Negative-Energy Spinors and the Fock Space of Lattice Fermions at Finite Chemical Potential

Recently it was suggested that the problem of species doubling with Kogut-Susskind lattice fermions entails, at finite chemical potential, a confusion of particles with antiparticles. What happens instead is that the familiar correspondence of positive-energy spinors to particles, and of negative-energy spinors to antiparticles, ceases to hold for the Kogut-Susskind time derivative. To show this we highlight the role of the spinorial ``energy'' in the Osterwalder-Schrader reconstruction of the Fock space of non-interacting lattice fermions at zero temperature and nonzero chemical potential. We consider Kogut-Susskind fermions and, for comparison, fermions with an asymmetric one-step time derivative.Comment: 14p

Interval type-2 intuitionistic fuzzy logic systems - a comparative evaluation

Several fuzzy modeling techniques have been employed for handling uncertainties in data. This study presents a comparative evaluation of a new class of interval type-2 fuzzy logic system (IT2FLS) namely: interval type-2 intuitionistic fuzzy logic system (IT2IFLS) of Takagi Sugeno-Kang (TSK)-type with classical IT2FLS and its type-1 variant (IFLS). Simulations are conducted using a real-world gas compression system (GCS) dataset. Study shows that the performance of the proposed framework with membership functions (MFs) and non-membership functions (NMFs) that are each intervals is superior to classical IT2FLS with only MFs (upper and lower) and IFLS with MFs and NMFs that are not intervals in this problem domain

The Savvidy ``ferromagnetic vacuum'' in three-dimensional lattice gauge theory

The vacuum effective potential of three-dimensional SU(2) lattice gauge theory in an applied color-magnetic field is computed over a wide range of field strengths. The background field is induced by an external current, as in continuum field theory. Scaling and finite volume effects are analyzed systematically. The first evidence from lattice simulations is obtained of the existence of a nontrivial minimum in the effective potential. This supports a ``ferromagnetic'' picture of gluon condensation, proposed by Savvidy on the basis of a one-loop calculation in (3+1)-dimensional QCD.Comment: 9pp (REVTEX manuscript). Postscript figures appende

Using level-2 fuzzy sets to combine uncertainty and imprecision in fuzzy regions

In many applications, spatial data need to be considered but are prone to uncertainty or imprecision. A fuzzy region - a fuzzy set over a two dimensional domain - allows the representation of such imperfect spatial data. In the original model, points of the fuzzy region where treated independently, making it impossible to model regions where groups of points should be considered as one basic element or subregion. A first extension overcame this, but required points within a group to have the same membership grade. In this contribution, we will extend this further, allowing a fuzzy region to contain subregions in which not all points have the same membership grades. The concept can be used as an underlying model in spatial applications, e.g. websites showing maps and requiring representation of imprecise features or websites with routing functions needing to handle concepts as walking distance or closeby

Geometrical Research of Erosive Processes Using the Method of Triplet Quasiconvergent Phototopography

Запропоновано досліджувати ерозію ґрунту із застосуванням методу триплетної квазіконвергентної фототопографії. Розроблено методику організації польового геостаціонару, обґрунтувано поетапність польових і камеральних робіт. Дано теорію методу визначення елементів внутрішнього та зовнішнього орієнтування квазі- й реальних знімків. Виконано практичну апробацію методу та емпірично отримано його точність.There is proposed to study soil erosion using the method of triplet quasiconvergent phototopography. The method of organization of field geo permanent establishment was elaborated, the grounds of phasing field and laboratory works were accomplished. There was given a theory of method for inner and outer orientation of quasi- and real photographs determination. There was done practical approbation of the method and its precision was received empirical

USE OF WOUND PROTECTOR FOR PREVENTION OF SURGICAL SITE INFECTION IN LAPAROSCOPIC CHOLECYSTECTOMY

The work is based on the experience of 759 cholecystectomies performed in 2015-2018. Patients with a 3-4 grades of microbial contamination of wounds were divided into two groups: the first, with removal of the gallbladder traditionally with specimen retrieval container and the second, where proposed method of combined use of container and wound protector was used − 19 patients.Surgical site infection in laparoscopic cholecystectomy was detected in 5.40% (41 patients out of 759). During surgical interventions related to the second grade of microbial contamination (clean-contaminated), the frequency of SSI was 2.50%, to the third grade (contaminated) − 11.76%, and to the fourth grade (dirty) − 34.92%. Using the proposed method for the simultaneous use of the retrieval container and the double-ring wound protector in the second and third grades of wounds in LC allowed to reduce the frequency of SSI from 37.70% to 5.26%.The work is based on the experience of 759 cholecystectomies performed in 2015-2018. Patients with a 3-4 grades of microbial contamination of wounds were divided into two groups: the first, with removal of the gallbladder traditionally with specimen retrieval container and the second, where proposed method of combined use of container and wound protector was used − 19 patients.Surgical site infection in laparoscopic cholecystectomy was detected in 5.40% (41 patients out of 759). During surgical interventions related to the second grade of microbial contamination (clean-contaminated), the frequency of SSI was 2.50%, to the third grade (contaminated) − 11.76%, and to the fourth grade (dirty) − 34.92%. Using the proposed method for the simultaneous use of the retrieval container and the double-ring wound protector in the second and third grades of wounds in LC allowed to reduce the frequency of SSI from 37.70% to 5.26%

Quenched QCD at finite density: g=1g=1 and g=∞g=\infty

We report on our ongoing effort to understand quenched lattice QCD at finite baryon number density. The quenched theory is sensitive to the baryon mass both at strong coupling and in the scaling region. However, we find that the quenched model is pathological for $\mu > m_\pi/2$ at $\beta= 6.0$, in agreement with past Lanczos analyses of the Dirac operator.Comment: Contribution to Lat94, 3 pages, tar-compressed uuencoded ps fil

Maximum gradient embeddings and monotone clustering

Let (X,d_X) be an n-point metric space. We show that there exists a distribution D over non-contractive embeddings into trees f:X-->T such that for every x in X, the expectation with respect to D of the maximum over y in X of the ratio d_T(f(x),f(y)) / d_X(x,y) is at most C (log n)^2, where C is a universal constant. Conversely we show that the above quadratic dependence on log n cannot be improved in general. Such embeddings, which we call maximum gradient embeddings, yield a framework for the design of approximation algorithms for a wide range of clustering problems with monotone costs, including fault-tolerant versions of k-median and facility location.Comment: 25 pages, 2 figures. Final version, minor revision of the previous one. To appear in "Combinatorica

Effect of arginine on oligomerization and stability of N-acetylglutamate synthase.

N-acetylglutamate synthase (NAGS; E.C.2.3.1.1) catalyzes the formation of N-acetylglutamate (NAG) from acetyl coenzyme A and glutamate. In microorganisms and plants, NAG is the first intermediate of the L-arginine biosynthesis; in animals, NAG is an allosteric activator of carbamylphosphate synthetase I and III. In some bacteria bifunctional N-acetylglutamate synthase-kinase (NAGS-K) catalyzes the first two steps of L-arginine biosynthesis. L-arginine inhibits NAGS in bacteria, fungi, and plants and activates NAGS in mammals. L-arginine increased thermal stability of the NAGS-K from Maricaulis maris (MmNAGS-K) while it destabilized the NAGS-K from Xanthomonas campestris (XcNAGS-K). Analytical gel chromatography and ultracentrifugation indicated tetrameric structure of the MmMNAGS-K in the presence and absence of L-arginine and a tetramer-octamer equilibrium that shifted towards tetramers upon binding of L-arginine for the XcNAGS-K. Analytical gel chromatography of mouse NAGS (mNAGS) indicated either different oligomerization states that are in moderate to slow exchange with each other or deviation from the spherical shape of the mNAGS protein. The partition coefficient of the mNAGS increased in the presence of L-arginine suggesting smaller hydrodynamic radius due to change in either conformation or oligomerization. Different effects of L-arginine on oligomerization of NAGS may have implications for efforts to determine the three-dimensional structure of mammalian NAGS