An interim analytic equation of state for sulfurhexafluoride

An interim analytic equation of state for Sulfurhexafluoride is given in the form of a reduced Helmholtz energy function. It represents the thermodynamic properties over the temperature range 222.38 to 525 K for pressures up to 55 MPa. The data selected for determining the linear coefficients of the equation are given, which includes some values predicted using the principle of corresponding states. The method used for the multiproperty fitting is given and, in particular, the functions used for fitting isobaric heat capacities as primary data. Comparisons with values predicted by the equation of state are given for saturation properties, second virial coefficients, densities, and isobaric and isochoric heat capacities. The accuracy of the representation of the equation of state is discussed and, also, the problems arising from inconsistencies between the different data sets. The interim status of this equation of state is due to these inconsistencies.Paper presented at the Tenth Symposium on Thermophysical Properties, June 20–23, 1988, Gaithersburg, Maryland, U.S.A.     

Contaminant Exposure and Biomarker Response in Embryos of Black-crowned Night-herons (Nycticorax nycticorax) Nesting near Lake Calumet,Illinois

We examined a suite of environmental contaminants and exposure endpoints in blackcrowned night-heron (Nycticorax nycticorax, BCNH) embryos collected in 2002 from colonies in Illinois, Minnesota, and Virginia. Embryos from the Lake Calumet, IL, colony had greater exposure to polychlorinated biphenyls (PCBs), 4,4’-dichlorodiphenyldichloroethylene (DDE), dieldrin, transnonachlor, oxychlordane, cobalt, copper, and selenium than did those from northwest MN and coastal VA. Embryos from IL and VA contained greater concentrations of mercury and zinc than those from MN, whereas the latter had greater accumulation of lead. Greater exposure of IL embryos to PCBs was reflected in greater ethoxyresorufin-O-deethylase and benzyloxyresorufin-O-dealkylase induction. However, measures of oxidative stress and genotoxicity were similar to those in embryos from the other colonies examined, and no overt toxic effects of contaminant exposure such as embryo mortality or malformations were observed. Although efforts to clean up the south Chicago environment are ongoing, Lake Calumet BCNH, and undoubtedly other piscivorous wildlife foraging in the region, continue to be exposed to a variety of environmental contaminants. Life-history characteristics of this species make it ideal as an environmental sentinel for the success of the cleanup of the south Chicago environment.     

A model for surface recombination velocity and lifetime ofsemiconductor lasers

A simple and powerful relationship is presented for estimating the lifetime of continuous-wave (CW) diode lasers. Accelerated aging tests can directly be translated into the relationship. A model for the surface recombination velocity is developed based on the physical and chemical phenomenon governing the change of the surface recombination velocity. This model, together with a criterion for no thermal runaway developed earlier, is used to arrive at the simple relationship. The relationship provides a physical basis for estimating the lifetime     

Characterization of glucose transport activity reconstituted from heart and other tissues

We examined several aspects of glucose transport reconstituted in liposomes, with emphasis on transporters of rat heart (mostly GLUT4) compared to those of human erythrocytes (GLUT1), and on effects of agents that modulate transport in intact cells. Several types of samples gave higher reconstituted activity using liposomes of egg lipids rather than soybean lipids. Diacylglycerol, proposed to activate transporters directly as part of the mechanism of insulin action, increased the intrinsic activity of heart transporters by only 25%, but increased the size of the reconstituted liposomes by 90%. The dipeptide Cbz-Gly-Phe-NH2 inhibited GLUT4 with a Ki of 0.2 mM, compared to 2.5 mM for GLUT1, which explains its preferential inhibition of insulin-stimulated glucose transport in adipocytes. Verapamil, which inhibits insulin- and hypoxia-stimulated glucose transport in muscle, had no effect on reconstituted transporters. Heart transporters had a higher Km for glucose uptake (13.4) than did GLUT1 (1.6 mM), in agreement with a recent study of GLUT1 and GLUT4 expressed in yeast and reconstituted in liposomes. Transporters reconstituted from heart and adipocytes were 40-70% inactivated by external trypsin, suggesting the presence of trypsin-sensitive sites on the cytoplasmic domain of GLUT4. NaCl and KCl both reduced reconstituted transport activity, but KCl had a much smaller effect on the size of the liposomes.     

Role of the external nasal dilator in the management of nasal obstruction

The aim of this study is to evaluate the effect of an external nasal dilator in patients with nasal obstruction secondary to mucosal congestion (n = 33) or to septal deviation in the nasal valve area (n = 28). A group of subjects with healthy nasal cavities was tested also (n = 51). Acoustic rhinometric and rhinomanometric nasal measurements were performed with and without the dilator and before and after topical decongestion of the nasal mucosa. A visual analog scale was employed to evaluate the subjective sensation of nasal obstruction. Objective measurements showed that the external dilator increased the minimum cross-sectional area and decreased the nasal resistance significantly in all three groups (P < 0.01). The effect was more impressive in patients with septal deviation (P < 0.001). Subjective assessments reflected patency in all subjects except those in the mucosal swelling group (P = 0.06). From this study the authors conclude that the external nasal dilator offers an effective, nonsurgical therapeutic approach in the management of septal deviation that obstructs the nasal valve area. Although patients with nasal obstruction secondary to mucosal congestion showed objective improvement with the nasal dilator, these changes were not accompanied by a sensation of enhanced patency.     

Reducing cancer risk among Native American adolescents

BACKGROUND: This article discusses the development, implementation, and preliminary testing of an intervention to reduce cancer risks through tobacco use prevention and dietary modification among Native American youth in the Northeastern United States. METHODS: The intervention outcome study includes a research design and outcome measurement instruments. In collaboration with Native American communities, reservations, and organizations in the Northeastern United States, implementation of the design quantifies the separate and combined effects of a tobacco use prevention and a dietary modification intervention. RESULTS: Native American youths in the tobacco prevention intervention and in the combined tobacco and dietary intervention increased their knowledge of tobacco facts and their awareness of the motives of tobacco advertising, and showed higher ratings for an ability to resist peer pressure and to refuse offers of tobacco use between pretest and posttest. Youths in the combined intervention were significantly less apt to report smoking of any kind. Youths in the tobacco use prevention-only condition reported significantly less smoking than their counterparts in the dietary modification-only condition and control condition on 4 of 8 measurement items. As for dietary variables, pretest to posttest measurement scores showed that, after receiving the curriculum, youths in the dietary modification intervention and in the combined intervention improved their knowledge of the health implications of consuming dietary fat, fiber, fruits, and vegetables. Youths in the dietary modification and combined intervention also improved their scores of knowledge related to cancer risk-reducing nutritional practices, cultural dietary habits, and healthy food choices available for Native American cultures. Youths in the dietary modification-only condition report significantly increasing their consumption of complex carbohydrates and significantly decreasing their fat intake between pretest and posttest occasions. CONCLUSIONS: Data from this longitudinal study suggest the value of the FACETS curriculum for helping Native American youth reduce their risks for cancer associated with tobacco use and dietary preference and consumption patterns. In particular, results indicate the enhanced effects of the combined tobacco use prevention and dietary modification intervention for preventing tobacco use and for improving youths' knowledge and attitudes with regard to tobacco use and diet. Further, the study demonstrates the value of collaborating with Native American organizations to design a cancer risk-reducing curriculum and to implement tests of that curriculum.     

Optimal parallel algorithms for point-set and polygon problems

In this paper we give parallel algorithms for a number of problems defined on point sets and polygons. All our algorithms have optimalT(n) * P(n) products, whereT(n) is the time complexity andP(n) is the number of processors used, and are for the EREW PRAM or CREW PRAM models. Our algorithms provide parallel analogues to well-known phenomena from sequential computational geometry, such as the fact that problems for polygons can oftentimes be solved more efficiently than point-set problems, and that nearest-neighbor problems can be solved without explicitly constructing a Voronoi diagram.     

Coding defensive and supportive communications: Discriminant validity and subcategory convergence.

The Defensive and Supportive Communication (DSC) Interaction Coding System has been used frequently in the study of interactions in families with a juvenile delinquent. One limitation of the DSC system has been the lack of research examining the psychometric properties of the coding system. Discriminant analyses were used to examine the communication behaviors of members of 18 normal and 20 delinquent families and to determine the use of subcategories by different family members. Convergence among the subcategories for each of the main categories, defensiveness and supportiveness, was found. Moreover, each subcategory, with the exception of equality, discriminated between adaptive and dysfunctional families. The strongest discriminations were made on the basis of mothers' and adolescents' ratings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)