Effect of phenological stages on yield, chemical composition and biological properties of essential oil from Thymus maroccanus Ball.

The effects of phenological stages on the composition, antioxidant, insecticidal and allelopathic properties of essential oils (EOs) obtained from the aerial parts of Thymus maroccanus Ball. were evaluated. The GC-MS analysis identified that analyzed EOs were dominated by carvacrol (63.70 - 68.19 %) followed by p-cymene (6.09 - 9.67 %) and γ-terpinene (3.67 - 8.49 %). When carvacrol and p-cymene gradually increased from the lowest values (63.70% and 6.09%) at the pre-flowering stage to reach the highest ones (68.19% and 9.67%) at post-flowering stage, γ-terpinene gradually decreased from the highest proportion (8.49%) to the lowest (3.67%). EO from post-flowering aerial parts showed higher scavenging ability on DPPH radicals (% inhibition: 25.19 - 95.75 %; IC50 = 0.26 mg/mL), in contrast, the essential oil from pre-flowering stage exhibited the highest Fe3+ reducing power ability (Absorbance:  0.329 - 0.812; IC50 = 0.14 mg/mL). Insecticidal properties showed no substantial difference between T. maroccanus EO extracted at different growth stages. The LD50 and LD90 values were ranged from 0.15 to 0.17 µL/cm2, and from 0.37 to 0.47 µL/cm2, respectively in contact assays, as well as from 318.93 to 362.84 µL/L air, and from 725.08 to 739.12 µL/L air, respectively in fumigant assays. The results indicated that allelopathic activity of Eos is not greatly affected by growth developmental stages.

La auditoría social en el centro del cambio tecnológico y organizativo

Con el auge de las nuevas tecnologías y los proyectos informáticos, ha surgido una nueva era en el mundo empresarial actual, conocida comúnmente como transformación digital. Ésta responde a las nuevas necesidades de las empresas en cuanto a la dirección de los resultados financieros de sus actividades en un entorno volátil. Así, el éxito de cualquier transformación requiere un cambio profundo en los procesos de la empresa e incluso en su cultura. Este artículo tiene un doble objetivo: por un lado, pretende presentar el impacto de la transformación digital en los resultados financieros a partir de los trabajos teóricos y los modelos desarrollados sobre el tema. Por otro lado, también pretende destacar la importancia del componente de RRHH en cualquier proyecto de transformación digital, análisis que se realizará apoyándose en la auditoría social de las organizaciones, cuya importancia sigue creciendo en el contexto de la digitalización. De hecho, se presentará como una palanca para el éxito del diálogo social en el contexto actual, y un federador que garantiza la adhesión de los recursos humanos al cambio digital.  En consonancia con las teorías del uso y la construcción social de las soluciones tecnológicas, el cambio digital participa en la estrategia digital de las organizaciones desempeñando un papel estructurador, y garantizará la consecución del objetivo último de la transformación digital, que es el rendimiento financiero de la empresa

Composition and Nitrogen Distribution of Ouled-Djellal and Rumbi Algerian Ewe's Milk

Abstract: The chemical composition and nitrogen distribution of milk from two ewe's breed (Ouled-Djellal and Rumbi) (n = 20 each) reared in Algerian area steppe, were studied. The ewes were balanced for age and weight. All were in middle period of lactation. Individual milk samples were taken from each ewe third time from lactating period during spring season. Rumbi ewe's milk gave the highest values (p≤0.01) for lactose (4.89±0.61%), solid non-fat (11.19±0.87%) and density (1037.57±3.78) than Ouled-Djellal ewes (4.38±0.45%, 10.24±0.77% 1033.82±2.59, respectively) and lowest values (p≤0.01) for freezing point (-0.57±0.05°C vs -0.53±0.02°C). No significant difference was observed between the two breeds on fat, protein, total solids. The mean percentages were 6.26±1.38%, 5.54±0.76 and 16.51±1.44%, respectively for Ouled-Djellal ewes, while those of Rumbi's were 5.66±3.52%, 5.91±1.10% and 16.85±3.32%, respectively. No statistical differences related to the breed were found in the milk for all nitrogen fractions. Rumbi ewe's milk contains about 1.01% nitrogen however Ouled-Djellal's hold about 0.96%. Total nitrogen content is distributed between non-protein nitrogen (0.09% in all breeds) and protein nitrogen (0.93 vs 0.87% for Rumbi and Ouled -Djellal ewes respectively). The protein nitrogen includes casein nitrogen (0.76 vs 0.71) and whey protein nitrogen (0.20 vs 0.19%) from Rumbi and Ouled-Djellal ewes, respectively. Algerian sheep breeds were not actually selected for their milk production; selection program should be implemented to improve milk production and increase fat and protein contents. Thus further studies should carry out on milk ability and milk yield of these breeds

Rotational energy transfer in collisions between CO and Ar at temperatures from 293 to 30 K

Experimental measurements and theoretical calculations are reported for rotational energy transfer in the Ar-CO system. Experiments were performed in cold uniform supersonic flows of Ar, using an infrared – vacuum ultraviolet double resonance technique to measure absolute state-to-state rate constants and total relaxation cross sections for rotational energy transfer within the (v = 2) vibrational state of CO in collision with Ar at temperatures from 30.5 to 293 K. Close-coupling calculations were also performed using a recent potential energy surface (Sumiyoshi and Endo, 2015). Very good agreement is obtained between measured and calculated values