The modern telecommunication industry demands higher capacity networks with high data rate. Orthogonal frequency division multiplexing (OFDM) is a promising technique for high data rate wireless communications at reasonable complexity in wireless channels. OFDM has been adopted for many types of wireless systems like wireless local area networks such as IEEE 802.11a, and digital audio/video bro...

The Escherichia coli phage shock protein system (pspABCDE operon and pspG gene) is induced by numerous stresses related to the membrane integrity state. Transcription of the psp genes requires the RNA polymerase containing the sigma(54) subunit and the AAA transcriptional activator PspF. PspF belongs to an atypical class of sigma(54) AAA activators in that it lacks an N-terminal regulatory doma...

The switch of RNA polymerase specificity from early to late promoters of bacteriophage T4 is achieved by substitution of host sigma factor, sigma 70, with the T4 induced factor, sigma gp55. However, overproduction of sigma gp55 from an expression vector is not detrimental to Escherichia coli growth. Direct competition binding assays demonstrate that sigma 70 readily displaces sigma gp55 from RN...

The evolution of halos consisting of weakly self-interacting dark matter particles is investigated using a new numerical Monte Carlo N-body method. The halos initially contain kinematically cold, dense r-1 power-law cores. For interaction cross sections sigma*=sigmawsi&solm0;mp>/=10-100 cm2 g-1, weak self-interaction leads to the formation of isothermal, constant-density cores within a Hubble t...

The value of the electrocardiogram in assessing infarct size was studied using serial estimates of the MB isomer of creatine kinase (CK MB) in plasma, serial 35 lead praecordial maps in 28 patients with anterior myocardial infarction, and serial 12 lead electrocardiograms in 17 patients with inferior myocardial infarction. In patients with anterior infarcts, sigma ST, sigma R, sigma Q, sigma R/...

Bacillus subtilis harbors seven extracytoplasmic function (ECF) sigma factors. At least three ECF sigma factors (sigma(M), sigma(W), and sigma(X)) are induced by, and provide resistance to, antibiotics and other agents eliciting cell envelope stress. Here, we report that ECF sigma factors also contribute to antibiotic production. B. subtilis 168 strains that are lysogenic for the SPbeta bacteri...

We used limited trypsin digestion to determine the domain organization of the Escherichia coli RNA polymerase sigma 70 subunit. Trypsin-resistant fragments containing sigma 70 conserved region 2 (sigma 70(2)), and carboxy-terminal fragments containing conserved regions 3 and 4 (sigma 70(3-4)) were identified by a combination of amino acid sequencing and mass spectrometry. The domains were studi...

The Bacillus subtilis rpoD gene has been sequenced and the primary structure of its product deduced. The molecular weight calculated for the sigma 43 is 42,828. The DNA and protein sequences of sigma 43 exhibit extensive homology to the Escherichia coli rpoD gene and its sigma 70 product, especially in the C-terminal two-thirds of the sequence. Other proteins exhibiting partial homology with si...

Bacterial actin homologues are thought to have a role in cell shape determination by positioning the cell wall synthetic machinery. They are also thought to control other functions, including cell polarity and chromosome segregation in various organisms. Bacillus subtilis and many other gram-positive bacteria have three actin isoforms, MreB, Mbl, and MreBH, which colocalize in helical structure...

Upon environmental changes, bacteria reschedule gene expression by directing alternative sigma factors to core RNA polymerase (RNAP). This sigma factor switch is achieved by regulating relative amounts of alternative sigmas and by decreasing the competitiveness of the dominant housekeeping sigma(70). Here we report that during stationary phase, the unorthodox Crl regulator supports a specific s...