Hexavalent Chromium Reduction by Bacteria from Tannery Effluent

( Rida Batool ),( Kim Yrjala ),( Shahida Hasnain ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.4

Chromium is generated from several industrial processes. It occurs in different oxidation states, but Cr(III) and Cr(VI) are the most common ones. Cr(VI) is a toxic, soluble environmental contaminant. Some bacteria are able to reduce hexavalent chromium to the insoluble and less toxic Cr(III), and thus chromate bioremediation is of considerable interest. An indigenous chromium-reducing bacterial strain, Rb-2, isolated from a tannery water sample, was identified as Ochrobactrum intermedium, on the basis of 16S rRNA gene sequencing. The influence of factors like temperature of incubation, initial concentration of Cr, mobility of bacteria, and different carbon sources were studied to test the ability of the bacterium to reduce Cr(VI) under variable environmental conditions. The ability of the bacterial strain to reduce hexavalent chromium in artificial and industrial sewage water was evaluated. It was observed that the mechanism of resistance to metal was not due to the change in the permeability barrier of the cell membrane, and the enzyme activity was found to be inductive. Intracellular reduction of Cr(VI) was proven by reductase assay using cell-free extract. Scanning electron microscopy revealed chromium precipitates on bacterial cell surfaces, and transmission electron microscopy showed the outer as well as inner distribution of Cr(VI). This bacterial strain can be useful for Cr(VI) detoxification under a wide range of environmental conditions.

Gamification as a Helping Hand for Students’ Learning Adaptation due to Covid-19 Pandemic

Rida Afrilyasanti,Bambang Yudi Cahyono 아시아테플 2022 The Journal of Asia TEFL Vol.19 No.4

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TOPOLOGICALLY CONSISTENT TRIMMED SURFACE APPROXIMATIONS BASED ON TRIANGULAR PATCHES

Rida T. FAROUKI,Chang Yong HAN,Joel HASS,Thomas W. SEDERBERG 한국산업응용수학회 2005 한국산업응용수학회 학술대회 논문집 Vol.- No.-

Topologically consistent algorithms for the intersection and trimming of free-form parametric surfaces are of fundamental importance in computer-aided design, analysis, and manufacturing. Since the intersection of (for example) two bicubic tensor-product surface patches is not a rational curve, it is usually described by approximations in the parameter domain of each surface. If these approximations are employed as "trim curves", their images in ?³ do not agree precisely, and the resulting trimmed surfaces may exhibit "gaps" and "overlaps" along their common edge, an artifact that often incurs failure of downstream applications. We present a direct and simple approach to the problem, wherein the intersection curve is described explicitly by the sides of a sequence of triangular Bezier patches. Instead of representing trimmed surfaces by trim curves in the surface parameter domain, together with appropriate control point perturbations to guarantee consistency, we use triangular patches to directly approximate the intersection curve and the trimmed surfaces it defines. The triangular patches are constructed so as to maintain smooth (i.e., tangent-plane continuous) connections to untrimmed patches of the original surface. We assume that the original intersecting surfaces are subject to a subdivision process, such that the intersection segment (if any) on each sub-patch is a smooth arc between diametrically opposite corners. This guarantees that all intersection segments, and the trimmed surfaces they delineate, are "simple" enough to admit accurate approximation using triangular Bezier patches. Ensuring position and tangent plane agreement of degree-n triangular trimmed patch approximations p(r, s, t) and q(u, v, w) with given degree-(m, m) tensor-product patches p(r, s) and q(u, v) along the boundaries r = 0, s = 0 and u = 0, v = 0, and that the curve p(??, 1-??, 0) = q(??, 1-??, 0) matches the end points and tangents of the exact intersection, entails solving a linear system of 8m + 4n - 14 equations in 12n - 28 scalar variables. Although much of the ensuing discussion will be cast in a general context, our primary emphasis is the case of greatest practical interest-namely, the approximation of trimmed bicubic patches by quintic triangular patches. In this case, the tangent-plane matching conditions on the common patch sides entail solution of a linear system of 30 equations in 32 unknowns. Subsequent to solving this system, the degrees of freedom that remain to improve the approximation accuracy are the end-derivative magnitudes of the approximate intersection curve and is its two middle control points, and one "interior" control point for each triangular patch. Additional degrees of freedom may be introduced, to further improve the approximation accuracy, by elevating the degree of the quintic triangular patches. The elegant simplicity of this method, and the well-conditioned nature of the linear system that expresses the boundary conditions, makes it eminently suited to practical implementation. Many of the basic principles hold in contexts other than interesting bicubic patches with trimmed surfaces approximated by quintic triangular patches, although we expect this combination will be of greatest practical interest. The final trimmed surfaces resulting from the procedure described herein are hybrid collections of tensor-product (rectangular) patches and triangular patches. If homogeneity of the patch types in the final surface representation is an important consideration, known algorithms for converting a triangular patch into a set of tree rectangular patches or for splitting a rectangular patch into two triangular patches may be invoked.

The Role of a Dark Septate Endophytic Fungus, Veronaeopsis simplex Y34, in Fusarium Disease Suppression in Chinese Cabbage

Rida O. Khastini,Hiroyuki Ohta,Kazuhiko Narisawa 한국미생물학회 2012 The journal of microbiology Vol.50 No.4

The soil-inhabiting fungal pathogen Fusarium oxysporum has been an increasing threat to Chinese cabbage (Brassica campestris L.). A dark septate endophytic fungus, Veronaeopsis simplex Y34, isolated from Yaku Island, Japan, was evaluated in vitro for the ability to suppress Fusarium disease. Seedlings grown in the presence of the endophyte showed a 71% reduction in Fusarium wilt disease and still had good growth. The disease control was achieved through a synergetic effect involving a mechanical resistance created by a dense network of V. simplex Y34 hyphae, which colonized the host root, and siderophore production acting indirectly to induce a resistance mechanism in the plant. Changes in the relative abundance of the fungal communities in the soil as determined by fluorescently labelled T-RFs (terminal restriction fragments), appeared 3 weeks after application of the fungus. Results showed the dominance of V. simplex Y34, which became established in the rhizosphere and out-competed F. oxysporum.

Synthesis of Novel Benzofuran and Related Benzimidazole Derivatives for Evaluation of In Vitro Anti-HIV-1, Anticancer and Antimicrobial Activities

Rida, Samia M.,El-Hawash, Soad A.M.,Fahmy, Hesham T.Y.,Hazzaa, Aly A.,El-Meligy, Mostafa M.M. The Pharmaceutical Society of Korea 2006 Archives of Pharmacal Research Vol.29 No.10

Previously, we synthesized and evaluated several benzofuran derivatives containing heterocyclic ring substituents linked to the benzofuran nucleus at C-2 by a two- to four-atom spacer as potential anti-HIV-1, anticancer and antimicrobial agents. Among these derivatives, NSC 725612 and NSC 725716 exhibited interesting anti-HIV-1 activity. To further investigate the structure-activity relationship, we synthesized several new benzofuran derivatives derived from 2-acetylbenzofuran (2, 3a-c) and 2-bromoacetylbenzofuran (6; 7a,b; 8a,b). The compounds were designed to comprise the heterocyclic substituents directly linked to the benzofuran nucleus at C-2. Moreover, various related benzimidazoles derived from 2-acetylbenzimidazole and from 2-cyanomethylbenzimidazole (12a,b; 13a,b; 15; 16a,b) were also prepared as isosteres. The synthesized compounds were preliminarily evaluated for their in vitro anti-HIV-1, anticancer and antimicrobial activity. Compounds 2, 3a, 3b, and 12b showed weak anti-HIV-1 activity. Compound 6 exhibited mild activity against S. aureus, while compound 15 had mild activity towards S. aureus and C. albicans. However, no significant anticancer activity was observed with any of the tested compounds. From these results, we conclude that the presence of the spacer between the heterocyclic substituent and the benzofuran nucleus may be essential for the biological activity.

Instruction Type, Motivation, and Transferability in L1- Arabic and L2-French Speakers’ L3-English Cognates Pronunciation

Rida Farah,Mun-Hong Choe 한국영어교육학회 2022 ENGLISH TEACHING(영어교육) Vol.77 No.2

This study investigated the extent to which explicit and implicit instruction improve L1-Arabic speakers’ articulation of English words whose cognates were acquired earlier in their L2 French. Sixty-eight secondary school students, explicit (n=35) and implicit (n=33), participated in a programme incorporating focus-on-pronunciation activities, comprising three 45-minute sessions. Their learning motivation was first rated using an adapted version of Attitude/Motivation Test Battery (AMTB). Their pronunciation improvement was assessed through an oral-reading task. Ten new words were included in the post-test to see if they would generalize the instructed knowledge analogically. Results indicated that both explicit and implicit instruction had a positive impact on the students’ pronunciation advancement. However, the explicit group outperformed the implicit group with both the targeted and untaught words. There was insignificant interaction effect between instructional method and students’ motivation level, with higher motivation uniformly enhancing the effect of instruction. Nevertheless, motivation played a more crucial role in the learnt knowledge transferability when instruction was of implicit.

Effect of molar ration of Ti/Ligand on the synthesis of MIL-125(Ti) and its adsorption and photocatalytic properties

Rida Fatima,Seongjun Park,Jong-Oh Kim 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.90 No.-

In this study, a pristine MIL-125(Ti) was synthesized via a modified solvothermal method. The effect oftitanium metal ion to organic ligand ratio on surface and structural properties of material was investigated. With changing the Ti/Ligand ratios, the surface charge of catalyst changed, that was explained by Zetapotential. Moreover, surface area significantly dropped as Ti/Ligand molar ratio was increased or decreasedfrom 2:3, respectively. Furthermore, effect of these surface changes on physicochemical (adsorption andphotocatalysis) properties of material was investigated. Electrostatic potential and strong oxo and metalcluster peaks, mesoporosity, and good crystallinity were the reasons for enhanced adsorption andphotocatalytic properties of material. Isotherm studies of adsorption illustrated a monolayer adsorptionwith good favorability. In addition, photocatalysis followedfirst order kinetics with good sustainability thatwas explained by reusability results. Further, LC/MS analysis identified Rhodamine, benzoic acid,cyclohexanes, succinic acid, cyclohexylammonium, dimethylamine, and acetate as photocatalyticdegradation intermediates. Moreover, Quantitative evaluation of material revealed MIL-2 (Ti/Ligandratio = 2:3) as the best performing candidate among prepared MIL’s. Therefore, we propose a molar ratio of2:3 of Titanium metal ion to organic ligand for synthesis of pristine MIL-125(Ti).

Facile synthesis of RGO/MIL-125(Ti) for visible light photocatalytic application

Rida Fatima,Jong Oh Kim 대한환경공학회 2019 대한환경공학회 학술발표논문집 Vol.2019 No.-

Synthesis and In Vitro Evaluation of Some Novel Benzofuran Derivatives as Potential Anti-HIV-1, Anticancer, and Antimicrobial Agents

Rida, Samia M.,EI-Hawash, Soad A.M.,Fahmy, Hesham T.Y.,Hazza, Aly A.,EI-Meligy, Mostafa M.M. The Pharmaceutical Society of Korea 2006 Archives of Pharmacal Research Vol.29 No.1

A novel series of 1-(1-benzofuran-2-yl-ethylidene)-4-substituted thiosemicarbazides (2a-d) along with some derived ring systems: substituted-2,3-dihydro-thiazoles(3a-c, 4a-f) and thiazolidin-4-ones(5a-d and 6a-d), were synthesized. In addition, cyanoacetic acid-(1-benzofuran-2-yl-ethylidene) hydrazide(7) was used to prepare another new series of compounds consisting of substituted pyridin-2(1H)-ones(8a-c); 2-thioxo-2,3-dihydro-thiazoles(9a-d) and 2-thioxo-2,3-dihydro-6H-thiazolo[4,5-d]pyrimidin-7-ones (10a-c, 11a-c). The absolute configuration of compound 5c was determined by X-ray crystallography. The compounds prepared were evaluated for their in vitro anti-HIV, anticancer, antibacterial, and antifungal activities. Among the tested compounds, compounds 5c and 9a produced a significant reduction ㅐ ㄹ the viral cytopathic effect (93.19% and 59.55%) at concentrations $>2.0{\times}10^{-4}\;M\;and\;2.5{\times}10^{-5}\;M$respectively. Compound 9a was confirmed to have moderate anti-HIV activity. Compounds 2a, 2d, and 5c showed mild antifungal activity. However, none of the tested compounds showed any significant anticancer activity.

Investor Behavior Responding to Changes in Trading Halt Conditions: Empirical Evidence from the Indonesia Stock Exchange

Rida RAHIM,Desyetti SULAIMAN,Tafdil HUSNI,Nadya Ade WIRANDA 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.4

Information has an essential role in decision-making for investors who will invest in financial markets, especially regarding the policies on the condition of COVID-19. The purpose of this study is to determine the market reaction to the information published by the government regarding the policy changes to the provisions of Trading Halt on the IDX in an emergency using the event study method. The population in this study was companies listed on the Indonesia Stock Exchange in March 2020; the sample selection technique was purposive sampling. Data analysis used a normality test and one sample T-test. The results of the study found that there were significant abnormal returns on the announcement date, negative abnormal returns around the announcement date, and significant trading volume activity occurring three days after the announcement. The existence of a significant positive abnormal return on the announcement date indicates that the market responds quickly to information published by the government. The practical implication of this research can be taken into consideration for investors in making investment decisions to analyze and determine the right investment options so that investors can minimize the risk of their investment and maximize the profits they want to achieve.