574 research outputs found

    Fractional Quantum Hall Effect States as Exact Ground States

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    We construct many particle Hamiltonians for which the Laughlin and Jain wavefunctions are exact ground states. The Hamiltonians involve fermions in a magnetic field and with inter-particle interactions. For the Laughlin wave-functions,the interactions involve two- and three-body correlations similar to the Chern-Simons interactions, whereas for the projected Jain wave-functions, N-body interactions (which cannot be explicitly written down in general) are involved.Comment: Several changes, particularly in interpretatio

    Exactly Solvable Fermionic N-chain Models

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    Motivated by the problem of N coupled Hubbard chains, we investigate a generalisation of the Schulz-Shastry model containing two species of one-dimensional fermions interacting via a gauge field that depends on the positions of all the particles of the other species. The exact many body ground state of the model can be easily obtained through a unitary transformation of the model. The correlation functions are Luttinger-like - i.e., they decay through power laws with non-integer exponents. Through the interaction dependent correlation functions of the two-particle operators, we identify the relevant perturbations and hence, possible instabilities.Comment: 10 pages, 1 eps figure, Late

    Transport in Luttinger Liquids

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    We give a brief introduction to Luttinger liquids and to the phenomena of electronic transport or conductance in quantum wires. We explain why the subject of transport in Luttinger liquids is relevant and fascinating and review some important results on tunneling through barriers in a one-dimensional quantum wire and the phenomena of persistent currents in mesoscopic rings. We give a brief description of our own work on transport through doubly-crossed Luttinger liquids and transport in the Schulz-Shastry exactly solvable Luttinger-like model.Comment: Latex file, 15 pages, four eps figure

    MICROALBUMINURIA – A RISK FACTOR FOR CARDIOVASCULAR DISEASE IN DIABETIC POSTMENOPAUSAL WOMEN

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    Introduction: Diabetes is one of the common metabolic disorders. Microalbuminuria (MA) is usually estimated in diabetic patients and patients withrisk of renal problems.Objective: Our aim is to study the occurrence of MA in both apparently normal and diabetic postmenopausal women and to find out the relationshipbetween MA and cardiovascular risk factors.Methods: This study was conducted in a tertiary care hospital, Puducherry, for a period of 6 months. Serum and urine samples were taken from 50apparently normal postmenopausal women and 51 diabetic women and compared. Serum was analyzed for urea, creatinine, uric acid levels, lipidprofile, and the urine sample was estimated for microalbumin, creatinine levels. Urine albumin creatinine ratio and glomerular filtration rate werecalculated using standard methods.Results: About 47% of diabetic women and 46% of apparently normal postmenopausal women had MA. Total cholesterol (TC), triglycerides (TGL),and very-low-density lipoprotein (VLDL) values were higher in diabetic women when compared to the normal women. MA positive subjects hadrelatively higher TC, low-density lipoprotein, TGL, and VLDL levels when compared to MA negative subjects.Conclusion: The occurrence of MA in normal postmenopausal women is almost similar to that of diabetic women. This suggests the importance ofscreening of MA even in normal postmenopausal women. In addition, abnormal lipid profile in diabetic patients favors the need for regular screeningof MA and lipid profile in all diabetic patients.Keywords: Microalbuminuria, Diabetes, Postmenopausal women, Lipid profile, Renal parameters

    Trivially extendable graphs

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    Let G be a simple graph. Let k be a positive integer. G is said to be k-extendable if every independent set of cardinality k is contained in a maximum independent set of G. G is said to be trivially extendable if G is not k-extendable for 1 ≤ k ≤ (β0(G) − 1). A well covered graph is one in which every maximal independent set is maximum. Study of k-extendable graphs has been made in [7,8,9]. In this paper a study of trivially extendable graphs is made. Characterization of graphs with β0(G) = (n − 3) and which is trivially extendable has been done. Similarly graphs with β0(G) = (n − 2) is also studied for trivial extensibility.Publisher's Versio

    Role of Cell Block in Ascetic Fluid Cytology in the Evaluation and Grading of Malignancy

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    BACK GROUND : Cell block technique is one of the oldest method, which is used for the evaluation of body cavity fluids. An effective method of cell block preparation was used which utilises 10% formalin as a fixative. And cell blocks were prepared by plasma thromboplastin method. This method usually increases the cellularity, gives better morphological details and helps in improving the sensitivity of the diagnosis and grading of malignancy. Multiple sections can obtained by the cell block method for special stains and immunohistochemistry studies. AIMS : Preparing of cell blocks of ascetic fluid in suspicious or confirmed cases of malignancy. Evaluation and grading of visceral malignancy in cell block by applying Ki 67 Marker by MIB index scoring system. METHOD : Cell block prepared by plasma thromboplastin method. 5 ml of sample were subjected to fixation for one hour by mixing it with 5 ml of 10% formalin. Centrifuged at 2500 rpm for 15 mnts. The sediment mixed with 2 drops of pooled plasma. Four drops of thromboplastin was added, tube allow to stand for 5-10mnts. The resultant clot was sent for processing. Stain with H&E. Evaluation and grading was done. RESULTS : Out of 100 samples of ascetic fluid 14 cases were malignant. And grading of malignancy done by applying ki67 marker by MIB index scoring system. CONCLUSION : Cell block method is useful to detect and grading of malignancy by applying immunohistochemistry

    Classifying Dominant Congested Path Using Correlation Factors

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    Traffic classification has wide applications in network management, from security monitoring to quality of service measurements. Recent research tends to apply machine learning techniques to flow statistical feature based classification methods. The nearest neighbor (NN)-based method has exhibited superior classification performance. It also has several important advantages, such as no requirements of training procedure, no risk of overfitting of parameters, and naturally being able to handle a huge number of classes. However, the performance of NN classifier can be severely affected if the size of training data is small. In this paper, we propose a novel nonparametric approach for traffic classification, which can improve the classification performance effectively by incorporating correlated information into the classification process. We analyze the new classification approach and its performance benefit from both theoretical and empirical perspectives. A large number of experiments are carried out on two real-world traffic data sets to validate the proposed approach. The results show the traffic classification performance can be improved significantly even under the extreme difficult circumstance of very few training samples

    A Comparative Evaluation of Efficacy of Phytic Acid, Etidronic Acid and EDTA on Smear Layer Removal and Dentin Erosion at Different Time Intervals Using Scanning Electron Microscope: An In Vitro study

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    AIM : The purpose of this in vitro study was to compare the smear layer removal efficacy and dentin erosion of three different irrigating solutions at different time intervals of the root canal under Scanning Electron Microscopy. MATERIALS AND METHODS : One hundred extracted human single straight rooted maxillary central incisors were taken and decoronated to standardize the canal length of 16 mm. They were instrumented by ProTaper NEXT rotary system to an apical preparation of file size X5. Prepared teeth were irrigated with 3ml of 3% NaOCl for 5min followed by final rinse of 2ml of 1% phytic acid (Group I), 18% Etidronic acid (Group II) and 17% EDTA (Group III) at 5min, 3min and 1min. The canals of teeth in Control (Group IV) did not receive the final irrigation. The teeth were sectioned longitudinally and prepared for an SEM evaluation. The dentinal wall of cervical, middle and apical thirds was graded according to the amount of smear layer remaining and dentin erosion on the root canal walls. The results were analysed using the Kruskal–Wallis and Mann Whitney U tests with significance set at P < 0.05. RESULTS : Intergroup comparison showed statistically no significant difference (p=1.000) in the smear layer removal efficacy of irrigants tested at 5min, 3min and 1min except for Etidronic acid(Group II) at 1min (p=.000). Control (Group IV) showed statistically high significant difference (p=.000) than other groups. Apical region of all groups showed statistically high significant difference (p=.000) than cervical and middle region. Intergroup comparison of dentin erosion showed EDTA (Group III) had high erosion values (p=.000) than other groups which are statistically significant. Phytic acid (Group I) showed less erosion values (p=.000) than other groups which are highly significantr. CONCLUSION : Phytic acid shows effective smear layer removal with less erosion of the root canal wall. Increasing the duration of irrigation does not improve the smear layer efficacy of irrigants except for Etidronic acid (Group II) but all groups showed more erosion at increased irrigation time. All the groups did not completely remove the smear layer at the apical region
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