Fertility after natural disaster: Hurricane Mitch in Nicaragua

This investigation evaluates the effect of Hurricane Mitch on women’s reproductive outcomes throughout Nicaragua. This research aim is achieved by analyzing a unique Nicaraguan Living Standards Measurement Study panel dataset that tracks women’s fertility immediately before and at two time points after Hurricane Mitch, combined with satellite-derived municipality-level precipitation data for the 10-day storm period. Results show higher odds of post-disaster fertility in municipalities receiving higher precipitation levels in the immediate post-Hurricane Mitch period. However, fertility normalizes between disaster and non-disaster areas 4 to 6 years after the storm. These findings suggest that the disruptive effects of a natural disaster such as Hurricane Mitch can have an initial stimulative effect on fertility but that effect is ephemeral.     

The Weight Function Lemma for graph pebbling

Graph pebbling is a network model for studying whether or not a given supply of discrete pebbles can satisfy a given demand via pebbling moves. A pebbling move across an edge of a graph takes two pebbles from one endpoint and places one pebble at the other endpoint; the other pebble is lost in transit as a toll. It has been shown that deciding whether a supply can meet a demand on a graph is NP-complete. The pebbling number of a graph is the smallest t such that every supply of t pebbles can satisfy every demand of one pebble byt a vertex. Deciding if the pebbling number is at most k is \(\Pi _2^\mathsf{P}\)-complete. In this paper we develop a tool, called the Weight Function Lemma, for computing upper bounds and sometimes exact values for pebbling numbers with the assistance of linear optimization. With this tool we are able to calculate the pebbling numbers of much larger graphs than in previous algorithms, and much more quickly as well. We also obtain results for many families of graphs, in many cases by hand, with much simpler and remarkably shorter proofs than given in previously existing arguments (certificates typically of size at most the number of vertices times the maximum degree), especially for highly symmetric graphs. Here we apply the Weight Function Lemma to several specific graphs, including the Petersen, Lemke, \(4\mathrm{th}\) weak Bruhat, and Lemke squared, as well as to a number of infinite families of graphs, such as trees, cycles, graph powers of cycles, cubes, and some generalized Petersen and Coxeter graphs. In doing so we partly answer a question of Pachter, et al., by computing the pebbling exponent of cycles to within an asymptotically small range. It is conceivable that this method yields an approximation algorithm for graph pebbling.     

The Divide Between “Evidenced‐Based” Approaches and Practitioners of Traditional Theories of Family Therapy

Evidenced‐based approaches continue to grow in the field of family therapy. However, practicing family therapists do not always embrace these approaches. In this article, we explore factors contributing to practitioners' concerns with evidence‐based treatments and suggest a broader, more clinically palatable view of evidenced‐based treatment. We also suggest how family therapy researchers, practitioners, and educators might begin to close the researcher–clinician divide in the best interest of all concerned.     

Being involved in the country: Productive ageing in different types of rural communities

Productive ageing recognises the contribution of older people to economic, social and cultural growth and helps build a sustainable community. Being involved in community life is good for individuals and good for society. However, we know very little about the participation of and contribution by people aged 50 and over in rural communities. This research aimed to develop a better understanding of productive ageing in different types of communities in rural Victoria, Australia. An anonymous self-complete postal questionnaire was distributed to a sample of households in twenty rural communities using the Australia Post Unaddressed Select Service. Those householders 50 years of age and older were invited to complete the survey. Data collected allowed examination of social and civic engagement, familiarity with community, the value placed on social relations by people aged 50 years and over, and how community involvement was linked to community sustainability. In particular it attempts to address the question ‘Does social and civic engagement differ across declining, stable and growing rural communities?’ Despite differences among rural communities, this study showed that older people develop and maintain strong community connections and well-functioning social capital and that participation in social activities was associated with feelings of being connected with community. It also identified health issues and lack of options as the main constraints on participation. A key message for policy makers is that older people play an important role in the sustainability of rural communities. There is much to be gained from actively supporting their participation in activities that are connected to ageing well.     

Manipulating motivating operations to facilitate the emergence of mands for a child with autism

Research on the functional independence of verbal operants (Skinner, 1957) has demonstrated inconsistent findings. One explanation may be that these studies have not manipulated the motivating operation (MO) to facilitate the emergence of mands (Hall & Sundberg, 1987; Lamarre & Holland, 1985). In the current study, 1 participant, diagnosed with autism, was taught to tact high-preference and low-preference leisure items, and emergence of mands was tested under varying MO conditions. Results showed the emergence of mands following periods of arranged deprivation, and greater maintenance for a highly preferred relative to a less preferred stimulus. However, mands only emerged when presession tact trials were conducted. These results suggest that in a state of deprivation, transfer of stimulus control from discriminative to motivational conditions may occur without direct training.     

Social externalities,overlap and the poverty trap

Previous studies find that some social groups are stuck in poverty traps because of network effects. However, these studies do not carefully analyze how these groups overcome low human capital investment activities. Unlike previous studies, the model in this paper includes network externalities in both the human capital investment stage and the subsequent career stages. This implies that not only the current network quality, but also the expectations about future network quality affect the current investment decision. Consequently, the coordinated expectation among the group members can play a crucial role in the determination of the final state. We define “overlap” for some initial skill ranges, whereby the economic performance of a group can be improved simply by increasing expectations of a brighter future. We also define “poverty trap” for some ranges, wherein a disadvantaged group is constrained by its history, and we explore the egalitarian policies to mobilize the group out of the trap.     

The Relationship Between Nonsuicidal Self‐Injury and Family Functioning: Adolescent and Parent Perspectives

We explored parent and adolescent reports of family functioning, how this differed if the parent was aware that their child self‐injured, and how parental awareness of self‐injury was related to self‐injury frequency, self‐injury severity, and help seeking. Participants were 117 parent–adolescent dyads, in 23 of which the adolescent self‐injured. Adolescents who self‐injured reported poorer family functioning than their parents, but parents who did not know about their child's self‐injury reported similar functioning to parents whose children did not self‐injure. Parents were more likely to know that their child self‐injured when the behavior was severe and frequent. Help‐seeking was more likely when parents knew about self‐injury. Family‐based interventions which emphasize perspective‐taking could be used to effectively treat self‐injury.     

Conditional moving linear regression: Modeling the recruitment process for ALLHAT

Effective recruitment is a prerequisite for successful execution of a clinical trial. ALLHAT, a large hypertension treatment trial (N = 42,418), provided an opportunity to evaluate adaptive modeling of recruitment processes using conditional moving linear regression. Our statistical modeling of recruitment, comparing Brownian and fractional Brownian motion, indicates that fractional Brownian motion combined with moving linear regression is better than classic Brownian motion in terms of higher conditional probability of achieving a global recruitment goal in 4-week ahead projections. Further research is needed to evaluate how recruitment modeling can assist clinical trialists in planning and executing clinical trials.