Harsh Physical Discipline: Prevalence and Associated Factors Among Primary Caregivers of Pre-school Children in Ethiopia.

Harsh parental discipline is ineffective and potentially harmful to children, yet it is still common, particularly in many African countries. Culturally responsive education programs are needed to shift parenting practices in African countries, but there is limited baseline research to inform such efforts. This study's objectives were to establish the baseline prevalence of harsh physical discipline practices among primary caregivers of pre-school children in Ethiopia and to identify associated factors to inform intervention efforts. The well-established Parent-Child Conflict Tactics Scale section on physical assault was translated and administered to primary caregivers of 1139 pre-school children aged 4-6 years sampled from four regions of Ethiopia. Trained interviewers also collected basic socio-demographic data. Based on caregiver report, 52.5% (n = 598) of the children had experienced harsh physical discipline and an additional 12.7% (n = 145) experienced moderate physical discipline in their lifetimes. After controlling for covariates, the factors significantly related to increased likelihood of harsh discipline were geographic region, female caregivers, lack of employment, at least moderate perceived social status, and non-Muslim religion. These data establish a baseline from which to evaluate the impact of future educational interventions designed to shift practices. Information about the correlates can be used to tailor such intervention efforts toward those most likely to use harsh discipline practices.

Theoretical study on the interaction of iodide electrolyte/organic dye with the TiO2 surface in dye-sensitized solar cells.

The iodide/triiodide interaction with the dye on a semiconductor surface plays a significant role in understanding the dye-sensitized solar cells (DSSCs) mechanism and improving its efficiency. In the present study, density functional theory (DFT) calculations were used to determine the interaction between the complexed iodide redox couple with dye/TiO2 for the relevance of DSSCs. Three new metal-free organic dyes noted as D1Y, D2Y and D3Y, featured with D-π-A configuration were designed by varying functional groups on the donor moiety. We analyzed the structural and electronic properties of these dyes when standing alone and being adsorbed on the oxide surface with the iodide electrolyte. Of the designed dyes, the incorporation of a strong donor unit in D1Y and D2Y sensitizers in conjunction with iodide electrolytes on the TiO2 surface provides better adsorption and electronic properties in comparison to those from the dye alone on the TiO2 surface. Analysis of density of states (DOS) indicates that the introduction of a strong electron-donating group into the organic dye, mainly D1Y and D2Y with an iodide electrolyte on the surface remarkably upshifts the Fermi energy, thereby improving the efficiency of the DSSCs by an increase of the open-circuit voltage (Voc). The present finding constitutes the basis for achieving a deeper understanding of the intrinsic interaction taking place at the electrolyte/dye/TiO2 interface and provides us with directions for the design of efficient dyes and redox electrolytes for improving DSSCs.

Effects of the terminal donor unit in dyes with D-D-π-A architecture on the regeneration mechanism in DSSCs: a computational study.

This theoretical study on dye-sensitized solar cells (DSSCs) includes design strategies for dye donor units to improve the efficiency of DSSCs, and further illuminates the organic dye regeneration mechanism. We have designed a series of new organic sensitizers based on a D-D-π-A architecture to exhibit easy electron transfer and to have remarkable light harvesting properties in the visible region by density functional theory (DFT) and time-dependent (TD)-DFT calculations. Furthermore, the interaction of the organic sensitizers with the conventional redox electrolyte using the triiodide/iodide couple (I3-/I-) is investigated. Our calculations indicate that incorporation of strong electron-donating groups remarkably improves the charge transfer characteristics, optoelectronic properties and rapid dye regeneration as compared to less electron donating substituents. In addition, our study demonstrates the possibility of second electron injection from the oxidized dye complex to the semiconductor surface, which further confirms our recently proposed dye regeneration mechanism.