2,168 research outputs found
Treatment as prevention for hepatitis C virus in Pakistan: Mathematical modelling projections
No full textObjective Direct-Acting antivirals have opened an opportunity for controlling hepatitis C virus (HCV) infection in Pakistan, where 10% of the global infection burden is found. We aimed to evaluate the implications of five treatment programme scenarios for HCV treatment as prevention (HCV-TasP) in Pakistan. Design An age-structured mathematical model was used to evaluate programme impact using epidemiological and programme indicators. Setting Total Pakistan population. Participants Total Pakistan HCV-infected population. Interventions HCV treatment programme scenarios from 2018 up to 2030. Results By 2030 across the five HCV-TasP scenarios, 0.6-7.3 million treatments were administered, treatment coverage reached between 3.7% and 98.7%, prevalence of chronic infection reached 2.4%-0.03%, incidence reduction ranged between 41% and 99%, program-Attributed reduction in incidence rate ranged between 7.2% and 98.5% and number of averted infections ranged between 126 221 and 750 547. Annual incidence rate reduction in the first decade of the programme was around 6%-18%. Number of treatments needed to prevent one new infection ranged between 4.7-9.8, at a drug cost of about US900. Cost of the programme by 2030, in the most ambitious elimination scenario, reached US708 million. Stipulated WHO target for 2030 cannot be accomplished without scaling up treatment to 490 000 per year, and maintaining it for a decade. Conclusion HCV-TasP is a highly impactful and potent approach to control Pakistan's HCV epidemic and achieve elimination by 2030This publication was made possible by NPRP grant number 9-040-3-008 from the Qatar National Research Fund (a member of Qatar Foundation). The findings achieved herein are solely the responsibility of the authors. The authors are also grateful for support provided by the Biostatistics, Epidemiology, and Biomathematics Research Core at Weill Cornell Medicine-Qatar. Competing interests None declared.Scopu
Characterizing the transitioning epidemiology of herpes simplex virus type 1 in the USA: Model-based predictions
No full textBackground: Herpes simplex virus type 1 (HSV-1) is a prevalent lifelong infection that appears to be undergoing an epidemiologic transition in the United States (US). Using an analytical approach, this study aimed to characterize HSV-1 transitioning epidemiology and estimate its epidemiologic indicators, past, present, and future. Methods: An age-structured mathematical model was developed to describe HSV-1 transmission through oral and sexual modes of transmission. The model was fitted to the National Health and Nutrition Examination Surveys, 1976-2016 data series. Results: HSV-1 seroprevalence was projected to decline from 61.5% in 1970 to 54.8% in 2018, 48.5% in 2050, and 42.0% in 2100. In 30% for those aged 0-19 years, but 60. Meanwhile, the number of new infections per year (oral and genital) was persistent at 2,762,000 in 1970, 2,941,000 in 2018, 2,933,000 in 2050, and 2,960,000 in 2100. Of this total, genital acquisitions contributed 252,000 infections in 1970, 410,000 in 2018, 478,000 in 2050, and 440,000 in 2100 - a quarter of which are symptomatic with clinical manifestations. For those aged 15-49 years, nearly 25% of incident infections are genital. Most genital acquisitions (> 85%) were due to oral-to-genital transmission through oral sex, as opposed to genital-to-genital transmission through sexual intercourse. Conclusion: HSV-1 epidemiology is undergoing a remarkable transition in the US, with less exposure in childhood and more in adulthood, and less oral but more genital acquisition. HSV-1 will persist as a widely prevalent infection, with ever-increasing genital disease burden.This publication was made possible by NPRP grant number 9-040-3-008 from the Qatar National Research Fund (a member of Qatar Foundation). The findings achieved herein are solely the responsibility of the authors. The authors are also grateful for pilot funding provided by the Biomedical Research Program and infrastructure support provided by the Biostatistics, Epidemiology, and Biomathematics Research Core, both at Weill Cornell Medicine in Qatar.Scopu
A 0.25mm<sup>2</sup> Resistor-Based Temperature Sensor with an Inaccuracy of 0.12°C (3σ) from -55°C to 125°C and a Resolution FOM of 32fJK<sup>2</sup>
No full textTemperature sensors based on Wheatstone bridges, e.g. [1,2], have recently achieved higher resolution and greater energy efficiency than conventional BJT-based sensors [3]. However, this comes at the expense of area, making them less attractive in industrial applications. This paper presents a Wheatstone-bridge sensor that uses a zoom-ADC architecture to reduce area (by 3x over [2]) and achieve state-of-the-art energy-efficiency for an integrated temperature sensor. After a 1st-order fit and a systematic non-linearity correction [2,4], it also achieves state-of-the-art inaccuracy: 0.12°C (3σ) over the full military temperature range (-55°C to 125°C).Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
A CMOS Dual-RC frequency reference with ±250ppm inaccuracy from -45°C to 85°C
No full textTo comply with wired communication standards such as USB, SATA and PCI/PCI-E, systems-on-chip require frequency references with better than 300ppm accuracy. LC-based references achieve 100ppm accuracy [1], but suffer from high power consumption (∼20mW). Thermal diffusivity (TD) references require less power (∼2mW), at the expense of less accuracy (1000ppm) [2]. RC-based references offer the lowest power consumption, but their accuracy is typically limited to ∼0.1% [3]. In RC relaxation oscillators, comparator offset and delay are the major sources of inaccuracy [4,5]. References based on frequency-locked loops (FLLs) circumvent these by locking an oscillator's frequency to the time-constant of an RC filter, but their accuracy is then limited by the nonlinear temperature dependency of on-chip resistors [3,6].Session 3.3 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Instrumentation(OLD)Applied Quantum ArchitecturesMicroelectronic
A twenty-five-year-old eucalyptus tree in a eucalyptus grove at the L.J. Rose Ranch, ca.1900
No full textPhotograph of a twenty-five-year-old eucalyptus tree in a eucalyptus grove at the L.J. Rose Ranch, ca.1900. The barks on the trunk is pealing off to reveal the smooth surface underneath. The ground is littered with fallen leaves. Shrubs and grass cover the area in the background where other trees stand.; "Under the ownership of Leonard John Rose, the Sunny Slope Ranch live location was a showplace of orchards and vineyards, drawing as many as two to three hundred visitors a day. Rose learned how to grow grapes without irrigation, and the ranch became known for its brandy and fine wines." -- unknown author.; "The Old Grapevine holds a small segment of the original vine whose trellised branches once covered 10,000 square feet. It was a popular local gathering place where refreshments were served under the vine. Started as a cutting from the "Mother Vine" at the Mission, many local vineyards began from cuttings of this vine. L.J. Rose of Sunnyslope Ranch, just north and east of San Gabriel, started with such cuttings and grafted on many varieties of grapes new to this area. He later helped begin many a vineyard in Northern California. The San Gabriel Winery was among the worlds largest in the late 1800's, until a blight wiped out the vineyards and oranges became the main agricultural crop of the area. Today the park is once again a popular place for weddings, parties and social gatherings." -- unknown author
Herpes simplex virus type 1 epidemiology in Latin America and the Caribbean: Systematic review and meta-analytics
No full textObjectives To investigate the epidemiology of herpes simplex virus type 1 (HSV-1) in Latin America and the Caribbean. Methods Systematic review and meta-analytics guided by the Cochrane Collaboration Handbook and reported following the PRISMA guidelines. Results Thirty-three relevant reports were identified including 35 overall (and 95 stratified) seroprevalence measures, and five and nine proportions of virus isolation in genital ulcer disease (GUD) and in genital herpes, respectively. Pooled mean seroprevalence was 57.2% (95% CI: 49.7-64.6%) among children and 88.4% (95% CI: 85.2-91.2%) among adults. Pooled mean seroprevalence was lowest at 49.7% (95% CI: 42.8-56.6%) in those aged ?10, followed by 77.8% (95% CI: 67.9-84.8%) in those aged 10-20, 82.8% (95% CI: 73.1-90.8%) in those aged 20-30, 92.5% (95% CI: 89.4-95.1%) in those aged 30-40, and 94.2% (95% CI: 92.7-95.5%) in those aged ?40. Age was the strongest source of heterogeneity in seroprevalence, explaining 54% of variation. Evidence was found for seroprevalence decline over time. Pooled mean proportion of HSV-1 isolation was 0.9% (95% CI: 0.0-3.6%) in GUD and 10.9% (95% CI: 4.4-19.4%) in genital herpes. Conclusions HSV-1 is a widely prevalent infection in this region, but its epidemiology may be slowly transitioning, with still limited contribution for HSV-1 in genital herpes.Scopu
Hepatitis C virus infection spontaneous clearance: Has it been underestimated?
No full textObjectives: Hepatitis C virus (HCV) clearance rate (fclearance) is defined as the proportion of infected persons who will spontaneously clear their infection after acute infection. We aimed to estimate fclearance using a novel approach that avoids limitations in existing estimates, and to clarify the link between fclearance and HCV viremic rate?the latter being the proportion of RNA positivity among those antibody positive. Methods: A mathematical model was developed to describe HCV transmission. fclearance was estimated by fitting the model to probability-based and nationally representative population-based data for Egypt (Egypt 2008 and Egypt 2015) and USA (NHANES A and NHANES B). Uncertainty and sensitivity analyses were conducted. Results: fclearance was estimated at 39.9% (95% uncertainty interval (UI): 34.3%?46.4%) and 33.5% (95% UI: 29.2%?38.3%) for Egypt 2008 and Egypt 2015 data, respectively; and at 29.6% (23.0%?37.1%) and 39.9% (31.2%?51.0%) for NHANES A and NHANES B data, respectively. fclearance was found related to HCV viremic rate through (approximately) the formula fclearance = 1.16 (1 ? HCV viremic rate). HCV viremic rate was higher with higher risk of HCV exposure. Robustness of results was demonstrated in uncertainty and sensitivity analyses. Conclusion: One-third of HCV-infected persons clear their infection spontaneously, higher than earlier estimates?the immune-system capacity to clear HCV infection may have been underestimated.The authors are thankful for The Demographic and Health Surveys Program and for the National Health and Nutrition Examination Survey for putting the country-specific demographic and health data in the service of science, and for the United States Agency for International Development and the Centers for Disease Control and Prevention, among other donors, supporting these initiatives.Scopu
Failure and Delamination in Microelectronic Packages
No full textThin layers of dissimilar materials are used in most microelectronic components in order to achieve special functional requirements. Generally, the interface between two adjacent materials forms a weak link, not only because of the relatively low delamination strength, but also because of the existing mismatch in thermo-mechanical properties, such as Young’s modulus, coefficient of thermal expansion, hygro-swelling, and vapor pressure induced expansion. Residual stresses from the production processes and initial strains due to the changing thermal and humidity conditions together with acting mechanical loading form the crack driving factors for interface delamination. Failure of interface induces decreased reliability of microelectronic components. Nowadays, interfacial delamination forms one of the key reliability issues in the microelectronic industry and therefore is getting more and more attention. The analysis of a laminate structure with a crack along the interface is central to the characterization of the delamination toughness. The delamination toughness is highly dependent to temperature, moisture and mode mixity. In recent years, several studies were directed at the determination of the delamination behavior of Cu-EMC interfaces. In the event that moisture sensitivity was included in these studies, the temperature had to be limited to below 100oC. This limitation reduces the applicability of the toughness data obtained in a number of reliability studies of micro-electronic components. This is due to the fact that, in preconditioned (humid) micro-electronic components the interface delamination often occurs above this temperature limit. In many cases the damage is initiated during heating up in subsequent production steps, where temperatures can reach far above 100oC. Therefore the present research focuses on interface delamination measurements, especially interested in harsh environment (humidity combined with temperatures above the 100oC limit). In this thesis the thermal-mechanical properties of epoxy molding compounds in dry conditions are first investigated. The coefficient of thermal expansion and bulk modulus were measured via a dilatometer (PVT apparatus). DMA experiments in relaxation mode as well as in multi frequency mode were employed for obtaining the viscoelastic master curve and corresponding shift factors. Secondly, the thermo-mechanical properties of EMC during cure were studied. The volumetric contraction of the material during the curing period was measured via a PVT test. Furthermore the increasing shear modulus of the EMC because of the progressing cure was established through DMA experiments. For the dry state, the previous two-material characterization steps are sufficient to be able to interpret the measurement results of delamination tests via FEM simulation. For the humid state with T> 100 °C, in the delamination measurements the effect of (trapped) steam at the interface should be compensated by performing the measurements in a pressure chamber. Therefore, in a third step a pressure vessel surrounding the delamination test setup is designed and built. For the sake of simplicity the humid delamination measurements with T> 100 °C were only performed under full steam pressure (=relative humidity is 100%). The functionality of the setup has been verified by the measurement of the viscoelastic creep compliance of an EMC in dry state and to compare this with the result from measurements obtained from a commercially available measurement instrument. In order to be able to perform delamination measurements a mixed-mode bending setup is installed in the pressure vessel. Interfacial delamination measurements for a EMC-Cu lead frame interface (as obtained from a real production process) are subsequently performed for dry conditions as well as under pressurized steam conditions(= relative humidity 100%). A (I / II) mixed mode mechanical load is applied to the test sample, in which the initial stress state due to the manufacturing and the steam pressure (relative humidity 100%) is already present, in order to initiate and propagate the delamination. In conclusion: This dissertation shows that the temperature, the mix mode and the humidity under these conditions (T> 100 °C and 100% relative humidity) results in a significant effect on the delamination properties of interfaces. As far as known to the author, here for the first time a good insight on the impact of this harsh environment on the delamination properties is presented.Precision and Microsystems EngineeringMechanical, Maritime and Materials Engineerin
A 280μW dynamic-zoom ADC with 120dB DR and 118dB SNDR in 1kHz BW
No full textMicro-power ADCs with high linearity and dynamic range (DR) are required in several applications, such as smart sensors, biomedical imaging, and portable instrumentation. Since the signals of interest are then often small (tens of μν) and slow (<1kHz BW), such ADCs should also exhibit low offset and flicker noise. Noise-shaping SAR [1] and incremental ADCs [2] have been proposed for such applications, but their DR is limited to about 100dB. Although the ΔΣ modulator (ΔΣM) proposed in [3] achieves 136dB DR, it is at the expense of high power consumption (12.7mW). The incremental zoom ADC proposed in [4] combines a coarse SAR ADC and a fine ΔΣ ADC to efficiently achieve 119.8dB DR, but is limited to DC signals. The dynamic zoom ADC in [5] solves this problem, but requires external filtering to cope with out-of-band interference. This paper describes an interferer-robust dynamic zoom ADC that consumes 280μW while achieving 120.3dB DR and 118.1dB SNDR in 1kHz BW, resulting in a Schreier FoM of 185.8dB. It also achieves a maximum offset of 30μν and a 1/f corner of 7Hz. These advances are achieved by the combination of dynamic error-correction techniques, an asynchronous SAR ADC and a fully differential inverter-based ΔΣ ADC.Session 14.5 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Instrumentation(OLD)Applied Quantum ArchitecturesMicroelectronic
L.J. Emory Publishing Co.: Expansion to U.S. Regional Midwest and The Netherlands
No full textNational bestselling author Serena B. Miller owns the rights to her published works in Amish fiction, historical romance, mystery and children’s works. The L.J. Emory publishing company partnered with a marketing class in an agency project to develop marketing research instruments. The company deployed the instruments, gathered the data and approached the SSU Marketing program in the School of Business for participation in a second agency project to use the data to build a strategic plan. BUMK 4000 Marketing Management students evaluated the data and presented a package and live proposal to the company owners suggesting new ways to expand in the U.S. Midwest and a pilot project to expand internationally, targeting The Netherlands. The proposal included sample social media posts, email drip campaign messages and related promotional materials in English and Dutch
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