Neutron source reconstruction using a generalized expectation-maximization algorithm on one-dimensional neutron images from the Z facility.

Magnetized Liner Inertial Fusion experiments have been performed at the Z facility at Sandia National Laboratories. These experiments use deuterium fuel, which produces 2.45 MeV neutrons on reaching thermonuclear conditions. To study the spatial structure of neutron production, the one-dimensional imager of neutrons diagnostic was fielded to record axial resolved neutron images. In this diagnostic, neutrons passing through a rolled edge aperture form an image on a CR-39-based solid state nuclear track detector. Here, we present a modified generalized expectation-maximization algorithm to reconstruct an axial neutron emission profile of the stagnated fusion plasma. We validate the approach by comparing the reconstructed neutron emission profile to an x-ray emission profile provided by a time-integrated pinhole camera.

Quantitative analysis of the development of experimentally induced post surgical adhesions: a microstereological study.

The aim of this study was to quantitatively define the development of post surgical adhesions (PSAs) in a well characterized experimental model and identify possible windows of pathogenesis where pharmaceutical intervention may be most effective. PSAs were induced, in an established rabbit uterine horn model, using standardized reproducible injury, in 17 experimental groups, each with 8 experimental sites and these PSAs were sampled from 30 seconds to 42 days post surgery. Using design based, unbiased stereology, mean volumes of PSAs and associated tissue damage and reaction per experimental site were calculated for each sample time point. PSA development followed the normal pattern of wound healing with surrounding adjacent tissue having a profound influence and interaction. There was a direct relationship between volume of damage (initial and subsequent) and the volume of injury tissue generated. In vivo weak fibrinous PSAs were present from 10 min following injury, with tenacious fibrinous PSAs present from 1 h and onwards. PSA development can be classified into two distinct stages: (i) PSA modelling - occurring during the first 16 h, in which maximum rate of PSA construction is achieved; and (ii) PSA remodelling - from 16 h onwards. Considering this, PSA prevention should ideally be initiated immediately post injury to prevent PSA modelling or, alternatively, during PSA modelling.

Repeat fertility and contraceptive implant use among Medicaid recipients in Colorado.

Late in 1991, Colorado's Medicaid program approved coverage for the hormonal contraceptive implant among Medicaid recipients. Subsequently, the Colorado Department of Public Health and Environment undertook an analysis of data supplied by the state's Medicaid program of the probability of repeat births among Medicaid recipients. According to life-table analysis of two cohorts of women in the database who had their first Medicaid-eligible birth in 1991 and 1992, the rate of repeat delivery within 24 months of the preceding birth fell from 14.1% among 11,554 women who first delivered in 1991 to 10.6% among 13,624 women who first delivered in 1992. The 25% decline in the rate of repeat births between the two cohorts was statistically significant. These rates were higher among Medicaid-eligible mothers who first gave birth as teenagers-22.3% in the 1991 cohort and 15.9% in the 1992 cohort. Among the 2,739 Medicaid-eligible women who delivered in 1992 and chose to use the implant within six months of delivery, the repeat delivery rate was just 2.5% within 24 months; this proportion was virtually the same among implant users in the 1992 cohort who first gave birth as teenagers (2.3%).

PIP: The hormonal contraceptive implant was approved for use by the US Food and Drug Administration in December 1990, after which Colorado's Medicaid program approved the implant as a program method in November 1991. This paper reports findings on repeat delivery rates and implant use in a population of Medicaid-eligible women in Colorado. Two cohorts of women who had their first Medicaid-eligible birth in 1991 and 1992 were studied. The rate of repeat delivery within 24 months of the preceding birth fell from 14.1% among 11,554 women who first delivered in 1991 to 10.6% among 13,624 women who first delivered in 1992. This 25% decline in the rate of repeat births between the two cohorts was statistically significant. Among Medicaid-eligible mothers who first gave birth as teenagers, the rates were 22.3% in the 1991 cohort and 15.9% in the 1992 cohort. Among the 2739 Medicaid-eligible women who delivered in 1992 and chose to use the implant within 6 months of delivery, the repeat delivery rate was only 2.5% within 24 months. The repeat delivery rate among implant users in the 1992 cohort who first gave birth as teenagers was 2.3%.

How can family planning programs delay repeat teenage pregnancies?

PIP: The Adolescent Family Clinic of Sinai Hospital in Baltimore which opened in 1965 and which provides family planning services to pregnant adolescents and teenage parents in the hope of preventing early repeat pregnancies is partially evaluated. Evaluation of family planning programs working with teenage mothers is complicated by the variability and instability both to the critical socioeconomic contingencies associated with the young woman's motivations to have or avoid having children and in their ongoing exposure to the risk of pregnancy. The problem is to determine how the experiences of these young women who receive family planning services affect those circumstances that alter the timing of subsequent pregnancies. A life table approach in studying the factors related to the onset of the 2nd pregnancy has been used. This technique is designed specifically to study the temporal pattern of events in the fertility process, and its modification allows the tracing of the probability that a 2nd pregnancy has occurred at various durations into the postpartum period. All pregnant women under age 18 who entered the hospital were eligible to participate in the special program; however, because of staff limitations, 40% of 404 women were assigned on a random basis to the hospital's regular prenatal program. The difference in the 2 programs was the degree of education and encouragement offered. Most of the women were seen during their 2nd trimester. After a 1st visit they were closely supervised through the early months of the postpartum period. In all respects the 2 groups of women were identical. All the young women were interviewed shortly after they registered for prenatal care. A year after delivery, over 95% were interviewed again. 2 years later 90% of the original 404 were reinterviewed. The results are from all 3 interviews. The Adolescent Family Clinic program had limited success in preventing unwanted 2nd pregnancies. 3 years after the 1st delivery approximately 50% of both groups had become pregnant again. Analysis of the data reveals that the risk of pregnancy alters markedly as marital situations, motivation to avoid pregnancy, and use of contraception change. A family planning program must deal with these changes. Most young women want to postpone a 2nd pregnancy and are willing to use birth control. However, when frightening or disturbing side effects occur, they often stop using their method. If they are not offered reassurance when problems arise, they may choose to leave matters to chance. Long-term programs offering initial and ongoing family planning services have the best chance of achieving long-term results with teenagers.^ieng