Accurate Comparison (accurate + comparison)

Distribution by Scientific Domains

Selected Abstracts

On the evaluation of seismic response of structures by nonlinear static methods

Melina Bosco
Abstract In the most recent seismic codes, the assessment of the seismic response of structures may be carried out by comparing the displacement capacity, provided by nonlinear static analysis, with the displacement demand. In many cases the code approach is based on the N2 method proposed by Fajfar, which evaluates the displacement demand by defining, as an intermediate step, a single degree-of-freedom (SDOF) system equivalent to the examined structure. Other codes suggest simpler approaches, which do not require equivalent SDOF systems, but they give slightly different estimation of the seismic displacement demand. The paper points out the differences between the methods and suggests an operative approach that provides the same accuracy as the N2 method without requiring the evaluation of an equivalent SDOF system. A wide parametric investigation allows an accurate comparison of the different methods and demonstrates the effectiveness of the proposed operative approach. Copyright 2009 John Wiley & Sons, Ltd. [source]

Comparison of efficacy criteria across onychomycosis trials: need for standardization

Aditya K. Gupta MD, FRCP(C)
Background The last 10 years have seen a substantial increase in the number of studies reporting the efficacy of the various antifungal agents used to treat onychomycosis. Aim To examine the definitions of efficacy parameters reported in clinical studies on the treatment of onychomycosis and discuss the importance of standardized reporting. Methods We searched MEDLINE (1966,2001) for studies in which oral treatments, griseofulvin, ketoconazole, terbinafine (continuous and pulse), itraconazole (continuous and pulse), and fluconazole, were used to treat dermatophyte onychomycosis. Results Mycologic cure was predominantly defined as negative microscopy and culture. Unlike mycologic cure, clinical parameters (e.g. clinical response, clinical cure) were variably defined. Subjective terms, such as "cure" or "markedly improved," were used; although these terms appear to be explicit, what is considered to be "cured" or "markedly improved" by one evaluator may not be by another. Also, infected nails were clinically evaluated to determine the response to treatment. Studies measured the distance between the proximal nail fold and a notch in the nail plate, at the junction between the diseased and normal-appearing nail, or in some cases estimated the diseased nail plate involvement. Conclusions This review of the literature on systemic agents used to treat onychomycosis shows that standard and explicit definitions are required for the accurate comparison of the effectiveness of the various therapies. [source]

Nanoscopic characterization of a plastisol gelation and fusion process utilizing scanning electron microscopy and atomic force microscopy

Jerome S. Jourdan
Understanding the physical properties associated with the gelation and fusion of a PVC plastisol will help to improve process efficiency. Plastisol gelation and fusion were characterized by using both scanning electron microscopy (SEM) and atomic force microscopy (AFM) and were compared with the tensile properties developed at various temperatures. Both SEM and AFM showed good agreement during the early stages of gelation. However, AFM continued to show particle boundaries during the latter stages of gelation and fusion that provided a more nearly accurate comparison with the resulting tensile properties. J. VINYL ADDIT. TECHNOL., 2008. 2008 Society of Plastics Engineers. [source]

Use of paired fathead minnow (Pimephales promelas) reproductive test.

Part 1: Assessing biological effects of final bleached kraft pulp mill effluent using a mobile bioassay trailer system
Abstract Reproductive effects have been recorded in wild fish in waters receiving pulp mill effluent (PME) since the mid to late 1980s. Laboratory assays with fathead minnow (FHM; Pimephales promelas) have been developed to better understand fish responses to PME. However, observations from laboratory studies have been variable, making it difficult to establish cause/effect relationships. A lack of environmental relevance in these laboratory studies may have contributed to the variability observed. The objectives of the present study were, first, to determine the effects of bleached kraft PME (BKME) on FHM under environmentally realistic conditions (i.e., ambient water and effluent quality) and, second, to determine the suitability of pair-breeding FHM to better link BKME-induced changes in indicators at the biochemical, individual, and population levels. A mobile bioassay trailer was situated on-site at a bleached kraft mill for 60 d, allowing supply of both ambient water (Lake Superior, Canada) and final BKME. The reproductive output of FHM was initially assessed for 21 d to obtain baseline data pre-exposure. At the end of the pre-exposure period, selected breeding pairs were exposed to final BKME (100% v/v and 1% v/v) for 21 d. Results demonstrated a stimulatory response pattern at 1% BKME (e.g., increased egg production) compared to control. In the 100% treatment, spawning events were reduced and fewer eggs were produced during the first two weeks of exposure. Exposure to 100% (v/v) BKME also resulted in ovipositor development in males and development of male secondary sex characteristics in females. Obtaining pre-exposure data and use of pair-breeding FHM in this assay gave a sensitive indication of effluent effects and allowed accurate comparisons of endpoints to be made. [source]

Surgery for disc-associated wobbler syndrome in the dog , an examination of the controversy

N. D. Jefferyq
Controversy surrounds treatment of disc-associated ,wobbler' syndrome in the dog, centring on the choice of method of surgical decompression used. In this review, details of previously published case series are summarised and critically examined in an attempt to compare success rates and complications of different types of surgery. Unequivocally accurate comparisons were difficult because of differences in methods of case recording between series. Short-term success rates were high (approximately 80 per cent), but there was a high rate of recurrence (around 20 per cent) after any surgical treatment, suggesting the possibility that the syndrome should be considered a multifocal disease of the caudal cervical region. Statistical analysis revealed no significant differences in success rates between the various reported decompressive surgical techniques [source]

Issues in designing and interpreting clinical trials of treatments for chronic hepatitis C

C. O'Brien
Summary., Many of the major advances in treating patients for chronic hepatitis C have been made based on the results of randomized, double-blind, controlled clinical trials. However, given the large number of hepatitis C medications in development, physicians need to understand the unique elements and types of clinical trials in order to make accurate comparisons of differing drug efficacy claims. Clinicians also need to be aware of the various factors that can influence the outcomes and interpretations of these trials, irrespective of the intervention under study. For example, similar trials conducted in the United States and Europe may have different outcomes simply because the study populations differ. Thus, both trial design and patient population are important considerations in the design and analysis of clinical trials for patients with chronic hepatitis C. [source]