2,571 research outputs found

    GGD 27: X-rays from a Massive Protostar with an Outflow

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    We report the discovery of a cluster of Class I protostars in GGD 27. One of these protostars is the previously known, centrally located, GGD 27-ILL, which powers a massive bipolar outflow. We show that GGD 27-ILL, which is known to be the bright infrared (IR) source, IRAS 18162-2048, and a compact radio continuum source, is also the newly discovered hard X-ray source, GGD 27-X. The observations were made with the ACIS instrument on the Chandra X-ray Observatory. The X-rays from GGD 27-X are variable when compared with 4 years earlier, with an unabsorbed 2-10 keV X-ray luminosity in this observation of 1.5-12 × 10^31 erg s^–1 and a plasma temperature of ≥ 10^7 K. The X-rays are probably associated with the underlying B0 star (rather than outflowing material), providing a rare glimpse in hard X-rays of an optically obscured massive protostar with an outflow. The X-ray luminosity and spectrum appear to be consistent with stars of its type in other star formation regions. Several other variable X-ray sources are also detected in the IR cluster that contains GGD 27-X. We also discuss another nearby cluster. In each of the clusters there is an object that is X-ray hard, highly absorbed at low energies, in a blank optical/IR/radio field, and variable in X-ray intensity by a factor of ≥ 10 on a timescale of 4 years. These latter objects may arise from more recent episodes of star formation or may be "hidden" Class III sources

    Orientation-sensitivity to facial features explains the Thatcher illusion

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    The Thatcher illusion provides a compelling example of the perceptual cost of face inversion. The Thatcher illusion is often thought to result from a disruption to the processing of spatial relations between face features. Here, we show the limitations of this account and instead demonstrate that the effect of inversion in the Thatcher illusion is better explained by a disruption to the processing of purely local facial features. Using a matching task, we found that participants were able to discriminate normal and Thatcherized versions of the same face when they were presented in an upright orientation, but not when the images were inverted. Next, we showed that the effect of inversion was also apparent when only the eye region or only the mouth region was visible. These results demonstrate that a key component of the Thatcher illusion is to be found in orientation-specific encoding of the expressive features (eyes and mouth) of the face

    Pancreatic cancer patient survival correlates with DNA methylation of pancreas development genes.

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    DNA methylation is an epigenetic mark associated with regulation of transcription and genome structure. These markers have been investigated in a variety of cancer settings for their utility in differentiating normal tissue from tumor tissue. Here, we examine the direct correlation between DNA methylation and patient survival. We find that changes in the DNA methylation of key pancreatic developmental genes are strongly associated with patient survival

    Software engineering 2004 : A jewel in the ACM/IEEE-CS curricula effort

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    We outline the ACM/IEEE-CS sponsored Computing Curricula project, and then discuss the context and development of its Software Engineering Volume (SE2004).. We then discuss evaluation of the volume, internationalization, the relationship with other disciplines, and the importance of the document’s future evolution.Education for the 21 st century - impact of ICT and Digital Resources ConferenceRed de Universidades con Carreras en Informática (RedUNCI

    Anisotropic Gauss-Hermite Beam Model Applied to through-Transmission Inspections of Delaminations in Composite Plates

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    Manufactured parts containing composite materials can present challenging ultrasonic inspection problems. The inherent anisotropy of such materials acts to distort propagating ultrasonic beams, leading in turn to an associated distortion of defect images. Such distortions complicate the task of estimating the physical dimensions of a defect from its ultrasonic image. In the present work we demonstrate how these difficulties can be overcome by appropriately modelling the ultrasonic inspection process, and using the model to analyze defect images. To illustrate the approach, we consider a normal incidence through-transmission inspection of a flat uniaxial composite plate with an internal delamination. We begin by reviewing our model of the inspection process which incorporates the Gauss-Hermite model for beam propagation in anisotropic materials. The inspection model requires as inputs certain parameters which characterize the transducers, and others which characterize the composite material. We demonstrate how these parameters can be obtained from simple beam-mapping experiments. We then present experimental C-scan images of a seeded circular delamination in a composite plate, and compare these to images predicted by the model. Finally, we demonstrate how the model can be used to accurately size a delamination from its ultrasonic image

    Decreasing the number of arthroscopies in knee osteoarthritis – a service evaluation of a de-implementation strategy

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    Background: The Personalised Knee Improvement Programme (P-KIP) was developed based on previously published work, with the hypothesis that surgeons would refer patients to a well-structured conservative management intervention instead of for arthroscopy (de-implementation of arthroscopy by substitution with P-KIP). This meets NICE guidelines and international recommendations but such programmes are not widely used in the UK. Our aim was to determine whether P-KIP would reduce the number of arthroscopies performed for knee osteoarthritis. Methods: P-KIP is a conservative care pathway including a group education session followed by individually tailored one-to-one dietician and physiotherapy sessions. Virtual clinic follow-up is conducted three to 6 months after completion of the programme. The service began in July 2015. The number of arthroscopies saved, measured from hospital level coding data, is the primary outcome measure. Interrupted time series analysis of coding data was conducted. As a quality assurance process, patient reported outcome measures (Oxford Knee Score; Euroqol 5D) were collected at baseline and at follow up. Results: Time series analysis demonstrates that the programme saved 15.4 arthroscopies a month (95% confidence interval 9–21; p < 0.001), equating to 184 arthroscopies a year in a single hospital. The PROMs data demonstrated improvements in patient reported outcome scores consistent with previous published reports of conservative interventions in similar patient populations. Conclusions: Results suggest that P-KIP reduces the number of arthroscopies performed, and patients who took part in P-KIP had an improvement in their knee and general health outcomes. P-KIP has the potential to deliver efficiency savings and relive pressure on operative lists, however replication in other sites is required

    A New Perspective on Coastally Trapped Disturbances Using Data from the Satellite Era

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    The ability of global climate models to simulate accurately marine stratiform clouds continues to challenge the atmospheric science community. These cloud types, which account for a large uncertainty in Earth’s radiation budget, are generally difficult to characterize due to their shallowness and spatial inhomogeneity. Previous work investigating marine boundary layer (MBL) clouds off the California coast has focused on clouds that form under the typical northerly flow regime during the boreal warm season. From about June through September, however, these northerly winds may reverse and become southerly as part of a coastally trapped disturbance (CTD). As the flow surges northward, it is accompanied by a broad cloud deck. Because these events are difficult to forecast, in situ observations of CTDs are few and far between, and little is known about their cloud physical properties. A climatological perspective of 23 CTD events—spanning the years from 2004 to 2016—is presented using several data products, including model reanalyses, buoys, and satellites. For the first time, satellite retrievals suggest that CTD cloud decks may play a unique role in the radiation budget due to a combination of aerosol sources that enhance cloud droplet number concentration and reduce cloud droplet effective radius. This particular type of cloud regime should therefore be treated differently than that which is more commonly found in the summertime months over the northeast Pacific Ocean. The potential influence of a coherent wind stress cycle on sea surface temperatures and sea salt aerosol is also explored

    Cereal and Pulse Crops with Improved Resistance to Pratylenchus thornei Are Needed to Maximize Wheat Production and Expand Crop Sequence Options

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    n the subtropical grain region of eastern Australia, two experiments were conducted, one initially with 2490 P. thornei/kg soil, the other with 8150 P. thornei/kg soil at 0–0.9 m soil depth. We determined the effect of P. thornei, residual from a weed-free fallow and pre-cropping with several cultivars each of barley (Hordeum vulgare), faba bean (Vicia faba), chickpea (Cicer arietinum), and wheat (Triticum aestivum) (Phase 1), on the growth of wheat cultivars with intolerance or tolerance to P. thornei (Phase 2). Pratylenchus thornei substantially increased after growing all cultivars of the Phase 1 faba bean, barley, and most cultivars of chickpea and wheat, and decreased after two moderately resistant wheat cultivars and the fallow treatment. The biomass of the Phase 2 tolerant cultivar ranged from 5070 to 6780 kg/ha and the intolerant cultivar 1020 to 4740 kg/ha. There was a negative linear relationship between P. thornei population densities and biomass of the Phase 2 intolerant cultivar but not of the tolerant cultivar. Growers are at risk of financial loss because they are restricted in their choice of crops to reduce damaging population densities of P. thornei. The development of resistant and tolerant crop genotypes can maximize production in P. thornei-affected farming systems

    Towards a best practice for the use of active non-contact surface scanning to record human skeletal remains from archaeological contexts

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    Active surface scanners emit light or a laser stripe to record the exterior surface of an object or landscape, providing results in three dimensions. The use of active surface scanners to record anthropological and archaeological contexts has increased within the last few years, creating a number of sub-contexts within these disciplines, and allowing a further development of certain applications, such as quantitative analysis, the use of replicas in education and museums, and the creation of digital databases archived in institutions. However with guidance, this paper aims to assess the advantages and disadvantages of active surface scanning and the potential for research with regards to the recording and analysis of human skeletal remains. The key advantages and uses identified include: quantitative digitisation, geometric morphometric studies, conservation, preservation, documentation, and reconstruction. However, surface scanning also has some limitations, including: cost, technological expertise, the need for a power source, computing requirements, and data size. Overall, the application of active surface scanning technology to archaeological skeletal remains will provide a vital digital archive that will serve to preserve the integrity of this fragile and finite resource for future generations. This is particularly important within the current developer-funded environment in which many skeletal collections, including those yielding unique or unusual pathological or morphological features, are re-buried, with only very limited time for analysis
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