2,957 research outputs found
NUV/Blue spectral observations of sprites in the 320-460 nm region: (2PG) Emissions
A near-ultraviolet (NUV) spectrograph (320-460 nm) was flown on the EXL98
aircraft sprite observation campaign during July 1998. In this wavelength range
video rate (60 fields/sec) spectrographic observations found the NUV/blue
emissions to be predominantly N2 (2PG). The negligible level of N2+ (1NG)
present in the spectrum is confirmed by observations of a co-aligned, narrowly
filtered 427.8 nm imager and is in agreement with previous ground-based
filtered photometer observations. The synthetic spectral fit to the
observations indicates a characteristic energy of ~1.8 eV, in agreement with
our other NUV observations.Comment: 7 pages, 2 figures, 1 table, JGR Space Physics "Effects of
Thunderstorms and Lightning in the Upper Atmosphere" Special Sectio
Ultralight reactive metal foams produced as structural shapes in space: System design
This autonomous experiment for foaming metals in space involved: (1) payload support structure; (2) furnace and foaming apparatus; (3) electronic controls; (4) battery power; and (5) metallurgy. Emphasis was laid on a modular design which was easily modifiable and which offered maximum durability, safety, and failure tolerance
Effect of calf-starter protein solubility on calf performance
Three starters containing differently processed protein supplements were fed
to Holstein heifer calves, using an early weaning program. One starter contained
soybean meal. The other starters contained soybean grits processed through an
extrusion cooker to reduce the protein solubility to an intermediate (PDI> 50%) or
low (PDI < 15 %) level. Calf performance was similar on all three starters
Solving Games with Functional Regret Estimation
We propose a novel online learning method for minimizing regret in large
extensive-form games. The approach learns a function approximator online to
estimate the regret for choosing a particular action. A no-regret algorithm
uses these estimates in place of the true regrets to define a sequence of
policies.
We prove the approach sound by providing a bound relating the quality of the
function approximation and regret of the algorithm. A corollary being that the
method is guaranteed to converge to a Nash equilibrium in self-play so long as
the regrets are ultimately realizable by the function approximator. Our
technique can be understood as a principled generalization of existing work on
abstraction in large games; in our work, both the abstraction as well as the
equilibrium are learned during self-play. We demonstrate empirically the method
achieves higher quality strategies than state-of-the-art abstraction techniques
given the same resources.Comment: AAAI Conference on Artificial Intelligence 201
Overtly anaphoric control in type logical grammar
In this paper we analyse anaphoric pronouns in control sentences and we investigate the implications of these kinds of sentences in relation to the Propositional Theory versus Property Theory question. For these purposes, we invoke the categorial calculus with limited contraction, a conservative extension of Lambek calculus that builds contraction into the logical rules for a customized slash type-constructor.Peer ReviewedPostprint (author's final draft
UV solar irradiance in observations and the NRLSSI and SATIRE-S models
Total solar irradiance and UV spectral solar irradiance have been monitored
since 1978 through a succession of space missions. This is accompanied by the
development of models aimed at replicating solar irradiance by relating the
variability to solar magnetic activity. The NRLSSI and SATIRE-S models provide
the most comprehensive reconstructions of total and spectral solar irradiance
over the period of satellite observation currently available. There is
persistent controversy between the various measurements and models in terms of
the wavelength dependence of the variation over the solar cycle, with
repercussions on our understanding of the influence of UV solar irradiance
variability on the stratosphere. We review the measurement and modelling of UV
solar irradiance variability over the period of satellite observation. The
SATIRE-S reconstruction is consistent with spectral solar irradiance
observations where they are reliable. It is also supported by an independent,
empirical reconstruction of UV spectral solar irradiance based on UARS/SUSIM
measurements from an earlier study. The weaker solar cycle variability produced
by NRLSSI between 300 and 400 nm is not evident in any available record. We
show that although the method employed to construct NRLSSI is principally
sound, reconstructed solar cycle variability is detrimentally affected by the
uncertainty in the SSI observations it draws upon in the derivation. Based on
our findings, we recommend, when choosing between the two models, the use of
SATIRE-S for climate studies
Utilization of near infrared reflectance spectroscopy for prediction of the nutritional composition of beef and pork samples
Near-infrared reflectance spectroscopy
(NIRS) offers the potential for rapid, low-cost
analyses of meat samples. Beef and pork
samples were analyzed by both standard
laboratory (AOAC) methods and NIRS.
Regression equations were developed to relate
the two methods. Coefficients of determination
between NIRS and AOAC results were .929 for
dry matter, .965 for crude protein, and .996 for
ether extract. NIRS and AOAC procedures
yielded very similar results (DM, 38.82 vs
38.58; CP, 17.78 vs. 17.83; and EE, 18.83 vs.
18.00). NIRS appears to be a rapid and reliable
predictor of nutritional composition of ground
beef and pork based on regression equations we
have developed with a limited number of
samples
Synthesis and reactivity of N-allenyl cyanamides
N-Allenyl cyanamides have been accessed via a one-pot deoxycyanamidation–isomerization approach using propargyl alcohol and N-cyano-N-phenyl-p-methylbenzenesulfonamide. The utility of this novel class of allenamide was explored through derivatization, with hydroarylation, hydroamination, and cycloaddition protocols employed to access an array of cyanamide products that would be challenging to access using existing methods
Leukocyte function and health status of calves supplemented with vitamins A and E
Forty-four Holstein calves were fed milk
replacers with varied concentrations of vitamins
A and E from 3 to 45 d of age to determine their
effects on concentrations of plasma vitamin A
(retinol and retinyl palmitate) and vitamin E (a-
tocopherol), lymphocyte and neutrophil functions,
and health of calves. Plasma a-tocopherol was
unaffected by increased vitamin A supplementation.
Fecal scores, and eye and nose membrane
responses were improved with increased vitamin
A and lower vitamin E concentration, whereas the
same treatment tended to reduce neutrophil
cytotoxic and bactericidal activity by 6 wk of age.
Increased supplemental vitamin E tended to
enhance neutrophil functions. However, age
appeared to have an effect on response to both
vitamins
Magnesiate addition/ring-expansion strategy to access the 6-7-6 tricyclic core of hetisine-type C20-diterpenoid alkaloids
A synthetic strategy to access the fused 6–7–6 tricyclic core of hetisine-type C20-diterpenoid alkaloids is reported. This strategy employs a Diels–Alder cycloaddition to assemble a fused bicyclic anhydride intermediate, which is elaborated to a vinyl lactone-acetal bearing an aromatic ring in five steps. Aromatic iodination is followed by magnesium–halogen exchange with a trialkyl magnesiate species, which undergoes intramolecular cyclization. Subsequent oxidation provides the desired 6–7–6 tricyclic diketoaldehyde, with carbonyl groups at all three positions for eventual C–N bond formation and subsequent elaboration
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