Tonotopic organization of the auditory cortex: pitch versus frequency representation

According to the place principles of the classical hearing theory, the physical entity frequency is encoded in the auditory periphery as place information (tonotopic representation), which is decoded in more central parts of the auditory system to form the subjective entity pitch. However, this relation is true only for pure-tone signals (spectral pitch); it can be quite different in the case of complex auditory stimuli (virtual pitch), thus requiring a multistage process for pitch formation. Neuromagnetic measurements showed that the tonotopic organization of the primary auditory cortex reflects the pitch rather than the frequency of the stimulus; that is, the pitch formation process must take place in subcortical regions.     

Marking to weaning production aspects of lambs provided with NSAID analgesia compared with lambs receiving no analgesia at the time of elastrator ring marking

The provision of analgesia at the time of marking has been adopted by the Australian sheep industry, but data on production benefits are lacking. In the current study, alternate lambs were provided with either meloxicam (non‐steroidal anti‐inflammatory drug [NSAID], n = 781) or no analgesia (NONE, n = 822) at the time of ring castration and tail docking. Six distinct management groups of lambs were studied. Lambs were weighed immediately before marking and then again at weaning. There was no significant effect of treatment on average daily gain between marking and weaning in cross‐bred lambs. In Merino lambs, average daily gain was 5 g/day lower (P < 0.005) in lambs receiving NSAID, but this may not be biologically significant. Lamb losses were significantly (P < 0.05) lower in the NSAID group (1.1%) than in the NONE group (2.7%). This observation is worth validating in larger studies, particularly considering that lamb mortality is a significant cost to production and welfare concern.     

Antagonism of detomidine with tolazoline in isoflurane-anaesthetised ponies

The effects of tolazoline (4.0 mg/kg iv) antagonism of detomidine (0.02 mg/kg iv) were evaluated in isoflurane-anaesthetised, ventilated ponies. Each of 6 ponies received both tolazoline and saline treatment during separate anaesthetic episodes only (no surgery was performed). Detomidine administration produced an increase in blood pressure, decrease in heart rate and decrease in P_aO₂ Tolazoline treatment transiently increased heart rate while blood pressure returned to baseline after both treatments. Arterial oxygenation decreased further after tolazoline treatment while oxgenation recovered towards baseline with saline treatment. No other cardiopulmonary effects were detected. Recovery from anaesthesia tended to be more rapid when detomidine was antagonized. The potential benefit of antagonizing detomidine-induced bradycardia with tolazoline, during isoflurane anaesthesia should be weighed against the potential to produce a decrease in arterial oxygenation. The mechanism for this effect is not clear.     

Quantification of Cylindrocarpon destructans f. sp. panacis in soils by real-time PCR

Ginseng ( Panax quinquefolius ) is an important cash crop in various regions of North America, but yields are often reduced by various root pathogens. A quantitative real-time PCR (qPCR) assay for Cylindrocarpon destructans f. sp. panacis (CDP), the cause of a root rot and replant disease which discourages successive cropping of ginseng on the same site, was developed to quantify the levels of this pathogen in soils previously cropped with ginseng. DNA was extracted from 5-g samples of soil. In pasteurized soils which were re-infested with varying levels of the pathogen, qPCR estimates of pathogen DNA were significantly correlated with disease severity ( r  = 0·494) and with counts of colony-forming units ( r  = 0·620) obtained with an agar medium. In several naturally infested field soils, qPCR estimates of CDP-DNA concentration were significantly correlated with disease severity ( r  = 0·765) and these concentrations were estimated to range from 0 to 1·48 ng g⁻¹ dried soil. A principal components analysis did not show any strong relationships between soil chemistry factors and the concentration of pathogen DNA. The approach outlined here allows the quantification of current populations of CDP in soil many years after ginseng cultivation and the prediction of disease severity in future crops. The method should be generally applicable to root diseases of many crops.     

Visceral mast cell tumour with eosinophilia and eosinophilic peritoneal and pleural effusions in a cat

Summary A cat with weight loss, pyrexia and recurrent lethargy and depression was found to have pleural and peritoneal eosinophilic effusions, peripheral eosinophilia, eosinophilic lymphadenitis and a massively enlarged mesenteric lymph node. Visceral mast cell neoplasia was diagnosed after histopathological examination of a biopsy of the mass. Palliative chemotherapy was attempted unsuccessfully and the cat was euthanased.     

A tunable kondo effect in quantum dots

A tunable Kondo effect has been realized in small quantum dots. A dot can be switched from a Kondo system to a non-Kondo system as the number of electrons on the dot is changed from odd to even. The Kondo temperature can be tuned by means of a gate voltage as a single-particle energy state nears the Fermi energy. Measurements of the temperature and magnetic field dependence of a Coulomb-blockaded dot show good agreement with predictions of both equilibrium and nonequilibrium Kondo effects.     

Third‐compartment cannulation in alpacas using a polyurethane gastrostomy tube

Objective To develop a simple and effective surgical technique for third‐compartment cannulation in alpacas. Design Prospective study using six adult male alpacas. Methods General anaesthesia was induced and a polyurethane gastrostomy tube was surgically implanted into the distal portion of the third compartment. Results Three of the alpacas retained their cannulas for a 100‐day period; however, three cannulas were dislodged during the study. Two of the three dislodged cannulas were replaced during a second surgical procedure. Cannulas were well tolerated by the alpacas and all animals remained clinically healthy during the study period. Third compartment contents did not leak from the cannulation site. The tubes were manually removed following the completion of the study and the small defect in the body wall quickly healed over in all animals. Conclusion Surgical placement of polyurethane tubes designed for percutaneous endoscopic gastrostomy is a useful method of cannulating the third compartment in camelids. This technique can be used for experimental studies and possibly could be used for nutritional support and fluid therapy in sick camelids that might need long‐term care.     

Biomimetic Pathways for Assembling Inorganic Thin Films

Living organisms construct various forms of laminated nanocomposites through directed nucleation and growth of inorganics at self-assembled organic templates at temperatures below 100°C and in aqueous solutions. Recent research has focused on the use of functionalized organic surfaces to form continuous thin films of single-phase ceramics. Continuous thin films of mesostructured silicates have also been formed on hydrophobic and hydrophilic surfaces through a two-step mechanism. First, under acidic conditions, surfactant micellar structures are self-assembled at the solid/liquid interface, and second, inorganic precursors condense to form an inorganic-organic nanocomposite. Epitaxial coordination of adsorbed surfactant tubules is observed on mica and graphite substrates, whereas a random arrangement is observed on amorphous silica. The ability to process ceramic-organic nanocomposite films by these methods provides new technological opportunities.