Bounded information dissemination in multi-channel wireless networks

More and more wireless networks and devices now operate on multiple channels, which poses the question: How to use multiple channels to speed up communication? In this paper, we answer this question for the case of wireless ad-hoc networks where information dissemination is a primitive operation. Specifically, we propose a randomized distributed algorithm for information dissemination that is very near the optimal. The general information dissemination problem is to deliver \(k\) information packets, stored initially in \(k\) different nodes (the packet holders), to all the nodes in the network, and the objective is to minimize the time needed. With an eye toward the reality, we assume a model where the packet holders are determined by an adversary, and neither the number \(k\) nor the identities of packet holders are known to the nodes in advance. Not knowing the value of \(k\) sets this problem apart from broadcasting and all-to-all communication (gossiping). We study the information dissemination problem in single-hop networks with bounded-size messages. We present a randomized algorithm which can disseminate all packets in \(O(k(\frac{1}{\mathcal {F}}+\frac{1}{\mathcal {P}})+\log ^2n)\) rounds with high probability, where \(\mathcal {F}\) is the number of available channels and \(\mathcal {P}\) is the bound on the number of packets a message can carry. Compared with the lower bound \(\varOmega (k(\frac{1}{\mathcal {F}}+\frac{1}{\mathcal {P}}))\), the given algorithm is very close to the asymptotical optimal except for an additive factor. Our result provides the first solid evidence that multiple channels can indeed substantially speed up information dissemination, which also breaks the \(\varOmega (k)\) lower bound that holds for single-channel networks (even if \(\mathcal {P}\) is infinity).     

Educational inequality across three generations in Australia

The transfer of advantage and disadvantage across multiple generations is receiving increasing attention in the international literature; however, transfers of resources across multiple generations in Australian families are less well understood. Using a longitudinal dataset of Australian children, we have the opportunity to not only investigate the transfer of educational resources across three generations in Australia, but also investigate the gendered nature of these transfers, which has been a limitation of other studies. We find no evidence of individual grandparent education effects on numeracy and reading scores for grandchildren in Year 3, independent of parent educational attainment and other covariates. However, significant effects on numeracy and reading scores were observed for children in families where both the grandmother and grandfather in maternal and paternal grandparent sets had high educational attainment (a diploma or university qualification), and where either or both the mother and father had a university qualification. These results suggest that the contribution of grandparents to the academic achievement of grandchildren cannot be fully explained by the parent generation and that the concentration of human capital in families contributes to educational inequalities across multiple generations that can be observed by eight years of age.     

Leadership across hierarchical levels: Multiple levels of management and multiple levels of analysis

We examined differences in leadership influence processes, perceptions, and multiple levels-of-analysis effects between close and distant charismatic and contingent reward leadership across three hierarchical levels in 13 Korean companies. Multi-source data revealed that followers' commitment to the leader mediated relationships between leadership and followers' attitudinal, behavioral, and performance outcomes in close situations, but not in distant relationships. Leadership at higher levels of management was positively related to leadership at the next lower level, which in turn related to follower outcomes at the lowest echelon. Multivariate within and between analysis indicated multiple-level effects differing by leader–follower distance and for the variables of interest.     

The Status of Nutrition Education in ACHA College and University Health Centers

Abstract

An assessment of the prevalence and scope of nutrition services offered through 208 randomly selected American College Health Association member student health centers revealed that 79% of the 160 respondents provided some type of nutrition education for students. One-to-one counseling, available at 96% of the institutions, was the most common approach. The larger the school's enrollment, the more likely it was to provide programs in nutrition. All of the institutions with student populations of more than 35,000 offered some type of nutrition service, as did 52% of the 19 schools with enrollments between 2,000 and 5,000. Health educators, nurses, doctors, dietitians, and trained peer educators provided the services, with registered dietitians the most common providers and often coordinators of the programs. Costs to students for nutrition interventions were nominal; weightmanagement programs were the most expensive and showed the greatest variation in content.     

Overseas Field Placement: An Educational Experiment

This paper describes an educational experiment with the placement of second-year students in field settings in the United Kingdom. The practicum assignments were in a rural area of Northern Scotland and in London. The paper also includes a preliminary analysis of the educational goals and the unique personal and professional gains for faculty and students.     

The Numerate Social Worker

Abstract

In social work education, almost all efforts to teach quantitative analysis are relegated to statistics and research courses. This approach suggests that the only value of quantitative thinking is in formal research. Arguing to the contrary, this paper outlines some reasons why numeracy is essential to day-to-day social work practice. The mathematics preparation of social work students is reviewed and some attributes of the numerate practitioner are described. Some beginning steps are recommended to implement the proposed instructional strategy of integrating real-life quantitative modules in the curriculum.

Numerate: marked by the capacity for quantitative thought and expression (Webster's, 1985)     

Does Religion Make a Difference? Assessing the Effects of Christian Affiliation and Practice on Marital Solidarity and Divorce in Britain, 1985–2005

Frequency of divorce and separation among 15,714 adults from the British Social Attitudes data set for 1985–2005 peaked at around 50 years of age, and increased significantly over the period of study. Ratios of marital breakdown were compared between those of no religious affiliation and Christian affiliates with different levels of church attendance. Frequent Christian attendees were 1.5 times less likely to suffer marital breakdown than nonaffiliates, but there was no difference between nonattending Christian affiliates and those of no religion. Infrequent Christian attendees were 1.3 times less likely to suffer marital breakdown compared to nonaffiliates, suggesting that even infrequent church attendance might have some significance for predicting the persistence of marital solidarity.     

Too close to home? The relationships between residential distance to venue and gambling outcomes

Although gambling accessibility is generally viewed as a multidimensional construct, few studies have successfully untangled the specific role of spatial accessibility in determining gambling outcomes relative to other forms (i.e. temporal, social and psychological). In this paper, we explore the association between gambling outcomes and the distance travelled from a person's home to their most-frequented gambling venue. To this end, we conducted a geocoded mail survey of 7044 households in the Northern Territory of Australia. We employed a geographic information system to calculate the network distance from each household to all visited electronic gaming machine (EGM) venues (n = 64). Multivariate regression modelling revealed that, when adjusted for individual and neighbourhood-level characteristics, frequency of venue visitation and gambling participation were inversely related to residential distance from venue. There was no additional distance effect for problem gambling. Spatial accessibility of EGMs is an important determinant of gambling risk and should be explicitly considered by regulators.     

Family and Sexual Orientation: The Family-Demographic Correlates of Homosexuality in Men and Women

Using a nationally representative sample of young adults, I identify the family-demographic correlates of sexual orientation in men and women. Hence, I test the maternal immune hypothesis, which posits that the only biodemographic correlate of male homosexuality is the number of older brothers, and there are no biodemographic correlates of female homosexuality. For men, I find that having one older brother does not raise the likelihood of homosexuality. Although having multiple older brothers has a positive coefficient, it is not significant. Moreover, having any older sisters lowers the likelihood of homosexual or bisexual identity. For women, I find that having an older brother or having any sisters decreases the likelihood of homosexuality. Family structure, ethnicity, and education are also significantly correlated with male and female sexual orientation. Therefore, the maternal immune hypothesis cannot explain the entire pattern of family-demographic correlates. The findings are consistent with either biological or social theories of sexual orientation.