Phase-channel dynamics reveal the role of impurities and screening in a quasi-one-dimensional charge-density wave system.

Charge density waves (CDWs), i.e. the periodic spatial modulation of coupled electronic and lattice density, are ubiquitous in low-dimensional conductors and have taken on renewed relevance due their role in state-of-the-art materials, e.g. high-T c superconductors, topological insulators and low-dimensional carbon. As CDWs are described by a complex order parameter to represent both the amplitude and phase, they are formally analogous to BCS superconductors and spin-waves, providing a prototype of collective phenomena for the further development of field theories and ab-initio calculations of complex solids. The low-energy excitations are mixed electron-phonon quanta which ideally separate into an amplitude and phase channel, and provide a sensitive probe of the ground state and non-equilibrium dynamics, including ultrafast photoinduced phase transitions. While recent studies of the amplitude modes have brought substantial progress aided by a phenomenological Ginzburg-Landau framework, we focus here on the phase modes using ultrafast terahertz spectroscopy. Experiments on K0.3MoO3 provide a more complete picture, and reveal a high sensitivity to interactions with impurities and screening effects from photogenerated carriers, both of which can be accounted for by generalizations of the model. Moreover, our considerations emphasize the need to revisit the treatment of inherent electronic damping in quantum-mechanical CDW theories.

Application of the health literacy framework to diet-related cancer prevention conversations of older immigrant women to Canada.

Health literacy, conceptualized as a framework involving basic (functional), interactive and critical skill sets, is a key determinant of health. Application of the health literacy framework (HLF) to immigrant populations has been limited. Our objective was to apply the HLF to discourses about diet-related colon cancer prevention among English-as-a-Second-Language (ESL) immigrant women. We also explored whether these discussions could inform the development of culturally appropriate information and potentially increase health literacy. Interviews were conducted with 64 older Spanish-speaking ESL immigrant women. Directed content analysis guided by the HLF was used to identify themes. Diet-related conversations were initiated by 43 (67%) participants. Four themes were identified: general information requests-low functional health literacy (FHL) (n = 23/43), specific nutrition inquiries-high FHL (n = 17/43), actions for healthy eating-low interactive health literacy (IHL) (n = 8/43) and community communication issues-high IHL (n = 3/43). No conversations representing critical health literacy were identified. Five women discussed both FHL and IHL themes. Women's diet-related conversations followed a continuum of increasing information needs supporting the HLF.

Cancer information comprehension by English-as-a-second-language immigrant women.

Limited acculturation and socioeconomic factors have been associated with lower participation in cancer screening. Limited comprehension of cancer prevention information may contribute to this association. The authors used a stepwise linear regression to model acculturation and socioeconomic factors as predictors of comprehension (colon cancer and general health information) and screening intention in a sample of 78 Spanish-speaking immigrant women in Canada. The authors used the McNemar test to look for changes in women's screening intention. They used the Bidimensional Acculturation Scale, a language-based scale, to assess acculturation. Among English-as-a-second-language immigrant women, acculturation, television and Internet use, age, and Spanish-language education predicted comprehension of cancer prevention information, F(3, 69) = 6.76, p < .001, R(2) = .23. These variables also predicted comprehension of general health information, via the short form of the Test of Functional Health Literacy in Adults, F(4, 68) = 12.13, p < .001, R(2) = .42; and the Rapid Estimate of Adult Literacy in Medicine, F(2, 70) = 7.54, p = .001, R(2) = .17. However, the variables did not predict screening intention. More women expressed intention to be screened after reading the cancer prevention information than expected by chance alone, p = .002. Acculturation is an important influence on the comprehension of health information by older English-as-a-second-language immigrant women. However, other culture-related factors not measured by the Bidimensional Acculturation Scale likely influence their exposure to and understanding of health and cancer prevention information.

Coherent electro-optical detection of terahertz radiation from an optical parametric oscillator.

We report the realization of coherent electro-optical detection of nanosecond terahertz (THz) pulses from an optical parametric oscillator, which is pumped by a Q-switched nanosecond Nd:YVO4 laser at 1064 nm and emits at approximately 1.5 THz. The beam profile and wavefront of the THz beam at focus are electro-optically characterized toward the realization of a real-time THz camera. A peak dynamic range of approximately 37 dB/radical Hz is achieved with single-pixel detection.

Literacy and cancer anxiety as predictors of health status: an exploratory study.

BACKGROUND: Socioeconomic status is a strong correlate of health status. Low literacy is associated with barriers to health information and anxiety about disease. METHODS: Using 2003 Health Information National Trends Survey data, the relationship between self-reported health status and proxy measures of literacy (Hispanic ethnicity, education, and media variables), cancer anxiety, and cancer information seeking were assessed. RESULTS: Low literacy, measured by proxy variables, was associated with a greater likelihood of reporting fair-poor health status. Reporting excellent-good health status was less likely for people reporting frustration finding cancer information (odds ratio [OR] 0.68, 95% confidence interval [CI] 0.52-0.89), worry about cancer (OR 0.56, 95% CI 0.35-0.89), and increased chance of getting cancer (OR 3.5, 95% CI 0.24-0.51). CONCLUSION: Proxy variables for literacy suggest a possible contribution to health status disparities.

Diagnosing water content in paper by terahertz radiation.

We explore the application of terahertz spectroscopic techniques for the remote determination of the water content of paper. The aim is the development of a rapid diagnostic imaging tool applicable in paper fabrication processes. THz radiation offers a high sensitivity for water, a good spatial resolution, and insensitivity to scattering at the paper surface. The advent of THz cameras makes fast large-area image detectors feasible. In this paper, we show for the case of a 0.6-THz fixed-frequency system, that the water content of paper can be determined with high accuracy. We demonstrate a quantitative (calibrated) method for determining the moisture content in paper based on extinction and phase measurements in the lower THz range with a spatial resolution in the mm-range and scanning times below two minutes.

Readability and cultural sensitivity of web-based patient decision aids for cancer screening and treatment: a systematic review.

Decision aids (DA) can inform cancer screening. We conducted a systematic review of web-based, cancer DA to evaluate their appropriateness for use with low literacy and diverse culture groups. Eighty-one Internet DA were found searching five databases (Pubmed-Medline; Web of Science/SSCI; Cancerlit; CINAHL; and Google) and the Cochrane decision aid inventory. Twenty-three met key inclusion criteria of (1) informing cancer screening or treatment decisions, (2) being patient or consumer oriented, and (3) conforming to the Cochrane definition of DA. DA were evaluated using the International Patient Decision Aid Standards checklist, the Cultural Sensitivity Assessment Tool (CSAT), the Cultural Sensitivity Assessment Checklist (CSAC), and the SMOG readability formula. DA had a high readability with 74% (n = 17) written at the grade 10 - 13, 22% (n = 5) at the grade 9, and 4% (n = 1) at the grade 8 level. Visual aids were used in 35% (n = 8) to present probability information. Written information was complemented with video or audio components in 35% (n = 8). Most (91%, n = 21) were developed for generic audiences, while 9% (n = 2) specified a cultural group. Although DA enabled a step-by-step movement through the website, none allowed key word searches and only 65% permitted document printing. Most DA included difficult texts and were not focused for specific cultural groups.

Generation and characterization of 0.6-THz polarization domain-wall trains in an ultralow-birefringence spun fiber.

Polarization domain-wall (PDW) trains have been generated at a repetition rate of 0.6 THz in an ultralow-birefringence spun optical fiber and measured by use of an adapted frequency-resolved optical gating technique. Characterization of the intensity and the phase of the PDW train shows complete switching between adjacent domains of counterrotating circular polarizations and directly confirms predictions based on numerical simulations of the incoherently coupled nonlinear Schrödinger equations.

Complete pulse characterization at 1.5 mum by cross-phase modulation in optical fibers.

Cross-phase modulation in optical fibers has been used for complete characterization of ultrashort pulses by a modified frequency-resolved optical gating (FROG) measurement technique. This technique has been used for characterization of picosecond pulses at 1.5mum with energy as low as 24 pJ, and the results are in excellent agreement with second-harmonic generation (SHG)-FROG characterization. The use of an optical waveguide gives measurement sensitivity comparable with that of SHG-FROG but without any temporal ambiguity in the retrieved pulse.

Quasi-phase-matched modulation instability in birefringent fibers.

The phase-sensitive nature of polarization modulation instability has been demonstrated in optical fibers whose birefringence has been manipulated to generate phase mismatches. Quasi-phase-matched modulation instability has been demonstrated, and the gain of the quasi-phase-matched sidebands has been investigated. The results are in good agreement with experiment.