2,684 research outputs found
The adhering junction dynamics in the testis are regulated by an interplay of beta 1-integrin, focal adhesion kinase (FAK) and the focal adhesion complex (FAC)-associated proteins
published_or_final_versio
Banach Analytic Sets and a Non-Linear Version of the Levi Extension Theorem
We prove a certain non-linear version of the Levi extension theorem for
meromorphic functions. This means that the meromorphic function in question is
supposed to be extendable along a sequence of complex curves, which are
arbitrary, not necessarily straight lines. Moreover, these curves are not
supposed to belong to any finite dimensional analytic family. The conclusion of
our theorem is that nevertheless the function in question meromorphically
extends along an (infinite dimensional) analytic family of complex curves and
its domain of existence is a pinched domain filled in by this analytic family.Comment: 19 pages, This is the final version with significant corrections and
improvements. To appear in Arkiv f\"or matemati
Section Extension from Hyperbolic Geometry of Punctured Disk and Holomorphic Family of Flat Bundles
The construction of sections of bundles with prescribed jet values plays a
fundamental role in problems of algebraic and complex geometry. When the jet
values are prescribed on a positive dimensional subvariety, it is handled by
theorems of Ohsawa-Takegoshi type which give extension of line bundle valued
square-integrable top-degree holomorphic forms from the fiber at the origin of
a family of complex manifolds over the open unit 1-disk when the curvature of
the metric of line bundle is semipositive. We prove here an extension result
when the curvature of the line bundle is only semipositive on each fiber with
negativity on the total space assumed bounded from below and the connection of
the metric locally bounded, if a square-integrable extension is known to be
possible over a double point at the origin. It is a Hensel-lemma-type result
analogous to Artin's application of the generalized implicit function theorem
to the theory of obstruction in deformation theory. The motivation is the need
in the abundance conjecture to construct pluricanonical sections from flatly
twisted pluricanonical sections. We also give here a new approach to the
original theorem of Ohsawa-Takegoshi by using the hyperbolic geometry of the
punctured open unit 1-disk to reduce the original theorem of Ohsawa-Takegoshi
to a simple application of the standard method of constructing holomorphic
functions by solving the d-bar equation with cut-off functions and additional
blowup weight functions
Low cost high efficiency GaAs monolithic RF module for SARSAT distress beacons
Low cost high performance (5 Watts output) 406 MHz beacons are urgently needed to realize the maximum utilization of the Search and Rescue Satellite-Aided Tracking (SARSAT) system spearheaded in the U.S. by NASA. Although current technology can produce beacons meeting the output power requirement, power consumption is high due to the low efficiency of available transmitters. Field performance is currently unsatisfactory due to the lack of safe and reliable high density batteries capable of operation at -40 C. Low cost production is also a crucial but elusive requirement for the ultimate wide scale utilization of this system. Microwave Monolithics Incorporated (MMInc.) has proposed to make both the technical and cost goals for the SARSAT beacon attainable by developing a monolithic GaAs chip set for the RF module. This chip set consists of a high efficiency power amplifier and a bi-phase modulator. In addition to implementing the RF module in Monolithic Microwave Integrated Circuit (MMIC) form to minimize ultimate production costs, the power amplifier has a power-added efficiency nearly twice that attained with current commercial technology. A distress beacon built using this RF module chip set will be significantly smaller in size and lighter in weight due to a smaller battery requirement, since the 406 MHz signal source and the digital controller have far lower power consumption compared to the 5 watt power amplifier. All the program tasks have been successfully completed. The GaAs MMIC RF module chip set has been designed to be compatible with the present 406 MHz signal source and digital controller. A complete high performance low cost SARSAT beacon can be realized with only additional minor iteration and systems integration
Fermionic Modular Categories and the 16-fold Way
We study spin and super-modular categories systematically as inspired by
fermionic topological phases of matter, which are always fermion parity
enriched and modelled by spin TQFTs at low energy. We formulate a -fold way
conjecture for the minimal modular extensions of super-modular categories to
spin modular categories, which is a categorical formulation of gauging the
fermion parity. We investigate general properties of super-modular categories
such as fermions in twisted Drinfeld doubles, Verlinde formulas for naive
quotients, and explicit extensions of with an eye towards a
classification of the low-rank cases.Comment: Latest post-referee version. Many typos fixed, many explanations
expanded, several inconsistencies corrected. 8 figure
On the cohomology of pseudoeffective line bundles
The goal of this survey is to present various results concerning the
cohomology of pseudoeffective line bundles on compact K{\"a}hler manifolds, and
related properties of their multiplier ideal sheaves. In case the curvature is
strictly positive, the prototype is the well known Nadel vanishing theorem,
which is itself a generalized analytic version of the fundamental
Kawamata-Viehweg vanishing theorem of algebraic geometry. We are interested
here in the case where the curvature is merely semipositive in the sense of
currents, and the base manifold is not necessarily projective. In this
situation, one can still obtain interesting information on cohomology, e.g. a
Hard Lefschetz theorem with pseudoeffective coefficients, in the form of a
surjectivity statement for the Lefschetz map. More recently, Junyan Cao, in his
PhD thesis defended in Grenoble, obtained a general K{\"a}hler vanishing
theorem that depends on the concept of numerical dimension of a given
pseudoeffective line bundle. The proof of these results depends in a crucial
way on a general approximation result for closed (1,1)-currents, based on the
use of Bergman kernels, and the related intersection theory of currents.
Another important ingredient is the recent proof by Guan and Zhou of the strong
openness conjecture. As an application, we discuss a structure theorem for
compact K{\"a}hler threefolds without nontrivial subvarieties, following a
joint work with F.Campana and M.Verbitsky. We hope that these notes will serve
as a useful guide to the more detailed and more technical papers in the
literature; in some cases, we provide here substantially simplified proofs and
unifying viewpoints.Comment: 39 pages. This survey is a written account of a lecture given at the
Abel Symposium, Trondheim, July 201
\u3ci\u3eMedicine Meets Virtual Reality 16\u3c/i\u3e
Chapter, Validating Advanced Robot-Assisted Laparoscopic Training Task in Virtual Reality, co-authored by Nicholas Stergiou, UNO faculty member.
We humans are tribal, grouping ourselves by a multitude of criteria: physical, intellectual, political, emotional, etc. The Internet and its auxiliary technologies have enabled a novel dimension in tribal behavior during our recent past. This growing connectivity begs the question: will individuals and their communities come together to solve some very urgent global problems? At MMVR, we explore ways to harness information technology to solve healthcare problems – and in the industrialized nations we are making progress. In the developing world however, things are more challenging. Massive urban poverty fuels violence and misery. Will global networking bring a convergence of individual and tribal problem-solving? Recently, a barrel-shaped water carrier that rolls along the ground was presented, improving daily life for many people. Also the One Laptop per Child project is a good example of how the industrialized nations can help the developing countries. They produce durable and simple laptops which are inexpensive to produce. At MMVR, we focus on cutting-edge medical technology, which is generally pretty expensive. While the benefits of innovation trickle downward, from the privileged few to the broader masses, we should expand this trickle into a flood. Can breakthrough applications in stimulation, visualization, robotics, and informatics engender tools as ingeniously as the water carrier or laptop? With some extra creativity, we can design better healthcare for the developing world too.https://digitalcommons.unomaha.edu/facultybooks/1234/thumbnail.jp
Cohomological aspects on complex and symplectic manifolds
We discuss how quantitative cohomological informations could provide
qualitative properties on complex and symplectic manifolds. In particular we
focus on the Bott-Chern and the Aeppli cohomology groups in both cases, since
they represent useful tools in studying non K\"ahler geometry. We give an
overview on the comparisons among the dimensions of the cohomology groups that
can be defined and we show how we reach the -lemma
in complex geometry and the Hard-Lefschetz condition in symplectic geometry.
For more details we refer to [6] and [29].Comment: The present paper is a proceeding written on the occasion of the
"INdAM Meeting Complex and Symplectic Geometry" held in Cortona. It is going
to be published on the "Springer INdAM Series
Cohomology of bundles on homological Hopf manifold
We discuss the properties of complex manifolds having rational homology of
including those constructed by Hopf, Kodaira and
Brieskorn-van de Ven. We extend certain previously known vanishing properties
of cohomology of bundles on such manifolds.As an application we consider
degeneration of Hodge-deRham spectral sequence in this non Kahler setting.Comment: To appear in Proceedings of 2007 conference on Several complex
variables and Complex Geometry. Xiamen. Chin
Computer simulations of electrorheological fluids in the dipole-induced dipole model
We have employed the multiple image method to compute the interparticle force
for a polydisperse electrorheological (ER) fluid in which the suspended
particles can have various sizes and different permittivites. The point-dipole
(PD) approximation being routinely adopted in computer simulation of ER fluids
is shown to err considerably when the particles approach and finally touch due
to multipolar interactions. The PD approximation becomes even worse when the
dielectric contrast between the particles and the host medium is large. From
the results, we show that the dipole-induced-dipole (DID) model yields very
good agreements with the multiple image results for a wide range of dielectric
contrasts and polydispersity. As an illustration, we have employed the DID
model to simulate the athermal aggregation of particles in ER fluids both in
uniaxial and rotating fields. We find that the aggregation time is
significantly reduced. The DID model accounts for multipolar interaction
partially and is simple to use in computer simulation of ER fluids.Comment: 22 pages, 7 figures, submitted to Phys. Rev.
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