What does a measurement of mass and/or radius of a neutron star constrain: Equation of state or gravity?

Neutron stars (NSs) are thought to be excellent laboratories for determining the equation of state (EoS) of cold dense matter. Their strong gravity suggests that they can also be used to constrain gravity models. The mass and radius (M-R) of a NS both depend on the choice of EoS and gravity, meaning that NSs cannot be simultaneously good laboratories for both of these questions. A measurement of M-R would constrain the less well known physics input. The assumption that M-R measurements can be used to constrain EoS-presumes general relativity (GR) is the ultimate model of gravity in the classical regime. We calculate the radial profile of compactness and curvature (square root of the full contraction of the Weyl tensor) within a NS and determine the domain not probed by the Solar System tests of GR. We find that, except for a tiny sphere of radius less than a millimeter at the center, the curvature is several orders of magnitude above the values present in Solar System tests. The compactness is beyond the solar surface value for r>10 m, and increases by 5 orders of magnitude towards the surface. With the density being only an order of magnitude higher than that probed by nuclear scattering experiments, our results suggest that the employment of GR as the theory of gravity describing the hydrostatic equilibrium of NSs is a rather remarkable extrapolation from the regime of tested validity, as opposed to that of EoS models. Our larger ignorance of gravity within NSs suggests that a measurement of M-R constrains gravity rather than EoS, and given that EoS has yet to be determined by nucleon scattering experiments, M-R measurements cannot tightly constrain the gravity models either. Near the surface the curvature and compactness attain their largest values, while EoS in this region is fairly well known. This renders the crust as the best site to look for deviations from GR.Comment: Phys.Rev. D published, typos corrected to match the published versio

From real spaces to virtual spaces: The metaverse and decentralized cinema

Developments in computer and communication technologies, which constitute the starting point of concepts such as decentralization, virtuality, simulation, augmented reality and metaverse, have also brought new forms of expression and designs in art to the agenda. In addition to the decentralized data architecture and metaverse areas that emerged in parallel with the development of network technologies, applications that increase the user's interaction and beleaguered experience such as virtual reality, augmented reality and mixed reality have increased their effectiveness in this field. The metaverse spaces that emerge with the cooperation of software, art and architecture offer their users a more similar life simulation of natural life through augmented reality vehicles or screens. Here, users can perform new experiences for artistic production and consumption as well as daily life practices such as socialization and communication. Metaverse spaces, which include the design of a three-dimensional virtual universe that can be supported by augmented reality, are free from all the constraints of the real world as a cinematic plateau. It is seen as a great advantage that the real film set can create a cinematic work without expensive equipment such as cameras, lights, and sound away from all the negativities of the natural shooting conditions. The fact that the production, distribution and screening of cinema works can be realized within this field brings a new understanding of decentralized cinema to the agenda. Decentralized cinema, which has begun to rise in the expanding virtual geography of the metaverse virtual space with its advantages such as virtual characters and scenes and creative space fictions, is an art form worth examining. This study focuses on the possible future transformations of cinema in terms of production and representation in the context of the relationship of virtual and augmented reality technologies with developing metaverse areas. The emergence of a new cinematic ecology; The opportunities and obstacles it provides to producers are examined with the philosophical criticism method through concepts such as virtual and augmented reality, web 3.0, metaverse in terms of audience experiences it offers for screening.  As a result of the study, it was concluded that the metaverse area has many advantages in terms of the production of cinema works, democratization of the production and distribution of works, digital privacy and security for metaverse artists, and recognition of ownership for digital works of art

Involuntary Dissolution: Theory and Operation in Publicly Traded Corporations

Involuntary dissolution is recognized as the primary mechanism to monitor opportunism and remedy the aggrieved minority shareholders of corporations. Contrary to general understanding, involuntary dissolution is not idiosyncratic to close corporations. However, its application to publicly traded corporations requires an approach different than the one for close corporations. This note discusses and recommends the approach necessary to justify and effectively enforce involuntary dissolution statutes’ application in the context of publicly traded corporations. It expresses the opinion that the contractual view of corporate law would provide the theoretical basis necessary to construe the statute for publicly traded corporations and exemplifies its approach through the shareholder oppression law of the U.S. corporate law

PID Control of Hybrid DC-DC Converter System in Complex Load with Double Reference Time

DC-DC converters are circuits that are widely used in energy distribution systems, in industry and technology applications, as well as in household appliances such as computers and televisions, and in uninterruptible power supplies used to feed all these systems. For the design and optimization of DC-DC converter circuits, it is important to create and analyze mathematical models according to the load it is connected to. Simple load structures and circuit structures have been examined and control units have been designed in studies carried out to date. In this study, while the DC-DC converter with a more complex load structure is discussed, mathematical analysis and PID control of DC-DC converters with Buck-Boost feature are performed with the same modulation index in different time periods. In the results obtained, it is shown how to create the mathematical models of a system that provides DC-DC energy conversion with a complex load structure and how to formulate the PID control in a system with this complex load structure

Classification of GPCRs using family specific motifs

The classification of G-Protein Coupled Receptor (GPCR) sequences is an important problem that arises from the need to close the gap between the large number of orphan receptors and the relatively small number of annotated receptors. Equally important is the characterization of GPCR Class A subfamilies and gaining insight into the ligand interaction since GPCR Class A encompasses a very large number of drug-targeted receptors. In this thesis, a method for Class A subfamily classification using sequence-derived motifs which characterizes the subfamilies by discovering receptor-ligand interaction sites is proposed. The motifs that best characterize a subfamily are selected by the proposed Distinguishing Power Evaluation (DPE) technique. The experiments performed on GPCR sequence databases show that the proposed method outperforms state-of-the-art classification techniques for GPCR Class A subfamily prediction. An important contribution of this thesis is to discover key receptor-ligand interaction sites which is very important for drug design

Determinants of Competitiveness in European Regions: A Test of the Emerald Model

This study assesses the impact of the dimensions of the emerald model on regional competitiveness and contributes to the competitiveness literature in moving ahead to establishing causal links with its determinants. Data is collected from 2000 to 2011 for 97 NUTS-1 regions in Europe, and multiple regression analysis is performed. The results suggest that in the long term (eight-year time period) ownership attractiveness is the most influential dimension of the model, followed by talent attractiveness, educational attractiveness, R&D and innovation attractiveness, cluster attractiveness in technology & knowledge-based sectors, and environmental attractiveness. Cluster attractiveness in all sectors does not have a significant impact, while knowledge dynamics has a negative impact on competitiveness

Serum Asymmetric Dimethylarginine, Nitrate, Vitamin B12, and Homocysteine Levels in Individuals with Pulmonary Embolism

We aimed to analyze the pre- and posttreatment serum asymmetric dimethylarginine (ADMA), nitrate (NO3), vitamin B12 and homocysteine levels in pulmonary embolism (PTE) patients and to determine the prognostic value of these variables in predicting chronic thromboembolic pulmonary hypertension (CTEPH). This study was conducted in 64 patients. The patients were classified into the two groups: patients with normal pulmonary artery pressure (PAP) (group I) and patients with high PAP with persistent lung perfusion defects or who died at the end of 3 months of therapy (group II). We found statistically significant differences between two groups with respect to the partial oxygen pressure, the oxygen saturation, and the PAP, but there was no difference between the two groups with respect to the pretreatment ADMA, NO3, or homocysteine levels. The vitamin B12 levels were higher in group II. The NO3 levels increased and the ADMA and vitamin B12 levels decreased with treatment in both groups. These results suggest that these parameters are not predictive of the development of CTEPH

Underfilled blood tube containing EDTA: Is it an inappropriate sample for HbA1c assay?

IntroductionBlood samples having inappropriate volume are a substantial part of preanalytical errors. Inadequate sample volume for glycated haemoglobin (HbA1c) test may be a common problem of patients with diabetes mellitus having vascular changes. In this study, we compared HbA1c concentrations of underfilled and appropriately filled blood collection tubes. Materials and methodsTo compare HbA1c concentrations, blood samples were collected into 2 mL tubes containing K3-EDTA from 109 subjects. Two blood samples (underfilled and appropriately filled) were drawn from a patient by the same personnel and materials. HbA1c measurements were assayed on a Cobas 6000 analyser module c 501 (Roche Diagnostics, Mannheim, Germany). The HbA1c% results were compared by t-test and Wilcoxon’s signed-rank statistical methods (SPSS Inc., Chicago, USA). Bias analysis was performed using Microsoft Excel 4.0. ResultsUnderfilled samples were classified three groups (group 1, N = 44; group 2, N = 36; and group 3, N = 29) according to the filling ratio of the samples; 0.5 mL and below ( 50%), respectively. When we compared underfilled tubes with pairing filled tubes, there was a statistically significant difference only with tubes filled less than 25% (P = 0.030). Furthermore, we have done bias analysis between paired tubes according to the diagnostic cut-off value of 6.5%. The bias was more prominent in up to 50% underfilled blood tubes (1.1%), when HbA1c concentrations were below the diagnostic cut-off of 6.5%. ConclusionsWe suggest that the blood tubes with EDTA for HbA1c measurement should be filled with at least 50% to avoid clinical variations