bluuebunny/crossref_metadata_2025_split huggingface dataset:
Histological reconstruction of crown formation times and initial root formation times in a modern human child
Authors: Dean M. C. , Beynon A. D. 
Published: February 2006

AbstractPrevious qualitative studies on root growth in hominoids have suggested that the early stages of root growth in modern human teeth are slower than in great apes, but no quantitative data on root extension rates exist for modern human teeth. The primary objective of this study was to use incremental markings in the crowns of teeth to provide information about crown formation times and early root formation times. This study provides a detailed description of a single unaged child from Spitalfields, London, and presents an internally consistent model of incremental growth in crowns and roots of different teeth of this individual. We describe methods for determining times of initial mineralization in different teeth in the same individual. Scanning electron micrographs of perikymata on tooth surfaces and histological sections of teeth were prepared and analyzed. Total crown formation times were 4.4 years in the lower I1, 4.9 years in the lower 12, and 3.1 years in the upper M1. Average root extension rates indicate that during the first 2 or 3 mm of root growth in the lower permanent incisors and upper first permanent molar the average root extension rate was between 2.9 and 3.8 μm per day. This rate is similar to the rate of enamel extension in the last portion of cervical enamel formed in modern human anterior teeth. These root extension rates are approximately four times slower than similar rates calculated for ape teeth (Beynon et al: Am. J. Phys. Anthropol., 1991), a highly significant difference. The implications of these findings for comparative studies of dental development in early hominids and modern humans are discussed.
Compact bone distribution and biomechanics of early hominid mandibles
Authors: Daegling D. J. , Grine F. E. 
Published: February 2006

AbstractThis investigation explores the effects of compact bone distribution on the biomechanical properties of the postcanine mandibular corpus of the fossil hominid taxa Australopithecus africanus and Paranthropus robustus The mandibles of extant great apes, modern humans, and the fossil hominids are examined by computed tomography (CT), and compact bone contours are used to calculate cross‐sectional biomechanical properties (cortical area, second moments of area, and Bredt's formula for torsional strength). The relative amount of compact bone is comparable in the modern and fossil mandibles, but the mechanical properties of A. africanus and P. robustus jaws are distinct in terms of the ratio of minimum to maximum second moments of area. This difference most likely represents a structural response to elevated torsional moments in the fossil hominids. Although the relative amount of compact bone in cross‐section does not differ significantly between taxa by statistical criteria, A. africanus utilizes less cortical bone than P. robustus in the same manner in which Pongo is separated from the condition in other extant large‐bodied hominoids. It has been suggested that the phenomenon of mandibular “robusticity” (expressed as an index of corpus breadth/corpus height) may be an effect of postcanine megadontia and/or reduced canine size in the australopithecines. Results presented here, however, indicate that it is unlikely that either factor adequately accounts for mandibular size and shape variation in early hominids.
Is the Narmada hominid an Indian Homo erectus?
Authors: Kennedy Kenneth A. R. , Sonakia Arun , Chiment John , Verma K. K. 
Published: February 2006

AbstractIn 1982 a fossil hominid calvaria was found in a middle Pleistocene deposit in the central Narmada valley of Madhya Pradesh, India, and was assigned to the new taxon Homo erectus narmadensis. Subsequently, morphometric studies of the specimen were conducted by two separate research teams from France and the United States, both in collaboration with Indian colleagues. Results of the most recent study, which includes morphometric and comparative investigations, lead to the conclusion that “Narmada Man” is appropriately identified as Homo sapiens. While the calvaria shares some anatomical features with Asian Homo erectus specimens, it exhibits a broader suite of morphological and mensural characteristics suggesting affinities with early Homo sapiens fossils from Asia, Europe, and Africa as well as demonstrating that the Narmada calvaria possesses some unique anatomical features, perhaps because the specimen reflects the incoherent classificatory condition of the genus Homo.
Percent osteonal bone versus osteon counts: The variable of choice for estimating age at death
Authors: Stout Sam D. , Stanley Sarah C. 
Published: February 2006

AbstractAhlqvist and Damsten's (1969) modification of the Kerley (1965) method for histological age estimation uses percent osteonal bone, rather than actual osteon counts, in order to eliminate the difficulty of distinguishing between intact and fragmentary osteons. Since their method has been developed for the femur only, and several more recent methods have been proposed that utilize percent osteonal bone, a study was undertaken to ascertain the relative value of percent osteonal bone compared with osteon counts to estimate age at death for the radius, tibia, and fibula.First the question of how much of the cross‐section of a bone should be sampled was addressed by comparing the results of regression against age for percent osteonal bone derived from sampling only four fields with those derived from the entire cross‐section of the radius. A significant age association was found only when the entire cross‐section was sampled.In order to evaluate the relative merit of using either percent osteonal bone, or osteon counts to estimate age, each variable was regressed against age predictor.Finally, a repeated measures analysis of variance revealed that percent osteonal bone and osteon counts both differ among the three bones within an individual.Based upon these results, osteon counts, rather than percent osteonal bone, should be the variable of choice when developing histological age predicting methods.
Allometry and prediction in Hominoids: A solution to the problem of intervening variables
Authors: Hartwig‐Scherer Sigrid , Martin Robert D. 
Published: February 2006

AbstractTo avoid misinterpretation of allometric exponents determined from interspecific allometric comparisons, specific conditions must be met with respect to the common reference variable. Body weight is considered to be the best general indication of overall size and is hence widely acknowledged to be the most suitable reference variable. However, because of the paucity of recorded body weights for museum specimens, various comparative studies have used other size indicators as intervening variables, although the allometric relationships to body size/weight were often unknown and possibly differed between species. Because of differences in the scaling properties of alternative intervening variables across the species investigated, conflicting conclusions may be drawn if different variables are chosen as substitutes for overall size. This is illustrated with two examples. In this study, series of skeletons with associated body weights of Gorilla, Pan, Pongo, and Homo were investigated. Both ontogenetic and static adult allometric relationships between several widely used reference variables and body weight were determined. Neither these variables nor additional estimators investigated in this study displayed allometric exponents and coefficients similar enough across species to justify direct interspecific comparison. To generate an alternative size estimator for both ontogenetic and static interspecific investigations, equations for combined sexes were derived to predict body weight from various long bone dimensions for individual hominoid species. From a total of 25 predictors, 12 prediction equations per species (six for nonadults and six for adults) were selected according to their relative suitability for reliable prediction of body weight. It is shown that the derived reference variable “predicted body weight” avoids problems of intervening variables, is valid for any interspecific ontogenetic and static allometric comparison, and displays less fluctuation in comparison to actual body weight. © 1992 Wiley‐Liss, Inc.
Three‐dimensional finite element stress analysis of the dentate human mandible
Authors: Korioth Tom W. P. , Romilly Douglas P. , Hannam Alan G. 
Published: February 2006

AbstractThe biomechanical events which accompany functional loading of the human mandible are not fully understood. The techniques normally used to record them are highly invasive. Computer modelling offers a promising alternative approach in this regard, with the additional ability to predict regional stresses and strains in inaccessible locations. In this study, we built two three‐dimensional finite element (FE) models of a human mandible reconstructed from tomographs of a dry dentate jaw. The first model was used for a complete mechanical characterization of physical events. It also provided comparative data for the second model, which had an increased vertical corpus depth. In both cases, boundary conditions included rigid restraints at the first right molar and endosteal cortical surfaces of the articular eminences of temporal bones. Groups of parallel multiple vectors simulated individual masticatory muscle loads. The models were solved for displacements, stresses, strains, and forces. The simulated muscle loads in the first model deformed the mandible helically upward and toward its right (working) side. The highest principal stresses occurred at the bite point, anterior aspects of the coronoid processes, symphyseal region, and right and left sides of the mandibular corpus. In general, the observed principal stresses and strains were highest on the periosteal cortical surface and alveolar bone. At the symphyseal region, maximum principal stresses and strains were highest on the lower lingual mandibular aspect, whereas minimum principal stresses and strains were highest on its upper labial side. Subcondylar principal strains and condylar forces were higher on the left (balancing or nonbiting) side than on the right mandibular side, with condylar forces more concentrated on the anteromedial aspect of the working‐side condyle and on the central and lateral aspects of the left. When compared with in vivo strain data from macaques during comparable biting events, the predictive strain values from the first model were qualitatively similar. In the second model, the reduced tensile stress on the working‐side, and decreased shear stress bilaterally, confirmed that lower stresses occurred on the lower mandibular border with increased jaw depth. Our results suggested that although the mandible behaved in a beam‐like manner, its corpus acted more like a combination of open and closed cross sections due to the presence of tooth sockets, at least for the task modelled. Although restricted by an oversimplified representation of mandibular structure, limited data which described the behaviour of its various material components, and approximation of the behaviour within and between groups of jaw muscles, our FE‐based predictions were consistent with current notions of mandibular mechanics derived from experimental recordings in man and nonhuman primates. © 1992 Wiley‐Liss, Inc.
Diet and dental caries among later stone age inhabitants of the Cape Province, South Africa
Authors: Sealy J. C. , Patrick M. K. , Morris A. G. , Alder D. 
Published: February 2006

AbstractStable carbon isotope measurements and incidences of dental caries are presented for three groups of prehistoric human skeletons from different regions of the Cape Province, South Africa. The isotopic analyses of bone collagen demonstrate the importance of marine foods in the diet and vary through time, across space, and according to sex. The incidence of dental caries ranges from 0% among heavily marine‐dependent individuals from the south‐western Cape coast, to 17.7% among skeletons from an archaeological site on the south coast. The extremely high incidence of caries in a hunter‐gatherer population may be related to lack of fluoride in the water. © 1992 Wiley‐Liss, Inc.
Homology and evolution of the orbitotemporal venous sinuses of humans
Authors: Diamond Michael K. 
Published: February 2006

AbstractThe orbitotemporal venous sinuses accompany the intracranial branches of the stapedial artery. These sinuses are large in primitive primates and drain the extensive territories supplied by the stapedial artery as well as the brain. The orbit is drained by a wide cranio‐orbital sinus which empties into the postglenoid emissary vein. Also emptying into the postglenoid vein is the petrosquamous sinus. The latter diverts cerebral blood from the transverse sinus and also drains the temporalis muscle. Emptying into both the cranio‐orbital and petrosquamous sinuses are meningeal tributaries, which drain the cranial side wall and the dura mater. The relatively small sinus communicans runs in the angle between the petrosal bone and the cranial side wall. It commences at the postglenoid vein and connects the distal end of the petrosquamous sinus to the pterygoid venous plexus. In humans, the orbitotemporal sinus system is greatly modified. Its remnants persist for the most part as “middle meningeal veins.” The system no longer drains the orbit, the temporal fossa, or the brain. The petrosquamous sinus becomes attenuated or obliterated along part or all of its length. The postglenoid vein vanishes. The cranio‐orbital sinus is reduced in diameter and its connection to the orbit is feeble or absent. During development, the posterior end of the cranio‐orbital sinus migrates inferiorly along the sinus communicans. In most individuals, this migration ceases at the foramen spinosum, site of the emissary vein of the sinus communicans. Meningeal tributaries are relatively large in humans, and drain principally into the cranio‐orbital sinus or sphenoparietal sinus. The sphenoparietal sinus is an evolutionary novelty restricted to hominoids and is frequently developed in onlyHomoandPongo. © Wiley‐Liss, Inc.
Molecular and classical cytogenetic analyses demonstrate an apomorphic reciprocal chromosomal translocation in Gorilla gorilla
Authors: Stanyon R. , Wienberg J. , Romagno D. , Bigoni F. , Jauch A. , Cremer T. 
Published: February 2006

AbstractThe existence of an apomorphic reciprocal chromosomal translocation in the gorilla lineage has been asserted or denied by various cytogeneticists. We employed a new molecular cytogenetic strategy (chromosomal in situ suppression hybridization) combined with high‐resolution banding, replication sequence analysis, and fluorochrome staining to demonstrate that a reciprocal translocation between ancestral chromosomes homologous to human chromosome 5 and 17 has indeed occurred. © 1992 Wiley‐Liss, Inc.
Nutritional status of adults in rural Mali
Authors: Dettwyler Katherine A. 
Published: February 2006

AbstractAn anthropometric assessment was conducted of 441 adults from six rural villages in southern Mali. As is typical for human populations, females are shorter and lighter than males. Both females (N = 320) and males (N = 121) are shorter and lighter than their U.S. counterparts. Mean weight in the sample is 53.4 ± 8.5 kilos for females and 58.8 ± 6.5 kilos for males. Mean height is 160.4 ± 5.7 cm for females and 171.3 ± 6.6 cm for males. The data for height in males are very similar to those reported from other surveys in Mali, and show no evidence for a positive secular trend in height. Mean body mass index (BMI) is 20.8 for females and 20.0 for males. These are lower than U.S. averages, but well above suggested cutoff points for malnutrition in adults. Average arm circumference is 26.5 cm for females and 26.4 cm for males. Females have relatively large arm circumferences due, in part, to the heavy manual labor they perform. Average head circumference is 53.0 cm for females and 54.8 cm for males. For both sexes, these values are more than 1 standard deviation (SD) below the U.S. means. Adult values for anthropometric measurements reflect childhood stresses of malnutrition and disease, and a lifetime of accommodation to a high‐carbohydrate, low‐protein diet, and hard physical labor. Females are significantly closer to the U.S. standards than males for weight, height, BMI, and arm circumference; these findings support the idea that females are buffered from environmental stresses relative to males. In addition, females exhibit significantly more variability than males for weight, arm circumference, and head circumference, but not for height, suggesting that variability in adult height does not reflect the presence or absence of female buffering or the level of environmental adversity. © 1992 Wiley‐Liss, Inc.
Erosive arthritis and spondyloarthropathy in old world primates
Authors: Rothschild Bruce M. , Woods Robert J. 
Published: February 2006

AbstractPresence of spine and sacroiliac involvement and the nature and distribution of the erosive lesions allow definitive diagnosis of Spondyloarthropathy. Thus, Spondyloarthropathy was identified in Theropithecus, Papio, Cercopithecus, Macaca, Colobus, Presbytis, and Hylobates. Only monarticular erosive disease was present in prosimians, precluding a diagnosis of Spondyloarthropathy for that group. The distribution of erosive disease and axial joint involvement in 1,349 non‐prosimian Old World primates is quite characteristic of that noted in human psoriatic arthritis. While Reiter's syndrome must also be considered, the histologic appearance of skin lesions in Macaca is characteristic of psoriasis.Evidence of Spondyloarthropathy abounds in the literature of primate skeletal disease. Environmentally based contagions may be important in the pathophysiology of spondyloarthropathy. The wide geographic distribution of the phenomena in monkeys suggests a “panendemic,” with limited individual susceptibility (compared to that noted in gorillas and chimpanzees). Identical occurrence of erosive arthritis/spondyloarthropathy in free‐ranging and artificially restrained animals suggests that spondyloarthropathy can validly be studied in artificially restrained populations. This perspective should allow application of human therapeutic approaches to and perhaps improve the quality of life for artificially restrained, afflicted individuals. © 1992 Wiley‐Liss, Inc.
Dietary and dental adaptations in the Pitheciinae
Authors: Kinzey Warren G. 
Published: February 2006

AbstractSince Mivart (1865), Cacajao, Chiropotes, and Pithecia have been grouped into a single taxon, which he called the subfamily Pitheciinae but which I, following Rosenberger (this issue), refer to as the living members of the tribe Pitheciini. While few today doubt the association of these three living genera, not all would place them together with Aotus and Callicebus in the subfamily Pitheciinae. This is an attempt to sort out the behavioral and morphological features of feeding and dental morphology in these taxa. Extant members of the tribe Pitheciini are adapted for sclerocarpic foraging, morphological evidence for which is found in the fossils of Soriacebus and Cebupithecia. Sclerocarpic foraging in living pitheciins is a two‐stage process of seed predation involving 1) specialized features of the anterior dentition that allow removal of a hard pericarp that protects a seed or seeds, followed by 2) mastication by the posterior dentition having low cusp relief to triturate nutritious seeds of a relatively soft and uniformly pliable consistency. The dentitons of fossil pitheciins, Soriacebus and Cebupithecia, demonstrate that the hypertrophy of lower incisors plus the robustness and flaring of the canine precede development of low cusp relief on molars and premolars in the evolution of morphological features associated with sclerocarpic foraging. Features of sclerocarpic foraging are found less uniformly in the other two pitheciines, Callicebus and Aotus. © 1992 Wiley‐Less, Inc.
Atelinae adaptations: Behavioral strategies and ecological constraints
Authors: Strier Karen B. 
Published: February 2006

AbstractComparisons between the four genera that make up the Atelinae reveal two distinct behavioral patterns, one in which energy expenditure is minimized (Alouatta) and one in which energy intake is maximized (Lagothrix, Ateles, and Brachyteles). Among the atelins, Lagothrix and Ateles devote over 75% of their annual feeding time to fruit, while Brachyteles devotes between 50% and 67% of their feeding time to leaves. Pronounced seasonality in the Atlantic coastal forest inhabited by Brachyteles may be responsible for its more folivorous diet. Alouatta falls in the body size range of Lagothrix and is much smaller than Ateles and Brachyteles. Nonetheless, Alouatta is more folivorous than sympatric atelins. The atelins also share a rapid, suspensory mode of locomotion that appears to enable them to minimize travel time between widely dispersed fruit sources. Alouatta, by contrast, employs a slower, but more energetically efficient, quadrupedal locomotion. Ranging patterns among the Atelinae are consistent with both diet and locomotor abilities: Atelins travel daily distances up to 5,000 m; Alouatta ranges are much shorter. Further distinctions are evident in Atelinae grouping patterns. Alouatta remains in small cohesive groups that occupy home ranges less than 60 ha in size. Both Lagothrix and Ateles have large groups that fission to reduce the costs of intragroup feeding competition when preferred fruits occur in small patches within much larger community ranges. While greater reliance on low‐energy foods such as leaves may release Brachyteles from similar competitive constraints, their tendency toward fluid grouping associations is consistent with the pursuit of a frugivorous diet. © 1992 Wiley‐Liss, Inc.
Evolution of feeding niches in new world monkeys
Authors: Rosenberger Alfred L. 
Published: February 2006

AbstractThe adaptive radiation of modern New World monkeys unfolded as the major lineages diversified within different dietary‐adaptive zones predicated upon a fundamentally frugivorous habit. The broad outlines of this pattern can be seen in the fossil record, beginning in the early Miocene. Cebids are obligate frugivorous predators. The smallest forms (Cebuella,Callithrix) are specialized exudativores, and the largest (cebines) are seasonally flexible omnivores, feeding particularly on insects (Saimiri) or “hard” foods, such as pith and palm nuts (Cebus), when resources are scarce. The smaller‐bodied atelids (Callicebus,Aotus) may use insects or leaves opportunistically, but pitheciins (saki‐uakaris) specialize on seeds as their major protein source.The larger atelines (Alouatta,Brachyteles) depend on leaves or on ripe fruit (Ateles). Locomotion, body size, and dietary adaptations are linked: claws and small body size opened the canopy‐subcanopy niche to callitrichines; climbing and hanging, the fine‐branch setting to the atelines; large size and strength, semiprehensile tails, and grasping thumbs, the extractive insectivory ofCebus; deliberate quadrupedalism, the energy‐saving transport of folivorousAlouatta. Body size increases and decreases occurred often and in parallel within guilds and lineages. Conventional dietary categories, particularly frugivory, are inadequate for organizing the behavioral and anatomical evidence pertinent to evolutionary adaptation. Related models of morphological evolution based on feeding frequencies tend to obfuscate the selective importance of “critical functions,” responses to the biomechanically challenging components of diet that may be determined by a numerically small, or seasonal, dietary fraction. For fossils, body size is an unreliable indicator of diet in the absence of detailed morphological information. More attention needs to be given to developing techniques for identifying and quantifying mechanically significant aspects of dental form, the physical properties of primate foods, their mode of access, and the cycles of availability and nutritional value. © 1992 Wiley‐Liss, Inc.