8,583 research outputs found
Path-programmable logic
Journal ArticlePath-Programmable Logic (PPL) is a structured IC design methodology under development at the University of Utah. PPL employs a sea-of-wires approach to design. In PPL, design is done entirely using cells for both functionality and interconnect. PPL cells may have modifiers that change either their connections or functionality. Wires in the PPL design plane are segmentable at any cell boundary. PPL is implemented as a set of cell libraries (NMOS, CMOS, and GaAs) and a suite of tools that permit the designer to create, modify, simulate and check PPL circuit designs and to generate mask data for them. PPL exhibits little or no area penalty with respect to full custom densities while permitting system design to be done more rapidly than with gate arrays or standard cells. PPL may be implemented as a sea-of-gates gate array to provide fast turnaround
The path programmable logic (PPL) user's manual
Journal ArticleThis manual describes the primitive NMOS path programmable logic cells currently in use at the University of Utah. It contains detailed descriptions, schematics and composite layout of all cells. Also included are PPL programming rules as well as layout design rules for each cell set
Spontaneous Chelation-Driven Reduction of the Neptunyl Cation in Aqueous Solution.
Octadentate hydroxypyridinone (HOPO) and catecholamide (CAM) siderophore analogues are known to be efficacious chelators of the actinide cations, and these ligands are also capable of facilitating both activation and reduction of actinyl species. Utilizing X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopies, as well as cyclic voltammetry measurements, herein, we elucidate chelation-based mechanisms for driving reactivity and initiating redox processes in a family of neptunyl-HOPO and CAM complexes. Based on the selected chelator, the ability to control the oxidation state of neptunium and the speed of reduction and concurrent oxo group activation was demonstrated. Most notably, reduction kinetics for the NpV O2 +/ /NpIV redox couple upon chelation by the ligands 3,4,3-LI(1,2-HOPO) and 3,4,3-LI(CAM)2 (1,2-HOPO)2 was observed to be faster than ever reported, and in fact quicker than we could measure using either X-ray absorption spectroscopy or electrochemical techniques
Rapid GRB Follow-up with the 2-m Robotic Liverpool Telescope
We present the capabilities of the 2-m robotic Liverpool Telescope (LT),
owned and operated by Liverpool John Moores University and situated at ORM, La
Palma. Robotic control and scheduling of the LT make it especially powerful for
observations in time domain astrophysics including: (i) rapid response to
Targets of Opportunity: Gamma Ray Bursts, novae, supernovae, comets; (ii)
monitoring of variable objects on timescales from seconds to years, and (iii)
observations simultaneous or coordinated with other facilities, both
ground-based and from space. Following a GRB alert from the Gamma Ray
Observatories HETE-2, INTEGRAL and Swift we implement a special over-ride mode
which enables observations to commence in about a minute after the alert,
including optical and near infrared imaging and spectroscopy. In particular,
the combination of aperture, site, instrumentation and rapid response (aided by
its rapid slew and fully-opening enclosure) makes the LT excellently suited to
help solving the mystery of the origin of optically dark GRBs, for the
investigation of short bursts (which currently do not have any confirmed
optical counterparts) and for early optical spectroscopy of the GRB phenomenon
in general. We briefly describe the LT's key position in the RoboNet-1.0
network of robotic telescopes.Comment: 6 pages, 2 figures, to appear in the proceedings of Interacting
Binaries: Accretion, Evolution and Outcomes, 4-10 July 2004, Cefalu, Sicily,
Italy, eds. Antonelli et a
Interplays of psychometric abilities on learning gross anatomy
In recent years, there has been international debate concerning how students learn anatomy. The rapid increase in scientific knowledge has put pressure on the place of anatomy within the medical and allied health professional curricula, as well as the design and structure of anatomy courses. In this regard, relatively little is known about what medical and allied health professions students want from an anatomy course or how they learn it. To assess students’ learning approaches and perceptions of anatomy, a series of psychometric tests were administered to Medical (n=82), Podiatry (n=21), and Pharmacy (n=74) students in the United Kingdom. Analysis of the Anatomy Learning Experience (ALE) questionnaire revealed a predominantly positive attitude towards anatomy and the dissection room, with most valuing cadaveric dissection and not regarding it as a daunting environment. Further to this, analysis of the Approaches to Studying Inventory for Students (ASSIST) revealed predominant preferences for strategic and deep approaches. Personality traits were associated with certain learning approaches; neuroticism with surface (p=0.038), conscientiousness with both a deep and strategic approach (p=0.000 and p=0.060 respectively). Certain personality traits were also found to be associated with anatomy experience e.g. neuroticism and achievement striving felt the most effective way to learn was to get their hands in and feel for structures (p=0.044 and p=0.012 respectively). This study concludes that undergraduate students of medicine, podiatry and pharmacy learn anatomy in slightly different ways. Preparation for classroom activities should centre on the promotion of an optimum learning environment and teaching strategies which promote a deep approach to learning. Understanding students’ personality and learning experiences should help teachers improve the students’ learning of anatomy for effective application to clinical practice
Detection Of KOI-13.01 Using The Photometric Orbit
We use the KOI-13 transiting star-planet system as a test case for the
recently developed BEER algorithm (Faigler & Mazeh 2011), aimed at identifying
non-transiting low-mass companions by detecting the photometric variability
induced by the companion along its orbit. Such photometric variability is
generated by three mechanisms, including the beaming effect, tidal ellipsoidal
distortion, and reflection/heating. We use data from three Kepler quarters,
from the first year of the mission, while ignoring measurements within the
transit and occultation, and show that the planet's ephemeris is clearly
detected. We fit for the amplitude of each of the three effects and use the
beaming effect amplitude to estimate the planet's minimum mass, which results
in M_p sin i = 9.2 +/- 1.1 M_J (assuming the host star parameters derived by
Szabo et al. 2011). Our results show that non-transiting star-planet systems
similar to KOI-13.01 can be detected in Kepler data, including a measurement of
the orbital ephemeris and the planet's minimum mass. Moreover, we derive a
realistic estimate of the amplitudes uncertainties, and use it to show that
data obtained during the entire lifetime of the Kepler mission, of 3.5 years,
will allow detecting non-transiting close-in low-mass companions orbiting
bright stars, down to the few Jupiter mass level. Data from the Kepler Extended
Mission, if funded by NASA, will further improve the detection capabilities.Comment: Accepted to AJ on October 4, 2011. Kepler Q5 Long Cadence data will
become publicly available on MAST by October 23. Comments welcome (V2: minor
changes, to reflect proof corrections
Seasonal and Interspecific Variation in Frugivory by a Mixed Resident-Migrant Overwintering Songbird Community
Many temperate passerine bird species switch from diets of mostly invertebrates in the spring and summer to diets that include fruit and seeds in the fall and winter. However, relatively few studies have quantified diet composition or the extent of seasonal shifts during the non-breeding period, particularly among species and across communities with both residents and migrants. We measured carbon and nitrogen stable isotope values in food items (fruits, C3 and C4seeds, and insects from various trophic levels and plant communities) and in multiple tissues (feathers and plasma/whole blood) from 11 species of songbirds wintering in the southeastern U.S. We combined these diet and tissue values with empirically derived discrimination factors and used concentration-dependent mixing models to quantify seasonal diet shifts. We also validated mixing model results with data from fecal samples. Diets in this bird community, as delineated N and C isotopic space, diverged in the fall and winter relative to the summer as consumption of fruits and seeds increased. Across this songbird community, estimated contributions of fruit to plasma/whole blood increased from 16.2 ± 7.5% in the fall (mean ± SD; range: 4–26%) to 21.7 ± 10.3% (range: 9–37%) in the winter, while contributions of seeds increased from 29.4 ± 2.6% (range: 28–32%) in the fall to 36.6 ± 4.8% (range: 32–42%) in the winter. Fecal data showed qualitatively similar trends to mixing models, but consistently estimated higher contributions of fruit. Our work indicates that fruits and seeds constitute substantial sources of sustenance for non-breeding songbirds, there is considerable separation of resource use among species in the fall and winter, and fecal estimates of contributions to songbird tissues should be interpreted cautiously
The Automatic Real-Time GRB Pipeline of the 2-m Liverpool Telescope
The 2-m Liverpool Telescope (LT), owned by Liverpool John Moores University,
is located in La Palma (Canary Islands) and operates in fully robotic mode. In
2005, the LT began conducting an automatic GRB follow-up program. On receiving
an automatic GRB alert from a Gamma-Ray Observatory (Swift, INTEGRAL, HETE-II,
IPN) the LT initiates a special override mode that conducts follow-up
observations within 2-3 min of the GRB onset. This follow-up procedure begins
with an initial sequence of short (10-s) exposures acquired through an r' band
filter. These images are reduced, analyzed and interpreted automatically using
pipeline software developed by our team called "LT-TRAP" (Liverpool Telescope
Transient Rapid Analysis Pipeline); the automatic detection and successful
identification of an unknown and potentially fading optical transient triggers
a subsequent multi-color imaging sequence. In the case of a candidate brighter
than r'=15, either a polarimetric (from 2006) or a spectroscopic observation
(from 2007) will be triggered on the LT. If no candidate is identified, the
telescope continues to obtain z', r' and i' band imaging with increasingly
longer exposure times. Here we present a detailed description of the LT-TRAP
and briefly discuss the illustrative case of the afterglow of GRB 050502a,
whose automatic identification by the LT just 3 min after the GRB, led to the
acquisition of the first early-time (< 1 hr) multi-color light curve of a GRB
afterglow.Comment: PASP, accepted (8 pages, 3 figures
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