22,332 research outputs found

    Gamma-ray Novae: Rare or Nearby?

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    Classical Novae were revealed as a surprise source of gamma-rays in Fermi LAT observations. During the first 8 years since the LAT was launched, 6 novae in total have been detected to > 5 sigma in gamma-rays, in contrast to the 69 discovered optically in the same period. We attempt to resolve this discrepancy by assuming all novae are gamma-ray emitters, and assigning peak one-day fluxes based on a flat distribution of the known emitters to a simulated population. To determine optical parameters, the spatial distribution and magnitudes of bulge and disc novae in M31 are scaled to the Milky Way, which we approximate as a disc with a 20 kpc radius and elliptical bulge with semi major axis 3 kpc and axis ratios 2:1 in the xy plane. We approximate Galactic reddening using a double exponential disc with vertical and radial scale heights of r_d = 5 kpc and z_d = 0.2 kpc, and demonstrate that even such a rudimentary model can easily reproduce the observed fraction of gamma-ray novae, implying that these apparently rare sources are in fact nearby and not intrinsically rare. We conclude that classical novae with m_R < 12 and within ~8 kpc are likely to be discovered in gamma-rays using the Fermi LAT.Comment: Accepted by MNRAS, 10 pages, 7 figure

    Studying the effects of in-vehicle information systems on driver visual behaviour – implications for design

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    In-vehicle information systems (IVIS) are a common feature in modern vehicles. The interaction of drivers with IVIS when driving must be considered to minimise distraction whilst maintaining the benefits provided. This research investigates the glance behaviours of drivers, assessed from video data, when using two functions – a personal navigation device (study 1) and a green driving advisory device (study 2). The main focus was to establish the number of glances of 2 seconds or more to the IVIS and relate this to driver safety (as stipulated in new guidelines for use of IVIS proposed by NHTSA). In study 1, the percentage of eyes- off-road time for drivers was much greater in the experimental (with device) condition compared to the baseline condition (14.3% compared to 6.7%) but, whilst glances to the personal navigation device accounted for the majority of the increase, there were very few which exceeded 2 seconds. Drivers in study 2 spent on average 4.3% of their time looking at the system, at an average of 0.43 seconds per glance; no glances exceeded 2 seconds. The research showed that ordinary use of IVIS (excluding manual interaction) does not lead to driver visual distraction and therefore the impact on safety is minimal. The results of the study have important design implications for future in-vehicle information systems

    Wanderers

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    This book introduces the idea and experience of wandering, as reflected in cultural texts from popular songs to philosophical analysis, providing both a fascinating informal history and a necessary vantage point for understanding - in our era - the emergence of new wanderers.   Wanderers offers a fast-paced, wide-ranging, and compelling introduction to this significant and recurrent theme in literary history. David Brown Morris argues that wandering, as a primal and recurrent human experience, is basic to the understanding of certain literary texts. In turn, certain prominent literary and cultural texts (from Paradise Lost to pop songs, from Wordsworth to the blues, from the Wandering Jew to the film Nomadland) demonstrate how representations of wandering have changed across cultures, times, and genres. Wanderers provides an initial overview necessary to grasp the importance of wandering both as a perennial human experience and as a changing historical event, including contemporary forms such as homelessness and climate migration that make urgent claims upon us.   Wanderers takes you on a thoroughly enjoyable and informative stroll through a significant concept that will be of interest to those studying or researching literature, cultural studies, and philosophy

    Culture-specific programs for children and adults from minority groups who have asthma (Review)

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    Background People with asthma who come from minority groups have poorer asthma outcomes and more asthma related visits to Emergency Departments (ED). Various programmes are used to educate and empower people with asthma and these have previously been shown to improve certain asthma outcomes. Models of care for chronic diseases in minority groups usually include a focus of the cultural context of the individual and not just the symptoms of the disease. Therefore, questions about whether culturally specific asthma education programmes for people from minority groups are effective at improving asthma outcomes, are feasible and are cost-effective need to be answered. Objectives To determine whether culture-specific asthma programmes, in comparison to generic asthma education programmes or usual care, improve asthma related outcomes in children and adults with asthma who belong to minority groups. Search strategy We searched the Cochrane Register of Controlled Trials (CENTRAL), the Cochrane Airways Group Specialised Register, MEDLINE, EMBASE, review articles and reference lists of relevant articles. The latest search was performed in May 2008. Selection criteria All randomised controlled trials (RCTs) comparing the use of culture-specific asthma education programmes with generic asthma education programmes, or usual care, in adults or children from minority groups who suffer from asthma. Data collection and analysis Two review authors independently selected, extracted and assessed the data for inclusion. We contacted authors for further information if required. Main results Four studies were eligible for inclusion in the review. A total of 617 patients, aged from 5 to 59 years were included in the meta-analysis of data. Use of a culture-specific programme was superior to generic programmes or usual care, in improving asthma quality of life scores in adults, pooled WMD 0.25 (95% CI 0.09 to 0.41), asthma knowledge scores in children, WMD 3.30 (95% CI 1.07 to 5.53), and in a single study, reducing asthma exacerbation in children (risk ratio for hospitalisations 0.32, 95% CI 0.15, 0.70). Authors' conclusions Current limited data show that culture-specific programmes for adults and children from minority groups with asthma, are more effective than generic programmes in improving most (quality of life, asthma knowledge, asthma exacerbations, asthma control) but not all asthma outcomes. This evidence is limited by the small number of included studies and the lack of reported outcomes. Further trials are required to answer this question conclusively

    Advancing liquid atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry toward ultra-high-throughput analysis

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    Label-free high-throughput screening using mass spectrometry has the potential to provide rapid large-scale sample analysis at a speed of more than one sample per second. Such speed is important for compound library, assay and future clinical screening of millions of samples within a reasonable time frame. Herein, we present a liquid atmospheric pressure matrix-assisted laser desorption/ionization (AP-MALDI) setup for high-throughput large-scale sample analysis (>5 samples per second) for three substance classes (peptides, antibiotics and lipids). Liquid support matrices (LSM) were used for the analysis of standard substances as well as complex biological fluids (milk). Throughput and analytical robustness were mainly dependent on the complexity of the sample composition and the current limitations of the commercial hardware. However, the ultimate limits of liquid AP-MALDI in sample throughput can be conservatively estimated to be beyond 10-20 samples per second. This level of analytical speed is highly competitive compared with other label-free MS methods, including electrospray ionization and solid state MALDI, as well as MS methods using multiplexing by labelling, which in principle can also be used in combination with liquid AP-MALDI MS

    Shasta County Agriculture Activity Book Project

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    With the development of an agricultural activity book for the kindergarten level, the authors have selected the top commodities produced in Shasta County and have directly applied them to Next Generation Science Standards. The reasoning behind creating a parallel between science lessons and a students’ immediate environment is to allow teachers to utilize their allotted time for teaching for state-mandated subjects while appointing agricultural topics as a vehicle for understanding these lessons

    A new mid-infrared map of the BN/KL region using the Keck telescope

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    We present a new mid-infrared (12.5micron) map of the BN/KL high-mass star-forming complex in Orion using the LWS instrument at Keck I. Despite poor weather we achieved nearly diffraction-limited images (FWHM = 0.38'') over a roughly 25'' X 25'' region centered on IRc2 down to a flux limit of ~250 mJy. Many of the known infrared (IR) sources in the region break up into smaller sub-components. We have also detected 6 new mid-IR sources. Nearly all of the sources are resolved in our mosaic. The near-IR source ''n'' is slightly elongated in the mid-IR along a NW--SE axis and perfectly bisects the double-peaked radio source ''L''. Source n has been identified as a candidate for powering the large IR luminosity of the BN/KL region (L = 10^5 L_sun). We postulate that the 12 micron emission arises in a circumstellar disk surrounding source n. The morphology of the mid-IR emission and the Orion ''hot core'' (as seen in NH_3 emission), along with the location of water and OH masers, is very suggestive of a bipolar cavity centered on source n and aligned with the rotation axis of the hypothetical circumstellar disk. IRc2, once thought to be the dominant energy source for the BN/KL region, clearly breaks into 4 sub-sources in our mosaic, as seen previously at 3.8 -- 5.0 micron. The anti-correlation of mid-IR emission and NH_3 emission from the nearby hot core indicates that the IRc2 sources are roughly coincident (or behind) the dense hot core. The nature of IRc2 is not clear: neither self-luminous sources (embedded protostars) nor external heating by source I can be definitively ruled out. We also report the discovery of a new arc-like feature SW of the BN object, and some curious morphology surrounding near-IR source ''t".Comment: To appear in The Astronomical Journal, July 2004 (16 pages, 7 figures

    Wanderers

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    This book introduces the idea and experience of wandering, as reflected in cultural texts from popular songs to philosophical analysis, providing both a fascinating informal history and a necessary vantage point for understanding - in our era - the emergence of new wanderers.   Wanderers offers a fast-paced, wide-ranging, and compelling introduction to this significant and recurrent theme in literary history. David Brown Morris argues that wandering, as a primal and recurrent human experience, is basic to the understanding of certain literary texts. In turn, certain prominent literary and cultural texts (from Paradise Lost to pop songs, from Wordsworth to the blues, from the Wandering Jew to the film Nomadland) demonstrate how representations of wandering have changed across cultures, times, and genres. Wanderers provides an initial overview necessary to grasp the importance of wandering both as a perennial human experience and as a changing historical event, including contemporary forms such as homelessness and climate migration that make urgent claims upon us.   Wanderers takes you on a thoroughly enjoyable and informative stroll through a significant concept that will be of interest to those studying or researching literature, cultural studies, and philosophy
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