bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Characterization of Hexathiophenes with Methylthienyl Side Chains
Authors: Saini Geeta , Jacob Josemon 
Published: January 2011

AbstractSummary: Two novel conjugated isomeric hexathiophenes 6T1 and 6T2 bearing 5‐methyl‐2‐thienyl substituents have been synthesized by Suzuki coupling and oxidative dimerization method. These isomers were characterized by 1H NMR, 13C NMR, elemental and mass analysis. The two hexamers show good solubility in common solvents and show almost identical UV‐vis absorption spectra in solution with a maximum cantered at 387 nm. These materials bearing thienyl substituents in the sidechain are anticipated to provide better charge transport in devices and hold promise for use in organic field effect transistors.
The british clearing banks and north sea financing
Authors: Baird R. G. 
Published: January 2011

AbstractThis article reviews available data on North Sea financing with respect to the provision of funds for the offshore exploration and development effort of the oil companies, and for the onshore components suppliers and service companies. In particular it examines the role of the British clearing banks and the changes induced in their lending techniques and habits by the demands of the oil industry. It concludes that financial provision has been adequate and that neither the pace of oil development nor the participation of British industry in the offshore markets has suffered for lack of ready funding.
An analysis of the economic impact of north sea oil activity on the scottish economy in 1973
Authors: Al‐Ali H. M. , Burdekin R. 
Published: January 2011

AbstractThere was no production of crude oil and natural gas in 1973. However, exploration and preparatory production work were well underway. The paper examines the impact within Scotland in 1973 of the expenditure required to supply these activities. The data used for the study are those contained in or associated with the 1973 Scottish Input Output tables and the analysis uses input‐output techniques. The pattern of crude oil consumption within the Scottish economy in 1973 is also examined.
The role of entry barriers in the development of the offshore supply sector in scotland
Authors: Moar Lyle 
Published: January 2011

AbstractThis paper examines the offshore oil supply sector and shows how the entry barriers experienced by new supply firms are imposed not by other supply firms but by the oil companies. This is done to ensure product quality and reliability of service rather than the more general attention to price considerations. The range of entry barriers are discussed in relation to key characteristics of the oil industry. As a spin‐off this experience appears to have generated a more responsive attitude towards technological and commercial change throughout Scottish industry.
The impact of oil on the shetland economy
Authors: McNicoll I. H. 
Published: January 2011

AbstractThis paper uses input‐output analysis to measure the impact of oil supply bases and oil construction on the economy of Shetland. The output, income and employment created in each local industry by oil activities is measured. Oil industry multipliers are derived. Possible negative effects of oil on the local economy are considered. Finally, a forecast is made of the impact of oil on the Shetland economy in 1985.
Why should firms manufacture retailer brands?
Authors: Morris David , Nightingale John 
Published: January 2011

AbstractFor firms manufacturing convenience goods there are three branding policies available, a proprietory brand policy, a retailer brand policy and a mixed brand policy. A firm's choice depends on differences in demand and promotion costs between the proprietory and retailer brand markets. This can be analysed using a simple elaboration of the standard 3rd degree price discrimination model. But if the two markets are not independent over the long‐term there may be other consequences of following the optimization rules of the model. If retailers develop consumers' preference for their own shops and their own brands, the demand advantage enjoyed by manufacturers' brands may be reduced further. The more willing are manufacturers to supply retailer brands, the more retailers win undermine the demand for manufacturers' proprietory brands.
Foreign capital inflows, domestic savings and the price of political stability in the sudan: Weisskopf revisited
Authors: Henley John S. , Droucopoulos Vassilis , Ibrahim Mohamed A. 
Published: January 2011

AbstractThis paper reworks Weisskopf's estimates of the effect of foreign capital inflow on domestic savings for a later time period. The Sudan is presented as an example of a public sector dominated economy, dependent on one major export crop and politically unstable. While Weisskopf's savings function had an indication of a negative relationship between public sector savings and official foreign capital inflow, problems of collinearity between the independent variables cast doubt on its utility for analysis of economies dependent on limited primary exports. The negative relationship between public sector savings and official is explained in terms of the expansion of the state's bureaucracy and military.
Share‐ownership schemes for employees – proposals and prospects
Authors: White P. J. 
Published: January 2011

AbstractRecent statutory and other developments in the United Kingdom seem to have stimulated the introduction of share‐ownership schemes for employees. This article considers the merits of such schemes, and their potential role within companies. The article also points up some weaknesses in the 1978 Finance Act, and suggests the need for caution on the part of those in industry who might contemplate the introduction of share‐ownership arrangements.
Identification of glucosinolate congeners able to form DNA adducts and to induce mutations upon activation by myrosinase
Authors: Baasanjav‐Gerber Chimgee , Monien Bernhard Hans , Mewis Inga , Schreiner Monika , Barillari Jessica , Iori Renato , Glatt Hansruedi 
Published: January 2011

AbstractScope: Juices from Brassicales are mutagenic in Salmonella typhimurium and characteristic adducts are formed with the endogenous DNA in Brassicales homogenates. These effects require myrosinase activity, suggesting an involvement of breakdown products of glucosinolates (GLs). We aimed to identify GLs congeners producing these effects.Methods and results: We investigated twelve individual GLs for mutagenicity in S. typhimurium TA104 and TA100 and for adduct formation with herring sperm DNA using the 32P‐postlabelling/thin‐layer chromatography method. All bacteriotoxic and mutagenic effects observed required the presence of myrosinase. Neoglucobrassicin, 4‐methoxyglucobrassicin and sinalbin showed mutagenicity over wide concentration ranges, with neoglucobrassicin being the most potent congener. Six other GLs led to modest increases in the number of revertants in a small concentration range, before toxicity overshadowed this effect. The remaining three GLs showed some toxicity, but no mutagenicity. However, all twelve GLs formed DNA adducts. Clearly the highest adduct levels were detected with the indole GLs tested. They matched the major adduct spots formed in Brassicales homogenates.Conclusion: The observation that GLs are genotoxic demands follow‐up studies on possible genotoxic and carcinogenic effects of these common food compounds in animal models and humans. Our study may be used to prioritize the congeners in further studies.
Redox‐sensitive proteome and antioxidant strategies in wheat seed dormancy control
Authors: Bykova Natalia V. , Hoehn Brenda , Rampitsch Christof , Banks Travis , Stebbing Jo‐Ann , Fan Tao , Knox Ron 
Published: January 2011

AbstractOxidative signalling by ROS has been demonstrated to play a role in seed dormancy alleviation, but the detailed molecular mechanisms underlying this process remain largely unknown. Here, we show dynamic differences in redox‐sensitive proteome upon wheat seed dormancy release. Using thiol‐specific fluorescent labelling, solubility‐based protein fractionation, 2‐D IEF PAGE, and MS analysis in conjunction with wheat EST sequence libraries, proteins with reversible oxidoreductive changes were characterized. Altogether, 193 reactive Cys were found in 79 unique proteins responding differentially in dormant, non‐dormant, abscisic, or gibberellic acid‐treated seed protein extracts from RL4137, a wheat cultivar with extreme dormancy. The identified proteins included groups that are redox‐, stress‐, and pathogen‐responsive, involved in protein synthesis and storage, are enzymes of carbohydrate metabolism, proteases, and those involved in transport and signal transduction. Two types of redox response could be detected: (i) a dramatic increase in protein thiol redox state in seeds during imbibition and hormonal treatment; (ii) higher antioxidant capacity related to sensing of a threshold redox potential and balancing the existing redox pools, in dry dormant versus non‐dormant seeds. These results highlight occurrence of the antioxidant defence mechanisms required for the protection of seed during a dormancy stage.
Tyrosine 656 in topoisomerase IIβ is important for the catalytic activity of the enzyme: Identification based on artifactual +80‐Da modification at this site
Authors: Grozav Adrian G. , Willard Belinda B. , Kozuki Toshiyuki , Chikamori Kenichi , Micluta Marius A. , Petrescu Andrei‐Jose , Kinter Michael , Ganapathi Ram , Ganapathi Mahrukh K. 
Published: January 2011

AbstractTopoisomerase (topo) II catalyzes topological changes in DNA. Although both human isozymes, topo IIα and β are phosphorylated, site‐specific phosphorylation of topo IIβ is poorly characterized. Using LC‐MS/MS analysis of topo IIβ, cleaved with trypsin, Arg C or cyanogen bromide (CNBr) plus trypsin, we detected four +80‐Da modified sites: tyr656, ser1395, thr1426 and ser1545. Phosphorylation at ser1395, thr1426 and ser1545 was established based on neutral loss of H3PO4 (−98 Da) in the CID spectra and on differences in 2‐D‐phosphopeptide maps of 32P‐labeled wild‐type (WT) and S1395A or T1426A/S1545A mutant topo IIβ. However, phosphorylation at tyr656 could not be verified by 2‐D‐phosphopeptide mapping of 32P‐labeled WT and Y656F mutant protein or by Western blotting with phosphotyrosine‐specific antibodies. Since the +80‐Da modification on tyr656 was observed exclusively during cleavage with CNBr and trypsin, this modification likely represented bromination, which occurred during CNBr cleavage. Re‐evaluation of the CID spectra identified +78/+80‐Da fragment ions in CID spectra of two peptides containing tyr656 and tyr711, confirming bromination. Interestingly, mutation of only tyr656, but not ser1395, thr1326 or ser1545, decreased topo IIβ activity, suggesting a functional role for tyr656. These results, while identifying an important tyrosine in topo IIβ, underscore the importance of careful interpretation of modifications having the same nominal mass.
Layered electrophoretic transfer – A method for pre‐analytic processing of histological sections
Authors: Zhu Liang , Tangrea Michael A. , Mukherjee Sumana , Emmert‐Buck Michael R. 
Published: January 2011

AbstractCurrent technologies for measuring protein expression across a tissue section are based on MS or in situ detection such as immunohistochemistry. However, due to the inherent molecular complexity of tissue samples and the large dynamic range of protein expression in cells, current approaches are often unable to measure moderate‐ and low‐abundant proteins. In addition, they do not provide information on the physico‐chemical properties of the proteins studied. To address these problems, we are developing a new pre‐analytic methodology termed layered electrophoretic transfer (LET) that selectively separates and processes proteins from an intact tissue section without compromising important two‐dimensional histological information. LET offers two potential advantages over standard techniques: (i) A reduced complexity of the tissue proteome for subsequent analysis; (ii) An opportunity to assess the biochemical status of proteins as they exist in situ. As an initial proof‐of‐concept, we demonstrate here that the protein content from a mixture of molecular weight standards, human tissue lysates, and tissue sections can be successfully transferred and separated using LET, and further demonstrate that the method can be coupled with immunoblotting or MS for downstream measurements. LET technology represents a new pre‐analytic tool for interrogating the proteome in tissue sections while preserving valuable spatial information.
Evaluation of absolute peptide quantitation strategies using selected reaction monitoring
Authors: Campbell James , Rezai Taha , Prakash Amol , Krastins Bryan , Dayon Loïc , Ward Malcolm , Robinson Sarah , Lopez Mary 
Published: January 2011

AbstractThe use of internal peptide standards in selected reaction monitoring experiments enables absolute quantitation. Here, we describe three approaches addressing calibration of peptide concentrations in complex matrices and assess their performance in terms of trueness and precision. The simplest approach described is single reference point quantitation where a heavy peptide is spiked into test samples and the endogenous analyte quantified relative to the heavy peptide internal standard. We refer to the second approach as normal curve quantitation. Here, a constant amount of heavy peptide and a varying amount of light peptide are spiked into matrix to construct a calibration curve. This accounts for matrix effects but due to the presence of endogenous analyte, it is usually not possible to determine the lower LOQ. We refer to the third method as reverse curve quantitation. Here, a constant amount of light peptide and a varying amount of heavy peptide are spiked into matrix to construct a calibration curve. Because there is no contribution to the heavy peptide signal from endogenous analyte, it is possible to measure the equivalent of a blank sample and determine LOQ. These approaches are applied to human plasma samples and used to assay peptides of a set of apolipoproteins.
A comparison of MS2‐based label‐free quantitative proteomic techniques with regards to accuracy and precision
Authors: Colaert Niklaas , Vandekerckhove Joël , Gevaert Kris , Martens Lennart 
Published: January 2011

AbstractThe advent of algorithms for fragmentation spectrum‐based label‐free quantitative proteomics has enabled straightforward quantification of shotgun proteomic experiments. Despite the popularity of these approaches, few studies have been performed to assess their performance. We have therefore profiled the precision and the accuracy of three distinct relative label‐free methods on both the protein and the proteome level. We derived our test data from two well‐characterized publicly available quantitative data sets.
Efficient proteolysis using a regenerable metal‐ion chelate immobilized enzyme reactor supported on organic–inorganic hybrid silica monolith
Authors: Ma Junfeng , Hou Chunyan , Liang Yu , Wang Tingting , Liang Zhen , Zhang Lihua , Zhang Yukui 
Published: January 2011

AbstractA metal‐ion chelate immobilized enzyme reactor (IMER) supported on organic–inorganic hybrid silica monolith was developed for rapid digestion of proteins. The monolithic support was in situ prepared in a fused silica capillary via the polycondensation between tetraethoxysilane hydrolytic sol and iminodiacetic acid conjugated glycidoxypropyltrimethoxysilane. After activated by Cu2+, trypsin was immobilized onto the monolithic support via metal chelation. Proteolytic capability of such an IMER was evaluated by the digestion of myoglobin and BSA, and the digests were further analyzed by microflow reversed‐phase liquid chromatography with ESI‐MS/MS. Similar sequence coverages of myoglobin and BSA were obtained by IMER, in comparison to those obtained by in‐solution digestion (91 versus 92% for 200 ng myoglobin, and 26 versus 26% for 200 ng BSA). However, the digestion time was shortened from 12 h to 50 s. When the enzymatic activity was decreased after seven runs, the IMER could be easily regenerated by removing Cu2+ via EDTA followed by trypsin immobilization with fresh Cu2+ introduced, yielding the equal sequence coverage (26% for 200 ng BSA). For ∼5 μg rat liver extract, even more proteins were identified with the immobilized trypsin digestion within 150 s in comparison to the in‐solution digestion for 24 h (541 versus 483), demonstrating that the IMER could be a promising tool for efficient and high‐throughput proteome profiling.
Less label, more free: Approaches in label‐free quantitative mass spectrometry
Authors: Neilson Karlie A. , Ali Naveid A. , Muralidharan Sridevi , Mirzaei Mehdi , Mariani Michael , Assadourian Gariné , Lee Albert , van Sluyter Steven C. , Haynes Paul A. 
Published: January 2011

AbstractIn this review we examine techniques, software, and statistical analyses used in label‐free quantitative proteomics studies for area under the curve and spectral counting approaches. Recent advances in the field are discussed in an order that reflects a logical workflow design. Examples of studies that follow this design are presented to highlight the requirement for statistical assessment and further experiments to validate results from label‐free quantitation. Limitations of label‐free approaches are considered, label‐free approaches are compared with labelling techniques, and forward‐looking applications for label‐free quantitative data are presented. We conclude that label‐free quantitative proteomics is a reliable, versatile, and cost‐effective alternative to labelled quantitation.
Simulating and validating proteomics data and search results
Authors: Geromanos Scott J. , Hughes Chris , Golick Dan , Ciavarini Steven , Gorenstein Marc V. , Richardson Keith , Hoyes John B. , Vissers Johannes P.C. , Langridge James I. 
Published: January 2011

AbstractThe computational simulation of complete proteomic data sets and their utility to validate detection and interpretation algorithms, to aid in the design of experiments and to assess protein and peptide false discovery rates is presented. The simulation software has been developed for emulating data originating from data‐dependent and data‐independent LC‐MS workflows. Data from all types of commonly used hybrid mass spectrometers can be simulated. The algorithms are based on empirically derived physicochemical liquid and gas phase models for proteins and peptides. Sample composition in terms of complexity and dynamic range, as well as chromatographic, experimental and MS conditions, can be controlled and adjusted independently. The effect of on‐column amounts, gradient length, mass resolution and ion mobility on search specificity will be demonstrated using tryptic peptides from human and yeast cellular lysates simulated over five orders of magnitude in dynamic range. Initial justification of the simulated data sets is achieved by comparing and contrasting the in silico simulated data to experimentally derived results from a 48 protein mixture, spanning a similar magnitude of five orders of magnitude. Additionally, experimental data from replicate and dilutions series experiments will be utilized to determine error rates at the peptide and protein level with respect to mass, area, retention and drift time. The data presented reveal a high degree of similarity at the ion detection, peptide and protein level when analyzed under similar conditions.
The endosomal proteome of macrophage and dendritic cells
Authors: Duclos Sophie , Clavarino Giovanna , Rousserie Gilles , Goyette Guillaume , Boulais Jonathan , Camossetto Voahirana , Gatti Evelina , LaBoissière Sylvie , Pierre Philippe , Desjardins Michel 
Published: January 2011

AbstractThe essential roles of the endovacuolar system in health and disease call for the development of new tools allowing a better understanding of the complex molecular machinery involved in endocytic processes. We took advantage of the floating properties of small latex beads (sLB) on a discontinuous sucrose gradient to isolate highly purified endosomes following internalization of small latex beads in J774 macrophages and bone marrow‐derived dendritic cells (DC). We particularly focused on the isolation of macrophages early endosomes and late endosomes/lysosomes (LE/LYS) as well as the isolation of LE/LYS from immature and lipopolysaccharide‐activated (mature) DC. We subsequently performed a comparative analysis of their respective protein contents by MS. As expected, proteins already known to localize to the early endosomes were enriched in the earliest fraction of J774 endosomes, while proteins known to accumulate later in the process, such as hydrolases, were significantly enriched in the LE/LYS preparations. We next compared the LE/LYS protein contents of immature DC and mature DC, which are known to undergo massive reorganization leading to potent immune activation. The differences between the protein contents of endocytic organelles from macrophages and DC were underlined by focusing on previously poorly characterized biochemical pathways, which could have an unexpected but important role in the endosomal functions of these highly relevant immune cell types.
Quality control in LC‐MS/MS
Authors: Köcher Thomas , Pichler Peter , Swart Remco , Mechtler Karl 
Published: January 2011

AbstractIn the last 15 years, MS‐based protein characterization has expanded at a rapid rate. This success is built upon constantly improving instrumentation and a variety of ingenious methods applied to numerous biological questions. However, the reproducibility of mass spectrometric results is considered by many as insufficient. In part, inadequate quality control might be responsible for the lack of reproducibility. Quality control is rarely discussed in scientific publications. Here, we briefly present measures undertaken in our laboratory to foster a general discussion of the subject.
Statistical issues in quality control of proteomic analyses: Good experimental design and planning
Authors: Cairns David A. 
Published: January 2011

AbstractQuality control is becoming increasingly important in proteomic investigations as experiments become more multivariate and quantitative. Quality control applies to all stages of an investigation and statistics can play a key role. In this review, the role of statistical ideas in the design and planning of an investigation is described. This involves the design of unbiased experiments using key concepts from statistical experimental design, the understanding of the biological and analytical variation in a system using variance components analysis and the determination of a required sample size to perform a statistically powerful investigation. These concepts are described through simple examples and an example data set from a 2‐D DIGE pilot experiment. Each of these concepts can prove useful in producing better and more reproducible data.