Drop-cone penetration in situ and on minimally disturbed soil cores

Drop-cone penetration was measured both in situ and on minimally disturbed cores at a selection of soil matric potentials for four soils. The drop-cone penetration/water content relation was linear in situ and, if results for very low water contents were excluded, for the cores. The slope of the line for the field data was much greater than for the core data and this raises doubts about the value of other than in situ measurements of soil strength for predicting field behaviour. Vane shear strength is negatively correlated with in situ drop-cone penetration. The drop-cone test is a useful strength test for small volumes of soil, but care must be taken in selecting the mass of the cone as this affects the volume of soil which will influence the test results.     

THE POTASSIUM STATUS OF SIX LOESSIAL SOILS OF CANTERBURY, NEW ZEALAND, IN RELATION TO RAINFALL AND RATE OF LOESS ACCUMULATION

A selection of greywacke-derived loessial soils in Canterbury, New Zealand, was examined to test the hypothesis that soil K status is a function of soil-forming factors. Soils were selected such that factors besides loess accumulation and rainfall were relatively constant and the effects of each variable could be isolated. Soil K status was evaluated by plant, chemical, and X-ray diffraction techniques. With increasing rainfall and decreasing rate of loess accumulation soil K status decreased; there was a concurrent decrease in illite and increase in interstratified mineral content of the clay fraction.     

Disease signs reported in south-eastern Australian dairy cattle while grazing Brassica species

Objective
To estimate the relative frequency of various disease signs in dairy cattle fed brassicas in south-eastern Australia, to estimate the incidence of disease signs within affected groups and to identify risk factors for commonly reported signs in brassica-fed dairy cows.
Design
A case series study and a case-control study.
Procedures
Case data was collected using an incident reporting system. Herd managers and veterinarians recorded details about disease incidents in brassica-fed dairy cattle in summer and autumn 1995 using a standard questionnaire. Potential risk factors for photosensitisation were assessed using a case-control study.
Results
Disease signs were reported in 66 groups of brassica-fed dairy cattle. Photosensitisation and bloat were the more frequently reported signs. While high incidences were reported in some groups, the incidence of disease signs was low within most affected groups. Photosensitisation occurred more frequently among groups of cows fed brassica crops treated with nitrogenous fertilisers or which were low yielding. Risks of other disease signs were greatest while the first one quarter of the crop was grazed.
Conclusions
In the study population, most disease outbreaks occurring in brassica-fed cattle were of low incidence. However, some high incidence outbreaks occurred. Results from this study suggest that important risk factors exist for disease signs in brassica-fed dairy cattle. Further studies are required if these risk factors are to be fully identified. This would allow the development of preventative strategies for high incidence disease outbreaks while feeding brassicas to dairy cattle.     

PLASTIC LIMIT DETERMINATION USING A DROP-CONE PENETROMETER

The drop-cone method, in which a 30° cone of mass 80 g is allowed to sink into a soil sample at a selection of moisture contents, was used to determine the moisture content/cone penetration curve in the region of the plastic limit for eighteen soils. The moisture content corresponding to the minimum of the curve is shown to be always numerically less than, but to correlate closely with, the plastic limit. It is suggested that the plastic limit be redefined as the moisture content corresponding to the minimum of the moisture content/cone penetration curve, with the advantages that the test is more closely related to soil behaviour, less subjective, at least as reproducible as the Casagrande test and may be carried out simultaneously with the liquid limit test.     

Intertarsal and tarso-metatarsal subluxation in the dog

Forty-four cases of intertarsal subluxation and eight cases of tarso-metatarsal subluxation in the dog are reported. The anatomical features of the hock related to these conditions are briefly considered. There was evidence that the Shetland Sheepdog is predisposed to intertarsal subluxation and in this breed minimal trauma was associated with the occurrence of the condition. The history, clinical and radiographic features are reported for each condition and the methods and results of treatment described.     

Unusual soft tissue orthopaedic problems in the dog

Single cases of supraspinatus and infraspinatus muscle contracture in working sheep-dogs are reported. Both cases showed characteristic abnormal forelimb posture and were successfully treated by complete section of the affected muscle. Three cases of anteromedial shoulder luxation with damage to the biceps brachii tendon are also described. In two of these the tendon was completely severed. The integrity of the biceps tendon is important in maintaining shoulder joint stability and should be inspected when surgical reduction of shoulder dislocations is carried out. Repair of the tendon, if severed, is important. Three cases of lameness associated with tendon displacement are considered i.e. slipping of the biceps brachii, long digital extensor and superficial digital flexor tendons. In two cases the displacement was prevented by the insertion of mattress wire sutures to form a 'lid' over the tendon.     

Epiblast Cell Number and Primary Embryonic Stem Cell Colony Generation Are Increased by Culture of Cleavage Stage Embryos in Insulin

Human embryos for hESC derivation are often donated at the cleavage stage and of reduced quality. Poor quality embryos have lower efficiency for hESC derivation. However, cleavage stage mouse embryos develop into higher quality expanded blastocysts if they are cultured with insulin, suggesting that this approach could be used to improve hESC derivation from poor quality cleavage stage embryos. The present study used a mouse model to examine this approach. In particular we examined the effect of insulin on the number of epiblast cells in blastocysts on days 4, 5 and 6 using Oct4 and Nanog co-expression. Second we examined the effect of insulin on the frequency with which outgrowths can be derived from these. Finally, we tested whether prior culture in the presence of insulin results in blastocysts with increased capacity to generate ESC colonies. Culture of cleavage stage embryos with insulin increased the number of Oct4 and Nanog positive cells in blastocysts at all time points examined. Prior culture with insulin had no effect on outgrowths generated from blastocysts plated on days 4 or 5. However, insulin treatment of blastocysts plated on day 6 resulted in increased numbers of outgrowths with larger epiblasts compared with controls. 13% of insulin treated day 6 blastocysts produced primary ESC colonies compared with 6% of controls. In conclusion, treatment with insulin can improve epiblast cell number in mice leading to an increase with which primary ESC colonies can be generated and may improve hESC isolation from reduced quality embryos donated at the cleavage stage.     

Prevalence of and Risk Factors for Postoperative Ileus after Small Intestinal Surgery in Two Hundred and Thirty-Three Horses

Objectives— To determine the incidence of postoperative ileus (POI) in a population of horses after small intestinal surgery and the effect of multiple variables on development of POI.
Study Design— Case series.
Animals— Horses (n=233) aged ≥1 year that had exploratory celiotomy for small intestinal disease that recovered from surgery from 1995 to 2005.
Methods— Sixty-eight variables were collected from medical records (1995–2005) for each horse. POI was defined as nasogastric reflux volume >20 L over 24 hours or >8 L at any single time after surgery.
Results— Twenty-seven percent (64/233) of horses developed POI; 29 of 64 (46%) horses with POI had duodenitis proximal jejunitis (DPJ). When no intestinal resection was required at surgery, excluding horses with DPJ, 15% of horses had POI; 30% horses had POI after intestinal resection. Ten percent of horses had POI for >24 hours. When horses with DPJ were excluded, factors associated with increased risk of POI included high packed cell volume at hospital admission ( P =.024), increasing age ( P =.0004), and length of intestinal resection ( P =.05).
Conclusions— Risk factors for POI in this study were nonspecific although horses with intestinal resection are at higher risk compared with horses without intestinal resection.
Clinical Relevance— Predicting with certainty which cases will develop POI remains elusive.