210 research outputs found
An open hardware electronic controller for motorized rotary injection valves used in flow injection analysis
This work presents the design, development
and the implementation of a motorized
injection valve used in Flow Injection
Analysis systems. The built prototype has been
developed based on the open hardware, software and
firmware, emergent philosophy thus helping the
development of a free and independent science. This
policy creates a platform of open projects that feed
each other, contributing to scientific and technological
development while sharing knowledge. The proposed
design project can be modified to implant it in other
devices or projects according to the needs of each one.
Also, the open project can be a great help as teaching
material in Universities, since open hardware projects
are fully described and documented
Composición Arquitectónica 5 y 6
La presente Memoria culmina el trabajo colaborativo del área de conocimiento de Composición Arquitectónica por lo que respecta a las materias de Grado en (Fundamentos en) Arquitectura, al haber definido sus contenidos, sus métodos de aprendizaje y sus sistemas de evaluación para el conjunto de la titulación. Ahora se concretan las dos últimas asignaturas de 5º curso: CA5 y CA6. Por un lado está CA5, cuyo eje fundamental es la definición de criterios para el ejercicio de la crítica de arquitectura, una vez que se ha construido una base de información histórica y teórica en los estudiantes a lo largo de cuatro cursos. Una crítica entendida tanto como sistema de contextualización sobre las obras ejecutadas (del presente o del pasado) y, a la vez, como marco de referencia para someter a evaluación las soluciones que se proponen desde proyecto (desde el presente hacia el futuro). Así pues, crítica entendida como herramienta de análisis tanto como de prospección. Por otro lado está CA6, en la que el eje fundamental es la intervención sobre el patrimonio arquitectónico, sea o no monumental, entendido como una realidad ineludible pues gran parte del trabajo de los arquitectos transita sobre preexistencias en sus muy diversos grados
A note on supersymmetric Yang-Mills thermodynamics
The thermodynamics of supersymmetric Yang-Mills theories is studied by
computing the two-loop correction to the canonical free energy and to the
equation of state for theories with 16, 8 and 4 supercharges in any dimension
, and in two dimensions at finite volume. In the
four-dimensional case we also evaluate the first non-analytic contribution in
the 't Hooft coupling to the free energy, arising from the resummation of ring
diagrams. To conclude, we discuss some applications to the study of the
Hagedorn transition in string theory in the context of Matrix strings and
speculate on the possible physical meaning of the transition.Comment: 19 pages, harvmac, epsf. 1 figure included. Minor changes: typos
corrected; references, a footonote and a note adde
Duality in Non-Trivially Compactified Heterotic Strings
We study the implications of duality symmetry on the analyticity properties
of the partition function as it depends upon the compactification length. In
order to obtain non-trivial compactifications, we give a physical prescription
to get the Helmholtz free energy for any heterotic string supersymmetric or
not. After proving that the free energy is always invariant under the duality
transformation and getting the zero temperature
theory whose partition function corresponds to the Helmholtz potential, we show
that the self-dual point is a generic singularity
as the Hagedorn one. The main difference between these two critical
compactification radii is that the term producing the singularity at the
self-dual point is finite for any . We see that this behavior at
actually implies a loss of degrees of freedom below that point.Comment: (Preprint No. FTUAM-92/12) 17 page
Lattice Perturbation Theory in Noncommutative Geometry and Parity Anomaly in 3D Noncommutative QED
We formulate lattice perturbation theory for gauge theories in noncommutative
geometry. We apply it to three-dimensional noncommutative QED and calculate the
effective action induced by Dirac fermions. In particular "parity invariance"
of a massless theory receives an anomaly expressed by the noncommutative
Chern-Simons action. The coefficient of the anomaly is labelled by an integer
depending on the lattice action, which is a noncommutative counterpart of the
phenomenon known in the commutative theory. The parity anomaly can also be
obtained using Ginsparg-Wilson fermions, where the masslessness is guaranteed
at finite lattice spacing. This suggests a natural definition of the
lattice-regularized Chern-Simons theory on a noncommutative torus, which could
enable nonperturbative studies of quantum Hall systems.Comment: 31 pages. LaTeX, feynmf. Minor changes, references added and typos
corrected. Final version published in JHE
microRNA Expression and Its Association With Disability and Brain Atrophy in Multiple Sclerosis Patients Treated With Glatiramer Acetate.
Background: MicroRNAs are small non-coding RNA that regulate gene expression at a
post-transcriptional level affecting several cellular processes including inflammation,
neurodegeneration and remyelination. Different patterns of miRNAs expression have
been demonstrated in multiple sclerosis compared to controls, as well as in different
courses of the disease. For these reason they have been postulated as promising
biomarkers candidates in multiple sclerosis.
Objective: To correlate serum microRNAs profile expression with disability, cognitive
functioning and brain volume in patients with remitting-relapsing multiple sclerosis.
Methods: Cross-sectional study in relapsing-remitting multiple sclerosis patients treated
with glatiramer acetate. Disability was measured with Expanded Disability Status Scale
(EDSS) and cognitive function was studied with Symbol Digit Modalities Test (SDMT).
Brain volume was analyzed with automatic software NeuroQuant®
.
Results: We found an association between miR.146a.5p (rs:0.434, p=0.03) and miR.9.5p
(rs:0.516, p=0.028) with EDSS; and miR-146a.5p (rs:-0.476, p=0.016) and miR-126.3p
(rs:-0.528, p=0.007) with SDMT. Regarding to the brain volume, miR.9.5p correlated with
thalamus (rs:-0.545, p=0.036); miR.200c.3p with pallidum (rs:-0.68, p=0.002) and
cerebellum (rs:-0.472, p=0.048); miR-138.5p with amygdala (rs:0.73, p=0.016) and
pallidum (rs:0.64, p=0.048); and miR-223.3p with caudate (rs:0.46, p=0.04).
Conclusions: These data support the hypothesis of microRNA as potential biomarkers in
this disease. More studies are needed to validate these results and to better understand
the role of microRNAs in the pathogenesis, monitoring and therapeutic response of
multiple sclerosis.post-print1410 K
El fons antic de la Biblioteca Pública de Palma: estat de la seva catalogació i perspectives de futur
Modulation of KV4.3-KChIP2 Channels by IQM-266: Role of DPP6 and KCNE2
The transient outward potassium current (Itof) is generated by the activation of KV4 channels assembled with KChIP2 and other accessory subunits (DPP6 and KCNE2). To test the hypothesis that these subunits modify the channel pharmacology, we analyzed the electrophysiological effects of (3-(2-(3-phenoxyphenyl)acetamido)-2-naphthoic acid) (IQM-266), a new KChIP2 ligand, on the currents generated by KV4.3/KChIP2, KV4.3/KChIP2/DPP6 and KV4.3/KChIP2/KCNE2 channels. CHO cells were transiently transfected with cDNAs codifying for different proteins (KV4.3/KChIP2, KV4.3/KChIP2/DPP6 or KV4.3/KChIP2/KCNE2), and the potassium currents were recorded using the whole-cell patch-clamp technique. IQM-266 decreased the maximum peak of KV4.3/KChIP2, KV4.3/KChIP2/DPP6 and KV4.3/KChIP2/KCNE2 currents, slowing their time course of inactivation in a concentration-, voltage-, time- and use-dependent manner. IQM-266 produced an increase in the charge in KV4.3/KChIP2 channels that was intensified when DPP6 was present and abolished in the presence of KCNE2. IQM-266 induced an activation unblocking effect during the application of trains of pulses to cells expressing KV4.3/KChIP2 and KV4.3/KChIP2/KCNE2, but not in KV4.3/KChIP2/DPP6 channels. Overall, all these results are consistent with a preferential IQM-266 binding to an active closed state of Kv4.3/KChIP2 and Kv4.3/KChIP2/KCNE2 channels, whereas in the presence of DPP6, IQM-266 binds preferentially to an inactivated state. In conclusion, DPP6 and KCNE2 modify the pharmacological response of KV4.3/KChIP2 channels to IQM-266
Graviton emission in Einstein-Hilbert gravity
The five-point amplitude for the scattering of two distinct scalars with the
emission of one graviton in the final state is calculated in exact kinematics
for Einstein-Hilbert gravity. The result, which satisfies the Steinmann
relations, is expressed in Sudakov variables, finding that it corresponds to
the sum of two gauge invariant contributions written in terms of a new two
scalar - two graviton effective vertex. A similar calculation is carried out in
Quantum Chromodynamics (QCD) for the scattering of two distinct quarks with one
extra gluon in the final state. The effective vertices which appear in both
cases are then evaluated in the multi-Regge limit reproducing the well-known
result obtained by Lipatov where the Einstein-Hilbert graviton emission vertex
can be written as the product of two QCD gluon emission vertices, up to
corrections to preserve the Steinmann relations.Comment: 28 pages, LaTeX, feynmf. v2: typos corrected, reference added. Final
version to appear in Journal of High Energy Physic
Bosonic D-branes at finite temperature with an external field
Bosonic boundary states at finite temperature are constructed as solutions of
boundary conditions at for bosonic open strings with a constant gauge
field coupled to the boundary. The construction is done in the
framework of thermo field dynamics where a thermal Bogoliubov transformation
maps states and operators to finite temperature. Boundary states are given in
terms of states from the direct product space between the Fock space of the
closed string and another identical copy of it. By analogy with zero
temperature, the boundary states heve the interpretation of -brane at
finite temperature. The boundary conditions admit two different solutions. The
entropy of the closed string in a -brane state is computed and analysed. It
is interpreted as the entropy of the -brane at finite temperature.Comment: 21 pages, Latex, revised version with minor corrections and
references added, to be published in Phys. Rev.
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