Myxozoan pathogens in cultured Malaysian fishes. I. Myxozoan infections of the sutchi catfish Pangasius hypophthalmus in freshwater cage cultures

Cage-cultured sutchi catfish Pangasius hypophthalmus (Sauvage, 1878), a favourite food fish in Southeast Asia, proved to be infected by 6 myxozoan species. Three species belonged to the genus Hennegoides (H. berlandi, H. malayensis, and H. pangasii), 1 to Henneguya (H. shariffi) and 2 to Myxobolus (M. baskai, and M. pangasii). Five myxozoans infected the gills and 1 was found on the spleen. Myxozoans infecting the gills were characterised by a specific site selection. H. shariffi sp. n. and H. berlandi sp. n. formed plasmodia in the multi-layered epithelium of the gill filaments. Of the 2 vascular species H. pangasii sp. n. developed in the gin arteries, while M. baskai sp. n. infected the capillary network of the gill lamellae. Plasmodia of H. malayensis sp. n. were found inside the cartilaginous gill rays of the filaments. Large plasmodia of M. pangasii sp. n. were located in a groove of the spleen but they affected only the serosa layer covering the spleen

Myxozoan pathogens in cultured Malaysian fishes. II. Myxozoan infections of redtail catfish Hemibagrus nemurus in freshwater cage cultures

Cage-cultured Asian redtail catfish Hemibagrus nemurus (Valenciennes, 1840), a popular food fish in Southeast Asia, proved to be infected by 3 myxozoan species. All the 3 species belonged to the genus Henneguya: 2 were identified as H. mystusia Sarkar, 1985 and H. hemibagri Tchang et Ma, 1993, while the other was described as H, basifilamentalis sp. n. All plasmodia were found in the gills and were characterised by a specific site selection. H. mystusia formed plasmodia in the multi-layered epithelium between the gill lamellae and in the non-lamellar edge of the gill filaments, while H. hemibagri developed in the capillary network of the lamellae. H. basifilamentalis sp. n. had large oval plasmodia located deep among the filaments just above the gill arch

Partial distance correlation with methods for dissimilarities

Partial distance correlation measures association between two random vectors with respect to a third random vector, analogous to, but more general than (linear) partial correlation. Distance correlation characterizes independence of random vectors in arbitrary dimension. Motivation for the definition is discussed. We introduce a Hilbert space of U-centered distance matrices in which squared distance covariance is the inner product. Simple computation of the sample partial distance correlation and definitions of the population coefficients are presented. Power of the test for zero partial distance correlation is compared with power of the partial correlation test and the partial Mantel test. © Springer International Publishing Switzerland 2016

Diszlokáció rendszerek statisztikus tulajdonságainak vizsgálata = Investigation of the statistical properties of dislocation ensembles

A pályázat célkitűzéseinek megfelelően diszlokációk kollektív tulajdonságait vizsgáltuk mint elméletileg mind kísérletileg. Analitikus számításokkal és numerikus szimulációval vizsgáltuk a diszlokációk következtében kialakuló belső feszültségeloszlás tulajdonságait. Megállapítottuk, hogy az eloszlás központi része Lorentz eloszlású, míg a lecsengő tartományban a feszültség köbével fordítottan arányos. Továbbá kimutattuk, hogy a külső feszültség hatására egy a feszültség 4. hatványával leeső aszimmetrikus tag jelenik meg. Megmutattuk, hogy egy 2D diszlokációrendszer relaxációja során a különböző fizikai mennyiségek az idő hatványfüggvényeként csengenek le. Kimutattuk, hogy a diszlokáció climb bekapcsolása jól definiált cellaszerkezet kialakulásához vezet.. A korábban mikroszkopikus meggondolásokkal kidolgozott diszlokáció kontinuum elméletet sikerült egy variációs elvből származtatni. Ez lehetővé tette az elmélet általánosítását többszörös csúszásra ill. oldott atomok hatásának beépítését is. Az elmélet segítségével részletesen megvizsgáltuk egy extra hozzáadott diszlokáció terének árnyékolását a többi diszlokáció átrendeződése következtében (Debye screening) . A kísérleti munka során nanoindentációval Cu egykristályokon meghatároztuk a mikrokeménység relatív fluktuációját. Az irodalomban először megállapítottuk, hogy a diszlokációsűrűséghez hasonlóan ez is az alkalmazott feszültség függvényében egy éles maximumot mutat. | According to the proposal the collective properties of dislocations were investigated both by theoretical and experimental methods. The properties of the internal stress distribution generated by dislocations were investigated by analytical calculations and computer simulations. It was found that the central part of the distribution is Loretzian while its tail decays with the invers cube of the stress. If external stress is applied the distribution becomes asymmetric. The antisymmetric part decaying with the invers fourth power of the stress. Numerical studies show that during the relaxation of the dislocation ensemble the different macroscopic quantities decay with some power of the time. Beside this, it is obtained that the dislocation climb leads to the the formation of cell structure. The continuum theory of dislocations derived earlier from microscopic considerations was reformulated into a phase field theory. This allowed us to extend the theory to multiple slip and study the influence of solute atoms. With this framework the Debye screening of the stress field of an extra dislocation was analysed in details . The relative fluctuation of microhardness (RFM) was determined by nanoindentation performed on deformed Cu single crystals. It was found that like the fluctuation of the dislocation density the RFM alo exhibits a sharp maximum as a function of applied stress

Gallstone Ileus, Bouveret's Syndrome and Choledocholithiasis in a Patient with Billroth II Gastrectomy – A Case Report of Combined Endoscopic and Surgical Therapy

Intestinal obstruction due to gallstone is a rare, but quite severe gastrointestinal disorder, which always requires a rapid and correct diagnosis to achieve optimal therapy. Digestive endoscopy is an important method to determine the level of the bowel obstruction and to plan an optimal therapeutic strategy. Our present case demonstrates that in a high-risk patient, a combined endoscopic and surgical therapy is the best choice to solve the obstruction of the colon, of the stomach and of the common bile duct caused by multiple gallstones

Analogies between the crossing number and the tangle crossing number

Tanglegrams are special graphs that consist of a pair of rooted binary trees with the same number of leaves, and a perfect matching between the two leaf-sets. These objects are of use in phylogenetics and are represented with straightline drawings where the leaves of the two plane binary trees are on two parallel lines and only the matching edges can cross. The tangle crossing number of a tanglegram is the minimum crossing number over all such drawings and is related to biologically relevant quantities, such as the number of times a parasite switched hosts. Our main results for tanglegrams which parallel known theorems for crossing numbers are as follows. The removal of a single matching edge in a tanglegram with $n$ leaves decreases the tangle crossing number by at most $n-3$, and this is sharp. Additionally, if $\gamma(n)$ is the maximum tangle crossing number of a tanglegram with $n$ leaves, we prove $\frac{1}{2}\binom{n}{2}(1-o(1))\le\gamma(n)<\frac{1}{2}\binom{n}{2}$. Further, we provide an algorithm for computing non-trivial lower bounds on the tangle crossing number in $O(n^4)$ time. This lower bound may be tight, even for tanglegrams with tangle crossing number $\Theta(n^2)$.Comment: 13 pages, 6 figure

Ward's Hierarchical Clustering Method: Clustering Criterion and Agglomerative Algorithm

The Ward error sum of squares hierarchical clustering method has been very widely used since its first description by Ward in a 1963 publication. It has also been generalized in various ways. However there are different interpretations in the literature and there are different implementations of the Ward agglomerative algorithm in commonly used software systems, including differing expressions of the agglomerative criterion. Our survey work and case studies will be useful for all those involved in developing software for data analysis using Ward's hierarchical clustering method.Comment: 20 pages, 21 citations, 4 figure

Four simple axioms of dependence measures

Recently new methods for measuring and testing dependence have appeared in the literature. One way to evaluate and compare these measures with each other and with classical ones is to consider what are reasonable and natural axioms that should hold for any measure of dependence. We propose four natural axioms for dependence measures and establish which axioms hold or fail to hold for several widely applied methods. All of the proposed axioms are satisfied by distance correlation. We prove that if a dependence measure is defined for all bounded nonconstant real valued random variables and is invariant with respect to all one-to-one measurable transformations of the real line, then the dependence measure cannot be weakly continuous. This implies that the classical maximal correlation cannot be continuous and thus its application is problematic. The recently introduced maximal information coefficient has the same disadvantage. The lack of weak continuity means that as the sample size increases the empirical values of a dependence measure do not necessarily converge to the population value