On the holomorphic factorization for superconformal fields

For a generic value of the central charge, we prove the holomorphic factorization of partition functions for free superconformal fields which are defined on a compact Riemann surface without boundary. The partition functions are viewed as functionals of the Beltrami coefficients and their fermionic partners which variables parametrize superconformal classes of metrics.Comment: 5 pages, LATEX, MPI-Ph/92-7

The Polyakov action on the supertorus

A consistent method for obtaining a well-defined Polyakov action on the supertorus is presented. This method uses the covariantization of derivative operators and enables us to construct a Polyakov action which is globally defined.Comment: 15 pages LaTe

On the existence of exotic and non-exotic multiquark meson states

To obtain an exact solution of a four-body system containing two quarks and two antiquarks interacting through two-body terms is a cumbersome task that has been tackled with more or less success during the last decades. We present an exact method for the study of four-quark systems based on the hyperspherical harmonics formalism that allows us to solve it without resorting to further approximations, like for instance the existence of diquark components. We apply it to systems containing two heavy and two light quarks using different quark-quark potentials. While $QQ\bar n \bar n$ states may be stable in nature, the stability of $Q\bar Qn \bar n$ states would imply the existence of quark correlations not taken into account by simple quark dynamical models.Comment: 3 pages. Contribution to the 20th European Conference on Few-Body Problems in Physics, Pisa, Italy. To be published in Few-Body system

Induced Polyakov supergravity on Riemann surfaces of higher genus

An effective action is obtained for the $N=1$, $2D-$induced supergravity on a compact super Riemann surface (without boundary) $\hat\Sigma$ of genus $g>1$, as the general solution of the corresponding superconformal Ward identity. This is accomplished by defining a new super integration theory on $\hat\Sigma$ which includes a new formulation of the super Stokes theorem and residue calculus in the superfield formalism. Another crucial ingredient is the notion of polydromic fields. The resulting action is shown to be well-defined and free of singularities on \sig. As a by-product, we point out a morphism between the diffeomorphism symmetry and holomorphic properties.Comment: LPTB 93-10, Latex file 20 page

Supersymmetric structure of the induced W gravities

We derive the supersymmetric structure present in W-gravities which has been already observed in various contexts as Yang-Mills theory, topological field theories, bosonic string and chiral W_{3}-gravity. This derivation which is made in the geometrical framework of Zucchini, necessitates the introduction of an appropriate new basis of variables which replace the canonical fields and their derivatives. This construction is used, in the W_{2}-case, to deduce from the Chern-Simons action the Wess-Zumino-Polyakov action.Comment: 17 pages, Latex. To appear in Class. Quantum. Gravit

d=2, N=2 Superconformal Symmetries and Models

We discuss the following aspects of two-dimensional N=2 supersymmetric theories defined on compact super Riemann surfaces: parametrization of (2,0) and (2,2) superconformal structures in terms of Beltrami coefficients and formulation of superconformal models on such surfaces (invariant actions, anomalies and compensating actions, Ward identities).Comment: 43 pages, late

Morpho-Rheological Fingerprinting of Rod Photoreceptors Using Real-Time Deformability Cytometry

Distinct cell-types within the retina are mainly specified by morphological and molecular parameters, however, physical properties are increasingly recognized as a valuable tool to characterize and distinguish cells in diverse tissues. High-throughput analysis of morpho-rheological features has recently been introduced using real-time deformability cytometry (RT-DC) providing new insights into the properties of different cell-types. Rod photoreceptors represent the main light sensing cells in the mouse retina that during development forms apically the densely packed outer nuclear layer. Currently, enrichment and isolation of photoreceptors from retinal primary tissue or pluripotent stem cell-derived organoids for analysis, molecular profiling, or transplantation is achieved using flow cytometry or magnetic activated cell sorting approaches. However, such purification methods require genetic modification or identification of cell surface binding antibody panels. Using primary retina and embryonic stem cell-derived retinal organoids, we characterized the inherent morpho-mechanical properties of mouse rod photoreceptors during development based on RT-DC. We demonstrate that rods become smaller and more compliant throughout development and that these features are suitable to distinguish rods within heterogenous retinal tissues. Hence, physical properties should be considered as additional factors that might affect photoreceptor differentiation and retinal development besides representing potential parameters for label-free sorting of photoreceptors

W-algebras from symplectomorphisms

It is shown how $W$-algebras emerge from very peculiar canonical transformations with respect to the canonical symplectic structure on a compact Riemann surface. The action of smooth diffeomorphisms of the cotangent bundle on suitable generating functions is written in the BRS framework while a $W$-symmetry is exhibited. Subsequently, the complex structure of the symmetry spaces is studied and the related BRS properties are discussed. The specific example of the so-called $W_3$-algebra is treated in relation to some other different approaches.Comment: LaTex, 25 pages, no figures, to appear in Journ. Math. Phy

A case of feline gastrointestinal eosinophilic sclerosing fibroplasia associated with phycomycetes

Feline gastrointestinal eosinophilic sclerosing fibroplasia (FGESF) is a recently described inflammatory condition of domestic cats with unknown aetiology. A proportion of cases of FGESF are associated with bacteria, but antibiotic treatment is ineffective. It has been hypothesized that genetically predisposed cats may develop FGESF in response to the introduction of bacteria or other antigens into the intestinal wall. A 9- month-old male Persian cat presented with a history of marked acute haematemesis. A mass (10 cm diameter) was detected within the pylorus and proximal duodenum and this was not surgically accessible. On necropsy examination the duodenal wall was seen to be markedly thickened with extensive mucosal ulceration. Microscopically, there were haphazardly oriented trabecular bands of dense eosinophilic collagen,separated by wide, clear areas containing variable numbers of fibroblasts, eosinophils, mast cells, neutrophils,macrophages, lymphocytes and plasma cells. Numerous pleomorphic, non-parallel walled, sparsely septate hyphae, characteristic of phycomycetes, were present within the collagen matrix. Colonies of gram-positive and gram-negative rods were also present within the lesion. This is the first description of FGESF with intralesional fungi