The influence of decision-making in tree ring-based climate reconstructions.

Tree-ring chronologies underpin the majority of annually-resolved reconstructions of Common Era climate. However, they are derived using different datasets and techniques, the ramifications of which have hitherto been little explored. Here, we report the results of a double-blind experiment that yielded 15 Northern Hemisphere summer temperature reconstructions from a common network of regional tree-ring width datasets. Taken together as an ensemble, the Common Era reconstruction mean correlates with instrumental temperatures from 1794-2016 CE at 0.79 (p < 0.001), reveals summer cooling in the years following large volcanic eruptions, and exhibits strong warming since the 1980s. Differing in their mean, variance, amplitude, sensitivity, and persistence, the ensemble members demonstrate the influence of subjectivity in the reconstruction process. We therefore recommend the routine use of ensemble reconstruction approaches to provide a more consensual picture of past climate variability.

Volcanic suppression of Nile summer flooding triggers revolt and constrains interstate conflict in ancient Egypt.

Volcanic eruptions provide tests of human and natural system sensitivity to abrupt shocks because their repeated occurrence allows the identification of systematic relationships in the presence of random variability. Here we show a suppression of Nile summer flooding via the radiative and dynamical impacts of explosive volcanism on the African monsoon, using climate model output, ice-core-based volcanic forcing data, Nilometer measurements, and ancient Egyptian writings. We then examine the response of Ptolemaic Egypt (305-30 BCE), one of the best-documented ancient superpowers, to volcanically induced Nile suppression. Eruptions are associated with revolt onset against elite rule, and the cessation of Ptolemaic state warfare with their great rival, the Seleukid Empire. Eruptions are also followed by socioeconomic stress with increased hereditary land sales, and the issuance of priestly decrees to reinforce elite authority. Ptolemaic vulnerability to volcanic eruptions offers a caution for all monsoon-dependent agricultural regions, presently including 70% of world population.The degree to which human societies have responded to past climatic changes remains unclear. Here, using a novel combination of approaches, the authors show how volcanically-induced suppression of Nile summer flooding led to societal unrest in Ptolemaic Egypt (305-30 BCE).

Screening for Obstructive Sleep Apnea in Adults: Evidence Report and Systematic Review for the US Preventive Services Task Force.

Importance: Many adverse health outcomes are associated with obstructive sleep apnea (OSA). Objective: To review primary care-relevant evidence on screening adults for OSA, test accuracy, and treatment of OSA, to inform the US Preventive Services Task Force. Data Sources: MEDLINE, Cochrane Library, EMBASE, and trial registries through October 2015, references, and experts, with surveillance of the literature through October 5, 2016. Study Selection: English-language randomized clinical trials (RCTs); studies evaluating accuracy of screening questionnaires or prediction tools, diagnostic accuracy of portable monitors, or association between apnea-hypopnea index (AHI) and health outcomes among community-based participants. Data Extraction and Synthesis: Two investigators independently reviewed abstracts and full-text articles. When multiple similar studies were available, random-effects meta-analyses were conducted. Main Outcomes and Measures: Sensitivity, specificity, area under the curve (AUC), AHI, Epworth Sleepiness Scale (ESS) scores, blood pressure, mortality, cardiovascular events, motor vehicle crashes, quality of life, and harms. Results: A total of 110 studies were included (N = 46 188). No RCTs compared screening with no screening. In 2 studies (n = 702), the screening accuracy of the multivariable apnea prediction score followed by home portable monitor testing for detecting severe OSA syndrome (AHI ≥30 and ESS score >10) was AUC 0.80 (95% CI, 0.78 to 0.82) and 0.83 (95% CI, 0.77 to 0.90), respectively, but the studies oversampled high-risk participants and those with OSA and OSA syndrome. No studies prospectively evaluated screening tools to report calibration or clinical utility for improving health outcomes. Meta-analysis found that continuous positive airway pressure (CPAP) compared with sham was significantly associated with reduction of AHI (weighted mean difference [WMD], -33.8 [95% CI, -42.0 to -25.6]; 13 trials, 543 participants), excessive sleepiness assessed by ESS score (WMD, -2.0 [95% CI, -2.6 to -1.4]; 22 trials, 2721 participants), diurnal systolic blood pressure (WMD, -2.4 points [95% CI, -3.9 to -0.9]; 15 trials, 1190 participants), and diurnal diastolic blood pressure (WMD, -1.3 points [95% CI, -2.2 to -0.4]; 15 trials, 1190 participants). CPAP was associated with modest improvement in sleep-related quality of life (Cohen d, 0.28 [95% CI, 0.14 to 0.42]; 13 trials, 2325 participants). Mandibular advancement devices (MADs) and weight loss programs were also associated with reduced AHI and excessive sleepiness. Common adverse effects of CPAP and MADs included oral or nasal dryness, irritation, and pain, among others. In cohort studies, there was a consistent association between AHI and all-cause mortality. Conclusions and Relevance: There is uncertainty about the accuracy or clinical utility of all potential screening tools. Multiple treatments for OSA reduce AHI, ESS scores, and blood pressure. Trials of CPAP and other treatments have not established whether treatment reduces mortality or improves most other health outcomes, except for modest improvement in sleep-related quality of life.

Perceptions and plans for prevention of Ebola: results from a national survey.

BACKGROUND: Literature suggests that Americans may have higher levels of perceived threat to Ebola than are warranted. METHODS: We surveyed 1018 U.S. adults from a nationally representative Internet panel about their knowledge, perceived threat, and behavioral intentions during the 2014 Ebola outbreak. RESULTS: Eighty-six percent of respondents knew that Ebola could be transmitted through blood and bodily fluids. However, a large percentage had some inaccurate knowledge and 19 % believed Ebola would spread to the U.S. Respondents favored mandatory quarantine (63 %) and travel bans (55 %). Confidence in the ability of the media and government to accurately report on or prevent a U.S. epidemic was low. Fifty-two percent intended to engage in behaviors such as avoiding public transportation. DISCUSSION: Despite low perceived susceptibility, half intended to engage in behaviors to prevent transmission and large numbers favored policies not currently recommended by health officials. The extreme nature of Ebola virus likely motivated people to engage in behaviors and favor policies that were not necessary given the low risk of transmission in the U.S. CONCLUSIONS: Health officials should ensure the public has accurate information about Ebola and bolster confidence in the government's ability to control infectious diseases in case of a future outbreak in the U.S.

Financial conflict of interest disclosure and voting patterns at Food and Drug Administration Drug Advisory Committee meetings.

CONTEXT: In January 2002, the US Food and Drug Administration (FDA) issued a draft guidance requiring more detailed financial conflict of interest disclosure at advisory committee meetings. OBJECTIVES: To characterize financial conflict disclosures at drug-related meetings, and to assess the relationship between conflicts and voting behavior at meetings that considered specific products. DESIGN AND SETTING: Cross-sectional study using agendas and transcripts from all FDA Drug Advisory Committee meetings (2001-2004) listed on the FDA Web site. MAIN OUTCOME MEASURES: Conflict rates, type, and size. The relationship between having a conflict and voting in favor of the index drug was described for each voter using Mantel-Haenszel relative risks and Monte Carlo simulations; Spearman rho was used for a meeting-level analysis comparing rates of conflict with voting patterns. The impact of the removal of persons with conflicts of interest on the vote margins was also evaluated. RESULTS: A total of 221 meetings held by 16 advisory committees were included in the study. In 73% of the meetings, at least 1 advisory committee member or voting consultant disclosed a conflict; only 1% of advisory committee members were recused. For advisory committee members (n = 1957) and voting consultants combined (n = 990), 28% (n = 825) disclosed a conflict. The most commonly specified conflicts were consulting arrangements, contracts/grants, and investments. Nineteen percent of consulting arrangements involved over 10,000 dollars, 23% of contracts/grants exceeded 100,000 dollars, and 30% of investments were over 25,000 dollars. The meeting-level analysis did not show a statistically significant relationship between conflict rates ("index conflict," "competitor conflict," or "any conflict") and voting patterns, but a weak, statistically significant positive relationship was apparent for competitor conflict and any conflict in the Mantel-Haenszel analyses. The Monte Carlo analyses produced similar findings in the competitor conflict analysis only. In all 3 conflict categories, the exclusion of advisory committee members and voting consultants with conflicts would have produced margins less favorable to the index drug in the majority of meetings, but this would not have changed whether the majority favored or opposed the drug. CONCLUSIONS: Disclosures of conflicts of interest at drug advisory committee meetings are common, often of considerable monetary value, and rarely result in recusal of advisory committee members. A weak relationship between certain types of conflicts and voting behaviors was detected, but excluding advisory committee members and voting consultants with conflicts would not have altered the overall vote outcome at any meeting studied.