bluuebunny/crossref_metadata_2025 huggingface dataset:
The utility of automated analysis of inter‐simple sequence repeat (ISSR) loci for resolving relationships in the Canary Island species of Tolpis (Asteraceae)
Authors: Archibald Jenny K. , Crawford Daniel J. , Santos‐Guerra Arnoldo , Mort Mark E.
Published: February 2008

Plants of oceanic islands, often remarkably divergent morphologically from continental relatives, are useful models for studying evolution and speciation because evolution is telescoped in time and space. Prior studies revealed little DNA sequence variation within the clade of ca. 10 Canary Island species of Tolpis, which precluded resolving species relationships. The present study assessed the utility of automated analysis of inter‐simple sequence repeat (ISSR) loci for resolving relationships within the clade using 264 individuals from 36 populations of all recognized species and three undescribed morphological variants. Similarity (Dice coefficient) and Fitch parsimony were used to generate neighbor‐joining (NJ) and strict consensus trees (MP), respectively. All individuals of the morphologically distinct endemic species formed clusters in both trees. There is also support for clusters of two undescribed variants in the NJ tree. Individuals from a morphologically variable complex consisting primarily of two species are not well resolved at population or species levels. The NJ and MP trees are not congruent at deeper levels, including relationships among species. Results are interpreted in terms of the biology of the species, and the utility of automated analysis of ISSR markers for interpreting patterns of evolution of Tolpis in the Canary Islands is discussed.
Patterns of long‐distance dispersal in Tiquilia subg. Tiquilia (Boraginaceae): implications for the origins of amphitropical disjuncts and Galápagos Islands endemics
Authors: Moore Michael J. , Tye Alan , Jansen Robert K.
Published: February 2008

Plant biogeographers have long argued whether plant disjunctions result from vicariance or dispersal. One of the classic patterns of plant disjunction involves New World amphitropical disjuncts, as exemplified by Tiquilia subg. Tiquilia (Boraginaceae). Subgenus Tiquilia forms a heterogeneous group of ~20 species that is amphitropically distributed in the deserts of North and South America, with four taxa endemic to the Galápagos Islands. The current study reconstructs the biogeographic history of subg. Tiquilia in order to explore the origins of New World amphitropical disjunction and of Galápagos endemism. A strongly supported phylogeny of the subgenus is estimated using sequence data from matK, ndhF, rps16, ITS, and waxy. Biogeographic analyses using combined and individual marker data sets reveal a complex history of long‐distance dispersal in subg. Tiquilia. Biogeographic reconstructions imply a North American origin of the subgenus and its three major lineages and require at least four long‐distance dispersal events to explain its current distribution. The South American taxa of subg. Tiquilia result from three independent and nonsimultaneous colonization events, while the monophyly and continental origins of the Galápagos endemics are unresolved. This study contributes to a growing body of evidence that intercontinental dispersal has been more common than previously realized.
Molecular phylogenetics reveals Leontodon (Asteraceae, Lactuceae) to be diphyletic
Authors: Samuel Rosabelle , Gutermann Walter , Stuessy Tod F. , Ruas Claudete F. , Lack Hans‐Walter , Tremetsberger Karin , Talavera Salvador , Hermanowski Barbara , Ehrendorfer Friedrich
Published: February 2008

The plastid matK gene, trnL/F spacer, and nuclear rDNA ITS were sequenced for 36 species of Leontodon and 29 taxa of related genera of tribe Lactuceae. Phylogenetic relationships inferred from the independent and combined data are largely congruent and reveal that Leontodon sensu lato (s.l.) as presently defined is diphyletic: L. subgenus Leontodon forms a clade with Helminthotheca, Picris and Hypochaeris as sister genera, whereas L. subgenus Oporinia appears as a separate clade with strong bootstrap support and is thus better treated as a separate genus. Previous sectional classifications of Leontodon s.l. are considered in the light of DNA and additional morphological and karyological data. Support is presented for a core group of Hypochaeridinae sensu stricto (s.s.) with the two clades of Leontodon s.l., Helminthotheca, Picris, and Hypochaeris, whereas Urospermum, Hyoseris, Aposeris, and Rhagadiolus appear to be positioned more distantly.
Worldwide phylogeny and biogeography of Cardamine flexuosa (Brassicaceae) and its relatives
Authors: Lihová Judita , Marhold Karol , Kudoh Hiroshi , Koch Marcus A.
Published: February 2008

Phylogenetic relationships, biogeography, and taxonomy of a group of taxa putatively related to the tetraploid Cardamine flexuosa were explored using sequences of the internal transcribed spacer region of nrDNA (ITS) and the trnL‐trnF region of cpDNA. Taxon sampling focused on eastern Asia, North America, and Europe, and included 19 taxa represented by 177 and 182 accessions for each data set, respectively. Our analyses provided unequivocal evidence that Asian weedy populations traditionally assigned to C. flexuosa form an independent evolutionary lineage and represent a distinct taxon from European C. flexuosa. The allopolyploid origin of this common weed in paddy fields, its origin, and/or spread associated with the establishment of suitable man‐made habitats are suggested. It is also found as an introduced weed in Australia and North America. Phylogenetic relationships and the associated taxonomic implications are presented and discussed for the group as a whole. Contrasting patterns of genetic variation (particularly in cpDNA) among different species were revealed. While very little haplotype diversity was found in widespread C. hirsuta and C. flexuosa, greater variation, showing phylogeographic structure, was observed in the tetraploid C. scutata within a relatively small area of Japan.
Phylogenetic relationships and generic delimitation in subtribe Arctotidinae (Asteraceae: Arctotideae) inferred by DNA sequence data from ITS and five chloroplast regions
Authors: McKenzie Robert J. , Muller Elizabeth M. , Skinner Amy K. W. , Karis Per Ola , Barker Nigel P.
Published: February 2008

Asteraceae are the largest family in southern Africa. Elucidating its origins and radiation in the region requires well‐supported species‐level phylogenies of the lineages. This paper presents a phylogenetic framework for subtribe Arctotidinae, which have a southern and eastern African–Australian distribution centered in the winter‐rainfall region of South Africa. DNA sequence data from five chloroplast fragments (ndhF,psbA‐trnH,rps16,trnS‐trnfM, andtrnT‐trnF) and the nuclear ITS region were analyzed separately and in combination using parsimony and Bayesian methods. The data sets comprised exemplars from 18 ingroup species, representing the five currently accepted genera, and four outgroup species from Gorteriinae. All analyses indicatedArctotisandHaplocarphaare polyphyletic as presently circumscribed. The Australian‐endemicCymbonotus lawsonianuswas placed within a strongly supported clade also containingA. arctotoidesfrom South Africa andH. schimperifrom eastern Africa. Retention ofDymondiaand resurrection ofLandtiaat generic level are strongly supported. The phylogenetic hypotheses indicate the subtribe might have originated in temperate southern or eastern Africa, or it was ancestrally widespread in southern Africa and has diversified vicariously. The derived placement ofC. lawsonianusindicates long‐distance dispersal from southern Africa to Australia occurred.
Population differentiation for plasticity to light in an annual herb: Adaptation and cost
Authors: Bell Daniela L. , Galloway Laura F.
Published: February 2008

Phenotypic plasticity allows plants to cope with environmental heterogeneity. Environmental variation among populations may select for differentiation in plasticity. To test this idea, we used the annual plant Geranium carolinianum, which inhabits old fields that are densely vegetated and lack canopy cover and wood margins with tree shade but less neighbor shade. Individuals from three populations of each habitat were planted in natural low and high light environments, and morphological traits important for light acquisition were measured. Old‐field plants were more plastic, with greater elongation of petioles and internodes in low light than those from wood margins. This larger shade avoidance response suggests evolution of greater plasticity to neighbor shade than to the tree canopy. Fitness of old‐field plants was high across both light environments, whereas fitness of wood‐margin plants was reduced in low light. Selection favored longer internodes in low than high light. Finally, plasticity for internode length was negatively associated with fitness in high light, suggesting a cost of plasticity for this trait. Together these results indicate that shade‐avoidance plasticity of petiole and internode length is adaptive. However, greater elongation of internode length may be constrained by the cost of plasticity expressed in high light. The evolution of plasticity appears to reflect a balance between its adaptive nature and its cost to fitness.
Protein Tyrosine Phosphatases: New Markers and Targets in Oncology?
Authors: Hardy S. , Tremblay M. L.
Published: February 2008

The discovery nearly 30 years ago that v-src (the form of the Src kinase encoded by Rous sarcoma virus) employs tyrosine kinase activity for transforming cells [...]
Chinese Medicine and Biomodulation in Cancer Patients—Part One
Authors: Sagar S. M. , Wong R. K.
Published: February 2008

Traditional Chinese Medicine (tcm) may be integrated with conventional Western medicine to enhance the care of patients with cancer. Although tcm is normally implemented as a whole system, recent reductionist research suggests mechanisms for the effects of acupuncture, herbs, and nutrition within the scientific model of biomedicine. The health model of Chinese medicine accommodates physical and pharmacologic interventions within the framework of a body–mind network. A Cartesian split does not occur within this model, but to allow for scientific exploration within the restrictions of positivism, reductionism, and controls for confounding factors, the components must necessarily be separated. Still, whole-systems research is important to evaluate effectiveness when applying the full model in clinical practice. Scientific analysis provides a mechanistic understanding of the processes that will improve the design of clinical studies and enhance safety. Enough preliminary evidence is available to encourage quality clinical trials to evaluate the efficacy of integrating tcm into Western cancer care.
Health Management Program: Factors Influencing Completion of Therapy with High-Dose Interferon Alfa-2b for High-Risk Melanoma
Authors: Levesque N. , Mitchinson K. , Lawrie D. , Fedorak L. , MacDonald D. , Normand C. , Pouliot J.F.
Published: February 2008

The goal of the 1-year observational, multicentre, open-label study reported here was to identify factors influencing adherence to high-dose interferon alfa-2b adjuvant therapy in patients at high risk of recurrence following surgical excision of malignant melanoma. The study was carried out in 23 tertiary-care centres across Canada.
Trastuzumab in the Adjuvant Setting: Concurrent or Sequential? It Takes Two to Tango!
Authors: Verma Sunil
Published: February 2008

Two months ago, on routine physical examination by family physician, a 58-year-old woman was diagnosed with a breast lump. [...]
A Thermoresponsive Membrane for Chiral Resolution
Authors: Yang Mei , Chu Liang‐Yin , Wang Hai‐Dong , Xie Rui , Song Hang , Niu Catherine Hui
Published: February 2008

A novel thermoresponsive membrane for chiral resolution with high performance has been developed. The membrane exhibits chiral selectivity based on molecular recognition of beta‐cyclodextrin (β‐CD) and thermosensitivity based on the phase transition of poly(N‐isopropylacrylamide) (PNIPAM). Linear PNIPAM chains were grafted onto porous nylon‐6 membrane substrates by using a plasma‐graft pore‐filling polymerization method; the chains thus acted as microenvironmental adjustors for β‐CD molecules. β‐CD moieties were introduced into the linear PNIPAM chains by a chemical grafting polymerization method and acted as chiral selectors. The phase transition of grafted PNIPAM chains affects the microenvironment of β‐CD molecules and, thus, the association between β‐CD and guest molecules. The chiral selectivity of the prepared thermoresponsive membranes in chiral resolution operated at temperature below the lower critical solution temperature (LCST) of PNIPAM is higher than that of membranes with no thermosensitivity. Furthermore, the decomplexation ratio of enantiomer‐loaded thermoresponsive membranes in decomplexation at temperatures above the LCST is much higher than that of membranes with no thermosensitivity. Thus, by simply changing the operation temperature, high, selective chiral resolution and efficient membrane regeneration are achieved. The proposed membrane provides a new and efficient way to solve the difficult decomplexation problem of chiral solid membranes, which is highly attractive for chiral resolution.
Structure–property relationships of thermoplastic polyurethane elastomers based on polycarbonate diols
Authors: Eceiza A. , Larrañaga M. , de la Caba K. , Kortaberria G. , Marieta C. , Corcuera M. A. , Mondragon I.
Published: February 2008

The phase‐separation behavior and morphology of polycarbonate‐based polyurethanes were investigated as a function of the soft‐segment molecular weight and chemical structure and the 4,4′‐diphenylmethane diisocyanate/1,4‐butanediol based hard‐segment contents. Polarized optical microscopy and atomic force microscopy images showed that the surface morphologies changed as the soft‐segment molecular weight and hard‐segment content varied and also when the sample preparation conditions were modified. An increase in the soft‐ and hard‐segment lengths led to increased phase separation with respect to the lower molecular weight soft segment, and this showed an interlocked and connected morphology of intermixed soft and hard domains. The surface morphology of phase‐separated polyurethanes with hard segments composed of more than four to five 4,4′‐diphenylmethane diisocyanate units contained globular hard‐segment domains formed by spherulites, in which the size and connectivity between the branched lamellae changed with the hard‐segment size. Interlamellar areas related to the soft segment were seen in the spherulites. Variations in the hard‐segment spherulites were observed for polyurethanes based on soft segments of different molecular weights. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
What is user engagement? A conceptual framework for defining user engagement with technology
Authors: O'Brien Heather L. , Toms Elaine G.
Published: February 2008

The purpose of this article is to critically deconstruct the term engagement as it applies to peoples' experiences with technology. Through an extensive, critical multidisciplinary literature review and exploratory study of users of Web searching, online shopping, Webcasting, and gaming applications, we conceptually and operationally defined engagement. Building on past research, we conducted semistructured interviews with the users of four applications to explore their perception of being engaged with the technology. Results indicate that engagement is a process comprised of four distinct stages: point of engagement, period of sustained engagement, disengagement, and reengagement. Furthermore, the process is characterized by attributes of engagement that pertain to the user, the system, and user‐system interaction. We also found evidence of the factors that contribute to nonengagement. Emerging from this research is a definition of engagement—a term not defined consistently in past work—as a quality of user experience characterized by attributes of challenge, positive affect, endurability, aesthetic and sensory appeal, attention, feedback, variety/novelty, interactivity, and perceived user control. This exploratory work provides the foundation for future work to test the conceptual model in various application areas, and to develop methods to measure engaging user experiences.
Application of high‐performance tangential flow filtration (HPTFF) to the purification of a human pharmaceutical antibody fragment expressed in Escherichia coli
Authors: Lebreton Bénédicte , Brown Arick , van Reis Robert
Published: February 2008

High‐performance tangential flow filtration (HPTFF) is shown to successfully enable concentration, purification and formulation in a single unit operation. This is illustrated with feedstreams comprising recombinant proteins expressed in Escherichia coli (E. coli). Using positively charged cellulosic membranes of 100 kDa molecular weight cut‐off and operating under a selected range of buffer pH and ionic strength at a filtrate flux of 100 L m−2 h−1, a 10‐fold removal of E. coli host cell proteins (HCP) was obtained with an overall process yield of 98%. The HPTFF performance was shown to be robust and reproducible. In addition, the novel charged membrane was regenerated and re‐used seven times without loss of selectivity or throughput. When compared with a conventional purification scheme, the proposed process results in the elimination of one chromatographic step, a 12% yield improvement and a significant reduction in purification cost of goods. Biotechnol. Bioeng. 2008;100: 964–974. © 2008 Wiley Periodicals, Inc.
Transseptal puncture for catheter ablation of atrial fibrillation after device closure of patent foramen ovale
Authors: Zaker‐Shahrak Ruzbeh , Jürg Fuhrer  , Meier Bernhard
Published: February 2008

The technique of transseptal puncture for catheter ablation of atrial fibrillation after percutaneous closure of a foramen ovale with the Amplatzer Occluder is demonstrated based on 2 representative cases. © 2008 Wiley‐Liss, Inc.
Catalytic Liquid Phase Oxidation of Toluene to Benzoic Acid
Authors: Gizli A. , Aytimur G. , Alpay E. , Atalay S.
Published: February 2008

The production of benzoic acid from toluene in the liquid phase with pure oxygen was studied. Investigations have been carried out with a view to determining the most suitable reaction conditions with respect to operating variables including oxygen flow rate, reaction temperature, batch time and catalyst loading. In a series of batch experiments carried out at 4 atm, the optimum values of mole ratio of oxygen to toluene, temperature, reaction time, and catalyst loading were found to be 2, 157 °C, 2 h and 0.57 g/L, respectively. In addition, a kinetic study was carried out by taking into consideration the optimum reaction conditions. The model dependent on the formation of benzyl radical was found to be feasible for describing the catalytic oxidation of toluene to benzoic acid in the liquid phase. The activation energy was determined as 40 kJ/mol.
Characterization and Activity of Cu/ZSM5 Catalysts for the Oxidation of Phenol with Hydrogen Peroxide
Authors: Maduna Valkaj K. , Katovic A. , Tomašic V. , Zrncevic S.
Published: February 2008

The heterogeneous catalytic wet peroxide oxidation (CWPO), involving total oxidation of organic compounds to CO2 and H2O is a possible path for the treatment of toxic and bio‐refractory wastewater streams. The aim of this work was to synthesize and characterize three Cu/ZSM5 catalysts prepared by direct hydrothermal synthesis. The mass ratio of the active metal component in the zeolite ranged from 1.62–3.24 wt %. These materials were tested for CWPO of aqueous phenol in a stainless steel Parr reactor, in batch operation under mild conditions (at atmospheric pressure and a temperature of 353 K). The catalyst weight was 0.1 g dm–3 and the initial concentration of phenol and hydrogen peroxide were 0.01 mol dm–3 and 0.1 mol dm–3, respectively. The catalysts were characterized by powder X‐ray diffraction (XRD), scanning electron microscopy (SEM), AAS and ICP‐MS. Their catalytic performance was monitored in terms of phenol and total organic carbon (TOC) conversion, hydrogen peroxide decomposition, by‐product distribution and the degree of copper leached into the aqueous solution. The experimental results indicated that within 180 min, these catalysts facilitated almost complete elimination of phenol and a significant removal of chemical oxygen demand, without significant leaching of Cu ions from the zeolite. The Cu/ZSM5‐DHS3 catalyst with the highest copper loading was proven to be the best candidate. The useful fraction of hydrogen peroxide that contributed to the removal of the organic compounds quantified in terms of selectivity, S, indicated that the CWPO selectivity was always less than 100 %, which meant that there was some self‐degradation of oxidant. It was also shown that oxidation of phenol took place on the catalyst surface via a heterogeneous mechanism, and that the contribution of any homogeneous reaction mechanism was not significant.
Temperature and excitation intensity tuned photoluminescence in Tl4GaIn3S8 layered single crystals
Authors: Goksen K. , Gasanly N. M.
Published: February 2008

Photoluminescence spectra of Tl4GaIn3S8 layered crystals grown by Bridgman method have been studied in the wavelength region of 500–780 nm and in the temperature range of 26–130 K with extrinsic excitation source (λexc = 532 nm), and at T = 26 K with intrinsic excitation source (λexc = 406 nm). Three emission bands A, B and C centered at 514 nm (2.41 eV), 588 nm (2.11 eV) and 686 nm (1.81 eV), respectively, were observed for extrinsic excitation process. Variations in emission spectra have been studied as a function of excitation laser intensity in the 0.9‐183.0 mW cm–2 range for extrinsic excitation at T = 26 and 50 K. Radiative transitions from the donor levels located at 0.03 and 0.01 eV below the bottom of the conduction band to the acceptor levels located at 0.81 and 0.19 eV above the top of the valence band were proposed to be responsible for the observed A‐ and C‐bands. The anomalous temperature dependence of the B‐band peak energy was explained by configurational coordinate model. From X‐ray powder diffraction and energy dispersive spectroscopic analysis, the monoclinic unit cell parameters and compositional parameters of Tl4GaIn3S8 crystals were determined, respectively. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Convenient Synthesis of Cyanine Dyes: Reagents for the Labeling of Biomolecules
Authors: Kvach Maksim V. , Ustinov Alexey V. , Stepanova Irina A. , Malakhov Andrei D. , Skorobogatyi Mikhail V. , Shmanai Vadim V. , Korshun Vladimir A.
Published: February 2008

Four tetramethylindo(di)carbocyanine‐derived carboxylicacids have been prepared using a modified one‐pot procedure for the dye assembly. The acids were converted into oxysuccinimide esters and phosphoramidite reagents. The efficiency of the reagents in the labeling of oligonucleotides and proteins has been demonstrated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Assessing and improving institutional performance
Authors: Henry Thomas C.
Published: February 2008

This chapter describes application of a program review model that guides a college in allocation of resources within an institutionwide management system, thus ensuring the core health of the institution.
Competing in the global higher education marketplace: Outsourcing, twinning, and franchising
Authors: Armstrong Lloyd
Published: February 2008

This chapter discusses some of the drivers, issues, and risks associated with institutional approaches to globalization.
Hematological Oncology: further ahead
Authors: Bertoni Francesco
Published: February 2008

This editorial presents the new editorial structure of Hematological Oncology and summarizes the topics of interest of the journal. Authors are strongly encouraged to submit quality manuscripts regarding all the aspects of haematologic cancers via the Hematological Oncology website at http://mc.manuscriptcentral.com/hon. Copyright © 2008 John Wiley & Sons, Ltd.
Human resources planning on terrorism and crises in the Asia Pacific region: Cross‐national challenge, reconsideration, and proposition from western experiences
Authors: Liou Dian‐Yan , Lin Chin‐Huang
Published: February 2008

Since the 9/11 attacks in the United States (2001) and the two bombing events in Bali (2002, 2005), there has been renewed interest in emergency prevention policies in many organizations around the world. Functional terrorism preparedness requires changes in organizational thinking about external environmental threats. This shift in organizational thinking could be led by human resource departments. In order to achieve this goal, HR departments must redefine their role in terms of crisis management, and then four key planning measures for insuring postemergency operations should be observed. Using system dynamics (SD) methodology, this article examines the causes of states in which organizations operate after terrorist attacks. Based on the qualitative analytic approach of causal loops, this article explores the major challenges for HR development prompted by terrorism. Specifically, we focus on changes both to organizational communication and to workforce planning and succession. These activities are a tremendous challenge immediately following a disaster. A functional HR plan must include elements for proactive alertness, the ability to dispatch inventory, evacuation plans, and record preservation coupled with dissemination to employees and explicit employee training and cross‐cultural management. © 2008 Wiley Periodicals, Inc.
Do race and gender matter in international assignments to/from Asia Pacific? An exploratory study of attitudes among Chinese
Authors: Tung Rosalie L.
Published: February 2008

Based on a survey of EMBA students in China and South Korea, this article examines how two sensitive but potentially salient criteria—race and gender—affect the selection of an executive to head the (a) foreign operations of a U.S. multinational in China and South Korea and (b) newly acquired U.S. operations of a Korean multinational. The results reveal a fairly complex picture of how gender, race, and the interplay of these two factors might affect these decisions. In the Korean sample, competencies mattered more than race and gender in a senior executive appointment to the U.S. operations of Korean multinationals. Also in the Korean sample, race and gender outweighed competencies in assignments to Korea. In the Chinese sample, competencies outweighed race and gender in a senior executive appointment in China. Overall, Koreans had a more positive attitude toward foreign‐born Koreans than the Chinese toward foreign‐born Chinese for senior executive appointments. Implications for international human resource management and diversity management, both theoretical and applied, are discussed. © 2008 Wiley Periodicals, Inc.
Sequential numerical integration in nonlinear state space models for microeconometric panel data
Authors: Heiss Florian
Published: February 2008

This paper discusses the estimation of a class of nonlinear state space models including nonlinear panel data models with autoregressive error components. A health economics example illustrates the usefulness of such models. For the approximation of the likelihood function, nonlinear filtering algorithms developed in the time‐series literature are considered. Because of the relatively simple structure of these models, a straightforward algorithm based on sequential Gaussian quadrature is suggested. It performs very well both in the empirical application and a Monte Carlo study for ordered logit and binary probit models with an AR(1) error component. Copyright © 2008 John Wiley & Sons, Ltd.
Job satisfaction and employee perception of the learning environment in the health care management industry
Authors: Brewer Ernest W. , Lim Doo Hun , Cross Marcia E.
Published: February 2008

This study examines the relationship between job satisfaction and perception of the learning environment of administrative employees and differences in job satisfaction in terms of age, education, ethnicity, gender, location, marital status, position classification, and years of service. A total of 261 administrative employees of a national health care management organization participated in the survey. Major findings of this study revealed significant differences in some subcategories of job satisfaction and perceptions of learning environment in the respondents' ethnicity, age, and office location. Significant relationships were also found between job satisfaction, the perceived learning environment, and facets of the learning environment.
Improved artifact correction for combined electroencephalography/functional MRI by means of synchronization and use of vectorcardiogram recordings
Authors: Mullinger Karen J. , Morgan Paul S. , Bowtell Richard W.
Published: February 2008

Purpose

To demonstrate that two methodological developments (synchronization of the MR scanner and electroencephalography [EEG] clocks and use of the scanner's vectorcardiogram [VCG]) improve the quality of EEG data recorded in combined EEG/functional MRI experiments in vivo.

Materials and Methods

EEG data were recorded using a 32‐channel system, during simultaneous multislice EPI acquisition carried out on a 3 Tesla scanner. Recordings were made on three subjects in the resting state and on five subjects using a block paradigm involving visual stimulation with a 10‐Hz flashing checkerboard.

Results

Gradient artifacts were significantly reduced in the EEG data recorded in vivo when synchronization and a TR equal to a multiple of the EEG clock period were used. This was evident from the greater attenuation of the signal at multiples of the slice acquisition frequency. Pulse artifact correction based on R‐peak markers derived from the VCG was shown to offer a robust alternative to the conventionally used ECG‐based method. Driven EEG responses at frequencies of up to 60 Hz due to the visual stimulus could be more readily detected in data recorded with EEG and MR scanner clock synchronization.

Conclusion

Synchronization of the scanner and EEG clocks, along with VCG‐based R‐peak detection is advantageous in removing gradient and pulse artifacts in combined EEG/fMRI recordings. This approach is shown to allow the robust detection of high frequency driven activity in the EEG data. J. Magn. Reson. Imaging 2008;27:607–616. © 2008 Wiley‐Liss, Inc.
Landform and sediment imprints of fast glacier flow in the southwest Laurentide Ice Sheet
Authors: Evans David J. A. , Clark Chris D. , Rea Brice R.
Published: February 2008

Evidence for former fast glacier flow (ice streaming) in the southwest Laurentide Ice Sheet is identified on the basis of regional glacial geomorphology and sedimentology, highlighting the depositional processes associated with the margin of a terrestrial terminating ice stream. Preliminary mapping from a digital elevation model of Alberta identifies corridors of smoothed topography and corridor‐parallel streamlined landforms (megaflutes to mega‐lineations) that display high levels of spatial coherency. Ridges that lie transverse to the dominant streamlining patterns are interpreted as: (a) series of minor recessional push moraines; (b) thrust block moraines or composite ridges/hill–hole pairs constructed during readvances/surges; and (c) overridden moraines (cupola hills), apparently of thrust origin. Together these landforms demarcate the beds and margins of former fast ice flow trunks or ice streams that terminated as lobate forms. Localised cross‐cutting and/or misalignment of flow sets indicates temporal separation and the overprinting of ice streams/lobes. The fast‐flow tracks are separated by areas of interlobate or inter‐stream terrain in which moraines have been constructed at the margins of neighbouring (competing) ice streams/outlet glaciers; this inter‐stream terrain was covered by more sluggish, non‐streaming ice during full glacial conditions. Thin tills at the centres of the fast‐flow corridors, in many places unconformably overlying stratified sediments, suggest that widespread till deformation may have been subordinate to basal sliding in driving fast ice flow but the general thickening of tills towards the lobate terminal margins of ice streams/outlet glaciers is consistent with subglacial deformation theory. In this area of relatively low relief we speculate that fast glacier flow or streaming was highly dynamic and transitory, sometimes with fast‐flowing trunks topographically fixed in their onset zones and with the terminus migrating laterally. The occurrence of minor push moraines and flutings and associated landforms, because of their similarity to modern active temperate glacial landsystems, are interpreted as indicative of ice lobe marginal oscillations, possibly in response to seasonal climatic forcing, in locations where meltwater was more effectively drained from the glacier bed. Further north, the occurrence of surging glacier landsystems suggests that persistent fast glacier flow gave way to more transitory surging, possibly in response to the decreasing size of ice reservoir areas in dispersal centres and also locally facilitated by ice‐bed decoupling and drawdown initiated by the development of ice‐dammed lakes. Copyright © 2008 John Wiley & Sons, Ltd.
Separation and quantitation of several angiotensin II receptor antagonist drugs in human urine by a SPE–HPLC–DAD method
Authors: Ferreirós Nerea , Iriarte Gorka , Alonso Rosa María , Jiménez Rosa María , Ortíz Eduardo
Published: February 2008

In this work, an SPE–HPLC method coupled to photodiode array detection was validated in human urine matrix, in order to monitor four antihypertensive angiotensin II receptor antagonist drugs in patients under cardiovascular treatment. For that purpose, experimental design was used. Quantitation was accomplished by the internal standard method. The obtained LOQs were 95, 113, 125, and 85 ng/mL for eprosartan, telmisartan, irbesartan, and valsartan, respectively. The intraday and interday precision and accuracy at four concentration levels in the working range (LOQ–15 μg/mL) were always lower than 11% RSD and 8% relative error. The urine samples proved to be stable during 4 h at room temperature, after three thaw‐freeze cycles, and for 2 months at –20°C. No interferences from other endogenous compounds or co‐administered drugs were found. The method has been successfully applied to monitor the renal elimination of eprosartan and valsartan during 24 h.
Instability of hexane–acetonitrile mobile phases used for the chromatographic analysis of triacylglycerides
Authors: Harfmann Robert G. , Julka Samir , Cortes Hernan J.
Published: February 2008

Please note that a wrong DOI has been assigned to this article. The correct DOI of this article is 10.1002/jssc.200700578
Tunable multiwavelength erbium-doped fiber laser with a polarization-maintaining photonic crystal fiber Sagnac loop filter
Authors: Liu Z Y , Liu Y G , Du J B , Kai G Y , Dong X Y
Published: February 2008

We propose and demonstrate a tunable multiwavelength erbium-doped fiber laser based on a polarization-maintaining photonic crystal fiber (PM-PCF) Sagnac loop filter. Stable, room-temperature operation is obtained by employing a nonlinear optical loop mirror. At a central wavelength of 1563.000 nm, we generate 60 wavelengths within 3-dB bandwidth. The measured power fluctuation for each lasing wavelength is less than 0.2 dB in half an hour. Furthermore, by adjusting the polarization controllers in the Sagnac filter, wavelength locations of the laser lines with a fixed channel spacing of ∼ 0.078 nm can be continuously shifted.
Passively mode-locked YVO4/Nd:YVO4 composite crystal laser with a semiconductor saturable absorber as a high reflector
Authors: Zhuo Z , Li T , Wang Y-G
Published: February 2008

A passively mode-locked diode end-pumped YVO4/Nd:YVO4 composite crystal laser with a five-mirror folded cavity was first demonstrated in this paper by using a low temperature semiconductor saturable absorber mirror grown by metal organic chemical vapor deposition. Both the Q-switching and continuous-wave mode locking operation were realized experimentally. A stable averaged output power of 10.15 W with pulse width of about 11.2-ps at a repetition rate of 113 MHz was obtained, and the optical-to-optical efficiency of 43% was achieved.
Risk factors of multiple system atrophy: A case‐control study in French patients
Authors: Vidal Jean‐Sébastien , Vidailhet Marie , Elbaz Alexis , Derkinderen Pascal , Tzourio Christophe , Alpérovitch Annick
Published: February 2008

Multiple system atrophy (MSA) is a rare sporadic progressive neurodegenerative disorder. MSA risk factors are poorly known. The objectives of this case‐control study were to study environmental risk factors associated with MSA. Cases were recruited through five French referral centers. Controls matched for age, gender, and living area were recruited from healthy relatives of inpatients free of any parkinsonian syndrome of the same centers. Subjects were interviewed about exposure to environmental factors (pesticides, solvents, etc.), occupation and food habits, and use of anti‐inflammatory drugs. Odds ratios and 95% confident intervals (OR [95% CI]) were computed using conditional logistic regression. Seventy‐one cases and 71 matched controls were included. Low education level was more frequent in cases than in controls. Controls drank more alcohol than did cases (OR = 0.5 [0.2–1.1]) and the risk of MSA decreased with increasing alcohol consumption (P = 0.04). Controls ate fish and sea food more often and drank more tea than cases. Aspirin intake was more frequent among controls than did cases (OR = 0.5 [0.2–1.0]) and the risk of MSA decreased with the frequency of intake (P = 0.0002). MSA was not associated to exposure to pesticides, solvents, and other toxics neither to occupations, except plant and machine operators and assemblers (OR = 10.0 [2.1–47.5]) where the risk of MSA increased with number of years in this occupation (P = 0.004). This case‐control study provided new findings about risk factors of MSA. On another hand, it did not confirm the previously reported association between MSA and exposure to pesticides. © 2008 Movement Disorder Society
Composite polymer electrolyte membranes comprising triblock copolymer and heteropolyacid for fuel cell applications
Authors: Choi Jin Kyu , Lee Do Kyoung , Kim Yong Woo , Min Byoung Ryul , Kim Jong Hak
Published: February 2008

Hybrid organic/inorganic composite polymer electrolyte membranes consisting of a triblock copolymer (tBC) and varying concentrations of heteropolyacid (HPA) were investigated for application in proton exchange membrane fuel cells (PEMFC). An ABC triblock copolymer, that is, polystyrene‐b‐poly(hydroxyethyl acrylate)‐b‐poly (styrene sulfonic acid), PS‐b‐PHEA‐b‐PSSA, at 28:21:51 wt % was synthesized via atom transfer radical polymerization (ATRP) and solution‐blended with a commercial HPA. Upon the incorporation of HPA into the tBC, the symmetric stretching bands of both the SO group (1187 cm−1) and the OH group (3440 cm−1) shifted to lower wavenumbers (1158 and 3370 cm−1). The shift in these FTIR absorptions suggest that the HPA particles strongly interact with both the sulfonic acid groups in the PSSA domains and the hydroxyl groups in the PHEA domains. When the weight fraction of HPA was increased to 0.2, the room‐temperature proton conductivity of the composite membrane increased from 0.048 to 0.065 S/cm, presumably because of the intrinsic conductivity of the HPA particles and the enhanced acidity of the sulfonic acid in the tBC. The water uptake of the composite membranes decreased from 130 to 48% with an increase of the HPA weight fraction to 0.4. The decrease in water uptake is likely a result of the decrease in the number of available water absorption sites because of the hydrogen bonding interaction between the HPA particles and the tBC matrix. Scanning electron microscopy and transmission electron microscopy images showed that the HPA nanoparticles with a diameter of 200–300 nm were uniformly distributed throughout the tBC matrix up to an HPA weight fraction of 0.4. Thermal stability of the composite membranes (decomposition temperature > 400 °C) was enhanced as compared with the pristine tBC membrane, presumably because of the strong specific interaction of the HPA particles with the sulfonic acid and hydroxyl groups. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 691–701, 2008
Aquatic habitat change in the Arkansas river after the development of a lock‐and‐dam commercial navigation system
Authors: Schramm Harold L. , Minnis Richard B. , Spencer Amy B. , Theel Ryan T.
Published: February 2008

The McClellan–Kerr Arkansas River Navigation System (MKARNS), completed in 1971, required the construction of 17 locks and dams and associated navigation works to make the Arkansas and Verdigris Rivers navigable for barge traffic from the Mississippi River to Catoosa, Oklahoma. We used a Geographic Information System to assess habitat changes in the 477‐km portion of this system within Arkansas from 1973 to 1999. Total aquatic area declined by 9% from 42 404 to 38 655 ha. Aquatic habitat losses were 1–17% among pools. Greatest habitat losses occurred in diked secondary channels (former secondary channels with flow reduced by rock dikes) and backwaters adjacent to the main channel. Most of the area of dike pools (aquatic habitat downstream of rock dikes), diked secondary channels and adjacent backwaters were <0.9 m deep. Copyright © 2008 John Wiley & Sons, Ltd.
Spawning habitat of Atlantic salmon and brown trout: general criteria and intragravel factors
Authors: Louhi P. , Mäki‐Petäys A. , Erkinaro J.
Published: February 2008

Generalized habitat criteria for spawning sites of Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) using depth, water velocity and substrate size were created based on published information. In addition, information on critical intragravel conditions for egg development was summarized. Salmon spawned mostly in relatively deep, swift‐velocity habitats (20–50 cm, 35–65 cm s−1), whereas trout selected slightly shallower and slower flowing spawning sites (15–45 cm, 20–55 cm s−1). Salmon and trout preferred pebbles (16–64 mm) for spawning. The minimum oxygen concentration for successful incubation of eggs varies with the developmental stage of eggs, and supply of it may be reduced by deposited fine sediment. Habitat criteria for spawning sites are narrower than those for small juveniles; therefore the use of separate criteria is recommended. In addition to the traditional habitat criteria variables (depth, water velocity, substrate), the critical intragravel factors affecting egg survival should be incorporated in biologically meaningful criteria for spawning habitat modelling. Copyright © 2008 John Wiley & Sons, Ltd.
Logistics, Market Size, and Giant Plants in the Early Twentieth Century: A Global View
Authors: HANNAH LESLIE
Published: February 2008

The businesses of developed Europe—transporting freight by a more advantageous mix of ships, trains, and horses—encountered logistic barriers to trade lower than those in the sparsely populated United States. Economically integrated, compact northwest Europe was a multinational market space larger than the United States, and, arguably, as open to interstate commerce as the contemporary Americandomesticmarket. By the early twentieth century, the First European Integration had enabled its manufacturers to build more than half the world's giant plants—many more than in the United States—as variously required by factor endowments, consumer demand, and scale economies.
The Stability of the Interwar Gold Exchange Standard: Did Politics Matter?
Authors: WANDSCHNEIDER KIRSTEN
Published: February 2008

Economic historians have devoted enormous attention to the collapse of the interwar gold standard. This article proposes a discrete time duration model (using a panel data set of 24 countries for 1928–1936) to analyze how economic and political indicators affected a country's term on the gold standard. High per capita income, international creditor status, and prior hyperinflation increased the probability of continuation. In contrast, democratic regimes left early. Unemployment, sterling group membership, higher inflation, and the experience of banking crises reduced the time a country remained on the gold standard. This study also predicts sample countries' survival probabilities.
Korean Expansion and Decline from the Seventeenth to the Nineteenth Century: A View Suggested by Adam Smith
Authors: HO JUN SEONG , LEWIS JAMES B. , HAN-ROG KANG
Published: February 2008

The first price runs for Korean rice help us develop a Smithian physiocratic model to explain the low, stable prices of the eighteenth century and the rising, volatile prices of the nineteenth. Ownership rights provided incentives, and productivity after 1600 exceeded subsistence to achieve rural commercialization. Infrastructure investment from the late seventeenth century promoted development and prosperity, but declining investment, dysfunctional institutions, bad weather, and a population crash pushed the economy towards subsistence in the nineteenth. Decline saw rice monoculture, inflation, and price volatility even before imperialism's impact. Parallels with China suggest an “East Asian” premodern agricultural model.
Jeans instability in a magneto-radiative dusty plasma
Authors: TSINTSADZE N. L. , CHAUDHARY ROZINA , SHAH H. A. , MURTAZA G.
Published: February 2008

The importance of thermal radiation on the Jeans instability is discussed for a magnetized dusty plasma with gravitational effects. The one-fluid MHD equations are developed by assuming that the entropy of each subsystem of plasma is conserved, when the temperature of the plasma species is non-relativistic. The dispersion relation in this case shows that thermal radiation helps to stabilize the Jeans instability. It is shown that the plasma is stable in a certain range of wavelengths. The magnetic field stabilizes the Jeans instability when the wave propagates across the magnetic field. However, for oblique propagation it is seen that the magnetic field does not stabilize the Jeans instability.
Bewältigungsmuster und psychische Gesundheit
Authors: Lehr Dirk , Schmitz Edgar , Hillert Andreas
Published: February 2008

Zusammenfassung. Ziel der Studie war es, die gesundheitliche Relevanz von Mustern der habituellen Stressbewältigung zu untersuchen. Dies geschah auf der Grundlage des Flexibilitätskonzepts, welches die Balance, Breite und Ausgewogenheit des individuellen Bewältigungsrepertoires in den Fokus der Betrachtung stellt. In einer Querschnittsstudie wurde die habituelle Stressbewältigung durch fünf Kurzskalen des Stressverarbeitungsfragebogens (SVF) und eine neu entwickelte Skala zum Aufsuchen positiver Erlebensinhalte erfasst. Weitere sechs Parameter dienten der Beurteilung des Gesundheitsstatus. Die Stichprobe umfasste 145 Lehrkräfte, eine Berufsgruppe mit relativ homogenen Belastungen und hoher Beanspruchung. Es wurden hierarchische (Ward) und iterativ partionierende (k-means) Clusteranalysen sowie ANOVAs durchgeführt. Drei reproduzierbare Cluster konnten identifiziert werden: flexibel-kompensierendes, inkonsistent-kompensierendes und ruminativ-selbstisolierendes Bewältigungsmuster. Die Bewältigungsmuster unterschieden sich in klinisch bedeutsamem Ausmaß hinsichtlich ihres Risikos eine psychische Störung aufzuweisen sowie in den Bereichen Depressivität, Burnout, Arbeitszufriedenheit, Wohlbefinden und subjektive Erwerbstätigkeitsprognose. Die Ergebnisse legen nahe, in Forschungsarbeiten zur betrieblichen Gesundheitsförderung verstärkt differenzielle Muster der Stressbewältigung zu fokussieren.