Identification of Pups and Yearling Wolves by Dentine Width in the Canine

One hundred and thirty-nine wolf (Canis lupus) skulls and mandibles were collected from hunters and trappers of northern Quebec and Labrador during the winters of 1980-81 through 1983-84. The maximum width of the dentine-cementum wall in wolf canine teeth was used to separate pups killed late in their first year from yearlings killed early in their second winter of life. Both age classes may have a closed foramen at the apex of the root and a clear deposit of cementum with no opaque annulus.Key words: wolf (Canis lupus), canine teeth, dentine width, pups versus yearlingsMots clés: loup (Canis lupus), canines, épaisseur de la dentine, louveteaux contre loups âgés d'un a

Notes on the Birds of Southampton Island, Northwest Territories

During the summers of 1970 and 1971, 46 species were seen on Southampton Island, most in the interior of the island where previous records were scarce. A comparison with observations in 1932 suggests little change in the status of the avifauna of the island over the past 40 years

The Bailey Point Region and Other Muskox Refugia in the Canadian Arctic: A Short Review

The muskox (Ovibos moschatus) is widely distributed over much of arctic Canada but only at a few locations do their densities remain high and populations relatively stable. These refugia constitute the most favourable muskox ranges in the Canadian Arctic Archipelago .... Refugia for muskoxen in the High Arctic include lowlands on eastern Axel Heiberg Island in the Mokka Fiord region, the lowlands of northeastern Devon Island, and the Bailey Point region of Melville Island .... All of those regions historically have supported high densities of muskoxen from time to time but the Bailey Point region must be considered the best habitat for muskoxen in the Canadian High Arctic. ..

Direct grating writing: single-step Bragg grating and waveguide fabrication for telecommunications and sensing applications

Direct Grating Writing (DGW) has been developed over the past decade as a means of rapidly prototyping waveguides with integrated Bragg grating structures in silica-on-silicon substrates [1]. The technique allows complicated waveguide structures and Bragg grating arrays to be fabricated and characterised in house

An integrated optical Bragg grating refractometer for volatile organic compound detection

We report an integrated optical Bragg grating detector, fabricated using a direct UV-writing approach, that when coated with a thin-film of a hydrophobic siloxane co-polymer can perform as an all-optically accessed detector for hydrocarbon vapour. Upon exposure to a series of organic solvent vapours, both negative and positive Bragg wavelength shifts of differing magnitudes were measured. This was attributed to a combination of swelling and/or hydrocarbon solvent filling the free volume within the polymer film. A quantitative structural property relationship (QSPR) approach was utilised to create a multiple variable linear regression model, built from parameters that chemically described the hydrocarbons and the intermolecular interactions present between the co-polymer and hydrocarbon molecules. The resulting linear regression model indicated that the degree of swelling of the polysiloxane thin film when exposed to vapours of different hydrocarbons was due to the physico-chemical properties of the hydrocarbons and that this was the main causative factor of the measured Bragg wavelength shifts. Furthermore, this linear regression model allows for the prediction of the Bragg wavelength shift that would be measured upon exposure to vapours of another defined hydrocarbon. This detector is intrinsically safe in flammable environments. It includes on-chip thermal compensation, operates at telecoms wavelengths and has a predictable response to a variety of hydrocarbons making it ideal for detection of flammable hydrocarbon vapours in industrial and domestic processes

The Detection of Incipient Caries with Tracer Dyes

The purpose of this study was to determine the increase in color contrast produced by the use of a tracer dye in detection of incipient caries lesions with transillumination. Twenty four caries-free first premolars were immersed in an acid gelatin for production of artificial incipient caries lesions. After the lesions had developed, these teeth were photographed by transillumination. Two photographs were taken of each tooth. The first photograph showed the lesion without dye. A blue tracer dye was then added and absorbed by the lesion, and a second photograph was taken. The data on the color difference were obtained by use of a reflectance colorimeter and showed a four-fold increase between the lesion and surrounding area with the dye. A two-way analysis of variance was used for the statistical interpretation. The color difference between the lesion without the dye and then with the dye was significant. The use of the blue tracer dye, therefore, significantly increased the contrast in the images of the artificial incipient lesions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68289/2/10.1177_00220345890680021101.pd

Image Quality Assessment Using Spatial Frequency Component

Image quality assessment (IQA) is a crucial technique in perceptual image/video coding, because it is not only a ruler for performance evaluation of coding algorithms but also a metric for ratio-distortion optimization in coding. In this paper, inspired by the fact that distortions of both global and local information influence the perceptual image quality, we propose a novel IQA method that inspects these information in the spatial frequency components of the image. The distortion of the global information mostly existing in low spatial frequency is measured by a rectified mean absolute difference metric, and the distortion of the local information mostly existing in high spatial frequency is measured by SSIM. These two measurements are combined using a newly proposed abruptness weighting that describes the uniformity of the residual image. Experimental results on LIVE database show that the proposed metric outperforms the SSIM and achieves performance competitive with the state-of-the-art metrics. ? 2009 Springer-Verlag Berlin Heidelberg.EI

Mutations of the BRAF gene in human cancer

Cancers arise owing to the accumulation of mutations in critical genes that alter normal programmes of cell proliferation, differentiation and death. As the first stage of a systematic genome-wide screen for these genes, we have prioritized for analysis signalling pathways in which at least one gene is mutated in human cancer. The RAS RAF MEK ERK MAP kinase pathway mediates cellular responses to growth signals. RAS is mutated to an oncogenic form in about 15% of human cancer. The three RAF genes code for cytoplasmic serine/threonine kinases that are regulated by binding RAS. Here we report BRAF somatic missense mutations in 66% of malignant melanomas and at lower frequency in a wide range of human cancers. All mutations are within the kinase domain, with a single substitution (V599E) accounting for 80%. Mutated BRAF proteins have elevated kinase activity and are transforming in NIH3T3 cells. Furthermore, RAS function is not required for the growth of cancer cell lines with the V599E mutation. As BRAF is a serine/threonine kinase that is commonly activated by somatic point mutation in human cancer, it may provide new therapeutic opportunities in malignant melanoma

Particle interactions with single or multiple 3D solar reconnecting current sheets

The acceleration of charged particles (electrons and protons) in flaring solar active regions is analyzed by numerical experiments. The acceleration is modelled as a stochastic process taking place by the interaction of the particles with local magnetic reconnection sites via multiple steps. Two types of local reconnecting topologies are studied: the Harris-type and the X-point. A formula for the maximum kinetic energy gain in a Harris-type current sheet, found in a previous work of ours, fits well the numerical data for a single step of the process. A generalization is then given approximating the kinetic energy gain through an X-point. In the case of the multiple step process, in both topologies the particles' kinetic energy distribution is found to acquire a practically invariant form after a small number of steps. This tendency is interpreted theoretically. Other characteristics of the acceleration process are given, such as the mean acceleration time and the pitch angle distributions of the particles.Comment: 18 pages, 9 figures, Solar Physics, in pres

Magnetoluminescence

Pulsar Wind Nebulae, Blazars, Gamma Ray Bursts and Magnetars all contain regions where the electromagnetic energy density greatly exceeds the plasma energy density. These sources exhibit dramatic flaring activity where the electromagnetic energy distributed over large volumes, appears to be converted efficiently into high energy particles and gamma-rays. We call this general process magnetoluminescence. Global requirements on the underlying, extreme particle acceleration processes are described and the likely importance of relativistic beaming in enhancing the observed radiation from a flare is emphasized. Recent research on fluid descriptions of unstable electromagnetic configurations are summarized and progress on the associated kinetic simulations that are needed to account for the acceleration and radiation is discussed. Future observational, simulation and experimental opportunities are briefly summarized.Comment: To appear in "Jets and Winds in Pulsar Wind Nebulae, Gamma-ray Bursts and Blazars: Physics of Extreme Energy Release" of the Space Science Reviews serie