4,923 research outputs found
Separating sexual dimorphism from other morphological variation in a specimen complex of fossil marine reptiles (Reptilia, Ichthyosauriformes, Chaohusaurus).
The Early Triassic Chaohu Fauna from Anhui Province, China, contains the oldest record of Mesozoic marine reptiles, such as Cartorhynchus and Sclerocormus. Most specimens from the fauna belong to the ichthyosauriform Chaohusaurus, more specifically resembling C. chaoxianensis. However, a wide range of morphological variation exists within about 40 skeletons that have been prepared, likely reflecting mixed signals from both sexual and taxonomic differences. We test whether the sexual and taxonomic signals are separable based on quantification, aided by the knowledge of sexual dimorphism in extant marine tetrapods. There are two different suites of dimorphism that divide the specimens differently from each other yet consistently within each suite, resulting in four morphotypes in combination, likely representing two sexes of two taxa. Presumed males have larger organ of prehension sensu Darwin, specifically limbs in the present case, for a given body length. This sexing criterion is supported by the only specimen of a gravid female, which belongs to the morphotype with short limbs. Males also have larger skulls for the trunk length compared to females. This study demonstrates that sexual and taxonomic signals are separable in fossil reptiles, with a sufficient sample size and careful analyses
Finding emergence in data by maximizing effective information
Quantifying emergence and modeling emergent dynamics in a data-driven manner
for complex dynamical systems is challenging due to the lack of direct
observations at the micro-level. Thus, it's crucial to develop a framework to
identify emergent phenomena and capture emergent dynamics at the macro-level
using available data. Inspired by the theory of causal emergence (CE), this
paper introduces a machine learning framework to learn macro-dynamics in an
emergent latent space and quantify the degree of CE. The framework maximizes
effective information, resulting in a macro-dynamics model with enhanced causal
effects. Experimental results on simulated and real data demonstrate the
effectiveness of the proposed framework. It quantifies degrees of CE
effectively under various conditions and reveals distinct influences of
different noise types. It can learn a one-dimensional coarse-grained
macro-state from fMRI data, to represent complex neural activities during movie
clip viewing. Furthermore, improved generalization to different test
environments is observed across all simulation data
Lentivirus-mediated RNA interference of vascular endothelial growth factor in monkey eyes with iris neovascularization
Purpose: To explore the in vivo anti-angiogenesis effects resulting from lentivirus-mediated RNAi of vascular endothelial growth factor (VEGF) in monkeys with iris neovascularization (INV). Methods: Five specific recombinant lentiviral vectors for RNA interference, targeting Macaca mulatta VEGFA, were designed and the one with best knock down efficacy (LV-GFP-VEGFi1) in H1299 cells and RF/6A cells was selected by real-time PCR for in vivo use. A laser-induced retinal vein occlusion model was established in one eye of seven cynomolgus monkeys. In monkeys number1, 3, and 5 (Group 1), the virus (1x10(8) particles) was intravitreally injected into the preretinal space of the animal's eye immediately after laser coagulation; and in monkeys number 2, 4, and 6 (Group 2), the virus (1x10(8) particles) was injected at 10 days after laser coagulation. In monkey number 7, a blank control injection was performed. In monkeys number 1 and 2, virus without RNAi sequence was used; in monkeys number 3 and 4, virus with nonspecific RNAi sequence was used; and in monkeys 5 and 6, LV-GFP-VEGFi1 was used. Results: In monkey number 5, at 23 days after laser treatment, no obvious INV was observed, while fluorescein angiography of the iris revealed high fluorescence at the margin of pupil and point posterior synechiae. At 50 days after laser treatment, only a slight ectropion uvea was found. However, in the other eyes, obvious INV or hyphema was observed. The densities of new iridic vessels all significantly varied: between monkey number 5 and number 3 (36.01 +/- 4.49/mm(2) versus 48.68 +/- 9.30/mm(2), p=0.025), between monkey number 3 and monkey number 7 (48.68 +/- 9.30/mm(2) versus 74.38 +/- 9.23/mm(2), p=0.002), and between monkey number 5 and number 7 (36.01 +/- 4.49/mm(2) versus 74.38 +/- 9.23/mm(2), p<0.001). Conclusions: Lentivirus-mediated RNAi of VEGF may be a new strategy to treat iris neovascularization, while further studies are needed to investigate the long-term effect.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000281341400003&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Biochemistry & Molecular BiologyOphthalmologySCI(E)PubMed7ARTICLE187-891743-17531
Multi-Scale Simulation of Complex Systems: A Perspective of Integrating Knowledge and Data
Complex system simulation has been playing an irreplaceable role in
understanding, predicting, and controlling diverse complex systems. In the past
few decades, the multi-scale simulation technique has drawn increasing
attention for its remarkable ability to overcome the challenges of complex
system simulation with unknown mechanisms and expensive computational costs. In
this survey, we will systematically review the literature on multi-scale
simulation of complex systems from the perspective of knowledge and data.
Firstly, we will present background knowledge about simulating complex system
simulation and the scales in complex systems. Then, we divide the main
objectives of multi-scale modeling and simulation into five categories by
considering scenarios with clear scale and scenarios with unclear scale,
respectively. After summarizing the general methods for multi-scale simulation
based on the clues of knowledge and data, we introduce the adopted methods to
achieve different objectives. Finally, we introduce the applications of
multi-scale simulation in typical matter systems and social systems
Testing and Data Reduction of the Chinese Small Telescope Array (CSTAR) for Dome A, Antarctica
The Chinese Small Telescope ARray (hereinafter CSTAR) is the first Chinese
astronomical instrument on the Antarctic ice cap. The low temperature and low
pressure testing of the data acquisition system was carried out in a laboratory
refrigerator and on the 4500m Pamirs high plateau, respectively. The results
from the final four nights of test observations demonstrated that CSTAR was
ready for operation at Dome A, Antarctica. In this paper we present a
description of CSTAR and the performance derived from the test observations.Comment: Accepted Research in Astronomy and Astrophysics (RAA) 1 Latex file
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Induction of apoptosis by the retinoid inducible growth regulator RIG1 depends on the NC motif in HtTA cervical cancer cells
<p>Abstract</p> <p>Background</p> <p>Retinoid-inducible gene 1 (RIG1), also known as tazarotene-induced gene 3 or retinoic-acid receptor responder 3, is a growth regulator, which induces apoptosis and differentiation. RIG1 is classified into the NC protein family. This study investigated functional domains and critical amino acids associated with RIG1-mediated cell death and apoptosis.</p> <p>Results</p> <p>Using enhanced green fluorescence protein (EGFP)-tagged RIG1 variants, RIG1 proteins with deletion at the NC domain significantly decreased cell death induced by RIG1, and fusion variants containing only the NC domain significantly induced apoptosis of HtTA cervical cancer cells. The EGFP-RIG1-induced apoptosis was significantly decreased in cells expressing N<sup>112</sup>C<sup>113 </sup>motif double- (NC→FG) or triple- (NCR→FGE) mutated RIG1 variants. Using dodecapeptides, nuclear localization and profound cell death was observed in HtTA cells expressing wild type RIG1<sub>111–123 </sub>or Leu<sup>121</sup>-mutated RIG1<sub>111–123</sub>:L→ C peptide, but peptides double- or triple-mutated at the NC motif alone, RIG1<sub>111–123</sub>:NC→FG or RIG1<sub>111–123</sub>:NCR→FGE, were cytoplasmically localized and did not induce apoptosis. The RIG1<sub>111–123 </sub>also induced apoptosis of A2058 melanoma cells but not normal human fibroblasts.</p> <p>Conclusion</p> <p>The NC domain, especially the NC motif, plays the major role in RIG1-mediated pro-apoptotic activity. The RIG1<sub>111–123 </sub>dodecapeptide exhibited strong pro-apoptotic activity and has potential as an anticancer drug.</p
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