If you build it,they will learn: A review of models in veterinary surgical education

Surgical skills are learned through deliberate practice, and veterinary educators are increasingly turning to models for teaching and assessing surgical skills. This review article sought to compile and review the literature specific to veterinary surgical skills models, and to discuss the themes of fidelity, educational outcomes, and validity evidence. Several literature searches using broad terms such as “veterinary surgery model,” “veterinary surgical model,” and “veterinary surgical simulator” were performed using PubMed, CAB abstracts, and Google scholar. All articles describing a model created and utilized for veterinary surgical training were included. Other review articles were used as a source for additional models. Commercially available models were found using review articles, internet browser searches, and communication with veterinary clinical skills educators. There has been an explosion of growth in the variety of small animal surgical task trainers published in the last several decades. These models teach orthopedic surgery, ligation and suturing, open celiotomy and abdominal surgery, sterilization surgeries, and minimally invasive surgeries. Some models were published with accompanying rubrics for learner assessment; these rubrics have been noted where present. Research in veterinary surgical models is expanding and becoming an area of focus for academic institutions. However, there is room for growth in the collection of validity evidence and in development of models for teaching large animal surgery, training surgical residents, and providing continuing education to practitioners. This review can assist with evaluation of current surgical models and trends, and provide a platform for additional studies and development of best practices.     

Electrical migration of exogenous mineral ions through green sapwood ofPinus sylvestris L. (Scots pine)

Summary The electrical migration was studied of several cations passing longitudinally through cylindrical samples of green sapwood ofPinus sylvestris L. under the influence of an applied electric field. This led to values for the hindered ionic conductances within the wood of the cations Li⁺, K⁺ and CU²⁺ which were compared with data obtained previously (Simons et al., 1998) for several endogenous cations. There was satisfactory agreement for the conductance of the potassium ion, the only one to be determined by both methods. Copper ions were found to possess a higher conductance within the wood than calcium or magnesium, a factor relevant to its use as a wood preservative. Visual observation of the location of the blue-green colouration produced in the wood by copper ions indicated that they migrated via longitudinal resin ducts and tracheids. Elution and transport experiments were also carried out with sapwood which had been flushed with water, Li₂SO₄ or CuSO₄ solution.Symbols E potential gradient - F Faraday's constant (96, 494 C/mol) - I current - L length of wood sample - M molarity (mol/dm³) - Q quantity of electricity - R electrical resistance - S Siemens (reciprocal ohm) - t time - u ionic mobility (velocity under unit potential gradient) - v ionic velocity - z charge number of ion - ionic conductance The authors thank SERC and Rentokil PLC for the award of a CASE Research Studentship to P.J.S. and the Leverhulme Trust for the award of an Emeritus Fellowship to M.S.     

High differentiation among populations of the woody legume Sesbania sesban in sub-Saharan Africa: Implications for conservation and cultivation during germplasm introduction into agroforestry systems

Cultivation of the woody legume Sesbania sesban in agroforestry systems has been widely promoted for soil fertility improvement in Africa. Despite the existence of natural populations in eastern Zambia, considerable seed originating from Kenya has been introduced to the area, while further introductions from Malawi are planned. Large-scale anthropogenic seed dispersal raises concerns regarding genetic management, which were addressed here by random amplified polymorphic DNA (RAPD) analysis. Eleven populations of Sesbania from southern and East Africa were assessed, including S. sesban populations already or likely to be introduced into eastern Zambia and reference taxa. Seventeen primers revealed a very large number of polymorphisms (538) in surveyed material. Differentiation among S. sesban populations was unusually high for a woody perennial (70% of variation among populations), with all individuals stringently assigned to specific populations in cluster analysis, even for geographically proximate sites. High differentiation, combined with the unusually large number of polymorphisms determined, resulted in the identification of a number of population-diagnostic markers. High differentiation may reflect the restricted ecology of S. sesban, human disturbance and frequent natural fluctuations in niche availability. Hydrochory, posited as a mechanism for gene flow between populations located along the same drainage system, appears to be discounted. Geographic proximity was not always a good guide for genetic similarity among S. sesban populations. In particular, rather proximate populations from Zambia and Malawi appeared highly differentiated genetically, while Zambian populations were relatively similar to a geographically distant population from Namibia. Differentiation was consistent with the presence of two botanic varieties in the southern Africa region, vars. nubica and zambesiaca. Estimates of Nei's genetic diversity suggested that S. sesban populations from East Africa were most diverse. Overall, population diversity estimates were low, possibly due in part to frequent bottlenecks, short longevity and a short juvenile phase. The unusually large number of polymorphisms detected here provided an opportunity to test for data redundancy and primer selection methodologies during RAPD analysis. Combined data from a subset of eight primers selected according to three different approaches provided a very good overall fit to the complete data set (r_M > 0.95). Different primer selection approaches influenced the reliability of clustering and diversity analysis, with a minimum of eight primers required for reliable ranking of diversity estimates. The implications of our data for conservation, cultivation and monitoring of S. sesban in the southern Africa region are discussed. Caution is advised during the introduction of germplasm into eastern Zambia from both distant (Kenya) and relatively proximate (Malawi) sources.     

Ovarian Responses, Hormonal Profiles and Embryo Yields in Anoestrous Ewes Superovulated with Folltropin®-V after Pretreatment with Medroxyprogesterone Acetate-releasing Vaginal Sponges and a Single Dose of Oestradiol-17β

In ruminants, superovulatory treatments started at the time of follicular wave emergence result in greater and less variable ovulatory responses and embryo yields compared with the treatments begun in the presence of a large growing antral follicle(s) from the previous waves. The progesterone–oestradiol treatment is routinely used for follicular wave synchronization in cattle. The main objective of this study was to characterize the ovarian responses, hormonal profiles and in vivo embryo production in anoestrous Rideau Arcott ewes (May‐June), which were superovulated after pretreatment with medroxyprogesterone acetate (MAP)‐releasing intravaginal sponges and a single dose of oestradiol‐17β (E₂‐17β). Six days after insertion of MAP sponges, eight ewes were given an i.m. injection of 350 μg of E₂‐17β (E₂‐17β‐treated ewes); 10 ewes were given an i.m. injection of vehicle (control ewes). Multiple‐dose Folltropin®‐V treatment, followed by the bolus injection of GnRH (50 μg i.m.), began 6 days after E₂‐17β/vehicle injection. Transrectal ovarian ultrasonography revealed that: (i) the interval between E₂‐17β/vehicle injection and regression of all follicles ≥5 to 3 mm in diameter was shorter (p < 0.01; 2.6 ± 0.4 vs 4.8 ± 0.6 days respectively); and (ii) the interval between injection and emergence of the next follicular wave was longer (p < 0.05; 5.4 ± 0.3 vs 1.2 ± 0.4 days, respectively) in E₂‐17β‐treated than in control ewes. During the 6 days after injection, the mean FSH peak concentration and basal FSH concentration were lower (p < 0.01) in E₂‐17β‐treated ewes. The mean ovulation rate and the number of recovered embryos did not differ (p > 0.05) between the two groups of ewes. However, the number of luteinized unovulated follicles per ewe, and the variability in the number of luteal structures and overall embryo yield were less (p < 0.05) in E₂‐17β‐treated compared with control ewes. In conclusion, the MAP–E₂‐17β pretreatment significantly reduced the variability in ovarian responses and embryo yields, without affecting the embryo production in superovulated anoestrous ewes.     

Normalized burn ratios link fire severity with patterns of avian occurrence

Context

Remotely sensed differenced normalized burn ratios (DNBR) provide an index of fire severity across the footprint of a fire. We asked whether this index was useful for explaining patterns of bird occurrence within fire adapted xeric pine-oak forests of the southern Appalachian Mountains.

Objectives

We evaluated the use of DNBR indices for linking ecosystem process with patterns of bird occurrence. We compared field-based and remotely sensed fire severity indices and used each to develop occupancy models for six bird species to identify patterns of bird occurrence following fire.

Methods

We identified and sampled 228 points within fires that recently burned within Great Smoky Mountains National Park. We performed avian point counts and field-assessed fire severity at each bird census point. We also used Landsat? imagery acquired before and after each fire to quantify fire severity using DNBR. We used non-parametric methods to quantify agreement between fire severity indices, and evaluated single season occupancy models incorporating fire severity summarized at different spatial scales.

Results

Agreement between field-derived and remotely sensed measures of fire severity was influenced by vegetation type. Although occurrence models using field-derived indices of fire severity outperformed those using DNBR, summarizing DNBR at multiple spatial scales provided additional insights into patterns of occurrence associated with different sized patches of high severity fire.

Conclusions

DNBR is useful for linking the effects of fire severity to patterns of bird occurrence, and informing how high severity fire shapes patterns of bird species occurrence on the landscape.

     

Thermal burns of the spectacle associated with supplementary heating in native New Zealand geckos

ABSTRACT

Case history: Gradual onset of ocular opacity was observed in three gold-striped geckos (Woodworthia chrysosiretica), and five Pacific geckos (Dactylocnemis pacificus) held in two adjacent terrariums in a zoological institution located in the North Island of New Zealand. Ultraviolet light and heat had been provided for the previous 3–4 years by a fluorescent bulb, but in the last 4 weeks of winter a ceramic heat bulb had been added, situated 10?cm above the upper mesh of the cage

Clinical findings: All eight geckos presented with mostly bilateral lesions of varying severity confined to the central or upper quadrant of the spectacles. These lesions ranged from variable areas of opacity within the stroma of the spectacle to similarly distributed ulcers of the surface epithelium of both spectacles. The spectacle lesions in the Pacific geckos responded well to treatment with topical combined antimicrobial therapy, within 18–29 days. The gold-striped geckos suffered complications including dysecdysis, severe spectacle ulceration and perforation, mycotic spectaculitis, and widespread mycotic dermatitis resulting in death or leading to euthanasia.

Pathological findings: In the three gold-striped geckos, there were extensive areas of deep ulceration and replacement of the spectacle with a thick serocellular crust containing large numbers of fungal elements. The affected areas of the stroma were expanded by large deposits of proteinaceous and mucinous material, pyknotic cellular debris and moderate numbers of heterophils and macrophages as well as infiltrating fungal hyphae.

Diagnosis: Mycotic spectaculitis with ulceration and perforation, and disseminated mycotic dermatitis likely secondary to thermal burns.

Clinical relevance: This is the first report of thermal burns of the spectacle in any reptile. There was species variation in the burn severity with gold-striped geckos showing more severe lesions, possibly due to a mix of behavioural and anatomical factors. The thermal burns to the spectacles in three cases were complicated by delayed healing, perforation, dysecdysis and severe mycotic infection.     

Ustilago kamerunensis on Napier grass in Kenya

Napier or elephant grass, Pennisetum purpureum Schum., is the major source of fodder for stall-fed dairy cattle in Kenya. In the early 1990s, a new disease, caused by Utilago kamerunensis P. & H. Sydow was reported on the grass. Since there was a lack of information on the general pest and disease status of Napier grass in Kenya, a survey was carried out. The survey confirmed that U. kamerunensis was the major pest and disease threat to Napier grass production in the country, having spread to four districts and occurring in 27% of farm plots sampled. The existence of disease hotspots suggests that the main means of spread is through transport of infected planting material, and that the severity of the disease in Kenya compared with other countries results from an increase in the cultivation of Napier grass over the past decade.     

Mineralisation of Weathered Crude Oil by a Hydrocarbonoclastic Consortia in Marine Mesocosms

Marine waters are most vulnerable to crude oil pollution due to increased sea-based oil-related activities. Successful remediation of such polluted environments is normally carried out in a laboratory with suitable physical and environmental alterations. However, it is challenging to alter the physical and environmental conditions in crude oil-contaminated natural environments. In a previous study, six hydrocarbonoclastic bacteria were isolated from an oil-contaminated site. Here we report on their ability to mineralise weathered crude oil as a carbon source in seawater mesocosms, in order to construct a hydrocarbonoclastic consortia for the effective mineralisation of hydrocarbons present in the weathered crude oil at seawater-based environment. This was completed without altering the physical and environmental parameters (salinity, pH and temperature) and followed by the detection of microbial community changes. The total amount of oil mineralised by these six isolates individually over 28-day incubation ranged from 4.7 to 10?%. The bacterial consortia composed of these six strains showed a greater mineralisation rate (18.5?%). Temperature gradient gel electrophoresis revealed that the functionally dominant species were present after the first week (week 2 to week 4) following the addition of the consortia, which were represented in dendrogram by cluster 2 and also these weeks representing a distinct point on the Pareto?CLorenz curve; no community could be identified in controls in which no consortia were added. This shows that the addition of consortia potentially dealt with changing environmental conditions and preserved its functionality followed by effective mineralisation of weathered crude oil.     

Diagnostic indices of zinc deficiency in tropical legumes

The effect of 0.005 ppm, 0.01 ppm, 0.05 ppm and 0.10 ppm zinc on the growth and chemical composition of Desmodium uncinatum Jacq. cv. Silverleaf; Macroptilium lathyroides L.; Lablab purpureus; and Glycine max. L. cv. Wills were studied in solution culture in a controlled environment room.

Dry matter production of tops of all species was reduced at the lower zinc treatments while that of roots was unaffected by zinc supply.

Zinc concentrations of leaves from three plant positions did not provide a reliable index of zinc nutrition. The lowest zinc treatments often produced greater leaf concentrations of zinc than did higher zinc treatments. The cytoplasmic fractions of the leaf tissue contained the highest zinc concentrations. Cell walls, nuclei, chloroplasts and mitochondria contained extremely low concentrations, and the data were generally variable, reflecting the poor reproducibility of the techniques used.

Phosphorus concentrations in leaves were generally increased at the low zinc treatments, an effect not entirely attributable to the reduction in dry matter production. The proportion of inorganic phosphorus increased and that of organic phosphorus decreased at the lower zinc treatments. Lipoid and residual phosphorus fractions were not affected consistently by zinc treatments.

Leaves of plants receiving the lowest zinc treatment generally had significantly lower nitrogen concentrations than those receiving the higher zinc treatments.

In another experiment, in which Glycine wightii was substituted for G. max., RN‐ase activity increased as the zinc supply was reduced and this was accompanied by a decrease in protein concentration. The data show that RN‐ase activity could be a useful diagnostic index of incipient zinc deficiency.     

Fatal levamisole toxicosis of captive kiwi (Apteryx mantelli)

CASE HISTORY: Nine of 24 captive kiwi treated with oral levamisole at a dose between 25–43 mg/kg showed signs of respiratory distress. Six died within 4 h of treatment and the remaining three made a full recovery within 24 h.

CLINICAL AND PATHOLOGICAL FINDINGS: Within 3–4 h of treatment, the affected birds had an elevated respiratory rate, mucoid nasal discharge and rapidly became comatose. Post mortem examination revealed accumulation of thick mucus in the oral cavity and trachea. There was severe pulmonary congestion and oedema and early bronchopneumonia in the lungs of five of the birds. In two birds, there was acute hepatic degeneration and necrosis and one bird had acute pancreatic degeneration and necrosis.

DIAGNOSIS: Acute levamisole toxicity.

CLINICAL RELEVANCE: Kiwi were acutely sensitive to levamisole toxicity at doses that are well within the safe range for domestic poultry. Levamisole should not be used as an anthelmintic in kiwi.