320 research outputs found
Time-lapse 3-D measurements of a glucose biosensor in multicellular spheroids by light sheet fluorescence microscopy in commercial 96-well plates
Light sheet fluorescence microscopy has previously been demonstrated on a commercially available inverted fluorescence microscope frame using the method of oblique plane microscopy (OPM). In this paper, OPM is adapted to allow time-lapse 3-D imaging of 3-D biological cultures in commercially available glass-bottomed 96-well plates using a stage-scanning OPM approach (ssOPM). Time-lapse 3-D imaging of multicellular spheroids expressing a glucose Förster resonance energy transfer (FRET) biosensor is demonstrated in 16 fields of view with image acquisition at 10 minute intervals. As a proof-of-principle, the ssOPM system is also used to acquire a dose response curve with the concentration of glucose in the culture medium being varied across 42 wells of a 96-well plate with the whole acquisition taking 9 min. The 3-D image data enable the FRET ratio to be measured as a function of distance from the surface of the spheroid. Overall, the results demonstrate the capability of the OPM system to measure spatio-temporal changes in FRET ratio in 3-D in multicellular spheroids over time in a multi-well plate format
Risk-Informed design process of the IRIS reactor
Westinghouse is currently conducting the pre-application licensing of the International Reactor Innovative and
Secure (IRIS). The design philosophy of the IRIS has been based on the concept of Safety-by-DesignTM and within this
framework the PSA is being used as an integral part of the design process. The basis for the PSA contribution to the design
phase of the reactor is the close iteration between the PSA team and the design and safety analysis team. In this process the
design team is not only involved in the initial phase of providing system information to the PSA team, allowing in this way the
identification of the high risk scenarios, but it is also receiving feedback from the PSA team that suggests design modification
aimed at reaching risk-related goals.
During the first iteration of this process, the design modifications proposed by the PSA team allowed reducing the initial
estimate of Core Damage Frequency (CDF) due to internal events from 2E-6/ry to 2E-8/ry. Since the IRIS design is still in a
development phase, a number of assumptions have to be confirmed when the design is finalized.
Among key assumptions are the success criteria for both the accident sequences analyzed and the systems involved in the
mitigation strategies. The PSA team developed the initial accident sequence event trees according to the information from
the preliminary analysis and feasibility studies. A recent coupling between the RELAP and GOTHIC codes made possible the
actual simulation of all LOCA sequences identified in the first draft of the Event Trees. Working in close coordination, the
PSA and the safety analysis teams developed a matrix case of sequences not only with the purpose of testing the assumed
success criteria, but also with the perspective of identifying alternative sequences developed mainly by relaxing the extremely
conservative assumptions previously made.
The results of these simulations, bounded themselves with conservative assumptions on the Core Damage definition,
suggested two new versions of the LOCA Event Tree with two possible configurations of the Automatic Depressurization
System. The new CDF has been evaluated for both configurations and the design team has been provided with an additional
and risk-related perspective that will help choosing the design alternative to be implemented
O conceito de conflitos ambientais na revista de direito ambiental no ano de 2010
Em continuidade à pesquisa sobre conflitos ambientais, realizada no ano de 2010, busca-se verificar a visão de articulistas de uma revista especializada em direito ambiental dos conflitos atuais, categorizando seus conceitos e perspectivas. No presente estudo, ainda em andamento, foram selecionados 08 artigos publicados no ano de 2010 na Revista de Direito Ambiental da Editora Revista dos Tribunais, referência na área, detentora de avaliação B2 no sistema Qualis, pertencente ao acervo da Biblioteca Central do UniFOA. Está sendo realizado, a partir da leitura dos referidos artigos, a identificação do que consiste, em cada caso, na perspectiva do autor, o conflito ambiental. Estão sendo avaliados a conceituação de conflito, identificando o bem ambiental violado, os atores envolvidos e seus papéis. O objetivo foi o de identificar os conflitos ambientais abordados nos artigos publicados, categorizar conceitos de conflitos ambientais, relacionar os argumentos utilizados e estabelecer uma relação entre os conflitos e os fundamentos utilizados para a sua solução
International migration of unaccompanied minors: trends, health risks, and legal protection
The global population of unaccompanied minors—children and adolescents younger than 18 years who migrate without their legal guardians—is increasing. However, as data are not systematically collected in any region, if collected at all, little is known about this diverse group of young people. Compared with adult migrants, unaccompanied minors are at greater risk of harm to their health and integrity because they do not have the protection provided by a family, which can affect their short-term and long-term health. This Review summarises evidence regarding the international migration and health of unaccompanied minors. Unaccompanied minors are entitled to protection that should follow their best interests as a primary consideration; however, detention, sometimes under the guise of protection, is a widespread practice. If these minors are provided with appropriate forms of protection, including health and psychosocial care, they can thrive and have good long-term outcomes. Instead, hostile immigration practices persist, which are not in the best interests of the child
Conflitos ambientais a luz dos pressupostos procedimentais de democracia
Os conflitos ambientais, em especial na Região Sul-Fluminense, representam uma parcela significativa das questões de tensão entre sociedade, empresariado e Poder Público, gerando atritos na relação entre estes atores. A aplicação de técnicas de mediação, por meio do seu potencial racionalizador do debate, torna-se um instrumento teórico importante para a resolução dos conflitos ambientais. Isto porque, enquanto os ecossistemas sofrem alterações lentas e continuas devido às leis físicas, a história demonstra uma aceleração progressiva da evolução pela qual passa o homem, que, para satisfazer suas necessidades ilimitadas, disputa os bens da natureza, que são limitados, acentuando o desequilíbrio ecológico e, consequentemente, gerando conflitos na comunidade, pois se utilizam recursos pertencentes às gerações futuras. A criação de medidas alternativas como o desenvolvimento sustentável, cuja característica principal consiste na possível e desejável conciliação entre o desenvolvimento, a preservação do meio ambiente e a melhoria da qualidade de vida, seria uma forma de resolução do problema. O desenvolvimento sustentável é um processo de mudança no qual o uso de recursos, as políticas econômicas, a dinâmica populacional e as estruturas institucionais estão em harmonia e reforçam o potencial atual e futuro para o progresso humano. Apesar de reconhecer que as atividades econômicas devem caber à iniciativa privada, a busca do desenvolvimento sustentável exigirá, sempre que necessário, a interação dos atores envolvidos nos campos social, ambiental, econômico, judicial e de ordem pública, de modo a garantir democraticamente um mínimo de qualidade devida para todos. E tal objetivo será concretizado a partir da utilização da mediação como instrumento de resolução dos conflitos mencionados.
Generating and probing a two-photon Fock state with a single atom in a cavity
A two-photon Fock state is prepared in a cavity sustaining a "source mode "
and a "target mode", with a single circular Rydberg atom. In a third-order
Raman process, the atom emits a photon in the target while scattering one
photon from the source into the target. The final two-photon state is probed by
measuring by Ramsey interferometry the cavity light shifts induced by the
target field on the same atom. Extensions to other multi-photon processes and
to a new type of micromaser are briefly discussed
Band spectra of rectangular graph superlattices
We consider rectangular graph superlattices of sides l1, l2 with the
wavefunction coupling at the junctions either of the delta type, when they are
continuous and the sum of their derivatives is proportional to the common value
at the junction with a coupling constant alpha, or the "delta-prime-S" type
with the roles of functions and derivatives reversed; the latter corresponds to
the situations where the junctions are realized by complicated geometric
scatterers. We show that the band spectra have a hidden fractal structure with
respect to the ratio theta := l1/l2. If the latter is an irrational badly
approximable by rationals, delta lattices have no gaps in the weak-coupling
case. We show that there is a quantization for the asymptotic critical values
of alpha at which new gap series open, and explain it in terms of
number-theoretic properties of theta. We also show how the irregularity is
manifested in terms of Fermi-surface dependence on energy, and possible
localization properties under influence of an external electric field.
KEYWORDS: Schroedinger operators, graphs, band spectra, fractals,
quasiperiodic systems, number-theoretic properties, contact interactions, delta
coupling, delta-prime coupling.Comment: 16 pages, LaTe
World Press Photo 2012: the discursive construction of the Arab Spring
O presente artigo pretende analisar a forma como o fenómeno da Primavera Árabe foi retratado nas fotografias vencedoras do concurso World Press Photo em 2012.
As fotografias jornalísticas, embora se apresentem como índices do real, condicionam frequentemente a percepção dos indivíduos e influenciam as suas práticas sociais.
Também as fotografias vencedoras do World Press Photo, um dos concursos mais prestigiados de fotojornalismo, em 2012 não fogem ao construtivismo discursivo que molda a representação e a percepção dos acontecimentos.
A partir da análise crítica do discurso, nomeadamente dos instrumentos teóricos da semiótica barthesiana e da semiótica social de Gunther Kress e Theo van Leeuwen, procurámos interpretar as 38 fotografias vencedoras do World Press Photo 2012, a fim de reflectirmos sobre o modo como contribuíram para a compreensão da Revolta Árabe e como despertaram o nosso interesse e a nossa imaginação para o desenrolar do conflito.ABSTRACT:This article aims to analyze how the Arab Spring phenomenon was represented in the award-winning photographs of the World Press Photo contest in 2012.
Although news photographs are usually seen as indexes of the real, they often limit the perception of individuals and influence their social practices.
Also the winning photographs in 2012 of the World Press Photo, one of the most prestigious photojournalism contests, do not escape the discursive constructivism that shapes the representation and perception of events.
Drawing from critical discourse analysis, namely from the theoretical tools of barthesian semiotics and Gunther Kress’s and Theo van Leeuwen’s social semiotics, we sought to interpret the 38 award-winning photographs of the World Press Photo contest in 2012, in order to reflect on the way they have contributed to our understanding of the Arab Revolt and aroused our interest and imagination to the unfolding of the conflict.info:eu-repo/semantics/publishedVersio
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