Ultrasonic tomographic imaging of defects in industrial materials

Ultrasonic tomography has been fairly widely applied for imaging of inhomogeneities in isotropic materials, particularly in the medical field, however, little success has been made in its application to industrial materials. This is largely due to the complex nature of ultrasonic wave propagation in these anisotropic materials. The three dimensional characteristics of ultrasonic wave propagation in anisotropic materials have been thoroughly studied for single crystals and also studied recently for different composites [1,2,3]. Understanding these characteristics provides the theoretical background for developing appropriate ultrasonic tomographic imaging methods for industrial materials

Esterase-D and chromosome patterns in Central Amazon piranha (Serrasalmus rhombeus Linnaeus, 1766) from Lake Catalão

This study presents additional genetic data on piranha (Serrasalmus rhombeus Linnaeus, 1766) complex previously diagnosed due to the presence of distinct cytotypes 2n = 58 and 2n = 60. Three esterase-D enzyme loci (Est-D1, Est-D2 and Est-D3) were examined and complemented with chromosomal data from 66 piranha specimens collected from Lake Catalão. For all specimens the Est-D1 and Est-D2 loci were monomorphic. In contrast, the Est-D3 locus was polymorphic with genotypes and alleles being differentially distributed in the previously described cytotypes and served as the basis for detecting a new cytotype (2n = 60 B). In cytotype 2n = 58 the Est-D3 locus was also polymorphic and presented Mendelian allelic segregation with four genotypes (Est-D311, Est-D312, Est-D322 and Est-D333) out of six theoretically possible genotypes, presumably encoded by alleles Est-D31 (frequency = 0.237), EsT-D32 (0.710) and Est-D33 (0.053). A Chi-squared (χ2) test for Hardy-Weinberg equilibrium was applied to the Est-D3locus and revealed a genetic unbalance in cytotype 2n = 58, indicating the probable existence in the surveyed area of different stocks for that karyotypic structure. A silent null allele (Est-D30 with a high frequency (0.959) occurred exclusively in the 2n = 60 cytotype. On the other hand, the new cytotype 2n = 60 B described here for the first time was monomorphic for the presumably fixed Est-D33 allele. The data as a whole should contribute to the better understanding the rhombeus complex taxonomic status definitíon in the Central Amazon. © 2006 Sociedade Brasileira de Genética

Outcomes research in the development and evaluation of practice guidelines

BACKGROUND: Practice guidelines have been developed in response to the observation that variations exist in clinical medicine that are not related to variations in the clinical presentation and severity of the disease. Despite their widespread use, however, practice guideline evaluation lacks a rigorous scientific methodology to support its development and application. DISCUSSION: Firstly, we review the major epidemiological foundations of practice guideline development. Secondly, we propose a chronic disease epidemiological model in which practice patterns are viewed as the exposure and outcomes of interest such as quality or cost are viewed as the disease. Sources of selection, information, confounding and temporal trend bias are identified and discussed. SUMMARY: The proposed methodological framework for outcomes research to evaluate practice guidelines reflects the selection, information and confounding biases inherent in its observational nature which must be accounted for in both the design and the analysis phases of any outcomes research study

The Impact of Severe Acute Respiratory Syndrome on Otorhinolaryngological Services at the Prince of Wales Hospital in Hong Kong

Objectives/Hypothesis: The objective was to describe the impact of severe acute respiratory syndrome (SARS) on the services of the division of otorhinolaryngology-head and neck surgery at an academic tertiary referral hospital in Hong Kong. Study Design: Descriptive. Methods: Records of general and subspecialty outpatient attendance, ward admissions, ward bed occupancy, and elective and emergency surgery were obtained for the period since the SARS outbreak and for an equivalent period before the outbreak. The changes in these parameters were determined against the background of new SARS cases. Results: Since the outbreak of SARS in March 2003, the weekly outpatient clinic attendance has declined by 59%, the number of operations performed by 79%, the average ward bed occupancy rate by 79% and the daily admission rate by 84%. A dramatic increase of 300% in the number of patients defaulting on their outpatient appointments was recorded. Conclusion: The substantial decrease in otorhinolaryngological services at an academic tertiary referral hospital in Hong Kong has been multifaceted. The decrease in attendance at the outpatient clinics reflects the increased number of patients defaulting on their appointments. Nonessential elective surgery was suspended soon after the outbreak, accounting for the decrease in the number of surgical procedures performed and partially for the decrease in ward bed occupancy and ward admissions. The temporary closure of the accident and emergency department contributed to the decrease in ward admissions and emergency surgical procedures. The reduced service offered by the hospital is having an impact on the quality of care available to patients with non-life-threatening otorhinolaryngological conditions.link_to_subscribed_fulltex