Single particle analysis of the accumulation mode aerosol over the northeast Amazonian tropical rain forest, Surinam, South America

International audienceSingle particle analysis of aerosols particles larger than 0.2 ?m diameter was performed on 24 samples collected over Surinam tropical rain forest and in the adjacent marine boundary layer (MBL) during the LBA-CLAIRE 98 campaign in March 1998. Elemental composition and morphology of 2308 particles was determined using SEM-EDX. The aerosol particles were divided into seven groups according to their chemical composition: organic particles, mineral dust, aged mineral dust, sea salt, aged sea salt, Ca-rich, and biogenic aerosol. However the organic material in aerosol particles cannot be identified directly by SEM-EDX, we present indirect method of detection of organic material using this technique. Samples were further divided with respect to the distinct atmospheric layers present in the tropical troposphere including MBL, continental mixed layer, cloud convective layer, free troposphere and region of deep convection outflow. The organic and mineral dust particles are two major groups observed over the rainforest. In the MBL also sea salt particles represented a large fraction between 15 and 27%. The organic particles control much of the chemical characteristic of the aerosol in the continental tropical troposphere. Their abundance ranged from less than 20% in the MBL to more than 90% in the free troposphere between 4.5- and 12.6-km altitude. During the transport of the air masses from the MBL over the rain forest, fraction of organic aerosol particles more than doubled, reaching 40?60% in the continental boundary layer. This increase was attributed to direct emissions of biogenic aerosols from the tropical vegetation. The high fraction of the organic accumulation mode particles in the upper tropical troposphere could be a good indicator for the air masses originated over the tropical rain forest

Weight gain after smoking cessation and risk of major chronic diseases and mortality

Importance: Smoking cessation is frequently followed by weight gain; however, whether weight gain after quitting reduces the health benefits of quitting is unclear. Objective: To examine the association between weight change after smoking cessation and the risk of cardiovascular diseases (CVD), type 2 diabetes, cancer, chronic obstructive pulmonary disease (COPD), and all-cause mortality. Design, Setting, and Participants: This cohort study analyzed data from a nationally representative sample of Australian adults aged 18 years or older who were studied between 2006 and 2014. Smoking status and anthropometric measurements were self-reported annually. Cox proportional hazards regressions were used to determine the hazard ratios (HRs) for the association between changes in weight and body mass index (BMI) and the risk of CVD, type 2 diabetes, cancer, COPD, and mortality. Data were analyzed in January 2019. Exposures: Annual self-reported smoking status; years since quitting. Main Outcomes and Measures: Weight gain after quitting, incident CVD, type 2 diabetes, cancer, COPD, and all-cause mortality. Results: Of a total 16663 participants (8082 men and 8581 women; mean [SD] age, 43.7 [16.3] years), those who quit smoking had greater increases in weight (mean difference [MD], 3.14 kg; 95% CI, 1.39-4.87) and BMI (MD, 0.82; 95% CI, 0.21-1.44) than continuing smokers. Compared with continuing smokers, the HRs for death were 0.50 (95% CI, 0.36-0.68) among quitters who lost weight, 0.79 (95% CI, 0.51-0.98) among quitters without weight change, 0.33 (95% CI, 0.21-0.51) among quitters who gained 0.1 to 5.0 kg, 0.24 (95% CI, 0.11-0.53) among quitters who gained 5.1 to 10 kg, and 0.36 (95% CI, 0.16-0.82) among quitters who gained more than 10 kg. The HRs for death were 0.61 (95% CI, 0.45-0.83) among quitters who lost BMI, 0.86 (95% CI, 0.51-1.44) among quitters without change in BMI, 0.32 (95% CI, 0.21-0.50) among quitters who gained up to 2 in BMI, and 0.26 (95% CI, 0.16-0.45) among quitters who gained more than 2 in BMI. Conclusions and Relevance: This cohort study found that smoking cessation was accompanied by a substantial weight gain; however, this was not associated with an increased risk of chronic diseases or an attenuation of the mortality benefit of cessation

Governments' policy response to drought in Eswatini and Lesotho : a systematic review of the characteristics, comprehensiveness, and quality of existing policies to improve community resilience to drought hazards

The southern African kingdoms of Eswatini and Lesotho experience recurrent drought-induced disasters. Policies have been enacted, but no attempt has been made to synthesise the effects on disaster resilience. This review analyses the characteristics, quality, and comprehensiveness of drought-resilience policies in Eswatini and Lesotho. We have systematically reviewed public policies that shape responses to disaster resilience published between 1 January 1980 and 30 June 2019. A combination of keywords was used to search electronic bibliographic databases, multidisciplinary databases, key organisational websites, and the first 20 pages of Google for policies that addressed disaster and/or drought resilience. Identified documents were downloaded into an EndNote database and screened for eligibility using predetermined criteria. The logic of events framework was used for quality assessment, and a metaethnographic approach was applied for data synthesis. Three broad categories of characteristics, thematic outcomes and quality, and comprehensiveness of policy documents emerged and are presented. Policy responses contributing to disaster resilience were found in n = 32 out of 13,700 documents. Three (n = 3/32) policies were statutory, and the rest were nonstatutory. Eleven (n = 11/32) were assessed to be of high quality. Policy responses relating to drought resilience focused on reducing vulnerability to recurrent disasters; promoting drought and climate change adaptation; improving agriculture and food security; safeguarding cultural heritage; and preventing gender inequality and gender-based violence as well as improving disaster governance. However, the construct of drought resilience was not strongly articulated as a major policy goal across policy documents. There is an urgent need to promote better understanding of drought resilience in order to motivate policymakers to steer away from reactive interventions and position resilience as a major national policy goal in both countries to expedite inclusive growth and safeguard development gains and the health and wellbeing of the majority of their populations who are rural-based populations

Frailty Confers High Mortality Risk across Different Populations:Evidence from an Overview of Systematic Reviews and Meta-Analyses

We performed an overview of systematic reviews and meta-analyses to summarize available data regarding the association between frailty and all-cause mortality. Medline, Embase, CINAHL, Web of Science, PsycINFO, and AMED (Allied and Complementary Medicine) databases were searched until February 2020 for meta-analyses examining the association between frailty and all-cause mortality. The AMSTAR2 checklist was used to evaluate methodological quality. Frailty exposure and the risk of all-cause mortality (hazard ratio [HR] or relative risk [RR]) were displayed in forest plots. We included 25 meta-analyses that pooled data from between 3 and 20 studies. The number of participants included in these meta-analyses ranged between 500,000. Overall, 56%, 32%, and 12% of studies were rated as of moderate, low, and critically low quality, respectively. Frailty was associated with increased risk of all-cause mortality in 24/24 studies where the HR/RRs ranged from 1.35 [95% confidence interval (CI) 1.05-1.74] (patients with diabetes) to 7.95 [95% CI 4.88-12.96] (hospitalized patients). The median HR/RR across different meta-analyses was 1.98 (interquartile range 1.65-2.67). Pre-frailty was associated with a significantly increased risk of all-cause mortality in 7/7 studies with the HR/RR ranging from 1.09 to 3.65 (median 1.51, IQR 1.38-1.73). These data suggest that interventions to prevent frailty and pre-frailty are needed

Lifestyle interventions for type 2 diabetes management among migrants and ethnic minorities living in industrialized countries : a systematic review and meta-analyses

The objective of this systematic review was to determine the effectiveness of lifestyle interventions to improve the management of type 2 diabetes mellitus (T2DM) among migrants and ethnic minorities. Major searched databases included MEDLINE (via PubMed), EMBASE (via Ovid) and CINAHL. The selection of studies and data extraction followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. In the meta-analysis, significant heterogeneity was detected among the studies (I 2 >50%), and hence a random effects model was used. Subgroup analyses were performed to compare the effect of lifestyle interventions according to intervention approaches (peer-led vs community health workers (CHWs)-led). A total of 17 studies were included in this review which used interventions delivered by CHWs or peer supporters or combination of both. The majority of the studies assessed effectiveness of key primary (hemoglobin (HbA1c), lipids, fasting plasma glucose) and secondary outcomes (weight, body mass index, blood pressure, physical activity, alcohol consumption, tobacco smoking, food habits and healthcare utilization). Meta-analyses showed lifestyle interventions were associated with a small but statistically significant reduction in HbA1c level (-0.18%; 95% CI-0.32% to-0.04%, p=0.031). In subgroup analyses, the peer-led interventions showed relatively better HbA1c improvement than CHW-led interventions, but the difference was not statistically significant (p=0.379). Seven studies presented intervention costs, which ranged from US$131 to US$461 per participant per year. We conclude that lifestyle interventions using either CHWs or peer supporters or a combination of both have shown modest effectiveness for T2DM management among migrants of different background and origin and ethnic minorities. The evidence base is promising in terms of developing culturally appropriate, clinically sound and cost-effective intervention approaches to respond to the growing and diverse migrants and ethnic minorities affected by diabetes worldwide

Trends and impact factors of mental health service utilization among resettled humanitarian migrants in Australia : findings from the BNLA cohort study

Resettled humanitarian migrants (HMs) have high levels of mental disorders, but factors associated with the utilization of mental health services (MHS) are poorly understood. We aimed to explore trends and impact factors of MHS utilization among HMs in the process of resettlement in Australia. A total of 2311 HMs from the 1st (2013), 3rd, and 5th (2018) waves of a national cohort study were included. MHS utilization in the past year was assessed by two indicators: having MHS contacts and the frequency of MHS contacts. Trends were identified by Cochran-Armitage tests, and generalized linear mixed models and ordered logistic models were fitted to explore impact factors of MHS utilization. The proportion of having MHS contacts significantly rose from 13.0% to 29.4% over the five years. MHS utilization was mainly driven by perceived needs, such as post-traumatic stress disorders and the degree of post-migration stress. Unemployment and strong belongingness to the local community were also associated with having MHS contacts. No significant gender difference was found in having MHS contacts but females tended to contact MHS more frequently. Resettled HMs have a persistent dilemma of high mental illness prevalence and MHS underutilization. Sustainable mental health education and long-term resettlement services targeted at social integration that consider gender difference are urgently needed in host countries

Earliest stone-tipped projectiles from the Ethiopian Rift date to> 279,000 years ago

Projectile weapons (i.e. those delivered from a distance) enhanced prehistoric hunting efficiency by enabling higher impact delivery and hunting of a broader range of animals while reducing confrontations with dangerous prey species. Projectiles therefore provided a significant advantage over thrusting spears. Composite projectile technologies are considered indicative of complex behavior and pivotal to the successful spread of Homo sapiens . Direct evidence for such projectiles is thus far unknown from >80,000 years ago. Data from velocity-dependent microfracture features, diagnostic damage patterns, and artifact shape reported here indicate that pointed stone artifacts from Ethiopia were used as projectile weapons (in the form of hafted javelin tips) as early as >279,000 years ago. In combination with the existing archaeological, fossil and genetic evidence, these data isolate eastern Africa as a source of modern cultures and biology

A pulse of mid-Pleistocene rift volcanism in Ethiopia at the dawn of modern humans

The Ethiopian Rift Valley hosts the longest record of human co-existence with volcanoes on Earth, however, current understanding of the magnitude and timing of large explosive eruptions in this region is poor. Detailed records of volcanism are essential for interpreting the palaeoenvironments occupied by our hominin ancestors; and also for evaluating the volcanic hazards posed to the 10 million people currently living within this active rift zone. Here we use new geochronological evidence to suggest that a 200 km-long segment of rift experienced a major pulse of explosive volcanic activity between 320 and 170 ka. During this period, at least four distinct volcanic centres underwent large-volume (>10 km3) caldera-forming eruptions, and eruptive fluxes were elevated five times above the average eruption rate for the past 700 ka. We propose that such pulses of episodic silicic volcanism would have drastically remodelled landscapes and ecosystems occupied by early hominin populations

A computational model of liver iron metabolism

Iron is essential for all known life due to its redox properties; however, these same properties can also lead to its toxicity in overload through the production of reactive oxygen species. Robust systemic and cellular control are required to maintain safe levels of iron, and the liver seems to be where this regulation is mainly located. Iron misregulation is implicated in many diseases, and as our understanding of iron metabolism improves, the list of iron-related disorders grows. Recent developments have resulted in greater knowledge of the fate of iron in the body and have led to a detailed map of its metabolism; however, a quantitative understanding at the systems level of how its components interact to produce tight regulation remains elusive. A mechanistic computational model of human liver iron metabolism, which includes the core regulatory components, is presented here. It was constructed based on known mechanisms of regulation and on their kinetic properties, obtained from several publications. The model was then quantitatively validated by comparing its results with previously published physiological data, and it is able to reproduce multiple experimental findings. A time course simulation following an oral dose of iron was compared to a clinical time course study and the simulation was found to recreate the dynamics and time scale of the systems response to iron challenge. A disease state simulation of haemochromatosis was created by altering a single reaction parameter that mimics a human haemochromatosis gene (HFE) mutation. The simulation provides a quantitative understanding of the liver iron overload that arises in this disease. This model supports and supplements understanding of the role of the liver as an iron sensor and provides a framework for further modelling, including simulations to identify valuable drug targets and design of experiments to improve further our knowledge of this system