225 research outputs found
Aspergillus westerdijkiae polyketide synthase gene āaoks1ā is involved in the biosynthesis of ochratoxin A
OchratoxinA (OTA) is a potential nephrotoxic, teratogenic, immunogenic, hepatotoxic and carcinogenic mycotoxin, produced by Aspergillus westerdijkiae NRRL 3174. Herein we describe the characterization of a putative OTA-polyketide synthasegene āaoks1ā, cloned by using gene walking approach. The predicted amino acid sequence of the 2 kb clone display 34ā60% similarities to different polyketide synthasegenes including lovastatine biosynthesis gene ālovbā in A. terreus, compactin biosynthesis gene āmlcAā in Penicillium citrinum and OTA biosynthesis gene āotapksPNā in P. nordicum. Based on the reverse transcription PCR and kinetic secondary metabolites production studies, aoks1 expression was found to be associated with OTA biosynthesis. Further a mutant, in which the aoks1gene was inactivated by Escherichia coli hygromycin B phosphotransferase gene, lost the capacity to produce OTA, but still producing mellein. To our knowledge this report describes for the first time characterization of a gene involved in OTA biosynthesis, with the information about mellein which was proposed in the literature to be an intermediate OTA. This study also suggests that aoks1 may be the second polyketide synthase gene required for OTA biosynthesis in A. westerdijkiae NRRL 3174
The Secular Side of Islam: a Case Study of Tariq Aliās Islam Quintet
The present study discusses the secular side of Islamic civilization in Tariq Aliās Islam Quintet. Against the misrepresentation of Islam in the western discourse, Aliās Islam Quintet depicts the past history of Muslims that highlights the secular, tolerant, pluralistic and intellectual side of the Islamic civilization. The study is qualitative in nature. The technique of content analysis was used to analyse the texts of three novels ā Shadows of the pomegranate tree, The Book of Saladin, A Sultan in Palermo ā of Islam Quintet to argue that the author deconstructs the western notions about Islam and retells the history from otherās perspective. The analysis of the Shadows of the Pomegranate Tree demonstrates that the Muslims of Banu Hudayl lived secular lives and their actions and decisions were determined by material and economic motives. Furthermore, the study highlights the intellectual, rational, tolerant and secular side of some significant historical and fictional characters in āthe Book of Saladinā and āa Sultan in Palermoā. Keywords: Christian Europe, Islamic civilization, Islam Quintet, Orientalism, Secular aspec
LUCRATIVENESS OF ISLAMIC VS CONVENTIONAL MUTUAL FUNDS IN PAKISTAN
The purpose of this study is to conduct a comparative riskadjusted performance, selectivity skills and market timing abilitiesanalysis of Islamic and Conventional mutual funds in Pakistan. Thestudy utilizes various risk-adjusted performance measures to evaluaterisk and return characteristics. The study also used techniqueproposed by (Treynor and Mazuy 1966) and (Henriksson and Merton1981) to appraise selectivity skills and timing abilities on the dataset ranging 2009-2013 of Islamic and Conventional mutual funds. Inthis study, four categories Aggressive Fixed Income, Asset Allocation,Equity and Balanced open end mutual funds are analysed. On thebasis of evidences found, only few mutual fund managers from Islamicand Conventional mutual funds hold better stock picking skills. Themutual fund managers of both Islamic and conventional mutual fundsare found to be a poor market timer in Pakistan. Islamic mutualfunds have earned better returns than conventional mutual funds.Therefore, risk adjusted performance of Islamic mutual funds is betterthan conventional mutual funds
Ultrasound Imaging of Testes and Epididymides of Normal and Infertile Breeding Bulls
Echotexture of testes and epididymides from 10 slaughtered male buffaloes was studied. Diameter of testis and mediastinum testis was measured by ultrasound and compared with respective values taken by calipers. Testes and epididymides of another 10 fertile and 10 infertile breeding bulls were examined in vivo through manual palpation and ultrasound imaging. Semen quality of these bulls was also monitored. There were significant (P<0.01) positive correlations between ultrasound and calipers values of all parameters. The testicular parenchyma of fertile bulls was uniformly homogeneous and moderately echogenic. Epididymal tail was more heterogeneous and less echogenic, while epididymal head was homogeneous and less echogenic, than the testicular parenchyma. The epididymal body appeared as hypoechoic structure with echogenic margin. Among 10 infertile bulls, nine had poor semen quality, while one bull failed to give any ejaculate. On ultrasonography, six bulls showed abnormalities in their scrotal echotexture. Among these, one had an abundance of hyperechoic areas scattered in the testicular parenchyma, some of these showed acoustic shadowing, showing testicular degenerations with mineralization. The second bull showed many anechoic areas in the testes and epididymal head, demarcated from the rest of the organ by well defined margins. In the third bull, three-fourth of the right testis showed hyperechoic areas, suspected of testicular degeneration with mineralization. The fourth bull had two anechoic areas in one testis assumed to represent dilated blood vessel. The fifth bull showed small hyperechoic areas within the testicular parenchyma. The sixth bull showed an anechoic area with distinct hyperechogenic margin below the testicular tunics. The remaining four bulls had normal echogenicity of testes and epididymides in spite of poor semen quality. In conclusion, diagnostic ultrasound may be included in breeding soundness examination of breeding bulls
Review of Catalytic Transesterification Methods for Biodiesel Production
Attempts for improving the synthesis procedure of catalysts for fatty acid methyl ester production have been progressing for a considerable length of time. Biodiesel lessens net carbon dioxide emissions up to 78% with reference to conventional fuel. That is the reason for the improvement of new and operative solid catalysts necessary for inexhaustible and efficient fuel production. Homogenous base catalysts for transesterification is risky in light of the fact that its produces soap as byproduct, which makes difficult issues like product separation and not temperate for industrial application. In comparison, heterogeneous process gives higher quality FAME which can be effectively isolated and facilitate costly refining operations that are not required. A focus of this review article is to study and compare various biodiesel synthesis techniques that are being researched. The catalytic strength of numerous heterogeneous solid catalysts (acid and base), specially earth and transition metal oxides were also appraised. It was observed that catalytic proficiency relied upon a few factors, for example, specific surface area, pore size, volume and active site concentration at catalyst surface. This review article will give assistance in assortment of appropriate catalysts and the ideal conditions for biodiesel generation
PHYSICO-CHEMICAL ASSESSMENT OF WATER SAMPLES COLLECTED FROM SOME SELECTED STREAMS AND RIVERS IN DISTRICT GILGIT, PAKISTAN
This study aims to provide information about the drinking water quality of two streams in Chakarkote Sai and Demote Sai and two rivers in Gilgit and Hunza. Parameters were tested including physical, and chemical. The physical parameters were temperature, pH, electric conductivity (EC), total dissolved solids (TDS), turbidity, dissolved oxygen (DO), ammonia (NH4),total nitrogen (TN), total phosphorus (TP) and reactive orthophosphate (PO4). The ranges of these parameters set by WHO and NEQs, as most of the Asian countries also follow the WHO standards. All the samples were tested in the EPA certified laboratory of biological sciences department Karakorum international university Gilgit Baltistan. The minimum and maximum values of temperature 15.2-18.4, PH 6.78-6.09, EC 109.3-297 ĀµS, TDS 53.8-149 ppm, Turbidity 0.29-88.4 NTU, DO 7.1-8.9 mg/l, TN 5.63-7.13 mg/l, NH4 0.0106-0.0151 mg/l, TP 0.042-0.143mg/l, and PO4 0.0059-0.016 mg/l. Independent T test was applied separately for both streams and rivers to determine significant difference of water properties with respect to location wise. Water parameters like DO and TP were significantly, while temperature, PH, EC, TDS, turbidity, TN, NH4, PO4 were non-significant in streams and TDS, turbidity, DO and TN were significant, while temperature, PH, EC, NH4, TP, PO4 were non-significant in rivers according to area wise
Land suitability modelling using geographical information system (GIS) and multi-criteria decision making (MCDM)
There has been growing concern that the development activities have high potential to cause environmental problems. The decision-makers are trying hard to reinforce new policies and procedures towards sustainable development projects. Finding adequate land for any new business or development activity is a key factor considered in sustainable theories. Big projects involve numerous factors, and this makes land selection as a complex activity; thus, it is not easy to find the best suitable land parcel for development projects. Therefore, this chapter highlights the significance and effectiveness of GIS and MCDM in resolving various land suitability issues. The integration of GIS and various MCDM approaches is successfully seen in resolving land suitability problems in the world
Dose-response of cotton dust exposure with lung function among textile workers: MultiTex study in Karachi, Pakistan
Background: Cotton dust exposure among textile mill workers lead to impaired lung function. However, only few studies have investigated the dose-response relationship between cotton dust and lung function.Objective: To determine the dose-response relationship between cotton dust exposure and lung function among textile workers.Methods: This cross-sectional survey was conducted from January to March 2016 and included 303 adult male textile workers from spinning and weaving sections of 5 mills in Karachi, Pakistan. We collected data through a translated version of the American Thoracic Society respiratory questionnaire (ATS-DLD-78A) and using spirometry. Mill-level airborne cotton dust was measured over an 8-12-hour shift through UCB-PATS (University of California, Berkeley-Particle, and Temperature Monitoring System). Multiple linear regression was used to determine the association between cotton dust exposure and lung function assessed through the 3 indices: forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), and their ratio (FEV1/FVC).Results: The mean age of the workers was 32.5 (SD 10.5) years. The mean spirometry indices expressed in percent predicted values were FEV1 82.6 (SD 14.0); FVC 90.3 (14.7), and FEV1/FVC 94.9 (10.5). The median cotton dust concentration was 0.61 (IQR 0.2 to 1.3) mg/m3. The frequency of respiratory symptoms was 15% for cough, 20% for phlegm, and 20% for wheezing. After adjustment for covariates, every mg/m3 increase in dust concentration was associated with 5.4% decline in FEV1.Conclusion: This study quantifies the exposure-dependent relationship between cotton dust and lung function; which has implications for regulations and standards in the textile industry in Pakistan and similar cotton-processing countries
Cloning and characterization of novel methylsalicylic acid synthase gene involved in the biosynthesis of isoasperlactone and asperlactone in Aspergillus westerdijkiae
Aspergillus westerdijkiae is the main producer of several biologically active polyketide metabolites including isoasperlactone and asperlactone. A 5298 bp polyketide synthase gene āāaomsasā has been cloned in Aspergillus westerdijkiae by using gene walking approach and RACE-PCR. The predicted amino acid sequence of aomsas shows an identity of 40ā56% with different methylsalicylic acid synthase genes found in Byssochlamys nivea, P. patulum, A. terreus and Streptomyces viridochromogenes. Based on the reverse transcription PCR and kinetic secondary metabolites production studies, aomsas expression was found to be associated with the biosynthesis of isoasperlactone and asperlactone. Moreover an aomsas knockout mutant āāaoDmsasā of A. westerdijkiae, not only lost the capacity to produce isoasperlactone and asperlactone,but also 6-methylsalicylic acid. The genetically complemented mutant ao+msas restored the biosynthesis of all the missing metabolites. Chemical complementation through the addition of 6-methylsalicylic acid, aspyrone and diepoxide to growing culture of aoDmsas mutant revealed that these compounds play intermediate roles in the biosynthesis of asperlactone and isoasperlactone
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