bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ionic liquid‐mediated selective extraction of lignin from wood leading to enhanced enzymatic cellulose hydrolysis
Authors: Lee Sang Hyun , Doherty Thomas V. , Linhardt Robert J. , Dordick Jonathan S. 
Published: October 2008

AbstractLignocellulose represents a key sustainable source of biomass for transformation into biofuels and bio‐based products. Unfortunately, lignocellulosic biomass is highly recalcitrant to biotransformation, both microbial and enzymatic, which limits its use and prevents economically viable conversion into value‐added products. As a result, effective pretreatment strategies are necessary, which invariably involves high energy processing or results in the degradation of key components of lignocellulose. In this work, the ionic liquid, 1‐ethyl‐3‐methylimidazolium acetate ([Emim][CH3COO]), was used as a pretreatment solvent to extract lignin from wood flour. The cellulose in the pretreated wood flour becomes far less crystalline without undergoing solubilization. When 40% of the lignin was removed, the cellulose crystallinity index dropped below 45, resulting in >90% of the cellulose in wood flour to be hydrolyzed by Trichoderma viride cellulase. [Emim] [CH3COO] was easily reused, thereby resulting in a highly concentrated solution of chemically unmodified lignin, which may serve as a valuable source of a polyaromatic material as a value‐added product. Biotechnol. Bioeng. 2009;102: 1368–1376. © 2008 Wiley Periodicals, Inc.
Analysis of metabolic pathways and fluxes in a newly discovered thermophilic and ethanol‐tolerant Geobacillus strain
Authors: Tang Yinjie J. , Sapra Rajat , Joyner Dominique , Hazen Terry C. , Myers Samuel , Reichmuth David , Blanch Harvey , Keasling Jay D. 
Published: October 2008

AbstractA recently discovered thermophilic bacterium, Geobacillus thermoglucosidasius M10EXG, ferments a range of C5 (e.g., xylose) and C6 sugars (e.g., glucose) and is tolerant to high ethanol concentrations (10%, v/v). We have investigated the central metabolism of this bacterium using both in vitro enzyme assays and 13C‐based flux analysis to provide insights into the physiological properties of this extremophile and explore its metabolism for bio‐ethanol or other bioprocess applications. Our findings show that glucose metabolism in G. thermoglucosidasius M10EXG proceeds via glycolysis, the pentose phosphate pathway, and the TCA cycle; the Entner–Doudoroff pathway and transhydrogenase activity were not detected. Anaplerotic reactions (including the glyoxylate shunt, pyruvate carboxylase, and phosphoenolpyruvate carboxykinase) were active, but fluxes through those pathways could not be accurately determined using amino acid labeling. When growth conditions were switched from aerobic to micro‐aerobic conditions, fluxes (based on a normalized glucose uptake rate of 100 units (g DCW)−1 h−1) through the TCA cycle and oxidative pentose phosphate pathway were reduced from 64 ± 3 to 25 ± 2 and from 30 ± 2 to 19 ± 2, respectively. The carbon flux under micro‐aerobic growth was directed to ethanol, L‐lactate (>99% optical purity), acetate, and formate. Under fully anerobic conditions, G. thermoglucosidasius M10EXG used a mixed acid fermentation process and exhibited a maximum ethanol yield of 0.38 ± 0.07 mol mol−1 glucose. In silico flux balance modeling demonstrates that lactate and acetate production from G. thermoglucosidasius M10EXG reduces the maximum ethanol yield by approximately threefold, thus indicating that both pathways should be modified to maximize ethanol production. Biotechnol. Bioeng. 2009;102: 1377–1386. © 2008 Wiley Periodicals, Inc.
A stoichiometric model of Acidithiobacillus ferrooxidans ATCC 23270 for metabolic flux analysis
Authors: Hold C. , Andrews B.A. , Asenjo J.A. 
Published: October 2008

AbstractA stoichiometric model of Acidithiobacillus ferrooxidans based on the sequenced genome from strain ATCC 23270 is derived and parameterized using genome/pathway databases. The model describes the main aspects of catabolism and anabolism. By the construction and utilization of the mathematical determination of the network, metabolic flux analysis is performed for such a bacterium for the first time and results are successfully verified by comparison to literature values. This first metabolic model of A. ferrooxidans is able to simulate the main aspects of metabolism and will be useful for further investigation and improvement of bioleaching procedures. Biotechnol. Bioeng. 2009;102: 1448–1459. © 2008 Wiley Periodicals, Inc.
Bulky Pyrazolate‐Based Compartmental Ligand Scaffolds: Encapsulation of an Edge‐Sharing Cu6O2 Bitetrahedral Core
Authors: Sachse Anna , Noël Gilles , Dechert Sebastian , Demeshko Serhiy , Honecker Andreas , Alfonsov Alexei , Kataev Vladislav , Meyer Franc 
Published: October 2008

AbstractUpon reaction with Cu(OAc)2·H2O, pyrazole‐based ligands with two appended imine chelate arms in the 3‐ and 5‐positions of the pyrazole and bulky substituents at the imine‐N yield Cu6 complexes [L2Cu6(μ‐OAc)6(μ4‐O)2] (1a,b). They feature an unusual {Cu6(μ4‐O)2}‐bitetrahedral core, only the second example of this structural motif. ESI mass spectrometric and UV/Vis data confirm that the Cu6 complexes stay intact in solution, and magnetic and high‐field EPR measurements reveal an S = 0 ground state with the first excited triplet at ΔE ≈ 95 cm–1. Although the new hexanuclear systems are too complex for deriving all individual exchange constants from powder susceptibility data, a rough idea of the complete energy level spectrum could be obtained.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
A probabilistic evaluation of wind turbine fatigue design rules
Authors: Veldkamp Dick 
Published: October 2008

AbstractIn wind turbine fatigue design, it is customary to use the partial safety factor approach: loads are inflated by some factor, while material fatigue strength is decreased in calculations. Values for partial factors used originally come from civil engineering standards for utility buildings and bridges, and it is not clear that they are optimal for wind turbines. In the paper, an inventory of important stochastic parameters influencing fatigue loads is given, and their estimated distributions are presented. With this information, failure probabilities due to fatigue are determined, as well as the relative importance of the stochastic parameters for total uncertainty. Using a simple cost model, economically optimal failure probabilities and partial factors are derived. The main conclusion of the presented work is that uncertainties in material fatigue properties and life prediction methods dominate total uncertainty, and hence determine the required partial factors. Copyright © 2008 John Wiley & Sons, Ltd.
Isolated singular points in the theory of algebraic surfaces
Authors: Babbage D. W. 
Published: November 2008

If F(x0, x1, x2, x3) = 0 is the equation of a surface in space of three dimensions which has an ordinary isolated s-ple point O, then by means of the substitutionswhere Φ0 = 0, Φ1 = 0, …, Φr = 0 are the equations of r + 1 linearly independent surfaces passing simply through O, F is transformed into a surface F′ in [r], on which to the point O of F there corresponds a simple curve γ. The points of γ arise from the points of F in the first neighbourhood of O, and in this simple case the genus of γ is ½ (s − 1) (s − 2). In the study of properties which are common to all members of an infinite family of birationally equivalent surfaces no distinction is made between O and γ, O being regarded as a curve which has become infinitesimal on the particular surface of the family in question.
On the interaction of colloidal particles V. nature of repulsion between particles in dilute sols
Authors: Levine S. 
Published: November 2008

AbstractAn extension is proposed to the theory of Verwey and Overbeek on the force between two colloidal particles in a dilute sol. The effect of the Coulomb interaction of the ions in the dispersion medium is considered. It is shown that this contributes an additional repulsion term to the mutual free energy of the two particles. This correction term behaves as an inverse power and is the predominant effect at large separations, although it is a second-order effect at small separations. For parallel plates, this power is the fourth, and for two spheres, the sixth. A tentative calculation shows that, at least for thin plates and low electrolyte concentrations, our new repulsion will outweigh the attractive London-van der Waals force considered by Verwey and Overbeek, and more recently by Casimir and Polder, when the plates are far apart.
A problem in dynamic plasticity: the enlargement of a circular hole in a flat sheet
Authors: Freiberger W. 
Published: November 2008

AbstractThe problem discussed in this paper is the enlargement of a circular hole in a flat sheet of which the material is in plastic flow under constant shear stress; inertia terms are taken into account in the equilibrium equations so as to permit the occurrence of high velocities.The treatment is in some ways analogous to that of problems in one-dimensional compressible gas flow. The characteristic equations are seen to represent straight lines under certain initial conditions; this facilitates consideration of any mode of enlargement; in particular, uniform acceleration is illustrated by numerical calculations. There appears a circular shock-front, i.e. a discontinuity in thickness and velocity moving ahead of the hole. The initial conditions for the existence of this ‘simple wave' solution involve a singularity at the centre of the plate.In general, the characteristic curves will not be straight lines and the equations are best solved step by step. Their characteristic form is well adapted to such a process; this is outlined for the interesting case of initial enlargement with uniform velocity followed by expansion under constant acceleration.Curves illustrate some of the general results.
Contributions à l'étude des effets des extrémités dans un générateur à électrodes finies
Authors: DragoŞ Lazar 
Published: November 2008

AbstractThe paper studies the motion of an electro-conductive non-viscous incompressible fluid in a generator of rectangular section having finite electrodes and the rest of its walls being insulating. It is assumed that in the electrodes region a homogeneous magnetic field is applied, whose orientation is normal to the plane of the motion. If the induced magnetic field is neglected, the current function ψ(x, y) and the electrical potential ϕ(x, y) satisfy a system of equations with partial derivatives of the second order, with distributions. Since the system depends upon the parameter λ = RM RH a method of successive approximations is developed, which permits one to obtain the exact solution of the problem. In the last paragraph the results are extended to the case of a generator with N pairs of symmetrical electrodes.
Invariance relations in thermoelasticity with generalized variables
Authors: Hill R. 
Published: November 2008

AbstractIn the spirit of generalized coordinates in Lagrangian mechanics, the finite deformation of a material element is considered to be specified by arbitrary geometric variables, and the associated generalized stresses are generated by work conjugacy. The comparative quantitative influences of such coordinate choices are investigated for the main state variables in anisotropic thermoelasticity, namely the moduli, compliances, thermal coefficients of expansion, pressure coefficients, and specific heats. Transformation formulae are obtained to connect the respective values of the state variables for different choices. Special attention is given to the identification of coordinate-invariant magnitudes and relationships. The entire analysis is carried farther for coordinates in a class of tensor measures of finite strain; such measures are used widely in current theories of the mechanical response of solid materials, but apparently not yet in regard to thermal phenomena.
Poincaré and Friedrichs inequalities in abstract Sobolev spaces II
Authors: Edmunds D. E. , Opic B. , Rákosník J. 
Published: November 2008

This paper is a continuation of [4]; its aim is to extend the results of that paper to include abstract Sobolev spaces of higher order and even anisotropic spaces. Let Ω be a domain in ℝN, let X = X(Ω) and Y = Y(Ω) be Banach function spaces in the sense of Luxemburg (see [4] for details), and let W(X, Y) be the abstract Sobolev space consisting of all f ∈ X such that for each i ∈ {l, …, N} the distributional derivative belongs to Y; equipped with the normW(X, Y) is a Banach space. Given any weight function w on Ω, the triple [w, X, Y] is said to support the Poincaré inequality on Ω. if there is a positive constant K such that for all u ∈ W(X, Y)the pair [X, Y] is said to support the Friedrichs inequality if there is a positive constant K such that for all u ∈ W0(X, Y) (the closure of in W(X, Y))
Effect of Vowel Identity and Onset Asynchrony on Concurrent Vowel Identification
Authors: Hedrick Mark S. , Madix Steven G. 
Published: October 2008

Purpose
The purpose of the current study was to determine the effects of vowel identity and temporal onset asynchrony on identification of vowels overlapped in time.

Method

Fourteen listeners with normal hearing, with a mean age of 24 years, participated. The listeners were asked to identify both of a pair of 200-ms vowels (referred to as
double vowels
) presented either simultaneously or with a temporal asynchrony ranging from 25 ms to 150 ms in 25-ms steps. The stimuli were synthetic steady-state vowels /i æ ɑ u ɝ/ arranged in seven combinations: /u i/, /æ ɑ/, /ɝ ɑ/, /ɝ æ/, /æ i/, /ɝ i/, and /ɝ u/.

Results

Listeners' responses revealed that one vowel of a pair was identified correctly more often than the other vowel (known as
vowel dominance
). Vowel dominance effects were seen for 6 of the 7 vowel pairs, and there was improvement of vowel identification with increasing temporal separation between vowels for 5 of the 7 pairs. Vowel pairs with the vowel /ɝ/ consistently yielded improved identification with increases in temporal asynchrony.

Discussion
Peripheral masking cannot explain the patterns of results of this study. A more parsimonious explanation may be perceptual anchoring.
Phonological Constraints on Children’s Production of English Third Person Singular –
s
Authors: Yung Song Jae , Sundara Megha , Demuth Katherine 
Published: October 2008

Purpose

Children variably produce grammatical morphemes at early stages of development, often omitting inflectional morphemes in obligatory contexts. This has typically been attributed to immature syntactic or semantic representations. In this study, the authors investigated the hypothesis that children’s variable production of the 3rd person singular morpheme –
s
interacts with the phonological complexity of the verb stem to which it is attached.

Method
To explore this possibility, the authors examined longitudinal data from the spontaneous speech of 6 English-speaking children between ages 1;3 and 3;6 (years;months) and elicited imitations from a cross-sectional study of 23 two-year-olds (mean age of 2;2).

Results

The results showed that children produced third person singular morphemes more accurately in phonologically simple coda contexts (e.g.,

see
s

) as compared with complex coda contexts (e.g.,

nee
ds

). In addition, children produced
–s
more accurately in utterance-final position as compared with utterance-medial position.

Conclusions

The results provide strong support for the role of phonological complexity in explaining some of the variability in children’s production of third person singular –
s
. This finding suggests that future research will need to consider multiple factors, including phonological and positional effects, in constructing a comprehensive developmental theory of both grammatical competence and processes of speech planning and production.
Discrimination of Speech Sounds Based Upon Temporal Envelope Versus Fine Structure Cues in 5- to 7-Year-Old Children
Authors: Bertoncini Josiane , Serniclaes Willy , Lorenzi Christian 
Published: October 2008

PurposeTo investigate the capacity of young children and adults with normal hearing to discriminate speech on the basis of either relatively slow (temporal envelope, E) or fast (temporal fine structure, TFS) auditory cues.MethodVowel-consonant-vowel nonsense disyllables were processed to preserve either the E or the TFS information in 16 adjacent frequency bands. The band signals were then recombined and resulting stimuli were presented for discrimination to adults or 5-, 6-, and 7-year-old children using an odd-ball paradigm. Discrimination scores (d′) and response latencies were measured in each listener. No training was given to listeners.ResultsOverall, discrimination scores were high (d′≥1) in all speech-processing conditions, and did not differ across age groups. Overall, and irrespective of age, greater discrimination scores and shorter response latencies were observed for E speech than for TFS speech.ConclusionsThese results suggest that normal-hearing children are able to encode and use E and TFS speech cues at adult levels by the age of 5 years. TFS- and E-coded speech stimuli might therefore prove to be a useful tool for the investigation of the developmental time course of speech perception, and for the early diagnosis of peripheral and central auditory processing disorders.
Factor Structure and Reliability of the Dutch Version of Seven Scales of the Communication Profile for the Hearing Impaired (CPHI)
Authors: Mokkink Lidwine B. , Knol Dirk L. , Zekveld Adriana A. , Goverts S. Theo , Kramer Sophia E. 
Published: October 2008

PurposeSeven scales of the Communication Profile for the Hearing Impaired (CPHI; M. E. Demorest & S. A. Erdman, 1987) were translated into Dutch: Maladaptive Behavior, Verbal Strategies, and Nonverbal Strategies (within the area of Communication Strategies) and Self-Acceptance, Acceptance of Loss, Stress, and Withdrawal (within the area of Personal Adjustment).MethodThis cross-sectional study evaluated the factor structure, internal consistency, test–retest reliability, and measurement error of the Dutch CPHI scales. In all, 399 adults with impaired hearing participated, and data on a subgroup of 40 patients were included in the test–retest analyses. The participants completed the questionnaire before routine clinical care or at home. Demographic data and data on pure-tone hearing thresholds were also collected.ResultsBased on item factor analyses, we omitted 5 items, moved 3 items to different scales, and combined the Stress and Withdrawal scales. The resulting 6 scales, containing 52 items, showed good internal consistency (alphas between 0.81 and 0.94), good test–retest reliability (intraclass correlation coefficients between 0.78 and 0.86), and small standard error of measurement (between 0.28 and 0.46).ConclusionsThe suggested revisions of the Dutch CPHI scales will increase their interpretability. Further research is needed to evaluate their usefulness for monitoring patients and in longitudinal studies by determining their responsiveness and minimal important change values.
Spectral Tilt Change in Stop Consonant Perception by Listeners With Hearing Impairment
Authors: Alexander Joshua M. , Kluender Keith R. 
Published: October 2008

Purpose
To evaluate how perceptual importance of spectral tilt is altered when formant information is degraded by sensorineural hearing loss.

Method

Eighteen listeners with mild to moderate hearing impairment (HI listeners) and 20–23 listeners with normal hearing (NH listeners) identified synthesized stimuli that varied in second formant (F
2
) frequency and spectral tilt. Experiments 1 and 2 examined utterance-initial stops (/ba/ and /da/), and Experiments 3 and 4 examined medial stops (/aba/ and /ada/). Spectral tilt was manipulated at either consonant onset (Experiments 1 and 3), vowels (Experiments 2 and 4), or both (Experiment 5).

Results

Regression analyses revealed that HI listeners weighted F
2
substantially less than NH listeners. There was no difference in absolute tilt weights between groups. However, HI listeners emphasized tilt as much as F
2
for medial stops. NH listeners weighted tilt primarily when F
2
was ambiguous, whereas HI listeners weighted tilt significantly more than NH listeners on unambiguous F
2
endpoints.

Conclusions

Attenuating changes in spectral tilt can be as deleterious as taking away F
2
information for HI listeners. Recordings through a wide dynamic range compression hearing aid show compromised changes in spectral tilt, compressed in range by up to 50%.
Test–Retest Reliability of Low-Level Evoked Distortion Product Otoacoustic Emissions
Authors: Stuart Andrew , Passmore Amy L. , Culbertson Deborah S. , Jones Sherri M. 
Published: October 2008

Purpose

The purpose of this study was to examine test–retest reliability of low-level evoked distortion product otoacoustic emissions (DPOAEs) as a function of L
1
, L
2
level; f
2
frequency; and test condition. A predictive relationship between these variables and the presence/absence of DPOAE responses was also examined.

Method

Sixteen normal-hearing young adults participated. DPOAEs were evoked to 12 tones with f
2
frequencies ranging from 1500 Hz to 7546 Hz at 4 L
2
levels between 45 dB SPL and 30 dB SPL. Four test conditions were employed: (a) initial test, (b) retest without probe removal, (c) retest with probe reinsertion, and (d) retest with probe reinsertion by a second tester.

Results

L
1
, L
2
level and f
2
frequency were statistically significant (
p
< .0001) predictors of a DPOAE response (i.e., the presence of a DPOAE response was more likely to be observed at higher L
1
, L
2
levels and lower f
2
frequencies regardless of test condition). DPOAE levels were significantly affected by L
1
, L
2
level and f
2
frequency (
p
< .0001) but not by test condition. Intra- and intertester test–retest differences were not significantly different.

Conclusions
The prevalence of missing responses coupled with large intersubject variability and intrasubject test–retest variability are a detriment to the clinical utility of DPOAEs evoked with low-level stimuli.