1,133 research outputs found
Le Nouveau-Brunswick : Pour que cette crise serve Ă quelque chose
Une crise en puissance guette le Nouveau-Brunswick. Bien quâelle soit de nature Ă©conomique, elle pourrait rendre le Nouveau-Brunswick de plus en plus difficile Ă gouverner, Ă moins quâon ne sây attaque avec un sentiment dâurgence. Le Nouveau-Brunswick doit relever toute une sĂ©rie de dĂ©fis Ă©conomiques : un dĂ©ficit structurel, une population vieillissante, lâincertitude entourant les transferts fĂ©dĂ©raux, une croissance anĂ©mique de lâĂ©conomie, une Ă©conomie mondiale extrĂȘmement concurrentielle et une incapacitĂ© Ă attirer de nouveaux Canadiens. Cet article soutient que le Nouveau-Brunswick ne doit pas rater lâoccasion quâoffre cette crise et quâil doit envisager de faire des choses « quâil ne pensait pas pouvoir faire auparavant ». Cet article affirme que la communautĂ© universitaire de la province doit exercer un certain leadership afin de sâassurer que cette crise serve Ă quelque chose
New Brunswick: Letâs Not Waste a Crisis
New Brunswick is staring at a crisis in the making. The crisis is economic in nature but, unless it is addressed with a sense of urgency, it may well make New Brunswick increasingly difficult to govern. The province is confronting a host of economic challenges: a structural deficit, an aging population, uncertainty surrounding federal transfers, sluggish economic growth, a highly competitive global economy, and an inability to attract new Canadians. The paper argues that New Brunswick should not waste a crisis and consider doing things that it "could not do before." The paper maintains that the provinceâs academic community has an important role to play in ensuring that New Brunswick does not waste the looming crisis
Optical thickness as related to pollutant episodes and the concentration of visibility degrading pollutants
A network of six sun photometers was placed in the central and northeast United States during the months of July through October, 1931. The objective of the program was to obtain measurements of atmospheric turbidity which can be related to the concentration of visibility-degrading pollutants in the atmosphere. These measurements serve as ground truth for a program to develop remote sensing techniques for measuring the vertically integrated aerosol concentrations in pollution episodes. The sun photometers measure the direct solar radiation in four passbands: 380 nm, 500 nm, 875 nm and 940 nm. The first three passbands will be used for measuring the aerosol optical depth and the last for measuring precipitable water
Explicit Error Bounds for Spline Interpolation on a Uniform Partition
AbstractThis paper considers the optimality and the evaluation of the constants that appear in the expressions of error bounds for interpotating spline functions over a uniform mesh of the real line when the nodes are uniformly shifted
Development of PDT/PET theranostics: synthesis and biological evaluation of an ÂčâžF-radiolabeled water soluble porphyrin
Synthesis of the first water-soluble porphyrin radiolabeled with fluorine-18 is described: a new molecular theranostic agent which integrates the therapeutic selectivity of photodynamic therapy (PDT) with the imaging efficacy of positron emission tomography (PET). Generation of the theranostic was carried out through the conjugation of a cationic water-soluble porphyrin bearing an azide functionality to a fluorine-18 radiolabeled prosthetic bearing an alkyne functionality through click conjugation, with excellent yields obtained in both cold and hot synthesis. Biological evaluation of the synthesized structures shows the first example of an 18 F-radiolabeled porphyrin retaining photocytotoxicity following radiolabeling and demonstrable conjugate uptake and potential application as a radiotracer in vivo. The promising results gained from biological evaluation demonstrate the potential of this structure as a clinically relevant theranostic agent, offering exciting possibilities for the simultaneous imaging and photodynamic treatment of tumors
On the optical properties of carbon nanotubes--Part I. A general formula for the dynamical optical conductivity
This paper is the first one of a series of two articles in which we revisit
the optical properties of single-walled carbon nanotubes (SWNT). Produced by
rolling up a graphene sheet, SWNT owe their intriguing properties to their
cylindrical quasi-one-dimensional (quasi-1D) structure (the ratio length/radius
is experimentally of order of 10^3). We model SWNT by circular cylinders of
small diameters on the surface of which the conduction electron gas is confined
by the electric field generated by the fixed carbon ions. The pair-interaction
potential considered is the 3D Coulomb potential restricted to the cylinder. To
reflect the quasi-1D structure, we introduce a 1D effective many-body
Hamiltonian which is the starting-point of our analysis. To investigate the
optical properties, we consider a perturbation by a uniform time-dependent
electric field modeling an incident light beam along the longitudinal
direction. By using Kubo's method, we derive within the linear response theory
an asymptotic expansion in the low-temperature regime for the dynamical optical
conductivity at fixed density of particles. The leading term only involves the
eigenvalues and associated eigenfunctions of the (unperturbed) 1D effective
many-body Hamiltonian, and allows us to account for the sharp peaks observed in
the optical absorption spectrum of SWNT.Comment: Comments: 24 pages. Revised version. Accepted for publication in
J.M.
Comparisons of trace constituents from ground stations and the DC-8 aircraft during PEM-West B
Chemical data from ground stations in Asia and the North Pacific are compared with data from the DC-8 aircraft collected during the Pacific Exploratory Measurements in the Western Pacific Ocean (PEM-West B) mission. Ground station sampling took place on Hong Kong, Taiwan, Okinawa, and Cheju; and at three Pacific islands, Shemya, Midway, and Oahu. Aircraft samples were collected during 19 flights, most over the western North Pacific. Aluminum was used as an indicator of mineral aerosol, and even though the aircraft did sample Asian dust, strong dust storms were not encountered. The frequency distribution for non-sea-salt sulfate (nss SO4=) in the aircraft samples was bimodal: the higher concentration mode (âŒ1 ÎŒg mâ3) evidently originated from pollution or, less likely, from volcanic sources, while the lower mode, with a peak at 0.040 ÎŒg mâ3, probably was a product of biogenic emissions. In addition, the concentrations of aerosol sulfate varied strongly in the vertical: arithmetic mean SO4=concentrations above 5000 m ( = 0.21±0.69 ÎŒg mâ3) were substantially lower than those below ( = 1.07±0.87 ÎŒg mâ3), suggesting the predominance of the surface sources. Several samples collected in the stratosphere exhibited elevated SO4=, however, probably as a result of emissions from Mount Pinatubo. During some boundary layer legs on the DC-8, the concentrations of CO and O3 were comparable to those of clean marine air, but during other legs, several chemically distinct air masses were sampled, including polluted air in which O3was photochemically produced. In general, the continental outflow sampled from the aircraft was substantially diluted with respect to what was observed at the ground stations. Higher concentrations of aerosol species, O3, and CO at the Hong Kong ground station relative to the aircraft suggest that much of the continental outflow from southeastern Asia occurs in the lower troposphere, and extensive long-range transport out of this part of Asia is not expected. In comparison, materials emitted farther to the north apparently are more susceptible to long-range transport
Mechanisms of growth inhibition of primary prostate epithelial cells following gamma irradiation or photodynamic therapy including senscence, necrosis, and autophagy, but not apoptosis
In comparison to more differentiated cells, prostate cancer stem-like cells are radioresistant, which could explain radio-recurrent prostate cancer. Improvement of radiotherapeutic efficacy may therefore require combination therapy. We have investigated the consequences of treating primary prostate epithelial cells with gamma irradiation and photodynamic therapy (PDT), both of which act through production of reactive oxygen species (ROS). Primary prostate epithelial cells were cultured from patient samples of benign prostatic hyperplasia and prostate cancer prior to treatment with PDT or gamma irradiation. Cell viability was measured using MTT and alamar blue assay, and cell recovery by colony-forming assays. Immunofluorescence of gamma-H2AX foci was used to quantify DNA damage, and autophagy and apoptosis were assessed using Western blots. Necrosis and senescence were measured by propidium iodide staining and beta-galactosidase staining, respectively. Both PDT and gamma irradiation reduced the colony-forming ability of primary prostate epithelial cells. PDT reduced the viability of all types of cells in the cultures, including stem-like cells and more differentiated cells. PDT induced necrosis and autophagy, whereas gamma irradiation induced senescence, but neither treatment induced apoptosis. PDT and gamma irradiation therefore inhibit cell growth by different mechanisms. We suggest these treatments would be suitable for use in combination as sequential treatments against prostate cancer
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