1,227 research outputs found
Relative fibular strength and locomotor behavior in KNM-WT 15000 and OH 35
No full textRelative fibular/tibial strength has been demonstrated to vary with locomotor behavior among anthropoid
primates. In this study fibular/tibial strength was determined in KNM-WT 15000, a juvenile Homo
erectus individual (1.5 Ma), and in OH 35, a Homo habilis (or possibly Paranthropus boisei) individual
(1.8 Ma), and compared to that of adult modern humans (n 1⁄4 79), chimpanzees (n 1⁄4 16), gorillas (n 1⁄4 16)
and orangutans (n 1⁄4 11). Ontogenetic changes in fibular/tibial strength were also analyzed due to KNMWT
15000's juvenile status. Cross-sectional properties at midshaft were derived from multi-plane
radiography and external contours, or CT scanning. Comparisons of log-transformed fibular/tibial polar
second moment of area and anteroposterior (A-P) and mediolateral (M-L) second moments of area were
carried out between extant species. Fossil deviations from each extant taxon's mean proportion were
calculated in standard deviation (SD) units for that taxon. Great apes differ significantly from modern
humans, with relatively stronger fibulae, particularly in the M-L plane. KNM-WT 15000 is more than 2 SD
from all great apes (3 SD in the M-L plane) and within 1 SD of modern humans for almost all variables.
This is not a result of its age, as fibular/tibial strength slightly decreases with age (i.e., becomes less like
that of great apes) in humans. OH 35 falls within 1 SD of chimpanzees and orangutans for the majority of
cross-sectional proportions, but more than 1 SD from humans. KNM-WT 15000 is demonstrated to be
fully modern, complimenting other indications of complete terrestrial bipedality and possibly showing
adaptations for endurance running. OH 35 has some human-like features; however, the relative strength
of the two bones aligns the specimen with great apes, consistent with a significant degree of arboreality,
in particular, vertical climbing
Skeletal Variation and Adaptation in Europeans: Upper Paleolithic to the Twentieth Century
No full textThis file contains bone structural data and associated contextual information for 2177 European skeletons dating from about 32,000 years before present to the late 20th century. They were collected as part of a project funded primarily by the US National Science Foundation and carried out between 2007 and 2015. The primary publication associated with this file is: Ruff, C. B. (ed.) (2018) Skeletal variation and adaptation in Europeans: Upper Paleolithic to the Twentieth Century. Hoboken: Wiley Blackwell. Please see the attached Notes file for more information on collaborators and contacts, as well as descriptions of data variables and other notes
Longitudinal performance on the Ruff Figural Fluency Test per age group.
No full text<p>Abbreviations: RFFT, Ruff Figural Fluency Test; SD, standard deviation; IQR, interquartile range.</p><p><sup>a</sup> Trends across consecutive measurements and age groups were analyzed by ANOVA for the number of unique designs and by Kruskal-Wallis H test for the number of perseverative errors.</p><p><sup>b</sup><i>p</i> value for trend across age groups is <0.001.</p><p><sup>c</sup> Trend across age groups is not statistically significant.</p><p>Longitudinal performance on the Ruff Figural Fluency Test per age group.</p
CCK and the immune system: receptor mediated chemotaxis of rat and human macrophages
No full textThe ability of the peptide cholecystokinin (CCK) to induce monocyte chemotaxis was tested both in vivo and in vitro. In the in vitro assay, the activity of different forms of CCK on human monocytes was studied demonstrating the importance of sulfation on tyrosine for the chemotactic activity. CCK receptor antagonists benzotript and CR-1369 are able to block CCK 8 sulfated chemotaxis, thus suggesting the presence of CCK receptors on human monocytes. In both acute and chronic experiments, the peptide specifically increases the number of peritoneal macrophages, when injected into rat peritoneal cavity. These data suggest that immune system cell migration from one body compartment to another can be produced by a neuropeptide receptor-mediated process
Demonstration of receptor-mediated chemotaxis by human spermatozoa. A novel quantitative bioassay.
No full textA novel in vitro technique is described for measuring the chemotactic activity of soluble substances for human spermatozoa. This new bioassay has demonstrated that the synthetic chemotactic peptide N-formyl-Met-Leu-Phe elicits a potent, specific (i.e., receptor-mediated) chemotactic effect on human spermatozoa with an EC50 of 3.2 X 10(-10) M. Quantitative chemotactic studies on human spermatozoa with nine N-formylated-peptide analogs have shown a rank order of peptide potency indistinguishable (p less than 0.001) from that obtained in binding and chemotactic studies with rabbit neutrophils. The competitive antagonist Boc (t-butoxycarbonyl)-Phe-Leu-Phe-Leu-Phe, 10(-6) M, completely inhibited the chemotaxis elicited by f-Met-Leu-Phe, 10(-9) M, and was able to shift by one order of magnitude the molar concentration required by f-Met-Leu-Phe-Phe and f-Met-Leu-Phe to elicit the maximal response. The ability of N-formylated peptides to function as sperm chemoattractants reveals a high degree of correlation with binding, chemotaxis, and lysosomal enzyme release previously employed to define the neutrophil chemotactic receptor. This first unequivocal demonstration of substances having a receptor-mediated chemotactic effect for human male gametes suggests that human spermatozoa may indeed have the ability to respond chemotactically to appropriate environmental signals
Longitudinal performance on the Ruff Figural Fluency Test per educational level.
No full text<p>Abbreviations: RFFT, Ruff Figural Fluency Test; SD, standard deviation; IQR, interquartile range.</p><p><sup>a</sup> Trends across consecutive measurements and educational levels were analyzed by ANOVA for the number of unique designs and by Kruskal-Wallis H test for the number of perseverative errors.</p><p><sup>b</sup><i>p</i> value for trend across educational levels is <0.001.</p><p><sup>c</sup> Trend across educational levels is not statistically significant.</p><p><sup>d</sup><i>p</i> value for trend across educational levels is <0.01.</p><p>Longitudinal performance on the Ruff Figural Fluency Test per educational level.</p
Linear multilevel regression analysis of performance on the Ruff Figural Fluency Test: unique designs.
No full text<p>Abbreviations: B, unstandardized B-coefficient; CI, confidence interval; Ref, reference category.</p><p><sup>a</sup> Consecutive measurement number.</p><p><sup>b</sup> For model 1: −2*log likelihood 65821.57.</p><p><sup>c</sup> For model 2: −2*log likelihood 65241.34.</p><p><sup>d</sup> For model 3: −2*log likelihood 65088.13.</p><p>Linear multilevel regression analysis of performance on the Ruff Figural Fluency Test: unique designs.</p
Linear multilevel regression analysis of performance on the Ruff Figural Fluency Test: perseverative errors.
No full text<p>Abbreviations: B, unstandardized B-coefficient; CI, confidence interval; Ref, reference category.</p><p><sup>a</sup> Consecutive measurement number.</p><p><sup>b</sup> For model 1: −2*log likelihood 60760.87.</p><p><sup>c</sup> For model 2: −2*log likelihood 60760.52.</p><p><sup>d</sup> For model 3: −2*log likelihood 60751.38.</p><p>Linear multilevel regression analysis of performance on the Ruff Figural Fluency Test: perseverative errors.</p
Synthesis And Characterization Of Low Bandgap Nanocrystalline T-Zirconia [TA418.9.N35 N692 2007 f rb].
No full textSerbuk nanohablur t-ZrO2 disintesis melalui kaedah kimia untuk mencari kemungkinan jika dop elektronik akan meningkatkan konduktiviti elektronik oksida. Y3+
ditambah sebagai penstabil untuk mengekalkan fasa t-ZrO2 manakala Nb5+ dimasukkan untuk dop elektronik.
Nanocrystal t-ZrO2 powders were synthesized through a chemical route to seek a possibility if electronic doping would improve the electronics conductivity of the oxide.
Y3+ was added as a stabilizer to retain tetragonal phase ZrO2 whereas Nb5+ was added for electronics doping
Dataset on the bearing capacity of curved profiles obtained by roll forming process
No full textThe paper shows experimental data concerning the bearing capacity of curved profile sheets achieved by roll forming process.
Two different restraint configurations were considered, respectively named A and B and representing the only bending and the axial-bending conditions. Two different experimental setup, i.e. single span with and without horizontal restraints were adopted. Trapezoidal and sinusoidal steel sheets with variable thickness and curvature radius were tested. Setup configurations, collapse
mechanisms and load-deflection diagrams are presented
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