Tensor coupling and pseudospin symmetry in nuclei

In this work we study the contribution of the isoscalar tensor coupling to the realization of pseudospin symmetry in nuclei. Using realistic values for the tensor coupling strength, we show that this coupling reduces noticeably the pseudospin splittings, especially for single-particle levels near the Fermi surface. By using an energy decomposition of the pseudospin energy splittings, we show that the changes in these splittings come by mainly through the changes induced in the lower radial wave function for the low-lying pseudospin partners, and by changes in the expectation value of the pseudospin-orbit coupling term for surface partners. This allows us to confirm the conclusion already reached in previous studies, namely that the pseudospin symmetry in nuclei is of a dynamical nature.Comment: 11 pages, 5 figures, uses REVTeX macro

An electrochemical impedance study of hydrogen evolution and absorption on Sn-modified steel electrodes

In this work we report results related to hydrogen evolution and absorption, on AISI 1045 steel and AISI 1045 steel modified by Sn electrodeposition, in 1 M NaOH. The simulation of experimental impedance, steady-state j/E data and electrochemical permeation data in terms of the Volmer–Heyrovsky mechanism coupled to H absorption and diffusion, allowed the estimation of kinetic and transport parameters leading to an appropriate interpretation of diminished H absorption on Sn modified samples.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Relevance of pseudospin symmetry in proton-nucleus scattering

The manifestation of pseudospin-symmetry in proton-nucleus scattering is discussed. Constraints on the pseudospin-symmetry violating scattering amplitude are given which require as input cross section and polarization data, but no measurements of the spin rotation function. Application of these constraints to p-58Ni and p-208Pb scattering data in the laboratory energy range of 200 MeV to 800 MeV, reveals a significant violation of the symmetry at lower energies and a weak one at higher energies. Using a schematic model within the Dirac phenomenology, the role of the Coulomb potential in proton-nucleus scattering with regard to pseudospin symmetry is studied. Our results indicate that the existence of pseudospin-symmetry in proton-nucleus scattering is questionable in the whole energy region considered and that the violation of this symmetry stems from the long range nature of the Coulomb interaction.Comment: 22 pages including 9 figures, correction of 1 reference, revision of abstract and major modification of chapter 4, Fig. 6, and Fig. 7; addition of Fig. 8 and Fig.

Relating pseudospin and spin symmetries through charge conjugation and chiral transformations: the case of the relativistic harmonic oscillator

We solve the generalized relativistic harmonic oscillator in 1+1 dimensions, i.e., including a linear pseudoscalar potential and quadratic scalar and vector potentials which have equal or opposite signs. We consider positive and negative quadratic potentials and discuss in detail their bound-state solutions for fermions and antifermions. The main features of these bound states are the same as the ones of the generalized three-dimensional relativistic harmonic oscillator bound states. The solutions found for zero pseudoscalar potential are related to the spin and pseudospin symmetry of the Dirac equation in 3+1 dimensions. We show how the charge conjugation and $\gamma^5$ chiral transformations relate the several spectra obtained and find that for massless particles the spin and pseudospin symmetry related problems have the same spectrum, but different spinor solutions. Finally, we establish a relation of the solutions found with single-particle states of nuclei described by relativistic mean-field theories with scalar, vector and isoscalar tensor interactions and discuss the conditions in which one may have both nucleon and antinucleon bound states.Comment: 33 pages, 10 figures, uses revtex macro

Estudo Clínico da Utilização da Válvula de Ahmed no Glaucoma Refractário Entre Janeiro de 2010 e Junho de 2012 no CHLC, EPE

Objectivo: Avaliar os resultados clínicos nos doentes submetidos a implante de válvula de Ah- med no serviço de Oftalmologia do Centro Hospitalar de Lisboa Central, EPE, entre Janeiro de 2010 e Junho de 2012. Material e Métodos: Estudo retrospectivo em que 39 doentes (44 válvulas) foram incluídos. Os critérios de inclusão compreenderam o diagnóstico de glaucoma refractário à terapêutica máxi- ma tolerada e/ou falência de trabeculectomia prévia. Os doentes foram incluídos em 3 grupos com mínimo de follow up de 1, 6 e 12 meses. O sucesso cirúrgico foi definido como 6mmhg ≤ pressão intraocular (PIO) ≤ 21mmHg, com ou sem o uso de medicação, sem cirurgia de glauco- ma adicional, e visão de percepção luminosa ou melhor. Resultados: O glaucoma neovascular foi o diagnóstico mais frequente (47,7%). A PIO média pré-operatória foi de 34,2mmHg (±8,37) e a pós-operatória foi de 17,1mmHg ±6,18 (1mês), 16,7mmHg ±3,72 (6 meses) e 17,0mmHg ±7,22 (1 ano). A diferença entre a PIO pré e pós-opera- tória foi estatisticamente significativa (p 0.05). A média de fárma- cos diminuiu de 3,43 (±1,14) para 1,75 (±1,50) após a cirurgia (p <0.0001). A taxa de sucesso foi de 77,3% ao 1o mês, 76,9% ao 6amês e 70,6% aos 12 meses. As principais complicações foram hipotonia em 6 casos (13,6%), perda de percepção luminosa em 4 (9,1%) e hifema em 2 (4,6%). Conclusões: A taxa de sucesso foi comparável à de estudos prévios. A válvula de Ahmed é um método eficaz e seguro no tratamento do glaucoma refractário.info:eu-repo/semantics/publishedVersio

Detecção de ovino sororreagente para Maedi-Visna no estado de Sergipe.

Resumo - O vírus da Maedi-Visna pertence à família Retroviridae, gênero Lentivírus e afeta ovinos criados especialmente de forma intensiva. Apesar de variável patogenicidade, é responsável por manifestação clínica crônica e debilitante. Amplamente distribuído pelo mundo, é relacionado a subestimado impacto econômico na ovinocultura, porém com dados imprecisos no Brasil. O presente trabalho objetivou a obtenção da prevalência da Maedi-Visna no município de Lagarto/Sergipe. Foram analisadas 151 amostras séricas de ovinos Santa Inês, oriundas de nove propriedades rurais, identificadas quanto ao sexo e idade dos animais. Utilizou-se o teste de Imunodifusão em Gel de Ágar através da técnica de microaglutinação. A prevalência obtida foi de 0,66%, o que representa o primeiro relato da Maedi-Visna em Sergipe e que pode estar correlacionado ao íntimo contato entre ovinos e caprinos ou a submissão dos animais às exposições agropecuárias, inclusive extra-estaduais, onde há a aproximação de animais infectados e sadios promovida de forma inconsciente pelos produtores, ou ainda à transmissão a partir de animais exóticos inseridos em rebanho para melhoramento genético. Devido ao sistema de criação ao qual os animais são mantidos, confinamento de reprodutores e regime semi-intensivo aos demais, a doença pode não ter conseguido condições propicias para disseminar-se. O resultado indica riscos à ovinocultura desenvolvida no estado e as relações comerciais com os demais, e sugere a necessidade de estudos mais amplos para melhor caracterizar o perfil do estado em relação à ocorrência de Lentiviroses de Pequenos Ruminantes e implantação de medidas de controle e prevenção da disseminação desta enfermidade. Detection of sheep sororeaction for maedi-visna in State of Sergipe. Abstract - The virus of Maedi Visna belongs to Retroviridae family, gender Lentivirus affects raise of sheep especially at intensive way. Despite variable pathogenicity, is responsible for chronic and debilitating clinical. Widely distributed throughout the world, is linked underestimated the economic impact in raise of sheep, but with inaccurate data in Brazil. This study aimed to obtain the prevalence of Maedi Visna in the municipality of Lagarto / Sergipe. It were analyzed 151 samples of serum taken from sheep of Santa Ines breed, from nine farms, identified as to sex and age of animals. It was used in the test of Imunodifusion in Agar Gel whith microaglutination technique. The prevalence obtained was 0.66%, which represents the first report of Maedi Visna in Sergipe and can be correlated to the close contact between sheep and goats or the submission of animals for agricultural exhibitions where there is the nearest of infected and healthy animals unconscious promoted by producers or the transmission from exotic animals entered in farms for breeding herd. Because the system of creation which animals are kept, confinement of males and semi-intensive system to the others, the disease may not have achieved favorable conditions to spread itself. The results indicates the risk in raised of sheep developed in the state and trade relations with the others, and suggests the need for more extensive studies to better characterize the profile of the state in relation to the occurrence of Lentiviroses of Small Ruminants and implementation of measures for control and prevention spread of this disease

'Diverse mobilities': second-generation Greek-Germans engage with the homeland as children and as adults

This paper is about the children of Greek labour migrants in Germany. We focus on two life-stages of ‘return’ for this second generation: as young children brought to Greece on holidays or sent back for longer periods, and as young adults exercising an independent ‘return’ migration. We draw both on literature and on our own field interviews with 50 first- and second-generation Greek-Germans. We find the practise of sending young children back to Greece to have been surprisingly widespread yet little documented. Adult relocation to the parental homeland takes place for five reasons: (i) a ‘search for self’; (ii) attraction of the Greek way of life; (iii) the actualisation of the ‘family narrative of return’ by the second, rather than the first, generation; (iv) life-stage events such as going to university or marrying a Greek; (v) escape from a traumatic event or oppressive family situation. Yet the return often brings difficulties, disillusionment, identity reappraisal, and a re-evaluation of the German context

A care bundle approach for prevention of ventilator-associated pneumonia

AbstractImplementation of care bundles for prevention of ventilator-associated pneumonia (VAP) and its impact on patient outcomes requires validation with long-term follow-up. A collaborative multi-centre cohort study was conducted in five Spanish adult intensive-care units. A care bundle approach based on five measures was implemented after a 3-month baseline period, and compliance, VAP rates, intensive-care unit length of stay (ICU LOS) and duration of mechanical ventilation were prospectively recorded for 16 months. There were 149 patients in the baseline period and 885 after the intervention. Compliance with all measures after intervention was <30% (264/885). In spite of this, VAP incidence decreased from 15.5% (23/149) to 11.7% (104/885), after the intervention (p <0.05). This reduction was significantly associated with hand hygiene (OR = 0.35), intra-cuff pressure control (OR = 0.21), oral hygiene (OR = 0.23) and sedation control (OR = 0.51). Use of the care bundle was associated with an incidence risk ratio of VAP of 0.78 (95% CI 0.15–0.99). We documented a reduction of median ICU LOS (from 10 to 6 days) and duration of mechanical ventilation (from 8 to 4 days) for patients with full bundle compliance (intervention period). Efforts on VAP prevention and outcome improvement should focus on achieving higher compliance in hand and oral hygiene, sedation protocols and intracuff pressure control

Specific heat and magnetic measurements in Nd0.5Sr0.5MnO3, Nd0.5Ca0.5MnO3 and Ho0.5Ca0.5MnO3 samples

We studied the magnetization as a function of temperature and magnetic field in the compounds Nd0.5Sr0.5MnO3, Nd0.5Ca0.5MnO3 and Ho0.5Ca0.5MnO3. It allowed us to identify the ferromagnetic, antiferromagnetic and charge ordering phases in each case. The intrinsic magnetic moments of Nd3+ and Ho3+ ions experienced a short range order at low temperatures. We also did specific heat measurements with applied magnetic fields between 0 and 9 T and temperatures between 2 and 300 K in all three samples. Close to the charge ordering and ferromagnetic transition temperatures the specific heat curves showed peaks superposed to the characteristic response of the lattice oscillations. Below 10 K the specific heat measurements evidenced a Schottky-like anomaly for all samples. However, we could not successfully fit the curves to either a two level nor a distribution of two-level Schottky anomaly. Our results indicated that the peak temperature of the Schottky anomaly was higher in the compounds with narrower conduction band.Comment: submitted to PR

Jasmonic acid and K-phosphite enhance productivity and technological quality of sugarcane crop.

Abstract: Plant resistance inducers are cost-effective and environmentally pleasing strategies of plant protection to mitigate biotic and abiotic agents threatening food safety and energy security. We, accordingly, present jasmonic acid and k-phosphite as low-cost strategies to enhance productive yield and technological quality of sugarcane crop. Exogenously treatment of the sugarcane variety SP81-3250 consisted of carrying out foliar application of jasmonic acid at 1, 1.5 and 2 ml L-1 and K-phosphite at 2, 4 and 6 ml L-1 before crop flowering. Interestingly, both systemic phytorregulator and foliar fertilizer at the lowest doses significantly improved contents of total soluble solids and sucrose, as well as productive yield of fermentable sugars. Jasmonic acid could promote growth and development by triggering either non-enzymatic or enzymatic mechanisms in the host self-defense system to support of external stresses, including herbivory by sugarcane-borer. K-phosphite could improve crop performance by not only releasing water-soluble inorganic ions like phosphorus and potash, but also by signaling synthesis of phytoalexins. Purity of cane juice and productivity of stalks sharply decreased, as the doses of the plant-resistance inducers increased. Jasmonic acid and k-phosphite at unbalanced endogenous levels could inhibit physiological ripening and specific enzymatical activity of alkaline invertases and sucrose-phosphate synthase, thereby influencing bioavailability of sucrose. The lower the sucrose content, the poorer the technological quality of sugarcane crop. The conclusion is, therefore, jasmonic acid and K-phosphite at lower doses prove to be effective induced resistance techniques to produce richer feedstock, with potential to produce ethanol fuel and refined sugar in sugar-energy plants