Direct transmission detection of tunable mechanical resonance in an individual carbon nanofiber relay

A direct on-chip transmission measurement of the resonance frequency of an individual singly clamped carbon nanofiber relay is reported. The experimental results are in good agreement with a small signal model and show the expected tuning of the resonance frequency with changing bias voltage

Comparison of multiple DNA dyes for real-time PCR: effects of dye concentration and sequence composition on DNA amplification and melting temperature

The importance of real-time polymerase chain reaction (PCR) has increased steadily in clinical applications over the last decade. Many applications utilize SYBR Green I dye to follow the accumulation of amplicons in real time. SYBR Green I has, however, a number of limitations that include the inhibition of PCR, preferential binding to GC-rich sequences and effects on melting curve analysis. Although a few alternative dyes without some of these limitations have been recently proposed, no large-scale investigation into the properties of intercalating dyes has been performed. In this study, we investigate 15 different intercalating DNA dyes for their inhibitory effects on PCR, effects on DNA melting temperature and possible preferential binding to GC-rich sequences. Our results demonstrated that in contrast to the results of SYBR Green I, two intercalating dyes SYTO-13 and SYTO-82 do not inhibit PCR, show no preferential binding to GC rich sequences and do not influence melting temperature, Tm, even at high concentrations. In addition, SYTO-82 demonstrated a 50-fold lower detection limit in a dilution series assay. In conclusion, the properties of SYTO-82 and SYTO-13 will simplify the development of multiplex assays and increase the sensitivity of real-time PCR

Dynamical Mean-Field Theory

The dynamical mean-field theory (DMFT) is a widely applicable approximation scheme for the investigation of correlated quantum many-particle systems on a lattice, e.g., electrons in solids and cold atoms in optical lattices. In particular, the combination of the DMFT with conventional methods for the calculation of electronic band structures has led to a powerful numerical approach which allows one to explore the properties of correlated materials. In this introductory article we discuss the foundations of the DMFT, derive the underlying self-consistency equations, and present several applications which have provided important insights into the properties of correlated matter.Comment: Chapter in "Theoretical Methods for Strongly Correlated Systems", edited by A. Avella and F. Mancini, Springer (2011), 31 pages, 5 figure

Kravvalidering : ur ett kommunikationsperspektiv

Det här arbetet börjar med en introduktion till systemutveckling och ger exempel på ett par olika tillvägagångssätt som används i Skandinavien och England. I introduktionen presenteras också problem som har funnits och kanske finns fortfarande i systemutvecklingsbranschen. Vidare belyses också hur viktig kommunikationen är mellan användare och utvecklare genom hela utvecklingsarbetet. I de tidiga faserna av systemutveckling finner man kravhantering och den introduceras kort i slutet på introduktionen för att sedan presenteras i fullo i bakgrundskapitlet. I början på bakgrundskapitlet ges ett exempel på hur en fullständig utvecklingsmodell kan vara uppbyggd och efter det tas kravhanteringens alla delar upp för att sedan avslutas i hur kravvalideringen fungerar och används. Problembeskrivningen innehåller tre delar med början på det problemområde som jag valt, nämligen kravhanteringsprocessen. Denna följs av avgränsningen i form av valideringen, och då speciellt kommunikationen i valideringsprocessen som fungerar som problemprecisering. Metodvalet visar på valet av metod samt de källor som använts med tillhörande bakgrundsinformation. Genomförandet presenterar en analys olika metodkategorier inom valideringsprocessen och undersöker dem med hjälp av tre kriterier för att få en rättvis jämförelse. I genomförandet finns också en översikt om användarmedverkan eftersom detta är en förutsättning för kommunikation mellan två parter. Sedan följer ett analyskapitel där metodkategorierna analyseras ur två perspektiv. I analyskapitlet presenteras också de erfarenheter som gjorts under detta arbete. En analys av materialet som använts sker också i samma kapitel. Till sist presenteras resultat av undersökningen och arbetet diskuteras i ett vidare perspektiv

Is sick absence related to commuting travel time? : Swedish Evidence Based on the Generalized Propensity Score Estimator

This paper focuses on the effects of commuting time on sickness insurance utilization by applying a generalized propensity score estimator to a large sample of Swedish employees. We analyse the effect of commuting time both on the probability of using sickness insurance at all and on the probability that an individual on sick leave is on so-called partial sick leave rather than being completely absent from work. Insurance utilization is in both cases defined as being ill for more than 14 days. The results indicate, in general, that individuals do not use sickness insurance because of their commuting time. However, commuting time seems to increase the risk of being on sick leave among females with relatively low annual wage earnings. The results indicate, furthermore, a relatively weak and negative relationship between the probability of being on partial sick leave and commuting time in the group of individuals who have utilized sickness insurance. The latter result applies to both men and women

Is sick absence related to commuting travel time? - Swedish Evidence Based on the Generalized Propensity Score Estimator

This paper focuses on the effects of commuting time on sickness insurance utilization by applying a generalized propensity score estimator to a large sample of Swedish employees. We analyse the effect of commuting time both on the probability of using sickness insurance at all and on the probability that an individual on sick leave is on so-called partial sick leave rather than being completely absent from work. Insurance utilization is in both cases defined as being ill for more than 14 days. The results indicate, in general, that individuals do not use sickness insurance because of their commuting time. However, commuting time seems to increase the risk of being on sick leave among females with relatively low annual wage earnings. The results indicate, furthermore, a relatively weak and negative relationship between the probability of being on partial sick leave and commuting time in the group of individuals who have utilized sickness insurance. The latter result applies to both men and women.Commuting time; Sick absence; General propensity score estimator

The value of time from subjective data on life satisfaction and job satisfaction : an empirical assessment

This paper compares estimates of the value of commuting time, working time and household working time from empirical models of subjective assessments of life satisfaction and job satisfaction, respectively, to the corresponding estimates obtained from an empirical search model of the labour market. The results indicate that all three variables produce rather high estimates of the value of commuting time. The results regarding the value of working time differ more between the different outcome variables and it is only significantly different from zero in the model of life satisfaction. Perhaps less surprisingly, the estimate of the value of household working time is also only significantly different from zero in the model of life satisfaction in contrast to the models of job satisfaction and job durations where it is insignificantly different from zero. This paper compares estimates of the value of commuting time, working time and household working time from empirical models of subjective assessments of life satisfaction and job satisfaction, respectively, to the corresponding estimates obtained from an empirical search model of the labour market. The results indicate that all three variables produce rather high estimates of the value of commuting time. The results regarding the value of working time differ more between the different outcome variables and it is only significantly different from zero in the model of life satisfaction. Perhaps less surprisingly, the estimate of the value of household working time is also only significantly different from zero in the model of life satisfaction in contrast to the models of job satisfaction and job durations where it is insignificantly different from zero

Evaluation of four surface surrogates for modeling lung tumor positions over several fractions in radiotherapy

Patient breathing during lung cancer radiotherapy reduces the ability to keep a sharp dose gradient between tumor and normal tissues. To mitigate detrimental effects, accurate information about the tumor position is required. In this work, we evaluate the errors in modeled tumor positions over several fractions of a simple tumor motion model driven by a surface surrogate measure and its time derivative. The model is tested with respect to four different surface surrogates and a varying number of surrogate and image acquisitions used for model training. Fourteen patients were imaged 100 times with cine CT, at three sessions mimicking a planning session followed by two treatment fractions. Patient body contours were concurrently detected by a body surface laser scanning system BSLS from which four surface surrogates were extracted; thoracic point TP, abdominal point AP, the radial distance mean RDM, and a surface derived volume SDV. The motion model was trained on session 1 and evaluated on sessions 2 and 3 by comparing modeled tumor positions with measured positions from the cine images. The number of concurrent surrogate and image acquisitions used in the training set was varied, and its impact on the final result was evaluated. The use of AP as a surface surrogate yielded the smallest error in modeled tumor positions. The mean deviation between modeled and measured tumor positions was 1.9 mm. The corresponding deviations for using the other surrogates were 2.0 mm (RDM), 2.8 mm (SDV), and 3.0 mm (TP). To produce a motion model that accurately models the tumor position over several fractions requires at least 10 simultaneous surrogate and image acquisitions over 1–2 minutes

The value of time from subjective data on life satisfaction and job satisfaction: An empirical assessment

This paper compares estimates of the value of commuting time, working time and household working time from empirical models of subjective assessments of life satisfaction and job satisfaction, respectively, to the corresponding estimates obtained from an empirical search model of the labour market. The results indicate that all three variables produce rather high estimates of the value of commuting time. The results regarding the value of working time differ more between the different outcome variables and it is only significantly different from zero in the model of life satisfaction. Perhaps less surprisingly, the estimate of the value of household working time is also only significantly different from zero in the model of life satisfaction in contrast to the models of job satisfaction and job durations where it is insignificantly different from zero. This paper compares estimates of the value of commuting time, working time and household working time from empirical models of subjective assessments of life satisfaction and job satisfaction, respectively, to the corresponding estimates obtained from an empirical search model of the labour market. The results indicate that all three variables produce rather high estimates of the value of commuting time. The results regarding the value of working time differ more between the different outcome variables and it is only significantly different from zero in the model of life satisfaction. Perhaps less surprisingly, the estimate of the value of household working time is also only significantly different from zero in the model of life satisfaction in contrast to the models of job satisfaction and job durations where it is insignificantly different from zero.Life satisfaction; job satisfaction; job search; value of time