Search results for: inhibition theory

Authors: Asma Naim, Warda Mushtaq

Abstract:

Staphylococcus species are the most versatile and adaptive organism. They are widespread and naturally found on the skin, mucosa and nose in humans. Among these, Staphylococcus aureus is the most important species. These organisms act as opportunistic pathogens and can infect various organs of the host, causing minor skin infection to severe toxin mediated diseases, and life threatening nosocomial infections. Staphylococcus aureus has acquired resistance against β-lactam antibiotics by the production of β-lactamase, and Methicillin-Resistant Staphylococcus aureus (MRSA) strains have also been reported with increasing frequency. MRSA strains have been associated with nosocomial as well as community acquired infections. Medicinal plants have enormous potential as antimicrobial substances and have been used in traditional medicine. Search for medicinally valuable plants with antimicrobial activity is being emphasized due to increasing antibiotic resistance in bacteria. In the present study, the antibacterial potential of Rosmarinus officinalis (Rosemary) and Murraya koenigii (curry leaves) was evaluated. These are common household herbs used in food as enhancer of flavor and aroma. The crude aqueous infusion, decoction and ethanolic extracts of curry leaves and rosemary and essential oil of rosemary were investigated in the present study for antibacterial activity against multi-drug resistant Staphylococcus strains using well diffusion method. In the present study, 60 Multi-drug resistant clinical isolates of S. aureus (43) and Coagulase Negative Staphylococci (CoNS) (17) were screened against different concentrations of crude extracts of Rosmarinus officinalis and Murraya koenigii. Out of these 60 isolates, 43 were sensitive to the aqueous infusion of rosemary; 23 to aqueous decoction and 58 to ethanolic extract whereas, 24 isolates were sensitive to the essential oil. In the case of the curry leaves, no antibacterial activity was observed in aqueous infusion and decoction while only 14 isolates were sensitive to the ethanolic extract. The aqueous infusion of rosemary (50% concentration) exhibited a zone of inhibition of 21(±5.69) mm. against CoNS and 17(±4.77) mm. against S. aureus, the zone of inhibition of 50% concentration of aqueous decoction of rosemary was also larger against CoNS 17(±5.78) mm. then S. aureus 13(±6.91) mm. and the 50% concentrated ethanolic extract showed almost similar zone of inhibition in S. aureus 22(±3.61) mm. and CoNS 21(±7.64) mm. whereas, the essential oil of rosemary showed greater zone of inhibition against S. aureus i.e., 16(±4.67) mm. while CoNS showed 15(±6.94) mm. These results show that ethanolic extract of rosemary has significant antibacterial activity. Aqueous infusion and decoction of curry leaves revealed no significant antibacterial potential against all Staphylococcal species and ethanolic extract also showed only a weak response. Staphylococcus strains were susceptible to crude extracts and essential oil of rosemary in a dose depend manner, where the aqueous infusion showed highest zone of inhibition and ethanolic extract also demonstrated antistaphylococcal activity. These results demonstrate that rosemary possesses antistaphylococcal activity.

Keywords: antibacterial activity, curry leaves, multidrug resistant, rosemary, S. aureus

Procedia PDF Downloads 222

Authors: Betul Zehra Karagul

Abstract:

A game consists of strategies that each actor has in his/her own choice strategies, and a game regulates the certain rules in the strategies that the actors choose, express how they evaluate their knowledge and the utility of output results. Game theory examines the human behaviors (preferences) of strategic situations in which each actor of a game regards the action that others will make in spite of his own moves. There is a balance between each player playing a game with the final number of players and the player with a certain probability of choosing the players, and this is called Nash equilibrium. The insurance is a two-person game where the insurer and insured are the actors. Both sides have the right to act in favor of utility functions. The insured has to pay a premium to buy the insurance cover. The insured will want to pay a low premium while the insurer is willing to get a high premium. In this study, the state of equilibrium for insurance pricing was examined in terms of the insurer and insured with game theory.

Keywords: game theory, insurance pricing, Nash equilibrium, utility function

Procedia PDF Downloads 332

Authors: Nisrine Benzbiria, Abderrahmane Thoume, Mustapha Zertoubi

Abstract:

The goal of this research is to investigate the corrosion inhibition potential of functionalized graphene oxide (GO) with oxime derivative on AA2024-T3 surface in synthetic seawater. The utilization of functionalized graphene oxide is creating a category of corrosion inhibitors known as organically modified nanomaterials. In our work, the functionalization of GO by chalcone oxime enables graphene oxide to have enhanced water solubility and a good corrosion mitigation capacity. Fourier-transform infrared (FT-IR) spectroscopy was utilized to evaluate the main functional groups of the inhibitor. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curves (PDP) showed that the inhibitor acts as a mixed-type inhibitor. The inhibitory efficiency (IE) improved as the concentration increased to a value of 96% after one hour of exposure to a medium containing 60 mg/L ppm of the inhibitor. According to thermodynamic calculations, the adsorption of the inhibitor on the AA2024-T3 surface in 3% NaCl followed the Langmuir isotherm. The formation of a barrier layer was further confirmed by surface analysis. The protective film prevented the alloy dissolution and limited the accessibility of attacking ions, as evinced by solution analysis techniques.

Keywords: AA2024-T3, NaCl, electrochemical methods, FT-IR, SEM/AFM, DFT, MC simulation

Procedia PDF Downloads 34

Authors: Mohammed Auwal Ibrahim, Isa Yunusa, Nafisa Kabir, Shazali Ali Baba, Amina Muhammad Yushau, Suraj Suraj Ibrahim, Zaharaddeen Idris Bello, Suleiman Haruna Suleiman, Murtala Bindawa Isah

Abstract:

Background: Inhibition of intestinal maltase and sucrase prevents postprandial blood glucose excursions which are beneficial in ameliorating diabetes-associated complications. Objective: In this study, the inhibitory effects of fruit extracts of Parinari macrophylla, Detarium microcarpum, Ziziphus spina-christi, Z. mairei and Parkia biglobosa were investigated against intestinal maltase and sucrase. Methods: Rats were given co-administration of the fruit extracts with maltose or sucrose and blood glucose levels were measured at 0, 30, 90 and 120 min. Results: The glucose-time curves indicated that all the fruits had the most potent inhibitory effects on both maltase and sucrase within the first 30 min. The computed Area Under the Curves (AUC0-120)for all the fruits indicated more potent inhibitory effects against intestinal maltase than sucrase.The ED50 range for the fruits extract against maltase and sucrase were 647.15-1118.35 and 942.44-1851.94 mg/kg bw respectively. Conclusion: The data suggests that the fruits could prevent postprandial hyperglycemia via inhibition of intestinal maltase and sucrase.

Keywords: diabetes mellitus, fruits, α-glucosidases, maltase, sucrase

Procedia PDF Downloads 356

Authors: Sade Ogundipe

Abstract:

The private healthcare sector in the United Kingdom has experienced unprecedented challenges during times of crisis, necessitating effective leadership adaptability. This qualitative study delves into the dynamic landscape of leadership within the sector, particularly during crises, employing the lenses of complexity theory and institutional theory to unravel the intricate mechanisms at play. Through in-depth interviews with 25 various levels of leaders in the UK private healthcare sector, this research explores how leaders in UK private healthcare organizations navigate complex and often chaotic environments, shedding light on their adaptive strategies and decision-making processes during crises. Complexity theory is used to analyze the complicated, volatile nature of healthcare crises, emphasizing the need for adaptive leadership in such contexts. Institutional theory, on the other hand, provides insights into how external and internal institutional pressures influence leadership behavior. Findings from this study highlight the multifaceted nature of leadership adaptability, emphasizing the significance of leaders' abilities to embrace uncertainty, engage in sensemaking, and leverage the institutional environment to enact meaningful changes. Furthermore, this research sheds light on the challenges and opportunities that leaders face when adapting to crises within the UK private healthcare sector. The study's insights contribute to the growing body of literature on leadership in healthcare, offering practical implications for leaders, policymakers, and stakeholders within the UK private healthcare sector. By employing the dual perspectives of complexity theory and institutional theory, this research provides a holistic understanding of leadership adaptability in the face of crises, offering valuable guidance for enhancing the resilience and effectiveness of healthcare leadership within this vital sector.

Keywords: leadership, adaptability, decision-making, complexity, complexity theory, institutional theory, organizational complexity, complex adaptive system (CAS), crises, healthcare

Procedia PDF Downloads 23

Authors: Mina Darabi Amin

Abstract:

In 1972, Hans Robert Jauss introduced the Reception Theory a version of Reader-response criticism, that suggests the literary critics to re-examine the relationship between the author, the work and the reader. The revealing of these relationships has shown that, besides the creation, the reception and the reading of the text have different levels which exempt it from a continuous reference to the meaning intended by the artist and could lead to multiplicity of possible interpretations according to the ‘Horizon of Expectations’. This theory could be associated with another intellectual process called ‘translation’, a process that is always confronted by different levels of readers in the target language and different levels of reception by these readers. By adopting the perspective of Reception theory in translation, we could ignore a particular kind of translation and consider the initiation to a literary text, its translation and its reception as a continuous process. Just like the creation of the text, the translation and its reception, are not made once and for all; they are confronted with different levels of reception and interpretation which are made and remade endlessly. After having known and crossing the first levels, the Horizons of Expectation could be extended and the reader could be initiated to the higher levels. On the other hand, we could say that the faithful and free translation are not opposed to each other, but depending on the type of reception by the readers and in a particular moment, the existence of both is necessary. In fact, it is the level of reception in readers and their Horizon of Expectations that determine the degree of fidelity and freedom of translation.

Keywords: reception theory, reading, literary translation, horizons of expectation, reader

Procedia PDF Downloads 158

Authors: Shohnaza Uzokova Beknazarovna

Abstract:

This research study provides a comprehensive exploration of the Theory of Media Activity and its relevance as a conceptual framework for journalism education. The author offers a thorough review of existing literature on media activity theory, emphasizing its potential to enhance the understanding of the evolving media landscape and its implications for journalism practice. Through a combination of theoretical analysis and practical examples, the paper elucidates the ways in which the Theory of Media Activity can inform and enrich journalism education, particularly in relation to the interactive and participatory nature of contemporary media. The author presents a compelling argument for the integration of media activity theory into journalism curricula, emphasizing its capacity to equip students with a nuanced understanding of the reciprocal relationship between media producers and consumers. Furthermore, the paper discusses the implications of technological advancements on media production and consumption, highlighting the need for journalism educators to prepare students to navigate and contribute to the future of journalism in a rapidly changing media environment. Overall, this research paper offers valuable insights into the potential benefits of embracing the Theory of Media Activity as a foundational framework for journalism education. Its thorough analysis and practical implications make it a valuable resource for educators, researchers, and practitioners seeking to enhance journalism pedagogy in response to the dynamic nature of contemporary media.

Keywords: theory of media activity, journalism education, media landscape, media production, media consumption, interactive media, participatory media, technological advancements, media producers, media consumers, journalism practice, contemporary media environment, journalism pedagogy, media theory, media studies

Procedia PDF Downloads 25

Authors: Lele Zhang, Hui Leng Choo, Alexander Konyukhov, Shuguang Li

Abstract:

Finite Element (FE) model of simplified e-bike structure was generated by main frame with two tiers, which consisted of pipe, mass, beam, and shell elements (pipe 289, beam188, shell 181, shell 281, combin14, link11, mass21). These elements would be introduced and demonstrated using mathematical formulas. Based on coupling theory, constrain equations was proposed. Exporting all the parameters obtained from theory part, the connection stiffness matrix of the whole e-bike structure between each of these elements was detected.

Keywords: coupling theory, stiffness matrix, e-bike, finite element model

Procedia PDF Downloads 352

Authors: Abeer Y. Ibrahim, Faten M. Ibrahim, Samah A. El-Newary, Saber F. Hendawy

Abstract:

Objective: Appreciation of in-vitro anti-inflammatory and antioxidant characters of Vitex agnus-castus berries alcoholic extract and fractions, as well as in-vivo antitumor ability of alcoholic extract and chloroform fraction against Ehrlich ascites carcinoma is the aim of this study. Material and methods: Antioxidant properties of crude alcoholic extract of vitex berries as well as petroleum ether, chloroform, ethyl acetate and butanol fractions were evaluated, in-vitro assessments, as compared with standard materials, l-ascorbic acid (vitamin C) and butylated hydroxyl toluene(BHT). The anti-inflammatory activity was investigated in cyclooxygenase (COX)-1 and COX-2 inhibition assays. Moreover, in-vivo antitumor effect of vitex berries alcoholic and chloroform extracts were evaluated using Ehrlich ascites carcinoma model. Data were presented as mean±SE, and data were analyzed by one-way analysis of variance test. Results and conclusion: Berries crude extract showed potent antioxidant activity followed with its fractions ethyl acetate and chloroform as compared with standard (V.C and BHT). Ethyl acetate fraction showed good reduction capability, metal ion chelation, hydrogen peroxide scavenging, nitric oxide scavenging and superoxide anion scavenging. Meanwhile, chloroform fraction produced the highest free radical scavenging activity and total antioxidant capacity. In respectable of lipid peroxidation inhibition, crude alcoholic extract and its fractions cleared weak inhibition in comparing with standard materials. Anti-inflammatory activity of V. agnus-castus berries chloroform fraction of vitex was best COX-2 inhibitor (IC₅₀, 135.41 µg/ ml) as compared to vitex alcoholic extract or ethyl acetate fraction with weak inhibitory effect on COX-1 (IC50, 778.432 µg/ ml), where the lowest effect on COX-1 was recorded with alcoholic extract. Alcoholic extract and its fractions showed weak COX-1 inhibition activity, whereas COX-2 was inhibited (100%), compared with celecoxib drug (72% at 1000ppm). The crude alcoholic and chloroform extracts of V. agnus-castus barries significantly reduced the viable Ehrlich cell count and increased nonviable count with amelioration of all hematological parameters. This amelioration was reflected on increasing median survival time and significant increase (P < 0.05) in lifespan.

Keywords: anti-inflammatory, antioxidants, ehrlich ascites carcinoma, Vitex agnus-castus

Procedia PDF Downloads 121

Authors: Mukta Avachat-Shirke

Abstract:

The process of manifestation in art has been studied deeply by various Indian and Western philosophers through times. In the art of painting, ‘Practice’ is always considered as techniques or making and ‘Theory’ is related to intelligence or the ‘conceptual.' The question about the significance of ‘Practice’ in artistic research has been a topic of debate. The aim of this qualitative study is to find the relevance of practice and theory while creating artworks. This study analyzes the thoughts and philosophy of Abhinavgupta, Hegel, and Croce to find a new perspective for looking at practice and theory within artistic research. With the method of grounded theory, the study attempts to establish the importance of both in artistic research. It discusses the issues like stages of creating art, role of tacit knowledge and importance of the decision-making the ability of the artist. This comparative analysis of these three philosophers along with the present systems can be used as a point of reference for further developments in the pedagogy of art research and artists, to understand the psychology and to follow the process of creativity effectively.

Keywords: artistic research, Indian philosophy, practice, Western Philosophy

Procedia PDF Downloads 270

Authors: Paduri Veerabhadram, Antoinette Lombard

Abstract:

In this paper a framework for hypothesizing about mobile learning to complement theories of formal and informal learning is presented. As such, activity theory will form the main theoretical lens through which the elements involved in formal and informal learning for mobile learning will be explored, specifically related to context-aware mobile learning application. The author believes that the complexity of the relationships involved can best be analysed using activity theory. Activity theory, as a social, cultural and activity theory can be used as a mobile learning framework in an academic environment, but to develop an optimal artifact, through investigation of inherent system's contradictions. As such, it serves as a powerful modelling tool to explore and understand the design of a mobile learning environment in the study’s environment. The Academic Tool Kit Framework (ATKF) as also employed for designing of a constructivism learning environment, effective in assisting universities to facilitate lecturers to effectively implement learning through utilizing mobile devices. Results indicate a positive perspective of students in the use of mobile devices for formal and informal learning, based on the context-aware learning environment developed through the use of activity theory and ATKF.

Keywords: collaborative learning, cooperative learning, context-aware learning environment, mobile learning, pedagogy

Procedia PDF Downloads 532

Authors: Harald Lindorfer, Bettina Frauz, Dietmar Ramhold

Abstract:

Next to the well-known inhibitors in anaerobic digestion like ammonia, antibiotics or disinfectants, the number of process failures connected with mould growth in the feedstock increased significantly in the last years. It was assumed that mycotoxins are the cause of the negative effects. The financial damage to plants associated with these process failures is considerable. The aim of this study was to find a way of predicting the failures and furthermore strategies for a fast process recovery. In a first step, mould-contaminated feedstocks causing process failures in full-scale digesters were sampled and analysed on mycotoxin content. A selection of these samples was applied to biological inhibition tests. In this test, crystalline cellulose is applied in addition to the feedstock sample as standard substrate. Affected digesters were also sampled and analytical process data as well as operational data of the plants were recorded. Additionally, different mycotoxin substances, Deoxynivalenol, Zearalenon, Aflatoxin B1, Mycophenolic acid and Citrinin, were applied as pure substances to lab-scale digesters, individually and in various combinations, and effects were monitored. As expected, various mycotoxins were detected in all of the mould-contaminated samples. Nevertheless, inhibition effects were observed with only one of the collected samples, after applying it to an inhibition test. With this sample, the biogas yield of the standard substrate was reduced by approx. 20%. This result corresponds with observations made on full-scale plants. However, none of the tested mycotoxins applied as pure substance caused a negative effect on biogas production in lab scale digesters, neither after application as individual substance nor in combination. The recording of the process data in full-scale plants affected by process failures in most cases showed a severe accumulation of fatty acids alongside a decrease in biogas production and methane concentration. In the analytical data of the digester samples, a typical distribution of fatty acids with exceptionally high acetic acid concentrations could be identified. This typical fatty acid pattern can be used as a rapid identification parameter pointing to the cause of the process troubles and enable a fast implication of countermeasures. The results of the study show that more attention needs to be paid to feedstock storage and feedstock conservation before their application to anaerobic digesters. This is all the more important since first studies indicate that the occurrence of mycotoxins will likely increase in Europe due to the ongoing climate change.

Keywords: Anaerobic digestion, Biogas, Feedstock conservation, Fungal mycotoxins, Inhibition, process failure

Procedia PDF Downloads 103

Authors: Reena Murali, David Peter S.

Abstract:

The small interfering RNA (siRNA) alters the regulatory role of mRNA during gene expression by translational inhibition. Recent studies shows that up regulation of mRNA cause serious diseases like Cancer. So designing effective siRNA with good knockdown effects play an important role in gene silencing. Various siRNA design tools had been developed earlier. In this work, we are trying to analyze the existing good scoring second generation siRNA predicting tools and to optimize the efficiency of siRNA prediction by designing a computational model using Artificial Neural Network and whole stacking energy (ΔG), which may help in gene silencing and drug design in cancer therapy. Our model is trained and tested against a large data set of siRNA sequences. Validation of our results is done by finding correlation coefficient of experimental versus observed inhibition efficacy of siRNA. We achieved a correlation coefficient of 0.727 in our previous computational model and we could improve the correlation coefficient up to 0.753 when the threshold of whole tacking energy is greater than or equal to -32.5 kcal/mol.

Keywords: artificial neural network, double stranded RNA, RNA interference, short interfering RNA

Procedia PDF Downloads 507

Authors: Amin Behradfar

Abstract:

‎Tourism has a direct impact on the national revenue for all touristic countries. It creates work opportunities‎, ‎industries‎, ‎and several investments to serve and raise nations performance and cultures. ‎This paper is devoted to analyze dynamical behaviour of a four-dimensional non-linear tourism-based social-ecological system by using the codimension two bifurcation theory‎. ‎In fact we investigate the cusp bifurcation of that‎. ‎Implications of our mathematical results to the tourism‎ ‎industry are discussed‎. Moreover, profitability‎, ‎compatibility and sustainability of the tourism system are shown by the aid of cusp bifurcation and numerical techniques‎.

Keywords: tourism-based social-ecological dynamical systems, cusp bifurcation, center manifold theory, profitability, ‎compatibility, sustainability

Procedia PDF Downloads 480

Authors: Sabrina Boutaleb, Fouad Bourad, Kouider Halim Benrahou, Abdelouahed Tounsi

Abstract:

In the present work, the dynamic analysis of the functionally graded rectangular nanoplates is studied. The theory of nonlocal elasticity based on the quasi 3D high shear deformation theory (quasi 3D HSDT) has been employed to determine the natural frequencies of the nanosized FG plate. In HSDT, a cubic function is employed in terms of thickness coordinates to introduce the influence of transverse shear deformation and stretching thickness. The theory of nonlocal elasticity is utilized to examine the impact of the small scale on the natural frequency of the FG rectangular nanoplate. The equations of motion are deduced by implementing Hamilton’s principle. To demonstrate the accuracy of the proposed method, the calculated results in specific cases are compared and examined with available results in the literature, and a good agreement is observed. Finally, the influence of the various parameters, such as the nonlocal coefficient, the material indexes, the aspect ratio, and the thickness-to-length ratio, on the dynamic properties of the FG nanoplates is illustrated and discussed in detail.

Keywords: nonlocal elasticity theory, FG nanoplate, free vibration, refined theory, elastic foundation

Procedia PDF Downloads 93

Authors: Zhaoguo Liu, Cunsi Shen, Yin Lu

Abstract:

Growing evidence has shown that menthol has potent anticancer activity in various human cancers. However, its effect on skin cancer remains largely unknown. In the present study, we investigated the chemopreventive potential of menthol against 7, 12-dimethylbenz[a] anthracene(DMBA)/12-O-tetradecanoylphorbol 13-acetate (TPA)-induced skin tumorigenesis in ICR mice. Our results showed that menthol significantly inhibited TPA-induced inflammatory responses and pro-inflammatory cytokine release. We also found that menthol treatment significantly inhibited TPA-induced lipid peroxidation (LPO), mouse UDP-glucumno-syltransferase (UGT), mouse NADH Dehydrogenase, Quinone 1 (NQO1) release. Furthermore, we found menthol treatment significantly inhibited the tumor incidence and number of tumors (P < 0.001). Interestingly, we observed that menthol treatment significantly inhibited TPA-induced altered activity of NF-κB in skin tumor. Consistently, menthol-treated tumors also showed significantly suppressed the Ras-Raf-ERK signaling pathway. Thus, our results suggest that menthol inhibits DMBA/TPA-induced skin tumorigenesis by attenuating the Ras and inhibiting NF-κB activity via inhibition of inflammation responses and pro-inflammatory cytokine release.

Keywords: DMBA/TPA, NF-κB, Ras-Raf-ERK, skin tumorigenesis

Procedia PDF Downloads 287

Authors: Ogemdi Chinwendu Anika, Anna Strzelecka, Yadira Bajón-Fernández, Raffaella Villa

Abstract:

Anaerobic digestion (AD) has been used since time in memorial to take care of organic wastes in the environment, especially for sewage and wastewater treatments. Recently, the rising demand/need to increase renewable energy from organic matter has caused the AD substrates spectrum to expand and include a wider variety of organic materials such as agricultural residues and farm manure which is annually generated at around 140 billion metric tons globally. The problem, however, is that agricultural wastes are composed of materials that are heterogeneous and too difficult to degrade -particularly lignin, that make up about 0–40% of the total lignocellulose content. This study aimed to evaluate the impact of varying concentrations of lignin on biogas yields and their subsequent response to a commercial yeast-based bioadditive in batch anaerobic digesters. The experiments were carried out in batches for a retention time of 56 days with different lignin concentrations (200 mg, 300 mg, 400 mg, 500 mg, and 600 mg) treated to different conditions to first determine the concentration of the bioadditive that was most optimal for overall process improvement and yields increase. The batch experiments were set up using 130 mL bottles with a working volume of 60mL, maintained at 38°C in an incubator shaker (150rpm). Digestate obtained from a local plant operating at mesophilic conditions was used as the starting inoculum, and commercial kraft lignin was used as feedstock. Biogas measurements were carried out using the displacement method and were corrected to standard temperature and pressure using standard gas equations. Furthermore, the modified Gompertz equation model was used to non-linearly regress the resulting data to estimate gas production potential, production rates, and the duration of lag phases as indicatives of degrees of lignin inhibition. The results showed that lignin had a strong inhibitory effect on the AD process, and the higher the lignin concentration, the more the inhibition. Also, the modelling showed that the rates of gas production were influenced by the concentrations of the lignin substrate added to the system – the higher the lignin concentrations in mg (0, 200, 300, 400, 500, and 600) the lower the respective rate of gas production in ml/gVS.day (3.3, 2.2, 2.3, 1.6, 1.3, and 1.1), although the 300 mg increased by 0.1 ml/gVS.day over that of the 200 mg. The impact of the yeast-based bioaddition on the rate of production was most significant in the 400 mg and 500 mg as the rate was improved by 0.1 ml/gVS.day and 0.2 ml/gVS.day respectively. This indicates that agricultural residues with higher lignin content may be more responsive to inhibition alleviation by yeast-based bioadditive; therefore, further study on its application to the AD of agricultural residues of high lignin content will be the next step in this research.

Keywords: anaerobic digestion, renewable energy, lignin valorisation, biogas

Procedia PDF Downloads 64

Authors: Jing-Gang Xie

Abstract:

The research, in this case, considers the integration of the Quantum Field Theory and the General Relativity Theory. As two successful models in explaining behaviors of particles, they are incompatible since they work at different masses and scales of energy, with the evidence that regards the description of black holes and universe formation. It is so considering previous efforts in merging the two theories, including the likes of the String Theory, Quantum Gravity models, and others. In a bid to prove an actionable experiment, the paper’s approach starts with the derivations of the existing theories at present. It goes on to test the derivations by applying the same initial assumptions, coupled with several deviations. The resulting equations get similar results to those of classical Newton model, quantum mechanics, and general relativity as long as conditions are normal. However, outcomes are different when conditions are extreme, specifically with no breakdowns even for less than Schwarzschild radius, or at Planck length cases. Even so, it proves the possibilities of integrating the two theories.

Keywords: general relativity theory, particles, photons, Quantum Gravity Model, gravitational frequency shift

Procedia PDF Downloads 336

Authors: Nagarjuna Remalli, Robert Brandt

Abstract:

Down-sizing of combustion engines in automobiles are prevailed owing to required increase in efficiency. This leads to a stress increment on valve springs, which affects their intended function due to an increase in relaxation. High strength martensitic steels are used for valve spring applications. Recent investigations unveiled that low temperature creep (LTC) in martensitic steels obey a logarithmic creep law. The exhaustion theory links the logarithmic creep behavior to an activation energy which is characteristic for any given time during creep. This activation energy increases with creep strain due to barriers of low activation energies exhausted during creep. The assumption of the exhaustion theory is that the material is inhomogeneous in microscopic scale. According to these assumptions it is anticipated that small obstacles (e. g. ε–carbides) having a wide range of size distribution are non-uniformly distributed in the materials. X-ray diffraction studies revealed the presence of ε–carbides in high strength martensitic steels. In this study, high strength martensitic steels that are crept in the temperature range of 75 – 150 °C were investigated with the aid of a transmission electron microscope for the evidence of an inhomogeneous distribution of obstacles having different size to examine the validation of exhaustion theory.

Keywords: creep mechanisms, exhaustion theory, low temperature creep, martensitic steels

Procedia PDF Downloads 238

Authors: Abdelhafez Abdel Hafez

Abstract:

Dependency theory was developed since 1950s, with economic concerns. It divided the world into two parts, the states of the peripheral (third world countries) and the states of the core (the developed capitalist countries). Another perspective developed to the theory with the implementation of the idea of semi-peripheral states in the new world order. With these divisions (core, peripheral, semi-peripheral) this study aims to develop a concept from the perspective of dependency theory, to understand the nature of the relationship of the U.S. with the Middle East Regions through its relation with Iran, Saudi Arabia, and Turkey. The tested countries (Saudi Arabia, Iran and Turkey) are seeking a foothold and influential role in the region. The paper argued that the U.S. directs its policies toward the region, in the way to guarantee no country of the region will be in semi-peripheral level (that could create competitions or danger on the U.S. interest). Therefore, U.S. policies in the region have varied from declaring war to diplomatic channels and sometimes ignoring. The paper is based on the dependency theory, and other international relations theories used to study the Middle East in the international context.

Keywords: dependency, hegemony, imperialism, middle east

Procedia PDF Downloads 98

Authors: Abdul Matin, Muazzama Akhtar, Shahid Nisar, Saddaf Mazzar, Umer Rashid

Abstract:

Antibiotic resistance is an increasing concern worldwide now a day. Neisseria gonorrhea and Staphylococcus aureus are known to cause major human sexually transmitted and respiratory diseases respectively. Nanotechnology is an emerging discipline and its application in various fields especially in medical sciences is gigantic. In the present study, we synthesized multi-walled carbon nanotubes (MWNTs) using acid oxidation method and solubilized MWNTs were with length predominantly >500 nm and diameters ranging from 40 to 50 nm. The locally synthesized MWNTs were used against gram positive and negative bacteria to determine their impact on bacterial growth. Clinical isolates of Neisseria gonorrhea (isolate: 4C-11) and Staphylococcus aureus (isolate: 38541) were obtained from local hospital and normally cultured in LB broth at 37°C. Both clinical strains can be obtained on request from University of Gujarat. Spectophometric assay was performed to determine the impact of MWNTs on bacterial growth in vitro. To determine the effect of MWTNs on test organisms, various concentration of MWNTs were used and recorded observation on various time intervals to understand the growth inhibition pattern. Our results demonstrated that MWNTs exhibited toxic effects to Staphylococcus aureus while showed very limited growth inhibition to Neisseria gonorrhea, which suggests the resistant potential of Neisseria against nanoparticles. Our results clearly demonstrate the gradual decrease in bacterial numbers with passage of time when compared with control. Maximum bacterial inhibition was observed at maximum concentration (50 µg/ml). Our future work will include further characterization and mode of action of our locally synthesized MWNTs. In conclusion, we investigated and reported for the first time the inhibitory potential of locally synthesized MWNTs on local clinical isolates of Staphylococcus aureus and Neisseria gonorrhea.

Keywords: antibacterial activity, multi walled carbon nanotubes, Neisseria gonorrhea, spectrophotometer assay, Staphylococcus aureus

Procedia PDF Downloads 290

Authors: Roberto Cassino, Valeria Dissette, Carlo Alberto Bignozzi, Daniele Pazzi

Abstract:

Background and Aims: The aim of this work was to investigate, both ‘in vitro’ and ‘in vivo’, if the new SCX technology (SiO2-Ag+Chlorex) can easily defeat infections and it is really more effective than SSD (SilverSulfaDiazine). ‘In vitro’ methods: we tested ‘in vitro’ the effectiveness of both silver materials using a pool of 5 strains: Pseudomonas Aeruginosa, Staphylococcus aureus, Escherichia Coli, Enterococcus hirae and Candida Albicans. 100 µl of this pool have been seeded on Petri dishes and kept for 24 hours in incubation at 37 C°. ‘In vivo’ methods: we enrolled patients with multiple infectious chronic wounds (according with cutting & harding criteria for infection); after a qualitative evaluation of the wounds bacterial population, taking a sample by plug, we included in the study 6 patients for a total of 10 wounds, infected by one or more of the microorganisms used for the ‘in vitro’ test. The protocol consisted of a treatment with a spray powder of SSD every 48 hours for 14 days; in case of worsening we should have to start a new treatment with a spray powder containing silicon dioxide, ionic silver and chlorexidine (SiO2-Ag+Chlorex) every 48 hours for 14 days. We evaluated the number of clinical signs of infection and the disappearance or not of the wound edge erithema. ‘In vitro’ results: SSD demonstrated a wide zone of inhibition within 24 hours, but after 5 days there was no more signs of inhibition; on the contrary SCX had a good inhibition ring that lasted more than 5 days. ‘In vivo’ results: all wounds treated with SSD got worse; the signs of infection increased and the wound edge erithema did not disappear. According with the protocol, we treated then all wounds with SCX and they all improved within the period of observation with complete disappearance of clinical signs of infection and no more wound edge erithema. Conclusions: the study demonstrated the effectiveness of SiO2-Ag+Chlorex, especially in terms of long lasting antimicrobial action. We had the same results ‘in vitro’, so that there has been a perfect correspondence between the laboratory outcomes and the clinical ones.

Keywords: chronic wounds, infections, ionic silver, SSD

Procedia PDF Downloads 295

Authors: Oseyemi Omowunmi Olubomehin, Olufemi Michael Denton

Abstract:

Diabetes mellitus is a disease that is related to the digestion of carbohydrates, proteins and fats and how this affects the blood glucose levels. Various synthetic drugs employed in the management of the disease work through different mechanisms. Keeping postprandial blood glucose levels within acceptable range is a major factor in the management of type 2 diabetes and its complications. Thus, the inhibition of carbohydrate-hydrolyzing enzymes such as α-amylase is an important strategy in lowering postprandial blood glucose levels, but synthetic inhibitors have undesirable side effects like flatulence, diarrhea, gastrointestinal disorders to mention a few. Therefore, it is necessary to identify and explore the α-amylase inhibitors from plants due to their availability, safety, and low costs. In the present study, extracts from the leaves of Rauvolfia vomitoria and seeds of Picralima nitida which are used in the Nigeria traditional system of medicine to treat diabetes were tested for their α-amylase inhibitory effect. The powdered plant samples were subjected to phytochemical screening using standard procedures. The leaves and seeds macerated successively using n-hexane, ethyl acetate and methanol resulted in the crude extracts which at different concentrations (0.1, 0.5 and 1 mg/mL) alongside the standard drug acarbose, were subjected to α-amylase inhibitory assay using the Benfield and Miller methods, with slight modification. Statistical analysis was done using ANOVA, SPSS version 2.0. The phytochemical screening results of the leaves of Rauvolfia vomitoria and the seeds of Picralima nitida showed the presence of alkaloids, tannins, saponins and cardiac glycosides while in addition Rauvolfia vomitoria had phenols and Picralima nitida had terpenoids. The α-amylase assay results revealed that at 1 mg/mL the methanol, hexane, and ethyl acetate extracts of the leaves of Rauvolfia vomitoria gave (15.74, 23.13 and 26.36 %) α-amylase inhibitions respectively, the seeds of Picralima nitida gave (15.50, 30.68, 36.72 %) inhibitions which were not significantly different from the control at p < 0.05, while acarbose gave a significant 56 % inhibition at p < 0.05. The presence of alkaloids, phenols, tannins, steroids, saponins, cardiac glycosides and terpenoids in these plants are responsible for the observed anti-diabetic activity. However, the low percentages of α-amylase inhibition by these plant samples shows that α-amylase inhibition is not the major way by which both plants exhibit their anti-diabetic effect.

Keywords: alpha-amylase, Picralima nitida, postprandial hyperglycemia, Rauvolfia vomitoria

Procedia PDF Downloads 160

Authors: Alok Kumar Yadav, Saurabh Saraswat, Preeti Sirohi, Manjoo Rani, Sameer Srivastava, Manish Pratap Singh, Nand K. Singh

Abstract:

The development of antibiotic resistance in bacteria is increasing at an alarming rate, and this is considered as one of the most serious threats in the history of medicine, and an alternative solution should be derived so as to tackle this problem. In many countries, people use the medicinal plants for the treatment of various diseases as these are cheaper, easily available and least toxic. Syzygium cumini is used for the treatment of various kinds of diseases but their mechanism of action is not reported. The antimicrobial activity of Syzygium cumini was tested by the well diffusion assay and zone of inhibition was reported to be 20.06 mm as compared to control with MIC of 0.3 mg/ml. Genomic DNA fragmentation of Bacillus subtilis revealed apoptosis and FE-SEM indicate cell wall cracking on several intervals of time. Propidium iodide staining results showed that few bacterial cells were stained in the control and population of stained cells increase after exposing them for various period of time. Flow cytometric kinetic data analysis on the membrane permeabilization in bacterial cell showed the significant contribution of antimicrobial potential of the seed extract on antimicrobial-induced permeabilization. Two components of Syzygium cumini methanolic seed extract was found to be quite active against four enzymes like PDB ID- 1W5D, 4OX3, 3MFD and 5E2F which have a very crucial role in membrane synthesis in Bacillus subtilis by in silico analysis. Through in silico analysis, lupeol showed highest binding energy for macromolecule 1W5D and 4OX3 whereas stigmasterol showed the highest binding energy for macromolecule 3MFD and 5E2F respectively. It showed that methanolic seed extract of Syzygium cumini can be used for the inhibition of foodborne infections caused by Bacillus subtilis and also as an alternative of prevalent antibiotics.

Keywords: antibiotics, Bacillus subtilis, inhibition, Syzygium cumini

Procedia PDF Downloads 171

Authors: Hammad Khan, Wookeun Bae

Abstract:

The objective of this study was to optimize and control the highly loaded and efficient nitrite production having suitability for autotrophic and heterotrophic denitritation. A lab scale CSTR for partial and full nitritation was operated to treat the livestock manure digester liquor having an ammonium concentration of ~600 mg-NH4+-N/L and biodegradable contents of ~0.35 g-COD/L. The experiments were performed at 30°C, pH: 8.0, DO: 1.5 mg/L and SRT ranging from 7-20 days. After 125 days operation, >95% nitrite buildup having the ammonium loading rate of ~3.2 kg-NH4+-N/m3-day was seen with almost complete ammonium conversion. On increasing the loading rate further (i-e, from 3.2-6.2 kg-NH4+-N/m3-day), stability of the system remained unaffected. On decreasing the pH from 8 to 7.5 and further 7.2, removal rate can be easily controlled as 95%, 75%, and even 50%. Results demonstrated that nitritation stability and desired removal rates are controlled by a balance of simultaneous inhibition by FA & FNA, pH effect and DO limitation. These parameters proved to be effective even to produce an appropriate influent for anammox. In addition, a mathematical model, identified through the occurring biological reactions, is proposed to optimize the full and partial nitritation process. The proposed model present relationship between pH, ammonium and produced nitrite for full and partial nitritation under the varying concentrations of DO, and simultaneous inhibition by FA and FNA.

Keywords: stable nitritation, high loading, autrophic denitritation, hetrotrophic denitritation

Procedia PDF Downloads 287

Authors: Hammad Khan, Wookeun Bae

Abstract:

The objective of this study was to optimize, achieve and control the highly loaded and efficient nitrite production having suitability for autotrophic and heterotrophic denitritation. A lab scale CSTR for partial and full nitritation was operated to treat the livestock manure digester liquor having an ammonium concentration of ~600 mg-NH4+-N/L and biodegradable contents of ~0.35 g-COD/L. The experiments were performed at 30°C, pH: 8.0, DO: 1.5 mg/L and SRT ranging from 7-20 days. After 125 days operation, >95% nitrite buildup having the ammonium loading rate of ~3.2 kg-NH4+-N/m3-day was seen with almost complete ammonium conversion. On increasing the loading rate further (i-e, from 3.2-6.2 kg-NH4+-N/m3-day), stability of the system remained unaffected. On decreasing the pH from 8 to7.5 and further 7.2, removal rate can be easily controlled as 95%, 75%, and even 50%. Results demonstrated that nitritation stability and desired removal rates are controlled by a balance of simultaneous inhibition by FA & FNA, pH affect and DO limitation. These parameters proved to be effective even to produce an appropriate influent for anammox. In addition, a mathematical model, identified through the occurring biological reactions, is proposed to optimize the full and partial nitritation process. The proposed model present relationship between pH, ammonium and produced nitrite for full and partial nitritation under the varying concentrations of DO, and simultaneous inhibition by FA and FNA.

Keywords: stable nitritation, high loading, autrophic denitritation, CSTR

Procedia PDF Downloads 211

Authors: Po-Sheng Kuo, Che-Wei Lu, Ssu-Ching Chen

Abstract:

Chlorinated ethenes (CEs) constitute a predominant contaminant in Taiwan's native polluted sites, particularly in groundwater inundated with sulfate salts that substantially impede remediation efforts. The reduction of sulfate by sulfate-reducing bacteria (SRB) impairs the dechlorination efficiency of Dehalococcoides by generating hydrogen sulfide (H₂S), resulting in incomplete chloride degradation and thereby leading to the failure of bioremediation. In order to elucidate interactions between sulfate reduction and dechlorination, this study aims to establish a co-culture system of Dehalococcoides and SRB, overcoming H₂S inhibition by employing the synthesis of ferrous sulfide (FeS), which is commonly utilized in chemical remediation due to its high reduction potential. Initially, the study demonstrates that the addition of ferrous chloride (FeCl₂) effectively removed H₂S production from SRB and enhanced the degradation of trichloroethylene to ethene. This process overcomes the inhibition caused by H₂S produced by SRB in high sulfate environments. Compared to different concentrations of ferrous dosages for the biogenic generation of FeS, the efficiency was optimized by adding FeCl₂ at an equal ratio to the concentration of sulfate in the environment. This was more effective in removing H₂S and crystal particles under 10 times smaller than those synthesized under excessive FeCl₂ dosages, addressing clogging issues in situ remediation. Finally, utilizing Taiwan's indigenous dechlorinating consortium in a simulated high sulfate-contaminated environment, the biodiversity of microbial species was analyzed to reveal a higher species richness within the FeS group, conducive to ecological stability. This study validates the potential of the co-culture system in generating biogenic FeS under sulfate and CEs co-contamination, removing sulfate-reducing products, and improving CE remediation through integrated chemical and biological remediations.

Keywords: biogenic ferrous sulfide, chlorinated ethenes, Dehalococcoides, sulfate-reducing bacteria, sulfide inhibition

Procedia PDF Downloads 30

Authors: Seyedeh Khadijeh. Mirbazel, Masoumeh Arjmandi

Abstract:

Semantics is a linguistic approach and a scientific stream, and like all scientific streams, it is dynamic. The study of meaning is carried out in the broad semantic collections of words that form the discourse. In other words, meaning is not something that can be found in a word; rather, the formation of meaning is a process that takes place in a discourse as a whole. One of the contemporary semantic theories is Izutsu's Semantic Field Theory. According to this theory, the discovery of meaning depends on the function of words and takes place within the context of language. The purpose of this research is to identify the meaning of the word "Nas" in the discourse of verse 24 of Surah Al-Baqarah, which introduces "Nas" as the firewood of hell, but the translators have translated it as "people". The present research has investigated the semantic structure of the word "Nas" using the aforementioned theory through the descriptive-analytical method. In the process of investigation, by matching the semantic fields of the Quranic word "Nas", this research came to the conclusion that "Nas" implies those persons who have forgotten God and His covenant in believing in His Oneness. For this reason, God called them "Nas (the forgetful)" - the imperfect participle of the noun /næsiwoɔn/ in single trinity of Arabic language, which means “to forget”. Therefore, the intended meaning of "Nas" in the verses that have the word "Nas" is not equivalent to "People" which is a general noun.

Keywords: Nas, people, semantics, semantic field theory.

Procedia PDF Downloads 164

Authors: Constance Chivengwa, Tinashe Mandimutsira, Jephris Gere, Charles Magogo, Irene Chikanza, Jerneja Vidmar, Walter Chingwaru

Abstract:

The use of traditional methods in the management of diarrhoea has remained a common practice among the indigenous African tribes of Southern Africa. Despite the widespread use of traditional medicines in Zimbabwe, very little research validating the activities of phytomedicines against diarrhoea, as claimed by the Shona people of Zimbabwe, has been reported. This study sought to determine the efficacies of the plants that are frequently used to treat stomach complaints, namely Dicoma anomala, Cassia abbreviata, Lannea edulis and Peltophorum africanum against Escherichia coli (an indicator of faecal contamination of water, and whose strains such as EHEC (O157), ETEC and EPEC, are responsible for a number of outbreaks of diarrhoea) and Salmonella spp. Ethanol and aqueous extracts from these plants were obtained, evaporated, dried and stored. The dried extracts were reconstituted and diluted 10-fold in nutrient broth (from 100 to 0.1 microgram/mL) and tested for inhibition against the bacteria. L. edulis exhibited the best antimicrobial effect (minimum inhibition concentration = 10 microgram/mL for both extracts and microorganisms). Runners up to L. edulis were C. abbreviata (20 microgram/mL for both microorganisms) and P. africanum (20 and 30 microgram/mL respectively). Interestingly, D. anomala, which is widely considered panacea in African medicinal practices, showed low antimicrobial activity (60 and 100 microgram/mL respectively). The high antimicrobial activity of L. edulis can be explained by its content of flavonoids, tannins, alkylphenols (cardonol 7 and cardonol 13) and dihydroalkylhexenones. The antimicrobial activities of C. abbreviata can be linked to its content of anthraquinones and triterpenoids. P. africanum is known to contain benzenoids, flavanols, flavonols, terpenes, xanthone and coumarins. This study therefore demonstrated that, among the plants that are used against diarrhoea in African traditional medicine, L. edulis is a clear winner against E. coli and Salmonella spp. Activity guided extraction is encouraged to establish the complement of compounds that have antimicrobial activities.

Keywords: diarrhoea, Escherichia coli, Salmonella, phytomedicine, MIC, Zimbabwe

Procedia PDF Downloads 344

Authors: Iftikhar U. Sikder

Abstract:

This paper illustrates an application of granular computing approach, namely rough set theory in data mining. The paper outlines the formalism of granular computing and elucidates the mathematical underpinning of rough set theory, which has been widely used by the data mining and the machine learning community. A real-world application is illustrated, and the classification performance is compared with other contending machine learning algorithms. The predictive performance of the rough set rule induction model shows comparative success with respect to other contending algorithms.

Keywords: concept approximation, granular computing, reducts, rough set theory, rule induction

Procedia PDF Downloads 500