EUROCAT website data on prenatal detection rates of congenital anomalies.

The EUROCAT website www.eurocat-network.eu publishes prenatal detection rates for major congenital anomalies using data from European population-based congenital anomaly registers, covering 28% of the EU population as well as non-EU countries. Data are updated annually. This information can be useful for comparative purposes to clinicians and public health service managers involved in the antenatal care of pregnant women as well as those interested in perinatal epidemiology.

Intermittent atrial tachycardia promotes repolarization alternans and conduction slowing during rapid rates, and increases susceptibility to atrial fibrillation in a free-behaving sheep model.

INTRODUCTION: Paroxysmal atrial fibrillation (AF) may be triggered by intermittent atrial tachycardia, and ultimately lead to persistent AF. However, the mechanisms by which intermittent atrial tachycardia promotes sustained AF are not well understood. METHODS AND RESULTS: Eight sheep were chronically implanted with 2 pacemakers for the recording of broadband right atrial unipolar electrograms, and for the delivery of electrophysiological stimulation protocols and intermittent right atrial tachycardia. Right atrial kinetics of activation recovery interval (ARI) as a surrogate for action potential duration, of conduction time and velocity, and of repolarization alternans were analyzed at incremental pacing rates during the remodeling process induced by weeks of intermittent atrial tachycardia until the development of sustained AF. Intermittent atrial tachycardia decreased ARI and blunted its rate adaptation, facilitated atrial capture, and slowed conduction at high rates, and increased susceptibility to pacing-induced AF. In spite of blunted ARI rate adaptation, right atrial repolarization alternans was maintained during remodeling, and further increased in magnitude just before rapid pacing-induced AF. CONCLUSION: This study suggests that weeks of intermittent right atrial tachycardia result in a gradual electrical remodeling favorable for wavebreaks and reentry that may facilitate fibrillation.

The political economy of childcare in OECD countries : Explaining cross-national variation in spending and coverage rates

If childcare policy has become topical in most OECD countries over the last ten years or so, actual developments display huge cross-national variations. Countries like Sweden and Denmark spend around 2 per cent of GDP on this service, and provide affordable childcare places to most children below school age. At the other extreme, in Southern Europe, only around 10 per cent of this age group has access to formal daycare. Against this background, this article aims to account for cross-national variations in childcare services. It distinguishes two dependent variables: the coverage rate and the proportion of GDP spent subsidising childcare services. Using a mix of cross-sectional and pooled times-series methods, it tests a series of hypotheses concerning the determinants of the development of this policy. Its main conclusion for the coverage rate is that key factors are public spending and wage dispersion (both positive). For spending, key factors are the proportion of women in parliaments (positive) and spending on age-related policies (negative).

Rates of cultural change and patterns of cultural accumulation in stochastic models of social transmission.

Cultural variation in a population is affected by the rate of occurrence of cultural innovations, whether such innovations are preferred or eschewed, how they are transmitted between individuals in the population, and the size of the population. An innovation, such as a modification in an attribute of a handaxe, may be lost or may become a property of all handaxes, which we call "fixation of the innovation." Alternatively, several innovations may attain appreciable frequencies, in which case properties of the frequency distribution-for example, of handaxe measurements-is important. Here we apply the Moran model from the stochastic theory of population genetics to study the evolution of cultural innovations. We obtain the probability that an initially rare innovation becomes fixed, and the expected time this takes. When variation in cultural traits is due to recurrent innovation, copy error, and sampling from generation to generation, we describe properties of this variation, such as the level of heterogeneity expected in the population. For all of these, we determine the effect of the mode of social transmission: conformist, where there is a tendency for each naïve newborn to copy the most popular variant; pro-novelty bias, where the newborn prefers a specific variant if it exists among those it samples; one-to-many transmission, where the variant one individual carries is copied by all newborns while that individual remains alive. We compare our findings with those predicted by prevailing theories for rates of cultural change and the distribution of cultural variation.

Simple estimation of incident HIV infection rates in notification cohorts based on window periods of algorithms for evaluation of line-immunoassay result patterns.

BACKGROUND: Tests for recent infections (TRIs) are important for HIV surveillance. We have shown that a patient's antibody pattern in a confirmatory line immunoassay (Inno-Lia) also yields information on time since infection. We have published algorithms which, with a certain sensitivity and specificity, distinguish between incident (< = 12 months) and older infection. In order to use these algorithms like other TRIs, i.e., based on their windows, we now determined their window periods. METHODS: We classified Inno-Lia results of 527 treatment-naïve patients with HIV-1 infection < = 12 months according to incidence by 25 algorithms. The time after which all infections were ruled older, i.e. the algorithm's window, was determined by linear regression of the proportion ruled incident in dependence of time since infection. Window-based incident infection rates (IIR) were determined utilizing the relationship 'Prevalence = Incidence x Duration' in four annual cohorts of HIV-1 notifications. Results were compared to performance-based IIR also derived from Inno-Lia results, but utilizing the relationship 'incident = true incident + false incident' and also to the IIR derived from the BED incidence assay. RESULTS: Window periods varied between 45.8 and 130.1 days and correlated well with the algorithms' diagnostic sensitivity (R(2) = 0.962; P<0.0001). Among the 25 algorithms, the mean window-based IIR among the 748 notifications of 2005/06 was 0.457 compared to 0.453 obtained for performance-based IIR with a model not correcting for selection bias. Evaluation of BED results using a window of 153 days yielded an IIR of 0.669. Window-based IIR and performance-based IIR increased by 22.4% and respectively 30.6% in 2008, while 2009 and 2010 showed a return to baseline for both methods. CONCLUSIONS: IIR estimations by window- and performance-based evaluations of Inno-Lia algorithm results were similar and can be used together to assess IIR changes between annual HIV notification cohorts.

Obesity and overweight associated with lower rates of colorectal cancer screening in Switzerland.

Screening for colorectal cancer (CRC) is associated with reduced CRC mortality, but low screening rates have been reported in several settings. The aim of the study was to assess predictors of low CRC screening in Switzerland. A retrospective cohort of a random sample of 940 patients aged 50-80 years followed for 2 years from four Swiss University primary care settings was used. Patients with illegal residency status and a history of CRC or colorectal polyps were excluded. We abstracted sociodemographic data of patients and physicians, patient health status, and indicators derived from RAND's Quality Assessment Tools from medical charts. We defined CRC screening as colonoscopy in the last 10 years, flexible sigmoidoscopy in the last 5 years, or fecal occult blood testing in the last 2 years. We used bivariate and multivariate logistic regression analyses. Of 940 patients (mean age 63.9 years, 42.7% women), 316 (33.6%) had undergone CRC screening. In multivariate analysis, birthplace in a country outside of Western Europe and North America [odds ratio (OR) 0.65, 95% confidence interval (CI) 0.45-0.97], male sex of the physician in charge (OR 0.67, 95% CI 0.50-0.91), BMI 25.0-29.9 kg/m (OR 0.66, CI 0.46-0.96) and at least 30.0 kg/m (OR 0.61, CI 0.40-0.90) were associated with lower CRC screening rates. Obesity, overweight, birthplace outside of Western Europe and North America, and male sex of the physician in charge were associated with lower CRC screening rates in Swiss University primary care settings. Physician perception of obesity and its impact on their recommendation for CRC screening might be a target for further research.

In vivo loading increases mechanical properties of scaffold by affecting bone formation and bone resorption rates.

A successful bone tissue engineering strategy entails producing bone-scaffold constructs with adequate mechanical properties. Apart from the mechanical properties of the scaffold itself, the forming bone inside the scaffold also adds to the strength of the construct. In this study, we investigated the role of in vivo cyclic loading on mechanical properties of a bone scaffold. We implanted PLA/β-TCP scaffolds in the distal femur of six rats, applied external cyclic loading on the right leg, and kept the left leg as a control. We monitored bone formation at 7 time points over 35 weeks using time-lapsed micro-computed tomography (CT) imaging. The images were then used to construct micro-finite element models of bone-scaffold constructs, with which we estimated the stiffness for each sample at all time points. We found that loading increased the stiffness by 60% at 35 weeks. The increase of stiffness was correlated to an increase in bone volume fraction of 18% in the loaded scaffold compared to control scaffold. These changes in volume fraction and related stiffness in the bone scaffold are regulated by two independent processes, bone formation and bone resorption. Using time-lapsed micro-CT imaging and a newly-developed longitudinal image registration technique, we observed that mechanical stimulation increases the bone formation rate during 4-10 weeks, and decreases the bone resorption rate during 9-18 weeks post-operatively. For the first time, we report that in vivo cyclic loading increases mechanical properties of the scaffold by increasing the bone formation rate and decreasing the bone resorption rate.

Active intravenous drug use during chronic hepatitis C therapy does not reduce sustained virological response rates in adherent patients.

SUMMARY: Reluctance has been expressed about treating chronic hepatitis C in active intravenous (IV) drug users (IDUs), and this is found in both international guidelines and routine clinical practice. However, the medical literature provides no evidence for an unequivocal treatment deferral of this risk group. We retrospectively analyzed the direct effect of IV drug use on treatment outcome in 500 chronic hepatitis C patients enrolled in the Swiss Hepatitis C Cohort Study. Patients were eligible for the study if they had their serum hepatitis C virus (HCV) RNA tested 6 months after the end of treatment and at least one visit during the antiviral therapy, documenting the drug use status. Five hundred patients fulfilled the inclusion criteria (199 were IDU and 301 controls). A minimum exposure to 80% of the scheduled cumulative dose of antivirals was reached in 66.0% of IDU and 60.5% of controls (P = NS). The overall sustained virological response (SVR) rate was 63.6%. Active IDU reached a SVR of 69.3%, statistically not significantly different from controls (59.8%). A multivariate analysis for treatment success showed no significant negative influence of active IV drug use. In conclusion, our study shows no relevant direct influence of IV drugs on the efficacy of anti-HCV therapy among adherent patients.

PyRate: a new program to estimate speciation and extinction rates from incomplete fossil data

Despite the advancement of phylogenetic methods to estimate speciation and extinction rates, their power can be limited under variable rates, in particular for clades with high extinction rates and small number of extant species. Fossil data can provide a powerful alternative source of information to investigate diversification processes. Here, we present PyRate, a computer program to estimate speciation and extinction rates and their temporal dynamics from fossil occurrence data. The rates are inferred in a Bayesian framework and are comparable to those estimated from phylogenetic trees. We describe how PyRate can be used to explore different models of diversification. In addition to the diversification rates, it provides estimates of the parameters of the preservation process (fossilization and sampling) and the times of speciation and extinction of each species in the data set. Moreover, we develop a new birth-death model to correlate the variation of speciation/extinction rates with changes of a continuous trait. Finally, we demonstrate the use of Bayes factors for model selection and show how the posterior estimates of a PyRate analysis can be used to generate calibration densities for Bayesian molecular clock analysis. PyRate is an open-source command-line Python program available at http://sourceforge.net/projects/pyrate/.

Evolutionary rates of Jurassic ammonites in relation to sea-level fluctuations

An analysis is presented of the diversity and faunal turnover of Jurassic ammonites related to transgressive /regressive events. The data set contained 400 genera and 1548 species belonging to 67 ammonite zones covering the entire Jurassic System. These data were used in the construction of faunal turnover curves and ammonite diversities, that correlate with sea-level fluctuation curves. Twenty-four events of ammonite faunal turnover are analyzed throughout the Jurassic. The most important took place at the Sinemurian-Carixian boundary, latest Carixian-Middle Domerian, Domerian-Toarcian boundary, latest Middle Toarcian-Late Toarcian, Toarcian-Aalenian boundary, latest Aalenian-earliest Bajocian, latest Early Bajocian-earliest Late Bojocian, Early Bathonian-Middle Bathonian boundary, latest Middle Bathonian-earliest Late Bathonian, latest Bathonian-Early Callovian, earliest Early Oxfordian-Middle Oxfordian, earliest Late Oxfordian-latest Oxfordian, latest Early Kimmeridgian, Late Kimmeridgian, middle Early Tithonian and Early Tithonian-Late Tithonian boundary. More than 75 percent of these turnovers correlate with regressive-transgressive cycles in the Exxon, and /or Hallam's sea-level curves. Inmost cases the extinction events coincide with regressive intervals, whereas origination and radiation events are related to transgressive cycles. The turnovers frequently coincide with major or minor discontinuities in the Subbetic basin (Betic Cordillera).

The role of climatic tolerances and seed traits in reduced extinction rates of temperate polygonaceae.

The latitudinal diversity gradient (LDG) is one of the most striking and consistent biodiversity patterns across taxonomic groups. We investigate the species richness gradient in the buckwheat family, Polygonaceae, which exhibits a reverse LDG and is, thus, decoupled from dominant gradients of energy and environmental stability that increase toward the tropics and confound mechanistic interpretations. We test competing age and evolutionary diversification hypotheses, which may explain the diversification of this plant family over the past 70 million years. Our analyses show that the age hypothesis, which posits that clade richness is positively correlated with the ecological and evolutionary time since clade origin, fails to explain the richness gradient observed in Polygonaceae. However, an evolutionary diversification hypothesis is highly supported, with diversification rates being 3.5 times higher in temperate clades compared to tropical clades. We demonstrate that differences in rates of speciation, migration, and molecular evolution insufficiently explain the observed patterns of differential diversification rates. We suggest that reduced extinction rates in temperate clades may be associated with adaptive responses to selection, through which seed morphology and climatic tolerances potentially act to minimize risk in temporally variable environments. Further study is needed to understand causal pathways among these traits and factors correlated with latitude.