Immunoradiometric assay of Ca 125 in breast cystic fluid

Ca 125 was assayed in serum and in breast cyst fluid of 78 patients with GCD. Levels of the marker in cyst fluid are generally < 30 U/ml. More significative results were found in relation to cysts relapse. In apocrine cysts relapse levels were higher than 270 U/ml, in serum cysts not relapsed levels were between 31-270 U/ml. Ca 125 could have a significative role in cell differentiation and its control.     

A VNS heuristic for escaping local extrema entrapment in normalized cut clustering

Normalized cut is one of the most popular graph clustering criteria. The main approaches proposed for its resolution are spectral clustering methods and a multilevel approach of Dhillon et al. (TPAMI 29:1944–1957, 2007), called graclus. Their aim is to obtain good solutions in a small amount of time for large instances. Metaheuristics are general frameworks for stochastic searches often employed in global optimization to improve the solutions obtained by other heuristics. Variable neighborhood search (VNS) is a metaheuristic which exploits systematically the idea of neighborhood change during the search. In this paper, we propose a VNS heuristic for normalized cut segmentation. Computational experiments show that in most cases this VNS heuristic improves significantly, and in moderate time, the solutions obtained by the current state-of-the-art algorithms, i.e., graclus and a spectral method proposed by Yu and Shi (ICCV, 2003).     

A covert attention P300-based brain-computer interface: Geospell

The Farwell and Donchin P300 speller interface is one of the most widely used brain-computer interface (BCI) paradigms for writing text. Recent studies have shown that the recognition accuracy of the P300 speller decreases significantly when eye movement is impaired. This report introduces the GeoSpell interface (Geometric Speller), which implements a stimulation framework for a P300-based BCI that has been optimised for operation in covert visual attention. We compared the Geospell with the P300 speller interface under overt attention conditions with regard to effectiveness, efficiency and user satisfaction. Ten healthy subjects participated in the study. The performance of the GeoSpell interface in covert attention was comparable with that of the P300 speller in overt attention. As expected, the effectiveness of the spelling decreased with the new interface in covert attention. The NASA task load index (TLX) for workload assessment did not differ significantly between the two modalities. PRACTITIONER SUMMARY: This study introduces and evaluates a gaze-independent, P300-based brain-computer interface, the efficacy and user satisfaction of which were comparable with those off the classical P300 speller. Despite a decrease in effectiveness due to the use of covert attention, the performance of the GeoSpell far exceeded the threshold of accuracy with regard to effective spelling.     

Parallel synchronous and asynchronous coupled simulated annealing

The Journal of Supercomputing - We propose a parallel synchronous and asynchronous implementation of the coupled simulated annealing (CSA) algorithm in a shared-memory architecture. The original...     

Bimetallic Zeolite Catalyst for CO2 Reforming of Methane

The catalytic activity of Ni–Rh on the synthesized BEA zeolite in carbon dioxide reforming of methane has been investigated. Catalysts were prepared using the incipient wetness impregnation method, with a total content of metals up to 5 wt%. Catalysts were characterized through XRD, TPR, N₂ adsorption, SEM, AAS, TG/DSC analyses. The prepared Ni–Rh zeolites were tested for their catalytic activity at 700 °C, at atmospheric pressure, and at CH₄/CO₂ ratio of 1. Catalytic results showed that bimetallic based zeolites exhibit high activity (CH₄ and CO₂ conversion equal to 73 and 78, respectively) but monometallic Rh catalysts were the only one stable against coke formation.     

A multimode navigation system for an assistive robotics project

Assistive technology is an emerging area, where robotic devices can help individuals with motor disabilities to achieve independence in daily activities. This paper deals with a system that provides remote control of Sony AIBO, a commercial mobile robot, within the assistive project ASPICE. The robot can be controlled by various input devices, including a Brain-Computer Interface. AIBO has been chosen for its friendly-looking aspect, in order to ease interaction with the patients. The development of the project is described by focusing on the design of the robot navigation system. Single step, semi-autonomous and autonomous navigation modes have been realized to provide different levels of control. Automatic collision avoidance is integrated in all cases. Other features of the system, such as the video feedback from the robotic platform to the user, and the use of AIBO as communication aid, are briefly described. The performance of the navigation system is shown by simulations as well as experiments. The system has been clinically validated, in order to obtain a definitive assessment through patient feedback.

The role of echography in the determination and monitoring of ductal ectasia in nipple discharge

In this study a good sensibility of ultrasound in identifying ductal disease was demonstrated. We evaluated the relationship between nipple discharge and ductal ectasia and the importance of the ectasia in maintaining nipple discharge. From our data the hypothesis of a possible role of oestroprogestinic hormones in the genesis or maintaining of ductal ectasia emerged.     

Catalytic behavior in propane aromatization using GA-MFI catalyst

Ga-Al-MFI samples were synthesized in hydrothermal conditions from gels of composition 1.08CH₃NH₂- 0.134TPABr-1SiO₂-xAl₂O₃-yGa₂O₃-40H₂O at 175 ℃ for 7 days, with x = 0.005 and 0.0025, y = 0.005, 0.010 and 0.020. The samples were characterized by XRD, BET measurements, thermal analysis (TGA-DTA) atomic absorption and high resolution solid state MAS ²⁷Al and ⁷¹Ga NMRmeasurements. The aromatization of propane was studied as catalytic test. The activity and selectivity of the catalysts were determined for benzene, toluene and xylenes on the one hand and for methane and ethane on the other hand. The most active sample was obtained with the highest Ga/Al ratio. For this sample, the BTX selectivity obtained by aromatizationwas always higher than the hydrocracking selectivity leading tomethane and ethane. The relative amount of toluenewas higher than that of benzene and of xylenes. The samples were deactivated by coke formation thatwas revealedmore severe for the most active sample.     

A Lagrangian-based score for assessing the quality of pairwise constraints in semi-supervised clustering

Clustering algorithms help identify homogeneous subgroups from data. In some cases, additional information about the relationship among some subsets of the data exists. When using a semi-supervised clustering algorithm, an expert may provide additional information to constrain the solution based on that knowledge and, in doing so, guide the algorithm to a more useful and meaningful solution. Such additional information often takes the form of a cannot-link constraint (i.e., two data points cannot be part of the same cluster) or a must-link constraint (i.e., two data points must be part of the same cluster). A key challenge for users of such constraints in semi-supervised learning algorithms, however, is that the addition of inaccurate or conflicting constraints can decrease accuracy and little is known about how to detect whether expert-imposed constraints are likely incorrect. In the present work, we introduce a method to score each must-link and cannot-link pairwise constraint as likely incorrect. Using synthetic experimental examples and real data, we show that the resulting impact score can successfully identify individual constraints that should be removed or revised.

     

NP-hardness of Euclidean sum-of-squares clustering

A recent proof of NP-hardness of Euclidean sum-of-squares clustering, due to Drineas et al. (Mach. Learn. 56:9–33, 2004), is not valid. An alternate short proof is provided.