Determination of the chromospheric quiet network element area index and its variation during 2008-2011

Generally it has been considered that the plages and sunspots are the main contributors to the solar irradiance. There are small scale structures on the sun with intermediate magnetic fields that could also contribute to the solar irradiance. It has not yet been quantified how much of these small scale structures contribute to the solar irradiance and how much it varies over the solar cycle. In this paper, we used Ca II K images obtained from the telescope installed at Kodaikanal observatory. We report a method to separate the network elements from the background structure and plage regions. We compute the changes in the network element area index during the minimum phase of solar cycle and part of the ascending phase of cycle 24. The measured area occupied by the network elements is about 30% and plages less than 1% of the solar disk during the observation period from February 2008-2011. During the extended period of minimum activity it is observed that the network element area index decreases by about 7% compared to the area occupied by the network elements in 2008. A long term study of network element area index is required to understand the variations over the solar cycle.Comment: 12 pages, 9 Figures, Accepted for publication in RA

Clinical study of pathological myopia

HISTORY: Myopia is well known even since ancient period. The word Myopia is a Greek word, which means “to shut” or “to close the eye”. The original meaning of the word Myopia was meant to describe the condition where the patient attempts to see clearly by partially shutting or closing their eyes. AIM OF THE STUDY: 1. To analyse the ocular parameters associated with degenerative myopia 2. To study the corneal thickness, axial length and Refractive parameters with reference pathological myopia 3. To assess the ocular associations of pathological myopia 4. To assess the visual status associated with pathological myopia 5. To determine the visual disability and the major causes of vision loss in pathological myopia 6. To categorise and assess the percentage of visual disability PURPOSE OF STUDY: Degenerative myopia is common in India and is a major cause for visual disability According to NPCB-WHO SURVEY 1980 uncorrected refractive errors, particularly pathological myopia, accounts for 7.355 of all causes of bilateral blindness which is only second to cataract among all leading causes of blindness. In Tamilnadu the percentage goes to 21.5 % .also in the survey for causes of low vision in India, refractive errors accounts for 18.875 and is the second leading cause for low vision. While prevention is not possible at least blindness from pathological myopia may be prevented, at least to some extent. this is possible by early detection of the most common cause of vision loss the choroidal neovascularisation by appropriate investigation and treating them. also early detection of peripheral retinal degeneration And prophylactic laser treatment would be helpful. Vision loss in myopes is not only because of their high refractive error but also due to the associated conditions with it. One among them which gains importance is open angle glaucoma which is easily missed because of the falsely recorded visual acuity and the misleaded optic disc apperaence.prompt recognition of these associated conditions and addressing them will be greatly helpful to them in retaining their vision. INCLUSION CRITERIA: 1. All patients with refractive error greater than – 6 dioptre spherical equivalents in one or both eyes were included in the study. 2. Patients with age 10 – 40 who filled the above criteria were included in the study. 3. Both sexes, males and females ,were included in the study 4. Patients were included irrespective of the visual acuity EXCLUSION CRITERIA: 1. Patients with previous intraocular surgery were excluded from the study. 2. Patients aged less than 10 years and greater than 40 years were excluded from the study 3. Patients wearing contact lenses were excluded from the study. MATERIALS AND METHODS: This is a retrospective study done in eye department, Thanjavur medical college, Thanjavur from June 2011 to October 2012. A total of fifty patients attending outpatient department were selected. Informed consent was obtained from all the patients. All patients underwent a complete ocular examination including 1. Visual acuity measurement- by snellens visual acuity chart 2. Anterior segment examination by torch light followed by slit lamp examination. 3. Corneal curvature measurement and retinoscopy by automated refractometer. 4. Intraocular measurement by goldmann applanation tonometer after instillation of 4 % lignocaine and staining with sterile fluorescin strips. 5. Central corneal thickness measurement by pachymeter 6. Axial length measurement by ultrasound A scan 7. Gonioscopy by Goldman single mirror 8. Dilated fundus examination using direct, bio microscopic examination with + 78 dioptre lens, indirect method. 9. In selective cases, ultrasound –B scan and was also done. 10 .In selective cases visual field examination was done on another day with Octopus automated perimeter. All the measurements and examination were done by single trained person to avoid inter observer variations. SUMMARY AND CONCLUSION: The literature on degenerative myopia was reviewed. Materials and methods employed are stated. In the study there was 30% association of family history in pathological myopia. The ocular parameters were greatly altered in pathological myopia. The axial length is increased and their increase is proportional to the refractive error and vision loss in majority of cases. The central corneal thickness is reduced to less than 525 microns in most of the patients which is very important finding because it may results in the false recording of intraocular pressure. The common ocular associations found in pathological myopia are 1) open angle glaucoma, 2) retinitis pigmentosa , 3) keratoconus and 4)albinism. The common cause of vision loss associated with pathological myopia were choroidal neovascularistion, and retinal detachment. The associated conditions which were responsible for vision loss were Optic atrophy due to glaucoma and retinitis pigmentosa. Regarding visual disability in pathological myopia 50% of all myopic patients suffered from some form of visual disability. There is an increased vulnerability for trauma in these patients due to prominent globe .so necessary preventive measures should be taken. Myopia related visual impairment may affect the productivity, mobility, quality of life and activities of daily living of the individuals. Potentially blinding-myopia related pathologies are often irreversible in nature, especially if diagnosed late. So early recognition of the coexisting conditions and complications, and their management may prevent the degenerative myopic patients from becoming essentially blind

A Comparison of Wavelet, Curvelet and Contourlet based Texture Classification Algorithms for Characterization of Bone Quality in Dental CT

Abstract: The objective of this paper is to design and implement classifier framework to assist the surgeon for preoperative assessment of bone quality from Dental Computed Tomography images. This article focuses on comparing the discriminating power of several multiresolution texture analysis methods to evaluate the quality of the bone based on the texture variations of the images obtained from the implant site using wavelet, curvelet and contourlet.The approach consists of three steps: automatic extraction of the most discriminative texture features from regions of interest, creation of a classifier that automatically grades the bone depends on the quality. Since this is medical domain, the validation against the human experts is carried out. The results indicate that the combination of the statistical and multiscale representation of the bone image gives adequate information to classify the different bone groups compared to gray level features at single scale

A novel algorithm with IM-LSI index for incremental maintenance of materialized view

The ability to afford decision makers with both accurate and timely consolidated information as well as rapid query response times is the fundamental requirement for the success of a Data Warehouse. To provide fast access, a data warehouse stores materialized views of the sources of its data. As a result, a data warehouse needs to be maintained to keep its contents consistent with the contents of its data sources. Incremental maintenance is generally regarded as a more efficient way to maintain materialized views in a data warehouse The view has to be maintained to reflect the updates done against the base relations stored at the various distributed data sources. The proposed approach contains two modules namely, materialized view selection(MVS) and maintenance of materialized view. (MMV). In recent times, several algorithms have been proposed for keeping the views up-to-date in response to the changes in the source data. Therefore, we present an improved algorithm for MVS and MMV using IM-LSI(Itemset Mining using Latent Semantic Index) algorithm. selection of views to materialize using the IM(Itemset Mining) algorithm method to overcome the problem resulting from conventional view selection algorithms and then we consider the maintenance of materialized views using LSI. For the justification of the proposed algorithm, we reveal the experimental results in which both time and space costs better than conventional algorithms.Facultad de Informátic

Alterations in tumour suppressor gene p53 in human gliomas from Indian patients

Alterations in the tumour suppressor p53 gene are among the most common defects seen in a variety of human cancers. In order to study the significance of the p53 gene in the genesis and development of human glioma from Indian patients, we checked 44 untreated primary gliomas for mutations in exons 5-9 of the p53 gene by PCR-SSCP and DNA sequencing. Sequencing analysis revealed six missense mutations. The incidence of p53 mutations was 13.6% (6 of 44). All the six mutations were found to be located in the central core domain of p53, which carries the sequence-specific DNA-binding domain. These results suggest a rather low incidence but a definite involvement of p53 mutations in the gliomas of Indian patients

Application of the rainbow trout derived intestinal cell line (RTgutGC) for ecotoxicological studies: molecular and cellular responses following exposure to copper.

There is an acknowledged need for in vitro fish intestinal model to help understand dietary exposure to chemicals in the aquatic environment. The presence and use of such models is however largely restrictive due to technical difficulties in the culturing of enterocytes in general and the availability of appropriate established cell lines in particular. In this study, the rainbow trout (Oncorhynchus mykiss) intestinal derived cell line (RTgutGC) was used as a surrogate for the "gut sac" method. To facilitate comparison, RTgutGC cells were grown as monolayers (double-seeded) on permeable Transwell supports leading to a two-compartment intestinal model consisting of polarised epithelium. This two-compartment model divides the system into an upper apical (lumen) and a lower basolateral (portal blood) compartment. In our studies, these cells stained weakly for mucosubstances, expressed the tight junction protein ZO-1 in addition to E-cadherin and revealed the presence of polarised epithelium in addition to microvilli protrusions. The cells also revealed a comparable transepithelial electrical resistance (TEER) to the in vivo situation. Importantly, the cell line tolerated apical saline (1:1 ratio) thus mimicking the intact organ to allow assessment of uptake of compounds across the intestine. Following an exposure over 72 h, our study demonstrated that the RTgutGC cell line under sub-lethal concentrations of copper sulphate (Cu) and modified saline solutions demonstrated uptake of the metal with saturation levels comparable to short term ex situ gut sac preparations. Gene expression analysis revealed no significant influence of pH or time on mRNA expression levels of key stress related genes (i.e. CYP3A, GST, mtA, Pgp and SOD) in the Transwell model. However, significant positive correlations were found between all genes investigated suggesting a co-operative relationship amongst the genes studied. When the outlined characteristics of the cell line are combined with the division of compartments, the RTgutGC double seeded model represents a potential animal replacement model for ecotoxicological studies. Overall, this model could be used to study the effects and predict aquatic gastrointestinal permeability of metals and other environmentally relevant contaminants in a cost effective and high throughput manner

A Ten-microRNA Expression Signature Predicts Survival in Glioblastoma

Glioblastoma (GBM) is the most common and aggressive primary brain tumor with very poor patient median survival. To identify a microRNA (miRNA) expression signature that can predict GBM patient survival, we analyzed the miRNA expression data of GBM patients (n = 222) derived from The Cancer Genome Atlas (TCGA) dataset. We divided the patients randomly into training and testing sets with equal number in each group. We identified 10 significant miRNAs using Cox regression analysis on the training set and formulated a risk score based on the expression signature of these miRNAs that segregated the patients into high and low risk groups with significantly different survival times (hazard ratio [HR] = 2.4; 95% CI = 1.4–3.8; p<0.0001). Of these 10 miRNAs, 7 were found to be risky miRNAs and 3 were found to be protective. This signature was independently validated in the testing set (HR = 1.7; 95% CI = 1.1–2.8; p = 0.002). GBM patients with high risk scores had overall poor survival compared to the patients with low risk scores. Overall survival among the entire patient set was 35.0% at 2 years, 21.5% at 3 years, 18.5% at 4 years and 11.8% at 5 years in the low risk group, versus 11.0%, 5.5%, 0.0 and 0.0% respectively in the high risk group (HR = 2.0; 95% CI = 1.4–2.8; p<0.0001). Cox multivariate analysis with patient age as a covariate on the entire patient set identified risk score based on the 10 miRNA expression signature to be an independent predictor of patient survival (HR = 1.120; 95% CI = 1.04–1.20; p = 0.003). Thus we have identified a miRNA expression signature that can predict GBM patient survival. These findings may have implications in the understanding of gliomagenesis, development of targeted therapy and selection of high risk cancer patients for adjuvant therapy

The Effects of Apolipoprotein F Deficiency on High Density Lipoprotein Cholesterol Metabolism in Mice

Apolipoprotein F (apoF) is 29 kilodalton secreted sialoglycoprotein that resides on the HDL and LDL fractions of human plasma. Human ApoF is also known as Lipid Transfer Inhibitor protein (LTIP) based on its ability to inhibit cholesteryl ester transfer protein (CETP)-mediated transfer events between lipoproteins. In contrast to other apolipoproteins, ApoF is predicted to lack strong amphipathic alpha helices and its true physiological function remains unknown. We previously showed that overexpression of Apolipoprotein F in mice reduced HDL cholesterol levels by 20–25% by accelerating clearance from the circulation. In order to investigate the effect of physiological levels of ApoF expression on HDL cholesterol metabolism, we generated ApoF deficient mice. Unexpectedly, deletion of ApoF had no substantial impact on plasma lipid concentrations, HDL size, lipid or protein composition. Sex-specific differences were observed in hepatic cholesterol content as well as serum cholesterol efflux capacity. Female ApoF KO mice had increased liver cholesteryl ester content relative to wild type controls on a chow diet (KO: 3.4+/−0.9 mg/dl vs. WT: 1.2+/−0.3 mg/dl, p<0.05). No differences were observed in ABCG1-mediated cholesterol efflux capacity in either sex. Interestingly, ApoB-depleted serum from male KO mice was less effective at promoting ABCA1-mediated cholesterol efflux from J774 macrophages relative to WT controls