11,180 research outputs found
SIR-A imagery in geologic studies of the Sierra Madre Oriental, northeastern Mexico. Part 1 (Regional stratigraphy): The use of morphostratigraphic units in remote sensing mapping
SIR-A imaging was used in geological studies of sedimentary terrains in the Sierra Madre Oriental, northeastern Mexico. Geological features such as regional strike and dip, bedding, folding and faulting were readily detected on the image. The recognition of morphostructural units in the imagery, coupled with field verification, enabled geological mapping of the region at the scale of 1:250 000. Structural profiling lead to the elaboration of a morphostructural map allowing the recognition of an echelon folds and field trends which were used to postulate the ectonic setting of the region
Regulation of transforming growth factor-beta 1 gene expression by glucocorticoids in normal human T lymphocytes.
Glucocorticoids (GC) modulate immune function in a number of ways, including suppression of T cell proliferation and other IL-2-mediated T cell functions. These inhibitory effects are similar to those induced by transforming growth factor-beta 1 (TGF-beta 1), a cytokine with potent T cell inhibiting activities. We examined the hypothesis that GC effects may be at least partially achieved through modulation of the expression of the TGF-beta 1 gene in activated T cells. Normal T cells were cultured with or without purified phytohemagglutinin (PHA-p) and 4 beta-phorbol 12-myristate 13-acetate (PMA) in the presence or absence of the synthetic GC, dexamethasone (100-200 micrograms/ml). The production of latent and active forms of TGF beta by these cells were analyzed by immunoblotting and bioassays. The steady-state levels of TGF-beta 1 mRNA were analyzed in total RNA from these cells by Northern hybridizations using a human TGF-beta 1 cDNA. The results showed that dexamethasone caused an increase in TGF beta production and a dose-dependent two to fourfold increase in TGF-beta 1 mRNA in activated as well as in unstimulated T cells, 1 h after exposure of the cultures to the steroid. The increase in TGF-beta 1 mRNA levels by dexamethasone was further potentiated two to threefold by cycloheximide, suggesting that the steroid effect may be due to inhibition of the synthesis of proteins that decrease TGF-beta 1 gene transcription or the stability of its transcripts. Finally, in vitro nuclear transcription studies indicated the dexamethasone effects on TGF-beta 1 gene expression to be largely transcriptional
An Adaptive Sampling Scheme to Efficiently Train Fully Convolutional Networks for Semantic Segmentation
Deep convolutional neural networks (CNNs) have shown excellent performance in
object recognition tasks and dense classification problems such as semantic
segmentation. However, training deep neural networks on large and sparse
datasets is still challenging and can require large amounts of computation and
memory. In this work, we address the task of performing semantic segmentation
on large data sets, such as three-dimensional medical images. We propose an
adaptive sampling scheme that uses a-posterior error maps, generated throughout
training, to focus sampling on difficult regions, resulting in improved
learning. Our contribution is threefold: 1) We give a detailed description of
the proposed sampling algorithm to speed up and improve learning performance on
large images. We propose a deep dual path CNN that captures information at fine
and coarse scales, resulting in a network with a large field of view and high
resolution outputs. We show that our method is able to attain new
state-of-the-art results on the VISCERAL Anatomy benchmark
Charged-current inclusive neutrino cross sections in the SuperScaling model including quasielastic, pion production and meson-exchange contributions
Charged current inclusive neutrino-nucleus cross sections are evaluated using
the superscaling model for quasielastic scattering and its extension to the
pion production region. The contribution of two-particle-two-hole vector
meson-exchange current excitations is also considered within a fully
relativistic model tested against electron scattering data. The results are
compared with the inclusive neutrino-nucleus data from the T2K and SciBooNE
experiments. For experiments where GeV, the
three mechanisms considered in this work provide good agreement with the data.
However, when the neutrino energy is larger, effects from beyond the
also appear to be playing a role. The results show that processes induced by
two-body currents play a minor role at the kinematics considered.Comment: 10 pages, 7 figure
Aplicación de nuevas técnicas docentes en la asignatura Sistemas Cliente/Servidor
En este trabajo mostramos nuestras experiencias en
la aplicación de metodologÃas de aprendizaje cooperativo
y basado en proyectos en la asignatura Sistemas
Cliente/Servidor en los cursos académicos
2008/2009 y 2009/2010.SUMMARY: In this work we present our teaching experience in
the aplication of cooperative and project-based learning
methodologies within the subject Client/Server
Systems in the academic years 2008/2009 and
2009/2010.Peer Reviewe
Linear second-order differential equations for barotropic FRW cosmologies
"Simple linear second-order differential equations have been written down for FRW cosmologies with barotropic fluids by Faraoni. His results have been extended by Rosu, who employed techniques belonging to nonrelativistic supersymmetry to obtain time-dependent adiabatic indices. Further extensions are presented here using the known connection between the linear second-order differential equations and Dirac-like equations in the same supersymmetric context. These extensions are equivalent to adding an imaginary part to the adiabatic index which is proportional to the mass parameter of the Dirac spinor. The natural physical interpretation of the imaginary part is related to the particular dissipation and instabilities of the barotropic FRW hydrodynamics that are introduced by means of this supersymmetric scheme.
Two Cyclocoelids from the Lesser Yellowlegs, Tringa flavipes (Scolopacidae), from the Central Flyway of North America, Including the Description of Haematotrephus selfi n. sp. (Digenea: Cyclocoelidae)
Seven specimens of cyclocoelids (6 specimens representing Haematotrephus selfi n. sp. and 1 specimen representing a second unidentified species of Haematotrephus) collected by the late Dr. J. Teague Self, former professor, Department of Zoology, University of Oklahoma, Norman, Oklahoma, U.S.A., from the body cavities of 3 lesser yellowlegs, Tringa flavipes, (2 birds collected from Roger Mills County, Oklahoma on 23 and 29 August 1963, and 1 collected from Manitoba, Canada on 3 June 1964) and deposited in the Manter Laboratory of Parasitology, University of Nebraska, Lincoln, Nebraska are described. Haematotrephus selfi n. sp. can be distinguished from all other species in the genus that lack an oral sucker except Haematotrephus limnodromi by having intertesticular uterine loops. It most closely resembles H. limnodromi but differs from it by having a smaller body, a smaller pharynx, smaller testes, a shorter cirrus sac, and somewhat smaller eggs. In addition, H. selfi n. sp. lacks a uterine seminal receptacle
A Wild Pseudomonas has appeared: An Exercise in Bacterial Isolation and Identification
The aim of our research was to isolate and identify wild type Pseudomonas putida from soil in various cities of San Gabriel Valley. P. putida iscapable of biomineralization. Biomineralization can potentially be used as a method of phosphorus recovery by using bacteria to produce phosphate rich struvite. In isolating bacteria for further observation, fluorescence was used as a primary determinant in identifying possible Pseudomonas strains as fluorescence is a common trait shared among varying Pseudomonas species; P. putida, P. aeruginosa, P. fluorescens, P. cichorii, P. chlororaphis, P. syringae,and P. aureofaciens. King’s B agar was used to promote the production of pyoverdine in these strains (allowing for direct identification based on a green fluorescence under UV light) as this medium has specific ingredients that enhance pigment production.These fluorescent bacteria were then further isolated from each other and identified using biochemical methods including catalase, oxidase, nitrate reduction, and gelatin hydrolysis tests to differentiate P. putida from the six other fluorescent Pseudomonas species. Of the 21 total samples isolated based on fluorescence, 5 of the samples were determined to be potential P. putida. While the biochemical assays were conducted, the isolated samples were placed in refrigeration for 3 weeks. After the biochemical tests were completed and 3 weeks had passed, visible crystals had formed in the potential P. putida. Albert’s metachromatic staining was performed to determine the presence of polyphosphate granules. Ultimately, each potential P. putida that produced crystals also showed polyphosphate granules when Albert’s stained, which further connects crystal formation with prior polyphosphate formation
Atmospheric Condensed-Phase Reactions of Glyoxal with Methylamine
[1] Glyoxal reacts with methylamine in drying cloud droplet/aerosol surrogates to form high molecular mass oligomers along with smaller amounts of 1,3-dimethylimidazole and light-absorbing compounds. The patterns observed by high-resolution time-of-flight aerosol mass spectrometry indicate that oligomers form from repeated imine units. The reactions are 1st order in each reactant: rate-limiting imine formation is followed by rapid dimer and oligomer formation. While excess methylamine evaporates from the droplet, half the glyoxal does not, due to self-oligomerization reactions that occur in the absence of methylamine. Glyoxal irreversibly traps volatile amine compounds in the aerosol phase, converting them into oligomers. This is the first reported mechanism for the formation of stable secondary organic aerosol (SOA) material from methylamine, a substance with only one carbon, and could produce as much as 11 Tg SOA yr−1 globally if glyoxal reacts exclusively by this pathway
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