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

(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 disponíveis 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 doprincípio de Aprendizagem ao Longo da Vida (ALV). Como palavras-chave destaque paraeducação e formação de adultos e aprendizagem ao longo da vida

Primary Sjögren's syndrome in children: Is a family approach indicated?

[No abstract available

Genes from the TAS1R and TAS2R families of taste receptors: Looking for signatures of their adaptive role in human evolution

Taste perception is crucial in monitoring food intake and, hence, is thought to play a significant role in human evolution. To gain insights into possible adaptive signatures in genes encoding bitter, sweet, and umami taste receptors, we surveyed the available sequence variation data from the 1000 Genomes Project Phase 3 for TAS1R (TAS1R1-3) and TAS2R (TAS2R16 and TAS2R38) families. Our study demonstrated that genes from these two families have experienced contrasting evolutionary histories: While TAS1R1 and TAS1R3 showed worldwide evidence of positive selection, probably correlated with improved umami and sweet perception, the patterns of variation displayed by TAS2R16 and TAS2R38 were more consistent with scenarios of balancing selection that possibly conferred a heterozygous advantage associated with better capacity to perceive a wide range of bitter compounds. In TAS2R16, such adaptive events appear to have occurred restrictively in mainland Africa, whereas the strongest evidence in TAS2R38 was detected in Europe. Despite plausible associations between taste perception and the TAS1R and TAS2R selective signatures, we cannot discount other biological mechanisms as driving the evolutionary trajectories of those TAS1R and TAS2R members, especially given recent findings of taste receptors behaving as the products of pleiotropic genes involved in many functions outside the gustatory system.IPATIMUP is included in the i3S Consortium, which is partially supported by the Portuguese Foundation for Science and Technology (FCT). This work is also funded by FEDER funds through the Operational Programme Competitiveness Factors (COMPETE) and National Funds through the FCT (projects PEst-C/SAU/LA0003/2013 and POCI-01-0145-FEDER-007274, fellowships SFRH/BD/63343/2009 to C.V., SFRH/ BPD/65000/2009 to L.A., and SFRH/BPD/120777/2016 to P.I.M.), and by Programa Operacional Regional do Norte (Norte 2020), through FEDER funds under the Quadro de Referência Estratégico Nacional (QREN; NORTE-01-0145-FEDER-000029). We thank Jacquelyn Beals for the careful editing of the work. We also thank Sònia Casillas for the helpful instructions about the tracks from the PopHuman browser, and Miguel Arenas and Eduardo Conde Sousa for the aid in extracting data from those tracks