474 research outputs found
Competitividad, inversión y crecimiento. Los casos de Colombia, Chile, Perú, Corea y China
En el mundo globalizado, la competitividad es el requisito del crecimiento moderno de unpaís económicamente pequeño, particularmente con una población de ingresos reducidos.Ello es tal porque en ese contexto, producir y vender cada vez más bienes y servicios sólopuede hacerse vendiendo en el exterior, el mercado interno es insuficiente, y para ello sedebe competir en el mercado internacional. Tal competitividad, que es una cuestióneconómica y no administrativa, depende de los precios básicos de la economía que, a suvez, dependen de la política económica vigente. Los casos diferenciales de Colombia,Chile, Perú, Corea y China permiten ilustrar en forma comparativa tal condicionamiento.
MHD simulations of three-dimensional Resistive Reconnection in a cylindrical plasma column
Magnetic reconnection is a plasma phenomenon where a topological
rearrangement of magnetic field lines with opposite polarity results in
dissipation of magnetic energy into heat, kinetic energy and particle
acceleration. Such a phenomenon is considered as an efficient mechanism for
energy release in laboratory and astrophysical plasmas. An important question
is how to make the process fast enough to account for observed explosive energy
releases. The classical model for steady state magnetic reconnection predicts
reconnection times scaling as (where is the Lundquist number) and
yields times scales several order of magnitude larger than the observed ones.
Earlier two-dimensional MHD simulations showed that for large Lundquist number
the reconnection time becomes independent of ("fast reconnection" regime)
due to the presence of the secondary tearing instability that takes place for
. We report on our 3D MHD simulations of magnetic
reconnection in a magnetically confined cylindrical plasma column under either
a pressure balanced or a force-free equilibrium and compare the results with 2D
simulations of a circular current sheet. We find that the 3D instabilities
acting on these configurations result in a fragmentation of the initial current
sheet in small filaments, leading to enhanced dissipation rate that becomes
independent of the Lundquist number already at .Comment: 11 pages, 11 figures, accepted for publication in MNRA
Crescentic flap for the reconstruction of the nose after skin cancer resection
Purpose Non-melanoma skin cancers are the most frequent skin tumours; in 25.5% of cases, they are reported to affect the nasal area. For an excellent surgical outcome, first of all the radical excision of the lesion is important, with appropriate margins of healthy skin in order to avoid recurrences. Moreover is important to achieve a good aesthetical result, avoiding distortion of the aesthetic units and preserving their functions. Material and methods We have applied the modified crescentic flap, described by Smadja in 2007, to 24 nasal skin defects left by oncologic surgery. It consists of the crescent-shaped resection of Burow's triangle all around the alar groove that allows the advancement of the flap to the tip of the nose, hiding the scar in the alar groove. Results The outcome and the long-term follow-up were completely satisfactory both for patients and for surgeons. Conclusion For skin defects localized in the midline or paramedian line of the dorsum of the nose, the crescentic flap seems to be a good solution to obtain the better aesthetic result with respect to both anatomy and function of the nasal area, sparing the patient a second intervention or an overly invasive procedure
La inclusión de los pequeños productores agrícolas en el desarrollo económico colombiano
Colombian rural development is the core of Chapter 1 of the Peace Agreement between the Colombian Government and the FARC. The negotiators of the Agreement, albeit from different perspectives, recognized the urgent need to promote the Colombian rural development to overcome its traditional backwardness and thus, handle better, economic and social conflicts in these rural areas. In this regard, the Government of President Santos has been developing «Colombia Sows», the public comprehensive policy to enhance agricultural production. However, it looks that it would not meet expectations. Moreover, there is still the implementation of several of the policies required to achieve rural development and the inclusion of small rural producers.El desarrollo rural colombiano es el tema del capítulo 1 del acuerdo de paz entre el Gobierno colombiano y las FARC. Los negociadores del acuerdo, aunque desde diferentes perspectivas, reconocieron la necesidad urgente de promover el desarrollo rural colombiano para superar su tradicional atraso y manejar así, de mejor manera, los conflictos económicos y sociales en las zonas rurales. Al respecto, el Gobierno de presidente Santos ha venido desarrollando Colombia Siembra, la política pública integral para mejorar la producción agrícola. No obstante, Colombia Siembra no cumpliría con las expectativas. Más aún, falta la implementación de varias de las políticas públicas requeridas para lograr ese desarrollo rural y la inclusión de los pequeños productores rurales
Lo screening della disfunzione ventricolare sinistra sistolica asintomatica in un campione di popolazione ad alto rischio cardiovascolare in Lombardia: lo studio DAVID-Berg
Background. Prevalence of asymptomatic left ventricular systolic dysfunction (ALVSD) increases with age and cardiovascular (CV) risk exposure. Early diagnosis and treatment allow reducing heart failure and fatal and non-fatal event rates. Data on ALVSD prevalence in Italy are still scarce and ALVSD remains commonly under-diagnosed in primary care, where diagnostic facilities are limited. Among subjects at high CV risk in primary care, we assessed the prevalence of ALVSD and the relative predictive value of N-terminal pro-brain natriuretic peptide (NT-proBNP) and the Framingham Heart Failure Risk Score (FHFRS). Conclusions. In subjects at high CV risk in primary care, prevalence of ALVSD is 5.3%; for diagnosis NT-proBNP adds predictive value to the FHFRS and is equivalent to the combination of FHFRS and ECG. Because of its practical advantages, NT-proBNP might be routinely used for ALVSD screening in primary care
Profile of gamma-delta (γδ) T lymphocytes in the peripheral blood of crossbreed dogs during stages of life and implication in aging
Abstract
Background: Data on gamma-delta (γδ) T lymphocytes in the peripheral blood of dogs are scant, related only to healthy pure breed dogs and limited to a restricted age range. The aim of the study was to investigate the modulation of the γδ T lymphocyte (TCRγδ+) subpopulation in peripheral blood of crossbreed healthy dogs according to five identified stages of life: Puppy, Junior, Adult, Mature, Senior and to determine its implication in aging.
A rigorous method of recruitment was used to minimize the influence of internal or external pressure on the immune response. Twenty-three intact female and twenty-four intact male dogs were enrolled. Blood samples were collected and immunophenotyping of peripheral blood T lymphocytes and γδ T cell subpopulations was performed.
Results: The percentage of γδ T cells in peripheral blood lymphocytes was comparable with the value of 2.5% published by Faldyna and co-workers (2001), despite the percentage reported was investigated in less arranged age range groups and coming from four different dog pure breeds, whereas our data were recorded on wider age range groups and coming from crossbreed dogs. Therefore, the γδ T cell percentage (2.5%) is consistent and points out that such value is breed-independent. Statistical analysis highlighted differences in both percentage and absolute γδ T cells according to the stage of life. γδ T cells decreased significantly in the peripheral blood of elder dogs (Senior group) in comparison with previous stages of life (Puppy, Junior, and Adult groups). Differences in γδ T cells are significant and they are reported, for the first time, related to dog aging.
Conclusions: The study confirms dogs to be among the animals with a low TCRγδ+ cell profile. A decrease of the TCRγδ+ subpopulation percentage was observed in elder dogs. TCRγδ+ cells of group S were different from those of groups P, J, and A. The differences are reported for the first time in dog aging. Identifying the stage of life when the decrease of γδ T lymphocytes starts can be useful for providing a rationale for drafting a wellness plan trial to support thymus immune functions and mitigate its functional exhaustion
Convolutional neural network (CNN)-enabled electrocardiogram (ECG) analysis: a comparison between standard twelve-lead and single-lead setups
Epithelial to Mesenchymal Transition (EMT) in a Laryngeal Squamous Cell Carcinoma of a Horse: Future Perspectives
Squamous cell carcinoma (SCC) is one of the most frequent tumors of skin and muco-cutaneous junctions in the horse. Equine papillomavirus type 2 (EcPV2) has been detected in equine SCC of the oral tract and genitals, and recently also in the larynx. As human squamous cell carcinoma of the larynx (SCCL), it is strongly etiologically associated with high-risk papillomavirus (h-HPV) infection. This study focuses on tumor cells behavior in a naturally occurring tumor that can undergo the so-called epithelial to mesenchymal transition (EMT). A SCCL in a horse was investigated by immunohistochemistry using antibodies against E-cadherin, pan-cytokeratin AE3/AE1, β-catenin, N-cadherin, vimentin, ZEB-1, TWIST, and HIF-1α. EcPV2 DNA detection and expression of oncogenes in SCC were investigated. A cadherin switch and an intermediate filaments rearrangement within primary site tumor cells together with the expression of the EMT-related transcription factors TWIST-1, ZEB-1, and HIF-1α were observed. DNA obtained from the tumor showed EcPV2 positivity, with E2 gene disruption and E6 gene dysregulation. The results suggest that equine SCCL might be a valuable model for studying EMT and the potential interactions between EcPV2 oncoproteins and the EMT process in SCCL
Evaluation of safety and efficacy of DNA vaccines against bovine herpesvirus-1 (BoHV-1) in calves.
Four DNA vaccines against BoHV-1 were evaluated for their efficacy in calves. Twelve animals were divided into four groups which were injected with four different DNA vaccines: pVAX-tgD (Vaccine A); pVAX-tgD co-immunised with pVAX-48CpG (Vaccine B); pVAX-UbiLacl-tgD-L (Vaccine C); pVAX-UbiLacl-tgD-L co-immunised with pVAX-48CpG (Vaccine D). Three additional calves were given the plasmid vector and served as controls. Ninety days after the first vaccination all calves were challenge infected with BoHV-1.
All animals developed a severe form of infections bovine rhinotracheitis. Only the calves given the pVAX-tgD co-immunised with pVAX-48CpG (Vaccine B) developed humoral antibodies against BoHV-1 between 56 and 90 days after the first vaccination, whereas in calves of other groups and in the controls, antibodies appeared only after the infection. In the calves vaccinated with either pVAX-tgD (Vaccine A) or pVAX-tgD combined with pVAX-48CpG (Vaccine B), BoHV-1-specific IFN-gamma secreting cells were detected in PBMCs 90 days after the first vaccination and their number increased after challenge exposure. In the other groups the IFN-gamma secreting cells were detected after virus infection and at low values
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