Search results for: antimicrobial activity

Authors: Zahra Azizi, Ashkan Karbasi, Farzin Firouzian, Sara Soleimani Asl, Akram Ranjbar

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Background: One of the most often used herbicides in agriculture is paraquat (PQ), which is very harmful to both people and animals. Chitosan is a well-known, non-toxic polymer commonly used in preparing particles via ionotropic gelation facilitated by negatively charged agents such as sodium alginate. This study aimed to compare the effects of PQ and nanoparaquat (PQNPs) on liver function in male rats. Materials & Methods: Rats were exposed to PQ & PQNPs (4 mg/kg/day, intraperitoneally) for seven days. Then, rats were anesthetized, and serum and liver samples were collected. Later, enzymatic activities such as alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP) in serum and oxidative stress biomarkers such as lipid peroxidation (LPO), total antioxidant capacity (TAC) and total thiol groups (TTG) levels in liver tissue were measured by colorimetric methods. Also, histological changes in the liver were evaluated. Results: PQ altered the levels of ALT, AST, and ALP while inducing oxidative stress in the liver. Additionally, liver homogenates with PQ exposure had challenged LPO, TAC, and TTG levels. The severe liver damage is indicated by a significant increase in the enzyme activity of AST, ALT, and ALP in serum. According to the results of the current study, PQNPs, as compared to PQ and the control group, lowered ALT, AST, ALP, and LPO levels while increasing TAC and TTG levels. Conclusion: According to biochemical and histological investigations, PQ loaded in chitosan-alginate particles is more efficient than free PQ at reducing liver toxicity.

Keywords: paraquat, paraquat nanoparticles, liver, oxidative stress

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Authors: Muhammad H. Alu’datt, Inteaz Alli

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This study was conducted to prepare and evaluate the biological properties of protein co-precipitates from flaxseed and soybean. Protein was prepared by NaOH extraction through the mixing of soybean flour (Sf) and flaxseed flour (Ff) or mixtures of soybean extract (Se) and flaxseed extract (Fe). The protein co-precipitates were precipitated by isoelectric (IEP) and isoelectric-heating (IEPH) co-precipitation techniques. Effects of extraction and co-precipitation techniques on co-precipitate yield were investigated. Native-PAGE, SDS-PAGE were used to study the molecular characterization. Content and antioxidant activity of extracted free and bound phenolic compounds were evaluated for protein co-precipitates. Removal of free and bound phenolic compounds from protein co-precipitates showed little effects on the electrophoretic behavior of the proteins or the protein subunits of protein co-precipitates. Results showed that he highest protein contents and yield were obtained in for Sf-Ff/IEP co-precipitate with values of 53.28 and 25.58% respectively as compared to protein isolates and other co-precipitates. Results revealed that the Sf-Ff/IEP showed a higher content of bound phenolic compounds (53.49% from total phenolic content) as compared to free phenolic compounds (46.51% from total phenolic content). Antioxidant activities of extracted bound phenolic compounds with and without heat treatment from Sf-Ff/IEHP were higher as compared to free phenolic compounds extracted from other protein co-precipitates (29.68 and 22.84%, respectively).

Keywords: antioxidant, phenol, protein co-precipitate, yield

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Authors: Araceli Martinez Ortiz, Gillian Bayne, Solomon Abraham

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This paper describes research led by faculty from three American universities and four Ethiopian universities on the delivery of professional leadership development for early-career female Ethiopian university instructors in the Science, Technology, Engineering, and Mathematics (STEM) fields. The objective was to carry out a case study focused on the impact of an innovative intervention program designed to assist in the empowerment and leadership development related to teaching effectiveness, scholarly activity participation, and professional service participation by female instructors. This research was conducted utilizing a case study methodology for the weeklong intervention and a survey to capture the voices of the leadership program participants. The data regarding insights into the challenges and opportunities for women in these fields is presented. The research effort project expands upon existing linkages between universities to support professional development and research effort in this region of the world. Findings indicate the positive reception of this kind of professional development by the participating women. Survey data also reflects the particular cultural challenges professional women in STEM education face in Ethiopia as well as the global challenges of balancing family expectations with career development.

Keywords: Ethiopian women, STEM leadership, professional development, gender equity

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Authors: Malgorzata J. Rybak-Smith, Benedicte Thiebaut, Simon Johnson, Peter Bishop, Helen E. Townley

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Gadolinium doped titania (TiO2:Gd) nanoparticles (NPs) can be activated by X-ray radiation to generate Reactive Oxygen Species (ROS), which can be effective in killing cancer cells. As such, treatment with these NPs can be used to enhance the efficacy of conventional radiotherapy. Incorporation of the NPs in to tumour tissue will permit the extension of radiotherapy to currently untreatable tumours deep within the body, and also reduce damage to neighbouring healthy cells. In an attempt to find a fast and scalable method for the synthesis of the TiO2:Gd NPs, the use of Flame Spray Pyrolysis (FSP) was investigated. A series of TiO2 NPs were generated with 1, 2, 5 and 7 mol% gadolinium dopant. Post-synthesis, the TiO2:Gd NPs were silica-coated to improve their biocompatibility. Physico-chemical characterisation was used to determine the size and stability in aqueous suspensions of the NPs. All analysed TiO2:Gd NPs were shown to have relatively high photocatalytic activity. Furthermore, the FSP synthesized silica-coated TiO2:Gd NPs generated enhanced ROS in chemico. Studies on rhabdomyosarcoma (RMS) cell lines (RD & RH30) demonstrated that in the absence of irradiation all TiO2:Gd NPs were inert. However, application of TiO2:Gd NPs to RMS cells, followed by irradiation, showed a significant decrease in cell proliferation. Consequently, our studies showed that the X-ray-activatable TiO2:Gd NPs can be prepared by a high-throughput scalable technique to provide a novel and affordable anticancer therapy.

Keywords: cancer, gadolinium, ROS, titania nanoparticles, X-ray

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Authors: Y. T. Gebreslassie, Abrha Tadesse, R. C. Saini, Rishi Pal

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Caffeine, known chemically as 3,7-dihydro-1,3,7-trimethyl-1H-purine-2,6-dione, is a naturally occurring alkaloid classified as an N-methyl derivative of xanthine. Given its widespread use in coffee and other caffeine-containing products, it is the most commonly consumed psychoactive substance in everyday human life. This research aimed to develop a cost-effective, sensitive, and easily manufacturable sensor for the detection of caffeine. Antraquinone-modified carbon paste electrode (AQMCPE) was fabricated, and the electrochemical behavior of caffeine on this electrode was investigated using cyclic voltammetry (CV) and square wave voltammetry (SWV) in a solution of 0.1M perchloric acid at pH 0.56. The modified electrode displayed enhanced electrocatalytic activity towards caffeine oxidation, exhibiting a two-fold increase in peak current and an 82 mV shift of the peak potential in the negative direction compared to an unmodified carbon paste electrode (UMCPE). Exploiting the electrocatalytic properties of the modified electrode, SWV was employed for the quantitative determination of caffeine. Under optimized experimental conditions, a linear relationship between peak current and concentration was observed within the range of 2.0 x 10⁻⁶ to 1.0× 10⁻⁴ M, with a correlation coefficient of 0.998 and a detection limit of 1.47× 10⁻⁷ M (signal-to-noise ratio = 3). Finally, the proposed method was successfully applied to the quantitative analysis of caffeine in pharmaceutical formulations, yielding recovery percentages ranging from 95.27% to 106.75%.

Keywords: antraquinone-modified carbon paste electrode, caffeine, detection, electrochemical sensor, quantitative analysis

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Authors: Yu Wen Wang, Shyh Ming Kuo, Hsia Ying Cheng, Yu Chiuan Wu

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Liver fibrosis is caused by the activation of hepatic stellate cells in the liver to secrete excessive and deposition of extracellular matrix. In recent years, many treatment strategies have been developed to reduce the activation of hepatic stellate cells and therefore to increase the decomposition of extracellular matrix. Bacopa monnieri, an herbaceous plant of the scrophulariaceae, containing saponins and glycosides, which with antioxidant, anti-inflammation, pain relief and free radical scavenging characteristics. This study was to evaluate the inhibition of hepatic stellate cell activity by Bacopa monnieri extract and its therapeutic potential in treating thioacetamide-induced liver fibrosis in rats. The results showed that the IC50 of Bacopa monnieri extract was 0.39 mg/mL. Bacopa monnieri extract could effectively reduce H2O2-induced hepatic stellate cells inflammation. In the TAA-induced liver fibrosis animal studies, albumin secretion recovered to normal level after treated with Bacopa monnieri extract for 2-w, and fibrosis related proteins, α-SMA and TGF-1levels decreased indicating the extract exerted therapeutic effect on the liver fibrosis. However, inflammatory factors TNF- obviously decreased after 4-w treatment. In summary, we could successfully extract the main component-Bacopaside I from the plant and acquired a potential therapy using this component in treating TAA-induced liver fibrosis in rat.

Keywords: anti-inflammatory, Bacopa monnieri, fibrosis, hepatic stellate cells, water extract

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Authors: A. Novikova, L. Rocchi, G. Startiene

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Market and non-market outputs are produced jointly in agriculture. Their supply depends on the intensity and type of production. The role of agriculture as an economic activity and its effects are important for the Lithuanian case study, as agricultural land covers more than a half of country. Positive and negative externalities, created in agriculture are not considered in the market. Therefore, specific techniques such as stated preferences methods, in particular choice experiments (CE) are used for evaluation of non-market outputs in agriculture. The main aim of this paper is to present construction of the research path for evaluation of non-market farming system outputs in Lithuania. The conventional and organic farming, covering crops (including both cereal and industrial crops) and livestock (including dairy and cattle) production has been selected. The CE method and nested logit (NL) model were selected as appropriate for evaluation of non-market outputs of different farming systems in Lithuania. A pilot survey was implemented between October–November 2018, in order to test and improve the CE questionnaire. The results of the survey showed that the questionnaire is accepted and well understood by the respondents. The econometric modelling showed that the selected NL model could be used for the main survey. The understanding of the differences between organic and conventional farming by residents was identified. It was revealed that they are more willing to choose organic farming in comparison to conventional farming.

Keywords: choice experiments, farming system, Lithuania market outputs, non-market outputs

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Authors: Mahshid Rezaei, Zahra Tajari, Zahra Esmaeily, Atefeh Eyvazkhani, Shahrzad Daei, Marjan Mansouri Dara, Mohaddesh Rezaei, Abolghassem Djazayeri, Ahmadreza Dorosti Motlagh

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Background: Musculoskeletal pain is one of the most prevalent symptoms in elderly age. Nutrition and diet are considered important underlying factors that could affect chronic musculoskeletal pain. The purpose of this study was to identify the relationship between empirical dietary inflammatory patterns (EDII) and musculoskeletal pain. Method: In this cross-sectional study, 213 elderly individuals were selected from several health centers. The usual dietary intake was evaluated by a valid and reliable 147-items food frequency questionnaire (FFQ). To measure the intensity of pain, Visual Analogue Scale (VAS) was used. Multiple Linear Regression was applied to assess the association between EDII and musculoskeletal pain. Results: The results of multiple linear regression analysis indicate that a higher EDII score was associated with higher musculoskeletal pain (β= 0.21: 95% CI: 0.24-1.87: P= 0.003). These results stayed significant even after adjusting for covariates such as sex, marital status, height, family number, sleep, BMI, physical activity duration, waist circumference, protector, and medication use (β= 0.16: 95% CI: 0.11-1.04: P= 0.02). Conclusion: Study findings indicated that higher inflammation of diet might have a direct association with musculoskeletal pains in elderlies. However, further investigations are required to confirm these findings.

Keywords: musculoskeletal pain, empirical dietary inflammatory pattern, elderlies, dietary pattern

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Authors: Gamalath M. B. P. Abeysekara

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Primary objective of any organization is to enhance the bottom line profit. Strategic procurement is one of the prominent aspects in view of receiving this ultimate objective. Strategic procurement is an activity used in each and every organization in their operations. Pharmaceutical procurement is an especially significant task for any organizations, particularly state sector concerned. The whole pharmaceutical procurement requirement of the country is procured through the State Pharmaceutical Corporation (SPC) of Sri Lanka. They follow Pharmaceutical Procurement Guideline of 2006 as the procurement principle. The main objective of this project is to identify the importance of State Pharmaceutical Corporation supplier selection criteria and critical analysis of pharmaceutical procurement procedure. State Pharmaceutical Corporations applied net price, product quality, past performance, and delivery of suppliers’ as main criteria for the selection suppliers. Data collection for this study was taken place through a questionnaire, given to fifty doctors within the Colombo district attached to five main state hospitals. Data analysis is carried out with mean and standard deviation functions. The ultimate outcomes indicated product quality, net price, and delivery of suppliers’ are the most important criteria behind the selection of suppliers. Critical analysis proved State Pharmaceutical Corporation should focus on net price reduction, improving laboratory testing facilities and effective communication between up and down stream of supply chain.

Keywords: government procurement procedure, pharmaceutical procurement supplier selection criteria, importance of SPC supplier selection criteria

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Authors: Maria Kazantzaki, Evangelos Tsakalos, Eleni Filippaki, Yannis Bassiakos

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Mediterranean areas are characterized by intense seismic and volcanic activity as well as eustatic changes, the result of which is the creation of particularly vulnerable coastal zones. The most vulnerable are low-lying coastal areas, the geomorphological evolution of which are highly affected by natural processes and anthropogenic interventions. Therefore, assessing changes that take place along coastal zones is of great importance in order to enable the development of integrated coastal management plans. A characteristic case is the gulf of Mirabello in N.E Crete, where intense coastal erosion, in combination with the tectonic subsidence of the area, threatens a large part of the coastal zone, resulting in direct socio-economic impacts. The present study assesses the temporal geomorphological changes that have taken place in the coastal zone of Mirabello gulf to provide a clear frame of the coastal zone evolution over time and performs a vulnerability assessment based on the coastal vulnerability index (CVI) methodology by Thieler and Hammar-Klose, considering geological features, coastal slope, relative sea-level change, shoreline erosion/accretion rates and mean significant wave height as well as mean tide range in the area. In light of this, an impact assessment, based on three different sea level rise scenarios, is also performed and presented.

Keywords: coastal vulnerability index, coastal erosion, GIS, sea level rise

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Authors: Jalil Qoulizadeh, Hasan Sadeghi

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Brain waves are electrical wave patterns that are produced in the human brain. Knowing these waves and activating them can have a positive effect on brain function and ultimately create an ideal life. The brain has the ability to produce waves from 0.1 to above 65 Hz. (The Beta One device produces exactly these waves) This is because it is said that the waves produced by the Beta One device exactly match the waves produced by the brain. The function and method of this device is based on the magnetic stimulation of the brain. The technology used in the design and producƟon of this device works in a way to strengthen and improve the frequencies of brain waves with a pre-defined algorithm according to the type of requested function, so that the person can access the expected functions in life activities. to perform better. The effect of this field on neurons and their stimulation: In order to evaluate the effect of this field created by the device, on the neurons, the main tests are by conducting electroencephalography before and after stimulation and comparing these two baselines by qEEG or quantitative electroencephalography method using paired t-test in 39 subjects. It confirms the significant effect of this field on the change of electrical activity recorded after 30 minutes of stimulation in all subjects. The Beta One device is able to induce the appropriate pattern of the expected functions in a soft and effective way to the brain in a healthy and effective way (exactly in accordance with the harmony of brain waves), the process of brain activities first to a normal state and then to a powerful one. Production of inexpensive neuroscience equipment (compared to existing rTMS equipment) Magnetic brain stimulation for clinics - homes - factories and companies - professional sports clubs.

Keywords: stimulation, brain, waves, betaOne

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Authors: Saifullah K., Muhammad Naziruddin Saifullah, Muhammad N.

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The bio control potential and mechanism of P. chlamydosporia against Meloidogyne incognita was evaluated in the present study. Under invitro conditions, P. chlamydosporia was tested for parasitism of eggs and females of M. incognita. The results indicated that this fungus parasitized 87% eggs and 82% females. Culture filtrate (CF) of P. chlamydosporia was tested for its larvicide activity against M. incognita 2nd stage juvenile. The maximum mortality was 97.3% at 100% concentration of the culture filtrate while minimum mortality was 7.3% in 25% concentration after 24 hrs. The result of the pot experiment proved that P. chlamydosporia has reduced the incidence of RKN and improved all tested agronomic growth parameters. The treatment with inoculated M. incognita alone reduced plant height, fresh shoot, and fresh root weight by 44.7%, 29.8%, and 32.8% respectively over uninoculated healthy control. Histopathological studies on the interaction of Pochonia chlamydosporia and Meloidogyne incognita on tomato roots revealed anatomical changes among treatments. Less number of galls with small in size and scarcer abnormalities in the vascular cylinder was observed in plants inoculated with P. chlamydosporia and M. incognita than the plants treated with nematode only. The fungus was seen in in the intercellular spaces of cortical and epidermal cells while the vascular bundles of the plant remain intact, inoculated only with P. chlamydosporia. In the infected roots, many mature females were seen which feed on giant cells. The findings also revealed that control healthy plants were not affected and no histological changes were noted.

Keywords: histopathology, Pochonia chlamydosporia, Meloidogyne incognita, tomato

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Authors: Angkana Tungkasamit, Ladda Silanoi , Teerachai Nethanomsak, Sitthipon Art-in, Siribhong Bhiasiri

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As the date for the commencement of the ASEAN Community in Year 2015 is approaching, it has become apparent to all that there is an urgent need to get Thai people ready to meet the challenge of entering into the Community confidently. Our research team has been organized by the Faculty of Education, Khon Kaen University with the task of training administrators and teachers of the schools along the borders with Laos People’s Democratic Republic and the Kingdom of Cambodia to be able to develop supplementary courses on ASEAN Community. The course to be developed is based on the essential elements of the Community, i.e. general backgrounds of the member countries, the education, social and economic life in the Community and social skills needed for a good citizen of the ASEAN Community. The study, based on learning outcome and learning management process as a basis for inquiry, was a research and development in nature using participative action research as a means to achieve the goal of helping school administrators and teachers to learn how to develop supplementary courses to be used in their schools. A post-workshop evaluation of the outcome was made and found that, besides the successfully completed supplementary course, the participants were satisfied with their participation in the workshop because they had participated in every step of the development activity, from the beginning to the end.

Keywords: development of supplementary course, ASEAN community, social studies, northeastern border area of Thailand

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Authors: Mozhgan Chaichi, Farhad Sharif, Saeede Mazinani

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Polymer nanocomposites are a new class of materials for fabricating future multifunctional and lightweight structures. To obtain good mechanical, thermal and electrical properties, it is essential to achieve uniform dispersion of nanoparticles in polymer matrix. Alignment of nanoparticles in matrix can enhance mechanical, thermal, electrical and barrier properties of nanocomposites in oriented direction. Fe3O4 nanoparticles have generated huge activity in many areas of science and engineering due to its magnetic properties. Magnetic nanoparticles have been investigated for a wide range of applications in sensors, magnetic energy storage, environmental remediation, heterogeneous catalysts and drug delivery. The magnetic response from the Fe3O4 nanoparticles can facilitate with the alignment of nanofillers in a polymer matrix under magnetic field, aiming at fabricating composites with directional properties and functions. Here we report oriented nanocomposites based on Fe3O4 nanoparticles and poly (vinyl alcohol) (PVA), which prepared via a facile aqueous solution by applying a low external magnetic field (750 G). A significant enhancement of mechanical properties, and especially toughness of nanofilms, of oriented PVA/ Fe3O4 nanocomposites is obtained at low nanoparticles loading. Orientation of nanoparticles can align polymer chains and enhance mechanical properties. For example, orientation of 0.1 wt. % Fe3O4 nanoparticles increase 31% toughness and 23% modulus of oriented nanocomposite in compare of pure films, which indicate good dispersion of nanoparticles and efficient load transfer between nanoparticles and matrix.

Keywords: magnetic nanoparticles, nanocomposites, toughness, orientation

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Authors: Gousilin Leandra Rocha Da Silva, Stéfani T. A. Dantas, Bruna F. Rossi, Erika R. Bonsaglia, Ivana G. Castilho, Terue Sadatsune, Ary Fernandes Júnior, Vera l. M. Rall

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Kidney failure causes decreased diuresis and accumulation of nitrogenous substances in the body. To increase patient survival, hemodialysis is used as a partial substitute for renal function. However, contamination of the water used in this treatment, causing bacteremia in patients, is a worldwide concern. The Burkholderia cepacia complex (Bcc), a group of bacteria with more than 20 species, is frequently isolated from hemodialysis water samples and comprises opportunistic bacteria, affecting immunosuppressed patients, due to its wide variety of virulence factors, in addition to innate resistance to several antimicrobial agents, contributing to the permanence in the hospital environment and to the pathogenesis in the host. The objective of the present work was to characterize molecularly and phenotypically Bcc isolates collected from the water and dialysate of the Hemodialysis Unit and from the blood of patients at a Public Hospital in Botucatu, São Paulo, Brazil, between 2019 and 2021. We used 33 Bcc isolates, previously obtained from blood cultures from patients with bacteremia undergoing hemodialysis treatment (2019-2021) and 24 isolates obtained from water and dialysate samples in a Hemodialysis Unit (same period). The recA gene was sequenced to identify the specific species among the Bcc group. All isolates were tested for the presence of some genes that encode virulence factors such as cblA, esmR, zmpA and zmpB. Considering the epidemiology of the outbreak, the Bcc isolates were molecularly characterized by Multi Locus Sequence Type (MLST) and by pulsed-field gel electrophoresis (PFGE). The verification and quantification of biofilm in a polystyrene microplate were performed by submitting the isolates to different incubation temperatures (20°C, average water temperature and 35°C, optimal temperature for group growth). The antibiogram was performed with disc diffusion tests on agar, using discs impregnated with cefepime (30µg), ceftazidime (30µg), ciprofloxacin (5µg), gentamicin (10µg), imipenem (10µg), amikacin 30µg), sulfametazol/trimethoprim (23.75/1.25µg) and ampicillin/sulbactam (10/10µg). The presence of ZmpB was identified in all isolates, while ZmpA was observed in 96.5% of the isolates, while none of them presented the cblA and esmR genes. The antibiogram of the 33 human isolates indicated that all were resistant to gentamicin, colistin, ampicillin/sulbactam and imipenem. 16 (48.5%) isolates were resistant to amikacin and lower rates of resistance were observed for meropenem, ceftazidime, cefepime, ciprofloxacin and piperacycline/tazobactam (6.1%). All isolates were sensitive to sulfametazol/trimethoprim, levofloxacin and tigecycline. As for the water isolates, resistance was observed only to gentamicin (34.8%) and imipenem (17.4%). According to PFGE results, all isolates obtained from humans and water belonged to the same pulsotype (1), which was identified by recA sequencing as B. cepacia¸, belonging to sequence type ST-767. By observing a single pulse type over three years, one can observe the persistence of this isolate in the pipeline, contaminating patients undergoing hemodialysis, despite the routine disinfection of water with peracetic acid. This persistence is probably due to the production of biofilm, which protects bacteria from disinfectants and, making this scenario more critical, several isolates proved to be multidrug-resistant (resistance to at least three groups of antimicrobials), turning the patient care even more difficult.

Keywords: hemodialysis, burkholderia cepacia, PFGE, MLST, multi drug resistance

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Authors: Alvaro Ramírez, Martín Muñoz-Morales, Ester L. Fernández, Javier Llanos

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Carbon blacks are value-added materials typically produced through the incomplete combustion or thermal decomposition of hydrocarbons. This material has been used as catalysts in many different applications, but in last decade it has been explored its potential in green chemistry applications. Among them, the electrochemical production of H2O2 has attracted many interests because of their properties as high oxidant capacity or their industrial interest as bleaching agent. Carbon blacks are commonly used in this application in a catalytic ink that it is drop-casted on supporting electrodes and act as catalysts for the electrochemical production of H₂O₂ through oxygen reduction reaction (ORR). However, according with the different structural and electrochemical behavior of each type, applications might be different. In this line the term ‘carbon black’, has to be considered as a generic name that do not guarantee any properties if any further description was mentioned. In fact, different specific surface area, surface functional groups, porous structure and electro catalysts effect seem very important for electrochemical applications and considerable differences were found during the analysis of four type of carbon blacks. Thus, the aim of this work is to study the evolution of main properties already mentioned to differentiate among some types of carbon blacks and the suitable ones for the ORR to produce H₂O₂ with improved selectivity and efficiency. Results indicate that number and size of porous is one of the key parameters but also the surface functional groups both highly related to the overall process efficiency.

Keywords: carbon blacks, oxygen reduction reaction, hydrogen peroxide, porosity, surface functional groups

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Authors: Agil Gemilang Ramadhan, Novian Triandanu

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Since 1929, the first appearance in sea level, Anak Krakatau volcano growth relatively quickly. During the 80 years up to 2010 has reached the height of 320 meter above sea level. The possibility of catastrophic explosive eruption could happen again if the chemical composition of rocks from the eruption changed from alkaline magma into acid magma. Until now Anak Krakatau volcanic activity is still quite active as evidenced by the frequency of eruptions that produced ash sized pyroclastic deposits - bomb. Purpose of this study was to identify changes in the percentage of rock geochemistry any results eruption of Anak Krakatau volcano to see consistency change the percentage content of silica in the magma that affect the type of volcanic eruptions. Results from this study will be produced in the form of a diagram the data changes the chemical composition of rocks of Anak Krakatau volcano. Changes in the composition of any silica eruption are illustrated in a graph. If the increase in the percentage of silica is happening consistently and it is assumed to increase in the time scale of a few percent, then to achieve silica content of 68 % (acid composition) that will produce an explosive eruption will know the approximate time. All aspects of the factors driving the increased threat of danger to the public should be taken into account. Catastrophic eruption katatropis mitigation can be planned early so that when these disasters happen later, casualties can be minimized.

Keywords: Krakatau volcano, rock geochemistry, catastrophic eruption, mitigation

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Authors: Ivan Maguire, Alan Barrett, Alex Forte, Sandra Kwiatkowska, Rohit Mishra, Jens Ducrèe, Fiona Regan

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Biofouling is defined as the gradual accumulation of Biomimetics refers to the use and imitation of principles copied from nature. Biomimetics has found interest across many commercial disciplines. Among many biological objects and their functions, aquatic animals deserve a special attention due to their antimicrobial capabilities resulting from chemical composition, surface topography or other behavioural defences, which can be used as an inspiration for antifouling technology. Marine biofouling has detrimental effects on seagoing vessels, both commercial and leisure, as well as on oceanographic sensors, offshore drilling rigs, and aquaculture installations. Sensor optics, membranes, housings and platforms can become fouled leading to problems with sensor performance and data integrity. While many anti-fouling solutions are currently being investigated as a cost-cutting measure, biofouling settlement may also be prevented by creating a surface that does not satisfy the settlement conditions. Brill (Scophthalmus rhombus) is a small flatfish occurring in marine waters of Mediterranean as well as Norway and Iceland. It inhabits sandy and muddy coastal waters from 5 to 80 meters. Its skin colour changes depending on environment, but generally is brownish with light and dark freckles, with creamy underside. Brill is oval in shape and its flesh is white. The aim of this study is to translate the unique micro-topography of the brill scale, to design marine inspired biomimetic surface coating and test it against a typical fouling organism. Following extensive study of scale topography of the brill fish (Scophthalmus rhombus) and the settlement behaviour of the diatom species Psammodictyon sp. via SEM, two state-of-the-art antifouling surface solutions were designed and investigated; A brill fish scale bioinspired surface pattern platform (BFD), and generic and uniformly-arrayed, circular micropillar platform (MPD), with offsets based on diatom species settlement behaviour. The BFD approach consists of different ~5 μm by ~90 μm Brill-replica patterns, grown to a 5 μm height, in a linear array pattern. The MPD approach utilises hexagonal-packed cylindrical pillars 10.6 μm in diameter, grown to a height of 5 μm, with vertical offset of 15 μm and horizontal offset of 26.6 μm. Photolithography was employed for microstructure growth, with a polydimethylsiloxane (PDMS) chip-based used as a testbed for diatom adhesion on both platforms. Settlement and adhesion tests were performed using this PDMS microfluidic chip through subjugation to centrifugal force via an in-house developed ‘spin-stand’ which features a motor, in combination with a high-resolution camera, for real-time observing diatom release from PDMS material. Diatom adhesion strength can therefore be determined based on the centrifugal force generated at varying rotational speeds. It is hoped that both the replica and bio-inspired solutions will give comparable anti-fouling results to these synthetic surfaces, whilst also assisting in determining whether anti-fouling solutions should predominantly be investigating either fully bioreplica-based, or a bioinspired, synthetically-based design.

Keywords: anti-fouling applications, bio-inspired microstructures, centrifugal microfluidics, surface modification

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Authors: Faisal Alsaaq

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Hydrographic surveys have traditionally relied on the availability of tide information for the reduction of sounding observations to a common datum. In most cases, tide information is obtained from tide gauge observations and/or tide predictions over space and time using local, regional or global tide models. While the latter often provides a rather crude approximation, the former relies on tide gauge stations that are spatially restricted, and often have sparse and limited distribution. A more recent method that is increasingly being used is Global Navigation Satellite System (GNSS) positioning which can be utilised to monitor height variations of a vessel or buoy, thus providing information on sea level variations during the time of a hydrographic survey. However, GNSS heights obtained under the dynamic environment of a survey vessel are affected by “non-tidal” processes such as wave activity and the attitude of the vessel (roll, pitch, heave and dynamic draft). This research seeks to examine techniques that separate the tide signal from other non-tidal signals that may be contained in GNSS heights. This requires an investigation of the processes involved and their temporal, spectral and stochastic properties in order to apply suitable recovery techniques of tide information. In addition, different post-mission and near real-time GNSS positioning techniques will be investigated with focus on estimation of height at ocean. Furthermore, the study will investigate the possibility to transfer the chart datums at the location of tide gauges.

Keywords: hydrography, GNSS, datum, tide gauge

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Authors: Jaspal Rana, Varinder Singh

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Oxidative stress has been identified as an underlying cause of ischemia-reperfusion (IR) related cognitive dysfunction and brain damage. Therefore, antioxidant based therapies to treat IR injury are being investigated. Allium cepa L. (onion) is used as culinary medicine and is documented to have marked antioxidant effects. Hence, the present study was designed to evaluate the effect of A. cepa outer scale extract (ACE) against IR induced cognition and biochemical deficit in mice. ACE was prepared by maceration with 70% methanol and fractionated into ethylacetate and aqueous fractions. Bilateral common carotid artery occlusion for 10 min, followed by 24 h reperfusion, was used to induce cerebral IR injury. Following IR injury, ACE (100 and 200 mg/kg) was administered orally to animals for 7 days once daily. Behavioral outcomes (memory and sensorimotor functions) were evaluated using Morris water maze and neurological severity score. Cerebral infarct size, brain thiobarbituric acid reactive species, reduced glutathione, and superoxide dismutase activity were also determined. Treatment with ACE significantly ameliorated IR mediated deterioration of memory and sensorimotor functions and rose in brain oxidative stress in animals. The results of the present investigation revealed that ACE improved functional outcomes after cerebral IR injury which may be attributed to its antioxidant properties.

Keywords: allium cepa, cerebral ischemia, memory, sensorimotor

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Authors: Zahra Alimorad

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There is a strong belief that language teachers' actual practices in the classroom context are largely determined by the underlying perceptions they hold about the nature of language and language learning. That being so, it can be envisaged that teaching procedures of ESP (English for Specific Purposes) teachers teaching reading comprehension will mainly be driven by their perceptions about the nature of reading. To examine this issue, four Iranian university professors holding Ph.D. in either TEFL (Teaching English as a Foreign Language) or English Literature who were teaching English to Engineering and Sciences students were recruited to participate in this study. To collect the necessary data, classroom observations and follow-up semi-structured interviews were used. Furthermore, the materials utilized by the teachers such as textbooks, syllabuses, and tests were also examined. Although it can be argued that their perceptions were partially compatible with the established principles, results of the study pointed to a lack of congruence between these teachers' perceptions and their practices, on the one hand, and between the established principles and the practices, on the other. While the literature mostly supports a metacognitive-strategy approach to reading comprehension, the teachers were mainly adopting a skills-based approach to the teaching of reading. That is, they primarily focused on translation as the core activity in the classroom followed by reading aloud, defining words, and explaining grammatical structures. This divergence was partly attributed to the contextual constraints and partly to students' lack of motivation by the teachers.

Keywords: English teachers, perceptions, practice, principles, reading comprehension

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Authors: Olga Leontjeva

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In the age of Artificial Intelligence (AI), some organization management approaches need to be adapted or changed. Human Resource Management (HRM) is a part of organization management that is under the managers' focus nowadays, because AI integration into organization activities brings some HRM-connected challenges. The topic became more significant during the crises of many organizations in the world caused by the coronavirus pandemic (COVID-19). The paper presents an approach, which will be used for the study that is going to be focused on the various case analysis. The author of the future study will analyze the cases of the organizations from Latvia and Spain that are grouped by the size, type of activity and area of business. The information for the cases will be collected through structured interviews and online surveys. The main result presented is the questionnaire developed that will be used for the study as well as the definition and description of sampling. The first round of the survey will be based on convenience sampling that is the main limitation of the study. To conclude, the approach developed will help to collect valid data if the organizations participating in the survey are ready to share their cases in depth, so the researchers could draw the right conclusions and generalize compared organizations’ cases. The questionnaire developed for the survey is applicable for both written online data collection as well as for the interviews. The case analysis will help to identify some HRM challenges that are connected to AI integration into organization activities such as management of different generation employees and their training peculiarities.

Keywords: age of artificial intelligence, case analysis, generation Y and Z employees, human resource management

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Authors: Maryam Kiani

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This study focuses on the development of composite nanomaterials based on SiO2 and carbon black for oxygen reduction reaction (ORR) electrocatalysts in batteries and fuel cells. The aim was to explore the potential of these composite materials as efficient catalysts for ORR, which is a critical process in energy conversion devices. The SiO2/carbon black composite nanomaterials were synthesized using a facile and scalable method. The morphology, structure, and electrochemical properties of the materials were characterized using various techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), and electrochemical measurements. The results demonstrated that the incorporation of SiO2 into the carbon black matrix enhanced the ORR performance of the composite material. The composite nanomaterials exhibited improved electrocatalytic activity, enhanced stability, and increased durability compared to pure carbon black. The presence of SiO2 facilitated the formation of active sites, improved electron transfer, and increased the surface area available for ORR. This study contributes to the advancement of battery and fuel cell technology by offering a promising approach for the development of high-performance ORR electrocatalysts. The SiO2/carbon black composite nanomaterials show great potential for improving the efficiency and durability of energy conversion devices, leading to more sustainable and efficient energy solutions.

Keywords: oxygen reduction reaction, batteries, fuel cells, electrrocatalyst

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Authors: Yin Hua Zhang

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Cardiac metabolism is essential in myocardial contraction. In addition to glucose, fatty acids (FA) are essential in producing energy in the myocardium since FA-dependent beta-oxidation accounts for > 70-90% of cellular ATP under resting conditions. However, metabolism shifts from FAs to glucose utilization during disease progression (e.g. hypertrophy and ischemic myocardium), where glucose oxidation and glycolysis become the predominant sources of cellular ATP. At advanced failing stage, both glycolysis and beta-oxidation are dysregulated, result in insufficient supply of intracellular ATP and weakened myocardial contractility. Undeniably, our understandings of myocyte function in healthy and diseased hearts are based on glucose (10 mM)-dependent metabolism because glucose is the “sole” metabolic substrate in most of the physiological experiments. In view of the importance of FAs in cardiovascular health and diseases, we aimed to elucidate the impacts of FA supplementation on myocyte contractility and evaluate cellular mechanisms those mediate the functions in normal heart and with pathological stress. In particular, we have investigated cardiac excitation-contraction (E-C) coupling in the presence and absence of FAs in normal and hypertensive rat left ventricular (LV) myocytes. Our results reveal that FAs increase mitochondrial activity, intracellular [Ca²+]i, and LV myocyte contraction in healthy LV myocytes, whereas FA-dependent cardiac inotropyis attenuated in hypertension. FA-dependent myofilament Ca²+ desensitization could be fundamental in regulating [Ca²+]i. Collectively, FAs supplementation resets cardiac E-C coupling scheme in healthy and diseased hearts.

Keywords: hypertension, fatty acid, heart, calcium

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Authors: Suparmi, Sampurna

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Sodium nitrite which is widespread used as a color fixative and preservative in foods can increase oxidative stress and cause hemolytic anemia. Consumption of food supplement containing sufficient antioxidant, e.g. chlorophyll, reported can decrease these negative effects. This study was conducted to determine the effect of chlorophyll from Sauropus androgynus leaves on Malodialdehide (MDA) and ferritin level. Experimental research with post-test only control group design was conducted using 24 female mice strain Balb-c. Sodium nitrite 0.3 ml/head/day given during 18 days, while the chlorophyll or Cu-chlorophyllin as much as 0.7 ml/head/day given the following day for 14 days. The mean of MDA levels of blood plasma in the control group, NaNO2 induction, induction NaNO2 and chlorophyll of S. androgynus leaves, induction of NaNO2 and Cu-chlorophyllin from K-Liquid in sequence is 2.10±0.11mol/L, 3.44±0.38 mol/L, 2.31±0.18 mol/L, 2.31±0.13 mol/L, whilst the ferritin levels mean in each group is 62.71±6.42 ng/ml; 63.22±7.59 ng/ml; 67.45±8.03 ng/ml, and 64.74±7.80 ng/ml, respectively. Results of Mann Whitney test found no significant difference in MDA levels (p>0.05), while the One-Way Anova test result found no significant difference in ferritin levels between the groups of mice that received S. androgynus chlorophyll with a group of mice that received Cu-chlorophyllin after induction NaNO2 (p>0.05). This indicates that chlorophyll from S. androgynus leaves as effective as Cu-chlorophyllin in decrease of MDA levels and increase of ferritin levels. Chlorophyll from S. androgynus are potential as food supplement in anemic conditions caused by sodium nitrite consumptions.

Keywords: ferritin, MDA, chlorophyll, sodium nitrite

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Authors: Caroline Denaes

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The ability to read is crucial for a successful path in school and in a social and professional context. Children with mild intellectual disability are confronted to serious difficulties in literacy. A lot of them do not read or are illiterate. Only one child out of five is able to acquire basic reading skills, which increases the likelihood to misfit in society, especially when these children grow up and cannot manage themselves in situations requiring higher reading levels. One way to help these children acquiring basic reading skills is to use analogical reasoning, as some researchers demonstrated that this mechanism is fundamental for any reading process. For this purpose, we developed computerized analogies displayed on a touch screen tablet. Analogies are comparisons that give children a framework they can use to understand new information. They work by comparing one thing to another in order to emphasize some mutual quality. If one of the items is unfamiliar, that mutual quality can help make it understandable, or it can cause the children to consider something familiar in some new way, such as transferring what they know about familiar words to help them identify unfamiliar words. In addition, using touch screen tablets represents several advantages: the ease of use, the relevance to this specific population and the appeal of a self-directed activity gives individuals and practitioners a modern tool that differs from the traditional paper-and-pencil material. In addition, the touch screen dimension is especially appropriate for children as assistive technology has been found to be more motivating that any other types of devices and improves the children’ attention span.

Keywords: literacy, intellectual disabilities, touch screen techonology, literacy skill

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Authors: Mubeshera Tufail

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The purpose of the study was to explore the experiences and challenges faced by teachers and students with Flipped Classroom Instruction (FCI) for an undergraduate course at university level. The Flipped Classroom lesson plan consisted of two components: one was out-of-class component consisting of learning material for reading for students and other was within-class component involving a class quiz, class activity and the feedback/further reading task. Besides, experiences, the research study also covered the adaptations made to improve their experiences with Flipped Classroom during the study. The phenomenological research strategy was used for this research study. The data consisted of weekly reflective journals documented by class teacher and students. The reflective journals were recorded by teacher and students while working in Flipped Classroom for an undergraduate course at university level. The main challenges highlighted by teacher were related to effort and time required for planning, time management and students' guidance for shift of their role from passive to independent learner. The main challenges found in reflective journals of students were personal computers issue, electricity and internet speed issue. It is recommended to adapt to some locally useful lesson planning and classroom management techniques to enhance the effectiveness of Flipped Classroom Instruction in an undergraduate university level course.

Keywords: flipped classroom instruction, undergraduate students, independent learner, technology-integrated classroom

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Authors: Neha Sharma, Kanthi K. Kondepudi, Naveen Gupta

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Phytases are phytate specific phosphatases catalyzing the step-wise dephosphorylation of phytate, which acts as an anti-nutritional factor in food due to its strong binding capacity to minerals. In recent years microbial phytases have been explored for improving nutritional quality of food. But the major limitation is acceptability of phytases from these microorganisms. Therefore, efforts are being made to isolate organisms which are generally regarded as safe for human consumption such as Lactic Acid Bacteria (LAB). Phytases from these organisms will have an edge over other phytase sources due to its probiotic attributes. Only few LAB have been reported to give phytase activity that too is generally seen as intracellular. LAB producing extracellular phytase will be more useful as it can degrade phytate more effectively. Moreover, enzyme from such isolate will have application in food processing also. Only few species of Lactobacillus producing extracellular phytase have been reported so far. This study reports the isolation of a probiotic strain of Lactobacillus fermentum spp KA1 which produces extracellular phytase. Conditions for the optimal production of phytase have been optimized and the enzyme production resulted in an approximately 13-fold increase in yield. The phytate degradation potential of extracellular phytase in rice bran has been explored and conditions for optimal degradation were optimized. Under optimal conditions, there was 43.26% release of inorganic phosphate and 6.45% decrease of phytate content.

Keywords: Lactobacillus, phytase, phytate reduction, rice bran

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Authors: Nilgun Kuskonmaz

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Ceramic molding can produce castings with fine detail, smooth surface and high degree of dimensional accuracy. All these features are the key factors for producing decorated glass moulds. In the ceramic mold casting process, the fundamental parameters affecting the mold-metal reactions are the composition and the properties of the refractory materials used in the production of ceramic mold. As a result of the reactions taking place between the liquid metal and mold surface, it is not possible to achieve a perfect surface quality, a fine surface detail and maintain a high standard dimensional tolerances. The present research examines the effects of the binder composition on the structural and physical properties of the zircon ceramic mold. In the experiment, the ceramic slurry was prepared by mixing the refractory powders (zircon(ZrSiO4), mullit(3Al2O32SiO2) and alumina (Al2O3)) with the low alkaline silica (ethyl silicate (C8H20O4Si)) and acidic type gelling material suitable binder and gelling agent. This was followed by pouring that ceramic slurry on to a silicon pattern. After being gelled, the mold was removed from the silicon pattern and dried. Then, the ceramic mold was subjected to the reaction sintering at 1600°C for 2 hours in the furnace. The stainless steel (SS) was cast into the sintered ceramic mold. At the end of this process it was observed that the surface quality of decorated glass mold.

Keywords: ceramic mold, stainless steel casting, decorated glass mold

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Authors: M. Taleb, G. Tail, F. Z. Kara, B. Djedouani T. Moussa

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Necrophagous insects usually colonize cadavers within a short time after death. However, they are influenced by weather conditions, and their distribution and activity vary according to different time scales, which can affect the post-mortem interval (PMI) estimation. As no data have been published in Algeria on necrophagous insects visiting corpses, two field surveys were conducted in July 2012 and March 2013 at the National Institute for Criminalistics and Criminology (INCC) using rabbit carcasses (Oryctolagus cuniculus L.). The trials were designed to identify the necrophagous Diptera fauna of Algiers, Algeria and examine their variations according to environmental variables. Four hundred and eighteen Diptera adults belonging to five families were captured during this study. The species which were identified on human corpses in different regions of Algeria were also observed on the rabbit carcasses. Although seasonal variations of the species were observed, their abundance did not significantly vary between the two seasons. In addition to seasonal effects, the ambient temperature, the wind speed, and precipitation affect the number of trapped flies. These conclusions highlight the necessity of considering the environmental factors at a scene to estimate the post-mortem interval accurately. It is hoped that these findings provide basic information regarding the necrophagous Diptera fauna of Algeria.

Keywords: forensic entomology, necrophagous diptera, post-mortem interval, abiotic factors, Algeria

Procedia PDF Downloads 360