bluuebunny/crossref_metadata_2025 huggingface dataset:
Large Epidemiological Influenza A Outbreak in a Teaching Hospital from Guatemala City
Authors: Mejía Carlos , Silvestre Monica , Cazali Iris , García Judith , Sánchez Ruth , García Leticia , Castillo Leticia , Escobar Ingrid , Terraza Sandra
Published: August 2012

Objective. To describe the characteristics and interventions to control a large epidemiological Influenza A Outbreak. Methods. During the months of February to April 2006, a large outbreak of Influenza A was detected, which affected Health Care Workers and hospitalized patients in a large teaching Hospital in Guatemala City. Interventions to interrupt transmission were implemented and included barrier methods (N95 masks, respiratory isolation measures, etc.) and enhanced hand hygiene, vaccination of healthy Health Care Workers (HCW), restrictions for patient visits. Results. From February to April 2006, 59 hospitalized patients diagnosed with Influenza A. 19 AIDS patients (mortality: 71%) and 5/40 (12.5%) in other diseases: cancer (3), severe cardiac failure (1) and severe malnutrition (1). The attack rate at day 20 in doctors and medical students was 21% while in other HCW it was 10.5%. Within 3 weeks of the beginning of the plan, deaths were stopped and no more cases in HCW were detected after 3 additional weeks. Conclusion. A rapid, comprehensive plan for the control of nosocomial epidemic Influenza A outbreaks is essential to limit severe morbidity and mortality in hospitals who attend large immunocompromised populations, including AIDS patients. HCW regular vaccinations programs are mandatory.
Role of Fat-Soluble Vitamins A and D in the Pathogenesis of Influenza: A New Perspective
Authors: Mawson Anthony R.
Published: August 2012

Reduced exposure to solar radiation, leading to a deficiency of vitamin D and hence impaired innate immunity, has been suggested as a trigger for influenza viral replication and as an explanation of seasonal influenza. Although this hypothesis accounts for many unexplained facts about the epidemiology of influenza, gaps remain in understanding the pathogenesis and manifestations of the disease. Several observations suggest a role for vitamin A compounds (retinoids) in the disease. This paper presents a new model of the etiopathogenesis of influenza, suggesting that host resistance and susceptibility depend importantly on the ratio of vitamin D to vitamin A activity. Retinoid concentrations within normal physiological limits appear to inhibit influenza pathogenesis whereas higher background concentrations (i.e., very low vitamin D : A ratios) increase the risk of severe complications of the disease. There is also evidence that influenza-induced or preexisting liver disease, diabetes, and obesity worsen the severity of infection, possibly via liver dysfunction and alterations in retinoid metabolism. The model could be tested by determining the presence of retinoids in the secretions of patients with influenza and by studies of retinoid profiles in patients and controls. Potential strategies for prevention and treatment are discussed.
Overdiagnosis and Overtreatment of Malaria in Children That Presented with Fever in Lagos, Nigeria
Authors: Oladosu Oladipo O. , Oyibo Wellington A.
Published: August 2012

Background. Malaria diagnosis has been largely done clinically. The implication is the likely overdiagnosis of malaria when diagnosis is done soley on the basis of symptoms. Methods. Parasitological diagnosis was done among 1211, 0–12 years old febrile children that attended a Primary Health Centre in Lagos, Nigeria, who were diagnosed clinically and treated based on symptoms. Results. A total of 251 of 1,211 (20.7%) children less than 12 years old and 174 of the 1,027 of children 0–≤5 yrs (16.9%) were slide positive while 853 (83.1%) of 0–≤5 yrs that were slide negative were treated with Artemisinin based combination therapies (ACTs) in line with the Integrated Management of Childhood Infectioins (IMCI) guidelines and standard practice of the Clinic. Chills, diarrhoea, convulsions, headache, cough, respiratory distress, inactivity, loss of apetite, and vomiting occured significantly in the 0–≤5 and >5–12 years old malaria negative children. Conclusions. Overdiagnosis and overtreatment of malaria in this study was high. Therefore, malaria medicines should be prescribed on the basis of parasitological confirmation of all suspected malaria cases. The availability of quality-assured malaria rapid diagnostic tests (RDTs) is a useful tool to confirm malaria cases while the cause of the non-malaria fevers can be followed up and managed appropriately.
Die virtuelle Kommunalverwaltung
Authors: Mehlich Harald , Postler Jürgen
Published: August 2012

eGovernment steht für einen neuartigen Typ der Verwaltungsmodernisierung. Das Internet ermöglicht flächendeckend eine behördenübergreifende Leistungserstellung. Speziell im kommunalen Sektor haben sich innovative Formen der Verwaltungskooperation herausgebildet, die über den traditionellen Zweckverband hinausweisen, jedoch bisher kaum erschlossen sind. Beispiele sind Einer-für-Alle-Dienste, regionale Dienstleistungsverbünde, kommunale Allianzen oder standortverteilte Verwaltungsfusionen. Mit behördenübergreifenden Leistungsnetzwerken vollzieht sich eine parallele Entwicklung zu den virtuellen Organisationen im Privatsektor.

Innovative Ansätze der Verwaltungskooperationen werden anhand der Ergebnisse einer bundesweiten empirischen Untersuchung im Detail dargestellt. Es werden Entwicklungspotentiale analysiert sowie Transferperspektiven für die kommunale Praxis aufgezeigt. Daneben werden mögliche Beschäftigungseffekte in einer zunehmend virtualisierten Kommunalverwaltung angesprochen.

Das Werk wendet sich an Studierende und Lehrende aus den Verwaltungs- und Sozialwissenschaften und der Verwaltungs- und Wirtschaftsinformatik sowie Fach- und Führungskräfte aus der kommunalen Praxis.

Die Autoren blicken auf langjährige Erfahrungen in der kommunalen Beratungspraxis und beim IT-Einsatz in der öffentlichen Verwaltung zurück.
Isolation of Monoclonal Antibody Charge Variants by Displacement Chromatography
Authors: McAtee C. Patrick , Hornbuckle Jacob
Published: August 2012

This unit discusses the important parameters in designing and optimizing a separation of monoclonal antibody (mAb) charge variants from process streams by ion‐exchange displacement chromatography, including sample preparation and selection of matrix, column, and appropriate buffer. A protocol is provided for determination of optimal column binding and displacement conditions, including cleaning and regeneration of the displacement columns. Curr. Protoc. Protein Sci. 69:8.10.1‐8.10.13. © 2012 by John Wiley & Sons, Inc.
Introduction to Peptide Synthesis
Authors: Stawikowski Maciej , Fields Gregg B.
Published: August 2012

A number of synthetic peptides are significant commercial or pharmaceutical products, ranging from the dipeptide sugar substitute aspartame to clinically used hormones such as oxytocin, adrenocorticotropic hormone, and calcitonin. This unit provides an overview of the field of synthetic peptides and proteins. It discusses selecting the solid support and common coupling reagents. Additional information is provided regarding common side reactions and synthesizing modified residues. Curr. Protoc. Protein Sci. 69:18.1.1‐18.1.13. © 2012 by John Wiley & Sons, Inc.
A New Mode of Cyclization of Enynes: Synthesis of Cycloalkyl Ketones through a Platinum‐Catalyzed Hydrative Cycloisomerization Reaction
Authors: Pardo Pilar , Fernández Amadeo , Fañanás Francisco J. , Rodríguez Félix
Published: August 2012

A new platinum‐catalyzed cascade reaction that proceeds through an unusual cyclization pathway of enyne derivatives is described. This operationally simple, air‐ and moisture‐tolerant reaction affords cycloalkyl ketone derivatives in a straightforward manner. The reaction can be considered as an unprecedented abnormal platinum‐catalyzed cyclization of enynes. The role of the platinum catalyst promoting at least three different reactions in this auto‐tandem catalytic process should also be remarked. The reaction also includes an unusual site‐selective hydration of a practically symmetrical carbon‐carbon triple bond directed by a hydroxy group. In this work we also describe the first platinum‐catalyzed intramolecular hydroalkylation of an unactivated olefin with a simple dialkyl ketone.
Moderne Aspekte der elektrochemischen Energiespeicherung
Authors: Vielstich Wolf
Published: August 2012

Seit etwa einem Jahrzehnt werden international große Anstrengungen gemacht, neue Systeme für die elektrochemische Energiespeicherung zu entwickeln. Um den gegenwärtigen Stand zu beschreiben, werden zunächst die prinzipiellen Möglichkeiten der elektrochemischen Speicherung kurz diskutiert. Die zur Zeit die Entwicklung beherrschenden Probleme, ausgehend vom Studium der Grundlagen bis zur technischen Realisierung, werden angeführt. Stellvertretend für die große Zahl neuer Systeme werden vier charakteristische Speicher näher behandelt: die Redox‐Zelle, die Ni/H2‐Zelle, der Gasakku und die Natrium/Schwefel‐Batterie. Anschließend wird auf die Anwendung in der Elektrotraktion eingegangen.
Brennstoffzellenaggregat mit Wolframcarbid als Anodenkatalysator
Authors: Fleischmann R. , Böhm H.
Published: August 2012

Es wurde eine phänomenologische Deutung der Aktivität des Anodenkatalysators Wolframcarbid versucht, unter Heranziehung der Bestimmung der Wasserstoffadsorption aus der Gasphase, verschiedener Oberflächenanalysenmethoden und unterschiedlicher elektrochemischer Messungen. — Darüber hinaus ist der Aufbau eines Brennstoffzellenaggregates auf der Basis von porösen Gasdiffusionselektroden mit Kohle/Wolframcarbid bzw. Kohle/Platin dargestellt.
Rapid Photoreduction of Methyl Viologen with Visible Light using Metal‐Phthalocyanines as Sensitizers
Authors: Tanno Takashi , Wöhrle Dieter , Kaneko Masao , Yamada Akira
Published: August 2012

Metal phthalocyanines (MtPc), which are corresponding in their structure to the natural porphines, are interesting in solar energy conversion. The MtPc show activity as sensitizers in photoredox reactions with the aim of H2‐evolution from water. Methyl viologen is reduced through the MtPc effectively in quantum yields till 47% in an organic solvent/water mixture.
Photoreduction Processes on n‐TiO2 Electrodes
Authors: Sprünken H.‐R. , Schumacher R. , Schindler R. N.
Published: August 2012

Photoelectrochemical processes are repeatedly suggested to be utilized for the conversion of light into electrical and/or chemical energy. This study reports on photoreduction processes which can be obtained on cathodically polarized n‐TiO2 electrodes when reducible species such as O2, Fe3+, Ce4+, Fe(CN)3‐6, and H2O2 are present in the electrolyte. The changes of photoreduction are investigated as function of the amount of reducible species transported to the surface as well as the wavelength and intensity of the incident light. It is shown that under specific experimental conditions the cathodic quantum efficiency ηc can reach values up to 1. An energy scheme is suggested to explain the mechanism which is responsible for the photoreduction process. In this scheme a broad distribution of surface states is introduced which covers the forbidden gap of the semiconductor from a mid‐gap position up to levels close to the tower edge of the conduction band ECB. It is assumed that these surface states mediate the transfer of electrons and holes from the illuminated electrode to the solution. Possible reaction channels are discussed.
Stoichiometry of Proton Translocation during Photosynthesis
Authors: Rathenow M. , Rumberg B.
Published: August 2012

Formation of ATP in photosynthesis takes place at the expense of free energy stored in the gradient of protons across the thylakoid membrane. Set up of the proton gradient is accomplished by the light‐driven electron transport reactions. The stoichiometry of H+ translocation across the thylakoid membrane is determined with respect to electron flow and ATP synthesis. Direct information is obtained on the basis of the H+ flux measurement. Depending on the experimental conditions two or three H+ are translocated from outside into the aqueous inner phase of the thylakoid vesicles for each electron which is transferred through the electron transport chain. Three H+ are translocated from inside to outside across the ATPase for each ATP molecule which is synthesized. Mechanistic and energetic consequences are discussed.
Orientation Correlation and Dielectric Relaxation of the Zwitterionic Head Groups of Dimyristoyl‐Lecithin Multi‐Bilayer Vesicles
Authors: Kaatze Udo , Henze Rolf
Published: August 2012

The spectrum of the complex permittivity of a colloidal aqueous dimyristoyl‐lecithin solution has been measured as a function of time. The change in the dielectric properties of bilayers was observed during the growth of the vesicles (after first small aggregates had been produced by sonication). The measurements were performed in the spectral range from 100 kHz to 40 MHz by fast response time domain spectroscopy. The data are phenomenologically treated in terms of a Debye relaxation spectral function and are also discussed on the basis of a theoretical model of the solutions. — The study supports the conception of a domain structure of the bilayer surface. It is shown, that the dielectric domains, which are characterized by a pronounced orientation correlation of the zwitterions, increase in size if the radius of curvature of the bilayers increases. There is also a strong relation between the dielectric relaxation time and the orientation correlation of the head groups. This result indicates that the reorientation of the zwitterions is a collective phenomenon. With respect to the kinetics of the process of vesicle growth, the data show a particularly high rate of increase in the vesicle size near the crystalline/liquid‐crystalline phase transition temperature of the bilayer system.
pH‐Dependent Fluorescence Spectroscopy, 8 [1]: Photochemical Reversible Ring Opening of 4‐Phenylumbelliferone
Authors: Wolfbeis Otto S. , Lippert Ernst , Schwarz Helmut
Published: August 2012

The pH‐dependent absorption and fluorescence spectra of 4‐phenylumbelliferone (4‐PU) are reported. 4‐PU, which is a model for several natural compounds, shows an unusual behaviour in fluorescing due to a species formed in acidic solutions by an adiabatic photoreaction during the lifetime of the excited state. This fluorescent species is shown to be either a phototautomer or, more likely, a quinoid ketene phototautomer. The latter can be trapped by H2 18O to form an 18O‐enriched coumarin dye, which is identified using high resolution mass spectrometry.
Spektroskopische Eigenschaften von Silacyclopentadienderivaten
Authors: Hennig H. , Heckner K.‐H. , Pavlov A. A. , Kuzmin M. G.
Published: August 2012

Die elektronischen Absorptions‐ und Fluoreszenzspektren sowie andere spektroskopische Parameter (Extinktionskoeffizienten, Fluoreszenzlebensdauern, Fluoreszenzquantenausbeuten) von Silacycloheptadienderivaten in Dioxan wurden bestimmt und der Einfluß der Substituenten auf diese Parameter diskutiert. Die starke Zunahme der strahlungslosen Desaktivierung bei der Einführung von Phenylgruppen in die 3‐ und 4‐Position des Silacyclopentadienringes wird durch erhöhte innere Konversion, verursacht durch die Rotationsschwingung der Phenylgruppen, erklärt. Der Vergleich der spektroskopischen Eigenschaften von 1,2,3,4,5‐Pentaphenylsilacyclopentadien mit 1,2,3,4,5‐Pentaphenylcyclopentadien und 1‐Methyl‐1,2,3,4,5‐Pentaphenylsilacyclohexadien (2,4) zeigt, daß die Einführung des Si‐Atoms in den Cyclopentadienring eine Absenkung der elektronischen Energiezustände des Moleküls bewirkt. Diese wird durch d,π‐Wechselwirkung des Si‐Atoms mit dem π‐System des Moleküls erklärt.
Liquid Mixtures of n‐Alkane Pairs: Prediction of Excess Properties from the Flory Theory without Using Solution Data
Authors: Liebermann Ernst
Published: August 2012

Flory's theory is applied to predict excess molar volumes VE and enthalpies of mixing HE from the PVT behavior of the pure liquid n‐alkanes. The number of necessary pure‐component data is kept to a minimum: VE is obtained from the molar volumes of the aliphatic hydrocarbons and their dependence on temperature, whereas calculation of HE requires also their dependence on pressure. Used equations are free from empirical parameters and need not be fitted to any solution property.
Heavy Atom Substituents as Molecular Probes for Solvent Effects on the Dynamics of Short‐lived Triplet Exciplexes
Authors: Winter Gerhard , Steiner Ulrich
Published: August 2012

The influence of heavy atom substituents (Br, I) in the electron donor aniline on the electron transfer reaction with thiopyronine triplet is investigated by flash spectroscopy in solvents of different viscosity and polarity. Triplet quenching constants and radical yields are determined. The results are analysed in terms of decay constants of an intermediate triplet exciplex where the heavy atom substituents significantly enhance the intersystem crossing process leading to singlet ground state formation and thus diminishing the radical yield due to exciplex dissociation. The sensitivity of the radical yield to solvent effects is strongly enhanced by heavy atom substitution though the solvent effects proper on the exciplex dynamics are substituent independent. The heavy atom effect is used to study the solvent cage effect on exciplex dissociation by means of viscosity variation. The exciplex dissociation lifetime is proportional to solvent viscosity, however, it contains a constant contribution which may be attributed to exciplex bonding. By means of the heavy atom probes it is found that increasing solvent polarity intersystem crossing in the exciplex is favored over exciplex dissociation into radicals. A tentative explanation is given in terms of solvent polarity dependence of the electronic energy gap between exciplex and corresponding Franck‐Condon ground state.
Students' understanding of external representations of the potassium ion channel protein part II: Structure–function relationships and fragmented knowledge
Authors: Harle Marissa , Towns Marcy H.
Published: August 2012

Research that has focused on external representations in biochemistry has uncovered student difficulties in comprehending and interpreting external representations. This study focuses on students' understanding of three external representations (ribbon diagram, wireframe, and hydrophobic/hydrophilic) of the potassium ion channel protein. Analysis of the interview data demonstrates that students were able to use the ribbon structures and polarity of the cell membrane to help support claims about the protein's orientation and interactions within the cell membrane. Students expressed fragmented understandings of the interactions between the potassium ion and the aqueous solution outside/inside of the cell membrane. Suggestions for instruction are to probe student understanding to help students activate prior knowledge and to help them build a more connected set of concepts pertaining to protein structure and function.
Bimetallic Au–Pd Nanoparticles Confined in Tubular Mesoporous Carbon as Highly Selective and Reusable Benzyl Alcohol Oxidation Catalysts
Authors: Hao Yan , Hao Guang‐Ping , Guo De‐Cai , Guo Chun‐Zao , Li Wen‐Cui , Li Ming‐Run , Lu An‐Hui
Published: August 2012

Size‐uniform and highly dispersed bimetallic Au–Pd nanoparticles were formed in situ and confined in tubular mesoporous carbon by successive incipient wetness impregnation and a thermal annealing method. The bimodal mesoporous carbon (CMK‐5) encapsulated Au–Pd nanoparticles with 1 wt % metal loading enables superior activity compared with mono‐modal mesoporous carbon for benzyl alcohol oxidation. A conversion of >99 % and selectivity of >99 % can be reached within 3 h under mild conditions, for example, at 80 °C and at atmospheric pressure. It is found that during the catalyst preparation, the Au and Pd precursor impregnation sequence is a key factor to the formation of Au–Pd nanoparticles under identical conditions. A relatively high activity is realized by the first impregnation of the Au precursor, followed by the second impregnation of the Pd precursor. The crystalline structure and distribution of Au–Pd nanoparticles are characterized by high‐resolution transmission electron microscopy (HRTEM), energy‐dispersive X‐ray spectroscopy (EDX), and XRD. It is found that a larger proportion of surface‐exposed Pd atoms in Au–Pd nanoparticles have a positive effect on catalytic activity. The Au–Pd nanoparticles have a narrow size distribution that is concentrated at approximately 4 nm. TEM and N2 adsorption results reveal that the catalyst has a large surface area and well‐developed bimodal pore interconnectivity, which contribute to its excellent activity. The used catalyst retained a high selectivity but conversion decreased with recycling. The deactivation mechanism was attributed to the tiny amount of incompletely removed benzaldehyde adsorbed onto the active surface, which blocked access from the active sites to benzyl alcohol. Importantly, the used catalyst can be recovered by a simple heat treatment at 200 °C in air after the catalytic cycles have completed; the adsorbed benzaldehyde is removed from the active surface. Hence, Au–Pd nanoparticles confined in tubular mesoporous carbon can be used as an alternative method to develop highly dispersed nanocatalysts to improve catalytic efficiency.
Synthesis and Properties of Thiophene‐Fused Benzocarborane
Authors: Morisaki Yasuhiro , Tominaga Masato , Chujo Yoshiki
Published: August 2012

The o‐carborane‐based π‐conjugated compound, benzocarborano‐ [2,1‐b:3,4‐b′]dithiophene was synthesized. Its crystal structure revealed high coplanarity for the two thiophene rings of the 2,2′‐bithiophene skeleton, which is fixed in the cisoid structure by the o‐carborane unit. Theoretical calculations indicated non‐aromaticity for its center C6 ring moiety as well as decreased HOMO and LUMO levels. The o‐carborane moiety provides an electron‐withdrawing character to the 2,2′‐bithiophene unit through an inductive effect.
Study of children evacuation from pre‐school education institutions
Authors: Kholshchevnikov V. V. , Samoshin D. A. , Parfyonenko A. P. , Belosokhov I. P.
Published: August 2012

This paper deals with research into the evacuation of children from pre‐school educational institutions. The research was designed to determine possible values for their pre‐movement time and to thoroughly investigate the parameters of their movement along the emergency escape routes. All the stages of the research conducted are described including the preparation and arrangements for the actual observation studies and the collection of basic empirical data and their statistical treatment. This includes the analysis of the pre‐movement time for pre‐school educational institutions, a theoretical analysis for establishing the relationships between speed and density of flows of children of different age groups during their upward and downward movement on stairs, through door openings, along horizontal routes at a normal walking speed, and while running. It also includes the categorization of movement by a degree of emotional state and psychological abilities of those people involved. The use of the results obtained for evacuation planning under various conditions in pre‐school educational institutions is also discussed. Copyright © 2012 John Wiley & Sons, Ltd.
Exploring Data From Genetic Association Studies Using Bayesian Variable Selection and the Dirichlet Process: Application to Searching for Gene × Gene Patterns
Authors: Papathomas Michail , Molitor John , Hoggart Clive , Hastie David , Richardson Sylvia
Published: August 2012

We construct data exploration tools for recognizing important covariate patterns associated with a phenotype, with particular focus on searching for association with gene‐gene patterns. To this end, we propose a new variable selection procedure that employs latent selection weights and compare it to an alternative formulation. The selection procedures are implemented in tandem with a Dirichlet process mixture model for the flexible clustering of genetic and epidemiological profiles. We illustrate our approach with the aid of simulated data and the analysis of a real data set from a genome‐wide association study.
Combining Family and Twin Data in Association Studies to Estimate the Noninherited Maternal Antigens Effect
Authors: Balliu Brunilda , Tsonaka Roula , van der Woude Diane , Boehringer Stefan , Houwing‐Duistermaat Jeanine J.
Published: August 2012

It is hypothesized that certain alleles can have a protective effect not only when inherited by the offspring but also as noninherited maternal antigens (NIMA). To estimate the NIMA effect, large samples of families are needed. When large samples are not available, we propose a combined approach to estimate the NIMA effect from ascertained nuclear families and twin pairs. We develop a likelihood‐based approach allowing for several ascertainment schemes, to accommodate for the outcome‐dependent sampling scheme, and a family‐specific random term, to take into account the correlation between family members. We estimate the parameters using maximum likelihood based on the combined joint likelihood () approach. Simulations show that the is more efficient for estimating the NIMA odds ratios as compared to a families‐only approach. To illustrate our approach, we used data from a family and a twin study from the United Kingdom on rheumatoid arthritis, and confirmed the protective NIMA effect, with an odds ratio of 0.477 (95% CI 0.264–0.864).
Sonographic findings in two cases of complicated pregnancy in women previously treated with endometrial ablation
Authors: Holt Roxane , Santiago‐Muñoz Patricia , Nelson David B. , Twickler Diane
Published: August 2012

When medical therapy fails for menorrhagia in a premenopausal woman, minimally invasive endometrial ablation can be used as a conservative management alternative to hysterectomy. Endometrial ablation alone is not considered effective contraception, and women of reproductive age can become pregnant after ablative therapy. We now present two cases of pregnancy after endometrial ablation and associated imaging where both cases required cesarean hysterectomy due to post partumhemorrhage. Pregnancy after endometrial ablation incurs increased morbidity and diagnostic dilemmas. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound 41:566–569, 2013.
Computational and experimental studies of an orthopedic implant: MRI‐related heating at 1.5‐T/64‐MHz and 3‐T/128‐MHz
Authors: Liu Yan , Chen Ji , Shellock Frank G. , Kainz Wolfgang
Published: August 2012

Purpose:

To use numerical modeling to predict the worst‐case of magnetic resonance imaging (MRI)‐induced heating of an orthopedic implant of different sizes under 1.5‐T/64‐MHz and 3‐T/128‐MHz conditions and to apply the experimental test to validate the numerical results for worst‐case heating.

Materials and Methods:

Investigations of specific absorption rate (SAR) and the temperature rise of an orthopedic implant of different sizes within a standard phantom were accomplished by numerical finite‐difference time‐domain modeling and experimental measurements. MRI‐related heating experiments were performed using standardized techniques at 1.5‐T/64‐MHz and 3‐T/128‐MHz.

Results:

The numerical modeling results indicated that the induced energy deposition is almost linearly related to the dimension of the orthopedic implant when it is less than 100 mm for 1.5‐T/64‐MHz and 3‐T/128‐MHz conditions. At 3‐T/128‐MHz, when the dimension is greater than 100 mm, the linear relation does not exist, which suggests a wavelength effect at higher frequency. Higher temperature rises occurred at 1.5‐T/64‐MHz MRI than at 3‐T/128‐MHz for both numerical modeling and experimental studies.

Conclusion:

The numerical technique predicted which device size had maximum heating and its location. Temperature rise data agreed well with thermal simulation results. The presented method proved to be suitable to assess MRI‐induced heating of complex medical implants. J. Magn. Reson. Imaging 2013;37:491–497. © 2012 Wiley Periodicals, Inc.
Exploring the nucleophilicity of N,N′‐diamidocarbenes: Heteroallenes and related compounds as coupling reagents
Authors: Lee Young‐Gi , Moerdyk Jonathan P. , Bielawski Christopher W.
Published: August 2012

The propensity of a stable N,N′‐diamidocarbene (DAC) to react with various heteroallenes was explored. The DAC condensed with 4‐nitrophenyl azide as well as 4‐nitrophenyl isothiocyanate to afford the respective acyclic triazene or zwitterionic dihydropyrimidinium imidothiolate products. Treating the DAC with two equivalents of 3‐nitrophenyl isocyanate afforded an iminooxazolidinone rather than the expected hydantoin. Similarly, the addition of diphenylketene to the DAC afforded a dioxolane product, whereas analogous reactions involving N‐heterocyclic carbenes (NHCs) resulted in betaine adducts. Although the DAC as well as various diaminocarbenes condensed with 2,6‐dimethoxyphenyl nitrile N‐oxide to afford the respective nitrosoethylenes, only the six‐membered DAC and NHC adducts rearranged to the corresponding nitrones at elevated temperature. Copyright © 2012 John Wiley & Sons, Ltd.
pH effects on binding between the anthrax protective antigen and the host cellular receptor CMG2
Authors: Rajapaksha Maheshinie , Lovell Scott , Janowiak Blythe E. , Andra Kiran K. , Battaile Kevin P. , Bann James G.
Published: August 2012

The anthrax protective antigen (PA) binds to the host cellular receptor capillary morphogenesis protein 2 (CMG2) with high affinity. To gain a better understanding of how pH may affect binding to the receptor, we have investigated the kinetics of binding as a function of pH to the full‐length monomeric PA and to two variants: a 2‐fluorohistidine‐labeled PA (2‐FHisPA), which is ∼1 pH unit more stable to variations in pH than WT, and an ∼1 pH unit less stable variant in which Trp346 in the domain 2β3‐2β4 loop is substituted with a Phe (W346F). We show using stopped‐flow fluorescence that the binding rate increases as the pH is lowered for all proteins, with little influence on the rate of dissociation. In addition, we have crystallized PA and the two variants and examine the influence of pH on structure. In contrast to previous X‐ray studies, the domain 2β3‐2β4 loop undergoes little change in structure from pH ∼8 to 5.5 for the WT protein, but for the 2‐FHis labeled and W346F mutant there are changes in structure consistent with previous X‐ray studies. In accord with pH stability studies, we find that the average B‐factor values increase by ∼20–30% for all three proteins at low pH. Our results suggest that for the full‐length PA, low pH increases the binding affinity, likely through a change in structure that favors a more “bound‐like” conformation.
Test generation from state based use case models
Authors: Nogueira Sidney , Sampaio Augusto , Mota Alexandre
Published: August 2012

We present a strategy for the automatic generation of test cases from parametrised use case templates that capture control flow, state, input and output. Our approach allows test scenario selection based on particular traces or states of the model. The templates are internally represented as CSP processes with explicit input and output alphabets, and test generation is expressed as counter-examples of refinement checking, mechanised using the FDR tool. Soundness is addressed through an input–output conformance relation formally defined in the CSP traces model. This purely process algebraic characterisation of testing has some potential advantages, mainly an easy automation of conformance verification and test case generation via model checking, without the need to develop any explicit algorithm.
Selected topics in arctic atmosphere and climate
Authors: Perrie William , Long Zhenxia , Hung Hayley , Cole Amanda , Steffen Alexandra , Dastoor Ashu , Durnford Dorothy , Ma Jianmin , Bottenheim Jan W. , Netcheva Stoyka , Staebler Ralf , Drummond James R. , O’Neill N. T.
Published: August 2012

This paper summarizes the main elements of four IPY projects that examine the Arctic Atmosphere. All four projects focus on present conditions with a view to anticipating possible climate change. All four investigate the Arctic atmosphere, ocean, ice, and land interfacial surfaces. One project uses computer models to simulate the dynamics of the Arctic atmosphere, storms, and their interactions with the ocean and ice interface. Another project uses statistical methods to infer transports of pollutants as simulated in large-scale global atmospheric and oceanic models verifying results with available observations. A third project focuses on measurements of pollutants at the ice-ocean–atmosphere interface, with reference to model estimates. The fourth project is concerned with multiple, high accuracy measurements at Eureka in the Canadian Archipelago. While these projects are distinctly different, led by different teams and interdisciplinary collaborators, with different technical approaches and methodologies, and differing objectives, they all strive to understand the processes of the Arctic atmosphere and climate, and to lay the basis for projections of future changes. Key findings include:

• Decreased sea ice leads to more intense storms, higher winds, reduced surface albedo, increased surface air temperature, and enhanced vertical mixing in the upper ocean.

• Arctic warming may affect toxic chemicals by remobilizing persistent organic pollutants and augmenting mercury deposition/retention in the environment.

• Changes in sea ice can dramatically change processes in and at the ice surface related to ozone, mercury and bromine oxide and related chemical/physical properties.

• Structure and properties of the Arctic atmospheric—troposphere to stratosphere—and tracking of transport of pollution and smoke plumes from mid-latitudes to the poles.
Finding good biomarkers for sarcopenia
Authors: Scharf Gesine , Heineke Joerg
Published: August 2012

The term sarcopenia describes the age‐related loss of skeletal muscle mass and function. While this process, in principal, occurs in every adult person and already starts around the age of 40, it is associated with disability, morbidity, and increased mortality in some individuals. In the absence of clear clinical manifestation, we today lack the ability to differentiate between physiological and pathological sarcopenia. In this regard, we need good biomarkers that can be quantified in a reliable, cost‐effective manner and that guide diagnosis and therapy of pathological sarcopenia in routine clinical practice and clinical trials. We suggest that a combination of serum markers, diagnostic imaging, and functional tests of muscle function would constitute an ideal biomarker panel. Importantly, sarcopenia biomarkers will have to be tested and validated in clinical trials.
Collection of volatiles from honeybee larvae and adults enclosed on brood frames
Authors: Carroll Mark J. , Duehl Adrian J.
Published: August 2012

We describe a system for the in situ collection of volatiles from bees enclosed on a standard Langstroth frame face. The system includes an observation frame consisting of a glass plate and an aluminum frame that encloses a single frame face. A push–pull airflow system and an in-line volatile collection filter allow for air exchange and headspace volatile capture. This system can provide insight into colony chemical communication. The emissions of four compounds (2-heptanone, methyl benzoate, decanal, and 3-carene) associated with adult bees or colony materials remained steady or increased slightly in repeated collections from frames with maturing larvae. The emissions of the larval food component octanoic acid reflected changes in food consumption patterns by differently aged larvae. The production of the primer pheromone E-β-ocimene was greatest in comb containing young larvae and recently capped brood, but was lower on comb with capping larvae.
Moderators of Workplace Aggression: The Influences of Social Support and Training
Authors: Brown Valerie M. , Loh Jennifer (M.I.) , Marsh Nigel V.
Published: August 2012

Reception and administrative employees may be particularly vulnerable to patient aggression in mental health services. This study examined whether satisfaction with social support and primary aggression training moderated the effects of perceived aggression on psychological distress and somatic symptoms in a sample of 101 employees. The biophysical model of threat and challenge, the stressor-stress-strain model, and the stress-buffering hypothesis served as theoretical frameworks. Results showed perceived aggression correlated positively with psychological distress, but not with somatic symptoms. Significant interactions were found for social support (buffering effect) and training (interaction effect) for somatic symptoms, but not for psychological distress. It is suggested that, for somatic symptoms, the moderation effects of social support and training on perceived aggression involve similar mechanisms (increased knowledge, self-esteem, perceived control, coping capacity). These findings provide support for the benefits of staff training and the incorporation of knowledge-based components in training programs.
Additive and dominance effects of the αs1-casein locus on milk yield and composition traits in dairy goats
Authors: Vázquez-Flores Felicitas , Montaldo Hugo H , Torres-Vázquez José A , Alonso-Morales Rogelio A , Gayosso-Vázquez Amanda , Valencia-Posadas Mauricio , Castillo-Juárez Héctor
Published: August 2012

The objective of this study was to evaluate the effects of the CSN1S1 locus polymorphism on 305-d records of milk, fat, protein, lactose and total solids yields, fat, protein, lactose and total solids contents in Mexican dairy goats. A total of 514 lactation records belonging to Alpine (n=60), Saanen (n=105) and Toggenburg (n=74) goats, born from 2003 to 2006 in three herds were used. Discrimination between alleles E, F, N, A* (CSN1S1 A, G, H, I, O1 and O2) and B* (CSN1S1 B1, B2, B3, B4, C and L) were made by amplification of fragments of the gene CSN1S1 and digestion with the restriction endonuclease XmnI. In order to estimate additive and dominance effects, data sets including (1) all genotypes, and (2) only homozygote genotypes, were analysed using linear mixed models. The allele A*, had significant additive effects for protein content (0·21±0·07%;P=0·002) and total solids content (0·66±0·23%;P=0·005) when compared with allele F. An unfavourable additive effect of allele A* on milk yield was found in the Alpine breed (−81·4±40·2;P=0·046) when compared with allele F. Favourable dominance effects were found for some genotypes (P<0·05) for milk yield (A*N and B*N), fat yield (A*N and B*E), protein yield (A*N and B*E), lactose yield (A*N) and total solids yield (A*N). Also, unfavourable dominance effects were found (P<0·05) for protein content (A*B* and A*N) and total solids content (A*B*, A*N, and A*F). Allele A* was the only one with a positive effect for protein content. Significant allele-year interaction effects were also observed. The presence of significant dominance effects, estimated between specific pairs of alleles, challenged the purely additive nature of the genetic effect at the CSN1S1 locus. Implications from use of CSN1S1 effects in goat breeding programmes are presented.
Effect of mid-line or low-line milking systems on milking characteristics in goats
Authors: Manzur Alberto , Díaz José-Ramón , Mehdid Amine , Fernández Nemesio , Peris Cristòfol
Published: August 2012

Two experiments were carried out to compare mechanical milking in mid-level (ML) and low-level (LL) milkline in goats. The first trial used 40 intramammary infection (IMI)-free goats that had been milked in ML during a pre-experimental period of 4±1 weeks post partum. These animals were divided into two groups (n=20), randomly assigning each group to ML or LL milking for a 17-week experimental period. During this period, several strategies were applied to increase teat exposure to pathogens in both experimental groups. The IMI rate was the same in both experimental groups (30% of goats), although the majority of new infections appeared earlier in ML (weeks 1–5) than in LL (weeks 7–16). Teat-end vacuum range (maximum minus minimum vacuum) was higher in ML than in LL, but no significant differences were found in the remaining variables [milk production and composition, somatic cell count (SCC), frequency of liner slips+teatcups fall off]. In the second experiment, in a crossover design (54 goats in fourth month of lactation; 2 treatments, ML and LL, in 2 experimental periods each lasting 1 week) it was observed that both the milk fractioning (reduced machine milk and increased machine stripping) and average machine milk flow worsened slightly in ML milking; in contrast, no differences were observed in total milking time or teat thickness changes after milking. It was concluded that the differences found between ML and LL are not sufficiently important to discourage breeders from using ML in goat milking.
Development mechanism of cathode surface plasmas of high current pulsed electron beam sources for microwave irradiation generation
Authors: Li Limin , Chang L. , Zhang L. , Liu J. , Chen G. , Wen J.
Published: August 2012

This paper presents the development mechanism of surface plasmas of carbon-fiber-cathode electron beam source and its effects on the operation of a high-power microwave source, reflex triode vircator powered by about 400 kV, 9 kA, about 350 ns pulsed power accelerator. Based on the current and voltage characteristics of diodes using carbon fiber cathode, the axial expansion velocity is 1.2 cm/μs and the delay time of explosive emission is 2 ns. Further, the comparison of carbon fiber and stainless steel cathodes is made. It was found that the threshold electric field for carbon fiber cathode is about 25 kV/cm, and the delay time of explosive emission and threshold electric field for stainless steel cathode is, respectively, 4.5 ns and 40 kV/cm. The radial expansion velocity of individual emitting centers is estimated to be 1.2 cm/μs, equal to the axial expansion velocity, and this shows the cathode plasma spots spherically expand. In the optimal diode gap for microwave irradiation or at the average current density of 230 A/cm2using carbon fiber cathode, the screening radius was 0.67 cm, the lifetime of cathode emitting centers was about 60 ns, the cathode plasma density was 5 × 1015 cm−3, and the Debye radius of cathode plasma was <3 × 10−5 cm−3. The self-quenching behavior of explosive emission centers occurs, due to the process of cathode surface material release and cooling. The generation and self-quenching of emitting centers, and screening effect of cathode plasmas determine the increase and decrease of cathode emitting area, which is independent of the current density and background pressure. The relation between the lifetime of virtual cathode and background pressure was discussed. It was found, both theoretically and experimentally, that a lower background pressure indicates a longer microwave pulse or a better microwave waveform. It was observed by comparison that the temporary behavior of cathode emitting area is similar to the development process of microwave pulse. The changes of emitting area affects the stability of beam current injected into the virtual cathode region, further leading to the fluctuation of microwave pulse of vircator.
A story about a word: does narrative presentation promote learning of a spatial preposition in German two-year-olds?
Authors: NACHTIGÄLLER KERSTIN , ROHLFING KATHARINA J. , MCGREGOR KARLA K.
Published: August 2012

We trained forty German-speaking children aged 1;8–2;0 in their comprehension of UNTER [UNDER]. The target word was presented within semantically organized input in the form of a ‘narrative’ to the experimental group and within ‘unconnected speech’ to the control group. We tested children's learning by asking them to perform an UNDER-relation before, immediately after, and again one day after the training using familiarized and unfamiliarized materials. Compared to controls, the experimental group learned better and retained more. Children with advanced expressive lexicons in particular were aided in generalizing to unfamiliarized materials by the narrative presentation. This study extends our understanding of how narrations scaffold young children's enrichment of nascent word knowledge.
Strategic Control Modulates Working Memory-Driven Attentional Capture
Authors: Kuo Chun-Yu , Chao Hsuan-Fu , Yeh Yei-Yu
Published: August 2012

The current study used a naming task to investigate whether strategic control could modulate the process of attentional capture that is driven by working memory. The use of a naming task to engage working memory eliminates potential strategic perceptual resampling, which may have played a role in several previous studies. After naming a prime, participants performed a selection task in which they judged the direction of a moving target in each trial. Prime validity, which is the probability that the primes are identical to the selection targets, was manipulated across four experiments. The results showed that reaction times to the motion judgment were faster in the valid condition than in the invalid condition when the prime validity was 50% (Experiment 1A). These results occurred even in the presence of a highly informative spatial cue that predicted the target’s location (Experiment 4). A larger capturing effect was observed when the validity was 70% (Experiments 2 and 3). When the prime validity was lower than the chance level (0% in Experiment 1B; 15% in Experiments 2 and 3), a validity effect was not observed. Thus, the results suggest that there is a strong tendency for working memory to capture attention by default when there is no reason to avoid the influence of primes. When there is a reason to avoid the influence, strategic control modulates the attentional capture that is driven by working memory.
Do peatland microforms move through time? Examining the developmental history of a patterned peatland using ground‐penetrating radar
Authors: Kettridge Nicholas , Binley Andrew , Comas Xavier , Cassidy Nigel J. , Baird Andy J. , Harris Angela , van der Kruk Jan , Strack Maria , Milner Alice M. , Waddington James M.
Published: August 2012

Using ground‐penetrating radar (GPR) to map subsurface patterns in peat physical properties, we investigated the developmental history of meso‐scale surface patterning of microforms within a raised bog. Common offset GPR measurements were obtained along a 45‐m transect, at frequencies ranging from 100 to 900 MHz. We found that low‐frequency (central frequency < 240 MHz) GPR could not adequately represent the subsurface structures of the peatland because individual peat layers were too thin. However, more detailed high‐frequency measurements (central frequency ≥ 240 MHz) showed a striking pattern of subsurface reflections that dip consistently in a northerly direction. The angle of these dipping reflectors is calculated using a semblance algorithm and was shown to average 3.9° between a depth of 1.0 and 2.5 m. These dipping reflectors may indicate downslope migration of surface microforms during the development of the peatland. Based on the estimated angle and the rate of peat accumulation, the average rate of downslope propagation of these surface microforms is calculated at 9.8 mm per year. Further survey work is required to establish whether the downslope migration is common across the peatland.