“INFLUENCE OF SUNFLOWER OIL AND Schizochytrium microalgae ON RUMINAL METHANE AND CARBON DIOXIDE EMISSIONS OF TOTAL MIXED RATION IN STEERS

La producción ganadera contribuye con alrededor del 18% de metano (CH⁴) y el 9% de las emisiones de dióxido de carbono (CO²) de producción, que se han implicado en causar el cambio climático. El metano, CO², hidrógeno (H²) son los principales gases producidos durante la fermentación ruminal, lo que provoca una pérdida de 2 a 12% de la energía de la dieta de los rumiantes (Johnson y Johnson, 1995). Mejorar la utilización de piensos y el rendimiento animal es el principal objetivo de los nutricionistas; Sin embargo, deben considerarse las obligaciones sociales y ambientales para reducir las emisiones de gases de efecto invernadero (GEI). Se han utilizado estrategias nutricionales incluyendo levadura (Elghandour et al., 2017), sal de ácidos orgánicos (Elghandour et al., 2016), enzimas exógenas y aceites esenciales para controlar la producción de metano ruminal de los rumiantes (Kholif et al., 2017B)

Calculation Evidence of Staged Mott and Peierls Transitions in VO₂ Revealed by Mapping Reduced-Dimension Potential Energy Surface

Unraveling the metal–insulator transition (MIT) mechanism of VO₂ becomes tremendously important for understanding strongly correlated character and developing switching applications of VO₂. First-principles calculations were employed in this work to map the reduced-dimension potential energy surface of the MIT of VO₂. In the beginning stage of MIT, a significant orbital switching between σ-type d_<i>z</i>² and π-type d_{<i>x</i>²–<i>y</i>²}/d_<i>yz</i> accompanied by a large V–V dimerization and a slight twisting angle change opens a band gap of ∼0.2 eV, which can be attributed to the electron-correlation-driven Mott transition. After that, the twisting angle of one chain quickly increases, which is accompanied by the appearance of a larger change in band gap from 0.2 to 0.8 eV, even though orbital occupancy is maintained. This finding can be ascribed to the structure-driven Peierls transition. The present study reveals that a staged electron-correlation-driven Mott transition and structure-driven Peierls transition are involved in MIT of VO₂

Clarifying the Roles of Oxygen Vacancy in W‑Doped BiVO₄ for Solar Water Splitting

Most oxide semiconductor photoanode materials for water splitting are synthesized in ambient environment. Oxygen vacancy exists in these samples making them intrinsically n-type at the as-synthesized state. Oxygen vacancy has been widely reported for enhancing the performance of a photoanode by improving the electron conductivity. Besides the effect on the bulk materials properties, oxygen vacancy also plays an important role in the interfacial charge transfer to electrolyte, on which much less attention has been paid in the past. Herein, we found that although air-annealed W-doped BiVO₄ has a higher electron density, lower surface charge transfer resistance, and a slightly better light absorption than the O₂-annealed sample, the latter displays a higher photocurrent density. Experimentally we found that the enhanced performance comes from a better charge separation efficiency, despite that the presence of oxygen vacancy does lead to a better charge transfer efficiency. Theoretical calculation finds that there is a localized state formed inside the bandgap in W-doped BiVO₄ with oxygen vacancy, which serves as recombination center to reduce its charge separation efficiency. Oxygen vacancy on the V site activates two different kinds of V into reactive sites for improved surface catalysis. Oxygen vacancy also facilitates the adsorption of the OH_ads, O_ads, and OOH_ads involved in a water splitting process, which benefits the surface catalytic process. It is predicted from this study that better performance can be achieved by introducing oxygen vacancy on the surface of a doped BiVO₄ and simultaneously avoiding oxygen vacancy in the bulk. The current study provides an important understanding of the roles played by oxygen vacancy in doped photoanode materials

The Influence of Diurnal Temperature Variation on Degree-Day Accumulation and Insect Life History

<div><p>Ectotherms, such as insects, experience non-constant temperatures in nature. Daily mean temperatures can be derived from the daily maximum and minimum temperatures. However, the converse is not true and environments with the same mean temperature can exhibit very different diurnal temperate ranges. Here we apply a degree-day model for development of the grape berry moth (<i>Paralobesia viteana</i>, a significant vineyard pest in the northeastern USA) to investigate how different diurnal temperature range conditions can influence degree-day accumulation and, hence, insect life history. We first consider changes in diurnal temperature range independent of changes in mean temperatures. We then investigate grape berry moth life history under potential climate change conditions, increasing mean temperature via variable patterns of change to diurnal temperature range. We predict that diurnal temperature range change can substantially alter insect life history. Altering diurnal temperature range independent of the mean temperature can affect development rate and voltinism, with the magnitude of the effects dependent on whether changes occur to the daily minimum temperature (<i>Tmin</i>), daily maximum temperature (<i>Tmax</i>), or both. Allowing for an increase in mean temperature produces more marked effects on life history but, again, the patterns and magnitude depend on the nature of the change to diurnal temperature range together with the starting conditions in the local environment. The study highlights the importance of characterizing the influence of diurnal temperature range in addition to mean temperature alone.</p></div

Synthesis of Tri- and Tetrasubstituted Pyrazoles via Ru(II) Catalysis: Intramolecular Aerobic Oxidative C–N Coupling

An unprecedented ruthenium(II)-catalyzed intramolecular oxidative C–N coupling method has been developed for the facile synthesis of a variety of synthetically challenging tri- and tetrasubstituted pyrazoles. Dioxygen gas is employed as the oxidant in this transformation. The reaction demonstrates excellent reactivity, functional group tolerance, and high yields

Iterations of the four non-rigid registration algorithms.

<p>The convergence of our algorithm takes 40 iterations, while the CPD algorithm takes about 50 iterations and the TPS-L2 algorithm and the TPS-RPM algorithm takes more than 50 iterations.</p

Deformation vectors of central points.

<p>(a) Our algorithm, (b) CPD, (c) TPS-L2, (d) TPS-RPM. The deformation vectors produced by our algorithm are more regularized than the ones produced by CPD, and the registration result of our algorithm is more accurate than TPS-L2 and TPS-RPM. Some deformation vectors produced by CPD were crossed, which broke the topological structure of the point sets. The aligned point set was too smooth to fit the CSF boundary points by using TPS-RPM.</p

BINAPHANE-Catalyzed Asymmetric Synthesis of <i>trans</i>-β-Lactams from Disubstituted Ketenes and <i>N</i>-Tosyl Arylimines

The development of a BINAPHANE-catalyzed formal [2 + 2]-cycloaddition of disubstituted ketenes and inexpensive <i>N</i>-tosyl arylimines that provides access to a variety of highly substituted β-lactams (16 examples) is described. The BINAPHANE catalytic system displays moderate to excellent enantioselectivity (up to 98% ee) and high diastereoselectivity in most cases, favoring formation of the <i>trans</i>-diastereomer (13 examples with dr ≥ 90:10)

BINAPHANE-Catalyzed Asymmetric Synthesis of <i>trans</i>-β-Lactams from Disubstituted Ketenes and <i>N</i>-Tosyl Arylimines

The development of a BINAPHANE-catalyzed formal [2 + 2]-cycloaddition of disubstituted ketenes and inexpensive <i>N</i>-tosyl arylimines that provides access to a variety of highly substituted β-lactams (16 examples) is described. The BINAPHANE catalytic system displays moderate to excellent enantioselectivity (up to 98% ee) and high diastereoselectivity in most cases, favoring formation of the <i>trans</i>-diastereomer (13 examples with dr ≥ 90:10)

Number of Generations of <i>P</i>. <i>viteana</i> under Same Mean with Various DTR Change Conditions.

<p>Note: The dots represnet mean number of generations (voltinism) with error bars represent standard errors. The lines represent linear regression of voltinism against <i>k</i> values for both locations. The slopes of both regression lines are highly significant (<i>p</i><0.01), indicating a strong increasing trend of voltinism with larger DTRs.</p