944 research outputs found
Fate of topological states in incommensurate generalized Aubry-Andr\'e models
We study one-dimensional optical lattices described by generalized
Aubry-Andr\'e models that include both commensurate and incommensurate
modulations of the hopping amplitude. This brings together two interesting
features of this class of systems: Anderson localization and the existence of
topological edge states. We follow changes of the single-particle energy
spectrum induced by variations of the system parameters, with focus on the
survival of topological states in the localized regime.Comment: 5 pages, 5 figure
Ground-states of spin-1 bosons in asymmetric double-wells
In this work we investigate the different states of a system of spin-1 bosons
in two potential wells connected by tunneling, with spin-dependent interaction.
The model utilizes the well-known Bose-Hubbard Hamiltonian, adding a local
interaction term that depends on the modulus of the total spin in a well,
favoring a high- or low-spin state for different signs of the coupling
constant. We employ the concept of fidelity to detect critical values of
parameters for which the ground state undergoes significant changes. The nature
of the states is investigated through evaluation of average occupation numbers
in the wells and of spin correlations. A more detailed analysis is done for a
two-particle system, but a discussion of the three-particle case and some
results for larger numbers are also presented.Comment: 7 pages, 10 figure
Finite-size effects in Anderson localization of one-dimensional Bose-Einstein condensates
We investigate the disorder-induced localization transition in Bose-Einstein
condensates for the Anderson and Aubry-Andre models in the non-interacting
limit using exact diagonalization. We show that, in addition to the standard
superfluid fraction, other tools such as the entanglement and fidelity can
provide clear signatures of the transition. Interestingly, the fidelity
exhibits good sensitivity even for small lattices. Effects of the system size
on these quantities are analyzed in detail, including the determination of a
finite-size-scaling law for the critical disorder strength in the case of the
Anderson model.Comment: 15 pages, 7 figure
Assessment of CO2 emissions during acidification, storage and after incorporation to soil of pig slurry
RAMIRAN International ConferenceLarge amounts of pig slurry are produced each year in Portugal leading to environmental problems such as water
and air pollution. Previous studies have reported that livestock production is the main source of anthropogenic
ammonia (NH3) emissions in Europe (Kai et al., 2008) and an important source of greenhouse gases (Weiske and
Petersen, 2006). Effluent treatment has been promoted to improve slurry management and to reduce its
environmental impact (Sommer and Hutchings, 2001, Fangueiro et al., 2008a). Solid-liquid separation of slurry is a
useful tool at the farm level producing valuable fractions, a liquid that can be used for direct fertilisation and a solid
fraction that can be composted (Fangueiro et al., 2008b). Alternatively, acidification of slurry has been proposed to
reduce ammonia (NH3) emissions during storage and field application (Kai et al., 2008). Previous works
(Misselbrook et al., 2005; Fangueiro et al., 2008a) reported that higher NH3 emissions occurred during storage of
liquid fraction of slurry or manure with low dry matter content, probably due to a reduced crust formation that
decreases NH3 emissions. Hence, acidification of the liquid fraction of slurry is strongly recommended. Slurry
acidification is common practice in The Netherlands and Denmark (Schils et al., 1999; Eriksen et al., 2008) but this
technology still needs to be improved to avoid hazards. It is expected that this technology will be used in more
countries since the European Directive (2001/81/CE) demands a decrease of atmospheric pollutants such as NH3:
targets for lower NH3 emissions have been already set in Spain (Castrillon et al., 2009). Nevertheless, the
acidification process leads to significant carbon dioxide (CO2) emissions (Vandré and Clemens, 1997). Such CO2
release is problematic when a closed system of slurry acidification is used (when acidified slurry is flushed back to
pig houses) since it may lead to foam formation (Vandré and Clemens, 1997; Borst, 2001). Nevertheless, Fangueiro
et al. (2010) reported that acidification of slurry or derived fractions led to a decrease in CO2 emissions following
soil addition relative to non acidified materials.
The aim of the present work was to measure the CO2 emissions during the acidification process of the
liquid fraction of pig slurry and its subsequent impact during storage and after soil incorporation
New sequence variants detected at DXS10148, DXS10074 and DXS10134 loci
A great amount of population and forensic genetic data are available for X-STRs supporting the need for
having a common and accurate nomenclature among laboratories allowing for better communication,
data exchange, and data comparison. DXS10148, DXS10074 and DXS10134 are commonly used X-STRs
particularly due to their inclusion in the commercial kit Investigator Argus X-12 (Qiagen). Samples from
West Africa and Iraq were sequenced for all three X-STRs allowing the detection of new DNA sequence
variants. At DXS10148, variation was detected at four bases downstream from the flanking region from
the repeat motif. The sequence AAGG-AAAG has been detected for the first time as a varying (AAGGAAAG)1–3 motif, in the present work. One additional string when compared to the common one (AAGGAAAG)2 adds eight bases to the fragment size of the tetranucleotide STR. This means that 2 repeats are
added in these cases to the fragment size of the allele, while the presence of only one copy will reduce the
expected allele size by 2 repeats. At DXS10074 two varying stretches consisting of AC and AG dinucleotide
repeats were observed in the upstream flanking region, six bases from the main repeat core that also
influence the expected allele size. DXS10134 revealed a simpler nomenclature in the Guinea-Bissau
sample set when compared to the previously described allele nomenclature. This detected new hidden
variation also has impact on the actual allele nomenclature at this locus as it contributes to a new class of
short alleles so far undetected in other studies.info:eu-repo/semantics/publishedVersio
Effects of band filling in the Anderson-Falicov-Kimball model
In this work, we study the Anderson-Falicov-Kimball model within the dynamical mean field theory for the Bethe lattice, restricting our analysis to the nonmagnetic case. The one-particle density of states is obtained by both arithmetic and geometric averages over disorder, since only the latter can detect localization in the absence of an energy gap. Varying the strengths of Coulomb interaction and disorder at zero temperature, we construct phase diagrams for this model, where we distinguish spectral regions with localized states, with extended states, or with a correlation-induced gap. With this, we identify metal-insulator transitions driven by correlation and disorder, as well as the competition between these effects. This is done for various band fillings, since our main interest here is to study how the variation of the electron density affects the phase diagrams previously obtained for half-filling. The picture revealed by the density of states is further checked by evaluating the static and dynamic conductivities, including temperature effects
Medical Escort of Critical Care Patients in the Pre-Hospital Setting
Introduction: Pre-hospital emergency cases include the patient’s transportation to the hospital, with an adequate escort, when indicated.
In Portugal, secondary transport’s escort is guided by an escort score published by the Portuguese Medical Association’s Guidelines on the Critical Care Patient’s Transport (2008). This score (TS) defines three levels of escort: no medical escort (level A), doctor or nurse escort (level B), doctor and nurse escort (level C).
There is no published data on this score’s application to the pre-hospital setting. Such use could improve resource management in the pre-hospital emergency medical services, as it could support the need to involve a doctor and/or nurse in the patient’s escort to the hospital.
Our study’s aim is the evaluate the TS application to the pre-hospital context.
Study Methods: We gathered data from primary transports’ escorts between January 2015 and January 2017. We recorded whether the patient was taken to hospital or not, and if yes, the transport’s escort (Doctor, Doctor and Nurse, or only emergency technicians). Posteriorly, we calculated the TS for each of those transport records. Any records with incomplete escort data or where the score could not be calculated were excluded.
Using this data, we calculated Sensibility (Ss), Specificity (Sp), positive predicitive value (PPV) and negative predictive value (NPV) of the TS for the following situations: Escort by emergency technicians only (level A), escort by doctor or nurse (level B) or escort by doctor and nurse (level C)
Results and discussion: We found complete data regarding 556 primary transports 141 patients were escorted by emergency technicians only, 269 by doctor or nurse only, and 146 by a doctor and nurse.
TS level A was found to have Ss 85,78%, Sp 70,92%, PPV 89,67% and NPV 62,89% regarding escort by emergency technicians only. These values support the decision of taking no medical escort in a primary transport in the pre-hospital setting when TS is level A. On the other hand, TS level C has Ss 78,08%, Sp 59,72%, PPV 40,57% and NPV 88,36% regarding escort by both a doctor and nurse. These numbers are less clear regarding a decision to take a medical escort.
Conclusions: TS appears to be an indicator with enough Ss and Sp to help the pre-hospital team choose whether or not to escort the patient to the hospital with only emergency technicians or with a more differentiated escort, especially when the score’s result is Level A. But it cannot differentiate between doctor or nurse or both doctor and nurse when the result is level B or C.
More figures are needed to understand if this score can be implemented as a decision tool regarding the kind of medical escort a patient needs in a primary transport.info:eu-repo/semantics/publishedVersio
(Re)construção de Percursos Formativos ao Longo da Vida: O caso dos Cursos de Educação e Formação de Adultos (EFA)
Os Cursos de Educação e Formação de Adultos (adiante designados Cursos EFA), assumeme como uma das respostas formativas e de qualificação disponÃveis no sistema de educação e dequalificação em Portugal. Desde a sua criação, até à data, ocorreram alterações várias, sob oponto de vista legal, metodológico e pedagógico. Procurou-se efectuar uma breve descrição daoferta EFA, apontando-se duas dimensões: (i) a sua génese e evolução; (ii) as especificidades doeu modelo de formação/ estrutura curricular, relacionando essas dimensões com a importância doprincÃpio de Aprendizagem ao Longo da Vida (ALV). Como palavras-chave destaque paraeducação e formação de adultos e aprendizagem ao longo da vida
Influence of the particle size and animal slurry type on the potential of nitrogen mineralization after soil incorporation
RAMIRAN International ConferenceAnimal manures are rich in organic matter and nutrients, namely nitrogen (N) and, consequently, widely applied to
soil as organic fertilizers. However, a large part of the nitrogen contained in animal manures is in the organic form
and so not directly available for plants. Indeed, organic N has to be mineralized prior to plant uptake (Rees and
Castle, 2002). Several manure characteristics as the C:N ratio (Chadwick et al., 2000), the lignin content
(Kristensen, 1996) and the NH4 +/organic N ratio (Beauchamp and Paul, 1989) have been suggested as indicators of
the plant-available N. More recently, Fangueiro et al. (2008) showed that the potential of N mineralization (PNM) of
cattle slurry is inversely correlated with slurry particle size: finest fractions are the particle-size fractions from which
N mineralization occurs in slurries whereas coarser fractions are associated with immobilization. Furthermore,
Moller et al. (2002) reported that animal diet and anaerobic decomposition during storage in slurry channels and
stores affect the slurry particle size distribution. Such information is of great interest since the finest slurry particle
size should infiltrate the soil more easily and quickly relative to the coarser slurry particle size that should remain
close to soil surface. Furthermore, mechanical slurry separation is now performed in many pig and dairy farms in
order to improve slurry management in terms of nutrients utilization and reducing costs related to slurry storage.
Slurry separation by screw press leads to a nutrient rich organic solid fraction (0.7– 3.2 mm particles) that may be
composted and a liquid fraction that can be used for fertigation.
In the present study, three types of slurry (pig, duck and cattle) were separated into 4 slurry particle size
fractions (>2000 um, 2000-500 um, 500-100 um, <100 um) in order to assess the influence of the type of slurry and
slurry particle size on the PNM after soil incorporation
A new viewpoint on the etiopathogenesis of depression : insights from the neurophysiology of deep brain stimulation in Parkinson's Disease and treatment-resistant depression
Copyright © 2021 Silva-dos-Santos, Sales, Sebastião and Gusmão. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.In this opinion article, we humbly propose a new viewpoint on the etiopathogenesis of depression. We base the model on our interpretation of selected recent neurophysiological findings, mainly regarding Deep Brain Stimulation (DBS) to treat Parkinson’s Disease and also DBS to treat Treatment-Resistant Depression (TRD). We coin the idea a mental kindling-like mechanism. However, future clinical research, possibly complemented with human laboratory research or animal experiments, will be needed to test the validity of our proposed model. On the current manuscript framework, following the first and introductory section, we will set the stage by presenting selected studies and insights mainly from DBS to treat TRD and PD, on the second and middle section. Finally, we will discuss the proposed viewpoint on the third and last section of the present work.info:eu-repo/semantics/publishedVersio
- …