Participation of the hypophyseal-adrenal cortex system in thrombin clearance during immobilization stress

Thrombin marked with I-131 resulted in a considerable increase of the thrombined clearance rate in healthy male rats during stress caused by an immobilization lasting 30 minutes, and in an increase of thrombin clearance occurred by a combination of immobilization and administration of adrenocorticotropin (ACTH). Contrary to ACTH, the thrombin clearance is not stimulated in healthy animals by hydrocortisone. The results of the examination are presented

An iterative strategy combining biophysical criteria and duration hidden Markov models for structural predictions of Chlamydia trachomatis σ66 promoters

<p>Abstract</p> <p>Background</p> <p>Promoter identification is a first step in the quest to explain gene regulation in bacteria. It has been demonstrated that the initiation of bacterial transcription depends upon the stability and topology of DNA in the promoter region as well as the binding affinity between the RNA polymerase σ-factor and promoter. However, promoter prediction algorithms to date have not explicitly used an ensemble of these factors as predictors. In addition, most promoter models have been trained on data from <it>Escherichia coli</it>. Although it has been shown that transcriptional mechanisms are similar among various bacteria, it is quite possible that the differences between <it>Escherichia coli </it>and <it>Chlamydia trachomatis </it>are large enough to recommend an organism-specific modeling effort.</p> <p>Results</p> <p>Here we present an iterative stochastic model building procedure that combines such biophysical metrics as DNA stability, curvature, twist and stress-induced DNA duplex destabilization along with duration hidden Markov model parameters to model <it>Chlamydia trachomatis </it>σ⁶⁶promoters from 29 experimentally verified sequences. Initially, iterative duration hidden Markov modeling of the training set sequences provides a scoring algorithm for <it>Chlamydia trachomatis </it>RNA polymerase σ⁶⁶/DNA binding. Subsequently, an iterative application of Stepwise Binary Logistic Regression selects multiple promoter predictors and deletes/replaces training set sequences to determine an optimal training set. The resulting model predicts the final training set with a high degree of accuracy and provides insights into the structure of the promoter region. Model based genome-wide predictions are provided so that optimal promoter candidates can be experimentally evaluated, and refined models developed. Co-predictions with three other algorithms are also supplied to enhance reliability.</p> <p>Conclusion</p> <p>This strategy and resulting model support the conjecture that DNA biophysical properties, along with RNA polymerase σ-factor/DNA binding collaboratively, contribute to a sequence's ability to promote transcription. This work provides a baseline model that can evolve as new <it>Chlamydia trachomatis </it>σ⁶⁶promoters are identified with assistance from the provided genome-wide predictions. The proposed methodology is ideal for organisms with few identified promoters and relatively small genomes.</p

THE MILLIMETER - WAVE SPECTRUM OF TRICARBON OXIDE SULFIDE

Author Institution: Physikalisch-Chemisches Institut, Justus-Liebig-Universit$\bar{a}$t Giessen; Physikalisch-Chemisches Institut, Institute of Electronic Measurements KVARZ; Applied Physics Institute, Russian Academy of SciencesThe millimeter-wave spectrum of tricarbon oxide sulfide, $C_{3}OS$, has been recorded continuously between 78.3 GHz and 118.1 GHZ with average detection sensitivity of around $10^{-7} cm^{-1}$. The measurements were made possible with a newly designed millimeter-wave synthesizer provided by the company Kvarz, Nizhny Novgorod, Russia. The instrument features a backward wave oscillator tube as a source of radiation. The output frequency is phase-locked to an external quarz oscillator stabilised on a standard radio signal. All settings of the instrument (frequency increments, number of frequency steps per second etc.) and the data acquisition are controlled by a personal computer. The stability of the output signal in frequency, amplitude and phase allows us to subtract the background spectrum, recorded separately with the absorption cell empty, from the sample spectrum. The difference yields a spectrum with a very flat zero-level. The measured frequency range covers the rotational spectrum of the linear molecule $C_{3}OS$ starting at $J = 28 \leftarrow 27$ up to $J = 41 \leftarrow 40$. About 5000 pure rotational transitions have been recorded in this range. The spectrum is dominated by rotational transitions arising from excited states of the low-lying bending vibration $\nu_{7}$ around $78 cm^{-1}$. Rotational satellites of hotbands up to $\nu_{7} = 9$ and many combination bands, where this vibrational mode is involved, can easily be detected. This explains the large number of rotational transitions for this linear molecule. The experimental conditions in recording the spectra and a first analysis of the $C_{2}OS$ data will be presented

Hochaufloesendes Diffraktometer MINI-SFINKS

Translated from Russian, originally published as report LINP--1277.With 18 figs., 3 tabs.SIGLEAvailable from TIB Hannover: RA 3251(91/E/82) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman