bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Single Target Is Sufficient To Account for the Biological Effects of the A-Factor Receptor Protein ofStreptomyces griseus
Authors: Kato Jun-ya , Miyahisa Ikuo , Mashiko Mari , Ohnishi Yasuo , Horinouchi Sueharu 
Published: March 2004

ABSTRACTIn the model of the A-factor (2-isocapryloyl-3R-hydroxymethyl-γ-butyrolactone) regulatory cascade inStreptomyces griseus, A-factor binds ArpA, the A-factor receptor protein, that has bound to theadpApromoter and dissociates it from the DNA, thus inducing the transcription ofadpA. AdpA switches on the transcription of a number of genes required for secondary metabolism and morphological differentiation, forming an AdpA regulon. Consistent with this model,arpAnull mutants produced streptomycin and a yellow pigment in larger amounts and formed aerial hyphae from an earlier growth stage than the wild-type strain. On the other hand, mutant MK2, expressing a mutant ArpA (Trp119Ala), neither produced secondary metabolites nor formed aerial hyphae, because this A-factor-insensitive mutant ArpA always bound to and repressed theadpApromoter due to the amino acid replacement of Trp-119 with Ala. Introduction ofadpAunder the control of a foreign promoter into mutant MK2 restored all of the phenotypes that we could observe, which suggests that the only significant target of ArpA isadpA. In contrast to other γ-butyrolactone regulatory systems, disruption ofarpAhad no effect on A-factor production, indicating that ArpA does not regulate A-factor biosynthesis. Instead, A-factor production was found to be repressed by AdpA in a two-step regulatory feedback loop.
Stochastic Processes Influence Stationary-Phase Decisions in
Bacillus subtilis
Authors: Maughan Heather , Nicholson Wayne L. 
Published: March 2004

ABSTRACT

It has recently been proposed that phenotypic variation in clonal populations of bacterial species results from intracellular “noise,” i.e., random fluctuations in levels of cellular molecules, which would be predicted to be insensitive to selective pressure. To test this notion, we propagated five populations of
Bacillus subtilis
for 5,000 generations with selection for one phenotype: the decision to sporulate. In support of the noise hypothesis, we report that none of the populations responded to selection by improving their efficiency of sporulation, indicating that intracellular noise is independent of heritable genotype.
Colonial Interventions on the Cultural Landscape of Central Sulawesi by "Ethical Policy": The Impact of the Dutch Rule in Palu and Kulawi Valley, 1905–1942
Authors: Kreisel Werner , Weber Robert , Faust Heiko 
Published: March 2004

The colonial conquest of Palu and Kulawi Valley in western Central Sulawesi, Indonesia, is characterised by the so-called "ethical policy", which was introduced to Dutch colonial policy at the beginning of the 20th century. An in-depth analysis of Dutch colonial sources, the
memories van overgave
, which have never been analysed in such detail on the subject of cultural geography, reveals that almost all facets of cultural landscape were influenced by the Dutch rule. These sources also disclose the ambiguous use of
ethical policy
by justifying or withdrawing colonial intervention in this area.
Optimal Observations for Variational Data Assimilation
Authors: Köhl Armin , Stammer Detlef 
Published: March 2004

Abstract
An important part of ocean state estimation is the design of an observing system that allows for the efficient study of climate related questions in the ocean. A solution to the design problem is presented here in terms of optimal observations that emerge as singular vectors of the modified data resolution matrix. The actual computation is feasible only for scalar quantities and in the limit of large observational errors. Identical twin experiments performed in the framework of a 1° North Atlantic primitive equation model demonstrate that such optimal observations, when applied to determining the heat transport across the Greenland–Scotland ridge, perform significantly better than traditional section data. On seasonal to interannual time scales, optimal observations are located primarily along the continental shelf and information about heat transport, wind stress, and stratification is being communicated through boundary waves and advective processes. On time scales of about 1 month, sea surface height observations appear to be more efficient in reconstructing the cross-ridge heat transport than hydrographic observations. Optimal observations also provide a tool for understanding changes of ocean state associated with anomalies of integral quantities such as meridional heat transport.
Direct Observations of Along-Isopycnal Upwelling and Diapycnal Velocity at a Shelfbreak Front*
Authors: Barth John A. , Hebert Dave , Dale Andrew C. , Ullman David S. 
Published: March 2004

Abstract
By mapping the three-dimensional density field while simultaneously tracking a subsurface, isopycnal float, direct observations of upwelling along a shelfbreak front were made on the southern flank of Georges Bank. The thermohaline and bio-optical fields were mapped using a towed undulating vehicle, and horizontal velocity was measured with a shipboard acoustic Doppler current profiler. A subsurface isopycnal float capable of measuring diapycnal flow past the float was acoustically tracked from the ship. The float was released near the foot of the shelfbreak front (95–100-m isobath) and moved 15 km seaward as it rose from 80 to 50 m along the sloping frontal isopycnals over a 2-day deployment. The float's average westward velocity was 0.09 m s−1, while a drifter drogued at 15 m released at the same location moved westward essentially alongfront at 0.18 m s−1. The float measured strong downward vertical velocities (in excess of 0.02 m s−1) associated with propagation of internal tidal solibores in the onbank direction from their formation near the shelf break. The float measured large upward vertical velocities (in excess of 0.001 m s−1 ≃ 100 m day−1) as the pycnocline rebounded adiabatically after the passage of the internal tide solibore. The directly measured mean along-isopycnal vertical velocity was 17.5 m day−1. Intense mixing events lasting up to 2 hours were observed in the shelfbreak front at the boundary between cold, fresh shelf water and warm, salty slope water. Diapycnal velocities of up to 3 × 10−3 m s−1 were measured, implying a diapycnal thermal diffusivity as large as 10−2 m2 s−1, indicative of strong mixing events in this coastal front.
The Origin, Pathway, and Destination of Niño-3 Water Estimated by a Simulated Passive Tracer and Its Adjoint
Authors: Fukumori Ichiro , Lee Tong , Cheng Benny , Menemenlis Dimitris 
Published: March 2004

Abstract
The nature of subtropical–tropical water mass exchange in the Pacific Ocean is investigated, focusing on the origin, pathway, and destination of water occupying the surface layer of the eastern equatorial Pacific Ocean (Niño-3 region; 5°S–5°N, 150°–90°W). Simulated passive tracers and their adjoint are employed to explicitly follow the circulation of specific water masses accounting for advective and diffusive effects and their time variabilities. The evolution of the forward passive tracer and adjoint passive tracer can be identified as describing where the tracer-tagged water mass goes and from where it comes, respectively. Over 10 years on average, water mass of the Niño-3 region can be traced back to eastern subtropical thermocline waters of the Northern (27%) and Southern Hemispheres (39%). The Niño-3 water subsequently returns to these subtropical latitudes in the upper ocean. In contrast to the hypothesized “subtropical cell,” however, this circulation is an open circuit with water returning to the western regions of the two hemispheres (subtropical gyres) and to the Indian Ocean, instead of returning to its origins. The representative transit time scale from the subtropics to the Tropics is 10–15 yr. Temporal variability causes the tropical circulation inferred from a time-mean state to differ significantly from the average circulation. In particular, stirring due to nonseasonal, intra-annual variability significantly enhances the transport magnitude of the so-called interior pathways relative to that of the circuitous low-latitude western boundary pathways. Such short-circuit in the subtropical–tropical exchange may help better to explain tracer distributions, such as the observed midbasin tritium maximum in the equatorial Pacific Ocean. Significant differences in circulation pathways are also identified that are associated with El Niño and La Niña events. The strength of the subtropical–tropical water mass exchange is estimated to have weakened during the 1990s.
The Meandering Path of a Drifter around the Western Alboran Gyre
Authors: García Lafuente Jesús , Delgado Javier 
Published: March 2004

Abstract
An accidentally released drifter in the eastern section of the Strait of Gibraltar, whose successive positions were tracked by the Argos surveillance system, was advected more than 170 km around the western Alboran gyre in the Alboran Sea of the western Mediterranean Sea during four days. The drifter trajectory along the gyre's periphery was wavelike around a hypothetical smoothed streamline, with a period of 35 h and an amplitude of approximately 2 km. Temperature observations confirm the wavelike nature of the trajectory. Neither tidal currents within the Alboran basin nor wind-related forcing are able to explain the observed path. The interaction of the incoming Atlantic jet and the western Alboran gyre at the place where they meet together with the existence of relative vorticity pulses of the Atlantic jet associated with tidal currents in the strait is put forward as a likely mechanism that generates short-scale eddies in which the drifter could have been trapped. The subsequent advection of such an eddy around the gyre would depict the observed wavelike trajectory.
SST Assimilation Experiments in a Tropical Pacific Ocean Model
Authors: Tang Youmin , Kleeman Richard , Moore Andrew M. 
Published: March 2004

Abstract
With a simple 3DVar assimilation algorithm, a new scheme of assimilating sea surface temperature (SST) observations is proposed in this paper. In this new scheme, the linear relation between any two neighboring depths was derived using singular value decomposition technique and then was applied to estimate the temperatures at deeper levels using the temperature analyses at shallower levels. The estimated temperatures were assimilated into an ocean model, and the procedure was run iteratively at each time step from the surface to a depth of 250 m. The oceanic analyses show that the new scheme can more effectively adjust oceanic thermal and dynamical fields and lead to a more realistic subsurface thermal structure when compared with the control run and another scheme that is usually used for SST assimilation. An ensemble of predictions for the Niño-3 region SST anomalies was performed to test the new scheme. It was found that the new scheme can improve fairly well ENSO prediction skills at all lead times, in particular for anomalous warm events, and for lead times of 4–7 months.
Preload-independent mechanisms contribute to increased stroke volume following large volume saline infusion in normal volunteers: a prospective interventional study
Authors: Kumar Anand , Anel Ramon , Bunnell Eugene , Zanotti Sergio , Habet Kalim , Haery Cameron , Marshall Stephanie , Cheang Mary , Neumann Alex , Ali Amjad , Kavinsky Clifford , Parrillo Joseph E 
Published: March 2004

Abstract
Introduction
Resuscitation with saline is a standard initial response to hypotension or shock of almost any cause. Saline resuscitation is thought to generate an increase in cardiac output through a preload-dependent (increased end-diastolic volume) augmentation of stroke volume. We sought to confirm this to be the mechanism by which high-volume saline administration (comparable to that used in resuscitation of shock) results in improved cardiac output in normal healthy volunteers.

Methods
Using a standardized protocol, 24 healthy male (group 1) and 12 healthy mixed sex (group 2) volunteers were infused with 3 l normal (0.9%) saline over 3 hours in a prospective interventional study. Individuals were studied at baseline and following volume infusion using volumetric echocardiography (group 1) or a combination of pulmonary artery catheterization and radionuclide cineangiography (group 2).

Results
Saline infusion resulted in minor effects on heart rate and arterial pressures. Stroke volume index increased significantly (by approximately 15–25%; P < 0.0001). Biventricular end-diastolic volumes were only inconsistently increased, whereas end-systolic volumes decreased almost uniformly. Decreased end-systolic volume contributed as much as 40–90% to the stroke volume index response. Indices of ventricular contractility including ejection fraction, ventricular stroke work and peak systolic pressure/end-systolic volume index ratio all increased significantly (minimum P < 0.01).

Conclusion
The increase in stroke volume associated with high-volume saline infusion into normal individuals is not only mediated by an increase in end-diastolic volume, as standard teaching suggests, but also involves a consistent and substantial decrease in end-systolic volumes and increases in basic indices of cardiac contractility. This phenomenon may be consistent with either an increase in biventricular contractility or a decrease in afterload.
Critical plane modelling of fatigue initiation under rolling and sliding contact
Authors: Šraml M , Flašker J , Potrč I 
Published: March 2004

Contact fatigue is a phenomenon of important practical significance for engineering applications involving localized contacts, such as gears, rail-wheel system and rolling bearings. The service lifetime of such components is related to damage, which results from the contact fatigue. The process in the material structure that causes this kind of failure is quite complicated. The aim of the present paper is to describe a contact fatigue initiation criterion, based on the critical plane approach for the general contact problem. On the basis of contact stress analysis with modified Hertzian boundary conditions, the loading cycle of characteristic material points in the contact area is determined. The Dang Van damage initiation criterion is based on the critical plane approach, which combines the largest allowable shearing and hydrostatic stresses (tensile and compressive), with an assumed elastic shakedown behaviour and it is used in this work. The material point of initial fatigue damage is then determined at the transition of the loading cycle stresses over the critical plane. The model assumed a homogeneous and elastic material model, without any imperfections or residual stresses, and elastic shakedown is considered. A proper determination of loading cycles and their characteristic values is of significance for contact fatigue initiation analysis. Finally, determination of the most critical material point on or under the contact surface and related number of loading cycles required for fatigue damage initiation is calculated with the strain-life (ε— N) method.
Magnetic Trapping of CocoreCoOshell Nanoparticles Produced by Gas Phase Reaction
Authors: Huh Seung H , Nakajima Atsushi 
Published: March 2004

Abstract
The magnetic trapping of gas phase CocoreCoOshell nanoparticles of ≈160 and 5–10 nm in diameter showed unique patterns of two-dimensional circular or oval distribution and one-dimensional aggregation, respectively, suggesting that granular nanowire can be formed when shell to core ratio is less than ≈0.38 at 0.5 T.
Novel Soluble and Thermally Stable Perylene Dye with Two [60] Fullerene Units
Authors: Hua Jianli , Meng Fanshun , Ding Fang , Tian He 
Published: March 2004

Abstract
A novel fullerene derivative in which perylene group is attached to two C60 through a pyrrolidine ring has been prepared and found to exhibit good solubility, high thermal stability and broad visible-light absorption with high coefficients, and photophysical studies shows that photo-induced energy transfer from the perylene moiety to C60.
Origins and development of biomedical engineering within chemical engineering
Authors: Peppas Nicholas A. , Langer Robert 
Published: March 2004

AbstractOver the past 45 years, the field of biomedical engineering has found a welcome home in academic chemical engineering departments and in companies working with artificial organs, medical devices, and pharmaceutical formulations. The contributions of chemical engineers to the definition and the growth of the field have been important and at times seminal. The development and early contributions in the biomedical field with special emphasis on the contributions of chemical engineers is examined. © 2004 American Institute of Chemical Engineers AIChE J, 50: 536–546, 2004
Effective and coupled thermal conductivities of isotropic open‐cellular foams
Authors: Fourie J. G. , Du Plessis J. P. 
Published: March 2004

AbstractThe effective and the coupled thermal conductivity of the solid microstructure of open‐cellular foams and an accompanying saturation fluid are defined in a conceptual representation of conductive heat transfer in a two‐phase system of which the phases are in a thermal nonequilibrium state. The effective and coupled thermal conductivities were determined from a close observation of the relationship between microscopic and macroscopic temperature distributions. Temperature distributions were obtained from the numerical solution of the three‐dimensional (3‐D) conduction equation in a representative geometrical model of the foam solid microstructure and the fluid pores. Empirical correlations are provided for the effective and coupled thermal conductivities in terms of the solid and the fluid thermal conductivity and foam porosity. Thermal radiation was not considered in the energy transfer process. © 2004 American Institute of Chemical Engineers AIChE J, 50: 547–556, 2004
Simulating aggregation and reaction: New Hounslow DPB and four‐parameter summary
Authors: Wynn E. J. W. 
Published: March 2004

AbstractA new formulation is developed of the popular Discretized Population Balance due to Hounslow and co‐workers. This new formulation is simpler and permits some variations in the method; three variations are put forward and tested. It also allows more flexibility in the choice of discretization, so that detail can be added at small sizes. The method is applied to the case of free‐molecular aggregation of SiO2 molecules in flames. The SiO2 is in equilibrium with SiO, which is assumed not to participate in aggregation; SiO2 molecules are, therefore, continuously created during aggregation. This source term complicates the resulting particle‐size distributions compared to the self‐preserving size distribution. Four parameters are used to summarize the PSDs, and their rates of change are found by approximations. This summarized model, a quasi‐self‐preserving size distribution, matches the detailed simulations very well. The cause of the stiffness of the differential equations is shown to be collisions between small and large particles. © 2004 American Institute of Chemical Engineers AIChE J, 50:578–588, 2004
Predicting packed‐bed breakthrough behavior from PFG NMR diffusion data
Authors: Rittig Frank , Farris Thomas S. , Zielinski John M. 
Published: March 2004

AbstractPulsed field gradient (PFG) NMR measurements have been conducted to measure self‐diffusion coefficients of gases within porous media. Analysis of these microscopic data with the use of a previously developed long‐range diffusion model has enabled us to accurately predict breakthrough curves for transport through packed‐bed adsorption columns, and the length of unused bed (LUB). This methodology enables the evaluation of mass‐transfer coefficients without the complications associated with transient sorption experiments, that is, heat effects, and thereby offers a reasonable alternative to conventional breakthrough experimentation for the evaluation of mass‐transfer coefficients, and LUB for large‐scale unit operations. 2004 American Institute of Chemical Engineers AIChE J, 50:589–595, 2004)
Detailed study of Tröger's base separation by SMB process
Authors: Mihlbachler Kathleen , Seidel‐Morgenstern Andreas , Guiochon Georges 
Published: March 2004

AbstractThis investigation of the separation of Tröger's base by the SMB process demonstrates: (1) the major importance of a proper modeling of the separation in order to determine the optimal operating conditions; (2) the need of an accurate modeling of the adsorption isotherms of the feed components. The adsorption of Tröger's base onto the stationary phase ChiralPak AD was successfully described by multilayer adsorption isotherm models. Due to the complexity of these models, the region of suitable operating parameters cannot be determined algebraically by the equilibrium theory. As an alternative, the equilibrium‐dispersive model, and a reliable numerical algorithm were used to scan a wide operating region, and to define this separation area. To verify the results of these calculations, the separation area was also experimentally detected by performing measurements of product purity and production rate for selected operating points. The combination of a UV detector and a polarimeter allows the accurate monitoring of the internal concentration profiles of both enantiomers. These profiles were compared to the profiles calculated using the multilayer adsorption isotherm models. In addition, the influence of the heterogeneity of the column set on the performance of the SMB process, is studied. Even under strongly nonlinear conditions, excellent agreements between calculated and experimental profiles were obtained. © 2004 American Institute of Chemical Engineers AIChE J, 50: 611–624, 2004
Experimental assessment of powerfeed chromatography
Authors: Zhang Ziyang , Morbidelli Massimo , Mazzotti Marco 
Published: March 2004

AbstractThe PowerFeed process is a modification of the simulated moving bed (SMB) technique, where the flow rates in the unit are allowed to change during a switching period following a predefined pattern. Through multiobjective optimization, using a genetic algorithm, it is shown that PowerFeed achieves better performances than SMB in several cases of interest for applications. Moreover, its experimental feasibility and effectiveness is assessed by running and comparing SMB and PowerFeed separations of the enantiomers of α‐ionone, on a cyclodextrin based chiral stationary phase. © 2004 American Institute of Chemical Engineers AIChE J, 50: 625–632, 2004
Interaction of separation and reactive stages on ETBE reactive distillation columns
Authors: Bisowarno Budi H. , Tian Yu‐Chu , Tadé Moses O. 
Published: March 2004

AbstractReactive distillation is a favorable alternative to conventional series of reactor‐distillation processes for ether productions. However, the design of such columns is complicated due to the interaction between vapor‐liquid equilibrium and reaction rates. There are conflicting reports on whether adding excessive separation stages degrade the column performance. A comparison is made of several designs of single and double feed reactive distillation columns for ETBE production to investigate the effects of separation and reaction stages on the overall performance. The explanations are presented using simulation results, whose mathematical models are written in the Aspen Plus environment. The results confirm that a conservative approach by adding extra separation and reaction stages can be applied to reactive distillation design. However, output multiplicity may be observed for longer column and should be considered in the early design phase. © 2004 American Institute of Chemical Engineers AIChE J, 50: 646–653, 2004