Search

A smartphone is a powerful learning aid in the hands of a large section of students around the world. The camera of the phone can be used for several learning purposes apart from its obvious purpose of photographing. If the focal length of the lens of the camera can be determined, several experiments in optics can be performed with it. In some recent works, the method of determination of the focal length has been discussed. When a real image of an object is formed by a lens of known focal length, one can determine either the distance or the transverse magnification of the object if the other is known. In this work we have shown that we can determine both the transverse size and the distance of an object, by photographing it from two positions, separated by a distance along the line of sight of the camera., The paper is of length 10 pages including two figures. The article has been accepted by The Physics Teacher, After it is published, it will be found at https://doi.org/10.1119/5.0065457

A smartphone can be used for many physics experiments by using the sensors built into the phone. The complementary metal oxide semiconductor (CMOS) (charge-coupled device, CCD) sensor of the camera records the images of objects photographed in pixels. The width of the image can be read off with micron level accuracy with the help of software available freely from the internet. If the dimensions of the object in the direction transverse to the viewing direction of the camera are known, the magnification of the object photographed can be determined accurately. A smartphone camera is a compound lens comprising a number of very thin lenses. A single thin lens is equivalent, as far as the transverse magnification is concerned, to a compound lens of the smartphone, when the thin lens has the same focal length as the effective focal length of the compound lens and is placed at its first principal plane. This property allows us to find experimentally the effective focal length of the compound lens of the camera accurately, using the thin lens equation. Once the focal length of the camera is known, the distance of an object can be determined by finding its magnification from the photograph. We have determined the refractive index of water accurately by photographing the apparent position of an object immersed in it. By determining the magnifications, we have found the real and apparent depths of the object. The ratio of these depths gives the refractive index. We have determined the refractive index of glass also using some thin glass slides.

Ethiopia is home to a diverse gene pool of indigenous sheep populations. Therefore, a better understanding of genetic variation holds the key to future utilization through conservation. Three of these breeds, Afar, Blackhead Somali, and Hararghe Highland, are found in eastern Ethiopia where they contribute significantly to the livelihood of most pastoralist, agro-pastoralist, and smallholder farmers. These indigenous sheep are recognized on the basis of morphotype and their genetic distinction remains unknown. Here, to assess genetic variation, and matrilineal genetic origin and relationship of fat-rumed sheep found in eastern Ethiopia, 300 individuals from the three breeds were genotyped for 22 microsatellite markers and sequenced for the mitochondrial DNA displacement loop (mtDNA d-loop) region. The overall HO and HE were 0.57 and 0.75, respectively. Differentiation statistics revealed that a high proportion (97%) of the total genetic variation was explained by differences between individuals within populations. Genotype assignment independent of the population of origin showed K = 2 to be the optimum number of genetic backgrounds present in the dataset. This result was further confirmed by mtDNA D-loop sequences comparison in which the matrilineal genetic origin of eastern Ethiopia sheep is from two haplotype groups (types A and B) among the five haplotypes globally observed. Taken together, our findings suggest that the sheep populations from three breeds originated from two ancestral genetic backgrounds that may have diverged prior to their introduction to Ethiopia. However, to obtain a complete picture of the evolutionary dynamics of Ethiopian indigenous sheep, more samples and populations from within and outside of the country will need to be analyzed.

Background India is home to one in 14 of all chronic hepatitis B virus (HBV) cases, meaning that it is important to develop HBV interventions that are applicable in the Indian context. Vaccination is the foremost tool for interrupting the HBV infection cycle. HBV vaccination was not included in India’s government-sponsored expanded immunisation program until 2011, and many children born earlier remain unvaccinated. This study sought to observe the impact of the HOPE Initiative’s school-based intervention to increase vaccination coverage by increasing HBV awareness among students in Lucknow, Uttar Pradesh. Methods At 430 schools in the administrative areas within and surrounding Lucknow, students viewed an educational documentary film on HBV and completed two questionnaires, one immediately before the screening and the other six weeks later. Both questionnaires asked the same 14 questions, which were organized into five domains: knowledge of the magnitude of the problem of HBV; knowledge of modes of HBV transmission; knowledge of consequences of HBV infection; awareness of HBV; and attitudes regarding HBV. The baseline questionnaire also asked students whether they had been vaccinated against HBV. At two-year follow-up, researchers measured vaccination levels at a subset of 30 intervention schools and six non-intervention schools to further assess the impact of the intervention. Results Baseline questionnaires were completed by 11,250 students, and post-intervention questionnaires, by 9698 students. Scores for knowledge about the magnitude of the HBV problem improved from 41% at baseline to 74% at follow-up, and scores for knowledge about modes of transmission, from 38% to 75% (p

Background and Aim: The Ogaden cattle is one among the tropical cattle breeds (Bos indicus) widely distributed in eastern and south eastern part of Ethiopia. The breed has been evolved in arid and semi arid agro-ecological setup, but later on distributed and adapted to the wide agro-ecological zones. Because of its multi-purpose role, the Ogaden cattle have been used for milk, beef, and income generation. Information on the inherent genetic diversity is important in the design of breeding improvement programmes, making rational decisions on sustainable utilization and conservation of Animal Genetic Resources. Limited information is available about genetic variation of Ogaden breed at molecular level. The present investigation was aimed to study the biochemical polymorphism at the Hemoglobin (Hb) locus. Materials and Methods: Blood samples collected from 105 Ogaden cattle maintained at Haramaya beef farm by jugular vein puncture were subjected to agarose gel electrophoresis [pH range 8.4-8.5] to study the polymorphic activities of haemoglobin. Results: Three types of phenotypes were detected i.e. a slow moving (AA) band, fast moving (BB) band and a combination of slow + fast moving bands (AB). The frequency of the fast moving band was less [13 (12.3%)] than the slow moving band [57 A (54.2%)]. Both slow & fast moving phenotype was observed in 35 (33.3%) animals. The gene frequency of HB allele was B 0.709 and that of HB allele 0.291. 2 Conclusion: The distribution of phenotypes was in agreement with codominant single gene inheritance. The Chi-square (˜ ) test revealed that the population is under Hardy-Weinberg equilibrium.

1. A study of primary wing feather development rate in guinea fowl revealed genetic control through a single pair of sex‐linked alleles. The allele for slow feathering (K) was dominant over that for rapid feathering (k+).. 2. Wing feather sexing showed 94% accuracy in 10‐d‐old keets. 3. Incidence of rapid feathering allele (k+ ) was higher in the population selected for high body weight compared to the unselected population.