Min-cost multiflows in node-capacitated undirected networks

We consider an undirected graph G=(VG,EG) with a set T?VG of terminals, and with nonnegative integer capacities c(v) and costs a(v) of nodes v??VG. A path in G is a T-path if its ends are distinct terminals. By a multiflow we mean a function F assigning to each T-path P a nonnegative rational weight F(P), and a multiflow is called feasible if the sum of weights of T-paths through each node v does not exceed c(v). The value of F is the sum of weights F(P), and the cost of F is the sum of F(P) times the cost of P w.r.t. a, over all T-paths P. Generalizing known results on edge-capacitated multiflows, we show that the problem of finding a minimum cost multiflow among the feasible multiflows of maximum possible value admits half-integer optimal primal and dual solutions. Moreover, we devise a strongly polynomial algorithm for finding such optimal solutions.     

Work after stroke: focusing on barriers and enablers

Previous research on work after stroke has used quantitative methods and a medical model approach to identify factors that influence return to work. This study uses an inclusive, qualitative methodology (focus groups) to begin to explore stroke survivors' own perspectives about what helps and hinders paid or voluntary work after stroke. The research was conducted in partnership with Different Strokes, a British organisation of stroke survivors. Five focus group discussions were held with 37 stroke survivors and 12 of their supporters. Data was analysed using an adapted Framework approach to identify themes within and across individuals and groups. Factors representing barriers to or enablers of work were identified in four key themes: rehabilitation process, employer agency, social structural and personal. The study found evidence of social oppression via infrastructure, institutional structures and practices, and some individuals' attitudes. Alongside this, some supportive individuals, practices and strategies were identified.     

Immigrants,visible minorities,and self-employment

Historically, self-employment was perceived as a mechanism whereby immigrants could circumvent discriminatory practices in wage labor. More recent research by Borjas in the United States, however, suggests that this view is incorrect. Immigrants, particularly members of visible minorities, are disadvantaged in both the wage labor and the self-employed markets. This pattern has not been replicated in Canada, however; after controlling for several socioeconomic attributes, it is found that foreign-born, self-employed visible minority-group members are not at a disadvantage in relation to the majority population. Foreign-born visible minority group members earn less, however, in the wage labor force. In contrast, it was found that there is no statistically significant difference between native-born visible minority group members and others in the wage labor force, and that native-born, self-employed minority-group members may earn more than others in that market segment.