Statistical estimation of the precision of clinico-laboratory measurements

Traditionally, the term "precision" denotes the quality of work, uniting the correctness and reproducibility of results. However, it can have another sense: the minimal difference between the specimens, detectable by this or that device or method. In order to rule out misunderstanding, we propose to use the term "measuring precision", if the term is used in its second meaning. It is easy to assess the measuring precision by statistical processing of large scope of data: if the histogram shows waves which disappear after the histogram step is increased, this means that the device and method used in this study permit biochemical analysis only at measuring precision corresponding to the histogram step at which the waves disappear. A table of measuring precision values is offered for 19 methods realized using the Labsystems FP-900 device (Finland) In many cases it is obviously low.     

HLA-DRB1 genes and disease severity in rheumatoid arthritis. The MIRA Trial Group. Minocycline in Rheumatoid Arthritis

OBJECTIVE: To examine the effect of alleles encoding the "shared"/"rheumatoid" epitope on rheumatoid arthritis (RA) disease severity in patients who participated in the minocycline in RA (MIRA) trial. METHODS: Of 205 patients with a week-48 visit, blood was available for typing of HLA-DRB1 and HLA-DQB1 in 174 (85%) and successfully completed in 169 (82%). Baseline erosions were used to assess disease severity and new erosions at the last visit served as a proxy for progression. RESULTS: At baseline, there was no association between the presence of erosive disease or rheumatoid factor status and the dose of rheumatoid epitope (homozygous, heterozygous, none) or the specific alleles identified. At the final visit, a gradient was observed for the 3 allelic subgroups (and their gene doses) in the occurrence of new erosions among the Caucasian placebo-treated, but not the minocycline-treated, patients. A treatment group/HLA-DR4 epitope interaction was demonstrated in multivariate analyses. Approximately two-thirds of African-American patients did not have the rheumatoid epitope. CONCLUSION: HLA-DRB1 oligotyping may be useful in predicting the progression of disease in some Caucasian patients. Our study corroborates the infrequency of the epitope among African-American patients with RA.     

Frequency analysis of river water quality using integrated urban wastewater models

In recent years integrated models have been developed to simulate the entire urban wastewater system, including urban drainage systems, wastewater treatment plants, and receiving waterbodies. This paper uses such an integrated urban wastewater model to analyze the frequency of receiving water quality in an urban wastewater system with the aim of assessing the overall system performance during rainfall events. The receiving water quality is represented by two indicators: event mean dissolved oxygen (DO) concentration and event mean ammonium concentration. The compliance probability of the water quality indicators satisfying a specific threshold is used to represent the system performance, and is derived using the rainfall events from a series of 10 years' rainfall data. A strong correlation between the depth of each rainfall event and the associated volume of combined sewer overflow (CSO) discharges is revealed for the case study catchment, while there is a low correlation between the intensity/duration of the rainfall event and the volume of the CSO discharges. The frequency analysis results obtained suggest that the event mean DO and ammonium concentrations have very different characteristics in terms of compliance probabilities at two discharging points for CSO and wastewater treatment plant effluent, respectively. In general, the simulation results provide an understanding of the performance of the integrated urban wastewater system and can provide useful information to support water quality management.     

Sustainable Disposal of Domestic Sanitary Waste

The study presented is an example of the assessment of the relative sustainability of either option for disposal of domestic sanitary waste, either via the toilet or via the solid waste route. This required an evaluation of the total (social, economic, environmental, and technical) benefit/cost of implementing and adopting the alternative routes and an assessment of public responsiveness to encouragement to change sanitary waste disposal practices. It illustrates how, even for an apparently straightforward either/or question, the assessment of relative sustainability is complex and the amount of data needed to quantify sustainability indicators is prodigious. The study also provides an appraisal of the effectiveness of public campaigns to reduce waterborne disposal. Important information regarding public attitude and behavior in relation to wastewater systems has been acquired and lessons for ways of encouraging behavioral change to more sustainable ways of living have been gleaned.     

Formal verification of conflict detection algorithms

Safety assessment of new air traffic management systems is a main issue for civil aviation authorities. Standard techniques such as testing and simulation have serious limitations in new systems that are significantly more autonomous than the older ones. In this paper, we present an innovative approach for establishing the correctness of conflict detection systems. Fundamental to our approach is the concept of trajectory, and how we represent a continuous physical trajectory by a continuous path in the x-y plane constrained by physical laws and operational requirements. From the model of trajectories, we extract, and formally prove, high-level properties that can serve as a framework to analyze conflict scenarios. We use the AILS (Airborne Information for Lateral Spacing) alerting algorithm as a case study of our approach. Published online: 19 November 2002     

Controlling Salmonella infections in pig farms: A framework modelling approach

Human salmonellosis is an important food-borne disease and S. Typhimurium is the most common serotype attributed to pork products. Under a farm-to-fork strategy, reducing the levels of Salmonella-positive pigs entering the slaughterhouse is an important goal. A framework model was developed, where the effect of dynamic (infection characteristics) and non-dynamic (cleanness and disinfection, biosecurity measures, etc.) factors were considered. Four baseline scenarios were created, corresponding to different levels associated with national Salmonella monitoring programs, and sensitivity analyses were run for the non-dynamic factors. Moreover, the option of vaccination was incorporated into the model, in order to provide with a tool for the formulation of an optimum vaccination strategy depending on the characteristics of the vaccine.     

Human Response to Emergency Communication: A Review of Guidance on Alerts and Warning Messages for Emergencies in Buildings

The purpose of this article is to provide guidance on enhancing human response to emergency communication. This guidance can, in turn, help engineers improve the design of emergency notification and messaging systems, which, as a result, can help inform occupant response, reduce occupant evacuation time, and increase occupant safety. The article begins with a literature review on how people respond to emergencies. The Protective Action Decision Model, which describes the decision-making process that precedes human response in disaster events, is used as a framework for the literature collected as part of this review. This model is divided into three pre-decisional and five decisional processes. The method used to create the guidance document is then explained, including the six steps taken to review the literature collected (from 162 engineering and social science sources), generate findings from this literature, and compile the key statements found in the guidance document. Guidance on alerts, visual/audible warnings and dissemination of warning messages are provided. These are organized according to alert/warning type and dissemination method. The findings of the literature review include five guidance statements on alerts, 16 guidance statements on visual warnings, seven guidance statements on audible warnings and eight guidance statements on the dissemination of warning messages. Finally, guidance on emergency message testing, including language, readability and fire drills as a means of response testing, is provided. It is envisioned that this guidance will inform practitioners on the design of future emergency communications and subsequently enhances evacuee performance through a better understanding of the manner in which emergency information is processed and the tools available to provide such information.