5,420 research outputs found

    Multi-wavelength Radio Continuum Emission Studies of Dust-free Red Giants

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    Multi-wavelength centimeter continuum observations of non-dusty, non-pulsating K spectral-type red giants directly sample their chromospheres and wind acceleration zones. Such stars are feeble emitters at these wavelengths however, and previous observations have provided only a small number of modest S/N measurements slowly accumulated over three decades. We present multi-wavelength Karl G. Jansky Very Large Array thermal continuum observations of the wind acceleration zones of two dust-free red giants, Arcturus (Alpha Boo: K2 III) and Aldebaran (Alpha Tau: K5 III). Importantly, most of our observations of each star were carried out over just a few days, so that we obtained a snapshot of the different stellar atmospheric layers sampled at different wavelengths, independent of any long-term variability. We report the first detections at several wavelengths for each star including a detection at 10 cm (3.0 GHz: S band) for both stars and a 20 cm (1.5 GHz: L band) detection for Alpha Boo. This is the first time single luminosity class III red giants have been detected at these continuum wavelengths. Our long-wavelength data sample the outer layers of Alpha Boo's atmosphere where its wind velocity is approaching its terminal value and the ionization balance is becoming frozen-in. For Alpha Tau, however, our long-wavelength data are still sampling its inner atmosphere, where the wind is still accelerating probably due to its lower mass-loss rate. We compare our data with published semi-empirical models based on ultraviolet data, and the marked deviations highlight the need for new atmospheric models to be developed. Spectral indices are used to discuss the possible properties of the stellar atmospheres, and we find evidence for a rapidly cooling wind in the case of Alpha Boo. Finally, we develop a simple analytical wind model for Alpha Boo based on our new long-wavelength flux measurements

    Intellectual Property\u27s First Sale Doctrine and the Policy Against Restraints on Alienation

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    The first sale doctrine decouples intellectual property and physical property. Suppose, at an auction at Sothebyā€™s, someone bought a contemporary painting by Chuck Close. The buyer now owns the physical painting, but the copyright to the painting remains with the owner of the copyrightā€”the painter Chuck Close or whomever Close may have transferred the copyright to. Absent the first sale doctrine, if the buyer either sold the painting or displayed it to the public, the buyer would potentially infringe the copyright in the painting. The copyright owner has the exclusive right to display copies (including the original, the first copy) of the painting to the public and to distribute copies to the public. However, the first sale doctrine provides that the owner of an authorized copy may display or distribute that particular copy without infringing. The distribution right and display right no longer apply; these rights are ā€œexhausted.ā€ Permission from the copyright owner is not required to resell copyrighted works or to display them. First sale permits a broad swath of activity. Used bookstores, libraries, swap fests, eBay, students reselling casebooks, and many more may rely on first sale to protect their distribution of copyrighted works. Museums, galleries, archives, bookstores, and more can likewise display their copies of copyrighted works without infringing under first sale. First sale (more commonly called ā€œexhaustionā€ in patent law) also applies to patented products. Someone who buys a patented product (such as a pharmaceutical, computing device, or printer cartridge) can use or resell that product without infringing the patent, even though the patent owner has the rights to exclude others from using or selling the invention. First sale enables markets for resale or lease of patent products, from printer cartridges to airplanes. First sale has its limits. In copyright, it applies only to the rights to distribute and to display the work. The copyright owner also has the exclusive right to make copies, to adapt the work, and to perform the work publicly, which are not subject to first sale. The painting buyer would potentially infringe if the buyer made a copy of the painting or adapted it into another artwork, but the buyer could not infringe the performance right, because one cannot perform a painting. The owner of a copy of a musical work may infringe if she performs it in public, which is why bars need licenses to play copyrighted music, even using copies they have purchased. The owner of a copy of a movie may infringe if she adapted the movie, such as making a sequelā€”or even dubbing the movie in another language. In patent, first sale likewise would not authorize the purchaser of a product to make additional copies. Similarly, first sale in patent would authorize the buyer of a patented item to use it or resell it, but not to make another one. First sale is long-established, by statute in copyright and by judicial interpretation in patent. The underlying policy of first sale, however, has been unsettled. First sale can be seen to rest on either of two rationales. The first is a contract-based, gap-filler approach. If someone sells a painting, one would expect an implicit agreement that the buyer could display the painting or resell it, as both actions are customary with artworks. To simplify transactions, the rights to resell and display are automatically included in the transaction. The other justification is the policy against restraints on alienation, borrowed from the law of real property. Someone who sells property may not impose unreasonable restraints on the buyerā€™s ability to resell the property. As transplanted to intellectual property law, once a party voluntarily parts with a copy, she should no longer be able to control what the buyer does with it. Hence, her rights are ā€œexhaustedā€ in that particular copy. The underlying rationale is important for determining the extent of the first sale doctrine. If first sale is a gap-filler, then the parties could contract around it, agreeing that the property sold would not be subject to first-sale rights. If first sale is a policy-based bar against unreasonable restraints on alienation, then first sale is mandatoryā€”it is not subject to the agreement of the parties but rather is the opposite: a limit on the enforceability of their agreement. Both strains can be seen in the case law. Two recent Supreme Court cases, however, decisively rested first sale on the restraints-against- alienation rationale, expressly rejecting the proposition that parties can contract around first sale. This Article explores the implications of those cases for the boundaries of first sale, focusing on two issues. First, Californiaā€™s resale royalty law required that artists receive 5% of the proceeds on resale of their work. The Ninth Circuit held that the California statute was preempted by the first sale doctrine of federal copyright law. We conclude that, if first sale serves to prevent unreasonable restraints on alienation, such resale royalty statutes should be valid. Rather than an unreasonable restraint on alienation, they permit resale, imposing a modest burden for a purpose entirely consonant with copyright law: rewarding authors. Second, software sellers have long avoided first sale by characterizing software sales as mere licenses, while formally retaining ownership of the software after delivery to the buyer. Courts have enforced transactions according to the partiesā€™ contract. We conclude, however, that such transactions, which are intended to prevent resale of software, should be characterized as sales in substance, triggering first-sale rights to resell the software, overriding the contractual restraint on alienation

    Measuring the speed of the conscious components of recognition memory: Remembering is faster than knowing.

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    Three experiments investigated response times (RTs) for remember and know responses in recognition memory. RTs to remember responses were faster than RTs to know responses, regardless of whether the rememberā€“know decision was preceded by an old/new decision (two-step procedure) or was made without a preceding old/new decision (one-step procedure). The finding of faster RTs for R responses was also found when rememberā€“know decisions were made retrospectively. These findings are inconsistent with dual-process models of recognition memory, which predict that recollection is slower and more effortful than familiarity. Word frequency did not influence RTs, but remember responses were faster for words than for nonwords. We argue that the difference in RTs to remember and know responses reflects the time taken to make old/new decisions on the basis of the type of information activated at test

    A Descriptive Study of Nosocomial Infections in an Adult Intensive Care Unit in Fiji: 2011-12

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    Copyright Ā© 2014 Keshni Naidu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Nosocomial infections in an intensive care unit (ICU) are common and associated with a high mortality but there are no published data from the Oceania region. A retrospective study in Fijiā€™s largest ICU (2011-12) reported that 114 of a total 663 adult ICU admissions had bacteriological culture-confirmed nosocomial infection. The commonest sites of infection were respiratory and bloodstream. Gram negative bacteria were the commonest pathogens isolated, especially Klebsiella pneumoniae (extended-spectru

    Genomic analysis of the role of transcription factor C/EBPĪ“ in the regulation of cell behaviour on nanometric grooves

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    C/EBPĪ“ is a tumour suppressor transcription factor that induces gene expression involved in suppressing cell migration. Here we investigate whether C/EBPĪ“-dependent gene expression also affects cell responses to nanometric topology. We found that ablation of the C/EBPĪ“ gene in mouse embryonal fibroblasts (MEFs) decreased cell size, adhesion and cytoskeleton spreading on 240 nm and 540 nm nanometric grooves. ChIP-SEQ and cDNA microarray analyses demonstrated that many binding sites for C/EBPĪ“, and the closely related C/EBPĪ², exist throughout the mouse genome and control the upregulation or downregulation of many adjacent genes. We also identified a group of C/EBPĪ“-dependent, trans-regulated genes, whose promoters contained no C/EBPĪ“ binding sites and yet their activity was regulated in a C/EBPĪ“-dependent manner. These genes include signalling molecules (e.g. SOCS3), cytoskeletal components (Tubb2, Krt16 and Krt20) and cytoskeletal regulators (ArhGEF33 and Rnd3) and are possibly regulated by cis-regulated diffusible mediators, such as IL6. Of particular note, SOCS3 was shown to be absolutely required for efficient cell spreading and contact guidance on 240 nm and 540 nm nanometric grooves. C/EBPĪ“ is therefore involved in the complex regulation of multiple genes, including cytoskeletal components and signalling mediators, which influence the nature of cell interactions with nanometric topology

    Differential trafficking of AMPA receptors following activation of NMDA receptors and mGluRs

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    The removal of AMPA receptors from synapses is a major component of long-term depression (LTD). How this occurs, however, is still only partially understood. To investigate the trafficking of AMPA receptors in real-time we previously tagged the GluA2 subunit of AMPA receptors with ecliptic pHluorin and studied the effects of NMDA receptor activation. In the present study we have compared the effect of NMDA receptor and group I mGluR activation, using GluA2 tagged with super ecliptic pHluorin (SEP-GluA2) expressed in cultured hippocampal neurons. Surprisingly, agonists of the two receptors, which are both able to induce chemical forms of LTD, had clearly distinct effects on AMPA receptor trafficking. In agreement with our previous work we found that transient NMDA receptor activation results in an initial decrease in surface GluA2 from extrasynaptic sites followed by a delayed reduction in GluA2 from puncta (putative synapses). In contrast, transient activation of group I mGluRs, using DHPG, led to a pronounced but more delayed decrease in GluA2 from the dendritic shafts. Surprisingly, there was no average change in the fluorescence of the puncta. Examination of fluorescence at individual puncta, however, indicated that alterations did take place, with some puncta showing an increase and others a decrease in fluorescence. The effects of DHPG were, like DHPG-induced LTD, prevented by treatment with a protein tyrosine phosphatase (PTP) inhibitor. The electrophysiological correlate of the effects of DHPG in the SEP-GluA2 infected cultures was a reduction in mEPSC frequency with no change in amplitude. The implications of these findings for the initial mechanisms of expression of both NMDA receptor- and mGluR-induced LTD are discussed

    Measuring the difference between actual and reported food intakes in the context of energy balance under laboratory conditions

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    Acknowledgements The present study was funded by the Food Standards Agency, UK. The Food Standards Agency had no role in the design, analysis or writing of this article. The authorsā€™ responsibilities were as follows: R. J. S., L. M. Oā€™R. and G. W. H. designed the research; L. M. Oā€™R. and Z. F. conducted the research and analysed the data; G. W. H. performed the statistical analyses; P. R. carried out the DLW analysis; R. J. S. had primary responsibility for the final content; R. J. S., L. M. Oā€™R., Z. F., S. W. and M. B. E. L. wrote the paper.Peer reviewedPublisher PD

    Adaptive foveated single-pixel imaging with dynamic super-sampling

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    As an alternative to conventional multi-pixel cameras, single-pixel cameras enable images to be recorded using a single detector that measures the correlations between the scene and a set of patterns. However, to fully sample a scene in this way requires at least the same number of correlation measurements as there are pixels in the reconstructed image. Therefore single-pixel imaging systems typically exhibit low frame-rates. To mitigate this, a range of compressive sensing techniques have been developed which rely on a priori knowledge of the scene to reconstruct images from an under-sampled set of measurements. In this work we take a different approach and adopt a strategy inspired by the foveated vision systems found in the animal kingdom - a framework that exploits the spatio-temporal redundancy present in many dynamic scenes. In our single-pixel imaging system a high-resolution foveal region follows motion within the scene, but unlike a simple zoom, every frame delivers new spatial information from across the entire field-of-view. Using this approach we demonstrate a four-fold reduction in the time taken to record the detail of rapidly evolving features, whilst simultaneously accumulating detail of more slowly evolving regions over several consecutive frames. This tiered super-sampling technique enables the reconstruction of video streams in which both the resolution and the effective exposure-time spatially vary and adapt dynamically in response to the evolution of the scene. The methods described here can complement existing compressive sensing approaches and may be applied to enhance a variety of computational imagers that rely on sequential correlation measurements.Comment: 13 pages, 5 figure
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