384 research outputs found

    Linking the proximal tibiofibular joint to hominid locomotion: A morphometric study of extant species

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    Objectives: We perform a comparative assessment of shape variation of the proximal fibula in extant humans and great apes, intending to investigate the possible link between proximal fibular shape and locomotor patterns.Methods: Our sample includes 94 fibulae of 37 Homo sapiens, 15 Gorilla, 17 Pongo, and 25 Pan. Fibular morphology was investigated through three-dimensional (semi)landmark-based geometric morphometric methods.Results: We found unique features of the human fibular head compared to that of great apes (i.e., oblique articular surface, the presence of the styloid process, specific morphology of muscle attachment sites), supporting the functional role of this bone in relation to human obligate bipedalism. Great apes also showed distinctive traits in their proximal fibula morphology, in agreement with differences in locomotor behavior.Conclusion: The morphology of the proximal fibula in extant humans and great apes is indicative of locomotor behavior, offering the potential for the comparative analysis of fossil hominin remains

    Nonlinear Dirac operator and quaternionic analysis

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    Properties of the Cauchy-Riemann-Fueter equation for maps between quaternionic manifolds are studied. Spaces of solutions in case of maps from a K3-surface to the cotangent bundle of a complex projective space are computed. A relationship between harmonic spinors of a generalized nonlinear Dirac operator and solutions of the Cauchy-Riemann-Fueter equation are established.Comment: Cosmetic changes onl

    The Geometry and Moduli of K3 Surfaces

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    These notes will give an introduction to the theory of K3 surfaces. We begin with some general results on K3 surfaces, including the construction of their moduli space and some of its properties. We then move on to focus on the theory of polarized K3 surfaces, studying their moduli, degenerations and the compactification problem. This theory is then further enhanced to a discussion of lattice polarized K3 surfaces, which provide a rich source of explicit examples, including a large class of lattice polarizations coming from elliptic fibrations. Finally, we conclude by discussing the ample and Kahler cones of K3 surfaces, and give some of their applications.Comment: 34 pages, 2 figures. (R. Laza, M. Schutt and N. Yui, eds.

    Period- and mirror-maps for the quartic K3

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    We study in detail mirror symmetry for the quartic K3 surface in P3 and the mirror family obtained by the orbifold construction. As explained by Aspinwall and Morrison, mirror symmetry for K3 surfaces can be entirely described in terms of Hodge structures. (1) We give an explicit computation of the Hodge structures and period maps for these families of K3 surfaces. (2) We identify a mirror map, i.e. an isomorphism between the complex and symplectic deformation parameters, and explicit isomorphisms between the Hodge structures at these points. (3) We show compatibility of our mirror map with the one defined by Morrison near the point of maximal unipotent monodromy. Our results rely on earlier work by Narumiyah-Shiga, Dolgachev and Nagura-Sugiyama.Comment: 29 pages, 3 figure

    Insulin, Hyperglycemia, and Severe Retinopathy of Prematurity in Extremely Low-Birth-Weight Infants

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    Objective This study aims to determine the association between hyperglycemia, insulin therapy, and severe retinopathy of prematurity (ROP) in extremely low-birth-weight (ELBW) infants. Study Design In this retrospective database study, we included all ELBW infants who were 180 mg/dL. Covariates were GA, small for GA status, discharge year, sex, Apgar score at 5 minutes, mechanical ventilation, oxygen use, bacteremia, and postnatal steroid exposure. We defined severe ROP as ROP requiring bevacizumab, cryotherapy, laser therapy, or vitrectomy. Sensitivity analysis using BG > 150 mg/dL and > 200 mg/dL was performed. Results A total of 24,548 infants were included; 2,547 (10%) had severe ROP. Hyperglycemia alone was not associated with severe ROP (odds ratio [OR], 0.88; 95% confidence interval [CI], 0.66-1.17). Hyperglycemia and insulin use were not associated with severe ROP (OR, 1.43; 95% CI, 0.91-2.23). BG > 150 mg/dL and insulin use were associated with severe ROP (OR, 1.34; 95% CI, 1.02-1.76). Conclusions Hyperglycemia alone was not associated with severe ROP in ELBW infants. However, we did observe a possible trend between the use of insulin and severe ROP.National Center for Advancing Translational Sciences of the National Institutes of Health (NIH)U.S. governmentNational Institute of Child Health and Human DevelopmentNIHNational Center for Advancing Translational Sciences of the NIHU.S. Food and Drug AdministrationCempra PharmaceuticalsDuke Univ, Dept Pediat, Sch Med, Durham, NC 27706 USADuke Univ, Sch Med, Duke Clin Res Inst, Durham, NC USAKK Womens & Childrens Hosp, Childrens Intens Care Unit, Singapore, SingaporeUniv Fed Sao Paulo, Ecola Paulista Med, Div Neonatal Med, Sao Paulo, BrazilUniv N Carolina, Dept Pediat, Chapel Hill, NC USAMEDNAX Inc, Pediat Med Grp, Jacksonville, FL USAUniv Fed Sao Paulo, Ecola Paulista Med, Div Neonatal Med, Sao Paulo, BrazilNIH: UL1TR001117U.S. government: HHSN267200700051CNational Institute of Child Health and Human Development: K23HD068497National Institute of Child Health and Human Development: HHSN275201000003INational Institute of Child Health and Human Development: 1R01-HD081044-01National Center for Advancing Translational Sciences of the NIH: UL1TR001117U.S. Food and Drug Administration: 1R18-FD005292-01Cempra Pharmaceuticals: HHS0100201300009CWeb of Scienc

    Flight Envelope Information-Augmented Display for Enhanced Pilot Situation Awareness

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    This paper presents an interface system display which is conceived to improve pilot situation awareness with respect to a flight envelope protection system developed for a mid-sized transport aircraft. The new display is designed to complement existing cockpit displays, and to augment them with information that relates to both aircraft state and the control automation itself. In particular, the proposed display provides cues about the state of automation directly in terms of pilot control actions, in addition to flight parameters. The paper also describes a forthcoming evaluation test plan that is intended to validate the developed interface by assessing the relevance of the displayed information, as well as the adequacy of the display layout

    New insights on Celtic migration in Hungary and Italy through the analysis of non-metric dental traits

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    The Iron Age is characterized by an extended interweaving of movements by Celts in Europe. Several waves of Celts from Western and Central Europe migrated southeast and west from the core area of the La Téne culture (between Bourgogne and Bohemia). Through the analysis of non-metric dental traits, this work aims to understand the biological relationship among Celtic groups arrived in Italy and the Carpathian Basin, as well as between local populations and Celtic newcomers. A total of 10 non-metric dental traits were analyzed to evaluate biological affinities among Celts (Sopron-Krautacker and Pilismarót-Basaharc) and Scythians-related populations from Hungary (Tápiószele), Celts from continental Europe (Switzerland and Austria), two Iron Age Etruscan-Celtic sites from northern Italy (Monterenzio Vecchio and Monte Bibele), 13 Iron Age central-southern Italic necropolises, and the northern Italian Bronze Age necropolis of Scalvinetto. Strontium isotopes were measured on individuals from the necropolis of Monte Bibele to infer their local or non-local origin. Results highlight the existence of statistically significant differences between Celts and autochthonous Italian groups. Celtic groups from Hungary and Italy (i.e., non-local individuals of Monterenzio Vecchio and Monte Bibele) share a similar biological background, supporting the historical records mentioning a common origin for Celts migrated to the eastern and southern borders of today’s Europe. The presence of a supposed Steppean ancestry both in Celts from Hungary and Celts from northern Italy corroborates the hypothesis of the existence of a westward migration of individuals and genes from the Steppe towards northern Italy during the Bronze and Iron Age, which contributed to the biological variability of pre-Celtic and later Celtic populations, respectively. Conversely, individuals from central-southern Italy show an autochthonous pre-Iron Age background. Lastly, this work supports the existence of Celtic migratory routes in northern Italy, as shown by biological and cultural admixture between Celts and Italics living together

    Exploring directional and fluctuating asymmetry in the human palate during growth

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    open24siObjectives: Palate morphology is constantly changing throughout an individual's lifespan, yet its asymmetry during growth is still little understood. In this research, we focus on the study of palate morphology by using 3D geometric morphometric approaches to observe changes at different stages of life, and to quantify the impact of directional and fluctuating asymmetry on different areas at different growth stages. Materials and Methods: The sample consists of 183 individuals (1–72 years) from two identified human skeletal collections of 19th and early 20th Century Italian contexts. A 3D-template of 41 (semi)landmarks was applied on digital palate models to observe morphological variation during growth. Results: Asymmetrical components of the morphological structure appears multidirectional on the entire palate surface in individuals <2 years old and become oriented (opposite bilateral direction) between 2 and 6 years of age. Specifically, directional asymmetry differentially impacts palate morphology at different stages of growth. Both the anterior and posterior palate are affected by mild alterations in the first year of life, while between 2 and 6 years asymmetry is segregated in the anterior area, and moderate asymmetry affects the entire palatal surface up to 12 years of age. Our results show that stability of the masticatory system seems to be reached around 13–35 years first by females and then males. From 36 years on both sexes show similar asymmetry on the anterior area. Regarding fluctuating asymmetry, inter-individual variability is mostly visible up to 12 years of age, after which only directional trends can be clearly observed at a group level. Discussion: Morphological structure appears instable during the first year of life and acquires an opposite asymmetric bilateral direction between 2 and 6 years of age. This condition has been also documented in adults; when paired with vertical alteration, anterior/posterior asymmetry seems to characterize palate morphology, which is probably due to mechanical factors during the lifespan. Fluctuating asymmetry is predominant in the first period of life due to a plausible relationship with the strength of morphological instability of the masticatory system. Directional asymmetry, on the other hand, shows that the patterning of group-level morphological change might be explained as a functional response to differential inputs (physiological forces, nutritive and non-nutritive habits, para-masticatory activity as well as the development of speech) in different growth stages. This research has implications with respect to medical and evolutionary fields. In medicine, palate morphology should be considered when planning orthodontic and surgical procedures as it could affect the outcome. As far as an evolutionary perspective is concerned the dominance of directional asymmetries in the masticatory system could provide information on dietary and cultural habits as well as pathological conditions in our ancestors.embargoed_20220511Oxilia G.; Menghi Sartorio J.C.; Bortolini E.; Zampirolo G.; Papini A.; Boggioni M.; Martini S.; Marciani F.; Arrighi S.; Figus C.; Marciani G.; Romandini M.; Silvestrini S.; Pedrosi M.E.; Mori T.; Riga A.; Kullmer O.; Sarig R.; Fiorenza L.; Giganti M.; Sorrentino R.; Belcastro M.G.; Cecchi J.M.; Benazzi S.Oxilia G.; Menghi Sartorio J.C.; Bortolini E.; Zampirolo G.; Papini A.; Boggioni M.; Martini S.; Marciani F.; Arrighi S.; Figus C.; Marciani G.; Romandini M.; Silvestrini S.; Pedrosi M.E.; Mori T.; Riga A.; Kullmer O.; Sarig R.; Fiorenza L.; Giganti M.; Sorrentino R.; Belcastro M.G.; Cecchi J.M.; Benazzi S
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