Effects of polishing procedures on color stability of composite resins

The purpose of this study was to investigate the effect of different polishing methods on color stability of posterior, universal and nanohybrid composite resin restorative materials upon exposure to a staining agent. Twenty-five specimens were prepared for each of 5 different composite resins (Filtek Z250, Filtek P60, Quadrant LC, Grandio and Filtek Supreme). Specimens were divided into 5 groups and different polishing procedures, including polishing discs (Pd), polishing discs then diamond polishing paste (PdP), polishing discs then a liquid polishing system (Biscover) (PdB), and combinations of these (PdPB) were used. Unpolished specimens served as the control (C). The specimens were stored for 48 h in a coffee solution. The color of all specimens was measured before and after exposure with a colorimeter, and total color change (DE*) were calculated. The data were analyzed with a two-way ANOVA and the means were compared by Tukey HSD test (a=0.05). The lowest color difference was observed in the groups PdP and C, while the highest color difference was observed in PdPB, and PdB. When comparing the five different restorative materials, no significant difference was observed between FiltekP60 and FiltekZ250, and these materials demonstrated significantly less color change than Quadrant LC and the nanohybrid materials (Grandio, Filtek Supreme). The posterior (Filtek P60) and universal (Filtek Z250) composite resin restorative materials, which do not contain tetraethyleneglycol dimethacrylate (TEGDMA), were found to be less stainable than the nanohybrid (Grandio, Filtek Supreme) and universal (Quadrant LC) composite resins, which contain TEGDMA. The use of diamond polishing paste after polishing with polishing discs significantly decreased staining when compared to the groups that used polishing discs alone, for all restorative materials tested. The highest color change values were obtained for the specimens that were polished with the Biscover liquid polish system (PdB and PdPB groups)

Dopamine systems and biological rhythms: Let’s get a move on

How dopamine signaling regulates biological rhythms is an area of emerging interest. Here we review experiments focused on delineating dopamine signaling in the suprachiasmatic nucleus, nucleus accumbens, and dorsal striatum to mediate a range of biological rhythms including photoentrainment, activity cycles, rest phase eating of palatable food, diet-induced obesity, and food anticipatory activity. Enthusiasm for causal roles for dopamine in the regulation of circadian rhythms, particularly those associated with food and other rewarding events, is warranted. However, determining that there is rhythmic gene expression in dopamine neurons and target structures does not mean that they are bona fide circadian pacemakers. Given that dopamine has such a profound role in promoting voluntary movements, interpretation of circadian phenotypes associated with locomotor activity must be differentiated at the molecular and behavioral levels. Here we review our current understanding of dopamine signaling in relation to biological rhythms and suggest future experiments that are aimed at teasing apart the roles of dopamine subpopulations and dopamine receptor expressing neurons in causally mediating biological rhythms, particularly in relation to feeding, reward, and activity

Subharmonic resonance in a limit cycling voltage regulator

In practice, thyristor rectifiers are used as high current-low voltage power supplies. Under certain conditions such rectifiers introduce subharmonic resonances. In this paper, a limit cycling voltage regulator system is simulated in the digital computer. The reference voltage and load are varied and the system gain is changed for better understanding of their effects on the subharmonics. A Fourier analysis of the output wave shape then determined the existence and amplitude of subharmonic components.http://archive.org/details/subharmonicreson00guleLieutenant, Junior Grade, Turkish NavyApproved for public release; distribution is unlimited

Circuit lengths of graphs for the Picard group

In this paper, we examine some properties of suborbital graphs for the Picard group. We obtain edge and circuit conditions, then propose a conjecture for the graph to be forest. This paper is an extension of some results in (Jones et al. in The Modular Group and Generalized Farey Graphs, pp. 316-338, 1991)

Psychopathology in Down Syndrome

The main aim of this section is to provide clinicians with a guide to the prevalence of psychopathologies, associated factors, and their treatment in children with Down syndrome (DS). Attention-deficit/hyperactivity disorder (ADHD), behavioral disorders, depression, and autism are more common in DS than the normal population. However, the incidence of psychopathology is generally lower in DS than in other diseases that cause mental retardation. While writing this chapter, approximately 200 articles in electronic databases were scanned using the keywords “Down Syndrome and Psychopathology,” “Down Syndrome and Mood Disorder,” “Down Syndrome and Autism,” “Down Syndrome and Anxiety,” “Down Syndrome and Catatonia,” and “Down Syndrome and Behavioral Disorder.” Psychopathologies in DS will be presented in eight subtitles beginning with the most often diagnosed. It is important to perform psychological evaluations of patients with DS during routine follow-ups. Comorbid diseases (obstructive sleep apnea, cardiac pathologies, etc.) should be taken into account when choosing drugs

Is there any Effect of Core Exercises on Anaerobic Capacity in Female Basketball Players?

This study was planned in order to determine the effect of core exercises on anaerobic capacity of female basketball players. Twelve female athletes who play basketball participated in the study voluntarily. The athletes had 3 sets of repetitive core exercise program performed 4 days a week for 8 weeks at the end of their basketball trainings. The height of the athletes was 165 ± 6.57 cm, body weight was 58.73 ± 7.42 kg, age was 19.75 ± 1.05, and athletic age was 6.11 ± 2.11. According to the analysis of the results, peak power, average power, right and left hand grip strengths and right and left arm fat percentages of post-tests were found to have a statistically significant difference than the pre-tests (p <0.05). To sum up, there are very few studies on the anaerobic capacity of female basketball players, especially on the upper extremities. It is observed that basketball players have a stronger anaerobic capacity in attack and defense and that core exercises have a positive effect on certain basketball-specific technical skills such as passing, shooting, dribbling and defensive movements, and in this sense, they will also increase the performance of the athletes

Düzenleyici Kurumların Türk Spor Kulüplerinde Entelektüel Sermaye Oluşumuna Etkileri ve Bir Araştırma

Bu çalışmanın amacı BIST’de işlem gören spor kulüplerinin entelektüel sermaye değerlerini ölçerek, spor kulüplerinin mali yapısını düzenleyen ve denetleyen kurumlardan biri olan UEFA’nın ortaya koyduğu Finansal Fair Play kriterlerinin, kulüplerin entelektüel sermayeleri üzerinde etkilerini ölçmektir. Bu amaç ışığında çalışma üç bölümden oluşmuştur. Birinci bölümde entelektüel sermaye hakkında genel bilgi verilmiş, ikinci bölümde konuyla ilgili literatüre yer verilmiş, üçüncü bölümü olan uygulama kısmında, entelektüel sermayeyi işletme bazında ölçen Piyasa Değeri ve Defter Değeri, Tobin’in Q Değeri, Hesaplanmış Maddi Olmayan Değer ve Ekonomik Katma Değer yöntemlerin her biri ile spor kulüplerinin son 10 yıllık ES değerleri ve tutarları bulunmuştur. Hesaplamalardan elde edilen veriler FFP kapsamında değerlendirilerek çalışma sonlandırılmıştır

Türk idare tarihinde sosyal devlet anlayışının topluma yansıtılması açısından vakıf medeniyetinin yeri

İnsanlığın ilk dönemlerinde varlık sahipleri, servetlerini başkalarının ihtiyacını karşılamak amacıyla dünyevi beklenti olmadan vakfederdi. Batı dünyasında 19.yüzyılda sosyal devlet kurumları, vatandaşların devlete bağlılığını artıracağına inanılarak desteklenmiştir. Türk idare tarihinde ise, İslam medeniyeti dairesine girilmeden önce göçebe hayat sürülen dönemde, zenginlikler sahip olunan hayvan varlığına dayanırdı. Hükümdarlar baharda yapılan toyda zenginliklerini ihtiyaç sahiplerine verir, ekonomik açıdan sıradan vatandaş gibi yönetim görevini üstlenirdi. İslamiyet’te Hz. Peygamberin (sav) sahip olduğu hurmalıkları vakfetmesiyle kurumsallaşma yaygınlaşmış yardım faaliyetleri toplumda ayrım gözetmeden karşılık beklemeden yürütülmüştür. Türkler İslamiyet’i benimseyince vakıf faaliyetleriyle çağlarına damga vurmuş, canlılarla ilgili konularda vakıflar kurularak toplumda sınıf çatışmaları önlenmiştir. Osmanlı Devleti’nde mükemmelleşen vakıflar güvenlik ve adalet dışındaki faaliyetleri kapsayacak şekilde hizmetlerini genişletmiştir. Osmanlı Devleti’nde 18.yüzyıl sonrasında başlayan bozulmadan vakıflar etkilenmiş, işlevlerini yapamamış, varlıkları yağmalanmıştır. Hizmetleri karşılığında vatandaştan katkı talep etmeyen vakıflar günümüzde yardımlara aracılık ederek tarihi misyonundan uzaklaşmıştır. Çalışmada vakıf müessesesinin Türk-İslam medeniyetindeki gelişimi, idare tarihi içerisindeki sosyal sorumlukların yerine getirilmesindeki rolü incelenecektir

RdgB2 is required for dim-light input into intrinsically photosensitive retinal ganglion cells.

A subset of retinal ganglion cells is intrinsically photosensitive (ipRGCs) and contributes directly to the pupillary light reflex and circadian photoentrainment under bright-light conditions. ipRGCs are also indirectly activated by light through cellular circuits initiated in rods and cones. A mammalian homologue (RdgB2) of a phosphoinositide transfer/exchange protein that functions in Drosophila phototransduction is expressed in the retinal ganglion cell layer. This raised the possibility that RdgB2 might function in the intrinsic light response in ipRGCs, which depends on a cascade reminiscent of Drosophila phototransduction. Here we found that under high light intensities, RdgB2(-/-) mutant mice showed normal pupillary light responses and circadian photoentrainment. Consistent with this behavioral phenotype, the intrinsic light responses of ipRGCs in RdgB2(-/-) were indistinguishable from wild-type. In contrast, under low-light conditions, RdgB2(-/-) mutants displayed defects in both circadian photoentrainment and the pupillary light response. The RdgB2 protein was not expressed in ipRGCs but was in GABAergic amacrine cells, which provided inhibitory feedback onto bipolar cells. We propose that RdgB2 is required in a cellular circuit that transduces light input from rods to bipolar cells that are coupled to GABAergic amacrine cells and ultimately to ipRGCs, thereby enabling ipRGCs to respond to dim light