Comments on event driven animation

Event driven animation provides a general method of describing controlling values for various computer animation techniques. A definition and comments are provided on genralizing motion description with events. Additional comments are also provided about the implementation of twixt

The male to female ratio at birth following the Scottish Independence Referendum, September 2014

Human male live births exceed female live births by approximately 3%. This sex ratio is conventionally expressed as M/F (male divided by total live births). Many factors have been implicated as influencing this ratio, such as stress. This phenomenon occurred following the Quebec sovereignty referendum of 1995. This study was carried out in order to ascertain whether the Scottish referendum of September 2014 had any effect on the M/F ratio in Scotland. Monthly live births by gender for Scotland were obtained from Scottish Office of National Records for the period January 2004 to July 2015. They were analysed for any significant period changes as witnessed in Quebec in 1995. There were 661166 total births (338850 male and 322316 female births), with an overall M/F of 0.5125 (95% CI: 0.5113-0.5137). There were no changes in M/F in the first five months after the referendum. However, there was a non-significant rise in M/F toward the end of 2014 which continued during much of 2015. The rise in M/F reached its peak in May-June 2015, 8-9 months after the referendum (M/F 0.5199 compared to M/F of 0.5124 for aggregated May-June values 2004-14). There was no significant drop in M/F in the Scottish population in relation to the Scottish referendum. This may be due to a type 2 error since this study was less powered (12 times smaller) than the Quebec study. The non-significant rise may have potentially been caused by increased coital rates as observed after the birth of Prince William in 1982 and for Hong Kong in relation to Dragon years. It will be interesting to analyse the rest of the UK data when this becomes officially available.peer-reviewe

Gendercide : a review of the missing women

The term gendercide was first coined in 1985 and refers to the deliberate extermination of persons of a particular sex. The notion and its potential consequences had been conceived as far back as 1793, when the Marquis Nicolas de Condorcet had speculated “what might be [the effect] on humankind [of] the discovery of a means of producing a male or female child according to the will of the parents [...]. Supposing that this is likely to become a common practice, [...] would it [not] lead to [changes] in the social relations of human beings, whose consequences could be harmful to the peaceable development of that indefinite perfectibility with expectations of which we have flattered humankind?”peer-reviewe

Terrorist attacks and the male to female ratio at birth : the bombings of Madrid (3/2004) and London (7/2005)

Introduction: Males are usually in excess of females at birth and the ratio is often expressed as M/F (male divided by total births). Several factors have been shown to be associated with changes in M/F, including major terrorist attacks. These are associated with a transient lowering of M/F for a one month period, three to five months after such events. This study was carried out in order to ascertain whether the Madrid March 2004 bombings and the London July 2005 bombings were similarly associated with changes in M/F in their respective populations. Methods: Monthly live births by gender for Madrid and Spain for 2004 and for England and Wales for 2005 were obtained from the two countries’ National Statistics Offices. Results: There were no significant dips in M/F for any of the months following the March 2004 bombings in Madrid or in Spain. There were no significant dips in M/F for any of the months following the July 2005 London bombings. Discussion: Research to date has shown M/F dips following catastrophic or tragic events, including major terrorist actions with extensive media coverage. Equivalent dips were not noted in this study for the terrorist acts in these instances. The reasons for this may be one or a combination of the following. The population size was not sufficiently large in order to detect an M/F dip. Alternatively, the events were not felt to be sufficiently momentous by the populace such that an M/F dip was not produced. Yet another possibility is that these particular populations are somehow hardier and more resistant to such influences. Not all terrorist events universally cause a significant reduction in M/F.peer-reviewe

The male to female ratio at birth

The factors that influence the male to female ratio at birth are legion. Males are usually born in excess and stress decreases the ratio while wellbeing and good health tends to increase it. This paper reviews the multitudes of factors that have been implicated as affecting this ratio, from historical times to date.peer-reviewe

Impact of Cosmic Variance on the Galaxy-Halo Connection for Lyman-α\alpha Emitters

In this paper we study the impact of cosmic variance and observational uncertainties in constraining the mass and occupation fraction, $f_{\rm occ}$, of dark matter halos hosting Ly-$\alpha$ Emitting Galaxies (LAEs) at high redshift. To this end, we construct mock catalogs from an N-body simulation to match the typical size of observed fields at $z=3.1$ ($\sim 1 {\rm deg^2}$). In our model a dark matter halo with mass in the range $M_{\rm min}<M_{\mathrm h}<M_{\rm max}$ can only host one detectable LAE at most. We proceed to explore the parameter space determined by $M_{\rm min}$,$M_{\rm max}$ and $f_{\rm occ}$ with a Markov Chain Monte-Carlo algorithm using the angular correlation function (ACF) and the LAEs number density as observational constraints. We find that the preferred minimum and maximum masses in our model span a wide range $10^{10.0}h^{-1}{\rm{M_{\odot}}}\leq M_{\rm min} \leq 10^{11.1}h^{-1}{\rm{M_{\odot}}}$ , $10^{11.0}h^{-1}{\rm{M_{\odot}}}\leq M_{\rm max} \leq 10^{13.0}h^{-1}{\rm{M_{\odot}}}$; followed by a wide range in the occupation fraction $0.02\leq f_{\rm occ} \leq 0.30$. As a consequence the median mass, $M_{50}$, of all the consistent models has a large uncertainty $M_{50} = 3.16^{+9.34}_{-2.37}\times 10^{10}$$h^{-1}{\rm{M_{\odot}}}$. However, we find that the same individual models have a relatively tight $1\sigma$ scatter around the median mass $\Delta M_{1\sigma} = 0.55^{+0.11}_{-0.31}$ dex. We are also able to show that \focc\ is uniquely determined by $M_{\rm min}$, regardless of $M_{\rm max}$. We argue that upcoming large surveys covering at least $25$ deg$^{2}$ should be able to put tighter constraints on $M_{\rm min}$ and $f_{\rm occ}$ through the LAE number density distribution width constructed over several fields of $\sim 1$ deg$^{2}$.Comment: 7 Pages, 5 figures. Accepted for publication in Ap

Spark Ignition Measurements in Jet A: part II

An improved system for measuring the ignition energy of liquid fuel was built to perform experiments on aviation kerosene (Jet A). Compared to a previously used system (Shepherd et al. 1998), the present vessel has a more uniform temperature which can be held constant for long periods of time. This ensures thermal equilibrium of the liquid fuel and the vapor inside the vessel. A capacitive spark discharge circuit was used to generate damped sparks and an arrangement of resistors and measurement probes recorded the voltage and current histories during the discharge. This permitted measurement of the energy dissipated in the spark, providing a more reliable, quantitative measure of the ignition spark strength. With this improved system, the ignition energy of Jet A was measured at temperatures from 35C to 50C pressures from 0.300 bar (ambient pressure at 30 kft) to 0.986 bar (ambient pressure near sea level), mass-volume ratios down to 3 kg/m^3, with sparks ranging from 10 mJ to 0.3 J. Special fuel blends with flash points (Tfp) from 29C to 73.5C were also tested. The statistical properties of the ignition threshold energy were investigated using techniques developed for high-explosive testing. Ignition energy measurements at 0.585 bar with high mass-volume ratios (also referred to as mass loadings) showed that the trend of the dependence of ignition energy on temperature was similar for tests using the stored capacitive energy and the measured spark energy. The ignition energy was generally lower with the measured spark energy than with the stored spark energy. The present ignition energy system was capable of clearly resolving the difference in ignition energy between low and high mass-volume ratios. The ignition energy vs. temperature curve for 3 kg/m^3 was shifted approximately 5C higher than the curve for high mass-volume ratios of 35 kg/m^3 or 200 kg/m^3. The ignition energy was subsequently found to depend primarily on the fuel-air mass ratio of the mixture, although systematic effects of the vapor composition are also evident. As expected, the ignition energy increased when the initial pressure was raised from 0.585 bar to 0.986 bar, and decreased when the pressure was decreased to 0.3 bar. Finally, tests on special fuels having flash points different from that of commercial Jet A showed that the minimum ignition temperature at a spark energy of about 0.3 J and a pressure of 0.986 bar depends linearly on the flash point of the fuel

Molecular dynamics simulations of the interactions of potential foulant molecules and a reverse osmosis membrane

Reverse osmosis (RO) is increasingly one of the most common technologies for desalination worldwide. However, fouling of the membranes used in the RO process remains one of the main challenges. In order to better understand the molecular basis of fouling the interactions of a fully atomistic model of a polyamide membrane with three different foulant molecules, oxygen gas, glucose and phenol, are investigated using molecular dynamics simulations. In addition to unbiased simulations, umbrella sampling methods have been used to calculate the free energy profiles of the membrane-foulant interactions. The results show that each of the three foulants interacts with the membrane in a different manner.It is found that a build up of the two organic foulants, glucose and phenol, occurs at the membrane-saline solution, due to the favourable nature of the interaction in this region, and that the presence of these foulants reduces the rate of flow of water molecules over the membrane-solution interface. However, analysis of the hydrogen bonding shows that the origin of attraction of the foulant for the membrane differs. In the case of oxygen gas the simulations show that a build up of gas within the membrane is likely, although, no deterioration in the membrane performance was observed