The Central Complex as a Potential Substrate for Vector Based Navigation

International audienceInsects use path integration (PI) to maintain a home vector, but can also store and recall vector-memories that take them from home to a food location, and even allow them to take novel shortcuts between food locations. The neural circuit of the Central Complex (a brain area that receives compass and optic flow information) forms a plausible substrate for these behaviors. A recent model, grounded in neurophysiological and neuroanatomical data, can account for PI during outbound exploratory routes and the control of steering to return home. Here, we show that minor, hypothetical but neurally plausible, extensions of this model can additionally explain how insects could store and recall PI vectors to follow food-ward paths, take shortcuts, search at the feeder and re-calibrate their vector-memories with experience. In addition, a simple assumption about how one of multiple vector-memories might be chosen at any point in time can produce the development and maintenance of efficient routes between multiple locations, as observed in bees. The central complex circuitry is therefore well-suited to allow for a rich vector-based navigational repertoire

Halofuginone regulates keloid fibroblast fibrotic response to TGF-β induction

Keloids are characterized by increased deposition of fibrous tissue in the skin and subcutaneous tissue following an abnormal wound healing process. Although keloid etiology is yet to be fully understood, fibroblasts are known to be key players in its development. Here we analyze the antifibrotic mechanisms of Halofuginone (HF), a drug reportedly able to inhibit the TGF-β1-Smad3 pathway and to attenuate collagen synthesis, in an in-vitro keloid model using patient-derived Keloid Fibroblasts (KFs) isolated from fibrotic tissue collected during the "Scar Wars" clinical study (NCT NCT03312166). TGF-β1 was used as a pro-fibrotic agent to stimulate fibroblasts response under HF treatment. The fibrotic related properties of KFs, including survival, migration, proliferation, myofibroblasts conversion, ECM synthesis and remodeling, were investigated in 2D and 3D cultures. HF at 50 nM concentration impaired KFs proliferation, and decreased TGF-β1-induced expression of α-SMA and type I procollagen production. HF treatment also reduced KFs migration, prevented matrix contraction and increased the metallo-proteases/inhibitors (MMP/TIMP) ratio. Overall, HF elicits an anti-fibrotic contrasting the TGF-β1 stimulation of KFs, thus supporting its therapeutic use for keloid prevention and management

Mio-Pliocene Faunal Exchanges and African Biogeography: The Record of Fossil Bovids

The development of the Ethiopian biogeographic realm since the late Miocene is here explored with the presentation and review of fossil evidence from eastern Africa. Prostrepsiceros cf. vinayaki and an unknown species of possible caprin affinity are described from the hominid-bearing Asa Koma and Kuseralee Members (∼5.7 and ∼5.2 Ma) of the Middle Awash, Ethiopia. The Middle Awash Prostrepsiceros cf. vinayaki constitutes the first record of this taxon from Africa, previously known from the Siwaliks and Arabia. The possible caprin joins a number of isolated records of caprin or caprin-like taxa recorded, but poorly understood, from the late Neogene of Africa. The identification of these two taxa from the Middle Awash prompts an overdue review of fossil bovids from the sub-Saharan African record that demonstrate Eurasian affinities, including the reduncin Kobus porrecticornis, and species of Tragoportax. The fossil bovid record provides evidence for greater biological continuity between Africa and Eurasia in the late Miocene and earliest Pliocene than is found later in time. In contrast, the early Pliocene (after 5 Ma) saw the loss of any significant proportions of Eurasian-related taxa, and the continental dominance of African-endemic taxa and lineages, a pattern that continues today

Navigating infection risk during oviposition and cannibalistic foraging in a holometabolous insect

Deciding where to eat and raise offspring carries important fitness consequences for all animals, especially if foraging, feeding and reproduction increase pathogen exposure. In insects with complete metamorphosis, foraging mainly occurs during the larval stage, while oviposition decisions are made by adult females. Selection for infection avoidance behaviours may therefore be developmentally uncoupled. Using a combination of experimental infections and behavioral choice assays, we tested if Drosophila melanogaster fruit flies avoid infectious environments at distinct developmental stages. When given conspecific fly carcasses as a food source, larvae did not discriminate between carcasses that were clean or infected with the pathogenic Drosophila C Virus (DCV), even though cannibalism was a viable route of DCV transmission. When laying eggs, DCV-infected females did not discriminate between infectious and non-infectious carcasses. Healthy mothers however, laid more eggs near a clean rather than an infectious carcass. Avoidance during oviposition changed over time: after an initial oviposition period, healthy mothers stopped avoiding infectious carcasses. We attribute this to a trade-off between infection risk and reproduction. Laying eggs near potentially infectious carcasses was always preferred to sites containing only fly food. Our findings suggest infection avoidance contributes to how mothers provision their offspring and underline the need to consider infection avoidance behaviors at multiple life-stages

Does Kin Recognition and Sib-Mating Avoidance Limit the Risk of Genetic Incompatibility in a Parasitic Wasp?

Background: When some combinations of maternal and paternal alleles have a detrimental effect on offspring fitness, females should be able to choose mates on the basis of their genetic compatibility. In numerous Hymenoptera, the sex of an individual depends of the allelic combination at a specific locus (single-locus Complementary Sex Determination), and in most of these species individuals that are homozygous at this sexual locus develop into diploid males with zero fitness. Methods and Findings: In this paper, we tested the hypothesis of genetic incompatibility avoidance by investigating sibmating avoidance in the solitary wasp parasitoid, Venturia canescens. In the context of mate choice we show, for the first time in a non-social hymenopteran species, that females can avoid mating with their brothers through kin recognition. In ‘‘no-choice’ ’ tests, the probability a female will mate with an unrelated male is twice as high as the chance of her mating with her brothers. In contrast, in choice tests in small test arenas, no kin discrimination effect was observed. Further experiments with male extracts demonstrate that chemical cues emanating from related males influence the acceptance rate of unrelated males. Conclusions: Our results are compatible with the genetic incompatibility hypothesis. They suggest that the female wasps recognize sibs on the basis of a chemical signature carried or emitted by males possibly using a ‘‘self-referent phenotyp

Les modèles de maturité comme outil d’alignement des acteurs dans les écosystèmes d’innovation : Le cas des Concept Maturity Levels dans les Medtech

International audienceLes organisations du secteur de la santé font face à de nombreux défis, cliniques, technologiques et réglementaires, ainsi qu’aux exigences du marché et des besoins des patients. Ces défis rendent la gestion des projets d’innovation complexe et difficile à appréhender seul, poussant les acteurs à combiner leurs ressources et compétences dans des écosystèmes d’innovation. Ces écosystèmes regroupent généralement des acteurs divers (e.g., professionnels de la santé, patients, associations, universités, start-ups, …) avec des objectifs et intérêts pouvant diverger. Il devient alors important d’aligner ces acteurs pour réaliser la proposition de valeur de leur écosystème d’innovation. La littérature montre comment certains éléments clés, tels qu’une vision et une compréhension commune, l’adaptation mutuelle et la standardisation entre les membres, contribuent à cet alignement. En revanche, peu de recherches portent sur les moyens concrets de produire ces éléments clés et sur les outils dont disposent les acteurs d’un écosystème pour y parvenir. Dans cet article, nous avançons l’idée que les métriques de maturité, particulièrement les Concept Maturity Levels (CML), peuvent être utilisées dans les écosystèmes comme un outil pour favoriser l'alignement des acteurs, de leurs activités, positions et liens entre eux. Nous nous basons sur plusieurs cas d’usage des CML par des chefs de projet, chargés d’accompagnement et chargés de financement du secteur des Medtech français pour comprendre leur connaissance, expérience, ou intérêt pour les CML. Des résultats intermédiaires indiquent que ces différents acteurs utilisent les CML pour cartographier, ordonner et normer les activités, compétences, et ressources de leurs écosystèmes respectifs

Experimental analysis of a keloid on upper arm by using biomechanical devices

International audienceKeloid scars are benign skin tumors-like, that affect only humanity, and more specifically asian and african populations. Keloids consist in the excessive accumulation of dermal collagen that extends beyond the boundaries of the original wound [1]. They are located on specific sites, tend to enlarge over time, and pose cosmetic and psychological problems for patients. The physiopathology of keloids is unclear and there is still no therapeutic consensus. Nevertheless it appears that keloids result from a combination of genetic, cellular and mechanical factors [2].The present study deals with a multi-devices experimental analysis in order to characterize the mechanical behavior of the keloid, the surrounding healthy skin and the contralateral healthy skin on the left upper arm of one young female clinical case

Characterisation of tissues properties in « optical biopsy » field: a new non-invasive way of exploration

International audience<font face="null"&gt<span style="font-size: 13px;"&gtCharacterisation of tissues properties in « optical biopsy » field: a new non-invasive way of exploration</span&gt</font&g

Functional analysis to drive research and identify regulation requirements: an example with a lithium monitoring device

International audienceMedical device development is often understood as a linear process with design stages occurring sequentially. First stages are usually performed in order to specify the future device definition through interviews/meetings of the end-users, researchers and manufacturers. Because the medical device is original, these first stages mainly involve end-users and researcher. However, regulation constraints and economic reality sometimes makes manufacturers hesitant to base the industrial development on this initial basis. Functional analysis, well known by manufacturers, is a method used to accurately define the final functions of a medical device. In this conference, we estimate that the functional analysis can be put to profit in a more efficient way if researchers and end-users get familiar with it prior to the interview/meeting stages. Although the results of such knowledge democratisation is not demonstrated here, we present the function analysis conducted on a lithium monitoring device according to this multidisciplinary approach. We also show that function analysis can be used not only to drive research actions but also to identify regulation requirements