Polarized Neutron Laue Diffraction on a Crystal Containing Dynamically Polarized Proton Spins

We report on a polarized-neutron Laue diffraction experiment on a single crystal of neodynium doped lanthanum magnesium nitrate hydrate containing polarized proton spins. By using dynamic nuclear polarization to polarize the proton spins, we demonstrate that the intensities of the Bragg peaks can be enhanced or diminished significantly, whilst the incoherent background, due to proton spin disorder, is reduced. It follows that the method offers unique possibilities to tune continuously the contrast of the Bragg reflections and thereby represents a new tool for increasing substantially the signal-to-noise ratio in neutron diffraction patterns of hydrogenous matter.Comment: 5 pages, 3 figure

Finding Space for Agency in Permanent Exclusion from School

This article aims to examine the experiences of pupils and professionals who are affected by permanent exclusion (what used to be called being expelled) from school. An ethnographic study conducted during the author’s employment as a Pupil Support Officer within secondary schools and the children’s services department of an urban local authority in England explores the idea that professionals may be forced to make inequitable decisions about including or excluding pupils in the face of powerful competition between the politically unchallengeable concepts of tolerance, inclusivity, attainment, and choice. The article argues that the tensions of multi-agency working are focused within what will be described as the contested space of the young person’s ‘extended body’. However, whilst the contested nature of this space renders it vulnerable to negative description and to the biased judgements of authoritarian power, it also offers itself as a space for emancipatory self description by the young person and for the expression of agency on the part of those professionals working for social justice

Relative sound localisation abilities in human listeners

Spatial acuity varies with sound-source azimuth, signal-to-noise ratio, and the spectral characteristics of the sound source. Here, the spatial localisation abilities of listeners were assessed using a relative localisation task. This task tested localisation ability at fixed angular separations throughout space using a two-alternative forced-choice design across a variety of listening conditions. Subjects were required to determine whether a target sound originated to the left or right of a preceding reference in the presence of a multi-source noise background. Experiment 1 demonstrated that subjects' ability to determine the relative location of two sources declined with less favourable signal-to-noise ratios and at peripheral locations. Experiment 2 assessed performance with both broadband and spectrally restricted stimuli designed to limit localisation cues to predominantly interaural level differences or interaural timing differences (ITDs). Predictions generated from topographic, modified topographic, and two-channel models of sound localisation suggest that for low-pass stimuli, where ITD cues were dominant, the two-channel model provides an adequate description of the experimental data, whereas for broadband and high frequency bandpass stimuli none of the models was able to fully account for performance. Experiment 3 demonstrated that relative localisation performance was uninfluenced by shifts in gaze direction

The Accretion History of AGN: A Newly Defined Population of Cold Quasars

Quasars are the most luminous of active galactic nuclei (AGN), and are perhaps responsible for quenching star formation in their hosts. The Stripe 82X catalog covers 31.3 deg$^2$ of the Stripe 82 field, of which the 15.6 deg$^2$ covered with XMM-Newton is also covered by Herschel/SPIRE. We have 2500 X-ray detected sources with multi-wavelength counterparts, and 30% of these are unobscured quasars, with $L_X > 10^{44}\,$erg/s and $M_B < -23$. We define a new population of quasars which are unobscured, have X-ray luminosities in excess of $10^{44}\,$erg/s, have broad emission lines, and yet are also bright in the far-infrared, with a 250$\mu$m flux density of $S_{\rm 250}>30$mJy. We refer to these Herschel-detected, unobscured quasars as "Cold Quasars". A mere 4% (21) of the X-ray- and optically-selected unobscured quasars in Stripe 82X are detected at 250$\mu$m. These Cold Quasars lie at $z\sim1-3$, have $L_{\rm IR}>10^{12}\,L_\odot$, and have star formation rates of $\sim200-1400\,M_\odot$/yr. Cold Quasars are bluer in the mid-IR than the full quasar population, and 72% of our Cold Quasars have WISE W3 $<$ 11.5 [Vega], while only 19% of the full quasar sample meets this criteria. Crucially, Cold Quasars have on average $\sim9\times$ as much star formation as the main sequence of star forming galaxies at similar redshifts. Although dust-rich, unobscured quasars have occasionally been noted in the literature before, we argue that they should be considered as a separate class of quasars due to their high star formation rates. This phase is likely short-lived, as the central engine and immense star formation consume the gas reservoir. Cold Quasars are type-1 blue quasars that reside in starburst galaxies.Comment: Accepted for publication in Ap

THE ROLE OF INTERDEPENDENCE IN THE MICRO-FOUNDATIONS OF ORGANIZATION DESIGN: TASK, GOAL, AND KNOWLEDGE INTERDEPENDENCE

Interdependence is a core concept in organization design, yet one that has remained consistently understudied. Current notions of interdependence remain rooted in seminal works, produced at a time when managers’ near-perfect understanding of the task at hand drove the organization design process. In this context, task interdependence was rightly assumed to be exogenously determined by characteristics of the work and the technology. We no longer live in that world, yet our view of interdependence has remained exceedingly task-centric and our treatment of interdependence overly deterministic. As organizations face increasingly unpredictable workstreams and workers co-design the organization alongside managers, our field requires a more comprehensive toolbox that incorporates aspects of agent-based interdependence. In this paper, we synthesize research in organization design, organizational behavior, and other related literatures to examine three types of interdependence that characterize organizations’ workflows: task, goal, and knowledge interdependence. We offer clear definitions for each construct, analyze how each arises endogenously in the design process, explore their interrelations, and pose questions to guide future research

Novel Qualitative Structure-Activity Relationships for the Antinociceptive Actions of H 2 Antagonists, H 3 Antagonists and Derivatives 1

ABSTRACT Recent studies have shown that cimetidine, burimamide and improgan (also known as SKF92374, a cimetidine congener lacking H 2 antagonist activity) induce antinociception after intracerebroventricular administration in rodents. Because these substances closely resemble the structure of histamine (a known mediator of some endogenous analgesic responses), yet no role for known histamine receptors has been found in the analgesic actions of these agents, the structure-activity relationships for the antinociceptive effects of 21 compounds chemically related to H 2 and H 3 antagonists were investigated in this study. Antinociceptive activity was assessed on the hot-plate and tail-flick tests after intracerebroventricular administration in rats. Eleven compounds induced time-dependent (10-min peak) and dose-dependent antinociceptive activity with no observable behavioral impairment. ED 50 values, estimated by nonlinear regression, were highly correlated across nociceptive assays (r 2 ϭ 0.98, n ϭ 11). Antinociceptive potencies varied more than 6-fold (80 -464 nmol), but were not correlated with activity on H 1 , H 2 or H 3 receptors. Although highly potent H 3 antagonists such as thioperamide lacked antinociceptive activity, homologs of burimamide and thioperamide containing N-aromatic substituents retained H 3 antagonist activity and also showed potent, effective analgesia. A literature review of the pharmacology of these agents did not find a basis for their antinociceptive effects. Taken with previous findings, the present results suggest: 1) these compounds act on the brain to activate powerful analgesic responses that are independent of known histamine receptors, 2) the structure-activity profile of these agents is novel and 3) brain-penetrating derivatives of these compounds could be clinically useful analgesics

Epidemiology and molecular phylogeny of Babesia sp. in Little Penguins Eudyptula minor in Australia

Blood parasites are potential threats to the health of penguins and to their conservation and management. Little penguins Eudyptula minor are native to Australia and New Zealand, and are susceptible to piroplasmids (Babesia), hemosporidians (Haemoproteus, Leucocytozoon, Plasmodium) and kinetoplastids (Trypanosoma). We studied a total of 263 wild little penguins at 20 sites along the Australian southeastern coast, in addition to 16 captive-bred little penguins. Babesia sp. was identified in seven wild little penguins, with positive individuals recorded in New South Wales, Victoria and Tasmania. True prevalence was estimated between 3.4% and 4.5%. Only round forms of the parasite were observed, and gene sequencing confirmed the identity of the parasite and demonstrated it is closely related to Babesia poelea from boobies (Sula spp.) and B. uriae from murres (Uria aalge). None of the Babesia-positive penguins presented signs of disease, confirming earlier suggestions that chronic infections by these parasites are not substantially problematic to otherwise healthy little penguins. We searched also for kinetoplastids, and despite targeted sampling of little penguins near the location where Trypanosoma eudyptulae was originally reported, this parasite was not detected