Hearing impairment risk and interaction of folate metabolism related gene polymorphisms in an aging study

<p>Abstract</p> <p>Background</p> <p>Recent investigations demonstrated many genetic contributions to the development of human age-related hearing impairment (ARHI), however, reports of factors associated with a reduction in the ARHI risk are rare. Folate metabolism is essential for cellular functioning. Despite the extensive investigations regarding the roles of folate metabolism related gene polymorphisms in the pathophysiology of complex diseases, such as cancer, cardio-cerebrovascular disease, and atherosclerosis, little is known about the association with ARHI. The aim of this study is to investigate the effects of the methionine synthase (MTR) A2756G and methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphisms on the risk of hearing impairment in middle-aged and elderly Japanese.</p> <p>Methods</p> <p>Data were collected from community-dwelling Japanese adults aged 40-84 years who participated in the Longitudinal Study of Aging biennially between 1997 and 2008. We analyzed cumulative data (5,167 samples in accumulated total) using generalized estimating equations.</p> <p>Results</p> <p>The MTHFR 677T allele was significantly associated with a reduced risk of hearing impairment only when the subjects were wild-type homozygotes for MTR A2756G. The per-T allele odds ratio of MTHFR for the risk of developing hearing impairment was 0.7609 (95% CI: 0.6178-0.9372) in the MTR AA genotype. In addition, a subgroup analysis demonstrated that the favorable effect of the MTHFR 677T allele on the risk of developing hearing impairment was independent of folate and homocysteine level, whereas plasma total homocysteine level was independently associated with an increased risk of developing hearing impairment. The interactive effect of gene polymorphisms associated with folate metabolism may modify the risk of developing hearing impairment after middle age. These results contribute to the elucidation of the causes of ARHI.</p> <p>Conclusions</p> <p>The present study has found that the MTHFR 677T allele has a favorable effect on a risk of hearing impairment in the middle-aged and elderly population, only when the individuals were wild-type homozygotes for MTR A2756G.</p

Guidelines for Designing Social Robots as Second Language Tutors

In recent years, it has been suggested that social robots have potential as tutors and educators for both children and adults. While robots have been shown to be effective in teaching knowledge and skill-based topics, we wish to explore how social robots can be used to tutor a second language to young children. As language learning relies on situated, grounded and social learning, in which interaction and repeated practice are central, social robots hold promise as educational tools for supporting second language learning. This paper surveys the developmental psychology of second language learning and suggests an agenda to study how core concepts of second language learning can be taught by a social robot. It suggests guidelines for designing robot tutors based on observations of second language learning in human–human scenarios, various technical aspects and early studies regarding the effectiveness of social robots as second language tutors

Perceptions of students and teachers participating in a science festival regarding science and scientists

Background: Numerous studies have been conducted to identify students’ perceptions of science and scientists since the 1950s. Those studies have revealed that students have stereotypical perceptions, on which teachers may have a significant effect. It is, therefore, essential to determine both teachers’ and students’ perceptions. Purpose: The aim of this study is to investigate students’ and teachers’ perceptions of science and scientists. Sample: The sample for the study consisted of 85 students and 47 teachers who participated in a science festival. Design and methods: The study is based on a descriptive survey model. Data were collected using the Draw-A-Scientist Test (DAST) and Word Association Test (WAT), and analyzed using content analysis. Results: Participants’ drawings focused on scientists’ physical characteristics, type of activity, working environment and the materials used while conducting experiments. A scientist was often depicted as a man in a lab coat with strange hair and eyeglasses and using laboratory materials. Teachers made more detailed drawings of scientists’ working style and environment and more detailed associations with the nature of science, ways of acquiring scientific knowledge and scientific process. Unlike teachers, students emphasized space-related concepts both in their drawings and word associations. Conclusion: This study shows that both teachers and students possess various stereotypical perceptions of scientists aligned with the previous studies. However, the number of scientists drawn as happy and female is higher than the previous studies, which is a promising finding. Moreover, students’ drawings consisting symbols or alternative images that evoked space in particular is one of the several aspects which differentiate this study from most studies. This study also shows that using drawings and word association tests together provides a richer understanding of people’s views of science and scientists than using only one measurement tool. © 2020, © 2020 Informa UK Limited, trading as Taylor & Francis Group

Frame-level complexity control in H.264 video coding [H.264 video kodlamada çerçeve seviyesinde karmaşiklik kontrolü]

2007 IEEE 15th Signal Processing and Communications Applications, SIU -- 11 June 2007 through 13 June 2007 -- Eskisehir -- 73089H.264 video coding standard supports several interprediction coding modes that use macroblock partitions with variable block sizes. Unfortunately, searching for optimal motion vectors of each possible partition incurs a heavy computational cost. In this paper, we propose a novel frame-level complexity control algorithm that determines for each macroblock which partitions are likely to be optimal. Motion vector search is carried out for only the selected partitions, thus reducing the complexity of the motion estimation step. The mode selection criteria is based on a measure of spatio-temporal activity within the macroblock. For each frame, the procedure guarantees that an execution time budget is met with minimum loss of coding efficiency. Simulation results show that the algorithm speeds up integer-pel motion estimation by a factor of up to 40 with less than 0.2 dB loss in coding efficiency

Facile preparation of reduced graphene oxide, polypyrrole, carbon black, and polyvinyl alcohol nanocomposite by electrospinning: a low-cost and sustainable approach for supercapacitor application

The design and synthesis of nanostructures have played an essential role in the supercapacitor field. In this paper, nanofiber composites including graphene oxide (GO), polypyrrole (PPy), carbon black (CB), and polyvinyl alcohol (PVA) as GO/PPy/PVA, rGO/PPy/PVA, GO/PPy/CB/PVA, and rGO/PPy/CB/PVA were synthesized using an easy, low cost, and sustainable approach, which is the electrospinning technique. Nanofiber composites were characterized by Fourier transform infrared spectroscopy–attenuated total reflectance (FTIR–ATR), X-ray powder diffraction (XRD), scanning electron microscopy–energy dispersive X-ray (SEM-EDX), thermogravimetric and differential thermal analysis (TGA-DTA), and solid-state conductivity analysis. Device performances were tested by cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS) analysis. The Randles circuit model of Rs(CdlRct)) was adopted to understand the dynamic parameters such as: the solution resistance (Rs), the double layer capacitance (Cdl), and the charge transfer resistance (Rct). The highest specific capacitances were obtained as Csp= 951 F/g by the CV method, Csp= 272 F/g by the GCD method, and Csp= 140.3 F/g by the EIS method for rGO/PPy/CB/PVA nanofiber composites. It is supported by other results such as phase angle (?= 66°) and solid conductivity (625 S/cm). Therefore, the encouraging results of rGO/PPy/CB/PVA nanofiber show the potential of this nanocomposite as a promote electrodes for flexible supercapacitors due to the considerable specific capacitance, the excellent cycling retention and the important power and energy densities. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.This work is a part of the research project NKUBAP.01.?NAP.19.213 approved by the Scientific and Research Project Unit (Tekirdag Namik Kemal University). This research grant is gratefully acknowledged

Modelling of GO/PPy/CB and rGO/PPy/CB nanocomposite supercapacitors using an electrical equivalent circuit

In this study, supercapacitor device performances of graphene oxide (GO), reduced graphene oxide (rGO), polypyrrole (PPy), and ternary nanocomposites of GO, PPy, and carbon black (CB) as GO/PPy/CB and rGO/PPy/CB were firstly prepared using the in situ polymerization method. The obtained composite materials were characterized by scanning electron microscopy energy–dispersive X-ray (SEM–EDX), Fourier-transform infrared-attenuated transmission reflectance (FTIR-ATR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), atomic force microscopy (AFM), Brunauer–Emmett–Teller (BET) surface area analysis, cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopic (EIS) methods. The highest specific capacitance (Csp) of the rGO/PPy/CB nanocomposite was obtained as Csp = 39, 48, and 27.86 F × g?1 by three methods of CV, GCD, and EIS, respectively. Two equivalent circuit models of Rs(CdlRct) and LRs(QRct) were presented to compare equivalent circuit parameters. Theoretical and experimental values are compatible with each other. Graphical abstract: [Figure not available: see fulltext.]. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.Trakya ÜniversitesiThis work is a part of the research project NKUBAP.01.?NAP.19.213 approved by the Scientific and Research Project Unit (Tekirdag Namik Kemal University). This research grant is gratefully acknowledged. We thank Prof. Dr. Murat Turkyilmaz and Ozan Yoruk (PhD student) for TGA and BET measurements (TUTAGEM, Trakya University, Turkey)

Synthesizing, Chitosan Coating and Detecting The Nanotoxic Effect of The Lead Selenıde (Pbse) Quantum Dots

Researches on nano-structured materials (<100 nm) are increasing rapidly in the direction of technological developments. Synthesis and modification of quantum dots, known as nanomaterials and nanocrystals, have become an important aspect of nanotechnology. The reason for this is that it has many potential applications in the field, including biomedicine and pharmacology. The unique properties and biological effects of nanostructured particles indicate that they can potentially be used as an alternative in the treatment of various diseases. In this work, PbSe quantum dots were synthesized by chemical method and modified by chitosan coating. The characterization of PbSe was done by TEM, SEM, XRD, DLS and Zeta potential analysis methods. When the morphological structures of the quantum dots obtained by chemical synthesis were examined, round and spherical nanosized particles (<20 nm) of all PbSe were obtained according to TEM and SEM results. It has been seen that PbSe quantum dots have a positive (+) surface charge and are highly stable (40 + mV). In addition, the increase in oxidation resistance of PbSe coated with chitosan was found in XRD results. As a result of this research, small size and biopolymer coated and thus more stable quantum dots could be obtained. It has also been found that PbSe quantum dots coated with biopolymers like chitosan may have the potential to be used in pharmacology and biomedical application

Relationship of admission mean platelet volume with no-reflow in acute myocardial infarction treated with fibrinolysis

Platelets play a central role in the pathogenesis of acute coronary syndromes. Mean platelet volume (MPV) is a controversial issue in platelet reactivity, the extent of coronary artery disease, and response to reperfusion therapy. Thus, we sought to determine the relationship of admission MPV and no-reflow in patients with acute STsegment elevation myocardial infarction (STEMI) treated with fibrinolysis. 164 patients (143 male, 21 female) who had presented with STEMI treated with fibrinolysis and had undergone coronary angiography, were included in our study. Blood samples for MPV estimation were obtained on admission. All angiograms were assessed with respect to TIMI flow scale in infarct-related artery. Patients were divided in two groups: group 1 with reflow (TIMI=3, n = 42) and group 2 with no-reflow (TIMI<3, n = 122). Both univariate and multivariate analyses were performed on clinical and laboratory factors with relation to angiographic reperfusion. All characteristics were similar between the two groups. MPV was not associated with no-reflow (p=0.504). Multivariate analysis determined that RCA as an IRA was independent predictor of angiographic reperfusion. No-reflow phenomenon was observed significantly fewer when RCA was an IRA (odds ratio 2.6, 95% confidence interval 1.2 to 5.3, p=0.009). Our study showed that MPV is not related to angiographic reperfusion in patients with STEMI treated with fibrinolysis