Moisture movement in bulk stockpiles

Both drainage and evaporation are possible mechanisms for moisture loss in iron-ore and coal stockpiles. Some simple models are used to study both these mechanisms for various stages of stockpiling. The process of segregation of different particle sizes of the ore as it is stockpiled is also considered and this may have important implications for both drainage and evaporative moisture loss

Tear film thickness variations and the role of the tear meniscus

A mathematical model is developed to investigate the two-dimensional variations in the thickness of tear fluid deposited on the eye surface during a blink. Such variations can become greatly enhanced as the tears evaporate during the interblink period.\ud The four mechanisms considered are: i) the deposition of the tear film from the upper eyelid meniscus, ii) the flow of tear fluid from under the eyelid as it is retracted and from the lacrimal gland, iii) the flow of tear fluid around the eye within the meniscus and iv) the drainage of tear fluid into the canaliculi through the inferior and superior puncta.\ud There are two main insights from the modelling. First is that the amount of fluid within the tear meniscus is much greater than previously employed in models and this significantly changes the predicted distribution of tears. Secondly the uniformity of the tear film for a single blink is: i) primarily dictated by the storage in the meniscus, ii) quite sensitive to the speed of the blink and the ratio of the viscosity to the surface tension iii) less sensitive to the precise puncta behaviour, the flow under the eyelids or the specific distribution of fluid along the meniscus at the start of the blink. The modelling briefly examines the flow into the puncta which interact strongly with the meniscus and acts to control the meniscus volume. In addition it considers flow from the lacrimal glands which appears to occurs continue even during the interblink period when the eyelids are stationary

Life stage and resistance effects in modelling phosphine fumigation of Rhyzopertha dominica (F.)

Resistance to phosphine in insect pests of stored grain is a serious problem and there is a world-wide need for the development of sustainable resistance management strategies. Here we introduce results from a new mathematical model of resistance development that includes all life stages, rates of oviposition, natural mortality and mortality under fumigation in relation to resistant genotype. The example we discuss is phosphine resistance in the lesser grain borer, Rhyzopertha dominica where resistance is known to be controlled by two major genes that are close to recessive in expression, so that resistance is not fully expressed unless both resistant genes are present and homozygous. An example of a scenario where this model could be used concerns the repeat application of phosphine in a situation where control of all life stages has not been achieved. We determined a critical interval within which a second fumigation must occur to stop a rapidly recovering population of resistant genotypes. Such scenarios can be readily investigated using this approach to provide the grain industry with resistance management options and strategies. Keywords: Rhyzopertha dominica, Population dynamics, Stored wheat, Phosphine fumigant, Low concentratio

Inherent and learnt abilities for relative pitch in the vibrotactile domain using the fingertip

This paper reports experimental results concerning relative pitch discrimination. This is defined as the ability to distinguish one musical note as being higher or lower than another. Seventeen participants with normal hearing undertook a pitch discrimination experiment using the fingertip over a 16 session training period with a full baseline test before and after the training sessions. Two sinusoidal tones were presented, each of Is duration separated by a Is gap. A total of 24 tones were chosen to cover 12 intervals ranging from a semi-tone to an octave over the frequency range C3 to B4. The results show a high success rate for relative pitch discrimination with and without training. For intervals of 4 to 12 semitones, the success rates were >70% with or without the 16 training sessions. As a result of training, a significant improvement was found for individual intervals between 9 and 12 semitones when comparing the number of correct responses between pre-training and post-training tests. Comparison of pre- and post-training tests also showed an appreciable and significant improvement for the whole group of 12 intervals. In addition, reaction times to identify relative pitch tended to decrease over the training period

Corrigendum: The Gambian Bone and Muscle Ageing Study: Baseline Data From a Prospective Observational African Sub-Saharan Study.

[This corrects the article on p. 219 in vol. 8, PMID: 28912754.]

Influence of intergenerational in utero parental energy and nutrient restriction on offspring growth in rural Gambia.

The prenatal environment can alter an individual's developmental trajectory with long-lasting effects on health. Animal models demonstrate that the impact of the early life environment extends to subsequent generations, but there is a paucity of data from human populations on intergenerational transmission of environmentally induced phenotypes. Here we investigated the association of parental exposure to energy and nutrient restriction in utero on their children's growth in rural Gambia. In a Gambian cohort with infants born between 1972 and 2011, we used multiple regression to test whether parental season of birth predicted offspring birth weight (n = 2097) or length (n = 1172), height-for-age z score (HAZ), weight-for-height z score (WHZ), and weight-for-age z score (WAZ) at 2 yr of age (n = 923). We found that maternal exposure to seasonal energy restriction in utero was associated with reduced offspring birth length (crude:-4.2 mm, P = 0.005; adjusted: -4.0 mm, P = 0.02). In contrast, paternal birth season predicted offspring HAZ at 24 mo (crude: -0.21, P = 0.005; adjusted: -0.22, P = 0.004) but had no discernible impact at birth. Our results indicate that periods of nutritional restriction in a parent's fetal life can have intergenerational consequences in human populations. Fetal growth appears to be under matriline influence, and postnatal growth appears to be under patriline intergenerational influences.-Eriksen, K. G., Radford, E. J., Silver, M. J., Fulford, A. J. C., Wegmüller, R., Prentice, A. M. Influence of intergenerational in utero parental energy and nutrient restriction on offspring growth in rural Gambia