768 research outputs found
Extension of Bethe's diffraction model to conical Geometry: application to near field optics
The generality of the Bethe's two dipole model for light diffraction through
a subwavelength aperture in a conducting plane is studied in the radiation zone
for coated conical fiber tips as those used in near field scanning optical
microscopy. In order to describe the angular radiated power of the tip
theoretically, we present a simple, analytical model for small apertures
(radius < 40 nm) based on a multipole expansion. Our model is able to reproduce
the available experimental results. It proves relatively insensitive to cone
angle and aperture radius and contains, as a first approximation, the empirical
two-dipole model proposed earlier
Communication and Low Mood (CALM): a randomized controlled trial of behavioural therapy for stroke patients with aphasia
Objective:
The aim was to evaluate behavioural therapy as a treatment for low mood in people with aphasia.
Design:
A randomized controlled trial comparing behavioural therapy plus usual care with a usual care control. Potential participants with aphasia after stroke were screened for the presence of low mood. Those who met the criteria and gave consent were randomly allocated.
Setting:
Participants were recruited from hospital wards, community rehabilitation, speech and language therapy services and stroke groups.
Subjects:
Of 511 people with aphasia identified, 105 had low mood and were recruited.
Interventions:
Behavioural therapy was offered for up to three months. Outcomes were assessed three and six months after random allocation.
Main measures:
Stroke Aphasic Depression Questionnaire, Visual Analog Mood Scales ‘sad’ item, and Visual Analogue Self-Esteem Scale.
Results:
Participants were aged 29 to 94 years (mean 67.0, SD 13.5) and 66 (63%) were men. Regression analysis showed that at three months, when baseline values and communication impairment were controlled for, group allocation was a significant predictor of the Stroke Aphasic Depression Questionnaire (P < 0.05), visual analogue ‘sad’ (P = 0.03), and Visual Analogue Self-Esteem Scale (P < 0.01). At six months, group alone was a significant predictor of the Stroke Aphasic Depression Questionnaire (P < 0.05), and remained significant when baseline values were controlled for (P = 0.02). Mean Stroke Aphasic Depression Questionnaire 10-item hospital version scores decreased from baseline to six months by six points in the intervention group as compared with an increase of 1.9 points in the control group.
Conclusions:
Behavioural therapy seemed to improve the mood of people with aphasia
Doping-dependent evolution of low-energy excitations and quantum phase transitions within effective model for High-Tc copper oxides
In this paper a mean-field theory for the spin-liquid paramagnetic
non-superconducting phase of the p- and n-type High- cuprates is
developed. This theory applied to the effective model with the
{\it ab initio} calculated parameters and with the three-site correlated
hoppings. The static spin-spin and kinematic correlation functions beyond
Hubbard-I approximation are calculated self-consistently. The evolution of the
Fermi surface and band dispersion is obtained for the wide range of doping
concentrations . For p-type systems the three different types of behavior
are found and the transitions between these types are accompanied by the
changes in the Fermi surface topology. Thus a quantum phase transitions take
place at and at . Due to the different Fermi surface topology
we found for n-type cuprates only one quantum critical concentration, .
The calculated doping dependence of the nodal Fermi velocity and the effective
mass are in good agreement with the experimental data.Comment: 8 page
Probing for Invisible Higgs Decays with Global Fits
We demonstrate by performing a global fit on Higgs signal strength data that
large invisible branching ratios Br_{inv} for a Standard Model (SM) Higgs
particle are currently consistent with the experimental hints of a scalar
resonance at the mass scale m_h ~ 124 GeV. For this mass scale, we find
Br_{inv} < 0.64 (95 % CL) from a global fit to individual channel signal
strengths supplied by ATLAS, CMS and the Tevatron collaborations. Novel tests
that can be used to improve the prospects of experimentally discovering the
existence of a Br_{inv} with future data are proposed. These tests are based on
the combination of all visible channel Higgs signal strengths, and allow us to
examine the required reduction in experimental and theoretical errors in this
data that would allow a more significantly bounded invisible branching ratio to
be experimentally supported. We examine in some detail how our conclusions and
method are affected when a scalar resonance at this mass scale has couplings
deviating from the SM ones.Comment: 32pp, 15 figures v2: JHEP version, ref added & comment added after
Eq.
Anomalous Couplings in Double Higgs Production
The process of gluon-initiated double Higgs production is sensitive to
non-linear interactions of the Higgs boson. In the context of the Standard
Model, studies of this process focused on the extraction of the Higgs trilinear
coupling. In a general parametrization of New Physics effects, however, an even
more interesting interaction that can be tested through this channel is the
(ttbar hh) coupling. This interaction vanishes in the Standard Model and is a
genuine signature of theories in which the Higgs boson emerges from a
strongly-interacting sector. In this paper we perform a model-independent
estimate of the LHC potential to detect anomalous Higgs couplings in
gluon-fusion double Higgs production. We find that while the sensitivity to the
trilinear is poor, the perspectives of measuring the new (ttbar hh) coupling
are rather promising.Comment: 22 pages, 9 figures. v2: plots of Figs.8 and 9 redone to include
experimental uncertainty on the Higgs couplings, references adde
Business development in renewable energy
This paper discusses how to foster development of renewable energy business. Factors that impede or enhance renewable energy in the EU 27 member states in the period 1998–2008 are analyzed. Nine factors are considered: population density, production output and energy sector output to indicate market conditions, public total expenditures, subsidies and environmental protection expenditures to indicate institutional conditions, R&D, share of students in population and venture capital to indicate firm’s resources. Scarce space for business development and vested energy interests are the main impediments. R&D and venture capital are main drivers. The US and EU support for R&D and venture capital in renewable energy are compared. The US support is larger and mainly based on R&D grants. It has generated large, innovative enterprises. The EU support is mainly based on price guarantees for renewable energy delivery to grid. It has generated many enterprises. Building capabilities through stakeholders’ networks in early phase of business development and clusters in the later phase is recommended
Theory of imaging a photonic crystal with transmission near-field optical microscopy
While near-field scanning optical microscopy (NSOM) can provide optical
images with resolution much better than the diffraction limit, analysis and
interpretation of these images is often difficult. We present a theory of
imaging with transmission NSOM that includes the effects of tip field,
tip/sample coupling, light propagation through the sample and light collection.
We apply this theory to analyze experimental NSOM images of a nanochannel glass
(NCG) array obtained in transmission mode. The NCG is a triangular array of
dielectric rods in a dielectric glass matrix with a two-dimensional photonic
band structure. We determine the modes for the NCG photonic crystal and
simulate the observed data. The calculations show large contrast at low
numerical aperture (NA) of the collection optics and detailed structure at high
NA consistent with the observed images. We present calculations as a function
of NA to identify how the NCG photonic modes contribute to and determine the
spatial structure in these images. Calculations are presented as a function of
tip/sample position, sample index contrast and geometry, and aperture size to
identify the factors that determine image formation with transmission NSOM in
this experiment.Comment: 28 pages of ReVTex, 14 ps figures, submitted to Phys. Rev.
Estrogen-dependent dynamic profile of eNOS-DNA associations in prostate cancer
In previous work we have documented the nuclear translocation of endothelial NOS (eNOS) and its participation in combinatorial complexes with Estrogen Receptor Beta (ERβ) and Hypoxia Inducible Factors (HIFs) that determine localized chromatin remodeling in response to estrogen (E2) and hypoxia stimuli, resulting in transcriptional regulation of genes associated with adverse prognosis in prostate cancer (PCa). To explore the role of nuclear eNOS in the acquisition of aggressive phenotype in PCa, we performed ChIP-Sequencing on chromatin-associated eNOS from cells from a primary tumor with poor outcome and from metastatic LNCaP cells. We found that: 1. the eNOS-bound regions (peaks) are widely distributed across the genome encompassing multiple transcription factors binding sites, including Estrogen Response Elements. 2. E2 increased the number of peaks, indicating hormone-dependent eNOS re-localization. 3. Peak distribution was similar with/without E2 with ≈ 55% of them in extragenic DNA regions and an intriguing involvement of the 5′ domain of several miRs deregulated in PCa. Numerous potentially novel eNOS-targeted genes have been identified suggesting that eNOS participates in the regulation of large gene sets. The parallel finding of downregulation of a cluster of miRs, including miR-34a, in PCa cells associated with poor outcome led us to unveil a molecular link between eNOS and SIRT1, an epigenetic regulator of aging and tumorigenicity, negatively regulated by miR-34a and in turn activating eNOS. E2 potentiates miR-34a downregulation thus enhancing SIRT1 expression, depicting a novel eNOS/SIRT1 interplay fine-tuned by E2-activated ER signaling, and suggesting that eNOS may play an important role in aggressive PCa
How do we get there? Effects of cognitive aging on route memory
© 2017 The Author(s) Research into the effects of cognitive aging on route navigation usually focuses on differences in learning performance. In contrast, we investigated age-related differences in route knowledge after successful route learning. One young and two groups of older adults categorized using different cut-off scores on the Montreal Cognitive Assessment (MoCA), were trained until they could correctly recall short routes. During the test phase, they were asked to recall the sequence in which landmarks were encountered (Landmark Sequence Task), the sequence of turns (Direction Sequence Task), the direction of turn at each landmark (Landmark Direction Task), and to identify the learned routes from a map perspective (Perspective Taking Task). Comparing the young participant group with the older group that scored high on the MoCA, we found effects of typical aging in learning performance and in the Direction Sequence Task. Comparing the two older groups, we found effects of early signs of atypical aging in the Landmark Direction and the Perspective Taking Tasks. We found no differences between groups in the Landmark Sequence Task. Given that participants were able to recall routes after training, these results suggest that typical and early signs of atypical aging result in differential memory deficits for aspects of route knowledge
Medical error in the portuguese press: when patients are part of the news
Esta investigação aborda a qualidade da produção noticiosa sobre o erro médico, como um fator essencial na construção do conhecimento público sobre o tema, com o objetivo de compreender que características definem tal produção e até que ponto poderão ser explicadas pela periodicidade e orientação editorial dos jornais; que conceito de erro médico é veiculado pela produção noticiosa sobre o tema; e quais são os protagonistas no discurso jornalístico sobre o erro médico. Foram analisadas as edições de três jornais portugueses, de 2008 a 2011, resultando num corpus de 266 (4,2%) artigos, que foram classificados de acordo com as seguintes variáveis: as fontes de informação citadas (o seu estatuto e especialidade, no caso dos médicos); os temas que são tratados; as características de enquadramento da informação publicada (tom, género jornalístico; e a presença e número de fontes de informação). Pela análise de conteúdo quantitativa, apurou-se que esse tema está em crescimento, essencialmente com notícias de tom negativo e fontes de informação habitualmente identificadas. Não há evidência para afirmar que a periodicidade e a orientação editorial expliquem as variações dessas características, a não ser relativamente ao número de fontes citadas. Vigoram as notícias centradas nos resultados dos erros (mortes ou lesões), provocados por "erros de omissão" e por "erros de comissão", envolvendo uma diversidade de protagonistas: são, tal como acontece na informação sobre saúde em geral, fontes oficiais e especializadas do campo da saúde. Destacam-se os médicos e os juristas e é dado relevo aos pacientes.This research addresses the quality of news production on medical error, as an essential factor in building public knowledge on the subject, in order to understand which characteristics define the news production of medical error and to what extent can they be explained by the periodicity and editorial orientation of the newspaper; which concept of medical error is transmitted by the news production on the subject; and who are the main actors in the journalistic discourse about medical error. The editions of three Portuguese newspapers were analyzed, from 2008 to 2011, resulting in a corpus of 266 (4.2%) articles, which were classified according to the following variables: the sources of information quoted (their status and specialty, in the case of doctors); the issues covered; and characteristic framework of the published information (tone, journalistic style, and the presence and number of information sources). Through quantitative content analysis, it was found that this topic is growing, essentially with negative news and information sources usually being identified. There is no evidence to support that periodicity and editorial orientation explain the variations in these characteristics, except for the number of cited sources. News focused on the results of errors (death or injury), caused by "errors of omission" and "commission errors", prevail, involving a variety of actors: they are, such as it happens in health information, in general, official sources and experts in health. Doctors and lawyers stand out, and special attention is given to patients
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