Parameter estimation of complex mixed models based on meta-model approach

Complex biological processes are usually experimented along time among a collection of individuals, longitudinal data are then available. The statistical challenge is to better understand the underlying biological mechanisms. A standard statistical approach is mixed-effects model where the regression function is highly-developed to describe precisely the biological processes (solutions of multi-dimensional ordinary differential equations or of partial differential equation). A classical estimation method relies on coupling a stochastic version of the EM algorithm with a Monte Carlo Markov Chain algorithm. This algorithm requires many evaluations of the regression function. This is clearly prohibitive when the solution is numerically approximated with a time-consuming solver. In this paper a meta-model relying on a Gaussian process emulator is proposed to approximate the regression function, that leads to what is called a mixed meta-model. The uncertainty of the meta-model approximation can be incorporated in the model. A control on the distance between the maximum likelihood estimates of the mixed meta-model and the maximum likelihood estimates of the exact mixed model is guaranteed. Eventually, numerical simulations are performed to illustrate the efficiency of this approach.     

A Cross‐Cultural Study of Adolescent Procrastination

In this study, we explore academic procrastination and associated motivation variables in 612 adolescents from Canada and Singapore. Few studies have explored adolescent procrastination and no previous studies have investigated adolescent procrastination using a cross‐cultural framework. Singaporean adolescents reported higher levels of procrastination and lower levels of self‐efficacy for self‐regulation than Canadian adolescents. Males across settings reported higher levels of procrastination and lower levels of self‐efficacy for self‐regulation than females. Bivariate relationships between procrastination and the motivation variables showed similar patterns in Singapore and Canada. Multigroup structural equation modeling revealed that self‐efficacy for self‐regulation showed the strongest multivariate relationship with procrastination for adolescents in both settings. The article concludes with implications for practitioners and researchers.     

Fall incidence in a state psychiatric hospital in Singapore

The results of a retrospective study of fall incidence during a 1-year period in a psychiatric hospital in Singapore are reported, involving 309 patients who fell one or more times during their stay. The profile of inpatients involved in falls was identified. Data were derived from standard incident forms completed whenever patients had a fall. A total of 348 falls were identified for the 1-year period. Results revealed higher fall rates in younger male epileptic patients; elderly female patients, age 70 and older with depression or dementia; individuals with concomitant medical conditions; and patients taking three types of medication. The majority of falls occurred when the activity level was high in the ward. Young epileptic patients and elderly depressed patients were prone to repeated falls. These results have the potential to assist in identifying patients at high risk and in designing and implementing strategies to prevent such incidents.     

Mental health literacy beliefs. A comparison of psychiatric trained nurses and enrolled nurses in Singapore

The views of mental health professionals may influence diagnosis and management options. This study reports nurses' views about the management of three common psychiatric disorders--schizophrenia, depression, and mania. Results demonstrate the effect of greater psychiatric education and training, received by psychiatric trained nurses, on mental health literacy.     

Does Prior Banking Experience Matter? Differences of the Banked and Unbanked in Individual Development Accounts

Using data from the 4-year American Dream Demonstration, this study compares saving performance and program participation of banked (n = 1,538) and unbanked participants (n = 466) enrolled in 14 IDA programs. The study shows banked participants had $2.74 higher average monthly net deposit (p < 0.05); 5% higher deposit frequency (p < 0.001); and 42% less odds of drop out than unbanked participants (p < 0.001). Moreover, program characteristics such as financial education, monthly saving targets, peer group meetings, and direct deposit are important predictors of program performances. Individual characteristics such as race/ethnicity, home ownership, and income are significantly associated with program performance.     

Organizational responsiveness of Russian and American growth-oriented small and medium enterprises (SMEs)

The paper discusses problem-based learning (PBL) as a mediating factor in generating a variety of learning networks in workplace contexts. It is argued that informal learning in experiential circumstances can be systematized to encourage deep learning at the individual and collective level. Given the distinct problem-solving opportunities in PBL, learners can increase their capacity to acquire new knowledge through self-inquiry, reflection and dialogue. The repositioning of learning attitudes also leads to an enlargement of communities of practice wherein double and triple-loop learning cycles intersect to create rigorous learning. An integrated model is proposed to explain the dynamics of PBL operating within the constraints of workplace contexts.     

Bonding and attachment of Australian Aboriginal children

In New South Wales, Australia, there is an increasing emphasis in the children's court on bonding and attachment assessments to determine whether or not a child remains with their carers. Aboriginal children and young people are over nine times more likely than other children and young people to be in out‐of‐home care. There is a paucity of information on culturally appropriate assessments of Aboriginal children in relation to bonding and attachment. Most assessments on the Australian indigenous families are based on the dominant Australian community's perception of what constitutes competent parenting. The question arises as to whether we are making psychologically and ethically sound decisions about whether or not a child remains with their Aboriginal carers based on evidence that is culturally appropriate for Western families but culturally inappropriate for the indigenous families. It is argued that the core hypotheses of attachment theory such as caregiver sensitivity, competence and secure base have to be based on the Australian Aboriginal people's cultural values. The aims of this paper are to explore the current practice on the bonding and attachment assessment of Aboriginal children using a dynamic eco‐systemic approach in the assessment of bonding and attachment of the indigenous people, with an emphasis on the historical, cultural and spiritual contexts. Copyright © 2003 John Wiley & Sons, Ltd.     

Coping with Negative Emotions from Buying Mobile Phones: A Study of Korean Consumers

Consumers can suffer negative emotions, such as anger or fear, if they experience difficulties when buying mobile phones, but then they employ coping strategies to manage those emotions. In addition, cognitive appraisals about the purchase situation affect the negative emotions and coping process. This study constructed a structural model and conducted a mail survey involving 1,000 Korean adults. It was discovered that consumers who felt angry chose expressive support-seeking strategies or avoidance, and those who felt fearful chose only expressive support-seeking strategies. Expressive support-seeking and active coping led to positive emotional change. Self-efficacy appraisal was the key predictor of active coping and negatively affected fear; thus, we suggest that consumer education and training in the purchase of new mobile phones is needed to enhance self-efficacy.     

Evaluation of the statistical power for multiple tests: a case study

It is challenging to estimate the statistical power when a complicated testing strategy is used to adjust for the type-I error for multiple comparisons in a clinical trial. In this paper, we use the Bonferroni Inequality to estimate the lower bound of the statistical power assuming that test statistics are approximately normally distributed and the correlation structure among test statistics is unknown or only partially known. The method was applied to the design of a clinical study for sample size and statistical power estimation.     

Adding value to organizations: An examination of the role of senior public relations practitioners in Singapore

A key characteristic of public relations excellence in organizations is ensuring that the senior public relations practitioner – the head of the communication function – has the competencies to enact the strategic role of a manager. It is only when the top communicator possesses strategic management knowledge and engages in managerial work with support from colleagues who are technically skilled in traditional craft work can public relations work be considered to be value-generating.This paper presents the findings of the examination of the role of senior public relations practitioners in organizations in Singapore. It also explores the importance of core communication activities to the role of top in-house communicators, examines the time they allocate to managerial and technical work, and assesses if the managerial role which the practitioners play adds value to organizations. Data collected from both in-depth interviews and self-reported log of daily activities showed that although top communicators in Singapore enjoy strategic reporting and unhindered access to senior management, it also revealed, paradoxically, senior management's mixed worldviews of public relations; and that Singapore's top in-house practitioners lack the strategic knowledge to enact the managerial role as they are too focused on technical work.The paper concludes with recommendations on how the level of public relations professionalism can be raised in Singapore, starting with the practitioners themselves having to be fully equipped with the relevant academic knowledge of what makes communication excellent.