Activity

The Mediterranean tick, Hyalomma marginatum, is the most important vector of Crimean-Congo haemorrhagic fever virus and several pathogens that cause animal and human diseases and economic losses to livestock production. Given the medical and veterinary importance of this tick species, we sequenced and characterized its mitochondrial genome (mitogenome) for the first time. We designed two new primer sets and combined long-range PCR with next generation sequencing to generate complete mitogenomes with deep coverage from 10 H. marginatum adults. Decumbin The mitogenomes contained 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), two ribosomal subunits, two control regions, and three tick-box motifs. The nucleotide composition of the H. marginatum mitogenomes were A+T biased (79.76%) and exhibited negative AT- and GC- skews across most PCGs. All PCGs were initiated by ATK codons and two truncated termination codons were seen in the COX2 and COX3 genes. All tRNAs exhibited typical cloverleaf structures, except for tRNACys and tRNASer1. A total of 62 polymorphic sites defined ten unique haplotypes. Phylogenetic analyses based on the 13 PCGs of 56 tick species revealed that four Hyalomma species (H. marginatum, H. asiaticum, H. rufipes, and H. truncatum) formed a monophyletic clade with strong support. The results of this study provide a comprehensive resource for further studies on the systematics, population genetics, molecular epidemiology, and evolution of ticks.Establishing and maintaining tick colonies in the laboratory is essential for studying their biology and pathogen transmission, or for the development of new tick control methods. Due to their requirement for very high humidity, these laboratory-bred colonies are frequently subject to fungal contamination. In the present study, we aimed to identify the fungal species that contaminated a laboratory-reared colony of Ixodes ricinus through microscopic observation and molecular identification. We identified three different taxa isolated from the ticks Aspergillus parasiticus, Penicillium steckii, and Scopulariopsis brevicaulis. These three species are usually regarded as environmental saprophytic molds but both direct and indirect evidence suggest that they could also be considered as entomopathogenic fungi. Although we do not have any direct evidence that the fungi isolated from I. ricinus in this study could cause lethal infections in ticks, we observed that once infected, heavy fungal growth coupled with very high mortality rates suggest that studying the entomopathogenic potential of these fungi could be relevant to biological tick control.Successfully navigating the world requires avoiding boundaries and obstacles in one’s immediately-visible environment, as well as finding one’s way to distant places in the broader environment. Recent neuroimaging studies suggest that these two navigational processes involve distinct cortical scene processing systems, with the occipital place area (OPA) supporting navigation through the local visual environment, and the retrosplenial complex (RSC) supporting navigation through the broader spatial environment. Here we hypothesized that these systems are distinguished not only by the scene information they represent (i.e., the local visual versus broader spatial environment), but also based on the automaticity of the process they involve, with navigation through the broader environment (including RSC) operating deliberately, and navigation through the local visual environment (including OPA) operating automatically. We tested this hypothesis using fMRI and a maze-navigation paradigm, where participants navigated two maze structures (complex or simple, testing representation of the broader spatial environment) under two conditions (active or passive, testing deliberate versus automatic processing). Consistent with the hypothesis that RSC supports deliberate navigation through the broader environment, RSC responded significantly more to complex than simple mazes during active, but not passive navigation. By contrast, consistent with the hypothesis that OPA supports automatic navigation through the local visual environment, OPA responded strongly even during passive navigation, and did not differentiate between active versus passive conditions. Taken together, these findings suggest the novel hypothesis that navigation through the broader spatial environment is deliberate, whereas navigation through the local visual environment is automatic, shedding new light on the dissociable functions of these systems.Population genetic studies have clearly indicated that immunity and host defense are among the functions most frequently subject to natural selection, and increased our understanding of the biological relevance of the corresponding genes and their contribution to variable immune traits and diseases. Herein, we will focus on some recently studied forms of human adaptation to infectious agents, including hybridization with now-extinct hominins, such as Neanderthals and Denisovans, and admixture between modern human populations. These studies, which are partly enabled by the technological advances in the sequencing of DNA from ancient remains, provide new insight into the sources of immune response variation in contemporary humans, such as the recently reported link between Neanderthal heritage and susceptibility to severe COVID-19 disease. Furthermore, ancient DNA analyses, in both humans and pathogens, allow to measure the action of natural selection on immune genes across time and to reconstruct the impact of past epidemics on the evolution of human immunity.

The widely used World Health Organization (WHO) Health Economic Assessment Tool (HEAT) for walking and cycling quantifies health impacts in terms of premature deaths avoided or caused as a result of changes in active transport. This article attempts to assess the effect of incorporating ‘life-years’ as an impact measure to increase the precision of the model and assess the effect on the tool’s usability.

This article is a methods paper, using simulation to estimate the effect of a methodological change to the HEAT 4.2 physical activity module.

We use the widely used WHO HEAT for walking and cycling as a case study. HEAT currently quantifies health impacts in terms of premature deaths avoided or caused as a result of changes in active transport. We assess the effect of incorporating “duration of life gained” as an impact measure to increase the precision of the model without substantially affecting usability or increasing data requirements.

Compared with the existing tool (HEAT version 4.2), which values premature deaths avoided, estimates derived by valuing life-years gained are more sensitive to the age of the population affected by an intervention, with results for older and younger age groups being markedly different between the two methods.