The DVB-H Mobile Broadcast Standard

The digital video broadcasting-handheld (DVB-H) standard is one of the latest transmission standards developed by the digital video broadcasting (DVB) Project. DVB-H, which is based on the standard for digital terrestrial television (DVB-T), offers mobile television and other broadcasting services on small portable devices such as mobile phones. This article presents an overview of the DVB-H standard with respect to structure, features, technology, performance, and resources.     

Enabling Full Conversion Reaction with High Reversibility to Approach Theoretical Capacity for Sodium Storage

Conversion‐type electrode materials are emerging as promising candidates for high‐energy rechargeable batteries, owing to their substantially higher theoretical capacity relative to intercalation‐based materials. Nevertheless, the full benefit from conversion‐type electrode materials remains out of reach in sodium‐ion batteries, due to the inadequate conversion reaction toward sodium and the poor reversibility during desodiation. Here, a full conversion reaction with high reversibility is demonstrated through promoting the initial sodium intercalation and subsequent reconversion kinetics by transition metal doping. The doping‐induced lowering of the sodium intercalation energy in thermodynamics effectively drives the full conversion reaction, while the metal transition of the doped element enhances reconversion kinetics in achieving high reversibility. The obtained results open a new avenue for the development of high‐performance conversion‐type electrodes and provide a novel understanding of the conversion reaction mechanism.     

Influence of Al2O3 or ZrO2 particulate addition on the microstructure aspects of AlNi and AlSi alloys

Different metal/ceramic composites (Al7Si0.3Mg, Al3Ni, Al6Ni, Al9Ni) reinforced with Al₂O₃ or ZrO₂ were prepared by vortex method. Metallographic investigations reveal that in all the composites -Al did not nucleate on the reinforcement particulates. The particulates were generally observed to be located in the last freezing regions regardless of matrix alloy, particulate type or size. The reason for that was the mismatch in the thermal diffusivity between the ceramic particulates and matrix alloys. SEM micrographs show that the presence of the particulates in the AlSi alloy tends to modify the silicon eutectic. In contrast, the addition of the particulates into AlNi alloys did not result in a significant modification of the NiAl₃ phase, but it displaced the eutectic point to lower Ni content.     

Results and efficiency of programmed ventricular stimulation with four extrastimuli compared with one, two, and three extrastimuli

BACKGROUND: Conventional programmed ventricular stimulation protocols are inefficient compared with more recently proposed protocols. The purpose of the present study was to determine if additional efficiency could be derived from a 6-step programmed ventricular stimulation protocol that exclusively uses four extrastimuli. METHODS AND RESULTS: The subjects were 209 consecutive patients with coronary artery disease and documented sustained monomorphic ventricular tachycardia, nonsustained ventricular tachycardia, aborted sudden death, or syncope. These patients underwent 159 electrophysiological tests in the absence of antiarrhythmic drug therapy and 105 electrophysiological tests in the presence of antiarrhythmic therapy. Programmed stimulation was performed with two protocols in random order in each patient. Both protocols used an eight-beat drive train, 4-s intertrain pause, and basic drive cycle lengths of 350, 400, and 600 ms. The 6-step protocol started with coupling intervals of 290, 280, 270, and 260 ms, which were shortened simultaneously in 10-ms steps until S2 was refractory. The 18-step protocol used one, two and three extrastimuli in conventional sequential fashion. The end points were 30 s of sustained monomorphic ventricular tachycardia, two episodes of polymorphic ventricular tachycardia requiring cardioversion, or completion of the protocol at two right ventricular sites. There was no significant difference in the yield of sustained monomorphic ventricular tachycardia using the two protocols, regardless of the clinical presentation or treatment with antiarrhythmic drugs. Polymorphic ventricular tachycardia occurred with the 18-step protocol twice as frequently as with the 6-step protocol (6% versus 3%, P < .001). The duration of the 18-step protocol was significantly longer than that of the 6-step protocol in patients with inducible ventricular tachycardia (5.5 +/- 7 versus 2.3 +/- 2 minutes, P < .001), as well as in patients without inducible ventricular tachycardia (25.4 +/- 7 versus 6.9 +/- 2 minutes, P < .001). CONCLUSION: A stimulation protocol that exclusively uses four extrastimuli improves the specificity and efficiency of programmed ventricular stimulation without compromising the yield of monomorphic ventricular tachycardia in patients with coronary artery disease.     

The effect of Bacillus subtilis and Streptococcus faecalis var. liquefaciens on staphylococcal enterotoxin A activity

The effect of growing Bacillus subtilis and Streptococcus faecalis var. liquefaciens on staphylococcal growth, thermonuclease (TNase) activity and enterotoxin A (SEA) activity was investigated in liquid media and in foods. Abundant growth of B. subtilis or S. faecalis var. liquefaciens decreased purified SEA concentrations during a 2-day incubation in brain heart infusion broth (BHI) and supernatant fluid by 89 and 67%, respectively. Both staphylococcal TNase activity and SEA concentrations decreased when S. aureus was cultivated in the presence of B. subtilis or S. faecalis var. liquefaciens. Staphylococcal TNase activity decreased by 75 and 78% in the presence of B. subtilis and S. faecalis var. liquefaciens, respectively, while SEA activity decreased by 95 and 65%, respectively, in the presence of those test strains. The results obtained with artificially contaminated sterile chicken or beef samples were similar to those obtained with BHI broth. S. aureus grew very well in heated vegetables. TNase was undetectable, although SEA could be detected. In the presence of B. subtilis or S. faecalis var. liquefaciens, SEA activity was decreased to a non-detectable concentration.     

Effectiveness of iron therapy on breath-holding spells

OBJECTIVE: The objective of this study is to investigate the effect of iron therapy on breath-holding spells (BHS). METHODOLOGY: Sixty-seven children with BHS were enrolled in a clinical trial to evaluate the effect of iron therapy on BHS. At the beginning of therapy, the clinical, laboratory, and demographic characteristics of the patients in the treatment group (n = 33) and placebo group (n = 34) were comparable. Patients were assessed weekly for the first 8 weeks and then every 2 weeks for the next 8 weeks. Response to therapy was assessed by the change in the frequency of BHS. RESULTS: Children treated with iron showed significant reduction in the frequency of BHS (88%) compared with the frequency (6%) in the placebo group. As expected, the treated group showed a significant improvement of a number of blood indexes compared with the placebo group. Baseline mean levels of hemoglobin and total iron binding capacity were predictive of a favorable response to iron treatment. CONCLUSION: Results of this study indicate that iron therapy is effective in the treatment of BHS and that iron-deficient children seem to be more likely to benefit from such therapy. Response to iron therapy was strongly correlated with improvement in blood indexes.     

Concrete deterioration in a 20-year-old structure in Kuwait

This paper presents the laboratory evaluation of concrete samples cut from a 20-year-old office building in Kuwait suffering from concrete deterioration. The building exemplifies structures built in the 50's and 60's using limited quality control and site machinery. In situ nondestructive tests were performed on elements with variable degrees of visible defects. The physical, mechanical and chemical properties of concrete cores were determined. Pulse velocity and hammer tests were applied to lab-prepared samples and results were compared with the performance of field samples. The effect of field condition was also studied. Causes of deterioration were obtained using advanced physical chemistry techniques including x-ray diffraction and the scanning electron microscope along with wet chemistry methods. The correlation between physical and mechanical properties was studied to evaluate the significance and reliability.     

A biomimetic reach and grasp approach for mechanical hands

Reach and grasp are the two key functions of human prehension. The Central Nervous System controls these two functions in a separate but interdependent way. The choice between different solutions to reach and grasp an object–provided by multiple and redundant degrees of freedom (dof)–depends both on the properties and on the use (affordance) of the object to be manipulated. This same control paradigm, i.e. subdivision of prehension into reach and grasp as well as the corresponding multimodal (sensory/motor) information fusion schemes, can also be applied to a mechanical hand carried by a robotic arm. The robotic arm will then be responsible for positioning the hand with respect to the object, and the hand will then grasp and manipulate the object. In this article, we present a biomimetic sensory–motor control scheme in the aim of providing an object-dependent and intelligent reach and grasp ability to such systems. The proposed model is based on a multi-network architecture which incorporates multiple Matching Units trained by a statistical learning algorithm (LWPR). Matching Units perform a multimodal signal integration by correlating sensory and motor information analogous to that observed in cerebral neuronal networks. The simulated network of multiple Matching Units provided estimations of object-dependent 5-finger grasp configurations with endpoint positional errors in the order of a few millimeters. For validation, these estimations were then applied to the control of movement kinematics on an experimental robot composed of a 6 dof robot arm carrying a 16 dof mechanical 4-finger hand. Precision of the kinematics control was such that successful reach, grasp and lift was obtained in all the tests.     

Thirty cases of duplication of the thumb. Operative results

Thirty cases of duplication of the thumb have been seen during a period of 8 years. Twenty-four children underwent surgery for a total of 25 operations, and these are reviewed after a follow-up of at least a year. Wassel's type IV was the most frequent type, occurring in 14 cases. There were 23 primary operations, and 2 reoperations for frontal deviation, which were secondary to operations done elsewhere. The average age at the time of operation was 16 months, the mean follow-up is 4 years (1 to 8 years). The results are analyzed according to Wassel's criteria. Regardless of the location of the duplication, function is unaffected, the structure of the thumb is good, and the parents are satisfied. However, examination revealed some loss of mobility in 10 cases, shortening of the thumb in 5 cases, instability of the collateral ligament in 3 cases and axis deviation in 10 cases. Six of these were clinodactyly at the IP, 1 a clinodactyly at the MP and 3 Z-shaped deformities at the IP and MP. The two reoperations were done to correct a significant loss of alignment, and in each the result was upgraded from "poor" to "fair". It seems that the end results are determined at the original operation which should be done before the 18th month. The thumb with the least function, usually on the radial side, is resected and the remaining component reconstructured. This includes centralization of the insertions of the extrinsic muscles, and reinsertion of the thenar muscles. Immobilization by pinning is usually done due to the need for an osteotomy during the surgery for realignment of the axis of the thumb. It must, however, always be remembered that this surgery is cosmetic rather than functional.     

Long-term genotoxic effect of monocrotophos in different tissues of freshwater fish Channa punctatus (Bloch) using alkaline single cell gel electrophoresis

Monocrotophos, commonly known as azodrin, is one of the organophosphate pesticides extensively used in agricultural practices throughout the world. However, little information is available on its long-term genotoxic effects in different tissues of fish using genotoxicity biomarkers. The objective of the present study was to detect DNA damage, induced by monocrotophos in freshwater teleost fish Channa punctatus using the comet assay. The LC(50)-96 h value of technical-grade monocrotophos was estimated for the fish species in a semi-static system. On the basis of the LC(50) value, the sublethal and nonlethal concentrations were determined. The DNA damage was measured in the gill, kidney and lymphocytes as the percentage of DNA in comet tails of fish exposed to different sublethal and nonlethal concentrations of monocrotophos. In general, significant effects (P<0.01) from both concentration and time of exposure were observed in exposed fish. It was found that the tissues at all concentrations exhibited the highest DNA damage on day 4, after which there was a decline in percentage tail DNA. The comparison of DNA damage among tissues at different concentrations indicated that the gill cells were more sensitive to the pesticide than the kidney cells and lymphocytes. This study also explored the utility of the comet assay for in vivo laboratory studies using fish for screening the genotoxic potential of various agents.