bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effectiveness of barrier film with a cellulose coating that carries nisin blends for the inhibition of listeria monocytogenes
Authors: Matthews Brian , Mangalasary Sunil , Darby Duncan , Cooksey Kay 
Published: May 2010

AbstractThe objective of this study was to determine the effectiveness of two nisin blend antimicrobial agents (Guardian NR 250, Novagard CBI) incorporated into a cellulose coating that was applied onto a barrier film against Listeria monocytogenes. The minimum inhibitory concentration (MIC) of the agents in solution against L. monocytogenes was found to be 2.74 mg/ml for the two nisin blends. The concentrations tested for both nisin blend treatments were 5.49, 10.9, 16.4 and 21.9 mg/ml. Guardian NR 250 resulted in wider zones of inhibition compared to the Novagard CBI at all levels tested. The MIC for Guardian NR 250 in the film was 5.49 mg/ml. Films containing Novagard CBI did not show any antimicrobial activity. A food challenge study was conducted using the film containing Guardian NR 250 at levels of 5.49 and 21.9 mg/ml. Inoculated fresh beef cubes were individually packaged with pre‐made barrier film pouches that had an interior cellulose coating containing the antimicrobial agent and stored at 4°C for 36 days. Bacterial colonies were enumerated every 6 days on modified Oxford agar. There was no significant difference in the L. monocytogenes population between two levels of Guardian NR 250 throughout the study. There was statistically significant inhibition of L. monocytogenes for both levels of Guardian NR 250 during 18–30 days of storage compared to a control film without the antimicrobial agent. Copyright © 2010 John Wiley & Sons, Ltd.
A comparative study of oxygen transmission rates through polymer films based on fluorescence quenching
Authors: Siró I. , Plackett D. , Sommer‐Larsen P. 
Published: May 2010

AbstractInformation on oxygen permeability through polymer films is essential for some applications, especially in food packaging where the control of oxygen levels can be critical in avoiding food spoilage. A permeability testing device using fluorescence‐based optical oxygen sensing was developed as a potential new instrument for measuring the oxygen permeability of packaging films. The fluorescence‐based permeability tester was validated against two existing commercial oxygen permeability measuring devices, the Mocon Ox‐Tran 2/20 and PBI‐Dansensor OPT‐5000. Oxygen transmission rates (OTR) of polylactide (PLA) and nanoclay‐reinforced PLA films, as well as polyethylene/poly(ethylene terephthalate) (PE/PET) and polypropylene/poly(ethylene terephthalate) (PP/PET) laminated films were determined at 23°C and 50% relative humidity using each of these instruments. No significant differences were observed between mean OTR values obtained by the fluorescence method and the corresponding values obtained using the OPT‐5000 but significantly lower values were measured when using the Mocon Ox‐Tran 2/20. In general, oxygen permeability data for the tested films were within the range of values found in the literature; however, in terms of further development, the fluorescence‐based technique gave OTR with relatively high standard deviation compared to the commercial methods and equipment modifications to address this issue are considered desirable. Copyright © 2010 John Wiley & Sons, Ltd.
Evaluation of product dropping damage based on key component
Authors: Wang Zhi‐Wei , Jiang Jiu‐Hong 
Published: May 2010

AbstractThis paper analyses the packaging system of a product as a two‐degrees‐of‐freedom system, one degree for the key component and the other for the main part of the product. The dropping damage boundary curve was developed based on the key component for linear and non‐linear packaging systems to predict product damage as a result of drop impacts. The dynamic models of two‐degrees‐of‐freedom dropping shock were obtained. For a linear packaging system, the dropping response of the key component was determined by the dimensionless dropping shock velocity, the frequency parameter ratio, the mass ratio and the damping parameters; for a non‐linear system, the system parameter was also used. The frequency parameter ratio of the packaging system and the dimensionless dropping shock velocity were selected as the basic evaluation quantities for the dropping damage of the key component. As an example, the dropping damage boundary curves based on the key component were given for linear and tangent packaging systems. The influence of related parameters such as the mass ratio, the system parameter and the damping parameters on the dropping damage boundary curve was investigated. To verify the theory, experiments were designed and completed. Experiment results for both linear and tangent packaging systems were consistent with the theory suggested in this paper. These results have important value not only for the design of cushioning packaging but also for the improvement of products. Copyright © 2010 John Wiley & Sons, Ltd.
How to distinguish between feruloyl quinic acids and isoferuloyl quinic acids by liquid chromatography/tandem mass spectrometry
Authors: Kuhnert Nikolai , Jaiswal Rakesh , Matei Marius Febi , Sovdat Tina , Deshpande Sagar 
Published: May 2010

AbstractAll four regioisomers of feruloyl quinic acid and isoferuloyl quinic acid were synthesized and a liquid chromatography/tandem mass spectrometry (LC/MS/MS) method developed that resolves all eight regioisomers. All eight regioisomers can be readily distinguished by their MS/MS spectra in the negative ion mode, illustrating the power of tandem mass spectrometry to elucidate the structures of regioisomeric compounds. Compound identification is possible, either by direct comparison of spectral fingerprints or by rational probing of diagnostic fragment ions, thus allowing the identification of these important classes of natural products and potential human metabolites. Copyright © 2010 John Wiley & Sons, Ltd.
A tandem mass spectrometric investigation of the low‐energy collision‐activated fragmentation of neo‐clerodane diterpenes
Authors: Ricci Andreina , Piccolella Simona , Fiorentino Antonio , Pepi Federico , D'Abrosca Brigida , Monaco Pietro 
Published: May 2010

AbstractMass spectrometric fragmentation data of neo‐clerodane diterpenes are almost inexistent but they can prove helpful for the qualitative and quantitative analysis of these compounds as well as for the identification of unknown compounds belonging to this class of plant secondary metabolites. [M–H]– ions of nine neo‐clerodane diterpenes (1–9), recently isolated from Teucrium chamaedrys, were generated by electrospray ionization and were fragmented in the collision cell of a Triple Quadrupole (TQ) and of a Quadrupole Ion Trap (QIT) mass spectrometer. The deprotonated neo‐clerodane glucosides, chamaedryoside A and B (1, 2), readily lost the sugar residue to give, as their main fragmentation channel, the neo‐clerodane ions, I and II, which were structurally characterized by TQ and QIT MS. The collision‐activated dissociation (CAD) mass spectra of I and II and of deprotonated neo‐clerodanes 3–9 allowed us to reach some general conclusions on the fragmentation pathways of this class of compounds. For example, teuflin and its OH derivatives, teucrin A, teuflidin and 6‐β‐hydroxyteucridin, showed a characteristic fragmentation pattern involving the loss of 94 Da and 124 Da from the lactone moiety, whereas a loss of 44 Da was observed for teucrin E, and of 58 Da for teucrin F and G. In addition, several compound‐specific fragmentations were observed and can be proposed for the identification of individual compounds. The systematic approach allowed us to hypothesize the mechanisms of the most important collision‐activated dissociation/isomerization channels. Copyright © 2010 John Wiley & Sons, Ltd.
Effect of ionization suppression by trace impurities in mobile phase water on the accuracy of quantification by high‐performance liquid chromatography/mass spectrometry
Authors: Herath H. M. D. R. , Shaw P. N. , Cabot P. , Hewavitharana A. K. 
Published: May 2010

AbstractThe high‐performance liquid chromatography (HPLC) column is capable of enrichment/pre‐concentration of trace impurities in the mobile phase during the column equilibration, prior to sample injection and elution. These impurities elute during gradient elution and result in significant chromatographic peaks. Three types of purified water were tested for their impurity levels, and hence their performances as mobile phase, in HPLC followed by total ion current (TIC) mode of MS. Two types of HPLC‐grade water produced 3–4 significant peaks in solvent blanks while LC/MS‐grade water produced no peaks (although peaks were produced by LC/MS‐grade water also after a few days of standing). None of the three waters produced peaks in HPLC followed by UV‐Vis detection. These peaks, if co‐eluted with analyte, are capable of suppressing or enhancing the analyte signal in a MS detector. As it is not common practice to run solvent blanks in TIC mode, when quantification is commonly carried out using single ion monitoring (SIM) or single or multiple reaction monitoring (SRM or MRM), the effect of co‐eluting impurities on the analyte signal and hence on the accuracy of the results is often unknown to the analyst. Running solvent blanks in TIC mode, regardless of the MS mode used for quantification, is essential in order to detect this problem and to take subsequent precautions. Copyright © 2010 John Wiley & Sons, Ltd.
A sensitive and specific precursor ion scanning approach in liquid chromatography/electrospray ionization tandem mass spectrometry to detect methylprednisolone acetate and its metabolites in rat urine
Authors: Panusa Alessia , Aldini Giancarlo , Orioli Marica , Vistoli Giulio , Rossoni Giuseppe , Carini Marina 
Published: May 2010

AbstractA new, simple, sensitive and specific liquid chromatography/electrospray ionization tandem mass spectrometric (LC/ESI‐MS/MS) method in precursor ion scanning (PIS) mode has been developed for the rapid detection of methylprednisolone acetate (MPA) and its metabolites in rat urine. A suitable product ion specific for methylprednisolone (MP) and MPA was selected after a fragmentation study on 20 (cortico)steroids at different collision energies (5–40 eV). Urine samples were simply treated with acetonitrile then dried in a SpeedVac system. The method was validated and compared with other PIS methods for detecting corticosteroids in human urine. It was more sensitive, with limit of detection (LOD) and lower limit of quantitation (LLOQ), respectively, of 5 and 10 ng mL−1. The method was applied for the analysis of rat urine collected before and after (24, 48, 72 h) intra‐articular (IA) injection of a marketed formulation of MPA (Depo‐Medrol®). MS/MS acquisitions were taken at different collision energies for the precursor ions of interest, detected in PIS mode, to verify the MP‐related structure. Six different metabolites were detected in rat urine, and their chemical structures were assigned with a computational study. Copyright © 2010 John Wiley & Sons, Ltd.
The Sanaga discharge at the Edea Catchment outlet (Cameroon): An example of hydrologic responses of a tropical rain‐fed river system to changes in precipitation and groundwater inputs and to flow regulation
Authors: Dzana Jean‐Guy , Ngoupayou Jules Remy Ndam , Tchawa Paul 
Published: May 2010

AbstractThe Sanaga River is one of Sub‐Saharan Africa's largest and greatly regulated rivers. Available flow data for this hydrosystem largely cover the pre‐ and post‐regulation periods. From comparisons between unregulated (hypothetical) and observed scenarios, it has been possible to separate and to quantify hydro‐climatic (groundwater + rainfall) change effects from anthropogenic impacts (especially dam‐related alterations). To appreciate shifts in the river regime, discontinuity detection tests and the IHA model were applied to discharge data series reflecting average and extreme flow conditions, respectively. Results obtained principally from the Hubert segmentation method reveal that a major discontinuity occurred in 1970–1971 separating a surplus phase between 1945–1946 and 1969–1970, and a deficient and much contrasted one, from 1971/1972. This implies that the Sanaga catchment is dominantly affected by hydro‐climatic changes. However, wide land cover/land use changes experienced here since 1988 have resulted in an increase in surface runoff. Additional quickflows linked to these changes may have partly compensated for the substantial decline in the dry season rainfall and groundwater inputs observed from this date. Although at the monthly scale, dam‐related impacts on average flows increase with stage of regulation, the seasonal variability of the river regime remains generally unaffected. A comparison of the IHA statistics, calculated from unregulated and observed streamflow data, show that hydrologic shifts occurring in maximum and minimum discharges are mostly significant from 1971/1972 and are mainly due to the action of dams. Minimum flows appear, however, widely impacted, thus reflecting the prime objective assigned to the existing reservoirs, constructed to supplement flows for hydroelectricity production during the dry season. Copyright © 2010 John Wiley & Sons, Ltd.
A learning progression for scientific argumentation: Understanding student work and designing supportive instructional contexts
Authors: Berland Leema K. , McNeill Katherine L. 
Published: May 2010

AbstractArgumentation is a central goal of science education because it engages students in a complex scientific practice in which they construct and justify knowledge claims. Although there is a growing body of research around argumentation, there has been little focus on developing a learning progression for this practice. We describe a learning progression to understand both students' work in scientific argumentation and the ways in which the instructional environment can support students in that practice. This learning progression describes three dimensions: (1) instructional context, (2) argumentative product, and (3) argumentative process. In this paper, we compare four examples from elementary, middle, and high school science classrooms to explore the ways in which students' arguments vary in complexity across grade level and instructional contexts. Our comparisons suggest that simplifying the instructional context may facilitate students in engaging in other aspects of argumentation in more complex ways. The instructional context may also be used as a tool to support students in argumentation in new content areas and to increase the complexity of their written arguments, which may be weaker than their oral arguments. Furthermore, classroom norms play an important role in supporting students of all ages, including elementary students, in argumentation. © 2010 Wiley Periodicals, Inc. Sci Ed 94:765–793, 2010
Architecture and performance evaluation of a hybrid intrusion detection system for IP telephony
Authors: Barry Bazara I. A. , Chan H. A. 
Published: May 2010

AbstractConvergence in networks and applications enables carrying voice, video, and other data on the same IP‐based infrastructure, and provides various services related to these kinds of data in a unified way. Such a scheme benefits businesses substantially considering the lesser cost of building and managing a single network infrastructure instead of two separate ones. However, the same scheme poses serious threats to security solutions in general, and intrusion detection systems (IDSs) in particular. Inherited flaws and vulnerabilities in TCP/IP protocols at lower layers make voice susceptible to risks it has never been subjected to before in public switched telephone networks (PSTNs). Signaling and data delivery protocols at application layer have their weaknesses too which make breaching of confidentiality and integrity relatively easy. In this paper, we present the design and implementation of a hybrid, host‐based intrusion detection system that is suitable for converged environments. Our design is unique in terms of providing an efficient combination of specification‐based and signature‐based detection techniques. Specification‐based and signature‐based detection modules provide solid awareness of the semantics as well as the syntax of the protocols involved. Our solution goes beyond addressing the issues of application layer protocols to address transport and network layer protocols as well in a unified way. The feasibility of our design is proven through the excellent detection accuracy and reasonable performance evaluation figures we get from our experiment. Copyright © 2010 John Wiley & Sons, Ltd.
Korrosionsschäden an nichtrostenden Stählen unter atmosphärischen Einsatzbedingungen
Authors: Burkert Andreas , Lehmann Jens , Burkert Annette , Mietz Jürgen 
Published: May 2010

AbstractNeben konstruktiven Anforderungen werden an nichtrostende Stähle im Bauwesen häufig hohe optische Ansprüche gestellt. Unerwartete Beeinträchtigungen des optischen Erscheinungsbildes nichtrostender Stähle unter wenig korrosiven Bedingungen sind in der Zwischenzeit ein weit verbreitetes Problemfeld und Gegenstand zahlreicher Streitfälle. Vielfach wird die Vermutung geäußert, dass eine veränderte Legierungszusammensetzung, veränderte Umweltbedingungen oder auch die unsachgemäße Verarbeitung die Ursache für diese Erscheinungen sind. Durch eine systematische Untersuchung zahlreicher Schadensfälle an Stabmaterial in den vergangenen zwei Jahren im Rahmen eines Forschungsvorhabens konnte gezeigt werden, dass die Ursachen in bekannten Werkstofffehlern zu finden sind. Hierzu gehören chemische Inhomogenitäten, wie zum Beispiel Ausscheidungen und örtliche Aufkohlung, sowie geometrische Fehler, wie zum Beispiel Hinterschnitte, Walzfehler und Schalenbildung. Die Fehler konnten damit eindeutig als Herstellungsfehler der jeweiligen Halbzeuge identifiziert werden.Corrosion damage of stainless steels under atmospheric exposure conditions. In addition to constructional requirements in civil engineering stainless steels often have to fulfil high visual demands. Unexpected impairments of the visual appearance of stainless steels under corrosive conditions are a widespread problem today. Frequently it is supposed that this is caused by changes in the alloy composition, worse environmental conditions or improper handling. Within a research project the systematic investigation of several cases of damaged stainless steel bars has shown that the reasons are based on well‐known material defects like chemical inhomogeneities (e.g. precipitations or local carburization) or geometrical defects (e.g. undercuts, rolling defects or shell formation). Thus, the failures could be clearly identified as production failures of the respective semi‐finished products.
Hematopoietic Stem Cell Defects in Mice with Deficiency of Fancd2 or Usp1
Authors: Parmar Kalindi , Kim Jungmin , Sykes Stephen M. , Shimamura Akiko , Stuckert Patricia , Zhu Kaya , Hamilton Abigail , Deloach Mary Kathryn , Kutok Jeffery L. , Akashi Koichi , Gilliland D. Gary , D'andrea Alan 
Published: May 2010

Abstract
Fanconi anemia (FA) is a human genetic disease characterized by a DNA repair defect and progressive bone marrow failure. Central events in the FA pathway are the monoubiquitination of the Fancd2 protein and the removal of ubiquitin by the deubiquitinating enzyme, Usp1. Here, we have investigated the role of Fancd2 and Usp1 in the maintenance and function of murine hematopoietic stem cells (HSCs). Bone marrow from Fancd2−/− mice and Usp1−/− mice exhibited marked hematopoietic defects. A decreased frequency of the HSC populations including Lin-Sca-1+Kit+ cells and cells enriched for dormant HSCs expressing signaling lymphocyte activation molecule (SLAM) markers, was observed in the bone marrow of Fancd2-deficient mice. In addition, bone marrow from Fancd2−/− mice contained significantly reduced frequencies of late-developing cobblestone area-forming cell activity in vitro compared to the bone marrow from wild-type mice. Furthermore, Fancd2-deficient and Usp1-deficient bone marrow had defective long-term in vivo repopulating ability. Collectively, our data reveal novel functions of Fancd2 and Usp1 in maintaining the bone marrow HSC compartment and suggest that FA pathway disruption may account for bone marrow failure in FA patients.
Comparison of likelihood ratios of first‐trimester nuchal translucency measurements: multiples of median, delta or mixture
Authors: Sahota D. S. , Leung T. Y. , Chen M. , Chan L. W. , Fung T. Y. , Lau T. K. 
Published: May 2010

AbstractObjectiveTo compare the likelihood ratios (LR) determined for a measured nuchal translucency (NT) using the multiples of the median (MoM), delta‐NT and mixture model approaches.MethodsThis was a retrospective study of singleton pregnancies with known outcome screened at the 12th week of pregnancy between January 2006 and May 2008. NT, crown–rump length (CRL) and LR for trisomy 21 using the delta‐NT approach (LRNT‐delta) were extracted from The Fetal Medicine Foundation trisomy 21 risk‐calculation software database. NT measurements were converted into their equivalent MoM by dividing by the expected CRL‐specific median NT. LR for trisomy 21 based on the MoM (LRNT‐MoM) of each case was then calculated as the ratio of the Gaussian probability density functions using published trisomy 21 risk‐screening parameters. The LR using the mixture model (LRNT‐mixture) was calculated as the ratio of individual composite probability densities reported for trisomy 21 and unaffected pregnancies. The intraclass correlation coefficient (ICC) was used to assess the agreement between the three different approaches while the paired t‐test was used to perform pairwise comparisons.ResultsOf the 5907 pregnancies with known outcome, 14 had trisomy 21. The ICC between the three approaches to determining an LR was 0.947 (95% CI, 0.943–0.951; P < 0.0001). Pairwise comparison indicated that differences between LR were statistically significant (P < 0.0001). Likelihood ratios determined via the delta‐NT model were in general greater than those produced by both the mixture model (z = 5.58, P < 0.0001) and the MoM approaches (z = 32.8, P < 0.0001). For a 5% false‐positive rate the detection rate of trisomy 21 (DR) was 78.6% (95% CI, 57.1–99.9%) The screen positive thresholds to achieve this DR were 1 : 200 for the delta‐NT approach, 1 : 220 for the mixture approach and 1 : 290 for the MoM approach.ConclusionNo single method of determining NT‐associated LR outperformed the others in its ability to detect a trisomy 21‐affected pregnancy. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Torsional torque suppression of generator based on H∞ control theory in isolated power system
Authors: Yona Atsushi , Omine Eitaro , Goya Tomonori , Senjyu Tomonobu 
Published: May 2010

AbstractRenewable energy power plants, such as wind turbine generator and photovoltaic system, have been introduced in isolated power system recently. The output power fluctuations of wind turbine generator and load deviations result in frequency deviation and terminal voltage fluctuation. Furthermore, these power fluctuations also affect the turbine shafting of diesel generators and gas‐turbine generators, which are the main components of power generation systems in isolated islands. For stable operation of gas‐turbine generator, the torsional torque suppression as well as power system stabilization should be considered. In this paper, the control strategy that achieves torsional torque suppression and power system stabilization is presented based on H∞ control theory. The effectiveness of the proposed control system is validated by numerical simulation results. Copyright © 2010 John Wiley & Sons, Ltd.