6,181 research outputs found
Modelling the Product Development performance of Colombian Companies
Organised by: Cranfield UniversityThis paper presents the general model of the Product Development Process (PDP) in the Metal mechanics
Industry in Barranquilla-Colombia, since this sector contributes significantly to the productivity of this
industrial city. This case study counted on a five-company sample. The main goal was to model the current
conditions of the PDP according to the Concurrent Engineering philosophy. The companies were selected
according to their productive profile, in order to contrast differences regarding the structure of their
productive processes, conformation of multidisciplinary teams, integration of different areas, customers and
suppliers to the PDP; human resources, information, technology and marketing constraints.Mori Seiki â The Machine Tool Compan
Relativistic Compact Objects in Isotropic Coordinates
We present a matrix method for obtaining new classes of exact solutions for
Einstein's equations representing static perfect fluid spheres. By means of a
matrix transformation, we reduce Einstein's equations to two independent
Riccati type differential equations for which three classes of solutions are
obtained. One class of the solutions corresponding to the linear barotropic
type fluid with an equation of state is discussed in detail.Comment: 9 pages, no figures, accepted for publication in Pramana-Journal of
Physic
Three axis vector magnet set-up for cryogenic scanning probe microscopy
We describe a three axis vector magnet system for cryogenic scanning probe microscopy measurements. We discuss the magnet support system and the power supply, consisting of a compact three way 100 A current source. We obtain tilted magnetic fields in all directions with maximum value of 5T along z-axis and of 1.2T for XY-plane magnetic fields. We describe a scanning tunneling microscopy-spectroscopy (STM-STS) set-up, operating in a dilution refrigerator, which includes a new high voltage ultralow noise piezodrive electronics and discuss the noise level due to vibrations. STM images and STS maps show atomic resolution and the tilted vortex lattice at 150 mK in the superconductor ÎČ-Bi2Pd. We observe a strongly elongated hexagonal lattice, which corresponds to the projection of the tilted hexagonal vortex lattice on the surface. We also discuss Magnetic Force Microscopy images in a variable temperature insertThis work was supported by Convocatoria Doctorados en el Exterior 568-2012 COLCIENCIAS, the Spanish MINECO (FIS2011-23488, MAT2011-27470-C02-02, CSD2009-00013), by the Comunidad de Madrid through program Nanofrontmag-CM (S2013/MIT-2850) and by Marie-Curie actions under the project FP7-PEOPLE-2013- CIG-618321. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement No. 604391 Graphene Flagship. We also acknowledge Banco Santander, COST MP1201. J.A. and C.M. acknowledge the FPI (BES- 2012-058600) and Juan de la Cierva (JCI-2011-08815) programs, respectivel
The Prevalence of Latent Mycobacterium Tuberculosis Infection Based on an Interferon-Îł Release Assay: A Cross-Sectional Survey Among Urban Adults in Mwanza, Tanzania.
One third of the world's population is estimated to be latently infected with Mycobacterium tuberculosis (LTBI). Surveys of LTBI are rarely performed in resource poor TB high endemic countries like Tanzania although low-income countries harbor the largest burden of the worlds LTBI. The primary objective was to estimate the prevalence of LTBI in household contacts of pulmonary TB cases and a group of apparently healthy neighborhood controls in an urban setting of such a country. Secondly we assessed potential impact of LTBI on inflammation by quantitating circulating levels of an acute phase reactant: alpha-1-acid glycoprotein (AGP) in neighborhood controls. The study was nested within the framework of two nutrition studies among TB patients in Mwanza, Tanzania. Household contacts- and neighborhood controls were invited to participate. The study involved a questionnaire, BMI determination and blood samples to measure AGP, HIV testing and a Quantiferon Gold In tube (QFN-IT) test to detect signs of LTBI. 245 household contacts and 192 neighborhood controls had available QFN-IT data. Among household contacts, the proportion of QFT-IT positive was 59% compared to 41% in the neighborhood controls (pâ=â0.001). In a linear regression model adjusted for sex, age, CD4 and HIV, a QFT-IT positive test was associated with a 10% higher level of alpha-1-acid glycoprotein(AGP) (10(B) 1.10, 95% CI 1.01; 1.20, pâ=â0.03), compared to individuals with a QFT-IT negative test. LTBI is highly prevalent among apparently healthy urban Tanzanians even without known exposure to TB in the household. LTBI was found to be associated with elevated levels of AGP. The implications of this observation merit further studies
An improved method for statistical studies of the internal kinematics of HII regions: the case of M 83
We present the integrated Halpha emission line profile for 157 HII regions in
the central 3.4' x 3.4' of the galaxy M 83 (NGC 5236). Using the Fabry-Perot
interferometer GHaFaS, on the 4.2 m William Herschel on La Palma, we show the
importance of a good characterization of the instrumental response function for
the study of line profile shapes. The luminosity-velocity dispersion relation
is also studied, and in the log(L)-log(sigma) plane we do not find a linear
relation, but an upper envelope with equation log(L)=0.9 *log(sigma)+38.1. For
the adopted distance of 4.5 Mpc, the upper envelope appears at the luminosity
L=10^38.5 ergs, in full agreement with previous studies of other galaxies,
reinforcing the idea of using HII regions as standard candles.Comment: 13 pages, 9 figures, accepted for publication in MNRA
A rotating three component perfect fluid source and its junction with empty space-time
The Kerr solution for empty space-time is presented in an ellipsoidally
symmetric coordinate system and it is used to produce generalised ellipsoidal
metrics appropriate for the generation of rotating interior solutions of
Einstein's equations. It is shown that these solutions are the familiar static
perfect fluid cases commonly derived in curvature coordinates but now endowed
with rotation. The resulting solutions are also discussed in the context of
T-solutions of Einstein's equations and the vacuum T-solution outside a
rotating source is presented. The interior source for these solutions is shown
not to be a perfect fluid but rather an anisotropic three component perfect
fluid for which the energy momentum tensor is derived. The Schwarzschild
interior solution is given as an example of the approach.Comment: 14 page
Physiological lentiviral vectors for the generation of improved CAR-T cells
Anti-CD19 chimeric antigen receptor (CAR)-T cells have achieved impressive outcomes for the treatment of relapsed and refractory B-lineage neoplasms. However, important limitations still remain due to severe adverse events (i.e., cytokine release syndrome and neuroinflammation) and relapse of 40%-50% of the treated patients. Most CAR-T cells are generated using retroviral vectors with strong promoters that lead to high CAR expression levels, tonic signaling, premature exhaustion, and overstimulation, reducing efficacy and increasing side effects. Here, we show that lentiviral vectors (LVs) expressing the transgene through a WAS gene promoter (AW-LVs) closely mimic the T cell receptor (TCR)/CD3 expression kinetic upon stimulation. These AW-LVs can generate improved CAR-T cells as a consequence of their moderate and TCR-like expression profile. Compared with CAR-T cells generated with human elongation factor alpha (EF1 alpha)-driven-LVs, AW-CAR-T cells exhibited lower tonic signaling, higher proportion of naive and stem cell memory T cells, less exhausted phenotype, and milder secretion of tumor necrosis factor alpha (TNF-alpha) and interferon (IFN)-gamma after efficient destruction of CD19(+) lymphoma cells, both in vitro and in vivo. Moreover, we also showed their improved efficiency using an in vitro CD19(+) pancreatic tumor model. We finally demonstrated the feasibility of large-scale manufacturing of AW-CAR-T cells in guanosine monophosphate (GMP)-like conditions. Based on these data, we propose the use of AWLVs for the generation of improved CAR-T products
The QUEST RR Lyrae Survey: Confirmation of the Clump at 50 kpc and Other Over-Densities in the Outer Halo
We have measured the periods and light curves of 148 RR Lyrae variables from
V=13.5 to 19.7 from the first 100 sq. degrees of the QUEST RR Lyrae survey.
Approximately 55% of these stars belong to the clump of stars detected earlier
by the Sloan Digital Sky Survey. According to our measurements, this feature
has ~10 times the background density of halo stars, spans at least 37.5 deg by
3.5 deg in right ascension and declination (>=30 by >=3 kpc), lies ~50 kpc from
the Sun, and has a depth along the line of sight of ~5 kpc (1 sigma). These
properties are consistent with the recent models that suggest it is a tidal
stream from the Sgr dSph galaxy. The mean period of the type ab variables, 0.58
d, is also consistent. In addition, we have found two smaller over-densities in
the halo, one of which may be related to the globular cluster Pal 5.Comment: 12 pages (including 4 figures). Accepted for publication in the ApJ
Letter
Neuropathic Pain in Dogs and Cats: Current Evaluation and Treatment Perspectives: Review
Abstract: During the past decade, the number of scientific papers on the recognition and multimodal management of pain in small animals increased exponentially. However, the variable of neuropathic pain, or adaptive disorder, has not yet been characterized completely. Its genesis is related to several diseases and injuries of the nervous system that change the neuroanatomical structures that participate in pain processing. Finding novel neurobiological mechanisms and the development of techniques for diagnosis and treatment in Human Medicine, are opening great opportunities for research and the understanding of neuropathic pain in pets
Discovery of the Optical Transient of the Gamma Ray Burst 990308
The optical transient of the faint Gamma Ray Burst 990308 was detected by the
QUEST camera on the Venezuelan 1-m Schmidt telescope starting 3.28 hours after
the burst. Our photometry gives , , , and for times ranging from 3.28 to 3.47
hours after the burst. The colors correspond to a spectral slope of close to
. Within the standard synchrotron fireball model,
this requires that the external medium be less dense than , the
electrons contain of the shock energy, and the magnetic field energy
must be less than 24% of the energy in the electrons for normal interstellar or
circumstellar densities. We also report upper limits of at 132 s
(with LOTIS), from 132-1029s (with LOTIS), at 28.2 min
(with Super-LOTIS), and a 8.5 GHz flux of at 110 days (with the
Very Large Array). WIYN 3.5-m and Keck 10-m telescopes reveal this location to
be empty of any host galaxy to and . The lack of a host
galaxy likely implies that it is either substantially subluminous or more
distant than a red shift of .Comment: ApJ Lett submitted, 5 pages, 2 figures, no space for 12 coauthor
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