bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding the determinants of substrate specificity in IMP family metallo‐β‐lactamases: The importance of residue 262
Authors: Pegg Kevin M. , Liu Eleanor M. , George Alex C. , LaCuran Alecander E. , Bethel Christopher R. , Bonomo Robert A. , Oelschlaeger Peter 
Published: August 2014

AbstractIn Gram‐negative bacteria, resistance to β‐lactam antibacterials is largely due to β‐lactamases and is a growing public health threat. One of the most concerning β‐lactamases to evolve in bacteria are the Class B enzymes, the metallo‐β‐lactamases (MBLs). To date, penams and cephems resistant to hydrolysis by MBLs have not yet been found. As a result of this broad substrate specificity, a better understanding of the role of catalytically important amino acids in MBLs is necessary to design novel β‐lactams and inhibitors. Two MBLs, the wild type IMP‐1 with serine at position 262, and an engineered variant with valine at the same position (IMP‐1‐S262V), were previously found to exhibit very different substrate spectra. These findings compelled us to investigate the impact of a threonine at position 262 (IMP‐1‐S262T) on the substrate spectrum. Here, we explore MBL sequence‐structure‐activity relationships by predicting and experimentally validating the effect of the S262T substitution in IMP‐1. Using site‐directed mutagenesis, threonine was introduced at position 262, and the IMP‐1‐S262T enzyme, as well as the other two enzymes IMP‐1 and IMP‐1‐S262V, were purified and kinetic constants were determined against a range of β‐lactam antibacterials. Catalytic efficiencies (kcat/KM) obtained with IMP‐1‐S262T and minimum inhibitory concentrations (MICs) observed with bacterial cells expressing the protein were intermediate or comparable to the corresponding values with IMP‐1 and IMP‐1‐S262V, validating the role of this residue in catalysis. Our results reveal the important role of IMP residue 262 in β‐lactam turnover and support this approach to predict activities of certain novel MBL variants.
Fault diagnosis in fixed‐block railway signaling systems: a discrete event systems approach
Authors: Durmuş Mustafa S , Takai Shigemasa , Söylemez Mehmet T 
Published: August 2014

AbstractIn conventional railway systems (or fixed‐block railway signaling systems), railway lines are divided into subsections, called railway blocks, which start and end with a signal. In order to prevent collisions, only one train is allowed in each railway block at a time. Since the occupancy of the next block is indicated by the signals, train drivers have to pay attention to the signals during their journey. In spite of the conventional railway systems having several drawbacks such as the reduction in railway line capacity and the same safe braking distances for all kinds of trains, they have been in use since the mid‐1800s. In this paper, we study fault diagnosis in fixed‐block railway signaling systems from the discrete event systems point of view: first the signaling system equipment are modeled by using Petri nets, and next a diagnoser is designed to show the diagnosability of the system. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Gold mining companies and the price of gold
Authors: Baur Dirk G. 
Published: August 2014

AbstractThis paper studies the exposure of Australian gold mining firms to changes in the gold price. We use a theoretical framework to formulate testable hypotheses regarding the gold exposure of gold mining firms. The empirical analysis based on all gold mining firms in the S&P/ASX All Ordinaries Gold Index for the period from January 1980 to December 2010 finds that the average gold beta is around one but varies significantly through time. The relatively low average gold beta is attributed to the hedging and diversification of gold mining firms. We further find an asymmetric effect in gold betas, i.e. the gold exposure increases with positive gold price changes and decreases with negative gold price changes consistent with gold mining companies exercising real options on gold.
The impact of a supermarket nutrition rating system on purchases of nutritious and less nutritious foods
Authors: Cawley John , Sweeney Matthew J , Sobal Jeffery , Just David R , Kaiser Harry M , Schulze William D , Wethington Elaine , Wansink Brian 
Published: August 2014

AbstractObjectiveThe current study examines the impact of a nutrition rating system on consumers’ food purchases in supermarkets.DesignAggregate sales data for 102 categories of food (over 60 000 brands) on a weekly basis for 2005–2007 from a supermarket chain of over 150 stores are analysed. Change in weekly sales of nutritious and less nutritious foods, after the introduction of a nutrition rating system on store shelves, is calculated, controlling for seasonality and time trends in sales.SettingOne hundred and sixty-eight supermarket stores in the north-east USA, from January 2005 to December 2007.SubjectsConsumers purchasing goods at the supermarket chain during the study period.ResultsAfter the introduction of the nutrition ratings, overall weekly food sales declined by an average of 3637 units per category (95 % CI –5961, –1313;P<0·01). Sales of less nutritious foods fell by 8·31 % (95 % CI –13·50, –2·80 %;P=0·004), while sales of nutritious foods did not change significantly (P=0·21); as a result, the percentage of food purchases rated as nutritious rose by 1·39 % (95 % CI 0·58, 2·20 %;P<0·01). The decrease in sales of less nutritious foods was greatest in the categories of canned meat and fish, soda pop, bakery and canned vegetables.ConclusionsThe introduction of the nutrition ratings led shoppers to buy a more nutritious mix of products. Interestingly, it did so by reducing purchases of less nutritious foods rather than by increasing purchases of nutritious foods. In evaluating nutrition information systems, researchers should focus on the entire market basket, not just sales of nutritious foods.
The ambrosia symbiosis is specific in some species and promiscuous in others: evidence from community pyrosequencing
Authors: Kostovcik Martin , Bateman Craig C , Kolarik Miroslav , Stelinski Lukasz L , Jordal Bjarte H , Hulcr Jiri 
Published: August 2014

AbstractSymbioses are increasingly seen as dynamic ecosystems with multiple associates and varying fidelity. Symbiont specificity remains elusive in one of the most ecologically successful and economically damaging eukaryotic symbioses: the ambrosia symbiosis of wood-boring beetles and fungi. We used multiplexed pyrosequencing of amplified internal transcribed spacer II (ITS2) ribosomal DNA (rDNA) libraries to document the communities of fungal associates and symbionts inside the mycangia (fungus transfer organ) of three ambrosia beetle species, Xyleborus affinis, Xyleborus ferrugineus and Xylosandrus crassiusculus. We processed 93 beetle samples from 5 locations across Florida, including reference communities. Fungal communities within mycangia included 14–20 fungus species, many more than reported by culture-based studies. We recovered previously known nutritional symbionts as members of the core community. We also detected several other fungal taxa that are equally frequent but whose function is unknown and many other transient species. The composition of fungal assemblages was significantly correlated with beetle species but not with locality. The type of mycangium appears to determine specificity: two Xyleborus with mandibular mycangia had multiple dominant associates with even abundances; Xylosandrus crassiusculus (mesonotal mycangium) communities were dominated by a single symbiont, Ambrosiella sp. Beetle mycangia also carried many fungi from the environment, including plant pathogens and endophytes. The ITS2 marker proved useful for ecological analyses, but the taxonomic resolution was limited to fungal genus or family, particularly in Ophiostomatales, which are under-represented in our amplicons as well as in public databases. This initial analysis of three beetle species suggests that each clade of ambrosia beetles and each mycangium type may support a functionally and taxonomically distinct symbiosis.
A Cancer-specific Monoclonal Antibody Recognizes the Aberrantly Glycosylated Podoplanin
Authors: Kato Yukinari , Kaneko Mika Kato 
Published: August 2014

AbstractPodoplanin (PDPN/Aggrus/T1α), a platelet aggregation-inducing mucin-like sialoglycoprotein, is highly expressed in many cancers and normal tissues. A neutralizing monoclonal antibody (mAb; NZ-1) can block the association between podoplanin and C-type lectin-like receptor-2 (CLEC-2) and inhibit podoplanin-induced cancer metastasis, but NZ-1 reacts with podoplanin-expressing normal cells such as lymphatic endothelial cells. In this study, we established a cancer-specific mAb (CasMab) against human podoplanin. Aberrantly glycosylated podoplanin including keratan sulfate or aberrant sialylation, which was expressed in LN229 glioblastoma cells, was used as an immunogen. The newly established LpMab-2 mAb recognized both an aberrantO-glycosylation and a Thr55-Leu64 peptide from human podoplanin. Because LpMab-2 reacted with podoplanin-expressing cancer cells but not with normal cells, as shown by flow cytometry and immunohistochemistry, it is an anti-podoplanin CasMab that is expected to be useful for molecular targeting therapy against podoplanin-expressing cancers.
Faster, safer, and better DNA purification by ultracentrifugation using GelRed stain and development of mismatch oligo DNA for genome walking
Authors: Kasajima Ichiro , Ohtsubo Norihiro , Sasaki Katsutomo 
Published: August 2014

Abstract
Purification of plant DNA involves lengthy ultracentrifugation using ethidium bromide. Here, ultracentrifugation method is improved by staining with GelRed. The resulting method is faster, safer and of higher sensitivity. Purified DNA quality was confirmed by treatment with restriction enzymes and isolation of gene promoters. New type of long adaptor with mismatch sequence was also developed for promoter isolation.
Performance Increase in Venous Drainage for Mini-Invasive Heart Surgery: Superiority of Self-Expanding Cannulas
Authors: Belkoniene Mhedi , Abdel-Sayed Saad , Favre Julien , Von Segesser Ludwig-Karl 
Published: August 2014

Objective Originally, the Smartcanula principle (collapsed insertion and expansion in situ) was developed for venous drainage by gravity. However, in minimally invasive surgery, augmentation with either constrained force vortex pumps or vacuum is often used. The current study was set up to assess whether smaller diameters of self-expanding venous cannulas are sufficient in conjunction with venous drainage augmentation resulting in smaller access orifices. Methods To evaluate cannulas intended for cardiopulmonary bypass, an in vitro circuit was set up with silicone tubing between the test cannula encased in a lower reservoir, the centrifugal pump, and after an upper reservoir. Afterload was set arbitrarily at 60 mm Hg using a centrifugal pump. The pressure value was measured using Millar pressure transducers. Flow rate (Q) was measured using an ultrasonic flow meter calibrated with volume tank and timer. Revolutions per minute of the centrifugal pump were calibrated with a stroboscope. Data display and data recording were controlled using a Lab View application. Self-expanding (24F Smartcanula) and control (25F Biomedicus) cannulas were used. Results Sixty measurements were recorded. At pump speed of 1500, 1570, 2000, 2500, and 3000 rpm, the Q values were 3.6, 5.2, 6.6, 9.3, and 11.8 L/min for the 24F self-expanding cannula and 3, 4.3, 5.4, 7.5, and 9.3 L/min for the control cannula. The pressure values were 3.6, −5.4, −15.9, −45.3, and 80.6 mm Hg. Biomedicus 25F showed Q values from 16% to 19% less as compared with 24F Smartcanula. The pressure values were 6, 7, 4, 2, and 2 times more as compared with 24F Smartcanula. Conclusions Our experimental evaluation demonstrated the superior performance of the Smartcanula with its self-expanding design in comparison with the reference commercially available standard cannulas. The Smartcanula with its small diameter is particularly welcome for minimally invasive surgery.
Comparison of Different Resection Tools for Human Calcified Aortic Valves
Authors: Marczynski-Bühlow Martin , Groß Justus , Berndt Rouven , Röcken Christoph , Wedel Thilo , Böttner Martina , Cremer Jochen , Lutter Georg , Petzina Rainer 
Published: August 2014

Objective Symptomatic severe aortic valve stenosis is a disease primarily found in patients of advanced age. The standard therapy is the aortic valve replacement. Transcatheter aortic valve implantation (TAVI) is a treatment for patients ineligible for conventional aortic valve replacement. To minimize the incidence of TAVI-related complications, such as paravalvular leakage, pacemaker necessity, and ostial coronary occlusion, our research group works on the development of resection tools for aortic valves. The aim of this study was to investigate ex vivo different resection tools for human calcified aortic valves concerning cross-section morphology. Methods With the use of 12 human calcified aortic leaflets, the effect of laser scalpel, punching device, and scissors on cross-section morphology was investigated. Scanning electron microscopy and histological analyses were applied to evaluate the cutting surface area. Results The cross-section areas created by a laser scalpel were smooth, regular, and uniform, whereas these areas were rough, irregular, and inhomogeneous when using the scissors or the punching device. Quantitative analysis of the cutting edges demonstrated significant differences between the three resection tools. The best results were obtained for the laser scalpel compared with the punching device ( P < 0.001) and for the laser scalpel compared with the scissors ( P < 0.05), whereas the scissors compared with the punching device showed no significant differences ( P > 0.05). Conclusions Laser cutting of human calcified aortic valves demonstrated the best results concerning homogeneous cross-section morphology compared with the punching device and the scissors and seems to be a promising tool for aortic valve resection during TAVI procedures in the future.
Informal Traders and the Battlegrounds of Revanchism in Cusco, Peru
Authors: Mackie Peter K. , Bromley Rosemary D.F. , Brown Alison M.B. 
Published: August 2014

AbstractInformal trading in the global South, particularly in Latin America, is the subject of revanchist urban policy and yet few studies have examined the longer‐term impacts of such intolerant policies on traders. This article explores the evolution and impacts of revanchist policies directed at informal traders in the Andean city of Cusco. It makes two key contributions. First, it documents a shift from early revanchist policies to a post‐revanchist era where policies have become more tolerant of informal traders. However, contemporary policies fall short of a supportive environment for informal trading, hence the authors recommend changes that will ensure informal traders can access the city's streets and become an accepted part of the urban fabric. Second, given the lack of theoretical attention given to the impacts of revanchism, a battlegrounds framework is developed, consisting of spatial, political, economic and socio‐cultural battlegrounds. This framework provides a comprehensive insight into the complex set of interactions that exist between informal traders and the state. It is hoped that the framework will provide a tool for further research into the highly damaging impacts of revanchism across the globe.
Parmelia sulcata Taylor and Usnea filipendula Stirt induce apoptosis‐like cell death and DNA damage in cancer cells
Authors: Ari F. , Aztopal N. , Oran S. , Bozdemir S. , Celikler S. , Ozturk S. , Ulukaya E. 
Published: August 2014

AbstractObjectivesSuccessful cancer treatments still require more compounds to be isolated from natural sources. Thus, we have investigated anti‐proliferative/apoptotic effects of methanolic extracts of lichen species Parmelia sulcata Taylor and Usnea filipendula Stirt on human lung cancer (A549, PC3), liver cancer (Hep3B) and rat glioma (C6) cells.Materials and methodsAnti‐proliferative effects were monitored by MTT and adenosine triphosphate viability assays, while genotoxic activity was studied using the comet assay. Additionally, cell death mode and apoptosis assays (fluorescence staining, caspase‐cleaved cytokeratin 18, caspase‐3 activity and PARP cleavage) were performed.ResultsExtracts produced anti‐population growth effects in a dose‐dependent manner (1.56–100 μg/ml) by inducing apoptosis‐like cell death. This resulted in the lines having the presence of pyknotic cell nuclei. In addition, significant increase in genetic damage in the cell lines was seen, indicating that DNA damage may have been responsible for apoptotic cell death.ConclusionIn this study, methanolic extracts of Parmelia sulcata and Usnea filipendula induced apoptosis‐like cell death by causing DNA damage, to cancer cells.
Fishing impact and environmental status in European seas: a diagnosis from stock assessments and ecosystem indicators
Authors: Gascuel Didier , Coll Marta , Fox Clive , Guénette Sylvie , Guitton Jérome , Kenny Andrew , Knittweis Leyla , Nielsen J Rasmus , Piet Gerjan , Raid Tiit , Travers‐Trolet Morgane , Shephard Samuel 
Published: August 2014

AbstractStock‐based and ecosystem‐based indicators are used to provide a new diagnosis of the fishing impact and environmental status of European seas. In the seven European marine ecosystems covering the Baltic and the North‐east Atlantic, (i) trends in landings since 1950 were examined; (ii) syntheses of the status and trends in fish stocks were consolidated at the ecosystem level; and (iii) trends in ecosystem indicators based on landings and surveys were analysed. We show that yields began to decrease everywhere (except in the Baltic) from the mid‐1970s, as a result of the over‐exploitation of some major stocks. Fishermen adapted by increasing fishing effort and exploiting a wider part of the ecosystems. This was insufficient to compensate for the decrease in abundance of many stocks, and total landings have halved over the last 30 years. The highest fishing impact took place in the late 1990s, with a clear decrease in stock‐based and ecosystem indicators. In particular, trophic‐based indicators exhibited a continuous decreasing trend in almost all ecosystems. Over the past decade, a decrease in fishing pressure has been observed, the mean fishing mortality rate of assessed stocks being almost halved in all the considered ecosystems, but no clear recovery in the biomass and ecosystem indicators is yet apparent. In addition, the mean recruitment index was shown to decrease by around 50% in all ecosystems (except the Baltic). We conclude that building this kind of diagnosis is a key step on the path to implementing an ecosystem approach to fisheries management.
Body mass and latitude both correlate with primary moult duration in shorebirds
Authors: Dietz Maurine W. , Rogers Ken G. , Gutiérrez Jorge S. , Piersma Theunis 
Published: August 2014

We investigated the effects of body mass and latitude on primary moult duration from published data of migrating shorebirds that moult exclusively on the wintering grounds. Non‐phylogenetic and phylogenetic models demonstrated that body mass and latitude correlate with moult duration in a non‐additive way: the models predict different latitudinal relationships for smaller and larger shorebirds, and in the northern hemisphere, primary moult duration increased allometrically with body mass (exponent = 0.17), whereas in the southern hemisphere, primary moult duration was not correlated with body mass. If birds optimize feather quality and if slower moult yields sturdier feathers, the fast primary moult of northerly wintering shorebirds indicates additional selection pressures at work.
Barn SwallowHirundo rusticaparents work harder when foraging conditions are good
Authors: Schifferli Luc , Grüebler Martin U. , Meijer Harro A. J. , Visser G. Henk , Naef‐Daenzer Beat 
Published: August 2014

In altricial birds, the great effort involved in supplying food to nestlings can create trade‐offs in the allocation of resources between the current brood and parental self‐maintenance. In poor foraging conditions, parents have to adjust their energy expenditure in relation to the increased foraging costs. However, intra‐specific variation in parental energy expenditure has rarely been evaluated in the context of these trade‐offs. Here, we quantified the daily energy expenditure (DEE) of parent Barn SwallowsHirundo rusticaduring the nestling period in relation to foraging conditions while controlling for differences in brood size and nestling age. DEE varied substantially with environmental conditions, increasing by 10 kJ/day per 5 °C in ambient temperature, and by 11 kJ/day per hour in day length. Parent birds did not compensate for a poor aerial insect supply on cool days, but reduced their DEE. Parents only slightly buffered a negative energy balance during chick provisioning with stored body reserves. They did not sacrifice their own energy demands to keep up a high energy flow to the brood when foraging conditions were poor. Instead they worked harder when foraging conditions allowed a surplus intake, fully compensating for their additional efforts, and made maximum use of the rich food supply, allowing the brood to accrue body reserves to compensate for low food intake on cold days. This strategy of energy management may have evolved in the context of the adaptation to the aerial foraging mode and to the ephemeral nature of aerial food resources.
Relationships between dietary intakes of children and their parents: a cross‐sectional, secondary analysis of families participating in the Family Diet Quality Study
Authors: Robinson L. N. , Rollo M. E. , Watson J. , Burrows T. L. , Collins C. E. 
Published: August 2014

AbstractBackgroundBeing overweight and obese in Australian children is common. Current evidence related to parental influence on child dietary intake is conflicting, and is particularly limited in terms of which parent exerts the stronger relationship. The present study aimed to assess mother–father and parent–child dietary relationships and to identify which parent–child relationship is stronger.MethodsA cross‐sectional analysis was performed of dietary intake data from 66 families with one parent and one child aged 8–12 years who were participating in the Family Diet Quality Study, in the Hunter and Forster regions of New South Wales, Australia. Dietary intakes were assessed using adult and child specific, validated semi‐quantitative 120‐item food frequency questionnaires. Diet quality and variety subscores were assessed using the Australian Recommended Food Scores for adults and children/adolescents. Pearson's correlations were used to assess dietary relationships between mother–father, father–child and mother–child dyads.ResultsWeak‐to‐moderate correlations were found between mother–child dyads for components of dietary intake (r = 0.27–0.47). Similarly, for father–child dyads, predominantly weak‐to‐moderate correlations were found (r = 0.01–0.52). Variety of fruit intake was the most strongly correlated in both parent–child dyads, with the weakest relationships found for fibre (g 1000 kJ–1) in father–child and percentage energy from total fats for mother–child dyads. Mother–father dyads demonstrated mostly moderate‐to‐strong correlations (r = 0.13–0.73), with scores for condiments showing the weakest relationship and vegetables the strongest. For all dyads, strong correlations were observed for overall diet quality (r = 0.50–0.59).ConclusionsParent–child dietary intake is significantly related but differs for mother versus fathers. Further research is required to examine whether differing dietary components should be targeted for mothers versus fathers in interventions aiming to improve family dietary patterns.