Fungi isolated from bovine udders,and their possible sources

AIM: To identify fungi isolated from infections of the bovine mammary gland, and establish their possible sources.

METHODS: From a herd of 420 cows, milk samples were collected from all quarters at calving and cultured to detect causative organisms. Quarters identified as infected with fungi were further sampled during early lactation. Samples from feedstuffs, the feed pad and ends of teats were also collected and analysed for the presence of fungi.

RESULTS: Eleven of 420 cows were diagnosed with intramammary infections (IMI) caused by yeasts (nine cows, 10 quarters) and moulds (two cows, three quarters). Six of the yeast species had previously been reported as being responsible for mastitis. Elevated somatic cell counts (SCC) were observed in many quarters, but most infections were eliminated spontaneously. Two of the fungi isolated from milk samples were also isolated from feedstuffs and teat swabs, and seven other fungi isolated from milk samples were not isolated from feed, the feed pad or cows' teats.

CONCLUSIONS: Isolation of fungi from the udder is rarely reported in dairy cows in New Zealand. In this herd, contamination of the end of the teat originating from feedstuffs and possibly exacerbated by the use of a feed pad may have led to the establishment of IMI caused by fungi.

CLINICAL RELEVENCE: Fungi are infrequently if ever reported in mastitis trial data or surveys in New Zealand and are probably of little clinical significance.     

Molecular subtyping of feline immunodeficiency virus from cats in Melbourne

OBJECTIVE: To determine the subtypes of feline immunodeficiency virus (FIV) present in the domestic cat population in Melbourne. METHODS: Blood samples were collected from 42 cats that had serum antibodies against FIV. DNA was extracted and subjected to polymerase chain reaction (PCR) to amplify variable regions of the envelope (env) and group specific antigen (gag) genes of FIV. PCR products were directly sequenced or sequenced after cloning when direct sequencing yielded ambiguous results. Phylogenetic analysis was performed and comparisons made with representative sequences of different subtypes. RESULTS: The variable region of the env gene was successfully amplified by PCR from 41 of the 42 cats. All 41 were found to cluster with subtype A env sequences. The variable region of the gag gene was successfully amplified by PCR from all 42 cats. Forty-one were found to cluster with subtype A gag genes and one was found to cluster with subtype B sequences, suggesting that it may be derived from a recombinant env A/gag B virus. CONCLUSIONS: Subtype A is the predominant FIV type in Melbourne, although a subtype A/B recombinant was identified in the population of FIV positive cats. These results of env gene analysis were similar to those in a previous Australian study, suggesting that subtype A predominates in Australia. The results of the gag gene analysis show the importance of analysing multiple areas of the FIV genome when assigning FIV subtypes. Comparison with other major urban centres may provide useful information about the phylogenic diversity of FIV in Australia.     

Synthesis of large arrays of well-aligned carbon nanotubes on glass

Free-standing aligned carbon nanotubes have previously been grown above 700 degreesC on mesoporous silica embedded with iron nanoparticles. Here, carbon nanotubes aligned over areas up to several square centimeters were grown on nickel-coated glass below 666 degreesC by plasma-enhanced hot filament chemical vapor deposition. Acetylene gas was used as the carbon source and ammonia gas was used as a catalyst and dilution gas. Nanotubes with controllable diameters from 20 to 400 nanometers and lengths from 0. 1 to 50 micrometers were obtained. Using this method, large panels of aligned carbon nanotubes can be made under conditions that are suitable for device fabrication.     

Localization of metastable atom beams with optical standing waves: nanolithography at the heisenberg limit

The spatially dependent de-excitation of a beam of metastable argon atoms, traveling through an optical standing wave, produced a periodic array of localized metastable atoms with position and momentum spreads approaching the limit stated by the Heisenberg uncertainty principle. Silicon and silicon dioxide substrates placed in the path of the atom beam were patterned by the metastable atoms. The de-excitation of metastable atoms upon collision with the surface promoted the deposition of a carbonaceous film from a vapor-phase hydrocarbon precursor. The resulting patterns were imaged both directly and after chemical etching. Thus, quantum-mechanical steady-state atom distributions can be used for sub-0.1-micrometer lithography.     

An approximately 15,000-year record of El Nino-driven alluviation in southwestern ecuador

Debris flows have deposited inorganic laminae in an alpine lake that is 75 kilometers east of the Pacific Ocean, in Ecuador. These storm-induced events were dated by radiocarbon, and the age of laminae that are less than 200 years old matches the historic record of El Nino events. From about 15,000 to about 7000 calendar years before the present, the periodicity of clastic deposition is greater than or equal to 15 years; thereafter, there is a progressive increase in frequency to periodicities of 2 to 8.5 years. This is the modern El Nino periodicity, which was established about 5000 calendar years before the present. This may reflect the onset of a steeper zonal sea surface temperature gradient, which was driven by enhanced trade winds.     

Drift reduction and droplet-size in sprays containing adjuvant oil emulsions

The droplet-sizes and drift produced by sprays containing dilute oil-in-water emulsions of various vegetable and mineral oil adjuvants were measured in wind-tunnel experiments. When compared with water or a surfactant solution, both types of oil adjuvant reduced the proportion of small driftable droplets and, hence, reduced measured spray drift. Vegetable oils were more effective at drift reduction than the mineral oil. Spray drift tended to increase with increasing oil concentration and decreasing emulsifier content.     

Widespread divergence between incipient Anopheles gambiae species revealed by whole genome sequences

The Afrotropical mosquito Anopheles gambiae sensu stricto, a major vector of malaria, is currently undergoing speciation into the M and S molecular forms. These forms have diverged in larval ecology and reproductive behavior through unknown genetic mechanisms, despite considerable levels of hybridization. Previous genome-wide scans using gene-based microarrays uncovered divergence between M and S that was largely confined to gene-poor pericentromeric regions, prompting a speciation-with-ongoing-gene-flow model that implicated only about 3% of the genome near centromeres in the speciation process. Here, based on the complete M and S genome sequences, we report widespread and heterogeneous genomic divergence inconsistent with appreciable levels of interform gene flow, suggesting a more advanced speciation process and greater challenges to identify genes critical to initiating that process.     

Assessment of Vascular Perfusion Kinetics Using Contrast‐enhanced Ultrasound for the Diagnosis of Prostatic Disease in Dogs

Vascular perfusion was assessed in 10 dogs without prostatic abnormalities and 26 dogs with prostatic disease using contrast‐enhanced ultrasound. The time to reach peak contrast intensity (TTP) and peak perfusion intensity (PPI) were measured, and histological biopsies were collected from each dog. Biopsies confirmed normal prostate (n = 10), benign prostatic hyperplasia (n = 11), mixed benign pathology (n = 9), prostatitis (n = 1), prostatic malignancy [adenocarcinoma (n = 4); leiomyosarcoma (n = 1)]. In normal dogs, mean PPI was 16.8% ± 5.8 SD, and mean TTP was 33.6 ± 6.4 s. Benign conditions overall were not statistically different from normal dogs (p > 0.05); for benign prostatic hyperplasia, mean PPI was 16.9 ± 3.8%, and mean TTP was 26.2 ± 5.8 s; for mixed benign pathology mean PPI was 14.8 ± 7.8%, and mean TTP was 31.9 ± 9.7 s; for prostatitis, PPI was 14.2%, and TTP was 25.9 s. The malignant conditions overall had perfusion values that differed from the normal dogs (p < 0.05), although evaluation of the data for individual malignancies did not demonstrate a consistent trend; for adenocarcinomas, the PPI was numerically higher with a mean of 23.7 ± 1.9%, and the mean TTP was 26.9 ± 4.8 s, whilst for the dog with leiomyosarcoma values were numerically lower with a PPI of 14.1% and TTP of 41.3 s. Contrast‐enhanced ultrasound appears to offer some ability to document differences in perfusion that may differentiate between malignant and benign lesions, although studies with larger numbers of animals are required to confirm this contention.     

Contrast-enhanced ultrasonography in the differentiation of retinal detachment and vitreous membrane in dogs and cats

Objectives : To evaluate contrast‐enhanced ultrasonography (CEU) and colour Doppler imaging (CDI) for detection of persistent vascularisation in retinal detachment. Methods : In 22 eyes, retinal detachment (n=13) and vitreous membranes (n=9) were confirmed by ophthalmological examination, during cataract surgery, by histopathology or after vitreoretinal surgery. Tentative diagnosis of retinal detachment or vitreous membrane was made using grey‐scale B‐mode ultrasonography. Assessment of retinal detachment was based on the presence or absence of vascularisation in the membranous structure using CDI and CEU. Results : Sensitivity, specificity, positive‐predictive value and negative‐predictive value of grey‐scale ultrasonography in differentiating retinal detachment from vitreous membrane were 92·3%, 66·6%, 80% and 85·7%. In 91% of eyes, colour Doppler assessment was unsuccessful due to the movement of the eye. Persistent vascularisation was demonstrated in all cases of retinal detachments with CEU. CEU was 100% accurate for detection and differentiation between retinal detachment and vitreous membrane. Clinical Significance : CEU is a useful clinical tool for the diagnosis of retinal detachment and vitreous membrane in dogs and cats.