Regular A-optimal design matrices X = (xij) with xij = ?1, 0, 1

New construction methods of the regular A-optimal design matrices with elements −1, 0, 1 are presented, under assumption of nonhomogeneity of variance error. The presented constructions are based on the incidence matrices of the balanced bipartite weighing designs.     

A Model of Quality of College Life (QCL) of Students in Korea

This study develops and tests a model of quality of college life (QCL) of students in Korea. In this study, QCL of students is conceptualized in terms of needs satisfaction and affect balance. It has been hypothesized that satisfaction with education services, administrative services, and facilities have a significant impact on QCL, which in turn positively influences identification, positive word of mouth, and overall quality of life. The results of a survey on 228 Korean college students largely support the model. Managerial and policy implications are discussed.     

Family Responsibilities,Productivity, and Earnings: A Study of Gender Differences Among Canadian Lawyers

This study examines whether men and women invest in different determinants of productivity and whether these investments affect productivity and salary in different ways. Hypotheses are tested from human and social capital theories that include more direct measures for family responsibilities and family-friendly firm arguments. Data from 670 law firm lawyers were used given they report a standardized measure of productivity in billable hours. Despite men investing more in their careers and women investing more in their families, both report similar productivity and their productivity is affected similarly by these factors. In addition, equally productive men and women are paid the same. The findings further our understanding of productivity and salary and the relevance of family responsibilities and family-friendly firms.

Urban habitats can affect body size and body condition but not immune response in amphibians

Does urbanization affect key life-history traits in native organisms? Some studies show that urban areas reduce diversity in certain taxa, but there is little insight into how these environments affect physiological and ecological traits. Urban areas have distinct physical structure and ecological processes compared to original habitats. The environmental changes associated with urban areas can influence the costs and benefits of different traits and behaviors of local organisms. Some of these effects have been explored in groups such as birds, but we might expect stronger effects in animals with reduced mobility, such as amphibians. Importantly, the effects of urban habitats on amphibians have not been explored, in spite that these are the most threatened vertebrate group in the world. Here, we compared three main traits related to the fitness of amphibians in urban and natural habitats: body size, body condition and immune response. To test the generality of our results, we assessed adult males of four amphibian species. We found that the body size was larger in urban environment populations in three of four studied species, while the body condition was better in the urban populations of two aquatic newt species. Finally, we found no effect of urbanization on the immune response of individuals of any species. In conclusion, we show that different species of amphibians may be affected differently by anthropogenic habitat alteration depending on their specific ecology.     

Nitrogen retention and loss in unfertilized lawns across a light gradient

A desirable function for terrestrial urban ecosystems is the mitigation of nitrogen (N) pollution associated with cities and suburbs. To assist in maximizing this function, identifying locations of sources and sinks of N in the urban environment is crucial to inform management strategies. Lawns are an extensive land cover in urbanized landscapes, and in general, they have demonstrated the capacity to function as a sink for N inputs. How N is cycled by lawns, however, is likely not uniform across the physical heterogeneity or management activities that exist in lawns. We investigated the influence of heterogeneity in light availability on N cycling in lawns that were irrigated but not fertilized. Light availability is affected by tree canopy and built structures and is, therefore, heterogeneous both within individual lawns and among lawns. Light is expected to control N retention and loss through effects on primary productivity. We experimentally examined N regulation over one calendar year by measuring net primary production (NPP), N retention using an isotopic tracer, and N leaching in existing unfertilized lawns under heterogeneous light conditions. We used a budgetary approach to estimate gaseous N loss which we assume is primarily via denitrification. Light functioned as a limiting resource for primary productivity. From low to high light conditions, annual NPP increased 177 to 430 g C?m^?2?y^?1 and retention of N isotope tracer increased from 50 to 65% as a result of increased retention in plants. Nitrate leaching losses were low overall and were not affected by light levels. Light availability regulated the fate of N inputs and unfertilized lawns may function as substantial sinks for reactive N through storage in the terrestrial system and N loss by denitrification. However, whether or not denitrification is generally an N sink will depend on the ratio of non-reactive (i.e., N₂) to reactive (i.e., N₂O, NO) denitrification products. Overall, we find that effective strategies for managing N sources and sinks in cities will likely need to consider light availability, particularly in systems receiving water subsidies via irrigation.     

Patterns of pollinator turnover and increasing diversity associated with urban habitats

The role of urban expansion on bee diversity is poorly understood, but it may play an important role in restructuring pollinator diversity observed in rural regions at the urban perimeter. We studied bee communities in two habitats essential for pollinators (residential gardens and semi-natural areas) at 42 sites situated at the edge of greater Montreal, Canada. Bee species richness, abundance and functional diversity all increased with urbanization in both habitat types, but gardens and semi-natural areas supported distinct bee communities with unique responses to urbanization in terms of species turnover. Compared to semi-natural sites, residential gardens supported bees that foraged from a greater number but a lower proportion of available plant species. Bees did not discriminate between exotic and indigenous plant species in either gardens or semi-natural sites and were attracted to flowers in either habitat irrespective of their origins. Protecting semi-natural ruderal areas and providing residential garden habitats for pollinators are both effective means of promoting regional bee diversity in urbanizing regions.     

Living Near to Attractive Nature? A Well-Being Indicator for Ranking Dutch,Danish, and German Functional Urban Areas

While nature is widely acknowledged to contribute to people’s well-being, nature based well-being indicators at city-level appear to be underprovided. This study aims at filling this gap by introducing a novel indicator based on the proximity of city-residents to nature that is of high-amenity. High-amenity nature is operationalized by combining unique systematic data on people’s perceptions of what are the locations of attractive natural areas with data on natural land cover. The proposed indicator departs from the usual assumption of equal well-being from any nature, as it approximates the ‘actual’ subjective quality of nature near people’s homes in a spatially explicit way. Such indicator is used to rank 148 ‘cities’ in the Netherlands, Denmark, and Germany. International comparability of the indicator is enhanced by the use of a definition of cities as functional urban areas (FUAs), which are consistently identified across countries. Results demonstrate that the average ‘nearness’ of FUA populations to high amenity nature varies widely across the observed FUAs. A key finding, that complements insights from existing city-level indicators, is that while populations of FUAs with higher population densities may live relatively far from nature in general, they also live, on average, closer to high-amenity nature than inhabitants of lower density FUAs. Our results may stimulate policy-debates on how to combine urban agglomeration with access to natural amenities in order to account for people’s wellbeing.     

Emergency Saving and Household Hardship

Households with limited income and wealth often struggle to access the financial liquidity needed to address unexpected expenses or income drops. Emergency savings can act as form of insurance against such economic shocks and reduce the risk of hardships that influence family wellbeing. Prior research has established that threshold amounts of liquid assets can reduce the risk of economic hardship. This study used a measure of self-reported emergency saving behavior to examine whether households who reported saving for emergencies were less likely to experience subsequent economic hardships in a longitudinal sample of households in disadvantaged neighborhoods from the Annie E. Casey Foundation’s Making Connections project. Results across a range of regression models suggest that households who saved for emergencies experienced slightly less overall hardship and were less likely to report several specific hardships, such as food insecurity and having a phone disconnected, three years later. This study supports the idea that small, unrestricted savings may play a protective role for low-income households.     

NPO,Internal Controls,and Supervision Mechanisms in a Developing Country

The premise of this paper is that effective supervision and proper internal control system (ICS) can promote accountability and transparency, and this will attract more donors. However, in a developing country like Malaysia, it is common that proper accounting standards are not available, the laws are not enforced, and charities often struggle for survival. Debates on regulating nonprofit organizations (NPOs) have been sensitive to many and are often left unresolved, and some quarters believe that NPOs should be left to handle their own affairs. This paper provides evidence from a survey of 60 charities on the status of their ICS. It briefly describes the current state of regulations in Malaysia and makes a case for better monitoring of the sector, as this might be the reason NPOs are lacking in their ICS. We propose what type of regulation and assistance can be provided by the authorities to this sector, not only in Malaysia but also in other developing countries facing similar challenges.     

The division problem with voluntary participation

The division problem consists of allocating a given amount of a homogeneous and perfectly divisible good among a group of agents with single-peaked preferences on the set of their potential shares. A rule proposes a vector of shares for each division problem. The literature has implicitly assumed that agents will find acceptable any share they are assigned to. In this article we consider the division problem when agents’ participation is voluntary. Each agent has an idiosyncratic interval of acceptable shares where his preferences are single-peaked. A rule has to propose to each agent either to not participate or an acceptable share because otherwise he would opt out and this would require to reassign some of the remaining agents’ shares. We study a subclass of efficient and consistent rules and characterize extensions of the uniform rule that deal explicitly with agents’ voluntary participation.