Resumen El agua superficial (SUP) y subterránea (SUB) interactúan dentro del ciclo hidrológico según las características geomorfológicas y climáticas que configuran el paisaje; por tanto, los impactos sobre cualquiera de estos componentes afectarán inevitablemente la cantidad y/o calidad del otro. En este contexto, se propuso un método simple basado en la ecuación general de balance hídrico, que incorpora el flujo de intercambio SUP-SUB en la estimación de la oferta hídrica total (OHtotal) en una cuenca hidrográfica, a partir de datos hidroclimatológicos e hidrogeológicos mínimos. Este método fue aplicado en la microcuenca de la quebrada La Arenosa-La Margarita (Pereira, Colombia) y se observó que el aporte de flujo subterráneo influye en la estimación de la oferta hídrica. También se analizó que estos resultados son similares a los obtenidos por modelos teóricos ampliamente utilizados en la hidrología tales como el SCS, UNESCO, Tanques agregados, Balance Hídrico de Largo Plazo y Rendimiento Hídrico para la misma zona de estudio. Por lo tanto, se concluyó que el modelo propuesto es viable para su aplicabilidad en microcuencas con poca información de tipo hidrológico e hidrogeológico.

Abstract Surface water (SUP) and groundwater (SUB) interact inside the hydrological cycle according to geomorphologic and climatic characteristics that compose the landscape. Therefore, the impact on any of these compounds will inevitably affect the quantity and/or quality of the other. In this context, a simple method was proposed based on the general water balance equation; which incorporates the exchange flow of superficial and groundwater in the estimate of the total water availability (OHtotal) in a watershed, starting from minimum hydroclimologic and hydrogeologic data. This method was applied to the micro-basin of La Arenosa-La Margarita creek (Pereira, Colombia) and it was noticed that the input of the groundwater flow influences in the estimate of the water availability. Also, it was analyzed that these results are quite similar to the ones obtained by widely used theoretical models used in hydrology; such as the SCS, UNESCO, added tanks, Long-term hydric balance and Hydric Efficiency for the same study area. Thus, it was concluded that the proposed method is viable to be applied in micro-basins with little hydrologic and hydrogeological information.

The entry of sodium and calcium play a key effect on myocyte subjected to cardiac arrest by hyperkalemia. They cause cell swelling, acidosis, consumption of adenosine triphosphate and trigger programmed cell death. Cardiac arrest caused by hypocalcemia maintains intracellular adenosine triphosphate levels, improves diastolic performance and reduces oxygen consumption, which can be translated into better protection to myocyte injury induced by cardiac arrest.

A entrada de sódio e cálcio desempenham efeito chave no miócito submetido à parada cardíaca por hiperpotassemia. Eles provocam edema celular, acidose, consumo de trifosfato de adenosina e desencadeiam processo de morte celular programada. A parada cardíaca provocada por hipocalcemia mantém os níveis intracelulares de trifosfato de adenosina, melhora o rendimento diastólico e reduz o consumo de oxigênio, o que pode ser traduzido em melhor proteção do miócito às lesões provocadas pela parada cardíaca induzida.

Se evaluó una nueva metodología para detectar y cuantificar la formación de acrilamida en las etapas de producción de la panela. Los datos de esta investigación contribuyen al control de calidad de la panela, particularmente en la evaluación del riesgo químico asociado a este producto de uso popular, en beneficio primordial del sector agroalimentario y de la calidad. La técnica de análisis empleada fue la cromatografía líquida de alta eficiencia en fase reversa, y el método de cuantificación empleado fue el estándar externo, para lo cual se construyó una curva de calibración. Se halló que en el jugo de caña no se forma acrilamida, pero a medida que aumenta el tiempo y la temperatura (reacción de Maillard) se evidencia su presencia, encontrándose en el producto final 2.0 mg/kg; se pudo, en consecuencia, establecer la efectividad de la cuantificación por este método analítico; para la verificación y confirmación del contenido de acrilamida, información útil para evaluar la autenticidad del producto final.

A new method for the detection and quantification of acrylamide formation in the production stages of sugar cane was evaluated. This research provides data to help the food industry, particularly in quality control of sugar cane, for chemical risk evaluation associated with this popular product and often used for primary benefit of the quality and food industry. The technique employed was high efficiency liquid chromatography in reverse phase, the quantification method employed was the external standard, for which a calibration curve was constructed. Getting in cane juice, acrylamide formation does not occur, but with increasing time and temperature (Maillard reaction) its presence is evident; found in the final product 2.0 mg/kg, so it can establish the effectiveness of quantification for this analytical method, for verification and confirmation of acrylamide, also contribute useful for evaluation of the authenticity of the final product information.

Introduction: Solutions that cause elective cardiac arrest are constantly evolving, but the ideal compound has not yet been found. The authors compare a new cardioplegic solution with histidine-tryptophan-glutamate (Group 2) and other one with histidine-tryptophan-cetoglutarate (Group 1) in a model of isolated rat heart. Objective: To quantify the fractal dimension and Shannon entropy in rat myocytes subjected to cardioplegia solution using histidine-tryptophan with glutamate in an experimental model, considering the caspase markers, IL-8 and KI-67. Methods: Twenty male Wistar rats were anesthetized and heparinized. The chest was opened, the heart was withdrawn and 40 ml/kg of cardioplegia (with histidine-tryptophan-cetoglutarate or histidine-tryptophan-glutamate solution) was infused. The hearts were kept for 2 hours at 4ºC in the same solution, and thereafter placed in the Langendorff apparatus for 30 min with Ringer-Locke solution. Analyzes were performed for immunohistochemical caspase, IL-8 and KI-67. Results: The fractal dimension and Shannon entropy were not different between groups histidine-tryptophan-glutamate and histidine-tryptophan-acetoglutarate. Conclusion: The amount of information measured by Shannon entropy and the distribution thereof (given by fractal dimension) of the slices treated with histidine-tryptophan-cetoglutarate and histidine-tryptophan-glutamate were not different, showing that the histidine-tryptophan-glutamate solution is as good as histidine-tryptophan-acetoglutarate to preserve myocytes in isolated rat heart.

Introdução: As soluções que provocam parada cardíaca eletiva estão em constante evolução, porém, o composto ideal ainda não foi encontrado. Os autores comparam uma nova solução cardioplégica com histidina-triptofano-glutamato (Grupo 2) com histidina-triptofano-cetoglutarato (Grupo 1) em modelo de coração isolado de rato. Objetivo: Quantificar a dimensão fractal e entropia de Shannon em miócitos de rato submetidos à cardioplegia utilizando solução histidina-triptofano com glutamato em modelo experimental, considerando-se os marcadores caspase, IL-8 e Ki-67. Métodos: Vinte ratos machos de raça Wistar foram anestesiados e heparinizados. O tórax foi aberto, realizado cardiectomia e infundido 40 ml/Kg de solução cardioplégica apropriada. Os corações foram mantidos por 2 horas na mesma solução a 4ºC e, após esse período, colocados em aparato de Langendorff por 30 minutos com solução de Ringer Locke. Foram feitas análises imunohistoquímicas para caspase, IL-8 e KI-67. Resultados: A dimensão fractal e a entropia de Shannon dos corações submetidos à parada cardíaca eletiva nos grupos 1 e 2 não foram diferentes. Conclusão: A quantidade de informações avaliada pela entropia de Shannon e a distribuição das mesmas (dada pela dimensão fractal) nas lâminas de coração de rato submetidas à cardioplegia com solução histidina-triptofano-acetoglutarato ou histidina-triptofano-glutamato não foram diferentes, o que mostra que a solução de histidina-triptofano-glutamato é tão boa quanto a histidina-triptofano-cetoglutarato na preservação dos miócitos em modelo de coração isolado de rato.

The calcium paradox was first mentioned in 1966 by Zimmerman et al. Thereafter gained great interest from the scientific community due to the fact of the absence of calcium ions in heart muscle cells produce damage similar to ischemia-reperfusion. Although not all known mechanisms involved in cellular injury in the calcium paradox intercellular connection maintained only by nexus seems to have a key role in cellular fragmentation. The addition of small concentrations of calcium, calcium channel blockers, and hyponatraemia hypothermia are important to prevent any cellular damage during reperfusion solutions with physiological concentration of calcium.

O paradoxo do cálcio foi pela primeira vez citado em 1966 por Zimmerman et al. A partir daí, ganhou grande interesse por parte da comunidade científica internacional devido ao fato da ausência do íon cálcio produzir na célula muscular cardíaca dano semelhante à lesão de isquemia-reperfusão. Apesar de não serem conhecidos todos os mecanismos envolvidos no processo da lesão celular no paradoxo do cálcio, a conexão intercelular mantida somente pelo nexus parece ter papel chave na fragmentação celular. A adição de pequenas concentrações de cálcio, bloqueadores de canal de cálcio, hiponatremia ou hipotermia são importantes para evitar que haja lesão celular no momento da reperfusão com soluções com concentração fisiológica de cálcio.

Describimos nuestra experiencia en el tratamiento de heridas abdominales postquirúrgicas dehiscentes y contaminadas con exposición de material protésico, mediante terapia de presión negativa con instilación intermitente de soluciones tópicas. Este dispositivo nos permitió el rescate de pacientes pluripatológicos evitando una reintervención compleja de alta morbi-mortalidad y facilitando el cierre de la herida, además con conservación de la malla en la mayor parte de los casos.

The present data reports our experience in the treatment of postsurgical dehiscent and infected abdominal wounds with exposure of prosthetic material with negative pressure therapy with intermittent instillation of topical solutions. This device allowed the rescue of pluripatological patients avoiding a complex resurgery of high morbi-mortality and facilitating wound closure, besides with conservation of the mesh in most of the cases.

The aim of this study was to determine the prevalence of canine Ehrlichiosis among animals treated at the Corozal Veterinary Hospital of the Faculty of Veterinary Medicine, University of Panama, Brazil. The survey was conducted retrospectively with data obtained from January 2004 to December 2009, based on the records of clinical cases of canine ehrlichiosis, confirmed with blood smear, race and demographics data (age, sex and place of origin) of each animal. The results revealed that 10.12% of the treated animals (n = 1452) were positive in the period under review. These animals were of both sexes with a mean age of approximately 3.6 years. The monthly prevalence recorded was 9.98%, with a significantly higher infection rate in 2008 (14.83%). The positive cases were significantly higher in the months of March, May and September and lowest in February, with a noteworthy density of cases equal to or higher than the average from May to October. Breed and place of origin of the animals were identified as risk factors.

Foi determinada a prevalência de Ehrlichiose canina entre animais atendidos no Complexo Hospitalário Veterinário do Corozal da Faculdade de Medicina Veterinária da Universidade de Panamá. O levantamento foi realizado de forma retrospectiva com dados obtidos no período de janeiro de 2004 a dezembro de 2009. Para o trabalho, foram utilizados os registros dos casos clínicos de ehrlichiose canina, confirmados através de esfregaço sanguíneo, a raça e os aspectos demográficos (idade, sexo e local de origem) de cada animal. Os resultados revelaram que 10,12% dos animais atendidos (n = 1.452) mostraram-se positivos para o problema no período em análise. Esses animais eram de ambos os sexos com idade media de aproximadamente 3,6 anos. A prevalência mensal registrada foi de 9,98%, com taxa de infecção significativamente superior em 2008 (14,83%). O número de casos positivos foi significativamente superior nos meses de março, maio e setembro e menor no mês de fevereiro, destacando-se haver densidade de casos igual ou superior à média de maio a outubro. A raça e o local de origem dos animais foram identificados como fatores de risco.

In this paper formulas derived by the author for calculating the pseudo inverse of any matrix are generalized to linear operators in Hilbert space. The pseudo inverse is seldom required unless there are many right side vectors, which become known at differet times. The minimum square solution of functional equations is also presented for a single right-side vector. Some definitions and theorems of functional analysis are included. An application to a simple minimum energy optimal contol problem is presented in detail.

En este artículo se generalizan fórmulas, deducidas por el autor, para el cálculo de la seudo inversa de cualquier matriz, a operadores lineales en espacios de Hilbert. La seudo inversa raramente se necesita a menos que muchos vectores del lado derecho se presenten en diferentes tiempos. La solución de mínimos cuadrados de ecuaciones funcionales se presenta también. Se presenta en detalle una aplicación a la solución de un problema sencillo de control óptimo de mínima energía.

Un evento extremadamente inusual en patología forense es la "expulsión postmortem de un feto" también denominado parto postmortem. El "parto postmortem" se define como la expulsión de un feto muerto tras el fallecimiento de una mujer embarazada cuando el útero materno muestra claros signos de putrefacción. Se considera que los gases generados en la fase enfisematosa de la putrefacción cadavérica dentro de la cavidad abdominal pueden prolapsar el útero y causar la expulsión total o parcial del feto. Presentamos el caso de una mujer embarazada de siete meses que desapareció y fue hallada muerta varios días más tarde en avanzado estado de putrefacción. Antes de practicar la autopsia se procedió a retirar la ropa interior y se encontró el feto fuera de la cavidad pélvica. Al mismo tiempo se realiza una revisión histórica del tema.

An extremely unusual event in forensic pathology is the postmortem fetal extrusion or "coffin birth". It is defined as the expulsion of a dead fetus after the death of a pregnant woman when the maternal uterus shows signs of putrefaction. It is considered that the gases generated during the emphysematous phase of the cadaveric putrefaction may distend the uterus causing partial or total fetal extrusion. We present the case of a seven month pregnant woman who disappeared and was found dead some days later in a state of advanced putrefaction. The fetus was discovered inside the woman’s underwear at the moment of undressing the body before autopsy. At the same time, an historical review of the issue is carried out.

The calculation of the pseudo inverse of a matrix is intimately related to the singular value decomposition which applies to any matrix be it singular or not and square or not. The matrices involved in the singular value decomposition of a matrix A are formed with the orthogonal eigen vectors of the symmetric matrices A T A and AA T associated with their nonzero eigenvalues which forms a diagonal matrix. If instead of using the eigenvectors, which are difficult to calculate, we use any set of vectors that span the same spaces, which are easier to obtain, we can get simpler expressions for calculating the pseudoinverse, although the diagonal matrix of eigenvalues is filled. All numerical work to obtain the pseudo inverse whose components are rational numbers when the original matrix is also rational reduces to elementary row operations. We can, thus, generalize the least-squares/ minimum-length normal equations for full-rank matrices and solve said problems and obtain the pseudo inverse in terms of A and A T. without solving any eigen problems or factoring matrices.

El cálculo de la seudo inversa de una matriz está íntimamente relacionado con la descomposición de valores singulares aplicable a cualquier matriz, singular o no y cuadrada o no. Las matrices involucradas en la descomposición en valores singulares de una matriz A están formadas con los vectores característicos ortogonales de las matrices simétricas A T A y AA T asociados con los valores característicos no nulos, los cuales forman una matriz diagonal. Si, en lugar de usar los vectores característicos, los cuales son difíciles de calcular, se usa cualquier conjunto de vectores que generan los mismos espacios, que son más fáciles de obtener, se pueden obtener expresiones más simples para el cálculo de la seudo inversa, no obstante que la matriz diagonal se llena. Todo el trabajo numérico se reduce a operaciones elementales de filas obteniéndose seudo inversas con componentes racionales cuando la matriz original tiene componentes racionales. De esta manera podemos generalizar las ecuaciones normales de mínimos cuadrados / longitud mínima de matrices de rango completo, resolver el problema y obtener la seudo inversa en términos de A y A T sin resolver problemas de vectores característicos o factorizar matrices.

In this paper, a family of simple formulas for the calculation of the pseudo inverse of a rectangular matrix of less than maximum rank is derived using linear vector space methods. The principal result is that the pseudo inverse A+ of a matrix A can be calculated as A+ = Q(P T AQ)-1P T, where P and Q are rectangular matrices whose r columns are vectors that form a basis for the spaces spanned by the columns and rows, respectively, of matrix A. This leaves the user the liberty to choose the basis to take into consideration other questions such as amount of work needed and ill-conditioning of the matrix that has to be inverted. The formulas are particularized for rectangular matrices that have maximum rank and for the trivial case in which the original matrix is non-singular. Illustrative numerical examples are worked out for several choices of basis vectors and the results are compared with those provided by the program Mathematics through its function PseudoInverse[A].

En este artículo se deduce una familia de fórmulas simples para el cálculo de la seudo inversa de una matriz rectangular de rango menor que el máximo del número de filas y el número de columnas utilizando métodos de espacios vectoriales lineales. El resultado principal es que la seudo inversa A+ de una matriz A se puede calcular con la fórmula A+ = Q(P T AQ)-1P T, donde P y Q son matrices rectangulares cuyas r columnas ( r es el rango de la matriz A) son vectores que forman una base para los espacios generados por las columnas y filas respectivamente de la matriz A. Esto le deja al usuario la libertad de escoger la base y tomar en consideración otras cuestiones como la cantidad de trabajo requerida y el mal condicionamiento de la matriz A. Las fórmulas se particularizan para matrices rectangulares que tienen máximo rango y para el caso trivial en que la matriz original es no-singular. Se presentan las soluciones de ejemplos numéricos ilustrativos para varias selecciones de vectores base, y los resultados se comparan con los que proporciona el programa Mathematica a través de su función PseudoInverse[A].

With the current interest in teaching problem-solving, it is important that the example problems that are presented to students have important educational value. Many mathematical puzzles, while requiring little specific background to be posed and remembered, are paradigms of important practical problems. If the teacher chooses the right puzzles, he/she not only will have motivated the student's interest, but will also have the opportunity of teaching powerful ideas that can be applied in a multitude of similar problems. Moreover the teacher will also be able to teach the corresponding solution algorithms and the way computers can be used as tools in problem-solving. The article presents these topics through an extensive example based on a well-known, apparently simple, wine-pouring puzzle that is intimately related to the concepts of state, shortest-routes and many management, engineering and industrial problems.

In this paper the Logo environment is applied to several original computerized learning projects, each of a very different nature: one for learning geometry generating numerous instances for verifying the results of a little known theorem of plane geometry, a second for learning the basics of the physical foundations of music through the construction, using the keyboard of the computer, of a little piano, and a third one to learn some aspects of Spanish grammar involving the conjugation of regular and irregular verbs. The projects were carefully selected to illustrate a wide range of possibilities and the flexibility of the Logo language and power of its instruction set and adaptive data structure. After introducing the main ideas of the Logo educational philosophy, a short introduction to the language is given followed by an introduction to the concept of a microworld. Next the idea of a computerized learning project is explained and the three projects mentioned above are presented. Complete listings of simple programs in Logo Writer are included together with some ideas for extending the projects in different directions. The projects presented in the paper are of a slightly more advanced nature than what usually appears in books on Logo. The paper is sprinkled with learning ideas that can be tried with groups of youngsters.

En este artículo se aplica el ambiente Logo a varios proyectos computarizados de aprendizaje, cada uno de una naturaleza muy diferente: uno para aprender geometría generando casos particulares de los resultados de un teorema poco conocido de geometría plana, un segundo para aprender los fundamentos de la música a través de la construcción, utilizando el teclado de la computadora, de un pianito y un tercero para aprender algunos aspectos de la gramática española relativos a la conjugación de verbos regulares e irregulares. Se seleccionaron cuidadosamente los proyectos que se incluyen para ilustrar la gama amplia de posbilidades y la flexibilidad del lenguaje Logo, así como el poderío de su conjunto de instrucciones y de su estructura de datos adaptable. Después de introducir las principales ideas de la filosofía educativa Logo, se da una breve introducción al lenguaje seguida de una introducción al concepto de micromundo. A continuación se explica la idea de un proyecto computarizado de aprendizaje y se presentan los tres proyectos mencionados. Se incluyen listados completos de programas sencillos en Logo Writer junto con algunas ideas para extenderlos proyectos en diferentes direcciones. Los proyectos presentados en el artículo son de una naturaleza ligeramente más avanzada que la que normalmente aparece en los libros sobre Logo. El artículo está salpicado con ideas de aprendizaje que se pueden ensayar con grupos de jóvenes