81 research outputs found

    Collective Path Connecting the Oblate and Prolate Local Minima in 68Se

    Full text link
    By means of the adiabatic self-consistent collective coordinate method and the pairing plus quadrupole interaction, we have obtained the selfconsistent collective path connecting the oblate and prolate local minima in 68Se for the first time. Along the collective path, the triaxial deformation parameter (gamma) changes between 0 and 60 (degree) keeping the axially symmetric deformation parameter (beta) approximately constant, indicating the importance of triaxial deformation dynamics in the oblate-prolate shape coexistence phenomena.Comment: 6 pages including 6 eps figure

    Prolonged maturation of prefrontal white matter in chimpanzees

    Get PDF
    Delayed maturation in the prefrontal cortex, a brain region associated with complex cognitive processing, has been proposed to be specific to humans. However, we found, using a longitudinal design, that prefrontal white matter volume in chimpanzees increased gradually with age, and the increase appears to continue beyond the onset of puberty, as in humans. This provides the first evidence for a prolonged period of prefrontal connection elaboration in great apes

    The SKX 1084 hominin patella from Swartkrans Member 2, South Africa: An integrated analysis of its outer morphology and inner structure

    Get PDF
    SKX 1084 is an isolated partial patella from Swartkrans Member 2, South Africa, attributed to a small-bodied Paranthropus robustus. This study provides complementary information on its outer conformation and, for the first time for a fossil hominin patella, documents its inner structure in the perspective of adding biomechanically-related evidence to clarify its identity. We used X-ray micro-tomography to investigate SKX 1084 and to extract homologous information from a sample of 12 recent human, one Neanderthal, and two adult Pan, patellae. We used geometric morphometrics to compare the outer equatorial contours. In SKX 1084, we identified two cancellous bony spots suitable for textural assessment (trabecular bone volume fraction, trabecular thickness, degree of anisotropy), and two related virtual slices for measuring the maximum cortico-trabecular thickness (CTT) of the articular surface. SKX 1084 shows a more complex articular shape than that for Pan, but still simpler than typical in Homo sapiens. At all sites, its CTT is thinner compared to Pan and approaches the condition in humans. This is also true for the expanded volume of the cancellous network. However, at both investigated spots, SKX 1084 is systematically intermediate between Homo and Pan for trabecular bone volume fraction and trabecular thickness, a pattern already shown in previous analyses on other Paranthropus postcranial remains. In the absence of any structural signal from patellae unambiguously sampling Paranthropus, as well as of comparable evidence extracted from specimens representing early Homo, our results do not allow rejection of the original taxonomic attribution of SKX 1084

    Identification of functionally-related adaptations in the trabecular network of the proximal femur and tibia of a bipedally-trained Japanese macaque

    Get PDF
    The axial and appendicular skeleton of Japanese macaques (Macacca fuscata) trained to adopt ipedal posture and locomotion display a number of functionally-related external and internal macro- and micro-morphological changes, including site-specific cortical and trabecular bone adaptations. In this study we use high-resolution microtomography scanning to analyse the 3D distribution of trabecular architecture of the proximal femur and proximal tibia of Sansuke, a male individual trained in bipedal performances for eight years, as well as five wild individuals. The distribution and architecture of trabecular bone in the femoral head of Sansuke is distinct from that found in wild M. fuscata individuals, with a unique bone reinforcement around the region of the fovea capitis. Conversely, wild individuals exhibit two pillar-like, high-density structures (converging in an inverted cone) that reach distinct regions of the posterior and anterior surfaces of the femoral head. For Sansuke’s proximal tibia, contrary to previous observations from the cortico-trabecular complex distribution at the plateau, our results do not show a more asymmetric distribution between medial and lateral condyles with a medial reinforcement. Additionally, relative bone volume in this region is not significantly higher in Sansuke. However, we observed a slightly more medially placed bone reinforcement in the lateral condyle compared to the wild individuals as well as a slightly higher trabecular bone anisotropy in the medial than in the lateral condyle not observed in the wild individuals. These analyses provide new evidence about the nature and extent of functionally-related adaptive arrangements of the trabecular network at the coxofemoral and the knee joints in individuals recurrently experiencing atypical load

    New femoral remains of <i>Nacholapithecus kerioi</i>: Implications for intraspecific variation and Miocene hominoid evolution

    Get PDF
    The middle Miocene stem kenyapithecine Nacholapithecus kerioi (16-15 Ma; Nachola, Kenya) is represented by a large number of isolated fossil remains and one of the most complete skeletons in the hominoid fossil record (KNM-BG 35250). Multiple fieldwork seasons performed by Japanese-Kenyan teams during the last part of the 20th century resulted in the discovery of a large sample of Nacholapithecus fossils. Here, we describe the new femoral remains of Nacholapithecus. In well-preserved specimens, we evaluate sex differences and within-species variation using both qualitative and quantitative traits. We use these data to determine whether these specimens are morphologically similar to the species holotype KNM-BG 35250 (which shows some plastic deformation) and to compare Nacholapithecus with other Miocene hominoids and extant anthropoids to evaluate the distinctiveness of its femur. The new fossil evidence reaffirms previously reported descriptions of some distal femoral traits, namely the morphology of the patellar groove. However, results also show that relative femoral head size in Nacholapithecus is smaller, relative neck length is longer, and neck-shaft angle is lower than previously reported for KNM-BG 35250. These traits have a strong functional signal related to the hip joint kinematics, suggesting that the morphology of the proximal femur in Nacholapithecus might be functionally related to quadrupedal-like behaviors instead of more derived antipronograde locomotor modes. Results further demonstrate that other African Miocene apes (with the exception of Turkanapithecus kalakolensis) generally fall within the Nacholapithecus range of variation, whose overall femoral shape resembles that of Ekembo spp. and Equatorius africanus. Our results accord with the previously inferred locomotor repertoire of Nacholapithecus, indicating a combination of generalized arboreal quadrupedalism combined with other antipronograde behaviors (e.g., vertical climbing)

    Thioredoxin-1 and oxidative stress status in pregnant women at early third trimester of pregnancy: relation to maternal and neonatal characteristics

    Get PDF
    This study examined the clinical and biological importance of thioredoxin-1, a redox-active defensive protein that controls multiple biological functions, in pregnant women. We measured serum concentrations of thioredoxin-1, total hydroperoxides, and redox potential in 60 pregnant women at the early third trimester: gestational age of 27-29 weeks. The thioredoxin-1 concentration (mean +/- SD) was 90 +/- 42 ng/ml. Total hydroperoxides was 471 +/- 105 U.CARR (1 U.CARR = 0.08 mg/dl H2O2). Redox potential was 2142 +/- 273 mu mol/l. The total hydroperoxides: redox potential ratio (oxidative stress index) was 0.23 +/- 0.08. Thioredoxin-1, total hydroperoxides, and oxidative stress index were higher and redox potential was lower than in blood of healthy adults. Total hydroperoxides and redox potential were mutually correlated significantly and negatively. Thioredoxin-1 correlated significantly and negatively and redox potential correlated significantly and positively with body weight and body mass index. Thioredoxin-1 and redox potential correlated significantly and positively with uric acid and albumin, respectively. Thioredoxin-1 and oxidative stress index correlated significantly and negatively and redox potential significantly and positively with neonatal birth weight. These results suggest that high concentrations of thioredoxin-1 are linked to high oxidative stress status in pregnant women and that neonatal birth weight is affected by the maternal oxidative condition during later pregnancy

    Human shoulder development is adapted to obstetrical constraints

    Get PDF
    ヒトは小さく生まれて大きく育つ --その秘密は鎖骨にあり--. 京都大学プレスリリース. 2022-04-13.In humans, obstetrical difficulties arise from the large head and broad shoulders of the neonate relative to the maternal birth canal. Various characteristics of human cranial development, such as the relatively small head of neonates compared with adults and the delayed fusion of the metopic suture, have been suggested to reflect developmental adaptations to obstetrical constraints. On the other hand, it remains unknown whether the shoulders of humans also exhibit developmental features reflecting obstetrical adaptation. Here we address this question by tracking the development of shoulder width from fetal to adult stages in humans, chimpanzees, and Japanese macaques. Compared with nonhuman primates, shoulder development in humans follows a different trajectory, exhibiting reduced growth relative to trunk length before birth and enhanced growth after birth. This indicates that the perinatal developmental characteristics of the shoulders likely evolved to ease obstetrical difficulties such as shoulder dystocia in humans

    Usefulness of indocyanine green injection during ultrasound-guided liver biopsy for the diagnosis of small hepatocellular carcinoma.

    Get PDF
    To diagnose hepatocellular carcinoma (HCC) functionally and immediately, we examined the usefulness of indocyanine green (ICG) injection during ultrasound-guided liver biopsy. Liver specimens were obtained after intravenous ICG injection by ultrasound-guided biopsy from 251 space-occupying lesions (SOL) in 136 patients. The tissues were immediately examined for ICG uptake using an infrared Vidicon camera and were also subjected to histopathological examinations. Of the 112 ICG-negative biopsy specimens, 105 were histologically diagnosed as HCC, 6 as dysplastic nodules (DN) and 1 as a regenerative nodule (RN). Of the 139 ICG-positive specimens, 18 were diagnosed as HCC, 1 as DN and 120 as RN. The sensitivity of the absence of ICG uptake (SEAIU), the specificity of the absence of ICG uptake (SPAIU), and the positive predictive value of the absence of ICG uptake (PPAIU) for the diagnosis of HCC were 85.3%, 94.5% and 93.8%, respectively. Of the 251 SOLs, 184 were less than 2 cm. SEAIU, SPAIU and PPAIU for the diagnosis of these small HCC were 85.3%, 94.5% and 91.4%, respectively. These results support the reliability of ICG injection during ultrasound-guided liver biopsy to diagnose even small HCC.</p

    Reassessment of the phylogenetic relationships of the late Miocene apes Hispanopithecus and Rudapithecus based on vestibular morphology

    Get PDF
    Late Miocene great apes are key to reconstructing the ancestral morphotype from which earliest hominins evolved. Despite consensus that the late Miocene dryopith great apes Hispanopithecus laietanus (Spain) and Rudapithecus hungaricus (Hungary) are closely related (Hominidae), ongoing debate on their phylogenetic relationships with extant apes (stem hominids, hominines, or pongines) complicates our understanding of great ape and human evolution. To clarify this question, we rely on the morphology of the inner ear semicircular canals, which has been shown to be phylogenetically informative. Based on microcomputed tomography scans, we describe the vestibular morphology of Hispanopithecus and Rudapithecus, and compare them with extant hominoids using landmark-free deformation-based three-dimensional geometric morphometric analyses. We also provide critical evidence about the evolutionary patterns of the vestibular apparatus in living and fossil hominoids under different phylogenetic assumptions for dryopiths. Our results are consistent with the distinction of Rudapithecus and Hispanopithecus at the genus rank, and further support their allocation to the Hominidae based on their derived semicircular canal volumetric proportions. Compared with extant hominids, the vestibular morphology of Hispanopithecus and Rudapithecus most closely resembles that of African apes, and differs from the derived condition of orangutans. However, the vestibular morphologies reconstructed for the last common ancestors of dryopiths, crown hominines, and crown hominids are very similar, indicating that hominines are plesiomorphic in this regard. Therefore, our results do not conclusively favor a hominine or stem hominid status for the investigated dryopiths.DATA AVAILABITY : The 3D mesh data have been deposited in MorphoSource, https://morphosource.org/ (Rudapithecus hungaricus: RUD:77 R: https://doi.org/10.17602/M2/M126214; RUD:77 L: https://doi.org/10.17602/M2/M126215; RUD:200: https://doi.org/10.17602/M2/M126216; Hispanopithecus laietanus: IPS:18000: https://doi.org/10.17602/M2/M126217; Nacholapithecus kerioi: KNM:BG:42744: https://doi.org/10.17602/M2/M166427; Oreopithecus bambolii: NMB:BAC:208: https://doi.org/10.17602/M2/M166428).The Agencia Estatal de Investigación; the Generalitat de Catalunya (CERCA Programme); the consolidated research groups 2017 SGR 86 and 2017 SGR 116 GRC; and the French Centre National de la Recherche Scientifique.https://www.pnas.orghj2022Anatom
    corecore