Search results for "statistical [methods]"
showing 10 items of 1664 documents
A novel arousal-based individual screening reveals susceptibility and resilience to PTSD-like phenotypes in mice
2021
Translational animal models for studying post-traumatic stress disorder (PTSD) are valuable for elucidating the poorly understood neurobiology of this neuropsychiatric disorder. These models should encompass crucial features, including persistence of PTSD-like phenotypes triggered after exposure to a single traumatic event, trauma susceptibility/resilience and predictive validity. Here we propose a novel arousal-based individual screening (AIS) model that recapitulates all these features. The AIS model was designed by coupling the traumatization (24 h restraint) of C57BL/6 J mice with a novel individual screening. This screening consists of z-normalization of post-trauma changes in startle …
Modic changes-Their associations with low back pain and activity limitation: A systematic literature review and meta-analysis.
2018
Background Previous systematic reviews have reported positive associations between Modic changes (MCs) and low back pain (LBP), but due to their narrow scope and new primary studies, there is a need for a comprehensive systematic review. Our objectives were to investigate if MCs are associated with non-specific LBP and/or activity limitation and if such associations are modified by other factors. Methods A protocol for this review was registered at PROSPERO prior to commencing the work (PROSPERO record: CRD42015017350). The MEDLINE, CINAHL and EMBASE databases were searched for relevant studies from first record to June 15th 2016. Prospective or retrospective cross-sectional cohort studies …
Comparison of piezosurgery and conventional rotary instruments in schneider’s membrane sinus lifting: A pilot randomized trial
2020
Background The present study aimed to evaluate and compare the postoperative effects of the piezoelectric device and conventional rotary instruments in Schneider’s membrane sinus lifting procedure. Material and Methods Twenty patients requiring bilateral maxillary bone graft augmentation in the posterior maxillary region were selected. Piezoelectric surgery was performed on one side and conventional surgery with a rotary diamond bur on the other. Postoperative pain, swelling, edema, and mouth opening were evaluated at one hour and two and seven days after the procedures. All variables were submitted to Friedman or Wilcoxon tests at a 5% significance level. Results The comparison between gro…
Comparison of the clinical effects of white brand toothbrushes versus Vitis Suave®
2015
Background: There has been an increase in the use of white label manual toothbrushes and a greater increase in inquiries for discomfort of the gingiva and mucosa. Material and Methods: A randomized, double-blind, cross-over clinical trial was made of four white brand toothbrushes versus a control brush (Vitis Suave®), with the recording of plaque index, bleeding upon probing, and gingival abrasions following utilization of the different brushes. Results: All the brushes except Deliplus® were equally effective in terms of plaque removal ( p <0.05). Vitis Suave® and Veckia® were the brushes associated to the greatest increase in minor abrasions ( p <0.01), while Veckia®, Carrefour® and Deluxe…
The Rhetoric and Relevance of IS Research Paradigms: Conceptual Foundations and Empirical Evidence
2006
This paper discusses the relevance of IS research with respect to the rhetoric associated with the three major IS research paradigms in use - positivism, constructivism/interpretivism and critical research. The conceptual discussion is framed in terms of the following dimensions: ontological, epistemological and methodological assumptions, relationship between theory and practice, and the role of the researcher in the research process. Based on this discussion, we propose a conceptual model to study the relationship between the espoused philosophical assumptions of researchers and the degree of relevance of researchers’ knowledge claims. This conceptual model was evaluated with data obtaine…
Tools for education : policy analysis
2003
03125http://www-wds.worldbank.org/servlet/WDSContentServer/WDSP/IB/2003/06/06/000094946_03052904033567/Rendered/PDF/multi0page.pdf; This hands-on, interactive guide to evaluating and revamping education policy is designed to help policymakers in low-income countries identify weakness and make the most efficient use of scarce education resources. Education specialist in the developed world will also find this guide to be an invaluable tool for analyzing priorities and arriving at cost-effective solutions. The out-growth of training workshops held at the World Bank, this book and CD-ROM present relevant policy problems and engage the user in a search for effective education-service delivery o…
Enhanced transport-related air pollution prediction through a novel metamodel approach
2017
Abstract This research proposes a novel approach to improve the ability to forecast low frequency extreme events of transport-related pollution in urban areas using a limited input data set. The approach is based on the idea of a self-managing model, able to adapt to unexpected changes in pollution level. In more detail, for a given combination of variables, it selects the most suitable prediction model within a set of alternative air quality models, estimated for a wider range of locations and conditions. In this study, the new approach is tested for the prediction of nitrogen dioxide concentration in the United Kingdom (UK), specifically in an air quality monitoring site of the Greater Ma…
Single-chain conformations in symmetric binary polymer blends: Quantitative comparison between self-consistent field calculations and Monte Carlo sim…
1998
Single-chain properties in a symmetric binary polymer blend are studied by self-consistent field calculations and Monte Carlo simulations. Within the self-consistent field scheme, the statistical mechanics of a cluster of neighboring polymers is solved. Interactions among the polymers of a cluster and composition fluctuations within a cluster are incorporated exactly, a mean field approximation is invoked for intercluster interactions and long-range fluctuations. The results are compared to large scale Monte Carlo simulations for a broad range of chain lengths. While we find nearly quantitative agreement for single chain propertiese.g., the reduction of the chain dimensions of the minority …
A Monte Carlo Study of Knots in Long Double-Stranded DNA Chains.
2016
We determine knotting probabilities and typical sizes of knots in double-stranded DNA for chains of up to half a million base pairs with computer simulations of a coarse-grained bead-stick model: Single trefoil knots and composite knots which include at least one trefoil as a prime factor are shown to be common in DNA chains exceeding 250,000 base pairs, assuming physiologically relevant salt conditions. The analysis is motivated by the emergence of DNA nanopore sequencing technology, as knots are a potential cause of erroneous nucleotide reads in nanopore sequencing devices and may severely limit read lengths in the foreseeable future. Even though our coarse-grained model is only based on …
Polynomial Regression and Measurement Error
2020
Many of the phenomena of interest in information systems (IS) research are nonlinear, and it has consequently been recognized that by applying linear statistical models (e.g., linear regression), we may ignore important aspects of these phenomena. To address this issue, IS researchers are increasingly applying nonlinear models to their datasets. One popular analytical technique for the modeling and analysis of nonlinear relationships is polynomial regression, which in its simplest form fits a "U-shaped" curve to the data. However, the use of polynomial regression can be problematic when the independent variables are contaminated with measurement error, and the implications of error can be m…