697 research outputs found

    Efficient dynamical downscaling of general circulation models using continuous data assimilation

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    Continuous data assimilation (CDA) is successfully implemented for the first time for efficient dynamical downscaling of a global atmospheric reanalysis. A comparison of the performance of CDA with the standard grid and spectral nudging techniques for representing long- and short-scale features in the downscaled fields using the Weather Research and Forecast (WRF) model is further presented and analyzed. The WRF model is configured at 25km horizontal resolution and is driven by 250km initial and boundary conditions from NCEP/NCAR reanalysis fields. Downscaling experiments are performed over a one-month period in January, 2016. The similarity metric is used to evaluate the performance of the downscaling methods for large and small scales. Similarity results are compared for the outputs of the WRF model with different downscaling techniques, NCEP reanalysis, and Final Analysis. Both spectral nudging and CDA describe better the small-scale features compared to grid nudging. The choice of the wave number is critical in spectral nudging; increasing the number of retained frequencies generally produced better small-scale features, but only up to a certain threshold after which its solution gradually became closer to grid nudging. CDA maintains the balance of the large- and small-scale features similar to that of the best simulation achieved by the best spectral nudging configuration, without the need of a spectral decomposition. The different downscaled atmospheric variables, including rainfall distribution, with CDA is most consistent with the observations. The Brier skill score values further indicate that the added value of CDA is distributed over the entire model domain. The overall results clearly suggest that CDA provides an efficient new approach for dynamical downscaling by maintaining better balance between the global model and the downscaled fields

    Architecture for Fault Tolerance in Mobile Cloud Computing using Disease Resistance Approach

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    The mobile cloud computing (MCC) is one of the emerging fields in the distributed computing. MCC is an integration of both mobile computing and cloud computing. The limitations of the mobile devices are storage, battery and processing proficiency.These sensitive characteristics of mobile devices can be effectively handled with the introduction of cloud computing. The increasing functionality of the cloud and complexity of the applications causes resource failures in the cloud computing and it reduces the overall performance of the MCC environment. On the other hand, the existing approaches for resource scheduling in MCC proposed several architectures and they are only concentrated on the allocation of resources. The existing architectures are lack of fault tolerance mechanism to handle the faulty resources. To overcome the issues stated above, this paper proposes architecture for fault tolerance in MCC using Disease Resistance approach (DRFT). The main aim of the DRFT approach is to effectively handle the faultyVMs in the MCC. This DRFT approach utilizes the human disease resistance mechanism which is used as materials and methods in the proposed model. The DRFT is capable of identifying the faulty virtual machines and reschedules the tasks to the identified suitable virtual machines. This procedure ultimately leads to minimization of makespan value and it improves the overall performance of the scheduling process. To validate the effectiveness of the proposed approach, a series of simulations has been carried out using CloudSim simulator. The performance of the proposed DRFT approach is compared with the Dynamic group based fault tolerance approach (DGFT-approach). The makespan value of DRFT is reduced to 7% and the performance of DRFT is increased when compare to the DGFT approach. The experimental results show the effectiveness of the proposed approach

    Antihepatotoxic effect of Elephantopus scaber L. on carbon tetrachloride-induced hepatotoxicity in rats

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    Elephantopus scaber was used in folk medicine in several countries to treat different diseases. Liver diseases are major World wise health Problems. The Present aim of the study was evaluate The Antihepatotoxic effects of different fractions of Elephantopus scaber against Carbon tetrachloride (CCl4) induced hepatic damage in Rats. All the fractions were given orally in different doses (125mg/kg, 250mg/kg, 500mg/kg). The Antihepatotoxic effect was assessed by measuring serum parameters like  aspertate transaminase (AST), alanine transaminase (ALT), Alkaline Phospatase (ALP) and total bilurubin.  All the fractions of Elephantopus scaber showed Antihepatotoxic effect.The ethanol fraction was shows significant percentage protection than compared to other fractions. Therefore, our study supports the isolation and use of active constituents from Ethanol fraction of Elephantopus scaber in treating of liver disease

    The minimum mean monopoly energy of a graph

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    The motivation for the study of the graph energy comes from chemistry, where the research on the so-called total pi - electron energy can be traced back until the 1930s. This graph invariant is very closely connected to a chemical quantity known as the total pi - electron energy of conjugated hydro carbon molecules. In recent times analogous energies are being considered, based on Eigen values of a variety of other graph matrices. In 1978, I.Gutman [1] defined energy mathematically for all graphs. Energy of graphs has many mathematical properties which are being investigated. The ordinary energy of an undirected simple finite graph G is defined as the sum of the absolute values of the Eigen values of its associated matrix. i.e. if mu(1), mu(2), ..., mu(n) are the Eigen values of adjacency matrix A(G), then energy of graph is Sigma(G) = Sigma(n)(i=1) vertical bar mu(i)vertical bar Laura Buggy, Amalia Culiuc, Katelyn Mccall and Duyguyen [9] introduced the more general M-energy or Mean Energy of G is then defined as E-M (G) = Sigma(n)(i=1)vertical bar mu(i) - (mu) over bar vertical bar, where (mu) over bar vertical bar is the average of mu(1), mu(2), ..., mu(n). A subset M subset of V (G), in a graph G (V, E), is called a monopoly set of G if every vertex v is an element of (V - M) has at least d(v)/2 neighbors in M. The minimum cardinality of a monopoly set among all monopoly sets in G is called the monopoly size of G, denoted by mo(G) Ahmed Mohammed Naji and N.D.Soner [7] introduced minimum monopoly energy E-MM [G] of a graph G. In this paper we are introducing the minimum mean monopoly energy, denoted by E-MM(M) (G), of a graph G and computed minimum monopoly energies of some standard graphs. Upper and lower bounds for E-MM(M) (G)are also established.Publisher's Versio

    EVALUATION OF EFFICACY OF OOSHAKADI LEKHANA BASTI IN HYPERLIPIDAEMIA - A SINGLE BLINDED RANDOMIZED CONTROLLED STUDY

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    Disorders of lipid metabolism and obesity are reported by 30% to 40% with increased prevalence. These conditions are co-related with Medo-pradoshajavikara - a condition leading for excess formation of Meda (lipids) directly from Amarasa Dhatu (improperly formed chyle) and travel all over body through blood circulation. This stage is compared to hyperlipidaemia where it is defined as excess circulation of lipids in blood. The present study highlights the efficacy of Ooshakadi Lekhana Basti (type of therapeutic enema) processed by Ooshakadigana Dravyas (alkaline substances). Ooshaka (alkaline sand) was special drug and used almost for first time which is synonymously known as Kshara Mrittika. A single blinded controlled study has been conducted on 45 patients randomized in to three groups each containing 15 patients. The control drug was atrovastin. Average mean reduction of lipids were found statistically significant (p<0.05) in the experimental groups over control group in all types of lipids except HDL which has presented increase pattern. Hence the study establishes the efficacy of Ooshakadi Lekhana Basti in hyperlipidaemia of obese and non-obese patients

    Case series of clinical study and surgical management of atlanto axial dislocation our institute experience

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    Background: Atlantoaxial dislocation refers to a loss of stability between the atlas and axis (C1-C2), resulting in loss of normal articulation. Cervical spine C1-C2 motion segment is the most technically challenging.Methods: This is a prospective and retrospective Study which included 34 patients admitted in King George hospital, Andhra medical college, Visakhapatnam over the past two years (January 2014- January 2016) with AAD.Results: The age of the patients ranged from 3 to 60 years with mean age being 37.67 years. Commonest presenting sign is local tenderness at the back of upper cervical region in 91.17%. Most common procedure done was single sitting trans oral odontoid decompression with posterior occipito cervical fusion with occipital plate and C2, C4 polyaxial screws and lateral mass rods in 18 cases out of 34. The next common procedure performed was C1 lateral mass and C2 pars screw fixation 8 out of 34.Conclusions: Trans oral odentoidectomy and posterior ocipito cervical fusion is ideal and still holds good for irreducible AAD with  ventral compressive pathology

    Institutional experience of tuberculosis of craniovertebral junction

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    Background: Craniovertebral junction tuberculosis (CVJ-TB) is a rare entity occurring in only 0.3 to 1% of tuberculous spondylitis. It causes severe instability and neurological deficits. Present study includes 16 cases of CVJ tuberculosis with neck pain and progressive quadriparesis. Radiological evaluation showed wide spread disease around clivus, C1, C2, C3 with extensive bony destruction, cord compression, basilar invagination and atlantoaxial dislocation.Methods: The study included all the cases admitted with cv junction tuberculosis in neurosurgery ward in King George hospital, Visakhapatnam during a period of three years from 2014 to 2016. Four cases were managed conservatively and four cases were treated by only posterior occipitocervical fusion. We performed two stage operation in single sitting i.e. transoral decompression and posterior occipitocervical fusion in 12 cases. The pathological findings confirmed tuberculosis.Results: Postoperatively all the patients had decreased neck pain and two third of the patients (10 of 16 patients) had improvement in motor power.Conclusions: In the available literature, the treatment options offered for cvj-tb have ranged from a purely conservative approach to radical surgery without well-defined guidelines. In this study, we followed a radical approach as the patients included in our study presented with extensive TB cv junction. So, we recommend radical surgery for extensive TB of cv junction
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