The postcranial anatomy of Gorgonops torvus (Synapsida, Gorgonopsia) from the late Permian of South Africa

The article processing charge was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – 491192747 and the Open Access Publication Fund of Humboldt-Universität zu Berlin.Gorgonopsians are among the most recognizable groups of synapsids from the Permian period and have an extensive but mostly cranial fossil record. By contrast, relatively little is known about their postcranial anatomy. Here, we describe a nearly complete, semi-articulated skeleton of a gorgonopsian (identified as Gorgonops torvus) from the late Permian Endothiodon Assemblage Zone of the South African Karoo Basin and discuss its paleobiological implications. Known gorgonopsian postcrania indicate morphological conservatism in the group, but the skeletal anatomy of Gorgonops does differ from that of other gorgonopsians in some respects, such as in the triangular radiale and short terminal phalanges in the manus, and a weakly developed distinction between pubis and ischium in ventral aspect of the pelvic girdle. Similarities between the specimen described herein and a historically problematic specimen originally referred to “Scymnognathus cf. whaitsi” confirm referral of the latter specimen to Gorgonops. Since descriptions of gorgonopsian postcrania are rare, new interpretations of the lifestyle and ecology of Gorgonopsia can be drawn from our contribution. We conclude that gorgonopsians were likely ambush predators, able to chase their prey over short distances and pin them down with strong forelimbs before using their canines for the kill. This is evidenced by their different fore- and hindlimb morphology; the former stouter and more robust in comparison to the longer, more gracile, back legs. Furthermore, the completeness of the study specimen facilitates calculation of an estimated body mass of approximately 98 kg, similar to that of a modern lioness.Peer Reviewe

The earliest segmental sternum in a Permian synapsid and its implications for the evolution of mammalian locomotion and ventilation

The article processing charge was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – 491192747 and the Open Access Publication Fund of Humboldt-Universität zu Berlin.The sternum is a stabilizing element in the axial skeleton of most tetrapods, closely linked with the function of the pectoral girdle of the appendicular skeleton. Modern mammals have a distinctive sternum characterized by multiple ossified segments, the origins of which are poorly understood. Although the evolution of the pectoral girdle has been extensively studied in early members of the mammalian total group (Synapsida), only limited data exist for the sternum. Ancestrally, synapsids exhibit a single sternal element and previously the earliest report of a segmental sternum in non-mammalian synapsids was in the Middle Triassic cynodont Diademodon tetragonus. Here, we describe the well-preserved sternum of a gorgonopsian, a group of sabre-toothed synapsids from the Permian. It represents an ossified, multipartite element resembling the mammalian condition. This discovery pulls back the origin of the distinctive “mammalian” sternum to the base of Theriodontia, significantly extending the temporal range of this morphology. Through a review of sternal morphology across Synapsida, we reconstruct the evolutionary history of this structure. Furthermore, we explore its role in the evolution of mammalian posture, gait, and ventilation through progressive regionalization of the postcranium as well as the posteriorization of musculature associated with mammalian breathing.Peer Reviewe

Association of Circulating Renin and Aldosterone With Osteocalcin and Bone Mineral Density in African Ancestry Families

Hypertension is associated with accelerated bone loss, and the renin-angiotensin-aldosterone system is a key regulator of blood pressure. Although components of this system are expressed in human bone cells, studies in humans are sparse. Thus, we studied the association of circulating renin and aldosterone with osteocalcin and bone mineral density. We recruited 373 African ancestry family members without regard to health status from 6 probands (mean family size: 62 and relative pairs: 1687). Participants underwent a clinical examination, dual-energy x-ray absorptiometry, and quantitative computed tomographic scans. Renin activity, aldosterone concentration, and osteocalcin were measured in fasting blood samples. Aldosterone/renin ratio was calculated as aldosterone concentration/renin activity. All models were analyzed using pedigree-based variance components methods. Full models included adjustment for age, sex, body composition, comorbidities, lifestyle factors, blood pressure, and antihypertensive medication. Higher renin activity was significantly associated with lower total osteocalcin and with higher trabecular bone mineral density (both P<0.01). There were also significant genetic correlations between renin activity and whole-body bone mineral density. There were no associations with aldosterone concentration in any model and results for aldosterone/renin ratio were similar to those for renin activity. This is the first study to report a significant association between renin activity and a marker of bone turnover and bone mineral density in generally healthy individuals. Also, there is evidence for significant genetic pleiotropy and, thus, there may be a shared biological mechanism underlying both the renin-angiotensin-aldosterone system and bone metabolism that is independent of hypertension

The cellular prion protein increases the uptake and toxicity of tdp-43 fibrils

Cytoplasmic aggregation of the primarily nuclear TAR DNA-binding protein 43 (TDP-43) affects neurons in most amyotrophic lateral sclerosis (ALS) and approximately half of frontotemporal lobar degeneration (FTLD) cases. The cellular prion protein, PrPC, has been recognized as a common receptor and downstream effector of circulating neurotoxic species of several proteins involved in neurodegeneration. Here, capitalizing on our recently adapted TDP-43 real time quaking induced reaction, we set reproducible protocols to obtain standardized preparations of recombinant TDP-43 fibrils. We then exploited two different cellular systems (human SH-SY5Y and mouse N2a neuroblastoma cells) engineered to express low or high PrPC levels to investigate the link between PrPC expression on the cell surface and the internalization of TDP-43 fibrils. Fibril uptake was increased in cells overexpressing either human or mouse prion protein. Increased internalization was associated with detrimental consequences in all PrP-overexpressing cell lines but was milder in cells expressing the human form of the prion protein. As described for other amyloids, treatment with TDP-43 fibrils induced a reduction in the accumulation of the misfolded form of PrPC, PrPSc, in cells chronically infected with prions. Our results expand the list of misfolded proteins whose uptake and detrimental effects are mediated by PrPC, which encompass almost all pathological amyloids involved in neurodegeneration

Paleozoic Crown Lungfishes from Gondwana foreshadow the Early Triassic Recovery Fauna

Modern lungfishes are renowned for tolerance of extreme environmental variation, which is thought to contribute to their abundance during the recovery from the Permo-Triassic Mass Extinction (PTME). However, the Paleozoic origins of this clade and its biogeographic context remains unclear, with a 60 Ma ghost lineage at the base of the crown lungfish diversification spanning much of the Upper Carboniferous and the entirety of the Permian. This gap is particularly perplexing given the exceptional record of archaic lungfishes within this interval, particularly within paleoequatorial Euramerica, but also within eastern Europe. One possibility is that the assembly of the crown lungfish bauplan from known Carboniferous and Permian archaic lungfish groups occurred rapidly in the recovery from the PTME. However, an alternative explanation is that the crown lungfish bauplan evolved earlier in geographic regions outside the well-sampled Carboniferous and Permian basins of Euramerica, Russia, and South Africa. The sudden appearance of a diverse crown lungfish fauna in the earliest Triassic would then represent a biogeographic release in response to climate or diversity trends associated with the PTME. New lungfish faunas from outside these basins provide an opportunity to test these hypotheses. Here we report a diverse lungfish fauna from the Early Permian Pedra de Fogo Formation (Parnaíba Basin, northeastern Brazil) comprised of abundant lungfish toothplates and rarer associated or articulated skeletal remains. This fauna lacks archaic lungfish taxa (e.g. sagenodontids, ctenodontids, and conchopomatids) characteristic of contemporary localities in equatorial Euramerica. Instead, the Parnaíba fauna preserves a diverse assemblage of derived lungfishes, including a gnathorhizid and several crown lungfishes (ceratodontiforms). The gnathorhizid is represented by abundant toothplates and several partial skulls, and shows similarities to the North American gnathorhizid genera Persephonichthys and Gnathorhiza. The ceratodontiform, which is represented by toothplates as well as several partial skulls and skeletons, shows affinities with Triassic ptychoceratodontids and arganodontids, currently considered early members of the lepidosireniform stem group. Comparison with lungfish toothplate assemblages from the Paraná Basin of southern Brazil shows that the lungfish assemblage from the Parnaíba basin is also present in the Middle Permian of Brazil, likely representing a persistent biogeographic province in western Gondwana. We hypothesize that the lungfish crown group originated early in western Gondwana, but remained biogeographically restricted until the PTME eliminated incumbent competition in better-known biogeographical provinces.Fil: Pardo, Jason. University of Calgary; CanadáFil: Kammerer, Christian. Museum Fur Naturkunde; AlemaniaFil: Marsicano, Claudia Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Angielczyk, Kenneth D.. Field Museum of National History; Estados UnidosFil: Fröbisch, Jörg. No especifíca;Fil: Smith, Roger M. H.. University of Cape Town; SudáfricaFil: Cisneros, Juan C.. Universidade Federal do Piaui; BrasilAnnual Meeting Society Vertebrate PaleontologyEstados UnidosSociety of Vertebrate Paleontolog

From Teamchef Arminius to Hermann Junior: glocalised discourse about a national foundation myth

If for much of the nineteenth and twentieth centuries, the ‘Battle of the Teutoburg Forest’, fought in 9 CE between Roman armies and Germanic tribes, was predominantly a reference point for nationalist and chauvinist discourses in Germany, the first decade of the twenty-first century has seen attempts to link public remembrance with local/regional identities on the one hand and international/intercultural contact on the other. In the run up to and during the ‘anniversary year’ of 2009, German media, sports institutions and various other official institutions articulating tourist, economic and political interests attempted to create a new ‘glocalised’ version of the public memory of the Teutoburg battle. Combining methods of Cognitive Linguistics and Critical Discourse Analysis, the paper analyses the narrative and argumentative topoi employed in this re-orientation of public memory, with a special emphasis on hybrid, post-national identity-construction. Das zweitausendjährige Gedenkjahr der „Schlacht im Teutoburger Wald“ im Jahr 2009 bot eine günstige Gelegenheit, die bis in die zweite Hälfte des 20. Jahrhunderts dominante Tradition nationalistisch–chauvinistischer Deutungen des Sieges von germanischen Stämmen über drei römische Legionen zu korrigieren und zu überwinden. Der Aufsatz analysiert mit Hilfe diskurslinguistischer Methoden die Anstrengungen regionaler Institutionen und Medien, die nationale Vereinnahmung des historischen Gedenkens kritisch zu thematisieren sowie neue, zum eine lokal situierte, zum andern international orientierte Identifikationsangebote anzubieten. Die Analyse zeigt, dass solche „de-nationalisierten“ Identifikationsangebote zwar teilweise auch früher verwendet wurden, aber heutzutage rekontextualisiert und auf innovative Weise in den Vordergrund gestellt werden

The impact of inlet boundary layer thickness on the unsteady aerodynamics of S-duct intakes

The need to reduce aero-engine emissions and direct operating costsis driving the civil aerospace sectortowards considering more integrated propulsion systems. Many of the proposed novel aircraft architectures employ convoluted intakes for either the aero-engine or propulsion system. These intakes are characterized by unsteady distortion that can hinder the performance and operability of the propulsion system. This work assessesthe impact of the inlet boundary layer on the unsteady aerodynamics of an S-duct intake using time-resolved particle image velocimetry at the aerodynamic interface plane.An increase in the boundary layer thickness at the intake inlet increasesthe flow unsteadiness on the swirl angle by up to 40% relativeto the baseline case. The azimuthal orientation of the inlet boundary layer modifies the intensity and topology of the most frequent swirl distortion pattern. For a relatively thick inlet boundary layer, the reduction of the dominant frequencies associated withthe unsteady swirl angle is postulated to be beneficial for the engine stability. Overall, this works gives guidelines for the integration between the intake and the engine across the range of potential inlet operating conditions

Energy landscape - a key concept for the dynamics of glasses and liquids

There is a growing belief that the mode coupling theory is the proper microscopic theory for the dynamics of the undercooled liquid above a critical temperature T_c. In addition, there is some evidence that the system leaves the saddlepoints of the energy landscape to settle in the valleys at this critical temperature. Finally, there is a microscopic theory for the entropy at the calorimetric glass transition T_g by Mezard and Parisi, which allows to calculate the Kauzmann temperature from the atomic pair potentials. The dynamics of the frozen glass phase is at present limited to phenomenological models. In the spirit of the energy landscape concept, one considers an ensemble of independent asymmetric double-well potentials with a wide distribution of barrier heights and asymmetries (ADWP or Gilroy-Phillips model). The model gives an excellent description of the relaxation of glasses up to about T_g/4. Above this temperature, the interaction between different relaxation centers begins to play a role. One can show that the interaction reduces the number of relaxation centers needed to bring the shear modulus down to zero by a factor of three.Comment: Contribution to the III Workshop on Nonequilibrium Phenomena in Supercooled Fluids, Glasses and Amorphous Materials, 22-27 September 2002, Pisa; 14 pages, 3 figures; Version 3 takes criticque at Pisa into account; final version 4 will be published in J.Phys.: Condens.Matte

Loss of the mammal-specific tectorial membrane component CEA cell adhesion molecule 16 (CEACAM16) leads to hearing impairment at low and high frequencies

The vertebrate-restricted carcinoembryonic antigen gene family evolves extremely rapidly. Among their widely expressed members, the mammal-specific, secreted CEACAM16 is exceptionally well conserved and specifically expressed in the inner ear. To elucidate a potential auditory function we inactivated murine Ceacam16 by homologous recombination. In young Ceacam16-/- mice the hearing threshold for frequencies below 10 kHz and above 22 kHz was raised. This hearing impairment progressed with age. A similar phenotype is observed in hearing-impaired members of Family 1070 with non-syndromic autosomal dominant hearing loss (DFNA4) who carry a missense mutation in CEACAM16. CEACAM16 was found in interdental and Deiters cells and was deposited in the tectorial membrane of the cochlea between postnatal day 12 and 15, when hearing starts in mice. In cochlear sections of Ceacam16-/- mice tectorial membranes were significantly more often stretched out as compared to wild-type mice where they were mostly contracted and detached from the outer hair cells. Homotypic cell sorting observed after ectopic cell surface expression of the carboxy-terminal immunoglobulin variable-like N2 domain of CEACAM16 indicated that CEACAM16 can interact in trans. Furthermore, Western blot analyses of membrane-bound CEACAM16 under reducing and non-reducing conditions demonstrated oligomerization via unpaired cysteines. Taken together, CEACAM16 probably can form higher order structures with other tectorial membrane proteins such as α-tectorin and β-tectorin and influences the physical properties of the tectorial membrane. Evolution of CEACAM16 might have been an important step for the specialization of the mammalian cochlea allowing hearing over an extended frequency range