SOLUBILITY OF ALUMINIUM IN SOILS OF THE HUMID TROPICS

Soil samples obtained from genetic horizons of an upland and acid sulphate soil of Sierra Leone, were equilibrated with 0.01 M CaCI using a 1:2 soil to solution ratio. Al³⁺ activity was estimated from total Al measured in the equilibrium extract, by accounting for hydrolysis and the formation of other complex species. The Al³⁺ activity was pH-dependent, but the Al(OH)³ ion product was I'airly constant throughout the upland soil profile; Al³⁺ activity was near that expected for equilibrium with kaolinite and quartz. In the acid sulphate soil alunite appeared to control the activity of Al³⁺.     

A new design for a seed germinator with 100 independently temperature controlled cells

Design and performance of a 100-cell seed germinator capable of simultaneously generating 100 different diurnal temperature cycles with extremes lying between 0 and 45°C is discussed. Each individual cell is equipped with a separate electronic temperature controller employing a thermistor for temperature sensing. The set temperature for each cell is determined by a precision reference resistor in the controller circuit. Six different reference resistors corresponding to six different temperatures are provided for each cell. The reference resistors are mounted on plug-in modules with one module for each cell. Heating or cooling of the individual cells is provided by thermoelectric heat pumps. Temperature cycling, which approximates a sine function, is achieved by switching the six reference resistors, one at a time, into the controller circuits at appropriate times during a 24h period. Each cell is designed to accept a standard 100 mm Petri dish to contain the seeds. The cells have glass covers to allow entry of light essential for germination of some species. The benefit of using this type of germinator to assess the germination response of Alyssum alyssoides L., Artemisia absinthium L., Euphorbia esula L. and Setaria viridis (L.) Beauv., is discussed. Three dimensional germination response surfaces are given for the four species.     

Evaluation of semen from individual male domestic fowl by assessment of sperm perivitelline interaction in vitro and in vivo

1. Spermatozoa in semen samples from 8 individual male domestic fowls were shown to have a differential and characteristic ability to hydrolyse holes in the inner perivitelline layer from laid eggs in an in vitro assay. 2. The number of holes produced by samples of spermatozoa per unit area of inner perivitelline layer in vitro was linearly correlated with sperm ATP content ( r = 0.85) and motility (r=0.76). 3. The number of holes formed in the inner perivitelline layer in vitro was also linearly correlated with the numbers of holes formed in the inner perivitelline layer of eggs fertilised in vivo , in inseminated hens (r=0.90); and was correlated logarithmically with the proportion of fertile eggs laid by these hens.     

Microsurgery: An Update for the Veterinary Profession

The history of microsurgery is reviewed and the development of instruments and suture materials briefly described. The implementation of microsurgical techniques to the human operating theater is detailed and the potential role of microtechniques in veterinary surgery projected.     

IMAGING DIAGNOSIS—SPINAL CORD CHONDROSARCOMA ASSOCIATED WITH SPIROCERCOSIS IN A DOG

A 7‐year‐old neutered female Boerboel cross was examined for progressive left pelvic limb lameness. There was no left patellar reflex but the remaining pelvic limb reflexes were hyperreflexic. Radiographically, there was a poorly mineralized opacity occupying the intervertebral foramen at L4–L5. On computed tomography images there was a hyperattenuating intramedullary lesion at L4–L5 that continued caudally, lateralized to the left and became extramedullary, terminating at L5–L6. In addition, well marginated, hyperattenuating lesions were noted at two muscular sites. The dog underwent euthanasia and a caudal esophageal mass was found at post mortem examination. The tumors in the spinal cord, the esophagus, and the skeletal muscles were diagnosed histologically as low‐grade chondrosarcoma undergoing endochondral ossification. Spirocerca lupi‐induced esophageal chondrosarcoma was believed to be the primary site from which the other, presumably metastatic, lesions originated.     

Filaroides osieri infection in the dog

The biology of F. osleri and its pathogenic effects in dogs are reviewed. The diagnosis treatment and prophylaxis of the infestation are described.     

Rectal and Colonic Injury in the Llama Anatomic Considerations and Surgical Management in Four Llamas

Transrectal palpation in llamas can result in iatrogenic rectal and colonic injury. The purpose of this report is to define the caudal extent of the peritoneal cavity in llamas and to describe the surgical management of rectal or colonic injuries in four llamas. Measurements were made of six adult llamas during necropsy. The mean distance from the peritoneal reflection to the anus was 3.9 ± 0.1 cm (3.4 - 4.3 cm). Four llamas were examined for rectal or colonic perforations. One laceration was of partial thickness and three lacerations were of full thickness. Two of the defects were repaired by a transanal approach and two by celiotomy to facilitate removal of fecal debris and abdominal lavage. Successful repair of the rectal or colonic tears was achieved in all four llamas. Wound infection and incisional hernia occurred in both llamas that underwent celiotomy. Two llamas died 3 and 18 months later, and two llamas have survived 2 years. Rectal tears in llamas are accompanied by a high risk of peritoneal contamination, and primary closure is recommended. If fecal contamination of the abdomen has occurred, celiotomy is indicated to allow mechanical removal of fecal debris and peritoneal lavage.     

The Impact of State and Local Tax and Expenditure Limitations on State Economic Growth

Employing a unique index of Tax and Expenditure Limitation (TEL) restrictiveness, we estimate a family of economic growth models using a panel of the 50 U.S. states for the period 1969 to 2005. Our central goal is to assess the relationship between TEL restrictiveness and economic growth. Results suggest that stronger TELs imposed on state governments have a dampening effect on state economic growth and TELs imposed on local governments have a weak negative impact on growth. The results do not support the argument that legislatures can use tax and expenditure limits as a mechanism to promote economic growth.     

Sacroiliac Luxation in the Cat: Defining a Safe Corridor in the Dorsoventral Plane for Screw Insertion in Lag Fashion

Objective— To define a safe corridor in the dorsoventral plane within the feline sacral body for placement of screws inserted in lag fashion for repair of sacroiliac luxation.
Study Design— Anatomic study.
Sample Population— Frozen cadaveric feline sacra.
Methods— Feline sacra (n=20) were used to perform a radiographic study to define a safe corridor to a depth of 66% of the sacral body width. Two drill start points (A and B) were evaluated. Dorsal exit from the safe corridor was considered unacceptable.
Results— Forty safe corridors were measured. The mean articular surface was 100±6.4° from horizontal. Mean maximum, optimum, and minimum safe corridor drill angles from drill point A were 107±6.8°, 97±6.9°, and 87±7.2°, respectively, from the articular surface. Mean maximum, optimum, and minimum angles from drill point B were 109±7.2°, 99±7.1°, and 89.5±7.2°, respectively. Point B increased the risk of ventral exit from the sacral body.
Conclusions— Point A and a drill angle of 90±4° for drilling of the feline sacral body is recommended. This margin for error risks ventral exit from the body in 23/40 (58%) of the sacra in this study. Reduction of the margin for error to ±2° would reduce the risk of ventral exit to 14/40 (35%) of the sacra in this study.
Clinical Relevance— Drilling at 90° to the feline sacral articular surface is recommended. Findings from this study present a strong case for use of angled drill guides.