Epidemiology of dry eye disease in Africa: The sparse information, gaps and opportunities.

Dry eye disease (DED) is an increasingly significant clinical problem in developing countries and/or emerging economies. Existing studies on DED conducted in these areas have largely reported on associations between DED and infectious disease (trachoma) and malnutrition (hypovitaminosis A), but current trends of industrialization, urbanization, and modernization in these areas could result in a shift to other forms of DED. Herein, we review the epidemiology of DED in these geographic areas, highlighting potential causes and risk factors of DED while presenting information on diagnostic tools and algorithms and insight into some treatment modalities of DED that could prove useful to clinicians and investigators in these regions.

Engineered Unique Elastic Modes at a BaTiO_{3}/(2×1)-Ge(001) Interface.

The strong interaction at an interface between a substrate and thin film leads to epitaxy and provides a means of inducing structural changes in the epitaxial film. These induced material phases often exhibit technologically relevant electronic, magnetic, and functional properties. The 2×1 surface of a Ge(001) substrate applies a unique type of epitaxial constraint on thin films of the perovskite oxide BaTiO_{3} where a change in bonding and symmetry at the interface leads to a non-bulk-like crystal structure of the BaTiO_{3}. While the complex crystal structure is predicted using first-principles theory, it is further shown that the details of the structure are a consequence of hidden phases found in the bulk elastic response of the BaTiO_{3} induced by the symmetry of forces exerted by the germanium substrate.

Prevalence of Overweight and Obesity among Students in the Kumasi Metropolis.

The aim was to determine the prevalence of obesity and overweight among students in the Kumasi metropolis. In a descriptive cross-sectional study, 500 students aged 10 to 20 years were examined from two junior high schools selected by multistage sampling technique and three randomly selected senior high schools. Height and weight were measured in all participants and the body mass index (BMI) of each individual was calculated. Body mass index classes were calculated according to the International Obesity Task Force standards. Out of the 500 students, 290 (58.00%) were males and 210 (42.00%) were females. The prevalence of underweight, normal weight, overweight, and obesity was 7.40%, 79.60%, 12.20%, and 0.80%, respectively. Overweight was more prevalent among students than obesity. There is therefore the need to establish effective public health promotion campaigns among students in order to curtail future implications on health.

Presbyopia among public senior high school teachers in the Kumasi metropolis.

BACKGROUND: Presbyopia if uncorrected causes inability to see and do near work. It is unavoidable as one ages. High school teachers whose work depends much on near work need proper and adequate correction of their presbyopia to increase effectiveness and efficiency. OBJECTIVES: The aim was to determine the uptake of correction and prescription for presbyopia of presbyopic teachers of public Senior High School (S.H.S.). DESIGN: Descriptive cross-sectional study. METHODS: The study was conducted in 12 public S.H.S. in the Kumasi, with a total sample size of 298. Questionnaire was administered to teachers. Their visual acuity, refraction and ophthalmoscopy were done. RESULTS: The prevalence of presbyopia among the teachers was 68.1%. Out of the number examined 197(66.1%) were males and 10(33.9%) were females. Amongst the presbyopes 60 did not have presbyopic correction, representing 29.6% of the presbyopes. A total of 52 presbyopic teachers required an add of +2.00DS and this was the highest diopter of correction needed (25.6%). Among those with presbyopic correction 55.5% of them use single vision type of correction whiles the remaining 44.5% use bifocals. Out of the 48% presbyopic teachers who have had their presbyopia corrected before, 6% were not wearing their correction. CONCLUSION: The study has demonstrated a relatively higher prevalence of uncorrected presbyopia amongst teachers in public Senior High Schools in the Kumasi Metropolis of 29.6%. Among those with correction 6 % were not using their correction. Proper and adequate correction is needed by presbyopic teachers through screening to ensure their maximum performance.

Structural basis for the conducting interface between LaAlO3 and SrTiO3.

The complete atomic structure of a five-monolayer film of LaAlO3 on SrTiO3 has been determined for the first time by surface x-ray diffraction in conjunction with the coherent Bragg rod analysis phase-retrieval method and further structural refinement. Cationic mixing at the interface results in dilatory distortions and the formation of metallic La(1-x)SrxTiO3. By invoking electrostatic potential minimization, the ratio of Ti{4+}/Ti{3+} across the interface was determined, from which the lattice dilation could be quantitatively explained using ionic radii considerations. The correctness of this model is supported by density functional theory calculations. Thus, the formation of a quasi-two-dimensional electron gas in this system is explained, based on structural considerations.