A novel topology for a HEMT negative current mirror

A new solution for the implementation of a HEMT negative current source is presented. The topology can be also profitably employed as a current mirror and as an active load in high-gain MMICs voltage amplifiers. A small-signal model of the proposed circuit is developed which allows to find accurate expressions for the required transfer functions (i.e., the output impedance of the current source, and the current gain of the circuit when operated as a current mirror). Design examples using Philips PML ED02AH GaAs PHEMT process are provided. Spice simulations show that a 10- kW output impedance for the current source and a 35dB voltage gain for a differential pair loaded with the proposed current mirror are easily achieved

A Rasch analysis of the School-Related Well-being (SRW) scale: Measuring well-being in the transition from primary to secondary school

Within educational systems, promoting well-being is an essential objective along with traditional aims focused on students\u2019 learning. However, scarce attention has been devoted to school-related well-being in the transition from primary to lower secondary school, also for the paucity of brief instruments deputed to measure it. We assessed well-being at school for fourthgraders and seventh-graders, by adapting and validating the Italian version of the School-Related Well-Being (SRW) scale, using in sequence exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and Rasch analysis. Through the Rasch analysis, we transformed the SRW scale into an instrument that respects the properties of the fundamental measurement. We measured well-being and achievement emotions at time 1 and grades at time 2. The SRW scale correlated with another measure of well-being and with students\u2019 achievement emotions. Grade-level differences emerged, with a decrease of well-being that attested a maladaptive trend at increasing age; moreover, females reported higher well-being than males. Well-being at school was positively linked to achievement. Beyond its methodological relevance, this study highlights the need for developing interventions to support students in the transition from primary to lower secondary school, which is such a pivotal time in their learning path

A high speed oscillator-based truly random number source for cryptographic applications on a Smart Card IC

Special Issue on Cryptographic Hardware and Embedded System

An ultra-low-voltage class-AB OTA exploiting local CMFB and body-to-gate interface

In this work a novel bulk-driven (BD) ultra-low-voltage (ULV) class-AB operational transconductance amplifier (OTA) which exploits local common mode feedback (LCMFB) strategies to enhance performance and robustness against process, voltage and temperature (PVT) variations has been proposed. The amplifier exploits body-to-gate (B2G) interface to increase the slew rate and attain class-AB behaviour, whereas two pseudo-resistors have been employed to increase the common mode rejection ratio (CMRR). The architecture has been extensively tested through Monte Carlo and PVT simulations, results show that the amplifier is very robust in terms of gain-bandwidth-product (GBW), power consumption and slew rate. A wide comparison against state-of-the-art has pointed out that best small-signal figures of merit are attained and good large-signal performance is guaranteed, also when worst-case slew rate is considered

The societal relevance of communities in the COVID-19 era

Non peer reviewe

Assessment of bladder filling during prostate cancer radiation therapy with ultrasound and cone-beam CT

Prostate cancer patients undergoing external beam radiation therapy (EBRT) benefit from a full bladder to decrease bowel and bladder toxicity. Ultrasound may offer a proxy metric for evaluation, sparing CBCT dosing. Patients were prospectively enrolled pre-simulation from January 2017 to February 2018. Bladder volume was evaluated prior to RT using US daily and CBCT for three daily treatments and then weekly unless otherwise indicated. 29 patients completed median 40 days of RT, resulting in 478 CBCT and 1,099 US bladder volumes. 21 patients were treated to intact glands and 8 to the post-prostatectomy bed. Median patient age was 70 years. Bladder volume on CBCT and US positively correlated (r = 0.85), with average bladder volume for all patients of 162 mL versus 149 mL, respectively. Bladder volume during treatment was consistently lower than the volume at CT simulation (153 mL vs 194 mL, p<0.01) and progressively declined during treatment. Patients older than 70 years presented with lower average bladder volumes than those < 70 years (122 mL vs 208 mL, respectively, p<0.01). Patients with the highest agreement between CBCT and US (<10% variability) had higher average bladder volumes (192 mL vs 120 mL, p=0.01). US was found to be an accurate measure of bladder volume and may be used to monitor daily bladder volumes in patients being treated with radiation for prostate cancer

Choroid plexus tumours

Choroid plexus tumours are rare epithelial brain tumours and limited information is available regarding their biology and the best treatment. A meta-analysis was done to determine prognostic factors and the influence of various treatment modalities. A thorough review of the medical literature (1966–1998) revealed 566 well-documented choroid plexus tumours. These were entered into a database, which was analysed to determine prognostic factors and treatment modalities. Most patients with a supratentorial tumour were children, while the most common sites in adults were the fourth ventricle and the cerebellar pontine angle. Cerebellar pontine angle tumours were more frequently benign. Histology was the most important prognostic factor, as one, five, and 10-year projected survival rates were 90, 81, and 77% in choroid plexus-papilloma (n=353) compared to only 71, 41, and 35% in choroid plexus-carcinoma respectively (P<0.0005). Surgery was prognostically relevant for both choroid plexus-papilloma (P=0.0005) and choroid plexus-carcinoma (P=0.0001). Radiotherapy was associated with significantly better survival in choroid plexus-carcinomas. Eight of 22 documented choroid plexus-carcinomas responded to chemotherapy. Relapse after primary treatment was a poor prognostic factor in choroid plexus-carcinoma patients but not in choroid plexus-papilloma patients. Treatment of choroid plexus tumours should start with radical surgical resection. This should be followed by adjuvant treatment in case of choroid plexus-carcinoma, and a ‘wait and see’ approach in choroid plexus-papilloma

A life course approach to injury prevention: a "lens and telescope" conceptual model

<p>Abstract</p> <p>Background</p> <p>Although life course epidemiology is increasingly employed to conceptualize the determinants of health, the implications of this approach for strategies to reduce the burden of injuries have received little recognition to date.</p> <p>Methods</p> <p>The authors reviewed core injury concepts and the principles of the life course approach. Based on this understanding, a conceptual model was developed, to provide a holistic view of the mechanisms that underlie the accumulation of injury risk and their consequences over the life course.</p> <p>Results</p> <p>A "lens and telescope" model is proposed that particularly draws on (a) the extended temporal dimension inherent in the life course approach, with links between exposures and outcomes that span many years, or even generations, and (b) an ecological perspective, according to which the contexts in which individuals live are critical, as are changes in those contexts over time.</p> <p>Conclusions</p> <p>By explicitly examining longer-term, intergenerational and ecological perspectives, life course concepts can inform and strengthen traditional approaches to injury prevention and control that have a strong focus on proximal factors. The model proposed also serves as a tool to identify intervention strategies that have co-benefits for other areas of health.</p