sequence of per was diminished. Were PER and TIM Circadian rhythms, based upon a 24 hr cycle, function acting as competitive inhibitors of heterodimerization by in both eukaryotes and prokaryotes to keep the organism sequestering dCLK, or were they preventing the dCLKin tune with its environment. Endogenous cell-autonoCYC heterodimer from binding DNA? Lee et al. found mous clocks control daily ...

Members of the CYCLOIDEA (CYC)/TEOSINTE-BRANCHED1 (TB1) group of transcription factors have been implicated in the evolution of zygomorphic (i.e., bilaterally symmetric) flowers in Antirrhinum and Lotus and the loss of branching phenotype during the domestication of maize. The composite inflorescences of sunflower (Helianthus annuus L. Asteraceae) contain both zygomorphic and actinomorphic (i.e...

Ventilatory patterns and respiratory timing were measured in 14 subjects during cycling (CYC) and treadmill exercise (TM) at similar leg frequencies (fLEG) to determine if mode of exercise affects patterns of ventilation and respiratory timing. Measurements of breathing frequency (fR), tidal volume (VT), expired ventilation (VE), and inspiratory (TI) and expiratory (TE) time were obtained at fL...

The cycloidea (cyc) and teosinte branched 1 (tb1) genes code for structurally related proteins implicated in the evolution of key morphological traits. However, the biochemical function of CYC and TB1 proteins remains to be demonstrated. To address this problem, we have analysed the predicted secondary structure of regions conserved between CYC and TB1, and looked for related proteins of known ...

We report here that, contrary to previously reported findings, treatment of S49 wild-type (WT) lymphoma cells with 0-50 nM epinephrine resulted in a heterologous desensitization of adenylyl cyclase (EC 4.6.1.1)--that is, epinephrine and prostaglandin E1 (PGE1) stimulations of adenylyl cyclase were reduced. Observation of this heterologous desensitization required the assay of adenylyl cyclase w...

OBJECTIVE The aim of this study was to assess the value of four drug regimens for newly diagnosed severe LN from a societal perspective. METHODS A model-based cost-utility analysis was devised to measure lifetime costs and health outcomes. Current treatment options consisting of different combinations of i.v. CYC, AZA and MMF were compared with a baseline regimen of i.v. CYC in both the induc...

The Cyc project, started by Doug Lenat at MCC in 1984, is the most ambitious knowledge representation project ever undertaken. It embodies Lenat's current ideas for a system intended to encode all of commonsense knowledge. By the year 1999, he hopes that "no one would even think of buying a computer that doesn't have Cyc running on it". The book by Lenat and Guha is a report on the project as i...

To study the physiological effects of chronic intermittent hypoxia on neuronal excitability and function in mice, we exposed animals to cyclic hypoxia for 8 h daily (12 cycles/h) for approximately 4 wk, starting at 2-3 days of age, and examined the properties of freshly dissociated hippocampal neurons in vitro. Compared with control (Con) hippocampal CA1 neurons, exposed (Cyc) neurons showed ac...

Transcription initiation of the yeast iso-1-cytochrome c gene (CYC-1) occurs in six major clusters at positions +1, +10, +16, +25, +34, and +43. Potential "TATA elements" lie upstream at positions -154, -106, -52, and -22. Analysis of the TATA region suggests that three of these TATA sequences are functional and contribute to initiation at CYC-1, with the -106 TATA promoting initiation at +1, +...