Statistical spring wheat yield forecasting for the Canadian prairie provinces

A study to forecast regional spring wheat (Triticum aestivum L.) yields on the Canadian Prairies was conducted, based on simulated daily water use and soil water contents derived from the National Drought Model. Empirical linear regression models were calibrated from 1976 to 2006 spring wheat yield data for this purpose. Potential predictors assessed were mainly those indicators related to water stress conditions at different crop growth stages. Stepwise regression and cross-validation were employed for the selection of the predictors in multivariate linear regression models used for forecasting spring wheat yields from seeding to harvest. The cross-validated “forecasts” for 1976–2006, using data up to harvest, explained 77%, 64%, 63% and 70% of yield variances, respectively, for Alberta, Saskatchewan, Manitoba and the entire Prairie region. Root mean squared error of the “forecasts” ranged from 8% to 11% of the average yields. The prediction accuracy earlier in the season was often lower than later in the season. Usable prediction accuracy was found by the middle of the growing season (around heading or anthesis), but only marginally effective at seeding time, especially so for Saskatchewan.     

Analysis of weight uniformity, content uniformity and 30-day stability in halves and quarters of routinely prescribed cardiovascular medications

Objectives

Congenital and acquired cardiac disorders are frequently diagnosed in small breed dogs and cats. In order to appropriately dose cardiovascular drugs for small patients, fractions of commercially available tablets must be prescribed. The aims of this study were to evaluate weight and content uniformity and 30-day chemical stability in halves and quarters of 11 drug formulations commonly prescribed to treat cardiovascular disorders in small breed dogs and cats.

Animals, materials and methods

Fifteen tablets from 11 drug formulations were obtained within the same lot. Tablets were split by a single operator using a commercially available pill splitter. Whole tablets, halves and quarters were weighed and stored in plastic containers. High-pressure liquid chromatography or liquid chromatography with mass spectrometry were utilized to determine drug content and repeated 30 days later to estimate chemical stability.

Results

Statistically significant weight variability, content non-uniformity and chemical degradation were found for some formulations. Digoxin showed a significant degradation that should be considered in clinical practice.

Conclusions

It appears that pill splitting is overall a relatively reliable practice; however tablets should not be split ahead of time but only immediately prior to intended usage.     

Septic peritonitis in a Percheron mare associated with Clostridium haemolyticum

This report describes an 11‐year‐old Percheron mare that presented with signs of colic and was ultimately diagnosed with bacterial peritonitis of unknown origin. Bacterial culture of a peritoneal fluid sample isolated 2 Clostridial species, one of which was strongly suspected to be Clostridium haemolyticum. The horse was markedly hypoalbuminaemic at presentation, leading to the development of low oncotic pressure and ventral oedema. The mare was administered a low molecular weight/low molar substitution hydroxyethyl starch solution in conjunction with other therapies that resulted in marked improvement of clinical signs. The purpose of this report is to describe the clinical findings associated with equine peritonitis associated with C. haemolyticum, a rarely identified pathogen in the horse. Secondly, this report serves to describe the beneficial effects of tetrastarch administration in a clinical case with severe hypoalbuminaemia and ventral oedema.     

Applying molecular genetic tools to tiger conservation

The utility of molecular genetic approaches in conservation of endangered taxa is now commonly recognized. Over the past decade, conservation genetic analyses based on mitochondrial DNA sequencing and microsatellite genotyping have provided powerful tools to resolve taxonomy uncertainty of tiger subspecies, to define conservation units, to reconstruct phylogeography and demographic history, to examine the genetic ancestry of extinct subspecies, to assess population genetic status non-invasively, and to verify genetic background of captive tigers worldwide. The genetic status of tiger subspecies and populations and implications for developing strategies for the survival of this charismatic species both in situ and ex situ are discussed.     

Diviner Lunar Radiometer observations of cold traps in the Moon's south polar region

Diviner Lunar Radiometer Experiment surface-temperature maps reveal the existence of widespread surface and near-surface cryogenic regions that extend beyond the boundaries of persistent shadow. The Lunar Crater Observation and Sensing Satellite (LCROSS) struck one of the coldest of these regions, where subsurface temperatures are estimated to be 38 kelvin. Large areas of the lunar polar regions are currently cold enough to cold-trap water ice as well as a range of both more volatile and less volatile species. The diverse mixture of water and high-volatility compounds detected in the LCROSS ejecta plume is strong evidence for the impact delivery and cold-trapping of volatiles derived from primitive outer solar system bodies.     

Tuber age as a contributory factor in the water relations of potato (solanum tuberosum L.)

Seed tuber age effects on the response of potato plants (cv Alpha) to different drought stress regimes during the pre-tuberization period were evaluated. During a slow drying cycle of approximately 2 weeks’ duration, young expanding leaves on plants grown from young or old seed tubers showed no evidence of osmotic adjustment and pre-stressing the plants did not affect this situation. Pre-stressed plants from young and old tubers possessed a higher relative water content at a zero turgor potential than unstressed plants. However, tuber age did not affect significantly the relative water content at zero turgor potential. Plants derived from young seed tubers exhibited improved drought resistance such as reduced water loss from mature leaves, a larger root/shoot dry weight ratio and possible effects on root distribution in soil.     

Evaluation of a breast support conveyor to improve poultry welfare on the shackle line

A breast support conveyor has the potential to improve bird welfare by avoiding the need to invert and suspend broilers by their legs as they move from the point of shackling to entry into the electric waterbath. To evaluate its effect on welfare under commercial conditions, a breast support conveyor was installed under the conventional shackle line of a small poultry processing plant. A structured assessment of the behaviour of the birds indicated a significant decrease in struggling and wing flapping at the point of shackling, on the straight conveyor and at entry into the waterbath. This resulted in a lower prevalence of red wing tips and bruising in the first wing joint. The shackle line and conveyor in this installation, however, passed around a 90° corner, which appeared to cause more disturbance to the birds on the conveyor than to comparable birds suspended from shackles in the traditional manner. The results indicate that a breast support conveyor has the potential to improve bird welfare on straight shackle lines and that, because struggling activity and duration following shackling are reduced, the time between shackling and stunning could also be reduced using this method, further improving bird welfare. Breast support conveyors should not be used when the shackle lines have sharp bends.