bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pterodon pubescens Oil: Characterisation, Certification of Origin and Quality Control via Mass Spectrometry Fingerprinting Analysis
Authors: Cabral E. C. , Sevart L. , Spindola H. M. , Coelho M. B. , Sousa I. M. O. , Queiroz N. C. A. , Foglio M. A. , Eberlin M. N. , Riveros J. M. 
Published: October 2012

ABSTRACTIntroductionThe oil obtained from Pterodon pubescens (Leguminosae) seeds are known to display anti‐cancer, anti‐dermatogenic and anti‐nociceptive activitiy. Phytochemical studies have demonstrated that its main constituents are diterpenoids with voucapan skeletons. Considering the potential biological activities of the oil, rapid and efficient methods for assessing its quality would facilitate certification and quality control.ObjectiveTo develop a direct mass spectrometric fingerprinting method for the P. pubescens seed oil that would focus on the major diterpenoids constituents, enabling quality control, origin certification and recognition of marker species in commercially available products.MethodTwo techniques were used: (i) direct infusion electrospray ionisation (ESI) mass spectrometry after solvent extraction and dilution and (ii) ambient desorption/ionisation via easy ambient sonic‐spray ionisation, EASI(+)–MS, performed directly on the seed surface or at a paper surface imprinted with the oil.ResultsFrom a combination of ESI–MS, HRESI–MS and ESI–MS/MS data, 12 diterpenes were characterised, and typical profiles were obtained for the oil extract or the crude oil via both ESI–MS and EASI–MS. These techniques require no or very simple sample preparation protocols and the whole analytical processes with spectra acquisition take just a few minutes.ConclusionBoth techniques, but particularly EASI–MS, provide simple, fast and efficient MS fingerprinting methodologies to characterise the P. pubescens oil with typical (di)terpene profiles being applicable to quality control and certification of authenticity and origin. Copyright © 2012 John Wiley & Sons, Ltd.
Interaction and electronic structures of oxygen divacancy in HfO2
Authors: Zhang Wei , Hou Z. F. 
Published: October 2012

AbstractWe have studied the interaction between two neutral oxygen vacancies and the electronic structures of oxygen divacancy in the monoclinic phase of HfO2 by performing the first‐principles calculations. It is found that the vacancy–vacancy interaction depends not only on the distance but also on the coordination of the removed oxygen atoms. The oxygen divacancy is formed energetically by the removal of two fourfold coordinated oxygen atoms (O4) with a distance of about 2.73 Å. The interaction between two O4 vacancies is attractive, indicating that the O4 vacancies tend to form stable cluster in HfO2. The oxygen divacancy induces two in‐gap defect levels, which correspond to a bonding state and an anti‐bonding one. These results would provide insightful information to understand the formation of conductive filaments in HfO2‐based resistive random access memory devices.
Evaluating agarwood products for 2‐(2‐phenylethyl)chromones using direct analysis in real time time‐of‐flight mass spectrometry
Authors: Lancaster Cady , Espinoza Edgard 
Published: October 2012

RATIONALEAgarwood is the resinous material harvested from threatened Aquilaria species. We investigated how many protonated 2‐(2‐phenylethyl)chromone ions were sufficient to make an accurate identification of agarwood. Analysis of 125 reference samples was carried out by direct analysis in real time time‐of‐flight mass spectrometry (DART‐TOFMS). The identification criteria developed were applied to commercial samples.METHODSWe developed a technique that uses DART‐TOFMS to detect 2‐(2‐phenylethyl)chromones. Additionally, we developed a set of criteria to infer the presence of Aquilaria in commercial samples of wood chips, sawdust, incense and liquids. Additionally, we examined other fragrant woods to determine if they contained a chemical profile that could be falsely identified as agarwood.RESULTSAnalysis of reference and commercial samples (n = 151) established that DART‐TOFMS provides reproducible mass spectra that are useful for inferring the genus of suspected agarwood samples. We identified 17 ions which were useful for authenticating agarwood. Comparison of the number of chromone ions detected by direct analyses of dry wood chips versus eluent analysis of methanol‐extracted wood showed that results were similar. Lastly, analysis of 25 scented woods of other species did not give false positive results.CONCLUSIONSReliable criteria for inferring agarwood include the presence of diagnostic ions, m/z 319.118 or 349.129, in addition to ten or more ions characteristic of 2‐(2‐phenylethyl)chromones. Wood anatomists challenged with difficult morphological identifications can use this tool to assist in their analyses. Published 2012. This article is a US Government work and is in the public domain in the USA.
High‐precision measurements of 17O/16O and 18O/16O ratios in CO2
Authors: Barkan Eugeni , Luz Boaz 
Published: October 2012

RATIONALEMeasurements of δ17O and δ18O values of tropospheric CO2 are of great importance. However, to be useful, such measurements must be an order of magnitude more precise than in current published literature. With this purpose we developed a new method for high‐precision mass spectrometric measurements of 17O/16O and 18O/16O ratios in CO2, which is presented in this study.METHODSThe method is based on isotopic exchange equilibration between H2O and CO2 in sealed glass ampoules followed by water fluorination to produce O2. Dual inlet isotope ratio mass spectrometric (IRMS) measurements of the δ17O and δ18O values of this O2 allow δ17O values of CO2 to be obtained with very high precision (0.01 to 0.03 ‰). This method requires about 70 µmol of CO2.RESULTSMeasurements of standard CO2 gas and atmospheric CO2 yield reproducibility of 0.01 to 0.03 ‰ for both δ17O and δ18O values, and 5 per meg for 17Oexcess. Fractionation factors 17α and 18α were determined in the H2O–CO2 equilibrium at 25 °C as 1.021254 ± 0.00004 and 1.041036 ± 0.00008, respectively, and the ratio ln17α/ln18α as 0.5229 ± 0.0001.CONCLUSIONSThe results demonstrate that the new method is the most accurate analytical procedure ever presented for measurements of 17Oexcess of CO2 gas. It is suitable for measurements of CO2 extracted from relatively small samples of air (~5 L), and is thus useful for monitoring the 17Oexcess of CO2 on a broad global scale. Copyright © 2012 John Wiley & Sons, Ltd.
Intersample ripple‐free multirate optimal controller design
Authors: Sideris Athanasios 
Published: October 2012

SUMMARYA systematic approach for the design of multirate controllers resulting in closed loops free of intersample ripple is proposed. The approach is particularly suited for design frameworks such as optimal control for which previous proposed conditions to eliminate intersample ripple cannot be readily incorporated. It is based on transforming the control inputs in the lifted transfer matrix of the design plant in a manner that stabilizing controllers for the transformed plant are in one‐to‐one correspondence with stabilizing ripple‐free controllers for the original plant. Thus, no solutions are lost in the process of this transformation and a general stability result is obtained that can be also used in other multirate controller design methodologies to achieve ripple‐free response. The results do not require that the plant should be open‐loop stable and in particular can contain integrating instabilities. Copyright © 2012 John Wiley & Sons, Ltd.
POTENTIAL LARGE WOODY DEBRIS RECRUITMENT DUE TO LANDSLIDES, BANK EROSION AND FLOODS IN MOUNTAIN BASINS: A QUANTITATIVE ESTIMATION APPROACH
Authors: Ruiz‐Villanueva V. , Díez‐Herrero A. , Ballesteros J. A. , Bodoque J. M. 
Published: October 2012

ABSTRACTIn‐depth knowledge of the fluvial corridor and surrounding slopes and forest vegetation is needed for a better understanding of wood recruitment or inputs to rivers. The information available in Central Spain on hydrogeomorphic processes and forest distribution enabled the evaluation of potential wood recruitment from three sources: landslides, bank erosion and fluvial transport during floods on a regional scale. The method presented here is based on a geographical information system (GIS) and on multi‐criteria and multi‐objective assessment using fuzzy logic principles. First, the areas potentially affected by landslides, bank erosion and floods were delineated, and a vegetation analysis was carried out to obtain the vegetation resistance and forest density. Several scenarios were proposed based on the process frequency and severity. Using this method, the volume of potentially available wood can be estimated for each scenario.Fourteen river basins in populated areas were selected for further analyses and field survey. Observations of in‐stream storage of woody debris and tree disturbances were used to interpret the woody debris dynamics throughout the watershed and validate the obtained results.This method offers a suitable approach to define a watershed's capacity to recruit wood material to streams by delineating the source areas and estimating the order of magnitude of the wood volume in each case. The results may be useful to characterize the dynamics of woody debris from the perspective of the potential hazard of its transport during floods, and they can also be used for forest and river management and restoration. Copyright © 2012 John Wiley & Sons, Ltd.
Resolving Sub‐Molecular Binding and Electrical Switching Mechanisms of Single Proteins at Electroactive Conducting Polymers
Authors: Gelmi A. , Higgins M. J. , Wallace G. G. 
Published: October 2012

AbstractPolymer‐based electrodes for interfacing biological tissues are becoming increasingly sophisticated. Their many functions place them at the cross‐roads of electromaterials, biomaterials, and drug‐delivery systems. For conducting polymers, the mechanism of conductivity requires doping with anionic molecules such as extracellular matrix molecules, a process that distinguishes them as biomaterials and provides a means to control interactions at the cellular–electrode interface. However, due to their complex structure, directly observing the selective binding of target molecules or proteins has so far eluded researchers. This situation is compounded by the polymer's ability to adopt different electronic states that alter the polymer–dopant interactions. Here, the ability to resolve sub‐molecular binding specificity between sulfate and carboxyl groups of dopants and heparin binding domains of human plasma fibronectin is demonstrated. The interaction exploits a form of biological ‘charge complementarity’ to enable specificity. When an electrical signal is applied to the polymer, the specific interaction is switched to a non‐specific, high‐affinity binding state that can be reversibly controlled using electrochemical processes. Both the specific and non‐specific interactions are integral for controlling protein conformation and dynamics. These details, which represent the first direct measurement of biomolecular recognition between a single protein and any type of organic conductor, give new molecular insight into controlling cellular interactions on these polymer surfaces.
Smart‐grid policies: an international review
Authors: Brown Marilyn A. , Zhou Shan 
Published: October 2012

The electric power systems of many industrialized nations are challenged by the need to accommodate distributed renewable generation, increasing demands of a digital society, growing threats to infrastructure security, and concerns over global climate disruption. The ‘smart grid’—with a two‐way flow of electricity and information between utilities and consumers—can help address these challenges, but various financial, regulatory, and technical obstacles hinder its rapid deployment. An overview of experiences with smart‐grid policies in pioneering countries shows that many governments have designed interventions to overcome these barriers and to facilitate grid modernization. Smart‐grid policies include a new generation of regulations and finance models such as regulatory targets, requirements for data security and privacy, renewable energy credits, and various interconnection tariffs and utility subsidies.This article is categorized under:

Energy Infrastructure > Economics and Policy
Energy Systems Economics > Economics and Policy
Energy and Climate > Economics and Policy
Variations on Slavnov’s scalar product
Authors: Foda O. , Wheeler M. 
Published: October 2012

AbstractWe consider the rational six-vertex model on anL×Llattice with domain wall boundary conditions and restrictNparallel-line rapidities,N≤L/2, to satisfy length-LXXX$ \mathrm{spin}-\frac{1}{2} $chain Bethe equations. We show that the partition function is an (L− 2N)- parameter extension of Slavnov’s scalar product of a Bethe eigenstate and a generic state, withNmagnons each, on a length-LXXX$ \mathrm{spin}-\frac{1}{2} $chain. Decoupling the extra parameters, we obtain a third determinant expression for the scalar product, where the first is due to Slavnov [1], and the second is due to Kostov and Matsuo [2]. We show that the new determinant is Casoratian, and consequently that tree-level$ \mathcal{N}=4 $SYM structure constants that are known to be determinants, remain determinants at 1-loop level.
Discovery of invariants through automated theory formation
Authors: Llano Maria Teresa , Ireland Andrew , Pease Alison 
Published: October 2012

Abstract
Refinement is a powerful mechanism for mastering the complexities that arise when formally modelling systems. Refinement also brings with it additional proof obligations—requiring a developer to discover properties relating to their design decisions. With the goal of reducing this burden, we have investigated how a general purpose automated theory formation tool, HR, can be used to automate the discovery of such properties within the context of the Event-B formal modelling framework. This gave rise to an integrated approach to automated invariant discovery. In addition to formal modelling and automated theory formation, our approach relies upon the simulation of system models as a key input to the invariant discovery process. Moreover we have developed a set of heuristics which, when coupled with automated proof-failure analysis, have enabled us to effectively tailor HR to the needs of Event-B developments. Drawing in part upon case study material from the literature, we have achieved some promising experimental results. While our focus has been on Event-B, we believe that our approach could be applied more widely to formal modelling frameworks which support simulation.
A critical discussion of the physics of wood–water interactions
Authors: Engelund Emil Tang , Thygesen Lisbeth Garbrecht , Svensson Staffan , Hill Callum A. S. 
Published: October 2012

AbstractThis paper reviews recent findings on wood–water interaction and puts them into context of established knowledge in the field. Several new findings challenge prevalent theories and are critically discussed in an attempt to advance current knowledge and highlight gaps. The focus of this review is put on water in the broadest concept of wood products, that is, the living tree is not considered. Moreover, the review covers the basic wood–water relation, states and transitions. Secondary effects such as the ability of water to alter physical properties of wood are only discussed in cases where there is an influence on state and/or transition.
Thoracic Duct Injury Following Esophagectomy in Carcinoma of the Esophagus: Ligation by the Abdominal Approach
Authors: Mishra Pramod Kumar , Saluja Sundeep Singh , Ramaswamy Dinesh , Bains Satinderpal Singh , Haque Parvez David 
Published: October 2012

AbstractBackgroundThoracic duct injury (TDI) is a potentially lethal complication of esophagectomy. There is no consensus regarding when and how to intervene in these injuries. Both thoracic and abdominal approaches have been used.MethodsEsophagectomies performed for cancer of the esophagus (n = 104) from October 2003 to July 2011 were analyzed for TDI. Diagnosis, histological type, stage, and location of tumor, neoadjuvant therapy, trans‐thoracic or trans‐hiatal procedure performed, nature and amount of drain output, and levels of triglyceride in the effluent were analyzed. Management of these injuries and morbidity and mortality associated with the approach taken were reviewed.ResultsWe observed chylothorax in 9 patients. All nine patients had undergone trans‐hiatal esophagectomy. All patients eventually required surgical intervention. Mass ligation of the thoracic duct was performed via the thoracic route in three patients and via the trans‐abdominal approach in six others. Thoracic duct ligation was successful in all patients. One patient required a second laparotomy and repeat ligation of the duct. There were two postoperative deaths; both these patients had ligation by the thoracic route.ConclusionsTrans‐abdominal ligation of the thoracic duct in patients with chylothorax after esophagectomy is technically easy and safe. It may be preferred over the trans‐thoracic approach, especially after an initial trans‐hiatal esophagectomy.
Glutathione S‐Transferase M1 Gene Polymorphism Is Associated with Susceptibility to Impaired Long‐term Allograft Outcomes in Renal Transplant Recipients
Authors: Chang Horng‐Rong , Tsai Jen‐Pi , Yang Shun‐Fa , Lin Chih‐Kuang , Lian Jong‐Da 
Published: October 2012

AbstractBackgroundDespite improved post‐transplantation care, progress in long‐term kidney allograft survival of diabetic renal transplant recipients (pre‐DM RTR) is worse than that of non‐diabetic recipients (non‐DM). We hypothesized that there are other potential risk factors, that predispose RTR to adverse renal allograft outcomes.MethodsA total of 323 transplant recipients who underwent renal transplantation between March 2000 and January 2008 were recruited. The composite end‐point consisted of serum creatinine (SCr) doubling, graft failure, and death. Baseline clinical data were recorded, and polymerase chain reaction‐restriction fragment length polymorphism measurements of interleukin (IL)‐4, IL‐10, IL‐23, glutathione S‐transferase (GST)A1, GSTM1, and GSTP1 polymorphisms were determined. The risk factors for developing the primary outcome were analyzed among these clinical and genetic factors.ResultsWithin a mean follow‐up of 71.1 ± 24 months, there were 43 (13.3 %) patients with the primary outcome. Stepwise multivariate Cox regression analysis was used to determine the risk factors for the primary outcome of RTR. Renal transplant recipients who possessed the GSTM1 null genotype had a 2.2‐fold risk (95 % CI: 1.10–4.40; P = 0.026) of developing the primary outcome. Additionally, RTR that had DM before transplantation (aHR: 3.31; 95 % CI: 1.77–6.20; P = 0.0002) or changes in SCr 6 to 12 months after transplantation (aHR: 2.83; 95 % CI: 1.29–6.19; P = 0.0095) had an increased risk of developing the primary outcome.ConclusionsIn addition to the adverse role played by DM, the GSTM1 null genotype also has an unfavorable influence on the long‐term allograft outcome of RTR.
Analysis of gamete membrane dynamics during double fertilization of Arabidopsis
Authors: Igawa Tomoko , Yanagawa Yuki , Miyagishima Shin-ya , Mori Toshiyuki 
Published: October 2012

Abstract
Angiosperms have a unique sexual reproduction system called “double fertilization.” One sperm cell fertilizes the egg and another sperm cell fertilizes the central cell. To date, plant gamete membrane dynamics during fertilization has been poorly understood. To analyze this unrevealed gamete subcellular behavior, live cell imaging analyses of Arabidopsis double fertilization were performed. We produced female gamete membrane marker lines in which fluorescent proteins conjugated with PIP2a finely visualized egg cell and central cell surfaces. Using those lines together with a sperm cell membrane marker line expressing GCS1-GFP, the double fertilization process was observed. As a result, after gamete fusion, putative sperm plasma membrane GFP signals were occasionally detected on the egg cell surface adjacent to the central cell. In addition, time-lapse imaging revealed that GCS1-GFP signals entered both the egg cell and the central cell in parallel with the sperm cell movement toward the female gametes during double fertilization. These findings suggested that the gamete fusion process based on membrane dynamics was composed of (1) plasma membrane fusion on male and female gamete surfaces, (2) entry of sperm internal membrane components into the female gametes, and (3) plasmogamy.
Evolution and the Cumulative Nature of Science
Authors: Zeigler David 
Published: October 2012

AbstractOne of the characteristics of science is its cumulative nature. As more discoveries are made and more is learned, we progressively come to a more and more complete understanding of the physical universe. Evolutionary biology serves as an excellent example of this progressive trend in knowledge, since we now understand significantly more about the mechanisms and details of the evolutionary process than we did in decades past. It is important to comprehend these progressive changes and communicate them effectively to students of evolutionary biology.
Teaching Tree Thinking to College Students: It’s Not as Easy as You Think
Authors: Phillips Brenda C. , Novick Laura R. , Catley Kefyn M. , Funk Daniel J. 
Published: October 2012

AbstractThe ability to understand and reason with tree-of-life diagrams (i.e., cladograms), referred to as tree thinking, is an essential skill for biology students. Yet, recent findings indicate that cladograms are cognitively opaque to many college students, leading them to misinterpret the information depicted. The current studies address the impact of prior biological background and instruction in phylogenetics on students’ competence at two foundational tree-thinking skills. In Study 1, college students with stronger (N = 52) and weaker (N = 60) backgrounds in biology were asked to (a) identify all the nested clades in two cladograms and (b) evaluate evolutionary relatedness among taxa positioned at different hierarchical levels (two questions) and included in a polytomy (two questions). Stronger-background students were more successful than weaker-background students. In Study 2, a subset of the stronger-background students (N = 41) who were enrolled in an evolution class subsequently received two days of instruction on phylogenetics. As expected, these students’ tree-thinking skills generally improved with instruction. However, although these students did very well at marking the nested clades, fundamental misinterpretations of relative evolutionary relatedness remained. The latter was especially, although not exclusively, the case for taxa included in a polytomy. These results highlight the importance of teaching cladistics, as well as the need to tailor such instruction to the difficulties students have learning key macroevolutionary concepts.