97 research outputs found
H 2 production based on RDG and assisted by a weak grid: System topology, operation and control
The Renewable Distributed Generation (RDG), such as production of electricity in the vicinity of the load, it is particularly beneficial when the distribution network is "weak" facing specific demands, as in hydrogen production systems connected to rural electrification networks. In these areas, the wind resource may be suitable for this type of generation. This work proposes the topology and the operation and control strategy for a hydrogen production station, "assisted" by a weak AC grid and "powered" by a variable speed wind turbine based on a three-phase double stator induction machine. The wind energy conversion is optimized through adequate control of the generator. The electrolyzer current is regulated for the maximum utilization of the generated power. The high-speed power fluctuations by turbulence are compensated through a controlled energy storage system based on a flywheel. In addition, the system configuration, its operation mode and control, and simulation results are presented.Fil: Camocardi, Pablo Andrés. Universidad Nacional de La Plata. Facultad de Ingeniería. Departamento de Electrotecnia. Laboratorio de Electrónica Industrial, Control e Instrumentación; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Toccaceli, Graciela Mabel. Universidad Nacional de La Plata. Facultad de Ingeniería. Departamento de Electrotecnia. Laboratorio de Electrónica Industrial, Control e Instrumentación; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Battaiotto, P. E.. Universidad Nacional de La Plata. Facultad de Ingeniería. Departamento de Electrotecnia. Laboratorio de Electrónica Industrial, Control e Instrumentación; ArgentinaFil: Cendoya, Marcelo Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ingeniería. Departamento de Electrotecnia. Laboratorio de Electrónica Industrial, Control e Instrumentación; Argentin
Natural leukocyte interferon alpha (Alfaferone) combined with ribavirin in the treatment of patients with HCV-related cirrhosis: our experience
Fenomeno Caulerpa 2010-2013. Rapporto sull'evoluzione delle specie aliene nel Canale di Sicilia
Gli studi effettuati da ARPA-Sicilia, ISPRA e CNR-IAMC hanno perseguito l’obiettivo principale
di monitorare e valutare l’impatto della diffusione delle alghe indagate, attraverso
l’analisi dell’evoluzione spazio-temporale del fenomeno e la caratterizzazione eco-tossicologica
delle aree di pesca maggiormente interessate dalla presenza delle caulerpe.
In particolare
Le ricerche di ARPA-Sicilia sono state mirate a:
- Definire le aree di studio principalmente interessate dal fenomeno di diffusione delle
due alghe aliene;
- Caratterizzare da un punto di vista ambientale le aree oggetto d’indagine;
- Valutare le pressioni antropiche che insistono lungo le coste delle aree indagate;
- Stimare l’influenza che le pressioni antropiche possono esercitare sulla diffusione della
Caulerpa;
- Indagare l’andamento spazio-temporale della distribuzione di Caulerpa in specifiche
aree di indagine.
Gli studi condotti da ISPRA hanno puntato a:
- Valutare possibili interferenze dell’alga con le attività di pesca, l’intasamento delle reti
e la riduzione della pescabilità dell’attrezzo;
- Rilevare l’eventuale diversità tra aree con insediamento e prive di insediamento;
- Avviare l’introduzione di buone pratiche per evitare che la pesca possa rappresentare
un ulteriore vettore di invasioni secondarie attraverso disseminazione dei frammenti e
propaguli dell’alga;
- Definire comportamenti alieutici nel tempo utili alla mitigazione del potenziale impatto
della pesca sulle risorse nelle aree colpite;
- Istituire in tutta l’area di studio e, in particolare, nell’arcipelago delle Pelagie, un “Osservatorio
delle Specie Aliene” per svolgere attività di monitoraggio sulla diffusione delle
specie aliene, al fine di formulare proposte gestionali mirate alla salvaguardia degli ecosistemi
e delle attività economiche di pesca.
Le indagini realizzate dal CNR-IAMC hanno avuto come obiettivi principali:
- Confrontare le caratteristiche dei popolamenti bentonici associati a praterie di Posidonia
oceanica della Sicilia meridionale interessate dall’invasione di Caulerpa taxifolia var.
distichophylla con quelle di popolamenti associati a posidonieti di località limitrofe non
colpite dal fenomeno;
- Confrontare la struttura trofica della comunità bentonica associata a matte di Posidonia
oceanica in località invase e non invase da alghe aliene del genere Caulerpa della Sicilia
meridionale;
- Valutare gli effetti dell’invasione di Caulerpa racemosa var. cylindracea sulla struttura
e sulla funzione di popolamenti macrobentonici sessili di fondo duro dell’infralitorale
Artificial intelligence in biological activity prediction
Artificial intelligence has become an indispensable resource in chemoinformatics. Numerous machine learning algorithms for activity prediction recently emerged, becoming an indispensable approach to mine chemical information from large compound datasets. These approaches enable the automation of compound discovery to find biologically active molecules with important properties. Here, we present a review of some of the main machine learning studies in biological activity prediction of compounds, in particular for sweetness prediction. We discuss some of the most used compound featurization techniques and the major databases of chemical compounds relevant to these tasks.This study was supported by the European Commission through project SHIKIFACTORY100 - Modular cell factories for the production of 100 compounds from the shikimate pathway (Reference 814408), and by the Portuguese FCT under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020.info:eu-repo/semantics/publishedVersio
H3K4me1 marks DNA regions hypomethylated during aging in human stem and differentiated cells
In differentiated cells, aging is associated with hypermethylation of DNA regions enriched in repressive histone post-translational modifications. However, the chromatin marks associated with changes in DNA methylation in adult stem cells during lifetime are still largely unknown. Here, DNA methylation profiling of mesenchymal stem cells (MSCs) obtained from individuals aged 2 to 92 yr identified 18,735 hypermethylated and 45,407 hypomethylated CpG sites associated with aging. As in differentiated cells, hypermethylated sequences were enriched in chromatin repressive marks. Most importantly, hypomethylated CpG sites were strongly enriched in the active chromatin mark H3K4me1 in stem and differentiated cells, suggesting this is a cell type-independent chromatin signature of DNA hypomethylation during aging. Analysis of scedasticity showed that interindividual variability of DNA methylation increased during aging in MSCs and differentiated cells, providing a new avenue for the identification of DNA methylation changes over time. DNA methylation profiling of genetically identical individuals showed that both the tendency of DNA methylation changes and scedasticity depended on nongenetic as well as genetic factors. Our results indicate that the dynamics of DNA methylation during aging depend on a complex mixture of factors that include the DNA sequence, cell type, and chromatin context involved and that, depending on the locus, the changes can be modulated by genetic and/or external factors
Educational attainment of same-sex and opposite-sex dizygotic twins : An individual-level pooled study of 19 twin cohorts
Comparing twins from same- and opposite-sex pairs can provide information on potential sex differences in a variety of outcomes, including socioeconomic-related outcomes such as educational attainment. It has been suggested that this design can be applied to examine the putative role of intrauterine exposure to testosterone for educational attainment, but the evidence is still disputed. Thus, we established an international database of twin data from 11 countries with 88,290 individual dizygotic twins born over 100 years and tested for differences between twins from same- and opposite-sex dizygotic pairs in educational attainment. Effect sizes with 95% confidence intervals (CI) were estimated by linear regression models after adjusting for birth year and twin study cohort. In contrast to the hypothesis, no difference was found in women (β = −0.05 educational years, 95% CI −0.11, 0.02). However, men with a same-sex co-twin were slightly more educated than men having an opposite-sex co-twin (β = 0.14 educational years, 95% CI 0.07, 0.21). No consistent differences in effect sizes were found between individual twin study cohorts representing Europe, the USA, and Australia or over the cohorts born during the 20th century, during which period the sex differences in education reversed favoring women in the latest birth cohorts. Further, no interaction was found with maternal or paternal education. Our results contradict the hypothesis that there would be differences in the intrauterine testosterone levels between same-sex and opposite-sex female twins affecting education. Our findings in men may point to social dynamics within same-sex twin pairs that may benefit men in their educational careers.Peer reviewe
Genetic and environmental variation in educational attainment: an individual-based analysis of 28 twin cohorts
We investigated the heritability of educational attainment and how it differed between birth cohorts and cultural-geographic regions. A classical twin design was applied to pooled data from 28 cohorts representing 16 countries and including 193,518 twins with information on educational attainment at 25 years of age or older. Genetic factors explained the major part of individual differences in educational attainment (heritability: a2 = 0.43; 0.41-0.44), but also environmental variation shared by co-twins was substantial (c2 = 0.31; 0.30-0.33). The proportions of educational variation explained by genetic and shared environmental factors did not differ between Europe, North America and Australia, and East Asia. When restricted to twins 30 years or older to confirm finalized education, the heritability was higher in the older cohorts born in 1900-1949 (a2 = 0.44; 0.41-0.46) than in the later cohorts born in 1950-1989 (a2 = 0.38; 0.36-0.40), with a corresponding lower influence of common environmental factors (c2 = 0.31; 0.29-0.33 and c2 = 0.34; 0.32-0.36, respectively). In conclusion, both genetic and environmental factors shared by co-twins have an important influence on individual differences in educational attainment. The effect of genetic factors on educational attainment has decreased from the cohorts born before to those born after the 1950s
Genetic and environmental variation in educational attainment : an individual-based analysis of 28 twin cohorts
We investigated the heritability of educational attainment and how it differed between birth cohorts and cultural-geographic regions. A classical twin design was applied to pooled data from 28 cohorts representing 16 countries and including 193,518 twins with information on educational attainment at 25 years of age or older. Genetic factors explained the major part of individual differences in educational attainment (heritability: a(2)=0.43; 0.41-0.44), but also environmental variation shared by co-twins was substantial (c(2)=0.31; 0.30-0.33). The proportions of educational variation explained by genetic and shared environmental factors did not differ between Europe, North America and Australia, and East Asia. When restricted to twins 30 years or older to confirm finalized education, the heritability was higher in the older cohorts born in 1900-1949 (a(2)=0.44; 0.41-0.46) than in the later cohorts born in 1950-1989 (a(2)=0.38; 0.36-0.40), with a corresponding lower influence of common environmental factors (c(2)=0.31; 0.29-0.33 and c(2)=0.34; 0.32-0.36, respectively). In conclusion, both genetic and environmental factors shared by co-twins have an important influence on individual differences in educational attainment. The effect of genetic factors on educational attainment has decreased from the cohorts born before to those born after the 1950s.Peer reviewe
Genetic and environmental influences on human height from infancy through adulthood at different levels of parental education
Genetic factors explain a major proportion of human height variation, but differences in mean stature have also been found between socio-economic categories suggesting a possible effect of environment. By utilizing a classical twin design which allows decomposing the variation of height into genetic and environmental components, we tested the hypothesis that environmental variation in height is greater in offspring of lower educated parents. Twin data from 29 cohorts including 65,978 complete twin pairs with information on height at ages 1 to 69 years and on parental education were pooled allowing the analyses at different ages and in three geographic-cultural regions (Europe, North America and Australia, and East Asia). Parental education mostly showed a positive association with offspring height, with significant associations in mid-childhood and from adolescence onwards. In variance decomposition modeling, the genetic and environmental variance components of height did not show a consistent relation to parental education. A random-effects meta-regression analysis of the aggregate-level data showed a trend towards greater shared environmental variation of height in low parental education families. In conclusion, in our very large dataset from twin cohorts around the globe, these results provide only weak evidence for the study hypothesis.Peer reviewe
- …