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1.  Tracking Socioeconomic Vulnerability Using Network Analysis: Insights from an Avian Influenza Outbreak in an Ostrich Production Network 
PLoS ONE  2014;9(1):e86973.
The focus of management in many complex systems is shifting towards facilitation, adaptation, building resilience, and reducing vulnerability. Resilience management requires the development and application of general heuristics and methods for tracking changes in both resilience and vulnerability. We explored the emergence of vulnerability in the South African domestic ostrich industry, an animal production system which typically involves 3–4 movements of each bird during its lifetime. This system has experienced several disease outbreaks, and the aim of this study was to investigate whether these movements have contributed to the vulnerability of this system to large disease outbreaks.
Methodology/Principal Findings
The ostrich production system requires numerous movements of birds between different farm types associated with growth (i.e. Hatchery to juvenile rearing farm to adult rearing farm). We used 5 years of movement records between 2005 and 2011 prior to an outbreak of Highly Pathogenic Avian Influenza (H5N2). These data were analyzed using a network analysis in which the farms were represented as nodes and the movements of birds as links. We tested the hypothesis that increasing economic efficiency in the domestic ostrich industry in South Africa made the system more vulnerable to outbreak of Highly Pathogenic Avian Influenza (H5N2). Our results indicated that as time progressed, the network became increasingly vulnerable to pathogen outbreaks. The farms that became infected during the outbreak displayed network qualities, such as significantly higher connectivity and centrality, which predisposed them to be more vulnerable to disease outbreak.
Taken in the context of previous research, our results provide strong support for the application of network analysis to track vulnerability, while also providing useful practical implications for system monitoring and management.
PMCID: PMC3909050  PMID: 24498004
2.  Chemometric Analysis for Identification of Botanical Raw Materials for Pharmaceutical Use: A Case Study Using Panax notoginseng 
PLoS ONE  2014;9(1):e87462.
The overall control of the quality of botanical drugs starts from the botanical raw material, continues through preparation of the botanical drug substance and culminates with the botanical drug product. Chromatographic and spectroscopic fingerprinting has been widely used as a tool for the quality control of herbal/botanical medicines. However, discussions are still on-going on whether a single technique provides adequate information to control the quality of botanical drugs. In this study, high performance liquid chromatography (HPLC), ultra performance liquid chromatography (UPLC), capillary electrophoresis (CE) and near infrared spectroscopy (NIR) were used to generate fingerprints of different plant parts of Panax notoginseng. The power of these chromatographic and spectroscopic techniques to evaluate the identity of botanical raw materials were further compared and investigated in light of the capability to distinguishing different parts of Panax notoginseng. Principal component analysis (PCA) and clustering results showed that samples were classified better when UPLC- and HPLC-based fingerprints were employed, which suggested that UPLC- and HPLC-based fingerprinting are superior to CE- and NIR-based fingerprinting. The UPLC- and HPLC- based fingerprinting with PCA were able to correctly distinguish between samples sourced from rhizomes and main root. Using chemometrics and its ability to distinguish between different plant parts could be a powerful tool to help assure the identity and quality of the botanical raw materials and to support the safety and efficacy of the botanical drug products.
PMCID: PMC3909187  PMID: 24498109
3.  An observational study of the hand hygiene initiative: a comparison of preintervention and postintervention outcomes 
BMJ Open  2013;3(5):e003018.
To evaluate the impact of implementing a simple, user-friendly eLearning module on hand hygiene (HH) compliance and infection rates.
Preintervention and postintervention observational study.
All neonates admitted to the neonatal intensive care unit (NICU) over the study period were eligible for participation and were included in the analyses. A total of 3422 patients were admitted over a 36-month span (July 2009 to June 2012).
In the preintervention and postintervention periods (phases I and II), all healthcare providers were trained on HH practices using an eLearning module. The principles of the ‘4 moments of HH’ and definition of ‘baby space’ were incorporated using interactive tools. The intervention then extended into a long-term sustainability programme (phase III), including the requirement of an annual recertification of the module and introduction of posters and screensavers throughout the NICU.
Primary and secondary outcome measures
The primary outcome was HH compliance rates among healthcare providers in the three phases. The secondary outcome was healthcare-associated infection rates in the NICU.
HH compliance rates declined initially in phase II then improved in phase III with the addition of a long-term sustainability programme (76%, 67% and 76% in phases I, II and III, respectively (p<0.01). Infection rates showed an opposing, but concomitant trend in the overall population as well as in infants <1500 g and were 4%, 6% and 4% (p=0.02), and 11%, 21% and 16% (p<0.01), respectively, during the three phases.
Interventions to improve HH compliance are challenging to implement and sustain with the need for ongoing reinforcement and education.
PMCID: PMC3664348  PMID: 23793705
Healthcare-associated infection; Nosocomial infection; Baby space; Hand hygiene compliance
4.  Outbreak of Extended-Spectrum β-Lactamase–producing Klebsiella oxytoca Infections Associated with Contaminated Handwashing Sinks1 
Emerging Infectious Diseases  2012;18(8):1242-1247.
Sinks are a potential reservoir for environment-to-patient and patient-to-patient transmission.
Klebsiella oxytoca is primarily a health care–associated pathogen acquired from environmental sources. During October 2006–March 2011, a total of 66 patients in a hospital in Toronto, Ontario, Canada, acquired class A extended-spectrum β-lactamase–producing K. oxytoca with 1 of 2 related pulsed-field gel electrophoresis patterns. New cases continued to occur despite reinforcement of infection control practices, prevalence screening, and contact precautions for colonized/infected patients. Cultures from handwashing sinks in the intensive care unit yielded K. oxytoca with identical pulsed-field gel electrophoresis patterns to cultures from the clinical cases. No infections occurred after implementation of sink cleaning 3×/day, sink drain modifications, and an antimicrobial stewardship program. In contrast, a cluster of 4 patients infected with K. oxytoca in a geographically distant medical ward without contaminated sinks was contained with implementation of active screening and contact precautions. Sinks should be considered potential reservoirs for clusters of infection caused by K. oxytoca.
PMCID: PMC3414015  PMID: 22841005
Klebsiella oxytoca; outbreak; ICU; sink; extended-spectrum β-lactamase; ESBL; antimicrobial resistance; handwashing; bacteria
5.  Melanin-Based Coatings as Lead-Binding Agents 
Interactions between metal ions and different forms of melanin play significant roles in melanin biochemistry. The binding properties of natural melanin and related synthetic materials can be exploited for nonbiological applications, potentially including water purification. A method for investigating metal ion-melanin interactions on solid support is described, with lead as the initial target. 2.5 cm discs of the hydrophobic polymer PVDF were coated with synthetic eumelanin from the tyrosinase-catalyzed polymerization of L-dopa, and with melanin extracted from human hair. Lead (Pb2+) binding was quantified by atomic absorption spectroscopy (flame mode), and the data was well fit by the Langmuir model. Langmuir affinities ranged from 3.4 · 103 to 2.2 · 104 M−1. At the maximum capacity observed, the synthetic eumelanin coating bound ~9% of its mass in lead. Binding of copper (Cu2+), zinc (Zn2+), and cadmium (Cd2+) to the synthetic-eumelanin-coated discs was also investigated. Under the conditions tested, the Langmuir affinities for Zn2+, Cd2+, and Cu2+ were 35%, 53%, and 77%, respectively, of the Langmuir affinity for Pb2+. The synthetic-eumelanin-coated discs have a slightly higher capacity for Cu2+ on a per mole basis than for Pb2+, and lower capacities for Cd2+ and Zn2+. The system described can be used to address biological questions and potentially be applied toward melanin-based water purification.
PMCID: PMC3350951  PMID: 22611345

Results 1-5 (5)