2,801 research outputs found
Wave packet dynamics of the matter wave field of a Bose-Einstein condensate
We show in the framework of a tractable model that revivals and fractional
revivals of wave packets afford clear signatures of the extent of departure
from coherence and from Poisson statistics of the matter wave field in a
Bose-Einstein condensate, or of a suitably chosen initial state of the
radiation field propagating in a Kerr-like medium.Comment: 10 pages, 4 figures, RevTeX
A study of migraine cases in a tertiary care hospital neurology outpatient department: demography, sub classification and clinical features
Background: Recurrent headache disorders impose a substantial burden on headache sufferers, family and society. In India, 15 to 20% of people suffer from migraine with an adult female: male ratio of 2:1. This study has been done with an aim at documenting the different types of migraine, their clinical presentations among patients presented to the Headache clinic, Neurology outpatient Department, Government Rajaji Hospital, Madurai during a one year period.Methods: The patients registered at Headache clinic, Neurology outpatient Department, Government Rajaji Hospital, Madurai during one year period between the March 2009 and February 2010 with the diagnosis of migraine as per International Headache Society 2004 criteria were taken for this study. The clinical material was collected from the records and by patient interviews with a detailed pre-prepared proforma. The various parameters of the patients were compared, classified and analysed with specific reference to national and international studies.Results: Migraine is the commonest type of headache comprising of about 76% of total cases of headache. Migraine without aura (48%) was more common than migraine with aura (32%). Female preponderance was noticed in all subtypes of migraine, age of onset being in 2nd and 3rd decade for majority of the subgroups of migraine, with positive family history in 45% of cases, with predominant unilateral in presentation and temporal in location, lasting for 12 to 24 hours in majority of cases.Conclusions: Migraine is the commonest type of headache in patients observed in this study. Among subtypes migraine without aura is the commonest. Second and third decade is the commonest age group of onsets
A deterministic width function model
International audienceUse of a deterministic fractal-multifractal (FM) geometric method to model width functions of natural river networks, as derived distributions of simple multifractal measures via fractal interpolating functions, is reported. It is first demonstrated that the FM procedure may be used to simulate natural width functions, preserving their most relevant features like their overall shape and texture and their observed power-law scaling on their power spectra. It is then shown, via two natural river networks (Racoon and Brushy creeks in the United States), that the FM approach may also be used to closely approximate existing width functions
Human Cytomegalovirus glycoprotein UL16 causes intracellular sequestration of NKG2D ligands, protecting against NK cell cytotoxicity.
The activating receptor, NKG2D, is expressed on a variety of immune effector cells and recognizes divergent families of major histocompatibility complex (MHC) class I-related ligands, including the MIC and ULBP proteins. Infection, stress, or transformation can induce NKG2D ligand expression, resulting in effector cell activation and killing of the ligand-expressing target cell. The human cytomegalovirus (HCMV) membrane glycoprotein, UL16, binds to three of the five known ligands for human NKG2D. UL16 is retained in the endoplasmic reticulum and cis-Golgi apparatus of cells and causes MICB to be similarly retained and stabilized within cells. Coexpression of UL16 markedly reduces cell surface levels of MICB, ULBP1, and ULBP2, and decreases susceptibility to natural killer cell-mediated cytotoxicity. Domain swapping experiments demonstrate that the transmembrane and cytoplasmic domains of UL16 are important for intracellular retention of UL16, whereas the ectodomain of UL16 participates in down-regulation of NKG2D ligands. The intracellular sequestration of NKG2D ligands by UL16 represents a novel HCMV immune evasion mechanism to add to the well-documented viral strategies directed against antigen presentation by classical MHC molecules
Modeling geophysical complexity: a case for geometric determinism
International audienceIt has been customary in the last few decades to employ stochastic models to represent complex data sets encountered in geophysics, particularly in hydrology. This article reviews a deterministic geometric procedure to data modeling, one that represents whole data sets as derived distributions of simple multifractal measures via fractal functions. It is shown how such a procedure may lead to faithful holistic representations of existing geophysical data sets that, while complementing existing representations via stochastic methods, may also provide a compact language for geophysical complexity. The implications of these ideas, both scientific and philosophical, are stressed
Editorial: Triggers of behavioural change in an evolving world
This special issue collects six papers that were presented at the 2015 IATBR conference, which took place in Windsor, UK. It also includes a resource paper from one of the conference workshops. All regular papers were selected by the guest editors and subsequently peerreviewed in line with the European Journal of Transport and Infrastructure Research standards. Ultimately, 60% of submitted papers were accepted for publication
Process modelling of a PVC production plant
This paper presents the modelling of a Polyvinyl Chloride (PVC) resins manufacturing process with batch process simulator, SuperPro Designer V6.0. The simulation model has been developed based on the operating condition of a local PVC manufacturing plant. As the polymerisation process is carried out in batch operation mode, efforts have been made to document the scheduling details of each unit operation and results are presented in the Gantt chart. Cycle time for a complete polymerisation process is determined to be 14.28 hours. The model also reveals that approximately 17 batches of polymerisation reaction can be processed per day, which tallies the real operation of the PVC manufacturing plant
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