Dicaf: a distributed architecture for intelligent transportation

The solution to increasing traffic congestion is not to simply build new roads. Instead, researchers hope to use technology to make more efficient use of the highway network that already exists. Key efforts to date have fallen into two categories. One set of studies has looked at the use of a centralized traffic management center that collects traffic congestion information at a single point and relays it to on-board computers in vehicles or directly to the drivers. Another set of studies has looked at systems that would prescribe the routes for vehicles. The authors describe their Dicaf (distributed scalable architecture for IVHS using a continuous-function congestion measure) system, which envisions a network of distributed, independent traffic management centers that provide congestion and other information to on-board navigation systems in the automobiles themselves. The navigation system uses that information to help drivers avoid slower traffic and thus find the fastest route home or anywhere     

Iodine-131-metaiodobenzylguanidine dosimetry in cancer therapy: risk versus benefit

In the treatment of neural crest tumors, such as pheochromocytoma, with[131I]MIBG, bone marrow toxicity limits the amount of administered activity and, thus, a therapeutically useful tumor dose. METHODS: We calculated tumor doses in a series of diagnostic studies with [123I]MIBG using accurate quantification of SPECT and planar scintigraphy. By extrapolating diagnostic results to therapeutic activities of [131I]MIBG, we could compare the results with whole-body doses from a series of therapies. RESULTS: The tumor dose was DT = 2.2 mGy MBq(-1) (median value of 27 measurements, range 0.04 < or = DT < or = 20 mGy MBq(-1) and the whole-body dose in a series of 16 patients undergoing 50 therapies was DWB = 0.12 +/- 0.04 mGy MBq(-1) (mean +/- s.d.). The therapeutic ratio varied between 130 to below 10 in some patients. CONCLUSION: The results were compared with published data. We found clearly skewed distribution of tumor doses, with a majority of tumors receiving only a few mGy per MBq administered activity. In some patients, however, doses did reach 20 mGy MBq(-1).     

DARYN-a distributed decision-making algorithm for railway networks:modeling and simulation

The state of the art in scheduling “point-to-point” trains in a railway network utilizes the principles of centralized decision-making. The major difficulty of this approach is that the execution time and the memory requirements increase nonlinearly as the system grows in size. The present paper introduces a new approach, “DARYN”, wherein the overall decision process is analyzed and distributed onto every natural entity of the system. In DARYN, the decision process for every train is executed by an on-board processor that negotiates, dynamically and progressively, for temporary ownership of the tracks with the respective station controlling the tracks, through explicit processor to processor communication primitives. This processor then computes its own route utilizing the results of its negotiation, its knowledge of the track layout of the entire system, and its evaluation of the cost function. Every station's decision process is also executed by a dedicated processor that, in addition, maintains absolute control over a given set of tracks and participates in the negotiation with the trains. Presently, DARYN utilizes a simple cost function. However, if one chooses to increase the complexity of the cost function, DARYN's advantage over the traditional approach increases due to its enormous available computational power. Given that the current microprocessors such as MC68030, MC88000, Intel 486, and Intel 860 are powerful yet relatively inexpensive, a network of concurrently executing processors may offer superior price-performance quotient over a single high performance computer     

Sesquiterpenoids of the drimane class from a sponge of the genus Dysidea

Ten sesquiterpenoids, including seven new ones, have been isolated from an undescribed sponge of the genus Dysidea. Compounds 1-8 are sesquiterpenoids of the drimane class, while 9 and 10 are 12-norsesquiterpenoids of the same structural class. The structures of novel compounds have been determined by combined spectroscopic methods. These compounds exhibited moderate antimicrobial and enzyme inhibitory (Na+/K(+)-ATPase and PLA2) activities.     

An atomic model of the outer layer of the bluetongue virus core derived from X-ray crystallography and electron cryomicroscopy

BACKGROUND: Bluetongue virus (BTV), which belongs to the Reoviridae family and orbivirus genus, is a non-enveloped, icosahedral, double-stranded RNA virus. Several protein layers enclose its genome; upon cell entry the outer layer is stripped away leaving a core, the surface of which is composed of VP7. The structure of the trimeric VP7 molecule has previously been determined using X-ray crystallography. The articulated VP7 subunit consists of two domains, one which is largely alpha-helical and the other, smaller domain, is a beta barrel with jelly-roll topology. The relative orientations of these two domains vary in different crystal forms. The structure of VP7 and the organizations of 780 subunits of this molecule in the core of virus is central to the assembly and function of BTV. RESULTS: A 23 A resolution map of the core, determined using electron cryomicroscopy (cryoEM) data, reveals that the 260 trimers of VP7 are organized on a rather precise T = 13 laevo icosahedral lattice, in accordance with the theory of quasi-equivalence. The VP7 layer occupies a shell that is between 260 A and 345 A from the centre of the core. Below this radius (230-260 A) lies the T = 1 layer of 120 molecules of VP3. By fitting the X-ray structure of an individual VP7 trimer onto the cryoEM BTV core structure, we have generated an atomic model of the VP7 layer of BTV. This demonstrates that one of the molecular structures seen in crystals of the isolated VP7 corresponds to the in vivo conformation of the molecule in the core. CONCLUSIONS: The beta-barrel domains of VP7 are external to the core and interact with protein in the outer layer of the mature virion. The lower, alpha-helical domains of VP7 interact with VP3 molecules which form the inner layer of the BTV core. Adjacent VP7 trimer-trimer interactions in the T = 13 layer are mediated principally through well-defined regions in the broader lower domains, to form a structure that conforms well with that expected from the theory of quasi-equivalence with no significant conformational changes within the individual trimers. The VP3 layer determines the particle size and forms a rather smooth surface upon which the two-dimensional lattice of VP7 trimers is laid down.     

Absolute stability of an implicit method based on third-order off-step discretization for the initial-value problem on a graded mesh

Engineering with Computers - We studied a new implicit method of order three based on two off-step points for the numerical solution of second-order nonlinear initial-value problems...     

Effects of temperature and blank holding force on biaxial forming behavior of aluminum sheet alloys

Biaxial forming behavior is investigated for three aluminum sheet alloys (Al 5182 containing 1% Mn (5182+Mn), Al 5754, and 6111-T4) using a heated die and punch in the warm forming temperature range of 200–350 °C. It is found that, while all three alloys exhibit significant improvement in their formability compared with that at room temperature, the non-heat-treatable alloys 5182 + Mn and 5754 give higher part depths than that of heat-treatable 6111-T4. The formability generally increases with decreasing BHP (BHP), but increasing the forming temperature and/or BHP minimizes the wrinkling tendency and improves the forming performance. The stretchability of the sheet alloys increase with increasing temperature and increasing BHP. For the alloys and forming conditions involved in the current study, the formability, measured in terms of part depth, comes mainly from the drawing of metal into the die cavity, although stretching effects do influence the overall forming behavior. The optimum formability is achieved by setting the die temperature 50 °C higher than the punch temperature to enhance the drawing component. Setting the die temperature higher than the punch temperature also improves the strain distribution in a part in such a manner that postpones necking and fracture by altering the location of greatest thinning.     

FORCED CONVECTIVE MASS TRANSFER IN ANNULI

Mass transfer in annuli has been critically examined for various flow situations. The overall mass transfer rate depends on the hydrodynamic regions prevailing in the annular channel as well as on its dimensions. Theoretically consistent correlations are proposed and recommended for both developed and developing boundary layers under laminar and turbulent flow conditions.     

Activation of rat liver cholesterol ester hydrolase by cAMP-dependent protein kinase and protein kinase C

Short term regulation of hepatic cholesterol ester hydrolase by reversible phosphorylation is described. Two different kinase systems seem to be involved in this regulation. The addition of ATP, cyclic AMP and Mg²⁺ to rat liver 104,000× g supernatant (S104) produced a 100–140% increase in cholesterol ester hydrolase activity. This stimulation was abolished when protein kinase inhibitor was added prior to the addition of ATP, cyclic AMP and Mg²⁺. Cholesterol ester hydrolase activity was also stimulated when calcium ions, phosphatidylserine, and diolein were added to S104 along with ATP and Mg²⁺. Diolein in this reaction could be substituted by phorbol 12-myristate 13-acetate. Preincubation of S104 with alkaline phosphatase resulted in a deactivation of cholesterol ester hydrolase. The addition of increasing concentrations of Mg²⁺ to S104 produced increasing inhibition of cholesterol ester hydrolase activity, and this effect was blocked by NaF. It is suggested that rat liver cholesterol ester hydrolase is activated by cyclic AMP dependent protein kinase and protein kinase C. Deactivation is accomplished by dephosphorylation catalyzed by a phosphoprotein phosphatase, dependent on Mg²⁺. This work was presented at the Twenty-Third Southeastern Regional Lipid Conference, held October 26–28, in Cashiers, North Carolina.