577 research outputs found
Forma: Force reconstruction via maximum-likelihood-estimator analysis
We propose an algorithm to retrieve the conservative and non-conservative components of a force field acting on a Brownian particle from the analysis of its displacements with important advantages over established techniques
Effects of different culture conditions (photoautotrophic, photomixotrophic) and the auxin indole-butyric acid on the in vitro acclimatization of papaya (Carica papaya L. var. Red Maradol) plants using zeolite as support
Plant regeneration of papaya via organogenesis and somatic embryogenesis has been successful; however, the biggest problem of in vitro culture of this species is the acclimatization of regenerated plants, where over 70% of the plants are lost before being planted in the field. Decreasing the relative humidity inside the culture vessel and thus increasing the ventilation, appears to have a greater effect on the adaptation of papaya plants, strengthening the function of the stomata and with this, allowing better control of water loss from the leaves. The aim of this study was to determine the effects of different concentrations of sucrose and indole-butyric acid (IBA) on rooting and in vitro acclimatization of plants using sterile zeolite as support and culture vessels with increased ventilation. Three concentrations of sucrose (0, 10 and 20 g L-1) were studied with and without auxin and as the control treatment, the rooting culture medium with agar during 17, 27 and 37 culture days. The highest percentage of rooting was recorded at 37 culture days in the treatment without sucrose and IBA with 80.0% and zeolite as support. The best photosynthetic values were achieved when in vitro shoots were grown in culture medium with auxin and different concentrations of sucrose, even though they were also high in the treatment without the presence of IBA and without sucrose at 17 days of culture. The combined effect of the zeolite, auxin (IBA), without sucrose in the culture medium and increased ventilation allowed photoautotrophic culture conditions which had effect of the increasing plant survival under ex vitro acclimatization conditions.Key words: Carica papaya, photosynthesis, roots formation
Correlación entre Antígeno Prostático Específico y Ácido Úrico en Cáncer de Próstata
El adenocarcinoma de próstata (CaP) es la segunda causa de muerte por tumores urológicos. Tanto el antígeno prostático específico (PSA) como el ácido úrico (AU) son estudiados siempre por separado y con diferentes fines.
Evaluando la síntesis, metabolismo, función y excreción de cada uno, ambos muestran cierto grado de relación a estados de hipertrigliceridemia, síndrome metabólico, inflamación y cáncer; pero no hay bibliografía que testifique asociación directa entre ellos. El objetivo de este trabajo es determinar si existe relación entre los niveles séricos de AU y PSA en una población masculina y evaluar las posibles causas de dicha asociación. Se estudió una población de entre 45 y 75 años elegida al azar de una consulta urológica de rutina
Asociación entre Niveles Séricos de Leptina y Prevalencia y Agresividad del Cáncer de Próstata
Estudios recientes indican que el tejido adiposo y las adipoquinas podrían promover o prevenir el desarrollo del Cáncer de Próstata (CaP). La leptina, una de las adipoquinas producidas por el tejido adiposo, tendría un efecto estimulante sobre las
células cancerosas prostáticas induciendo promoción y progresión. El objetivo del presente trabajo es determinar si existe correlación entre la composición corporal y los niveles de leptina con la prevalencia y la agresividad del CaP en Mendoza, Argentina
Investigación en el Laboratorio de Enfermedades Metabólicas y Cáncer: 3 Años Despúes
El Laboratorio de Enfermedades Metabólicas y Cáncer (L.E.M.C) dependiente de la Facultad de Farmacia y Bioquímica (F.F.B) de la Universidad Juan A. Maza fue inaugurado el día 27 de septiembre de 2007, siendo rector el Ing. Carlos Villareal
y decana de F.F.B la Farm. Gabriela Giornelli post obtención de subsidio por concurso abierto. Dicho laboratorio está dirigido por el Dr. José Daniel López Laur y subdirigido por la Dra. Constanza López Fontana y el Prof. Rafael Pérez Elizalde
El Consumo Elevado de Licopeno Sumado a una Ingesta Reducida de Carnes Rojas Aumentan el Poder Antioxidante Total
Los sistemas antioxidantes del organismo son capaces de remover a los radicales libres, protegiendo así al organismo del daño que estos pueden ocasionar, y pueden ser valorados en conjunto mediante la determinación del poder antioxidante total. Este biomarcador puede ser modulado por la alimentación mediante la incorporación de sustancias con propiedades
antioxidantes o prooxidantes
Infectious Offspring: How Birds Acquire and Transmit an Avian Polyomavirus in the Wild
Detailed patterns of primary virus acquisition and subsequent dispersal in wild vertebrate populations are virtually absent. We show that nestlings of a songbird acquire polyomavirus infections from larval blowflies, common nest ectoparasites of cavity-nesting birds, while breeding adults acquire and renew the same viral infections via cloacal shedding from their offspring. Infections by these DNA viruses, known potential pathogens producing disease in some bird species, therefore follow an ‘upwards vertical’ route of an environmental nature mimicking horizontal transmission within families, as evidenced by patterns of viral infection in adults and young of experimental, cross-fostered offspring. This previously undescribed route of viral transmission from ectoparasites to offspring to parent hosts may be a common mechanism of virus dispersal in many taxa that display parental care
Brane-World Gravity
The observable universe could be a 1+3-surface (the "brane") embedded in a
1+3+\textit{d}-dimensional spacetime (the "bulk"), with Standard Model
particles and fields trapped on the brane while gravity is free to access the
bulk. At least one of the \textit{d} extra spatial dimensions could be very
large relative to the Planck scale, which lowers the fundamental gravity scale,
possibly even down to the electroweak ( TeV) level. This revolutionary
picture arises in the framework of recent developments in M theory. The
1+10-dimensional M theory encompasses the known 1+9-dimensional superstring
theories, and is widely considered to be a promising potential route to quantum
gravity. At low energies, gravity is localized at the brane and general
relativity is recovered, but at high energies gravity "leaks" into the bulk,
behaving in a truly higher-dimensional way. This introduces significant changes
to gravitational dynamics and perturbations, with interesting and potentially
testable implications for high-energy astrophysics, black holes, and cosmology.
Brane-world models offer a phenomenological way to test some of the novel
predictions and corrections to general relativity that are implied by M theory.
This review analyzes the geometry, dynamics and perturbations of simple
brane-world models for cosmology and astrophysics, mainly focusing on warped
5-dimensional brane-worlds based on the Randall--Sundrum models. We also cover
the simplest brane-world models in which 4-dimensional gravity on the brane is
modified at \emph{low} energies -- the 5-dimensional Dvali--Gabadadze--Porrati
models. Then we discuss co-dimension two branes in 6-dimensional models.Comment: A major update of Living Reviews in Relativity 7:7 (2004)
"Brane-World Gravity", 119 pages, 28 figures, the update contains new
material on RS perturbations, including full numerical solutions of
gravitational waves and scalar perturbations, on DGP models, and also on 6D
models. A published version in Living Reviews in Relativit
The Evolution of Compact Binary Star Systems
We review the formation and evolution of compact binary stars consisting of
white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and
BHs are thought to be the primary astrophysical sources of gravitational waves
(GWs) within the frequency band of ground-based detectors, while compact
binaries of WDs are important sources of GWs at lower frequencies to be covered
by space interferometers (LISA). Major uncertainties in the current
understanding of properties of NSs and BHs most relevant to the GW studies are
discussed, including the treatment of the natal kicks which compact stellar
remnants acquire during the core collapse of massive stars and the common
envelope phase of binary evolution. We discuss the coalescence rates of binary
NSs and BHs and prospects for their detections, the formation and evolution of
binary WDs and their observational manifestations. Special attention is given
to AM CVn-stars -- compact binaries in which the Roche lobe is filled by
another WD or a low-mass partially degenerate helium-star, as these stars are
thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure
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