The formation of glycocyamine in man and its urinary excretion

Glycocyamine was first isolated from human and dog urine and identified by Weber (1-3). He supported the view that glycocyamine is a normal precursor of creatine and that its appearance in urine (2) is “an overflow phenomenon of an intermediate metabolic product ...” He expressed no views on the mechanism of its formation

Finding a Mate With No Social Skills

Sexual reproductive behavior has a necessary social coordination component as willing and capable partners must both be in the right place at the right time. While there are many known social behavioral adaptations to support solutions to this problem, we explore the possibility and likelihood of solutions that rely only on non-social mechanisms. We find three kinds of social organization that help solve this social coordination problem (herding, assortative mating, and natal philopatry) emerge in populations of simulated agents with no social mechanisms available to support these organizations. We conclude that the non-social origins of these social organizations around sexual reproduction may provide the environment for the development of social solutions to the same and different problems.Comment: 8 pages, 5 figures, GECCO'1

On the Reification of Global Constraints

We introduce a simple idea for deriving reified global constraints in a systematic way. It is based on the observation that most global constraints can be reformulated as a conjunction of pure functional dependency constraints together with a constraint that can be easily reified. We first show how the core constraints of the Global Constraint Catalogue can be reified and we then identify several reification categories that apply to at least 82% of the constraints in the Global Constraint Catalogue

The host-range tdCE phenotype of Chandipura virus is determined by mutations in the polymerase gene

The emerging arbovirus Chandipura virus (CV) has been implicated in epidemics of acute encephalitis in India with high mortality rates. The isolation of temperature-dependent host-range (tdCE) mutants, which are impaired in growth at 39 °C in chick embryo (CE) cells but not in monkey cells, highlights a dependence on undetermined host factors. We have characterized three tdCE mutants, each containing one or more coding mutations in the RNA polymerase gene and two containing additional mutations in the attachment protein gene. Using reverse genetics, we showed that a single amino acid change in the virus polymerase of each mutant was responsible for the host-range specificity. In CE cells at the non-permissive temperature, the discrete cytoplasmic replication complexes seen in mammalian cells or at the permissive temperature in CE cells were absent with the tdCE mutants, consistent with the tdCE lesions causing disruption of the replication complexes in a host-dependent manner

Vegetation Changes in Sown Grassland in the UK after Nine Years of Extensive Grazing Management

The effect of extensive grazing management with sheep on vegetation change in sown pastures (initially containing Lolium perenne and Trifolium repens) in the uplands of Scotland was investigated from 1990-1999. One treatment was representative of current more intensive management systems; it was fertilized, and maintained at a sward surface height of 4 cm. Two treatments were unfertilized and were maintained at sward surface heights of 4 cm or 8 cm; the ewe numbers carried on these treatments averaged 74% and 44%, respectively, of those on the fertilized treatment. In all treatments the sheep were Scottish Blackface ewes. Their single lambs also grazed from May until weaning in mid-August. Over 9 years there were only small changes in species composition in the unfertilized treatments. The changes were primarily shifts in abundance of the species present initially, with only a few additions or losses of species. L. perenne made a similar contribution to cover in both the 8 cm and fertilized swards. The highest content of T. repens was in unfertilized swards and the least was in the 4 cm fertilized swards. This study demonstrates that the contribution of the sown species to sward composition remains high in grazed upland swards that are more extensively managed for nearly ten years. Since there was little overall change in species composition, it could be difficult to achieve increased plant biodiversity in these systems simply by removing fertiliser and reducing grazing intensity

The Generation And Properties Of Solid Monodisperse Aerosols Of Stearic Acid And Carnauba Wax

A monodisperse aerosol generator (MAGE) was used to generate calibration or monodisperse aerosols containing stearic acid and carnauba wax. Some of the factors affecting the size of aerosol particles generated with the MAGE were determined. The factors include: temperature of operation of the MAGE, type and purity of coating material used. The reproducibility of aerosol particles and stability of the aerosol generated were evaluated. The performance characteristics of the MAGE over an extended period of time of operation were also established. The calibration aerosols generated with the MAGE can be used in situ for studies of aerosol deposition measurement equipment. Keywords: Generation, Calibration aerosols, Monodisperse aerosol generator, Performance characteristic

Penetration of human skin by the cercariae of Schistosoma mansoni : an investigation of the effect of multiple cercarial applications

It has previously been postulated that L-arginine emitted by penetrating Schistosoma mansoni cercariae serves as an intraspecific signal guiding other cercariae to the penetration site. It was suggested that penetrating in groups offers a selective advantage. If this hypothesis is correct and group penetration at one site on the host offers an advantage, it would follow that at such a site, successive groups of cercariae would be able to penetrate skin in either greater numbers or at a faster rate. This prediction was tested by the use of an in vitro model of cercarial penetration based on the Franz cell and using human skin. It was demonstrated that there was no increase in the percentage of cercariae able to penetrate the skin with subsequent exposures. Consequently, it seems unlikely that the release of L-arginine by cercariae during penetration could have evolved as a specific orientation system based on a selective advantage offered by group penetration.Peer reviewe

A Computational Interpretation of Context-Free Expressions

We phrase parsing with context-free expressions as a type inhabitation problem where values are parse trees and types are context-free expressions. We first show how containment among context-free and regular expressions can be reduced to a reachability problem by using a canonical representation of states. The proofs-as-programs principle yields a computational interpretation of the reachability problem in terms of a coercion that transforms the parse tree for a context-free expression into a parse tree for a regular expression. It also yields a partial coercion from regular parse trees to context-free ones. The partial coercion from the trivial language of all words to a context-free expression corresponds to a predictive parser for the expression

Investigation of the Use of Erasures in a Concatenated Coding Scheme

A new method for declaring erasures in a concatenated coding scheme is investigated. This method is used with the rate 1/2 K = 7 convolutional code and the (255, 223) Reed Solomon code. Errors and erasures Reed Solomon decoding is used. The erasure method proposed uses a soft output Viterbi algorithm and information provided by decoded Reed Solomon codewords in a deinterleaving frame. The results show that a gain of 0.3 dB is possible using a minimum amount of decoding trials

An evaluation of the efficiency of personal information as embodied in a personal history record as a means of predicting academic success at the college freshman level.

Thesis (Ed.D.)--Boston University