Search

Copyright of Annali di Igiene, Medicina Preventiva e di Comunità is the property of Societa Editrice Universo s.r.l. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We deal with the problem of human facial expression recognition from digital images. A digital image is preprocessed for feature extraction using moment descriptors; then, it is represented in the product lattice (픽100,≤) of Intervals' Numbers (INs). Learning as well as generalization are carried out in space (픽100, ≤) by two different Fuzzy Lattice Reasoning (FLR) classifiers based on an inclusion measure function σ: 픽100 x 픽100 → [0, 1]. We pursue both a stochastic optimization and a parallel implementation of the proposed techniques. Comparative experimental results on three benchmark data sets demonstrate a superior performance of the proposed FLR classification schemes. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine whether a radial shaft fracture would decrease the protection provided to the posterior interosseous nerve by the pronation maneuver during posterolateral exploration. The position of the nerve in 14 cadaveric elbows, before and after a radial osteotomy, was determined using CT scans in full supination and full pronation after injection of the nerve with radio-opaque dye. The angle formed by the olecranon, radial head and posterior interosseous nerve, and the distance between the nerve and the most lateral aspect of the radial head were measured.Pronation increased the distance between the lateral radial head and the nerve by a mean of 6.5 mm (range 3.6–10.7). After radial osteotomy, the mean increase was 4.2 mm (range 1.0–8.3), difference 2.3 mm (p = 0.044, 95% CI 0.10 to 3.33). The posterolateral approach requires additional care in the presence of a radial shaft fracture, but pronation is still beneficial. [ABSTRACT FROM PUBLISHER]

In this study, a method of fabricating lateral carbon nanotube (CNT)-based field emission triodes is discussed. The device, tested here in a diode configuration, consists of CNT emitters grown laterally from an etched quartz sidewall using thermal chemical vapor deposition. The lateral CNT growth is facilitated by a novel two-step angled evaporation technique. This method allows a Ni catalyst to be selectively deposited along the cathodic sidewall while burying all other regions of exposed Ni in a thick Ti layer thus preventing unwanted CNT growth. The lateral CNT emitters demonstrated turn-on fields as low as ∼1.2 V/μm for a total anode current of ∼10 nA. The CNT emitters, with an estimated emitting area of 3.8×10-6 cm2, achieved a current of ∼3.0 μA at an applied field of ∼2.0 V/μm corresponding to a current density of approximately 800 mA/cm2. The temperature dependence of the emission is also investigated. [ABSTRACT FROM AUTHOR]

Owing to their simplicity, two migration models based on Fick's Second Law have been frequently used for the assessment of migration of additives and contaminants from food-packaging films. While the two models are known to provide accurate estimates of diffusion coefficients for complete migration, they could generate considerable estimation errors for significantly partitioned migration. In this paper, the applicability of the two models to partitioned migration is defined by examining the assumptions and derivations of the two models as well as their errors in estimating diffusion coefficients. Furthermore, a simple migration model, based on more realistic assumptions than the two models, is proposed. The proposed model can provide far better estimates of diffusion coefficients for partitioned migration than the two models. [ABSTRACT FROM AUTHOR]

The residence times of the components of two- and threecomponent mixtures of fine (195 μm), coarse (1315 μm) and very coarse (5040 μm) sands were measured in a pilot-scale cascading rotary dryer. The effects of mixture composition and air velocity (0-5.4ms[sup -1]) were determined. With no air flowing through the drum, the residence times of the individual components were almost the same as that of the overall mixture. Increasing the gas velocity caused a large decrease in residence time. In contrast, particle size had very little effect. The spread of residence times increased with air velocity, peaking between 2 and 4ms[sup -1]; composition had very little effect on the spread. The residence time of the overall mixture could be calculated using the particle transport model of Matchett and Baker if both the modified drag coefficient φ[sub d] and the particle Reynolds number Rep were based on the superficial air velocity and the mass-average particle diameter. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the potential of a microgenetic algorithm (MGA) [genetic algorithm (GA) with small population and short evolution] as a generalized hill-climbing operator. Combining a standard GA with the suggested MGA operator leads to a hybrid genetic scheme GA-MGA, with enhanced searching qualities. The main GA performs global search while the MGA explores a neighborhood of the current solution provided by the main GA, looking for better solutions. In contrast to conventional hill climbers that attempt independent steps along each axis, the MGA operator performs genetic local search. The major advantage of MGA is its ability to identify and follow narrow ridges of arbitrary direction leading to the global optimum. The proposed GA-MGA scheme is tested against 13 different schemes, including a simple GA and GAs with different hi!l-climbing operators. Experiments are conducted on a test set including eight constrained optimization problems with continuous variables. Extensive simulation results demonstrate the efficiency of the proposed GA-MGA scheme. For the same number of fitness evaluations, GA-MGA exhibited a significantly better performance in terms of solution accuracy, feasibility percentage of the attained solutions, and robustness. [ABSTRACT FROM AUTHOR]

The authors present their experience in the operative treatment of unstable lesions at the cervicothoracic junction. Ten patients, six men and four women, underwent operative procedures at the cervicothoracic junction (C7-T1) between 1990 and 1997. Six patients had sustained fracture-dislocations, three patients had metastases and one patient had a primary malignant lesion. All the patients had significant cervical pain and neurologic deficit. The spinal cord and nerves were decompressed in all cases. Posterior stabilization was accomplished using various types of implants including hooks, wires and rods. Anteriorly, the spine was stabilized with plates and screws. Partial or complete vertebrectomy was performed in five cases and a titanium cylinder or an iliac autograft replaced the vertebral body. Five patients were submitted to a posterior operation only, and the other five to bilateral procedures. In four of these a one-stage operation was performed and in the last case a two-stage procedure. The anatomic and biomechanical characteristics of the cervicothoracic junction require a precise pre-operative analysis of the local anatomy and the selection of the proper implants for anterior and posterior stabilization. [ABSTRACT FROM AUTHOR]

We demonstrate the dielectrophoretic control of metallic nanowires (NWs) in liquid suspensions. By varying a range of parameters including the magnitude and frequency of the applied electric field, the liquid suspending the NWs, and the flow conditions, we demonstrate control over NW network formation and dissolution, as well as ordering of NWs into vertically aligned arrays. These results suggest a straightforward strategy for NW assembly and integration in devices. [ABSTRACT FROM AUTHOR]

We present a quartz tuning-fork-based atomic force microscopy (AFM) setup that is capable of mapping the surface contact resistance while scanning topography. The tuning-fork setup allows us to use etched Pt/Ir tips, which have higher durability and better conductivity than probes used in earlier AFM conductance measurements. The performance of the method is demonstrated with contact resistance measurements of gold lines on silicon dioxide and carbon nanotubes on graphite. [ABSTRACT FROM AUTHOR]

We report on the fabrication of nanometer-scale mechanical devices incorporating multiwalled carbon nanotubes (MWNTs) as the torsional spring elements. We have employed electron beam lithography to pattern device elements directly onto individual MWNTs on a silicon dioxide substrate. The structures were suspended by etching the substrate and subsequent critical-point drying of the sample. We also briefly present characterization of the torsional properties of an individual MWNT. The techniques described are applicable to other nanometer-scale rod-like objects. [ABSTRACT FROM AUTHOR]

We report on the precise placement of a single carbon nanotube (CNT) onto a microlectromechanial system (MEMS) structure. Using a hybrid atomic force microscope/scanning electron microscope (AFM/SEM) system, an individual multiwalled CNT was retrieved from a cartridge by the AFM tip, translated to a MEMS device, and then placed across a gap between an actuating and a stationary structure. Progress toward a resistance versus stress/strain measurement on a CNT will be discussed, including SEM images of a MEMS structure we have designed specifically for such a measurement. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We report improvements in the quality of two-dimensional (2D) electrons in modulation-doped AlAs quantum wells, leading to electron mobilities as high as 31 m²/Vs, a ten-fold increase over the mobility of previous AlAs samples. Confirming the quality of our quantum wells, developing fractional quantum Hall states are observed in the first Landau level at high order filling factors v=2/5, 3/5, 3/7, 4/7, and 4/9, and at larger fillings, at v=4/3, 5/3, 7/3, 8/3, 8/5, and 11/3. Thanks to the much larger effective mass and g factor of AlAs 2D electrons compared to GaAs, and to the possible multivalley occupancy of AlAs 2D electrons, our improved systems help bring a wider scope to the investigation of low-disorder, interacting 2D electrons. [ABSTRACT FROM AUTHOR]

PURPOSE: We undertook this retrospective survey of Musculoskeletal Ultrasound (MSUS) examinations performed by musculoskeletal radiologists in order to assess the current workload as well as the impact of MSUS on the diagnosis and management of rheumatology patients. MATERĠALS and METHODS: This is a retrospective review of MSUS scans in a 6 month period. On all patients, additional data was collected for areas scanned, findings, influence on diagnosis and the impact on management. RESULTS: A total of 30 patients were scanned during this 6 month period: 22 (75%) patients were referred by rheumatology and 8 (25%) by orthopaedics. 45% of areas scanned were hands, wrists 26%, shoulders 13%, feet 10%, knees 5% and ankles 1%. Most common findings were synovitis(45%), effusion(30%), tenosynovitis (25%) and rotator cuff tendinopathy (10%). Following the scan, the diagnosis was revised by the clinician and a definitive diagnosis was established in 80% of patients. In 10(33) % patients there was a change in management following the scan. 25% had a change in disease modifying medication, 20% had an intra-articular steroid injection and 10% were referred to physiotherapy. In 6% patients, injection was withheld and disease modifying therapy was withheld in 5% patients. 2 patients were discharged following the scan. Only 5% patients required a further investigation (MRI) due to inconclusive MSUS. CONCLUSĠON: A substantial amount of MSUS workload of radiologists is contributed by rheumatology. There is a significant influence of MSUS on rheumatological diagnostic process with a definitive diagnosis being established in a large number of patients. [ABSTRACT FROM AUTHOR]

This paper reviews the spin orientation of spin-3/2 holes in quantum wells. We discuss the Zeeman and Rashba spin splitting in hole systems that are qualitatively different from their counterparts in electron systems. We show how a systematic understanding of the unusual spin-dependent phenomena in hole systems can be gained using a multipole expansion of the spin density matrix. As an example we discuss spin precession in hole systems that can give rise to an alternating spin polarization. Finally, we discuss the qualitatively different regimes of hole spin polarization decay in clean and dirty samples. [ABSTRACT FROM AUTHOR]

The encapsulation of thymol and geraniol in β-cyclodextrin (β-CD) and modified starch (MS) by spray- and freeze-drying was studied. The formation of thymol/β-CD and geraniol/β-CD inclusion complexes was confirmed by differential scanning calorimetry (DSC). Oxidative DSC revealed that the monoterpenes enclosed in the β-CD cavity were protected against oxidation, remaining intact in temperatures at which free monoterpenes were oxidized. Phase solubility studies showed that the inclusion complexes of thymol and geraniol with β-CD are more soluble in water than the free molecules themselves. Furthermore, in order to evaluate the fraction of monoterpenes that can be released from their complexes with MS in aqueous media, a series of release experiments were conducted. [ABSTRACT FROM AUTHOR]