950 research outputs found

    Symbolic Computation of Variational Symmetries in Optimal Control

    Get PDF
    We use a computer algebra system to compute, in an efficient way, optimal control variational symmetries up to a gauge term. The symmetries are then used to obtain families of Noether's first integrals, possibly in the presence of nonconservative external forces. As an application, we obtain eight independent first integrals for the sub-Riemannian nilpotent problem (2,3,5,8).Comment: Presented at the 4th Junior European Meeting on "Control and Optimization", Bialystok Technical University, Bialystok, Poland, 11-14 September 2005. Accepted (24-Feb-2006) to Control & Cybernetic

    Companies and Sustainable Development: The Adequacy of Environmental Impact Assessment for the Management of Environmental Risks

    Get PDF
    The choice of the environmental risk management instrument to be used within the scope of corporate governance in companies is of paramount importance to avoid or mitigate the triple environmental responsibility to which they are exposed. In this sense, the following research problem arises: The Environmental Impact Assessment (EIA), an instrument of the National Environment Policy and a model of environmental risk management adopted by some companies, proves to be efficient, effective and effective for the fulfillment of the duty to protect the environmental balance and, therefore, for sustainable development? The present study aims to elucidate this research problem. To this end, analyzes were carried out on risk and environmental damage, from a perspective of the socioenvironmental function of companies today; the need for a new posture by companies in view of the reflexes of environmental risks in business activity; and the question of the adequacy or inadequacy of the EIA as an instrument of the National Environment Policy and as a model for managing environmental risks and damages, in the pursuit of sustainable development. The method of approach used was the deductive one, and the research was carried out using the method of bibliographic procedure, through which research was carried out on books, scientific articles and legislation. The result points out the inefficiency and ineffectiveness of the EIA for the management of environmental risks and, thus, for the fulfillment of the duty to protect the environmental balance by companies

    Short communication: Genetic parameters for post-weaning visual scores and reproductive traits in Suffolk sheep

    Get PDF
              The aim of this study was to estimate the coefficients of heritability and genetic correlations among visual scores (conformation, CPW; precocity, PPW; musculature, MPW) and reproductive traits: age at first lambing (AFL) and scrotal circumference (SC) evaluated at 180 days of age in Suffolk lambs. In the statistical model only the additive genetic effect was considered as random effect. The heritability estimates by univariate analyses for CPW, PPW, MPW, AFL and SC were 0.08, 0.12, 0.09, 0.20 and 0.22, respectively. The genetic correlations among AFL and CPW, PPW, MPW were -0.26, 0.19, and 0.08, respectively. The genetic correlation among SC and CPW, PPW, MPW were, respectively, 0.54, 0.88 and 0.86, and between AFL and SC was 0.26. The direct selection for conformation, precocity and musculature at 180 days of age and age at first lambing will provide slow genetic progress due to low heritability estimates. It is possible to obtain genetic gain in sexual precocity through selection on scrotal circumference in Suffolk rams. The favorable genetic correlation among visual scores and SC and between CPW and AFL, indicated the possibility to gain in genetic progress for reproductive traits through indirect selection of the visual scores in Suffolk sheep

    Eosinophil recruitment into sites of delayed‐type hypersensitivity reactions in mice

    Full text link
    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142239/1/jlb0353.pd

    Photon-number-resolving segmented avalanche-photodiode detectors

    Full text link
    We investigate the feasibility and performance of photon-number-resolved photodetection employing avalanche photodiodes (APDs) with low dark counts. The main idea is to split n photons over m modes such that every mode has no more than one photon, which is detected alongside propagation by an APD. We characterize performance by evaluating the purities of positive-operator-valued measurements (POVMs), in terms of APD number and photon loss.Comment: 5 pages, 7 figures, submitted for publicatio

    The gill transcriptome of threatened European freshwater mussels

    Get PDF
    Genomic tools applied to non-model organisms are critical to design successful conservation strategies of particularly threatened groups. Freshwater mussels of the Unionida order are among the most vulnerable taxa and yet almost no genetic resources are available. Here, we present the gill transcriptomes of five European freshwater mussels with high conservation concern: Margaritifera margaritifera, Unio crassus, Unio pictorum, Unio mancus and Unio delphinus. The final assemblies, with N50 values ranging from 1069–1895 bp and total BUSCO scores above 90% (Eukaryote and Metazoan databases), were structurally and functionally annotated, and made available. The transcriptomes here produced represent a valuable resource for future studies on these species’ biology and ultimately guide their conservation.AGS was funded by the Portuguese Foundation for Science and Technology (FCT) under the grant SFRH/ BD/137935/2018, that also supported MLL (2020.03608.CEECIND) and EF (CEECIND/00627/2017). This research was developed under the project EdgeOmics - Freshwater Bivalves at the edge: Adaptation genomics under climate-change scenarios (PTDC/CTA-AMB/3065/2020) funded by FCT through national funds. Additional strategic funding was provided by FCT UIDB/04423/2020 and UIDP/04423/2020.info:eu-repo/semantics/publishedVersio

    Quantification of GHB and GHB-GLUC in an 1,4-butanediol intoxication: a case report

    Get PDF
    Gamma-hydroxybutyric acid (GHB) is an endogenous compound with known action at the neural level. Its psychoactive effects led to an illicit use context including recreational purposes, muscle building effects in bodybuilders and drug-facilitated crimes, specifically in sexual assaults. Besides the misuse of the main compound, there are precursors like Gammabutyrolactone (GBL) and 1,4-butanediol (1,4-BD), usually non controlled substances, becoming a much easier way to obtain the target-compound. The authors present the first reported intoxication case in Portugal with 1,4-Butanediol, including the quantification of GHB and GHB-GLUC in serum, by GC-MS/MS TQD. A suspicious liquid and a serum sample were sent by an hospital ER and analysed by GC-MS-single quadrupole and GC-MS/MS TQD, respectively. A methodology including protein precipitation and GC-MS/MS TQD analysis was used to detect and quantify GHB and GHB-GLUC in serum. Toxicological analysis revealed the presence of 1,4-Butanediol in the liquid and GHB [171 mg/L] and GHB-GLUC [13,7 mg/L] in serum. The victim reverted the coma with no neurological sequelae. This was the first detected case, in Portugal, with 1,4-Butanediol, suggesting that it is important to be aware that consumers have different options to obtain illicit compounds, such as GHB. On the other hand, GHB-GLUC was identified and quantified for the first time in a real case, due to intoxication. This case highlights the importance of analysing all samples for active compounds, precursors and metabolites that can lead to the main intoxication origin.publishe

    The crown pearl V2: an improved genome assembly of the European freshwater pearl mussel Margaritifera margaritifera (Linnaeus, 1758)

    Get PDF
    Contiguous assemblies are fundamental to deciphering the composition of extant genomes. In molluscs, this is considerably challenging owing to the large size of their genomes, heterozygosity, and widespread repetitive content. Consequently, long-read sequencing technologies are fundamental for high contiguity and quality. The first genome assembly of Margaritifera margaritifera (Linnaeus, 1758) (Mollusca: Bivalvia: Unionida), a culturally relevant, widespread, and highly threatened species of freshwater mussels, was recently generated. However, the resulting genome is highly fragmented since the assembly relied on short-read approaches. Here, an improved reference genome assembly was generated using a combination of PacBio CLR long reads and Illumina paired-end short reads. This genome assembly is 2.4 Gb long, organized into 1,700 scaffolds with a contig N50 length of 3.4 Mbp. The ab initio gene prediction resulted in 48,314 protein-coding genes. Our new assembly is a substantial improvement and an essential resource for studying this species’ unique biological and evolutionary features, helping promote its conservation.AGS was funded by the Portuguese Foundation for Science and Technology (FCT) under the grant SFRH/BD/137935/2018 and COVID/DB/152933/2022, which also supported MLL (2020.03608.CEECIND) and EF (CEECINST/00027/2021). This research was developed under the project EdgeOmics - Freshwater Bivalves at the Edge: Adaptation genomics under climate-change scenarios (PTDC/CTA-AMB/3065/2020) funded by FCT through national funds. Additional strategic funding was provided by FCT UIDB/04423/2020 and UIDP/04423/2020.info:eu-repo/semantics/publishedVersio

    Enhanced optical gain clamping for upstream packet based traffic on hybrid WDM/TDM-PON using fiber bragg grating

    Get PDF
    In this paper, we propose a method to mitigate the temporal power transients arising from Erbium doped fiber amplifiers (EDFAs) on packeted/bursty scenario. The technique, applicable on hybrid WDM/TDM-PON for extended reach, is based on a low power clamping provided by a distributed feedback (DFB) laser and a fiber Bragg grating (FBG). An mprovement in the data signal Q factor was achieved keeping the clamping control signal with a low power, accompanied by a maximum reduction in the gain excursion of 1.12 d

    Filtração em cerâmica microporosa aplicada à remoção de cor e turbidez de água para abastecimento público

    Get PDF
    Um filtro cerâmico com porosidade de 0,1μm, 60 cm de altura e 6 cm de diâmetro e 1 cm de espessura foi utilizado para estudar a remoção de cor e turbidez da água bruta. A unidade apresentava 0,113m² de superfície externa e estava montada no interior de uma coluna em acrílico com 100 cm de altura e 23 cm de diâmetro, com volume útil de 41,5 L. A água bruta, utilizada na pesquisa, foi proveniente de uma represa onde os valores de turbidez variaram de 2,3 a 2,8 NTU e cor aparente de 93 e 109 PtCo. Foram empregadas 3 diferentes taxas de aplicação, sendo de 1,82, 3,16 e 4,49m3/m2.dia, onde foram realizadas três carreiras de filtração para cada taxa. A duração de cada carreira de filtração estabilizou em 100, 42 e 26 minutos, respectivamente para cada taxa de aplicação. As amostras de água, utilizadas para verificar sua qualidade, foram coletadas, na entrada e saída do filtro a cada 5 cm de perda de carga até completar 20 cm. Os resultados obtidos demonstraram uma eficiência na remoção de turbidez entre 75 e 80%, resultando valores de entre 0,53 e 0,58 NTU para a última carreira de filtração para cada taxa de aplicação. Em contrapartida o sistema não se mostrou eficiente para remoção de cor aparente ficando entre 27 e 38%, mantendo valores elevados, ou seja, superiores a 62 PtCo, dessa forma o sistema não se mostrou eficiente para a remoção de cor
    corecore