bluuebunny/crossref_metadata_2025 huggingface dataset:
Transmit/receive radiofrequency coil with individually shielded elements
Authors: Gilbert Kyle M. , Curtis Andrew T. , Gati Joseph S. , Martyn Klassen L. , Villemaire Lauren E. , Menon Ravi S.
Published: July 2010

A novel method for decoupling coil elements of transmit/receive (transceive) arrays is reported. Each element of a coil array is shielded both concentrically and radially to reduce the magnetic flux linkage between neighboring coils; this substantially reduces the mutual inductance between coil elements and allows them to behave independently. A six‐channel transceive coil was developed using this decoupling scheme and compared with two conventional decoupling schemes: the partial overlapping of adjacent elements and capacitive decoupling. The radiofrequency coils were designed to image the human head and were tested on a 7‐T Varian scanner. The decoupling, transmit uniformity, transmit efficiency, signal‐to‐noise ratio, and geometry factors were compared between coils. The individually shielded coil achieved higher minimum isolation between elements (2.7–4.0 dB) and lower geometry factors (2–14%) than the overlapped and capacitively decoupled coils, while showing a reduction in transmit efficiency (2.8–5.9 dB) and signal‐to‐noise ratio (up to 34%). No difference was found in the power absorbed by the sample during a 90° radiofrequency pulse. The inset distance of coil elements within their shields was then reduced, resulting in significant improvement of the transmit efficiency (1.3 dB) and signal‐to‐noise ratio (28%). The greatest asset of this decoupling method lies in its versatility: transceive coils can be created with elements of arbitrary shape, size, location, and resonant frequency to produce three‐dimensional conformal arrays. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Ein Knochenjob für die Biomimetik
Authors: Fratzl Peter
Published: July 2010

Die Struktur‐Funktions‐Analyse eines Knochens zeigt, wie sein hierarchischer Aufbau zu Biegefestigkeit und Rissbeständigkeit führt. Bioinspirierte Forschung erfordert moderne physikalisch‐chemische Methoden und Chemiker, welche die Erkenntnisse aus der Natur in Materialien umsetzen.
Die Struktur‐ und Bioassaydatenbank PubChem
Authors: Ihlenfeldt Wolf‐D.
Published: July 2010

Bioassays und zugehörige Strukturen sind in der freien Datenbank PubChem zu finden. Forscher liefern ihre Ergebnisse in dieses öffentliche Projekt und greifen auf die Resultate anderer zu.
Totalsynthese des Telomerase‐Inhibitors UCS1025A
Authors: Rüping. Magnus
Published: July 2010

Ob “sanfte” Enolisierung‐Cyclisierung, Oxa‐Michael‐Lactonisierung/Digerier‐Verfahren oder organokatalytische Diels‐Alder‐Reaktion – der einfache Zugang zu größeren Mengen des Telomerase‐Inhibitors ( )‐UCS1025A und Analoga ist gefunden und der Weg zu Struktur‐Wirkungs‐Studien frei.
Isotopenanalyse – ein neues Werkzeug in der Umweltanalytik
Authors: Schmidt Torsten C. , Jochmann Maik A. , Blessing Michaela
Published: July 2010

Die substanzspezifische Isotopenanalytik ist vor allem aus zwei Bereichen bekannt: aus der Authentizitätskontrolle in der Lebensmittelüberwachung und aus der Dopinganalytik im Sport. Weniger bekannt sind die Anwendungen aus der Umweltanalytik – etwa bei der Altlastensanierung an Industriestandorten.
Bereit für Reach?
Authors: Koch Karl Heinz
Published: July 2010

Bei der Umsetzung der neuen Chemikalienverordnung ist die Analytik gefordert, wenn es darum geht, Stoffmengen zu bestimmen oder die Einhaltung von Grenzwerten zu überwachen.
Starker Job trotz schwacher Note
Authors: Osterath Brigitte
Published: July 2010

“Für eine Eins hat es nicht gereicht” , sagt der Chemieprofessor nach der Prüfung. Ist die gefürchtete Zwei wirklich so schlecht? Und gibt es eine Karriere nach der Note “gut”?
Familienbewusste Chemieindustrie
Authors: Rabe Christiane
Published: July 2010

Die Vereinbarkeit von Beruf und Familie zu fördern, ist inzwischen auch für Unternehmen der Chemiebranche erstrebenswert geworden. Familienfreundliche Strukturen machen einen Arbeitgeber attraktiv für potenzielle neue Mitarbeiter.
Anorganische Festkörperchemie im Konzert der Materialforschung
Authors: Jansen Martin
Published: July 2010

Viele Chemiker träumen davon, neue Materialien mit spezifikationsgerechten Eigenschaften herzustellen – Begriffe wie “Maßschneidern” oder “Design” haben Hochkonjunktur. In Wirklichkeit ist die Synthese von neuen Festkörpern aber mit vielen Unwägbarkeiten behaftet. Gelänge es, den Bestand existenzfähiger Stoffe zu katalogisieren, ließe sich im Dialog “Synthese‐Anwendung” die Entdeckung neuer Materialien stark befördern.
Die Last des Kohlenstoffs
Authors: Guggolz Ernst
Published: July 2010

Da sitzen die Regierungsvertreter in Nairobi und beschließen “nichts, was die Erde vor immer mehr Kohlenstoff bewahren würde”. Nicht nur die Erde, auch die Zeitschriftenredaktionen erwiesen sich so im vergangenen Jahr als Schnelle Brüter. Ein Trendbericht.
Iminooxadiazindione: vom Nebenprodukt zur Leitstruktur
Authors: Richter Frank
Published: July 2010

Die vor etwa zehn Jahren begonnene Erforschung des Reaktionsverhaltens von Hexahydrotoluylendiisocyanat hatte ein unerwartetes Ergebnis: Die polycyclischen Iminooxadiazindione waren entdeckt. Dabei gewonnene Erkenntnisse führten zu einer neuen Klasse von Härtern für die Lackindustrie.
Nanostrukturen erstrahlen in neuem Licht
Authors: Hartschuh Achim
Published: July 2010

Eine laserbeleuchtete Metallspitze verstärkt die optischen Signale einzelner Nanostrukturen. So belichtet, lassen sich Raman‐ und Photolumineszenzbilder mit einer Ortsauflösung von 10 nm simultan aufnehmen.
Informationen über die Wasserqualität
Authors: Vogel Eva , Aichert Albert
Published: July 2010

Der chemische Sauerstoffbedarf von Oberflächenwasser, Trinkwasser und Abwasser aus Industrie oder Privathaushalten gibt an, wie viel oxidierbares organisches Material sie enthalten. Dieser Wert wird über Rücktitration bestimmt, die auch vollautomatisch möglich ist.
Habilitationen, weibliche Professoren und Juniorprofessoren
Authors: Schmitz Karin
Published: July 2010

Zum zweiten Mal nach 2004 wurden Ende vergangenen Jahres die Dekanate der Chemiefakultäten nach Anzahl und Fachrichtung der Habilitanden und Juniorprofessuren, der abgeschlossenen Habilitationen und der Zahl der weiblichen C3‐ und C4‐Professoren gefragt. Die GDCh dankt allen Ansprechpartnern an den Hochschulen, die die Daten ihrer Fakultäten zur Verfügung gestellt haben.
Der erweiterte Nutzen von Chemikalienschutzanzügen
Authors: Bulmahn Maren
Published: July 2010

Schutzanzüge bewahren ihr Inneres vor Schaden. Bestimmte Farben und Materialien unterstützen zusätzlich ihre Träger in ihrem Wohlbefinden: Türkis macht Mut, Grün vermittelt Ruhe, Braun vertreibt Stress und Rot erhöht das Selbstbewusstsein.
Nach dem Urknall die ersten Projekte
Authors: Bengs Holger
Published: July 2010

Die Senior Expert Chemists treffen sich regelmäßig. Nach dem ersten Kennenlernen folgen die ersten Projekte. Kommunikationsstrukturen und Expertendatenbank stehen vor der Realisierung.
Der Europäische Forschungsrat: eine Chance ohnegleichen
Authors: Freund Hans‐Joachim
Published: July 2010

Der Europäische Forschungsrat fördert beim 7. Forschungsrahmenprogramm Grundlagenforschung nur aufgrund ihrer wissenschaftlichen Qualität. Themen aus der Chemie sind mehrfach vertreten und Chemiker sollten diese Chance nutzen.
Patente: Statistik und Recherche
Authors: Ellmer Reinhold
Published: July 2010

Wie es mit der chemischen Industrie in puncto Patentanmeldungen bestellt ist, erfährt man auf den Internetseiten des Deutschen Patent‐ und Markenamtes.
Beim Frauenanteil Schlusslicht in Europa
Authors: Bulmahn Maren
Published: July 2010

Die Gleichberechtigung ist in vielen Programmen und Satzungen festgeschrieben. Jetzt kommt es darauf an, in Forschung und Wissenschaft die richtigen Steuerungsinstrumente zu nutzen und geschlechterspezifische Aspekte als Chance und Auftrag zu erkennen.
Der Weg zu sauberen Massenspektren
Authors: Kraus Alexander , McIlwrick Rod , Jung Gisela
Published: July 2010

Mit der richtigen Säulenbehandlung lassen sich bei der Kopplung von LC mit der Massenspektrometrie Geisterpeaks vermeiden.
Attachment–style Differences in the Appraisal of the Attachment Figure
Authors: Dewitte Marieke , De Houwer Jan
Published: July 2010

The present study investigated the distinctive effects of global and specific attachment styles on the processing of attachment–figure cues, focusing specifically on the role of cognitive inhibition. We manipulated the temporal accessibility of specific attachment styles and measured automatic inhibitory processes using a negative affective priming (NAP) task presenting positive and negative words. We also measured one's explicit attitude towards the attachment figure. Results showed that specific, but not global, attachment styles influenced the processing of attachment–figure cues. We also found that participants primed with a secure attachment style showed a better inhibition of negative traits than those primed with an insecure style. At the explicit level, the anxious attachment types showed a more negative evaluation of their attachment figure than primed secures. Copyright © 2010 John Wiley & Sons, Ltd.
Gene Flow by Selective Emigration as a Possible Cause for Personality Differences between Small Islands and Mainland Populations
Authors: Ciani Andrea Camperio , Capiluppi Claudio
Published: July 2010

Whether personality differences exist between populations is a controversial question. Even though such differences can be measured, it is still not clear whether they are due to individual phenotypic responses to the environment or whether they have a genetic influence. In a population survey we compared the personality traits of inhabitants of an Italian archipelago (the three Egadi islands; N = 622) with those of the closest mainland population (Trapani area; N = 106) and we found that personality differences between small populations can be detected. Islanders scored significantly lower on the personality traits of openness to experience and extraversion and higher on conscientiousness. We suggest that these personality trait differences could be an adaptive response to a confined socio–environmental niche, genetically produced by a strong, non–random gene flow in the last 20–25 generations, rather than the flexible response of islanders to environmental variables. To test this hypothesis, we compared subsets of the islander population classified by ancestry, birthplace, immigration and emigration and found that differences in extraversion can be accounted for by gene flow, while openness to experience and conscientiousness can also be accounted for by some gene–environment interactions. We propose a Personality Gene Flow hypothesis suggesting that, in small isolated communities, whenever there is strong, non–random emigration, paired with weak and random immigration, we can expect rapid genetic personality change within the population. Copyright © 2010 John Wiley & Sons, Ltd.
Correlation of urinary excretion of sodium with severity of sleep‐disordered breathing in children: A preliminary study
Authors: Kaditis Athanasios G. , Alexopoulos Emmanouel I. , Evangelopoulos Konstantinos , Kostadima Eleni , Varlami Vasiliki , Boultadakis Evangelos , Liakos Nikolaos , Zakynthinos Epameinondas , Zintzaras Elias , Gourgoulianis Konstantinos
Published: July 2010

Background

Nocturnal urinary sodium excretion is related to blood pressure (BP) levels. Elevated BP and increased nocturnal natriuresis have been demonstrated in adults with sleep apnea. Although evidence indicates increased BP in children with obstructive sleep‐disordered breathing (SDB), it is unknown whether these children have also enhanced urinary sodium excretion.

Objective

To evaluate the effects of SDB and morning BP on urinary sodium excretion.

Methods

Consecutive children with snoring (n = 95) underwent polysomnography and morning BP measurement. Fractional excretion of sodium (FENa) was the primary outcome measure and was calculated using sodium and creatinine concentrations in early morning serum and urine specimens.

Results

Subjects with moderate‐to‐severe SDB had similar log‐transformed FENa to that of children with mild SDB and higher than children with primary snoring: −0.13 ± 0.53 versus −0.28 ± 0.41 versus −0.61 ± 0.65 (P = 0.657 and P = 0.003). Obstructive apnea–hypopnea index was significantly related to FENa after adjustment for age, gender and body mass index z‐score (P = 0.002). Children with moderate‐to‐severe SDB had similar systolic BP z‐scores to those of subjects with mild SDB and higher than participants with primary snoring: 0.7 ± 1.2 versus 0.1 ± 1.0 versus −0.02 ± 1.0 (P = 0.074 and P = 0.046). In addition, participants with diastolic BP z‐scores in the upper quartile of measured values had higher FENa than subjects with z‐scores in the lower quartiles: −0.08 ± 0.39 versus −0.41 ± 0.57 (P = 0.007).

Conclusions

Morning natriuresis is related to severity of SDB in children and this association may be mediated in part by elevated BP. Pediatr Pulmonol. 2010; 45:999–1004. © 2010 Wiley‐Liss, Inc.
Clinical characteristics of Korean pediatric patients critically ill with influenza A (H1N1) virus
Authors: Shin Soo Youn , Kim Joon Hyung , Kim Hyun Su , Kang Young A , Lee Ha Gyung , Kim Jin Seok , Lee Jong‐Koo , Kim Woo Kyung
Published: July 2010

Background

Novel influenza A (H1N1) virus infection has persisted mainly through person‐to‐person transmission in schools. However, data on critically ill patients infected with H1N1 are currently limited. This study was conducted to investigate the epidemiological characteristics, clinical features, treatment modalities, and clinical outcomes of pediatric patients critically ill with H1N1 infection.

Methods

Subjects included 30 critically ill pediatric patients reported to the Korea Centers for Disease Control and Prevention (KCDC) between June and November 2009. Data were obtained by medical record review and interviews with primary treating physician.

Results

Of the 30 patients, 14 died and 16 were discharged from the hospital with complete recovery. The median patient age was 7 years (range, 2 months to 18 years). Nineteen patients belonged to the high‐risk group. Cough was the most common initial symptom, followed by fever. In most patients, serum levels of C‐reactive protein and lactate dehydrogenase were elevated. Oseltamivir, an antiviral agent, was administered to 29 patients. The most common causes of death were encephalopathy and myocarditis, with a higher mortality rate in the high‐risk group. Platelet counts were significantly lower than normal and serum aspartate aminotransferase levels significantly higher in the non‐survivors.

Conclusions

The results of this study suggest that Korean high‐risk pediatric patients have an elevated mortality rate following infection with novel influenza A (H1N1) virus. Further studies involving high‐risk pediatric patients classified using consistent criteria are needed to confirm our results. Pediatr Pulmonol. 2010; 45:1014–1020. © 2010 Wiley‐Liss, Inc.
Vaccination and risk assessment for children travelling abroad
Authors: Gawthrop Mary , Ford Lisa
Published: July 2010

Our series Prescribing in children gives practical advice for the management of childhood problems in general practice. Here, the authors discuss the provision of travel vaccines for children going abroad. Copyright © 2010 Wiley Interface Ltd
Bistable defects in low‐energy electron irradiated n‐type 4H‐SiC
Authors: Beyer F. C. , Hemmingsson C. G. , Pedersen H. , Henry A. , Isoya J. , Morishita N. , Ohshima T. , Janzén E.
Published: July 2010

Epitaxial n‐type 4H‐SiC layers were irradiated at room temperature by low‐energy electrons. During the annihilation process of the irradiation induced defects EH1 and EH3, three new bistable centers, labeled EB centers, were detected in the DLTS spectrum. The reconfigurations of the EB centers (I → II and II → I) take place at room temperature with a thermal reconfiguration energy of about 0.95 eV. The threshold energy for moving the Si atom from its site in the SiC crystal structure is higher than the applied irradiation energy; therefore, the EB centers are attributed to carbon related complex defects. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Chloride‐based CVD of 3C‐SiC epitaxial layers on 6H(0001) SiC
Authors: Leone Stefano , Beyer Franziska C. , Henry Anne , Kordina Olof , Janzén Erik
Published: July 2010

The heteroepitaxial growth of 3C‐SiC on 6H‐SiC(0001) on‐axis substrates is demonstrated in this study. A hot‐wall CVD reactor working at a reduced pressure was used to perform growth experiments at temperatures between 1300 °C and 1500 °C. The addition of hydrogen chloride to standard precursors allowed a wide window of operating parameters, which resulted in the growth of very high quality and purity 3C‐SiC layers, with a morphology characterized largely by single‐domains, especially when nitrogen was intentionally added. Growth rate of 10 µm/h and n‐type background doping in the low 1015 cm–3 range were achieved. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sparse graphs: Metrics and random models
Authors: Bollobás Béla , Riordan Oliver
Published: July 2010

Recently, Bollobás, Janson and Riordan introduced a family of random graph models producing inhomogeneous graphs with n vertices and Θ(n) edges whose distribution is characterized by a kernel, i.e., a symmetric measurable function κ: [0, 1]2 → [0, ∞). To understand these models, we should like to know when different kernels κ give rise to “similar” graphs, and, given a real‐world network, how “similar” is it to a typical graph G(n, κ) derived from a given kernel κ.

The analogous questions for dense graphs, with Θ(n2) edges, are answered by recent results of Borgs, Chayes, Lovász, Sós, Szegedy and Vesztergombi, who showed that several natural metrics on graphs are equivalent, and moreover that any sequence of graphs converges in each metric to a graphon, i.e., a kernel taking values in [0, 1].

Possible generalizations of these results to graphs with o(n2) but ω(n) edges are discussed in a companion article [Bollobás and Riordan, London Math Soc Lecture Note Series 365 (2009), 211–287]; here we focus only on graphs with Θ(n) edges, which turn out to be much harder to handle. Many new phenomena occur, and there are a host of plausible metrics to consider; many of these metrics suggest new random graph models and vice versa. © 2010 Wiley Periodicals, Inc. Random Struct. Alg., 39, 1‐38, 2011
Electronic and optical properties of La‐aluminate dielectric thin films on Si (100)
Authors: Tahir Dahlang , Choi Eun Hye , Cho Young Joon , Oh Suhk Kun , Kang Hee Jae , Jin Hua , Heo Sung , Chung Jae Gwan , Lee Jae Cheol , Tougaard Sven
Published: July 2010

Electronic and optical properties of (La2O3)x(Al2O3)1−x thin films grown on Si(100) by the atomic layer deposition method were studied by means of reflection electron energy loss spectroscopy (REELS). The dielectric function ε(k, ω), index of refraction (n) and the extinction coefficient (k) for (La2O3)x(Al2O3)1−x thin films were obtained from a quantitative analysis of REELS data. The band gap of (La2O3)x(Al2O3)1−x thin films increases from 5.75 to 6.35 eV as the Al2O3 content (1 − x) increases from 0.5 to 0.75 in the compound. The optical properties described in terms of n, k, and ε of (La2O3)x(Al2O3)1−x were obtained from REELS spectra by using QUEELS‐ε(k, ω)‐REELS software. They show that the electronic and optical properties of (La2O3)x(Al2O3)1−x thin films are dominated by La2O3 even for high Al2O3 concentrations. Copyright © 2010 John Wiley & Sons, Ltd.
TOF‐SIMS studies of intercalated Gibbsite and Bayerite
Authors: Nguyen Chuong L. , Perander Linus M. , Hyland Margaret M. , Metson James B.
Published: July 2010

Surface studies of the oxides and hydroxides of aluminum by TOF‐SIMS have raised the question of the origin of large fragment ions observed in these spectra at masses well beyond 2000 Daltons. The larger fragment ions, especially in the negative secondary ion spectra, are simple net singly charged (based on stoichiometry) combinations of Al, O and OH.

To investigate the origin of these fragments, the layered aluminum hydroxide Gibbsite has been modified to induce changes in interlayer bonding. A base‐hydrolyzed solution of FeCl3 was used to induce intercalation between the Al/O octahedral layers of the Gibbsite structure and the effects of modification were examined in the TOF‐SIMS spectra. The spectra of Fe‐modified Gibbsite are dominated by two major families of (Al2O3)xOH− and (Al2O3)xAlO2− fragments, while those of the unmodified material exhibit additional intermediate fragments attributed to the sampling of multiple octahedral layers. The intercalation of Fe2O3 also causes morphological and structural changes to the Gibbsite particles. Similar modification of another layered aluminum hydroxide, Bayerite, grown on metal surfaces, also removes these intermediate groups, but introduces new iron‐based families of repeating fragments. These studies indicate the repeating fragments observed in the SIMS spectra are sensitive to modification of interlayer bonding in these structures. Copyright © 2010 John Wiley & Sons, Ltd.
Investigation of a connector electrical failure
Authors: Arrowsmith Peter , Kapadia Prakash , Hawley Al , Sodhi Rana
Published: July 2010

A PC product built by Celestica experienced a high rate of functional failure. Failure was associated with the CPU and CPU connector (known as a zero insertion force, ZIF type) since mechanically flexing the CPU stack induced failure. This problem became particularly serious when the customer adopted an uncontrolled (manual) “press” test, resulting in a large amount of rejected product which may have been functional under normal operating conditions.

A failure analysis method involving static loading the CPU and epoxy potting the connector stack was developed to mechanically “trap” the fail condition. Sectioning and electrical probing was used to determine which of the 240 active connector pins have high resistance.

Analysis of suspect connector pins and contact surfaces pointed to several possible causes of failure. SEM‐EDX revealed localized damage to the Au plating with exposed Ni and NiO. XPS and TOF‐SIMS with depth profiling confirmed the presence of a ∼100 nm layer of a fluorocarbon on the Au surface. Although it was not possible to clearly locate the individual electrical contact spots (1–10 µm diameter) to identify localized contamination, the presence of a probable insulating coating was sufficient evidence to follow‐up with the connector supplier. The connector spring contacts were found to be coated with an “anti‐flux” agent to prevent wicking of liquid solder onto contact surfaces during the wave solder assembly process. The corrective action was to change the ZIF connector to a type without anti‐flux coating and the failure rate was significantly reduced. Copyright © 2010 John Wiley & Sons, Ltd.
Composition optimization and UV‐annealing dependence on the electrical properties of Hf1−xSixO2/Si gate stacks
Authors: He G. , Zhang L. D. , Liu M. , Fang Q
Published: July 2010

Hf1−xSixO2 gate dielectrics grown by UV‐photo‐induced chemical vapor deposition (UV‐CVD) using Hf(OBut)2(mmp)2 and tetraethoxysilane as precursors have been deposited on Si substrate. Composition dependence of the interfacial microstructure of the Hf1−xSixO2/Si gate stacks has been investigated via Fourier transform infrared spectroscopy (FTIR) systematically. It has been indicated that the physical properties of the Hf1−xSixO2 films can be effectively optimized by adjusting the silicon contents incorporated in the films. In order to evaluate its potential implementation as an alternative dielectric in future devices, detailed electrical characterization of Au/Hf1−xSixO2/Si capacitor has been performed as functions of the silicon contents and the UV‐annealing time. Copyright © 2010 John Wiley & Sons, Ltd.
IP address assignment in wireless mesh networks
Authors: Zimmermann Alexander , Hannemann Arnd , Schleinzer Benjamin
Published: July 2010

In recent years cheap Internet access has become increasingly popular within the industrialized countries. Especially in the age of Web 2.0, where popular Internet applications begin to dominate computer use, ubiquitous network access is more important than ever. A new class of networks aim to satisfy the demand for high bandwidth, low‐cost, and ubiquitous Internet access: wireless mesh networks (WMNs). However, in order to reach a greater market penetration a fundamental factor must yet to be addressed: the ease of use. Except for small networks, manual configuration is infeasible, so robust autoconfiguration mechanisms are needed. To address this shortcoming of complicated setup procedures we introduce and evaluate a novel autoconfiguration protocol for WMN: the Dynamic WMN Configuration Protocol (DWCP). It deals with the assignment of unique addresses, the management of free and assigned addresses, the autonomous reaction to failures, and features support of conventional Dynamic Host Configuration Protocol (DHCP) clients. It is specifically suitable for large installations and was deployed and evaluated in a real testbed. Copyright © 2010 John Wiley & Sons, Ltd.
Role of the nuclear envelope in genome organization and gene expression
Authors: Van de Vosse David W. , Wan Yakun , Wozniak Richard W. , Aitchison John D.
Published: July 2010

Although often depicted as a static structure upon which proteinaceous factors bind to control gene expression, the genome is actually highly mobile and capable of exploring the complex domain architecture of the nucleus, which in turn controls genome maintenance and gene expression. Numerous genes relocate from the nuclear periphery to the nuclear interior upon activation and are hypothesized to interact with pre‐assembled sites of transcription. In contrast to the nuclear interior, the nuclear periphery is widely regarded as transcriptionally silent. This is reflected by the preferential association of heterochromatin with the nuclear envelope (NE). However, some activated genes are recruited to the nuclear periphery through interactions with nuclear pore complexes (NPCs), and NPC components are capable of preventing the spread of silent chromatin into adjacent regions of active chromatin, leading to the speculation that NPCs may facilitate the transition of chromatin between transcriptional states. Thus, the NE might better be considered as a discontinuous platform that promotes both gene activation and repression. As such, it is perhaps not surprising that many disease states are frequently associated with alterations in the NE. Here, we review the effects of the NE and its constituents on chromatin organization and gene expression. WIREs Syst Biol Med 2011 3 147–166 DOI: 10.1002/wsbm.101

This article is categorized under:

Biological Mechanisms > Regulatory Biology
Building mentoring relationships
Authors: Hamilton Stephen F. , Hamilton Mary Agnes
Published: July 2010

This article is the first of three brief commentaries on this volume. The authors are highly influential pioneers in the study of youth mentoring relationships, and their contributions helped shape the focus of the conceptual framework featured in the opening article by Karcher and Nakkula. Their commentary sheds light on the history of key issues presented in this volume, including the origins of their early work on instrumentality—goal‐focused orientation—and relationship building in youth mentoring, and links those efforts to the contributions presented in this special issue.
Culture, context, and innovation: A Kiwi Canuck perspective
Authors: Marshall Dave , Shaver Karen
Published: July 2010

This commentary lends a global practitioner perspective on the utility of this volume to the efforts of mentors and mentees and mentoring program developers. Dave Marshall and Karen Shaver, of Big Brothers Big Sisters New Zealand and Canada, respectively, offer keen insights into the value of creating a shared language for discussing mentoring relationship development, while at the same time acknowledging the specific impact that cultural differences play in helping to shape mentoring processes.
Effect of feed type and sex on digestibility and feed efficiency utilization in black spiny‐tailed iguana (Ctenosaura pectinata)
Authors: Rueda‐Zozaya P. , Mendoza G.D. , Crosby M.M. , González G. , Reynoso V.H.
Published: July 2010

Digestibility, feed efficiency, and the effect of sex were evaluated in black iguanas (Ctenosaura pectinata) using two commercial pellets (rabbit and chicken). The experiment was performed in 80 iguanas in a completely randomized design with a factorial arrangement 2×2 over 105 days. No differences were detected by food type in weight gain (chicken vs. rabbit: 121 vs. 154 mg/d) and daily intake (chicken vs. rabbit: 524 vs. 551 mg/d), but differences were detected (P<0.05) in feed conversion (chicken vs. rabbit: 6.45 vs. 4.47). Rabbit pellets showed higher digestibility than chicken food (P<0.01) in dry matter (59.8 vs. 41.4%) and NDF (55.4 vs. 43.6%), respectively. Sex had no effect in any of the variable responses. Black iguanas can be raised since 6 months old in captivity with commercial food designed for rabbit or broiler. No special physiological adaptations occur in black iguanas correlated with change in feeding habits during ontogeny. Zoo Biol 30:349–354, 2011. © 2010 Wiley‐Liss, Inc.
Influence of aphid–host plant pairs on the survivorship and development of the multicolored Asian ladybird beetle: implications for the management of vegetation in rural landscapes
Authors: Kamo Tsunashi , Tokuoka Yoshinori , Miyazaki Masahisa
Published: July 2010

Although the value of noncrop vegetation for biological control has been extensively studied in agricultural landscapes, there are few reports on how it functions mechanistically. When focusing on the pest control function provided by noncrop vegetation, tritrophic interactions among a predatory natural enemy, its prey, and the prey's host plant need to be examined. In Japan, the multicolored Asian ladybird beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), an aphidophage, serves as a natural pest control agent in agricultural production, although the species’ introduction into Europe and North America for pest control has had a negative impact on native ecosystems. In the present study, 33 aphid–plant pairs from an agricultural landscape in the eastern Kanto region of Japan were examined experimentally for initial larval survivorship and development of H. axyridis. Significant differences were found among plant–aphid pairs with regard to these parameters. In addition, the larval survivorship of H. axyridis was not consistently determined by host plant or aphid species alone but was context‐dependently influenced by the aphid–plant combination. Some alien host plants showed positive effects on the ladybird beetle. Others, however, served as hosts for unsuitable prey species, such as the competitive alien plants Solidago canadensis L. and Robinia pseudoacacia L., which are the host plants of Uroleucon nigrotuberculatum (Olive) and Aphis craccivora Koch, respectively. These findings suggest that various noncrop plants could be managed to promote ladybird beetle populations in rural landscapes.
A simple method to predict pretracheal tissue thickness to prevent accidental decannulation in the obese
Authors: Szeto Christopher , Kost Karen , Hanley James A. , Roy Ann , Christou Nicholas
Published: July 2010

OBJECTIVE

Accidental decannulation is the most common and serious complication associated with tracheostomy in obese patients. We lack a simple way to choose appropriate‐size tracheostomy tubes in this patient subset. Our purpose was to 1) establish the range of trachea‐to‐skin soft tissue thickness (TTSSTT) in obese patients and 2) determine which easily obtained anthropometric measurements are most predictive of TTSSTT.

STUDY DESIGN

Case series with planned data collection.

SETTING

Tertiary care center.

SUBJECTS AND METHODS

Forty consenting patients with body mass index ranging from 30 to 70 were evaluated. These patients, from a bariatric clinic, underwent ultrasound (US) of the neck in predetermined sitting, supine, and neck‐extended positions (as for tracheostomy). US was performed by a qualified radiologist. Standard anthropometric measurements of weight, height, arm, hip, waist, and neck sizes were performed. Multiple regression analysis was used to determine which anthropometric measurements best correlated with TTSSTT.

RESULTS

The TTSSTT, as measured by US in the supine position, ranged from 0.65 to 3.53 cm. Although the anthropometric measurement most predictive of TTSSTT was waist circumference, a combination of the more practical arm and neck circumferences resulted in an equivalent correlation (r = 0.82). The average root mean squared error was 0.4 cm. From the fitted regression equation, a table predicting TTSSTT from neck and arm circumference was prepared.

CONCLUSION

TTSSTT can be closely predicted using simple anthropometric tape measures. The predicted TTSSTT can be used to select appropriate tracheostomy tube size in obese patients. Use of this simple tool is expected to significantly reduce the incidence of accidental decannulation in obese patients.

© 2010 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved.
Noise exposure and convertible cars
Authors: Michael Philip , Opie Neil , Smith Michael
Published: July 2010

OBJECTIVE

To investigate whether drivers of convertible cars are exposed to excessive noise levels.

STUDY DESIGN

Prospective.

SETTING

Data were collected along a main United Kingdom highway.

SUBJECTS AND METHODS

Seven cars were included within the study, encompassing a range in cost, power, and comfort. A calibrated, integrating noise meter was used to measure average noise levels (Leq dB) and peak levels (Lmax dB) encountered in the region of the driver's roadside ear with the convertible roof lowered. Readings were recorded at speeds of 50, 60, and 70 mph with the windows lowered and also at 70 mph with the windows raised.

RESULTS

Noise levels for all testing conditions had a range for Leq of 82 dB to 92 dB, whereas the maximum Lmax level noted for articulated lorries was 99 dB.

CONCLUSION

A minimal trend toward increasing noise levels with speed was noted for the speeds tested. A statistically significant difference in noise reduction was found by raising the car windows. Although average levels were noted to be above the 85 dB criterion level legislated by some organizations, the length and frequency of most car journeys with the convertible roof lowered is unlikely to significantly increase the noise exposure risk of most individuals. Future studies may be able to evaluate whether a temporary threshold shift phenomenon may occur.

© 2010 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved.
Correlating voice handicap index and quantitative videostroboscopy following injection laryngoplasty for unilateral vocal paralysis
Authors: Lau David Pang Cheng , Zhang Edward Zhiyong , Wong Seng Mun , Lee Gwyneth , Chan Yiong Huak
Published: July 2010

OBJECTIVE

1) Determine the correlation between voice handicap index and quantitative videostroboscopy for patients undergoing injection laryngoplasty for unilateral vocal paralysis; 2) assess which videostroboscopy measurements correlate best with voice handicap index in patients demonstrating progressive improvement beyond six months following injection laryngoplasty.

STUDY DESIGN

Case series with chart review.

SETTING

Patients undergoing outpatient injection laryngoplasty with hyaluronic acid between 2005 and 2007.

SUBJECTS AND METHODS

Twenty‐eight patients were assessed preoperatively and postoperatively using voice handicap index and videostroboscopy. Various videostroboscopy measurements were quantified: glottic open area (ratio of open to total glottic area during closed phase of phonation), glottic closed phase (frame ratio of closed phase to total glottic cycle), supraglottic compression (percent encroachment of supraglottis onto best‐fit ellipse around glottis), wave amplitude (difference in glottic open area between open and closed phases), and wave duration (number of frames per glottic cycle). Correlation coefficients were calculated using Spearman's r.

RESULTS

One hundred seventeen separate recordings were analyzed. Correlation coefficients between voice handicap index (normalized to preoperative values) and glottic closed phase showed moderate‐strong correlation (r = −0.733, P = 0.001), while glottic open area and wave duration showed weak‐moderate correlation (r = 0.465, P < 0.001 and r = −0.404, P < 0.001 respectively). Other parameters showed poor correlation. A subset of 25 recordings from eight patients with progressive voice handicap index improvement beyond six months showed highest correlation with supraglottic compression (r = 0.504, P < 0.05).

CONCLUSION

Voice handicap index correlates best with glottic closed phase, suggesting duration of vocal fold closure during the glottic cycle best represents patients’ subjective outcome post‐procedure. Progressive improvement in voice handicap index beyond six months may relate to gradual reduction in compensatory supraglottic compression, with moderate correlation.

© 2010 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved.
Die wahre Gesundheit - Einige Anmerkungen zum Thema Laieninformation über Medizin
Authors: Wewetzer Hartmut
Published: July 2010

Einleitung

Die Themen Wissenschaft, Medizin und Gesundheit interessieren viele Leser, wie aus Befragungen immer wieder hervorgeht. Unabhängige und kritische Information ist auf diesem Gebiet eigentlich so unerlässlich wie hilfreich. Trotzdem führt der Medizin- und Wissenschaftsjournalismus nach einem Zwischenhoch mittlerweile ein eher gefährdetes Dasein.
Hypolipidaemic and antioxidative effects of oligonol, a low-molecular-weight polyphenol derived from lychee fruit, on renal damage in type 2 diabetic mice
Authors: Noh Jeong Sook , Kim Hyun Young , Park Chan Hum , Fujii Hajime , Yokozawa Takako
Published: July 2010

Oligonol was orally administered at 10 or 20 mg/kg body weight per d for 8 weeks todb/dbmice with type 2 diabetes, and its effects were compared with those of the vehicle indb/dbandm/m(misty, non-diabetic) mice. Serum and renal biochemical factors, protein expressions related to lipid metabolism and inflammation, and advanced glycation endproducts were measured. There were significant reductions in the serum lipid concentration, reactive oxygen species (ROS) and lipid peroxidation, as well as improvements in renal function parameters. In addition, oligonol treatment significantly decreased ROS levels and lipid peroxidation in the kidney. In particular, the renal lipid contents such as TAG and total cholesterol were significantly reduced in the oligonol-administered groups through the up-regulation of PPARα and down-regulation of sterol regulatory element-binding protein-1 indb/dbmice. Moreover, oligonol inhibited non-fluorescent AGE formation and their receptor expression, suggesting that it could effectively inhibit AGE development caused by oxidative stress and/or dyslipidaemia in the kidney ofdb/dbmice. Furthermore, augmented expressions of NF-κBp65, cyclo-oxygenase-2 and inducible NO synthase were down-regulated to the levels ofm/mmice in the group given oligonol at 20 mg/kg. This means that oligonol would act as a regulator in the inflammatory response of type 2 diabetes. The present results suggest that oligonol could have renoprotective effects against abnormal lipid metabolism and ROS-related AGE formation in type 2 diabetes.
From 2008 to 2010: Big-Ticket Spectacles in China and India
Authors: Aiyar Pallavi
Published: July 2010

The hoopla, the sparkling “new clothes” for the host city, the chest-thumping sense of nationalism that pervades the event: there is much about Shanghai in 2010 that is reminiscent of Beijing in 2008.
Enveloping semigroups of unipotent affine transformations of the torus
Authors: PIKUŁA RAFAŁ
Published: July 2010

We provide a description of the enveloping semigroup of the affine unipotent transformation T:X→X of the form T(x)=Ax+α, where A is a lower triangular unipotent matrix, α is a constant vector, and X is a finite-dimensional torus. In particular, we show that in this case the enveloping semigroup is a nilpotent group whose nilpotency class is at most the dimension of the underlying torus.
Bowen’s equation in the non-uniform setting
Authors: CLIMENHAGA VAUGHN
Published: July 2010

We show that Bowen’s equation, which characterizes the Hausdorff dimension of certain sets in terms of the topological pressure of an expanding conformal map, applies in greater generality than has been heretofore established. In particular, we consider an arbitrary subset Z of a compact metric space and require only that the lower Lyapunov exponents be positive on Z, together with a tempered contraction condition. Among other things, this allows us to compute the dimension spectrum for Lyapunov exponents for maps with parabolic periodic points, and to relate the Hausdorff dimension to the topological entropy for arbitrary subsets of symbolic space with the appropriate metric.
A full family of multimodal maps on the circle
Authors: MELO WELINGTON DE , SALOMÃO PEDRO A. S. , VARGAS EDSON
Published: July 2010

We exhibit a family of trigonometric polynomials inducing a family of 2m-multimodal maps on the circle which contains all relevant dynamical behavior.
Extension of harmonic cut-off in a waveform controlled laser field by prolonging the recombining period
Authors: Xu Junjie , Yu Yongli , Zeng Bin
Published: July 2010

We present a novel waveform synthesized by a half-cycle fundamental wave (800 nm) and a half-cycle subharmonic wave (2400 nm) with an appropriate carrier-envelope phase and a phase delay, in which more ionized electrons can recombine with its parent ions to emit high-order harmonic, giving rise to both the extension of the extreme ultraviolet supercontinuum and the enhancement of harmonic conversion efficiency. An isolated attosecond pulse with considerable energy is obtained as well. By performing time-frequency analyses, it is revealed that the prolonged opposite electric field increases the recombining probability of high-energy electrons.
A systematic review of outbreak and non-outbreak studies of extraintestinal pathogenicEscherichia colicausing community-acquired infections
Authors: GEORGE D. B. , MANGES A. R.
Published: July 2010

A systematic review of outbreak and non-outbreak studies of infections caused by extraintestinal pathogenicEscherichia coli(ExPEC) was conducted. This review examines the epidemiology, seasonality, source or mode of transmission, and temporal changes, based onE. coliserogroup, in ExPEC causing sporadicvs. outbreak-associated infections. Twelve outbreak and 28 non-outbreak studies were identified. The existence of ExPEC outbreaks was well supported. Three of four outbreak reports indicated peak periods during the winter months. Serogroups associated with outbreak infections ranged from 1% to 26% (average 11·4%)vs. (range 1–15%, average 3·5%) for serogroups associated with sporadic infections; the distribution of serogroups also differed for outbreak and non-outbreak infections. Study authors indicated that the outbreaks may have resulted from foodborne transmission, but direct evidence was unavailable. This review provides evidence that the epidemiology of endemicvs. epidemic ExPEC infections differs; however, study reporting quality limited epidemiological inferences.
Herd contact structure based on shared use of water points and grazing points in the Highlands of Ethiopia
Authors: WARET-SZKUTA A. , ORTIZ-PELAEZ A. , PFEIFFER D. U. , ROGER F. , GUITIAN F. J.
Published: July 2010

The use of shared common water points (WPs) and grazing points (GPs) at two different levels of administrative aggregation (village and kebelle) in a region of the Highlands of Ethiopia was explored by means of a questionnaire survey and social network analysis. Despite GPs being more abundant than WPs (208 and 154, respectively), individual GPs provide more contact opportunities for animals. There was great variability in the contact structure of the selected villages within kebelles for both networks, with this variability being higher in the GP networks for each kebelle. Contrary to the commonly held view that WPs are critical for the potential transmission of infectious diseases, intervention at GPs in the Ethiopian Highlands may have greater impact on contacts and thereby opportunities for transmission of infectious diseases between flocks. Some villages appear naturally at much lower risk of introducing disease. These findings could help the design of surveillance and control activities for directly transmitted infectious diseases.
The clinical assessment of orthostatic hypotension
Authors: Davis Karl R
Published: July 2010

Orthostatic hypotension is a common condition seen in up to one-third of community-dwelling and two-thirds of hospitalized older people. It is part of a spectrum of abnormal cardiovascular responses to postural challenge and is associated with syncope, dizziness, falls, volume depletion, drug side-effects and an increased mortality. This article discusses the current classification of orthostatic hypotension and related conditions, and the clinical importance of the control of the cardiovascular response to orthostasis. These are considered with particular reference to the measurement of postural cardiovascular responses in the routine clinical setting. By improving understanding of the methods that are used for assessment of postural changes in blood pressure, clinicians should have greater confidence in the reliability of measurement and in their interpretation.
Sans,préposition négative d’avec?
Authors: CHOI-JONIN INJOO , MIGNON FRANÇOISE
Published: July 2010

Le présent article a pour but de réexaminer la valeur du motsans, généralement considéré comme préposition négative d’avec. En limitant l'examen des emplois desansaux cas où celui-ci est suivi d'un constituant nominal, nous démontrons (i) que les contextes syntaxiques dans lesquels apparaissentsansetavecsont sensiblement différents, et (ii) que la valeur négative desansne peut pas être assimilée à la négation de la construction enavec. Il est proposé une hypothèse selon laquellesansest un négatif incorporant lenediscordantiel et que le régime nominal desansprésente sémantiquement une structure propositionnelle.
Sensorimotor-Cognitive Couplings in the Context of Assistive Spatial Navigation for Older Adults
Authors: Schellenbach Michael , Lövdén Martin , Verrel Julius , Krüger Antonio , Lindenberger Ulman
Published: July 2010

With advancing adult age, sensorimotor functioning, spatial processing, and the motivation to explore new environments decline, leading to impaired spatial navigation skills. Using a controlled virtual-world laboratory equipped with a treadmill interface, we examined how assistive navigation technologies differing in cognitive demand affect walking regularity and navigation performance in younger and older adults. Relative to an assistive device with low cognitive demands, older, but not younger adults’ navigation performance decreased with a cognitively more demanding device. Furthermore, older adults showed higher gait irregularity than younger adults, especially with the cognitively demanding device. We conclude that assistive navigation devices show promise in supporting older adults’ pedestrian mobility if aging-induced increments in cognitive demands of spatial navigation and postural control are considered.