Cryptosporidium Outbreak (Water Treatment Failure): North Battleford, Saskatchewan, Spring 2001

An outbreak of cryptosporidiosis occurred in the town of North Battleford, Saskatchewan, Canada in the spring of 2001. The outbreak left thousands of people sick including about 50 people hospitalized. The source of the outbreak was from the city\u27s surface water treatment plant. The Sedimentation Contact Unit did not satisfactorily remove suspended solids from the source water, resulting in filter breakthrough. Contaminated water was released into the distribution system causing the outbreak. Communication breakdown and confusion exacerbated the situation, extending the duration of the outbreak. The outbreak prompted the province to change the way it regulated municipal utilities of water and wastewater

Distress in relation to attenuated psychotic symptoms in the ultra-high-risk population is not associated with increased risk of psychotic disorder.

AIM: The \u27ultra-high-risk\u27 criteria identify a clinical population at substantially increased risk for progressing to schizophrenia and other psychotic disorders. Although a number of clinical variables predictive of transition to psychotic disorder have been identified within this population, the predictive value of the level of distress associated with attenuated psychotic symptoms has not yet been examined. This was the aim of the present study. METHOD: The level of distress (0-100) associated with attenuated psychotic symptoms was recorded for 70 ultra-high-risk (UHR) patients using the Comprehensive Assessment of At-Risk Mental State (CAARMS). Transition to psychosis was assessed over a 16-month follow-up period. RESULTS: Of the 70 UHR patients, 15 transitioned to psychosis (21.4%). Of the four CAARMS subscales measuring attenuated positive symptoms, Perceptual Abnormalities was rated as the most distressing. There were no differences in CAARMS scales rated as the most distressing between those who transitioned to psychosis and those who did not. There was also no association between higher levels of distress associated with attenuated psychotic symptoms and transition to psychosis. CONCLUSION: Although the findings require replication, they indicate that the degree of distress associated with attenuated psychotic symptoms should not be used as a criterion for enriching UHR samples for risk of frank psychotic disorder

Coronavirus Genomics and Bioinformatics Analysis

The drastic increase in the number of coronaviruses discovered and coronavirus genomes being sequenced have given us an unprecedented opportunity to perform genomics and bioinformatics analysis on this family of viruses. Coronaviruses possess the largest genomes (26.4 to 31.7 kb) among all known RNA viruses, with G + C contents varying from 32% to 43%. Variable numbers of small ORFs are present between the various conserved genes (ORF1ab, spike, envelope, membrane and nucleocapsid) and downstream to nucleocapsid gene in different coronavirus lineages. Phylogenetically, three genera, Alphacoronavirus, Betacoronavirus and Gammacoronavirus, with Betacoronavirus consisting of subgroups A, B, C and D, exist. A fourth genus, Deltacoronavirus, which includes bulbul coronavirus HKU11, thrush coronavirus HKU12 and munia coronavirus HKU13, is emerging. Molecular clock analysis using various gene loci revealed that the time of most recent common ancestor of human/civet SARS related coronavirus to be 1999–2002, with estimated substitution rate of 4×10−4 to 2×10−2 substitutions per site per year. Recombination in coronaviruses was most notable between different strains of murine hepatitis virus (MHV), between different strains of infectious bronchitis virus, between MHV and bovine coronavirus, between feline coronavirus (FCoV) type I and canine coronavirus generating FCoV type II, and between the three genotypes of human coronavirus HKU1 (HCoV-HKU1). Codon usage bias in coronaviruses were observed, with HCoV-HKU1 showing the most extreme bias, and cytosine deamination and selection of CpG suppressed clones are the two major independent biological forces that shape such codon usage bias in coronaviruses

CoVDB: a comprehensive database for comparative analysis of coronavirus genes and genomes

The recent SARS epidemic has boosted interest in the discovery of novel human and animal coronaviruses. By July 2007, more than 3000 coronavirus sequence records, including 264 complete genomes, are available in GenBank. The number of coronavirus species with complete genomes available has increased from 9 in 2003 to 25 in 2007, of which six, including coronavirus HKU1, bat SARS coronavirus, group 1 bat coronavirus HKU2, groups 2c and 2d coronaviruses, were sequenced by our laboratory. To overcome the problems we encountered in the existing databases during comparative sequence analysis, we built a comprehensive database, CoVDB (http://covdb.microbiology.hku.hk), of annotated coronavirus genes and genomes. CoVDB provides a convenient platform for rapid and accurate batch sequence retrieval, the cornerstone and bottleneck for comparative gene or genome analysis. Sequences can be directly downloaded from the website in FASTA format. CoVDB also provides detailed annotation of all coronavirus sequences using a standardized nomenclature system, and overcomes the problems of duplicated and identical sequences in other databases. For complete genomes, a single representative sequence for each species is available for comparative analysis such as phylogenetic studies. With the annotated sequences in CoVDB, more specific blast search results can be generated for efficient downstream analysis

The 'At-risk mental state' for psychosis in adolescents : clinical presentation, transition and remission.

Despite increased efforts over the last decade to prospectively identify individuals at ultra-high risk of developing a psychotic illness, limited attention has been specifically directed towards adolescent populations (<18 years). In order to evaluate how those under 18 fulfilling the operationalised criteria for an At-Risk Mental State (ARMS) present and fare over time, we conducted an observational study. Participants (N = 30) generally reported a high degree of functional disability and frequent and distressing perceptual disturbance, mainly in the form of auditory hallucinations. Seventy percent (21/30) were found to fulfil the criteria for a co-morbid ICD-10 listed mental health disorder, with mood (affective; 13/30) disorders being most prevalent. Overall transition rates to psychosis were low at 24 months follow-up (2/28; 7.1 %) whilst many participants demonstrated a significant reduction in psychotic-like symptoms. The generalisation of these findings may be limited due to the small sample size and require replication in a larger sample

Cloud condensation nucleus spectrometer

A cloud condensation nucleus spectrometer having a streamwise segmented condensation nucleus growth column. The condensation nucleus growth column includes alternating hot and cold temperature-maintaining segments arranged next to one another. The temperature difference between adjacent hot and cold temperature-maintaining segments increases from the input opening to an output opening of the condensation nucleus growth column to produce a supersaturation distribution that increases from the input opening to the output opening

Biomechanical techniques to evaluate tibial rotation: a systematic review

Purpose: This article systematically reviewed the biomechanical techniques to quantify tibial rotation, for an overview of how to choose a suitable technique for specific clinical application. Methods: A systematic search was conducted and finally 110 articles were included in this study. The articles were categorized by the conditions of how the knee was examined: external load application, physical examination and dynamic task. Results: The results showed that two-thirds of the included studies measured tibial rotation under external load application, of which over 80% of the experiments employed a cadaveric model. The common techniques used included direct displacement measurement, motion sensor, optical tracking system and universal force moment sensor. Intra-operative navigation system was used to document tibial rotation when the knee was examined by clinical tests. For dynamic assessment of knee rotational stability, motion analysis with skin reflective markers was frequently used although this technique is less accurate due to the skin movement when compared with radiographic measurement. Conclusion: This study reports various biomechanical measurement techniques to quantify tibial rotation in the literatures. To choose a suitable measurement technique for a specific clinical application, it is suggested to quantify the effectiveness of a new designed surgical technique by using a cadaveric model before applying to living human subjects for intra-operative evaluation or long-time functional stability assessment. Attention should also be paid on the study's purpose, whether to employ a cadaveric model and the way of stress applied to the knee. Level of evidence: IV