Serving two correlated queues with a synchronous server underexhaustive service discipline and nonzero switchover time

A system composed of two queues that accepts correlated inputs and receives services from a synchronous server is studied. An exhaustive service discipline is adopted in serving a queue. Nonzero switchover time for the server to change service from one queue to the other is assumed. A closed-form expression for mean waiting time is obtained. The validity of the analysis if verified using the results of a computer simulation     

TGF-beta 1 induces the cyclin-dependent kinase inhibitor p27Kip1 mRNA and protein in murine B cells

TGF-beta1 inhibits the cell cycle progression of many types of cells by arresting them in the G1 phase. This cell cycle arrest has been attributed to the regulatory effects of TGF-beta1 on both the levels and the activities of the G1 cyclins and their kinase partners. The activities of these kinases are negatively regulated by a number of proteins, such as p15INK4b, p21WAF1/Cip1, and p27Kip1, that physically associate with cyclins, cyclin-dependent kinases (Cdk), or cyclin-Cdk complexes. In epithelial cell lines, TGF-beta1 was previously shown to inhibit cell cycle progression through down-regulation of Cdk4 and/or up-regulation of p15INK4b and/or p21WAF1/Cip1. However, TGF-beta1 had little or no effect on the p27Kip1 mRNA and protein levels. In this report, we show that, in contrast to observations in epithelial cell lines, TGF-beta1 increased the p27Kip1 mRNA and protein levels in the murine B cell lines CH31 and WEHI231. This TGF-beta1-mediated induction of p27Kip1 also resulted in an increased association of p27Kip1 with Cdk2 and a decreased Cdk2 kinase activity. In contrast to epithelial cells, however, TGF-beta1 had little or no effect on the Cdk4 and p21WAF1/Cip1 protein levels in these B cells. Finally, although several studies suggested a direct role of p53 in TGF-beta1-mediated cell cycle arrest in epithelial cells, TGF-beta1 inhibited cell cycle progression in CH31 even in the absence of wild-type p53. Taken together, these results suggest that TGF-beta1 induces G1 arrest in B cells primarily through a p53-independent up-regulation of p27Kip1 protein.     

Flood hazards for nuclear power plants

Flooding hazards for nuclear power plants may be caused by various external geophysical events. In this paper the hydrologic hazards from flash floods, river floods and heavy rain at the plant site are considered. Depending on the mode of analysis, two types of hazard evaluation are identified: (a) design hazard which is the probability of flooding over an expected service period, and (b) operational hazard which deals with real-time forecasting of the probability of flooding of an incoming event. Hazard evaluation techniques using flood frequency analysis can only be used for type (a) design hazard. Evaluation techniques using rainfall-runoff simulation or multi-station correlation can be used for both types of hazard prediction.     

Sustained Release Suppository of Sodium Diclofenac: use of Water Absorbable Polymer

The investigation on the usefulness of water absorbable polymer (Poys® SA-20) for the preparation of sustained release suppository was performed. To prepare the sustained release suppository, sodium diclofenac solution is absorbed into the sphere polymer, and the particles of the polymer after dryness are suspended in the melted triglyceride suppository base, followed by solidification. The sustained release of sodium diclofenac from the suppository was confirmed by the in vitro release study with slow release of sodium diclofenac and by the in vivo absorption study in dogs with an avoidance of transient high plasma diclofenac concentration and a prolong of plasma diclofenac concentration.     

Guided tissue regeneration with use of β‐TCP/chitosan composite membrane

Guided tissue regeneration (GTR) membranes with bioabsorbable characteristics have been employed, in recent years, for periodontal procedures to deflect the growth of gingival tissues away from root surface. They provide an isolated space over regions with defective tissues and allow the relatively slow growing periodontal ligament fibroblasts to be repopulated over the root surface. In this study, we have employed chitosan and tricalcium phosphate (β‐TCP) as viable membrane materials and evaluated their roles in GTR applications. Three types of β‐TCP/chitosan membranes, weight ratio of β‐TCP/chitosan 65 : 35, 33 : 67, and 10 : 90, were prepared for three categories: the mechanical strength to create an effective space; the rapid rate to reach hydrolytic equilibrium in phosphate buffer solution; and the ease of clinical manipulations. Consequently, standardized, transosseous, and critical‐sized (cavity of 8 mm) skull defects were made in adult rabbits, and the defective regions were covered with the specifically prepared chitosan membranes. After 4 weeks of recovering, varying degrees of bone healing were observed beneath the β‐TCP/chitosan membranes in comparison to the control group. The β‐TCP/chitosan membranes covered regions showed a clear boundary space between connective tissues and bony tissues. Over all, good cell‐occlusion and beneficial osteogensis effects by these bioabsorbable materials toward the wound recovery were indicated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Production of two types of exopolysaccharide by Novosphingobium rosa

A bacterium, Ikeda-3, that was isolated from the wastewater of a winery was found to produce floating and precipitating exopolysaccharides (EPSs) when grown aerobically in a medium containing sucrose as the sole carbon source. The concentrations of floating and precipitating EPSs were approximately 2.7 g/l and 0.6 g/l, respectively, in a mini-jar fermentor after incubations of the bacterium at 15 degrees C for 5 d in a synthetic medium containing 1% sucrose, 0.01% CaCO3, 0.05% MgSO4, 0.05% K2HPO4, 0.0001% Na2MoO4, 0.05% peptone and 0.82% bicine. A component analysis of two types of EPS suggested that they represent a novel type of sphingan composed of glucose, rhamnose, mannose and mannuroic acid. Glucoronic acid, which is commonly found in sphingans, was absent. From physiological, biochemical and chemotaxonomic characterization, phylogenetic analysis and DNA-DNA relatedness, Ikeda-3 was identified as Novosphingobium rosa. To our knowledge the production of EPS by N. rosa is reported here for the first time.     

Open-Channel Capacity Determination Using Hydraulic Performance Graph

A method for determining the flow carrying capacity of a channel system, capable of accounting for the interacting backwater effect among channel reaches and incoming lateral flow, is presented here. The method makes use of hydraulic performance graphs—a new tool for dealing with open-channel-flow problems. The hydraulic performance graph summarizes all the backwater profile information for a channel reach. As an illustration, the method is applied to evaluate the channel capacities of a portion of Boneyard Creek in the city of Urbana, Ill. The example demonstrates that the channel flow capacity is a function of the exit water level, of which the maximum normal flow capacity and the absolute maximum carrying capacity are special cases.     

Extractive components of boiled–dried scallop adductor muscle and effect on the taste of soup after mixing with chicken leg meat

The extractive components of raw and boiled–dried scallop adductor muscle were examined. On a dry weight basis the levels of total free amino acids, total adenosine triphosphate (ATP) and related compounds, and betaines in the boiled–dried sample were lower than those in the raw muscle, which may have been due to the outflow of these compounds during boiling. Soup prepared from the boiled–dried scallop and chicken leg meat was assessed by sensory evaluation. This soup cooked with the scallop and chicken was stronger in sweetness, umami and body and rated higher in overall preference than the soup containing these ingredients after cooking separately. The inosine monophosphate (IMP) level in the former soup was 4.4 times higher than that in the latter. The adenosine monophosphate (AMP) deaminase (EC 3.5.4.6) activity in the crude extract from the chicken meat was 9.16 units l^?1, whereas no activity could be detected in the crude extract from the boiled–dried scallop. It is concluded that AMP, which was mainly derived from the boiled–dried scallop, was converted to IMP by AMP deaminase from the chicken meat during the preparation of the soup, resulting in an improvement in the taste. Copyright © 2004 Society of Chemical Industry     

Universal time provisioning in a distributed seismic-acoustic system for rock mass geomechanical monitoring

A structure of hardware-software universal time provisioning in a seismic-acoustic system for rock mass geomechanical monitoring is described. The structure was tested at a mine in the Chitinskaya Region. A measure of inaccuracy of universal time counting is analyzed and calculated.     

Real-time observation of coil-to-globule transition in thermosensitive poly(N-isopropylacrylamide) brushes by quartz crystal microbalance

Thermosensitive poly(N-isopropylacrylamide) (PNIPAm) brushes grafted on SiO₂-coated quartz crystal surface were prepared by the surface initiated radical polymerization. Using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), about 50 nm thickness of PNIPAm brushes were successfully formed. Quartz crystal microbalance with dissipation (QCM-D) is employed to investigate the collapse and swelling behavior of the PNIPAm brushes in water in real time. Both frequency and dissipation of PNIPAm layer were found to change gradually over the temperature range 15-50 °C, indicating that the brushes undergo a continuous transition. This continuous change is attributed to the nonuniformity and stretching of PNIPAm brushes as well as the cooperativity between collapse and dehydration transition.