Early warning signals of Atlantic Meridional Overturning Circulation collapse in a fully coupled climate model.

Journal ArticleResearch Support, Non-U.S. Gov'tCopyright © 2014 Macmillan Publishers Limited. All Rights Reserved.The Atlantic Meridional Overturning Circulation (AMOC) exhibits two stable states in models of varying complexity. Shifts between alternative AMOC states are thought to have played a role in past abrupt climate changes, but the proximity of the climate system to a threshold for future AMOC collapse is unknown. Generic early warning signals of critical slowing down before AMOC collapse have been found in climate models of low and intermediate complexity. Here we show that early warning signals of AMOC collapse are present in a fully coupled atmosphere-ocean general circulation model, subject to a freshwater hosing experiment. The statistical significance of signals of increasing lag-1 autocorrelation and variance vary with latitude. They give up to 250 years warning before AMOC collapse, after ~550 years of monitoring. Future work is needed to clarify suggested dynamical mechanisms driving critical slowing down as the AMOC collapse is approached.NERCUniversity of ExeterEuropean Union Seventh Framework programme FP7/2007-201

Impacts of behavioural factors on the household water consumption in urban areas

Gaps in understanding what influences household water consumption has led water providers failing to convince their customers to report sustainable practices. To this end, the present study aimed to answer the question, “How do social and cultural factors influence water consumption in urban areas”? The response to this issue has been identified through an investigation that involved a group of selected socio-cultural factors, whose analysis was based on collected survey data from participants in Lagos-Nigeria, Salvador-Brazil, Sao Paulo-Brazil, London-UK and Los Angeles-USA. The Capability-Opportunity-Motivation-Behaviour (COM-B) model was used as a data analysis framework to identify influences. The investigation revealed that Motivation is the most reported driver of water consumption. In a scale from 0 (lowest) to 5 (highest), this component presented the most significant scores in Lagos (3.93), Salvador (4.13), Sao Paulo (3.88), London (4.13) and Los Angeles (3.59). The Capability dimension had the second-highest weight in Lagos, Salvador, Sao Paulo, and Los Angeles, with scores of 2.80, 3.60, 3.60 and 3.20, respectively. Participants from London have Opportunity (score= 2.88) as the second influential pillar in water consumption. These findings are aimed at helping to best drive water saving practices by gaining insight into factors underpinning water consumption in a structured manner

Global distribution of the sickle cell gene and geographical confirmation of the malaria hypothesis

It has been 100 years since the first report of sickle haemoglobin (HbS). More than 50 years ago, it was suggested that the gene responsible for this disorder could reach high frequencies because of resistance conferred against malaria by the heterozygous carrier state. This traditional example of balancing selection is known as the 'malaria hypothesis'. However, the geographical relationship between the transmission intensity of malaria and associated HbS burden has never been formally investigated on a global scale. Here, we use a comprehensive data assembly of HbS allele frequencies to generate the first evidence-based map of the worldwide distribution of the gene in a Bayesian geostatistical framework. We compare this map with the pre-intervention distribution of malaria endemicity, using a novel geostatistical area-mean comparison. We find geographical support for the malaria hypothesis globally; the relationship is relatively strong in Africa but cannot be resolved in the Americas or in Asia

Are autistic traits in the general population stable across development?

There is accumulating evidence that autistic traits (AT) are on a continuum in the general population, with clinical autism representing the extreme end of a quantitative distribution. While the nature and severity of symptoms in clinical autism are known to persist over time, no study has examined the long-term stability of AT among typically developing toddlers. The current investigation measured AT in 360 males and 400 males from the general population close to two decades apart, using the Pervasive Developmental Disorder subscale of the Child Behavior Checklist in early childhood (M = 2.14 years; SD = 0.15), and the Autism-Spectrum Quotient in early adulthood (M = 19.50 years; SD = 0.70). Items from each scale were further divided into social (difficulties with social interaction and communication) and non-social (restricted and repetitive behaviours and interests) AT. The association between child and adult measurements of AT as well the influence of potentially confounding sociodemographic, antenatal and obstetric variables were assessed using Pearson's correlations and linear regression. For males, Total AT in early childhood were positively correlated with total AT (r = .16, p = .002) and social AT (r = .16, p = .002) in adulthood. There was also a positive correlation for males between social AT measured in early childhood and Total (r = .17, p = .001) and social AT (r = .16, p = .002) measured in adulthood. Correlations for non-social AT did not achieve significance in males. Furthermore, there was no significant longitudinal association in AT observed for males or females. Despite the constraints of using different measures and different raters at the two ages, this study found modest developmental stability of social AT from early childhood to adulthood in boys

Parametric study of EEG sensitivity to phase noise during face processing

<b>Background: </b> The present paper examines the visual processing speed of complex objects, here faces, by mapping the relationship between object physical properties and single-trial brain responses. Measuring visual processing speed is challenging because uncontrolled physical differences that co-vary with object categories might affect brain measurements, thus biasing our speed estimates. Recently, we demonstrated that early event-related potential (ERP) differences between faces and objects are preserved even when images differ only in phase information, and amplitude spectra are equated across image categories. Here, we use a parametric design to study how early ERP to faces are shaped by phase information. Subjects performed a two-alternative force choice discrimination between two faces (Experiment 1) or textures (two control experiments). All stimuli had the same amplitude spectrum and were presented at 11 phase noise levels, varying from 0% to 100% in 10% increments, using a linear phase interpolation technique. Single-trial ERP data from each subject were analysed using a multiple linear regression model. <b>Results: </b> Our results show that sensitivity to phase noise in faces emerges progressively in a short time window between the P1 and the N170 ERP visual components. The sensitivity to phase noise starts at about 120–130 ms after stimulus onset and continues for another 25–40 ms. This result was robust both within and across subjects. A control experiment using pink noise textures, which had the same second-order statistics as the faces used in Experiment 1, demonstrated that the sensitivity to phase noise observed for faces cannot be explained by the presence of global image structure alone. A second control experiment used wavelet textures that were matched to the face stimuli in terms of second- and higher-order image statistics. Results from this experiment suggest that higher-order statistics of faces are necessary but not sufficient to obtain the sensitivity to phase noise function observed in response to faces. <b>Conclusion: </b> Our results constitute the first quantitative assessment of the time course of phase information processing by the human visual brain. We interpret our results in a framework that focuses on image statistics and single-trial analyses

Understanding Russia's return to the Middle East

Over recent years, there has been a significant resurgence of Russian power and influence in the Middle East, which has been evident in the diplomatic and military intervention into Syria. This article identifies the principal factors behind Russia’s return to the region. First, there are domestic political influences with the coincidence of the uprisings in the Middle East, the so-called ‘Arab Spring,’ with large-scale domestic opposition protests within Russia during the elections in 2011–2012. Second, there is the role of ideas, most notably the growing anti-Westernism in Putin’s third presidential term, along with Russia’s own struggle against Islamist terrorism. These ideational factors contributed to Russia’s resolve to support the Assad government against both Western intervention and its domestic Islamist opposition. Third, Russia has benefited from a pragmatic and flexible approach in its engagement with the region. Moscow seeks to ensure that it is a critical actor for all the various states and political movements in the Middle East

Assessing Communities of Practice in health policy : A conceptual framework as a first step towards empirical research

Peer reviewe

Identification of bacterial glycosidases in rat cecal contents

Cecal contents of conventional and germfree rats were examined for glycosidases which may have a role in degrading glycoprotein oligosaccharides. Utilizing p-nitrophenylglycosides as substrates, we identified glycosidases in bacteria-free supernatants from cecal contents which act on β-linkages. These cecal glycosidases appear to be of bacterial origin since: (1) direct comparisons of the enzymes in similar contents from germfree rats showed negligible activities; (2) most of the glycosidase levels in bacterial extracts were at least as high as those of soluble supernatants; and (3) disk gel electrophoresis of contents and bacterial extracts revealed in both preparations a β- N -acetylglucosaminidase band with similar R f s. Also, the blood group B antigenicity of germfree cecal glycoproteins was greatly decreased by conventional cecal contents. These findings indicate that β-galactosidase and β- N -acetylgalactosaminidase in cecal contents are bacterial in origin, and they may have a role in the bacterial catabolism of intestinal glycoproteins.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44391/1/10620_2005_Article_BF01309607.pd

Preventing the Reintroduction of Malaria in Mauritius: A Programmatic and Financial Assessment

Sustaining elimination of malaria in areas with high receptivity and vulnerability will require effective strategies to prevent reestablishment of local transmission, yet there is a dearth of evidence about this phase. Mauritius offers a uniquely informative history, with elimination of local transmission in 1969, re-emergence in 1975, and second elimination in 1998. Towards this end, Mauritius's elimination and prevention of reintroduction (POR) programs were analyzed via a comprehensive review of literature and government documents, supplemented by program observation and interviews with policy makers and program personnel. The impact of the country's most costly intervention, a passenger screening program, was assessed quantitatively using simulation modeling