CsCuCl3 perovskite-like compound under extreme conditions

Halide perovskite has attracted intense research interest owing to its multifaceted and versatile applications in optoelectronics. This intrigue is further fueled by their propensity to undergo intricate structural modifications under extreme conditions, thereby instigating property changes. Within this context, our study delves deep into the intricate interplay of structural and vibrational attributes within the inorganic-metal halide perovskite-like CsCuCl3. Our approach employs Raman spectroscopy and Synchrotron Powder X-Ray Diffraction (SPXRD) techniques harnessed under the dual conditions of low temperatures and high pressures. We have observed a distinct spin-phonon coupling mechanism by employing Raman spectroscopy at low temperatures; this coupling has been manifested as a renormalization phonon phenomenon that occurs notably at T* = 15 K. The correlation between spin and phonon dynamics becomes pronounced through a notable hardening of phonon temperature dependence, a behavior intricately linked to the material antiferromagnetic transition at TN = 10.7 K. The SPXRD under high pressure showed a first-order structural phase transition (SPT) at the critical pressure Pc = 3.69 GPa, leading to the transformation from the hexagonal P6522 to a base-centered monoclinic cell. Notably, the coexistence of both phases is discernible within the pressure range from 2.79 to 3.57 GPa, indicating that the SPT involves the reorganization of the internal [Cu2Cl9]5- dimer unit, with the Cl-Cu-Cl bending contributing more than stretching modes. Furthermore, we demonstrate that the SPT is reversible, but residual strain pressure influences the modification of the critical pressure Pc value upon pressure decrease.Comment: 27 pages, 8 figure

Ovos de cigarrinhas-das-pastagens: comparação de eficiência de amostragem em relação ao tamanho das amostras

The sampling efficiency of three sample units was compared to determine spittlebug egg densities in pastures of Brachiaria decumbens Stapf. To obtain the same level of precision, the total pasture area to be examined increased by 1.5 times when size of the sample unit was increased from 75 to 150 cm2, and by 2.5 times when it was increased to 225 cm2 . Using the 75cm2 unit, the number of samples necessary for 10%, 15% and 20% levels of precision were estimated to be 170, 82 and 48, respectively. The distribution pattern of egg counts per 75 cm2 of the pasture, fitted the negative binomial series. A study of sampling variation within 1 ha pastures, showed that differences between blocks, or plots within blocks were significant only in about 20% instances. Nevertheless, choosing of well-distributed sampling sites within the sampling area was suggested.Foram comparados três diferentes tamanhos de amostras em relação à eficiência da amostragem para se determinar a densidade de ovos de cigarrinhas em pastagens de Brachiaria decumbens Stapf. Para se obter um mesmo nível de precisão, a área de pastagem a ser examinada aumentou 1,5 vez quando o tamanho da unidade de amostragem aumentou de 75 para 150cm2 e de 2,4 vezes quando o aumento foi para 225cm2. Uma estimativa mostrou a necessidade de 170 amostras para se obter um nível de 10% de precisão, 82 para 15% e 48 para 20%. O número de ovos por unidade de 75cm2 de área de pastagem mostrou uma distribuição do tipo binomial negativa. Um estudo sobre a variação na amostragem nas áreas de 1 ha de pastagens mostrou que as diferenças entre os blocos, ou parcelas dentro dos blocos, foram significativas somente em cerca de 20% dos casos. Contudo, tomada de amostras bem distribuídas dentro da área de amostragem foi sugerida

Growth efficiency of Nellore cattle in the growing and finishing phases.

The objective of this work was to evaluate the growth efficiency of Nellore young bulls in the growing and fattening phases using the Kleiber index (KI). The experiment was carried out in the ABCZ experimental farm Orestes Prata Tibery Júnior, located at the MG-427 highway, Uberaba, MG, Brazil (lat. 19º 47´ 68´´ S; long. 47º 58' 50'' W, 788 m asl). The local climate is tropical semi-humid presenting mean air temperature of 21.4°C, annual rainfall of 1,684 mm and relative humidity of 71.4%. Young bulls (n = 101) were submitted to 280 days of evaluation under grazing in Brachiaria brizantha cv. BRS Paiaguás pastures, 140 days during the wet season and 140 days during the dry season, measuring the weight of the animals and the average daily live weight gain (ADG). After this period, in the feedlot, the same animals were maintained in pens with automated troughs for 109 days to measure live weight and individual intake. It was estimated the feed efficiency (FE), the residual feed intake (RFI), the feed intake (FI), the dry matter intake (DMI) and the KI, dividing the average daily gain (ADG) by the average metabolic live weight (AMLW). Data were analyzed with Pearson's correlation at P < 0.05 using the software Action. Correlated data were observed for Kleiber index (KI) and FI (0.62), and for KI and ADG (0.86). The correlation between KI and gross FE was significant (P < 0.01) and of strong magnitude, with a value of 0.79. The KI did not correlated with RFI (0.012), but correlated negatively with FI (-0.80). There was no correlation between ADG, AMLW and KI, when the values obtained from cattle maintained at different phases were analyzed. Kleiber index can be used as a tool for animal selection in the feedlot, as it has high correlation with ADG and FE. However, studies on the Kleiber Index are still needed to validate this hypothesis, especially with regard to the selection of animals based only on the efficiency presented in confinement and how it will reflect on animals kept under the grazing system that is the most used in this country

Feed efficiency of dairy Gir heifers in the feedlot.

The objective of the study was to evaluate the feed efficiency of Gir heifers in the feedlot through the residual feed intake (RFI) evaluation. The experiment was carried out on the campus of Faculdades Associadas in Uberaba, MG, Brazil. It was evaluated 43 dairy Gir heifers from the Genetic Breeding Program of EPAMIG, with initial age and mean live weight of 20 months and 279 kg, respectively (Ethics Committee approval of Epamig: 02/2020). Heifers were housed in a feedlot containing electronic troughs and weighing scales. The experimental period lasted 91 days with 21 of adaptation and 70 days of evaluation, from 12/26/2020 to 03/27/2021. The diet was formulated to provide 0.450 kg LW/head/day and had a forage:concentrate ratio of 74:26, with 76.4% of corn silage and 23.6% of concentrate, containing 8.3% of crude protein (CP) and 64.8% of total digestible nutrients (TDN) on dry matter (DM) basis. The RFI was determined and then two experimental heifer groups were formed, a positive RFI and a negative RFI. They were compared in terms of average daily gain (ADG), feed conversion (FC), daily dry matter intake (DMI), and gross feed efficiency (GFE). The experimental design was completely randomized and means were compared using Tukey test at 5% of significance. In the evaluation of heifers, 24 had negative RFI and 19 positive RFI. About 56% of the heifers had lower DMI compared to estimated, of which considered more efficient. There was a difference (P0.05) for ADG (0.45 and 0.44 kg LW/head/day), FC (15.4 and 13.2 kg DM/kg ADG), GFE (0.07 and 0.08 kg ADG/kg DMI), respectively for negative and positive RFI. Consequently, negative RFI heifers consume less with the same live weight gain, allowing better-feed conversion in the rearing phase, reducing feed quantity and costs of milk production. This fact is proven trough the reduction of necessary inputs for feeding during the rearing, impacting in reducing the cost of the production system and indirectly the cost of milk production

Feed efficiency of Nellore young bull in the feedlot.

The objective of the study was to evaluate feed efficiency of Nellore young bull in the feedlot using the evaluation of the residual feed intake (RFI). The experiment was carried out at the experimental farm Orestes Prata Tibery Júnior (ABCZ), located in Uberaba, MG, Brazil (lat. 19º 47' 68" S.; long. 47º 58' 50'' W, 788 m West). Nellore young bulls (n = 101), pure breed, with initial age of 17 months and mean live weight of 486 kg were housed in a feedlot containing electronic troughs and weighing scales. The experimental period lasted 98 days, with 28 of adaptation and 70 days of evaluation, from 03/17/2021 to 06/23/2021. The diet was formulated to provide 1.700 kg live weight/head/day and had a forage:concentrate ratio of 40:60, with 40% of corn silage and 60% of concentrate, containing 15.3% CP and 76.8% TDN on dry matter (DM) basis. The RFI was determined during the experimental period and the animals were separated in two experimental groups: positive and negative RFI. It was evaluated average daily gain (ADG), feed conversion (FC), daily dry matter intake (DMI) and gross feed efficiency (GFE). The experimental design was completely randomized and means were compared using Tukey test at 5% significance. In the evaluation of 101 young bulls, 56 had negative RFI and 45 had positive RFI, about 55.4% had lower DMI compared to estimated, which was considered the most efficient. The difference between the lowest and the highest individual intake followed was -1.87 kg (negative RFI) and 3.52 kg (positive RFI), with the difference of 5.39 kg of RFI, showing variability and chance of selection for more efficient and lower cost young bulls. It was observed effect of youn bull RFI group on DMI - 13.59 and 12.05 kg/day, and 2.51 and 2.24% LW, respectively for positive and negative RFI. There was a reduction of 11.3% in DMI during the experimental period. Feed conversion (6.28 and 6.93 kg of DM/kg ADG for negative and positive RFI) and GFE (0.16 and 0.15 kg ADG/kg DMI for negative and positive RFI) were influenced by RFI group. There was no effect (P>0.05) of RFI group on ADG - 1.95 (negative RFI) and 1.98 kg/head/day (positive RFI). Young bulls presenting negative RFI had lower intake with the same ADG, enabling better-feed conversion in the finishing phase, which directly affects the reduction of feed and production costs

Avaliação de cultivares de soja, sob manejo orgânico, para fins de adubação verde e produção de grãos.

O objetivo deste trabalho foi avaliar o desempenho de seis cultivares de soja, sob manejo orgânico, para fins de adubação verde e produção de grãos. Utilizou-se delineamento experimental de blocos casualizados, com quatro repetições por tratamento (cultivar). Na época da colheita, 81 dias após a emergência das plântulas, todas as cultivares testadas (Celeste, Surubi, Campo Grande, Mandi, Lambari e Taquari) mostraram excelente nodulação, variando de 545 a 760 mg/planta de massa nodular seca. As cultivares Celeste e Taquari, que produziram, respectivamente, 8,33 e 7,12 t ha-1 de biomassa seca da parte aérea, apresentaram outras características agronômicas vantajosas, tais como: ciclo curto, alta acumulação de nutrientes (N, P, K, Ca e Mg) nos tecidos verdes e bom rendimento de sementes. Esses caracteres indicam potencial de 'Celeste' e 'Taquari' para adubação verde de verão em sistemas de agricultura orgânica. Cinco das cultivares avaliadas revelaram tendência ao acamamento, porém dentro de níveis aceitáveis. As cultivares Celeste, Surubi, Campo Grande, Mandi e Taquari suplantaram em 23%, 32%, 33%, 44% e 70%, respectivamente, a média nacional de produtividade de soja, estimada em 2.398 kg ha-1 nas últimas três safras

Improving postcryopreservation survival capacity: an embryo-focused approach.

The major challenge for a greater dissemination of in vitro produced (IVP) bovine embryos is to improve embryonic survival after cryopreservation. The involvement of embryonic lipids on this issue is well documented. However, it has been recognized that not only the amount of lipids that affects embryo cryotolerance, but the embryo survival capacity after cryopreservation is a rather multifactorial event. In this review, some strategies to improve embryonic lipid composition and postcryopreservation survival by modifying the embryos themselves to make them more cryopreservable are overviewed. The use of semi-defined and defined serum-free culture media, the addition of some chemicals in the culture media to modify embryo lipid composition, and the modulation of embryo cell membrane fluidity by cholesterol or unsaturated fatty acids added to the culture media and oocyte/embryo donor nutritional management with a diet enriched in polyunsaturated fatty acids, were described as alternatives for the improvement of IVP embryo survival after cryopreservation