Limited recovery following a massive seagrass decline in subarctic eastern Canada

Over the last few decades, there has been an increasing recognition for seagrasses' contribution to the functioning of nearshore ecosystems and climate change mitigation. Nevertheless, seagrass ecosystems have been deteriorating globally at an accelerating rate during recent decades. In 2017, research into the condition of eelgrass (Zostera marina) along the eastern coast of James Bay, Canada, was initiated in response to reports of eelgrass decline by the Cree First Nations of Eeyou Istchee. As part of this research, we compiled and analyzed two decades of eelgrass cover data and three decades of eelgrass monitoring data (biomass and density) to detect changes and assess possible environmental drivers. We detected a major decline in eelgrass condition between 1995 and 1999, which encompassed the entire east coast of James Bay. Surveys conducted in 2019 and 2020 indicated limited changes post-decline, for example, low eelgrass cover (<25%), low aboveground biomass, smaller shoots than before 1995, and marginally low densities persisted at most sites. Overall, the synthesized datasets show a 40% loss of eelgrass meadows with >50% cover in eastern James Bay since 1995, representing the largest scale eelgrass decline documented in eastern Canada since the massive die-off event that occurred in the 1930s along the North Atlantic coast. Using biomass data collected since 1982, but geographically limited to the sector of the coast near the regulated La Grande River, generalized additive modeling revealed eelgrass meadows are affected by local sea surface temperature, early ice breakup, and higher summer freshwater discharge. Our results caution against assuming subarctic seagrass ecosystems have avoided recent global declines or will benefit from ongoing climate warming.

Probabilistic divergence time estimation without branch lengths: dating the origins of dinosaurs, avian flight and crown birds

Branch lengths—measured in character changes—are an essential requirement of clock-based divergence estimation, regardless of whether the fossil calibrations used represent nodes or tips. However, a separate set of divergence time approaches are typically used to date palaeontological trees, which may lack such branch lengths. Among these methods, sophisticated probabilistic approaches have recently emerged, in contrast with simpler algorithms relying on minimum node ages. Here, using a novel phylogenetic hypothesis for Mesozoic dinosaurs, we apply two such approaches to estimate divergence times for: (i) Dinosauria, (ii) Avialae (the earliest birds) and (iii) Neornithes (crown birds). We find: (i) the plausibility of a Permian origin for dinosaurs to be dependent on whether Nyasasaurus is the oldest dinosaur, (ii) a Middle to Late Jurassic origin of avian flight regardless of whether Archaeopteryx or Aurornis is considered the first bird and (iii) a Late Cretaceous origin for Neornithes that is broadly congruent with other node- and tip-dating estimates. Demonstrating the feasibility of probabilistic time-scaling further opens up divergence estimation to the rich histories of extinct biodiversity in the fossil record, even in the absence of detailed character data.

Importance of whole-plant biomass allocation and reproductive timing to habitat differentiation across the North American sunflowers

BACKGROUND AND AIMS

Trait-based plant ecology attempts to use small numbers of functional traits to predict plant ecological strategies. However, a major gap exists between our understanding of organ-level ecophysiological traits and our understanding of whole-plant fitness and environmental adaptation. In this gap lie whole-plant organizational traits, including those that describe how plant biomass is allocated among organs and the timing of plant reproduction. This study explores the role of whole-plant organizational traits in adaptation to diverse environments in the context of life history, growth form and leaf economic strategy in a well-studied herbaceous system.

METHODS

A phylogenetic comparative approach was used in conjunction with common garden phenotyping to assess the evolution of biomass allocation and reproductive timing across 83 populations of 27 species of the diverse genus Helianthus (the sunflowers).

KEY RESULTS

Broad diversity exists among species in both relative biomass allocation and reproductive timing. Early reproduction is strongly associated with resource-acquisitive leaf economic strategy, while biomass allocation is less integrated with either reproductive timing or leaf economics. Both biomass allocation and reproductive timing are strongly related to source site environmental characteristics, including length of the growing season, temperature, precipitation and soil fertility.

CONCLUSIONS

Herbaceous taxa can adapt to diverse environments in many ways, including modulation of phenology, plant architecture and organ-level ecophysiology. Although leaf economic strategy captures one key aspect of plant physiology, on their own leaf traits are not particularly predictive of ecological strategies in Helianthus outside of the context of growth form, life history and whole-plant organization. These results highlight the importance of including data on whole-plant organization alongside organ-level ecophysiological traits when attempting to bridge the gap between functional traits and plant fitness and environmental adaptation.

The role of the posterior cruciate ligament in total knee replacement

OBJECTIVES

The purpose of this study was to examine the effect of posterior cruciate ligament (PCL) retention, PCL recession, and PCL excision during cruciate-retaining total knee replacement.

METHODS

A total of 3018 anatomic graduated component total knee replacements were examined; 1846 of these retained the PCL, 455 PCLs were partially recessed, and in 717 the PCL was completely excised from the back of the tibia.

RESULTS

Clinical scores between PCL groups favored excision for flexion (p < 0.0001), and recession and retention for stairs (p < 0.0001). There was a mild difference in long-term all-cause aseptic survivorship between PCL-retained (96.4% at 15 years) combined with PCL-recessed groups (96.6% at 15 years) when compared with the PCL-excised group (95.0% at 15 years) (p = 0.0411, Wilcoxon; p = 0.0042, log-rank), as well as tibial or femoral loosening, which reported prosthesis survival of 97.8% at 15 years for PCL-retained knees, 98.2% for recessed knees, and 96.4% for excised knees (p = 0.0934, Wilcoxon; p = 0.0202, log-rank).

CONCLUSIONS

Despite some trade off in clinical performance, if the PCL is detached at the time of operation, conversion to a posterior-stabilised prosthesis may not be necessarily required as long as stability in the anteroposterior and coronal planes is achieved.

ERIDAS, a computer program for rapid calculation of internal doses from measurements of people in an emergency

In an emergency involving the deliberate or accidental release of radioactive materials, there could potentially be a large number of people who require monitoring for internal contamination. Doses from these measurements will need to be calculated as quickly as possible. Emergency Response Internal Dose Assessment Software (ERIDAS) has been designed for this purpose.

Long-term deterioration of joint evaluation scores

We investigated the long-term changes in the Harris Hip and Knee Society scores (HSS and KSS) to determine whether they result from overall functional decline rather than actual changes in the condition of the prosthesis. The HHS for 106 total hip arthroplasties with a minimum follow-up of ten years, no medical complications after operation and no evidence of radiological loosening, and the KSS for 264 total knee arthroplasties with a minimum follow-up of 12 years and no medical complications after operation or signs of radiographical loosening were evaluated.

There were statistically significant drops in the functional scoring components of the joint evaluation systems despite no loosening of the prostheses or other significant medical complications. The HHS declined at an average of 0.67 points per year from between three and ten years after operation (p < 0.0001). Contributing to this were deterioration in gait and limp (p < 0.0004), the use of support aids (p < 0.0001), the distance walked (p < 0.0001) and the ability to climb stairs (p < 0.0455). The functional component of the KSS declined significantly at an average 0.88 points per year betwen the third and 12th years (p < 0.0001). There were significant declines in every component of the functional score including the distance walked (p < 0.0001), the ability to climb stairs (p < 0.0001) and the use of support aids (p < 0.0001). The knee score component of the KSS did not decline significantly (p < 0.9750). The combination of functional and pain scores within the HHS system leads to an inaccurate decline in the entire score. The decline of HHS and Knee Society functional scores in total joint arthroplasties, in the absence of implant-related problems, suggests that deterioration in the functional capacity of ageing patients is an important factor in longitudinal studies using these scoring systems.

Intra-operative findings in varus osteoarthritis of the knee. An analysis of pre-operative alignment in potential candidates for unicompartmental arthroplasty

Interest in unicompartmental knee arthroplasty (UKA) for the treatment of medial compartment osteoarthritis has increased in recent years with apparent improvement in the long-term results. This is a result of improved surgical technique, patient selection, and implant design. In an effort further to improve patient selection we analysed the relationship between the pre-operative alignment of the knee and the anatomical findings at the time of surgery. We compared these findings with the indications for UKA. From 4021 total knee arthroplasties we compared intra-operative observations with the pre-operative clinical data in order to identify knees with isolated, medial, compartment changes, which would have been ideal candidates for UKA. We found that only 247 of the knees (6.1%) met anatomical qualifications for isolated, medial, unicompartmental osteoarthritis, and of these, only 168 (4.3%) met clinical standards ideal for UKA. Preoperative alignment showed a significant relationship with patterns of disease. Logistic regression revealed a relationship between pre-operative alignment and intraoperative findings resembling a Gaussian distribution. Patients with a pre-operative varus alignment of 7 degrees were slightly more likely to be selected for UKA. But the further the anatomical alignment in either direction varies from 7 degrees of varus, the more unlikely it is for the knee to exhibit a disease pattern of isolated, medial, unicompartmental osteoarthritis.

T-helper cell tolerance to ubiquitous nuclear antigens

Systemic autoimmune diseases are characterized by the development of antinuclear autoantibodies. In order to understand the immunologic events leading to the development of such antibodies, knowledge of mechanisms of immune tolerance to nuclear antigens is required. By utilizing adoptive T-cell transfer strategies with transgenic mouse models expressing nuclear neo-self antigens, T-cell tolerance to the lupus-related nuclear antigens human La and nRNP A has been demonstrated. These findings also indicate the existence in normal animals of autoreactive B cells continuously presenting nuclear antigen, suggesting that nuclear antigens are not sequestered from the immune system. Investigations of CD4+ T-cell tolerance to non-nuclear antigens have revealed a number of mechanisms that protect the host from autoreactivity, including autoreactive T-cell deletion, regulatory T-cell development and anergy induction. Recent studies using T-cell receptor and neo-self nuclear antigen transgenic mice are revealing the importance of such mechanisms in maintaining tolerance to nuclear antigens. Mechanisms of tolerogenic antigen presentation, identification of tolerogenic antigen source(s) and the pathways leading to loss of tolerance to nuclear antigens in systemic autoimmune disease states are currently being sought.

Severe dating violence and quality of life among south carolina high school students

BACKGROUND

Little research has addressed the impact of dating violence and forced-sex victimization and perpetration on adolescent well-being. In this cross-sectional study, we provide (1) estimates of severe dating violence (SDV) by victimization and perpetration status, (2) estimates of lifetime forced-sex victimization and perpetration, (3) demographic and health behaviors correlated with SDV, and (4) associations between SDV and forced sex and well-being as assessed by (1) health-related quality of life (H-R QOL) and (2) life satisfaction measures.

METHODS

We used a stratified cluster sample of 5414 public high school students, grades 9 through 12, who responded to the 1997 self-administered South Carolina Youth Risk Behavior Survey.

RESULTS

Nearly 12% of adolescents self-reported SDV as a victim (7.6%) or a perpetrator (7.7%), and SDV rates (victimization/perpetration combined) are higher in girls (14.4%) than boys (9.1%). Race, aggressive behaviors, substance use, and sexual risk-taking are correlates of SDV. Among young women, SDV victimization, not perpetration, was associated with recent poor H-R QOL and suicide ideation or attempts, but not lower life-satisfaction scores. Among young men, SDV perpetration, not victimization, was strongly associated with poor H-R QOL and suicide attempts, and lower scores for all domains of life satisfaction.

CONCLUSIONS

This research provides evidence that SDV and forced sex are associated with poor H-R QOL, low life-satisfaction scores, and adverse health behaviors in adolescent female victims and male perpetrators. Screening for dating violence is needed to identify and intervene early to reduce the impact of dating violence.

The induction of SOS function in Escherichia coli K-12/PQ37 by 4-nitroquinoline oxide (4-NQO) and fecapentaenes-12 and -14 is bile salt sensitive: implications for colon carcinogenesis

The response of Escherichia coli to genotoxic agents involves the triggering of a complex system of genes known as the SOS response. In E. coli PQ37, a test organism used for the assessment of genotoxicity, lacZ, the beta-galactosidase gene is placed under the control of sfiA, one of the SOS genes through an operon fusion. The induction of beta-galactosidase activity, when the organism is exposed to genotoxic agents, is an indirect measure of the genotoxic activity of the test compound. Incubation of E. coli PQ37 with either 4-nitroquinoline oxide (4-NQO) or one of the fecal mutagens, fecapentaene-12 or -14 (F-12 or F-14) in the presence of sodium taurocholate or sodium deoxycholate resulted in a significant enhancement of induction of beta-galactosidase activity. The molecular mechanisms of 4-NQO-induced mutagenesis in E. coli are similar to those of the effects of UV light in which both replication-dependent and repair-dependent pathways of mutagenesis exist. Since E. coli PQ37 is excision-repair-deficient, alternate pathways are involved in this system. Bile salts by themselves do not trigger the SOS response, and hence their role in enhancing the SOS-inducing potency of mutagens may involve the potentiation of the cleavage-inactivation of lexA (repressor of SOS) by the protein product of the SOS-controlled gene, recA. The potentiating effect of bile salts on the fecal mutagens, F-12 and F-14, has implications in their suspected role in colon carcinogenesis associated with high-fat, low-fiber diets.

Research on stalking: what do we know and where do we go?

Findings of the article in this two-volume series on stalking are reviewed. Building on the findings of the National Violence Against Women Survey (Tjaden & Thoennes, 1998), this series of studies adds to the literature in defining and measuring stalking behaviors. Repeated stalking victimization is reported by up to 62% of young adults, although frequencies depend on the sample and the precise definition used. Self-definitions of stalking victimization may be quite different from legal definitions. Although the majority of legally defined stalkers (where victim fear is a key component) are men stalking women, studies utilizing other definitions find many more women as stalkers, with no significant gender differences in many studies. In many cases, it does appear that stalking is one part of a larger pattern of relationship physical and psychological abuse. Data on emotional reactions and coping strategies of victims are also reviewed, along with findings on characteristics of stalkers.

Stalking perpetrators and psychological maltreatment of partners: anger-jealousy, attachment insecurity, need for control, and break-up context

Two studies of the correlates of self-reported courtship persistence, stalking-like behaviors following a relationship break-up, and psychological maltreatment of partners were conducted in samples of male (N = 46 and 93) and female (N = 123 and 110) college students. Approximately 40% (38.5% and 44.6%) engaged in at least one stalking behavior following a break-up. A total of 10.7% (study 1) and 7.6% (study 2) engaged in 6 or more stalking behaviors. Stalking was significantly related to psychological maltreatment of the partner (PMP) prior to the break-up. Being the recipient of the breakup was associated with feelings of anger, jealousy and obsessiveness and with higher levels of courtship persistence, and stalking. A replicated path model showed that anxious attachment and need for control were related to PMP and that need for control had a direct contribution to stalking. For anxious attachment, its connection to stalking was indirect, mediated by the degree of anger-jealousy over the break-up.

An oral health promotion programme for nursing caries

AIM

To evaluate an oral health promotion programme involving health visitors and mothers of 8-month-old babies in order to address some of the risk factors associated with nursing caries.

DESIGN

Two cross-sectional studies using postal questionnaires.

SAMPLE

A random sample of 250 mothers who had not received the oral health promotion programme and 250 mothers who had received the programme.

SETTING

The City of Salford.

RESULTS

The oral health promotion programme significantly improved mothers recall of advice given by health visitors encouraging the use of a feeder cup, brushing their babies' teeth with fluoride toothpaste and restricting sugary foods and drinks. Significant improvements were also found in recall of advice regarding the use of sugar-free medicine and registering babies with a dentist. The programme encouraged a higher proportion of the mothers to bring their children to clinics for a hearing check.

CONCLUSION

A simple oral health promotion programme facilitated by health visitors improved recall of advice and clinic visiting behaviour.

Lectin binding to human colonocytes is predictive of colonic neoplasia

OBJECTIVE

The aim of this study was to determine whether lectin binding to exfoliated human colonocytes could be used as a noninvasive test for colorectal polyps or cancer.

METHODS

Colonocytes were harvested from 31 patients (10 controls, 10 with adenomatous polyps, and 11 with cancer), incubated with a panel of fluorescent-labeled lectins, and assayed by flow cytometry.

RESULTS

The lectins jacalin (JAC) and wheat germ agglutinin (WGA) were useful in predicting the presence of a colorectal neoplasm (p = 0.0018 for JAC and p = 0.0099 for WGA). For JAC, sensitivity reached 81% with a specificity of 80%, and for WGA the sensitivity and specificity were both 75%.

CONCLUSIONS

Lectin binding to human colonocytes can predict the presence of malignant and premalignant lesions of the colon, and has potential as a noninvasive screening tool for colorectal neoplasms.

Multiple signaling pathways regulate cell surface expression and activity of the excitatory amino acid carrier 1 subtype of Glu transporter in C6 glioma

Neuronal and glial sodium-dependent transporters are crucial for the control of extracellular glutamate levels in the CNS. The regulation of these transporters is relatively unexplored, but the activity of other transporters is regulated by protein kinase C (PKC)- and phosphatidylinositol 3-kinase (PI3K)-mediated trafficking to and from the cell surface. In the present study the C6 glioma cell line was used as a model system that endogenously expresses the excitatory amino acid carrier 1 (EAAC1) subtype of neuronal glutamate transporter. As previously observed, phorbol 12-myristate 13-acetate (PMA) caused an 80% increase in transporter activity within minutes that cannot be attributed to the synthesis of new transporters. This increase in activity correlated with an increase in cell surface expression of EAAC1 as measured by using a membrane-impermeant biotinylation reagent. Both effects of PMA were blocked by the PKC inhibitor bisindolylmaleimide II (Bis II). The putative PI3K inhibitor, wortmannin, decreased L-[3H]-glutamate uptake activity by >50% within minutes. Wortmannin decreased the Vmax of L-[3H]-glutamate and D-[3H]-aspartate transport, but it did not affect Na+-dependent [3H]-glycine transport. Wortmannin also decreased cell surface expression of EAAC1. Although wortmannin did not block the effects of PMA on activity, it prevented the PMA-induced increase in cell surface expression. This trafficking of EAAC1 also was examined with immunofluorescent confocal microscopy, which supported the biotinylation studies and also revealed a clustering of EAAC1 at cell surface after treatment with PMA. These studies suggest that the trafficking of the neuronal glutamate transporter EAAC1 is regulated by two independent signaling pathways and also may suggest a novel endogenous protective mechanism to limit glutamate-induced excitotoxicity.

The effect of tibiotalar fixation on foot biomechanics

Contact areas and peak pressures in the posterior facet of the subtalar and the talonavicular joints were measured in cadaver lower limbs for both the normal limb and after fixation of the tibiotalar joint. Six joints were fixed in neutral, in 5-7 degrees of varus and of valgus. Ten degrees of equinus angulation was also studied. Each position of fixation was tested independently. Neutral was defined as fixation without coronal or sagittal plane angulation compared with prefixation alignment of the specimen. When compared with normal unfused condition, peak pressures increased, and contact areas decreased in the subtalar joint for specimens fixed in neutral, varus, and valgus. However, the change in peak pressure for neutral fusion compared with normal control was not statistically significant (P > 0.07). Peak pressures for varus and valgus fixation were significantly different from normal (P < 0.001). Contact areas for all positions of fixation were significantly different from normal (P < 0.001). Coronal plane angulation, however, also resulted in significantly lower contact areas compared with neutral fixation (P < 0.001). Contact areas and peak pressures in the talonavicular joint did not appear to be substantially affected by tibiotalar fixation with coronal plane angulation. Equinus fixation qualitatively increased contact areas and peak pressures in the talonavicular and posterior facet of the subtalar joint. Neutral alignment of the tibiotalar joint in the coronal and sagittal planes altered subtalar and talonavicular joint contact characteristics the least compared with normal controls. Therefore, ankle fusion in the neutral position would be expected to most closely preserve normal joint biomechanics and may limit the progression of degenerative arthrosis of the subtalar joint.

V3 seroreactivity and sequence variation: tracking the emergence of V3 genotypic variation in HIV-1-infected patients

OBJECTIVE

To investigate the relationship between V3-specific immune responses and viral quasispecies evolution in 10 HIV-1-seropositive patients enrolled in a phase I trial of recombinant gp160.

METHODS

Serologic responses to the HIVLAI V3 loop and autologous V3 loop DNA sequences were sequentially determined over a 3-4-year interval.

RESULTS

Six patients either seroconverted or had a > or = 42-fold boost in titer to the V3 reagent associated with an average of 3.2 amino-acid changes in their autologous V3 loops. Four patients with < or = 11-fold change in titer to the V3 loop showed an average of 0.75 amino-acid changes. Attempts to measure autologous V3 loop responses in four patients using a peptide enzyme-linked immunosorbent assay technique did not show a distinct binding preference for autologous versus heterologous V3 loop peptides. Thus, we interpret seroreactivity to the heterologous HIVLAI V3 loop to reflect the broadness of the V3 immune response rather than a direct measure of epitope-specific immune pressure.

CONCLUSIONS

These data suggest that the broadness of serologic responses to viral epitopes are reflected in the rate of evolution of their cognate coding sequences and support the view that the immune response to HIV-1 results in the continuous selection of new viral variants during the course of disease.

Glucose modulates rat substantia nigra GABA release in vivo via ATP-sensitive potassium channels

Glucose modulates beta cell insulin secretion via effects on ATP-sensitive potassium (KATP) channels. To test the hypothesis that glucose exerts a similar effect on neuronal function, local glucose availability was varied in awake rats using microdialysis in the substantia nigra, the brain region with the highest density of KATP channels. 10 mM glucose perfusion increased GABA release by 111 +/- 42%, whereas the sulfonylurea, glipizide, increased GABA release by 84 +/- 20%. In contrast, perfusion of the KATP channel activator, lemakalim, or depletion of ATP by perfusion of 2-deoxyglucose with oligomycin inhibited GABA release by 44 +/- 8 and 45 +/- 11%, respectively. Moreover, the inhibition of GABA release by 2-deoxyglucose and oligomycin was blocked by glipizide. During systemic insulin-induced hypoglycemia (1.8 +/- 0.3 mM), nigral dialysate GABA concentrations decreased by 49 +/- 4% whereas levels of dopamine in striatal dialysates increased by 119 +/- 18%. We conclude that both local and systemic glucose availability influences nigral GABA release via an effect on KATP channels and that inhibition of GABA release may in part mediate the hyperexcitability associated with hypoglycemia. These data support the hypothesis that glucose acts as a signaling molecule, and not simply as an energy-yielding fuel, for neurons.

Fine structure mapping of the human X-linked hypophosphatemic rickets gene locus

X-linked hypophosphatemic rickets (HYP) is an X-linked dominant disorder characterized by decreased renal tubular phosphate reabsorption and consequent hypophosphatemia. Renal cross-transplantation studies in Hyp mice indicate that the disorder is secondary to the elaboration of an as yet unidentified humoral factor. A full understanding of the pathophysiology of the disease and the nature of this factor will be facilitated by identification of the HYP gene. Efforts to isolate the HYP gene have been deterred by limited precision in the map of the Xp22.1 region and the consequent distance between DXS365 and DXS274, the previously discovered flanking markers for the HYP gene. To map the HYP region precisely, HYP family resources from two groups of investigators were combined, and several newly available microsatellite repeat probes were tested for linkage to HYP. Our data indicate that DXS365, DXS3424, DXS443, DXS1052, DXS274, and DXS1683 are tightly linked to the HYP gene and suggest a locus order of: Xtel-DXS315-(GLR/DXS43)-DXS257-(DXS443+ ++-DXS3424)-DXS365-HYP-DXS1683-DXS1052-DXS 274-(DXS41/DXS92)-DXS451-Xcen. The HYP gene is located in the 350- to 650-kilobase region between DXS365 and DXS1683. These results will provide a basis for the isolation of candidate genes from the region.

Attachment style, gender, and relationship stability: a longitudinal analysis

Adult attachment styles in 354 heterosexual couples in serious dating relationships were examined. Principal findings included the following: (a) male and female attachment styles were nonrandomly paired, for example, no anxious-anxious or avoidant-avoidant pairs were found; (b) male and female styles related to concurrent relationship ratings of both partners in different but theoretically meaningful ways; (c) male and female styles contributed significantly to longitudinal prediction of relationship stability and status, even when prior duration and commitment to the relationship were statistically controlled; (d) specifically, relationships of avoidant men and of anxious women were surprisingly stable over 3 years, particularly in light of the relatively poor ratings of these relationships by both partners at Time 1. Discussion focuses on the need to integrate gender role considerations and relationship dynamics and processes into theorizing on adult attachment.

Attachment style, gender, and relationship stability: a longitudinal analysis

Adult attachment styles in 354 heterosexual couples in serious dating relationships were examined. Principal findings included the following: (a) male and female attachment styles were nonrandomly paired, for example, no anxious-anxious or avoidant-avoidant pairs were found; (b) male and female styles related to concurrent relationship ratings of both partners in different but theoretically meaningful ways; (c) male and female styles contributed significantly to longitudinal prediction of relationship stability and status, even when prior duration and commitment to the relationship were statistically controlled; (d) specifically, relationships of avoidant men and of anxious women were surprisingly stable over 3 years, particularly in light of the relatively poor ratings of these relationships by both partners at Time 1. Discussion focuses on the need to integrate gender role considerations and relationship dynamics and processes into theorizing on adult attachment.

The effectiveness of Florida's "Improved Pregnancy Outcome" program

The development of a national program to assure access to prenatal care for all women, regardless of income, is believed to be an effective means of reducing low birthweight and neonatal mortality in the U.S. Yet scarce empirical evidence concerning the effectiveness of large-scale prenatal care programs is available. This paper summarizes an evaluation of a statewide public prenatal care program which grew out of the federal Improved Pregnancy Outcome (IPO) project. Using linked birth and infant death-certificate data, and IPO program records from a four-year period (1985-1988), this study compares the neonatal mortality rates of participants of Florida's IPO program with those of a matched comparison group. The results indicate an inverse relationship between IPO participation and the risk of neonatal mortality in a low-income population. These findings suggest that large-scale prenatal care programs can be effective in improving birth outcomes.

Toward the financial integration of public mental health services

The public treatment of seriously mental ill patients continues to be frustrated by the lack of administrative and financial integration of state and community mental health services. Several states have initiated attempts to improve the cost-effectiveness of public mental health services through mechanisms that create financial incentives fostering community-based alternatives to psychiatric hospitalization. Examples of such mechanisms include capitation financing systems, performance contracts, regional mental health authorities, utilization review, and bed-targets. This paper reviews evidence supporting the need for and success of these efforts, and also addresses their limitations.

Porcine von Willebrand disease and atherosclerosis. Influence of polymorphism in apolipoprotein B100 genotype

The relationship of apolipoprotein-B genotype (Lpb) to diet-induced hypercholesterolemia and atherosclerosis was studied in von Willebrand disease (vWD) and normal pigs. Von Willebrand and normal pigs developed comparable levels of hypercholesterolemia (respectively, 757.9 +/- 49.4 versus 772.8 +/- 47.9 mg/dl, P = 0.95). Pigs with Lpb1/5 and Lpb5/8 genotypes, however, developed significantly higher serum cholesterol levels than those with other Lpb genotypes (866.1 +/- 64.0 mg/dl, P = 0.0343). Coronary and aortic atherosclerosis, measured by computer-assisted automated image analyzer, were not significantly different between vWD and normal pigs. Pigs with an Lpb5 allele developed significantly more atherosclerosis than those with the Lpb3/8 or Lpb8/8 genotypes or the rare Lpb1 allele (r greater than or equal to 0.434, P less than or equal to 0.05). Polymorphism in apolipoprotein B100 genotype, then, significantly influenced the severity of diet-induced hypercholesterolemia and atherosclerotic plaque formation in vWD and normal swine without regard to the vWD genotype.

The Galt Visiting Scholar in Public Mental Health: a review of a model of state-university collaboration

The Galt Visiting Scholar in Public Mental Health program was developed in Virginia to strengthen the relationships between the Virginia Department of Mental Health, Mental Retardation, and Substance Abuse Services and the Commonwealth's three medical schools. We describe the development and evolution of this program and its accomplishments to date. Despite significant accomplishments, many of the key recommendations of previous Galt Scholars have not been enacted. The Galt Scholar approach of a consultant model is discussed and analyzed structurally using consultation theory. This analysis demonstrates both the potentials and limits of consultant models of state-university collaboration.

Disorder-to-Order Transition in Settling Suspensions of Colloidal Silica: X-ray Measurements

Dispersions of colloidal particles exhibit thermodynamic properties similar to those of molecular systems, including a hard sphere disorder-to-order transition. In experiments with organophilic silica in cyclohexane, gravity settling was used to concentrate the particles. With small particles the slow sedimentation permits rearrangement into the iridescent ordered phase, but larger particles form amorphous sediments instead. Scanning electron microscopy of the crystalline sediment indicates hexagonally closepacked layers. X-ray attenuation measurements reveal a discontinuity coincident with the observed boundary between iridescent and opaque regions. Sediments accumulating faster than the maximum rate of crystallization produce a glass, in accord with the classical theory for crystal growth.

Changing health practices: the experience from a worksite health promotion project

This paper uses data from an employee health promotion project for government employees to examine initial health practices and their relationship to social and demographic variables. It then uses data collected one year later to examine changes in health behaviors and to try to explain what types of people are most likely to undertake health behavior changes in a year, within the context of a worksite health promotion project. Most people in this sample of employees do make positive changes in health habits in at least one of the following areas: smoking, seatbelt usage, diet, exercise, alcohol usage. While a variety of different social and demographic variables are important in explaining initial differences in health practices, these same variables along with measures of personal efficacy and job stress are poor predictors of whether people change their health behavior over a year. Future research might usefully focus on more detailed collection of qualitative data to help understand what factors motivate people to change health behavior. Future survey approaches may then incorporate broader and more diverse categories of explanatory variables into regression models.

Determinants of participation in worksite health promotion activities

A model of risk factors and psychosocial variables that should enhance the prediction of participation in worksite health promotion programs was evaluated in a sample of 357 States employees in South Carolina. Degree of satisfaction with one's current health status, intent to change it, and participation in a relevant program were assessed in four health areas: weight, exercise, alcohol consumption, and the handling of stress and tension. In each area, a known risk factor was used to predict intent to change and participation during a one-year interval. Variables from the psychosocial model were added in a step-wise regression procedure. The key variables in the psychosocial model were personal efficacy, job stress, and trait anxiety. Neither intent to change a health relevant behavior nor degree of satisfaction with the health area were consistently associated with subsequent participation in a relevant health promotion program. The regression model was a statistically significant predictor of actual participation in two cases: exercise and weight control. For exercise, participators tended to be persons whose job stress was high (r = 0.15) and whose anxiety was high (r = 0.16). In the case of weight control, those who were high in the body mass index (r = 0.22) and in job stress (r = 0.15) were more likely to participate. Participants in stress management also had higher levels of job stress.

Morphometric estimation of the numbers of granulosa cells in preovulatory follicles of the ewe

Several lines of evidence suggest that follicular granulosa cells give rise to the large luteal cells of the corpus luteum in the sheep. To further investigate this suggestion, numbers of granulosa cells in preovulatory follicles were estimated by morphometric methods for comparison with a previous estimate of numbers of large luteal cells (9.6 +/- 0.9 x 10(6)). Preovulatory follicles from five Corriedale ewes were obtained after synchronization of the oestrous cycle with the prostaglandin analogue cloprostenol. Morphometry was undertaken using light microscopy of plastic-embedded tissue sectioned at 1 micron. Mitotic index in the membrana granulosa was 0.05 +/- s.e.m. 0.05%. Mean follicular diameter was 6.25 +/- 0.25 mm and there were 7.68 +/- 0.53 x 10(6) granulosa cells per follicle. These results demonstrate a similarity between the number of granulosa cells per follicle and the number of large luteal cells per corpus luteum and thus support the hypothesis that large luteal cells are derived from granulosa cells.

Intent to participate in worksite health promotion activities: a model of risk factors and psychosocial variables

A model of risk factors and psychosocial variables that should enhance the prediction of participation in worksite health promotion programs was evaluated by a sample survey (10% random sample) of approximately 13,000 State employees in South Carolina. The response rate for the survey was 66.3%, n = 854. A split sample strategy was employed to develop and then validate the psychosocial model. Degree of satisfaction with one's current status and intent to change it were assessed in six health areas: weight, nutrition, exercise, cigarette smoking, alcohol consumption, and the handling of stress and tension. In each area, a known risk factor was used to predict degree of satisfaction and intent to change. Variables from the psychosocial model were added in a step-wise regression procedure. The key variables in the psychosocial model were Personal Efficacy (specific to each of five areas), Job Stress, Trait Anxiety, and Health Knowledge. Risk factors contribute significantly to the prediction of dissatisfaction and intent to change in all areas except cigarette smoking and nutrition. The model of psychosocial factors contributed significantly to the prediction of dissatisfaction and intent to change in all areas. Personal Efficacy was significantly related both to dissatisfaction and intent to change, whereas the Job Stress and Anxiety variables were more effective in predicting dissatisfaction than intent to change. Health Knowledge had little direct or interactive effects on dissatisfaction or intent to participate. The implications of these findings for health promotion programs were examined.

Who volunteers for adult development research?: research findings and practical steps to reach low volunteering groups

The present study is an attempt to determine volunteering bias in racial, gender, and age groups in an adult development study. Samples were drawn from three different types of organizations in the Columbia, South Carolina SMSA. Volunteering rates were calculated as a function of the number eligible to participate in three age groups: young adult (aged 20-25); 2) middle adult (aged 40-45); and 3) old (aged 60-80). The middle group volunteered at a higher rate than the other two age groups, but this effect was restricted to the white sample. Women volunteered more readily than men, but not among the elderly. Whites volunteered more readily than blacks. In order to overcome these volunteering biases, special recruitment procedures were employed in order to obtain a sample which adequately represents the populations in question.