A thorough investigation of the antiferromagnetic resonance.

Antiferromagnetic (AF) compounds possess distinct characteristics that render them promising candidates for advancing the application of spin degree of freedom in computational devices. For instance, AF materials exhibit minimal susceptibility to external magnetic fields while operating at frequencies significantly higher than their ferromagnetic counterparts. However, despite their potential, there remains a dearth of understanding, particularly concerning certain aspects of AF spintronics. In particular, the properties of coherent states in AF materials have received insufficient investigation, with many features extrapolated directly from the ferromagnetic scenario. Addressing this gap, this study offers a comprehensive examination of AF coherent states, shedding new light on both AF and Spin-Flop phases. Employing the Holstein-Primakoff formalism, we conduct an in-depth analysis of resonating-driven coherent phases. Subsequently, we apply this formalism to characterize antiferromagnetic resonance, a pivotal phenomenon in spin-pumping experiments, and extract crucial insights therefrom.

Evaluation of sperm and hormonal assessments in Wagyu, Nellore, and Angus bulls.

Wagyu bulls are known to have a highly exacerbated libido, as shown by the intense sexual interest of young calves. Therefore we believe that Wagyu male animals have specialized Sertoli and Leydig cells that are directly involved with the sexual precocity in this breed as mature bulls have a small scrotal circumference. This study aimed to evaluate whether there were differences in the hormone and sperm characteristics of Wagyu bulls compared with the same characteristics of subspecies Bos indicus and Bos taurus sires. Frozen-thawed semen from Wagyu, Nellore, and Angus sires were analyzed for sperm kinetics (computer-assisted sperm analysis), plasma membrane integrity, chromatin integrity, acrosome status, mitochondrial activity, lipid peroxidation and hormone [luteinizing hormone (LH) and testosterone] serum concentration. The results showed that Wagyu had lower total motility and an increased number of sperm with no motility when compared with Nellore and Angus bulls. Wagyu breed did not differ from those breeds when considering plasma and acrosome membranes integrity, mitochondrial potential, chromatin resistance, sperm lipid peroxidation or hormone (LH and testosterone) concentrations. We concluded that Wagyu sires had lower total motility when compared with Nellore and Angus bulls. Wagyu breed did not differ from these breeds when considering plasma and acrosome membranes integrity, mitochondrial potential, chromatin resistance, sperm lipid peroxidation, or hormone (LH and testosterone) concentrations.

On the dissipative coherent states of magnons.

Research in spintronics has attracted much attention in the last few years due to the technological progress in generating and manipulating spin currents in miniaturized devices. Notwithstanding dissipative effects are inherent to experiments, in many theoretical works the damping of spin waves is included later by phenomenological arguments or even disregarded. Among the many techniques that have been used to treat magnetic models, bosonic representations is one of them. In this work, we chose the Holstein-Primakoff bosonic formalism to treat a ferromagnetic model with a priori inclusion of the damping term. Damping is included through a non-Hermitian term in the Hamiltonian and we showed that the well-known coherent state formalism can be generalized to properly represent the dissipative magnon model. The obtained results are then used to describe the precession magnetization in spintronic experiments, as the spin pumping process.

Avaliaçäo do volume corrente de ar em cäes submetidos a toracotomia em bloco / Evaluation of current volume of air in dogs submitted to thoracotomy in the lump

Doze cäes, divididos em dois grupos, foram submetidos a toracotomia em bloco. Constatou-se, além da eficiência do protocolo anestésico, que o método cirúrgico näo provoca alteraçöes evidentes da mecânica respiratória, sendo indicado para os casos que necessitem de ampla exposiçäo cirúrgica