Representations of p-brane topological charge algebras

The known extended algebras associated with p-branes are shown to be generated as topological charge algebras of the standard p-brane actions. A representation of the charges in terms of superspace forms is constructed. The charges are shown to be the same in standard/extended superspace formulations of the action.Comment: 22 pages. Typos fixed, refs added. Minor additions to comments sectio

Trends of etiology and treatment in hepatocellular carcinoma over the years

Background: HCC has been the fastest-growing cause of cancer-related deaths. The aim of this study was to investigate the change trends in the etiology, treatment and mortality of HCC over the last 12 years.Methods: The study included 523 patients who were admitted to our clinic with the diagnosis of primary malignancy of the liver between 2006-2018. Demographic data, HCC etiologies, alpha feto-protein (AFP) values and imaging characteristics were recorded. The patients were divided into two groups as diagnosed before 2013 and 2013 and later. Because the number of patients with alcohol and HBV was high, it was evaluated as a separate etiology group. HCC was accepted related to NASH in the patients with obesity and diabetes mellitus (DM) after exclusion of HBV, HCV, and autoimmune hepatitis. The patients without obesity and DM were accepted as cryptogenic HCC and added to other etiologies group.Results: When the patients were evaluated, there was a significant increase in the rate of patients who were in compensated cirrhosis stage and in UCSF criteria in and 2013 and later (p = 0.0001, p = 0.037, respectively). A significant increase was observed in the ratio of NASH-related HCC 2013 and later (p = 0.032). Transplantation, resection and RFA / PEI rates were 14.9% before 2013 and 22.2% 2013 and later (p = 0.047).Conclusions: The rates of NAFLD related HCC due to diabetes and obesity are increasing. Knowing the change of HCC causes over the years is necessary for the effective treatment for these reasons in the future

Tensionless strings: physical Fock space and higher spin fields

I study the physical Fock space of the tensionless string theory with perimeter action, exploring its new gauge symmetry algebra. The cancellation of conformal anomaly requires the space-time to be 13-dimensional. All particles are massless and there are no tachyon states in the spectrum. The zero mode conformal operator defines the levels of the physical Fock space. All levels can be classified by the highest Casimir operator W of the little group E(11) for massless particles in 11-dimensions. The ground state is infinitely degenerated and contains massless gauge fields of arbitrary large integer spin, realizing the irreducible representations of E(11) of fixed helicity. The excitation levels realize CSR representations of little group E(11) with an infinite number of helicities. After inspection of the first excitation level, which, as I prove, is a physical null state, I conjecture that all excitation levels are physical null states. In this theory the tensor field of the second rank does not play any distinctive role and therefore one can suggest that in this model there is no gravity.Comment: 22 pages, Latex, references adde

Hamiltonian analysis of Poincar\'e gauge theory scalar modes

The Hamiltonian constraint formalism is used to obtain the first explicit complete analysis of non-trivial viable dynamic modes for the Poincar\'e gauge theory of gravity. Two modes with propagating spin-zero torsion are analyzed. The explicit form of the Hamiltonian is presented. All constraints are obtained and classified. The Lagrange multipliers are derived. It is shown that a massive spin-$0^-$ mode has normal dynamical propagation but the associated massless $0^-$ is pure gauge. The spin-$0^+$ mode investigated here is also viable in general. Both modes exhibit a simple type of ``constraint bifurcation'' for certain special field/parameter values.Comment: 28 pages, LaTex, submitted to International Journal of Modern Physics

An action principle for Vasiliev's four-dimensional higher-spin gravity

We provide Vasiliev's fully nonlinear equations of motion for bosonic gauge fields in four spacetime dimensions with an action principle. We first extend Vasiliev's original system with differential forms in degrees higher than one. We then derive the resulting duality-extended equations of motion from a variational principle based on a generalized Hamiltonian sigma-model action. The generalized Hamiltonian contains two types of interaction freedoms: One set of functions that appears in the Q-structure of the generalized curvatures of the odd forms in the duality-extended system; and another set depending on the Lagrange multipliers, encoding a generalized Poisson structure, i.e. a set of polyvector fields of ranks two or higher in target space. We find that at least one of the two sets of interaction-freedom functions must be linear in order to ensure gauge invariance. We discuss consistent truncations to the minimal Type A and B models (with only even spins), spectral flows on-shell and provide boundary conditions on fields and gauge parameters that are compatible with the variational principle and that make the duality-extended system equivalent, on shell, to Vasiliev's original system.Comment: 37 pages. References added, corrected typo

Percutaneous collagen induction (microneedling) for the management of non-atrophic scars: literature review.

Introduction: Percutaneous collagen induction (PCI) or needling techniques are increasingly popular in the reconstructive and aesthetic arena. The underlying mechanisms of action rest on producing a pattern of non-ablative and non-confluent puncture wound pattern to the dermis with a resulting regenerative effect to the skin. Methods: A detailed English literature review was conducted using PubMed Medline, Embase and Web of Science; the manuscripts were appraised and classified according to level of evidence as well risk of bias. Results are presented in descending order of evidence for non-atrophic scars. Discussion: On the basis of level 1 evidence currently available, the combination of needling and silicone gel can improve the short-term pliability, height and vascularity of hypertrophic and keloid scars. According to level 2 evidence, needling alongside spray keratinocytes can produce a statistically significant improvement to patient/observer scar ratings and improve pigmentation in hypopigmented burn scars at 12-month follow-up. Results from mixed cohort studies also point towards needling having a beneficial effect on fat graft retention. Level 3 data suggest that needling can render significant resurfacing effects to both mature and actively hypertrophic burn scars at 12-month follow-up based on objective scar scales; furthermore, favourable histological changes are seen, including better collagen alignment in the dermis and increased epidermal thickness. Conclusion: Needling techniques are promising adjuncts to non-atrophic scar management. Further research with long-term follow-up and comparative design protocols incorporating other resurfacing modalities is warranted before the exact value of needling is delineated in scar management protocols

Mixed-symmetry massless gauge fields in AdS(5)

Free AdS(5) mixed-symmetry massless bosonic and fermionic gauge fields of arbitrary spins are described by using su(2,2) spinor language. Manifestly covariant action functionals are constructed and field equations are derived.Comment: 13 pages; v2: title changed, typos corrected, minor changes, reference added; v3: minor changes, published versio

Differential Quadrature Solution of Hyperbolic Telegraph Equation

Differential quadrature method (DQM) is proposed for the numerical solution of one- and two-space dimensional hyperbolic telegraph equation subject to appropriate initial and boundary conditions. Both polynomial-based differential quadrature (PDQ) and Fourier-based differential quadrature (FDQ) are used in space directions while PDQ is made use of in time direction. Numerical solution is obtained by using Gauss-Chebyshev-Lobatto grid points in space intervals and equally spaced and/or GCL grid points for the time interval. DQM in time direction gives the solution directly at a required time level or steady state without the need of iteration. DQM also has the advantage of giving quite good accuracy with considerably small number of discretization points both in space and time direction