993 research outputs found
Exact vortex solutions in a CP^N Skyrme-Faddeev type model
We consider a four dimensional field theory with target space being CP^N
which constitutes a generalization of the usual Skyrme-Faddeev model defined on
CP^1. We show that it possesses an integrable sector presenting an infinite
number of local conservation laws, which are associated to the hidden
symmetries of the zero curvature representation of the theory in loop space. We
construct an infinite class of exact solutions for that integrable submodel
where the fields are meromorphic functions of the combinations (x^1+i x^2) and
(x^3+x^0) of the Cartesian coordinates of four dimensional Minkowski
space-time. Among those solutions we have static vortices and also vortices
with waves traveling along them with the speed of light. The energy per unity
of length of the vortices show an interesting and intricate interaction among
the vortices and waves.Comment: 21 pages, plain latex, no figure
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Freshwater transport in the coupled ocean-atmosphere system: a passive ocean
Conservation of water demands that meridional ocean and atmosphere freshwater transports (FWT) are of equal magnitude but opposite in direction. This suggests that the atmospheric FWT and its associated latent heat (LH) transport could be thought of as a \textquotedblleft coupled ocean/atmosphere mode\textquotedblright. But what is the true nature of this coupling? Is the ocean passive or active?
Here we analyze a series of simulations with a coupled ocean-atmosphere-sea ice model employing highly idealized geometries but with markedly different coupled climates and patterns of ocean circulation. Exploiting streamfunctions in specific humidity coordinates for the atmosphere and salt coordinates for the ocean to represent FWT in their respective medium, we find that atmospheric FWT/LH transport is essentially independent of the ocean state. Ocean circulation and salinity distribution adjust to achieve a return freshwater pathway demanded of them by the atmosphere. So, although ocean and atmosphere FWTs are indeed coupled by mass conservation, the ocean is a passive component acting as a reservoir of freshwater
Evaluation of rK39 rapid diagnostic tests for canine visceral leishmaniasis : longitudinal study and meta-analysis
Canine visceral leishmaniasis is a vector-borne disease caused by the intracellular parasite Leishmania infantum. It is an important veterinary disease, and dogs are also the main animal reservoir for human infection. The disease is widespread in the Mediterranean area, and parts of Asia and South and Central America, and is potentially fatal in both dogs and humans unless treated. Diagnosis of canine infections requires serological or molecular tests. Detection of infection in dogs is important prior to treatment, and in epidemiological studies and control programmes, and a sensitive and specific rapid diagnostic test would be very useful. Rapid diagnostic tests (RDTs) have been developed, but their diagnostic performance has been reported to be variable. We evaluated the sensitivity of a RDT based on serological detection of the rK39 antigen in a cohort of naturally infected Brazilian dogs. The sensitivity of the test to detect infection was relatively low, but increased with time since infection and the severity of infection. We then carried out a meta-analysis of published studies of rK39 RDTs, evaluating the sensitivity to detect disease and infection. The results suggest that rK39 RDTs may be useful in a veterinary clinical setting, but the sensitivity to detect infection is too low for operational control programmes
Resting energy expenditure in patients with cirrhosis: an individual patient data meta-analysis of indirect calorimetry versus established and derived prediction equations
Validity of current recommended daily energy intakes in people with cirrhosis based on individual patient data
Consórcios de caupi e milho em cultivo orgânico para produção de grãos e espigas verdes.
No período de outono-inverno-primavera de 2007, foi conduzido um estudo em Seropédica, Região Metropolitana do estado do Rio de Janeiro (Baixada Fluminense), com o objetivo de avaliar diferentes tipos de consórcio entre caupi (cv. Mauá) e milho (cv. AG-1051), em sistema orgânico de produção. O experimento foi instalado em área de Argissolo Vermelho-Amarelo no delineamento de blocos ao acaso, com quatro repetições. Os tratamentos constaram de diferentes épocas ou intervalos de tempo de semeadura do caupi em relação à do milho, a saber: (E1) 21 dias antes do milho; (E2) 14 dias antes do milho; (E3) 7 dias antes do milho; e (E4) no mesmo dia do milho. Tratamentos correspondentes aos cultivos solteiros do caupi e do milho foram incluídos, ambos semeados na data do tratamento E4. O cultivo consorciado com o caupi não interferiu na produtividade do milho em espigas verdes e também em termos de comprimento e diâmetro basal dessas espigas, independentemente do intervalo entre semeaduras. Com referência ao caupi, a produtividade em grãos verdes no cultivo solteiro foi superior à dos consórcios com o milho. Os valores obtidos para os Índices de Equivalência de Área (IEA), foram todos acima de 1,0, indicando que os consórcios foram eficientes quanto ao desempenho agronômico/biológico. Considerando, ainda a produtividade de cada cultura participante do consórcio, a semeadura do caupi antecipada de 21 dias em relação à do milho afigura-se mais adequada ao manejo orgânico adotado e às condições edafoclimáticas da região
The use of PCR-RFLP as an identification tool for two closely related species of bats of genus Platyrrhinus
Genomics, microRNA, epigenetics, and proteomics for future diagnosis, treatment and monitoring response in upper GI cancers
Speaker- versus listener-oriented disfluency: A re-examination of arguments and assumptions from autism spectrum disorder
We re-evaluate conclusions about disfluency production in high-functioning forms of autism spectrum disorder (HFA). Previous studies examined individuals with HFA to address a theoretical question regarding speaker- and listener-oriented disfluencies. Individuals with HFA tend to be self-centric and have poor pragmatic language skills, and should be less likely to produce listener-oriented disfluency. However, previous studies did not account for individual differences variables that affect disfluency. We show that both matched and unmatched controls produce fewer repairs than individuals with HFA. For silent pauses, there was no difference between matched controls and HFA, but both groups produced more than unmatched controls. These results identify limitations in prior research and shed light on the relationship between autism spectrum disorders and disfluent speech
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