311 research outputs found

    Variations in the formation of the median nerve and its clinical correlation

    Get PDF
    Variations in the formation of the median nerve are of interest to anatomists, radiologists, and surgeons. These variations may be vulnerable to damage in surgical operations, but their knowledge also helps in the interpretation of a nervous compression having unexplained clinical symptoms. We studied the variation in the formation of the median nerve in 87 cadavers, i.e. 174 upper limbs of formalin preserved cadavers at the department of Anatomy, Subharti medical college. We observed an additional root taking part in the formation of the median nerve in 26.4% of upper limbs, unusual low formation of the median nerve in the arm in front of the brachial artery in 18.4% of upper limbs, and median nerve formation medial to the axillary artery in 10.3% of upper limbs. Knowledge of such anatomical variations is of interest to the anatomist and clinician alike. Surgeons who perform procedures involving neoplasm or trauma repair need to be aware of these variations

    Variant origin of superior polar artery and unusual hilar branching pattern of renal artery with clinical correlation

    Get PDF
    Classically, a single renal artery arising from the abdominal aorta supplies the respective kidney on each side. Near the hilum of the kidney each renal artery divides into anterior and posterior branchs, which in turn divide into segmental arteries supplying the different renal segments. A total of 84 formalin fixed cadavers (73 male and 11 female, 168 kidneys in total) constituted the material for the study. During routine abdominal dissection conducted for medical undergraduates, the kidneys and their arteries were explored and variations in morphological patterns of renal arteries were noted. We observed superior polar renal artery in 22.6% cases. Superior polar renal arteries had different sources of origin. In 10.7% of cases it came directly from the abdominal aorta as an accessory renal artery; in 5.4% of cases as a direct branch from the main renal artery; in 3.6% of cases from the superior hilar renal artery (from one of the duplicated renal arteries); and in 3.0% of cases from a segmental branch of the renal artery. We also observed unusual hilar branching patterns of renal arteries, which included a fork pattern in 11.3% of cases, ladder pattern in 7.7% of cases, net pattern in 5.9% of cases, and triplicate in 3.0% of cases. Understanding the anatomy of vascular variations of the kidney is essential for the clinician to be able to perform procedures such as renal transplantation, interventional radiological procedures, and renal vascular operations more safely and efficiently. (Folia Morphol 2011; 70, 1: 24-28

    Logarithmic asymptotics of the densities of SPDEs driven by spatially correlated noise

    Full text link
    We consider the family of stochastic partial differential equations indexed by a parameter \eps\in(0,1], \begin{equation*} Lu^{\eps}(t,x) = \eps\sigma(u^\eps(t,x))\dot{F}(t,x)+b(u^\eps(t,x)), \end{equation*} (t,x)\in(0,T]\times\Rd with suitable initial conditions. In this equation, LL is a second-order partial differential operator with constant coefficients, σ\sigma and bb are smooth functions and F˙\dot{F} is a Gaussian noise, white in time and with a stationary correlation in space. Let p^\eps_{t,x} denote the density of the law of u^\eps(t,x) at a fixed point (t,x)\in(0,T]\times\Rd. We study the existence of \lim_{\eps\downarrow 0} \eps^2\log p^\eps_{t,x}(y) for a fixed yRy\in\R. The results apply to a class of stochastic wave equations with d{1,2,3}d\in\{1,2,3\} and to a class of stochastic heat equations with d1d\ge1.Comment: 39 pages. Will be published in the book " Stochastic Analysis and Applications 2014. A volume in honour of Terry Lyons". Springer Verla

    On the exchange of intersection and supremum of sigma-fields in filtering theory

    Full text link
    We construct a stationary Markov process with trivial tail sigma-field and a nondegenerate observation process such that the corresponding nonlinear filtering process is not uniquely ergodic. This settles in the negative a conjecture of the author in the ergodic theory of nonlinear filters arising from an erroneous proof in the classic paper of H. Kunita (1971), wherein an exchange of intersection and supremum of sigma-fields is taken for granted.Comment: 20 page

    Convergence to SPDEs in Stratonovich form

    Full text link
    We consider the perturbation of parabolic operators of the form t+P(x,D)\partial_t+P(x,D) by large-amplitude highly oscillatory spatially dependent potentials modeled as Gaussian random fields. The amplitude of the potential is chosen so that the solution to the random equation is affected by the randomness at the leading order. We show that, when the dimension is smaller than the order of the elliptic pseudo-differential operator P(x,D)P(x,D), the perturbed parabolic equation admits a solution given by a Duhamel expansion. Moreover, as the correlation length of the potential vanishes, we show that the latter solution converges in distribution to the solution of a stochastic parabolic equation with a multiplicative term that should be interpreted in the Stratonovich sense. The theory of mild solutions for such stochastic partial differential equations is developed. The behavior described above should be contrasted to the case of dimensions that are larger than or equal to the order of the elliptic pseudo-differential operator P(x,D)P(x,D). In the latter case, the solution to the random equation converges strongly to the solution of a homogenized (deterministic) parabolic equation as is shown in the companion paper [2]. The stochastic model is therefore valid only for sufficiently small space dimensions in this class of parabolic problems.Comment: 21 page

    A report of a rare congenital malformation in a Nepalese child with congenital pouch colon: a case report

    Get PDF
    Congenital pouch colon is one of rare congenital anomalies. We report a 3-day-old male child with congenital pouch colon who underwent a window colostomy but died because of overwhelming sepsis. Due to its rarity, many surgeons in our part of the world may not be aware of it, hence increasing the potential to its mismanagement. However, with simple keen observations, we can safely come to its diagnosis. The aim of this report is to bring attention to congenital pouch colon associated with anorectal malformation in our country, with a brief emphasis on an approach to its diagnosis and initial management

    Elliptic flow in Pb+Pb collisions at sqrt{s_{NN}} = 2.76 TeV: hybrid model assessment of the first data

    Full text link
    We analyze the elliptic flow parameter v_2 in Pb+Pb collisions at sqrt{s_{NN}} = 2.76 TeV and in Au+Au collisions at sqrt{s_{NN}} =200 GeV using a hybrid model in which the evolution of the quark gluon plasma is described by ideal hydrodynamics with a state-of-the-art lattice QCD equation of state, and the subsequent hadronic stage by a hadron cascade model. For initial conditions, we employ Monte-Carlo versions of the Glauber and the Kharzeev-Levin-Nardi models and compare results with each other. We demonstrate that the differential elliptic flow v_2(p_T) hardly changes when the collision energy increases, whereas the integrated v_2 increases due to the enhancement of mean transverse momentum. The amount of increase of both v_2 and mean p_T depends significantly on the model of initialization.Comment: 5 pages, 5 figure

    Large Deviations for Stochastic Nematic Liquid Crystals driven by Multiplicative Gaussian Noise

    Get PDF
    We study a stochastic two-dimensional nematic liquid crystal model with multiplicative Gaussian noise. We prove the Wentzell-Freidlin type large deviations principle for the small noise asymptotic of solutions using weak convergence metho
    corecore