A new look at the modified Coulomb potential in a strong magnetic field

The static Coulomb potential of Quantum Electrodynamics (QED) is calculated in the presence of a strong magnetic field in the lowest Landau level (LLL) approximation using two different methods. First, the vacuum expectation value of the corresponding Wilson loop is calculated perturbatively in two different regimes of dynamical mass $m_{dyn.}$, {\it i.e.}, $|{\mathbf{q}}_{\|}^{2}|\ll m_{dyn.}^{2}\ll |eB|$ and $m_{dyn.}^{2}\ll |\mathbf{q}_{\|}^{2}|\ll|eB|$, where $\mathbf{q}_{\|}$ is the longitudinal components of the momentum relative to the external magnetic field $B$. The result is then compared with the static potential arising from Born approximation. Both results coincide. Although the arising potentials show different behavior in the aforementioned regimes, a novel dependence on the angle $\theta$ between the particle-antiparticle's axis and the direction of the magnetic field is observed. In the regime $|{\mathbf{q}}_{\|}^{2}|\ll m_{dyn.}^{2}\ll |eB|$, for strong enough magnetic field and depending on the angle $\theta$, a qualitative change occurs in the Coulomb-like potential; Whereas for $\theta=0,\pi$ the potential is repulsive, it exhibits a minimum for angles $\theta\in]0,\pi[$.Comment: V1: 26 pages, 8 figures, latex format, V2: Accepted for publication in PRD (2007

A model for evaluation of faculty members� activities based on meta-evaluation of a 5-year experience in medical school

Background: There is a global interest for deploying faculty members� activities evaluation systems, however implementing a fair and reliable system is a challenging issue. In this study, the authors devised a model for evaluation of faculty members� activities with regard to their viewpoints and meta-evaluation standards. Materials and Methods: The reliability of the current faculty members� activities metrics system was investigated in Medical School of Tehran University of Medical Sciences in 2014. Then authors conducted semi-structured interviews regarding meta-evaluation standards and designed a questionnaire based on interviews� results which were delivered to faculty members. Finally, they extracted the components of the model regarding interviews� content analysis and questionnaire�s factor analysis and finalized them in a focus group session with experts. Results: Reliability of the current system was 0.99 (P < 0.05). The final model had six dimensions (mission alignment, accuracy, explicit, satisfaction, appropriateness, and constructiveness) derived from factor analysis of the questionnaire and nine factors (consensus, self-reporting, web-based system, evaluation period, minimum expectancies, analysis intervals, verifiers, flexibility, and decision making) obtained via qualitative content analysis of the interviews. Conclusion: In this study, the authors presented a model for faculty members� activities evaluation based on meta-evaluation of the existing system. The model covered conceptual and executive aspects. Faculty members� viewpoints were the core component of this model, so it would be acceptable in a medical school to use the model for evaluating their activities. © 2015 Journal of Research in Medical Sciences

GenoMetric Query Language: A novel approach to large-scale genomic data management

Motivation: Improvement of sequencing technologies and data processing pipelines is rapidly providing sequencing data, with associated high-level features, of many individual genomes in multiple biological and clinical conditions. They allow for data-driven genomic, transcriptomic and epigenomic characterizations, but require state-of-the-art ‘big data’ computing strategies, with abstraction levels beyond available tool capabilities. Results: We propose a high-level, declarative GenoMetric Query Language (GMQL) and a toolkit for its use. GMQL operates downstream of raw data preprocessing pipelines and supports queries over thousands of heterogeneous datasets and samples; as such it is key to genomic ‘big data’ analysis. GMQL leverages a simple data model that provides both abstractions of genomic region data and associated experimental, biological and clinical metadata and interoperability between many data formats. Based on Hadoop framework and Apache Pig platform, GMQL ensures high scalability, expressivity, flexibility and simplicity of use, as demonstrated by several biological query examples on ENCODE and TCGA datasets. Availability and implementation: The GMQL toolkit is freely available for non-commercial use at http://www.bioinformatics.deib.polimi.it/GMQL/. Contact: [email protected] Supplementary information: Supplementary data are available at Bioinformatics online

Voltage control in distributed generation systems based on complex network approach

In this paper, a new approach for modeling of voltage control problem in distributed generation systems based on the complex network theory is proposed. Distributed generationsystems (DGS) including renewable energy sources are highly complex nonlinear dynamical systems by nature. There are many theoretical and practical challenges to apply the existing control technologies to them. The novel approach, introduced in this paper, embeds the complex network theory into the voltage control problem of DGS; i.e. the voltage control of DGS is introduced as a synchronization problem in complex networks. Complex network methodology shows a promising simplification inthe analysis as well as timely response in large-scale systems. Thanks to the well-developed graph theory as well as advancements in control of multi-agent systems,the model presented in this paper, candealwith real-time hierarchical multi-objective requirements of control problems in DGS. Finally, the pinning control approach is applied to the model in order to solve the voltage synchronization problem of the microgrid

Sensitivity study of mirror energy differences in positive parity bands of T= 32 A=45 nuclei

Symmetry-conserving density-functional theory (DFT) based no-core-configuration-interaction framework (DFT-NCCI) is an excellent tool for precision calculation of diverse (pseudo-)observables related to isospin symmetry breaking from elusive isospin impurities through isospin corrections to superallowed beta decays to mirror- and triplet-displacement energies and mirror energy differences (MED) along rotational bands. In our recent work [Phys. Rev. C 106, 024327 (2022)2469-998510.1103/PhysRevC.106.024327] we performed axial DFT-NCCI calculations and failed to reproduce a sign of MED in positive-parity (π=+) bands of Sc45/Cr45, T=3/2 mirror pair what casts a shadow on credibility of the model. In this work we aim to perform a thorough analysis of this case with the focus on sensitivity of our predictions with respect to (i) low-energy constants (LECs) of our effective contact charge symmetry breaking force and (ii) nuclear shape. We demonstrate, among other things, that inclusion of triaxial π=+ ground state - which is actually the global π=+ minimum in our unconstrained mean-field calculation - in the DFT-NCCI calculations instead of the axial one used before leads to MED which are consistent with experimental data concerning both their sign as well as magnitude without any need for fine-tuning of the model's LECs

Study of measuring Tilapia (Oreochromis niloticus) freshness using quality index method (QIM)

Fish freshness by using QIM and according to scoring to all of parts variable (positive and negative) was by sensory method and finally become the parameters of quantitative and qualitative with statistical analysis is based, tables used in volatility score of 0 to 23, with a score of 0 to 3 respectively, for their excellent quality, 3 to 7good, from 7 to 10 and from 10 to above average evaluation is unacceptable. In this study to measure the freshness of fish species Nile Tilapia (Oreochromis niloticus), black and red in 4 treatments, whole fish and empty stomach is considered and the objective of this study was to calculate the survival rate of fish in ice cover practically immediately after harvest to measure qualitative factors (sensory evaluation, chemical and microbiological).For this study 50 pieces of red and 50 pieces black Tilapia after weighed, washed and then selection 25 pieces for each treatment in unlit, ratio of 3 to 1 (ice - fish) was covered .The mean (± SD) change in temperature the fish flesh during study were between 0.2 ±0.07 a to 0.3 ±0.1a degrees Celsius, that need to raise the quality temperature is maintained at 0 degrees Celsius in unlit center. Fish covered with ice keep at ambient temperature, and after measuring the change free nitrogen, pH and microbial tests, the results showed maximum shelf life of whole fish in ice cover 9 and for empty stomach fish was7 days .And also statistical analysis (Duncan test) of data between treatments (Whole and empty fish covered in ice ) was significant (P<0.05)