Magnetic Fields in Star-Forming Molecular Clouds I. The First Polarimetry of OMC-3 in Orion A

The first polarimetric images of the OMC-3 region of the Orion A filamentary molecular cloud are presented. Using the JCMT, we have detected polarized thermal emission at 850 microns from dust along a 6' length of the dense filament. The polarization pattern is highly ordered and is aligned with the filament throughout most of the region. The plane-of-sky magnetic field direction is perpendicular to the measured polarization. The mean percentage polarization is 4.2% with a 1 sigma dispersion of 1%. This region is part of the integral-shaped filament, and active star formation is ongoing along its length. The protostellar outflow directions do not appear to be consistently correlated with the direction of the plane-of-sky field or the filament structure itself. Depolarization toward the filament center, previously detected in many other star-forming cores and protostars, is also evident in our data. (abstract abridged)Comment: 9 pages plus 2 figures (1 colour); accepted for publication in the March 10, 2000 issue (vol. 531 #2) of The Astrophysical Journa

Exploring Buddhism as a ‘Tool’ to Support Well-Being: An Interpretative Phenomenological Analysis of Western Adopters’ Experiences

Buddhism is an ancient religion and philosophy of living that is practised worldwide. More recent interest in mindfulness as a practice and intervention in the West has highlighted Buddhist-derived concepts as useful in supporting health and well-being. As a result, the desire to understand Buddhism in its more complete form has strengthened. Although research into mindfulness and compassion is growing, there is a new interest in second-generation mindfulness, i.e. interventions that draw upon a more holistic use of Buddhist practices. To date, little research has explored this in Western contexts. For the current study, Nichiren Buddhists from the United Kingdom who had been practising for at least three years were recruited. Semi-structured interviews were conducted to explore their experience of this practice and how it informed their approach to daily life and, in particular, their health and well-being. Interpretive phenomenological analysis was employed as a method to understand the participants’ experiences. Three themes were generated using an inductive approach: (1) finding meaning—“All experiences have got so much value now”— which reflected the participants’ determination to seek purpose and value in all aspects of their life; (2) Buddhism as a needed ‘tool’—“I use it all the time”—which revealed their practice as an important method to help them manage their lives; and (3) agency—“I’m in control of my destiny”—which highlighted the participants’ engagement (supported by their Buddhist practice) in taking responsibility for their actions and responses. Findings indicate the need for future studies to further explore Buddhism as a mechanism for enhancing and sustaining well-being

Effect of continuous gamma-ray exposure on performance of learned tasks and effect of subsequent fractionated exposures on blood-forming tissue

Sixteen monkeys trained to perform continuous and discrete-avoidance and fixed-ratio tasks with visual and auditory cues were performance-tested before, during, and after 10-day gamma-ray exposures totaling 0, 500, 750, and 1000 rads. Approximately 14 months after the performance-test exposures, surviving animals were exposed to 100-rad gamma-ray fractions at 56-day intervals to observe injury and recovery patterns of blood-forming tissues. The fixed-ratio, food-reward task performance showed a transient decline in all dose groups within 24 hours of the start of gamma-ray exposure, followed by recovery to normal food-consumption levels within 48 to 72 hours. Avoidance tasks were performed successfully by all groups during the 10-day exposure, but reaction times of the two higher dose-rate groups in which animals received 3 and 4 rads per hour or total doses of 750 and 1000 rads, respectively, were somewhat slower

Millimeter wave satellite concepts, volume 1

The identification of technologies necessary for development of millimeter spectrum communication satellites was examined from a system point of view. Development of methodology based on the technical requirements of potential services that might be assigned to millimeter wave bands for identifying the viable and appropriate technologies for future NASA millimeter research and development programs, and testing of this methodology with selected user applications and services were the goals of the program. The entire communications network, both ground and space subsystems was studied. Cost, weight, and performance models for the subsystems, conceptual design for point-to-point and broadcast communications satellites, and analytic relationships between subsystem parameters and an overall link performance are discussed along with baseline conceptual systems, sensitivity studies, model adjustment analyses, identification of critical technologies and their risks, and brief research and development program scenarios for the technologies judged to be moderate or extensive risks. Identification of technologies for millimeter satellite communication systems, and assessment of the relative risks of these technologies, was accomplished through subsystem modeling and link optimization for both point-to-point and broadcast applications

Relativistic quantum mechanics and the Bohmian interpretation

Conventional relativistic quantum mechanics, based on the Klein-Gordon equation, does not possess a natural probabilistic interpretation in configuration space. The Bohmian interpretation, in which probabilities play a secondary role, provides a viable interpretation of relativistic quantum mechanics. We formulate the Bohmian interpretation of many-particle wave functions in a Lorentz-covariant way. In contrast with the nonrelativistic case, the relativistic Bohmian interpretation may lead to measurable predictions on particle positions even when the conventional interpretation does not lead to such predictions.Comment: 10 pages, revised, to appear in Found. Phys. Let

What Scope is There for Adopting Evidence-Informed Teaching in Software Engineering?

Context: In teaching about software engineering we currently make little use of any empirical knowledge. Aim: To examine the outcomes available from the use of Evidence-Based Software Engineering (EBSE) practices, so as to identify where these can provide support for, and inform, teaching activities. Method: We have examined all known secondary studies published up to the end of 2009, together with those published in major journals to mid-2011, and identified where these provide practical results that are relevant to student needs. Results: Starting with 145 candidate systematic literature reviews (SLRs), we were able to identify and classify potentially useful teaching material from 43 of them. Conclusions: EBSE can potentially lend authority to our teaching, although the coverage of key topics is uneven. Additionally, mapping studies can provide support for research-led teaching

Device modelling and model verification for the Euclid CCD273 detector

Euclid is one of the M-class missions selected for the next phase of ESA’s long-term Cosmic Vision programme. The primary goal of this mission is to observe the distribution and shapes of distant galaxies, with the aim of mapping and characterising the dark energy which makes up about 70% of the universe. This will be achieved by measuring the effects of weak lensing on the captured images, in terms of the distortion caused to the elipticity of galaxy shapes [1]. The e2v CCD273 was designed for the Euclid mission and is adapted from an older design (the CCD203) with changes made to improve CTE under irradiation by solar protons. Reducing the effects of radiation damage in the image sensor will result in images which have minimal distortion. This paper is focused on the on-going development and verification of 3D device models and their integration with Monte Carlo radiation damage models. Parameters such as charge interaction volume versus signal size, pixel full well capacity, and charge transfer behaviour for both the parallel and serial registers will be discussed. The main mission goals are aimed at measuring distortion due to weak lensing, so it is important to differentiate this from distortion due to radiation damage. This work will eventually lead to a method of post processing images to remove the effects of radiation damage

Studying charge-trapping defects within the silicon lattice of a p-channel CCD using a single-trap “pumping” technique.

The goals of future space missions such as Euclid require unprecedented positional accuracy from the responsible detector. Charge coupled devices (CCDs) can be manufactured with exceptional charge transfer properties; however the harsh radiation environment of space leads to damage within the silicon lattice, predominantly through proton collisions. The resulting lattice defects can trap charge, degrading the positional accuracy and reducing the useful operating time of a detector. Mitigation of such effects requires precise knowledge of defects and their effects on charge transfer within a CCD. We have used the technique of single-trap ``pumping'' to study two such charge trapping defects; the silicon divacancy and the carbon interstitial, in a p-channel CCD. We show this technique can be used to give accurate information about trap parameters required for radiation damage models and correction algorithms. We also discuss some unexpected results from studying defects in this way

Resonances in Ferromagnetic Gratings Detected by Microwave Photoconductivity

We investigate the impact of microwave excited spin excitations on the DC charge transport in a ferromagnetic (FM) grating. We observe both resonant and nonresonant microwave photoresistance. Resonant features are identified as the ferromagnetic resonance (FMR) and ferromagnetic antiresonance (FMAR). A macroscopic model based on Maxwell and Landau-Lifschitz equations reveals the macroscopic nature of the FMAR. The experimental approach and results provide new insight in the interplay between photonic, spintronic, and charge effects in FM microstructures.Comment: 4 pages, 4 figure

Millimeter wave satellite concepts. Volume 1: Executive summary

The objectives of the program were: (1) development of methodology based on the technical requirements of potential services that might be assigned to millimeter wave bands for identifying the viable and appropriate technologies for future NASA millimeter research and development programs, and (2) testing of this methodology with user applications and services. The scope of the program included the entire communications network, both ground and space subsystems. The reports include: (1) cost, weight, and performance models for the subsystems, (2) conceptual design for point-to-point and broadcast communications satellites, (3) analytic relationships between subsystem parameters and an overall link performance, (4) baseline conceptual systems, (5) sensitivity studies, (6) model adjustment analyses, (7) identification of critical technologies and their risks, (8) brief R&D program scenarios for the technologies judged to be moderate or extensive risks