Experience in using the excimer laser-assisted nonocclusive anastomosis nonocclusive bypass technique for high-flow revascularization: Mannheim-Helsinki series of 64 patients

The excimer laser-assisted nonocclusive anastomosis (ELANA) technique enables large-caliber bypass revascularization without temporary occlusion of the parent artery.

Dynamics of Shifting Cultivation Landscapes in Northern Lao PDR Between 2000 and 2009 Based on an Analysis of MODIS Time Series and Landsat Images

The rotational nature of shifting cultivation poses several challenges to its detection by remote sensing. Consequently, there is a lack of spatial data on the dynamics of shifting cultivation landscapes on a regional, i.e. sub-national, or national level. We present an approach based on a time series of Landsat and MODIS data and landscape metrics to delineate the dynamics of shifting cultivation landscapes. Our results reveal that shifting cultivation is a land use system still widely and dynamically utilized in northern Laos. While there is an overall reduction in the areas dominated by shifting cultivation, some regions also show an expansion. A review of relevant reports and articles indicates that policies tend to lead to a reduction while market forces can result in both expansion and reduction. For a better understanding of the different factors affecting shifting cultivation landscapes in Laos, further research should focus on spatially explicit analyses.

Structure-activity relationships from in vitro efficacies of the thiazolide series against the intracellular apicomplexan protozoan Neospora caninum

Nitazoxanide (2-acetolyloxy-N-(5-nitro 2-thiazolyl) benzamide; NTZ) represents the parent compound of a novel class of broad-spectrum anti-parasitic compounds named thiazolides. NTZ is active against a wide variety of intestinal and tissue-dwelling helminths, protozoa, enteric bacteria and a number of viruses infecting animals and humans. While potent, this poses a problem in practice, since this obvious non-selectivity can lead to undesired side effects in both humans and animals. In this study, we used real time PCR to determine the in vitro activities of 29 different thiazolides (NTZ-derivatives), which carry distinct modifications on both the thiazole- and the benzene moieties, against the tachyzoite stage of the intracellular protozoan Neospora caninum. The goal was to identify a highly active compound lacking the undesirable nitro group, which would have a more specific applicability, such as in food animals. By applying self-organizing molecular field analysis (SOMFA), these data were used to develop a predictive model for future drug design. SOMFA performs self-alignment of the molecules, and takes into account the steric and electrostatic properties, in order to determine 3D-quantitative structure activity relationship models. The best model was obtained by overlay of the thiazole moieties. Plotting of predicted versus experimentally determined activity produced an r2 value of 0.8052 and cross-validation using the "leave one out" methodology resulted in a q2 value of 0.7987. A master grid map showed that large steric groups at the R2 position, the nitrogen of the amide bond and position Y could greatly reduce activity, and the presence of large steric groups placed at positions X, R4 and surrounding the oxygen atom of the amide bond, may increase the activity of thiazolides against Neospora caninum tachyzoites. The model obtained here will be an important predictive tool for future development of this important class of drugs.

Sleep-wake habits and disorders in a series of 100 adult epilepsy patients--a prospective study

The aim of the study was to assess sleep-wake habits and disorders and excessive daytime sleepiness (EDS) in an unselected outpatient epilepsy population. Sleep-wake habits and presence of sleep disorders were assessed by means of a clinical interview and a standard questionnaire in 100 consecutive patients with epilepsy and 90 controls. The questionnaire includes three validated instruments: the Epworth Sleepiness Scale (ESS) for EDS, SA-SDQ for sleep apnea (SA), and the Ullanlinna Narcolepsy Scale (UNS) for narcolepsy. Sleep complaints were reported by 30% of epilepsy patients compared to 10% of controls (p=0.001). The average total sleep time was similar in both groups. Insufficient sleep times were suspected in 24% of patients and 33% of controls. Sleep maintenance insomnia was more frequent in epilepsy patients (52% vs. 38%, p=0.06), whereas nightmares (6% vs. 16%, p=0.04) and bruxism (10% vs. 19%, p=0.07) were more frequent in controls. Sleep onset insomnia (34% vs. 28%), EDS (ESS >or=10, 19% vs. 14%), SA (9% vs. 3%), restless legs symptoms (RL-symptoms, 18% vs. 12%) and most parasomnias were similarly frequent in both groups. In a stepwise logistic regression model loud snoring and RL-symptoms were found to be the only independent predictors of EDS in epilepsy patients. In conclusion, sleep-wake habits and the frequency of most sleep disorders are similar in non-selected epilepsy patients as compared to controls. In epilepsy patients, EDS was predicted by a history of loud snoring and RL-symptoms but not by SA or epilepsy-related variables (including type of epilepsy, frequency of seizures, and number of antiepileptic drugs).

A multivariate approach for processing magnetization effects in triggered event-related functional magnetic resonance imaging time series

Triggered event-related functional magnetic resonance imaging requires sparse intervals of temporally resolved functional data acquisitions, whose initiation corresponds to the occurrence of an event, typically an epileptic spike in the electroencephalographic trace. However, conventional fMRI time series are greatly affected by non-steady-state magnetization effects, which obscure initial blood oxygen level-dependent (BOLD) signals. Here, conventional echo-planar imaging and a post-processing solution based on principal component analysis were employed to remove the dominant eigenimages of the time series, to filter out the global signal changes induced by magnetization decay and to recover BOLD signals starting with the first functional volume. This approach was compared with a physical solution using radiofrequency preparation, which nullifies magnetization effects. As an application of the method, the detectability of the initial transient BOLD response in the auditory cortex, which is elicited by the onset of acoustic scanner noise, was used to demonstrate that post-processing-based removal of magnetization effects allows to detect brain activity patterns identical with those obtained using the radiofrequency preparation. Using the auditory responses as an ideal experimental model of triggered brain activity, our results suggest that reducing the initial magnetization effects by removing a few principal components from fMRI data may be potentially useful in the analysis of triggered event-related echo-planar time series. The implications of this study are discussed with special caution to remaining technical limitations and the additional neurophysiological issues of the triggered acquisition.

A Nonstationary Negative Binomial Time Series with Time-Dependent Covariates: Enterococcus Counts in Boston Harbor

Boston Harbor has had a history of poor water quality, including contamination by enteric pathogens. We conduct a statistical analysis of data collected by the Massachusetts Water Resources Authority (MWRA) between 1996 and 2002 to evaluate the effects of court-mandated improvements in sewage treatment. Motivated by the ineffectiveness of standard Poisson mixture models and their zero-inflated counterparts, we propose a new negative binomial model for time series of Enterococcus counts in Boston Harbor, where nonstationarity and autocorrelation are modeled using a nonparametric smooth function of time in the predictor. Without further restrictions, this function is not identifiable in the presence of time-dependent covariates; consequently we use a basis orthogonal to the space spanned by the covariates and use penalized quasi-likelihood (PQL) for estimation. We conclude that Enterococcus counts were greatly reduced near the Nut Island Treatment Plant (NITP) outfalls following the transfer of wastewaters from NITP to the Deer Island Treatment Plant (DITP) and that the transfer of wastewaters from Boston Harbor to the offshore diffusers in Massachusetts Bay reduced the Enterococcus counts near the DITP outfalls.

Underestimation of Standard Errors in Multi-Site Time Series Studies

Multi-site time series studies of air pollution and mortality and morbidity have figured prominently in the literature as comprehensive approaches for estimating acute effects of air pollution on health. Hierarchical models are generally used to combine site-specific information and estimate pooled air pollution effects taking into account both within-site statistical uncertainty, and across-site heterogeneity. Within a site, characteristics of time series data of air pollution and health (small pollution effects, missing data, highly correlated predictors, non linear confounding etc.) make modelling all sources of uncertainty challenging. One potential consequence is underestimation of the statistical variance of the site-specific effects to be combined. In this paper we investigate the impact of variance underestimation on the pooled relative rate estimate. We focus on two-stage normal-normal hierarchical models and on under- estimation of the statistical variance at the first stage. By mathematical considerations and simulation studies, we found that variance underestimation does not affect the pooled estimate substantially. However, some sensitivity of the pooled estimate to variance underestimation is observed when the number of sites is small and underestimation is severe. These simulation results are applicable to any two-stage normal-normal hierarchical model for combining information of site-specific results, and they can be easily extended to more general hierarchical formulations. We also examined the impact of variance underestimation on the national average relative rate estimate from the National Morbidity Mortality Air Pollution Study and we found that variance underestimation as much as 40% has little effect on the national average.

ESTIMATING TEMPORAL ASSOCIATIONS IN ELECTROCORTICOGRAPHIC (ECoG) TIME SERIES WITH FIRST ORDER PRUNING

Granger causality (GC) is a statistical technique used to estimate temporal associations in multivariate time series. Many applications and extensions of GC have been proposed since its formulation by Granger in 1969. Here we control for potentially mediating or confounding associations between time series in the context of event-related electrocorticographic (ECoG) time series. A pruning approach to remove spurious connections and simultaneously reduce the required number of estimations to fit the effective connectivity graph is proposed. Additionally, we consider the potential of adjusted GC applied to independent components as a method to explore temporal relationships between underlying source signals. Both approaches overcome limitations encountered when estimating many parameters in multivariate time-series data, an increasingly common predicament in today's brain mapping studies.

Isolated extraordinary daytime urinary frequency of childhood: a case series of 26 children in Switzerland

BACKGROUND: The term 'isolated extraordinary daytime urinary frequency' designates an abnormally increased diurnal frequency of painless urination in a completely toilet-trained child with normal urinalysis. METHODS: We report the history of 26 children (16 boys and 10 girls; aged between 4.1 and 10 years) who were referred to us between 2002 and 2006 and subsequently diagnosed with this condition. RESULTS: Possible psychosocial problems, or recent emotional stressors, were disclosed in the majority of the children: recent (36 months or less) asylum seekers (n = 9), school-related problems (n = 4), parental divorce (n = 2) or death of the mother (n = 1). Possible dietary causes were observed in 9 patients: oxalate-rich beverages (n = 5) and liberal ingestion of 'acidic' juices (n = 4). A diet low in oxalates was recommended when children were consuming large quantities of oxalate-rich beverages; and a diet low in acidic juice was recommended in those liberally ingesting acidic juices. Reassurance and observation were the approach in the remaining cases. The median duration of the symptoms was 5 months. A longer (p < 0.05) duration was noted in children of asylum seekers. CONCLUSIONS: This functional condition is easily identifiable, but often under- or misdiagnosed. Confounding the condition might result in redundant investigation.