Preservice Mathematics Teachers’ Personal Figural Concepts and Classifications About Quadrilaterals

The aim of this study was to determine preservice mathematics teachers’ personal figural concepts and hierarchical classifications about quadrilaterals and to investigate the relationships between them. The participants were 57 preservice primary mathematics teachers in their senior year at a state university in Turkey. The preservice mathematics teachers were administered a questionnaire that consisted of 13 questions extracted from studies on the descriptions and images of quadrilaterals, identification of quadrilateral families among given images, and identification and classification of the relationships between quadrilaterals. The results showed that the preservice mathematics teachers’ knowledge of quadrilaterals learnt at primary-secondary school level and prototypical images were dominant in their personal figural concepts. Also, the teachers didn’t use the hierarchical definitions of quadrilaterals and were not able to establish relationships among quadrilaterals due to the effect of prototypical images in choosing a family category among the given images. On the other hand, the majority of the participants gave correct answers to the questions about the dual relationships among quadrilaterals. The study concluded that although the preservice teachers possessed formal definitions of quadrilaterals, their prototypical images affected their personal figural concepts

Neki biološki parametri trlje kamenjarke (Mullus surmuletus L.) iz Erdemitskog zaljeva, (Sjeverno Egejsko more, Turska)

Growth, sex ratio, and reproduction of striped red mullet (Mullus surmuletus L.) were determined from 520 specimens collected in the northwestern Aegean coast of Turkey from September 2009 to July 2010. Total length ranged from 7.7 to 17.0 cm while weight varied between 3.50 and 58.9 g. According to the length-weight relationship, positive allometry was confirmed for both sexes. The sex ratio was skewed in favour of males (1:1.73). The monthly values of gonadosomatic index (GSI) of females indicated that spawning occurred mainly between April and September with a peak in July. Values of Condition factor (CF) and Hepatosomatic index (HSI) varied between 0.71-1.57 and 0.10-1.43, respectively.Starost, rast i smrtnost trlje kamenjarke, (Mullus surmuletus L.) procijenjene su kod 520 jedinki prikupljenih na sjeverozapadnoj obali Egejskog mora, Erdemitski zaljev u Turskoj od rujna 2009. do srpnja 2010. Ukupna duljina jedinki je u rasponu od 7,7 do 17,0 cm, a masa je kolebala između 3,50 i 58,9 g. Prema dužinsko-težinskom odnosu, ustanovljena je pozitivna alometrija za oba spola. Omjer zastupljenosti spolova bio je u korist mužjaka (1: 1,73). Mjesečne vrijednosti gonadosomatskog indeksa (GSI) za ženke pokazuju da se mrijest obavlja posebice u razdoblju travanj - rujan, sa vrhuncem u srpnju. Vrijednosti kondicijskog faktora (CF) i hepatosomatskog indeksa (HSI) kolebali su između 0.71-1.57 i 0.10-1.43, respektivno

Age, growth and reproductive properties of an invasive species Carassius gibelio (Bloch, 1782) (Cyprinidae) in the Ikizcetepeler Dam Lake (Balikesir), Turkey

Background and Purpose: The Prussian carp Carassius gibelio is well known as a hazardous fish species for native fish communities. Ikizcetepeler Dam Lake inhabits some fish species as Cyprinus carpio, Leuciscus cephalus, and Barbus species. The dam lake has major economic importance to the area for both fisheries and drinking water. The reason to select C. gibelio was due to the dominant species in stagnant and slow running waters and possible harmful interactions with native species. Materials and methods: A total of 480 specimens of C. gibelio were monthly collected by gill nets during a 1-year period from Ikizcetepeler Dam Lake. Age was determined from scales. Length-weight relationships, von Bertalanffy equation were used to estimated for growth. Sex were determined by macroscopic observation of gonads. Spawning period of this species was determined according to gonado-somatic index (%). Results: Females and males reached a maximum age groups of VI. Total length was 23.6–31.3 cm in females and 23.0–31.4 cm in males. The male and female ratio was 1:3.52 (M:F) in the favor of females. The Von Bertalanffy growth equations (in length) were found as Lt= 34.89.(1-e–0.11(t+7.66)), Lt= 32.09 (1-e–0.23(t+5.83)) for females and males, respectively. The estimated b values were given as 2.886 and 2.981 for females and males, respectively (b<3). The condition of the fish increased during early summer. Spawning period of this species occured between April and July. Conclusions: With a comparison of the relevant literature, the studied Prussian carp population was characterized by a shorter life span and more rapid growth during the first years of life. These can be considered as typical features of invasive species

Eruptive Vellus Hair Cysts: A Case and Review of Literature

WOS: 000366969900012

Induction of lutein production in Scenedesmus obliquus under different culture conditions prior to its semipreparative isolation

Microalgae with their improved growth rates and accumulation of high-value-added products make their commercial production attractive. Among them, lutein, which is a carotenoid, plays a very important role due to its various applications in the food and pharmaceutical industry. Induction of its biosynthesis can be triggered by various stress conditions like light. In this study, three different light intensities (50,150 and 300 mu mol photons/m(2)s) and aeration rates (1, 3, and 5 L/min) were utilized to induce the lutein biosynthesis and biomass productivity in Scenedesmus obliquus. Lutein was isolated by preparative chromatography using a semiprep C-30 column (10 x 250 mm, 5 mu m) and its confirmation was made by LC-MS/MS. According to the results, Scenedesmus obliquus synthesized the maximum lutein (8.01 +/- 0.1 mg/g) with biomass productivity of 1.698 g/L at 150 mu mol photons/m(2)s light intensity using 3 L/min as aeration rate. To the best of the authors' knowledge, this was the first study that the lutein was isolated by preparative chromatography using semiprep C-30 carotenoid column with a simple and rapid separation, which can be used as a reference methodology for the isolation of other carotenoids. Scenedesmus obliquus can be an important alternative source for commercial production of lutein, as it is indicated from the results of this study.Scientific and Technological Research Council of Turkey (TUBITAK) through the COST Project [216Z167]This research was funded by the Scientific and Technological Research Council of Turkey (TUBITAK) through the COST Project 216Z167

Morphologic structuring between populations of chub mackerel Scomber japonicus in the Black, Marmara, Aegean, and northeastern Mediterranean Seas

Morphometric and meristic analyses of chub mackerel Scomber japonicus were used to discriminate stocks throughout the Black, Marmara, Aegean, and northeastern Mediterranean Seas. Morphometric and meristic analyses showed a similar pattern of differentiation between S. japonicus stocks and revealed a clear discreteness of two groups, northeastern Mediterranean (Antalya Bay-Iskenderun Bay) and the northern group, including the Aegean, Marmara, and Black Seas. Univariate analysis of variance showed significant differences between means of the samples for most morphometric and meristic descriptors. The contribution of each variable in distinguishing between the stocks for the first discriminant function revealed high contribution from head size measurements for morphometrics, and first and second dorsal fin rays for meristics. Plotting all specimens on the first two discriminant functions accounted for 76% of total variance for morphometric and 69% of total variance for meristic analyses, and both plots resulted in two main groupings. The overall random assignment of individuals to their original group was higher in morphometric than in meristic analysis

Purification of fucoxanthin from the diatom Amphora capitellata by preparative chromatography after its enhanced productivity via oxidative stress

Microalgae with high growth rates represent a potential source of carotenoids including fucoxanthin. For commercial fucoxanthin production, choosing the cultivation system is a critical parameter where the final biomass must contain a high content of the target product. To realize this, the reaction system must allow the use of stress conditions that induce the synthesis of these compounds. In this study, oxidative stress was applied to the diatom Amphora capitellata by the formation of reactive oxygen species in the culture medium through chemical reactions which generate. The effect of this oxidative stress on the amount of fucoxanthin and specific growth rate of A. capitellata was investigated. In the presence of H2O2/NaOCl, fucoxanthin content was 41.83 +/- 0.92 mg g(-1) as determined by HPLC-DAD a 2.20-fold increase compared with the control group. For the purification of fucoxanthin, preparative HPLC using a semi-prep C-30 carotenoid column (10 x 250 mm, 5 mu m) was used for the first time with an isocratic elution of 75:25 (methanol:acetonitrile) mobile phase at a flow rate of 4 mL min(-1). Liquid chromatography tandem mass spectrometry (LC-MS/MS) was employed for the confirmation of fucoxanthin. The developed method has potential to obtain highly pure fucoxanthin for food and pharmaceutical applications using A. capitellata as a commercial source of fucoxanthin, particularly after its enhancement via oxidative stress.This research was funded by the Scientific and Technological Research Council of Turkey (TUBITAK) through the COST Project 216Z167.Scientific and Technological Research Council of Turkey (TUBITAK) through the COST [216Z167

A rare variant of pilomatricoma: pseudobullous pilomatricoma

WOS: 000420880900004PubMed ID: 26399843Pilomatricoma (PM; calcifying epithelioma of Malherbe) is a benign tumor originating from the matrix of the hair follicles. Clinical types of the tumor are familial, perforating, multinodular, exophytic, anetodermic, and giant PM. The bullous type is seen only in 3 to 6% of cases. Because the bullous areas detected in PM are filled with lymphatic liquid, some authors use the term pseudobulla. This report presents a 26-year-old female patient that was diagnosed with pseudobullous PM based on clinical, radiologic, and histopathological findings, and the pathogenesis of the bullous appearance of PM is reviewed from the literature

Carotenoid Profile in Prochlorococcus sp and Enrichment of Lutein Using Different Nitrogen Sources

WOS: 000390090300009Various carotenoids of the cyanobacterium Prochlorococcus sp. are identified using chromatographic/spectroscopic techniques and quantified using HPLC-DAD. In the present study, beta-apo-8'-carotenal was used as internal standard. Identification of carotenoids was carried out by comparing the retention time, absorption spectra, and mass spectra of unknown peaks with reference standards. All-trans-lutein was found to be the major carotenoid in this cyanobacterium, and, therefore, algal productivity and the potential for lutein accumulation were analyzed as a function of different nitrogen sources such as nitrate, nitrite, ammonia, and urea for cultivation. Among them, urea clearly led to the best lutein accumulation. According to the experimental evidence, lutein increased from 2.54 to 3.34 mg g(-1) in the cyanobacteria when urea was used as the nitrogen source.Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TBAG 110T099]The authors would like to acknowledge the Scientific and Technological Research Council of Turkey for the support of this work through the project TBAG 110T099 and also the Center of Material's Research at Izmir Institute of Technology for the facilities (SEM and Elemental Analyzer)