850 research outputs found

    Polarization-rotation resonances with subnatural widths using a control laser

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    We demonstrate extremely narrow resonances for polarization rotation in an atomic vapor. The resonances are created using a strong control laser on the same transition, which polarizes the atoms due to optical pumping among the magnetic sublevels. As the power in the control laser is increased, successively higher-order nested polarization rotation resonances are created, with progressively narrower linewidths. We study these resonances in the D2D_2 line of Rb in a room-temperature vapor cell, and demonstrate a width of 0.14Γ0.14 \, \Gamma for the third-order rotation. The explanation based on a simplified Λ\LambdaV-type level structure is borne out by a density-matrix analysis of the system. The dispersive lineshape and subnatural width of the resonance lends itself naturally to applications such as laser locking to atomic transitions and precision measurements.Comment: 5 pages, 6 figure

    Pattern of neoplastic and non-neoplastic lesions of ovary: a five-year study in a tertiary care centre of rural india

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    Background: Most common ovarian lesions include benign non-neoplastic lesions including functional cysts and neoplastic lesions. While among cancers of female genital tract, the incidence of ovarian cancer ranks below only carcinoma of cervix and endometrium. The aim of this study was to observe and evaluate the frequency and morphological pattern of different ovarian pathologies encountered in this tertiary care centre of rural India.Methods: This was a retrospective five years observational study (2012-16) and conducted at Department of Pathology of UPUMS, Saifai. The study material included 264 histopathology specimens received in our department.Results: Total 264 cases of ovarian pathologies were studied, in which 147 cases were non-neoplastic while remaining 117 cases were neoplastic. The most common non-neoplastic lesion was follicular cyst (51.7%), followed by corpus luteal cyst (30.61%), endometriosis (15.64%). Among 117 neoplastic cases, 87 cases (74.35%) were benign, 5 cases (4.27%) were borderline tumours and 25 cases (21.36%) were diagnosed malignant. Serous cystadenoma was most common benign tumour with 53 cases (45.29%) followed by 20 cases (17.09%) of dermoid cyst and 12 cases (10.25%) of mucinous cystadenoma. While in malignant tumours, serous adenocarcinoma were most common (4.27%) followed by mucinous adenocarcinoma (2.56%).Conclusions: In our study, non-neoplastic ovarian lesions were more commonly seen than neoplastic lesions. Surface epithelial tumours were most common histologic type in all age groups. While serous adenocarcinoma was most common ovarian malignancy seen. Both non-neoplastic as well as neoplastic lesions of ovary often present with similar clinical and radiological features. So histopathological study is essential to diagnose ovarian tumours.

    Heat shock factor binding in Alu repeats expands its involvement in stress through an antisense mechanism

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    Background: Alu RNAs are present at elevated levels in stress conditions and, consequently, Alu repeats are increasingly being associated with the physiological stress response. Alu repeats are known to harbor transcription factor binding sites that modulate RNA pol II transcription and Alu RNAs act as transcriptional co-repressors through pol II binding in the promoter regions of heat shock responsive genes. An observation of a putative heat shock factor (HSF) binding site in Alu led us to explore whether, through HSF binding, these elements could further contribute to the heat shock response repertoire. Results: Alu density was significantly enriched in transcripts that are down-regulated following heat shock recovery in HeLa cells. ChIP analysis confirmed HSF binding to a consensus motif exhibiting positional conservation across various Alu subfamilies, and reporter constructs demonstrated a sequence-specific two-fold induction of these sites in response to heat shock. These motifs were over-represented in the genic regions of down-regulated transcripts in antisense oriented Alus. Affymetrix Exon arrays detected antisense signals in a significant fraction of the down-regulated transcripts, 50% of which harbored HSF sites within 5 kb. siRNA knockdown of the selected antisense transcripts led to the over-expression, following heat shock, of their corresponding down-regulated transcripts. The antisense transcripts were significantly enriched in processes related to RNA pol III transcription and the TFIIIC complex. Conclusions: We demonstrate a non-random presence of Alu repeats harboring HSF sites in heat shock responsive transcripts. This presence underlies an antisense-mediated mechanism that represents a novel component of Alu and HSF involvement in the heat shock response

    Alu-miRNA interactions modulate transcript isoform diversity in stress response and reveal signatures of positive selection

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    Primate-specific Alus harbor different regulatory features, including miRNA targets. In this study, we provide evidence for miRNA-mediated modulation of transcript isoform levels during heat-shock response through exaptation of Alu-miRNA sites in mature mRNA. We performed genome-wide expression profiling coupled with functional validation of miRNA target sites within exonized Alus, and analyzed conservation of these targets across primates. We observed that two miRNAs (miR-15a-3p and miR-302d-3p) elevated in stress response, target RAD1, GTSE1, NR2C1, FKBP9 and UBE2I exclusively within Alu. These genes map onto the p53 regulatory network. Ectopic overexpression of miR-15a-3p downregulates GTSE1 and RAD1 at the protein level and enhances cell survival. This Alu-mediated fine-tuning seems to be unique to humans as evident from the absence of orthologous sites in other primate lineages. We further analyzed signatures of selection on Alu-miRNA targets in the genome, using 1000 Genomes Phase-I data. We found that 198 out of 3177 Alu-exonized genes exhibit signatures of selection within Alu-miRNA sites, with 60 of them containing SNPs supported by multiple evidences (global-FST > 0.3, pair-wise-FST > 0.5, Fay-Wu’s H<−20, iHS> 2.0, high ΔDAF) and implicated in p53 network. We propose that by affecting multiple genes, Alu-miRNA interactions have the potential to facilitate population-level adaptations in response to environmental challenges

    Estimation and comparison of thrombocyte count by peripheral blood smear method and automated method in women with pregnancy

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    Background: Thrombocyte is important and very essential component of blood and have significant role in maintenance of hemostasis. Thrombocyte count is an important investigation done in various acquired and congenital coagulable states which include conditions like pregnancy. Thrombocyte count is routinely done by automated hematology analyzer method. The automated hematology analyzer counters are not usually available at all centres especially in peripheral and rural side though thrombocytes can also be assessed from the peripheral blood smears, which can be easily and precisely done at any set up. Aim and objective of this study was to compare the thrombocyte estimation by peripheral blood smear method and automated hematology analyzer in pregnant women.Methods: Thrombocyte estimation was done from samples taken from 120 normal pregnant women between December 2018 to March 2019, where samples were Ethylene Diamine Tetra Acetic acid (EDTA) anticoagulated. Thrombocyte was counted manually using PBS (Leishman stain) and hematology analyzer (Sysmex XN1000 series). Thrombocyte counts were expressed in Mean and standard Deviation. Statistical analysis was done by student’s t test using MS excel and SPSS version 17.Results: Thrombocyte count by PBS have mean value of 2.04 lacs/mm3 with standard deviation of 0.56 lacs/mm3 and by automated method have mean value of 1.89 lacs/mm3 and standard deviation of 0.71 lacs/mm3 with p value 0.010. Thus, there was no statistically significant difference found between two methods.Conclusions: Estimation of thrombocyte count on the basis of manual thrombocyte count is a reliable technique and can be used to validate automated thrombocyte counts. It can also be used in under resourced laboratories, where there are no automated counters of good precision available. In fact, all the tests showing abnormal thrombocyte counts must be reported only after cross examining on PBS

    An Alternative approach to Temporary Memory Management in Databases using Object Oriented Systems

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    Abstract Regardless of the supremacy of relational database management systems (RDBMS) in the databases, object-oriented database management systems (OODBMS) continue to play crucial role in the management of data. Generally, the complex data are often found in telecommunications, business, engineering and web based applications. The most common approach of accessing such data is navigation. However, the approach of navigational access of data has the potential of generating excessive disk IO because objects in the path of navigation may be placed in different disk pages. Excessive disk IO is becoming increasingly undesirable because disk IO performance improves at only 5-8% per year whereas CPU performance doubles approximately every 18 months. Thus disk IO is likely to be a bottleneck in an increasing number of OODB applications. This paper focuses on reducing disk IO effects to improve OODBMS performance. In database environment effective buffer management of the main memory is the key in increasing efficiency through reducing the disk IO bottleneck in OODBMSs. There has been much existing work, namely in the areas of: static clustering; dynamic clustering; buffer replacement; and pre-fetching. All of these techniques can be used together in a complimentary manner. Most existing research has focused on finding the best solution for each area with little regard on how solutions from the different areas affect each other. We believe synergy exists between the areas, and that exploiting the synergy leads to the best overall solution. This paper focuses on exploring whether synergistic techniques are both feasible to implement and outperform their non-synergistic counterparts
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