K-band spectroscopy of deeply embedded, young OB stars

We have obtained high resolution (R = 10 000) K-band spectra of candidate young massive stars deeply embedded in high-mass star-forming regions. These objects were selected from a near-infrared survey of 44 regions of high-mass star-formation (Kaper et al. 2006). In these clusters, 38 OB stars are identified whose K-band spectra are dominated by photospheric emission. In almost all those stars, the K-band spectra are indistinguishable from field stars. However, in some stars the profile of the Brγ line is different (less deep, or absent) from those of the O field stars. One of the explanations of these profiles might be an enhanced mass-loss

Painting the ideal home: using art to express visions of technologically supported independent living for older people in North East England

This paper describes the investigation of the development of future technological products to support older people in everyday living through the agency of a community art group. Recent research has identified a number of challenges facing designers seeking to use traditional participatory design approaches to gather technology requirements data from older people. Here, a project is described that sought to get a group of older people to think creatively about their needs and desires for technological support through the medium of paint. The artistic expression technique described in this article allowed the identification of issues that had also been found by previous research that used a range of different techniques. This indicates that the approach shows promise, as it allows information to be gathered in an environment that is comfortable and familiar using methods already known by the participants and which they find enjoyable. It provides a complement (or possible alternative) to standard protocols and has the potential benefit of extracting even richer information as the primary task for participants is enjoyable in its own right and is not associated with an interrogative process. Furthermore, it is argued that some of the key risks of traditional approaches are lessened or removed by the naturalistic setting of this approach

The X-ray nebula around the Seyfert 2 galaxy NGC4388

We report on X-ray emission from the Seyfert 2 galaxy NGC4388 observed with the Chandra X-ray Observatory. A hard X-ray peak is found at the position of the active nucleus suggested by optical and radio observations. Extended soft X-ray emission correlates well with the ionization cone found in optical line emission. A large soft X-ray extension is found up to 16 kpc to the north of the galaxy. Photoionized gas with low ionization parameters (xi<3) appears to be the likely explanation of this emission. The same ionized gas clouds could be responsible for the optical [OIII] emission. Fe K line emission from cold material is found to be extended by a few kpc.Comment: 12 pages, one colour figure included, MNRAS in pres

Field studies using fish biomarkers – How many fish are enough?

Significant efforts are invested in field studies using fish, and it is important to optimize the number of organisms collected to evaluate the possible impacts of contamination. This paper provides ecotoxicologists with the approximate numbers of fish needed to identify statistically significant differences among samples using physiological indices and biochemical markers of fish health. The numbers of fish to collect are reported for ethoxyresorufin-o-deethylase (EROD); ethoxycoumarin-o-deethylase (ECOD), serum sorbitol dehydrogenase (sSDH), stress proteins, gonadosomatic index, liver somatic index, condition factor, and biliary metabolites of polycyclic aromatic hydrocarbons. The number of fish to collect was as few as four for ECOD activity (with a power of 80%), but as high as 106 for CF (with a power of 95%). Achieving statistical significance between sites does not help in the interpretation of the biological significance of a parameter, but well-planned field samplings will maximize the chances of correctly identifying areas of concern

Enhancement of the magnetic anisotropy of nanometer-sized Co clusters: influence of the surface and of the inter-particle interactions

We study the magnetic properties of spherical Co clusters with diameters between 0.8 nm and 5.4 nm (25 to 7500$ atoms) prepared by sequential sputtering of Co and Al2O3. The particle size distribution has been determined from the equilibrium susceptibility and magnetization data and it is compared to previous structural characterizations. The distribution of activation energies was independently obtained from a scaling plot of the ac susceptibility. Combining these two distributions we have accurately determined the effective anisotropy constant Keff. We find that Keff is enhanced with respect to the bulk value and that it is dominated by a strong anisotropy induced at the surface of the clusters. Interactions between the magnetic moments of adjacent layers are shown to increase the effective activation energy barrier for the reversal of the magnetic moments. Finally, this reversal is shown to proceed classically down to the lowest temperature investigated (1.8 K).Comment: 13 figures submitted to Phys. Rev.

Structure, Photophysics and the Order-Disorder Transition to the Beta Phase in Poly(9,9-(di -n,n-octyl)fluorene)

X-ray diffraction, UV-vis absorption and photoluminescence (PL) spectroscopy have been used to study the well-known order-disorder transition (ODT) to the beta phase in poly(9,9-(di n,n-octyl)fluorene)) (PF8) thin film samples through combination of time-dependent and temperature-dependent measurements. The ODT is well described by a simple Avrami picture of one-dimensional nucleation and growth but crystallization, on cooling, proceeds only after molecular-level conformational relaxation to the so called beta phase. Rapid thermal quenching is employed for PF8 studies of pure alpha phase samples while extended low-temperature annealing is used for improved beta phase formation. Low temperature PL studies reveal sharp Franck-Condon type emission bands and, in the beta phase, two distinguishable vibronic sub-bands with energies of approximately 199 and 158 meV at 25 K. This improved molecular level structural order leads to a more complete analysis of the higher-order vibronic bands. A net Huang-Rhys coupling parameter of just under 0.7 is typically observed but the relative contributions by the two distinguishable vibronic sub-bands exhibit an anomalous temperature dependence. The PL studies also identify strongly correlated behavior between the relative beta phase 0-0 PL peak position and peak width. This relationship is modeled under the assumption that emission represents excitons in thermodynamic equilibrium from states at the bottom of a quasi-one-dimensional exciton band. The crystalline phase, as observed in annealed thin-film samples, has scattering peaks which are incompatible with a simple hexagonal packing of the PF8 chains.Comment: Submitted to PRB, 12 files; 1 tex, 1 bbl, 10 eps figure

Gaining and maintaining a competitive edge: Evidence from CSA members and farmers on local food marketing strategies

Community-supported agriculture (CSA) is a widely-used approach for farmers to sell directly to consumers. We used the product, place, price, and promotion (4P) marketing mix framework to examine characteristics that help farms offering CSA maintain member satisfaction and thus competitiveness. We conducted semi-structured interviews with 20 CSA members and 24 CSA farmers in four states. CSA members additionally completed a modified choice experiment. Qualitative data were coded iteratively, and choice experiment data were summarized and compared across scenarios. CSA members and farmers were motivated by a range of personal, social, environmental, and economic objectives. Members favored high-quality staple vegetables (e.g., lettuce, green beans), ideally produced organically. Trust and a sense of personal connection with the farmer comprised part of the "value added" of CSA participation. Time and location of share pick-up were very important; thus, farmers tried to offer convenient sites or an enriched pick-up experience. Small changes in price appeared unlikely to impact participation among current members. Social networks and word-of-mouth were powerful for marketing, but may limit the ability to reach diverse populations. Future research should examine the ability of CSAs to meet the needs of those who do not currently participate

Detecting a stochastic gravitational wave background with the Laser Interferometer Space Antenna

The random superposition of many weak sources will produce a stochastic background of gravitational waves that may dominate the response of the LISA (Laser Interferometer Space Antenna) gravitational wave observatory. Unless something can be done to distinguish between a stochastic background and detector noise, the two will combine to form an effective noise floor for the detector. Two methods have been proposed to solve this problem. The first is to cross-correlate the output of two independent interferometers. The second is an ingenious scheme for monitoring the instrument noise by operating LISA as a Sagnac interferometer. Here we derive the optimal orbital alignment for cross-correlating a pair of LISA detectors, and provide the first analytic derivation of the Sagnac sensitivity curve.Comment: 9 pages, 11 figures. Significant changes to the noise estimate

Chronic myelomonocytic leukemia in younger patients : molecular and cytogenetic predictors of survival and treatment outcome

In patients with chronic myelomonocytic leukemia (CMML), age>65 years is an adverse prognostic factor. Our objective in the current study was to examine risk factors for survival and treatment outcome in 261 'young' adults with CMML, as defined by age \u2a7d65 years. In multivariable analysis, lower HB (P=0.01), higher circulating blast % (P=0.002), ASXL1 (P=0.0007) and SRSF2 mutations (P=0.008) and Mayo-French cytogenetic stratification (P=0.04) negatively impacted survival. Similarly, leukemia-free survival was independently affected by higher circulating blast % (P<0.0001), higher bone marrow blast % (P=0.0007) and the presence of circulating immature myeloid cells (P=0.0002). Seventy-five (29%) patients received hypomethylating agents (HMA), with the median number of cycles being 5, and the median duration of therapy being 5 months. The over-all response rate was 40% for azacitidine and 30% for decitabine. Fifty-three (24%) patients underwent an allogeneic hematopoietic stem cell transplant (AHSCT), with a response rate of 56% and a non-relapse mortality of 19%. Survival in young adults with CMML, although higher than in older patients, is poor and even worse in the presence of ASXL1 and SRSF2 mutations. Treatment outcome was more impressive with AHSCT than with HMA and neither was influenced by ASXL1/SRSF2 mutations or karyotype