Resumen 17. La eimeriosis es una enfermedad causada por un protozoario del género Eimeria que afecta a todos los animales silvestres y domésticos. Dado que en Perú no existen reportes previos y en otras regiones de Latinoamérica la prevalencia es nula o baja en perros domésticos, el objetivo del presente trabajo fue determinar la prevalencia de Eimeria sp en canes de la ciudad de Cajamarca mediante un análisis coproparasitológico, utilizando el método de Faust y efectuando el estudio morfométrico de los ooquistes. Se obtuvieron aleatoriamente 206 muestras fecales en la zona Este de Cajamarca, las cuales fueron inmediata mente procesadas en el Laboratorio de Parasitología Veterinaria de la Universidad Nacional de Cajamarca, Perú. La prevalencia de Eimeria sp fue de 10,68% en canes domésticos. En el estudio morfométrico de los ooquistes, se determinaron medidas de largo y ancho, que presentaron promedios de 21,73 pm de largo y 17,77 pm de ancho para la forma ovoide; 16,40 pm de largo y 15,31 pm de ancho para la forma esférica, y finalmente 25,54 y 18,51 pm respectivamente para la forma elipsoidal. Estos resultados prueban la presencia e infección leve por Eimeria sp en perros domésticos en la serranía norte del Perú, sugiriendo además, futuros estudios del protozoario para evitar riesgos o afecciones a la salud pública.

Abstract 21. Eimeriosis is a disease caused by a protozoan of the genus Eimeria that affects all wild and domestic animals. Given that there are no previous reports in Peru and in other regions of Latin America, the prevalence is null or low in domestic dogs, the objective of this work was to determine the prevalence of Eimeria sp in dogs from the city of Cajamarca through coproparasitological analysis, using the Faust method and making the morphometric study of the oocysts. It obtained 206 fecal samples randomly in the east area of Cajamarca and were immediately processed at Laboratorio de Parasitología Veterinaria de la Universidad Nacional de Cajamarca, Perú. The prevalence found was 10.68% for Eimeria sp in domestic dogs. To the morphometric study of the oocysts, measurements of length and width were determined; these presenting an average of 21.73 pm long and 17.77 pm wide for the ovoid shape; 16.40 pm long and 15.31 pm wide for the spherical shape, finally 25.54 and 18.51 pm respectively for the ellipsoidal shape. These results prove the presence and mild infection by Eimeria sp in domestic dogs in the northern highlands of Peru, also suggesting future studies of the protozoan to avoid risks or conditions to public health.

RESUMO: A busca por alternativas no manejo de plantas daninhas sem a utilização exclusiva de herbicidas pode contribuir para aumento da sustentabilidade na produção agrícola na região Amazônica. Objetivou-se neste estudo avaliar o potencial alelopático de plantas de cobertura, sobre a planta daninha vassourinha-de-botão (Spermacoce verticillata L.). Três níveis de palhada (1; 2,5 e 5 mg cm-2) de treze plantas de cobertura (Cajanus cajan, Canavalia ensiformis, Crotalaria juncea, C. ochroleuca, C. spectabilis, Mucuna aterrima, M. cinereum, Pennisetum glaucum, Sorghum bicolor, S. sudanense, Urochloa brizanha cv. Xaraés, U. brizantha cv. Piatã e U. ruziziensis) foram avaliados, sobre a germinação e o crescimento inicial da planta daninha e da alface. Dois experimentos foram instalados (planta daninha e alface) em esquema fatorial (plantas de cobertura x níveis de palhada) com tratamento adicional (testemunha sem palhada) em delineamento experimental inteiramente casualizado, com quatro repetições. As palhadas das plantas de cobertura inibiram a germinação e o crescimento inicial das plantas alvo. Os maiores níveis de palhada promoveram reduções de 44,0 e 78,8% no comprimento da radícula em relação à menor dose (1 mg cm-2), para a alface e para a vassourinha-de-botão, respectivamente. A maior sensibilidade aos aleloquímicos foi observada sobre a radícula. Os maiores efeitos supressivos na germinação da planta daninha foram promovidos pelo Cajanus cajan, Urochloa brizanha cv. Xaraés, Mucuna cinereum, M. aterrima, Canavalia ensiformis, Crotalaria juncea, C. spectabilis e U. ruziziensis. A utilização de plantas de cobertura em área de cultivo sob plantio direto representa uma prática de manejo integrado no controle da Spermacoce verticillata.

ABSTRACT: Searching for alternatives to deal with weeds without the exclusive use of herbicides can increase the sustainability of agricultural production in the Amazon region. This study aimed to evaluate the allelopathic potential of cover crops on the weed shrubby false buttonweed (Spermacoce verticillata L.). Three straw levels (1; 2.5 and 5 mg cm-2) of thirteen cover crops (Cajanus cajan, Canavalia ensiformis, Crotalaria juncea, C. ochroleuca, C. spectabilis, Mucuna aterrima, M. cinereum, Pennisetum glaucum, Sorghum bicolor, S. sudanense, Urochloa brizanha cv. Xaraés, U. brizantha cv. Piatã and U. ruziziensis) were assessed on germination and initial growth of weed and lettuce. We carried out two experiments (weed and lettuce) in a factorial scheme (cover crops x straw levels) with additional treatment (control without straw) in a completely randomized experimental design, with four replicates. The straw of the cover crops inhibited the germination and initial growth of the target plants. The highest straw levels promoted 44.0 and 78.8% reductions in radicle length in relation to the lowest dose (1 mg cm-2), for lettuce and Spermacoce verticillata, respectively. The highest sensitivity to allelochemicals occurred on the radicle. The major suppressive effects on weed germination were promoted by Cajanus cajan, Urochloa brizanha cv. Xaraés, Mucuna cinereum, M. aterrima, Canavalia ensiformis, Crotalaria juncea, C. spectabilis and U. ruziziensis. Cover crops use is an integrated practice management to control Spermacoce verticillata under no-tillage system.

Abstract: This work describes a method to achieve a nearly seamless bonding between two polydimethylsiloxane (PDMS) surfaces. This material is widely used to realize microfluidic systems, and obtaining a strong union is an important step in the fabrication process. From the proposed bonding method, a minimal interface is accomplished, useful for hermetic seals in microfluidic systems. The presented method relies in the surface activation by oxygen plasma and the interaction of said treated surface with uncured PDMS. A comparison of bonding methods is presented in this paper in order to assess the performance of the bonding process and verify the interface formed between the bonded surfaces. The intended application of the presented method is the fabrication of pressure sensors, micropumps, microchannels, microfluidic pumps, valves, mixers and other structures that demand a complete seal over the bonded surfaces.

A review of state the art about the structure, classification and operation of biosensors applied in food and biological areas is presented. This review is focused to mechanical biosensors that use mili, micro and nanocantilevers. Basic concepts of atomic force microscopy and optical systems, used as testing platform of biosensors are described. The most funcionalized strategies and geometrical configurations are also explained. Mathematical methods for evaluating the performance in static and dynamic mode of the mechanical biosensors are reviewed and examples of application in biological and food areas are provided. An overall description of the operational effect of operation conditions and design variables on the sensitivity devices is also proposed. A brief description of the design processes and manufacturing of cantilevers based silicon technology as well as information about BioMEMS and BioNEMS are provided. Finally, overall trends in research, development and commercialization of biosensors are described briefly as well as probable areas of development in food biosensors. Thereby, this review provides an overall view of biosensors, as an exploratory guide to identify the most important aspects of this technology.

Este trabajo presenta una revisión del estado del arte acerca de la estructura, funcionamiento y clasificación de biosensores aplicados al área biológica y alimentaria. Esta revisión se enfoca hacia biosensores mecánicos que usan mili, micro y nanocantilevers (vigas en voladizo), exponiendo los conceptos básicos de microscopía de fuerza atómica y sistemas ópticos usados como plataforma para la evaluación estos sensores. Se describen además las estrategias de funcionalización y las configuraciones geométricas más usadas, así como los métodos matemáticos para evaluar el desempeño de biosensores mecánicos en modo estático y dinámico, proporcionando ejemplos de aplicación. Se propone una descripción global del efecto de las variables de operación y diseño sobre la sensibilidad de los dispositivos. Se exponen brevemente los procesos de diseño y fabricación de cantilevers basados en la tecnología de silicio, así como información acerca de los BioMEMS y BioNEMS. Finalmente, se describen las tendencias globales de investigación, desarrollo y comercialización de biosensores, así como las posibles áreas de desarrollo para biosensores en alimentos. De esta forma, esta revisión proporciona un panorama global de los biosensores, que pretende servir como guía introductoria para ubicar los aspectos más importantes de esta tecnología.