A case of true hermaphroditism presenting as an undescended testicle

A case of true hermaphroditism in a 20-year-old Motswana who was brought up as a male, is reported. He presented with left-sided undescended testicle and inguinal hernia. At operation an ovary, uterus and fallopian tube were found instead of a left testicle. Chromosome analysis revealed a karyotype, 46, XX in tissue culture and peripheral blood. Epithelial nucleii in buccal smears were chromatin-positive, indicating the presence of 2 X chromosomes.S. Afr. Med. J., 48, 1540 (1974)

Predicting gaze direction from head pose yaw and pitch

Abstract - Socially assistive robots (SARs) must be able to interpret non-verbal communication from a human. A person’s gaze direction informs the observer where the visual attention is directed to. Therefore it is useful if a robot can interpret the gaze direction, so that it can assess whether a person is looking at it or some object in the environment. Gazing is a combination of head and eye movement, but detecting eye orientation from a distance is difficult in real life environments. Instead a robot can measure the head pose and infer the gaze direction. In this paper, we show that both the yaw and pitch of a human’s gaze can be inferred from the measured yaw and pitch of the human’s head pose with simple linear equations

A rigorous evaluation of crossover and mutation in genetic programming

The role of crossover and mutation in Genetic Programming (GP) has been the subject of much debate since the emergence of the field. In this paper, we contribute new empirical evidence to this argument using a rigorous and principled experimental method applied to six problems common in the GP literature. The approach tunes the algorithm parameters to enable a fair and objective comparison of two different GP algorithms, the first using a combination of crossover and reproduction, and secondly using a combination of mutation and reproduction. We find that crossover does not significantly outperform mutation on most of the problems examined. In addition, we demonstrate that the use of a straightforward Design of Experiments methodology is effective at tuning GP algorithm parameters

Geography but not alternative host species explain the spread of raccoon rabies virus in Vermont

In North America, the raccoon-associated variant of rabies virus (RRV) is of special concern, given its relatively rapid spread throughout the eastern USA and its potential public health impact due to high raccoon host densities in urban areas. Northward expansion of this epizootic included an outbreak in the Canadian province of Quebec in 2006–2009 due to trans-border spread from the State of Vermont. To inform a more proactive approach to future control efforts, this study uses phylogenetic analyses to explore the role of geography and alternative carnivore hosts in the dynamics of RRV spread within Vermont. Specifically, we sought to examine whether striped skunks, a species frequently infected by RRV, could be part of the maintenance host community. Whole genome sequencing of 160 RRV samples from Vermont and neighbouring US states were used for fine-scale phylogeographic analyses. Results, together with the complete surveillance record of raccoon rabies since its entry into Vermont in 1994, document incursions by two distinct viral lineages and identify topographical features of the landscape which have significantly influenced viral spread, resulting in a complex distribution pattern of viral variants throughout the state. Results of phylogenetic cluster analysis and discrete state reconstruction contained some evidence of skunk-to-skunk and skunk-to-raccoon transmission but overall failed to support a role for skunks as alternative maintenance hosts

Canola seed as affected by swathing time

Non-Peer ReviewedYield, weight, protein content (oil-free meal) and oil content of canola seed increased as seeds developed. Maximum values were obtained between 45-49 days after flowering, when seed moisture was 29-38%. Fatty acid composition of canola seed oil changed during seed development. The proportion of oleic (C18:1) and linolenic (C18:3) acids increased, while that of most other fatty acids decreased, as seeds developed, while Eicosenoic (C20:1) and erucic (C22:1) acids did not show a clear trend. Fatty-acids tended to stabilize by the 49th day after flowering. Early seeding resulted in higher seed yield, larger seeds, lower seed protein content and higher seed oil content, when compared to late seeding

The Formation of Fragments at Corotation in Isothermal Protoplanetary Disks

Numerical hydrodynamics simulations have established that disks which are evolved under the condition of local isothermality will fragment into small dense clumps due to gravitational instabilities when the Toomre stability parameter $Q$ is sufficiently low. Because fragmentation through disk instability has been suggested as a gas giant planet formation mechanism, it is important to understand the physics underlying this process as thoroughly as possible. In this paper, we offer analytic arguments for why, at low $Q$, fragments are most likely to form first at the corotation radii of growing spiral modes, and we support these arguments with results from 3D hydrodynamics simulations.Comment: 21 pages, 1 figur

Cluster Monte Carlo study of multi-component fluids of the Stillinger-Helfand and Widom-Rowlinson type

Phase transitions of fluid mixtures of the type introduced by Stillinger and Helfand are studied using a continuum version of the invaded cluster algorithm. Particles of the same species do not interact, but particles of different types interact with each other via a repulsive potential. Examples of interactions include the Gaussian molecule potential and a repulsive step potential. Accurate values of the critical density, fugacity and magnetic exponent are found in two and three dimensions for the two-species model. The effect of varying the number of species and of introducing quenched impurities is also investigated. In all the cases studied, mixtures of $q$-species are found to have properties similar to $q$-state Potts models.Comment: 25 pages, 5 figure