Remote Ischemic Conditioning Influences Mitochondrial Dynamics

Remote ischemic preconditioning (RIPC) has emerged as an attractive strategy to protect the heart against ischemia-reperfusion (I/R) injury. The mechanisms by which remote ischemic conditioning (RIC) is protective are to date unknown, yet a well-accepted theory holds that the mitochondria play a central role. Mitochondria are dynamic organelles that undergo fusion and fission. Interventions that decrease mitochondrial fission or increase mitochondrial fusion have been associated with reduced I/R injury. However, whether RIPC influences mitochondrial dynamics or not has yet to be ascertained.We sought to determine the role played by mitochondrial dynamics in RIPC-induced cardioprotection. Male adult rats exposed in vivo to myocardial I/R were assigned to one of two groups, either undergoing 40 min of myocardial ischemia followed by 120 min of reperfusion (MI group) or four 5-min cycles of limb ischemia interspersed by 5 min of limb reperfusion, immediately prior to myocardial ischemia and 120 min of reperfusion (MI+RIPC group). After reperfusion, infarct size was assessed and myocardial tissue was analyzed by Western blot and electron microscopy. RIPC induced smaller infarct size (-28%), increased mitochondrial fusion protein OPA1, and preserved mitochondrial morphology. These findings suggest that mitochondrial dynamics play a role in the mechanisms of RIPC-induced cardioprotection

The vascular phenotype in Pseudoxanthoma elasticum and related disorders: contribution of a genetic disease to the understanding of vascular calcification

Vascular calcification is a complex and dynamic process occurring in various physiological conditions such as aging and exercise or in acquired metabolic disorders like diabetes or chronic renal insufficiency. Arterial calcifications are also observed in several genetic diseases revealing the important role of unbalanced or defective anti- or pro-calcifying factors. Pseudoxanthoma elasticum (PXE) is an inherited disease (OMIM 264800) characterized by elastic fiber fragmentation and calcification in various soft conjunctive tissues including the skin, eyes, and arterial media. The PXE disease results from mutations in the ABCC6 gene, encoding an ATP-binding cassette transporter primarily expressed in the liver, kidneys suggesting that it is a prototypic metabolic soft-tissue calcifying disease of genetic origin. The clinical expression of the PXE arterial disease is characterized by an increased risk for coronary (myocardial infarction), cerebral (aneurysm and stroke), and lower limb peripheral artery disease. However, the structural and functional changes in the arterial wall induced by PXE are still unexplained. The use of a recombinant mouse model inactivated for the Abcc6 gene is an important tool for the understanding of the PXE pathophysiology although the vascular impact in this model remains limited to date. Overlapping of the PXE phenotype with other inherited calcifying diseases could bring important informations to our comprehension of the PXE disease

A Long Time Gone: Post-conflict Rural Property Restitution under Customary Law

Mass displacement of people due to violence poses a unique set of challenges for property restitution when people return to their homes after a long absence. This is particularly evident in rural areas where the dominant form of land holding is customary tenure. Violence-induced displacement, unlike voluntary migration, challenges both customary and public legaladministrative structures. The lack of written documentation of customary holdings and the importance of the support of community leaders means that incorporating returnees back into a community can be easier for those who choose to return, while reclaiming property without physical return is nearly impossible. This article seeks to make three contributions: 1) to note the diversity of return processes after long displacements in terms of timing and demographics; 2) to demonstrate that the nature of the claims people can make on customary tenure systems is at odds with international legal norms on property restitution after displacement; and 3) to introduce a set of observations and questions on how conflict can change customary law. The article is based on fieldwork conducted in Uganda, Liberia and Timor-Leste, all countries with extended displacement

Genetic admixture between captive-bred and wild individuals affects patterns of dispersal in a brown trout (Salmo trutta) population

Genetic admixture between captive-bred and wild individuals has been demonstrated to affect many individual traits, although little is known about its potential influence on dispersal, an important trait governing the eco-evolutionary dynamics of populations. Here, we quantified and described the spatial distribution of genetic admixture in a brown trout (Salmo trutta) population from a small watershed that was stocked until 1999, and then tested whether or not individual dispersal parameters were related to admixture between wild and captive-bred fish. We genotyped 715 fish at 17 microsatellite loci sampled from both the mainstream and all populated tributaries, as well as 48 fish from the hatchery used to stock the study area. First, we used Bayesian clustering to infer local genetic structure and to quantify genetic admixture. We inferred first generation migrants to identify dispersal events and test which features (genetic admixture, sex and body length) affected dispersal parameters (i.e. probability to disperse, distance of dispersal and direction of the dispersal event). We identified two genetic clusters in the river basin, corresponding to wild fish on the one hand and to fish derived from the captive strain on the other hand, allowing us to define an individual gradient of admixture. Individuals with a strong assignment to the captive strain occurred almost exclusively in some tributaries, and were more likely to disperse towards a tributary than towards a site of the mainstream. Furthermore, dispersal probability increased as the probability of assignment to the captive strain increased, and individuals with an intermediate level of admixture exhibited the lowest dispersal distances. These findings show that various dispersal parameters may be biased by admixture with captive-bred genotypes, and that management policies should take into account the differential spread of captive-bred individuals in wild populations

Déterrer, démêler et réarticuler les corps du génocide au Rwanda

This paper is concerned with the mass graves and exhumed bodies of victims of the Rwanda genocide and war of the 1990s. A government-led programme of exhumation of mass burials and individual graves has taken place over the last decade. The exhumation of mass graves has been undertaken, in the main, by Tutsi genocide survivors who work under the supervision of state officials. Post-unearthing, these bodies are unravelled, and the remnants of soft flesh, clothing, personal possessions and bones are separated from each other. Skeletal structures are fully disarticulated and the bones pooled into a vast collective, for placement within memorials. The outcome of these exhumations is that remains almost always lack individual identity at the point of reinterring. A productive analytical comparison is found in examining exhumations of Spanish Civil War graves, where the fates of individual dead are closely entangled with the lives of survivors. Here there is a clear contrast with exhumations in Rwanda, in the possible re-articulation of identities with specific human remains. But a similarity is also critical: in both cases the properties of human remains, as unsettling materials, garner specific 'affects', which drive forward national political projects that aim to consolidate particular collective memories of conflict, albeit that this kind of 'material agency' is mobilized to very different ends in each case

Kin-dependent dispersal influences relatedness and genetic structuring in a lek system

Kin selection and dispersal play a critical role in the evolution of cooperative breeding systems. Limited dispersal increases relatedness in spatially structured populations (population viscosity), with the result that neighbours tend to be genealogical relatives. Yet the increase in neighbours’ fitness-related performance through altruistic interaction may also result in habitat saturation and thus exacerbate local competition between kin. Our goal was to detect the footprint of kin selection and competition by examining the spatial structure of relatedness and by comparing non-effective and effective dispersal in a population of a lekking bird, Tetrao urogallus. For this purpose, we analysed capture–recapture and genetic data collected over a 6-year period on a spatially structured population of T. urogallus in France. Our findings revealed a strong spatial structure of relatedness in males. They also indicated that the population viscosity could allow male cooperation through two non-exclusive mechanisms. First, at their first lek attendance, males aggregate in a lek composed of relatives. Second, the distance corresponding to non-effective dispersal dramatically outweighed effective dispersal distance, which suggests that dispersers incur high post-settlement costs. These two mechanisms result in strong population genetic structuring in males. In females, our findings revealed a lower level of spatial structure of relatedness and genetic structure in respect to males. Additionally, non-effective dispersal and effective dispersal distances in females were highly similar, which suggests limited post- settlement costs. These results indicate that kin-dependent dispersal decisions and costs have a genetic footprint in wild populations and are factors that may be involved in the evolution of cooperative courtship

Adaptive Evolution of Staphylococcus aureus during Chronic Endobronchial Infection of a Cystic Fibrosis Patient

The molecular adaptation of Staphylococcus aureus to its host during chronic infection is not well understood. Comparative genome sequencing of 3 S. aureus isolates obtained sequentially over 26 months from the airways of a cystic fibrosis patient, revealed variation in phage content, and genetic polymorphisms in genes which influence antibiotic resistance, and global regulation of virulence. The majority of polymorphisms were isolate-specific suggesting the existence of an heterogeneous infecting population that evolved from a single infecting strain of S. aureus. The genetic variation identified correlated with differences in growth rate, hemolytic activity, and antibiotic sensitivity, implying a profound effect on the ecology of S. aureus. In particular, a high frequency of mutations in loci associated with the alternate transcription factor SigB, were observed. The identification of genes under diversifying selection during long-term infection may inform the design of novel therapeutics for the control of refractory chronic infections

“I’m only a dog!” : the Rwandan genocide, dehumanisation and the graphic novel

Graphic novels written in response to the 1994 Rwandan genocide do not confine their depictions of traumatic violence to humans, but extend their coverage to show how the genocide impacted on animals and the environment. Through analysis of the presentation of people and their relationships with other species across a range of graphic narratives, this article shows how animal imagery was used to justify inhumane actions during the genocide, and argues that representations of animals remain central to the recuperation processes in a post-genocide context too. Whilst novels and films that respond to the genocide have been the focus of scholarly work (Dauge-Roth, 2010), the graphic novel has yet to receive substantial critical attention. This article therefore unlocks the archive of French-, Dutch- and English-language graphic narratives written in response to the genocide by providing the first in-depth, comparative analysis of their animal representations. It draws on recent methodological approaches derived from philosophy (Derrida, [2008] trans. 2009), postcolonial ecocriticism (Huggan and Tiffin, 2010) and postcolonial trauma theory (Craps, 2012) in order show how human-centred strategies for recovery, and associated symbolic orders that forcefully position the animal outside of human law, continue to engender unequal and potentially violent relationships between humans, and humans and other species. In this way, graphic narratives that gesture towards more equitable relationships between humans, animals and the environment can be seen to support the processes of recovery and reconciliation in post-genocide Rwanda