398 research outputs found
Nanoimprinted strain-controlled elastomeric gratings for optical wavelength tuning
We demonstrate strain-controlled gratings made of an organic elastomer, polydimethylsiloxane (PDMS), which can achieve optical wavelength tuning by varying their spatial periods. The whole device structure presented in this work incorporates a nanoimprinted PDMS grating integrated with electrostatic microelectromechanical systems actuators on a silicon chip. The fabrication of the device combines polymer soft lithography, nanoimprint lithography, and silicon micromachining across multiscale dimensions ranging from a few hundred nanometers to a few millimeters. The fine tuning capability with fast dynamic response of our PDMS/silicon hybrid optical grating device makes it attractive for use in various micro-optical instruments.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87849/2/161113_1.pd
Three Tramp Dacetine Ants in Taiwan
Trabalho de projeto do mestrado em Economia (Economia Financeira), apresentado Ă Faculdade de Economia da Universidade de Coimbra.Neste trabalho, as taxas forward foram utilizadas para prever os valores futuros da
Estrutura de Prazo das Taxas de Juro, em diferentes pontos desta estrutura, e em diferentes
contextos do sistema financeiro, e abrange o perĂodo que vai do final de 2004 ao final de
2014. As taxas spot e forward foram construidas a partir do modelo de Nelson, Siegel e
Svensson (1994), e para a anlisar a relação existente entre estes dois tipos de taxas,
recorreu-se o mĂ©todo de cointegração proposto por Johansen (1988, 1991). Para perĂodos
mais curtos, foram construĂdas taxas forward instantâneas, que antecipam as taxas spot
instantâneas a distâncias que vĂŁo de 1 a 10 dias. Para perĂodos mais longos, foram
construĂdas taxas forward com prazo de 1 mĂŞs, que antecipam as taxas spot com o mesmo
prazo, a distâncias que vão de 1 a 12 meses. Nas taxas instantâneas, verificou-se que existe
cointegração entre todas as taxas forward e as taxas spot que antecipam, nas estimações
que abrangem a totalidade da amostra, e para alguns casos quando se divide a amostra em
sub-perĂodos. Nas taxas mensais, pelo contrário, apenas em alguns casos foi constatada a
existĂŞncia de cointegração, quer para a totalidade do perĂodo quer para os sub-perĂodos. De
seguida, foi estimado o Modelo de Correção dos Erros proposto por Johansen (1988,
1991), e recorreu-se à analise da função impulso-resposta, para as taxas cointegradas. As
taxas mensais apresentaram sempre um comportamento mais instável, quando comparadas
com as taxas instantâneas. Entretanto, com a divisĂŁo do perĂodo, as taxas instantâneas
apresentaram um comportamento instável, principalmente para o sub-perĂodo 2012-2014
Activation of Sp1-mediated transcription by Rta of Epstein–Barr virus via an interaction with MCAF1
Rta is a transcription factor encoded by BRLF1 of the Epstein–Barr virus (EBV). This factor is expressed during the immediate-early stage of the lytic cycle to activate the genes required for EBV lytic development. Although transcription activation by Rta is frequently associated with the binding of Rta to the Rta-response element (RRE) in promoters, Rta sometimes activates promoters without an RRE. Here we show that Rta interacts with an Sp1-interacting protein, MBD1-containing chromatin-associated factor 1 (MCAF1). This interaction is critical to the formation of an Sp1–MCAF1–Rta complex at Sp1 sites. Therefore, following lytic induction and the expression of Rta, Rta increases Sp1-mediated transcription. The genes that are thus activated include p16, p21, SNRPN and BRLF1. However, the binding of Rta to RRE prevents the interaction between Rta and MCAF1; therefore, transcription activation by RRE depends only on Rta, and not on MCAF1 or Sp1. Furthermore, this study finds that MCAF1 promotes the expression of Rta and Zta from EBV, indicating that MCAF1 participates EBV lytic activation. Our study documents the critical role of Rta in regulating the transcription of the genes that are mediated by Sp1
Clinical Study The Clinical Investigation of Disparity of Utility Values Associated with Gallstone Disease: A Pilot Study
. Purpose. The utility evaluation was an effective method to incorporate all of the contributing variables for multiple diseases into one outcome measure. A cross-sectional study was conducted to assess the utility values associated with varying states of gallstone disease among outpatient clinics participants at a teaching hospital in Taipei, Taiwan. Methods. The utility values were measured by using time trade-off method. A total of 120 outpatient clinics participants (30 subjects with no gallstone disease, 30 subjects with single stone, 30 subjects with multiple stones, and 30 subjects with cholecystectomy) evaluated utility values from January 1, 2006 to December 31, 2006. The diagnosis of gallstone disease was performed by a panel of specialists using ultrasound sonography. Results. The overall mean utility value was 0.89 ± 0.13 (95% CI: 0.87-0.91) indicating that study participants were willing to trade about 11% (95% CI: 9-13%) of their remaining life in return for being free of gallstone disease perpetually. The significant associated factors of utility values based on the multiple linear regression analysis were older age and different degrees of gallstone disease. Conclusion. Our results found that in addition to older age, multiple stones and cholecystectomy could influence utility values from the patient's preference-based viewpoint
The Clinical Investigation of Disparity of Utility Values Associated with Gallstone Disease: A Pilot Study
Purpose. The utility evaluation was an effective method to incorporate all of the contributing variables for multiple diseases into one outcome measure. A cross-sectional study was conducted to assess the utility values associated with varying states of gallstone disease among outpatient clinics participants at a teaching hospital in Taipei, Taiwan. Methods. The utility values were measured by using time trade-off method. A total of 120 outpatient clinics participants (30 subjects with no gallstone disease, 30 subjects with single stone, 30 subjects with multiple stones, and 30 subjects with cholecystectomy) evaluated utility values from January 1, 2006 to December 31, 2006. The diagnosis of gallstone disease was performed by a panel of specialists using ultrasound sonography. Results. The overall mean utility value was 0.89±0.13 (95% CI: 0.87–0.91) indicating that study participants were willing to trade about 11% (95% CI: 9–13%) of their remaining life in return for being free of gallstone disease perpetually. The significant associated factors of utility values based on the multiple linear regression analysis were older age and different degrees of gallstone disease. Conclusion. Our results found that in addition to older age, multiple stones and cholecystectomy could influence utility values from the patient’s preference-based viewpoint
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