Reducing the oxygen concentration of gases delivered from anaesthetic machines unadapted for medical air

High fractional concentrations of inspired oxygen (FiO(2)) delivered over prolonged periods produce characteristic histological changes in the lungs and airway of exposed animals. Modern medical anaesthetic machines are adapted to deliver medical air (FiO(2)=0.21) for the purpose of reducing FiO(2); anaesthetic machines designed for the veterinary market have not been so adapted. Two inexpensive modifications that allow medical air to be added to the gas flow from veterinary anaesthetic machines are described. The advantages and disadvantages of each modification are discussed.     

Long-term successful outcome of a Streptococcus equi subspecies equi brain abscess

We previously described successful treatment, including surgical drainage, of a Streptococcus equi subspecies equi brain abscess that caused severe neurological deficits in a 7-year-old Quarter Horse mare. This report details the long-term successful outcome of the case, findings of a magnetic resonance imaging (MRI) study performed 14 years after surgery and necropsy findings 18 years after initial treatment. Despite persistent cerebral and midbrain lesions detected by MRI and at necropsy, the mare returned to serviceable function within a year of initial treatment and had a successful performance career for over 10 years until carpal arthritis prompted retirement. This case demonstrates that brain abscess in horses can be successfully managed by combined medical and surgical treatment.     

Methods to assay absorption of foliar applied nutrients and removal of unabsorbed residue 1

Various glues and adhesives were tested for their ability to remove the unabsorbed residue from drops of foliar applied radioactive nutrients to Ficus benjamina L. and Glycine max Merr. Most glues/adhesives adequately removed the unabsorbed residue from nutrients that dried forming a salt deposit on the leaf surface, but only 1.6–3.2% agar, Rhoplex 33, and Elmers Glue removed greater than 95% of the residue from nutrients that formed a moist hygroscopic residue on the leaf surface. Adding 25 mM KH₂PO₄ to 3.2% agar, followed by swabbing the treated area with lN HCl‐1% Liquinox detergent removed all unabsorbed residue from monovalent and divalent cationic an anionic nutrients including heavy metals. Methods to assay foliar absorption were compared by applying “Rb phosphate to leaves of intact plants, excised leaves and leaf discs. Excised leaves with their petiole or stem bases in water behaved similar to intact plants, whereas excised leaves or discs maintained in in a moist atmosphere behaved atypically due to slower and incomplete drying compared to intact plants.     

Comparison of HCl extraction versos total iron analysis for iron tissue analysis

Extraction of Fe from fresh leaves with 0.1 N HCl proved to be a better indicator of the Fe status of a variety of ornamental tropical foliage and flowering plants compared to total Fe, 0.1 N HCl‐ether, and IN HCl extraction. It consistently gave higher correlations (r = 0.73 to 0.95 depending on the species) with chlorophyll concentration than the other methods tested. However, even 0.1 N HCl extraction did not distinguish levels of Fe deficiency accurately when compared between species.     

A comparison of methods for measuring phytotoxicity from foliar sprays of ammonium nitrate

In a series of experiments, plants of Salvia splendens ’St. John's Fire’ were sprayed to run‐off with NH₄NO₃ solutions that varied from 0.10–1.87 M (0.8–15.0% NH₄NO₃). Damage to young fully expanded leaves was determined by measuring percent visually estimated necrosis, leakage of UV (264 nm) absorbing constituents, K, Ca and phosphate, and post‐treatment dry weight:fresh weight ratio. The average correlation coefficient of percent visually estimated necrosis was 0.992 with leakage of UV absorbing constituents, 0.956 with leakage of phosphate, 0.951 with dry weightfresh weight ratio, 0.919 with leakage of Ca and 0.741 with leakage of K. Leakage of UV absorbing constituents consistently provided the best correlation with the visual degree of leaf burn.     

Iron chlorosis development and growth response of peach rootstocks to bicarbonate 1

For dicots, bicarbonate (HCO₃‐) is regarded as a main factor in the induction of iron (Fe) chlorosis in calcareous soils, and sand and solution culture. In sand culture experiments, peach [Prunus persica (Batsch) L.] rootstock developed chlorosis only when HCO₃‐ levels were equal to or higher than 6 mM. Above this level, chlorosis increaeed as HCO3‐ level was increased. In spite of the lack of chlorosis at to or below 6 mM of HCO₃‐, large growth reductions (40–60% reduction in fresh shoot weight) were seen in all rootstocks, although the tolerant rootstock had less reduction than the more susceptible rootstocks. Shoot growth was affected by HCO₃‐ more than was root growth.     

Land degradation assessment in Southern Africa: integrating local and scientific knowledge bases

Recent attempts to address land degradation have seen calls for greater integration of scientific expertise with local knowledges. In this paper we investigate the potential for such combined understandings to enhance the accuracy, coverage and relevance of land degradation assessment. We followed a participatory approach, using methods from a variety of disciplines, to elicit potential land degradation indicators from communities in Botswana and Swaziland. These indicators were then assessed according to local and scientific understandings. We noted a significant overlap between scientific and local knowledges about land degradation in most instances. Where discrepancies occurred, the integrated participatory approach we used allows appropriate explanation to be reached, supporting the case that such an iterative process can lead to both accurate and relevant monitoring of land degradation. However, the incorporation of integrated knowledges into national policy has not been widespread in either country, suggesting that much greater efforts are required to institutionalise participatory land degradation assessment methodologies. Powerful, often neo‐Malthusian narratives of degradation continue to dominate policy discourse and limit the extent to which hybrid combined local and scientific knowledges can enhance land degradation assessment on a national and regional scale. Copyright © 2006 John Wiley & Sons, Ltd.     

Foliar nematode,Litylenchus crenatae ssp. mccannii,population dynamics in leaves and buds of beech leaf disease‐affected trees in Canada and the US

A foliar nematode, Litylenchus crenatae ssp. mccannii, is associated with beech leaf disease (BLD) symptoms. Information about the types of tissues parasitized and how nematode populations fluctuate in these tissues over time is needed to improve surveys as well as understand the nematodes role in BLD. During this study, the nematode was detected throughout the known range of BLD by researchers at both Canadian and US institutions using a modified pan method to extract nematodes. Monthly collections of symptomatic and asymptomatic leaves during the growing season (May–October), and leaves and buds between growing seasons (November–March), revealed that nematodes were present in all tissue types. Progressively larger numbers of nematodes were detected in symptomatic leaves from Ohio and Ontario, with the greatest detections at the end of the growing season. Smaller numbers of nematodes were detected in asymptomatic leaves from BLD‐infected trees, typically at the end of the growing season. The nematode was detected overwintering in buds and detached leaves. The discovery of small numbers of nematodes in detached leaves at one location before BLD was detected indicates that nematodes may have been present before disease symptoms were expressed. Other nematodes, Plectus and Aphelenchoides spp., were infrequently detected in small numbers. Our findings support the involvement of the nematode in BLD and indicate that symptoms develop only when certain requirements, such as infection of buds, are met. We also found that the nematode can be reliably detected in buds and leaves using the modified pan extraction method.     

Renal myxozoanosis in weedy sea dragons, Phyllopteryx taeniolatus (Lacepède), caused by Sinuolinea phyllopteryxa n. sp.

Renal myxozoanosis was diagnosed histologically in 11 captive, wild caught, adult weedy (common) sea dragons, Phyllopteryx taeniolatus, from three separate public aquaria in the United States. Myxozoan spores were visible in wet mounts of kidney tissue and were associated with renal tubular dilatation and tubular epithelial cell hypertrophy. Light and electron microscopy revealed spore morphology consistent with the genus Sinuolinea. Spores were spheroidal, slightly dorso-ventrally compressed, length (L) 17.1 x width (W) 16.4 x thickness (T) 15.6 microm, with two shell valves joined at a distinct, sinuous sutural ridge, and had two nearly spherical polar capsules, L 5.5 x W 5.0 microm, with five to seven turns of the polar filament. There were no extra-valvular ridges or protrusions. DNA sequencing required the design of three new primers that yielded 1740 bp of 18S ribosomal DNA sequence. The parasite was determined to be novel based on morphological and molecular data, and was given the name Sinuolinea phyllopteryxa after its vertebrate host.