bluuebunny/crossref_metadata_2025_split huggingface dataset:
Strong correlation between summer temperature and pollen accumulation rates for Pinus sylvestris, Picea abies and Betula spp. in a high‐resolution record from northern Sweden
Authors: Barnekow L. , Loader N. J. , Hicks S. , Froyd C. A. , Goslar T. 
Published: March 2007

AbstractHighly resolved pollen spectra analysed from a 47 cm peat monolith recovered from a mire in northern Sweden exhibit climatic sensitivity in the pollen accumulation rates (PAR) of boreal treeline species. Robust temporal control, afforded through multiple AMS radiocarbon dating of the post‐atomic‐bomb‐test period (AD 1961–2002), provides a unique opportunity to compare pollen accumulation rates with the instrumental meteorological record. Strong correlations are observed between summer temperature and PAR for Pinus sylvestris, Picea abies and Betula spp. (excluding B. nana). Despite well constrained, contiguous (‘annual’) sampling, the temporal resolution of the pollen signal preserved within each sample appears to be degraded to ca. 3–5 year resolution. This is likely to reflect processes occurring during peat accumulation and pollen deposition, as well as dating uncertainties and the effects of subsampling. These findings identify limitations to the maximum resolution that may realistically be recovered from the peat archive using high‐resolution sampling protocols and AMS 14C dating. We also identify the need for additional work to quantify the role of climate on peat accumulation and the resultant impact on assemblage‐based palaeoenvironmental reconstructions within mire sequences. The strongest climate association observed for Picea abies (r = 0.53; n = 36) was extended through the monolith beyond the 42 year period of ‘annual’ sampling and the response successfully correlated with the Bottenviken historical instrumental record to AD 1860. Although only presenting data from a single site, and requiring wider replication, we conclude that for sites close to the ecological limits of tree species, where levels of anthropogenic/non‐climatic forcing on pollen production are low, well‐dated records of PAR may potentially provide a proxy for reconstructing past summer temperature variability. Copyright © 2007 John Wiley & Sons, Ltd.
Existence of EF‐equivalent non‐isomorphic models
Authors: Havlin Chanoch , Shelah Saharon 
Published: March 2007

AbstractWe prove the existence of pairs of models of the same cardinality λ which are very equivalent according to EF games, but not isomorphic. We continue the paper [4], but we do not rely on it. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Development of an enzyme immunoassay to detect and quantify psoralen and bergapten in plants
Authors: Bourgaud F. , Bouque V. , Marchal S. , Innocenti G. , Dall'Acqua F. , Guckert A. 
Published: March 2007

AbstractA competitive enzyme immunoassay has been developed in order to quantify furanocoumarins. 5‐Hydroxypsoralen was modified and linked to bovine serum albumin to obtain an antigenic response. The rabbit serum that was collected was highly specific to 5‐methoxypsoralen and psoralen but did not recognize angelicin (a psoralen angular isomer), 8‐methoxypsoralen or 5,8‐dimethoxypsoralen, coumarin and related molecules. The detection limit was about 5 ng/mL for 5‐methoxypsoralen and 30 ng/mL for psoralen. The test was applied to plants that contain furanocoumarins i.e. species of Psoralea. The correlation with a classical high‐pressure liquid chromatographic method was satisfactory with both dry and fresh matter. With reference to the extraction method used with the plant material, the detection limit in the plant samples was about 15 μg/g for the dry matter and 20 μg/g for the fresh matter. This technique is a useful tool to detect and quantify psoralen and 5‐methoxypsoralen in plant samples.
Methods for the purification of ubiquitinated Proteins
Authors: Tomlinson Emma , Palaniyappan Naaventhan , Tooth David , Layfield Robert 
Published: March 2007

AbstractPost‐translational protein modification by the covalent conjugation of ubiquitin, originally implicated as a signal for proteolytic degradation by 26S proteasome, has now been realised to play important roles in the regulation of almost all biological processes in eukaryotes. In order to understand these processes in greater detail there is a requirement for techniques that can purify mixtures of ubiquitin‐conjugated proteins, as a prerequisite to their identification and characterisation. Here we review the methods that have been applied to the bulk purification of ubiquitinated proteins and discuss their applications in proteomic analyses of the ‘ubiquitome’.
Synthesis, characterization, and biodegradation of copolymers of unsaturated and saturated poly(ester amide)s
Authors: Guo Kai , Chu C. C. 
Published: March 2007

AbstractA new family of biodegradable copolymers of unsaturated poly(ester amide)s (UPEAs) and saturated poly(ester amide)s (SPEAs) based on L‐phenylalanine, aliphatic dicarboxylic acids, and aliphatic dialcohols was synthesized by solution polycondensation and characterized. These unsaturated/saturated poly(ester amide) copolymers (USPEAs) were obtained in fairly good yields with N,N‐dimethylacetamide as the solvent. The molecular weights (Mn and Mw) of the USPEAs measured by GPC ranged from 15 to 60 kg/mol with a molecular weight distribution of 1.07–1.63. The chemical structures of the USPEAs were confirmed by both IR and NMR spectra. The USPEA copolymers had glass transition temperatures lower than that of pure UPEA but higher than that of pure SPEA. An increase in the unsaturated component in the USPEA copolymers led to an increase in their glass transition temperatures. The solubility of the copolymers was good in N,N‐dimethylacetamide and dimethyl sulfoxide but poor in water, acetone, methanol, and ethyl acetate. The preliminary in vitro biodegradation properties of the USPEA copolymers were investigated in both pure phosphate buffered saline (PBS) buffer and α‐chymotrypsin solutions. The copolymers showed significantly faster weight loss in an enzyme solution than in a pure PBS buffer. Upon the adjustment of the unsaturated‐to‐saturated diester monomer feed ratio, the obtained USPEA copolymers could have controlled chemical and physical properties, such as glass transition temperatures, solubility, and biodegradability, which could easily extend their applications to biomedical and pharmaceutical areas. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1595–1606, 2007
Combined effects of conjugation pattern and alkoxy side chains on the photovoltaic properties of thiophene‐containing PPE‐PPVs
Authors: Ayuk Mbi Egbe Daniel , Nguyen Le Huong , Schmidtke Kathy , Wild Andreas , Sieber Christoph , Guenes Serap , Serdar Sariciftci Niyazi 
Published: March 2007

AbstractThis contribution presents the synthesis and properties of four thiophene‐containing poly(‐p‐arylene‐ethynylene)/poly(‐p‐arylene‐vinylene)s, PIa‐b and PIIa‐b, whose repeating units (RU) consist either of 1:2 or 2:2 triple bond/double bond ratio, and which bear linear alkoxy side chains not longer than octyloxy and branched 2‐ethylhexyloxy. PIa‐b and PIIa‐b exhibit similar absorption and emission behaviour in dilute solution (λa = 483–486 nm, λe = 540 nm) as well as in solid state (λa = 500, 530 nm, λe = 560 nm), whereby slightly higher fluorescence quantum yields (Φf) were obtained for PI than for PII systems, as a result of higher number of thiophene units within the RU of PII. An enhancement of the Φf‐value from 0% to 3% is obtained after replacing linear octadecyloxy in PIIc‐e by bulky branched 2‐ethylhexyloxy in PIIa‐b. Nonoptimized solar cells of configuration ITO/PEDOT:PSS/polymer: PCBM (1:3 weight ratio)/LiF/Al show open circuit voltages as high as 900 mV for PIa‐b and 800 mV for PIIa‐b. Reducing the size of the side chain from R = 2‐ethylhexyl in PIa to R = methyl in PIb leads to a significant increase of the short circuit current, ISC, from ca. 2.5 mA to ca. 3.7 mA and consequently to an enhancement of the energy conversion efficiency, ηAM1.5, from ca. 1.2% to ca. 1.7%. This is due to an extended donor‐acceptor interfacial area, as evidenced by AFM topology pictures showing smaller nanoscale clusters size in PIb than in PIa active layer. The same change led to minimal effect in PII systems. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1619–1631, 2007
Block copolymers of dodecafluoroheptyl methacrylate and butyl methacrylate by RAFT miniemulsion polymerization
Authors: Qinghua Zhang , Xiaoli Zhan , Fengqiu Chen , Ying Shi , Qiongyan Wang 
Published: March 2007

AbstractReversible addition‐fragmentation chain transfer (RAFT) miniemulsion polymerization of butyl methacrylate (BMA) and dodecafluoroheptyl methacrylate (DFMA) was carried out with 2‐cyanoprop‐2‐yl dithiobenzoate (CPDB) as chain transfer agent (CTA). Concentration effects of RAFT agent and initiator on kinetics and molecular weight were investigated. No obvious red oil layer (phase's separation) and coagulation was observed in the first stage of homopolymerization of BMA. The polymer molecular weights increased linearly with the monomer conversion with polydispersities lower than 1.2. At 75 °C, the monomer conversion could achieve above 96% in 3 h with [momomer]:[RAFT]:[KPS] = 620:4:1 (mole ratio). The results showed excellent controlled/living polymerization characteristics and a very fast polymerization rate. Furthermore, the synthesis of poly(BMA‐b‐DFMA) diblock copolymers with a regular structure (PDI < 1.30, PMMA calibration) was performed by adding the monomer of DFMA at the end of the RAFT miniemulsion polymerization of BMA. The success of diblock copolymerization was showed by the molecular weight curves shifting toward higher molar mass, recorded by gel permeation chromatography before and after block copolymerization. Compositions of block copolymers were further confirmed by 1H NMR, FTIR, and DSC analysis. The copolymers exhibited a phase‐separated morphology and possessed distinct glass transition temperatures associated with fluoropolymer PDFMA and PBMA domains. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1585–1594, 2007
Biomarkers in drug development: friend or foe? A personal reflection gained working within oncology
Authors: Carroll Kevin J. 
Published: March 2007

AbstractHopes and expectations for the use and utility of new, emerging biomarkers in drug development have probably never been higher, especially in oncology. Biomarkers are exalted as vital patient selection tools in an effort to target those most likely to benefit from a new drug, and so to reduce development costs, lessen risk and expedite developments times. It is further hoped that biomarkers can be used as surrogate endpoints for clinical outcomes, to demonstrate effectiveness and, ultimately, to support drug approval. However, I perceive that all is not straightforward, and, particularly in terms of the promise of accelerated drug development, biomarker strategies may not in all cases deliver the advances and advantages hoped for. Copyright © 2007 John Wiley & Sons, Ltd.
Direct mass spectrometric analysis of flavors and fragrances in real applications using DART
Authors: Haefliger Olivier P. , Jeckelmann Nicolas 
Published: March 2007

AbstractDART (Direct Analysis in Real Time) is an innovative technology to analyze complex solid samples at atmospheric pressure and ground potential by simply placing them between a DART ion source and a mass spectrometer. The analytes are ionized by a gun of neutral metastable species. The first examples of the application of DART to the analysis of flavor and fragrance raw materials in real, complex applications are reported here. A remarkably high potential of the technique is demonstrated. DART was applied to semi‐quantitative analyses of perfumery raw materials deposited on smelling strips. In optimal cases, limits of detection around 100 pg were achieved. DART also allowed the assessment of the deposition and release of fragrance on surfaces such as fabric and hair. Finally, DART permitted the screening of twelve chewing gum samples for the possible presence of taste‐refreshing compounds in less than 30 min. Copyright © 2007 John Wiley & Sons, Ltd.
The influence of river regulation and land use on floodplain forest regeneration in the semi‐arid upper Colorado River Basin, USA
Authors: Northcott Krista , Andersen Douglas C. , Cooper David J. 
Published: March 2007

AbstractFlow regulation effects on floodplain forests in the semi‐arid western United States are moderately well understood, whereas effects associated with changes in floodplain land use are poorly documented. We mapped land cover patterns from recent aerial photos and applied a classification scheme to mainstem alluvial floodplains in 10 subjectively selected 4th order hydrologic units (subbasins) in the Upper Colorado River Basin (UCRB) in order to document land use patterns (floodplain development) and assess their effects on Fremont cottonwood forest (CF) regeneration. Three of the mainstem rivers were unregulated, five were moderately regulated and two were highly regulated. We classified polygons as Undeveloped (with two categories, including CF) and Developed (with five categories). We ground‐truthed 501 randomly selected polygons (4–28% of the floodplain area in each subbasin) to verify classification accuracy and to search for cottonwood regeneration, defined as stands established since regulation began or 1950, whichever is most recent. From 40% to 95% of the floodplain area remained undeveloped, but only 19–70% of the floodplain area was classified as forest. Regeneration occupied a mean of 5% (range 1–17%) of the floodplain. The likelihood of the presence of regeneration in a polygon was reduced 65% by development and independently in a complex manner by flow regulation. Our analyses indicate that floodplain forests may be in jeopardy on both regulated and unregulated rivers and that information on historical forest extent is needed to better understand their current status in the UCRB. Conservation efforts need to be coordinated at a regional level and address the potentially adverse affects of both flow regulation and floodplain development. Published in 2007 by John Wiley & Sons, Ltd.
Osmoresistant yeast Zygosaccharomyces rouxii: the two most studied wild‐type strains (ATCC 2623 and ATCC 42981) differ in osmotolerance and glycerol metabolism
Authors: Pribylova Lenka , de Montigny Jacky , Sychrova Hana 
Published: March 2007

AbstractThe yeast Zygosaccharomyces rouxii is known for its high tolerance to osmotic stress, which is thought to be caused by sets of specific genes. Relatively few Z. rouxii genes have been identified so far, all of them having homologues in Saccharomyces cerevisiae; none of them was Z. rouxii‐specific. Most of the known Z. rouxii genes were isolated from two wild‐type strains, ATCC 2623 and ATCC 42981. In this study, we compared these two strains with regard to some of their morphological, physiological and genomic properties. Important differences were found in their salt tolerance and assimilation of glycerol and karyotype; slight differences were also present in their cell morphology. The ATCC 42981 strain showed a higher resistance to salts, higher glycerol production and, unlike ATCC 2623, was able to assimilate glycerol. Under conditions of osmotic stress, the glycerol production in both Z. rouxii strains was much lower than in a S. cerevisiae S288c culture, which suggested the presence of a system that efficiently retains glycerol inside Z. rouxii cells. The karyotype analysis revealed that ATCC 42981 cells contain more chromosomes and have a bigger genome size than those of ATCC 2623. Copyright © 2007 John Wiley & Sons, Ltd.
Attenuation of stress-induced anorexia in brown trout (Salmo trutta) by pre-treatment with dietaryl-tryptophan
Authors: Höglund Erik , Sørensen Christina , Bakke Marit Jørgensen , Nilsson Göran E. , Øverli Øyvind 
Published: March 2007

The general consensus is that brain serotonin (5-HT) inhibits feed intake in teleost fishes and other vertebrates. Dietary manipulations with the 5-HT precursor tryptophan (TRP) have, however, yielded contradictory effects on feed intake, while studies of the endocrine response to stress indicate that the effects of TRP-enriched feed are context dependent. A characteristic behavioural response to stress is a reduction in feed intake, and in the present study we investigated whether pre-treatment with TRP-enriched feed affected stress-induced changes in feeding behaviour in brown trout (Salmo trutta). After acclimatisation in observation aquaria, isolated fish were fed control or TRP-supplemented feed for 7 d, whereupon they were transferred to a novel environment, in which all fish were fed control feed. Transfer to a new environment resulted in decreased feeding in both the TRP pre-treated and the control-treated group. However, this decrease was more pronounced in the control-treated group. Previous experiments have concluded that stimulation of brain 5-HT systems by TRP enhancement does not affect feed intake in salmonid fishes, but in these studies food intake was observed in unstressed animals only. The present study suggests that pre-treatment with dietary TRP attenuates stress-induced anorexia. Hence, it appears that the effect of dietary manipulations of TRP on feeding behaviour is dependent on the stress levels experienced by experimental animals. These behavioural data are discussed in the context of the involvement of 5-HT in appetite regulation.
CICERO AND THE TREVERI: NEW LIGHT ON AN OLD PUN
Authors: SHOTTER DAVID 
Published: March 2007

Sed, ut ego quoque te aliquid admoneam de vestris cautionibus, Treveros vites censeo: audio capitales esse: mallem auro, argento, aere essent.However, if I may give you a caveat from your own legal arsenal, I advise you to keep clear of the Treveri: I hear that they are deadly customers, like their Roman namesakes. If you want a Board of Three, better try the Masters of the Mint.The letter, from which this passage is taken, is one of a number that passed between Cicero and a young lawyer, Gaius Trebatius Testa, who was serving with Julius Caesar's army in Gaul in the late 50s BC.As in most of his letters to Trebatius, Cicero revels in jokes and word-play with a legal flavour which, of course, would have suited this particular recipient. This passage is far from easy to translate adequately into English because it contains a ‘developing’ pun, the full force of which is inevitably lost in translation. The actual structure of the pun, however, is obvious enough: Trebatius' proximity to the tribe of the Treveri leads to a word-play with the Latin word, Tresviri (‘Board of Three’). The fact that the Treveri had a reputation for ferocity in battle causes Cicero to call them ‘deadly’ (capitales) which, in its turn, leads to an implied reference to the Tresviri Capitales, three junior officials in Rome who were in charge of executions and prisons.
Adaptive motion selection for online hand–eye calibration
Authors: Zhang Jing , Shi Fanhuai , Liu Yuncai 
Published: March 2007

SUMMARYWhile a robot moves, online hand–eye calibration to determine the relative pose between the robot gripper/end-effector and the sensors mounted on it is very important in a vision-guided robot system. During online hand–eye calibration, it is impossible to perform motion planning to avoid degenerate motions and small rotations, which may lead to unreliable calibration results. This paper proposes an adaptive motion selection algorithm for online hand–eye calibration, featured by dynamic threshold determination for motion selection and getting reliable hand–eye calibration results. Simulation and real experiments demonstrate the effectiveness of our method.
Discovery of microRNA–mRNA modules via population-based probabilistic learning
Authors: Joung Je-Gun , Hwang Kyu-Baek , Nam Jin-Wu , Kim Soo-Jin , Zhang Byoung-Tak 
Published: March 2007

AbstractMotivation: MicroRNAs (miRNAs) and mRNAs constitute an important part of gene regulatory networks, influencing diverse biological phenomena. Elucidating closely related miRNAs and mRNAs can be an essential first step towards the discovery of their combinatorial effects on different cellular states. Here, we propose a probabilistic learning method to identify synergistic miRNAs involving regulation of their condition-specific target genes (mRNAs) from multiple information sources, i.e. computationally predicted target genes of miRNAs and their respective expression profiles.Results: We used data sets consisting of miRNA–target gene binding information and expression profiles of miRNAs and mRNAs on human cancer samples. Our method allowed us to detect functionally correlated miRNA–mRNA modules involved in specific biological processes from multiple data sources by using a balanced fitness function and efficient searching over multiple populations. The proposed algorithm found two miRNA–mRNA modules, highly correlated with respect to their expression and biological function. Moreover, the mRNAs included in the same module showed much higher correlations when the related miRNAs were highly expressed, demonstrating our method's ability for finding coherent miRNA–mRNA modules. Most members of these modules have been reported to be closely related with cancer. Consequently, our method can provide a primary source of miRNA and target sets presumed to constitute closely related parts of gene regulatory pathways.Contact: btzhang@bi.snu.ac.krSupplementary information: Supplementary data are available at Bioinformatics online.
A Novel Bioinformatics Approach Identifies Candidate Genes for the Synthesis and Feruloylation of Arabinoxylan
Authors: Mitchell Rowan A.C. , Dupree Paul , Shewry Peter R. 
Published: March 2007

Abstract
Arabinoxylans (AXs) are major components of graminaceous plant cell walls, including those in the grain and straw of economically important cereals. Despite some recent advances in identifying the genes encoding biosynthetic enzymes for a number of other plant cell wall polysaccharides, the genes encoding enzymes of the final stages of AX synthesis have not been identified. We have therefore adopted a novel bioinformatics approach based on estimation of differential expression of orthologous genes between taxonomic divisions of species. Over 3 million public domain cereal and dicot expressed sequence tags were mapped onto the complete sets of rice (Oryza sativa) and Arabidopsis (Arabidopsis thaliana) genes, respectively. It was assumed that genes in cereals involved in AX biosynthesis would be expressed at high levels and that their orthologs in dicotyledonous plants would be expressed at much lower levels. Considering all rice genes encoding putative glycosyl transferases (GTs) predicted to be integral membrane proteins, genes in the GT43, GT47, and GT61 families emerged as much the strongest candidates. When the search was widened to all other rice or Arabidopsis genes predicted to encode integral membrane proteins, cereal genes in Pfam family PF02458 emerged as candidates for the feruloylation of AX. Our analysis, known activities, and recent findings elsewhere are most consistent with genes in the GT43 families encoding β-1,4-xylan synthases, genes in the GT47 family encoding xylan α-1,2- or α-1,3-arabinosyl transferases, and genes in the GT61 family encoding feruloyl-AX β-1,2-xylosyl transferases.