2,838 research outputs found

    Inhibition of tumor necrosis factor α–stimulated monocyte adhesion to human aortic endothelial cells by AMP-activated protein kinase

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    <b>Objective</b>— 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>— 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>— 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

    Increasing Access to the James River Park System: A Community Roadmap with the Blackwell, Oak Grove, and Bellemeade Neighborhoods

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    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

    Bosonic molecules in a lattice: unusual fluid phase from multichannel interactions

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    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

    You Can Change the World With a Haircut”: Evaluating the Feasibility of a Barber-led Intervention for Men of Black and Ethnic Minority Heritage to Manage High Blood Pressure

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    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 (1.5 h) and face-to-face (3 h) 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 236 BP recordings, of which 39 (16.53%) were over 140/90 mmHg; of these, 5 were over 180/100 mmHg. 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

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    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 Γ, and an inhomogeneous, Doppler component, which is a squared Gaussian. The width of the inhomogeneous component is reduced by a factor of √2 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 4Γ, whereas in the limit of dominant homogeneous broadening, the predicted width is 2Γ. 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 Σ - X2 Π(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

    The mineralogy and chemistry of the anorogenic Tertiary silicic volcanics of S.E. Queensland and N.E. New South Wales, Australia

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    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

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    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 (Mon. Not. R. Astron. Soc., vol. 136, 1967, p. 101) 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 ∝Δ−2, where Δ 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

    Non-thermal particle acceleration and power-law tails via relaxation to universal Lynden-Bell equilibria

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    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 ∝Δ−2\propto \varepsilon^{-2}, where Δ\varepsilon 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

    Collisionless relaxation of a Lynden-Bell plasma

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    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 ‘collisionless collision integral’ for which they are fixed points—unique 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 ‘true’ collision integrals for both classical and quantum plasmas
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