Diverse Inflammatory Response After Cerebral Microbleeds Includes Coordinated Microglial Migration and Proliferation.

BACKGROUND AND PURPOSE:Cerebral microbleeds are linked to cognitive decline, but it remains unclear how they impair neuronal function. Infarction is not typically observed near microbleeds, suggesting more subtle mechanisms, such as inflammation, may play a role. Because of their small size and largely asymptomatic nature, real-time detection and study of spontaneous cerebral microbleeds in humans and animal models are difficult. METHODS:We used in vivo 2-photon microscopy through a chronic cranial window in adult mice to follow the inflammatory response after a cortical microhemorrhage of ≈100 µm diameter, induced by rupturing a targeted cortical arteriole with a laser. RESULTS:The inflammatory response included the invasion of blood-borne leukocytes, the migration and proliferation of brain-resident microglia, and the activation of astrocytes. Nearly all inflammatory cells responding to the microhemorrhage were brain-resident microglia, but a small number of CX3CR1+ and CCR2+ macrophages, ultimately originating from the invasion of blood-borne monocytes, were also found near the lesion. We found a coordinated pattern of microglia migration and proliferation, where microglia within 200 µm of the microhemorrhage migrated toward the lesion over hours to days. In contrast, microglia proliferation was not observed until ≈40 hours after the lesion and occurred primarily in a shell-shaped region where the migration of microglia decreased their local density. These data suggest that local microglia density changes may trigger proliferation. Astrocytes activated in a similar region as microglia but delayed by a few days. By 2 weeks, this inflammatory response had largely resolved. CONCLUSIONS:Although microhemorrhages are small in size, the brain responds to a single bleed with an inflammatory response that involves brain-resident and blood-derived cells, persists for weeks, and may impact the adjacent brain microenvironment

Observational Constraints on the Averaged Universe

Averaging in general relativity is a complicated operation, due to the general covariance of the theory and the non-linearity of Einstein's equations. The latter of these ensures that smoothing spacetime over cosmological scales does not yield the same result as solving Einstein's equations with a smooth matter distribution, and that the smooth models we fit to observations need not be simply related to the actual geometry of spacetime. One specific consequence of this is a decoupling of the geometrical spatial curvature term in the metric from the dynamical spatial curvature in the Friedmann equation. Here we investigate the consequences of this decoupling by fitting to a combination of HST, CMB, SNIa and BAO data sets. We find that only the geometrical spatial curvature is tightly constrained, and that our ability to constrain dark energy dynamics will be severely impaired until we gain a thorough understanding of the averaging problem in cosmology.Comment: 6 pages, 4 figure

Distributed collaboration between industry and university partners in HE

Over the past three years the School of Design has been experimenting with an innovative curriculum design and delivery model named ‘the Global Studio’. The Global Studio is a cross-institutional research informed teaching and learning collaboration conducted between Northumbria University and international universities and industry partners based in the UK, USA, Netherlands and Korea. The aims of the Global Studio are directly linked with current and future industry needs that are related to changes in the organisation of product and service development. These changes highlight the importance of equipping design students with skills for working in globally networked organisations particularly the development of skills in intercultural communication and collaboration. In this paper we will focus on the Global Studio conducted in 2008 which included Northumbria University (UK), Hongik University (Korea), Auburn University (USA), Intel (USA), Motorola design studios located in the UK and Korea and Great Southern Wood (USA). These projects will be used to illustrate challenges and benefits of international collaborative industry-based projects undertaken in distributed settings

Direct synthesis of timed asynchronous circuits

Journal ArticleThis paper presents a new method to synthesize timed asynchronous circuits directly from the specification without generating a state graph. Our synthesis procedure begins with a deterministic signal transition graph specification to which timing constraints can be added. First, a timing analysis extracts the timed concurrency relation and timed causality relation between any two signal transitions. Then, a hazard-free implementation under the timing constraints is synthesized by constructing a precedence graph and finding a shortest path in the graph. Our method does not have the state explosion problem while the synthesized circuits have nearly the same area with the previous timed circuits

Laser Induced Optical Pumping Measurements of Cross Sections for Fine and Hyperfine Structure Transitions in Sodium Induced by Collisions with Helium Argon Atoms

Optical pumping of the ground states of sodium can radically alter the shape of the laser induced fluorescence excitation spectrum, complicating measurements of temperature, pressure, etc., which are based on these spectra. Modeling of the fluorescence using rate equations for the eight hyperfine states of the sodium D manifolds can be used to quantify the contribution to the ground state pumping of transitions among the hyperfine excited states induced by collisions with buffer gas atoms. This model is used here to determine, from the shape of experimental spectra, cross sections for (Delta)F transitions of the P(sub 3/2) state induced by collisions with helium and argon atoms, for a range of values assumed for the P(sub 1/2), (Delta)F cross sections. The hyperfine cross sections measured using this method, which is thought to be novel, are compared with cross sections for transitions involving polarized magnetic substates, m(sub F), measured previously using polarization sensitive absorption. Also, fine structure transition ((Delta)J) cross sections were measured in the pumped vapor, giving agreement with previous measurements made in the absence of pumping

Excellence in Supervision: Theories of Supervision

This essay identifies and reviews seven theoretical frameworks for how AFTE members understand supervision.  Each summary includes key references for that theory

Line Parameters including Temperature Dependences of Air- and Self-broadened Line Shapes of (CO2)-C-12-O-16: 2.06-mu m Region

This study reports the results from analyzing a number of high resolution, high signal-to-noise ratio (S/N) spectra in the 2.06-μm spectral region for pure CO2 and mixtures of CO2 in dry air. A multispectrum nonlinear least squares curve fitting technique has been used to retrieve the various spectral line parameters. The dataset includes 27 spectra: ten pure CO2, two 99% 13C-enriched CO2 and fifteen spectra of mixtures of 12C-enriched CO2 in dry air. The spectra were recorded at various gas sample temperatures between 170 and 297 K. The absorption path lengths range from 0.347 to 49 m. The sample pressures for the pure CO2 spectra varied from 1.1 to 594 Torr; for the two 13CO2 spectra the pressures were ∼10 and 146 Torr. For the air-broadened spectra, the pressures of the gas mixtures varied between 200 and 711 Torr with CO2 volume mixing ratios ranging from 0.014% to 0.203%. The multispectrum fitting technique was applied to fit simultaneously all these spectra to retrieve consistent set of line positions, intensities, and line shape parameters including their temperature dependences; for this, the Voigt line shape was modified to include line mixing (via the relaxation matrix formalism) and quadratic speed dependence. The new results are compared to select published values, including recent ab initio calculations. These results are required to retrieve the column averaged dry air mole fraction (XCO2) from space-based observations, such as the Orbiting Carbon Observatory-2 (OCO-2) satellite mission that NASA launched in July 2014

Ion Write Microthermotics: Programing Thermal Metamaterials at the Microscale.

Considerable advances in manipulating heat flow in solids have been made through the innovation of artificial thermal structures such as thermal diodes, camouflages, and cloaks. Such thermal devices can be readily constructed only at the macroscale by mechanically assembling different materials with distinct values of thermal conductivity. Here, we extend these concepts to the microscale by demonstrating a monolithic material structure on which nearly arbitrary microscale thermal metamaterial patterns can be written and programmed. It is based on a single, suspended silicon membrane whose thermal conductivity is locally, continuously, and reversibly engineered over a wide range (between 2 and 65 W/m·K) and with fine spatial resolution (10-100 nm) by focused ion irradiation. Our thermal cloak demonstration shows how ion-write microthermotics can be used as a lithography-free platform to create thermal metamaterials that control heat flow at the microscale

Visualizing Alzheimer's Disease Mouse Brain with Multispectral Optoacoustic Tomography using a Fluorescent probe, CDnir7

Alzheimer's disease (AD) is now clinically considered as a chronic inflammation-based neurodegenerative disease. The CDnir7 probe was previously developed as an optical imaging probe to target macrophages in order to image mouse inflammation using in vivo optical imaging modalities such as In Vivo imaging system (IVIS) and fluorescent molecular tomography (FMT). Here, we demonstrate the application of CDnir7 in AD mouse brain imaging via multispectral optoacoustic tomography (MSOT). Longitudinal MSOT imaging of CDnir7 showed higher CDnir7 localization in AD mouse cerebral cortex compared to that of normal mice. MSOT signals of CDnir7 localization in mouse brain were verified by ex vivo near-infrared (NIR) imaging and immunohistochemistry. Histological evaluation showed strong CDnir7 staining in AD cerebral cortex, hippocampus, basal ganglia and thalamus area. Based on the supporting evidence, CDnir7 has great potential as a molecular imaging probe for AD brain imaging.11Ysciescopu