Predicted global figures for plastic debris accumulation in the ocean surface layer range on the order of hundreds of thousands of metric tons, representing only a few percent of estimated annual ...emissions into the marine environment. The current accepted explanation for this difference is that positively buoyant macroplastic objects do not persist on the ocean surface. Subject to degradation into microplastics, the major part of the mass is predicted to have settled below the surface. However, we argue that such a simple emission-degradation model cannot explain the occurrence of decades-old objects collected by oceanic expeditions. We show that debris circulation dynamics in coastal environments may be a better explanation for this difference. The results presented here suggest that there is a significant time interval, on the order of several years to decades, between terrestrial emissions and representative accumulation in offshore waters. Importantly, our results also indicate that the current generation of secondary microplastics in the global ocean is mostly a result of the degradation of objects produced in the 1990s and earlier. Finally, we propose a series of future emission scenarios until 2050, discussing the necessity to rapidly reduce emissions and actively remove waste accumulated in the environment to mitigate further microplastic contamination in the global ocean.
Excess body adiposity, commonly expressed as body mass index (BMI), is a risk factor for many common adult cancers. Over the past decade, epidemiological data have shown that adiposity-cancer risk ...associations are specific for gender, site, geographical population, histological subtype and molecular phenotype. The biological mechanisms underpinning these associations are incompletely understood but need to take account of the specificities observed in epidemiology to better inform future prevention strategies.
Background The dose-response relation between physical activity and all-cause mortality is not well defined at present. We conducted a systematic review and meta-analysis to determine the association ...with all-cause mortality of different domains of physical activity and of defined increases in physical activity and energy expenditure.
Methods MEDLINE, Embase and the Cochrane Library were searched up to September 2010 for cohort studies examining all-cause mortality across different domains and levels of physical activity in adult general populations. We estimated combined risk ratios (RRs) associated with defined increments and recommended levels, using random-effects meta-analysis and dose-response meta-regression models.
Results Data from 80 studies with 1 338 143 participants (118 121 deaths) were included. Combined RRs comparing highest with lowest activity levels were 0.65 95% confidence interval (95% CI) 0.60-0.71 for total activity, 0.74 (95% CI 0.70-0.77) for leisure activity, 0.64 (95% CI 0.55-0.75) for activities of daily living and 0.83 (95% CI 0.71-0.97) for occupational activity. RRs per 1-h increment per week were 0.91 (95% CI 0.87-0.94) for vigorous exercise and 0.96 (95% CI 0.93-0.98) for moderate-intensity activities of daily living. RRs corresponding to 150 and 300 min/week of moderate to vigorous activity were 0.86 (95% CI 0.80-0.92) and 0.74 (95% CI 0.65-0.85), respectively. Mortality reductions were more pronounced in women.
Conclusion Higher levels of total and domain-specific physical activity were associated with reduced all-cause mortality. Risk reduction per unit of time increase was largest for vigorous exercise. Moderate-intensity activities of daily living were to a lesser extent beneficial in reducing mortality.
Switzerland is among the countries with the highest number of coronavirus disease-2019 (COVID-19) cases per capita in the world. There are likely many people with undetected SARS-CoV-2 infection ...because testing efforts are currently not detecting all infected people, including some with clinical disease compatible with COVID-19. Testing on its own will not stop the spread of SARS-CoV-2. Testing is part of a strategy. The World Health Organization recommends a combination of measures: rapid diagnosis and immediate isolation of cases, rigorous tracking and precautionary self-isolation of close contacts. In this article, we explain why the testing strategy in Switzerland should be strengthened urgently, as a core component of a combination approach to control COVID-19.
The infamous garbage patches on the surface of subtropical oceanic gyres are proof that plastic is polluting the ocean on an unprecedented scale. The fate of floating plastic debris 'trapped' in ...these gyres, however, remains largely unknown. Here, we provide the first evidence for the vertical transfer of plastic debris from the North Pacific Garbage Patch (NPGP) into the underlying deep sea. The numerical and mass concentrations of plastic fragments (500 µm to 5 cm in size) suspended in the water column below the NPGP follow a power law decline with water depth, reaching values <0.001 pieces/m
and <0.1 µg/m
in the deep sea. The plastic particles in the NPGP water column are mostly in the size range of particles that are apparently missing from the ocean surface and the polymer composition of plastic in the NPGP water column is similar to that of floating debris circulating in its surface waters (i.e. dominated by polyethylene and polypropylene). Our results further reveal a positive correlation between the amount of plastic debris at the sea surface and the depth-integrated concentrations of plastic fragments in the water column. We therefore conclude that the presence of plastics in the water column below the NPGP is the result of 'fallout' of small plastic fragments from its surface waters.
The evaluation of the credibility of results from a meta-analysis has become an important part of the evidence synthesis process. We present a methodological framework to evaluate confidence in the ...results from network meta-analyses, Confidence in Network Meta-Analysis (CINeMA), when multiple interventions are compared.
CINeMA considers 6 domains: (i) within-study bias, (ii) reporting bias, (iii) indirectness, (iv) imprecision, (v) heterogeneity, and (vi) incoherence. Key to judgments about within-study bias and indirectness is the percentage contribution matrix, which shows how much information each study contributes to the results from network meta-analysis. The contribution matrix can easily be computed using a freely available web application. In evaluating imprecision, heterogeneity, and incoherence, we consider the impact of these components of variability in forming clinical decisions.
Via 3 examples, we show that CINeMA improves transparency and avoids the selective use of evidence when forming judgments, thus limiting subjectivity in the process. CINeMA is easy to apply even in large and complicated networks.
We aimed to develop an in-depth understanding of quality criteria for scholarly journals by analyzing journals and publishers indexed in blacklists of predatory journals and whitelists of legitimate ...journals and the lists' inclusion criteria. To quantify content overlaps between blacklists and whitelists, we employed the Jaro-Winkler string metric. To identify topics addressed by the lists' inclusion criteria and to derive their concepts, we conducted qualitative coding. We included two blacklists (Beall's and Cabells Scholarly Analytics') and two whitelists (the Directory of Open Access Journals' and Cabells Scholarly Analytics'). The number of journals per list ranged from 1,404 to 12,357, and the number of publishers ranged from 473 to 5,638. Seventy-two journals and 42 publishers were included in both a blacklist and a whitelist. Seven themes were identified in the inclusion criteria: (i) peer review; (ii) editorial services; (iii) policy; (iv) business practices; (v) publishing, archiving, and access; (vi) website; and (vii) indexing and metrics. Business practices accounted for almost half of the blacklists' criteria, whereas whitelists gave more emphasis to criteria related to policy. Criteria could be allocated to four concepts: (i) transparency, (ii) ethics, (iii) professional standards, and (iv) peer review and other services. Whitelists gave most weight to transparency. Blacklists focused on ethics and professional standards. Whitelist criteria were easier to verify than those used in blacklists. Both types gave little emphasis to quality of peer review. Overall, the results show that there is overlap of journals and publishers between blacklists and whitelists. Lists differ in their criteria for quality and the weight given to different dimensions of quality. Aspects that are central but difficult to verify receive little attention.
Predatory journals are spurious scientific outlets that charge fees for editorial and publishing services that they do not provide. Their lack of quality assurance of published articles increases the risk that unreliable research is published and thus jeopardizes the integrity and credibility of research as a whole. There is increasing awareness of the risks associated with predatory publishing, but efforts to address this situation are hampered by the lack of a clear definition of predatory outlets. Blacklists of predatory journals and whitelists of legitimate journals have been developed but not comprehensively examined. By systematically analyzing these lists, this study provides insights into their utility and delineates the different notions of quality and legitimacy in scholarly publishing used. This study contributes to a better understanding of the relevant concepts and provides a starting point for the development of a robust definition of predatory journals.
Summary Background Excess bodyweight, expressed as increased body-mass index (BMI), is associated with the risk of some common adult cancers. We did a systematic review and meta-analysis to assess ...the strength of associations between BMI and different sites of cancer and to investigate differences in these associations between sex and ethnic groups. Methods We did electronic searches on Medline and Embase (1966 to November 2007), and searched reports to identify prospective studies of incident cases of 20 cancer types. We did random-effects meta-analyses and meta-regressions of study-specific incremental estimates to determine the risk of cancer associated with a 5 kg/m2 increase in BMI. Findings We analysed 221 datasets (141 articles), including 282 137 incident cases. In men, a 5 kg/m2 increase in BMI was strongly associated with oesophageal adenocarcinoma (RR 1·52, p<0·0001) and with thyroid (1·33, p=0·02), colon (1·24, p<0·0001), and renal (1·24, p <0·0001) cancers. In women, we recorded strong associations between a 5 kg/m2 increase in BMI and endometrial (1·59, p<0·0001), gallbladder (1·59, p=0.04), oesophageal adenocarcinoma (1·51, p<0·0001), and renal (1·34, p<0·0001) cancers. We noted weaker positive associations (RR <1·20) between increased BMI and rectal cancer and malignant melanoma in men; postmenopausal breast, pancreatic, thyroid, and colon cancers in women; and leukaemia, multiple myeloma, and non-Hodgkin lymphoma in both sexes. Associations were stronger in men than in women for colon (p<0·0001) cancer. Associations were generally similar in studies from North America, Europe and Australia, and the Asia–Pacific region, but we recorded stronger associations in Asia–Pacific populations between increased BMI and premenopausal (p=0·009) and postmenopausal (p=0·06) breast cancers. Interpretation Increased BMI is associated with increased risk of common and less common malignancies. For some cancer types, associations differ between sexes and populations of different ethnic origins. These epidemiological observations should inform the exploration of biological mechanisms that link obesity with cancer.
Summary Surgical site infections (SSIs) are among the most preventable health-care-associated infections and are a substantial burden to health-care systems and service payers worldwide in terms of ...patient morbidity, mortality, and additional costs. SSI prevention is complex and requires the integration of a range of measures before, during, and after surgery. No international guidelines are available and inconsistencies in the interpretation of evidence and recommendations of national guidelines have been identified. Given the burden of SSIs worldwide, the numerous gaps in evidence-based guidance, and the need for standardisation and a global approach, WHO decided to prioritise the development of evidence-based recommendations for the prevention of SSIs. The guidelines take into account the balance between benefits and harms, the evidence quality, cost and resource use implications, and patient values and preferences. On the basis of systematic literature reviews and expert consensus, we present 13 recommendations on preoperative preventive measures.
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