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Yayın Vapor-induced film formation from low-T-g particles for different solvent compositions(Elsevier Inc, 2006-05-15) Arda, Ertan; Kara, Selim; Saraç, Ayfer; Pekcan, Mehmet ÖnderThe photon transmission method was used to study latex film formation from poly(vinyl acetate) (PVAc) particles induced by two different solvents. Films with the same latex content were prepared from PVAc particles and exposed to vapor of ethanol-water and acetone-water mixtures in various compositions. Transmitted photon intensities, I-tr, from these films increased with increasing vapor exposure time. The increase in I-tr is attributed to the increase in crossing density at the polymer-polymer junction. The Prager-Tirrell model was employed to obtain the back-and-forth frequency, v, of the reptating polymer chain during film formation induced by solvent vapor. It was observed that the produced v values increase as the solvent content is increased for both solvents. Abilities of both solvents to form films were interpreted with the solubility parameters of the solvents and the PVAc.Yayın Volumetric ultrasound imaging using 2-D CMUT arrays(IEEE-Inst Electrical Electronics Engineers Inc, 2003-11) Oralkan, Ömer; Ergün, Arif Sanlı; Cheng, Ching-Hsiang; Johnson, Jeremy A.; Karaman, Mustafa; H. Lee, Thomas; Khuri-Yakub, Butrus ThomasRecently, capacitive micromachined ultrasonic transducers (CMUTs) have emerged as a candidate to overcome the difficulties in the realization of 2-D arrays for real-time 3-D imaging. In this paper, we present the first volumetric images obtained using a 2-D CMUT array. We have fabricated a 128 x 128-element 2-D CMUT array with through-wafer via interconnects and a 420-mum element pitch. As an experimental prototype, a 32 x 64-element portion of the 128 X 128-element array was diced and flip-chip bonded onto a glass fanout chip. This chip provides individual leads from a central 16 X 16-element portion of the array to surrounding bondpads. An 8 x 16-element poition of the array was used in the experiments along with a 128-channel data acquisition system. For imaging phantoms, we used a 2.37-mm diameter steel sphere located 10 mm from the array center and two 12-mm-thick Plexiglas plates located 20 mm and 60 mm from the array. A 4 X 4 group of elements in the middle of the 8 X 16-element array was used in transmit, and the remaining elements were used to receive the echo signals. The echo signal obtained from the spherical target presented a frequency spectrum centered at 4.37 MHz with a 100% fractional bandwidth, whereas the frequency spectrum for the echo signal from the parallel plate phantom was centered at 3.44 MHz with a 91% fractional bandwidth. The images were reconstructed by using RF beamforming and synthetic phased array approaches and visualized by surface rendering and multiplanar slicing techniques. The image of the spherical target has been used to approximate the point spread function of the system and is compared with theoretical expectations. This study experimentally demonstrates that 2-D CMUT arrays can be fabricated with high yield using silicon IC-fabrication processes, individual electrical connections can be provided using through-wafer vias, and flip-chip bonding can be used to integrate these dense 2-D arrays with electronic circuits for practical 3-D imaging applications.Yayın A stochastic risk-averse framework for blood donation appointment scheduling under uncertain donor arrivals(Springer, 2020-12) Yalçındağ, Semih; Baş Güre, Seda; Carello, Giuliana; Lanzarone, EttoreBlood is a key resource in all health care systems, usually drawn from voluntary donors. We focus on the operations management in blood collection centers, which is a key step to guarantee an adequate blood supply and a good quality of service to donors, by addressing the so-called Blood Donation Appointment Scheduling problem. Its goal is to employ appointment scheduling to balance the production of blood units between days, in order to provide a reasonably constant supply to transfusion centers and hospitals, and reduce non-alignments between physicians' working times and donor arrivals at the collection center. We consider a two-phase solution framework taken from the literature, in which a deterministic linear programming model preallocates time slots to different blood types and a prioritization policy assigns the preallocated slots to the donors when they make a reservation. However, the problem is stochastic in nature and requires consideration of the uncertain arrivals of non-booked donors. In this work, to include the uncertain arrivals, we propose three stochastic counterparts of the preallocation model based on a risk-neutral objective and two risk-averse objectives, respectively, where the Conditional Value-at-Risk is considered as the risk measure in the last two methods. The resulting stochastic frameworks have been tested considering the historical data of one of the largest Italian collection centers, the Milan Department of the "Associazione Volontari Italiani Sangue" (AVIS). Results show the effectiveness of the stochastic models, especially the mean-risk one, and the need to include the uncertainty of arrivals in order to better balance the production of blood units.Yayın Computational model of the ventricular action potential in adult spontaneously hypertensive rats(2003-09-01) Padmala, Srikanth; Demir, Sıddıka SemahatIntroduction: Cardiac hypertrophy has substantial clinical significance because many hypertrophic cells have markedly prolonged repolarization behavior, which may lead to increased risk for cardiac arrhythmias. Spontaneously hypertensive rat (SHR) is one model of hypertension that is studied extensively and is considered to be the best laboratory model of human hypertension. We extended our previously published model of the rat ventricular myocyte to simulate the effects of hypertrophy in SHR. Methods and Results: In SHR it has been shown that the membrane capacitance is increased, the density of transient outward K+ current is decreased, the sarcoplasmic reticulum Ca 2+ ATPase activity is reduced, and the cell volumes are increased compared to those of the normal rat. We introduced these changes into our previous model of the rat ventricular myocyte and simulated the ventricular action potential of SHR. Our results demonstrated increased action potential duration (APD) and increased peak systolic value of the intracellular calcium transient in SHR. Simulations with reduced extracellular K+ concentration ([K+]o) have shown that there is increased APD shortening in SHR compared to that of the normal rat. Conclusions: Our computational model qualitatively simulated the electrophysiologic changes observed in SHR and provided the plausible mechanistic linkage between the prolonged APD and increased inotropy. Our model results also demonstrated the electrophysiologic changes observed with reduced [K+]o in SHR, a finding that is clinically significant in hypertensive patients with left ventricular hypertrophy undergoing diuretic treatment.Yayın Imagined contact facilitates acculturation, sometimes: contradicting evidence from two sociocultural contexts(Educational Publishing Foundation-American Psychological Assoc, 2019-10) Bağcı Hemşinlioğlu, Sabahat Çiğdem; Piyale, Zeynep Ecem; Stathi, SofiaObjective: Imagined intergroup contact has been shown to be an effective tool to improve intergroup relationships in various settings, yet the application of the strategy among minority group members and across cultures has been scarce. The current research aimed to test imagined contact effects on minority group members' acculturation strategies (contact participation and culture maintenance), perceived discrimination, feelings of belongingness, and social acceptance across three studies conducted in the United Kingdom (Study 1) and Turkey (Studies 2 and 3). Method: The sample consisted of Eastern Europeans in Study 1 (N = 63) and Kurds in Study 2 and 3 (N = 66 and 210, respectively). Participants were randomly assigned to 1 of 2 conditions (control vs. imagined contact) and completed measures of acculturation, perceived discrimination, general belongingness, and social acceptance. Results: Findings showed that while imagined contact significantly reduced perceived discrimination and culture maintenance, and increased contact participation and social acceptance among Eastern Europeans (Study 1), it reduced social acceptance and contact participation among Kurds recruited from a conflict-ridden homogeneous setting (Study 2). With a larger and more heterogeneous sample of Kurds (Study 3), these effects occurred only among those with higher ingroup identification. Moreover, in all studies social acceptance mediated the effects of imagined contact on contact participation and perceived discrimination. Discussion. Findings offer important insights about the use of the imagined contact strategy among minority group members and imply the need to take into account the context-dependent nature of contact strategies.Yayın Normative data and factorial structure of the Turkish version of the junior temperament and character inventory-revised(Taylor & Francis, 2017) Köse, Samet; Çam Çelikel, Feryal; Akın, Ercan; Kaya, Cahit; Elbozan Cumurcu, Birgül; Etikan, İlker; Cloninger, Claude RobertObjective: Junior Temperament and Character Inventory (J-TCI) was developed by Luby, Svrakic, McCallum, Przybeck, and Cloninger based on Cloninger's biopsychosocial model to assess temperament and character dimensions in children and adolescents. Methods: The Turkish version of J-TCI-Revised (J-TCI-R) was administered to 1129 elementary and middle-school (male/female, 546/583) students. Internal consistency reliabilities were measured by Cronbach's alpha; test-retest was assessed across one month. Results: Cronbach's alphas for the subscales of J-TCI-R ranged from 0.60 to 0.75 for temperament and character subscales, which were comparable to US and other populations. The correlations between baseline and one month after administration of J-TCI-R were highly and statistically significant (r = 0.578-0.674 for scales and 0.366-0.582 for subscales) (n = 795). Factor analysis results using Eigenvalue greater than one rule indicated three out of four factors for temperament scales and one out of two factors for character subscales which were similar to findings from the other countries. When all of the subscales were subjected to factor analysis, four out of six factors were retained. To our knowledge, this is the first study analysing psychometric properties and factorial construct of the J-TCI-R. Conclusions: The internal reliability coefficients and test-retest indicated a good stability of scores over time and the factorial structure was consistent with Cloninger's model of personality. The reliability and validity of the Turkish version of the TCI is therefore supported.Yayın Investigating the role of E-contact and self-disclosure on improving Turkish-Kurdish interethnic relations(Wiley, 2021-06) Bağcı Hemşinlioğlu, Sabahat Çiğdem; Güvensoy, İpek; Turner, Rhiannon; White, Fiona Ann; Piyale, Zeynep EcemWhile recent research has started to pay more attention to the role of contact strategies on promoting intergroup harmony between Turkish and Kurdish communities, the effectiveness of a novel form of indirect contact strategy, E-contact—where participants engage in a cooperative and structured online interaction with an individual from the outgroup—has not yet been tested. Across two studies (NStudy 1 = 110, NStudy 2 = 176), we investigated the effects of E-contact among Turks on promoting positive attitudes and behavioral tendencies toward Kurds, testing outgroup trust and intergroup anxiety as mediators and incorporating a distinction between lower and higher self-disclosure conditions. As expected, E-contact led to more positive outgroup attitudes, as well as greater approach tendencies and decreased avoidance tendencies through increased outgroup trust (Studies 1 and 2) and reduced intergroup anxiety (Study 2). Study 2 also found that E-contact produced lower perceived interethnic conflict through increased outgroup trust. While both lower and higher personal disclosure conditions provided similar effects in the two studies, E-contact with heightened self-disclosure was especially effective at promoting more positive outgroup attitudes and reducing avoidance tendencies. Findings highlight potential benefits of using E-contact as a prejudice-reduction strategy in conflict settings.Yayın P-T phase diagram for NH4F(Editions Scientifiques Medicales Elsevier, 2002-04) Salihoğlu, Selami; Yurtseven, Hasan Hamit; Enginer, YücelIn this study we obtain a P-T phase diagram of NH4F using the mean-field theory. We fit our calculated phase line equations to the experimental P-T phase diagram. By choosing appropriately the coefficients in the free-energy expansions. our calculated phase diagram agrees well with the experimentally observed phase diagram of NH4F.Yayın Collective victimhood beliefs among majority and minority groups: Links to ingroup and outgroup attitudes and attribution of responsibility for conflict(Pergamon-Elsevier Science Ltd, 2018-09) Bağcı Hemşinlioğlu, Sabahat Çiğdem; Piyale, Zeynep Ecem; Karaköse Çelik, Selin; Şen, EzgiWe examined perceived ingroup and outgroup victimhood beliefs across group status and how these were uniquely associated with ingroup and outgroup attitudes and attribution of responsibility among majority (Turkish, N = 141) and minority (Kurdish, N = 86) group members in Turkey. We further explored whether the extent to which collective victimhood beliefs were shared via ingroup and outgroup members predicted our dependent measures beyond the subjective perception of ingroup victimhood. Findings showed that both groups perceived higher ingroup victimhood compared to outgroup victimhood and this difference was more pronounced among the minority group. Perceived outgroup victimhood beliefs, compared to ingroup victimhood beliefs, were more closely related to intergroup outcomes, and led to more positive outgroup and more negative ingroup outcomes. Both groups shared collective victimhood beliefs more with their ingroup friends than their outgroup friends and ingroup sharing of collective victimhood was a stronger predictor of intergroup outcomes, relating to more positive ingroup and more negative outgroup outcomes. Outgroup sharing of collective victimhood was related to more positive outgroup attitudes and lower ingroup responsibility among the Turkish group, whereas it was not related to outgroup attitudes and negatively related to ingroup attribution of responsibility among the Kurdish group. Practical and theoretical implications of the findings were discussed.Yayın Evolutionary route to diploidy and sex(National Academy of Sciences, 2001-11-20) Tüzel, Erkan; Sevim, Volkan; Erzan, AyşeBy using a bit-string model of evolution, we find a successful route to diploidy and sex in simple organisms. Allowing the sexually reproducing diploid individuals to also perform mitosis, as they do in a haploid-diploid cycle, leads to the complete takeover of the population by sexual diploids. This mechanism is so robust that even the accidental conversion and pairing of only two diploids give rise to a sexual population.
