cssi/SciSciGPT-SciSciNet huggingface dataset:
Students’ perceptions of the credibility and homophily of native and non‐native English speaking teaching assistants

This study provides an initial effort to determine students’ perceptions of native and non‐native English speaking male and female teachers. Native English speaking teachers rated higher than non‐native English speakers on perceived background and attitude homophily and on character, but not on competence. Females were perceived higher than males in character, competence, and background homophily, but not on attitude homophily.
Plastic Instability of Cylindrical Shells With Rigid End Closures

Solutions are obtained for the large plastic deformations of a cylindrical membrane with rigid end closures subjected to an internal pressure loading. A plastic linearly hardening material obeying Tresca's yield criterion and the associated flow rule is considered. It is found that, in general, a shell passes through three stages of deformation, finally assuming a spherical shape. The instability pressure (maximum pressure) may be reached in amy of the stages depending on the length/diameter ratio of the shell and the hardening modulus of the material. Although numerical integration is required to obtain solutions for shells in the first stages of deformation, the solution in the final state is given in closed form. (auth)
A DATA ACQUISITION SYSTEM FOR RAPID KINETIC EXPERIMENTS

A data acquisition system has been developed to collect, analyze and store large volumes of rapid kinetic data measured from a stopped-flow spectrophotometer. A digital minicomputer, with an A/D converter, tape drive unit and formatter, analog recorder, oscilloscope, and input/output terminal interfaced to the stopped-flow spectrophotometer provides the complete system. Timing for actual data collection is generated through internal computer software with inclusion of A/D conversion time. After a simple initialization from the computer console, software programming provides complete interaction between a user and the terminal. The user is directed through the initialization by a series of decision steps. The first step is to choose a data file, either existing or new. Once the desired file is selected, several options including data collection, analysis, storage, and printing are selectable. Ozone decomposition and the rapid reaction between ozone and cyclohexene in neutral solutions were studied using th...
Fractal dimension and approximate entropy of heart period and heart rate: awake versus sleep differences and methodological issues

1. Investigations that assess cardiac autonomic function include non-linear techniques such as fractal dimension and approximate entropy in addition to the common time and frequency domain measures of both heart period and heart rate. This article evaluates the differences in using heart rate versus heart period to estimate fractal dimensions and approximate entropies of these time series.2. Twenty-four-hour ECG was recorded in 23 normal subjects using Holter records. Time series of heart rate and heart period were analysed using fractal dimensions, approximate entropies and spectral analysis for the quantification of absolute and relative heart period variability in bands of ultra low (<0.0033 Hz), very low (0. 0033-0.04 Hz), low (0.04-0.15 Hz) and high (0.15-0.5 Hz) frequency.3. Linear detrending of the time series did not significantly change the fractal dimension or approximate entropy values. We found significant differences in the analyses using heart rate versus heart period between waking up and sleep conditions for fractal dimensions, approximate entropies and absolute spectral powers, especially for the power in the band of 0.0033-0.5 Hz. Log transformation of the data revealed identical fractal dimension values for both heart rate and heart period. Mean heart period correlated significantly better with fractal dimensions and approximate entropies of heart period than did corresponding heart rate measures.4. Studies using heart period measures should take the effect of mean heart period into account even for the analyses of fractal dimension and approximate entropy. As the sleep-awake differences in fractal dimensions and approximate entropies are different between heart rate and heart period, the results should be interpreted accordingly.
Effect of carbon nanotubes on properties of cement-sand-based piezoelectric composites

Carbon Nanotubes (CNTs) were dispersed in a cement-sand-based piezoelectric smart composite as conductive fillers to improve its poling efficiency, leading to a desirable piezoelectric effect. By introducing a small amount of CNTs, continuous electric networks between Lead Zirconate Titanate (PZT) particles were created, thus making the composite poling easier. Specimens were prepared by mixing PZT powders, Portland cement and sand with CNTs, followed by pressing it with a load frame system. The effect of quantity of CNTs ranging from 0 to 1.0 volume percent on properties of the composite, including its piezoelectric coefficient, dielectric constant and loss, and sensing effects, were characterized. It was found that the addition of CNTs facilitated effective poling at room temperature and improved the piezoelectric and dielectric properties of the composite. The composite modified by CNTs achieved optimal properties when the CNTs content was 0.7 vol.%.
Adrenergic control of vascular resistance varies in muscles composed of different fiber types: influence of the vascular endothelium

The influence of the sympathetic nervous system (SNS) upon vascular resistance is more profound in muscles comprised predominately of low-oxidative type IIB vs. high-oxidative type I fiber types. H...
Antibacterial Effects of Butylated Hydroxyanisole (BHA) against Bacillus species

The antibacterial effect of butylated hydroxyanisole (BHA) was evaluated in laboratory media and in two foods. In nutrient broth growth of Bucillus species (three strains of B. cereus, two of which were enterotoxigenic, and one strain each of B. subtilis and B. megaterium) was inhibited by 75 ppm of BHA. In tests with food systems growth inhibition of vegetative cells of these organisms required 1000 ppm in cooked rice and 5000 ppm in strained chicken. The effect of BHA was bacteriostatic at the tested levels (≤ 200 ppm in laboratory media and ≤ 10,000 ppm in the food systems), and viable cells were recovered from all samples. Bacterial growth resumed in samples which contained bacteriostatic levels of BHA after dilution with antioxidant free broth or food.
Kinetics and equilibria for the acid hydrolysis of dichloro(ethylenediamine)platinum(II)

Abstract The specific rate constants and the equilibrium quotients for the successive replacement of chloride ligands by water in aqueous solutions of Pt(en)Cl2 have been evaluated at 15°, 25° and 35° and an ionic strength of 0.318 M. For the reaction: Pt(en)Cl2+H2O→Pt(en)Cl(H2O)++Cl- the equilibrium quotient, Kt, is 2.19±0.11×10−3M at 25°, ΔH° is 4±1 kcal/mol, k1 is 3.4±0.4×10−5s−1, ΔH* is 20±2 kcal/mol. For the reaction: Pt(en)Cl(H2O)++H2O→Pt(en)(H2O)22++Cl- the equilibrium quotient, K2, is 1.43±0.11×10−4M, at 25°, ΔH° is -1±2 kcal/mol, k2 is 4.4±0.6×10−5 s−1, ΔH* is 8±3 kcal/mol.
The binding of cocaine to cyclodextrins.

Cocaine binds into β-cyclodextrin, but not detectably into α- or γ-cyclodextrin, in water solution. NMR studies indicate the geometry of the complex, which is confirmed by molecular mechanics calculations and binding studies on cocaine analogues and cyclodextrin dimers.
Community-based projects for computing majors: opportunities, challenges and best practices

The use of community-based projects has been recognized as having pedagogical and experiential value for computing majors (e.g. [3], [4], [5], [6]). Community-based projects can be valuable learning experiences for computing majors as well as for faculty and community partners. However, these types of projects do present challenges for faculty and should be aligned with desired course outcomes. This panel will discuss the use of community-based projects from multiple perspectives. The expectation is that the panel will serve as a forum for the participants to share the opportunities, challenges, pedagogical motivations, and best practices obtained from prior experience. Exemplar projects will be highlighted. The panel also hopes the session motivates the audience to share their own experiences and sparks the interest of those faculty members who may have no prior experience with community-based projects.
Infection of Endothelial Cells by Common Human Viruses

Common human viruses were evaluated for their ability to replicate in the endothelial cells of human umbilical vein and bovine thoracic aorta in vitro. Infection occurred with most viruses. The susceptibilities of endothelial cells derived from bovine aorta, pulmonary artery, and vena cava were compared. Among the viruses studied, no differences were noted in the ability to grow in endothelial cells from these three large vessels. One virus, herpes simplex virus type 1, was evaluated for its ability to produce persistent infection of endothelial cells. Infection developed and persisted for up to 3 months. After the first week, productive infection was found in less than 1% of cells. Nevertheless, the infection markedly affected the growth and morphology of the endothelial monolayer. Infection with any of several different viruses was noted to alter endothelial cell functions, including adherence of granulocytes, production of colony-stimulating factor, and synthesis of matrix protein. In addition, herpes simplex virus type 1 induced receptors for the Fc portion of IgG and for complement component C3b. These findings indicate that common human viruses can profoundly affect the biology of the endothelium.
Restoration of a translational stop-start overlap reinstates translational coupling in a mutant trpB′-trpA gene pair of the Escherichia coli tryptophan operon

Abstract The trpB and trpA coding regions of the polycistronic trp mRNA of Escherichia coli are separated by overlapping translation stop and start codons. Efficient translation of the trpA coding region is subject to translational coupling, i.e., maximal trpA expression is dependent on prior translation of the trpB coding region. Previous studies demonstrated that the trpA Shine-Dalgarno sequence (within trpB) and/or the location of the trpB stop codon influenced trpA expression. To examine the effect of stop codon location specifically, we constructed plasmids in which different nucleotide sequences preceding the trpA start codon were retained, and only the reading frame was changed. When trpB translation proceeded in the wild type reading frame and terminated at the normal trpB stop codon, trpA polypeptide levels were elevated over the levels observed when translation stopped before or after the natural trpB stop codon. The proximity of the trpB stop codon to the trpA start codon therefore markedly influences trpA expression.
The Value of Baseline Chest Radiograph Reports in the Care of Elderly Patients in an Emergency Department

ABSTRACT The authors used a before/after research design to determine the impact of written reports of baseline chest radiographs (CXRs) on the care of elderly patients during 48 emergency department visits. Internal medicine housestaff completed questionnaires that included inquiries about their treatment plans for the patients both before and after they reviewed reports of baseline CXR results. The investigators compared these answers to determine the proportion of patients for whom baseline CXR reports changed patient management. In addition, three faculty reviewers used the nominal group process, a consensus analysis approach, to measure treatment changes and to estimate benefit to the patients from the alterations in management. The housestaif indicated that written baseline CXR reports caused them to change treatment plans during only 2 (4%) of the 48 visits. In both cases, they provided aggressive treatment for congestive heart failure because of baseline CXR results. The faculty reviewers could find only one case in which baseline CXR findings might have changed their management plans. Moreover, they were not convinced that the treatment changes indicated by the housestaif actually benefitted the patients. These results suggest that written reports of baseline CXRs do not improve the care of acutely ill patients in an emergency department setting.
On the low cycle fatigue deformation of haynes 188 superalloy in the dynamic strain aging regime

A solid solution strengthened wrought cobalt-base superalloy, Haynes 188, which exhibits an excellent combination of high temperature strength, oxidation resistance and tensile ductility is currently used for a variety of components in gas turbine engines. This alloy is particularly effective for long-term applications at temperatures to {approx} 650 C. Although the temperature ranges of its applications encompasses the domain in which dynamic strain aging (DSA) is active, to date there has been little to no information available on the effects of DSA on cyclic deformation and accompanying substructure. The purpose of this paper is to report some recent observations pertaining to the temperature dependence of cyclic stress response and evolving deformation substructure of Haynes 188 between 25 and 1,000 C. Given that this alloy exhibits planar slip and stacking fault fringes and ribbons in the DSA domain, an attempt has been made to discuss the origin of planar slip in this alloy.
Synthesis of pyreno[b]thiophenes

The synthesis of all the isomers of pyreno[b]thiophene namely, pyreno[1,2-b]thiophene, pyreno[2,1-b]thiophene and pyreno[4,5-b]thiophene is described. Their spectral characteristics are also discussed.
The prevalence and predictors of elevated serum aminotransferase activity in the United States in 1999-2002.

OBJECTIVES: The presence of elevated serum aminotransferase activity is a sign of possible underlying liver disease. We aimed to describe the prevalence and associations of elevated serum aminotransferase activity in a recent, nationally representative U.S. survey. METHODS: We described the prevalence and predictors of elevated alanine aminotransferase (ALT >43 IU/L) or elevated aspartate aminotransferase (AST >40 IU/L) activity among 6,823 participants of the National Health and Nutrition Examination Survey (NHANES) conducted between 1999 and 2002. We compared our findings to the results already published based on the NHANES conducted between 1988 and 1994. RESULTS: In NHANES 1999-2002, the prevalences of elevated ALT, AST, or either ALT or AST were 8.9%, 4.9%, and 9.8%, respectively, in the entire population and 7.3%, 3.6%, and 8.1%, respectively, after excluding participants who tested positive for hepatitis C virus (HCV) antibody or reported excessive alcohol consumption. Strong predictors of elevated ALT activity included increasing waist circumference and body mass index, alcohol consumption, male sex, Mexican American ethnicity, decreasing age, and presence of HCV antibody. In NHANES 1988-1994, which employed a different assay methodology, the prevalences of elevated aminotransferases were approximately half of the prevalences we describe in NHANES 1999-2002, but the predictors of elevated ALT activity were similar. CONCLUSIONS: The current prevalence of elevated ALT activity in the United States (8.9%) is more than double that of previously available estimates. This prevalence is very high (7.3%) even among persons without viral hepatitis C or excessive alcohol consumption and is strongly associated with risk factors for nonalcoholic fatty liver disease.
Market signals and relative preference: the moderating effects of conflicting information, decision focus, and need for cognition

Abstract In two experiments, we assess how consumers react to competing signals of service quality by having participants compare a certified repair facility with a shop offering a warranty. Experiment 1 shows that consumers (1) associate superior tangible quality with the certified shop, (2) ascribe the certification's power to its dissipative nature, and (3) anticipate that they would be more disappointed with the certified seller for false signals. Experiment 2 shows that the certifications' perceived superiority is moderated by the consumer's need for cognition (NFC), decision focus (promotion or seeking gains, versus prevention or avoiding losses), and negative (conflicting) market information about the sellers. We find that certifications appeal most to promotion-focused higher-NFC consumers when their only option is a limited warranty and, conversely, certifications appeal least to prevention-focused lower-NFC consumers as long as they can get extended warranties. Implications of the results are discussed.
Development of PEGylated PLGA nanoparticle for controlled and sustained drug delivery in cystic fibrosis

The mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene results in CF. The most common mutation, ΔF508-CFTR, is a temperature-sensitive, trafficking mutant with reduced chloride transport and exaggerated immune response. The ΔF508-CFTR is misfolded, ubiquitinated, and prematurely degraded by proteasome mediated- degradation. We recently demonstrated that selective inhibition of proteasomal pathway by the FDA approved drug PS-341 (pyrazylcarbonyl-Phe-Leuboronate, a.k.a. Velcade or bortezomib) ameliorates the inflammatory pathophysiology of CF cells. This proteasomal drug is an extremely potent, stable, reversible and selective inhibitor of chymotryptic threonine protease-activity. The apprehension in considering the proteasome as a therapeutic target is that proteasome inhibitors may affect proteostasis and consecutive processes. The affect on multiple processes can be mitigated by nanoparticle mediated PS-341 lung-delivery resulting in favorable outcome observed in this study. To overcome this challenge, we developed a nano-based approach that uses drug loaded biodegradable nanoparticle (PLGA-PEGPS-341) to provide controlled and sustained drug delivery. The in vitro release kinetics of drug from nanoparticle was quantified by proteasomal activity assay from days 1-7 that showed slow drug release from day 2-7 with maximum inhibition at day 7. For in vivo release kinetics and biodistribution, these drug-loaded nanoparticles were fluorescently labeled, and administered to C57BL6 mice by intranasal route. Whole-body optical imaging of the treated live animals demonstrates efficient delivery of particles to murine lungs, 24 hrs post treatment, followed by biodegradation and release over time, day 1-11. The efficacy of drug release in CF mice (Cftr -/- ) lungs was determined by quantifying the changes in proteasomal activity (~2 fold decrease) and ability to rescue the Pseudomonas aeruginosa LPS (Pa-LPS) induced inflammation, which demonstrates the rescue of CF lung disease in murine model. We have developed a novel drug delivery system to provide sustained delivery of CF "correctors" and "anti-inflammatories" to the lungs. Moreover, we demonstrate here the therapeutic efficacy of nano-based proteostasis-modulator to rescue Pa-LPS induced CF lung disease.
OBESITY, SES, AND ECONOMIC DEVELOPMENT: A TEST OF THE REVERSAL HYPOTHESIS

Studies of individual countries suggest that socioeconomic status (SES) and weight are positively associated in lower-income countries but negatively associated in higher-income countries. However, this reversal in the direction of the SES-weight relationship and arguments about the underlying causes of the reversal need to be tested with comparable data for a large and diverse set of nations. This study systematically tests the reversal hypothesis using individual- and aggregate-level data for 67 nations representing all regions of the world. In support of the hypothesis, we find not only that the body mass index, being overweight, and being obese rise with national product but also that the associations of SES with these outcomes shift from positive to negative. These findings fit arguments about how health-related, SES-based resources, costs, and values differ across levels of economic development. Although economic and social development can improve health, it can also lead to increasing obesity and widening SES disparities in obesity.
High-intensity CO 2 laser interactions with indium antimonide

The interaction of picosecond CO2 laser pulses with intrinsic and doped indium antimonide at high intensities is investigated both experimentally and theoretically. A consistent theory is presented that explains the phenomena of high-density carrier generation, transient reflectivity, and melting in the semiconductor. All physical parameters become highly nonlinear at high laser intensities and carrier densities. Account was taken of the dynamic energy band-gap shift, changes in the multiphoton absorption cross section and the effective mass of the electron, dynamic reflectivity, and transmission. Keldysh nonlinear carrier generation is found to be essential to explain the experimental observations. The spark formation threshold of both intrinsic and doped InSb was measured to be 4.3 GW/cm2, corresponding to an energy fluence threshold of 0.26 J/cm2, at a laser pulse duration of 45 psec. The pulse duration scaling of the damage threshold is also discussed.
A LONG TERM INCREASE IN BASAL LEVELS OF CORTICOSTERONE AND A DECREASE IN CORTICOSTEROID-BINDING GLOBULIN AFTER ACUTE STRESSOR EXPOSURE

Adrenal glucocorticoids play an important role in mediating many of the behavioral and physiological effects of exposure to stressors. Focus has been primarily on the acute stress-induced rise in glucocorticoids [corticosterone (CORT) in the rat]. There are reports, however, that exposure to chronic stressors can produce an increase in basal CORT and a decrease in corticotropin-binding globulin (CBG). These changes occur subsequent to the stress-induced rise in CORT. The following experiments examined whether exposure to an acute stressor (100 5-set inescapable tail shocks; IS) could also produce long term changes in basal CORT and CBG. We report that a single session of IS results in an increase in basal total serum CORT that persists 48-96 h after IS termination. The increase is present only at the diurnal trough (morning). CBG levels are also decreased for 24-48 h. The decrease is present at both the diurnal peak (evening) as well as the trough (morning). These changes result in an increase in the percent and amount of biologically active CORT (unbound or free). Thus, glucocorticoid-sensitive targets are exposed to high levels of free CORT for several days after IS termination. The long term increase in free CORT reported here may play an important role in mediating some of the effects produced by IS as well as those produced by other acute stressors. (Endocrinology 136: 5336-5342, 1995)
Folding of peptide fragments comprising the complete sequence of proteins. Models for initiation of protein folding. II. Plastocyanin.

Abstract In an attempt to delineate potential folding initiation sites for different protein structural motifs, we have synthesized series of peptides that span the entire length of the polypeptide chain of two proteins, and examined their conformational preferences in aqueous solution using proton nuclear magnetic resonance and circular dichroism spectroscopy. We describe here the behavior of peptides derived from a simple four-helix bundle protein, myohemerythrin. The peptides correspond to the sequences of the four long helices (the A, B, C and D helices), the N- and C-terminal loops and the connecting sequences between the helices. The peptides corresponding to the helices of the folded protein all exhibit preferences for helix-like conformations in solution. The conformational ensembles of the A-and D-helix peptides contain ordered helical forms, as shown by extensive series of medium-range nuclear Overhauser effect connectivities, while the B- and C-helix peptides exhibit conformational preferences for nascent helix. All four peptides adopt ordered helical conformations in mixtures of trifluoroethanol and water. The terminal and interconnecting loop peptides also appear to contain appreciable populations of conformers with backbone φ and ψ angles in the α-region and include highly populated hydrophobic cluster and/or turn conformations in some cases. Trifluoroethanol is unable to drive these peptides towards helical conformations. Overall, the peptide fragments of myohemerythrin have a marked preference towards secondary structure formation in aqueous solution. In contrast, peptide fragments derived from the β-sandwich protein plastocyanin are relatively devoid of secondary structure in aqueous solution (see accompanying paper). These results suggest that the two different protein structural motifs may require different propensities for formation of local elements of secondary structure to initiate folding, and that there is a prepartitioning of conformational space determined by the local amino acid sequence that is different for the helical and β-sandwich structural motifs.
Female rats are more susceptible to central nervous system oxygen toxicity than male rats

Tonic–clonic seizures typify central nervous system oxygen toxicity (CNS‐OT) in humans and animals exposed to high levels of oxygen, as are encountered during scuba diving. We previously demonstrated that high doses of pseudoephedrine (PSE) decrease the latency to seizure (LS) for CNS‐OT in young male rats. This study investigated whether female rats respond similarly to PSE and hyperbaric oxygen (HBO). We implanted 60 virgin stock (VS) and 54 former breeder (FB) female rats with radio‐telemetry devices that measured brain electrical activity. One week later, rats were gavaged with saline or PSE in saline (40, 80, 120, 160, or 320 mg/kg) before diving to five atmospheres absolute in 100% oxygen. The time between reaching maximum pressure and exhibiting seizure was LS. Vaginal smears identified estrus cycle phase. PSE did not decrease LS for VS or FB, primarily because they exhibited low LS for all conditions tested. VS had shorter LS than males at 0, 40, and 80 mg/kg (−42, −49, and −57%, respectively). FB also had shorter LS than males at 0, 40, and 80 mg/kg (−60, −86, and −73%, respectively). FB were older than VS (286 ± 10 days vs. 128 ± 5 days) and weighed more than VS (299 ± 2.7 g vs. 272 ± 2.1 g). Males tested were younger (88 ± 2 days), heavier (340 ± 4.5 g), and gained more weight postoperatively (7.2 ± 1.6 g) than either VS (−0.4 ± 1.5 g) or FB (−1.6 ± 1.5 g); however, LS correlated poorly with age, body mass, change in body mass, and estrus cycle phase. We hypothesize that differences in sex hormones underlie females' higher susceptibility to CNS‐OT than males.
Storage and retrieval in a paired-associate task

Ss were presented with uni- and bidirectional paired-associate tasks under conditions where they determined both storage and retrieval times. Storage time varies with list but not with item difficulty. Retrieval time of correct responses is independent of both list and item difficulty; retrieval times that are unsuccessful vary with item difficulty.
Three Measurement Problems

The aim of this essay is to distinguish and analyze several difficulties confronting attempts to reconcile the fundamental quantum mechanical dynamics with Born's rule. It is shown that many of the proposed accounts of measurement fail at least one of the problems. In particular, only collapse theories and hidden variables theories have a chance of succeeding, and, of the latter, the modal interpretations fail. Any real solution demands new physics.
Water and Nonelectrolyte Permeability of Lipid Bilayer Membranes

Both the permeability coefficients (Pd's) through lipid bilayer membranes of varying composition (lecithin [L], lecithin:cholesterol [LC], and spingomyelin:cholesterol [SC]) and the n-hexadecane:water partition coefficients (Knc's) of H2O and seven nonelectrolytes (1,6 hexanediol, 1,4 butanediol, n-butyramide, isobutyramide, acetamide, formamide, and urea) were measured. For a given membrane compositiin, Pd/DKnc (where D is the diffusion constant in water) is the same for most of the molecules tested. There is no extraordinary dependence of Pd on molecular weight; thus, given Pd(acetamide), Pd(1,6 hexanediol) is correctly predicted from the Knc and D values for the two molecules. The major exceptions are H2O, whose value of Pd/DKnc is about 10-fold larger, and urea, whose value is about 5-fold smaller than the general average. In a "tight" membrane such as SC, Pd(n-butyramide)/Pd(isobutyramide)=2.5; thus this bilayer manifests the same sort of discrimination between branched and straight chain molecules as occurs in many plasma membranes. Although the absolute values of the Pd's change by more than a factor of 100 in going from the tightest membrane (SC) to the loosest (L), the relative values remain approximately constant. The general conclusion of this study is that H2O and nonelectrolytes cross lipid bilayer membranes by a solubility-diffusion mechanism, and that the bilayer interior is much more like an oil (a la Overton) than a rubber-like polymer (a la Lieb and Stein).
Family communication about HIV/AIDS and sexual behaviour among senior secondary school students in Accra, Ghana.

Background: Sexually active adolescents in Ghana are increasingly at risk of HIV and other sexually transmitted infections. As a primary agent of socialization, the family can exert a strong influence on adolescent sexual behaviour. Therefore, to aid in the design and implementation of effective prevention programmes, it is important to understand the role of the family in influencing sexual behaviour among school-going adolescents. Objectives: To evaluate the relationship between family communications about HIV/AIDS and sexual activity and condom use among school-going adolescents in Accra, Ghana. Method: A sample of 894 students (56.9% girls, 43.1% boys; mean age = 17.4 years, SD = 1.40) at two senior secondary schools in Accra completed a modified version of the Youth Risk Behavior Survey (YRBS) questionnaire, a self-administered instrument developed by the Centers for Disease Control and Prevention. Analytical techniques utilized included logistic regression and chi-square. Results: Twenty-five percent of the participants reported being sexually experienced, and 73.6% had talked about HIV/AIDS with parents or other family members. Of the sexually experienced students, 64.7% initiated first sexual intercourse by age 16; and 55.7% did not use a condom at last sexual intercourse. Bivariate analysis showed significant gender differences in sexual activity, condom use, and family communication about HIV/AIDS. Logistic regression analysis showed that student-family communication about HIV/AIDS was not associated with sexual activity. However, communication about HIV/AIDS between students and parents or other family members increased the odds of using a condom at last sexual intercourse. Conclusions: The findings of this study suggest that prevention programmes that seek to educate Ghanaian school-going adolescents about sexual risk behaviour must strongly encourage communication about HIV/AIDS between students and family members. Key words: Ghana, adolescent health, risky sexual behaviour, condom use, gender differences. African Health Sciences 2003; 3(1): 7 - 14
Social Skills for Behaviorally Disordered Children as Preparation for Mainstreaming: Theory, Practice, and New Directions

Behaviorally disordered children experience social rejection in mainstreamed settings, and this conflicts with the goals of mainstreaming. A conceptual framework of social competence is presented, within which specific social skills are identified. The literature on social skills training is reviewed. Although social skills training holds promise for improving social competence, it fails to address the social perception biases of peers. It is argued that social perception biases help sustain negative peer relationships. Thus, addressing social perception biases in group social skills training interventions should improve the effectiveness of social skills training interventions, and the mainstreamed experiences of behaviorally disordered children should be more successful.
Nonlinear reconfiguration for asymmetric failures in a six degree-of-freedom F-16

We consider an F-16 fighter aircraft subject to asymmetric actuator failures. To address non-symmetric faults, it is not possible to decouple the longitudinal and lateral dynamics. It is necessary to deal with a full six degree of freedom airframe. Firstly, we outline an automated procedure to assemble the symbolic and simulation models of complex aircraft. The symbolic model can be manipulated in various ways and used for both linear and nonlinear control system design. In the event of actuator failures, the failed surfaces not only cease to function as viable inputs but also impose persistent disturbances on the system. As previously shown, the problem of designing a reconfigured controller can be formulated as a nonlinear disturbance rejection problem. We apply this method to design a controller for the F-16.
Radiographic examination of the small bowel: survey of practice patterns in the United States.

PURPOSE: To obtain understanding of the current practice patterns of academic and private radiology groups in the United States in radiographic examination of the small bowel. MATERIALS AND METHODS: The survey consisted of questions about small-bowel follow-through (SBFT) examinations, including frequency of overhead radiographs, use of fluoroscopic spot images, personnel performing fluoroscopy, practice settings, and degree of specialization. By using a standard sampling technique, the country was divided into nine regions, and one state from each region was randomly selected. The survey was mailed to 452 full-time chief technologists. The responses were tabulated, and statistical analysis of the data was performed with the χ2 test. RESULTS: Completed questionnaires were returned by 236 (52%) of 452 chief technologists; 219 (93%) respondents, 176 (80%) in private and 43 (20%) in academic groups, indicated that their group performed SBFT studies. The studies were performed by general radiologists in 205 (...
Phosphoglucomutase of Yersinia pestis is required for autoaggregation and polymyxin B resistance.

Yersinia pestis, the causative agent of plague, autoaggregates within a few minutes of cessation of shaking when grown at 28°C. To identify the autoaggregation factor of Y. pestis, we performed mariner-based transposon mutagenesis. Autoaggregation-defective mutants from three different pools were identified, each with a transposon insertion at a different position within the gene encoding phosphoglucomutase (pgmA; y1258). Targeted deletion of pgmA in Y. pestis KIM5 also resulted in loss of autoaggregation. Given the previously defined role for phosphoglucomutase in antimicrobial peptide resistance in other organisms, we tested the KIM5 pgmA mutant for antimicrobial peptide sensitivity. The pgmA mutant displayed >1,000-fold increased sensitivity to polymyxin B compared to the parental Y. pestis strain, KIM5. This sensitivity is not due to changes in lipopolysaccharide (LPS) since the LPSs from both Y. pestis KIM5 and the pgmA mutant are identical based on a comparison of their structures by mass spectrometry (MS), tandem MS, and nuclear magnetic resonance analyses. Furthermore, the ability of polymyxin B to neutralize LPS toxicity was identical for LPS purified from both KIM5 and the pgmA mutant. Our results indicate that increased polymyxin B sensitivity of the pgmA mutant is due to changes in surface structures other than LPS. Experiments with mice via the intravenous and intranasal routes did not demonstrate any virulence defect for the pgmA mutant, nor was flea colonization or blockage affected. Our findings suggest that the activity of PgmA results in modification and/or elaboration of a surface component of Y. pestis responsible for autoaggregation and polymyxin B resistance.
Estimate of the Mutation Rate per Nucleotide in Humans

Many previous estimates of the mutation rate in humans have relied on screens of visible mutants. We investigated the rate and pattern of mutations at the nucleotide level by comparing pseudogenes in humans and chimpanzees to (i) provide an estimate of the average mutation rate per nucleotide, (ii) assess heterogeneity of mutation rate at different sites and for different types of mutations, (iii) test the hypothesis that the X chromosome has a lower mutation rate than autosomes, and (iv) estimate the deleterious mutation rate. Eighteen processed pseudogenes were sequenced, including 12 on autosomes and 6 on the X chromosome. The average mutation rate was estimated to be approximately 2.5 x 10(-8) mutations per nucleotide site or 175 mutations per diploid genome per generation. Rates of mutation for both transitions and transversions at CpG dinucleotides are one order of magnitude higher than mutation rates at other sites. Single nucleotide substitutions are 10 times more frequent than length mutations. Comparison of rates of evolution for X-linked and autosomal pseudogenes suggests that the male mutation rate is 4 times the female mutation rate, but provides no evidence for a reduction in mutation rate that is specific to the X chromosome. Using conservative calculations of the proportion of the genome subject to purifying selection, we estimate that the genomic deleterious mutation rate (U) is at least 3. This high rate is difficult to reconcile with multiplicative fitness effects of individual mutations and suggests that synergistic epistasis among harmful mutations may be common.
Practicing anthropology on a community-based public health coalition: lessons from heal.

The author has served on the north Portland Healthy Eating Active Living Coalition since 2008. HEAL is a community-based health promotion program whose goal is to reduce and prevent childhood obesity in a predominantly Hispanic community. The author's role on the coalition is to conduct evaluation research and assist the coalition in identifying and addressing assets and barriers in the physical and social environment of this community so that children and their families have improved access to healthy food and recreation. Coalition work provides important opportunities for anthropologists to engage in community projects, and can help academic anthropologists develop collaborative research opportunities. Anthropologists can bring assets to such coalitions, including participatory research skills and familiarity with mediation. The time commitment and pace of community work can pose challenges for anthropologists who balance coalition work with other applied projects and academic positions. The methodology and focus of community-based work can also provide challenges for anthropologists, especially in publishing the findings and outcomes of their work. Finally, the participation of anthropologists on coalitions could be enhanced by additional graduate and postgraduate training in evaluation research, grant writing, and fiscal management.
Lightweight, wideband, amplitude-tapered, linearly-polarized, dual-axis monopulse, ku-band patch antenna array for SAR

This paper reports a new lightweight, amplitude-tapered, wideband, linearly-polarized, dual-axis monopulse passive antenna array for synthetic aperture radar (SAR) applications. The 16 times 16 element patch array aperture is 197.7 cm2 (140.61 mm from antenna edge to antenna edge in both orthogonal directions). The array is 2.98 mm thick and provides 17% instantaneous bandwidth in Ku-band. It is easily manufactured using photolithographic etching techniques.
Fractionally spaced blind equalization and estimation of FIR channels

The author considers the problem of blind estimation and equalization of digital communication FIR (finite impulse response) channels using fractionally spaced samples. The problem is cast in a mathematical framework of parameter estimation for a vector stationary process with a single input (information sequence) and multiple outputs, by using a time-series representation of a cyclostationary process. The channel parameters are estimated by nonlinear batch optimization of a quadratic cumulant matching criterion involving second and fourth order cumulants of the received data. A new algorithm is proposed for (asymptotically) globally convergent, linear estimation of the FIR channel parameters where the FIR model order is not necessarily known. A simulation example using QAM (quadrature amplitude modulation) signals is presented. >
Heavy metal concentrations in Juan Fernández fur seals (Arctocephalus philippii)

Abstract During 1992, mercury, cadmium and lead concentrations were determined from livers of Juan Fernandez fur seals (27 pups, one subadult, and one adult) found dead at Alejandro Selkirk Island, Chile. In pups, concentrations of mercury, cadmium and lead averaged 9.33 mg kg−1 (SD = 6.56), 0.51 mg kg−1 (SD = 0.19) and 0.47 mg kg−1 (SD = 0.43), respectively. In the subadult and adult, concentrations of mercury were 27.29 and 75.09 mg/kg; of cadmium 1.66 and 1.57 mg kg−1; and of lead 0.07 and 1.37 mg kg−1, respectively. Possible sources of contamination with these metals are discussed.
Evaluation of the acute effects of distal coronary microembolization using multidetector computed tomography and magnetic resonance imaging.

The purpose of this study was to test the potential of clinical imaging modalities, 64-slice multidetector computed tomography (MDCT) and 1.5T magnetic resonance imaging (MRI) for qualitative and quantitative evaluation of acute microinfarcts and to determine the effects of <120 μm microemboli on left ventricular function, perfusion, cardiac injury biomarkers, arrhythmia, and cellular and vascular structures. Under X-ray fluoroscopy, 40–120 μm (16 mm3) microemboli were delivered to embolize the left anterior descending (LAD) coronary artery of nine pigs. MDCT/MRI were performed at 72 h in a single session. Microinfarcts were visible in six of nine animals on delayed contrast-enhanced MDCT/MR images but measurable in all animals using semiautomated threshold methods. Other MDCT and MRI sequences demonstrated decline in left ventricular ejection fraction, regional strain and perfusion in visible and invisible microinfarcted regions. Microemboli caused significant elevation in cardiac injury enzymes and arrhythmias. Various sizes of microinfarcts appeared microscopically as distinct aggregates of macrophages replacing myocardium. Semiautomated threshold methods are necessary to measure and confirm/deny the presence of myocardial microinfarcts. This study offers support for alternative applications of MDCT/MRI in assessing clinical cases in which microemboli <120 μm escape protective devices during percutaneous coronary interventions. Although microembolization resulted in no mortality, it caused left ventricular dysfunction, perfusion deficit, cellular damage increase in cardiac injury enzymes, and arrhythmias. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
The significance of recalcitrant emotion (or, anti-quasijudgmentalism)

Sentimentalist theories in ethics treat evaluative judgments as somehow dependent on human emotional capacities. While the precise nature of this dependence varies, the general idea is that evaluative concepts are to be understood by way of more basic emotional reactions. Part of the task of distinguishing between the concepts that sentimentalism proposes to explicate, then, is to identify a suitably wide range of associated emotions. In this paper, we attempt to deal with an important obstacle to such views, which arises from the dominant tradition in the philosophy of emotion. We will be attempting to steer a middle course between the traditional view and some recent, empirically-minded criticism.
The Current Transition Reconsidered

This volume has presented collected essays on various aspects of the current transformation of industrial capitalism in an attempt to create a single complete picture. The book touched upon five dimensions of the current transformation of capitalism: technology, labor relations, firm organization, public policy, and locational decisionmaking. The purpose of this final chapter is to summarize the debate contained within the book and to extend the findings beyond the narrow confines of the largely Anglo-American and U.K. experience that the authors present.
From Structured Prediction to Inverse Reinforcement Learning

Machine learning is all about making predictions; language is full of complex rich structure. Structured prediction marries these two. However, structured prediction isn’t always enough: sometimes the world throws even more complex data at us, and we need reinforcement learning techniques. This tutorial is all about the how and the why of structured prediction and inverse reinforcement learning (aka inverse optimal control): participants should walk away comfortable that they could implement many structured prediction and IRL algorithms, and have a sense of which ones might work for which problems.
Material Parameters for Life Prediction in Ceramics

A detailed experimental study of critical material parameters needed for life prediction methodology in hot-pressed silicon nitride, NC132, has been made. The primary experimental techniques were double torsion and indentation induced flaw methods to determine the relationship between crack velocity, V, and stress intensity, K, during subcritical crack growth.
Anger inhibition potentiates the association of high end-tidal CO2 with blood pressure in women.

Objective High resting end-tidal CO2 (PetCO2) has been shown to be an independent predictor of systolic blood pressure (SBP) in women, particularly older women. The study reported in this article investigated whether the tendency to experience, express, and/or suppress anger contributes to the association of PetCO2 and SBP in women and in men. Methods The Spielberger Anger Expression Inventory was administered to 403 healthy male and female participants in the Baltimore Longitudinal Study on Aging. Resting PetCO2 was obtained by means of a respiratory gas monitor, and resting blood pressure was obtained with an oscillometric device. The associations of resting PetCO2 and the anger scales with SBP and diastolic blood pressure (DBP) were investigated using multivariate regression analyses. Results PetCO2, as well as age and body mass index, was an independent predictor of SBP in women with low, but not high, trait anger and in women with low, but not high, anger-out. PetCO2 was not an independent predictor of SBP in men with either high or low anger. In addition, PetCO2 was not an independent predictor of DBP in either men or women. Conclusions The results of this study indicate that inhibition of anger potentiates the relationship of high PetCO2 with SBP in women but not men. Additional studies are needed to determine the origins of the observed gender differences and the psychophysiological pathways by which high resting PetCO2 contributes to elevated resting blood pressure in women.
Life meaning following combat among air force security forces personnel

An active duty Air Force ground combat unit (n = 189) completed surveys about trauma and combat exposure, mood symptoms, and meaning in life. Two dimensions of deployment-related traumas were asses...
Some LCPs solvable in strongly polynomial time with Lemke's algorithm

We identify a class of Linear Complementarity Problems (LCPs) that are solvable in strongly polynomial time by Lemke's Algorithm (Scheme 1) or by the Parametric Principal Pivoting Method (PPPM). This algorithmic feature for the class of problems under consideration here is attributable to the proper selection of the covering vector in Scheme 1 or the parametric direction vector in the PPPM which leads to solutions of limited and monotonically increasing support size; such solutions are sparse. These and other LCPs may very well have multiple solutions, many of which are unattainable by either algorithm and thus are said to be elusive. The initial conditions imposed on the new matrix class identified in Sect. 2 are subsequently relaxed in later sections.