Türk Öğrencilerin TIMSS 2007 ve 2011 Matematik Başarısında Öğrenci ve Öğretmen Özelliklerinin Etkileri

This study explores the relationship between student characteristics (perception regarding peer bullying, students’ confidence in mathematics, students’ like learning mathematics and students valuing mathematics) which affect mathematics achievement of eighth grade students in Turkey and teacher characteristics (working conditions of teachers, teacher’s emphasis on academic success and collaboration with colleagues in order to enhance teaching) which are dealt with at school level. In this correlational study, 141 teachers and 4498 students were included from the Trends in International Mathematics and Science Study (TIMSS) 2007 and 219 teachers and 6928 students were included from TIMSS 2011. Samples were created with the stratified sampling method. Data collection sources of the study consist of the mathematics achievement tests and student and teacher questionnaires that were used in TIMSS 2007 and 2011 assessments. Study data was analysed with the hierarchical linear modelling (HLM) method. Data for the study was analysed with four HLMs. These models are: (i) Random Effects One Way the Analysis of Variance (ANOVA) Model; (ii) Regression Model in Which Means are Outcomes; (iii) Random Coefficients Model; (iii) Constant and Slope Coefficients as Outcomes. As a result of the analysis conducted to examine the level of relationship of the features regarding mathematics achievement of students at student and school level and the state of these relations between TIMSS 2007-2011 applications, it was found that in both TIMSS periods, eighth grade students’ mathematics achievements vary significantly among schools. According to the results of both 2007 and 2011 TIMSS, at school level, student’s mathematics achievement has a positive and significant relationship with teacher’s emphasis on the academic achievement variable. No significant relationship between students’ mathematics achievement and teachers’ working conditions and teachers’ collaboration for improving teaching variables were found in the 2007 and 2011 assessments. Students’ performances in TIMSS 2007 and 2011 mathematics exams have a significant relationship with students not being subjected to bullying at school and students’ like learning mathematics variables on student level. Students’ confidence in mathematics variable has a significant effect in achievements in 2011, which is not the case in 2007 and students valuing mathematics variable does not have a significant relationship with students’ mathematics achievement in either year.Bu çalışmada, Türkiye’deki sekizinci sınıf öğrencilerinin matematik başarılarını etkileyen öğrenci özellikleri (okuldaki akran zorbalığına ilişkin algı, matematikte kendine güven, matematiği öğrenmekten hoşlanma ve matematiğe değer verme) ile okul düzeyinde ele alınan öğretmen özellikleri (öğretmenin çalışma koşulları, öğretmenin akademik başarı üzerindeki vurgusu ve öğretimi geliştirmek için meslektaşlarıyla gösterdiği iş birliği) arasındaki ilişkiler araştırılmıştır. İlişkisel tarama modelinde olan araştırmanın örneklemini Uluslararası Matematik ve Fen Eğilimleri Araştırması (Trends in International Mathematics and Science Study-TIMSS) 2007 uygulamasına katılan 141 öğretmen, 4498 öğrenci ve 2011 uygulamasına katılan 219 öğretmen, 6928 öğrenci oluşturmaktadır. Araştırmanın veri toplama araçlarını, TIMSS 2007 ve 2011 uygulamasında kullanılan öğrenci ve öğretmen anketleri ile matematik başarı testleri oluşturmaktadır. Bu ölçme araçlarından elde edilen verilerin çözümlenmesinde, hiyerarşik lineer modelleme (HLM) yöntemi kullanılmıştır. Analizlerde dört hiyerarşik model kullanılmıştır. Bu modeller sırasıyla: (i) Tesadüfi Etkili Tek Yönlü Varyans Analizi Modeli; (ii) Sonuçların Ortalamalar Olduğu Regresyon Modeli; (iii) Tesadüfi Katsayı Regresyon Modeli; (iv) Sabit ve Eğim Katsayılarının Çıktı Olduğu Modeldir. Öğrenci ve okul düzeyinde öğrencilerin matematik başarıları ile ilişkili özelliklerin ilişki derecesini ve 2007-2011 yılı TIMSS uygulamaları arasındaki bu ilişkilerin durumunu incelemek amacıyla yapılan analizler sonucunda, her iki TIMSS uygulama döneminde de sekizinci sınıf öğrencilerinin matematik başarısında okullar arasında oldukça farklılık olduğu görülmüştür. Hem 2007 hem 2011 TIMSS uygulaması sonuçlarına göre okul düzeyinde, öğrencinin matematik başarısının öğretmenin akademik başarı vurgusu değişkeniyle ilişkisi pozitif yönde ve manidardır. 2007 ve 2011 yıllarındaki uygulamalarda, öğretmenin çalışma koşulları ve öğretmenin öğretimi geliştirmek için meslektaşlarıyla iş birliği yapma değişkenleri ile öğrencinin matematik başarısı arasında manidar ilişki bulunmamıştır. Okulda zorbalığa az maruz kalan ve matematikten hoşlanan öğrencilerin matematik testindeki performansları, TIMSS 2007 ve 2011’de daha yüksektir. Öğrencilerin matematikte kendilerine güvenmeleri 2011 yılı TIMSS başarılarında manidar etkiye sahipken 2007 yılında değildir. Ayrıca öğrencilerin matematiğe verdiği değer, her iki uygulama döneminde de öğrencilerin matematik başarısıyla manidar ilişki göstermemiştir

A novel approach for rapid screening of mitochondrial D310 polymorphism

BACKGROUND: Mutations in the mitochondrial DNA (mtDNA) have been reported in a wide variety of human neoplasms. A polynucleotide tract extending from 303 to 315 nucleotide positions (D310) within the non-coding region of mtDNA has been identified as a mutational hotspot of primary tumors. This region consists of two polycytosine stretches interrupted by a thymidine nucleotide. The number of cytosines at the first and second stretches are 7 and 5 respectively, according to the GeneBank sequence. The first stretch exhibits a polymorphic length variation (6-C to 9-C) among individuals and has been investigated in many cancer types. Large-scale studies are needed to clarify the relationship between cytosine number and cancer development/progression. However, time and money consuming methods such as radioactivity-based gel electrophoresis and sequencing, are not appropriate for the determination of this polymorphism for large case-control studies. In this study, we conducted a rapid RFLP analysis using a restriction enzyme, BsaXI, for the single step simple determination of 7-C carriers at the first stretch in D310 region. METHODS: 25 colorectal cancer patients, 25 breast cancer patients and 41 healthy individuals were enrolled into the study. PCR amplification followed by restriction enzyme digestion of D310 region was performed for RFLP analysis. Digestion products were analysed by agarose gel electrophoresis. Sequencing was also applied to samples in order to confirm the RFLP data. RESULTS: Samples containing 7-C at first stretch of D310 region were successfully determined by the BsaXI RFLP method. Heteroplasmy and homoplasmy for 7-C content was also determined as evidenced by direct sequencing. Forty-one percent of the studied samples were found to be BsaXI positive. Furthermore, BsaXI status of colorectal cancer samples were significantly different from that of healthy individuals. CONCLUSION: In conclusion, BsaXI RFLP analysis is a simple and rapid approach for the single step determination of D310 polymorphism of mitochondrial DNA. This method allows the evaluation of a significant proportion of samples without the need for sequencing- and/or radioactivity-based techniques

Laparoscopic resection of a residual retroperitoneal tumor mass of nonseminomatous testicular germ cell tumors

Resection of a residual retroperitoneal tumor mass (RRRTM) is standard procedure after combination chemotherapy for metastatic nonseminomatous testicular germ cell tumors (NSTGCT). At the University Medical Center Groningen, 79 consecutive patients with disseminated NSTGCT were treated with cisplatin combination chemotherapy between 2005 and 2007. Laparoscopic RRRTM was performed for patients with RRTM located less than 5 cm ventrally or laterally from the aorta or the vena cava. The 29 patients who fulfilled the criteria had a median age of 25 years (range, 16-59 years). The stages of disease before chemotherapy treatment according to the Royal Marsden classification were 2A (n = 6, 21%), 2B (n = 14, 48%), 2C (n = 3, 10%), and 4 with a lymph node status of N2 (n = 6, 21%). The median duration of laparoscopy was 198 min (range, 122-325 min). The median diameter of the RRTM was 21 mm (range, 11-47 mm). Laparoscopic resection was successful for 25 patients (86%). Conversion was necessary for three patients (10%): two due to bleeding and one because of obesity. One nonplanned hand-assisted procedure (3%) also had to be performed. Histologic examination of the specimens showed fibrosis or necrosis in 12 patients (41%), mature teratoma in 16 patients (55%), and viable tumor in 1 patient (3%). The median hospital stay was 1 day (range, 1-6 days). During a median follow-up period of 47 months (29-70 months), one patient experienced an early relapse (1 month after the end of treatment) (4%). For properly selected patients, laparoscopic resection of RRTM is an improvement in the combined treatment of disseminated NSTGCT and associated with a short hospital stay, minimal morbidity, rapid recovery, and a neat cosmetic result. Long-term data to prove oncologic efficacy are awaited

Peri-operative red blood cell transfusion in neonates and infants: NEonate and Children audiT of Anaesthesia pRactice IN Europe: A prospective European multicentre observational study

BACKGROUND: Little is known about current clinical practice concerning peri-operative red blood cell transfusion in neonates and small infants. Guidelines suggest transfusions based on haemoglobin thresholds ranging from 8.5 to 12 g dl-1, distinguishing between children from birth to day 7 (week 1), from day 8 to day 14 (week 2) or from day 15 (≥week 3) onwards. OBJECTIVE: To observe peri-operative red blood cell transfusion practice according to guidelines in relation to patient outcome. DESIGN: A multicentre observational study. SETTING: The NEonate-Children sTudy of Anaesthesia pRactice IN Europe (NECTARINE) trial recruited patients up to 60 weeks' postmenstrual age undergoing anaesthesia for surgical or diagnostic procedures from 165 centres in 31 European countries between March 2016 and January 2017. PATIENTS: The data included 5609 patients undergoing 6542 procedures. Inclusion criteria was a peri-operative red blood cell transfusion. MAIN OUTCOME MEASURES: The primary endpoint was the haemoglobin level triggering a transfusion for neonates in week 1, week 2 and week 3. Secondary endpoints were transfusion volumes, 'delta haemoglobin' (preprocedure - transfusion-triggering) and 30-day and 90-day morbidity and mortality. RESULTS: Peri-operative red blood cell transfusions were recorded during 447 procedures (6.9%). The median haemoglobin levels triggering a transfusion were 9.6 [IQR 8.7 to 10.9] g dl-1 for neonates in week 1, 9.6 [7.7 to 10.4] g dl-1 in week 2 and 8.0 [7.3 to 9.0] g dl-1 in week 3. The median transfusion volume was 17.1 [11.1 to 26.4] ml kg-1 with a median delta haemoglobin of 1.8 [0.0 to 3.6] g dl-1. Thirty-day morbidity was 47.8% with an overall mortality of 11.3%. CONCLUSIONS: Results indicate lower transfusion-triggering haemoglobin thresholds in clinical practice than suggested by current guidelines. The high morbidity and mortality of this NECTARINE sub-cohort calls for investigative action and evidence-based guidelines addressing peri-operative red blood cell transfusions strategies. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT02350348

Change in beliefs after first-year of teaching: The case of Turkish national curriculum context

The impact of national curriculum context on mathematics related beliefs of 12 beginning middle grades mathematics teachers was investigated after the teacher education program and first-year teaching through interviews and a combination of three belief frameworks. National curriculum requirements, lack of effective mentoring programs, and preservice tutoring experiences were detected as the major factors impacting beliefs. Participants simultaneously had teacher-centered and student-centered beliefs, causing inconsistency in beliefs and practices. While participants' preservice and first-year experiences contrasted, they developed contextual beliefs to deal with the difficulties. Reflections on teacher education and beginning teacher support policies in national curriculum contexts were discussed

Semiregular Modules With Respect To A Fully Invariant Submodule

Let M be a left R-module and F a submodule of M for any ring R. We call M F-semiregular if for every x is an element of M, there exists a decomposition M = A circle plus B such that A is projective, A less than or equal to Rx and Rx boolean AND B less than or equal to F. This definition extends several notions in the literature. We investigate some equivalent conditions to F-semiregular modules and consider some certain fully invariant submodules such as Z(M), Soc(M), delta(M). We prove, among others, that if M is a finitely generated projective module, then M is quasi-injective if and only if M is Z(M)-semiregular and M circle plus M is CS. If M is projective Soc(M)-semiregular module, then M is semiregular. We also characterize QF-rings R with J(R)(2) = 0.Wo

Monitoring of heavy metal pollution by using populus nigra and cedrus libani

As metals and metal compounds have impact on human health, it is important to identify biomonitor plants that can be used to monitor their levels in environmental and biological samples. In this study, two different plants (Populus nigra and Cedrus libani) were used as bioindicators. This was evaluated by monitoring heavy metal pollution in Kırşehir province with these plant samples collected from the vicinity of casting factory (Casting factory station) and the region where there is no casting factory (Boztepe station). Nickel (Ni), lead (Pb), and copper (Cu) levels were determined in the needle, leaves of plants, and soil samples where they grow using High Resolution-Continuum Source Flame Atomic Absorption Spectrometry (HR-CS FAAS). The levels of Ni, Pb, and Cu in Populus nigra were determined to be in the range of 0.87 to 2.59 μg/g, 0.40 to 0.75 μg/g, and 2.27 to 9.66 μg/g, respectively. In analysis of Cedrus libani, metal levels were found the range of 0.44 to 1.12 µg/g for Ni, 0.84 to 3.18 µg/g for Pb and 2.16 to 4.60 µg/g for Cu. The levels of Ni in Populus nigra samples collected from the Casting factory station (CFS) (2.49±0.09 µg/g) increased compared to the samples collected from the Boztepe station (1.16±0.24 µg/g) (p<0.05). Pb levels in Populus nigra were determined as 0.50±0.11 µg/g and 0.67±0.10 µg/g for samples collected from the CFS and Boztepe stations, respectively. Cu levels in Populus nigra were determined as 6.73±0.99 µg/g and 5.53±3.39 µg/g for the samples collected from the CFS and Boztepe stations, respectively. The levels of Pb and Cu in Populus nigra were not significant for both the stations (p>0.05). The levels of Ni in Cedrus libani samples collected from the Boztepe station (1.03±0.18 µg/g) were higher than that in the samples collected from the CFS (0.66±0.24 µg/g) (p<0.05). The levels of Pb in Cedrus libani were determined as 1.74±0.26 µg/g and 1.00±0.16 µg/g for the samples collected from the CFS and Boztepe stations, respectively (p<0.05). The levels of Cu in Cedrus libani were determined as 4.27±0.26 µg/g and 2.87±0.75 µg/g for the samples collected from the CFS and Boztepe stations, respectively (p<0.05). As a result, we suggest that Cedrus libani could be used as biomonitor plants for Pb and Cu and Populus nigra for Ni