A Bayesian belief network for quality assessment: application to employment officer support

BACKGROUND

'Supported' employment stipulates that disabled people should have real jobs for real pay. This paper models kinds of supported employment, assesses how the support and placement features affect its outcomes and its quality from the perspective of the employees, and provides a dynamic model to help explore what types of interventions might promote greater social inclusion for people with learning and other disabilities.

METHOD

Bayesian belief networks (BBNs) provide the general framework for modelling the relationships between the variables and features of interest. The structure, probabilistic specification and quality indicators were elicited from project advisory groups, including people with learning disability, and took into account a pilot survey of 30 individuals. A subsequent survey of 1,461 supported employees was used to update the model and to provide actual assessments of quality of placement.

RESULTS

We present the BBN methodology in some detail, as novel to this discipline. We show how the model was constructed, and its implications for supported employment. We derive indices for quality of placement, taking into account the views of clients. We show how survey and individual results can be used to update the model. Use of the model suggests that quality of placement is, on average, relatively high, with small differences between groups with differing primary disability.

CONCLUSIONS

The BBN is the appropriate methodology to model complex relationships and interventions for problems such as these. The model developed in this study can be used to assess and improve the fit between people and jobs, both at the individual level and for groups of employees, and can take into account different kinds of quality for different stakeholders.

Combined sagittal and coronal plane postural stability model

We present a preliminary study of combined anterior posterior (AP) and medial lateral (ML) sway assuming a classic inverted pendulum with included subtalar movement. Based on a feedback control posture model in the sagittal plane as presented by Maurer and Peterka, we have investigated parameters needed to model ML sway components. Center of pressure (COP) data was collected from a population of 8 normal adults (age 18 to 30 years) using a dual AMTI force plate system. Fourteen different sway metrics were calculated. The collected data was successfully compared to numerous simulations of the model where model parameters were varied and the goal was to reproduce both AP and ML components.

No discrimination against previous mates in a sexually cannibalistic spider

In several animal species, females discriminate against previous mates in subsequent mating decisions, increasing the potential for multiple paternity. In spiders, female choice may take the form of selective sexual cannibalism, which has been shown to bias paternity in favor of particular males. If cannibalistic attacks function to restrict a male's paternity, females may have little interest to remate with males having survived such an attack. We therefore studied the possibility of female discrimination against previous mates in sexually cannibalistic Argiope bruennichi, where females almost always attack their mate at the onset of copulation. We compared mating latency and copulation duration of males having experienced a previous copulation either with the same or with a different female, but found no evidence for discrimination against previous mates. However, males copulated significantly shorter when inserting into a used, compared to a previously unused, genital pore of the female.

Faithful without care: the evolution of monogyny

The traditional paradigm of male polygamy and female monogamy has been replaced by the recognition that both sexes may typically mate with several partners. As a consequence, much attention has focused on the evolution of polyandry, while the evolutionary significance of monogyny (male monogamy) remains poorly understood. Monogyny, a taxonomically widespread mating system that includes dramatic examples of male self-sacrifice, is predicted when the benefits of paternal investment exceed those of searching for additional mates. However, monogyny also occurs in animals lacking paternal investment, instead representing a form of paternity protection. It has been suggested that such mating systems are expected where the costs of mate search for males are high. However, this argument fails to recognize that if there is a low probability of a male finding a mate, then there may be a high probability that he will not need to defend his paternity. Using a mathematical model, we show that monogyny as a means of increasing paternity is favored when the sex ratio is male biased, but not necessarily by high search costs. The importance of a male-biased sex ratio for the evolution of monogyny is supported by various empirical studies.

The transition to social inbred mating systems in spiders: role of inbreeding tolerance in a subsocial predecessor

The social spiders are unusual among cooperatively breeding animals in being highly inbred. In contrast, most other social organisms are outbred owing to inbreeding avoidance mechanisms. The social spiders appear to originate from solitary subsocial ancestors, implying a transition from outbreeding to inbreeding mating systems. Such a transition may be constrained by inbreeding avoidance tactics or fitness loss due to inbreeding depression. We examined whether the mating system of a subsocial spider, in a genus with three social congeners, is likely to facilitate or hinder the transition to inbreeding social systems. Populations of subsocial Stegodyphus lineatus are substructured and spiders occur in patches, which may consist of kin groups. We investigated whether male mating dispersal prevents matings within kin groups in natural populations. Approximately half of the marked males that were recovered made short moves (< 5m) and mated within their natal patch. This potential for inbreeding was counterbalanced by a relatively high proportion of immigrant males. In mating experiments, we tested whether inbreeding actually results in lower offspring fitness. Two levels of inbreeding were tested: full sibling versus non-sib matings and matings of individuals within and between naturally occurring patches of spiders. Neither full siblings nor patch mates were discriminated against as mates. Sibling matings had no effect on direct fitness traits such as fecundity, hatching success, time to hatching and survival of the offspring, but negatively affected offspring growth rates and adult body size of both males and females. Neither direct nor indirect fitness measures differed significantly between within patch and between-patch pairs. We tested the relatedness between patch mates and nonpatch mates using DNA fingerprinting (TE-AFLP). Kinship explained 30% of the genetic variation among patches, confirming that patches are often composed of kin. Overall, we found limited male dispersal, lack of kin discrimination, and tolerance to low levels of inbreeding. These results suggest a history of inbreeding which may reduce the frequency of deleterious recessive alleles in the population and promote the evolution of inbreeding tolerance. It is likely that the lack of inbreeding avoidance in subsocial predecessors has facilitated the transition to regular inbreeding social systems.

Male mate choice and patterns of paternity in the polyandrous, sexually cannibalistic orb-web spider, Nephila plumipes

Studies that investigate patterns of paternity in polyandrous species typically employ double-mating trials, in which the paternity share of each male is established by either the sterile male technique or using genetic markers. However, polyandrous females may mate with more than two males and, in some species, triple-mating trials produce different patterns of paternity from double-mating trials. We investigated patterns of paternity share in triple-mating trials of the sexually cannibalistic orb-web spider Nephila plumipes. These experiments reveal little quantitative changes to paternity share when more than two males mate with the female; the third male apparently diluted the fertilisation success of the second male but not of the first male. Sexual cannibalism had little impact on the fertilisation success of the first male, but greatly increased the fertilisation success of the third male. When offered a choice, males did not prefer to mate with virgin over mated females, but males that chose virgin females were significantly heavier than those that chose mated females.

The asymptotic leading term of anisotropic small-angle scattering intensities. II. Non-convex particles

For anisotropic particulate samples with scattering contrast (delta n)(2), the leading asymptotic term of the scattering intensity, along a direction q (q/q) of reciprocal space, is [4 pi(2)(delta n)(2)/q(4)]sigmaj [1/kappaG.j(+/-q)]. Here, kappaG.j(+/-q)denotes the Gaussian curvature value at the points (labelled by j) of the interphase surface where the normal is either parallel or antiparallel to q. If the Gaussian curvature vanishes at, say, the jth of these points, the corresponding contribution takes the form Cj/qalpha with 2< or = alphaj<4, Cj and alphaj being determined by the local behaviour of the surface. However, the intensity detected by a counter pixel, with opening solid angle deltaomega(q0) along (mean) direction q0, asymptotically still behaves as 4pi(2) (delta n)(2)(deltaomega(q0))/q(4), where S(deltaomega(q0)) is the area of that part of the interface that has its normals inside deltaomega(q0).

Collaboration to implement smoking cessation guidelines during the childbirth continuum

BACKGROUND

Smoking during pregnancy has been linked with such negative outcomes as increased risk for spontaneous abortions, low birth weight, and perinatal and neonatal mortality. In spring 1998 three leading health care systems in San Diego initiated the Trilateral Partnership ("the Partnership"), whose mission is to improve the health and well-being of children. The Partnership chose tobacco control in pregnant women and their families as its first initiative. PROGRAM COMPONENTS-YEAR ONE (1999): Three interventions were developed: intervention by the prenatal care provider, initiation of a referral process to telephone counseling for pregnant women, and intervention for women reporting spontaneously quitting smoking. To date, 83% of the more-than 20,000 women who have been seen in prenatal screening in 28 months counted themselves as nonsmokers. Eleven percent of the women reported they independently stopped smoking once they learned they were pregnant. Six percent reported that they were still smoking. Twenty-three percent of the women reported living in a household with other smokers. PROGRAM COMPONENTS-YEAR TWO (2000): Activity focused on continuing the previous components, hospital intervention for all new mothers at the time of delivery, pediatric intervention at the newborn's visits at 2 and 6 months of age, and development and refinement of a telephone protocol for new parents.

ELEMENTS OF SUCCESS

The noncontroversial topic of encouraging smoking cessation during pregnancy was one that enhanced immediate buy-in by most individuals contacted to support and engage in the program. Strong commitment and financial support from three health care systems opened doors for the Smoke-Free Families staff and increased the program's visibility in the community.

Female control of paternity in the sexually cannibalistic spider Argiope keyserlingi

Sexual conflict theory predicts an antagonistic coevolution, with each sex evolving adaptations and counter-adaptations to overcome a temporary dominance of the other sex over the control of paternity. Polyandry allows sexual selection to operate after mating has commenced, with male and female interests competing for control of fertilization. There are numerous examples of male control of paternity, but few studies have unambiguously revealed female control. Attributing variance in paternity to females is often difficult since male and female influences cannot be separated unambiguously. However, we show that polyandrous female orb-web spiders Argiope keserlingi (Arancidae) control the paternity of their offspring by adjusting the timing of sexual cannibalism. Our experiments reveal that females copulating with relatively smaller males delay sexual cannibalism, thereby prolonging the duration of copulation, and that these males consequently fertilize relatively more eggs.

Chronic disease self-management: improving health outcomes

Chronic disease has become pandemic in the United States, and estimates are that it will affect 148 million people by the year 2030. Patients with chronic illnesses cost the health care system over three times more than individuals without chronic conditions. The US Department of Veterans' Affairs (VA) Sunshine HealthCare Network, composed of VA health care facilities in Florida and Puerto Rico, recognized that the needs of its increasing number of veterans with chronic diseases were unmet by traditional medical interventions. The Network implemented a chronic disease self-management pilot program to evaluate its value for the veteran population. Results of the pilot indicate that this program will make a positive, lasting change in the health status and quality of life for veterans with chronic disease.

[Methodological assessment of nutritional problems as part of a health care initiative for hospitalized children]

A health care initiative has been set up in a French regional hospital to improve the management of children admitted to the pediatric unit. It involves screening these children, aged between 6 months and 5 years, for nutritional problems. Health care professionals are first trained. They then measure and weigh the children according to a predetermined protocol and calculate an indicator (weight/height ratio) using the EPI-INFO computer program. The medical team is notified if a child is found to be over- or underweight and decisions are taken as to whether further investigations will be carried out. The family are interviewed and the child's eating habits are observed. Nutritional advice is given and the child's doctor is informed. This initiative has been planned and analyzed according to recognized good practice in community programs. All the health care professionals involved in the scheme participated during the year of the study. In total, 1,004 children were admitted to the hospital and 964 were included in the study (97. 8%). Of these, 142 children (14.7%) were included after their discharge from the hospital. Sixty-nine children were identified as being over- or underweight, with 25 (2.6%) underweight and 44 (4.6%) overweight. Sixty-five of these children were identified before their discharge from hospital. The notification rate was only 64.5% and the treatment rate was similar. Efficacy was not assessed. This initiative requires the active participation and awareness of the entire health care team. Improvement should be possible with better computer programs, regular data collection and improved efficiency, which is often not the case when dealing with obesity problems.