Search

A complete simulcast on digital TV (DTV) can be complex to implement in some scenarios, such as when the network bandwidth has many limitations. A common solution in such scenarios is to limit the number of duplicate programmes in the simulcast to a minimum. However, this practice slows down the migration to a new generation. This article analyses the causes of this delay and proposes a technique to improve the efficiency of the simulcast. Focusing on the migration from MPEG-2 SD to H.264 HD broadcasts in DVB-T networks, the article presents an efficient solution that can accelerate the transition period.

This article presents the results of the analysis of the studies of the operation of a modified IEEE-13 distribution feeder, which was built to scale in the laboratory at Universidad del Norte. In this article, we show the cases of the operating regimes of the modified IEEE-13, before the different levels of wind energy penetration. The modified IEEE-13 distribution feeder was built taking into account that each of the scaled modules and their generator-load will work under the conditions of the Universidad del Norte laboratory. An experimental methodology was used to compare the results obtained in the actual scaled model with the results of the simulations in specialized programs. The conclusions of the article show the wind energy that can be injected into an electrical system with conventional power generation so that it can maintain its operation complying with the current regulatory framework.

Accurate temperature measurements are needed to monitor and reduce energy use and greenhouse gas emissions in building, industrial, and other processes. This paper describes a temperature sensor instrument, named TempSense, developed for classroom demonstrations of thermal phenomena. The instrument can monitor, record, and visualize data from multiple temperature sensors using a K-type amplifier and thermocouples. It has an accuracy of ±2 deg C from -200 to +700 deg C and an accuracy of ±6 deg C from –270 to +1372 deg C. The instrument uses a USB bridge and the Python language to interface with open-source thermocouple amplifiers without the need for byte-level programming. Its design allows novice experimenters to inspect the build and operation and even customize it to their needs. TempSense can be extended via Python libraries to provide internet communication, visualization, and analysis.

In a broad sense, Machine Learning (ML) is the performance optimization in a certain task through computational means, following a certain criterion and using referential data and/or past results from previous iterations. ML is a subset of Artificial Intelligence (AI) and has attracted a substantial amount of research during the last decades. This blooming subject led to the statement of different definitions for classifications, criteria, algorithms and so on. This paper summarizes these different definitions and proposes a homologation between them, providing an unified vision for each definition.

Supplying electricity to populations without full access requires cost-effective, distributed sources of electricity generation. Diesel generators are a popular electricity source because of their low capital costs, but they can have high operating costs. Little data exist regarding the real-world behavior and operating costs of installed diesel microgrids. We report on the energy delivery and fuel consumption in three diesel microgrids in the Lake Sentani region of Papua, Indonesia. We found that these generators are operated below their capacity and that the fuel used per unit of electricity delivered can be over five times greater than expected based on published values. These estimations of specific fuel consumption suggest that nominally electrified areas are paying high costs for poor reliability, but cost-effective improvements are possible.

The human respiratory syncytial virus (hRSV) is the main etiologic agent of severe lower respiratory tract infections that affect young children throughout the world, associated with significant morbidity and mortality, becoming a serious public health problem globally. Up to date, no licensed vaccines are available to prevent severe hRSV-induced disease, and the generation of safe-effective vaccines has been a challenging task, requiring constant biomedical research aimed to overcome this ailment. Among the difficulties presented by the study of this pathogen, it arises the fact that there is no single animal model that resembles all aspects of the human pathology, which is due to the specificity that this pathogen has for the human host. Thus, for the study of hRSV, different animal models might be employed, depending on the goal of the study. Of all the existing models, the murine model has been the most frequent model of choice for biomedical studies worldwide and has been of great importance at contributing to the development and understanding of vaccines and therapies against hRSV. The most notable use of the murine model is that it is very useful as a first approach in the development of vaccines or therapies such as monoclonal antibodies, suggesting in this way the direction that research could have in other preclinical models that have higher maintenance costs and more complex requirements in its management. However, several additional different models for studying hRSV, such as other rodents, mustelids, ruminants, and non-human primates, have been explored, offering advantages over the murine model. In this review, we discuss the various applications of animal models to the study of hRSV-induced disease and the advantages and disadvantages of each model, highlighting the potential of each model to elucidate different features of the pathology caused by the hRSV infection.

Image-based metric measurement has been widely used in industry for the past decade due to the recent advancement in processing power and also the unobtrusiveness of this method. In particular, this method is gaining attention in the realm of real-time detection, classification, and inspection of vehicles used in intelligent transportation systems for law enforcement. These systems have proven themselves as a plausible competition to under-the-pavement loop sensors. In this paper, we analyze the sensitivity in image-based metric measurement for vehicles’ wheel base estimation. Results lead to a simple guideline for calculating the optimal configuration yielding the highest resolution and accuracy. More specifically, we address the sensitivity of the metric measurements to the depth (i.e., the distance between the camera and the vehicle) and also internal calibration parameters of the visible-light imaging system (i.e., camera’s intrinsic parameters). We assumed a pinhole projection model with added barrel effect, aka, lens distortion. A 3D video simulation was developed and used as a Hardware-in-the-Loop (HIL) testbed for verification and validation purposes. Through a simulated environment, three case studies were conducted to verify and validate theoretical data from which we concluded that the error due lens distortion accounted for 0.014% of the total error whereas the uncertainty in the depth of the vehicle with respect to the location of the camera accounted for 99.8% of the total error.

BACKGROUND Cadherin-17 (intestinal peptide-associated transporter) and SATB2 (SATB homeobox 2) immunoexpression has recently been described in surgical pathology to have value in establishing the colorectal origin of metastatic adenocarcinoma. However, to the authors' knowledge, the role of these markers in metastatic colorectal adenocarcinoma (MCA) in cytology has not been addressed to date. In the current study, the authors evaluated the contribution of cadherin-17 and SATB2 to the diagnosis of MCA in cytology specimens and compared these two novel markers with the standard gastrointestinal immunohistochemistry panel in an attempt to identify the optimal panel. METHODS A total of 43 MCA cytology cases and 68 metastatic noncolorectal adenocarcinoma (non-MCA) cytology controls were stained for SATB2; cadherin-17; and the standard panel of cytokeratin (CK) 7, CK20, and Caudal-Type Homeobox Transcription Factor 2 (CDX2). Staining intensity and percentage of positive cells were recorded. Sensitivity and specificity values for immunostains individually and in combination were computed and compared. RESULTS Despite specificities of 83.8% and 91.2%, respectively, for cadherin-17 and SATB2, when critically examining the new immunostains together with the standard panel, there was no significant difference noted with regard to prediction of MCA (vs non-MCA) compared with the standard panel alone (P

This article estimates the impact of cities on the economic development of rural communities in Chile, following a market access approach. The effect of the proximity to cities on the development of rural communities is analyzed by estimating the impact of market access on the population, and farm and non-farm employment of rural communities. Using population censuses and remote sensing data, we find, in our preferred estimations, that a 10% higher market access induced a 10%–14% increase in the population of rural communities. Additionally, higher positive elasticities are found in the non-farm sector rather than in the agricultural one. These results widely support the hypothesis of structural change and the diversification of the rural economy for rural communities with better access to markets. Notwithstanding, the evidence also suggests that the farm sector took important advantages from market access in places with better agro-ecological conditions.

Commercialy available (UAVs) rely on the Global Positioning System (GPS) to define their flight plan, while assuming an obstacle-free environment. The work presented on this article aims to set the foundation towards an autonomous airborne agent, capable of locating itself by means of computer vision, modeling its environment, planning and executing a three dimensional trajectory. On the first stage of development we solved the localization problem using artificial markers and tested a PID controller to make the vehicle follows a given trajectory (a lemniscate); as results, we show flight data captured during real flights. This development would facilitate the integration of far more complex flight behaviors than GPS only guided flight plans.

For many isolated regions in the developing world micro-grids which combine photovoltaic electricity generation and battery storage may represent the most reliable and least expensive form of energy service. Due to climate induced solar resource variations, achieving high reliability levels necessitates excess generation and storage capacity which can significantly increase the end consumer cost of energy. Due to severe financial limitations, many consumers in the developing world may prefer cost versus reliability trade-offs, as long as their basic energy needs are met. Defining reliability as the percent of electricity demand a grid can deliver, we utilize a time series energy balance algorithm at hourly resolution to create cost versus reliability curves of micro-grid performance. We then propose a micro-grid sizing strategy which enables designers with knowledge of local energy needs to determine the acceptability of potential micro-grids. Our strategy relies on visualizing simulation data at increasing levels of temporal resolution to determine where energy shortfalls occur and if they interfere with high priority energy demand. A case study is presented which utilizes the proposed methods. Results suggest that the methodology has the potential to reduce the cost of service while maintaining acceptable consumer reliability.

This paper describes a model to simulate the decision-making process of consumers that adopts technology within a dynamic social network. The proposed model use theories and tools from the psychology of consumer behavior, social networks and complex dynamical systems like the Consumat framework and fuzzy logic. The model has been adjusted using real data, tested with the automobile market and it can recreate trends like those described in the world market.

We present an integrated palaeoecological and archaeobotanical study of pre-Columbian raised-field agriculture in the Llanos de Moxos, a vast seasonally inundated forest–savanna mosaic in the Bolivian Amazon. Phytoliths from excavated raised-field soil units, together with pollen and charcoal in sediment cores from two oxbow lakes, were analysed to provide a history of land use and agriculture at the El Cerro raised-field site. The construction of raised fields involved the removal of savanna trees, and gallery forest was cleared from the area by ad 310. Despite the low fertility of Llanos de Moxos soils, we determined that pre-Columbian raised-field agriculture sufficiently improved soil conditions for maize cultivation. Fire was used as a common management practice until ad 1300, at which point, the land-use strategy shifted towards less frequent burning of savannas and raised fields. Alongside a reduction in the use of fire, sweet potato cultivation and the exploitation of Inga fruits formed part of a mixed resource strategy from ad 1300 to 1450. The pre-Columbian impact on the landscape began to lessen around ad 1450, as shown by an increase in savanna trees and gallery forest. Although agriculture at the site began to decline prior to European arrival, the abandonment of raised fields was protracted, with evidence of sweet potato cultivation occurring as late as ad 1800.

This article describes the design of a model to identify the relevant factors in the decision-making process of consumers that adopt technology within a dynamic social network. The proposed model includes specific theories and tools from the psychology of consumer behavior, social networks, and complex dynamical systems. The model has been developed to work with the mobile smartphone market and was able to describe trends similar to those described in the real world market. COL0031216

In order to change the control approach that commercially available Unmanned Aerial Vehicles (UAVs) use to execute a flight plan, which is based on the Global Positioning System (GPS) and assuming an obstacle-free environment, we propose a hierarchical multi-layered control system that permits to a UAV to define the flight plan during flight and locate itself by other means than GPS. The work presented on this article aims to set the foundation towards an autonomous airborne agent, capable of locating itself with the aid of computer vision, model its environment and plan and execute a three dimensional trajectory. On the current stage of development we locate the vehicle using a board of artificial markers, the flight plan to execute was defined as either a cubic spline or a Lemniscate. As results, we present the resultant flight data when the proposed control architecture drives the vehicle autonomously.

When a flash of light precedes a static line segment, an illusory motion sensation is observed with the line propagating away from the flash's location towards the opposite side (Hikosaka et al. in Vision Res 33:1219-1240, 1993). Here we report that a similar illusory motion percept can be triggered by a non-consciously perceived flash. Observers reported illusory line motion (ILM) arising from the flash's location when a stationary line was presented and the flash was not detected. The results imply that the line motion illusion does not depend on conscious awareness of the flash and suggest that processing of unconscious information can modulate the responses of the neural mechanisms involved in motion perception.

Many UAV applications rely on a ground-based computer for accomplishing all processing tasks and the power consumed by such systems are a major roadblock when it comes to portability. In this paper we present an efficient and practical human-machine interface with an unmanned aerial vehicle (UAV). One of the main goals of the proposed interface is to be ubiquitous, so we moved all computational load to a mobile device running Android. Through this interface, the UAV responds to both movement and body gestures of the user; moreover, all processing tasks are done efficiently in the mobile device. We describe how we tracked the user throughout the video stream, which techniques we used and how we implemented them in our mobile platform for achieving a good level of performance.

A common problem in the field of digital television is the transition to new encoding formats. The incompatibility between new and old codecs requires a simulcast over a transition period. In some scenarios — particularly when using terrestrial broadcasts — this simulcast represents a significant waste of bandwidth and raises many problems. This article explores the possibility of share audio streams between programs within the same simulcast and presents a technique to reduce the bandwidth required using the ASC (Audio Sharing Compactor). This solution has been validated through the implementation of a demonstrator capable of processing a Transport Stream in realtime before send it to the modulator transmitter.

A variety of surgical procedures is used to correct complete rectal prolapse (RP). We analysed the immediate and long-term results of the Lomas-Cooperman technique in the management of symptomatic RP in elderly patients with severe concomitant diseases.Across a 13-year period, all patients with RP having undergone surgery with this procedure were retrospectively evaluated. The technique consisted in placing a triply folded piece of polypropylene mesh encircling the anal canal through a perineal approach.A total of 22 patients (20 female) with a mean age of 84 years (range, 72-93 years) with severe concomitant pathologies were assessed. Four patients were classified as ASA II and 18 as ASA III. Mean Karnofsky score was 50%, ranging between 40% and 60%. All patients were operated on under regional anaesthesia without incidents. Mean operative time was 35 min(range, 20-60 min) and mean hospital stay was 4.5 days (range, 2-17 days). The most common immediate postoperative complication was urinary tract infection, found in 18% of the cases. Mean follow-up was 32 months (range, 4-84 months). During follow-up, 4 cases (18%) of mesh exteriorisation were detected, requiring mesh trimming at the outpatient clinic. Rectal prolapse recurred in 2 patients; one of them was managed with a new cerclage reaching a satisfactory outcome. Thus, by intention-to-treat basis, the recurrence rate was 4.5%. Constipation was resolved in three out of 4 patients, but in 18% of the cases late faecal impact was recorded. Mean preoperative incontinence score improved from 5.1+/-0.62 to 3.4+/-1.61 (p0.0001) after surgery.Anal cerclage with the Lomas-Cooperman technique constitutes a simple and reproducible surgical technique with an acceptable morbidity and recurrence rate in high-risk elderly patients with RP.

Background Indications for and the prognosis of posterior pelvic exenteration (PPE) in rectal cancer patients are not clearly defined. The aim of this study was to analyse the indications, complications and long-term results of PPE in patients with primary rectal cancer. Methods A retrospective review included patient demographics, tumour and treatment variables, and morbidity, recurrence, and survival statistics. These results were compared with a group of female patients who underwent standard resection for primary rectal cancer in the same period (non PPE group). Results The series included 30 women with an average age of 56.7 years (range 22–78). Tumour location was recorded in three cases in the upper rectum, 13 cases in the medium rectum and 14 cases in the lower rectum. A sphincter-preserving procedure was performed in 70% of the patients. Mean operative time was 4.2 h (range 2–7.5 h). Overall major morbidity rate in this series was 50% and mean hospital stay was 19.7 days (range 9–60 days). There was no hospital mortality. Pathological reports showed direct invasion of uterus, vagina or rectovaginal septum in 19 cases, involvement of perirectal tissue in 25 cases and positive lymph nodes in 18 cases. Comparison between PPE and non PPE groups showed no differences in mean tumour diameter, histological grade and tumour stage, but patients in the first group were younger. Although low tumours were seen more frequently in the PPE group (P = 0.003), the rate of sphincter-preserving procedure was comparable in both groups. Operative time was longer (P = 0.04) and morbidity was higher (P = 0.0058) in the PPE group. Local recurrence with or without distant metastases for the whole series was 30%. Five-year survival rate for patients who underwent curative resections (TNM I–III) was 48% in the PPE group vs 62% in the non PPE group (P = 0.09). Conclusions In the present series, PPE prolonged operative time, increased postoperative complications and showed a trend toward poor prognosis in recurrence and survival. However, PPE offers the only hope for cure to patients with a primary rectal cancer that is adherent or invades reproductive organs.

Langerhan’s cell histiocytosis (LCH) results from the proliferation of immunophenotypically and functionally immature, morphologically rounded Langerhan’s cells along with eosinophils, macrophages, lymphocytes, and, commonly, multinucleated giant cells. Here we report a case in a 6-year-old boy of differential diagnoses including dermatopathic lymphadenitis (DL), parasitic infection, Kimura’s disease, hypersensitivity reactions, cat-scratch disease, sinus histiocytosis with massive lymphadenopathy (SHML), hyperplasic lymph nodes, and lymphoma.

1.3 Billion people will remain without electricity without significant investment in new energy services. The IEA shows that about half of these services need to be distributed energy to reach those beyond the grid. Current investment focuses on centralized power plants and grid expansion. In the absence of public funding, the unelectrified rural populations must rely on private financing. In this paper, I compare the financial returns from watt-scale consumer products for lighting and mobile phone charging and the available financing for consumers from microfinancing. A comparison of the avoided cost in kerosene or phone charging and the monthly payment for a product shows that microfinance loan payments often exceed the avoided cost. Many customers are not able to tolerate these higher recurring payments even though in the future they will have no payments. In the developed world, innovators create instruments that eliminate upfront costs for energy services and immediately reduce consumer energy expenses. Equivalent innovation in this space could speed adoption of these technologies in the developing world as well.

Astrocytomas are the most common type of adult primary central nervous system neoplasms. The World Health Organization (WHO) histologically classifies astrocytomas into four malignancy grades spann...

Reaching unelectrified populations in the developing world with distributed solar requires agressive cost optimization of generation and storage. Conventional solar generation architectures using photovoltaic panels, sealed lead acid batteries, and inverters show room for cost improvement. Using data collected from photovoltaic microgrid users and simulations we demonstrate potential cost reductions using alternate technologies and architectures. Reducing losses from power conversion could lower wholesale energy costs by 20\% while improved battery chemistries could lower costs by up to 50\%.

In this paper we describe the motivations and design process for our open-source, low-power, and high-accuracy AC power meters suitable for several different off-grid metering applications. The described metering and switching hardware is more power efficient than off-the-shelf systems with equivalent capability while being able to measure much smaller loads accurately. The metering system we've developed is suitable for monitoring up to a collection of 20 circuits each drawing power as low as 1W up to 500W as is often found in a rural microgrid setting. Created with modularity in mind, the software and hardware design can easily be modified to be used as part of a home-solar power system, an AC micro-grid, or as a meter for each load in a room. The designs and source code will be made publicly available in August of 2012.

This paper demonstrates a model for electricity delivery and revenue collection in a rural context with the potential to increase the reliability of service delivery and lower operating costs compared to traditional fixed monthly fee utilities. The microutility in this paper provides power on a pre-paid basis similar to the way cellular phone air-time is sold. This system uses Short Message Service (SMS) messages sent over the Global System for Mobile Communications (GSM) networks for communication allowing installation in any place within reach of a GSM tower. Several of these individual microutilities are monitored and administered via a central server. These consumers in these systems are using modest amounts of power consistent with lighting usage. Some customers are are unable to maintain positive account credit suggesting a benefit to the prepaid approach. These microutilities are currently installed and have been providing power to approximately 170 households in Mali and 38 households in Uganda beginning in April--August of 2011.

To compare the extent to which 7 different radiotherapy planning techniques for mediastinal lung targets reduces the lung volume receiving low doses of radiation. Thirteen non-small cell lung cancer patients with targets, including the mediastinal nodes, were identified. Treatment plans were generated to both 60- and 74-Gy prescription doses using 7 different planning techniques: conformal, hybrid conformal/intensity-modulated radiation treatment (IMRT), 7 equidistant IMRT beams, 2 restricted beam IMRT plans, a full (360°) modulated arc, and a restricted modulated arc plan. All plans were optimized to reduce total lung V5, V10, and V20 volumes, while meeting normal tissue and target coverage constraints. The mean values for the 13 patients are calculated for V5, V10, V20, V(ave), V0-20, and mean lung dose (MLD) lung parameters. For the 74-Gy prescription dose, the mean lung V10 was 42.7, 43.6, 48.2, 56.6, 57, 55.8, and 54.1% for the restricted ±36° IMRT, restricted modulated arc, restricted ±45° IMRT, full modulated arc, hybrid conformal/IMRT, equidistant IMRT, and conformal plans, respectively. A similar lung sparing hierarchy was found for the 60-Gy prescription dose. For the treatment of central lung targets, the ±36° restricted IMRT and restricted modulated arc planning techniques are superior in lowering the lung volume treated to low dose, as well as in minimizing MLD, followed by the ±45° restricted IMRT plan. All planning techniques that allow the use of lateral or lateral/oblique beams result in spreading the low dose over a higher lung volume. The area under the lung dose-volume histogram curve below 20 Gy, V0-20, is proposed as an alternative to individual V(dose) parameters, both as a measure of lung sparing and as a parameter to be minimized during IMRT optimization.

We investigated the effects of orientation angle on the adhesion of single gecko setae using dual-axis microelectromechanical systems force sensors to simultaneously detect normal and shear force components. Adhesion was highly sensitive to the pitch angle between the substrate and the seta's stalk. Maximum lateral adhesive force was observed with the stalk parallel to the substrate, and adhesion decreased smoothly with increasing pitch. The roll orientation angle only needed to be roughly correct with the spatular tuft of the seta oriented grossly towards the substrate for high adhesion. Also, detailed measurements were made to control for the effect of normal preload forces. Higher normal preload forces caused modest enhancement of the observed lateral adhesive force, provided that adequate contact was made between the seta and the substrate. These results should be useful in the design and manufacture of gecko-inspired synthetic adhesives with anisotropic properties, an area of substantial recent research efforts.

Antecedentes: El tratamiento del cancer de recto bajo localmente avanzado ha cambiado en la ultima decada hacia la neoadyuvancia con radio quimioterapia (RQT) preoperatoria. Objetivo: Dar a conocer los resultados de una serie prospectiva de casos tratados con RQT preoperatoria mas cirugia radical con reseccion total del mesorrecto. Pacientes y Metodo: se incluye los pacientes con un cancer de recto medio e inferior localmente avanzado (T3-T4 y/o N+) tratados con intencion curativa con radioterapia mas 5-FU con leucovorina. Se detalla el impacto de la RQT en la pieza operatoria comparado con una serie similar sin radioterapia previa. Resultados: Se trata de 76 pacientes (51,3% mujeres) con un promedio etario de 61,9 anos (extremos 28-84). El tiempo de hospitalizacion promedio fue 12,55 dias (DE: 7,19; extremos 4-35), la morbilidad global de la serie fue 37%, no hubo mortalidad operatoria. El efecto del downstaging fue mas marcado en el factor T que en el compromiso linfonodal y en el 21% de los casos se logro una respuesta patologica completa (RPC) o casi completa (RP), sin recidiva en este subgrupo luego de un seguimiento promedio de 59 meses. Conclusion: En esta serie la RQT preoperatoria no aumenta la morbilidad perioperatoria, tiene un impacto marcado en el downstaging patologico y la RPC o RP casi completa se asocia positivamente con la sobrevida a largo plazo.

Antecedentes: La mortalidad por cáncer de colon (CC) se ha duplicado en Chile en los últimos 15 años. El objetivo es analizar los resultados inmediatos y alejados del tratamiento quirúrgico del CC en un hospital público docente. Pacientes y Método: Se incluyen todos los pacientes intervenidos en forma electiva por un CC entre 1991 y 2007. Los pacientes fueron etapificados según el TNM 2002. Los pacientes estadios I a III con R0 son considerados como cirugía con intención curativa. Las curvas de sobrevida fueron estimadas según el método de Kaplan-Meier, las que se comparan con el test log-rank. Para determinar los factores pronósticos más relevantes en el análisis multivariado se utilizó el modelo de regresión de Cox. Resultados: Se trata de 439 pacientes, 55% mujeres, con una edad promedio de 67 años (extremos 22-92). La resecabilidad fue de 86%, el 25% de los casos estaba en estadio IV, la morbilidad fue 21%, la tasa de reoperaciones fue 4% y la mortalidad 1%. La sobrevida global de los estadios I a III fue 82% a 10 años, con una clara inflexión negativa de las curvas a partir del estadio IIIB. El CEA preoperatorio, la permeación vascular, el número de ganglios positivos y la quimioterapia aparecen como factores pronósticos relevantes. Al introducir el TNM en el modelo, la permeación vascular y el índice ganglionar conservan la significancia estadística. Conclusión: La cirugía resectiva del CC puede efectuarse con bajos índices de mortalidad. El índice ganglionar junto al TNM puede ser un factor pronóstico relevante en la toma de decisiones terapéuticas sobre adyuvancia en los pacientes en estadio III.

Antecedentes: El objetivo de este estudio es analizar los resultados del tratamiento quirúrgico de la Fístula Coló Vesical (FCV) de origen diverticular, los que se comparan con la enfermedad diverticular no fistulizada. Pacientes y Método: Análisis retrospectivo de todos los pacientes intervenidos por una FCV de origen diverticular en forma consecutiva. Resultados: De un total de 141 pacientes resecados por una enfermedad diverticular del colon sigmoides, la indicación quirúrgica en 27 (19,3%) fue la presencia de una fístula, de las cuales 18 corresponden a una FCV. El grupo con FCV tiene predominio de hombres (p = 0,0001), más joven (p = 0,027) y con mayor incidencia de enfermedades asociadas (p = 0,0001). La neumaturia se presentó en el 83% y la fecaluria en el 56%. En dos tercios de los casos la FCV se estableció en ausencia de una crisis diverticular previa. El estudio más relevante para demostrar la presencia de una FCV fue la tomografía computada (80%), que se complementa con el enema balitado y la cistoscopia. La resección con anastomosis inmediata, más simple sutura de la vejiga fue el procedimiento empleado en el 94% de los pacientes, sin secuelas ni casos de recidiva, con un seguimiento global promedio de 74,2 meses (extremos 12-158). No hubo reoperaciones ni mortalidad operatoria. Conclusiones: la FCV de origen diverticular es una condición patológica poco frecuente que afecta a pacientes varones en la séptima década de la vida, con múltiples enfermedades asociadas y que frecuentemente se instala en forma silenciosa. La resección primaria es el tratamiento de elección con buenos resultados a largo plazo.

The creation of animated productions is a labour intensive process. Whether the end result is a large-budget motion picture, or a small-scale internet production, there is invariably a large amount of time spent in creating the timeline, arranging assets, previewing and editing. This iterative process is necessary in large-scale productions but can become repetitive and frustrating when the end result is a small production that may have similar elements to previous work. We present a workflow system and framework that are able to both greatly facilitate animated programme production and introduce an element of procedural generation. We further present the Programme Editor, an application designed to be a powerful front end for the framework. The principal contribution of this work is the creation of an XML-based scripting engine that can be used to create an animated production. This permits several techniques, tools and workflows to interchange information, allows rapid incorporation of further tools, and furthermore facilitates the complete automatisation of the production process.

Antecedentes: Se ha debatido si la reseccion paliativa del tumor primario afecta la sobrevida en pacientes con un cancer colorrectal metastasico. El objetivo de este estudio es evaluar esta hipotesis analizando por separado los tumores de colon y de recto. Pacientes y Metodo: Se estudia los pacientes en Estadio IV segun el TNM 2002. Se analiza una serie de variables demograficas e histopatologicas por separado, asi como la morbilidad operatoria y el tiempo de hospitalizacion. Se distingue tres tipos de patron metastasico dentro del estadio IV. El analisis de la sobrevida se realizo mediante el metodo de Kaplan-Meier y para establecer diferencias entre las curvas se utilizo el test log-rank. Resultados: Se trata de 96 pacientes con cancer de colon y 81 con cancer de recto en estadio IV, sin diferencias significativas en cuanto a ASA, tamano tumoral, porcentaje de tumores indiferenciados, relacion entre tumores T3/T4 y CEA preoperatorio, con predominio del patron localmente avanzado en los tumores de recto (p = 0,04). Hubo un 44% de resecciones paliativas en colon y en recto, sin diferencias en la morbilidad (18%) ni la mortalidad operatoria (1%). El promedio de sobrevida en los pacientes de colon sometidos a una reseccion paliativa fue de 15,2 meses (DE: 13,18), y de 4,4 meses (DE: 3,66) en los no resecados (p < 0,0001). El promedio de sobrevida en los pacientes del recto resecados fue 20,5 meses (DE: 19,6), y de 5,06 meses (DE: 3,51) en el grupo no resecado (p < 0,0001). En el analisis multivariado la reseccion paliativa y, en menor medida, la albumina preoperatoria son los factores pronosticos mas relevantes en colon y en recto, con una razon de disparidad de 4 y 5 veces, respectivamente (p < 0,0001). Conclusion: La cirugia paliativa puede realizarse con bajos indices de morbimortalidad en pacientes aptos para soportar un procedimiento quirurgico mayor. En los tumores de recto la reseccion paliativa se asocia con mayor morbilidad y mayor tiempo de hospitalizacion. La reseccion del tumor primario en el contexto de una enfermedad metastasica incurable prolonga en forma significativa la sobrevida de estos pacientes y debe intentarse en los pacientes con un riesgo razonable, exceptuando los casos con carcinomatosis peritoneal masiva y ascitis.

Prior research in biology and mechanics has shown the importance of hierarchy to the performance of dry adhesive systems on rough surfaces. The gecko utilizes several levels of hierarchy that operate on length scales from millimeters to 100s of nanometers in order to maneuver on smooth and rough vertical surfaces ranging from glass to rock. The gecko's hierarchical system serves two main purposes: it permits conformation to the surface for a large effective area of contact, and it distributes the load evenly among contacting elements. We present a new two-tiered directional adhesive system that provides these capabilities for a gecko-inspired climbing robot. The distal features consist of wedge-shaped structures with a base width of 50 µm and a height of approximately 180 µm. The wedges are mounted atop angled cylindrical features, 380 µm in diameter by approximately 1 mm long. Together, the proximal and distal features bend preferentially in the direction of inclination when loaded with a tangential force, achieving a combination of directional adhesion and conformation to rough surfaces. Using this system, a four legged robot that was previously restricted to climbing smooth surfaces is able to climb vertical surfaces such as a wood panels, painted metals, and plastics. On rougher surfaces, the two-tiered system improves adhesion by a factor of five compared to the wedge features alone. The hierarchical system also improved alignment and performance for large patch sizes.

RESUMENAntecedentes: El sistema TNM de estadificacion del cancer de colon y recto (CCR) se basa enestudios de poblacion y es ampliamente utilizado en el mundo occidental. El objetivo de este estudio esevaluar el valor pronostico del TNM 2002 en una serie clinica. Pacientes y metodo: Se incluyen todos lospacientes intervenidos en forma consecutiva por un adenocarcinoma de colon y de recto. Se considero lasobrevida en meses de acuerdo al estadio TNM 2002 y se midieron otras potenciales variables anatomoclinicascomo el CEA preoperatorio, el grado de diferenciacion celular, el tamano y la localizacion del tumor. Parael analisis estadistico descriptivo se utilizo el chi cuadrado, para estimar las curvas de sobrevida se empleoel metodo de Kaplan-Meier y para comparar las curvas de sobrevida se uso el test de log-rank. Paradeterminar los factores pronosticos de mayor impacto en la sobrevida de los pacientes se empleo el modelode regresion de Cox. Resultados: En un periodo 15 anos se intervinieron de 624 pacientes (353 con untumor colon y 271 con un tumor de recto), el 55 % mujeres, con un promedio de edad de 65 anos (desviacionestandar (DE) :13,3; extremos 21-92). El seguimiento promedio de la serie fue 48 meses (extremos 2-186).En los tumores de colon resecados con intencion curativa (estadios I a IIIC), la recidiva global fue 11 %(30/268), cifra que en los tumores de recto se eleva al 30% (61/201) (p

Objetivo: evaluar nuestros Resultados alejados en términos de recidiva local, rescate y sobrevida libre de enfermedad. Método: veintiún pacientes con un cáncer de recto bajo fueron sometidos a una resección transanal completa en un periodo de 18 años (1985-2003). La estadificación preoperatoria incluyó hallazgos clínicos y endoscópicos, estudios por imágenes e histopatológicos. Los especímenes resecados correspondieron a 4 tumores T1, 13 T2 y 4 T3. Los 4 pacientes T1 sólo fueron tratados con cirugía; 6 de los 13 T2 y todos los T3 recibieron quimiorradioterapia postoperatoria. Ninguno de ellos recibió una cirugía radical secuencial. Resultados: el seguimiento (media 75 meses) registró 5 casos (23,8%) de recidiva total y 4 (19%) con falla local (3 T2 de los cuales sólo uno había recibido terapia coadyuvante y un T3 también tratado con quimiorradioterapia). Los cuatro pacientes con recidiva local accedieron a cirugía de rescate, una amputación abdominoperineal en dos casos y a una re-resección local en los otros. Dos de ellos volvieron a recidivar. La sobrevida a 5 años fue de 95,2%, y la sobrevida libre de enfermedad en el mismo periodo alcanzó a un 90,4%. En el periodo de observación hasta agosto de 2006 hay dos pacientes que fallecieron diseminados, y sólo un paciente vivo está recidivado. Conclusiones: esta experiencia confirma que la resección local transanal para cáncer de recto bajo es una buena alternativa en pacientes adecuadamente seleccionados. En tumores T2, la quimiorradioterapia adyuvante será necesaria; en tumores T3, la cirugía radical de rescate debería ser realizada oportunamente.

Background: There are no clear guidelines for the indication of elective surgery in sigmoid diverticular disease. Aim: To analyze the indications and long term results of elective surgery in sigmoid diverticular disease. Material and Methods: Retrospective review of 100 patients (age range 25-86 years, 51 male) with sigmoid diverticular disease, operated in a lapse of 22 years. Sixty seven patients answered a survey about their disease at the end of follow up. Results: Among patients aged more than 70 years, there was a higher proportion of women. The main indication for surgery was recurrent diverticulitis in 54 patients, followed by diverticular fistula in 19. A sigmoidectomy was performed in 91 patients. Stapled anastomosis was performed in half of these patients. No patient died or required reoperation in the immediate postoperative period. During a follow up ranging from 8 to 280 months, 28 patients died for causes not associated with diverticular disease and five were lost. Those patients that answered the survey were free of symptoms related to diverticular disease and did not require new operations. Conclusions: In patients with sigmoid diverticular disease and recurrent diverticulitis or with fistulae, the long term results of surgery are satisfactory (Rev Méd Chile 2005; 133: 1037-42)

Background: CEA is widely used in the follow up of patients with colorectal carcinoma. Aim: To study the value of preoperative CEA as an independent prognostic factor in colorectal carcinoma. Patients and methods: Analysis of 373 operated patients (204 females, age range 21-92 years) with colorectal carcinoma and a mean follow up of 53 months. The cutoff value for CEA was 5 ng/ml. Ninety four percent of patients had an excisable tumor, 79% had involvement of perirectal/pericolonic adipose tissue and 46% had lymph node involvement. Staging was done using Dukes-Turnbull and TNM classifications. Results: CEA was normal in 61% of cases, over 5 ng/ml in 39% and over 15 ng/ml in 22%. There was a strong correlation between mean preoperative CEA and tumor stage, depth and lymph node involvement. During the follow up, 140 patients died, 57 with normal and 83 with elevated CEA. Cancer mortality in patients subjected to a curative excision of the tumor (Dukes A-C2/TNM IIII) was 9% for colonic tumors and 36% for rectal tumors (p

Most of the studies related to insulator pollution are normally performed based on individual analysis among leakage current, relative humidity and equivalent salt deposit density (ESDD). This paper presents a correlation analysis between the leakage current and the acoustic emissions measured in a 230 kV electrical substations in the city of Barranquilla, Colombia. Furthermore, atmospheric variables were considered to develop a characterization model of the insulator contamination process. This model was used to demonstrate that noise emission levels are a reliable indicator to detect and characterize pollution on high voltage insulators. The correlation found amount the atmospheric, electrical and sound variables allowed to determine the relations for the maintenance of ceramic insulators in high-polluted areas. In this article, the results on the behavior of the leakage current in ceramic insulators and the sound produced with different atmospheric conditions are shown, which allow evaluating the best time to clean the insulator at the substation. Furthermore, by experimentation on site and using statistical models, the correlation between ambient variables and the leakage current of insulators in an electrical substation was obtained. Some of the problems that bring the external noise were overcome using multiple microphones and specialized software that enabled properly filter the sound and better measure the variables. La mayoría de los estudios relacionados con la contaminación de aisladores son desarrollados normalmente con base en un análisis individual entre la corriente de fuga, la humedad relativa y la densidad de los depósitos de sal equivalente (ESDD). Este trabajo presenta un análisis de correlación entre la corriente de fuga y las emisiones acústicas medidas en una subestación eléctrica de 230 kV, en la ciudad de Barranquilla, Colombia. Además, se consideraron variables atmosféricas para desarrollar un modelo de caracterización del proceso de la contaminación de los aisladores eléctricos. Este modelo fue utilizado para demostrar que los niveles de emisión de ruido son un indicador fiable para detectar y caracterizar la contaminación en aisladores de alta tensión. La correlación encontrada entre las variables atmosféricas, eléctricas y las de sonido permitieron determinar las relaciones para el mantenimiento de los aisladores cerámicos en zonas de alta contaminación. En este artículo se muestran los resultados de la investigación sobre el comportamiento de la corriente de fuga en aisladores cerámicos y el sonido que se producen ante diferentes condiciones atmosféricas, lo cual permite evaluar el mejor momento para limpiar el aislador en la subestación. Además, mediante experimentación in situ y utilizando modelos estadísticos, se obtuvo la correlación entre las variables ambientales y la corriente de fuga de aisladores en una subestación eléctrica. Algunos de los inconvenientes que trae el ruido externo en la medición fueron superados utilizando varios micrófonos y software especializado que permitían filtrar correctamente el sonido y lograr una mejor medición de las variables.

Background: Ten to 22% of lower gastrointestinal bleedings require emergency surgery. The overall mortality of the procedure is 22%. Aim: To report our experience in the management of patients with massive lower gastrointestinal bleeding. Patients and methods: Retrospective analysis of 20 patients (10 male) aged 19 to 79 years old, with lower gastrointestinal bleeding. Results: Nine patients were operated on after the bleeding stopped and 11 were operated while still bleeding. In ten, the cause of bleeding was diverticular disease or angiodysplasia. In four, the bleeding originated in the small bowel and in 7 it was of vascular origin. Two patients with a torrential bleeding, were operated on without prior study. Colonoscopy, done in 18 patients, identified the bleeding site in 66% of cases. Scintigraphy was performed in 7 patients and it was positive in five without operative mortality. Selective angiography was done in four patients and was positive in three. A partial intestinal resection was performed in 15 patients and a total colectomy in five without operative mortality. Six patients had major postoperative complications and mean hospital stay was 18 days. Patients have been followed for 9 to 144 months and six have died. Eleven patients were reassessed and all have complete fecal continence. Conclusions: In this series, the main causes of massive lower gastrointestinal bleeding were diverticulosis and angiodysplasia. In a high percentage of patients, the bleeding originated in the small bowel (Rev Méd Chile 2002; 130: 869-78)

We report a 15 years old girl presenting with severe hematochezia with secondary anemia and hemodynamic decompensation, rectal prolapse and spontaneous anal elimination of polyps. She had no family history of polyposis and a search for the disease in her close relatives was negative. A complete diagnostic work up did not find polyps in other segments of the digestive tract. Colonoscopy showed more than 200 polyps between the cecum and the rectum. Pathological analysis confirmed the presence of retention polyps with adenomatous areas and mild atypia. The patient was subjected to a proctocolectomy with ileal pouch and sphincteric preservation, using a mechanical suture. Postoperative evolution was uneventful and after 24 months of follow up, the patient is asymptomatic, with two stool movements per day and without incontinence.