443 research outputs found

    Study of the baiE Gene in Bile Acid 7α-Dehydroxylating Bacteria

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    Intestinal bile acid 7α-dehydroxylating bacteria have recently been implicated in cholesterol allstone disease. Eubacterium sp. V.P.I. 12708, a bile acid 7α-dehydroxylating bacterium, contains multiple bile acid inducible (bai) genes which encode the enzymes responsible for bile acid 7a-dehydroxylation. The baiE gene encodes a bile acid dehydratase activity in Eubacterium sp.V.P.I. 12708. Using the polymerase chain reaction assay we determined the presence or absence of baiE-like genes in five clostridial bile-acid 7α-dehydroxylating strains: Clostridium sp. TO-931, Clostridium sp. HD-17, Clostridium sp. TN-271, Clostridium bifermentans 1-55, and Clostridium sordellii ATCC 9714. Results from all the strains tested showed amplification at the predicted DNA fragment size. Partial DNA sequence analysis of the amplified baiE-like genes revealed 88-95% homology with the baiE gene of Eubacterium sp.V.P.I. 12708. These data suggest that baiE-like genes are present in the five bile acid 7α-dehydroxylating strains studied

    Sorption of N2, Co2 and CH4 On the ultrasound enhanced cation exchanged x zeolites

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    Thesis (Doctoral)--Izmir Institute of Technology, Chemical Engineering, Izmir, 2011Includes bibliographical references (leaves: 133-140)Text in English; Abstract: Turkish and Englishxv, 169 leavesLi+, Ca2+ and Ce3+ ions exchange on NaX zeolite under ultrasonic irradiation and the N2, CO2 and CH4 sorption on the zeolites obtained by using Zero Length Coulumn (ZLC) technique were studied. The kinetic and equilibrium of ion exchange were applied in the concentration range of 3-9 fold equivalent excess at 50 oC and 70 oC. The results obtained from the ultrasonic method was compared with the traditional method. Maximum exchange percent was obtained under ultrasonic irradiation as 76, 72 and 66 for Li+, Ca2+ and Ce3+ ions exchange, respectively. The kinetics of the ion exchange of Li+, Ca2+, Ce3+ ions into NaX zeolite has been investigated with models; pseudo first order, pseudo second order reaction models, intraparticle and external diffusion models. At initial, ion exchange is very fast kinetically and completed within about 15 min. After that both mechanism: intraparticle and external resistance are dominant which are proved with Biot number. The experimental conditions in zero length column are adjusted to control the adsorption under diffusion. The adsorbents selected for adsorption in ZLC have the convenient average pore diameters for CO2, N2 and CH4 adsorption. The kinetic gas selectivities, S(CO2/CH4), S(CO2/N2), S(N2/CH4) at 30 oC, 60 oC and 90 oC are lower than 5 for all the adsorbents. The lowest selectivity is obtained for NaX zeolite. The CO2 selectivity over CH4 and N2 are higher than N2 selectivity over CH4 for all the adsorbents S(CO2/CH4), S(CO2/N2) S(N2/CH4). This can be explained with the high electrostatic interaction and the low kinetic diameter of CO2 than the other gases

    Matematik Öğretmenlerinin Öğrenen Tarafından Üretilen Örnekleri Sınıfta Kullanma Sıklıklarının ve Gerekçelerinin İncelenmesi

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    In the classroom, examples are typically presented by the teacher and students try to improve their understanding of the relevant concept by examining the given examples. In addition to use in this way, example generation is defined as a problem-solving activity in which individuals can develop different strategies. In recent studies, it has been considered a pedagogical method as well as a research tool. The purpose of this study is to investigate high school mathematics teachers’ usage frequency of learner generated examples (LGEs) and to reveal the reasons behind them. The sample consisted of 196 high school teachers, with different year of mathematics teaching experiences (ranging between 1 and 36 years). Data were collected using an instrument consisting of strategies that were brought together as a list by Watson and Mason (2005) and used by researcher in order to reveal teachers’ LGE usage frequency. The relationships between the frequency of use of LGE, the year of mathematics teaching experience of the teachers, and the type of high school they work, were investigated by using regression analysis. Additionally, 16 semi-structured interviews were conducted with voluntary teachers in order to obtain in-depth knowledge about their LGE usage frequency. The highest mean score for usage frequency belongs to teachers with 21 years and above mathematics teaching experience, whereas the lowest score belongs to teachers with 6-10 years mathematics teaching experience. Science high school teachers have the highest mean score for LGE usage frequency, whereas vocational high school teachers have the lowest score. However, only ‘year of mathematics teaching experience’ has a significant, unique contribution to the prediction of LGE usage frequency. Analysis of the qualitative data revealed that constraints related to students, educational policies, parents, topics, classroom environments, and teachers’ belief and attitudes have considerable effect on teachers’ example usage frequency. Also, their knowledge of content and student, along with knowledge of content and teaching, affect LGE usage.Örnekler sınıf içinde, genellikle öğretmen tarafından sunulmakta, öğrenciler ise verilen örnekleri inceleyerek ilgili kavrama ilişkin anlamalarını geliştirmeye çalışmaktadırlar. Örneklerin bu şekilde kullanımlarına ek olarak örnek üretme, bireylerin farklı stratejiler geliştirebileceği bir problem çözme aktivitesi olarak tanımlanmaktadır. Son yıllarda yapılan çalışmalarda örnek üretme hem pedagojik bir yöntem hem de bir araştırma aracı olarak ortaya çıkmıştır. Bu çalışmanın amacı, lise matematik öğretmenlerinin öğrenciler tarafından üretilen örnekleri (bundan sonra kısaca öğrenci örnekleri denilecektir) kullanım sıklıklarını incelemek ve bu kullanım sıklığı arkasındaki nedenleri ortaya çıkarmaktır. Çalışmanın örneklemini fen lisesi, Anadolu lisesi, imam hatip lisesi ve meslek lisesinde çalışan ve yıl olarak farklı matematik öğretim deneyimine (1-36 yıl) sahip 196 matematik öğretmeni oluşturmaktadır. Çalışmanın verileri, Watson ve Mason (2005) tarafından bir strateji listesi olarak sunulup araştırmacı tarafından bir araya getirilerek öğretmenlerin öğrenci örneklerini kullanma sıklığını ortaya çıkarmak amacıyla oluşturulan bir envanter ile toplanmıştır. Öğretmenlerin çalıştıkları okul türlerinin ve matematik öğretimi deneyim yıllarının öğrenci örneklerini kullanma sıklıklarını anlamlı olarak yordayıp yordamadığını belirlemek için regresyon analizi kullanılmıştır. Ek olarak, 16 öğretmenle yarı yapılandırılmış görüşme gerçekleştirilmiştir. Çalışma sonunda en fazla öğrenci örneği kullanma sıklığının matematik öğretim deneyimi 21 yıl ve üstü olan öğretmenlere ait olduğu bulunurken, en düşük öğrenci örneği kullanma sıklığının matematik öğretim deneyimi 6-10 yıl arası olan öğretmenlere ait olduğu tespit edilmiştir. Fen lisesi öğretmenlerinin öğrenci örneği kullanma sıklığı en yüksek, meslek lisesi öğretmenlerinin öğrenci örneği kullanma sıklığı ise en düşük çıkmıştır. Ancak regresyon analizinde, sadece matematik öğretimi deneyim yılının öğrenci örneklerini kullanma sıklığına anlamlı katkı sağladığı belirlenmiştir. Nitel verilerin analizi sonucunda da öğrencilere, eğitim politikalarına, ailelere, konuya, sınıf ortamına ve öğretmenlerin inanç ve tutumlarına bağlı kısıtlamaların öğretmenlerin öğrenci örneklerini kullanma sıklığını etkilediği görülmüştür. Ayrıca öğretmenlerin, alan ve öğrenci ile alan ve öğretim hakkındaki bilgisi öğrenci örneklerini kullanmalarını etkilemektedir

    Perspectives in regard to factors affecting the professional development of science teachers

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    As one of the crucial elements of education system, teachers’ professional development is important to equip them with the education to compensate the needs of modern life. The major aim of this research is to determine the views of school principals and science teachers on the concept of professional development, and identify factors which affect science teachers’ professional development. Both qualitative (semi-structured interview) and quantitative (survey) research methods were used in the research. The sample consisted of school principals and science teachers who were working in Nevşehir province and its districts. 6 school principals and 6 science teachers were interviewed in-depthly. In addition, data from 109 science teachers were also collected through questionnaires. The data obtained through interviews were analyzed by descriptive analysis. Simple correlation technique and percentage distributions were used to analyze the questionnaires. The research findings show that in general, the teaching profession is being perceived as a profession which starts with pre-service training and continues with in-service training; therefore, it is an ongoing process. It has also been discovered that in this process, "personal and external factors" affect science teachers' professional development. Thus, teachers’ professional development should be supported in line with these factors

    The views concerning in-service teacher education courses in Science teachers' professional development

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    Cyprus International Conference on Educational Research (CY-ICER) -- FEB 08-11, 2012 -- Middle E Tech Univ No Cyprus Campus, CYPRUSWOS: 000342764800099The main aim of this research is to identify administrators' and science teachers' views regarding in-service teacher training courses. Semi-structured interviews and questionnaires have been utilized for collecting the data. The interviews were conducted with 6 head teachers (administrators) and 6 science teachers. A questionnaire developed by the researchers was conducted upon 109 teachers from seven primary schools. The results showed that there were discrepancies between the results of questionnaires and the interviews. In the questionnaires, most of the teachers indicated that the in-service training courses were helpful in their professional development. In the interviews, even though most of the head teachers found in-service training courses to be helpful in teachers' professional development, most of the teachers did not share the same opinion. Both the questionnaires and the interviews revealed some reported deficiencies and expectations from in-service training courses. (C) 2012 Published by Elsevier Ltd.Cyprus Educ Sci Assoc, Acad World Educ & Res Ctr, Near E Univ, Eastern Mediterranean Univ, Ataturk Teacher Training Acad, Int Cyprus Univ, Girne Amer Univ, Cyprus Educ Sci Asso

    Enhancement of cerium exchange with ultrasound

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    In this study the effect of ultrasound of the cerium exchange was studied. The results were compared to those obtained from traditional batch exchange method. Contact time, initial cation concentration (fold equivalent excess) and the types of the ultrasound were studied. Ultrasonic probe, which is the most effective method, enhanced the replacement of Na+ ion with Ce3+ ion in the extra-framework of zeolite up to 73 % by applying 5 consecutive ion exchanges. The cerium in the solution caused to be formed cerium oxides on the crystal surface occluding the pores. Thus the specific surface area of cerium exchanged zeolite was decreased due to formation of cerium complexes on the surface and into the pores. © 2018, Turkish Chemical Society. All rights reserved.Izmir Institute of Technology (Project number: 2006IYTE31) and State Planning Organization of Turkey (DPT

    Örgütsel Yaşamda Kişilik ve Performans İlişkisinde Pozitif Duygusallığın Aracı Rolü1 The Mediating Role Of Positive Affectivity In Relationship Between Personality And Performance

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    Bu çalışmanın amacı, beş faktör kişilik özellikleri (dışadönüklük, uzlaşmacılık, sorumluluk, duygusal denge, deneyime açıklık) ile görev ve bağlamsal performans ilişkisinde pozitif duygusallığın aracı rolünü belirlemektir. Bu amaçla hazırlanan çalışmada veri toplama tekniği olarak anket kullanılmıştır. Kolayda örnekleme yöntemi ile Kayseri Organize Sanayiinde faaliyette bulunan işletmelerde çalışan 457 kişiden veri toplanmıştır. Çalışanlardan kişilik, duygu ve performanslarına yönelik kendilerini değerlendirmeleri istenmiştir. Veriler korelasyon, regresyon ve aracı değişkenli regresyon analizleri yardımıyla incelenmiştir. Kişilik ile performans ilişkisinde pozitif duygusallığın aracılık etkisine yönelik yapılan regresyon analizi sonuçlarına göre, pozitif duygusallık; sorumluluk ile görev performansı ve bağlamsal performans; deneyime açıklık ile görev performansı ve bağlamsal performans ilişkisinde aracı bir rol üstlenmektedir. The purpose of this study is to determine the mediating effect of positive affectivity in relationship between big five personality characteristics (extraversion, conscientiousness, agreeableness, opennessto experience, emotional stability) and behavior (task performance, contextual performance). Questionnaire was used as data collection technique in survey. The questionnaire was responded by 457 participants of the Industrial Zone in Kayseri with convenience sampling method. People evaluated self-report about own personality, affect and performance. The data was examined with Pearson correlation, regression and mediated regression analysis. Mediated regression was used to test the hypotheses related to the constructs. According to the results of regression analysis that is displayed mediating effect of positive affectivity in relation between personality and behavior, there is mediating effect of positive affectivity in relationship between conscientiousness and task performance, contextual performance. Also, there is mediating effect of positive affectivity in relationship between openness to experience and task and contextual performance

    The relationship between frontal sinus dimensions and skeletal malocclusion

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    PurposeThe aim of this retrospective research is to compare frontal sinus dimensions in skeletal Class I, skeletal Class II, and skeletal Class III individuals and to evaluate the relationship of these dimensions with anterior skull base length and some cephalometric values.Materials and MethodsIn this research, we used lateral cephalometric radiographs of 60 people aged 17 to 25. In individuals with skeletal Class I malocclusion, skeletal Class II malocclusion due to mandibular insufficiency, and skeletal Class III malocclusion due to mandibular excess, measurements of frontal sinus length and height as well as S-N, Co-A and Co-Gn lengths, ANB0, FMA0, SN-GoGn0 angles values were performed. The length between the highest point and the lowest point of the frontal sinus was calculated as the height of the frontal sinus, and the length between the most anterior and the most posterior points of the frontal sinus was calculated as the length of the frontal sinus.ResultsThe frontal sinus length and height were found to be higher in skeletal Class III individuals than in skeletal Class I and skeletal Class II individuals, however, there was no significant difference between skeletal Class I and Class II individuals.ConclusionThe increase in frontal sinus height and length correlated positively with the decrease in the ANB angle and the increase in the SN and Co-Gn lengths. The dimensions of the frontal sinus may be an indicator for the remaining mandibular growth potential

    Fixed Orthodontic Retainers: A Review

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    Orthodontic retention is defined as maintaining teeth in optimal aesthetic and functional position after treatment. Despite the necessity of retention phase and the factors influencing the stability of the teeth after orthodontic treatment was discussed by the orthodontist for a long time, it is accepted that a retention phase is essential for stability of orthodontic treatment results nowadays. Therefore, the application of a suitable retention method is important both for prevention of relapse after orthodontic treatment and for increasing patient satisfaction. Removable appliances had been used for many years for retention purposes. Later, fixed retainers were introduced to prevent relapse as having a number of advantages, such as better aesthetics, no need for patient cooperation, effectiveness, and suitability for lifelong retention. However, their need for precise bonding technique, fragility, and tendency to cause periodontal problems by weakening oral hygiene are some of their disadvantages

    Katılım Bankaları Mevduat Bankalarından Farklı mı Çalışıyor

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    Bu araştırmanın temel amacı, Türkiye’de faaliyet gösteren mevduat ve katılım bankaların karşılaştırmalı analizini yapmak ve katılım bankalarının hangi alanlarda farklılaştığını irdelemektir. Bu çerçeve katılım bankacılığı için ifade edilen en önemli önermelerin sınanması amaçlanmaktadır. Bu önermelerden ilki katılım bankalarla geleneksel ticari bankalar arasında özkaynak açısından farklılığın bulunmasıdır. Diğer bir önemli önerme (veya ön kabul) ise, katılım bankalarının ile ticari bankalardan aktif kalitesi ve kârlılık açısından farklılık arz etmesidir. Çalışmada 2005-2012 döneminde Türkiye’de faaliyette bulunan mevduat bankaları ile katılım bankaları panel veri yöntemi ile incelenmiş ve katılım bankalarının daha yüksek özkaynakla çalışarak, finansal aracılık faaliyetlerine odaklanırken, diğer bankalardan etkinlik ve kârlılık açsından bir farklılık arz etmedikleridir. The main goal of this study is to conduct a comparative analysis between participation banks and deposit banks operating in Turkey and investigate the main areas of differentiation. In this context, the fundamental propositions are investigated. First off, the proposition that the participation banks operate with a differentiated capital adequacy structure is tested. Than the other presumption of that these peer groups differ from the asset quality and profitability perspective is analyzed. We examine the Turkish banking system for the 2005-2012 period. The mentioned propositions are tested using panel data analysis
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