On the derivation of the Dirac Equation

We point out that the anticommutation properties of the Dirac matrices can be derived without squaring the Dirac hamiltonian, that is, without explicit reference to the Klein-Gordon equation. We only require the Dirac equation to admit two linearly independent plane wave solutions with positive energy for all momenta. The necessity of negative energies as well as the trace and determinant properties of the Dirac matrices are also a direct consequence of this simple and minimal requirement.Comment: 10 page

Modular Logic Argumentation in Arg-tuProlog

A modular extension of Arg-tuProlog, a light-weight argumentation tool, is here presented and discussed, highlighting how it enables reasoning with rules and interpretations of multiple legal systems. Its effectiveness is demonstrated with examples from different national private international law (PIL) laws, running in Arg-tuProlog. PIL addresses overlaps and conflicts between legal systems by distributing cases between the authorities of such systems (jurisdiction) and establishing what rules these authorities have to apply to each case (choice of law)

Roles for Intestinal Bacteria, Viruses, and Fungi in Pathogenesis of Inflammatory Bowel Diseases and Therapeutic Approaches

Intestinal microbiota are involved in the pathogenesis of Crohn’s disease, ulcerative colitis, and pouchitis. We review the mechanisms by which these gut bacteria, fungi, and viruses mediate mucosal homeostasis, via their composite genes (metagenome) and metabolic products (metabolome). We explain how alterations to their profiles and functions under conditions of dysbiosis contribute to inflammation and effector immune responses that mediate inflammatory bowel diseases (IBD) in humans and enterocolitis in mice. It could be possible to engineer the intestinal environment by modifying the microbiota community structure or function to treat patients with IBD— either with individual agents, via dietary management, or as adjuncts to immunosuppressive drugs. We summarize the latest information on therapeutic use of fecal microbial transplantation and propose improved strategies to selectively normalize the dysbiotic microbiome in personalized approaches to treatment

New grayscale hit-miss operator

The morphological binary hit-miss operator has been used extensively to locate features within a binary image. We propose a grayscale hit-miss operator that detects signal shapes and is applicable to scalar-valued functions on one, two, or more dimensions. The hit and miss structuring elements define the lower and upper bounds of the signal: If a signal lies between the hit and miss templates, then the hit-miss operator will produce a one output; otherwise, it will respond with zero. We incorporate a fuzzy logic element to the hit-miss operator to indicate how strongly the signal matches the hit-miss templates

Exact Treatment of the Pauli Exclusion Operator in Nuclear Matter Calculation

Exact expressions of the Pauli exclusion operator Q in the nuclear matter calculation are presented in detail. Exact formulae are also given for the calculations of the single-particle-potential energy and the binding energy per nucleon with the exact Q operator. Numerical calculations of the G matrix in the lowest-order Brueckner theory are carried out to check the reliability of the standard angle-average approximation for the Q operator by employing the Bonn B and C NN potentials. It is observed that the exact treatment of the operator Q brings about non-negligible and attractive contributions to the binding energy.Comment: 16 pages, 3 figure

A Preliminary Study of Trunk Kinematics during Walking in Normal Subjects

The purpose of this study was to systematically describe the three-dimensional trunk kinematics in normal subjects, to establish a baseline for comparison to future research in gait analysis and aid in the identification of pathological gait. Seventeen volunteers between the ages of twenty and fifty, who met criteria for normal subjects, participated in this study. Trunk kinematic data were collected using an optoelectronic technique. An ensemble average of trunk kinematic data in each of the cardinal planes was plotted in degrees of motion versus percentage of gait cycle. A distinct pattern of trunk kinematics during gait was found in this study. Trunk motion relative to the pelvis was of greater magnitude than motion relative to the lab in the frontal and transverse planes. Inter-subject variability ranged from 37% to 644%, with the greatest amount of variability occurring in measurements of trunk movement relative to the lab in all three planes. Stride to stride variability within subjects ranged from 28% to 182%, with the greatest amount of intra-subject variability in trunk movements relative to the pelvis

Isospin splitting of the nucleon mean field

The isospin splitting of the nucleon mean field is derived from the Brueckner theory extended to asymmetric nuclear matter. The Argonne V18 has been adopted as bare interaction in combination with a microscopic three body force. The isospin splitting of the effective mass is determined from the Brueckner-Hartree-Fock self-energy: It is linear acording to the Lane ansatz and such that $m^*_n > m^*_p$ for neutron-rich matter. The symmetry potential is also determined and a comparison is made with the predictions of the Dirac-Brueckner approach and the phenomenological interactions. The theoretical predictions are also compared with the empirical parametrizations of neutron and proton optical-model potentials based on the experimental nucleon-nucleus scattering and the phenomenological ones adopted in transport-model simulations of heavy-ion collisions. The direct contribution of the rearrangement term due to three-body forces to the single particle potential and symmetry potential is discussed.Comment: 8 pages, 10 figure

Therapeutic manipulation of the enteric microflora in inflammatory bowel diseases: antibiotics, probiotics, and prebiotics

AbstractCrohn's disease, ulcerative colitis, and pouchitis are caused by overly aggressive immune responses to a subset of commensal (nonpathogenic) enteric bacteria in genetically predisposed individuals. Clinical and experimental studies suggest that the relative balance of aggressive and protective bacterial species is altered in these disorders. Antibiotics can selectively decrease tissue invasion and eliminate aggressive bacterial species or globally decrease luminal and mucosal bacterial concentrations, depending on their spectrum of activity. Alternatively, administration of beneficial bacterial species (probiotics), poorly absorbed dietary oligosaccharides (prebiotics), or combined probiotics and prebiotics (synbiotics) can restore a predominance of beneficial Lactobacillus and Bifidobacterium species. Current clinical trials do not fulfill evidence-based criteria for using these agents in inflammatory bowel diseases (IBD), but multiple nonrigorous studies and widespread clinical experience suggest that metronidazole and/or ciprofloxacin can treat Crohn's colitis and ileocolitis (but not isolated ileal disease), perianal fistulae and pouchitis, whereas selected probiotic preparations prevent relapse of quiescent ulcerative colitis and relapsing pouchitis. These physiologic approaches offer considerable promise for treating IBD, but must be supported by rigorous controlled therapeutic trials that consider clinical disease before their widespread clinical acceptance. These agents likely will become an integral component of treating IBD in combination with traditional anti-inflammatory and immunosuppressive agents

Genetic Factors in Animal Models of Intestinal Inflammation

The critical importance of host genetic susceptibility in determining chronicity, aggressiveness and complications of intestinal inflammation is clearly demonstrated by studies of inbred rodents, transgenic rats and spontaneous mutants. Inbred Lewis rats challenged by purified bacterial cell wall polymers, indomethacin or small bowel bacterial overgrowth develop chronic granulomatous intestinal inflammation with fibrosis and extraintestinal manifestations, whereas Fischer (major histocompatibility complex identical to Lewis) and Buffalo rats identically stimulated demonstrate only self-limited enterocolitis with no chronic inflammation, fibrosis, granulomas or extraintestinal inflammation. Similar differential patterns of intestinal inflammation are apparent in inbred mouse strains challenged with trinitrobenzene-sulphonic acid, Citrobacter freundii or backcrossed with T cell receptor deficient (knockout) mice. The dominant role of genetic background in induction of intestinal inflammation is further documented by spontaneous colitis which develops in spontaneously mutant mice, cotton-top tamarins, human leukocyte antigen-B27/ β2 microglobulin transgenic rats and mice with targeted deletions of certain immunoregulatory cytokine and T lymphocyte genes. Identification of the immunological mechanisms of host genetic susceptibility and the genetic basis of spontaneous colitis should provide new insights into the pathogenesis of human inflammatory bowel disease