65 research outputs found
Postcranial morphology of the middle Pleistocene humans from Sima de los Huesos, Spain
Current knowledge of the evolution of the postcranial skeleton in the genus Homo is hampered by a geographically and chronologically scattered fossil record. Here we present a complete characterization of the postcranium of the middle Pleistocene paleodeme from the Sima de los Huesos (SH) and its paleobiological implications. The SH hominins show the following: (i) wide bodies, a plesiomorphic char- acter in the genus Homo inherited from their early hominin ancestors; (ii) statures that can be found in modern human middle-latitude pop- ulations that first appeared 1.6–1.5 Mya; and (iii) large femoral heads in some individuals, a trait that first appeared during the middle Pleistocene in Africa and Europe. The intrapopulational size variation in SH shows that the level of dimorphism was similar to modern humans (MH), but the SH hominins were less encephalized than Ne- andertals. SH shares many postcranial anatomical features with Ne- andertals. Although most of these features appear to be either plesiomorphic retentions or are of uncertain phylogenetic polarity, a few represent Neandertal apomorphies. Nevertheless, the full suite of Neandertal-derived features is not yet present in the SH popula- tion. The postcranial evidence is consistent with the hypothesis based on the cranial morphology that the SH hominins are a sister group to the later Neandertals. Comparison of the SH postcranial skeleton to other hominins suggests that the evolution of the postcranium oc- curred in a mosaic mode, both at a general and at a detailed level
Hunting for Primordial Non-Gaussianity in the Cosmic Microwave Background
Since the first limit on the (local) primordial non-Gaussianity parameter,
fNL, was obtained from COBE data in 2002, observations of the CMB have been
playing a central role in constraining the amplitudes of various forms of
non-Gaussianity in primordial fluctuations. The current 68% limit from the
7-year WMAP data is fNL=32+/-21, and the Planck satellite is expected to reduce
the uncertainty by a factor of four in a few years from now. If fNL>>1 is found
by Planck with high statistical significance, all single-field models of
inflation would be ruled out. Moreover, if the Planck satellite finds fNL=30,
then it would be able to test a broad class of multi-field models using the
four-point function (trispectrum) test of tauNL>=(6fNL/5)^2. In this article,
we review the methods (optimal estimator), results (WMAP 7-year), and
challenges (secondary anisotropy, second-order effect, and foreground) of
measuring primordial non-Gaussianity from the CMB data, present a science case
for the trispectrum, and conclude with future prospects.Comment: 33 pages, 4 figures. Invited review, accepted for publication in the
CQG special issue on nonlinear cosmological perturbations. (v2) References
added. More clarifications are added to the second-order effect and the
multi-field consistency relation, tauNL>=(6fNL/5)^2
Treatment-Related Changes in Bone Turnover and Fracture Risk Reduction in Clinical Trials of Anti-Resorptive Drugs: A Meta-Regression
Few pooled analyses of antiresorptive (AR) treatment trials relate short-term changes in bone turnover markers (BTMs) to subsequent fracture reduction. Such information would be useful to assess new ARs or novel dosing regimens. In the Foundation for the National Institutes of Health (FNIH) Bone Quality project, we analyzed individual-level data from 28,000 participants enrolled in 11 bisphosphonate (BP) and three selective estrogen receptor modulator (SERM) placebo-controlled fracture endpoint trials. Using BTM results for two bone formation markers (bone-specific alkaline phosphatase [bone ALP] and pro-collagen I N-propeptide [PINP]) and two bone resorption markers (N-terminal and C-terminal telopeptide of type I collagen) and incident fracture outcome data, we performed a meta-regression relating the mean net effect of treatment on change in bone turnover (active minus placebo % difference after 3 to 12 months) to the log of study-wide fracture risk reduction, and used linear regression to plot the best fitting line. Separate analyses were performed for incident morphometric vertebral, nonvertebral, and hip fractures over 1 to 4 years of follow-up. Change in bone ALP and PINP were available for over 16,000 and 10,000 participants, respectively. For vertebral fracture, the results showed a strong relationship between treatment-related bone ALP or PINP changes and vertebral fracture risk reduction (r2 = 0.82 [p < 0.001] and r2 = 0.75 [p = 0.011], respectively) Relationships were weaker and no longer statistically significant for nonvertebral (r2 = 0.33 [p = 0.053] and r2 = 0.53 [p = 0.065], respectively) and hip fracture (r2 = 0.17 [p = 0.24] and r2 = 0.43 [p = 0.11], respectively) outcomes. Analyses limited to BP trials gave similar results. For all fracture types, relationships were weaker and nonsignificant for bone resorption markers. We conclude that short-term AR treatment-related changes in bone ALP and PINP strongly predict vertebral fracture treatment efficacy, but not nonvertebral or hip fracture treatment efficacy. Change in bone formation markers might be useful to predict the anti-vertebral fracture efficacy of new AR compounds or novel dosing regiments with approved AR drugs
Biology of moderately halophilic aerobic bacteria
The moderately halophilic heterotrophic aerobic bacteria form a diverse group of microorganisms. The property of halophilism is widespread within the bacterial domain. Bacterial halophiles are abundant in environments such as salt lakes, saline soils, and salted food products. Most species keep their intracellular ionic concentrations at low levels while synthesizing or accumulating organic solutes to provide osmotic equilibrium of the cytoplasm with the surrounding medium. Complex mechanisms of adjustment of the intracellular environments and the properties of the cytoplasmic membrane enable rapid adaptation to changes in the salt concentration of the environment. Approaches to the study of genetic processes have recently been developed for several moderate halophiles, opening the way toward an understanding of haloadaptation at the molecular level. The new information obtained is also expected to contribute to the development of novel biotechnological uses for these organisms
Anti-bacterial structure-function relationship studies on melittin
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The effect of the type of preschool curriculum on the fluency, flexibility, originality, and creativity scores as seen through preschoolers\u27 manipulation of simple toys and complex toys
This study aimed to determine the effect of the type of preschool curriculum on the fluency, flexibility, originality, and total creativity scores of preschool children as seen through their manipulation of simple toys and complex toys. It was hypothesized that 1.) If the type of preschool curriculum is open structured, then the fluency, flexibility, originality and total creativity scores of preschool children as manifested through their manipulation of simple toys increase. 2.) If the type of preschool curriculum is open structured, then the fluency, flexibility, originality and total creativity scores of preschool children as manifested through their manipulation of complex toys increase. Additional hypotheses that were formulated were: (a) if the type of preschool curriculum is open structured, then the children\u27s manipulations of the toys become more varied and become higher in number (b) if the type of toy is complex, then creativity in preschool children increases. 33 children (14 from the traditional preschool and 19 from the open preschool) participated in this study. Scores for each component of creativity as well as the overall creativity scores of children in the traditional and open structured preschool were subjected to 8 one-way Analysis of Variance (ANOVA). Results showed that there is a significant difference in the type of preschool curriculum on the scores of each element of the preschoolers\u27 creativity as well as their total creativity scores as manifested through their manipulation of simple toys and complex toys. Only flexibility scores for simple toys were found to be insignificant
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