2,799 research outputs found
Inhibition of tumor necrosis factor 뱉stimulated monocyte adhesion to human aortic endothelial cells by AMP-activated protein kinase
<b>Objective</b>â Proatherosclerotic adhesion of leukocytes to the endothelium is attenuated by NO. As AMP-activated protein kinase (AMPK) regulates endothelial NO synthesis, we investigated the modulation of adhesion to cultured human aortic endothelial cells (HAECs) by AMPK.
<b>Methods and Results</b>â HAECs incubated with the AMPK activator, AICAR, or expressing constitutively active AMPK demonstrated reduced TNF α-stimulated adhesion of promonocytic U-937 cells. Rapid inhibition of TNF α-stimulated U-937 cell adhesion by AICAR was NO-dependent, associated with unaltered cell surface adhesion molecule expression, and reduced MCP-1 secretion by HAECs. In contrast, inhibition of TNF α-stimulated U-937 cell adhesion by prolonged AMPK activation was NO-independent and associated with reduced cell surface adhesion molecule expression.
<b>Conclusions</b>â AMPK activation in HAECs inhibits TNF α-stimulated leukocyte adhesion by a rapid NO-dependent mechanism associated with reduced MCP-1 secretion and a late NO-independent mechanism whereby adhesion molecule expression, in particular E-selectin, is suppressed.
We investigated the functional effects of AMPK activation in cultured human endothelial cells. Stimulation of AMPK inhibited TNF α-stimulated monocyte adhesion by two distinct mechanisms: a rapid NO-dependent mechanism associated with a reduction in chemokine release and a late NO-independent mechanism whereby adhesion molecule expression is suppressed
Bosonic molecules in a lattice: unusual fluid phase from multichannel interactions
We show that multichannel interactions significantly alter the phase diagram
of ultracold bosonic molecules in an optical lattice. Most prominently, an
unusual fluid region intervenes between the conventional superfluid and the
Mott insulator. In it, number fluctuations remain but phase coherence is
suppressed by a significant factor. This factor can be made arbitrarily large,
at least in a two-site configuration. We calculate the phase diagram using
complementary methods, including Gutzwiller mean-field and density matrix
renormalization group (DMRG) calculations. Although we focus on bosonic
molecules without dipolar interactions, we expect multichannel interactions to
remain important for dipolar interacting and fermionic molecules.Comment: 6 pages incl. refs, 4 figure
Increasing Access to the James River Park System: A Community Roadmap with the Blackwell, Oak Grove, and Bellemeade Neighborhoods
Natural Parks like the James River Park System offer a host of benefits. They improve our mental health, make us better environmental stewards, Improve socialization, and make a healthier population by lowering the rates of asthma, obesity and hypertension. These public health outcomes disproportionately impacts minority communities in the City of Richmond, a population that visits the James River Park System at a lower rate than white communities do. This plan identifies the barriers preventing access for minority communities and gives recommendations to improve access in the City of Richmond
You Can Change the World With a Haircutâ: Evaluating the Feasibility of a Barber-led Intervention for Men of Black and Ethnic Minority Heritage to Manage High Blood Pressure
Background:
People of Black, Asian and minority ethnic (BAME) heritage have a higher-than-average incidence of, and mortality from hypertension and stroke. Therefore, it is important to identify new settings for engaging people at risk of high blood pressure (BP).
Aim:
This feasibility study aimed to evaluate if barbers in a London borough can support and educate men of BAME heritage to manage their BP. Following UK Medical Research Council guidance, the RE-AIM (reach, effectiveness, adoption, implementation, maintenance) framework was used to guide study objectives and feasibility outcomes.
Methods:
We collaborated with 8 barbers who were part of an existing BAME barber network. Barbers were trained online (1.5âh) and face-to-face (3âh) to provide BP healthcare advice and take customers BP readings. Qualitative field notes were collected to assess how best to recruit and train barbers, and to understand how to maintain motivation and retention of barbers. BP readings were recorded between June 2021 and March 2022.
Results:
Both online and face-to-face training were effective, however, greater focus on how to start conversations about BP with clients was needed. We found that motivation, incentivization and regular contact with barbers were important for recruitment, retention, and sustained BP measurement. Obtaining BP readings was challenging due to client concerns about recording their data and the impracticalities of recording results. We captured 236âBP recordings, of which 39 (16.53%) were over 140/90âmmHg; of these, 5 were over 180/100âmmHg.
Conclusion:
The combined data showed that educating barbers to take BP readings and deliver healthcare advice about BP is a viable intervention for rollout in a large-scale study. It has demonstrated the need to identify strategies to motivate barbers for sustained recruitment and retention, as well as further efforts to build trust among customers for long-term BP surveillance
Spectral line shape of resonant four-wave mixing induced by broad-bandwidth lasers
We present a theoretical and experimental study of the line shape of resonant four-wave mixing induced by broad-bandwidth laser radiation that revises the theory of Meacher, Smith, Ewart, and Cooper (MSEC) [Phys. Rev. A 46, 2718 (1992)]. We adopt the same method as MSEC but correct for an invalid integral used to average over the distribution of atomic velocities. The revised theory predicts a Voigt line shape composed of a homogeneous, Lorentzian component, defined by the collisional rate Î, and an inhomogeneous, Doppler component, which is a squared Gaussian. The width of the inhomogeneous component is reduced by a factor of â2 compared to the simple Doppler width predicted by MSEC. In the limit of dominant Doppler broadening, the width of the homogeneous component is predicted to be 4Î, whereas in the limit of dominant homogeneous broadening, the predicted width is 2Î. An experimental measurement is reported of the line shape of the four-wave-mixing signal using a broad-bandwidth, "modeless", laser resonant with the Q1 (6) line of the A2 ÎŁ - X2 Î (0,0) system of the hydroxyl radical. The measured widths of the Voigt components were found to be consistent with the predictions of the revised theory
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Sustainable construction: exploring the capabilities of Nigerian construction firms
As the built environment accounts for much of the world's emissions, resource consumption and waste, concerns remain as to how sustainable the sector is. Understanding how such concerns can be better managed is complex, with a range of competing agendas and institutional forces at play. This is especially the case in Nigeria where there are often differing priorities, weak regulations and institutions to deal with this challenge. Construction firms are in competition with each other in a market that is growing in size and sophistication yearly. The business case for sustainability has been argued severally in literature. However, the capability of construction firms with respect to sustainability in Nigeria has not been studied. This paper presents the preliminary findings of an exploratory multi-case study carried out to understand the firm's views on sustainability as a source of competitive advantage. A international firm and a lower medium-sized indigenous firm were selected for this purpose. Qualitative interviews were conducted with top-level management of both firms, with key themes from the sustainable construction and dynamic capabilities literature informing the case study protocol. The interviews were transcribed and analysed with the use of NVivo software. The findings suggest that the multinational firm is better grounded in sustainability knowledge. Although the level of awareness and demand for sustainable construction is generally very poor, few international clients are beginning to stimulate interest in sustainable buildings. This has triggered both firms to build their capabilities in that regard, albeit in an unhurried manner. Both firms agree on the potentials of market-driven sustainability in the long term. Nonetheless, more drastic actions are required to accelerate the sustainable construction agenda in Nigeria
The mineralogy and chemistry of the anorogenic Tertiary silicic volcanics of S.E. Queensland and N.E. New South Wales, Australia
Mineralogy and chemistry are used to infer petrogenesis, which is discussed in detail. -K.A.R
Non-thermal particle acceleration and power-law tails via relaxation to universal Lynden-Bell equilibria
Collisionless and weakly collisional plasmas often exhibit non-thermal
quasi-equilibria. Among these quasi-equilibria, distributions with power-law
tails are ubiquitous. It is shown that the statistical-mechanical approach
originally suggested by Lynden-Bell (1967) can easily recover such power-law
tails. Moreover, we show that, despite the apparent diversity of Lynden-Bell
equilibria, a generic form of the equilibrium distribution at high energies is
a `hard' power-law tail , where is the
particle energy. The shape of the `core' of the distribution, located at low
energies, retains some dependence on the initial condition but it is the tail
(or `halo') that contains most of the energy. Thus, a degree of universality
exists in collisionless plasmas.Comment: 33 pages, 5 figure
Modelos de Valor Agregado da EficĂĄcia Docente
Recent policy interest in tying student learning to teacher evaluation has led to growing use of value-added methods for assessing student learning gains linked to individual teachers. VAM analyses rely on complex assumptions about the roles of schools, multiple teachers, student aptitudes and efforts, homes and families in producing measured student learning gains. This article reports on analyses that examine the stability of high school teacher effectiveness rankings across differing conditions. We find that judgments of teacher effectiveness for a given teacher can vary substantially across statistical models, classes taught, and years. Furthermore, student characteristics can impact teacher rankings, sometimes dramatically, even when such characteristics have been previously controlled statistically in the value-added model. A teacher who teaches less advantaged students in a given course or year typically receives lower effectiveness ratings than the same teacher teaching more advantaged students in a different course or year. Models that fail to take student demographics into account further disadvantage teachers serving large numbers of low-income, limited English proficient, or lower-tracked students. We examine a number of potential reasons for these findings, and we conclude that caution should be exercised in using student achievement gains and value-added methods to assess teachers effectiveness, especially when the stakes are high.El reciente inters para relacionar los resultados de los aprendizajes de los estudiantes con las evaluaciones docentes ha provocado un uso creciente de Mtodos de Valor Aadido (MVA) para evaluar incrementos en los aprendizajes de los alumnos. Los anlisis MVA se basan en hiptesis complejas acerca del papel que desempean las escuelas, los profesores, las aptitudes de los estudiantes, sus esfuerzos, sus hogares y familias en la produccin de incrementos medibles de aprendizaje estudiantil . Este artculo discute los anlisis que examinan la estabilidad de las clasificaciones de eficacia de profesores de escuelas secundarias a travs de diferentes condiciones. Encontramos que valoraciones de la efectividad docente de un profesor/a pueden variar substancialmente a travs de los distintos modelos estadsticos, las clases enseadas y los aos de experiencia. Adems, las caractersticas de los estudiantes pueden impactar drsticamente las clasificaciones de los profesores, an cuando tales caractersticas hayan sido previamente controladas estadsticamente en un MVA. Los profesores que ensean a los estudiantes menos aventajados en un curso o ao determinado reciben clasificaciones de eficacia ms bajas que cuando un mismo profesor est enseando a los estudiantes ms aventajados en otro curso o ao. Los modelos que no toman en cuenta las caractersticas demogrficas de los estudiantes perjudican adicionalmente a los profesores que sirven a un gran nmero de estudiantes de bajos ingresos, con conocimientos limitados del idioma ingls o que estn en cursos de menor rendimiento acadmico. Examinamos un gran nmero de posibles razones para explicar estos resultados, entre ellas la naturaleza especfica de las medidas de las evaluaciones y los mtodos estadsticos utilizados y concluimos que se debe tener precaucin al hacer inferencias sobre la efectividad de profesores individuales basadas en modelos de Valor Aadido especialmente para determinar resultados que puedan tener consecuencias severas (como promocin de un ciclo para otro).O recente interesse poltico de relacionar resultados da aprendizagem dos alunos com as avaliaes de professores ocasionou uma crescente utilizao de Mtodos de Valor Agregado (MVA) para avaliar ganhos na aprendizagem dos alunos. Anlises MVA so baseadas em hipteses complexas sobre o papel das escolas, dos variados professores, das competncias e empenho dos alunos e do ambiente familiar na produo de aumentos mensurveis da aprendizagem dos alunos. Este artigo discute trabalhos que examinam a estabilidade das classificaes dos professores de ensino mdio em condies diferentes. Descobrimos que as avaliaes de eficcia do ensino de um professor podem variar consideravelmente a partir dos diferentes modelos estatsticos, das aulas ministradas e dos anos de experincia. Alm disso, caractersticas dos estudantes podem modificar drasticamente a classificao dos professores, mesmo que tais caractersticas tenham sido controladas estatisticamente nos MVA. Professores que ensinam alunos mais desfavorecidos em um determinado curso ou srie recebem avaliaes de desempenho inferiores do que o mesmo professor ensinando alunos mais favorecidos em outro curso ou srie. Modelos que no levam em conta as caractersticas demogrficas dos estudantes podem prejudicar professores que atendem um grande nmero de alunos de baixa renda, com habilidades limitadas em ingls ou que esto em cursos considerados fracos. Examinamos um grande nmero de possveis razes para estes resultados, incluindo a natureza especfica das medidas de avaliao e os mtodos estatsticos utilizados. Conclumos que necessrio muito cuidado ao se fazer inferncias sobre a eficcia dos professores com base em Modelos de Valor Agregado (MVA), especialmente para determinar resultados que podem ter consequncias graves (tais como a promoo de um ciclo para outro)
Collisionless relaxation of a Lynden-Bell plasma
Plasmas whose Coulomb-collision rates are very small may relax on shorter time scales to non-Maxwellian quasi-equilibria, which, nevertheless, have a universal form, with dependence on initial conditions retained only via an infinite set of Casimir invariants enforcing phase-volume conservation. These are distributions derived by Lynden-Bell (1967) via a statistical-mechanical entropy-maximisation procedure, assuming perfect mixing of phase-space elements. To show that these equilibria are reached dynamically, one must derive an effective âcollisionless collision integralâ for which they are fixed pointsâunique and inevitable provided the integral has an appropriate H-theorem. We describe how such collision integrals are derived and what assumptions are required for them to have a closed form, how to prove the H-theorems for them, and why, for a system carrying sufficiently large electric-fluctuation energy, collisionless relaxation should be fast. It is suggested that collisionless dynamics may favour maximising entropy locally in phase space before converging to global maximum-entropy states. Relaxation due to interspecies interaction is examined, leading, inter alia, to spontaneous transient generation of electron currents. The formalism also allows efficient recovery of âtrueâ collision integrals for both classical and quantum plasmas
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