CHANGES IN THE PHYSICAL AND CHEMICAL PROPERTIES OF A MINERAL TOPSOIL UNDER THE INFLUENCE OF PEAT DEBRIS

Changes are reported of particle size distribution, organic carbon and nitrogen values, cation exchange capacity and exchangeable cation populations, and in iron and aluminium patterns as a result of adding varying rates of acid peat debris to a mineral topsoil. Up to 3 cm of peat had beneficial effects on soil chemical and physical properties but 5 to 8 cm was sufficient to cause considerable acidification, release of Fe and other ions from primary minerals and the development of an iron seam (or pan) which contains up to 7 per cent free iron. Greater thickness of peat (up to 30 cm) caused soil reaction to drop to pH 4 or less and produced so much humic acids as to inhibit iron precipitation and to facilitate its removal from the profiles. The effects of soil moisture on the pattern of peat humification in the deeper additions (20–30 cm) are also outlined.     

Transport of gases through hemoglobin solution

A mathematical theory is developed to explain the observed enhancement of oxygen transport through solutions by hemoglobin. At high partial pressures of oxygen, ordinary diffusion through the solvent accounts for all transport of oxygen, but at low partial pressures the transport may be increased many fold by the presence of hemoglobin. This phenomenon is explained and the possible role of this phenomenon in living organisms is discussed. The theory also indicates a new method of determining dissociation curves from diffusion experiments.     

A long-snouted predatory dinosaur from africa and the evolution of spinosaurids

Fossils discovered in Lower Cretaceous (Aptian) rocks in the Tenere Desert of central Niger provide new information about spinosaurids, a peculiar group of piscivorous theropod dinosaurs. The remains, which represent a new genus and species, reveal the extreme elongation and transverse compression of the spinosaurid snout. The postcranial bones include blade-shaped vertebral spines that form a low sail over the hips. Phylogenetic analysis suggests that the enlarged thumb claw and robust forelimb evolved during the Jurassic, before the elongated snout and other fish-eating adaptations in the skull. The close phylogenetic relationship between the new African spinosaurid and Baryonyx from Europe provides evidence of dispersal across the Tethys seaway during the Early Cretaceous.     

Cementless Total Hip Replacement in an Alpaca

Objective— To report management of a chronic slipped capital femoral epiphysis (SCFE) in an alpaca using cementless total hip replacement (THR).
Study Design— Case report.
Animal— An 18-month-old, 47 kg alpaca male.
Methods— Cementless THR was performed in an alpaca with a chronic, right SCFE, and secondary osteoarthritis. Force plate gait analysis was performed before and 8 weeks after surgery. Outcome was determined through clinical evaluation, radiography, and force plate gait analysis.
Results— Cementless THR resulted in marked improvement in the alpaca's comfort level, degree of lameness, and range of motion. On preoperative force plate gait analysis there was decreased contact time ( P =.01) and vertical impulse ( P <.01) of the affected limb, whereas at 8 weeks postoperatively significant differences in gait analysis between pelvic limbs were not apparent.
Conclusion— THR using a BioMedtrix^® canine cementless modular prosthesis restored hip function in an alpaca with coxofemoral osteoarthritis from chronic SCFE.
Clinical Relevance— THR may be an appropriate treatment for selected traumatic and degenerative conditions of the coxofemoral joint in alpacas.     

Is there an association between ossification of the cartilages of the foot and collateral desmopathy of the distal interphalangeal joint or distal phalanx injury?

Reasons for performing study: Associations between degree of ossification of the cartilages of the foot and injuries to other structures of the foot have been suggested, but have not been investigated by large scale studies. Objectives: To describe the frequency of grade >3 ossification of the cartilages of the foot (possibly significant ossification, PSO), mediolateral symmetry of ossification and left‐right symmetry between feet; and to investigate associations between PSO and injury of either the collateral ligaments (CLs) of the distal interphalangeal (DIP) joint or the distal phalanx. Hypotheses: Possibly significant ossification of the cartilages of the foot is associated with CL and distal phalanx injury. Distal phalanx injury is associated with a mediolateral difference in ossification grade of ≥2. Methods: Horses were examined for lameness localised to the foot by perineural analgesia, and underwent radiographic and magnetic resonance imaging examinations. Age, breed, occupation, duration of lameness, lame(st) limb, primary cause of lameness, and presence or absence of CL injury were recorded. Dorsopalmar (dorsoplantar) radiographs were examined and ossification of the cartilages of the foot graded using a modification of a previously published scale. Results: One foot from each of 462 horses was included for analysis. There was left‐right symmetry of ossification between feet, and significant association between grades of each foot, with lateral ≥medial cartilages. Possibly significant ossification occurred in the maximally ossified cartilage in 59 (12.8%) feet. There were significant associations between PSO of the maximally ossified cartilage of the foot and injuries of both the CLs of the DIP joint and the distal phalanx. There was no association between distal phalanx injury and marked asymmetry of the ossified cartilages of the foot. Conclusions and clinical relevance: Extensively ossified cartilages of the foot are significantly associated with CL or distal phalanx injury. Markedly asymmetric ossification did not increase the likelihood of distal phalanx injury and should be considered at a prepurchase examination.