Analysis of the Peasant Reserve Zone in Catatumbo: of the alleged influence of armed groups outside the law in the regional project.

Para crear una zona de éstas, los campesinos deben organizarse y diseñar un plan de desarrollo en el que establezcan cómo harán para vivir dignamente allí, cómo se sostendrán económicamente y cómo satisfarán sus necesidades de servicios básicos. El Estado tiene que darles el apoyo que necesiten para que tengan infraestructura, salud, alcantarillado, energía, en fin, todo lo que les permita estar bien.NoTo create a zone like these, the peasants must organize and design a development plan in which they will set out what they need to do to live with dignity in there, how they will sustain financially and how they will satisfy their needs for basic services. The state must give them the support they need , so the can have an infrastructure, health, sanitation, energy, in short, everything that allows them to be fine.Pregrad

Entrevista al profesor Alan Bishop

En este artículo, se presentan las ideas del profesor Alan Bishop sobre la Etnomatemática, sus objetivos, su metodología, la relación entre Etnomatemática y Educación Matemática y la enseñanza de las matemáticas en aulas multiculturales. Esta entrevista fue realizada el miércoles, 29 de noviembre de 2006 en el Seminario de formación avanzada: tres fases básicas en un estudio de investigación doctoral en educación. Universidad Distrital Francisco José de Caldas. Bogotá, Colombia

Diseño y optimización de ruido de fase en osciladores utilizando la NDF.

In this paper the use of the NDF is proposed as a general method suitable for analysing any oscillator topology. The most important advantage of this method is that it provides an unique procedure to analyse any oscillator. It also makes possible the phase noise optimization in the linear design phase for any oscillator. An additional advantage of this method is that it does not require any proviso verification as all classic methods need. The use of the NDF method is illustrated with the design of two examples. These two oscillators are manufactured and the simulation results are compared with the measurements showing good agreement. These results confirm the excellent possibilities of the proposed method for low noise oscillators design

Transpose return relation method for designing low noise oscillators

In this paper, a new linear method for optimizing compact low noise oscillators for RF/MW applications will be presented. The first part of this paper makes an overview of Leeson's model. It is pointed out, and it is demonstrates that the phase noise is always the same inside the oscillator loop. It is presented a general phase noise optimization method for reference plane oscillators. The new method uses Transpose Return Relations (RRT) as true loop gain functions for obtaining the optimum values of the elements of the oscillator, whatever scheme it has. With this method, oscillator topologies that have been designed and optimized using negative resistance, negative conductance or reflection coefficient methods, until now, can be studied like a loop gain method. Subsequently, the main disadvantage of Leeson's model is overcome, and now it is not only valid for loop gain methods, but it is valid for any oscillator topology. The last section of this paper lists the steps to be performed to use this method for proper phase noise optimization during the linear design process and before the final non-linear optimization. The power of the proposed RRT method is shown with its use for optimizing a common oscillator, which is later simulated using Harmonic Balance (HB) and manufactured. Then, the comparison of the linear, HB and measurements of the phase noise are compared

Desarrollo de un espacio web de prácticas de neuroanatomía y embriología humanas

Presentamos dos proyectos que se relacionan, el primero con la mejora en las prácticas de neuroanatomía para alumnos de segundo de medicina, y el segundo con la enseñanza de la embriología humana, un proyecto bastante complejo del que presentamos aquí su inicio, pero que deseamos convertirlo a medio plazo en una asignatura virtual

A comparison of tumour and host prognostic factors in screen-detected versus non screen-detected colorectal cancer: a contemporaneous study

Aim: In addition to TNM stage, there are adverse tumour and host factors, such as venous invasion and the presence of an elevated systemic inflammatory response (SIR) that influence the outcome in colorectal cancer. The present study aimed to examine how these factors varied in screen detected (SD) and non-screen detected tumours (NSD). Method: Prospectively maintained databases of the prevalence round of a biennial population FOBt screening programme and a regional cancer audit database were analysed. Interval cancers (INT) were defined as cancers identified within two years of a negative screening test. Results: Of the 395 097 invited, 204 535 (52%) responded, 6159 (3%) tested positive, and 421 (9%) had cancer detected. From this cohort, a further 708 (63%) NSD patients were identified (468 (65%) non-responders, 182 (25%) INT cancers and 58 (10%) did not attend or did not have cancer diagnosed at colonoscopy). Comparing SD and NSD patients, SD patients were more likely to be male, and have a tumour with a lower Dukes stage (both p<0.05). On stage-by-stage analysis, SD patients had less evidence of an elevated SIR (p<0.05). Both the presence of venous invasion (p=0.761) and an elevated SIR (p=0.059) were similar between those with INT cancers and in those that arose in non-responders. Conclusion: Independent of TNM stage, SD tumours have more favourable host prognostic factors than NSD tumours. There is no evidence that INT cancers are biologically more aggressive than those that develop in the rest of the population and hence are likely to be due to limitations of screening in its current format

Low-cost measurement for a secondary Mode S radar transmitter

A low-cost, multiple-purpose, and high-precision timing test setup for the measurements of secondary Mode S radar transmission signal was proposed. The goal was to fully guarantee compliance of the proposed transmitter under test with the really hard International Civil Aircraft Organization requirements using traditional measurement equipment, which was difficult or even impossible to ensure up to now. The low-cost structure proposed in this paper allows the user to perform measurements independently of the measurements performed by the pieces of test equipment shelled by the manufacturer of radar, which is a very important aspect since the independence of the verifications is a mandatory requirement established by the safety standards of civil aviation. The proposed setup has been used to verify several transmitters with some defects that are not detected by monopulse secondary surveillance radar specific pieces of test equipment that are focused on more high-level functionalities. It also is valid and it has been used, as a general-purpose setup, for testing other radio navigation aids

Evidence for suppression of immunity as a driver for genomic introgressions and host range expansion in races of Albugo candida, a generalist parasite

How generalist parasites with wide host ranges can evolve is a central question in parasite evolution. Albugo candida is an obligate biotrophic parasite that consists of many physiological races that each specialize on distinct Brassicaceae host species. By analyzing genome sequence assemblies of five isolates, we show they represent three races that are genetically diverged by ∼1%. Despite this divergence, their genomes are mosaic-like, with ∼25% being introgressed from other races. Sequential infection experiments show that infection by adapted races enables subsequent infection of hosts by normally non-infecting races. This facilitates introgression and the exchange of effector repertoires, and may enable the evolution of novel races that can undergo clonal population expansion on new hosts. We discuss recent studies on hybridization in other eukaryotes such as yeast, Heliconius butterflies, Darwin’s finches, sunflowers and cichlid fishes, and the implications of introgression for pathogen evolution in an agro-ecological environment