27,917 research outputs found
Mollusca of the Illinois River, Arkansas
The Illinois River is in the Ozark region of northwestern Arkansas and eastern Oklahoma. A survey of the Illinois River in Arkansas produced nine species and one morphological subspecies of gastropods, three species of sphaeriid clams, and 23 species of unionid mussels. Museum records resulted in another two species and an ecophenotype of the Unionidae. This represents the first published survey of molluscan species from the Illinois River in Arkansas
Dynamical control of quantum state transfer within hybrid open systems
We analyze quantum state-transfer optimization within hybrid open systems,
from a "noisy" (write-in) qubit to its "quiet" counterpart (storage qubit).
Intriguing interplay is revealed between our ability to avoid bath-induced
errors that profoundly depend on the bath-memory time and the limitations
imposed by leakage out of the operational subspace. Counterintuitively, under
no circumstances is the fastest transfer optimal (for a given transfer energy)
Molecular Gas in the Powerful Radio Galaxies 3C~31 and 3C~264: Major or Minor Mergers?
We report the detection of CO~() and CO~()
emission from the central regions (--) of the two
powerful radio galaxies 3C~31 and 3C~264. Their individual CO emission exhibits
a double-horned line profile that is characteristic of an inclined rotating
disk with a central depression at the rising part of its rotation curve. The
inferred disk or ring distributions of the molecular gas is consistent with the
observed presence of dust disks or rings detected optically in the cores of
both galaxies. For a CO to H conversion factor similar to that of our
Galaxy, the corresponding total mass in molecular hydrogen gas is in 3C~31 and in 3C~264. Despite their relatively large molecular-gas masses
and other peculiarities, both 3C~31 and 3C~264, as well as many other powerful
radio galaxies in the (revised) 3C catalog, are known to lie within the
fundamental plane of normal elliptical galaxies. We reason that if their gas
originates from the mergers of two gas-rich disk galaxies, as has been invoked
to explain the molecular gas in other radio galaxies, then both 3C~31 and
3C~264 must have merged a long time (a few billion years or more) ago but their
remnant elliptical galaxies only recently (last tens of millions of years or
less) become active in radio. Instead, we argue that the cannibalism of
gas-rich galaxies provides a simpler explanation for the origin of molecular
gas in the elliptical hosts of radio galaxies. Given the transient nature of
their observed disturbances, these galaxies probably become active in radio
soon after the accretion event when sufficient molecular gas agglomerates in
their nuclei.Comment: 16 pages, 1 JPEG figure attached, accepted for publication in ApJ
On Steering Swarms
The main contribution of this paper is a novel method allowing an external
observer/controller to steer and guide swarms of identical and
indistinguishable agents, in spite of the agents' lack of information on
absolute location and orientation. Importantly, this is done via simple global
broadcast signals, based on the observed average swarm location, with no need
to send control signals to any specific agent in the swarm
Dietary modifications for infantile colic
Infantile colic can be defined as periods of inconsolable, unexplained, and incessant crying in a seemingly healthy infant that, quite understandably, leads to exhausted, frustrated, and concerned parents seeking to comfort their child (Landgren 2010).
The prevalence of excessive crying varies according to the definition used although, most often, it peaks during the second month of life,with a prevalence of 1.5%to 11.9%(Reijneveld 2001).Traditionally, the definition of the condition was based on the rule of
three (Wessel 1954): that is, unexplained episodes of paroxysmal crying for more than three hours per day, for three days per week, for at least three weeks. More recently a new definition has been proposed. It refers to a clinical condition of fussing and crying for at least one week in an otherwise healthy infant (Hyman 2006). Colic can be graded as mild, moderate, or severe, though there is no consensus for this classification. Colic can affect up to 10% to 30% of infants worldwide (Clifford 2002; Rosen 2007)
Effective geometry in Astrophysics
The effective metric is introduced by means of two examples (non-linear
electromagnetism and hydrodynamics),along with applications in Astrophysics. A
sketch of the generality of the effect is also given.Comment: 9 pages, contributions for the proceedings of the First International
Workshop on Astronomy and Relativistic Astrophysics (IWARA 2003), Olinda
(Brazil
The Angular Momentum Operator in the Dirac Equation
The Dirac equation in spherically symmetric fields is separated in two
different tetrad frames. One is the standard cartesian (fixed) frame and the
second one is the diagonal (rotating) frame. After separating variables in the
Dirac equation in spherical coordinates, and solving the corresponding
eingenvalues equations associated with the angular operators, we obtain that
the spinor solution in the rotating frame can be expressed in terms of Jacobi
polynomials, and it is related to the standard spherical harmonics, which are
the basis solution of the angular momentum in the Cartesian tetrad, by a
similarity transformation.Comment: 13 pages,CPT-94/P.3027,late
Finnish Industry Investment ltd: an International Evaluation
The Finnish Industry Investment Ltd. (FII) is a government owned investment company, which started its operations in 1995.
Its core purpose is to stimulate the development of the Finnish venture capital industry particularly in those areas where market
failure has constrained the supply of equity finance to high potential, small and medium sized Finnish enterprises. FII invests in
young firms ‘indirectly’ via participating as a cornerstone investor in the new funds of venture capital firms, as well as investing
‘directly’ into Finnish firms.
In common with other European venture capital industries, the Finnish industry grew very rapidly between 1995−2000. However,
the Finnish market is still very small and under-developed by international standards, particularly, if the high knowledge
intensity of the Finnish economy is taken into consideration.
The limited availability of early stage (seed and start-up) venture capital to attractive young firms is the most urgent and persistent
failure in the Finnish venture capital market. The primary policy goal of FII has been to address this problem by helping to
set up, develop, and provide finance to venture capital funds investing in seed and start-up firms. However, FII has also has had
a requirement imposed by government to operate profitably. This has lead the organisation to seek later stage investments in
order to meet the profitability target. FII’s focus on profitability goal and its practice of investing on equal terms with private
investors has lead to a reduction in its effectiveness in resolving the market failure in early stage venture capital. FII’s reduced
impact has occurred at a time of worsening market conditions when the need for effective government intervention is highest.
The main conclusion of the evaluation is that FII should focus its operations more directly on resolving remaining market failures
in the supply of early stage venture capital. The evaluation also argues strongly that FII should concentrate on an indirect
operating mode whereby it finances, and incentivizes by asymmetric profit sharing, private investment professionals to set up
venture capital funds targeted at seed and startup stages. The same indirect approach should also continue to be used to resolve
market failures in the provision of regional venture capital. Additionally, FII has a valuable role in helping channel foreign
capital, including finance from EU, to Finnish early stage venture capital funds. Direct investments by FII to target companies
should be avoided as an operating mode.
Given the FII’s responsibility for addressing market failures, its performance measurement and governance systems should
fully reflect this primary goal. The evaluation also finds that FII’s communication and collaboration with other actors in the
Finnish innovation system should be improved. In addition to the need for improved coordination between the government
special financing agencies, there is also a need for more effective direction and coordination of policy at the highest executive
level, for example in ensuring the integration of enterprise policy and general financial policy to enable significant
improvements in the environment for growth-oriented entrepreneurship in Finland.Commissioned by
Ministry of Trade and Industr
Generalization properties of finite size polynomial Support Vector Machines
The learning properties of finite size polynomial Support Vector Machines are
analyzed in the case of realizable classification tasks. The normalization of
the high order features acts as a squeezing factor, introducing a strong
anisotropy in the patterns distribution in feature space. As a function of the
training set size, the corresponding generalization error presents a crossover,
more or less abrupt depending on the distribution's anisotropy and on the task
to be learned, between a fast-decreasing and a slowly decreasing regime. This
behaviour corresponds to the stepwise decrease found by Dietrich et al.[Phys.
Rev. Lett. 82 (1999) 2975-2978] in the thermodynamic limit. The theoretical
results are in excellent agreement with the numerical simulations.Comment: 12 pages, 7 figure
Vortex lattice stability and phase coherence in three-dimensional rapidly rotating Bose condensates
We establish the general equations of motion for the modes of a vortex
lattice in a rapidly rotating Bose-Einstein condensate in three dimensions,
taking into account the elastic energy of the lattice and the vortex line
bending energy. As in two dimensions, the vortex lattice supports Tkachenko and
gapped sound modes. In contrast, in three dimensions the Tkachenko mode
frequency at long wavelengths becomes linear in the wavevector for any
propagation direction out of the transverse plane. We compute the correlation
functions of the vortex displacements and the superfluid order parameter for a
homogeneous Bose gas of bounded extent in the axial direction. At zero
temperature the vortex displacement correlations are convergent at large
separation, but at finite temperatures, they grow with separation. The growth
of the vortex displacements should lead to observable melting of vortex
lattices at higher temperatures and somewhat lower particle number and faster
rotation than in current experiments. At zero temperature a system of large
extent in the axial direction maintains long range order-parameter correlations
for large separation, but at finite temperatures the correlations decay with
separation.Comment: 10 pages, 2 figures, Changes include the addition of the particle
density - vortex density coupling and the correct value of the shear modulu
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