4,768 research outputs found
On the photometric behaviour of the Pleiades K dwarf HII 1883
Photometric data from a variety of sources have been analysed to check if effects of differential rotation or evolutionary spin-down can be detected in HII 1883. Although the same light- curve form may be maintained for several years, shape changes and phase shifts do not allow sufficiently long time-bases for the required accuracy of period determination. One form of light-curve may have a tendency to recur with phase coherence. Using this observation allows determination of three potentially more accurate periods relative to the one previously established, but the choice of any revised value is subject to imprecise knowledge of the integer number of cycles over the time-base. The phase-locked tendency, if confirmed, requires some mechanism for spots to recur at a given longitude. A suggestion of the star being a magnetic oblique rotator is mooted but other observational and theoretical support would be required to promote this notion further. Evidence of small short-term changes occurring over just a few periods is explored. Comparison of the contemporaneous light- curve with the H α line emission RV variations reveals a phase difference of 90°, so making a connection that the disturbances producing the photometric signals have the same location as those generating at least some part of the H α emission. Finally a multi-spot model is presented to mimic the observed light-curves
High-resolution Near-Infrared Images and Models of the Circumstellar Disk in HH 30
We present Hubble Space Telescope (HST) Near-Infrared Camera and Multi-object
Spectrometer (NICMOS) observations of the reflection nebulosity associated with
the T Tauri star HH 30. The images show the scattered light pattern
characteristic of a highly inclined, optically thick disk with a prominent
dustlane whose width decreases with increasing wavelength. The reflected
nebulosity exhibits a lateral asymmetry in the upper lobe on the opposite side
to that reported in previously published Wide Field Planetary Camera 2 (WFPC2)
images. The radiation transfer model which most closely reproduces the data has
a flared accretion disk with dust grains larger than standard interstellar
medium grains by a factor of approximately 2.1. A single hotspot on the stellar
surface provides the necessary asymmetry to fit the images and is consistent
with previous modeling of the light curve and images. Photometric analysis
results in an estimated extinction of Av>~80; however, since the photometry
measures only scattered light rather than direct stellar flux, this a lower
limit. The radiative transfer models require an extinction of Av = 7,900.Comment: Accepted for publication in Ap.
CpG increases vaccine antigen-specific cell-mediated immunity when administered with hepatitis B vaccine in HIV infection
On the functional anatomy of the urge-for-action
Several common neuropsychiatric disorders (e.g., obsessive-compulsive disorder, Tourette syndrome (TS), autistic spectrum disorder) are associated with unpleasant bodily sensations that are perceived as an urge for action. Similarly, many of our everyday behaviors are also characterized by bodily sensations that we experience as urges for action. Where do these urges originate? In this paper, we consider the nature and the functional anatomy of âurges-for-action,â both in the context of everyday behaviors such as yawning, swallowing, and micturition, and in relation to clinical disorders in which the urge-for-action is considered pathological and substantially interferes with activities of daily living (e.g., TS). We review previous frameworks for thinking about behavioral urges and demonstrate that there is considerable overlap between the functional anatomy of urges associated with everyday behaviors such as swallowing, yawning, and micturition, and those urges associated with the generation of tics in TS. Specifically, we show that the limbic sensory and motor regionsâinsula and mid-cingulate cortexâare common to all of these behaviors, and we argue that this âmotivation-for-actionâ network should be considered distinct from an âintentional actionâ network, associated with regions of premotor and parietal cortex, which may be responsible for the perception of âwilled intentionâ during the execution of goal-directed actions
The EBLM Project I-Physical and orbital parameters, including spin-orbit angles, of two low-mass eclipsing binaries on opposite sides of the Brown Dwarf limit
This paper introduces a series of papers aiming to study the dozens of low
mass eclipsing binaries (EBLM), with F, G, K primaries, that have been
discovered in the course of the WASP survey. Our objects are mostly single-line
binaries whose eclipses have been detected by WASP and were initially followed
up as potential planetary transit candidates. These have bright primaries,
which facilitates spectroscopic observations during transit and allows the
study of the spin-orbit distribution of F, G, K+M eclipsing binaries through
the Rossiter-McLaughlin effect. Here we report on the spin-orbit angle of
WASP-30b, a transiting brown dwarf, and improve its orbital parameters. We also
present the mass, radius, spin-orbit angle and orbital parameters of a new
eclipsing binary, J1219-39b (1SWAPJ121921.03-395125.6, TYC 7760-484-1), which,
with a mass of 95 +/- 2 Mjup, is close to the limit between brown dwarfs and
stars. We find that both objects orbit in planes that appear aligned with their
primaries' equatorial planes. Neither primaries are synchronous. J1219-39b has
a modestly eccentric orbit and is in agreement with the theoretical
mass--radius relationship, whereas WASP-30b lies above it.Comment: 12 pages, 7 figures, data in appendices, submitted to A&A (taking in
account 1st referee report
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Phenotypic heterogeneity and genetic modification of P102L inherited prion disease in an international series
The largest kindred with inherited prion disease P102L, historically Gerstmann-StrÀussler-Scheinker syndrome, originates from central England, with émigrés now resident in various parts of the English-speaking world. We have collected data from 84 patients in the large UK kindred and numerous small unrelated pedigrees to investigate phenotypic heterogeneity and modifying factors. This collection represents by far the largest series of P102L patients so far reported. Microsatellite and genealogical analyses of eight separate European kindreds support multiple distinct mutational events at a cytosine-phosphate diester-guanidine dinucleotide mutation hot spot. All of the smaller P102L kindreds were linked to polymorphic human prion protein gene codon 129M and were not connected by genealogy or microsatellite haplotype background to the large kindred or each other. While many present with classical Gerstmann-StrÀussler-Scheinker syndrome, a slowly progressive cerebellar ataxia with later onset cognitive impairment, there is remarkable heterogeneity. A subset of patients present with prominent cognitive and psychiatric features and some have met diagnostic criteria for sporadic Creutzfeldt-Jakob disease. We show that polymorphic human prion protein gene codon 129 modifies age at onset: the earliest eight clinical onsets were all MM homozygotes and overall age at onset was 7 years earlier for MM compared with MV heterozygotes (P = 0.02). Unexpectedly, apolipoprotein E4 carriers have a delayed age of onset by 10 years (P = 0.02). We found a preponderance of female patients compared with males (54 females versus 30 males, P = 0.01), which probably relates to ascertainment bias. However, these modifiers had no impact on a semi-quantitative pathological phenotype in 10 autopsied patients. These data allow an appreciation of the range of clinical phenotype, modern imaging and molecular investigation and should inform genetic counselling of at-risk individuals, with the identification of two genetic modifiers
The United Kingdoms Eurosceptic political economy
This article explores how a political economy approach can explicate recent events in the United Kingdomâs relation to the European Union. The proposition is that neither critical nor comparative approaches do justice to the extent to which British elites have sought to differentiate the UK from the EU. The UK is here understood as a Eurosceptic political economy, constructed in opposition to European integration and, in particular, Economic and Monetary. The article explores how we have witnessed a hardening of this Eurosceptic political economy in the context of the Eurozone crisis. The most distinctive feature of which, as seen in the referendum campaign, is the extent to which the economic case for withdrawal has been established as part of the mainstream of British political debate
The revitalised Fonofale as a research paradigm: A perspective on Pacific sexuality and reproduction research
Research into Pacific peoplesâ sexuality and reproduction is often complex and conflicts with social tapu. Historically, Pacific sexuality and reproduction research had been approached using a deficits-based lens with minimal congruence of Pacific cultural values. We offer a revitalised Fonofale model (Pulotu-Endemann, 1995) as a research paradigm that centres tapu in all considerations and decisions surrounding the research. This revitalised model offers a strengths-based approach that can promote valuable collection of, and meaningful engagement with data. We offer a case study which utilised this research paradigm as an overarching strategy. Te TÄ«pani Project was a mixed methods investigation into eighty-two Pacific tertiary studentsâ understandings of sexuality and reproduction. Pacific research methods and methodologies, including the Kakala model and Talanoa method supported the integration of the paradigm into components of the study. We encourage researchers to utilise this strategy to fulfil their research obligations, as facilitators and guardians (mana tiaki) of the research environment. Pacific research methods, methodologies and epistemologies hold an important place in the field of sensitive Pacific well-being research by enabling cultural consideration and responsiveness
Memorial meshwork: the making of the commemorative space of the Hyde Park 7/7 memorial
How do memorials act to transmit memory through the organization of space? In this paper we contrast a âpreservationâ model of the endurance of encoded memory with a âmeshworkâ model which treats memory as emergent on the perdurance of the memorial site. Developing a theoretical framework from Tim Ingoldâs (2011; 2013) work, we describe how memorialization receives its spatial form through a collective work of braiding together multiple threads of activities and material flows. To illustrate, we examine the spatial and temporal organization of the Hyde Park 7/7 memorial from its initial designs, through to installation and contemporary use. We draw on interview data featuring various stakeholders in the 7/7 memorial project to analyse the relationship between memorial space and material relations. We develop an approach to organizational space as an unfinished meshwork that folds together wanted and unwanted memory, making the historical a matter of ongoing live concern but with the absence of a permanent guiding narrative
Intercultural ethics: questions of methods in language and intercultural communication
This paper explores how questions of ethics and questions of method are intertwined and unavoidable in any serious study of language and intercultural communication. It argues that the focus on difference and solution orientations to intercultural conflict has been a fundamental driver for theory, data collection and methods in the field. These approaches, the paper argues, have created a considerable consciousness raising industry, with methods, trainings and âcritical incidentsâ, which ultimately focus intellectual energy in areas which may be productive in terms of courses and publications but which have a problematic basis in their ethical terrain.
Dieser Artikel untersucht wie ethische und methodische Fragen nicht nur ineinander greifen, sondern in keiner ernstzunehmenden Studie ueber Sprache und interkulturelle Kommunikation ausgelassen werden duerfen. Es wird hier argumentiert, dass der Schwerpunkt auf Verschiedenheit und Problemorientierung im interkulturellen Konflikt einen wesentlichen Einfluss auf theoretische Entwicklungen, Datenerhebung und Methoden in diesem Bereich hatte. Dieser Artikel legt auch dar, wie diese Ansaetze eine betraechtliche âBewusstseinsbildungs â Branche' erzeugt haben, mit Methoden, Trainings, und âkritischen Interaktionssituationenâ, welche letztendlich allen intellektuellen Arbeitseifer auf Bereiche konzentriert hat, die zwar ertragreich sind in Bezug auf Kurse und Publikationen, jedoch eine problematische Grundlage im ethischen Bereich aufweisen
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