A Comparison of Four Probability-Based Online and Mixed-Mode Panels in Europe

Inferential statistics teach us that we need a random probability sample to infer from a sample to the general population. In online survey research, however, volunteer access panels, in which respondents self-select themselves into the sample, dominate the landscape. Such panels are attractive due to their low costs. Nevertheless, recent years have seen increasing numbers of debates about the quality, in particular about errors in the representativeness and measurement, of such panels. In this article, we describe four probability-based online and mixed-mode panels for the general population, namely, the Longitudinal Internet Studies for the Social Sciences (LISS) Panel in the Netherlands, the German Internet Panel (GIP) and the GESIS Panel in Germany, and the Longitudinal Study by Internet for the Social Sciences (ELIPSS) Panel in France. We compare them in terms of sampling strategies, offline recruitment procedures, and panel characteristics. Our aim is to provide an overview to the scientific community of the availability of such data sources to demonstrate the potential strategies for recruiting and maintaining probability-based online panels to practitioners and to direct analysts of the comparative data collected across these panels to methodological differences that may affect comparative estimates

Dose dependent effect of statins on postoperative atrial fibrillation after cardiac surgery among patients treated with beta blockers

<p>Abstract</p> <p>Background</p> <p>Previous studies on the effects of Statins in preventing atrial fibrillation (AF) after cardiac surgery have shown conflicting results. Whether statins prevent AF in patients treated with postoperative beta blockers and whether the statin-effect is dose related are unknown.</p> <p>Methods</p> <p>We retrospectively studied 1936 consecutive patients who underwent coronary artery bypass graft (CABG) (n = 1493) or valve surgery (n = 443) at the Minneapolis Veterans Affairs Medical Center. All patients were in sinus rhythm before the surgery. Postoperative beta blockers were administered routinely (92% within 24 hours postoperatively).</p> <p>Results</p> <p>Mean age was 66+10 years and 68% of the patients were taking Statins. Postoperative AF occurred in 588 (30%) patients and led to longer length of stay in the intensive care unit versus those without AF (5.1+7.6 days versus 2.5+2.3 days, p < 0.0001). Patients with a past history of AF had a 5 times higher risk of postoperative AF (odds ratio 5.1; 95% confidence interval 3.4 to 7.7; p < 0.0001). AF occurred in 31% of patients taking statins versus 29% of the others (p = 0.49). In multivariable analysis, statins were not associated with AF (odds ratio (OR) 0.93, 95% confidence interval (CI) 0.7 to 1.2; p = 0.59). However, in a subgroup analysis, the patients treated with Simvastatin >20 mg daily had a 36% reduction in the risk of postoperative AF (OR 0.64, 95% CI 0.43 to 0.6; p = 0.03) in comparison to those taking lower dosages.</p> <p>Conclusion</p> <p>Among cardiac surgery patients treated with postoperative beta blockers Statin treatment reduces the incidence of postoperative AF when used at higher dosages</p

Real-Time Definition of Non-Randomness in the Distribution of Genomic Events

Features such as mutations or structural characteristics can be non-randomly or non-uniformly distributed within a genome. So far, computer simulations were required for statistical inferences on the distribution of sequence motifs. Here, we show that these analyses are possible using an analytical, mathematical approach. For the assessment of non-randomness, our calculations only require information including genome size, number of (sampled) sequence motifs and distance parameters. We have developed computer programs evaluating our analytical formulas for the real-time determination of expected values and p-values. This approach permits a flexible cluster definition that can be applied to most effectively identify non-random or non-uniform sequence motif distribution. As an example, we show the effectivity and reliability of our mathematical approach in clinical retroviral vector integration site distribution

Phenomenological Analysis of the Kinematic Hardening of HSLA and IF Steels Using Reverse Simple Shear Tests

International audienc

Hardening in relation with microstructure evolution of high purity α-titanium deformed under monotonic and cyclic simple shear loadings at room temperature

International audienceThe aim of this paper is to gain understanding of the quasi-static, large strain deformation behavior at room-temperature of high-purity α-Ti with an initial split-basal texture. Simple shear tests were conducted along different directions in order to quantify the material's anisotropy and hardening evolution for different strain paths such as monotonic, Bauschinger, and cyclic loadings. The stress–strain curves indicate that the material displays strong anisotropy in the flow behavior. In order to capture the link between microstructure evolution (occurrence of twinning, grain size evolution, etc.) and the macroscopic response, a thoroughly detailed multi-scale characterization using scanning electron microscope (SEM) observations and electron backscattered diffraction (EBSD) analysis was also conducted. Specifically, EBSD analyses indicate that the twin activity and grain fragmentation are responsible for the observed difference between the macroscopic hardening rates corresponding to different directions and loading paths

Endoscopic third ventriculostomy: Complications and avoidance

Introduction. Endoscopic third ventriculostomy (ETV) is the treatment of choice in obstructive hydrocephalus. It has become the main standard choice in management since 1962. However, there is scant data regarding the complications from clinical or multi-centre trials. This study highlights the specific complications and prevention methods related to ETV in Neurosurgical Teaching Hospital, Baghdad, Iraq. Methods. It is a prospective case series study conducted on cases in the Neurosurgical Teaching Hospital in Baghdad, Iraq, from January 2014- October 2019. We selected ninety patients. The sample selection was convenient as any patients admitted in the study period who met the selection criteria were included. All included patients underwent a Computerized Tomography scan or Magnetic Resonance Imaging in the periprocedural management. Results. Ninety cases have 59 (65.5%) females and 31 (34.5%) males. The most common cause of hydrocephalus is congenital causes (51 cases (56.6%), especially within the first decade of life. Aqueduct stenosis is the leading cause in 37 cases (72%). ETV complications were found in 32 cases (35.5%). The most common cause of complications is congenital cases of 14 (15%). Intraoperative complications include bleeding (mild, moderate, and severe) in 18 cases (20%). Mild bleeding constitutes 15 cases (16.6%) of all complicated cases. Conclusion. ETV is a standard procedure in the management of obstructive hydrocephalus. The complication rate is found in around one-third of the cases in our study. Surgeons’ selection of indicated patients and better surgical experience decrease the failure rate of ETV and complications

Mobilization of the temporal pole as integrated step in microsurgical clipping of pure posteriorly directed posterior communicating artery aneurysm

A pure posteriorly posterior communicating artery (PCoA) aneurysm represents a surgical challenge. This is mainly when there is a need for good exposure of the aneurysmal neck, sac, PCoA, and anterior choroidal arteries. Ruptured pure posteriorly directed PCoA aneurysm imposes significantly extra challenge as the surgeon undergoes dissection through a tight brain. Even with measures commonly used to attain brain relaxation like the lumbar drain and cisternal fenestration. Here, we describe a technique for posterior temporal pole mobilization (TPM) as an integrated part of microsurgical clipping of ruptured pure posteriorly directed PCoA aneurysms. This technique is implicated in twenty-three successive cases of ruptured PCoA aneurysms in the neurosurgery teaching hospital in Baghdad, Iraq, with no reported complications

Bacterial community issued from a Chlorophytum plant-microbial fuel cell for electricity generation

Some microorganisms, particularly bacteria, can adhere to conductive surfaces and grow as an electroactive biofilm, on which they communicate electrochemically and generate electricity. Here, a bacterial community isolated from anodic electroactive biofilms of a Microbial Fuel Cell planted with Chlorophytum comosom is studied. Seventeen different bacterial strains were isolated from electroactive biofilms and were identified using the 16S rRNA marker gene. The strains were affiliated to 8 bacteria families and 8 genera (Aeromonas, Enterobacter, Alcaligenes, Pseudomonas, Clostridium, Paraclostridium, Enterococcus and Kurthia spp.). After that, it was demonstrated using electrochemical methods, principally imposed potential chronoamperometry under +0.155 mV/SCE, that the consortium constituted of 17 strains was able to exchange electrons with conductive materials. A maximum current density of 345 µA/cm2 was revealed at 48h of the study, using acetate as the sole carbon source and without any additional external mediator.SCOPUS: ar.jinfo:eu-repo/semantics/publishe