Reemplazo de una pradera permanente y su efecto en el primer año en una lechería comercial

The objective was to assess the impact of replacing a permanent pasture with a reseeded pasture on system productivity and product quality in the first year of establishment under commercial conditions management. Dairy cows were allocated to treatment based on pasture availability at the start of the season following standard commercial practices. Seventy autumn-calved cows grazed a high sugar grass pasture (14.1 ha reseeded in September 2015) and 55 grazed a permanent pasture (12.1 ha) from April to June 2016. Pastures snip samples were taken to assess nutritional composition every two weeks. Milk production and composition was measured on 4th May and 10th June. A slightly higher content of water soluble carbohydrate was observed in May on the reseeded sward (27.1 vs. 25.8%) coinciding with a higher milk yield (24.6 vs. 22.9 L d-1 per cow), lactose content (4.41 vs. 4.34%), and a lower somatic cell account (59,400 vs. 113,300 cell mL-1), compared to the permanent pasture. Pasture varied in nutritional value across the study. In June, no differences in milk production or composition were observed. However, the reseeded sward was estimated to produce 12.3% more milk per ha than the permanent pasture during the experimental period (113.8 vs. 101.3 L ha-1 d-1), driven by the greater carrying capacity of the sward (5 vs. 4.5 LU ha-1). This farm case study shows the potential of a reseeded pasture to outperform permanent pasture even in the first year of establishment at a farm system scale

Radical Trifluoromethylation of Sc\u3csub\u3e3\u3c/sub\u3eN@C\u3csub\u3e80\u3c/sub\u3e

The addition of CF3 radicals to both the I (h) and D (5h) cage-isomers Of SC3N@C-80 by high-temperature reaction of the metallic nitride fullerenes with gaseous CF3I has resulted in the isolation Of SC3N@(C-80-I (h))(CF3)2 and SC3N@(C-80-D (5h))(CF3)(2), which have idealized C-2 and C-s symmetry, respectively. Both new compounds were characterized by F-19 NMR and electronic absorption spectroscopy, mass spectrometry, and quantum-chemical calculations at the DFT level of theory, and the I h cage derivative was also characterized by cyclic voltammetry. The results indicate that both compounds have a p -C-6(CF3)(2) hexagon with endohedral Sc atoms bonded to the sp(2) cage C atoms para to the sp(3) cage C-6(CF3) atoms

Sc\u3csub\u3e3\u3c/sub\u3eN@(C\u3csub\u3e80\u3c/sub\u3e-\u3cem\u3eI\u3c/em\u3e\u3csub\u3eh\u3c/sub\u3e(7))(CF\u3csub\u3e3\u3c/sub\u3e)\u3csub\u3e14\u3c/sub\u3e and Sc\u3csub\u3e3\u3c/sub\u3eN@(C\u3csub\u3e80\u3c/sub\u3e-\u3cem\u3eI\u3c/em\u3e\u3csub\u3eh\u3c/sub\u3e(7))(CF\u3csub\u3e3\u3c/sub\u3e)\u3csub\u3e16\u3c/sub\u3e. Endohedral Metallofullerene Derivatives with Exohedral Addends on Four and Eight Triple-Hexagon Junctions. Does the Sc\u3csub\u3e3\u3c/sub\u3eN Cluster Control the Addition Pattern or Vice Versa?

The compounds Sc3N@(C80-Ih(7))(CF3)14 (1) and Sc3N@(C80-Ih(7))(CF3)16 (2) were prepared by heating Sc3N@C80-Ih(7) and Ag(CF3CO2) to 350 °C in a sealed tube. The structures of 1 and 2 were determined by single-crystal X-ray diffraction. They are the first X-ray structures of any endohedral metallofullerene with more than four cage C(sp3) atoms. The structures exhibit several unprecedented features for metallic nitride fullerenes, including multiple cage sp3 triple-hexagon junctions (four on 1 and eight on 2), no cage disorder and little (2) or no (1) endohedral atom disorder, high-precision (C−C esd’s are 0.005 Å for 1 and 0.002 Å for 2), an isolated aromatic C(sp2)6 hexagon on 2, and two negatively charged isolated aromatic C(sp2)5− pentagons on 2 that are bonded to one of the Sc atoms. DFT calculations are in excellent agreement with the two Sc3N conformations observed for 2 (ΔE(calc) = 0.36 kJ mol−1; ΔE(exp) = 0.26(2) kJ mol−1)

Redox-Tuning Endohedral Fullerene Spin States: From the Dication to the Trianion Radical of Sc\u3csub\u3e3\u3c/sub\u3eN@C\u3csub\u3e80\u3c/sub\u3e(CF\u3csub\u3e3\u3c/sub\u3e)\u3csub\u3e2\u3c/sub\u3e in Five Reversible Single-Electron Steps

The first endohedral trianion captured: Sc3N@C80(CF3)2 (see figure) exhibits three reversible reductions and two reversible oxidations and affords the facile generation of the monocation, monoanion, and trianion in solution, which can be characterized by ESR and absorption spectroscopies. This is the first time that such a broad range of charged states of any endohedral fullerene has been spectroscopically characterized

Poly(perfluoroalkylation) of Metallic Nitride Fullerenes Reveals Addition-Pattern Guidelines: Synthesis and Characterization of a Family of Sc\u3csub\u3e3\u3c/sub\u3eN@C\u3csub\u3e80\u3c/sub\u3e(CF\u3csub\u3e3\u3c/sub\u3e)\u3csub\u3e\u3cem\u3en\u3c/em\u3e\u3c/sub\u3e (\u3cem\u3en\u3c/em\u3e=2â16) and Their Radical Anions

A family of highly stable (poly)perfluoroalky-lated metallic nitride cluster fullerenes was prepared in high-temperature reactions and characterized by spectroscopic (MS, 19F NMR, UV−vis/NIR, ESR), structural and electrochemical methods. For two new compounds, Sc3N@C80(CF3)10 and Sc3N@C80(CF3)12, single crystal X-ray structures are determined. Addition pattern guidelines for endohedral fullerene derivatives with bulky functional groups are formulated as a result of experimental (19F NMR spectroscopy and single crystal X-ray diffraction) studies and exhaustive quantum chemical calculations of the structures of Sc3N@C80(CF3)n (n = 2-16). Electrochemical studies revealed that Sc3N@C80(CF3)n derivatives are easier to reduce than Sc3N@C80, the shift of E1/2 potentials ranging from +0.11 V (n = 2) to +0.42 V (n = 10). Stable radical anions of Sc3N@C80(CF3)n were generated in solution and characterized by ESR spectroscopy, revealing their 45Sc hyperfine structure. Facile further functionalizations via cycloadditions or radical additions were achieved for trifluoromethylated Sc3N@C80 making them attractive versatile platforms for the design of molecular and supramolecular materials of fundamental and practical importance

Symmetric configurations highlighted by collective quantum coherence

Recent developments in quantum gravity have shown the Lorentzian treatment to be a fruitful approach towards the emergence of macroscopic spacetimes. In this paper, we discuss another related aspect of the Lorentzian treatment: we argue that collective quantum coherence may provide a simple mechanism for highlighting symmetric configurations over generic non-symmetric ones. After presenting the general framework of the mechanism, we show the phenomenon in some concrete simple examples in the randomly connected tensor network, which is tightly related to a certain model of quantum gravity, i.e., the canonical tensor model. We find large peaks at configurations invariant under Lie-group symmetries as well as a preference for charge quantization, even in the Abelian case. In future study, this simple mechanism may provide a way to analyze the emergence of macroscopic spacetimes with global symmetries as well as various other symmetries existing in nature, which are usually postulated.Comment: 19 pages, 4 figures; Major changes in the summary section. Some other minor changes. Figures replaced. References adde