Okuma Güçlüklerinde Çift Yetersizlik Hipotezi: Hipoteze Göre Oluşturulmuş Grupların Okuma ve Okuduğunu Anlama Performanslarının Boylamsal İncelemesi

In this study, we aimed to determine the validity of the double-deficit hypothesis, which argues that reading difficulties arise due to inadequacies in phonological awareness and rapid naming, in relation to reading difficulties in a transparent language such as Turkish. Accordingly, children attending a kindergarten were assigned to four groups: a double-deficit group (n = 23), phonological awareness deficit group (n = 35), rapid naming deficit group (n = 29) or control group (n = 48) according to the scores they received on measures of phonological awareness and rapid naming. The performance of the groups in reading and reading comprehension was followed longitudinally from the first grade to the end of the second grade and were compared at four time points. On the basis of multivariate analysis of variance (MANOVA), it was determined that the double-deficit group performed worst in reading and reading comprehension tasks, and the control group performed best. While the reading and reading comprehension achievements of all groups increased over time, the findings suggest that the performance of groups with phonological awareness and rapid naming deficits differed significantly from the double-deficit group and the control group. This study, which examined the effects of the double-deficit hypothesis for Turkish-speaking children, offers a new approach to identifying children at risk of reading difficulties in early years and to planning appropriate interventions.Bu çalışmada okuma güçlüklerinin sesbilgisel farkındalık ile hızlı isimlendirmede yaşanan yetersizliklere bağlı olarak ortaya çıktığını savunan Çift Yetersizlik Hipotezinin Türkçe gibi şeffaf bir dilde okuma güçlükleri ile ilişkili geçerliğinin belirlenmesi amaçlanmıştır. Buna göre, anasınıfına devam eden çocuklar, sesbilgisel farkındalık ve hızlı isimlendirme becerileri ölçümlerinden aldıkları puanlara göre çift yetersizlik grubu (n=23), sesbilgisel farkındalıkta yetersizlik yaşayan grup (n=35), hızlı isimlendirmede yetersizlik yaşayan grup (n=29) ve herhangi bir yetersizliği olmayan kontrol grubu (n=48) olmak üzere dört gruba atanmışlardır. Grupların okuma ve okuduğunu anlama becerilerindeki performansları birinci sınıftan ikinci sınıfın sonuna kadar boylamsal olarak izlenmiş ve dört ayrı zamanda karşılaştırılmıştır. Çok Değişkenli Varyans Analizi (MANOVA) ile yapılan analizler sonucunda genel olarak çift yetersizlik grubunun okuma ve okuduğunu anlama görevlerinde en düşük başarıyı, kontrol grubunun da en yüksek başarıyı sergilediği belirlenmiştir. Bütün grupların okuma ve okuduğunu anlama başarıları gelişime paralel bir şekilde artış göstermekle birlikte, sesbilgisel farkındalıkta ve hızlı isimlendirmede yetersizlik yaşayan grupların dönemlere göre performanslarının çift yetersizlik grubu ile kontrol grubundan anlamlı olarak farklılaştığına ilişkin bulgular alanyazını desteklemektedir. Çift yetersizlik hipotezinin Türkçe konuşan çocuklardaki etkilerinin incelendiği bu çalışma, okuma güçlüğü açısından risk grubunda yer alan çocukların erken dönemde belirlenebilmesi ve uygun müdahalelerin planlaması için uygulamaya yeni bir bakış açısı sunmaktadır

Fonolojik İşlemleme ve Dil Becerilerinin Okuma Akıcılığının Boylamsal Gelişimindeki Rolü

The acquisition and development of reading fluency, consisting of three components: accuracy, automaticity, and prosody, require the utilization of various language and cognitive skills due to their complex and multifaceted nature. Phonological processing skills are frequently emphasized in the literature, with a clear connection established between phonological processing and fluent reading. Additionally, existing literature indicates that predictors of reading in alphabetic languages are largely universal, but their contributions vary based on the transparency of orthography. In this context, it is important to determine the impact of phonological processing and language-based components on the development of reading fluency, especially in transparent orthographies such as Turkish. This research aims to determine the role of phonological processing and receptive and expressive language mesured in the beginning of first grade in the longitudinal development of text reading fluency over three semesters in first and second grades. The study, conducted in a correlational design, involved 310 participants selected randomly from 45 schools representing lower, middle and upper socioeconomic levels in Ankara. The Passage Reading Test of the Literacy Assessment Battery was used to assess participants' reading fluency, while the Phonological Awareness subtests of the Test of Early Literacy, Object and Color Naming subtests of the Rapid Naming Test, and the verbal memory subscales of the Working Memory Scale were employed to evaluate the phonological processing skills. A measurement model analysis was conducted within the Structural Equation Models, followed by the addition of predictive variables to the longitudinal development model to identify their roles in the developmental process. Results indicated that participants' reading fluency performances increased in each semester throughout the study, and the phonological processing and expressive language skills in the beginning of first grade significantly contributed to participants' reading fluency development in first and second grade. These findings suggest that deficiencies in phonological processing and language development observed in the early stages can be considered significant indicators of reading difficulties.Doğruluk, otomatiklik ve prozodi olmak üzere üç bileşenden oluşan akıcı okuma becerilerinin edinimi ve gelişimi karmaşık ve çok bileşenli doğası nedeniyle dile ve bilişe dayalı birçok becerinin kullanılmasını gerektirmektedir. Fonolojik işlemleme becerileri de alanyazında bu beceriler arasında sıkça vurgulanmakta, akıcı okuma ile ilişkisi açık bir şekilde gösterilmektedir. Ayrıca alanyazında alfabetik dillerde okumanın yordayıcılarının büyük bir kısmının evrensel olduğu, ancak her bir yordayıcının katkısının ortografinin şeffaflığına göre farklılaştığı ortaya konulmuştur. Bu bağlamda, özellikle Türkçe gibi şeffaf yazı sistemlerinde akıcı okumanın gelişiminde fonolojik işlemlemeye ve dile dayalı bileşenlerden hangilerinin etkisi olduğunun belirlenmesinde yarar vardır. Bu araştırmada; birinci sınıf birinci dönemdeki fonolojik işlemleme ile alıcı ve ifade edici dil becerilerinin, birinci ve ikinci sınıfta üç dönem boyunca izlenen metin okumadaki akıcılığın boylamsal gelişimindeki rolünün belirlenmesi amaçlanmıştır. Korelasyonel desende gerçekleştirilen araştırma Ankara ilinde alt-orta ve üst sosyoekonomik düzeyi temsil eden her tabakadan seçkisiz olarak belirlenen 45 okulda öğrenim gören 310 katılımcı ile gerçekleştirilmiştir. Katılımcıların metin okuma akıcılıklarının belirlenmesinde Okuma Yazma Değerlendirme Bataryası’nın (OYAB) Metin Okuma Testi, fonolojik işlemleme becerilerinin değerlendirilmesinde ise EROT’un Sesbilgisel Farkındalık alt testleri, Hızlı İsimlendirme Testinin Nesne ve Renk İsimlendirme alt testleri ve Çalışma Belleği Ölçeğinin sözel bellek alanındaki alt ölçekleri kullanılmıştır. Yapısal Eşitlik Modelleri kapsamında ölçme modeli analizi yapılmış, ardından boylamsal gelişim modeline yordayıcı değişkenler eklenerek gelişim sürecindeki rolleri tespit edilmiştir. Sonuçlar, katılımcıların akıcı okuma performanslarının çalışmanın yürütüldüğü üç dönem boyunca her dönemde artış gösterdiğini, birinci sınıf birinci dönemdeki fonolojik işlemleme ve ifade edici dil puanlarının katılımcıların akıcı okuma gelişimlerine katkısının anlamlı olduğunu göstermiştir. Bu sonuçlar, erken dönemde gözlenebilen fonolojik işlemleme ve dil gelişimindeki yetersizliklerin okuma güçlüklerine ilişkin önemli bir gösterge olarak ele alınabileceği şeklinde değerlendirilmektedir

An Adapted Dialogic Reading Program for Turkish Kindergarteners from Low Socio-economic Backgrounds

The study aimed to examine the effectiveness of the Adapted Dialogic Reading Program (ADR) on the language and early literacy skills of Turkish kindergarteners from low socio-economic (SES) backgrounds. The effectiveness of ADR was investigated across six different treatment conditions including classroom and home based implementations in various combinations in six different schools. The study group consisted of 112 kindergarteners, their teachers (n=6) and their parents (n=56). The treatment lasted for seven weeks. In this quasi-experimental study, children were pre- and post-tested on measures of language and early literacy. Data were analyzed using ANCOVA, a mixed design ANOVA, and a single factor ANOVA. Results revealed that ADR was effective in promoting the language and early literacy skills of kindergarteners in treatment conditions including home based intervention. Intensity of treatment was also found to play a major role in child performance in that, ADR implemented in only one setting (either at home or in the classroom) promoted higher achievement in language while ADR implemented in both settings promoted higher achievement in early literacy. The findings are discussed within the context of early childhood education programs in Turkey

Monodispers hidrofobik manyetik nanoparçacıkların ters mikroemülsiyon metodu ile silika kaplanması.

Magnetic nanoparticles find broad applications in biomedical field such as drug delivery, hyperthermia and magnetic resonance imaging (MRI). For these applications magnetic nanoparticles need to be coated with suitable materials which are soluble, biocompatible and nontoxic. Among these materials, silica is the most often used coating material. This thesis is focused on preparation of silica coated iron oxide magnetic nanoparticles. Magnetic iron oxide nanoparticles are synthesized by thermal decomposition method. In the presence of iron acetylacetonate Fe(acac)3, a high boiling point organic solvent and a reducing agent, particle sizes ranging from about 5 nm to 7 nm were obtained. Nanoparticles were characterized by transmission electron microscopy (TEM). The obtained nanoparticles were coated with ultra thin silica shell via reverse microemulsion method. The influence of the amount of Igepal CO-520, NH4OH and TEOS was studied systematically and their amounts were optimized to yield monodisperse and well defined particles. The size of the silica coated magnetic nanoparticles and their agglomerates were determined by TEM images and particle size analyzer (zeta sizer). X-Ray photoelectron spectroscopy (XPS) was used to confirm the presence of silica whenever the coating could not be seen by TEM measurements. Magnetic nanoparticles having 4-6 nm thickness of silica shell were obtained. The results showed that the amount of surfactant Igepal CO-520 played an important role in the reaction system.M.S. - Master of Scienc

Polyphosphosphoesters for the design of organic and inorganic drug delivery systems

Polymers with repeating phosphoester linkages in the backbone are biodegradable and emerged as a promising class of novel biomaterials, especially in the field of drug delivery systems. The pentavalency of the phosphorus atom offers a large diversity of structures and as a consequence a wide range of properties for these materials. The thesis focused on the synthesis of novel well-defined diblock copolymers made of one hydrophilic polyethylene oxide (PEO) block and one polyphosphotriester (PPE) block bearing unsaturations as side-group, as a platform for the design of advanced drug delivery systems. Firstly, novel alkenyl PEO-b-PPE amphiphilic copolymers were self-assembled in water, taking profit of the unsaturations to prepare core cross-linked micelles. Doxorubicin could be successfully loaded by impregnation in these micellar nanocarriers leading to improved stability and loading as compared to the corresponding non-cross-linked systems. Besides, the alkynyl and allyl unsaturations of PEO-b-PPE copolymers were used to prepare novel double hydrophilic block copolymers exhibiting calcium complexation capabilities. They were found quite efficient as template for the formation of calcium carbonate particles providing particles of unprecedented small size, and high size homogeneity. The use of a supercritical carbon dioxide process with carboxylic acid containing copolymers allows reaching CaCO3 particles about 1.5 µm. Finally, we demonstrate that adding lysozyme to the process allows encapsulation of this enzyme into the CaCO3 carriers, the protein activity being better preserved by using the PPE-b-PEO as compared to more conventional hyaluronic acid as a template

Polyphosphoesters: new trends in synthesis and drug delivery applications

peer reviewedPolymers with repeating phosphoester linkages in the backbone are biodegradable materials that emerge as a promising class of novel biomaterials, especially in the field of drug delivery systems. In contrast to aliphatic polyesters, the pentavalency of the phosphorus atom offers a large diversity of structures and as a consequence a wide range of properties for these mate- rials. In this paper, it is focused on the synthesis of well-defined polyphosphoesters (PPEs) by organocatalyzed ring-opening polymerization, improving the functionalities by combination with click reactions, degrada- tion of functional PPEs and their cytotoxicity, and inputs for applications in drug delivery

Synthesis of degradable polyphosphoester copolymers for templating calcium carbonate drug delivery carriers

Degradable acid bearing polyphosphoester (PPE) copolymers were prepared by combination of organocatalyzed ring opening polymerization and click chemistry. Their solution behavior and ability to complex calcium ions were studied as well as their capacity to template CaCO3 particles dedicated to drug delivery