bluuebunny/crossref_metadata_2025 huggingface dataset:
High‐sensitivity analysis of specific peptides in complex samples by selected MS/MS ion monitoring and linear ion trap mass spectrometry: Application to biological studies
Authors: Jorge Inmaculada , Casas Elisabet Miró , Villar Margarita , Ortega‐Pérez Inmaculada , López‐Ferrer Daniel , Martínez‐Ruiz Antonio , Carrera Mónica , Marina Anabel , Martínez Pablo , Serrano Horacio , Cañas Benito , Were Felipe , Gallardo José Manuel , Lamas Santiago , Redondo Juan Miguel , García‐Dorado David , Vázquez Jesús
Published: October 2007

Mass spectrometry (MS) is a technique of paramount importance in Proteomics, and developments in this field have been possible owing to novel MS instrumentation, experimental strategies, and bioinformatics tools. Today it is possible to identify and determine relative expression levels of thousands of proteins in a biological system by MS analysis of peptides produced by proteolytic digestion. In some situations, however, the precise characterization of a particular peptide species in a very complex peptide mixture is needed. While single‐fragment ion‐based scanning modes such as selected ion reaction monitoring (SIRM) or consecutive reaction monitoring (CRM) may be highly sensitive, they do not produce MS/MS information and their actual specificity must be determined in advance, a prerequisite that is not usually met in a basic research context. In such cases, the MS detector may be programmed to perform continuous MS/MS spectra on the peptide ion of interest in order to obtain structural information. This selected MS/MS ion monitoring (SMIM) mode has a number of advantages that are fully exploited by MS detectors that, like the linear ion trap, are characterized by high scanning speeds. In this work, we show some applications of this technique in the context of biological studies. These results were obtained by selecting an appropriate combination of scans according to the purpose of each one of these research scenarios. They include highly specific identification of proteins present in low amounts, characterization and relative quantification of post‐translational modifications such as phosphorylation and S‐nitrosylation and species‐specific peptide identification. Copyright © 2007 John Wiley & Sons, Ltd.
Breakdown of Layering in Frustrated Smectic‐A Elastomers
Authors: Kramer Dominic , Finkelmann Heino
Published: October 2007

Smectic‐A elastomers combine the positional long‐range order of mesogenic molecules in one dimension with the rubber elasticity of a polymer network. Upon mechanical deformation, completely different responses of the phase structure have been reported. We present a highly distorted system which shows a breakdown of smectic layering but no reorientation under deformation along the layer normal, while the phase structure stays unaffected under uniaxial stress in the perpendicular direction. The thermoelastic properties, macroscopic dimensions and stress–strain behaviour are investigated parallel and perpendicular to the layer normal. SAXS measurements supply evidence for a breakdown of the macroscopically ordered layer structure indicated by the small angle intensities and correlation length, whereas the orientational order is preserved. We propose defects in the smectic layer structure to be the origin of the different responses of different smectic elastomers.

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Using Solvents to Improve the Chemical Shift Differences Between Short‐Chain Branch Methines and Long‐Chain Branch Methines in Polyethylene Copolymers
Authors: Baugh Dan , Redwine O. David , Taha Angela , Reichek Ken , Potter Janece
Published: October 2007

Summary: Detection and quantification of long‐chain branches in some polyethylene copolymers is challenging due to the near coincidence of the chemical shifts for the carbons at the short‐chain and long‐chain branches present in these copolymers. The small chemical shift difference can be enhanced by changes in solvent and temperature. This allows one to use lower field magnets for some copolymers. Results are presented comparing several solvents and blends at a variety of temperatures using 500, 600 and 750 MHz spectrometers.
Metabolite quantification and high‐field MRS in breast cancer
Authors: Haddadin Ihab S. , McIntosh Adeka , Meisamy Sina , Corum Curt , Snyder Angela L. Styczynski , Powell Nathaniel J. , Nelson Michael T. , Yee Douglas , Garwood Michael , Bolan Patrick J.
Published: October 2007

In vivo 1H MRS is rapidly developing as a clinical tool for diagnosing and characterizing breast cancers. Many in vivo and in vitro experiments have demonstrated that alterations in concentrations of choline‐containing metabolites are associated with malignant transformation. In recent years, considerable efforts have been made to evaluate the role of 1H MRS measurements of total choline‐containing compounds in the management of patients with breast cancer. Current technological developments, including the use of high‐field MR scanners and quantitative spectroscopic analysis methods, promise to increase the sensitivity and accuracy of breast MRS. This article reviews the literature describing in vivo MRS in breast cancer, with an emphasis on the development of high‐field MR scanning and quantitative methods. Potential applications of these technologies for diagnosing suspicious lesions and monitoring response to chemotherapy are discussed. Copyright © 2008 John Wiley & Sons, Ltd.
Perturbation analysis for the generalized Schur complement of a positive semi‐definite matrix
Authors: Wei Musheng , Wang Minghui
Published: October 2007

Let

and S=C−BHA†B be the generalized Schur complement of A⩾0 in P. In this paper, some perturbation bounds of S are presented which generalize the result of Stewart (Technical Report TR‐95‐38, University of Maryland, 1995) and enrich the perturbation theory for the Schur complement. Also, an error estimate for the smallest perturbation of C, which lowers the rank of P, is discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Registries as a tool in evidence‐based medicine: example of KIMS (Pfizer International Metabolic Database)
Authors: Gutiérrez Lia P. , Kołtowska‐Häggström Maria , Jönsson Peter J. , Mattsson Anders F. , Svensson Dag , Westberg Björn , Luger Anton
Published: October 2007

Purpose

To evaluate the value of a registry, set in ‘real‐life practice’, as a contribution to evidence‐based medicine and to estimate the impact of information collected in such a registry, on the up to date knowledge in growth hormone (GH)‐related disorders.

Methods

Analysis of data collected prospectively for a pharmacoepidemiological registry—KIMS (Pfizer International Metabolic Database)—in assessing long‐term clinical and safety outcomes of GH treatment (Genotropin®) in patients with GH deficiency. The study was based on 11 374 treated (40 000 patient‐years of observation) and 263 untreated adult GH deficient patients from 30 countries, in whom background characteristics, clinical values such as lipids and body composition, quality of life (QoL) and GH dosage as well as safety profile were evaluated. Citation analysis for the published papers was also performed.

Results

The study depicts the clinical picture of adult patients with GH deficiency managed in current clinical settings. It confirms the features previously detected such as increased cardiovascular risk, mostly dyslipidemia and abnormal body composition as well as impaired QoL. There was considerable heterogeneity of conditions resulting in GH deficiency. The large database also enabled study of rare causes of the condition. The 31 out of 36 KIMS papers were cited 544 times, in 125 different journals.

Conclusions

These findings and the further insight into the response to GH replacement therapy show that the registry methodology is valuable for filling the gaps of information in evidence‐based medicine that cannot be addressed by clinical trials. Copyright © 2007 John Wiley & Sons, Ltd.
NiO‐induced crystallization and optical characteristics of Li2O–CaF2–P2O5 glass system
Authors: Murali Krishna G. , Gandhi Y. , Veeraiah N.
Published: October 2007

Li2O–CaF2–P2O5 glasses mixed with different concentrations of NiO (ranging from 0 mol% to 2.0 mol%) were crystallized. The samples were characterized using X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy and differential thermal analysis. Studies were extended to optical absorption and magnetic susceptibility of these glass ceramic samples. The XRD and SEM studies reveal the presence of lithium phosphate, calcium phosphate and nickel phosphate crystal phases. The optical absorption studies together with magnetic susceptibility measurements indicate a gradual transformation of nickel ions from tetrahedral sites to octahedral sites (lasing sites) as the concentration of NiO is increased beyond 0.8 mol%. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Studies on semiconductor dispersed polymer electrolyte composite (PEO:NH4ClO4 + Bi2S3)
Authors: Kumar Manoj , Chandra Amita
Published: October 2007

Polymer composites consisting of different amounts (0–10 wt%) of dispersed semiconducting Bi2S3 in the polymer electrolyte polyethylene oxide complexed with NH4ClO4 (PEO:NH4ClO4 + Bi2S3) have been prepared and characterized. The dispersal of Bi2S3 was achieved by its “in‐situ” formation in the polymeric solution by sulfuration of Bismuth nitrate by bubbling H2S. The dispersed Bi2S3 particles were found to be nano‐sized (∼20 nm) resulting in a higher band gap (∼1.8 eV) as compared to that of bulk Bi2S3 (∼1.4 eV). Detailed I –V and polarization studies show that the dispersed Bi2S3 is n‐type and a small (≤8%) electronic conductivity is introduced into the purely ionic (PEO:NH4ClO4) film making it a mixed ion + electron conducting polymer composite. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Substituent effects on the gas‐phase ring‐chain tautomerism of 3,4,5,6‐tetrahydro‐2H‐1,3‐oxazines
Authors: Juhász Márta , Fülöp Ferenc , Pihlaja Kalevi
Published: October 2007

The electron ionization mass spectra of five series of seven 2‐aryl,4‐R‐substituted (R = Me, Et, i‐Pr, t‐Bu or Ph) 3,4,5,6‐tetrahydro‐2H‐1,3‐oxazines were recorded at 14 and 70 eV in order to study the ring‐chain tautomeric equilibria in the gas phase. Certain fragment ions were associated with the ring or with the open‐chain forms of the compounds. As in chloroform solution, the electron‐withdrawing effect of the aryl substituent (p‐NO2, m‐Br, p‐Cl, H, p‐Me, p‐OMe and p‐NMe2) shifts the equilibrium towards the ring form. The correlation of ring‐chain equilibria (log K = [ring]/[chain]) with the Hammett σ+ constants of the aryl substituents was in general good or satisfactory although in some cases the p‐NMe2 did not fit these correlations. Copyright © 2007 John Wiley & Sons, Ltd.
Silicon micropillar array electrospray chip for drug and biomolecule analysis
Authors: Nissilä Teemu , Sainiemi Lauri , Sikanen Tiina , Kotiaho Tapio , Franssila Sami , Kostiainen Risto , Ketola Raimo A.
Published: October 2007

We have developed a lidless micropillar array electrospray ionization chip (µPESI) combined with mass spectrometry (MS) for analysis of drugs and biomolecules. The µPESI chip, made of silicon, contains a sample introduction spot for a liquid sample, an array of micropillars (diameter, height, and distance between pillars in the range of 15–200, 20–40, and 2–80 µm, respectively), and a sharpened tip for direct electrospray formation. The microchips were fabricated using deep reactive ion etching (DRIE) which results in accurate dimensional control. The chip, providing a reliable open‐channel filling structure based on capillary forces and a electrospray emitter tip for ionization, allows an easy operation and reliable, non‐clogging liquid transfer. The µPESI chip can be used for a fast analysis using single sampling or for continuous infusion measurements using a syringe pump for sample introduction. The µPESI‐MS shows high sensitivity, with limit of detection 30 pmol/L (60 amol or 28 fg) for verapamil measured with tandem mass spectrometry (MS/MS) and using a sample volume of 2.5 µL. The system shows also good quantitative linearity (r2 > 0.99) with linear dynamic range of at least six orders of magnitude and good ion current stability (standard deviation <5%) in 1‐h continuous flow measurement. The µPESI‐MS is shown to be a very potential method for direct analysis of drugs and biomolecules. Copyright © 2007 John Wiley & Sons, Ltd.
Covariate adjustment for two‐sample treatment comparisons in randomized clinical trials: A principled yet flexible approach
Authors: Tsiatis Anastasios A. , Davidian Marie , Zhang Min , Lu Xiaomin
Published: October 2007

There is considerable debate regarding whether and how covariate‐adjusted analyses should be used in the comparison of treatments in randomized clinical trials. Substantial baseline covariate information is routinely collected in such trials, and one goal of adjustment is to exploit covariates associated with outcome to increase precision of estimation of the treatment effect. However, concerns are routinely raised over the potential for bias when the covariates used are selectedpost hocand the potential for adjustment based on a model of the relationship between outcome, covariates, and treatment to invite a ‘fishing expedition’ for that leading to the most dramatic effect estimate. By appealing to the theory of semiparametrics, we are led naturally to a characterization of all treatment effect estimators and to principled, practically feasible methods for covariate adjustment that yield the desired gains in efficiency and that allow covariate relationships to be identified and exploited while circumventing the usual concerns. The methods and strategies for their implementation in practice are presented. Simulation studies and an application to data from an HIV clinical trial demonstrate the performance of the techniques relative to the existing methods. Copyright © 2007 John Wiley & Sons, Ltd.
Comparison of an aggregated model of a wind farm consisting of fixed‐speed wind turbines with field measurement
Authors: Perdana Abram , Uski‐Joutsenvuo Sanna , Carlson Ola , Lemström Bettina
Published: October 2007

A wind farm typically consists of a large number of wind turbines with relatively small size generators. In order to reduce computation time and complexity in power system stability studies, it is therefore desirable to aggregate wind turbines in the wind farm into a reduced number of equivalent units. The aggregation should be made without missing important properties or behaviors of wind power generation systems for the associated studies. Models of single and aggregated wind turbines are presented in the paper. The importance of induction generator and mechanical drive train models of wind turbines is examined. Simulation results of the models are then compared with field measurement data. Copyright © 2007 John Wiley & Sons, Ltd.
Preferential Efflux of Phytosterols over Cholesterol from Macrophages
Authors: Hovenkamp E. , Lourbakos A. , Duchateau G. S. M. J. E. , Tareilus E. W. , Trautwein E. A.
Published: October 2007

Phytosterols are structurally similar to cholesterol. Increased dietary intake of phytosterols effectively lowers LDL‐cholesterol. Since phytosterols are incorporated in a growing number of foods and some of the ingested phytosterols reach the circulation, accumulation of phytosterols in foam‐cell‐prone cells such as macrophages might occur. Therefore we examined the influx and efflux of phytosterols by human THP‐1 macrophages. The influx rates of methyl‐β‐cyclodextrin delivered phytosterols did not significantly differ from that of cholesterol (~3.8 pmol/min per mg cellular protein), neither did the total influx of oxidised LDL delivered phytosterols differ from that of cholesterol. The efflux of β‐sitosterol and sitostanol from preloaded THP‐1 cells to HDL was more efficient than the efflux of campesterol and cholesterol (rate constants of 0.41 ± 0.04/h, 0.62 ± 0.08/h, 0.23 ± 0.05/h and 0.29 ± 0.03/h, respectively). The efflux of β‐sitosterol was not associated with a dominant transfer to ApoA‐I, nor did ABCA1 induction‐promoted cholesterol efflux to the level observed for β‐sitosterol. Our data show that THP‐1 macrophages take up phytosterols, but have efficient mechanisms to remove phytosterols from their cellular compartments. Consequently, it is less likely that macrophages preferentially accumulate phytosterols over cholesterol and hence promote foam‐cell formation in vivo.
Lipid Classes and Fatty Acid Composition of the Tropical Nudibranch Mollusks Chromodoris sp. and Phyllidia coelestis
Authors: Zhukova Natalia V.
Published: October 2007

Two nudibranch mollusks, Chromodoris sp. and Phyllidia coelestis, collected from tropical waters of the Northwestern Pacific, were analyzed for lipids. The aim of this study was to fill the gap in knowledge of lipid biochemistry of mollusks. Phospholipids (PL) were the dominating lipid class followed by sterols (13%). Neutral lipids were not detected in Chromodoris sp. By contrast, P. coelestis contained TAG, diacylglyceryl ether, long chain alcohol and esters of sterols. Among PL, PC was predominant (about 50%); PE, PS and CAEP were almost in equal proportions. Sixty five FA were identified as methyl esters and N‐acyl pyrrolidides by GC–MS. The sea slugs exhibited a wide diversity of FA. The common marine n‐3 PUFA, 20:5n‐6 and 22:6n‐3, constituted 0.6–1.3% of the total FA, whereas n‐6 PUFA, 22:4n‐6, 20:4n‐6, and 18:2n‐6, were the main (25%). Among monounsaturated FA, 7‐21:1 was the main (up to 6.2%). The non‐methylene‐interrupted (NMI) FA were found (9.4 and 12.4%), including the known 5,11–20:2, 5,13–20:2, 7,13–22:2, 7,15–22:2 and a novel isomer 7,13–21:2 (up to 3.9%). The pathway of its biosynthesis was suggested. A series of very long chain FA (VLC FA), with the main 5,9–25:2 and 5,9–26:2, were identified. High level of VLC FA (8.7 and 11.7%) in sea slugs is apparently the result of predation on sponges. Another unique feature concerned a high abundance of various odd and branched FA (16.7 and 34%), which could have originated from the dietary origin or symbiotic bacteria. This is the first report on lipid and FA composition of nudibranchs.
FXR‐deficiency confers increased susceptibility to torpor
Authors: Cariou Bertrand , Bouchaert Emmanuel , Abdelkarim Mouaadh , Dumont Julie , Caron Sandrine , Fruchart Jean-Charles , Burcelin Rémy , Kuipers Folkert , Staels Bart
Published: October 2007

The role of the nuclear receptor FXR in adaptive thermogenesis was investigated using FXR‐deficient mice. Despite elevated serum bile acid concentrations and increased mRNA expression profiles of thermogenic genes in brown adipose tissue, FXR‐deficiency did not alter energy expenditure under basal conditions. However, FXR‐deficiency accelerated the fasting‐induced entry into torpor in a leptin‐dependent manner. FXR‐deficient mice were also extremely cold‐intolerant. These altered responses may be linked to a more rapid decrease in plasma concentrations of metabolic fuels (glucose, triglycerides) thus impairing uncoupling protein 1‐driven thermogenesis. These results identify FXR as a modulator of energy homeostasis.
Involvement of Fyn tyrosine kinase in actin stress fiber formation in fibroblasts
Authors: Xu Dan , Kishi Hiroko , Kawamichi Hozumi , Kajiya Katsuko , Takada Yuichi , Kobayashi Sei
Published: October 2007

Lysophosphatidic acid (LPA) and sphingosylphosphorylcholine (SPC) activated Fyn tyrosine kinase and induced stress fiber formation, which was blocked by pharmacological inhibition of Fyn, gene silencing of Fyn, or dominant negative Fyn. Overexpressed constitutively active Fyn localized at both ends of F‐actin bundles and triggered stress fiber formation, only the latter of which was abolished by Rho‐kinase (ROCK) inhibition. SPC, but not LPA, induced filopodia‐like protrusion formation, which was not mediated by Fyn and ROCK. Thus, Fyn appears to act downstream of LPA and SPC to specifically stimulate stress fiber formation mediated by ROCK in fibroblasts.
Two isoforms of chicken melanopsins show blue light sensitivity
Authors: Torii Masaki , Kojima Daisuke , Okano Toshiyuki , Nakamura Atsushi , Terakita Akihisa , Shichida Yoshinori , Wada Akimori , Fukada Yoshitaka
Published: October 2007

Melanopsin is a vertebrate non‐visual opsin and functions as a circadian photoreceptor in mammalian retinas. Here we found the expression of two kinds of melanopsin genes in the chicken pineal gland and identified the presence of five isoforms derived from these two genes. Reconstitution of the recombinant proteins with 11‐cis‐retinal revealed that at least two of these melanopsin protein isoforms can function as blue‐sensitive photopigments with absorption maxima at 476–484 nm. These values are consistent with maximal sensitivities of action spectra determined from the physiological and behavioral studies on mammalian melanopsins. The melanopsin isoforms found in this study may function as pineal circadian photoreceptors.
Neuronal cell death in the arcuate nucleus of the medulla oblongata in stillbirth
Authors: Folkerth Rebecca D. , Zanoni Sallie , Andiman Sarah E. , Billiards Saraid S.
Published: October 2007

The hypothesis that unexplained stillbirth arises in a similar manner as the sudden infant death syndrome (SIDS) is based in part on shared neuropathologic features between the two entities, including hypoxic‐ischemic lesions such as white matter and brainstem gliosis, as well as aplasia or hypoplasia of the arcuate nucleus on the ventral surface of the medulla. The arcuate nucleus is the putative homologue of the respiratory chemosensory region at the ventral medullary surface in animals that is involved in central chemosensitivity. To determine arcuate nucleus pathology in stillbirth, and its co‐occurrence with evidence of hypoxia‐ischemia, we reviewed brain specimens from the archives of our hospitals from 22 consecutive stillbirths from 22 to 41 gestational weeks. Explained causes of death (n = 17) included nuchal cord, acute chorioamnionitis, placental abruption, and fetal glomerulosclerosis; 5 cases were unexplained. In 12 brains, we observed nuclear karyorrhexis and/or pyknosis with cytoplasmic hypereosinophilia in neurons in the arcuate nucleus in both explained (n = 8) and unexplained (n = 4) cases (54.5% of total cases). Three additional cases had arcuate aplasia (n = 1) or hypoplasia (n = 2) (13.6% of total cases); one of the latter cases also had neuronal necrosis in the hypoplastic arcuate. The degree of gliosis in the region of the arcuate nucleus was variable across all cases, without statistically significant differences between groups with and without arcuate nucleus necrosis. Other lesions in association with (n = 14) and without (n = 8) arcuate nucleus abnormalities were diffuse cerebral white matter gliosis, periventricular leukomalacia (PVL), and neuronal necrosis in the hippocampus, basal ganglia, thalamus, basis pontis, and brainstem tegmentum. In 16/20 (80.0%) cases (with or without histologic necrosis of the arcuate), immunostaining with caspase‐3 demonstrated positive neurons. Our findings suggest that neuronal pathology in the arcuate nucleus may be both developmental (13.6%) and acquired (54.5%). The association of neuronal necrosis and apoptosis in the arcuate nucleus with systemic entities involving fetal ischemia, and with other brain lesions consistent with ischemia, e.g., cerebral white matter gliosis, suggests that ischemia plays a role in the arcuate nucleus damage as well. Thus, the underpopulation of arcuate neurons detected postnatally in some SIDS infants may be secondary to an acquired insult in mid‐ or late gestation, and in other cases, a primary developmental lesion in early gestation, or both. The role of arcuate nucleus pathology in the pathogenesis of fetal demise remains to be determined.
The Democracy-Promotion Gap in American Public Opinion
Authors: TURES JOHN
Published: October 2007

United States foreign-policymakers have enthusiastically backed policies of promoting democracy abroad. But do the American people support these plans? Evidence from polls reveals that while people generally like the idea of exporting freedom, they do not view it as a top priority. Other concepts such as political and economic security are valued more by the American public. Backing for democracy promotion also seems to be waning in recent years. I examine these issues and offer possible reasons for this “gap” in response to democracy promotion among American people. I also explain the implications of these findings for America's foreign policy, including the types of government the US appears to support in the wake of military operations. I conclude with an examination of why the policy of democracy promotion has not been more popular with the American people, evaluating competing arguments that the policy is flawed, as opposed to simply a case of poor public relations.
One Nation under God: Making Historical Sense of Evangelical Protestantism in Contemporary American Politics
Authors: NEWMAN SIMON P.
Published: October 2007

Commentators noted the role of the religious right in the re-election of President George W. Bush in 2004. This essay suggests that such assessments are ahistorical and flawed, and illustrates the ways in which evangelical Protestantism has shaped American political life. Examples of the intersection of religion and politics include Jefferson's election in 1800, John Brown's trial and execution, Abraham Lincoln's Civil War leadership and William Jennings Bryan's radical democratic politics. The essay concludes by arguing that if American-studies teaching and research marginalizes religion it fails to comprehend a vital component of American society and culture.
What's so Funny about Richard Nixon? Vonnegut's Jailbird and the Limits of Comedy
Authors: KAUFMAN WILL
Published: October 2007

This essay explores the questionable potency of satire in the light of Richard Nixon's political rehabilitation. Following a discussion of satirical treatments from the 1940s to the 1980s by, among others, the cartoonists Herbert Block (‘Herblock’) and Garry Trudeau, the comedians Mort Sahl and Lenny Bruce, and writers including Philip Roth and Robert Coover, I examine one work extensively – Kurt Vonnegut's Jailbird (1979) – as a disquisition on satiric impotence, setting that novel in the context of the comedic firepower that had been directed at Nixon since the dawn of his political career and which, in the end, could not prevent his rehabilitation.
Discrepancy between parental reports of infants' receptive vocabulary and infants' behaviour in a preferential looking task
Authors: HOUSTON-PRICE CARMEL , MATHER EMILY , SAKKALOU ELENA
Published: October 2007

Two experiments are described which explore the relationship between parental reports of infants' receptive vocabularies at 1 ; 6 (Experiment 1a) or 1 ; 3, 1 ; 6 and 1 ; 9 (Experiment 1b) and the comprehension infants demonstrated in a preferential looking task. The instrument used was the Oxford CDI, a British English adaptation of the MacArthur-Bates CDI (Words & Gestures). Infants were shown pairs of images of familiar objects, either both name-known or both name-unknown according to their parent's responses on the CDI. At all ages, and on both name-known and name-unknown trials, preference for the target image increased significantly from baseline when infants heard the target's label. This discrepancy suggests that parental report underestimates infants' word knowledge.
Errata and addendum: tensor products and Dunford–Pettis sets
Authors: Ghenciu Ioana , Lewis Paul
Published: October 2007

Ghenciu and Lewis introduced the notion of a strong Dunford–Pettis set and used this notion to study the presence or absence of isomorphic copies of c0 in Banach spaces. The authors asserted that they could obtain a fundamental result of J. Elton without resorting to Ramsey theory. While the stated theorems are correct, unfortunately there is a flaw in the proof of the first theorem in the paper which also affects subsequent corollaries and theorems. The difficulty is discussed, and Elton's results are employed to establish a Schauder basis proposition which leads to a quick proof of the theorem in question. Additional results where questions arise are discussed on an individual basis.
Epidemiologie – alle Jahre wieder?
Authors: Witschi  , Koch
Published: October 2007

Die saisonale Grippe kommt alle Jahre wieder und zeigt ganz verschiedene Gesichter. Neben relativ harmlosen Grippeerkrankungen fallen ihr jedes Jahr viele vor allem ältere Menschen zum Opfer. Trotz intensiver Überwachung der Aktivität und der Virenzirkulation auf nationaler und internationaler Ebene kennt man die Faktoren, welche die Ausbreitung der Grippe begünstigen, nicht genau. Im Hinblick auf eine drohende Pandemie werden sowohl die Grundlagenforschung als auch die Überwachung der Grippe intensiviert, damit neue Erkenntnisse gewonnen werden können. In diesem Artikel wird neben dem Einblick in die Grippe-Überwachungssysteme von Deutschland, Österreich und der Schweiz auch die Sterblichkeitsüberwachung in der Schweiz kurz dargestellt.
Patients with Congestive Heart Failure and Healthy Controls Differ in Vitamin D-Associated Lifestyle Factors
Authors: Zittermann  , Fischer  , Schleithoff  , Tenderich  , Fuchs  , Koerfer
Published: October 2007

We have recently hypothesized that low vitamin D status may contribute to the pathogenesis of congestive heart failure (CHF). This study was aimed at evaluating, in a pilot study, whether CHF patients have indications for a low vitamin D status during earlier periods of their lives. We performed a case-controlled study in 150 CHF patients and 150 controls. Study participants had to answer a questionnaire that included several items concerning vitamin D-associated lifestyle factors during childhood, adolescence, and adulthood. A vitamin D score was constructed. This score takes into consideration that ultraviolet-B (UVB) exposure is the major vitamin D source for humans and that those lifestyle factors, which are associated with regular UVB exposure, can guarantee an adequate vitamin D status at best. The vitamin D score was significantly higher in controls than in patients (p < 0.001). Compared with the controls, more patients lived in large cities (p < 0.001), fewer patients were members of a sport club (p < 0.001), and fewer patients had summer holidays every year (p < 0.01). Patients also reported significantly less alcohol consumption during adulthood than controls (p < 0.001). Our results demonstrate that CHF patients and controls differed in several vitamin D-associated lifestyle factors and in alcohol consumption during earlier periods of their lives.
Moderne Aspekte der klinischen Autopsie
Authors: Diebold
Published: October 2007

Anfang des 21. Jahrhunderts wird das Fach Pathologie zunehmend geprägt durch die Einführung neuer molekularpathologischer Techniken. Es entwickelt sich zu einer klinischen Disziplin an der Schnittstelle von Diagnose und Therapie. Die klinische Autopsie erscheint vielen Ärztinnen und Ärzten daher als überholt. Die Autopsie ist jedoch gerade durch die Verfügbarkeit der molekularen Techniken zu einer überaus aussagekräftigen Methode weiterentwickelt worden («Molekulare Autopsie»). Auch in Zukunft werden Obduktionen ein zentrales Instrument der Qualitätssicherung, der Aus-, Fort- und Weiterbildung, der Epidemiologie (z.B. Krebsregister) und der Forschung (z.B. neurodegenerativer Krankheiten) darstellen. Mit einer Bejahung der Autopsie zeigen Ärztinnen und Ärzte darüber hinaus, dass sie zur Selbstkritik fähig sind und ihren Beruf interdisziplinär verstehen. Da Autopsien häufig Befunde ans Tageslicht fördern, die für das Leben anderer Patienten oder für die Verwandten der Verstorbenen von entscheidender Bedeutung sein können, dokumentieren Angehörige mit ihrem Ja zur Autopsie in bestem Sinne Mitmenschlichkeit.
Die rechtsmedizinischeAutopsie
Authors: Hauri
Published: October 2007

Die moderne klinische Autopsie dient der Lehre, Forschung und Qualitätssicherung. Sie ist in gewissem Sinne Gegenstand der Beziehung zwischen Arzt und Patient aber auch des kollegialen Diskurses zwischen behandelnden Ärzten und Pathologen. Die rechtsmedizinische Autopsie ist demgegenüber ein behördliches Mittel zur Klärung rechtlicher Sachverhalte. Sie wird daher amtlich angeordnet und durchgesetzt. Der behandelnde Arzt kann keine rechtsmedizinische Autopsie in Auftrag geben; er ist jedoch zur Meldung nicht sicher als natürlich zu erkennender Todesfälle (aussergewöhnliche Todesfälle) an die Strafverfolgungsbehörde verpflichtet. Die Fragestellungen und insbesondere die Techniken der klinischen und der rechtsmedizinischen Autopsie unterscheiden sich zum Teil erheblich, weshalb die eine die andere auf keinen Fall ersetzen kann.
Die klinische Autopsie aus der Sicht des Gesundheitspolitikers
Authors: Dürr
Published: October 2007

Die Autopsie – als Lektion des Todes – sollte integraler Bestandteil unseres Gesundheitswesens sein. Neben ihren Funktionen in der Aus-, Weiter- und Fortbildung wie für die Familienberatung, hat die Autopsie vom gesundheitspolitischen Standpunkt aus vor allem ihre Bedeutung hinsichtlich der Qualitätssicherung und Krankheits- wie Todesursachenstatistiken. Zudem zwingt die Systematik der DRG (diagnosis related groups) letztlich zur Erhöhung der Frequenz klinischer Autopsien als endgültiger Qualitätsparameter, da so der Gefahr einer im Wesentlichen ökonomisch ausgerichteten Minimalmedizin mit möglichst eingeschränkter Diagnostik und einfacher Therapie entgegengewirkt werden kann. Eine breite diesbezügliche Aufklärung in Ärzteschaft und Bevölkerung sowie Gesundheitspolitik erscheint dringlich.
Connections between deep tropical clouds and the Earth's ionosphere
Authors: Hagan M. E. , Maute A. , Roble R. G. , Richmond A. D. , Immel T. J. , England S. L.
Published: October 2007

We report on a series of simulations with the National Center for Atmospheric Research (NCAR) thermosphere‐ionosphere‐mesosphere‐electrodynamics general circulation model (TIME‐GCM) which were designed to replicate and facilitate the interpretation of the longitudinal structure discovered in IMAGE satellite airglow observations of the equatorial ionization anomaly (EIA) at the far‐ultraviolet (FUV) 135.6‐nm wavelength during March–April 2002 equinox. Our TIME‐GCM results indicate that the four‐peaked longitudinal variation in the EIA observed by IMAGE‐FUV near 20:00 local solar time can be explained by the effects of an eastward propagating zonal wavenumber‐3 diurnal tide (DE3) that is excited by latent heat release associated with raindrop formation in the tropical troposphere.
Ionospheric depletion in auroral downward currents
Authors: Cran‐McGreehin Alexandra P. , Wright Andrew N. , Hood Alan W.
Published: October 2007

The auroral downward field‐aligned current is mainly carried by electrons of ionospheric origin accelerated into the magnetosphere along the Earth's high‐latitude field lines. The ionosphere is a finite source of electrons: Thus, if a current is to continue to flow, it is natural to assume that the current region must broaden to access more current carriers. In this paper, we present an Alfvén wave model of magnetosphere‐ionosphere interaction to describe the evolution of ionospheric E region number density under the influence of a downward current. The behavior of the system falls into two regimes depending upon whether the quantity = j0/αene2h is greater or less than unity (where j0 is initial current density, α is the recombination coefficient, ne is background E region number density, and h is E region height): If the current density is smaller than a critical current density, jc = αene2h (i.e., < 1), then the E region only depletes within the original current region, and there is sufficient photoionization to feed the current to the magnetosphere; if the required current density is larger than jc (i.e., > 1), then the current region is forced to broaden in order to access sufficient electrons. On the dayside, where a typical E region number density is ∼1011 m−3, broadening only occurs for very strong current densities ∼10 μA m−2; on the nightside, however, where E region number densities can fall by a factor of 10, broadening occurs for any current density greater than ∼0.1 μA m−2. From this model, we derive expressions for the final depletion width (generally ∼1–10 times the width of the original current region) and for the characteristic timescale of depletion (typically ∼10–100 s).
Architecture and mechanics of an active low‐angle normal fault: Alto Tiberina Fault, northern Apennines, Italy
Authors: Chiaraluce L. , Chiarabba C. , Collettini C. , Piccinini D. , Cocco M.
Published: October 2007

We present seismological evidence for the existence of an actively slipping low‐angle normal fault (15° dip) located in the northern Apennines of Italy. During a temporary seismic experiment, we recorded ∼2000 earthquakes with ML ≥ 3.1. The microseismicity defines a 500 to 1000 m thick fault zone that crosscuts the upper crust from 4 km down to 16 km depth. The fault coincides with the geometry and location of the Alto Tiberina Fault (ATF) as derived from geological observations and interpretation of depth‐converted seismic reflection profiles. In the ATF hanging wall the seismicity distribution highlights minor synthetic and antithetic normal faults (4–5 km long) that sole into the detachment. The ATF‐related seismicity shows a nearly constant rate of earthquake production, ∼3 events per day (ML ≤ 2.3), and a higher b value (1.06) with respect to the fault hanging wall (0.85) which is characterized by a higher rate of seismicity. In the ATF zone we also observe the presence of clusters of earthquakes occurring with relatively short time delays and rupturing the same fault patch. To explain movements on the ATF, oriented at high angles (∼75°) to the maximum vertical principal stress, we suggest an interpretative model in which crustal extension along the fault is mostly accommodated by aseismic slip in velocity strengthening areas while microearthquakes occur in velocity weakening patches. We propose that these short‐lived frictional instabilities are triggered by fluid overpressures related to the buildup of CO2‐rich fluids as documented by boreholes in the footwall of the ATF.
Intrinsic optical bistability of thin films of linear molecular aggregates: The one-exciton approximation
Authors: Klugkist Joost A. , Malyshev Victor A. , Knoester Jasper
Published: October 2007

We perform a theoretical study of the nonlinear optical response of an ultrathin film consisting of oriented linear aggregates. A single aggregate is described by a Frenkel exciton Hamiltonian with uncorrelated on-site disorder. The exciton wave functions and energies are found exactly by numerically diagonalizing the Hamiltonian. The principal restriction we impose is that only the optical transitions between the ground state and optically dominant states of the one-exciton manifold are considered, whereas transitions to other states, including those of higher exciton manifolds, are neglected. The optical dynamics of the system is treated within the framework of truncated optical Maxwell-Bloch equations, in which the electric polarization is calculated by using a joint distribution of the transition frequency and the transition dipole moment of the optically dominant states. This function contains all the statistical information about these two quantities that govern the optical response and is obtained numerically by sampling many disorder realizations. We derive a steady-state equation that establishes a relationship between the output and input intensities of the electric field and show that within a certain range of the parameter space this equation exhibits a three-valued solution for the output field. A time-domain analysis is employed to investigate the stability of different branches of the three-valued solutions and to get insight into switching times. We discuss the possibility to experimentally verify the bistable behavior.
A molecular dynamics simulation study on polymer networks of end-linked flexible or rigid chains
Authors: Hosono Nobuhiko , Masubuchi Yuichi , Furukawa Hidemitsu , Watanabe Toshiyuki
Published: October 2007

The differences in formation and structural properties of polymer networks consisting of end-linked flexible or rigid chains were studied by molecular dynamics simulation. Networks were formed from monodisperse, linear, short, flexible or rigid chains with functional end groups and a stoichiometric ratio of trifunctional cross-linkers. The rigid chains had a rodlike shape defined by an angle potential, while the flexible chains had no angle potential. In order to understand the influence of chain rigidity, all parameters of precursor chains (length, reactivity, bond potential, nonbonding potential) were the same, with the exception of the angle potential. The system density ρ, corresponding to the concentration of monomer in solvent, was varied from 0.01 to 0.11. Different network structures resulting from the different processes of network formation were observed. Simulations showed that the flexible chains created an inhomogeneous network on a large scale via microgel cluster formation, in agreement with experimental observations, whereas the rigid chains rapidly created a homogeneous network in the entire system volume without first generating microgel clusters, with the additional difference that they gave rise to mutually interpenetrating networks at the local scale.
Transmitting light efficiently on photonic crystal surface waveguide bend
Authors: Khoo E. H. , Cheng T. H. , Liu A. Q. , Li J. , Pinjala D.
Published: October 2007

In this letter, the transmission efficiency around waveguide bend on the surface of photonic crystal is investigated. Light is confined to the photonic crystal-air interface by means of surface modes. The transmission efficiency around surface waveguide bend is shown to be very poor. This is due to the phase mismatch of the wave vectors between different sections of the surface waveguide bend. To reduce the phase mismatch between the different waveguide sections, the cell properties at the bend section are modified. As a result, high transmission efficiency of more than 93% around the modified surface waveguide bend structure is achieved.
Onset of shadowing-dominated growth in glancing angle deposition
Authors: Amassian Aram , Kaminska Kate , Suzuki Motofumi , Martinu Ludvik , Robbie Kevin
Published: October 2007

We demonstrate that shadowing instabilities can dramatically alter the very early stages of growth of amorphous thin films on nominally smooth surfaces. These observations are made by comparing the porosity and morphological evolutions of thin films grown under conditions of normal and glancing incidences of the vapor flux. At conditions of normal incidence, we see evidence of nucleation, followed by coalescence and growth of a continuous film; at glancing incidence, we observe the development of a mounded surface morphology before deposition of the first nanometer, followed by growth of isolated nanopillars.
Corrected Article: “ac response of a carbon chain under a finite frequency bias” [J. Chem. Phys. 127, 104701 (2007)]
Authors: Yu Yunjin , Wang Bin , Wei Yadong
Published: October 2007

Based on nonequilibrium Green’s function approach and density functional theory, we report first principles investigation on ac transport of four carbon atomic chain connected by two semi-infinite aluminum leads, Al–C4–Al. For small alternating external bias voltage, we expanded nonequilibrium Green’s function to the first order in the external voltage and calculated the dynamical conductance. The suppression of the dynamic conductance was obtained near the resonant level, while far away from the resonance, the large enhancement of the dynamic conductance was observed. These behaviors can be understood well under the wide-band limit. By changing the coupling distance between the carbon atom and the aluminum leads, the system could change its transport response between capacitivelike and inductivelike.
Transient and end silicide phase formation in thin film Ni/polycrystalline-Si reactions for fully silicided gate applications
Authors: Kittl J. A. , Pawlak M. A. , Torregiani C. , Lauwers A. , Demeurisse C. , Vrancken C. , Absil P. P. , Biesemans S. , Coia C. , Detavernier C. , Jordan-Sweet J. , Lavoie C.
Published: October 2007

The Ni/polycrystalline-Si thin film reaction was monitored by in situ x-ray diffraction during ramp annealings, obtaining a detailed view of the formation and evolution of silicide phases in stacks of interest for fully silicided gate applications. Samples consisted of Ni (30–170nm)/polycrystalline-Si (100nm)∕SiO2 (10–30nm) stacks deposited on (100) Si. The dominant end phase (after full silicidation) was found to be well controlled by the deposited Ni to polycrystalline-Si thickness ratio (tNi∕tSi), with formation of NiSi2 (∼600°C), NiSi (∼400°C), Ni3Si2 (∼500°C), Ni2Si, Ni31Si12 (∼420°C), and Ni3Si (∼600°C) in stacks with tNi∕tSi of 0.3, 0.6, 0.9, 1.2, 1.4, and 1.7, respectively. NiSi and Ni31Si12 were observed to precede formation of NiSi2 and Ni3Si, respectively, as expected for the phase sequence conventionally reported. Formation of Ni2Si was observed at early stages of the reaction. These studies revealed, in addition, the formation of transient phases that appeared and disappeared in narrow temperature ranges, competing with formation of the phases expected in the conventional phase sequence. These included the transient formation of NiSi and Ni31Si12 in stacks in which these phases are not expected to form (e.g., tNi∕tSi of 1.7 and 0.9, respectively), at temperatures similar to those in which these phases normally grow.
Chemically induced cracking in a nonstoichiometric oxide
Authors: Jin Z.-H.
Published: October 2007

This work investigates cracking induced by lattice expansion in a plate of a nonstoichiometric oxide in the framework of chemo-elasticity and fracture mechanics. A center crack is considered when the oxide strip is subjected to the fully relaxed conditions, and an edge crack at the cathode side is studied when the oxide is under the constrained flat conditions. Chemical stress intensity factors (CSIFs) are calculated using an integral transform/integral equation method. Numerical results show that crack propagation may be initiated in the oxide as the CSIF may reach the fracture toughness of the material. The oxide strip is most likely to undergo damage in the central part if it is simply supported at the ends, whereas the strip may experience cracking at the cathode side if it is constrained to remain flat but can extend/contract laterally at its ends. The edge crack in a strip under the constrained flat conditions is more prone to propagate because the normalized CSIF is more than 10 times larger than that for the center crack in a strip under the fully relaxed conditions.
Statistical mechanical theory of an oscillating isolated system: The relaxation to equilibrium
Authors: Pérez-Madrid A.
Published: October 2007

In this Contribution we show that a suitably defined nonequilibrium entropy of an N-body isolated system is not a constant of the motion, in general, and its variation is bounded, the bounds determined by the thermodynamic entropy, i.e., the equilibrium entropy. We define the nonequilibrium entropy as a convex functional of the set of n-particle reduced distribution functions (n⩽N) generalizing the Gibbs fine-grained entropy formula. Additionally, as a consequence of our microscopic analysis we find that this nonequilibrium entropy behaves as a free entropic oscillator. In the approach to the equilibrium regime, we find relaxation equations of the Fokker-Planck type, particularly for the one-particle distribution function.