The design of a line velocity interferometer for any reflector for inertial confinement experiments on the Z-machine

A line VISAR (Velocity Interferometer System for Any Reflector) has been designed and commissioned at the Sandia National Laboratory's Z-machine. The instrument consists of an F/2 collection system, beam transport, and an interferometer table that contains two Mach-Zehnder type interferometers and an eight channel Gated Optical Imaging (GOI) system. The VISAR probe laser operates at the 532 nm wavelength, and the GOI bandpass is 540-600 nm. The output of each interferometer is passed to an optical streak camera with four selectable sweep speeds. The system is designed with three interchangeable optics modules to select a full field of view of 1 mm, 2 mm, or 4 mm. The optical beam transport system connects the target image plane to the interferometers and the gated optical imagers. The target is integrated into a sacrificial final optics assembly that is integral to the transport beamline.

Exploration of methods for lamb carcass yield estimation in Canada

Different approaches were evaluated to improve the accuracy of carcass yield predictions of Canadian lamb carcasses using manually obtained measurements and dual-energy X-ray absorptiometry (DEXA). Several linear carcass measurements were obtained from a population of commercial lamb carcasses representative of the variability in Canadian slaughter plants (n = 155). Carcass measures were categorized into four sets according to when each measure could be obtained in the slaughter process. Each set of carcass measurements were subjected to stepwise regression and used to develop models for the estimation of lean meat and saleable yield percentages. Tissue depth measures (at the GR site) explained 44% of variation in lean meat yield in hot carcasses and 53% in cold carcasses. When additional parameters were included with cold GR, the regression model explained 61.9% of the variability in lean meat yield. Saleable yield predictions were less accurate (R2 < 0.40); the greatest degree of variability was predicted when the model included ribeye area (R2 = 0.39). The DEXA scans obtained on carcass sides were able to predict about 78% of variability in carcass lean meat yield and 91% of fat content. This information could be used by the lamb meat industry to establish new carcass classification systems based on more accurate lean meat yield values.

Guaranteeing Canadian lamb meat quality using near-infrared spectroscopy on intact rack

Lamb racks from commercial carcasses were scanned using near-infrared spectroscopy. The prediction accuracies (R2) for meat quality traits were assessed. Prediction accuracy ranged between 0.40 and 0.94. When predicted values were used to classify meat based on quality, 88.7%–95.2% of samples were correctly classified as quality guaranteed.

Nitrite Embedded Vacuum Packaging Improves Retail Color and Oxidative Stability of Bison Steaks and Patties

Bison meat is prone to rapid discoloration under traditional aerobic retail packaging conditions. The aim of this study was to determine if the color stability of bison steaks and burger patties could be improved through packaging meat with a vacuum-sealed film containing embedded sodium nitrite. Bison bulls (n = 40) were slaughtered and the longissimus lumborum (LL) and rhomboideus (RH) were removed. Following a postmortem aging period of 6, 13, or 20 d steaks were obtained from the LL. RH muscles aged 6 d were ground (85:15 lean to fat) and formed into 140 g patties. One steak and two burger patties from each carcass side were placed into either a polystyrene tray overwrapped with oxygen permeable polyvinyl chloride film (CONT) or a polyethylene tray vacuum sealed with film coated in sodium nitrite (113 mg × m–2; NIT); meat was placed under simulated retail conditions for 4 d. A 3-way interaction was observed between packaging type, whole muscle aging and time in retail display for objective (L*, Chroma, and Hue) and subjective (lean color score and proportion of surface discoloration) color measures from steaks (P < 0.0001). The CONT packaged meat showed an increased area of discoloration and in metmyoglobin after 4 d in retail display (P < 0.0001); NIT meats did not show a higher area of discoloration or metmyoglobin after retail display. Additionally, NIT packaged steaks and burger patties lightened (higher L*) and became redder over the course of the retail display period. Thiobarbituric acid reactive substances (products of lipid peroxidation) did not increase in NIT packaged burger patties after 4 d under retail conditions, however, there was a significant increase observed for CONT packaged burger patties (P < 0.0001). NIT packaging appears to effectively improve the color stability of bison meat under retail conditions, making this packaging strategy well suited to address the issue of rapid discoloration.

Application of psychosocial models to Home-Based Testing and Counseling (HBTC) for increased uptake and household coverage in a large informal urban settlement in Kenya

INTRODUCTION

Home Based Testing and Counselling (HBTC) aims at reaching individuals who have low HIV risk perception and experience barriers which prevent them from seeking HIV testing and counseling (HTC) services. Saturating the community with HTC is needed to achieve the ambitious 90-90-90 targets of knowledge of HIV status, ARV treatment and viral suppression. This paper describes the use of health belief model and community participation principles in HBTC to achieve increased household coverage and HTC uptake.

METHODS

This cross sectional survey was done between August 2009 and April 2011 in Kibera slums, Nairobi city. Using three community participation principles; defining and mobilizing the community, involving the community, overcoming barriers and respect to cultural differences and four constructs of the health belief model; risk perception, perceived severity, perceived benefits of changed behavior and perceived barriers; we offered HTC services to the participants. Descriptive statistics were used to describe socio-demographic characteristics, calculate uptake and HIV prevalence.

RESULTS

There were 72,577 individuals enumerated at the start of the program; 75,141 residents were found during service delivery. Of those, 71,925 (95.7%) consented to participate, out of which 71,720 (99.7%) took the HIV test. First time testers were (39%). The HIV prevalence was higher (6.4%) among repeat testers than first time testers (4.0%) with more women (7.4%) testing positive than men (3.6%) and an overall 5.5% slum prevalence.

CONCLUSION

This methodology demonstrates that the use of community participation principles combined with a psychosocial model achieved high HTC uptake, coverage and diagnosed HIV in individuals who believed they are HIV free. This novel approach provides baseline for measuring HTC coverage in a community.

Simulated performance of the optical Thomson scattering diagnostic designed for the National Ignition Facility

An optical Thomson scattering diagnostic has been designed for the National Ignition Facility to characterize under-dense plasmas. We report on the design of the system and the expected performance for different target configurations. The diagnostic is designed to spatially and temporally resolve the Thomson scattered light from laser driven targets. The diagnostic will collect scattered light from a 50 × 50 × 200 μm volume. The optical design allows operation with different probe laser wavelengths. A deep-UV probe beam (λ₀ = 210 nm) will be used to Thomson scatter from electron plasma densities of ∼5 × 10²⁰ cm^-3 while a 3ω probe will be used for plasma densities of ∼1 × 10¹⁹ cm^-3. The diagnostic package contains two spectrometers: the first to resolve Thomson scattering from ion acoustic wave fluctuations and the second to resolve scattering from electron plasma wave fluctuations. Expected signal levels relative to background will be presented for typical target configurations (hohlraums and a planar foil).

The design of the optical Thomson scattering diagnostic for the National Ignition Facility

The National Ignition Facility (NIF) is a 192 laser beam facility designed to support the Stockpile Stewardship, High Energy Density and Inertial Confinement Fusion (ICF) programs. We report on the design of an Optical Thomson Scattering (OTS) diagnostic that has the potential to transform the community's understanding of NIF hohlraum physics by providing first principle, local, time-resolved measurements of under-dense plasma conditions. The system design allows operation with different probe laser wavelengths by manual selection of the appropriate beam splitter and gratings before the shot. A deep-UV probe beam (λ₀-210 nm) will be used to optimize the scattered signal for plasma densities of 5 × 10²⁰ electrons/cm³ while a 3ω probe will be used for experiments investigating lower density plasmas of 1 × 10¹⁹ electrons/cm³. We report the phase I design of a two phase design strategy. Phase I includes the OTS telescope, spectrometer, and streak camera; these will be used to assess the background levels at NIF. Phase II will include the design and installation of a probe laser.

Effects of electrical stimulation on meat quality of bison striploin steaks and ground patties

As bison is characteristically dark in colour, this study was conducted to determine if high-voltage electrical stimulation (HVES) could improve the colour and other quality characteristics in bison, similar to positive effects of HVES previously observed in beef. Forty bison bull carcasses were split and HVES (400 V peak, 5 ms pulses at 15 pulses s−1 for 30 s) was applied to the right sides and subsequently evaluated for grade characteristics, metabolic activity, and quality characteristics. The bison carcasses used in this study had a wide range of lean and fat, with minimal marbling. In the present study, HVES had no effect on bison quality traits, sensory attributes, retail display characteristics, nor the glycolytic metabolites (P > 0.05) except lactate. Inherent differences in muscle fibre type or physical carcass differences may have influenced the response to the electrical parameters used in the present study and merits further investigation.

Clinical beak and feather disease virus infection in wild juvenile eastern rosellas of New Zealand; biosecurity implications for wildlife care facilities

CASE HISTORY

Four juvenile eastern rosellas (Platycercus eximius) were admitted to two separate wildlife care facilities in the Auckland region by members of the public. They had missing or dystrophic wing and tail feathers that rendered them flightless, suggestive of beak and feather disease virus (BFDV) infection. Two were subject to euthanasia after failing to re-grow their feathers, with samples taken for histopathology and PCR analysis. Blood samples were obtained from the other two birds at the time of examination, however these individuals were lost to follow up.

PATHOLOGICAL AND MOLECULAR FINDINGS

Basophilic inclusion bodies were observed in histological sections of the feather bulb, typical of BFDV infection, from the two euthanised individuals. Blood from all four birds tested positive by PCR for BFDV, and analysis of the recovered full BFDV genomes identified them as belonging to the BFDV-A strain.

DIAGNOSIS

Beak and feather disease virus infection.

CLINICAL RELEVANCE

This report highlights the clinical impacts of BFDV in juvenile eastern rosellas that may result in their admission to wildlife care facilities, creating a biosecurity risk in institutions that may host other native parrots intended for release. The environmental stability of BFDV and resistance to disinfection requires strict quarantine procedures to prevent contamination and spread within a facility. It is recommended that high-risk species such as wild eastern rosella be excluded from facilities that may also house native parrots.

The relation of carcass physiological maturity to meat quality in the Canadian Bison Grading System

López-Campos, Ó., Aalhus, J. L., Galbraith, J., Larsen, I. L., Juárez, M., Uttaro, B. and Robertson, W. M. 2014. The relation of carcass physiological maturity to meat quality in the Canadian Bison Grading System. Can. J. Anim. Sci. 94: 55–62. A total of 119 bull (n=62) and heifer (n=57) bison carcasses were selected to determine the effectiveness of youthful to intermediate physiological maturity [ossification at the 9th/10th/11th thoracic spinous processes (≤50%; 51–65%; 66–80%)] range to accurately classify bison carcasses with respect to quality. Carcasses were classified into three maturity groups according to ossification at the 9th/10th/11th thoracic spinous processes (≤50%; 51–65%; 66–80%). Carcass, meat quality and sensory evaluation data were then collected. Bull carcasses were significantly (P<0.0001) heavier than heifers (308.0 vs. 228.6 kg), while heifers had higher (P<0.0001) marbling scores than bulls (368 vs. 289). For both genders, ossification group had little or no impact (P>0.05) on any of the meat quality traits. Gender had an impact on the shear force values for both fresh (P<0.0001) and frozen/thawed (P=0.0002) samples, with bulls having higher values than heifers. Panellists detected differences between heifers and bulls in initial tenderness (P<0.0001; 7.11 vs. 6.27), flavour intensity (P=0.005; 5.40 vs. 5.14), amount of connective tissue (P=0.0002; 7.64 vs. 7.18), and overall tenderness (P=0.003; 7.13 vs. 6.50). Only initial juiciness was significantly affected (P=0.02) by the ossification group (5.38, 5.64 and 5.76). A gender×ossification group interaction was also detected for flavour intensity (P=0.004) and off-flavour intensity (P=0.03), but the magnitudes of the differences were in the order of one-half panel unit or less, generally below the detection of most consumers. The range of physiological maturity studied had limited effects on meat quality and support the elimination of an intermediate physiological maturity grade (51–80% ossification) from the Canadian Bison Grading System.

Lack of knowledge of HIV status a major barrier to HIV prevention, care and treatment efforts in Kenya: results from a nationally representative study

BACKGROUND

We analyzed HIV testing rates, prevalence of undiagnosed HIV, and predictors of testing in the Kenya AIDS Indicator Survey (KAIS) 2007.

METHODS

KAIS was a nationally representative sero-survey that included demographic and behavioral indicators and testing for HIV, HSV-2, syphilis, and CD4 cell counts in the population aged 15-64 years. We used gender-specific multivariable regression models to identify factors independently associated with HIV testing in sexually active persons.

RESULTS

Of 19,840 eligible persons, 80% consented to interviews and blood specimen collection. National HIV prevalence was 7.1% (95% CI 6.5-7.7). Among ever sexually active persons, 27.4% (95% CI 25.6-29.2) of men and 44.2% (95% CI 42.5-46.0) of women reported previous HIV testing. Among HIV-infected persons, 83.6% (95% CI 76.2-91.0) were unaware of their HIV infection. Among sexually active women aged 15-49 years, 48.7% (95% CI 46.8-50.6) had their last HIV test during antenatal care (ANC). In multivariable analyses, the adjusted odds ratio (AOR) for ever HIV testing in women ≥35 versus 15-19 years was 0.2 (95% CI: 0.1-0.3; p<0.0001). Other independent associations with ever HIV testing included urban residence (AOR 1.6, 95% CI: 1.2-2.0; p = 0.0005, women only), highest wealth index versus the four lower quintiles combined (AOR 1.8, 95% CI: 1.3-2.5; p = 0.0006, men only), and an increasing testing trend with higher levels of education. Missed opportunities for testing were identified during general or pregnancy-specific contacts with health facilities; 89% of adults said they would participate in home-based HIV testing.

CONCLUSIONS

The vast majority of HIV-infected persons in Kenya are unaware of their HIV status, posing a major barrier to HIV prevention, care and treatment efforts. New approaches to HIV testing provision and education, including home-based testing, may increase coverage. Targeted interventions should involve sexually active men, sexually active women without access to ANC, and rural and disadvantaged populations.

Identifying individual scaffolding molecules in the postsynaptic density

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 - August 7, 2008.

Dynamic association between parental monitoring and communication and adolescent risk involvement among African-American adolescents

PURPOSE

To examine: (1) the relationship between parental monitoring and communication and adolescent risk involvement over time, including consideration of their potential interaction; and (2) the effect of consistent versus inconsistent monitoring and communication over time on adolescent risk behaviors.

METHODS

Baseline and follow-up data were collected from 1999-2003. A total of 817 African-American adolescents and their parents were recruited from 35 low-income urban communities in Baltimore, MD. Perceived parental monitoring, parent-adolescent communication and seven risk behaviors were assessed. Logistic general estimating equation (GEE) models were performed to assess the dynamic association.

RESULTS

Perceived parental monitoring had protective effects on concurrent adolescent risk involvement over two-year observation. The protective effect on girls' sexual abstinence increased significantly over time. Perceived problem communication was associated with increased risk of concurrent involvement in violent behaviors, but the effect did not change over time. For girls, the probability of engaging in sex increased greatly (from 0.3 to 0.6) for those who perceived problem communication, while it remained stable (about 0.4) for those perceiving less problem communication.

CONCLUSIONS

The data confirm the protective effect of perceived parental monitoring on adolescent risk involvement. It also extends previous findings by showing the importance of consistent parental monitoring and communication.

Parental awareness of adolescent risk involvement: implications of overestimates and underestimates

PURPOSE

To explore: 1) parent-adolescent discrepancies on adolescent risk involvement; 2) factors related to parental overestimates and/or underestimates of specific adolescent risk behaviors; and 3) the association of parental overestimates and/or underestimates at baseline with subsequent adolescent risk involvement.

METHODS

754 African American parent-adolescent dyads were recruited from 35 low-income urban communities in Baltimore, Maryland. Parent-adolescent discordance (overestimates and underestimates) regarding adolescent involvement in risk behaviors in three areas (sex, substance use, and violence) were assessed. Multiple logistic regression models were performed to examine the association of parental overestimates or underestimates with subsequent adolescent risk involvement, and to explore potential factors related to parental overestimates and underestimates of each behavior.

RESULTS

Percentage of parental overestimation and underestimation ranged from 3% to 24% and 53% to 86%, respectively, for targeted behaviors. Parents reporting higher levels of parental monitoring and open communication were less likely to overestimate, and more likely to underestimate adolescent risk involvement. Parents of adolescents who perceived themselves as better than average in school performance and who participated in religious services were more likely to underestimate adolescents' substance use and sex. Parents of older adolescents overestimated adolescents' sexual experience. Parental overestimation at baseline generally predicted subsequent increased risk of adolescents engaging in these behaviors. Conversely, parental underestimation was associated with subsequent decreased adolescent risk involvement.

CONCLUSIONS

Parental underestimation and overestimation of adolescent risk involvement have implications for subsequent adolescent risk involvement. The protective association of parental underestimation and the adverse association of parental overestimation on subsequent adolescent risk involvement indicate that parenting interventions should advance beyond simply improving parent-adolescent concordance on risk behavior.

Trial of an urban adolescent sexual risk-reduction intervention for rural youth: a promising but imperfect fit

PURPOSE

The purpose of this study was to assess the effectiveness of Focus on Kids (FOK), a sexual risk reduction intervention, shown to be effective among urban, African-American adolescents living in communities with high rates of sexually transmitted diseases, in reducing sexual risk behaviors among rural, white adolescents living in communities with low rates of sexually transmitted diseases. The subjects were 1,131 youth ages 12 to 16 years from 12 rural counties in West Virginia.

METHOD

The study was a randomized, controlled, longitudinal trial of a theory-based prevention intervention. Outcomes included self-reported sexual behaviors and perceptions assessed at baseline and at 3, 6, and 9 months after intervention.

RESULTS

At baseline, 21% of youth were sexually experienced; 80% reported using a condom at last episode of intercourse. Rates of behaviors did not differ based on intervention assignment (FOK vs control group) after adjusting for baseline differences at any follow-up period among the full cohort or among the subset of youth who completed the intervention curriculum to which they were assigned. Perceptions of risk and protective behaviors were positively influenced by FOK at 3, 6, and 9 months in a fashion consistent with the guiding model of behavioral change and the FOK curriculum.

CONCLUSIONS

Consistent with previous studies of FOK in high-risk urban areas, some perceptions were positively altered by FOK in these rural areas, although many of these changes did not persist through 9 months of follow-up. In contrast to previous studies, self-reported sexual risk behaviors did not decrease among FOK youth. FOK was not associated with any increases in sexual risk behaviors.

The complex business of adapting effective interventions to new populations: an urban to rural transfer

PURPOSE

To assess the effectiveness of a relatively unaltered version of a sexual risk reduction intervention previously shown to be effective among urban youth, "Original Focus on Kids" (OFOK), compared with a version modified for West Virginia (WVFOK) and a control condition (training in environmental conservation), in altering protective sexual behaviors and perceptions among rural, Appalachian youth.

SUBJECTS

Nine hundred ninety-nine youth aged 12 to 16 years from 12 rural counties in West Virginia.

METHOD

Randomized, controlled, longitudinal trial of a theory-based prevention intervention. Outcomes were self-reported sexual behaviors and perceptions assessed at baseline, 3, 6, and 9 months postintervention.

RESULTS

Both WVFOK and OFOK positively affected perceptions of abstinence but not behaviors. OFOK significantly enhanced some perceptions of condom use compared with both control youth and WVFOK youth, but again, not behaviors.

CONCLUSIONS

Overall, neither version was as effective as FOK had been in the original urban setting. The less altered version (OFOK) was more effective, especially with regard to condom-use perceptions, in this new population and cultural setting than the more culturally altered version (WVFOK). In several of the implementation settings, neither version was delivered as intended by the researchers because of logistic issues. Although many of these changes were seemingly minor, such deviations may have significant impact on intervention effect.

Protection Motivation Theory and Adolescent Drug Trafficking: Relationship Between Health Motivation and Longitudinal Risk Involvement

OBJECTIVE

To assess health protection motivation as explained by the constructs of protection motivation theory (PMT) and its association with drug trafficking over 2 years.

METHODS

The sample included 817 African American youth (13-16 years old) participating in an adolescent risk-reduction program. We developed an instrument measuring the level of health protection motivation (LHPM) using factor analysis. Changes in LHPM over time were examined among drug traffickers, abstainers, initiators, and nonrisk youths.

RESULTS

In sum, 151 participants reported selling and/or delivering drugs during the study period. The significant inverse correlation between drug-trafficking intention and health protection motivation was consistent with PMT. Changes in LHPM were strongly associated with the dynamics of behavior over 2 years.

CONCLUSIONS

Adolescent drug trafficking can be predicted by an overall level of health protection motivation. PMT and related theories should be considered in the design of drug-trafficking prevention intervention.

Influence of prior sexual risk experience on response to intervention targeting multiple risk behaviors among adolescents

PURPOSE

To identify correlates of sexual risk variations among African-American adolescents, and to examine the influence of prior sexual experience on response to a HIV risk-reduction intervention.

METHODS

Eight hundred seventeen African-American youth aged 13 to 16 years living in and around urban public housing in Baltimore were recruited to participate in a HIV risk-reduction intervention targeting multiple risk behaviors. An instrument designed to measure three levels of sexual risk ("abstinent," "protected sex" [having sex with a condom], and "unprotected sex" [having sex without a condom]) was administered at baseline, 6 months and 12 months postintervention. Multiple regression analyses were conducted to identify predictors of the degree of sexual risk using longitudinal data. Repeated measure analyses were conducted to assess behavioral changes over time among the three groups.

RESULTS

Data confirmed the co-variation of sexual risk behavior and other problem behaviors among adolescents, cross-sectionally and longitudinally. After exposure to an 8-session risk-reduction intervention, youth engaging in the highest degree of sexual risk demonstrated the greatest reduction in both sexual risk and other risks. These improvements were seen at both 6 months and 12 months postintervention. Youth who were abstinent at baseline maintained the lowest levels in risk involvement throughout the study period when compared with sexually active youth. However, abstinent youth risk involvement significantly increased at 6 months and 12 months after baseline. Youth engaging in protected sex at baseline demonstrated a significant increase in non-condom use and a significant decrease in multiple risk involvement over time.

CONCLUSIONS

Results support HIV risk-reduction intervention efforts that target multiple risk behaviors. Response of adolescents to the intervention is directly related to the sexual risk behavior at baseline. These data may suggest that the response to risk behavior intervention depends in part on the risk behavior profile of the population to which it is being applied.

Randomized trial of a parent intervention: parents can make a difference in long-term adolescent risk behaviors, perceptions, and knowledge

BACKGROUND

Although numerous interventions have been demonstrated to reduce targeted adolescent risk behaviors for brief periods, sustained behavior changes covering multiple risk behaviors have been elusive.

OBJECTIVE

To determine whether a parental monitoring intervention (Informed Parents and Children Together [ImPACT]) with and without boosters can further reduce adolescent truancy, substance abuse, and sexual risk behaviors and can alter related perceptions 24 months after intervention among youth who have all received an adolescent risk-reduction intervention, Focus on Kids (FOK).

DESIGN

Randomized, controlled, 3-celled longitudinal trial.

SETTING

Thirty-five low-income, urban community sites.

PARTICIPANTS

Eight hundred seventeen African American youth aged 13 to 16 at baseline. Intervention All youth participated in FOK, an 8-session, theory-based, small group, face-to-face risk-reduction intervention, 496 youth and parents received the 1-session ImPACT intervention (a videotape and discussion), 238 of the ImPACT youth also received four 90-minute FOK boosters delivered in small groups.

MAIN OUTCOME MEASURES

Responses at baseline and 24 months after intervention to a questionnaire assessing risk and protective behaviors and perceptions. Analyses used General Linear Modeling, intraclass correlation coefficient, analysis of covariance, and multiple comparisons with least significant difference test adjustment.

RESULTS

After adjusting for the intraclass correlation coefficient, 6 of 16 risk behaviors were significantly reduced (P< or =.05) among youth receiving ImPACT compared with youth who only received FOK (respectively, mean number of days suspended, 0.65 vs 1.17; carry a bat as a weapon, 4.1% vs 9.6%; smoked cigarettes, 12.5% vs 22.7%; used marijuana, 18.3% vs 26.8%; used other illicit drugs, 1.4% vs 5.6%; and, asked sexual partner if condom always used, 77.9% vs 64.9%). Four of the 7 theory-based subscales reflected significant protective changes among youth who received ImPACT. ImPACT did not produce any significant adverse effects on behaviors or perceptions.

CONCLUSION

A parent monitoring intervention can significantly broaden and sustain protection beyond that conferred through an adolescent risk-reduction intervention.

Effect of aminophylline on metabolic and thermoregulatory responses during hypothermia associated with cold exposure in lambs

Three experiments were conducted with lambs to test the hypothesis that the phosphodiesterase inhibitor/adenosine blocker, aminophylline would enhance metabolic rate and delay the development of hypothermia. In exp. 1, eight lambs were treated either with aminophylline or control (0.9% saline) injections. During hypothermia, metabolic rate was increased from a resting value of 4.8 W kg-1 to maximum values of 15–16 W kg-1. The rate of development of hypothermia and recovery there from were inversely related to age and body weight. Aminophylline (8 mg kg-1) did not affect resting or maximum metabolic rate, but after a second injection, aminophylline increased metabolic rate after warming (P < 0.05) and tended to shorten the absolute period of time to restore normal rectal temperature (P < 0.10). In exp. 2, a dose-response trial with six lambs each receiving 0, 2, 16 or 32 mg aminophylline indicated that dose rates of 16 and 32 mg kg-1 increased (P < 0.05) metabolic rate of lambs. In exp. 3, 21 lambs received either 0.9% saline or aminophylline (24 mg kg-1) injections. Mean heat production ranged from 13 to 15 W kg-1 and was increased approximately 7% (P < 0.01) by aminophylline. Aminophylline, therefore, has some potential as a treatment for hypothermia or to improve recovery from hypothermia in lambs by increasing metabolic rate during cold stress. Key words: Lamb, metabolic rate, hypothermia, thermoregulation, Aminophylline®, phosphodiesterase inhibitor

Relative influences of perceived parental monitoring and perceived peer involvement on adolescent risk behaviors: an analysis of six cross-sectional data sets

PURPOSE

To assess: (a) the relative impact of monitoring and peer involvement among six cohorts of African-American youth in their mid-adolescent years, over a decade of research in one urban area, and (b) the consistency of the impact of the two influences over time.

METHODS

Baseline data were collected from six cohorts involving 1279 low income African-American youth aged 13 to 16 years involved in community based studies conducted over a decade in an urban area. Self-reported behaviors, and perceptions of parental monitoring and peer risk-involvement were assessed through structured questions. Data were analyzed by frequency distribution, one-way ANOVA, and multiple logistic regression.

RESULTS

There was a rapid increase in sexual activity and substance use behaviors during mid-adolescence. Monitoring had a protective influence on substance use behaviors and sexual activity, but had no impact on condom use or drug trafficking. Peer involvement influenced all evaluated risk behaviors. The influences overall did not statistically change over time.

CONCLUSIONS

Despite the marked increase in risk behaviors during mid-adolescence, monitoring and peer involvement both influenced adolescent behaviors across each cohort.

Sustaining and broadening intervention impact: a longitudinal randomized trial of 3 adolescent risk reduction approaches

OBJECTIVE

To determine whether the addition of a parental monitoring intervention (Informed Parents and Children Together [ImPACT]) alone or with "boosters" could enhance (either broaden or sustain or both) the effect of a small group, face-to-face adolescent risk reduction intervention Focus on Kids (FOK).

METHODS

A longitudinal, randomized, community-based cohort study was conducted of 35 low-income, community-based, in-town settings. A total of 817 black youths aged 12 to 16 years at baseline were studied. After completion of baseline measures, youths were randomized to receive a face-to-face intervention alone (FOK only), a face-to-face intervention and a parental monitoring intervention (FOK plus ImPACT), or both of the above plus boosters (FOK plus ImPACT plus boosters). Risk and protective behaviors were assessed at 6 and 12 months after intervention.

RESULTS

At 6 months' follow-up, youths in families that were assigned to FOK plus ImPACT reported significantly lower rates of sexual intercourse, sex without a condom, alcohol use, and cigarette use and marginally lower rates of "risky sexual behavior" compared with youths in families that were assigned to FOK only. At 12 months after intervention, rates of alcohol and marijuana use were significantly lower and cigarette use and overall risk intention were marginally lower among FOK plus ImPACT youths compared with FOK only youths. With regard to the boosters delivered at 7 and 10 months, 2 risk behaviors--use of crack/cocaine and drug selling--were significantly lower among the youths who were assigned to receive the additional boosters compared with youths without the boosters. The rates of the other risk behaviors and intentions did not differ significantly.

CONCLUSIONS

The results of this randomized, controlled trial indicate that the inclusion of a parental monitoring intervention affords additional protection from involvement in adolescent risk behaviors 6 and 12 months later compared with the provision of an intervention that targets adolescents only. At the same time, the results of the present study do not provide sufficient evidence that booster sessions further improve targeted behaviors enough to include them in a combined parent and youth intervention.

Unprotected sex among African-American adolescents: a three-year study

This study examined the cumulative change of unprotected sex over a period of three years among 383 African American youth ages 9 to 15 at baseline who participated in a trial of a Human Immunodeficiency Virus (HIV) risk reduction intervention. Cumulative scores of sexual intercourse and failure to use condoms were compared between intervention and control groups. The results indicate that cumulatively over the three-year period, intervention youth reported significantly lower rates of failure to use a condom. The findings indicate that face-to-face interventions may offer significant cumulative protection from unprotected sex over the long-term.

Case study to evaluate a standing table for managing constipation

Standing devices have been advocated as a potentially beneficial treatment for constipation in persons with spinal cord injury (SCI); however, definitive data are lacking. A case of a patient who requested a standing table to treat chronic constipation is presented as an illustration of a method to address this problem on an individual patient level. The patient was a 62-year-old male with T12-L1 ASIA B paraplegia who was injured in 1965. The patient was on chronic narcotics for severe, nonoperable shoulder pain. His bowel program had been inadequate to prevent impactions. A systematic approach was used to measure the effects of a standing table on frequency of bowel movements (BMs) and on length of bowel care episodes. There was a significant (p < 0.05) increase in frequency of BMs and a decrease in bowel care time with the use of the standing table 5 times/week versus baseline. For this patient, the use of the standing table was a clinically useful addition to his bowel care program.

Parental monitoring intervention: practice makes perfect

Data from a randomized, controlled longitudinal study of African-American parent-adolescent dyads were analyzed to assess the impact of a parental monitoring intervention on (a) the similarity of parent and adolescent reporting of adolescent involvement in risk and protective activities, and (b) the reported rates of risk involvement by youth. Self-reported and parental perception of youth risk and protective activities were collected at baseline and 12 months postintervention. There was no significant difference between self-report and parent perception of youth activities among intervention dyads at follow-up. By contrast, parents in the control dyads significantly underestimated youth protective and risk activities. There was no evidence of a direct intervention effect on self-reported risk behaviors. These data confirm earlier findings that a culturally-tailored parental monitoring intervention can increase agreement of youth risk involvement among youth and their parents and provide evidence that this effect endures over time. The data argue for the need to consider intervention strategies that address both parents and youth.

Rapid assessment of rehabilitation options for functional disability

Although functional disability is common in elderly patients, physicians often overlook it or focus on acute illness, perhaps in part because they are unsure how to efficiently address the problem. A simple, stepwise protocol can be used in either an office or hospital setting to rapidly assess functional disabilities and identify potentially useful interventions.

Parental underestimates of adolescent risk behavior: a randomized, controlled trial of a parental monitoring intervention

OBJECTIVES

To develop and evaluate an intervention (ImPACT) seeking to increase monitoring (supervision and communication) by parents and guardians of African-American youth regarding high risk and protective behaviors; and to develop an instrument to assess parental monitoring, the Parent-Adolescent Risk Behavior Concordance Scale.

DESIGN/INTERVENTION

This research was a randomized, controlled longitudinal study. Baseline (preintervention), and 2 and 6 months postintervention data were obtained via a talking MacIntosh computer regarding youth and parent perceptions of youth involvement in 10 risk behaviors, parental monitoring and youth-parent communication, and condom-use skills. Intervention parents and youth received the ImPACT program and a video emphasizing parental supervision and discussion, followed by a structured discussion and role-play emphasizing key points. Control parents and youth received an attention-control program on goal-setting, which also included an at-home video and discussion.

PARTICIPANTS

A total of 237 parents and one each of their youth (ages 12-16 years) recruited from eight public housing developments located in a city in the mid-Atlantic region.

RESULTS

Similarity of youth and parental reporting on the Parent-Adolescent Risk Behavior Concordance Scale was positively correlated with protective behaviors, perceived parental monitoring, and good parent-youth communication. At baseline, parents significantly underestimated their youth's risk behaviors. However, 2 and 6 months postintervention, the ImPACT program increased similarity of reports by youth and their parents of youth involvement in risk and protective behaviors. In addition, at 6 months postintervention, intervention (compared to control) youths and parents also demonstrated higher levels of condom-use skills.

CONCLUSION

Parental monitoring interventions such as ImPACT should be given to parents in conjunction with more traditional youth-centered risk-reduction interventions.

Parental influence on adolescent sexual behavior in high-poverty settings

BACKGROUND

African American adolescents living in high-poverty urban settings are at increased risk for early sexual initiation and sexually transmitted diseases.

OBJECTIVE

To determine whether parental strategies to monitor their children's social behavior and to communicate with them about sexual risks help to reduce the initiation of risky sexual behavior and prevent the resulting adverse health outcomes.

METHODS

To assess the viability of these strategies, we surveyed a stratified cross-section of African American children aged 9 to 17 years (N = 355) living in urban public housing. Talking computers were used to increase the confidentiality and comparability of the interviews across the wide age range.

RESULTS

Children who reported high levels of parental monitoring were less likely to report initiating sex in pre-adolescence (aged < or = 10 years) and reported lower rates of sexual initiation as they aged. Children who reported receiving both greater monitoring and communication concerning sexual risks were also less likely to have engaged in anal sex. Communication was also positively related to the initiation of condom use and consistent condom use. The protective correlates of these parenting strategies were independent of the type of guardian (mother vs other family member).

CONCLUSION

Interventions with parents and other guardians to increase monitoring and communication about sexual risks seem to be promising health-promotion strategies for adolescents in high-risk settings.

TNF recruits TRADD to the plasma membrane but not the trans-Golgi network, the principal subcellular location of TNF-R1

The subcellular localization of TNF-R1 to the Golgi apparatus, initially observed in endothelial cells, has been confirmed using transfection of bovine aortic endothelial cells with a human TNF-R1 expression plasmid. The subcellular interactions of TNF-R1 and the TRADD (TNFR-associated death domain protein) adaptor protein have been analyzed in the human monocyte cell line U937 and the human endothelial cell line ECV304 by confocal immunofluorescence microscopy and by Western blot analysis of fractionated cell extracts. In untreated cells, in which TNF-R1 is found on the cell surface but principally localizes to the trans-Golgi network, TRADD is concentrated in the cis- or medial-Golgi region, but separates from the Golgi during cell fractionation. Coimmunoprecipitation studies have shown that TRADD binds to TNF-R1 within 1 min of TNF treatment in a cell fraction-containing plasma membrane. This association is followed by a gradual dissociation, which is prevented if receptor-mediated endocytosis is inhibited by hypertonic medium. In contrast, no association is detected between TRADD and TNF-R1 in the Golgi in response to exogenous TNF at any time examined. These results suggest that although TNF-R1 is predominantly a Golgi-associated protein and TRADD also localizes to the Golgi region, exogenous TNF causes TRADD to bind to TNF-R1 only at the plasma membrane.

Drug trafficking and drug use among urban African-American adolescents: a causal analysis

OBJECTIVE

To test the hypothesis that involvement in drug trafficking leads to illicit drug use among urban African-American adolescents.

METHODS

Self-reports of substance use, illicit drug use, and drug trafficking were obtained at baseline and every 6 months for 24 months from 383 African-American early adolescents. Transitions between involvement in drug trafficking and illicit drug use over time were examined. Path analysis was conducted to examine the causal relation between drug trafficking and drug use.

RESULTS

Among the 35 youth who were initially involved only in drug trafficking, 22 (67%) subsequently used illicit drugs. Of the 53 youth who were initially involved only in illicit drug use, only 19 (42%) continued using drugs at later waves (p < 0.05). Path analysis revealed that baseline drug trafficking had a strong effect on subsequent drug trafficking and drug use, whereas baseline drug use did not have an effect on subsequent drug use or drug trafficking.

CONCLUSIONS

Initiation of drug trafficking by adolescents appears to lead to sustained involvement in drug-related activities, including continued drug trafficking and drug use. By contrast, initiation of drug use does not necessarily lead to continued involvement in drug-related behaviors.

Evolution of risk behaviors over 2 years among a cohort of urban African American adolescents

OBJECTIVE

To examine the evolution of risk behaviors over 2 years among a community-based cohort of low-income African American preadolescents and young adolescents enrolled in a randomized trial of an acquired immunodeficiency syndrome risk reduction intervention.

DESIGN

Longitudinal, community-based cohort.

SETTING

Nine recreation centers serving 3 public housing developments.

SUBJECTS

Three hundred eighty-three African American youths aged 9 through 15 years at baseline.

INTERVENTIONS

Frequency distributions, chi 2 analyses, and regression analyses regarding 10 risk behaviors were conducted. To assess whether a specific risk behavior or its protective (nonrisk) behavioral analogue, composing a risk-nonrisk behavioral complex (eg, was sexually active and was sexually abstinent or used drugs and refrained from drugs), was stable over time, kappa values were determined for the 10 risk-nonrisk behavioral complexes.

MAIN OUTCOME MEASURES

Instrument assessing risk/ behaviors administered at baseline and every 6 months aurally and visually via talking computer.

RESULTS

The prevalence of sexual intercourse, cigarette smoking, alcohol consumption, and drug use increased notably over time. Drug use increased from a 6-month cumulative prevalence of 7% at baseline to 27% at the 24-month follow-up (P < .001). Cumulatively over the 2-year study interval, 81% of youths had engaged in fighting, 58% had engaged in sexual intercourse, and from 33% to 40% had engaged in truancy, knife or bat carrying or both, alcohol consumption, drug use, and cigarette smoking. All of the risk-nonrisk behavioral complexes except weapon carrying were stable during the semiannual assessment intervals. Fighting (kappa = 0.22, P < .01), sexual intercourse (kappa = 0.33, P < .001), alcohol consumption (kappa = 0.21, P < .001), and unprotected sexual intercourse (kappa = 0.34, P < .05) were stable for 2 years. Six risk-nonrisk behavioral complexes were stable for the 2-year interval among youths aged 13 through 15 years at baseline, while only 2 risk-nonrisk behavioral complexes were stable among younger youths. The intervention seemed to affect the stability of 4 risk behaviors: truancy, drug use, unprotected sexual intercourse, and, possibly, fighting. For unprotected sexual intercourse, this intervention effect seemed to be due to stabilization of nonparticipation in risky behavior. Intervention youths were less likely to adopt a risk behavior (ie, engage in it for > or = 2 risk assessment periods) than control youths, but they were not less likely to experiment with a risk behavior.

CONCLUSIONS

There is evidence that although the prevalence of risk behaviors does change with age, most risk-nonrisk behavioral complexes seem to be relatively stable over time and stability may increase with time. Risk reduction interventions seem to decrease risk adoption, stabilize nonrisk behaviors, and possibly destabilize risk behavior.

Effectiveness of the 40 adolescent AIDS-risk reduction interventions: a quantitative review

OBJECTIVE

(1) To review evaluations of Acquired Immunodeficiency Syndrome (AIDS) prevention interventions targeting adolescents to determine whether these efforts have been effective in reducing risk behaviors. (2) To examine the relation between intervention design issues and outcomes measures.

METHOD

A systematic review of five electronic databases and hand-searches of 11 journals, were undertaken for articles published from January 1983 through November 1995 that reported evaluations of adolescent AIDS risk-reduction interventions conducted in the United States. Outcomes examined include: improved attitudes about AIDS risk and protective behaviors, increased intention to abstain from sexual intercourse or to use condoms, and reduced sexual risk behaviors.

RESULTS

Forty studies that met preestablished inclusion criteria were found. For each outcome assessed, a majority of studies found a positive intervention impact (88% of studies assessing changes in knowledge; 58% changes in attitude, 60% changes in intention to use condoms, 73% in condom use, and 64% in decreasing number of sexual partners). Interventions that demonstrated an increase in intention to use a condom were significantly more likely to be theory-based than those that did not show any significant changes in intention (100% vs. 0%, p = .048). Interventions that increased condom use and decreased the number of sexual partners were longer in duration than those that did not improve these outcomes.

CONCLUSIONS

AIDS risk reduction interventions can be effective in improving knowledge, attitudes, and behavioral intentions and in reducing risk practices. The positive relationship between improved outcomes and several elements of intervention design underscores the need for increased focus on intervention design in future studies.

Challenges and rewards of involving community in research: an overview of the "Focus on Kids" HIV Risk Reduction Program

Acquired immunodeficiency syndrome (AIDS) continues to be a significant concern for adolescents, especially in minority populations. There is a scarcity of knowledge of the cultural context of sexual behavior in this age group and the influences that lead to early initiation of sex and unsafe sex. Few efforts targeting young adolescents have been community based, although there has been an increased awareness of the need for such research and intervention programs. Four key processes have been defined in gaining community participation in health education programs: (a) defining the community and reaching the community; (b) recognizing tensions among service, research, and community participation; (c) involving community residents; and (d) considering cultural differences in a community. These processes are used to describe the "Focus on Kids" project, a human immunodeficiency virus (HIV) risk reduction intervention that resulted in significant increases in condom use demonstrated by a randomized controlled trial.

Design issues addressed in published evaluations of adolescent HIV-risk reduction interventions: a review

OBJECTIVE

This study was conducted to determine: (1) issues in intervention design that have been addressed in behavioral interventions targeting human immunodeficiency virus (HIV)-risk behaviors among adolescents; (2) specific choices made in intervention design; (3) historic changes in the likelihood that issues in intervention design will be addressed; and (4) if an association exists between quality of evaluation design and the number of intervention design issues addressed.

DESIGN

Literature search employing five electronic databases and 11 journals for articles published from January 1983 through December 1993 reporting evaluations of adolescent HIV-risk reduction interventions.

MAIN OUTCOMES MEASURES

The frequency with which 12 issues in intervention design were addressed: basing the intervention on a theory of behavioral change; specifying a target population; involving the targeted community in the formulation of the intervention; addressing developmental issues; providing facts; strengthening interpersonal skills; describing the media (format) for delivering the intervention; specifying potentially relevant characteristics of the interventionists; describing the duration of the intervention; providing boosters; pilot testing the intervention; and including other potentially augmentative elements.

RESULTS

Twenty-eight published intervention articles were included in these analyses. The median number of intervention design issues addressed in any study was six (range three to nine), although this number increased significantly over time (p < .01). There was substantial variability in the frequency with which each individual design issue was addressed, with some design issues (e.g., inclusion of specific facts and the description of the channel employed) being addressed in all studies. Other design issues were addressed in less than one-quarter of studies [e.g., basing the intervention on a theory of behavioral change (18%) and addressing developmental issues (21%)]. The targeted community was involved in one-third of studies. More recent studies and studies employing a randomized evaluation design with both preintervention and postintervention assessments addressed more intervention design issues than did earlier studies and studies employing other evaluation designs (p = .01 and p = .03, respectively).

CONCLUSION

The majority of published adolescent HIV-risk reduction studies have not addressed important issues in intervention design. However, more recent studies and studies employing a strong evaluation design have addressed a greater number of these issues. Frameworks to guide intervention efforts (e.g., to serve as "practice guidelines") are needed to allow for both accurate replication and meaningful comparison of differing intervention approaches.

A randomized, controlled effectiveness trial of an AIDS prevention program for low-income African-American youths

BACKGROUND

Some interventions to reduce the risk of the acquired immunodeficiency syndrome (AIDS) that target youths have resulted in short-term increases in self-reported condom use. However, long-term intervention effects have not been assessed.

STUDY QUESTION

Can a theoretically and culturally based, AIDS-risk reduction intervention delivered to naturally formed peer groups increase self-reported condom use among African-American early adolescents at 6 and 12 months of follow-up?

METHOD

A randomized, controlled trial of a community-based intervention delivered in eight weekly sessions involved 76 naturally formed peer groups consisting of 383 (206 intervention and 177 control) African-American youths 9 to 15 years of age. A theory-based, culturally and developmentally tailored instrument that assessed perceptions, intentions, and self-reported sexual behaviors was administered to all subjects at baseline (preintervention) and 6 and 12 months later.

RESULTS

At baseline, 36% of youths were sexually experienced, and by 12 months of follow-up, 49% were sexually experienced. Self-reported condom use rates were significantly higher among intervention than control youths (85% vs 61%; P<.05) at the 6-month follow-up. However, by 12 months, rates were no longer significantly higher among intervention youths. The intervention impact at 6 months was especially strong among boys (85% vs 57%; P<.05) and among early teens (13 to 15 years old) (95% vs 60%; P<.01). Self-reported condom use intention was also increased among intervention youths at 6 months but not at 12 months. Some perceptions were positively affected at 6 months, but the change did not persist at 12 months.

CONCLUSIONS

High rates of sexual intercourse underscore the urgent need for effective AIDS-risk reduction interventions that target low-income urban, African-American preteens and early teens. A developmentally and culturally tailored intervention based on social-cognitive theory and delivered to naturally formed peer groups recruited from community settings can increase self-reported condom use. The strong short-term improvements in behaviors and intentions followed by some relapse over longer periods argue for a strengthened program and research focus on sustainability.

Sexually transmitted diseases, human immunodeficiency virus, and pregnancy prevention. Combined contraceptive practices among urban African-American early adolescents

OBJECTIVE

To evaluate the success of efforts to educate youth not only to use prescription contraceptives to avoid pregnancy, but also to use condoms to avoid sexually transmitted diseases, including infection with the human immunodeficiency virus.

METHODS

Longitudinal study of 383 African-American youth aged 9 to 15 years enrolled in a randomized, controlled trial of an acquired immunodeficiency syndrome (AIDS) risk reduction intervention. Data about contraceptive practices were obtained at baseline and 6, 12, and 18 months later using a culturally and developmentally appropriate risk assessment tool administered with "talking" computers (Macintosh, Apple Computer Inc, Cupertino, Calif).

RESULTS

Approximately three fourths of sexually active youth used some form of contraception in each 6-month round, with almost half of the youth using combinations of contraceptives. Among all youth at baseline and among control youth throughout the study, more than half used condoms and more than two thirds who used oral contraceptives also used condoms. Receipt of an AIDS education intervention was associated with use of more effective contraceptive practices (eg, condoms and another prescription or nonprescription method of birth control). After receiving the intervention, more than 80% of the youth who used oral contraceptives also used condoms. Contraceptive practices showed considerable stability. Knowledge about AIDS was positively associated with use of more effective contraceptive methods.

CONCLUSIONS

Many youth are using condoms and prescription birth control simultaneously, and these use rates can be increased through AIDS education interventions.