Loop-mediated isothermal amplification (LAMP) assay for the diagnosis of fasciolosis in sheep and its application under field conditions

[EN] Background: Loop-mediated isothermal amplification (LAMP) is a very specific, efficient, and rapid gene amplification procedure in which the reaction can run at a constant temperature. In the current study we have developed a LAMP assay to improve the diagnosis of Fasciola spp. in the faeces of sheep. Findings: After the optimisation of the LAMP assay we have shown similar results between this technique and the standard PCR using the outer primers of the LAMP reaction. In both cases the limit of detection was 10 pg; also, the diagnosis of fasciolosis was confirmed during the first week post-infection in experimental infected sheep by both techniques. In eight naturally infected sheep, the infection with F. hepatica was confirmed in all animals before a treatment with triclabendazole and on day 30 post treatment in two sheep using the LAMP assay; however, when we carried out the standard PCR with the outer primers, the results before treatment were the same but on day 30 post-treatment the infection was only confirmed in one out of the two sheep. On the other hand, the standard PCR took around 3 h to obtain a result, comparing with 1 h and 10 min for the LAMP assay. Conclusions: The LAMP assay described here could be a good alternative to conventional diagnostic methods to detect F. hepatica in faeces since it solves the drawbacks of the standard PCRSIWe thank Drs Manga-González and González-Lanza (Instituto de Ganadería de Montaña, CSIC-ULE, Spain) for providing DNA samples of D. dendriticum and C. daubneyi. This study has been funded by the national project INIA (Instituto Nacional de Investigaciones Agrarias: RTA2010-00094-C03-02), Ministry of Economy and Competitiveness (Ministerio de Economia y Competitividad), and also co-funded by the European Regional Development Fund (Fondos Feder

La carrera de Estados Unidos y China por la hegemonía económica en el sistema-mundo: poder individual y poder estructural en una perspectiva de red

Since 1978, China's economy has undergone a profound transformation, transitioning from a largely rural structure to a global powerhouse in technology and economy. This shift has instigated academic debate regarding whether China could replace the US as the leading global economic power. This thesis develops a dynamic structural methodology, offering a novel and more in-depth perspective that overcomes the limitations of classic approaches, which focus solely on material capabilities. The objective is to discern whether China is overtaking the US regarding global economic dominance or if this trend will materialize shortly. To this end, an exhaustive comparison of the individual capabilities of both nations in critical areas such as production, technology, trade, and finance is conducted, as well as network analysis of global financial and technological interconnections. This approach provides a detailed insight into each country's structural power and future predictions based on the network growth mechanisms ("the fit get richer" and "the rich get richer"). The findings reveal that although China has significantly enhanced its capabilities, surpassing the US in certain aspects, it is still far from dethroning the US hegemony, which maintains its dominance thanks to its structural power in the financial and technological realms.Desde 1978, la economía china ha experimentado una profunda transformación, pasando de una estructura mayoritariamente rural a una potencia mundial en tecnología y economía. Este cambio ha suscitado un debate académico sobre si China puede sustituir a EE. UU. como primera potencia económica mundial. Esta tesis desarrolla una metodología dinámico-estructural, ofreciendo una perspectiva novedosa y más profunda que supera las limitaciones de los enfoques clásicos, centrados únicamente en las capacidades materiales. El objetivo es discernir si China está superando a EE. UU. en términos de dominio económico mundial, o si esta tendencia se materializará en un futuro próximo. Para ello, se lleva a cabo una comparación exhaustiva de las capacidades individuales de ambas naciones en áreas críticas como la producción, la tecnología, el comercio y las finanzas, así como un análisis en red de las interconexiones financieras y tecnológicas mundiales. Este enfoque proporciona una visión detallada del poder estructural de cada país y predicciones futuras basadas en los mecanismos de crecimiento de la red ("fit get richer" y "rich get richer"). Las conclusiones revelan que, aunque China ha mejorado notablemente sus capacidades individuales, superando a EE. UU. en ciertos aspectos, aún está lejos de destronar la hegemonía estadounidense, que mantiene su dominio gracias a su poder estructural en los ámbitos financiero y tecnológico

Implementation of an extended ZINB model in the study of low levels of natural gastrointestinal nematode infections in adult sheep

Background: In this study, two traits related with resistance to gastrointestinal nematodes (GIN) were measured in 529 adult sheep: faecal egg count (FEC) and activity of immunoglobulin A in plasma (IgA). In dry years, FEC can be very low in semi-extensive systems, such as the one studied here, which makes identifying animals that are resistant or susceptible to infection a difficult task. A zero inflated negative binomial model (ZINB) model was used to calculate the extent of zero inflation for FEC; the model was extended to include information from the IgA responses. Results: In this dataset, 64 % of animals had zero FEC while the ZINB model suggested that 38 % of sheep had not been recently infected with GIN. Therefore 26 % of sheep were predicted to be infected animals with egg counts that were zero or below the detection limit and likely to be relatively resistant to nematode infection. IgA activities of all animals were then used to decide which of the sheep with zero egg counts had been exposed and which sheep had not been recently exposed. Animals with zero FEC and high IgA activity were considered resistant while animals with zero FEC and low IgA activity were considered as not recently infected. For the animals considered as exposed to the infection, the correlations among the studied traits were estimated, and the influence of these traits on the discrimination between unexposed and infected animals was assessed. Conclusions: The model presented here improved the detection of infected animals with zero FEC. The correlations calculated here will be useful in the development of a reliable index of GIN resistance that could be of assistance for the study of host resistance in studies based on natural infection, especially in adult sheep, and also the design of breeding programs aimed at increasing resistance to parasites

Aborto epidémico y endémico asociado a la infección por Neospora caninum en el ganado bovino: relación entre la respuesta inmune y las consecuencias de la infección a lo largo de la gestación

Neospora caninum es un protozoo intracelular obligado perteneciente al Phylum Apicomplexa. La neosporosis bovina se considera una de las principales causas de fallo reproductivo en el ganado bovino. La transmisión transplacentaria del parásito puede originar aborto ó el nacimiento de terneros congénitamente infectados. La transmisión transplacentaria endógena ocurre tras la recrudescencia de una infección crónica en la hembra durante la gestación, mientras que la exógena se da tras una primoinfección adquirida de forma postnatal. Un mayor conocimiento de la epidemiología, integrado con el empleo de adecuadas técnicas de diagnóstico serológico son la base del control. El objetivo del presente estudio fue determinar mediante diferentes pruebas diagnósticas la relación existente entre la respuesta serológica desarrollada por reproductoras bovinas infectadas a lo largo de una gestación, el origen de la infección y sus repercusiones reproductivas.Neospora caninum is an apicomplexan protozoan parasite. At present bovine neosporosis is one of the main causes of reproductive failure in cattle worldwide. Transplacental transmission of the parasite can lead to abortion or birth of congenitally infected calves. Endogenous transplacental transmission occurs as a consequence of the recrudescence of a previous chronic infection in the cow during gestation. On the other hand, exogenous transplacental transmission occurs after an acquired postnatal primo infection. Control programmes are based on updated knowledge about the epidemiology together with the employment of appropriate diagnostic serological tests. The aim of the present study was to determine the relationship between the serologic response developed by infected breeding cattle along gestation, the mode of transmission and the future consequences in reproduction

Persistence of soil loosening with bent leg subsoilers in no tillage systems

La adopción de la siembra directa en Argentina ha tenido consecuencias negativas para los suelos. Independientemente de los beneficios de la técnica, la compactación por el tránsito de máquinas agrícolas puede llevar a los suelos a condiciones limitantes para el crecimiento de los cultivos. El objetivo del presente estudio fue evaluar el efecto y la persistencia de la descompactación por tratamiento mecánico del suelo, realizado con herramientas de montantes angulados rectos del tipo Pa-ratill, en un sistema con manejo en siembra directa continua. El ensayo se realizó en la localidad de Azcuénaga, partido de San Andrés de Giles, Provincia de Buenos Aires, en un suelo Argiudol típico. Los tratamientos ensayados fueron: siembra directa continua sin descompactación (SDC) y siembra directa con descompactación (SDD). Los parámetros evaluados fueron infiltración básica con infiltrómetro de disco, resistencia mecánica con penetrómetro de cono, densidad aparente por el método del cilindro y humedad gravimétrica. Del análisis de los resultados de densidad aparente y resistencia a la penetración surge que un suelo con 10 años de siembra directa continua presenta niveles de compactación que pueden limitar el desarrollo de los cultivos. En estos suelos los descompactadores tipo Paratill generan un aflojamiento no uniforme en la superficie trabajada, concentrándose la roturación en las líneas de acción de la herramienta. Como consecuencia, mejora la infiltración básica y se reduce la resistencia mecánica al desarrollo de raíces. Si bien este aflojamiento persiste hasta un año, el incremento de la infiltración básica que provoca la descompactación se extiende el doble de tiempo.Adoption of no-tillage cropping practices in Argentina has had a negative impact on soil quality and crop production. Regardless of the benefits of this technique, compaction by farm machinery traffic can lead to soil constraints to crop growth. The aim of this study was to evaluate the effect and persistence of decompaction by mechanical treatment of the soil with bent leg subsoilers like Paratill, in continuous no-tillage systems. The trial was conducted near Azcuénaga, Province of Buenos Aires, on a typical Argiudol soil. The treatments tested were: continuous no-tillage (SDC) and no-tillage with soil loosening (SDD). The soil properties evaluated were: basic infiltration rate, mechanical strength, bulk density and gravimetric moisture. The results of bulk density and penetration resistance indicate that a soil with 10 years of continuous tillage presents compaction levels that can limit crop development. In these types of soils, the use of a Paratill bent leg subsoiler generates an irregular soil loosening in the lines of work. This results in improved soil basic infiltration and reduced mechanical resistance to root growth. While loosening extends up to one year, increased basic infiltration extends twice as longFil: Guecaimburu, Juan Martín. Universidad Nacional de Luján. Departamento de Tecnología; ArgentinaFil: Introcaso, Rafael. Universidad Nacional de Luján. Departamento de Tecnología; ArgentinaFil: Vázquez, Juan Manuel. Universidad Nacional de Luján. Departamento de Tecnología; ArgentinaFil: Rojo, Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; Argentina. Universidad Nacional de Luján. Departamento de Tecnología; ArgentinaFil: Reposo, Gisela Paola. Universidad Nacional de Luján. Departamento de Tecnología; Argentin

El ADN de un profesor del siglo XXI

La sociedad avanza a un ritmo vertiginoso y la educación se encuentra ante nuevos paradigmas educativos a los que tiene que dar respuesta y que implican un replanteamiento del modelo de enseñanza actual. Las competencias que adquieren las futuras generaciones de docentes a través del Máster en Profesorado forman parte del ADN del profesor del siglo XXI, al que se capacitará para diseñar metodologías innovadoras a medida de las necesidades de los estudiantes, a los que tendrá que conseguir enseñar a pensar