A theoretical/experimental program to develop active optical pollution sensors

Light detection and ranging (LIDAR) technology was applied to the assessment of air quality, and its usefulness was evaluated by actual field tests. Necessary hardware was successfully constructed and operated in the field. Measurements of necessary physical parameters, such as SO2 absorption coefficients were successfully completed and theoretical predictions of differential absorption performance were reported. Plume modeling improvements were proposed. A full scale field test of equipment, data analysis and auxiliary data support was conducted in Maryland during September 1976

Fluorescent carbon dioxide indicators

Over the last decade, fluorescence has become the dominant tool in biotechnology and medical imaging. These exciting advances have been underpinned by the advances in time-resolved techniques and instrumentation, probe design, chemical / biochemical sensing, coupled with our furthered knowledge in biology. Complementary volumes 9 and 10, Advanced Concepts of Fluorescence Sensing: Small Molecule Sensing and Advanced Concepts of Fluorescence Sensing: Macromolecular Sensing, aim to summarize the current state of the art in fluorescent sensing. For this reason, Drs. Geddes and Lakowicz have invited chapters, encompassing a broad range of fluorescence sensing techniques. Some chapters deal with small molecule sensors, such as for anions, cations, and CO2, while others summarize recent advances in protein-based and macromolecular sensors. The Editors have, however, not included DNA or RNA based sensing in this volume, as this were reviewed in Volume 7 and is to be the subject of a more detailed volume in the near future

High-sensitivity troponin I concentrations are a marker of an advanced hypertrophic response and adverse outcomes in patients with aortic stenosis

Aims: High-sensitivity cardiac troponin I (cTnI) assays hold promise in detecting the transition from hypertrophy to heart failure in aortic stenosis. We sought to investigate the mechanism for troponin release in patients with aortic stenosis and whether plasma cTnI concentrations are associated with long-term outcome. Methods and results: Plasma cTnI concentrations were measured in two patient cohorts using a high-sensitivity assay. First, in the Mechanism Cohort, 122 patients with aortic stenosis (median age 71, 67% male, aortic valve area 1.0 ± 0.4 cm2) underwent cardiovascular magnetic resonance and echocardiography to assess left ventricular (LV) myocardial mass, function, and fibrosis. The indexed LV mass and measures of replacement fibrosis (late gadolinium enhancement) were associated with cTnI concentrations independent of age, sex, coronary artery disease, aortic stenosis severity, and diastolic function. In the separate Outcome Cohort, 131 patients originally recruited into the Scottish Aortic Stenosis and Lipid Lowering Trial, Impact of REgression (SALTIRE) study, had long-term follow-up for the occurrence of aortic valve replacement (AVR) and cardiovascular deaths. Over a median follow-up of 10.6 years (1178 patient-years), 24 patients died from a cardiovascular cause and 60 patients had an AVR. Plasma cTnI concentrations were associated with AVR or cardiovascular death HR 1.77 (95% CI, 1.22 to 2.55) independent of age, sex, systolic ejection fraction, and aortic stenosis severity. Conclusions: In patients with aortic stenosis, plasma cTnI concentration is associated with advanced hypertrophy and replacement myocardial fibrosis as well as AVR or cardiovascular death

VLASSICK: The VLA Sky Survey in the Central Kiloparsec

At a distance of 8 kpc, the center of our Galaxy is the nearest galactic nucleus, and has been the subject of numerous key projects undertaken by great observatories such as Chandra, Spitzer, and Herschel. However, there are still no surveys of molecular gas properties in the Galactic center with less than 30" (1 pc) resolution. There is also no sensitive polarization survey of this region, despite numerous nonthermal magnetic features apparently unique to the central 300 parsecs. In this paper, we outline the potential the VLASS has to fill this gap. We assess multiple considerations in observing the Galactic center, and recommend a C-band survey with 10 micro-Jy continuum RMS and sensitive to molecular gas with densities greater than 10^4 cm^{-3}, covering 17 square degrees in both DnC and CnB configurations ( resolution ~5"), totaling 750 hours of observing time. Ultimately, we wish to note that the upgraded VLA is not just optimized for fast continuum surveys, but has a powerful correlator capable of simultaneously observing continuum emission and dozens of molecular and recombination lines. This is an enormous strength that should be fully exploited and highlighted by the VLASS, and which is ideally suited for surveying the center of our Galaxy.Comment: 13 pages, 3 figures, a White Paper submitted to provide input in planning the Very Large Array Sky Surve

Molecular gas in the northern nucleus of Mrk273: Physical and chemical properties of the disk and its outflow

Aiming to characterise the properties of the molecular gas in the ultraluminous infrared galaxy Mrk273 and its outflow, we used the NOEMA interferometer to image the dense gas molecular tracers HCN, HCO+, HNC, HOC+ and HC3N at 86GHz and 256GHz with angular resolutions of 4.9x4.5 arcsec (3.7x3.4 kpc) and 0.61x0.55 arcsec (460x420 pc). We also modelled the flux of several H2O lines observed with Herschel using a radiative transfer code that includes excitation by collisions as well as by far-infrared photons. The disk of the Mrk273 north nucleus has two components with decoupled kinematics. The gas in the outer parts (1.5 kpc) rotates with a south-east to north-west direction, while in the inner disk (300 pc) follows a north-east to south-west rotation. The central 300 pc, which hosts a compact starburst region, is filled with dense and warm gas, contains a dynamical mass of (4-5)x10^9M_sun, a luminosity of L'_HCN=(3-4)x10^8 K km/s pc^2, and a dust temperature of 55 K. At the very centre, a compact core with R~50 pc has a luminosity of L_IR=4x10^11L_sun (30% of the total infrared luminosity), and a dust temperature of 95 K. The core is expanding at low velocities ~50-100 km/s, probably affected by the outflowing gas. We detect the blue-shifted component of the outflow, while the red-shifted counterpart remains undetected in our data. Its cold and dense phase reaches fast velocities up to ~1000 km/s, while the warm outflowing gas has more moderate maximum velocities of ~600 km/s. The outflow is detected as far as 460 pc from the centre in the northern direction, and has a mass of dense gas <8x10^8M_sun. The difference between the position angles of the inner disk (~70 degree) and the outflow (~10 degree) indicates that the outflow is likely powered by the AGN, and not by the starburst. Regarding the chemistry, we measure an extremely low HCO+/HOC+ ratio of 10+-5 in the inner disk of Mrk273.Comment: Accepted for publication in A&A. 21 pages, 17 figures, 7 tables, and a lot of interesting tex

Surface Screening Charge and Effective Charge

The charge on an atom at a metallic surface in an electric field is defined as the field-derivative of the force on the atom, and this is consistent with definitions of effective charge and screening charge. This charge can be found from the shift in the potential outside the surface when the atoms are moved. This is used to study forces and screening on surface atoms of Ag(001) c$(2\times 2)$ -- Xe as a function of external field. It is found that at low positive (outward) fields, the Xe with a negative effective charge of -0.093 $|{e}|$ is pushed into the surface. At a field of 2.3 V \AA$^{-1}$ the charge changes sign, and for fields greater than 4.1 V \AA$^{-1}$ the Xe experiences an outward force. Field desorption and the Eigler switch are discussed in terms of these results.Comment: 4 pages, 1 figure, RevTex (accepted by PRL