Semen collection using electroejaculation and sperm parameters in pacas (Cuniculus paca, Linnaeus, 1766)

ABSTRACT Pacas (Cuniculus paca) are highly hunted animals because of the flavor of their meat, and commercial breeding is recommended. However, this species has a relatively low reproductive rate. This study aimed to collect semen from pacas through electroejaculation and obtain the sperm parameters of this species for the first time. Seven male pacas were used, submitted to an anesthetic protocol before stimulation by an electroejaculator appropriate for the species. The stimulus protocol was performed in three series: series I, 10 stimuli with 1 and 2 V; series II, 10 stimuli with 3 and 4 V; and series III, 10 stimuli with 5 V and interval between series of 2 s. The collected material was evaluated for color, volume, motility, vigor, and concentration. The sperm parameters collected showed a mean volume of 0.43±0.33 mL, concentration of 45.5±42.44×106 sperm/mL, motility of 33.33±32.14%, and mean vigor of 2.6±1.15. In this study, the anesthetic protocol did not seem to favor semen collection by electroejaculation in the pacas. The electrical stimulation protocol was able to stimulate all animals in the study; however, there were few samples with sperm cells and a low rate of motility and vigor in most ejaculates

Force transmissibility and vibration power flow behaviour of inerter-based vibration isolators

This paper investigates the dynamics and performance of inerter-based vibration isolators. Force / displacement transmissibility and vibration power flow are obtained to evaluate the isolation performance. Both force and motion excitations are considered. It is demonstrated that the use of inerters can enhance vibration isolation performance by enlarging the frequency band of effective vibration isolation. It is found that adding inerters can introduce anti-resonances in the frequency-response curves and in the curves of the force and displacement transmissibility such that vibration transmission can be suppressed at interested excitation frequencies. It is found that the introduction of inerters enhances inertial coupling and thus have a large influence on the dynamic behaviour at high frequencies. It is shown that force and displacement transmissibility increases with the excitation frequency and tends to an asymptotic value as the excitation frequency increases. In the high-frequency range, it was shown that adding inerters can result in a lower level of input power. These findings provide a better understanding of the effects of introducing inerters to vibration isolation and demonstrate the performance benefits of inerter-based vibration isolators

Avaliação da eficiência de cal virgem na inativação de ovos de nematoides - Strongyloides sp.) parasitos de pacas - Cuniculus paca ) criadas em cativeiro

RESUMO Criadores de animais silvestres sempre buscam métodos eficientes de manter sua criação. Parasitos intestinais afetam os animais em cativeiro, diminuindo sua sobrevivência e reprodução. Este estudo teve como objetivo avaliar a eficácia do uso de cal virgem na desinfecção do solo e na prevenção da reinfestação de endoparasitos em pacas (Cuniculus paca) em cativeiro. Amostras de solo das baias de criação foram analisadas usando-se o método de Rugai modificado. Duas etapas foram avaliadas: a primeira aos cinco, 45 e 105 minutos após os tratamentos, e a segunda aos sete dias e aos 14 dias após os tratamentos. Os valores de pH das amostras foram verificados após a aplicação de quatro tratamentos. Foram aplicados 400g/m2 de cal virgem a lanço ou 500mL/m2 de três soluções de cal virgem (10%, 20% ou 40% p/v). Na primeira etapa, a cal a lanço foi ineficaz na modificação do pH do solo e no controle de parasitos. A solução a 10% proporcionou o melhor controle dos parasitos. Na segunda etapa, as soluções foram eficazes na elevação do pH, porém não houve diferença significativa nos achados larvais. Concluiu-se que, nas condições do estudo, a solução a 10% aumentou o pH do solo e teve boa capacidade de inativação dos ovos de Strongyloides sp., o que economicamente é interessante. Porém, para o controle eficiente de Strongyloides sp. em cativeiros de pacas, deve-se considerar a frequência da aplicação de soluções com até 20% de cal, juntamente com a adoção de um programa de vermifugação

Comparative genomics of Beauveria bassiana : Uncovering signatures of virulence against mosquitoes

Background: Entomopathogenic fungi such as Beauveria bassiana are promising biological agents for control of malaria mosquitoes. Indeed, infection with B. bassiana reduces the lifespan of mosquitoes in the laboratory and in the field. Natural isolates of B. bassiana show up to 10-fold differences in virulence between the most and the least virulent isolate. In this study, we sequenced the genomes of five isolates representing the extremes of low/high virulence and three RNA libraries, and applied a genome comparison approach to uncover genetic mechanisms underpinning virulence. Results: A high-quality, near-complete genome assembly was achieved for the highly virulent isolate Bb8028, which was compared to the assemblies of the four other isolates. Whole genome analysis showed a high level of genetic diversity between the five isolates (2.85-16.8 SNPs/kb), which grouped into two distinct phylogenetic clusters. Mating type gene analysis revealed the presence of either the MAT1-1-1 or the MAT1-2-1 gene. Moreover, a putative new MAT gene (MAT1-2-8) was detected in the MAT1-2 locus. Comparative genome analysis revealed that Bb8028 contains 163 genes exclusive for this isolate. These unique genes have a tendency to cluster in the genome and to be often located near the telomeres. Among the genes unique to Bb8028 are a Non-Ribosomal Peptide Synthetase (NRPS) secondary metabolite gene cluster, a polyketide synthase (PKS) gene, and five genes with homology to bacterial toxins. A survey of candidate virulence genes for B. bassiana is presented. Conclusions: Our results indicate several genes and molecular processes that may underpin virulence towards mosquitoes. Thus, the genome sequences of five isolates of B. bassiana provide a better understanding of the natural variation in virulence and will offer a major resource for future research on this important biological control agent