Reversion of developmental mode in insects: evolution from long germband to short germband in the polyembrionic wasp Macrocentrus cingulum Brischke

The deposited article is a post-print version and has peer review. This publication hasn't any creative commons license associated. There is no public supplementary material available for this publication.Germband size in insects has played a central role in our understanding of insect patterning mechanisms and their evolution. The polarity of evolutionary change in insect patterning has been viewed so far as the unidirectional shift from the ancestral short germband patterning of basal hemimetabolous insects to the long germband patterning observed in most modern Holometabola. However, some orders of holometabolic insects display both short and long germband development, though the absence of a clear phylogenetic context does not permit definite conclusions on the polarity of change. Derived hymenoptera, that is, bees and wasps, represent a classical textbook example of long germband development. Yet, in some wasps putative short germband development has been described correlating with lifestyle changes, namely with evolution of endoparasitism and polyembryony. To address the potential reversion from long to short germband, we focused on the family Braconidae, which displays ancestral long germband development, and examined the derived polyembryonic braconid Macrocentrus cingulum. Using SEM analysis of M. cingulum embryogenesis coupled with analyses of embryonic patterning markers, we show that this wasp evolved short germband embryogenesis secondarily, in a way that is reminiscent of embryogenesis in the beetle Tribolium castaneum. This work shows that the evolution of germband size in insects is a reversible process that may correlate with other life-history traits and suggests broader implications on the mechanisms and evolvability of insect development.Parke-Davis fellowship; Canadian Foundation for Innovation new opportunity grant; Instituto Gulbenkian de Ciência/Fundação Calouste Gulbenkian grant: (NSERC operating grant).info:eu-repo/semantics/publishedVersio

Superparamagnetic relaxation in Cu_{x}Fe_{3-x}O_{4} (x=0.5 and x=1) nanoparticles

The scope of this article is to report very detailed results of the measurements of magnetic relaxation phenomena in the new Cu$_{0.5}$Fe$_{2.5}$O$_{4}$ nanoparticles and known CuFe$_{2}$O$_{4}$ nanoparticles. The size of synthesized particles is (6.5$\pm$1.5)nm. Both samples show the superparamagnetic behaviour, with the well-defined phenomena of blocking of magnetic moment. This includes the splitting of zero-field-cooled and field-cooled magnetic moment curves, dynamical hysteresis, slow quasi-logarithmic relaxation of magnetic moment below blocking temperature. The scaling of the magnetic moment relaxation data at different temperatures confirms the applicability of the simple thermal relaxation model. The two copper-ferrites with similar structures show significantly different magnetic anisotropy density and other magnetic properties. Investigated systems exhibit the consistency of all obtained results.Comment: 18 pages, 8 figure

Sedimentation during MIS 3 at the eastern margins of the Glacial Lake Humber basin, England

The stratigraphic sequence at North Cave, on the eastern margins of the Lake Humber basin, records the deposition of a fluvioperiglacial fan (LFs 1–4), with early sedimentation (LF1) dating to Marine Isotope Stage (MIS) 3 (optically stimulated luminescence date range 41.8–38.6 ka and 14C dates 41.6–49 ka BP). Three phases of permafrost and ice wedge development during MIS 3 are evident and indicate possible fan abandonment and hence periods of reduced nival runoff. Involution structures dated to 11.1 ka with large boulders and fine‐grained sorted circles in LF4b are interpreted as periglacially cryoturbated littoral deposits with boulders derived from anchor ice, initially deposited at the margins of Lake Humber up to an altitude of 8 m OD during MIS 2. The style and age of fluvioperiglacial fan deposition at North Cave is compatible with several mid‐Devensian sites around Britain characterized by significant nival melt and run‐off from steeply incised valleys in permafrozen cuesta landscapes. This phase of fluvioperiglacial fan aggradation to near or below 0 m OD is recorded around the glacial lakes Humber and Fenland basins and indicates that no glacial lakes existed at that time

Oldest skeleton of a fossil flying squirrel casts new light on the phylogeny of the group

Flying squirrels are the only group of gliding mammals with a remarkable diversity and wide geographical range. However, their evolutionary story is not well known. Thus far, identification of extinct flying squirrels has been exclusively based on dental features, which, contrary to certain postcranial characters, are not unique to them. Therefore, fossils attributed to this clade may indeed belong to other squirrel groups. Here we report the oldest fossil skeleton of a flying squirrel (11.6 Ma) that displays the gliding-related diagnostic features shared by extant forms and allows for a recalibration of the divergence time between tree and flying squirrels. Our phylogenetic analyses combining morphological and molecular data generally support older dates than previous molecular estimates (\~23 Ma), being congruent with the inclusion of some of the earliest fossils (\~36 Ma) into this clade. They also show that flying squirrels experienced little morphological change for almost 12 million years

Impact de la physiologie orale de la personne âgée sur sa prise alimentaire; quelles solutions pour maintenir le statut nutritionnel ?

Context. In human, oral food intake is the ultimate stage of food supply chain and the beginning of food disintegration and the digestion process. During aging, the oral health changes and sometimes eating food can be a real challenge as food can be hard to masticate, humidify or swallow.Objective. The aim of the present study is to determine which oral factors (salivary, dental, tongue strength) have an impact on physiological – ability to form a food bolus – and psychological – pleasure to eat – dimensions of food oral processing in order to select culinary techniques and help elderlies maintaining an appropriate protein intake in spite of the occurrence of poor oral health.Material and method. Resting and stimulated salivary flow, oral status, the ability to form a food bolus, the pleasure induced by food consumption and the nutritional status were measured on 108 elderly people (65-92 years old, living at home, with no acute pathology at the time of the study). In parallel, culinary technics that aimed at improving meat texture were developed and evaluated throughout physical measurements and oral comfort assessment by the elderly volunteers.Results and conclusion. Multivariate analysis highlighted the fact that oral factors (salivary, dental, muscular) play different roles in food oral processing and eating behavior in elderly people. Moreover, the assessment of oral comfort on the culinary technics showed that some technics improve significantly meat tenderness and juiciness. Those results will help the development of food offer tailored to elderly people with or without oral health impairments.Contexte. Chez l’homme, la mise en bouche d’un aliment est l’étape ultime de la chaîne alimentaire et le début du processus de dégradation et de digestion. Avec l’âge la santé orale évolue et peut parfois rendre l’acte alimentaire difficile.Objectif. L’objectif de cette étude est de déterminer les facteurs (salivaire, dentaire, musculaire) impactant sur les dimensions physiologiques (faculté à former un bol alimentaire, libération et perception de la flaveur) de l’acte alimentaire et/ou la prise alimentaire et la corpulence des séniors. Ceci permettra de d’identifier des techniques culinaires permettant d’adapter la texture des aliments aux problèmes bucco-dentaires.Matériel et méthode. 108 séniors (>65 ans) vivant à domicile et ne présentant pas de pathologie chronique ont été recrutés et caractérisés sur la base des dimensions suivantes : santé orale (examen clinique), auto-évaluation de la santé orale, perceptions sensorielles, faculté à former un bol alimentaire, comportement alimentaire, état de santé général. En parallèle, des techniques culinaires permettant d’améliorer la texture de la viande ont été testées. Leur efficacité a été évaluée via des mesures rhéologiques et la perception du confort en bouche par les séniors eux-mêmes.Résultats et conclusion. L’analyse multidimensionnelle des données montre que les facteurs de santé orale (dentition, salivation, force musculaire) jouent des rôles différents dans les processus de mastication et de prise alimentaire chez les personnes âgées. De plus, l’étude du confort en bouche a permis de sélectionner des techniques culinaires optimisant la tendreté et la jutosité de la viande. Ces résultats permettront de développer une offre alimentaire adaptée aux troubles oraux survenant avec l’âge

Mast cells are key mediators of cathelicidin-initiated skin inflammation in rosacea.

Rosacea is a chronic inflammatory skin disease whose pathophysiological mechanism is still unclear. However, it is known that mast cell (MC) numbers are increased in the dermis of rosacea patients. MC proteases not only recruit other immune cells, which amplify the inflammatory response, but also cause vasodilation and angiogenesis. MCs are also one of the primary sources of cathelicidin LL-37 (Cath LL-37), an antimicrobial peptide that has been shown to be an enabler of rosacea pathogenesis. Here, we demonstrate that MCs are key mediators of cathelicidin-initiated skin inflammation. After Cath LL-37 injection into the dermis, MC-deficient B6.Cg-Kit(W-sh)/HNihrJaeBsmJ (KitW-sh) mice did not develop rosacea-like features. Conversely, chymase (P<0.001), tryptase, and Mmp9 (P<0.01) mRNA levels were significantly higher in C57BL/6 wild-type (WT) mice. Treating WT mice with an MC stabilizer significantly decreased the expressions of Mmp9 and Cxcl2 (P<0.01). Our data were confirmed on erythematotelangiectatic rosacea subjects who showed a decrease in matrix metalloproteinase activity (P<0.05), after 8 weeks of topical cromolyn treatment. We conclude that MCs have a central role in the development of inflammation subsequent to Cath LL-37 activation and that downregulation of activated MCs may be a therapy for rosacea treatment