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Large-signal modeling of Gallium Nitride (GaN) based high electron mobility transistors (HEMTs) demands a proper description of trapping effects. In this paper, a new, simplified yet accurate drain-lag description is proposed, enhancing the simulation accuracy and the extraction flow of the physics-based compact model ASM-HEMT. The present study investigates the impact of drain lag on specific physical phenomena, focusing on the relation between trap states, surface-potential calculations, and electron transport properties. It is supplemented with a revised extraction procedure, minimizing the required measurements, thereby the undesired consequences of several passes on the same device, using pulsed I-V and pulsed S-parameters only, and approaches for efficient and accurate simulation results. We show that the proposed trap model is a determinative tool for simulating both small and large-signal behavior predicting precisely S-parameters and load-pull performance.
One of the fundamental requirements for dual purpose casks, which are used for the transport and interim storage of spent fuel assemblies, is the safe removal of the resulting decay heat. To ensure this the temperature fields are determined using numerical methods. However, their modelling is complex and the computation time-consuming.
In order to accelerate this thermal assessment, we have developed z88ENSI, an independent simulation tool based on finite element analysis. With regard to the modelling, various parameters can be varied quickly with our newly designed mesh manipulation procedure. Concerning the computation time, we developed and implemented an approach for calculating three-dimensional temperature fields, based on an already existing two-dimensional method which lacked precision. We accelerate the calculation by using extended thermal gap constraints, which depict the thermal behaviour of the non-meshed, gas-filled gaps inside the cask. We validate the results of our calculation tool by comparing them with those generated with Ansys. The results of the comparison temperatures differ between −0.8% and 3.7%. The speedup of z88ENSI for the specific validation setting is between 6.9 and 15.0.
Nosocomial transmission of influenza is a major concern for infection control. We aimed to dissect transmission dynamics of influenza, including asymptomatic transmission events, in acute care.
Prospective surveillance study during 2 influenza seasons.
Volunteer sample of inpatients on medical wards and healthcare workers (HCWs).
Participants provided daily illness diaries and nasal swabs for influenza A and B detection and whole-genome sequencing for phylogenetic analyses. Contacts between study participants were tracked. Secondary influenza attack rates were calculated based on spatial and temporal proximity and phylogenetic evidence for transmission.
In total, 152 HCWs and 542 inpatients were included; 16 HCWs (10.5%) and 19 inpatients (3.5%) tested positive for influenza on 109 study days. Study participants had symptoms of disease on most of the days they tested positive for influenza (83.1% and 91.9% for HCWs and inpatients, respectively). Also, 11(15.5%) of 71 influenza-positive swabs among HCWs and 3 (7.9%) of 38 influenza-positive swabs among inpatients were collected on days without symptoms; 2 (12.5%) of 16 HCWs and 2 (10.5%) of 19 inpatients remained fully asymptomatic. The secondary attack rate was low: we recorded 1 transmission event over 159 contact days (0.6%) that originated from a symptomatic case. No transmission event occurred in 61 monitored days of contacts with asymptomatic influenza-positive individuals.
Influenza in acute care is common, and individuals regularly shed influenza virus without harboring symptoms. Nevertheless, both symptomatic and asymptomatic transmission events proved rare. We suggest that healthcare-associated influenza prevention strategies that are based on preseason vaccination and barrier precautions for symptomatic individuals seem to be effective.
To assess influenza symptoms, adherence to mask use recommendations, absenteesm and presenteeism in acute care healthcare workers (HCWs) during influenza epidemics.
The TransFLUas influenza transmission study in acute healthcare prospectively followed HCWs prospectively over 2 consecutive influenza seasons. Symptom diaries asking for respiratory symptoms and adherence with mask use recommendations were recorded on a daily basis, and study participants provided midturbinate nasal swabs for influenza testing.
In total, 152 HCWs (65.8% nurses and 13.2% physicians) were included: 89.1% of study participants reported at least 1 influenza symptom during their study season and 77.8% suffered from respiratory symptoms. Also, 28.3% of HCW missed at least 1 working day during the study period: 82.6% of these days were missed because of symptoms of influenza illness. Of all participating HCWs, 67.9% worked with symptoms of influenza infection on 8.8% of study days. On 0.3% of study days, symptomatic HCWs were shedding influenza virus while at work. Among HCWs with respiratory symptoms, 74.1% adhered to the policy to wear a mask at work on 59.1% of days with respiratory symptoms.
Respiratory disease is frequent among HCWs and imposes a significant economic burden on hospitals due to the number of working days lost. Presenteesm with respiratory illness, including influenza, is also frequent and poses a risk for patients and staff.
The COVID-19 pandemic has raised significant concerns for population mental health and the effective provision of mental health services in the light of increased demands and barriers to service delivery . Particular attention is being directed toward the possible neuropsychiatric sequelae of both COVID-19 and of the stringent societal mitigation steps deployed by national governments, concerns that are informed by historical increases in the incidence of psychotic disorders following influenza pandemics . However, so far there has been scant attention paid to other important areas of psychiatry during COVID-19, including medico-legal aspects and human rights. In this paper, we discuss the legal implications for psychiatry of the COVID-19 pandemic and report a novel situation in which psychiatric patients may experience diminution of their statutory protections. We believe that this represents a paradigm shift in psychiatric care and that the consideration of the fundamental rights of psychiatric patients as “less important” than infection control measures compel mental health professionals to “advocate for … patients and their caregivers” in this time of crisis .
Accurate estimations of ice thickness and volume are indispensable for ice flow modelling, hydrological forecasts and sea-level rise projections. We present a new ice thickness estimation model based on a mass-conserving forward model and a Bayesian inversion scheme. The forward model calculates flux in an elevation-band flow-line model, and translates this into ice thickness and surface ice speed using a shallow ice formulation. Both ice thickness and speed are then extrapolated to the map plane. The model assimilates observations of ice thickness and speed using a Bayesian scheme implemented with a Markov chain Monte Carlo method, which calculates estimates of ice thickness and their error. We illustrate the model's capabilities by applying it to a mountain glacier, validate the model using 733 glaciers from four regions with ice thickness measurements, and demonstrate that the model can be used for large-scale studies by fitting it to over 30 000 glaciers from five regions. The results show that the model performs best when a few thickness observations are available; that the proposed scheme by which parameter-knowledge from a set of glaciers is transferred to others works but has room for improvements; and that the inferred regional ice volumes are consistent with recent estimates.
Early-life environmental and nutritional exposures are considered to contribute to the differences in cardiovascular disease (CVD) burden. Among sub-Saharan African populations, the association between markers of early-life exposures such as leg length and sitting height and CVD risk is yet to be investigated. This study assessed the association between leg length, sitting height, and estimated 10-year atherosclerotic cardiovascular disease (ASCVD) risk among Ghanaian-born populations in Europe and Ghana. We constructed sex-specific quintiles for sitting height and leg length for 3250 participants aged 40–70 years (mean age 52 years; men 39.6%; women 60.4%) in the cross-sectional multicenter Research on Diabetes and Obesity among African Migrants study. Ten-year risk of ASCVD was estimated using the Pooled Cohort Equations; risk ≥7.5% was defined as “elevated” CVD risk. Prevalence ratios (PR) were estimated to determine the associations between sitting height, leg length, and estimated 10-year ASCVD risk. For both men and women, mean sitting height and leg length were highest in Europe and lowest in rural Ghana. Sitting height was inversely associated with 10-year ASCVD risk among all women (PR for 1 standard deviation increase of sitting height: 0.75; 95% confidence interval: 0.67, 0.85). Among men, an inverse association between sitting height and 10-year ASCVD risk was significant on adjustment for study site, adult, and parental education but attenuated when further adjusted for height. No association was found between leg length and estimated 10-year ASCVD risk. Early-life and childhood exposures that influence sitting height could be the important determinants of ASCVD risk in this adult population.
Accurately and efficiently modeling the drain-lag effects is crucial in nonlinear large-signal modeling for Gallium Nitride high electron mobility transistors. In this paper, a simplified yet accurate drain-lag model based on an industry standard large-signal model, i.e., the Chalmers (Angelov) model, extracted by means of pulsed S-parameter measurements, is presented. Instead of a complex nonlinear drain-lag description, only four constant parameters of the proposed drain-lag model need to be determined to accurately describe the large impacts of the drain-lag effects, e.g., drain-source current slump, typical kink observed in pulsed IV curves, and degradation of the output power. The extraction procedure of the parameters is based on pulsed S-parameter measurements, which allow to freeze traps and isolate the trapping effects from self-heating. It is also shown that the model can very accurately predict the load pull performance over a wide range of drain bias voltages. Finally, the large-signal network analyzer measurements at low frequency are used to further verify the proposed drain-lag model in the prediction of the output current in time domain under large-signal condition.
The family Peltulaceae is currently composed of the three genera Peltula, Phyllopeltula and Neoheppia. The last two genera, both with two species, are distinguished from Peltula only by a small number of morphological characters. The morphology of the genus Peltula varies from peltate-umbilicate thalli to squamulose-semifruticose or squamulose-compound types, as well as subfoliose-compound and crustose types. All types have an upper epinecral layer and possess medullary cavities of various sizes; a lower cortex is normally present but is usually not developed in the subfoliose and crustose types. The genera Neoheppia and Phyllopeltula differ from the common Peltula morphology by crustose-areolate and subfoliose-compound thalli, respectively. Both Neoheppia and Phyllopeltula are additionally characterized by the absence of medullary cavities and lower cortices. To investigate the phylogenetic validity of Phyllopeltula and Neoheppia, we sequenced six loci from representatives of these two genera together with 37 species from Peltula. Despite the relatively high amount of conflict among loci, the results clearly indicate that both Phyllopeltula and Neoheppia are not monophyletic, and are nested within the genus Peltula. Consequently, we subsumed species of these two genera within the genus Peltula.
Web-based interventions are effective in reducing depression. However, the evidence for the cost-effectiveness of these interventions is scarce.
The aim is to assess the cost-effectiveness of a web-based intervention (GET.ON M.E.D.) for individuals with diabetes and comorbid depression compared with an active control group receiving web-based psychoeducation.
We conducted a cost-effectiveness analysis with treatment response as the outcome and a cost-utility analysis with quality-adjusted life-years (QALYs) alongside a randomised controlled trial with 260 participants.
At a willingness-to-pay ceiling of €5000 for a treatment response, the intervention has a 97% probability of being regarded as cost-effective compared with the active control group. If society is willing to pay €14 000 for an additional QALY, the intervention has a 51% probability of being cost-effective.
This web-based intervention for individuals with diabetes and comorbid depression demonstrated a high probability of being cost-effective compared with an active control group.
Declaration of interest
S.N., D.D.E., D.L., M.B. and B.F. are stakeholders of the Institute for Online Health Trainings, which aims to transfer scientific knowledge related to this research into routine healthcare.
Timo-Kolja Pförtner, Research Assistant At The Institute Of Medical Sociology, Health Services Research, And Rehabilitation Science (IMVR) Of The University Of Cologne,
Frank J. Elgar, Associate Professor of Psychiatry at the Institute for Health and Social Policy at McGill University,
Katharina Rathmann, Interim Professor for Sociology of Rehabilitation and Inclusion at the Faculty of Rehabilitation Sciences at the Technical University Dortmund,
Matthias Richter, Professor and Director of the Institute of Medical Sociology (IMS) at the Martin Luther University Halle- Wittenberg
The recent economic recession, documented to have lasted from December 2007 to June 2009 and labeled as the “Great Recession,” has affected prospects for financial security and health among populations of many countries. Recent research about the health impacts of the Great Recession has predominantly focused on adults. This chapter explores the extent to which the Great Recession relates to changes in health and socioeconomic health inequalities in adolescents (aged 11 to 15 years) in Europe, North America, and Israel. Using data from the Health Behaviour in School-aged Children (HBSC) study that were collected before the onset of the recent recession (in 2005/2006) and a few years after it began (in 2009/2010), we found that changes in both national prevalence rates and socioeconomic inequalities in psychological health complaints were mostly modest during the Great Recession. Moreover, the effects of the Great Recession, indicated by change rates in youth and adult unemployment between 2005/2006 and 2009/2010, did not significantly correlate to psychological health complaints and socioeconomic inequalities in psychological health complaints. From a cross-national perspective, health and socioeconomic health inequalities in adolescence appear to have been unaffected by the Great Recession.
The recent economic recession, documented to have lasted from December 2007 to June 2009 and labeled as “Great Recession,” has affected prospects for financial security and health among populations of many countries. Like economic downturns in the past, the recent recession threatens living conditions and individual well-being through the anticipated and actual losses of economic and social security (Burgard, Ailshire, and Kalousova 2013; Catalano et al. 2011; Karanikolos et al. 2013; Modreck et al. 2013; Stuckler and Basu 2013; Suhrcke and Stuckler 2012). A number of studies on adults have found detrimental impacts of the recent recession on mental and physical health as well as on different health behaviors. Its onset in 2007 was accompanied by a rise in suicides in Greece (Economou et al. 2011), Italy (De Vogli, Marmot, and Stuckler 2013a, 2013b; De Vogli, Vieno, and Lenzi 2014; Pompili et al. 2014), Spain (López Bernal et al. 2013), the United Kingdom (Barr et al. 2012), the United States (Reeves et al. 2012), and across Europe (Karanikolos et al. 2013; Reeves, McKee, and Stuckler 2014; Stuckler et al. 2009) and the world (Chang et al. 2013).
Outer-halo globular clusters show large half-light radii and flat stellar mass functions, depleted in low-mass stars. Using N-body simulations of globular clusters on eccentric orbits within a Milky Way-like potential, we show how a cluster’s half-mass radius and its mass function develop over time. The slope of the central mass function flattens proportionally to the amount of mass a cluster has lost, and the half-mass radius grows to a size proportional to the average strength of the tidal field. The main driver of these processes is mass segregation of dark remnants. We conclude that the extended, depleted clusters observed in the Milky Way must have had small half-mass radii in the past, and that they expanded due to the weak tidal field they spend most of their lifetime in. Moreover, their mass functions must have been steeper in the past but flattened significantly as a cause of mass segregation and tidal mass loss.
There is epidemiological evidence for associations between dietary patterns and type 2 diabetes. However, for sub-Saharan Africa, information on dietary patterns and their contribution to diabetes is lacking. The aim of the present study was to identify dietary patterns and their associations with type 2 diabetes in an urban Ghanaian population. In a hospital-based case–control study on risk factors for type 2 diabetes in Kumasi, a FFQ was administered to 675 controls and 542 cases. Dietary patterns were identified by using factor analysis including thirty-three food items. Logistic regression was used to evaluate the associations of dietary patterns with type 2 diabetes. Overall, two dietary patterns were identified: (1) a ‘purchase’ dietary pattern which positively correlated with the consumption of sweets, rice, meat, fruits and vegetables and (2) a ‘traditional’ dietary pattern that correlated with the intake of fruits, plantain, green leafy vegetables, fish, fermented maize products and palm oil. In the highest quintile of the ‘purchase’ dietary pattern, participants were younger, leaner and of higher socio-economic status than those in the lower quintiles. In contrast, participants in the highest quintile of the ‘traditional’ dietary pattern were older, heavier and more deprived compared with those in the lower quintiles. In the multivariate model, the ‘purchase’ dietary pattern was inversely associated with type 2 diabetes (OR per 1 sd 0·41, 95 % CI 0·33, 0·50); the ‘traditional’ dietary pattern increased the odds of diabetes per 1 sd by 54 % (95 % CI 1·35, 1·81). In conclusion, two diverse dietary patterns were identified and associated with type 2 diabetes in urban Ghana. The determinants of pattern adherence require further investigation.
In this paper, the small- and large-signal modeling of InP heterojunction bipolar transistors (HBTs) in transferred substrate (TS) technology is investigated. The small-signal equivalent circuit parameters for TS-HBTs in two-terminal and three-terminal configurations are determined by employing a direct parameter extraction methodology dedicated to III–V based HBTs. It is shown that the modeling of measured S-parameters can be improved in the millimeter-wave frequency range by augmenting the small-signal model with a description of AC current crowding. The extracted elements of the small-signal model structure are employed as a starting point for the extraction of a large-signal model. The developed large-signal model for the TS-HBTs accurately predicts the DC over temperature and small-signal performance over bias as well as the large-signal performance at millimeter-wave frequencies.
Package-induced failures for BEOL interconnects in sub-45nm technology nodes have drawn attention to the great silicon and packaging integration challenges introduced by the weak mechanical properties of ULK-containing metallization elements. Empirical data and modeling studies for a range of silicon and packaging factors at 20nm node reveal fundamental insights into susceptibility to damage and approaches for recovery. Analysis of increase in degradation as BEOL layouts evolve to finer dimensions points to understanding of changes that will enable continued device scaling.
The temperature dependence of diffusion length, lifetime, and diffusivity of the free exciton is measured in a commercial ZnO-substrate as well as in an epitaxial ZnO quantum well using nm-spatially and ps-time-resolved cathodoluminescence spectroscopy. The characteristic temperature dependence of the exciton mobility gives information of the underlying excitonic scattering processes. Since excitons are neutral particles, scattering at ionized impurities should be not effective. On both samples, with decreasing temperature, the diffusion lengths, lifetimes, and diffusivity give rise to a monotonic increase of the excitonic mobility. Two different methods will be discussed and are used for determining the excitonic transport parameters. On the one hand, we are able to perform completely pulsed excitation experiments, and on the other hand, a combination of cw excitation and pulsed excitation in two independent measurements is used.
Local reservoir ages are often estimated from the difference between the radiocarbon ages of aquatic material and associated terrestrial samples for which no reservoir effect is expected. Frequently, the selected aquatic material consists of bivalve shells that are typically well preserved in the archaeological record. For instance, large shell middens attest to the importance of mussel consumption at both coastal and inland sites. However, different physiological mechanisms associated with tissue and shell growth may result in differences in reservoir effects between the surviving component (shell) and the component relevant to dietary reservoir effects in consumers (tissue). The current study examines bivalve tissue-shell age differences both from freshwater and marine contexts close to archaeological sites where human consumption of mollusks has been attested. Results exhibited significant 14C age differences between bivalve tissue and shell in a freshwater context. In a marine context, no significant bivalve tissue-shell age differences were observed. The results also showed that riverine and lacustrine shells show large and variable freshwater reservoir effects. The results have important implications for establishing local reservoir effects especially in a freshwater environment. For good a priori knowledge of expected 14C differences in organic and inorganic water, carbon is thus necessary. Furthermore, the high variability in freshwater shell 14C ages implies the need for representative sampling from the archaeological record.