Influence of Omega-3 fatty acids on the learning ability of the Guide Dog during the training

Some studies show the usefulness of supplementation with long chain poliunsatured fatty acids (LCPUFA) in puppies during training through the evaluation of the ability of learning and memory. The purpose of this preliminary study was to evaluate the effect of DHA supplementation on learning abilities in a group of future Guide Dogs for the Blind during the phases of education and training. Two groups of six Labrador dogs (A, study group and B, control group), belonging to School of Guide Dogs of Tuscany (Italy), random selected, were included in the study. To evaluate the effect of supplementation, we used the standardized tests of the School as they are internationally recognized and can establish both character and learning skills of puppies. Some differences were observed between the two groups in some tests results; in particular in those that require a greater visual and sensory capacity and motor coordination as the grid (or abnormal surface) test and the tilting table test. The results obtained in this study could confirm the usefulness of a 35 mg/kg DHA supplementation during the first year of life for improving cognitive skills in dogs

The conservation of native honey bees is crucial

Recent studies have emphasized the role of the western honey bee, Apis mellifera, as a managed agricultural species worldwide, but also as a potential threat to endangered wild pollinators. This has resulted in the suggestion that honey bees should be regulated in natural areas to conserve wild pollinators. We argue that this perspective fails to appreciate the multifaceted nature of honey bees as native or introduced species with either managed or wild colonies. Wild populations of A. mellifera are currently imperiled, and natural areas are critical for the conservation of local subspecies and genotypes. We propose that a differentiation between managed and wild populations is required and encourage integrated conservation planning for all endangered wild bees, including A. mellifera.http://www.cell.com/trends/ecology-evolution/home2020-09-01hj2020Zoology and Entomolog

Cardiac Electrophysiological Effects of Light-Activated Chloride Channels

During the last decade, optogenetics has emerged as a paradigm-shifting technique to monitor and steer the behavior of specific cell types in excitable tissues, including the heart. Activation of cation-conducting channelrhodopsins (ChR) leads to membrane depolarization, allowing one to effectively trigger action potentials (AP) in cardiomyocytes. In contrast, the quest for optogenetic tools for hyperpolarization-induced inhibition of AP generation has remained challenging. The green-light activated ChR from Guillardia theta (GtACR1) mediates Cl−-driven photocurrents that have been shown to silence AP generation in different types of neurons. It has been suggested, therefore, to be a suitable tool for inhibition of cardiomyocyte activity. Using single-cell electrophysiological recordings and contraction tracking, as well as intracellular microelectrode recordings and in vivo optical recordings of whole hearts, we find that GtACR1 activation by prolonged illumination arrests cardiac cells in a depolarized state, thus inhibiting re-excitation. In line with this, GtACR1 activation by transient light pulses elicits AP in rabbit isolated cardiomyocytes and in spontaneously beating intact hearts of zebrafish. Our results show that GtACR1 inhibition of AP generation is caused by cell depolarization. While this does not address the need for optogenetic silencing through physiological means (i.e., hyperpolarization), GtACR1 is a potentially attractive tool for activating cardiomyocytes by transient light-induced depolarization

Ancient and recent differences in the intrinsic susceptibility of Mycobacterium tuberculosis complex to pretomanid

OBJECTIVES: To develop a robust phenotypic antimicrobial susceptibility testing (AST) method with a correctly set breakpoint for pretomanid (Pa), the most recently approved anti-tuberculosis drug. METHODS: The Becton Dickinson Mycobacterial Growth Indicator Tube™ (MGIT) system was used at six laboratories to determine the MICs of a phylogenetically diverse collection of 356 Mycobacterium tuberculosis complex (MTBC) strains to establish the epidemiological cut-off value for pretomanid. MICs were correlated with WGS data to study the genetic basis of differences in the susceptibility to pretomanid. RESULTS: We observed ancient differences in the susceptibility to pretomanid among various members of MTBC. Most notably, lineage 1 of M. tuberculosis, which is estimated to account for 28% of tuberculosis cases globally, was less susceptible than lineages 2, 3, 4 and 7 of M. tuberculosis, resulting in a 99th percentile of 2 mg/L for lineage 1 compared with 0.5 mg/L for the remaining M. tuberculosis lineages. Moreover, we observed that higher MICs (≥8 mg/L), which probably confer resistance, had recently evolved independently in six different M. tuberculosis strains. Unlike the aforementioned ancient differences in susceptibility, these recent differences were likely caused by mutations in the known pretomanid resistance genes. CONCLUSIONS: In light of these findings, the provisional critical concentration of 1 mg/L for MGIT set by EMA must be re-evaluated. More broadly, these findings underline the importance of considering the global diversity of MTBC during clinical development of drugs and when defining breakpoints for AST

Integrating standardized whole genome sequence analysis with a global Mycobacterium tuberculosis antibiotic resistance knowledgebase.

Drug-resistant tuberculosis poses a persistent public health threat. The ReSeqTB platform is a collaborative, curated knowledgebase, designed to standardize and aggregate global Mycobacterium tuberculosis complex (MTBC) variant data from whole genome sequencing (WGS) with phenotypic drug susceptibility testing (DST) and clinical data. We developed a unified analysis variant pipeline (UVP) ( https://github.com/CPTR-ReSeqTB/UVP ) to identify variants and assign lineage from MTBC sequence data. Stringent thresholds and quality control measures were incorporated in this open source tool. The pipeline was validated using a well-characterized dataset of 90 diverse MTBC isolates with conventional DST and DNA Sanger sequencing data. The UVP exhibited 98.9% agreement with the variants identified using Sanger sequencing and was 100% concordant with conventional methods of assigning lineage. We analyzed 4636 publicly available MTBC isolates in the ReSeqTB platform representing all seven major MTBC lineages. The variants detected have an above 94% accuracy of predicting drug based on the accompanying DST results in the platform. The aggregation of variants over time in the platform will establish confidence-graded mutations statistically associated with phenotypic drug resistance. These tools serve as critical reference standards for future molecular diagnostic assay developers, researchers, public health agencies and clinicians working towards the control of drug-resistant tuberculosis