1. Example: Consider the Fibonacci sequence {xn} defined recursively by ar1 = 1, x2 = 1, xn + l = xn + xn_l if n > 2. It is well known that the q-sequence corresponding to {xn} converges to the real number ( 1 + /5)/2. This example shows that divergent sequences {xn} can have corresponding ^-sequences that converge. On the other hand, examples can be found of convergent sequences of quotients o...

We have studied catabolite gene activator protein (CAP) activation at the araBAD promoter, pBAD, in the absence of DNA looping. We ruled out the two most plausible indirect activation mechanisms: CAP-induced folding of upstream DNA back upon RNA polymerase, and CAP-induced stabilization of AraC binding to DNA. Therefore, a direct CAP-RNA polymerase interaction seemed likely. We sought and found...

In herpes simplex virus type 1 (HSV-1)-infected HEp-2 cells, amanitin added before or at various times after infection always reduced viral multiplication. Also, the three waves of transcription of HSV-1 DNA, which led to the synthesis of alpha, beta-, and gamma-polypeptides, were all sensitive to amanitin in HEp-2 cells, and the amanitin-sensitive RNA polymerase activities of isolated nuclei w...

Using real-time x-ray scattering to measure the surface morphology of Au(111) during sputter erosion with 500 eV Ar ions, we observe three distinct regimes: three-dimensional rough erosion at 20–60 ±C, quasi-layer-by-layer removal at 120–220 ±C, and step retraction above 270 ±C. Sputtering at 20–60 ±C leads to pattern formation with a characteristic spacing between features. The average separat...

armillaria root and crown rot is an important disease of woody plants including fruit, forest and ornamental trees in different regions. the disease is common in isfahan and causes economical losses on a broad range of fruit trees. there only a few tolerant varieties to disease, and there is no efficient method in controlling the disease. therefore, detection of the pathogen from soil is necess...

The recent outbreaks of Escherichia coli O157-associated food poisoning have focused attention on the virulence determinants of E. coli. Here, it is reported that single base substitutions in the fnr gene encoding the oxygen-responsive transcription regulator FNR (fumarate and nitrate reduction regulator) are sufficient to confer a hemolytic phenotype on E. coli K12, the widely used laboratory ...

The development of perennial grain crops is driven by the vision simultaneous food production and enhanced ecosystem services. Typically, like intermediate wheatgrass (IWG)[Thinopyrum intermedium (Host) Barkworth & D.R Dewey] have low seed yield other detrimental traits. Next-generation sequencing has made genomic selection (GS) a tractable viable breeding method. To investigate how an IWG prog...

Antibody responses of pigs to defined Erns fragments, after classical swine fever virus (CSFV) infection, were studied by using an enzyme-linked immunosorbent assay (ELISA). Selection of various E(rns) fragments was based on an immunodominant Erns region encompassing three overlapping antigenic regions, amino acids 65 to 145 (Erns(aa)65-145) (AR1), 84 to 160 (Erns(aa)84-160) (AR2), and 109 to 2...

Abstract Argentine stem weevil adults (ASW, Listronotus bonariensis ) feed on the leaves of agricultural grasses and their larvae mine pseudostem, causing extensive damage that can result in plant death. Plants emit volatiles serve as signals to host-searching insects these odours be altered by both herbivory fungal endophyte-infection. This study investigated whether ASW utilise olfaction iden...