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801.
Zhi Li Peng Zhou Rafael Della Coletta Tifu Zhang Alex B. Brohammer Christine H. O’Connor Brieanne Vaillancourt Anna Lipzen Chris Daum Kerrie Barry Natalia de Leon Cory D. Hirsch C. Robin Buell Shawn M. Kaeppler Nathan M. Springer Candice N. Hirsch 《The Plant journal : for cell and molecular biology》2021,105(1):93-107
802.
803.
The general Markov model (GMM) of nucleotide substitution does not assume the evolutionary process to be stationary, reversible, or homogeneous. The GMM can be simplified by assuming the evolutionary process to be stationary. A stationary GMM is appropriate for analyses of phylogenetic data sets that are compositionally homogeneous; a data set is considered to be compositionally homogeneous if a statistical test does not detect significant differences in the marginal distributions of the sequences. Though the general time-reversible (GTR) model assumes stationarity, it also assumes reversibility and homogeneity. We propose two new stationary and nonhomogeneous models--one constrains the GMM to be reversible, whereas the other does not. The two models, coupled with the GTR model, comprise a set of nested models that can be used to test the assumptions of reversibility and homogeneity for stationary processes. The two models are extended to incorporate invariable sites and used to analyze a seven-taxon hominoid data set that displays compositional homogeneity. We show that within the class of stationary models, a nonhomogeneous model fits the hominoid data better than the GTR model. We note that if one considers a wider set of models that are not constrained to be stationary, then an even better fit can be obtained for the hominoid data. However, the methods for reducing model complexity from an extremely large set of nonstationary models are yet to be developed. 相似文献
804.
Rocha LA 《Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences》2011,42(3):328-343
This paper begins with a discussion of the scientia sexualis/ars erotica distinction, which Foucault first advances in History of Sexuality Vol. 1, and which has been employed by many scholars to do a variety of analytical work. Though Foucault has expressed his doubts regarding his conceptualization of the differences between Western and Eastern discourses of desire, he never entirely disowns the distinction. In fact, Foucault remains convinced that China must have an ars erotica. I will explore Foucault’s sources of authority. To this end, I introduce the work of famous Dutch sinologist Robert Hans van Gulik, who published the tremendously influential Sexual Life in Ancient China in 1961, and also explore Joseph Needham’s view on Chinese sex. I argue that, Foucault, in his fierce polemic against the “Repressive Hypothesis”, himself imagined a utopian Other where pleasure and desire were organised differently. I end on a discuss on Orientalism and the project of “Sinography” of comparative literature scholars Haun Saussy, Eric Hayot and others. 相似文献
805.
Jackson WM Lozito TP Djouad F Kuhn NZ Nesti LJ Tuan RS 《Journal of cellular and molecular medicine》2011,15(11):2377-2388
Mesenchymal stem cell (MSC) therapy is a promising approach to promote tissue regeneration by either differentiating the MSCs into the desired cell type or by using their trophic functions to promote endogenous tissue repair. These strategies of regenerative medicine are limited by the availability of MSCs at the point of clinical care. Our laboratory has recently identified multipotent mesenchymal progenitor cells (MPCs) in traumatically injured muscle tissue, and the objective of this study was to compare these cells to a typical population of bone marrow derived MSCs. Our hypothesis was that the MPCs exhibit multilineage differentiation and expression of trophic properties that make functionally them equivalent to bone marrow derived MSCs for tissue regeneration therapies. Quantitative evaluation of their proliferation, metabolic activity, expression of characteristic cell-surface markers and baseline gene expression profile demonstrate substantial similarity between the two cell types. The MPCs were capable of differentiation into osteoblasts, adipocytes and chondrocytes, but they appeared to demonstrate limited lineage commitment compared to the bone marrow derived MSCs. The MPCs also exhibited trophic (i.e. immunoregulatory and pro-angiogenic) properties that were comparable to those of MSCs. These results suggest that the traumatized muscle derived MPCs may not be a direct substitute for bone marrow derived MSCs. However, because of their availability and abundance, particularly following orthopaedic injuries when traumatized muscle is available to harvest autologous cells, MPCs are a promising cell source for regenerative medicine therapies designed to take advantage of their trophic properties. 相似文献
806.
807.
Anton D. van Staden Tiaan D. J. Heunis Leon M. T. Dicks 《Probiotics and antimicrobial proteins》2011,3(2):119-124
Maxillofacial and craniofacial surgery is on the increase, which exposes more patients at risk of acquiring microbial infections. The use of antibiotic-loaded calcium phosphate bone cements has been shown to reduce the incidence of infection. A marked increase in antibiotic-resistant pathogens, including multidrug-resistant pathogens, has been reported. This has led to the investigation of various compounds as alternatives to conventional treatments. In this paper, we report on the incorporation and release of a broad-spectrum class II antimicrobial peptide, bacteriocin ST4SA produced by Enterococcus mundtii, into a calcium orthophosphate-based bone cement. Our results suggest class II bacteriocins may be incorporated into self-setting bone cements to produce implants with antimicrobial activity over extended periods of time. 相似文献
808.
Liu Y Gibson J Wheeler J Kwee LC Santiago-Turla CM Akafo SK Lichter PR Gaasterland DE Moroi SE Challa P Herndon LW Girkin CA Budenz DL Richards JE Allingham RR Hauser MA 《PloS one》2011,6(11):e27134
DNA copy number variants (CNVs) have been reported in many human diseases including autism and schizophrenia. Primary Open Angle Glaucoma (POAG) is a complex adult-onset disorder characterized by progressive optic neuropathy and vision loss. Previous studies have identified rare CNVs in POAG; however, their low frequencies prevented formal association testing. We present here the association between POAG risk and a heterozygous deletion in the galactosylceramidase gene (GALC). This CNV was initially identified in a dataset containing 71 Caucasian POAG cases and 478 ethnically matched controls obtained from dbGAP (study accession phs000126.v1.p1.) (p = 0.017, fisher's exact test). It was validated with array comparative genomic hybridization (arrayCGH) and realtime PCR, and replicated in an independent POAG dataset containing 959 cases and 1852 controls (p = 0.021, OR (odds ratio) = 3.5, 95% CI -1.1-12.0). Evidence for association was strengthened when the discovery and replication datasets were combined (p = 0.002; OR = 5.0, 95% CI 1.6-16.4). Several deletions with different endpoints were identified by array CGH of POAG patients. Homozygous deletions that eliminate GALC enzymatic activity cause Krabbe disease, a recessive Mendelian disorder of childhood displaying bilateral optic neuropathy and vision loss. Our findings suggest that heterozygous deletions that reduce GALC activity are a novel mechanism increasing risk of POAG. This is the first report of a statistically-significant association of a CNV with POAG risk, contributing to a growing body of evidence that CNVs play an important role in complex, inherited disorders. Our findings suggest an attractive biomarker and potential therapeutic target for patients with this form of POAG. 相似文献
809.
Armand AS Laziz I Djeghloul D Lécolle S Bertrand AT Biondi O De Windt LJ Chanoine C 《PloS one》2011,6(11):e27283
Apoptosis Inducing Factor (AIF) is a highly conserved, ubiquitous flavoprotein localized in the mitochondrial intermembrane space. In vivo, AIF provides protection against neuronal and cardiomyocyte apoptosis induced by oxidative stress. Conversely in vitro, AIF has been demonstrated to have a pro-apoptotic role upon induction of the mitochondrial death pathway, once AIF translocates to the nucleus where it facilitates chromatin condensation and large scale DNA fragmentation. Given that the aif hypomorphic harlequin (Hq) mutant mouse model displays severe sarcopenia, we examined skeletal muscle from the aif hypomorphic mice in more detail. Adult AIF-deficient skeletal myofibers display oxidative stress and a severe form of atrophy, associated with a loss of myonuclei and a fast to slow fiber type switch, both in "slow" muscles such as soleus, as well as in "fast" muscles such as extensor digitorum longus, most likely resulting from an increase of MEF2 activity. This fiber type switch was conserved in regenerated soleus and EDL muscles of Hq mice subjected to cardiotoxin injection. In addition, muscle regeneration in soleus and EDL muscles of Hq mice was severely delayed. Freshly cultured myofibers, soleus and EDL muscle sections from Hq mice displayed a decreased satellite cell pool, which could be rescued by pretreating aif hypomorphic mice with the manganese-salen free radical scavenger EUK-8. Satellite cell activation seems to be abnormally long in Hq primary culture compared to controls. However, AIF deficiency did not affect myoblast cell proliferation and differentiation. Thus, AIF protects skeletal muscles against oxidative stress-induced damage probably by protecting satellite cells against oxidative stress and maintaining skeletal muscle stem cell number and activation. 相似文献
810.
Juuti-Uusitalo K Klunder LJ Sjollema KA Mackovicova K Ohgaki R Hoekstra D Dekker J van Ijzendoorn SC 《PloS one》2011,6(8):e22967