Threat and fear of pain induces attentional bias to pain words: An eye-tracking study.

BACKGROUND: This study aimed to investigate the effects of fear of pain (FOP) and threat on attentional biases, using eye-tracking methods. METHOD: One hundred and seven undergraduate students were randomized to receive threatening or reassuring information about the cold pressor task; and divided into high and low FOP groups. Participants completed the dot-probe task, while their eye movements were tracked. RESULTS: Results showed that those who received threatening information were less likely to have their first fixation on pain words, particularly affective pain words. Furthermore, under conditions of high threat, the high FOP group who did fixate on affective pain words, fixated more quickly than for sensory pain words, whereas the opposite was the case under low threat. In regression analyses, initial vigilance towards affective pain words was a significant predictor of reporting pain more quickly on the cold pressor. CONCLUSIONS: Taken together, these results suggest that initial vigilance of affective pain stimuli predicts actual hypervigilance to an acute experimental pain task. However, under conditions of high threat, participants show evidence of avoidance of affective pain words, even though when they do fixate on these stimuli, the high FOP group does so more quickly. These results confirm that attentional processes, characterized by vigilance avoidance, appear important. SIGNIFICANCE: Interventions that change attention towards pain to reduce vigilance and subsequent avoidance may be indicated to improve pain outcomes.

Dangerous liaisons: doctors-in-training and the pharmaceutical industry.

Interaction between doctors and the pharmaceutical industry is long-standing and ingrained in modern practice. Doctors-in-training are at a vulnerable stage of their careers, both in requiring knowledge and forming lasting relationships. There is evidence that limiting contact between industry and junior doctors has a positive effect on subsequent clinical behaviour. Currently in Australia, there is no limitation on pharmaceutical representatives approaching doctors-in-training, and the majority of education sessions are sponsored by pharmaceutical companies. This purposefully creates a sense of reciprocity, which may have adverse long-term consequences on attitudes, behaviours and patient care. Several guidelines exist that may assist junior doctors in navigating these potential interactions, most notably the Royal Australasian College of Physicians' own Guidelines for Ethical Relationships between Physicians and Industry. Despite this, there is no reflection of its importance or necessity within subspecialty curricula. This should be rectified, to the benefit of both the profession and public.

Quantum defect theory of dipole and vibronic mixing in Rydberg states of CaF.

The Rydberg spectra of CaF combine the simplicity of a single electron outside a doubly closed-shell Ca2+F- ion core with the exceptional polarity of the ion core. A global multichannel quantum defect (MQDT) fit to 612 previously assigned levels, 507 from n approximately = 12-18, N=0-14, v+=1, 97 from n approximately = 9-10, N=0-14, v+=2, and 8 from n approximately = 7, N=3-10, v+=3, produces the complete L=0-3 quantum defect matrix mu (with the exception of one element) and 19 of 20 elements of the partial differentialmu/differentialR matrix, as well as the molecular constants of the CaFX 1sigma+ state [omega(e)+=694.58(14), omega(e)x(e+)=2.559(40), B(e+)=0.373 07(16) cm(-1), and the v=0, N=0 to v(+)=0, N(+)=0 ionization energy, 46,996.40(8) cm(-1)]. This experimentally determined mu(R) matrix is unusual in the completeness of its representation of the spectrum of both core-penetrating and nonpenetrating Rydberg series, including both local perturbations and vibrational autoionization rates, as well as all dynamical processes encoded in the spectrum that result from the scattering (at negative energy) of the Rydberg electron off the Ca2+F- ion core. The MQDT theory is presented in a form that clarifies the relationships of the reaction (K) and phase (P) matrices of MQDT to effective Hamiltonian models for local interactions between accidentally near degenerate levels. In particular, a Hund's case (b) like representation of the Hamiltonian is described in which the rovibronic K matrix is diagonalized and the P matrix, which contains information about the v+, N+ eigenstates of the ion, becomes nondiagonal.

Quantitative gas sensing by backscatter-absorption measurements of a pseudorandom code modulated lambda ~ 8-microm quantum cascade laser.

We have demonstrated quantitative chemical vapor detection with a multimode quantum cascade (QC) laser. Experiments incorporated pseudorandom code (PRC) modulation of the laser intensity to permit sensitive absorption measurements of isopropanol vapor at 8.0micro . The demonstration shows the practicality of one technical approach for implementing low-peak-power QC lasers in the transmitter portion of a differential absorption lidar (DIAL) system. With a 31-chip, 300-ns/chip PRC sequence, the measured isopropanol detection limit was 12 parts in 10(6) by volume times meters (~3x10(-3) absorption) for a simple backscatter-absorption measurement configuration.

Tunable Fabry-Perot etalon-based long-wavelength infrared imaging spectroradiometer.

Imaging spectrometry enables passive, stand-off detection and analysis of the chemical composition of gas plumes and surfaces over wide geographic areas. We describe the use of a long-wavelength infrared imaging spectroradiometer, comprised of a low-order tunable Fabry-Perot etalon coupled to a HgCdTe detector array, to perform multispectral detection of chemical vapor plumes. The tunable Fabry-Perot etalon used in this research provides coverage of the 9.5-14-microm spectral region with a resolution of 7-9 cm(-1). The etalon-based imaging system provides the opportunity to image a scene at only those wavelengths needed for chemical species identification and quantification and thereby minimize the data volume necessary for selective species detection. We present initial results using a brassboard imaging system for stand-off detection and quantification of chemical vapor plumes against near-ambient-temperature backgrounds. These data show detection limits of 22 parts per million by volume times meter (ppmv x m) and 0.6 ppmv x m for dimethyl methyphosphonate and SF6, respectively, for a gas/background DeltaT of 6 K. The system noise-equivalent spectral radiance is approximately 2 microW cm(-2) sr(-1) microm(-1). Model calculations are presented comparing the measured sensitivity of the sensor to the anticipated signal levels for two chemical release scenarios.

Frequency-agile bandpass filter for direct detection lidar receivers.

We discuss the development of a frequency-agile receiver for CO(2) laser-based differential absorption lidar (DIAL) systems. The receiver is based on the insertion of a low-order tunable etalon into the detector field of view. The incorporation of the etalon into the receiver reduces system noise by decreasing the instantaneous spectral bandwidth of the IR detector to a narrow wavelength range centered on the transmitted CO(2) laser line, thereby improving the overall D* of the detection system. A consideration of overall lidar system performance results in a projected factor of a 2-7 reduction in detector system noise, depending on the characteristics of the environment being probed. These improvements can play a key role in extending the ability of DIAL systems to monitor chemical releases from long standoff distances.

Real-Time Quantitative Analysis of Combustion-Generated Polycyclic Aromatic Hydrocarbons by Resonance-Enhanced Multiphoton Ionization Time-of-Flight Mass Spectrometry.

We have combined resonance-enhanced multiphoton ionization (REMPI) time-of-flight mass spectrometry with on-line flame sampling to determine the centerline concentrations of naphthalene, fluorene, and anthracene in a pure methane + oxygen/argon (1:5) diffusion flame. Naphthalene concentrations between 100 parts per billion by volume (ppbV) and 6 parts per million by volume (ppmV) and fluorene concentrations below 50 ppbV are determined using one-color REMPI on jet-cooled samples extracted from the flame; anthracene concentrations in the 5-40 ppbV range are determined using two-color REMPI. The REMPI ion signals are converted to absolute concentrations in real time by performing gas-phase standard additions to the flame sample. Isomer-selective detection of larger polycyclic aromatic hydrocarbons, such as perylene and benzo[a]pyrene, is possible using the two-color REMPI approach.