Non-Linear Inductors Characterization in Real Operating Conditions for Power Density Optimization in SMPS

The exploitation of power inductors outside their linear region in switching converters can be achieved by raising the current until a decrease in the inductance can be noticed. This allows using a smaller magnetic core, increasing the power density of the converter. On the other hand, a detailed description of the magnetization curve including the temperature is required. Since this information is often not included in the inductor’s datasheets, this paper shows how to identify the behavior of an inductor when it is operated up to saturation and its temperature rises. In order to characterize the inductor in real operating conditions, a dedicated measurement rig was developed. It consists of a switching converter that encompasses the inductor under test and is controlled by a virtual instrument developed in LabVIEW. The characterization system was tested by retrieving the inductance and the magnetization curves vs. current for two commercial inductors at core temperatures up to 105 °C. The magnetic core was then characterized by the saturation current vs. inductance, obtaining an expression for the whole family of inductors sharing the same core. Finally, we experimentally analyzed the thermal transient of the inductors in operating conditions, confirming the fundamental role of the temperature in changing the current profiles and the core saturation condition

Discovering the Repeatome of Five Species Belonging to the Asteraceae Family: A Computational Study

Genome divergence by repeat proliferation and/or loss is a process that plays a crucial role in species evolution. Nevertheless, knowledge of the variability related to repeat proliferation among species of the same family is still limited. Considering the importance of the Asteraceae family, here we present a first contribution towards the metarepeatome of five Asteraceae species. A comprehensive picture of the repetitive components of all genomes was obtained by genome skimming with Illumina sequence reads and by analyzing a pool of full-length long terminal repeat retrotransposons (LTR-REs). Genome skimming allowed us to estimate the abundance and variability of repetitive components. The structure of the metagenome of the selected species was composed of 67% repetitive sequences, of which LTR-REs represented the bulk of annotated clusters. The species essentially shared ribosomal DNA sequences, whereas the other classes of repetitive DNA were highly variable among species. The pool of full-length LTR-REs was retrieved from all the species and their age of insertion was established, showing several lineage-specific proliferation peaks over the last 15-million years. Overall, a large variability of repeat abundance at superfamily, lineage, and sublineage levels was observed, indicating that repeats within individual genomes followed different evolutionary and temporal dynamics, and that different events of amplification or loss of these sequences may have occurred after species differentiation

Bioimpedance Vector References Need to Be Period‐ Specific for Assessing Body Composition and Cellular Health in Elite Soccer Players: A Brief Report

none9noPurpose: Bioimpedance data through bioimpedance vector analysis (BIVA) is used to evaluate cellular function and body fluid content. This study aimed to (i) identify whether BIVA patters differ according to the competitive period and (ii) provide specific references for assessing bioelectric properties at the start of the season in male elite soccer players. Methods: The study included 131 male soccer players (age: 25.1 ± 4.7 yr, height: 183.4 ± 6.1 cm, weight: 79.3 ± 6.6) registered in the first Italian soccer division (Serie A). Bioimpedance analysis was performed just before the start of the competitive season and BIVA was applied. In order to verify the need for period-specific references, bioelectrical values measured at the start of the season were compared to the reference values for the male elite soccer player population. Results: The results of the two-sample Hotelling T2tests showed that in the bivariate interpretation of the raw bioimpedance parameters (resistance (R) and reactance (Xc)) the bioelectric properties significantly (T2= 15.3, F = 7.6, p ≤ 0.001, Mahalanobis D = 0.45) differ between the two phases of the competition analyzed. In particular, the mean impedance vector is more displaced to the left into the R-Xc graph at the beginning of the season than in the first half of the championship. Conclusions: For an accurate evaluation of body composition and cellular health, the tolerance ellipses displayed by BIVA approach into the R-Xc graph must be period-specific. This study provides new specific tolerance ellipses (R/H: 246 ± 32.1, Xc/H: 34.3 ± 5.1, r: 0.7) for performing BIVA at the beginning of the competitive season in male elite soccer players.openBongiovanni T.; Mascherini G.; Genovesi F.; Pasta G.; Iaia F.M.; Trecroci A.; Ventimiglia M.; Alberti G.; Campa F.Bongiovanni T.; Mascherini G.; Genovesi F.; Pasta G.; Iaia F.M.; Trecroci A.; Ventimiglia M.; Alberti G.; Campa F

A Measurement System for Power Inductors in Non-Linear Operating Conditions

The exploitation of power inductors in switching converters outside the linear region requires detailed information on the magnetization curve that often is not included among those usually available on their datasheets. This paper proposes an automatic system in which the inductor is characterized in real operating conditions taking into account also the core temperature. It is based on a switching converter suitably controlled by a virtual instrument. The system was tested by retrieving the inductance vs current curves of two commercial inductors for core temperatures up to 105°C, showing the different behaviors of the magnetization curves. Results are coherent with data given by manufacturers and provide a complete characterization of the inductors

Functional gastrointestinal disorders and smartphone use in adolescents

Question: Are functional gastrointestinal disorders (FGIDs) common in Italy? If so, what are the associated risk factors? Finding: In this cross-sectional study of 1,594 adolescents, the prevalence of FGIDs was 30.9% and was mainly associated with smartphone addiction. Meaning: Smartphone use and dietary habits should be monitored in children with FGI

Functional gastrointestinal disorders, lifestyle habits, and smartphone addiction in adolescents

We performed a cross-sectional study. In spring 2019, 1,594 students (mean age 12.87 years) completed a questionnaire on gastrointestinal symptoms, smartphone use, Quality of Life (QoL), dietary habits, and physical activity. Based on the Rome IV criteria, 30.9% of participants met the symptom-based criteria for FGIDs and 8.9% experienced ≥2 disorders simultaneously. Well-being was less frequently reported by children with FGIDs than others (29.0% vs. 48.2%; p < 0.001). Participants addicted to smartphones reported low than others well-being (18.0% vs. 25.8%; p < 0.001), they also showed higher prevalence of FGIDs [Odds Ratio (OR), 1.98; 95% Confidence Interval (CI), 1.47-2.68; p < 0.001]. Among dietary habits, skipping breakfast (OR, 1.50; 95% CI, 1.09-2.05; p = 0.01) and low fruit consumption (OR, 1.66; 95% CI, 1.172.36; p = 0.005) were more frequent in participants with FGIDs. FGIDs are common in pediatric populations. FGIDs have an impact on QoL. Some dietary habits and physical activity are associated with these disorders. Smartphone addiction was found to be associated with FGIDs

Use of molecular markers and flow cytometry to preserve ancient Annurca apple germplasm

The old Annurca apple cultivar (Malus domestica), particularly appreciated for its peculiar flavor and crispy flesh, was studied in order to preserve its ancient germplasm. Twelve clones of Annurca were analyzed using random amplified polymorphic DNA (RAPD) and simple-sequence repeat (SSR) markers. Two out of 30 RAPD primers and nine out of ten SSR primers were able to discriminate all the clones analyzed. Data were confirmed by measuring DNA content using flow cytometry. The results provide a good procedure to improve germplasm field management, in order to removing redundant material in the Annurca collection. This represents an efficient way to create a data bank in order to preserve the genetic variability of the Annurca cultivar

Assessment of MOSFET switching losses in an LLC converter by a calorimetric method

The present work aims to implement a calorimetric method to measure the power dissipated during MOSFET switching in a high efficiency LLC resonant converter. The power dissipated from switching can significantly impact the total power dissipated by the device and consequent efficiency, so correct quantification is fundamental for optimizing the devices and increasing the efficiency of the converters. In LLC converters, this type of dissipated power cannot be measured with standard methods such as measurement with oscilloscopes as some of the energy that is recovered and not dissipated. The calorimetric method requires reasonably accurate measurement of thermal resistance and the temperature of the die. To facilitate accurate temperature measurement, we used a device in an ACEPACK™ SMIT package module, which incorporates a complete half-bridge and an NTC thermistor for reading the temperature

Impact of transposable elements on the evolution of complex living systems and their epigenetic control

Transposable elements (TEs) contribute to genomic innovations, as well as genome instability, across a wide variety of species. Popular designations such as ‘selfish DNA’ and ‘junk DNA,’ common in the 1980s, may be either inaccurate or misleading, while a more enlightened view of the TE-host relationship covers a range from parasitism to mutualism. Both plant and animal hosts have evolved epigenetic mechanisms to reduce the impact of TEs, both by directly silencing them and by reducing their ability to transpose in the genome. However, TEs have also been co-opted by both plant and animal genomes to perform a variety of physiological functions, ranging from TE-derived proteins acting directly in normal biological functions to innovations in transcription factor activity and also influencing gene expression. Their presence, in fact, can affect a range of features at genome, phenotype, and population levels. The impact TEs have had on evolution is multifaceted, and many aspects still remain unexplored. In this review, the epigenetic control of TEs is contextualized according to the evolution of complex living systems