Efficient wavelength conversion with high-power passivelyQ-switched diode-pumped neodymium lasers

Powerful CW diode-pumped Nd:YAG and Nd:YVO4 lasers Q-switched by Cr:YAG saturable absorbers demonstrate efficient (30%-60%) harmonic and parametric conversion, generating hundreds of milliwatts from ultraviolet to mid-infrared     

Reconstruction of planar surfaces behind occlusions in range images

Analysis and reconstruction of range images usually focuses on complex objects completely contained in the field of view; little attention has been devoted so far to the reconstruction of simply shaped wide areas like parts of a wall hidden behind furniture pieces in an indoor range image. The work presented in the paper is aimed at such reconstruction. First of all, the range image is partitioned based on depth discontinuities and fold edges. Next, the planes best fitting each of the regions constituting the partition of the image are determined. A third step locates potentially contiguous surfaces, while a final step reconstructs the hidden regions. The paper presents results for reconstruction of the shape of planar surfaces behind arbitrary occluding surfaces. The system proved to be effective and the reconstructed surfaces appear to be reasonable. Some examples of results are presented from the Bornholm church range images     

A Logic Based Asynchronous Multi-Agent System

We present a logic programming based asynchronous multi-agent system in which agents can communicate with one another; update themselves and each other; abduce hypotheses to explain observations, and use them to generate actions. The knowledge base of the agents is comprised of generalized logic programs, integrity constraints, active rules, and of abducibles. We characterize the interaction among agents via an asynchronous transition rule system, and provide a stable models based semantics. An example is developed to illustrate how our approach works.     

A comparison of fuzzy and neuro-fuzzy data fusion for flooded area mapping using SAR images

A comparison of change detection approaches for flooded area mapping using Synthetic Aperture Radar (SAR) images is provided. The aim was to assess the usefulness of fuzzy and neuro-fuzzy techniques for classification of SAR data. The work addresses both options of data-level fusion and decision-level fusion. The former is realized with multitemporal fuzzy or neural classification and the latter by combining classifications or fuzzy memberships for the pre- and post-event images. Highest overall accuracy values and flooded area accuracy values (90.3% producer's, 71.9% user's) were obtained from the neuro-fuzzy approach.     

Copper(I/II), α/β‐Synuclein and Amyloid‐β: Menage à Trois?

Copper binding to α‐synuclein (aS) and to amyloid‐β (Ab) has been connected to Parkinson's and Alzheimer's disease (AD), respectively, because Cu ions can modulate the peptide aggregation, and these Cu ? peptide complexes can catalyse the production of reactive oxygen species (ROS). In a significant proportion of AD brains, aggregation of aS and Ab has been detected, and it was proposed that Ab and aS interact with each other. Thus, we investigated the potential interactions of Ab and aS through their binding of copper(I) and copper(II). Additionally, β‐synuclein (bS) was investigated, due to its additional methionine residue, a potential Cu^I ligand. We found that: 1) the peptides containing the Cu‐binding domains Ab1–16, aS1–15 and bS1–15 have similar affinities towards Cu^II and towards Cu^I, with Ab1–16 being slightly stronger, 2) in the case of Cu^I, the additional Met residue in bS1–15 increased the affinity slightly, 3) the exchange of Cu^I/II between the two peptides is rapid (≤ms), 4) a/bS1–15 and Ab1–16 form a heterodimeric complex with Cu^II, 5) Cu^I probably promotes a transient ternary complex, 6) the different Cu^I/II coordination of Ab1–16, aS1–15 and bS1–15 impacts the capacity to produce ROS and to oxidise catechol, and 7) when Ab1–16, aS1–15 and Cu are present, the ROS production more closely resembles that by Ab1–16. The work gives insights into the coordination chemistry of these related peptides, and the relevance of coordination differences, the ternary complex and ROS production are discussed.     

Mutational analysis of the A-kinase anchoring protein (AKAP)-binding site on RII. Classification Of side chain determinants for anchoring and isoform selective association with AKAPs

Compartmentalization of the type II cAMP-dependent protein kinase is conferred by interaction of the regulatory subunit (RII) with A-Kinase Anchoring Proteins (AKAPs). The AKAP-binding site involves amino-terminal residues on each RII protomer and is formed through dimerization. A site-directed mutagenesis strategy was utilized to assess the contribution of individual residues in either RII isoform, RIIalpha or RIIbeta, for interaction with various anchoring proteins. Substitution of long-chain or bulky hydrophobic groups (leucines or phenylalanines) for isoleucines at positions 3 and 5 in RIIalpha decreased AKAP-binding up to 24 +/- 3 (n = 8)-fold, whereas introduction of valines had minimal effects. Replacement with hydrophilic residues (serine or asparigine) at both positions abolished AKAP binding. Mutation of proline 6 in RIIalpha reduced binding for four AKAPs (Ht31, MAP2, AKAP79, and AKAP95) from 2.3 to 20-fold (n = 4) whereas introduction of an additional proline at position 6 in RIIbeta increased or conferred binding toward these anchoring proteins. Therefore, we conclude that beta-branched side chains at positions 3 and 5 are favored determinants for AKAP-binding and prolines at positions 6 and 7 increase or stabilize RIIalpha interaction with selected anchoring proteins.     

Query-by-shape in meteorological image archives using the pointdiffusion technique

The authors work on meteorological satellite image archives and provide a novel and useful query-by-shape tool. To this aim, they first present the point diffusion technique (PDT), a fast and efficient method for shape similarity evaluation. Thanks to its very structure, this approach is suitable to handle objects whose shape is not well defined and can be represented by a set of sparse points. PDT is thus suitable for application to similarity-based retrieval from remotely sensed image archives, where shapes are hardly defined but are still among the major features of interest. Moreover, they prove here that PDT is almost as effective as more standard procedures for shape-based database queries, although significantly faster. In other words, it manages to combine retrieval speed and precision, the features of greatest importance for a first remote sensing data prescreening in many applications. Archives of meteorological satellite images are typical examples of very large-sized, remote sensing-based databases with a special attention for shape features. Each meteorological satellite produces terabytes of data every day, a large part of which is not immediately analyzed and ends being stored in archives. The application of PDT to such a database is presented and discussed, and a comparison with a standard method developed for meteorological shape analysis is provided     

Optical spectroscopy and diode-pumped laser performance ofNd3+ in the CNGG crystal

We have exploited the broad absorption and emission bandwidth of the laser crystal Ca₃(NbGa)_2-xGa₃O₁₂ doped with Nd³⁺ to develop a tunable and mode locked diode-pumped 1.06 μm laser. We also present the fluorescence and excitation spectra at different crystal temperatures from 10 to 298 K. The spontaneous transition probabilities, the branching ratios, and the radiative lifetime are calculated by means of the Judd-Ofelt theory and compared with the experimental results. The stimulated emission cross-sections of the most important transitions have been calculated and compared with laser results. Employing a 2-W laser diode as a continuous-wave pump source, we have been able to tune the emission wavelength in the range 1053-1074 nm. Active mode-locking yielding pulses of 9.6, 18, and 19.7 ps at the three main emission peaks of 1058.6, 1061.2, and 1065.3 nm, respectively. was also demonstrated     

Chlamydial genital infections and laparoscopic findings in infertile women

Several studies have shown that previous chlamydial genital infection, reflected by serological markers, is strongly associated with tubal damage leading to tubal infertility. In 105 women undergoing laparoscopy, multiple samples were collected from the lower (urethra and cervix) and upper (endometrium, peritoneal fluid, tubal lumen) genital tract, in order to isolate Chlamydia trachomatis in cell culture. Chlamydia trachomatis was isolated from at least one site in 13 (30.9%) of 42 infertile women with tubal infertility, in 5 (12.1%) of 41 women with unexplained infertility, in 1 of 4 women affected by acute salpingitis and in 1 (5.5%) of 18 women with endometriosis or uterine malformations. The latter group was the control group. Thirteen (65%) of the 20 positive women harboured Chlamydia trachomatis in their upper genital tract alone and 16 women were positive in one or both tubes. Only one of the positive women showed laparoscopic signs of acute pelvic infection. Four of the 5 positive women with unexplained infertility harboured Chlamydia trachomatis in the tubal lumen. This study confirms that chlamydial infection is strongly associated with tubal damage. It suggests that cervical cultures are inadequate for excluding a tubal infection and that chlamydial colonization of the tubal mucosa is possible in the absence of symptoms and laparoscopic signs of active infection.     

Design and characterization of a diode-pumped, single longitudinal and transverse mode, intracavity-doubled cw Nd:YAG laser

We report on the experimental results of a diode-pumped, intracavity-doubled cw Nd:YAG laser, pumped by a 10-W fiber-coupled semiconductor laser at 808 nm and emitting as much as 600 mW in a stable single longitudinal mode and TEM(00) spatial mode. We discuss the main issues of the resonator design and the optimization of the intracavity second harmonic conversion by interpreting our results using simple models. Improvements for the current project are also discussed.