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Salicylic acid and Azospirillum brasilense stimulate plant growth and productivity. In some environments, plant physiology similarly responds to both bioactive products. Considering this, a field experiment was conducted to study the physiological effect of Salicilic acid and A. brasilense on growth and grain yield of maize plants. The experiment involved three treatments consisting of imbibed seeds in an aqueous solution of SA (0.01 mM), inoculated seeds with A. brasilense and a control treatment. Seed imbibition in SA and inoculation with A. brasilense improved vegetative growth in the early stages of crop ontogeny, increasing leaf growth, plant height, stem diameter and biomass accumulation. Spikelet length and weight were greater in plants first inoculated with A. brasilense and then treated with SA. Results indicated that SA stimulated biomass partitioning towards leaves, root and stem, while A. brasilense mainly affected leaf growth, plant height, ear dimensions and grain yield. Such results turn crucial for biological fertilization strategies aimed at reducing pollutant loads that accompany chemical fertilizers. Both products can be part of maize management practices given competitive economic advantages and sustainability. Highlights: • Seed imbibition in SA and inoculation with brasilense improved vegetative growth in the early stages of crop ontogeny, increasing leaf growth, plant height, stem diameter and biomass accumulation. • Salicylic Acid stimulated biomass partitioning towards leaves, root and stem in maize plants. • Azospirillum brasilense stimulates leaf growth, plant height, as well as ear dimensions and grain yield in corn plants.

La tercera parte de los suelos del mundo son ácidos, en estas condiciones muchos cultivos se afectan, sobre todo cuando las concentraciones de aluminio alcanzan niveles tóxicos. Con el objetivo de establecer las relaciones entre indicadores de acidez y la capacidad de intercambio catiónico, el pH y el contenido de materia orgánica, se seleccionaron 13 sitios en las regiones Frailesca y Valles Zoque. Se tomaron cinco sub-muestras a 0.30 m de profundidad, para luego conformar una muestra homogénea por sitio experimental. Se determinaron el pH, cationes intercambiables, capacidad de intercambio catiónico, contenido de materia orgánica, saturación de aluminio (Al3+) y de hidrógeno (H+). El porcentaje de saturación del Al3+ se correlacionó exponencialmente con incrementos en la CIC, el pH y el % de saturación del calcio (Ca2+); sin embargo, respecto a la materia orgánica, la saturación de Al3+ se ajustó significativamente a un modelo polinomial de segundo grado, indicando un máximo de saturación a valores de 4.14% de materia orgánica. El porcentaje de saturación de H+ se ajustó negativamente a una función exponencial, disminuyendo a valores de materia orgánica superiores a 2%. Se concluye que en los suelos de la región Frailesca se está produciendo un proceso de acidificación que pudiera conducir a incrementos tóxicos del aluminio para el cultivo de maíz, sobre todo a valores de pH inferiores a cinco. Tales incrementos en la acidificación de los suelos pudieran estar asociados al excesivo uso de fertilizantes amoniacales producto de una agricultura mucho más intensiva que en la región Valles Zoques.

Seeds of Raphanus sativus L. var. Champion were inoculated with commercial strains of rhizospheric fungi+bacteria. A completely randomized experiment was designed with four treatments: Chromobacterium violaceum+Acinetobacter calcoaceticus (BiofosfoBuap®, T1), Azospirillum brasilense (AzoFer), Glomus intraradices (MicorrizaFer), and uninoculated control. Each treatment had 20 replicates. The objective was to evaluate the effect of the different treatments on leaf growth, taproot length and dry weight, dry weight of leaves and tubers, and fresh tuber weight. Net assimilation rate (NAR), absolute growth rate (AGR), and relative growth rate (RGR) were calculated. Thirty three days after sowing (das), plants inoculated with C. violaceum+A. calcoaceticus had 52.67% more leaf area than the control, and 42 das they had 72.30% more leaf area. Thirty three das, treatments with C. violaceum+A. calcoaceticus and A. brasilense had 49.66% and 45.52% more dry leaf weight than the control. Fresh weight of tubers for the same two treatments was 65.03% and 63.11% higher than the control 33 das, respectively, and 80.70% and 74.56% higher 42 das. Co-inoculation with C. violaceum+A. calcoaceticus and inoculation with A. brasilense alone promoted growth of radish tubers as a consequence of increased leaf area and biomass as well as an increase in net assimilation rate. Highlights The effect of rhizosphere bacteria and fungi on the leaf area of radish plants depends more on the leaves size than on the leaves number produced by the plant. The better growth observed in plants inoculated with C. violaceum + A. calcoaceticus and A. brasilense might depend on the greater plant hormone synthesis. The effects of C. violaceum + A. calcoaceticus on plant growth are better than a single microorganism inoculation and such effects depend on the enhanced co-inoculation. Inoculating plants with C. violaceum + A. calcoaceticus promotes the tuber biomass increase over the taproot growth. Inoculation with C. violaceum + A. calcoaceticus induces transfer of photosynthates from above ground part of the plant to the tuber in order to produce biomass. Inoculation with C. violaceum + A. calcoaceticus favored accumulation of biomass in leaves and tubers, resulting in total plant biomass production, although not taproot length.

This research was carried out in Villaflores and Villa Corzo, located in Chiapas State of Mexico. Specifically, throughout an ethno-agronomical approach, semi-structured interviews were designed and applied to the chayote producers who were selected by random routes. The results indicate the 57.89% of chayote producers in both municipalities, have allowed to control weeds in their crops, and being a higher proportion represented by Villaflores. Given these concerns, they prefer to control weeds throughout traditional methods, basically using mattocks with frequencies of 15 to 30 days after sowing or two to four times per cycle of crop production. Both pest and diseases are mainly controlled throughout chemical methods application. A preference to perform control among periods of higher rainfall or drought is not distinguished. A considerable percentage, which reaches 44% of the interviewed population among both municipalities, report they do not need to control pests and crop diseases.

Las políticas de desarrollo han sido utilizadas como instrumentos hegemónicos para legitimar formas de dependencia y justificar la depredación de los recursos naturales, de tal forma, que le otorga características distintivas a las políticas de desarrollo de México a nivel del Gobierno federal y estatal. Este artículo plantea la perspectiva de la construcción estratégica de las políticas del desarrollo en México, desde un análisis de tendencias comparativas con las estrategias de los planes de desarrollo de Chiapas, abordado en términos de la participación del Estado, enfoque sobre el uso y manejo de los recursos naturales y la relación con poblaciones indígenas.

In Egypt, the lyophilized live attenuated sheep pox virus vaccine has been used for the vaccination of cattle against lumpy skin disease virus to control its economic impact on livestock industry. In this endeavor, we validate the efficacy of Carbopol® as a stabilizer and adjuvant to enhance immunogenicity of such a heterologous sheep pox virus vaccine against lumpy skin disease. Lyophilization of sheep pox virus vaccine stabilized with Carbopol® produced better physical and antigenic properties than freeze-drying with lactalbumin/sucrose stabilizer; this was manifested by superior disc uniformity, thermo-stability at 37oC, and less reduction in virus titer. Immunization of calves' groups with variable sheep pox vaccine doses containing different Carbopol® concentrations revealed that 103.5 TCID50 of sheep pox virus vaccine enclosing 0.5% Carbopol® is the field dose of choice. Moreover, it induced protective serum neutralizing index of 2.5 and a ELISA S/P ratio of 36, by the 4th week post vaccination. Besides, the inclusion of 0.5% Carbopol® in formulation of the sheep pox virus vaccine was safe in bovines and enhanced cellular immune response to lumpy skin disease virus, as evidenced by increased T cell proliferation. Hence, it is recommended to use Carbopol® as 0.5% in preparation of live attenuated sheep pox virus vaccine to confer better protection against lumpy skin disease virus infection.

Introducción: Las estrategias vacunales para potenciar respuestas de linfocitos T CD8+ citotóxicos (CTL) constituyen un reto debido a la necesidad de favorecer la presentación cruzada de antígenos (Ag) exógenos por las células presentadoras de antígenos (APC). Con este propósito se han empleado liposomas que encapsulan proteínas formadoras de poros (PFP) de origen bacteriano. Objetivo: explorar la habilidad de liposomas que co-encapsulan el Ag ovoalbúmina (OVA) y sticholysina II (StII), una PFP producida por Stichodactyla helianthus, de inducir una respuesta de CTL, funcional en un modelo tumoral. Métodos: Liposomas que co-encapsulaban OVA y StII se prepararon mediante deshidratación-rehidratación (Lp/OVA/StII). Se evaluó la respuesta de CTL, así como la actividad antitumoral en un escenario preventivo. La capacidad de StII de estimular la maduración de las células dendríticas (DC) in vitro fue también explorada. Resultados: Lp/OVA/StII potenció la respuesta de CTL específica a OVA y una actividad antitumoral en ratones retados con el tumor E.G7-OVA. StII indujo la maduración de las DC in vitro, lo que resultó dependiente del receptor tipo Toll 4 (TLR4), con una contribución en la respuesta de CTL inducida por la formulación liposomal in vivo. Lp/OVA/StII favoreció in vitro la presentación cruzada de OVA y la activación de células T CD8+ por macrófagos, pero no por DC. Estos resultados son la primera evidencia de que StII encapsulada en liposomas funciona como una plataforma vacunal para inducir una respuesta de CTL robusta, con una contribución que va más allá de su habilidad de formar poros en membranas.

En este artículo se presenta un análisis de la transformación paulatina de la economía alimentaria lacandona, a partir de su contexto histórico, político y cultural. Esta economía ha sido particularmente de subsistencia, con patrones caracterizados por sus formas de apropiación y uso de los recursos naturales de la selva lacandona. Para comprender dichas formas se realizaron procesos de investigación participativa y microsociológica con el propósito de identificar cada una de las fuentes de abastecimiento de alimentos y los sistemas de producción y preparación. Si bien estas formas de vida pueden considerarse sustentables y saludables, dada su economía alimentaria han tendido a ser transformadas y a cambiar su organización. La colonización y la política social construidas verticalmente no han dado cabida a las realidades locales que podrían redituar, bajo su esquema alimentario y de subsistencia, condiciones de bienestar y salud. En este sentido, se revisan los objetivos y el enfoque de los programas de orden social y el Programa Nacional México Sin Hambre en la comunidad lacandona. Este análisis refleja el vacío de estos planes de Gobierno, que no solo desconocen las realidades locales, sino que además legitiman una serie de elementos de poder que implican una transformación que puede atentar contra el patrimonio cultural. Las políticas de desarrollo del Gobierno federal mexicano son asumidas en línea vertical hacia todos los niveles, con una orientación incisiva en estrategias que alteran las formas de vida de las comunidades indígenas y en su relación con los ecosistemas, al dar por hecho un contexto de problemas locales concebido desde un deber ser. De esa manera, las políticas remueven la estructura y organización de las poblaciones, pues generan ajustes en las sinergias sociales, dinamizadas a través de las redes de relaciones, construidas y deconstruidas que se sustentan en un conjunto de significaciones locales.

Con el objetivo de estimar la biomasa y el carbono acumulado en bosques de pino (Pinus maximinoii), encino (Quercus rugosa), roble (Quercus robur) y ocote (Pinus patula), en 1 ejidos de la región Frailesca de Chiapa, se seleccionaron 22 parcelas de 500 m2 (dos por cada ejido); en las que se determinaron la altura (H), la edad (años) y el diámetro normalizado (DN) de 358 árboles. Se ajustaron ecuaciones de regresión entre la biomasa acumulada (BMt) y la edad de cada árbol. Los ajustes resultaron estadísticamente significativos para el modelo exponencial y=b·ec·x. Se demuestra que, a partir de la edad del árbol, es posible estimar la biomasa total acumulada y que la mayor acumulación, tanto de biomasa como de carbono, se produjo en los bosques de pino y la menor en los de roble, debido a su estado fisiológico determinado por la menor edad del arbolado. Los bosques de pino registraron un almacén de 158 Mg ha-1, seguido del encino con 17 Mg ha-1. La especie que menos carbono almacenó fue el roble con 5.9 Mg ha-1. De los sitios estudiados, los bosques del ejido “24 de Febrero” presentaron mayor captura potencial de carbono.

This investigation aims to study the use of gamma irradiation for keeping the quality of cows’ butter. Fresh butter samples were exposed to gamma irradiation at doses of 0, 2.5 and 5 kGy followed by refrigerated storage and the effects of these treatments on the microbiological aspects and lipid characteristics of butter samples were studied. Moreover, fatty acid profiles and unsaponifiable matter constituents were determined by gas chromatographic analysis, while the stability of butter was determined by rancimat. The results indicated that gamma irradiation at 2.5 kGy dose reduced the counts of total bacteria, lipolytic bacteria, coliforms, molds and yeasts, however, these counts gradually increased during cold storage. Also irradiation at 5 kGy dose greatly reduced the total bacterial count which gradually increased upon storage, while completely eliminated the other determined microorganisms. Irradiation treatments increased the acid value and peroxide value of butter, while the iodine number was not altered. Moreover, gas chromatographic analysis showed that gamma irradiation slightly increased the total volatile fatty acids, total saturated fatty acids and total hydrocarbons, while slightly decreased the total unsaturated fatty acids and total sterols. In addition, irradiation of butter decreased its stability as determined by rancimat and upon storage of both irradiated and non irradiated butter samples, the acid value gradually increased, while a flexuous changes in the peroxide value were observed. The present study proved that 2.5 and 5 kGy gamma irradiation doses could keep the quality of cows’ butter and increased its shelf life at 4±1ºC for 8 and 12 weeks as compared to 4 weeks for non irradiated butter (based on the visual appearance of mold growth on the surface of samples) without any effects on its sensory properties.

This study evaluated some changes occurring in double fractionated (DF) palm olein during heating. DF palm olein was heated at 180°C for 60 hr (4hr/day) with no added source of water. Heated oil samples were analyzed for refractive index (Rl), viscosity, colour change, dielectric constant change (DCC), acid value (AV), peroxide value (PV), iodine value (IV) and unsaponifiable matter (UM) constituents. The results indicated that, viscosity, colour, DCC and AV gradually increased, while IV gradually decreased with increasing heating time. The study showed also that heating times correlated with increases in DCC, viscosity and AV. PV increased ca 17-fold, reached a maximum at 16 hr, then gradually decreased to remain relatively constant through the last 20 hr of heating. Chromatographic analysis illustrated that UM components changed qualitatively and quantitatively due to the heating treatment.