60 research outputs found
Quantum error correction for continuously detected errors with any number of error channels per qubit
It was shown by Ahn, Wiseman, and Milburn [PRA {\bf 67}, 052310 (2003)] that
feedback control could be used as a quantum error correction process for errors
induced by weak continuous measurement, given one perfectly measured error
channel per qubit. Here we point out that this method can be easily extended to
an arbitrary number of error channels per qubit. We show that the feedback
protocols generated by our method encode logical qubits in physical
qubits, thus requiring just one more physical qubit than in the previous case.Comment: 4 page
Laboratory-acquired infections of Salmonella enterica serotype Typhi in South Africa: phenotypic and genotypic analysis of isolates
BACKGROUND: Workers in clinical microbiology laboratories are exposed to a variety of pathogenic microorganisms. Salmonella species is among the most commonly reported bacterial causes of laboratory-acquired infections. We report on three cases of laboratory-acquired Salmonella enterica serotype Typhi (Salmonella Typhi) infection which occurred over the period 2012 to 2016 in South Africa. METHODS: Laboratory investigation included phenotypic and genotypic characterization of isolates. Phenotypic analysis included standard microbiological identification techniques, serotyping and antimicrobial susceptibility testing. Genotypic analysis included the molecular subtyping methodologies of pulsed-field gel electrophoresis analysis, multilocus sequence typing and whole-genome sequencing (WGS); with WGS data analysis including phylogenetic analysis based upon comparison of single nucleotide polymorphism profiles of isolates. RESULTS: All cases of laboratory-acquired infection were most likely the result of lapses in good laboratory practice and laboratory safety. The following critical issues were highlighted. There was misdiagnosis and misreporting of Salmonella Typhi as nontyphoidal Salmonella by a diagnostic laboratory, with associated public health implications. We highlight issues concerning the importance of accurate fluoroquinolone susceptibility testing and interpretation of results according to updated guidelines. We describe potential shortcomings of a single disk susceptibility screening test for fluoroquinolone susceptibility and suggest that confirmatory minimum inhibitory concentration testing should always be performed in cases of invasive Salmonella infections. These antimicrobial susceptibility testing issues resulted in inappropriate ciprofloxacin therapy which may have been responsible for failure in clearance of pathogen from patients. Salmonella Typhi capsular polysaccharide vaccine was not protective in one case, possibly secondarily to a faulty vaccine. CONCLUSIONS: Molecular subtyping of isolates proved effective to investigate the genetic relatedness of isolates. Molecular subtyping data interpreted together with epidemiological data allowed us to pinpoint the most likely sources for our cases of laboratory-acquired infection
An outbreak of lymphocutaneous sporotrichosis among mine-workers in South Africa
BACKGROUND
The largest outbreak of sporotrichosis occurred between 1938 and 1947 in the gold mines
of Witwatersrand in South Africa. Here, we describe an outbreak of lymphocutaneous sporotrichosis
that was investigated in a South African gold mine in 2011.
METHODOLOGY
Employees working at a reopened section of the mine were recruited for a descriptive
cross-sectional study. Informed consent was sought for interview, clinical examination and
medical record review. Specimens were collected from participants with active or partiallyhealed
lymphocutaneous lesions. Environmental samples were collected from underground
mine levels. Sporothrix isolates were identified by sequencing of the internal transcribed
spacer region of the ribosomal gene and the nuclear calmodulin gene.
PRINCIPAL FINDINGS
Of 87 male miners, 81 (93%) were interviewed and examined, of whom 29 (36%) had skin
lesions; specimens were collected from 17 (59%). Sporotrichosis was laboratory-confirmed
among 10 patients and seven had clinically-compatible lesions. Of 42miners with known HIV
status, 11 (26%) were HIV-infected. No cases of disseminated disease were detected. Participants
with 3 yearsâ mining experience had a four times greater odds of developing sporotrichosis
than those who had been employed for >3 years (adjusted OR 4.0, 95%CI 1.2â13.1). Isolates from 8 patients were identified as Sporothrix schenckii sensu stricto by calmodulin
gene sequencing while environmental isolates were identified as Sporothrix mexicana.
CONCLUSIONS/SIGNIFICANCE
S. schenckii sensu stricto was identified as the causative pathogen. Although genetically
distinct species were isolated from clinical and environmental sources, it is likely that the source was contaminated soil and untreated wood underground. No cases occurred following
recommendations to close sections of the mine, treat timber and encourage consistent
use of personal protective equipment. Sporotrichosis is a potentially re-emerging disease
where traditional, rather than heavily mechanised, mining techniques are used. Surveillance
should be instituted at sentinel locations.http://www.plosntds.orgam201
Basic student nurse perceptions about clinical instructor caring
Abstract: Background: Caring is the core of nursing and should be cultivated in student nurses. However, there are serious concerns about the caring concern in the clinical environment and in nursing education. Clinical instructors are ideally positioned to care for student nurses so that they in turn, can learn to care for their patients. Methods: A descriptive, comparative, cross-sectional and correlational quantitative research design with convenience sampling was conducted to describe the perceptions of junior student nurses (n Œ 148) and senior student nurses (n Œ 168) regarding clinical instructor caring. A structured self administered questionnaire using the Nursing Student Perceptions of Instructor Caring (NSPIC) (Wade & Kasper, 2006) was used. Descriptive statistics and hypotheses testing using parametric and non parametric methods were conducted. The reliability of the NSPIC was determined..
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Tumor Lysis, Adverse Events, and Dose Adjustments in 297 Venetoclax-Treated CLL Patients in Routine Clinical Practice.
PURPOSE: Clinical trials of venetoclax reported negligible rates of clinical tumor lysis syndrome (TLS) in patients with chronic lymphocytic leukemia (CLL) when using an extended dose escalation schedule. We aimed to understand TLS prophylaxis, rates of select adverse events (AE), and impact of dosing modifications in routine clinical practice. EXPERIMENTAL DESIGN: This retrospective cohort study included 297 CLL venetoclax-treated patients outside of clinical trials in academic and community centers. Demographics, baseline disease characteristics, venetoclax dosing, TLS risk and prophylaxis, and AEs were collected. RESULTS: The group was 69% male, 96% had relapsed/refractory CLL, 45% had deletion chromosome 17p, 84% had unmutated IGHV, 80% received venetoclax monotherapy, and median age was 67. TLS risk was categorized as low (40%), intermediate (32%), or high (28%), and 62% had imaging prior to venetoclax initiation. Clinical TLS occurred in 2.7% of patients and laboratory TLS occurred in 5.7%. Pre-venetoclax TLS risk group and creatinine clearance independently predict TLS development in multivariable analysis. Grade 3/4 AEs included neutropenia (39.6%), thrombocytopenia (29.2%), infection (25%), neutropenic fever (7.9%), and diarrhea (6.9%). Twenty-two patients (7.4%) discontinued venetoclax due to an AE. Progression-free survival was similar regardless of number of dose interruptions, length of dose interruption, and stable venetoclax dose. CONCLUSIONS: These data provide insights into current use of venetoclax in clinical practice, including TLS rates observed in clinical practice. We identified opportunities for improved adherence to TLS risk stratification and prophylaxis, which may improve safety
Epidemiologic Investigations into Outbreaks of Rift Valley Fever in Humans, South Africa, 2008â2011
Rift Valley fever (RVF) is an emerging zoonosis posing a public health threat to humans in Africa. During sporadic RVF outbreaks in 2008â2009 and widespread epidemics in 2010â2011, 302 laboratory-confirmed human infections, including 25 deaths (case-fatality rate, 8%) were identified. Incidence peaked in late summer to early autumn each year, which coincided with incidence rate patterns in livestock. Most case-patients were adults (median age 43 years), men (262; 87%), who worked in farming, animal health or meat-related industries (83%). Most case-patients reported direct contact with animal tissues, blood, or other body fluids before onset of illness (89%); mosquitoes likely played a limited role in transmission of disease to humans. Close partnership with animal health and agriculture sectors allowed early recognition of human cases and appropriate preventive health messaging
Common Genetic Polymorphisms Influence Blood Biomarker Measurements in COPD
Implementing precision medicine for complex diseases such as chronic obstructive lung disease (COPD) will require extensive use of biomarkers and an in-depth understanding of how genetic, epigenetic, and environmental variations contribute to phenotypic diversity and disease progression. A meta-analysis from two large cohorts of current and former smokers with and without COPD [SPIROMICS (N = 750); COPDGene (N = 590)] was used to identify single nucleotide polymorphisms (SNPs) associated with measurement of 88 blood proteins (protein quantitative trait loci; pQTLs). PQTLs consistently replicated between the two cohorts. Features of pQTLs were compared to previously reported expression QTLs (eQTLs). Inference of causal relations of pQTL genotypes, biomarker measurements, and four clinical COPD phenotypes (airflow obstruction, emphysema, exacerbation history, and chronic bronchitis) were explored using conditional independence tests. We identified 527 highly significant (p 10% of measured variation in 13 protein biomarkers, with a single SNP (rs7041; p = 10â392) explaining 71%-75% of the measured variation in vitamin D binding protein (gene = GC). Some of these pQTLs [e.g., pQTLs for VDBP, sRAGE (gene = AGER), surfactant protein D (gene = SFTPD), and TNFRSF10C] have been previously associated with COPD phenotypes. Most pQTLs were local (cis), but distant (trans) pQTL SNPs in the ABO blood group locus were the top pQTL SNPs for five proteins. The inclusion of pQTL SNPs improved the clinical predictive value for the established association of sRAGE and emphysema, and the explanation of variance (R2) for emphysema improved from 0.3 to 0.4 when the pQTL SNP was included in the model along with clinical covariates. Causal modeling provided insight into specific pQTL-disease relationships for airflow obstruction and emphysema. In conclusion, given the frequency of highly significant local pQTLs, the large amount of variance potentially explained by pQTL, and the differences observed between pQTLs and eQTLs SNPs, we recommend that protein biomarker-disease association studies take into account the potential effect of common local SNPs and that pQTLs be integrated along with eQTLs to uncover disease mechanisms. Large-scale blood biomarker studies would also benefit from close attention to the ABO blood group
Risk factors for Coronavirus disease 2019 (Covid-19) death in a population cohort study from the Western Cape province, South Africa
Risk factors for coronavirus disease 2019 (COVID-19) death in sub-Saharan Africa and the effects of human immunodeficiency virus (HIV) and tuberculosis on COVID-19 outcomes are unknown. We conducted a population cohort study using linked data from adults attending public-sector health facilities in the
Western Cape, South Africa. We used Cox proportional hazards models, adjusted for age, sex, location, and comorbidities, to examine the associations between HIV, tuberculosis, and COVID-19 death from 1 March to 9 June 2020 among (1) public-sector âactive patientsâ (â„1 visit in the 3 years before March 2020); (2) laboratory-diagnosed COVID-19 cases; and (3) hospitalized COVID-19
cases. We calculated the standardized mortality ratio (SMR) for COVID-19, comparing adults living with and without HIV using
modeled population estimates.Among 3 460 932 patients (16% living with HIV), 22 308 were diagnosed with COVID-19, of whom 625 died. COVID19 death was associated with male sex, increasing age, diabetes, hypertension, and chronic kidney disease. HIV was associated with
COVID-19 mortality (adjusted hazard ratio [aHR], 2.14; 95% confidence interval [CI], 1.70â2.70), with similar risks across strata of
viral loads and immunosuppression. Current and previous diagnoses of tuberculosis were associated with COVID-19 death (aHR,
2.70 [95% CI, 1.81â4.04] and 1.51 [95% CI, 1.18â1.93], respectively). The SMR for COVID-19 death associated with HIV was 2.39
(95% CI, 1.96â2.86); population attributable fraction 8.5% (95% CI, 6.1â11.1)
The role of leadership in the management of change
M.Com. (Business Management)"In the three short decades between now and the twenty first century, millions of ordinary, psychologically normal people will face an abrupt collision with the future. Citizens of the world's richest and most technically advanced nations, many of them, will find it increasingly painful to keep up with incessant demand for change that characterises our time." (Toftler, 1983:18.) More than ajlecade and a half has passed since Alvin Toffler wrote his best seller, Future Shock. The year 2000 is less than 10 years away. Future shock is something each of us lives with every day. Things change around us constantly - from there the saying: "the only constant in life is change". As individuals, our lives become more and more complicated. As managers, we face increasing pressure and uncertainty (Manning, 1987:1). One of the most important skills a manager can have in his of her repertoire these days is the skill to manage change (Burke et a/.,1991:87). Managers must manage today's business effectively while creating a new and radically different kind of business for tomorrow. It's a daunting task, but it's one that cannot be postponed - the future simply won't wait (Manning, 1987:1). Within the South African context great challenges face management. South Africa is faced with addressing major political, economic and social imbalances. Traditionally, the business community has often been reluctant to play an upfront role in the political realm. The business of business is business, was a commonly heard adage. In 1988, the formation of the Consultative Business Movement was a small sign that business was starting to take seriously it's role in a changing society (Eloff, 1992:12)
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