Fundamental properties and applications of quasi-local black hole horizons

The traditional description of black holes in terms of event horizons is inadequate for many physical applications, especially when studying black holes in non-stationary spacetimes. In these cases, it is often more useful to use the quasi-local notions of trapped and marginally trapped surfaces, which lead naturally to the framework of trapping, isolated, and dynamical horizons. This framework allows us to analyze diverse facets of black holes in a unified manner and to significantly generalize several results in black hole physics. It also leads to a number of applications in mathematical general relativity, numerical relativity, astrophysics, and quantum gravity. In this review, I will discuss the basic ideas and recent developments in this framework, and summarize some of its applications with an emphasis on numerical relativity.Comment: 14 pages, 2 figures. Based on a talk presented at the 18th International Conference on General Relativity and Gravitation, 8-13 July 2007, Sydney, Australi

Új módszertani lehetőségek és ezek alkalmazása a hormonális rendszer daganatainak genetikai kivizsgálásában

The technical developments leading to revolution in clinical genetic testing offer new approaches for patients with cancer. From one mutation or one gene approach the scale of genetic testing moved to whole exome or whole genome scale. It is well known that many tumours are genetically determined ans they are part of familial tumour syndromes. In addition, some mutations indicate specific molecular targeted therapies. Although sampling and sample preparation are different for testing germline and somatic mutations, the technical background of the analysis is the same. The aim of clinical genetic testing is to identify patients who are carriers of disease-causing mutations or to test tumour tissue for the presence of genetic alterations which may be targets for therapeutic approaches. In this review the authors summarize novel possibilities offered by next-generation sequencing in clinical genetic testing of patients with endocrine tumours. In addition, the authors review recent guidelines on technical and ethical issues related to these novel methods. Orv. Hetil., 2015, 156(51), 2063-2069

Modular detergents tailor the purification and structural analysis of membrane proteins including G-protein coupled receptors

Detergents enable the purification of membrane proteins and are indispensable reagents instructural biology. Even though a large variety of detergents have been developed in the lastcentury, the challenge remains to identify guidelines that allowfine-tuning of detergents forindividual applications in membrane protein research. Addressing this challenge, here weintroduce the family of oligoglycerol detergents (OGDs). Native mass spectrometry (MS)reveals that the modular OGD architecture offers the ability to control protein purificationand to preserve interactions with native membrane lipids during purification. In addition to abroad range of bacterial membrane proteins, OGDs also enable the purification and analysisof a functional G-protein coupled receptor (GPCR). Moreover, given the modular design ofthese detergents, we anticipatefine-tuning of their properties for specific applications instructural biology. Seen from a broader perspective, this represents a significant advance forthe investigation of membrane proteins and their interactions with lipids

Isolated horizons in higher-dimensional Einstein-Gauss-Bonnet gravity

The isolated horizon framework was introduced in order to provide a local description of black holes that are in equilibrium with their (possibly dynamic) environment. Over the past several years, the framework has been extended to include matter fields (dilaton, Yang-Mills etc) in D=4 dimensions and cosmological constant in $D\geq3$ dimensions. In this article we present a further extension of the framework that includes black holes in higher-dimensional Einstein-Gauss-Bonnet (EGB) gravity. In particular, we construct a covariant phase space for EGB gravity in arbitrary dimensions which allows us to derive the first law. We find that the entropy of a weakly isolated and non-rotating horizon is given by $\mathcal{S}=(1/4G_{D})\oint_{S^{D-2}}\bm{\tilde{\epsilon}}(1+2\alpha\mathcal{R})$. In this expression $S^{D-2}$ is the $(D-2)$-dimensional cross section of the horizon with area form $\bm{\tilde{\epsilon}}$ and Ricci scalar $\mathcal{R}$, $G_{D}$ is the $D$-dimensional Newton constant and $\alpha$ is the Gauss-Bonnet parameter. This expression for the horizon entropy is in agreement with those predicted by the Euclidean and Noether charge methods. Thus we extend the isolated horizon framework beyond Einstein gravity.Comment: 18 pages; 1 figure; v2: 19 pages; 2 references added; v3: 19 pages; minor corrections; 1 reference added; to appear in Classical and Quantum Gravit

Supersymmetric isolated horizons

We construct a covariant phase space for rotating weakly isolated horizons in Einstein-Maxwell-Chern-Simons theory in all (odd) $D\geq5$ dimensions. In particular, we show that horizons on the corresponding phase space satisfy the zeroth and first laws of black-hole mechanics. We show that the existence of a Killing spinor on an isolated horizon in four dimensions (when the Chern-Simons term is dropped) and in five dimensions requires that the induced (normal) connection on the horizon has to vanish, and this in turn implies that the surface gravity and rotation one-form are zero. This means that the gravitational component of the horizon angular momentum is zero, while the electromagnetic component (which is attributed to the bulk radiation field) is unconstrained. It follows that an isolated horizon is supersymmetric only if it is extremal and nonrotating. A remarkable property of these horizons is that the Killing spinor only has to exist on the horizon itself. It does not have to exist off the horizon. In addition, we find that the limit when the surface gravity of the horizon goes to zero provides a topological constraint. Specifically, the integral of the scalar curvature of the cross sections of the horizon has to be positive when the dominant energy condition is satisfied and the cosmological constant $\Lambda$ is zero or positive, and in particular rules out the torus topology for supersymmetric isolated horizons (unless $\Lambda<0$) if and only if the stress-energy tensor $T_{ab}$ is of the form such that $T_{ab}\ell^{a}n^{b}=0$ for any two null vectors $\ell$ and $n$ with normalization $\ell_{a}n^{a}=-1$ on the horizon.Comment: 26 pages, 1 figure; v2: typos corrected, topology arguments corrected, discussion of black rings and dipole charge added, references added, version to appear in Classical and Quantum Gravit

Modular detergents tailor the purification and structural analysis of membrane proteins including G-protein coupled receptors

Detergents enable the purification of membrane proteins and are indispensable reagents in structural biology. Even though a large variety of detergents have been developed in the last century, the challenge remains to identify guidelines that allow fine-tuning of detergents for individual applications in membrane protein research. Addressing this challenge, here we introduce the family of oligoglycerol detergents (OGDs). Native mass spectrometry (MS) reveals that the modular OGD architecture offers the ability to control protein purification and to preserve interactions with native membrane lipids during purification. In addition to a broad range of bacterial membrane proteins, OGDs also enable the purification and analysis of a functional G-protein coupled receptor (GPCR). Moreover, given the modular design of these detergents, we anticipate fine-tuning of their properties for specific applications in structural biology. Seen from a broader perspective, this represents a significant advance for the investigation of membrane proteins and their interactions with lipids

CNTF, COMT, DDR1, DISC1, DRD2, DRD3 es DTNBP1 kandidáns gének vizsgálata szkizofréniában: eredmények a Magyar SCHIZOBANK Konzorcium vizsgálataból

Schizophrenia is a chronic, debilitating psychiatric disorder characterized by heterogeneous clinical symptoms. Although the pathogenesis of this disorder is poorly understood, several lines of evidence support the role of both common and rare genetic variants in the etiology of schizophrenia. Common variants, single nucleotide polymorphisms can be investigated by candidate gene association studies or genome-wide association studies, while rare variants, single nucleotide variants are assessable by means of candidate gene resequencing or whole-exome and genome sequencing using next generation sequencing. In this study we investigated polymorphisms of 7 candidate genes in a Hungarian schizophrenia cohort. Candidate genes were chosen on the basis of previous results and biological plausibility. 390 patients were recruited in 5 centers in the framework of the Hungarian SCHIZOBANK Consortium, the schizophrenia sample was contrasted to 1069 healthy control individuals. In this sample SNPs of DDR1 and DRD2 genes demonstrated significant association with schizophrenia. The role of DDR1 and DRD2 genes in the etiology of schizophrenia warrant further investigation, based on their genomic localization and biological functions

Quasilocal formalism and thermodynamics of asymptotically flat black objects

We study the properties of 5-dimensional black objects by using the renormalized boundary stress-tensor for locally asymptotically flat spacetimes. This provides a more refined form of the quasilocal formalism which is useful for a holographic interpretation of asymptotically flat gravity. We apply this technique to examine the thermodynamic properties of black holes, black rings, and black strings. The advantage of using this method is that we can go beyond the `thin ring' approximation and compute the boundary stress tensor for any general (thin or fat) black ring solution. We argue that the boundary stress tensor encodes the necessarily information to distinguish between black objects with different horizon topologies in the bulk. We also study in detail the susy black ring and clarify the relation between the asymptotic charges and the charges defined at the horizon. Furthermore, we obtain the balance condition for `thin' dipole black rings.Comment: v2 clarifications on the advantage of using quasilocal formalism for black rings added, CQG versio