322 research outputs found
Cross - cultural adaptation and preliminary validation of the Turkish version of the Early Childhood Oral Health Impact Scale among 5-6-year-old children
<p>Abstract</p> <p>Background</p> <p>In Turkey, formal pre-primary education for children 5- 6 years old provides the ideal setting for school-based oral health promotion programs and oral health care services. To develop effective oral health promotion programs, there is a need to assess this target group's subjective oral health needs as well as clinical needs. The Early Childhood Oral Health Impact Scale (ECOHIS) is a well-known instrument for assessing oral health quality of life in children aged 0-5 years old and their families. This study aimed to adapt the ECOHIS for children 5-6 years old in a Turkish-speaking community and to undertake a preliminary investigation of its psychometric properties.</p> <p>Methods</p> <p>The Turkish version of the ECOHIS was obtained with forward/backward translations, expert panels and pre-testing and it was tested in a convenience sample of 121 parents of 5- 6 year-old children attending nursery classes of three public schools. Data were collected through clinical examinations and self-completed questionnaires. The main analyses were carried out on the imputed data set. The validity of content, face, construct, discriminant and convergent and as well as the reliability of internal and test-retest of the ECOHIS were evaluated. Sensitivity analysis was performed to examine the effect of the complete case analysis for managing "Don't know" responses on the validity and reliability of the ECOHIS.</p> <p>Results</p> <p>The analysis of the imputed data set showed that Cronbach's alphas for the child and family sections were 0.92 and 0.84 respectively, and for the whole scale was 0.93. The intraclass correlation coefficient for test-retest was 0.86. The scale scores on the child and parent sections indicating worse quality of life were significantly associated with poor parental ratings of their child's oral health, high caries experience, higher gingival index scores and problem-orientated dental attendance, supporting its construct, convergent and discriminant validity. Sensitivity analysis showed that the mean imputation method and the complete case analysis did not have differing effects on the validity and reliability of the ECOHIS.</p> <p>Conclusions</p> <p>This study provided preliminary evidence concerning validity and reliability of the Turkish version of the scale among 5-6-year-old children. Future studies should be conducted on the ECOHIS to evaluate fully its psychometric properties in both community- based and clinically-based studies among parents of children younger than five. This study provides initial evidence that the ECOHIS aimed at children aged 0-5 years may be a useful tool for assessing the oral health quality of life in 6 year - old preschool children.</p
The emergence and consolidation of the AKP and its impact on Turkish politics and society
This thesis concerns the current ruling party, the AKP (Adalet ve Kalkınma
Partisi - Justice and Development Party) in Turkey. Its aim is to examine the
emergence and consolidation of the AKP, as well as to determine whether or not
this has shaped the evolution of the party system in Turkey. This research draws
on a qualitative research approach, through interviews with 36 key informants
from political parties, NGOs, grassroots organizations and through gathering
data in the literature produced by parties and other statutory and voluntary
agencies, as well as through the collection of descriptive statististics related to
socio-economic structures, migration, occupational categories, macroeconomic
indicators and collections of election surveys.
The finding reveal that the AKP did not emerge as an Islamist party, but because
of its promises of economic stability and growth, and of further integration into
the EU and USA-led global order. The thesis shows that more so than its
religious discourse, the AKP’s electoral success was based on the party’s
adapting a hybrid, progressive and pro-EU position during its first tenure in
government. Second, this research demonstrates how the political conjuncture up
to 2002 and long-term economic factors provided favourable circumstances for
the AKP’s emergence.
The study’s findings also reveal that the consolidation of the AKP is mainly
attributable to its economic and social agenda, and the utilization of the public
purse and other state resources (e.g. social and health care benefits) as a means
of catering for its target constituencies. In addition, they demonstrate that once
AKP’s consolidation was completed (2010) the party’s discourse gradually
became more conservative and nationalist, giving way to more authoritarian
policies. Nonetheless, as long as economic performance and conditions remain
unchanged, the AKP continues to appeal to its social base. Consequently, this
thesis demonstrates that the gradual drift in Turkish society towards moderate
Islamic and traditional values was not the main factor in the AKP’s rise to
power. Rather, this shift can be viewed as the feedback effect of the
consolidation of the AKP process into societal structures and norms. Hence, this
work highlights the AKP’s impact on the structure of the party-system and the role of its policies in transforming Turkish society. Lastly, this study contributes
to the foundation upon which further research on Turkish politics and the party
system can continue, by exploring the dual effect of the AKP’s ruling tenure:
factors leading to the AKP’s emergence and its feedback into Turkish society
and politics
Turkey's missing swing voters: understanding the results of the 2018 Turkish elections
Turkish President Recep Tayyip Erdogan secured victory in legislative and presidential elections on 24 June. The vote ensured that Erdogan can now govern the country using new executive powers which were approved in a referendum in 2017. Sevinç Bermek and Ledün Çevik write that although there were no radical shifts in support from the last legislative elections in 2015, it is difficult to predict where Turkish politics will go from here given the changes that have been made to the country’s political system
A Pleiotrophin C-terminus peptide induces anti-cancer effects through RPTPβ/ζ
<p>Abstract</p> <p>Background</p> <p>Pleiotrophin, also known as HARP (Heparin Affin Regulatory Peptide) is a growth factor expressed in various tissues and cell lines. Pleiotrophin participates in multiple biological actions including the induction of cellular proliferation, migration and angiogenesis, and is involved in carcinogenesis. Recently, we identified and characterized several pleiotrophin proteolytic fragments with biological activities similar or opposite to that of pleiotrophin. Here, we investigated the biological actions of P(122-131), a synthetic peptide corresponding to the carboxy terminal region of this growth factor.</p> <p>Results</p> <p>Our results show that P(122-131) inhibits <it>in vitro </it>adhesion, anchorage-independent proliferation, and migration of DU145 and LNCaP cells, which express pleiotrophin and its receptor RPTPβ/ζ. In addition, P(122-131) inhibits angiogenesis <it>in vivo</it>, as determined by the chicken embryo CAM assay. Investigation of the transduction mechanisms revealed that P(122-131) reduces the phosphorylation levels of Src, Pten, Fak, and Erk<sup>1</sup>/<sub>2</sub>. Finally, P(122-131) not only interacts with RPTPβ/ζ, but also interferes with other pleiotrophin receptors, as demonstrated by selective knockdown of pleiotrophin or RPTPβ/ζ expression with the RNAi technology.</p> <p>Conclusions</p> <p>In conclusion, our results demonstrate that P(122-131) inhibits biological activities that are related to the induction of a transformed phenotype in PCa cells, by interacing with RPTPβ/ζ and interfering with other pleiotrophin receptors. Cumulatively, these results indicate that P(122-131) may be a potential anticancer agent, and they warrant further study of this peptide.</p
DNA Replication Catalyzed by Herpes Simplex Virus Type 1 Proteins Reveals Trombone Loops at the Fork
Using purified replication factors encoded by herpes simplex virus type 1 and a 70-base minicircle template, we obtained robust DNA synthesis with leading strand products of >20,000 nucleotides and lagging strand fragments from 600 to 9,000 nucleotides as seen by alkaline gel electrophoresis. ICP8 was crucial for the synthesis on both strands. Visualization of the deproteinized products using electron microscopy revealed long, linear dsDNAs, and in 87%, one end, presumably the end with the 70-base circle, was single-stranded. The remaining 13% had multiple single-stranded segments separated by dsDNA segments 500 to 1,000 nucleotides in length located at one end. These features are diagnostic of the trombone mechanism of replication. Indeed, when the products were examined with the replication proteins bound, a dsDNA loop was frequently associated with the replication complex located at one end of the replicated DNA. Furthermore, the frequency of loops correlated with the fraction of DNA undergoing Okazaki fragment synthesis
Electricity generation from disaccharides using microbial fuel cells
Bu çalışmada, lignoselülozik biyokütlelerin asit hidrolizatlarında yaygın olarak bulunan disakkaritlerden elektrik üretimi, tek odalı, hava-katot mikrobiyal yakıt hücreleri kullanılarak araştırılmıştır. Başlıca iki disakkariti (D-sellobiyoz, D-maltoz) kapsayan karbon kaynakları ile elektrik üretimi gözlenmiştir. Sodyum asetat ile zenginleştirilmiş karışık bakteri kültürü, test edilen bütün disakkaritlere kolayca adapte olmuştur. Yeni karbon kaynağına adaptasyon için gerekli süre de benzerlik gösterdi. Test edilen disakkaritler için elde edilen en yüksek güç yoğunluğu, 0.44-0.66 mA cm-2 direnç yoğunluğunda, sellobiyoz için 1262±5 mW m-2, maltoz içinse 1893±67 mW m-2 olarak bulunmuştur. Kolombik yeterlik sellobiyoz için yüzde 18, maltoz içinse yüzde 30 olarak bulunmuştur. Test edilen disakkaritler için, en yüksek volt eldesi ve substrat konsantrasyonu arasındaki ilişki 120 ohm dış dirençte doygunluk kinetiği sonuçları ile uyumluluk göstermiştir. Ön görülen en yüksek volt üretimi substratın çeşidine bağlı olarak, sellobiyoz için 0.34 V, yarı doygunluk kinetik sabiti, 626 mg L- (R2= 0.971), maltoz için ise 0.40 V ve yarı doygunluk kinetik sabiti 733 mg L-1 (R2= 0.998) olarak bulunmuştur. Test edilen disakkaritler için yüzde 81’nin üzerinde kimyasal oksijen talebinde azalma sağlanmıştır. Test edilen disakkaritlerin elektrik üretiminde karbon kaynağı olarak kullanılabileceği keşfedilmiştir. Çalışmamızın sonuçları, lignoselülozik maddelerden türevli disakkaritlerin ve lignoselüloz türevli maddelerin ön muamele ile mikrobiyal yakıt hücreleri için uygun birer karbon kaynağı olabileceklerini göstermiştir. Anahtar Kelimeler: Elektrik, disakkarit, mikrobiyal yakıt hücresi, performans.Researches on the finding renewable energy alternatives to fossil fuels have been great attention in recent years. The production of fuel and energy from lignocellulosic biomass such as agricultural residues and woody biomass has drawn significant attention because of the abundance, ready availability and renewable nature of these resources. The main components of lignocellulosic biomass are cellulose, hemicelluloses and lignin. Our previous study indeed demonstrated that all monosaccharides that can be directly generated from hydrolysis of lignocellulosic biomass were good sources for electricity generation in MFCs. However, lignocellulosic biomass cannot be directly utilized by microorganisms in MFCs for electricity generation. In other words, lignocellulosic material has to be converted to sugars or other low-molecular-weight compounds. The most commonly used method of converting lignocellulosic biomass to the sugars is through a dilute-acid pre-treatment and subsequent acid- or enzymatic hydrolysis processes. The dilute-acid pretreatment and the subsequent acid hydrolysis generate a number of byproducts, such as furan derivatives, phenolic compounds and carboxylic acids Our previous study shows that most of the phenolic compunds and furan derivatives do not have inhbitory effect on electricity generation. However, upto know, there is no information about the electricity generation in air-cathode single chamber mediator-less microbial fuel cells from tested disaccharides. The acid hydrolysates from lignocellulosic materials such as pine wood or corn stover supposedly contain severall monosaccharides and disaccaharides previously described. Our preliminary results show that sulfuric acid hydrolysation (10%) of pine wood flour generate electricity in MFCs. However, it is poorly understood whether all the disaccharides can be utilized by bacteria in an MFC for electricity generation. Microbial fuel cell (MFC) technology uses microorganisms to catalyze the direct production of electricity from organic materials, and provides a new method for green energy generation from biomass. Various organic materials, such as glucose, xylose, acetate, butyrate, lactate, etc. as well as those from waste streams such as wastewaters can be used to generate direct electicity by MFCs. In this study, the direct production of electricity from disaccharides of lignocellulosic biomass was examined MFC performances by the disaccharides were evaluated as the following parameters: (1) Voltage generation, (2) power density generation, (3) Coulobic efficiency, (4) the removal of chemical oxygen demand and the effect of substrate concentration on electricity generation. Voltage was measured using a multimeter with a data acquisition system. Power density (mW m-2) was calculated according to P=IV/A, where I is the current, V voltage, and A the projected area of the anode. Electricity was produced from all disaccharides tested, including D-maltose and D-cellobiose. The mixed bacterial culture enriched using sodium acetate as a carbon source adapted well to all carbon sources tested. The adaptation time, which was defined as the time between adding a disaccharide solution to a MFC and reaching a maximum power output at 1000 W, was similar for each disaccharide. However, once the bacteria adapted to a new disaccharide, electricity was quickly recovered when the disaccharide solution was refilled. Maximum power density obtained from these disaccharides were 1262±5 mW m-2 for D-cellobiose, 1893±67 mW m-2 for D-maltose at current density of 0.44 and 0.66 mA cm-2, respectively. For two disaccharides tested, the maximum voltage output at 120 external resistance initially increased with the disaccharide concentration; however, further increases above a certain level did not improve the electricity generation Coulombic efficiency was 18% for D-cellobiose and 30% for D-maltose. For disaccharides tested, the relationship between the maximum voltage output and the substrate concentration appeared to follow saturation kinetics at 120 external resistance. The estimated maximum voltage output ranged between 0.34-0.40 V and half-saturation kinetic constants of 626 to 733 mg L-1for D-cellobiose and D-maltose, respectively. Chemical oxygen demand (COD) removal was over 81 % for disaccharides tested. Results from this study indicated that lignocellulosic biomass-derived disaccharides might be a suitable resource for electricity generation using MFC technology. Keywords: Electricity, microbial fuel cell, disaccharide, performance
Mitochondrial Single-stranded DNA-binding Proteins Stimulate the Activity of DNA Polymerase γ by Organization of the Template DNA
The activity of the mitochondrial replicase, DNA polymerase γ (Pol γ) is stimulated by another key component of the mitochondrial replisome, the mitochondrial single-stranded DNA-binding protein (mtSSB). We have performed a comparative analysis of the human and Drosophila Pols γ with their cognate mtSSBs, evaluating their functional relationships using a combined approach of biochemical assays and electron microscopy. We found that increasing concentrations of both mtSSBs led to the elimination of template secondary structure and gradual opening of the template DNA, through a series of visually similar template species. The stimulatory effect of mtSSB on Pol γ on these ssDNA templates is not species-specific. We observed that human mtSSB can be substituted by its Drosophila homologue, and vice versa, finding that a lower concentration of insect mtSSB promotes efficient stimulation of either Pol. Notably, distinct phases of the stimulation by both mtSSBs are distinguishable, and they are characterized by a similar organization of the template DNA for both Pols γ. We conclude that organization of the template DNA is the major factor contributing to the stimulation of Pol γ activity. Additionally, we observed that human Pol γ preferentially utilizes compacted templates, whereas the insect enzyme achieves its maximal activity on open templates, emphasizing the relative importance of template DNA organization in modulating Pol γ activity and the variation among systems
Conformational landscapes of DNA polymerase I and mutator derivatives establish fidelity checkpoints for nucleotide insertion
The fidelity of DNA polymerases depends on conformational changes that promote the rejection of incorrect nucleotides before phosphoryl transfer. Here, we combine single-molecule FRET with the use of DNA polymerase I and various fidelity mutants to highlight mechanisms by which active-site side chains influence the conformational transitions and free-energy landscape that underlie fidelity decisions in DNA synthesis. Ternary complexes of high fidelity derivatives with complementary dNTPs adopt mainly a fully closed conformation, whereas a conformation with a FRET value between those of open and closed is sparsely populated. This intermediate-FRET state, which we attribute to a partially closed conformation, is also predominant in ternary complexes with incorrect nucleotides and, strikingly, in most ternary complexes of low-fidelity derivatives for both correct and incorrect nucleotides. The mutator phenotype of the low-fidelity derivatives correlates well with reduced affinity for complementary dNTPs and highlights the partially closed conformation as a primary checkpoint for nucleotide selection
The synthetic peptide P111-136 derived from the C-terminal domain of heparin affin regulatory peptide inhibits tumour growth of prostate cancer PC-3 cells
<p>Abstract</p> <p>Background</p> <p>Heparin affin regulatory peptide (HARP), also called pleiotrophin, is a heparin-binding, secreted factor that is overexpressed in several tumours and associated to tumour growth, angiogenesis and metastasis. The C-terminus part of HARP composed of amino acids 111 to 136 is particularly involved in its biological activities and we previously established that a synthetic peptide composed of the same amino acids (P111-136) was capable of inhibiting the biological activities of HARP. Here we evaluate the ability of P111-136 to inhibit <it>in vitro </it>and <it>in vivo </it>the growth of a human tumour cell line PC-3 which possess an HARP autocrine loop.</p> <p>Methods</p> <p>A total lysate of PC-3 cells was incubated with biotinylated P111-136 and pulled down for the presence of the HARP receptors in Western blot. <it>In vitro</it>, the P111-136 effect on HARP autocrine loop in PC-3 cells was determined by colony formation in soft agar. <it>In vivo</it>, PC-3 cells were inoculated in the flank of athymic nude mice. Animals were treated with P111-136 (5 mg/kg/day) for 25 days. Tumour volume was evaluated during the treatment. After the animal sacrifice, the tumour apoptosis and associated angiogenesis were evaluated by immunohistochemistry. <it>In vivo </it>anti-angiogenic effect was confirmed using a mouse Matrigel™ plug assay.</p> <p>Results</p> <p>Using pull down experiments, we identified the HARP receptors RPTPβ/ζ, ALK and nucleolin as P111-136 binding proteins. <it>In vitro</it>, P111-136 inhibits dose-dependently PC-3 cell colony formation. Treatment with P111-136 inhibits significantly the PC-3 tumour growth in the xenograft model as well as tumour angiogenesis. The angiostatic effect of P111-136 on HARP was also confirmed using an <it>in vivo </it>Matrigel™ plug assay in mice</p> <p>Conclusions</p> <p>Our results demonstrate that P111-136 strongly inhibits the mitogenic effect of HARP on <it>in vitro </it>and <it>in vivo </it>growth of PC-3 cells. This inhibition could be linked to a direct or indirect binding of this peptide to the HARP receptors (ALK, RPTPβ/ζ, nucleolin). <it>In vivo</it>, the P111-136 treatment significantly inhibits both the PC-3 tumour growth and the associated angiogenesis. Thus, P111-136 may be considered as an interesting pharmacological tool to interfere with tumour growth that has now to be evaluated in other cancer types.</p
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