The multi-wavelength polarization of Cygnus X-1

Polarization measurements of the microquasar Cygnus X-1 exist at gamma-ray, X-ray, UV, optical and radio frequencies. The gamma-ray emission has been shown to be highly linearly polarized. Here, we present new infrared polarimetric data of Cygnus X-1 taken with the 10.4-m Gran Telescopio Canarias and the 4.2-m William Herschel Telescope. We show that the broadband, radio to gamma-ray flux spectrum and polarization spectrum in the hard state are largely consistent with a simple phenomenological model of a strongly polarized synchrotron jet, an unpolarized Comptonized corona and a moderately polarized interstellar dust component. In this model, the origin of the gamma-ray, X-ray and some of the infrared polarization is the optically thin synchrotron power law from the inner regions of the jet. The model requires the magnetic field in this region to be highly ordered and perpendicular to the axis of the resolved radio jet. This differs to studies of some other X-ray binaries, in which the magnetic field is turbulent, variable and aligned with the jet axis. The model is able to explain the approximate polarization strength and position angle at all wavelengths including the detected X-ray (3 - 5 keV) polarization, except the observed position angle of the gamma-ray polarization, which differs to the model by ~ 60 degrees. Past numerical modelling has shown that a curved synchrotron spectrum can produce a shift in position angle by ~ 60 degrees, which may account for this.Comment: Accepted in MNRA

Anatomical Variations of Radial Artery-Its Morphology and Clinical Implications

Background: The radial artery is the smaller terminal branch of the brachial artery. It is one of the most commonly used arteries for various interventions. Anatomical variations exist and can predispose patients to iatrogenic injury if the operator is unaware of normal radial artery morphology. The present study focuses on giving detailed information about radial artery measurements in our local population. Methods: This was a cross-sectional observational study, conducted in the anatomy department of Jinnah Medical College Peshawar from 2017 to 2018. This study was conducted on 42 formalin-fixed cadavers, yielding 84 upper limbs. The radial artery was dissected and studied; length, external and internal diameters were measured. Data was entered in SPSS v20 and analyzed. Results: The mean age of the study population was 36 ± 11.25. Male to female ratio was 1:1. The most common site of origin of the radial artery was distal to head of the radius. The right radial artery was longer than the left. The right radial artery was broader in males as compared to females with a p-value of <0.05. The external and internal diameters of the radial artery decreased gradually from start to the endpoint for both the genders. The external diameters of the left radial artery were greater than those on the right side. The right radial artery had a larger internal diameter than the left side. Conclusion: The anatomy and morphology of radial artery have many documented variations. Radiologist and surgeons should have a good understanding of normal morphological variations of radial artery

Capital Markets and Foreign Ownership Restrictions: An Empirical Analysis of Emerging Stock Markets

In the 1990s, the hot issue in international finance was the growing interest of portfolio managers in the emerging stock markets. The interest in the emerging markets gained rapid attention, which is evident from the global trends, towards the opening up of economies and financial markets, free capital flow and the privatisation of financial institutions. Earlier the emerging markets were isolated due to several factors that had posed serious problems for international investors. These markets lacked the depth, regulatory framework, and structural safeguards that had characterised the equity markets in the developed world. Capital markets are called integrated, if assets with perfectly correlated rates of returns have the same price regardless of the location in which they are traded. Alternatively, capital market are called segmented, if financial assets traded in different markets “with identical risk characteristics” have different returns due to different investment restrictions.1 Segmentation may be due to individuals’ attitudes, government restrictions over capital movements or irrationality. In the past twenty-five years, modern finance theory has proved to be a major development in finance, which comprises of portfolio theory, capital market theory and efficient market theory. These modern developments can be traced back to the work of Markowitz (1959); Sharpe (1964); Solnik (1974) etc., which assumes that security prices fully reflect all publicly available information. Due to this information, potential investors can gain benefits through international diversification. The major attraction of forming international portfolios lies in the potential for risk reduction through diversification of unsystematic risk.

Economic Growth and Income Inequality Relationship: Role of Credit Market Imperfection

This paper examines the empirical relationship between economic growth and income inequality both at aggregate and regional level using more comparable data set for 69 developing countries over the period 1965-2003. The study identifies credit market imperfection in low-income developing countries as the likely reason for a strong negative relationship between income inequality and economic growth. While in short run the relationship between growth and income inequality might be positive but over time more income inequalities reduces economic growth. Moreover, this paper finds evidence that more physical and human capital investment, openness to trade and higher government spending have statistically significant impact on enhancing economic growth and reducing inequality.Economic Growth, Income Inequality, Poverty, Credit Market Imperfection, Trade Openness

Identifying Factors Playing Important Role in the Increasing Employees’ Turnover Rate: A Case of Telecom Industry in Pakistan Patterns in Neighboring Areas

The objective of this study is to know about the practices of Telecom industry, regarding their employees and to know how they keep up with the intense competition in the industry. The study focuses on factors effecting employees’ turnover and those that factors play an important role in retaining the employees of Telecom industry. The universe of this study was all the employees of Telecom industry in Islamabad, Karachi and Lahore. For this purpose survey method was used by using questionnaire as a tool for data collection. The results have shown that Salary, Working environment and Benefits are three significant factors effecting employees’ turnover and correlated with each other. The study was faced by certain limitations, which include time constraints and resources constraints, which limit this research to only Islamabad, Karachi and Lahore offices of the organizations in telecom industry of Pakistan. The present study found support for an independent variable with Employees turnover. Significant negative correlations have been found for the Salary, Work environment and Benefits. Therefore, organizations need to focus on how to develop better Salary plan and reduce strain in the workplace. If staff voluntarily leaves, it is a great loss to the telecom industry. It is expensive to hire, train, and “bring up to speed” new replacements. It is, therefore, important to understand the antecedents of turnover intent of employees before they decide to quit.Employee’s Turnover, Telecom Industry; Pakistan; Factors.

Symmetries of the Energy-Momentum Tensor: Some Basic Facts

It has been pointed by Hall et al. [1] that matter collinations can be defined by using three different methods. But there arises the question of whether one studies matter collineations by using the ${\cal L}_\xi T_{ab}=0$, or ${\cal L}_\xi T^{ab}=0$ or ${\cal L}_\xi T_a^b=0$. These alternative conditions are, of course, not generally equivalent. This problem has been explored by applying these three definitions to general static spherically symmetric spacetimes. We compare the results with each definition.Comment: 17 pages, accepted for publication in "Communications in Theoretical Physics