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The albertosaurines Albertosaurus sarcophagus and Gorgosaurus libratus are among the best represented tyrannosaurids, known from nearly complete growth series. These specimens provide an opportunity to study mandibular biomechanical properties and tooth morphology to infer changes in feeding behaviour and bite force through ontogeny in tyrannosaurids. Mandibular force profiles reveal that the symphyseal region of albertosaurines is consistently stronger in bending than the mid-dentary region, indicating that the anterior extremity of the jaws played an important role in prey capture and handling through ontogeny. The symphyseal region was better adapted to withstand torsional stresses than in most non-avian theropods, but not to the extent seen in Tyrannosaurus rex, suggesting that albertosaurine feeding behaviour may have involved less bone crushing or perhaps relatively smaller prey than in Tyrannosaurus rex. The constancy of these biomechanical properties at all known growth stages indicates that although albertosaurines maintained a similar feeding strategy through ontogeny, prey size/type had to change between juvenile and mature individuals. This ontogenetic dietary shift likely happened when individuals reached a mandibular length of ~58 cm, a size at which teeth shift from ziphodont to incrassate in shape and bite force begins to increase exponentially. The fact that large albertosaurines were capable of generating bite forces equivalent to similar-sized tyrannosaurines suggests that no significant differences in jaw-closing musculature existed between the two clades and that the powerful bite of Tyrannosaurus rex is the result of its large body size rather than of unique adaptations related to a specialized ecology. Key words: feeding behaviour, paleoecology, biomechanics, mandibular force profile, Tyrannosauridae, diet. Les albertosaurines Albertosaurus sarcophagus et Gorgosaurus libratus figurent parmi les tyrannosaurides les mieux representes, les connaissances a leur sujet reposant sur des series de croissance quasi completes. Ces specimens offrent l'occasion d'etudier les proprietes biomecaniques des mandibules et la morphologie des dents pour en inferer des changements du mode d'alimentation et de la force de morsure au fil de l'ontogenese chez les tyrannosaurides. Des profils de force des mandibules revelent que la region symphysaire des albertosaurines est toujours plus resistante en flexion que la region dentaire mediane, ce qui indique que l'extremite anterieure des machoires jouait un important role dans la capture et la manipulation des proies tout au long de l'ontogenese. La region symphysaire des albertosaurines etait mieux adaptee a resister aux contraintes en torsion que celle de la plupart des theropodes non aviaires, mais pas autant que celle de Tyrannosaurus rex, ce qui indiquerait que le broyage d'os etait possiblement un aspect moins important de leur comportement d'alimentation ou que leurs proies etaient plus petites que celles de Tyrannosaurus rex. La constance de ces proprietes biomecaniques a toutes les etapes connues de la croissance indique que, bien que la strategie d'alimentation des albertosaurines ne variait pas beaucoup au filde l'ontogenese, la taille et le type de proies acquises devaient changer entre les individus juveniles et matures. Cette transition ontogenetique de l'alimentation se produisait vraisemblablement lorsque les individus atteignaient une longueur des mandibules de ~58 cm, taille a laquelle la forme des dents passe de ziphodonte a epaissie et la force de morsure commence a augmenter de facon exponentielle. Le fait que les grands albertosaurines etaient capables de produire des forces de morsure equivalentes a celles de tyrannosaurines de meme taille donne a penser qu'il n'y avait aucune difference significative de la musculature de fermeture des machoires entre les deux clades et que la puissante morsure de Tyrannosaurus rex est le resultat de sa grande taille plutot que d'adaptations singulieres reliees a une specialisation ecologique. [Traduit par la Redaction] Mots-cles: mode d'alimentation, paleoecologie, biomecanique, profil de force des mandibules, tyrannosauride, regime alimentaire., Introduction Tyrannosaurids were the apex predators of Late Cretaceous ecosystems in Asia and North America. Originating from small-bodied ancestors that lived during the Middle Jurassic through mid-Cretaceous, tyrannosaurids may have [...]

One of the challenges inherent in automotive LCD relates to the response characteristics displayed in low‐temperature environments. In this study, we devised a panel by incorporating heater wires into the Thin‐Film Transistor (TFT) substrate of the LCD, which was optimized through thermal simulations. Additionally, we validated the enhanced response time in low‐temperature environments by utilizing the optimized heater wires within the LCD cell for automotive applications. [ABSTRACT FROM AUTHOR]

Background: Distal humerus fracture in the elderly is a challenging fracture for orthopedic surgeons. Non-union is one of the serious complications of distal humerus fracture after surgery. This retrospective multicenter study aimed to estimate the incidence of distal humeral non-union after open reduction and internal fixation, determine factors related to non-union, and compare the postoperative results of cases with non-union to cases with the union. Methods: Among 423 patients diagnosed with distal humeral fracture and who were treated by surgical therapy in 2010–2020 from our database called TRON. Only 190 subjects met the inclusion criteria. We performed a logistic regression analysis with the presence of non-union as the response variable to examine risk factors. We compare the Mayo Elbow Performance Scores of cases with non-union to cases with the union. Results: Non-union occurred after surgery in 15 patients (7.9%). The logistic regression analysis showed that body mass index<20 kg/m2 and ≥25 kg/m2, and ≤3 screws in the articular segment were significant explanatory factors for non-union (odds ratio 10.4 and 47.8, respectively). The Mayo Elbow Performance Scores were significantly worse in patients with non-union. Discussion: Low and high body mass index and three or fewer screws in the articular segment might be risk factors for non-union of distal humerus fracture in the elderly. Non-union is associated with poor clinical outcomes. [ABSTRACT FROM AUTHOR]

Since the first discovery of dinosaur eggs announced by the American Museum of Natural History (central Asiatic expeditions to Mongolia) in 1923, these fossils became widely recognised from Mesozoic strata in Asia and elsewhere. In the 1920s, and actually before 1923, dinosaur eggs had been collected from another part of Asia, specifically Liaoning Province in northeastern China. From 1921 to the late 1920s, five eggs were collected from the Cenomanian Quantou Formation during construction, and thus represent an important historic collection as some of the earliest dinosaur eggs discovered in Asia. Here, we describe one egg from this collection and assign it to Paraspheroolithus irenensis, an egg taxon that likely belonged to hadrosaur dinosaurs. The egg is approximately 7 × 8 cm in diameter, with eggshell that displays typical spheroolithid microstructure and is just over a millimetre in thickness. Paraspheroolithus irenensis is shown to be the most widespread spheroolithid oospecies in China, and our comparative work extends its geographic range to northeastern most China. The Quantou Formation thus has yielded at least three spheroolithid oospecies, indicating the potential for a diversity of hadrosaur or related ornithopod species in the region at that time. [ABSTRACT FROM AUTHOR]

North America is known for its rich uppermost Cretaceous record of dinosaur egg remains, although a notable fossil gap exists during the lower Maastrichtian. Here we describe a diverse dinosaur eggshell assemblage from the St. Mary River Formation of southern Alberta that, in conjunction with recently described eggs from the same formation in Montana, helps fill this gap and sheds light on the dinosaur diversity in this poorly fossiliferous formation. Three theropod eggshell types (Continuoolithus cf. C. canadensis, Montanoolithus cf. M. strongorum, and Prismatoolithus cf. P. levis) and one ornithopod (Spheroolithus cf. S. albertensis), are reported from Albertan exposures of the St. Mary River Formation, increasing the ootaxonomic diversity of the formation from two to five ootaxa. The taxonomic composition of the eggshell assemblage is consistent with the dinosaurian fauna known from the St. Mary River Formation based on skeletal remains. Spheroolithus eggshells constitute the majority of identifiable eggshells in our assemblage, a trend also observed in several other Upper Cretaceous formations from North America. Continuoolithus is shown to be synonymous with Spongioolithus, thus expanding the Maastrichtian geographic range of the ootaxon to include Utah. The St. Mary River eggshell assemblage supports a general trend of increase in eggshell thickness among theropod ootaxa from the uppermost Santonian through the Maastrichtian, which is inferred to reflect an increase in body size among some clades of small theropods through the Upper Cretaceous. Eggshell preservation in the St. Mary River Formation may be related to the semiarid climatic and environmental conditions that prevailed. Si l'Amerique du Nord est reconnue pour ses strates cretacees sommitales riches en restes d'oeufs de dinosaure, une lacune notable dans le registre fossile caracterise le Maastrichtien inferieur. Nous decrivons un assemblage varie de coquilles d'oeuf de dinosaure de la Formation de St. Mary River du sud de l'Alberta qui, combine a des oeufs decrits recemment de la meme formation au Montana, aide a combler cette lacune et jette un nouvel eclairage sur la diversite des dinosaures dans cette formation peu fossilifere. Trois types de coquille de theropodes (Continuoolithus cf. C. canadensis, Montanoolithus cf. M. strongorum et Prismatoolithus cf. P. levis) et un d'ornithopode (Spheroolithus cf. S. albertensis) se retrouvent dans des affleurements albertains de la Formation de St. Mary River, ce qui accroit la diversite ootaxonomique de la formation de deux a cinq ootaxons. La composition taxonomique de l'assemblage de coquilles d'oeuf concorde avec la faune dinosaurienne de la Formation de St. Mary River connue a partir de restes oussex. Les coquilles d'oeuf de Spheroolithus constituent la majorite des coquilles identifiables dans notre assemblage, une tendance aussi observee dans plusieurs autres formations du Cretace superieur de l'Amerique du Nord. Il est demontre que les ootaxons Continuoolithus et Spongioolithus sont synonymes, ce qui elargit l'aire de repartition geographique maastrichtienne de l'ootaxon pour y inclure l'Utah. L'assemblage de coquilles d'oeuf de la Formation de St. Mary River appuie l'interpretation d'une tendance generale d'augmentation de l'epaisseur des coquilles d'oeuf chez les ootaxons de theropodes du Santonien sommital jusqu'au Maastrichtien, ce qui refleterait une augmentation de la taille de certains clades de petits theropodes jusqu'au Cretace superieur. La preservation de coquilles d'oeuf dans la Formation de St. Mary River pourrait etre associee aux conditions climatiques et environnementales semi-arides qui prevalaient a l'epoque. [Traduit par la Redaction], Introduction Abundant dinosaur egg remains have been discovered in Upper Cretaceous formations of North America, the vast majority of which are known from Campanian deposits (Horner and Makela 1979; Hirsch [...]