478 research outputs found

    Characterization of CMOS Spiral Inductors

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    In this work "full-wave" simulations of integrated inductors are presented and compared with measurements of fabricated CMOS chips. The good agreement between measurements and simulations demonstrates the accuracy of the tool, which is, hence, a cheaper alternative to experimental characterization. Furthermore, the proposed approach may give precious hints for performance improvements, by making internal device fields and currents available for the VLSI designer and providing compact, most effective, equivalent models

    Genetic variability in Bracco Italiano dog breed assessed by pedigree data

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    The Bracco Italiano is one of the oldest pointing dog breed, used for hunting ever since the Renaissance time. The complete electronic record of the breed was downloaded from the ENCI database [whole population (WP) = 24,613 animals registered since 1970 to 2011] with the aim to estimate genetic variability in Bracco Italiano dog breed using pedigree records. Up to 97% of the individuals had registered parents and 86% registered grand-fathers. Average generation interval was 4.68±0.545 for stallions and 4.08±0.321 year for dams. Reference population (RP) was defined as the population of interest that include living reproductive animals approaching the last three generations and include 9006 dogs of which 34% were inbreds. The number of ancestors was 564 in WP and 188 in RP, while the effective number of ancestors was 46 and 34 respectively. To explain 50% of the genetic variability, a total of 18 and 9 ancestors enough, respectively in the WP and RP. The average inbreeding coefficient in the RP resulted 6.7% while the average increase in inbreeding was estimated to be 1.29% (Ne=38.86). Nevertheless a regular monitoring of genetic variability of the population is important and must be adopted, in order to avoid the danger of an excessive increase of inbreeding in the future, which would result in significant inbreeding depression and in significant loss of genetic variation

    Detection and analysis of heartbeats in seismocardiogram signals

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    This paper presents an unsupervised methodology to analyze SeismoCardioGram (SCG) signals. Starting from raw accelerometric data, heartbeat complexes are extracted and annotated, using a two-step procedure. An unsupervised calibration procedure is added to better adapt to different user patterns. Results show that the performance scores achieved by the proposed methodology improve over related literature: on average, 98.5% sensitivity and 98.6% precision are achieved in beat detection, whereas RMS (Root Mean Square) error in heartbeat interval estimation is as low as 4.6 ms. This allows SCG heartbeat complexes to be reliably extracted. Then, the morphological information of such waveforms is further processed by means of a modular Convolutional Variational AutoEncoder network, aiming at extracting compressed, meaningful representation. After unsupervised training, the VAE network is able to recognize different signal morphologies, associating each user to its specific patterns with high accuracy, as indicated by specific performance metrics (including adjusted random and mutual information score, completeness, and homogeneity). Finally, a Linear Model is used to interpret the results of clustering in the learned latent space, highlighting the impact of different VAE architectural parameters (i.e., number of stacked convolutional units and dimension of latent space)

    A unified methodology for heartbeats detection in seismocardiogram and ballistocardiogram signals

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    This work presents a methodology to analyze and segment both seismocardiogram (SCG) and ballistocardiogram (BCG) signals in a unified fashion. An unsupervised approach is followed to extract a template of SCG/BCG heartbeats, which is then used to fine-tune temporal waveform annotation. Rigorous performance assessment is conducted in terms of sensitivity, precision, Root Mean Square Error (RMSE) and Mean Absolute Error (MAE) of annotation. The methodology is tested on four independent datasets, covering different measurement setups and time resolutions. A wide application range is therefore explored, which better characterizes the robustness and generality of the method with respect to a single dataset. Overall, sensitivity and precision scores are uniform across all datasets (p > 0.05 from the Kruskal–Wallis test): the average sensitivity among datasets is 98.7%, with 98.2% precision. On the other hand, a slight yet significant difference in RMSE and MAE scores was found (p < 0.01) in favor of datasets with higher sampling frequency. The best RMSE scores for SCG and BCG are 4.5 and 4.8 ms, respectively; similarly, the best MAE scores are 3.3 and 3.6 ms. The results were compared to relevant recent literature and are found to improve both detection performance and temporal annotation errors

    Morphological traits and inbreeding depression in Bracco Italiano dog breed.

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    This paper reports the first results of a survey on morphological traits in Bracco Italiano dog breed, and analyzes the effects of various levels of inbreeding on these measures. Traits were taken from 155 adult (mean age 4.18±2.60 years) dogs (79 males and 76 females) belonging to 57 different farms. For each animal, the following biometrical measurements were considered: height at withers (WH), height of chest (ChH), body length (BL), length at rump (RL), height at rump (RH), iliac width of rump (RIlW), ischiatic width of rump (RIsW), circumference of chest (ChC), circumference of cannon (CaC), length of ear (EL), and length of head (HL). The ratio of rump length/withers height (RL/WH), cannon circumference/chest circumference (CaC/ChC) and head length/withers height (HL/WH) were also calculated. ANOVA was used to test the differences between males and females and among farms in terms of morphological measurements and ratios. Significant differences between males and females were observed for many morphological traits. The measures coincided with what reported in the current breed standard, apart from the length of the rump, which was around ¼ of the withers height rather than the 1/3 required in the standard. No significant effect of inbreeding on conformation traits was observed

    Investigation on the genetic variability of the american pit bull terrier dogs belonging to an italian breeder using microsatellite markers and genealogical data

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    The genetic variability of 18 American Pit Bull Terriers bred in Italy was studied using 21 STR markers from the panels recommended for the 2006, 2008 and 2010 ISAG canine comparison test and the genealogical information. As expected, all statistical analysis showed a reduced genetic variability. It is there-fore recommended greater attention in the programming of mating with an increase of gene flow among farmers, which would reduce the average inbreeding in the population and increase genetic variability.Генетическая изменчивость 18 американских питбультерьеров, выведенных в Италии, была изучена с использованием 21 STR маркеров из панелей, рекомендованных Международной ассоциацией генетики животных (ISAG canine) (2006, 2008, 2010). Как и ожидалось, все статистические анализы подтвердили невысокую генетическую изменчивость. Поэтому желательно уделять больше внимания пла-нированию скрещиваний с увеличением потока генов, чтобы уменьшить средний инбридинг в популяции и увеличить генетическую изменчивость.Генетична мінливість 18 американських пітбультер’єрів, виведених в Італії, була вивчена з використанням 21 STR маркерів з панелей, рекомендованих Міжнародною асоціацією генетики тварин (ISAG canine) (2006,2008 і 2010). Як і очікувалося, всі статистичні аналізи підтвердили невисоку генетичну мінливість. Тому бажано приділяти більше уваги плануванню схрещувань із збільшенням потоку генів, щоб зменшити середній інбридинг в популяції і збільшити генетичну мінливість

    Insights into genetic diversity, runs of homozygosity and heterozygosity-rich regions in maremmana semi-feral cattle using pedigree and genomic data

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    Semi-feral local livestock populations, like Maremmana cattle, are the object of renewed interest for the conservation of biological diversity and the preservation and exploitation of unique and potentially relevant genetic material. The aim of this study was to estimate genetic diversity parameters in semi-feral Maremmana cattle using both pedigree-and genomic-based approaches (FIS and FROH), and to detect regions of homozygosity (ROH) and heterozygosity (ROHet) in the genome. The average heterozygosity estimates were in the range reported for other cattle breeds (HE = 0.261, HO = 0.274). Pedigree-based average inbreeding (F) was estimated at 4.9%. The correlation was low between F and genomic-based approaches (r = 0.03 with FIS, r = 0.21 with FROH), while it was higher between FIS and FROH (r = 0.78). The low correlation between F and FROH coefficients may be the result of the limited pedigree depth available for the animals involved in this study. The ROH islands identified in Maremmana cattle included candidate genes associated with climate adaptation, carcass traits or the regulation of body weight, fat and energy metabolism. The ROHet islands contained candidate genes associated with nematode resistance and reproduction traits in livestock. The results of this study confirm that genome-based measures like FROH may be useful estimators of individual autozygosity, and may provide insights on pedigree-based inbreeding estimates in cases when animals’ pedigree data are unavailable, thus providing a more detailed picture of the genetic diversity

    CFD analysis of the fuel-air mixture formation process in passive prechambers for use in a high-pressure direct injection (HPDI) Two-stroke engine

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    The research on two-stroke engines has been focused lately on the development of direct injection systems for reducing the emissions of hydrocarbons by minimizing the fuel shortcircuiting. Low temperature combustion (LTC) may be the next step to further improve emissions and fuel consumption; however, LTC requires unconventional ignition systems. Jet ignition, i.e., the use of prechambers to accelerate the combustion process, turned out to be an effective way to perform LTC. The present work aims at proving the feasibility of adopting passive prechambers in a high-pressure, direct injection, two-stroke engine through non-reactive computational fluid dynamics analyses. The goal of the analysis is the evaluation of the prechamber performance in terms of both scavenging efficiency of burnt gases and fuel/air mixture formation inside the prechamber volume itself, in order to guarantee the mixture ignitability. Two prechamber geometries, featuring different aspect ratios and orifice numbers, were investigated. The analyses were replicated for two different locations of the injection and for three operating conditions of the engine in terms of revolution speed and load. Upon examination of the results, the effectiveness of both prechambers was found to be strongly dependent on the injection setup

    Molecular Coancestry and Classical Genetic Distances Depict Different Patterns of Relationship Among Sheep Breeds from Southern Italy

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    Several molecular-based parameters, such as similarity indexes, can be adopted to optimize the management of genetic diversity in conservation programmes. From simulated data, Oliehoek et al. (2006) showed that molecular coancestry (Toro et al., 2002) is, among the possible relatedness estimators, the one that performs better in structured populations, such as populations in need of conservation usually are. Several studies have, therefore, proposed the use of molecular coancestry coefficients as a measure of genetic variability and as a useful tool for conservation of endangered breeds (Ciampolini et al., 2007; Glowatzki-Mullis et al., 2009). Here we report the results obtained evaluating within- and between-breed molecular coancestry (Toro et al., 2002), together with other classical genetic parameters, for two insular sheep breeds (Sarda from Sardinia and Comisana from Sicily), recently spread almost all over Italy, and for five local rare sheep breeds from Southern Italy
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