63 research outputs found
Negative order KdV equation with both solitons and kink wave solutions
In this paper, we report an interesting integrable equation that has both
solitons and kink solutions. The integrable equation we study is
, which actually comes from the negative KdV
hierarchy and could be transformed to the Camassa-Holm equation through a gauge
transform. The Lax pair of the equation is derived to guarantee its
integrability, and furthermore the equation is shown to have classical
solitons, periodic soliton and kink solutions
GSK-3alpha directly regulates beta-adrenergic signaling and the response of the heart to hemodynamic stress in mice.
The glycogen synthase kinase-3 (GSK-3) family of serine/threonine kinases consists of 2 highly related isoforms, alpha and beta. Although GSK-3beta has an important role in cardiac development, much remains unknown about the function of either GSK-3 isoform in the postnatal heart. Herein, we present what we believe to be the first studies defining the role of GSK-3alpha in the mouse heart using gene targeting. Gsk3a(-/-) mice over 2 months of age developed progressive cardiomyocyte and cardiac hypertrophy and contractile dysfunction. Following thoracic aortic constriction in young mice, we observed enhanced hypertrophy that rapidly transitioned to ventricular dilatation and contractile dysfunction. Surprisingly, markedly impaired beta-adrenergic responsiveness was found at both the organ and cellular level. This phenotype was reproduced by acute treatment of WT cardiomyocytes with a small molecule GSK-3 inhibitor, confirming that the response was not due to a chronic adaptation to LV dysfunction. Thus, GSK-3alpha appears to be the central regulator of a striking range of essential processes, including acute and direct positive regulation of beta-adrenergic responsiveness. In the absence of GSK-3alpha, the heart cannot respond effectively to hemodynamic stress and rapidly fails. Our findings identify what we believe to be a new paradigm of regulation of beta-adrenergic signaling and raise concerns given the rapid expansion of drug development targeting GSK-3
Genome sequencing and analysis of the versatile cell factory Aspergillus niger CBS 513.88
The filamentous fungus Aspergillus niger is widely exploited by the fermentation industry for the production of enzymes and organic acids, particularly citric acid. We sequenced the 33.9-megabase genome of A. niger CBS 513.88, the ancestor of currently used enzyme production strains. A high level of synteny was observed with other aspergilli sequenced. Strong function predictions were made for 6,506 of the 14,165 open reading frames identified. A detailed description of the components of the protein secretion pathway was made and striking differences in the hydrolytic enzyme spectra of aspergilli were observed. A reconstructed metabolic network comprising 1,069 unique reactions illustrates the versatile metabolism of A. niger. Noteworthy is the large number of major facilitator superfamily transporters and fungal zinc binuclear cluster transcription factors, and the presence of putative gene clusters for fumonisin and ochratoxin A synthesis
Stability of subharmonics and behaviour of bifurcations to chaos on toral van der pol equation
Exact and explicit analytic solutions of an extended Jabotinsky functional differential equation
Humification Degree as a Proxy Climatic Record Since the Last Deglaciation Derived from a Limnological Sequence in South China
An accurate and robust method for the measurement of circular holes based on binocular vision
Deletion of GSK-3β in mice leads to hypertrophic cardiomyopathy secondary to cardiomyoblast hyperproliferation
Based on extensive preclinical data, glycogen synthase kinase–3 (GSK-3) has been proposed to be a viable drug target for a wide variety of disease states, ranging from diabetes to bipolar disorder. Since these new drugs, which will be more powerful GSK-3 inhibitors than lithium, may potentially be given to women of childbearing potential, and since it has controversially been suggested that lithium therapy might be linked to congenital cardiac defects, we asked whether GSK-3 family members are required for normal heart development in mice. We report that terminal cardiomyocyte differentiation was substantially blunted in Gsk3b–/– embryoid bodies. While GSK-3α–deficient mice were born without a cardiac phenotype, no live-born Gsk3b–/– pups were recovered. The Gsk3b–/– embryos had a double outlet RV, ventricular septal defects, and hypertrophic myopathy, with near obliteration of the ventricular cavities. The hypertrophic myopathy was caused by cardiomyocyte hyperproliferation without hypertrophy and was associated with increased expression and nuclear localization of three regulators of proliferation — GATA4, cyclin D1, and c-Myc. These studies, which we believe are the first in mammals to examine the role of GSK-3α and GSK-3β in the heart using loss-of-function approaches, implicate GSK-3β as a central regulator of embryonic cardiomyocyte proliferation and differentiation, as well as of outflow tract development. Although controversy over the teratogenic effects of lithium remains, our studies suggest that caution should be exercised in the use of newer, more potent drugs targeting GSK-3 in women of childbearing age
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