Multiple facility location on a network with linear reliability order of edges

We study the problem of locating facilities on the nodes of a network to maximize the expected demand serviced. The edges of the input graph are subject to random failure due to a disruptive event. We consider a special type of failure correlation. The edge dependency model assumes that the failure of a more reliable edge implies the failure of all less reliable ones. Under this dependency model called Linear Reliability Order (LRO) we give two polynomial time exact algorithms. When two distinct LRO’s exist, we prove the total unimodularity of a linear programming formulation. In addition, we show that minimizing the sum of facility opening costs and expected cost of unserviced demand under two orderings reduces to a matching problem. We prove NP-hardness of the three orderings case and show that the problem with an arbitrary number of orderings generalizes the deterministic maximum coverage problem. When a demand point can be covered only if a facility exists within a distance limit, we show that the problem is NP-hard even for a single ordering.     

The vicious circle: effects of race and class on university entrance in Brazil

Brazil has high levels of socio-economic inequality and an inequitable distribution of access to higher education. How much of this inequality is associated with race or class is an important question in light of the current debate over affirmative action and the suitability of race and social targeted policies. There are those who claim that racial disparities in the educational system are a result of students’ social status and not a result of racism, while others believe race is an important factor that superposes the effect of class. This study uses national survey data from Brazil’s Exame Nacional do Ensino Médio (National Secondary Education Exam [ENEM]) to examine the relationship between race and access to higher education of high school students between 2004 and 2008. The results document a vicious circle which connects the schooling of the young with their race, socio-economic status, and university attendance.     

Assessing the contribution of fallen autumn leaves to airborne fungi in an urban environment

Urban Ecosystems - Many street trees in urban areas are deciduous and drop leaves during autumn. These leaves are a potential growing substrate for fungi, which when aerosolized and inhaled, can...     

If You Want People to Listen to You,Tell a Story

We hypothesized that (a) when people share a meaningful story, as opposed to when they share information, they make their partner listen well, and (b) that narrative-induced listening is positively associated with speakers’ psychological safety and negatively associated with their social anxiety. In Study 1 (N = 45), we showed that a meaningful story is perceived much more as a narrative and higher in narrative quality than two types of informational-discourses (telling about daily routine and describing buildings). In Study 2 (N = 52), we randomly asked participants to either share a meaningful story or tell about their daily routine. The participants sharing a meaningful story reported that their interlocutor was a better listener, d = 0.61, 95% CI |0.32, 0.92|. In Study 3 (N = 42), we compared the effect of sharing a meaningful story to describing buildings, and replicated the results of Study 2, d = 1.10, 95% CI |0.61, 1.59|. Moreover, we found that the perceived listening, which was induced by the narrative, mediated the manipulation effects on psychological safety, and social anxiety. Thus, we concluded that when speakers share meaningful stories they make their partner listen well and consequently experience higher psychological safety and lower feelings of social anxiety.     

Becoming the mother of a child with disabilities: a systematic literature review

The transition to motherhood starts early in pregnancy and is completed when the mother feels competent in caring for the infant. Becoming the mother of a child with disabilities is demanding as their needs are complex. The aim of the review was to appraise completed qualitative and quantitative reports on the challenges of mothers of children with disabilities regarding their own transition to motherhood. A review of the literature was carried out through, first, a computerized search strategy to identify relevant studies from selected databases and, second, quality appraisal and thematic analysis of selected studies. The transition to motherhood of children with disabilities takes place in the inside world at home, the outside world external to home and the ‘going-between’ world of travelling between the two worlds. The mothers are challenged at home to integrate basic infant care with technical care of their children. In the outside world they often struggled to ensure that their children got the necessary professional care. Travelling between their homes and healthcare services posed many problems.     

Large body size for metamorphic wood frogs in urban stormwater wetlands

Constructed wetlands in urban environments may be used by urban amphibian populations for breeding. Yet, few studies have examined the performance of young-of-the-year from created wetlands even though the success of terrestrial life stages is directly linked to the performance of individuals at the egg and larval stage. We assessed how early-stage amphibians developing within constructed stormwater wetlands compared in body size (one metric of performance) to those in nearby natural wetlands. We conducted surveys for wood frog, Lithobates sylvaticus, larvae and young-of-the-year metamorphs at 13 wetlands located in the City of Edmonton, Alberta, Canada and compared metamorph size (a useful metric for fitness and reproductive success) between constructed stormwater and two types of natural wetlands. We related body size to within-wetland parameters (reflecting water chemistry, thermal regimes and physical characteristics) and used an information-theoretic approach to identify predictors of metamorph body size. Abundances of egg masses, larvae and metamorphs were generally lower at stormwater than natural wetlands. Metamorphs exhibited larger body size in stormwater wetlands compared to natural wetlands. Low metamorph abundances and cool, stable water temperatures best explained large body size in stormwater metamorphs. We propose that with increasing urbanization and associated construction of artificial wetlands, size benefits in early developmental stages may help individuals cope with reduced habitat suitability in the terrestrial environment.     

Mangrove forests store high densities of carbon across the tropical urban landscape of Singapore

Tropical forested ecosystems provide multiple ecosystem services to rural and urban landscapes, with carbon storage gaining particular attention. Deforestation due to rural-urban transitions may lead to a reduction in carbon storage ability. Coastal mangrove forests are particularly at risk from deforestation due to their location in the rapidly urbanizing coastal zone, and the city state of Singapore is an extreme example, losing as much as 90 % of its original mangrove cover due to land reclamation and reservoir construction. Knowledge of mangrove ecosystem services may allow better conservation, restoration and incorporation of remaining mangrove patches into the urban landscape. Focusing on the regulating ecosystem service of carbon storage, mangrove carbon stocks have been estimated for Singapore using a combination of field and remote sensing techniques. Biomass carbon showed substantial spatial variation, with old, contiguous mangrove patches containing a higher density of biomass carbon than fragmented, river-fringing or restored mangroves. In total, national biomass carbon equated to 116,117.1 megagrams of carbon (Mg C), and a coarse estimate of the total carbon stock (including soil carbon) suggests that Singapore’s mangroves may store 450,571.7 Mg C. While lower than other regional estimates focused on natural, oceanic mangroves, this is a significant carbon stock for a disturbed, urban mangrove system, and may be equivalent to the average annual carbon emissions of 621,000 residents. This analysis, alongside a review of other urban forest studies, highlights the importance of forested ecosystems such as mangroves in providing a carbon storage ecosystem service to urban areas.     

The Relationship Between Problem Gambling and Attention Deficit Hyperactivity Disorder

Recent studies indicate that treatment-seeking problem gamblers display elevated rates of ADHD and that adolescents who screen positive for ADHD are more likely to engage in gambling, develop gambling problems, and experience a greater severity in gambling problems. This study aimed to (a) compare the prevalence of ADHD in treatment-seeking problem gamblers to the general population; (b) investigate the relationships between ADHD and problem gambling severity, cluster B personality disorders, motor impulsivity, alcohol use, substance use, gender, and age; and (c) investigate the degree to which these factors moderate the relationship between ADHD and problem gambling severity. Participants included 214 adults (154 males, 58 females, 2 unspecified) who sought treatment for their gambling problems at a specialist gambling agency in Melbourne, Australia. Almost one-quarter (24.9 %) of treatment-seeking problem gamblers screened positively for ADHD, which was significantly higher than the 14 % prevalence in a community sample. ADHD was significantly positively correlated with problem gambling severity, motor impulsivity, and cluster B personality disorders, but was not associated with alcohol and substance use, gender or age. None of the factors significantly moderated the relationship between ADHD and problem gambling severity. These findings suggest that a considerable proportion of treatment-seeking problem gamblers report ADHD and that their clinical profile is complicated by the presence of high impulsivity and cluster B personality disorders. They highlight the need for specialist gambling agencies to develop screening, assessment, and management protocols for co-occurring ADHD to enhance the effectiveness of treatment.