Interspecific variation in the limb long bones among modern rhinoceroses—extent and drivers

International audienceAmong amniotes, numerous lineages are subject to an evolutionary trend toward body mass and size increases. Large terrestrial species may face important constraints linked to weight bearing, and the limb segments are particularly affected by such constraints due to their role in body support and locomotion. Such groups showing important limb modifications related to high body mass have been called "graviportal." Often considered graviportal, rhinoceroses are among the heaviest terrestrial mammals and are thus of particular interest to understand the limb modifications related to body mass and size increase. Here, we present a morphofunctional study of the shape variation of the limb long bones among the five living rhinos to understand how the shape may vary between these species in relation with body size, body mass and phylogeny. We used three dimensional geometric morphometrics and comparative analyses to quantify the shape variation. Our results indicate that the five species display important morphological differences depending on the considered bones. The humerus and the femur exhibit noticeable interspecific differences between African and Asiatic rhinos, associated with a significant effect of body mass. The radius and ulna are more strongly correlated with body mass. While the tibia exhibits shape variation both linked with phylogeny and body mass, the fibula displays the greatest intraspecific variation. We highlight three distinct morphotypes of bone shape, which appear in accordance with the phylogeny. The influence of body mass also appears unequally expressed on the different bones. Body mass increase among the five extant species is marked by an increase of the general robustness, more pronounced attachments for muscles and a development of medial parts of the bones. Our study underlines that the morphological features linked to body mass increase are not similar between rhinos and other heavy mammals such as elephants and hippos, suggesting that the weight bearing constraint can lead to different morphological responses

3D models related to the publication: Comparative anatomy and phylogenetic contribution of intracranial osseous canals and cavities in armadillos and glyptodonts (Xenarthra, Cingulata)

INTRODUCTION: The phylogeny of the Cingulata has been debated in morphological analyses for a long time (Engelmann, 1985; Gaudin &Wible, 2006; Billet et al., 2011; Delsuc et al., 2016; Mitchell et al., 2016; Herrera et al., 2017) and this incongruence was enriched by the contribution of recent molecular analyses (Delsuc et al., 2016; Mitchell et al., 2016). This is particularly the case for the emblematic group of glyptodonts whose mitochondrial genome was recently assembled (Delsuc et al., 2016; Mitchell et al., 2016). Although the cranial anatomy is relatively well known in xenarthrans, their internal cranial anatomy remains poorly studied. Yet, several studies have shown that their exploration provides systematic interest on their past and present diversity (Zurita et al., 2011; Fernicola et al., 2012; Billet et al., 2015; Tambusso & Fari˜na, 2015a; Tambusso & Fari˜na, 2015b; Billet et al., 2017; Boscaini et al., 2018; Boscaini et al., 2020; Tambusso et al., 2021). In a recent study (Le Verger et al., 2021), we describe and compare 8 cranial canals (involved in the vascularization and innervation of the cranium) and alveolar cavities (Figure 1) of 30 specimens belonging to the Cingulata. In this sampling, all extant subfamilies are represented and several large fossil groups including giant forms such as pampatheres and glyptodonts are represented. For the latter, the oldest complete crania have been studied. A sloth and an anteater were also added to the sample as outgroup. Of the total sample, 3D models of 13 specimens are made available (Table 1). The rest of the specimens are available only upon request from LGR. In this study (Le Verger et al., 2021), we present the comparativ investigation of these intracranial osseous canals and alveolar cavities using X-ray microtomography. Their 3D virtual reconstruction enabled us to compare the locations, trajectories, and shape of each homologous structure and discuss their potential interest for cingulate systematics

Strengthening women´s and youths’ access to innovation support services (ISS): The 24 h’ cassava retting case in Cameroon

Strengthening the participation of women and youths in agri-food innovation processes is key to support the development of solutions that meet their needs and that enhance their capacity to drive change in rural areas. We disentangle the 24 hours cassava retting case in Cameroon into three service situations across the ideation, development and dissemination phases. We then assess the intention of inclusion of key innovation support service providers (ISPs) and their approaches, the roles played by women and youths, and the capacity of women and youths to fully benefit from innovation support services (ISS) depending on factors at the personal/agency, relational and structural/environmental levels – an adaptation of the gender-transformative approach (GTA) framework. We find that ISPs wish to target women and youths, but this objective is only assessed in quantitative terms. A deeper understanding of what favors or constrains the capacity to use services and resources of innovative actors at the personal or collective levels would help improve the inclusiveness and quality of ISS, as well as raise awareness of deeper structural changes that are needed at the policy, informal norms and environmental levels. Some women benefit from skills and knowledge, personal traits, as well as from extensive support networks that allow them to overcome the constraining patriarchal norms to innovate. Their capacity to support the active participation of people constrained by e.g. remoteness, health and disability issues or unfavorable gender norms, should be strengthened. This can be supported by extended research and knowledge sharing about innovative solutions found to some specific problems faced by marginalized people across Sub-Saharan Africa. ISPs should also develop, coordinate, and qualitatively assess their activities to help underserved people participate in innovation processes in rural areas

Pervasive cranial allometry at different anatomical scales and variational levels in extant armadillos

Allometry, i.e., morphological variation correlated with size, is a major pattern in organismal evolution. Since size varies both within and among species, allometry occurs at different variational levels. However, the variability of allometric patterns across levels is poorly known since its evaluation requires extensive comparative studies. Here, we implemented a 3D geometric morphometric approach to investigate cranial allometry at three main variational levels—static, ontogenetic, and evolutionary—and two anatomical scales—entire cranium and cranial subunits—based on a dense intra- and interspecific sampling of extant armadillo diversity. While allometric trajectories differ among distantly related species, they hardly do so among sister families. This suggests that phylogenetic distance plays an important role in explaining allometric divergences. Beyond trajectories, our analyses revealed pervasive allometric shape changes shared across variational levels and anatomical scales. At the entire cranial scale, craniofacial allometry (relative snout elongation and braincase reduction) is accompanied notably by variations of nuchal crests and postorbital constriction. Among cranial subunits, the distribution of allometry was highly heterogeneous, with the frontal and petrosal bones showing the most pervasive shape changes, some of which were undetected at a more global scale. Evidence of widespread and superimposed allometric variations raises questions on their determinants and anatomical correlates and demonstrates the critical role of allometry in morphological evolution

Wake attenuation in large Reynolds number dispersed two-phase flows

The dynamics of high Reynolds number-dispersed two-phase flow strongly depends on the wakes generated behind the moving bodies that constitute the dispersed phase. The length of these wakes is considerably reduced compared with those developing behind isolated bodies. In this paper, this wake attenuation is studied from several complementary experimental investigations with the aim of determining how it depends on the body Reynolds number and the volume fraction a. It is first shown that the wakes inside a homogeneous swarm of rising bubbles decay exponentially with a characteristic length that scales as the ratio of the bubble diameter d to the drag coefficient Cd, and surprisingly does not depend on a for 10K2%a%10K1. The attenuation of the wakes in a fixed array of spheres randomly distributed in space (aZ2!10K2) is observed to be stronger than that of the wake of an isolated sphere in a turbulent incident flow, but similar to that of bubbles within a homogeneous swarm. It thus appears that the wakes in dispersed two-phase flows are controlled by multi-body interactions, which cause a much faster decay than turbulent fluctuations having the same energy and integral length scale. Decomposition of velocity fluctuations into a contribution related to temporal variations and that associated to the random character of the body positions is proposed as a perspective for studying the mechanisms responsible for multi-body interactions

Differential influences of allometry, phylogeny and environment on the rostral shape diversity of extinct South American notoungulates

Understanding the mechanisms responsible for phenotypic diversification, and the associated underlying constraints and ecological factors represents a central issue in evolutionary biology. Mammals present a wide variety of sizes and shapes, and are characterized by a high number of morphological convergences that are hypothesized to reflect similar environmental pressures. Extinct South American notoungulates evolved in isolation from northern mammalian faunas in highly disparate environments. They present a wide array of skeletal phenotypes and convergences, such as ever-growing dentition. Here, we focused on the origins of the rostral diversity of notoungulates by quantifying the shape of 26 genera using three-dimensional geometric morphometric analysis. We tested the influence of allometry and phylogeny on rostral shape and evaluated rates of evolutionary change in the different clades. We found strong allometric and phylogenetic signals concerning the rostral shape of notoungulates. Despite convergent forms, we observed a diffuse diversification of rostral shape, with no significant evidence of influence by large-scaled environmental variation. This contrasts with the increase in dental crown height that occurred in four late-diverging families in response to similar environmental pressures. These results illustrate the importance of considering both biological components and evolutionary rates to better understand some aspects of phenotypic diversity.Fil: Gomes Rodrigues, Helder. Muséum National d'Histoire Naturelle; Francia. Centre National de la Recherche Scientifique; FranciaFil: Cornette, Raphaël. Centre National de la Recherche Scientifique; Francia. Muséum National d'Histoire Naturelle; FranciaFil: Clavel, Julien. Ecole Normale Supérieure; Francia. Centre National de la Recherche Scientifique; FranciaFil: Cassini, Guillermo Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina. Universidad Nacional de Luján. Departamento de Ciencias Básicas; ArgentinaFil: Bhullar, Bhart-Anjan S. . University of Yale; Estados UnidosFil: Fernández-Monescillo, Marcos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Moreno, Karen. Universidad Austral de Chile. Instituto de Ciencias de la Tierra; ChileFil: Herrel, Anthony. Centre National de la Recherche Scientifique; Francia. Muséum National d'Histoire Naturelle; FranciaFil: Billet, Guillaume. Muséum National d'Histoire Naturelle; Francia. Centre National de la Recherche Scientifique; Franci

Ancient Mitogenomes Shed Light on the Evolutionary History and Biogeography of Sloths

International audienc

The phylogenetic affinities of the extinct glyptodonts

Among the fossils of hitherto unknown mammals that Darwin collected in South America between 1832 and 1833 during the Beagle expedition [1] were examples of the large, heavily armored herbivores later known as glyptodonts. Ever since, glyptodonts have fascinated evolutionary biologists because of their remarkable skeletal adaptations and seemingly isolated phylogenetic position even within their natural group, the cingulate xenarthrans (armadillos and their allies [2]). In possessing a carapace comprised of fused osteoderms, the glyptodonts were clearly related to other cingulates, but their precise phylogenetic position as suggested by morphology remains unresolved [3,4]. To provide a molecular perspective on this issue, we designed sequence-capture baits using in silico reconstructed ancestral sequences and successfully assembled the complete mitochondrial genome of Doedicurus sp., one of the largest glyptodonts. Our phylogenetic reconstructions establish that glyptodonts are in fact deeply nested within the armadillo crown-group, representing a distinct subfamily (Glyptodontinae) within family Chlamyphoridae [5]. Molecular dating suggests that glyptodonts diverged no earlier than around 35 million years ago, in good agreement with their fossil record. Our results highlight the derived nature of the glyptodont morphotype, one aspect of which is a spectacular increase in body size until their extinction at the end of the last ice age.Facultad de Ciencias Naturales y Muse

Hydrodynamic study of a monolith-type reactor for intensification of gas-liquid applications

Two-phase monolith-type reactors allow intensified heat and mass transfer rates, but often suffer from fluid maldistribution and undesired flow regimes in channels. A cold-flow monolith reactor (0.1 m diameter, 84 channels) is used here to assess liquid distribution and flow regimes at various air and water velocities: resistive probes give an insight of the flow patterns within 5 representative channels located at different radial positions, showing that regime transition to Taylor flow occurs in these channels simultaneously at lower gas and liquid superficial velocities than predicted by single capillary studies (namely uL and uG < 0.1 m s−1). nA full mapping of the partial liquid flow rates in the monolith channels is derived by a gravimetric method via specifically designed collectors. In the identified Taylor flow domain, liquid distribution exhibits a W-shaped profile with marked peaks at low liquid velocity (uL = 0.04 m s−1). Increasing the liquid flow rate significantly (uL = 0.1 m s−1) smooths liquid distribution, reducing the maldistribution factor by half. Gas velocity also helps phase uniformity but to a smaller extent. It is estimated that even higher fluid velocities (at least tripled) would be required to feed all channels equally. Adding stack of distribution plates of variable cell density at the top of the monolith does not enhance the quality of the liquid distribution, except at low liquid velocity

Field-Based Metabolomics of Vitis vinifera L. Stems Provides New Insights for Genotype Discrimination and Polyphenol Metabolism Structuring

Grape accumulates numerous polyphenols with abundant health benefit and organoleptic properties that in planta act as key components of the plant defense system against diseases. Considerable advances have been made in the chemical characterization of wine metabolites particularly volatile and polyphenolic compounds. However, the metabotyping (metabolite-phenotype characterization) of grape varieties, from polyphenolic-rich vineyard by-product is unprecedented. As this composition might result from the complex interaction between genotype, environment and viticultural practices, a field experiment was setting up with uniform pedo-climatic factors and viticultural practices of growing vines to favor the genetic determinism of polyphenol expression. As a result, UPLC-MS-based targeted metabolomic analyses of grape stems from 8 Vitis vinifera L. cultivars allowed the determination of 42 polyphenols related to phenolic acids, flavonoids, procyanidins, and stilbenoids as resveratrol oligomers (degree of oligomerization 1–4). Using a partial least-square discriminant analysis approach, grape stem chemical profiles were discriminated according to their genotypic origin showing that polyphenol profile express a varietal signature. Furthermore, hierarchical clustering highlights various degree of polyphenol similarity between grape varieties that were in agreement with the genetic distance using clustering analyses of 22 microsatellite DNA markers. Metabolite correlation network suggested that several polyphenol subclasses were differently controlled. The present polyphenol metabotyping approach coupled to multivariate statistical analyses might assist grape selection programs to improve metabolites with both health-benefit potential and plant defense traits