Development of convection along the SPCZ within a Madden-Julian oscillation

A subtropical Rossby wave propagation mechanism is proposed to account for the poleward and eastward progression of intraseasonal convective anomalies along the South Pacific Convergence Zone (SPCZ) that is observed in a significant proportion of Madden-Julian Oscillations (MJOs). Large scale convection, associated with an MJO, is assumed to be already established over the Indonesian region. The latent heating associated with this convection forces an equatorial Rossby wave response with an upper tropospheric anticyclone, centred over or slightly to the west of the convection. Large potential vorticity (PV) gradients, associated with the subtropical jet and the tropopause, lie just poleward of the anticyclone and large magnitude PV air is advected equatorwards on the eastern side of the anticyclone. This ``high'' PV air, or upper tropospheric trough, is far enough off the equator that it has associated strong horizontal temperature gradients, and it induces deep ascent on its eastern side, at a latitude of about 15-30\degr. If this deep ascent is over a region susceptible to deep convection, such as the SPCZ region, then convection may be forced or triggered. Hence convection develops along the SPCZ as a forced response to convection over Indonesia. The response mechanism is essentially one of subtropical Rossby wave propagation. This hypothesis is based on a case study of a particularly strong MJO in early 1988, and is tested by idealised modelling studies. The mechanism may also be relevant to the existence of the mean SPCZ, as a forced response to mean Indonesian convection

Fast and slow Kelvin waves in the Madden-Julian Oscillation of a GCM

The structure of the Madden-Julian Oscillation (MJO) in an 1800-day integration of the Hadley Centre Unified Model was analysed, and interpreted within a Kelvin wave framework. The model was forced with constant equinoctial (March) boundary conditions so that a ``clean'' MJO signal could be separated from the effects of the seasonal cycle and forced interannual variability. The simulated MJO was fairly realistic in terms of its large-scale spatial structure and propagation characteristics, although its period of 30 days (corresponding to an average phase speed of 15 \mps) was shorter than that observed. The signal in deep convection was less coherent than in observations, and appeared to move eastward as a sequence of discrete convective anomalies, rather than by a smooth eastward propagation. Both ``fast'' and ``slow'' equatorial Kelvin waves appeared to play an important role in the eastward propagation of the simulated MJO. Enhanced convection over the Indian Ocean was associated with a ``fast'' equatorial Kelvin wave that propagated eastward at 55 m s-1 over the Pacific. On reaching the west coast of South America, a component of this Kelvin wave propagated northward and southward as a trapped wave along the mountain ranges of Central America and the Andes, in agreement with observations. The anomalous surface easterlies over the tropical eastern Pacific associated with this fast Kelvin wave enhanced the climatological mean easterlies and led to positive convective anomalies over the eastern Pacific consistent with the WISHE mechanism. However, WISHE was not able to account for the eastward development of the convective anomalies over the Indian Ocean/western Pacific region. By splitting the equatorial divergence anomalies of the simulated MJO into their du/dx and dv/dy components, the role of Kelvin wave dynamics in the ``slow'' (15 m s-1) average eastward propagation of the simulated MJO was examined. Although the two components were of comparable magnitude, the \dudx\ component exhibited a pronounced eastward propagation which tended to be disrupted by the \dvdy\ component, thus supporting the paradigm of an underlying, but strongly modified, Kelvin wave mechanism

Taking an Extra Moment to Consider Treatment Effects on Distributions

This paper introduces Parameter Estimation by Raw Moments (PERM), a flexible method for evaluating a policy’s impact on the parameters of an outcome distribution. Such parameters include the variance (E[Y2]−E[Y]2), skewness and covariance of two outcomes. PERM simplifies distributional analysis by first separately estimating higher-order moment treatment effects (e.g., E[Y2]), then combining these to derive distribution parameter treatment effects. Two implementations are discussed: regression with controls and DiD with staggered roll-out. Applying PERM DiD to a Swedish school reform finds it reduced education inequality but increased earnings variance resulting in a lower covariance between education and earnings

Children's time allocation and the socioeconomic gap in human capital

Children's time investments in various activities may be important for reducing socioeconomic status (SES) gaps in educational and mental health outcomes. Using detailed time use diaries of Australian children aged 4–14, we observe that children from low SES backgrounds spend more time on digital media and less time on out-of-school enrichment activities, organised or for leisure. We explain the SES gap by employing a human capital development panel model and find that this difference contributes about 3% to the observed SES gap in numeracy skills. The results are supported by exogeneity tests and numerous robustness checks. The contribution is larger for males, older age groups, and if the cumulative effect on learning is considered. No clear results are found for literacy skills and mental health outcomes. The findings imply that interventions promoting a shift away from digital media towards out-of-school enrichment activities could help reduce the SES gap in human capital.</p

Time characteristics of the effect of alcohol cessation on the risk of stomach cancer a meta-analysis

Background: In the Bagnardi et al. (2001) meta-analysis, it was found that alcohol consumption increases the risk of stomach cancer (OR = 1.32 for heavy drinkers). However, it is unknown if drinking cessation reverses this alcohol-elevated risk. Methods: A systematic literature review was performed to provide the information for a meta-analysis where the dose-risk trend was estimated for years since drinking cessation and the risk of stomach cancer. A random effect generalised least squares model for trend estimation was used, employing study characteristics to control for heterogeneity. Results: Nineteen observational studies were identified in the literature review, of which five studies quantified duration of cessation and risk of stomach cancer, giving a total of 1947 cancer cases. No significant effect of drinking cessation on the risk of stomach cancer could be found (OR = 0.99 CI: 0.97-1.02). Conclusions: This result should be interpreted with caution due to the limited number of studies in this area. Recent findings suggest a link between heavy drinking and stomach cancer, especially gastric noncardia, but not for moderate drinking. Since all but one of the included studies in this meta-analysis failed to control for consumption level, the current study could not test if the risk decline following drinking cessation differs between moderate and high consumers

Frequency and intensity of alcohol consumption : New Evidence from Sweden

There is an increasing body of evidence that the intensity in which alcohol is drunk is of greater concern than the frequency or overall quantity consumed. This paper provides an extensive analysis of the demand for alcohol as measured by total quantity, frequency, and intensity. A unique large sample of cross-sectional data from Sweden 2004–2011 allows reduced-form alcohol demand equations to be estimated for beer, wine, and spirits, split by alcohol drinking pattern (average vs. binge drinkers) and gender. Results find a negative beer excise rate effect for participation and frequency, and positive effect for intensity. The effect was stronger for binge drinkers. Generally, the results also show a positive socioeconomic (income and education) gradient in frequency demand and a negative gradient in the intensity demand. Female wine drinkers show a positive socioeconomic gradient in both frequency and intensity. The findings highlight the complexity of this policy space. Tax increases appear to reduce frequency but raise intensity consumed. The more educated and higher earners drink more in total, but less intensely when they do and this is likely to explain in part why poor health is concentrated amongst lower socioeconomic status individuals

Os entraves à governabilidade no presidencialismo de coalizão : uma revisão bibliográfica

Orientador : Prof. Dr. Bruno BolognesiMonografia (especialização) - Universidade Federal do Paraná, Setor de Ciências Humanas, Curso de Especialização em Sociologia PolíticaInclui referênciasResumo : O presente trabalho aborda, uma síntese da obra clássica de Sérgio Abranches sobre o presidencialismo de coalizão e seus problemas quanto ao desencadeamento e manejo de crises políticas. Além disso, expõe os desdobramentos sobre a incapacidade que o Poder Executivo encontra para solucionar conflitos com o Poder Legislativo sem os devidos instrumentos institucionais de mediação. A partir deste clássico da literatura política nacional, os principais pontos levantados pelo autor são contrapostos, em uma revisão bibliográfica, por autores que contestam a incapacidade do Executivo em garantir a governabilidade frente a essa singularidade instituional. Transformações ocorridas desde a publicação de Abranches, por sinal, pouco antes da promulgação da Carta de 1988 e, posteriormente, na própria Constituição não passam incolume pelo olhar e análise de pesquisadores como Argelina Cheibub Figueiredo, Fernando Limongi e Fabiano Santos na desmistificação, através de evidências empíricas, de que o sistema institucional brasileiro é o grande responsável pela crise de govenabilidade que assola, em menor ou maior intensidade, esta jovem democracia pouco tempo após o término de um regime autoritário

[(Pyrrolidin-1-yl)carbothio­ylsulfan­yl]methyl pyrrolidine-1-carbodithio­ate

The title compound, C11H18N2S4, was unexpectedly obtained during studies on the reactivity of the complex tris­(acac-κ2 O,O′)gallium(III) (acac is acetyl­acetonate) with C4H8NCS2H in dichloro­methane. The title compound shows disordered two pyrrolidine rings with major and minor occupancies of 0.546 (4) and 0.454 (4). Two (pyrrolidin-1-yl)carbothio­ylsulfanyl units are linked together through a methyl­ene C atom and weak C—H⋯S inter­actions are found

How the risk of liver cancer changes after alcohol cessation: A review and meta-analysis of the current literature

<p>Abstract</p> <p>Background</p> <p>It is well established that drinking alcohol raises the risk of liver cancer (hepatocellular carcinoma). However, it has not been sufficiently established as to whether or not drinking cessation subsequently reduces the risk of liver cancer and if it does reduce the risk how long it takes for this heightened risk to fall to that of never drinkers. This question is important for effective policy design and evaluation, to establish causality and for motivational treatments.</p> <p>Methods</p> <p>A systematic review and meta-analysis using the current available evidence and a specific form of Generalised Least Squares is performed to assess how the risk of liver cancer changes with time for former drinkers.</p> <p>Results</p> <p>Four studies are found to have quantified the effect of drinking cessation on the risk of liver cancer. The meta-analysis suggests that the risk of liver cancer does indeed fall after cessation by 6-7% a year, but there remains a large uncertainty around this estimate both statistically and in its interpretation. As an illustration it is estimated that a time period of 23 years is required after drinking cessation, with a correspondingly large 95% confidence interval of 14 to 70 years, for the risk of liver cancer to be equal to that of never drinkers.</p> <p>Conclusion</p> <p>This is a relatively under researched area and this is reflected in the uncertainty of the findings. It is our view that it is not possible to extrapolate the results found here to the general population. Too few studies have addressed this question and of the studies that have, all have significant limitations. The key issue amongst the relevant studies is that it appears that current drinkers, abstainers and former drinkers are not composed of, or effectively adjusted to be, similar populations making inferences about risk changes impossible. This is a very difficult area to study effectively, but it is an important topic. More work is required to reduce both statistical uncertainty and tackle the various study limitations this paper highlights and until this is done, the current result should be considered preliminary.</p