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Abrupt Rise (abrupt + rise)
Selected AbstractsDevelopmental cell death during Xenopus metamorphosis involves BID cleavage and caspase 2 and 8 activationDEVELOPMENTAL DYNAMICS, Issue 8 2006D. Du Pasquier Abstract Elimination of tadpole organs during Xenopus metamorphosis is largely achieved through apoptosis, and recent evidence suggest involvement of the mitochondrial death route and bax-initiated caspase-3 and -9 deployment. However, events upstream of the activation of Bax are unknown. In other models, proteins of the BH3-only group such as BID are known to assure this function. We show that Xenopus bid transcript levels increase at metamorphosis in larval cells destined to disappear. This increase correlates with an abrupt rise in Caspase-2 and -8 mRNA levels and an enhanced activity of Caspase-2 and -8. In BIDGFP transgenic animal's tail regression is accelerated. The cleavage of BIDGFP fusion protein during natural or T3 -induced metamorphosis was specifically inhibited by caspase-8 inhibitors. Our results show that tail regression at metamorphosis implicates an apoptotic pathway inducible by T3 hormone in an organ autonomous manner and involving the cell death executioners BID and Caspases-2 and -8. Developmental Dynamics 235:2083,2094, 2006. © 2006 Wiley-Liss, Inc. [source] Oral compression activity on a surrogate nipple in the newborn rat: Nutritive and nonnutritive suckingDEVELOPMENTAL PSYCHOBIOLOGY, Issue 4 2003Andrey P. Kozlov Abstract Newborn rats, 3 hr after birth and before any experience in suckling, were exposed for 10 min to a surrogate nipple providing milk. One hour later, they were exposed to an empty nipple for another 10-min period. The basic characteristics of oral behavior (oral compression activity, OCA) were assessed by recording intranipple pressure during the pups' first attachment to a nipple. The peculiarities of milk-induced changes of OCA were examined with three modes of milk delivery (milk infusions, and intermittent and continuous milk deliveries). The pattern of OCA exerted by the newborn pups on a surrogate nipple consisted of rhythmic oscillations within a frequency range of 0.4 to 1.0 Hz, superimposed on slow (frequency,<,0.2 Hz), irregular intranipple pressure fluctuations. Oral behavior during the first minute after oral capture of the nipple differed significantly from that during any subsequent 1-min interval in terms of frequency content of OCA. The pattern of OCA changes induced by milk infusions or intermittent milk delivery included an abrupt rise in intranipple pressure, accompanied or followed by a burst of fast nipple compressions (bites). Our data suggest that newborn rats attached to a surrogate nipple demonstrate patterns of oral behavior that simulate, in terms of basic frequency characteristics, patterns of nutritive and nonnutritive suckling observed in more mature pups on the maternal nipple. © 2003 Wiley Periodicals, Inc. Dev Psychobiol 43: 290,303, 2003. [source] Chronology of latest Pleistocene lake-level fluctuations in the pluvial Lake Chewaucan basin, Oregon, USAJOURNAL OF QUATERNARY SCIENCE, Issue 6 2001Joseph M. Licciardi Abstract New accelerator mass spectrometer radiocarbon ages from gastropods in shore deposits within the pluvial Lake Chewaucan basin, combined with stratigraphical and geomorphological evidence, identify an abrupt rise and fall of lake level at ca. 12 14C ka. The lake-level high is coeval with lake-level lows in the well-dated records of palaeolakes Bonneville and Lahontan, and with a period of relatively wet conditions in the more southerly Owens Lake basin. This spatial pattern of pluvial lake levels in the western USA at 12 14C ka indicates a variable synoptic response to climate forcing at this time. Copyright © 2001 John Wiley & Sons, Ltd. [source] Mean-Square Radius of Gyration and Degree of Branching of Highly Branched Copolymers Resulting from the Copolymerization of AB2 With AB MonomersMACROMOLECULAR THEORY AND SIMULATIONS, Issue 8 2004Zhiping Zhou Abstract Summary: The evolution of the various structural units incorporated into hyperbranched polymers formed from the copolymerization of AB2 and AB monomers has been derived by the kinetic scheme. The degree of branching was calculated with a new definition given in this work. The degree of branching monotonously increased with increasing A group conversion (x) and the maximum value could reach 2r/(1,+,r)2, where r is the initial fraction of AB2 monomers in the total. Like the average degree of polymerization, the mean-square radius of gyration of the hyperbranched polymers increased moderately with A group conversion in the range x,<,0.9 and displayed an abrupt rise when the copolymerization neared completion. The characteristic ratio of the mean-square radius of gyration remained constant for the linear polymers. However, the hyperbranched polymers did not possess this character. In comparison with the linear polymerization, the weight average and z -average degree of polymerization increased due to the addition of the branched monomer units AB2 and the mean-square radius of gyration decreased quickly for the products of copolymerization. [source] Comparison of the Embryotoxic Effects of Saporin, Agrostin (Type 1 Ribosome-Inactivating Proteins) and Ricin (a Type 2 Ribosome-Inactivating ProteinBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 6 2001Wood-Yee Chan Saporin and agrostin had similar embryotoxicity which was approximately 105 times weaker than that of ricin and its A and B chains, and the embryotoxicity of saporin and agrostin increased gradually with the dosage. In contrast, there was an abrupt rise in embryotoxictiy of ricin-A chain and B chain as the dose was raised from 10 to 20 ng ml,1. Saporin and agrostin did not affect the heart-beat and otic placode, but at 10 ng ml,1 ricin and 40 ng ml,1 ricin-A chain and B chain, all of the treated embryos exhibited abnormalities in heart-beat, yolk sac circulation, body axis, optic placode, otic placode, forelimb buds, branchial apparatus and cranial neural tube. [source] | ||||||||||