588 research outputs found
The quantum information manifold for epsilon-bounded forms
Let H be a self-adjoint operator bounded below by 1, and let V be a small
form perturbation such that RVS has finite norm, where R is the resolvent at
zero to the power 1/2 +epsilon, and S is the resolvent to the power
1/2-epsilon. Here, epsilon lies between 0 and 1/2. If the Gibbs state defined
by H is sufficiently regular, we show that the free energy is an analytic
function of V in the sense of Frechet, and that the family of density operators
defined in this way is an analytic manifold modelled on a Banach space.Comment: 12 pages, report to Torun Conference, 199
Assessment of soil water, carbon and nitrogen cycling in reseeded grassland on the North Wyke Farm Platform using a process-based model
The North Wyke Farm Platform (NWFP) generates large volumes of temporally-indexed data that provides a valuable test-bed for agricultural mathematical models in temperate grasslands. In our study, we used the primary datasets generated from the NWFP (https://nwfp.rothamsted.ac.uk/) to validate the SPACSYS model in terms of the dynamics of water loss and forage dry matter yield estimated through cutting. The SPACSYS model is capable of simulating soil water, carbon (C) and nitrogen (N) balance in the soil-plant-atmosphere system. The validated model was then used to simulate the responses of soil water, C and N to reseeding grass cultivars with either high sugar (Lolium perenne L cv. AberMagic) or deep rooting (Festulotium cv. Prior) traits. Simulation results demonstrated that the SPACSYS model could predict reliably soil water, C and N cycling in reseeded grassland. Compared to AberMagic, the Nor grass could fix more C in the second year following reseeding, whereas less C was lost through soil respiration in the first transition year. In comparison to the grass cifitivar of the permanent pasture that existed before reseeding, both grasses reduced N losses through runoff and conhibuted to reducing water loss, especially Prior in relation to the latter. The SPACSYS model could predict these differences as supported by the rich dataset from the NWFP, providing a tool for future predictions on less characterized pasture. (C) 2017 The Authors. Published by Elsevier B.V. This is an open access articleRN the CC BY licens
Ramsar Wetlands of International Importance–improving conservation outcomes
The Ramsar Convention (or the Convention on Wetlands), signed in 1971, was one of the first international conservation agreements, promoting global wise use of wetlands. It has three primary objectives: national designation and management of wetlands of international importance; general wise use of wetlands; and international cooperation. We examined lessons learnt for improving wetland conservation after Ramsar’s nearly five decades of operation. The number of wetlands in the Ramsar Site Network has grown over time (2,391 Ramsar Sites, 2.5 million km2, as at 2020-06-09) but unevenly around the world, with decreasing rate of growth in recent decades. Ramsar Sites are concentrated in countries with a high Gross Domestic Product and human pressure (e.g., western Europe) but, in contrast, Ramsar Sites with the largest wetland extent are in central-west Africa and South America. We identified three key challenges for improving effectiveness of the Ramsar Site Network: increasing number of sites and wetland area, improved representation (functional, geographical and biological); and effective management and reporting. Increasing the number of sites and area in the Ramsar network could benefit from targets, implemented at national scales. Knowledge of representativeness is inadequate, requiring analyses of functional ecotypes, geographical and biological representativeness. Finally, most countries have inadequate management planning and reporting on the ecological character of their Ramsar Sites, requiring more focused attention on a vision and objectives, with regular reporting of key indicators to guide management. There are increasing opportunities to rigorously track ecological character, utilizing new tools and available indicators (e.g., remote sensing). It is critical that the world protect its wetlands, with an effective Ramsar Convention or the Convention on Wetlands at the core
Solar photo-Fenton at mild conditions to treat a mixture of six emerging pollutants
The applicability of photo-Fenton to degrade a mixture of emerging pollutants (EPs) namely amoxycillin,
acetaminophen, acetemiprid, caffeine, clofibric acid and carbamazepine has been studied at different scenarios.
At high concentrations, acidic photo-Fenton was able to achieve a fast removal of the EPs.
Although, complete mineralization was not reached, the toxicity of the solution was decreased according
to the respiration of activated sludge and luminescence of Vibrio fischeri assays, although according to this
last assay a transitory enhancement of the toxicity was found, attributable to the formation of toxic byproducts
such as phenols, chlorophenols and chlorinated pyrydines. Experiments carried out with 5 mg/l
of each EP showed that at neutral media the process was two orders of magnitude less efficient than at
acidic pH, although it was still able to remove the EPs. The aqueous matrix has a remarkable effect on the
process as the presence of humic acids increased the reaction rate and inorganic salts played an inhibitory
role. Finally, experiments performed with 10 lg/l of each EP showed that under those experimental conditions
nearly complete removal of the EPs was reached with neutral photo-Fenton after 120 min of irradiation;
in this case, humic substances played a disfavorable role.We want to thank the financial support of Spanish Ministerio de Ciencia e Innovacion (CTQ 2009-13459-0O5-03) and (CTQ 2009-3459-C05-01).Bernabeu García, A.; Palacios Guillem, S.; Vicente Candela, R.; Vercher Pérez, RF.; Malato Rodríguez, S.; Arques Sanz, A.; Amat Payá, AM. (2012). Solar photo-Fenton at mild conditions to treat a mixture of six emerging pollutants. Chemical Engineering Journal. 198:65-72. https://doi.org/10.1016/j.cej.2012.05.056S657219
Uso de plasma rico em plaquetas intra-articulares como tratamento pós-cirúrgico da ruptura do ligamento cruzado cranial num cão
Active Galactic Nuclei at the Crossroads of Astrophysics
Over the last five decades, AGN studies have produced a number of spectacular
examples of synergies and multifaceted approaches in astrophysics. The field of
AGN research now spans the entire spectral range and covers more than twelve
orders of magnitude in the spatial and temporal domains. The next generation of
astrophysical facilities will open up new possibilities for AGN studies,
especially in the areas of high-resolution and high-fidelity imaging and
spectroscopy of nuclear regions in the X-ray, optical, and radio bands. These
studies will address in detail a number of critical issues in AGN research such
as processes in the immediate vicinity of supermassive black holes, physical
conditions of broad-line and narrow-line regions, formation and evolution of
accretion disks and relativistic outflows, and the connection between nuclear
activity and galaxy evolution.Comment: 16 pages, 5 figures; review contribution; "Exploring the Cosmic
Frontier: Astrophysical Instruments for the 21st Century", ESO Astrophysical
Symposia Serie
Radiative Cooling in MHD Models of the Quiet Sun Convection Zone and Corona
We present a series of numerical simulations of the quiet Sun plasma threaded
by magnetic fields that extend from the upper convection zone into the low
corona. We discuss an efficient, simplified approximation to the physics of
optically thick radiative transport through the surface layers, and investigate
the effects of convective turbulence on the magnetic structure of the Sun's
atmosphere in an initially unipolar (open field) region. We find that the net
Poynting flux below the surface is on average directed toward the interior,
while in the photosphere and chromosphere the net flow of electromagnetic
energy is outward into the solar corona. Overturning convective motions between
these layers driven by rapid radiative cooling appears to be the source of
energy for the oppositely directed fluxes of electromagnetic energy.Comment: 20 pages, 5 figures, Solar Physics, in pres
Risk Factors for Nipah Virus Encephalitis in Bangladesh1
Patients in Goalando were likely infected by direct contact with fruit bats or their secretions, rather than through contact with an intermediate host
School dropout, problem behaviour and poor academic achievement : a longitudinal view of portuguese male offenders
This study examines school drop outs from the perspective of male adults
themselves through interviews with offenders currently serving sentences. Participants
were 10 Portuguese male inmates, between the ages of 19 and 46 years of age,
incarcerated in two prison facilities of the Azores. Qualitative and interpretative methods
were carried out using a semi-structured in-depth individual interview that was audiorecorded
and conducted on the basis of a list of topics. Interview transcripts and thematic
analysis were used in data treatment and analysis. The findings primarily indicate that
poor academic achievement and emotional and behavioural difficulties of participants
played a particular role in early school drop out. The trajectories these individuals
followed within the education system presented problem behaviour, learning disabilities,
and/or foster care interventions. While school drop out circumstances were apparently
various, analysis showed that they were underpinned by three distinct sets of conditions
generally not addressed by the education system. The analysis of the triggering factors
and the maintenance dynamics of school drop outs indicated three distinct types:
retention/absenteeism, life turning points and positive resolution. Implications for
secondary prevention and screening practices are discussed.FCT (SFRH/ BD/ 44245/ 2008)CIEC - unidade de investigação 317 da FC
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