Detection of significant climatic precession variability in early Pleistocene glacial cycles

Despite having a large influence on summer insolation, climatic precession is thought to account for little variance in early Pleistocene proxies of ice volume and deep-water temperature. Various mechanisms have been suggested to account for the dearth of precession variability, including meridional insolation gradients, interhemispheric cancellation of ice-volume changes, and antiphasing between the duration and intensity of summer insolation. We employ a method termed Empirical Nonlinear Orbital Fitting (ENOF) to estimate the amplitudes of obliquity and precession forcing in early Pleistocene proxies and their respective leads or lags relative to the timing of orbital variations. Analysis of a high-resolution North Atlantic benthic record, comprising data from IODP sites U1308 and U1313, indicates a larger precession contribution than previously recognized, with an average precession-to-obliquity amplitude ratio of 0.51 (0.30-0.76 95% confidence interval) in the rate-of-change of between 3 and 1 Ma. Averaged when eccentricity exceeds 0.05, this ratio rises to 1.18 (0.84-1.53). Additional support for precession's importance in the early Pleistocene comes from its estimated amplitude covarying with eccentricity, analyses of other benthic records yielding similar orbital amplitude ratios, and use of an orbitally-independent timescale also showing significant precession. Precession in phase with Northern Hemisphere summer intensity steadily intensifies throughout the Pleistocene, in agreement with its more common identification during the late Pleistocene. A Northern Hemisphere ice sheet and energy balance model run over the early Pleistocene predicts orbital amplitudes consistent with observations when a cooling commensurate with North Atlantic sea surface temperatures is imposed. These results provide strong evidence that glaciation is influenced by climatic precession during the late Pliocene and early Pleistocene, and are consistent with hypotheses that glaciation is controlled by Northern Hemisphere summer insolation

Considerations for preparing a randomized population health intervention trial: lessons from a South African–Canadian partnership to improve the health of health workers

Background: Community-based cluster-randomized controlled trials (RCTs) are increasingly being conducted to address pressing global health concerns. Preparations for clinical trials are well-described, as are the steps for multi-component health service trials. However, guidance is lacking for addressing the ethical and logistic challenges in (cluster) RCTs of population health interventions in low- and middle-income countries. Objective: We aimed to identify the factors that population health researchers must explicitly consider when planning RCTs within North–South partnerships. Design: We reviewed our experiences and identified key ethical and logistic issues encountered during the pre-trial phase of a recently implemented RCT. This trial aimed to improve tuberculosis (TB) and Human Immunodeficiency Virus (HIV) prevention and care for health workers by enhancing workplace assessment capability, addressing concerns about confidentiality and stigma, and providing onsite counseling, testing, and treatment. An iterative framework was used to synthesize this analysis with lessons taken from other studies. Results: The checklist of critical factors was grouped into eight categories: 1) Building trust and shared ownership; 2) Conducting feasibility studies throughout the process; 3) Building capacity; 4) Creating an appropriate information system; 5) Conducting pilot studies; 6) Securing stakeholder support, with a view to scale-up; 7) Continuously refining methodological rigor; and 8) Explicitly addressing all ethical issues both at the start and continuously as they arise. Conclusion: Researchers should allow for the significant investment of time and resources required for successful implementation of population health RCTs within North–South collaborations, recognize the iterative nature of the process, and be prepared to revise protocols as challenges emerge

Recovery of high mountain Alpine lakes after the eradication of introduced brook trout Salvelinus fontinalis using non-chemical methods

The final publication is available at Springer via http://dx.doi.org/10.1007/s10530-018-1867-0Fish stocking is a serious threat to originally fishless mountain lakes. We used non-chemical eradication methods (i.e. gillnetting and electrofishing) in four high mountain lakes in the Gran Paradiso National Park (Western Italian Alps) to eradicate alien brook trout Salvelinus fontinalis. Data of amphibians, macroinvertebrates, zooplankton, chlorophyll-a, nutrient concentrations, and water transparency were used as indicators of the recovery process. All treated lakes were returned to their original fishless condition in spite of their different sizes and habitat complexity, without permanent negative side-effects for native species. Several ecological indicators showed that many impacts of introduced fish can be reversed over a short time period following eradication. The present study adds to a still growing body of specialized literature on the recovery of habitats after the eradication of alien species and provides further evidence that physical eradication methods are effective and can be part of a more general strategy for the conservation of high mountain lake biota

Strengthening human immunodeficiency virus and tuberculosis prevention capacity among South African healthcare workers : a mixed methods study of a collaborative occupational health program

BACKGROUND : Insufficient training in infection control and occupational health among healthcare workers (HCWs) in countries with high human immunodeficiency virus (HIV) and tuberculosis (TB) burdens requires attention. We examined the effectiveness of a 1-year Certificate Program in Occupational Health and Infection Control conducted in Free State Province, South Africa in an international partnership to empower HCWs to become change agents to promote workplace-based HIV and TB prevention. METHODS : Questionnaires assessing reactions to the program and Knowledge, Attitudes, Skills, and Practices were collected pre-, mid-, and postprogram. Individual interviews, group project evaluations, and participant observation were also conducted. Quantitative data were analyzed using Wilcoxon signed-rank test. Qualitative data were thematically coded and analyzed using the Kirkpatrick framework. RESULTS : Participants recruited (n ¼ 32) were mostly female (81%) and nurses (56%). Pre-to-post-program mean scores improved in knowledge (12%, p ¼ 0.002) and skills/practices (14%, p ¼ 0.002). Preprogram attitude scores were high but did not change. Participants felt empowered and demonstrated attitudinal improvements regarding HIV, TB, infection control, and occupational health. Successful projects were indeed implemented. However, participants encountered considerable difficulties in trying to sustain improvement, due largely to lack of pre-existing knowledge and experience, combined with inadequate staffing and insufficient management support. CONCLUSION : Training is essential to strengthen HCWs’ occupational health and infection control knowledge, attitudes, skills, and practices, and workplace-based training programs such as this can yield impressive results. However, the considerable mentorship resources required for such programs and the substantial infrastructural supports needed for implementation and sustainability of improvements in settings without pre-existing experience in such endeavors should not be underestimated.Particular thanks are due to Karen Lockhart for her contributions throughout this study.We thank the participants of the Program, mentors, and researchers who aided in the Program, the Global Health Research Initiative (GHRI) for their funding, and the Free State Provincial Department of Health.http://www.e-shaw.orgam2018School of Health Systems and Public Health (SHSPH

Understanding the evolution of interspecies interactions in microbial communities

ISSN:0962-8436ISSN:1471-2970ISSN:0080-462

E-cigarette, cigarette, and cannabis use patterns as a function of sexual identity in a sample of Southern California young adults.

PurposeSexual minority young adults report greater cigarette and cannabis use. Emerging evidence suggests this trend may extend to e-cigarettes. The current study evaluated the relationship between sexual identity and prevalence of e-cigarette, cigarette, and cannabis use and whether such associations differ by gender.MethodsCross-sectional, regionally representative data of young adults (M[SD]age = 20.02 [0.60] years; n heterosexual = 1314; n bisexual = 77; n lesbian/gay = 28) from Wave III (2016) of the Southern California Children's Health Study were analyzed in 2019. Logistic regression analyses were conducted with sexual identity as the predictor and product use (never, prior, infrequent past 30-day [1-2 days], frequent past 30-day [3-5+ days]) as the outcome in separate models by substance (e-cigarettes, cigarettes, cannabis).ResultsBisexual individuals were the highest-risk sub-group for nearly all outcomes, with over five times the odds of reporting frequent past 30-day use for e-cigarettes (Odds Ratio [OR]: 6.68; 95% Confidence Interval [CI]: 2.80, 15.9), cigarettes (OR: 5.42; 95% CI: 2.37, 12.4), and cannabis (OR: 8.43; 95% CI: 4.40, 16.1) compared to heterosexual individuals. Although the sample size for lesbian/gay participants was small, bisexual (vs. lesbian/gay) participants also had greater odds of reporting prior use of nicotine products and frequent past 30-day cannabis use. A significant sexual identity × gender interaction emerged for lifetime cigarette use, wherein bisexual (vs. heterosexual) identity was only associated with greater odds of use for females (p < .01).ConclusionsSexual minority-related disparities in substance use among young adults appear to generalize to e-cigarettes, with bisexual young adults exhibiting especially high profiles of risk