Total hip arthroplasty in the horse: Overview,technical considerations and case report

A total hip arthroplasty was performed in a small equine patient with a history of traumatic subluxation of the coxofemoral joint during infancy resulting in severe degenerative changes to the femoral head and acetabulum. The transtrochanteric surgical approach used to expose the joint, as well as the technique and technology to replace the joint, is described. The patient was weightbearing within 24 h of surgery and walking successfully without sling support 4 days post operatively. On the fifth post operative day, the patient abruptly deteriorated and succumbed to multiple pulmonary thromboemboli and a jejunal infarction. Despite the systemic complications in this case, the initial short‐term success of this treatment option indicate its potential to be considered in the management of equine coxofemoral joint disease/lesions.     

Influence of Immunization Procedures on Upper Respiratory Tract Immunity in Cattle

Aspects of respiratory tract immunity have been investigated in the bovine species. Using Past. hemolytica type I as the antigen for this model the relationship of nasal and serum antibody production to the route of vaccination and type of vaccine was investigated in a series of 15 dairy calves from two to four months of age. Experimental results indicated that an aerosol vaccination with live Past. hemolytica resulted in a significant nasal antibody response while parenterally vaccinated gave calves with equivalent serum titers had no significant nasal antibody response.     

Delineating a managed fire regime and exploring its relationship to the natural fire regime in East Central Florida,USA: A remote sensing and GIS approach

A managed fire regime on John F. Kennedy Space Center, Florida and surrounding federal properties was mapped using time series satellite imagery and GIS techniques. Our goals were to: (1) determine if an image processing technique designed for individual fire scar mapping could be applied to an image time series for mapping a managed fire regime in a rapid re-growth pyrogenic system; (2) develop a method for labeling mapped fire scar confidence knowing a formal accuracy analysis was not possible; and (3) compare results of the managed fire regime with regional information on natural fire regimes to look for similarities/differences that might help optimize management for persistence of native fire-dependent species. We found that the area burned by managed fire peaked when the drought index was low and was reduced when the drought index was high. This contrasts with the expectations regarding the natural fire regime of this region. With altered natural fire regimes and fire-dependent species declining in many pyrogenic ecosystems, it is important to manage fire for the survival of fire-adapted native species. The remote sensing and GIS techniques presented are effective for delineating and monitoring managed fire regimes in shrub systems that grow rapidly and may be appropriate for other fire-dependent systems world wide.     

Genetic diversity of European populations of the oak fine‐root pathogen Phytophthora quercina

The recently discovered oak‐specific fine root plant pathogen Phytophthora quercina is a significant factor in the current phase of European oak decline but its origins and ecology are poorly understood. A genome‐wide analysis of 260 amplified fragment length polymorphism (AFLP) markers was used to examine the genetic diversity of 72 isolates from five oak species at 28 sites in Germany (particularly Bavaria), Italy, France, Hungary and the UK. Within‐site diversity was examined at 16 sites. The limited genetic diversity (within and between sites) and lack of genetic substructuring according to geographic origin or host species suggest the rapid spread of a relatively recently introduced species. Two subgroups were distinguished and these may reflect an initial introduction of isolates of two different genetic backgrounds. The relatively low genetic diversity is probably because of the predominantly inbreeding (homothallic) nature of P. quercina. However, evidence of limited intra‐site diversity, temporal variation and the lack of clonality within the European population suggest that some diversity is being maintained by occasional outcrossing and turnover of a reservoir of long‐lived soil‐borne oospore (sexually derived) inoculum.     

Retention of native woody vegetation on farms in Australia: management considerations,planning guidelines and information gaps

Australia's forests and woodlands have been extensively cleared since European settlement. Cropping regions have the least retained native vegetation, with the greatest depletion of forests and woodlands being observed in Western Australia and South Australia. Salinisation, erosion and landslides have resulted from excessive clearing and inappropriate tree removal from particular units within the landscape. Major problems in cropping regions are the dramatic reduction in total woody cover and the fragmentation of retained vegetation into isolated remnant patches which tend to be very small (<10–15 ha). Those states with little remnant vegetation have legislation which restricts further clearing and the main emphasis is on managing remnant patches for conservation. For those states with a large proportion of woody vegetation uncleared, the main priority is to ensure that past mistakes are not repeated and that any vegetation clearance is based upon sound ecological principles.Throughout Australia, the condition of the remaining vegetation is of great concern and management guidelines for both conservation and production are being sought. Clearing may lead directly to soil erosion, but often the cause of erosion is inappropriate post-clearing management. Overgrazing is a major cause of vegetation and soil degradation, particularly in semi-arid regions.An understanding of the complex inter-relationship between woody vegetation, grazing and fire is necessary if 1) flora and fauna are to be conserved; 2) hydrological balance is to be maintained; and 3) rural industries are to remain viable. Planning at the catchment level is necessary to implement strategies to meet conservation and hydrological goals. Within that framework, individual property planning must include consideration of the area of native woody vegetation to be retained and its configuration. In many cases, the purpose of retention will influence the decisions of where and how native vegetation should be retained.     

Evaluation of risk factors for Cryptococcus gattii infection in dogs and cats

OBJECTIVE: To determine risk factors associated with Cryptococcus gattii infection in dogs and cats residing on Vancouver Island in British Columbia, Canada. DESIGN: Matched case-control study. ANIMALS: 20 dogs and 29 cats with C gattii infection and matched controls. PROCEDURE: Dogs and cats with a confirmed or probable diagnosis of cryptococcosis resulting from infection with C gattii were enrolled by veterinarians, and owners completed a questionnaire designed to obtain information pertaining to potential risk factors for the disease. Owners of matched control animals were also interviewed. Odds ratios and 95% confidence intervals or paired t tests were calculated to determine significant associations. RESULTS: Animals were enrolled during 2 noncontiguous periods in August 2001 to February 2002 (8 dogs and 9 cats enrolled) and May to December 2003 (12 dogs and 20 cats enrolled). Risk factors significantly associated with development of cryptococcosis included residing within 10 km of a logging site or other area of commercial soil disturbance, above-average level of activity of the animal, travelling of the animal on Vancouver Island, hunting by the animal, and owners hiking or visiting a botanic garden. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that dogs and cats that were active or that lived near a site of commercial environmental disturbance had a significantly increased risk of developing C gattii infection. Veterinarians should communicate these risks to owners in context because cryptococcosis was an uncommon disease in this population.     

Effects of climate and site characteristics on Scots pine growth

Scots pine is a highly diverse species, extended across Europe from Scandinavia to Spain, Italy, Greece and Turkey. It is also a valuable species, used in many commercial monoculture plantations in Great Britain and particularly in Scotland. Because of the diversity of growing environments and its commercial importance, it is necessary to identify the combination of significant factors affecting the observed variability of growth. Temperature, mainly during the growing season, is quite commonly considered as the most important factor in knowledge-based or empirical models. However, in highly oceanic climates like that of Scotland, the impact of temperature may have a less significant impact on growth. Here we argue that other factors, such as incoming winter solar radiation, frost, drought and management also have a significant effect on the growth of Scots pine. In addition, we argue that the already developed Ecological Site Classification knowledge-based model, used as a forest management tool in Great Britain, should be updated to incorporate our findings. Furthermore, we discuss the need to include management impact and possibly more physiological based components in its growth modelling routines, as these would allow the introduction of the effect of winter solar radiation.     

A noninvasive optical system for the measurement of xylem and phloem sap flow in woody plants of small stem size

Over the past 70 years, heat has been widely used as a tracer for estimating the flow of water in woody and herbaceous plants. However, most commercially available techniques for monitoring whole plant water use are invasive and the measurements are potentially flawed because of wounding of the xylem tissue. The study of photosynthate transport in the phloem remains in its infancy, and little information about phloem transport rates is available owing to the fragility of the vascular tissue. The aim of our study was to develop a compact, stand-alone non-invasive system allowing for direct detection of phloem and xylem sap movement. The proposed method uses a heat pulse as a tracer for sap flow. Heat is applied to the surface of the stem with a near-infrared laser source, and heat propagation is monitored externally by means of an infrared camera. Heat pulse velocities are determined from the thermometric data and related to the more useful quantity, mass flow rate. Simulation experiments on the xylem tissue of severed silver birch (Betula pendula Roth.) branch segments were performed to assess the feasibility of the proposed approach, highlight the characteristics of the technique and outline calibration strategies. Good agreement between imposed and measured flow rates was achieved leading to experimentation with live silver birch and oak (Quercus robur L.) saplings. It was demonstrated that water flow through xylem vessels can be monitored non-invasively on an intact stem with satisfactory accuracy despite simultaneous sugar transport in the phloem. In addition, it was demonstrated that the technique allows for unequivocal detection of phloem flow velocities.