HIV risk among young Ghanaians in high school: validation of a multidimensional attitude towards condom use scale

Condom use remains low among sexually active youth in sub-Saharan Africa. Theoretical and empirical evidence suggests that attitudes towards condom use are important predictors of actual condom use. However, few attempts have been made to systematically develop a valid scale that measures attitudes towards condom use among youth, particularly high school students in sub-Saharan Africa. Using the health belief model, we developed an instrument that measures such attitudes. We analysed survey data collected from 6252 Ghanaian junior high school students. We assessed construct validity using confirmatory factor analysis. Results indicate that attitudes towards condom use among young Ghanaians are best represented by a multidimensional construct. Young Ghanaians differentiate constructs related to perception of benefits and barriers to condom use, as well as perception of severity and susceptibility to HIV. This instrument offers a valid tool for assessing high school students' attitudes towards condom use and their HIV risk

Quasinormal ringing of acoustic black holes in Laval nozzles: Numerical simulations

Quasinormal ringing of acoustic black holes in Laval nozzles is discussed. The equation for sounds in a transonic flow is written into a Schr\"{o}dinger-type equation with a potential barrier, and the quasinormal frequencies are calculated semianalytically. From the results of numerical simulations, it is shown that the quasinormal modes are actually excited when the transonic flow is formed or slightly perturbed, as well as in the real black hole case. In an actual experiment, however, the purely-outgoing boundary condition will not be satisfied at late times due to the wave reflection at the end of the apparatus, and a late-time ringing will be expressed as a superposition of "boxed" quasinormal modes. It is shown that the late-time ringing damps more slowly than the ordinary quasinormal ringing, while its central frequency is not greatly different from that of the ordinary one. Using this fact, an efficient way for experimentally detecting the quasinormal ringing of an acoustic black hole is discussed.Comment: 9 pages, 8 figures, accepted for publication in Physical Review

Assets and Child Well-Being in Developing Countries: A Research Review

The impact of assets on child well-being in developing countries has received considerable attention in the last decade. Increased recognition of the critical role played by assets in enhancing children’s well-being has spurred efforts to study the relationship between assets and a range of outcomes for children. This chapter reviews current studies (i.e., conducted within the past 10 years) that explore the relationship of asset ownership and a range of outcomes. The studies we have included in this review illustrate the impact that assets can have on children’s outcomes in the area of health, education, and child labor. Overall, the studies reviewed show that asset ownership improves children’s health conditions, advance schooling outcomes, and decrease incidence of child labor. Further research on the asset effects for child outcomes can inform progressive asset-building initiatives that will provide impetus for programs and policies to enhance household well-being in developing countries

What Controls Activity Trends of Electrocatalytic Hydrogen Evolution Reaction?-Activation Energy Versus Frequency Factor

Renewable energy storage via water electrolysis strongly depends on the design of electrified electrode–electrolyte interfaces at which electricity is converted into chemical energy. At the core of the hydrogen evolution reaction (HER) and the oxygen evolution reaction conversion efficiency are interfacial processes with complex dynamic mechanisms, whose further acceleration is practically impossible without a thorough fundamental understanding of electrocatalysis. Here, we communicate new experimental insights into HER, which will potentially further deepen our general understanding of electrocatalysis. Of special note is the very surprising observation that the most active metals (i.e., noble metals) for HER, which exhibit the lowest overpotentials at a defined current density, exhibit the highest activation energies in comparison to the other metals from the d-block. This suggests a major, if not dominant, impact of the frequency factor on activity trends and the need for deeper reconsideration of the origins of electrocatalytic activity

The Effect of Iron Impurities on Transition Metal Catalysts for the Oxygen Evolution Reaction in Alkaline Environment: Activity Mediators or Active Sites?

There is an ongoing debate on elucidating the actual role of Fe impurities in alkaline water electrolysis, acting either as reactivity mediators or as co-catalysts through synergistic interaction with the main catalyst material. This perspective summarizes the most prominent oxygen evolution reaction (OER) mechanisms mostly for Ni-based oxides as model transition metal catalysts and highlights the effect of Fe incorporation on the catalyst surface in the form of impurities originating from the electrolyte or co-precipitated in the catalyst lattice, in modulating the OER reaction kinetics, mechanism and stabilit

Parental Involvement\u27s Effects on Academic Performance: Evidence From the YouthSave Ghana Experiment

Research in developed countries suggests that parental involvement is associated with youth academic success, but little is known about this relationship in developing countries. Further, it is unclear which type of parental involvement may impact the academic performance of youth from developing countries. This study examines whether (a) parental involvement at home and in school are meaningfully different constructs in a population of Ghanaian youth and their parents and (b) parental involvement predicts academic performance. Results suggest that parental involvement is a bidimensional construct consists of home and school involvement. The effect of parental involvement on youth academic performance appears to be a function of the type of involvement. Home-based parental involvement is associated positively with academic performance, while school-based parental involvement has a negative association. Parents can model positive attitudes and behaviors toward school and convey the importance of school

Youth in the Ghana Experiment: Characteristics and Living Conditions

Youth in the Ghana Experiment: Characteristics and Living Condition