Comparative in silico analysis of ftsZ gene from different bacteria reveals the preference for core set of codons in coding sequence structuring and secondary structural elements determination.

The deluge of sequence information in the recent times provide us with an excellent opportunity to compare organisms on a large genomic scale. In this study we have tried to decipher the variation in the gene organization and structuring of a vital bacterial gene called ftsZ which codes for an integral component of the bacterial cell division, the FtsZ protein. FtsZ is homologous to tubulin protein and has been found to be ubiquitous in eubacteria. FtsZ is showing increasing promise as a target for antibacterial drug discovery. Our study of ftsZ protein from 143 different bacterial species spanning a wider range of morphological and physiological type demonstrates that the ftsZ gene of about ninety three percent of the organisms show relatively biased codon usage profile and significant GC deviation from their genomic GC content. Comparative codon usage analysis of ftsZ and a core housekeeping gene rpoB demonstrated that codon usage pattern of ftsZ CDS is shaped by natural selection to a large extent and mimics that of a housekeeping gene. We have also detected a tendency among the different organisms to utilize a core set of codons in structuring the ftsZ coding sequence. We observed that the compositional frequency of the amino acid serine in the FtsZ protein appears to be a indicator of the bacterial lifestyle. Our meticulous analysis of the ftsZ gene linked with the corresponding FtsZ protein show that there is a bias towards the use of specific synonymous codons particularly in the helix and strand regions of the multi-domain FtsZ protein. Overall our findings suggest that in an indispensable and vital protein such as FtsZ, there is an inherent tendency to maintain form for optimized performance in spite of the extrinsic variability in coding features

A generalized fundamental principle

Let ν be a rank 1 henselian valuation of a field K having unique extension ῡ to an algebraic closure K̅ of K. For any subextension L/K of K̅/K, let G (L), Res (L) denote respectively the value group and the residue field of the valuation obtained by restricting ῡ to L. If a ∑ K̅/K define δK(a)=sup{ν̅(a-c)|c∑K̅,[K(C):K]<[K(a):K]} ωK(a)=max{ν̅(a-a1)|a1≠a runs over K-conjugates of a}

Generalized Hensel's lemma

Let (K, v) be a complete, rank-1 valued field with valuation ring Rv, and residue field kv. Let vx be the Gaussian extension of the valuation v to a simple transcendental extension K(x) defined by vx(∑,a1x3=mini{v(ai)}inline1 The classical Hensel's lemma asserts that if polynomials F(x), G0(x), H0(x) in Rv[x] are such that (i) v0(F(x) – G0(x)H0(x)) > 0, (ii) the leading coefficient of G0(x) has v-valuation zero, (iii) there are polynomials A(x), B(x) belonging to the valuation ring of vx satisfying vx(A(x)G0(x) + B(x)H0(x) – 1) > 0, then there exist G(x), H(x) in K[x] such that (a) F(x) = G(x)H(x), (b) deg G(x) = deg G0(x), (c) vx(G(x)–G0(x)) > 0, vx(H(x) – H0(x)) > 0. In this paper, our goal is to prove an analogous result when vx is replaced by any prolongation w of v to K(x), with the residue field of wa transcendental extension of kv

A uniqueness problem in valued function fields of conics

Let v0 be a valuation of a field K0 with value group G0. Let K be a function field of a conic over K0, and let v be an extension of v0 to K with value group G such that G/G0 is not a torsion group. Suppose that either (K0, v0) is henselian or v0 is of rank 1, the algebraic closure of K0 in K is a purely inseparable extension of K0, and G0 is a cofinal subset of G. In this paper, it is proved that there exists an explicitly constructible element t in K, with v(t) non-torsion modulo G0 such that the valuation of K0(t), obtained by restricting v, has a unique extension to K. This generalizes the result proved by Khanduja in the particular case, when K is a simple transcendental extension of K0 (compare [4]). The above result is an analogue of a result of Polzin proved for residually transcendental extensions [8]

On a generalization of Eisenstein's irreducibility criterion

Let ν be a valuation of any rank of a field K with value group G<SUB>ν</SUB> and f(X)= X<SUP>m</SUP> + a<SUB>l</SUB>X<SUP>m&#8722;1</SUP> + … + a<SUB>m</SUB> be a polynomial over K. In this paper, it is shown that if (ν(a<SUB>i</SUB>)/i)≥(ν(a<SUB>m</SUB>)/m)>0 for l≤i≤m, and there does not exist any integer r>1 dividing m such that ν(a<SUB>m</SUB>)/r&#8712;G<SUB>ν</SUB>, then f(X) is irreducible over K. It is derived as a special case of a more general result proved here. It generalizes the usual Eisenstein Irreducibility Criterion and an Irreducibility Criterion due to Popescu and Zaharescu for discrete, rank-1 valued fields, (cf. [Journal of Number Theory, 52 (1995), 98–118])

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Not AvailableA new and rapid method for simultaneous identification and estimation of bioactive triterpenoid glycosides [asiaticoside (AS) and madecassoside (MS)] and their aglycones [asiatic acid (AA) and madecassic acid (MA)] in Centella asiatica was developed by using high-performance liquid chromatography (HPLC) coupled with triple-quadrupole mass spectrometry (MS/MS). Estimation was based on multiple reaction monitoring (MRM) using the precursor → product ion combination for determination of four analytes using Alltima C18 column (50 × 4.6 mm, 3 µm). An electrospray ionization (ESI) tandem interface in positive mode was employed prior to mass-spectrometric detection. The method was subjected to a thorough validation procedure in terms of linearity, limit of detection (LOD) and quantification (LOQ), accuracy, and precision. Six-point calibration curves were linear in the range of 50–500 ng mL−1 for ng mL−1 for AS and MS, and 25–250 ng mL−1 for AA and MA, with excellent linearity (R2 > 0.98). With the optimized conditions, the four analytes were detected accurately within 10 min. LOD and LOQ ranged from 2.5 to 5 and 10 to 15 ng mL−1, respectively. Method accuracy in terms of average recoveries of all four analytes ranged between 98.61 and 102.85 % at three spiking levels with intra- and interday precision relative standard deviation (RSD, %) of 1.01–4.62 and 1.13–4.16, respectively. The new method was successfully applied to estimate the concentration of these four bioactive compounds in extracts of C. asiatica prepared by nonpolar-to-polar solventsICA

Evaluation of Tincture Prepared from <i>Jussiaea suffruticosa </i>Linn.

587-590Tincture of Jussiaea suffruticosa Linn. is prepared from different strengths of alcohol such as 30,40,50,60,70,80,90, and 100 per cent v/v by maceration period of 7,14, and 21 d and some co-chemical properties like pH, specific gravity, total solid matter content and the presence of chemical components are examined. From the examined parameters, it is observed that the tincture prepared from 50 per cent v/v alcohol yields maximum total solid content, maximum specific gravity value and shows pH 5.01. It is inferred that the tincture of Jussiaea suffruticosa prepared with 50 per cent per cent v/v alcohol is useful to achieve maximum therapeutic efficacy