bluuebunny/crossref_metadata_2025 huggingface dataset:
Ocean acidification state in western Antarctic surface waters: controls and interannual variability
Authors: Mattsdotter Björk M. , Fransson A. , Torstensson A. , Chierici M.
Published: January 2014

Abstract. During four austral summers (December to January) from 2006 to 2010, we investigated the surface-water carbonate system and its controls in the western Antarctic Ocean. Measurements of total alkalinity (AT), pH and total inorganic carbon (CT) were investigated in combination with high-frequency measurements on sea-surface temperature (SST), salinity and Chl a. In all parameters we found large interannual variability due to differences in sea-ice concentration, physical processes and primary production. The main result from our observations suggests that primary production was the major control on the calcium carbonate saturation state (Ω) in austral summer for all years. This was mainly reflected in the covariance of pH and Chl a. In the sea-ice-covered parts of the study area, pH and Ω were generally low, coinciding with low Chl a concentrations. The lowest pH in situ and lowest aragonite saturation (ΩAr ~ 1.0) were observed in December 2007 in the coastal Amundsen and Ross seas near marine outflowing glaciers. These low Ω and high pH values were likely influenced by freshwater dilution. Comparing 2007 and 2010, the largest ΩAr difference was found in the eastern Ross Sea, where ΩAr was about 1.2 units lower in 2007 than in 2010. This was mainly explained by differences in Chl a (i.e primary production). In 2010 the surface water along the Ross Sea shelf was the warmest and most saline, indicating upwelling of nutrient and CO2-rich sub-surface water, likely promoting primary production leading to high Ω and pH. Results from multivariate analysis agree with our observations showing that changes in Chl a had the largest influence on the ΩAr variability. The future changes of ΩAr were estimated using reported rates of the oceanic uptake of anthropogenic CO2, combined with our data on total alkalinity, SST and salinity (summer situation). Our study suggests that the Amundsen Sea will become undersaturated with regard to aragonite about 40 yr sooner than predicted by models.
Uptake of algal carbon and the synthesis of an "essential" fatty acid by Uvigerina ex. gr. semiornata (Foraminifera) within the Pakistan margin oxygen minimum zone: evidence from fatty acid biomarker and 13C tracer experiments
Authors: Larkin K. E. , Gooday A. J. , Woulds C. , Jeffreys R. , Schwartz M. , Cowie G. , Whitcraft C. , Levin L. , Dick J. R. , Pond D. W.
Published: January 2014

Abstract. Foraminifera are an important component of benthic communities in oxygen depleted settings, where they potentially play a~significant role in the processing of organic matter. We tracked the uptake of a 13C-labeled algal food source into individual fatty acids in the benthic foraminiferal species, Uvigerina ex. gr. semiornata, from the Arabian Sea oxygen minimum zone (OMZ). The tracer experiments were conducted on the Pakistan Margin during the late/post monsoon period (August–October 2003). A monoculture of the diatom Thalassiosira weisflogii was 13C-labeled and used to simulate a pulse of phytoplankton in two complementary experiments. A lander system was used for in situ incubations at 140 m and for 2.5 days duration, whilst a laboratory incubation used an oxystat system to maintain ambient dissolved oxygen concentrations. These shipboard experiments were terminated after 5 days. Uptake of diatoms was rapid, with high incorporation of diatom fatty acids into foraminifera after ~2 days in both experiments. Ingestion of the diatom food source was indicated by the increase over time in the quantity of diatom biomarker fatty acids in the foraminifera and by the high percentage of 13C in many of the fatty acids present at the endpoint of both in~situ and laboratory-based experiments. These results indicate that U. ex. gr. semiornata rapidly ingested the diatom food source and that this foraminifera will play an important role in the short-term cycling of organic matter within this OMZ environment. The experiments also suggested that U. ex. gr. semiornata consumed non-labeled bacterial food items, particularly bacteria, and synthesised the polyunsaturated fatty acid 20:4(n-6) de novo. 20:4(n-6) is often abundant in benthic fauna yet its origins and function have remained unclear. This study demonstrates that U. ex. gr. semiornata is capable of de novo synthesis of this "essential fatty acid" and is potentially a major source of this dietary nutrient in benthic food webs.
Evaluating climate field reconstruction techniques using improved emulations of real-world conditions
Authors: Wang J. , Emile-Geay J. , Guillot D. , Smerdon J. E. , Rajaratnam B.
Published: January 2014

Abstract. Pseudoproxy experiments (PPEs) have become an important framework for evaluating paleoclimate reconstruction methods. Most existing PPE studies assume constant proxy availability through time and uniform proxy quality across the pseudoproxy network. Real multiproxy networks are, however, marked by pronounced disparities in proxy quality, and a steep decline in proxy availability back in time, either of which may have large effects on reconstruction skill. A suite of PPEs constructed from a millennium-length general circulation model (GCM) simulation is thus designed to mimic these various real-world characteristics. The new pseudoproxy network is used to evaluate four climate field reconstruction (CFR) techniques: truncated total least squares embedded within the regularized EM (expectation-maximization) algorithm (RegEM-TTLS), the Mann et al. (2009) implementation of RegEM-TTLS (M09), canonical correlation analysis (CCA), and Gaussian graphical models embedded within RegEM (GraphEM). Each method's risk properties are also assessed via a 100-member noise ensemble. Contrary to expectation, it is found that reconstruction skill does not vary monotonically with proxy availability, but also is a function of the type and amplitude of climate variability (forced events vs. internal variability). The use of realistic spatiotemporal pseudoproxy characteristics also exposes large inter-method differences. Despite the comparable fidelity in reconstructing the global mean temperature, spatial skill varies considerably between CFR techniques. Both GraphEM and CCA efficiently exploit teleconnections, and produce consistent reconstructions across the ensemble. RegEM-TTLS and M09 appear advantageous for reconstructions on highly noisy data, but are subject to larger stochastic variations across different realizations of pseudoproxy noise. Results collectively highlight the importance of designing realistic pseudoproxy networks and implementing multiple noise realizations of PPEs. The results also underscore the difficulty in finding the proper bias-variance tradeoff for jointly optimizing the spatial skill of CFRs and the fidelity of the global mean reconstructions.
Arctic Holocene proxy climate database – new approaches to assessing geochronological accuracy and encoding climate variables
Authors: Sundqvist H. S. , Kaufman D. S. , McKay N. P. , Balascio N. L. , Briner J. P. , Cwynar L. C. , Sejrup H. P. , Seppä H. , Subetto D. A. , Andrews J. T. , Axford Y. , Bakke J. , Birks H. J. B. , Brooks S. J. , de Vernal A. , Jennings A. E. , Ljungqvist F. C. , Rühland K. M. , Saenger C. , Smol J. P. , Viau A. E.
Published: January 2014

Abstract. We present a systematic compilation of previously published Holocene proxy climate records from the Arctic. We identified 167 sites from north of 58° N latitude where proxy time-series extend back at least to 6 cal ka, are resolved at sub-millennial scale (at least one value every 400 ± 200 yr) and have age models constrained by at least one age every 3000 yr. In addition to conventional metadata for each proxy record (location, proxy type, reference), we include two novel parameters that add functionality to the database. First, "climate interpretation" is a series of fields that logically describe the specific climate variable(s) represented by the proxy record. It encodes the proxy-climate relation reported by authors of the original studies into a structured format to facilitate inter-comparison with climate model output. Second, "geochronology accuracy score" (chron score) is a numerical rating that reflects the overall accuracy of 14C-based age models from lake and marine sediments. Chron scores were calculated using the original author-reported 14C ages, which are included in this database. The database contains 315 records (some sites include multiple records) from six regions covering the circumpolar Arctic; Fennoscandia is the most densely sampled region (30% of the records), whereas only five records from the Russian Arctic met the criteria for inclusion. The database contains proxy records from lake sediment (60%), marine sediment (32%), glacier ice (5%), and other sources. Most (60%) reflect temperature (mainly summer warmth) and are primarily based on pollen, chironomid, or diatom assemblages. Many (15%) reflect some aspect of hydroclimate as inferred from changes in stable isotopes, pollen and diatom assemblages, humification index in peat, and changes in equilibrium-line altitude of glaciers. This comprehensive database can be used in future studies to investigate the spatial-temporal pattern of Arctic Holocene climate changes and their causes. The Arctic Holocene dataset is available from NOAA Paleoclimatology.
Explaining the seasonal cycle of the globally averaged CO2 with a carbon cycle model
Authors: Alexandrov G. A.
Published: January 2014

Abstract. The discrepancy between simulated and observed globally averaged monthly atmospheric concentrations of carbon dioxide could be attributed either to deficiencies in the observation network or to inadequacies in the global carbon cycle models. This paper shows that model results could be brought closer to observations by improving model components that describe the seasonal changes in the storage of quickly decaying fractions of litter.
There Is No Alibi in Designing: Responsibility and Dialogue in the Design Process
Authors: Kenniff Thomas-Bernard , Sweeting Ben
Published: January 2014

This paper explores a potential relation between architecture and ethics intrinsic to design processes when understood in terms of dialogue or conversation. We draw on separate but related research interests: one focused on the design process, especially the significance of drawing, and the other on the ethics of designing for the public realm, with reference to Bakhtinian dialogism. Our investigation concentrates on two aspects of the design process both of which can be thought of in terms of conversation – first, the relation between architect and Other, and second, the act of drawing. Through this, we support the idea that in design the ethical and the aesthetic cannot be meaningfully separated from one another. Instead, their relation must be understood as a dialogue in and of itself, as well as part of the dialogue between all participants in the design process.
Video Technologies: Neologism or Library Trend
Authors: Harnish Thomas D.
Published: January 2014

Video Technologies: Neologism or Library Trend
LITA Award, 1980: Maurice J. Freedman
Authors: Malinconico S. Michael
Published: January 2014

LITA Award, 1980: Maurice J. Freedman
Highlights of LITA Board Meetings
Authors: Aveny Brian
Published: January 2014

Highlights of LITA Board Meetings, 1981 Annual Conference, San Francisco
Social Contexts of New Media Literacy: Mapping Libraries
Authors: Thorne Wallington Elizabeth
Published: January 2014

The development and diffusion of new media and digital technologies has profoundly affected the literacy experiences of today’s youth.  Young people today develop literacy through a variety of new media and digital technologies (Ito et al, 2009).  The dissemination of these resources has also allowed for youth to have literacy-rich experiences in an array of different settings.  This paper will explore how mapping and geographic information systems (GIS) can help illuminate the cultural and social factors related to how, and where, students access and use new media literacies and digital technology.  Libraries play an important role in encouraging new media literacy development; yet access to libraries must be understood through social and cultural contexts.
Levels of Machine Readable Records
Authors: Avram Henriette , De Gennaro Richard , Pulsifer Josephine S. , Rather John C. , Rosenthal Joseph A. , Veaner Allen B.
Published: January 2014

This study of the feasibility of determining levels or subsets of the established MARC II format concludes that only two levels are necessary and desirable for national purposes: 1) the full MA.RC II format for distribution purposes; and 2) a less complex subset to be used by libraries reporting holdings to the National Union Catalog.
Le tourisme sénégalais à la recherche d’une nouvelle identité
Authors: Diombéra Mamadou
Published: January 2014

Le secteur du tourisme au Sénégal s’est imposé comme le véritable moteur de l’économie, au second rang après la pêche. Développé aussitôt après les indépendances, le tourisme international et essentiellement balnéaire, appréhendé comme un facteur de développement, n’a cessé de croître. Les arrivées massives de touristes, notamment de type tout inclus, ont quasiment quadruplé de 1960 à 2000. Les transactions touristiques ont atteint, durant la même période, près de 10 % de la valeur globale du commerce extérieur du pays. Malheureusement, ces dernières années, la destination est fortement concurrencée et son image, stigmatisée par la mauvaise réputation de la station balnéaire de Saly Portudal. Face à une telle situation qui devient de plus en plus exécrable, les autorités sénégalaises tentent éperdument, depuis bientôt une décennie, de trouver des éléments de réponse à la lancinante problématique du tourisme de masse par la diversification de l’offre à travers la mise en place de nouvelles formes alternatives de tourisme.
Le rôle des informations touristiques dans la médiatisation du territoire de visite
Authors: Simon Gwendal
Published: January 2014

Les représentations catégorisent aisément le tourisme de groupe comme une expérience « institutionnalisée » référant à un tourisme de masse où les pratiques seraient à la fois encadrées et largement dirigées vers les objets et des services identifiés comme touristiques. Ainsi, la voie serait ouverte pour une expérience peu authentique. La compacité et l’univocité de tels voyages sont aujourd’hui très affaiblies par la différenciation croissante des offres proposées et la prise en compte de la capacité réflexive des touristes au cours de leur voyage. Celle-ci se révèle inégale selon l’acculturation au territoire de visite. C’est l’hypothèse principale de cet article qui, à travers l’exemple de la diffusion des informations opérées par un voyagiste à Paris et de leur réception par les touristes étrangers, souligne combien la médiatisation d’un territoire dans le cadre d’un voyagiste résulte d’une coconstruction entre les professionnels du voyage et des touristes eux-mêmes.
Le concept de cluster est-il soluble dans le tourisme ?
Authors: Clergeau Cécile , Violier Philippe
Published: January 2014

Dans les approches scientifiques, le concept de cluster (grappe) met en évidence, d’une part, le rôle des proximités organisationnelles, construites à partir des proximités spatiales dans la dynamique de compétitivité des destinations touristiques. D’autre part, des clusters tourisme se développent partout dans le monde. Or, le concept de cluster, tel que proposé par Porter (1998), émane de l’économie industrielle.

L’enjeu de cet article consiste donc à montrer que le simple transfert d’un outil scientifique élaboré dans le contexte industriel au management des destinations touristiques pose problème. Il doit être enrichi pour comprendre les dynamiques de développement touristique local et acquérir plus d’efficacité opérationnelle. Trois axes de réflexion théorique, mais inspirés par des études de cas rencontrées dans différents travaux de recherche, sont proposés pour interroger les analyses des clusters tourisme. Il convient en effet de prendre en compte trois dimensions spécifiques qui seront abordées à partir du processus de coproduction inhérent à l’activité touristique, des dynamiques de proximités singulières dans ce champ du tourisme et des caractéristiques de l’encastrement des activités touristiques dans le territoire. Enfin, les auteurs proposent un modèle de cluster plus adapté aux destinations touristiques.
L’attractivité d’un événement sportif, entre accomplissement personnel et enchantement touristique
Authors: Ben Mahmoud Imed , Massiera Bernard
Published: January 2014

En prenant comme objet d’investigation le marathon des Alpes-Maritimes, nous avons choisi d’explorer sociologiquement l’attractivité de cet événement. Une enquête de nature quantitative met en exergue certaines caractéristiques de la population pratiquante. Les résultats révèlent que cette course de grand fond rassemble majoritairement des pratiquants occasionnels et quarantenaires, dont la part féminine est élevée, et essentiellement attirés par un dépassement de soi, associé à l’enchantement du site azuréen. Leurs activités relèvent davantage du registre de la consommation touristique que de celui de la pratique compétitive. Participer au marathon s’apparente ainsi à une consommation ludique et touristique qui diverge des actuelles modalités organisationnelles issues de la tradition compétitive. Si, aujourd’hui, l’événement sportif place la course en position centrale, dans le futur, participer à un tel événement s’envisagera sous la forme d’un séjour de tourisme dont l’un des produits d’appel serait de concourir à un marathon.
Decolonizing Aboriginal Education in the 21st Century
Authors: Munroe Elizabeth Ann , Borden Lisa Lunney , Murray Orr Anne , Toney Denise , Meader Jane
Published: January 2014

Concerned by the need to decolonize education for Aboriginal students, the authors explore philosophies of Indigenous ways of knowing and those of the 21st century learning movement. In their efforts to propose a way forward with Aboriginal education, the authors inquire into harmonies between Aboriginal knowledges and tenets of 21st century education. Three stories from the authors’ research serve as examples of decolonizing approaches that value the congruence between 21st century education and Indigenous knowledges. These stories highlight the need for two-eyed seeing, co-constructing curriculum for language and culture revitalization, and drawing from community contexts to create curriculum.
L’aide personnalisée à l’école primaire en france : quels formation continue et axes de pilotage développer pour favoriser la réussite de tous les élèves ?
Authors: Notebaert Céline , Notebaert Jean-François
Published: January 2014

Afin de lutter contre l’échec scolaire, l’organisation du temps scolaire à l’école primaire en France a été modifiée et des heures d’aide ont été dédiées aux enfants en difficulté. Tous les professeurs des écoles assurent deux heures d’aide personnalisée par semaine, en dehors des 24 heures de classe, à des petits groupes d’élèves. Ce dispositif, induisant une prise en charge individualisée de la difficulté en dehors de la classe, est susceptible de modifier les pratiques des enseignants. Sur la base d’une étude qualitative, les nouvelles pratiques et relations découlant de l’aide personnalisée à l’école primaire ont été étudiées et des préconisations en termes de formation des enseignants et de pilotage des écoles ont été proposées.
Étude du sentiment d’auto-efficacité des enseignants du secondaire au Niger à l’égard
de l’ordinateur
Authors: Coulibaly Modibo , Karsenti Thierry
Published: January 2014

L’article traite du sentiment d’auto-efficacité des enseignants du lycée
relativement à l’ordinateur. Cette étude apparaît capitale, car les TIC peuvent améliorer la
qualité de l’éducation. Cependant, la non-qualification des enseignants retarde
l’intégration pédagogique de celles-ci. Un questionnaire soumis à 69 enseignants a permis de
comparer leur sentiment d’auto-efficacité envers l’utilisation du traitement de texte et
l’usage de diverses autres applications technologiques. Une recherche quantitative à partir
de l’adaptation du Computer Self-Efficacy Scale révèle une différence de perceptions de
niveaux d’habiletés techniques entre enseignants formés aux TIC et non formés.
Something Resembling Hope: Notes on strategies for teaching Canadian social justice literature
Authors: Yoder Amarou
Published: January 2014

Members of a large, cross-Canada research project on using Canadian social justice literature in the classroom share strategies that teachers are using to teach some of these texts. Strategies range from multi-media projects to song adaptations. Texts and strategies suitable for different grade-levels are represented, and cover a range of subjects, from residential schools to Canada’s history of segregation.
Purification of Radiolabeled RNA Products Using Denaturing Gel Electrophoresis
Authors: Adachi Hironori , Yu Yi‐Tao
Published: January 2014

This unit discusses a basic method for purification of radiolabeled RNAs using denaturing polyacrylamide gel electrophoresis. The method consists of a number of experimental procedures, including total RNA preparation from yeast cells, isolation of a specific RNA from total yeast RNA, RNA 3′‐terminal labeling using nucleotide (5′ [32P]pCp) addition (via ligation), denaturing (8 M urea) polyacrylamide gel electrophoresis, and RNA extraction from the gel slice. Key points for achieving good electrophoretic separation of RNA are also discussed. Curr. Protoc. Mol. Biol. 105:4.20.1‐4.20.13. © 2014 by John Wiley & Sons, Inc.
An analysis of Alfvén radius based on sunspot number from 1749 to today
Authors: Goelzer Molly L. , Schwadron Nathan A. , Smith Charles W.
Published: January 2014

The Solar Probe Plus mission now under construction will provide the first in situ measurements from inside the orbit of Mercury. The most critical part of that mission will be measurements from inside the Alfvén radius where the Alfvén speed exceeds the wind speed and the physics of the solar wind changes fundamentally due, in part, to the multidirectionality of wave propagation. In this region waves from both sunward and antisunward of the observation point can effect the local dynamics including the turbulent evolution, heating, and acceleration of the plasma. While the location of this point can change with solar wind conditions, we ask the question of whether there is a systematic dependence on the solar cycle that moves the average Alfvén radius to different locations depending upon solar activity. We show that the average Alfvén radius is correlated with the sunspot number and moves systematically from ∼ 15 at solar minimum to 30 RS at solar maximum. The analysis shown here does not predict movement of the Alfvén radius during the recent protracted solar minimum. We project the average Alfvén radius backward and forward in time using the monthly sunspot record to attempt a better understanding of the historical record and predict the behavior of this point during the coming solar cycle.
Transmission line model for the near‐instantaneous transmission of the ionospheric electric field and currents to the equator
Authors: Kikuchi Takashi
Published: January 2014

The simultaneous onset of the preliminary impulse (PI) of the geomagnetic sudden commencement at high latitude and dayside dip equator is explained by means of the TM0 mode waves propagating at the speed of light in the Earth‐ionosphere waveguide (EIW) [Kikuchi et al., 1978]. A couple of issues remain to be addressed in the EIW model: (1) How is the TM0 mode wave excited by the field‐aligned currents (FACs) in the polar region? (2) How are the quasi‐steady ionospheric currents achieved by the TM0 mode waves? (3) How simultaneous or delayed are the onset and peak of the equatorial PI with respect to the high‐latitude PI? To address these issues, we examine the TEM (TM0) mode wave propagation in the finite‐length transmission lines replacing the pair of FACs (magnetosphere‐ionosphere (MI) transmission line) and the Earth‐ionosphere waveguide (ionosphere‐ground (IG) transmission line). The issue (1) is addressed by showing that a fraction of the TEM mode wave is transmitted from the MI to IG transmission lines through the polar ionosphere. To address the issues (2) and (3), we examine the properties of the finite‐length IG transmission line with finite ionospheric conductivity. It is shown that the ionospheric currents start to grow instantaneously and continue to grow gradually with time constants of 1–10 s depending on the ionospheric conductivity. The MIG transmission line enables us to explain the instantaneous onset and delayed peak time of the equatorial PI and quick electric field response of the low‐latitude ionosphere and inner magnetosphere.
Bildungsroman Series: Architectural Daring for the 21st Century
Authors: Slavinsky Dan
Published: January 2014

Emerging artist and architect Dan Slavinsky created this Bildungsroman series of drawings as a coming‐of‐age novel in graphic form; with each pair of drawings covering a particular aspect of his own personal journey to become an architect. Here he describes his predicament, as a young architect, to find a means to challenge and innovate at a time when everything seems to have been tried, and artistic flair is all too often compromised.
Complex Hydrides for Electrochemical Energy Storage
Authors: Unemoto Atsushi , Matsuo Motoaki , Orimo Shin‐ichi
Published: January 2014

Complex hydrides have energy storage‐related functions such as i) solid‐state hydrogen storage, ii) electrochemical Li storage, and iii) fast Li‐ and Na‐ionic conductions. Here, recent progress on the development of fast Li‐ionic conductors based on the complex hydrides is reported. The validity of using them as electrolytes in all‐solid‐state lithium rechargeable batteries is also examined. Not only coated oxides but also bare sulfides are found to be applicable as positive electrode active materials. Results related to fast Na‐ionic conductivity in the complex hydrides are presented. In the last section, the future prospects for battery assemblies with high‐energy densities, and Mg ion batteries with the liquid and the solid‐state electrolytes are discussed.
The role of virtual photons in nanoscale photonics
Authors: Andrews David L. , Bradshaw David S.
Published: January 2014

The fundamental theory of processes and properties associated with nanoscale photonics should properly account for the quantum nature of both the matter and the radiation field. A familiar example is the Casimir force, whose significant role in nanoelectromechanical systems is widely recognised; the correct representation invokes the creation of short‐lived virtual photons from the vacuum. In fact, there is an extensive range of nanophotonic interactions in which virtual photon exchange plays a vital role, mediating the coupling between particles. This review surveys recent theory and applications, also exhibiting novel insights into key electrodynamic mechanisms. Examples are numerous and include: laser‐induced inter‐particle forces known as optical binding; non‐parametric frequency‐conversion processes especially in rare‐earth doped materials; light‐harvesting polymer materials that involve electronic energy transfer between their constituent chromophores. An assessment of these and the latest prospective applications concludes with a view on future directions of research.
In vitro screening of Fe2+‐chelating effect by a Fenton's reaction–luminol chemiluminescence system
Authors: Wada Mitsuhiro , Komatsu Hiroaki , Ikeda Rie , Aburjai Talal A. , Alkhalil Suleiman M. , Kuroda Naotaka , Nakashima Kenichiro
Published: January 2014

In vitro screening of a Fe2+‐chelating effect using a Fenton's reaction–luminol chemiluminescence (CL) system is described. The luminescence between the reactive oxygen species generated by the Fenton's reaction and luminol was decreased on capturing Fe2+ using a chelator. The proposed method can prevent the consumption of expensive seed compounds (drug discovery candidates) owing to the high sensitivity of CL detection. Therefore, the assay could be performed using small volumes of sample solution (150 μL) at micromolar concentrations. After optimization of the screening conditions, the efficacies of conventional chelators such as ethylenediaminetetraacetic acid (EDTA), diethylentriaminepentaacetic acid (DETAPAC), deferoxamine, deferiprone and 1,10‐phenanthroline were examined. EC50 values for these compounds (except 1,10‐phenanthroline) were in the range 3.20 ± 0.87 to 9.57 ± 0.64 μM (n = 3). Rapid measurement of the Fe2+‐chelating effect with an assay run time of a few minutes could be achieved using the proposed method. In addition, the specificity of the method was discussed. Copyright © 2014 John Wiley & Sons, Ltd.
Feasibility and efficacy of the 2.5 L and 3.8 L impella percutaneous left ventricular support device during high‐risk, percutaneous coronary intervention in patients with severe aortic stenosis
Authors: Spiro Jon , Venugopal Vinod , Raja Yogesh , Ludman Peter F. , Townend Jonathan N. , Doshi Sagar N.
Published: January 2014

Objective

Assessment of the feasibility and outcomes of the 2.5 L and 3.8 L Impella cardiac pump in patients with severe aortic stenosis (AS) and left ventricular impairment undergoing percutaneous revascularization (PCI) with or without balloon aortic valvuloplasty (BAV).

Methods

We reviewed the clinical and procedural findings from a consecutive series of unselected patients with severe AS who underwent PCI during Impella support. In addition, we describe novel “balloon‐assist” techniques that allowed implantation of Impella into the left ventricle (LV) when initial unassisted attempts failed.

Results

Five patients with severe AS were identified (four males, age 78.2 years, aortic valve area (AVA) 0.6 cm2, left ventricular ejection fraction (LVEF) 24 ± 5%, mean Society of Thoracic Surgeons (STS) mortality 11% (range 3–17%)). The Impella catheter traversed the aortic valve (AV) unassisted in only one patient, with four cases requiring balloon‐assist techniques. All patients underwent planned revascularisation; mean procedure time 177 min (range 135–252 min), mean number of stents 3.4 (range 1–8), with three patients requiring rotational atherectomy. All procedures were well tolerated, with absence of arrhythmia, hypotension, pulmonary edema, stroke, or myocardial infarction. One patient died 48 hr post‐PCI of multi‐organ failure. The four remaining patients were well at 30 days.

Conclusion

Implantation of the 2.5 and 3.8 L Impella appears feasible in patients with severe AS and left ventricle (LV) impairment. A balloon‐assist technique may be used to facilitate device implantation when initial unassisted attempts fail. Improved hemodynamic stability may enhance the tolerability of lengthy and complex procedures. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.
Single center TAVR experience with a focus on the prevention and management of catastrophic complications
Authors: Kapadia Samir R. , Svensson Lars G. , Roselli Eric , Schoenhagen Paul , Popovic Zoran , Alfirevic Andrej , Barzilai Benico , Krishnaswamy Amar , Stewart William , Mehta Anand , lal Poddar Kanhaiya , Parashar Akhil , Modi Dhruv , Ozkan Alper , Khot Umesh , Lytle Bruce W. , Murat Tuzcu E.
Published: January 2014

Background

Transcatheter aortic valve replacement (TAVR) is an important treatment option for patients with severe symptomatic aortic stenosis (AS) who are inoperable or at high risk for complications with surgical aortic valve replacement. We report here our single‐center data on consecutive patients undergoing transfemoral (TF) TAVR since the inception of our program, with a special focus on minimizing and managing complications.

Methods

The patient population consists of all consecutive patients who underwent an attempted TF‐TAVR at our institution, beginning with the first proctored case in May 2006, through December 2012. Clinical, procedural, and echocardiographic data were collected by chart review and echo database query. All events are reported according to Valve Academic Research Consortium‐2.

Results

During the study period, 255 patients with AS had attempted TF‐TAVR. The procedure was successful in 244 (95.7%) patients. Serious complications including aortic annular rupture (n = 2), coronary occlusion (n = 2), iliac artery rupture (n = 1), and ventricular embolization (n = 1) were successfully managed. Death and stroke rate at 30 days was 0.4% and 1.6%, respectively. One‐year follow‐up was complete in 171 (76%) patients. One‐year mortality was 17.5% with a 3.5% stroke rate. Descending aortic rupture, while advancing the valve, was the only fatal procedural event. There were 24.4% patients with ≥2+ aortic regurgitation.

Conclusions

TAVR can be accomplished with excellent safety in a tertiary center with a well‐developed infrastructure for the management of serious complications. The data presented here provide support for TAVR as an important treatment option, and results from randomized trials of patients with lower surgical risk are eagerly awaited. © 2014 Wiley Periodicals, Inc.
Presence of sigma shaped right coronary artery is an indicator of poor prognosis in patients with inferior myocardial infarction treated with primary percutaneous coronary intervention
Authors: Güngör Barış , Alper Ahmet Taha , Özcan Kazım Serhan , Ekmekçi Ahmet , Karadeniz Fatma Özpamuk , Mutluer Ferit Onur , Kaya Adnan , Karataş Baran , Osmonov Damirbek , Bolca Osman
Published: January 2014

Background

The effectiveness of primary percutaneous coronary intervention (PCI) in ST segment elevation myocardial infarction (STEMI) is well established. The clinical variables associated with poor prognosis in patients with STEMI have been extensively investigated. Right coronary artery (RCA) has two anatomical variations detected on coronary angiography namely C‐shaped and sigma shaped RCA. The clinical importance of the shape of RCA in patients with STEMI has not been investigated before.

Purpose

To investigate the prognostic value of RCA shape in patients with inferior STEMI treated with primary PCI.

Methods

Angiographic data of patients with inferior STEMI who were treated with primary PCI were retrospectively recruited. The differentiation of sigma and C‐shaped RCAs was shown using single‐frame angiograms, obtained during end‐diastole of cardiac cycle in the left anterior oblique projection at 25° to 35° with no cranio‐caudal angulation. Cardiovascular events at 30‐days and on follow up were obtained through review of hospital records and telephone contact with the patient or the patient's relatives. Patients with C‐shaped RCAs served as the control group.

Results

A total number of 824 patients with inferior STEMI who were treated with primary PCI for RCA were included. Sigma shaped RCA was observed in 15.1% of the subjects. In the sigma shaped RCA group, the door‐to‐balloon times were longer (32.5 ± 5.1 vs. 27.8 ± 4.6 min; P = 0.01) and TIMI 3 flow restoration rates were lower (76.8% vs. 94.1%; p=0.01) compared to the controls. Mean SYNTAX scores were significantly higher in patients with sigma shaped RCA. Four patients (3.2%) in the sigma shaped RCA group and 23 patients (3.3%) in the control group died by day 30. The incidence of stent thrombosis, recurrent MI, and target lesion revascularization, were similar between the groups. During the follow‐up (mean 37.6 ± 13.4 months) 15 patients (12.3%) from the sigma shaped RCA group and 28 (4.1%) patients from the control group died (P = 0.01). The incidence of recurrent MI (27.2% vs. 13.7%; P = 0.01) and major adverse cardiovascular events (29.7% vs. 16.3%; P = 0.01) were significantly higher in the sigma shaped RCA group. In multivariate analysis, age, Killip class of >1, the presence of sigma shaped RCA, post PCI TIMI flow <3 and decreased left ventricular ejection fraction were the independent predictors of long term mortality.

Conclusion

Presence of sigma shaped RCA is associated with more severe form of coronary artery disease and worse clinical outcome in patients with inferior STEMI. © 2014 Wiley Periodicals, Inc.
Blood loss and transfusion rates associated with transcatheter aortic valve replacement: Recommendations for patients who refuse blood transfusion
Authors: Binder Ronald K. , Barbanti Marco , Ye Jian , Toggweiler Stefan , Tan John , Freeman Melanie , Cheung Anson , Wood David A. , Webb John G.
Published: January 2014

Background

Transcatheter aortic valve replacement (TAVR) is less invasive than surgical aortic valve replacement and may be preferred for patients who refuse blood transfusions.

Objectives

Our study sought to define transfusion rates in TAVR, identify predictors and develop recommendations for patients who refuse transfusions.

Methods

A large cohort of consecutive patients undergoing TAVR was prospectively studied. Blood loss and transfusion rates were observed in patients undergoing transfemoral (TF‐TAVR) and transapical TAVR (TA‐TAVR). Predictors for transfusion were investigated in a multivariate model.

Results

Of 373 consecutive patients, 270 underwent TF‐TAVR and 103 TA‐TAVR. Transfusion rates were significantly lower in TF‐TAVR than TA‐TAVR (11.1 vs 41.7%; P < 0.001). In patients who did not receive transfusions, blood loss was significantly lower in TF‐TAVR than TA‐TAVR (23.6 ± 12.2 g/l vs 28.9 ± 13.7 g/l; P = 0.004), but did not differ in transfused patients (36.9 ± 12.9 g/l vs 33.4 ± 21.2 g/l; P = 0.428). Predictors for transfusions were low baseline hemoglobin, female sex, low body weight and decreased renal function. In seven Jehovah's Witness patients, who refused transfusions, no vascular complications occurred and clinical outcome was excellent.

Conclusion

In patients, who refuse transfusions, TAVR may be performed with good clinical outcomes provided a high baseline hemoglobin level, careful management of the access site and strict measurements to reduce blood loss. TF‐TAVR is associated with less blood loss and a lower rate of transfusions than TA‐TAVR, and may be the preferred option for patients, who refuse transfusions. © 2014 Wiley Periodicals, Inc.
Enhanced image contrast with delocalized near‐field excitation
Authors: Sánchez E. , Dunham A. , Nowak D. , Straton J. , Doughty J.
Published: January 2014

For Tip Enhanced Near‐field Optical Microscopy (TENOM) utilizing detection of fluorescence or Raman emission, signal to noise amplification is highly desirable for higher resolution imaging. This goal may be achieved by amplifying the signal produced by the probe at the sample through a highly resonant geometry and/or by filtering out the unwanted signal of the excitation source through the addition of an aperture in the collection optical pathway. Making highly resonant tip geometries via nanofabrication can be a difficult process, while the aperture method is a much easier method. With this technique, even tips with undesirably low resonance can be utilized for imaging. We demonstrate the concept through the use of a low field enhancement probe by showing the spatial separation of the excitation and field enhancement locations. We also are able to predict this effect using finite difference time domain modeling of the potential geometries for a desired wavelength.
Hospitalized heart failure patients with preserved vs. reduced ejection fraction in Dubai, United Arab Emirates: a prospective study
Authors: Saheb Sharif‐Askari Narjes , Syed Sulaiman Syed Azhar , Saheb Sharif‐Askari Fatemeh , Al Sayed Hussain Ali , Tabatabai Sadeq , Abdullatif Al‐Mulla Arif
Published: January 2014

Aims

To compare the baseline characteristics, pharmacological treatment, and in‐hospital outcomes across hospitalized heart failure (HF) patients with preserved LVEF (HF‐PEF) and those with reduced LVEF (HF‐REF).

Method and results

This was a prospective analysis of consecutive patients admitted with decompensated HF at two government hospitals in the United Arab Emirates, from 1 December 2011 to 30 November 2012. Multivariate factors of HF‐PEF vs. HF‐REF included elevated systolic blood pressure [odds ratio (OR) 1.02; 95% confidence interval (CI) 1.01–1.03], heart rate (OR 0.98; 95% CI 0.97–0.99), age (OR 1.02; 95% CI 1.01–1.04), female sex (OR 2.38; 95% CI 1.41–4.03), angina or myocardial infarction (OR 0.42; 95% CI 0.25–0.71), AF (OR 1.82; 95% CI 1.05–3.15), COPD or asthma (OR 2.80; 95% CI 1.47–5.35), Charlson Comorbidity Index score (OR 0.75; 95% CI 0.64–0.88), and anaemia (OR 2.97; 95% CI 1.64–5.38). In‐hospital outcomes were similar between the two groups. However, patients with HF‐PEF were less likely to be prescribed HF medication, and used more anticoagulants and fewer antiplatelet medications.

Conclusion

These results suggest that patients with HF‐PEF are older, more often female, and have higher prevalence of respiratory diseases and AF. Compared with developed countries, hospitalized HF patients in the Middle East are 10 years younger and have a higher prevalence of diabetes mellitus, and the majority have HF‐REF.
Comparative study of the performance of an anaerobic rotating biological contactor and its potential to enrich hydrogenotrophic methanogens
Authors: Abubakkar Shabana , Kundu Kankana , Sreekrishnan Trichur Ramaswamy
Published: January 2014

BACKGROUND

Process upset due to volatile fatty acid accumulation is one of the major drawbacks of anaerobic treatment of wastewater. The performance of an anaerobic rotating biological contactor (AnRBC) was studied under normal operating conditions as well as shock loadings of propionic acid, for its ability to enhance the conversion of hydrogen to methane. These results were compared with those of a reactor lacking the enhanced gas‐liquid hydrogen transfer mechanism, a conventional anaerobic digester.

RESULT

The AnRBC exhibited lower concentrations of hydrogen in the headspace (300–600 ppm) under both normal and shock loading conditions, and also showed more hydrogenotrophic methanogens on the denaturing gradient gel electrophoresis (DGGE) profile of 16S rRNA gene amplicons, both in terms of intensity and band numbers (4 in the AnRBC and 2 in the anaerobic digester).

CONCLUSION

This study showed that the AnRBC is able to maintain lower hydrogen partial pressure at both normal operating and shock loading conditions due to the abundance of hydrogenotrophic methanogens and good gas–liquid hydrogen transfer efficiency. This finding should encourage the commercial exploitation of AnRBC for the treatment of wastewaters, especially that containing easily acidifiable organic compounds, which causes instability in operation through souring. © 2014 Society of Chemical Industry
Thermoresponsive behavior and rheology of SiO2–hyaluronic acid/poly(N‐isopropylacrylamide) (NaHA/PNIPAm) core–shell structured microparticles
Authors: Li Xiangye , Chen Ruting , Xu Shouhong , Liu Honglai , Hu Ying
Published: January 2014

BACKGROUND

Injectable polymer gels for tissue engineering offer specific advantages over preformed scaffolds. They can transform from a sol to a block gel as a response to an external stimulus. One effective strategy for improving the mechanical strength of a gel is to introduce an inorganic material.

RESULTS

Microparticles composed of a hard SiO2 core covered with a thermoresponsive hybrid gel (sodium hyaluronate/poly(N‐isopropylacrylamide); NaHA/PNIPAm) were synthesized. The microparticles were characterized by dynamic light‐scattering and transmission electron microscopy; rheological measurements were also performed. The microparticles were perfectly spherical and had a core–shell structure. They can perform a sol–gel transformation, that is, they shrank and assembled to form a macroscopic hydrogel through physical cross‐linking at the gelation temperature (Tgel), which was determined by rheological measurements. The Tgel was adjusted by changing the concentration of microparticles or Ca2+ ions.

CONCLUSION

The introduction of NaHA and SiO2 improved the mechanical properties of the macroscopic gels. The rigidity and stability of the macroscopic gel were controlled by the molecular weight of NaHA and the amount of PNIPAm. Such injectable hydrogels might have potential as scaffold biomaterials, and are expected to be the ‘ink’ for three‐dimensional bioprinters. © 2014 Society of Chemical Industry
Accounting for soil biotic effects on soil health and crop productivity in the design of crop rotations
Authors: Dias Teresa , Dukes Angela , Antunes Pedro M
Published: January 2014

There is an urgent need for novel agronomic improvements capable of boosting crop yields while alleviating environmental impacts. One such approach is the use of optimized crop rotations. However, a set of measurements that can serve as guiding principles for the design of crop rotations is lacking. Crop rotations take advantage of niche complementarity, enabling the optimization of nutrient use and the reduction of pests and specialist pathogen loads. However, despite the recognized importance of plant–soil microbial interactions and feedbacks for crop yield and soil health, this is ignored in the selection and management of crops for rotation systems. We review the literature and propose criteria for the design of crop rotations focusing on the roles of soil biota and feedback on crop productivity and soil health. We consider that identifying specific key organisms or consortia capable of influencing plant productivity is more important as a predictor of soil health and crop productivity than assessing the overall soil microbial diversity per se. As such, we propose that setting up soil feedback studies and applying genetic sequencing tools towards the development of soil biotic community databases has a strong potential to enable the establishment of improved soil health indicators for optimized crop rotations. © 2014 Society of Chemical Industry
Non‐destructive inspection and risk assessment for the inner wall scale exfoliation of high temperature boiler tube
Authors: Cui X.‐H. , Liu Y.‐M. , Liu X.‐F. , Zheng F.‐P. , Cao H.‐T.
Published: January 2014

The non‐destructive inspection method of scale on the inner wall of the ferritic steel and austenitic steel of high temperature boiler tube and the application effect were introduced in our work. The risk of scale exfoliation on the inner wall was also assessed. The risk of tube burst caused by scale exfoliation and accumulation, was reduced greatly, or even avoided by means of the change or treatment of high‐risk tube confirmed by non‐destructive inspection method.