346 research outputs found
The association between the fraternal birth order effect in male homosexuality and other markers of human sexual orientation
Later fraternal birth order (FBO) is a well-established correlate of homosexuality in human males and may implicate a maternal immunization response in the feminization of male sexuality. This has led to the suggestion that FBO may relate to other markers of male sexual orientation which are robustly sexually dimorphic. If so, among homosexual males the number of older brothers should strongly correlate with traits such as spatial ability and psychological gender, indicative of greater behavioural feminization, compared to heterosexual males. The present study failed to find significant associations between number of older brothers and these traits
Some Coefficient Estimates for Polynomials on the Unit Interval
2000 Mathematics Subject Classification: 26C05, 26C10, 30A12, 30D15, 42A05, 42C05.In this paper we present some inequalities about the moduli of the coefficients of polynomials of the form f (x) : = еn = 0nan xn, where a0, ј, an О C. They can be seen as generalizations, refinements or analogues of the famous inequality of P. L. Chebyshev, according to which |an| Ј 2n-1 if | еn = 0n an xn | Ј 1 for -1 Ј x Ј 1
The Schwarz-Pick theorem and its applications
Various derivative estimates for functions of exponential type in a half-plane are proved in this paper. The reader will also find a related result about functions analytic in a quadrant. In addition, the paper contains a result about functions analytic in a strip. Our main tool in this study is the Schwarz-Pick theorem from the geometric theory of functions. We also use the Phragmen-Lindelof principle, which is of course standard in such situations
The Extended Evolutionary Synthesis and the role of soft inheritance in evolution
In recent years, a number of researchers have advocated extending the modern synthesis in evolutionary
biology. One of the core arguments made in favour of an extension comes from work on soft inheritance
systems, including transgenerational epigenetic effects, cultural transmission and niche construction. In
this study, we outline this claim and then take issue with it. We argue that the focus on soft inheritance
has led to a conflation of proximate and ultimate causation, which has in turn obscured key questions
about biological organization and calibration across the life span to maximize average lifetime inclusive
fitness. We illustrate this by presenting hypotheses that we believe incorporate the core phenomena of
soft inheritance and will aid in understanding them
Which Pairs of Stocks should we Trade? Selection of Pairs for Statistical Arbitrage and Pairs Trading in Karachi Stock Exchange
Pairs Trading refers to a statistical arbitrage approach
devised to take advantage from short term fluctuations simultaneously
depicted by two stocks from long run equilibrium position. In this study
a technique has been designed for the selection of pairs for pairs
trading strategy. Engle-Granger 2-step Cointegration approach has been
applied for identifying the trading pairs. The data employed in this
study comprised of daily stock prices of Commercial Banks and Financial
Services Sector. Restricted pairs have been formed out of highly liquid
log share price series of 22 Commercial Banks and 19 Financial Services
companies listed on Karachi Stock Exchange. Sample time period extended
from November 2, 2009 to June 28, 2013 having total 911 observations for
each share prices series incorporated in the study. Out of 231 pairs of
commercial banks 25 were found cointegrated whereas 40 cointegrated
pairs were identified among 156 pairs formed in Financial Services
Sector. Furthermore a Cointegration relationship was estimated by
regressing one stock price series on another, whereas the order of
regression is accessed through Granger Causality Test. The mean
reverting residual of Cointegration regression is modeled through the
Vector Error Correction Model in order to assess the speed of adjustment
coefficient for the statistical arbitrage opportunity. The findings of
the study depict that the cointegrated stocks can be combined linearly
in a long/short portfolio having stationary dynamics. Although for the
given strategy profitability has not been assessed in this study yet the
VECM results for residual series show significant deviations around the
mean which identify the statistical arbitrage opportunity and ensure
profitability of the pairs trading strategy. JEL classifications: C32,
C53, G17 Keywords: Pairs Trading, Statistical Arbitrage, Engle-Granger
2-step Cointegration Approach, VECM
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