Selective Migration and Health

We investigate the proposition that the health of migrants does not constitute a random sample of the health of the sending region using data from the Panel Study of Income Dynamics on internal migration within the United States. Panel data is crucial, as it enables us to observe geographic mobility as well as the health of the migrant prior to migration. We find that, for men and women below 60 years of age, a move from the middle to the bottom of the health distribution reduces mobility by 32-40% and 12-18%, respectively. Nonrandom attrition from the panel implies that these estimates are lower bounds. By contrast, we find evidence that, among older people, there is higher mobility at the top and bottom of the health distribution than there is at the middle. We consider two explanations for this: first that elderly persons may migrate to be closer to a family network once they fall ill, and second that non-random attrition may also be causing an upwards bias in the estimated effect of illness on mobility.Migration, Health, Selection, Attrition

Determinants of Success in High School Economics: Lessons from the Field

Recently, the Hawaii Council on Economic Education conducted a survey of high school seniors to gauge their understanding of basic economic concepts. Based on these results, we conduct a series of case studies, consisting of interviews with principals and economics teachers at eight Hawaii public high schools. We summarize the qualitative and quantitative results of these interviews. We then use these and other data to estimate the effects of school, demographic, and other characteristics on average student achievement on the survey. We find that the improvement in student test scores as a result of a one semester economics course is modest, but that the single greatest determinant of achievement is overall school quality. Based on these and other findings, we present recommendations for policy and further research.

A quantitative evaluation of three hand drying methods and the potential for dissemination of virus particles into the environment

The importance of hand hygiene in reducing the spread of pathogens has been long established and this has been highlighted recently in initiatives such as the NHS’s ‘clean your hands’ campaign. However, much of the focus on hand hygiene has concerned effective hand washing; there has been less emphasis on hand drying and its role in hygienic practices. This study aimed to compare three hand drying methods namely paper towels, a warm air dryer and a jet air dryer for their relative ability to disseminate virus particles into the washroom environment during hand drying. A bacteriophage model was used to compare these methods; hands were artificially contaminated with MS2 phage and dried using each device. Both air sampling and contact plates were assessed and a plaque assay was used to quantify virus dissemination. Samples were collected at set times, heights, angles and distances around each device. Both air sampling and contact plate results indicated that the jet air dryer produced significantly more virus dispersal than either paper towels or the warm air dryer in terms of quantity, distance travelled and the time spent circulating in the air around the device and potentially in the washroom environment

Cinnamaldehyde increases the susceptibility of quorum-sensing-mediated biofilms to conventional antibiotics

The role of bacterial communication, also known as quorum sensing is an important mechanism in biofilm formation which is fundamental to the development of anti-biofilm strategies. In this current study, the synergy between a quorum sensing inhibitor (cinnamaldehyde) and two antibiotics (ceftazidime and levofloxacin) was evaluated in an attempt to develop a strategy for biofilm disruption using the high-throughput minimum biofilm eliminating concentration (MBEC) assay. Klebsiella pneumoniae and Proteus mirabilis biofilms of initial broth suspensions of 108 colony forming units (CFU) per mL, cultivated on the pegs of the MBEC device were challenged with 5120 µg/ml of ceftazidime and levofloxacin in a double dilution assay in the presence of 500 µM cinnamaldehyde. The minimum inhibitory concentrations (MIC) in the presence of cinnamaldehyde for ceftazidime and levofloxacin were 0.125% (640 µg/mL) and 0.0625% (320 µg/mL) respectively with no significant bacterial growth on LB agar. The MBECs for ceftazidime and levofloxacin were above 5120 and 2560 µg/mL respectively which yielded over 70% reduction in both Klebsiella pneumoniae and Proteus mirabilis biofilms. The above results indicate the possibility that the synergy between antimicrobial agents may lead to biofilm eradication

The arrested success of microfinance institutions in Zambia

This paper investigates how legal and regulatory structures impact microfinance ownership and performance. It draws from the institutional story of Zambia which has experienced regulatory and legislative flux since drafting its first microfinance act in 2006. Based on interviews with key stakeholders in the Zambian microfinance industry, the paper highlights the negative effects of this act and the subsequent imposed interest rate cap. It finds that foreign rather than local ownership and not having historical roots in a not-for-profit model is advantageous for MFI survival in these turbulent institutional conditions. Therefore, it provides an important contribution to understanding the effects of regulatory failure in microfinance with theoretical as well as important practical implications

OUTCOMES-BASED CONTRACTS AND THE HIDDEN TURN TO PUBLIC VALUE MANAGEMENT

Despite long-standing criticisms of the paradigm, New Public Management (NPM) retains a strong influence over organizations in public administration. Social Impact Bonds (SIB) are anoutcomes-oriented investment entity which has emerged from NPM with grand promises of social change. Building on a longitudinal case study of a health-based SIB, this paper identifies how key actors move away from NPM by resisting such management principles and shifttoward Public Value Management (PVM). The paper finds that this is possible when the public interest and performance objectives are designed with a public value orientation whilst other NPM principles shift over time through resistance and negotiation. The paper provides insight into how key actors re-organize to embed public value in a financing and public service delivery structure that is often regarded as flawed and inefficient. The paper offers several contributions to public value literature, including the role of the state, as well as the emerging literature on SIBs and outcomes-based contracts

In Vitro Assessment of the Synergy between Polymyxin B (PMB) and Polymyxin B Nonapeptide (PMBN) and Antibiotics on Biofilms from Diabetic Foot Infections

Background: The increasing resistance of Gram-negative bacteria isolated from nosocomial infections and chronic wounds, such as diabetic foot ulcers has renewed research interests in the use of polymyxins in the treatment of multidrug resistant infections. The added resistance conferred by biofilm development in such infections and the absence of novel antibiotics presuppose that polymyxins are the likely drugs of choice in spite of their nephrotoxicity. The effects of PMB and PMBN have been previously assessed on planktonic bacteria isolated from various infections. Methods: This current study assessed the synergy between a PMB/PMBN and two antibiotics (ceftazidime and levofloxacin) in an attempt to develop a strategy for biofilm disruption using the Minimum Biofilm Eradication Concentration Physiology and Genetic assay (MBEC™ P & G, Innovotech Inc, Edmonton, Alberta, Canada) according to manufacturer’s instructions. Klebsiella pneumoniae (K. pneumoniae) and Proteus mirabilis (P. mirabilis) biofilms of initial broth suspensions of 108 colony forming units per mL, cultivated on the pegs of the MBEC device were challenged with 5120 µg/mL of both ceftazidime and levofloxacin in a ten-fold dilution assay and in the presence of 100 and 500 µg/mL PMB and PMBN. Results: From table of results (Table 1), it can be deduced that both ceftazidime and levofloxacin are very effective in inhibiting biofilm development (as shown by percentage inhibition (PI)) when augmented with PMB and PMBN. This is about 100-fold increase in efficacy when compared to the antibiotics used on their own. The percentage reduction (PR) in biofilm was also increased considerably when PMB and PMBN concentrations were increased to 500 µg/mL. PMB was more effective than its less antibacterial derivative PMBN. Levofloxacin was also found to be more effective than ceftazidime when combined with both PMB and PMBN due to its enhanced cell-membrane permeability and as an anti-DNA replication uncoupling agent. Conclusion: The above results indicate that the synergy between antibiotics and cell membrane permeabilising agents may provide alternate strategies towards biofilm eradicatio

Selective migration and health

Using data from the Panel Study of Income Dynamics, we investigate the impact of health on domestic migration within the United States. We find that, for men below 60 years of age, a move from the middle to the bottom of the health distribution reduces mobility by 32-40%. Non-random attrition from the panel implies that these are lower bounds. By contrast, we find evidence that, among older men, there is higher mobility at the top and bottom of the health distribution than there is in the middle. For women, we find no evidence of a relationship between their own health and mobility, although spousal health does affect the mobility of married women

The in vitro assessment of the synergistic effects of antibiotics and wound dressings on biofilms from diabetic foot pathogens

The impact of biofilm in the effective control of wound microbiome is an ongoing dilemma which has seen the use of different treatment strategies. The effects of wound dressings and antibiotics on both planktonic bacteria and biofilms have been separately evaluated in previous studies. In this current study, the combined antimicrobial effects of some selected wound dressings (silver-impregnated: Acticoat and Silvercel; and honey-impregnated: Medihoney™ Apinate) and antibiotics (ceftazdime and levofloxacin) on Klebsiella pneumoniae and Proteus mirabilis in their quasi-biofilm state were assessed using zone of inhibition (ZOI) test. Before the addition of the wound dressings, bacterial suspension of 108 colony forming units per mL and different concentrations of ceftazidime and levofloxacin (256, 512, 1024 and 5120µg/mL) of a final volume of 1mL were inoculated on Mueller Hinton agar and allowed to dry. Wound dressings cut into circular shapes (2cm diameter) were aseptically placed on the agar plates and incubated at 35 – 37°C for 24 hours. ZOIs associated with Acticoat, Silvercel and Medihoney™ Apinate dressings were compared with that of Atrauman (non-medicated control) dressing. All three dressings showed significant (p < 0.05) biofilm-inhibiting activity against both bacteria at antibiotic concentrations of 1024 and 5120µg/mL with ZOI between 17.5 and 35mm