Influence of less than full-time or full-time on totality of training and subsequent consultant appointment in anaesthesia.

Changes in medical training have increased the popularity of less than full-time training. However, there are no data on the impact on training time or consultant workforce. We reviewed a three-year cohort of trainees via the Royal College of Anaesthetist's training and recruitment databases. Eighty-eight (96%) less than full-time trainees and 677 (95%) full-time trainees were appointed to a substantive consultant post (p = 0.82). Three (3%) less than full-time trainees and 12 (2%) full-time trainees gained part-time consultant posts (p < 0.001). Average length of training (years, months, days) was 8 y, 5 m, 6 d (median (IQR [range]) 5 y, 0 m, 14 d (4 y, 11 m, 29 d - 9 y, 8 m, 3 d [4 y, 2 m, 18 d - 12 y, 0 m, 0 d]) for full-time and 10 y, 8 m, 23 d (median (IQR [range]) 7 y, 3 m, 28 d (6 y, 7 m, 24 d - 11 y, 1 m, 23 d [4 y, 11 m, 29 d - 11 y, 9 m, 10 d]) for less than full-time trainees. The average length of training for both groups is significantly longer than the seven years used in workforce planning.

Cytotoxicity of clove (Syzygium aromaticum) oil and its major components to human skin cells.

The essential oil extracted from clove (Syzygium aromaticum) is used as a topical application to relieve pain and promote healing in herbal medicine and also finds use in the fragrance and flavouring industries. Clove oil has two major components, eugenol and beta-caryophyllene, which constitute 78% and 13% of the oil, respectively. Clove oil and these components are generally recognized as 'safe', but the in-vitro study here demonstrates cytotoxic properties of both the oil and eugenol, towards human fibroblasts and endothelial cells. Clove oil was found to be highly cytotoxic at concentrations as low as 0.03% (v/v) with up to 73% of this effect attributable to eugenol. beta-caryophyllene did not exhibit any cytotoxic activity, indicating that other cytotoxic components may also exist within the parent oil.

Accessory chemosignaling mechanisms in primates.

Accessory olfaction is defined as the chemoreceptive system that employs the vomeronasal complex (VNC) and its distinct central projections to the accessory olfactory bulb (AOB) and limbic/cortical systems. Comparisons of the structural and functional features of primate accessory olfaction can now be made at many levels. Advances in the understanding of molecular mechanisms of odorant transfer and detection, physiological analyses of signal processing, and appreciation of ontogenetic timetables have clarified the contribution of accessory chemoreception to the sensory map. Two principal functions dominate: the decoding of social information through the uptake of signals (often fluid-borne), and the provision of an essential pathway for the "migration" of presumptive neurocrine (GnRH) cells from the olfactory placode to the hypothalamus. VN "smelling" (vomerolfaction) is now seen to overlap with primary olfaction. Both systems detect signal compounds along the spectrum of volatility/molecular weight, and neither is an exclusive sensor. Both main and accessory chemoreception seem to require collaborative molecular devices to assist in odorant transfer (binding proteins) and (for the VNO) signal recognition (MHC1 proteins). Most adaptive-selective features of primate chemocommunication variously resemble those of other terrestrial mammals. VN function, along with its genome, has been maintained within the Strepsirrhines and tarsiers, reduced in Platyrrhines, and nearly extinguished at the Catarrhine up to hominin levels. It persists as an intriguing ancient sense that retains key features of past evolutionary events.

Cytotoxicity of lavender oil and its major components to human skin cells.

Lavender (Lavandula angustifolia) oil, chiefly composed of linalyl acetate (51%) and linalool (35%), is considered to be one of the mildest of known plant essential oils and has a history in wound healing. Concerns are building about the potential for irritant or allergenic skin reactions with the use of lavender oil. This study has demonstrated that lavender oil is cytotoxic to human skin cells in vitro (endothelial cells and fibroblasts) at a concentration of 0.25% (v/v) in all cell types tested (HMEC-1, HNDF and 153BR). The major components of the oil, linalyl acetate and linalool, were also assayed under similar conditions for their cytotoxicity. The activity of linalool reflected that of the whole oil, indicating that linalool may be the active component of lavender oil. Linalyl acetate cytotoxicity was higher than that of the oil itself, suggesting suppression of its activity by an unknown factor in the oil. Membrane damage is proposed as the possible mechanism of action.

Design of the Jacky dragon visual display: signal and noise characteristics in a complex moving environment.

Visual systems are typically selective in their response to movement. This attribute facilitates the identification of functionally important motion events. Here we show that the complex push-up display produced by male Jacky dragons ( Amphibolurus muricatus) is likely to have been shaped by an interaction between typical signalling conditions and the sensory properties of receivers. We use novel techniques to define the structure of the signal and of a range of typical moving backgrounds in terms of direction, speed, acceleration and sweep area. Results allow us to estimate the relative conspicuousness of each motor pattern in the stereotyped sequence of which displays are composed. The introductory tail-flick sweeps a large region of the visual field, is sustained for much longer than other components, and has velocity characteristics that ensure it will not be filtered in the same way as wind-blown vegetation. These findings are consistent with the idea that the tail-flick has an alerting function. Quantitative analyses of movement-based signals can hence provide insights into sensory processes, which should facilitate identification of the selective forces responsible for structure. Results will complement the detailed models now available to account for the design of static visual signals.

A rapid and efficient mass spectrometric method for the analysis of explosives.

The high explosives trinitrotoluene, nitroglycerine, pentaerythritol tetranitrate and hexahydro-1,3,5-trinitro-1,3,5-triazine are efficiently ionised under negative ion atmospheric pressure chemical ionisation (APCI) conditions. The limit of detection is improved, in some cases by several orders of magnitude, by complexation with chlorine demonstrating this to be a highly suitable method for enhancing the detection capabilities for explosives. The spectra produced from introduction of the analytes in a liquid matrix, with and without chlorine present, contain a number of ions that arise through secondary processes including breakdown and adduct formation. Sample introduction into an APCI source in air, via a heated-plate inlet with a supplementary feed of dichloromethane, produces improved response for the chloride adducts of the analytes and minimises their decomposition during analysis. The tandem mass spectra produced from the chloride adducts are simple. Optimisation of the trapping parameters of the ion trap detector enhances selected transitions, yields highly reproducible spectra and improves the limits of detection for MS/MS analysis.

Adaptation of the white-rot basidiomycete Panus tigrinus for transformation of high concentrations of chlorophenols.

During feed-batch cultivation of the white-rot fungus Panus tigrinus in a 5-l bioreactor on N-limited medium, 100, 200, 500, 1,000 and 2,000 mg 2,4,6-trichlorophenol (2,4,6-TCP) l(-1) were added sequentially after 90% removal of the previous portion of the toxicant. The addition of 500 mg 2,4,6-TCP l(-1) without preliminary adaptation killed the culture. The addition of 300 mg 2,4,6-TCP l(-1) without prior adaptation resulted in its slower removal than removal of 2,000 mg 2,4,6-TCP l(-1) by this adapted culture. After adaptation of P. tigrinus to 2,4,6-TCP in a 72-l bioreactor, the mixture of 2,4-dichlorophenol, 2,4,6-TCP, and pentachlorophenol, each at 500 mg x l(-1), was totally removed over 3 weeks. No lignin peroxidase activity was found in the course of cultivation of the fungus. Laccase activity was suppressed by addition of 2,4,6-TCP. Mn-peroxidase was found to be responsible for transformation of the chlorophenols. As final products of the process, several newly formed aromatic polymers, both chlorinated and non-chlorinated, were found in the culture liquid.

Transformation of 2,4,6-trichlorophenol by free and immobilized fungal laccase.

Laccase from the white rot fungus Coriolus versicolor was immobilized on Celite R-637 by covalent binding with glutaraldehyde. After a sharp primary decline in activity (up to 50%), the retained enzyme activity was stable over a storage period of 33 days at 4 degrees C. A comparative study of soluble and immobilized laccases revealed the increased resistance of immobilized enzyme to the unfavourable effects of alkaline pH, high temperature and the action of inhibitors. A combination of these properties of immobilized laccase resulted in the ability to oxidize 2,4,6-trichlorophenol (2,4,6-TCP) at 50 degrees C at pH 7.0. The reactions of soluble and immobilized laccase with 2,4,6-TCP were examined in the presence and absence of redox mediators. 3,5-Dichlorocatechol, 2,6-dichloro-1,4-benzoquinone and 2,6-dichloro-1,4-hydroquinone were found to be the primary products of 2,4,6-TCP oxidation by laccase; oligo- and polymeric compounds were also found.

Formation of gas-phase clusters monitored during electrospray mass spectrometry: a study of quaternary ammonium pesticides.

Gas-phase cluster formation between the quaternary ammonium pesticides paraquat, diquat, difenzoquat, chlormequat and mepiquat, and chloride and acetate anions present in a liquid chromatography (LC) mobile phase, has been studied using electrospray mass spectrometry. The clusters of paraquat, mepiquat and chlormequat were revealed over the entire m/z range of the mass spectrometer, and their formation is dependent on the concentrations of both the cationic and the anionic species. Mepiquat and chlormequat form clusters of the type [2M(q)(+) + A(-)](+), where M(q)(+) is the quaternary ammonium cation and A(-) is the anion. Paraquat forms a cluster species with ammonia and also an ion-pair complex with chloride anions. Diquat and difenzoquat did not form observable ion-pair complexes or clusters with any of the anions studied. Competitive binding of acetate and chloride anions reflects the higher charge density of chloride, which forms the dominant clusters with mepiquat and chlormequat. The formation of cluster species has implications for the quantification of quaternary ammonium pesticides and may have an influence on the linearity of calibrations.

Tandem mass spectrometric analysis of quaternary ammonium pesticides.

A detailed MS(n) study on an ion trap instrument of the quaternary ammonium pesticides paraquat, diquat, difenzoquat, mepiquat and chlormequat reveals a number of ions not reported previously, and has allowed examination of the fragmentation pathways. A number of transitions that are highly specific to each quat have been identified. Optimal ion trap operating conditions determined using Simplex optimisation can promote either detection of a particular fragmentation transition or a range of MS/MS product ions with a high overall signal response. Thus, fragmentation conditions were optimised to enhance the specificity or sensitivity of MS/MS methods.

Intrasexual selection predicts the evolution of signal complexity in lizards.

Sexual selection has often been invoked in explaining extravagant morphological and behavioural adaptations that function to increase mating success. Much is known about the effects of intersexual selection, which operates through female mate choice, in shaping animal signals. The role of intrasexual selection has been less clear. We report on the first evidence for the coevolution of signal complexity and sexual size dimorphism (SSD), which is characteristically produced by high levels of male male competition. We used two complementary comparative methods in order to reveal that the use of complex signals is associated with SSD in extant species and that historical increases in complexity have occurred in regions of a phylogenetic tree characterized by high levels of pre-existing size dimorphism. We suggest that signal complexity has evolved in order to improve opponent assessment under conditions of high male male competition. Our findings suggest that intrasexual selection may play an important and previously underestimated role in the evolution of communicative systems.

Improved sensitivity in detection of chlormequat by liquid chromatography-mass spectrometry.

Two published separations, using electrospray mass spectrometry (ES-MS), exhibit significant differences in limits of detection (LODs) for chlormequat cation in pear. Separation on ODS1, confirmed to result from ion-exchange, gives shorter analysis times and calibration over a wider concentration range than on an SCX cation-exchange column. The superior LOD using ODS1 (0.04 ng ml(-1) vs. 1.0 ng ml(-1)) results mainly from better chromatographic peak shape. Separation on ODS1 combined with optimised ES-MS detection allows direct quantification of chlormequat on an ion trap instrument at levels lower than those required for residue analysis in foods and also in drinking water.

The web browser as a unifying agent for radiology and the health care enterprise.

A variety of information systems in the health care enterprise are used to store patient information. The hospital information system (HIS), the picture archiving and communications system (PACS), the radiology information systems (RIS), and patient records, for example, are often supported by separate and distinct systems. A referring physician reviewing a radiologist's report often does not have convenient access to the original radiologic images. A radiologist interpreting a radiologic examination may not have convenient access to clinical information generated outside of the radiology department. Clearly, convenient and quick access to all relevant patient information is the ideal in delivering quality patient care. Recently, the web browser has become increasingly well accepted as the "universal client" for viewing a wide variety of information. We believe that the web browser may provide the universal "window" to the variety of distinct information sources required by the physician, and may provide unification of these information sources through hypertext links. We specifically looked at the feasibility of using the web browser to view scanned patient charts. A total of 5,200 patient charts (131,000 pages) were scanned into a structured query language (SQL) database. Access to these records was made available on the hospital local area network (LAN), and on the Internet over the worldwide web. Comparison measurements were made of the time required to access patient records using a dedicated viewing application and using a web browser.

Detection of bilateral symmetry in complex biological images.

The recognition of bilateral symmetry in simple dot patterns is reliably influenced by orientation. Performance is best when the axis of symmetry is vertical. We conducted two experiments to determine whether stimulus orientation also affects detection of the low levels of naturally occurring asymmetry in complex biological images. University students judged whether colour images displayed on a computer monitor possessed perfect bilateral symmetry. Stimuli were generated from high-resolution plan-view images of crabs and insects. In experiment 1, the asymmetric stimuli were the original animals, displayed on a standard black background. Symmetrical versions of each natural image were generated by sectioning the shape at the midline, copying and reflecting one side and then fusing the two halves together. To facilitate comparison of results with those obtained in earlier studies, we also presented dot patterns based upon both the slightly asymmetric and perfectly symmetrical natural images. Experiment 2 was designed to assess whether symmetry detection was dependent upon the markings and patterns on the body and appendages of the animals. The natural images were converted to silhouettes and tested against matched dot patterns. In both studies, images were presented in a random sequence with the axis of symmetry vertical, horizontal, oblique left, and oblique right. Performance with the biological images was consistently better than with the dot patterns. Abolishing fine detail did not appreciably reduce this effect. A pronounced vertical advantage was apparent with all stimuli, demonstrating that this phenomenon is robust despite considerable variation in image complexity. The implications of orientation effects for perception of natural structures are discussed.

Reactions of pentachlorophenol with laccase from Coriolus versicolor.

Laccase, purified from Coriolus versicolor, removed pentachlorophenol (PCP) from solution at pH 5, depending on initial PCP concentration and amount of laccase. With 100 units of laccase, 100% of 25 microg ml(-1) PCP and 60% of 200 microg ml(-1) PCP were removed respectively over 72 h. No free chloride was released in the reaction. In reaction with 100 microg PCP, products were primarily polymers (about 80,000 MW) with only 2-3 pg of o- and p-chloranils formed. Polymers were stable to acid hydrolysis and no release of PCP, or other low-molecular-weight products, was detected over several weeks. Laccase has a potential use in the biotreatment of aqueous effluents containing PCP, with polymerised products being removed from solution due to their high molecular weight.

Optimisation of ion trap parameters for the quantification of chlormequat by liquid chromatography/mass spectrometry and the application in the analysis of pear extracts.

Optimisation of the activation parameters for ion trap mass spectrometric analysis of the chlormequat cation using simplex optimisation enabled the product ion (m/z 58) response to be improved 1000-fold. A comparison of the sensitivity of the optimised ion trap mass spectrometer with that of a triple quadrupole mass spectrometer for liquid chromatography/tandem mass spectrometry (LC/MS/MS) showed that similar limits of detection (LODs) could be achieved. For the MS/MS transition of the (35)Cl precursor to the most abundant product, LODs were 0.8 ng cation mL(-1) (0.004 mg cation kg(-1) pear equivalent) and 1.0 ng cation mL(-1) (0.005 mg cation kg(-1) pear equivalent) on the triple quadrupole and ion trap instrument, respectively.

Evaluation of solid substrates for enzyme production by Coriolus versicolor, for use in bioremediation of chlorophenols in aqueous effluents.

In the development of a system for the removal of chlorophenols from aqueous effluents, a range of solid substrates for the growth of Coriolus versicolor were investigated. Substrates included wood chips, cereal grain, wheat husk and wheat bran. Suitability for transformation of chlorophenols depended on laccase production by the fungus. The greatest amount of laccase (<25 Units g(-1) substrate) was produced on wheat husk and wheat bran over 30 days colonisation. Aqueous extracts of laccase from wheat husk and wheat bran cultures removed 100% of 2,4-dichlorophenol (50 ppm) from solution within 5 h and 75-80% of pentachlorophenol (50 ppm) within 24 h. Wheat bran was formulated into pellets with biscuit flour to provide a compact substrate for fungal immobilisation. Addition of 8-12% yeast extract to the pellets increased laccase production five-fold. Colonised pellets were added to chlorophenol solutions in 200-4000-ml bioreactors, resulting in >90% removal of chlorophenols within 100 min.

Transformation of 2,4,6-trichlorophenol by the white rot fungi Panus tigrinus and Coriolus versicolor.

The toxicity of thirteen isomers of mono-, di-, tri- and pentachlorophenols was tested in potato-dextrose agar cultures of the white rot fungi Panus tigrinus and Coriolus versicolor. 2,4,6-Trichlorophenol (2,4,6-TCP) was chosen for further study of its toxicity and transformation in liquid cultures of these fungi. Two schemes of 2,4,6-TCP addition were tested to minimize its toxic effect to fungal cultures: stepwise addition from the moment of inoculation and single addition after five days of growth. In both cases the ligninolytic enzyme systems of both fungi were found to be responsible for 2,4,6-TCP transformation. 2,6-Dichloro-1,4-hydroquinol and 2,6-dichloro-1,4-benzoquinone were found as products of primary oxidation of 2,4,6-TCP by intact fungal cultures and purified ligninolytic enzymes, Mn-peroxidases and laccases of both fungi. However, primary attack of 2,4,6-TCP in P. tigrinus culture was conducted mainly by Mn-peroxidase, while in C. versicolor it was catalyzed predominantly by laccase, suggesting a different mode of regulation of these enzymes in the two fungi.

Female preference for swords in Xiphophorus helleri reflects a bias for large apparent size.

Swordtail fish (Poeciliidae: genus Xiphophorus) are a paradigmatic case of sexual selection by sensory exploitation. Female preference for males with a conspicuous "sword" ornament is ancestral, suggesting that male morphology has evolved in response to a preexisting bias. The perceptual mechanisms underlying female mate choice have not been identified, complicating efforts to understand the selection pressures acting on ornament design. We consider two alternative models of receiver behavior, each consistent with previous results. Females could respond either to specific characteristics of the sword or to more general cues, such as the apparent size of potential mates. We showed female swordtails a series of computer-altered video sequences depicting a courting male. Footage of an intact male was preferred strongly to otherwise identical sequences in which portions of the sword had been deleted selectively, but a disembodied courting sword was less attractive than an intact male. There was no difference between responses to an isolated sword and to a swordless male of comparable length, or between an isolated sword and a homogenous background. Female preference for a sworded male was abolished by enlarging the image of a swordless male to compensate for the reduction in length caused by removing the ornament. This pattern of results is consistent with mate choice being mediated by a general preference for large males rather than by specific characters. Similar processes may account for the evolution of exaggerated traits in other systems.