Mapping of ionomic traits in Mimulus guttatus reveals Mo and Cd QTLs that colocalize with MOT1 homologues

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An Organisational Approach to Stress and Burnout in Health Care Services

The relationships between interpersonal sources of stress, support and health outcome for four HIV care teams were studied using a questionnaire survey design. Additional qualitative information was obtained from individual interview with participants and a team discussion day. There were limitations, however, to the interpretation of the data obtained in this study. This was because of the constraints of cross-sectional survey design as well as the relatively small numbers of participants for some analyses. Overall, the results obtained in this study suggested that collegial relationships are important mediators of stress at work. Multidisciplinary team sources of stress in particular were found to be related to increased GHQ-12 caseness. Manager and same profession colleague support were found to be related to reduced perceptions of stress from manager, same profession colleagues and multidisciplinary team sources of stress; but not from client and client's family sources of stress. Personality differences appeared to contribute to conflict and stress in same profession teams. Differences in professional orientation, lack of leadership structure, power imbalance, task and role ambiguity, and competition for resources and clients appeared to be central to conflict and stress in multidisciplinary teams. Multidisciplinary team and manager sources of stress were higher for participants who had been in HIV care services for more than 6 years. HIV professionals who had been in the HIV speciality for longer also rated the multidisciplinary team as less supportive. Length of time in service was also associated with decreased self efficacy, age being taken into account. It was concluded that changes in HIV service structure, resources, client contact and collegial relationships in recent years, related to improved effects of combination anti-retroviral drug therapies for service users, might have been particularly stressful for the HIV staff in this study

The ‘expat factor’: the influence of working time on women's decisions to undertake international assignments in the oil and gas industry

This article examines the effect of working time on women’s willingness to go on expatriate assignments in the oil and gas exploration and production sector. The research draws upon an analysis of two case study firms’ international assignment and working time policies, semi-structured interviews with 14 Human Resource staff responsible for policy design and implementation, and a survey of the views of 71 women expatriates, supported by in-depth interviews with 26 of the survey respondents. The research identifies an ‘expat factor’: assignees state that long hours are inherent in expatriation and necessary to further their careers. However in practice, working time is not excessive and flexible working practices are utilised. Hours of work have little effect on women’s decisions to undertake long-term assignments but alternatives such as short-term and commuter assignments are unpopular as their working patterns are disruptive to family life. This article contributes to theory development by linking two discrete frameworks that explain women’s career choices when they strive to balance their career goals with their families and by identifying a career compromise threshold when expatriation is rejected in favour of family considerations. A model is proposed to link working time/patterns to women’s international assignment participation

Analyzing the phonon-polariton response of silicon Carbide microparticles and nanoparticles by use of the Bondary Element Method

We present our investigation of the torque exerted on dielectric elliptical cylinders by highly focused laser beams. The calculations are performed with rigorous diffraction theory, and the size-dependent torque is analyzed as a function of the axis ratio. It is found that highly elongated particles will experience a reversal of the torque for a radius that is approximately one third of the wavelength. This effect is attributed to interference effects inside the structure due to multiple reflections of the incoming wave. The evolution from a perfectly sinusoidal angular dependence of the torque to a more complicated pattern for increasing particle size is presented in detail. © 2005 Optical Society of America

Determinants of response to a parent questionnaire about development and behaviour in 3 year olds: European multicentre study of congenital toxoplasmosis.

Background: We aimed to determine how response to a parent-completed postal questionnaire measuring development, behaviour, impairment, and parental concerns and anxiety, varies in different European centres. Methods: Prospective cohort study of 3 year old children, with and without congenital toxoplasmosis, who were identified by prenatal or neonatal screening for toxoplasmosis in 11 centres in 7 countries. Parents were mailed a questionnaire that comprised all or part of existing validated tools. We determined the effect of characteristics of the centre and child on response, age at questionnaire completion, and response to child drawing tasks. Results: The questionnaire took 21 minutes to complete on average. 67% (714/1058) of parents responded. Few parents (60/1058) refused to participate. The strongest determinants of response were the score for organisational attributes of the study centre (such as direct involvement in follow up and access to an address register), and infection with congenital toxoplasmosis. Age at completion was associated with study centre, presence of neurological abnormalities in early infancy, and duration of prenatal treatment. Completion rates for individual questions exceeded 92% except for child completed drawings of a man (70%), which were completed more by girls, older children, and in certain centres. Conclusion: Differences in response across European centres were predominantly related to the organisation of follow up and access to correct addresses. The questionnaire was acceptable in all six countries and offers a low cost tool for assessing development, behaviour, and parental concerns and anxiety, in multinational studies

Photonic bandgaps for grating-coupled waveguide modes with a silver tunnel barrier

Copyright © 2007 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft. This is the published version of an article published in New Journal of Physics Vol. 9, article 251. DOI: 10.1088/1367-2630/9/8/251The optical properties of a periodically modulated photoresist waveguide structure has been explored using the Kretschmann–Raether configuration with a thin silver tunnel barrier. A detailed experimental study of how wavelength-scale periodic texture modifies the dispersion of the guided modes in the visible range for a wide range of azimuthal angles is presented. Fitting the observed in-plane momenta of the modes to predictions from a multilayer, multishape differential grating theory model allows the identities of each of the modes to be confirmed. In addition, the intensities obtained experimentally are compared favourably with those predicted from a theoretical model. Such a waveguide structure can produce not only the photonic bandgaps at the Brillouin zone boundary, but also bandgaps within the Brillouin zone caused by the Bragg scattered guided modes anti-crossing with the unscattered modes. All of these photonic bandgaps have potential applications controlling spontaneous emission in devices

Asynchronous Sampling Rate Conversions in Digital Communications Systems

The problem of resampling digital signals at an output sampling rate that is incommensurate with the input sampling rate is the topic of this paper. This problem is often encountered in practice, as for example in the multiplexing of video signals from different sources for the purpose of distribution. There are basically two approaches to resample the signals. Both approaches are thoroughly described and practical circuits for hardware implementation are provided. A comparison of the two circuits presented in the paper shows that one circuit requires a division to compute the new sampling times. This time scaling operation adds complexity to the implementation with no performance advantage over the other circuit, and makes the “division free” circuit the preferred one for resampling

Foliar lead uptake by lettuce exposed to atmospheric fallouts

Metal uptake by plants occurs by soil−root transfer but also by direct transfer of contaminants from the atmosphere to the shoots. This second pathway may be particularly important in kitchen gardens near industrial plants. The mechanisms of foliar uptake of lead by lettuce (Lactuca sativa) exposed to the atmospheric fallouts of a lead-recycling plant were studied. After 43 days of exposure, the thoroughly washed leaves contained 335 ± 50 mg Pb kg−1 (dry weight). Micro-X-ray fluorescence mappings evidenced Pb-rich spots of a few hundreds of micrometers in diameter located in necrotic zones. These spots were more abundant at the base of the central nervure. Environmental scanning electron microscopy coupled with energy dispersive X-ray microanalysis showed that smaller particles (a few micrometers in diameter) were also present in other regions of the leaves, often located beneath the leaf surface. In addition, submicrometric particles were observed inside stomatal openings. Raman microspectrometry analyses of the leaves identified smelter-originated Pb minerals but also secondary phases likely resulting from the weathering of original particles. On the basis of these observations, several pathways for foliar lead uptake are discussed. A better understanding of these mechanisms may be of interest for risk assessment of population exposure to atmospheric metal contamination

Genome-wide association mapping for grain manganese in rice (Oryza sativa L.) using a multi-experiment approach

Funding Information: Acknowledgements This research was partly supported by the US National Science Foundation, Plant Genome Research Program (grant #IOS 0701119 to DES, MLG and SRMP) and The US National Institutes of Health (grant 2P4ES007373 to MLG and DES). PR is a PhD student funded by the Thai Government Scholarship.Peer reviewedPostprin

Cisplatin and Oxaliplatin Toxicity: Importance of Cochlear Kinetics as a Determinant for Ototoxicity

Background Cisplatin is a commonly used platinum anti-cancer drug. Regrettably cisplatin has dose-limiting ototoxic side effects, e.g. the drug can induce an irreversible hearing loss. The ototoxic mechanisms of cisplatin have not been elucidated in the human ear and no clinically useful oto-protectors are yet available. Cisplatin is a necessary part of many treatment regimes. Its beneficial therapeutic effects might be reduced if cisplatin was excluded from the treatment in order to protect the hearing function. In this work the ototoxic effects of cisplatin are studied with the aim to better understand the mechanisms behind the irreversible hearing loss induced by this drug. Oxaliplatin is a second generation platinum-derivative anti-cancer drug, free from ototoxic side effects in clinical practice. The effects of oxaliplatin on the inner ear have been studied in this work and the results are compared with cisplatin treatment. The two drugs differ regarding both anti-cancer effects and side effects, which could be attributed to differences in pharmacokinetic factors, cellular uptake and apoptotic mechanisms. The thioredoxin redox system with the enzyme thioredoxin reductase (TrxR) was studied in cochleae due to a suggested DNA-independent apoptotic mechanism of the hair cells. The cochlear pharmacokinetics of cisplatin was assessed and the transport protein organic cation transporter 2 (OCT2) was studied in relation to the ototoxic effect of cisplatin. Material and methods Cultured human colon carcinoma cells and cell cultures of rat organ of Corti were used for apoptosis studies in vitro following exposure to cisplatin and oxaliplatin. Cisplatin and oxaliplatin were administered i.v. to guinea pigs, followed by in vivo sampling of blood, cerebrospinal fluid (CSF) and scala tympani (ST) perilymph. Liquid chromatography with post-column derivatization was used to determine the concentration of parent drug in the samples. Electrophysiological hearing thresholds and the loss of hair cells were assessed to evaluate their ototoxic effects. Phenformin, a potential blocker of OCT2 was administered and the ototoxic side effect of cisplatin was evaluated. For immunohistochemical studies, cochlea from rat, guinea pig and pig were used, where TrxR and OCT2 were evaluated in the cochlea. TrxR-assays were used to measure the TrxR activity in cochlear tissue, both in vivo and in vitro. Results The results from the in vitro studies showed that addition of either cisplatin or oxaliplatin to the culture medium in organ of Corti cell cultures caused a similar amount of outer hair cell loss and inhibition of TrxR activity. Cisplatin exposure to cultured human colon carcinoma cells also reduced the activity of TrxR. The results from the in vivo studies showed that a considerable concentration of cisplatin was present in ST perilymph as compared with weak concentrations of oxaliplatin after high dose oxaliplatin i.v. Ten minutes after cisplatin administration, its concentration in ST perilymph was 4-fold higher in the basal turn of the cochlea as compared to the apex. Cisplatin could be analysed in ST perilymph for up to 120 min. Phenformin i.v. did not reduce the ototoxic side-effect of cisplatin. Positive immunoreactivity to TrxR was evident in both hair cells and spiral ganglion cells. Futhermore, OCT2 was expressed in the supporting cells of organ of Corti and in the spiral ganglion cells. Conclusion The transport of cisplatin to the vulnerable cells of hearing seems to be of major importance for the ototoxic effects. An early high concentration of cisplatin in the base of the cochlea and delayed elimination of cisplatin from ST perilymph may be related to the cisplatin-induced loss of outer hair cells in the basal turn of the cochlea. Cisplatin and oxaliplatin both cause similar ototoxic effects when the organ of Corti is directly exposed in vitro. The thioredoxin redox system with the TrxR enzyme may well play a critical role in cisplatininduced ototoxicity. The presence of OCT2 in the supporting cells indicates that this transport protein is primarily not involved in the uptake of cisplatin from the systemic circulation but rather from the deeper compartments of the cochlea. The knowledge elicited in this work will hopefully suggest objectives for further studies in order to develop oto-protective treatments to preserve the hearing of cisplatin treated patients