Solutions without singularities in gauge theory of gravitation

A de-Sitter gauge theory of the gravitational field is developed using a spherical symmetric Minkowski space-time as base manifold. The gravitational field is described by gauge potentials and the mathematical structure of the underlying space-time is not affected by physical events. The field equations are written and their solutions without singularities are obtained by imposing some constraints on the invariants of the model. An example of such a solution is given and its dependence on the cosmological constant is studied. A comparison with results obtained in General Relativity theory is also presented. Keywords: gauge theory, gravitation, singularity, computer algebraComment: 9 pages, no figure

Noncommutative gauge theory using covariant star product defined between Lie-valued differential forms

We develop an internal gauge theory using a covariant star product. The space-time is a symplectic manifold endowed only with torsion but no curvature. It is shown that, in order to assure the restrictions imposed by the associativity property of the star product, the torsion of the space-time has to be covariant constant. An illustrative example is given and it is concluded that in this case the conditions necessary to define a covariant star product on a symplectic manifold completely determine its connection.Comment: AMS-LaTeX 19 pages. v2: corrections in language and equations (typos), expanded sections 3-5, added references. v3: minor presentational and grammatical corrections, completed, corrected and reordered some references

Noncommutative BTZ Black Hole in Polar Coordinates

Based on the equivalence between the three dimensional gravity and the Chern-Simons theory, we obtain a noncommutative BTZ black hole solution as a solution of $U(1,1)\times U(1,1)$ noncommutative Chern-Simons theory using the Seiberg-Witten map. The Seiberg-Witten map is carried out in a noncommutative polar coordinates whose commutation relation is equivalent to the usual canonical commutation relation in the rectangular coordinates up to first order in the noncommutativity parameter $\theta$. The solution exhibits a characteristic of noncommutative polar coordinates in such a way that the apparent horizon and the Killing horizon coincide only in the non-rotating limit showing the effect of noncommutativity between the radial and angular coordinates.Comment: 14 pages, V2: minor changes, v3: reduced for clarification, a reference adde

Magneto-sensitive nickel nanowires fabricated by electrodeposition into multi- and single-ion track templates

Polycarbonate templates of (30±1) μm thickness containing cylindrical etched-track nanochannels of (500±50) nm diameter were used for electrodeposition of Ni nanowires. Using 104 channels per cm2, the most favourable deposition potential of  − 1.0 V was determined in a potentiostatic mode by varying the deposition potential with respect to an Ag/AgCl reference electrode over a range between  − 0.1 V and  − 1.5 V. The deposition efficiency at  − 1.0 V was estimated around 10%. The resulting single wires had a resistance around 200 Ω and showed an anisotropic magnetoresistance (AMR) effect of 1%, applicable to directionally sensitive magnetic field sensors

The prevalence of intragenic deletions in patients with idiopathic hypogonadotropic hypogonadism and Kallmann syndrome

Idiopathic hypogonadotropic hypogonadism (IHH) and Kallmann syndrome (KS) are clinically and genetically heterogeneous disorders caused by a deficiency of gonadotrophin-releasing hormone (GnRH). Mutations in three genes—KAL1, GNRHR and FGFR1—account for 15–20% of all causes of IHH/KS. Nearly all mutations are point mutations identified by traditional PCR-based DNA sequencing. The relatively new method of multiplex ligation-dependent probe amplification (MLPA) has been successful for detecting intragenic deletions in other genetic diseases. We hypothesized that MLPA would detect intragenic deletions in ∼15–20% of our cohort of IHH/KS patients. Fifty-four IHH/KS patients were studied for KAL1 deletions and 100 were studied for an autosomal panel of FGFR1, GNRH1, GNRHR, GPR54 and NELF gene deletions. Of all male and female subjects screened, 4/54 (7.4%) had KAL1 deletions. If only anosmic males were considered, 4/33 (12.1%) had KAL1 deletions. No deletions were identified in any of the autosomal genes in 100 IHH/KS patients. We believe this to be the first study to use MLPA to identify intragenic deletions in IHH/KS patients. Our results indicate ∼12% of KS males have KAL1 deletions, but intragenic deletions of the FGFR1, GNRH1, GNRHR, GPR54 and NELF genes are uncommon in IHH/KS

The cost-effectiveness of a new disease management model for frail elderly living in homes for the elderly, design of a cluster randomized controlled clinical trial

<p>Abstract</p> <p>Background</p> <p>The objective of this article is to describe the design of a study to evaluate the clinical and economic effects of a Disease Management model on functional health, quality of care and quality of life of persons living in homes for the elderly.</p> <p>Methods</p> <p>This study concerns a cluster randomized controlled clinical trial among five intervention homes and five usual care homes in the North-West of the Netherlands with a total of over 500 residents. All persons who are not terminally ill, are able to be interviewed and sign informed consent are included. For cognitively impaired persons family proxies will be approached to provide outcome information. The Disease Management Model consists of several elements: (1) Trained staff carries out a multidimensional assessment of the patients functional health and care needs with the interRAI Long Term Care Facilities instrument (LTCF). Computerization of the LTCF produces immediate identification of problem areas and thereby guides individualized care planning. (2) The assessment outcomes are discussed in a Multidisciplinary Meeting (MM) with the nurse, primary care physician, nursing home physician and Psychotherapist and if necessary other members of the care team. The MM presents individualized care plans to manage or treat modifiable disabilities and risk factors. (3) Consultation by an nursing home physician and psychotherapist is offered to the frailest residents at risk for nursing home admission (according to the interRAI LTCF). Outcome measures are Quality of Care indicators (LTCF based), Quality Adjusted Life Years (Euroqol), Functional health (SF12, COOP-WONCA), Disability (GARS), Patients care satisfaction (QUOTE), hospital and nursing home days and mortality, health care utilization and costs.</p> <p>Discussion</p> <p>This design is unique because no earlier studies were performed to evaluate the effects and costs of this Disease Management Model for disabled persons in homes for the elderly on functional health and quality of care.</p> <p>Trail registration number</p> <p>ISRCTN11076857</p