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Utilisation of physician services in the 50+ population: the relative importance of individual versus institutional factors in 10 European countries.

PubMed

Bolin, Kristian; Lindgren, Anna; Lindgren, Björn; Lundborg, Petter

2009-03-01

We analysed the relative importance of individual versus institutional factors in explaining variations in the utilisation of physician services among the 50+ in ten European countries. The importance of the latter was investigated, distinguishing between organisational (explicit) and cultural (implicit) institutional factors, by analysing the influence of supply side factors, such as physician density and physician reimbursement, and demand side factors, such as co-payment and gate-keeping, while controlling for a number of individual characteristics, using cross-national individual-level data from SHARE. Individual differences in health status accounted for about 50% of the between-country variation in physician visits, while the organisational and cultural factors considered each accounted for about 15% of the variation. The organisational variables showed the expected signs, with higher physician density being associated with more visits and higher co-payment, gate-keeping, and salary reimbursement being associated with less visits. When analysing specialist visits separately, however, organisational and cultural factors played a greater role, each accounting for about 30% of the between-country variation, whereas individual health differences only accounted for 11% of the variation.
Mølmer-Sørensen entangling gate for cavity QED systems

NASA Astrophysics Data System (ADS)

Takahashi, Hiroki; Nevado, Pedro; Keller, Matthias

2017-10-01

The Mølmer-Sørensen gate is a state-of-the-art entangling gate in ion trap quantum computing where the gate fidelity can exceed 99%. Here we propose an analogous implementation in the setting of cavity QED. The cavity photon mode acts as the bosonic degree of freedom in the gate in contrast to that played by the phonon mode in ion traps. This is made possible by utilising cavity assisted Raman transitions interconnecting the logical qubit states embedded in a four-level energy structure, making the ‘anti-Jaynes-Cummings’ term available under the rotating-wave approximation. We identify practical sources of infidelity and discuss their effects on the gate performance. Our proposal not only demonstrates an alternative entangling gate scheme but also sheds new light on the relationship between ion traps and cavity QED, in the sense that many techniques developed in the former are transferable to the latter through our framework.
Multiplexed charge-locking device for large arrays of quantum devices

NASA Astrophysics Data System (ADS)

Puddy, R. K.; Smith, L. W.; Al-Taie, H.; Chong, C. H.; Farrer, I.; Griffiths, J. P.; Ritchie, D. A.; Kelly, M. J.; Pepper, M.; Smith, C. G.

2015-10-01

We present a method of forming and controlling large arrays of gate-defined quantum devices. The method uses an on-chip, multiplexed charge-locking system and helps to overcome the restraints imposed by the number of wires available in cryostat measurement systems. The device architecture that we describe here utilises a multiplexer-type scheme to lock charge onto gate electrodes. The design allows access to and control of gates whose total number exceeds that of the available electrical contacts and enables the formation, modulation and measurement of large arrays of quantum devices. We fabricate such devices on n-type GaAs/AlGaAs substrates and investigate the stability of the charge locked on to the gates. Proof-of-concept is shown by measurement of the Coulomb blockade peaks of a single quantum dot formed by a floating gate in the device. The floating gate is seen to drift by approximately one Coulomb oscillation per hour.
Southeastern United States wood pellets as a global energy resource: a cradle-to-gate life cycle assessment derived from empirical data

NASA Astrophysics Data System (ADS)

Morrison, Brandon; Golden, Jay S.

2018-02-01

Given increased policies driving renewable electricity generation and insufficient local production of woody biomass, many countries are reliant upon the importation of wood pellets. Of current wood pellet exports, the vast majority originates from the Southeastern United States (US). In this paper we present results from a cradle-to-gate, attributional process life cycle assessment in which two production scenarios of wood pellets were modelled for the Southeastern US: one utilising roundwood from a silviculture operation and the other utilising sawmill residues. The system boundary includes all steps from harvesting of the wood biomass, through delivery of the finished wood pellets to a US port facility. For each of the impact categories assessed, wood pellets from sawmill residues resulted in higher values, ranging from 5% to 31%. In relation to Global Warming Potential, roundwood pellets resulted in a 13-21% lower value than pellets produced from sawmill residues, depending upon the allocation method.
Does charging different user fees for primary and secondary care affect first-contacts with primary healthcare? A systematic review

PubMed Central

Hone, Thomas; Lee, John Tayu; Majeed, Azeem; Conteh, Lesong; Millett, Christopher

2017-01-01

Abstract Policy-makers are increasingly considering charging users different fees between primary and secondary care (differential user charges) to encourage utilisation of primary health care in health systems with limited gate keeping. A systematic review was conducted to evaluate the impact of introducing differential user charges on service utilisation. We reviewed studies published in MEDLINE, EMBASE, the Cochrane library, EconLIT, HMIC, and WHO library databases from January 1990 until June 2015. We extracted data from the studies meeting defined eligibility criteria and assessed study quality using an established checklist. We synthesized evidence narratively. Eight studies from six countries met our eligibility criteria. The overall study quality was low, with diversity in populations, interventions, settings, and methods. Five studies examined the introduction of or increase in user charges for secondary care, with four showing decreased secondary care utilisation, and three showing increased primary care utilisation. One study identified an increase in primary care utilisation after primary care user charges were reduced. The introduction of a non-referral charge in secondary care was associated with lower primary care utilisation in one study. One study compared user charges across insurance plans, associating higher charges in secondary care with higher utilisation in both primary and secondary care. Overall, the impact of introducing differential user-charges on primary care utilisation remains uncertain. Further research is required to understand their impact as a demand side intervention, including implications for health system costs and on utilisation among low-income patients. PMID:28453713
Does charging different user fees for primary and secondary care affect first-contacts with primary healthcare? A systematic review.

PubMed

Hone, Thomas; Lee, John Tayu; Majeed, Azeem; Conteh, Lesong; Millett, Christopher

2017-06-01

Policy-makers are increasingly considering charging users different fees between primary and secondary care (differential user charges) to encourage utilisation of primary health care in health systems with limited gate keeping. A systematic review was conducted to evaluate the impact of introducing differential user charges on service utilisation. We reviewed studies published in MEDLINE, EMBASE, the Cochrane library, EconLIT, HMIC, and WHO library databases from January 1990 until June 2015. We extracted data from the studies meeting defined eligibility criteria and assessed study quality using an established checklist. We synthesized evidence narratively. Eight studies from six countries met our eligibility criteria. The overall study quality was low, with diversity in populations, interventions, settings, and methods. Five studies examined the introduction of or increase in user charges for secondary care, with four showing decreased secondary care utilisation, and three showing increased primary care utilisation. One study identified an increase in primary care utilisation after primary care user charges were reduced. The introduction of a non-referral charge in secondary care was associated with lower primary care utilisation in one study. One study compared user charges across insurance plans, associating higher charges in secondary care with higher utilisation in both primary and secondary care. Overall, the impact of introducing differential user-charges on primary care utilisation remains uncertain. Further research is required to understand their impact as a demand side intervention, including implications for health system costs and on utilisation among low-income patients. © The Author 2017. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Photochromic molecular implementations of universal computation.

PubMed

Chaplin, Jack C; Krasnogor, Natalio; Russell, Noah A

2014-12-01

Unconventional computing is an area of research in which novel materials and paradigms are utilised to implement computation. Previously we have demonstrated how registers, logic gates and logic circuits can be implemented, unconventionally, with a biocompatible molecular switch, NitroBIPS, embedded in a polymer matrix. NitroBIPS and related molecules have been shown elsewhere to be capable of modifying many biological processes in a manner that is dependent on its molecular form. Thus, one possible application of this type of unconventional computing is to embed computational processes into biological systems. Here we expand on our earlier proof-of-principle work and demonstrate that universal computation can be implemented using NitroBIPS. We have previously shown that spatially localised computational elements, including registers and logic gates, can be produced. We explain how parallel registers can be implemented, then demonstrate an application of parallel registers in the form of Turing machine tapes, and demonstrate both parallel registers and logic circuits in the form of elementary cellular automata. The Turing machines and elementary cellular automata utilise the same samples and same hardware to implement their registers, logic gates and logic circuits; and both represent examples of universal computing paradigms. This shows that homogenous photochromic computational devices can be dynamically repurposed without invasive reconfiguration. The result represents an important, necessary step towards demonstrating the general feasibility of interfacial computation embedded in biological systems or other unconventional materials and environments. Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.
Utilisation of rheumatology care services in Germany: the case of physical therapy and self-help groups.

PubMed

Thieme, Holm; Borgetto, Bernhard

2012-01-01

Physical Therapy (PT) and self-help groups (SHG) are important components of health care in rheumatic diseases. The utilisation of PT and SHG by patients with rheumatic diseases may be influenced by several factors. The aim of this study is to summarize the evidence on PT and SHG utilisation of patients with rheumatic diseases in Germany. We systematically searched the MEDLINE-database for studies that evaluated the utilisation and factors that possibly influence the utilisation of PT and SHG. Eight studies were found for PT-utilisation and one for SHG-utilisation. Between 25 and 59 percent of patients with rheumatic diseases received PT services. Several individual and contextual factors that may influence the utilisation could be identified. In conclusion, evidence exists for wide variations in the utilisation of PT services and an underuse of such services among patients with rheumatic diseases in Germany. By contrast, little evidence exists on the utilisation of SHG.
Contemporary engagement with social media amongst hernia surgery specialists.

PubMed

Lui, D H; McDonald, J J; de Beaux, A; Tulloh, B; Brady, R R W

2017-08-01

Healthcare professional engagement is increasing. This study aims to identify levels of adoption and engagement of several social media platforms by a large international cohort of hernia surgery specialists. Hernia specialists attending the 38th International Congress of the European Hernia Society were identified. A manual search was then performed on Twitter, ResearchGate, and LinkedIn to identify those who had named accounts. Where accounts were identified, data on markers of utilisation were assessed. 759 surgeons (88.5% male) from 57 countries were identified. 334 surgeons (44%) engaged with a social media platform. 39 (5.1%) had Twitter accounts, 189 (24.9%) had ResearchGate accounts and 265 (34.9%) had LinkedIn accounts. 137 surgeons (18.1%) had accounts on 2 or more social media platforms. There was no gender association with social media account ownership (p > 0.05). Engagement in one social media platform was associated with increased engagement and utilisation on other platforms; LinkedIn users were more likely to have Twitter accounts (p < 0.001) and ResearchGate profiles (p < 0.001). Surgeons on all three SM platforms were more likely to have high markers of engagement across all SM platforms (multiple outcomes, p < 0.05). Geographical variation was noted with UK and South American Surgeons being more likely to be present on Twitter than their counterparts (p = 0.031). The level of engagement with social media amongst Hernia surgeons is similar to other surgical specialities. Geographical variation in SM engagement is seen. Engagement with one SM platform is associated with presence on multiple platforms.
Improved scatterer property estimates from ultrasound backscatter for small gate lengths using a gate-edge correction factor

NASA Astrophysics Data System (ADS)

Oelze, Michael L.; O'Brien, William D.

2004-11-01

Backscattered rf signals used to construct conventional ultrasound B-mode images contain frequency-dependent information that can be examined through the backscattered power spectrum. The backscattered power spectrum is found by taking the magnitude squared of the Fourier transform of a gated time segment corresponding to a region in the scattering volume. When a time segment is gated, the edges of the gated regions change the frequency content of the backscattered power spectrum due to truncating of the waveform. Tapered windows, like the Hanning window, and longer gate lengths reduce the relative contribution of the gate-edge effects. A new gate-edge correction factor was developed that partially accounted for the edge effects. The gate-edge correction factor gave more accurate estimates of scatterer properties at small gate lengths compared to conventional windowing functions. The gate-edge correction factor gave estimates of scatterer properties within 5% of actual values at very small gate lengths (less than 5 spatial pulse lengths) in both simulations and from measurements on glass-bead phantoms. While the gate-edge correction factor gave higher accuracy of estimates at smaller gate lengths, the precision of estimates was not improved at small gate lengths over conventional windowing functions. .
A multimode electromechanical parametric resonator array

PubMed Central

Mahboob, I.; Mounaix, M.; Nishiguchi, K.; Fujiwara, A.; Yamaguchi, H.

2014-01-01

Electromechanical resonators have emerged as a versatile platform in which detectors with unprecedented sensitivities and quantum mechanics in a macroscopic context can be developed. These schemes invariably utilise a single resonator but increasingly the concept of an array of electromechanical resonators is promising a wealth of new possibilities. In spite of this, experimental realisations of such arrays have remained scarce due to the formidable challenges involved in their fabrication. In a variation to this approach, we identify 75 harmonic vibration modes in a single electromechanical resonator of which 7 can also be parametrically excited. The parametrically resonating modes exhibit vibrations with only 2 oscillation phases which are used to build a binary information array. We exploit this array to execute a mechanical byte memory, a shift-register and a controlled-NOT gate thus vividly illustrating the availability and functionality of an electromechanical resonator array by simply utilising higher order vibration modes. PMID:24658349
Factors that influence utilisation of HIV/AIDS prevention methods among university students residing at a selected university campus.

PubMed

Ndabarora, Eléazar; Mchunu, Gugu

2014-01-01

Various studies have reported that university students, who are mostly young people, rarely use existing HIV/AIDS preventive methods. Although studies have shown that young university students have a high degree of knowledge about HIV/AIDS and HIV modes of transmission, they are still not utilising the existing HIV prevention methods and still engage in risky sexual practices favourable to HIV. Some variables, such as awareness of existing HIV/AIDS prevention methods, have been associated with utilisation of such methods. The study aimed to explore factors that influence use of existing HIV/AIDS prevention methods among university students residing in a selected campus, using the Health Belief Model (HBM) as a theoretical framework. A quantitative research approach and an exploratory-descriptive design were used to describe perceived factors that influence utilisation by university students of HIV/AIDS prevention methods. A total of 335 students completed online and manual questionnaires. Study findings showed that the factors which influenced utilisation of HIV/AIDS prevention methods were mainly determined by awareness of the existing university-based HIV/AIDS prevention strategies. Most utilised prevention methods were voluntary counselling and testing services and free condoms. Perceived susceptibility and perceived threat of HIV/AIDS score was also found to correlate with HIV risk index score. Perceived susceptibility and perceived threat of HIV/AIDS showed correlation with self-efficacy on condoms and their utilisation. Most HBM variables were not predictors of utilisation of HIV/AIDS prevention methods among students. Intervention aiming to improve the utilisation of HIV/AIDS prevention methods among students at the selected university should focus on removing identified barriers, promoting HIV/AIDS prevention services and providing appropriate resources to implement such programmes.
Factors influencing utilisation of maternal health services by adolescent mothers in Low-and middle-income countries: a systematic review.

PubMed

Banke-Thomas, Oluwasola Eniola; Banke-Thomas, Aduragbemi Oluwabusayo; Ameh, Charles Anawo

2017-02-16

Adolescent mothers aged 15-19 years are known to have greater risks of maternal morbidity and mortality compared with women aged 20-24 years, mostly due to their unique biological, sociological and economic status. Nowhere Is the burden of disease greater than in low-and middle-income countries (LMICs). Understanding factors that influence adolescent utilisation of essential maternal health services (MHS) would be critical in improving their outcomes. We systematically reviewed the literature for articles published until December 2015 to understand how adolescent MHS utilisation has been assessed in LMICs and factors affecting service utilisation by adolescent mothers. Following data extraction, we reported on the geographical distribution and characteristics of the included studies and used thematic summaries to summarise our key findings across three key themes: factors affecting MHS utilisation considered by researcher(s), factors assessed as statistically significant, and other findings on MHS utilisation. Our findings show that there has been minimal research in this study area. 14 studies, adjudged as medium to high quality met our inclusion criteria. Studies have been published in many LMICs, with the first published in 2006. Thirteen studies used secondary data for assessment, data which was more than 5 years old at time of analysis. Ten studies included only married adolescent mothers. While factors such as wealth quintile, media exposure and rural/urban residence were commonly adjudged as significant, education of the adolescent mother and her partner were the commonest significant factors that influenced MHS utilisation. Use of antenatal care also predicted use of skilled birth attendance and use of both predicted use of postnatal care. However, there may be some context-specific factors that need to be considered. Our findings strengthen the need to lay emphasis on improving girl child education and removing financial barriers to their access to MHS. Opportunities that have adolescents engaging with health providers also need to be seized. These will be critical in improving adolescent MHS utilisation. However, policy and programmatic choices need to be based on recent, relevant and robust datasets. Innovative approaches that leverage new media to generate context-specific dis-aggregated data may provide a way forward.
Factors affecting Japanese retirees' healthcare service utilisation in Malaysia: a qualitative study

PubMed Central

Kohno, Ayako; Nik Farid, Nik Daliana; Musa, Ghazali; Abdul Aziz, Norlaili; Nakayama, Takeo; Dahlui, Maznah

2016-01-01

Objective While living overseas in another culture, retirees need to adapt to a new environment but often this causes difficulties, particularly among those elderly who require healthcare services. This study examines factors affecting healthcare service utilisation among Japanese retirees in Malaysia. Design We conducted 6 focus group discussions with Japanese retirees and interviewed 8 relevant medical services providers in-depth. Guided by the Andersen Healthcare Utilisation Model, we managed and analysed the data, using QSR NVivo 10 software and the directed content analysis method. Setting We interviewed participants at Japan Clubs and their offices. Participants 30 Japanese retirees who live in Kuala Lumpur and Ipoh, and 8 medical services providers. Results We identified health beliefs, medical symptoms and health insurance as the 3 most important themes, respectively, representing the 3 dimensions within the Andersen Healthcare Utilisation Model. Additionally, language barriers, voluntary health repatriation to Japan and psychological support were unique themes that influence healthcare service utilisation among Japanese retirees. Conclusions The healthcare service utilisation among Japanese retirees in Malaysia could be partially explained by the Andersen Healthcare Utilisation Model, together with some factors that were unique findings to this study. Healthcare service utilisation among Japanese retirees in Malaysia could be improved by alleviating negative health beliefs through awareness programmes for Japanese retirees about the healthcare systems and cultural aspects of medical care in Malaysia. PMID:27006344
Contextual and individual factors associated with dental services utilisation by Brazilian adults: A multilevel analysis

PubMed Central

2018-01-01

Background Inequalities in the utilisation of dental services in Brazil are remarkable. The aim of this study was to evaluate the association of contextual and individual factors with the utilisation of dental services by Brazilian adults using the Andersen’s behavioural model. Methods Individual-level data from 27,017 adults residents in the State capitals who were interviewed in the 2013 Brazilian National Health Survey were pooled with contextual city-level data. The outcomes were non-utilisation of dental services and last dental visit over 12 months ago. Individual predisposing variables were age, sex, race/skin colour, schooling and social network. Individual enabling variables included income, health insurance and registration in primary health care. Individual need variables were self-perceived dental health and self-reported missing teeth. Multilevel logistic regression models were performed to estimate odds ratio (OR) and 95% confidence intervals (95% CIs) of the association of contextual and individual predisposing, enabling and need-related variables with dental services outcomes. Results Predisposing (OR = 0.89; 95% CI 0.81–0.97) and enabling (OR = 0.90; 95% CI 0.85–0.96) contextual factors were associated with non-utilisation of dental services. Individual predisposing (sex, race/skin colour, schooling), enabling (income, health insurance) and need (self-perceived oral health, missing teeth) were associated with non-utilisation of dental services and last dental visit over 12 months ago. The latter was also associated with other individual predisposing (age, social network) and need (eating difficulties due to oral problems) characteristics. Conclusions Individual and contextual determinants influenced dental services utilisation in Brazilian adults. These factors should be on the policy agenda and considered in the organisation of health services aiming to reduce oral health inequalities related to access and utilisation of dental services. PMID:29420660
Contextual and individual factors associated with dental services utilisation by Brazilian adults: A multilevel analysis.

PubMed

Herkrath, Fernando José; Vettore, Mario Vianna; Werneck, Guilherme Loureiro

2018-01-01

Inequalities in the utilisation of dental services in Brazil are remarkable. The aim of this study was to evaluate the association of contextual and individual factors with the utilisation of dental services by Brazilian adults using the Andersen's behavioural model. Individual-level data from 27,017 adults residents in the State capitals who were interviewed in the 2013 Brazilian National Health Survey were pooled with contextual city-level data. The outcomes were non-utilisation of dental services and last dental visit over 12 months ago. Individual predisposing variables were age, sex, race/skin colour, schooling and social network. Individual enabling variables included income, health insurance and registration in primary health care. Individual need variables were self-perceived dental health and self-reported missing teeth. Multilevel logistic regression models were performed to estimate odds ratio (OR) and 95% confidence intervals (95% CIs) of the association of contextual and individual predisposing, enabling and need-related variables with dental services outcomes. Predisposing (OR = 0.89; 95% CI 0.81-0.97) and enabling (OR = 0.90; 95% CI 0.85-0.96) contextual factors were associated with non-utilisation of dental services. Individual predisposing (sex, race/skin colour, schooling), enabling (income, health insurance) and need (self-perceived oral health, missing teeth) were associated with non-utilisation of dental services and last dental visit over 12 months ago. The latter was also associated with other individual predisposing (age, social network) and need (eating difficulties due to oral problems) characteristics. Individual and contextual determinants influenced dental services utilisation in Brazilian adults. These factors should be on the policy agenda and considered in the organisation of health services aiming to reduce oral health inequalities related to access and utilisation of dental services.
Factors affecting Japanese retirees' healthcare service utilisation in Malaysia: a qualitative study.

PubMed

Kohno, Ayako; Nik Farid, Nik Daliana; Musa, Ghazali; Abdul Aziz, Norlaili; Nakayama, Takeo; Dahlui, Maznah

2016-03-22

While living overseas in another culture, retirees need to adapt to a new environment but often this causes difficulties, particularly among those elderly who require healthcare services. This study examines factors affecting healthcare service utilisation among Japanese retirees in Malaysia. We conducted 6 focus group discussions with Japanese retirees and interviewed 8 relevant medical services providers in-depth. Guided by the Andersen Healthcare Utilisation Model, we managed and analysed the data, using QSR NVivo 10 software and the directed content analysis method. We interviewed participants at Japan Clubs and their offices. 30 Japanese retirees who live in Kuala Lumpur and Ipoh, and 8 medical services providers. We identified health beliefs, medical symptoms and health insurance as the 3 most important themes, respectively, representing the 3 dimensions within the Andersen Healthcare Utilisation Model. Additionally, language barriers, voluntary health repatriation to Japan and psychological support were unique themes that influence healthcare service utilisation among Japanese retirees. The healthcare service utilisation among Japanese retirees in Malaysia could be partially explained by the Andersen Healthcare Utilisation Model, together with some factors that were unique findings to this study. Healthcare service utilisation among Japanese retirees in Malaysia could be improved by alleviating negative health beliefs through awareness programmes for Japanese retirees about the healthcare systems and cultural aspects of medical care in Malaysia. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
The role of non-need factors in individual GP utilisation analysis and their implications for the pursuance of equity: a cross-country comparison.

PubMed

McGregor, P; McKee, P; O'Neill, C

2008-05-01

A substantial amount of health care resources is allocated within the UK using formulae that relate funding to measures of population need. The aim of this paper is to demonstrate the importance of non-need factors in determining utilisation of services at an individual level and explore the implications inclusion of such factors has in the consideration of equity. In the paper we develop a utility model that accords a role to non-health factors in the determination of service use. A series of functions incorporating non-health factors as explanatory variables in GP utilisation functions are estimated using data from the British Household Panel Survey. The functions are decomposed to ascertain the role of service structure and examine the role of income across the four countries of the UK in explaining utilisation. The implications of our findings for the pursuance of equity in the NHS when individual choice has an explicit role are discussed.
Factors associated with postnatal care utilisation in Rwanda: A secondary analysis of 2010 Demographic and Health Survey data.

PubMed

Rwabufigiri, Bernard N; Mukamurigo, Judith; Thomson, Dana R; Hedt-Gautier, Bethany L; Semasaka, Jean Paul S

2016-05-31

Postnatal care (PNC) in the first seven days is important for preventing morbidity and mortality in mothers and new-borns. Sub-Saharan African countries, which account for 62 % of maternal deaths globally, have made major efforts to increase PNC utilisation, but utilisation rates remains low even in countries like Rwanda where PNC services are universally available for free. This study identifies key socio-economic and demographic factors associated with PNC utilisation in Rwanda to inform improved PNC policies and programs. This is a secondary analysis of the 2010 Demographic and Health Survey, a national multi-stage, cross-sectional survey. In bivariate analysis, we used chi-square tests to identify demographic and socio-economic factors associated with PNC utilisation at α = 0.1. Pearson's R statistic (r > 0.5) was used to identify collinear covariates, and to choose which covariate was more strongly associated with PNC utilisation. Manual backward stepwise logistic regression was performed on the remaining covariates to identify key factors associated with PNC utilisation at α = 0.05. All analyses were performed in Stata 13 adjusting for sampling weights, clustering, and stratification. Of the 2,748 women with a live birth in the last two years who answered question about PNC utilisation, 353 (12.8 %) returned for PNC services within seven days after birth. Three factors were positively associated with PNC use: delivering at a health facility (OR: 2.97; 95 % CI: 2.28-3.87), being married but not involved with one's own health care decision-making (OR: 1.69; 95 % CI: 1.17, 2.44) compared to being married and involved; and being in the second (OR: 1.46; 95 % CI: 1.01-2.09) or richest wealth quintile (OR: 2.04; 95 % CI: 1.27-3.29) compared to the poorest. Mother's older age at delivery was negatively associated with PNC use (20-29 - OR: 0.51, 95 % CI: 0.29-0.87; 30-39 - OR: 0.47, 95 % CI: 0.27-0.83; 40-49 - OR: 0.32, 95 % CI: 0.16-0.64). Low PNC utilisation in Rwanda appears to be a universal problem though older age and poverty are further barriers to PNC utilisation. A recent change in the provision of BCG vaccination to new-borns might promote widespread PNC utilisation. We further recommend targeted campaigns to older mothers and poorest mothers, focusing on perceptions of health system quality, cultural beliefs, and pregnancy risks.
What is access to radiation therapy? A conceptual framework and review of influencing factors.

PubMed

Sundaresan, Puma; Stockler, Martin R; Milross, Christopher G

2016-02-01

Optimal radiation therapy (RT) utilisation rates (RURs) have been defined for various cancer indications through extensive work in Australia and overseas. These benchmarks remain unrealised. The gap between optimal RUR and actual RUR has been attributed to inadequacies in 'RT access'. We aimed to develop a conceptual framework for the consideration of 'RT access' by examining the literature for existing constructs and translating it to the context of RT services. We further aimed to use this framework to identify and examine factors influencing 'RT access'. Existing models of health care access were reviewed and used to develop a multi-dimensional conceptual framework for 'RT access'. A review of the literature was then conducted to identify factors reported to affect RT access and utilisation. The electronic databases searched, the host platform and date range of the databases searched were Ovid MEDLINE, 1946 to October 2014 and PsycINFO via OvidSP,1806 to October 2014. The framework developed demonstrates that 'RT access' encompasses opportunity for RT as well as the translation of this opportunity to RT utilisation. Opportunity for RT includes availability, affordability, adequacy (quality) and acceptability of RT services. Several factors at the consumer, referrer and RT service levels affect the translation of this opportunity for RT to actual RT utilisation. 'Access' is a term that is widely used in the context of health service related research, planning and political discussions. It is a multi-faceted concept with many descriptions. We propose a conceptual framework for the consideration of 'RT access' so that factors affecting RT access and utilisation may be identified and examined. Understanding these factors, and quantifying them where possible, will allow objective evaluation of their impact on RT utilisation and guide implementation of strategies to modify their effects.

Utilisation of cancer screening services by disabled women in Chile

PubMed Central

Rotarou, Elena S.

2017-01-01

Background Research has shown that women with disabilities face additional challenges in accessing and using healthcare services compared to non-disabled women. However, relatively little is known about the utilisation of cancer screening services for women with disabilities. This study addresses this gap by examining the utilisation of the Papanicolaou test and mammography for disabled women in Chile. Methods We used cross-sectional data, taken from a 2015 nationally-representative survey. Initially, we employed logistic regressions to test for differences in utilisation rates for the Papanicolaou test (66,281 observations) and the mammogram (35,294 observations) between disabled and non-disabled women. Next, logistic regressions were used to investigate the demographic, socioeconomic, and health-related factors affecting utilisation rates for cancer screening services for disabled women (sample sizes: 5,823 observations for the Papanicolaou test and 5,731 observations for the mammogram). Results Disabled women were less likely to undergo screening tests than non-disabled women. For the Papanicolaou test and mammography, the multivariable regression models showed that living in rural areas, having higher education, being affiliated with a private health insurance company, giving a good health self-assessment score, and being under medical treatment for other illnesses were associated with higher utilisation rates. On the other hand, being single, inactive with regard to employment, and having a better income were linked with lower utilisation. While utilisation rates for both disabled and non-disabled women have increased since 2006, the utilisation disparity has slightly increased. Conclusions This study shows the influence of various factors in the utilisation rates of preventive cancer screening services for disabled women. To develop effective initiatives targeting inequalities in the utilisation of cancer screening tests, it is important to move beyond an exclusively single-disease approach and acknowledge the complexity of the patient population. PMID:28459874
Utilisation of cancer screening services by disabled women in Chile.

PubMed

Sakellariou, Dikaios; Rotarou, Elena S

2017-01-01

Research has shown that women with disabilities face additional challenges in accessing and using healthcare services compared to non-disabled women. However, relatively little is known about the utilisation of cancer screening services for women with disabilities. This study addresses this gap by examining the utilisation of the Papanicolaou test and mammography for disabled women in Chile. We used cross-sectional data, taken from a 2015 nationally-representative survey. Initially, we employed logistic regressions to test for differences in utilisation rates for the Papanicolaou test (66,281 observations) and the mammogram (35,294 observations) between disabled and non-disabled women. Next, logistic regressions were used to investigate the demographic, socioeconomic, and health-related factors affecting utilisation rates for cancer screening services for disabled women (sample sizes: 5,823 observations for the Papanicolaou test and 5,731 observations for the mammogram). Disabled women were less likely to undergo screening tests than non-disabled women. For the Papanicolaou test and mammography, the multivariable regression models showed that living in rural areas, having higher education, being affiliated with a private health insurance company, giving a good health self-assessment score, and being under medical treatment for other illnesses were associated with higher utilisation rates. On the other hand, being single, inactive with regard to employment, and having a better income were linked with lower utilisation. While utilisation rates for both disabled and non-disabled women have increased since 2006, the utilisation disparity has slightly increased. This study shows the influence of various factors in the utilisation rates of preventive cancer screening services for disabled women. To develop effective initiatives targeting inequalities in the utilisation of cancer screening tests, it is important to move beyond an exclusively single-disease approach and acknowledge the complexity of the patient population.
Enhanced and continuous electrostatic carrier doping on the SrTiO3 surface

PubMed Central

Eyvazov, A. B.; Inoue, I. H.; Stoliar, P.; Rozenberg, M. J.; Panagopoulos, C.

2013-01-01

Paraelectrical tuning of a charge carrier density as high as 1013 cm−2 in the presence of a high electronic carrier mobility on the delicate surfaces of correlated oxides, is a key to the technological breakthrough of a field effect transistor (FET) utilising the metal-nonmetal transition. Here we introduce the Parylene-C/Ta2O5 hybrid gate insulator and fabricate FET devices on single-crystalline SrTiO3, which has been regarded as a bedrock material for oxide electronics. The gate insulator accumulates up to ~1013cm−2 carriers, while the field-effect mobility is kept at 10 cm2/Vs even at room temperature. Further to the exceptional performance of our devices, the enhanced compatibility of high carrier density and high mobility revealed the mechanism for the long standing puzzle of the distribution of electrostatically doped carriers on the surface of SrTiO3. Namely, the formation and continuous evolution of field domains and current filaments.
Factors influencing resident's decision to reside in gated and guarded community

NASA Astrophysics Data System (ADS)

Shamsudin, Zarina; Shamsudin, Shafiza; Zainal, Rozlin

2017-10-01

Gated communities are residential areas developed with restricted access with strictly controlled entrances and surrounded by a close perimeter of wall or fences. Developers, conscious of the need to fulfill the requirement of living in modern and sophisticated lifestyle and gated properties become the trend and mushroomed over the past decade. Nowadays, it is obvious that gated and guarded communities become almost a dominant feature of Malaysia housing development projects. The focus of this paper is to identify the factors contribute resident's decision to reside in gated and guarded community and to study social interaction among gated communities' residents. 150 questionnaires were distributed to the residents of selected gated and guarded community area in order to achieve the objectives and analyzed by using Statistical Package for Social Science (SPSS) and descriptive analysis. The result was tabulated and presented in charts and graphs for a clear and better understanding. The five main factors contribute to resident decision to reside in gated communities were identified and ranked; there are privacy, security, location, lifestyle and prestige. Besides, the residents are feeling neutral towards the facilities and services provided in their gated and guarded residential area. A comprehensive improvement towards the facilities and services is needed to reach higher satisfaction from the residents.
Ethnic Factors in Mental Health Service Utilisation among People with Intellectual Disability in High-Income Countries: Systematic Review

ERIC Educational Resources Information Center

Dura-Vila, G.; Hodes, M.

2012-01-01

Background: An emerging literature suggests that ethnic and cultural factors influence service utilisation among people with intellectual disability (ID), but this has not previously been reviewed. Aims: To investigate possible ethnic variation in uptake of mental health services in children, adolescents and adults with ID in high-income…
Assessing psychosocial correlates of parental safety behaviour using Protection Motivation Theory: stair gate presence and use among parents of toddlers.

PubMed

Beirens, T M J; Brug, J; van Beeck, E F; Dekker, R; den Hertog, P; Raat, H

2008-08-01

Unintentional injury due to falls is one of the main reasons for hospitalization among children 0-4 years of age. The goal of this study was to assess the psychosocial correlates of parental safety behaviours to prevent falls from a staircase due to the lack of or the lack of adequate use of a stair gate. Data were collected from a cross-sectional survey using self-administered questionnaires mailed to a population sample of 2470 parents with toddlers. Associations between self-reported habits on the presence and use of stair gates and family and psychosocial factors were analysed, using descriptive statistics and multiple regression models, based on Protection Motivation Theory. The presence of stair gates was associated with family situation, perceived vulnerability, response efficacy, social norms and descriptive norms. The use of stair gates was associated with family situation, response efficacy, self-efficacy and perceived advantages of safe behaviour. The full model explained 32 and 24% of the variance in the presence of stair gates and the use of stair gates, respectively, indicating a large and medium effect size. Programmes promoting the presence and adequate use of stair gates should address the family situation, personal cognitive factors as well as social factors.
Assessing psychosocial correlates of parental safety behaviour using Protection Motivation Theory: stair gate presence and use among parents of toddlers

PubMed Central

Beirens, T. M. J.; Brug, J.; van Beeck, E. F.; Dekker, R.; den Hertog, P.; Raat, H.

2008-01-01

Unintentional injury due to falls is one of the main reasons for hospitalization among children 0–4 years of age. The goal of this study was to assess the psychosocial correlates of parental safety behaviours to prevent falls from a staircase due to the lack of or the lack of adequate use of a stair gate. Data were collected from a cross-sectional survey using self-administered questionnaires mailed to a population sample of 2470 parents with toddlers. Associations between self-reported habits on the presence and use of stair gates and family and psychosocial factors were analysed, using descriptive statistics and multiple regression models, based on Protection Motivation Theory. The presence of stair gates was associated with family situation, perceived vulnerability, response efficacy, social norms and descriptive norms. The use of stair gates was associated with family situation, response efficacy, self-efficacy and perceived advantages of safe behaviour. The full model explained 32 and 24% of the variance in the presence of stair gates and the use of stair gates, respectively, indicating a large and medium effect size. Programmes promoting the presence and adequate use of stair gates should address the family situation, personal cognitive factors as well as social factors. PMID:17947245
Health services utilisation disparities between English speaking and non-English speaking background Australian infants

PubMed Central

2010-01-01

Background To examine the differences in health services utilisation and the associated risk factors between infants from non-English speaking background (NESB) and English speaking background (ESB) within Australia. Methods We analysed data from a national representative longitudinal study, the Longitudinal Study of Australian Children (LSAC) which started in 2004. We used survey logistic regression coupled with survey multiple linear regression to examine the factors associated with health services utilisation. Results Similar health status was observed between the two groups. In comparison to ESB infants, NESB infants were significantly less likely to use the following health services: maternal and child health centres or help lines (odds ratio [OR] 0.56; 95% confidence intervals [CI], 0.40-0.79); maternal and child health nurse visits (OR 0.68; 95% CI, 0.49-0.95); general practitioners (GPs) (OR 0.58; 95% CI, 0.40-0.83); and hospital outpatient clinics (OR 0.54; 95% CI, 0.31-0.93). Multivariate analysis results showed that the disparities could not be fully explained by the socioeconomic status and language barriers. The association between English proficiency and the service utilised was absent once the NESB was taken into account. Maternal characteristics, family size and income, private health insurance and region of residence were the key factors associated with health services utilisation. Conclusions NESB infants accessed significantly less of the four most frequently used health services compared with ESB infants. Maternal characteristics and family socioeconomic status were linked to health services utilisation. The gaps in health services utilisation between NESB and ESB infants with regard to the use of maternal and child health centres or phone help, maternal and child health nurse visits, GPs and paediatricians require appropriate policy attentions and interventions. PMID:20374663
SUPPRESSION OF AFTERPULSING IN PHOTOMULTIPLIERS BY GATING THE PHOTOCATHODE

EPA Science Inventory

A number of gating schemes to minimize the long-term afterpulse signal in photomultipliers have been evaluated. Blocking the excitation pulse by gating the photocathode was found to reduce the gate-on afterpulse background by a factor of 230 over that for nongated operation. Thi...
Determination of the predictive factors of long-lasting insecticide-treated net ownership and utilisation in the Bamenda Health District of Cameroon.

PubMed

Fokam, Eric B; Kindzeka, Germaine F; Ngimuh, Leonard; Dzi, Kevin T J; Wanji, Samuel

2017-03-16

Malaria is a serious health concern in Africa. In Cameroon, an endemic country where malaria remains a major public health problem, several control measures have been put in place among which the use of insecticide-treated bednets (LLINs/ITNs) is considered one of the core vector control strategies. However, the greatest challenges include ownership and utilisation by individuals and households. Factors such as age, marital status, gender, education and occupation of the household head, household size, knowledge of bednets, socioeconomic status, and environmental factors have been suggested to have an impact on bednet ownership and utilisation in different settings. The present study sought to determine bednet ownership and utilisation rates and to assess the impact of predictive factors on bednet ownership and use in the Bamenda Health District (BHD) of Cameroon. A cross-sectional study involving 384 households was conducted in six health areas in the BHD. A structured and semi-structured questionnaire was used to collect data on demographic and household characteristics as well as information on their bednet ownership and utilisation. Descriptive statistics, bivariate and multivariate logistic regression analysis were performed. Frequency of bednet ownership was relatively high (63.5%) with LLINs being most abundant (91.9%); the majority of households (87.7%) obtained their bednets during the 2011 free distribution campaign. Utilisation was relatively high (69.3%), with negligence (29.3%) and heat discomfort (26.7%) accounting most for non-usage of bednets. Children less than 5 years (63%) and pregnant women (60%) most often used these nets. Households headed by a married couple, those with older household heads, household with smaller size (5-12 persons), and knowledge of bednets (good knowledge) had positive impacts on bednet ownership (p < 0.05). The gender of the household head (males), their educational level, environmental conditions (presence of suitable mosquito breeding sites), bednet number in households (greater number of bednets) and the prioritised groups (children < 5 and pregnant women) had positive impacts on bednet utilisation in households (p < 0.05). There was a negative association between bednet ownership and utilisation by households as bednet ownership was high and utilisation of these nets was low. Marital status and age of household head, household size, and knowledge of bednets had impacts on bednet ownership while gender and educational level of the household head, environmental suitability, the number of bednets and the two prioritised groups had an impact on bednet usage. These factors may be relevant for policy makers and in decision making for the intensification of campaign strategies to ensure more effective subsequent distribution campaigns in the BHD and beyond.
Depth profiling of calcifications in breast tissue using picosecond Kerr-gated Raman spectroscopy.

PubMed

Baker, Rebecca; Matousek, Pavel; Ronayne, Kate Louise; Parker, Anthony William; Rogers, Keith; Stone, Nicholas

2007-01-01

Breast calcifications are found in both benign and malignant lesions and their composition can indicate the disease state. Calcium oxalate (dihydrate) (COD) is associated with benign lesions, however calcium hydroxyapatite (HAP) is found mainly in proliferative lesions including carcinoma. The diagnostic practices of mammography and histopathology examine the morphology of the specimen. They can not reliably distinguish between the two types of calcification, which may indicate the presence of a cancerous lesion during mammography. We demonstrate for the first time that Kerr-gated Raman spectroscopy is capable of non-destructive probing of sufficient biochemical information from calcifications buried within tissue, and this information can potentially be used as a first step in identifying the type of lesion. The method uses a picosecond pulsed laser combined with fast temporal gating of Raman scattered light to enable spectra to be collected from a specific depth within scattering media by collecting signals emerging from the sample at a given time delay following the laser pulse. Spectra characteristic of both HAP and COD were obtained at depths of up to 0.96 mm, in both chicken breast and fatty tissue; and normal and cancerous human breast by utilising different time delays. This presents great potential for the use of Raman spectroscopy as an adjunct to mammography in the early diagnosis of breast cancer.
Univariate and multivariate spatial models of health facility utilisation for childhood fevers in an area on the coast of Kenya.

PubMed

Ouma, Paul O; Agutu, Nathan O; Snow, Robert W; Noor, Abdisalan M

2017-09-18

Precise quantification of health service utilisation is important for the estimation of disease burden and allocation of health resources. Current approaches to mapping health facility utilisation rely on spatial accessibility alone as the predictor. However, other spatially varying social, demographic and economic factors may affect the use of health services. The exclusion of these factors can lead to the inaccurate estimation of health facility utilisation. Here, we compare the accuracy of a univariate spatial model, developed only from estimated travel time, to a multivariate model that also includes relevant social, demographic and economic factors. A theoretical surface of travel time to the nearest public health facility was developed. These were assigned to each child reported to have had fever in the Kenya demographic and health survey of 2014 (KDHS 2014). The relationship of child treatment seeking for fever with travel time, household and individual factors from the KDHS2014 were determined using multilevel mixed modelling. Bayesian information criterion (BIC) and likelihood ratio test (LRT) tests were carried out to measure how selected factors improve parsimony and goodness of fit of the time model. Using the mixed model, a univariate spatial model of health facility utilisation was fitted using travel time as the predictor. The mixed model was also used to compute a multivariate spatial model of utilisation, using travel time and modelled surfaces of selected household and individual factors as predictors. The univariate and multivariate spatial models were then compared using the receiver operating area under the curve (AUC) and a percent correct prediction (PCP) test. The best fitting multivariate model had travel time, household wealth index and number of children in household as the predictors. These factors reduced BIC of the time model from 4008 to 2959, a change which was confirmed by the LRT test. Although there was a high correlation of the two modelled probability surfaces (Adj R 2 = 88%), the multivariate model had better AUC compared to the univariate model; 0.83 versus 0.73 and PCP 0.61 versus 0.45 values. Our study shows that a model that uses travel time, as well as household and individual-level socio-demographic factors, results in a more accurate estimation of use of health facilities for the treatment of childhood fever, compared to one that relies on only travel time.
Soliton all-optical logic AND gate with semiconductor optical amplifier-assisted Mach-Zehnder interferometer

NASA Astrophysics Data System (ADS)

Kotb, Amer; Zoiros, Kyriakos E.

2016-08-01

The concept of soliton provides a line in research in telecommunications systems. In the present study, a soliton all-optical logic AND gate with semiconductor optical amplifier (SOA)-assisted Mach-Zehnder interferometer has been numerically simulated and investigated. The dependence of the output quality factor (Q-factor) on the soliton characteristics and SOA parameters has been examined and assessed. The obtained results demonstrate that the soliton AND gate is capable of operating at a data rate of 80 Gb/s with logical correctness and high-output Q-factor.
Modeling of High-Quality Factor XNOR Gate Using Quantum-Dot Semiconductor Optical Amplifiers at 1 Tb/s

NASA Astrophysics Data System (ADS)

Kotb, Amer

2015-06-01

The modeling of all-optical logic XNOR gate is realized by a series combination of XOR and INVERT gates. This Boolean function is simulated by using Mach-Zehnder interferometers (MZIs) utilizing quantum-dots semiconductor optical amplifiers (QDs-SOAs). The study is carried out when the effect of amplified spontaneous emission (ASE) is included. The dependence of the output quality factor ( Q-factor) on signals and QDs-SOAs' parameters is also investigated and discussed. The simulation is conducted under a repetition rate of ˜1 Tb/s.
Delayed LGI1 seropositivity in voltage-gated potassium channel (VGKC)-complex antibody limbic encephalitis

PubMed Central

Sweeney, Michael; Galli, Jonathan; McNally, Scott; Tebo, Anne; Haven, Thomas; Thulin, Perla; Clardy, Stacey L

2017-01-01

We utilise a clinical case to highlight why exclusion of voltage-gated potassium channel (VGKC)-complex autoantibody testing in serological evaluation of patients may delay or miss the diagnosis. A 68-year-old man presented with increasing involuntary movements consistent with faciobrachial dystonic seizures (FBDS). Initial evaluation demonstrated VGKC antibody seropositivity with leucine-rich glioma-inactivated 1 (LGI1) and contactin-associated protein-like 2 (CASPR2) seronegativity. Aggressive immunotherapy with methylprednisolone and plasmapheresis was started early in the course of his presentation. Following treatment with immunotherapy, the patient demonstrated clinical improvement. Repeat serum evaluation 4 months posthospitalisation remained seropositive for VGKC-complex antibodies, with development of LGI1 autoantibody seropositivity. VGKC-complex and LGI1 antibodies remained positive 12 months posthospitalisation. Our findings suggest that clinical symptoms can predate the detection of the antibody. We conclude that when suspicion for autoimmune encephalitis is high in the setting of VGKC autoantibody positivity, regardless of LGI1 or CASPR2 seropositivity, early immunotherapy and repeat testing should be considered. PMID:28432047
Delayed LGI1 seropositivity in voltage-gated potassium channel (VGKC)-complex antibody limbic encephalitis.

PubMed

Sweeney, Michael; Galli, Jonathan; McNally, Scott; Tebo, Anne; Haven, Thomas; Thulin, Perla; Clardy, Stacey L

2017-04-20

We utilise a clinical case to highlight why exclusion of voltage-gated potassium channel (VGKC)-complex autoantibody testing in serological evaluation of patients may delay or miss the diagnosis. A 68-year-old man presented with increasing involuntary movements consistent with faciobrachial dystonic seizures (FBDS). Initial evaluation demonstrated VGKC antibody seropositivity with leucine-rich glioma-inactivated 1 (LGI1) and contactin-associated protein-like 2 (CASPR2) seronegativity. Aggressive immunotherapy with methylprednisolone and plasmapheresis was started early in the course of his presentation. Following treatment with immunotherapy, the patient demonstrated clinical improvement. Repeat serum evaluation 4 months posthospitalisation remained seropositive for VGKC-complex antibodies, with development of LGI1 autoantibody seropositivity. VGKC-complex and LGI1 antibodies remained positive 12 months posthospitalisation. Our findings suggest that clinical symptoms can predate the detection of the antibody. We conclude that when suspicion for autoimmune encephalitis is high in the setting of VGKC autoantibody positivity, regardless of LGI1 or CASPR2 seropositivity, early immunotherapy and repeat testing should be considered. 2017 BMJ Publishing Group Ltd.
Utilisation of health services and the poor: deconstructing wealth-based differences in facility-based delivery in the Philippines.

PubMed

Hodge, Andrew; Firth, Sonja; Bermejo, Raoul; Zeck, Willibald; Jimenez-Soto, Eliana

2016-07-06

Despite achieving some success, wealth-related disparities in the utilisation of maternal and child health services persist in the Philippines. The aim of this study is to decompose the principal factors driving the wealth-based utilisation gap. Using national representative data from the 2013 Philippines Demographic and Health Survey, we examine the extent overall differences in the utilisation of maternal health services can be explained by observable factors. We apply nonlinear Blinder-Oaxaca-type decomposition methods to quantify the effect of differences in measurable characteristics on the wealth-based coverage gap in facility-based delivery. The mean coverage of facility-based deliveries was respectively 41.1 % and 74.6 % for poor and non-poor households. Between 67 and 69 % of the wealth-based coverage gap was explained by differences in observed characteristics. After controlling for factors characterising the socioeconomic status of the household (i.e. the mothers' and her partners' education and occupation), the birth order of the child was the major factor contributing to the disparity. Mothers' religion and the subjective distance to the health facility were also noteworthy. This study has found moderate wealth-based disparities in the utilisation of institutional delivery in the Philippines. The results confirm the importance of recent efforts made by the Philippine government to implement equitable, pro-poor focused health programs in the most deprived geographic areas of the country. The importance of addressing the social determinants of health, particularly education, as well as developing and implementing effective strategies to encourage institutional delivery for higher order births, should be prioritised.
Determinants of skilled birth attendants for delivery in Nepal.

PubMed

Baral, Y R; Lyons, K; Skinner, J; van Teijlingen, E R

2010-01-01

This review is to explore the factors affecting the uptake of skilled birth attendants for delivery and the issues associated with women's role and choices of maternal health care service for delivery in Nepal. Literature was reviewed across the globe and discussed in a Nepalese context. Delivery by Skilled Birth Attendance serves as an indicator of progress towards reducing maternal mortality worldwide, the fifth Millennium Development Goal. Nepal has committed to reducing its maternal mortality by 75% by 2015 through ensuring accessibility to the availability and utilisation of skilled care at every birth. The literature suggests that several socio-economic, cultural and religious factors play a significant role in the use of Skilled Birth Attendance for delivery in Nepal. Availability of transportation and distance to the health facility; poor infrastructure and lack of services; availability and accessibility of the services; cost and convenience; staff shortages and attitudes; gender inequality; status of women in society; women's involvement in decision making; and women's autonomy and place of residence are significant contributing factors for uptake of Skilled Birth Attendance for delivery in Nepal. The review found more quantitative research studies exploring the determinants of utilisation of the maternal health services during pregnancy in Nepal than qualitative studies. Findings of quantitative research show that different social demographic, economic, socio-cultural and religious factors are responsible for the utilisation of maternal health services but very few studies discussed how and why these factors are responsible for utilisation of skilled birth attendants in pregnancy. It is suggested that there is need for more qualitative research to explore the women's role and choice regarding use of skilled birth attendants services and to find out how and why these factors are responsible for utilisation of skilled birth attendants for delivery. Qualitative research will help further exploration of the issues and contribute to improvement of maternal health services.
The Impact of Gate Width Setting and Gate Utilization Factors on Plutonium Assay in Passive Correlated Neutron Counting

DOE PAGES

Henzlova, Daniela; Menlove, Howard Olsen; Croft, Stephen; ...

2015-06-15

In the field of nuclear safeguards, passive neutron multiplicity counting (PNMC) is a method typically employed in non-destructive assay (NDA) of special nuclear material (SNM) for nonproliferation, verification and accountability purposes. PNMC is generally performed using a well-type thermal neutron counter and relies on the detection of correlated pairs or higher order multiplets of neutrons emitted by an assayed item. To assay SNM, a set of parameters for a given well-counter is required to link the measured multiplicity rates to the assayed item properties. Detection efficiency, die-away time, gate utilization factors (tightly connected to die-away time) as well as optimummore » gate width setting are among the key parameters. These parameters along with the underlying model assumptions directly affect the accuracy of the SNM assay. In this paper we examine the role of gate utilization factors and the single exponential die-away time assumption and their impact on the measurements for a range of plutonium materials. In addition, we examine the importance of item-optimized coincidence gate width setting as opposed to using a universal gate width value. Finally, the traditional PNMC based on multiplicity shift register electronics is extended to Feynman-type analysis and application of this approach to Pu mass assay is demonstrated.« less
Impact of the macroeconomic factors on university budgeting the US and Russia

NASA Astrophysics Data System (ADS)

Bogomolova, Arina; Balk, Igor; Ivachenko, Natalya; Temkin, Anatoly

2017-10-01

This paper discuses impact of macroeconomics factor on the university budgeting. Modern developments in the area of data science and machine learning made it possible to utilise automated techniques to address several problems of humankind ranging from genetic engineering and particle physics to sociology and economics. This paper is the first step to create a robust toolkit which will help universities sustain macroeconomic challenges utilising modern predictive analytics techniques.

Experimental Study of the Detection Limit in Dual-Gate Biosensors Using Ultrathin Silicon Transistors.

PubMed

Wu, Ting; Alharbi, Abdullah; You, Kai-Dyi; Kisslinger, Kim; Stach, Eric A; Shahrjerdi, Davood

2017-07-25

Dual-gate field-effect biosensors (bioFETs) with asymmetric gate capacitances were shown to surpass the Nernst limit of 59 mV/pH. However, previous studies have conflicting findings on the effect of the capacitive amplification scheme on the sensor detection limit, which is inversely proportional to the signal-to-noise ratio (SNR). Here, we present a systematic experimental investigation of the SNR using ultrathin silicon transistors. Our sensors operate at low voltage and feature asymmetric front and back oxide capacitances with asymmetry factors of 1.4 and 2.3. We demonstrate that in the dual-gate configuration, the response of our bioFETs to the pH change increases proportional to the asymmetry factor and indeed exceeds the Nernst limit. Further, our results reveal that the noise amplitude also increases in proportion to the asymmetry factor. We establish that the commensurate increase of the noise amplitude originates from the intrinsic low-frequency characteristic of the sensor noise, dominated by number fluctuation. These findings suggest that this capacitive signal amplification scheme does not improve the intrinsic detection limit of the dual-gate biosensors.
Gated strip proportional detector

DOEpatents

Morris, C.L.; Idzorek, G.C.; Atencio, L.G.

1985-02-19

A gated strip proportional detector includes a gas tight chamber which encloses a solid ground plane, a wire anode plane, a wire gating plane, and a multiconductor cathode plane. The anode plane amplifies the amount of charge deposited in the chamber by a factor of up to 10/sup 6/. The gating plane allows only charge within a narrow strip to reach the cathode. The cathode plane collects the charge allowed to pass through the gating plane on a set of conductors perpendicular to the open-gated region. By scanning the open-gated region across the chamber and reading out the charge collected on the cathode conductors after a suitable integration time for each location of the gate, a two-dimensional image of the intensity of the ionizing radiation incident on the detector can be made.
Gated strip proportional detector

DOEpatents

Morris, Christopher L.; Idzorek, George C.; Atencio, Leroy G.

1987-01-01

A gated strip proportional detector includes a gas tight chamber which encloses a solid ground plane, a wire anode plane, a wire gating plane, and a multiconductor cathode plane. The anode plane amplifies the amount of charge deposited in the chamber by a factor of up to 10.sup.6. The gating plane allows only charge within a narrow strip to reach the cathode. The cathode plane collects the charge allowed to pass through the gating plane on a set of conductors perpendicular to the open-gated region. By scanning the open-gated region across the chamber and reading out the charge collected on the cathode conductors after a suitable integration time for each location of the gate, a two-dimensional image of the intensity of the ionizing radiation incident on the detector can be made.
Transformation of socio-cultural aspect of gated housing’s residence in Medan City, Indonesia.

NASA Astrophysics Data System (ADS)

Nirfalini Aulia, Dwira

2018-03-01

Gated Community Housing develops rapidly in Medan City and other big cities in Indonesia. These housing types initially reserved for middle to high-income residents. Transformation can describe as changes from one condition to another condition that can happen continuously in time. Change is affected by internal and external factors. Internal factors include culture, perspective, and social system while external factors include science progress and other cultural influence. This research is a descriptive study which tries to describe the phenomenon that is currently ongoing. Gated housing chosen are Perumahan Taman Setia Budi Indah, Perumahan Bumi Asri dan Perumahan Graha Helvetia. Characteristics of gated housing’s residents transform by the regional or national socioeconomic transformation. The structure and function of human social life are not uniform; meaning in every social life setting each of the structure and function are different. The characteristic of a community will transform in continuity.
78 FR 55093 - Dog Management Plan, Supplemental Environmental Impact Statement, Golden Gate National Recreation...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-09

....YP0000] Dog Management Plan, Supplemental Environmental Impact Statement, Golden Gate National Recreation... the Dog Management Plan (Plan/SEIS), Golden Gate National Recreation Area (GGNRA), California. Current dog management in the park is based on a number of factors. Areas included in the GGNRA Citizens...
SU-E-J-159: Analysis of Total Imaging Uncertainty in Respiratory-Gated Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suzuki, J; Okuda, T; Sakaino, S

Purpose: In respiratory-gated radiotherapy, the gating phase during treatment delivery needs to coincide with the corresponding phase determined during the treatment plan. However, because radiotherapy is performed based on the image obtained for the treatment plan, the time delay, motion artifact, volume effect, and resolution in the images are uncertain. Thus, imaging uncertainty is the most basic factor that affects the localization accuracy. Therefore, these uncertainties should be analyzed. This study aims to analyze the total imaging uncertainty in respiratory-gated radiotherapy. Methods: Two factors of imaging uncertainties related to respiratory-gated radiotherapy were analyzed. First, CT image was used to determinemore » the target volume and 4D treatment planning for the Varian Realtime Position Management (RPM) system. Second, an X-ray image was acquired for image-guided radiotherapy (IGRT) for the BrainLAB ExacTrac system. These factors were measured using a respiratory gating phantom. The conditions applied during phantom operation were as follows: respiratory wave form, sine curve; respiratory cycle, 4 s; phantom target motion amplitude, 10, 20, and 29 mm (which is maximum phantom longitudinal motion). The target and cylindrical marker implanted in the phantom coverage of the CT images was measured and compared with the theoretically calculated coverage from the phantom motion. The theoretical position of the cylindrical marker implanted in the phantom was compared with that acquired from the X-ray image. The total imaging uncertainty was analyzed from these two factors. Results: In the CT image, the uncertainty between the target and cylindrical marker’s actual coverage and the coverage of CT images was 1.19 mm and 2.50mm, respectively. In the Xray image, the uncertainty was 0.39 mm. The total imaging uncertainty from the two factors was 1.62mm. Conclusion: The total imaging uncertainty in respiratory-gated radiotherapy was clinically acceptable. However, an internal margin should be added to account for the total imaging uncertainty.« less
Low use of contraceptives among rural women in Maitha, Uttar Pradesh, India.

PubMed

Saroha, Ekta; Altarac, Maja; Sibley, Lynn M

2013-05-01

Low contraceptive utilisation and high fertility in rural Uttar Pradesh (UP), India, is a major concern for the world's second most populous country. The association between reasons for low contraceptive utilisation and maternal factors has been inadequately researched. Data from the 'morbidity and performance assessment' study were analysed to explore reasons for low contraceptive utilisation and their association with maternal factors among 308 women in Maitha, rural UP, India. Chi-square, t-test, ANOVA, and logistic regression analyses were conducted. Majority (84.2%) of the rural women in Maitha, UP, India were not using any contraceptives. Upper caste, literate wives, and wives whose husbands were literate were more likely to use contraceptives. About one-third of the women did not want to use a contraceptive because they wanted another child. Large numbers (65.3%) of women wanted to use contraceptives but were unable to do so due to lack of knowledge (38.9%), fear of side-effects (15.5%), husband/family disapproval (15.5%), inconvenience (10.7%), and other reasons (19.1%). Maternal parity, wives' and husband's literacy were significantly associated with the reasons for low contraceptive utilisation (p < 0.05). Contraceptive utilisation can be Improved by taking into consideration such maternal characteristics. All state subsidised contraceptives should be more widely known, understood and made available.
Entry one: striving for best practice in professional assessment.

PubMed

English, Justin M; Mykyta, Lu

2002-01-01

The aim of this study was to develop a best practice model of professional assessment to ensure efficient and effective delivery of home-based services to frail and disabled elders. In 2000, an innovative model of professional assessment was introduced by one of Australia's largest providers of home-based care in order to reduce multiple assessments and to reduce the utilisation of assessment as a gatekeeping tool for limiting access to services. Data was analysed from a random sample of 1500 clients drawn from a population of 5000 as well as through the use of a survey tool administered to the Organisation's assessment staff and other key stakeholders. Results revealed that, contrary to popular belief, carer advocacy plays a significant role in the professional assessment process to the point that clients with carers received significantly more services and service time that clients without such support. However, if not monitored, assessment can also be used as a gate-keeping tool as opposed to one that can provide significant benefits to the consumers through comprehensive need articulation. We argue that the "professional" approach does not preclude empowerment and that assessment should not be used as a gate-keeping tool.
Sociodemographic and health behavioural factors associated with access to and utilisation of eye care in Korea: Korea Health and Nutrition Examination Survey 2008–2012

PubMed Central

Rim, Tyler Hyungtaek; Choi, Moonjung; Yoon, Jin Sook; Kim, Sung Soo

2015-01-01

Objective To determine the sociodemographic and health behavioural factors associated with access to and utilisation of eye care in Korea. Design Nationwide cross-sectional study Methods 25 752 Koreans over the age of 30 were assessed from a national representative survey. We analysed independent variables of self-reporting eye clinic visits through multivariable analyses of sociodemographic factors. The time since the last visit to an eye clinic was used to assess access to and utilisation of eye care. Results Of the 25 752 respondents, 8237 (32.0%) visited an eye clinic in the past year, 11 028 (42.8%) were seen more than 1 year ago, while 6487 (25.2%) had never seen an ophthalmologist. Eye clinic utilisation was statistically associated with older age, female sex, higher household income, higher education levels, living in an urban area, and having comorbidities including diabetes and hypertension. Middle-aged men between 30 and 49 years were found to be less likely to receive eye care compared to the rest of the population, and the proportion that did plummeted after the financial crisis of 2007. Conclusions There is a substantial sociodemographic disparity in eye care utilisation in Korea, and men with low financial income and education level are especially at risk. Use of eye care among middle-aged men has decreased since the global financial crisis that began in 2007, and therefore healthcare policies and public interventions should be targeted at vulnerable groups to promote access to medical care. PMID:26185177
[Psychometric Testing of a New Scale Assessing the Reasons for Non-Utilisation of Health Care Services by People with Migration Backgrounds].

PubMed

Maier, I; Kriston, L; Härter, M; Hölzel, L P; Bermejo, I

2015-10-01

In Germany live a lot of migrants. Cultural and migration specific aspects seem to have an effect on utilisation of health care. There are no instruments that measure such factors of influence. A systematic literature research or article that identify the difficulties of the migrants in using the health care system, was made. The relevant aspects were explored during a health related opinion survey of migrants from former USSR, Turkey, Italy and Spain. The psychometric qualities of this questionnaire were investigated with factor and reliability analyses. There were 24 reasons identified for non-utilisation health care. They were combined in a questionnaire. The factor analysis showed 2-factor structure ("janguage und information related Reasons" Chronbach's α=0.928 and "experience with/attitude toward health care system", Chronbach's α=0.879). Furthermore, there was a total scale with Chronbach's α=0.945. The acceptance was between 80.0 and 96.3%. The results confirm the psychometric quality of this measuring instrument. For further generalisability more verification will be necessary. © Georg Thieme Verlag KG Stuttgart · New York.
Maternal health services utilisation by Kenyan adolescent mothers: Analysis of the Demographic Health Survey 2014.

PubMed

Banke-Thomas, Aduragbemi; Banke-Thomas, Oluwasola; Kivuvani, Mwikali; Ameh, Charles Anawo

2017-06-01

Kenya has one of the highest adolescent fertility rates in East-Africa, estimated at 106 births per 1000 females aged 15-19years. In addition to promoting safe sexual behaviour, utilisation of maternal health services (MHS) is essential to prevent poor outcomes of pregnancy and childbirth. To ensure optimum planning, particularly in the context of the Sustainable Development Goals, this study assesses the current service utilisation patterns of Kenyan adolescent mothers and the factors that affect this utilisation. Using data from the recently published 2014 Kenya Demographic Health Survey, we collected demographic and utilisation data of all three MHSs (antenatal care (ANC), skilled birth attendance (SBA) and postnatal care (PNC)) of adolescent mothers aged 15-19years. We then conducted bivariate and multivariate analyses to test associations between selected demographic and service utilisation variables. Our findings showed that half of Kenyan adolescent mothers have had their first birth by the age of 16. MHS utilisation rates amongst Kenyan adolescent mothers were 93%, 65%, 92% for ANC, SBA and PNC respectively. Mother's education, religion, ethnicity, place of residence, wealth quintile, mass media exposure, and geographical region were significant predictors for both ANC and SBA utilisation. Education level of partner was significant for ANC utilisation while parity was significant for both SBA and PNC. Adolescent MHS utilisation is not optimum in Kenya. More work that includes affordable care provision, cultural re-orientation, targeted mass-media campaigns and male involvement in care need to be done with emphasis on the most disadvantaged areas. Copyright © 2017 Elsevier B.V. All rights reserved.
Dental health-care service utilisation and its determinants in West Iran: a cross-sectional study.

PubMed

Rezaei, Satar; Woldemichael, Abraha; Zandian, Hamed; Homaie Rad, Enayatollah; Veisi, Navid; Karami Matin, Behzad

2018-06-01

Dental health care is not only an effective strategy for the prevention, early diagnosis and treatment of oral diseases but also contributes to the general health of communities. This study aimed to investigate the situation of dental health-care service utilisation and its determinants in Kermanshah city, western Iran, in 2015. A cross-sectional study on a total of 894 household heads was conducted. The participants were selected using a multistage sampling technique. A self-administered questionnaire was used to collect the data. Multiple logistic regression was performed to assess factors associated with utilisation of dental-care services and a negative binomial regression was carried out to identify the main factor associated with the frequency of visiting a dentist for dental health care. A statistically significant association was considered at a value of P < 0.05. All the analyses were performed using STATA version 12. Of the total household heads who participated in the study, 60.3% and 9.9% reported visiting a dentist for dental treatment in the past year and for 6-monthly dental check-ups, respectively. The average ± standard deviation number of visits by a respondent was 2.08 ± 2.97. Of the total number of respondents, 281 (31.4%) reported visiting a dentist once or twice in the last 12 months for dental health-care services, while 28.9% reported visiting a dentist more than twice in the same time period. Ageing, having dental insurance, higher income, being a university graduate, self-rated poor oral health and not regularly brushing own teeth were the main factors associated with utilisation of dental health-care services. Our study indicates that dental health-care utilisation among households in the study area was influenced by a number of factors, including being socio-economically disadvantaged, self-rated poor oral health and not regularly brushing own teeth. Therefore, in this setting, dental-intervention programmes, including dental health insurance, should focus on mechanisms that can strengthen utilisation of preventive dental health-care services among disadvantaged households. © 2017 FDI World Dental Federation.
RNA polymerase gate loop guides the nontemplate DNA strand in transcription complexes.

PubMed

NandyMazumdar, Monali; Nedialkov, Yuri; Svetlov, Dmitri; Sevostyanova, Anastasia; Belogurov, Georgiy A; Artsimovitch, Irina

2016-12-27

Upon RNA polymerase (RNAP) binding to a promoter, the σ factor initiates DNA strand separation and captures the melted nontemplate DNA, whereas the core enzyme establishes interactions with the duplex DNA in front of the active site that stabilize initiation complexes and persist throughout elongation. Among many core RNAP elements that participate in these interactions, the β' clamp domain plays the most prominent role. In this work, we investigate the role of the β gate loop, a conserved and essential structural element that lies across the DNA channel from the clamp, in transcription regulation. The gate loop was proposed to control DNA loading during initiation and to interact with NusG-like proteins to lock RNAP in a closed, processive state during elongation. We show that the removal of the gate loop has large effects on promoter complexes, trapping an unstable intermediate in which the RNAP contacts with the nontemplate strand discriminator region and the downstream duplex DNA are not yet fully established. We find that although RNAP lacking the gate loop displays moderate defects in pausing, transcript cleavage, and termination, it is fully responsive to the transcription elongation factor NusG. Together with the structural data, our results support a model in which the gate loop, acting in concert with initiation or elongation factors, guides the nontemplate DNA in transcription complexes, thereby modulating their regulatory properties.
Experimental Study of the Detection Limit in Dual-Gate Biosensors Using Ultrathin Silicon Transistors

DOE PAGES

Wu, Ting; Alharbi, Abdullah; You, Kai-Dyi; ...

2017-06-21

Dual-gate field-effect biosensors (bioFETs) with asymmetric gate capacitances were shown to surpass the Nernst limit of 59 mV/pH. However, previous studies have conflicting findings on the effect of the capacitive amplification scheme on the sensor detection limit, which is inversely proportional to the signal-to-noise ratio (SNR). In this paper, we present a systematic experimental investigation of the SNR using ultrathin silicon transistors. Our sensors operate at low voltage and feature asymmetric front and back oxide capacitances with asymmetry factors of 1.4 and 2.3. We demonstrate that in the dual-gate configuration, the response of our bioFETs to the pH change increasesmore » proportional to the asymmetry factor and indeed exceeds the Nernst limit. Further, our results reveal that the noise amplitude also increases in proportion to the asymmetry factor. We establish that the commensurate increase of the noise amplitude originates from the intrinsic low-frequency characteristic of the sensor noise, dominated by number fluctuation. Finally, these findings suggest that this capacitive signal amplification scheme does not improve the intrinsic detection limit of the dual-gate biosensors.« less
Experimental Study of the Detection Limit in Dual-Gate Biosensors Using Ultrathin Silicon Transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Ting; Alharbi, Abdullah; You, Kai-Dyi

Dual-gate field-effect biosensors (bioFETs) with asymmetric gate capacitances were shown to surpass the Nernst limit of 59 mV/pH. However, previous studies have conflicting findings on the effect of the capacitive amplification scheme on the sensor detection limit, which is inversely proportional to the signal-to-noise ratio (SNR). In this paper, we present a systematic experimental investigation of the SNR using ultrathin silicon transistors. Our sensors operate at low voltage and feature asymmetric front and back oxide capacitances with asymmetry factors of 1.4 and 2.3. We demonstrate that in the dual-gate configuration, the response of our bioFETs to the pH change increasesmore » proportional to the asymmetry factor and indeed exceeds the Nernst limit. Further, our results reveal that the noise amplitude also increases in proportion to the asymmetry factor. We establish that the commensurate increase of the noise amplitude originates from the intrinsic low-frequency characteristic of the sensor noise, dominated by number fluctuation. Finally, these findings suggest that this capacitive signal amplification scheme does not improve the intrinsic detection limit of the dual-gate biosensors.« less
Migrant female head porters' enrolment in and utilisation and renewal of the National Health Insurance Scheme in Kumasi, Ghana.

PubMed

Boateng, Simon; Amoako, Prince; Poku, Adjoa Afriyie; Baabereyir, Anthony; Gyasi, Razak Mohammed

2017-01-01

As a social protection policy, Ghana's National Health Insurance Scheme (NHIS) aims to improve access to healthcare, especially for the vulnerable. Migrant female head porters ( kayayoo ), who are part of the informal economic workforce, are underscored as an ethnic minority and vulnerable group in Ghana. This study aimed to analyse the factors associated with enrolment in and renewal and utilisation of the NHIS among migrant female head porters in the Kumasi Metropolis. We purposively sampled 392 migrant female head porters in the Kejetia, Asafo and Bantama markets. We used a binary logit regression model to estimate associations among baseline characteristics, convenience and benefit factors and enrolment in and renewal and utilisation of the NHIS. Age and income significantly increased the probability of NHIS enrolment, renewal and utilisation. Long waiting times at NHIS offices significantly reduced the likelihood of renewal, while provision of drugs highly significantly increased the tendency for migrant female head porters to enrol in, renew and use the NHIS. Consulting and surgery also significantly increased renewal and utilisation of the NHIS. Political commitment is imperative for effective implementation of the decentralisation policy of the NHIS through the National Health Insurance Authority in Kumasi. We argue that retail offices should be well equipped with logistic facilities to ensure convenience in NHIS initial enrolment and renewal processes by citizenry, and by vulnerable groups in particular.
Understanding Teachers' Perspectives of Factors That Influence Parental Involvement Practices in Special Education in Barbados

ERIC Educational Resources Information Center

Blackman, Stacey; Mahon, Erin

2016-01-01

Parental involvement has been defined in various ways by researchers and is reported to have many advantages for children's education. The research utilises a case study strategy to investigate teachers' perspectives of parental involvement at four case sites in Barbados. In-depth interviews were done with teachers and analysis utilised content…
Impediments to Effective Utilisation of Information and Communication Technology Tools in Selected Universities in the North-Eastern Nigeria

ERIC Educational Resources Information Center

Momoh, Mustapha

2010-01-01

This study examined the impediments to effective use of Information and Communication Technology (ICT) tools in Nigerian universities. Series of research conducted on the factors militating against computerisation indicated that, there were impediments to effective utilisation of ICT tools in most developing countries. In the light of this, the…
Sociodemographic and health behavioural factors associated with access to and utilisation of eye care in Korea: Korea Health and Nutrition Examination Survey 2008-2012.

PubMed

Rim, Tyler Hyungtaek; Choi, Moonjung; Yoon, Jin Sook; Kim, Sung Soo

2015-07-16

To determine the sociodemographic and health behavioural factors associated with access to and utilisation of eye care in Korea. Nationwide cross-sectional study 25,752 Koreans over the age of 30 were assessed from a national representative survey. We analysed independent variables of self-reporting eye clinic visits through multivariable analyses of sociodemographic factors. The time since the last visit to an eye clinic was used to assess access to and utilisation of eye care. Of the 25,752 respondents, 8237 (32.0%) visited an eye clinic in the past year, 11 028 (42.8%) were seen more than 1 year ago, while 6487 (25.2%) had never seen an ophthalmologist. Eye clinic utilisation was statistically associated with older age, female sex, higher household income, higher education levels, living in an urban area, and having comorbidities including diabetes and hypertension. Middle-aged men between 30 and 49 years were found to be less likely to receive eye care compared to the rest of the population, and the proportion that did plummeted after the financial crisis of 2007. There is a substantial sociodemographic disparity in eye care utilisation in Korea, and men with low financial income and education level are especially at risk. Use of eye care among middle-aged men has decreased since the global financial crisis that began in 2007, and therefore healthcare policies and public interventions should be targeted at vulnerable groups to promote access to medical care. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
The utilisation of health research in policy-making: concepts, examples and methods of assessment

PubMed Central

Hanney, Stephen R; Gonzalez-Block, Miguel A; Buxton, Martin J; Kogan, Maurice

2003-01-01

The importance of health research utilisation in policy-making, and of understanding the mechanisms involved, is increasingly recognised. Recent reports calling for more resources to improve health in developing countries, and global pressures for accountability, draw greater attention to research-informed policy-making. Key utilisation issues have been described for at least twenty years, but the growing focus on health research systems creates additional dimensions. The utilisation of health research in policy-making should contribute to policies that may eventually lead to desired outcomes, including health gains. In this article, exploration of these issues is combined with a review of various forms of policy-making. When this is linked to analysis of different types of health research, it assists in building a comprehensive account of the diverse meanings of research utilisation. Previous studies report methods and conceptual frameworks that have been applied, if with varying degrees of success, to record utilisation in policy-making. These studies reveal various examples of research impact within a general picture of underutilisation. Factors potentially enhancing utilisation can be identified by exploration of: priority setting; activities of the health research system at the interface between research and policy-making; and the role of the recipients, or 'receptors', of health research. An interfaces and receptors model provides a framework for analysis. Recommendations about possible methods for assessing health research utilisation follow identification of the purposes of such assessments. Our conclusion is that research utilisation can be better understood, and enhanced, by developing assessment methods informed by conceptual analysis and review of previous studies. PMID:12646071

Oral-health-related background factors and dental service utilisation among Sudanese children with and without a congenital heart defects.

PubMed

Ali, H M; Mustafa, M; Nasir, E F; Lie, S A; Hasabalrasol, S; Elshazali, O H; Ali, R W; Skeie, M S

2016-11-15

Sudanese children with congenital heart defects (CHDs) were found to have poorer oral health than those without CHDs. The aims of this study were to: describe the patterns of oral-health-related background factors in children with and without CHD and explore any differences, and to evaluate the effects of background factors on caries and gingivitis prevalence and dental services utilisation. In this analytical cross-sectional study, caregivers of children aged 3-12 years with (CHD cases n = 111) and without CHDs (Controls n = 182), underwent face-to-face interviews using a structured questionnaire. The questionnaire items covered several oral health background factors (independent variables) including: child's health status, oral hygiene practices, dental services utilization, mother's level of education, and caregiver's perception and awareness of their child's oral health. The relationship between these factors and occurrence of 'caries' and 'gingivitis' as well as 'child's dental services utilisation' (dependent variables) were explored using multiple adjusted and hierarchal logistic regression analyses. Compared with controls, CHD cases had lower frequencies of brushing and use of fluoridated toothpaste, and their caregivers were less knowledgeable about caries. Among CHD cases, the variables (brushing and fluoridated toothpaste use) had significant impacts on caries prevalence (odd ratio (OR) =5.6, 95% confidence interval (CI): 1.4-22.8 and OR = 0.3, 95% CI: 0.1-0.8 for infrequent compared to frequent ones, respectively) as well as the mother's level of education (OR = 2.6, 95% CI: 1.0-6.4). When differences in background factors were controlled for, the adjusted ORs for caries and gingivitis prevalence in CHD cases compared with controls were 1.8, (95% CI: 1.1-3.2) and 5.3 (95% CI: 2.9-9.4), respectively. Among CHD cases, the child's age (8-12 years: OR = 11.9, 95% CI: 1.9-71.6), and the mother's level of education (lower education: OR = 0.2, 95% CI: 0.03-0.9) were significantly associated with the child's dental services utilisation. Lower frequencies of brushing and use of fluoride tooth paste were reported among CHD cases, and brushing had the predominant significant impact on caries prevalence. The child's age and the mother's level of education were the main factors affecting the child's (CHD cases) dental services utilisation.
Utilisation of hepatocellular carcinoma screening in Australians at risk of hepatitis B virus-related carcinoma and prescribed anti-viral therapy.

PubMed

Sheppard-Law, Suzanne; Zablotska-Manos, Iryna; Kermeen, Melissa; Holdaway, Susan; Lee, Alice; George, Jacob; Zekry, Amany; Maher, Lisa

2018-07-01

To investigate hepatocellular carcinoma screening utilisation and factors associated with utilisation among patients prescribed hepatitis B virus anti-viral therapy and at risk of hepatocellular carcinoma. The incidence of hepatocellular carcinoma has increased in Australia over the past three decades with chronic hepatitis B virus infection a major contributor. hepatocellular carcinoma surveillance programs aim to detect cancers early enabling curative treatment options, longer survival and longer times to recurrence. Multi-site cross-sectional survey. An online study questionnaire was administered to eligible participants attending three Sydney tertiary hospitals. Data were grouped into six mutually exclusive hepatocellular carcinoma risk factor categories as per American Association for the Study of Liver Diseases guidelines. All analyses were undertaken in STATA. Logistic regression was used to assess the associations between covariates and screening utilisation. Multivariate models described were assessed using the Hosmer-Lemeshow goodness of fit. Of the 177 participants, 137 (77.4%) self-reported that US had been performed in the last six months. Awareness that screening should be performed and knowing the correct frequency of US screening were independently associated with screening utilisation. Participants who knew that screening should be undertaken were three times more likely to have had pretreatment education or were prescribed hepatitis B virus anti-viral treatment for >4 years. Participants reporting a family history of hepatocellular carcinoma were less likely to know that screening should be undertaken every 6 months. While utilisation of hepatocellular carcinoma surveillance programs was higher in this study than in previous reports, strategies to further improve surveillance remain necessary. Findings from this research form the basis for proposing strategies to improve utilisation of hepatocellular carcinoma screening, inform hepatitis B virus-related clinical practice and for the delivery of care and nursing education to people receiving hepatitis B virus anti-viral therapy and at risk of developing hepatocellular carcinoma. © 2018 John Wiley & Sons Ltd.
Cost and utilisation of healthcare resources during rehabilitation after ankle fracture are not linked to health insurance, income, gender, or pain: an observational study.

PubMed

Lin, Chung-Wei Christine; Haas, Marion; Moseley, Anne M; Herbert, Robert D; Refshauge, Kathryn M

2008-01-01

What are the costs and utilisation of healthcare resources, their determinants, and quality of life for people attending outpatient physiotherapy after ankle fracture? Longitudinal observational study. Ninety-four adults (2 dropouts) following cast removal after isolated ankle fracture attending outpatient physiotherapy at three hospitals in Sydney, Australia. Costs incurred (direct healthcare costs and out-of-pocket costs) and utilisation of healthcare system resources were measured at 4, 8, 12, 16, 20, and 24 weeks. Quality of life was measured shortly after cast removal and at 4, 12, and 24 weeks. Factors known to influence costs and utilisation in other conditions (private health insurance, income level, gender, and pain) were also measured. The total cost per person was AUD 735 (SD 876) over 24 weeks. Outpatient physiotherapy accounted for the highest costs in both direct healthcare (39%) and out-of-pocket (42%) costs. Less than 20% of participants sought private non-medical care in addition to receiving outpatient physiotherapy. None of the factors investigated had a significant influence on costs and utilisation. Quality of life score improved over the 24 weeks by a mean of 6.1 points out of 45 (95% CI 5.2 to 6.9), with most of the improvement occurring in the domain of independent living. Information on costs and utilisation of healthcare resources can be used to plan health services, eg, the number of physiotherapy sessions required after ankle fracture. Private health insurance, income level, gender, or pain did not influence the costs or the decision behind seeking care over and above publicly-provided physiotherapy.
NOTE: Implementation of angular response function modeling in SPECT simulations with GATE

NASA Astrophysics Data System (ADS)

Descourt, P.; Carlier, T.; Du, Y.; Song, X.; Buvat, I.; Frey, E. C.; Bardies, M.; Tsui, B. M. W.; Visvikis, D.

2010-05-01

Among Monte Carlo simulation codes in medical imaging, the GATE simulation platform is widely used today given its flexibility and accuracy, despite long run times, which in SPECT simulations are mostly spent in tracking photons through the collimators. In this work, a tabulated model of the collimator/detector response was implemented within the GATE framework to significantly reduce the simulation times in SPECT. This implementation uses the angular response function (ARF) model. The performance of the implemented ARF approach has been compared to standard SPECT GATE simulations in terms of the ARF tables' accuracy, overall SPECT system performance and run times. Considering the simulation of the Siemens Symbia T SPECT system using high-energy collimators, differences of less than 1% were measured between the ARF-based and the standard GATE-based simulations, while considering the same noise level in the projections, acceleration factors of up to 180 were obtained when simulating a planar 364 keV source seen with the same SPECT system. The ARF-based and the standard GATE simulation results also agreed very well when considering a four-head SPECT simulation of a realistic Jaszczak phantom filled with iodine-131, with a resulting acceleration factor of 100. In conclusion, the implementation of an ARF-based model of collimator/detector response for SPECT simulations within GATE significantly reduces the simulation run times without compromising accuracy.
Gender differences in substrate utilisation during exercise.

PubMed

Ruby, B C; Robergs, R A

1994-06-01

The selection and utilisation of metabolic substrates during endurance exercise are regulated by a complex array of effectors. These factors include, but are not limited to, endurance training and cardiorespiratory fitness, exercise intensity and duration, muscle morphology and histology, hormonal factors and diet. Although the effects of these factors on substrate utilisation patterns are well understood, the variation in substrate utilisation during endurance exercise between males and females is not. Because of the extreme heterogeneity in exercise protocols and individuals studied, the differences in substrate utilisation between males and females remain somewhat inconclusive. Regardless of heterogeneity, if the results from studies are interpreted collectively, an apparent gender difference in the selection and metabolism of substrates can be seen in sedentary individuals. However, this difference between genders diminishes as the level of cardiorespiratory fitness is increased to that of highly trained individuals. During rest and lower intensity exercise, the preferential metabolism of lipid occurs with a concomitant sparing of muscle glycogen. However, as the intensity of exercise is increased, the relative contribution of carbohydrate also increases. The exercise intensity at which the shift from lipid to carbohydrate is determined and regulated by the previously mentioned factors. Because the intensity and duration of exercise play a predominant role, the variation in exercise protocols poses a methodological concern when interpreting previous research. When attempting to compare the metabolism of substrates during endurance exercise, appropriate selection and interpretation of measurement techniques are necessary. Measurement techniques include the nonprotein respiratory exchange ratio, muscle and fat biopsies and the measurement of various blood metabolites, such as free fatty acids and glycerol. Similarly, in vitro analysis of lipolytic activity has also been demonstrated in males and females in response to varying levels of female gonadotrophic hormones. When comparing the substrate utilisation patterns between males and females, the area of hormonal regulation has received less attention. Often the catecholamine response to endurance exercise is measured; however, the gonadotrophic hormones, particularly those of the female, have received less attention when comparing genders. Indeed, the regulatory nature of the female gonadotrophic hormones has been demonstrated. Collectively, the effects of elevated estrogen, as in the luteal phase of menstruation, appear to promote lipolytic activity. Estrogen-mediated lipolytic activation occurs by apparently altering the sensitivity to lipoprotein lipase and by increasing the levels of human growth hormone (somatotropin), an activator of lipolysis.(ABSTRACT TRUNCATED AT 400 WORDS)
What are the determinants of food security among regional and remote Western Australian children?

PubMed

Godrich, Stephanie L; Davies, Christina R; Darby, Jill; Devine, Amanda

2017-01-22

To explore how determinants of food security affect children in regional and remote Western Australia (WA), across food availability, access and utilisation dimensions. The Determinants of Food Security framework guided the thematic analysis (using NVivo 10) of semi-structured interviews with 20 key informants. Food availability factors included availability, price, promotion, quality, location of outlets and variety. Food access factors included social support, financial resources, transport to food outlets, distance to food outlets and mobility. Food utilisation factors included nutrition knowledge and skills, children's food preferences, storage facilities, preparation and cooking facilities and time to purchase food. Key food availability recommendations include increasing local food supply options. Food access recommendations include ensuring equitable formal social support and empowering informal support options. Food utilisation recommendations include prioritising food literacy programs focusing on quick, healthy food preparation and budgeting skills. Implications for public health: Policymakers should invest in local food supply options, equitable social support services and experiential food literacy programs. Practitioners should focus child/parent programs on improving attitude, knowledge and skills. © 2017 Public Health Association of Australia.
Nutrient utilisation and particulate organic matter changes during summer in the upper mixed layer (Ross Sea, Antarctica)

NASA Astrophysics Data System (ADS)

Catalano, G.; Povero, P.; Fabiano, M.; Benedetti, F.; Goffart, A.

1997-01-01

The relationships among vertical stability, estimated nutrient utilisation and particulate organic matter in the Ross Sea are analysed from data collected during two cruises in the summers of 1987-1988 and 1989-1990. In the upper mixed layer (UML), identified through the vertical stability E( Z(UML)), nutrient consumption is calculated as the difference between the "diluted" nutrient value and the mean calculated from the integrated value in the UML. The nutrient utilisation ratio and E( Z(UML)) are linearly related for E( Z(UML))≤25, whereas for values > 25, the distribution pattern is more scattered and independent of E( Z(UML)). For E( Z(UML))≥25, utilisation values were ≥4, 0.4 and 10 mmol m -3 for nitrate, phosphate and silicate, respectively. Significant relationships between nutrient depletion and both particulate organic carbon (POC) and particulate protein/particulate carbohydrate ratios (PPRT/PCHO) are found. The analysis of particulate matter distribution vs nutrient utilisation shows that the stations could be divided into two groups having different characteristics. The first group includes coastal stations, where high nutrient utilisation, POC and PPRT/PCHO are typical of areas with high production. In the second group (pelagic stations), nutrient utilisation, POC and PPRT/PCHO are lower. The vertical stability can be used to discriminate among the factors that influence primary production.
Social determinants of dental health services utilisation of Greek adults.

PubMed

Pavi, E; Karampli, E; Zavras, D; Dardavesis, T; Kyriopoulos, J

2010-09-01

To identify the determinants of dental care utilisation among Greek adults, with a particular emphasis on socio-economic determinants. Data were collected through a national survey on health and health care services utilisation of a sample of 4,003 Greek adults stratified by geographic region, age and gender. A purpose made questionnaire was used during face-to-face interviews. A 2-stage model was developed to assess the impact of independent variables on dental utilisation likelihood and frequency. 39.6% (1,562) of Greek adults reported having visited a dentist within the last year. Among dental attenders, 32.6% reported prevention as the reason for visit. Statistically significant differences in dental care utilisation were observed in relation to demographic, socioeconomic and lifestyle factors. Logistic regression analysis showed that gender, age, income, education, place of residence, private insurance coverage and self-rated oral health are important determinants of dental services utilisation. Mean number of dental visits within previous year was 1.6. Results from Poisson regression analysis indicated that lower income level correlates to lower number of dental visits, while having visited for treatment (rather than for prevention) correlated to higher number of dental visits. Greek adults do not exhibit satisfactory dental visiting behaviour. Extent of care sought is associated with need for treatment rather than preventive reasons. The findings confirm the existence of socioeconomic inequalities in dental services utilisation among Greek adults.
Evaluation of the effect of gate strategies in drayage related emissions.

DOT National Transportation Integrated Search

2013-03-01

Intermodal Marine Container Terminals are experiencing growth in container volumes and are under pressure to : develop strategies to accommodate increasing demand. One of the major factors contributing to the problem is : inefficient gate operations ...
Skills Utilisation at Work, the Quality of the Study Programme and Fields of Study

ERIC Educational Resources Information Center

Støren, Liv Anne; Arnesen, Clara Åse

2016-01-01

This paper examines the factors that may have impact on the extent to which the knowledge and skills of master's degree graduates in Norway are utilised at work, three years after graduation. The focus is on the impact of the quality of the study programme as well as the graduates' fields of study, when also taking into account other factors…
Development of a framework to improve the utilisation of malaria research for policy development in Malawi.

PubMed

Mwendera, Chikondi; de Jager, Christiaan; Longwe, Herbert; Hongoro, Charles; Phiri, Kamija; Mutero, Clifford M

2017-11-21

The existing gap between research evidence and public health practice has attributed to the unmet Millennium Development Goals in Africa and consequently, has stimulated the development of frameworks to enhance knowledge translation. These efforts aim at maximising health research utilisation in policy and practice to address the world's disease burdens, including malaria. This study aimed at developing a contextual framework to improve the utilisation of malaria research for policy development in Malawi. The study used two approaches including: two case studies of policy analysis exploring the policy-making process in Malawi, utilisation of local malaria research, and the role of key stakeholders in policy formulation process; and the assessment of facilitating factors and barriers to malaria research utilisation for policy-making in Malawi. From the case studies' lessons and elements identified during the assessment of facilitating factors and barriers, a framework is developed to promote an integrated approach to knowledge translation. In this framework the Ministry of Health is considered as the main user of knowledge from research through the demand created by the research directorate and the National Malaria Control Programme. Key documents identified as being particularly relevant to the Ministry of Health for purposes of knowledge translation include the National Health Research Agenda, Guidelines for Policy Development and Analysis, and Guidelines for Evidence Use in Policy-making. Institutions conducting academic and policy-relevant malaria research in Malawi are identified and a consolidation of their linkages with the users of research is established through the Knowledge Translation Unit, the Evidence Informed decision-making Centre, and the African Institute for Development Policy. Equally, key players in this framework are the funding partners for both research and programmes that need to see accountability and impact of their support. Independent advisors, partners, and consultants also have their vital role in the process. The framework offers a practical basis for the factors identified and their linkages to promote a co-ordinated approach to malaria research utilisation in policy-making. Its applicability and success hinges on its wider dissemination and ownership by the government through the National Malaria Control Programme.
Risk and protective factors for falls on stairs in young children: multicentre case–control study

PubMed Central

Kendrick, D; Zou, K; Ablewhite, J; Watson, M; Coupland, C; Kay, B; Hawkins, A; Reading, R

2016-01-01

Aim To investigate risk and protective factors for stair falls in children aged <5 years. Methods Multicentre case–control study at hospitals, minor injury units and general practices in and around four UK study centres. Cases were children with medically attended stair fall injuries. Controls were matched on age, sex, calendar time and study centre. A total of 610 cases and 2658 controls participated. Results Cases’ most common injuries were bangs on the head (66%), cuts/grazes not requiring stitches (14%) and fractures (12%). Parents of cases were significantly more likely not to have stair gates (adjusted OR (AOR) 2.50, 95% CI 1.90 to 3.29; population attributable fraction (PAF) 21%) or to leave stair gates open (AOR 3.09, 95% CI 2.39 to 4.00; PAF 24%) both compared with having closed stair gates. They were more likely not to have carpeted stairs (AOR 1.52, 95% CI 1.09 to 2.10; PAF 5%) and not to have a landing part-way up their stairs (AOR 1.34, 95% CI 1.08 to 1.65; PAF 18%). They were more likely to consider their stairs unsafe to use (AOR 1.46, 95% CI 1.07 to 1.99; PAF 5%) or to be in need of repair (AOR 1.71, 95% CI 1.16 to 2.50; PAF 5%). Conclusion Structural factors including having landings part-way up the stairs and keeping stairs in good repair were associated with reduced stair fall injury risk. Family factors including having stair gates, not leaving gates open and having stair carpets were associated with reduced injury risk. If these associations are causal, addressing these factors in housing policy and routine child health promotion could reduce stair fall injuries. PMID:26662926
Calibration of region-specific gates equation for LRFD.

DOT National Transportation Integrated Search

2014-02-01

The objectives of this research are to recalibrate the FHWA-modi ed Gates equation : and update the associated LRFD resistance factor for pile types and local soil conditions : encountered in Louisiana. This research is consistent with FHWA recomm...
Gate-violation behavior at highway-rail grade crossings and the consequences: Using geo-Spatial modeling integrated with path analysis.

PubMed

Liu, Jun; Khattak, Asad J

2017-12-01

Drivers undertaking risky behaviors at highway-rail grade crossings are often severely injured in collisions with trains. Among these behaviors, gate-violation (referring to driving around or through the gates that were activated and lowered by an approaching train) seems to be one of the most dangerous actions a driver might take at a gated crossing; it may compromise the intended safety improvement made by adding gates at crossings. This study develops a nuanced conceptual framework that uses path analysis to explore the contributing factors to gate-violation behaviors and the correlation between gate-violation behaviors and the crash consequence - the driver injury severity. Further, using geo-spatial modeling techniques, this study explores whether the correlates of gate-violation behaviors and their associations with injury severity are stationary across diverse geographic contexts of the United States. Geo-spatial modeling shows that the correlates of gate-violation and its associations with injury severity vary substantially across the United States. Spatial variations in correlates of gate-violation and injury severity are mapped by estimating geographically weighted regressions; the maps can serve as an instrument for screening safety improvements and help identify regions that need safety improvements. For example, the results show that two-quadrant gates are more likely to have gate-violation crashes than four-quadrant gates in Iowa, Illinois, Wisconsin and Minnesota. These states may need to receive more attentions on the enforcement of inhibiting gate-violation at crossings with two-quadrant gates or have the priority over other states to upgrade these crossings to four-quadrant gates if financially feasible. Copyright © 2017. Published by Elsevier Ltd.
Loregic: A Method to Characterize the Cooperative Logic of Regulatory Factors

PubMed Central

Wang, Daifeng; Yan, Koon-Kiu; Sisu, Cristina; Cheng, Chao; Rozowsky, Joel; Meyerson, William; Gerstein, Mark B.

2015-01-01

The topology of the gene-regulatory network has been extensively analyzed. Now, given the large amount of available functional genomic data, it is possible to go beyond this and systematically study regulatory circuits in terms of logic elements. To this end, we present Loregic, a computational method integrating gene expression and regulatory network data, to characterize the cooperativity of regulatory factors. Loregic uses all 16 possible two-input-one-output logic gates (e.g. AND or XOR) to describe triplets of two factors regulating a common target. We attempt to find the gate that best matches each triplet’s observed gene expression pattern across many conditions. We make Loregic available as a general-purpose tool (github.com/gersteinlab/loregic). We validate it with known yeast transcription-factor knockout experiments. Next, using human ENCODE ChIP-Seq and TCGA RNA-Seq data, we are able to demonstrate how Loregic characterizes complex circuits involving both proximally and distally regulating transcription factors (TFs) and also miRNAs. Furthermore, we show that MYC, a well-known oncogenic driving TF, can be modeled as acting independently from other TFs (e.g., using OR gates) but antagonistically with repressing miRNAs. Finally, we inter-relate Loregic’s gate logic with other aspects of regulation, such as indirect binding via protein-protein interactions, feed-forward loop motifs and global regulatory hierarchy. PMID:25884877
Analog and RF performance of a multigate FinFET at nano scale

NASA Astrophysics Data System (ADS)

Kumar, Abhishek

2016-12-01

In this paper, analog and RF performance of the Fin field effect transistor (FET) at Nano scale is observed through 3D simulation. FinFET devices like rectangular gate all around (RE-GAA) FinFET, cylindrical gate all around (CY-GAA) FinFET and triple gate (TG) FinFET are observed. The figure of merit (FOMs) such as input-output characteristics, trans-conductance (gm), output-conductance (gd), intrinsic gain (gm/gd), gate capacitance (gate to source and total gate capacitance), unity gain cut-off frequency (ft), trans-conductance generation factor (TGF), gain frequency product (GFP), gain bandwidth product (GBP) and gain transconductance frequency product (GTFP) are observed. The analog performance of a FinFETs are observed by realising source follower circuit with NMOS transistor as a current source. The source follower circuit gain is observed. It has been observed that maximum capacitance is observed in case gate all around condition. Rectangular gate all around has the highest transconductance. In the source follower circuit, the gain curve (Vout/Vin) is sharper for TG-FinFET.
Gating geometry studies of thin-walled 17-4PH investment castings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maguire, M.C.; Zanner, F.J.

1992-11-01

The ability to design gating systems that reliably feed and support investment castings is often the result of ``cut-and-try`` methodology. Factors such as hot tearing, porosity, cold shuts, misruns, and shrink are defects often corrected by several empirical gating design iterations. Sandia National Laboratories is developing rules that aid in removing the uncertainty involved in the design of gating systems for investment castings. In this work, gating geometries used for filling of thin walled investment cast 17-4PH stainless steel flat plates were investigated. A full factorial experiment evaluating the influence of metal pour temperature, mold preheat temperature, and mold channelmore » thickness were conducted for orientations that filled a horizontal flat plate from the edge. A single wedge gate geometry was used for the edge-gated configuration. Thermocouples placed along the top of the mold recorded metal front temperatures, and a real-time x-ray imaging system tracked the fluid flow behavior during filling of the casting. Data from these experiments were used to determine the terminal fill volumes and terminal fill times for each gate design.« less
Gating geometry studies of thin-walled 17-4PH investment castings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maguire, M.C.; Zanner, F.J.

1992-01-01

The ability to design gating systems that reliably feed and support investment castings is often the result of cut-and-try'' methodology. Factors such as hot tearing, porosity, cold shuts, misruns, and shrink are defects often corrected by several empirical gating design iterations. Sandia National Laboratories is developing rules that aid in removing the uncertainty involved in the design of gating systems for investment castings. In this work, gating geometries used for filling of thin walled investment cast 17-4PH stainless steel flat plates were investigated. A full factorial experiment evaluating the influence of metal pour temperature, mold preheat temperature, and mold channelmore » thickness were conducted for orientations that filled a horizontal flat plate from the edge. A single wedge gate geometry was used for the edge-gated configuration. Thermocouples placed along the top of the mold recorded metal front temperatures, and a real-time x-ray imaging system tracked the fluid flow behavior during filling of the casting. Data from these experiments were used to determine the terminal fill volumes and terminal fill times for each gate design.« less
Investigation of sensing mechanism and signal amplification in carbon nanotube based microfluidic liquid-gated transistors via pulsating gate bias.

PubMed

Wijaya, I Putu Mahendra; Nie, Tey Ju; Rodriguez, Isabel; Mhaisalkar, Subodh G

2010-06-07

The advent of a carbon nanotube liquid-gated transistor (LGFET) for biosensing applications allows the possibility of real-time and label-free detection of biomolecular interactions. The use of an aqueous solution as dielectric, however, has traditionally restricted the operating gate bias (VG) within |VG| < 1 V, due to the electrolysis of water. Here, we propose pulsed-gating as a facile method to extend the operation window of LGFETs to |VG| > 1 V. A comparison between simulation and experimental results reveals that at voltages in excess of 1 V, the LGFET sensing mechanism has a contribution from two factors: electrostatic gating as well as capacitance modulation. Furthermore, the large IDS drop observed in the |VG| > 1 V region indicates that pulsed-gating may be readily employed as a simple method to amplify the signal in the LGFET and pushes the detection limit down to attomolar concentration levels, an order of magnitude improvement over conventionally employed DC VG biasing.
Modelling the Factors that Affect Individuals' Utilisation of Online Learning Systems: An Empirical Study Combining the Task Technology Fit Model with the Theory of Planned Behaviour

ERIC Educational Resources Information Center

Yu, Tai-Kuei; Yu, Tai-Yi

2010-01-01

Understanding learners' behaviour, perceptions and influence in terms of learner performance is crucial to predict the use of electronic learning systems. By integrating the task-technology fit (TTF) model and the theory of planned behaviour (TPB), this paper investigates the online learning utilisation of Taiwanese students. This paper provides a…

Asthma-Like Symptoms in Homeless Children in the Greater Paris Area in 2013: Prevalence, Associated Factors and Utilization of Healthcare Services in the ENFAMS Survey.

PubMed

Lefeuvre, Delphine; Delmas, Marie-Christine; Marguet, Christophe; Chauvin, Pierre; Vandentorren, Stéphanie

2016-01-01

Asthma remains poorly studied in homeless children. We sought to estimate the prevalence of asthma-like symptoms (ALS) and to identify the factors associated with ALS and healthcare service utilisation. A cross-sectional survey of a random sample of sheltered homeless families was conducted by interviewing 801 parents of children (0-12 years) in 17 languages. ALS were defined as wheezing or night cough without fever during the previous year. Poisson regression models with robust error variance were used to compute prevalence ratios (PR) for factors associated with ALS and healthcare service utilisation for ALS. The prevalence of ALS among the children was 19.9%. Poor housing sanitation was significantly associated with ALS, as being born in the European Union. Most of the children with ALS had used healthcare services (85.4%). The main barriers to accessing such services were having lived in France for less than 49 months, having difficulties in French and living in poor housing conditions. ALS prevalence seemed lower than in the general child population, possibly because of the children's origins. Environmental factors associated with ALS point to the need to improve the indoor environment of family shelters. The relatively high rate of healthcare service utilisation should not overshadow existing barriers.
A radial sampling strategy for uniform k-space coverage with retrospective respiratory gating in 3D ultrashort-echo-time lung imaging.

PubMed

Park, Jinil; Shin, Taehoon; Yoon, Soon Ho; Goo, Jin Mo; Park, Jang-Yeon

2016-05-01

The purpose of this work was to develop a 3D radial-sampling strategy which maintains uniform k-space sample density after retrospective respiratory gating, and demonstrate its feasibility in free-breathing ultrashort-echo-time lung MRI. A multi-shot, interleaved 3D radial sampling function was designed by segmenting a single-shot trajectory of projection views such that each interleaf samples k-space in an incoherent fashion. An optimal segmentation factor for the interleaved acquisition was derived based on an approximate model of respiratory patterns such that radial interleaves are evenly accepted during the retrospective gating. The optimality of the proposed sampling scheme was tested by numerical simulations and phantom experiments using human respiratory waveforms. Retrospectively, respiratory-gated, free-breathing lung MRI with the proposed sampling strategy was performed in healthy subjects. The simulation yielded the most uniform k-space sample density with the optimal segmentation factor, as evidenced by the smallest standard deviation of the number of neighboring samples as well as minimal side-lobe energy in the point spread function. The optimality of the proposed scheme was also confirmed by minimal image artifacts in phantom images. Human lung images showed that the proposed sampling scheme significantly reduced streak and ring artifacts compared with the conventional retrospective respiratory gating while suppressing motion-related blurring compared with full sampling without respiratory gating. In conclusion, the proposed 3D radial-sampling scheme can effectively suppress the image artifacts due to non-uniform k-space sample density in retrospectively respiratory-gated lung MRI by uniformly distributing gated radial views across the k-space. Copyright © 2016 John Wiley & Sons, Ltd.
High-fidelity quantum gates on quantum-dot-confined electron spins in low-Q optical microcavities

NASA Astrophysics Data System (ADS)

Li, Tao; Gao, Jian-Cun; Deng, Fu-Guo; Long, Gui-Lu

2018-04-01

We propose some high-fidelity quantum circuits for quantum computing on electron spins of quantum dots (QD) embedded in low-Q optical microcavities, including the two-qubit controlled-NOT gate and the multiple-target-qubit controlled-NOT gate. The fidelities of both quantum gates can, in principle, be robust to imperfections involved in a practical input-output process of a single photon by converting the infidelity into a heralded error. Furthermore, the influence of two different decay channels is detailed. By decreasing the quality factor of the present microcavity, we can largely increase the efficiencies of these quantum gates while their high fidelities remain unaffected. This proposal also has another advantage regarding its experimental feasibility, in that both quantum gates can work faithfully even when the QD-cavity systems are non-identical, which is of particular importance in current semiconductor QD technology.
Determinants of antenatal and delivery care utilization in Tigray region, Ethiopia: a cross-sectional study.

PubMed

Tsegay, Yalem; Gebrehiwot, Tesfay; Goicolea, Isabel; Edin, Kerstin; Lemma, Hailemariam; Sebastian, Miguel San

2013-05-14

Despite the international emphasis in the last few years on the need to address the unmet health needs of pregnant women and children, progress in reducing maternal mortality has been slow. This is particularly worrying in sub-Saharan Africa where over 162,000 women still die each year during pregnancy and childbirth, most of them because of the lack of access to skilled delivery attendance and emergency care. With a maternal mortality ratio of 673 per 100,000 live births and 19,000 maternal deaths annually, Ethiopia is a major contributor to the worldwide death toll of mothers. While some studies have looked at different risk factors for antenatal care (ANC) and delivery service utilisation in the country, information coming from community-based studies related to the Health Extension Programme (HEP) in rural areas is limited. This study aims to determine the prevalence of maternal health care utilisation and explore its determinants among rural women aged 15-49 years in Tigray, Ethiopia. The study was a community-based cross-sectional survey using a structured questionnaire. A cluster sampling technique was used to select women who had given birth at least once in the five years prior to the survey period. Univariable and multivariable logistic regression analyses were carried out to elicit the impact of each factor on ANC and institutional delivery service utilisation. The response rate was 99% (n=1113). The mean age of the participants was 30.4 years. The proportion of women who received ANC for their recent births was 54%; only 46 (4.1%) of women gave birth at a health facility. Factors associated with ANC utilisation were marital status, education, proximity of health facility to the village, and husband's occupation, while use of institutional delivery was mainly associated with parity, education, having received ANC advice, a history of difficult/prolonged labour, and husbands' occupation. A relatively acceptable utilisation of ANC services but extremely low institutional delivery was observed. Classical socio-demographic factors were associated with both ANC and institutional delivery attendance. ANC advice can contribute to increase institutional delivery use. Different aspects of HEP need to be strengthened to improve maternal health in Tigray.
Implementation of ternary Shor’s algorithm based on vibrational states of an ion in anharmonic potential

NASA Astrophysics Data System (ADS)

Liu, Wei; Chen, Shu-Ming; Zhang, Jian; Wu, Chun-Wang; Wu, Wei; Chen, Ping-Xing

2015-03-01

It is widely believed that Shor’s factoring algorithm provides a driving force to boost the quantum computing research. However, a serious obstacle to its binary implementation is the large number of quantum gates. Non-binary quantum computing is an efficient way to reduce the required number of elemental gates. Here, we propose optimization schemes for Shor’s algorithm implementation and take a ternary version for factorizing 21 as an example. The optimized factorization is achieved by a two-qutrit quantum circuit, which consists of only two single qutrit gates and one ternary controlled-NOT gate. This two-qutrit quantum circuit is then encoded into the nine lower vibrational states of an ion trapped in a weakly anharmonic potential. Optimal control theory (OCT) is employed to derive the manipulation electric field for transferring the encoded states. The ternary Shor’s algorithm can be implemented in one single step. Numerical simulation results show that the accuracy of the state transformations is about 0.9919. Project supported by the National Natural Science Foundation of China (Grant No. 61205108) and the High Performance Computing (HPC) Foundation of National University of Defense Technology, China.
Extreme climatic conditions and health service utilisation across rural and metropolitan New South Wales

NASA Astrophysics Data System (ADS)

Jegasothy, Edward; McGuire, Rhydwyn; Nairn, John; Fawcett, Robert; Scalley, Benjamin

2017-08-01

Periods of successive extreme heat and cold temperature have major effects on human health and increase rates of health service utilisation. The severity of these events varies between geographic locations and populations. This study aimed to estimate the effects of heat waves and cold waves on health service utilisation across urban, regional and remote areas in New South Wales (NSW), Australia, during the 10-year study period 2005-2015. We divided the state into three regions and used 24 over-dispersed or zero-inflated Poisson time-series regression models to estimate the effect of heat waves and cold waves, of three levels of severity, on the rates of ambulance call-outs, emergency department (ED) presentations and mortality. We defined heat waves and cold waves using excess heat factor (EHF) and excess cold factor (ECF) metrics, respectively. Heat waves generally resulted in increased rates of ambulance call-outs, ED presentations and mortality across the three regions and the entire state. For all of NSW, very intense heat waves resulted in an increase of 10.8% (95% confidence interval (CI) 4.5, 17.4%) in mortality, 3.4% (95% CI 0.8, 7.8%) in ED presentations and 10.9% (95% CI 7.7, 14.2%) in ambulance call-outs. Cold waves were shown to have significant effects on ED presentations (9.3% increase for intense events, 95% CI 8.0-10.6%) and mortality (8.8% increase for intense events, 95% CI 2.1-15.9%) in outer regional and remote areas. There was little evidence for an effect from cold waves on health service utilisation in major cities and inner regional areas. Heat waves have a large impact on health service utilisation in NSW in both urban and rural settings. Cold waves also have significant effects in outer regional and remote areas. EHF is a good predictor of health service utilisation for heat waves, although service needs may differ between urban and rural areas.
Polysilicon Gate Enhancement of the Random Dopant Induced Threshold Voltage Fluctuations in Sub-100 nm MOSFET's with Ultrathin Gate Oxide

NASA Technical Reports Server (NTRS)

Asenov, Asen; Saini, Subhash

2000-01-01

In this paper, we investigate various aspects of the polysilicon gate influence on the random dopant induced threshold voltage fluctuations in sub-100 nm MOSFET's with ultrathin gate oxides. The study is done by using an efficient statistical three-dimensional (3-D) "atomistic" simulation technique described else-where. MOSFET's with uniform channel doping and with low doped epitaxial channels have been investigated. The simulations reveal that even in devices with a single crystal gate the gate depletion and the random dopants in it are responsible for a substantial fraction of the threshold voltage fluctuations when the gate oxide is scaled-in the range of 1-2 nm. Simulation experiments have been used in order to separate the enhancement in the threshold voltage fluctuations due to an effective increase in the oxide thickness associated with the gate depletion from the direct influence of the random dopants in the gate depletion layer. The results of the experiments show that the both factors contribute to the enhancement of the threshold voltage fluctuations, but the effective increase in the oxide-thickness has a dominant effect in the investigated range of devices. Simulations illustrating the effect or the polysilicon grain boundaries on the threshold voltage variation are also presented.
African American women's preventative care usage: the role of social support and racial experiences and attitudes.

PubMed

Pullen, Erin; Perry, Brea; Oser, Carrie

2014-09-01

Research suggests that African Americans are less likely to utilise preventative care services than Americans of European descent, and that these patterns may contribute to racial health disparities in the United States. Despite the persistence of inequalities in preventative care utilisation, culturally relevant factors influencing the use of these gateway health services have been understudied among marginalised groups. Using a stratified sample of 205 low-income African American women, this research examines the predictors of receiving a physical exam, with a particular emphasis on how differing levels of social support from friend and family networks and experiences of racial discrimination and cultural mistrust shape utilisation. The findings underscore the importance of traditional predictors of utilisation, including insurance status and having a usual physician. However, they also indicate that supportive ties to friendship networks are associated with higher predicted rates of having an annual physical exam, while social support from family and sentiments of cultural mistrust are associated with lower rates of utilisation. Broadly, the findings indicate that even as traditional predictors of help-seeking become less relevant, it will be critical to explore how variations in discrimination experiences and social relationships across marginalised groups drive patterns of preventative care utilisation. © 2014 The Authors. Sociology of Health & Illness © 2014 Foundation for the Sociology of Health & Illness/John Wiley & Sons Ltd.
Impact of metal gates on remote phonon scattering in titanium nitride/hafnium dioxide n-channel metal-oxide-semiconductor field effect transistors-low temperature electron mobility study

NASA Astrophysics Data System (ADS)

Maitra, Kingsuk; Frank, Martin M.; Narayanan, Vijay; Misra, Veena; Cartier, Eduard A.

2007-12-01

We report low temperature (40-300 K) electron mobility measurements on aggressively scaled [equivalent oxide thickness (EOT)=1 nm] n-channel metal-oxide-semiconductor field effect transistors (nMOSFETs) with HfO2 gate dielectrics and metal gate electrodes (TiN). A comparison is made with conventional nMOSFETs containing HfO2 with polycrystalline Si (poly-Si) gate electrodes. No substantial change in the temperature acceleration factor is observed when poly-Si is replaced with a metal gate, showing that soft optical phonons are not significantly screened by metal gates. A qualitative argument based on an analogy between remote phonon scattering and high-resolution electron energy-loss spectroscopy (HREELS) is provided to explain the underlying physics of the observed phenomenon. It is also shown that soft optical phonon scattering is strongly damped by thin SiO2 interface layers, such that room temperature electron mobility values at EOT=1 nm become competitive with values measured in nMOSFETs with SiON gate dielectrics used in current high performance processors.
COPD: Health Care Utilisation Patterns with Different Disease Management Interventions.

PubMed

Luk, Edwin K; Hutchinson, Anastasia F; Tacey, Mark; Irving, Louis; Khan, Fary

2017-08-01

The management of COPD is a significant and costly issue worldwide, with acute healthcare utilisation consisting of admissions and outpatient attendances being a major contributor to the cost. Pulmonary rehabilitation (PR) and integrated disease management (IDM) are often offered. Whilst there is strong evidence of physical and quality of life outcomes following IDM and PR, few studies have looked into healthcare utilisation. The aims of this study were to confirm whether IDM and PR reduce acute healthcare utilisation and to identify factors which contribute to acute health care utilisation or increased mortality. This was a retrospective cohort study of patients with COPD who were referred to IDM over a 10-year period. Patients were also offered an 8-week PR program. Data collected were matched with the hospital dataset to obtain information on inpatient, ED and outpatient attendances. 517 patients were enrolled to IDM. 315 (61%) also commenced PR and 220 (43%) completed PR. Patients who were referred to PR were younger and had less comorbidities (p < 0.001). Both groups (IDM only and IDM + PR referred) had reductions in healthcare utilisation but the IDM-only group had greater reductions. A survival benefit (HR 0.68, 95% CI 0.50-0.92) was seen in those who were PR completers compared to patients who received IDM only. Patients with COPD who successfully complete PR in addition to participating in IDM have improved survival. IDM alone was effective in the reduction of healthcare utilisation; however, the addition of PR did not reduce healthcare usage further.
Demand and utilisation of labour analgesia service by Nigerian women.

PubMed

Imarengiaye, C O; Ande, A B A

2006-02-01

This study sought to determine the clinical correlates of the demand and utilisation of labour analgesia resources by Nigerian women in labour. All consenting women were interviewed on arrival at the Unit and while in labour. Biodata, options for relief of labour pain, request for analgesia, method of analgesia, VAS score and cervical score at time of request for analgesia were obtained. A total of 288 women in labour were studied. Of these, 108 (37.5%) patients were aware that the pain of labour can be relieved but only 26.0% had prenatal information on labour analgesia. However, 85.1% of the patients would want their pain of labour relieved. A total of 112 (38.9%) did receive analgesia during labour. Cervical dilatation of <4 cm at presentation to the Unit and nulliparity were likely factors for pain treatment during labour (p = 0.001, chi2 test). There is poor utilisation of labour analgesia services. Improved antenatal information on labour analgesia may boost the utilisation of these resources by Nigerian women in labour.
Research in Evaluation Methods for Data Fusion-Capable Tactical Platforms and Distributed Multi-platform Systems in Electronic Warfare and Information-Warfare Related Missions

DTIC Science & Technology

2009-02-01

They support their launches until both outside reds are killed or until second shots are needed. In the baseline scenario shown, US2 achieves 2 kills ...red 5/6 kills . The SUT gate multiplication factor was 5 and 15. The PE gate multiplication factors of 3 and 5, PE designs for Vogel and Hungarian... ploughed in various sections of this land by splitting it into sub plots came to be known as the subplot factor. Such a design is used only when there
Barriers to utilisation of antenatal care services in South Sudan: a qualitative study in Rumbek North County.

PubMed

Wilunda, Calistus; Scanagatta, Chiara; Putoto, Giovanni; Montalbetti, Francesca; Segafredo, Giulia; Takahashi, Risa; Mizerero, Serge André; Betrán, Ana Pilar

2017-05-22

Access to adequate antenatal care (ANC) is critical in ensuring a good maternal health and in preventing maternal and neonatal morbidity and mortality. South Sudan has one of the world's poorest health indicators due to a fragile health system and a combination of socio-cultural, economic, and political factors. This study was conducted to identify barriers to utilisation of ANC services in Rumbek North County. Using a qualitative design, data were collected through 14 focus group discussions with 169 women and 45 men and 12 key informant interviews with community leaders, staff working in health facilities, and the staff of the County Health Department. Data were analysed using inductive content analysis. The perceived barriers to ANC utilisation were categorised as follows: 1) Issues related to access to health facilities and lack of resources. These included long distance to health facilities, lack of means of transportation to the health facilities, floods and poor roads, and demand for payment for health care at some health facilities; 2) The influence of the socio-cultural context and conflict including heavy burden of domestic chores, the negative influence of husbands who were reluctant to allow their wives to attend ANC, and insecurity; 3) Perceptions about pregnancy including misperceptions about the benefits of ANC and low perceived risk of pregnancy-related complications; and 4) Perceptions about the quality of care and the efficacy of medical treatment. This study identified a myriad of factors deeply entrenched in the society, which prevent women from utilising ANC services. It also elicits broad aspects of interconnectedness among the barriers. To ensure effectiveness, strategies to improve utilisation of ANC in the study area and in similar contexts need to take into account the barriers identified by this study.
Voltage-Gated Sodium Channels: Evolutionary History and Distinctive Sequence Features.

PubMed

Kasimova, M A; Granata, D; Carnevale, V

2016-01-01

Voltage-gated sodium channels (Nav) are responsible for the rising phase of the action potential. Their role in electrical signal transmission is so relevant that their emergence is believed to be one of the crucial factors enabling development of nervous system. The presence of voltage-gated sodium-selective channels in bacteria (BacNav) has raised questions concerning the evolutionary history of the ones in animals. Here we review some of the milestones in the field of Nav phylogenetic analysis and discuss some of the most important sequence features that distinguish these channels from voltage-gated potassium channels and transient receptor potential channels. Copyright © 2016 Elsevier Inc. All rights reserved.
Dynamical decoupling of local transverse random telegraph noise in a two-qubit gate

NASA Astrophysics Data System (ADS)

D'Arrigo, A.; Falci, G.; Paladino, E.

2015-10-01

Achieving high-fidelity universal two-qubit gates is a central requisite of any implementation of quantum information processing. The presence of spurious fluctuators of various physical origin represents a limiting factor for superconducting nanodevices. Operating qubits at optimal points, where the qubit-fluctuator interaction is transverse with respect to the single qubit Hamiltonian, considerably improved single qubit gates. Further enhancement has been achieved by dynamical decoupling (DD). In this article we investigate DD of transverse random telegraph noise acting locally on each of the qubits forming an entangling gate. Our analysis is based on the exact numerical solution of the stochastic Schrödinger equation. We evaluate the gate error under local periodic, Carr-Purcell and Uhrig DD sequences. We find that a threshold value of the number, n, of pulses exists above which the gate error decreases with a sequence-specific power-law dependence on n. Below threshold, DD may even increase the error with respect to the unconditioned evolution, a behaviour reminiscent of the anti-Zeno effect.
Noise-margin limitations on gallium-arsenide VLSI

NASA Technical Reports Server (NTRS)

Long, Stephen I.; Sundaram, Mani

1988-01-01

Two factors which limit the complexity of GaAs MESFET VLSI circuits are considered. Power dissipation sets an upper complexity limit for a given logic circuit implementation and thermal design. Uniformity of device characteristics and the circuit configuration determines the electrical functional yield. Projection of VLSI complexity based on these factors indicates that logic chips of 15,000 gates are feasible with the most promising static circuits if a maximum power dissipation of 5 W per chip is assumed. While lower power per gate and therefore more gates per chip can be obtained by using a popular E/D FET circuit, yields are shown to be small when practical device parameter tolerances are applied. Further improvements in materials, devices, and circuits wil be needed to extend circuit complexity to the range currently dominated by silicon.
Free-breathing 3D Cardiac MRI Using Iterative Image-Based Respiratory Motion Correction

PubMed Central

Moghari, Mehdi H.; Roujol, Sébastien; Chan, Raymond H.; Hong, Susie N.; Bello, Natalie; Henningsson, Markus; Ngo, Long H.; Goddu, Beth; Goepfert, Lois; Kissinger, Kraig V.; Manning, Warren J.; Nezafat, Reza

2012-01-01

Respiratory motion compensation using diaphragmatic navigator (NAV) gating with a 5 mm gating window is conventionally used for free-breathing cardiac MRI. Due to the narrow gating window, scan efficiency is low resulting in long scan times, especially for patients with irregular breathing patterns. In this work, a new retrospective motion compensation algorithm is presented to reduce the scan time for free-breathing cardiac MRI that increasing the gating window to 15 mm without compromising image quality. The proposed algorithm iteratively corrects for respiratory-induced cardiac motion by optimizing the sharpness of the heart. To evaluate this technique, two coronary MRI datasets with 1.3 mm3 resolution were acquired from 11 healthy subjects (7 females, 25±9 years); one using a NAV with a 5 mm gating window acquired in 12.0±2.0 minutes and one with a 15 mm gating window acquired in 7.1±1.0 minutes. The images acquired with a 15 mm gating window were corrected using the proposed algorithm and compared to the uncorrected images acquired with the 5 mm and 15 mm gating windows. The image quality score, sharpness, and length of the three major coronary arteries were equivalent between the corrected images and the images acquired with a 5 mm gating window (p-value>0.05), while the scan time was reduced by a factor of 1.7. PMID:23132549
Social factors influencing hospital utilisation by tuberculosis patients in the Russian Federation: analysis of routinely collected data.

PubMed

Atun, R A; Samyshkin, Y A; Drobniewski, F; Kuznetsov, S I; Fedorin, I M; Coker, R J

2005-10-01

To establish whether admissions, discharges and hospital utilisation for tuberculosis (TB) in Russia are independent of sex, age, disability and employment status. Analysis of hospital admissions, discharges and in-patient utilisation using routinely collected data in Samara Region of the Russian Federation. Male, unemployed and disabled adults were significantly more likely to be hospitalised (P < 0.001). The unemployed and pensioners were more likely to have multiple admissions. Unemployed adults were more likely to have longer average lengths of stay per admission (P < 0.001), with a cumulative length of stay for unemployed and disabled adults significantly greater than for employed adults and adults with no disability. Interruption of hospital care was significantly more frequent in male, disabled and unemployed patients (P < 0.001). Socio-economic factors influence hospital admission patterns and the length of stay for patients when hospitalised, as the providers of TB services attempt to mitigate the lack of social care provision for patients. For the WHO DOTS strategy to be effectively implemented and sustained in the Russian Federation health system, social sector linkage issues need to be addressed.
Factors affecting speech understanding in gated interference: Cochlear implant users and normal-hearing listeners

NASA Astrophysics Data System (ADS)

Nelson, Peggy B.; Jin, Su-Hyun

2004-05-01

Previous work [Nelson, Jin, Carney, and Nelson (2003), J. Acoust. Soc. Am 113, 961-968] suggested that cochlear implant users do not benefit from masking release when listening in modulated noise. The previous findings indicated that implant users experience little to no release from masking when identifying sentences in speech-shaped noise, regardless of the modulation frequency applied to the noise. The lack of masking release occurred for all implant subjects who were using three different devices and speech processing strategies. In the present study, possible causes of this reduced masking release in implant listeners were investigated. Normal-hearing listeners, implant users, and normal-hearing listeners presented with a four-band simulation of a cochlear implant were tested for their understanding of sentences in gated noise (1-32 Hz gate frequencies) when the duty cycle of the noise was varied from 25% to 75%. No systematic effect of noise duty cycle on implant and simulation listeners' performance was noted, indicating that the masking caused by gated noise is not only energetic masking. Masking release significantly increased when the number of spectral channels was increased from 4 to 12 for simulation listeners, suggesting that spectral resolution is important for masking release. Listeners were also tested for their understanding of gated sentences (sentences in quiet interrupted by periods of silence ranging from 1 to 32 Hz as a measure of auditory fusion, or the ability to integrate speech across temporal gaps. Implant and simulation listeners had significant difficulty understanding gated sentences at every gate frequency. When the number of spectral channels was increased for simulation listeners, their ability to understand gated sentences improved significantly. Findings suggest that implant listeners' difficulty understanding speech in modulated conditions is related to at least two (possibly related) factors: degraded spectral information and limitations in auditory fusion across temporal gaps.
Noise removal using factor analysis of dynamic structures: application to cardiac gated studies.

PubMed

Bruyant, P P; Sau, J; Mallet, J J

1999-10-01

Factor analysis of dynamic structures (FADS) facilitates the extraction of relevant data, usually with physiologic meaning, from a dynamic set of images. The result of this process is a set of factor images and curves plus some residual activity. The set of factor images and curves can be used to retrieve the original data with reduced noise using an inverse factor analysis process (iFADS). This improvement in image quality is expected because the inverse process does not use the residual activity, assumed to be made of noise. The goal of this work is to quantitate and assess the efficiency of this method on gated cardiac images. A computer simulation of a planar cardiac gated study was performed. The simulated images were added with noise and processed by the FADS-iFADS program. The signal-to-noise ratios (SNRs) were compared between original and processed data. Planar gated cardiac studies from 10 patients were tested. The data processed by FADS-iFADS were subtracted to the original data. The result of the substraction was studied to evaluate its noisy nature. The SNR is about five times greater after the FADS-iFADS process. The difference between original and processed data is noise only, i.e., processed data equals original data minus some white noise. The FADS-iFADS process is successful in the removal of an important part of the noise and therefore is a tool to improve the image quality of cardiac images. This tool does not decrease the spatial resolution (compared with smoothing filters) and does not lose details (compared with frequential filters). Once the number of factors is chosen, this method is not operator dependent.

Research utilisation and critical thinking among newly graduated nurses: predictors for research use. A quantitative cross-sectional study.

PubMed

Wangensteen, Sigrid; Johansson, Inger S; Björkström, Monica E; Nordström, Gun

2011-09-01

The aim was to describe research utilisation among newly graduated nurses and to explore critical thinking dispositions and other individual and contextual factors as possible predictors for research use. Nurses are expected to be research users, and variations in research utilisation are explained by individual and contextual factors. To our knowledge, critical thinking dispositions have not earlier been explored as predictors for research use. A cross-sectional design was chosen. Data collection was carried out from October 2006 to April 2007 using the Research Utilization Questionnaire (RUQ) and the California Critical Thinking Disposition Inventory (CCTDI). The response rate was 33% (n =617). Pearson's chi-square test and regression analyses were used for statistical calculations. The respondents reported a positive attitude towards research, but only 24% (n = 148) were defined as research users. A significantly higher proportion of research users reported high critical thinking scores. Critical thinking explained 20% of the variance in attitude towards research and 11% of the variance in research use. Availability and support to implement research findings was the second strongest predictor for research use. Critical thinking, a significant predictor for attitude towards research and for the use of research, should be recognised and strengthened in nursing education and clinical practice. Contextual factors seem to be important for newly graduated nurses' use of research. Nurse leaders play an important role in nurturing newly graduated nurses' critical thinking and assisting them in transferring their positive attitude towards research into research use. Nurse educators play a significant role in supporting, challenging and supervising nursing students to be critical thinkers and strong believers in research utilisation. © 2011 Blackwell Publishing Ltd.
Utilisation of prehospital emergency medical services for hyperglycaemia: A community-based observational study.

PubMed

Villani, Melanie; Nanayakkara, Natalie; Ranasinha, Sanjeeva; Earnest, Arul; Smith, Karen; Soldatos, Georgia; Teede, Helena; Zoungas, Sophia

2017-01-01

This study examines prehospital Emergency Medical Service (EMS) utilisation and patterns of demand for hyperglycaemia management, including characteristics of individuals and factors related to hospital transport. A state-wide, community-based observational study of all patients requiring prehospital EMS for hyperglycaemia during a 7 year study period (Jan 2009-Dec 2015) using electronic data from the Ambulance Victoria data warehouse was conducted. Pre-specified variables related to patient demographics, comorbidities, examination findings, paramedic treatment and transport outcomes were obtained. Logistic regression was used to assess factors associated with transport to hospital. There were 11,417 cases of hyperglycaemia attended by paramedics during the study period, accounting for 0.3-0.4% of the total annual EMS caseload, and equating to 0.54 attendances per 100 people with diabetes in the state of Victoria, Australia, per year. There was a significant increase in annual utilisation, with a rate ratio of 1.62 between 2009 (2.42 cases per 10,000 population) and 2015 (3.91 cases per 10,000 population). Fifty-one percent of cases had type 2 diabetes, 37% had type 1 diabetes, 4% had diabetes with the type unspecified and 8% had no recorded history of diabetes. Ninety percent of cases were transported to hospital. Factors associated with increased odds of transport to hospital included no known history of diabetes, regional/rural locations, case time between 0600 and <1800 hours, increasing number of comorbidities and increasingly unstable vital sign observations. There is substantial utilisation of prehospital EMS for hyperglycaemia. With increased population prevalence of diabetes predicted, further research on opportunities for prevention, as well as optimal management in the prehospital environment is warranted.
The effect of split gate dimensions on the electrostatic potential and 0.7 anomaly within one-dimensional quantum wires on a modulation doped GaAs/AlGaAs heterostructure

NASA Astrophysics Data System (ADS)

Smith, L. W.; Al-Taie, H.; Lesage, A. A. J.; Thomas, K. J.; Sfigakis, F.; See, P.; Griffiths, J. P.; Farrer, I.; Jones, G. A. C.; Ritchie, D. A.; Kelly, M. J.; Smith, C. G.

We use a multiplexing scheme to measure the conductance properties of 95 split gates of 7 different gate dimensions fabricated on a GaAs/AlGaAs chip, in a single cool down. The number of devices for which conductance is accurately quantized reduces as the gate length increases. However, even the devices for which conductance is accurately quantized in units of 2e2 / h show no correlation between the length of electrostatic potential barrier in the channel and the gate length, using a saddle point model to estimate the barrier length. Further, the strength of coupling between the gates and the 1D channel does not increase with gate length beyond 0.7 μm. The background electrostatic profile appears as significant as the gate dimension in determining device behavior. We find a clear correlation between the curvature of the electrostatic barrier along the channel and the strength of the ``0.7 anomaly'' which identifies the electrostatic length of the channel as the principal factor governing the conductance of the 0.7 anomaly. Present address: Wisconsin Institute for Quantum Information, University of Wisconsin-Madison, Madison, WI.
Simulation of all-optical logic NOR gate based on two-photon absorption with semiconductor optical amplifier-assisted Mach-Zehnder interferometer with the effect of amplified spontaneous emission

NASA Astrophysics Data System (ADS)

Kotb, Amer

2015-05-01

The performance of an all-optical NOR gate is numerically simulated and investigated. The NOR Boolean function is realized by using a semiconductor optical amplifier (SOA) incorporated in Mach-Zehnder interferometer (MZI) arms and exploiting the nonlinear effect of two-photon absorption (TPA). If the input pulse intensities is adjusting to be high enough, the TPA-induced phase change can be larger than the regular gain-induced phase change and hence support ultrafast operation in the dual rail switching mode. The numerical study is carried out by taking into account the effect of the amplified spontaneous emission (ASE). The dependence of the output quality factor ( Q-factor) on critical data signals and SOAs parameters is examined and assessed. The obtained results confirm that the NOR gate implemented with the proposed scheme is capable of operating at a data rate of 250 Gb/s with logical correctness and high output Q-factor.
Dependence of electrical and time stress in organic field effect transistor with low temperature forming gas treated Al2O3 gate dielectrics.

PubMed

Lee, Sunwoo; Chung, Keum Jee; Park, In-Sung; Ahn, Jinho

2009-12-01

We report the characteristics of the organic field effect transistor (OFET) after electrical and time stress. Aluminum oxide (Al2O3) was used as a gate dielectric layer. The surface of the gate oxide layer was treated with hydrogen (H2) and nitrogen (N2) mixed gas to minimize the dangling bond at the interface layer of gate oxide. According to the two stress parameters of electrical and time stress, threshold voltage shift was observed. In particular, the mobility and subthreshold swing of OFET were significantly decreased due to hole carrier localization and degradation of the channel layer between gate oxide and pentacene by electrical stress. Electrical stress is a more critical factor in the degradation of mobility than time stress caused by H2O and O2 in the air.
Fast Dynamical Decoupling of the Mølmer-Sørensen Entangling Gate.

PubMed

Manovitz, Tom; Rotem, Amit; Shaniv, Ravid; Cohen, Itsik; Shapira, Yotam; Akerman, Nitzan; Retzker, Alex; Ozeri, Roee

2017-12-01

Engineering entanglement between quantum systems often involves coupling through a bosonic mediator, which should be disentangled from the systems at the operation's end. The quality of such an operation is generally limited by environmental and control noise. One of the prime techniques for suppressing noise is by dynamical decoupling, where one actively applies pulses at a rate that is faster than the typical time scale of the noise. However, for boson-mediated gates, current dynamical decoupling schemes require executing the pulses only when the boson and the quantum systems are disentangled. This restriction implies an increase of the gate time by a factor of sqrt[N], with N being the number of pulses applied. Here we propose and realize a method that enables dynamical decoupling in a boson-mediated system where the pulses can be applied while spin-boson entanglement persists, resulting in an increase in time that is at most a factor of π/2, independently of the number of pulses applied. We experimentally demonstrate the robustness of our entangling gate with fast dynamical decoupling to σ_{z} noise using ions in a Paul trap.
An analysis of the costs of treating schizophrenia in Spain: a hierarchical Bayesian approach.

PubMed

Vázquez-Polo, Francisco-Jose; Negrín, Miguel; Cabasés, Juan M; Sánchez, Eduardo; Haro, Joseph M; Salvador-Carulla, Luis

2005-09-01

Health care decisions should incorporate cost of illness and treatment data, particularly for disorders such as schizophrenia with a high morbidity rate and a disproportionately low allocation of resources. Previous cost of illness analyses may have disregarded geographical aspects relevant for resource consumption and unit cost calculation. To compare the utilisation of resources and the care costs of schizophrenic patients in four mental-health districts in Spain (in Madrid, Catalonia, Navarra and Andalusia), and to analyse factors that determine the costs and the differences between areas. A treated prevalence bottom-up three year follow-up design was used for obtaining data concerning socio-demography, clinical evolution and the utilisation of services. 1997 reference prices were updated for years 1998-2000 in euros. We propose two different scenarios, varying in the prices applied. In the first (Scenario 0) the reference prices are those obtained for a single geographic area, and so the cost variations are only due to differences in the use of resources. In the second situation (Scenario 1), we analyse the variations in resource utilisation at different levels, using the prices applicable to each healthcare area. Bayesian hierarchical models are used to discuss the factors that determine such costs and the differences between geographic areas. In scenario 0, the estimated mean cost was 4918.948 euros for the first year. In scenario 1 the highest cost was in Gava (Catalonia) and the lowest in Loja (Andalusia). Mean costs were respectively 4547.24 and 2473.98 euros. With respect to the evolution of costs over time, we observed an increase during the second year and a reduction during the third year. Geographical differences appeared in follow-up costs. The variables related to lower treatment costs were: residence in the family household, higher patient age and being in work. On the contrary, the number of relapses is directly related to higher treatment costs. No differences were observed between health areas concerning resource utilisation. Calculating the costs of a given disease involves two principal factors: the resource utilisation and the prices. In most studies, emphasis is placed on the analysis of resource utilisation. Other evaluations, however, have recognized the implications of incorporating different prices into the final results. In this study we show both scenarios. The factors that determine the cost of schizophrenia for the Spanish case are similar to the factors encountered in studies carried out in other countries. Treatment costs may be reduced by the prevention of psychotic symptoms and relapse. The use of the same price data in multicentre studies may not be realistic. More effort should be made to obtain price data from all the centres or countries participating in a study. In the present study, only direct healthcare and social costs have been included. Future research should consider informal and indirect costs.
Parental decision-making on utilisation of out-of-home respite in children's palliative care: findings of qualitative case study research - a proposed new model.

PubMed

Ling, J; Payne, S; Connaire, K; McCarron, M

2016-01-01

Respite in children's palliative care aims to provide a break for family's from the routine of caring. Parental decision-making regarding the utilisation of out-of-home respite is dependent on many interlinking factors including the child's age, diagnosis, geographical location and the family's capacity to meet their child's care needs. A proposed model for out-of-home respite has been developed based on the findings of qualitative case study research. Utilising multiple, longitudinal, qualitative case study design, the respite needs and experiences of parents caring for a child with a life-limiting condition were explored. Multiple, in-depth interviews were undertaken with the parents identified by a hospital-based children's palliative care team. Data were analysed using thematic analysis. Each individual case consists of a whole study. Cross-case comparison was also conducted. Nine families were recruited and followed for two years. A total of 19 in-depth interviews were conducted with mothers and fathers (one or both) caring for a child with a life-limiting condition in Ireland. Each family reported vastly different needs and experiences of respite from their own unique perspective. Cross-case comparison showed that for all parents utilising respite care, regardless of their child's age and condition, home was the location of choice. Many interlinking factors influencing these decisions included: past experience of in-patient care, and trust and confidence in care providers. Issues were raised regarding the impact of care provision in the home on family life, siblings and the concept of home. Respite is an essential element of children's palliative care. Utilisation of out-of-home respite is heavily dependent on a number of interlinked and intertwined factors. The proposed model of care offers an opportunity to identify how these decisions are made and may ultimately assist in identifying the elements of responsive and family-focused respite that are important to families of children with life-limiting conditions. © 2015 John Wiley & Sons Ltd.
Factors associated with the utilisation of postnatal care services among the mothers of Nepal: analysis of Nepal Demographic and Health Survey 2011

PubMed Central

2014-01-01

Background Postnatal care is essential to save the life of the mother and newborn. Knowledge on the determinants of postnatal care assists the policy makers to design, justify and implement appropriate interventions. The current study aimed to analyse the factors associated with utilisation of postnatal care services by mothers in Nepal based on the data from Nepal Demographic and Health Survey (NDHS) 2011. Methods This study utilised the data from NDHS 2011. The association between utilisation of at least one postnatal care visit (within 6 weeks of delivery) and immediate postnatal care (within 24 hours of delivery) with selected factors was examined by using Chi-square test (χ2), followed by multiple logistic regression. Result Of the 4079 mothers, 43.2% reported attending postnatal care within the first six weeks of birth, while 40.9% reported attending immediate postnatal care. Mothers who were from urban areas, from rich families, who were educated, whose partners were educated, who delivered in a health facility, who had attended a four or more antenatal visits, and whose delivery was attended by a skilled attendant were more likely to report attending at least one postnatal care visit. On the other hand, mothers who reported agricultural occupation, and whose partners performed agricultural occupation were less likely to have attended at least one postnatal care visit. Similarly, mothers who were from the urban areas, from rich families, who were educated, whose partners were educated, who had attended four or more antenatal visits, who delivered in a health facility and had delivered in the presence of a skilled birth attendant were more likely to report attending immediate postnatal care. Mothers who reported agricultural occupation, and whose partners performed agricultural occupation were less likely to attend immediate postnatal care. Conclusion The majority of postnatal mothers in Nepal did not seek postnatal care. Increasing utilisation of the recommended four or more antenatal visits, delivery at health facility and increasing awareness and access to services through community-based programs especially for the rural, poor, and less educated mothers may increase postnatal care attendance in Nepal. PMID:24484933
The significance of the concept of disease for justice in health care.

PubMed

Schramme, Thomas

2007-01-01

In this paper, I want to scrutinise the value of utilising the concept of disease for a theory of distributive justice in health care. Although many people believe that the presence of a disease-related condition is a prerequisite of a justified claim on health care resources, the impact of the philosophical debate on the concept of disease is still relatively minor. This is surprising, because how we conceive of disease determines the amount of justified claims on health care resources. Therefore, the severity of scarcity depends on our interpretation of the concept of disease. I want to defend a specific combination of a theory of disease with a theory of distributive justice. A naturalist account of disease, together with sufficientarianism, is able to perform a gate-keeping function regarding entitlements to medical treatment. Although this combination cannot solve all problems of justice in health care, it may inform rationing decisions as well.
General practitioners and neurotelemedicine.

PubMed

Araújo, M T; Paiva, T; Jesuino, J C; Magalhães, M

2000-01-01

Predicting attitudes towards teleconsultation systems and intentions of use is crucial at the beginning of the implementation phase, due to the critical role of human factors in its acceptance and continuous utilisation. The main objective of this study was to assess and understand GP's attitudes and intentions towards using the teleconsultation system in Neurology, implemented in Lisbon, between Hospital de Santa Maria/Neurology Outpatient Clinic and the Health Care Centers of its Health Unit. The final aim is the promotion of a wide acceptance and utilisation of the system, through the development of adequate communication strategies. A predictive model "Theory of Reasoned Action" was chosen as method. It was operated with the application of a questionnaire to a sample of 53 GP's, developed from the results of a content analysis of 10 interviews. A total of 44 GP's stated that, probably they will use the system, 5 were neutral and 4 probably will not use it. The responses were submitted to factor and multiple regression analysis. Attitude was determined by only one factor "Accessibility and Quality" (b = 0.486; p = 0.007) from the 5 factors obtained. The intention variance was explained in 26.9% by the attitude and subjective norm. However, only the attitudinal factor (b = 0.469; p = 0.002) contributes significantly to its explanation with no significant influence from the subjective norm. GP's intentions towards using the system are very positive. Nevertheless, there are significant differences between the centers that are participating and not participating in the project. Communication strategies envisaging dissemination and generalised acceptance and utilisation should focus on accessibility and quality of care aspects.
Analysis of Academic Administrators' Attitudes: Annual Evaluations and Factors That Improve Teaching

ERIC Educational Resources Information Center

Cherry, Brian D.; Grasse, Nathan; Kapla, Dale; Hamel, Brad

2017-01-01

This article examines academic administrators' attitudes towards the academic evaluation process in the US and those factors that are utilised to improve teaching. We use path regressions to examine satisfaction with evaluation procedures, as well as the direct and indirect effects of these factors on perceptions of whether the evaluation process…
Factors that influence the efficiency of beef and dairy cattle recording system in Kenya: A SWOT-AHP analysis.

PubMed

Wasike, Chrilukovian B; Magothe, Thomas M; Kahi, Alexander K; Peters, Kurt J

2011-01-01

Animal recording in Kenya is characterised by erratic producer participation and high drop-out rates from the national recording scheme. This study evaluates factors influencing efficiency of beef and dairy cattle recording system. Factors influencing efficiency of animal identification and registration, pedigree and performance recording, and genetic evaluation and information utilisation were generated using qualitative and participatory methods. Pairwise comparison of factors was done by strengths, weaknesses, opportunities and threats-analytical hierarchical process analysis and priority scores to determine their relative importance to the system calculated using Eigenvalue method. For identification and registration, and evaluation and information utilisation, external factors had high priority scores. For pedigree and performance recording, threats and weaknesses had the highest priority scores. Strengths factors could not sustain the required efficiency of the system. Weaknesses of the system predisposed it to threats. Available opportunities could be explored as interventions to restore efficiency in the system. Defensive strategies such as reorienting the system to offer utility benefits to recording, forming symbiotic and binding collaboration between recording organisations and NARS, and development of institutions to support recording were feasible.
How to identify, assess and utilise mobile medical applications in clinical practice.

PubMed

Aungst, T D; Clauson, K A; Misra, S; Lewis, T L; Husain, I

2014-02-01

There are thousands of medical applications for mobile devices targeting use by healthcare professionals. However, several factors related to the structure of the existing market for medical applications create significant barriers preventing practitioners from effectively identifying mobile medical applications for individual professional use. To define existing market factors relevant to selection of medical applications and describe a framework to empower clinicians to identify, assess and utilise mobile medical applications in their own practice. Resources available on the Internet regarding mobile medical applications, guidelines and published research on mobile medical applications. Mobile application stores (e.g. iTunes, Google Play) are not effective means of identifying mobile medical applications. Users of mobile devices that desire to implement mobile medical applications into practice need to carefully assess individual applications prior to utilisation. Searching and identifying mobile medical applications requires clinicians to utilise multiple references to determine what application is best for their individual practice methods. This can be done with a cursory exploration of mobile application stores and then moving onto other available resources published in the literature or through Internet resources (e.g. blogs, medical websites, social media). Clinicians must also take steps to ensure that an identified mobile application can be integrated into practice after carefully reviewing it themselves. Clinicians seeking to identify mobile medical application for use in their individual practice should use a combination of app stores, published literature, web-based resources, and personal review to ensure safe and appropriate use. © 2014 John Wiley & Sons Ltd.
HIV counselling and testing utilisation and attitudes of male inmates in a South African prison.

PubMed

Motshabi, Lelaka C; Pengpid, Supa; Peltzer, Karl

2011-01-01

The Department of Correctional Services Policy on the management of HIV and AIDS for offenders include voluntary counselling and testing (VCT) for HIV as one of the priorities in the rehabilitation of inmates. The aim of this study was to determine factors associated with the utilisation of VCT services in the correctional centres in terms of level of satisfaction, their experiences and expectations, and motivating factors and barriers for VCT utilisation at Losperfontein Correctional Centre, South Africa. This was a case control study (cases being those who underwent testing and controls those who did not) examining predictors of HIV VCT utilisation among 200 male adult sentenced inmates serving medium and maximum sentences. Results indicate that a poor health system (OR=0.34, 95%CI: 0.23 - 0.50) was inversely associated with HIV testing acceptance in prison, while age, educational level, population group, marital status, length of incarceration and access to HIV testing in prison were not associated with HIV testing acceptance in prison. Half of the participants (50%) agreed that VCT services are accessible and are promoted at their correctional centre. Most were satisfied with different components of VCT services, ranging from 79% (fair to very good) for 'the way he/she received you' to 62% 'clarified all your concerns'. This study demonstrated some challenges and benefits to the field of health promotion and HIV prevention in the correctional centres especially with regard to VCT services.
Utilisation of health services and geography: deconstructing regional differences in barriers to facility-based delivery in Nepal.

PubMed

Hodge, Andrew; Byrne, Abbey; Morgan, Alison; Jimenez-Soto, Eliana

2015-03-01

While established that geographical inaccessibility is a key barrier to the utilisation of health services, it remains unknown whether disparities are driven only by limited access to these services, or are also attributable to health behaviour. Significant disparities exist in health outcomes and the coverage of many critical health services between the mountains region of Nepal and the rest of the country, yet the principal factors driving these regional disparities are not well understood. Using national representative data from the 2011 Nepal Demographic and Health Survey, we examine the extent to which observable factors explain the overall differences in the utilisation of maternal health services. We apply nonlinear Blinder-Oaxaca-type decomposition methods to quantify the effect that differences in measurable characteristics have on the regional coverage gap in facility-based delivery. The mean coverage of facility-based deliveries was 18.6 and 36.3 % in the mountains region and the rest of Nepal, respectively. Between 54.8 and 74.1 % of the regional coverage gap was explained by differences in observed characteristics. Factors influencing health behaviours (proxied by mothers' education, TV viewership and tobacco use, and household wealth) and subjective distance to the health facility were the major factors, contributing between 52.9 and 62.5 % of the disparity. Mothers' birth history was also noteworthy. Policies simultaneously addressing access and health behaviours appear necessary to achieve greater coverage and better health outcomes for women and children in isolated areas.
Air-gating and chemical-gating in transistors and sensing devices made from hollow TiO2 semiconductor nanotubes

NASA Astrophysics Data System (ADS)

Alivov, Yahya; Funke, Hans; Nagpal, Prashant

2015-07-01

Rapid miniaturization of electronic devices down to the nanoscale, according to Moore’s law, has led to some undesirable effects like high leakage current in transistors, which can offset additional benefits from scaling down. Development of three-dimensional transistors, by spatial extension in the third dimension, has allowed higher contact area with a gate electrode and better control over conductivity in the semiconductor channel. However, these devices do not utilize the large surface area and interfaces for new electronic functionality. Here, we demonstrate air gating and chemical gating in hollow semiconductor nanotube devices and highlight the potential for development of novel transistors that can be modulated using channel bias, gate voltage, chemical composition, and concentration. Using chemical gating, we reversibly altered the conductivity of nanoscaled semiconductor nanotubes (10-500 nm TiO2 nanotubes) by six orders of magnitude, with a tunable rectification factor (ON/OFF ratio) ranging from 1-106. While demonstrated air- and chemical-gating speeds were slow here (˜seconds) due to the mechanical-evacuation rate and size of our chamber, the small nanoscale volume of these hollow semiconductors can enable much higher switching speeds, limited by the rate of adsorption/desorption of molecules at semiconductor interfaces. These chemical-gating effects are completely reversible, additive between different chemical compositions, and can enable semiconductor nanoelectronic devices for ‘chemical transistors’, ‘chemical diodes’, and very high-efficiency sensing applications.
Performance analysis of all-optical XOR gate with photonic crystal semiconductor optical amplifier-assisted Mach-Zehnder interferometer at 160 Gb/s

NASA Astrophysics Data System (ADS)

Kotb, Amer; Zoiros, Kyriakos E.

2017-11-01

The photonic crystal (PC) can be used to prohibit, confine, or control the propagation of light in a photonic band-gap. The performance of an ultrafast exclusive disjunction (XOR) gate-implemented with a photonic crystal semiconductor optical amplifier (PC-SOA)-assisted Mach-Zehnder interferometer (MZI) is numerically investigated and analyzed at a data rate of 160 Gb/s. The impact of the data signals and PC-SOA's critical parameters on the output quality factor (Q-factor) is examined and assessed. The simulation results demonstrate that the XOR gate which is based on the proposed scheme is capable of operating at the target data rate with logical correctness and high quality. This is achieved with better performance than when having conventional SOAs in the MZI, which justifies employing PC-SOAs as nonlinear elements.
Investigating the accessibility factors that influence antenatal care services utilisation in Mangwe district, Zimbabwe

PubMed Central

Tugli, Augustine K.; Mpofu, Molyn

2017-01-01

Background Maternal and infant mortality remains a huge public health problem in developing countries. One of the strategies to minimise the risks of both maternal and infant mortality is access to and utilisation of antenatal care (ANC) services. Aim This study aimed to investigate the accessibility factors that influence the use of ANC services in Mangwe district. Methods A qualitative approach using explorative design was adopted to target women who have babies under 1 year of age. The study was conducted in Mangwe district, Matabeleland South province, Zimbabwe. Data were collected through semi-structured interviews and observations. Data saturation was reached after 15 women who were conveniently sampled were interviewed. Field notes were analysed thematically using Tech’s steps. Lincoln and Guba’s criteria ensured trustworthiness of the study findings. Results Accessibility factors such as lack of transport, high transport costs and long distances to health care facilities, health care workers’ attitudes, type and quality of services as well as delays in receiving care influence women’s utilisation of ANC services in Mangwe district, Zimbabwe. Conclusion The study concluded that women were still facing problems of unavailability of nearby clinics; therefore, it was recommended that the government should avail resources for women to use. Recommendations Mangwe District Health Department should provide mobile clinics rendering ANC services in distant rural areas. PMID:28697619
A digital boxcar integrator for IMS spectra

NASA Technical Reports Server (NTRS)

Cohen, Martin J.; Stimac, Robert M.; Wernlund, Roger F.; Parker, Donald C.

1995-01-01

When trying to detect or quantify a signal at or near the limit of detectability, it is invariably embeded in the noise. This statement is true for nearly all detectors of any physical phenomena and the limit of detectability, hopefully, occurs at very low signal-to-noise levels. This is particularly true of IMS (Ion Mobility Spectrometers) spectra due to the low vapor pressure of several chemical compounds of great interest and the small currents associated with the ionic detection process. Gated Integrators and Boxcar Integrators or Averagers are designed to recover fast, repetitive analog signals. In a typical application, a time 'Gate' or 'Window' is generated, characterized by a set delay from a trigger or gate pulse and a certain width. A Gated Integrator amplifies and integrates the signal that is present during the time the gate is open, ignoring noise and interference that may be present at other times. Boxcar Integration refers to the practice of averaging the output of the Gated Integrator over many sweeps of the detector. Since any signal present during the gate will add linearly, while noise will add in a 'random walk' fashion as the square root of the number of sweeps, averaging N sweeps will improve the 'Signal-to-Noise Ratio' by a factor of the square root of N.

Characterization of high-dose and high-energy implanted gate and source diode and analysis of lateral spreading of p gate profile in high voltage SiC static induction transistors

NASA Astrophysics Data System (ADS)

Onose, Hidekatsu; Kobayashi, Yutaka; Onuki, Jin

2017-03-01

The effect of the p gate dose on the characteristics of the gate-source diode in SiC static induction transistors (SIT) was investigated. It was found that a dose of 1.5 × 1014 cm-2 yields a pn junction breakdown voltage higher than 60 V and good forward characteristics. A normally on SiC SIT was fabricated and demonstrated. A blocking voltage higher than 2.0 kV at a gate-source voltage of -50 V and on-resistance of 70 mΩ cm2 were obtained. Device simulations were performed to investigate the effect of the lateral spreading. By comparing the measured I-V curves with simulation results, the lateral spreading factor was estimated to be about 0.5. The lateral spreading detrimentally affected the electrical properties of the SIT made using implantations at energies higher than 1 MeV.
Health insurance determines antenatal, delivery and postnatal care utilisation: evidence from the Ghana Demographic and Health Surveillance data.

PubMed

Browne, Joyce L; Kayode, Gbenga A; Arhinful, Daniel; Fidder, Samuel A J; Grobbee, Diederick E; Klipstein-Grobusch, Kerstin

2016-03-18

This study aims to evaluate the effect of maternal health insurance status on the utilisation of antenatal, skilled delivery and postnatal care. A population-based cross-sectional study. We utilised the 2008 Demographic and Health Survey data of Ghana, which included 2987 women who provided information on maternal health insurance status. Utilisation of antenatal, skilled delivery and postnatal care. Multivariable logistic regression was applied to determine the independent association between maternal health insurance and utilisation of antenatal, skilled delivery and postnatal care. After adjusting for socioeconomic, demographic and obstetric factors, we observed that among insured women the likelihood of having antenatal care increased by 96% (OR 1.96; 95% CI 1.52 to 2.52; p value<0.001) and of skilled delivery by 129% (OR 2.29; 95% CI 1.92 to 2.74; p value<0.001), while postnatal care among insured women increased by 61% (OR 1.61; 95% CI 1.17 to 2.21; p value<0.01). This study demonstrated that maternal health insurance status plays a significant role in the uptake of the maternal, neonatal and child health continuum of care service. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Hospital admissions for severe mental illness in England: changes in equity of utilisation at the small area level between 2006 and 2010.

PubMed

White, Jonathan; Gutacker, Nils; Jacobs, Rowena; Mason, Anne

2014-11-01

Severe Mental Illness (SMI) encompasses a range of chronic conditions including schizophrenia, bipolar disorder and psychoses. Patients with SMI often require inpatient psychiatric care. Despite equity being a key objective in the English National Health Service (NHS) and in many other health care systems worldwide, little is known about the socio-economic equity of hospital care utilisation for patients with SMI and how it has changed over time. This analysis seeks to address that gap in the evidence base. We exploit a five-year (2006-2010) panel dataset of admission rates at small area level (n=162,410). The choice of control variables was informed by a systematic literature search. To assess changes in socio-economic equity of utilisation, OLS-based standardisation was first used to conduct analysis of discrete deprivation groups. Geographical inequity was then illustrated by plotting standardised and crude admission rates at local purchaser level. Lastly, formal statistical tests for changes in socio-economic equity of utilisation were applied to a continuous measure of deprivation using pooled negative binomial regression analysis, adjusting for a range of risk factors. Our results suggest that one additional percentage point of area income deprivation is associated with a 1.5% (p<0.001) increase in admissions for SMI after controlling for population size, age, sex, prevalence of SMI in the local population, as well as other need and supply factors. This finding is robust to sensitivity analyses, suggesting that a pro-poor inequality in utilisation exists for SMI-related inpatient services. One possible explanation is that the supply or quality of primary, community or social care for people with mental health problems is suboptimal in deprived areas. Although there is some evidence that inequity has reduced over time, the changes are small and not always robust to sensitivity analyses. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.
Permeable bio-reactive barriers to address petroleum hydrocarbon contamination at subantarctic Macquarie Island.

PubMed

Freidman, Benjamin L; Terry, Deborah; Wilkins, Dan; Spedding, Tim; Gras, Sally L; Snape, Ian; Stevens, Geoffrey W; Mumford, Kathryn A

2017-05-01

A reliance on diesel generated power and a history of imperfect fuel management have created a legacy of petroleum hydrocarbon contamination at subantarctic Macquarie Island. Increasing environmental awareness and advances in contaminant characterisation and remediation technology have fostered an impetus to reduce the environmental risk associated with legacy sites. A funnel and gate permeable bio-reactive barrier (PRB) was installed in 2014 to address the migration of Special Antarctic Blend diesel from a spill that occurred in 2002, as well as older spills and residual contaminants in the soil at the Main Power House. The PRB gate comprised of granular activated carbon and natural clinoptilolite zeolite. Petroleum hydrocarbons migrating in the soil water were successfully captured on the reactive materials, with concentrations at the outflow of the barrier recorded as being below reporting limits. The nutrient and iron concentrations delivered to the barrier demonstrated high temporal variability with significant iron precipitation observed across the bed. The surface of the granular activated carbon was largely free from cell attachment while natural zeolite demonstrated patchy biofilm formation after 15 months following PRB installation. This study illustrates the importance of informed material selection at field scale to ensure that adsorption and biodegradation processes are utilised to manage the environmental risk associated with petroleum hydrocarbon spills. This study reports the first installation of a permeable bio-reactive barrier in the subantarctic. Copyright © 2017 Elsevier Ltd. All rights reserved.
Acceptability Ratings of Language Interventions and Reasoning as Described by Early Childhood Special Education Teachers

ERIC Educational Resources Information Center

Turan, Yasemin

2012-01-01

This study utilised a structured analogue method to evaluate factors which impact preschool teachers' preference for language interventions. These factors included type of treatment approach (naturalistic versus therapeutic), person delivering the intervention (classroom teacher versus speech and language pathologist), and severity of language…
Impact of device engineering on analog/RF performances of tunnel field effect transistors

NASA Astrophysics Data System (ADS)

Vijayvargiya, V.; Reniwal, B. S.; Singh, P.; Vishvakarma, S. K.

2017-06-01

The tunnel field effect transistor (TFET) and its analog/RF performance is being aggressively studied at device architecture level for low power SoC design. Therefore, in this paper we have investigated the influence of the gate-drain underlap (UL) and different dielectric materials for the spacer and gate oxide on DG-TFET (double gate TFET) and its analog/RF performance for low power applications. Here, it is found that the drive current behavior in DG-TFET with a UL feature while implementing dielectric material for the spacer is different in comparison to that of DG-FET. Further, hetero gate dielectric-based DG-TFET (HGDG-TFET) is more resistive against drain-induced barrier lowering (DIBL) as compared to DG-TFET with high-k (HK) gate dielectric. Along with that, as compared to DG-FET, this paper also analyses the attributes of UL and dielectric material on analog/RF performance of DG-TFET in terms of transconductance (gm ), transconductance generation factor (TGF), capacitance, intrinsic resistance (Rdcr), cut-off frequency (F T), and maximum oscillation frequency (F max). The LK spacer-based HGDG-TFET with a gate-drain UL has the potential to improve the RF performance of device.
Integrating respiratory gating into a megavoltage cone-beam CT system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang Jenghwa; Sillanpaa, Jussi; Ling, Clifton C.

2006-07-15

We have previously described a low-dose megavoltage cone beam computed tomography (MV CBCT) system capable of producing projection image using one beam pulse. In this study, we report on its integration with respiratory gating for gated radiotherapy. The respiratory gating system tracks a reflective marker on the patient's abdomen midway between the xiphoid and umbilicus, and disables radiation delivery when the marker position is outside predefined thresholds. We investigate two strategies for acquiring gated scans. In the continuous rotation-gated acquisition, the linear accelerator (LINAC) is set to the fixed x-ray mode and the gantry makes a 5 min, 360 deg.continuousmore » rotation, during which the gating system turns the radiation beam on and off, resulting in projection images with an uneven distribution of projection angles (e.g., in 70 arcs each covering 2 deg.). In the gated rotation-continuous acquisition, the LINAC is set to the dynamic arc mode, which suspends the gantry rotation when the gating system inhibits the beam, leading to a slightly longer (6-7 min) scan time, but yielding projection images with more evenly distributed projection angles (e.g., {approx}0.8 deg.between two consecutive projection angles). We have tested both data acquisition schemes on stationary (a contrast detail and a thoracic) phantoms and protocol lung patients. For stationary phantoms, a separate motion phantom not visible in the images is used to trigger the RPM system. Frame rate is adjusted so that approximately 450 images (13 MU) are acquired for each scan and three-dimensional tomographic images reconstructed using a Feldkamp filtered backprojection algorithm. The gated rotation-continuous acquisition yield reconstructions free of breathing artifacts. The tumor in parenchymal lung and normal tissues are easily discernible and the boundary between the diaphragm and the lung sharply defined. Contrast-to-noise ratio (CNR) is not degraded relative to nongated scans of stationary phantoms. The continuous rotation-gated acquisition scan also yields tomographic images with discernible anatomic features; however, streak artifacts are observed and CNR is reduced by approximately a factor of 4. In conclusion, we have successfully developed a gated MV CBCT system to verify the patient positioning for gated radiotherapy.« less
How do people with dementia utilise primary care physicians and specialists within dementia networks? Results of the Dementia Networks in Germany (DemNet-D) study.

PubMed

Wübbeler, Markus; Thyrian, Jochen René; Michalowsky, Bernhard; Erdmann, Pia; Hertel, Johannes; Holle, Bernhard; Gräske, Johannes; Schäfer-Walkmann, Susanne; Hoffmann, Wolfgang

2017-01-01

Outpatient dementia healthcare is predominantly fragmented, and dementia networks (DNs) represent an integrated care concept to overcome this problem. Little is known about the patients of these networks with regard to utilisation of physicians and associated factors. We interviewed 560 caregivers of people with dementia in 13 different DNs in Germany in 2013 and assessed socio-demographics, clinical data and physician utilisation. Networks were categorised in predominantly medical DNs and community-oriented DNs. Descriptive and multivariate statistical models were used to identify associated factors between DNs and users' data. Overall, the users of networks received high rates of physician care; 93% of the sample stated at least one contact with a primary care physician within the last 6 months, and 74% had been treated by a specialist (neurology/psychiatry physician). Only 5% of the sample had no contact with a physician in the 6 months preceding the interview. Females showed a lower odds for physician specialist consultations (OR = 0.641). Users of medical DNs receive greater specialist consultations overall (OR = 8.370). Compared to the German general population and people with dementia in other settings, users of DNs receive physician care more regularly, especially with regard to the consultations of neurologist/psychiatrists. Therefore, DNs seem to perform a supportive role within the integration of physician healthcare. More research is needed on the appropriate relationship between the needs of the people with dementia and utilisation behaviour. © 2016 John Wiley & Sons Ltd.
Association between secure patient–clinician email and clinical services utilisation in a US integrated health system: a retrospective cohort study

PubMed Central

Meng, Di; Palen, Ted E; Tsai, Joanne; McLeod, Melanie; Garrido, Terhilda; Qian, Heather

2015-01-01

Objective To assess associations between secure patient–clinician email use and clinical services utilisation over time. Design Retrospective cohort study between July 2010 and December 2013. Controlling for a utilisation surge around first secure email use, we analysed difference of differences between propensity score-matched groups of secure patient–clinician email users and non-users for utilisation 1–12 months before and 7–18 months after first email (users) or a randomly assigned index date (non-users). Setting US integrated healthcare delivery system. Participants 9345 adults with first secure email use between July 2011 and July 2012 and continuous enrolment for ≥30 months and 9345 adults without secure email use between July 2010 and July 2012 matched to users on demographics, health status, and baseline utilisation. Primary Outcome Measures Rates of office visits, patient-initiated phone calls, scheduled telephone visits, after-hours clinic visits, emergency department visits, and hospitalisations. Results After controlling for multiple factors, no statistically significant differences in utilisation between secure email users and non-users occurred. Utilisation transiently increased by 88–237% around first email use. Annual rates of patient-initiated phone calls decreased among secure email users, 0.2 fewer calls per person (95% CI −0.3 to −0.1), from a mean of 4.1 calls per person 1–12 months before first use to a mean of 3.8 calls per person 7–18 months after first use. Rates of patient-initiated phone calls also decreased among non-users, 0.1 fewer calls per person (95% CI −0.2 to 0.0), from a mean of 4.2 calls per person 1–12 months before the index date to mean of 4.1 calls per person 7–18 months after the index date. Conclusions Compared with non-users, patient use of secure email with clinicians was not associated with statistically significant differences in clinical services utilisation 7–18 months after first use. PMID:26553841
Association between secure patient-clinician email and clinical services utilisation in a US integrated health system: a retrospective cohort study.

PubMed

Meng, Di; Palen, Ted E; Tsai, Joanne; McLeod, Melanie; Garrido, Terhilda; Qian, Heather

2015-11-09

To assess associations between secure patient-clinician email use and clinical services utilisation over time. Retrospective cohort study between July 2010 and December 2013. Controlling for a utilisation surge around first secure email use, we analysed difference of differences between propensity score-matched groups of secure patient-clinician email users and non-users for utilisation 1-12 months before and 7-18 months after first email (users) or a randomly assigned index date (non-users). US integrated healthcare delivery system. 9345 adults with first secure email use between July 2011 and July 2012 and continuous enrolment for ≥30 months and 9345 adults without secure email use between July 2010 and July 2012 matched to users on demographics, health status, and baseline utilisation. Rates of office visits, patient-initiated phone calls, scheduled telephone visits, after-hours clinic visits, emergency department visits, and hospitalisations. After controlling for multiple factors, no statistically significant differences in utilisation between secure email users and non-users occurred. Utilisation transiently increased by 88-237% around first email use. Annual rates of patient-initiated phone calls decreased among secure email users, 0.2 fewer calls per person (95% CI -0.3 to -0.1), from a mean of 4.1 calls per person 1-12 months before first use to a mean of 3.8 calls per person 7-18 months after first use. Rates of patient-initiated phone calls also decreased among non-users, 0.1 fewer calls per person (95% CI -0.2 to 0.0), from a mean of 4.2 calls per person 1-12 months before the index date to mean of 4.1 calls per person 7-18 months after the index date. Compared with non-users, patient use of secure email with clinicians was not associated with statistically significant differences in clinical services utilisation 7-18 months after first use. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Infant carrying methods: Correlates and associated musculoskeletal disorders among nursing mothers in Nigeria.

PubMed

Ojukwu, Chidiebele Petronilla; Anyanwu, Godson Emeka; Anekwu, Emelie Morris; Chukwu, Sylvester Caesar; Fab-Agbo, Chukwubuikem

2017-10-01

Infant carrying is an integral part of the mothering occupation. Paucity of data exists on its correlates and associated musculoskeletal injuries. In this study, factors and musculoskeletal injuries associated with infant carrying were investigated in 227 nursing mothers, using a structured questionnaire. 77.1% utilised the back infant carrying methods (ICM). Maternal comfort was the major factor influencing participants' (37.4%) choices of ICMs. Infant's age (p = .000) and transportation means (p = .045) were significantly associated with ICMs. Low back pain (82.8%) and upper back pain (74.9%) were the most reported musculoskeletal discomforts associated with ICMs, especially among women who utilised back ICM. Back ICM is predominantly used by nursing mothers. Impact statement Infant carrying has been associated with increased energy cost and biomechanical changes. Currently, there is a paucity of data on infant carrying-related musculoskeletal injuries. In this study, investigating factors and musculoskeletal injuries associated with infant carrying, the results showed that back infant carrying method is predominantly used by nursing mothers. Age of the infant and mothers' means of transportation were determinant factors of infant carrying methods. Among the several reported infant carrying-related musculoskeletal disorders, low back and upper back pain were the most prevalent, especially among women who utilised the back infant carrying method. There is need for women's health specialists to introduce appropriate ergonomic training and interventions on infant carrying tasks in order to improve maternal musculoskeletal health during the childbearing years and beyond. Further experimental studies on the effects of various infant carrying methods on the musculoskeletal system are recommended.
Factors Influencing the Selection of Speech Pathology as a Career: A Qualitative Analysis Utilising the Systems Theory Framework

ERIC Educational Resources Information Center

Byrne, Nicole

2007-01-01

Factors identified by 16 participants during in-depth interviews as influencing selection of speech pathology as a career were described using the Systems Theory Framework (STF, Patton & McMahon, 2006). Participants were highly likely to identify factors from the individual and social systems, but not the environmental-societal system, of the STF…
Systematic review of factors affecting pharmaceutical expenditures.

PubMed

Mousnad, Mohamed Awad; Shafie, Asrul Akmal; Ibrahim, Mohamed Izham

2014-06-01

To systematically identify the main factors contributing to the increase in pharmaceutical expenditures. A systematic search of published studies was conducted utilising major widely used electronic databases using the search terms 'factors,' 'financing,' 'pharmaceutical,' and 'expenditures.' To be included, the studies needed to: (1) measure at least one of the following outcomes: total growth in pharmaceutical expenditures, price growth or quantity growth; (2) mention a clear method for analysing the impact of factors affecting the increases in drug expenditures; (3) be written in English. Nonprimary articles that were published only as an abstract, a review, a commentary or a letter were excluded. From a total of 2039 studies, only 25 were included in the full review. The main determinant categories that were identified in the review were factors related to price, utilisation, therapeutic choice, demand and health care system. The major cost drivers were found to be changes in drug quantities and therapies as well as new drugs. It is important for policymakers to understand pharmaceutical spending trends and the factors that influence them in order to formulate effective cost containment strategies and design optimum drug policy. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Knowledge, attitude and practice of healthcare professionals towards infliximab and insulin glargine biosimilars: result of a UK web-based survey.

PubMed

Chapman, Stephen R; Fitzpatrick, Raymond W; Aladul, Mohammed I

2017-06-21

To investigate healthcare professionals' knowledge and attitudes towards infliximab and insulin glargine biosimilars and the factors influencing their prescribing. Then, to compare healthcare professionals' attitudes with the utilisation of these biosimilars in UK hospitals. Self-administered, one-time web-based survey and drug utilisation analysis. Professional associations and societies in the field of dermatology, diabetology, gastroenterology and rheumatology in the UK, between 8 August 2016 and 8 January 2017. The volume of utilisation of branded and biosimilar infliximab and insulin glargine in UK hospitals was derived from the DEFINE database, between 2015 and 2016. Participants' knowledge and awareness of biosimilars and factors influencing their use and corresponding usage of infliximab and insulin glargine biosimilars. Responses were obtained from 234 healthcare professionals across dermatology, diabetology, gastroenterology and rheumatology specialties. 75% of respondents were aware that biosimilars were available on their local formulary. 77% of respondents considered biosimilars extremely or very important to save costs for the NHS. Gastroenterologists had the highest utilisation of infliximab biosimilars (14%) in 2015 rising to (62%) in 2016. Healthcare professionals had greater concerns about safety and efficacy when switching patients to biosimilars than when starting biosimilars in biological naïve patients. Guidance from National Institute for Health and Care Excellence and robust pharmacovigilance studies on biosimilars were both considered important factors in increasing biosimilars use. British healthcare professionals are well informed about biosimilars with high level of awareness. Safety and efficacy concerns were higher in switching than in initiating biosimilars among some prescribers. It is probable that personal experience of biologics as well as discipline-specific guidance influenced prescribers' responses. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
A qualitative study exploring the determinants of maternal health service uptake in post-conflict Burundi and Northern Uganda.

PubMed

Chi, Primus Che; Bulage, Patience; Urdal, Henrik; Sundby, Johanne

2015-02-05

Armed conflict has been described as an important contributor to the social determinants of health and a driver of health inequity, including maternal health. These conflicts may severely reduce access to maternal health services and, as a consequence, lead to poor maternal health outcomes for a period extending beyond the conflict itself. As such, understanding how maternal health-seeking behaviour and utilisation of maternal health services can be improved in post-conflict societies is of crucial importance. This study aims to explore the determinants (barriers and facilitators) of women's uptake of maternal, sexual and reproductive health services (MSRHS) in two post-conflict settings in sub-Saharan Africa; Burundi and Northern Uganda, and how uptake is affected by exposure to armed conflict. This is a qualitative study that utilised in-depth interviews and focus group discussions (FGDs) for data collection. One hundred and fifteen participants took part in the interviews and FGDs across the two study settings. Participants were women of reproductive age, local health providers and staff of non-governmental organizations. Issues explored included the factors affecting women's utilisation of a range of MSRHS vis-à-vis conflict exposure. The framework method, making use of both inductive and deductive approaches, was used for analyzing the data. A complex and inter-related set of factors affect women's utilisation of MSRHS in post-conflict settings. Exposure to armed conflict affects women's utilisation of these services mainly through impeding women's health seeking behaviour and community perception of health services. The factors identified cut across the individual, socio-cultural, and political and health system spheres, and the main determinants include women's fear of developing pregnancy-related complications, status of women empowerment and support at the household and community levels, removal of user-fees, proximity to the health facility, and attitude of health providers. Improving women's uptake of MSRHS in post-conflict settings requires health system strengthening initiatives that address the barriers across the individual, socio-cultural, and political and health system spheres. While addressing financial barriers to access is crucial, attention should be paid to non-financial barriers as well. The goal should be to develop an equitable and sustainable health system.
Withstanding austerity: Equity in health services utilisation in the first stage of the economic recession in Southern Spain.

PubMed

Córdoba-Doña, Juan Antonio; Escolar-Pujolar, Antonio; San Sebastián, Miguel; Gustafsson, Per E

2018-01-01

Scant research is available on the impact of the current economic crisis and austerity policies on inequality in health services utilisation in Europe. This study aimed to describe the trends in horizontal inequity in the use of health services in Andalusia, Spain, during the early years of the Great Recession, and the contribution of demographic, economic and social factors. Consultation with a general practitioner (GP) and specialist, hospitalisation and emergency care were studied through the Andalusian Health Survey 2007 (pre-crisis) and 2011-2012 (crisis), using a composite income index as socioeconomic status (SES) indicator. Horizontal inequity indices (HII) were calculated to take differential healthcare needs into account, and a decomposition analysis of change in inequality between periods was performed. Results showed that before the crisis, the HII was positive (greater access for people with higher SES) for specialist visits but negative (greater access for people with lower SES) in the other three utilisation models. During the crisis no change was observed in inequalities in GP visits, but a pro-poor development was seen for the other types of utilisation, with hospital and emergency care showing significant inequality in favour of low income groups. Overall, the main contributors to pro-poor changes in utilisation were socio-economic variables and poor mental health, due to changes in their elasticities. Our findings show that inequalities in healthcare utilisation largely remained in favour of the less well-off, despite the cuts in welfare benefits and health services provision during the early years of the recession in Andalusia. Further research is needed to monitor the potential impact of such measures in subsequent years.
Withstanding austerity: Equity in health services utilisation in the first stage of the economic recession in Southern Spain

PubMed Central

2018-01-01

Scant research is available on the impact of the current economic crisis and austerity policies on inequality in health services utilisation in Europe. This study aimed to describe the trends in horizontal inequity in the use of health services in Andalusia, Spain, during the early years of the Great Recession, and the contribution of demographic, economic and social factors. Consultation with a general practitioner (GP) and specialist, hospitalisation and emergency care were studied through the Andalusian Health Survey 2007 (pre-crisis) and 2011–2012 (crisis), using a composite income index as socioeconomic status (SES) indicator. Horizontal inequity indices (HII) were calculated to take differential healthcare needs into account, and a decomposition analysis of change in inequality between periods was performed. Results showed that before the crisis, the HII was positive (greater access for people with higher SES) for specialist visits but negative (greater access for people with lower SES) in the other three utilisation models. During the crisis no change was observed in inequalities in GP visits, but a pro-poor development was seen for the other types of utilisation, with hospital and emergency care showing significant inequality in favour of low income groups. Overall, the main contributors to pro-poor changes in utilisation were socio-economic variables and poor mental health, due to changes in their elasticities. Our findings show that inequalities in healthcare utilisation largely remained in favour of the less well-off, despite the cuts in welfare benefits and health services provision during the early years of the recession in Andalusia. Further research is needed to monitor the potential impact of such measures in subsequent years. PMID:29601609
Ion-gel-gating-induced oxygen vacancy formation in epitaxial L a0.5S r0.5Co O3 -δ films from in operando x-ray and neutron scattering

NASA Astrophysics Data System (ADS)

Walter, Jeff; Yu, Guichuan; Yu, Biqiong; Grutter, Alexander; Kirby, Brian; Borchers, Julie; Zhang, Zhan; Zhou, Hua; Birol, Turan; Greven, Martin; Leighton, Chris

2017-12-01

Ionic-liquid/gel-based transistors have emerged as a potentially ideal means to accumulate high charge-carrier densities at the surfaces of materials such as oxides, enabling control over electronic phase transitions. Substantial gaps remain in the understanding of gating mechanisms, however, particularly with respect to charge carrier vs oxygen defect creation, one contributing factor being the dearth of experimental probes beyond electronic transport. Here we demonstrate the use of synchrotron hard x-ray diffraction and polarized neutron reflectometry as in operando probes of ion-gel transistors based on ferromagnetic L a0.5S r0.5Co O3 -δ . An asymmetric gate-bias response is confirmed to derive from electrostatic hole accumulation at negative gate bias vs oxygen vacancy formation at positive bias. The latter is detected via a large gate-induced lattice expansion (up to 1%), complementary bulk measurements and density functional calculations enabling quantification of the bias-dependent oxygen vacancy density. Remarkably, the gate-induced oxygen vacancies proliferate through the entire thickness of 30-40-unit-cell-thick films, quantitatively accounting for changes in the magnetization depth profile. These results directly elucidate the issue of electrostatic vs redox-based response in electrolyte-gated oxides, also demonstrating powerful approaches to their in operando investigation.
The human respiratory gate

NASA Technical Reports Server (NTRS)

Eckberg, Dwain L.

2003-01-01

Respiratory activity phasically alters membrane potentials of preganglionic vagal and sympathetic motoneurones and continuously modulates their responsiveness to stimulatory inputs. The most obvious manifestation of this 'respiratory gating' is respiratory sinus arrhythmia, the rhythmic fluctuations of electrocardiographic R-R intervals observed in healthy resting humans. Phasic autonomic motoneurone firing, reflecting the throughput of the system, depends importantly on the intensity of stimulatory inputs, such that when levels of stimulation are low (as with high arterial pressure and sympathetic activity, or low arterial pressure and vagal activity), respiratory fluctuations of sympathetic or vagal firing are also low. The respiratory gate has a finite capacity, and high levels of stimulation override the ability of respiration to gate autonomic responsiveness. Autonomic throughput also depends importantly on other factors, including especially, the frequency of breathing, the rate at which the gate opens and closes. Respiratory sinus arrhythmia is small at rapid, and large at slow breathing rates. The strong correlation between systolic pressure and R-R intervals at respiratory frequencies reflects the influence of respiration on these two measures, rather than arterial baroreflex physiology. A wide range of evidence suggests that respiratory activity gates the timing of autonomic motoneurone firing, but does not influence its tonic level. I propose that the most enduring significance of respiratory gating is its use as a precisely controlled experimental tool to tease out and better understand otherwise inaccessible human autonomic neurophysiological mechanisms.
Genetic programs constructed from layered logic gates in single cells

PubMed Central

Moon, Tae Seok; Lou, Chunbo; Tamsir, Alvin; Stanton, Brynne C.; Voigt, Christopher A.

2014-01-01

Genetic programs function to integrate environmental sensors, implement signal processing algorithms and control expression dynamics1. These programs consist of integrated genetic circuits that individually implement operations ranging from digital logic to dynamic circuits2–6, and they have been used in various cellular engineering applications, including the implementation of process control in metabolic networks and the coordination of spatial differentiation in artificial tissues. A key limitation is that the circuits are based on biochemical interactions occurring in the confined volume of the cell, so the size of programs has been limited to a few circuits1,7. Here we apply part mining and directed evolution to build a set of transcriptional AND gates in Escherichia coli. Each AND gate integrates two promoter inputs and controls one promoter output. This allows the gates to be layered by having the output promoter of an upstream circuit serve as the input promoter for a downstream circuit. Each gate consists of a transcription factor that requires a second chaperone protein to activate the output promoter. Multiple activator–chaperone pairs are identified from type III secretion pathways in different strains of bacteria. Directed evolution is applied to increase the dynamic range and orthogonality of the circuits. These gates are connected in different permutations to form programs, the largest of which is a 4-input AND gate that consists of 3 circuits that integrate 4 inducible systems, thus requiring 11 regulatory proteins. Measuring the performance of individual gates is sufficient to capture the behaviour of the complete program. Errors in the output due to delays (faults), a common problem for layered circuits, are not observed. This work demonstrates the successful layering of orthogonal logic gates, a design strategy that could enable the construction of large, integrated circuits in single cells. PMID:23041931

Investigation of the novel attributes in double recessed gate SiC MESFETs at drain side

NASA Astrophysics Data System (ADS)

Orouji, Ali A.; Razavi, S. M.; Ebrahim Hosseini, Seyed; Amini Moghadam, Hamid

2011-11-01

In this paper, the potential impact of drain side-double recessed gate (DS-DRG) on silicon carbide (SiC)-based metal semiconductor field effect transistors (MESFETs) is studied. We investigate the device performance focusing on breakdown voltage, threshold voltage, drain current and dc output conductance with two-dimensional and two-carrier device simulation. Our simulation results demonstrate that the channel thickness under the gate in the drain side is an important factor in the breakdown voltage. Also, the positive shift in the threshold voltage for the DS-DRG structure is larger in comparison with that for the source side-double recessed gate (SS-DRG) SiC MESFET. The saturated drain current for the DS-DRG structure is larger compared to that for the SS-DRG structure. The maximum dc output conductance in the DS-DRG structure is smaller than that in the SS-DRG structure.
Trap-mediated electronic transport properties of gate-tunable pentacene/MoS2 p-n heterojunction diodes

PubMed Central

Kim, Jae-Keun; Cho, Kyungjune; Kim, Tae-Young; Pak, Jinsu; Jang, Jingon; Song, Younggul; Kim, Youngrok; Choi, Barbara Yuri; Chung, Seungjun; Hong, Woong-Ki; Lee, Takhee

2016-01-01

We investigated the trap-mediated electronic transport properties of pentacene/molybdenum disulphide (MoS2) p-n heterojunction devices. We observed that the hybrid p-n heterojunctions were gate-tunable and were strongly affected by trap-assisted tunnelling through the van der Waals gap at the heterojunction interfaces between MoS2 and pentacene. The pentacene/MoS2 p-n heterojunction diodes had gate-tunable high ideality factor, which resulted from trap-mediated conduction nature of devices. From the temperature-variable current-voltage measurement, a space-charge-limited conduction and a variable range hopping conduction at a low temperature were suggested as the gate-tunable charge transport characteristics of these hybrid p-n heterojunctions. Our study provides a better understanding of the trap-mediated electronic transport properties in organic/2-dimensional material hybrid heterojunction devices. PMID:27829663
Trap-mediated electronic transport properties of gate-tunable pentacene/MoS2 p-n heterojunction diodes

NASA Astrophysics Data System (ADS)

Kim, Jae-Keun; Cho, Kyungjune; Kim, Tae-Young; Pak, Jinsu; Jang, Jingon; Song, Younggul; Kim, Youngrok; Choi, Barbara Yuri; Chung, Seungjun; Hong, Woong-Ki; Lee, Takhee

2016-11-01

We investigated the trap-mediated electronic transport properties of pentacene/molybdenum disulphide (MoS2) p-n heterojunction devices. We observed that the hybrid p-n heterojunctions were gate-tunable and were strongly affected by trap-assisted tunnelling through the van der Waals gap at the heterojunction interfaces between MoS2 and pentacene. The pentacene/MoS2 p-n heterojunction diodes had gate-tunable high ideality factor, which resulted from trap-mediated conduction nature of devices. From the temperature-variable current-voltage measurement, a space-charge-limited conduction and a variable range hopping conduction at a low temperature were suggested as the gate-tunable charge transport characteristics of these hybrid p-n heterojunctions. Our study provides a better understanding of the trap-mediated electronic transport properties in organic/2-dimensional material hybrid heterojunction devices.
Trap-mediated electronic transport properties of gate-tunable pentacene/MoS2 p-n heterojunction diodes.

PubMed

Kim, Jae-Keun; Cho, Kyungjune; Kim, Tae-Young; Pak, Jinsu; Jang, Jingon; Song, Younggul; Kim, Youngrok; Choi, Barbara Yuri; Chung, Seungjun; Hong, Woong-Ki; Lee, Takhee

2016-11-10

We investigated the trap-mediated electronic transport properties of pentacene/molybdenum disulphide (MoS 2 ) p-n heterojunction devices. We observed that the hybrid p-n heterojunctions were gate-tunable and were strongly affected by trap-assisted tunnelling through the van der Waals gap at the heterojunction interfaces between MoS 2 and pentacene. The pentacene/MoS 2 p-n heterojunction diodes had gate-tunable high ideality factor, which resulted from trap-mediated conduction nature of devices. From the temperature-variable current-voltage measurement, a space-charge-limited conduction and a variable range hopping conduction at a low temperature were suggested as the gate-tunable charge transport characteristics of these hybrid p-n heterojunctions. Our study provides a better understanding of the trap-mediated electronic transport properties in organic/2-dimensional material hybrid heterojunction devices.
Influencing Factors of Female Underrepresentation as School Principals in Indonesia

ERIC Educational Resources Information Center

Airin, Rashidah

2010-01-01

Purpose -- Number of women in the school principalship in Indonesia is less than half of the males'. This paper aims to identify the factor behind the underrepresentation of women in the principalship. Design/methodology/approach -- The methodological approach utilised in this paper was a structured review of the literature. Twenty sources namely…
A systematic review of factors influencing knowledge management and the nurse leaders' role.

PubMed

Lunden, Anne; Teräs, Marianne; Kvist, Tarja; Häggman-Laitila, Arja

2017-09-01

To describe factors facilitating or inhibiting the development of registered nurses' competency and nurse leader's role in knowledge management. Nurses' competency directly influences patient safety and the quality and effectiveness of patient care. Challenges of nurse leaders in knowledge management include acquiring, assessing and utilising current knowledge and assessing and enhancing competency. A systematic search was conducted in PubMed, CINAHL, SCOPUS and ERIC databases in April 2015. The search identified 18 relevant research articles published between 2009 and 2015. The quality of the studies was appraised in accordance with study designs. Knowledge management is facilitated by an organisation culture that supports learning, sharing of information and learning together. Leader commitment and competency were factors related to leadership facilitating knowledge management. Nurse leaders need evidence-based interventions to support shared learning and to create infrastructures that facilitate competence development. Future research is especially needed to evaluate connections between knowledge management and patient outcomes. The results of this review can be utilised in enhancing factors to facilitate knowledge management in clinical practice and identifying nurse leaders' role in strengthening nurses' competency. © 2017 John Wiley & Sons Ltd.
Identifying patterns of general practitioner service utilisation and their relationship with potentially preventable hospitalisations in people with diabetes: The utility of a cluster analysis approach.

PubMed

Ha, Ninh Thi; Harris, Mark; Preen, David; Robinson, Suzanne; Moorin, Rachael

2018-04-01

We aimed to characterise use of general practitioners (GP) simultaneously across multiple attributes in people with diabetes and examine its impact on diabetes related potentially preventable hospitalisations (PPHs). Five-years of panel data from 40,625 adults with diabetes were sourced from Western Australian administrative health records. Cluster analysis (CA) was used to group individuals with similar patterns of GP utilisation characterised by frequency and recency of services. The relationship between GP utilisation cluster and the risk of PPHs was examined using multivariable random-effects negative binomial regression. CA categorised GP utilisation into three clusters: moderate; high and very high usage, having distinct patient characteristics. After adjusting for potential confounders, the rate of PPHs was significantly lower across all GP usage clusters compared with those with no GP usage; IRR = 0.67 (95%CI: 0.62-0.71) among the moderate, IRR = 0.70 (95%CI 0.66-0.73) high and IRR = 0.76 (95%CI 0.72-0.80) very high GP usage clusters. Combination of temporal factors with measures of frequency of use of GP services revealed patterns of primary health care utilisation associated with different underlying patient characteristics. Incorporation of multiple attributes, that go beyond frequency-based approaches may better characterise the complex relationship between use of GP services and diabetes-related hospitalisation. Copyright © 2018 Elsevier B.V. All rights reserved.
Porous Emitter Colloid Thruster Performance Characterization Using Optical Techniques

DTIC Science & Technology

2013-03-01

spacecraft. Liquid propellant has received a renewed interest as a viable propellant with the creation and proliferation of new ionic liquid compounds ...electrostatic gate) and collector (metallic plate) is unknown. Two factors cause this ambiguity, first, the gate needs to close fast enough to...simultaneously block all of the emitters and second, it is not directly known which emitter released the last particle hitting the collector plate
Developing Point-of-Decision Prompts to Encourage Airport Walking: The Walk to Fly Study.

PubMed

Frederick, Ginny M; Paul, Prabasaj; Bachtel Watson, Kathleen; Dorn, Joan M; Fulton, Janet

2016-04-01

Point-of-decision prompts may be appropriate to promote walking, instead of using a mechanized mode of transport, such as a train, in airports. To our knowledge, no current studies describe the development of messages for prompts in this setting. In-person interviews were conducted with 150 randomly selected airport travelers who rode the train to their departure gate. Travelers reported various reasons for riding the train to their gate. They were asked about messages that would encourage them to walk. Exploratory factor analysis was conducted for reasons for riding the train. Confirmatory factor analysis was conducted for messages to encourage walking to the departure gate. Travelers reported not knowing walking was an option (23.8%), seeing others riding the train (14.4%), and being afraid of getting lost (9.2%) as reasons for riding the train. Many indicated that directional signs and prompts promoting walking as exercise would encourage them to walk instead of riding the train. Some reasons for riding the train in an airport may be modifiable by installing point-of-decision prompts. Providing directional signs to travelers may prompt them to walk to their gate instead of riding the train. Similar prompts may also be considered in other community settings.
Developing Point-of-Decision Prompts to Encourage Airport Walking: The Walk to Fly Study

PubMed Central

Frederick, Ginny M.; Paul, Prabasaj; Watson, Kathleen Bachtel; Dorn, Joan M.; Fulton, Janet

2017-01-01

Background Point-of-decision prompts may be appropriate to promote walking, instead of using a mechanized mode of transport, such as a train, in airports. To our knowledge, no current studies describe the development of messages for prompts in this setting. Methods In-person interviews were conducted with 150 randomly selected airport travelers who rode the train to their departure gate. Travelers reported various reasons for riding the train to their gate. They were asked about messages that would encourage them to walk. Exploratory factor analysis was conducted for reasons for riding the train. Confirmatory factor analysis was conducted for messages to encourage walking to the departure gate. Results Travelers reported not knowing walking was an option (23.8%), seeing others riding the train (14.4%), and being afraid of getting lost (9.2%) as reasons for riding the train. Many indicated that directional signs and prompts promoting walking as exercise would encourage them to walk instead of riding the train. Conclusions Some reasons for riding the train in an airport may be modifiable by installing point-of-decision prompts. Providing directional signs to travelers may prompt them to walk to their gate instead of riding the train. Similar prompts may also be considered in other community settings. PMID:26445371
ResearchGate is no longer reliable: leniency towards ghost journals may decrease its impact on the scientific community.

PubMed

Memon, Aamir Raoof

2016-12-01

ResearchGate has been regarded as one of the most attractive academic social networking site for scientific community. It has been trying to improve user-centered interfaces to gain more attractiveness to scientists around the world. Display of journal related scietometric measures (such as impact factor, 5-year impact, cited half-life, eigenfactor) is an important feature in ResearchGate. Open access publishing has added more to increased visibility of research work and easy access to information related to research. Moreover, scientific community has been much interested in promoting their work and exhibiting its impact to others through reliable scientometric measures. However, with the growing market of publications and improvements in the field of research, this community has been victimized by the cybercrime in the form of ghost journals, fake publishers and magical impact measures. Particularly, ResearchGate more recently, has been lenient in its policies against this dark side of academic writing. Therefore, this communication aims to discuss concerns associated with leniency in ResearchGate policies and its impact of scientific community.
Intellectual Disability and Assistive Technology: Opening the GATE Wider.

PubMed

Boot, Fleur Heleen; Dinsmore, John; Khasnabis, Chapal; MacLachlan, Malcolm

2017-01-01

The World Health Organization has launched a program to promote Global Cooperation on Assistive Technology (GATE). The objective of the GATE program is to improve access to high quality, affordable assistive technology for people with varying disabilities, diseases, and age-related conditions. As a first step, GATE has developed the assistive products list, a list of priority assistive products based on addressing the greatest need at population level. A specific group of people who can benefit from user appropriate assistive technology are people with intellectual disabilities. However, the use of assistive products by people with intellectual disabilities is a neglected area of research and practice, and offers considerable opportunities for the advancement of population health and the realization of basic human rights. It is unknown how many people with intellectual disabilities globally have access to appropriate assistive products and which factors influence their access. We call for a much greater focus on people with intellectual disabilities within the GATE program. We present a framework for understanding the complex interaction between intellectual disability, health and wellbeing, and assistive technology.
Gating the holes in the Swiss cheese (part I): Expanding professor Reason's model for patient safety.

PubMed

Seshia, Shashi S; Bryan Young, G; Makhinson, Michael; Smith, Preston A; Stobart, Kent; Croskerry, Pat

2018-02-01

Although patient safety has improved steadily, harm remains a substantial global challenge. Additionally, safety needs to be ensured not only in hospitals but also across the continuum of care. Better understanding of the complex cognitive factors influencing health care-related decisions and organizational cultures could lead to more rational approaches, and thereby to further improvement. A model integrating the concepts underlying Reason's Swiss cheese theory and the cognitive-affective biases plus cascade could advance the understanding of cognitive-affective processes that underlie decisions and organizational cultures across the continuum of care. Thematic analysis, qualitative information from several sources being used to support argumentation. Complex covert cognitive phenomena underlie decisions influencing health care. In the integrated model, the Swiss cheese slices represent dynamic cognitive-affective (mental) gates: Reason's successive layers of defence. Like firewalls and antivirus programs, cognitive-affective gates normally allow the passage of rational decisions but block or counter unsounds ones. Gates can be breached (ie, holes created) at one or more levels of organizations, teams, and individuals, by (1) any element of cognitive-affective biases plus (conflicts of interest and cognitive biases being the best studied) and (2) other potential error-provoking factors. Conversely, flawed decisions can be blocked and consequences minimized; for example, by addressing cognitive biases plus and error-provoking factors, and being constantly mindful. Informed shared decision making is a neglected but critical layer of defence (cognitive-affective gate). The integrated model can be custom tailored to specific situations, and the underlying principles applied to all methods for improving safety. The model may also provide a framework for developing and evaluating strategies to optimize organizational cultures and decisions. The concept is abstract, the model is virtual, and the best supportive evidence is qualitative and indirect. The proposed model may help enhance rational decision making across the continuum of care, thereby improving patient safety globally. © 2017 The Authors. Journal of Evaluation in Clinical Practice published by John Wiley & Sons, Ltd.
Gating the holes in the Swiss cheese (part I): Expanding professor Reason's model for patient safety

PubMed Central

Bryan Young, G.; Makhinson, Michael; Smith, Preston A.; Stobart, Kent; Croskerry, Pat

2017-01-01

Abstract Introduction Although patient safety has improved steadily, harm remains a substantial global challenge. Additionally, safety needs to be ensured not only in hospitals but also across the continuum of care. Better understanding of the complex cognitive factors influencing health care–related decisions and organizational cultures could lead to more rational approaches, and thereby to further improvement. Hypothesis A model integrating the concepts underlying Reason's Swiss cheese theory and the cognitive‐affective biases plus cascade could advance the understanding of cognitive‐affective processes that underlie decisions and organizational cultures across the continuum of care. Methods Thematic analysis, qualitative information from several sources being used to support argumentation. Discussion Complex covert cognitive phenomena underlie decisions influencing health care. In the integrated model, the Swiss cheese slices represent dynamic cognitive‐affective (mental) gates: Reason's successive layers of defence. Like firewalls and antivirus programs, cognitive‐affective gates normally allow the passage of rational decisions but block or counter unsounds ones. Gates can be breached (ie, holes created) at one or more levels of organizations, teams, and individuals, by (1) any element of cognitive‐affective biases plus (conflicts of interest and cognitive biases being the best studied) and (2) other potential error‐provoking factors. Conversely, flawed decisions can be blocked and consequences minimized; for example, by addressing cognitive biases plus and error‐provoking factors, and being constantly mindful. Informed shared decision making is a neglected but critical layer of defence (cognitive‐affective gate). The integrated model can be custom tailored to specific situations, and the underlying principles applied to all methods for improving safety. The model may also provide a framework for developing and evaluating strategies to optimize organizational cultures and decisions. Limitations The concept is abstract, the model is virtual, and the best supportive evidence is qualitative and indirect. Conclusions The proposed model may help enhance rational decision making across the continuum of care, thereby improving patient safety globally. PMID:29168290
A magnetoelectric flux gate: new approach for weak DC magnetic field detection.

PubMed

Chu, Zhaoqiang; Shi, Huaduo; PourhosseiniAsl, Mohammad Javad; Wu, Jingen; Shi, Weiliang; Gao, Xiangyu; Yuan, Xiaoting; Dong, Shuxiang

2017-08-17

The magnetic flux gate sensors based on Faraday's Law of Induction are widely used for DC or extremely low frequency magnetic field detection. Recently, as the fast development of multiferroics and magnetoelectric (ME) composite materials, a new technology based on ME coupling effect is emerging for potential devices application. Here, we report a magnetoelectric flux gate sensor (MEFGS) for weak DC magnetic field detection for the first time, which works on a similar magnetic flux gate principle, but based on ME coupling effect. The proposed MEFGS has a shuttle-shaped configuration made of amorphous FeBSi alloy (Metglas) serving as both magnetic and magnetostrictive cores for producing a closed-loop high-frequency magnetic flux and also a longitudinal vibration, and one pair of embedded piezoelectric PMN-PT fibers ([011]-oriented Pb(Mg,Nb)O 3 -PbTiO 3 single crystal) serving as ME flux gate in a differential mode for detecting magnetic anomaly. In this way, the relative change in output signal of the MEFGS under an applied DC magnetic anomaly of 1 nT was greatly enhanced by a factor of 4 to 5 in comparison with the previous reports. The proposed ME flux gate shows a great potential for magnetic anomaly detections, such as magnetic navigation, magnetic based medical diagnosis, etc.
The impact of conservation-driven translocations on blood parasite prevalence in the Seychelles warbler.

PubMed

Fairfield, Eleanor A; Hutchings, Kimberly; Gilroy, Danielle L; Kingma, Sjouke A; Burke, Terry; Komdeur, Jan; Richardson, David S

2016-07-13

Introduced populations often lose the parasites they carried in their native range, but little is known about which processes may cause parasite loss during host movement. Conservation-driven translocations could provide an opportunity to identify the mechanisms involved. Using 3,888 blood samples collected over 22 years, we investigated parasite prevalence in populations of Seychelles warblers (Acrocephalus sechellensis) after individuals were translocated from Cousin Island to four new islands (Aride, Cousine, Denis and Frégate). Only a single parasite (Haemoproteus nucleocondensus) was detected on Cousin (prevalence = 52%). This parasite persisted on Cousine (prevalence = 41%), but no infection was found in individuals hatched on Aride, Denis or Frégate. It is not known whether the parasite ever arrived on Aride, but it has not been detected there despite 20 years of post-translocation sampling. We confirmed that individuals translocated to Denis and Frégate were infected, with initial prevalence similar to Cousin. Over time, prevalence decreased on Denis and Frégate until the parasite was not found on Denis two years after translocation, and was approaching zero prevalence on Frégate. The loss (Denis) or decline (Frégate) of H. nucleocondensus, despite successful establishment of infected hosts, must be due to factors affecting parasite transmission on these islands.
The impact of conservation-driven translocations on blood parasite prevalence in the Seychelles warbler

PubMed Central

Fairfield, Eleanor A.; Hutchings, Kimberly; Gilroy, Danielle L.; Kingma, Sjouke A.; Burke, Terry; Komdeur, Jan; Richardson, David S.

2016-01-01

Introduced populations often lose the parasites they carried in their native range, but little is known about which processes may cause parasite loss during host movement. Conservation-driven translocations could provide an opportunity to identify the mechanisms involved. Using 3,888 blood samples collected over 22 years, we investigated parasite prevalence in populations of Seychelles warblers (Acrocephalus sechellensis) after individuals were translocated from Cousin Island to four new islands (Aride, Cousine, Denis and Frégate). Only a single parasite (Haemoproteus nucleocondensus) was detected on Cousin (prevalence = 52%). This parasite persisted on Cousine (prevalence = 41%), but no infection was found in individuals hatched on Aride, Denis or Frégate. It is not known whether the parasite ever arrived on Aride, but it has not been detected there despite 20 years of post-translocation sampling. We confirmed that individuals translocated to Denis and Frégate were infected, with initial prevalence similar to Cousin. Over time, prevalence decreased on Denis and Frégate until the parasite was not found on Denis two years after translocation, and was approaching zero prevalence on Frégate. The loss (Denis) or decline (Frégate) of H. nucleocondensus, despite successful establishment of infected hosts, must be due to factors affecting parasite transmission on these islands. PMID:27405249
Influence of target reflection on three-dimensional range gated reconstruction.

PubMed

Chua, Sing Yee; Wang, Xin; Guo, Ningqun; Tan, Ching Seong

2016-08-20

The range gated technique is a promising laser ranging method that is widely used in different fields such as surveillance, industry, and military. In a range gated system, a reflected laser pulse returned from the target scene contains key information for range reconstruction, which directly affects the system performance. Therefore, it is necessary to study the characteristics and effects of the target reflection factor. In this paper, theoretical and experimental analyses are performed to investigate the influence of target reflection on three-dimensional (3D) range gated reconstruction. Based on laser detection and ranging (LADAR) and bidirectional reflection distribution function (BRDF) theory, a 3D range gated reconstruction model is derived and the effect on range accuracy is analyzed from the perspectives of target surface reflectivity and angle of laser incidence. Our theoretical and experimental study shows that the range accuracy is proportional to the target surface reflectivity, but it decreases when the angle of incidence increases to adhere to the BRDF model. The presented findings establish a comprehensive understanding of target reflection in 3D range gated reconstruction, which is of interest to various applications such as target recognition and object modeling. This paper provides a reference for future improvement to perform accurate range compensation or correction.
Orientation selectivity in a multi-gated organic electrochemical transistor

NASA Astrophysics Data System (ADS)

Gkoupidenis, Paschalis; Koutsouras, Dimitrios A.; Lonjaret, Thomas; Fairfield, Jessamyn A.; Malliaras, George G.

2016-06-01

Neuromorphic devices offer promising computational paradigms that transcend the limitations of conventional technologies. A prominent example, inspired by the workings of the brain, is spatiotemporal information processing. Here we demonstrate orientation selectivity, a spatiotemporal processing function of the visual cortex, using a poly(3,4ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) organic electrochemical transistor with multiple gates. Spatially distributed inputs on a gate electrode array are found to correlate with the output of the transistor, leading to the ability to discriminate between different stimuli orientations. The demonstration of spatiotemporal processing in an organic electronic device paves the way for neuromorphic devices with new form factors and a facile interface with biology.
The Feynman-Y Statistic in Relation to Shift-Register Neutron Coincidence Counting: Precision and Dead Time

DOE Office of Scientific and Technical Information (OSTI.GOV)

Croft, Stephen; Santi, Peter A.; Henzlova, Daniela

The Feynman-Y statistic is a type of autocorrelation analysis. It is defined as the excess variance-to-mean ratio, Y = VMR - 1, of the number count distribution formed by sampling a pulse train using a series of non-overlapping gates. It is a measure of the degree of correlation present on the pulse train with Y = 0 for Poisson data. In the context of neutron coincidence counting we show that the same information can be obtained from the accidentals histogram acquired using the multiplicity shift-register method, which is currently the common autocorrelation technique applied in nuclear safeguards. In the casemore » of multiplicity shift register analysis however, overlapping gates, either triggered by the incoming pulse stream or by a periodic clock, are used. The overlap introduces additional covariance but does not alter the expectation values. In this paper we discuss, for a particular data set, the relative merit of the Feynman and shift-register methods in terms of both precision and dead time correction. Traditionally the Feynman approach is applied with a relatively long gate width compared to the dieaway time. The main reason for this is so that the gate utilization factor can be taken as unity rather than being treated as a system parameter to be determined at characterization/calibration. But because the random trigger interval gate utilization factor is slow to saturate this procedure requires a gate width many times the effective 1/e dieaway time. In the traditional approach this limits the number of gates that can be fitted into a given assay duration. We empirically show that much shorter gates, similar in width to those used in traditional shift register analysis can be used. Because the way in which the correlated information present on the pulse train is extracted is different for the moments based method of Feynman and the various shift register based approaches, the dead time losses are manifested differently for these two approaches. The resulting estimates for the dead time corrected first and second order reduced factorial moments should be independent of the method however and this allows the respective dead time formalism to be checked. We discuss how to make dead time corrections in both the shift register and the Feynman approaches.« less

Two-electron spin correlations in precision placed donors in silicon.

PubMed

Broome, M A; Gorman, S K; House, M G; Hile, S J; Keizer, J G; Keith, D; Hill, C D; Watson, T F; Baker, W J; Hollenberg, L C L; Simmons, M Y

2018-03-07

Substitutional donor atoms in silicon are promising qubits for quantum computation with extremely long relaxation and dephasing times demonstrated. One of the critical challenges of scaling these systems is determining inter-donor distances to achieve controllable wavefunction overlap while at the same time performing high fidelity spin readout on each qubit. Here we achieve such a device by means of scanning tunnelling microscopy lithography. We measure anti-correlated spin states between two donor-based spin qubits in silicon separated by 16 ± 1 nm. By utilising an asymmetric system with two phosphorus donors at one qubit site and one on the other (2P-1P), we demonstrate that the exchange interaction can be turned on and off via electrical control of two in-plane phosphorus doped detuning gates. We determine the tunnel coupling between the 2P-1P system to be 200 MHz and provide a roadmap for the observation of two-electron coherent exchange oscillations.
Real time diffuse reflectance polarisation spectroscopy imaging to evaluate skin microcirculation

NASA Astrophysics Data System (ADS)

O'Doherty, Jim; Henricson, Joakim; Nilsson, Gert E.; Anderson, Chris; Leahy, Martin J.

2007-07-01

This article describes the theoretical development and design of a real-time microcirculation imaging system, an extension from a previously technology developed by our group. The technology utilises polarisation spectroscopy, a technique used in order to selectively gate photons returning from various compartments of human skin tissue, namely from the superficial layers of the epidermis, and the deeper backscattered light from the dermal matrix. A consumer-end digital camcorder captures colour data with three individual CCDs, and a custom designed light source consisting of a 24 LED ring light provides broadband illumination over the 400 nm - 700 nm wavelength region. Theory developed leads to an image processing algorithm, the output of which scales linearly with increasing red blood cell (RBC) concentration. Processed images are displayed online in real-time at a rate of 25 frames s -1, at a frame size of 256 x 256 pixels, and is limited only by computer RAM memory and processing speed. General demonstrations of the technique in vivo display several advantages over similar technology.
Time-gated luminescence microscopy allowing direct visual inspection of lanthanide-stained microorganisms in background-free condition.

PubMed

Jin, Dayong; Piper, James A

2011-03-15

Application of standard immuno-fluorescence microscopy techniques for detection of rare-event microorganisms in dirty samples is severely limited by autofluorescence of nontarget organisms or other debris. Time-gated detection using gateable array detectors in combination with microsecond-lifetime luminescent bioprobes (usually lanthanide-based) is highly effective in suppression of (nanosecond-lifetime) autofluorescence background; however, the complexity and cost of the instrumentation is a major barrier to application of these techniques to routine diagnostics. We report a practical, low-cost implementation of time-gated luminescence detection in a standard epifluorescence microscope which has been modified to include a high-power pulsed UV light-emitting diode (LED) illumination source and a standard fast chopper inserted in the focal plane behind a microscope eyepiece. Synchronization of the pulsed illumination/gated detection cycle is driven from the clock signal from the chopper. To achieve time-gated luminescence intensities sufficient for direct visual observation, we use high cycle rates, up to 2.5 kHz, taking advantage of the fast switching capabilities of the LED source. We have demonstrated real-time direct-visual inspection of europium-labeled Giardia lamblia cysts in dirty samples and Cryptosporidium parvum oocysts in fruit juice concentrate. The signal-to-background ratio has been enhanced by a factor of 18 in time-gated mode. The availability of low-cost, robust time-gated microscopes will aid development of long-lifetime luminescence bioprobes and accelerate their application in routine laboratory diagnostics.
Novel attributes of AlGaN/AlN/GaN/SiC HEMTs with the multiple indented channel

NASA Astrophysics Data System (ADS)

Orouji, Ali A.; Ghaffari, Majid

2015-11-01

In this paper, a high performance AlGaN/AlN/GaN/SiC High Electron Mobility Transistor (HEMT) with the multiple indented channel (MIC-HEMT) is proposed. The main focus of the proposed structure is based on reduction of the space around the gate, stop of the spread of the depletion region around the source-drain, and decrement of the thickness of the channel between the gate and drain. Therefore, the breakdown voltage increases, meanwhile the elimination of the gate depletion layer extension to source/drain decreases the gate-source and gate-drain capacitances. The optimized results reveal that the breakdown voltage and the drain saturation current increase about 178% and 46% compared with a conventional HEMT (C-HEMT), respectively. Therefore, the maximum output power density is improved by factor 4.1 in comparison with conventional one. Also, the cut-off frequency of 25.2 GHz and the maximum oscillation frequency of 92.1 GHz for the MIC-HEMT are obtained compared to 13 GHz and 43 GHz for that of the C-HEMT and the minimum figure noise decreased consequently of reducing the gate-drain and gate-source capacitances by about 42% and 40%, respectively. The proposed MIC-HEMT shows a maximum stable gain (MSG) exceeding 24.1 dB at 3.1 GHz which the greatest gain is yet reported for HEMTs, showing the potential of this device for high power RF applications.
School Reform for Positive Behaviour Support through Collaborative Learning: Utilising Lesson Study for a Learning Community

ERIC Educational Resources Information Center

Saito, Eisuke; Watanabe, Miki; Gillies, Robyn; Someya, Ikuo; Nagashima, Takashi; Sato, Masaaki; Murase, Masatsugu

2015-01-01

Recent research has emphasised educating children about positive behaviours to overcome delinquency issues, but there is little clarification of what factors lead to positive behaviours. This study analyses factors that led to children's positive behaviours at a junior high school in Japan, which experienced a dramatic turnaround after…
Families' Social Backgrounds Matter: Socio-Economic Factors, Home Learning and Young Children's Language, Literacy and Social Outcomes

ERIC Educational Resources Information Center

Hartas, Dimitra

2011-01-01

Parental support with children's learning is considered to be one pathway through which socio-economic factors influence child competencies. Utilising a national longitudinal sample from the Millennium Cohort Study, this study examined the relationship between home learning and parents' socio-economic status and their impact on young children's…
Factors That Affect South African Reading Literacy Achievement: Evidence from prePIRLS 2011

ERIC Educational Resources Information Center

van Staden, Surette; Bosker, Roel

2014-01-01

This study aims to identify factors that predict reading literacy achievement among Grade 4 learners in South Africa by utilising aspects of Carroll's model of school learning. The study draws on the preProgress in International Reading Literacy Study (prePIRLS) 2011 data, which places South African Grade 4 learners' results substantially below…
Capital, Agency, Family and the Diaspora: An Exploration of Boys' Aspirations towards Higher Education in Urban Jamaica

ERIC Educational Resources Information Center

Stockfelt, Shawanda

2015-01-01

The paper discusses factors impacting on boys' educational aspirations at two case-study schools in urban Jamaica. It focuses on boys' experience of their educational environment in relation to social, cultural and economic factors, which shapes the nature of their aspirations towards higher education. The study utilised Bourdieu's notion of…
Factors Influencing Teacher Career Satisfaction, Teacher Collaboration and Everyday Challenges: An Exploratory Factor Analysis

ERIC Educational Resources Information Center

Narayan, Nilesh Anish

2016-01-01

The main purpose of this study is to assess the construct validity of Australian eighth grade mathematics teachers' perceptions towards their career satisfaction, their teaching practice and the everyday challenges encountered in schools. The data were utilised from the Trends in International Mathematics and Science Study where a total of 802…
Extraction of mobility and Degradation coefficients in double gate junctionless transistors

NASA Astrophysics Data System (ADS)

Bhuvaneshwari, Y. V.; Kranti, Abhinav

2017-12-01

In this work, we use the modified McLarty function to understand and extract accumulation (μ acc) and bulk (μ bulk) mobility in Double Gate (DG) Junctionless (JL) MOSFETs over a wide range of doping concentration (N d) and temperature range (250 K to 520 K). The approach enables the estimation of mobility and its attenuation factors (θ 1 and θ 2) by a single method. The extracted results indicate that μ acc can reach higher values than μ bulk due to the screening effect. Results also show that θ 2 extracted in the accumulation regime of JL transistors exhibit relatively low values in comparison to inversion and accumulation mode devices. It is shown that the attenuation factor (θ 1) in JL devices designed with higher N d (≥1019 cm-3) is mainly affected by series resistance (R sd) whereas, in inversion mode (IM) and Accumulation mode (AM) devices, θ 1 factor is governed by both the intrinsic mobility reduction factor (θ 10) and R sd. Additionally, the impact of variation in oxide thickness (T ox), gate length (L g), N d and temperature on θ 1 and θ 2 has been investigated for JL transistor. The weak dependence of μ bulk and μ acc on temperature shows the prevalence of coulomb scattering over phonon scattering for heavily doped JL transistors. The work provides insights into different modes of operation, extraction of mobility and attenuation factors which will be useful for the development of compact models for JL transistors.
Substance use and self-harm: a cross-sectional study of the prevalence, correlates and patterns of medical service utilisation among patients admitted to a South African hospital.

PubMed

Breet, Elsie; Bantjes, Jason; Lewis, Ian

2018-03-06

Substance use is a potentially modifiable risk factor for suicidal behaviour. Little is known about the epidemiology of substance use among self-harm patients in South Africa. This study set out to collect epidemiological data about the prevalence, correlates, and patterns of medical service utilisation among self-harm patients who used substances at the time of self-injury. Data from 238 consecutive self-harm patients treated at an urban hospital in South Africa were analysed using bivariate and multivariate statistics. Approximately 20% of patients reported substance use at the time of self-harm. When compared to other self-harm patients, higher rates of patients who had used substances: had depressed levels of consciousness on admission; utilised more medical resources and required longer hospital admissions; cited relationship difficulties and financial concerns as reasons for their self-harm; reported a previous episode of self-harm; and intended to die as a result of their injuries. Although the observed differences were not statistically significant (p > 0.05), the proportional differences were congruent with international literature. Acute use of substances among self-harm patients warrants more focused research and clinical attention particularly in the context of reducing utilisation of scarce medical resources.
Open-Gated pH Sensor Fabricated on an Undoped-AlGaN/GaN HEMT Structure

PubMed Central

Abidin, Mastura Shafinaz Zainal; Hashim, Abdul Manaf; Sharifabad, Maneea Eizadi; Rahman, Shaharin Fadzli Abd; Sadoh, Taizoh

2011-01-01

The sensing responses in aqueous solution of an open-gated pH sensor fabricated on an AlGaN/GaN high-electron-mobility-transistor (HEMT) structure are investigated. Under air-exposed ambient conditions, the open-gated undoped AlGaN/GaN HEMT only shows the presence of a linear current region. This seems to show that very low Fermi level pinning by surface states exists in the undoped AlGaN/GaN sample. In aqueous solution, typical current-voltage (I-V) characteristics with reasonably good gate controllability are observed, showing that the potential of the AlGaN surface at the open-gated area is effectively controlled via aqueous solution by the Ag/AgCl gate electrode. The open-gated undoped AlGaN/GaN HEMT structure is capable of distinguishing pH level in aqueous electrolytes and exhibits linear sensitivity, where high sensitivity of 1.9 mA/pH or 3.88 mA/mm/pH at drain-source voltage, VDS = 5 V is obtained. Due to the large leakage current where it increases with the negative gate voltage, Nernstian like sensitivity cannot be determined as commonly reported in the literature. This large leakage current may be caused by the technical factors rather than any characteristics of the devices. Surprisingly, although there are some imperfections in the device preparation and measurement, the fabricated devices work very well in distinguishing the pH levels. Suppression of current leakage by improving the device preparation is likely needed to improve the device performance. The fabricated device is expected to be suitable for pH sensing applications. PMID:22163786
Patients’ subjective concepts about primary healthcare utilisation: the study protocol of a qualitative comparative study between Norway and Germany

PubMed Central

Herrmann, Wolfram J; Haarmann, Alexander; Flick, Uwe; Bærheim, Anders; Lichte, Thomas; Herrmann, Markus

2013-01-01

Background In Germany, utilisation of ambulatory healthcare services is high compared with other countries: While a study based on the process data of German statutory health insurances showed an average of 17.1 physician-patient-contacts per year, the comparable figure for Norway is about five. The usual models of healthcare utilisation, such as Rosenstock's Health Belief Model and Andersen's Behavioural Model, cannot explain these differences adequately. Organisational factors of the healthcare system, such as gatekeeping, do not explain the magnitude of the differences. Our hypothesis is that patients’ subjective concepts about primary healthcare utilisation play a major role in explaining different healthcare utilisation behaviour in different countries. Hence, the aim of this study is to explore these subjective concepts comparatively, between Germany and Norway. Methods/design With that aim in mind, we chose a comparative qualitative study design. In Norway and Germany, we are going to interview 20 patients each with qualitative episodic interviews. In addition, we are going to conduct participant observation in four German and four Norwegian primary care practices. The data will be analysed by thematic coding. Using selected categories, we are going to conduct comparative case and group analyses. Ethics and dissemination The study adheres to the Declaration of Helsinki. All interviewees will sign informed consent forms and all patients will be observed during consultation. Strict rules for data security will apply. Developed theory and policy implications are going to be disseminated by a workshop, presentations for experts and laypersons and publications. PMID:23794555
Dissecting the involvement of LC3B and GATE-16 in p62 recruitment into autophagosomes.

PubMed

Shvets, Elena; Abada, Adi; Weidberg, Hilla; Elazar, Zvulun

2011-07-01

Autophagy is a major intracellular trafficking pathway that delivers proteins and organelles from the cytoplasm into lysosomes for consequential degradation and recycling. Mammalian Atg8s are key autophagic factors that undergo a unique ubiquitin-like conjugation to the lipid phase of the autophagosomal membrane. In addition to their activity in autophagosome formation, several Atg8s directly bind p62/SQSTM1. Here we show that LC3 and GATE-16 differ in their mode of p62 binding. While the soluble form of both LC3 and GATE-16 bind p62, only the lipidated form of LC3 is directly involved in p62 recruitment into autophagosomes. Moreover, by utilizing chimeras of LC3 and GATE-16 where their N-terminus was swapped, we determined the regions responsible for this differential binding. Accordingly, we found that the chimera of GATE-16 containing the LC3 N-terminal region acts similarly to wild-type LC3 in recruiting p62 into autophagosomes. We therefore propose that LC3 is responsible for the final stages of p62 incorporation into autophagosomes, a process selectively mediated by its N-terminus.
Cervical cancer awareness and risk factors among female university students.

PubMed

Buga, G A

1998-07-01

Population cervical screening programmes are necessary for meaningfully reducing cervical cancer morbidity and mortality. Because of the high incidence of cervical cancer in South Africa, the need for a national screening programme has become evident. The success of such a programme will depend on, among others, the level of cervical cancer awareness among the target population, and their willingness to utilise cytological services and to comply with treatment and follow up protocols. We conducted a survey among female university students, as an elite group of women, to determine their level of cervical cancer awareness and the prevalence of the major risk factors for cervical cancer among them, their rate of utilisation of existing Pap smear services, and their attitudes to Pap smears in general. The majority of respondents were young, single (93.0%) and sexually active (86.9%,) having initiated sexual activity at a mean age of 17.27 +/- 2.18 years. There was a high prevalence of the major risk factors for cervical cancer among the respondents, and these included initiation of coitus before 18 years (53.3%), multiple sexual partners (73.6%), male partner with other partners (37.7%), and previous history of sexually transmitted diseases (42.2%) and vulval warts (4.7%). Their overall knowledge of cervical cancer was poor, although the majority of respondents were able to identify the major risk factors from a given list. This level of awareness of cervical cancer risk factors, however, did not translate into appreciation of personal risk of cervical cancer, safer sex practices or utilisation of Pap smear services. In conclusion, this elite group of women is at a high risk of cervical cancer and would benefit from cervical screening programmes. This would have to be coupled with measures to increase the level of awareness and knowledge of cervical cancer and its prevention.
Preliminary analysis for integration of spot-scanning proton beam therapy and real-time imaging and gating.

PubMed

Shimizu, S; Matsuura, T; Umezawa, M; Hiramoto, K; Miyamoto, N; Umegaki, K; Shirato, H

2014-07-01

Spot-scanning proton beam therapy (PBT) can create good dose distribution for static targets. However, there exists larger uncertainty for tumors that move due to respiration, bowel gas or other internal circumstances within the patients. We have developed a real-time tumor-tracking radiation therapy (RTRT) system that uses an X-ray linear accelerator gated to the motion of internal fiducial markers introduced in the late 1990s. Relying on more than 10 years of clinical experience and big log data, we established a real-time image gated proton beam therapy system dedicated to spot scanning. Using log data and clinical outcomes derived from the clinical usage of the RTRT system since 1999, we have established a library to be used for in-house simulation for tumor targeting and evaluation. Factors considered to be the dominant causes of the interplay effects related to the spot scanning dedicated proton therapy system are listed and discussed. Total facility design, synchrotron operation cycle, and gating windows were listed as the important factors causing the interplay effects contributing to the irradiation time and motion-induced dose error. Fiducial markers that we have developed and used for the RTRT in X-ray therapy were suggested to have the capacity to improve dose distribution. Accumulated internal motion data in the RTRT system enable us to improve the operation and function of a Spot-scanning proton beam therapy (SSPT) system. A real-time-image gated SSPT system can increase accuracy for treating moving tumors. The system will start clinical service in early 2014. Copyright © 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.
Genomic Mining of Prokaryotic Repressors for Orthogonal Logic Gates

PubMed Central

Stanton, Brynne C.; Nielsen, Alec A.K.; Tamsir, Alvin; Clancy, Kevin; Peterson, Todd; Voigt, Christopher A.

2014-01-01

Genetic circuits perform computational operations based on interactions between freely diffusing molecules within a cell. When transcription factors are combined to build a circuit, unintended interactions can disrupt its function. Here, we apply “part mining” to build a library of 73 TetR-family repressors gleaned from prokaryotic genomes. The operators of a subset were determined using an in vitro method and this information was used to build synthetic promoters. The promoters and repressors were screened for cross-reactions. Of these, 16 were identified that both strongly repress their cognate promoter (5- to 207-fold) and do not interact with other promoters. Each repressor:promoter pair was converted to a NOT gate and characterized. Used as a set of 16 NOR gates, there are >1054 circuits that could be built by changing the pattern of input and output promoters. This represents a large set of compatible gates that can be used to construct user-defined circuits. PMID:24316737
Improved Range Estimation Model for Three-Dimensional (3D) Range Gated Reconstruction

PubMed Central

Chua, Sing Yee; Guo, Ningqun; Tan, Ching Seong; Wang, Xin

2017-01-01

Accuracy is an important measure of system performance and remains a challenge in 3D range gated reconstruction despite the advancement in laser and sensor technology. The weighted average model that is commonly used for range estimation is heavily influenced by the intensity variation due to various factors. Accuracy improvement in term of range estimation is therefore important to fully optimise the system performance. In this paper, a 3D range gated reconstruction model is derived based on the operating principles of range gated imaging and time slicing reconstruction, fundamental of radiant energy, Laser Detection And Ranging (LADAR), and Bidirectional Reflection Distribution Function (BRDF). Accordingly, a new range estimation model is proposed to alleviate the effects induced by distance, target reflection, and range distortion. From the experimental results, the proposed model outperforms the conventional weighted average model to improve the range estimation for better 3D reconstruction. The outcome demonstrated is of interest to various laser ranging applications and can be a reference for future works. PMID:28872589
[Dialin: infection surveillance network for haemodialysis patients. First results].

PubMed

Ayzac, Louis; Béruard, Michel; Girard, Raphaële; Hannoun, Jacques; Kuentz, François; Marc, Jean-Michel; Moreau-Gaudry, Xavier; Roche, Catherine; Tressières, Benoît; Uzan, Marc

2009-02-01

To show results of the first year of an infection surveillance network for haemodialysis patients (Dialin). In order to improve the security and quality of care, six haemodialysis centers have organized an infection watching network. The purpose of the network is to compare of the watching results between centers. This comparison includes vascular access infection (VAI), bacteraemia and C viral hepatitis. The heterogeneous pattern has been also taken into account. SURVEY TYPE: Multicenter prospective permanent survey. Six hundred and sixty-four haemodialyzed chronic patients, followed during one year (2005), in six voluntary haemodialysis centers. This survey has based on 71,688 treatment sessions corresponding to 6257.5 months of haemodialysis (HM). As with the heterogeneity among centers, the acquired infection standardized ratios (observed/expected) (AISR) and 95% confidence interval are computed with Cox model which includes confounding factors found in literature or in the preliminary stage of the survey. VAI crude rate was 0.47 per 100HM, 0.10 per 1000 native fistulae utilisation days, 0.45 per 1000 days of prosthetic graft utilisation and 0.44 per 1000 days of catheter utilisation. Bacteraemia crude incidence rate was 0.69 per 100HM, 0.02 per 1000 days of native fistulae utilisation, 0.00 per 1000 days of prosthetic graft utilisation and 0.39 per 1000 days of catheter utilisation. No new case of C viral hepatitis was found. Prevalence rate at the beginning of the survey was 5.3% (35 over 664). Two centers had a significantly high AISR for VAI and two centers had a significantly low AISR for VAI. One center had a significantly high AISR for bacteraemia and one center had a significantly low AISR for bacteraemia. The first year of Dialin running demonstrates the importance of standardised surveillance method in VAI and bacteraemia surveillance but not for viral hepatitis.
[Frequency of use of school cafeterias in middle and high schools in 3 French districts].

PubMed

Michaud, C; Feur, E; Gerbouin-Rérolle, P; Leynaud-Rouaud, C; Chateil, S; Gourdon, M

2000-09-01

Reports from the French Ministry of Education warn of a decrease in the use of school food services, especially in sensitive urban areas. They also suggest that this decline has led to cases of malnutrition. This article describes the characteristics of the current supply of school meals and measures the evolution of demand observed between 1992 and 1996 in relation to the economic situation of students' families. The study was carried out in 3 departments in France: Doubs, Herault, and Val de Marne. The administrators of all public and private middle and high schools in the 3 departments received a questionnaire asking them to describe the services offered in their cafeterias and to provide the corresponding statistical and accounting data. External food services near the schools were also taken into account. Seventy-nine percent of schools responded to the survey. Concerning the services offered, 91% of schools have their own cafeterias, of which 81% are managed by the schools. Concerning the evolution of utilisation, a significant decrease in the number of meals served in seen in middle schools. On the other hand, high schools have observed stable utilisation. The positive changes in utilisation are linked, in middle schools, to characteristics of the schools' internal food services (self-service, choice of main courses, modulation of seats). In high schools, positive changes in the utilisation of school services are linked to the lack of external food services near the schools. As middle schools and high schools control the logistics and management of food services offered to students, they are potentially in a position to influence a policy on this issue. The evolution in utilisation is very different among departments and between middle and high schools. While economic precariousness has a negative structural effect on utilisation, it doesn't seem to be a major factor in the evolution of the decrease observed over the past few years.

Open Online System Adoption in K-12 as a Democratising Factor

ERIC Educational Resources Information Center

Kimmons, Royce

2015-01-01

This study seeks to understand how district size and wealth factors influence the adoption of open-source online systems in primary and secondary (K-12) education. Most schools now utilise online systems (e.g. CMS, LMS, SIS) for a number of purposes, and it is anticipated that no-cost and open-source systems could be of great value for…
A Theory of Planned Behaviour-Based Analysis of TIMSS 2011 to Determine Factors Influencing Inquiry Teaching Practices in High-Performing Countries

ERIC Educational Resources Information Center

Pongsophon, Pongprapan; Herman, Benjamin C.

2017-01-01

Given the abundance of literature describing the strong relationship between inquiry-based teaching and student achievement, more should be known about the factors impacting science teachers' classroom inquiry implementation. This study utilises the theory of planned behaviour to propose and validate a causal model of inquiry-based teaching…
Colorectal cancer screening behaviour and associated factors among Chinese aged 50 and above in Hong Kong - a population-based survey.

PubMed

So, W K W; Choi, K C; Chan, D N S; Shiu, A T Y; Ho, S S M; Chan, H Y L; Lam, W W T; Cheng, K K F; Goggins, W; Chan, C W H

2012-09-01

This study reports the uptake rate of colorectal cancer screening among Chinese people aged 50 or above and the identified factors associated with the likelihood of undergoing such screening. A cross-sectional population-based telephone survey was conducted in Hong Kong during the period 2 to 28 May 2007. The survey covered demographics, perceived health status and susceptibility to cancer, utilisation of complementary medicine, family history of cancer and cancer screening behaviour. The survey was completed by 2004 Hong Kong Chinese residents aged 50 or older (response rate = 66.6%). The uptake rate of a fecal occult blood test and a colonoscopy was 12% and 19% respectively. Factors associated with colorectal cancer screening behaviour included: male participants, ex-smokers, with cancer or other serious disease, a family history of cancer, perceived health status fair or poor, regular visits to a doctor to look after health, and utilisation of complementary medicine. The uptake rate of this study population was low though an increasing trend did appear. Heath education and promotion programmes may focus on these identified factors to facilitate colorectal cancer screening in a Chinese population. Copyright © 2011 Elsevier Ltd. All rights reserved.
Independent gate control of injected and detected spin currents in CVD graphene nonlocal spin valves

NASA Astrophysics Data System (ADS)

Anugrah, Yoska; Hu, Jiaxi; Stecklein, Gordon; Crowell, Paul A.; Koester, Steven J.

2018-01-01

Graphene is an ideal material for spintronic devices due to its low spin-orbit coupling and high mobility. One of the most important potential applications of graphene spintronics is for use in neuromorphic computing systems, where the tunable spin resistance of graphene can be used to apply analog weighting factors. A key capability needed to achieve spin-based neuromorphic computing systems is to achieve distinct regions of control, where injected and detected spin currents can be tuned independently. Here, we demonstrate the ability to achieve such independent control using a graphene spin valve geometry where the injector and detector regions are modulated by two separate bottom gate electrodes. The spin transport parameters and their dependence on each gate voltage are extracted from Hanle precession measurements. From this analysis, local spin transport parameters and their dependence on the local gate voltage are found, which provide a basis for a spatially-resolved spin resistance network that simulates the device. The data and model are used to calculate the spin currents flowing into, through, and out of the graphene channel. We show that the spin current flowing through the graphene channel can be modulated by 30% using one gate and that the spin current absorbed by the detector can be modulated by 50% using the other gate. This result demonstrates that spin currents can be controlled by locally tuning the spin resistance of graphene. The integration of chemical vapor deposition (CVD) grown graphene with local gates allows for the implementation of large-scale integrated spin-based circuits.
Recent advance in high manufacturing readiness level and high temperature CMOS mixed-signal integrated circuits on silicon carbide

NASA Astrophysics Data System (ADS)

Weng, M. H.; Clark, D. T.; Wright, S. N.; Gordon, D. L.; Duncan, M. A.; Kirkham, S. J.; Idris, M. I.; Chan, H. K.; Young, R. A. R.; Ramsay, E. P.; Wright, N. G.; Horsfall, A. B.

2017-05-01

A high manufacturing readiness level silicon carbide (SiC) CMOS technology is presented. The unique process flow enables the monolithic integration of pMOS and nMOS transistors with passive circuit elements capable of operation at temperatures of 300 °C and beyond. Critical to this functionality is the behaviour of the gate dielectric and data for high temperature capacitance-voltage measurements are reported for SiO2/4H-SiC (n and p type) MOS structures. In addition, a summary of the long term reliability for a range of structures including contact chains to both n-type and p-type SiC, as well as simple logic circuits is presented, showing function after 2000 h at 300 °C. Circuit data is also presented for the performance of digital logic devices, a 4 to 1 analogue multiplexer and a configurable timer operating over a wide temperature range. A high temperature micro-oven system has been utilised to enable the high temperature testing and stressing of units assembled in ceramic dual in line packages, including a high temperature small form-factor SiC based bridge leg power module prototype, operated for over 1000 h at 300 °C. The data presented show that SiC CMOS is a key enabling technology in high temperature integrated circuit design. In particular it provides the ability to realise sensor interface circuits capable of operating above 300 °C, accommodate shifts in key parameters enabling deployment in applications including automotive, aerospace and deep well drilling.
A step by step selection method for the location and the size of a waste-to-energy facility targeting the maximum output energy and minimization of gate fee.

PubMed

Kyriakis, Efstathios; Psomopoulos, Constantinos; Kokkotis, Panagiotis; Bourtsalas, Athanasios; Themelis, Nikolaos

2017-06-23

This study attempts the development of an algorithm in order to present a step by step selection method for the location and the size of a waste-to-energy facility targeting the maximum output energy, also considering the basic obstacle which is in many cases, the gate fee. Various parameters identified and evaluated in order to formulate the proposed decision making method in the form of an algorithm. The principle simulation input is the amount of municipal solid wastes (MSW) available for incineration and along with its net calorific value are the most important factors for the feasibility of the plant. Moreover, the research is focused both on the parameters that could increase the energy production and those that affect the R1 energy efficiency factor. Estimation of the final gate fee is achieved through the economic analysis of the entire project by investigating both expenses and revenues which are expected according to the selected site and outputs of the facility. In this point, a number of commonly revenue methods were included in the algorithm. The developed algorithm has been validated using three case studies in Greece-Athens, Thessaloniki, and Central Greece, where the cities of Larisa and Volos have been selected for the application of the proposed decision making tool. These case studies were selected based on a previous publication made by two of the authors, in which these areas where examined. Results reveal that the development of a «solid» methodological approach in selecting the site and the size of waste-to-energy (WtE) facility can be feasible. However, the maximization of the energy efficiency factor R1 requires high utilization factors while the minimization of the final gate fee requires high R1 and high metals recovery from the bottom ash as well as economic exploitation of recovered raw materials if any.
Iron deficiency anaemia in chronic kidney disease.

PubMed

Wittwer, Iain

2013-09-01

Iron Deficiency Anaemia (IDA) has been shown to be the most common cause of anaemia worldwide. It is accepted that people with chronic kidney disease (CKD) develop anaemia as their kidney function declines. To better understand IDA in CKD, it is necessary to appreciate the normal iron metabolism and utilisation of iron and how these processes can be disordered in patients with CKD. The problems related to infection / inflammation and oxidative stress are examined. Whilst National and international guidelines recommend specific tests for IDA, these and alternative tests are reviewed. Whilst iron supplementation is necessary for CKD patients with IDA, iron metabolism and utilisation can be affected by factors such as infection or inflammation. Iron is essential element for all life, it can be toxic to cells through the process of oxidative stress. The recommended tests for IDA may be affected by factors such as infection and inflammation. Alternative tests are available, which may be a more accurate indicator of IDA as they are not affected by external factors. © 2013 European Dialysis and Transplant Nurses Association/European Renal Care Association.
Antenatal Care Utilisation and Content between Low-Risk and High-Risk Pregnant Women

PubMed Central

Yeoh, Ping Ling; Hornetz, Klaus; Dahlui, Maznah

2016-01-01

Background The purpose of antenatal care is to monitor and improve the wellbeing of the mother and foetus. The World Health Organization recommends risk-oriented strategy that includes: (i) routine care to all women, (ii) additional care for women with moderately severe diseases and complications, (iii) specialised obstetrical and neonatal care for women with severe diseases and complications. Antenatal care is concerned with adequate care in order to be effective. Measurement for adequacy of antenatal care often applies indexes that assess initiation of care and number of visits. In addition, adequacy of care content should also be assessed. Results of studies in developed settings demonstrate that women without risk factors use antenatal services more frequently than recommended. Such over-utilisation is problematic for low-resourced settings. Moreover, studies show that a substantial proportion of high-risk women had utilisation or content of care below the recommended standard. Yet studies in developing countries have seldom included a comparison between low-risk and high-risk women. The purpose of the study was therefore to assess adequacy of care and pregnancy outcomes for the different risk groups. Methods A retrospective study using a multistage sampling technique, at public-funded primary health care clinics was conducted. Antenatal utilisation level was assessed using a modified Adequacy of Prenatal Care Utilisation index that measures the timing for initiation of care and observed-to-expected visits ratio. Adequacy of antenatal care content assessed compliance to routine care based on the local guidelines. Results Intensive or “adequate-plus” antenatal care utilisation as defined by the modified index was noted in over half of the low-risk women. On the other hand, there were 26% of the high-risk women without the expected intensive utilisation. Primary- or non-educated high-risk women were less likely to have a higher antenatal care utilisation level compared with tertiary educated ones (OR = 0.20, P = 0.003). Half of all women had <80% of the recommended antenatal care content. A higher proportion of high-risk than low-risk women scored <80% of the routine care content (p<0.015). The majority of the additional laboratory tests were performed on high-risk women. Provision of antenatal education showed comparatively poor compliance to guidelines, more than half of the antenatal advice topics assessed were rarely provided to the women. High-risk women were associated with a higher prevalence of adverse pregnancy outcome. Conclusions Disproportionate utilisation of antenatal care according to risk level of pregnancy indicates the need for better scheduling of care. The risk-oriented approach often results in a tendency to focus on the risk conditions of the women. Training interventions are recommended to improve communication and to help healthcare professionals understand the priorities of the women. Further studies are required to assess the reason for disproportionate utilisation of antenatal care according to risk level and how delivery of antenatal advice can be improved, reviewing both user and provider perspectives. PMID:27010482
Transduction of Voltage and Ca2+ Signals by Slo1 BK Channels

PubMed Central

Hoshi, T.; Pantazis, A.; Olcese, R.

2013-01-01

Large-conductance Ca2+- and voltage-gated K+ channels are activated by an increase in intracellular Ca2+ concentration and/or depolarization. The channel activation mechanism is well described by an allosteric model encompassing the gate, voltage sensors, and Ca2+ sensors, and the model is an excellent framework to understand the influences of auxiliary β and γ subunits and regulatory factors such as Mg2+. Recent advances permit elucidation of structural correlates of the biophysical mechanism. PMID:23636263
Positron annihilation at the Si/SiO2 interface

NASA Astrophysics Data System (ADS)

Leung, T. C.; Weinberg, Z. A.; Asoka-Kumar, P.; Nielsen, B.; Rubloff, G. W.; Lynn, K. G.

1992-01-01

Variable-energy positron annihilation depth-profiling has been applied to the study of the Si/SiO2 interface in Al-gate metal-oxide-semiconductor (MOS) structures. For both n- and p-type silicon under conditions of negative gate bias, the positron annihilation S-factor characteristic of the interface (Sint) is substantially modified. Temperature and annealing behavior, combined with known MOS physics, suggest strongly that Sint depends directly on holes at interface states or traps at the Si/SiO2 interface.
Living with a partner and health care use – results from the MONICA survey Augsburg in Southern Germany

PubMed Central

Huber, Carola A.; Baumeister, Sebastian E.; Ladwig, Karl-Heinz; Mielck, Andreas

2007-01-01

Objective: Several studies have shown that social relationships are associated with health care use. This study aims to test if and to which extent a proximal element of social relationships, particularly living together with a partner, influences the health care utilisation in the same way as a distal element such as group membership. Methods: On the basis of a representative random sample of a southern German population (4856 participants), the associations were assessed between the following groups of variables: number of consultations with the general practitioner or internists, type of social relationships (living with a partner, friends, relatives, group memberships), need (evaluated and perceived health status), socio-demographic variables. Results: All analyses showed associations between living with a partner and health care utilisation. Individuals living with a partner had lower levels of utilisation than individuals not living with a partner (mean: 4.3 vs. 5.2). These associations persisted after controlling for socio-demographic and need variables. For the other indicators of social relationships, though, there were no significant associations with outpatient visits. Conclusions: Distinguishing between different types of social relationships is important for disentangling the overall effects of social relationships on health care utilisation. Also, the empirical findings confirm that health care research should not be restricted to medical variables, but should also include psycho-social factors. PMID:19742289
Drivers and risk factors for circulating African swine fever virus in Uganda, 2012-2013.

PubMed

Kabuuka, T; Kasaija, P D; Mulindwa, H; Shittu, A; Bastos, A D S; Fasina, F O

2014-10-01

We explored observed risk factors and drivers of infection possibly associated with African swine fever (ASF) epidemiology in Uganda. Representative sub-populations of pig farms and statistics were used in a case-control model. Indiscriminate disposal of pig viscera and waste materials after slaughter, including on open refuse dumps, farm-gate buyers collecting pigs and pig products from within a farm, and retention of survivor pigs were plausible risk factors. Wire mesh-protected windows in pig houses were found to be protective against ASF infection. Sighting engorged ticks on pigs, the presence of a lock for each pig pen and/or a gate at the farm entrance were significantly associated with infection/non-infection; possible explanations were offered. Strict adherence to planned within-farm and community-based biosecurity, and avoidance of identified risk factors is recommended to reduce infection. Training for small-scale and emerging farmers should involve multidimensional and multidisciplinary approaches to reduce human-related risky behaviours driving infection. Copyright © 2014. Published by Elsevier Ltd.
(Reinforcing) Factors Influencing a Physical Education Teacher's Use of the Direct Instruction Model Teaching Games

ERIC Educational Resources Information Center

Jayantilal, Kumar; O'Leary, Nick

2017-01-01

The purpose of this study was to explore how a physical education (PE) teacher employed the direct instruction model (DIM) teaching games in a United Kingdom secondary school. The research sought to identify how the teacher utilised the DIM and those factors that influenced his use of the model. Occupational socialization was used to identify the…
Centrally Determined Standardization of Flow Cytometry Methods Reduces Interlaboratory Variation in a Prospective Multicenter Study.

PubMed

Westera, Liset; van Viegen, Tanja; Jeyarajah, Jenny; Azad, Azar; Bilsborough, Janine; van den Brink, Gijs R; Cremer, Jonathan; Danese, Silvio; D'Haens, Geert; Eckmann, Lars; Faubion, William; Filice, Melissa; Korf, Hannelie; McGovern, Dermot; Panes, Julian; Salas, Azucena; Sandborn, William J; Silverberg, Mark S; Smith, Michelle I; Vermeire, Severine; Vetrano, Stefania; Shackelton, Lisa M; Stitt, Larry; Jairath, Vipul; Levesque, Barrett G; Spencer, David M; Feagan, Brian G; Vande Casteele, Niels

2017-11-02

Flow cytometry (FC) aids in characterization of cellular and molecular factors involved in pathologic immune responses. Although FC has potential to facilitate early drug development in inflammatory bowel disease, interlaboratory variability limits its use in multicenter trials. Standardization of methods may address this limitation. We compared variability in FC-aided quantitation of T-cell responses across international laboratories using three analytical strategies. Peripheral blood mononuclear cells (PBMCs) were isolated from three healthy donors, stimulated with phorbol 12-myristate 13-acetate and ionomycin at a central laboratory, fixed, frozen, and shipped to seven international laboratories. Permeabilization and staining was performed in triplicate at each laboratory using a common protocol and centrally provided reagents. Gating was performed using local gating with a local strategy (LGLS), local gating with a central strategy (LGCS), and central gating (CG). Median cell percentages were calculated across triplicates and donors, and reported for each condition and strategy. The coefficient of variation (CV) was calculated across laboratories. Between-strategy comparisons were made using a two-way analysis of variance adjusting for donor. Mean interlaboratory CV ranged from 1.8 to 102.1% depending on cell population and gating strategy (LGLS, 4.4-102.1%; LGCS, 10.9-65.6%; CG, 1.8-20.9%). Mean interlaboratory CV differed significantly across strategies and was consistently lower with CG. Central gating was the only strategy with mean CVs consistently lower than 25%, which is a proposed standard for pharmacodynamic and exploratory biomarker assays.
Superconducting quantum circuits at the surface code threshold for fault tolerance.

PubMed

Barends, R; Kelly, J; Megrant, A; Veitia, A; Sank, D; Jeffrey, E; White, T C; Mutus, J; Fowler, A G; Campbell, B; Chen, Y; Chen, Z; Chiaro, B; Dunsworth, A; Neill, C; O'Malley, P; Roushan, P; Vainsencher, A; Wenner, J; Korotkov, A N; Cleland, A N; Martinis, John M

2014-04-24

A quantum computer can solve hard problems, such as prime factoring, database searching and quantum simulation, at the cost of needing to protect fragile quantum states from error. Quantum error correction provides this protection by distributing a logical state among many physical quantum bits (qubits) by means of quantum entanglement. Superconductivity is a useful phenomenon in this regard, because it allows the construction of large quantum circuits and is compatible with microfabrication. For superconducting qubits, the surface code approach to quantum computing is a natural choice for error correction, because it uses only nearest-neighbour coupling and rapidly cycled entangling gates. The gate fidelity requirements are modest: the per-step fidelity threshold is only about 99 per cent. Here we demonstrate a universal set of logic gates in a superconducting multi-qubit processor, achieving an average single-qubit gate fidelity of 99.92 per cent and a two-qubit gate fidelity of up to 99.4 per cent. This places Josephson quantum computing at the fault-tolerance threshold for surface code error correction. Our quantum processor is a first step towards the surface code, using five qubits arranged in a linear array with nearest-neighbour coupling. As a further demonstration, we construct a five-qubit Greenberger-Horne-Zeilinger state using the complete circuit and full set of gates. The results demonstrate that Josephson quantum computing is a high-fidelity technology, with a clear path to scaling up to large-scale, fault-tolerant quantum circuits.
Tumor control probability reduction in gated radiotherapy of non-small cell lung cancers: a feasibility study.

PubMed

Siochi, R Alfredo; Kim, Yusung; Bhatia, Sudershan

2014-10-16

We studied the feasibility of evaluating tumor control probability (TCP) reductions for tumor motion beyond planned gated radiotherapy margins. Tumor motion was determined from cone-beam CT projections acquired for patient setup, intrafraction respiratory traces, and 4D CTs for five non-small cell lung cancer (NSCLC) patients treated with gated radiotherapy. Tumors were subdivided into 1 mm sections whose positions and doses were determined for each beam-on time point. (The dose calculation model was verified with motion phantom measurements.) The calculated dose distributions were used to generate the treatment TCPs for each patient. The plan TCPs were calculated from the treatment planning dose distributions. The treatment TCPs were compared to the plan TCPs for various models and parameters. Calculated doses matched phantom measurements within 0.3% for up to 3 cm of motion. TCP reductions for excess motion greater than 5mm ranged from 1.7% to 11.9%, depending on model parameters, and were as high as 48.6% for model parameters that simulated an individual patient. Repeating the worst case motion for all fractions increased TCP reductions by a factor of 2 to 3, while hypofractionation decreased these reductions by as much as a factor of 3. Treatment motion exceeding gating margins by more than 5 mm can lead to considerable TCP reductions. Appropriate margins for excess motion are recommended, unless applying daily tumor motion verification and adjusting thegating window.
Effects of written action plan adherence on COPD exacerbation recovery.

PubMed

Bischoff, Erik W M A; Hamd, Dina H; Sedeno, Maria; Benedetti, Andrea; Schermer, Tjard R J; Bernard, Sarah; Maltais, François; Bourbeau, Jean

2011-01-01

The effects of written action plans on recovery from exacerbations of chronic obstructive pulmonary disease (COPD) have not been well studied. The aims of this study were to assess the effects of adherence to a written action plan on exacerbation recovery time and unscheduled healthcare utilisation and to explore factors associated with action plan adherence. This was a 1-year prospective cohort study embedded in a randomised controlled trial. Exacerbation data were recorded for 252 patients with COPD who received a written action plan for prompt treatment of exacerbations with the instructions to initiate standing prescriptions for both antibiotics and prednisone within 3 days of exacerbation onset. Following the instructions was defined as adherence to the action plan. From the 288 exacerbations reported by 143 patients, start dates of antibiotics or prednisone were provided in 217 exacerbations reported by 119 patients (53.8% male, mean age 65.4 years, post-bronchodilator forced expiratory volume in 1 s (FEV(1)) 43.9% predicted). In 40.1% of exacerbations, patients adhered to their written action plan. Adherence reduced exacerbation recovery time with statistical (p=0.0001) and clinical (-5.8 days) significance, but did not affect unscheduled healthcare utilisation (OR 0.94, 95% CI 0.49 to 1.83). Factors associated with an increased likelihood of adherence were influenza vaccination, cardiac comorbidity, younger age and lower FEV(1) as percentage predicted. This study shows that adherence to a written action plan is associated with a reduction in exacerbation recovery time by prompt treatment. Knowing the factors that are associated with proper and prompt utilisation of an action plan permits healthcare professionals to better focus their self-management support on appropriate patients.
Current transport mechanisms in mercury cadmium telluride diode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gopal, Vishnu, E-mail: vishnu-46@yahoo.com, E-mail: wdhu@mail.sitp.ac.cn; Li, Qing; He, Jiale

This paper reports the results of modelling of the current-voltage characteristics (I-V) of a planar mid-wave Mercury Cadmium Telluride photodiode in a gate controlled diode experiment. It is reported that the diode exhibits nearly ideal I-V characteristics under the optimum surface potential leading to the minimal surface leakage current. Deviations from the optimum surface potential lead to non ideal I–V characteristics, indicating a strong relationship between the ideality factor of the diode with its surface leakage current. Diode's I–V characteristics have been modelled over a range of gate voltages from −9 V to −2 V. This range of gate voltages includes accumulation,more » flat band, and depletion and inversion conditions below the gate structure of the diode. It is shown that the I–V characteristics of the diode can be very well described by (i) thermal diffusion current, (ii) ohmic shunt current, (iii) photo-current due to background illumination, and (iv) excess current that grows by the process of avalanche multiplication in the gate voltage range from −3 V to −5 V that corresponds to the optimum surface potential. Outside the optimum gate voltage range, the origin of the excess current of the diode is associated with its high surface leakage currents. It is reported that the ohmic shunt current model applies to small surface leakage currents. The higher surface leakage currents exhibit a nonlinear shunt behaviour. It is also shown that the observed zero-bias dynamic resistance of the diode over the entire gate voltage range is the sum of ohmic shunt resistance and estimated zero-bias dynamic resistance of the diode from its thermal saturation current.« less
Gated IR imaging with 128 × 128 HgCdTe electron avalanche photodiode FPA

NASA Astrophysics Data System (ADS)

Beck, Jeff; Woodall, Milton; Scritchfield, Richard; Ohlson, Martha; Wood, Lewis; Mitra, Pradip; Robinson, Jim

2007-04-01

The next generation of IR sensor systems will include active imaging capabilities. One example of such a system is a gated-active/passive system. The gated-active/passive system promises long-range target detection and identification. A detector that is capable of both active and passive modes of operation opens up the possibility of a self-aligned system that uses a single focal plane. The detector would need to be sensitive in the 3-5 μm band for passive mode operation. In the active mode, the detector would need to be sensitive in eye-safe range, e.g. 1.55 μm, and have internal gain to achieve the required system sensitivity. The MWIR HgCdTe electron injection avalanche photodiode (e-APD) not only provides state-of-the-art 3-5 μm spectral sensitivity, but also high avalanche photodiode gain without minimal excess noise. Gains of greater than 1000 have been measured in MWIR e-APDs with a gain independent excess noise factor of 1.3. This paper reports the application of the mid-wave HgCdTe e-APD for near-IR gated-active/passive imaging. Specifically a 128x128 FPA composed of 40 μm pitch, 4.2 μm to 5 μm cutoff, APD detectors with a custom readout integrated circuit was designed, fabricated, and tested. Median gains as high as 946 at 11 V bias with noise equivalent inputs as low as 0.4 photon were measured at 80 K. A gated imaging demonstration system was designed and built using commercially available parts. High resolution gated imagery out to 9 km was obtained with this system that demonstrated predicted MTF, precision gating, and sub 10 photon sensitivity.
Feasibility assessment of yttrium-90 liver radioembolization imaging using amplitude-based gated PET/CT

PubMed Central

Acuff, Shelley N.; Neveu, Melissa L.; Syed, Mumtaz; Kaman, Austin D.; Fu, Yitong

2018-01-01

Purpose The usage of PET/computed tomography (CT) to monitor hepatocellular carcinoma patients following yttrium-90 (90Y) radioembolization has increased. Respiratory motion causes liver movement, which can be corrected using gating techniques at the expense of added noise. This work examines the use of amplitude-based gating on 90Y-PET/CT and its potential impact on diagnostic integrity. Patients and methods Patients were imaged using PET/CT following 90Y radioembolization. A respiratory band was used to collect respiratory cycle data. Patient data were processed as both standard and motion-corrected images. Regions of interest were drawn and compared using three methods. Activity concentrations were calculated and converted into dose estimates using previously determined and published scaling factors. Diagnostic assessments were performed using a binary scale created from published 90Y-PET/CT image interpretation guidelines. Results Estimates of radiation dose were increased (P<0.05) when using amplitude-gating methods with 90Y PET/CT imaging. Motion-corrected images show increased noise, but the diagnostic determination of success, using the Kao criteria, did not change between static and motion-corrected data. Conclusion Amplitude-gated PET/CT following 90Y radioembolization is feasible and may improve 90Y dose estimates while maintaining diagnostic assessment integrity. PMID:29351124

Photon gating in four-dimensional ultrafast electron microscopy.

PubMed

Hassan, Mohammed T; Liu, Haihua; Baskin, John Spencer; Zewail, Ahmed H

2015-10-20

Ultrafast electron microscopy (UEM) is a pivotal tool for imaging of nanoscale structural dynamics with subparticle resolution on the time scale of atomic motion. Photon-induced near-field electron microscopy (PINEM), a key UEM technique, involves the detection of electrons that have gained energy from a femtosecond optical pulse via photon-electron coupling on nanostructures. PINEM has been applied in various fields of study, from materials science to biological imaging, exploiting the unique spatial, energy, and temporal characteristics of the PINEM electrons gained by interaction with a "single" light pulse. The further potential of photon-gated PINEM electrons in probing ultrafast dynamics of matter and the optical gating of electrons by invoking a "second" optical pulse has previously been proposed and examined theoretically in our group. Here, we experimentally demonstrate this photon-gating technique, and, through diffraction, visualize the phase transition dynamics in vanadium dioxide nanoparticles. With optical gating of PINEM electrons, imaging temporal resolution was improved by a factor of 3 or better, being limited only by the optical pulse widths. This work enables the combination of the high spatial resolution of electron microscopy and the ultrafast temporal response of the optical pulses, which provides a promising approach to attain the resolution of few femtoseconds and attoseconds in UEM.
Photon gating in four-dimensional ultrafast electron microscopy

PubMed Central

Hassan, Mohammed T.; Liu, Haihua; Baskin, John Spencer; Zewail, Ahmed H.

2015-01-01

Ultrafast electron microscopy (UEM) is a pivotal tool for imaging of nanoscale structural dynamics with subparticle resolution on the time scale of atomic motion. Photon-induced near-field electron microscopy (PINEM), a key UEM technique, involves the detection of electrons that have gained energy from a femtosecond optical pulse via photon–electron coupling on nanostructures. PINEM has been applied in various fields of study, from materials science to biological imaging, exploiting the unique spatial, energy, and temporal characteristics of the PINEM electrons gained by interaction with a “single” light pulse. The further potential of photon-gated PINEM electrons in probing ultrafast dynamics of matter and the optical gating of electrons by invoking a “second” optical pulse has previously been proposed and examined theoretically in our group. Here, we experimentally demonstrate this photon-gating technique, and, through diffraction, visualize the phase transition dynamics in vanadium dioxide nanoparticles. With optical gating of PINEM electrons, imaging temporal resolution was improved by a factor of 3 or better, being limited only by the optical pulse widths. This work enables the combination of the high spatial resolution of electron microscopy and the ultrafast temporal response of the optical pulses, which provides a promising approach to attain the resolution of few femtoseconds and attoseconds in UEM. PMID:26438835
Respiratory-gated CT as a tool for the simulation of breathing artifacts in PET and PET/CT.

PubMed

Hamill, J J; Bosmans, G; Dekker, A

2008-02-01

Respiratory motion in PET and PET/CT blurs the images and can cause attenuation-related errors in quantitative parameters such as standard uptake values. In rare instances, this problem even causes localization errors and the disappearance of tumors that should be detectable. Attenuation errors are severe near the diaphragm and can be enhanced when the attenuation correction is based on a CT series acquired during a breath-hold. To quantify the errors and identify the parameters associated with them, the authors performed a simulated PET scan based on respiratory-gated CT studies of five lung cancer patients. Diaphragmatic motion ranged from 8 to 25 mm in the five patients. The CT series were converted to 511-keV attenuation maps which were forward-projected and exponentiated to form sinograms of PET attenuation factors at each phase of respiration. The CT images were also segmented to form a PET object, moving with the same motion as the CT series. In the moving PET object, spherical 20 mm mobile tumors were created in the vicinity of the dome of the liver and immobile 20 mm tumors in the midchest region. The moving PET objects were forward-projected and attenuated, then reconstructed in several ways: phase-matched PET and CT, gated PET with ungated CT, ungated PET with gated CT, and conventional PET. Spatial resolution and statistical noise were not modeled. In each case, tumor uptake recovery factor was defined by comparing the maximum reconstructed pixel value with the known correct value. Mobile 10 and 30 mm tumors were also simulated in the case of a patient with 11 mm of breathing motion. Phase-matched gated PET and CT gave essentially perfect PET reconstructions in the simulation. Gated PET with ungated CT gave tumors of the correct shape, but recovery was too large by an amount that depended on the extent of the motion, as much as 90% for mobile tumors and 60% for immobile tumors. Gated CT with ungated PET resulted in blurred tumors and caused recovery errors between -50% and +75%. Recovery in clinical scans would be 0%-20% lower than stated because spatial resolution was not included in the simulation. Mobile tumors near the dome of the liver were subject to the largest errors in either case. Conventional PET for 20 mm tumors was quantitative in cases of motion less than 15 mm because of canceling errors in blurring and attenuation, but the recovery factors were too low by as much as 30% in cases of motion greater than 15 mm. The 10 mm tumors were blurred by motion to a greater extent, causing a greater SUV underestimation than in the case of 20 mm tumors, and the 30 mm tumors were blurred less. Quantitative PET imaging near the diaphragm requires proper matching of attenuation information to the emission information. The problem of missed tumors near the diaphragm can be reduced by acquiring attenuation-correction information near end expiration. A simple PET/CT protocol requiring no gating equipment also addresses this problem.
Determinants of maternal health care services utilization in Pakistan: evidence from Pakistan demographic and health survey, 2012-13.

PubMed

Zakar, Rubeena; Zakar, Muhammad Zakria; Aqil, Nauman; Chaudhry, Ashraf; Nasrullah, Muazzam

2017-04-01

The aim of this study was to determine the association between maternal utilisation of health-care services and socio-demographic factors among reproductive-age women in Pakistan. We used the sample of ever-married reproductive-age women (n = 7446) from the Pakistan Demographic and Health Survey (PDHS), 2012-13. We measured maternal utilisation of health-care services by using three dependent variables: number of antenatal care (ANC) visits, delivery assistance by a skilled health provider, and delivery in a health-care facility. Around 36.6% of women had made four or more ANC visits, 59% had received assistance from skilled health providers during delivery, and 55.3% had given birth in a health-care facility. On multivariable logistic regression, all three variables were positively associated with education and wealth, and negatively associated with birth order and women's autonomy. Policymakers and health planners may use our findings to develop efficient strategies, particularly for uneducated women and those with poor economic status, to improve the utilisation of maternal health-care services in Pakistan.
A simple solution to the problem of effective utilisation of the target material for pulsed laser deposition of thin films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuzanyan, A S; Kuzanyan, A A; Petrosyan, V A

The factors determining the efficiency of the target material utilisation for pulsed laser deposition of films are considered. The target volume is calculated, which is evaporated in the ablation process by the focused laser radiation having a rectangular form. The new device is suggested and developed for obtaining thin films by the method of laser deposition, which is specific in the employment of a simple optical system mounted outside a deposition chamber that comprises two lenses and the diaphragm and focuses the laser beam onto a target in the form of a sector-like spot. Thin films of CuO and YBaCuOmore » were deposited with this device. Several deposition cycles revealed that the target material is consumed uniformly from the entire surface of the target. A maximal spread of the target thickness was not greater than ±2% both prior to deposition and after it. The device designed provides a high coefficient of the target material utilisation efficiency. (laser deposition of thin films)« less
Further characterization of the effect of ethanol on voltage-gated Ca(2+) channel function in developing CA3 hippocampal pyramidal neurons.

PubMed

Morton, Russell A; Valenzuela, C Fernando

2016-02-15

Developmental ethanol exposure damages the hippocampus, a brain region involved in learning and memory. Alterations in synaptic transmission and plasticity may play a role in this effect of ethanol. We previously reported that acute and repeated exposure to ethanol during the third trimester-equivalent inhibits long-term potentiation of GABAA receptor-dependent synaptic currents in CA3 pyramidal neurons through a mechanism that depends on retrograde release of brain-derived neurotrophic factor driven by activation of voltage-gated Ca(2+) channels (Zucca and Valenzuela, 2010). We found evidence indicating that voltage-gated Ca(2+) channels are inhibited in the presence of ethanol, an effect that may play a role in its mechanism of action. Here, we further investigated the acute effect of ethanol on the function of voltage-gated Ca(2+) channels in CA3 pyramidal neurons using Ca(2+) imaging techniques. These experiments revealed that acute ethanol exposure inhibits voltage-gated Ca(2+) channels both in somatic and proximal dendritic compartments. To investigate the long-term consequences of ethanol on voltage-gated Ca(2+) channels, we used patch-clamp electrophysiological techniques to assess the function of L-type voltage-gated Ca(2+) channels during and following ten days of vapor ethanol exposure. During ethanol withdrawal periods, the function of these channels was not significantly affected by vapor chamber exposure. Taken together with our previous findings, our results suggest that 3(rd) trimester-equivalent ethanol exposure transiently inhibits L-type voltage-gated Ca(2+) channel function in CA3 pyramidal neurons and that compensatory mechanisms restore their function during ethanol withdrawal. Transient inhibition of these channels by ethanol may be, in part, responsible for the hippocampal abnormalities associated with developmental exposure to this agent. Copyright © 2015 Elsevier B.V. All rights reserved.
The effect of respiratory induced density variations on non-TOF PET quantitation in the lung.

PubMed

Holman, Beverley F; Cuplov, Vesna; Hutton, Brian F; Groves, Ashley M; Thielemans, Kris

2016-04-21

Accurate PET quantitation requires a matched attenuation map. Obtaining matched CT attenuation maps in the thorax is difficult due to the respiratory cycle which causes both motion and density changes. Unlike with motion, little attention has been given to the effects of density changes in the lung on PET quantitation. This work aims to explore the extent of the errors caused by pulmonary density attenuation map mismatch on dynamic and static parameter estimates. Dynamic XCAT phantoms were utilised using clinically relevant (18)F-FDG and (18)F-FMISO time activity curves for all organs within the thorax to estimate the expected parameter errors. The simulations were then validated with PET data from 5 patients suffering from idiopathic pulmonary fibrosis who underwent PET/Cine-CT. The PET data were reconstructed with three gates obtained from the Cine-CT and the average Cine-CT. The lung TACs clearly displayed differences between true and measured curves with error depending on global activity distribution at the time of measurement. The density errors from using a mismatched attenuation map were found to have a considerable impact on PET quantitative accuracy. Maximum errors due to density mismatch were found to be as high as 25% in the XCAT simulation. Differences in patient derived kinetic parameter estimates and static concentration between the extreme gates were found to be as high as 31% and 14%, respectively. Overall our results show that respiratory associated density errors in the attenuation map affect quantitation throughout the lung, not just regions near boundaries. The extent of this error is dependent on the activity distribution in the thorax and hence on the tracer and time of acquisition. Consequently there may be a significant impact on estimated kinetic parameters throughout the lung.
Hybrid nanowire ion-to-electron transducers for integrated bioelectronic circuitry (Conference Presentation)

NASA Astrophysics Data System (ADS)

Carrad, Damon J.; Mostert, Bernard; Meredith, Paul; Micolich, Adam P.

2016-09-01

A key task in bioelectronics is the transduction between ionic/protonic signals and electronic signals at high fidelity. This is a considerable challenge since the two carrier types exhibit intrinsically different physics. We present our work on a new class of organic-inorganic transducing interface utilising semiconducting InAs and GaAs nanowires directly gated with a proton transporting hygroscopic polymer consisting of undoped polyethylene oxide (PEO) patterned to nanoscale dimensions by a newly developed electron-beam lithography process [1]. Remarkably, we find our undoped PEO polymer electrolyte gate dielectric [2] gives equivalent electrical performance to the more traditionally used LiClO4-doped PEO [3], with an ionic conductivity three orders of magnitude higher than previously reported for undoped PEO [4]. The observed behaviour is consistent with proton conduction in PEO. We attribute our undoped PEO-based devices' performance to the small external surface and high surface-to-volume ratio of both the nanowire conducting channel and patterned PEO dielectric in our devices, as well as the enhanced hydration afforded by device processing and atmospheric conditions. In addition to studying the basic transducing mechanisms, we also demonstrate high-fidelity ionic to electronic conversion of a.c. signals at frequencies up to 50 Hz. Moreover, by combining complementary n- and p-type transducers we demonstrate functional hybrid ionic-electronic circuits can achieve logic (NOT operation), and with some further engineering of the nanowire contacts, potentially also amplification. Our device structures have significant potential to be scaled towards realising integrated bioelectronic circuitry. [1] D.J. Carrad et al., Nano Letters 14, 94 (2014). [2] D.J. Carrad et al., Manuscript in preparation (2016). [3] S.H. Kim et al., Advanced Materials 25, 1822 (2013). [4] S.K. Fullerton-Shirey et al., Macromolecules 42, 2142 (2009).
The effect of respiratory induced density variations on non-TOF PET quantitation in the lung

NASA Astrophysics Data System (ADS)

Holman, Beverley F.; Cuplov, Vesna; Hutton, Brian F.; Groves, Ashley M.; Thielemans, Kris

2016-04-01

Accurate PET quantitation requires a matched attenuation map. Obtaining matched CT attenuation maps in the thorax is difficult due to the respiratory cycle which causes both motion and density changes. Unlike with motion, little attention has been given to the effects of density changes in the lung on PET quantitation. This work aims to explore the extent of the errors caused by pulmonary density attenuation map mismatch on dynamic and static parameter estimates. Dynamic XCAT phantoms were utilised using clinically relevant 18F-FDG and 18F-FMISO time activity curves for all organs within the thorax to estimate the expected parameter errors. The simulations were then validated with PET data from 5 patients suffering from idiopathic pulmonary fibrosis who underwent PET/Cine-CT. The PET data were reconstructed with three gates obtained from the Cine-CT and the average Cine-CT. The lung TACs clearly displayed differences between true and measured curves with error depending on global activity distribution at the time of measurement. The density errors from using a mismatched attenuation map were found to have a considerable impact on PET quantitative accuracy. Maximum errors due to density mismatch were found to be as high as 25% in the XCAT simulation. Differences in patient derived kinetic parameter estimates and static concentration between the extreme gates were found to be as high as 31% and 14%, respectively. Overall our results show that respiratory associated density errors in the attenuation map affect quantitation throughout the lung, not just regions near boundaries. The extent of this error is dependent on the activity distribution in the thorax and hence on the tracer and time of acquisition. Consequently there may be a significant impact on estimated kinetic parameters throughout the lung.
Accuracy Verification of Respiratory-gated Radiotherapy that Combines the Respiration-Monitoring Device and Respiratory-gated System.

PubMed

Shintani, Naoya; Monzen, Hajime; Tamura, Masaya; Asai, Yoshiyuki; Shimomura, Kouhei; Matsumoto, Kenji; Okumura, Masahiko; Nishimura, Yasumasa

2016-01-01

The purpose of this study is to evaluate the mechanical accuracy of a respiratory-gated radiation system that combines the Linear Indicator-equipped Abches respiration-monitoring device and the Varian Real-time Position Management system (LI-RPM system). This combined configuration, implemented for the first time in Japan, was compared with the stand-alone Varian RPM system (RPM system). The delay times, dose profiles, and output waveforms of the LI-RPM and RPM systems were evaluated using a self-produced dynamic phantom. The delay times for the LI-RPM and RPM systems were both 0.1 s for 4 s and 8 s test periods. The corresponding output waveform correlation factors (R 2 ) for the 4 s and 8 s test periods were 0.9981 and 0.9975, respectively. No difference was observed in the dose profiles of the two systems. Thus, the present results indicate that the proposed LI-RPM combined respiratory-gated radiation system has similar properties to the RPM system. However, it offers several advantages in terms of its versatility, including its alignment assistance capabilities for non-coplanar treatments.
Model-based restoration using light vein for range-gated imaging systems.

PubMed

Wang, Canjin; Sun, Tao; Wang, Tingfeng; Wang, Rui; Guo, Jin; Tian, Yuzhen

2016-09-10

The images captured by an airborne range-gated imaging system are degraded by many factors, such as light scattering, noise, defocus of the optical system, atmospheric disturbances, platform vibrations, and so on. The characteristics of low illumination, few details, and high noise make the state-of-the-art restoration method fail. In this paper, we present a restoration method especially for range-gated imaging systems. The degradation process is divided into two parts: the static part and the dynamic part. For the static part, we establish the physical model of the imaging system according to the laser transmission theory, and estimate the static point spread function (PSF). For the dynamic part, a so-called light vein feature extraction method is presented to estimate the fuzzy parameter of the atmospheric disturbance and platform movement, which make contributions to the dynamic PSF. Finally, combined with the static and dynamic PSF, an iterative updating framework is used to restore the image. Compared with the state-of-the-art methods, the proposed method can effectively suppress ringing artifacts and achieve better performance in a range-gated imaging system.
Access and utilisation of maternity care for disabled women who experience domestic abuse: a systematic review

PubMed Central

2014-01-01

Background Although disabled women are significantly more likely to experience domestic abuse during pregnancy than non-disabled women, very little is known about how maternity care access and utilisation is affected by the co-existence of disability and domestic abuse. This systematic review of the literature explored how domestic abuse impacts upon disabled women’s access to maternity services. Methods Eleven articles were identified through a search of six electronic databases and data were analysed to identify: the factors that facilitate or compromise access to care; the consequences of inadequate care for pregnant women’s health and wellbeing; and the effectiveness of existing strategies for improvement. Results Findings indicate that a mental health diagnosis, poor relationships with health professionals and environmental barriers can compromise women’s utilisation of maternity services. Domestic abuse can both compromise, and catalyse, access to services and social support is a positive factor when accessing care. Delayed and inadequate care has adverse effects on women’s physical and psychological health, however further research is required to fully explore the nature and extent of these consequences. Only one study identified strategies currently being used to improve access to services for disabled women experiencing abuse. Conclusions Based upon the barriers and facilitators identified within the review, we suggest that future strategies for improvement should focus on: understanding women’s reasons for accessing care; fostering positive relationships; being women-centred; promoting environmental accessibility; and improving the strength of the evidence base. PMID:25029907
Single-electron thermal devices coupled to a mesoscopic gate

NASA Astrophysics Data System (ADS)

Sánchez, Rafael; Thierschmann, Holger; Molenkamp, Laurens W.

2017-11-01

We theoretically investigate the propagation of heat currents in a three-terminal quantum dot engine. Electron-electron interactions introduce state-dependent processes which can be resolved by energy-dependent tunneling rates. We identify the relevant transitions which define the operation of the system as a thermal transistor or a thermal diode. In the former case, thermal-induced charge fluctuations in the gate dot modify the thermal currents in the conductor with suppressed heat injection, resulting in huge amplification factors and the possible gating with arbitrarily low energy cost. In the latter case, enhanced correlations of the state-selective tunneling transitions redistribute heat flows giving high rectification coefficients and the unexpected cooling of one conductor terminal by heating the other one. We propose quantum dot arrays as a possible way to achieve the extreme tunneling asymmetries required for the different operations.
Quantum Simulation of Tunneling in Small Systems

PubMed Central

Sornborger, Andrew T.

2012-01-01

A number of quantum algorithms have been performed on small quantum computers; these include Shor's prime factorization algorithm, error correction, Grover's search algorithm and a number of analog and digital quantum simulations. Because of the number of gates and qubits necessary, however, digital quantum particle simulations remain untested. A contributing factor to the system size required is the number of ancillary qubits needed to implement matrix exponentials of the potential operator. Here, we show that a set of tunneling problems may be investigated with no ancillary qubits and a cost of one single-qubit operator per time step for the potential evolution, eliminating at least half of the quantum gates required for the algorithm and more than that in the general case. Such simulations are within reach of current quantum computer architectures. PMID:22916333
Epidermal growth factor upregulates motility of Mat-LyLu rat prostate cancer cells partially via voltage-gated Na+ channel activity

PubMed Central

Ding, Yanning; Brackenbury, William J.; Onganer, Pinar U.; Montano, Ximena; Porter, Louise M.; Bates, Lucy F.; Djamgoz, Mustafa B. A.

2014-01-01

The main aim of this investigation was to determine whether a functional relationship existed between epidermal growth factor (EGF) and voltage-gated sodium channel (VGSC) upregulation, both associated with strongly metastatic prostate cancer cells. Incubation with EGF for 24 h more than doubled VGSC current density. Similar treatment with EGF significantly and dose-dependently enhanced the cells’ migration through Transwell filters. Both the patch clamp recordings and the migration assay suggested that endogenous EGF played a similar role. Importantly, co-application of EGF and tetrodotoxin, a highly selective VGSC blocker, abolished 65% of the potentiating effect of EGF. It is suggested that a significant portion of the EGF-induced enhancement of migration occurred via VGSC activity. PMID:17960590
Systems-on-chip approach for real-time simulation of wheel-rail contact laws

NASA Astrophysics Data System (ADS)

Mei, T. X.; Zhou, Y. J.

2013-04-01

This paper presents the development of a systems-on-chip approach to speed up the simulation of wheel-rail contact laws, which can be used to reduce the requirement for high-performance computers and enable simulation in real time for the use of hardware-in-loop for experimental studies of the latest vehicle dynamic and control technologies. The wheel-rail contact laws are implemented using a field programmable gate array (FPGA) device with a design that substantially outperforms modern general-purpose PC platforms or fixed architecture digital signal processor devices in terms of processing time, configuration flexibility and cost. In order to utilise the FPGA's parallel-processing capability, the operations in the contact laws algorithms are arranged in a parallel manner and multi-contact patches are tackled simultaneously in the design. The interface between the FPGA device and the host PC is achieved by using a high-throughput and low-latency Ethernet link. The development is based on FASTSIM algorithms, although the design can be adapted and expanded for even more computationally demanding tasks.
Effects of the distribution density of a biomass combined heat and power plant network on heat utilisation efficiency in village-town systems.

PubMed

Zhang, Yifei; Kang, Jian

2017-11-01

The building of biomass combined heat and power (CHP) plants is an effective means of developing biomass energy because they can satisfy demands for winter heating and electricity consumption. The purpose of this study was to analyse the effect of the distribution density of a biomass CHP plant network on heat utilisation efficiency in a village-town system. The distribution density is determined based on the heat transmission threshold, and the heat utilisation efficiency is determined based on the heat demand distribution, heat output efficiency, and heat transmission loss. The objective of this study was to ascertain the optimal value for the heat transmission threshold using a multi-scheme comparison based on an analysis of these factors. To this end, a model of a biomass CHP plant network was built using geographic information system tools to simulate and generate three planning schemes with different heat transmission thresholds (6, 8, and 10 km) according to the heat demand distribution. The heat utilisation efficiencies of these planning schemes were then compared by calculating the gross power, heat output efficiency, and heat transmission loss of the biomass CHP plant for each scenario. This multi-scheme comparison yielded the following results: when the heat transmission threshold was low, the distribution density of the biomass CHP plant network was high and the biomass CHP plants tended to be relatively small. In contrast, when the heat transmission threshold was high, the distribution density of the network was low and the biomass CHP plants tended to be relatively large. When the heat transmission threshold was 8 km, the distribution density of the biomass CHP plant network was optimised for efficient heat utilisation. To promote the development of renewable energy sources, a planning scheme for a biomass CHP plant network that maximises heat utilisation efficiency can be obtained using the optimal heat transmission threshold and the nonlinearity coefficient for local roads. Copyright © 2017 Elsevier Ltd. All rights reserved.
On the role of thermal backbone fluctuations in myoglobin ligand gate dynamics.

PubMed

Krokhotin, Andrey; Niemi, Antti J; Peng, Xubiao

2013-05-07

We construct an energy function that describes the crystallographic structure of sperm whale myoglobin backbone. As a model in our construction, we use the Protein Data Bank entry 1ABS that has been measured at liquid helium temperature. Consequently, the thermal B-factor fluctuations are very small, which is an advantage in our construction. The energy function that we utilize resembles that of the discrete nonlinear Schrödinger equation. Likewise, ours supports topological solitons as local minimum energy configurations. We describe the 1ABS backbone in terms of topological solitons with a precision that deviates from 1ABS by an average root-mean-square distance, which is less than the experimentally observed Debye-Waller B-factor fluctuation distance. We then subject the topological multi-soliton solution to extensive numerical heating and cooling experiments, over a very wide range of temperatures. We concentrate in particular to temperatures above 300 K and below the Θ-point unfolding temperature, which is around 348 K. We confirm that the behavior of the topological multi-soliton is fully consistent with Anfinsen's thermodynamic principle, up to very high temperatures. We observe that the structure responds to an increase of temperature consistently in a very similar manner. This enables us to characterize the onset of thermally induced conformational changes in terms of three distinct backbone ligand gates. One of the gates is made of the helix F and the helix E. The two other gates are chosen similarly, when open they provide a direct access route for a ligand to reach the heme. We find that out of the three gates we investigate, the one which is formed by helices B and G is the most sensitive to thermally induced conformational changes. Our approach provides a novel perspective to the important problem of ligand entry and exit.
On the role of thermal backbone fluctuations in myoglobin ligand gate dynamics

NASA Astrophysics Data System (ADS)

Krokhotin, Andrey; Niemi, Antti J.; Peng, Xubiao

2013-05-01

We construct an energy function that describes the crystallographic structure of sperm whale myoglobin backbone. As a model in our construction, we use the Protein Data Bank entry 1ABS that has been measured at liquid helium temperature. Consequently, the thermal B-factor fluctuations are very small, which is an advantage in our construction. The energy function that we utilize resembles that of the discrete nonlinear Schrödinger equation. Likewise, ours supports topological solitons as local minimum energy configurations. We describe the 1ABS backbone in terms of topological solitons with a precision that deviates from 1ABS by an average root-mean-square distance, which is less than the experimentally observed Debye-Waller B-factor fluctuation distance. We then subject the topological multi-soliton solution to extensive numerical heating and cooling experiments, over a very wide range of temperatures. We concentrate in particular to temperatures above 300 K and below the Θ-point unfolding temperature, which is around 348 K. We confirm that the behavior of the topological multi-soliton is fully consistent with Anfinsen's thermodynamic principle, up to very high temperatures. We observe that the structure responds to an increase of temperature consistently in a very similar manner. This enables us to characterize the onset of thermally induced conformational changes in terms of three distinct backbone ligand gates. One of the gates is made of the helix F and the helix E. The two other gates are chosen similarly, when open they provide a direct access route for a ligand to reach the heme. We find that out of the three gates we investigate, the one which is formed by helices B and G is the most sensitive to thermally induced conformational changes. Our approach provides a novel perspective to the important problem of ligand entry and exit.
Centrally Determined Standardization of Flow Cytometry Methods Reduces Interlaboratory Variation in a Prospective Multicenter Study

PubMed Central

Westera, Liset; van Viegen, Tanja; Jeyarajah, Jenny; Azad, Azar; Bilsborough, Janine; van den Brink, Gijs R; Cremer, Jonathan; Danese, Silvio; D'Haens, Geert; Eckmann, Lars; Faubion, William; Filice, Melissa; Korf, Hannelie; McGovern, Dermot; Panes, Julian; Salas, Azucena; Sandborn, William J; Silverberg, Mark S; Smith, Michelle I; Vermeire, Severine; Vetrano, Stefania; Shackelton, Lisa M; Stitt, Larry; Jairath, Vipul; Levesque, Barrett G; Spencer, David M; Feagan, Brian G; Vande Casteele, Niels

2017-01-01

Objectives: Flow cytometry (FC) aids in characterization of cellular and molecular factors involved in pathologic immune responses. Although FC has potential to facilitate early drug development in inflammatory bowel disease, interlaboratory variability limits its use in multicenter trials. Standardization of methods may address this limitation. We compared variability in FC-aided quantitation of T-cell responses across international laboratories using three analytical strategies. Methods: Peripheral blood mononuclear cells (PBMCs) were isolated from three healthy donors, stimulated with phorbol 12-myristate 13-acetate and ionomycin at a central laboratory, fixed, frozen, and shipped to seven international laboratories. Permeabilization and staining was performed in triplicate at each laboratory using a common protocol and centrally provided reagents. Gating was performed using local gating with a local strategy (LGLS), local gating with a central strategy (LGCS), and central gating (CG). Median cell percentages were calculated across triplicates and donors, and reported for each condition and strategy. The coefficient of variation (CV) was calculated across laboratories. Between-strategy comparisons were made using a two-way analysis of variance adjusting for donor. Results: Mean interlaboratory CV ranged from 1.8 to 102.1% depending on cell population and gating strategy (LGLS, 4.4–102.1% LGCS, 10.9–65.6% CG, 1.8–20.9%). Mean interlaboratory CV differed significantly across strategies and was consistently lower with CG. Conclusions: Central gating was the only strategy with mean CVs consistently lower than 25%, which is a proposed standard for pharmacodynamic and exploratory biomarker assays. PMID:29095427

An Integrated Gate Turnaround Management Concept Leveraging Big Data Analytics for NAS Performance Improvements

NASA Technical Reports Server (NTRS)

Chung, William W.; Ingram, Carla D.; Ahlquist, Douglas Kurt; Chachad, Girish H.

2016-01-01

"Gate Turnaround" plays a key role in the National Air Space (NAS) gate-to-gate performance by receiving aircraft when they reach their destination airport, and delivering aircraft into the NAS upon departing from the gate and subsequent takeoff. The time spent at the gate in meeting the planned departure time is influenced by many factors and often with considerable uncertainties. Uncertainties such as weather, early or late arrivals, disembarking and boarding passengers, unloading/reloading cargo, aircraft logistics/maintenance services and ground handling, traffic in ramp and movement areas for taxi-in and taxi-out, and departure queue management for takeoff are likely encountered on the daily basis. The Integrated Gate Turnaround Management (IGTM) concept is leveraging relevant historical data to support optimization of the gate operations, which include arrival, at the gate, departure based on constraints (e.g., available gates at the arrival, ground crew and equipment for the gate turnaround, and over capacity demand upon departure), and collaborative decision-making. The IGTM concept provides effective information services and decision tools to the stakeholders, such as airline dispatchers, gate agents, airport operators, ramp controllers, and air traffic control (ATC) traffic managers and ground controllers to mitigate uncertainties arising from both nominal and off-nominal airport gate operations. IGTM will provide NAS stakeholders customized decision making tools through a User Interface (UI) by leveraging historical data (Big Data), net-enabled Air Traffic Management (ATM) live data, and analytics according to dependencies among NAS parameters for the stakeholders to manage and optimize the NAS performance in the gate turnaround domain. The application will give stakeholders predictable results based on the past and current NAS performance according to selected decision trees through the UI. The predictable results are generated based on analysis of the unique airport attributes (e.g., runway, taxiway, terminal, and gate configurations and tenants), and combined statistics from past data and live data based on a specific set of ATM concept-of-operations (ConOps) and operational parameters via systems analysis using an analytic network learning model. The IGTM tool will then bound the uncertainties that arise from nominal and off-nominal operational conditions with direct assessment of the gate turnaround status and the impact of a certain operational decision on the NAS performance, and provide a set of recommended actions to optimize the NAS performance by allowing stakeholders to take mitigation actions to reduce uncertainty and time deviation of planned operational events. An IGTM prototype was developed at NASA Ames Simulation Laboratories (SimLabs) to demonstrate the benefits and applicability of the concept. A data network, using the System Wide Information Management (SWIM)-like messaging application using the ActiveMQ message service, was connected to the simulated data warehouse, scheduled flight plans, a fast-time airport simulator, and a graphic UI. A fast-time simulation was integrated with the data warehouse or Big Data/Analytics (BAI), scheduled flight plans from Aeronautical Operational Control AOC, IGTM Controller, and a UI via a SWIM-like data messaging network using the ActiveMQ message service, illustrated in Figure 1, to demonstrate selected use-cases showing the benefits of the IGTM concept on the NAS performance.
Utilisation of antihyperglycaemic drugs in ten European countries: different developments and different levels.

PubMed

Melander, A; Folino-Gallo, P; Walley, T; Schwabe, U; Groop, P-H; Klaukka, T; Vallano, A; Laporte, J-R; Gallego, M R; Schiappa, M; Røder, M; Kampmann, J P; de Swaef, A; Aberg, M; Månsson, N-O; Lindblad, U

2006-09-01

The aim of this study was to compare developments in the utilisation of antihyperglycaemic drugs (AHGDs) in ten European countries. Data on the yearly utilisation of insulin and oral AHGDs were collected from public registers in Denmark, Finland, Norway, Sweden, Belgium, England, Germany, Italy, Portugal and Spain, and were expressed as defined daily doses per 1,000 inhabitants per day. Total AGHD utilisation increased everywhere, but at different rates and levels. Insulin utilisation doubled in England and Germany, but hardly changed in Belgium, Portugal or Italy. Sulfonylurea utilisation doubled in Spain, England and Denmark but was reduced in Germany and Sweden. Metformin utilisation increased greatly everywhere. There were two- to three-fold differences in AHGD utilisation even between neighbouring countries. In Finland, there were more users of both insulin (+120%) and oral AHGDs (+80%) than in Denmark, and the daily oral AHGD doses were higher. In Denmark and Sweden, AHGD utilisation was equal in subjects aged <45 years, but in those >or=45 years of age, both insulin and oral AHGD utilisation were twice as high in Sweden. The ubiquitous increase in AHGD utilisation, particularly metformin, seems logical, considering the increasing prevalence of type 2 diabetes and the results of the UK Prospective Diabetes Study. However, the large differences even between neighbouring countries are more difficult to explain, and suggest different habits and attitudes in terms of screening and management of type 2 diabetes.
Health and health care utilisation among asylum seekers and refugees in the Netherlands: design of a study

PubMed Central

Gerritsen, Annette AM; Bramsen, Inge; Devillé, Walter; van Willigen, Loes HM; Hovens, Johannes E; van der Ploeg, Henk M

2004-01-01

Background This article discusses the design of a study on the prevalence of health problems (both physical and mental) and the utilisation of health care services among asylum seekers and refugees in the Netherlands, including factors that may be related to their health and their utilisation of these services. Methods/Design The study will include random samples of adult asylum seekers and refugees from Afghanistan, Iran and Somali (total planned sample of 600), as these are among the largest groups within the reception centres and municipalities in the Netherlands. The questionnaire that will be used will include questions on physical health (chronic and acute diseases and somatization), mental health (Hopkins Symptoms Checklist-25 and Harvard Trauma Questionnaire), utilisation of health care services, pre- and post-migratory traumatic experiences, life-style, acculturation, social support and socio-demographic background. The questionnaire has gone through a translation process (translation and back-translation, several checks and a pilot-study) and cross-cultural adaptation. Respondents will be interviewed by bilingual and bicultural interviewers who will be specifically trained for this purpose. This article discusses the selection of the study population, the chosen outcome measures, the translation and cross-cultural adaptation of the measurement instrument, the training of the interviewers and the practical execution of the study. The information provided may be useful for other researchers in this relatively new field of epidemiological research among various groups of asylum seekers and refugees. PMID:15070416
Health and health care utilisation among asylum seekers and refugees in the Netherlands: design of a study.

PubMed

Gerritsen, Annette A M; Bramsen, Inge; Devillé, Walter; van Willigen, Loes H M; Hovens, Johannes E; van der Ploeg, Henk M

2004-03-10

This article discusses the design of a study on the prevalence of health problems (both physical and mental) and the utilisation of health care services among asylum seekers and refugees in the Netherlands, including factors that may be related to their health and their utilisation of these services. The study will include random samples of adult asylum seekers and refugees from Afghanistan, Iran and Somali (total planned sample of 600), as these are among the largest groups within the reception centres and municipalities in the Netherlands. The questionnaire that will be used will include questions on physical health (chronic and acute diseases and somatization), mental health (Hopkins Symptoms Checklist-25 and Harvard Trauma Questionnaire), utilisation of health care services, pre- and post-migratory traumatic experiences, life-style, acculturation, social support and socio-demographic background. The questionnaire has gone through a translation process (translation and back-translation, several checks and a pilot-study) and cross-cultural adaptation. Respondents will be interviewed by bilingual and bicultural interviewers who will be specifically trained for this purpose. This article discusses the selection of the study population, the chosen outcome measures, the translation and cross-cultural adaptation of the measurement instrument, the training of the interviewers and the practical execution of the study. The information provided may be useful for other researchers in this relatively new field of epidemiological research among various groups of asylum seekers and refugees.
The Utilisation of Music by Casino Managers: An Interview Study.

PubMed

Bramley, Stephanie; Dibben, Nicola; Rowe, Richard

2016-12-01

Music is ubiquitous in retail and commercial environments, with some managers believing that music can enhance the customer experience, increase footfall and sales and improve consumer satisfaction. Casino gambling is popular in the United Kingdom and anecdotal evidence suggests that music is often present. However, little is known about the rationale for music use from the perspective of casino managers. In this study semi-structured interviews were conducted with five casino managers to establish their motivations for utilising music, the factors informing their choice of music and the extent to which music is used with the intention of influencing gambling behaviour. Results showed that casino managers utilised two types of music-recorded background music, often sourced via external music supply companies and live music. Live music was often situated away from the gaming floor and used primarily to accompany participation in non-gambling activities. Recorded background music was not used with the direct aim of influencing customers' gambling behaviour, but to create the right atmosphere for gambling and to promote certain moods within the casinos. To achieve these aims casino managers manipulated the tempo, volume and genre of the recorded background music. Casino managers also reported that some gamblers listen to music via portable music players, possibly with the intention of customising their gambling experience. This study is unique as it has provided a first-hand account of casino managers' implicit theories with regards to why they utilise music and the roles which music is considered to fulfil in casinos.
Health service utilisation of rural-to-urban migrants in Guangzhou, China: does employment status matter?

PubMed

Song, Xiaolei; Zou, Guanyang; Chen, Wen; Han, Siqi; Zou, Xia; Ling, Li

2017-01-01

To describe the self-reported health status and service utilisation of employed, retired and unemployed migrants in Guangzhou, a megacity in southern China. A cross-sectional study adapted from the National Health Service Survey was conducted between September and December in 2014. Based on the distribution of occupation of migrants, multistage sampling was used to recruit individuals. Logistic regression was applied to explore the factors influencing their service utilisation. Of 2906 respondents, 76.6% were employed, 9.2% retired and 14.2% unemployed. Only 8.1% reported having an illness in the previous 2 weeks, and 6.5% reported having been hospitalised in the previous year. Employed migrants had the lowest recent physician consultation rate (3.4%) and the lowest annual hospitalisation rate (4.5%) (P < 0.05); unemployed migrants had the highest rates (6.8% and 14.5% respectively, P < 0.05). Retired migrants were more likely to return to their hometown for health care (8.6%) than employed (1.5%) and unemployed migrants (3.4%) (P < 0.05). After adjusting for age and gender, employment status remained significant in explaining the recent two-week treatment-seeking behaviour of migrants (P < 0.05). Disparity of service utilisation continues to be a problem for migrants due to the poor health awareness, lack of time and inconvenience of medical insurance reimbursement. Employed migrants make the least use of health services. © 2016 John Wiley & Sons Ltd.
High-resolution depth profiling using a range-gated CMOS SPAD quanta image sensor.

PubMed

Ren, Ximing; Connolly, Peter W R; Halimi, Abderrahim; Altmann, Yoann; McLaughlin, Stephen; Gyongy, Istvan; Henderson, Robert K; Buller, Gerald S

2018-03-05

A CMOS single-photon avalanche diode (SPAD) quanta image sensor is used to reconstruct depth and intensity profiles when operating in a range-gated mode used in conjunction with pulsed laser illumination. By designing the CMOS SPAD array to acquire photons within a pre-determined temporal gate, the need for timing circuitry was avoided and it was therefore possible to have an enhanced fill factor (61% in this case) and a frame rate (100,000 frames per second) that is more difficult to achieve in a SPAD array which uses time-correlated single-photon counting. When coupled with appropriate image reconstruction algorithms, millimeter resolution depth profiles were achieved by iterating through a sequence of temporal delay steps in synchronization with laser illumination pulses. For photon data with high signal-to-noise ratios, depth images with millimeter scale depth uncertainty can be estimated using a standard cross-correlation approach. To enhance the estimation of depth and intensity images in the sparse photon regime, we used a bespoke clustering-based image restoration strategy, taking into account the binomial statistics of the photon data and non-local spatial correlations within the scene. For sparse photon data with total exposure times of 75 ms or less, the bespoke algorithm can reconstruct depth images with millimeter scale depth uncertainty at a stand-off distance of approximately 2 meters. We demonstrate a new approach to single-photon depth and intensity profiling using different target scenes, taking full advantage of the high fill-factor, high frame rate and large array format of this range-gated CMOS SPAD array.
Identifying interacting proteins of a Caenorhabditis elegans voltage-gated chloride channel CLH-1 using GFP-Trap and mass spectrometry.

PubMed

Zhou, Zi-Liang; Jiang, Jing; Yin, Jiang-An; Cai, Shi-Qing

2014-06-25

Chloride channels belong to a superfamily of ion channels that permit passive passage of anions, mainly chloride, across cell membrane. They play a variety of important physiological roles in regulation of cytosolic pH, cell volume homeostasis, organic solute transport, cell migration, cell proliferation, and differentiation. However, little is known about the functional regulation of these channels. In this study, we generated an integrated transgenic worm strain expressing green fluorescence protein (GFP) fused CLC-type chloride channel 1 (CLH-1::GFP), a voltage-gated chloride channel in Caenorhabditis elegans (C. elegans). CLH-1::GFP was expressed in some unidentified head neurons and posterior intestinal cells of C. elegans. Interacting proteins of CLH-1::GFP were purified by GFP-Trap, a novel system for efficient isolation of GFP fusion proteins and their interacting factors. Mass spectrometry (MS) analysis revealed that a total of 27 high probability interacting proteins were co-trapped with CLHp-1::GFP. Biochemical evidence showed that eukaryotic translation elongation factor 1 (EEF-1), one of these co-trapped proteins identified by MS, physically interacted with CLH-1, in consistent with GFP-Trap experiments. Further immunostaining data revealed that the protein level of CLH-1 was significantly increased upon co-expression with EEF-1. These results suggest that the combination of GFP-Trap purification with MS is an excellent tool to identify novel interacting proteins of voltage-gated chloride channels in C. elegans. Our data also show that EEF-1 is a regulator of voltage-gated chloride channel CLH-1.
Low-dose cardio-respiratory phase-correlated cone-beam micro-CT of small animals.

PubMed

Sawall, Stefan; Bergner, Frank; Lapp, Robert; Mronz, Markus; Karolczak, Marek; Hess, Andreas; Kachelriess, Marc

2011-03-01

Micro-CT imaging of animal hearts typically requires a double gating procedure because scans during a breath-hold are not possible due to the long scan times and the high respiratory rates, Simultaneous respiratory and cardiac gating can either be done prospectively or retrospectively. True five-dimensional information can be either retrieved with retrospective gating or with prospective gating if several prospective gates are acquired. In any case, the amount of information available to reconstruct one volume for a given respiratory and cardiac phase is orders of magnitud lower than the total amount of information acquired. For example, the reconstruction of a volume from a 10% wide respiratory and a 20% wide cardiac window uses only 2% of the data acquired. Achieving a similar image quality as a nongated scan would therefore require to increase the amount of data and thereby the dose to the animal by up to a factor of 50. To achieve the goal of low-dose phase-correlated (LDPC) imaging, the authors propose to use a highly efficient combination of slightly modified existing algorithms. In particular, the authors developed a variant of the McKinnon-Bates image reconstruction algorithm and combined it with bilateral filtering in up to five dimensions to significantly reduce image noise without impairing spatial or temporal resolution. The preliminary results indicate that the proposed LDPC reconstruction method typically reduces image noise by a factor of up to 6 (e.g., from 170 to 30 HU), while the dose values lie in a range from 60 to 500 mGy. Compared to other publications that apply 250-1800 mGy for the same task [C. T. Badea et al., "4D micro-CT of the mouse heart," Mol. Imaging 4(2), 110-116 (2005); M. Drangova et al., "Fast retrospectively gated quantitative four-dimensional (4D) cardiac micro computed tomography imaging of free-breathing mice," Invest. Radiol. 42(2), 85-94 (2007); S. H. Bartling et al., "Retrospective motion gating in small animal CT of mice and rats," Invest. Radiol. 42(10), 704-714 (2007)], the authors' LDPC approach therefore achieves a more than tenfold dose usage improvement. The LDPC reconstruction method improves phase-correlated imaging from highly undersampled data. Artifacts caused by sparse angular sampling are removed and the image noise is decreased, while spatial and temporal resolution are preserved. Thus, the administered dose per animal can be decreased allowing for long-term studies with reduced metabolic inference.
Unlocking the Potential of Public Libraries in Supporting Distance Learning

ERIC Educational Resources Information Center

Nabushawo, Harriet Mutambo; Aguti, Jessica Norah; Winterbottom, Mark

2016-01-01

This paper examines the place of public libraries in supporting distance learners in Makerere University, exploring the factors which affect utilisation of their services. The study adopted a survey design with 300 B.Ed. students, collecting data through focus group discussions, structured questionnaires and individual interviews.
Prosodic Awareness and Children's Multisyllabic Word Reading

ERIC Educational Resources Information Center

Holliman, Andrew J.; Mundy, Ian R.; Wade-Woolley, Lesly; Wood, Clare; Bird, Chelsea

2017-01-01

Prosodic awareness (the rhythmic patterning of speech) accounts for unique variance in reading development. However, studies have thus far focused on early readers and utilised literacy measures which fail to distinguish between monosyllabic and multisyllabic words. The current study investigated the factors that are specifically associated with…
Investigating Factors Affecting the Uptake of Automated Assessment Technology

ERIC Educational Resources Information Center

Dreher, Carl; Reiners, Torsten; Dreher, Heinz

2011-01-01

Automated assessment is an emerging innovation in educational praxis, however its pedagogical potential is not fully utilised in Australia, particularly regarding automated essay grading. The rationale for this research is that the usage of automated assessment currently lags behind the capacity that the technology provides, thus restricting the…
Educational Impact on the Relationship of Environmental Knowledge and Attitudes

ERIC Educational Resources Information Center

Liefländer, A. K.; Bogner, F. X.

2018-01-01

This study examines the relationships between the environmental attitudes and environmental knowledge of school children within the framework of an environmental intervention. We employed questions from the 2-MEV model to monitor students' environmental attitudes in terms of the model factors Preservation and Utilisation while concurrently…
Californian Science Students' Perceptions of Their Classroom Learning Environments

ERIC Educational Resources Information Center

den Brok, Perry; Fisher, Darrell; Rickards, Tony; Bull, Eric

2006-01-01

This study utilised the "What Is Happening In this Class" (WIHIC) questionnaire to examine factors that influence Californian students' perceptions of their learning environment. Data were collected from 665 USA middle school science students in 11 Californian schools. Several background variables, such as gender, socioeconomic status,…
Utilisation of Evidence-Based Practices by ASD Early Intervention Service Providers

ERIC Educational Resources Information Center

Paynter, Jessica M.; Ferguson, Sarah; Fordyce, Kathryn; Joosten, Annette; Paku, Sofia; Stephens, Miranda; Trembath, David; Keen, Deb

2017-01-01

A number of autism intervention practices have been demonstrated to be effective. However, the use of unsupported practices persists in community early intervention settings. Recent research has suggested that personal, professional and workplace factors may influence intervention choices. The aim of this research was to investigate knowledge and…
Psychological Determinants of University Students' Academic Performance: An Empirical Study

ERIC Educational Resources Information Center

Gebka, Bartosz

2014-01-01

This study utilises an integrated conceptual model of academic performance which captures a series of psychological factors: cognitive style; self-theories such as self-esteem and self-efficacy; achievement goals such as mastery, performance, performance avoidance and work avoidance; study-processing strategies such as deep and surface learning;…
Biosensors with Built-In Biomolecular Logic Gates for Practical Applications

PubMed Central

Lai, Yu-Hsuan; Sun, Sin-Cih; Chuang, Min-Chieh

2014-01-01

Molecular logic gates, designs constructed with biological and chemical molecules, have emerged as an alternative computing approach to silicon-based logic operations. These molecular computers are capable of receiving and integrating multiple stimuli of biochemical significance to generate a definitive output, opening a new research avenue to advanced diagnostics and therapeutics which demand handling of complex factors and precise control. In molecularly gated devices, Boolean logic computations can be activated by specific inputs and accurately processed via bio-recognition, bio-catalysis, and selective chemical reactions. In this review, we survey recent advances of the molecular logic approaches to practical applications of biosensors, including designs constructed with proteins, enzymes, nucleic acids, nanomaterials, and organic compounds, as well as the research avenues for future development of digitally operating “sense and act” schemes that logically process biochemical signals through networked circuits to implement intelligent control systems. PMID:25587423
Stretchable carbon nanotube charge-trap floating-gate memory and logic devices for wearable electronics.

PubMed

Son, Donghee; Koo, Ja Hoon; Song, Jun-Kyul; Kim, Jaemin; Lee, Mincheol; Shim, Hyung Joon; Park, Minjoon; Lee, Minbaek; Kim, Ji Hoon; Kim, Dae-Hyeong

2015-05-26

Electronics for wearable applications require soft, flexible, and stretchable materials and designs to overcome the mechanical mismatch between the human body and devices. A key requirement for such wearable electronics is reliable operation with high performance and robustness during various deformations induced by motions. Here, we present materials and device design strategies for the core elements of wearable electronics, such as transistors, charge-trap floating-gate memory units, and various logic gates, with stretchable form factors. The use of semiconducting carbon nanotube networks designed for integration with charge traps and ultrathin dielectric layers meets the performance requirements as well as reliability, proven by detailed material and electrical characterizations using statistics. Serpentine interconnections and neutral mechanical plane layouts further enhance the deformability required for skin-based systems. Repetitive stretching tests and studies in mechanics corroborate the validity of the current approaches.
Effect of high-pressure H{sub 2}O treatment on elimination of interfacial GeO{sub X} layer between ZrO{sub 2} and Ge stack

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Chen-Shuo; Liu, Po-Tsun

2011-08-22

This investigation demonstrates the effect of high-pressure H{sub 2}O treatment on the elimination of the interfacial germanium suboxide (GeO{sub X}) layer between ZrO{sub 2} and Ge. The formation of GeO{sub X} interlayer increases the gate-leakage current and worsen the controllability of the gate during deposition or thermal cycles. X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy reveal that high-pressure H{sub 2}O treatment eliminates the interfacial GeO{sub X} layer. The physical mechanism involves the oxidation of non-oxidized Zr with H{sub 2}O and the reduction of GeO{sub X} by H{sub 2}. Treatment with H{sub 2}O reduces the gate-leakage current of a ZrO{submore » 2}/Ge capacitor by a factor of 1000.« less
Electrically controlled wire-channel GaN/AlGaN transistor for terahertz plasma applications

NASA Astrophysics Data System (ADS)

Cywiński, G.; Yahniuk, I.; Kruszewski, P.; Grabowski, M.; Nowakowski-Szkudlarek, K.; Prystawko, P.; Sai, P.; Knap, W.; Simin, G. S.; Rumyantsev, S. L.

2018-03-01

We report on a design of fin-shaped channel GaN/AlGaN field-effect transistors developed for studying resonant terahertz plasma oscillations. Unlike common two dimensional FinFET transistor design, the gates were deposited only to the sides of the two dimensional electron gas channel, i.e., metal layers were not deposited on the top of the AlGaN. This side gate configuration allowed us to electrically control the conductivity of the channel by changing its width while keeping the carrier density and mobility virtually unchanged. Computer simulations and analytical model describe well the general shape of the characteristics. The side gate control of the channel width of these transistors allowed us to eliminate the so-called oblique plasma wave modes and paves the way towards future terahertz detectors and emitters using high quality factor plasma wave resonances.

Designable DNA-binding domains enable construction of logic circuits in mammalian cells.

PubMed

Gaber, Rok; Lebar, Tina; Majerle, Andreja; Šter, Branko; Dobnikar, Andrej; Benčina, Mojca; Jerala, Roman

2014-03-01

Electronic computer circuits consisting of a large number of connected logic gates of the same type, such as NOR, can be easily fabricated and can implement any logic function. In contrast, designed genetic circuits must employ orthogonal information mediators owing to free diffusion within the cell. Combinatorial diversity and orthogonality can be provided by designable DNA- binding domains. Here, we employed the transcription activator-like repressors to optimize the construction of orthogonal functionally complete NOR gates to construct logic circuits. We used transient transfection to implement all 16 two-input logic functions from combinations of the same type of NOR gates within mammalian cells. Additionally, we present a genetic logic circuit where one input is used to select between an AND and OR function to process the data input using the same circuit. This demonstrates the potential of designable modular transcription factors for the construction of complex biological information-processing devices.
Architecture and applications of a high resolution gated SPAD image sensor

PubMed Central

Burri, Samuel; Maruyama, Yuki; Michalet, Xavier; Regazzoni, Francesco; Bruschini, Claudio; Charbon, Edoardo

2014-01-01

We present the architecture and three applications of the largest resolution image sensor based on single-photon avalanche diodes (SPADs) published to date. The sensor, fabricated in a high-voltage CMOS process, has a resolution of 512 × 128 pixels and a pitch of 24 μm. The fill-factor of 5% can be increased to 30% with the use of microlenses. For precise control of the exposure and for time-resolved imaging, we use fast global gating signals to define exposure windows as small as 4 ns. The uniformity of the gate edges location is ∼140 ps (FWHM) over the whole array, while in-pixel digital counting enables frame rates as high as 156 kfps. Currently, our camera is used as a highly sensitive sensor with high temporal resolution, for applications ranging from fluorescence lifetime measurements to fluorescence correlation spectroscopy and generation of true random numbers. PMID:25090572
Crystal Structure of a Fibroblast Growth Factor Homologous Factor (FHF) Defines a Conserved Surface on FHFs for Binding and Modulation of Voltage-gated Sodium Channels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goetz, R.; Dover, K; Laezza, F

2009-01-01

Voltage-gated sodium channels (Nav) produce sodium currents that underlie the initiation and propagation of action potentials in nerve and muscle cells. Fibroblast growth factor homologous factors (FHFs) bind to the intracellular C-terminal region of the Nav alpha subunit to modulate fast inactivation of the channel. In this study we solved the crystal structure of a 149-residue-long fragment of human FHF2A which unveils the structural features of the homology core domain of all 10 human FHF isoforms. Through analysis of crystal packing contacts and site-directed mutagenesis experiments we identified a conserved surface on the FHF core domain that mediates channel bindingmore » in vitro and in vivo. Mutations at this channel binding surface impaired the ability of FHFs to co-localize with Navs at the axon initial segment of hippocampal neurons. The mutations also disabled FHF modulation of voltage-dependent fast inactivation of sodium channels in neuronal cells. Based on our data, we propose that FHFs constitute auxiliary subunits for Navs.« less
Familial transmission of risk factors in the first-degree relatives of schizophrenic people.

PubMed

Waldo, M C; Adler, L E; Leonard, S; Olincy, A; Ross, R G; Harris, J G; Freedman, R

2000-02-01

Schizophrenia is a complex illness with multiple pathophysiologic factors that contribute to its psychopathology. One strategy to identify these factors is to observe them in isolation from each other, by characterizing their expression in the relatives of schizophrenic probands. By Mendel's second law, each genetic factor should be independently distributed in a sibship, so that each can be observed by itself, uncomplicated by the general problems of the illness. Such independently distributed phenotypes are obviously useful for genetic analyses; however, they can also be considered together, to model how various brain dysfunctions may combine to produce psychoses. In addition to a sensory gating deficit linked to the alpha 7-nicotinic acetylcholine receptor locus, schizophrenics and their families have a number of other deficits, including decreased hippocampal volume on magnetic resonance images and increased plasma levels of the dopamine metabolite homovanillic acid. Although such research is far from complete, a heuristic model combining a sensory gating deficit, decreased hippocampal neuron capacity, and increased dopaminergic neurotransmission is consonant with current understanding of the neuropsychology of schizophrenia.
Crystal Structure of the Ternary Complex of a NaV C-Terminal Domain, a Fibroblast Growth Factor Homologous Factor, and Calmodulin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Chaojian; Chung, Ben C.; Yan, Haidun

2012-11-13

Voltage-gated Na{sup +} (Na{sub V}) channels initiate neuronal action potentials. Na{sub V} channels are composed of a transmembrane domain responsible for voltage-dependent Na{sup +} conduction and a cytosolic C-terminal domain (CTD) that regulates channel function through interactions with many auxiliary proteins, including fibroblast growth factor homologous factors (FHFs) and calmodulin (CaM). Most ion channel structural studies have focused on mechanisms of permeation and voltage-dependent gating but less is known about how intracellular domains modulate channel function. Here we report the crystal structure of the ternary complex of a human NaV CTD, an FHF, and Ca{sup 2+}-free CaM at 2.2 {angstrom}.more » Combined with functional experiments based on structural insights, we present a platform for understanding the roles of these auxiliary proteins in NaV channel regulation and the molecular basis of mutations that lead to neuronal and cardiac diseases. Furthermore, we identify a critical interaction that contributes to the specificity of individual NaV CTD isoforms for distinctive FHFs.« less
Electrical Spin Driving by g -Matrix Modulation in Spin-Orbit Qubits

NASA Astrophysics Data System (ADS)

Crippa, Alessandro; Maurand, Romain; Bourdet, Léo; Kotekar-Patil, Dharmraj; Amisse, Anthony; Jehl, Xavier; Sanquer, Marc; Laviéville, Romain; Bohuslavskyi, Heorhii; Hutin, Louis; Barraud, Sylvain; Vinet, Maud; Niquet, Yann-Michel; De Franceschi, Silvano

2018-03-01

In a semiconductor spin qubit with sizable spin-orbit coupling, coherent spin rotations can be driven by a resonant gate-voltage modulation. Recently, we have exploited this opportunity in the experimental demonstration of a hole spin qubit in a silicon device. Here we investigate the underlying physical mechanisms by measuring the full angular dependence of the Rabi frequency, as well as the gate-voltage dependence and anisotropy of the hole g factor. We show that a g -matrix formalism can simultaneously capture and discriminate the contributions of two mechanisms so far independently discussed in the literature: one associated with the modulation of the g factor, and measurable by Zeeman energy spectroscopy, the other not. Our approach has a general validity and can be applied to the analysis of other types of spin-orbit qubits.
Gender and the utilisation of health services in the Ashanti Region, Ghana.

PubMed

Buor, Daniel

2004-09-01

The survey seeks to structure a model for gender-based health services utilisation for the Ashanti Region of Ghana, and in addition, recommend intervention measures to ensure gender equity in the utilisation of health services. A sample size of 650 covered over 3108 houses, and the main research instruments were the questionnaire and formal interview. A multiple regression model is used for the analysis of the relationship between the complex independent variables and utilisation by gender. Results show that although females have a greater need for health services than males, they do not utilise health services as much. Secondly, whereas quality of service, health status, service cost and education have greater effect on male utilisation than females, distance and income have higher impact on female utilisation. It is recommended that, to ensure equity in health care utilisation, females be empowered through increased access to formal education and sustainable income opportunities. The introduction of a national health insurance scheme is also recommended to ensure adequate access by both sexes.
Progress towards Sustainable Utilisation and Management of Food Wastes in the Global Economy.

PubMed

Ghosh, Purabi R; Fawcett, Derek; Sharma, Shashi B; Poinern, Gerrard Eddy Jai

2016-01-01

In recent years, the problem of food waste has attracted considerable interest from food producers, processors, retailers, and consumers alike. Food waste is considered not only a sustainability problem related to food security, but also an economic problem since it directly impacts the profitability of the whole food supply chain. In developed countries, consumers are one of the main contributors to food waste and ultimately pay for all wastes produced throughout the food supply chain. To secure food and reduce food waste, it is essential to have a comprehensive understanding of the various sources of food wastes throughout the food supply chain. The present review examines various reports currently in the literature and quantifies waste levels and examines the trends in wastage for various food sectors such as fruit and vegetable, fisheries, meat and poultry, grain, milk, and dairy. Factors contributing to food waste, effective cost/benefit food waste utilisation methods, sustainability and environment considerations, and public acceptance are identified as hurdles in preventing large-scale food waste processing. Thus, we highlight the need for further research to identify and report food waste so that government regulators and food supply chain stakeholders can actively develop effective waste utilisation practices.
Progress towards Sustainable Utilisation and Management of Food Wastes in the Global Economy

PubMed Central

Ghosh, Purabi R.; Fawcett, Derek; Sharma, Shashi B.

2016-01-01

In recent years, the problem of food waste has attracted considerable interest from food producers, processors, retailers, and consumers alike. Food waste is considered not only a sustainability problem related to food security, but also an economic problem since it directly impacts the profitability of the whole food supply chain. In developed countries, consumers are one of the main contributors to food waste and ultimately pay for all wastes produced throughout the food supply chain. To secure food and reduce food waste, it is essential to have a comprehensive understanding of the various sources of food wastes throughout the food supply chain. The present review examines various reports currently in the literature and quantifies waste levels and examines the trends in wastage for various food sectors such as fruit and vegetable, fisheries, meat and poultry, grain, milk, and dairy. Factors contributing to food waste, effective cost/benefit food waste utilisation methods, sustainability and environment considerations, and public acceptance are identified as hurdles in preventing large-scale food waste processing. Thus, we highlight the need for further research to identify and report food waste so that government regulators and food supply chain stakeholders can actively develop effective waste utilisation practices. PMID:27847805
Noise And Charge Transport In Carbon Nanotube Devices

NASA Astrophysics Data System (ADS)

Reza, Shahed; Huynh, Quyen T.; Bosman, Gijs; Sippel, Jennifer; Rinzler, Andrew G.

2005-11-01

The charge transport and noise properties of three terminal, gated devices containing multiple, single wall, metallic and semiconductor carbon nanotubes have been measured as a function of gate and drain bias at 300K. Using pulsed bias the metallic tubes could be burned sequentially enabling the separation of measured conductance and low frequency excess noise into metallic and semiconductor contributions. The relative low frequency excess noise of the metallic tubes was about a factor 100 lower than that of the semiconductor tubes, whereas the conductance of the metallic tubes was significantly higher (10 to 50 times) than that of the semiconductor tubes.
Ion-implanted WN 0.25{mu}m gate MESFET fabricated using I-line photolithography for application to MMIC and digital IC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oh, E.O.; Yang, J.W.; Park, C.S.

1995-12-31

Straightforward WN 0.25{mu}m gate MESFET process based on direct ion-implantation and i-line photolithography with double exposure process has produced high performance MESFETs. The maximum transconductance of 600mS/mm and the k-factor of 450ms/Vmm were obtained. As high as 65GHz of cut-off frequency has been realized without any deembedding of parasitic effects. The MESFET shows the minimum noise figure of 0.87 dB and the associated gain of 9.97dB at 12GHz.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Fattori, G; Klimpki, G; Safai, S

Purpose: We aim to compare the performance of discrete spot- or continuous line scanning combined with rescanning in mitigating residual organ motion during gated proton therapy treatments. Methods: The Quasar respiratory phantom was used to move a 2D scintillation detector on a linear trajectory with sinusoidal motion pattern (sin{sup 4}), 20 mm peak-to-peak amplitude and 5 sec period. Its motion was monitored using a customized solution based on optical tracking technology. We compared spot and line scanning plans for a monoenergetic 150 MeV circular field, 50.4 mm radius at isocenter. Transverse dose distributions at 13 cm depth in PMMA (15.47more » mm water equivalent) were measured to compare three options for motion mitigation: rescanning (10× factor), gating and their combination. The gating window was centered in the trajectory plateau to simulate end-exhale gated treatment in presence of 2 mm and 4 mm residual motion, parallel or perpendicular to the primary scanning direction. Results: When the target moves perpendicular to the primary scanning direction, large dose deviations are measured (γ3%/3mm=47%) without mitigation techniques. Beam gating combined with rescanning restores target coverage (γ3%/3mm=91%). For parallel target motion, observed dose distortions in the non-compensated irradiation are smaller (γ3%/3mm=77%). Beam gating alone recovers the 100% gamma pass-rate at 3%/3mm. Continuous line scanning reduces delivery time by up to 60% with respect to discrete spot scanning in presence of motion mitigation, and improves homogeneity when rescanning is applied (up to 20%, perpendicular motion, 4 mm residual motion). Conclusion: The direction of motion has a large impact on the target dose coverage. Nevertheless, even in the worst case scenario, gating combined with rescanning could mitigate the impact of motion on dose deposition. Moreover, continuous line rescanning improves the robustness against residual motion in the gating window. This study has received funding from the European Community’s Seventh Framework Programme (FP7/2007–2013) under grant agreement n.290605 (PSI-FELLOW/COFUND) and ‘Giuliana and Giorgio Stefanini Foundation’.« less
Fifth-year dental students' visions of leadership-A qualitative study.

PubMed

Taipale, H; Tuononen, T A; Suominen, A L

2018-04-22

Leadership skills are important in dentists' work. Leadership education already in undergraduate curriculum is noteworthy. The aim of this qualitative study was to describe dental students' visions of leadership: how they imagined they end up in leadership position, factors supporting either staying in or leaving the position and their future views. The data were gathered after participants, fifth-year dental students, attended a "Dentist as a Leader" study module. A method of empathy-based stories was utilised. Based on contrasting frame stories, students were divided into two groups and wrote essays about an imagined situation in which they either enjoyed their leadership position ("Stayers") or considered leaving it ("Leavers"). The data were analysed using the content analysis method. The reasons for ending up in a leadership position were similar in the two groups: accidentally drifting into or intentionally heading for it. Factors supporting staying or leaving the leadership position were more diverse and were divided into personal and working community levels. These factors were common and group-specific. Clinical work, personal life and the ability to improve the organisations were common factors. Good working community was a "Stayer"-specific factor. "Leaver"-specific factors included loneliness, stress and lack of public sector resources. Future career plans were similar in both groups emphasising clinical work. After having attended leadership training, dental students were able to describe their future careers and list factors supporting either staying or leaving an imagined leadership position. These factors can be utilised by organisations to develop better working environments for future dentist leaders. By recognising the factors, students themselves are able to plan their future career choices and prepare to become leaders. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Resurgent current of voltage-gated Na+ channels

PubMed Central

Lewis, Amanda H; Raman, Indira M

2014-01-01

Resurgent Na+ current results from a distinctive form of Na+ channel gating, originally identified in cerebellar Purkinje neurons. In these neurons, the tetrodotoxin-sensitive voltage-gated Na+ channels responsible for action potential firing have specialized mechanisms that reduce the likelihood that they accumulate in fast inactivated states, thereby shortening refractory periods and permitting rapid, repetitive, and/or burst firing. Under voltage clamp, step depolarizations evoke transient Na+ currents that rapidly activate and quickly decay, and step repolarizations elicit slower channel reopening, or a ‘resurgent’ current. The generation of resurgent current depends on a factor in the Na+ channel complex, probably a subunit such as NaVβ4 (Scn4b), which blocks open Na+ channels at positive voltages, competing with the fast inactivation gate, and unblocks at negative voltages, permitting recovery from an open channel block along with a flow of current. Following its initial discovery, resurgent Na+ current has been found in nearly 20 types of neurons. Emerging research suggests that resurgent current is preferentially increased in a variety of clinical conditions associated with altered cellular excitability. Here we review the biophysical, molecular and structural mechanisms of resurgent current and their relation to the normal functions of excitable cells as well as pathophysiology. PMID:25172941
Scaling of Device Variability and Subthreshold Swing in Ballistic Carbon Nanotube Transistors

NASA Astrophysics Data System (ADS)

Cao, Qing; Tersoff, Jerry; Han, Shu-Jen; Penumatcha, Ashish V.

2015-08-01

In field-effect transistors, the inherent randomness of dopants and other charges is a major cause of device-to-device variability. For a quasi-one-dimensional device such as carbon nanotube transistors, even a single charge can drastically change the performance, making this a critical issue for their adoption as a practical technology. Here we calculate the effect of the random charges at the gate-oxide surface in ballistic carbon nanotube transistors, finding good agreement with the variability statistics in recent experiments. A combination of experimental and simulation results further reveals that these random charges are also a major factor limiting the subthreshold swing for nanotube transistors fabricated on thin gate dielectrics. We then establish that the scaling of the nanotube device uniformity with the gate dielectric, fixed-charge density, and device dimension is qualitatively different from conventional silicon transistors, reflecting the very different device physics of a ballistic transistor with a quasi-one-dimensional channel. The combination of gate-oxide scaling and improved control of fixed-charge density should provide the uniformity needed for large-scale integration of such novel one-dimensional transistors even at extremely scaled device dimensions.
Ambipolar behavior and thermoelectric properties of WS2 nanotubes

NASA Astrophysics Data System (ADS)

Yomogida, Yohei; Kawai, Hideki; Sugahara, Mitsunari; Okada, Ryotaro; Yanagi, Kazuhiro

WS2 nanotubes are rolled multi-walled nanotubes made by a layered material, tungsten disulfides Since the discovery by Tenne et al in 1992, various physical properties have been revealed. Theoretical studies have suggested their distinct electronic properties from those of two dimensional sheet, such as one-dimensional electronic strucutures with sharp van Hove singularities and chiralitiy depended electronic structures. Their fibril structures enable us to make their random network films, however, the films are not conducting, and thus have not been used for electronic applications. Here we demonstrate that carrier injections on the WS2 networks by an electrolyte gating approach could make the networks as a semiconducting channel. We clarified the Raman characteristics of WS2 nanotubes networks under electrolyte gating, and confirmed capability of electron and hole injections. We revealed ambipolar behaviors of the WS2 nanotube networks in field effect transistor setups with electrolyte gating. In additio, we demosntrate N-type and P-type control of thermoelectric properties of WS2 nanotubes by electrolyte gating.The power factor of the WS2 nanotubes almost approached to that of the single crystalline WS2 flakes, suggesting good potential for thermoelectric applications..
GateKeeper: a new hardware architecture for accelerating pre-alignment in DNA short read mapping.

PubMed

Alser, Mohammed; Hassan, Hasan; Xin, Hongyi; Ergin, Oguz; Mutlu, Onur; Alkan, Can

2017-11-01

High throughput DNA sequencing (HTS) technologies generate an excessive number of small DNA segments -called short reads- that cause significant computational burden. To analyze the entire genome, each of the billions of short reads must be mapped to a reference genome based on the similarity between a read and 'candidate' locations in that reference genome. The similarity measurement, called alignment, formulated as an approximate string matching problem, is the computational bottleneck because: (i) it is implemented using quadratic-time dynamic programming algorithms and (ii) the majority of candidate locations in the reference genome do not align with a given read due to high dissimilarity. Calculating the alignment of such incorrect candidate locations consumes an overwhelming majority of a modern read mapper's execution time. Therefore, it is crucial to develop a fast and effective filter that can detect incorrect candidate locations and eliminate them before invoking computationally costly alignment algorithms. We propose GateKeeper, a new hardware accelerator that functions as a pre-alignment step that quickly filters out most incorrect candidate locations. GateKeeper is the first design to accelerate pre-alignment using Field-Programmable Gate Arrays (FPGAs), which can perform pre-alignment much faster than software. When implemented on a single FPGA chip, GateKeeper maintains high accuracy (on average >96%) while providing, on average, 90-fold and 130-fold speedup over the state-of-the-art software pre-alignment techniques, Adjacency Filter and Shifted Hamming Distance (SHD), respectively. The addition of GateKeeper as a pre-alignment step can reduce the verification time of the mrFAST mapper by a factor of 10. https://github.com/BilkentCompGen/GateKeeper. mohammedalser@bilkent.edu.tr or onur.mutlu@inf.ethz.ch or calkan@cs.bilkent.edu.tr. Supplementary data are available at Bioinformatics online. © The Author (2017). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com
Bone preserving techniques for explanting the well-fixed cemented acetabular component.

PubMed

Stevens, Jarrad; Macpherson, Gavin; Howie, Colin

2018-06-01

Removal of a well-fixed, cemented acetabular component at the time of revision hip surgery can be complex. It is essential to remove the implant and cement mantle in a timely fashion while preserving bone stock and osseous integrity. The biomechanical properties of polymethylmethacrylate cement and polyethylene can be utilised to aid with the removal of well cemented implants which are often harder than the surrounding bone. While removal of loose components may be relatively straightforward, the challenge for the revision arthroplasty surgeon often involves the removal of well-fixed implants. Here, we present three established techniques for the removal of a well-fixed cemented acetabular component and one novel modification we have described before. We collate and review four techniques for removing well-fixed cemented acetabular implants that utilise the different biomechanical properties of bone cement and polyethylene. These techniques are illustrated with a photographic series utilising saw bones. A step-by-step approach to our new technique is shown in photographs, both in the clinical setting and with a "Sawbone". This is accompanied by a clinical video that details the surgical technique in its entirety. These techniques utilise different biomechanical principles to extract the acetabular component. Each technique has advantages and disadvantages. Our new technique is a simplification of a previously published extraction manoeuvre that utilises tensile force between cement and the implant to remove the polyethylene cup. This is a safe and reproducible technique in patients with a well-fixed cemented acetabular implant. Understanding the biomechanical properties of polymethylmethacrylate bone cement and polyethylene can aid in the safe removal of a well-fixed cemented acetabular component in revision hip surgery. The optimal technique for removal of a cemented acetabular component varies depending on a number of patient and implant factors. This summary of the available techniques will be of interest to revision arthroplasty surgeons.
Self-reported illnesses and service utilisation among migrants working in small-to medium sized enterprises in Guangdong, China.

PubMed

Zou, G; Zeng, Z; Chen, W; Ling, L

2015-07-01

As one of the most vulnerable populations in China, many migrants work in the small-to-medium-sized enterprises (SMEs). This study aims to describe the self-reported illnesses and service utilization of the migrants working in the SMEs in Pearl River Delta Areas (PRDA) of Guangdong province, China. Cross-sectional survey. We interviewed 856 migrants working in the SMEs of different manufacturing industries in 2012. Descriptive analysis was employed to report self-reported illnesses and service utilisation among migrants in the last two weeks and in the last year. Statistical tests such as χ2 test were used to explore factors influencing their service utilisation. In the last two weeks, 91(11%) of the respondents reported having any illness. The most reported illness was respiratory problem (69%), while 9.9%, 7.7% and 13% reported having digestive, skin and other problems respectively. The most important symptom was cough (39%). Thirty-seven percent of the respondents who reported any illness had visited health facilities. The lower income group were more likely to visit health facilities than the higher income group (P = 0.006). The most reported reason for not visiting health facilities was 'feeling not serious' (65%). In the last year, 13% reported having respiratory problems and 7.8% reported accidental injuries. Less than 3% received hospitalization care. The proportion of those without hospitalization to those who should have been hospitalized was 31%. Underuse of the health service among migrants working in the SMEs could be associated with the 'healthy migrant' effect. However, when assessed among the ill migrants in the SMEs, the utilisation rate was still low mainly due to their poor health awareness. Improving their risk perception and integration of occupational and general health service is crucial to improve the health conditions and utilisation of service among migrants in the SMES. Copyright © 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
Pharmacotherapy Evaluation and Utilization in Coronary Artery Bypass Grafting Patients in Kosovo during the Period 2016-2017

PubMed Central

Daci, Armond; Bozalija, Adnan; Cavolli, Raif; Alaj, Rame; Beretta, Giangiacomo; Krasniqi, Shaip

2018-01-01

BACKGROUND: Coronary Artery Bypass Grafting (CABG) is realised in patients with critical or advanced disease of coronary arteries. There are different pharmacotherapeutic approaches which are used as management, treatment and preventive therapy in cardiovascular disease or related comorbidities. Performing a successful surgery, pharmacotherapy, and increase of bypass patency rate remains a serious challenge. AIM: This study aims to analyse the patient characteristics undergoing CABG and evaluation of their drug utilisation rate and daily dosages in the perioperative period. MATERIAL AND METHODS: Data were collected from 102 patients in the period 2016-2017 and detailed therapeutic prescription and dosages, patient characteristics were analysed before the operation, after the operation and visit after operation in the Clinic of Cardiac surgery-University Clinical Center of Kosovo. RESULTS: Our findings had shown that patients provided to have normal biochemical parameters in the clinic before the operation, and were related to cardiovascular diseases and comorbidities and risk factors with mainly elective intervention. The, however, higher utilisation of cardiovascular drugs such as beta blockers, diuretics, anticoagulants, statins and lower calcium blockers, ACEi, ARBs, hydrochlorothiazide, amiodarone were founded. ARBs, beta blockers, statins, nitrates and nadroparin utilisation decreased after operation and visit after the operation, whereas amiodarone only in the visit after the operation. Diuretics are increased after the operation which decreases in the visit after the operation. Regarding the daily dosage, only metoprolol was increased in the visit after operation (P < 0.001) and visit after operation (P < 0.05) whereas losartan and furosemide were increased (P < 0.01) and (P < 0.05) respectively. CONCLUSION: The study showed that beta blockers, statins, aspirin, nitrates (before the operation), furosemide and spironolactone are the most utilised drugs. However, we found low utilisation rate for ACEi, ARBs, clopidogrel, nadroparin, warfarin, xanthines, amiodarone, calcium blockers. Daily dosages were different compared to before CABG only in metoprolol, losartan, and furosemide. PMID:29610608

Sociodemographic factors are associated with utilisation of statins after ischaemic stroke/TIA.

PubMed

Geary, Lukas; Aronius, Jonas; Wettermark, Björn; Hasselström, Jan; Sjöborg, Bengt; von Euler, Mia

2017-03-01

To analyse if there are sociodemographic differences in the utilisation of statins 9-12 months after ischaemic stroke or transitory ischaemic attack. Anonymised linkage of registry data on all patients >18 years discharged from the hospitals in Stockholm, Sweden 2006-2010 with diagnosis of ischaemic stroke (ICD-10: I63.0-9) or TIA (ICD-10: G45.9) was performed. Data on hospitalisations and diagnoses were collected from the Stockholm County Council administrative databases on healthcare consumption. Dispensed prescriptions with statins and, for comparative purposes, antihypertensive agents 9-12 months after discharge were acquired from the National Swedish Prescribed Drug Register. Data about socioeconomic factors were obtained from Statistics Sweden. The dispensing of statins and antihypertensive agents, relative to sociodemographic variables were analysed. Using logistic regression odds ratios, crude, and adjusted with education, income, origin of birth, age, and sex as predictors where calculated. Of 24 312 patients with ischaemic stroke/TIA, 19 335 were alive 12 months after discharge. Statins were dispensed to 44% of all patients in the cohort, more frequently to men of all age groups, to patients with higher education, and to those with higher income. Antihypertensive agents were dispensed to 68% of all patients and there were no differences related to sex and income whilst patients with lower education were dispensed with antihypertensives more frequently. We find a low utilisation of statins one year after ischaemic stroke/TIA. Patients with low education, low income, and female sex were dispensed fewer prescriptions of statins indicating a need for improvement. © 2017 John Wiley & Sons Ltd.
An analysis of partial efficiencies of energy utilisation of different macronutrients by barramundi (Lates calcarifer) shows that starch restricts protein utilisation in carnivorous fish.

PubMed

Glencross, Brett D; Blyth, David; Bourne, Nicholas; Cheers, Susan; Irvin, Simon; Wade, Nicholas M

2017-02-01

This study examined the effect of including different dietary proportions of starch, protein and lipid, in diets balanced for digestible energy, on the utilisation efficiencies of dietary energy by barramundi (Lates calcarifer). Each diet was fed at one of three ration levels (satiety, 80 % of initial satiety and 60 % of initial satiety) for a 42-d period. Fish performance measures (weight gain, feed intake and feed conversion ratio) were all affected by dietary energy source. The efficiency of energy utilisation was significantly reduced in fish fed the starch diet relative to the other diets, but there were no significant effects between the other macronutrients. This reduction in efficiency of utilisation was derived from a multifactorial change in both protein and lipid utilisation. The rate of protein utilisation deteriorated as the amount of starch included in the diet increased. Lipid utilisation was most dramatically affected by inclusion levels of lipid in the diet, with diets low in lipid producing component lipid utilisation rates well above 1·3, which indicates substantial lipid synthesis from other energy sources. However, the energetic cost of lipid gain was as low as 0·65 kJ per kJ of lipid deposited, indicating that barramundi very efficiently store energy in the form of lipid, particularly from dietary starch energy. This study defines how the utilisation efficiency of dietary digestible energy by barramundi is influenced by the macronutrient source providing that energy, and that the inclusion of starch causes problems with protein utilisation in this species.
Source-drain burnout mechanism of GaAs power MESFETS: Three terminal effects

NASA Astrophysics Data System (ADS)

Takamiya, Saburo; Sonoda, Takuji; Yamanouchi, Masahide; Fujioka, Takashi; Kohno, Masaki

1997-03-01

Theoretical expressions for thermal and electrical feedback effects are derived. These limit the power capability of a power FET and lead a device to catastrophic breakdown (source-drain burnout) when the loop gain of the former reaches unity. Field emission of thermally excited electrons at the Schottky gate plays the key role in thermal feedback, while holes being impact ionized by the drain current play a similar role in the electrical feedback. Thermal feedback is dominant in a high temperature and low drain voltage area. Electrical feedback is dominant in a high drain voltage and low temperature area. In the first area, a high junction temperature is the main factor causing the thermal runaway of the device. In the second area, the electrcal feedback increases the drain current and the temperature and gives a trigger to the thermal feedback so that it reaches unity more easily. Both effects become significant in proportion to transconductance and gate bias resistance, and cause simultaneous runaway of the gate and drain currents. The expressions of the loop gains clearly indicate the safe operating conditions for a power FET. C-band 4 W (1 chip) and 16 W (4 chip) GaAs MESFETs were used as the experimental samples. With these devices the simultaneous runaway of the gate and the drain currents, apparent dependence of the three teminal breakdown voltage on the gate bias resistance in the region dominated by electrical feedback, the rapid increase of the field emitted current at the critical temperature and clear coincidence between the measured and calculated three terminal gate currents both in the thermal feedback dominant region, etc. are demonstrated. The theory explains the experimental results well.
Effects of passive and active movement on vibrotactile detection thresholds of the Pacinian channel and forward masking.

PubMed

Yıldız, Mustafa Z; Toker, İpek; Özkan, Fatma B; Güçlü, Burak

2015-01-01

We investigated the gating effect of passive and active movement on the vibrotactile detection thresholds of the Pacinian (P) psychophysical channel and forward masking. Previous work on gating mostly used electrocutaneous stimulation and did not allow focusing on tactile submodalities. Ten healthy adults participated in our study. Passive movement was achieved by swinging a platform, on which the participant's stimulated hand was attached, manually by a trained operator. The root-mean-square value of the movement speed was kept in a narrow range (slow: 10-20 cm/s, fast: 50-60 cm/s). Active movement was performed by the participant him-/herself using the same apparatus. The tactile stimuli consisted of 250-Hz sinusoidal mechanical vibrations, which were generated by a shaker mounted on the movement platform and applied to the middle fingertip. In the forward-masking experiments, a high-level masking stimulus preceded the test stimulus. Each movement condition was tested separately in a two-interval forced-choice detection task. Both passive and active movement caused a robust gating effect, that is, elevation of thresholds, in the fast speed range. Statistically significant change of thresholds was not found in slow movement conditions. Passive movement yielded higher thresholds than those measured during active movement, but this could not be confirmed statistically. On the other hand, the effect of forward masking was approximately constant as the movement condition varied. These results imply that gating depends on both peripheral and central factors in the P channel. Active movement may have some facilitatory role and produce less gating. Additionally, the results support the hypothesis regarding a critical speed for gating, which may be relevant for daily situations involving vibrations transmitted through grasped objects and for manual exploration.
Coronary CT angiography with single-source and dual-source CT: comparison of image quality and radiation dose between prospective ECG-triggered and retrospective ECG-gated protocols.

PubMed

Sabarudin, Akmal; Sun, Zhonghua; Yusof, Ahmad Khairuddin Md

2013-09-30

This study is conducted to investigate and compare image quality and radiation dose between prospective ECG-triggered and retrospective ECG-gated coronary CT angiography (CCTA) with the use of single-source CT (SSCT) and dual-source CT (DSCT). A total of 209 patients who underwent CCTA with suspected coronary artery disease scanned with SSCT (n=95) and DSCT (n=114) scanners using prospective ECG-triggered and retrospective ECG-gated protocols were recruited from two institutions. The image was assessed by two experienced observers, while quantitative assessment was performed by measuring the image noise, the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR). Effective dose was calculated using the latest published conversion coefficient factor. A total of 2087 out of 2880 coronary artery segments were assessable, with 98.0% classified as of sufficient and 2.0% as of insufficient image quality for clinical diagnosis. There was no significant difference in overall image quality between prospective ECG-triggered and retrospective gated protocols, whether it was performed with DSCT or SSCT scanners. Prospective ECG-triggered protocol was compared in terms of radiation dose calculation between DSCT (6.5 ± 2.9 mSv) and SSCT (6.2 ± 1.0 mSv) scanners and no significant difference was noted (p=0.99). However, the effective dose was significantly lower with DSCT (18.2 ± 8.3 mSv) than with SSCT (28.3 ± 7.0 mSv) in the retrospective gated protocol. Prospective ECG-triggered CCTA reduces radiation dose significantly compared to retrospective ECG-gated CCTA, while maintaining good image quality. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.
Identification of key factors affecting the water pollutant concentration in the sluice-controlled river reaches of the Shaying River in China via statistical analysis methods.

PubMed

Dou, Ming; Zhang, Yan; Zuo, Qiting; Mi, Qingbin

2015-08-01

The construction of sluices creates a strong disturbance in water environmental factors within a river. The change in water pollutant concentrations of sluice-controlled river reaches (SCRRs) is more complex than that of natural river segments. To determine the key factors affecting water pollutant concentration changes in SCRRs, river reaches near the Huaidian Sluice in the Shaying River of China were selected as a case study, and water quality monitoring experiments based on different regulating modes were implemented in 2009 and 2010. To identify the key factors affecting the change rates for the chemical oxygen demand of permanganate (CODMn) and ammonia nitrogen (NH3-N) concentrations in the SCRRs of the Huaidian Sluice, partial correlation analysis, principal component analysis and principal factor analysis were used. The results indicate four factors, i.e., the inflow quantity from upper reaches, opening size of sluice gates, water pollutant concentration from upper reaches, and turbidity before the sluice, which are the common key factors for the CODMn and NH3-N concentration change rates. Moreover, the dissolved oxygen before a sluice is a key factor for the permanganate concentration from CODMn change rate, and the water depth before a sluice is a key factor for the NH3-N concentration change rate. Multiple linear regressions between the water pollutant concentration change rate and key factors were established via multiple linear regression analyses, and the quantitative relationship between the CODMn and NH3-N concentration change rates and key affecting factors was analyzed. Finally, the mechanism of action for the key factors affecting the water pollutant concentration changes was analyzed. The results reveal that the inflow quantity from upper reaches, opening size of sluice gates, permanganate concentration from CODMn from upper reaches and dissolved oxygen before the sluice have a negative influence and the turbidity before the sluice has a positive influence on the permanganate concentration from CODMn change rates and that the opening size of sluice gates, NH3-N concentration from upper reaches, and water depth before the sluice have a negative influence and the inflow quantity from upper reaches and turbidity before the sluice have a positive influence on the NH3-N concentration change rates, which provides a scientific grounding for pollution control and sluice operations in SCRRs.
Efficient simulation of voxelized phantom in GATE with embedded SimSET multiple photon history generator.

PubMed

Lin, Hsin-Hon; Chuang, Keh-Shih; Lin, Yi-Hsing; Ni, Yu-Ching; Wu, Jay; Jan, Meei-Ling

2014-10-21

GEANT4 Application for Tomographic Emission (GATE) is a powerful Monte Carlo simulator that combines the advantages of the general-purpose GEANT4 simulation code and the specific software tool implementations dedicated to emission tomography. However, the detailed physical modelling of GEANT4 is highly computationally demanding, especially when tracking particles through voxelized phantoms. To circumvent the relatively slow simulation of voxelized phantoms in GATE, another efficient Monte Carlo code can be used to simulate photon interactions and transport inside a voxelized phantom. The simulation system for emission tomography (SimSET), a dedicated Monte Carlo code for PET/SPECT systems, is well-known for its efficiency in simulation of voxel-based objects. An efficient Monte Carlo workflow integrating GATE and SimSET for simulating pinhole SPECT has been proposed to improve voxelized phantom simulation. Although the workflow achieves a desirable increase in speed, it sacrifices the ability to simulate decaying radioactive sources such as non-pure positron emitters or multiple emission isotopes with complex decay schemes and lacks the modelling of time-dependent processes due to the inherent limitations of the SimSET photon history generator (PHG). Moreover, a large volume of disk storage is needed to store the huge temporal photon history file produced by SimSET that must be transported to GATE. In this work, we developed a multiple photon emission history generator (MPHG) based on SimSET/PHG to support a majority of the medically important positron emitters. We incorporated the new generator codes inside GATE to improve the simulation efficiency of voxelized phantoms in GATE, while eliminating the need for the temporal photon history file. The validation of this new code based on a MicroPET R4 system was conducted for (124)I and (18)F with mouse-like and rat-like phantoms. Comparison of GATE/MPHG with GATE/GEANT4 indicated there is a slight difference in energy spectra for energy below 50 keV due to the lack of x-ray simulation from (124)I decay in the new code. The spatial resolution, scatter fraction and count rate performance are in good agreement between the two codes. For the case studies of (18)F-NaF ((124)I-IAZG) using MOBY phantom with 1 × 1 × 1 mm(3) voxel sizes, the results show that GATE/MPHG can achieve acceleration factors of approximately 3.1 × (4.5 ×), 6.5 × (10.7 ×) and 9.5 × (31.0 ×) compared with GATE using the regular navigation method, the compressed voxel method and the parameterized tracking technique, respectively. In conclusion, the implementation of MPHG in GATE allows for improved efficiency of voxelized phantom simulations and is suitable for studying clinical and preclinical imaging.
Examining Factors Affecting Beginning Teachers' Transfer of Learning of ICT-Enhanced Learning Activities in Their Teaching Practice

ERIC Educational Resources Information Center

Agyei, Douglas D.; Voogt, Joke

2014-01-01

This study examined 100 beginning teachers' transfer of learning when utilising Information Communication Technology-enhanced activity-based learning activities. The beginning teachers had participated in a professional development program that was characterised by "learning technology by collaborative design" in their final year of…
Exploring Sex Differences in Autistic Traits: A Factor Analytic Study of Adults with Autism

ERIC Educational Resources Information Center

Grove, Rachel; Hoekstra, Rosa A.; Wierda, Marlies; Begeer, Sander

2017-01-01

Research has highlighted potential differences in the phenotypic and clinical presentation of autism spectrum conditions across sex. Furthermore, the measures utilised to evaluate autism spectrum conditions may be biased towards the male autism phenotype. It is important to determine whether these instruments measure the autism phenotype…
Referral for Occupational Therapy after Diagnosis of Developmental Disorder by German Child Psychiatrists

ERIC Educational Resources Information Center

Konrad, Marcel; Drosselmeyer, Julia; Kostev, Karel

2016-01-01

Aims: The aims of this study were to assess how many patients received occupational therapy after diagnosis of developmental disorder (DD) in child psychiatrist practices in Germany and which factors influenced the prescription of occupational therapy. Methods: This study was a retrospective database analysis in Germany utilising the Disease…
Twins with Autism: Utilising Video Feedback to Improve Job-Related Behaviours

ERIC Educational Resources Information Center

Mackey, Megan; Nelson, Gretchen

2015-01-01

Employment for individuals with autism spectrum disorders (ASD) is a significant factor in assuring quality of life in adulthood. The research reported in this article examines the effectiveness of video feedback (VFB) in improving the job-related behaviours of twin adolescents with ASD and learning disabilities. The targeted behaviours included…
Flexible Work Arrangements: Accessibility in a University Environment

ERIC Educational Resources Information Center

Sharafizad, Fleur; Paull, Megan; Omari, Maryam

2011-01-01

Attraction and retention of highly qualified employees has become an area of concern for Australian universities. It has been suggested that flexible work arrangements can be utilised to achieve this goal once the factors affecting their uptake have been identified. This mixed-method study of 495 academic and general staff at an Australian…
Neighborhood deprivation and small-for-gestaional-age term births among non-Hispanic whites and non-Hispanic blacks in the United States

EPA Science Inventory

Residential context has received increased attention as a possible contributing factor to race/ethnic and socio-economic disparities in birth outcomes in the United States. Utilising vital statistics birth record data, this study examined the association between neighbourhood dep...
Factors Affecting the Item Parameter Estimation and Classification Accuracy of the DINA Model

ERIC Educational Resources Information Center

de la Torre, Jimmy; Hong, Yuan; Deng, Weiling

2010-01-01

To better understand the statistical properties of the deterministic inputs, noisy "and" gate cognitive diagnosis (DINA) model, the impact of several factors on the quality of the item parameter estimates and classification accuracy was investigated. Results of the simulation study indicate that the fully Bayes approach is most accurate when the…
Methodology for Analysis, Modeling and Simulation of Airport Gate-waiting Delays

NASA Astrophysics Data System (ADS)

Wang, Jianfeng

This dissertation presents methodologies to estimate gate-waiting delays from historical data, to identify gate-waiting-delay functional causes in major U.S. airports, and to evaluate the impact of gate operation disruptions and mitigation strategies on gate-waiting delay. Airport gates are a resource of congestion in the air transportation system. When an arriving flight cannot pull into its gate, the delay it experiences is called gate-waiting delay. Some possible reasons for gate-waiting delay are: the gate is occupied, gate staff or equipment is unavailable, the weather prevents the use of the gate (e.g. lightning), or the airline has a preferred gate assignment. Gate-waiting delays potentially stay with the aircraft throughout the day (unless they are absorbed), adding costs to passengers and the airlines. As the volume of flights increases, ensuring that airport gates do not become a choke point of the system is critical. The first part of the dissertation presents a methodology for estimating gate-waiting delays based on historical, publicly available sources. Analysis of gate-waiting delays at major U.S. airports in the summer of 2007 identifies the following. (i) Gate-waiting delay is not a significant problem on majority of days; however, the worst delay days (e.g. 4% of the days at LGA) are extreme outliers. (ii) The Atlanta International Airport (ATL), the John F. Kennedy International Airport (JFK), the Dallas/Fort Worth International Airport (DFW) and the Philadelphia International Airport (PHL) experience the highest gate-waiting delays among major U.S. airports. (iii) There is a significant gate-waiting-delay difference between airlines due to a disproportional gate allocation. (iv) Gate-waiting delay is sensitive to time of a day and schedule peaks. According to basic principles of queueing theory, gate-waiting delay can be attributed to over-scheduling, higher-than-scheduled arrival rate, longer-than-scheduled gate-occupancy time, and reduced gate availability. Analysis of the worst days at six major airports in the summer of 2007 indicates that major gate-waiting delays are primarily due to operational disruptions---specifically, extended gate occupancy time, reduced gate availability and higher-than-scheduled arrival rate (usually due to arrival delay). Major gate-waiting delays are not a result of over-scheduling. The second part of this dissertation presents a simulation model to evaluate the impact of gate operational disruptions and gate-waiting-delay mitigation strategies, including building new gates, implementing common gates, using overnight off-gate parking and adopting self-docking gates. Simulation results show the following effects of disruptions: (i) The impact of arrival delay in a time window (e.g. 7 pm to 9 pm) on gate-waiting delay is bounded. (ii) The impact of longer-than-scheduled gate-occupancy times in a time window on gate-waiting delay can be unbounded and gate-waiting delay can increase linearly as the disruption level increases. (iii) Small reductions in gate availability have a small impact on gate-waiting delay due to slack gate capacity, while larger reductions have a non-linear impact as slack gate capacity is used up. Simulation results show the following effects of mitigation strategies: (i) Implementing common gates is an effective mitigation strategy, especially for airports with a flight schedule not dominated by one carrier, such as LGA. (ii) The overnight off-gate rule is effective in mitigating gate-waiting delay for flights stranded overnight following departure cancellations. This is especially true at airports where the gate utilization is at maximum overnight, such as LGA and DFW. The overnight off-gate rule can also be very effective to mitigate gate-waiting delay due to operational disruptions in evenings. (iii) Self-docking gates are effective in mitigating gate-waiting delay due to reduced gate availability.
Evidence of the factors that influence the utilisation of Kangaroo Mother Care by parents with low-birth-weight infants in low- and middle-income countries (LMICs): a scoping review protocol.

PubMed

Mathias, Christina T; Mianda, Solange; Ginindza, Themba G

2018-04-05

The Sustainable Development Goal (SDG) 3 emphasises on reducing neonatal deaths caused by low birth weight (LBW) complications by the implementation and utilisation of Kangaroo Mother Care (KMC) in low- and middle-income countries (LMICs). Despite the empirical evidence of KMC optimising low-birth-weight infants' (LBWIs') survival, its advantages and the LMICs implementing the service, studies have shown that LBW infant deaths occurring in LMICs are largely contributing to global child mortality. The aim of this scoping review is to map out the literature on barriers, challenges and facilitators of KMC utilisation by parents with LBWIs. This scoping review will use Endnote X7 reference management software to manage articles. The review search strategy will use SCIELO and LILACS databases. Other databases will be used via EBSCOHost search engine and these are Academic search complete, CINAHL with full text, Education source, Health source: Nursing/Academic Edition, Medline with full text and Medline. We will also use Google Scholar, JSTOR, Open grey search engines and reference lists. A two-phase search mapping out process will be done. In phase 1, one reviewer will perform the title screening and removal of duplicates. Two reviewers will do a parallel abstract screening according to eligibility criteria. Phase 2 will involve the reading of full articles and exclusion of articles, in accordance with the eligibility criteria. Data extraction from the articles will be done by two reviewers independently and parallel to the data extraction form. The data quality assessment of the eligible studies will be done using the Mixed Method Appraisal Tool (MMAT). The extraction of the synthesised results and thematic content analysis of the studies will be done by NVIVO version 10. We expect to find studies on barriers, challenges and facilitating factors of KMC utilisation by parents with LBWIs in LMICs. The review outcomes will guide future research and practice and inform policy. The findings will be disseminated in print, electronic and conference presentations related to maternal child and neonatal health.
Access and utilisation of primary health care services comparing urban and rural areas of Riyadh Providence, Kingdom of Saudi Arabia.

PubMed

Alfaqeeh, Ghadah; Cook, Erica J; Randhawa, Gurch; Ali, Nasreen

2017-02-02

The Kingdom of Saudi Arabia (KSA) has seen an increase in chronic diseases. International evidence suggests that early intervention is the best approach to reduce the burden of chronic disease. However, the limited research available suggests that health care access remains unequal, with rural populations having the poorest access to and utilisation of primary health care centres and, consequently, the poorest health outcomes. This study aimed to examine the factors influencing the access to and utilisation of primary health care centres in urban and rural areas of Riyadh province of the KSA. A questionnaire survey was carried out to identify the barriers and enablers to accessing PHCS in rural (n = 5) and urban (n = 5) areas of Riyadh province, selected on the classification of the population density of the governorates. An adapted version of the NHS National Survey Programme was administered that included 50 questions over 11 sections that assessed a wide range of factors related to respondent's access and experience of the PHCS. A total of 935 responses were obtained with 52.9% (n = 495) from urban areas and the remaining 47.1% (n = 440) from rural areas of Riyadh province. This study highlights that there are high levels of satisfaction among patients among all PHCS. In relation to differences between urban and rural respondents, the findings indicated that there were significant variations in relation to: education level, monthly income, medical investigations, receiving blood tests on time, extra opening hours, distance, cleanliness and health prevention. Core barriers for rural patients related to the distance to reach PHCS, cleanliness of the PHCS, receiving health prevention and promotion services, which should serve to improve health outcomes. This study highlighted important differences in access to and utilisation of PHCS between urban and rural populations in Riyadh province in the KSA. These findings have implications for policy and planning of PHCCs and reducing inequalities in health care between rural and urban populations and contributing to a reduction in the chronic disease burden in Riyadh province.
Back-gated graphene anode for more efficient thermionic energy converters

DOE PAGES

Yuan, Hongyuan; Riley, Daniel C.; Shen, Zhi-Xun; ...

2016-12-15

Thermionic energy converters (TECs) are a direct heat-to-electricity conversion technology with great potential for high efficiency and scalability. However, space charge barrier in the inter-electrode gap and high anode work function are major obstacles toward realizing high efficiency. Here, we demonstrate for the first time a prototype TEC using a back-gated graphene anode, a barium dispenser cathode, and a controllable inter-electrode gap as small as 17 µm, which simultaneously addresses these two obstacles. This leads to an electronic conversion efficiency of 9.8% at cathode temperature of 1000 °C, the highest reported by far. We first demonstrate that electrostatic gating ofmore » graphene by a 20 nm HfO 2 dielectric layer changes the graphene anode work function by 0.63 eV, as observed from the current-voltage characteristics of the TEC. Next, we show that the efficiency increases by a factor of 30.6 by reducing the gap from 1 mm down to 17 µm, after a mono-layer of Ba is deposited on graphene by the dispenser cathode. Lastlu, we show that electrostatic gating of graphene further reduces the graphene work function from 1.85 to 1.69 eV, leading to an additional 67% enhancement in TEC efficiency. Note that the overall efficiency using the back-gated graphene anode is 6.7 times higher compared with that of a TEC with a tungsten anode and the same inter-electrode gap.« less
Back-gated graphene anode for more efficient thermionic energy converters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, Hongyuan; Riley, Daniel C.; Shen, Zhi-Xun

Thermionic energy converters (TECs) are a direct heat-to-electricity conversion technology with great potential for high efficiency and scalability. However, space charge barrier in the inter-electrode gap and high anode work function are major obstacles toward realizing high efficiency. Here, we demonstrate for the first time a prototype TEC using a back-gated graphene anode, a barium dispenser cathode, and a controllable inter-electrode gap as small as 17 µm, which simultaneously addresses these two obstacles. This leads to an electronic conversion efficiency of 9.8% at cathode temperature of 1000 °C, the highest reported by far. We first demonstrate that electrostatic gating ofmore » graphene by a 20 nm HfO 2 dielectric layer changes the graphene anode work function by 0.63 eV, as observed from the current-voltage characteristics of the TEC. Next, we show that the efficiency increases by a factor of 30.6 by reducing the gap from 1 mm down to 17 µm, after a mono-layer of Ba is deposited on graphene by the dispenser cathode. Lastlu, we show that electrostatic gating of graphene further reduces the graphene work function from 1.85 to 1.69 eV, leading to an additional 67% enhancement in TEC efficiency. Note that the overall efficiency using the back-gated graphene anode is 6.7 times higher compared with that of a TEC with a tungsten anode and the same inter-electrode gap.« less
Trends, determinants and inequities of 4+ ANC utilisation in Bangladesh.

PubMed

Rahman, Aminur; Nisha, Monjura Khatun; Begum, Tahmina; Ahmed, Sayem; Alam, Nurul; Anwar, Iqbal

2017-01-13

The objectives of this study are to document the trend on utilisation of four or more (4 + ) antenatal care (ANC) over the last 22 years period and to explore the determinants and inequity of 4 + ANC utilisation as reported by the last two Bangladesh Demographic and Health surveys (BDHS) (2011 and 2014). The data related to ANC have been extracted from the BDHS data set which is available online as an open source. STATA 13 software was used for organising and analysing the data. The outcome variable considered for this study was utilisation of 4 + ANC. Trends of 4 + ANC were measured in percentage and predictors for 4 + ANC were measured through bivariate and multivariable analysis. The concentration index was estimated for assessing inequity in 4 + ANC utilisation. Utilisation of 4 + ANC has increased by about 26% between the year 1994 and 2014. Higher level of education, residing in urban region and richest wealth quintile were found to be significant predictors. The utilisation of 4 + ANC has decreased with increasing parity and maternal age. The inequity indices showed consistent inequities in 4 + ANC utilisation, and such inequities were increased between 2011 and 2014. In Bangladesh, the utilisation of any ANC rose steadily between 1994 and 2014, but progress in terms of 4 + ANC utilisation was much slower as the expectation was to achieve the national set target (50%: 4 + ANC utilisation) by 2016. Socio-economic inequities were observed in groups that failed to attend a 4 + ANC visit. Policymakers should pay special attention to increase the 4 + ANC coverage where this study can facilitate to identify the target groups whom need to be intervened on priority basis.

Risk factors for oral diseases among workers with and without dental insurance in a national social security scheme in India.

PubMed

Singh, Abhinav; Purohit, Bharathi M; Masih, Nitin; Kahndelwal, Praveen Kumar

2014-04-01

The target population for this cross sectional study comprises subjects with and without social security in a national social security scheme. The study aimed to compare and assess the risk factors for oral diseases among insured (organised sector) and non-insured workers (unorganised sector) in New Delhi, India. The sample comprised a total of 2,752 subjects. Of these, 960 workers belonged to the formal or organised sector with a social security and dental health insurance and 1,792 had no social security or dental insurance from the informal or unorganised sector. Significant differences were noted between the two groups for literacy levels, between-meal sugar consumption, tobacco-related habits and utilisation of dental care. Bleeding/calculus and periodontal pockets were present among 25% and 65.4% of insured workers, respectively. Similarly, 13.6% and 84.5% of non-insured workers had bleeding/calculus and periodontal pockets, respectively. The mean DMFT (decayed, missing, filled teeth) value among the insured workers and non-insured workers was 3.27 ± 1.98 and 3.75 ± 1.80, respectively. The association between absence of health insurance and dental caries was evident with an odds ratio (OR) of 1.94. Subjects with below graduate education were more prone to dental caries (OR = 1.62). Subjects who cleaned their teeth two or more times a day were less likely to have dental caries (OR = 1.47). Utilisation of dental care was inversely related to dental caries (OR = 1.25). The major risk factors for oral diseases in both the groups with similar socio-economic status were the lack of social security and health insurance, low literacy levels, high tobacco consumption and low levels of dental care utilisation. © 2013 FDI World Dental Federation.
Risk distribution across multiple health insurance funds in rural Tanzania.

PubMed

Chomi, Eunice Nahyuha; Mujinja, Phares Gamba; Enemark, Ulrika; Hansen, Kristian; Kiwara, Angwara Dennis

2014-01-01

Multiple insurance funds serving different population groups may compromise equity due to differential revenue raising capacity and an unequal distribution of high risk members among the funds. This occurs when the funds exist without mechanisms in place to promote income and risk cross-subsidisation across the funds. This paper analyses whether the risk distribution varies across the Community Health Fund (CHF) and National Health Insurance Fund (NHIF) in two districts in Tanzania. Specifically we aim to 1) identify risk factors associated with increased utilisation of health services and 2) compare the distribution of identified risk factors among the CHF, NHIF and non-member households. Data was collected from a survey of 695 households. A multivariate logisitic regression model was used to identify risk factors for increased health care utilisation. Chi-square tests were performed to test whether the distribution of identified risk factors varied across the CHF, NHIF and non-member households. There was a higher concentration of identified risk factors among CHF households compared to those of the NHIF. Non-member households have a similar wealth status to CHF households, but a lower concentration of identified risk factors. Mechanisms for broader risk spreading and cross-subsidisation across the funds are necessary for the promotion of equity. These include risk equalisation to adjust for differential risk distribution and revenue raising capacity of the funds. Expansion of CHF coverage is equally important, by addressing non-financial barriers to CHF enrolment to encourage wealthy non-members to join, as well as subsidised membership for the poorest.
Factors affecting performance in an ultraendurance triathlon.

PubMed

Laursen, P B; Rhodes, E C

2001-01-01

In the recent past, researchers have found many key physiological variables that correlate highly with endurance performance. These include maximal oxygen uptake (VO2max), anaerobic threshold (AT), economy of motion and the fractional utilisation of oxygen uptake (VO2). However, beyond typical endurance events such as the marathon, termed 'ultraendurance' (i.e. >4 hours), performance becomes harder to predict. The ultraendurance triathlon (UET) is a 3-sport event consisting of a 3.8 km swim and a 180 km cycle, followed by a 42.2 km marathon run. It has been hypothesised that these triathletes ride at approximately their ventilatory threshold (Tvent) during the UET cycling phase. However, laboratory assessments of cycling time to exhaustion at a subject's AT peak at 255 minutes. This suggests that the AT is too great an intensity to be maintained during a UET, and that other factors cause detriments in prolonged performance. Potential defeating factors include the provision of fuels and fluids due to finite gastric emptying rates causing changes in substrate utilisation, as well as fluid and electrolyte imbalances. Thus, an optimum ultraendurance intensity that may be relative to the AT intensity is needed to establish ultraendurance intensity guidelines. This optimal UET intensity could be referred to as the ultraendurance threshold.
Performance of a multistep fluorescence-gated proportional counter for hard X-ray astronomy

NASA Technical Reports Server (NTRS)

Dietz, K. L.; Ramsey, B. D.; Weisskopf, M. C.

1992-01-01

Results from the first flight of our proportional counter in an imaging telescope led us to rebuild the detector. We have used a Penning gas mixture (xenon + 1 percent isobutylene) and introduced a preamplification region to improve the energy resolution. We have rebuilt the pressure vessel making novel use of molybdenum as the housing material in order to reduce the residual instrument background, particularly in the fluorescence-gated mode for which the detector design has been optimized. We have also increased the sensitive gas depth from 9 to 14 cm to further increase the sensitivity to both fluorescent pairs and conventional singles. Our calibrations have shown that the overall energy resolution of the detector has been enhanced by a factor of 2, and we predict that the sensitivity at float will increase by a factor of 3 in the 50-70 keV energy band.
49 CFR 234.255 - Gate arm and gate mechanism.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Gate arm and gate mechanism. 234.255 Section 234... Maintenance, Inspection, and Testing Inspections and Tests § 234.255 Gate arm and gate mechanism. (a) Each gate arm and gate mechanism shall be inspected at least once each month. (b) Gate arm movement shall be...
49 CFR 234.255 - Gate arm and gate mechanism.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Gate arm and gate mechanism. 234.255 Section 234... Maintenance, Inspection, and Testing Inspections and Tests § 234.255 Gate arm and gate mechanism. (a) Each gate arm and gate mechanism shall be inspected at least once each month. (b) Gate arm movement shall be...
49 CFR 234.255 - Gate arm and gate mechanism.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Gate arm and gate mechanism. 234.255 Section 234....255 Gate arm and gate mechanism. (a) Each gate arm and gate mechanism shall be inspected at least once each month. (b) Gate arm movement shall be observed for proper operation at least once each month. (c...
49 CFR 234.255 - Gate arm and gate mechanism.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Gate arm and gate mechanism. 234.255 Section 234....255 Gate arm and gate mechanism. (a) Each gate arm and gate mechanism shall be inspected at least once each month. (b) Gate arm movement shall be observed for proper operation at least once each month. (c...
49 CFR 234.255 - Gate arm and gate mechanism.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Gate arm and gate mechanism. 234.255 Section 234....255 Gate arm and gate mechanism. (a) Each gate arm and gate mechanism shall be inspected at least once each month. (b) Gate arm movement shall be observed for proper operation at least once each month. (c...
Outpatient echocardiography in the evaluation of innocent murmurs in children: utilisation benchmarking.

PubMed

Frias, Patricio A; Oster, Matthew; Daley, Patricia A; Boris, Jeffrey R

2016-03-01

We sought to benchmark the utilisation of echocardiography in the outpatient evaluation of heart murmurs by evaluating two large paediatric cardiology centres. Although criteria exist for appropriate use of echocardiography, there are no benchmarking data demonstrating its utilisation. We performed a retrospective cohort study of outpatients aged between 0 and 18 years at the Sibley Heart Center Cardiology and the Children's Hospital of Philadelphia Division of Cardiology, given a sole diagnosis of "innocent murmur" from 1 July, 2007 to 31 October, 2010. Using internal claims data, we compared the utilisation of echocardiography according to centre, patient age, and physician years of service. Of 23,114 eligible patients (Sibley Heart Center Cardiology: 12,815, Children's Hospital of Philadelphia Division of Cardiology: 10,299), 43.1% (Sibley Heart Center Cardiology: 45.2%, Children's Hospital of Philadelphia Division of Cardiology: 40.4%; p1-5 years had the lowest utilisation (32.7%). In two large paediatric cardiology practices, the overall utilisation of echocardiography by physicians with a sole diagnosis of innocent murmur was similar. There was significant and similar variability in utilisation by provider at both centres. Although these data serve as initial benchmarking, the variability in utilisation highlights the importance of appropriate use criteria.
Cytogenetic description of the earthworm Drawida ghilarovi Gates, 1969 (Oligochaeta, Moniligastridae) from the southern Russian Far East

PubMed Central

Anisimov, Alim P.; Roslik, Galina V.; Ganin, Gennady N.

2015-01-01

Abstract Sixty-six specimens of the earthworm Drawida ghilarovi Gates, 1969 (Oligochaeta, Moniligastridae) from 15 localities of the southern Russian Far East were studied cytogenetically. We examined chromosome sets during mitosis and diakinesis as well as DNA content in the spermatogenous and somatic cell nuclei. The populations and morphs displayed no differences in karyotype and ploidy levels estimated in terms of both chromosome number and DNA mass index: n = 10, 2n = 20; c = 1.1 pg, 2c = 2.2 pg. We conclude that polyploidy as a species- or race-forming factor is not typical of these earthworms. PMID:26753075
Blood pressure and risk of cancer progression - A possible connection with salt and voltage-gated sodium channel.

PubMed

Djamgoz, Mustafa B A

2015-11-01

Although it is well known that high blood pressure promotes cancer, the underlying cause(s) is not well understood. Here, we advance the hypothesis that the extracellular sodium level could be a contributing factor. The hypothesis is based upon emerging evidence showing (i) that voltage-gated sodium channels are expressed de novo in cancer cells and tissues, and (ii) that the influx of sodium from the extracellular medium into cancer cells, mediated by the channel activity, promotes their metastatic potential. Clinical and lifestyle implications of the hypothesis are discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.
Model approaches for estimating the influence of time-varying socio-environmental factors on macroparasite transmission in two endemic regions

PubMed Central

ZHONG, BO; CARLTON, ELIZABETH J.; SPEAR, ROBERT C.

2009-01-01

The environmental determinants of vector- and host-borne diseases include time-varying components that modify key transmission parameters, resulting in transient couplings between environmental phenomena and transmission processes. While some time-varying drivers are periodic in nature, some are aperiodic, such as those that involve episodic events or complex patterns of human behavior. Understanding these couplings can allow for prediction of periods of peak infection risk, and ultimately presents opportunities for optimizing intervention selection and timing. Schistosome macroparasites of humans exhibit multiple free-living stages as well as intermediate hosts, and are thus model organisms for illustrating the influence of environmental forcing on transmission. Time-varying environmental factors, termed gating functions, for schistosomes include larval response to temperature and rainfall, seasonal water contact patterns and snail population dynamics driven by weather variables. The biological bases for these modifiers are reviewed, and their values are estimated and incorporated into a transmission model that simulates a multi-year period in two schistosomiasis endemic regions. Modeling results combined with a scale dependent correlation analysis indicate the end effect of these site-specific gating functions is to strongly govern worm burden in these communities, in a manner particularly sensitive to the hydrological differences between sites. Two classes of gating functions were identified, those that act in concert to modify human infection (and determine worm acquisition late in the season), and those that act on snail infection (and determine early season worm acquisition). The importance of these factors for control programs and surveillance is discussed. PMID:20454601
Integrated nuclear data utilisation system for innovative reactors.

PubMed

Yamano, N; Hasegawa, A; Kato, K; Igashira, M

2005-01-01

A five-year research and development project on an integrated nuclear data utilisation system was initiated in 2002, for developing innovative nuclear energy systems such as accelerator-driven systems. The integrated nuclear data utilisation system will be constructed as a modular code system, which consists of two sub-systems: the nuclear data search and plotting sub-system, and the nuclear data processing and utilisation sub-system. The system will be operated with a graphical user interface in order to enable easy utilisation through the Internet by both nuclear design engineers and nuclear data evaluators. This paper presents an overview of the integrated nuclear data utilisation system, describes the development of a prototype system to examine the operability of the user interface and discusses specifications of the two sub-systems.
e-Portfolios Enhancing Students' Self-Directed Learning: A Systematic Review of Influencing Factors

ERIC Educational Resources Information Center

Beckers, Jorrick; Dolmans, Diana; Van Merriënboer, Jeroen

2016-01-01

e-Portfolios have become increasingly popular among educators as learning tools. Some research even shows that e-portfolios can be utilised to facilitate the development of skills for self-directed learning. Such skills include self-assessment of performance, formulation of learning goals, and selection of future tasks. However, it is not yet…
Identifying Ghanaian Pre-Service Teachers' Readiness for Computer Use: A Technology Acceptance Model Approach

ERIC Educational Resources Information Center

Gyamfi, Stephen Adu

2016-01-01

This study extends the technology acceptance model to identify factors that influence technology acceptance among pre-service teachers in Ghana. Data from 380 usable questionnaires were tested against the research model. Utilising the extended technology acceptance model (TAM) as a research framework, the study found that: pre-service teachers'…
Solution processed flexible organic thin film back-gated transistors based on polyimide dielectric films

NASA Astrophysics Data System (ADS)

Park, Janghoon; Min, Yoonki; Lee, Dongjin

2018-04-01

An organic thin film back-gated transistor (OBGT) was fabricated and characterized. The gate electrode was printed on the back side of substrate, and the dielectric layer was omitted by substituting the dielectric layer with the polyimide (PI) film substrate. Roll-to-roll (R2R) gravure printing, doctor blading, and drop casting methods were used to fabricate the OBGT. The printed OBGT device shows better performance compared with an OTFT device based on dielectric layer of BaTiO3. Additionally, a calendering process enhanced the performance by a factor of 3 to 7 (mobility: 0.016 cm2/V.s, on/off ratio: 9.17×103). A bending test was conducted to confirm the flexibility and durability of the OBGT device. The results show the fabricated device endures 20000-cyclic motions. The realized OBGT device was successfully fabricated and working, which is meaningful for production engineering from the viewpoint of process development.
Ultrasound measurement of the brachial artery flow-mediated dilation without ECG gating.

PubMed

Gemignani, Vincenzo; Bianchini, Elisabetta; Faita, Francesco; Giannarelli, Chiara; Plantinga, Yvonne; Ghiadoni, Lorenzo; Demi, Marcello

2008-03-01

The methods commonly used for noninvasive ultrasound assessment of endothelium-dependent flow-mediated dilation (FMD) require an electrocardiogram (ECG) signal to synchronize the measurements with the cardiac cycle. In this article, we present a method for assessing FMD that does not require ECG gating. The approach is based on temporal filtering of the diameter-time curve, which is obtained by means of a B-mode image processing system. The method was tested on 22 healthy volunteers without cardiovascular risk factors. The measurements obtained with the proposed approach were compared with those obtained with ECG gating and with both systolic and end-diastolic measurements. Results showed good agreement between the methods and a higher precision of the new method due to the fact that it is based on a larger number of measurements. Further advantages were also found both in terms of reliability of the measure and simplification of the instrumentation. (E-mail: gemi@ifc.cnr.it).
Elastomeric microvalve geometry affects haemocompatibility.

PubMed

Szydzik, Crispin; Brazilek, Rose J; Khoshmanesh, Khashayar; Akbaridoust, Farzan; Knoerzer, Markus; Thurgood, Peter; Muir, Ineke; Marusic, Ivan; Nandurkar, Harshal; Mitchell, Arnan; Nesbitt, Warwick S

2018-06-12

This paper reports on the parameters that determine the haemocompatibility of elastomeric microvalves for blood handling in microfluidic systems. Using a comprehensive investigation of blood function, we describe a hierarchy of haemocompatibility as a function of microvalve geometry and identify a "normally-closed" v-gate pneumatic microvalve design that minimally affects blood plasma fibrinogen and von Willebrand factor composition, minimises effects on erythrocyte structure and function, and limits effects on platelet activation and aggregation, while facilitating rapid switching control for blood sample delivery. We propose that the haemodynamic profile of valve gate geometries is a significant determinant of platelet-dependent biofouling and haemocompatibility. Overall our findings suggest that modification of microvalve gate geometry and consequently haemodynamic profile can improve haemocompatibility, while minimising the requirement for chemical or protein modification of microfluidic surfaces. This biological insight and approach may be harnessed to inform future haemocompatible microfluidic valve and component design, and is an advance towards lab-on-chip automation for blood based diagnostic systems.
Structures of FolT in substrate-bound and substrate-released conformations reveal a gating mechanism for ECF transporters

NASA Astrophysics Data System (ADS)

Zhao, Qin; Wang, Chengcheng; Wang, Chengyuan; Guo, Hui; Bao, Zhihao; Zhang, Minhua; Zhang, Peng

2015-07-01

Energy-coupling factor (ECF) transporters are a new family of ABC transporters that consist of four subunits, two cytoplasmic ATPases EcfA and EcfA' and two transmembrane proteins namely EcfS for substrate-specific binding and EcfT for energy coupling. Here, we report the 3.2-Å resolution crystal structure of the EcfS protein of a folate ECF transporter from Enterococcus faecalis-EfFolT, a close homologue of FolT from Lactobacillus brevis-LbFolT. Structural and biochemical analyses reveal the residues constituting the folate-binding pocket and determining the substrate-binding specificity. Structural comparison of the folate-bound EfFolT with the folate-free LbFolT contained in the holotransporter complex discloses significant conformational change at the L1 loop, and reveals a gating mechanism of ECF transporters in which the L1 loop of EcfS acts as a gate in the substrate binding and release.

Kinetic gating mechanism of DNA damage recognition by Rad4/XPC

NASA Astrophysics Data System (ADS)

Chen, Xuejing; Velmurugu, Yogambigai; Zheng, Guanqun; Park, Beomseok; Shim, Yoonjung; Kim, Youngchang; Liu, Lili; van Houten, Bennett; He, Chuan; Ansari, Anjum; Min, Jung-Hyun

2015-01-01

The xeroderma pigmentosum C (XPC) complex initiates nucleotide excision repair by recognizing DNA lesions before recruiting downstream factors. How XPC detects structurally diverse lesions embedded within normal DNA is unknown. Here we present a crystal structure that captures the yeast XPC orthologue (Rad4) on a single register of undamaged DNA. The structure shows that a disulphide-tethered Rad4 flips out normal nucleotides and adopts a conformation similar to that seen with damaged DNA. Contrary to many DNA repair enzymes that can directly reject non-target sites as structural misfits, our results suggest that Rad4/XPC uses a kinetic gating mechanism whereby lesion selectivity arises from the kinetic competition between DNA opening and the residence time of Rad4/XPC per site. This mechanism is further supported by measurements of Rad4-induced lesion-opening times using temperature-jump perturbation spectroscopy. Kinetic gating may be a general mechanism used by site-specific DNA-binding proteins to minimize time-consuming interrogations of non-target sites.
Experimental determination of the impact of polysilicon LER on sub-100-nm transistor performance

NASA Astrophysics Data System (ADS)

Patterson, Kyle; Sturtevant, John L.; Alvis, John R.; Benavides, Nancy; Bonser, Douglas; Cave, Nigel; Nelson-Thomas, Carla; Taylor, William D.; Turnquest, Karen L.

2001-08-01

Photoresist line edge roughness (LER) has long been feared as a potential limitation to the application of various patterning technologies to actual devices. While this concern seems reasonable, experimental verification has proved elusive and thus LER specifications are typically without solid parametric rationale. We report here the transistor device performance impact of deliberate variations of polysilicon gate LER. LER magnitude was attenuated by more than a factor of 5 by altering the photoresist type and thickness, substrate reflectivity, masking approach, and etch process. The polysilicon gate LER for nominally 70 - 150 nm devices was quantified using digital image processing of SEM images, and compared to gate leakage and drive current for variable length and width transistors. With such comparisons, realistic LER specifications can be made for a given transistor. It was found that subtle cosmetic LER differences are often not discernable electrically, thus providing hope that LER will not limit transistor performance as the industry migrates to sub-100 nm patterning.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Hyun-Sik; Jeon, Sanghun, E-mail: jeonsh@korea.ac.kr

Upon light exposure, an indium-zinc-oxide (IZO) thin-film transistor (TFT) presents higher photoconductivity by several orders of magnitude at the negative gate bias region. Among various device geometrical factors, scaling down the channel length of the photo-transistor results in an anomalous increase in photoconductivity. To probe the origin of this high photoconductivity in short-channel device, we measured transient current, current–voltage, and capacitance–voltage characteristics of IZO–TFTs with various channel lengths and widths before and after illumination. Under the illumination, the equilibrium potential region which lies far from front interface exists only in short-channel devices, forming the un-depleted conducting back channel. This regionmore » plays an important role in carrier transport under the illumination, leading to high photoconductivity in short-channel devices. Photon exposure coupled with gate-modulated band bending for short-channel devices leads to the accumulation of V{sub o}{sup ++} at the front channel and screening negative gate bias, thereby generating high current flow in the un-depleted back-channel region.« less
CMOS image sensor with lateral electric field modulation pixels for fluorescence lifetime imaging with sub-nanosecond time response

NASA Astrophysics Data System (ADS)

Li, Zhuo; Seo, Min-Woong; Kagawa, Keiichiro; Yasutomi, Keita; Kawahito, Shoji

2016-04-01

This paper presents the design and implementation of a time-resolved CMOS image sensor with a high-speed lateral electric field modulation (LEFM) gating structure for time domain fluorescence lifetime measurement. Time-windowed signal charge can be transferred from a pinned photodiode (PPD) to a pinned storage diode (PSD) by turning on a pair of transfer gates, which are situated beside the channel. Unwanted signal charge can be drained from the PPD to the drain by turning on another pair of gates. The pixel array contains 512 (V) × 310 (H) pixels with 5.6 × 5.6 µm2 pixel size. The imager chip was fabricated using 0.11 µm CMOS image sensor process technology. The prototype sensor has a time response of 150 ps at 374 nm. The fill factor of the pixels is 5.6%. The usefulness of the prototype sensor is demonstrated for fluorescence lifetime imaging through simulation and measurement results.
Dependence of Mobility on Density of Gap States in Organics by GAMEaS - Gate Modulated Activation Energy Spectroscopy

NASA Astrophysics Data System (ADS)

So, Woo-Young; Lang, David; Ramirez, Arthur

2008-03-01

We develop a spectroscopic method for determining the density of states (DOS) in the energy gap - GAte Modulated activation Energy Spectroscopy (GAMEaS), We also report the relationship of these gap states to the mobility of organic field-effect-transistors (FETs). We find that the field-effect mobility is parameterized by two factors: (1) the free-carrier mobility and (2) the ratio of the free carrier density to the total carrier density induced by the gate bias. We show that the highest mobility FETs have shallow exponential band tails of localized states with characteristic slope of 1/kT at 300K. Most remarkably, state-of-the-art crystalline FETs fabricated from rubrene, pentacene, and tetracene all have a very high free-carrier mobility, up to 200cm2/Vsec at 300K, with the somewhat lower effective mobilities dominated by localized gap states. This strongly suggests that further improvements in device performance could be possible with enhanced material quality.
Gate-controlled quantum collimation in nanocolumn resonant tunneling transistors.

PubMed

Wensorra, J; Lepsa, M I; Trellenkamp, S; Moers, J; Indlekofer, K M; Lüth, H

2009-11-18

Nanoscaled resonant tunneling transistors (RTT) based on MBE-grown GaAs/AlAs double-barrier quantum well (DBQW) structures have been fabricated by a top-down approach using electron-beam lithographic definition of the vertical nanocolumns. In the preparation process, a reproducible mask alignment accuracy of below 10 nm has been achieved and the all-around metal gate at the level of the DBQW structure has been positioned at a distance of about 20 nm relative to the semiconductor nanocolumn. Due to the specific doping profile n++/i/n++ along the transistor nanocolumn, a particular confining potential is established for devices with diameters smaller than 70 nm, which causes a collimation effect of the propagating electrons. Under these conditions, room temperature optimum performance of the nano-RTTs is achieved with peak-to-valley current ratios above 2 and a peak current swing factor of about 6 for gate voltages between -6 and +6 V. These values indicate that our nano-RTTs can be successfully used in low power fast nanoelectronic circuits.
Kinetic gating mechanism of DNA damage recognition by Rad4/XPC

DOE PAGES

Chen, Xuejing; Velmurugu, Yogambigai; Zheng, Guanqun; ...

2015-01-06

The xeroderma pigmentosum C (XPC) complex initiates nucleotide excision repair by recognizing DNA lesions before recruiting downstream factors. How XPC detects structurally diverse lesions embedded within normal DNA is unknown. Here we present a crystal structure that captures the yeast XPC orthologue (Rad4) on a single register of undamaged DNA. The structure shows that a disulphide-tethered Rad4 flips out normal nucleotides and adopts a conformation similar to that seen with damaged DNA. Contrary to many DNA repair enzymes that can directly reject non-target sites as structural misfits, our results suggest that Rad4/XPC uses a kinetic gating mechanism whereby lesion selectivitymore » arises from the kinetic competition between DNA opening and the residence time of Rad4/XPC per site. This mechanism is further supported by measurements of Rad4-induced lesion-opening times using temperature-jump perturbation spectroscopy. Lastly, kinetic gating may be a general mechanism used by site-specific DNA-binding proteins to minimize time-consuming interrogations of non-target sites.« less
Highly Mobile Two-Dimensional Electron Gases with a Strong Gating Effect at the Amorphous LaAlO3/KTaO3 Interface.

PubMed

Zhang, Hui; Zhang, Hongrui; Yan, Xi; Zhang, Xuejing; Zhang, Qinghua; Zhang, Jing; Han, Furong; Gu, Lin; Liu, Banggui; Chen, Yuansha; Shen, Baogen; Sun, Jirong

2017-10-18

Two-dimensional electron gas (2DEG) at the perovskite oxide interface exhibits a lot of exotic properties, presenting a promising platform for the exploration of emergent phenomena. While most of the previous works focused on SrTiO 3 -based 2DEG, here we report on the fabrication of high-quality 2DEGs by growing an amorphous LaAlO 3 layer on a (001)-orientated KTaO 3 substrate, which is a 5d metal oxide with a polar surface, at a high temperature that is usually adopted for crystalline LaAlO 3 . Metallic 2DEGs with a Hall mobility as high as ∼2150 cm 2 /(V s) and a sheet carrier density as low as 2 × 10 12 cm -2 are obtained. For the first time, the gating effect on the transport process is studied, and its influence on spin relaxation and inelastic and elastic scattering is determined. Remarkably, the spin relaxation time can be strongly tuned by a back gate. It is reduced by a factor of ∼69 while the gate voltage is swept from -25 to +100 V. The mechanism that dominates the spin relaxation is elucidated.
Highly Stable, Dual-Gated MoS2 Transistors Encapsulated by Hexagonal Boron Nitride with Gate-Controllable Contact, Resistance, and Threshold Voltage.

PubMed

Lee, Gwan-Hyoung; Cui, Xu; Kim, Young Duck; Arefe, Ghidewon; Zhang, Xian; Lee, Chul-Ho; Ye, Fan; Watanabe, Kenji; Taniguchi, Takashi; Kim, Philip; Hone, James

2015-07-28

Emerging two-dimensional (2D) semiconductors such as molybdenum disulfide (MoS2) have been intensively studied because of their novel properties for advanced electronics and optoelectronics. However, 2D materials are by nature sensitive to environmental influences, such as temperature, humidity, adsorbates, and trapped charges in neighboring dielectrics. Therefore, it is crucial to develop device architectures that provide both high performance and long-term stability. Here we report high performance of dual-gated van der Waals (vdW) heterostructure devices in which MoS2 layers are fully encapsulated by hexagonal boron nitride (hBN) and contacts are formed using graphene. The hBN-encapsulation provides excellent protection from environmental factors, resulting in highly stable device performance, even at elevated temperatures. Our measurements also reveal high-quality electrical contacts and reduced hysteresis, leading to high two-terminal carrier mobility (33-151 cm(2) V(-1) s(-1)) and low subthreshold swing (80 mV/dec) at room temperature. Furthermore, adjustment of graphene Fermi level and use of dual gates enable us to separately control contact resistance and threshold voltage. This novel vdW heterostructure device opens up a new way toward fabrication of stable, high-performance devices based on 2D materials.
A novel low temperature soft reflow process for the fabrication of deep-submicron (<0.35 μm) T-gate pseudomorphic high electron mobility transistor structures

NASA Astrophysics Data System (ADS)

Ian, Ka Wa; Exarchos, Michael; Missous, Mohamed

2013-02-01

We report a new and simple low temperature soft reflow process using solvent vapour. The combination of this soft reflow and conventional i-line lithography enables low cost, highly efficient fabrication at the deep-submicron scale. Compared to the conventional thermal reflow process, the key benefits of the new soft reflow process are its low temperature operation (<50 °C), greater shrinkage of the structure size (up to 75%) and better controllability. Gate openings reflowed from 1 μm to 250 nm have been routinely and reproducibly achieved by utilizing the saturation characteristics of the process. The feasibility of this soft reflow process is demonstrated in the fabrication of a 350 nm T-gate pseudomorphic high electron mobility transistor. By shrinking the gate length by a factor of three (from a 1 μm initial opening), the output current is improved by 60% (500 mA mm-1 from 300 mA mm-1) and fT and fMAX are increased to 70 GHz (from 20 GHz) and 120 GHz (from 40 GHz) respectively. The proposed soft reflow could potentially be applied on other compatible substrates such as polymer based material for organic or thin film devices, potentially leading to many new possible applications.
Gate-controlled tunneling of quantum Hall edge states in bilayer graphene

NASA Astrophysics Data System (ADS)

Zhu, Jun; Li, Jing; Wen, Hua

Controlled tunneling of integer and fractional quantum Hall edge states provides a powerful tool to probe the physics of 1D systems and exotic particle statistics. Experiments in GaAs 2DEGs employ either a quantum point contact or a line junction tunnel barrier. It is generally difficult to independently control the filling factors νL and νR on the two sides of the barrier. Here we show that in bilayer graphene both νL and νR as well as their Landau level structures can be independently controlled using a dual-split-gate structure. In addition, the height of the line-junction tunnel barrier implemented in our experiments is tunable via a 5th gate. By measuring the tunneling resistance across the junction RT we examine the equilibration of the edge states in a variety of νL/νR scenarios and under different barrier heights. Edge states from both sides are fully mixed in the case of a low barrier. As the barrier height increases, we observe plateaus in RT that correspond to sequential complete backscattering of edge states. Gate-controlled manipulation of edge states offers a new angle to the exploration of quantum Hall magnetism and fractional quantum Hall effect in bilayer graphene.
Chrestenson transform FPGA embedded factorizations.

PubMed

Corinthios, Michael J

2016-01-01

Chrestenson generalized Walsh transform factorizations for parallel processing imbedded implementations on field programmable gate arrays are presented. This general base transform, sometimes referred to as the Discrete Chrestenson transform, has received special attention in recent years. In fact, the Discrete Fourier transform and Walsh-Hadamard transform are but special cases of the Chrestenson generalized Walsh transform. Rotations of a base-p hypercube, where p is an arbitrary integer, are shown to produce dynamic contention-free memory allocation, in processor architecture. The approach is illustrated by factorizations involving the processing of matrices of the transform which are function of four variables. Parallel operations are implemented matrix multiplications. Each matrix, of dimension N × N, where N = p (n) , n integer, has a structure that depends on a variable parameter k that denotes the iteration number in the factorization process. The level of parallelism, in the form of M = p (m) processors can be chosen arbitrarily by varying m between zero to its maximum value of n - 1. The result is an equation describing the generalised parallelism factorization as a function of the four variables n, p, k and m. Applications of the approach are shown in relation to configuring field programmable gate arrays for digital signal processing applications.
Barrier, weakness and utilization of pre-pregnancy clinic services.

PubMed

Rahman, Mizanur; Rahim, Natazcza Abdul; Arif, Mohd Taha

2017-01-01

Despite being one of the plausible measures towards achieving Sustainable Development Goals (SDGs), various issues pertaining to pre-pregnancy clinic (PPC) services still need to be pondered upon. Based on this view, an attempt was made to identify and understand the barriers and weaknesses of current utilisation of pre-pregnancy care services, since its establishment and implementation in Sarawak from the year 2011. This cross-sectional study was conducted in selected health care facilities throughout Sarawak. A multistage cluster sampling technique was followed to select the health facilities. An unstructured open-ended questionnaire was administered as a part of quantitative data analysis. The open-ended questions were administered to get the in-depth perceived views and current practice of utilisation of pre-pregnancy clinic services. A total of 553 clients from nine selected health care facilities gave their feedback. The results of the study were narrated in textual form and a thematic analysis was done manually. The identified themes for perceived barriers for utilisation of pre-pregnancy care were perception, attitude and acceptance of PPC services, socio-economic issues, services and client factors. The perceived weaknesses of the services are listed under two main themes: working environment and service factors, whereas, the strength of services produced three thematic areas which are preparation for pregnancy, prevention of mortality and morbidity and comprehensive services. Though there is ample evidence that pre-pregnancy services are beneficial for maternal health and wellbeing, various issues still need to be addressed for the improvement of the quality of services. Lack of awareness among clients, socio-economic barriers, lack of resources, organisational barriers and perceptions towards family planning issues are some of the issues which need to be addressed. Nonetheless, promotional and health educational activities are important keys; in ensuring the sustainability of the services.
Motion mitigation for lung cancer patients treated with active scanning proton therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grassberger, Clemens, E-mail: Grassberger.Clemens@mgh.harvard.edu; Dowdell, Stephen; Sharp, Greg

2015-05-15

Purpose: Motion interplay can affect the tumor dose in scanned proton beam therapy. This study assesses the ability of rescanning and gating to mitigate interplay effects during lung treatments. Methods: The treatments of five lung cancer patients [48 Gy(RBE)/4fx] with varying tumor size (21.1–82.3 cm{sup 3}) and motion amplitude (2.9–30.6 mm) were simulated employing 4D Monte Carlo. The authors investigated two spot sizes (σ ∼ 12 and ∼3 mm), three rescanning techniques (layered, volumetric, breath-sampled volumetric) and respiratory gating with a 30% duty cycle. Results: For 4/5 patients, layered rescanning 6/2 times (for the small/large spot size) maintains equivalent uniformmore » dose within the target >98% for a single fraction. Breath sampling the timing of rescanning is ∼2 times more effective than the same number of continuous rescans. Volumetric rescanning is sensitive to synchronization effects, which was observed in 3/5 patients, though not for layered rescanning. For the large spot size, rescanning compared favorably with gating in terms of time requirements, i.e., 2x-rescanning is on average a factor ∼2.6 faster than gating for this scenario. For the small spot size however, 6x-rescanning takes on average 65% longer compared to gating. Rescanning has no effect on normal lung V{sub 20} and mean lung dose (MLD), though it reduces the maximum lung dose by on average 6.9 ± 2.4/16.7 ± 12.2 Gy(RBE) for the large and small spot sizes, respectively. Gating leads to a similar reduction in maximum dose and additionally reduces V{sub 20} and MLD. Breath-sampled rescanning is most successful in reducing the maximum dose to the normal lung. Conclusions: Both rescanning (2–6 times, depending on the beam size) as well as gating was able to mitigate interplay effects in the target for 4/5 patients studied. Layered rescanning is superior to volumetric rescanning, as the latter suffers from synchronization effects in 3/5 patients studied. Gating minimizes the irradiated volume of normal lung more efficiently, while breath-sampled rescanning is superior in reducing maximum doses to organs at risk.« less
Associations between socioeconomic status and primary total knee joint replacements performed for osteoarthritis across Australia 2003-10: data from the Australian Orthopaedic Association National Joint Replacement Registry.

PubMed

Brennan, Sharon L; Lane, Stephen E; Lorimer, Michelle; Buchbinder, Rachelle; Wluka, Anita E; Page, Richard S; Osborne, Richard H; Pasco, Julie A; Sanders, Kerrie M; Cashman, Kara; Ebeling, Peter R; Graves, Stephen E

2014-10-28

Relatively little is known about the social distribution of total knee joint replacement (TKR) uptake in Australia. We examine associations between socioeconomic status (SES) and TKR performed for diagnosed osteoarthritis 2003-10 for all Australian males and females aged ≥ 30 yr. Data of primary TKR (n=213,018, 57.4% female) were ascertained from a comprehensive national joint replacement registry. Residential addresses were matched to Australian Census data to identify area-level social disadvantage, and categorised into deciles. Estimated TKR rates were calculated. Poisson regression was used to model the relative risk (RR) of age-adjusted TKR per 1,000py, stratified by sex and SES. A negative relationship was observed between TKR rates and SES deciles. Females had a greater rate of TKR than males. Surgery utilisation was greatest for all adults aged 70-79 yr. In that age group differences in estimated TKR per 1,000py between deciles were greater for 2010 than 2003 (females: 2010 RR 4.32 and 2003 RR 3.67; males: 2010 RR 2.04 and 2003 RR 1.78). Identifying factors associated with TKR utilisation and SES may enhance resource planning and promote surgery utilisation for end-stage osteoarthritis.
Sub 20 meV Schottky barriers in metal/MoTe2 junctions

NASA Astrophysics Data System (ADS)

Townsend, Nicola J.; Amit, Iddo; Craciun, Monica F.; Russo, Saverio

2018-04-01

The newly emerging class of atomically-thin materials has shown a high potential for the realisation of novel electronic and optoelectronic components. Amongst this family, semiconducting transition metal dichalcogenides (TMDCs) are of particular interest. While their band gaps are compatible with those of conventional solid state devices, they present a wide range of exciting new properties that is bound to become a crucial ingredient in the future of electronics. To utilise these properties for the prospect of electronics in general, and long-wavelength-based photodetectors in particular, the Schottky barriers formed upon contact with a metal and the contact resistance that arises at these interfaces have to be measured and controlled. We present experimental evidence for the formation of Schottky barriers as low as 10 meV between MoTe2 and metal electrodes. By varying the electrode work functions, we demonstrate that Fermi level pinning due to metal induced gap states at the interfaces occurs at 0.14 eV above the valence band maximum. In this configuration, thermionic emission is observed for the first time at temperatures between 40 K and 75 K. Finally, we discuss the ability to tune the barrier height using a gate electrode.
Sliding-gate valve for use with abrasive materials

DOEpatents

Ayers, Jr., William J.; Carter, Charles R.; Griffith, Richard A.; Loomis, Richard B.; Notestein, John E.

1985-01-01

The invention is a flow and pressure-sealing valve for use with abrasive solids. The valve embodies special features which provide for long, reliable operating lifetimes in solids-handling service. The valve includes upper and lower transversely slidable gates, contained in separate chambers. The upper gate provides a solids-flow control function, whereas the lower gate provides a pressure-sealing function. The lower gate is supported by means for (a) lifting that gate into sealing engagement with its seat when the gate is in its open and closed positions and (b) lowering the gate out of contact with its seat to permit abrasion-free transit of the gate between its open and closed positions. When closed, the upper gate isolates the lower gate from the solids. Because of this shielding action, the sealing surface of the lower gate is not exposed to solids during transit or when it is being lifted or lowered. The chamber containing the lower gate normally is pressurized slightly, and a sweep gas is directed inwardly across the lower-gate sealing surface during the vertical translation of the gate.
Time-gated FLIM microscope for corneal metabolic imaging

NASA Astrophysics Data System (ADS)

Silva, Susana F.; Batista, Ana; Domingues, José Paulo; Quadrado, Maria João.; Morgado, António Miguel

2016-03-01

Detecting corneal cells metabolic alterations may prove a valuable tool in the early diagnosis of corneal diseases. Nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) are autofluorescent metabolic co-factors that allow the assessment of metabolic changes through non-invasive optical methods. These co-factors exhibit double-exponential fluorescence decays, with well-separated short and lifetime components, which are related to their protein-bound and free-states. Corneal metabolism can be assessed by measuring the relative contributions of these two components. For that purpose, we have developed a wide-field time-gated fluorescence lifetime microscope based on structured illumination and one-photon excitation to record FAD lifetime images from corneas. NADH imaging was not considered as its UV excitation peak is regarded as not safe for in vivo measurements. The microscope relies on a pulsed blue diode laser (λ=443 nm) as excitation source, an ultra-high speed gated image intensifier coupled to a CCD camera to acquire fluorescence signals and a Digital Micromirror Device (DMD) to implement the Structured Illumination technique. The system has a lateral resolution better than 2.4 μm, a field of view of 160 per 120 μm and an optical sectioning of 6.91 +/- 0.45 μm when used with a 40x, 0.75 NA, Water Immersion Objective. With this setup we were able to measure FAD contributions from ex-vivo chicken corneas collected from a local slaughterhouse..
Hysteresis-Free Carbon Nanotube Field-Effect Transistors.

PubMed

Park, Rebecca S; Hills, Gage; Sohn, Joon; Mitra, Subhasish; Shulaker, Max M; Wong, H-S Philip

2017-05-23

While carbon nanotube (CNT) field-effect transistors (CNFETs) promise high-performance and energy-efficient digital systems, large hysteresis degrades these potential CNFET benefits. As hysteresis is caused by traps surrounding the CNTs, previous works have shown that clean interfaces that are free of traps are important to minimize hysteresis. Our previous findings on the sources and physics of hysteresis in CNFETs enabled us to understand the influence of gate dielectric scaling on hysteresis. To begin with, we validate through simulations how scaling the gate dielectric thickness results in greater-than-expected benefits in reducing hysteresis. Leveraging this insight, we experimentally demonstrate reducing hysteresis to <0.5% of the gate-source voltage sweep range using a very large-scale integration compatible and solid-state technology, simply by fabricating CNFETs with a thin effective oxide thickness of 1.6 nm. However, even with negligible hysteresis, large subthreshold swing is still observed in the CNFETs with multiple CNTs per transistor. We show that the cause of large subthreshold swing is due to threshold voltage variation between individual CNTs. We also show that the source of this threshold voltage variation is not explained solely by variations in CNT diameters (as is often ascribed). Rather, other factors unrelated to the CNTs themselves (i.e., process variations, random fixed charges at interfaces) are a significant factor in CNT threshold voltage variations and thus need to be further improved.
ESD protection design for advanced CMOS

NASA Astrophysics Data System (ADS)

Huang, Jin B.; Wang, Gewen

2001-10-01

ESD effects in integrated circuits have become a major concern as today's technologies shrink to sub-micron/deep- sub-micron dimensions. The thinner gate oxide and shallower junction depth used in the advanced technologies make them very vulnerable to ESD damages. The advanced techniques like silicidation and STI (shallow trench insulation) used for improving other device performances make ESD design even more challenging. For non-silicided technologies, a certain DCGS (drain contact to gate edge spacing) is needed to achieve ESD hardness for nMOS output drivers and nMOS protection transistors. The typical DCGS values are 4-5um and 2-3um for 0.5um and 0.25um CMOS, respectively. The silicidation reduces the ballast resistance provided by DCGS with at least a factor of 10. As a result, scaling of the ESD performance with device width is lost and even zero ESD performance is reported for standard silicided devices. The device level ESD design is focused in this paper, which includes GGNMOS (gate grounded NMOS) and GCNMOS (gate coupled NMOS). The device level ESD testing including TLP (transmission line pulse) is given. Several ESD issues caused by advanced technologies have been pointed out. The possible solutions have been developed and summarized including silicide blocking, process optimization, back-end ballasting, and new protection scheme, dummy gate/n-well resistor ballsting, etc. Some of them require process cost increase, and others provide novel, compact, and simple design but involving royalty/IP (intellectual property) issue. Circuit level ESD design and layout design considerations are covered. The top-level ESD protection strategies are also given.

Surfactant exfoliated 2D hexagonal Boron Nitride (2D-hBN) explored as a potential electrochemical sensor for dopamine: surfactants significantly influence sensor capabilities.

PubMed

Khan, Aamar F; Brownson, Dale A C; Foster, Christopher W; Smith, Graham C; Banks, Craig E

2017-05-21

Surfactant exfoliated 2D hexagonal Boron Nitride (2D-hBN) nanosheets are explored as a potential electrochemical sensing platform and evaluated towards the electroanalytical sensing of dopamine (DA) in the presence of the common interferents, ascorbic acid (AA) and uric acid (UA). Surfactant exfoliated 2D-hBN nanosheets (2-4 layers) fabricated using sodium cholate in aqueous media are electrically wired via a drop-casting modification process onto disposable screen-printed graphite electrodes (SPEs). We critically evaluate the performance of these 2D-hBN modified SPEs and demonstrate the effect of 'mass coverage' towards the detection of DA, AA and UA. Previous studies utilising surfactant-free (pristine) 2D-hBN modified SPEs have shown a beneficial effect towards the detection of DA, AA and UA when compared to the underlying/unmodified graphite-based electrode. We show that the fabrication route utilised to prepare 2D-hBN is a vital experimental consideration, such that the beneficial effect previously reported is considerably reduced when surfactant exfoliated 2D-hBN is utilised. We demonstrate for the first time, through implementation of control experiments in the form of surfactant modified graphite electrodes, that sodium cholate is a major contributing factor to the aforementioned detrimental behaviour. The significance here is not in the material per se, but the fundamental knowledge of the surfactant and surface coverage changing the electrochemical properties of the material under investigation. Given the wide variety of ionic and non-ionic surfactants that are utilised in the manufacture of novel 2D materials, the control experiments reported herein need to be performed in order to de-convolute the electrochemical response and effectively evaluate the 'underlying surface/surfactant/2D materials' electrocatalytic contribution.
A planning study investigating dual-gated volumetric arc stereotactic treatment of primary renal cell carcinoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Devereux, Thomas, E-mail: thomas.devereux@petermac.org; Pham, Daniel; Kron, Tomas

2015-04-01

This is a planning study investigating the dosimetric advantages of gated volumetric-modulated arc therapy (VMAT) to the end-exhale and end-inhale breathing phases for patients undergoing stereotactic treatment of primary renal cell carcinoma. VMAT plans were developed from the end-inhale (VMATinh) and the end-exhale (VMATexh) phases of the breathing cycle as well as a VMAT plan and 3-dimensional conformal radiation therapy plan based on an internal target volume (ITV) (VMATitv). An additional VMAT plan was created by giving the respective gated VMAT plan a 50% weighting and summing the inhale and exhale plans together to create a summed gated plan. Dosemore » to organs at risk (OARs) as well as comparison of intermediate and low-dose conformity was evaluated. There was no difference in the volume of healthy tissue receiving the prescribed dose for the planned target volume (PTV) (CI100%) for all the VMAT plans; however, the mean volume of healthy tissue receiving 50% of the prescribed dose for the PTV (CI50%) values were 4.7 (± 0.2), 4.6 (± 0.2), and 4.7 (± 0.6) for the VMATitv, VMATinh, and VMATexh plans, respectively. The VMAT plans based on the exhale and inhale breathing phases showed a 4.8% and 2.4% reduction in dose to 30 cm{sup 3} of the small bowel, respectively, compared with that of the ITV-based VMAT plan. The summed gated VMAT plans showed a 6.2% reduction in dose to 30 cm{sup 3} of the small bowel compared with that of the VMAT plans based on the ITV. Additionally, when compared with the inhale and the exhale VMAT plans, a 4% and 1.5%, respectively, reduction was observed. Gating VMAT was able to reduce the amount of prescribed, intermediate, and integral dose to healthy tissue when compared with VMAT plans based on an ITV. When summing the inhale and exhale plans together, dose to healthy tissue and OARs was optimized. However, gating VMAT plans would take longer to treat and is a factor that needs to be considered.« less
Chloride concentration affects Kv channel voltage-gating kinetics: Importance of experimental anion concentrations.

PubMed

Bekar, L K; Loewen, M E; Forsyth, G W; Walz, W

2005-09-30

Chloride concentration has been shown to have a dramatic impact on protein folding and subsequent tertiary conformation [K.D. Collins, Ions from the Hofmeister series and osmolytes: effects on proteins in solution and in the crystallization process, Methods 34 (2004) 300-311; I. Jelesarov, E. Durr, R.M. Thomas, H.R. Bosshard, Salt effects on hydrophobic interaction and charge screening in the folding of a negatively charged peptide to a coiled coil (leucine zipper), Biochemistry 37 (1998) 7539-7550]. As it is known that Kv channel gating is linked to the stability of the cytoplasmic T1 multimerization domain conformation [D.L. Minor, Y.F. Lin, B.C. Mobley, A. Avelar, Y.N. Jan, L.Y. Jan, J.M. Berger, The polar T1 interface is linked to conformational changes that open the voltage-gated potassium channel, Cell 102 (2000) 657-670; B.A. Yi, D.L. Minor Jr., Y.F. Lin, Y.N. Jan, L.Y. Jan, Controlling potassium channel activities: interplay between the membrane and intracellular factors, Proc. Natl. Acad. Sci. U.S.A. 98 (2001) 11016-11023] and that intracellular chloride concentration has been linked to Kv channel kinetics [L.K. Bekar, W. Walz, Intracellular chloride modulates A-type potassium currents in astrocytes, Glia 39 (2002) 207-216; W.B. Thoreson, S.L. Stella, Anion modulation of calcium current voltage dependence and amplitude in salamander rods, Biochim. Biophys. Acta 1464 (2000) 142-150], the objective of the present study was to address how chloride concentration changes affect Kv channel kinetics more closely in an isolated expression system. Initially, no significant chloride concentration-dependent effects on channel steady-state gating kinetics were observed. Only after disruption of the cytoskeleton with cytochalasin-D did we see significant chloride concentration-dependent shifts in gating kinetics. This suggests that the shift in gating kinetics is mediated through effects of intracellular chloride concentration on cytoplasmic domain tertiary conformation as cytoskeletal interaction appears to mask the effect. Furthermore, as cytoskeletal disruption only impacts channel gating kinetics at low physiological intracellular chloride concentrations, these studies highlight the importance of paying close attention to anion concentrations used under experimental conditions.
Floodwater utilisation values of wetland services - a case study in Northeastern China

NASA Astrophysics Data System (ADS)

Lü, S. B.; Xu, S. G.; Feng, F.

2012-02-01

Water plays a significant role in wetlands. Floodwater utilisation in wetlands brings a wide range of wetland services, from goods production and water regulation to animal protection and aesthetics related to water supply in wetlands. In this study, the floodwater utilisation values of wetland services were estimated within the Momoge wetland and Xianghai wetland in western Jilin province of northeastern China. From 2003 to 2008, the floodwater diverted from the Nenjiang and Tao'er River is 381 million m3, which translates into a monetary value of approximately 1.35 billion RMB in 2008 (RMB: Chinese Currency, RMB 6.80 = US 1), and the ratio of economic value, eco-environmental value, and social value is 1:12:2. Besides the monetary value of the water itself, excessive floodwater utilisation may bring losses to wetlands; the threshold floodwater utilisation volumes in wetlands are discussed. Floodwater utilisation can alleviate water shortages in wetlands, and the evaluation of floodwater utilisation in wetland services in monetary terms is a guide for the effective use of the floodwater resources and for the conservation of wetlands.
Reliability analysis for determining performance of barrage based on gates operation

NASA Astrophysics Data System (ADS)

Adiningrum, C.; Hadihardaja, I. K.

2017-06-01

Some rivers located on a flat slope topography such as Cilemahabang river and Ciherang river in Cilemahabang watershed, Bekasi regency, West Java are susceptible to flooding. The inundation mostly happens near a barrage in the middle and downstream of the Cilemahabang watershed, namely the Cilemahabang and Caringin barrages. Barrages or gated weirs are difficult to exploit since the gate must be kept and operated properly under any circumstances. Therefore, a reliability analysis of the gates operation is necessary to determine the performance of the barrage with respect to the number of gates opened and the gates opening heights. The First Order Second Moment (FOSM) method was used to determine the performance by the reliability index (β) and the probability of failure (risk). It was found that for Cilemahabang Barrage, the number of gates opened with load (L) represents the peak discharge derived from various rainfall (P) respectively one gate with opening height (h=1m) for Preal, two gates (h=1m and h=1,5m) for P50, and three gates (each gate with h=2,5m) for P100. For Caringin Barrage, the results are minimum three gates opened (each gate with h=2,5 m) for Preal, five gates opened (each gate with h=2,5m) for P50, and six gates opened (each gate with h=2,5m) for P100. It can be concluded that a greater load (L) needs greater resistance (R) to counterbalance. Resistance can be added by increasing the number of gates opened and the gate opening height. A higher number of gates opened will lead to the decrease of water level in the upstream of barrage and less risk of overflow.
Deliberate self-harm in older adults: a review of the literature from 1995 to 2004.

PubMed

Chan, Jenifer; Draper, Brian; Banerjee, Sube

2007-08-01

The prevention of suicide is a national and international policy priority. Old age is an important predictor of completed suicide. Suicide rates in old age differ markedly from country to country but there is a general trend towards increasing rates with increasing age. In 1996 Draper reviewed critically the evidence on attempted suicide in old age in the 10 years between 1985 and 1994. The review highlighted a need for prospective controlled studies in older people with more representative samples as well as studies examining the interaction of risk factors, precipitants, motivations, psychopathology and response to treatment. The aim of this paper is to update this review and to summarise the advances in our understanding of DSH in later life. We have critically reviewed relevant studies published between 1995 and 2004 to summarise the advances in our understanding of factors associated with deliberate self-harm in later life. The main advances in understanding have been to clarify the effect of personality and cultural factors, service utilisation pre and post attempt, and the (lesser) impact of socio-economic status and physical illness. Methodological weaknesses continue to include inadequate sample sizes performed on highly selected populations, inconsistent age criteria and lack of informant data on studies relating to role of personality. Future studies should include prospective, cross-cultural research with adequate sample sizes and which are population-based. Such approaches might confirm or refute the results generated to date and improve knowledge on factors such as the biological correlates of deliberate self-harm, service utilisation, costs and barriers to health care, and the interaction of these factors. Intervention studies to elucidate the impact of modifying these factors and of specific treatment packages are also needed.
Early primary care physician contact and health service utilisation in a large sample of recently released ex-prisoners in Australia: prospective cohort study

PubMed Central

Arnold-Reed, Diane; Preen, David; Bulsara, Max; Lennox, Nick; Kinner, Stuart A

2015-01-01

Objective To describe the association between ex-prisoner primary care physician contact within 1 month of prison release and health service utilisation in the 6 months following release. Design A cohort from the Passports study with a mean follow-up of 219 (±44) days postrelease. Associations were assessed using a multivariate Andersen-Gill model, controlling for a range of other factors. Setting Face-to-face, baseline interviews were conducted in a sample of prisoners within 6 weeks of expected release from seven prisons in Queensland, Australia, from 2008 to 2010, with telephone follow-up interviews 1, 3 and 6 months postrelease. Participants From an original population-based sample of 1325 sentenced adult (≥18 years) prisoners, 478 participants were excluded due to not being released from prison during follow-up (n=7, 0.5%), loss to follow-up (n=257, 19.4%), or lacking exposure data (n=214, 16.2%). A total of 847 (63.9%) participants were included in the analyses. Exposure Primary care physician contact within 1 month of follow-up as a dichotomous measure. Main outcome measures Adjusted time-to-event hazard rates for hospital, mental health, alcohol and other drug and subsequent primary care physician service utilisations assessed as multiple failure time-interval data. Results Primary care physician contact prevalence within 1 month of follow-up was 46.5%. One-month primary care physician contact was positively associated with hospital (adjusted HR (AHR)=2.07; 95% CI 1.39 to 3.09), mental health (AHR=1.65; 95% CI 1.24 to 2.19), alcohol and other drug (AHR=1.48; 95% CI 1.15 to 1.90) and subsequent primary care physician service utilisation (AHR=1.47; 95% CI 1.26 to 1.72) over 6 months of follow-up. Conclusions Engagement with primary care physician services soon after prison release increases health service utilisation during the critical community transition period for ex-prisoners. Trial registration number Australian New Zealand Clinical Trials Registry (ACTRN12608000232336). PMID:26068513
Determination of prospective displacement-based gate threshold for respiratory-gated radiation delivery from retrospective phase-based gate threshold selected at 4D CT simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vedam, S.; Archambault, L.; Starkschall, G.

2007-11-15

Four-dimensional (4D) computed tomography (CT) imaging has found increasing importance in the localization of tumor and surrounding normal structures throughout the respiratory cycle. Based on such tumor motion information, it is possible to identify the appropriate phase interval for respiratory gated treatment planning and delivery. Such a gating phase interval is determined retrospectively based on tumor motion from internal tumor displacement. However, respiratory-gated treatment is delivered prospectively based on motion determined predominantly from an external monitor. Therefore, the simulation gate threshold determined from the retrospective phase interval selected for gating at 4D CT simulation may not correspond to the deliverymore » gate threshold that is determined from the prospective external monitor displacement at treatment delivery. The purpose of the present work is to establish a relationship between the thresholds for respiratory gating determined at CT simulation and treatment delivery, respectively. One hundred fifty external respiratory motion traces, from 90 patients, with and without audio-visual biofeedback, are analyzed. Two respiratory phase intervals, 40%-60% and 30%-70%, are chosen for respiratory gating from the 4D CT-derived tumor motion trajectory. From residual tumor displacements within each such gating phase interval, a simulation gate threshold is defined based on (a) the average and (b) the maximum respiratory displacement within the phase interval. The duty cycle for prospective gated delivery is estimated from the proportion of external monitor displacement data points within both the selected phase interval and the simulation gate threshold. The delivery gate threshold is then determined iteratively to match the above determined duty cycle. The magnitude of the difference between such gate thresholds determined at simulation and treatment delivery is quantified in each case. Phantom motion tests yielded coincidence of simulation and delivery gate thresholds to within 0.3%. For patient data analysis, differences between simulation and delivery gate thresholds are reported as a fraction of the total respiratory motion range. For the smaller phase interval, the differences between simulation and delivery gate thresholds are 8{+-}11% and 14{+-}21% with and without audio-visual biofeedback, respectively, when the simulation gate threshold is determined based on the mean respiratory displacement within the 40%-60% gating phase interval. For the longer phase interval, corresponding differences are 4{+-}7% and 8{+-}15% with and without audio-visual biofeedback, respectively. Alternatively, when the simulation gate threshold is determined based on the maximum average respiratory displacement within the gating phase interval, greater differences between simulation and delivery gate thresholds are observed. A relationship between retrospective simulation gate threshold and prospective delivery gate threshold for respiratory gating is established and validated for regular and nonregular respiratory motion. Using this relationship, the delivery gate threshold can be reliably estimated at the time of 4D CT simulation, thereby improving the accuracy and efficiency of respiratory-gated radiation delivery.« less
Determination of prospective displacement-based gate threshold for respiratory-gated radiation delivery from retrospective phase-based gate threshold selected at 4D CT simulation.

PubMed

Vedam, S; Archambault, L; Starkschall, G; Mohan, R; Beddar, S

2007-11-01

Four-dimensional (4D) computed tomography (CT) imaging has found increasing importance in the localization of tumor and surrounding normal structures throughout the respiratory cycle. Based on such tumor motion information, it is possible to identify the appropriate phase interval for respiratory gated treatment planning and delivery. Such a gating phase interval is determined retrospectively based on tumor motion from internal tumor displacement. However, respiratory-gated treatment is delivered prospectively based on motion determined predominantly from an external monitor. Therefore, the simulation gate threshold determined from the retrospective phase interval selected for gating at 4D CT simulation may not correspond to the delivery gate threshold that is determined from the prospective external monitor displacement at treatment delivery. The purpose of the present work is to establish a relationship between the thresholds for respiratory gating determined at CT simulation and treatment delivery, respectively. One hundred fifty external respiratory motion traces, from 90 patients, with and without audio-visual biofeedback, are analyzed. Two respiratory phase intervals, 40%-60% and 30%-70%, are chosen for respiratory gating from the 4D CT-derived tumor motion trajectory. From residual tumor displacements within each such gating phase interval, a simulation gate threshold is defined based on (a) the average and (b) the maximum respiratory displacement within the phase interval. The duty cycle for prospective gated delivery is estimated from the proportion of external monitor displacement data points within both the selected phase interval and the simulation gate threshold. The delivery gate threshold is then determined iteratively to match the above determined duty cycle. The magnitude of the difference between such gate thresholds determined at simulation and treatment delivery is quantified in each case. Phantom motion tests yielded coincidence of simulation and delivery gate thresholds to within 0.3%. For patient data analysis, differences between simulation and delivery gate thresholds are reported as a fraction of the total respiratory motion range. For the smaller phase interval, the differences between simulation and delivery gate thresholds are 8 +/- 11% and 14 +/- 21% with and without audio-visual biofeedback, respectively, when the simulation gate threshold is determined based on the mean respiratory displacement within the 40%-60% gating phase interval. For the longer phase interval, corresponding differences are 4 +/- 7% and 8 +/- 15% with and without audiovisual biofeedback, respectively. Alternatively, when the simulation gate threshold is determined based on the maximum average respiratory displacement within the gating phase interval, greater differences between simulation and delivery gate thresholds are observed. A relationship between retrospective simulation gate threshold and prospective delivery gate threshold for respiratory gating is established and validated for regular and nonregular respiratory motion. Using this relationship, the delivery gate threshold can be reliably estimated at the time of 4D CT simulation, thereby improving the accuracy and efficiency of respiratory-gated radiation delivery.
Fluoroscopic evaluation of diaphragmatic motion reduction with a respiratory gated radiotherapy system.

PubMed

Mageras, G S; Yorke, E; Rosenzweig, K; Braban, L; Keatley, E; Ford, E; Leibel, S A; Ling, C C

2001-01-01

We report on initial patient studies to evaluate the performance of a commercial respiratory gating radiotherapy system. The system uses a breathing monitor, consisting of a video camera and passive infrared reflective markers placed on the patient's thorax, to synchronize radiation from a linear accelerator with the patient's breathing cycle. Six patients receiving treatment for lung cancer participated in a study of system characteristics during treatment simulation with fluoroscopy. Breathing synchronized fluoroscopy was performed initially without instruction, followed by fluoroscopy with recorded verbal instruction (i.e., when to inhale and exhale) with the tempo matched to the patient's normal breathing period. Patients tended to inhale more consistently when given instruction, as assessed by an external marker movement. This resulted in smaller variation in expiration and inspiration marker positions relative to total excursion, thereby permitting more precise gating tolerances at those parts of the breathing cycle. Breathing instruction also reduced the fraction of session times having irregular breathing as measured by the system software, thereby potentially increasing the accelerator duty factor and decreasing treatment times. Fluoroscopy studies showed external monitor movement to correlate well with that of the diaphragm in four patients, whereas time delays of up to 0.7 s in diaphragm movement were observed in two patients with impaired lung function. From fluoroscopic observations, average patient diaphragm excursion was reduced from 1.4 cm (range 0.7-2.1 cm) without gating and without breathing instruction, to 0.3 cm (range 0.2-0.5 cm) with instruction and with gating tolerances set for treatment at expiration for 25% of the breathing cycle. Patients expressed no difficulty with following instruction for the duration of a session. We conclude that the external monitor accurately predicts internal respiratory motion in most cases; however, it may be important to check with fluoroscopy for possible time delays in patients with impaired lung function. Furthermore, we observe that verbal instruction can improve breathing regularity, thus improving the performance of gated treatments with this system.
Gating window dependency on scanned carbon-ion beam dose distribution and imaging dose for thoracoabdominal treatment.

PubMed

Mori, Shinichiro; Karube, Masataka; Yasuda, Shigeo; Yamamoto, Naoyoshi; Tsuji, Hiroshi; Kamada, Tadashi

2017-06-01

To explore the trade-off between dose assessment and imaging dose in respiratory gating with radiographic fluoroscopic imaging, we evaluated the relationship between dose assessment and fluoroscopic imaging dose in various gating windows, retrospectively. Four-dimensional (4D) CT images acquired for 10 patients with lung and liver tumours were used for 4D treatment planning for scanned carbon ion beam. Imaging dose from two oblique directions was calculated by the number of images multiplied by the air kerma per image. Necessary beam-on time was calculated from the treatment log file. Accumulated dose distribution was calculated. The gating window was defined as tumour position not respiratory phase and changed from 0-100% duty cycle on 4DCT. These metrics were individually evaluated for every case. For lung cases, sufficient dose conformation was achieved in respective gating windows [D 95 -clinical target volume (CTV) > 99%]. V 20 -lung values for 50%- and 30%-duty cycles were 2.5% and 6.0% of that for 100%-duty cycle. Maximum doses (cord/oesophagus) for 30%-duty cycle decreased 6.8%/7.4% to those for 100%-duty cycle. For liver cases, V 10 -liver values for 50%- and 30%-duty cycles were 9.4% and 12.8% of those for 100%-duty cycle, respectively. Maximum doses (cord/oesophagus) for 50%- and 30%-duty cycles also decreased 17.2%/19.3% and 24.6%/29.8% to those for 100%-duty cycle, respectively. Total imaging doses increased 43.5% and 115.8% for 50%- and 30%-duty cycles to that for the 100%-duty cycle. When normal tissue doses are below the tolerance level, the gating window should be expanded to minimize imaging dose and treatment time. Advances in knowledge: The skin dose from imaging might not be counterbalanced to the OAR dose; however, imaging dose is a particularly important factor.
Advanced optical simulation of scintillation detectors in GATE V8.0: first implementation of a reflectance model based on measured data

NASA Astrophysics Data System (ADS)

Stockhoff, Mariele; Jan, Sebastien; Dubois, Albertine; Cherry, Simon R.; Roncali, Emilie

2017-06-01

Typical PET detectors are composed of a scintillator coupled to a photodetector that detects scintillation photons produced when high energy gamma photons interact with the crystal. A critical performance factor is the collection efficiency of these scintillation photons, which can be optimized through simulation. Accurate modelling of photon interactions with crystal surfaces is essential in optical simulations, but the existing UNIFIED model in GATE is often inaccurate, especially for rough surfaces. Previously a new approach for modelling surface reflections based on measured surfaces was validated using custom Monte Carlo code. In this work, the LUT Davis model is implemented and validated in GATE and GEANT4, and is made accessible for all users in the nuclear imaging research community. Look-up-tables (LUTs) from various crystal surfaces are calculated based on measured surfaces obtained by atomic force microscopy. The LUTs include photon reflection probabilities and directions depending on incidence angle. We provide LUTs for rough and polished surfaces with different reflectors and coupling media. Validation parameters include light output measured at different depths of interaction in the crystal and photon track lengths, as both parameters are strongly dependent on reflector characteristics and distinguish between models. Results from the GATE/GEANT4 beta version are compared to those from our custom code and experimental data, as well as the UNIFIED model. GATE simulations with the LUT Davis model show average variations in light output of <2% from the custom code and excellent agreement for track lengths with R 2 > 0.99. Experimental data agree within 9% for relative light output. The new model also simplifies surface definition, as no complex input parameters are needed. The LUT Davis model makes optical simulations for nuclear imaging detectors much more precise, especially for studies with rough crystal surfaces. It will be available in GATE V8.0.
A Typology of Chemistry Classroom Environments: Exploring the Relationships between 10th Grade Students' Perceptions, Attitudes and Gender

ERIC Educational Resources Information Center

Giallousi, M.; Gialamas, V.; Pavlatou, E. A.

2013-01-01

The present study was the first in Greece in which educational effectiveness theory constituted a knowledge base for investigating the impact of chemistry classroom environment in 10 Grade students' enjoyment of class. An interpretive heuristic schema was developed and utilised in order to incorporate two factors of teacher behaviour at classroom…
Rights-Based Education and Conflict: A Cross-National Study of Rights Discourse in Textbooks

ERIC Educational Resources Information Center

Russell, Susan Garnett; Tiplic, Dijana

2014-01-01

This paper investigates the extent to which rights-based education is utilised in textbooks from conflict-affected countries. Drawing on a unique dataset of 528 secondary social science textbooks from 71 countries from 1966 to 2008, we analyse factors that predict a rights discourse in texts. We find that textbooks from conflict-affected nations…
Historical Reflections on the Ascendancy of ADHD in North America, c. 1980 - c. 2005

ERIC Educational Resources Information Center

Neufeld, Paul; Foy, Michael

2006-01-01

An ecological niche framework (Hacking, 1998) is utilised to examine the growth of ADHD in North America. The analysis suggests ADHD flourishes, at least in part, due to a complex and historically situated interaction of factors that created a niche within which a particular kind of explanation and treatment for the troubling behaviours of…
Demographic Variables as Factors Influencing Accessibility and Utilisation of Library Software by Undergraduates in Two Private Universities in Nigeria

ERIC Educational Resources Information Center

Tolulope, Akano

2017-01-01

Libraries before the 21st century carried out daily routine library task such as cataloguing and classification, acquisition, reference services etc using manual procedures only but the advent of Information Technology as transformed these routine task that libraries can now automate their activities by deploying the use of library software in…
Experiencing the "Wild Woods": The Impact of Pedagogy on Children's Experience of a Natural Environment

ERIC Educational Resources Information Center

Mawson, William Brent

2014-01-01

Outdoor play environments offer a wide range of potential affordances to both teachers and children. Teachers' pedagogy is a strong determining factor in children's ability to utilise the affordances of a particular environment. This article describes the way in which a group of teachers and children in a New Zealand education and care centre…
Teaching Practice of Physical Education Teachers for Students with Special Needs: An Application of the Theory of Planned Behaviour

ERIC Educational Resources Information Center

Wang, Lijuan; Wang, Min; Wen, Hongwei

2015-01-01

This study examines the teaching behavior of physical education (PE) teachers in teaching students with special needs and the factors that determine their teaching behaviour. An extended theory of planned behaviour (TPB) was utilised as the theoretical framework. Three secondary and two high school PE teachers participated in the study. Data…
Analytical Modelling of the Spread of Disease in Confined and Crowded Spaces

NASA Astrophysics Data System (ADS)

Goscé, Lara; Barton, David A. W.; Johansson, Anders

2014-05-01

Since 1927 and until recently, most models describing the spread of disease have been of compartmental type, based on the assumption that populations are homogeneous and well-mixed. Recent models have utilised agent-based models and complex networks to explicitly study heterogeneous interaction patterns, but this leads to an increasing computational complexity. Compartmental models are appealing because of their simplicity, but their parameters, especially the transmission rate, are complex and depend on a number of factors, which makes it hard to predict how a change of a single environmental, demographic, or epidemiological factor will affect the population. Therefore, in this contribution we propose a middle ground, utilising crowd-behaviour research to improve compartmental models in crowded situations. We show how both the rate of infection as well as the walking speed depend on the local crowd density around an infected individual. The combined effect is that the rate of infection at a population scale has an analytically tractable non-linear dependency on crowd density. We model the spread of a hypothetical disease in a corridor and compare our new model with a typical compartmental model, which highlights the regime in which current models may not produce credible results.
The Extent of Consumer Product Involvement in Paediatric Injuries

PubMed Central

Catchpoole, Jesani; Walker, Sue; Vallmuur, Kirsten

2016-01-01

A challenge in utilising health sector injury data for Product Safety purposes is that clinically coded data have limited ability to inform regulators about product involvement in injury events, given data entry is bound by a predefined set of codes. Text narratives collected in emergency departments can potentially address this limitation by providing relevant product information with additional accompanying context. This study aims to identify and quantify consumer product involvement in paediatric injuries recorded in emergency department-based injury surveillance data. A total of 7743 paediatric injuries were randomly selected from Queensland Injury Surveillance Unit database and associated text narratives were manually reviewed to determine product involvement in the injury event. A Product Involvement Factor classification system was used to categorise these injury cases. Overall, 44% of all reviewed cases were associated with consumer products, with proximity factor (25%) being identified as the most common involvement of a product in an injury event. Only 6% were established as being directly due to the product. The study highlights the importance of utilising injury data to inform product safety initiatives where text narratives can be used to identify the type and involvement of products in injury cases. PMID:27399744

The Extent of Consumer Product Involvement in Paediatric Injuries.

PubMed

Catchpoole, Jesani; Walker, Sue; Vallmuur, Kirsten

2016-07-07

A challenge in utilising health sector injury data for Product Safety purposes is that clinically coded data have limited ability to inform regulators about product involvement in injury events, given data entry is bound by a predefined set of codes. Text narratives collected in emergency departments can potentially address this limitation by providing relevant product information with additional accompanying context. This study aims to identify and quantify consumer product involvement in paediatric injuries recorded in emergency department-based injury surveillance data. A total of 7743 paediatric injuries were randomly selected from Queensland Injury Surveillance Unit database and associated text narratives were manually reviewed to determine product involvement in the injury event. A Product Involvement Factor classification system was used to categorise these injury cases. Overall, 44% of all reviewed cases were associated with consumer products, with proximity factor (25%) being identified as the most common involvement of a product in an injury event. Only 6% were established as being directly due to the product. The study highlights the importance of utilising injury data to inform product safety initiatives where text narratives can be used to identify the type and involvement of products in injury cases.
Utilisation of the c-fos immunohistochemical method: a 2004 quantitative study.

PubMed

Robert, C; Arreto, C D; Gaudy, J F; Wilson, C S

2007-10-01

The aim of this study was to provide a quantitative view of the utilisation of the c-fos immunohistochemical method. Articles including the term "c-fos" in their title, abstract or keywords and published in 2004 were retrieved from the Current Content/Life Sciences or Current Content/Clinical Medicine collection of the SCI database. The 933 article-type documents retained were distributed in almost all the sub-disciplines of the Life Sciences and Clinical Medicine, but were principally published in the field of neuroscience. They were authored by researchers from 44 countries - the most prolific were the USA (435 articles), Japan (135) and the UK (55). The 933 articles were published in 283 different journals; all but one of the top-20 most prolific journals are in the Life Sciences discipline, and their Impact Factors ranged from 2.0 to 7.9. A comparison of the USA and the European Union scientific profiles is also made.
Elucidation of the biosynthesis of the methane catalyst coenzyme F430

PubMed Central

Moore, Simon J.; Sowa, Sven T.; Schuchardt, Christopher; Deery, Evelyne; Lawrence, Andrew D.; Ramos, José Vazquez; Billig, Susan; Birkemeyer, Claudia; Chivers, Peter T.; Howard, Mark J.; Rigby, Stephen E. J.; Layer, Gunhild; Warren, Martin J.

2017-01-01

Summary Methane biogenesis in methanogens is mediated by methyl-coenzyme M reductase, an enzyme that is also responsible for the utilisation of methane through anaerobic methane oxidation. The enzyme employs an ancillary factor called coenzyme F430, a nickel-containing modified tetrapyrrole that promotes catalysis through a novel methyl radical/Ni(II)-thiolate intermediate. However, the biosynthesis of coenzyme F430 from the common primogenitor uroporphyrinoge III, incorporating 11 steric centres into the macrocycle, has remained poorly understood although the pathway must involve chelation, amidation, macrocyclic ring reduction, lactamisation and carbocyclic ring formation. We have now identified the proteins that catalyse coenzyme F430 biosynthesis from sirohydrochlorin, termed CfbA-E, and shown their activity. The research completes our understanding of how nature is able to construct its repertoire of tetrapyrrole-based life pigments, permitting the development of recombinant systems to utilise these metalloprosthetic groups more widely. PMID:28225763
Sámi youth health, the role of climate change, and unique health-seeking behaviour.

PubMed

Kowalczewski, Emilie; Klein, Joern

2018-12-01

The goal of this cross-sectional qualitative study was to assess the impact of climate change on Sámi youth health, health care access, and health-seeking behaviour. Indigenous research methodology served as the basis of the investigation which utilised focus groups of youths and one-on-one interviews of adult community leaders using a semi-structured, open-ended questions. The results of the focus groups and interviews were then analysed to identify trends. We found that Sámi youth mostly associate the implications of climate change to their culture andcultural practices rather than the historical influence the environment had on Sámi health. They also take part in unique health-seeking behaviour by utilising both traditional and Western medicine simultaneously but without interaction due to social and structural factors. Our findings suggest that the health of Sámi teens is not tied to the environment directly, but through cultural activities.
The impact of communication on human behaviour in times of crisis.

PubMed

MacLeod, Andrew

Decision makers have constantly sought to find the most appropriate ways to use communication to influence behaviour during times of crises to assist in their recovery. This paper will investigate why policy makers wish to utilise effective crisis communications and explore the importance of crisis communication on influencing human behaviour in a time of crisis as well as the influence that the medium of communication can have. It will be noted that the medium of the message is important to ensure that the correct audience has been reached. This paper will suggest that, for decision makers to maximise the impact of crisis communications during a crisis, they must utilise rhetoric and cognitive response theory. It will also be suggested that the most importance factor in influencing behaviour in a time of crisis is that communications are provided from a credible source and are empathic in nature.
Microbial diversity arising from thermodynamic constraints

PubMed Central

Großkopf, Tobias; Soyer, Orkun S

2016-01-01

The microbial world displays an immense taxonomic diversity. This diversity is manifested also in a multitude of metabolic pathways that can utilise different substrates and produce different products. Here, we propose that these observations directly link to thermodynamic constraints that inherently arise from the metabolic basis of microbial growth. We show that thermodynamic constraints can enable coexistence of microbes that utilise the same substrate but produce different end products. We find that this thermodynamics-driven emergence of diversity is most relevant for metabolic conversions with low free energy as seen for example under anaerobic conditions, where population dynamics is governed by thermodynamic effects rather than kinetic factors such as substrate uptake rates. These findings provide a general understanding of the microbial diversity based on the first principles of thermodynamics. As such they provide a thermodynamics-based framework for explaining the observed microbial diversity in different natural and synthetic environments. PMID:27035705
Social sciences research in neglected tropical diseases 3: Investment in social science research in neglected diseases of poverty: a case study of Bill and Melinda Gates Foundation.

PubMed

Pokhrel, Subhash; Reidpath, Daniel; Allotey, Pascale

2011-01-06

The level of funding provides a good proxy for the level of commitment or prioritisation given to a particular issue. While the need for research relevant to social, economic, cultural and behavioural aspects of neglected tropical diseases (NTD) control has been acknowledged, there is limited data on the level of funding that supports NTD social science research. A case study was carried out in which the spending of a major independent funder, the Bill and Melinda Gates Foundation (BMGF) - was analysed. A total of 67 projects funded between October 1998 and November 2008 were identified from the BMGF database. With the help of keywords within the titles of 67 grantees, they were categorised as social science or non-social science research based on available definition of social science. A descriptive analysis was conducted. Of 67 projects analysed, 26 projects (39%) were social science related while 41 projects (61%) were basic science or other translational research including drug development. A total of US$ 697 million was spent to fund the projects, of which 35% ((US$ 241 million) went to social science research. Although the level of funding for social science research has generally been lower than that for non-social science research over 10 year period, social science research attracted more funding in 2004 and 2008. The evidence presented in this case study indicates that funding on NTD social science research compared to basic and translational research is not as low as it is perceived to be. However, as there is the acute need for improved delivery and utilisation of current NTD drugs/technologies, informed by research from social science approaches, funding priorities need to reflect the need to invest significantly more in NTD social science research.
Social sciences research in neglected tropical diseases 3: Investment in social science research in neglected diseases of poverty: a case study of Bill and Melinda Gates Foundation

PubMed Central

2011-01-01

Background The level of funding provides a good proxy for the level of commitment or prioritisation given to a particular issue. While the need for research relevant to social, economic, cultural and behavioural aspects of neglected tropical diseases (NTD) control has been acknowledged, there is limited data on the level of funding that supports NTD social science research. Method A case study was carried out in which the spending of a major independent funder, the Bill and Melinda Gates Foundation (BMGF) - was analysed. A total of 67 projects funded between October 1998 and November 2008 were identified from the BMGF database. With the help of keywords within the titles of 67 grantees, they were categorised as social science or non-social science research based on available definition of social science. A descriptive analysis was conducted. Results Of 67 projects analysed, 26 projects (39%) were social science related while 41 projects (61%) were basic science or other translational research including drug development. A total of US$ 697 million was spent to fund the projects, of which 35% ((US$ 241 million) went to social science research. Although the level of funding for social science research has generally been lower than that for non-social science research over 10 year period, social science research attracted more funding in 2004 and 2008. Conclusion The evidence presented in this case study indicates that funding on NTD social science research compared to basic and translational research is not as low as it is perceived to be. However, as there is the acute need for improved delivery and utilisation of current NTD drugs/technologies, informed by research from social science approaches, funding priorities need to reflect the need to invest significantly more in NTD social science research. PMID:21210999
Using signal detection theory to understand grade crossing warning time and motorist stopping behavior.

DOT National Transportation Integrated Search

2015-02-01

Motorist error or poor judgment is a significant causal factor in highway-rail grade crossing collisions. Crashes at grade crossings : equipped with warning devices often involve motorists who drive around gates or across railroad tracks while flashi...
ZnO thin film transistor immunosensor with high sensitivity and selectivity

NASA Astrophysics Data System (ADS)

Reyes, Pavel Ivanoff; Ku, Chieh-Jen; Duan, Ziqing; Lu, Yicheng; Solanki, Aniruddh; Lee, Ki-Bum

2011-04-01

A zinc oxide thin film transistor-based immunosensor (ZnO-bioTFT) is presented. The back-gate TFT has an on-off ratio of 108 and a threshold voltage of 4.25 V. The ZnO channel surface is biofunctionalized with primary monoclonal antibodies that selectively bind with epidermal growth factor receptor (EGFR). Detection of the antibody-antigen reaction is achieved through channel carrier modulation via pseudo double-gating field effect caused by the biochemical reaction. The sensitivity of 10 fM detection of pure EGFR proteins is achieved. The ZnO-bioTFT immunosensor also enables selectively detecting 10 fM of EGFR in a 5 mg/ml goat serum solution containing various other proteins.
Circuit quantum electrodynamics architecture for gate-defined quantum dots in silicon

NASA Astrophysics Data System (ADS)

Mi, X.; Cady, J. V.; Zajac, D. M.; Stehlik, J.; Edge, L. F.; Petta, J. R.

2017-01-01

We demonstrate a hybrid device architecture where the charge states in a double quantum dot (DQD) formed in a Si/SiGe heterostructure are read out using an on-chip superconducting microwave cavity. A quality factor Q = 5400 is achieved by selectively etching away regions of the quantum well and by reducing photon losses through low-pass filtering of the gate bias lines. Homodyne measurements of the cavity transmission reveal DQD charge stability diagrams and a charge-cavity coupling rate g c / 2 π = 23 MHz. These measurements indicate that electrons trapped in a Si DQD can be effectively coupled to microwave photons, potentially enabling coherent electron-photon interactions in silicon.
Investigation of Ultraviolet Light Curable Polysilsesquioxane Gate Dielectric Layers for Pentacene Thin Film Transistors.

PubMed

Shibao, Hideto; Nakahara, Yoshio; Uno, Kazuyuki; Tanaka, Ichiro

2016-04-01

Polysilsesquioxane (PSQ) comprising 3-methacryloxypropyl groups was investigated as an ultraviolet (UV)-light curable gate dielectric-material for pentacene thin film transistors (TFTs). The surface of UV-light cured PSQ films was smoother than that of thermally cured ones, and the pentacene layers deposited on the UV-Iight cured PSQ films consisted of larger grains. However, carrier mobility of the TFTs using the UV-light cured PSQ films was lower than that of the TFTs using the thermally cured ones. It was shown that the cross-linker molecules, which were only added to the UV-light cured PSQ films, worked as a major mobility-limiting factor for the TFTs.
Gate Modulation of Graphene-ZnO Nanowire Schottky Diode.

PubMed

Liu, Ren; You, Xu-Chen; Fu, Xue-Wen; Lin, Fang; Meng, Jie; Yu, Da-Peng; Liao, Zhi-Min

2015-05-06

Graphene-semiconductor interface is important for the applications in electronic and optoelectronic devices. Here we report the modulation of the electric transport properties of graphene/ZnO nanowire Schottky diode by gate voltage (Vg). The ideality factor of the graphene/ZnO nanowire Schottky diode is ~1.7, and the Schottky barrier height is ~0.28 eV without external Vg. The Schottky barrier height is sensitive to Vg due to the variation of Fermi level of graphene. The barrier height increases quickly with sweeping Vg towards the negative value, while decreases slowly towards the positive Vg. Our results are helpful to understand the fundamental mechanism of the electric transport in graphene-semiconductor Schottky diode.
Respiratory gating and multifield technique radiotherapy for esophageal cancer.

PubMed

Ohta, Atsushi; Kaidu, Motoki; Tanabe, Satoshi; Utsunomiya, Satoru; Sasamoto, Ryuta; Maruyama, Katsuya; Tanaka, Kensuke; Saito, Hirotake; Nakano, Toshimichi; Shioi, Miki; Takahashi, Haruna; Kushima, Naotaka; Abe, Eisuke; Aoyama, Hidefumi

2017-03-01

To investigate the effects of a respiratory gating and multifield technique on the dose-volume histogram (DVH) in radiotherapy for esophageal cancer. Twenty patients who underwent four-dimensional computed tomography for esophageal cancer were included. We retrospectively created the four treatment plans for each patient, with or without the respiratory gating and multifield technique: No gating-2-field, No gating-4-field, Gating-2-field, and Gating-4-field plans. We compared the DVH parameters of the lung and heart in the No gating-2-field plan with the other three plans. In the comparison of the parameters in the No gating-2-field plan, there are significant differences in the Lung V 5Gy , V 20Gy , mean dose with all three plans and the Heart V 25Gy -V 40Gy with Gating-2-field plan, V 35Gy , V 40Gy , mean dose with No Gating-4-field plan and V 30Gy -V 40Gy , and mean dose with Gating-4-field plan. The lung parameters were smaller in the Gating-2-field plan and larger in the No gating-4-field and Gating-4-field plans. The heart parameters were all larger in the No gating-2-field plan. The lung parameters were reduced by the respiratory gating technique and increased by the multifield technique. The heart parameters were reduced by both techniques. It is important to select the optimal technique according to the risk of complications.
SU-E-T-401: Feasibility Study of Using ABC to Gate Lung SBRT Treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cao, D; Xie, X; Shepard, D

2014-06-01

Purpose: The current SBRT treatment techniques include free breathing (FB) SBRT and gated FB SBRT. Gated FB SBRT has smaller target and less lung toxicity with longer treatment time. The recent development of direct connectivity between the ABC and linac allowing for automated beam gating. In this study, we have examined the feasibility of using ABC system to gate the lung SBRT treatment. Methods: A CIRS lung phantom with a 3cm sphere-insert and a moving chest plate was used in this study. Sinusoidal motion was used for the FB pattern. An ABC signal was imported to simulate breath holds. 4D-CTmore » was taken in FB mode and average-intensity-projection (AIP) was used to create FB and 50% gated FB SBRT planning CT. A manually gated 3D CT scan was acquired for ABC gated SBRT planning.An SBRT plan was created for each treatment option. A surface-mapping system was used for 50% gating and ABC system was used for ABC gating. A manually gated CBCT scan was also performed to verify setup. Results: Among three options, the ABC gated plan has the smallest PTV of 35.94cc, which is 35% smaller comparing to that of the FB plan. Consequently, the V20 of the left lung reduced by 15% and 23% comparing to the 50% gated FB and FB plans, respectively. The FB plan took 4.7 minutes to deliver, while the 50% gated FB plan took 18.5 minutes. The ABC gated plan delivery took only 10.6 minutes. A stationary target with 3cm diameter was also obtained from the manually gated CBCT scan. Conclusion: A strategy for ABC gated lung SBRT was developed. ABC gating can significantly reduce the lung toxicity while maintaining the target coverage. Comparing to the 50% gated FB SBRT, ABC gated treatment can also provide less lung toxicity as well as improved delivery efficiency. This research is funded by Elekta.« less
Partnering for Learnware: Critical Success Factors in the Use of Learnware by Human Resources Sector Councils and Industry Associations in Canada = Partenariats pour les technologies d'apprentissage: Facteurs critiques de succes dans l'utilisation des technologies d'apprentissage par les conseils sectoriels des ressources humaines et les associations industrielles au Canada.

ERIC Educational Resources Information Center

Stahmer, Anna; Green, Lyndsay

The use of learnware by human resources sector councils and industry associations in Canada was examined to identify critical success factors in the use of technology-based training. Eight case studies--four involving sector councils and four involving industry associations that either have national mandates or distribute their products across…
Price and utilisation differences for statins between four countries.

PubMed

Thai, Loc Phuoc; Vitry, Agnes Isabelle; Moss, John Robert

2018-02-01

Australia, England, France and New Zealand use different policies to regulate their medicines market, which can impact on utilisation and price. To compare the prices and utilisation of statins in Australia, England, France and New Zealand from 2011 to 2013. Utilisation of statins in the four countries was compared using Defined Daily Doses (DDD) per 1000 inhabitants per year. Pairwise Laspeyres and Paasche index comparisons were conducted comparing the price and utilisation of statins. The results showed that the price of statins in New Zealand was the cheapest. The price of statins in Australia was most expensive in 2011 and 2012 but France was more expensive in 2013. There were large differences between the Laspeyres index and Paasche index when comparing the price and utilisation of England with Australia and France. The policies that regulate the New Zealand and England medicines markets were more effective in reducing the price of expensive statins. The relative utilisation of cheaper statins was greatest in England and had a large effect on the differences between the two index results. The pricing policies in Australia have been only partly effective in reducing the price of statins compared to other countries.
Technical Note: High temporal resolution characterization of gating response time.

PubMed

Wiersma, Rodney D; McCabe, Bradley P; Belcher, Andrew H; Jensen, Patrick J; Smith, Brett; Aydogan, Bulent

2016-06-01

Low temporal latency between a gating ON/OFF signal and the LINAC beam ON/OFF during respiratory gating is critical for patient safety. Here the authors describe a novel method to precisely measure gating lag times at high temporal resolutions. A respiratory gating simulator with an oscillating platform was modified to include a linear potentiometer for position measurement. A photon diode was placed at linear accelerator isocenter for beam output measurement. The output signals of the potentiometer and diode were recorded simultaneously at 2500 Hz with an analog to digital converter for four different commercial respiratory gating systems. The ON and OFF of the beam signal were located and compared to the expected gating window for both phase and position based gating and the temporal lag times extracted. For phase based gating, a real-time position management (RPM) infrared marker tracking system with a single camera and a RPM system with a stereoscopic camera were measured to have mean gate ON/OFF lag times of 98/90 and 86/44 ms, respectively. For position based gating, an AlignRT 3D surface system and a Calypso magnetic fiducial tracking system were measured to have mean gate ON/OFF lag times of 356/529 and 209/60 ms, respectively. Temporal resolution of the method was high enough to allow characterization of individual gate cycles and was primary limited by the sampling speed of the data recording device. Significant variation of mean gate ON/OFF lag time was found between different gating systems. For certain gating devices, individual gating cycle lag times can vary significantly.
Technical Note: High temporal resolution characterization of gating response time

PubMed Central

Wiersma, Rodney D.; McCabe, Bradley P.; Belcher, Andrew H.; Jensen, Patrick J.; Smith, Brett; Aydogan, Bulent

2016-01-01

Purpose: Low temporal latency between a gating ON/OFF signal and the LINAC beam ON/OFF during respiratory gating is critical for patient safety. Here the authors describe a novel method to precisely measure gating lag times at high temporal resolutions. Methods: A respiratory gating simulator with an oscillating platform was modified to include a linear potentiometer for position measurement. A photon diode was placed at linear accelerator isocenter for beam output measurement. The output signals of the potentiometer and diode were recorded simultaneously at 2500 Hz with an analog to digital converter for four different commercial respiratory gating systems. The ON and OFF of the beam signal were located and compared to the expected gating window for both phase and position based gating and the temporal lag times extracted. Results: For phase based gating, a real-time position management (RPM) infrared marker tracking system with a single camera and a RPM system with a stereoscopic camera were measured to have mean gate ON/OFF lag times of 98/90 and 86/44 ms, respectively. For position based gating, an AlignRT 3D surface system and a Calypso magnetic fiducial tracking system were measured to have mean gate ON/OFF lag times of 356/529 and 209/60 ms, respectively. Conclusions: Temporal resolution of the method was high enough to allow characterization of individual gate cycles and was primary limited by the sampling speed of the data recording device. Significant variation of mean gate ON/OFF lag time was found between different gating systems. For certain gating devices, individual gating cycle lag times can vary significantly. PMID:27277028
A pH sensor with a double-gate silicon nanowire field-effect transistor

NASA Astrophysics Data System (ADS)

Ahn, Jae-Hyuk; Kim, Jee-Yeon; Seol, Myeong-Lok; Baek, David J.; Guo, Zheng; Kim, Chang-Hoon; Choi, Sung-Jin; Choi, Yang-Kyu

2013-02-01

A pH sensor composed of a double-gate silicon nanowire field-effect transistor (DG Si-NW FET) is demonstrated. The proposed DG Si-NW FET allows the independent addressing of the gate voltage and hence improves the sensing capability through an application of asymmetric gate voltage between the two gates. One gate is a driving gate which controls the current flow, and the other is a supporting gate which amplifies the shift of the threshold voltage, which is a sensing metric, and which arises from changes in the pH. The pH signal is also amplified through modulation of the gate oxide thickness.

Microdose Induced Data Loss on Floating Gate Memories

NASA Technical Reports Server (NTRS)

Guertin, Steven M.; Nguyen, Duc M.; Patterson, Jeffrey D.

2006-01-01

Heavy ion irradiation of flash memories shows loss of stored data. The fluence dependence is indicative of microdose effects. Other qualitative factors identifying the effect as microdose are discussed. The data is presented, and compared to statistical results of a microdose target-based model.
Health care utilisation under the 30-Baht Scheme among the urban poor in Mitrapap slum, Khon Kaen, Thailand: a cross-sectional study

PubMed Central

Coronini-Cronberg, Sophie; Laohasiriwong, Wongsa; Gericke, Christian A

2007-01-01

Background In 2001, the Government of Thailand introduced a universal coverage scheme with the aim of ensuring equitable health care access for even the poorest citizens. For a flat user fee of 30 Baht per consultation, or for free for those falling into exemption categories, every scheme participant may access registered health services. The exemption categories include children under 12 years of age, senior citizens aged 60 years and over, the very poor, and volunteer health workers. The functioning of these exemption mechanisms and the effect of the scheme on health service utilisation among the poor is controversial. Methods This cross-sectional study investigated the prevalence of 30-Baht Scheme registration and subsequent self-reported health service utilisation among an urban poor population in the Teparuk community within the Mitrapap slum in Khon Kaen city, northeastern Thailand. Furthermore, the effectiveness of the exemption mechanisms in reaching the very poor and the elderly was examined. Factors for users' choice of health facilities were identified. Results Overall, the proportion of the Teparuk community enrolled with the 30-Baht Scheme was high at 86%, with over one quarter of these exempted from paying the consultation fee. User fee exemption was significantly more frequent among households with an above-poverty-line income (64.7%) compared to those below the poverty line (35.3%), χ2 (df) = 5.251 (1); p-value = 0.018. In addition, one third of respondents over 60 years of age were found to be still paying user fees. Self-reported use of registered medical facilities in case of illness was stated to be predominantly due to the service being available through the scheme, with service quality not a chief consideration. Overall consumer satisfaction was high, especially among those not required to pay the 30 Baht user fee. Conclusion Whilst the 30-Baht Scheme seems to cover most of the poor population of Mitrapap slum in Khon Kaen, the user fee exemption mechanism only works partially with regard to reaching the poorest and exempting senior citizens. Service utilisation and satisfaction are highest amongst those who are fee-exempt. Service quality was not an important factor influencing choice of health facility. Ways should be sought to improve the effectiveness of the current exemption mechanisms. PMID:17883874
High-Fidelity Single-Shot Toffoli Gate via Quantum Control.

PubMed

Zahedinejad, Ehsan; Ghosh, Joydip; Sanders, Barry C

2015-05-22

A single-shot Toffoli, or controlled-controlled-not, gate is desirable for classical and quantum information processing. The Toffoli gate alone is universal for reversible computing and, accompanied by the Hadamard gate, forms a universal gate set for quantum computing. The Toffoli gate is also a key ingredient for (nontopological) quantum error correction. Currently Toffoli gates are achieved by decomposing into sequentially implemented single- and two-qubit gates, which require much longer times and yields lower overall fidelities compared to a single-shot implementation. We develop a quantum-control procedure to construct a single-shot Toffoli gate for three nearest-neighbor-coupled superconducting transmon systems such that the fidelity is 99.9% and is as fast as an entangling two-qubit gate under the same realistic conditions. The gate is achieved by a nongreedy quantum control procedure using our enhanced version of the differential evolution algorithm.
The effect of systematic set-up deviations on the absorbed dose distribution for left-sided breast cancer treated with respiratory gating

NASA Astrophysics Data System (ADS)

Edvardsson, A.; Ceberg, S.

2013-06-01

The aim of this study was 1) to investigate interfraction set-up uncertainties for patients treated with respiratory gating for left-sided breast cancer, 2) to investigate the effect of the inter-fraction set-up on the absorbed dose-distribution for the target and organs at risk (OARs) and 3) optimize the set-up correction strategy. By acquiring multiple set-up images the systematic set-up deviation was evaluated. The effect of the systematic set-up deviation on the absorbed dose distribution was evaluated by 1) simulation in the treatment planning system and 2) measurements with a biplanar diode array. The set-up deviations could be decreased using a no action level correction strategy. Not using the clinically implemented adaptive maximum likelihood factor for the gating patients resulted in better set-up. When the uncorrected set-up deviations were simulated the average mean absorbed dose was increased from 1.38 to 2.21 Gy for the heart, 4.17 to 8.86 Gy to the left anterior descending coronary artery and 5.80 to 7.64 Gy to the left lung. Respiratory gating can induce systematic set-up deviations which would result in increased mean absorbed dose to the OARs if not corrected for and should therefore be corrected for by an appropriate correction strategy.
A two-dimensional (2D) analytical subthreshold swing and transconductance model of underlap dual-material double-gate (DMDG) MOSFET for analog/RF applications

NASA Astrophysics Data System (ADS)

Narendar, Vadthiya; Rai, Saurabh; Tiwari, Siddharth; Mishra, R. A.

2016-12-01

The double-gate (DG) metal-oxide-semiconductor field effect transistors (MOSFETs) are the choice of technology in sub -100 nm regime of leading microelectronics industry. To enhance the analog and RF performance of DG MOSFET, an underlap dual-material (DM) DG MOSFET device structure has been considered because, it has the advantages of both underlap as well as that of dual-material gate (DMG). A 2D analytical surface potential, subthreshold current, subthreshold swing as well as transconductance modelling of underlap DMDG MOSFET has been done by solving the Poisson's equation. It has also been found that, numerically simulated data approves the analytically modelled data with commendable accuracy. As underlap length (Lun) increases, a substantial reduction of subthreshold current due to enhanced gate control over channel regime is observed. DMG structure facilitates to improve the average velocity of carriers which leads to superior drive current of the device. The underlap DMDG MOSFET device structure demonstrates an ameliorated subthreshold characteristic. The analog figure of merits (FOMs) such as transconductance (gm), transconductance generation factor (TGF), output conductance (gd), early voltage (VEA), intrinsic gain (AV) and RF FOMs namely cut-off frequency (fT), gain frequency product (GFP), transconductance frequency product (TFP) and gain transconductance frequency product (GTFP) have been evaluated. The aforesaid analysis revels that, the device is best suited for communication related Analog/RF applications.
Applying fault tree analysis to the prevention of wrong-site surgery.

PubMed

Abecassis, Zachary A; McElroy, Lisa M; Patel, Ronak M; Khorzad, Rebeca; Carroll, Charles; Mehrotra, Sanjay

2015-01-01

Wrong-site surgery (WSS) is a rare event that occurs to hundreds of patients each year. Despite national implementation of the Universal Protocol over the past decade, development of effective interventions remains a challenge. We performed a systematic review of the literature reporting root causes of WSS and used the results to perform a fault tree analysis to assess the reliability of the system in preventing WSS and identifying high-priority targets for interventions aimed at reducing WSS. Process components where a single error could result in WSS were labeled with OR gates; process aspects reinforced by verification were labeled with AND gates. The overall redundancy of the system was evaluated based on prevalence of AND gates and OR gates. In total, 37 studies described risk factors for WSS. The fault tree contains 35 faults, most of which fall into five main categories. Despite the Universal Protocol mandating patient verification, surgical site signing, and a brief time-out, a large proportion of the process relies on human transcription and verification. Fault tree analysis provides a standardized perspective of errors or faults within the system of surgical scheduling and site confirmation. It can be adapted by institutions or specialties to lead to more targeted interventions to increase redundancy and reliability within the preoperative process. Copyright © 2015 Elsevier Inc. All rights reserved.
Shubnikov-de Haas oscillations of high mobility holes in monolayer and bilayer WSe2: spin-valley locking, effective mass, and inter-layer coupling

NASA Astrophysics Data System (ADS)

Fallahazad, Babak; Movva, Hema Chandra Prakash; Kim, Kyounghwan; Larentis, Stefano; Taniguchi, Takashi; Watanabe, Kenji; Banerjee, Sanjay K.; Tutuc, Emanuel

We study the magnetotransport properties of high mobility holes in monolayer and bilayer WSe2, measured in dual-gated samples with top and bottom hexagonal boron-nitride dielectrics, and using platinum bottom contacts. Thanks to the Pt high work-function combined with the a high hole density induced electrostatically by an applied top gate bias, the contacts remain ohmic down to low (1.5 K) temperatures. The samples display well defined Shubnikov-de Haas (SdH) oscillations, and quantum Hall states (QHS) in high magnetic fields. In both mono and bilayer WSe2, the SdH oscillations and the QHSs occur predominantly at even filling factors, evincing a two-fold Landau level degeneracy consistent with spin-valley locking. The Fourier transform analysis of the SdH oscillations in dual-gated bilayer WSe2 reveal the presence of two subbands, each localized in the top or the bottom layer, as well as negative compressibility. From the temperature dependence of the SdH oscillation amplitude we determine a hole effective mass of 0.45me for both mono and bilayer WSe2. The top and bottom layer densities can be independently tuned using the top and bottom gates, respectively, evincing a weak interlayer coupling. This work has been supported by NRI-SWAN and Intel corporation.
Millimeter-Wave Voltage-Controlled Oscillators in 0.13-micrometer CMOS Technology

DTIC Science & Technology

2006-06-01

controlled oscillators. Varactor , transistor, and in- ductor designs are optimized to reduce the parasitic capacitances. An investigation of tradeoff between...quality factor and tuning range for MOS varactors at 24 GHz has shown that the polysilicon gate lengths between 0.18 and 0.24 m result both good...millimeter wave, MOS varactor , quality factor, transmission line, voltage-controlled oscillator (VCO). I. INTRODUCTION WITH THE RAPID advance of high
X-Ray Lithographic Research: A Collection of NRL Contributions.

DTIC Science & Technology

1987-08-24

were studied threshold voltage I ( ,). conductance v,). conductance slope (slope of the k,, ,s gate , ,.oltage plot) and subthreshold swing factor (S...target interaction Resist Sensitivity which was sometimes present in the Technical Demonstration, would not be a factor in a dedi- cated laser system...representative irradiances are tabu- lated. Recent x-ray emission studies are cited, with commentary on the need for further mea- surement. Advances
Characteristics Of Ferroelectric Logic Gates Using a Spice-Based Model

NASA Technical Reports Server (NTRS)

MacLeod, Todd C.; Phillips, Thomas A.; Ho, Fat D.

2005-01-01

A SPICE-based model of an n-channel ferroelectric field effect transistor has been developed based on both theoretical and empirical data. This model was used to generate the I-V characteristic of several logic gates. The use of ferroelectric field effect transistors in memory circuits is being developed by several organizations. The use of FFETs in other circuits, both analog and digital needs to be better understood. The ability of FFETs to have different characteristics depending on the initial polarization can be used to create logic gates. These gates can have properties not available to standard CMOS logic gates, such as memory, reconfigurability and memory. This paper investigates basic properties of FFET logic gates. It models FFET inverter, NAND gate and multi-input NAND gate. The I-V characteristics of the gates are presented as well as transfer characteristics and timing. The model used is a SPICE-based model developed from empirical data from actual Ferroelectric transistors. It simulates all major characteristics of the ferroelectric transistor, including polarization, hysteresis and decay. Contrasts are made of the differences between FFET logic gates and CMOS logic gates. FFET parameters are varied to show the effect on the overall gate. A recodigurable gate is investigated which is not possible with CMOS circuits. The paper concludes that FFETs can be used in logic gates and have several advantages over standard CMOS gates.
What are the differences in driver injury outcomes at highway-rail grade crossings? Untangling the role of pre-crash behaviors.

PubMed

Liu, Jun; Khattak, Asad J; Richards, Stephen H; Nambisan, Shashi

2015-12-01

Crashes at highway-rail grade crossings can result in severe injuries and fatalities to vehicle occupants. Using a crash database from the Federal Railroad Administration (N=15,639 for 2004-2013), this study explores differences in safety outcomes from crashes between passive controls (Crossbucks and STOP signs) and active controls (flashing lights, gates, audible warnings and highway signals). To address missing data, an imputation model is developed, creating a complete dataset for estimation. Path analysis is used to quantify the direct and indirect associations of passive and active controls with pre-crash behaviors and crash outcomes in terms of injury severity. The framework untangles direct and indirect associations of controls by estimating two models, one for pre-crash driving behaviors (e.g., driving around active controls), and another model for injury severity. The results show that while the presence of gates is not directly associated with injury severity, the indirect effect through stopping behavior is statistically significant (95% confidence level) and substantial. Drivers are more likely to stop at gates that also have flashing lights and audible warnings, and stopping at gates is associated with lower injury severity. This indirect association lowers the chances of injury by 16%, compared with crashes at crossings without gates. Similar relationships between other controls and injury severity are explored. Generally, crashes occurring at active controls are less severe than crashes at passive controls. The results of study can be used to modify Crash Modification Factors (CMFs) to account for crash injury severity. The study contributes to enhancing the understanding of safety by incorporating pre-crash behaviors in a broader framework that quantifies correlates of crash injury severity at active and passive crossings. Copyright © 2015 Elsevier Ltd. All rights reserved.
Pharmacogenetics of new analgesics

PubMed Central

Lötsch, Jörn; Geisslinger, Gerd

2011-01-01

Patient phenotypes in pharmacological pain treatment varies between individuals, which could be partly assigned to their genotypes regarding the targets of classical analgesics (OPRM1, PTGS2) or associated signalling pathways (KCNJ6). Translational and genetic research have identified new targets, for which new analgesics are being developed. This addresses voltage-gated sodium, calcium and potassium channels, for which SCN9A, CACNA1B, KCNQ2 and KCNQ3, respectively, are primary gene candidates because they code for the subunits of the respective channels targeted by analgesics currently in clinical development. Mutations in voltage gated transient receptor potential (TRPV) channels are known from genetic pain research and may modulate the effects of analgesics under development targeting TRPV1 or TRPV3. To this add ligand-gated ion channels including nicotinic acetylcholine receptors, ionotropic glutamate-gated receptors and ATP-gated purinergic P2X receptors with most important subunits coded by CHRNA4, GRIN2B and P2RX7. Among G protein coupled receptors, δ-opioid receptors (coded by OPRD1), cannabinoid receptors (CNR1 and CNR2), metabotropic glutamate receptors (mGluR5 coded by GRM5), bradykinin B1 (BDKRB1) and 5-HT1A (HTR1A) receptors are targeted by new analgesic substances. Finally, nerve growth factor (NGFB), its tyrosine kinase receptor (NTRK1) and the fatty acid amide hydrolase (FAAH) have become targets of interest. For most of these genes, functional variants have been associated with neuro-psychiatric disorders and not yet with analgesia. However, research on the genetic modulation of pain has already identified variants in these genes, relative to pain, which may facilitate the pharmacogenetic assessments of new analgesics. The increased number of candidate pharmacogenetic modulators of analgesic actions may open opportunities for the broader clinical implementation of genotyping information. PMID:20942817
Comparison of lifetime-based methods for 2D phosphor thermometry in high-temperature environment

NASA Astrophysics Data System (ADS)

Peng, Di; Liu, Yingzheng; Zhao, Xiaofeng; Kim, Kyung Chun

2016-09-01

This paper discusses the currently available techniques for 2D phosphor thermometry, and compares the performance of two lifetime-based methods: high-speed imaging and the dual-gate. High-speed imaging resolves luminescent decay with a fast frame rate, and has become a popular method for phosphor thermometry in recent years. But it has disadvantages such as high equipment cost and long data processing time, and it would fail at sufficiently high temperature due to a low signal-to-noise ratio and short lifetime. The dual-gate method only requires two images on the decay curve and therefore greatly reduces cost in hardware and processing time. A dual-gate method for phosphor thermometry has been developed and compared with the high-speed imaging method through both calibration and a jet impingement experiment. Measurement uncertainty has been evaluated for a temperature range of 473-833 K. The effects of several key factors on uncertainty have been discussed, including the luminescent signal level, the decay lifetime and temperature sensitivity. The results show that both methods are valid for 2D temperature sensing within the given range. The high-speed imaging method shows less uncertainty at low temperatures where the signal level and the lifetime are both sufficient, but its performance is degraded at higher temperatures due to a rapidly reduced signal and lifetime. For T > 750 K, the dual-gate method outperforms the high-speed imaging method thanks to its superiority in signal-to-noise ratio and temperature sensitivity. The dual-gate method has great potential for applications in high-temperature environments where the high-speed imaging method is not applicable.
Voltage-gated Proton Channels

PubMed Central

DeCoursey, Thomas E.

2014-01-01

Voltage-gated proton channels, HV1, have vaulted from the realm of the esoteric into the forefront of a central question facing ion channel biophysicists, namely the mechanism by which voltage-dependent gating occurs. This transformation is the result of several factors. Identification of the gene in 2006 revealed that proton channels are homologues of the voltage-sensing domain of most other voltage-gated ion channels. Unique, or at least eccentric, properties of proton channels include dimeric architecture with dual conduction pathways, perfect proton selectivity, a single-channel conductance ~103 smaller than most ion channels, voltage-dependent gating that is strongly modulated by the pH gradient, ΔpH, and potent inhibition by Zn2+ (in many species) but an absence of other potent inhibitors. The recent identification of HV1 in three unicellular marine plankton species has dramatically expanded the phylogenetic family tree. Interest in proton channels in their own right has increased as important physiological roles have been identified in many cells. Proton channels trigger the bioluminescent flash of dinoflagellates, facilitate calcification by coccolithophores, regulate pH-dependent processes in eggs and sperm during fertilization, secrete acid to control the pH of airway fluids, facilitate histamine secretion by basophils, and play a signaling role in facilitating B-cell receptor mediated responses in B lymphocytes. The most elaborate and best-established functions occur in phagocytes, where proton channels optimize the activity of NADPH oxidase, an important producer of reactive oxygen species. Proton efflux mediated by HV1 balances the charge translocated across the membrane by electrons through NADPH oxidase, minimizes changes in cytoplasmic and phagosomal pH, limits osmotic swelling of the phagosome, and provides substrate H+ for the production of H2O2 and HOCl, reactive oxygen species crucial to killing pathogens. PMID:23798303
Effectiveness of respiratory-gated radiotherapy with audio-visual biofeedback for synchrotron-based scanned heavy-ion beam delivery

NASA Astrophysics Data System (ADS)

He, Pengbo; Li, Qiang; Zhao, Ting; Liu, Xinguo; Dai, Zhongying; Ma, Yuanyuan

2016-12-01

A synchrotron-based heavy-ion accelerator operates in pulse mode at a low repetition rate that is comparable to a patient’s breathing rate. To overcome inefficiencies and interplay effects between the residual motion of the target and the scanned heavy-ion beam delivery process for conventional free breathing (FB)-based gating therapy, a novel respiratory guidance method was developed to help patients synchronize their breathing patterns with the synchrotron excitation patterns by performing short breath holds with the aid of personalized audio-visual biofeedback (BFB) system. The purpose of this study was to evaluate the treatment precision, efficiency and reproducibility of the respiratory guidance method in scanned heavy-ion beam delivery mode. Using 96 breathing traces from eight healthy volunteers who were asked to breathe freely and guided to perform short breath holds with the aid of BFB, a series of dedicated four-dimensional dose calculations (4DDC) were performed on a geometric model which was developed assuming a linear relationship between external surrogate and internal tumor motions. The outcome of the 4DDCs was quantified in terms of the treatment time, dose-volume histograms (DVH) and dose homogeneity index. Our results show that with the respiratory guidance method the treatment efficiency increased by a factor of 2.23-3.94 compared with FB gating, depending on the duty cycle settings. The magnitude of dose inhomogeneity for the respiratory guidance methods was 7.5 times less than that of the non-gated irradiation, and good reproducibility of breathing guidance among different fractions was achieved. Thus, our study indicates that the respiratory guidance method not only improved the overall treatment efficiency of respiratory-gated scanned heavy-ion beam delivery, but also had the advantages of lower dose uncertainty and better reproducibility among fractions.
Bias stress instability of double-gate a-IGZO TFTs on polyimide substrate

NASA Astrophysics Data System (ADS)

Cho, Won-Ju; Ahn, Min-Ju

2017-09-01

In this study, flexible double-gate thin-film transistor (TFT)-based amorphous indium-galliumzinc- oxide (a-IGZO) was fabricated on a polyimide substrate. Double-gate operation with connected front and back gates was compared with a single-gate operation. As a result, the double-gate a- IGZO TFT exhibited enhanced electrical characteristics as well as improved long-term reliability. Under positive- and negative-bias temperature stress, the threshold voltage shift of the double-gate operation was much smaller than that of the single-gate operation.
Electron transporting water-gated thin film transistors

NASA Astrophysics Data System (ADS)

Al Naim, Abdullah; Grell, Martin

2012-10-01

We demonstrate an electron-transporting water-gated thin film transistor, using thermally converted precursor-route zinc-oxide (ZnO) intrinsic semiconductors with hexamethyldisilazene (HMDS) hydrophobic surface modification. Water gated HMDS-ZnO thin film transistors (TFT) display low threshold and high electron mobility. ZnO films constitute an attractive alternative to organic semiconductors for TFT transducers in sensor applications for waterborne analytes. Despite the use of an electrolyte as gate medium, the gate geometry (shape of gate electrode and distance between gate electrode and TFT channel) is relevant for optimum performance of water-gated TFTs.
Method and Apparatus for Simultaneous Processing of Multiple Functions

NASA Technical Reports Server (NTRS)

Stoica, Adrian (Inventor); Andrei, Radu (Inventor)

2017-01-01

Electronic logic gates that operate using N logic state levels, where N is greater than 2, and methods of operating such gates. The electronic logic gates operate according to truth tables. At least two input signals each having a logic state that can range over more than two logic states are provided to the logic gates. The logic gates each provide an output signal that can have one of N logic states. Examples of gates described include NAND/NAND gates having two inputs A and B and NAND/NAND gates having three inputs A, B, and C, where A, B and C can take any of four logic states. Systems using such gates are described, and their operation illustrated. Optical logic gates that operate using N logic state levels are also described.
Method and Apparatus for Simultaneous Processing of Multiple Functions

NASA Technical Reports Server (NTRS)

Stoica, Adrian (Inventor); Andrei, Radu (Inventor); Zhu, David (Inventor); Mojarradi, Mohammad Mehdi (Inventor); Vo, Tuan A. (Inventor)

2015-01-01

Electronic logic gates that operate using N logic state levels, where N is greater than 2, and methods of operating such gates. The electronic logic gates operate according to truth tables. At least two input signals each having a logic state that can range over more than two logic states are provided to the logic gates. The logic gates each provide an output signal that can have one of N logic states. Examples of gates described include NAND/NAND gates having two inputs A and B and NAND/NAND gates having three inputs A, B, and C, where A, B and C can take any of four logic states. Systems using such gates are described, and their operation illustrated. Optical logic gates that operate using N logic state levels are also described.
Discharge ratings for tainter gates and roller gates at Lock and Dam No. 7 on the Mississippi River, La Crescent, Minnesota

USGS Publications Warehouse

Corsi, Steven R.; Schuler, J.G.

1995-01-01

Coefficients of discharge (Cgs) ranged fron 0.126 (hg = 1 foot) to 1.089 (hg = 10 feet) for tainter gates and from 0.050 (hg = 1 foot) to 0.302 (hg = 14 feet) for roller gates. Disch^ge was measured at three different tainter gates with the gates closed (hg = 0) to evaluate tH tainter-gate leakage-discharge relations. No measurable leakage was observed. The resulting equations can be used to compute discharge at Lock and Dam No. 7 for the tainter and re Her gates under normal flow conditions. Discharge rating tables for the tainter and roller gates are given with a headwater elevation of 639.00 feet normal pool elevation for selected tailwate" elevations and gate openings.

Technical Note: High temporal resolution characterization of gating response time

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiersma, Rodney D., E-mail: rwiersma@uchicago.edu; McCabe, Bradley P.; Belcher, Andrew H.

2016-06-15

Purpose: Low temporal latency between a gating ON/OFF signal and the LINAC beam ON/OFF during respiratory gating is critical for patient safety. Here the authors describe a novel method to precisely measure gating lag times at high temporal resolutions. Methods: A respiratory gating simulator with an oscillating platform was modified to include a linear potentiometer for position measurement. A photon diode was placed at linear accelerator isocenter for beam output measurement. The output signals of the potentiometer and diode were recorded simultaneously at 2500 Hz with an analog to digital converter for four different commercial respiratory gating systems. The ONmore » and OFF of the beam signal were located and compared to the expected gating window for both phase and position based gating and the temporal lag times extracted. Results: For phase based gating, a real-time position management (RPM) infrared marker tracking system with a single camera and a RPM system with a stereoscopic camera were measured to have mean gate ON/OFF lag times of 98/90 and 86/44 ms, respectively. For position based gating, an AlignRT 3D surface system and a Calypso magnetic fiducial tracking system were measured to have mean gate ON/OFF lag times of 356/529 and 209/60 ms, respectively. Conclusions: Temporal resolution of the method was high enough to allow characterization of individual gate cycles and was primary limited by the sampling speed of the data recording device. Significant variation of mean gate ON/OFF lag time was found between different gating systems. For certain gating devices, individual gating cycle lag times can vary significantly.« less
Dual-gate polysilicon nanoribbon biosensors enable high sensitivity detection of proteins.

PubMed

Zeimpekis, I; Sun, K; Hu, C; Ditshego, N M J; Thomas, O; de Planque, M R R; Chong, H M H; Morgan, H; Ashburn, P

2016-04-22

We demonstrate the advantages of dual-gate polysilicon nanoribbon biosensors with a comprehensive evaluation of different measurement schemes for pH and protein sensing. In particular, we compare the detection of voltage and current changes when top- and bottom-gate bias is applied. Measurements of pH show that a large voltage shift of 491 mV pH(-1) is obtained in the subthreshold region when the top-gate is kept at a fixed potential and the bottom-gate is varied (voltage sweep). This is an improvement of 16 times over the 30 mV pH(-1) measured using a top-gate sweep with the bottom-gate at a fixed potential. A similar large voltage shift of 175 mV is obtained when the protein avidin is sensed using a bottom-gate sweep. This is an improvement of 20 times compared with the 8.8 mV achieved from a top-gate sweep. Current measurements using bottom-gate sweeps do not deliver the same signal amplification as when using bottom-gate sweeps to measure voltage shifts. Thus, for detecting a small signal change on protein binding, it is advantageous to employ a double-gate transistor and to measure a voltage shift using a bottom-gate sweep. For top-gate sweeps, the use of a dual-gate transistor enables the current sensitivity to be enhanced by applying a negative bias to the bottom-gate to reduce the carrier concentration in the nanoribbon. For pH measurements, the current sensitivity increases from 65% to 149% and for avidin sensing it increases from 1.4% to 2.5%.
Dual-gate polysilicon nanoribbon biosensors enable high sensitivity detection of proteins

NASA Astrophysics Data System (ADS)

Zeimpekis, I.; Sun, K.; Hu, C.; Ditshego, N. M. J.; Thomas, O.; de Planque, M. R. R.; Chong, H. M. H.; Morgan, H.; Ashburn, P.

2016-04-01

We demonstrate the advantages of dual-gate polysilicon nanoribbon biosensors with a comprehensive evaluation of different measurement schemes for pH and protein sensing. In particular, we compare the detection of voltage and current changes when top- and bottom-gate bias is applied. Measurements of pH show that a large voltage shift of 491 mV pH-1 is obtained in the subthreshold region when the top-gate is kept at a fixed potential and the bottom-gate is varied (voltage sweep). This is an improvement of 16 times over the 30 mV pH-1 measured using a top-gate sweep with the bottom-gate at a fixed potential. A similar large voltage shift of 175 mV is obtained when the protein avidin is sensed using a bottom-gate sweep. This is an improvement of 20 times compared with the 8.8 mV achieved from a top-gate sweep. Current measurements using bottom-gate sweeps do not deliver the same signal amplification as when using bottom-gate sweeps to measure voltage shifts. Thus, for detecting a small signal change on protein binding, it is advantageous to employ a double-gate transistor and to measure a voltage shift using a bottom-gate sweep. For top-gate sweeps, the use of a dual-gate transistor enables the current sensitivity to be enhanced by applying a negative bias to the bottom-gate to reduce the carrier concentration in the nanoribbon. For pH measurements, the current sensitivity increases from 65% to 149% and for avidin sensing it increases from 1.4% to 2.5%.
Dropping Out of School in Southern Ghana: The Push-Out and Pull-Out Factors. CREATE Pathways to Access. Research Monograph No. 55

ERIC Educational Resources Information Center

Ananga, Eric

2011-01-01

Addressing school dropout has been one of the most controversial elements of policy since the introduction of free compulsory universal basic education (FCUBE) in Ghana. However, research that utilises qualitative biographical detail surrounding irregular attendance and the critical events in the process that lead to dropout in Ghana is limited. I…
Success Stories on Non-Formal Adult Education and Training for Self-Employment in Micro-Enterprises in South Africa

ERIC Educational Resources Information Center

Mayombe, Celestin

2017-01-01

Purpose: The purpose of this paper is to investigate the way the adult non-formal education and training (NFET) centres motivated and empowered graduates to start their own micro-enterprises as individuals or as a group. The specific objectives are as follows: to find out the transforming factors fostering the utilisation of acquired skills into…
The Moderating Role of Self-Regulated Learning in Job Characteristics and Attitudes towards Web-Based Continuing Learning in the Airlines Workplace

ERIC Educational Resources Information Center

Lin, Xiao-fan; Liang, Jyh-Chong; Tsai, Chin-Chung; Hu, Qintai

2018-01-01

With the increasing importance of adult and continuing education, the present study aimed to examine the factors that influence continuing web-based learning at work. Three questionnaires were utilised to investigate the association of the job characteristics from Karasek et al.'s (1998) job demand-control-support model and the self-regulated…
Voltage-dependent K+ channel gating and voltage sensor toxin sensitivity depend on the mechanical state of the lipid membrane.

PubMed

Schmidt, Daniel; MacKinnon, Roderick

2008-12-09

Voltage-dependent K(+) (Kv) channels underlie action potentials through gating conformational changes that are driven by membrane voltage. In this study of the paddle chimera Kv channel, we demonstrate that the rate of channel opening, the voltage dependence of the open probability, and the maximum achievable open probability depend on the lipid membrane environment. The activity of the voltage sensor toxin VsTx1, which interferes with voltage-dependent gating by partitioning into the membrane and binding to the channel, also depends on the membrane. Membrane environmental factors that influence channel function are divisible into two general categories: lipid compositional and mechanical state. The mechanical state can have a surprisingly large effect on the function of a voltage-dependent K(+) channel, including its pharmacological interaction with voltage sensor toxins. The dependence of VSTx1 activity on the mechanical state of the membrane leads us to hypothesize that voltage sensor toxins exert their effect by perturbing the interaction forces that exist between the channel and the membrane.
Time domain diffuse Raman spectrometer based on a TCSPC camera for the depth analysis of diffusive media.

PubMed

Konugolu Venkata Sekar, S; Mosca, S; Tannert, S; Valentini, G; Martelli, F; Binzoni, T; Prokazov, Y; Turbin, E; Zuschratter, W; Erdmann, R; Pifferi, A

2018-05-01

We present a time domain diffuse Raman spectrometer for depth probing of highly scattering media. The system is based on, to the best of our knowledge, a novel time-correlated single-photon counting (TCSPC) camera that simultaneously acquires both spectral and temporal information of Raman photons. A dedicated non-contact probe was built, and time domain Raman measurements were performed on a tissue mimicking bilayer phantom. The fluorescence contamination of the Raman signal was eliminated by early time gating (0-212 ps) the Raman photons. Depth sensitivity is achieved by time gating Raman photons at different delays with a gate width of 106 ps. Importantly, the time domain can provide time-dependent depth sensitivity leading to a high contrast between two layers of Raman signal. As a result, an enhancement factor of 2170 was found for our bilayer phantom which is much higher than the values obtained by spatial offset Raman spectroscopy (SORS), frequency offset Raman spectroscopy (FORS), or hybrid FORS-SORS on a similar phantom.
Quantum transport of two-species Dirac fermions in dual-gated three-dimensional topological insulators

DOE PAGES

Xu, Yang; Miotkowski, Ireneusz; Chen, Yong P.

2016-05-04

Topological insulators are a novel class of quantum matter with a gapped insulating bulk, yet gapless spin-helical Dirac fermion conducting surface states. Here, we report local and non-local electrical and magneto transport measurements in dual-gated BiSbTeSe 2 thin film topological insulator devices, with conduction dominated by the spatially separated top and bottom surfaces, each hosting a single species of Dirac fermions with independent gate control over the carrier type and density. We observe many intriguing quantum transport phenomena in such a fully tunable two-species topological Dirac gas, including a zero-magnetic-field minimum conductivity close to twice the conductance quantum at themore » double Dirac point, a series of ambipolar two-component half-integer Dirac quantum Hall states and an electron-hole total filling factor zero state (with a zero-Hall plateau), exhibiting dissipationless (chiral) and dissipative (non-chiral) edge conduction, respectively. As a result, such a system paves the way to explore rich physics, ranging from topological magnetoelectric effects to exciton condensation.« less
Analysis of high-k spacer on symmetric underlap DG-MOSFET with Gate Stack architecture

NASA Astrophysics Data System (ADS)

Das, Rahul; Chakraborty, Shramana; Dasgupta, Arpan; Dutta, Arka; Kundu, Atanu; Sarkar, Chandan K.

2016-09-01

This paper shows the systematic study of underlap double gate (U-DG) NMOSFETs with Gate Stack (GS) under the influence of high-k spacers. In highly scaled devices, underlap is used at the Source and Drain side so as to reduce the short channel effects (SCE's), however, it significantly reduces the on current due to the increased channel resistance. To overcome these drawbacks, the use of high-k spacers is projected as one of the remedies. In this paper, the analog performance of the devices is studied on the basis of parameters like transconductance (gm), transconductance generation factor (gm/Id) and intrinsic gain (gmro). The RF performance is analyzed on the merits of intrinsic capacitance (Cgd, Cgs), resistance (Rgd, Rgs), transport delay (τm), inductance (Lsd), cutoff frequency (fT), and the maximum frequency of oscillation (fmax). The circuit performance of the devices are studied by implementing the device as the driver MOSFET in a Single Stage Common Source Amplifier. The Gain Bandwidth Product (GBW) has been analyzed from the frequency response of the circuit.
Does Autoimmunity have a Role in Myoclonic Astatic Epilepsy? A Case Report of Voltage Gated Potassium Channel Mediated Seizures.

PubMed

Sirsi, Deepa; Dolce, Alison; Greenberg, Benjamin M; Thodeson, Drew

2016-01-01

There is expanding knowledge about the phenotypic variability of patients with voltage gated potassium channel complex (VGKC) antibody mediated neurologic disorders. The phenotypes are diverse and involve disorders of the central and peripheral nervous systems. The central nervous system manifestations described in the literature include limbic encephalitis, status epilepticus, and acute encephalitis. We report a 4.5 year-old boy who presented with intractable Myoclonic Astatic Epilepsy (MAE) or Doose syndrome and positive VGKC antibodies in serum. Treatment with steroids led to resolution of seizures and electrographic normalization. This case widens the spectrum of etiologies for MAE to include autoimmunity, in particular VGKC auto-antibodies and CNS inflammation, as a primary or contributing factor. There is an evolving understanding of voltage gated potassium channel complex mediated autoimmunity in children and the role of inflammation and autoimmunity in MAE and other intractable pediatric epilepsy syndromes remains to be fully defined. A high index of suspicion is required for diagnosis and appropriate management of antibody mediated epilepsy syndromes.
Effects of protein inter-layers on cell-diamond FET characteristics.

PubMed

Rezek, Bohuslav; Krátká, Marie; Kromka, Alexander; Kalbacova, Marie

2010-12-15

Diamond is recognized as an attractive material for merging solid-state and biological systems. The advantage of diamond field-effect transistors (FET) is that they are chemically resistant, bio-compatible, and can operate without gate oxides. Solution-gated FETs based on H-terminated nanocrystalline diamond films exhibiting surface conductivity are employed here for studying effects of fetal bovine serum (FBS) proteins and osteoblastic SAOS-2 cells on diamond electronic properties. FBS proteins adsorbed on the diamond FETs permanently decrease diamond conductivity as reflected by the -45 mV shift of the FET transfer characteristics. Cell cultivation for 2 days results in a further shift by another -78 mV. We attribute it to a change of diamond material properties rather than purely to the field-effect. Increase in gate leakage currents (by a factor of 4) indicates that the FBS proteins also decrease the diamond-electrolyte electronic barrier induced by C-H surface dipoles. We propose a model where the proteins replace ions in the very vicinity of the H-terminated diamond surface. Copyright © 2010 Elsevier B.V. All rights reserved.
Voltage-dependent K+ channel gating and voltage sensor toxin sensitivity depend on the mechanical state of the lipid membrane

PubMed Central

Schmidt, Daniel; MacKinnon, Roderick

2008-01-01

Voltage-dependent K+ (Kv) channels underlie action potentials through gating conformational changes that are driven by membrane voltage. In this study of the paddle chimera Kv channel, we demonstrate that the rate of channel opening, the voltage dependence of the open probability, and the maximum achievable open probability depend on the lipid membrane environment. The activity of the voltage sensor toxin VsTx1, which interferes with voltage-dependent gating by partitioning into the membrane and binding to the channel, also depends on the membrane. Membrane environmental factors that influence channel function are divisible into two general categories: lipid compositional and mechanical state. The mechanical state can have a surprisingly large effect on the function of a voltage-dependent K+ channel, including its pharmacological interaction with voltage sensor toxins. The dependence of VSTx1 activity on the mechanical state of the membrane leads us to hypothesize that voltage sensor toxins exert their effect by perturbing the interaction forces that exist between the channel and the membrane. PMID:19050073
Carbon Nanotube Self-Gating Diode and Application in Integrated Circuits.

PubMed

Si, Jia; Liu, Lijun; Wang, Fanglin; Zhang, Zhiyong; Peng, Lian-Mao

2016-07-26

A nano self-gating diode (SGD) based on nanoscale semiconducting material is proposed, simulated, and realized on semiconducting carbon nanotubes (CNTs) through a doping-free fabrication process. The relationships between the performance and material/structural parameters of the SGD are explored through numerical simulation and verified by experiment results. Based on these results, performance optimization strategy is outlined, and high performance CNT SGDs are fabricated and demonstrated to surpass other published CNT diodes. In particular the CNT SGD exhibits high rectifier factor of up to 1.4 × 10(6) while retains large on-state current. Benefiting from high yield and stability, CNT SGDs are used for constructing logic and analog integrated circuits. Two kinds of basic digital gates (AND and OR) have been realized on chip through using CNT SGDs and on-chip Ti wire resistances, and a full wave rectifier circuit has been demonstrated through using two CNT SGDs. Although demonstrated here using CNT SGDs, this device structure may in principle be implemented using other semiconducting nanomaterials, to provide ideas and building blocks for electronic applications based on nanoscale materials.
Control of terahertz nonlinear transmission with electrically gated graphene metadevices.

PubMed

Choi, Hyun Joo; Baek, In Hyung; Kang, Bong Joo; Kim, Hyeon-Don; Oh, Sang Soon; Hamm, Joachim M; Pusch, Andreas; Park, Jagang; Lee, Kanghee; Son, Jaehyeon; Jeong, Young U K; Hess, Ortwin; Rotermund, Fabian; Min, Bumki

2017-02-20

Graphene, which is a two-dimensional crystal of carbon atoms arranged in a hexagonal lattice, has attracted a great amount of attention due to its outstanding mechanical, thermal and electronic properties. Moreover, graphene shows an exceptionally strong tunable light-matter interaction that depends on the Fermi level - a function of chemical doping and external gate voltage - and the electromagnetic resonance provided by intentionally engineered structures. In the optical regime, the nonlinearities of graphene originated from the Pauli blocking have already been exploited for mode-locking device applications in ultrafast laser technology, whereas nonlinearities in the terahertz regime, which arise from a reduction in conductivity due to carrier heating, have only recently been confirmed experimentally. Here, we investigated two key factors for controlling nonlinear interactions of graphene with an intense terahertz field. The induced transparencies of graphene can be controlled effectively by engineering meta-atoms and/or changing the number of charge carriers through electrical gating. Additionally, nonlinear phase changes of the transmitted terahertz field can be observed by introducing the resonances of the meta-atoms.
Density-controlled quantum Hall ferromagnetic transition in a two-dimensional hole system

DOE PAGES

Lu, T. M.; Tracy, L. A.; Laroche, D.; ...

2017-06-01

We typically achieve Quantum Hall ferromagnetic transitions by increasing the Zeeman energy through in-situ sample rotation, while transitions in systems with pseudo-spin indices can be induced by gate control. We report here a gate-controlled quantum Hall ferromagnetic transition between two real spin states in a conventional two-dimensional system without any in-plane magnetic field. We also show that the ratio of the Zeeman splitting to the cyclotron gap in a Ge two-dimensional hole system increases with decreasing density owing to inter-carrier interactions. Below a critical density of ~2.4 × 10 10 cm -2, this ratio grows greater than 1, resulting inmore » a ferromagnetic ground state at filling factor ν = 2. At the critical density, a resistance peak due to the formation of microscopic domains of opposite spin orientations is observed. For such gate-controlled spin-polarizations in the quantum Hall regime the door opens in order to realize Majorana modes using two-dimensional systems in conventional, low-spin-orbit-coupling semiconductors.« less
Does Autoimmunity have a Role in Myoclonic Astatic Epilepsy? A Case Report of Voltage Gated Potassium Channel Mediated Seizures

PubMed Central

Sirsi, Deepa; Dolce, Alison; Greenberg, Benjamin M; Thodeson, Drew

2017-01-01

Background There is expanding knowledge about the phenotypic variability of patients with voltage gated potassium channel complex (VGKC) antibody mediated neurologic disorders. The phenotypes are diverse and involve disorders of the central and peripheral nervous systems. The central nervous system manifestations described in the literature include limbic encephalitis, status epilepticus, and acute encephalitis. Patient Description We report a 4.5 year-old boy who presented with intractable Myoclonic Astatic Epilepsy (MAE) or Doose syndrome and positive VGKC antibodies in serum. Treatment with steroids led to resolution of seizures and electrographic normalization. Conclusion This case widens the spectrum of etiologies for MAE to include autoimmunity, in particular VGKC auto-antibodies and CNS inflammation, as a primary or contributing factor. There is an evolving understanding of voltage gated potassium channel complex mediated autoimmunity in children and the role of inflammation and autoimmunity in MAE and other intractable pediatric epilepsy syndromes remains to be fully defined. A high index of suspicion is required for diagnosis and appropriate management of antibody mediated epilepsy syndromes. PMID:29308451
Density-controlled quantum Hall ferromagnetic transition in a two-dimensional hole system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, T. M.; Tracy, L. A.; Laroche, D.

We typically achieve Quantum Hall ferromagnetic transitions by increasing the Zeeman energy through in-situ sample rotation, while transitions in systems with pseudo-spin indices can be induced by gate control. We report here a gate-controlled quantum Hall ferromagnetic transition between two real spin states in a conventional two-dimensional system without any in-plane magnetic field. We also show that the ratio of the Zeeman splitting to the cyclotron gap in a Ge two-dimensional hole system increases with decreasing density owing to inter-carrier interactions. Below a critical density of ~2.4 × 10 10 cm -2, this ratio grows greater than 1, resulting inmore » a ferromagnetic ground state at filling factor ν = 2. At the critical density, a resistance peak due to the formation of microscopic domains of opposite spin orientations is observed. For such gate-controlled spin-polarizations in the quantum Hall regime the door opens in order to realize Majorana modes using two-dimensional systems in conventional, low-spin-orbit-coupling semiconductors.« less
HIV-related knowledge, perceptions, attitudes, and utilisation of HIV counselling and testing: a venue-based intercept commuter population survey in the inner city of Johannesburg, South Africa.

PubMed

Chimoyi, Lucy; Tshuma, Ndumiso; Muloongo, Keith; Setswe, Geoffrey; Sarfo, Bismark; Nyasulu, Peter S

2015-01-01

HIV counselling and testing (HCT) and knowledge about HIV have been key strategies utilised in the prevention and control of HIV/AIDS worldwide. HIV knowledge and uptake of HCT services in sub-Saharan Africa are still low. This study was conducted to determine factors associated with HCT and HIV/AIDS knowledge levels among a commuter population in Johannesburg, South Africa. To identify the factors associated with HCT uptake among the commuter population. A simple random sampling method was used to select participants in a venue-based intercept survey at a taxi rank in the Johannesburg Central Business District. Data were collected using an electronic questionnaire. Logistic regression analysis assessed factors associated with HIV testing stratified by gender. 1,146 respondents were interviewed, the maority (n=579, 50.5%) were females and (n=780, 68.1%) were over 25 years of age. Overall HCT knowledge was high (n=951, 83%) with more females utilising HCT facilities. There was a significant difference in HIV testing for respondents living closer to and further away from health facilities. Slightly more than half of the respondents indicated stigma as one of the barriers for testing (n=594, 52%, p-value=0.001). For males, living with a partner (aOR: 1.68, 95% CI: 1.02-2.78, p-value: 0.041) and possessing a post-primary education were positively associated with testing (aOR: 2.00, 95% CI: 1.15-3.47, p-value: 0.014), whereas stigma and discrimination reduced the likelihood of testing (aOR: 0.40, 95% CI: 0.31-0.62, p-value: <0.001). For females, having one sexual partner (aOR: 2.65, 95% CI: 1.19-5.90, p-value: 0.017) and a low perceived benefit for HIV testing (aOR: 0.54, 95% CI: 0.30-0.96, p-value: 0.035) were associated with HIV testing. The overall HIV/AIDS knowledge was generally high. Gender-specific health education and HIV intervention programmes are needed for improved access to HCT services. One favourable intervention would be the use of home-based HCT programmes.
Enhanced transconductance in a double-gate graphene field-effect transistor

NASA Astrophysics Data System (ADS)

Hwang, Byeong-Woon; Yeom, Hye-In; Kim, Daewon; Kim, Choong-Ki; Lee, Dongil; Choi, Yang-Kyu

2018-03-01

Multi-gate transistors, such as double-gate, tri-gate and gate-all-around transistors are the most advanced Si transistor structure today. Here, a genuine double-gate transistor with a graphene channel is experimentally demonstrated. The top and bottom gates of the double-gate graphene field-effect transistor (DG GFET) are electrically connected so that the conductivity of the graphene channel can be modulated simultaneously by both the top and bottom gate. A single-gate graphene field-effect transistor (SG GFET) with only the top gate is also fabricated as a control device. For systematical analysis, the transfer characteristics of both GFETs were measured and compared. Whereas the maximum transconductance of the SG GFET was 17.1 μS/μm, that of the DG GFET was 25.7 μS/μm, which is approximately a 50% enhancement. The enhancement of the transconductance was reproduced and comprehensively explained by a physics-based compact model for GFETs. The investigation of the enhanced transfer characteristics of the DG GFET in this work shows the possibility of a multi-gate architecture for high-performance graphene transistor technology.

Relationship of Coronary Calcium on Standard Chest CT Scans With Mortality.

PubMed

Hughes-Austin, Jan M; Dominguez, Arturo; Allison, Matthew A; Wassel, Christina L; Rifkin, Dena E; Morgan, Cindy G; Daniels, Michael R; Ikram, Umaira; Knox, Jessica B; Wright, C Michael; Criqui, Michael H; Ix, Joachim H

2016-02-01

The aim of this study was to determine the correlation between coronary artery calcium (CAC) scores on 3 mm electrocardiography (ECG)-gated computed tomography (CT) scans and standard 6 mm chest CT scans, and to compare relative strength of associations of CAC on each scan type with mortality risk. Coronary artery calcification predicts cardiovascular disease (CVD) and all-cause mortality, and is typically measured on ECG-gated 3 mm CT scans. Patients undergo standard 6 mm chest CTs for various clinical indications much more frequently, but CAC is not usually quantified. To better understand the usefulness of standard chest CTs to quantify CAC, we conducted a case-control study among persons who had both scan types. Between 2000 and 2003, 4,544 community-living individuals self- or physician-referred for "whole-body" CT scans, had 3 mm ECG-gated CTs and standard 6 mm chest CTs, and were followed for mortality through 2009. In this nested case-control study, we identified 157 deaths and 494 controls frequency matched (1:3) on age and sex. The Agatston method quantified CAC on both scan types. Unconditional logistic regression determined associations with mortality, accounting for CVD risk factors. Participants were 68 ± 11 years of age and 63% male. The Spearman correlation of CAC scores between the 2 scan types was 0.93 (p < 0.001); median CAC scores were lower on 6 mm CTs compared to 3 mm CTs (22 vs.104 Agatston units, p < 0.001). Adjusted for traditional CVD risk factors, each standard deviation higher CAC score on 6 mm CTs was associated with 50% higher odds of death (odds ratio: 1.5; 95% confidence interval: 1.2 to 1.9), similar to 50% higher odds on the 3 mm ECG-gated CTs (odds ratio: 1.5; 95% confidence interval: 1.1 to 1.9). CAC scores on standard 6 mm chest CTs are strongly correlated with 3 mm ECG-gated CTs and similarly predict mortality in community-living individuals. Chest CTs performed for other clinical indications may provide an untapped resource to garner CVD risk information without additional radiation exposure or expense. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
Measuring and decomposing socioeconomic inequality in healthcare delivery: A microsimulation approach with application to the Palestinian conflict-affected fragile setting.

PubMed

Abu-Zaineh, Mohammad; Mataria, Awad; Moatti, Jean-Paul; Ventelou, Bruno

2011-01-01

Socioeconomic-related inequalities in healthcare delivery have been extensively studied in developed countries, using standard linear models of decomposition. This paper seeks to assess equity in healthcare delivery in the particular context of the occupied Palestinian territory: the West Bank and the Gaza Strip, using a new method of decomposition based on microsimulations. Besides avoiding the 'unavoidable price' of linearity restriction that is imposed by the standard methods of decomposition, the microsimulation-based decomposition enables to circumvent the potentially contentious role of heterogeneity in behaviours and to better disentangle the various sources driving inequality in healthcare utilisation. Results suggest that the worse-off do have a disproportinately greater need for all levels of care. However with the exception of primary-level, utilisation of all levels of care appears to be significantly higher for the better-off. The microsimulation method has made it possible to identify the contributions of factors driving such pro-rich patterns. While much of the inequality in utilisation appears to be caused by the prevailing socioeconomic inequalities, detailed analysis attributes a non-trivial part (circa 30% of inequalities) to heterogeneity in healthcare-seeking behaviours across socioeconomic groups of the population. Several policy recommendations for improving equity in healthcare delivery in the occupied Palestinian territory are proposed. Copyright Â© 2010 Elsevier Ltd. All rights reserved.
Influence of non-preferred foot technical training in reducing lower limbs functional asymmetry among young football players.

PubMed

Guilherme, José; Garganta, Júlio; Graça, Amândio; Seabra, André

2015-01-01

The functional asymmetry of the lower limbs has been regarded as a relevant factor of the performance of football players. We purposed to ascertain whether a specific technical training programme for the non-preferred foot has implications in the increasing utilisation rate of the respective member during the game. Young football players (n = 71) were randomly divided into experimental group (N = 35; 14.37 ± 1.94 years) and control group (N = 36; 14.50 ± 1.81 years). The study was developed into three stages: first, assessment of the index utilisation of both limbs during the game; second, application of a technical training programme that includes the drilling of specific motor skills exclusively directed to the non-preferred foot; and third, assessment of the new rate of both limbs' utilisation after the predefined six months. The main findings were: (1) the use of the non-preferred foot increased significantly with the technical training programme in the experimental group and remained constant in the control group; (2) the use of the preferred foot decreased significantly in the experimental group and remained similar in control group. We concluded that a systematic and specific technical training for the non-preferred foot increases its use and reduces functional asymmetry in game situation, consequently improving the player's performance.
Pilot implementation of allied health assistant roles within publicly funded health services in Queensland, Australia: results of a workplace audit

PubMed Central

2014-01-01

Background Allied health assistants provide delegated support for physical therapists, occupational therapists and other allied health professionals. Unfortunately the role statements, scope of practice and career pathways of these assistant positions are often unclear. To inform the future development of the allied health assistant workforce, a state-wide pilot project was implemented and audited. Methods New allied health assistant positions were implemented in numerous settings at three levels (trainee level, full (standard) scope and advanced scope level). Six months after implementation, 41 positions were audited, using a detailed on-site audit process, conducted by multiple audit teams. Results Thematically analysed audit findings indicated that both the full (standard) scope and the advanced scope positions were warranted, however the skills of the allied health assistants were not optimally utilised. Contributing factors to this underutilization included the reluctance of professionals to delegate clinical tasks, inconsistencies in role descriptions, limitations in training, and the time frame taken to reach an effective skill level. Conclusions Optimal utilisation of assistants is unlikely to occur while professionals withhold delegation of tasks related to direct patient care. Formal clinical supervision arrangements and training plans should be established in order to address the concerns of professionals and accelerate full utilisation of assistants. Further work is necessary to identify the key components and distinguish key features of an advanced allied health assistant role. PMID:24935749
Factors That Impact Evaluation of Left Ventricular Systolic Parameters in Myocardial Perfusion Gated SPECT with 16 Frame and 8 Frame Acquisition Models.

PubMed

Ansari, Mojtaba; Hashemi, Hoda; Soltanshahi, Mehdi; Qutbi, Mohsen; Azizmohammadi, Zahra; Tabeie, Faraj; Javadi, Hamid; Jafari, Esmail; Barekat, Maryam; Assadi, Majid

2018-06-07

Evaluating the effects of heart cavity volume, presence and absence of perfusion defect, gender and type of study (stress and rest) on the difference of systolic parameters of myocardial perfusion scan in 16 and 8 framing gated SPECT imaging. Cardiac gated SPECT in both 16 and 8 framing simultaneously and both stress and rest phases at one-day protocol was performed for 50 patients. Data have been reconstructed by filter back projection (FBP) method and left ventricular (LV) systolic parameters were calculated by using QGS software. The effect of some factors such as LV cavity volume, presence and absence of perfusion defect, gender and type of study on data difference between 8 and 16 frames were evaluated. The differences in ejection fraction (EF), end-diastolic volume (EDV) and end-systolic volume (ESV) in both stress and rest were statistically significant. Difference in both framing was more in stress for EF and ESV, and was more in rest for EDV. Study type had a significant effect on differences in systolic parameters while gender had a significant effect on differences in EF and ESV in rest between both framings. In conclusion, results of this study revealed that difference of both 16 and 8 frames data in systolic phase were statistically significant and it seems that because of better efficiency of 16 frames, it cannot be replaced by 8 frames. Further well-designed studies are required to verify these findings.
Effect of strained Ge-based NMOSFETs with Ge0.93Si0.07 stressors on device layout

NASA Astrophysics Data System (ADS)

Hsu, Hung-Wen; Lee, Chang-Chun

2017-12-01

This research proposes a germanium (Ge)-based n-channel MOSFET with Ge0.93Si0.07 S/D stressor. A simulation technique is utilized to understand the layout effect of shallow trench isolation (STI) length, gate width, dummy active of diffusion (OD) length, and extended poly width on stress distribution in a channel region. Stress distribution in a channel region was simulated by ANSYS software based on finite element analysis. Furthermore, carrier mobility gain was evaluated by a second-order piezoresistance model. The piezoresistance coefficient of Ge nMOSFET varies from that of Si nMOSFET. The piezoresistance coefficient shows that longitudinal and transverse stresses are the dominant factors affecting the change in electron mobility in the channel region. For Ge-based nMOSFET, longitudinal stress tends to be tensile, whereas transverse stress tends to be compressive. Stress along channel length becomes more tensile when STI length decreases. By contrast, stress along the channel width becomes more compressive when gate width or extended poly width decreases. Electron mobility in Ge-based nMOSFET could be enhanced under the aforementioned conditions. The enhanced electron mobility becomes more significant as the device combines with a contact etching stop layer stressor. Moreover, the mobility can be improved by changing the STI length, gate width, dummy OD length, or extended poly width. This investigation systematically analyzed the relationship between layout factor and stress distribution.
Profiling of cardio-metabolic risk factors and medication utilisation among Type II diabetes patients in Ghana: a prospective cohort study.

PubMed

Adua, Eric; Roberts, Peter; Sakyi, Samuel Asamoah; Yeboah, Francis Agyemang; Dompreh, Albert; Frimpong, Kwasi; Anto, Enoch Odame; Wang, Wei

2017-09-07

Type II diabetes mellitus (T2DM) is complicated by multiple cardio-metabolic risk factors. Controlling these factors requires lifestyle modifications alongside utilisation of anti-diabetic medications. Different glucose lowering [(biguanides (BIGs), sulfonylureas (SUAs), thiazolidinediones (TNZ)], lipid lowering (statins), and anti-hypertensive medicines [angiotensin converting enzyme inhibitors (ACEIs), calcium channel blockers (CCBs), angiotensin II receptor blockers (ARBs) and central acting drugs (CADs)] have been approved for controlling hyperglycaemia, dyslipidaemia and hypertension respectively. Here, we examined factors that characterise T2DM and explored the response to medication therapy among T2DM patients. This prospective cohort study recruited 241 T2DM patients reporting at a clinic in Ghana, from January through to August, 2016. Each patient's demographic, medications and anthropometric data was obtained while information on medication adherence was captured using Morisky adherence scale-8 (MMAS-8). Fasting blood samples were collected for biochemical analysis. The mean age of participants was 57.82 years for baseline and six-month follow-up. Physical activity differed at baseline and follow up (p < 0.05) but not body mass index (BMI). BIG alone, or in combination with SUA and TNZ did not improve glycaemic status at follow up (p > 0.05). Many participants using either ACEI or ARB were able to control their blood pressures. Among dyslipidaemia patients under statin treatment, there was an improved lipid profile at follow-up. Statin medications are effective for reducing dyslipidaemia in T2DM patients. However, control of modifiable risk factors, particularly blood glucose and to a lesser degree blood pressure is suboptimal. Addressing these will require concomitant interventions including education on medication adherence and correct dietary plans, lifestyle modifications and physical activity.
Identifying factors associated with fast food consumption among adolescents in Beijing China using a theory-based approach.

PubMed

Ma, R; Castellanos, D C; Bachman, J

2016-07-01

China is in the midst of the nutrition transition with increasing rates of obesity and dietary changes. One contributor is the increase in fast food chains within the country. The purpose of this study was to develop a theory-based instrument that explores influencing factors of fast food consumption in adolescents residing in Beijing, China. Cross-sectional study. Value expectancy and theory of planned behaviour were utilised to explore influencing factors of fast food consumption in the target population. There were 201 Chinese adolescents between the ages of 12 and 18. Cronbach's alpha correlation coefficients were used to examine internal reliability of the theory-based questionnaire. Bivariate correlations and a MANOVA were utilised to determine the relationship between theory-based constructs, body mass index (BMI)-for-age and fast food intake frequency as well as to determine differences in theory-based scores among fast food consumption frequency groupings. The theory-based questionnaire showed good reliability. Furthermore, there was a significant difference in the theory-based subcategory scores between fast food frequency groups. A significant positive correlation was observed between times per week fast food was consumed and each theory-based subscale score. Using BMI-for-age of 176 participants, 81% were normal weight and 19% were considered overweight or obese. Results showed consumption of fast food to be on average 1.50 ± 1.33 per week. The relationship between BMI-for-age and times per week fast food was consumed was not significant. As the nutrition transition continues and fast food chains expand, it is important to explore factors effecting fast food consumption in China. Interventions targeting influencing factors can be developed to encourage healthy dietary choice in the midst of this transition. Copyright © 2016. Published by Elsevier Ltd.
INHIBITION OF HUMAN A7 NEURONAL NICOTINIC ACETYLCHOLINE RECEPTORS BY THE VOLATILE ORGANIC SOLVENT TRICHLOROETHYLENE.

EPA Science Inventory

Volatile organic compounds such as toleune, trichloroethylene and perchloroethylene are potent and reversible blockers of voltage-gated calcium current in nerve growth factor (NGF)-differentiated pheochromocytoma (PC12) cells. It is hypothesized that effects of VOCs on ICa contri...
Prior Driver Performance and Expressed Attitudes Toward Risk as Factors Associated With Railroad Grade Crossing Violations

DOT National Transportation Integrated Search

1999-06-01

Railroad 'gate runners' identified by photo surveillance instrumentation were contrasted with a sample of general 'users' of the same grade crossing. The two samples were contrasted in terms of the prior driving histories of the drivers involved. In ...
Field effect transistor and method of construction thereof

NASA Technical Reports Server (NTRS)

Fletner, W. R. (Inventor)

1978-01-01

A field effect transistor is constructed by placing a semi-conductor layer on an insulating substrate so that the gate region is separated from source and drain regions. The gate electrode and gate region of the layer are of generally reduced length, the gate region being of greatest length on its surface closest to the gate electrode. This is accomplished by initially creating a relatively large gate region of one polarity, and then reversing the polarity of a central portion of this gate region by ion bombardment, thus achieving a narrower final gate region of the stated configuration.
Longitudinal study of factors affecting taste sense decline in old-old individuals.

PubMed

Ogawa, T; Uota, M; Ikebe, K; Arai, Y; Kamide, K; Gondo, Y; Masui, Y; Ishizaki, T; Inomata, C; Takeshita, H; Mihara, Y; Hatta, K; Maeda, Y

2017-01-01

The sense of taste plays a pivotal role for personal assessment of the nutritional value, safety and quality of foods. Although it is commonly recognised that taste sensitivity decreases with age, alterations in that sensitivity over time in an old-old population have not been previously reported. Furthermore, no known studies utilised comprehensive variables regarding taste changes and related factors for assessments. Here, we report novel findings from a 3-year longitudinal study model aimed to elucidate taste sensitivity decline and its related factors in old-old individuals. We utilised 621 subjects aged 79-81 years who participated in the Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians Study for baseline assessments performed in 2011 and 2012, and then conducted follow-up assessments 3 years later in 328 of those. Assessment of general health, an oral examination and determination of taste sensitivity were performed for each. We also evaluated cognitive function using Montreal Cognitive Assessment findings, then excluded from analysis those with a score lower than 20 in order to secure the validity and reliability of the subjects' answers. Contributing variables were selected using univariate analysis, then analysed with multivariate logistic regression analysis. We found that males showed significantly greater declines in taste sensitivity for sweet and sour tastes than females. Additionally, subjects with lower cognitive scores showed a significantly greater taste decrease for salty in multivariate analysis. In conclusion, our longitudinal study revealed that gender and cognitive status are major factors affecting taste sensitivity in geriatric individuals. © 2016 John Wiley & Sons Ltd.
Prevalence, risk factors and health outcomes associated with polypharmacy among urban community-dwelling older adults in multi-ethnic Malaysia.

PubMed

Lim, Li Min; McStea, Megan; Chung, Wen Wei; Nor Azmi, Nuruljannah; Abdul Aziz, Siti Azdiah; Alwi, Syireen; Kamarulzaman, Adeeba; Kamaruzzaman, Shahrul Bahyah; Chua, Siew Siang; Rajasuriar, Reena

2017-01-01

Polypharmacy has been associated with increased morbidity and mortality in the older population. The aim of this study was to determine the prevalence, risk factors and health outcomes associated with polypharmacy in a cohort of urban community-dwelling older adults receiving chronic medications in Malaysia. This was a baseline study in the Malaysian Elders Longitudinal Research cohort. The inclusion criteria were individuals aged ≥55years and taking at least one medication chronically (≥3 months). Participants were interviewed using a structured questionnaire during home visits where medications taken were reviewed. Health outcomes assessed were frequency of falls, functional disability, potential inappropriate medication use (PIMs), potential drug-drug interactions (PDDIs), healthcare utilisation and quality of life (QoL). Risk factors and health outcomes associated with polypharmacy (≥5 medications including dietary supplements) were determined using multivariate regression models. A total of 1256 participants were included with a median (interquartile range) age of 69(63-74) years. The prevalence of polypharmacy was 45.9% while supplement users made up 56.9% of the cohort. The risk factors associated with increasing medication use were increasing age, Indian ethnicity, male, having a higher number of comorbidities specifically those diagnosed with cardiovascular, endocrine and gastrointestinal disorders, as well as supplement use. Health outcomes significantly associated with polypharmacy were PIMS, PDDIs and increased healthcare utilisation. A significant proportion of older adults on chronic medications were exposed to polypharmacy and use of dietary supplements contributed significantly to this. Medication reviews are warranted to reduce significant polypharmacy related issues in the older population.
Dual-Gate p-GaN Gate High Electron Mobility Transistors for Steep Subthreshold Slope.

PubMed

Bae, Jong-Ho; Lee, Jong-Ho

2016-05-01

A steep subthreshold slope characteristic is achieved through p-GaN gate HEMT with dual-gate structure. Obtained subthreshold slope is less than 120 μV/dec. Based on the measured and simulated data obtained from single-gate device, breakdown of parasitic floating-base bipolar transistor and floating gate charged with holes are responsible to increase abruptly in drain current. In the dual-gate device, on-current degrades with high temperature but subthreshold slope is not changed. To observe the switching speed of dual-gate device and transient response of drain current are measured. According to the transient responses of drain current, switching speed of the dual-gate device is about 10(-5) sec.
G4-FETs as Universal and Programmable Logic Gates

NASA Technical Reports Server (NTRS)

Johnson, Travis; Fijany, Amir; Mojarradi, Mohammad; Vatan, Farrokh; Toomarian, Nikzad; Kolawa, Elizabeth; Cristoloveanu, Sorin; Blalock, Benjamin

2007-01-01

An analysis of a patented generic silicon- on-insulator (SOI) electronic device called a G4-FET has revealed that the device could be designed to function as a universal and programmable logic gate. The universality and programmability could be exploited to design logic circuits containing fewer discrete components than are required for conventional transistor-based circuits performing the same logic functions. A G4-FET is a combination of a junction field-effect transistor (JFET) and a metal oxide/semiconductor field-effect transistor (MOSFET) superimposed in a single silicon island and can therefore be regarded as two transistors sharing the same body. A G4-FET can also be regarded as a single transistor having four gates: two side junction-based gates, a top MOS gate, and a back gate activated by biasing of the SOI substrate. Each of these gates can be used to control the conduction characteristics of the transistor; this possibility creates new options for designing analog, radio-frequency, mixed-signal, and digital circuitry. With proper choice of the specific dimensions for the gates, channels, and ancillary features of the generic G4-FET, the device could be made to function as a three-input, one-output logic gate. As illustrated by the truth table in the top part of the figure, the behavior of this logic gate would be the inverse (the NOT) of that of a majority gate. In other words, the device would function as a NOT-majority gate. By simply adding an inverter, one could obtain a majority gate. In contrast, to construct a majority gate in conventional complementary metal oxide/semiconductor (CMOS) circuitry, one would need four three-input AND gates and a four-input OR gate, altogether containing 32 transistors.
Comparison of gating methods for the real-time analysis of left ventricular function in nonimaging blood pool studies.

PubMed

Beard, B B; Stewart, J R; Shiavi, R G; Lorenz, C H

1995-01-01

Gating methods developed for electrocardiographic-triggered radionuclide ventriculography are being used with nonimaging detectors. These methods have not been compared on the basis of their real-time performance or suitability for determination of load-independent indexes of left ventricular function. This work evaluated the relative merits of different gating methods for nonimaging radionuclude ventriculographic studies, with particular emphasis on their suitability for real-time measurements and the determination of pressure-volume loops. A computer model was used to investigate the relative accuracy of forward gating, backward gating, and phase-mode gating. The durations of simulated left ventricular time-activity curves were randomly varied. Three acquisition parameters were considered: frame rate, acceptance window, and sample size. Twenty-five studies were performed for each combination of acquisition parameters. Hemodynamic and shape parameters from each study were compared with reference parameters derived directly from the random time-activity curves. Backward gating produced the largest errors under all conditions. For both forward gating and phase-mode gating, ejection fraction was underestimated and time to end systole and normalized peak ejection rate were overestimated. For the hemodynamic parameters, forward gating was marginally superior to phase-mode gating. The mean difference in errors between forward and phase-mode gating was 1.47% (SD 2.78%). However, for root mean square shape error, forward gating was several times worse in every case and seven times worse than phase-mode gating on average. Both forward and phase-mode gating are suitable for real-time hemodynamic measurements by nonimaging techniques. The small statistical difference between the methods is not clinically significant. The true shape of the time-activity curve is maintained most accurately by phase-mode gating.
Comparison of gating methods for the real-time analysis of left ventricular function in nonimaging blood pool studies

PubMed Central

Beard, Brian B.; Stewart, James R.; Shiavi, Richard G.; Lorenz, Christine H.

2018-01-01

Background Gating methods developed for electrocardiographic-triggered radionuclide ventriculography are being used with nonimaging detectors. These methods have not been compared on the basis of their real-time performance or suitability for determination of load-independent indexes of left ventricular function. This work evaluated the relative merits of different gating methods for nonimaging radionuclude ventriculographic studies, with particular emphasis on their suitability for real-time measurements and the determination of pressure-volume loops. Methods and Results A computer model was used to investigate the relative accuracy of forward gating, backward gating, and phase-mode gating. The durations of simulated left ventricular time-activity curves were randomly varied. Three acquisition parameters were considered: frame rate, acceptance window, and sample size. Twenty-five studies were performed for each combination of acquisition parameters. Hemodynamic and shape parameters from each study were compared with reference parameters derived directly from the random time-activity curves. Backward gating produced the largest errors under all conditions. For both forward gating and phase-mode gating, ejection fraction was underestimated and time to end systole and normalized peak ejection rate were overestimated. For the hemodynamic parameters, forward gating was marginally superior to phase-mode gating. The mean difference in errors between forward and phase-mode gating was 1.47% (SD 2.78%). However, for root mean square shape error, forward gating was several times worse in every case and seven times worse than phase-mode gating on average. Conclusions Both forward and phase-mode gating are suitable for real-time hemodynamic measurements by nonimaging techniques. The small statistical difference between the methods is not clinically significant. The true shape of the time-activity curve is maintained most accurately by phase-mode gating. PMID:9420820
Accuracy and Consistency of Respiratory Gating in Abdominal Cancer Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ge, Jiajia; Santanam, Lakshmi; Yang, Deshan

2013-03-01

Purpose: To evaluate respiratory gating accuracy and intrafractional consistency for abdominal cancer patients treated with respiratory gated treatment on a regular linear accelerator system. Methods and Materials: Twelve abdominal patients implanted with fiducials were treated with amplitude-based respiratory-gated radiation therapy. On the basis of daily orthogonal fluoroscopy, the operator readjusted the couch position and gating window such that the fiducial was within a setup margin (fiducial-planning target volume [f-PTV]) when RPM indicated “beam-ON.” Fifty-five pre- and post-treatment fluoroscopic movie pairs with synchronized respiratory gating signal were recorded. Fiducial motion traces were extracted from the fluoroscopic movies using a template matchingmore » algorithm and correlated with f-PTV by registering the digitally reconstructed radiographs with the fluoroscopic movies. Treatment was determined to be “accurate” if 50% of the fiducial area stayed within f-PTV while beam-ON. For movie pairs that lost gating accuracy, a MATLAB program was used to assess whether the gating window was optimized, the external-internal correlation (EIC) changed, or the patient moved between movies. A series of safety margins from 0.5 mm to 3 mm was added to f-PTV for reassessing gating accuracy. Results: A decrease in gating accuracy was observed in 44% of movie pairs from daily fluoroscopic movies of 12 abdominal patients. Three main causes for inaccurate gating were identified as change of global EIC over time (∼43%), suboptimal gating setup (∼37%), and imperfect EIC within movie (∼13%). Conclusions: Inconsistent respiratory gating accuracy may occur within 1 treatment session even with a daily adjusted gating window. To improve or maintain gating accuracy during treatment, we suggest using at least a 2.5-mm safety margin to account for gating and setup uncertainties.« less
Influence of gate width on gate-channel carrier mobility in AlGaN/GaN heterostructure field-effect transistors

NASA Astrophysics Data System (ADS)

Yang, Ming; Ji, Qizheng; Gao, Zhiliang; Zhang, Shufeng; Lin, Zhaojun; Yuan, Yafei; Song, Bo; Mei, Gaofeng; Lu, Ziwei; He, Jihao

2017-11-01

For the fabricated AlGaN/GaN heterostructure field-effect transistors (HFETs) with different gate widths, the gate-channel carrier mobility is experimentally obtained from the measured current-voltage and capacitance-voltage curves. Under each gate voltage, the mobility gets lower with gate width increasing. Analysis shows that the phenomenon results from the polarization Coulomb field (PCF) scattering, which originates from the irregularly distributed polarization charges at the AlGaN/GaN interface. The device with a larger gate width is with a larger PCF scattering potential and a stronger PCF scattering intensity. As a function of gate width, PCF scattering potential shows a same trend with the mobility variation. And the theoretically calculated mobility values fits well with the experimentally obtained values. Varying gate widths will be a new perspective for the improvement of device characteristics by modulating the gate-channel carrier mobility.
Iterated Gate Teleportation and Blind Quantum Computation.

PubMed

Pérez-Delgado, Carlos A; Fitzsimons, Joseph F

2015-06-05

Blind quantum computation allows a user to delegate a computation to an untrusted server while keeping the computation hidden. A number of recent works have sought to establish bounds on the communication requirements necessary to implement blind computation, and a bound based on the no-programming theorem of Nielsen and Chuang has emerged as a natural limiting factor. Here we show that this constraint only holds in limited scenarios, and show how to overcome it using a novel method of iterated gate teleportations. This technique enables drastic reductions in the communication required for distributed quantum protocols, extending beyond the blind computation setting. Applied to blind quantum computation, this technique offers significant efficiency improvements, and in some scenarios offers an exponential reduction in communication requirements.

Rectification of Acetylcholine-Elicited Currents in PC12 Pheochromocytoma Cells

NASA Astrophysics Data System (ADS)

Ifune, C. K.; Steinbach, J. H.

1990-06-01

The current-voltage (I-V) relationship for acetylcholine-elicited currents in the rat pheochromocytoma cell line PC12 is nonlinear. Two voltage-dependent processes that could account for the whole-cell current rectification were examined, receptor channel gating and single receptor channel permeation. We found that both factors are involved in the rectification of the whole-cell currents. The voltage dependence of channel gating determines the shape of the I-V curve at negative potentials. The single-channel I-V relationship is inwardly rectifying and largely responsible for the characteristic shape of the whole-cell I-V curve at positive potentials. The rectification of the single-channel currents is produced by the voltage-dependent block of outward currents by intracellular Mg2+ ions.
PhotoGate microscopy: tracking single molecules in a cytoplasm (Conference Presentation)

NASA Astrophysics Data System (ADS)

Yildiz, Ahmet

2016-02-01

Tracking single molecules inside cells reveals the dynamics of biological processes, including receptor trafficking, signaling and cargo transport. However, individual molecules often cannot be resolved inside cells due to their high density in the cellular environment. We developed a photobleaching gate assay, which controls the number of fluorescent particles in a region of interest by repeatedly photobleaching its boundary. Using this method, we tracked single particles at surface densities two orders of magnitude higher than the single-molecule detection limit. We observed ligand-induced dimerization of epidermal growth factor receptors (EGFR) on a live cell membrane. In addition, we tracked individual intraflagellar transport (IFT) trains along the length of a cilium and observed their remodeling at the ciliary tip.
Naphthacene Based Organic Thin Film Transistor With Rare Earth Oxide

NASA Astrophysics Data System (ADS)

Konwar, K.; Baishya, B.

2010-12-01

Naphthacene based organic thin film transistors (OTFTs) have been fabricated using La2O3, as the gate insulator. All the OTFTs have been fabricated by the process of thermal evaporation in vacuum on perfectly cleaned glass substrates with aluminium as source-drain and gate electrodes. The naphthacene film morphology on the glass substrate has been studied by XRD and found to be polycrystalline in nature. The field effect mobility, output resistance, amplification factor, transconductance and gain bandwidth product of the OTFTs have been calculated by using theoretical TFT model. The highest value of field effect mobility is found to be 0.07×10-3 cm2V-1s-1 for the devices annealed in vacuum at 90° C for 5 hours.
Respiratory motion management using audio-visual biofeedback for respiratory-gated radiotherapy of synchrotron-based pulsed heavy-ion beam delivery

PubMed Central

He, Pengbo; Li, Qiang; Liu, Xinguo; Dai, Zhongying; Zhao, Ting; Fu, Tingyan; Shen, Guosheng; Ma, Yuanyuan; Huang, Qiyan; Yan, Yuanlin

2014-01-01

Purpose: To efficiently deliver respiratory-gated radiation during synchrotron-based pulsed heavy-ion radiotherapy, a novel respiratory guidance method combining a personalized audio-visual biofeedback (BFB) system, breath hold (BH), and synchrotron-based gating was designed to help patients synchronize their respiratory patterns with synchrotron pulses and to overcome typical limitations such as low efficiency, residual motion, and discomfort. Methods: In-house software was developed to acquire body surface marker positions and display BFB, gating signals, and real-time beam profiles on a LED screen. Patients were prompted to perform short BHs or short deep breath holds (SDBH) with the aid of BFB following a personalized standard BH/SDBH (stBH/stSDBH) guiding curve or their own representative BH/SDBH (reBH/reSDBH) guiding curve. A practical simulation was performed for a group of 15 volunteers to evaluate the feasibility and effectiveness of this method. Effective dose rates (EDRs), mean absolute errors between the guiding curves and the measured curves, and mean absolute deviations of the measured curves were obtained within 10%–50% duty cycles (DCs) that were synchronized with the synchrotron’s flat-top phase. Results: All maneuvers for an individual volunteer took approximately half an hour, and no one experienced discomfort during the maneuvers. Using the respiratory guidance methods, the magnitude of residual motion was almost ten times less than during nongated irradiation, and increases in the average effective dose rate by factors of 2.39–4.65, 2.39–4.59, 1.73–3.50, and 1.73–3.55 for the stBH, reBH, stSDBH, and reSDBH guiding maneuvers, respectively, were observed in contrast with conventional free breathing-based gated irradiation, depending on the respiratory-gated duty cycle settings. Conclusions: The proposed respiratory guidance method with personalized BFB was confirmed to be feasible in a group of volunteers. Increased effective dose rate and improved overall treatment precision were observed compared to conventional free breathing-based, respiratory-gated irradiation. Because breathing guidance curves could be established based on the respective average respiratory period and amplitude for each patient, it may be easier for patients to cooperate using this technique. PMID:25370622
Monitoring and analysis of combined sewer overflows, Riverside and Evanston, Illinois, 1997-99

USGS Publications Warehouse

Waite, Andrew M.; Hornewer, Nancy J.; Johnson, Gary P.

2002-01-01

The U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, collected and analyzed flow data in combined sewer systems in Riverside and Evanston, northeastern Illinois, from March 1997 to December 1999. Continuous 2- and 5-minute stage and velocity data were collected during surcharged and nonsurcharged conditions at 12 locations. Mass balances were calculated to determine the volume of water flowing through the tide-gate openings to the Des Plaines River and the North Shore Channel and to determine the volume of water flowing past the sluice gate to the deep tunnel. The sewer systems consist of circular pipes ranging in diameter from 0.83 feet to 10.0 feet, elliptical siphon pipes, ledges, and tide and sluice gates. Pipes were constructed of either brick and mortar or concrete, and ranged from having smooth surfaces to rough, pitted and crumbling surfaces. One pipe was noticeably affected by water infiltration from saturated ground. During data analysis, many assumptions were necessary because of the complexity of the flow data and sewer-system configurations. These assumptions included estimating the volume of water entering an interceptor sewer at the ''Gage Street pipe'' at Riverside, the effect of infiltration on the ''brick pipe'' at Riverside, and the minimum velocity required for the meter to make an accurate velocity determination. Other factors affecting the analysis of flow data included possible non-instrumented sources of inflow, and backwater conditions in some pipes, which could have caused error in the data analysis. Variations of these assumptions potentially could cause appreciable changes to the final massbalance calculations. Mass-balance analysis at Riverside indicated a total inflow volume into chamber 3 of approximately 721,000 cubic feet (ft3) during April 22-26, 1999. Outflow volume to the Des Plaines River at Riverside through the tide gate was approximately 132,000 ft3; outflow volume to the deep tunnel through the sluice gate was approximately 267,000 ft3. The mass-balance analysis at Evanston indicated a total inflow volume into chamber 3 of approximately 5,970,000 ft3 during April 21-26, 1999. The outflow volume to the North Shore Channel through the tide gates at Evanston was approximately 2,920,000 ft3; outflow volume to the deep tunnel through the sluice gates was approximately 3,050,000 ft3.
Investigating compositional effects of atomic layer deposition ternary dielectric Ti-Al-O on metal-insulator-semiconductor heterojunction capacitor structure for gate insulation of InAlN/GaN and AlGaN/GaN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colon, Albert; Stan, Liliana; Divan, Ralu

Gate insulation/surface passivation in AlGaN/GaN and InAlN/GaN heterojunction field-effect transistors is a major concern for passivation of surface traps and reduction of gate leakage current. However, finding the most appropriate gate dielectric materials is challenging and often involves a compromise of the required properties such as dielectric constant, conduction/valence band-offsets, or thermal stability. Creating a ternary compound such as Ti-Al-O and tailoring its composition may result in a reasonably good gate material in terms of the said properties. To date, there is limited knowledge of the performance of ternary dielectric compounds on AlGaN/GaN and even less on InAlN/GaN. To approachmore » this problem, the authors fabricated metal-insulator-semiconductor heterojunction (MISH) capacitors with ternary dielectrics Ti-Al-O of various compositions, deposited by atomic layer deposition (ALD). The film deposition was achieved by alternating cycles of TiO2 and Al2O3 using different ratios of ALD cycles. TiO2 was also deposited as a reference sample. The electrical characterization of the MISH capacitors shows an overall better performance of ternary compounds compared to the pure TiO2. The gate leakage current density decreases with increasing Al content, being similar to 2-3 orders of magnitude lower for a TiO2:Al2O3 cycle ratio of 2:1. Although the dielectric constant has the highest value of 79 for TiO2 and decreases with increasing the number of Al2O3 cycles, it is maintaining a relatively high value compared to an Al2O3 film. Capacitance voltage sweeps were also measured in order to characterize the interface trap density. A decreasing trend in the interface trap density was found while increasing Al content in the film. In conclusion, our study reveals that the desired high-kappa properties of TiO2 can be adequately maintained while improving other insulator performance factors. The ternary compounds may be an excellent choice as a gate material for both AlGaN/GaN and InAlN/GaN based devices.« less
Respiratory motion management using audio-visual biofeedback for respiratory-gated radiotherapy of synchrotron-based pulsed heavy-ion beam delivery

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, Pengbo; Ma, Yuanyuan; Huang, Qiyan

Purpose: To efficiently deliver respiratory-gated radiation during synchrotron-based pulsed heavy-ion radiotherapy, a novel respiratory guidance method combining a personalized audio-visual biofeedback (BFB) system, breath hold (BH), and synchrotron-based gating was designed to help patients synchronize their respiratory patterns with synchrotron pulses and to overcome typical limitations such as low efficiency, residual motion, and discomfort. Methods: In-house software was developed to acquire body surface marker positions and display BFB, gating signals, and real-time beam profiles on a LED screen. Patients were prompted to perform short BHs or short deep breath holds (SDBH) with the aid of BFB following a personalized standardmore » BH/SDBH (stBH/stSDBH) guiding curve or their own representative BH/SDBH (reBH/reSDBH) guiding curve. A practical simulation was performed for a group of 15 volunteers to evaluate the feasibility and effectiveness of this method. Effective dose rates (EDRs), mean absolute errors between the guiding curves and the measured curves, and mean absolute deviations of the measured curves were obtained within 10%–50% duty cycles (DCs) that were synchronized with the synchrotron’s flat-top phase. Results: All maneuvers for an individual volunteer took approximately half an hour, and no one experienced discomfort during the maneuvers. Using the respiratory guidance methods, the magnitude of residual motion was almost ten times less than during nongated irradiation, and increases in the average effective dose rate by factors of 2.39–4.65, 2.39–4.59, 1.73–3.50, and 1.73–3.55 for the stBH, reBH, stSDBH, and reSDBH guiding maneuvers, respectively, were observed in contrast with conventional free breathing-based gated irradiation, depending on the respiratory-gated duty cycle settings. Conclusions: The proposed respiratory guidance method with personalized BFB was confirmed to be feasible in a group of volunteers. Increased effective dose rate and improved overall treatment precision were observed compared to conventional free breathing-based, respiratory-gated irradiation. Because breathing guidance curves could be established based on the respective average respiratory period and amplitude for each patient, it may be easier for patients to cooperate using this technique.« less
Respiratory gating based on internal electromagnetic motion monitoring during stereotactic liver radiation therapy: First results.

PubMed

Poulsen, Per Rugaard; Worm, Esben Schjødt; Hansen, Rune; Larsen, Lars Peter; Grau, Cai; Høyer, Morten

2015-01-01

Intrafraction motion may compromise the target dose in stereotactic body radiation therapy (SBRT) of tumors in the liver. Respiratory gating can improve the treatment delivery, but gating based on an external surrogate signal may be inaccurate. This is the first paper reporting on respiratory gating based on internal electromagnetic monitoring during liver SBRT. Two patients with solitary liver metastases were treated with respiratory-gated SBRT guided by three implanted electromagnetic transponders. The treatment was delivered in end-exhale with beam-on when the centroid of the three transponders deviated less than 3 mm [left-right (LR) and anterior-posterior (AP) directions] and 4mm [cranio-caudal (CC)] from the planned position. For each treatment fraction, log files were used to determine the transponder motion during beam-on in the actual gated treatments and in simulated treatments without gating. The motion was used to reconstruct the dose to the clinical target volume (CTV) with and without gating. The reduction in D95 (minimum dose to 95% of the CTV) relative to the plan was calculated for both treatment courses. With gating the maximum course mean (standard deviation) geometrical error in any direction was 1.2 mm (1.8 mm). Without gating the course mean error would mainly increase for Patient 1 [to -2.8 mm (1.6 mm) (LR), 7.1 mm (5.8 mm) (CC), -2.6 mm (2.8mm) (AP)] due to a large systematic cranial baseline drift at each fraction. The errors without gating increased only slightly for Patient 2. The reduction in CTV D95 was 0.5% (gating) and 12.1% (non-gating) for Patient 1 and 0.3% (gating) and 1.7% (non-gating) for Patient 2. The mean duty cycle was 55%. Respiratory gating based on internal electromagnetic motion monitoring was performed for two liver SBRT patients. The gating added robustness to the dose delivery and ensured a high CTV dose even in the presence of large intrafraction motion.
Reading Gate Positions with a Smartphone

NASA Astrophysics Data System (ADS)

van Overloop, Peter-Jules; Hut, Rolf

2015-04-01

Worldwide many flow gates are built in water networks in order to direct water to appropriate locations. Most of these gates are adjusted manually by field operators of water management organizations and it is often centrally not known what the new position of the gate is. This makes centralized management of the entire water network difficult. One of the reasons why the measurement of the gate position is usually not executed, is that for certain gates it is not easy to do such a reading. Tilting weirs or radial gates are examples where operators need special equipment (measuring rod and long level) to determine the position and it could even be a risky procedure. Another issue is that once the measurement is done, the value is jotted down in a notebook and later, at the office, entered in a computer system. So the entire monitoring procedure is not real-time and prone to human errors. A new way of monitoring gate positions is introduced. It consists of a level that is attached to the gate and an app with which a picture can be taken from the level. Using dedicated pattern recognition algorithms, the gate position can be read by using the angle of the level versus reference points on the gate, the radius of that gate and the absolute level of the joint around which the gate turn. The method uses gps-localization of the smartphone to store the gate position in the right location in the central database.
Health service utilisation amongst urban Aboriginal and Torres Strait Islander children aged younger than 5 years registered with a primary health-care service in South-East Queensland.

PubMed

Hall, Kerry K; Chang, Anne B; Anderson, Jennie; Arnold, Daniel; Otim, Michael; O'Grady, Kerry-Ann F

2018-06-01

The majority of Australia's Aboriginal and/or Torres Strait Islander children live in urban areas; however, little is known about their health service use. We aimed to describe health service utilisation amongst a cohort of urban Aboriginal and/or Torres Strait Islander children aged <5 years. We analysed health service utilisation data collected in an ongoing prospective cohort study of children aged <5 years registered with an Aboriginal-owned and operated primary health-care service. Enrolled children were followed monthly for 12 months, with data on health service utilisation collected at baseline and at each monthly follow-up. Health service utilisation rates, overall and by service provider and reason for presentation, were calculated and reported as incidence rates per 100 child-months with the corresponding 95% confidence intervals (CIs). Between February 2013 and November 2015, 180 children were enrolled, and 1541 child-months of observation were available for analysis. The overall incidence of health service utilisation was 52.5 per 100 child-months (95% CI 48.7-56.5); 81% of encounters were with general practitioners. Presentation rates were the highest for acute respiratory illnesses (30.7/100 child-months, 95% CI 27.8-33.9). In this community, acute respiratory illnesses are predominant causes of health service utilisation in young children. The health-care utilisation profile of these children presents important opportunities for health promotion and intervention. © 2018 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).
The experiences of culturally and linguistically diverse family caregivers in utilising dementia services in Australia

PubMed Central

2013-01-01

Background Older people from culturally and linguistically diverse groups are underrepresented in residential aged care but overrepresented in community aged care in Australia. However, little is known about culturally and linguistically diverse family caregivers in utilising dementia services in Australia because previous studies mainly focused on the majority cultural group. Experiences of caregivers from culturally and linguistically diverse groups who are eligible to utilise dementia services in Australia are needed in order to optimize the utilisation of dementia services for these caregivers. Methods The aim of the study was to explore the experiences of family caregivers from Chinese, Greek, Italian and Vietnamese groups in utilising dementia services. Gadamer's philosophical hermeneutics was used to interpret the experiences of the participants. Focus group discussions and in-depth individual interviews were used to collect data. Data collection was conducted over a six month period in 2011. In total, 46 family caregivers who were caring for 39 persons with dementia participated. Results Four themes were revealed: (1) negotiating services for the person with dementia; (2) the impact of acculturation on service utilisation; (3) the characteristics of satisfactory services; and (4) negative experiences in utilising services. The present study revealed that the participation of caregivers from culturally and linguistically diverse groups in planning and managing dementia services ranged markedly from limited participation to full participation. Conclusions The findings of this study suggest that caregivers from culturally and linguistically diverse groups need to be fully prepared so they can participate in the utilisation of dementia services available to them in Australia. PMID:24148155
The experiences of culturally and linguistically diverse family caregivers in utilising dementia services in Australia.

PubMed

Xiao, Lily Dongxia; De Bellis, Anita; Habel, Lesley; Kyriazopoulos, Helena

2013-10-22

Older people from culturally and linguistically diverse groups are underrepresented in residential aged care but overrepresented in community aged care in Australia. However, little is known about culturally and linguistically diverse family caregivers in utilising dementia services in Australia because previous studies mainly focused on the majority cultural group. Experiences of caregivers from culturally and linguistically diverse groups who are eligible to utilise dementia services in Australia are needed in order to optimize the utilisation of dementia services for these caregivers. The aim of the study was to explore the experiences of family caregivers from Chinese, Greek, Italian and Vietnamese groups in utilising dementia services. Gadamer's philosophical hermeneutics was used to interpret the experiences of the participants. Focus group discussions and in-depth individual interviews were used to collect data. Data collection was conducted over a six month period in 2011. In total, 46 family caregivers who were caring for 39 persons with dementia participated. Four themes were revealed: (1) negotiating services for the person with dementia; (2) the impact of acculturation on service utilisation; (3) the characteristics of satisfactory services; and (4) negative experiences in utilising services. The present study revealed that the participation of caregivers from culturally and linguistically diverse groups in planning and managing dementia services ranged markedly from limited participation to full participation. The findings of this study suggest that caregivers from culturally and linguistically diverse groups need to be fully prepared so they can participate in the utilisation of dementia services available to them in Australia.
Researchers at the Gate: Factors Influencing Districts' Right of Entry Decisions

ERIC Educational Resources Information Center

Melnick, Steven A.; Henk, William A.

2006-01-01

Background: The No Child Left Behind legislation creates an increased need for new school-based empirical studies whose implementation will depend largely on researchers' access to various school populations and records. Access decisions are typically made by superintendents, or their designees, functioning as gatekeepers who control right of…
Cross Cultural Perspectives of Gender and Management in Universities

ERIC Educational Resources Information Center

White, K.; Riordan, S.; Ozkanli, O.; Neale, J.

2010-01-01

Aim: This article presents preliminary results of a cross cultural study of gender and management in universities. Methodology: Qualitative interviews with senior managers in each country were analysed in relation to key concepts of career paths, support, gate keeping, management skills, disciplinary factors, gendered leadership styles and…
High-fidelity gates in quantum dot spin qubits

PubMed Central

Koh, Teck Seng; Coppersmith, S. N.; Friesen, Mark

2013-01-01

Several logical qubits and quantum gates have been proposed for semiconductor quantum dots controlled by voltages applied to top gates. The different schemes can be difficult to compare meaningfully. Here we develop a theoretical framework to evaluate disparate qubit-gating schemes on an equal footing. We apply the procedure to two types of double-dot qubits: the singlet–triplet and the semiconducting quantum dot hybrid qubit. We investigate three quantum gates that flip the qubit state: a DC pulsed gate, an AC gate based on logical qubit resonance, and a gate-like process known as stimulated Raman adiabatic passage. These gates are all mediated by an exchange interaction that is controlled experimentally using the interdot tunnel coupling g and the detuning ϵ, which sets the energy difference between the dots. Our procedure has two steps. First, we optimize the gate fidelity (f) for fixed g as a function of the other control parameters; this yields an that is universal for different types of gates. Next, we identify physical constraints on the control parameters; this yields an upper bound that is specific to the qubit-gate combination. We show that similar gate fidelities should be attainable for singlet-triplet qubits in isotopically purified Si, and for hybrid qubits in natural Si. Considerably lower fidelities are obtained for GaAs devices, due to the fluctuating magnetic fields ΔB produced by nuclear spins. PMID:24255105
SU-E-T-439: Fundamental Verification of Respiratory-Gated Spot Scanning Proton Beam Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamano, H; Yamakawa, T; Hayashi, N

Purpose: The spot-scanning proton beam irradiation with respiratory gating technique provides quite well dose distribution and requires both dosimetric and geometric verification prior to clinical implementation. The purpose of this study is to evaluate the impact of gating irradiation as a fundamental verification. Methods: We evaluated field width, flatness, symmetry, and penumbra in the gated and non-gated proton beams. The respiration motion was distinguished into 3 patterns: 10, 20, and 30 mm. We compared these contents between the gated and non-gated beams. A 200 MeV proton beam from PROBEAT-III unit (Hitachi Co.Ltd) was used in this study. Respiratory gating irradiationmore » was performed by Quasar phantom (MODUS medical devices) with a combination of dedicated respiratory gating system (ANZAI Medical Corporation). For radiochromic film dosimetry, the calibration curve was created with Gafchromic EBT3 film (Ashland) on FilmQA Pro 2014 (Ashland) as film analysis software. Results: The film was calibrated at the middle of spread out Bragg peak in passive proton beam. The field width, flatness and penumbra in non-gated proton irradiation with respiratory motion were larger than those of reference beam without respiratory motion: the maximum errors of the field width, flatness and penumbra in respiratory motion of 30 mm were 1.75% and 40.3% and 39.7%, respectively. The errors of flatness and penumbra in gating beam (motion: 30 mm, gating rate: 25%) were 0.0% and 2.91%, respectively. The results of symmetry in all proton beams with gating technique were within 0.6%. Conclusion: The field width, flatness, symmetry and penumbra were improved with the gating technique in proton beam. The spot scanning proton beam with gating technique is feasible for the motioned target.« less
Unifying Gate Synthesis and Magic State Distillation.

PubMed

Campbell, Earl T; Howard, Mark

2017-02-10

The leading paradigm for performing a computation on quantum memories can be encapsulated as distill-then-synthesize. Initially, one performs several rounds of distillation to create high-fidelity magic states that provide one good T gate, an essential quantum logic gate. Subsequently, gate synthesis intersperses many T gates with Clifford gates to realize a desired circuit. We introduce a unified framework that implements one round of distillation and multiquibit gate synthesis in a single step. Typically, our method uses the same number of T gates as conventional synthesis but with the added benefit of quadratic error suppression. Because of this, one less round of magic state distillation needs to be performed, leading to significant resource savings.
Quantum computing gates via optimal control

NASA Astrophysics Data System (ADS)

Atia, Yosi; Elias, Yuval; Mor, Tal; Weinstein, Yossi

2014-10-01

We demonstrate the use of optimal control to design two entropy-manipulating quantum gates which are more complex than the corresponding, commonly used, gates, such as CNOT and Toffoli (CCNOT): A two-qubit gate called polarization exchange (PE) and a three-qubit gate called polarization compression (COMP) were designed using GRAPE, an optimal control algorithm. Both gates were designed for a three-spin system. Our design provided efficient and robust nuclear magnetic resonance (NMR) radio frequency (RF) pulses for 13C2-trichloroethylene (TCE), our chosen three-spin system. We then experimentally applied these two quantum gates onto TCE at the NMR lab. Such design of these gates and others could be relevant for near-future applications of quantum computing devices.
Simulation and video animation of canal flushing created by a tide gate

USGS Publications Warehouse

Schoellhamer, David H.

1988-01-01

A tide-gate algorithm was added to a one-dimensional unsteady flow model that was calibrated, verified, and used to determine the locations of as many as five tide gates that would maximize flushing in two canal systems. Results from the flow model were used to run a branched Lagrangian transport model to simulate the flushing of a conservative constituent from the canal systems both with and without tide gates. A tide gate produces a part-time riverine flow through the canal system that improves flushing along the flow path created by the tide gate. Flushing with no tide gates and with a single optimally located tide gate are shown with a video animation.
Utilisation of a community-based health facility in a low-income urban community in Ibadan, Nigeria

PubMed Central

Asuzu, Michael C.

2015-01-01

Background Primary healthcare is established to ensure that people have access to health services through facilities located in their community. However, utilisation of health facilities in Nigeria remains low in many communities. Aim To assess the utilisation of community-based health facility (CBHF) amongst adults in Ibadan, Nigeria Settings A low-income community in Ibadan North West Local Government Area of Oyo State. Methods A cross-sectional survey was conducted using a simple random sampling technique to select one adult per household in all 586 houses in the community. A semi-structured interviewer-administered questionnaire was used to collect information on respondents' sociodemographic characteristics, knowledge and utilisation of the CBHF. Data analysis included descriptive statistics and association testing using the Chi-square test at p = 0.05. Results The mean age of the respondents was 46.5 ± 16.0 years; 46.0% were men and 81.0% married; 26% had no formal education and 38.0% had secondary-level education and above; traders constituted 52.0% of the sample; and 85.2% were of low socioeconomic standing; 90% had patronised the CBHF. The main reasons for non-utilisation were preference for general hospitals (13.8%) and self-medication (12.1%). Respondents who had secondary education and above, were in a higher socioeconomic class, who had good knowledge of the facility and were satisfied with care, utilised the CBHF three months significantly more than their counterparts prior to the study (p < 0.05). However, only satisfaction with care was found to be a significant predictor of utilisation of the CBHF. Conclusion The utilisation of the CBHF amongst adults in the study setting is high, driven mostly by satisfaction with the care received previously. Self-medication, promoted by uncontrolled access to drugs through pharmacies and patent medicine stores, threatens this high utilisation. PMID:26245600

Side-gate modulation effects on high-quality BN-Graphene-BN nanoribbon capacitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yang; Chen, Xiaolong; Ye, Weiguang

High-quality BN-Graphene-BN nanoribbon capacitors with double side-gates of graphene have been experimentally realized. The double side-gates can effectively modulate the electronic properties of graphene nanoribbon capacitors. By applying anti-symmetric side-gate voltages, we observed significant upward shifting and flattening of the V-shaped capacitance curve near the charge neutrality point. Symmetric side-gate voltages, however, only resulted in tilted upward shifting along the opposite direction of applied gate voltages. These modulation effects followed the behavior of graphene nanoribbons predicted theoretically for metallic side-gate modulation. The negative quantum capacitance phenomenon predicted by numerical simulations for graphene nanoribbons modulated by graphene side-gates was not observed,more » possibly due to the weakened interactions between the graphene nanoribbon and side-gate electrodes caused by the Ga{sup +} beam etching process.« less
Extraction of the gate capacitance coupling coefficient in floating gate non-volatile memories: Statistical study of the effect of mismatching between floating gate memory and reference transistor in dummy cell extraction methods

NASA Astrophysics Data System (ADS)

Rafhay, Quentin; Beug, M. Florian; Duane, Russell

2007-04-01

This paper presents an experimental comparison of dummy cell extraction methods of the gate capacitance coupling coefficient for floating gate non-volatile memory structures from different geometries and technologies. These results show the significant influence of mismatching floating gate devices and reference transistors on the extraction of the gate capacitance coupling coefficient. In addition, it demonstrates the accuracy of the new bulk bias dummy cell extraction method and the importance of the β function, introduced recently in [Duane R, Beug F, Mathewson A. Novel capacitance coupling coefficient measurement methodology for floating gate non-volatile memory devices. IEEE Electr Dev Lett 2005;26(7):507-9], to determine matching pairs of floating gate memory and reference transistor.
Gate sequence for continuous variable one-way quantum computation

PubMed Central

Su, Xiaolong; Hao, Shuhong; Deng, Xiaowei; Ma, Lingyu; Wang, Meihong; Jia, Xiaojun; Xie, Changde; Peng, Kunchi

2013-01-01

Measurement-based one-way quantum computation using cluster states as resources provides an efficient model to perform computation and information processing of quantum codes. Arbitrary Gaussian quantum computation can be implemented sufficiently by long single-mode and two-mode gate sequences. However, continuous variable gate sequences have not been realized so far due to an absence of cluster states larger than four submodes. Here we present the first continuous variable gate sequence consisting of a single-mode squeezing gate and a two-mode controlled-phase gate based on a six-mode cluster state. The quantum property of this gate sequence is confirmed by the fidelities and the quantum entanglement of two output modes, which depend on both the squeezing and controlled-phase gates. The experiment demonstrates the feasibility of implementing Gaussian quantum computation by means of accessible gate sequences.
Topologically protected gates for quantum computation with non-Abelian anyons in the Pfaffian quantum Hall state

NASA Astrophysics Data System (ADS)

Georgiev, Lachezar S.

2006-12-01

We extend the topological quantum computation scheme using the Pfaffian quantum Hall state, which has been recently proposed by Das Sarma , in a way that might potentially allow for the topologically protected construction of a universal set of quantum gates. We construct, for the first time, a topologically protected controlled-NOT gate, which is entirely based on quasihole braidings of Pfaffian qubits. All single-qubit gates, except for the π/8 gate, are also explicitly implemented by quasihole braidings. Instead of the π/8 gate we try to construct a topologically protected Toffoli gate, in terms of the controlled-phase gate and CNOT or by a braid-group-based controlled-controlled- Z precursor. We also give a topologically protected realization of the Bravyi-Kitaev two-qubit gate g3 .
"Be kind to young people so they feel at home": a qualitative study of adolescents' and service providers' perceptions of youth-friendly sexual and reproductive health services in Vanuatu.

PubMed

Kennedy, Elissa C; Bulu, Siula; Harris, Jennifer; Humphreys, David; Malverus, Jayline; Gray, Natalie J

2013-10-31

Sexual activity during adolescence is common in Vanuatu, however many adolescents lack access to sexual and reproductive health (SRH) services and subsequently suffer a disproportionate burden of poor SRH. There is limited peer-reviewed research describing adolescents' SRH service delivery preferences in Vanuatu to inform policy and programs. The aim of this qualitative study was to explore the barriers preventing adolescents from accessing SRH services in Vanuatu and the features of a youth-friendly health service as defined by adolescents. Sixty-six focus group discussions were conducted with 341 male and female adolescents aged 15-19 years in rural and urban communities. Additionally, 12 semi-structured interviews were undertaken with policymakers and service providers. Data were analysed using thematic analysis. Socio-cultural norms and taboos regarding adolescent sexual behaviour were the most significant factors preventing adolescents from accessing services. These contributed to adolescents' own fear and shame, judgmental attitudes of service providers, and disapproval from parents and community gate-keepers. Lack of confidentiality and privacy, costs, and adolescents' lack of SRH knowledge were also important barriers. Adolescents and service providers identified opportunities to make existing services more youth-friendly. The most important feature of a youth-friendly health service described by adolescents was a friendly service provider. Free or affordable services, reliable commodity supply, confidentiality and privacy were also key features. The need to address socio-cultural norms and community knowledge and attitudes was also highlighted. There are significant demand and supply-side barriers contributing to low utilisation of SRH services by adolescents in Vanuatu. However, there are many opportunities to make existing SRH services more youth-friendly, such as improving service provider training. Investment is also required in strategies that aim to create a more supportive environment for adolescent SRH.
Determinants of Skilled Delivery Assistance in a Rural Population: Findings from an HDSS Site of Rural West Bengal, India.

PubMed

Ghosh, Saswata; Siddiqui, Md Zakaria; Barik, Anamitra; Bhaumik, Sunil

2015-11-01

This study examines the determinants of utilisation of skilled birth attendants (SBAs) amongst 2886 rural women in the state of West Bengal, India, using data from a survey of 2012-2013 conducted by the Birbhum Health and Demographic Surveillance System. Multilevel logit regression models were estimated and qualitative investigations conducted to understand the determinants of utilisation of SBAs in rural West Bengal. Among women who delivered their last child during the 3 years preceding the survey, 69.1 % of deliveries were assisted by SBAs, while 30.9 % were home deliveries without any SBA assistance. Multivariate analysis revealed that apart from socio-demographic and economic factors (such as household affluence, women's education, birth order, uptake of comprehensive ANC check-ups, advice regarding danger signs of pregnancy and household's socio-religious affiliation), supply side factors, such as availability of skilled birth attendants in the village and all-weather roads, have significant effect on seeking skilled assistance. Our findings also show that unobserved factors at village level independently influence uptake of SBA-assisted delivery. The present findings emphasise that both demand and supply side intervention strategies are essential prerequisites to enhance skilled birth attendance. Ample communication is observed at the individual level, but improving community level outreach and advocacy activities could generate further demand. SBAs can be better integrated by accommodating the socio-religious needs of local communities, such as providing female doctors and doctors with similar socio-religious backgrounds.
Use of Online Machine Translation for Nursing Literature: A Questionnaire-Based Survey

PubMed Central

Anazawa, Ryoko; Ishikawa, Hirono; Takahiro, Kiuchi

2013-01-01

Background: The language barrier is a significant obstacle for nurses who are not native English speakers to obtain information from international journals. Freely accessible online machine translation (MT) offers a possible solution to this problem. Aim: To explore how Japanese nursing professionals use online MT and perceive its usability in reading English articles and to discuss what should be considered for better utilisation of online MT lessening the language barrier. Method: In total, 250 randomly selected assistants and research associates at nursing colleges across Japan answered a questionnaire examining the current use of online MT and perceived usability among Japanese nurses, along with the number of articles read in English and the perceived language barrier. The items were rated on Likert scales, and t-test, ANOVA, chi-square test, and Spearman’s correlation were used for analyses. Results: Of the participants, 73.8% had used online MT. More than half of them felt it was usable. The language barrier was strongly felt, and academic degrees and English proficiency level were associated factors. The perceived language barrier was related to the frequency of online MT use. No associated factor was found for the perceived usability of online MT. Conclusion: Language proficiency is an important factor for optimum utilisation of MT. A need for education in the English language, reading scientific papers, and online MT training was indicated. Cooperation with developers and providers of MT for the improvement of their systems is required. PMID:23459140
A high-efficiency HPGe coincidence system for environmental analysis.

PubMed

Britton, R; Davies, A V; Burnett, J L; Jackson, M J

2015-08-01

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is supported by a network of certified laboratories which must meet certain sensitivity requirements for CTBT relevant radionuclides. At the UK CTBT Radionuclide Laboratory (GBL15), a high-efficiency, dual-detector gamma spectroscopy system has been developed to improve the sensitivity of measurements for treaty compliance, greatly reducing the time required for each sample. Utilising list-mode acquisition, each sample can be counted once, and processed multiple times to further improve sensitivity. For the 8 key radionuclides considered, Minimum Detectable Activities (MDA's) were improved by up to 37% in standard mode (when compared to a typical CTBT detector system), with the acquisition time required to achieve the CTBT sensitivity requirements reduced from 6 days to only 3. When utilising the system in coincidence mode, the MDA for (60) Co in a high-activity source was improved by a factor of 34 when compared to a standard CTBT detector, and a factor of 17 when compared to the dual-detector system operating in standard mode. These MDA improvements will allow the accurate and timely quantification of radionuclides that decay via both singular and cascade γ emission, greatly enhancing the effectiveness of CTBT laboratories. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.
Effect of top gate potential on bias-stress for dual gate amorphous indium-gallium-zinc-oxide thin film transistor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chun, Minkyu; Um, Jae Gwang; Park, Min Sang

We report the abnormal behavior of the threshold voltage (V{sub TH}) shift under positive bias Temperature stress (PBTS) and negative bias temperature stress (NBTS) at top/bottom gate in dual gate amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs). It is found that the PBTS at top gate shows negative transfer shift and NBTS shows positive transfer shift for both top and bottom gate sweep. The shift of bottom/top gate sweep is dominated by top gate bias (V{sub TG}), while bottom gate bias (V{sub BG}) is less effect than V{sub TG}. The X-ray photoelectron spectroscopy (XPS) depth profile provides the evidence of Inmore » metal diffusion to the top SiO{sub 2}/a-IGZO and also the existence of large amount of In{sup +} under positive top gate bias around top interfaces, thus negative transfer shift is observed. On the other hand, the formation of OH{sup −} at top interfaces under the stress of negative top gate bias shows negative transfer shift. The domination of V{sub TG} both on bottom/top gate sweep after PBTS/NBTS is obviously occurred due to thin active layer.« less
A Closely Coupled Experimental and Numerical Approach for Hypersonic and High Enthalpy Flow Investigations Utilising the HEG Shock Tunnel and the DLR TAU Code

DTIC Science & Technology

2010-04-01

factorization scheme (Lower-Upper Symmetric Gauss- Seidel ) can be used for time integration. Additional convergence acceleration is achieved by the...of the full Stefan -Maxwell equations. The diffusive mass flux of species S is computed according to: for 1 for jS S S Sm j jm S j eS jd S S S j j j...approximate factorization scheme (Lower-Upper Symmetric Gauss- Seidel ). For steady state problems, equation (69) reduces to R=0 because ddU t
Utilization of physiotherapy in the continuum of stroke care at a tertiary hospital in Ibadan, Nigeria.

PubMed

Olaleye, Olubukola Adebisi; Lawal, Zainab Iyabo

2017-03-01

To investigate the pattern of referral for and utilisation of physiotherapy in the continuum of stroke care at a tertiary hospital in Ibadan, Nigeria. Referral notes and medical records of patients admitted in the University College Hospital, Ibadan with a clinical diagnosis of stroke between January, 2009 and December, 2013 were retrospectively reviewed. Information on age, sex, type of stroke, length of hospital stay, referral for physiotherapy and utilisation of physiotherapy were retrieved. Data were summarised using descriptive statistics and analysed using Chi-square test. A total of 783 patients with stroke were admitted in the hospital during the period under study. The in-patient mortality rate was 37.2%. The mean Length of Hospital Stay (LoHS) was 16.17±12.34 days. Referral rate for physiotherapy was high (75.8%) and the mean time from admission to referral for physiotherapy was three days. Majority of patients referred utilised physiotherapy (63.4%) and mean number of physiotherapy sessions received during in-patient care was 8.69±6.45. There was a significant association between LoHS and utilisation of in-patientphysiotherapy (p=0.02). The referral rate of stroke patients for physiotherapy was relatively high. Utilisation of in-patient physiotherapy reduced length of hospital stay among patients with stroke. Utilisation of out-patient physiotherapy was low. Strategies to enhance out-patient utilisation should be explored.
SU-C-210-03: Impact of Breathing Irregularities On Gated Treatments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schiuma, D; Arheit, M; Schmelzer, P

2015-06-15

Purpose: To evaluate the effect of breathing irregularities on target location in gated treatments using amplitude and phase gating. Methods: 111 breathing patterns acquired using RPM system were categorized based on period and amplitude STD as regular (STD period ≤ 0.5 s, STD amplitude ≤ 1.5 mm), medium (0.5 s < STD period ≤ 1 s, 1.5 mm < STD amplitude ≤ 3 mm) and irregular (STD period > 1 s, STD amplitude > 3 mm). One pattern representative of the average defined population was selected per category and corresponding target motion reproduced using Quasar Respiratory Motion Phantom. Phantom inmore » motion underwent 4D-CT scan with phase reconstruction. Gated window was defined at end of exhale and DRRs reconstructed in treatment planning at 40% (beam on) and 60% phase (beam off). Target location uncertainty was assessed by comparing gated kV triggered images continuously acquired at beam on/off on a True Beam 2.0 with corresponding DRRs. Results: Average target uncertainty with amplitude gating was in [0.4 – 1.9] mm range for the different scenarios with maximum STD of 1.2 mm for the irregular pattern. Average target uncertainty with phase gating was [1.1 – 2.2] mm for regular and medium patterns, while it increased to [3.6 – 9.6] mm for the irregular pattern. Live gated motion was stable with amplitude gating, while increasing with phase gating for the irregular pattern. Treatment duration range was [68 – 160] s with amplitude and [70 – 74] s with phase gating. Conclusion: Breathing irregularities were found to affect gated treatments only when using phase gating. For regular and medium patterns no significant difference was found between the two gating strategies. Amplitude gating ensured stable gated motion within the different patterns, thus reducing intra-fraction target location variability for the irregular pattern and resulting in longer treatment duration.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)

Jermoumi, M; Cao, D; Housley, D

Purpose: In this study, we evaluated the performance of an Elekta linac in the delivery of gated radiotherapy. We examined whether the use of either a short gating window or a long beam hold impacts the accuracy of the delivery Methods: The performance of an Elekta linac in the delivery of gated radiotherapy was assessed using a 20cmX 20cm open field with the radiation delivered using a range of beam-on and beam-off time periods. Two SBRT plans were used to examine the accuracy of gated beam delivery for clinical treatment plans. For the SBRT cases, tests were performed for bothmore » free-breathing based gating and for gated delivery with a simulated breath-hold. A MatriXX 2D ion chamber array was used for data collection, and the gating accuracy was evaluated using gamma score. Results: For the 20cmX20cm open field, the gated beam delivery agreed closely with the non-gated delivery results. Discrepancies in the agreement, however, began to appear with a 5-to-1 ratio of the beam-off to beam-on. For these tight gating windows, each beam-on segment delivered a small number of monitor units. This finding was confirmed with dose distribution analysis from the delivery of the two VMAT plans where the gamma score(±1%,2%/1mm) showed passing rates in the range of 95% to 100% for gating windows of 25%, 38%, 50%, 63%, 75%, and 83%. Using a simulated sinusoidal breathing signal with a 4 second period, the gamma score of freebreathing gating and breath-hold gating deliveries were measured in the range of 95.7% to 100%. Conclusion: The results demonstrate that Elekta linacs can be used to accurately deliver respiratory gated treatments for both free-breathing and breath-hold patients. The accuracy of beams delivered in a gated delivery mode at low small MU proved higher than similar deliveries performed in a non-gated (manually interrupted) fashion.« less
Symmetry boost of the fidelity of Shor factoring

NASA Astrophysics Data System (ADS)

Nam, Y. S.; Blümel, R.

2018-05-01

In Shor's algorithm quantum subroutines occur with the structure F U F-1 , where F is a unitary transform and U is performing a quantum computation. Examples are quantum adders and subunits of quantum modulo adders. In this paper we show, both analytically and numerically, that if, in analogy to spin echoes, F and F-1 can be implemented symmetrically when executing Shor's algorithm on actual, imperfect quantum hardware, such that F and F-1 have the same hardware errors, a symmetry boost in the fidelity of the combined F U F-1 quantum operation results when compared to the case in which the errors in F and F-1 are independently random. Running the complete gate-by-gate implemented Shor algorithm, we show that the symmetry-induced fidelity boost can be as large as a factor 4. While most of our analytical and numerical results concern the case of over- and under-rotation of controlled rotation gates, in the numerically accessible case of Shor's algorithm with a small number of qubits, we show explicitly that the symmetry boost is robust with respect to more general types of errors. While, expectedly, additional error types reduce the symmetry boost, we show explicitly, by implementing general off-diagonal SU (N ) errors (N =2 ,4 ,8 ), that the boost factor scales like a Lorentzian in δ /σ , where σ and δ are the error strengths of the diagonal over- and underrotation errors and the off-diagonal SU (N ) errors, respectively. The Lorentzian shape also shows that, while the boost factor may become small with increasing δ , it declines slowly (essentially like a power law) and is never completely erased. We also investigate the effect of diagonal nonunitary errors, which, in analogy to unitary errors, reduce but never erase the symmetry boost. Going beyond the case of small quantum processors, we present analytical scaling results that show that the symmetry boost persists in the practically interesting case of a large number of qubits. We illustrate this result explicitly for the case of Shor factoring of the semiprime RSA-1024, where, analytically, focusing on over- and underrotation errors, we obtain a boost factor of about 10. In addition, we provide a proof of the fidelity product formula, including its range of applicability.
Temperature dependency of double material gate oxide (DMGO) symmetric dual-k spacer (SDS) wavy FinFET

NASA Astrophysics Data System (ADS)

Pradhan, K. P.; Priyanka; Sahu, P. K.

2016-01-01

Symmetric Dual-k Spacer (SDS) Trigate Wavy FinFET is a novel hybrid device that combines three significant and advanced technologies i.e., ultra-thin-body (UTB), FinFET, and symmetric spacer engineering on a single silicon on insulator (SOI) platform. This innovative architecture promises to enhance the device performance as compared to conventional FinFET without increasing the chip area. For the first time, we have incorporated two different dielectric materials (SiO2, and HfO2) as gate oxide to analyze the effect on various performance metrics of SDS wavy FinFET. This work evaluates the response of double material gate oxide (DMGO) on parameters like mobility, on current (Ion), transconductance (gm), transconductance generation factor (TGF), total gate capacitance (Cgg), and cutoff frequency (fT) in SDS wavy FinFET. This work also reveals the presence of biasing point i.e., zero temperature coefficient (ZTC) bias point. The ZTC bias point is that point where the device parameters become independent of temperature. The impact of operating temperature (T) on above said various performances are also subjected to extensive analysis. This further validates the reliability of DMGO-SDS FinFET and its application opportunities involved in modeling analog/RF circuits for a broad range of temperature applications. From extensive 3-D device simulation, we have determined that the inclusion of DMGO in SDS wavy FinFET is superior in performance.
Optimal arrangements of fiber optic probes to enhance the spatial resolution in depth for 3D reflectance diffuse optical tomography with time-resolved measurements performed with fast-gated single-photon avalanche diodes

NASA Astrophysics Data System (ADS)

Puszka, Agathe; Di Sieno, Laura; Dalla Mora, Alberto; Pifferi, Antonio; Contini, Davide; Boso, Gianluca; Tosi, Alberto; Hervé, Lionel; Planat-Chrétien, Anne; Koenig, Anne; Dinten, Jean-Marc

2014-02-01

Fiber optic probes with a width limited to a few centimeters can enable diffuse optical tomography (DOT) in intern organs like the prostate or facilitate the measurements on extern organs like the breast or the brain. We have recently shown on 2D tomographic images that time-resolved measurements with a large dynamic range obtained with fast-gated single-photon avalanche diodes (SPADs) could push forward the imaged depth range in a diffusive medium at short source-detector separation compared with conventional non-gated approaches. In this work, we confirm these performances with the first 3D tomographic images reconstructed with such a setup and processed with the Mellin- Laplace transform. More precisely, we investigate the performance of hand-held probes with short interfiber distances in terms of spatial resolution and specifically demonstrate the interest of having a compact probe design featuring small source-detector separations. We compare the spatial resolution obtained with two probes having the same design but different scale factors, the first one featuring only interfiber distances of 15 mm and the second one, 10 mm. We evaluate experimentally the spatial resolution obtained with each probe on the setup with fast-gated SPADs for optical phantoms featuring two absorbing inclusions positioned at different depths and conclude on the potential of short source-detector separations for DOT.
Photovoltaic and photothermoelectric effect in a double-gated WSe2 device.

PubMed

Groenendijk, Dirk J; Buscema, Michele; Steele, Gary A; Michaelis de Vasconcellos, Steffen; Bratschitsch, Rudolf; van der Zant, Herre S J; Castellanos-Gomez, Andres

2014-10-08

Tungsten diselenide (WSe2), a semiconducting transition metal dichalcogenide (TMDC), shows great potential as active material in optoelectronic devices due to its ambipolarity and direct bandgap in its single-layer form. Recently, different groups have exploited the ambipolarity of WSe2 to realize electrically tunable PN junctions, demonstrating its potential for digital electronics and solar cell applications. In this Letter, we focus on the different photocurrent generation mechanisms in a double-gated WSe2 device by measuring the photocurrent (and photovoltage) as the local gate voltages are varied independently in combination with above- and below-bandgap illumination. This enables us to distinguish between two main photocurrent generation mechanisms, the photovoltaic and photothermoelectric effect. We find that the dominant mechanism depends on the defined gate configuration. In the PN and NP configurations, photocurrent is mainly generated by the photovoltaic effect and the device displays a maximum responsivity of 0.70 mA/W at 532 nm illumination and rise and fall times close to 10 ms. Photocurrent generated by the photothermoelectric effect emerges in the PP configuration and is a factor of 2 larger than the current generated by the photovoltaic effect (in PN and NP configurations). This demonstrates that the photothermoelectric effect can play a significant role in devices based on WSe2 where a region of strong optical absorption, caused by, for example, an asymmetry in flake thickness or optical absorption of the electrodes, generates a sizable thermal gradient upon illumination.
Primary care physician supply and other key determinants of health care utilisation: the case of Switzerland

PubMed Central

Busato, André; Künzi, Beat

2008-01-01

Background The Swiss government decided to freeze new accreditations for physicians in private practice in Switzerland based on the assumption that demand-induced health care spending may be cut by limiting care offers. This legislation initiated an ongoing controversial public debate in Switzerland. The aim of this study is therefore the determination of socio-demographic and health system-related factors of per capita consultation rates with primary care physicians in the multicultural population of Switzerland. Methods The data were derived from the complete claims data of Swiss health insurers for 2004 and included 21.4 million consultations provided by 6564 Swiss primary care physicians on a fee-for-service basis. Socio-demographic data were obtained from the Swiss Federal Statistical Office. Utilisation-based health service areas were created and were used as observational units for statistical procedures. Multivariate and hierarchical models were applied to analyze the data. Results Models within the study allowed the definition of 1018 primary care service areas with a median population of 3754 and an average per capita consultation rate of 2.95 per year. Statistical models yielded significant effects for various geographical, socio-demographic and cultural factors. The regional density of physicians in independent practice was also significantly associated with annual consultation rates and indicated an associated increase 0.10 for each additional primary care physician in a population of 10,000 inhabitants. Considerable differences across Swiss language regions were observed with reference to the supply of ambulatory health resources provided either by primary care physicians, specialists, or hospital-based ambulatory care. Conclusion The study documents a large small-area variation in utilisation and provision of health care resources in Switzerland. Effects of physician density appeared to be strongly related to Swiss language regions and may be rooted in the different cultural backgrounds of the served populations. PMID:18190705
Primary care physician supply and other key determinants of health care utilisation: the case of Switzerland.

PubMed

Busato, André; Künzi, Beat

2008-01-11

The Swiss government decided to freeze new accreditations for physicians in private practice in Switzerland based on the assumption that demand-induced health care spending may be cut by limiting care offers. This legislation initiated an ongoing controversial public debate in Switzerland. The aim of this study is therefore the determination of socio-demographic and health system-related factors of per capita consultation rates with primary care physicians in the multicultural population of Switzerland. The data were derived from the complete claims data of Swiss health insurers for 2004 and included 21.4 million consultations provided by 6564 Swiss primary care physicians on a fee-for-service basis. Socio-demographic data were obtained from the Swiss Federal Statistical Office. Utilisation-based health service areas were created and were used as observational units for statistical procedures. Multivariate and hierarchical models were applied to analyze the data. Models within the study allowed the definition of 1018 primary care service areas with a median population of 3754 and an average per capita consultation rate of 2.95 per year. Statistical models yielded significant effects for various geographical, socio-demographic and cultural factors. The regional density of physicians in independent practice was also significantly associated with annual consultation rates and indicated an associated increase 0.10 for each additional primary care physician in a population of 10,000 inhabitants. Considerable differences across Swiss language regions were observed with reference to the supply of ambulatory health resources provided either by primary care physicians, specialists, or hospital-based ambulatory care. The study documents a large small-area variation in utilisation and provision of health care resources in Switzerland. Effects of physician density appeared to be strongly related to Swiss language regions and may be rooted in the different cultural backgrounds of the served populations.
Effects of demand-side financing on utilisation, experiences and outcomes of maternity care in low- and middle-income countries: a systematic review

PubMed Central

2014-01-01

Background Demand-side financing, where funds for specific services are channelled through, or to, prospective users, is now employed in health and education sectors in many low- and middle-income countries. This systematic review aimed to critically examine the evidence on application of this approach to promote maternal health in these settings. Five modes were considered: unconditional cash transfers, conditional cash transfers, short-term payments to offset costs of accessing maternity services, vouchers for maternity services, and vouchers for merit goods. We sought to assess the effects of these interventions on utilisation of maternity services and on maternal health outcomes and infant health, the situation of underprivileged women and the healthcare system. Methods The protocol aimed for collection and synthesis of a broad range of evidence from quantitative, qualitative and economic studies. Nineteen health and social policy databases, seven unpublished research databases and 27 websites were searched; with additional searches of Indian journals and websites. Studies were included if they examined demand-side financing interventions to increase consumption of services or goods intended to impact on maternal health, and met relevant quality criteria. Quality assessment, data extraction and analysis used Joanna Briggs Institute standardised tools and software. Outcomes of interest included maternal and infant mortality and morbidity, service utilisation, factors required for successful implementation, recipient and provider experiences, ethical issues, and cost-effectiveness. Findings on Effectiveness, Feasibility, Appropriateness and Meaningfulness were presented by narrative synthesis. Results Thirty-three quantitative studies, 46 qualitative studies, and four economic studies from 17 countries met the inclusion criteria. Evidence on unconditional cash transfers was scanty. Other demand-side financing modes were found to increase utilisation of maternal healthcare in the index pregnancy or uptake of related merit goods. Evidence of effects on maternal and infant mortality and morbidity outcomes was insufficient. Important implementation aspects include targeting and eligibility criteria, monitoring, respectful treatment of beneficiaries, suitable incentives for providers, quality of care and affordable referral systems. Conclusions Demand-side financing schemes can increase utilisation of maternity services, but attention must be paid to supply-side conditions, the fine-grain of implementation and sustainability. Comparative studies and research on health impact and cost-effectiveness are required. PMID:24438560

Effects of demand-side financing on utilisation, experiences and outcomes of maternity care in low- and middle-income countries: a systematic review.

PubMed

Murray, Susan F; Hunter, Benjamin M; Bisht, Ramila; Ensor, Tim; Bick, Debra

2014-01-17

Demand-side financing, where funds for specific services are channelled through, or to, prospective users, is now employed in health and education sectors in many low- and middle-income countries. This systematic review aimed to critically examine the evidence on application of this approach to promote maternal health in these settings. Five modes were considered: unconditional cash transfers, conditional cash transfers, short-term payments to offset costs of accessing maternity services, vouchers for maternity services, and vouchers for merit goods. We sought to assess the effects of these interventions on utilisation of maternity services and on maternal health outcomes and infant health, the situation of underprivileged women and the healthcare system. The protocol aimed for collection and synthesis of a broad range of evidence from quantitative, qualitative and economic studies. Nineteen health and social policy databases, seven unpublished research databases and 27 websites were searched; with additional searches of Indian journals and websites. Studies were included if they examined demand-side financing interventions to increase consumption of services or goods intended to impact on maternal health, and met relevant quality criteria. Quality assessment, data extraction and analysis used Joanna Briggs Institute standardised tools and software. Outcomes of interest included maternal and infant mortality and morbidity, service utilisation, factors required for successful implementation, recipient and provider experiences, ethical issues, and cost-effectiveness. Findings on Effectiveness, Feasibility, Appropriateness and Meaningfulness were presented by narrative synthesis. Thirty-three quantitative studies, 46 qualitative studies, and four economic studies from 17 countries met the inclusion criteria. Evidence on unconditional cash transfers was scanty. Other demand-side financing modes were found to increase utilisation of maternal healthcare in the index pregnancy or uptake of related merit goods. Evidence of effects on maternal and infant mortality and morbidity outcomes was insufficient. Important implementation aspects include targeting and eligibility criteria, monitoring, respectful treatment of beneficiaries, suitable incentives for providers, quality of care and affordable referral systems. Demand-side financing schemes can increase utilisation of maternity services, but attention must be paid to supply-side conditions, the fine-grain of implementation and sustainability. Comparative studies and research on health impact and cost-effectiveness are required.
Perspectives of men on antenatal and delivery care service utilisation in rural western Kenya: a qualitative study

PubMed Central

2013-01-01

Background Poor utilisation of facility-based antenatal and delivery care services in Kenya hampers reduction of maternal mortality. Studies suggest that the participation of men in antenatal and delivery care is associated with better health care seeking behaviour, yet many reproductive health programs do not facilitate their involvement. This qualitative study conducted in rural Western Kenya, explored men’s perceptions of antenatal and delivery care services and identified factors that facilitated or constrained their involvement. Methods Eight focus group discussions were conducted with 68 married men between 20-65 years of age in May 2011. Participants were of the Luo ethnic group residing in Asembo, western Kenya. The area has a high HIV-prevalence and polygamy is common. A topic guide was used to guide the discussions and a thematic framework approach for data analysis. Results Overall, men were positive in their views of antenatal and delivery care, as decision makers they often encouraged, some even ‘forced’, their wives to attend for antenatal or delivery care. Many reasons why it was beneficial to accompany their wives were provided, yet few did this in practice unless there was a clinical complication. The three main barriers relating to cultural norms identified were: 1) pregnancy support was considered a female role; and the male role that of provider; 2) negative health care worker attitudes towards men’s participation, and 3) couple unfriendly antenatal and delivery unit infrastructure. Conclusion Although men reported to facilitate their wives’ utilisation of antenatal and delivery care services, this does not translate to practice as adherence to antenatal-care schedules and facility based delivery is generally poor. Equally, reasons proffered why they should accompany their wives are not carried through into practice, with barriers outweighing facilitators. Recommendations to improve men involvement and potentially increase services utilisation include awareness campaigns targeting men, exploring promotion of joint HIV testing and counselling, staff training, and design of couple friendly antenatal and delivery units. PMID:23800139
Illness identity as an important component of candidacy: Contrasting experiences of help-seeking and access to care in cancer and heart disease.

PubMed

Macdonald, Sara; Blane, David; Browne, Susan; Conway, Ellie; Macleod, Una; May, Carl; Mair, Frances

2016-11-01

How and when we use health services or healthcare provision has dominated exploration of and debates around healthcare access. Levels of utilisation are assumed as a proxy for access. Yet, focusing on utilisation conceals an important aspect of the access conundrum: the relationships that patients and potential patients have with the healthcare system and the professionals within those systems. Candidacy has been proposed as an antidote to traditional utilisation models. The Candidacy construct offers the ability to include patient-professional aspects alongside utilisation and thus promotes a deeper understanding of access. Originally applied to healthcare access for vulnerable populations, additional socio-demographic factors, including age and ethnicity, have also been shown to influence the Candidacy process. Here we propose a further extension of the Candidacy construct and illustrate the importance of illness identities when accessing healthcare. Drawing on a secondary data analysis of three data sets of qualitative interviews from colorectal cancer and heart failure patients we found that though similar access issues are apparent pre-diagnosis, diagnosis marks a critical juncture in the experience of access. Cancer patients describe a person-centred responsive healthcare system where their patienthood requires only modest assertion. Cancer speaks for itself. In marked contrast heart failure patients, describe struggling within a seemingly impermeable system to understand their illness, its implications and their own legitimacy as patients. Our work highlights the pressing need for healthcare professionals, systems and policies to promote a person centred approach, which is responsive and timely, regardless of illness category. To achieve this, attitudes regarding the importance or priority afforded to different categories of illness need to be tackled as they directly influence ideas of Candidacy and consequently access and experiences of care. Copyright © 2016 Elsevier Ltd. All rights reserved.
Distance and utilisation of out-of-hours services in a Norwegian urban/rural district: an ecological study

PubMed Central

2013-01-01

Background Long travel distances limit the utilisation of health services. We wanted to examine the relationship between the utilisation of a Norwegian out-of-hours service and the distance from the municipality population centroid to the associated casualty clinic. Methods All first contacts from ten municipalities in Arendal out-of-hours district were registered from 2007 through 2011. The main outcomes were contact and consultation rates for each municipality for each year. The associations between main outcomes and distance from the population centroid of the participating municipalities to the casualty clinic and were examined by linear regression. Demographic and socioeconomic factors were included in multivariate linear regression. Secondary endpoints include association between distance and rates of different first actions taken and priority grades assessed by triage nurses. Age and gender specific subgroup analyses were performed. Results 141 342 contacts were included in the analyses. Increasing distance was associated with marked lower rates of all contact types except telephone consultations by doctor. Moving 43 kilometres away from the casualty clinic led to a 50 per cent drop in the rate of face-to-face consultations with a doctor. Availability of primary care doctors and education level contributed to a limited extent to the variance in consultation rate. The rates of all priority grades decreased significantly with increasing distance. The rate of acute events was reduced by 22 per cent when moving 50 kilometres away. The proportion of patients above 66 years increased with increasing distance, while the proportion of 13- to 19 year olds decreased. The proportion of female patients decreased with increasing distance. Conclusions The results confirm that increasing distance is associated with lower utilisation of out-of-hours services, even for the most acute cases. Extremely long distances might compromise patient safety. This must be taken into consideration when organising future out-of-hours districts. PMID:23773207
49 CFR 234.223 - Gate arm.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Gate arm. 234.223 Section 234.223 Transportation... Maintenance Standards § 234.223 Gate arm. Each gate arm, when in the downward position, shall extend across... clearly viewed by approaching highway users. Each gate arm shall start its downward motion not less than...
49 CFR 234.223 - Gate arm.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Gate arm. 234.223 Section 234.223 Transportation... SYSTEMS Maintenance, Inspection, and Testing Maintenance Standards § 234.223 Gate arm. Each gate arm, when... maintained in a condition sufficient to be clearly viewed by approaching highway users. Each gate arm shall...
49 CFR 234.223 - Gate arm.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Gate arm. 234.223 Section 234.223 Transportation... SYSTEMS Maintenance, Inspection, and Testing Maintenance Standards § 234.223 Gate arm. Each gate arm, when... maintained in a condition sufficient to be clearly viewed by approaching highway users. Each gate arm shall...
49 CFR 234.223 - Gate arm.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Gate arm. 234.223 Section 234.223 Transportation... Maintenance Standards § 234.223 Gate arm. Each gate arm, when in the downward position, shall extend across... clearly viewed by approaching highway users. Each gate arm shall start its downward motion not less than...
49 CFR 234.223 - Gate arm.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Gate arm. 234.223 Section 234.223 Transportation... SYSTEMS Maintenance, Inspection, and Testing Maintenance Standards § 234.223 Gate arm. Each gate arm, when... maintained in a condition sufficient to be clearly viewed by approaching highway users. Each gate arm shall...
Radiation Effects On Emerging Electronic Materials And Devices

DTIC Science & Technology

2010-01-17

RADIATION EFFECTS ON EMERGING ELECTRONIC MATERIALS AND DEVICES FINAL PERFORMANCE REPORT PREPARED FOR: Kitt Reinhardt AFOSR/NE 875 N...and the other with metal gates and a high-K gate dielectric. These devices were programmed using both back-gate pulse and gate induced drain leakage... metal gate process GIDL method Fig. 1. Sensing margin as a function of total ionizing dose for nMOS 1T-DRAM cells programmed by back-gate pulse and
Terahertz amplification in RTD-gated HEMTs with a grating-gate wave coupling topology

NASA Astrophysics Data System (ADS)

Condori Quispe, Hugo O.; Encomendero-Risco, Jimy J.; Xing, Huili Grace; Sensale-Rodriguez, Berardi

2016-08-01

We theoretically analyze the operation of a terahertz amplifier consisting of a resonant-tunneling-diode gated high-electron-mobility transistor (RTD-gated HEMT) in a grating-gate topology. In these devices, the key element enabling substantial power gain is the efficient coupling of terahertz waves into and out of plasmons in the RTD-gated HEMT channel, i.e., the gain medium, via the grating-gate itself, part of the active device, rather than by an external antenna structure as discussed in previous works, therefore potentially enabling terahertz amplification with associated power gains >40 dB.
Terahertz amplification in RTD-gated HEMTs with a grating-gate wave coupling topology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Condori Quispe, Hugo O.; Sensale-Rodriguez, Berardi; Encomendero-Risco, Jimy J.

2016-08-08

We theoretically analyze the operation of a terahertz amplifier consisting of a resonant-tunneling-diode gated high-electron-mobility transistor (RTD-gated HEMT) in a grating-gate topology. In these devices, the key element enabling substantial power gain is the efficient coupling of terahertz waves into and out of plasmons in the RTD-gated HEMT channel, i.e., the gain medium, via the grating-gate itself, part of the active device, rather than by an external antenna structure as discussed in previous works, therefore potentially enabling terahertz amplification with associated power gains >40 dB.
Vehicle barrier

DOEpatents

Hirsh, Robert A.

1991-01-01

A vehicle security barrier which can be conveniently placed across a gate opening as well as readily removed from the gate opening to allow for easy passage. The security barrier includes a barrier gate in the form of a cable/gate member in combination with laterally attached pipe sections fixed by way of the cable to the gate member and lateral, security fixed vertical pipe posts. The security barrier of the present invention provides for the use of cable restraints across gate openings to provide necessary security while at the same time allowing for quick opening and closing of the gate areas without compromising security.
A modular design of molecular qubits to implement universal quantum gates

PubMed Central

Ferrando-Soria, Jesús; Moreno Pineda, Eufemio; Chiesa, Alessandro; Fernandez, Antonio; Magee, Samantha A.; Carretta, Stefano; Santini, Paolo; Vitorica-Yrezabal, Iñigo J.; Tuna, Floriana; Timco, Grigore A.; McInnes, Eric J.L.; Winpenny, Richard E.P.

2016-01-01

The physical implementation of quantum information processing relies on individual modules—qubits—and operations that modify such modules either individually or in groups—quantum gates. Two examples of gates that entangle pairs of qubits are the controlled NOT-gate (CNOT) gate, which flips the state of one qubit depending on the state of another, and the gate that brings a two-qubit product state into a superposition involving partially swapping the qubit states. Here we show that through supramolecular chemistry a single simple module, molecular {Cr7Ni} rings, which act as the qubits, can be assembled into structures suitable for either the CNOT or gate by choice of linker, and we characterize these structures by electron spin resonance spectroscopy. We introduce two schemes for implementing such gates with these supramolecular assemblies and perform detailed simulations, based on the measured parameters including decoherence, to demonstrate how the gates would operate. PMID:27109358
Coupling of activation and inactivation gate in a K+-channel: potassium and ligand sensitivity

PubMed Central

Ader, Christian; Schneider, Robert; Hornig, Sönke; Velisetty, Phanindra; Vardanyan, Vitya; Giller, Karin; Ohmert, Iris; Becker, Stefan; Pongs, Olaf; Baldus, Marc

2009-01-01

Potassium (K+)-channel gating is choreographed by a complex interplay between external stimuli, K+ concentration and lipidic environment. We combined solid-state NMR and electrophysiological experiments on a chimeric KcsA–Kv1.3 channel to delineate K+, pH and blocker effects on channel structure and function in a membrane setting. Our data show that pH-induced activation is correlated with protonation of glutamate residues at or near the activation gate. Moreover, K+ and channel blockers distinctly affect the open probability of both the inactivation gate comprising the selectivity filter of the channel and the activation gate. The results indicate that the two gates are coupled and that effects of the permeant K+ ion on the inactivation gate modulate activation-gate opening. Our data suggest a mechanism for controlling coordinated and sequential opening and closing of activation and inactivation gates in the K+-channel pore. PMID:19661921
Micromachined mold-type double-gated metal field emitters

NASA Astrophysics Data System (ADS)

Lee, Yongjae; Kang, Seokho; Chun, Kukjin

1997-12-01

Electron field emitters with double gates were fabricated using micromachining technology and the effect of the electric potential of the focusing gate (or second gate) was experimentally evaluated. The molybdenum field emission tip was made by filling a cusplike mold formed when a conformal film was deposited on the hole-trench that had been patterned on stacked metals and dielectric layers. The hole-trench was patterned by electron beam lithography and reactive ion etching. Each field emitter has a 0960-1317/7/4/009/img1 diameter extraction gate (or first gate) and a 0960-1317/7/4/009/img2 diameter focusing gate (or second gate). To make a path for the emitted electrons, silicon bulk was etched anisotropically in KOH and EDP (ethylene-diamine pyrocatechol) solution successively. The I - V characteristics and anode current change due to the focusing gate potential were measured.
A Novel Implementation of Efficient Algorithms for Quantum Circuit Synthesis

NASA Astrophysics Data System (ADS)

Zeller, Luke

In this project, we design and develop a computer program to effectively approximate arbitrary quantum gates using the discrete set of Clifford Gates together with the T gate (π/8 gate). Employing recent results from Mosca et. al. and Giles and Selinger, we implement a decomposition scheme that outputs a sequence of Clifford, T, and Tt gates that approximate the input to within a specified error range ɛ. Specifically, the given gate is first rounded to an element of Z[1/2, i] with a precision determined by ɛ, and then exact synthesis is employed to produce the resulting gate. It is known that this procedure is optimal in approximating an arbitrary single qubit gate. Our program, written in Matlab and Python, can complete both approximate and exact synthesis of qubits. It can be used to assist in the experimental implementation of an arbitrary fault-tolerant single qubit gate, for which direct implementation isn't feasible.
DIFMOS - A floating-gate electrically erasable nonvolatile semiconductor memory technology. [Dual Injector Floating-gate MOS

NASA Technical Reports Server (NTRS)

Gosney, W. M.

1977-01-01

Electrically alterable read-only memories (EAROM's) or reprogrammable read-only memories (RPROM's) can be fabricated using a single-level metal-gate p-channel MOS technology with all conventional processing steps. Given the acronym DIFMOS for dual-injector floating-gate MOS, this technology utilizes the floating-gate technique for nonvolatile storage of data. Avalanche injection of hot electrons through gate oxide from a special injector diode in each bit is used to charge the floating gates. A second injector structure included in each bit permits discharge of the floating gate by avalanche injection of holes through gate oxide. The overall design of the DIFMOS bit is dictated by the physical considerations required for each of the avalanche injector types. The end result is a circuit technology which can provide fully decoded bit-erasable EAROM-type circuits using conventional manufacturing techniques.
Top-gate pentacene-based organic field-effect transistor with amorphous rubrene gate insulator

NASA Astrophysics Data System (ADS)

Hiroki, Mizuha; Maeda, Yasutaka; Ohmi, Shun-ichiro

2018-02-01

The scaling of organic field-effect transistors (OFETs) is necessary for high-density integration and for this, OFETs with a top-gate configuration are required. There have been several reports of damageless lithography processes for organic semiconductor or insulator layers. However, it is still difficult to fabricate scaled OFETs with a top-gate configuration. In this study, the lift-off process and the device characteristics of the OFETs with a top-gate configuration utilizing an amorphous (α) rubrene gate insulator were investigated. We have confirmed that α-rubrene shows an insulating property, and its extracted linear mobility was 2.5 × 10-2 cm2/(V·s). The gate length and width were 10 and 60 µm, respectively. From these results, the OFET with a top-gate configuration utilizing an α-rubrene gate insulator is promising for the high-density integration of scaled OFETs.
Effect of gate bias sweep rate on the threshold voltage of in-plane gate nanowire transistor

NASA Astrophysics Data System (ADS)

Liu, H. X.; Li, J.; Tan, R. R.

2018-01-01

In2O3 nanowire electric-double-layer (EDL) transistors with in-plane gate gated by SiO2 solid-electrolyte are fabricated on transparent glass substrates. The gate voltage sweep rates can effectively modulate the threshold voltage (Vth) of nanowire device. Both depletion mode and enhancement mode are realized, and the Vth shift of the nanowire transistors is estimated to be 0.73V (without light). This phenomenon is due to increased adsorption of oxygen on the nanowire surface by the slower gate voltage sweep rates. Adsorbed oxygens capture electrons and cause a surface of nanowire channel was depleted. The operation voltage of transistor was 1.0 V, because the EDL gate dielectric can lead to high gate dielectric capacitance. These transparent in-plane gate nanowire transistors are promising for “see-through” nanoscale sensors.

Efficient Z gates for quantum computing

NASA Astrophysics Data System (ADS)

McKay, David C.; Wood, Christopher J.; Sheldon, Sarah; Chow, Jerry M.; Gambetta, Jay M.

2017-08-01

For superconducting qubits, microwave pulses drive rotations around the Bloch sphere. The phase of these drives can be used to generate zero-duration arbitrary virtual Z gates, which, combined with two Xπ /2 gates, can generate any SU(2) gate. Here we show how to best utilize these virtual Z gates to both improve algorithms and correct pulse errors. We perform randomized benchmarking using a Clifford set of Hadamard and Z gates and show that the error per Clifford is reduced versus a set consisting of standard finite-duration X and Y gates. Z gates can correct unitary rotation errors for weakly anharmonic qubits as an alternative to pulse-shaping techniques such as derivative removal by adiabatic gate (DRAG). We investigate leakage and show that a combination of DRAG pulse shaping to minimize leakage and Z gates to correct rotation errors realizes a 13.3 ns Xπ /2 gate characterized by low error [1.95 (3 ) ×10-4] and low leakage [3.1 (6 ) ×10-6] . Ultimately leakage is limited by the finite temperature of the qubit, but this limit is two orders of magnitude smaller than pulse errors due to decoherence.
100-nm gate lithography for double-gate transistors

NASA Astrophysics Data System (ADS)

Krasnoperova, Azalia A.; Zhang, Ying; Babich, Inna V.; Treichler, John; Yoon, Jung H.; Guarini, Kathryn; Solomon, Paul M.

2001-09-01

The double gate field effect transistor (FET) is an exploratory device that promises certain performance advantages compared to traditional CMOS FETs. It can be scaled down further than the traditional devices because of the greater electrostatic control by the gates on the channel (about twice as short a channel length for the same gate oxide thickness), has steeper sub-threshold slope and about double the current for the same width. This paper presents lithographic results for double gate FET's developed at IBM's T. J. Watson Research Center. The device is built on bonded wafers with top and bottom gates self-aligned to each other. The channel is sandwiched between the top and bottom polysilicon gates and the gate length is defined using DUV lithography. An alternating phase shift mask was used to pattern gates with critical dimensions of 75 nm, 100 nm and 125 nm in photoresist. 50 nm gates in photoresist have also been patterned by 20% over-exposure of nominal 100 nm lines. No trim mask was needed because of a specific way the device was laid out. UV110 photoresist from Shipley on AR-3 antireflective layer were used. Process windows, developed and etched patterns are presented.
Efficient Nonlocal M-Control and N-Target Controlled Unitary Gate Using Non-symmetric GHZ States

NASA Astrophysics Data System (ADS)

Chen, Li-Bing; Lu, Hong

2018-03-01

Efficient local implementation of a nonlocal M-control and N-target controlled unitary gate is considered. We first show that with the assistance of two non-symmetric qubit(1)-qutrit(N) Greenberger-Horne-Zeilinger (GHZ) states, a nonlocal 2-control and N-target controlled unitary gate can be constructed from 2 local two-qubit CNOT gates, 2 N local two-qutrit conditional SWAP gates, N local qutrit-qubit controlled unitary gates, and 2 N single-qutrit gates. At each target node, the two third levels of the two GHZ target qutrits are used to expose one and only one initial computational state to the local qutrit-qubit controlled unitary gate, instead of being used to hide certain states from the conditional dynamics. This scheme can be generalized straightforwardly to implement a higher-order nonlocal M-control and N-target controlled unitary gate by using M non-symmetric qubit(1)-qutrit(N) GHZ states as quantum channels. Neither the number of the additional levels of each GHZ target particle nor that of single-qutrit gates needs to increase with M. For certain realistic physical systems, the total gate time may be reduced compared with that required in previous schemes.
Reversibility and energy dissipation in adiabatic superconductor logic.

PubMed

Takeuchi, Naoki; Yamanashi, Yuki; Yoshikawa, Nobuyuki

2017-03-06

Reversible computing is considered to be a key technology to achieve an extremely high energy efficiency in future computers. In this study, we investigated the relationship between reversibility and energy dissipation in adiabatic superconductor logic. We analyzed the evolution of phase differences of Josephson junctions in the reversible quantum-flux-parametron (RQFP) gate and confirmed that the phase differences can change time reversibly, which indicates that the RQFP gate is physically, as well as logically, reversible. We calculated energy dissipation required for the RQFP gate to perform a logic operation and numerically demonstrated that the energy dissipation can fall below the thermal limit, or the Landauer bound, by lowering operation frequencies. We also investigated the 1-bit-erasure gate as a logically irreversible gate and the quasi-RQFP gate as a physically irreversible gate. We calculated the energy dissipation of these irreversible gates and showed that the energy dissipation of these gate is dominated by non-adiabatic state changes, which are induced by unwanted interactions between gates due to logical or physical irreversibility. Our results show that, in reversible computing using adiabatic superconductor logic, logical and physical reversibility are required to achieve energy dissipation smaller than the Landauer bound without non-adiabatic processes caused by gate interactions.
High-fidelity gates in quantum dot spin qubits.

PubMed

Koh, Teck Seng; Coppersmith, S N; Friesen, Mark

2013-12-03

Several logical qubits and quantum gates have been proposed for semiconductor quantum dots controlled by voltages applied to top gates. The different schemes can be difficult to compare meaningfully. Here we develop a theoretical framework to evaluate disparate qubit-gating schemes on an equal footing. We apply the procedure to two types of double-dot qubits: the singlet-triplet and the semiconducting quantum dot hybrid qubit. We investigate three quantum gates that flip the qubit state: a DC pulsed gate, an AC gate based on logical qubit resonance, and a gate-like process known as stimulated Raman adiabatic passage. These gates are all mediated by an exchange interaction that is controlled experimentally using the interdot tunnel coupling g and the detuning [Symbol: see text], which sets the energy difference between the dots. Our procedure has two steps. First, we optimize the gate fidelity (f) for fixed g as a function of the other control parameters; this yields an f(opt)(g) that is universal for different types of gates. Next, we identify physical constraints on the control parameters; this yields an upper bound f(max) that is specific to the qubit-gate combination. We show that similar gate fidelities (~99:5%) should be attainable for singlet-triplet qubits in isotopically purified Si, and for hybrid qubits in natural Si. Considerably lower fidelities are obtained for GaAs devices, due to the fluctuating magnetic fields ΔB produced by nuclear spins.
Effects of rhythmic stimulus presentation on oscillatory brain activity: the physiology of cueing in Parkinson’s disease

PubMed Central

te Woerd, Erik S.; Oostenveld, Robert; Bloem, Bastiaan R.; de Lange, Floris P.; Praamstra, Peter

2015-01-01

The basal ganglia play an important role in beat perception and patients with Parkinson’s disease (PD) are impaired in perception of beat-based rhythms. Rhythmic cues are nonetheless beneficial in gait rehabilitation, raising the question how rhythm improves movement in PD. We addressed this question with magnetoencephalography recordings during a choice response task with rhythmic and non-rhythmic modes of stimulus presentation. Analyses focused on (i) entrainment of slow oscillations, (ii) the depth of beta power modulation, and (iii) whether a gain in modulation depth of beta power, due to rhythmicity, is of predictive or reactive nature. The results show weaker phase synchronisation of slow oscillations and a relative shift from predictive to reactive movement-related beta suppression in PD. Nonetheless, rhythmic stimulus presentation increased beta modulation depth to the same extent in patients and controls. Critically, this gain selectively increased the predictive and not reactive movement-related beta power suppression. Operation of a predictive mechanism, induced by rhythmic stimulation, was corroborated by a sensory gating effect in the sensorimotor cortex. The predictive mode of cue utilisation points to facilitation of basal ganglia-premotor interactions, contrasting with the popular view that rhythmic stimulation confers a special advantage in PD, based on recruitment of alternative pathways. PMID:26509117
An extended diffraction tomography method for quantifying structural damage using numerical Green's functions.

PubMed

Chan, Eugene; Rose, L R Francis; Wang, Chun H

2015-05-01

Existing damage imaging algorithms for detecting and quantifying structural defects, particularly those based on diffraction tomography, assume far-field conditions for the scattered field data. This paper presents a major extension of diffraction tomography that can overcome this limitation and utilises a near-field multi-static data matrix as the input data. This new algorithm, which employs numerical solutions of the dynamic Green's functions, makes it possible to quantitatively image laminar damage even in complex structures for which the dynamic Green's functions are not available analytically. To validate this new method, the numerical Green's functions and the multi-static data matrix for laminar damage in flat and stiffened isotropic plates are first determined using finite element models. Next, these results are time-gated to remove boundary reflections, followed by discrete Fourier transform to obtain the amplitude and phase information for both the baseline (damage-free) and the scattered wave fields. Using these computationally generated results and experimental verification, it is shown that the new imaging algorithm is capable of accurately determining the damage geometry, size and severity for a variety of damage sizes and shapes, including multi-site damage. Some aspects of minimal sensors requirement pertinent to image quality and practical implementation are also briefly discussed. Copyright © 2015 Elsevier B.V. All rights reserved.
Inequalities in utilisation of general practitioner and specialist services in 9 European countries.

PubMed

Stirbu, Irina; Kunst, Anton E; Mielck, Andreas; Mackenbach, Johan P

2011-10-31

The aim of this study is to describe the magnitude of educational inequalities in utilisation of general practitioner (GP) and specialist services in 9 European countries. In addition to West European countries, we have included 3 Eastern European countries: Hungary, Estonia and Latvia. To cover the gap in knowledge we pay a special attention to the magnitude of inequalities among patients with chronic conditions. Data on the use of GP and specialist services were derived from national health surveys of Belgium, Estonia, France, Germany, Hungary, Ireland, Latvia, the Netherlands and Norway. For each country and education level we calculated the absolute prevalence and relative inequalities in utilisation of GP and specialist services. In order to account for the need for care, the results were adjusted by the measure of self-assessed health. People with lower education used GP services equally often in most countries (except Belgium and Germany) compared with those with a higher level of education. At the same time people with a higher education used specialist care services significantly more often in all countries, except in the Netherlands. The general pattern of educational inequalities in utilisation of specialist care was similar for both men and women. Inequalities in utilisation of specialist care were equally large in Eastern European and in Western European countries, except for Latvia where the inequalities were somewhat larger. Similarly, large inequalities were found in the utilisation of specialist care among patients with chronic diseases, diabetes, and hypertension. We found large inequalities in the utilisation of specialist care. These inequalities were not compensated by utilisation of GP services. Of particular concern is the presence of inequalities among patients with a high need for specialist care, such as those with chronic diseases. © 2011 Stirbu et al; licensee BioMed Central Ltd.
Design Guidelines and Criteria for User/Operator Transactions with Battlefield Automated Systems. Volume I. Executive Summary

DTIC Science & Technology

1981-02-01

SUMMARY Robert N. Parrish, Jesse L. Gates, and Sarah J. Munger SYNECTICS CORPORATION HUMAN FACTORS TECHNICAL AREA L.. .iU. S. Army Research Institute for...of the Human Factors Technical Area, ARI, is the Contracting Officer’s Representative (COR) for this project. 19. KEY WORDS (Continue on reverse...aide It neceeary ad Identify by block number) Battlefield automated systems Human -computer interaction Design criteria System analysis Design guidelines
Sounding the warning bells: the need for a systems approach to understanding behaviour at rail level crossings.

PubMed

Read, Gemma J M; Salmon, Paul M; Lenné, Michael G

2013-09-01

Collisions at rail level crossings are an international safety concern and have been the subject of considerable research effort. Modern human factors practice advocates a systems approach to investigating safety issues in complex systems. This paper describes the results of a structured review of the level crossing literature to determine the extent to which a systems approach has been applied. The measures used to determine if previous research was underpinned by a systems approach were: the type of analysis method utilised, the number of component relationships considered, the number of user groups considered, the number of system levels considered and the type of model described in the research. None of research reviewed was found to be consistent with a systems approach. It is recommended that further research utilise a systems approach to the study of the level crossing system to enable the identification of effective design improvements. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.
'I was just so different': The experiences of women diagnosed with an autism spectrum disorder in adulthood in relation to gender and social relationships.

PubMed

Kanfiszer, Lucie; Davies, Fran; Collins, Suzanne

2017-08-01

Existing literature exploring autism spectrum disorders within female populations predominantly utilises quantitative methodology. A limited number of small-scale, qualitative studies have explored the experiences of adolescent girls with autism spectrum disorder, but adult women have remained largely unheard. This study aims to broaden the stories told within autobiographical literature and empower those within the wider community of women with autism spectrum disorder. In doing so, it seeks to extend existing conceptualisations of experience to include socially and culturally located factors. A qualitative methodology was adopted, utilising multi-stage narrative analysis. Seven semi-structured interviews with women who received a diagnosis in adulthood were conducted. Recruitment spanned community mental health services, an inpatient service and a community support group. From the women's diverse experiences and stories emerged two broad categories related to gender identity and social relationships. The findings are discussed in relation to existing constructs of autism in women.
ZnO-based multiple channel and multiple gate FinMOSFETs

NASA Astrophysics Data System (ADS)

Lee, Ching-Ting; Huang, Hung-Lin; Tseng, Chun-Yen; Lee, Hsin-Ying

2016-02-01

In recent years, zinc oxide (ZnO)-based metal-oxide-semiconductor field-effect transistors (MOSFETs) have attracted much attention, because ZnO-based semiconductors possess several advantages, including large exciton binding energy, nontoxicity, biocompatibility, low material cost, and wide direct bandgap. Moreover, the ZnO-based MOSFET is one of most potential devices, due to the applications in microwave power amplifiers, logic circuits, large scale integrated circuits, and logic swing. In this study, to enhance the performances of the ZnO-based MOSFETs, the ZnObased multiple channel and multiple gate structured FinMOSFETs were fabricated using the simple laser interference photolithography method and the self-aligned photolithography method. The multiple channel structure possessed the additional sidewall depletion width control ability to improve the channel controllability, because the multiple channel sidewall portions were surrounded by the gate electrode. Furthermore, the multiple gate structure had a shorter distance between source and gate and a shorter gate length between two gates to enhance the gate operating performances. Besides, the shorter distance between source and gate could enhance the electron velocity in the channel fin structure of the multiple gate structure. In this work, ninety one channels and four gates were used in the FinMOSFETs. Consequently, the drain-source saturation current (IDSS) and maximum transconductance (gm) of the ZnO-based multiple channel and multiple gate structured FinFETs operated at a drain-source voltage (VDS) of 10 V and a gate-source voltage (VGS) of 0 V were respectively improved from 11.5 mA/mm to 13.7 mA/mm and from 4.1 mS/mm to 6.9 mS/mm in comparison with that of the conventional ZnO-based single channel and single gate MOSFETs.
Performance comparison of single and dual metal dielectrically modulated TFETs for the application of label free biosensor

NASA Astrophysics Data System (ADS)

Verma, Madhulika; Sharma, Dheeraj; Pandey, Sunil; Nigam, Kaushal; Kondekar, P. N.

2017-01-01

In this work, we perform a comparative analysis between single and dual metal dielectrically modulated tunnel field-effect transistors (DMTFETs) for the application of label free biosensor. For this purpose, two different gate material with work-function as ϕM 1 and ϕM 2 are used in short-gate DMTFET, where ϕM 1 represents the work-function of gate M1 near to the drain end, while ϕM 2 denotes the work-function of gate M2 near to the source end. A nanogap cavity in the gate dielectric is formed by removing the selected portion of gate oxide for sensing the biomolecules. To investigate the sensitivity of these biosensors, dielectric constant and charge density within the cavity region are considered as governing parameters. The work-function of gate M2 is optimized and considered less than M1 to achieve abruptness at the source/channel junction, which results in better tunneling and improved ON-state current. The ATLAS device simulations show that dual metal SG-DMTFETs attains higher ON-state current and drain current sensitivity as compared to its counterpart device. Finally, a dual metal short-gate (DSG) biosensor is compared with the single metal short-gate (SG), single metal full-gate (FG), and dual metal full-gate (DFG) biosensors to analyse structurally enhanced conjugation effect on gate-channel coupling.
Comparison of LVEF assessed by 2D echocardiography, gated blood pool SPECT, 99mTc tetrofosmin gated SPECT, and 18F-FDG gated PET with ERNV in patients with CAD and severe LV dysfunction.

PubMed

Raja, Senthil; Mittal, Bhagwant R; Santhosh, Sampath; Bhattacharya, Anish; Rohit, Manoj K

2014-11-01

Left ventricular ejection fraction (LVEF) is the single most important predictor of prognosis in patients with coronary artery disease (CAD) and left ventricular (LV) dysfunction. Equilibrium radionuclide ventriculography (ERNV) is considered the most reliable technique for assessing LVEF. Most of these patients undergo two dimensional (2D) echocardiography and myocardial viability study using gated myocardial perfusion imaging (MPI) or gated F-fluorodeoxyglucose (F-FDG) PET. However, the accuracy of LVEF assessed by these methods is not clear. This study has been designed to assess the correlation and agreement between the LVEF measured by 2D echocardiography, gated blood pool single photon emission computed tomography (SPECT), Tc tetrofosmin gated SPECT, and F-FDG gated PET with ERNV in CAD patients with severe LV dysfunction. Patients with CAD and severe LV dysfunction [ejection fraction (EF) <35 assessed by 2D echocardiography] were prospectively included in the study. These patients underwent ERNV along with gated blood pool SPECT, Tc tetrofosmin gated SPECT, and F-FDG gated PET as per the standard protocol for myocardial viability assessment and LVEF calculation. Spearman's coefficient of correlation (r) was calculated for the different sets of values with significance level kept at a P-value less than 0.05. Bland-Altman plots were inspected to visually assess the between-agreement measurements from different methods. Forty-one patients were prospectively included. LVEF calculated by various radionuclide methods showed good correlation with ERNV as follows: gated blood pool SPECT, r=0.92; MPI gated SPECT, r=0.85; and F-FDG gated PET, r=0.76. However, the correlation between 2D echocardiography and ERNV was poor (r=0.520). The Bland-Altman plot for LVEF measured by all radionuclide methods showed good agreement with ERNV. However, agreement between 2D echocardiography and ERNV is poor, as most of the values in this plot gave a negative difference for low EF and a positive difference for high EF. The mean difference between various techniques [2D echocardiography (a), gated blood pool SPECT (b), MPI gated SPECT (c), F-FDG gated PET (d)] and ERNV (e) was as follows: (a)-(e), 3.3; (b)-(e), 5; (c)-(e), 1.1; and (d)-(e), 2.9. The best possible correlation and agreement was found between MPI gated SPECT and ERNV. This study showed good correlation and agreement between MPI gated SPECT and F-FDG gated PET with ERNV for LVEF calculation in CAD patients with severe LV dysfunction. Thus, subjecting patients who undergo viability assessment by MPI gated SPECT or F-FDG gated PET to a separate procedure like ERNV for LVEF assessment may not be warranted. As the gated blood pool SPECT also showed good correlation and agreement with ERNV for LVEF assessment in CAD patients with severe LV dysfunction, with better characteristics than ERNV, it can be routinely used whenever accurate LVEF assessment is needed.
Interface trap of p-type gate integrated AlGaN/GaN heterostructure field effect transistors

NASA Astrophysics Data System (ADS)

Kim, Kyu Sang

2017-09-01

In this work, the impact of trap states at the p-(Al)GaN/AlGaN interface has been investigated for the normally-off mode p-(Al)GaN/AlGaN/GaN heterostructure field-effect transistors (HFETs) by means of frequency dependent conductance. From the current-voltage (I-V) measurement, it was found that the p-AlGaN gate integrated device has higher drain current and lower gate leakage current compared to the p-GaN gate integrated device. We obtained the interface trap density and the characteristic time constant for the p-type gate integrated HFETs under the forward gate voltage of up to 6 V. As a result, the interface trap density (characteristic time constant) of the p-GaN gate device was lower (longer) than that of the p-AlGaN. Furthermore, it was analyzed that the trap state energy level of the p-GaN gate device was located at the shallow level relative to the p-AlGaN gate device, which accounts for different gate leakage current of each devices.
Universal photonic quantum gates assisted by ancilla diamond nitrogen-vacancy centers coupled to resonators

NASA Astrophysics Data System (ADS)

Wei, Hai-Rui; Long, Gui Lu

2015-03-01

We propose two compact, economic, and scalable schemes for implementing optical controlled-phase-flip and controlled-controlled-phase-flip gates by using the input-output process of a single-sided cavity strongly coupled to a single nitrogen-vacancy-center defect in diamond. Additional photonic qubits, necessary for procedures based on the parity-check measurement or controlled-path and merging gates, are not employed in our schemes. In the controlled-path gate, the paths of the target photon are conditionally controlled by the control photon, and these two paths can be merged back into one by using a merging gate. Only one half-wave plate is employed in our scheme for the controlled-phase-flip gate. Compared with the conventional synthesis procedures for constructing a controlled-controlled-phase-flip gate, the cost of which is two controlled-path gates and two merging gates, or six controlled-not gates, our scheme is more compact and simpler. Our schemes could be performed with a high fidelity and high efficiency with current achievable experimental techniques.
Image-guided adaptive gating of lung cancer radiotherapy: a computer simulation study

NASA Astrophysics Data System (ADS)

Aristophanous, Michalis; Rottmann, Joerg; Park, Sang-June; Nishioka, Seiko; Shirato, Hiroki; Berbeco, Ross I.

2010-08-01

The purpose of this study is to investigate the effect that image-guided adaptation of the gating window during treatment could have on the residual tumor motion, by simulating different gated radiotherapy techniques. There are three separate components of this simulation: (1) the 'Hokkaido Data', which are previously measured 3D data of lung tumor motion tracks and the corresponding 1D respiratory signals obtained during the entire ungated radiotherapy treatments of eight patients, (2) the respiratory gating protocol at our institution and the imaging performed under that protocol and (3) the actual simulation in which the Hokkaido Data are used to select tumor position information that could have been collected based on the imaging performed under our gating protocol. We simulated treatments with a fixed gating window and a gating window that is updated during treatment. The patient data were divided into different fractions, each with continuous acquisitions longer than 2 min. In accordance to the imaging performed under our gating protocol, we assume that we have tumor position information for the first 15 s of treatment, obtained from kV fluoroscopy, and for the rest of the fractions the tumor position is only available during the beam-on time from MV imaging. The gating window was set according to the information obtained from the first 15 s such that the residual motion was less than 3 mm. For the fixed gating window technique the gate remained the same for the entire treatment, while for the adaptive technique the range of the tumor motion during beam-on time was measured and used to adapt the gating window to keep the residual motion below 3 mm. The algorithm used to adapt the gating window is described. The residual tumor motion inside the gating window was reduced on average by 24% for the patients with regular breathing patterns and the difference was statistically significant (p-value = 0.01). The magnitude of the residual tumor motion depended on the regularity of the breathing pattern suggesting that image-guided adaptive gating should be combined with breath coaching. The adaptive gating window technique was able to track the exhale position of the breathing cycle quite successfully. Out of a total of 53 fractions the duty cycle was greater than 20% for 42 fractions for the fixed gating window technique and for 39 fractions for the adaptive gating window technique. The results of this study suggest that real-time updating of the gating window can result in reliably low residual tumor motion and therefore can facilitate safe margin reduction.
Effects of Iron Gate Dam discharge and other factors on the survival and migration of juvenile coho salmon in the lower Klamath River, northern California, 2006-09

USGS Publications Warehouse

Beeman, John; Juhnke, Steven; Stutzer, Greg; Wright, Katrina

2012-01-01

Current management of the Klamath River includes prescribed minimum discharges intended partly to increase survival of juvenile coho salmon during their seaward migration in the spring. To determine if fish survival was related to river discharge, we estimated apparent survival and migration rates of yearling coho salmon in the Klamath River downstream of Iron Gate Dam. The primary goals were to determine if discharge at Iron Gate Dam affected coho salmon survival and if results from hatchery fish could be used as a surrogate for the limited supply of wild fish. Fish from hatchery and wild origins that had been surgically implanted with radio transmitters were released into the Klamath River slightly downstream of Iron Gate Dam at river kilometer 309. Tagged fish were used to estimate apparent survival between, and passage rates at, a series of detection sites as far downstream as river kilometer 33. Conclusions were based primarily on data from hatchery fish, because wild fish were only available in 2 of the 4 years of study. Based on an information-theoretic approach, apparent survival of hatchery and wild fish was similar, despite differences in passage rates and timing, and was lowest in the 54 kilometer (km) reach between release and the Scott River. Models representing the hypothesis that a short-term tagging- or handling-related mortality occurred following release were moderately supported by data from wild fish and weakly supported by data from hatchery fish. Estimates of apparent survival of hatchery fish through the 276 km study area ranged from 0.412 (standard error [SE] 0.048) to 0.648 (SE 0.070), depending on the year, and represented an average of 0.790 per 100 km traveled. Estimates of apparent survival of wild fish through the study area were 0.645 (SE 0.058) in 2006 and 0.630 (SE 0.059) in 2009 and were nearly identical to the results from hatchery fish released on the same dates. The data and models examined supported positive effects of water temperature, river discharge, and fish weight as factors affecting apparent survival in the Klamath River upstream of the confluence with the Shasta River, but few of the variables examined were supported as factors affecting survival farther downstream. The effect of water temperature on apparent survival upstream of the Shasta River was greater than Iron Gate Dam discharge, which was greater than fish weight. The estimated effect on apparent survival between release and the Shasta River with each 1degree Celsius increase in water temperature was 1.4 times the effect of a 100 cubic feet per second increase in Iron Gate Dam discharge and 2.5 times the effect of a 1 gram increase in fish weight, and the effects of discharge and weight diminished at higher water temperatures up to the 17.91 degrees Celsius maximum present in the data examined. The rate of passage at the detection site near the confluence with the Shasta River was primarily affected by date of release, and water temperature was the only factor supported at the site near the confluence with the Scott River. Passage rates at sites downstream of the Scott River were affected by several of the variables examined, but the estimated effects were small and often imprecise. Results from this study indicate that discharge at Iron Gate Dam has a positive effect on apparent survival of yearling coho salmon in the Klamath River upstream of the Shasta River, but the effects are smaller than those of water temperature and are mediated by it. The results also support the use of hatchery fish as surrogates for wild fish in studies of apparent survival, but the available evidence suggests that study fish should be released well upstream of the area of interest, due to short-term differences in survival and migration behavior of hatchery and wild fish after release.
Discharge ratings for control gates at Mississippi River lock and dam 12, Bellevue, Iowa

USGS Publications Warehouse

Heinitz, Albert J.

1986-01-01

The water level of the navigation pools on the Mississippi River are maintained by the operation of tainter and roller gates at the locks and dams. Discharge ratings for the gates on Lock and Dam 12, at Bellevue, Iowa, were developed from current-meter discharge measurements made in the forebays of the gate structures. Methodology is given to accurately compute the gate openings of the tainter gates. Discharge coefficients, in equations that express discharge as a function of tailwater head , forebay head, and height of gate opening, were determined for conditions of submerged-orifice and fee-weir flow. A comparison of the rating discharges to the hydraulic-model rating discharges is given for submerged orifice flow for the tainter and roller gates.
All-optical switch and transistor gated by one stored photon.

PubMed

Chen, Wenlan; Beck, Kristin M; Bücker, Robert; Gullans, Michael; Lukin, Mikhail D; Tanji-Suzuki, Haruka; Vuletić, Vladan

2013-08-16

The realization of an all-optical transistor, in which one "gate" photon controls a "source" light beam, is a long-standing goal in optics. By stopping a light pulse in an atomic ensemble contained inside an optical resonator, we realized a device in which one stored gate photon controls the resonator transmission of subsequently applied source photons. A weak gate pulse induces bimodal transmission distribution, corresponding to zero and one gate photons. One stored gate photon produces fivefold source attenuation and can be retrieved from the atomic ensemble after switching more than one source photon. Without retrieval, one stored gate photon can switch several hundred source photons. With improved storage and retrieval efficiency, our work may enable various new applications, including photonic quantum gates and deterministic multiphoton entanglement.

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