402 research outputs found
MAPK phosphorylation of connexin 43 promotes binding of cyclin E and smooth muscle cell proliferation
<p>Rationale: Dedifferentiation of vascular smooth muscle cells (VSMC) leading to a proliferative cell phenotype significantly contributes to the development of atherosclerosis. Mitogen-activated protein kinase (MAPK) phosphorylation of proteins including connexin 43 (Cx43) has been associated with VSMC proliferation in atherosclerosis.</p>
<p>Objective: To investigate whether MAPK phosphorylation of Cx43 is directly involved in VSMC proliferation.</p>
<p>Methods and Results: We show in vivo that MAPK-phosphorylated Cx43 forms complexes with the cell cycle control proteins cyclin E and cyclin-dependent kinase 2 (CDK2) in carotids of apolipoprotein-E receptor null (ApoEâ/â) mice and in C57Bl/6 mice treated with platelet-derived growth factorâBB (PDGF). We tested the involvement of Cx43 MAPK phosphorylation in vitro using constructs for full-length Cx43 (Cx43) or the Cx43 C-terminus (Cx43CT) and produced null phosphorylation Ser>Ala (Cx43MK4A/Cx43CTMK4A) and phospho-mimetic Ser>Asp (Cx43MK4D/Cx43CTMK4D) mutations. Coimmunoprecipitation studies in primary VSMC isolated from Cx43 wild-type (Cx43+/+) and Cx43 null (Cx43â/â) mice and analytic size exclusion studies of purified proteins identify that interactions between cyclin E and Cx43 requires Cx43 MAPK phosphorylation. We further demonstrate that Cx43 MAPK phosphorylation is required for PDGF-mediated VSMC proliferation. Finally, using a novel knock-in mouse containing Cx43-MK4A mutation, we show in vivo that interactions between Cx43 and cyclin E are lost and VSMC proliferation does not occur after treatment of carotids with PDGF and that neointima formation is significantly reduced in carotids after injury.</p>
<p>Conclusions: We identify MAPK-phosphorylated Cx43 as a novel interacting partner of cyclin E in VSMC and show that this interaction is critical for VSMC proliferation. This novel interaction may be important in the development of atherosclerotic lesions.</p>
Bi2Fe4O9 thin films as novel visible-light-active photoanodes for solar water splitting
We report the chemical solution deposition (CSD) of a phase-pure Bi2Fe4O9 thin film for use as a photoanode in photoelectrochemical (PEC) water splitting. The energy levels of Bi2Fe4O9 films have been measured and n-type characteristics have been confirmed. With band gaps determined as 2.05 eV (indirect) and 2.80 eV (direct) and valence and conduction bands straddling the water oxidation and reduction potentials, this material is highly promising as a photocatalyst for solar water splitting. The photocurrent of a planar photoanode reached 0.1 mA cmâ2 at 1.23 VNHE under AM1.5G illumination. The addition of H2O2 as a hole scavenger increased the photocurrent to 0.25 mA cmâ2, indicating hole injection is one limiting factor to the performance. The performance was enhanced by nearly 5-fold when the Bi2Fe4O9 photoanode is coupled to a CoâPi surface co-catalyst. The photoanode also shows excellent stability with no change in photocurrent over three hours of continuous illumination. These results indicate that this material represents a promising addition to the growing selection of low-cost, stable photocatalysts for use in solar water splitting
Thermodynamics of non-local materials: extra fluxes and internal powers
The most usual formulation of the Laws of Thermodynamics turns out to be
suitable for local or simple materials, while for non-local systems there are
two different ways: either modify this usual formulation by introducing
suitable extra fluxes or express the Laws of Thermodynamics in terms of
internal powers directly, as we propose in this paper. The first choice is
subject to the criticism that the vector fluxes must be introduced a posteriori
in order to obtain the compatibility with the Laws of Thermodynamics. On the
contrary, the formulation in terms of internal powers is more general, because
it is a priori defined on the basis of the constitutive equations. Besides it
allows to highlight, without ambiguity, the contribution of the internal powers
in the variation of the thermodynamic potentials. Finally, in this paper, we
consider some examples of non-local materials and derive the proper expressions
of their internal powers from the power balance laws.Comment: 16 pages, in press on Continuum Mechanics and Thermodynamic
Qualitative Properties of Magnetic Fields in Scalar Field Cosmology
We study the qualitative properties of the class of spatially homogeneous
Bianchi VI_o cosmological models containing a perfect fluid with a linear
equation of state, a scalar field with an exponential potential and a uniform
cosmic magnetic field, using dynamical systems techniques. We find that all
models evolve away from an expanding massless scalar field model in which the
matter and the magnetic field are negligible dynamically. We also find that for
a particular range of parameter values the models evolve towards the usual
power-law inflationary model (with no magnetic field) and, furthermore, we
conclude that inflation is not fundamentally affected by the presence of a
uniform primordial magnetic field. We investigate the physical properties of
the Bianchi I magnetic field models in some detail.Comment: 12 pages, 2 figures in REVTeX format. to appear in Phys. Rev.
The Simple View of Reading Made Complex by Morphological Decoding Fluency in Bilingual Fourth-Grade Readers of English
This is the author accepted manuscript. The final version is available from Wiley via the DOI in this recordThis study examined the complexity of the Simple View of Reading focusing on morphological
decoding fluency in fourth-grade readers of English in Singapore. The participants were three
groups of students who all learned to become bilingual and biliterate in the English language
(EL) and their respective ethnic language in school but differed in the home language they used.
The first group was ethnic Chinese students who used English as the dominant home language
(Chinese EL1); the other two groups were ethnic Chinese and Malay students whose dominant
home language was not English but Chinese (Chinese EL2) and Malay (Malay EL2),
respectively. The measures included pseudo word decoding (phonemic decoding), timed
decoding of derivational words (morphological decoding fluency), oral vocabulary, and passage
comprehension. Path analysis showed that oral vocabulary significantly predicted reading
comprehension across all three groups; yet a significant effect of morphological decoding
fluency surfaced in the Chinese EL1 and Malay EL2 groups but not the Chinese EL2 group.
Multi-group path analysis and commonality analysis further confirmed that morphological
decoding played a larger role in the in the Chinese EL1 and Malay EL2 groups. These findings
are discussed in light of the joint influence of target language experience and cross-linguistic
influence on second language or bilingual reading development.Office of Education Research, National Institute of Education, Nanyang Technological Universit
Translation to practice: a randomised controlled study of an evidenced based booklet targeted at breast care nurses in the United Kingdom
BACKGROUND: In the United Kingdom (UK), it was documented that a problem of knowledge transfer existed within the speciality of breast-cancer care, thus depriving patients of receiving optimal care. Despite increasingly robust research evidence indicating recommendation of whole body exercise for people affected by breast cancer, commensurate changes to practice were not noted amongst breast-care nurses (BCNs).
AIM: To evaluate the effect of a targeted booklet, Exercise and Breast Cancer: A Booklet for Breast-Care Nurses, on changes in knowledge, reported practice, and attitudes of BCNs in the UK.
METHOD: A prospective, experimental approach was used for designing a pre- and post-test randomised controlled study. Comparisons of knowledge, reported practice, and attitudes based on responses to a questionnaire were made at two time-points in two groups of BCNs (control and experimental). The unit of randomisation and analysis was hospital clusters of BCNs. The sample comprised 92 nurses from 62 hospitals. Analysis consisted of descriptive statistics and clustered regression techniques: clustered logistic regression for knowledge items, clustered linear regression for knowledge scores, ologit for attitude and reported practice items, and clustered multiple regression for paired and multiple variable analysis.
RESULTS: A statistically significant increase in knowledge and changes in reported practice and attitudes were found. Robust variables affecting knowledge acquisition were: promotion of health, promotion of exercise, and understanding how exercise can reduce cancer-related fatigue.
DISCUSSION: The study has shown that evidence-based printed material, such as an information booklet, can be used as an effective research dissemination method when developed for needs, values, and context of a target audience.
CONCLUSIONS: This practical approach to research dissemination could be replicated and applied to other groups of nurses.</p
Australia Day, flags on cars and Australian nationalism
This article reports the results of research into the recent popular phenomenon of flying Australian flags on oneâs car for Australia Day. A survey was undertaken in Western Australia in 2011 to ascertain who flies the flag and why. Results indicate the phenomenon was widespread, with a quarter of those surveyed displaying car-flags. A clear relationship between car-flag-flying and exclusionary nationalism is demonstrated. Car-flag-flyers rate more highly on measures of patriotism and nationalism, and feel more negative towards Muslims and asylum seekers, and more positive about the White Australia Policy. They are also significantly more likely to feel their culture and values are in danger, and have a nativist vision of Australian identity. While both groups are positive about Australiaâs diversity, car-flag-flyers are more likely to feel that migrants should assimilate. The results support other literature that suggests that in some contexts the Australian flag has come to be associated with exclusionary nationalism
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