Search

An investigation was realized in the region of Pavitas, municipality of La Cumbre, Santa Fe farm, 1480 meters above sea level in a soil of Pavas Association (Aeric Tropaquept) to prove the plastic cup-sustrate-plant model in the production of Batavia lecttuce Lactuca sativa var. capitata, and the effects of the organic matter filter cake press, cattle manure, poultry manure and earthworm soil, incorporated in the soil. Twenty two (22) treatments and fours repetitions were applied with each of the two varieties (Great lakes 118 and Pacific), the treatments corresponded to 5, 10, 15 t/ha of the organic matter which were applied to the soil fifteen days before transplantations occured. The results showed an excellent plant vigour and quality after the transplantation. It was also observed a good plant poblation and uniformity. The sustrate filter cake press mixed with botton fly ash presented better results in the field than the other treatments, having the highest crop yield and the best quality. The Great Lakes 118 with this treatment doubled the production of the treatment with soil. With the organic sustrates, the poultry manure 5 t/ha projected better results. The work showed the good behavior of the varity Great Lakes 118 compared to the Pacific. This treatments also improved the chemical caracteristics of the soil, especially increased the organic matter, potassium, phosporus, manganesum and zinc.En el Corregimiento Pavitas, municipio de La Cumbre, en la Finca Santafé, a 1.480 msnm en un suelo de la Asociación Pavas (Aeric Tropaquept) se probó el modelo vaso-sustrato-planta (VSP), en la producción de plántulas de lechuga Batavia L. sativa var. capitata y el efecto en la producción de los compuestos orgánicos, cachaza, lombricompuesto, gallinaza y bovinaza, incorporados al suelo. Los 22 tratamientos con cuatro repeticiones, repartidos en dos variedades (Great Lake 118 y Pacific) correspondieron a dosis (5, 10, 15 t/ha) de las enmiendas orgánicas aplicadas al suelo 15 días antes del trasplante y un tratamiento con el sustrato cachaza-carbonilla. El manejo de las plántulas permitió obtener excelentes resultados en cuanto a calidad, arraigo inmediato y gran uniformidad en la población. La mezcla cachaza-carbonilla superó ampliamente en rendimiento y calidad de las cabezas a los demás tratamientos. Great Lake 118 produjo el doble de lechugas que la siembra en el suelo. Entre las enmiendas orgánicas se obtuvieron muy buenos resultados con 5 t/ha de gallinaza. Great Lake 118 se comportó mejor que Pacifico Además, los tratamientos mejoraron las características químicas del suelo, especialmente el contenido de materia orgánica, potasio, fósforo, magnesio y zinc.

In this study, we explore automated reasoning tools (ART) in geometry education and we argue that these tools are part of a wider, nascent ecosystem for computer-supported geometric reasoning. To provide some context, we set out to summarize the capabilities of ART in GeoGebra (GGb), and we discuss the first research proposals of its use in the classroom. While the design and development of ART have been embraced already by several teams of mathematics researchers and developers, the educational community, which is an essential actor in this ecosystem, has not provided sufficient feedback yet on this new technology. We therefore propose a concrete path for incorporating ART in the classroom. We outline a set of necessary procedures towards this goal, and we include a discussion on the benefits and concerns arising from the use of these automated tools in the mathematical learning process.

Resumen: El dolor de espalda es uno de los síntomas más relacionados con los riesgos de salud ocupacional. Es de alta prevalencia en la población Norteamericana, y afecta principalmente a aquellas personas que, en su trabajo, deben usar la fuerza mecánica. Por consiguiente, es un riesgo laboral para profesionales de medicina intervencionista, como radiólogos, neurorradiólogos y cardiólogos intervencionistas. De hecho, en varios artículos de estudios observacionales este fenómeno se conoce como “enfermedad del disco intervencionista”. Dicha condición está muy relacionada con el equipamiento de protección personal que suele ser de mayor peso, como los delantales de plomo usados para evitar la radiación ionizante, o con entornos de laboratorio de cateterización que promueven posturas ergonómicas inadecuadas. Se ha documentado que, en comparación con otros cirujanos, como los ortopedistas, estos profesionales de la medicina invasiva tienen mayor riesgo de presentar afecciones ortopédicas de la columna vertebral, aunque estos últimos tienen tiempos de procedimientos quirúrgicos más prolongados.Por otra parte, la mayor tasa de incidencia de lesiones axiales en los cardiólogos intervencionistas parece estar relacionada con la combinación del uso de delantal de plomo y los procedimientos de cateterismo.En estudios de prevalencia se ha demostrado que al comparar ortopedistas, reumatólogos y cardiólogos intervencionistas, estos últimos han presentado entre un 49,4 y un 53% de lesiones músculo-esqueléticas.Los métodos para reducir la carga de peso se han centrado en innovaciones basadas en la fabricación de alternativas sin plomo para el blindaje; de igual manera, el uso de protectores móviles apoyados en el piso reduce sustancialmente la exposición de todo el cuerpo.En cuanto a ergonomía, se requieren estudios de innovación con expertos en radiación, médicos y administradores a fin de diseñar una sala de radiología intervencionista adecuada. Abstract: Back pain is one of the symptoms most associated with occupational health risks. It is highly prevalent in the North American population, and mainly affects those people that have to use mechanical effort in their work. It is, therefore, an occupational risk for interventionist medicine personnel, such as radiologists, neuro-radiologists and interventional cardiologists. As such, in several observational studies this phenomenon is known as “interventionist disc”. This condition is closely associated with the personal radiation protection equipment that is usually very heavy. These include the leaded aprons used to protect against ionising radiation, or in catheterisation laboratories that promote inadequate ergonomic postures. There is evidence that, compared to other surgeons such as in orthopaedics, these invasive medicine professionals have a higher risk of spinal column problems, although these latter have longer surgical procedure times.On the other hand, the higher incidence rate of axial injuries in interventional cardiologists seems to be associated with the combination of using a leaded apron and the catheterisation procedures.It has been shown in prevalence studies that compare orthopaedists, rheumatologists, and interventionist cardiologists that these latter had between 49.4% and 53% musculoskeletal lesion.The methods to reduce weight load have been focused on innovations based on the manufacture of lead-free alternatives for shielding. The use of mobile protectors supported on the floor also substantially reduces whole body exposure.As regards ergonomics, new studies are required with experts in radiation, doctors and administrators, with the aim of designing an appropriate interventional radiology room. Palabras clave: Dolor de espalda, Enfermedades profesionales, Cardiólogo intervencionista, Equipo de protección personal, Protección radiológica, Key words: Back pain, Occupational diseases, Interventional cardiologist, Personal protection equipment, Radiation protection

This document introduces, describes and exemplifies the technical features of some recently implemented automated reasoning tools in the dynamic mathematics software GeoGebra. The new tools are based on symbolic computation algorithms, allowing the automatic and rigorous proving and discovery of theorems on constructed geometric figures. Some examples of the use in the classroom of such commands are provided, including one describing how intuitive handling of GeoGebra automated reasoning tools may result in unexpected outputs. In all cases the emphasis is made in the potential utility of these tools as a guiding stick to foster student activities (exploration, reasoning) in the learning of elementary geometry. Moreover, a collection of appendices describing other, more sophisticated, low-level GeoGebra tools (Prove, ProveDetails), as well as instructions on how to obtain the translation of GeoGebra commands into other languages, and details about debugging, are included.

Este trabajo evaluó la condición ambiental de un tramo del Río San Juan por medio del índice de calidad ecológico (ICE) usando como grupo indicador las algas perifíticas. El método determinó un gradiente ambiental a partir de correlaciones entre variables fisicoquímicas y abundancia a través de un análisis de correspondencias canónicas, las puntuaciones obtenidas en cada punto de muestreo se utilizaron en una correlación estandarizada para un modelo de promedios ponderados (WA) que finalmente permitieron estimar el óptimo y la tolerancia de cada taxón. El agrupamiento determinó tres conjuntos, uno de ellos reunió estaciones y períodos con mayores valores medios de sólidos disueltos y ortofosfatos y menores en cuanto a la alcalinidad y ICESJ-Alg, a este grupo se asociaron la estación 2 (Quebrada la Chaparrala) y la estación 5 (Sitio Remolinos), ambos sitios se caracterizan por aguas turbias e intervención antrópica. En contraste, otro grupo tendió a registrar las tendencias contrarias, es decir, tendencia a mayores valores de la alcalinidad y el índice, características de la estación 1 (Charco corazón, sitio caracterizado por aguas claras con reducida intervención antrópica). La clasificación de los sitios ubicados en el tramo del Río usando el ICE explicó que las concentraciones de los sólidos disueltos, la alcalinidad y los ortofosfatos definieron las categorías de estado ecológico, se identificó que a mayores concentraciones de sólidos disueltos y ortofosfatos y a menores concentraciones de la alcalinidad el ICESJ-Alg es menor, es decir la calidad ecológica de las algas perifíticas disminuye. El índice brindó una respuesta objetiva y rigurosa para evaluar en forma numérica la posición de cada una de las estaciones del tramo del Río San Juan basada en la biota y variables fisicoquímicas propias del sistema.

Mauricio Vélez, Luis F Velásquez, Sebastián Rojas, Laura Montoya, Katherine Zuluaga, Kepa BalpardaPontifical Bolivarian University, School of Medicine, Medellín, Antioquia, Colombia Purpose: To report the case of a patient who developed late capsular block syndrome and to review the current literature regarding this complication of phacoemulsification procedures. Methods: The literature was reviewed to summarize the diagnosis, classification, use of diagnostic aids, and the current treatments for this complication.Results: A 69-year-old patient complained of decreased visual acuity 11 months after undergoing phacoemulsification. She was found to have a secondary myopization. Anterior segment ultrabiomicroscopy confirmed the diagnosis of capsular block syndrome. The patient underwent neodymium-doped yttrium aluminum garnet (Nd:YAG) laser posterior capsulotomy, which resulted in complete resolution of her symptoms.Conclusion: Capsular block syndrome is a fairly rare complication of phacoemulsification procedures that, depending primarily on the timing of its occurrence following surgery, can develop into one of the three following possible clinical scenarios: intraoperatory, early postoperatory, and late postoperatory. In this patient, Nd:YAG laser capsulotomy was shown to be a safe and effective treatment option for this type of complication. Keywords: continuous curvilinear capsulorhexis, phacoemulsification, cataract

The use of magnetic vector tomography/laminography has opened a 3D experimental window to access the magnetization at the nanoscale. These methods exploit the dependence of the magnetic contrast in transmission to recover its 3D configuration. However, hundreds of different angular projections are required leading to large measurement times. Here we present a fast method to dramatically reduce the experiment time specific for quasi two-dimensional magnetic systems. The algorithm uses the Beer-Lambert equation in the framework of X-ray transmission microscopy to obtain the 3D magnetic configuration of the sample. It has been demonstrated in permalloy microstructures, reconstructing the magnetization vector field with a reduced number of angular projections obtaining quantitative results. The throughput of the methodology is × 10–× 100 times faster than conventional magnetic vector tomography, making this characterization method of general interest for the community. [ABSTRACT FROM AUTHOR]

AbstractSelf-aligned nanoporous TiO2templates synthesized via dc current electrochemical anodization have been carefully analyzed. The influence of environmental temperature during the anodization, ranging from 2 °C to ambient, on the structure and morphology of the nanoporous oxide formation has been investigated, as well as that of the HF electrolyte chemical composition, its concentration and their mixtures with other acids employed for the anodization. Arrays of self-assembled titania nanopores with inner pores diameter ranging between 50 and 100 nm, wall thickness around 20–60 nm and 300 nm in length, are grown in amorphous phase, vertical to the Ti substrate, parallel aligned to each other and uniformly disordering distributed over all the sample surface. Additional remarks about the photoluminiscence properties of the titania nanoporous templates and the magnetic behavior of the Ni filled nanoporous semiconductor Ti oxide template are also included.

In this paper, we describe an educational experience in the context of the Master's degree that is compulsory in Spain to become a secondary education mathematics teacher. Master's students from two universities in Madrid (Spain) attended lectures that addressed—emphasizing the concourse of a dynamic geometry software package—some historical, didactic and mathematical issues related to linkage mechanisms, such as those arising in the 18th and 19th centuries during the development of the steam engine. Afterwards, participants were asked to provide three different kinds of feedback: (i) working on an assigned group task, (ii) individually answering a questionnaire, and (iii) proposing some classroom activity, imagining it would be addressed to their prospective pupils. All three issues focused on the specific topic of the attended lectures. In the framework of Mason's reflective discourse analysis, the information supplied by the participants has been analyzed. The objective was to explore what they have learned from the experience and what their perception is of the potential interest in linkages as a methodological instrument for their future professional activity as teachers. This analysis is then the basis upon which to reflect on the opportunities (and problems) that this particular bar-joint linkages methodological approach could bring towards providing future mathematics teachers with attractive tools that would contribute to enhancing a STEAM-oriented education. Finally, the students' answers allow us to conclude that the experience was beneficial for these pre-service teachers, both in improving their knowledge on linkages history, mathematics, industrial, technological and artistic applications, and in enhancing the use in the classroom of this very suitable STEAM context. [ABSTRACT FROM AUTHOR]