bluuebunny/crossref_metadata_2025 huggingface dataset:
Concentration fluctuations and collective properties in mixed liquid systems: Rayleigh-Brillouin spectra of tert-butyl alcohol/ 2,2′-dimethylbutane liquid mixture
Authors: Cataliotti Rosario Sergio , Palombo Francesca , Paolantoni Marco , Sassi Poala , Raudino Antonio
Published: January 2007

Rayleigh-Brillouin spectra have been measured in a range of temperatures and compositions of t-butyl alcohol/2,2′-dimethylbutane liquid mixture. The mixture mole fraction has been varied from pure alkane (xTBA=0) to pure alcohol (xTBA=1) at temperatures between 283 and 323K. In the same composition and temperature ranges the authors also executed measurements of mass density, shear viscosity, and refractive index. From light scattering spectra the authors have extracted the hypersound velocities and adiabatic compressibilities and evaluated their excess values. Moreover, the authors attempted to evaluate the isothermal (40°C) Landau-Placzek ratios at various mole fractions, but these values proved to be subject to significant errors due to great uncertainty in the central component intensity measurements. Thus, in discussing the results, this latter quantity was considered only from a qualitative point of view. These results highlight a nonideal behavior of the studied liquid mixture with a probable azeotropic composition around xTBA=0.7 due to formation of small clusters of hydrogen-bonded alcohol tetramers that are completely surrounded by solvent molecules and analogous or smaller clusters. These clusters, shaped as inverse micelles, offer their hydrophobic moiety towards the molecules that constitute the solvation shell, resulting in a low polarity solution structure that minimizes the solute-solvent interactions. Differences in thermal and compositional behavior of excess molar volumes and adiabatic compressibilities have been interpreted by attributing different weights to the solute-solvent interaction forces and to the hydrogen bond connectivity effects.
Computation of the effect of neutral collisions on ion current to a floating sphere in a stationary plasma
Authors: Hutchinson I. H. , Patacchini L.
Published: February 2007

The Specialized-Coordinate Electrostatic Particle and Thermals in Cell (SCEPTIC) code [I. H. Hutchinson, Plasma Physics and Controlled Fusion 45, 1447 (2003)] is used to compute the ion flux to a floating sphere in a stationary plasma, including the effects of charge-exchange collisions with neutrals. The results agree well with the available prior calculations at very low and very high collisionality thus validating the code and those prior calculations. In addition, SCEPTIC provides quantitative results at intermediate collisionalities where no analytic theory is available. Reasonable agreement in the floating potential is found there with some prior numerical results. For λDe much greater than the sphere radius, enhancements of the ion collection above the orbital motion limited value by factors as high as 5 occur, enough to exceed slightly the radial motion value, but only over a restricted range of collisionality. An explicit analytic fit to SCEPTIC’s results is provided for easy evaluation over the entire range of collisionality.
Construction of a dilution refrigerator cooled scanning force microscope
Authors: Gildemeister A. E. , Ihn T. , Barengo C. , Studerus P. , Ensslin K.
Published: February 2007

We present a scanning force microscope that operates in a dilution refrigerator at temperatures of about 100 mK. We use tuning fork sensors for scanning gate experiments on mesoscopic semiconductor nanostructures. Slip-stick motors allow sample coarse-positioning at base temperature. The construction, thermal anchoring, and a procedure to optimize the settings of the phase-locked loop that we use for sensor control are discussed in detail. We present low-temperature topographic and scanning gate images as examples of successful operation.
Polymorph selection during the crystallization of Yukawa systems
Authors: Desgranges Caroline , Delhommelle Jerome
Published: February 2007

Using molecular-dynamics simulations, we study the crystallization of supercooled liquids of charge-stabilized colloidal suspensions, modeled by the Yukawa (screened-Coulomb) potential. By modifying the value of the screening parameter λ, we are able to invert the stability of the body-centered cubic (bcc) and face-centered cubic (fcc) polymorphs and study the crystal nucleation and growth in the domain of stability of each polymorph. We show that the crystallization mechanism strongly depends on the value of λ. When bcc is the stable polymorph (λ=3), the crystallization mechanism is straightforward. Both kinetics and thermodynamics favor the formation of the bcc particles and polymorph selection takes place early during the nucleation step. When fcc is the stable polymorph (λ=10), the molecular mechanism is much more complex. First, kinetics favor the formation of bcc particles during the nucleation step. The growth of the post-critical nucleus proceeds through the successive cross-nucleation of the stable fcc polymorph on the metastable hcp polymorph as well as of the hcp polymorph on the fcc polymorph. As a result, polymorph selection occurs much later, i.e., during the growth step, than for λ=3. We then extend our findings established in the case of homogeneous crystal nucleation to a situation of practical interest, i.e., when a seed of the stable polymorph is used. We demonstrate that the growth from the (111) face of a perfect fcc crystal into the melt proceeds through the same mechanisms.
On detailed balance and reversibility of semi-Markov processes and single-molecule enzyme kinetics
Authors: Wang Hongyun , Qian Hong
Published: February 2007

Semi-Markov processes have found increasing applications in modeling the kinetics of single enzyme molecules. Detailed balance is a widely accepted condition for Markov models of closed chemical systems and well known to be equivalent to the reversibility of a stationary Markov process. We show that for a semi-Markov process detailed balance is only a necessary condition, but not sufficient, for its time reversibility. The statistical independence between the transition direction and the sojourn time is also necessary. We show that the direction-time independence naturally arises from the exit problem of Markov models for enzyme kinetics with detailed balance. Detailed balance and the direction-time independence together are equivalent to the time reversibility of a stationary semi-Markov process. Applications of the present theory to single-molecule enzymology are also presented.
Efficient blue lasers based on gain structure optimizing of vertical-external-cavity surface-emitting laser with second harmonic generation
Authors: Kim Jun-Youn , Cho Soohaeng , Lim Seong-Jin , Yoo Jaeryung , Kim Gi Bum , Kim Ki-Sung , Lee Junho , Lee Sang-Moon , Kim Taek , Park Yongjo
Published: February 2007

We report on the demonstration of highly efficient blue lasers based on intracavity frequency doubling vertical-external-cavity surface-emitting lasers (VECSELs). By optimizing the number of InGaAs quantum wells and employing Al0.3Ga0.7As carrier blocking layers in resonant periodic gain structures, we observed the pump-power-limited output power of 4.5W at 920nm for an InGaAs∕GaAs quantum well VECSEL. With a frequency doubling LiB3O5 crystal inside the cavity, 1.9W continuous-wave 460nm blue output was demonstrated. Power conversion efficiencies (=output power∕pump input power) of 22.5% and 9.5% are realized for λ∼920nm and λ∼460nm, respectively.
Effects of layer patterns on magnetic and other properties of single and multilayered Fe–C films
Authors: Kwok S. C. H. , McKenzie D. R. , Bilek M. M. M. , Chu Paul K.
Published: February 2007

The structure and magnetic properties of Fe–C films synthesized using dual cathodes and coaxial cathodes in a filtered high current pulsed cathodic vacuum arc were studied. By altering the experimental parameters such as the trigger sequence, period, and pulse length, a series of single and multilayered Fe–C films were deposited. X-ray photoelectron spectroscopy and cross-sectional transmission electron microscopy were utilized to study the composition and microstructure of the films. The magnetic properties were studied using a superconducting quantum interference device magnetometer. The hysteresis loops show that the magnetic properties are controlled by the pattern of the layers and Fe concentration in the films. The reduction in the coercive field when Fe layers are mixed with ta-C layers is a key result and confirms that magnetically soft materials can be created by the multilayer method. The relationship between the magnetic properties and the structure of single and multilayered Fe–C films is discussed.
Raman scattering spectra of coupled LO-phonon-plasmon modes in N-In codoped p-type ZnO thin films
Authors: Kong J. F. , Chen H. , Ye H. B. , Shen W. Z. , Zhao J. L. , Li X. M.
Published: January 2007

The authors report on a detailed Raman study of N–In codoped p-type ZnO thin films with the hole density ranging from 7.30×1016to2.30×1018cm−3. In addition to the identification of E2(high) modes of ZnO and InN at ∼434 and ∼488cm−1, respectively, clear coupled longitudinal-optical phonon-hole-plasmon modes have been observed. A theoretical analysis combining the deformation potential and electro-optic mechanisms can well reproduce the line shapes of the coupled modes, where the yielded hole densities and mobilities are found to be in good agreement with the data from Hall measurements.
A self-consistent hybrid model of a dual frequency sheath: Ion energy and angular distributions
Authors: Dai Zhong-Ling , Xu Xiang , Wang You-Nian
Published: February 2007

This paper presents a self-consistent hybrid model including the fluid model which can describe the characteristics of collisional sheaths driven by dual radio-frequency (DF) sources and Monte Carlo (MC) method which can determine the ion energy and angular distributions incident onto the dual rf powered electrode. The charge-exchange collisions between ions and neutrals are included in the MC model in which a self-consistent instantaneous electric field obtained from the fluid model is adopted. In the simulation, the driven method we used is either the current-driven method or the voltage-driven method. In the current-driven method, the rf current sources are assumed to apply to an electrode, which is the so-called the equivalent circuit model and is used to self-consistently determine the relationship between the instantaneous sheath potential and the sheath thickness. In the voltage-driven method, however, the rf voltage sources are assumed to apply to an electrode. The dual rf sheath potential, sheath thickness, ion flux, ion energy distributions (IEDs), and ion angular distributions (IADs) are calculated for different parameters. The numerical solutions show that some external parameters such as the bias frequency and power of the lower-frequency source as well as gas pressure are crucial for determining the structure of collisional dual rf sheaths and the IEDs. The shapes of the IADs, however, are determined mainly by the gas pressure. Furthermore, it is found that the results from the different driven methods behave in the same way although there are some differences in some quantities.
Stabilization of the quasi-interchange mode in tokamaks by circulating energetic ions
Authors: Kolesnichenko Ya. I. , Lutsenko V. V. , Marchenko V. S. , White R. B.
Published: February 2007

The influence of the circulating energetic ions on the quasi-interchange (QI) mode in tokamak plasmas with a wide shearless core and the central safety factor close to unity is considered. It is found that these ions tend to stabilize the QI mode in the case of co-injection and balanced injection, whereas the influence of counter-circulating ions is typically destabilizing because of finite-orbit-width effects. Specific examples relevant to tokamaks with large and small aspect ratio of the torus are considered.
Linear and nonlinear evolution of azimuthal clumping instabilities in a Z-pinch wire array
Authors: Tang Wilkin , Strickler T. S. , Lau Y. Y. , Gilgenbach R. M. , Zier Jacob , Gomez M. R. , Yu Edmund , Garasi Chris , Cuneo M. E. , Mehlhorn T. A.
Published: February 2007

This paper presents an analytic theory on the linear and nonlinear evolution of the most unstable azimuthal clumping mode, known as the pi-mode, in a discrete wire array. In the pi-mode, neighboring wires of the array pair-up as a result of the mutual attraction of the wires which carry current in the same direction. The analytic solution displays two regimes, where the collective interactions of all wires dominate, versus where the interaction of the neighboring, single wire dominates. This solution was corroborated by two vastly different numerical codes which were used to simulate arrays with both high wire numbers (up to 600) and low wire number (8). All solutions show that azimuthal clumping of discrete wires occurs before appreciable radial motion of the wires. Thus, absence of azimuthal clumping of wires in comparison with the wires’ radial motion may imply substantial lack of wire currents. While the present theory and simulations have ignored the plasma corona and axial variations, it is argued that their effects, and the complete account of the three-dimensional feature of the pi-mode, together with a scaling study of the wire number, may be expediently simulated by using only one single wire in an annular wedge with a reflection condition imposed on the wedge’s boundary.
Terahertz electrical and optical characteristics of double-walled carbon nanotubes and their comparison with single-walled carbon nanotubes
Authors: Maeng Inhee , Kang Chul , Oh Seung Jae , Son Joo-Hiuk , An Kay Hyeok , Lee Young Hee
Published: February 2007

The electrical and optical properties of double-walled carbon nanotubes (DWNTs) have been characterized and compared with those of single-walled carbon nanotubes (SWNTs) utilizing terahertz time-domain spectroscopy. The power absorption and the complex refractive indices of DWNTs are smaller than those of SWNTs. The conductivity of DWNTs was also observed to be smaller. The experimental results have been fitted with the Bruggman effective medium approximations, which has yielded the transport parameters of DWNTs such as plasma frequency, damping rate, etc.
Digital microfluidics: Droplet based logic gates
Authors: Cheow Lih Feng , Yobas Levent , Kwong Dim-Lee
Published: February 2007

The authors present microfluidic logic gates based on two-phase flows at low Reynold’s number. The presence and the absence of a dispersed phase liquid (slug) in a continuous phase liquid represent 1 and 0, respectively. The working principle of these devices is based on the change in hydrodynamic resistance for a channel containing droplets. Logical operations including AND, OR, and NOT are demonstrated, and may pave the way for microfludic system automation and computation.
Large intrinsic effect of axial strain on the critical current of high-temperature superconductors for electric power applications
Authors: van der Laan D. C. , Ekin J. W.
Published: February 2007

A remarkably large reversible reduction in the critical current of “second generation” high-temperature superconductors for electric power applications has been measured with a new technique over a wide range of mechanical strain. The effect amounts to a 40% reduction in critical current at 1% compressive strain in self-magnetic field, and is symmetric for compressive and tensile strains. The intrinsic effect is measured in highly aligned multigranular YBa2Cu3O7−d coated conductors made by different processes, including superconductors with nanoscale pinning centers. This effect and its magnitude are expected to have a significant impact on power applications and provide a useful new parameter for probing the fundamental nature of current transport in high-temperature superconductors.
Multipactor discharge in a dielectric-loaded accelerating structure
Authors: Wu L. , Ang L. K.
Published: February 2007

This paper presents a Monte-Carlo model to explain the multipactor discharge and its high-power absorption in a dielectric-loaded accelerating (DLA) structure reported recently [J. G. Power et al., Phys. Rev. Lett. 92, 164801 (2004)]. Susceptibility diagrams are constructed. Dynamic calculations for beam loading and its power absorption by the multipactor discharge are performed. It is found that the fraction of power absorbed by multipactor discharge at saturation is much larger than the case of a simple rf window, and it is sensitive to the incident power, which confirms the prior experimental results. This enhanced power absorption is due to the fact that the length of a DLA structure is much larger than the radius of the structure. A resonant condition of a maximum growth region has also been determined numerically and analytically. The difference between the resonant condition and saturation (due to beam loading) is clarified.
Critical diameter for III-V nanowires grown on lattice-mismatched substrates
Authors: Chuang Linus C. , Moewe Michael , Chase Chris , Kobayashi Nobuhiko P. , Chang-Hasnain Connie , Crankshaw Shanna
Published: January 2007

The authors report the experimental observation of a critical diameter (CD) of III-V compound semiconductor epitaxial nanowires (NWs) grown on lattice-mismatched substrates using Au-catalyzed vapor-liquid-solid growth. The CD is found to be inversely proportional to the lattice mismatch. NWs with well-aligned orientation are synthesized with catalysts smaller than the CD. Well-aligned InP NWs grown on a Si substrate exhibit a record low photoluminescence linewidth (5.1meV) and a large blueshift (173meV) from the InP band gap energy due to quantization. Well-aligned InAs NWs grown on a Si substrate are also demonstrated.
Thermal tweezers for surface manipulation with nanoscale resolution
Authors: Gramotnev Dmitri K. , Mason Daniel R. , Gramotnev Galina , Rasmussen Anthony J.
Published: February 2007

In this letter, the authors demonstrate that random Brownian forces can be used for effective trapping and manipulation of nanoparticles and molecules on surfaces in the presence of strong temperature modulation. Substantial (approximately two orders of magnitude) increase in the modulation of particle concentration (trapping efficiency) compared to thermophoresis in a bulk medium is predicted and explained by a periodic potential of interaction between a particle/molecule and the crystalline surface. As a result, a new nanofabrication and manipulation technique for creating optically induced complex surface structures with nanoscale resolution below tens of nanometers is proposed and developed.
Excitation dynamics of the 1.54μm emission in Er doped GaN synthesized by metal organic chemical vapor deposition
Authors: Ugolini C. , Nepal N. , Lin J. Y. , Jiang H. X. , Zavada J. M.
Published: February 2007

The authors report on the excitation dynamics of the photoluminescence (PL) emission of Er doped GaN thin films synthesized by metal organic chemical vapor deposition. Using the frequency tripled output from a Ti:sapphire laser, the authors obtained PL spectra covering the ultraviolet (UV) to the infrared regions. In the UV, a dominant band edge emission at 3.23eV was observed at room temperature; this is redshifted by 0.19eV from the band edge emission of undoped GaN. An activation energy of 191meV was obtained from the thermal quenching of the integrated intensity of the 1.54μm emission line. This value coincides with the redshift of the band edge emission and is assigned to the ErGa-VN complex level.
Nucleophilic Displacements of Imidazoles. II. Displacements of Halogen by S-Nucleophiles and Displacements of Mesyl Groups Activated by Nitro; Oxidation of Imidazolethiols
Authors: Kulkarni S , Grimmett MR
Published: February 2007

In basic medium arylthiols displace bromo and iodo groups activated by nitro substituents in 5(4)-halo-4(5)- nitroimidazoles . The bromo compounds are slightly more reactive than the iodo analogues. Substituents at C5 are more readily displaced than those at C4. Methylsulfonyl groups, similarly activated by an adjacent nitro substituent, are displaced by a variety of nucleophiles. The imidazolethiol products are readily oxidized to the sulfones.
Genome dynamics in a natural archaeal population
Authors: Allen Eric E. , Tyson Gene W. , Whitaker Rachel J. , Detter John C. , Richardson Paul M. , Banfield Jillian F.
Published: February 2007

Evolutionary processes that give rise to, and limit, diversification within strain populations can be deduced from the form and distribution of genomic heterogeneity. The extent of genomic change that distinguishes the acidophilic archaeon
Ferroplasma acidarmanus
fer1 from an environmental population of the same species from the same site, fer1(env), was determined by comparing the 1.94-megabase (Mb) genome sequence of the isolate with that reconstructed from 8 Mb of environmental sequence data. The fer1(env) composite sequence sampled ≈92% of the isolate genome. Environmental sequence data were also analyzed to reveal genomic heterogeneity within the coexisting, coevolving fer1(env) population. Analyses revealed that transposase movement and the insertion and loss of blocks of novel genes of probable phage origin occur rapidly enough to give rise to heterogeneity in gene content within the local population. Because the environmental DNA was derived from many closely related individuals, it was possible to quantify gene sequence variability within the population. All but a few gene variants show evidence of strong purifying selection. Based on the small number of distinct sequence types and their distribution, we infer that the population is undergoing frequent genetic recombination, resulting in a mosaic genome pool that is shaped by selection. The larger genetic potential of the population relative to individuals within it and the combinatorial process that results in many closely related genome types may provide the basis for adaptation to environmental fluctuations.
Glomerulocystic kidney disease in mice with a targeted inactivation of
Wwtr1
Authors: Hossain Zakir , Ali Safiah Mohamed , Ko Hui Ling , Xu Jianliang , Ng Chee Peng , Guo Ke , Qi Zeng , Ponniah Sathivel , Hong Wanjin , Hunziker Walter
Published: January 2007

Wwtr1 is a widely expressed 14-3-3-binding protein that regulates the activity of several transcription factors involved in development and disease. To elucidate the physiological role of Wwtr1, we generated
Wwtr1
−/−
mice by homologous recombination. Surprisingly, although Wwtr1 is known to regulate the activity of Cbfa1, a transcription factor important for bone development,
Wwtr1
−/−
mice show only minor skeletal defects. However,
Wwtr1
−/−
animals present with renal cysts that lead to end-stage renal disease. Cysts predominantly originate from the dilation of Bowman's spaces and atrophy of glomerular tufts, reminiscent of glomerulocystic kidney disease in humans. A smaller fraction of cysts is derived from tubules, in particular the collecting duct (CD). The corticomedullary accumulation of cysts also shows similarities with nephronophthisis. Cells lining the cysts carry fewer and shorter cilia and the expression of several genes associated with glomerulocystic kidney disease (
Ofd1
and
Tsc1
) or encoding proteins involved in cilia structure and/or function (
Tg737
,
Kif3a
, and
Dctn5
) is decreased in
Wwtr1
−/−
kidneys. The loss of cilia integrity and the down-regulation of
Dctn5
,
Kif3a
,
Pkhd1
and
Ofd1
mRNA expression can be recapitulated in a renal CD epithelial cell line, mIMCD3, by reducing Wwtr1 protein levels using siRNA. Thus, Wwtr1 is critical for the integrity of renal cilia and its absence in mice leads to the development of renal cysts, indicating that
Wwtr1
may represent a candidate gene for polycystic kidney disease in humans.
Site-specific DNA transesterification catalyzed by a restriction enzyme
Authors: Sasnauskas Giedrius , Connolly Bernard A. , Halford Stephen E. , Siksnys Virginijus
Published: February 2007

Most restriction endonucleases use Mg
2+
to hydrolyze phosphodiester bonds at specific DNA sites. We show here that BfiI, a metal-independent restriction enzyme from the phospholipase D superfamily, catalyzes both DNA hydrolysis and transesterification reactions at its recognition site. In the presence of alcohols such as ethanol or glycerol, it attaches the alcohol covalently to the 5′ terminus of the cleaved DNA. Under certain conditions, the terminal 3′-OH of one DNA strand can attack the target phosphodiester bond in the other strand to create a DNA hairpin. Transesterification reactions on DNA with phosphorothioate linkages at the target bond proceed with retention of stereoconfiguration at the phosphorus, indicating, uniquely for a restriction enzyme, a two-step mechanism. We propose that BfiI first makes a covalent enzyme–DNA intermediate, and then it resolves it by a nucleophilic attack of water or an alcohol, to yield hydrolysis or transesterification products, respectively.
mRNA maturation by two-step trans-splicing/polyadenylation processing in trypanosomes
Authors: Jäger Adriana V. , De Gaudenzi Javier G. , Cassola Alejandro , D'Orso Iván , Frasch Alberto C.
Published: February 2007

Trypanosomes are unique eukaryotic cells, in that they virtually lack mechanisms to control gene expression at the transcriptional level. These microorganisms mostly control protein synthesis by posttranscriptional regulation processes, like mRNA stabilization and degradation. Transcription in these cells is polycistronic. Tens to hundreds of protein-coding genes of unrelated function are arrayed in long clusters on the same DNA strand. Polycistrons are cotranscriptionally processed by trans-splicing at the 5′ end and polyadenylation at the 3′ end, generating monocistronic units ready for degradation or translation. In this work, we show that some trans-splicing/polyadenylation sites may be skipped during normal polycistronic processing. As a consequence, dicistronic units or monocistronic transcripts having long 3′ UTRs are produced. Interestingly, these unspliced transcripts can be processed into mature mRNAs by the conventional trans-splicing/polyadenylation events leading to translation. To our knowledge, this is a previously undescribed mRNA maturation by trans-splicing uncoupled from transcription. We identified an RNA-recognition motif-type protein, homologous to the mammalian polypyrimidine tract-binding protein, interacting with one of the partially processed RNAs analyzed here that might be involved in exon skipping. We propose that splice-site skipping might be part of a posttranscriptional mechanism to regulate gene expression in trypanosomes, through the generation of premature nontranslatable RNA molecules.
Actions and uses of 1-methylcyclopropene (1-MCP).
Authors: Watkins C. B.
Published: January 2007

A new strategy for controlling ethylene production and thus ethylene-mediated responses during ripening and senescence of fruit, and senescence of ornamental products and vegetative tissues, has emerged with the discovery and commercialization of the inhibitor of ethylene perception, 1-methylcyclopropene (1-MCP). 1-MCP competes with ethylene for binding sites, preventing ethylene perception and subsequent effects of ethylene on metabolism. 1-MCP is available commercially, and registration for use on various horticultural products has occurred worldwide. 1-MCP has been investigated widely as a tool to maintain quality of horticultural products, as well as to investigate the role of ethylene in the physiological and biochemical responses of these products during ripening and senescence. The effects of 1-MCP on ethylene-mediated responses depend on its concentration and the exposure period, product type and post-treatment manipulations such as storage regime and storage period. Research has led to the identification of strengths and limitations in applying 1-MCP-based technology at the commercial level.
Keratinase technology: from feather degradation and feed additive,to prion destruction.
Authors: Shih J. C. H. , Wang J. J.
Published: January 2007

A bio-process called thermophilic anaerobic digestion that converts poultry waste into biogas energy was developed in our laboratory. During operation, feathers in the waste were completely degraded. This observation prompted a series of studies that have led to new technology and commercial developments. A feather-degrading bacterium was discovered and isolated. An enzyme called keratinase capable of hydrolysing the feather protein keratin was purified. The gene encoding this enzyme was isolated and sequenced. Genetic modification enabled the over expression of the gene in the parent strain as well as in other
Bacillus
strains. Scale-up fermentation, first in 150 l and then in 50 kl fermentors, made the mass production of the enzyme possible. Subsequently, in application research, keratinase was shown to partially hydrolyse feathers and convert them into a digestible feed protein. When supplemented as a feed additive on standard diet, the enzyme promoted chicken growth by improving dietary protein digestibility. Ifcommercially developed, keratinase can lower feed cost, increase poultry meat yield, and upgrade the utilization of less digestible protein feedstuffs. From an environmental point of view, keratinase has the potential to reduce waste nitrogen excretion by farm animals. More recently, keratinase was found to be able to degrade prion protein that is believed to cause transmissible spongiform encephalopathies (TSE) including mad cow disease, sheep scrapie, deer chronic wasting disease and human CreutzfeldtJakob disease. This discovery indicated the potential use of keratinase in a new enzymatic process to destroy prion protein and possibly prevent TSE, in a cost-effective and environmentally friendly manner. To test and to develop the enzymatic process, a prion-like surrogate protein (PSP) has been developed as a safe bio-marker. The combination of keratinase and PSP can provide a useful toolbox for TSE prevention. Based on the keratinase platform technology and its applications, BioResource International (BRI), a biotechnology company, was founded to serve the poultry and animal industries.
A high-end ICT-based information system architecture for effective analysis and usage of agricultural data in decision-making.
Authors: Mangalampalli A. , Shinde C. V. , Chakravarth R.
Published: January 2007

Various agriculture-based information communication technologies (ICTs) are used throughout the world with various degrees of sophistication. In this paper, we have analysed these ICTs and then suggested a holistic and comprehensive prototypic agricultural ICT model. Until now, agricultural information systems have been implemented using various technologies such as radio, internet radio, internet, wide area networks (WANs) and mobile phones in various developed and developing countries. We have examined examples of such ICTs implemented in developing countries including India, Bangladesh, Sri Lanka, African and Latin American countries. Some developed countries, such as Australia, have nationwide ICTs spanning a spectrum of fields, including agriculture. After examining these ICTs, we have developed an agricultural information system which uses many software and hardware technologies and spans the whole agricultural system, from the scientists and policy-makers to the common farmers and from the national level to the village level. This information system makes use of the latest technologies, including DSS, intelligent systems, data-mining, data warehousing, and high-performance computer (HPC) grids. This paper details seminal research done in the development of an architectural model for implementing a high-end agricultural information system. This architectural model can be used to develop a more detailed framework.
Forages as protein sources for pigs in the tropics.
Authors: Preston T. R.
Published: January 2007

The decreasing availability and increasing prices of petroleum-based fuels is already having an impact on availability of feed resources. Research to develop alternative sources of live stock feed thus has a high priority. It is also important that the alternative feed resources can be grown on the farm as this will: (i) directly benefit the poorer farmers, who do not have cash resources topurchase supplements from outside the farm; and (ii) be an active response to the need to localize the farming system as a defence against the decreasing availability and increasing prices of petroleum-based fuels which will drive up the costs of transport. This review has shown that the leaves from shrubs such as cassava and mulberry, from vegetables such as sweet potato (SP) and cocoyam, together with water plants such as duckweed (
Lemna
spp.) and water spinach (
Ipomoea aquatica
), can be used successfully in diets for pigs to replace at least half the protein usually supplied as soyabean and fish meals (FMs). It is strongly recommended that future research in this area should be with basal diets that are low in protein and in cell wall constituents, as this will facilitate: (i) increasing the percentage of forage protein in the diet; and (ii) decreasing the overall protein level in the diet in accordance with the concept of the 'ideal protein.
Effects of no-tillage on soil structure.
Authors: Weisskopf P. , Anken T.
Published: January 2007

When used over several years, no-tillage (NT) increases spatial differentiation of soils vertically and horizontally by altering the structure and composition of the top layer. This results from dispensing with mechanical loosening and mechanical mixing in of organic matter. Associated with this are direct changes in soil structural properties such as macropore volume and pore continuity, as well as alterations in the quantity and quality of soil organic matter (SOM). An established NT-system increasingly affects the structure of deeper soil layers by promoting the continuity of biopores such as earthworm and root channels. This may lead to flow systems with high specific water conductivity and enhanced preferential flow, thereby influencing transport processes through the soil profile. In NT-soils, areas with high transport potential occur often simultaneously to zones with unfavourable structural properties and low air-filled porosity, which may offer, under certain site conditions, difficulties for the exchange of gases. Compared to mechanical tillage, NT normally increases the stability of aggregates and of the bulk soil, thereby improving trafficability and resistance to erosion, but also increasing penetration resistance for root development. Significant interactions exist between aggregate formation and SOM turnover of soils, which is of interest regarding C sequestration. By using NT, the importance of natural regeneration processes in maintaining a good soil structure increases. Therefore, organising the changeover from mechanical tillage to NT as well as the control of the compaction risk in an established NT-system needs special attention in order to ensure the sustainability of a NT-system.
Evaluation of an Alcohol-Based Surgical Hand Disinfectant Containing a Synergistic Combination of Farnesol and Benzethonium Chloride for Immediate and Persistent Activity Against Resident Hand Flora of Volunteers and With a Novel In Vitro Pig Skin Model
Authors: Shintre Milind S. , Gaonkar Trupti A. , Modak Shanta M.
Published: February 2007

Objective.

To evaluate the immediate, persistent and sustained in vivo activity of an alcohol-based surgical hand disinfectant, consisting of a zinc gel and a preservative system containing a synergistic combination of farnesol and benzethonium chloride (ZBF disinfectant), and to develop a pig skin model for in vitro evaluation of the immediate and persistent efficacy of alcohol-based surgical hand disinfectants against resident hand flora.

Design.

The in vivo immediate, persistent, and sustained activity of ZBF disinfectant was evaluated using human volunteers and the “glove-juice” method described in the US Food and Drug Administration's Tentative Final Monograph (FDA-TFM) for Healthcare Antiseptic Products. A novel in vitro pig skin model was developed to compare the immediate and persistent activity of alcohol-based surgical hand disinfectants against resident flora usingStaphylococcus epidermidisas the test organism. Four alcohol-based surgical hand disinfectants were evaluated using this model.

Results.

The results for the ZBF disinfectant exceed the FDA-TFM criteria for immediate, persistent, and sustained activity required for surgical hand disinfectants. The reduction factors for the 4 hand disinfectants obtained using the pig skin model show good agreement with the log10reductions in concentrations of hand flora obtained using human volunteers to test for immediate and persistent activity.

Conclusion.

The ZBF disinfectant we evaluated met the FDA-TFM criteria for surgical hand disinfectants. The immediate and persistent efficacy of the surgical hand disinfectants evaluated with the novel pig skin model described in this study shows good agreement with the results obtained in vivo.
Risk Factors forClostridium difficileInfection in a Hepatology Ward
Authors: Vanjak Dominique , Girault Guillaume , Branger Catherine , Rufat Pierre , Valla Dominique-Charles , Fantin Bruno
Published: February 2007

During 2001,Clostridium difficileinfection was observed in 23 patients hospitalized in a hepatology ward (attack rate, 0.9%). Since strain typing ruled out a clonal dissemination, we performed a case-control study. In addition to antibiotic use as a risk factor, theC. difficileinfection rate was higher among patients with autoimmune hepatitis (P< .01).
Subnuclear Localization and Dynamics of the Pre-mRNA 3′ End Processing Factor Mammalian Cleavage Factor I 68-kDa Subunit
Authors: Cardinale Stefano , Cisterna Barbara , Bonetti Paolo , Aringhieri Chiara , Biggiogera Marco , Barabino Silvia M.L.
Published: February 2007

Mammalian cleavage factor I (CF Im) is an essential factor that is required for the first step in pre-mRNA 3′ end processing. Here, we characterize CF Im68 subnuclear distribution and mobility. Fluorescence microscopy reveals that in addition to paraspeckles CF Im68 accumulates in structures that partially overlap with nuclear speckles. Analysis of synchronized cells shows that CF Im68 distribution in speckles and paraspeckles varies during the cell cycle. At an ultrastructural level, CF Im68 is associated with perichromatin fibrils, the sites of active transcription, and concentrates in interchromatin granules-associated zones. We show that CFIm68 colocalizes with bromouridine, RNA polymerase II, and the splicing factor SC35. On inhibition of transcription, endogenous CF Im68 no longer associates with perichromatin fibrils, but it can still be detected in interchromatin granules-associated zones. These observations support the idea that not only splicing but also 3′ end processing occurs cotranscriptionally. Finally, fluorescence recovery after photobleaching analysis reveals that the CF Im68 fraction associated with paraspeckles moves at a rate similar to the more dispersed molecules in the nucleoplasm, demonstrating the dynamic nature of this compartment. These findings suggest that paraspeckles are a functional compartment involved in RNA metabolism in the cell nucleus.
Hindu Temples in the New World System, 1640–1800
Authors: Waghorne Joanne Punzo
Published: February 2007

The attention given to the 19th century in contemporary postcolonial studies skews the discussion of modernization and religion toward ideologies not materialities. Refocusing on the late 16th century during the rise of the new world system shows Hindu temples emerging as key institutions in the resettlement and reorientation of Indian Hindus in the new global economy. The key players were classic bourgeoisie, a multi-caste group of “merchants” in the East India Company. These merchants resembled their British counterparts in their rising status within their respective societies at home and their shared society in “Blacktown”. Through the use of archival maps, a reconfiguration of the Hindus temples becomes visible within this new urban space. The pattern of deities and the basic styles of their new homes — eclectic and duplicated — prefigure contemporary temples built within Chennai but also abroad in this new era of geo-culture and geo-economics (Wallerstein).
The Book of Job in Medieval Jewish Philosophy
Authors: Eisen Robert
Published: February 2007

This book analyzes the history of the interpretation of the book of Job by medieval Jewish exegetes. The scholarship on medieval Jewish thought has focused largely on the systematic philosophical aspects of this literature. The author, however, is concerned with exegesis qua exegesis. He offers a close examination of commentaries on Job written by six major thinkers: Saadiah Gaon (882-942, Egypt and Babylon), Moses Maimonides (1138-1204, Spain and Egypt), Samuel ibn Tibbon (1160-1230, Provence), Zerahiah Hen (13th Century, Barcelona and Rome), Levi Gersonides (1288-1344, Provence), and Simeon ben Zeham Duran (1361-1444, Majorca and Algiers). Saadiah and Maimonides wrote in Arabic, the other four in Hebrew. The author looks at the relationship between the commentaries and their antecedent sources as well as their relationship to the broader context of medieval Jewish thought. He also provides an overview of the questions the commentators confronted about the historicity, national origin, and “Jewishness” of the text. He argues that the commentaries on Job are linked in a coherent and evolving tradition of interpretation and he identifies various views of providence as the central concern of them all.
Samuel ibn Tibbon
Authors: Eisen Robert
Published: February 2007

Despite the many difficulties presented by Ibn Tibbon’s discussion of the Book of Job in Ma’amar Yikkavu ha-Mayim, it is argued that with a close reading, his interpretation of Job can be deciphered. This will be the primary challenge of this chapter. Much of the chapter will be spent attempting to discern what Ibn Tibbon says about Job. Only when this is accomplished will it be possible to analyze his reading in accordance with the three interfaces that are the focus of this study. Ibn Tibbon has emerged here as an interpreter who sees himself primarily as a commentator on Maimonides, rather than as an independent thinker in his own right. It is also evident that despite his dependence on Maimonides, Ibn Tibbon sometimes comes up with insights that are very much his own. These include a host of ideas that supplement, but also at times overturn, Maimonides’ understanding of the biblical text. Most significant is Ibn Tibbon’s notion that the Book of Job is designed to teach that providence is to be equated with immortality and that there is no individual providence in this world that guards physical well-being.
Eternity
Authors: Adamson Peter
Published: February 2007

This chapter surveys the Greek background in Plato’s Timaeus, Aristotle’s Physics and De Caelo, and the dispute between late Greek thinkers, especially Proclus and Philoponus. Against this background, al-Kindī’s arguments that only God can be eternal and that creation must be finite in time as well as space are explored. It is suggested that al-Kindī’s interest in this topic can be explained in terms of the contemporary ’Abbāsid dogma that the Koran is not eternal, but created.
Entrepreneurship as Creative Construction
Authors: Audretsch David B. , Keilbach Max C. , Lehmann Erik E.
Published: February 2007

This chapter presents a synthesis of the discussions in the preceding chapters. It argues that entrepreneurship makes a unique contribution to economic growth by permeating the knowledge filter and commercializing ideas that would otherwise remain uncommercialized. Entrepreneurial opportunities are not at all exogenous, or given, in the Knowledge Spillover Theory of Entrepreneurship. Rather, they are endogenously generated by the extent of investments in new knowledge. Thus, a context rich in knowledge will generate more entrepreneurial opportunities than a context with impoverished knowledge.
Religion and Global Civil Society
Authors: Berger Peter
Published: February 2007

This essay examines the very idea of civil society in an era of globalization and questions religions’ relationship to it. Using Pentecostalism, resurgent Islam, and Catholicism as examples, it argues that religion fosters both civility and incivility, though it tends to lead to the latter more often.
The Politics of Religion and the Morality of Globalization
Authors: An‐Na'im Abdullahi A.
Published: February 2007

This essay questions whether economic globalization and global civil society work against each other or in concert. Examining Islamic fundamentalism, Hindu nationalism, and Liberation Theology, it proposes that there are possibilities of synergy and mediation between the two: the exclusivity and intolerance of some religious communities can be moderated by the impact of economic globalization, while economic globalization’s inattentiveness to social justice can be redressed through the moral guidance of religion.
Globalizing Civil Religion and Public Theology
Authors: Tipton Steven M.
Published: February 2007

This essay analyzes the intersections of civil religion and public theology with globalization. It explores two possibilities: the development of an international world-polity and the persistence of state-centric nationalism. It concludes with a call to recognize distinctive yet overlapping forms of civil religion emerging around the globe, and to acknowledge the ongoing argument among diverse public theologies about the proper shape of the world to come.
Intercultural Understanding in a Community School
Authors: Bounds Elizabeth M. , Patterson Bobbi
Published: February 2007

This essay examines the International Community School (ICS), a public charter school near Atlanta, Georgia, that brings refugee, immigrant, and local U.S. children together in one educational environment as a microcosmic global civic space in an emerging global civil society. It focuses on the local and particular instantiations of globalization, paying special attention to the role of religions.
Religious Transnationalism
Authors: Hoeber Rudolph Susanne
Published: February 2007

This essay inquires into the implications of the “fading of the state” for religion and the prospects for a universal “ecumene” in the expanding transnational space. Assuming that forms of polity and forms of religiosity have an effect on each other, one should expect the thinning of state boundaries and the expansion of transnational political, social, and economic institutions and epistemes to affect forms of religiosity and the formulation of religious goals. Excluding the likelihood that the new transnationalism would favor resurrecting a universal church, this essay concludes by exploring the prospects and challenges posed by ecumenism or “universal religiosity” grounded in the principle that there is truth in all religions.
Tradable Permits in Principle and Practice
Authors: Tietenberg Tom
Published: February 2007

This essay reviews data on tradable permit systems in various contexts, including air pollution regulation, water supply, fisheries management, grazing rights allocation, water quality, and wetlands preservation. These programs are evaluated against three criteria: implementation feasibility, environmental effectiveness, and economic effectiveness. The analysis makes clear that the particular characteristics of these different regimes affect the evaluation of their performance. Beyond reporting substantive results for each program, the essay offers insight into the methodological difficulties of ex post evaluations generally. For example, not all studies define economic efficiency or environmental effectiveness in the same way, and studies vary in their choice of comparative benchmark or counterfactual, which can significantly affect results. Ex post evaluations differ as well in terms of both scope (i.e., which outcomes are considered exogenous and which endogenous) and timing (i.e., the point in the life of the program when the evaluation is done). All of these choices can influence the resulting interpretations.