The detection of atmospheric rivers in atmospheric reanalyses and their links to British winter floods and the large-scale climatic circulation

Atmospheric Rivers (ARs), narrow plumes of enhanced moisture transport in the lower troposphere, are a key synoptic feature behind winter flooding in midlatitude regions. This article develops an algorithm which uses the spatial and temporal extent of the vertically integrated horizontal water vapor transport for the detection of persistent ARs (lasting 18 h or longer) in five atmospheric reanalysis products. Applying the algorithm to the different reanalyses in the vicinity of Great Britain during the winter half-years of 1980–2010 (31 years) demonstrates generally good agreement of AR occurrence between the products. The relationship between persistent AR occurrences and winter floods is demonstrated using winter peaks-over-threshold (POT) floods (with on average one flood peak per winter). In the nine study basins, the number of winter POT-1 floods associated with persistent ARs ranged from approximately 40 to 80%. A Poisson regression model was used to describe the relationship between the number of ARs in the winter half-years and the large-scale climate variability. A significant negative dependence was found between AR totals and the Scandinavian Pattern (SCP), with a greater frequency of ARs associated with lower SCP values.

Rigid body trajectories in different 6D spaces

The objective of this paper is to show that the group SE(3) with an imposed Lie-Poisson structure can be used to determine the trajectory in a spatial frame of a rigid body in Euclidean space. Identical results for the trajectory are obtained in spherical and hyperbolic space by scaling the linear displacements appropriately since the influence of the moments of inertia on the trajectories tends to zero as the scaling factor increases. The semidirect product of the linear and rotational motions gives the trajectory from a body frame perspective. It is shown that this cannot be used to determine the trajectory in the spatial frame. The body frame trajectory is thus independent of the velocity coupling. In addition, it is shown that the analysis can be greatly simplified by aligning the axes of the spatial frame with the axis of symmetry which is unchanging for a natural system with no forces and rotation about an axis of symmetry.

On wave action and phase in the non-canonical Hamiltonian formulation

The long time–evolution of disturbances to slowly–varying solutions of partial differential equations is subject to the adiabatic invariance of the wave action. Generally, this approximate conservation law is obtained under the assumption that the partial differential equations are derived from a variational principle or have a canonical Hamiltonian structure. Here, the wave action conservation is examined for equations that possess a non–canonical (Poisson) Hamiltonian structure. The linear evolution of disturbances in the form of slowly varying wavetrains is studied using a WKB expansion. The properties of the original Hamiltonian system strongly constrain the linear equations that are derived, and this is shown to lead to the adiabatic invariance of a wave action. The connection between this (approximate) invariance and the (exact) conservation laws of pseudo–energy and pseudomomentum that exist when the basic solution is exactly time and space independent is discussed. An evolution equation for the slowly varying phase of the wavetrain is also derived and related to Berry's phase.

Characterization and antimicrobial efficacy against E. coli of a helium/air plasma at atmospheric pressure created in a plastic package

A plasma source, sustained by the application of a floating high voltage (±15 kV) to parallel-plate electrodes at 50 Hz, has been achieved in a helium/air mixture at atmospheric pressure (P = 105 Pa) contained in a zip-locked plastic package placed in the electrode gap. Some of the physical and antimicrobial properties of this apparatus were established with a view to ascertain its performance as a prototype for the disinfection of fresh produce. The current–voltage (I–V) and charge–voltage (Q–V) characteristics of the system were measured as a function of gap distance d, in the range (3 × 103 ≤ Pd ≤ 1.0 × 104 Pa m). The electrical measurements showed this plasma source to exhibit the characteristic behaviour of a dielectric barrier discharge in the filamentary mode and its properties could be accurately interpreted by the two-capacitance in series model. The power consumed by the discharge and the reduced field strength were found to decrease quadratically from 12.0 W to 4.5 W and linearly from 140 Td to 50 Td, respectively, in the range studied. Emission spectra of the discharge were recorded on a relative intensity scale and the dominant spectral features could be assigned to strong vibrational bands in the 2+ and 1− systems of N2 and ${\rm N}_2^+$ , respectively, with other weak signatures from the NO and OH radicals and the N+, He and O atomic species. Absolute spectral intensities were also recorded and interpreted by comparison with the non-equilibrium synthetic spectra generated by the computer code SPECAIR. At an inter-electrode gap of 0.04 m, this comparison yielded typical values for the electron, vibrational and translational (gas) temperatures of (4980 ± 100) K, (2700 ± 200) K and (300 ± 100) K, respectively and an electron density of 1.0 × 1017 m−3. A Boltzmann plot also provided a value of (3200 ± 200 K) for the vibrational temperature. The antimicrobial efficacy was assessed by studying the resistance of both Escherichia coli K12 its isogenic mutants in soxR, soxS, oxyR, rpoS and dnaK selected to identify possible cellular responses and targets related with 5 min exposure to the active gas in proximity of, but not directly in, the path of the discharge filaments. Both the parent strain and mutants populations were significantly reduced by more than 1.5 log cycles in these conditions, showing the potential of the system. Post-treatment storage studies showed that some transcription regulators and specific genes related to oxidative stress play an important role in the E. coli repair mechanism and that plasma exposure affects specific cell regulator systems.

Extending the Lincoln–Petersen estimator for multiple identifications in one source

The Lincoln–Petersen estimator is one of the most popular estimators used in capture–recapture studies. It was developed for a sampling situation in which two sources independently identify members of a target population. For each of the two sources, it is determined if a unit of the target population is identified or not. This leads to a 2 × 2 table with frequencies f11, f10, f01, f00 indicating the number of units identified by both sources, by the first but not the second source, by the second but not the first source and not identified by any of the two sources, respectively. However, f00 is unobserved so that the 2 × 2 table is incomplete and the Lincoln–Petersen estimator provides an estimate for f00. In this paper, we consider a generalization of this situation for which one source provides not only a binary identification outcome but also a count outcome of how many times a unit has been identified. Using a truncated Poisson count model, truncating multiple identifications larger than two, we propose a maximum likelihood estimator of the Poisson parameter and, ultimately, of the population size. This estimator shows benefits, in comparison with Lincoln–Petersen’s, in terms of bias and efficiency. It is possible to test the homogeneity assumption that is not testable in the Lincoln–Petersen framework. The approach is applied to surveillance data on syphilis from Izmir, Turkey.

On the clustering of winter storm loss events over Germany

During the last decades, several windstorm series hit Europe leading to large aggregated losses. Such storm series are examples of serial clustering of extreme cyclones, presenting a considerable risk for the insurance industry. Clustering of events and return periods of storm series for Germany are quantified based on potential losses using empirical models. Two reanalysis data sets and observations from German weather stations are considered for 30 winters. Histograms of events exceeding selected return levels (1-, 2- and 5-year) are derived. Return periods of historical storm series are estimated based on the Poisson and the negative binomial distributions. Over 4000 years of general circulation model (GCM) simulations forced with current climate conditions are analysed to provide a better assessment of historical return periods. Estimations differ between distributions, for example 40 to 65 years for the 1990 series. For such less frequent series, estimates obtained with the Poisson distribution clearly deviate from empirical data. The negative binomial distribution provides better estimates, even though a sensitivity to return level and data set is identified. The consideration of GCM data permits a strong reduction of uncertainties. The present results support the importance of considering explicitly clustering of losses for an adequate risk assessment for economical applications.

Detecting regular sound changes in linguistics as events of concerted evolution

Background: Concerted evolution is normally used to describe parallel changes at different sites in a genome, but it is also observed in languages where a specific phoneme changes to the same other phoneme in many words in the lexicon—a phenomenon known as regular sound change. We develop a general statistical model that can detect concerted changes in aligned sequence data and apply it to study regular sound changes in the Turkic language family. Results: Linguistic evolution, unlike the genetic substitutional process, is dominated by events of concerted evolutionary change. Our model identified more than 70 historical events of regular sound change that occurred throughout the evolution of the Turkic language family, while simultaneously inferring a dated phylogenetic tree. Including regular sound changes yielded an approximately 4-fold improvement in the characterization of linguistic change over a simpler model of sporadic change, improved phylogenetic inference, and returned more reliable and plausible dates for events on the phylogenies. The historical timings of the concerted changes closely follow a Poisson process model, and the sound transition networks derived from our model mirror linguistic expectations. Conclusions: We demonstrate that a model with no prior knowledge of complex concerted or regular changes can nevertheless infer the historical timings and genealogical placements of events of concerted change from the signals left in contemporary data. Our model can be applied wherever discrete elements—such as genes, words, cultural trends, technologies, or morphological traits—can change in parallel within an organism or other evolving group.

Hydrodynamics with spin angular momentum from systematic coarse graining: a tutorial example

The derivation of time evolution equations for slow collective variables starting from a micro- scopic model system is demonstrated for the tutorial example of the classical, two-dimensional XY model. Projection operator techniques are used within a nonequilibrium thermodynamics framework together with molecular simulations in order to establish the building blocks of the hydrodynamics equations: Poisson brackets that determine the deterministic drift, the driving forces from the macroscopic free energy and the friction matrix. The approach is rather general and can be applied for deriving the equations of slow variables for a broad variety of systems.

Problems with accessibility to health services by persons with disabilities in Sao Paulo, Brazil

Purpose. To describe the occurrence of self-reported problems of accessibility to health services used by persons with disabilities in terms of social and health services variables. Methods. We performed a cross-sectional household survey designed to assess problems with accessibility to health services faced by persons with disabilities. We interviewed 333 persons in Sao Paulo city, in 2007. Variables related to the presence of accessibility problems, disabilities, gender, age, family head income, ethnicity, use of health services and others were analysed using frequencies, percentages, chi(2)-test, ANOVA and Poisson regression models. Results. 15.92% of the interviewed persons reported problems with accessibility to health services. Persons having multiple (prevalence ratios; PR = 2.91) or mobility disability (PR = 6.46) had more problems with accessibility than persons with hearing disability. Persons younger than 78 years old had more problems with accessibility; those who needed help to go to the health service (PR = 3.01) also. Conclusions. Persons with multiple or mobility disability, younger than 78 years, and those who needed help of others to go to the health service were more likely to have problems with accessibility to health services. This information could be one of the first steps to the management and/or planning of appropriate health services for persons with disabilities.

Impact of socioeconomic and clinical factors on child oral health-related quality of life (COHRQoL)

Child oral health-related quality of life (COHRQoL) has been increasingly assessed; however, few studies appraised the influence of socioeconomic status on COHRQoL in developing countries. This study assessed the relationship of COHRQoL with socioeconomic backgrounds and clinical factors. This study followed a cross-sectional design, with a multistage random sample of 792 schoolchildren aged 12 years, representative of Santa Maria, a southern city in Brazil. Participants completed the Brazilian version of the Child Perceptions Questionnaire (CPQ(11-14)), their parents or guardians answered questions on socioeconomic status, and a dental examination provided information on the prevalence of caries, dental trauma and occlusion. The assessment of association used hierarchically adjusted Poisson regression models. Higher impacts on COHRQoL were observed for children presenting with untreated dental caries (RR 1.20; 95% CI 1.07-1.35) and maxillary overjet (RR 1.19; 95% CI 1.02-1.40). Socioeconomic factors also associated with COHRQoL; poorer scores were reported by children whose mothers have not completed primary education (RR 1.30; 95% CI 1.17-1.44) and those with lower household income (RR 1.13; 95% CI 1.02-1.26). Poor socioeconomic standings and poor dental status have a negative impact on COHRQoL; reducing health inequalities may demand dental programmes and policies targeting deprived population.

Sex and socioeconomic inequalities of lung cancer mortality in Barcelona, Spain and Sao Paulo, Brazil

The objective of this paper was to assess sex and socioeconomic inequalities in lung cancer mortality in two major cities of Europe and South America. Official information on mortality and population allowed the estimation of sex- and age-specific death rates for Barcelona, Spain and Sao Paulo, Brazil (1995-2003). Mortality trends and levels were independently assessed for each city and subsequently compared. Rate ratios assessed by Poisson regression analysis addressed hypotheses of association between the outcome and socioeconomic covariates (human development index, unemployment and schooling) at the inner-city area level. Barcelona had a higher mortality in men (76.9/100000 inhabitants) than Sao Paulo (38.2/100 000 inhabitants); although rates were decreasing for the former (-2%/year) and levelled-off for the [after. Mortality in women ranked similarly (9.1 for Barcelona, 11.5 for Sao Paulo); with an increasing trend for women aged 35-64 years (+ 7.7%/year in Barcelona and + 2.4%/year in Sao Paulo). The socioeconomic gradient of mortality in men was negative for Barcelona and positive for Sao Paulo; for women, the socioeconomic gradient was positive in both cities. Negative gradients indicate that deprived areas suffer a higher burden of disease; positive gradients suggest that prosmoking lifestyles may have been more prevalent in more affluent areas during the last decades. Sex and socioeconomic inequalities of lung cancer mortality reinforce the hypothesis that the epidemiologic profile of cancer can be improved by an expanded access to existing technology of healthcare and prevention. The continuous monitoring of inequalities in health may contribute to the concurrent promotion of well-being and social justice.

Dietary calcium intake and overweight: An epidemiologic view

Objective: We evaluated the relation between overweight and calcium intake in adults living in the municipality of Sao Paulo, Brazil. Methods: This was a cross-sectional population-based Study on a sample of 1459 adults that was obtained by multistage cluster sampling. Dietary intake was measured by the 24-h recall method. Poisson`s and linear regression analyses were performed to evaluate the relation between overweight and quartiles of calcium intake adjusted for energy. Results: The prevalence of overweight was 43.1% and the average adjusted calcium intake was 448.6 mg. In the linear regression. analyses, the regression coefficient for adjusted calcium was significant and negative (P = 0.019, beta(1) = -0.0001). Although evaluated by quartiles, the prevalence ratio for overweight in the first quartile of calcium intake was 1.24 (95% confidence interval 1.00-1.54) and that in the second quartile was 1.24 (95% confidence interval 1.03-1.49). Conclusion: In the present study, calcium intake showed a significant negative association with body mass index. (C) 2008 Elsevier Inc. All rights reserved.

Self-rated oral health and associated factors in Brazilian elders

Objective: Self-rating provides a simple direct way of capturing perceptions of health. The objective of this study was to estimate the prevalence and associated factors of poor self-rated oral health among elders. Methods: National data from a cross-sectional population-based study with a multistage random sample of 4786 Brazilian older adults (aged 65-74) in 250 towns were analysed. Data collection included oral examinations (WHO 1997) and struct-ured interviews at elderly households. The outcome was measured by a single five-point-response-scale question dichotomized into `poor` (fair/poor/very poor) and `good` (good/very good) self-rated oral health. Data analyses used Poisson regression models stratified by sex. Results: The prevalence of poor self-rated oral health was 46.6% (95% CI: 45.2-48%) in the whole sample, 50.3% (48-52.5) in men and 44.2% (42.4-46) in women. Higher prevalence ratios (PR) were found in elders reporting unfavourable dental appearance (PR = 2.31; 95% CI: 2.02-2.65), poor chewing ability (PR = 1.64; CI: 1.48-1.8) and dental pain (PR = 1.44; CI: 1.04-1.23) in adjusted analysis. Poor self-perception was also associated with being men, black, unfavourable socioeconomic circumstances, unfavourable clinical oral health and with not using or needing a dental prosthesis. Conclusion: Assessment and understanding of self-rated oral health should take into account social factors, subjective and clinical oral symptoms.

Overweight and obesity related factors in schoolchildren in Santa Catarina State, Brazil

The purpose of this study is to determine the correlation of socioeconomic, dietary, and anthropometric-nutritional variables of parents and their children to overweight (including obesity) in schoolchildren in Santa Catarina State, Brazil. This is a transversal study conducted on 4,964, 6 to 10-year-old schoolchildren registered in 345 Santa Catarina elementary schools. The following data were acquired: the children`s current weight and height, birth weight and length, duration of breastfeeding, age at which water, herbal tea and other foods were introduced to their diet; parental income, education level, age, weight and height were also obtained. The prevalence of overweight and obese children were estimated by point and by interval with a 95% confidence; prevalence rates were obtained based on the Poisson model. An hierarchical approach was used, in which variables were adjusted within blocks and included in the model when they presented p<0.05 at the outcome (overweight including obesity). The results indicate that 47.8% of the subjects were male. The prevalence of overweight and obese students was 15.4% (C195%: 14.4%-16.5%) and 6.1% (CI95%: 5.4%-6.7%) respectively and were statistically similar among sexes and age ranges. BMI values were higher in males and among older children (p<0.05). After adjustment within and among blocks, the variables per capita household income and parents` BM I values remained associated with overweight (including obesity). Overweight (including obesity) in schoolchildren is associated with a higher per capita household income and parental overweight and obesity.

Moho map of South America from receiver functions and surface waves

We estimate crustal structure and thickness of South America north of roughly 40 degrees S. To this end, we analyzed receiver functions from 20 relatively new temporary broadband seismic stations deployed across eastern Brazil. In the analysis we include teleseismic and some regional events, particularly for stations that recorded few suitable earthquakes. We first estimate crustal thickness and average Poisson`s ratio using two different stacking methods. We then combine the new crustal constraints with results from previous receiver function studies. To interpolate the crustal thickness between the station locations, we jointly invert these Moho point constraints, Rayleigh wave group velocities, and regional S and Rayleigh waveforms for a continuous map of Moho depth. The new tomographic Moho map suggests that Moho depth and Moho relief vary slightly with age within the Precambrian crust. Whether or not a positive correlation between crustal thickness and geologic age is derived from the pre-interpolation point constraints depends strongly on the selected subset of receiver functions. This implies that using only pre-interpolation point constraints (receiver functions) inadequately samples the spatial variation in geologic age. The new Moho map also reveals an anomalously deep Moho beneath the oldest core of the Amazonian Craton.