Toward a receiver-based theory of knowledge sharing

Managers and researchers alike have sought new ways to address the challenges of sharing dispersed knowledge in modern business environments. Careful consideration by sharers of receivers' knowledge needs and behaviours may improve the effectiveness of organisational knowledge sharing. This research examines how sharers react to their perceptions of receivers' knowledge needs and behaviours when making choices relating to sharing knowledge. The focus of this article is to propose and empirically explore a theoretical framework for a study of the role of the receiver in knowledge sharing - receiver-based theory. Data collected from two case studies highlight a key role played by perceived receiver knowledge needs and behaviours in shaping sharer choices when explicit knowledge is shared. A set of receiver influences on knowledge sharing is provided that highlights key receiver and sharer issues. The paper concludes that companies should develop better ways to connect potential sharers with receivers' real knowledge needs. Further, the findings suggest that sharing on a need-to-know basis hinders change in organisational power structures, and prevents the integration of isolated pockets of knowledge that may yield new value. © 2008, IGI Global.

Bias and precision of measures of survival gain from right-censored data

In cost-effectiveness analyses of drugs or health technologies, estimates of life years saved or quality-adjusted life years saved are required. Randomised controlled trials can provide an estimate of the average treatment effect; for survival data, the treatment effect is the difference in mean survival. However, typically not all patients will have reached the endpoint of interest at the close-out of a trial, making it difficult to estimate the difference in mean survival. In this situation, it is common to report the more readily estimable difference in median survival. Alternative approaches to estimating the mean have also been proposed. We conducted a simulation study to investigate the bias and precision of the three most commonly used sample measures of absolute survival gain - difference in median, restricted mean and extended mean survival - when used as estimates of the true mean difference, under different censoring proportions, while assuming a range of survival patterns, represented by Weibull survival distributions with constant, increasing and decreasing hazards. Our study showed that the three commonly used methods tended to underestimate the true treatment effect; consequently, the incremental cost-effectiveness ratio (ICER) would be overestimated. Of the three methods, the least biased is the extended mean survival, which perhaps should be used as the point estimate of the treatment effect to be inputted into the ICER, while the other two approaches could be used in sensitivity analyses. More work on the trade-offs between simple extrapolation using the exponential distribution and more complicated extrapolation using other methods would be valuable.

The role of parity in gestational weight gain and postpartum weight retention

OBJECTIVES: Parity, excessive gestational weight gain (GWG), and postpartum weight retention (PPWR) have been identified as risk factors for maternal obesity. The aim of this study was to explore whether GWG and PPWR at 6 and 12 months after birth differed for primiparous and multiparous Australian women. METHODS: One hundred thirty-eight Australian women provided weight measures in early to mid pregnancy (M = 16.7 weeks, SD = 2.3), late pregnancy (M = 37.7 weeks, SD = 2.4), 6 months postpartum (M = 6.1 months, SD = 1.4), and 12 months postpartum (M = 12.6 months, SD = 0.7). Height, parity, and demographic information were also collected. Prepregnancy body mass index (BMI), total GWG, incidence of excessive GWG, as well as change in BMI and BMI category from prepregnancy to 6 and 12 months postpartum were computed. Differences between primiparous and multiparous women were compared using analysis of covariance (controlling for age, prepregnancy BMI, and GWG) and χ(2) test of independence. RESULTS: Seventy women (50.7%) were primiparous and 68 women (49.3%) were multiparous. Primiparous women were more likely to retain weight at 12 months postpartum than multiparous women (p = .021; Cohen's d = .24). This difference was not reflected when analyzing change in BMI categories from prepregnancy to the postpartum. CONCLUSIONS: Evidence for the role of parity in PPWR is inconclusive. Future research should consider the temporal development of PPWR in primiparous and multiparous women, leading to tailored care in the postpartum period to help women return to a healthy prepregnancy weight.

Psychosocial factors and excessive gestational weight gain: the effect of parity in an Australian cohort

OBJECTIVES: psychosocial variables can be protective or risk factors for excessive gestational weight gain (GWG). Parity has also been associated with GWG; however, its effect on psychosocial risk factors for GWG is yet to be determined. The aim of this study was to investigate if, and how, psychosocial factors vary in their impact on the GWG of primiparous and multiparous women. DESIGN/PARTICIPANTS: pregnant women were recruited in 2011 via study advertisements placed in hospitals, online, in parenting magazines, and at baby and children's markets, resulting in a sample of 256 women (113 primiparous, 143 multiparous). Participants completed questionnaires at 16-18 weeks' gestation and their pregravid BMI was recorded. Final weight before delivery was measured and used to calculate GWG. FINDINGS: the findings revealed that primiparous women had significantly higher feelings of attractiveness (a facet of body attitude; p=0.01) than multiparous women. Hierarchical regressions revealed that in the overall sample, increased GWG was associated significantly with lower pre-pregnancy BMI (standardised coefficient β=-0.39, p<0.001), higher anxiety symptoms (β=0.25, p=0.004), and reduced self-efficacy to eat a healthy diet (β=-0.20, p=0.02). Although higher GWG was predicted significantly by decreased feelings of strength and fitness for primiparous women (β=-0.25, p=0.04) and higher anxiety was related significantly to greater GWG for multiparous women (β=0.43, p<0.001), statistical comparison of the model across the two groups suggested the magnitude of these effects did not differ across groups (p>0.05). CONCLUSIONS/IMPLICATIONS FOR PRACTICE: the findings suggest that psychosocial screening and interventions by healthcare professionals may help to identify women who are at risk of excessive GWG, and there may be specific psychosocial factors that are more relevant for each parity group.

The influence on population weight gain and obesity of the macronutrient composition and energy density of the food supply

Rates of overweight and obesity have increased dramatically in all regions of the world over the last few decades. Almost all of the world's population now has ubiquitous access to low-cost, but highly-processed, energy-dense, nutrient-poor food products. These changes in the food supply, rather than decreases in physical activity, are most likely the primary driver of population weight gain and obesity. To-date, the majority of prevention efforts focus on personalised approaches targeting individuals. Population-wide food supply interventions addressing sodium and trans fat reduction have proven highly effective and comparable efforts are now required to target obesity. The evidence suggests that strategies focusing upon reducing the energy density and portion size of foods will be more effective than those targeting specific macronutrients. Government leadership, clearly specified targets, accountability and transparency will be the key to achieving the food supply changes required to address the global obesity epidemic.

Nonlinear backstepping controller design for sharing active and reactive power in three-phase grid-connected photovoltaic systems

In this paper, a nonlinear backstepping controller is designed for three-phase grid-connected solar photovoltaic (PV) systems to share active and reactive power. A cascaded control structure is considered for the purpose of sharing appropriate amount of power. In this cascaded control structure, the dc-link voltage controller is designed for balancing the power flow within the system and the current controller is designed to shape the grid current into a pure sinusoidal waveform. In order to balance the power flow, it is always essential to maintain a constant voltage across the dc-link capacitor for which an incremental conductance (IC) method is used in this paper. This approach also ensures the operation of solar PV arrays at the maximum power point (MPP) under rapidly changing atmospheric conditions. The proposed current controller is designed to guarantee the current injection into the grid in such a way that the system operates at a power factor other than unity which is essential for sharing active and reactive power. The performance of the proposed backstepping approach is verified on a three-phase grid-connected PV system under different atmospheric conditions. Simulation results show the effectiveness of the proposed control scheme in terms of achieving desired control objectives.

A path model of psychosocial and health behaviour change predictors of excessive gestational weight gain

This study aimed to evaluate a conceptual model of psychosocial, behaviour change, and behavioural predictors of excessive gestational weight gain (GWG). Background: Excessive GWG can place women and their babies at risk of poor health outcomes, including obesity. Models of psychosocial and behaviour change predictors of excessive GWG have not been extensively explored; understanding the mechanisms leading to excess GWG will provide crucial evidence towards the development of effective interventions. Method: Two hundred and eighty-eight pregnant women (≤18 weeks gestation) were recruited to a prospective study. Demographic, psychosocial, health behaviour change, and behavioural factors were assessed at 17 (Time 1, T1) and 33 weeks (Time 2, T2) gestation. Pre-pregnancy and final pregnancy weight were obtained and women were classified with/without excessive GWG. Logistic regressions refined the list of predictors of excessive GWG; variables with p < .1 were included in a path analysis. Results: Age, family income, T2 depression, T2 pregnancy-specific coping, T1 buttocks dissatisfaction, T2 GWG-specific self-efficacy, T1 dietary readiness, T1 dietary importance, and T1 vegetable intake predicted excessive GWG in the logistic regressions and were included in the path model. The baseline path model demonstrated poor fit. Once statistically and theoretically plausible paths were added, adequate model fit was achieved (χ² = 21.61(9), p < .05; RMSEA = .07; CFI = .93); this revised model explained 19.5% of the variance in excessive GWG. Women with high T1 buttocks dissatisfaction were more likely to exhibit low levels of dietary readiness. Women with low dietary readiness were more likely to have a lower vegetable intake, which predicted excessive GWG. Women with higher T2 depressive symptoms were more likely to report lower GWG self-efficacy and gain excessively. Conclusion: Future behavioural GWG trials should consider combining psychosocial and health behaviour change factors to optimise GWG.

Sharing the load: role equity in the incubation of a monomorphic shorebird, the masked lapwing (Vanellus miles)

Sex roles during incubation vary dramatically in socially monogamous shorebirds. The "incubator conspicuousness" hypothesis posits that, for biparentally incubating and sexually dimorphic birds, the more conspicuous sex should incubate when visually foraging predators are inactive, and in many ecosystems this is at night. Therefore, sexually monomorphic species should share incubation equitably throughout the day and night. We examined incubation patterns in Masked Lapwings Vanellus miles and found that the contribution of the sexes to incubation was equitable. Another measure of incubation behavior, bout duration, was similar between the sexes; male bout durations were slightly shorter than for females. This finding is consistent with the predictions of the incubator conspicuousness hypothesis, although other processes may also explain equitable care.

Autoethnography: introducing 'I' into medical education research

Context: Autoethnography is a methodology that allows clinician-educators to research their own cultures, sharing insights about their own teaching and learning journeys in ways that will resonate with others. There are few examples of autoethnographic research in medical education, and many areas would benefit from this methodology to help improve understanding of, for example, teacher-learner interactions, transitions and interprofessional development. Objectives: We wish to share this methodology so that others may consider it in their own education environments as a viable qualitative research approach to gain new insights and understandings. Methods: This paper introduces autoethnography, discusses important considerations in terms of data collection and analysis, explores ethical aspects of writing about others and considers the benefits and limitations of conducting research that includes self. Results: Autoethnography allows medical educators to increasingly engage in self-reflective narration while analysing their own cultural biographies. It moves beyond simple autobiography through the inclusion of other voices and the analytical examination of the relationships between self and others. Autoethnography has achieved its goal if it results in new insights and improvements in personal teaching practices, and if it promotes broader reflection amongst readers about their own teaching and learning environments. Conclusions: Researchers should consider autoethnography as an important methodology to help advance our understanding of the culture and practices of medical education. Discuss ideas arising from the article at www.mededuc.com discuss. © 2015 John Wiley

Online video recommendation in sharing community

The creation of sharing communities has resulted in the astonishing increasing of digital videos, and their wide applications in the domains such as entertainment, online news broadcasting etc. The improvement of these applications relies on effective solutions for social user access to video data. This fact has driven the recent research interest in social recommendation in shared communities. Although certain effort has been put into video recommendation in shared communities, the contextual information on social users has not been well exploited for effective recommendation. In this paper, we propose an approach based on the content and social information of videos for the recommendation in sharing communities. Specifically, we first exploit a robust video cuboid signature together with the Earth Mover's Distance to capture the content relevance of videos. Then, we propose to identify the social relevance of clips using the set of users belonging to a video. We fuse the content relevance and social relevance to identify the relevant videos for recommendation. Following that, we propose a novel scheme called sub-community-based approximation together with a hash-based optimization for improving the efficiency of our solution. Finally, we propose an algorithm for efficiently maintaining the social updates in dynamic shared communities. The extensive experiments are conducted to prove the high effectiveness and efficiency of our proposed video recommendation approach.

Cost-effective authentic and anonymous data sharing with forward security

Data sharing has never been easier with the advances of cloud computing, and an accurate analysis on the shared data provides an array of benefits to both the society and individuals. Data sharing with a large number of participants must take into account several issues, including efficiency, data integrity and privacy of data owner. Ring signature is a promising candidate to construct an anonymous and authentic data sharing system. It allows a data owner to anonymously authenticate his data which can be put into the cloud for storage or analysis purpose. Yet the costly certificate verification in the traditional public key infrastructure (PKI) setting becomes a bottleneck for this solution to be scalable. Identity-based (ID-based) ring signature, which eliminates the process of certificate verification, can be used instead. In this paper, we further enhance the security of ID-based ring signature by providing forward security: If a secret key of any user has been compromised, all previous generated signatures that include this user still remain valid. This property is especially important to any large scale data sharing system, as it is impossible to ask all data owners to re-authenticate their data even if a secret key of one single user has been compromised. We provide a concrete and efficient instantiation of our scheme, prove its security and provide an implementation to show its practicality.

Forecasting bike sharing demand using fuzzy inference mechanism

Forecasting bike sharing demand is of paramount importance for management of fleet in city level. Rapidly changing demand in this service is due to a number of factors including workday, weekend, holiday and weather condition. These nonlinear dependencies make the prediction a difficult task. This work shows that type-1 and type-2 fuzzy inference-based prediction mechanisms can capture this highly variable trend with good accuracy. Wang-Mendel rule generation method is utilized to generate rule base and then only current information like date related information and weather condition is used to forecast bike share demand at any given point in future. Simulation results reveal that fuzzy inference predictors can potentially outperform traditional feed forward neural network in terms of prediction accuracy.

Nutritional intervention to prevent weight gain in patients commenced on olanzapine: a randomized controlled trial

Objective: Olanzapine is the most commonly prescribed atypical antipsychotic medication in Australia. Research reports an average weight gain of between 4.5 and 7 kg in the 3 months following its commencement. Trying to minimize this weight gain in a population with an already high prevalence of obesity, mortality and morbidity is of clinical and social importance. This randomized controlled trial investigated the impact of individual nutrition education provided by a dietitian on weight gain in the 3 and 6 months following the commencement of olanzapine.


Method: Fifty-one individuals (29 females, 22 males) who had started on olanzapine in the previous 3 months (mean length of 27 days ± 20) were recruited through Peninsula Health Psychiatric Services and were randomly assigned to either the intervention (n = 29) or the control group (n = 22). Individuals in the intervention group received six 1 hour nutrition education sessions over a 3-month period. Weight, waist circumference, body mass index (BMI) and qualitative measures of exercise levels, quality of life, health and body image were collected at baseline at 3 and 6 months.


Results: After 3 months, the control group had gained significantly more weight than the treatment group (6.0 kg vs 2.0 kg, p ≤ 0.002). Weight gain of more than 7% of initial weight occurred in 64% of the control group compared to 13% of the treatment group. The control group's BMI increased significantly more than the treatment group's (2 kg/m2vs 0.7 kg/m2, p ≤ 0.03). The treatment group reported significantly greater improvements in moderate exercise levels, quality of life, health and body image compared to the controls. At 6 months, the control group continued to show significantly more weight gain since baseline than the treatment group (9.9 kg vs 2.0 kg, p ≤ 0.013) and consequently had significantly greater increases in BMI (3.2 kg/m2vs 0.8 kg/m2, p ≤ 0.017).