An unexpected disruption of the atmospheric quasi-biennial oscillation

This is the author accepted manuscript. The final version is available from AAAS via the DOI in this recordWe thank the European Centre for Medium-Range Weather Forecasts for providing ERA-Interim and Operational Analysis data (www.ecmwf.int/en/forecasts) and the Freie Universität Berlin for providing radiosonde data (www.geo.fu-berlin.de/en/met/ag/strat/produkte/qbo). The CMIP5 data was obtained from the British Atmospheric Data Centre (browse.ceda.ac.uk/browse/badc/cmip5). A summary of data used in the study is listed in table S1.One of the most repeatable phenomena seen in the atmosphere, the quasi-biennial oscillation (QBO) between prevailing eastward and westward wind jets in the equatorial stratosphere (approximately 16 to 50 kilometers altitude), was unexpectedly disrupted in February 2016. An unprecedented westward jet formed within the eastward phase in the lower stratosphere and cannot be accounted for by the standard QBO paradigm based on vertical momentum transport. Instead, the primary cause was waves transporting momentum from the Northern Hemisphere. Seasonal forecasts did not predict the disruption, but analogous QBO disruptions are seen very occasionally in some climate simulations. A return to more typical QBO behavior within the next year is forecast, although the possibility of more frequent occurrences of similar disruptions is projected for a warming climate.S.M.O. was supported by UK Natural Environment Research Council grants NE/M005828/1 and NE/P006779/1. A.A.S., J.R.K., and N.B. were supported by the Joint UK Business, Energy and Industrial Strategy/Defra Met Office Hadley Centre Climate Programme (GA01101). A.A.S. and J.R.K. were additionally supported by the EU Seventh Framework Programme SPECS (Seasonal-to-decadal climate Prediction for the improvement of European Climate Services) project

Possible impacts of a future grand solar minimum on climate: Stratospheric and global circulation changes.

This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/2014JD022022A future decline in solar activity would not offset projected global warmingA future decline in solar activity could have larger regional effects in winterTop-down mechanism contributes to Northern Hemisphere regional response.LJG and ACM were supported by the National Centre for Atmospheric Science's Climate Directorate. ACM also acknowledges support from the ERC ACCI project no. 267760 and an AXA Postdoctoral Fellowship. SI and AAS were supported by the Joint DECC/Defra Met Office Hadley Centre Climate Programme (GA01101). LJG and JAA were supported by a grant from the National Environmental Research Council

On the role of Rossby wave breaking in quasi‐biennial odulation of the stratospheric polar vortex

The boreal‐winter stratospheric polar vortex is more disturbed when the quasi‐biennial oscillation (QBO) in the lower stratosphere is in its easterly phase (eQBO), and more stable during the westerly phase (wQBO). This so‐called “Holton‐Tan effect” (HTE) is known to involve Rossby waves (RWs) but the details remain obscure. This tropical‐extratropical connection is re‐examined in an attempt to explain its intra‐seasonal variation and its relation to Rossby wave breaking (RWB). Reanalyses in isentropic coordinates from the National Center for Environmental Prediction Climate Forecast System for the 1979 – 2017 period are used to evaluate the relevant features of RWB in the context of waveguide, wave mean‐flow interaction, and the QBO‐induced meridional circulation. During eQBO, the net extratropical wave forcing is enhanced in early winter with ~25% increase in upward propagating PRWs of zonal wavenumber 1 (wave‐1). RWB is also enhanced in the lower stratosphere, characterized by convergent anomalies in the subtropics and at high‐latitudes and strengthened waveguide in between at 20‐40°N, 350‐650 K. In late winter, RWB leads to finite amplitude growth, which hinders upward propagating PRWs of zonal wavenumber 2 and 3 (wave‐2‐3). During wQBO, RWB in association with wave‐2‐3 is enhanced in the upper stratosphere. Wave absorption/mixing in the surf zone reinforces a stable polar vortex in early to middle winter. A poleward confinement of extratropical waveguide in the upper stratosphere forces RWB to extend downward around January. A strengthening of upward propagating wave‐2‐3 follows and the polar‐vortex response switches from reinforcement to disturbance around February, thus a sign reversal of the HTE in late winter

Estimates of probable dementia prevalence from population-based surveys compared with dementia prevalence estimates based on meta-analyses

<p>Abstract</p> <p>Background</p> <p>National data on dementia prevalence are not always available, yet it may be possible to obtain estimates from large surveys that include dementia screening instruments. In Australia, many of the dementia prevalence estimates are based on European data collected between 15 and 50 years ago. We derived population-based estimates of probable dementia and possible cognitive impairment in Australian studies using the Mini-Mental State Examination (MMSE), and compared these to estimates of dementia prevalence from meta-analyses of European studies.</p> <p>Methods</p> <p>Data sources included a pooled dataset of Australian longitudinal studies (DYNOPTA), and two Australian Bureau of Statistics National Surveys of Mental Health and Wellbeing. National rates of probable dementia (MMSE < 24) and possible cognitive impairment (24-26) were estimated using combined sample weights.</p> <p>Results</p> <p>Estimates of probable dementia were higher in surveys than in meta-analyses for ages 65-84, but were similar at ages 85 and older. Surveys used weights to account for sample bias, but no adjustments were made in meta-analyses. Results from DYNOPTA and meta-analyses had a very similar pattern of increase with age. Contrary to trends from some meta-analyses, rates of probable dementia were not higher among women in the Australian surveys. Lower education was associated with higher prevalence of probable dementia. Data from investigator-led longitudinal studies designed to assess cognitive decline appeared more reliable than government health surveys.</p> <p>Conclusions</p> <p>This study shows that estimates of probable dementia based on MMSE in studies where cognitive decline and dementia are a focus, are a useful adjunct to clinical studies of dementia prevalence. Such information and may be used to inform projections of dementia prevalence and the concomitant burden of disease.</p

Epidemiology of Coxiella burnetii infection in Africa: a OneHealth systematic review

Background: Q fever is a common cause of febrile illness and community-acquired pneumonia in resource-limited settings. Coxiella burnetii, the causative pathogen, is transmitted among varied host species, but the epidemiology of the organism in Africa is poorly understood. We conducted a systematic review of C. burnetii epidemiology in Africa from a “One Health” perspective to synthesize the published data and identify knowledge gaps.&lt;p&gt;&lt;/p&gt; Methods/Principal Findings: We searched nine databases to identify articles relevant to four key aspects of C. burnetii epidemiology in human and animal populations in Africa: infection prevalence; disease incidence; transmission risk factors; and infection control efforts. We identified 929 unique articles, 100 of which remained after full-text review. Of these, 41 articles describing 51 studies qualified for data extraction. Animal seroprevalence studies revealed infection by C. burnetii (&#8804;13%) among cattle except for studies in Western and Middle Africa (18–55%). Small ruminant seroprevalence ranged from 11–33%. Human seroprevalence was &#60;8% with the exception of studies among children and in Egypt (10–32%). Close contact with camels and rural residence were associated with increased seropositivity among humans. C. burnetii infection has been associated with livestock abortion. In human cohort studies, Q fever accounted for 2–9% of febrile illness hospitalizations and 1–3% of infective endocarditis cases. We found no studies of disease incidence estimates or disease control efforts.&lt;p&gt;&lt;/p&gt; Conclusions/Significance: C. burnetii infection is detected in humans and in a wide range of animal species across Africa, but seroprevalence varies widely by species and location. Risk factors underlying this variability are poorly understood as is the role of C. burnetii in livestock abortion. Q fever consistently accounts for a notable proportion of undifferentiated human febrile illness and infective endocarditis in cohort studies, but incidence estimates are lacking. C. burnetii presents a real yet underappreciated threat to human and animal health throughout Africa.&lt;p&gt;&lt;/p&gt

Intergenerational Practice in the Community—What Does the Community Think?

The many changes that occur in the lives of older people put them at an increased risk of being socially isolated and lonely. Intergenerational programs for older adults and young children can potentially address this shortfall, because of the perceived benefit from generations interacting. This study explores whether there is an appetite in the community for intergenerational programs for community dwelling older adults. An online survey was distributed via social media, research team networks, and snowballing recruitment with access provided via QR code or hyperlink. Semi-structured interviews were undertaken with potential participants of a pilot intergenerational program planned for the Eastern Suburbs of Sydney, Australia in 2020. The interviews were thematically analyzed. Over 250 people completed the survey, and 21 interviews took place with older adults (10) and parents of young children (11). The data showed that participants were all in favor of intergenerational programs, but there were different perceptions about who benefits most and how. The study highlighted considerations to be addressed in the development of effective and sustainable intergenerational programs. For example, accessing people in the community who are most socially isolated and lonely was identified as a primary challenge. More evidence-based research is needed to support involvement of different cohorts, such as those who are frail, or living with physical or cognitive limitations.</jats:p

The association of APOE genotype and cognitive decline in interaction with risk factors in a 65–69 year old community sample

<p>Abstract</p> <p>Background</p> <p>While the evidence of an association between the apolipoprotein E (<it>APOE</it>) <it>*E4 </it>allele and Alzheimer's disease is very strong, the effect of the <it>*E4 </it>allele on cognitive decline in the general population is more equivocal. A cross-sectional study on the lifespan effects of the <it>*E4 </it>allele <abbrgrp><abbr bid="B1">1</abbr></abbrgrp> failed to find any effect of the <it>*E4 </it>allele on cognitive performance at ages 20–24, 40–44 or 60–64 years.</p> <p>Methods</p> <p>In this four year follow-up study, we reexamine the effect of <it>*E4 </it>in the sample of 2,021 individuals, now aged 65–69 years.</p> <p>Results</p> <p>Performance on the Mini-Mental State Examination (MMSE) was significantly poorer for <it>*E4 </it>homozygotes than heterozygotes or non-carriers. The effects of the <it>*E4 </it>genotype on cognitive decline over four years were found on the MMSE and Symbol-Digit Modalities test but only when controlling for risk factors such as head injury and education. Analyses were repeated with the exclusion of participants diagnosed with a mild cognitive disorder, with little change.</p> <p>Conclusion</p> <p>It is possible that <it>*E4 </it>carriers become vulnerable to greater cognitive decline in the presence of other risk factors at 65–69 years of age.</p

Incidence of self-reported brain injury and the relationship with substance abuse: findings from a longitudinal community survey

<p>Abstract</p> <p>Background</p> <p>Traumatic or serious brain injury (BI) has persistent and well documented adverse outcomes, yet 'mild' or 'moderate' BI, which often does not result in hospital treatment, accounts for half the total days of disability attributed to BI. There are currently few data available from community samples on the incidence and correlates of these injuries. Therefore, the study aimed to assess the 1) incidence of self-reported mild (not requiring hospital admission) and moderate (admitted to hospital)) brain injury (BI), 2) causes of injury 3) physical health scores and 4) relationship between BI and problematic alcohol or marijuana use.</p> <p>Methods</p> <p>An Australian community sequential-cohort study (cohorts aged 20-24, 40-44 and 60-64 years at wave one) used a survey methodology to assess BI and substance use at baseline and four years later.</p> <p>Results</p> <p>Of the 7485 wave one participants, 89.7% were re-interviewed at wave two. There were 56 mild (230.8/100000 person-years) and 44 moderate BI (180.5/100000 person-years) reported between waves one and two. Males and those in the 20-24 year cohort had increased risk of BI. Sports injury was the most frequent cause of BI (40/100) with traffic accidents being a greater proportion of moderate (27%) than mild (7%) BI. Neither alcohol nor marijuana problems at wave one were predictors of BI. BI was not a predictor of developing substance use problems by wave two.</p> <p>Conclusions</p> <p>BI were prevalent in this community sample, though the incidence declined with age. Factors associated with BI in community samples differ from those reported in clinical samples (e.g. typically traumatic brain injury with traffic accidents the predominate cause). Further, detailed evaluation of the health consequences of these injuries is warranted.</p

Assessment of severe malaria in a multicenter, phase III, RTS, S/AS01 malaria candidate vaccine trial: case definition, standardization of data collection and patient care

BACKGROUND\ud \ud An effective malaria vaccine, deployed in conjunction with other malaria interventions, is likely to substantially reduce the malaria burden. Efficacy against severe malaria will be a key driver for decisions on implementation. An initial study of an RTS, S vaccine candidate showed promising efficacy against severe malaria in children in Mozambique. Further evidence of its protective efficacy will be gained in a pivotal, multi-centre, phase III study. This paper describes the case definitions of severe malaria used in this study and the programme for standardized assessment of severe malaria according to the case definition.\ud \ud METHODS\ud \ud Case definitions of severe malaria were developed from a literature review and a consensus meeting of expert consultants and the RTS, S Clinical Trial Partnership Committee, in collaboration with the World Health Organization and the Malaria Clinical Trials Alliance. The same groups, with input from an Independent Data Monitoring Committee, developed and implemented a programme for standardized data collection.The case definitions developed reflect the typical presentations of severe malaria in African hospitals. Markers of disease severity were chosen on the basis of their association with poor outcome, occurrence in a significant proportion of cases and on an ability to standardize their measurement across research centres. For the primary case definition, one or more clinical and/or laboratory markers of disease severity have to be present, four major co-morbidities (pneumonia, meningitis, bacteraemia or gastroenteritis with severe dehydration) are excluded, and a Plasmodium falciparum parasite density threshold is introduced, in order to maximize the specificity of the case definition. Secondary case definitions allow inclusion of co-morbidities and/or allow for the presence of parasitaemia at any density. The programmatic implementation of standardized case assessment included a clinical algorithm for evaluating seriously sick children, improvements to care delivery and a robust training and evaluation programme for clinicians.\ud \ud CONCLUSIONS\ud \ud The case definition developed for the pivotal phase III RTS, S vaccine study is consistent with WHO recommendations, is locally applicable and appropriately balances sensitivity and specificity in the diagnosis of severe malaria. Processes set up to standardize severe malaria data collection will allow robust assessment of the efficacy of the RTS, S vaccine against severe malaria, strengthen local capacity and benefit patient care for subjects in the trial.\ud \ud TRIAL REGISTRATION\ud \ud Clinicaltrials.gov NCT00866619

A simple measure with complex determinants: investigation of the correlates of self-rated health in older men and women from three continents

Self-rated health is commonly employed in research studies that seek to assess the health status of older individuals. Perceptions of health are, however, influenced by individual and societal level factors that may differ within and between countries. This study investigates levels of self-rated health (SRH) and correlates of SRH among older adults in Australia, United States of America (USA), Japan and South Korea. We conclude that when examining correlates of SRH, the similarities are greater than the differences between countries. There are however differences in levels of SRH which are not fully accounted for by the health correlates. Broad generalizations about styles of responding are not helpful for understanding these differences, which appear to be country- and possibly cohort-specific. When using SRH to characterize the health status of older people, it is important to consider earlier life experiences of cohorts as well as national and individual factors in later life. Further research is required to understand the complex societal influences on perceptions of health.The Australian data on which this research is based were drawn from several Australian longitudinal studies including: the Australian Longitudinal Study of Ageing (ALSA), the Australian Longitudinal Study of Women’s Health (ALSWH) and the Personality And Total Health Through Life Study (PATH). These studies were pooled and harmonized for the Dynamic Analyses to Optimize Ageing (DYNOPTA) project. DYNOPTA was funded by a National Health and Medical Research Council (NHMRC) grant (# 410215)