Preequilibrium Asymmetries in the

The physical properties of neutrons emitted from neutron-induced fission are fundamental to our understanding of nuclear fission. However, while state-of-the-art fission models still incorporate isotropic fission neutron spectra, it is believed that the preequilibrium prefission component of these spectra is strongly anisotropic. The lack of experimental guidance on this feature has not motivated incorporation of anisotropic neutron spectra in fission models, though any significant anisotropy would impact descriptions of a fissioning system. In the present work, an excess of counts at high energies in the fission neutron spectrum of ^{239}Pu is clearly observed and identified as an excess of the preequilibrium prefission distribution above the postfission neutron spectrum. This excess is separated from the underlying postfission neutron spectrum, and its angular distribution is determined as a function in incident neutron energy and outgoing neutron detection angle. Comparison with neutron scattering models provides the first experimental evidence that the preequilibrium angular distribution is uncorrelated with the fission axis. The results presented here also impact the interpretation of several influential prompt fission neutron spectrum measurements.

Direct Evidence for Octupole Deformation in

Despite the more than 1 order of magnitude difference between the measured dipole moments in ^{144}Ba and ^{146}Ba, the octupole correlations in ^{146}Ba are found to be as strong as those in ^{144}Ba with a similarly large value of B(E3;3^{-}→0^{+}) determined as 48(+21-29) W.u. The new results not only establish unambiguously the presence of a region of octupole deformation centered on these neutron-rich Ba isotopes, but also manifest the dependence of the electric dipole moments on the occupancy of different neutron orbitals in nuclei with enhanced octupole strength, as revealed by fully microscopic calculations.

Behaviour change and competitive exclusion can explain the diverging HIV-1 and HIV-2 prevalence trends in Guinea-Bissau.

The aim of this study was to determine whether a temporary rise in sexual risk behaviour during war in Guinea-Bissau could explain the observed trends in HIV-1 and HIV-2 prevalence, and to explore the possible contribution of competitive elimination of HIV-2 by HIV-1. A simulation model of the heterosexual transmission of sexually transmitted infections was parameterized using demographic, behavioural and epidemiological data from rural Guinea-Bissau, and fitted to the observed HIV-1 and HIV-2 trends with and without a historic rise in risk behaviour. The observed trends could only be simulated by assuming a temporary rise in risk behaviour. Around 30% of the projected decline in HIV-2 prevalence from a peak of 8.7% to 4.3% in 2010 was due to competitive elimination by HIV-1. Importantly for public health, HIV-1 prevalence was predicted to continue increasing and to become the dominant HIV type by 2010. Data collection is required to validate this prediction.

Age of wife as a major determinant of male-to-female transmission of HIV-2 infection: a community study from rural West Africa.

OBJECTIVE: To examine whether proviral load is important for transmission between spouses, since we have previously found that the proviral load of HIV-2 predicts the severity of infection. DESIGN: Proviral load was examined in 121 HIV-2-infected adults in a rural area of Guinea-Bissau. For the 68 subjects who had a spouse of known HIV status the risk of the spouse being infected was examined. METHODS: Statistical methods for dependent data were used, because several couples were polygamous. RESULTS: Twenty-seven HIV-2-infected men had 52 current wives of whom 17 (33%) were HIV-2-seropositive. Forty-one HIV-2-infected women had 36 current husbands of known HIV serostatus; nine (25%) were HIV-2-positive. In univariate analyses, concordance of female partners of HIV-2-infected men increased with a previous history of prostitution, age of wife, lack of age difference between the spouses, number of previous husbands, number of wives of the man, and the proviral load. The only significant predictor of concordance in multivariate analyses when wives with a history of prostitution were excluded was an age of 45 years or older [odds ratio (OR), 8.68; 95% confidence interval (CI), 2.34-32.22]. This tendency was not explained by the length of current marriage. Although husbands with a high proviral load were more likely to have concordant spouses than those with a low proviral load (< 20 copies/10(5) CD4 cells), this association was not statistically significant (OR, 2.59; 95% CI, 0.90-7.46). Among spouses of HIV-2-infected women, none of the examined factors, including previous prostitution or proviral load in the woman, predicted whether the husband was HIV-2-infected. CONCLUSIONS: Women appear to be more susceptible to HIV-2 infection after 40-45 years of age. The apparent change in susceptibility may be a major reason for the distinctive age pattern of HIV-2 infection observed in West Africa.

PIP: Community studies from Guinea-Bissau have found that 30-40% of HIV-2-infected individuals' spouses are also infected. However, wives aged under 25 years were significantly less likely to be HIV-2-seropositive. A study was conducted to examine whether proviral load is important for HIV transmission between spouses. Proviral load was examined in 121 HIV-2-infected adults in a rural area of Guinea-Bissau. For the 68 subjects with a spouse of known HIV status, the risk of the spouse being infected was studied. Statistical methods were used for dependent data since several couples were polygamous. 27 HIV-2-infected men had 52 current wives of whom 17% were HIV-2-seropositive. 41 HIV-2-infected women had 36 current husbands of known HIV serostatus; 9 were HIV-2-seropositive. Univariate analysis found the concordance of female partners of HIV-2-infected men to increase with a previous history of prostitution, age of wife, lack of age difference between the spouses, number of previous husbands, the number of wives of the man, and the proviral load. The only significant predictor of concordance in multivariate analysis when wives with a history of prostitution were excluded was being of age 45 years or older. That tendency was not explained by the length of current marriage. Among spouses of HIV-2-infected women, none of the examined factors predicted whether the husband was HIV-2 infected. It was concluded that women seem to be more susceptible to HIV-2 infection after age 40-45 years. That change in susceptibility may be a major reason for the distinctive age pattern of HIV-2 infection observed in West Africa.

Neutron dosimetric quantities for several radioisotopic neutron sources.

The fluence-weighted and dose equivalent-weighted average energies, and the spectrum-averaged fluence-to-dose equivalent conversion factors have been calculated for 52 spectrum variations of 20 different radioisotopic neutron sources. An internally consistent method of determination enables comparison of values for different spectra. The methodology and results are presented.

Perioperative nutrition problems. Nursing management.

Because critically ill surgical patients requiring nutritional support have altered metabolic pathways and are frequently hypermetabolic, catabolic, and hyperglycemic, nurses play an important role in monitoring their care. These metabolic changes place the patient at risk for rapid muscle wasting and nutritional depletion. Enteral and parenteral support provide specialized routes for the delivery of nutrients but have inherent risks and complications. Diarrhea and aspiration pneumonia are consistently reported complications of tube feeding on which nurses have a great impact. Further research is critical to improving nursing practice and patient care. CVC infection continues to plague the delivery of parenteral nutrition. Nurses must remain abreast of current research in this area and apply it in the clinical setting to improve patient care.

Biocompatibility of hemoglobin solutions. II. The inflammatory reaction of human monocytes and mouse peritoneal macrophages.

This study explored the inflammatory mechanism of toxicity of hemoglobin solutions (Hb-S). Human monocytes and mouse activated peritoneal macrophages were incubated with seven different solutions. The first four consisted of non-cross-linked bovine Hb. Of these, Hb-SI was incompletely purified of stromal phospholipids, Hb-SII was contaminated with environmental bacterial endotoxins, Hb-SIII was pure hemoglobin, and Hb-SIV was pure Hb with the addition of superoxide dismutase (SOD), catalase (CAT), and mannitol (M). The other three solutions were made of pure bovine Hb cross-linked with different agents: Hb-SV, reacted with glutaraldehyde; Hb-SVI reacted with bis-3,5-dibromosalicyl fumarate (DBSF); and Hb-SVII reacted with a ring-opened dialdehyde derivative of 5'(pyro)-phosphate of adenosine (ATP) (o-ATP). The reaction of monocytes and macrophages was studied in terms of (a) O2-derived radicals, as determined by the measurement of H2O2 and lipid peroxides; (b) complement factor C3a desArg; (c) 6-keto-prostaglandin F1 alpha (stable metabolite of prostacyclin); and (d) TxB2 (stable metabolite of thromboxane) released into the culture supernatants. The most significant reactions were obtained with the solutions contaminated with stromal phospholipids or bacterial endotoxins. Pure Hb was less reactive. Further reduction in proinflammatory activity was achieved by the addition of oxygen radical-scavengers (SOD, CAT, and M), or by the cross-linking of Hb with DBSF or o-ATP.

Do multi-lumen catheters increase central venous catheter sepsis compared to single-lumen catheters?

Triple-lumen catheters (TLC) are now routinely used in critically ill and multiply injured patients who require multi-port central venous access. An apparent rise in catheter contamination and catheter-related sepsis (CRS) occurred in patients receiving total parenteral nutrition (TPN) through a TLC as opposed to a single-lumen catheter (SLC). A prospective study was performed to determine rates of catheter contamination and CRS in multiple trauma and general surgical-medical patients who received TPN through TLC's and SLC's. Three hundred seven TLC's and 68 SLC's were placed in 234 patients during a 12-month period. There was no statistically significant difference in the rate of contamination or CRS between the two groups although there was a trend toward increased CRS and contamination in the TLC group. TLC's may be used for short-term administration of TPN without significant increase in catheter contamination or CRS.

Strategies for increasing productivity and revenues in community mental health centers.

Community mental health centers are challenged with the development of strategies for growth and prosperity in a cut-back environment. This paper shares strategies developed by two centers to increase productivity and revenues through the implementation of performance contracting and staff incentive plans. The process of development and implementation of the strategies is described, and the financial and program results are evaluated. Both Centers report substantial increases in productivity and revenues during a multi-year evaluation period. The paper concludes with a discussion of the issue multi-year evaluation period. The paper concludes with a discussion of the issues for community mental health centers to consider in the development of similar strategies.

The urban emergency department: the issue of professional responsibility.

The urban emergency department is routinely asked to manage not only medical emergencies, but also a great variety of social emergencies. This situation is caused in part by budgetary constraints which prevent other agencies from providing 24-hour coverage. In an age of instant access to computerized information, these conditions often result in ethical and legal problems of extreme complexity. A case is presented which raises the issues of confidentiality and liberty in the fiduciary relationship between doctor and patient. The concept of personal care is found to be paramount.