La fruticultura Colombiana durante las últimas décadas ha tenido una notable dinámica reflejada en un crecimiento promedio anual en área de 13%, el más alto de los renglones agrícolas. El país posee condiciones favorables para el desarrollo de una amplia gama de frutales y en la actualidad cuenta con 138.000 hectáreas repartidas en 72 especies para con-sumo en fresco y procesamiento.

Si el tipo de proyecto fue definido como de investigación determine si es de investigación básica cuando se pretende generar conocimiento científico. Estratégica cuando se busca generar conocimiento científico o tecnológico de alto impacto en temas particulares, aplicada cuando se pretende generar tecnologías y metodologías en ci corto y mediano plazo para la solución de problemas específicos y adaptativa cuando se va a ajustar nuevas tecnologías y metodologías a las condiciones del cliente.

Lechuga-Lactuca sativa

Este manual es una herramienta de uso y consulta diarios para las organizaciones del Plan Nacional de Semilla y los pequeños y medianos productores de semilla, o de cualquier sistema agrícola, que busquen ejercer un buen control y tener una base para la toma de decisiones a partir de los datos obtenidos en sus procesos productivos. Mediante un lenguaje sencillo y una estructura lógica, se pretende que los lectores se apropien de los conceptos y aprovechen las herramientas del cálculo de costos propuestas por AGROSAVIA en cada uno de sus procesos productivos y en sus hogares. El documento lleva al lector a entender de manera fácil la dinámica básica para poder calcular los costos, cómo hacer un análisis que contribuya a la toma de decisiones y, por ende, mejorar los resultados de sus procesos productivos.

Una de las principales limitantes que presenta la producción ganadera se relaciona con la variabilidad climática, manifestada en períodos concentrados de lluvias o, en su defecto, períodos de prolongada sequía, que, en muchos casos, es mayor a tres meses. Estos eventos limitan la disponibilidad y la calidad de las pasturas, lo que genera una marcada disminución en la producción de carne y leche, bajos índices reproductivos, altas tasas de mortalidad y bajos porcentajes de natalidad, que hacen ineficiente el sistema de producción bovino. Dentro de esta limitante, uno de los retos a los que se enfrentan los productores se dirige a la integración de fuentes alternativas de alimentación de acuerdo con las condiciones biofísicas y socioculturales de las zonas de producción. Estas fuentes de forraje deben tener alta aceptación por parte de los productores y elevado valor nutritivo para compensar el déficit de disponibilidad y calidad de los pastos durante las épocas críticas.

The research on electrochemical carbon molecule oxidation started in the past years as new electrochemistries were researched for new fuel cells systems and batteries that may line up as backup energy supply and storage systems in off-grid and on-grid microgrids, as modeled by our group at the University of Twente [1-3]. By lining up these two disciplines we hope to support the bridge between new electrochemical systems on one side, (pilot) production with partner companies, prediction, and validation of systems upon implementation in microgrids by our group. The electrochemical oxidation of glycerol in alkaline aqueous solution has been studied on gold and gold coated metals (Zn-Au and Cu-Au) by voltammetry and EIS (Electrochemical impedance spectroscopy) for possible use in a new fuel cell as an outlet for the excess glycerol that is produced in the biodiesel industry. The observations show that the gold surface may change upon cycling by cyclic voltammetry. Besides, the current density shows non-linear behavior with the square root of the scan rate, implying that the reaction is not totally controlled by diffusion. EIS analysis using the EQUIVCRT software revealed that one out of twenty tested equivalent circuits fitted the data well at potentials of -0.05 V,- 0.15 V and -0.25 V vs. Ag/AgCl, identifying resistors and a Warburg element in parallel with the double layer capacitance, the elements are possibly related to the presence of double layers associated with hydroxypyrovate and oxalate ions. The results are consistent with the low-frequency error fitting analysis (10-4), AC Simulink-Matlab fitting responds and the Kronig-Kramers transform test. The tested Zn-Au and Cu-Au electrodes show similar voltammetry behavior as the gold electrode, as witnessed by the results of cycle analysis and the scan rate analysis. The discharge chronoamperometry test further shows that the Zn-Au electrode and Cu-Au have higher current densities than the gold electrode at a potential of -0.25 V vs. Ag/AgCl (5 mA cm-2, 4.5 mA cm-2, and 3 mA cm-2 respectively).

Abstract: Close-knit relationships are a distinctive facet of subsistence living, in which survival mode entrepreneurship is a way of life. These relationships fuel “bonding social capital” within informal economies as people rely on others to work, consume, and cope with scarce resources. At the same time, policy agendas encourage business growth and social mobility by shifting informal microenterprises into the formal economy. However, success in formalized contexts requires a different form of social capital—that is, “bridging social capital” with people outside one’s immediate social network and across institutional structures. Yet policy programs often stop short of addressing how subsistence entrepreneurs manage the inherent tensions across these forms of social capital. As such, this study unpacks the contextual value of social capital using data collected with street vendors in an urban Latin American setting. The analysis identifies four entrepreneurial paths pursued by street vendors and articulates the relative value of bonding and bridging social capital across different economic and social positions. The findings advance insights for a community-centric public policy approach and offer guidance for segmentation and value proposition development within subsistence entrepreneurship programs. Resumen: Las relaciones estrechas son una faceta distintiva de la vida de subsistencia, en la que el espíritu empresarial de modo de supervivencia es una forma de vida. Estas relaciones alimentan el ""capital social"" dentro de las economías informales ya que las personas dependen de otros para trabajar, consumir y hacer frente a los recursos escasos. La agenda pública fomenta el crecimiento empresarial y la movilidad social buscando trasladar a las microempresas informales a la economía formal. Sin embargo, el éxito en los contextos formales requiere una forma diferente de capital social, generando vínculos con las personas fuera de la red social inmediata y entre las estructuras institucionales. Sin embargo, los programas públicos no llegan a abordar cómo los empresarios de subsistencia manejan las tensiones inherentes a estas formas de capital social. Como tal, este estudio analiza el valor contextual del capital social utilizando datos recopilados con vendedores ambulantes en un entorno urbano latinoamericano. El análisis identifica cuatro caminos emprendedores que persiguen los vendedores ambulantes y articula el valor relativo de vincular y unir el capital social en diferentes posiciones económicas y sociales. Los hallazgos aportan ideas para un enfoque de política pública centrado en la comunidad y ofrecen orientación para la segmentación y el desarrollo de propuestas de valor dentro de los programas de emprendimiento de subsistencia.

The research topic was about the responses of Gammarus pulex to chemical signals released from the predator fish, Leuciscus idus. The aim of this study is to compare the responses of individuals of G.pulex when these individuals are alone and in group. This research was done because there was lack of information about single and group responses of G.pulex to chemical signals released from predators. Three experiments (a pre-experiment, main experiment and a side experiment) were performed to compare the single and group responses of G.pulex to chemical stimuli. The first two experiments consisted in three treatments named Normal, Control and Fish water. The normal and control treatments were made by Dutch Standard Water whereas the fish water contained chemical cues of the predatory fish, L.idus. The side experiment included ammonium as a fourth treatment. The reason of the ammonium treatment was to compare the responses of G.pulex to ammonium and fish water to see if the responses of G.pulex could be stress responses to the ammonium rather than the fish cue contained in the fish water. In general, individuals and groups of G.pulex showed the lowest values of activity under the fish water treatment. In singles and groups of G.pulex, there were significant differences between the control and fish water and between the normal and fish water treatments indicating that the singles and groups respond to the fish water, which was the predator chemical source. Also, there were significant differences between the ammonium and fish water treatments suggesting that G.pulex distinguished between these two chemical sources. Generally, G.pulex tended to reduce activity in the presence of fish water, however, not all the individuals of G.pulex reduced the activity in the same manner, which suggested that there were variations in individual responses to the predator chemical source.

The indiscriminate use of antibiotics and the emergence of resistant microorganisms have become a major challenge for the food industry. The purpose of this work was to microencapsulate the bacteriophage UFV-AREG1 in a calcium alginate matrix using microfluidic devices and to study the viability and efficiency of retention. The microcapsules were added to gel of propylene glycol for use as an antimicrobial in the food industry. The technique showed the number of the phage encapsulation, yielding drops with an average 100–250 ?m of diameter, 82.1 ± 2% retention efficiency and stability in the gel matrix for 21 days. The gel added to the microencapsulated phage showed efficiency (not detectable on the surface) in reducing bacterial contamination on the surface at a similar level to antimicrobial chemicals (alcohol 70%). Therefore, it was possible to microencapsulate bacteriophages in alginate-Ca and apply the microcapsules in gels for use as sanitizers in the food industry.

Abstract: Aspergillus fumigatus is a fungus very well known in medicine because is responsible of invasive aspergillosis (IA) in immunocompromised patients. The use of antifungals for this disease, in particular azoles, had given a good result until the appearance of the first azole-resistant aspergillosis in 1997. Since then more cases with different mechanisms of acquiring the resistance have appeared and have been studied. The pan-azole cases also exist and represent a challenge for them to be successfully treated without mortality involved. It has always been thought is the cycle only included the environment and the human being. But one important question remains, is if animals play a role in the cycle of transmission. This thesis is a beginning step, in the research of isolates of Azole-Resistant A. fumigatus present in the respiratory tissue of the most affected species in Veterinary Medicine, birds. Respiratory tissues from poultry (Gallus Gallus Domesticus) obtained in a slaughter house in the Utrecht province and a common seagull (Larus Canus) from the North-Holland province in the Netherlands were macroscopically analysed, manipulated in three diverse ways and then cultured at several temperatures. 19 A. fumigatus isolates were obtained from poultry and 1 from the seagull. All isolates were put through a resistant experiment. Along with resistant and susceptible strains obtained by Jianhua Zhang, all isolates were cultivated in Malt Agar, Malt Agar with itraconazole at 4 mg/ml and Malt Agar with Tebuconazole at 4mg/ml. The diameter of the colony was measured several days later, with at least three consecutive measurements done. They all presented a higher response to Tebuconazole than to Itraconazole, being none of them fully resistant. Further research can address molecular mechanisms involved in this kind of response. Resumen: Aspergillus fumigatus es un hongo muy conocido en la medicina porque es responsable de la aspergilosis invasiva (AI) en pacientes inmunocomprometidos. El uso de antifúngicos para esta enfermedad, en particular los azoles, había dado un buen resultado hasta la aparición de la primera aspergilosis resistente a azol en 1997. Desde entonces, han aparecido y se han estudiado más casos con diferentes mecanismos de adquisición de la resistencia. Los casos de resistencia a varios azoles también existen y representan un desafío para que puedan ser tratados con éxito sin la mortalidad involucrada. Siempre se ha pensado que el ciclo solo incluía el medio ambiente y el ser humano. Pero una pregunta importante que queda es si los animales juegan un papel en el ciclo de transmisión. Esta tesis es un paso inicial, en la investigación de aislamientos de A. fumigatus resistentes a Azoles presentes en el tejido respiratorio de las especies más afectadas en Medicina Veterinaria, las aves. Los tejidos respiratorios des aves de corral (Gallus Gallus Domesticus) obtenidos en un matadero en la provincia de Utrecht y una gaviota común (Larus Canus) de la provincia de Holanda Septentrional en los Países Bajos se analizaron macroscópicamente, se manipularon de tres maneras diferentes y luego se cultivaron a varias temperaturas. En total 19 aislamientos de A. fumigatus se obtuvieron de aves de corral y 1 de la gaviota. Todos los aislamientos se sometieron a un experimento resistente. Junto con las cepas resistentes y susceptibles obtenidas por Jianhua Zhang, todos los aislamientos se cultivaron en agar de malta, agar de malta con itraconazol a 4 mg / ml y agar de malta con tebuconazol a 4 mg / ml. El diámetro de la colonia se midió varios días después, con al menos tres mediciones consecutivas. Todos presentaron una respuesta más alta al tebuconazol que al itraconazol, ninguno de ellos era totalmente resistente. Investigación adicional puede abordar los mecanismos moleculares implicados en este tipo de respuesta.