Article on heterodimeric geranyl(geranyl)diphosphate synthase from hop (Humulus lupulus) and the evolution of monoterpene biosynthesis.

This article discusses complexity and synchronization in decision making and information transmission.

In June 2004, the Demonstration Bulk Vitrification System (DBVS) was initiated with the intent to design, construct, and operate a full-scale bulk vitrification pilot-plant to treat low-activity tank waste from Hanford Tank 241-S-109. The DBVS facility uses In-Container Vitrification{trademark} (ICV{trademark}) at the core of the treatment process. The basic process steps combine liquid low-activity waste (LAW) and glassformers; dry the mixture; and then vitrify the mixture in a batch feed-while-melt process in a refractory lined steel container. Off-gases are processed through a state-of-the-art air pollution control system including sintered-metal filtration, thermal oxidation, acid gas scrubbing, and high-efficiency particulate air (HEPA) and high-efficiency gas adsorber (HEGA) filtration. Testing has focused on development and validation of the waste dryer, ICV, and sintered-metal filters (SMFs) equipment, operations enhancements, and glass formulation. With a parallel testing and design process, testing has allowed improvements to the DBVS equipment configuration and operating methodology, since its original inception. Design improvements include optimization of refractory panels in the ICV, simplifying glassformer addition equipment, increasing the number of waste feed chutes to the ICV, and adding capability for remote clean-out of piping, In addition, the U.S. Department of Energy (DOE) has provided an independent review of the entire DBVS …

We present fabrication and characterization of a membrane based on carbon nanotubes (CNTs) and parylene. Carbon nanotubes have shown orders of magnitude enhancement in gas and water permeability compared to estimates generated by conventional theories [1, 2]. Large area membranes that exhibit flux enhancement characteristics of carbon nanotubes may provide an economical solution to a variety of technologies including water desalination [3] and gas sequestration [4]. We report a novel method of making carbon nanotube-based, robust membranes with large areas. A vertically aligned dense carbon nanotube array is infiltrated with parylene. Parylene polymer creates a pinhole free transparent film by exhibiting high surface conformity and excellent crevice penetration. Using this moisture-, chemical- and solvent-resistant polymer creates carbon nanotube membranes that promise to exhibit high stability and biocompatibility. CNT membranes are formed by releasing a free-standing film that consists of parylene-infiltrated CNTs, followed by CNT uncapping on both sides of the composite material. Thus fabricated membranes show flexibility and ductility due to the parylene matrix material, as well as high permeability attributed to embedded carbon nanotubes. These membranes have a potential for applications that may require high flux, flexibility and durability.

A detailed chemical kinetic modeling approach is used to examine the phenomenon of suppression of sooting in diesel engines by addition of oxygenated hydrocarbon species to the fuel. This suppression, which has been observed experimentally for a few years, is explained kinetically as a reduction in concentrations of soot precursors present in the hot products of a fuel-rich diesel ignition zone when oxygenates are included. Oxygenates decrease the overall equivalence ratio of the igniting mixture, producing higher ignition temperatures and more radical species to consume more soot precursor species, leading to lower soot production. The kinetic model is also used to show how different oxygenates, ester structures in particular, can have different soot-suppression efficiencies due to differences in molecular structure of the oxygenated species.

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At the time of this writing, we have manufactured and delivered more than 25 multilayer dielectric diffraction gratings from 470-800 mm in long aperture for pulse compression on Petawatt-class,1-micron laser systems being built at government and university facilities in the U.S and elsewhere. We present statistics of diffraction efficiency and its spatial uniformity, diffracted wavefront, and laser damage results on witness gratings. We also discuss yield, failure modes, and manufacturing improvements necessary to improve upon the current state of the art.

Parton showers are widely used to generate fully exclusive final states needed to compare theoretical models to experimental observations. While, in general, parton showers give a good description of the experimental data, the precise functional form of the probability distribution underlying the event generation is generally not known. The reason is that realistic parton showers are required to conserve four-momentum at each vertex. In this paper we investigate in detail how four-momentum conservation is enforced in a standard parton shower and why this destroysthe analytic control of the probability distribution. We show how to modify a parton shower algorithm such that it conserves four-momentum at each vertex, but for which the full analytic form of the probability distribution is known. We then comment how this analytic control can be used to match matrix element calculations with parton showers, and to estimate effects of power corrections and other uncertainties in parton showers.

The {tau}{sup -} {yields} {pi}{sup -}{pi}{sup +}{pi}{sup -}{nu}{sub {tau}} and {tau}{sup -} {yields} {pi}{sup -}{pi}{sup -}{pi}{sup +}{eta}{nu}{sub {tau}} decays have been studied with the BABAR detector. Preliminary branching fractions on the two modes are presented. The {tau}{sup -} {yields} {pi}{sup -}{pi}{sup -}{pi}{sup +}{eta}{nu}{sub {tau}} mode is found to have a large contribution from the {tau}{sup -} {yields} {omega}{pi}{sup -}{nu}{sub {tau}} decay. The {tau}{sup -} {yields} {pi}{sup -}{pi}{sup -}{pi}{sup +}{eta}{nu}{sub {tau}} decay is studied using the {eta} {yields} {gamma}{gamma} mode and the {tau}{sup -} f{sub 1}(1285){pi}{sup -}{nu}{sub {tau}} decay is seen to be the primary source of these decays. A 90% confidence level upper limit is placed on the {tau}{sup -} {yields} {eta}{prime}(958){pi}{sup -}{nu}{sub {tau}} decay which proceeds through a second-class current and is expected to be forbidden in the limit of perfect isospin symmetry.

We study the smooth non-supersymmetric three-charge microstatesof Jejjala, Madden, Ross and Titchener using Kaluza-Klein reductions of the solutions to five and four dimensions. Our aim is to improve our understanding of the relation between these non-supersymmetric solutions and the well-studied supersymmetric cases. We find some surprising qualitative differences. In the five-dimensional description, the solution has orbifold fixed points which break supersymmetry locally, so the geometries cannot be thought of as made up of separate half-BPS centers. In the four-dimensional description, the two singularities in the geometry are connected by a conical singularity, which makes it impossible to treat them independently and assign unambiguous brane charges to these centers.

The authors present measurements of the CP-violation parameters S and C for the radiative decay B{sup 0} {yields} {eta}K{sub S}{sup 0}{gamma}; for B {yields} {eta}K{gamma} they also measure the branching fractions and for B{sup +} {yields} {eta}K{sup +}{gamma} the time-integrated charge asymmetry {Alpha}{sub ch}. The data, collected with the BABAR detector at the Stanford Linear Accelerator Center, represent 465 x 10{sup 6} B{bar B} pairs produced in e{sup +}e{sup -} annihilation. The results are S = -0.18{sub -0.46}{sup +0.49} {+-} 0.12, C = -0.32{sub -0.39}{sup +0.40} {+-} 0.07, {Beta}(B{sup 0} {yields} {eta}K{sup 0}{gamma}) = (7.1{sub -2.0}{sup +2.1} {+-} 0.4) x 10{sup -6}, {Beta}(B{sup +} {yields} {eta}K{sup +}{gamma}) = (7.7 {+-} 1.0 {+-} 0.4) x 10{sup -6}, and {Alpha}{sub ch} = (-9.0{sub -9.8}{sup +10.4} {+-} 1.4) x 10{sup -2}. The first error quoted is statistical and the second systematic.

The results from H.E.S.S. observations towards Westerlund 2 are presented. The detection of very-high-energy gamma-ray emission towards the young stellar cluster Westerlund 2 in the HII complex RCW49 by H.E.S.S. provides ample evidence that particle acceleration to extreme energies is associated with this region. A variety of possible emission scenarios is mentioned, ranging from high-energy gamma-ray production in the colliding wind zone of the massive Wolf-Rayet binary WR 20a, collective wind scenarios, diffusive shock acceleration at the boundaries of wind-blown bubbles in the stellar cluster, and outbreak phenomena from hot stellar winds into the interstellar medium. These scenarios are briefly compared to the characteristics of the associated new VHE gamma-ray source HESS J1023-575, and conclusions on the validity of the respective emission scenarios for high-energy gamma-ray production in the Westerlund 2 system are drawn.

Increasing evidence suggests that a combination of host genetics and the composition of the gut microbiota are important for development of Crohn's disease (CD). Our aim was to study identical twins with CD to determine microbial factors independently of host genetics. Fecal samples were studied from 10 monozygotic twin pairs with CD (discordant n=6, concordant n=4) and 8 healthy twin pairs. DNA was extracted, 16S rRNA genes were PCR amplified and T-RFLP fingerprints generated using general bacterial and Bacteroides group specific primers. The microbial communities were also profiled based on their % G+C contents. Bacteroides 16S rRNA genes were cloned and sequenced from a subset of the samples. The bacterial diversity in each sample and similarity indices between samples were estimated based on the T-RFLP data using a combination of statistical approaches. Healthy individuals had a significantly higher bacterial diversity compared to individuals with CD. The fecal microbial communities were more similar between healthy twins than between twins with CD, especially when these were discordant for the disease. The microbial community profiles of individuals with ileal CD were significantly different from healthy individuals and those with colonic CD. Also, CD individuals had a lower relative abundance of B. uniformis and …

The historical trend of increasing single CPU performancehas given way to roadmap of increasing core count. The challenge ofeffectively utilizing these multi-core chips is just starting to beexplored by vendors and application developers alike. In this study, wepresent some performance measurements of several complete scientificapplications on single and dual core Cray XT3 and XT4 systems with a viewto characterizing the effects of switching to multi-core chips. Weconsider effects within a node by using applications run at lowconcurrencies, and also effects on node-interconnect interaction usinghigher concurrency results. Finally, we construct a simple performancemodel based on the principle on-chip shared resource--memorybandwidth--and use this to predict the performance of the forthcomingquad-core system.

In heated tunnels such as those designated for emplacementof radioactive waste at Yucca Mountain, axial temperature gradients maycause natural convection processes that can significantly influence themoisture conditions in the tunnels and in the surrounding fractured rock.Large-scale convection cells would provide an effective mechanism foraxial vapor transport, driving moisture out of the formation away fromthe heated tunnel section into cool end sections (where no waste isemplaced). To study such processes, we have developed and applied anenhanced version of TOUGH2 (Pruess et al., 1999) adding a new module thatsolves for natural convection in open cavities. The new TOUGH2 simulatorsimultaneously handles (1) the flow and energy transport processes in thefractured rock; (2) the flow and energy transport processes in thecavity; and (3) the heat and mass exchange at the rock-cavity interface.The new module is applied to simulate the future thermal-hydrological(TH) conditions within and near a representative waste emplacement tunnelat Yucca Mountain. Particular focus is on the potential for condensationalong the emplacement section, a possible result of heat outputdifferences between individual waste packages.

We analyzed relative contributions to the cause andmechanism of injection-induced seismicity at The Geysers geothermalfield, California, using coupled thermal-hydrological-mechanicalmodeling. Our analysis shows that the most important cause forinjection-induced seismicity is injection-induced cooling and associatedthermal-elastic shrinkage that changes the stress state in such a waythat mechanical failure and seismicity can be induced. Specifically, thecooling shrinkage results in unloading and associated loss of shearstrength in critically shear-stressed fractures, which are thenreactivated. Thus, our analysis shows that cooling-induced shear slipalong fractures is the dominant mechanism of injection-induced seismicityat The Geysers.

Germanium, element No.32, was discovered in 1886 by Clemens Winkler. Its first broad application was in the form of point contact Schottky diodes for radar reception during WWII. The addition of a closely spaced second contact led to the first all-solid-state electronic amplifier device, the transistor. The relatively low bandgap, the lack of a stable oxide and large surface state densities relegated germanium to the number 2 position behind silicon. The discovery of the lithium drift process, which made possible the formation of p-i-n diodes with fully depletable i-regions several centimeters thick, led germanium to new prominence as the premier gamma-ray detector. The development of ultra-pure germanium yielded highly stable detectors which have remained unsurpassed in their performance. New acceptors and donors were discovered and the electrically active role of hydrogen was clearly established several years before similar findings in silicon. Lightly doped germanium has found applications as far infrared detectors and heavily Neutron Transmutation Doped (NTD) germanium is used in thermistor devices operating at a few milliKelvin. Recently germanium has been rediscovered by the silicon device community because of its superior electron and hole mobility and its ability to induce strains when alloyed with silicon. Germanium is again a …

The degree to which an individual organism maintains healthspan and lifespan is a function of complex interactions between genetic inheritance ('nature'), environment, including cultural inheritance (nurture) and stochastic events ('luck' or 'chance'). This task group will focus upon the role of chance because it is so poorly understood and because it appears to be of major importance in the determination of individual variations in healthspan and lifespan within species. The major factor determining variations in healthspan and lifespan between species is genetic inheritance. Broader aspects of cellular and molecular mechanisms of biological aging will also be considered, given their importance for understanding the cellular and molecular basis of successful aging. The task force will consider the cellular and molecular basis for nature, nurture and chance in healthspan and life span determination. On the basis of comparisons between identical and non-identical twins, geneticists have estimated that genes control no more than about a quarter of the inter-individual differences in lifespan (Herskind 1996). Twin studies of very old individuals, however, show substantially greater genetic contributions to Healthspan (McClearn 2004; Reed 2003). The environment clearly plays an important role in the length and the quality of life. Tobacco smoke, for example has the …

The SRS sludge that was to become a major fraction of Sludge Batch 5 (SB5) for the Defense Waste Processing Facility (DWPF) contained a large fraction of H-Modified PUREX (HM) sludge, containing a large fraction of aluminum compounds that could adversely impact the processing and increase the vitrified waste volume. It is beneficial to reduce the non-radioactive fraction of the sludge to minimize the number of glass waste canisters that must be sent to a Federal Repository. Removal of aluminum compounds, such as boehmite and gibbsite, from sludge can be performed with the addition of NaOH solution and heating the sludge for several days. Preparation of SB5 involved adding sodium hydroxide directly to the waste tank and heating the contents to a moderate temperature through slurry pump operation to remove a fraction of this aluminum. The Savannah River National Laboratory (SRNL) was tasked with demonstrating this process on actual tank waste sludge in our Shielded Cells Facility. This paper evaluates some of the impacts of aluminum dissolution on sludge washing and DWPF processing by comparing sludge processing with and without aluminum dissolution. It was necessary to demonstrate these steps to ensure that the aluminum removal process would not adversely impact …

This paper presents a novel method for determining the probability that a supernova candidate belongs to a known supernova type (such as Ia, Ibc, IIL, etc.), using its photometric information alone. It is validated with Monte Carlo, and both space- and ground-based data. We examine the application of the method to well-sampled as well as poorly sampled supernova light curves and investigate to what extent the best currently available supernova models can be used for typing supernova candidates. Central to the method is the assumption that a supernova candidate belongs to a group of objects that can be modeled; we therefore discuss possible ways of removing anomalous or less well understood events from the sample. This method is particularly advantageous for analyses where the purity of the supernova sample is of the essence, or for those where it is important to know the number of the supernova candidates of a certain type (e.g., in supernova rate studies).

The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radiofrequency (SCRF) accelerating cavities. The use of the SCRF technology was recommended by the International Technology Recommendation Panel (ITRP) in August 2004 [1], and shortly thereafter endorsed by the International Committee for Future Accelerators (ICFA). In an unprecedented milestone in high-energy physics, the many institutes around the world involved in linear collider R&D united in a common effort to produce a global design for the ILC. In November 2004, the 1st International Linear Collider Workshop was held at KEK, Tsukuba, Japan. The workshop was attended by some 200 accelerator physicists from around the world, and paved the way for the 2nd ILC Workshop in August 2005, held at Snowmass, Colorado, USA, where the ILC Global Design Effort (GDE) was officially formed. The GDE membership reflects the global nature of the collaboration, with accelerator experts from all three regions (Americas, Asia and Europe). The first major goal of the GDE was to define the basic parameters and layout of the machine--the Baseline Configuration. This was achieved at the first GDE meeting held at INFN, Frascati, Italy in December 2005 with the creation …

Countercurrent two-phase flow and “flooding” phenomena in light water reactor systems are being investigated experimentally and analytically to improve reactor safety of current and future reactors. The aspects that will be better clarified are the effects of condensation and tube inclination on flooding in large diameter tubes. The current project aims to improve the level of understanding of flooding mechanisms and to develop an analysis model for more accurate evaluations of flooding in the pressurizer surge line of a Pressurized Water Reactor (PWR). Interest in flooding has recently increased because Countercurrent Flow Limitation (CCFL) in the AP600 pressurizer surge line can affect the vessel refill rate following a small break LOCA and because analysis of hypothetical severe accidents with the current flooding models in reactor safety codes shows that these models represent the largest uncertainty in analysis of steam generator tube creep rupture. During a hypothetical station blackout without auxiliary feedwater recovery, should the hot leg become voided, the pressurizer liquid will drain to the hot leg and flooding may occur in the surge line. The flooding model heavily influences the pressurizer emptying rate and the potential for surge line structural failure due to overheating and creep rupture. The air-water …

We have started upgrading the control room programs for the injector at the Advanced Light Source (ALS). We chose to program in C* exclusively on the .NET Framework to create EPICS client programs on Windows Vista PCs. This paper reports the status of this upgrade project.

Liquid array technology has previously been used to show proof-of-principle of a multiplexed non structural protein serological assay to differentiate foot-and-mouth infected and vaccinated animals. The current multiplexed assay consists of synthetically produced peptide signatures 3A, 3B and 3D and recombinant protein signature 3ABC in combination with four controls. To determine diagnostic specificity of each signature in the multiplex, the assay was evaluated against a naive population (n = 104) and a vaccinated population (n = 94). Subsequently, the multiplexed assay was assessed using a panel of bovine sera generated by the World Reference Laboratory for foot-and-mouth disease in Pirbright, UK. This sera panel has been used to assess the performance of other singleplex ELISA-based non-structural protein antibody assays. The 3ABC signature in the multiplexed assay showed comparative performance to a commercially available non-structural protein 3ABC ELISA (Cedi test{reg_sign}) and additional information pertaining to the relative diagnostic sensitivity of each signature in the multiplex is acquired in one experiment. The encouraging results of the evaluation of the multiplexed assay against a panel of diagnostically relevant samples promotes further assay development and optimization to generate an assay for routine use in foot-and-mouth disease surveillance.