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Let $n > 1 $ be a fixed positive integer and $S$ be a subset of a ring $R$. A mapping $\zeta$ of a ring $R$ into itself is called $n$-skew-commuting on $S$ if $\zeta(x)x^{n} + x^{n}\zeta(x)=0$, $\forall$ $x\in S.$ The main aim of this paper is to describe $n$-skew-commuting mappings on appropriate subsets of $R$. With this, many known results can be either generalized or deduced. In particular, this solves the conjecture in [M. Nadeem, M. Aslam and M.A. Javed, On $2$-skew commuting additive mappings of prime rings, Gen. Math. Notes, 2015]. The second main result of this paper is concerned with a pair of linear mappings of $C^*$-algebras. We show that here, if $C^*$-Algebra admits a pair of linear mappings $f$ and $g$ such that $f(x)x^* + x^*g(x) \in Z(A)$ for all $x \in A,$ then both $f$ and $g$ must be zero. As the applications of first main result (Theorem $2.1$) and apart from proving some other results, we characterize the linear mappings on primitive $C^*$-algebras. Furthermore, we provide an example to show that the assumed restrictions cannot be relaxed.

Let R be a noncommutative prime ring, U be the left Utumi quotient ring of R, and k, m, n, r be fixed positive integers. If there exist a generalized derivation G and a derivation g (which is independent of G) of R such that [G(xm)xn + xng(xm), xr]k = 0, for all x ∈ R, then there exists a ∈ U such that G(x) = ax, for all x ∈ R. As a consequence of the result in the present article, one may obtain Theorem 1 in Demir and Argac [10].

Let R be a ring with involution ′∗′. The skew Lie product of a, b ∈ R is defined by ∗[a, b] = ab − ba∗. The purpose of this paper is to study the commutativity of a prime ring which satisfies the various ∗-differential identities involving skew Lie product. Finally, we provide two examples to prove that the assumed restrictions on some of our results are not superfluous.

The resistance and pathogenesis of bacteria could be related to their ability to sense and respond to population density, termed quorum sensing (QS). Inhibition of the QS system is considered as a novel strategy for the development of antipathogenic agents, especially for combating drug-resistant bacterial infections. In the present study, the anti-QS activity of Onion peel ethylacetate fraction (ONE) was tested against Chromobacterium violaceum CV12472 and Pseudomonas aeruginosa PAO1. ONE inhibit the QS-mediated virulence factors production such as violacein in C. violaceum and elastase, pyocyanin in P. aeruginosa. Further, the treatment with sub-MICs of ONE significantly inhibited the QS-mediated biofilm formation, EPS (Extracellular polymeric substances) production and swarming motility. Further, quercetin 4′-O-β-D glucopyranoside (QGP) was isolated from ONE and its anti-QS potential was confirmed after observing significant inhibition of QS-controlled virulence factors such as violacein, elastase, pyocyanin and biofilm formation in test pathogens. Molecular docking analysis predicted that QGP should be able to bind at the active sites of Vfr and LasR, and if so blocks the entry of active sites in Vfr and LasR.

Let R be an associative ring. An additive mapping d : R → R is called a Jordan derivation if d ( x 2 ) = d ( x ) x + xd ( x ) holds for all x ∈ R . The objective of the present paper is to characterize a prime ring R which admits Jordan derivations d and g such that [ d ( x m ) , g ( y n ) ] = 0 for all x , y ∈ R or d ( x m ) ∘ g ( y n ) = 0 for all x , y ∈ R , where m ⩾ 1 and n ⩾ 1 are some fixed integers. This partially extended Herstein’s result in [6, Theorem 2] , to the case of (semi)prime ring involving pair of Jordan derivations. Finally, we apply these purely algebraic results to obtain a range inclusion result of continuous linear Jordan derivations on Banach algebras.

Let R be an associative ring. In the present paper, we investigate commutativity of a ring admitting an additive mapping F satisfying any one of the following properties: (i) F ([x, y]2 ) = F ([x2 , y2 ]), (ii) F ((x ◦ y)2 ) = F (x2 ◦ y2 ), (iii) F ((xy)n ) = F (xn yn ), (iv) F (xm yn ) = F (yn xm ), (v) (F (x)F (y))n = (F (y)F (x))n for all x, y ∈ R, where m and n are positive integers greater than 1. Moreover, some related results are also discussed. Finally, some examples are given to demonstrate that the restrictions imposed on the hypotheses of the various results are not superfluous.

Let R be an associative ring. A mapping f : R −→ R is said to be additive if f (x +y) = f (x) +f (y) holds for all x;y ∈ R: An additive mapping d : R −→ R is called a derivation if d(xy) = d(x)y + xd(y) holds for all x;y ∈ R: In this paper, we investigate commutativity of prime and semiprime rings satisfying certain identities involving additive mappings and derivations. Moreover, some results have also been discussed.

In this paper we dene the notions of left -bimultiplier, -bimultiplier and generalized -biderivation, and to prove that if a semiprime -ring admits a left - bimultiplier M, then M maps R R into Z(R). In Section 3, we discuss the applications of theory of -bimultipliers. Further, it was shown that if a semiprime -ring R admits a symmetric generalized -biderivation G : R R ! R with an associated nonzero symmet- ric -biderivation B : R R ! R, then G maps R R into Z(R). As an application, we establish corresponding results in the setting of C -algebra.

BACKGROUND: Application of insecticides in modern agriculture in order to enhance legume production has led to their accumulation in soils to levels that adversely affect soil microflora such as rhizobia and exert a negative impact on the physiological activities associated with them. This study was therefore designed to identify rhizobial strains expressing higher tolerance to insecticides fipronil and pyriproxyfen and synthesising plant growth regulators even amid insecticide stress. RESULTS: The fipronil- and pyriproxyfen-tolerant Rhizobium sp. strain MRL3 produced plant-growth-promoting substances in substantial amounts, both in the presence and in the absence of the insecticides. In general, both insecticides at recommended and higher rates reduced plant dry biomass, symbiotic properties, nutrient uptake and seed yield of lentil plants. Interestingly, when applied with any concentration of the two insecticides, Rhizobium sp. strain MRL3 significantly increased the measured parameters compared with plants grown in soils treated solely with the same concentration of each insecticide but without inoculant. CONCLUSION: This study suggests that Rhizobium strain MRL3 may be exploited as a bioinoculant to augment the efficiency of lentil exposed to insecticide-stressed soils.

Plant growth promoting rhizobacteria (PGPR) are known to influence plant growth by various direct or indirect mechanisms. In search of efficient PGPR strains with multiple activities, a total of 72 bacterial isolates belonging to Azotobacter, fluorescent Pseudomonas, Mesorhizobium and Bacillus were isolated from different rhizospheric soil and plant root nodules in the vicinity of Aligarh. These test isolates were biochemically characterized. These isolates were screened in vitro for their plant growth promoting traits like production of indoleacetic acid (IAA), ammonia (NH(3)), hydrogen cyanide (HCN), siderophore, phosphate solubilization and antifungal activity. More than 80% of the isolates of Azotobacter, fluorescent Pseudomonas and Mesorhizobium ciceri produced IAA, whereas only 20% of Bacillus isolates was IAA producer. Solubilization of phosphate was commonly detected in the isolates of Bacillus (80%) followed by Azotobacter (74.47%), Pseudomonas (55.56%) and Mesorhizobium (16.67%). All test isolates could produce ammonia but none of the isolates hydrolyzed chitin. Siderophore production and antifungal activity of these isolates except Mesorhizobium were exhibited by 10-12.77% isolates. HCN production was more common trait of Pseudomonas (88.89%) and Bacillus (50%). On the basis of multiple plant growth promoting activities, eleven bacterial isolates (seven Azotobacter, three Pseudomonas and one Bacillus) were evaluated for their quantitative IAA production, and broad-spectrum (active against three test fungi) antifungal activity. Almost at all concentration of tryptophan (50-500 microg/ml), IAA production was highest in the Pseudomonas followed by Azotobacter and Bacillus isolates. Azotobacter isolates (AZT(3), AZT(13), AZT(23)), Pseudomonas (Ps(5)) and Bacillus (B(1)) showed broad-spectrum antifungal activity on Muller-Hinton medium against Aspergillus, one or more species of Fusarium and Rhizoctonia bataticola. Further evaluation of the isolates exhibiting multiple plant growth promoting (PGP) traits on soil-plant system is needed to uncover their efficacy as effective PGPR.

Made available in DSpace on 2015-10-22T06:29:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-05-13. Added 1 bitstream(s) on 2015-10-22T09:46:03Z : No. of bitstreams: 1 WOS000355832500001.pdf: 8351305 bytes, checksum: e895a7b4d27ef3b9a80dbdda4bc6d728 (MD5) Deanship of Scientific Research at KSU Bacterial quorum sensing (QS) is a density dependent communication system that regulates the expression of certain genes including production of virulence factors in many pathogens. Bioactive plant extract/compounds inhibiting QS regulated gene expression may be a potential candidate as antipathogenic drug. In this study anti-QS activity of peppermint (Menthe piperita) oil was first tested using the Chromobacterium violaceum CVO26 biosensor. Further, the findings of the present investigation revealed that peppermint oil (PMO) at sub-Minimum Inhibitory Concentrations (sub-MICs) strongly interfered with acyl homoserine lactone (AHL) regulated virulence factors and biofilm formation in Pseudomonas aeruginosa and Aeromonas hydrophila. The result of molecular docking analysis attributed the QS inhibitory activity exhibited by PMO to menthol. Assessment of ability of menthol to interfere with QS systems of various Gram-negative pathogens comprising diverse AHL molecules revealed that it reduced the AHL dependent production of violacein, virulence factors, and biofilm formation indicating broad-spectrum anti-QS activity. Using two Escherichia colt biosensors, MG4/pKDT17 and pEAL08-2, we also confirmed that menthol inhibited both the las and pqs QS systems. Further, findings of the in vivo studies with menthol on nematode model Caenorhabditis elegans showed significantly enhanced survival of the nematode. Our data identified menthol as a novel broad spectrum QS inhibitor. Department of Agricultural Microbiology, Aligarh Muslim University, Aligarh, India Department of Food Science and Nutrition, College of Food and Agricultural Sciences, King Saud University, Riyadh, Saudi Arabia Department of Zoology, Aligarh Muslim University, Aligarh, India Department of Biochemistry, Protein Research Chair, College of Science, King Saud University, Riyadh, Saudi Arabia School of Pharmaceutical Sciences, Sao Paulo State University, Araraquara, Brazil Deanship of Scientific Research at KSU: RGP-215

Induction of an appropriate immune response against gonadotrophin releasing hormone (GnRH-I) disrupt fertility, reduce fecundity and regress tumours of reproductive system.To disrupt fertility a plasmid DNA vaccine was engineered coding eight repeats of GnRH-I and eight T-helper epitopes. Translation efficiency of the vaccine was evaluated in undifferentiated COS1 cells and found to release GnRH-I fusion protein in culture supernatant. Swiss albino female mice (N=24) were immunized with 50μg plasmid DNA construct in study weeks 0, 3, 6, 9 and 12. Group 2 mice were primed with the plasmid DNA in hemagglutinating virus of japanese envelope (HVJE) vector and subsequent boosts were carried out in phosphate buffer saline. Group 3 mice were immunized with the plasmid DNA in non-ionic surfactant vesicles (NISV) and Group 1 was served as untreated control. The effect of immunization was studied in terms of anti-GnRH-I antibody response (OD value at A540 ± SD), suppression of ovarian folliculogenesis, altered uterine histoarchitecture and impaired fertility in vivo in mating trials. In study week 24 OD values of anti- GnRH-I antibody response were 0.982 ± 0.231 in Group 3 mice, followed by 0.783 ± 0.191 in Group 2 in comparison with no response in Group 1 controls (0.237 ± 0.147). Results of mating trials showed conception failure in vaccinated mice; 51, 18 and 05 pups were seen in the uteri of Groups 1, 2 and 3 mice respectively. There was significant (p>0.001) reduction in the weight of ovaries in Group 2 (8.50 ± 2.38 mg) and Group 3 (7.25 ± 0.95 mg) mice compared to Group 1 control (15.00 ± 1.41 mg). Significant reduction of ovarian folliculogenesis was seen in Group 2 (p>0.001) and Group 3 mice (p>0.01). In conclusion, the plasmid DNA vaccine delivered in female mice with HVJE and NISV induced significantly (p>0.001) higher levels of anti-GnRH-I antibody response, suppressed ovarian and uterine function and impaired fertility in vivo.

Let [Formula: see text] be an associative ring with center [Formula: see text] The objective of this paper is to discuss the commutativity of a semiprime ring [Formula: see text] which admits a derivation [Formula: see text] such that [Formula: see text] for all [Formula: see text] or [Formula: see text] for all [Formula: see text] or [Formula: see text] for all [Formula: see text] where [Formula: see text] and [Formula: see text] are fixed positive integers. Finally, we apply these purely ring theoretic results to obtain commutativity of Banach algebra via derivation.

We investigate commutativity of the ring R involving some additive mapping with necessary torsion restrictions on commutators. We give counter examples which show that the hypotheses of our theorems are not superfluous.