Historia de la matemática: integración cultural de las matemáticas, génesis de los conceptos y orientación de su enseñanza

Este informe busca reclamar una función didáctica para la historia de las matemáticas, justificando el hecho de que una comprensión completa y profunda de los conceptos fundamentales de cualquier ciencia requiere el conocimiento de su historia. La naturaleza lógica-deductiva excesiva de las matemáticas actuales ha dado lugar a un dogmatismo excesivo en su enseñanza, junto con una imposición de exactitud y rigor como los valores fundamentales, casi exclusivos, de las matemáticas, influyendo así en la respuesta negativa de los estudiantes. Creemos que estas deficiencias pueden corregirse mediante la enseñanza de la historia de las matemáticas, para enriquecer las enseñanzas culturalmente. Sugerimos que esta asignatura se integre interdisciplinariamente en el plan de estudios y se considere una fuente de inspiración, capacitación permanente y orientación para toda la actividad educativa

Producción de leche por hectárea con vacas Holstein de dos potenciales genéticos en la sabana de Bogotá.

Ganado de leche-Ganadería lecheMaestría en CienciasMaestrí

Programa Agropecuario Municipal: formulación del proyecto de asistencia técnica agrícola y pecuaria para pequeños productores

Este documento presenta una serie de formatos, que en términos generales, van a permitir proyectar la cobertura geográfica, poblacional, de área y población animal que se busca atender. Igualmente poder plantear los rendimientos y volumenes de la producción agrícola y pecuaria que se pretender obtener. Con base en lo anterior se podran formular las actividades a realizar, los costos en que se incurrirá y la cantidad de recursas físicos y humanos necesarios para la prestación de la Asistencia Técnica

Warm ionized gas in the blue compact galaxy Haro 14 viewed by MUSE

We investigate the warm ionized gas in the blue compact galaxy (BCG) Haro 14 by means of integral field spectroscopic observations taken with the Multi Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope. The large field of view of MUSE and its unprecedented sensitivity enable observations of the galaxy nebular emission up to large galactocentric distances, even in the important but very faint [O i] λ6300 diagnostic line. This allowed us to trace the ionized gas morphology and ionization structure of Haro 14 up to kiloparsec scales and, for the first time, to accurately investigate the excitation mechanism operating in the outskirts of a typical BCG. The intensity and diagnostic maps reveal at least two highly distinct components of ionized gas: the bright central regions, mostly made of individual clumps, and a faint component which extends up to kiloparsec scales and consists of widespread diffuse emission, well-delineated filamentary structures, and faint knots. Noteworthy are the two curvilinear filaments extending up to 2 and 2.3 kpc southwest, which likely trace the edges of supergiant expanding bubbles driven by galactic outflows. We find that while the central clumps in Haro 14 are Hii-region complexes, the morphology and line ratios of the whole low-surface-brightness component are not compatible with star formation photoionization. In the spatially resolved emission-line-ratio diagnostic diagrams, spaxels above the maximum starburst line form the majority (∼75% and ∼50% in the diagnostic diagrams involving [O i] and [S ii] respectively). Moreover, our findings suggest that more than one alternative mechanism is ionizing the outer galaxy regions. The properties of the diffiuse component are consistent with ionization by diluted radiation and the large filaments and shells are most probably shocked areas at the edge of bubbles. The mechanism responsible for the ionization of the faint individual clumps observed in the galaxy periphery is more difficult to assess. These clumps could be the shocked debris of fragmented shells or regions where star formation is proceeding under extreme conditions

Recovery of lactose and proteins from cheese whey with poly(ethylene)glycol/sulfate aqueous two-phase systems

Cheese whey is an environmental problem as an effluent, but also a source of valuable raw materials, namely proteins and lactose. In this work, Aqueous Two-Phase Systems (ATPS) were studied for the recovery of lactose, BSA, β-lactoglobulin and α-lactalbumin, key components of cheese whey. ATPS formed by PEG (molecular weights: 200–8000 g.mol−1) with sodium or ammonium sulfate were investigated. Partitioning of the selected solutes was experimentally addressed in different ATPS and pH values. Partition behavior showed that ATPS formed by PEG1500/ammonium sulfate is able to separate lactose from proteins, while PEG300/sodium sulfate ATPS may be used for protein fractionation. These separation strategies were then tested with simulated and real cheese whey. Under optimized conditions, PEG 1500/ammonium sulfate ATPS allows efficient recovery of > 95% proteins (precipitate) and 80% of lactose (bottom phase), as confirmed for both simulated and real cheese whey. The results found indicate that the proposed polymer/salt ATPS can be used to design scalable and cost-effective separation strategies to apply in cheese whey and other related wastes.publishe

Use of cultured human epithelium for coverage : a defect of radial forearm free flap donor site

The radial forearm free flap has been popular in many areas of reconstructive surgery. Despite the many attributes of this flap in maxillofacial reconstruction, one of the disadvantages has been the morbidity of the donor site. Allogeneic cultured epidermis has been successfully applied on large second degree burns and on chronic leg ulcers. Autologous human keratinocytes and fibroblast equivalents can be cultured in-vitro from a small skin sample in order to produce a sufficient amount of epithelial autografts to cover the large defects of third-degree burn wounds. Interestingly, transplanted cultured epidermis retains characteristics of the original donor site. We report a case of a patient who underwent skin replacement by cultured epithelial autograft after wound breakdown occurred in the forearm donor site during the early postoperative period. This method could represent an auspicious alternative to conventional grafting methods for forearm free flap reconstruction. To the best of our knowledge, skin replacement by cultured epithelial autografts in this region has not been extensively described in the literature

Plus ça change : pots, crucibles and the development of metallurgy in Chalcolithic Las Pilas (Mojácar, Spain)

This paper considers the structure of production, distribution and consumption of ceramics within Chalcolithic communities of SE Iberia, an important region for modelling social and technological change in the recent prehistory of Eurasia. Our research provides new data through the comparative analysis of domestic and metallurgical ceramics, as well as building and other clay-rich materials from the archaeological site of Las Pilas (2875–2620 cal. BC 2σ to 2460–2205 cal. BC 2σ) (Mojácar, Almería). In total, 56 samples are characterised by optical petrography, with SEM analysis of 22 of those individuals, in order to assess firing conditions. Results point to the existence of a local tradition in which domestic and metallurgical wares exhibit important similarities in their production processes. In terms of technology, the assemblage shows a relative homogeneity, although firing conditions, surface treatment and decoration seem to have played an important role in the differentiation of highly symbolic wares from other ceramics. We conclude that raw material procurement and processing at Las Pilas differ from those at other Copper Age sites already studied in SE and SW Iberia. This is in agreement with earlier archaeometallurgical studies on Las Pilas, suggesting the development of local and community-based technological traditions. As such, the paper attempts to bridge the recent divide between re-emergent top-down models and our detailed understandings of technological practice

An infinite family of magnetized Morgan-Morgan relativistic thin disks

Applying the Horsk\'y-Mitskievitch conjecture to the empty space solutions of Morgan and Morgan due to the gravitational field of a finite disk, we have obtained the corresponding solutions of the Einstein-Maxwell equations. The resulting expressions are simply written in terms of oblate spheroidal coordinates and the solutions represent fields due to magnetized static thin disk of finite extension. Now, although the solutions are not asymptotically flat, the masses of the disks are finite and the energy-momentum tensor agrees with the energy conditions. Furthermore, the magnetic field and the circular velocity show an acceptable physical behavior.Comment: Submitted to IJTP. This paper is a revised and extended version of a paper that was presented at arXiv:1006.203

Integrating clinical research in an operative screening and diagnostic breast imaging department: First experience, results and perspectives using microwave imaging.

Clinical research is crucial for evaluating new medical procedures and devices. It is important for healthcare units and hospitals to minimize the disruptions caused by conducting clinical studies; however, complex clinical pathways require dedicated recruitment and study designs.This work presents the effective introduction of novel microwave breast imaging (MBI), via MammoWave apparatus, into the clinical routine of an operative screening and diagnostic breast imaging department for conducting a multicentric clinical study. Microwave breast imaging, using MammoWave apparatus, was performed on volunteers coming from different clinical pathways. Clinical data, comprising demographics and conventional radiologic reports (used as reference standard), was collected; a satisfaction questionnaire was filled by every volunteer. Microwave images were analyzed by an automatic clinical decision support system, which quantified their corresponding features to discriminate between breasts with no relevant radiological findings (NF) and breasts with described findings (WF). Conventional breast imaging (DBT, US, MRI) and MBI were performed and adapted to assure best clinical practices and optimum pathways. 180 volunteers, both symptomatic and asymptomatic, were enrolled in the study. After microwave images' quality assessment, 48 NF (15 dense) and 169 WF (88 dense) breasts were used for the prospective study; 48 (18 dense) breasts suffered from a histology-confirmed carcinoma. An overall sensitivity of 85.8 % in breasts lesions' detection was achieved by the microwave imaging apparatus. An optimum recruitment strategy was implemented to assess MBI. Future trials may show the clinical usefulness of microwave imaging, which may play an important role in breast screening. [Abstract copyright: © 2023 The Authors.

Wormholes and Ringholes in a Dark-Energy Universe

The effects that the present accelerating expansion of the universe has on the size and shape of Lorentzian wormholes and ringholes are considered. It is shown that, quite similarly to how it occurs for inflating wormholes, relative to the initial embedding-space coordinate system, whereas the shape of the considered holes is always preserved with time, their size is driven by the expansion to increase by a factor which is proportional to the scale factor of the universe. In the case that dark energy is phantom energy, which is not excluded by present constraints on the dark-energy equation of state, that size increase with time becomes quite more remarkable, and a rather speculative scenario is here presented where the big rip can be circumvented by future advanced civilizations by utilizing sufficiently grown up wormholes and ringholes as time machines that shortcut the big-rip singularity.Comment: 11 pages, RevTex, to appear in Phys. Rev.