bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wall coating for capillary electrophoresis on microchips
Authors: Dolník Vladislav 
Published: November 2004

AbstractThis review article with 116 references describes recent developments in the preparation of wall coatings for capillary electrophoresis (CE) on a microchip. It deals with both dynamic and permanent coatings and concentrates on the most frequently used microchip materials including glass, poly(methyl methacrylate), poly(dimethyl siloxane), polycarbonate, and poly(ethylene terephthalate glycol). Characterization of the channel surface by measuring electroosmotic mobility and water contact angle of the surface is included as well. The utility of the microchips with coated channels is demonstrated by examples of CE separations on these chips.
Understanding the Fisher equation
Authors: Sun Yixiao , Phillips Peter C. B. 
Published: November 2004

AbstractIt is argued that univariate long memory estimates based on ex post data tend to underestimate the persistence of ex ante variables (and, hence, that of the ex post variables themselves) because of the presence of unanticipated shocks whose short‐run volatility masks the degree of long‐range dependence in the data. Empirical estimates of long‐range dependence in the Fisher equation are shown to manifest this problem and lead to an apparent imbalance in the memory characteristics of the variables in the Fisher equation. Evidence in support of this typical underestimation is provided by results obtained with inflation forecast survey data and by direct calculation of the finite sample biases.To address the problem of bias, the paper introduces a bivariate exact Whittle (BEW) estimator that explicitly allows for the presence of short memory noise in the data. The new procedure enhances the empirical capacity to separate low‐frequency behaviour from high‐frequency fluctuations, and it produces estimates of long‐range dependence that are much less biased when there is noise contaminated data. Empirical estimates from the BEW method suggest that the three Fisher variables are integrated of the same order, with memory parameter in the range (0.75, 1). Since the integration orders are balanced, the ex ante real rate has the same degree of persistence as expected inflation, thereby furnishing evidence against the existence of a (fractional) cointegrating relation among the Fisher variables and, correspondingly, showing little support for a long‐run form of Fisher hypothesis. Copyright © 2004 John Wiley & Sons, Ltd.
The substrate specificity and susceptibility to wheat inhibitor proteins of Penicillium funiculosum xylanases from a commercial enzyme preparation
Authors: Furniss Caroline SM , Williamson Gary , Kroon Paul A 
Published: November 2004

AbstractFilamentous fungi produce a range of carbohydrate‐degrading enzymes, in particular hemicellulases, that are often exploited by the baking, brewing and feed industries. Controlled xylan degradation is a key component in several industrial processes, in which the efficiency of xylanases (endo‐1,4‐β‐D‐xylan hydrolases) depends on both their substrate specificity and their susceptibility to inhibitors present in the plant material. The three major xylanases present in a commercial hemicellulase product derived from a Penicillium funiculosum fermentation broth were characterized with respect to their substrate specificity and interaction with three known xylanase inhibitor proteins (XIP‐I, TAXI I and TAXI II) present in wheat flour. XYNA (48 kDa) and XYNB (22 kDa) have significant sequence similarity with family 7 cellobiohydrolases and family 11 xylanases respectively (previous studies), while XYND (36 kDa) has similarity with family 10 xylanases (this paper). All three enzymes hydrolysed various heteroxylan substrates, including birchwood xylan and soluble wheat arabinoxylan, at 30 °C and pH 5.5. XYNA was strongly inhibited by XIP‐I, TAXI I and TAXI II (Ki = 106, 46 and 46 nM respectively); XYNB was only significantly inhibited by TAXI I (Ki = 165 nM). In each case the inhibition of XYNA and XYNB was competitive. XYND was only inhibited by XIP‐I but, in contrast to XYNA and XYNB, the apparent inhibition was dependent on the order that xylanase, inhibitor and substrate were added to the incubation mixture; the inhibition was weak when incubations were initiated by addition of xylanase (to a mixture of substrate and XIP‐I), but was very strong when enzyme and XIP‐I were pre‐incubated before addition of substrate. These findings demonstrate that the susceptibility of individual xylanases to inhibitor proteins present in cereals is likely to be a critical factor in determining their efficiency in various commercial applications. Copyright © 2004 Society of Chemical Industry
Free amino acids and volatile compounds in vinegars obtained from different types of substrate
Authors: Valero Eva , Berlanga Teresa M , Roldán Pedro M , Jiménez Carlos , García Isidoro , Mauricio Juan C 
Published: November 2004

AbstractThe present work reports on the free amino acids and volatile compounds in vinegars obtained from different types of raw materials (cider, white wine and red wine). Based on the amino acid contents of three types of vinegar and of the substrates from which they were obtained, the profile of the nitrogen‐supplying compounds and their uptake for the acetic acid bacteria were very similar. The most important amino acid in terms of supply and uptake was found to be L‐leucine. L‐Proline proved also important in the wine vinegars, however it was not depleted as L‐leucine. The different acetification reactions involved were found to yield acetoin, and plus 1,1‐diethoxyethane in the wine vinegars. Copyright © 2004 Society of Chemical Industry
Effects of inoculation of high dry matter alfalfa silage on ensiling characteristics, ruminal nutrient degradability and dairy cow performance
Authors: Rizk Charbel , Mustafa Arif F , Phillip Leroy E 
Published: November 2004

AbstractThe objective of this study was to determine the effects of a homolactic acid inoculant on ensiling characteristics and nutritive value of high dry matter (DM) alfalfa. The ensiling characteristics were determined by ensiling inoculated and untreated alfalfa haylage in mini‐silos for 0, 2, 4, 8, 16 and 45 days. Two lactating cows fitted with ruminal fistulas were used to determine ruminal degradabilities of nutrient in inoculated and untreated alfalfa silage (45‐day silage). Effects of feeding inoculated and untreated alfalfa silage on animal performance were determined using 28 lactating dairy cows fed total mixed diets (40% forage and 60% concentrate) with the forage portion consisting of inoculated or untreated alfalfa silage. The pH of the inoculated silage declined from 5.9 to 4.5 within 2 days of ensiling while the pH of the untreated silage did not drop below 5 until day 16 post‐ensiling. At all ensiling times, inoculated alfalfa silage had lower pH than untreated alfalfa silage. The concentration of lactic acid was higher while that of water‐soluble carbohydrates was lower for inoculated than untreated alfalfa silage at all ensiling times. Inoculation increased proteolysis as indicated by a reduction in true protein and neutral detergent insoluble protein and an increase in non‐protein nitrogen. Ruminal degradability of DM, crude protein and neutral detergent fiber of alfalfa silage were not affected by inoculation. The average effective degradability of dry matter, crude protein and neutral detergent fiber was 66, 65 and 62%, respectively. Dairy cows fed inoculated alfalfa silage had DM intake (average 22 kg day−1) and milk yield (average 42 kg day−1) similar to cows fed untreated alfalfa silage. It was concluded that the inoculant used in this study improved the ensiling characteristics of alfalfa silage with no significant effects on dairy cow performance. Copyright © 2004 Society of Chemical Industry
In vitro availability of starch in heat‐treated potatoes as related to genotype, weight and storage time
Authors: Leeman A Margareta , Bårström L Mattias , Björck Inger ME 
Published: November 2004

AbstractThe objective of the study was to determine the influence of potato variety, weight and storage time after lifting on the glycaemic index (GI) and resistant starch (RS) content predicted from measurement of the rate and extent of in vitro starch hydrolysis, respectively. The potatoes were either boiled, or boiled and subjected to different heat‐cycling conditions selected to promote retrogradation of amylose or amylopectin, respectively. The hydrolysis indices (HI) and predicted GIs of all 19 potato products were high and fell within narrow ranges of 122–144 and 118–138, respectively. No correlation between average weight of the potato tuber and HI was found. Furthermore, there was no difference in HI between potatoes stored for 1–3 or 8–10 months, nor between varieties of new potato and winter potato. However, the HI was significantly lowered by temperature cycling at conditions known to promote retrogradation of amylopectin (6 °C, 48 h) compared with 6 °C for 24 h followed by 70 °C for 24 h. RS content was already substantial in boiled potatoes, 4.5 g 100 g−1 (starch basis), and could be increased further by temperature cycling, the highest yield obtained, 9.8 g 100 g−1 (starch basis), following heat treatment at 6 °C for 24 h followed by 70 °C for 24 h; that is at conditions known to favour amylose retrogradation. Copyright © 2004 Society of Chemical Industry
Content of low molecular weight carbohydrates in vining peas (Pisum sativum) after blanching and freezing: effect of cultivar and cultivation conditions
Authors: Ekvall J , Stegmark R , Nyman M 
Published: November 2004

AbstractThe content of low molecular weight carbohydrates (LMWC, glucose, fructose, sucrose, raffinose, stachyose and verbascose) was investigated in 29 cultivars of vining peas after blanching and freezing. The peas were harvested at about the same degree of ripeness. There was a positive correlation between the amount of raffinose, stachyose and sorbitol, while a high content of verbascose only could be seen when there was a low content of these sugars. High concentrations of sucrose were generally associated with high concentrations of glucose and fructose. Samples from 1999 had a significantly (p < 0.001) higher content of raffinose, stachyose and sorbitol and lower of verbascose, probably because of the drier and warmer summer that year compared with 1998. Furthermore, medium and late maturing cultivars contained larger amounts of raffinose, stachyose and sorbitol than early cultivars, possibly due to the fact that these cultivars, to a greater extent, were exposed to a higher temperature and more intense sunlight for a longer time. Considerable differences in the content of LMWC could be seen both between the different cultivars and the various trials. Glucose and sucrose were generally similarly affected by cultivar and cultivation conditions, while cultivation conditions had a greater influence on the content of sorbitol and the raffinose family oligosaccharides (RFO; raffinose, stachyose, verbascose) in late‐maturing groups. It is concluded that many factors affect the content of LMWC in peas. However, as the content of RFO is comparatively small in vining peas, any nutritional significance of these sugars in the human colon is probably rather small. Copyright © 2004 Society of Chemical Industry
Effect of electronegativity on transport properties of (La0.83M0.17)0.67Ca0.33MnO3 (M = Y, Bi)
Authors: Xia Z. C. , Dong B. , Liu G. , Liu D. W. , Chen L. , Fang C. H. , Liu L. , Liu S. , Tang C. Q. , Yuan S. L. 
Published: November 2004

AbstractElectrical transport and magnetic properties of (La0.83M0.17)0.67Ca0.33MnO3 (M = Y and Bi) have been investigated. Experimental results show that the doped samples have obviously different electrical transport and magnetic properties; the difference cannot be interpreted only on the basis of the effect of the ionic radius 〈rA〉, where 〈rA〉 is the average ionic radii of A‐site cations. Together with the ionic radius and the electronegativity of the doping ion, the differences of electrical transport and magnetic properties between the Bi3+‐ and Y3+‐doped (La0.83M0.17)0.67Ca0.33MnO3 are discussed, in which the electronegativity has an important effect on the electrical transport and magnetic properties. Especially, the Bi‐doped sample shows an enhanced magnetoresistance with a widened temperature window, which is encouraging concerning the potential application of magnetoresistive materials. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Orientation dependence properties of modified tetragonal 0.88Pb(Zn1/3Nb2/3)O3–0.12PbTiO3 single crystals
Authors: Zhang Shujun , Lebrun Laurent , Randall Clive A. , Shrout Thomas R. 
Published: November 2004

AbstractTetragonal 0.88Pb(Zn1/3Nb2/3)O3–0.12PbTiO3 (PZNT12) single crystals were found to possess high electromechanical coupling k33 ∼ 86–88% and large coercive field ∼8 kV/cm, while exhibiting good temperature stability till its Curie temperature (TC) ∼190 °C. The role of dopants on the dielectric and piezoelectric properties of PZNT12 crystals modified with the Fe, Co, Ce and Mn, all resulted in a downward shift of TC, effectively increasing the dielectric permittivity, while the mechanical quality factor Q was found to be greatly improved. The detailed characterization of doped Mn‐PZNT12 crystals was performed along different crystallographic orientations, in which the figure of merit d · Q was found to be the highest when the sample was poled along the [110] direction, along with a very low strain‐electric field hysteresis, making the manganese modified PZNT12 crystals promising candidates for high power resonance transducers. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bayesian non‐response models for categorical data from small areas: an application to BMD and age
Authors: Nandram Balgobin , Liu Ning , Choi Jai Won , Cox Lawrence 
Published: November 2004

AbstractWe provide a Bayesian analysis of data categorized into two levels of age (younger than 50 years, at least 50 years) and three levels of bone mineral density (normal, osteopenia, osteoporosis) for white females at least 20 years old in the third National Health and Nutrition Examination Survey. For the sample, the age of each individual is known, but some individuals did not have their BMD measured. We use two types of models: In the ignorable non‐response models the propensity to respond does not depend on BMD and age of an individual, while in the non‐ignorable non‐response models it does. These are the baseline models which are used to derive all models for testing. Our non‐ignorable non‐response models are ‘close’ to the ignorable non‐response models, thereby reducing the effects of the assumptions about non‐respondents that cannot be tested in non‐response models. We have data from 35 counties, small areas, and therefore our models are hierarchical, a feature that allows a ‘borrowing of strength’ across the counties, and they provide a substantial reduction in variation. The non‐ignorable non‐response models are generalizations of the ignorable non‐response models, and therefore, the non‐ignorable non‐response models allow broader inference. The joint posterior density of the parameters for each model is complex, and therefore, we fit each model using Markov chain Monte Carlo methods to obtain samples which are used to make inference about BMD and age. For each county we can estimate the proportion of individuals in each BMD and age cell of the categorical table, and we can assess the relation between BMD and age using the Bayes factor. A sensitivity analysis shows that there are differences (typically small) in inference that permits different levels of association between BMD and age. A simulation study shows that there is not much difference between the baseline ignorable and non‐ignorable non‐response models. Copyright © 2004 John Wiley & Sons, Ltd.
Simple fitting of subject‐specific curves for longitudinal data
Authors: Durbán M. , Harezlak J. , Wand M. P. , Carroll R. J. 
Published: November 2004

AbstractWe present a simple semiparametric model for fitting subject‐specific curves for longitudinal data. Individual curves are modelled as penalized splines with random coefficients. This model has a mixed model representation, and it is easily implemented in standard statistical software. We conduct an analysis of the long‐term effect of radiation therapy on the height of children suffering from acute lymphoblastic leukaemia using penalized splines in the framework of semiparametric mixed effects models. The analysis revealed significant differences between therapies and showed that the growth rate of girls in the study cannot be fully explained by the group‐average curve and that individual curves are necessary to reflect the individual response to treatment. We also show how to implement these models in S‐PLUS and R in the appendix. Copyright © 2004 John Wiley & Sons, Ltd.
Semi‐parametric modelling for costs of health care technologies
Authors: Conigliani C. , Tancredi A. 
Published: November 2004

AbstractCost data that arise in the evaluation of health care technologies usually exhibit highly skew, heavy‐tailed and, possibly, multi‐modal distributions. Distribution‐free methods for analysing these data, such as the bootstrap, or those based on the asymptotic normality of sample means, may often lead to inefficient or misleading inferences. On the other hand, parametric models that fit the data (or a transformation of the data) equally well can produce very different answers. We consider a Bayesian approach, and model cost data with a distribution composed of a piecewise constant density up to an unknown endpoint, and a generalized Pareto distribution for the remaining tail. Copyright © 2004 John Wiley & Sons, Ltd.
Statistical consideration of the strategy for demonstrating clinical evidence of effectiveness—one larger vs two smaller pivotal studies
Authors: Shun Zhenming , Chi Eric , Durrleman Sylvain , Fisher Lloyd 
Published: November 2004

AbstractAs a regulatory strategy, it is nowadays not uncommon to conduct one confirmatory pivotal clinical trial, instead of two, to demonstrate efficacy and safety in drug development. This paper is intended to investigate the statistical foundation of such an approach. The one‐study approach is compared with the conventional two‐study approach in terms of power, type‐I error, and fundamental statistical assumptions. Necessary requirements for a single‐study model is provided in order to maintain equivalent evidence as that from a two‐study model. In general, one‐study model is valid only under a ‘one population’ assumption. In addition, higher data quality and more convincing and robust results need to be demonstrated in such cases. However, when ‘one‐population’ assumption is valid and appropriate methods are selected, a one‐study model can have a better power using the same sample size. The paper also investigates statistical assumptions and methods for making an overall inference when a two‐study model has been used. The methods for integrated analysis are evaluated. It is important for statisticians to select correct pooling strategy based on the project objective and statistical hypothesis. Copyright © 2004 John Wiley & Sons, Ltd.
Excess of nutrients results in plant stress and decreased grass miner performance
Authors: Scheirs Jan , De Bruyn Luc 
Published: November 2004

AbstractWe studied the relationship between plant stress intensity and herbivore response in the grass miner Chromatomyia milii (Kaltenbach) (Diptera: Agromyzidae) on nutrient stressed plants. We subjected the host grass Holcus lanatus (Poaceae) to a range of nutrient treatments (0%, 25%, 50%, 100%, and 200% Hoagland nutrient solution) and recorded plant stress intensity (plant growth and foliar chlorophyll a and b levels) and offspring performance of C. milii. Plant growth and foliar chlorophyll a and b levels decreased from the 25% treatment to the 200% treatment. The plant stress intensity from the 0% treatment was equal to or only slightly higher than the 25% treatment. Offspring survival of C. milii was lower on the 100% and the 200% treatments than on the other treatments. Offspring development time and pupal mass did not differ between the nutrient treatments. Offspring survival of C. milii showed a monotonic non‐linear increase with decreasing plant stress intensity. These results clearly show that an excess of nutrients may result in plant stress and reduced herbivore performance.
THE POLITICAL ECONOMY OF FOREST POLICY IN MEXICO AND CHILE
Authors: Silva Eduardo 
Published: November 2004

ABSTRACTWidespread agreement exists on the broad outlines of the concept of sustainable development for developing countries. This calls for a development model capable of meeting basic needs without depleting natural resources at a rate that robs future generations of their use. In this regard, citizen participation is also considered key to legitimise such policy choices. However, there is considerable disagreement over the substance and meaning of the major components of the concept and the relationship between them. This paper argues that positions in policy disputes over the sustainable development of the forest cluster in two distinct approaches: market‐friendly initiatives and grassroots development. Since market economies prevail almost everywhere, the question that is posed concerns the conditions under which the grassroots development approach is included as a significant complement to market‐friendly initiatives. This is a political question, requiring an examination of actors, interests and power resources. The paper thus applies a political economy framework to a paired comparison of Mexico, where grassroots development approaches (community forestry) had notable successes, and Chile, where market‐friendly forest policy crowded out alternatives.
SOCIAL AND ENVIRONMENTAL IMPACTS OF WORLD BANK/IMF‐FUNDED ECONOMIC RESTRUCTURING IN BOLIVIA: AN ANALYSIS OF ENRON AND SHELL'S HYDROCARBONS PROJECTS
Authors: Hindery Derrick 
Published: November 2004

ABSTRACTWith the spectacular financial collapse of Enron in 2001, Enron and Shell's Rio San Miguel‐Cuiabá gas pipeline gained international notoriety for degrading the last, most intact dry tropical forest in the world, Bolivia's Chiquitano forest. The paper uses specific case studies, including the case of the Cuiabá pipeline, to examine how economic restructuring sponsored by the World Bank, International Monetary Fund (IMF) and Inter‐American Development Bank (IDB) facilitated the entrance of multinational oil corporations that have caused significant social and environmental impacts in Bolivia. The paper explores the influence of international financial institutions and multinational oil corporations on Bolivian state institutions, particularly their ability to regulate and address impacts caused by developments in the hydrocarbons sector. It concludes that neoliberal policies, which resulted in partial privatisation of the state oil company and in expanded control over natural resources by multinational corporations (MNCs), were detrimental to sensitive ecosystems and indigenous inhabitants.