Curvelet based contrast enhancement in fluoroscopic sequences.

Image guided interventions have seen growing interest in recent years. The use of X-rays for the procedure impels limiting the dose over time. Image sequences obtained thereby exhibit high levels of noise and very low contrasts. Hence, the development of efficient methods to enable optimal visualization of these sequences is crucial. We propose an original denoising method based on the curvelet transform. First, we apply a recursive temporal filter to the curvelet coefficients. As some residual noise remains, a spatial filtering is performed in the second step, which uses a magnitude-based classification and a contextual comparison of curvelet coefficients. This procedure allows to denoise the sequence while preserving low-contrasted structures, but does not improve their contrast. Finally, a third step is carried out to enhance the features of interest. For this, we propose a line enhancement technique in the curvelet domain. Indeed, thin structures are sparsely represented in that domain, allowing a fast and efficient detection. Quantitative and qualitative evaluations performed on synthetic and real low-dose sequences demonstrate that the proposed method enables a 50% dose reduction.

Evolution of sperm quality in men living in the vicinity of a municipal solid waste incinerator possibly correlated with decreasing dioxins emission levels.

The objective was to examine the impact on sperm parameters of environmental exposure to dioxins around a municipal waste incinerator initially with high emission levels and during reduction levels. An ecological study with quasi-experimental conditions was performed in patients of a reproductive laboratory. The first semen analyses of 251 men living in Besançon, France, between 2001 and 2007, were included. To analyse the contribution of direct exposure (inhalation), the calendar time was dichotomised in two periods 2001-2003 versus 2004-2007 and used as a proxy for exposure. Regarding the indirect exposure pathway (food), the statistical analysis was made with a nonparametric test to assess the trends. There was a negative correlation between the year of exposure and the percentage of abnormal mid-piece and the multiple abnormalities index, even after adjusting for age and days abstention from inter-course. A positive correlation was found between the progressive motile sperm count and the period of exposure. These findings are to be put into the context of a drastic reduction in emissions of dioxins. Our results suggest an effect of chronic exposure to dioxins on spermiogenesis with more abnormalities. These results should be confirmed with concentration measurements of dioxins in infertile men.

Hypocretin/orexin-containing neurons are produced in one sharp peak in the developing ventral diencephalon.

The birth date of hypocretin-containing neurons was analysed using the bromodeoxyuridine method in the rat. The results indicate that these neurons are generated between embryonic days 11 (E11) and E14, with a sharp peak on E12. This spatiotemporal pattern of genesis contrasts with that of the co-distributed neurons producing the melanin-concentrating hormone in the lateral hypothalamic area, which have been described as generated in one large peak from E10 to E16. These observations may be linked to the relative distribution area of both populations.

Expression of the secreted FAD-dependent sulfydryl oxidase (QSOX) in the guinea pig central nervous system.

cpQSOx1 is a member of the QSOx family of proteins, expressed in the guinea pig (Cavia porcellus) and ortholog of the rat rQSOx1. In this study, in vitro experiments were conducted and showed that, as other member of this family, cpQSOx1 has a sulfydryl oxidase activity, and is a secreted protein. Then, the expression of this enzyme was researched in the guinea pig brain, as very little information exists yet on the expression of QSOx family members in the central nervous system. By immunohistochemistry, RT-PCR and in situ hybridization, cpQSOx1 is synthesized by neurons throughout the whole guinea pig central nervous system. Reticular structures as the basal forebrain, reticular thalamic nucleus and reticular nuclei of the brainstem contained the densest labeling. These results are discussed in terms of putative roles of this protein in synaptic strengthening and in redox activities.

Fourier Transform Spectroscopy of the BaI Molecule: Simultaneous Analysis of Seven Electronic States Including the D(2)Sigma(+) and the G(2)Sigma(+) States.

In this work, the BaI D(2)Sigma(+) and G(2)Sigma(+) electronic states were investigated using laser-induced fluorescence (LIF) and Fourier transform spectroscopy (FTS). The LIF visible spectra were obtained by using the second harmonic of the Ti:sapphire single-mode laser and the Ar(+) and Kr(+) multimode lasers as excitation sources. Previously recorded data, taken from C. A. Leach, A. A. Tsekouras, and R. N. Zare (1992, J. Mol. Spectrosc. 153, 59-72) and from R. F. Gutterres, J. Vergès, and C. Amiot (1999, J. Mol. Spectrosc. 196, 29-44; 2000, J. Mol. Spectrosc. 200, 253-260; and 2000, J. Mol. Spectrosc. 201, 326-327) were combined with the present data. Accurate and improved molecular constants for the X(2)Sigma(+), B(2)Sigma(+), A('2)Delta, A(2)Pi, C(2)Pi, and D(2)Sigma(+) states and 16 term values of the G(2)Sigma(+) state were derived from a simultaneous treatment of the whole data set (12 684 transitions) with a standard deviation of 3.26x10(-3) cm(-1). Copyright 2001 Academic Press.

The E(2)Sigma(+) --> C(2)Pi Transition of NO and Term Values for the A, D, E, and C Lowest Rydberg Levels.

The E(2)Sigma(+) --> C(2)Pi Rydberg-Rydberg transition of (14)N(16)O near 8492 cm(-1) has been studied by Fourier transform spectrometry in the emission from a dc excited supersonic jet expansion and from a dc discharge under equilibrium conditions. The same transition has also been observed in laser-induced stimulated emission. Line wavenumbers of the 0-0, 1-1, and 2-2 bands, together with data for previously published near-infrared transitions, have been reduced to consistent sets of rovibronic term values for v = 0, 1, and 2 of the A(2)Sigma(+), D(2)Sigma(+), E(2)Sigma(+), and C(2)Pi states which frequently serve as intermediates in the multiphoton excitation of higher Rydberg levels of NO. Copyright 2000 Academic Press.

The KRb (2)(3)Sigma(+) Electronic State.

High-resolution spectra of the (3)(1)Pi --> (2)(3)Sigma(+) system of the KRb molecule, obtained after excitation with fixed frequencies Ar(+) laser lines, were recorded on a Connes-type Fourier transform interferometer. Molecular constants of the first 14 vibrational levels of the (2)(3)Sigma(+) state are determined. The RKR potential energy curve is derived. The main spectroscopic constants for this triplet electronic state of the (39)K (85)Rb isotopic species are T(e) = 13 507.146(2) cm(-1), omega(e) = 48.6385(6) cm(-1), B(e) = 0.0254152(5) cm(-1), gamma = 0.00164(4) cm(-1), epsilon = -0.469(2) cm(-1), R(e) = 4.98345 Å, 𝒟(e) = 3447 cm(-1). Copyright 2000 Academic Press.

High-Resolution Study of the BaI A(2)Pi Electronic State.

Near-infrared and visible spectra of the A(2)Pi-X(2)Sigma(+), C(2)Pi(1/2)-A(2)Pi(1/2), C(2)Pi(1/2)-B(2)Sigma(+), and C(2)Pi(1/2)-X(2)Sigma(+) band systems of the BaI molecule were recorded by using Fourier transform spectroscopy (FTS). The spectra were produced from the chemiluminescent reaction Ba + I(2) and also by using laser-induced fluorescence (LIF) technique in which the laser sources were a Ti:sapphire single-mode laser, a dye single-mode laser, and a Kr(+) multimode ion laser. Resolved rotational data, originating from 19 vibrational levels (0

The RbCs X(1)Sigma(+) Ground Electronic State: New Spectroscopic Study.

In this paper a new spectroscopic investigation on the X(1)Sigma(+) electronic ground state of the RbCs molecule is reported. This study is conducted by using laser-induced fluorescence combined with Fourier transform spectroscopy (LIF-FTS). More than 23 000 spectral data are used in a global linear reduction to molecular constants. With these new and improved molecular constants, the potential energy curve has been calculated by the inverted perturbation approach (IPA). Accurate values for the dissociation energy and the long-range parameters have been derived. Copyright 1999 Academic Press.

The BaI X2Sigma+ and B2Sigma+ Electronic States Through B2Sigma+-X2Sigma+ and C2Pi-X2Sigma+ Band Systems Analysis.

The near-infrared spectrum of the B2Sigma+-X2Sigma+ band system of the BaI molecule, obtained from the chemiluminescent reaction Ba + I2 and also by laser-induced fluorescence (LIF), was recorded by using Fourier transform spectroscopy (FTS). The LIF spectra were obtained by using a Ti:sapphire single-mode laser excitation. Resolved rotational data, originating from 32 vibrational levels (0