Let D be a simple digraph without loops or digons. For any v ∈ V (D), the first out-neighborhood N(v) is the set of all vertices with out-distance 1 from v and the second neighborhood N(v) of v is the set of all vertices with out-distance 2 from v. We show that every simple digraph without loops or digons contains a vertex v such that |N++(v)| ≥ γ|N+(v)|, where γ = 0.657298 . . . is the unique ...

conclusions fear of neighborhood violence is a contributing factor to increased risk of obesity for female african american youth who live in disadvantaged areas. this finding has implications for prevention of obesity among african american women who are at highest risk for obesity in the united states. initiatives that enhance neighborhood safety are critical strategies for obesity prevention...

background: as key determinants of many favorable health and quality of life outcomes, it is important to identify factors associated with mobility and social participation. although several investigations have been carried out on mobility, social participation and neighborhood environment, there is no clear integration of these results. this paper presents a scoping study protocol that aims to...

Neighborhood development is considered as one purpose of sustainable urban development (SUD) and a key action to reach the sustainability. This approach (SUN), enhance this new approach that the city's problems can be expected in return to the neighborhood concept. Applied methodology is based on descriptive-analytical, case study and librarian methods. In continuous, it was used of interview w...

Favorable perceptions of the built and social neighborhood environment may promote outdoor physical activity (PA). However, little is known about their independent and interactive effects on neighborhood-specific outdoor PA. We examined associations of perceived built and social neighborhood environment factors, and their interactions, with objectively-measured neighborhood outdoor moderate-to-...