Monitoring and active stabilization of laser injection locking using beam ellipticity.

We unveil a powerful method for the stabilization of laser injection locking based on sensing variations in the output beam ellipticity of an optically seeded laser. The effect arises due to an interference between the seeding beam and the injected laser output. We demonstrate the method for a commercial semiconductor laser without the need for any internal changes to the readily operational injection locked laser system that was used. The method can also be used to increase the mode-hop free tuning range of lasers, and has the potential to fill a void in the low-noise laser industry.

Endline assessment of knowledge about sickle cell disease among the tribal community of Chhotaudepur district of Gujarat.

Sickle cell disease (SCD) is a significant public health concern in India, with one of the highest disability burdens worldwide. For the success of the disease prevention and control program that aims to reduce prevalence through health promotion and screening, the public's prior knowledge of the disease is important. Hence, this study was conducted to assess baseline knowledge of the disease and effects of health education and community mobilization program in the SCD endemic tribal community of Gujarat. This quasi-experimental study was conducted in three phases at Chhotaudepur district of Gujarat, India. Knowledge of the community was assessed through the administration of pretested quantitative questionnaire in 1646 and 1631 individuals respectively during formative and evaluation phases. Differences between the proportions of two phases were statistically assessed by chi-square tests. Despite 75.3% of respondents having heard of SCD before, only 20% could perceive the correct cause. It was improved by 42% post-intervention. During the evaluation, 83% respondents recognized the most common symptom of extreme pain, whereas 86.8% identified the correct diagnostic method. Seventy-seven percent respondents reported modern medicine as a treatment for SCD at endline. Knowledge and awareness about SCD were found inadequate in the community. However, health education intervention strategies effectively improved knowledge related to the disease and its causes, diagnosis, and treatment. Hence, urgent action is required to incorporate community mobilization and awareness generation strategies to mitigate the disease burden.

Prevalence of anemia in pre-school tribal children with reference to parasitic infections and nutritional impact.

Objectives: Anemia is a global health problem and has very high prevalence in developing as well as developed countries, particularly in children and women. The present study evaluates hematological predictors, nutrition deficiency, parasitic infections and their association with the prevalence of anemia. This analysis will help to identify the anemic status of tribal preschool children. Methods: This was a cross-sectional study conducted in 300 children (age: 6 months to 5 years) in Santrampur village, Gujarat. Blood was collected and used to determine complete blood count (CBC); we also performed ELISA (enzyme-linked immunoassay) for the estimation of ferritin, transferrin, sTfR (soluble transferrin receptor), vitamin B12 and vitamin B9 (folate). Stool samples were also collected and assessed by ELISA for Entamoeba histolytica, Giardia lamblia and Cryptosporidium parvum. Microscopy was used to screen samples for malaria. Results: Of the 300 children analyzed, 87.7% were anemic, 239 children were mildly anemic, 20 were moderately anemic and 4 were severely anemic. Mean Hb level was 9.49 ± 1.47 g/dL; males and females had an Hb level of 9.39 ± 1.59 g/dL and 9.58 ± 1.34 g/dL, respectively. Twenty-six children had sickle cell anemia and five had thalassemia. Over 50% of the children had vitamin B12 and B9 deficiency and 16% had abnormalities in CRP (C-reactive protein) levels. Parasitic infection by C. parvum was positively associated the anemia followed by the prevalence of G. lamblia and E. histolytica. Conclusion: An increased awareness of parents in the improvement of sanitary facilities and nutritional counselling with regards to iron-rich food consumption is recommended to if we are to prevent anemia among pre-school children. To reduce parasitic infestation, effective periodic deworming measures are also recommended.

An epidemiological investigation of a multisource outbreak of Crimean-Congo hemorrhagic fever in Gujarat.

It all started with the report from Shalby Hospital, Ahmedabad of two deaths with unusual presentation on Jan 18, 2011. Immediately investigations were carried out; to identify the etiological agent, source of outbreak, and mode of transmission, as well as, to propose a control measure based on the findings of the investigation. Extensive literature search, discussion with various scientific institutions, scientists and laboratory diagnosis suggested it to be case of Crimean-Congo Hemorrhagic Fever (CCHF). Accordingly a Case definition was worked out to further investigate the episode/outbreak. Door-to-door survey was carried out and hospital records were scrutinized. Collected data was analyzed in terms of time, place, and person. Laboratory investigation reports of case patients were also collated. We conducted environment investigation to find out the source of Infection. A total 13 case patients of CCHF were identified out of which 9 are positive for CCHF virus, 2 were negative for CCHF virus and in 2 instances, samples could not be taken because of early deaths of the cases. Among these 13 cases, 30.76% mortality rate was noted. Cases were reported in middle age group only. Environmental investigation also confirmed the presence of CCHF virus in Ticks. The outbreak was due to CCHF virus. State wide sero surveillance in animals is needed to identify prevalence of disease in Gujarat.