Diseases of the salivary glands in infants and adolescents

<p>Abstract</p> <p>Background</p> <p>Diseases of the salivary glands are rare in infants and children (with the exception of diseases such as parotitis epidemica and cytomegaly) and the therapeutic regimen differs from that in adults. It is therefore all the more important to gain exact and extensive insight into general and special aspects of pathological changes of the salivary glands in these age groups. Etiology and pathogenesis of these entities is still not yet fully known for the age group in question so that general rules for treatment, based on clinical experience, cannot be given, particularly in view of the small number of cases of the different diseases. Swellings of the salivary glands may be caused by acute and chronic inflammatory processes, by autoimmune diseases, by duct translocation due to sialolithiasis, and by tumors of varying dignity. Clinical examination and diagnosis has also to differentiate between salivary gland cysts and inflammation or tumors.</p> <p>Conclusion</p> <p>Salivary gland diseases are rare in childhood and adolescence. Their pattern of incidence differs very much from that of adults. Acute and chronic sialadenitis not responding to conservative treatment requires an appropriate surgical approach. The rareness of salivary gland tumors is particularly true for the malignant parotid tumors which are more frequent in juvenile patients, a fact that has to be considered in diagnosis and therapy.</p

Promoting Reuse with Active Reuse Repository Systems

Abstract. Software component-based reuse is diÆcult for software de-velopers to adopt because rst they must know what components exist in a reuse repository and then they must know how to retrieve them easily. This paper describes the concept and implementation of active reuse repository systems that address the above two issues. Active reuse repository systems employ active information delivery mechanisms to deliver potentially reusable components that are relevant to the current development task. They can help software developers reuse components they did not even know existed. They can also greatly reduce the cost of component location because software developers need neither to specify reuse queries explicitly, nor to switch working contexts back and forth between development environments and reuse repository systems.

The Science Performance of JWST as Characterized in Commissioning

This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

An experimental model of biofilm detachment in liquid fluidized bed biological reactors

Dimensional analysis was applied for the description of biofilm detachment in liquid fluidized bed biological reactors. This technique allowed the identification of the significant parameters influencing detachment mechanisms and suggested suitable experiments for the characterization of involved phenomena. The influence of the significant variables was established on a lab-scale reactor and an empirical model was proposed to correlate experimental results. The detachment rate was strongly dependent on liquid velocity, while the influence of other parameters, such as solid hold-up and liquid shear stress, was found to be less important. (C) 1996 John Wiley & Sons, Inc

Mixing and segregation in water fluidised-bed bioreactors

The complete segregation model, already successfully tested for binary-solid liquid fluidised beds of smooth rigid particles. has been applied to fluidised-bed bioreactors. Qualitative comparison with reported experimental behaviour has shown the capability of the model to predict solid mixing and segregation in these specific types of fluidised beds. (C) 1997 Elsevier Science Ltd

Biomass concentration in fluidized bed biological reactors

Synthetic wastewater treatment was carried out in a fluidized bed biological reactor with sand as support media. Biomass concentration in the bed was measured as total attached solid and recorded together with the bed expansion characteristics throughout the period of operations. A new method to estimate the reactor biomass concentration was developed and tested on the collected data. The method combines the Richardson and Zaki (1954) law for fluidized bed expansion, the definition of overall bed voidage and available literature data on biofilm dry density and gives an estimate of the biomass concentration by means of a non-linear minimization routine using experimental data of bed height versus fluid superficial velocity. The comparison between the values derived from the experimental measures and those calculated by means of the method has proved reasonably successful. (C) 1997 Published by Elsevier Science Ltd

PHOSPHORUS REMOVAL IN FLUIDIZED-BED BIOLOGICAL REACTOR (FBBR)

The biological phosphorus removal in fluidized bed biological reactor (FBBR) has been investigated. The feasibility of excess phosphorus uptake, assured by exposition of biomass to anaerobic-aerobic conditions, has been demonstrated on a bench-scale biofilm reactor working as sequencing batch reactor (SBR) and the limiting parameters have been established. Although the reactor worked effectively, it took several weeks for both acclimatization of biomass and selection of a biofilm rich in poly-P-bacteria. The highest phosphate uptake rates have been observed when strict anaerobic conditions were reached during the anaerobic phase. Using a fluidized bed, a thin biofilm, characterized by high surface/volume ratio and hence highly disposed towards substrate uptake, has been obtained and the overall phosphorus abatement, referred to the biomass present in the reactor, proved particularly effective

Mechanisms of biofilm detachment in fluidized bed reactors

Biofilm detachment in liquid fluidized bed biological reactors was investigated to point out how different mechanisms influence the process. Erosion due to liquid shear and abrasion due to collisions of particles were considered as possible mechanisms of biomass detachment in liquid fluidized beds. A dimensional analysis technique allowed the identification of the significant parameters affecting the process. The influence of these parameters was established on a lab-scale reactor. An empirical model was proposed to correlate the experimental data and to analyze the effect of some characteristic quantities, such as particle Reynolds number, biomass fraction, liquid shear stress and solid concentration, on the detachment rate. Detachment rate strongly increased with fluid velocity while, owing to modifications in biofilm structure and morphology during the biological growth, it slightly decreased with liquid shear stress. (C) 1997 IAWQ. Published by Elsevier Science Ltd