Master of Science

thesisThis thesis presents an improved method for reconstructing the spectra of astronomical objects from two-dimensional (2D) charge-coupled device (CCD) images. We address two issues, namely, estimation of calibration matrix for a CCD, and reconstruction of spectra of astronomical objects, which is referred to as extraction. In the rst part of the thesis we estimate the elements of system calibration matrix by modeling the two-dimensional point-spread functions (PSF) in calibration images. Our PSF model is valid for arbitrarily complicated 2D point-spread functions, as compared to the state-of-art extraction methods which are valid only for class of separable PSFs. We present various models for PSFs and give a quantitative comparison between the models. In the second part of the thesis the system calibration matrix is used to extract the spectra of a particular type of calibration images called arc-images. We also address the issue of resolution and covariance in the extracted spectra, and present a method that establishes optimal properties in both these regards. We also compare quantitatively the performance of our extraction technique with the state-of-art extraction technique. The work presented in this thesis can be deployed for estimation of spectra of faint galaxies in presence of strong night-sky foregrounds

Factors determining successful intrauterine insemination

Background: Infertility is defined as failure to conceive even after one year of regular, frequent and unprotected intercourse. Infertility can be attributed to male causes in approximately 25-40% cases, female causes in 40-50% cases, both in 10-20% and unexplained causes in 10-15% cases. Artificial insemination (Intrauterine Insemination) involves placement of processed sperms from husband (AIH – artificial insemination homologous) or from donor (AID – artificial insemination donor) into the female genital tract.Methods: Objectives of the study were to do sperm preparation to obtain normal good quality motile sperms, to perform intrauterine insemination using husband semen around the time of ovulation, to study factors responsible for successful pregnancy rates by this method. Out of 100 infertile females recruited for the study 34 underwent artificial insemination by IUI with controlled ovarian hyper stimulation. Sperms were washed by density gradient centrifugation or by a direct swim-up technique that does not involve centrifugation.Results: Overall pregnancy rate per patient for male factor infertility was 23.52%. None of the patients consented for more than three cycles of IUI. Maximum pregnancy was achieved in third cycle of IUI. Sperm motility >40% was related with pregnancy in 8 cases. Duration of infertility didn’t influence pregnancy rate. The majority of pregnancies were achieved in the age group of 25-29 years (50%). No pregnancy occurred with >15 years of infertility.Conclusions: This study concluded that intrauterine insemination after ovarian stimulation or controlled ovarian hyperstimulation is a successful and efficacious therapy for infertility

Characteristics of infertile couples attending OPD of a teaching hospital

Background: Infertility is defined as failure to conceive even after one year of regular, frequent and unprotected intercourse. Infertility has, in the last few years surfaced in society as a significant problem affecting as many as 15% of couples. This study aimed at identifying the characteristics of infertility among Indian couples.Methods: The present study was carried out on 100 infertile couples attending the OPD of upper India sugar exchange maternity hospital attached to GSVM medical college, Kanpur, other hospital and nursing homes of Kanpur. Both the partners were completely evaluated by taking proper history, examination and investigation to assess the cause of infertility.Results: Majority of female partners were between ages of 25-29. Female factors were found in 45% couples and male factors in 30 % couples. Among female factors, tuboperitoneal factor was found in 32% cases and ovulatory factor was found in 40% cases. Oligospermia was the commonest cause in male factor infertility.Conclusions: From this study we concluded that infertility is a public health problem in India and the main infertility pattern is a primary rather than secondary infertility

Glaucoma: role of neuroprotective agents

Glaucoma is an optic neuropathy, considered as the second leading cause of blindness worldwide. Glaucoma is characterized by selective death of retinal ganglion cells (RGC) and a progressive loss of vision. Elevated intraocular pressure (IOP) is one of the most important risk factors for developing glaucoma and hence we mainly focus on lowering IOP to arrest the progression of glaucoma. However, many patients continue to demonstrate a clinically downhill course despite the control of initially raised IOP. In fact, some patients develop what is called normal tension glaucoma, not associated to an increased IOP. This emphasizes that several pressure-independent mechanisms are responsible for the development and progression of glaucomatous neuropathy and that high IOP and vascular insufficiency in the optic nerve head are only risk factors for the development of glaucoma, and are not the only target for the treatment of glaucoma. The reason is that the process of RGC death is thought to be biphasic, and the primary injury is followed by a slower secondary degeneration related to a noxious environment surrounding the apoptotic cells. This environment is characterized by changes in the extra-cellular ionic concentrations, increased amounts of free radicals, neurotrophins (NT) depletion and increased glutamate-induced excitotoxicity due to high extra-cellular glutamate levels, which binds to N-methyl-D-aspartate (NMDA) receptors leading to an abnormally high intracellular Ca2+ concentration. Neuroprotection is a process that attempts to preserve the remaining cells that are still vulnerable to damage, and the main aim of neuroprotective therapy is to employ pharmacologic or other means to attenuate the hostility of the environment surrounding the degenerating cells, or to supply the cells with the tools to deal with this aggression, providing resilience to the insult. Several agents have been reported neuroprotective in glaucoma, both in clinical assays, such as Ca2+ channel blockers, and in experimental studies, such as betaxolol, brimonidine, NMDA antagonists, nitric oxide synthase inhibitors, NT and Ginkgo biloba extract. Most neuroprotective agents for glaucoma have proved beneficial effects over RGC, not showing effects over IOP. However, when analyzing classically used medications for glaucoma, it becomes difficult to understand if its effect over the progression of glaucoma is due to neuroprotective pathways or by means of lowering IOP. The ideal anti-glaucoma drug would be one that when applied topically, reduces IOP, but also probes to reach the retina in appropriate amounts, and activates specific receptors in the retina to attenuate RGC death. In this review, we will examine currently advocated neuroprotective drug-based strategies in the potential management of glaucoma

Caesarean section in a tertiary care centre

Background: Caesarean section constitutes a major surgical procedure characterized with morbidity even if it is performed a planned procedure. Postoperative infection in obstetrics continues to affect the practice of every surgeon. Infection can cause an increase in patient’s stay in the hospital, create discomfort, cause disfigurement and lead to morbidities to the patient. Thus, preventive measures need to be constantly evaluated and updated and hence authors have to study and analyse prevalence of postoperative infectious morbidities.Methods: The study was conducted in an Urban Based Medical College Hospital in Ahmedabad. It was a retrospective cross-sectional study of 50 cases of patients who suffered infectious complications post caesarean from 1st March 2019 to 31st March 2020.Results: The prevalence rate of surgical site infection in my study is 5.9% whereas of post-operative puerperal sepsis is 0.6%, of post-operative urinary tract infection is 1.09%, of post-operative breast abnormalities is 0.16%. The most common infectious morbidity amongst all was surgical site infection (surgical site) infection and its prevalence was 5.9%.Conclusions: The development of post-operative infection is an important event that can be prevented by taking proper precautions and following prescribed guidelines. There should be specific use of antibiotics in the post-operative period. In the event of early signs of sepsis antibiotics should be administered properly as per culture sensitivity report. The decrease in infection rate also indirectly reduce the health costs involved in treating them post operatively

Transcriptome and metabolite analyses in Azadirachta indica: identification of genes involved in biosynthesis of bioactive triterpenoids

Bhambhani S, Lakhwani D, Gupta P, et al. Transcriptome and metabolite analyses in Azadirachta indica: identification of genes involved in biosynthesis of bioactive triterpenoids. SCIENTIFIC REPORTS. 2017;7(1): 5043.Azadirachta indica A. Juss, commonly known as Neem, is the reservoir of triterpenoids of economic importance. Metabolite analysis of different developmental stages of leaf and fruit suggests tissue-specific accumulation of the major triterpenoids in this important tree. Though biosynthesis of these complex molecules requires substrate flux from the isoprenoid pathway, enzymes involved in late biosynthetic steps remain uncharacterized. We established and analyzed transcriptome datasets from leaf and fruit and identified members of gene families involved in intermediate steps of terpenoid backbone biosynthesis and those related to secondary transformation leading to the tissue-specific triterpenoid biosynthesis. Expression analysis suggests differential expression of number of genes between leaf and fruit and probable participation in the biosynthesis of fruit-specific triterpenoids. Genome-wide analysis also identified members of gene families putatively involved in secondary modifications in late biosynthetic steps leading to the synthesis of highly oxygenated triterpenoids. Expression and molecular docking analyses suggest involvement of specific members of CYP450 family in secondary modifications for the biosynthesis of bioactive triterpenoids. This study generated rich genomic resource and identified genes involved in biosynthesis of important molecules, which will aid in the advancement of tools for functional genomics and elucidation of the biosynthesis of triterpenoid from this important tree