175 research outputs found
Fuzzy Functional Differential Equations under Dissipative-Type Conditions
Fuzzy functional differential equations with continuous right-hand sides are studied. The existence and uniqueness of a solution are proved under dissipative-type conditions. The continuous dependence of the solution on the initial conditions is shown. The existence of the solution on an infinite interval and its stability are also analyzed.Вивчаються нєчіткі функціонально-диференціальні рівняння з неперервною правою частиною. Доведено існування та єдиність розв'язку за умов дисипативного типу. Встановлено неперервну залежність розв'язку від початкових умов. Також розглянуто питання про існування розв'язку на нескінченному інтервалі та його стійкість
Preventive Approach to Unsubstantiated Claims and Disputes in the UK Construction Industry
Globally, claims and disputes are an unfortunate reality in construction projects. Recent statistics reveal that construction claims in the UK increased by 21% in 2018 compared to other countries such as India (8%), Mexico (3%), Ireland (2%), and Cyprus (2%). Though, construction industry is known for array of standard forms of contract and administrative tendencies; unsubstantiated claims and chronic disputes remain prevalent in the sector. Yet, there is little research on preventive approach to unsubstantiated claims that ultimately lead to disputes. The study advocates the use of Systematic and Technical Appraisal (STA) to prevent unsubstantiated claims and disputes in the construction industry. The study research method is based on qualitative research technique and use of case studies. The research question is: does systematic and technical appraisal of construction claims help prevent unsubstantiated claims and disputes in the UK construction industry? The study population sample is drawn from experienced industry stakeholders including clients, contractors, consultants, experienced quantity surveyors and cost managers in addition to use of construction case studies. Initial findings reveal that claim management processes in the construction sector are far-off from perfection. Other findings reveal that robust systematic and technical claim appraisal process has potential to prevent unsubstantiated claims; which in most cases lead to disputes. The study is part of an on-going PhD study to seek to develop an effective claim management system for the UK construction industry
Connections between the stability of a Poincare map and boundedness of certain associate sequences
Let and be two natural numbers and let be the -periodic discrete evolution family of matrices, having complex scalars as entries, generated by -valued, -periodic sequence of matrices We prove that the solution of the following discrete problem is bounded for each and each -vector if the Poincare map is stable. The converse statement is also true if we add a new assumption to the boundedness condition. This new assumption refers to the invertibility for each of the matrix By an example it is shown that the assumption on invertibility cannot be removed. Finally, a strong variant of Barbashin's type theorem is proved
Comparison of various oxidative treatments for removal of reactive black CNN
Decolorization of reactive black CNN by chemical oxidation and reduction using KMnO4, H2O2 and Ferrioxalate as oxidizing agents and Na2SO3 as reducing agent individually as well as in combination was studied on batch scale using UV-visible spectroscopy. Degradation of dye occurred in acidic medium with KMnO4 and in alkaline medium with H2O2 and ferrioxalate. The most efficient methods for decolorization of reactive black CNN is oxidation using KMnO4 as an oxidizing agent which removed 97.64% of dye. Maximum decolorization was obtained at 60 min of treatment under static conditions. H2O2 and ferrioxalate could remove only 50.71 and 44.21% dye, respectively. Sequential treatment was more successful with H2O2 and ferrioxalate when compared with KMnO4. Chemical oxygen demand (COD) and total organic carbon (TOC) contents of treated wastewater decreased appreciably from 83.6 to 63.7 mg/L and 86.8 to 72.8 mg/L, respectively. Additionally, Fourier Transform Infrared Spectroscopy (FTIR) study revealed the degradation of reactive black CNN after treatment into non toxic products.Keywords: Reactive black CNN, KMnO4, ferrioxalate, sodium sulphite, chemical oxygen demand (COD)
Effect of plant growth promoting rhizobacteria on root morphology of Safflower (Carthamus tinctorius L.)
Rooting characteristics significantly affect the water-use patterns and acquirement of nutrient for any plant species. Plant growth promoting rhizobacteria improve the plant growth by a variety of ways like the production of phytohormones, nitrogen fixation, phosphate solubilization and improvement in root morphology etc, and are also useful in cutting down the cost of chemical fertilizers. The present investigation was carried out to determine the comparative effect of plant growth promoting rhizobacteria (PGPR), Azospirillum brasilense, Azotobacter vinelandii and Pseudomonas stutzeri, either alone or in combination with different doses of chemical fertilizers [full dose (Urea at 60 kg ha-1 and DAP at 30 kg ha-1), half dose (Urea 30 kg ha-1 and DAP 15 kg ha-1) and quarter dose (Urea 15 kg ha-1 and DAP 7.5 kg ha-1)] on root morphology and root distribution pattern of safflower (Carthamus tinctorius L.) viz. cvv. Thori and Saif-32 in the soil. The PGPR were applied as seed inoculation at 106 cells/ml prior to sowing. P. stutzeri either alone or in combination with full dose of chemical fertilizers, was highly effective in increasing the root area in cv. Saif-32, whereas, the percent increase due to A. brasilense was comparable to that of treatment with full dose of chemical fertilizers. P. stutzeri inoculation resulted in significantly higher root length in both the cultivars. Significantly, higher root width (54%) of cv. Thori was observed in treatment receiving inoculation with A. vinelandii and supplemented with half dose of chemical fertilizers, whereas maximum root width of cv. Saif-32 was recorded in treatment supplemented with half dose of chemical fertilizers. It is inferred that PGPR inoculation especially those of A. brasilense and P. stutzeri either alone and more so in combination with half dose of chemical fertilizers, are highly effective in improving root morphology and growth in safflower.Key words: Root area, safflower, plant growth promoting rhizobacteria (PGPR), root growth, chemical fertilizers
Structural and functional analysis of the Escherichia coli acid-sensing histidine kinase EvgS
The EvgS/EvgA two-component system of Escherichia coli is activated in response to low pH and alkali metals and regulates many genes, including those for the glutamate-dependent acid resistance system and a number of efflux pumps. EvgS, the sensor kinase, is one of five unconventional histidine kinases (HKs) in E. coli and has a large periplasmic domain and a cytoplasmic PAS domain in addition to phospho-acceptor, HK and dimerization, internal receiver, and phosphotransfer domains. Mutations that constitutively activate the protein at pH 7 map to the PAS domain. Here, we built a homology model of the periplasmic region of EvgS, based on the structure of the equivalent region of the BvgS homologue, to guide mutagenesis of potential key residues in this region. We show that histidine 226 is required for induction and that it is structurally colocated with a proline residue (P522) at the top of the predicted transmembrane helix that is expected to play a key role in passing information to the cytoplasmic domains. We also show that the constitutive mutations in the PAS domain can be further activated by low external pH. Expression of the cytoplasmic part of the protein alone also gives constitutive activation, which is lost if the constitutive PAS mutations are present. These findings are consistent with a model in which EvgS senses both external and internal pH and is activated by a shift from a tight inactive to a weak active dimer, and we present an analysis of the purified cytoplasmic portion of EvgS that supports this
Fine-grained sentiment analysis for measuring customer satisfaction using an extended set of fuzzy linguistic hedges
© 2020 The Authors. Published by Atlantis Press SARL. In recent years, the boom in social media sites such as Facebook and Twitter has brought people together for the sharing of opinions, sentiments, emotions, and experiences about products, events, politics, and other topics. In particular, sentiment-based applications are growing in popularity among individuals and businesses for the making of purchase decisions. Fuzzy-based sentiment analysis aims at classifying customer sentiment at a fine-grained level. This study deals with the development of a fuzzy-based sentiment analysis by extending fuzzy hedges and rule-sets for a more efficient classification of customer sentiment and satisfaction. Prior studies have used a limited number of linguistic hedges and polarity classes in their rule-sets, resulting in the degraded efficiency of their fuzzy-based sentiment analysis systems. The proposed analysis of the current study classifies customer reviews using fuzzy linguistic hedges and an extended rule-set with seven sentiment analysis classes, namely extremely positive, very positive, positive, neutral, negative, very negative, and extremely negative. Then, a fuzzy logic system is applied to measure customer satisfaction at a fine-grained level. The experimental results demonstrate that the proposed analysis has an improved performance over the baseline works
Role of bacillus cereus in improving the growth and phytoextractability of brassica nigra (L.) K. Koch in chromium contaminated soil
Plant growth-promoting rhizobacteria (PGPR) mediate heavy metal tolerance and improve phytoextraction potential in plants. The present research was conducted to find the potential of bacterial strains in improving the growth and phytoextraction abilities of Brassica nigra (L.) K. Koch. in chromium contaminated soil. In this study, a total of 15 bacterial strains were isolated from heavy metal polluted soil and were screened for their heavy metal tolerance and plant growth promotion potential. The most efficient strain was identified by 16S rRNA gene sequencing and was identified as Bacillus cereus. The isolate also showed the potential to solubilize phosphate and synthesize siderophore, phytohormones (indole acetic acid, cytokinin, and abscisic acid), and osmolyte (proline and sugar) in chromium (Cr+3 ) supplemented medium. The results of the present study showed that chromium stress has negative effects on seed germination and plant growth in B. nigra while inoculation of B. cereus improved plant growth and reduced chromium toxicity. The increase in seed germination percentage, shoot length, and root length was 28.07%, 35.86%, 19.11% while the fresh and dry biomass of the plant increased by 48.00% and 62.16%, respectively, as compared to the uninoculated/control plants. The photosynthetic pigments were also improved by bacterial inoculation as compared to untreated stress-exposed plants, i.e., increase in chlorophyll a, chlorophyll b, chlorophyll a + b, and carotenoid was d 25.94%, 10.65%, 20.35%, and 44.30%, respectively. Bacterial inoculation also resulted in osmotic adjustment (proline 8.76% and sugar 28.71%) and maintained the membrane stability (51.39%) which was also indicated by reduced malondialdehyde content (59.53% decrease). The antioxidant enzyme activities were also improved to 35.90% (superoxide dismutase), 59.61% (peroxide), and 33.33% (catalase) in inoculated stress-exposed plants as compared to the control plants. B. cereus inoculation also improved the uptake, bioaccumulation, and translocation of Cr in the plant. Data showed that B. cereus also increased Cr content in the root (2.71-fold) and shoot (4.01-fold), its bioaccumulation (2.71-fold in root and 4.03-fold in the shoot) and translocation (40%) was also high in B. nigra. The data revealed that B. cereus is a multifarious PGPR that efficiently tolerates heavy metal ions (Cr+3 ) and it can be used to enhance the growth and phytoextraction potential of B. nigra in heavy metal contaminated soil
Mutational analysis of xenobiotic metabolizing genes (CYP1A1 and GSTP1) in sporadic head and neck cancer patients
CYP1A1 is the phase I enzyme that detoxifies the carcinogen or converts it into a more electrophilic form, metabolized by phase II enzymes like GSTP1. These detoxifying genes have been extensively studied in association with head and neck cancer (HNC) in different ethnic groups worldwide. The current study was aimed at screening genetic polymorphisms of genes CYP1A1 and GSTP1 in 388 Pakistani HNC patients and 150 cancer-free healthy controls, using PCR-SSCP. No already known variants of either gene were found, however a novel frameshift mutation due to insertion of T (g.2842_2843insT) was observed in the CYP1A1 gene. A statistically significant number (5.4%) of HNC cases, with the mean age of 51.75 (±15.7) years, presented this frameshift mutation in the conserved domain of CYP1A1. Another novel substitution mutation in was found in the GSTP1 gene, presenting TA instead of AG. The g.2848A > T polymorphism causes a leucine-to-leucine formation, whereas g.2849G > A causes alanine-to-threonine formation at amino acid positions 166 and 167, respectively. These exonic mutations were found in 9.5% of the HNC patients and in none of the controls. In addition, two intronic deletions of C (g.1074delC and g.1466delC) were also found in 11 patients with a mean age of 46.2 (±15.6) years. In conclusion, accumulation of mutations in genes CYP1A1 and GSTP1 appears to be associated with increased risk of developing HNC, suggesting that mutations in these genes may play a role in the etiology of head and neck cancer
Exopolysaccharides producing bacteria for the amelioration of drought stress in wheat
This research was designed to elucidate the role of exopolysaccharides (EPS) producing bacterial strains for the amelioration of drought stress in wheat. Bacterial strains were isolated from a farmer’s field in the arid region of Pakistan. Out of 24 isolated stains, two bacterial strains, Bacillus subtilis (Accession No. MT742976) and Azospirillum brasilense (Accession No. MT742977) were selected, based on their ability to produce EPS and withstand drought stress. Both bacterial strains produced a good amount of EPS and osmolytes and exhibited drought tolerance individually, however, a combination of these strains produced higher amounts of EPS (sugar 6976 µg/g, 731.5 µg/g protein, and 1.1 mg/g uronic acid) and osmolytes (proline 4.4 µg/mg and sugar 79 µg/mg) and significantly changed the level of stress-induced phytohormones (61%, 49% and 30% decrease in Indole Acetic Acid (IAA), Gibberellic Acid (GA), and Cytokinin (CK)) respectively under stress, but an increase of 27.3% in Abscisic acid (ABA) concentration was observed. When inoculated, the combination of these strains improved seed germination, seedling vigor index, and promptness index by 18.2%, 23.7%, and 61.5% respectively under osmotic stress (20% polyethylene glycol, PEG6000). They also promoted plant growth in a pot experiment with an increase of 42.9%, 29.8%, and 33.7% in shoot length, root length, and leaf area, respectively. Physiological attributes of plants were also improved by bacterial inoculation showing an increase of 39.8%, 61.5%, and 45% in chlorophyll a, chlorophyll b, and carotenoid content respectively, as compared to control. Inoculations of bacterial strains also increased the production of osmolytes such asproline, amino acid, sugar, and protein by 30%, 23%, 68%, and 21.7% respectively. Co-inoculation of these strains enhanced the production of antioxidant enzymes such as superoxide dismutase (SOD) by 35.1%, catalase (CAT) by 77.4%, and peroxidase (POD) by 40.7%. Findings of the present research demonstrated that EPS, osmolyte, stress hormones, and antioxidant enzyme-producing bacterial strains impart drought tolerance in wheat and improve its growth, morphological attributes, physiological parameters, osmolytes production, and increase antioxidant enzymes
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