Coarse filters for shape matching

This article describes the coarse shape filters that support the 3D, Internet-based search engine ShapeSifter, which aims to locate parts already in production that have a shape similar to a desired new part. The search engine analyzes the target model's shape characteristics and performs a similarity match on the database's contents. Our main challenge is identifying shape metrics that produce effective characterizations of 3D models for similarity comparison. We focus on using three novel convex hull-based indices to carry out a preliminary coarse filtering of candidates prior to more detailed analysis. We also describe the crucial role played by two databases of benchmark objects. Unlike other shape-matching systems, we chose ShapeSifter's architecture (multistep query), 3D representation (triangulated mesh), and implementation (Java3D) to allow deployment online once it matures     

Side-Track Erasure Processes in Perpendicular Recording

In perpendicular recording, substantial erasure of the stored data patterns can occur during the writing process. Among all those erasure processes, side-track erasure (STE) is one of the critical issues in drive head/media integration. Unlike the adjacent track erasure (ATE) process, the locations of the STE affected areas are often many tens of tracks away from the central writing track location. In this work, we report on an experimental investigation and quantification of the general attributes and the origins of the STE processes in various situations. Particularly, we thoroughly characterize some distinctive signatures and behaviors of STE processes by employing both the amplitude- and bit-error-rate-based STE measurement methods in combination with a novel magnetic force microscope characterization technique     

Alterations in reflex function contributing to syncope: orthostatic hypotension, carotid sinus hypersensitivity and drug-induced dysfunction

Orthostatic hypotension and related neurologic symptoms are frequently encountered in clinical practice. The maintenance of appropriate blood pressure and heart rate responses upon assuming the upright posture are dependent upon: 1. intact mechanical (venous valves) mechanisms, 2. functioning arterial and cardiopulmonary baroreceptors, 3. normal peripheral neural pathways, 4. normal central neural integration, and 5. appropriate neurohormonal secretion. Dysfunction at one or more of these loci may facilitate the occurrence of orthostatic hypotension and syncope. In general, the mechanisms of orthostatic hypotension may be divided into three categories. In the first category, processes interfere with normal compensatory responses to upright posture. Examples of this mechanism include age related autonomic changes, diabetic neuropathy and central nervous system disease such as Shy-Drager syndrome. The second principal mechanism involves overwhelming otherwise normal reflexes by an intense orthostatic stimulus. An obvious example of this mechanism is syncope related to hemorrhage. A final category of orthostatic hypotension relates to interference with reflex responses by drugs that may limit vasoconstriction, heart rate or cardiac output adjustments or exaggerate venous pooling. These are commonly used medications such as vasodilators, beta-adrenergic blockers and nitrates. The treatment of orthostatic hypotension revolves around the recognition of underlying causes or contributing factors amenable to correction or avoidance. Other helpful treatment options include nocturnal head-up tilting and mineralocorticoids, both of which help to expand blood volume. Many other therapeutic agents have been tried in small and selected patient populations, often with disappointing results. While many of the drugs available (phenylephrine, ephedrine, tyramine, dihydroergotamine) can improve upright blood pressure, side effects are common, and supine hypertension is problematic in many patients. Interventions of this type should be carefully initiated in a monitored setting. The carotid sinus is an important component of a neural control system responsible for heart rate and blood pressure homeostasis. Excessive heart rate and blood pressure responses to distortion of the carotid sinus are the basis for the carotid sinus syndrome (CSS). Patients with CSS tend to be elderly males and local pathology in the neck is frequently involved. Atherosclerotic coronary artery disease and hypertension are important clinical correlates. Two major categories of carotid sinus hypersensitivity (CSH) are recognized: cardioinhibitory and vasodepressor. Cardioinhibitory CSH is the most common, and in its purest form consists of sinus bradycardia or arrest, asystole or AV block during carotid sinus massage. This vagally-mediated response is eliminated by atropine. Cardiac pacing is nearly universally successful in preventing severe symptoms.(ABSTRACT TRUNCATED AT 400 WORDS)     

The impact of watching television on evening melatonin levels

Self‐luminous electronic devices emit optical radiation at short wavelengths, close to the peak sensitivity of melatonin suppression. The present paper investigated if light from a 178‐cm (70 in.) television suppressed melatonin. Results showed that light from televisions does not impact melatonin levels in the evening.     

Finite-element analysis for magnetic resonance image artifact evaluation

The static magnetic field of a magnetic resonance imaging scanner can be distorted by the presence of materials, perturbing the spatial encoding process in magnetic resonance imaging and often resulting in image artifacts. The relationship between the image artifact size and magnetic susceptibility of the material specimen is of interest to engineers for the design of devices that are to be compatible with the imaging volume of the scanner. In this study, a finite-element method was used to simulate the distorted magnetic field of samples with different susceptibilities. With the knowledge of the external- and self- magnetic field interactions, a Lorentz correction was applied to compute the magnetic field deviation. The simulated results were then validated by the corresponding experimental magnetic resonance images.     

Use of duplex polymerase chain reaction (duplex-PCR) technique to identify bovine and water buffalo milk used in making mozzarella cheese

Molecular biology techniques have been used for species identification in food of animal origin in relatively recent years. A polymerase chain reaction (PCR) based method, the multiplex PCR, was recently applied to species identification in meat and meat products. It allows co-amplification of separate regions of a single gene or specific fragments, each typical of a different animal species in a single PCR reaction, using different pairs of primers in the same reaction mix. In the present paper, the duplex-PCR technique is proposed to identify bovine and water buffalo DNA in a single PCR assay in milk and mozzarella cheese (a typical Italian cheese, originally made from pure water buffalo milk). Because of its lower cost, undeclared bovine milk is added to water buffalo milk for making different kinds of mozzarella cheese. The results of this experiment indicate the applicability of this method, which showed an absolute specificity for the two species and a high sensitivity even down to low DNA concentrations (1 pg). In bovine and water buffalo mixtures of both milk and mozzarella cheese, the minimum concentration tested was 1% of bovine in water buffalo milk and water buffalo in bovine milk. The importance of the somatic cell content in raw milk is also discussed with special reference to the evaluation of mixtures (milk or cheese) of the two species.     

Flexible magnetoinductive ring MRI detector: Design for invariant nearest-neighbour coupling

A flexible birdcage-type resonant RF detector for magnetic resonance imaging is described. The circuit consists of a polygonal ring of magnetically coupled L–C resonators, a periodic structure supporting backward magnetoinductive waves. The elements are mechanically linked to allow relative rotation, and the pivot point is optimised to hold the nearest-neighbour coupling coefficient invariant to small changes in the angle of an undistorted joint. Simple theory based on a parallel wire approximation to rectangular inductors is developed to allow the variation of the coupling coefficient with angle and radius to be estimated, and hence determine the location of the pivot. The optimised pivot is shown to reduce resonance splitting in octagonal rings. However, second-neighbour interactions degrade performance. The theory is verified experimentally using printed circuit board elements coupled by flexible hinges, and the invariance of the nearest-neighbour coupling coefficient is confirmed. Octagonal ring resonators are constructed for operation at 63.8 MHz frequency and the mode spectra of regular and distorted rings are measured. Magnetic resonance imaging properties are investigated using ¹H MRI of simple objects in a 1.5 T field. Images are obtained from undistorted and distorted resonators and the effect of distortion on SNR is quantified.     

Effects of saline stress on mineral composition,phenolic acids and flavonoids in leaves of artichoke and cardoon genotypes grown in floating system

BACKGROUND: Cynara cardunculus is a species native to the Mediterranean basin. It includes globe artichoke and cultivated cardoon as well as their progenitor wild cardoon. The species is a source of biophenols, and its leaf extracts have been widely used in herbal medicine as hepatoprotectors and choleretics since ancient times. The aim of this study was to determine the effect of increasing the level of salinity in the nutrient solution (1 or 30 mmol L^?1 NaCl) on biomass production, mineral composition, radical‐scavenging activity, caffeoylquinic acids and flavonoids in three artichoke (‘Romolo’, ‘Violetto di Provenza’ and ‘Violetto di Romagna’) and three cultivated cardoon (‘Bianco Avorio’, ‘Bianco Gigante Inerme’ and ‘Gigante di Romagna’) cultivars grown in a floating system. RESULTS: Increased salinity in the nutrient solution decreased the leaf dry biomass and leaf number of artichoke and cultivated cardoon cultivars. Salinity reduced macro‐ and microelement accumulation in leaves (e.g. N, K, Ca, Mg, Fe, Mn and B) but improved their antioxidant activity, total polyphenols, chlorogenic acid, cynarin and luteolin. The cultivated cardoons, especially ‘Bianco Avorio’ and ‘Gigante di Romagna’, showed higher biomass and leaf number than those observed in artichoke genotypes. ‘Violetto di Provenza’ exhibited the highest content of chlorogenic acid, closely followed by ‘Violetto di Romagna’, whereas for cynarin content the highest values were recorded in ‘Violetto di Provenza’, ‘Bianco Avorio’ and ‘Gigante di Romagna’. The highest content of luteolin was recorded in ‘Gigante di Romagna’ and ‘Bianco Avorio’, while the highest content of apigenin was observed in ‘Gigante di Romagna’. CONCLUSION: The results showed that the floating system could be considered an effective tool to improve quality aspects through proper management of the salt concentration in the nutrient solution. They also suggest that specific cultivars should be selected to obtain the desired profile of bioactive compounds. © 2012 Society of Chemical Industry