1,123 research outputs found
Preparation of dihydrolipoamide by electrolytic reduction
Numeración errónea en el original
Weathering Tight Economic Times: The Sales Evolution Of Consumer Durables Over The Business Cycle
Despite its obvious importance, not much marketing research focuses on how business-cycle fluctuations affect individual companies and/or industries. Often, one only has aggregate information on the state of the national economy, even though cyclical contractions and expansions need not have an equal impact on every industry, nor on all firms in that industry. Using recent time-series developments, we introduce various measures to quantify the extent and nature of business-cycle fluctuations in sales. Specifically, we discuss the notions of cyclical volatility and cyclical comovement, and consider two types of cyclical asymmetry related, respectively, to the relative size of the peaks and troughs and the rate of change in upward versus downward parts of the cycle. In so doing, we examine how consumers adjust their purchasing behavior across different phases of the business cycle. We apply these concepts to a broad set (24) of consumer durables, for which we analyze the cyclical sensitivity in their sales evolution. In that way, we (i) derive a novel set of empirical generalizations, and (ii) test different marketing theory-based hypotheses on the underlying drivers of cyclical sensitivity.
Consumer durables are found to be more sensitive to business-cycle fluctuations than the general economic activity, as expressed in an average cyclical volatility of more than four times the one in GNP, and an average comovement elasticity in excess of 2. This observation calls for an explicit consideration of cyclical variation in durable sales. Moreover, even though no evidence is found for depth asymmetry, the combined evidence across all durables suggests that asymmetry is present in the speed of up- and downward movements, as durable sales fall much quicker during contractions than they recover during economic expansions. Finally, key variables related to the industry's pricing activities, the nature of the durable (convenience vs. leisure), and the stage in a product's life cycle tend to moderate the extent of cyclical sensitivity in durable sales patterns
Spectral Orbits and Peak-to-Average Power Ratio of Boolean Functions with respect to the {I,H,N}^n Transform
We enumerate the inequivalent self-dual additive codes over GF(4) of
blocklength n, thereby extending the sequence A090899 in The On-Line
Encyclopedia of Integer Sequences from n = 9 to n = 12. These codes have a
well-known interpretation as quantum codes. They can also be represented by
graphs, where a simple graph operation generates the orbits of equivalent
codes. We highlight the regularity and structure of some graphs that correspond
to codes with high distance. The codes can also be interpreted as quadratic
Boolean functions, where inequivalence takes on a spectral meaning. In this
context we define PAR_IHN, peak-to-average power ratio with respect to the
{I,H,N}^n transform set. We prove that PAR_IHN of a Boolean function is
equivalent to the the size of the maximum independent set over the associated
orbit of graphs. Finally we propose a construction technique to generate
Boolean functions with low PAR_IHN and algebraic degree higher than 2.Comment: Presented at Sequences and Their Applications, SETA'04, Seoul, South
Korea, October 2004. 17 pages, 10 figure
Cavity atom optics and the `free atom laser'
The trap environment in which Bose-Einstein condensates are generated and/or
stored strongly influences the way they interact with light. The situation is
analogous to cavity QED in quantum optics, except that in the present case, one
tailors the matter-wave mode density rather than the density of modes of the
optical field. Just as in QED, for short times, the atoms do not sense the trap
and propagate as in free space. After times long enough that recoiling atoms
can probe the trap environment, however, the way condensates and light fields
are mutually influenced differs significantly from the free-space situation. We
use as an example the condensate collective atomic recoil laser, which is the
atomic matter-wave analog of the free-electron laser.Comment: To be published in a special edition of Optics Communications in
honor of the 60th birthday of Marlan Scull
Patterns and outcomes of preterm hospital admissions during pregnancy in NSW, 2001-2008
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Multifetal pregnancies: preterm admissions and outcomes
Objective.
To describe the rates of antenatal hospital admission during twin or higher order multifetal pregnancies, and the admission outcomes as discharge undelivered, transfer to higher care, or spontaneous or elective delivery.
Methods.
Cohort study using linked birth and hospital data. The cohort comprised women who gave birth to twins or higher order multiple infants of ≥ 24 weeks gestation in 2001–2008 and who were admitted to hospital in weeks 20–36 of the pregnancy.
Results.
In 63.4% of 10 779 twin pregnancies and 99.5% of 197 triplet and quadruplet pregnancies, the woman was admitted to hospital at least once in weeks 20–36 of the pregnancy, for a total 10 985 admissions. Almost half the admissions (46.3%) ended in discharge without delivery, 10.7% in transfer to higher care, 21.1% in spontaneous labour and birth, and 21.8% in elective delivery (induction or prelabour Caesarean section). The reason for admission was preterm labour in 34.2% of admissions.
Conclusions.
Hospital admission during pregnancy is common for women with multifetal pregnancies, with many of these admissions resulting in preterm birth. This is the first study to report the rate of pregnancy admissions for women with multifetal pregnancies, and provides a baseline for future studies of hospital use in this population.
What is known about the topic?
Multifetal pregnancies are high risk and require greater medical care than singleton pregnancies. However, few studies specifically examine multifetal pregnancies, and most pregnancy studies exclude them, so there is little known about the resource use of this group.
What does this paper add?
This is the first paper to report population rates of hospital admission during pregnancy for women with multifetal pregnancies. We report the admission rates, and the admission outcomes as discharge undelivered, transfer to higher care or spontaneous or elective delivery.
What are the implications for practitioners?
Most women with multifetal pregnancies are admitted to hospital at least once during the pregnancy, with 51% of these admissions resulting in preterm delivery. Of those discharged undelivered, 60% were admitted for 1 day or less. This has implications for resource use, proposed place of birth and for practitioners advising pregnant women.
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Modeling magnetospheric fields in the Jupiter system
The various processes which generate magnetic fields within the Jupiter
system are exemplary for a large class of similar processes occurring at other
planets in the solar system, but also around extrasolar planets. Jupiter's
large internal dynamo magnetic field generates a gigantic magnetosphere, which
is strongly rotational driven and possesses large plasma sources located deeply
within the magnetosphere. The combination of the latter two effects is the
primary reason for Jupiter's main auroral ovals. Jupiter's moon Ganymede is the
only known moon with an intrinsic dynamo magnetic field, which generates a
mini-magnetosphere located within Jupiter's larger magnetosphere including two
auroral ovals. Ganymede's magnetosphere is qualitatively different compared to
the one from Jupiter. It possesses no bow shock but develops Alfv\'en wings
similar to most of the extrasolar planets which orbit their host stars within
0.1 AU. New numerical models of Jupiter's and Ganymede's magnetospheres
presented here provide quantitative insight into the processes that maintain
these magnetospheres. Jupiter's magnetospheric field is approximately
time-periodic at the locations of Jupiter's moons and induces secondary
magnetic fields in electrically conductive layers such as subsurface oceans. In
the case of Ganymede, these secondary magnetic fields influence the oscillation
of the location of its auroral ovals. Based on dedicated Hubble Space Telescope
observations, an analysis of the amplitudes of the auroral oscillations
provides evidence that Ganymede harbors a subsurface ocean. Callisto in
contrast does not possess a mini-magnetosphere, but still shows a perturbed
magnetic field environment. Callisto's ionosphere and atmospheric UV emission
is different compared to the other Galilean satellites as it is primarily been
generated by solar photons compared to magnetospheric electrons.Comment: Chapter for Book: Planetary Magnetis
The Legacy of ERA, Privatization and the Policy Ratchet
This article explores the ways in which the neo-liberal impetus toward the privatization of state schooling signalled in the Education Reform Act 1988 (ERA) has become embedded in the English school system. Four main points are made. First, that ERA itself was of huge strategic rather than substantive importance as far as privatization is concerned. Second, by tracing the lineage of privatization from ERA onwards a 'ratchet' effect of small and incremental policy moves can be identified, which have disseminated, embedded and naturalized privatization within public sector provision. Third, that while privatization has been taken up and taken much further by New Labour than it had been by the Conservatives there are differences between the two sets of governments in the role of privatization in education policy and the role of the state. Fourth, the participation of private providers in the planning and delivery of state services has put the private sector at the very heart of policy. At points the article draws upon interviews conducted with private sector providers. © 2008 Sage Publications
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