bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nanochitosan crosslinked with polyacrylamide as the chiral stationary phase for open‐tubular capillary electrochromatography
Authors: Chen Jian‐Lian , Hsieh Kai‐Hsin 
Published: January 2011

AbstractNanoparticles exhibiting favorable surface‐to‐volume ratios create efficient stationary phases for electrochromatography. New nanomaterials derived from chitosan (CS) were immobilized onto modified capillaries for use as the chiral stationary phase (CSP) in open‐tubular electrochromatography. This immobilization was achieved through the copolymerization of glycidyl methacrylate‐modified nano‐CS with methacrylamide (MAA) and bis‐acrylamide crosslinkers (forming the MAA‐CS capillary) rather than the attachment of nano‐CS to the copolymer of glycidyl methacrylate, MAA, and bis‐acrylamide (forming the MAA+CS capillary). The completed MAA‐CS capillary and its precursors were examined by SEM and ATR‐IR measurements. Before separating chiral samples, the MAA‐CS capillary was characterized by electroosmotic flow measurements at varying pH values, concentrations, and volume percentages of organic modifiers in the running buffers. Tryptophan enantiomers were well separated by the MAA‐CS capillary, whereas no enantioselectivity was observed in the MAA+CS capillary. With the addition of 80% MeOH into the phosphate buffer, the chiral separation of (±)‐catechin was accomplished in a normal‐phase mode. However, the new CSP has its limitations, as only two groups of α‐tocopherol stereoisomers were separated.
Metabolomic profiling of human plasma in pancreatic cancer using pressurized capillary electrochromatography
Authors: Zhang Huiping , Wang Yan , Gu Xue , Zhou Junyi , Yan Chao 
Published: January 2011

AbstractThe application of pressurized capillary electrochromatography (pCEC) coupled with ultra violet (UV) detection has been investigated for the production of global metabolite profiles from human plasma, and its capabilities of classifying pancreatic cancer patients. The pCEC separation of plasma samples was performed on a RP column with gradient elution. The applied voltage, detection wavelength and type of acid modifiers on separation of plasma samples were optimized with pooled quality control (QC) sample. The stability and the repeatability of the methodology were also determined by the repeat analysis of QC sample. The effects of different scaling methods on the results of orthogonal partial least‐squares discrimination analysis (OPLS‐DA) based on pCEC‐UV data set were also investigated. The results of the current study clearly showed the different phenotypes of metabolites of pancreatic cancer patients and healthy controls based on pCEC‐UV plasma profiles. OPLS‐DA data are shown to provide a valuable means of convenient classification. This work indicated that pCEC‐UV method can be used as a cost‐effective and information‐rich, while relatively simple and inexpensive approach for plasma profiling on disease metabolomics studies.
Application of the iPLEXTM Gold SNP genotyping method for the analysis of Amerindian ancient DNA samples: Benefits for ancient population studies
Authors: Mendisco Fanny , Keyser Christine , Hollard Clémence , Seldes Veronica , Nielsen Axel E. , Crubézy Eric , Ludes Bertrand 
Published: January 2011

AbstractImportant developments in the matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) technique have generated new perspectives regarding SNP genotyping, which are particularly promising for ancient population‐based studies. The main aim of the present study was to investigate the application of a MALDI‐TOF MS‐based SNP genotyping technique, called iPLEX® Gold, to analyze Amerindian ancient DNA samples. The first objective was to test the sensitivity of the method, which is recommended for DNA quantities between 10 and 5 ng, for ancient biological samples containing DNA molecules that were degraded and present in minute quantities. The second objective was to detail the advantages of this technique for studies on ancient populations. Two multiplexes were designed, allowing the major Amerindian mitochondrial and Y haplogroups to be determined simultaneously. This analysis has never been described before. Results demonstrated the reliability and accuracy of the method; data were obtained for both mitochondrial and nuclear DNA using picogram (pg) quantities of nucleic acid. This technique has the advantages of both MS and minisequencing techniques; thus, it should be included in the protocols for future ancient DNA studies.
Multi‐objective PSO/GA optimization control strategies for energy efficient PMDC motor drives
Authors: Sharaf Adel M. , El‐Gammal Adel A. A. 
Published: January 2011

AbstractThe paper presents the application of genetic algorithm (GA) and particle swarm optimization (PSO) search and optimization techniques for online tuning of error‐driven self‐adjusting multi‐loop dynamic speed regulators for large industrial permanent magnet DC (PMDC) motor drives. Novel three multi‐loop dynamic error regulator include tan‐sigmoid controller, multi‐zone controller, and incremental self‐regulating controllers are developed by First Author and validate by Second Author. The proposed dynamic multi‐loop control strategies are based on time‐discalced and decoupled regulation loops with assigned loop weightings and dynamic loop delays. The three novel dynamic and efficient control schemes utilize speed, current, dynamic momentum excursion error, and limited current ripple errors as the main inputs to vary the firing delay angleαof the six‐pulse controlled Thyristor rectifier. Multi‐objective GA (MOGA) and multi‐objective PSO (MOPSO) are used for selection of the proposed controller's gains to ensure high performance efficient PMDC motor drives and effective robust dynamic tracking of different speed reference trajectories. The optimization process is based on minimizing the system control total error, the steady state error, settling time, rising time, and maximum overshoot. Copyright © 2011 John Wiley & Sons, Ltd.
Fructose, uricase, and the Back‐to‐Africa hypothesis
Authors: Johnson Richard J. , Andrews Peter 
Published: January 2011

AbstractIn the Middle Miocene (approximately 17 to 12 Ma) at least two radiations of fossil apes from East Africa into Eurasia occurred, and, while controversial, some paleoanthropological studies suggest that one of the Eurasian lineages may have returned to Africa to evolve into humans and the African apes. Here, we present a novel argument supporting this hypothesis. Specifically, the global cooling that occurred in the middle Miocene rendered hominoids living in Europe at risk for starvation as seasonal climate change resulted in less availability of fruits during the winter months. During this time, a mutation in uricase occurred in early hominids that resulted in a rise in serum uric acid. Uric acid has been found to potentiate the effect of fructose to increase fat stores, suggesting that the mutation provided a survival advantage. Such a survival advantage would have been less likely to occur in Africa, where the continued presence of tropical rainforests would have been more likely to provide food throughout the year. Furthermore, Miocene apes in Europe were in protected sites where geographic isolation could have allowed the uricase mutation to be rapidly expressed in the entire population. While speculative, we suggest that the uricase mutation supports an extra‐Africa origin of humans.
Why were the first anthropologists creationists?
Authors: Marks Jonathan 
Published: January 2011

AbstractAnthropologists in every generation have been tarred as creationists by radical Darwinians. In only the very first generation of scholarly anthropology, however, does the charge really stick; that is, in the founding tradition of liberal German humanistic anthropology from about 1860–1890. This paper explores the ideas that may have motivated their rejection of evolution.
Phenotypic traits of primate hybrids: Recognizing admixture in the fossil record
Authors: Ackermann Rebecca Rogers 
Published: January 2011

AbstractFor many years, the likelihood that hybridization occurred in human evolution has been debated. Tattersall and Schwartz pointed out one of the core problems with resolving this debate, namely “that nobody has any idea what a Neanderthal/modern human hybrid might look like in theory, and few have dared to suggest in practice that any particular known fossil represents such a hybrid.”1:7117 Moreover, while molecular data is proving increasingly useful for characterising hybrid zones, the utility of the phenotype for this purpose is not clear.2 Here I address these issues, discussing both theoretical and empirically‐derived expectations for what hybrid morphology looks like, with an emphasis on the skeleton of hybrid primates, and consideration of the hominin fossil record.
Characterisation of a landslide fissure pattern by integrating seismic azimuth tomography and geotechnical testing
Authors: Grandjean G. , Bitri A. , Krzeminska D. M. 
Published: January 2011

AbstractIn order to characterise the fissure field provoked by the Super‐Sauze mudslide (South French Alps) in the surface material, we conducted a seismic survey and compared the resultingP‐wave tomogram to surface observations and cone penetrometer tests. The first results show that the distribution of theP‐wave velocities correlates well with the fissure parameters, i.e. density, depth, and thickness, estimated from digital photographs and field observations. In addition, one finds good agreement between theP‐wave velocity distribution and the material resistances interpolated from the penetrometer tests, indicating a probable physical relationship. The results of our study demonstrate that seismic azimuth tomography is efficient for characterising fissure systems with the main advantage of the method lying in the integration capacity of wave propagation compared to local mechanical tests. Provided that the correlation betweenP‐wave velocity and fissure characteristics are confirmed at other sites, this technique could be the basis for future and more systematic studies of high‐hazard zones related to landslides. Copyright © 2011 John Wiley & Sons, Ltd.
Slope‐stability‐constrained design of irrigation canals using particle swarm optimization
Authors: REDDY M. JANGA , ADARSH S. 
Published: January 2011

AbstractThis paper presents a practical methodology for optimal design of open channels considering the slope‐stability aspects and other requirements and propounds the solution of particle swarm optimization (PSO) for solving nonlinear optimization problems. The proposed methodology handles site‐specific conditions such as restrictions on allowable top width and water depths. To ensure the stability of canals under field conditions a slope‐stability constraint is incorporated into the channel design. This constraint is handled through an optimization sub‐routine for computing stability of the canals using PSO. The results of the model show that for all the cases considered in the study the PSO‐based solutions are found to perform well and in some cases better than the traditional solutions. The PSO method provides lot of flexibility in its usage for solving complex channel design problems and it can be used to handle various system requirements in a better way. Copyright © 2011 John Wiley & Sons Ltd.
Exposure of larvae to daily thermocycles affects gonad development, sex ratio, and sexual steroids in Solea senegalensis, kaup
Authors: Blanco‐Vives Borja , Vera Luisa María , Ramos Jesús , Bayarri María José , Mañanós Evaristo , Sánchez‐Vázquez Francisco Javier 
Published: January 2011

AbstractThe effect of water temperature during the development of fish larvae on sex differentiation is well known, but not so well known is the impact of the daily thermocycles. Our aim was to investigate the effect of early exposure of Senegal sole larvae to different temperature cycles on gonad development, sex ratio, and sex steroid (11‐ketotestosterone (11‐KT); estradiol (E2); and testosterone, (T)) content in muscle extracts of juveniles. From 1 to 97 days posthatching (DPH) fish larvae and post‐larvae were subjected to three temperature regimes: Thermophase‐Cryophase (TC), Cryophase‐Thermophase (CT), and constant temperature. In fish exposed to TC, sex determination occurred earlier, because 90% of soles were males/females at 110 DPH, whereas 45% of fish under CT were undifferentiated at that time. Fish under TC showed the highest growth rates, followed by fish under constant temperature and by fish under CT, the differences being statistically significant between the TC and CT groups. Regarding sex ratio, juveniles exposed to TC showed a higher proportion of females than fish under CT or constant temperature. Under TC, fish showed the highest concentration of E2, whereas 11‐KT concentration was highest in fish under CT and constant temperature. Fish under constant temperature and CT showed higher T levels than those under TC. These results provide the first insights into the effect of daily thermocycles on sex differentiation in fish, and underline the key role of natural environmental cycles on the control of sex ratios during larval development, which may be applied to the manipulation of sex ratio in aquaculture. J. Exp. Zool. 315:162–169, 2011. © 2011 Wiley‐Liss, Inc.
Detection of low plasma estradiol concentrations in nesting green turtles (Chelonia mydas) by HPLC/Ms‐Ms
Authors: Mahmoud I.Y. , AlKindi A.Y. , Khan T. , Al‐Bahry S.N. 
Published: January 2011

AbstractIn previous studies on nesting green turtles under natural conditions from different geographical regions, 17‐β‐estradiol (E2) was either undetectable or detected at very low levels. RIA and other related techniques were not sensitive enough to measure low E2 values in the green turtles. In this study, a sensitive method was used in detecting low hormone concentrations: high performance liquid chromatography with tandem quadruple mass spectrometry (HPLC‐MS/MS). Using this technique, estradiol for the first time was detected in nesting green turtles during the peak season (June–October) at Ras Al‐Hadd Reserve, Oman. The E2 values recorded from this study were the highest ever recorded from nesting green turtles in any geographical region, but the levels did not vary significantly throughout different phases of nesting. The presence of E2 during nesting presumably plays a role in the physiology and behavior of this species. Ras Al‐Hadd hosts one of the largest nesting populations of green turtles in the world, and an understanding of their nesting patterns may be of value in conservation and management programs for this endangered species. J. Exp. Zool. 315:170–174, 2011. © 2011 Wiley‐Liss, Inc.
Why ontogenetic homology criteria can be misleading: lessons from digit identity transformations
Authors: Young Rebecca L. , Wagner Günter P. 
Published: January 2011

AbstractAs the basis for comparative biology, correctly assigning character homology is critical. Yet, identifying homologous characters in practice is often challenging. Among the major roadblocks is that the mechanistic bases of character homology remain in question. Thus, investigators must rely on several independent lines of evidence (e.g., character anatomy, phylogenetic distribution, or embryological position); however, these distinct sources of evidence often lead to conflicting diagnoses of character homology. What is more, there is no consensus regarding the relative importance of distinct lines of evidence for determining character homology. Here, we review the difficulties that have hindered the search for the mechanistic bases of character identity, and relate these issues to a recently proposed mechanistic hypothesis of character identity—the Character Identity Network Hypothesis. Next, using two well‐studied cases of homology conflict (i.e., avian and skink digit identity), we assess the utility of different lines of evidence in diagnosing homology. We conclude that, when comparing adult structures, because anatomical characters more closely reflect the actions of the developmental genetic mechanisms of character individuation they are more reliable than embryological homology criteria. J. Exp. Zool. (Mol. Dev. Evol.) 316:165–170, 2011. © 2011 Wiley‐Liss, Inc.
Fire and drought as drivers of early Holocene tree line changes in the Peruvian Andes
Authors: Urrego Dunia H. , Niccum Brittany A. , La Drew Christopher F. , Silman Miles R. , Bush Mark B. 
Published: January 2011

AbstractThree pollen and charcoal records from three lakes lying at 3400 m elevation in southern Peru provided a record of landscape change spanning the last ca.18 000 cal. a BP. The tree line lay close to the site between ca. 16 000 and 12 000 cal. a BP, with Polylepis woodlands growing near the lakes. Progressively drying conditions led to increased fire after 12 000 cal. a BP, coinciding with a decline in Polylepis cover and Andean forest relicts as puna grasslands expanded. A strong decrease in the rate of sediment deposition between ca. 12 000 and ca. 4400 cal. a BP was interpreted to indicate the presence of sedimentary hiatuses. With the return of wet conditions after 4400 cal. a BP, forests did not reassemble around the lakes. Instead, fire‐maintained grasslands dominated the landscape. Humans probably induced the intensified fire activity during the late Holocene and thereby deflected local successions. The modern fragmented landscape, with Polylepsis woodlands existing in fire‐resistant pockets above the general limit of the Andean tree line, resulted from the intensification of human land use practices during the last 4400 cal. a BP. Copyright © 2011 John Wiley & Sons, Ltd.
Cumulative probability functions and their role in evaluating the chronology of geomorphological events during the Holocene
Authors: Chiverrell Richard C. , Thorndycraft Varyl R. , Hoffmann Thomas O. 
Published: January 2011

AbstractCumulative probability functions (CPFs) for large numbers of radiocarbon age determinations are increasingly being used by scientists as a methodology to discern environmental histories. While the recent compilation of regional databases of the radiocarbon dating control for fluvial sediment sequences has been beneficial for identifying gaps in knowledge and stimulating new research, there are a number of problems that critically undermine the use of these CPFs as sensitive hydroclimatic proxies. (i) The CPF method is underpinned by the assumption that each radiocarbon measurement is a true age estimate for a point in time, whereas each measured age in fact forms a scatter around the true age of the sample; (ii) calibration of radiocarbon ages is responsible for much of the structure in CPFs and compounds the problem of scatter and smears the chronological control; (iii) the databases incorporate multiple types of environmental changes differing chronological relationships between the 14C measurements and the dated events, with pre‐dating, dating or post‐dating chronological control each displaying variable length temporal lags all mixed together in the same analysis; and (iv) the radiocarbon ages from individual case studies need to be more robustly tested before being incorporated into regional databases. All these factors negate the value of CPFs as sensitive proxies of environmental change, because peaks in probability for individual radiocarbon measurements are likely to be an incorrect estimate for the age of a geomorphological event and this problem is compounded by combining probabilities for multiple unrelated events. In this paper we present a critical analysis of CPFs and their interpretation before suggesting alternative approaches to analysing radiocarbon geochronologies of geomorphic events, which include: (i) Bayesian age modelling of river terrace development; (ii) developing regional databases that test specific geomorphic hypotheses; (iii) Bayesian age modelling of palaeoflood records; and (iv) analysis of sedimentation rates. Copyright © 2011 John Wiley & Sons, Ltd.
Wet aggregate stability as affected by excess carbonate and other soil properties
Authors: Dimoyiannis D. 
Published: January 2011

ABSTRACTAggregate stability is a fundamental property influencing soil erodibility and hydraulic characteristics. Knowledge of soil components controlling aggregate stability is very important to soil structure conservation. The objective of this study, which was carried out in surface soils from central Greece, was to relate wet aggregate stability to selected soil properties, with emphasis on excessive free carbonate content. The wet‐sieving technique of air‐dried aggregates was used for structural stability evaluation, according to a test that calculates an instability index. The soils studied were developed on Tertiary marly parent material and ranged in calcium carbonate content from 5 to 641 g kg−1. From the texture analysis before and after removal of carbonates, it was concluded that carbonates mainly contributed to total silt and sand fractions, that is to the mechanical fractions which, as a rule, negatively affect aggregate stability. The results of the correlation analysis showed that aggregate stability was positively affected by aluminosilicate clay content, cation exchange capacity (CEC) and Al‐containing sesquioxides. Clay fraction from carbonates and total sand and silt negatively affected aggregate stability. CEC has been proved a very significant determinant of aggregate stability, which in a hyperbolic form relationship with instability index explained 78·9 per cent of aggregate stability variation. Copyright © 2011 John Wiley & Sons, Ltd.
IMPACT OF DECENTRALIZATION REFORMS IN PAKISTAN ON SERVICE DELIVERY—AN EMPIRICAL STUDY
Authors: Aslam Ghazia , Yilmaz Serdar 
Published: January 2011

AbstractBy bringing decision making closer to people, decentralization is expected to improve governance and service delivery outcomes. Yet, the empirical evidence on the impact of decentralization on macroeconomic performance and public sector size presents a mixed picture. However, the findings of cross‐country studies in the literature are sensitive to the way decentralization is defined, and how its extent and impact are measured. This article avoids the unwanted effects of incomparability and aggregation in cross‐country analysis. We use a unique panel data set from 183 villages in Pakistan to analyze the impact of decentralization reforms implemented in 2001 on the provision of services—street paving, construction of water canals, sanitation sewer lines, and school facilities. Our results show that the magnitude of provision of all services increased significantly following decentralization reforms. We further show that the four services are impacted differently and service delivery improvement is not uniform, but not in ways that conform to the hypotheses of patronage theory. Copyright © 2011 John Wiley & Sons, Ltd.