Search results for: resistance switching

Authors: Ayman K. El Essawy, Amal M. Hosny, Hala M. Abu Shady

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The rapid detection of TB and drug resistance, both optimizes treatment and improves outcomes. In the current study, respiratory specimens were collected from 155 patients. Conventional susceptibility testing and MIC determination were performed for rifampicin (RIF) and isoniazid (INH). Genotype MTBDRplus assay, which is a molecular genetic assay based on the DNA-STRIP technology and specific gene sequencing with primers for rpoB, KatG, and mab-inhA genes were used to detect mutations associated with resistance to rifampicin and isoniazid. In comparison to other categories, most of rifampicin resistant (61.5%) and isoniazid resistant isolates (47.1%) were from patients relapsed in treatment. The genotypic profile (using Genotype MTBDRplus assay) of multi-drug resistant (MDR) isolates showed missing of katG wild type 1 (WT1) band and appearance of mutation band katG MUT2. For isoniazid mono-resistant isolates, 80% showed katG MUT1, 20% showed katG MUT1, and inhA MUT1, 20% showed only inhA MUT1. Accordingly, 100% of isoniazid resistant strains were detected by this assay. Out of 17 resistant strains, 16 had mutation bands for katG distinguished high resistance to isoniazid. The assay could clearly detect rifampicin resistance among 66.7% of MDR isolates that showed mutation band rpoB MUT3 while 33.3% of them were considered as unknown. One mono-resistant rifampicin isolate did not show rifampicin mutation bands by Genotype MTBDRplus assay, but it showed an unexpected mutation in Codon 531 of rpoB by DNA sequence analysis. Rifampicin resistance in this strain could be associated with a mutation in codon 531 of rpoB (based on molecular sequencing), and Genotype MTBDRplus assay could not detect the associated mutation. If the results of Genotype MTBDRplus assay and sequencing were combined, this strain shows hetero-resistance pattern. Gene sequencing of eight selected isolates, previously tested by Genotype MTBDRplus assay, could detect resistance mutations mainly in codon 315 (katG gene), position -15 in inhA promotes gene for isoniazid resistance and codon 531 (rpoB gene) for rifampicin resistance. Genotyping techniques allow distinguishing between recurrent cases of reinfection or reactivation and supports epidemiological studies.

Keywords: M. tuberculosis, rpoB, KatG, inhA, genotype MTBDRplus

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Authors: Saci Abdelhakim Ferkous, Khedoudja Soudani, Smail Haddadi

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This paper presents the results of a laboratory experimental study that explores the skid resistance of asphalt concrete mixtures made of local low-performance aggregates by partially replacing sand with olive mill waste (OMW). OMW was mixed with aggregates using a dry process by replacing sand with contents of 5%, 7%, 10% and 15%. The mechanical performances of the mixtures were evaluated using the Marshall and Duriez tests. A modified accelerated polishing machine was used as polishing equipment, and a British pendulum tester (BPT) was used to test the skid resistance of the samples. Finally, texture parameter analysis was performed using scanning electron microscopy (SEM) and Mountains Map software to assess the effect of OMW on the friction coefficient evolution. Using a distinct road wheel for a modified version of an accelerated polishing machine, which is normally used to determine the polished stone value of aggregates, the results showed that the addition of OMW up to 10% conferred a better skid resistance in comparison to normal asphalt concrete. The presence of olive mill waste in the mixture until 15% guarantees a gain of 22%-29% in skid resistance after polishing compared with the reference mix. Indeed, from texture parameter analysis, it was observed that there was differential wear of the lightweight aggregates (OMW) compared to the other aggregates during the polishing process, which created a new surface microtexture that had new peaks and led to a good level of friction compared to the mixtures without OMW. In general, it was found that OMW is a promising modifier for asphalt mixtures with both engineering and economic merits.

Keywords: skid resistance, olive mill waste, polishing resistance, accelerated polishing machine, local materials, sustainable development.

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Authors: Long-Shan Wu, Ming-Chen Ko, Chien-Chang Ho, Po-Fu Lee, Li-Yun Chen, Ching-Yu Tseng

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The purpose of this study was to determine whether progressive aerobic exercise intensity effects the changes in insulin resistance indicators among obese college students in Taiwan. Forty-eight obese subjects [body mass index (BMI) ≧ 27 kg/m2, aged 18-26 years old] were randomized into four equal groups (n = 12): light-intensity training group (LITG): 40-50% of their heart rate reserve (HRR); middle-intensity training group (MITG): 50-70% of their HRR; high-intensity training group (HITG): 70-80% of their HRR, and control group (CG). The aerobic exercise training program was performed 60 minutes per day on a treadmill three days/week in a training period of 12 weeks. All subjects’ anthropometric data, blood biochemical parameters, and health-related physical fitness components were measured at baseline and after 12 weeks. At baseline, all insulin resistance indicators did not differ significantly among the four groups (p > 0.05). After 12-week exercise intervention, the HITG had significantly more changes in insulin level than the MITG, LITG, and CG. Our findings suggested that a short-term aerobic exercise program can play an important role in improving insulin resistance indicators; either middle-intensity training significantly increases the insulin level, but the high-intensity exercise training program effectively improves obese college students’ insulin resistance.

Keywords: aerobic training, exercise intensity, insulin resistance, obesity

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Authors: H.Yari, M. Mohseni, Z. Ranjbar

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In this work a typical automotive clearcoat is modified with a combination of hyperbranched polymer (HBP) and polyhedral oligomeric silsesquioxane (POSS) nanostructures to simultaneously enhance the scratch resistance and healing ability of the resulting films. Micro-scratch and healing data revealed that these goals were achieved at high loadings of modifiers. Enhanced scratch resistance was attributed to the improved elastic recovery of the clearcoats in presence of modifiers. In addition, improved healing performance due to the partial replacement of covalent cross-links with physical ones resulted from the unique globular highly branched structure of HBP and POSS macromolecules.

Keywords: automotive clearcoat, POSS building blocks scratch resistance, self-healing

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Authors: Adnan I. O. Zaid, Safwan M. A. Alqawabah

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Review of the available literature on grain refinement of aluminum and its alloys reveals that little work is published on the effect of refiners on mechanical characteristics and wear resistance. In this paper, the effect of addition of Zr to Al grain refined by Ti+B on its metallurgical, mechanical characteristics and wear resistance both in the as cast and after extrusion condition are presented and discussed. It was found that Addition of Zr to Al resulted in deterioration of its mechanical strength and hardness, whereas it resulted in improvement of both of them when added to Al grain refined by Ti+B. Furthermore it was found that the direct extrusion process resulted in further increase of the mechanical strength and hardness of Al and its micro-alloys. Also it resulted in increase of their work hardening index, n, i.e. improved their formability, hence it reduces the number of stages required for forming at large strains in excess of the plastic instability before Zr addition.

Keywords: aluminum, grain refinement, titanium + boron, zirconium, mechanical characteristics, wear resistance, direct extrusion

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Authors: Marvin R. Tenecio

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The analysis of "religious resistance" has been prevalent in Asian and Philippine studies. Discussions on religious resistance from a variety of perspectives are deemed as crucial turning points in the concept's ongoing development and expansion. By broadening the backdrop of religious protest between the early 1960s and the late 1980s, the researchers contend that a study examining the role carried by the Catholic Church in the upheavals against dictatorships in South Korea and the Philippines would be beneficial to the body of knowledge. This study examines a variety of historical writings about the activities occurring at that time. The researchers also compare and contrast the Catholic Church's contributions to the Korean and Philippine resistance against Park Chung-Hee and Ferdinand Marcos Sr., respectively, during the early 1960s until the late 1980s, using the lens of history from below, particularly the Pasyon and Revolution. The Catholic Church stood out against human rights abuses, promoted social justice, and mobilized the public for political reform in response to the dictatorships in South Korea and the Philippines. Even though the specific circumstances and personalities may have changed, the Church's position in both countries was vital in opposing authoritarian governments and supporting democratic movements.

Keywords: resistance, movements, catholic, church, dictatorship

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Authors: Amani Jaber-Awida

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This study examines two bilingual phenomena in the narratives of Arabic Hebrew and Hebrew-English bilingual adults in Israel: CO memories and code-switching (CS). The study examined these phenomena in the context of autobiographical memory, using a cue word technique. Student experimenters held two sessions in the homes of the participants. In separate language sessions, the participant was asked to look first at each of 16 cue words and then to state a concrete memory. After stating the memory, participants reported whether their memories were in the same language of the experiment session or different. Memories were classified as ‘Crossovers’ (CO) or ‘Same Language’ (SL) according to participants' self-reports. Participants were also required to elaborate about the setting, interlocutors and other languages involved in the specific memory. Beyond replicating the procedure of cuing technique, one memory from a specific lifespan period was chosen per participant, and the participant was required to provide further details about it. For the more detailed memories, CS count was conducted. Both bilingual groups confirmed the Reminiscence Bump phenomenon, retrieving more memories in the 10-30 age period. CO memories prevailed in second language sessions (L2). Same language memories were more abundant in first language sessions (L1). Higher CS frequency was found in L2 sessions. Finally, as predicted, 'individual' CS was prevalent in L2 sessions, but 'community-based' CS was not higher in L1 sessions. The two bilingual measures in this study, crossovers, and CS came from different research traditions, the former from an experimental paradigm in the psychology of autobiographical memory based on self-reported judgments, the latter a behavioral measure from linguistics. This merger of approaches offers new insight into the field of bilingual autobiographical memory. In addition, the study attempted to shed light on the investigation of motivations for CS, beginning with Walters’ SPPL Model and concluding with a distinction between ‘community-based’ and individual motivations.

Keywords: bilinguals, code-switching, crossover memories, narratives

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Authors: M. Dahiru, O. I. Enabulele

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The research wish to investigate the occurrence of multidrug- resistant Acinetobacter, in carrot and estimate the role of carrot in its transmission, in a rapidly growing urban population. Thus, 50 carrot samples were collected from Jakara wastewater irrigation farms and analyzed on MacConkey agar and screened by Microbact 24E (Oxoid) and susceptibility of isolates tested against 10 commonly used antibiotics. Acinetobacter baumannii and A. lwoffii were isolated in 22.00% and 16% of samples respectively. Resistance to ceporex and penicillin of 36.36% and 27.27% in A. baumannii, and sensitivity to ofloxacin, pefloxacin, gentimycin and co-trimoxazole, were observed. However, for A. lwoffii apart from 37.50% resistance to ceporex, it was also resistant to all other drugs tested. There was a similarity in the resistant shown by A. baumannii and A. lwoffii to fluoroquinolones drugs and β- lactame drugs families in addition to between sulfonamide and animoglycoside demonstrated by A. lwoffii. Interestingly, when resistant similarities to different antibiotics were compared for A. baumannii and A. lwoffii as a whole, significant correlation was observed at P < 0.05 to CPX to NA (46.2%), and SXT to AU (52.6%) respectively, and high multi drug resistance (MDR) of 27.27% and 62.50% by A. baumannii and A. lwoffii respectively and overall MDR of 42.11% in all isolates. The occurrence of multidrug-resistance pathogen in carrot is a serious challenge to public health care, especially in a rapidly growing urban population where subsistence agriculture contributes greatly to urban livelihood and source of vegetables.

Keywords: urban agriculture, public health, fluoroquinolone, sulfonamide, multidrug-resistance

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Authors: Mohammad Mardi

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Generally, the resistivity is high in oil layer and low in water layer. Yet there are intervals of oil-bearing zones showing low resistivity, high porosity, and low resistance. In the typical example, well A (depth: 4341.5-4372.0m), both Spectral Gamma Ray (SGR) and Corrected Gamma Ray (CGR) are relatively low; porosity varies from 12-22%. Above 4360 meters, the reservoir shows the conventional positive difference between deep and shallow resistivity with high resistance; below 4360m, the reservoir shows a negative difference with low resistance, especially at depths of 4362.4 meters and 4371 meters, deep resistivity is only 2Ω.m, and the CAST-V imaging map shows that there are low resistance substances contained in the pores or matrix in the reservoirs of this interval. The rock slice analysis data shows that the pyrite volume is 2-3% in the interval 4369.08m-4371.55m. A comprehensive analysis on the volume of shale (Vsh), porosity, invasion features of resistivity, mud logging, and mineral volume indicates that the possible causes for the negative difference between deep and shallow resistivities with relatively low resistance are erosional pores, caves, micritic texture and the presence of pyrite. Full-bore Drill Stem Test (DST) verified 4991.09 bbl/d in this interval. To identify and thoroughly characterize low resistivity intervals coring, Nuclear Magnetic Resonance (NMR) logging and further geological evaluation are needed.

Keywords: low resistivity pay, carbonates petrophysics, microporosity, porosity

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Authors: Mengesha Mamo Wogari

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In this paper, low voltage multiphase brushless DC motor with square wave air-gap flux distribution for electric vehicle application is proposed. Ten-phase, 5 kW motor, has been designed and simulated by finite element methods demonstrating the desired high torque capability at low speed and flux weakening operation for high-speed operations. The motor torque is proportional to number of phases for a constant phase current and air-gap flux. The concept of vector control and simple space vector modulation technique is used on MATLAB to control the motor demonstrating simple switching pattern for selected number of phases. The low voltage DC and inverter output AC are desired characteristics to avoid any electric shock in the vehicle, accidentally and during abnormal conditions. The switching devices for inverter are of low-voltage rating and cost effective though their number is equal to twice the number of phases.

Keywords: brushless DC motors, electric Vehicle, finite element methods, Low-voltage inverter, multiphase

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Authors: Coulibaly Fatoumata, Seme Kpassi, Aboly Nicolas, Ccoulibaly Zonzereke

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Introduction and Objective: Microbial resistance is nowadays a major public health problem. In the perspective of a better understanding of the resistance of ticks against acaricides, a study was conducted in the Department of Korhogo. The general objective was to verify the knowledge and skills of breeders on the use of acaricides and contribute to reducing the impact of ticks on livestock productivity. Methodology: To carry out the work, a cross-sectional survey was conducted using elaborate questionnaires, followed by specific interviews with livestock stakeholders in the Korhogo sub-prefecture. Results: The results showed that in the study area, cattle breeders, the majority of whom (58.06%) are Ivorians, use anti-ticks without strict compliance with recommendations of the instructions and standards for use. 68% of them performed under-dosed treatments, and 32% an over-dosed treatment. The most common method for treating cattle against ticks was spraying. Conclusion: Despite the use of tick repellents by these breeders, tick-borne diseases still persist. This could be explained by the misuse of the products (under dosage and overdose), which can cause harmful effects or even resistance of certain ticks. It is, therefore important to respect the normal dosage of the products used as well as the methods of use (bath, spray, pour-on, etc.). In order to minimize the problems of resistance, awareness is necessary among breeders for the proper use of acaricidal products as well as all other drugs.

Keywords: ticks, resistance, anti-tick, cattle, korhogo

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Authors: Annamária Käferné Rácz, Bence Jáger, Balázs Kövesdi, László Dunai

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Due to the numerous advantages of steel corrugated web girders, its application field is growing for bridges as well as for buildings. The global stability behavior of such girders is significantly larger than those of conventional I-girders with flat web, thus the application of the structural steel material can be significantly reduced. Design codes and specifications do not provide clear and complete rules or recommendations for the determination of the lateral torsional buckling (LTB) resistance of corrugated web girders. Therefore, the authors made a thorough investigation regarding the LTB resistance of the corrugated web girders. Finite element (FE) simulations have been performed to develop new design formulas for the determination of the LTB resistance of trapezoidally corrugated web girders. FE model is developed considering geometrical and material nonlinear analysis using equivalent geometric imperfections (GMNI analysis). The equivalent geometric imperfections involve the initial geometric imperfections and residual stresses coming from rolling, welding and flame cutting. Imperfection sensitivity analysis was performed to determine the necessary magnitudes regarding only the first eigenmodes shape imperfections. By the help of the validated FE model, an extended parametric study is carried out to investigate the LTB resistance for different trapezoidal corrugation profiles. First, the critical moment of a specific girder was calculated by FE model. The critical moments from the FE calculations are compared to the previous analytical calculation proposals. Then, nonlinear analysis was carried out to determine the ultimate resistance. Due to the numerical investigations, new proposals are developed for the determination of the LTB resistance of trapezoidally corrugated web girders through a modification factor on the design method related to the conventional flat web girders.

Keywords: corrugated web, lateral torsional buckling, critical moment, FE modeling

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Authors: Shivan Sirdy

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In this study, we discuss the properties of absolute void space or the universe at zero seconds, and how these properties play a vital role in creating a mechanism in which the very first particle gets created simultaneously everywhere. We find the limit in which when the absolute void volume reaches will lead to the collapse that leads to the creation of the first particle. This discussion is made following the elementary dimensions theory study that was peer-reviewed at the end of 2020; everything in the universe is made from four elementary dimensions, these dimensions are the three spatial dimensions (X, Y, and Z) and the Void resistance as the factor of change among the four. Time itself was not considered as the fourth dimension. Rather time corresponds to a factor of change, and during the research, it was found out that the Void resistance is the factor of change in the absolute Void space, where time is a hypothetical concept that represents changes during certain events compared to a constant change rate event. Therefore, time does exist, but as a factor of change as the Void resistance: Time= factor of change= Void resistance.

Keywords: elementary dimensions, absolute void, time alternative, early universe, universe at zero second, Void resistant, Hydrogen atom, Hadron field, Lepton field

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Authors: Zeynep Yazgan, Gökhan Aygün, Reyhan Çalışkan

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Objective: Invasive fungal infections are a serious threat in terms of morbidity and mortality, especially in immunocompromised patients. The most frequently isolated agents are Aspergillus genus fungi, and sensitivity to azoles, which are the first choice in treatment, decreases. In our study, we aimed to investigate the use of the agar plate screening method as a fast, easy, and practical method in determining azole resistance in Aspergillus spp. species. Methods: Our study was conducted with 125 Aspergillus spp. isolates produced from various clinical samples. Aspergillus spp. isolates were identified by conventional methods and azole resistance was determined by gradient test and agar plate screening method. Broth microdilution method was applied to resistant isolates, and CypA-L98H and CypA-M220 mutations in the cyp51A gene were investigated. Results: In our study, 55 A. fumigatus complex (44%), 42 A. flavus (33.6%), 6 A. terreus (5%), 4 A. niger (3%) and 18 Aspergillus spp. (14%) were identified. With the gradient test method, resistance to VOR and POS was detected in 1 (1.8%) of A.fumigatus isolates, and resistance to ITR was detected in 3 (5.45%). With the agar plate method, 1 of the A.fumigatus isolates (1.8%) had VOR, ITR, POS, 1 of the A.terreus isolates (16.7%) had VOR, 1 of the A.niger isolates (25%) had ITR. Resistance to VOR and POS was detected in 2 Aspergillus spp. isolates (11%), and resistance to ITR was detected in 1 (5.6%). Sensitivity and specificity were determined as 100% for VOR and POS in A. fumigatus species, 33.3% and 100% for ITR, respectively, 100% for ITR in A. flavus species, and 100% for ITR and POS in A. terreus species. By broth microdilution method in 7 isolates in which resistance was detected by gradient test and/or agar plate screening method; 1 A.fumigatus resistant to ITR, VOR, POS, 2 A.fumigatus resistant to ITR, 2 Aspergillus spp. ITR, VOR, POS MICs were determined as 2µg/ml and 8µg/ml, 8µg/ml and >32µg/ml, 0.5µg/ml and 4µg/ml, respectively. CypA-L98H mutations were detected in 5 of these isolates, CypA-M220 mutations were detected in 6, and no mutation was detected in 1. CypA-L98H and CypA-M220 mutations were detected in 1 isolate for which resistance was not detected. Conclusion: The need for rapid antifungal susceptibility screening tests is increasing in the treatment of aspergillosis. Although the sensitivity of the agar plate method was determined to be 33.3% for A.fumigatus ITR in our study, its sensitivity and specificity were determined to be 100% for ITR, VOR, and POS in other species. The low sensitivity value detected for A.fumigatus showed that agar plate drug concentrations should be updated in accordance with the latest regulations of EUCAST guidelines. The CypA-L98H and CypA-M220 mutations detected in our study suggested that the distribution of azole resistance-related mutations in different regions in our country should be investigated. In conclusion, it is thought that the agar plate method, which can be easily applied to detect azole resistance, is a fast and practical method in routine use and can contribute to both the determination of effective treatment strategies and the generation of epidemiological data.

Keywords: Aspergillus, agar plate, azole resistance, cyp51A, cypA-L98H, cypA-M220

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Authors: Anthony Ayodeji Adegoke, Olayinka Ayobami Aiyegoro, Thor Axel Stenstrom

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A study to investigate the species diversities, antibiogram and antibiotic resistance genes in Staphylococcus species from raw meat and dairy products collected from an abattoir and a farm shop of a research institute in Irene, South Africa over a six-month period was conducted. Polymerase Chain Reaction was used to speciate the bacteria and to detect the presence and otherwise of resistance genes. Antibiotic susceptibility testing was performed by disk diffusion method on Mueller-Hinton agar according to the Clinical Laboratory Standards Institute standards. A total of twenty-six (26) antibiotics were used to determine the antibiotic susceptibility. S. xylosus was the predominant isolate with 30% total occurrence, followed by S. epidermis, S. aureus, S. saprophyticus and S. haemolyticus with 25%, 15%, 15%, and 10% abundance respectively. The isolates were resistant to ceftezidime, gentamycin, nalidixic acid, nortrafuration, ampicillin, penicillin, oxytetracycline, tetracycline, doxycycline, clindamycin and lincomycin. mecA genes was detected among the methicillin resistant Staphylococcus species (MRSS) but no vancomycin resistance genes (van A and van B) were detected in these isolates. The presence of MRSS and multidrug resistant Staphylococcus species in meat affirms the need to avoid consumption of partially cooked meat currently rampant in South Africa, to avoid the spread of difficult to control pathogens in epidemiological proportion.

Keywords: Staphylococcus species, antibiotics, antibiotic resistance genes, food products, methicillin resistance, mecA gene

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Authors: Chun-Ying Lee, Mei-Wen Wu, Li-Yi Cheng, Chiang-Ho Cheng

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This research studies the electroplating of zinc coating in the zinc chloride bath mixed with supercritical CO2. The sodium fluoride (NaF) was used as the bath additive to change the structure and property of the coating, and therefore the roughness and corrosion resistance of the zinc coating was investigated. The surface characterization was performed using optical microscope (OM), X-ray diffractometer (XRD), and α-step profilometer. Moreover, the potentiodynamic polarization measurement in 3% NaCl solution was employed in the corrosion resistance evaluation. Because of the emulsification of the electrolyte mixed in Sc-CO2, the electroplated zinc produced the coating with smoother surface, smaller grain, better throwing power and higher corrosion resistance. The main role played by the NaF was to reduce the coating’s roughness and grain size. In other words, the CO2 mixed with the electrolyte under the supercritical condition performed the similar function as brighter and leveler in zinc electroplating to enhance the throwing power and corrosion resistance of the coating.

Keywords: supercritical CO2, zinc-electroplating, sodium fluoride, electroplating

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Authors: Neha Bharti, Martin Sénéchal, Danielle R. Bouchard

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Mostly attributed to lack of time, only 15% of adults currently reach the International Physical Activity Guidelines, which state that every adult should achieve minimum of 150 minutes of aerobic exercise per week at moderate to vigorous intensity in minimum bouts of 10 minutes each, in addition to two days of resistance training. Recent studies have suggested that any bout of aerobic exercise reaching moderate intensity has potential to improve health. If one could reach moderate intensity while doing resistance training, this could reduce the total weekly time involvement to reach the International Physical Activity Guidelines. Objectives: 1) To determine whether overweight and older adults can reach a minimum of moderate intensity while doing resistance training compared with young non-overweight adults, 2) To identify if the proportion of time spent at moderate to vigorous intensity is different in overweight adults and older adults when compared with young non-overweight adults when lifting 70% or 80% of maximal load, 3) To determine variables associated with proportion of time spent at moderate to vigorous intensity while doing resistance training. Methods: Sixty participants already doing resistance training were recruited (20 young non-overweight adults, 20 overweight adults, and 20 older adults). Participants visited fitness facility three times, separated by at least 48 hours, and performed eight resistance exercises each time. First visit was to collect baseline measurements and to measure maximal load for each of the eight exercises. Second and third visits were performed wearing a heart rate monitor to record heart rate and to measure exercise intensity. The two exercise sessions were performed at 70% and 80% of maximal capacity. Moderate intensity was defined as 40% of heart rate reserve. Results: The proportion of time spent at moderate to vigorous intensity ranged from 51% to 93% among the three groups. No difference was observed between the young group and the overweight adults group in the proportion of time spent at moderate to vigorous intensity, 82.6% (69.2-94.6) vs 92.5% (73.3-99.1). However, older adults spent lower proportion of time at moderate to vigorous intensity for both sessions 51.5% (22.0-86.6); P < .01. When doing resistance training at 70% and 80% of maximal capacity, the proportion of time spent at moderate to vigorous intensity was 82.3% (56.1-94.7) and 82.0% (59.2-98.0) with no significant difference (P=.83). Conclusion: This study suggests that overweight adults and older adults can reach moderate intensity for at least 51% of the time spent doing resistance training. However, time spent at moderate to vigorous intensity was lower for older adults compared to young non-overweight adults. For adults aged 60 or less, three resistance training sessions of 60 minutes weekly could be enough to reach both aerobic and resistance training components of the International Physical Activity Guidelines. Further research is needed to test if resistance training at moderate to vigorous intensity can have the same health benefits compared with adults completing the International Physical Activity Guidelines as currently suggested.

Keywords: aerobic exercise, international physical activity guidelines, moderate to vigorous intensity, resistance training

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Authors: Yegnanew A. Shiferaw

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Background: commodity price volatility originating from excessive commodity price fluctuation has been a global problem especially after the recent financial crises. Volatility is a measure of risk or uncertainty in financial analysis. It plays a vital role in risk management, portfolio management, and pricing equity. Objectives: the core objective of this paper is to examine the relationship between the prices of agricultural commodities with oil price, gas price, coal price and exchange rate (USD/Rand). In addition, the paper tries to fit an appropriate model that best describes the log return price volatility and estimate Value-at-Risk and expected shortfall. Data and methods: the data used in this study are the daily returns of agricultural commodity prices from 02 January 2007 to 31st October 2016. The data sets consists of the daily returns of agricultural commodity prices namely: white maize, yellow maize, wheat, sunflower, soya, corn, and sorghum. The paper applies the three-state Markov-switching (MS) regression, the standard single-regime GARCH and the two regime Markov-switching GARCH (MS-GARCH) models. Results: to choose the best fit model, the log-likelihood function, Akaike information criterion (AIC), Bayesian information criterion (BIC) and deviance information criterion (DIC) are employed under three distributions for innovations. The results indicate that: (i) the price of agricultural commodities was found to be significantly associated with the price of coal, price of natural gas, price of oil and exchange rate, (ii) for all agricultural commodities except sunflower, k=3 had higher log-likelihood values and lower AIC and BIC values. Thus, the three-state MS regression model outperformed the two-state MS regression model (iii) MS-GARCH(1,1) with generalized error distribution (ged) innovation performs best for white maize and yellow maize; MS-GARCH(1,1) with student-t distribution (std) innovation performs better for sorghum; MS-gjrGARCH(1,1) with ged innovation performs better for wheat, sunflower and soya and MS-GARCH(1,1) with std innovation performs better for corn. In conclusion, this paper provided a practical guide for modelling agricultural commodity prices by MS regression and MS-GARCH processes. This paper can be good as a reference when facing modelling agricultural commodity price problems.

Keywords: commodity prices, MS-GARCH model, MS regression model, South Africa, volatility

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Authors: Mohamed M. Shahin

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This study investigated the design of the pile foundation to support heavy structures-especially bridges for highways-in the Sahara, which contains many dunes of medium dense sand in different levels, where the foundation is supposed to be piles. The base resistance of smooth model pile groups in sand under static loading is investigated experimentally in a pile soil test apparatus. Improvement were made to the sand around the piles in order to increase the shaft resistance of the single pile and the pile groups, and also base resistance especially for the central pile in pile groups. The study outlines the behaviour of a single-pile, 4-, 5-, and 9- pile groups arranged in a doubly symmetric [square] layout with different embedment lengths and pile spacing in loose dry sand [normal] and dense dry sand [compacted] around the piles. This study evaluate the variation of the magnitude and the proportion of end bearing capacity of individual piles in different pile groups. Also to investigate the magnitude of the efficiency coefficient in the case of different pile groups.

Keywords: pile group, base resistance, efficiency coefficient, pile spacing, pile-soil interaction

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Authors: Harche Rima, Laoufi Nadia Aicha

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This work focuses on the study and modeling of the fouling phenomenon in a vertical pipe. In the first step, milk is one of the fluids obeying the phenomenon of fouling because of the denaturation of these proteins, especially lactoglobulin, which is the active element of milk, and to facilitate its use, we chose to study milk as a fouling fluid. In another step, we consider the test section of our installation as a tubular-type heat exchanger that works against the current and in a closed circuit. A simple mathematical model of Kern & Seaton, based on the kinetics of the fouling resistance, was used to evaluate the influence of the operating parameters (fluid flow velocity and exchange wall temperature) on the fouling resistance. The influence of the variation of the fouling resistance with the operating conditions on the efficiency of the heat exchanger and the importance of the dirty state exchange coefficient as an exchange quality control parameter were discussed and examined. On the other hand, an electronic scanning microscope analysis was performed on the milk deposit in order to obtain its actual image and composition, which allowed us to calculate the thickness of this deposit.

Keywords: fouling, milk, tubular heat exchanger, fouling resistance

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Authors: Tu-Chieh Hung, Wei-Mon Yan, Xiao-Dong Wang, Yu-Xian Huang

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This work employs a combined optimization procedure including a simplified conjugate-gradient method and a three-dimensional fluid flow and heat transfer model to study the optimal geometric parameter design of double-layered microchannel heat sinks. The overall thermal resistance RT is the objective function to be minimized with number of channels, N, the channel width ratio, β, the bottom channel aspect ratio, αb, and upper channel aspect ratio, αu, as the search variables. It is shown that, for the given bottom area (10 mm×10 mm) and heat flux (100 W cm-2), the optimal (minimum) thermal resistance of double-layered microchannel heat sinks is about RT=0.12 ℃/m2W with the corresponding optimal geometric parameters N=73, β=0.50, αb=3.52, and, αu= 7.21 under a constant pumping power of 0.05 W. The optimization process produces a maximum reduction by 52.8% in the overall thermal resistance compared with an initial guess (N=112, β=0.37, αb=10.32 and, αu=10.93). The results also show that the optimal thermal resistance decreases rapidly with the pumping power and tends to be a saturated value afterward. The corresponding optimal values of parameters N, αb, and αu increase while that of β decrease as the pumping power increases. However, further increasing pumping power is not always cost-effective for the application of heat sink designs.

Keywords: optimization, double-layered microchannel heat sink, simplified conjugate-gradient method, thermal resistance

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Authors: Keerthi S. Shetty, Annappa Basava

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In recent years, modelling of biological systems represented by biochemical reactions has become increasingly important in Systems Biology. Biological systems represented by biochemical reactions are highly stochastic in nature. Probabilistic model is often used to describe such systems. One of the main challenges in Systems biology is to combine absolute experimental data into probabilistic model. This challenge arises because (1) some molecules may be present in relatively small quantities, (2) there is a switching between individual elements present in the system, and (3) the process is inherently stochastic on the level at which observations are made. In this paper, we describe a novel idea of combining absolute experimental data into probabilistic model using tool R2. Through a case study of the Transcription Process in Prokaryotes we explain how biological systems can be written as probabilistic program to combine experimental data into the model. The model developed is then analysed in terms of intrinsic noise and exact sampling of switching times between individual elements in the system. We have mainly concentrated on inferring number of genes in ON and OFF states from experimental data.

Keywords: systems biology, probabilistic model, inference, biology, model

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Authors: Mehrak Zargaryaeghoubi, Masood Hajali

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Drilled shafts are the most popular of deep foundations, because they have the capability that one single shaft can easily carry the entire load of a large column from a bridge or tall building. Drilled shaft may be an economical alternative to pile foundations because a pile cap is not needed, which not only reduces that expense, but also provides a rough surface in the border of soil and concrete to carry a more axial load. Due to the larger construction sizes of drilled shafts, they have an excellent axial load carrying capacity. Part of the axial load carrying capacity of the drilled shaft is resisted by the soil below the tip of the shaft which is tip resistance and the other part is resisted by the friction developed around the drilled shaft which is side resistance. The condition at the bottom of the excavation can affect the end bearing capacity of the drilled shaft. Also, type of the soil and size of the drilled shaft can affect the frictional resistance. The main loads applied on the drilled shafts are axial compressive loads. It is important to know how many percent of the maximum applied load will be shed inside friction and how much will be transferred to the base. The axial capacity of the drilled shaft foundation is influenced by the size of the drilled shaft, and soil characteristics. In this study, the effect of the size and soil characteristic will be investigated on the contribution of side resistance and end-bearing capacity. Also, the study presents a three-dimensional finite element modeling of a drilled shaft subjected to axial load using ANSYS. The top displacement and settlement of the drilled shaft are verified with analytical results. The soil profile is considered as Table 1 and for a drilled shaft with 7 ft diameter and 95 ft length the stresses in z-direction are calculated through the length of the shaft. From the stresses in z-direction through the length of the shaft the side resistance can be calculated and with the z-direction stress at the tip, the tip resistance can be calculated. The result of the side and tip resistance for this drilled shaft are compared with the analytical results.

Keywords: Drilled Shaft Foundation, size and soil characteristic, axial load capacity, Finite Element

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Authors: R. Rahmoun-Mrabet

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It is acknowledged that our style of speaking changes according to a wide range of variables such as gender, setting, the age of both the addresser and the addressee, the conversation topic, and the aim of the interaction. These differences in style are noticeable in monolingual and multilingual speech communities. Yet, they are more observable in speech communities where two or more codes coexist. The linguistic situation in Algeria reflects a state of bilingualism because of the coexistence of Arabic and French. Nevertheless, like all Arab countries, it is characterized by diglossia i.e. the concomitance of Modern Standard Arabic (MSA) and Algerian Arabic (AA), the former standing for the ‘high variety’ and the latter for the ‘low variety’. The two varieties are derived from the same source but are used to fulfil distinct functions that is, MSA is used in the domains of religion, literature, education and formal settings. AA, on the other hand, is used in informal settings, in everyday speech. French has strongly affected the Algerian language and culture because of the historical background of Algeria, thus, what can easily be noticed in Algeria is that everyday speech is characterized by code-switching from dialectal Arabic and French or by the use of borrowings. Tamazight is also very present in many regions of Algeria and is the mother tongue of many Algerians. Yet, it is not used in the west of Algeria, where the study has been conducted. The present work, which was directed in the speech community of Tlemcen-Algeria, aims at depicting some of the outcomes of the contact of Arabic with French such as code-switching, borrowing and interference. The question that has been asked is whether Algerians are aware of their use of borrowings or not. Three steps are followed in this research; the first one is to depict the sociolinguistic situation in Algeria and to describe the linguistic characteristics of the dialect of Tlemcen, which are specific to this city. The second one is concerned with data collection. Data have been collected from 57 informants who were given questionnaires and who have then been classified according to their age, gender and level of education. Information has also been collected through observation, and note taking. The third step is devoted to analysis. The results obtained reveal that most Algerians are aware of their use of borrowings. The present work clarifies how words are borrowed from French, and then adapted to Arabic. It also illustrates the way in which singular words inflect into plural. The results expose the main characteristics of borrowing as opposed to code-switching. The study also clarifies how interference occurs at the level of nouns, verbs and adjectives.

Keywords: bilingualism, borrowing, code-switching, interference, language contact

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Authors: Zikora K. G. Anyaegbunam, Annabel A. Nnawuihe, Ngozi J. Anyaegbunam, Emmanuel A. Eze

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The discovery and production of new antibiotics is unavoidable in the fight against drug-resistant bacteria. However, this is only part of the problem; we have never really had medications that could completely eradicate an infection. All pathogens create a limited number of dormant persister cells that are resistant to antibiotic treatment. When the concentration of antibiotics decreases, surviving persisters repopulate the population, resulting in a recurrent chronic infection. Bacterial populations have an alternative survival strategy to withstand harsh conditions or antibiotic exposure, in addition to the well-known methods of antibiotic resistance and biofilm formation. Persister cells are a limited subset of transiently antibiotic-tolerant phenotypic variations capable of surviving high-dose antibiotic therapy. Persisters that flip back to a normal phenotype can restart growth when antibiotic pressure drops, assuring the bacterial population's survival. Persister cells have been found in every major pathogen, and they play a role in antibiotic tolerance in biofilms as well as the recalcitrance of chronic infections. Persister cells has been implicated to play a role in the establishment of antibiotic resistance, according to growing research. Thusthe need to basically elucidate the biology of persisters and how they are linked to antibiotic resistance, and as well it's link to diseases.

Keywords: persister cells, phenotypic variations, repopulation, mobile genetic transfers, antibiotic resistance

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Authors: Afroza Akhter Tina

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This paper reports on an investigation into the use of specific types of oral communication strategies, namely ‘topic avoidance’, ‘message abandonment’, ‘code-switching’, ‘paraphrasing’, ‘restructuring’, and ‘stalling’ by Bangladeshi EFL learners at the graduate level. It chiefly considers the frequency of using these strategies as well as the students and teachers attitudes toward such uses. The participants of this study are 66 EFL students and 12 EFL teachers of Jahangirnagar University. Data was collected through questionnaire, oral interview, and classroom observation form. The findings reveal that the EFL students tried to employ all the strategies to various extents due to the language difficulties they encountered in their oral English performance. Among them, the mostly used strategy was ‘stalling’ or the use of fillers, followed by ‘code-switching’. The least used strategies were ‘topic avoidance’, ‘restructuring’, and ‘paraphrasing’. The findings indicate that the use of such strategies was related to the contexts of situation and data-elicitation tasks. It also reveals that the students were not formally trained to use the strategies though the majority of the teachers and students acknowledge them as helpful in communication. Finally the study suggests that an awareness of the nature and functions of these strategies can contribute to the overall improvement of the learners’ communicative competence in spoken English.

Keywords: communicative strategies, competency, attitude, frequency

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Authors: Osamu Igawa, Hiroshi Kouchiwa, Yuji Ito

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In recent years, a reconstruction project for sewer pipelines has been progressing in Japan with the aim of renewing old sewer culverts. However, it is difficult to secure a sufficient base area for shafts in an urban area because many streets are narrow with a complex layout. As a result, construction in such urban areas is generally very demanding. In urban areas, there is a strong requirement for a safe, reliable and economical construction method that does not disturb the public’s daily life and urban activities. With this in mind, we developed a new construction method called the 'shield switching type micro-tunneling method' which integrates the micro-tunneling method and shield method. In this method, pipeline is constructed first for sections that are gently curved or straight using the economical micro-tunneling method, and then the method is switched to the shield method for sections with a sharp curve or a series of curves without establishing an intermediate shaft. This paper provides the information, features and construction examples of this newly developed method.

Keywords: micro-tunneling method, secondary lining applied RC segment, sharp curve, shield method, switching type

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Authors: F. Sangiorgio, J. Silfwerbrand, G. Mancini

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Geometric and mechanical properties all influence the resistance of RC structures and may, in certain combination of property values, increase the risk of a brittle failure of the whole system. This paper presents a statistical and probabilistic investigation on the resistance of RC beams designed according to Eurocodes 2 and 8, and subjected to multiple failure modes, under both the natural variation of material properties and the uncertainty associated with cross-section and transverse reinforcement geometry. A full probabilistic model based on JCSS Probabilistic Model Code is derived. Different beams are studied through material nonlinear analysis via Monte Carlo simulations. The resistance model is consistent with Eurocode 2. Both a multivariate statistical evaluation and the data clustering analysis of outcomes are then performed. Results show that the ultimate load behaviour of RC beams subjected to flexural and shear failure modes seems to be mainly influenced by the combination of the mechanical properties of both longitudinal reinforcement and stirrups, and the tensile strength of concrete, of which the latter appears to affect the overall response of the system in a nonlinear way. The model uncertainty of the resistance model used in the analysis plays undoubtedly an important role in interpreting results.

Keywords: modelling, Monte Carlo simulations, probabilistic models, data clustering, reinforced concrete members, structural design

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Authors: Mingxi Xiao

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This case study focused on a bilingual child named Emma and her play. Emma was a four-year-old girl born in Australia while her parents were both Chinese. Emma could speak fluent English, while her Mandarin was not as good as her spoken English. With the research question to figure out whether creative play had an impact on children’s bilingualism, this case study mainly used the anecdotes method to observe Emma’s play and this report presented five observations of Emma, describing detailed information about her play and recording her language use. Based on Emma’s interests and daily activities, this case study chose her creative play for observation, which incorporates a whole range of activities from dancing to drawing, as well as playing instruments. From the five observations, it could be seen that Emma often mixed languages to help her express her meaning. It could be seen that Emma made an effort to use her bilingualism in her creative play. In other words, play encouraged Emma to use the two languages. In conclusion, the observations with Emma showed that although her Mandarin was not good enough, she displayed confidence in speaking both languages and had gradually shifted from mixing languages to code-switching. Recommendations were provided to support Emma’s bilingual abilities for further development in the end.

Keywords: bilingual, case study, code-switching, creative play, early childhood

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Authors: Annet Namusoke, Annet Namayanja, Peter Wasswa, Shakirah Nampijja

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Common bean cultivar G2333 which offers broad resistance for anthracnose has been widely used as a source of resistance in breeding for anthracnose resistance. The cultivar is pyramided with three genes namely CO-4, CO-5 and CO-7 and of these three genes, the CO-4 gene has been found to offer the broadest resistance. The main aim of this work was to identify and validate easily assayable PCR based co-dominant molecular markers for selection of the CO-4 gene in segregating populations derived from crosses of G2333 with RWR 1946 and RWR 2075, two commercial Andean cultivars highly susceptible to anthracnose. Marker sequences for the study were obtained by blasting the sequence of the COK-4 gene in the Phaseolus gene database. Primer sequence pairs that were not provided from the Phaseolus gene database were designed by the use of Primer3 software. PCR conditions were optimized and the PCR products were run on 6% HPAGE gel. Results of the polymorphism test indicated that out of 18 identified markers, only two markers namely BM588 and BM211 behaved co-dominantly. Phenotypic evaluation for reaction to anthracnose disease was done by inoculating 21days old seedlings of three parents, F1 and F2 populations with race 7 of Colletotrichum lindemuthianum in the humid chamber. DNA testing of the BM588 marker onto the F2 segregating population of the crosses RWR 1946 x G 2333 and RWR 2075 x G2333 further revealed that the marker BM588 co-segregated with disease resistance with co-dominance of two alleles of 200bp and 400bp, fitting the expected segregation ratio of 1:2:1. The BM588 marker was significantly associated with disease resistance and gave promising results for marker assisted selection of the CO-4 gene in the breeding lines. Activities to validate the BM211 marker are also underway.

Keywords: codominant, Colletotrichum lindemuthianum, MAS, Phaseolus vulgaris

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