70 research outputs found
Evaluation of the ALMA Prototype Antennas
The ALMA North American and European prototype antennas have been evaluated
by a variety of measurement systems to quantify the major performance
specifications. Nearfield holography was used to set the reflector surfaces to
17 microns RMS. Pointing and fast switching performance was determined with an
optical telescope and by millimeter wavelength radiometry, yielding 2 arcsec
absolute and 0.6 arcsec offset pointing accuracies. Path length stability was
measured to be less than or approximately equal to 20 microns over 10 minute
time periods using optical measurement devices. Dynamical performance was
studied with a set of accelerometers, providing data on wind induced tracking
errors and structural deformation. Considering all measurements made during
this evaluation, both prototype antennas meet the major ALMA antenna
performance specifications.Comment: 83 pages, 36 figures, AASTex format, to appear in PASP September 2006
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The re-professionalization of the police in England and Wales
In this article contemporary police claims to professional status are analysed and related to a new structure of police regulation in England and Wales. It is argued that the notion of the police as a profession is not new and, unlike police and academic commentary, analysis of this subject, should draw on sociological understandings of professions. The wider policy context within which claims to professionalisation are made is also considered. It is argued that a new, loosely-coupled system of regulation has been developed in England and Wales. Policing’s professional body, the College of Policing, is central to this regulatory framework that has placed government at a distance from constabularies and police representative associations. Finally, some of the consequences of the hybrid system are considered and benefits of the framework of analysis proposed are discussed
Towards an organizational folklore of policing: the storied nature of policing and the police use of storytelling.
For police officers, much of the working day consists of telling stories about everyday policing and events. Although the study of narrative and storytelling in organizational contexts is an expanding area of research, the same cannot be said of the study of narrative and storytelling in a police context, which remains an under-researched, although not unexplored, subject of study. Using the work of management-narrative theorists such as David Boje and Yiannis Gabriel as a starting point, this article considers policing organizations and agencies as storytelling organizations. This is achieved through a literature review of the 'storied' nature of policing and the police use of storytelling in an organizational context. Thus, this reflective article contributes to the developing literature in the field by reviewing and mapping the literature, highlighting potential areas for future research
The endocrine tumor summit 2008: appraising therapeutic approaches for acromegaly and carcinoid syndrome
The Endocrine Tumor Summit convened in December 2008 to address 6 statements prepared by panel members that reflect important questions in the treatment of acromegaly and carcinoid syndrome. Data pertinent to each of the statements were identified through review of pertinent literature by one of the 9-member panel, enabling a critical evaluation of the statements and the evidence supporting or refuting them. Three statements addressed the validity of serum growth hormone (GH) and insulin-like growth factor-I (IGF-I) concentrations as indicators or predictors of disease in acromegaly. Statements regarding the effects of preoperative somatostatin analog use on pituitary surgical outcomes, their effects on hormone and symptom control in carcinoid syndrome, and the efficacy of extended dosing intervals were reviewed. Panel opinions, based on the level of available scientific evidence, were polled. Finally, their views were compared with those of surveyed community-based endocrinologists and neurosurgeons
Ancient DNA Resolves Identity and Phylogeny of New Zealand's Extinct and Living Quail (Coturnix sp.)
BACKGROUND: The New Zealand quail, Coturnix novaezealandiae, was widespread throughout New Zealand until its rapid extinction in the 1870's. To date, confusion continues to exist concerning the identity of C. novaezealandiae and its phylogenetic relationship to Coturnix species in neighbouring Australia, two of which, C. ypsilophora and C. pectoralis, were introduced into New Zealand as game birds. The Australian brown quail, C. ypsilophora, was the only species thought to establish with current populations distributed mainly in the northern part of the North Island of New Zealand. Owing to the similarities between C. ypsilophora, C. pectoralis, and C. novaezealandiae, uncertainty has arisen over whether the New Zealand quail is indeed extinct, with suggestions that remnant populations of C. novaezealandiae may have survived on offshore islands. METHODOLOGY/PRINCIPAL FINDINGS: Using fresh and historical samples of Coturnix sp. from New Zealand and Australia, DNA analysis of selected mitochondrial regions was carried out to determine phylogenetic relationships and species status. Results show that Coturnix sp. specimens from the New Zealand mainland and offshore island Tiritiri Matangi are not the New Zealand quail but are genetically identical to C. ypsilophora from Australia and can be classified as the same species. Furthermore, cytochrome b and COI barcoding analysis of the New Zealand quail and Australia's C. pectoralis, often confused in museum collections, show that they are indeed separate species that diverged approximately 5 million years ago (mya). Gross morphological analysis of these birds suggests a parallel loss of sustained flight with very little change in other phenotypic characters such as plumage or skeletal structure. CONCLUSION/SIGNIFICANCE: Ancient DNA has proved invaluable for the detailed analysis and identification of extinct and morphologically cryptic taxa such as that of quail and can provide insights into the timing of evolutionary changes that influence morphology
Penetration of the Stigma and Style Elicits a Novel Transcriptome in Pollen Tubes, Pointing to Genes Critical for Growth in a Pistil
Pollen tubes extend through pistil tissues and are guided to ovules where they release sperm for fertilization. Although pollen tubes can germinate and elongate in a synthetic medium, their trajectory is random and their growth rates are slower compared to growth in pistil tissues. Furthermore, interaction with the pistil renders pollen tubes competent to respond to guidance cues secreted by specialized cells within the ovule. The molecular basis for this potentiation of the pollen tube by the pistil remains uncharacterized. Using microarray analysis in Arabidopsis, we show that pollen tubes that have grown through stigma and style tissues of a pistil have a distinct gene expression profile and express a substantially larger fraction of the Arabidopsis genome than pollen grains or pollen tubes grown in vitro. Genes involved in signal transduction, transcription, and pollen tube growth are overrepresented in the subset of the Arabidopsis genome that is enriched in pistil-interacted pollen tubes, suggesting the possibility of a regulatory network that orchestrates gene expression as pollen tubes migrate through the pistil. Reverse genetic analysis of genes induced during pollen tube growth identified seven that had not previously been implicated in pollen tube growth. Two genes are required for pollen tube navigation through the pistil, and five genes are required for optimal pollen tube elongation in vitro. Our studies form the foundation for functional genomic analysis of the interactions between the pollen tube and the pistil, which is an excellent system for elucidation of novel modes of cell–cell interaction
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