The architecture of a middleware layer for controlling the quality of multimedia sessions

Collaborative multimedia systems demand overall session quality control beyond the level of Quality of Service (QoS) as pertaining to individual streams in isolation of others. To this end, we have recently introduced the concept of Quality of Session (QoSess) control. At every instant in time, the quality of the session depends on the actual QoS offered by the system to each of the application streams, as well as on the relative priorities of these streams according to the application semantics. In this paper, we present the architecture of a middleware layer for controlling the quality of a session. In addition, we describe the inter-stream bandwidth adaptation mechanisms, which are used by the QoSess layer to dynamically control the bandwidth shares of the streams belonging to a session. This revised version was published online in July 2006 with corrections to the Cover Date.     

Pheromone trapping of the sugarcane weevil borer, Rhabdoscelus obscurus (Boisduval) (Coleoptera: Curculionidae): an evaluation of trap design and placement in the field

Abstract  The sugarcane weevil borer ( Rhabdoscelus obscurus ) is a pest of sugarcane and palm plantations in high rainfall areas of far north Queensland. Pheromone mass trapping of adult borers is an effective method of monitoring and may also impact on their population densities. Trials to evaluate different designs of pheromone trap showed the 'water trap' to be the most effective in capturing the highest number of adult borers. The water trap is a 20 cm-diameter pot with a plastic bag inserted to hold water with pheromone lures and cane pieces held together in a plastic container suspended over the water from a square of wire mesh. Results also showed that adult borers in adjacent fields are able to sense the lures and migrate into treated fields. The sex ratio of captured borers in split-cane traps (which is a standard population monitoring tool) was male biased from February to April but was more balanced later in the year. However, the pheromone traps mainly attracted female borers all year round, except during May. Thus, we recommend pheromone traps to be deployed early in the season (November to early December) to attract the maximum number of adult females at a critical time for the population as it starts to build up. In addition, placing pheromone traps inside cane paddocks did not improve the total catch in most cases. Therefore, placing pheromone traps under the shade of trees outside the paddock or at the edge of the paddock under sugarcane can be a feasible mass trapping method that can easily be implemented by cane growers.     

Enhancement of nitrogen fixation in lentil,faba bean,and soybean by dual inoculation with Rhizobia and mycorrhizae

The combined effect of Vesicular Arbuscular Mycorrhizae (VAM) and Rhizobium on the cold season legumes, lentil and faba bean, as well as on summer legume, soybean, were studied in soils with low indeginous VA mycorrhizal spores. Inoculation of the plant with VA mycorrhizal fungi increased the level of mycorrhizal root infection of lentil, faba bean and soybean. The inoculation with Rhizobium had no significant effect on VA mycorrhizal infection percent, but VA mycorrhizal inoculation increased nodulation of the three legumes. The inoculation with Rhizobium alone significantly increased plant dry weight and N content of lentil and faba bean as well as seed yield of soybean. VA mycorrhizal inoculation also significantly increased plant dry weight and phosphorus content of the plants as did fertilization with superphosphate. Rock phosphate fertilization, however, had no significant effect on plant growth or phosphorus uptake. The addition of rock phosphate in combination with VA mycorrhizal inoculation significantly increased plant dry weight and P uptake of the plants. The dual inoculation with both rhizobia and mycorrhizae induced more significant increases in plant dry weight, N and P content of lentil and faba bean as well as seed yield of soybean than inoculation with either VA mycorrhizae or Rhizobium alone.     

Some Factors Affecting Fermentation Capacity and Net Growth of Rumen Microorganisms

The fermentation rate of rumen microorganisms obtained from a sheep fed on hay was determined at different hours after feeding. The highest rate of fermentation was obtained immediately after feeding whereas the lowest rate was always before feeding. The effect of adding glucose, sucrose, and starch alone or in combination with urea, sodium citrate, or succinic acid on the maximal fermentation rate was studied. In no case was the maximal fermentation rate greater than that obtained in the presence of concentrate and straw. An investigation on the effect of C/N ratios, dilution, and substrate concentration on the net growth of rumen microorganisms was undertaken. The highest net growth value was obtained with a C/N ratio of 16.5 to 17.5, which is the ratio found for the ration fed to the animal. It was possible to increase net growth approximately threefold by using the proper dilution and fivefold by using the proper feed concentration.     

Structure and anomeric configuration of the 3,6-anhydro-osazone derivatives obtained from d-altro-2-heptulose phenylosazone

Dehydration of d-altro-2-heptulose phenylosazone with methanolic sulfuric acid afforded two 3,6-anhydro-osazone derivatives (2 and 3). Compound 3 was obtained as the preponderant isomer, with inversion at C-1 (C-3 of the starting osazone), and 2 was obtained without inversion. Refluxing of 3 with copper sulfate afforded the C-nucleoside analog, namely, 2-phenyl-4-β-d-ribofuranosyl-1,2,3-osotriazole (4). Acetylation of 4 afforded the tri-O-acetyl derivative 5. The anomeric configuration was determined by c.d. and n.m.r. spectroscopy. The mass spectra of compounds 2–5 are discussed.     

3-β-d-erythrofuranosyl-1-phenylpyrazolo[3,4-b]quinoxaline,a new C-nucleoside analog

Dehydration of the hydroxyalkyl chain of 1-phenyl-3-(d-arabino-tetritol-1-yl)pyrazolo[3,4-b]quinoxaline gave the C-nucleoside 3-β-d-erythrofuranosyl-1-phenyl-pyrazolo[3,4-b]quinoxaline (2) in 82% yield. The structure, and the configuration at the anomeric carbon atom, of 2 were elucidated by periodate oxidation, c.d. and n.m.r. spectroscopy, and mass spectrometry. N.m.r.-spectral and c.d. studies revealed that, due to the large size of the heterocyclic base, compound 2 is formed by inversion in the configuration or C-1 of the side chain. The mechanism of the dehydrative cyclization with inversion is discussed.     

Sensitive spectrofluorimetric determination of the prokinetic drug prucalopride succinate based on supramolecular aggregation approach with evaluation of method greenness: application to content uniformity test

The prokinetic drug, prucalopride (PCP) succinate, was determined using a new spectrofluorimetric approach with a highly sensitive, rapid, and simple procedure. The method exploited the enhancement of the inherent native fluorescence of PCP by micellar aggregation with sodium lauryl sulfate (SLS) as an anionic surfactant. Different factors that could affect the fluorescence intensity were carefully studied in order to achieve the maximal fluorescence signal. Measurement of the enhanced fluorescence was done at 354 nm after the excitation at 276 nm. The fluorescence intensity–concentration plot was rectilinear in the concentration range of 50–600 ng/ml with detection and quantitation limits of 13.9 and 42.1 ng/ml, respectively. The method underwent validation according to the International Council for Harmonisation criteria in order to assess its analytical performance, and promising results were achieved that proved the validity and reliability of the method. Furthermore, the method was employed effectively for the analysis of the cited drug in commercial pharmaceutical tablets.     

Species richness and phenology of vegetation along irrigation canals and drains in the Nile Delta,Egypt

This study evaluates the species richness, phenology and effect of environmental factors on the composition of canal and drain vegetation in the Nile Delta, Egypt. Altogether, 365 stands were sampled along the terraces, slopes, littoral zones and water zones of 28 canals and 10 drains. Smooth species compositional changes were found in the first three zones. The slope plant community has the highest total number of species and species richness and a medium value of species turnover. The water zone has the lowest values of these variables.The number of species with seedlings and vegetative plants had two peaks: one in winter and the second in summer, which was related to the contrasted behaviour of the winter and summer weeds. The number of species with vegetative and fruiting plants was relatively higher, while the number with dormant plants was relatively lower in the canal vegetation when compared to that of the drains. The number of species with vegetative, flowering and fruiting plants increased with the decrease of canal-drain width.