Guía Pedagógica: Producción de Cultivos Forrajeros

Guía pedagógic

CULTIVOS UTILIZADOS COMO FORRAJE EN MEXICO

SÓLO VISIÓN PROYECTABLE

Hidrogenación selectiva de fenilacetileno en Pd/Al₂O₃ efecto de la adición de Pt, del tamaño de partícula y envenenamiento

Se estudio la hidrogenaci6n selectiva de fenilacetileno en catalizadores de Pd/n1203, el efecto de adicidn de Pt, el tamatio de particula en la actividad y 8el.ctivid.d tanto en catalizadores soportados Alzo3 como sio2 y por Ultimo el envenenamiento con (UB,) y tiofeno. La dirprsibn metalica (%O) se determid por gravimotrla utilizando el m4todo de titulaci6n hidr6geno-oxlgeno. Los dil[metros pramedio de partlcula fueron determinados por Kicroscopla Electr6nica en un equipo de transmisi6n Jeol 1OOCX. La deterainaci6n de la actividad catalltica se llevo a cabo en un reactor diferencial a baja conversibn (45%) en la mayoria de los casos. Las condiciones de reacci6n fueron la8 siguientes: Presibn parcial del fenilacetileno de 6.6 torr, preai6n parcial de hidr4geno 760 torr, masa del catalizador 0.050-0.015 gr. y temperatura de reaccibn 45%. xn base a los resultados concluimos que: a) la actividad del Pd es mayor que la del Pt en catalizadores soportados en &120,, mientras que la selectividad hacia estireno es menor en Pd que en Pt, probablemente a la menor formaci6n de reeiduos carbonaceos en la superficie, e1 cual e. mayor en Pts b) m los catalizadores Pt-Pd/Alz03 re observo un efecto de segregacibn del Pt a contenidos 2 35% de Pt; c) La actividad en los catalizadores Pt/nlp3, Pd/A1203 y Pd/SiOz no se ven afectados por el tanmilo de partlcula, ni se observa efecto de soporte en la Selectividad del Pd en hluIC3 6 Si02; d) €lay un aumento de la selectividad en funcidn del timpo, debido a que se depositan especies oligom4ricas; e) La selectividad inicial en catalizadore. enmnenados de baja dispersi6n es menor que en catalizadores M envenenados; f) Los catalitadores envenenados con

Crime trends through two decades of social changes in Spain

"Over the last two decades, the Spanish social fabric has undergone a variety of profound changes, which in turn may explain the rise in police-recorded crime and prison population figures. Although the rise in crime reported to the police has been higher for common offences—misdemeanors—, the mainstream media concentrates overwhelmingly in serious violent crimes—felonies—. Spain does not have an official agency responsible for conducting victimization surveys to measure crime trends as directly experienced by the citizens. Based on this methodology, our study shows that contrary to information gathered from police data, and despite social fabric changes, crime in Spain is decreasing. The present study also reveals the distorted public perception of this trend, which seems to respond to a repetitive coverage of serious crime by the mainstream media." [author's abstract

Neotropical tadpoles: spatial and temporal distribution and habitat use in a seasonal lake in Veracruz, México

We studied a tadpole assemblage in a seasonal neotropical lake where 14 species of anurans reproduce. Tadpoles were collected monthly at nine sampling stations at depth intervals of 1 m from the surface to the bottom (13 m). Sufficient numbers of tadpoles of three species were collected to compare habitat use. This three species assemblage breed in the following order (first to last): Smilisca baudinii, Gastrophryne usta, and Rana berlandieri. R. berlandieri had the greatest microhabitat breadth followed by S. baudinii. S. baudinii and G. usta had high microhabitat overlap, but significant differences in microhabitat use were found. S. baudinii tended to occur near the bottom, while G. usta was near the surface. This study shows that temporal and habitat partitioning both occur and depend on the species of tadpole. Dynamic interactions occur between habitat and temporal dimensions. Phenology and habitat selection depend both on the species and on abiotic and biotic factors

The role of distinctive sphingolipids in the inflammatory and apoptotic effects of electronegative LDL on monocytes

Altres ajuts: Fundació La Marató de TV3: 158/U/2017Electronegative low-density lipoprotein (LDL(−)) is a minor LDL subfraction that is present in blood with inflammatory and apoptotic effects. We aimed to evaluate the role of sphingolipids ceramide (Cer), sphingosine (Sph), and sphingosine-1-phosphate (S1P) in the LDL(−)-induced effect on monocytes. Total LDL was subfractioned into native LDL and LDL(−) by anion-exchange chromatography and their sphingolipid content evaluated by mass spectrometry. LDL subfractions were incubated with monocytes in the presence or absence of enzyme inhibitors: chlorpromazine (CPZ), D-erythro-2-(N-myristoyl amino)-1-phenyl-1-propanol (MAPP), and N,N-dimethylsphingosine (DMS), which inhibit Cer, Sph, and S1P generation, respectively. After incubation, we evaluated cytokine release by enzyme-linked immunosorbent assay (ELISA) and apoptosis by flow cytometry. LDL(−) had an increased content in Cer and Sph compared to LDL(+). LDL(−)-induced cytokine release from cultured monocytes was inhibited by CPZ and MAPP, whereas DMS had no effect. LDL(−) promoted monocyte apoptosis, which was inhibited by CPZ, but increased with the addition of DMS. LDL enriched with Sph increased cytokine release in monocytes, and when enriched with Cer, reproduced both the apoptotic and inflammatory effects of LDL(−). These observations indicate that Cer content contributes to the inflammatory and apoptotic effects of LDL(−) on monocytes, whereas Sph plays a more important role in LDL(−)-induced inflammation, and S1P counteracts apoptosis

Optimizing Safety Stock Levels in Modular Production Systems Using Component Commonality and Group Technology Philosophy: A Study Based on Simulation

Modular production and component commonality are two widely used strategies in the manufacturing industry to meet customers growing needs for customized products. Using these strategies, companies can enhance their performance to achieve optimal safety stock levels. Despite the importance of safety stocks in business competition, little attention has been paid to the way to reduce them without affecting the customer service levels. This paper develops a mathematical model to reduce safety stock levels in organizations that employ modular production. To construct the model, we take advantage of the benefits of aggregate inventories, standardization of components, component commonality, and Group Technology philosophy in regard to stock levels. The model is tested through the simulation of three years of operation of two modular product systems. For each system, we calculated and compared the safety stock levels for two cases: (1) under the only presence of component commonality and (2) under the presence of both component commonality and Group Technology philosophy. The results show a reduction in safety stock levels when we linked the component commonality with the Group Technology philosophy. The paper presents a discussion of the implications of each case, features of the model, and suggestions for future research

Presence of Ceramidase Activity in Electronegative LDL

Ceramide; SphingomyelinaseCeramida; EsfingomielinasaCeramida; EsfingomielinasaElectronegative low-density lipoprotein (LDL(−)) is a minor modified fraction of human plasma LDL with several atherogenic properties. Among them is increased bioactive lipid mediator content, such as lysophosphatidylcholine (LPC), non-esterified fatty acids (NEFA), ceramide (Cer), and sphingosine (Sph), which are related to the presence of some phospholipolytic activities, including platelet-activating factor acetylhydrolase (PAF-AH), phospholipase C (PLC), and sphingomyelinase (SMase), in LDL(−). However, these enzymes’ activities do not explain the increased Sph content, which typically derives from Cer degradation. In the present study, we analyzed the putative presence of ceramidase (CDase) activity, which could explain the increased Sph content. Thin layer chromatography (TLC) and lipidomic analysis showed that Cer, Sph, and NEFA spontaneously increased in LDL(−) incubated alone at 37 °C, in contrast with native LDL(+). An inhibitor of neutral CDase prevented the formation of Sph and, in turn, increased Cer content in LDL(−). In addition, LDL(−) efficiently degraded fluorescently labeled Cer (NBD-Cer) to form Sph and NEFA. These observations defend the existence of the CDase-like activity’s association with LDL(−). However, neither the proteomic analysis nor the Western blot detected the presence of an enzyme with known CDase activity. Further studies are thus warranted to define the origin of the CDase-like activity detected in LDL(−).This research was funded by grants PI13/00364, PI16/00471, FIS PI019/00421, and PI20/00334 from the Instituto de Salud Carlos III, Spanish Ministry of Health (co-financed by the European Regional Development Fund). N.P. is the recipient of FI20/00252 from Instituto de Salud Carlos III. This research was supported by CIBER (Consorcio Centro de Investigación Biomédica en Red) (CB07/08/0016), Instituto de Salud Carlos III, and Ministerio de Ciencia e Innovación and Unión Europea—European Regional Development Fund. CIBERDEM (CB07/08/0016) and CIBERCV (CB16/11/00257) are Instituto de Salud Carlos III Projects. A.A.-S. is member of RETICS INVICTUS PLUS (RD16/0019/0010, the Instituto de Salud Carlos III project). N.P., S.B., N.R., and J.L.S.-Q. are members of the Quality Research Group 2017-SGR-1149 from Generalitat de Catalunya and the Group of Vascular Biology of the Spanish Society of Atherosclerosis

Presence of Ceramidase Activity in Electronegative LDL

Electronegative low-density lipoprotein (LDL(−)) is a minor modified fraction of human plasma LDL with several atherogenic properties. Among them is increased bioactive lipid mediator content, such as lysophosphatidylcholine (LPC), non-esterified fatty acids (NEFA), ceramide (Cer), and sphingosine (Sph), which are related to the presence of some phospholipolytic activities, including platelet-activating factor acetylhydrolase (PAF-AH), phospholipase C (PLC), and sphingomyelinase (SMase), in LDL(−). However, these enzymes' activities do not explain the increased Sph content, which typically derives from Cer degradation. In the present study, we analyzed the putative presence of ceramidase (CDase) activity, which could explain the increased Sph content. Thin layer chromatography (TLC) and lipidomic analysis showed that Cer, Sph, and NEFA spontaneously increased in LDL(−) incubated alone at 37 °C, in contrast with native LDL(+). An inhibitor of neutral CDase prevented the formation of Sph and, in turn, increased Cer content in LDL(−). In addition, LDL(−) efficiently degraded fluorescently labeled Cer (NBD-Cer) to form Sph and NEFA. These observations defend the existence of the CDase-like activity's association with LDL(−). However, neither the proteomic analysis nor the Western blot detected the presence of an enzyme with known CDase activity. Further studies are thus warranted to define the origin of the CDase-like activity detected in LDL(−)