Search for η

We measured missing mass spectrum of the ^{12}C(γ,p) reaction for the first time in coincidence with potential decay products from η^{'} bound nuclei. We tagged an (η+p) pair associated with the η^{'}N→ηN process in a nucleus. After applying kinematical selections to reduce backgrounds, no signal events were observed in the bound-state region. An upper limit of the signal cross section in the opening angle cosθ_{lab}^{ηp}<-0.9 was obtained to be 2.2 nb/sr at the 90% confidence level. It is compared with theoretical cross sections, whose normalization ambiguity is suppressed by measuring a quasifree η^{'} production rate. Our results indicate a small branching fraction of the η^{'}N→ηN process and/or a shallow η^{'}-nucleus potential.

Differential Cross Section and Photon-Beam Asymmetry for the γ[over →]p → π

Differential cross sections and photon-beam asymmetries for the γ[over →]p→π^{-}Δ^{++}(1232) reaction have been measured for 0.7

Interference Effect between ϕ and Λ(1520) Production Channels in the γp→K

The ϕ-Λ(1520) interference effect in the γp→K^{+}K^{-}p reaction has been measured for the first time in the energy range from 1.673 to 2.173 GeV. The relative phases between ϕ and Λ(1520) production amplitudes were obtained in the kinematic region where the two resonances overlap. The measurement results support strong constructive interference when K^{+}K^{-} pairs are observed at forward angles but destructive interference for proton emission at forward angles. Furthermore, the observed interference effect does not account for the sqrt[s]=2.1 GeV bump structure in forward differential cross sections for ϕ photoproduction. This fact suggests possible exotic structures such as a hidden-strangeness pentaquark state, a new Pomeron exchange, or rescattering processes via other hyperon states.

Spin-density matrix elements for γp→K*0Σ+ at Eγ=1.85-3.0 GeV with evidence for the κ(800) meson exchange.

The exclusive reaction γp→K(+)π(-)Σ(+) was measured for the first time using linearly polarized photons at beam energies from 1.85 to 2.96 GeV. Angular distributions in the rest frame of the K(+)π(-) system were fitted to extract spin-density matrix elements of the K(*0) decay. The measured parity spin asymmetry shows that natural-parity exchange is dominant in this reaction. This result clearly indicates the need for t-channel exchange of the κ(800) scalar meson.

Near-threshold Lambda(1520) production by the gamma(p)-->K{+}Lambda(1520) reaction at forward K+ angles.

Differential cross sections and photon-beam asymmetries for the gamma(p)-->K{+}Lambda(1520) reaction have been measured with linearly polarized photon beams at energies from the threshold to 2.4 GeV at 0.6or=5/2 or by a new reaction process, for example, an interference effect with the phi photoproduction having a similar bump structure in the cross sections.

Work stress and depression among direct support professionals: the role of work support and locus of control.

BACKGROUND: Although work stress can impede the capacity of direct support professionals and contribute to mental health challenges, external (i.e. work social support) and internal resources (i.e. an internal locus of control) have been shown to help DSPs cope more actively. We examined how work stress was associated with depression, with a particular focus on the role of resources. METHOD: Direct support professionals (n = 323) who serve adults with intellectual and developmental disabilities from five community-based organisations completed a cross-sectional, self-administered survey which measured work stress, work support, locus of control, and depression. RESULTS: Multiple regression analyses demonstrated that work stress was positively associated with depression, while resources were negatively associated with depression. In particular, work support moderated the effects of client disability stress, supervisory support lessened the effects of role conflict, and locus of control moderated the effects of workload. CONCLUSIONS: Such findings suggest the importance of external and internal resources for staff mental health. This research underscores the need for strong work social support systems and interventions to help staff manage work stressors.

Galectin-1 regulates initial axonal growth in peripheral nerves after axotomy.

The signals that prompt the axons to send out processes in peripheral nerves after axotomy are not well understood. Here, we report that galectin-1 can play an important role in this initial stage. We developed an in vitro nerve regeneration model that allows us to monitor the initial axon and support cell outgrowth from the proximal nerve stump, which is comparable to the initial stages of nerve repair. We isolated a factor secreted from COS1 cells that enhanced axonal regeneration, and we identified the factor as galectin-1. Recombinant human galectin-1 (rhGAL-1) showed the same activity at low concentrations (50 pg/ml) that are two orders of magnitude lower than those of lectin activity. A similarly low concentration was also effective in in vivo experiments of axonal regeneration with migrating reactive Schwann cells to a grafted silicone tube after transection of adult rat peripheral nerve. Moreover, the application of functional anti-rhGAL-1 antibody strongly inhibited the regeneration in vivo as well as in vitro. The same effect of rhGAL-1 was confirmed in crush/freeze experiments of the adult mouse sciatic nerve. Because galectin-1 is expressed in the regenerating sciatic nerves as well as in both sensory neurons and motor neurons, we suggest that galectin-1 may regulate initial repair after axotomy. This high activity of the factor applied under nonreducing conditions suggests that galectin-1 may work as a cytokine, not as a lectin.

Adhesion of platelets to microcapsules and the role of complement.

Rabbit platelets rapidly adhered to carboxylated polyamide microcapsules through the adsorbed layer of plasma components. These components were found to be heat-labile proteins, which exist in fresh serum, and to demand calcium ions to function. These findings ascribed the components to the complement system. In fact, a good correlation was obtained between platelet adhesion to, and complement fixation by, the microcapsules. Moreover, the activation of the complement system by the microcapsules was assumed to proceed via the classical pathway. It was concluded that adhesion of platelets to the microcapsules is brought about by immune adherence.

Measurement of structure-dependent K+ --> &mgr;(+)nu(&mgr;)gamma decay

We report the first measurement of a structure-dependent component in the decay K+-->&mgr;(+)nu(&mgr;)gamma. Using the kinematic region where the muon kinetic energy is greater than 137 MeV and the photon energy is greater than 90 MeV, we find that the absolute value of the sum of the vector and axial-vector form factors is |F(V)+F(A)| = 0.165+/-0.007+/-0.011. This corresponds to a branching ratio of B(SD+) = (1.33+/-0.12+/-0.18)x10(-5). We also set the limit -0. 04

Further search for the decay K+-->pi(+)nunu;

A search for additional evidence for the rare kaon decay K+-->pi(+)nunu; has been made with a new data set comparable in sensitivity to the previous exposure that produced a single event. No new events were found in the pion momentum region examined, 211pi(+)nunu;) = 1.5(+3.4)(-1.2)x10(-10).

Some catalytic and molecular properties of threonine deaminase from Bacillus stearothermophilus.

Threonine deaminase [EC 4.2.1.16] was highly purified from Bacillus stearothermophilus. The enzyme exhibited maximum activity at 65 degrees and at pH 9.2--9.6. It was inactivated on dilution and on storage at 4 degrees, but was protected by egg albumin. The enzyme was labile at 65 degrees, but became stable in the presence of egg albumin and isoleucine at pH 7.0. The substrate saturation curve for the enzyme reaction at 40 or 65 degrees was hyperbolic, but in the presence of isoleucine, the curve became sigmoidal (n = 2). The enzyme was more sensitive to isoleucine at 40 degrees than at 65 degrees, while valine slightly inhibited the enzyme at both 40 and 65 degrees. Inhibition of the enzyme by isoleucine was antagonized by valine at 40 and 65 degrees. These properties were essentially similar to those of the enzymes from mesophilic and thermophilic bacteria. The enzyme existed in two forms with different molecular sizes, 1.5-5 X 10(6) and 2 X 10(5) daltons, at pH 7.0 and at temperatures below 40 degrees. The larger component disaggregated into the small one at pH 8.5 or above, at temperatures above 50 degrees or in the presence of isoleucine and valine.

Expression of E-cadherin-catenin complex in human benign schwannomas.

The Ca2+-dependent cell adhesion molecule E-cadherin has been known to express in normal and reactive Schwann cells in rodents, and to play an important role in Schwann cell-Schwann cell adhesion and maintenance of peripheral nervous tissue architecture. However, little is known about expression of E-cadherin in schwannomas. The aim of the present study was to investigate the cellular expression and localization of E-cadherin, and its associated protein, alpha E-, alpha N- and beta-catenins in human schwannomas, which are supposed to derive from Schwann cells. We tested the hypothesis that these proteins might show an altered expression/distribution in schwannoma cells which correlates with their neoplastic behavior, including sparse cell-cell contact, as seen those in meningiomas and various carcinomas. In human schwannomas, however, E-cadherin, alpha E-catenin, and beta-catenin were detected by western blotting and immunohistochemistry, whereas alpha N-catenin was not. Immunoprecipitation using anti-E-cadherin antibody resulted in alpha E-catenin forming a complex with E-cadherin. SSCP analysis revealed no mutations in the transmembrane domain or in intracellular catenin-binding site of E-cadherin. These data suggest that the E-cadherin-alpha E-catenin complex is well preserved in human schwannoma cells, which is compatible with its benign behavior, and these molecules might be used as additional cell markers of Schwann cell-derived tumors.

Difference in surface properties between Escherichia coli and Staphylococcus aureus as revealed by electrophoretic mobility measurements.

Electrophoretic mobilities of Escherichia coli and Staphylococcus aureus were measured in media of different pH values and ionic strengths at 310 K and the results were analyzed via a new mobility formula which was derived on the assumptions of uniform charge distribution in the cell surface layer of finite thickness and ion-penetrability in the layer. E. coli was shown to have a more negatively charged and less soft surface than that of S. aureus. It is suggested that electrophoretic mobility measurements can be used to detect the difference in surface structure between gram-positive and gram-negative bacteria.

Study on neurotoxic shellfish poisoning involving the oyster, Crassostrea gigas, in New Zealand.

Lipid-soluble polyether marine toxins were isolated from 80% methanol extract of oysters, Crassostrea gigas, harvested in 1993 at Tiki Road, Coromandel Peninsula, New Zealand, by chromatography on columns of LH-20 and ODS (C18), followed by reversed-phase high-performance liquid chromatography. They were identified as known brevetoxins, PbTx-2 and 3. PbTx-3 was also isolated from oysters collected at Rangaunu Harbour in February 1994 and June 1995, followed by the above procedures.

Hospital provision of institutional long-term care: pattern and correlates.

PURPOSE: This study examined the pattern and correlates of institutional long-term care provision among U.S. community hospitals, differentiating two categories of services: (1) skilled nursing and rehabilitation (SN-R) and (2) other long-term care (O-LTC). DESIGN AND METHODS: Multinomial logistic regression analysis was used to examine the associations of hospital and community characteristics with the pattern of long-term care provision (SN-R only, O-LTC only, both SN-R and O-LTC, and None) among 3,842 hospitals. RESULTS: The pattern of long-term care provision was significantly associated with hospitals' mission (for-profit and teaching status) and their internal and external resources. IMPLICATIONS: Results suggest the importance of considering hospital and community characteristics in predicting the impact of policy changes and in envisioning the role of hospitals in long-term care.

Preparation of poly(D,L-lactide) and copoly(lactide-glycolide) microspheres of uniform size.

In an attempt to prepare monodisperse poly(D,L-lactide) and copoly(lactide-glycolide) microspheres, a novel emulsification technique (membrane emulsification) was employed and the preparation conditions which might affect the monodispersity were evaluated. With this technique nearly monodisperse poly(D,L-lactide) and copoly(lactide-glycolide) microspheres were successfully prepared and their sizes were controllable only by making use of microporous glass membranes of different pore sizes. However, in the present system of emulsion (methylene chloride/water) the surfactant used was limited to ionic ones and the amount of polymers available for the formation of microspheres was inevitably too small in concentration to entrap sufficient amounts of drug. As for the drug release, the effect of particle size was not appreciable but the method of solvent removal gave a great influence; the solvent extraction method showed a more drug-sustaining effect than did the solvent evaporation method. The present results suggest the possibility of making drug-loaded and biodegradable monodisperse microspheres.

Transitions in chronic low back pain in Japanese older adults: a sociomedical perspective.

This study examines the patterns and determinants of chronic low back pain over a three-year period among older adults in Japan. We tested our model based on a sociomedical perspective, using a two-wave national probability sample survey of persons aged 60 and older (N = 2,200) conducted in 1987 and 1990 in Japan. At baseline, the prevalence of chronic low back pain was 18 percent. Among those who were free of back pain at baseline, the probabilities of onset, death, and nonresponse were 13 percent, 7 percent, and 10 percent. Among those who had back pain at baseline, the probabilities of recovery, death, and nonresponse were 43 percent, 8 percent, and 9 percent, respectively. Our multinomial logistic regression analysis supports our thesis that societal factors (age, gender, education, and social relationships) affect transitions in chronic back pain not only directly, but also indirectly through mediating health and health behavior factors. The results suggest that social relationships have both favorable and unfavorable effects on chronic low back pain.

Transitions in functional status and active life expectancy among older people in Japan.

This study analyzes the patterns and determinants of the transitions in functional status among elderly Japanese persons. Data for this research came from a two-wave national probability sample survey of persons aged 60 and over conducted between 1987 and 1990 in Japan. The study focuses on the transitions from two states of origin, "not disable" and "disabled," to three states of destination, "not disabled," "disabled," and "dead." Through multinomial logit analyses, the effects of sociodemographic factors, social relationships, health, and health behavior on transitions in functional status were examined. To assess the impact of panel attrition, the risk of nonresponse was analyzed in conjunction with health transition within the same framework. Finally, an increment-decrement active life table for Japanese elderly people was derived on the basis of the multivariate analyses. According to the life table, a Japanese older person at age 60 is expected to spend about 18.7 years (81%) in functional independence and about 4.4 years (19%) in disability throughout his or her remaining lifetime.

Use of medical care by African American and White older persons: comparative analysis of three national data sets.

Historically, there has been a large gap between African Americans and Whites in access to health care, but this gap was ostensibly lessened by the advent of Medicare and Medicaid for older adults in the mid 1960s. The extent to which older African Americans continue to receive less access to medical care as a result of economic inequalities, institutionalized forms of discrimination, and life-style factors remains a subject of policy debate. Empirical enquiry has produced inconsistent results. The purpose of this study is to test the same set of models of medical use using identically measured predictor variables in three nationally representative data sets of older Americans: 1984 Study of Aging (SOA); 1984 National Long-Term Care Survey (NLTC); and the 1987 National Medical Care Expenditure Survey (NMES). Multivariate logistic regression of use of physician and hospital services and Poisson regression of amount of service use identified inconsistent results in race differences across data sets, but consistent results in terms of the importance of health status and insurance as predictors of use and amount of use. The findings suggest that health status and financial resources may be more relevant areas for policy interventions than considerations related to race and ethnicity.

Determinants of mental health providers' expectations of patients' improvement.

OBJECTIVE: Characteristics of individual mental health providers and of treatment settings were examined to determine their effects on providers' expectations about the improvement of patients with serious mental illness. METHODS: The sample consisted of 1,567 treatment providers working in 107 inpatient and outpatient units or programs in 29 Veterans Affairs mental health facilities. They completed a questionnaire about their prognostic expectations and a broad range of attitudes toward job satisfaction, professional relations, and team functioning. Unit or program directors of all 107 units completed another questionnaire about the average functional ability of patients, unit workload, and unit size. Hierarchical linear modeling was used to assess the effects of both individual and unit-level attributes on providers' expectations of improvement in clinical symptomatology and social-functional skills of patients in their care. RESULTS: The providers had generally low expectations about the improvement of patients with serious mental illness. Expectations were higher among staff in units or programs that were smaller and that had an outpatient focus, a greater proportion of staff involved in the treatment team, and higher-functioning patients. Individual characteristics significantly associated with prognostic expectations were occupation, age, and membership on the treatment team. CONCLUSIONS: Prognostic expectations among providers of care to persons with serious mental illness vary with identifiable individual and unit or program characteristics. The latter may be amenable to manipulation and intervention to improve mental health providers' prognostic expectations.