1,371 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
Profound anti-HIV-1 activity of DAPTA in monocytes/macrophages and inhibition of CCR5-mediated apoptosis in neuronal cells
No full textMonocytes/macrophages (M/M) are strategic reservoirs of HIV-1, spreading the virus to other cells and inducing apoptosis in T-lymphocytes, astrocytes and neurons. M/M are commonly infected by R5 HIV-1 strains, which use the chemokine receptor CCR5. D-Ala-peptide T-amide (DAPTA), or Peptide T, named for its high threonine content (ASTTTNYT), is a synthetic peptide comprised of eight amino acids (185-192) of the gp120 V2 region and functions as a viral entry inhibitor by targeting selectively CCR5. The anti-HIV-1 activity of DAPTA was evaluated in M/M infected with R5 HIV-1 strains. DAPTA at 10-9M inhibited HIV-1 replication in M/M by >90%. PCR analysis of viral cDNA in M/M showed that DAPTA blocks HIV entry and in this way prevents HIV-1 infection. Moreover, DAPTA acts as a strong inhibitor and was more active than the non-peptidic CCR5 antagonist TAK-779 in inhibiting apoptosis (mediated by R5 HIV-1 strains produced and released by infected M/M) on a neuroblastoma cell line. Our results suggest that antiviral compounds which interfere with receptor mechanisms such as CCR5 could be important, either alone or in combination with other antiretroviral treatments, in preventing HIV infection in the central nervous system and the consequential neuronal damage that leads to neuronal AIDS. ©2007 International Medical Press
Profound anti-HIV-1 activity of DAPTA in monocytes/macrophages and inhibition of CCR5-mediated apoptosis in neuronal cells
No full textANÁLISIS PSICOMÉTRICO DEL "TEST DE FLUIDEZ DE DISEÑOS DE RUFF" EN POBLACIÓN UNIVERSITARIA DE BOGOTÁ
No full textExecutive function is the construct that comprises the spectrum of cognitive abilities that enable the individual to anticipate, initiate, provide feedback to the behavior and have cognitive flexibility. One of the useful tests to assess this function is the Ruff Figural Fluency Test which measures visuomotor programming and is associated with right frontal activity. In Colombia this test has not been validated with adult population, and considering the usefulness of this instrument for assessing people with neurological injury, the need to carry out a study to analyze the feasibility of using this test both in research and clinical practice was raised. The overall objective was to conduct a psychometric analysis of the Ruff Test with university population in Bogotá. The study was descriptive, of instrumental type. Participants were 492 university students, men and women, aged between 18 and 28 years, enrolled in seven universities of the city of Bogotá. The internal consistency analysis yielded a Cronbach's alpha of 0.876. In order to establish convergent validity, the WAIS cubes subtest was used, and a correlation of 0.24 was found, with p = 0.001. Factor analysis yielded four factors, three of which coincide with the studies conducted by the author of the test. The fourth factor found was related with following directions. Sex differences were found in the unique designs factor, where women obtained a higher average than men
Sperm competition and sperm length in shorebirds
No full textWe investigated how sperm morphology varies across 16 species of shorebirds in the Scolopacidae, Charadriidae, and Jacanidae. Sperm were significantly longer in nonmonogamous than in socially monogamous species. Nonmonogamous species also had significantly longer midpieces and tails than monogamous species. As the midpiece houses the mitochondria for powering the tail, this suggests that sperm competition may select for greater investment in mobility. After controlling for phylogeny and male body mass, sperm tail length was correlated positively to relative testis size. There was no evidence that variation in sperm morphology was related to either male body mass (through allometry) or egg size (via linkage disequilibrium). Instead, our results suggest that sperm size in shorebirds increases with the intensity of sperm competition.</p
Supplemental material for Efficacy of galcanezumab in patients with chronic migraine and a history of preventive treatment failure
No full textSupplemental Material for Efficacy of galcanezumab in patients with chronic migraine and a history of preventive treatment failure by Dustin D Ruff, Janet H Ford, Antje Tockhorn-Heidenreich, Matthew Sexson, Sriram Govindan, Eric M Pearlman, Shuu-Jiun Wang, Arif Khan and Sheena K Aurora in Cephalalgia</p
Spring migration of Ruffs Philomachus pugnax in Fryslân: estimates of staging duration using resighting data
No full textSeasonal bird migration involves long flights, but most time is actually spent at intermediate staging areas. The duration of stay at these sites can be evaluated with mark–recapture methods that employ day-to-day local encounters of individually marked birds. Estimates of staging duration are based on two probabilities: the immigration probability, the complement of a bird’s seniority to an area, and the emigration probability, the complement of the staying probability. Estimating total staging duration from seniority and staying probabilities requires validation for resighting data and here we compare three data categories of Ruffs Philomachus pugnax passing through The Netherlands during northward migration: (1) newly colour-ringed, (2) previously colour-ringed and (3) radio-tagged Ruffs (recorded by automated receiving stations). Between 2004 and 2008, 4363 resighting histories and 95 telemetry recording histories were collected. As sample sizes for females were low, only data for males were analysed. Possible catching effects affecting estimates of staging duration were explored. Staying probability was estimated for all data. Seniority however, could not be estimated for newly marked Ruffs; the assumption of equal ‘capture’ probability for reverse-time models applied to estimate seniority is violated for seasonal resighting histories starting with a catching event. Therefore, estimates of total staging duration were based on resightings of previously colour-marked birds only. For radio-tagged birds a minimal staging duration (time between tagging and last recording) was calculated. Modelling indicated that newly colour-ringed birds had a higher staying probability than previously colour-ringed birds, but the difference translated to a prolonged staging duration in newly ringed birds of only 0.4–0.5 d, suggesting a very small catching effect. The minimal staging duration of radio-tagged birds validated estimates of staging duration for colour-ringed birds in 2007 but not in 2005. In 2005 a low resighting probability resulted in underestimates of staging duration. We conclude that (1) estimates of staying probability can be affected by catching although effects on staging duration might be small, and that (2) low resighting probabilities can lead to underestimates in staging duration. In our study previously ringed Ruffs resighted in 2006–08 yielded reliable estimates of staging duration as data had sufficiently high resighting probabilities. Average staging durations varied between 19 d in 2008 and 23 d in 2006.
Studying the Role of Human Parietal Cortex in Visuospatial Attention with Concurrent TMS-fMRI
No full textCombining transcranial magnetic stimulation (TMS) with concurrent functional magnetic resonance imaging (fMRI) allows study of how local brain stimulation may causally affect activity in remote brain regions. Here, we applied bursts of high- or low-intensity TMS over right posterior parietal cortex, during a task requiring sustained covert visuospatial attention to either the left or right hemifield, or in a neutral control condition, while recording blood oxygenation-level-dependent signal with a posterior MR surface coil. As expected, the active attention conditions activated components of the well-described "attention network," as compared with the neutral baseline. Also as expected, when comparing left minus right attention, or vice versa, contralateral occipital visual cortex was activated. The critical new finding was that the impact of high- minus low-intensity parietal TMS upon these visual regions depended on the currently attended side. High- minus low-intensity parietal TMS increased the difference between contralateral versus ipsilateral attention in right extrastriate visual cortex. A related albeit less pronounced pattern was found for left extrastriate visual cortex. Our results confirm that right human parietal cortex can exert attention-dependent influences on occipital visual cortex and provide a proof of concept for the use of concurrent TMS-fMRI in studying how remote influences can vary in a purely top-down manner with attentional demands
Magnetic excitations in double perovskite iridates LaIrO ( = Co, Ni, and Zn) mediated by 3-5 hybridization
No full textBy performing resonant inelastic x-ray scattering (RIXS) measurements at the
Ir edge, we have investigated the low-energy
elementary excitations in a series of double perovskite iridate single
crystals, LaIrO ( = Co, Ni, and Zn). Almost
dispersionless magnetic excitations at 42(6) meV and 35(5) meV
have been observed in crystals containing magnetic 3 ions,
LaCoIrO and LaNiIrO, respectively. In contrast, this
low-energy magnetic excitation is absent in LaZnIrO in which the
3 ions are non-magnetic, suggesting the importance of
3-5 hybridization in the magnetic properties of these
double perovskite iridates. The magnetic excitation is suppressed completely
above the magnetic ordering temperature, suggesting the inadequacy of using a
simple spin Hamiltonian to describe magnetism of these materials.Comment: 8 pages, 4 figures, accepted for publication in Physical Review
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