242 research outputs found
Carotenoids from Phaffia rhodozyma: Antioxidant activity and stability of extracts
The main goal of this work was to establish the stability and antioxidant activity of the extracts obtained through different techniques for recovering carotenoids from Phaffia rhodozyma NRRL-Y 17268. The best conditions for extracting carotenoids through cell rupture with dimethylsulfoxide (DMSO) were found to be a particle size of 0.125 mm submitted to freezing temperature (-18°C) for 48 h (272 μg/g). For DMSO extracts, freezing negatively affected the antioxidant activity by 2,2 '-azinobis (3-ethyl benzothiazoline-6-sulfonic acid)) and DPPH (2,2-diphenyl-1-picrylhydrazyl (DPPH) methods. The carotenogenic extracts obtained by enzymatic disruption proved to be more promising in relation to its antioxidant activity.Key words: Microbial carotenoids, antioxidant properties, cell wall disruption
Decaying Dark Matter in the Supersymmetric Standard Model with Freeze-in and Seesaw mechanims
Inspired by the decaying dark matter (DM) which can explain cosmic ray
anomalies naturally, we consider the supersymmetric Standard Model with three
right-handed neutrinos (RHNs) and R-parity, and introduce a TeV-scale DM sector
with two fields \phi_{1,2} and a discrete symmetry. The DM sector only
interacts with the RHNs via a very heavy field exchange and then we can explain
the cosmic ray anomalies. With the second right-handed neutrino N_2 dominant
seesaw mechanism at the low scale around 10^4 GeV, we show that \phi_{1,2} can
obtain the vacuum expectation values around the TeV scale, and then the
lightest state from \phi_{1,2} is the decay DM with lifetime around \sim
10^{26}s. In particular, the DM very long lifetime is related to the tiny
neutrino masses, and the dominant DM decay channels to \mu and \tau are related
to the approximate \mu-\tau symmetry. Furthermore, the correct DM relic density
can be obtained via the freeze-in mechanism, the small-scale problem for power
spectrum can be solved due to the decays of the R-parity odd meta-stable states
in the DM sector, and the baryon asymmetry can be generated via the soft
leptogensis.Comment: 24 pages,3 figure
The Interplay Between GUT and Flavour Symmetries in a Pati-Salam x S4 Model
Both Grand Unified symmetries and discrete flavour symmetries are appealing
ways to describe apparent structures in the gauge and flavour sectors of the
Standard Model. Both symmetries put constraints on the high energy behaviour of
the theory. This can give rise to unexpected interplay when building models
that possess both symmetries. We investigate on the possibility to combine a
Pati-Salam model with the discrete flavour symmetry that gives rise to
quark-lepton complementarity. Under appropriate assumptions at the GUT scale,
the model reproduces fermion masses and mixings both in the quark and in the
lepton sectors. We show that in particular the Higgs sector and the running
Yukawa couplings are strongly affected by the combined constraints of the Grand
Unified and family symmetries. This in turn reduces the phenomenologically
viable parameter space, with high energy mass scales confined to a small region
and some parameters in the neutrino sector slightly unnatural. In the allowed
regions, we can reproduce the quark masses and the CKM matrix. In the lepton
sector, we reproduce the charged lepton masses, including bottom-tau
unification and the Georgi-Jarlskog relation as well as the two known angles of
the PMNS matrix. The neutrino mass spectrum can present a normal or an inverse
hierarchy, and only allowing the neutrino parameters to spread into a range of
values between and , with .
Finally, our model suggests that the reactor mixing angle is close to its
current experimental bound.Comment: 62 pages, 4 figures; references added, version accepted for
publication in JHE
Employment and sociodemographic characteristics: a study of increasing precarity in the health districts of Belo Horizonte, Brazil
<p>Abstract</p> <p>Background</p> <p>The fundamental importance of human resources for the development of health care systems is recognized the world over. Health districts, which constitute the middle level of the municipal health care system in the city of Belo Horizonte, Brazil, deal with demands from all parts of the system. This research seeks to provide the essential features required in order to understand the phenomenon of increase in precarity of employment in these health districts.</p> <p>Methods</p> <p>The legal and human resource management documents used by the Municipal Health Secretariat of the City of Belo Horizonte were adopted as the corpus for this research. In order to analyse the changes in employment (2002–2006), the data were collected from ArteRH, a computerized database dealing specifically with data related to human resources, which began operating in 2001. The workers were classified into permanent and non-permanent groups, and their contractual rights were described. Employment dynamics and changes were examined, concentrating on the incorporation of workers and on their social and employment rights during the period under study. The comparative data for the two groups obtained were presented in frequency distribution tables according to type of employment, sex, age group, level of education and wages from 2002 to 2006.</p> <p>Results</p> <p>There was a clear difference between the permanent worker and non-permanent worker groups as regards existing guaranteed employment rights and social security. The increase in the number of non-permanent workers in the workforce, the growing proportion of older workers among the permanently employed and the real wage reductions during the period from 2002 to 2006 are indicative of the process of growing precarity of employment in the group studied.</p> <p>Conclusion</p> <p>It is a plausible supposition that the demand for health reforms, along with the legal limits imposed on financial expenditure, gave rise to the new types of contract and the present employment situation in the health districts in Belo Horizonte.</p
The view of teachers on bullying and implications for nursing
Objetivo: Compreender o bullying escolar,
na perspectiva dos professores, e refletir
sobre as possíveis ações da área da saúde
em seu enfrentamento. Para tanto, tomaram-
se por base as diretrizes do Programa
Saúde na Escola, dos Ministérios da Saúde
e da Educação. Método: Estudo de caso
qualitativo, realizado com professores de
uma escola pública de Minas Gerais. Foram
utilizados grupos focais na coleta de dados
e o material empírico foi decodificado
a partir de técnica de análise temática de
conteúdo, resultando em uma categoria
analítica: concepções e experiências de
professores diante do bullying. Resultados:
Foram identificadas percepções pontuais
sobre o fenômeno e utilização de recursos
de intervenção pouco eficazes. No plano
interpretativo, problematizaram-se as contribuições
da saúde e da enfermagem no
redimensionamento das intervenções e no
processo de formação continuada dos professores.
Conclusão: Os resultados apontam
para a construção de práticas intersetoriais
para o enfrentamento do bullying.To understand school bullying from the perspective of teachers and reflect about the possible actions of the health area when coping with it. The guidelines of the School Health Program of the Ministries of Health and Education were used to reach that purpose. Method: A qualitative study carried out with teachers of a public school in Minas Gerais. Focus groups were used to collect data and the empirical material was decoded from thematic analysis of content, resulting in an analytical category: conceptions and experiences of teachers on bullying. Results: Specific perceptions about the phenomenon and the use of ineffective intervention resources were identified. In the interpretive plan were problematized the health and nursing contributions with resizing the interventions and the continuing training process of teachers. Conclusion: The results point to the construction of intersectoral practices forcoping with bullying.Objetivo: Comprender el bullying escolar
desde la perspectiva de los profesores,
y reflexionar sobre las posibles acciones
del área de salud en su enfrentamiento.
Tomando como base los lineamientos del
Programa de Salud Escolar, de los Ministerios
de Salud y de Educación. Método:
Estudio de caso cualitativo realizado con
los profesores de una escuela pública en
Minas Gerais. Para la recolección de datos
se utilizaron grupos focales y el material
empírico fue decodificado a partir de la
técnica de análisis temático de contenido,
dando lugar a una categoría analítica: concepciones
y experiencias de los profesores
sobre el acoso escolar. Resultados: Se identificaron
percepciones específicas sobre el
fenómeno y la utilización de recursos ineficaces
de intervención. En el plano interpretativo,
se problematizaron las contribuciones
de la salud y de la enfermería en el
redimensionamiento de las intervenciones
y en el proceso de formación continua de
los profesores. Conclusión: Los resultados
apuntan a la construcción de prácticas intersectoriales
para el enfrentamiento del
bullying.CIEC - Centro de Investigação em Estudos da Criança, UM (UI 317 da FCT
Cascade Textures and SUSY SO(10) GUT
We give texture analyses of cascade hierarchical mass matrices in
supersymmetric SO(10) grand unified theory. We embed cascade mass textures of
the standard model fermion with right-handed neutrinos into the theory, which
gives relations among the mass matrices of the fermions. The related
phenomenologies, such as the lepton flavor violating processes and
leptogenesis, are also investigated in addition to the PMNS mixing angles.Comment: 27 pages, 4 figures, comments and references added, final versio
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