956 resultados para Sun SPOT
Resumo:
The selectivity of four hook sizes (STELL brand(1), Quality 2335, numbers 12, 9, 6 and 4) used in a semi-pelagic longline fishery was studied in the Azores. Two species were caught in sufficient numbers for modelling of selectivity: the black spot sea bream (Pagellus bogaraveo) and the bluemouth rockfish (Helicolenus dactylopterus dactylopterus). A maximum likelihood method was used to fit a versatile model which can be used to describe a wide range of selectivity curves; from bell-shaped to asymptotic. Significant differences in size selectivity between hooks were found for both species. In the case of Pagellus bogaraveo, the smallest hook (number 12) had the lowest catch rates and all hooks were characterised by logistic-type selectivity curves, with sizes at 50% selectivity of: 27.9, 30.4, and 32.8 cm for hooks numbers 12, 9 and 6, respectively. The number 9 hook was the most efficient for Helicolenus d. dactylopterus, with selectivity curves varying from strongly skewed to the right for the number 12 hook to logistic-type for the numbers 6 and 4 hooks. Sizes at 50% selectivity for this species were 16.8, 18.7, 20.7, and 22.0 cm. respectively. (C) 1999 Elsevier Science B.V. All rights reserved.
Resumo:
Some research works state that speculation with agricultural commodities on the futures market has risen agricultural commodity spot prices. This research work analyzes the causal relationships between spot prices of corn, wheat, and soybean and agricultural commodity futures trading activities. These causal relationships between agricultural commodity spot prices and financial variables are tested for Granger-causality. Model results show that causal relationships have been found among changes in “volume traded” and “open positions” of futures contracts and changes in spot prices for corn. These results do not show that financial speculation might be a major driver of rising agricultural commodity prices.
Resumo:
The signature of 60Fe in deep-sea crusts indicates that one or more supernovae exploded in the solar neighbourhood about 2.2 million years ago1–4. Recent isotopic analysis is consistent with a core-collapse or electron-capture supernova that occurred 60 to 130 parsecs from the Sun5. Moreover, peculiarities in the cosmic ray spectrum point to a nearby supernova about two million years ago6. The Local Bubble of hot, diffuse plasma, in which the Solar System is embedded, originated from 14 to 20 supernovae within a moving group, whose surviving members are now in the Scorpius– Centaurus stellar association7,8. Here we report calculations of the most probable trajectories and masses of the supernova progenitors, and hence their explosion times and sites. The 60Fe signal arises from two supernovae at distances between 90 and 100 parsecs. The closest occurred 2.3 million years ago at present-day galactic coordinates l = 327°, b = 11°, and the second-closest exploded about 1.5 million years ago at l = 343°, b = 25°, with masses of 9.2 and 8.8 times the solar mass, respectively. The remaining supernovae, which formed the Local Bubble, contribute to a smaller extent because they happened at larger distances and longer ago (60Fe has a half- life of 2.6 million years9,10). There are uncertainties relating to the nucleosynthesis yields and the loss of 60Fe during transport, but they do not influence the relative distribution of 60Fe in the crust layers, and therefore our model reproduces the measured relative abundances very well.
Resumo:
Cultivares comerciais de macieiras são infectadas por 3 espécies principais de vírus: Apple chlorotic leaf spot virus (ACLSV), Apple stem grooving virus (ASGV) e Apple stem pitting virus (ASPV), geralmente em infecções complexas. O objetivo do estudo foi caracterizar a diversidade genética de genes da proteína capsidial (CP) de isolados de ACLSV.
Resumo:
2007
Resumo:
2016
Resumo:
A alface é uma hortaliça folhosa de grande importância econômica e social no Brasil, pois bastante cultivada por pequenos produtores e em hortas familiares. Isto ocorre principalmente pela facilidade que a cultura apresenta em se adaptar às mais diferentes condições. As doenças causadas por vírus são as principais responsáveis pelas perdas na produção na cultura, entre elas destacam-se as causadas por vírus do gênero Tospovirus. Durante visitas realizadas a áreas produtoras de hortaliças localizadas na região metropolitana de Belém-Pará, foi observada a alta incidência de plantas com sintomas de viroses. Assim, o trabalho teve como objetivo identificar o agente causal do vira cabeça da alface, por meio de RT-PCR e sequenciamento do ácido nucléico. Para isso, foi feita a extração de ácidos nucleicos total a partir de folhas de alface com sintoma de vira-cabeça e, posteriormente foi realizado o RT-PCR utilizando os primers universais para o gênero Tospovirus. O produto do PCR foi sequenciado e avaliado nos programas Blast, ClustalW e Mega 7.0. A partir da análise da filogenia foi observado que os isolados formaram um clado com os acessos da espécie Tomato chlorotic spot virus (TCSV). Este foi o primeiro relato de TCSV em alface no Estado do Pará
Resumo:
Apples are commercially grown in Brazil in a subtropical environment that favors the development of fungal diseases such as Glomerella leaf spot (GLS) caused mainly by Glomerella cingulata (anamorph Colletotrichum gloeosporioides). The main objective of this work was to evaluate the effect of mixed infections by Apple stem grooving virus (ASGV) and Apple stem pitting virus (ASPV) on the infection and the colonization processes of C. gloeosporiodes in cv. Maxi Gala plants. Leaves of 16-month-old potted plants were spray-inoculated and both the disease incidence and lesion count were monitored over time and leaf severity was assessed in the final evaluation using an image analysis tool. Results showed that initial infection estimated from a monomolecular model fitted to progress of lesion count was higher and the incubation period (time to reach 50% incidence) was on average 10 h shorter in virus-infected plants compared to non-infected plants. It is hypothesized that initial events such as conidial germination and fungal penetration into plant cells were facilitated by the presence of viral infection. Also, final GLS severity was significantly higher in the virus-infected plants. Mixed infections by ASGV/ASPV seemed to make apple leaves more susceptible to the initial infection and colonization by C. gloeosporioides.
Resumo:
La pubblicità – quella televisiva passando poi a quella sul web e sui social – subisce numerose trasformazioni che investono soprattutto i metodi comunicativi con cui sviluppare la propria narrazione. Oggi, di fatto, il mondo della pubblicità non si limita alla sola sponsorizzazione di un brand e dei suoi prodotti, ma si cala sempre più nelle dinamiche sociali, civili ed economiche che caratterizzano il nostro quotidiano. La comunicazione commerciale, dunque, si prefigge di essere il più inclusiva possibile, di coinvolgere storie, situazioni e personaggi che, nella pubblicità del “passato”, sarebbero stati esclusi totalmente o rappresentati in modo stereotipato. Se risulta possibile affermare che, nel panorama mediale odierno, si stia rivolgendo maggiore attenzione alle tematiche LGBTQ+, alle lotte contro la discriminazione di genere e all’ingaggio di personaggi appartenenti alla comunità queer, è altrettanto vero affermare come sia ancora possibile ricadere in rappresentazioni stereotipate e strategie di marketing che si fingono inclusive, solo per cavalcare l’onda del successo di eventi quali il Pride. All’interno di questo elaborato si andrà, in primis, a tracciare la storia culturale della comunità LGBTQ+ e ad approfondire come sia evoluta la sua presenza nei diversi media audiovisivi – dal cinema alle serie tv fino alla pubblicità. Ci si concentrerà poi sugli stereotipi ancora ricorrenti in pubblicità televisiva, ossia quello di genere. L’obiettivo della tesi è verificare se sia giusto parlare di inclusione o se si tratti solo una mera strategia di marketing, ossia di rainbow-washing, quando i brand si avvalgono di immagini e di personaggi LGBTQ+ nei propri spot. Nel capitolo finale, attraverso di un’analisi qualitativa di n. 100 spot televisivi americani, si andranno ad evidenziare i trend LGBTQ+, ossia in che modo oggi le pubblicità statunitensi sviluppano immagini, simboli, personaggi e storie LGBTQ+, realmente positive ed inclusive, in pubblicità.
Resumo:
Rapidity-odd directed flow (v1) measurements for charged pions, protons, and antiprotons near midrapidity (y=0) are reported in sNN=7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV Au+Au collisions as recorded by the STAR detector at the Relativistic Heavy Ion Collider. At intermediate impact parameters, the proton and net-proton slope parameter dv1/dy|y=0 shows a minimum between 11.5 and 19.6 GeV. In addition, the net-proton dv1/dy|y=0 changes sign twice between 7.7 and 39 GeV. The proton and net-proton results qualitatively resemble predictions of a hydrodynamic model with a first-order phase transition from hadronic matter to deconfined matter, and differ from hadronic transport calculations.
Resumo:
To compare variations in bone mineral density (BMD) and body composition (BC) in depot-medroxyprogesterone acetate (DMPA) users and nonusers after providing counselling on healthy lifestyle habits. An exploratory study in which women aged 18 to 40 years participated: 29 new DMPA users and 25 new non-hormonal contraceptive users. All participants were advised on healthy lifestyle habits: sun exposure, walking and calcium intake. BMD and BC were assessed at baseline and 12 months later. Statistical analysis included the Mann-Whitney test or Student's t-test followed by multiple linear regression analysis. Compared to the controls, DMPA users had lower BMD at vertebrae L1 and L4 after 12 months of use. They also had a mean increase of 2 kg in total fat mass and an increase of 2.2% in body fat compared to the non-hormonal contraceptive users. BMD loss at L1 was less pronounced in DMPA users with a calcium intake ≥ 1 g/day compared to DMPA users with a lower calcium intake. DMPA use was apparently associated with lower BMD and an increase in fat mass at 12 months of use. Calcium intake ≥ 1 g/day attenuates BMD loss in DMPA users. Counselling on healthy lifestyle habits failed to achieve its aims.
Resumo:
We report the STAR measurements of dielectron (e(+)e(-)) production at midrapidity (|y(ee)|<1) in Au+Au collisions at √[s(NN)]=200 GeV. The measurements are evaluated in different invariant mass regions with a focus on 0.30-0.76 (ρ-like), 0.76-0.80 (ω-like), and 0.98-1.05 (ϕ-like) GeV/c(2). The spectrum in the ω-like and ϕ-like regions can be well described by the hadronic cocktail simulation. In the ρ-like region, however, the vacuum ρ spectral function cannot describe the shape of the dielectron excess. In this range, an enhancement of 1.77±0.11(stat)±0.24(syst)±0.33(cocktail) is determined with respect to the hadronic cocktail simulation that excludes the ρ meson. The excess yield in the ρ-like region increases with the number of collision participants faster than the ω and ϕ yields. Theoretical models with broadened ρ contributions through interactions with constituents in the hot QCD medium provide a consistent description of the dilepton mass spectra for the measurement presented here and the earlier data at the Super Proton Synchrotron energies.
Resumo:
Local parity-odd domains are theorized to form inside a quark-gluon plasma which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect. The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this Letter, we present the results of the beam-energy dependence of the charge correlations in Au+Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39, and 62.4 GeV from the STAR experiment. After background subtraction, the signal gradually reduces with decreased beam energy and tends to vanish by 7.7 GeV. This implies the dominance of hadronic interactions over partonic ones at lower collision energies.
Resumo:
We report measurements of single- and double-spin asymmetries for W^{±} and Z/γ^{*} boson production in longitudinally polarized p+p collisions at sqrt[s]=510 GeV by the STAR experiment at RHIC. The asymmetries for W^{±} were measured as a function of the decay lepton pseudorapidity, which provides a theoretically clean probe of the proton's polarized quark distributions at the scale of the W mass. The results are compared to theoretical predictions, constrained by polarized deep inelastic scattering measurements, and show a preference for a sizable, positive up antiquark polarization in the range 0.05
Resumo:
We report the first measurements of the moments--mean (M), variance (σ(2)), skewness (S), and kurtosis (κ)--of the net-charge multiplicity distributions at midrapidity in Au+Au collisions at seven energies, ranging from sqrt[sNN]=7.7 to 200 GeV, as a part of the Beam Energy Scan program at RHIC. The moments are related to the thermodynamic susceptibilities of net charge, and are sensitive to the location of the QCD critical point. We compare the products of the moments, σ(2)/M, Sσ, and κσ(2), with the expectations from Poisson and negative binomial distributions (NBDs). The Sσ values deviate from the Poisson baseline and are close to the NBD baseline, while the κσ(2) values tend to lie between the two. Within the present uncertainties, our data do not show nonmonotonic behavior as a function of collision energy. These measurements provide a valuable tool to extract the freeze-out parameters in heavy-ion collisions by comparing with theoretical models.