Multilevel and kin selection in a connected world.

Wild et al. argue that the evolution of reduced virulence can be understood from the perspective of inclusive fitness, obviating the need to evoke group selection as a contributing causal factor. Although they acknowledge the mathematical equivalence of the inclusive fitness and multilevel selection approaches, they conclude that reduced virulence can be viewed entirely as an individual-level adaptation by the parasite. Here we show that their model is a well-known special case of the more general theory of multilevel selection, and that the cause of reduced virulence resides in the opposition of two processes: within-group and among-group selection. This distinction is important in light of the current controversy among evolutionary biologists in which some continue to affirm that natural selection centres only and always at the level of the individual organism or gene, despite mathematical demonstrations that evolutionary dynamics must be described by selection at various levels in the hierarchy of biological organization.

Assessing adherence in the CAPRISA 004 tenofovir gel HIV prevention trial: results of a nested case-control study.

Adherence undeniably impacts product effectiveness in microbicide trials, but the connection has proven challenging to quantify using routinely collected behavioral data. We explored this relationship using a nested case-control study in the CAPRISA 004 Tenofovir (TFV) gel HIV prevention trial. Detailed 3-month recall data on sex events, condom and gel use were collected from 72 incident cases and 205 uninfected controls. We then assessed how the relationship between self-reported adherence and HIV acquisition differed between the TFV and placebo gel groups, an interaction effect that should exist if effectiveness increases with adherence. The CAPRISA 004 trial determined that randomization to TFV gel was associated with a significant reduction in risk of HIV acquisition. In our nested case-control study, however, we did not observe a meaningful decrease in the relative odds of infection-TFV versus placebo-as self-reported adherence increased. To the contrary, exploratory sub-group analysis of the case-control data identified greater evidence for a protective effect of TFV gel among participants reporting less than 80 % adherence to the protocol-defined regimen (odds ratio (OR) 0.30; 95 % CI 0.11-0.78) than among those reporting ≥ 80 % adherence (Odds Ratio 0.81; 95 % CI 0.34-1.92). The small number of cases may have inhibited our ability to detect the hypothesized interaction between adherence and effectiveness. Nonetheless, our results re-emphasize the challenges faced by investigators when adherence may be miss-measured, miss-reported, or confounded with the risk of HIV.

Contraceptive effectiveness, pharmacokinetics, and safety of Sayana® Press when injected every four months: a multicenter phase 3 trial.

BACKGROUND: Sayana Press® is a 3-monthly contraceptive injection approved by regulatory agencies in more than 40 countries worldwide. Existing effectiveness and pharmacokinetics (PK) data suggest that high contraceptive efficacy may be maintained if the reinjection interval of Sayana Press is extended from 3 to 4 months. METHODS: We conducted a phase 3 trial at three sites in the Dominican Republic, Brazil, and Chile from September 2017 through April 2020. We enrolled 750 women at risk of pregnancy who agreed to use Sayana Press off-label every 4 months (3 treatment cycles) for 12 months. The effectiveness cohort included 710 participants randomized equally to receive injections in the abdomen or thigh. Forty additional participants received injections in the back of the upper arm for comparative PK analyses. The primary outcome was pregnancy, defined by a positive urine pregnancy test confirmed by ultrasound and/or serum human chorionic gonadotropin. Secondary outcomes included PK, safety, and acceptability. Laboratory and trial Sponsor staff were blind to injection site. This study is registered with ClinicalTrials.gov, number NCT03154125. FINDINGS: There were no pregnancies during follow-up; the Pearl Index during 629.3 woman-years (WY) of follow-up in the primary effectiveness analysis was 0.00 (95% CI 0.00, 0.59). Pharmacokinetic profiles differed by injection site, with higher geometric mean (GM) medroxyprogesterone acetate concentrations for the abdomen than the thigh and arm. At month 8, significantly higher GM concentrations were observed in the abdomen and the thigh as compared to the arm, as well as at month 12 in the abdomen as compared to the arm. Injection site reactions were reported by 10.7% of participants. INTERPRETATION: Both pregnancy and PK results confirm that Sayana Press is a highly effective contraceptive method when administered every 4 months. These findings may inform modification of the dosing schedule, or duration of the grace period for reinjection, or both, to reduce overall drug exposure while maintaining contraceptive efficacy. FUNDING: This work is made possible by the generous support of the American people through the U.S. Agency for International Development (USAID), provided to FHI 360 through Cooperative Agreement AID-OAA-A-15-00,045, and a grant from the Gates Foundation. The contents are the responsibility of FHI 360 and do not necessarily reflect the views of USAID, the United States Government, or the Gates Foundation, nor does any mention of trade names, commercial products, or organizations imply endorsement by FHI 360, USAID, the United States Government, or the Gates Foundation.

Kidney function in tenofovir disoproxil fumarate-based oral pre-exposure prophylaxis users: a systematic review and meta-analysis of published literature and a multi-country meta-analysis of individual participant data.

BACKGROUND: Previous WHO guidance on tenofovir disoproxil fumarate-based oral pre-exposure prophylaxis (PrEP) suggests measuring creatinine levels at PrEP initiation and regularly afterwards, which might represent barriers to PrEP implementation and uptake. We aimed to systematically review published literature on kidney toxicity among tenofovir disoproxil fumarate-based oral PrEP users and conducted an individual participant data meta-analysis (IPDMA) on kidney function among PrEP users in a global implementation project dataset. METHODS: In this systematic review and meta-analysis we searched PubMed up to June 30, 2021, for randomised controlled trials (RCTs) or cohort studies that reported on graded kidney-related adverse events among oral PrEP users (tenofovir disoproxil fumarate-based PrEP alone or in combination with emtricitabine or lamivudine). We extracted summary data and conducted meta-analyses with random-effects models to estimate relative risks of grade 1 and higher and grade 2 and higher kidney-related adverse events, measured by elevated serum creatinine or decline in estimated creatinine clearance or estimated glomerular filtration rate. The IPDMA included (largely unpublished) individual participant data from 17 PrEP implementation projects and two RCTs. Estimated baseline creatinine clearance and creatinine clearance change after initiation were described by age, gender, and comorbidities. We used random-effects regressions to estimate the risk in decline of creatinine clearance to less than 60 mL/min. FINDINGS: We identified 62 unique records and included 17 articles reporting on 11 RCTs with 13 523 participants in meta-analyses. PrEP use was associated with increased risk of grade 1 and higher kidney adverse events (pooled odds ratio [OR] 1·49, 95% CI 1·22-1·81; I2=25%) and grade 2 and higher events (OR 1·75, 0·68-4·49; I2=0%), although the grade 2 and higher association was not statistically significant and events were rare (13 out of 6764 in the intervention group vs six out of 6782 in the control group). The IPDMA included 18 676 individuals from 15 countries (1453 [7·8%] from RCTs) and 79 (0·42%) had a baseline estimated creatinine clearance of less than 60 mL/min (increasing proportions with increasing age). Longitudinal analyses included 14 368 PrEP users and 349 (2·43%) individuals had a decline to less than 60 mL/min creatinine clearance, with higher risks associated with increasing age and baseline creatinine clearance of 60·00-89·99 mL/min (adjusted hazard ratio [aHR] 8·49, 95% CI 6·44-11·20) and less than 60 mL/min (aHR 20·83, 12·83-33·82). INTERPRETATION: RCTs suggest that risks of kidney-related adverse events among tenofovir disoproxil fumarate-based oral PrEP users are increased but generally mild and small. Our global PrEP user analysis found varying risks by age and baseline creatinine clearance. Kidney function screening and monitoring might focus on older individuals, those with baseline creatinine clearance of less than 90 mL/min, and those with kidney-related comorbidities. Less frequent or optional screening among younger individuals without kidney-related comorbidities may reduce barriers to PrEP implementation and use. FUNDING: Unitaid, Bill & Melinda Gates Foundation, WHO.

Lack of effectiveness of cellulose sulfate gel for the prevention of vaginal HIV transmission.

BACKGROUND: Women make up more than 50% of adults living with human immunodeficiency virus (HIV) infection or the acquired immunodeficiency syndrome (AIDS) in sub-Saharan Africa. Thus, female-initiated HIV prevention methods are urgently needed. METHODS: We performed a randomized, double-blind, placebo-controlled trial of cellulose sulfate, an HIV-entry inhibitor formulated as a vaginal gel, involving women at high risk for HIV infection at three African and two Indian sites. The primary end point was newly acquired infection with HIV type 1 or 2. The secondary end point was newly acquired gonococcal or chlamydial infection. The primary analysis was based on a log-rank test of no difference in the distribution of time to HIV infection, stratified according to site. RESULTS: A total of 1398 women were enrolled and randomly assigned to receive cellulose sulfate gel (706 participants) or placebo (692 participants) and had follow-up HIV test data. There were 41 newly acquired HIV infections, 25 in the cellulose sulfate group and 16 in the placebo group, with an estimated hazard ratio of infection for the cellulose sulfate group of 1.61 (P=0.13). This result, which is not significant, is in contrast to the interim finding that led to the trial being stopped prematurely (hazard ratio, 2.02 [corrected]; P=0.05 [corrected]) and the suggestive result of a preplanned secondary (adherence-based) analysis (hazard ratio, 2.02; P=0.05). No significant effect of cellulose sulfate as compared with placebo was found on the risk of gonorrheal infection (hazard ratio, 1.10; 95% confidence interval [CI], 0.74 to 1.62) or chlamydial infection (hazard ratio, 0.71; 95% CI, 0.47 to 1.08). CONCLUSIONS: Cellulose sulfate did not prevent HIV infection and may have increased the risk of HIV acquisition. (ClinicalTrials.gov number, NCT00153777; and Current Controlled Trials number, ISRCTN95638385.)

Adherence and its measurement in phase 2/3 microbicide trials.

Adherence optimization and measurement have emerged as critically challenging issues for clinical trials of topical microbicides. Although microbicide trials have routinely collected adherence data, their utilization in trial design, implementation, and interpretation has been inconsistent. Drawing on data-driven presentations from several focused meetings, this paper synthesizes lessons from past microbicide trials and provides recommendations for future trials of microbicide and other HIV prevention technologies. First, it describes four purposes for adherence data collection, with particular attention to intention-to-treat versus adherence-adjusted analyses for determining effectiveness. Second, the microbicide field's experiences with adherence measures and data collection modes are discussed, including the strengths and weaknesses of various options and approaches for improving measurement. Then, several approaches to optimizing trial participants' adherence are presented. The paper concludes with a set of recommendations for immediate use or further research.

Comparison of pregnancy incidence among African women in a randomized trial of intramuscular depot medroxyprogesterone acetate (DMPA-IM), a copper intrauterine device (IUDs) or a levonorgestrel (LNG) implant for contraception.

OBJECTIVE: The objective was to address bias in contraception efficacy studies through a randomized study trial of intramuscular depot medroxyprogesterone acetate (DMPA-IM), a copper intrauterine device (IUDs) and a levonorgestrel (LNG) implant. STUDY DESIGN: We analyzed data from the Evidence for Contraceptive Options and HIV Outcomes Trial, which assessed HIV incidence among 7829 women from 12 sites in eSwatini, Kenya, South Africa and Zambia seeking effective contraception and who consented to be randomized to DMPA-IM, copper IUD or LNG implant. We used Cox proportional hazards regression adjusted for condom use to compare pregnancy incidence during both perfect and typical (i.e., allowing temporary interruptions) use. RESULTS: A total of 7710 women contributed to this analysis. Seventy pregnancies occurred during perfect and 85 during typical use. There was no statistically significant difference in perfect use pregnancy incidence among the methods: 0.61 per 100 woman-years for DMPA-IM [95% confidence interval (CI) 0.36-0.96], 1.06 for copper IUD (95% CI 0.72-1.50) and 0.63 for LNG implants (95% CI 0.39-0.96). Typical use pregnancy rates were also largely similar: 0.87 per 100 woman-years for DMPA-IM (95% CI 0.58-1.25), 1.11 for copper IUD (95% CI 0.77-1.54) and 0.63 for LNG implants (95% CI 0.39-0.96). CONCLUSIONS: In this randomized trial of highly effective contraceptive methods among African women, both perfect and typical use resulted in low pregnancy rates. Our findings provide strong justification for improving access to a broader range of longer-acting contraceptive options including LNG implants and copper IUD for African women. IMPLICATIONS STATEMENT: Data from this study support recommendations to providers, policy makers and patients that all of these methods provide safe and highly effective contraception for African women.

Monitoring and assessment of wetlands using Earth Observation: the GlobWetland project.

The overall objective of the Ramsar Convention, signed in 1971, is the conservation and wise use of wetlands by national action and international cooperation as a means to achieving sustainable development. This complex and challenging task requires national, local and international bodies involved in the implementation of the convention to rely on suitable geo-information to better understand wetland areas, complete national inventories, perform monitoring activities, carry out assessments and put in practice suitable management plans based on updated and reliable information. In the last years, Earth Observation (EO) technology has been revealed as a key tool and unique information source to support the environmental community in different application domains, including wetlands' conservation and management. In this context, the European Space Agency (ESA) in collaboration with the Ramsar Secretariat launched in 2003 the "GlobWetland" project in order to demonstrate the current capabilities of Earth Observation technology to support inventorying, monitoring, and assessment of wetland ecosystems. This paper collects the main results and findings of the "GlobWetland" project, providing an overview of the current capabilities and limits of EO technology as a tool to support the implementation of the Ramsar Convention. The project was carried out in collaboration with several regional, national and local conservation authorities and wetland managers, involving 50 different wetlands across 21 countries on four continents. This large range of users provided an excellent test bed to assess the potential of this technology to be applied in different technical, economic and social conditions.

Decreased condom breakage and slippage rates after counseling men at a sexually transmitted infection clinic in Jamaica.

PURPOSE: Our objective was to evaluate condom failure (breakage and slippage) rates before and those during a trial that provided instructions on correct condom use. METHOD: Our analysis was based on 314 men who presented with urethral discharge at Jamaica's largest sexually transmitted infection clinic and were enrolled into our 6-month trial. RESULTS: Participants reported breaking 18.5% (95% confidence interval=12.8-24.1%) of their condoms during the 7 days prior to the screening visit and having 3.5% (95% confidence interval=1.2-5.7%) of their condoms slip off completely. After the condom counseling provided during the screening visit, breakage rates decreased (p<.05) and remained below 10% throughout the trial. During in-depth interviews, the men who reported frequent condom failures cited (1) improper storage/exposure to heat, (2) improper handling while putting on condoms and (3) use of lubricants/improper lubricants as the possible reasons for their high failure rates. CONCLUSION: Although the rates of reported condom breakage and slippage decreased significantly after counseling, we need to improve the quality of condom counseling to further reduce failure rates.

The Program Plan Index: an evaluation tool for assessing the quality of adolescent pregnancy prevention program plans.

To assess process, impacts, and outcomes among 45 distinct county teen pregnancy prevention initiatives, several standardized data collection procedures, instruments, and protocols were developed including the Program Plan Index (PPI). The PPI was developed to determine if program plans met legislative requirements and were consistent with best practices in public health program planning and teen pregnancy prevention. Analysis of proposals from 45 counties revealed that 12 county plans were evaluated as deficient, 14 as low, 14 as acceptable, 4 as good, and 1 as excellent. Explanations for overall performance included the following: criteria used to develop the PPI based on an in-depth understanding of best practices, variations in the criteria for county request for proposals, lack of prevention expertise at the local level, and minimal time for grantees to draw down funds. Statewide efforts to improve funded community-based teen pregnancy prevention planning, implementation, and empowerment evaluation efforts are ongoing.

Evaluation of statewide teen pregnancy prevention initiatives: challenges, methods, and lessons learned.

Evaluation of community-based, teen pregnancy prevention initiatives is complex. This article describes the challenges encountered and solutions derived while creating a comprehensive evaluation of teen pregnancy prevention initiatives across 46 counties in a southeastern state. Background information on the evaluation and highlights of the data collection constructs, methods, and tools are provided. In particular, the efforts to appropriately scope the evaluation activities and the use of qualitative and quantitative methods are discussed. In addition, the key lessons learned from the evaluation are presented. This article's discussion of contextual influences and evaluation planning and implementation efforts may benefit program practitioners and evaluators in their future evaluation activities.

FEM-PrEP: adherence patterns and factors associated with adherence to a daily oral study product for pre-exposure prophylaxis.

BACKGROUND: Several clinical trials have demonstrated the safety and effectiveness of oral tenofovir disoproxil fumarate (TDF), with or without emtricitabine (FTC), as pre-exposure prophylaxis (PrEP) for reducing the risk of HIV acquisition. Adherence to the study product was insufficient to demonstrate the effectiveness of FTC/TDF in 2 PrEP clinical trials conducted among women (FEM-PrEP and the Vaginal and Oral Interventions to Control the Epidemic study), but further analyses of adherence in these studies may inform PrEP demonstration projects and future HIV prevention clinical trials. METHODS: We randomly selected a subcohort of 150 participants randomized to FTC/TDF in 3 FEM-PrEP sites (Bondo, Kenya; Bloemfontein, South Africa; and Pretoria, South Africa) to examine adherence levels over time and to assess factors associated with adherence, based on plasma tenofovir and intracellular tenofovir diphosphate drug concentrations in specimens collected at 4-week visit intervals. RESULTS: We observed drug concentrations consistent with good adherence in 28.5% of all visit intervals when drug was available to use, but only 12% of participants achieved good adherence throughout their study participation. In multivariate analysis, the Bloemfontein site [odds ratio (OR): 2.43; 95% confidence interval (CI): 1.32 to 4.48] and liking the pill color (OR: 2.93; 95% CI: 1.18 to 7.27) were positively associated with good adherence, whereas using oral contraceptive pills at enrollment was negatively associated with good adherence (OR: 0.37; 95% CI: 0.18 to 0.74). CONCLUSIONS: Most participants did not regularly adhere to the study product throughout their trial participation, although a small minority did. Few factors associated with good adherence to the study product were identified in FEM-PrEP.

Performance of a rapid and simple HIV testing algorithm in a multicenter phase III microbicide clinical trial.

A multitest sequential algorithm based on rapid and simple (R/S) assays was applied for the diagnosis of HIV infection among participants in a phase 3 microbicide effectiveness trial. HIV testing was performed on finger-prick blood samples obtained from patients after their enrollment in the trial. The specimens were tested in a serial procedure using three different rapid tests (Determine HIV-1/2 [Abbott], SD Bioline HIV-1/2 3.0 [Standard Diagnostics], and Uni-Gold HIV [Trinity Biotech]). In the event of discordant results between the Determine HIV-1/2 and SD Bioline HIV-1/2 3.0 tests, the third assay (Uni-Gold HIV) determined the final outcome. When the final outcome was positive, a second specimen was collected and tested with the same algorithm, only if a positive result was obtained with this sample the participant was informed of her positive serostatus. A total of 5,734 postenrollment specimens obtained from 1,398 women were tested. Forty-six women tested positive according to the testing algorithm performed on the first collected specimen. Confirmatory testing results obtained at the ITM confirmed that 42 women were truly infected. Two of four initial false positives tested negative upon analysis of a second blood specimen. The other two tested false positive twice using specimens collected the same day. A high percentage of specimens reactive with the Determine HIV-1/2 assay was only observed at the study site in Kampala. This result did not appear to be associated with pregnancy or malaria infection. We conclude that HIV testing algorithms, including only R/S assays, are suitable for use in clinical trials, provided that adequate quality assurance procedures are in place.

Results of a safety and feasibility study of the diaphragm used with ACIDFORM Gel or K-Y Jelly.

BACKGROUND: New strategies are needed for preventing HIV infection in women. One potential approach is female-initiated use of an effective topical microbicidal gel in combination with a cervical barrier such as the diaphragm. STUDY DESIGN: Randomized, placebo-controlled safety and feasibility trial of diaphragm with vaginal gel during 6 months of use among 120 HIV-negative sexually active women in Johannesburg, South Africa. RESULTS: Pelvic event rates were 338.3 and 247.1 per 100 women-years in the ACIDFORM gel (plus diaphragm) and K-Y(R) Jelly (plus diaphragm) groups, respectively, with a rate ratio of 1.37 (95% CI: 0.89-2.11). Most women found diaphragm with gel use acceptable. CONCLUSION: There was a trend towards more safety events in the ACIDFORM plus diaphragm group, although no primary comparisons achieved statistical significance. Adding an effective microbicidal gel to a mechanical barrier may still prove to be an important and acceptable combination method to help prevent pregnancy and HIV/sexually transmitted infection transmission.

Effectiveness of cellulose sulfate vaginal gel for the prevention of HIV infection: results of a Phase III trial in Nigeria.

BACKGROUND: This trial evaluated the safety and effectiveness of 6% cellulose sulfate vaginal gel in preventing male-to-female vaginal transmission of HIV, gonorrhea and chlamydial infection. METHODS: This Phase III, double-blind, randomized, placebo-controlled trial was conducted between November 2004 and March 2007 in Lagos and Port Harcourt, Nigeria. We enrolled 1644 HIV-antibody negative women at high risk of HIV acquisition. Study participants were randomized 1:1 to cellulose sulfate or placebo and asked to use gel plus a condom for each act of vaginal intercourse over one year of follow-up. The participants were evaluated monthly for HIV, gonorrhea and chlamydial infection, and for adverse events. RESULTS: The trial was stopped prematurely after the data safety monitoring board of a parallel trial concluded that cellulose sulfate might be increasing the risk of HIV. In contrast, we observed fewer infections in the active arm (10) than on placebo (13), a difference that was nonetheless not statistically significant (HR = 0.8, 95% CI 0.3-1.8; p = 0.56). Rates of gonorrhea and chlamydial infection were lower in the CS group but the difference was likewise not statistically significant (HR = 0.8, 95% CI 0.5-1.1; p = 0.19 for the combined STI outcome). Rates of adverse events were similar across study arms. No serious adverse events related to cellulose sulfate use were reported. CONCLUSIONS: Cellulose sulfate gel appeared to be safe in the evaluated study population but we found insufficient evidence that it prevented male-to-female vaginal transmission of HIV, gonorrhea or chlamydial infection. The early closure of the trial compromised the ability to draw definitive conclusions about the effectiveness of cellulose sulfate against HIV. TRIAL REGISTRATION: ClinicalTrials.gov NCT00120770.

Tenofovir disoproxil fumarate for prevention of HIV infection in women: a phase 2, double-blind, randomized, placebo-controlled trial.

OBJECTIVES: The objective of this trial was to investigate the safety and preliminary effectiveness of a daily dose of 300 mg of tenofovir disoproxil fumarate (TDF) versus placebo in preventing HIV infection in women. DESIGN: This was a phase 2, randomized, double-blind, placebo-controlled trial. SETTING: The study was conducted between June 2004 and March 2006 in Tema, Ghana; Douala, Cameroon; and Ibadan, Nigeria. PARTICIPANTS: We enrolled 936 HIV-negative women at high risk of HIV infection into this study. INTERVENTION: Participants were randomized 1:1 to once daily use of 300 mg of TDF or placebo. OUTCOME MEASURES: The primary safety endpoints were grade 2 or higher serum creatinine elevations (>2.0 mg/dl) for renal function, grade 3 or 4 aspartate aminotransferase or alanine aminotransferase elevations (>170 U/l) for hepatic function, and grade 3 or 4 phosphorus abnormalities (<1.5 mg/dl). The effectiveness endpoint was infection with HIV-1 or HIV-2. RESULTS: Study participants contributed 428 person-years of laboratory testing to the primary safety analysis. No significant differences emerged between treatment groups in clinical or laboratory safety outcomes. Study participants contributed 476 person-years of HIV testing to the primary effectiveness analysis, during which time eight seroconversions occurred. Two were diagnosed in participants randomized to TDF (0.86 per 100 person-years) and six in participants receiving placebo (2.48 per 100 person-years), yielding a rate ratio of 0.35 (95% confidence interval = 0.03-1.93), which did not achieve statistical significance. Owing to premature closures of the Cameroon and Nigeria study sites, the planned person-years of follow-up and study power could not be achieved. CONCLUSION: Daily oral use of TDF in HIV-uninfected women was not associated with increased clinical or laboratory adverse events. Effectiveness could not be conclusively evaluated because of the small number of HIV infections observed during the study.

Cloning and characterization of a cDNA of cro rI from the white pine blister rust fungus Cronartium ribicola.

White pine blister rust (WPBR) is caused by the fungus Cronartium ribicola which has five spore stages on two unrelated hosts, the five-needle pines and Ribes spp. Recently, during the molecular analysis of the proteins and genes involved in host-pathogen interaction, the WPBR fungal protein Cro rI was identified in infected white pine tissues. To further characterize Cro rI, an expression cDNA library from poly(A)(+) mRNA of C. ribicola axenic mycelial culture was constructed and immunoscreened and the cDNA was cloned. Sequence analysis indicated an open reading frame of 462 bases, which encodes a protein of 153 amino acid residues with a molecular mass of 16.7 kDa and a predicted isoelectric point (pI) of 8.93. Based on the N-terminal amino acid sequences of Cro rI, the secreted portion of Cro rI protein should be 136 amino acids long with several putative posttranslational modification sites and a molecular mass of 14.8 kDa. The predicted pI for the secreted portion was 9.34. The predicted N-terminal signal peptide was 17 amino acids long. The N-terminal 42-amino acid sequence of the predicted mature protein (secreted portion) was identical to the amino terminal sequence of Cro rI that was previously determined. Southern blot hybridizations indicated that the C. ribicola genome contained at least two copies of the cro rI gene. Isolation of the genomic PCR fragment, which was approximately 400 bp longer than the cDNA, and subsequent cloning and sequencing analyses confirmed that there were three introns within the coding regions. Western immunoblot analyses revealed that Cro rI protein accumulated in large amounts only in the infected white pine tissues while no trace was detectable in the alternate Ribes stage or the five different spores, suggesting a critical role of Cro rI in the haploid stage of the fungus (in pine). The translocation of Cro rI was only found to occur in cankered trees, and not in the young infected seedlings. The implications of Cro rI in pathogenesis are discussed.

An exploration of the relationship between youth assets and engagement in risky sexual behaviors.

PURPOSE: To examine the relationship between specific youth assets and adolescents' engagement in risky sexual behaviors, as measured by an Aggregate Sexual Risk score, and to specifically explore which youth assets and demographic variables were predictive of youth engagement in risky sexual intercourse. METHODS: A total of 2108 sexually active high school students attending public high schools in a southern state completed a self-report questionnaire that measured youth assets. Based upon responses to items measuring risk behaviors, an Aggregate Sexual Risk score was calculated for each student. Unconditional logistic regression and multivariate logistic regression analyses were conducted to examine the relationships between the assets and the Aggregate Risk Score. Four separate analyses (white females, white males, black females, and black males) were conducted. RESULTS: In general, the patterns in all four groups indicated that students who had an Aggregate Risk Score of > or = 3 (high risk) possessed less of the measured youth assets. The assets that were most significantly associated with engagement in risky sexual behaviors included self peer values regarding risky behaviors, quantity of other adult support, and youths' empathetic relationships. Thus, students who reported not having these assets were significantly more likely to engage in the risky sexual behaviors. CONCLUSIONS: Results underscore the relationship of specific youth assets to sexual risk behaviors. Health researcher and practitioners who work to prevent teen pregnancy and sexually transmitted infections among teenagers need to understand and acknowledge these factors within this population so that the assets can be built or strengthened.