577 research outputs found

    A note on the finite basis and finite rank properties for pseudovarieties of semigroups

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    The finite basis property is often connected with the finite rank property, which it entails. Many examples have been produced of finite rank varieties which are not finitely based. In this note, we establish a result on nilpotent pseudovarieties which yields many similar examples in the realm of pseudovarieties of semigroups. (c) 2017, Springer Science+Business Media, LLC, part of Springer Nature

    One-dimensional Dirac oscillator in a thermal bath

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    We analyze the one-dimensional Dirac oscillator in a thermal bath. We found that the heat capacity is two times greater than the heat capacity of the one-dimensional harmonic oscillator for higher temperatures.Comment: 4 pages, 3 figures, to appear in Physics Letters

    Intramuscular fat prediction using color and image analysis of bĂ­saro pork breed

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    This work presents an analytical methodology to predict meat juiciness (discriminant semi-quantitative analysis using groups of intervals of intramuscular fat) and intramuscular fat (regression analysis) in Longissimus thoracis et lumborum (LTL) muscle of Bísaro pigs using as independent variables the animal carcass weight and parameters from color and image analysis. These are non-invasive and non-destructive techniques which allow development of rapid, easy and inexpensive methodologies to evaluate pork meat quality in a slaughterhouse. The proposed predictive supervised multivariate models were non-linear. Discriminant mixture analysis to evaluate meat juiciness by classified samples into three groups—0.6 to 1.1%; 1.25 to 1.5%; and, greater than 1.5%. The obtained model allowed 100% of correct classifications (92% in cross-validation with seven-folds with five repetitions). Polynomial support vector machine regression to determine the intramuscular fat presented R2 and RMSE values of 0.88 and 0.12, respectively in cross-validation with seven-folds with five repetitions. This quantitative model (model’s polynomial kernel optimized to degree of three with a scale factor of 0.1 and a cost value of one) presented R2 and RSE values of 0.999 and 0.04, respectively. The overall predictive results demonstrated the relevance of photographic image and color measurements of the muscle to evaluate the intramuscular fat, rarther than the usual time-consuming and expensive chemical analysis.Work included in the Portuguese PRODER research Project BISOPORC—Pork extensive production of Bísara breed, in two alternative systems: fattening on concentrate vs. chesnut. The CIMO authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020) and are members of the Healthy Meat network by (CYTED-119RT0568). The CECAV authors are thankful to the project UIDB/CVT/00772/2020 funded by the Foundation for Science and Technology (FCT, Portugal). The authors are grateful to Laboratory of Carcass and Meat Quality of Agriculture School of Polytechnic Institute of Bragança “Cantinho do Alfredo”.UIDB/CVT/00772/2020info:eu-repo/semantics/publishedVersio

    ICAM-1 expression on immune cells in chronic villitis

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    AbstractIntroductionICAM-1 expression on the villous syncytiotrophoblast (ST) is believed to participate in migration of maternal cells into the inflamed villi regardless of villitis etiology. However, its expression on immune cells in chronic villitis (CV) has yet to be analyzed. ICAM-1 induces cell–cell adhesion allowing intercellular communication, T cell-mediated defense mechanism, and inflammatory response.Material and methods21 cases of CV (all without an identifiable etiologic agent) and 3 control placentas were analyzed using ICAM-1, and for immune cells CD45, CD3 and CD68. These cells were subdivided according to their location in inflamed villi: a) within the inflamed villi and b) outside forming perivillous aggregates.ResultsLarge amounts of CD45, CD3 and CD68 were found within the inflamed villi and forming perivillous aggregates attached to areas of trophoblastic loss. Inflamed villi usually showed ICAM-1+ ST. The majority of immune cells surrounding areas of trophoblastic rupture presented marked expression of ICAM-1. In contrast, a small number of immune cells within the inflamed villi exhibited ICAM-1 expression. Only some (<5%) inflamed villi without trophoblastic rupture and with ICAM-1+ ST presented adherence of immune cells.DiscussionIn inflamed villi of chronic villitis, the level of ICAM-1 expression on immune cells depends on their location: high in number of cells in the perivillous region and low within the villi. The strongest expression of ICAM-1 on immune cells attached to areas of trophoblastic rupture suggests that the loss of trophoblast can lead to an amplification of the inflammatory response

    Minimal Position-Velocity Uncertainty Wave Packets in Relativistic and Non-relativistic Quantum Mechanics

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    We consider wave packets of free particles with a general energy-momentum dispersion relation E(p)E(p). The spreading of the wave packet is determined by the velocity v = \p_p E. The position-velocity uncertainty relation ΔxΔv≄1/2∣∣\Delta x \Delta v \geq {1/2} || is saturated by minimal uncertainty wave packets Ί(p)=Aexp⁥(−αE(p)+ÎČp)\Phi(p) = A \exp(- \alpha E(p) + \beta p). In addition to the standard minimal Gaussian wave packets corresponding to the non-relativistic dispersion relation E(p)=p2/2mE(p) = p^2/2m, analytic calculations are presented for the spreading of wave packets with minimal position-velocity uncertainty product for the lattice dispersion relation E(p)=−cos⁥(pa)/ma2E(p) = - \cos(p a)/m a^2 as well as for the relativistic dispersion relation E(p)=p2+m2E(p) = \sqrt{p^2 + m^2}. The boost properties of moving relativistic wave packets as well as the propagation of wave packets in an expanding Universe are also discussed

    InfluĂȘncia da qualidade dos materiais de reprodução na reflorestação com sobreiro

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    O sobreiro ocupa em Portugal cerca de 721000 ha o que corresponde a 21,5 % da ĂĄrea fl orestal nacional e 33% da ĂĄrea mundial (APCOR, 2005). A sua distribuição no territĂłrio nacional traduz nĂŁo sĂł a sua adaptação a determinadas condiçÔes edafo-climaticas, mas tem sido condicionada por vĂĄrias circunstancias, como o arroteamento, o fogo, o abuso do pastoreio, a exploração agrĂ­cola intensiva e as plantaçÔes fl orestais que contrariaram ou favoreceram a sua existĂȘncia nesses locais (Natividade, 1950). A distribuição desta espĂ©cie Ă© particularmente signifi cativa em zonas onde tĂȘm ocorrido acontecimentos climĂĄticos graves e onde os nĂ­veis de desertifi cação humana sĂŁo crĂ­ticos. A fi leira da cortiça salienta-se por Portugal ocupar o primeiro lugar entre os paĂ­ses produtores, transformadores e exportadores de cortiça, correspondendo-lhe mais de metade da produção mundial desta matĂ©ria-prima. O nosso PaĂ­s Ă© a origem de aproximadamente 60% das transacçÔes de cortiça a nĂ­vel mundial, valor que sobe para 80% quando nos referimos a transacçÔes de produtos transformados. A nĂ­vel nacional, o valor das exportaçÔes de cortiça representam aproximadamente 0,7% do PIB, 2,24% das exportaçÔes e correspondem a mais de 33% do conjunto das exportaçÔes de produtos fl orestais (APCOR, 2005). Para alĂ©m da importĂąncia econĂłmica do sector corticeiro a nĂ­vel nacional, o aumento da consciĂȘncia e do interesse da sociedade nas questĂ”es ambientais, faz com que o montado de sobro seja reconhecido cada vez mais como um espaço fl orestal, de elevada biodiversidade, paisagĂ­sticamente Ășnico, que potencia micro-economias locais baseadas numa agricultura e pastorĂ­cia extensivas, interessante para outras actividades como o turismo rural e a caça. O sobreiro tem sido a espĂ©cie fl orestal que mais tem benefi ciado dos meios fi nanceiros disponibilizados aos proprietĂĄrios fl orestais para a refl orestação no Ăąmbito da aplicação das medidas de reforma da PolĂ­tica AgrĂ­cola Comum da UE, na arborização das terras agrĂ­colas. Contudo, tĂȘm-se registado com frequĂȘncia elevadas taxas de insucesso na arborização sendo a qualidade dos materiais florestais de reprodução (MFR) apontada como uma das causas. Neste trabalho abordaremos a a qualidade dos materiais de reprodução, considerando-a do ponto de vista genĂ©tico e fisiolĂłgicoN/

    Physiological and biochemical responses to low non-freezing temperature of two Eucalyptus globulus clones differing in drought resistance

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    Abstract – We have compared the metabolic responses of leaves and roots of two Eucalyptus globulus L. clones CN5 and ST51 that differ in their sensitivity to water deficits (ST51 is more drought sensitive), with regard to the effect of chilling (10/5 ◩C, day/night). We studied changes in growth, osmotic potential and osmotically active compounds, soluble proteins, leaf pigments, and membrane lipid composition. Our data showed that both clones have the ability to acclimatize to chilling temperatures. As a result of 10 days of acclimation, an increase of soluble sugars in leaves of treated plants of both clones was observed that disappeared later on. Differences between clones were observed in the photosynthetic pigments and soluble protein content which were more stable in CN5 under chilling. It also was apparent that CN5 presented a less negative predawn water potential (ψpd) and a higher leaf turgor than ST51 throughout the chilling treatment. In the case of the CN5, increased total lipids (TFA) and concomitant increase of linolenic acid (C18:3) in leaves after acclimatization may be related to a better clone performance under chilling temperatures. Moreover, a higher constitutive investment in roots in the case of CN5 as compared to ST51 may benefit new root regeneration under low temperatures favoring growth after cold Mediterranean winter

    Structure of Fat Jets at the Tevatron and Beyond

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    Boosted resonances is a highly probable and enthusiastic scenario in any process probing the electroweak scale. Such objects when decaying into jets can easily blend with the cornucopia of jets from hard relative light QCD states. We review jet observables and algorithms that can contribute to the identification of highly boosted heavy jets and the possible searches that can make use of such substructure information. We also review previous studies by CDF on boosted jets and its measurements on specific jet shapes.Comment: invited review for a special "Top and flavour physics in the LHC era" issue of The European Physical Journal C, we invite comments regarding contents of the review; v2 added references and institutional preprint number

    Acclimation to short-term low temperatures in two Eucalyptus globulus clones with contrasting drought resistance

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    We tested the hypothesis that Eucalyptus globulus Labill. genotypes that are more resistant to dry environments might also exhibit higher cold tolerances than drought-sensitive plants. The effect of low temperatures was evaluated in acclimated and unacclimated ramets of a drought-resistant clone (CN5) and a drought-sensitive clone (ST51) of E. globulus. We studied the plants’ response via leaf gas exchanges, leaf water and osmotic potentials, concentrations of soluble sugars, several antioxidant enzymes and leaf electrolyte leakage. Progressively lowering air temperatures (from 24/16 to 10/ 2 C, day/night) led to acclimation of both clones. Acclimated ramets exhibited higher photosynthetic rates, stomatal conductances and lower membrane relative injuries when compared to unacclimated ramets. Moreover, low temperatures led to significant increases of soluble sugars and antioxidant enzymes activity (glutathione reductase, ascorbate peroxidase and superoxide dismutases) of both clones in comparison to plants grown at control temperature (24/16 C). On the other hand, none of the clones, either acclimated or not, exhibited signs of photoinhibition under low temperatures and moderate light. The main differences in the responses to low temperatures between the two clones resulted mainly from differences in carbon metabolism, including a higher accumulation of soluble sugars in the drought-resistant clone CN5 as well as a higher capacity for osmotic regulation, as compared to the droughtsensitive clone ST51. Although membrane injury data suggested that both clones had the same inherent freezing tolerance before and after cold acclimation, the results also support the hypothesis that the droughtresistant clone had a greater cold tolerance at intermediate levels of acclimation than the drought-sensitive clone. A higher capacity to acclimate in a short period can allow a clone to maintain an undamaged leaf surface area along sudden frost events, increasing growt
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