Understanding and responding to the environmental human rights defenders crisis: the case for conservation action

Close to two thousand environmental human rights defenders have been killed in 57 countries since 2002, with about four losing their lives every week in 2019. Many of these defenders represent Indigenous Peoples and local communities protecting ecosystems from large-scale environmentally destructive projects. As the positive contributions of Indigenous and local communities to biodiversity conservation become better recognized, so should the losses and risks that they face. Despite major efforts at documenting abuses and protecting defenders, many blind spots and gaps remain. Here, we call for the conservation community to put the protection of defenders at the heart of its strategy to slow down and reverse the current onslaught on the environment. The conservation community can respond in a number of ways including reaching out to its constituencies, working together with the human rights community, and mobilizing its networks, field offices, and presence in remote areas to denounce abuses and counter isolation. In doing so the conservation community can advance the collective agenda bringing together conservation and environment-related human rights through the Post-2020 Global Biodiversity Framework

The xnp1 P2-Like Tail Synthesis Gene Cluster Encodes Xenorhabdicin and Is Required for Interspecies Competition ▿†

Xenorhabdus nematophila, the mutualistic bacterium of the nematode Steinernema carpocapsae, produces the R-type bacteriocin called xenorhabdicin, which is thought to confer a competitive advantage for growth in the insect host. We have identified a P2-like tail synthesis gene cluster (xnp1) that is required for xenorhabdicin production. The xnp1 genes were expressed constitutively during growth and were induced by mitomycin C. Deletion of either the sheath (xnpS1) or fiber (xnpH1) genes eliminated xenorhabdicin production. Production of R-type bacteriocins in a host organism had not been shown previously. We show that xenorhabdicin is produced in the hemocoel of insects infected with the wild type but not with the ΔxnpS1 deletion strain. Xenorhabdicin prepared from the wild-type strain killed the potential competitor Photorhabdus luminescens TT01. P. luminescens was eliminated during coculture with wild-type X. nematophila but not with the ΔxnpS1 strain. Furthermore, P. luminescens inhibited reproduction of S. carpocapsae in insect larvae, while coinjection with wild-type X. nematophila, but not the ΔxnpS1, strain restored normal reproduction, demonstrating that xenorhabdicin was required for killing P. luminescens and protecting the nematode partner. Xenorhabdicin killed X. nematophila from Steinernema anatoliense, demonstrating for the first time that it possesses intraspecies activity. In addition, activity was variable against diverse strains of Xenorhabdus and Photorhabdus and was not correlated with phylogenetic distance. These findings are discussed in the context of the role of xenorhabdicin in the life cycle of the mutualistic bacterium X. nematophila

Is Achilles tendon blood flow related to foot pronation?

In the etiology of Achilles tendinopathy (AT), it is frequently suggested that excessive pronation causes a vascular constriction of the Achilles tendon, described as the "whipping phenomenon" (Clement et al., 1984). Although previous studies focused on the association between pronation and AT, it is striking that the underlying association between foot pronation and blood flow has not been studied yet. Therefore, the aim of this study was to investigate whether the amount of pronation during running influences the Achilles tendon blood flow. Twenty-five experienced runners, aged 34.5±10.2 years, participated in this study. 2D-lower limb kinematics during barefoot and shod running in both frontal and sagittal plane were assessed. Blood flow of the Achilles tendon was measured before and after barefoot and shod running, using the oxygen-to-see device. The results of this study showed a significant effect of eversion excursion on the increase in Achilles tendon blood flow after shod running. More specifically, the more the eversion excursion observed, the lower the increase in blood flow (P=.013). We therefore suggest, in individuals with increased inversion at touchdown and increased eversion around midstance during shod running, that antipronation measures could be useful in both preventing and managing Achilles tendinopathy

A paleogenomic reconstruction of the deep population history of the Andes

There are many unanswered questions about the population history of the Central and South Central Andes, particularly regarding the impact of large-scale societies, such as the Moche, Wari, Tiwanaku, and Inca. We assembled genome-wide data on 89 individuals dating from ∼9,000-500 years ago (BP), with a particular focus on the period of the rise and fall of state societies. Today's genetic structure began to develop by 5,800 BP, followed by bi-directional gene flow between the North and South Highlands, and between the Highlands and Coast. We detect minimal admixture among neighboring groups between ∼2,000-500 BP, although we do detect cosmopolitanism (people of diverse ancestries living side-by-side) in the heartlands of the Tiwanaku and Inca polities. We also highlight cases of long-range mobility connecting the Andes to Argentina and the Northwest Andes to the Amazon Basin.Nathan Nakatsuka, Iosif Lazaridis, Chiara Barbieri ... Bastien Llamas ... Alan Cooper ... Wolfgang Haak ... et al

Crystal structure and functional characterization of OmpK36, the osmoporin of Klebsiella pneumoniae

BACKGROUND: Porins are channel-forming membrane proteins that confer solute permeability to the outer membrane of Gram-negative bacteria. In Escherichia coli, major nonspecific porins are matrix porin (OmpF) and osmoporin (OmpC), which show high sequence homology. In response to high osmolarity of the medium, OmpC is expressed at the expense of OmpF porin. Here, we study osmoporin of the pathogenic Klebsiella pneumoniae (OmpK36), which shares 87% sequence identity with E. coliOmpC in an attempt to establish why osmoporin is best suited to function at high osmotic pressure. RESULTS: The crystal structure of OmpK36 has been determined to a resolution of 3.2 A by molecular replacement with the model of OmpF. The structure of OmpK36 closely resembles that of the search model. The homotrimeric structure is composed of three hollow 16-stranded antiparallel beta barrels, each delimiting a separate pore. Most insertions and deletions with respect to OmpF are found in the loops that protrude towards the cell exterior. A characteristic ten-residue insertion in loop 4 contributes to the subunit interface. At the pore constriction, the replacement of an alanine by a tyrosine residue does not alter the pore profile of OmpK36 in comparison with OmpF because of the different course of the mainchain. Functionally, as characterized in lipid bilayers and liposomes, OmpK36 resembles OmpC with decreased conductance and increased cation selectivity in comparison with OmpF. CONCLUSIONS: The osmoporin structure suggests that not an altered pore size but an increase in charge density is the basis for the distinct physico-chemical properties of this porin that are relevant for its preferential expression at high osmotic strength