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Circadian clocks in all organisms include feedback loops that generate rhythmic expression of key genes. We model the first such loop proposed for the clock of Arabidopsis thaliana, the experimental model species for circadian timing in higher plants. As for many biological systems, there are no experimental values for the parameters in our model, and the(More)
Circadian clocks involve feedback loops that generate rhythmic expression of key genes. Molecular genetic studies in the higher plant Arabidopsis thaliana have revealed a complex clock network. The first part of the network to be identified, a transcriptional feedback loop comprising TIMING OF CAB EXPRESSION 1 (TOC1), LATE ELONGATED HYPOCOTYL (LHY) and(More)
Our computational model of the circadian clock comprised the feedback loop between LATE ELONGATED HYPOCOTYL (LHY), CIRCADIAN CLOCK ASSOCIATED 1 (CCA1) and TIMING OF CAB EXPRESSION 1 (TOC1), and a predicted, interlocking feedback loop involving TOC1 and a hypothetical component Y. Experiments based on model predictions suggested GIGANTEA (GI) as a candidate(More)
The properties of human DNA fingerprints detected by multilocus minisatellite probes 33.6 and 33.15 have been investigated in 36 large sibships and in 1,702 Caucasian paternity cases involving the analysis of over 180,000 DNA fingerprint bands. The degree of overlap of minisatellite loci detected by these two probes is shown to be negligible (approximately(More)
We propose an alternative mechanism for the gating of biological membrane channels in response to membrane tension that involves a change in the slope of the membrane near the channel. Under biological membrane tensions we show that the energy difference between the closed (tilted) and open (untilted) states can far exceed k(B)T and is comparable to what is(More)
A protocol is presented for the purification of sporozoites from sporulated oocysts of Eimeria tenella. Two Percoll density gradients are the basis of the purification. The first gradient is used after glass-bead grinding to purify undamaged sporocysts; 87% of the sporocysts loaded onto the gradient were recovered in the pellet. The second gradient is used(More)
We present a model for the kinetics of spontaneous membrane domain (raft) assembly that includes the effect of membrane recycling ubiquitous in living cells. We show that domains can have a broad power-law distribution with an average radius that scales with the 1/4 power of the domain lifetime when the line tension at the domain edges is large. For(More)
We study a physical model for the formation of bud-like invaginations on fluid lipid membranes under tension, and apply this model to caveolae formation. We demonstrate that budding can be driven by membrane-bound proteins, provided that they exert asymmetric forces on the membrane that give rise to bending moments. In particular, caveolae formation does(More)
Measurements of leaf thickness and δ13C value were obtained for twenty species and three intergeneric hybrids of the Crassulaceae. The data include plants growing in their native habitats and also in greenhouse cultivation. There is a strong relationship between leaf thickness and leaf δ13C values. The plants with the thickest leaves of ca. 7 to 11 mm had(More)
Recently, five novel fluorescent proteins have been isolated from non-bioluminescent species of reef-coral organisms and have been made available through ClonTech. They are AmCyan, AsRed, DsRed, ZsGreen and ZsYellow. These proteins are valuable as reporters for transformation because they do not require a substrate or external co-factor to emit fluorescence(More)