Wax "Tails" Enable Planthopper Nymphs to Self-Right Midair and Land on Their Feet.

The striking appearance of wax 'tails'-posterior wax projections on planthopper nymphs-has captivated entomologists and naturalists alike. Despite their intriguing presence, the functional roles of these formations remain largely unexplored. This study leverages high-speed imaging to uncover the biomechanical implications of wax structures in the aerial dynamics of planthopper nymphs (Ricania sp.). We quantitatively demonstrate that removing wax tails significantly increases body rotations during jumps. Specifically, nymphs without wax undergo continuous rotations, averaging 4.2 ± 1.8 per jump, in contrast to wax-intact nymphs, who do not complete a full rotation, averaging only 0.7 ± 0.2 per jump. This along with significant reductions in angular and translational velocity from takeoff to landing suggest that aerodynamic drag forces on wax structures effectively counteract rotation. These stark differences in body rotation correlate with landing success: Nymphs with wax intact achieve a near perfect landing rate of 98.5%, while those without wax manage only a 35.5% success rate. Jump trajectory analysis reveals that wax-intact jumps transition from parabolic to asymmetric shapes at higher takeoff velocities and show a significantly greater reduction in velocity from takeoff to landing compared to wax-removed jumps, demonstrating how wax structures help nymphs achieve more stable and controlled descents. Our findings confirm the aerodynamic self-righting functionality of wax tails in stabilizing planthopper nymph landings, advancing our understanding of the complex relationship between wax morphology and aerial maneuverability, with broader implications for wingless insect aerial adaptations and bioinspired robotics.

Wax "tails" enable planthopper nymphs to self-right midair and land on their feet.

The striking appearance of wax 'tails' - posterior wax projections on planthopper nymphs - has captivated entomologists and naturalists alike. Despite their intriguing presence, the functional roles of these structures remain largely unexplored. This study leverages high-speed imaging to uncover the biomechanical implications of these wax formations in the aerial dynamics of planthopper nymphs (Ricania sp.). We quantitatively demonstrate that removing wax tails significantly increases body rotations during jumps. Specifically, nymphs without wax projections undergo continuous rotations, averaging 4.3 ± 1.9 per jump, in contrast to wax-intact nymphs, who narrowly complete a full rotation, averaging only 0.7 ± 0.2 per jump. This suggests that wax structures effectively counteract rotation through aerodynamic drag forces. These stark differences in body rotation correlate with landing success: nymphs with wax intact achieve a near perfect landing rate of 98.5%, while those without wax manage only a 35.5% success rate. Jump trajectory analysis reveals transitions from parabolic to Tartaglia shapes at higher take-off velocities for wax-intact nymphs, illustrating how wax structures assist nymphs in achieving stable, controlled descents. Our findings confirm the aerodynamic self-righting functionality of wax tails in stabilizing planthopper landings, advancing our understanding of the complex interplay between wax morphology and aerial maneuverability, with broader implications for the evolution of flight in wingless insects and bioinspired robotics.

Knowledge, attitudes, and practices around hand drying in public bathrooms during the COVID-19 pandemic in the United States.

Hand drying is the critical, final step of handwashing. A cross-sectional survey of U.S. adults assessed self-reported hand drying practices in public bathrooms and found increased preference for using electric hand dryers, wiping hands on clothing, and shaking hands and decreased preference for using paper towels during the COVID-19 pandemic relative to before. Respondents expressed concerns about contacting SARS-CoV-2 when touching surfaces in public bathrooms which may be influencing self-reported drying method preference.

Human Immunodeficiency Virus Prevention for People Who Use Drugs: Overview of Reviews and the ICOS of PICOS.

BACKGROUND: This article summarizes the results from systematic reviews of human immunodeficiency virus (HIV) prevention interventions for people who use drugs (PWUD). We performed an overview of reviews, meta-analysis, meta-epidemiology, and PROSPERO Registration CRD42017070117. METHODS: We conducted a comprehensive systematic literature search using the Centers for Disease Control and Prevention HIV/AIDS Prevention Research Synthesis Project database to identify quantitative systematic reviews of HIV public heath interventions with PWUD published during 2002-2017. We recombined results of US studies across reviews to quantify effects on HIV infections, continuum of HIV care, sexual risk, and 5 drug-related outcomes (sharing injection equipment, injection frequency, opioid use, general drug use, and participation in drug treatment). We conducted summary meta-analyses separately for reviews of randomized controlled trials (RCTs) and quasi-experiments. We stratified effects by 5 intervention types: behavioral-psychosocial (BPS), syringe service programs (SSP), opioid agonist therapy (OAT), financial and scheduling incentives (FSI), and case management (CM). RESULTS: We identified 16 eligible reviews including >140 US studies with >55 000 participants. Summary effects among US studies were significant and favorable for 4 of 5 outcomes measured under RCT (eg, reduced opioid use; odds ratio [OR] = 0.70, confidence interval [CI] = 0.56-0.89) and all 6 outcomes under quasi-experiments (eg, reduced HIV infection [OR = 0.42, CI = 0.27-0.63]; favorable continuum of HIV care [OR = 0.68, CI = 0.53-0.88]). Each intervention type showed effectiveness on 1-6 outcomes. Heterogeneity was moderate to none for RCT but moderate to high for quasi-experiments. CONCLUSIONS: Behavioral-psychosocial, SSP, OAT, FSI, and CM interventions are effective in reducing risk of HIV and sequelae of injection and other drug use, and they have a continuing role in addressing the opioid crisis and Ending the HIV Epidemic.

HIV Prevention Research on Men Who Have Sex With Men: A Scoping Review of Systematic Reviews, 1988-2017.

In the United States, men who have sex with men (MSM) are disproportionately affected by HIV. To identify research gaps and inform HIV prevention for MSM, we conducted a scoping review of systematic reviews using CDC's Prevention Research Synthesis database. Eligibility criteria comprised English-language systematic reviews focused on HIV prevention for MSM, published during 1988-2017, and included at least one U.S. primary study. We coded data type, subpopulations, topics, and key findings. To assess study quality, we used the Assessment of Multiple Systematic Reviews (AMSTAR). Among 129 relevant systematic reviews, study quality was high or moderate for 63%. Most common topics were sexual behavior and disease vulnerability. The most frequently mentioned MSM subgroups were HIV-positive, Black or African American, and young. Research gaps include Hispanic/Latino MSM, pre-exposure prophylaxis (PrEP), treatment as prevention, social determinants of health, health disparities, syndemics, and protective factors for sexual health.

A Rapid Review of eHealth Interventions Addressing the Continuum of HIV Care (2007-2017).

National HIV prevention goals call for interventions that address Continuum of HIV Care (CoC) for persons living with HIV. Electronic health (eHealth) can leverage technology to rapidly develop and disseminate such interventions. We conducted a qualitative review to synthesize (a) technology types, (b) CoC outcomes, (c) theoretical frameworks, and (d) behavior change mechanisms. This rapid review of eHealth, HIV-related articles (2007-2017) focused on technology-based interventions that reported CoC-related outcomes. Forty-five studies met inclusion criteria. Mobile texting was the most commonly reported technology (44.4%, k = 20). About 75% (k = 34) of studies showed proven or preliminary efficacy for improving CoC-related outcomes. Most studies (60%, k = 27) focused on medication adherence; 20% (k = 9) measured virologic suppression. Many eHealth interventions with preliminary or proven efficacy relied on mobile technology and integrated knowledge/cognition as behavior change mechanisms. This review identified gaps in development and application of eHealth interventions regarding CoC.

Wrinkling and folding of thin films by viscous stress.

We examine the buckling of a thin elastic film floating on a viscous liquid layer which is itself supported on a prestretched rubber sheet. Releasing the prestretch in the rubber induces a viscous stress in the liquid, which in turn induces a compressive stress in the elastic film, leading to buckling. Unlike many previous studies on wrinkling of floating films, the buckling process in the present study is dominated by viscous effects whereas gravitational effects are negligible. An approximate shear lag model predicts the evolution of the stress profile in the unbuckled film that depends on three parameters: the rate at which the prestretch is released, the thickness of the liquid layer, and the length of the elastic film. A linear perturbation analysis is developed to predict the wavelength of wrinkles. Numerical simulations are conducted to predict nonlinear evolution of the wrinkle wavelength and amplitude. Experiments using elastic polymer films and viscous polymer liquids show trends that are qualitatively consistent with the predictions although quantitatively, the experimentally-observed wrinkle wavelengths are longer than predicted. Although this article is focused only on small-strain wrinkling behavior, we show that application of large nominal strains (on the order of 100%) leads to sharply localized folds. Thus this approach may be useful for developing buckled features with high aspect ratio on surfaces.

Promotional tone in reviews of menopausal hormone therapy after the Women's Health Initiative: an analysis of published articles.

BACKGROUND: Even after the Women's Health Initiative (WHI) found that the risks of menopausal hormone therapy (hormone therapy) outweighed benefit for asymptomatic women, about half of gynecologists in the United States continued to believe that hormones benefited women's health. The pharmaceutical industry has supported publication of articles in medical journals for marketing purposes. It is unknown whether author relationships with industry affect promotional tone in articles on hormone therapy. The goal of this study was to determine whether promotional tone could be identified in narrative review articles regarding menopausal hormone therapy and whether articles identified as promotional were more likely to have been authored by those with conflicts of interest with manufacturers of menopausal hormone therapy. METHODS AND FINDINGS: We analyzed tone in opinion pieces on hormone therapy published in the four years after the estrogen-progestin arm of the WHI was stopped. First, we identified the ten authors with four or more MEDLINE-indexed reviews, editorials, comments, or letters on hormone replacement therapy or menopausal hormone therapy published between July 2002 and June 2006. Next, we conducted an additional search using the names of these authors to identify other relevant articles. Finally, after author names and affiliations were removed, 50 articles were evaluated by three readers for scientific accuracy and for tone. Scientific accuracy was assessed based on whether or not the findings of the WHI were accurately reported using two criteria: (1) Acknowledgment or lack of denial of the risk of breast cancer diagnosis associated with hormone therapy, and (2) acknowledgment that hormone therapy did not benefit cardiovascular disease endpoints. Determination of promotional tone was based on the assessment by each reader of whether the article appeared to promote hormone therapy. Analysis of inter-rater consistency found moderate agreement for scientific accuracy (κ=0.57) and substantial agreement for promotional tone (κ=0.65). After discussion, readers found 86% of the articles to be scientifically accurate and 64% to be promotional in tone. Themes that were common in articles considered promotional included attacks on the methodology of the WHI, arguments that clinical trial results should not guide treatment for individuals, and arguments that observational studies are as good as or better than randomized clinical trials for guiding clinical decisions. The promotional articles we identified also implied that the risks associated with hormone therapy have been exaggerated and that the benefits of hormone therapy have been or will be proven. Of the ten authors studied, eight were found to have declared payment for speaking or consulting on behalf of menopausal hormone manufacturers or for research support (seven of these eight were speakers or consultants). Thirty of 32 articles (90%) evaluated as promoting hormone therapy were authored by those with potential financial conflicts of interest, compared to 11 of 18 articles (61%) by those without such conflicts (p=0.0025). Articles promoting the use of menopausal hormone therapy were 2.41 times (95% confidence interval 1.49-4.93) as likely to have been authored by authors with conflicts of interest as by authors without conflicts of interest. In articles from three authors with conflicts of interest some of the same text was repeated word-for-word in different articles. CONCLUSION: There may be a connection between receiving industry funding for speaking, consulting, or research and the publication of promotional opinion pieces on menopausal hormone therapy.