Online access by adolescents in Accra: Ghanaian teens' use of the internet for health information.

In developed countries, adolescents go online to find information about health; however, little is known about the online practices of youth from developing countries. This study's purpose was to explore and provide current information, drawn from adolescents living in Ghana's capital city of Accra, on the use of the Internet as a health information source. Using a representative sample of in-school adolescents and a convenience sample of out-of-school adolescents, 778 15- to 18-year-olds completed a detailed media and health information survey. Two-thirds (66%) of the in-school youth and approximately half (54%) of the out-of-school youth had previously gone online. Of all these Internet users, 53% had sought online health information, and this percentage did not differ significantly by gender, age, ethnicity, or even school status. Youth reported great interest, high levels of efficacy, and positive perceptions of online health information. Although more research should be conducted, this study offers exciting data on the potential to deliver, via the Internet, health information to youth in developing countries. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparative physicochemical analysis of suspended and immobilized cultivation of Chlorella sp.

BACKGROUND: Immobilized cultivation of microorganisms is gaining interest in the microalgae industry. In this study, a novel microalgae polymeric carrier, sodium cellulose sulphate/poly‐dimethyl‐diallyl‐ammonium chloride (NaCS‐PDMDAAC) capsule system, was employed to immobilize Chlorella sp. Microalgae cultivation was performed under immobilized and suspended conditions, and the resulting cells were characterized biochemically and physically. RESULTS: Experimental results indicated that microalgae cells cultivated under NaCS‐PDMDAAC immobilized conditions have a robust morphology, a smaller average cell size of 2.92 µm and a higher Zeta potential of ? 17.10 mV than the suspended cells with a cell size of 6.81 µm and Zeta potential of ? 32.90 mV. The immobilized microalgae cells displayed a total lipid content of 14.85%, and a chlorophyll content of 3.36%, slightly higher than those obtained from the suspended cells. CONCLUSION: These differences are critical to further explore the impact of immobilized microalgae cultivation systems for specific biotechnological applications. © 2012 Society of Chemical Industry     

Effects of admission and treatment strategies of DWI courts on offender outcomes

Purpose

The purpose of this study is to classify DWI courts on the basis of the mix of difficult cases participating in the court (casemix severity) and the amount of involvement between the court and participant (service intensity). Using our classification typology, we assessed how casemix severity and service intensity are associated with program outcomes. We expected that holding other factors constant, greater service intensity would improve program outcomes while a relatively severe casemix would result in worse program outcomes.

Methods

The study used data from 8 DWI courts, 7 from Michigan and 1 from North Carolina. Using a 2-way classification system based on court casemix severity and program intensity, we selected participants in 1 of the courts, and alternatively 2 courts as reference groups. Reference group courts had relatively severe casemixes and high service intensity. We used propensity score matching to match participants in the other courts to participants in the reference group court programs. Program outcome measures were the probabilities of participants’: failing to complete the court's program; increasing educational attainment; participants improving employment from time of program enrollment; and re-arrest.

Results

For most outcomes, our main finding was that higher service intensity is associated with better outcomes for court participants, as anticipated, but a court's casemix severity was unrelated to study outcomes.

Conclusions

Our results imply that devoting more resources to increasing duration of treatment is productive in terms of better outcomes, irrespective of the mix of participants in the court's program.     

Modeling Nitrogen Dynamics under Maize on Ferralsols in Western Africa

Mathematical models may be applied to simulate nitrogen (N) dynamics under different types of soil and environmental conditions to assess fertilizer N needs or to predict nitrate-N (NO₃–N) potential impact on water quality. The research version of LEACHMN was evaluated using data from lysimeters and field experiments conducted at the University of Lomé Research Farm in Togo, West Africa. The model was calibrated for the mineralization, nitrification, denitrification and volatilization rate constants with measured values of NO₃–N leaching losses and maize (Zea mays L.) N uptake collected from the lysimeter experiment. The model was then tested against measured data of soil profile NO₃–N distribution and maize N uptake from the field experiment and drainage water collected from the lysimeter experiment. The testing procedure involved two scenarios with increasing level of generalization for transformation rate constants (i) rate constant values for each N treatment and (ii) rate constant values averaged over N treatments. LEACHMN effectively simulated drainage water volume and rate (r²= 0.94 to 0.99). During the calibration efforts, the model satisfactorily simulated NO₃–N leaching losses (r²= 0.98) and accurately simulated growing season cumulative maize N uptake. The variation of the calibrated rate constants among N treatments was primarily linked to the model's incapacity to accurately simulate maize N uptake throughout the growing period. When tested using calibrated rate constants for each treatment, the model was successful in simulating soil profile NO₃–N distribution (r² = 0.52 to 0.94). Simulations of soil profile NO₃–N distribution were not satisfactory (r²= 0.03 to 0.49) when rate constants were averaged over N treatments. Improvement of the plant N uptake routine of the model is needed to increase the model’s performance. Using the LEACHMN model to predict N dynamics on the Ferralsols of southern Togo appears feasible when appropriate calibrations are performed.     

A comparison between the life cycle cost of gravel and of bituminous surfacing options for feeder roads in Ghana

Feeder roads, which constitute a key component of rural transport infrastructure, play a vital role in rural development, but only 5% of the total feeder road network in Ghana has bituminous seal surfacing. The remaining 95% have either gravel or earth surfacing. However, gravel surfacing (G-S) is known to deteriorate rather rapidly necessitating expensive frequent maintenance while bituminous surfacing offers a more durable surfacing. Various life cycle cost studies have suggested that even though G-S may have lower initial construction costs, they tend to have higher life cycle costs than bituminous seal surfaced ones. However, since most of these studies are based on ideal maintenance practices, their conclusions do not reflect actual field conditions. This study seeks therefore to compare the life cycle cost of G-S with that of bituminous seal surfacing options for engineered feeder roads in Ghana using actual cost data. Data were collected from eight feeder road projects with G-S and a similar number with bituminous surfacing from six regions of Ghana completed between 2010 and 2013. The life cycle cost for each road was computed using a discount rate of 12% and an inflation rate of 15% over an analysis period of 21 years. The results for G-S are then compared with those for single bituminous seal surfacing and for double bituminous seal surfacing. The results are further compared with those from trial sections of an experimental study of Otta seal surfacing using natural gravel and using crushed rock as aggregates. The results suggest that based on the high initial construction costs of bituminous seal surfacing and actual low maintenance intervention practices, G-S remain the least cost option. The study recommends the need for alternative surfacing technology that does not involve bitumen.     

Growth medium selection and its economic impact on plasmid DNA production

Current developments in gene medicine and vaccination studies are utilizing plasmid DNA (pDNA) as the vector. For this reason, there has been an increasing trend towards larger and larger doses of pDNA utilized in human trials: from 100-1000 microg in 2002 to 500-5000 microg in 2005. The increasing demand of pDNA has created the need to revolutionalize current production levels under optimum economy. In this work, different standard media (LB, TB and SOC) for culturing recombinant Escherichia coli DH5alpha harbouring pUC19 were compared to a medium optimised for pDNA production. Lab scale fermentations using the standard media showed that the highest pDNA volumetric and specific yields were for TB (11.4 microg/ml and 6.3 microg/mg dry cell mass respectively) and the lowest was for LB (2.8 microg/ml and 3.3 microg/mg dry cell mass respectively). A fourth medium, PDMR, designed by modifying a stoichiometrically-formulated medium with an optimised carbon source concentration and carbon to nitrogen ratio displayed pDNA volumetric and specific yields of 23.8 microg/ml and 11.2 microg/mg dry cell mass respectively. However, it is the economic advantages of the optimised medium that makes it so attractive. Keeping all variables constant except medium and using LB as a base scenario (100 medium cost [MC] units/mg pDNA), the optimised PDMR medium yielded pDNA at a cost of only 27 MC units/mg pDNA. These results show that greater amounts of pDNA can be obtained more economically with minimal extra effort simply by using a medium optimised for pDNA production.     

How Much Extra Affordable Housing is Needed in England?

Booming housing markets in the UK have once again brought into sharper focus the issues of housing affordability, housing need and ‘affordable housing’ solutions. This paper reviews issues in the measurement of problems of affordability, particularly access to homeownership, and reports on modelled estimates for England at regional and local levels. These models provide a method for comparing pressures in different areas, but also for measuring market change over time and its relationship with the economy. They are also useful for identifying and assessing the scope for ‘intermediate’ forms of provision between conventional homeownership and social renting. Measures of recent and prospective needs for additional affordable housing provision, derived from this analysis of affordability, are presented and assessed. These findings are linked to a broader contemporary policy debate about housing and planning policy in England.