effect of diagnosis, with lower sensitivity observed in women with schizophrenia. ToM impairments did not fully explain the effect of diagnosis on sensitivity. Mothers of girls were rated as being more sensitive than mothers of boys. Conclusions. The results suggest that ToM is a significant predictor of maternal sensitivity across all mental health diagnoses, extending the results of studies focusing on healthy populations. Clinical interventions emphasizing the importance of understanding the perspective of the infant may enhance maternal sensitivity. [ABSTRACT FROM AUTHOR]

BackgroundCognitive dysfunction in depression and bipolar disorder (BD) is insufficiently targeted by available treatments. Erythropoietin (EPO) increases neuroplasticity and may improve cognition in mood disorders, but the neuronal mechanisms of these effects are unknown. This functional magnetic resonance imaging (fMRI) study investigated the effects of EPO on neural circuitry activity during working memory (WM) performance.MethodPatients with treatment-resistant major depression, who were moderately depressed, or with BD in partial remission, were randomized to eight weekly infusions of EPO (40 000 IU) (N = 30) or saline (N = 26) in a double-blind, parallel-group design. Patients underwent fMRI, mood ratings and blood tests at baseline and week 14. During fMRI patients performed an n-back WM task.ResultsEPO improved WM accuracy compared with saline (p = 0.045). Whole-brain analyses revealed that EPO increased WM load-related activity in the right superior frontal gyrus (SFG) compared with saline (p = 0.01). There was also enhanced WM load-related deactivation of the left hippocampus in EPO-treated compared to saline-treated patients (p = 0.03). Across the entire sample, baseline to follow-up changes in WM performance correlated positively with changes in WM-related SFG activity and negatively with hippocampal response (r = 0.28–0.30, p < 0.05). The effects of EPO were not associated with changes in mood or red blood cells (p ⩾0.08).ConclusionsThe present findings associate changes in WM-load related activity in the right SFG and left hippocampus with improved executive function in EPO-treated patients. Clinical trial registration: clinicaltrials.gov: NCT00916552. [ABSTRACT FROM AUTHOR]

We study the distribution Ex [exp (-q ʃ t 0 1(a,b)(Xs ) ds);Xt∈dy], where -∞⩽a < b < ∞, and where q, t > 0 and x∈R for a spectrally negative Lévy process X. More precisely, we identify the Laplace transform with respect to t of this measure in terms of the scale functions of the underlying process. Our results are then used to price step options and the particular case of an exponential spectrally negative Lévy jump-diffusion model is discussed. [ABSTRACT FROM AUTHOR]

We consider a class of multi-type particle systems whose structure is similar to that of a contact process and show that additivity is equivalent to the existence of a dual process, extending a result of Harris. We prove a necessary and sufficient condition for the model to preserve positive correlations. We then show that complete convergence on Zd holds for a large subclass of models including the two-stage contact process and a household model, and give examples. [ABSTRACT FROM AUTHOR]

We study the asymptotic behavior of a new particle filter approach for the estimation of hidden Markov models. In particular, we develop an algorithm where the latentstate sequence is segmented into multiple shorter portions, with an estimation technique based upon a separate particle filter in each portion. The partitioning facilitates the use of parallel processing, which reduces the wall-clock computational time. Based upon this approach, we introduce new estimators of the latent states and likelihood which have similar or better variance properties compared to estimators derived from standard particle filters. We show that the likelihood function estimator is unbiased, and show asymptotic normality of the underlying estimators. [ABSTRACT FROM AUTHOR]

Let N and M be positive integers satisfying 1 ≤M ≤N, and let 0 < p0 < p1 < 1. Define a process {Xn}∞ n=0 on Z as follows. At each step, the process jumps either one step to the right or one step to the left, according to the following mechanism. For the first N steps, the process behaves like a random walk that jumps to the right with probability p0 and to the left with probability 1 - p0. At subsequent steps the jump mechanism is defined as follows: if at leastM out of the N most recent jumps were to the right then the probability of jumping to the right is p1; however, if fewer thanM out of the N most recent jumps were to the right then the probability of jumping to the right is p0. We calculate the speed of the process. Then we let N→∞and M/N→ r ∊ [0, 1], and calculate the limiting speed. More generally, we consider the above questions for a random walk with a finite number l of threshold levels, (Mi, pi )l i=1, above the pre-threshold level p0, as well as for one model with l = N such thresholds. [ABSTRACT FROM AUTHOR]

We provide exact computations for the drift of random walks in dependent random environments, including k-dependent and moving average environments. We show how the drift can be characterized and evaluated using Perron-Frobenius theory. Comparing random walks in various dependent environments, we demonstrate that their drifts can exhibit interesting behavior that depends significantly on the dependency structure of the random environment. [ABSTRACT FROM AUTHOR]