bluuebunny/crossref_metadata_2025 huggingface dataset:
Die wundervolle Welt aktiver Vielteilchensysteme: Autos, Fußgänger, Vögel oder andere „motorisierte”︁ Teilchen lassen sich durch relativ einfache Verallgemeinerungen der Newtonschen Gleichungen beschreiben
Authors: Helbing Dirk
Published: February 2013

Warum werden Autofahrer oft von „Staus aus dem Nichts”︁ zum Anhalten gezwungen, obwohl jeder schnell vorankommen möchte? Wieso entstehen die meisten Staus, bevor die Straßenkapazität erreicht ist? Können Geschwindigkeitsbegrenzungen den Verkehr beschleunigen? Weshalb organisieren sich entgegengesetzt laufende Fußgänger in Bahnen? Wieso produzieren Fußgänger in Paniksituationen gefährliche Blockadezustände? Wie organisieren sich Vogelschwärme, und was haben sie mit Spin‐Systemen gemeinsam? Gibt es Gemeinsamkeiten zwischen der Dynamik von Verkehr und Aktienmärkten? Das alles sind Probleme, die man dank neuer Einsichten in die Dynamik von aktiven Vielteilchensystemen besser verstehen kann.
Teilchenphysik: Supersymmetrie — der Weg zur großen Vereinheitlichung?: Eine Vielzahl indirekter Hinweise deutet darauf hin, dass Materie und Kräfte vereinheitlicht werden können
Authors: Moortgat‐Pick Gudrid , Zerwas Peter M.
Published: February 2013

Das Standardmodell der Teilchenphysik hat es in den vergangenen Jahren mit großem Erfolg ermöglicht, die Grundstruktur der Materie aufzudecken. Es versagt jedoch, wenn man es zu Energien fortsetzt, bei denen die Vereinigung von elektroschwacher und starker Wechselwirkung erwartet wird. Erst die Einbettung des Standardmodells in eine übergeordnete supersymmetrische Theorie, bei der jedem bekannten Teilchen ein supersymmetrischer Partner zugeordnet wird, erlaubt eine konsistente Vereinigung von elektroschwacher und starker Kraft., Die im Bau bzw. in der Planung befindlichen neuen Teilchenbeschleuniger sollen die Frage beantworten, ob die Supersymmetrie tatsächlich in der Natur realisiert ist.
Science Center – ein neuer Freizeittrend: Kinder und Erwachsene rennen den Mitmachmuseen die Türen ein ‐ Didaktiker streiten über die richtige Form der Inszenierung
Authors: Flegel Ilka
Published: February 2013

Bilden, unterhalten und neugierig machen: die Science Center verfolgen ehrgeizige Ziele. Als interaktive Wissenschaftsausstellungen haben sie sich im angelsächsischen Raum längst etabliert. Auch hierzulande versprechen die neuen „Mitmachmuseen”︁ gute Unterhaltung nebst wissenschaftlichen Aha‐Erlebnissen. Die deutschen Zentren können aus Fehlern der Amerikaner lernen.
Statistische Physik: Langzeitkorrelationen in der Natur: Von Klima, Erbgut und Herzrhythmus: Die Fluktuationsanalyse erlaubt es, Klimamodelle zu testen oder Schlafphasen zu untersuchen
Authors: Bunde Armin , Kantelhardt Jan W.
Published: February 2013

Wichtige Auskünfte über komplexe Systeme in der Natur erhalten wir oft aus Zeitreihen: Aus Temperatur‐ und Niederschlagsreihen erhoffen wir uns Aufschluss über globale Klimaänderungen, und aus medizinischen Zeitreihen wie der des Herzschlags oder des Blutdrucks kann man oft Rückschlüsse auf den Gesundheitszustand des Patienten ziehen. In den letzten Jahren hat sich herausgestellt, dass in einigen wichtigen Zeitreihen die Schwankungen der einzelnen Elemente um ihren Mittelwert nicht voneinander unabhängig sind. Die Schwankungen sind stattdessen über sehr lange Zeitspannen hinweg untereinander gekoppelt, d.h. die zugrunde liegenden Prozesse besitzen ein oft überraschend langes Gedächtnis. Von diesem Phänomen der Langzeitkorrelationen, die gewisse universelle Züge tragen, handelt dieser Artikel.
Max‐Planck‐Medaille: Ein Blick zurück, ein Blick nach vorn
Authors: Fröhlich Jürg
Published: February 2013

“Ein vielgestaltiger Bau ist er, der Tempel der Wissenschaft. Gar verschieden sind die darin wandelnden Menschen und die seelischen Kräfte, welche sie dem Tempel zugeführt haben.”—Albert Einstein
Zitierungszahlen — eine Messlatte zur Bewertung von Forschungsqualität?
Authors: Marx Werner , Schier Hermann
Published: February 2013

Die „Wissenschaft von der Wissenschaft”︁ ist zu einer neuen Fachdisziplin geworden und hat sich unter den Namen „Scientometrie”︁, „Bibliometrie”︁ oder auch „Infometrie”︁ etabliert. Datengrundlage scientometrischer Untersuchungen sind häufig die Zitierungs‐Indexe des amerikanischen „Institute for Scientific Information”︁ (ISI) in Philadelphia. Die Aussagekraft und Brauchbarkeit von Zitierungszahlen als Maß zur Bewertung von Forschungsergebnissen wird inzwischen auch in Deutschland ausgiebig diskutiert. Zitierungszahlen werden mittlerweile vielfach als zusätzlicher Indikator zur Beurteilung von Forschung herangezogen. Die schnelle Entwicklung der Informationstechnik und Neuerungen bei Datenbanken und Informationssystemen haben diese Entwicklung noch verstärkt. Wo liegen die Möglichkeiten und Grenzen dieser Methode? Welche Gefahren gehen mit der Erstellung und Interpretation von Zitierungszahlen einher?
Kompaktionsdynamik granularer Materie: Warum sind Corn‐Flakes Tüten nie ganz voll?
Authors: Linz Stefan J.
Published: February 2013

Beim erstmaligen Öffnen von Corn‐Flakes‐Packungen stellt man mit Erstaunen fest, dass sie eigentlich nicht randvoll, sondern nur zu circa achtzig Prozent gefüllt sind. Als Erklärung wird auf der Packung z. B. die Bemerkung „Füllhöhenschwankungen transportbedingt”︁ offeriert. Was sich physikalisch dahinter verbirgt, nämlich die Kompaktionsdynamik granularer Materie, hat sich in den letzten Jahren zu einem aktuellem Forschungsgebiet der klassischen Vielteilchenphysik entwickelt. In diesem Artikel sollen Grundaspekte, neuere experimentelle Resultate und einfache theoretische Erklärungsansätze des Kompaktionsproblems näher beleuchtet werden.
Energie: Kernfusion als Energiequelle der Zukunft: Der International Thermonuclear Experimental Reactor ITER ist der nächste Schritt auf dem Weg zum Fusionskraftwerk
Authors: Bosch Hans‐Stephan , Bradshaw Alexander
Published: February 2013

In einem Fusionskraftwerk soll Energie — ähnlich dem Prozess in der Sonne — durch die Verschmelzung von leichten Atomkernen gewonnen werden. Von allen möglichen Verschmelzungsreaktionen, die für ein solches Kraftwerk in Frage kämen, liefert die Reaktion zwischen den Wasserstoffisotopen Deuterium und Tritium die größte Energieausbeute bei der niedrigsten Temperatur. Der Fusionsreaktor der Sonne verwendet normalen Wasserstoff, der als heißes Plasma durch die eigene Schwerkraft zusammengehalten wird. Im irdischen Kraftwerk dagegen muss das heiße Brennstoffgemisch in einem Magnetfeldkäfig eingeschlossen und damit von den Wänden des Vakuumgefäßes ferngehalten werden. Die Vorteile der Fusionsenergie sind bekannt: hohe intrinsische Sicherheit, fast grenzenlose Brennstoffvorräte, keine Emissionen und wenig radioaktiver Abfall. Wie weit die Fusionsforschung in den letzten Jahren gekommen ist und wie lange es noch dauert, bis diese Energiequelle den von den Fusionsforschern erwarteten Beitrag zur Grundlast der Stromversorgung liefert, sind die wichtigsten Themen dieses Artikels.
Polymer‐ und Kolloidphysik in der BASF
Authors: Rieger Jens , Iden Rüdiger
Published: February 2013

Shampoos, Plastiktüten, Waschmittel, Vitamine, Klebstreifen, Styropor, Beton, Anstrichfarbe, Meerwasserentsalzung. Diese kleine Aufstellung, die sich fast beliebig fortsetzen ließe, soll einen Eindruck davon vermitteln, womit sich Physiker in der industriellen Polymerforschung beschäftigen. Welche Rolle sie dabei spielen, soll dieser Beitrag zeigen. Dazu muss man auch auf die Philosophie in der industriellen Forschung eingehen, die sich deutlich von der Denkweise an den Universitäten unterscheidet. und schließlich möchten wir noch darauf aufmerksam machen, dass es Fragen gibt, die aus unserer Sicht intensiverer physikalischer Grundlagenforschung bedürfen.
The clathrin adaptor complexes as a paradigm for membrane‐associated allostery
Authors: Canagarajah Bertram J. , Ren Xuefeng , Bonifacino Juan S. , Hurley James H.
Published: February 2013

The clathrin‐associated adaptor protein (AP) complexes AP‐1 and AP‐2 are two members of a family of heterotetrameric assemblies that connect transmembrane protein cargo to vesicular coats. Cargo binding by AP‐1 is activated by the small GTPase Arf1, while AP‐2 is activated by the phosphoinositide PI(4,5)P2. The structures of both AP‐1 and AP‐2 have been determined in their locked and unlocked conformations. The structures show how different activators use different mechanisms to trigger similar large scale conformational rearrangements. The details of these mechanisms show how membrane docking and allosteric activation of AP complexes are intimately connected.
Biodegradable Nanocapsules as siRNA Carriers for Mutant K‐Ras Gene Silencing of Human Pancreatic Carcinoma Cells
Authors: Lin Guimiao , Hu Rui , Law Wing‐Cheung , Chen Chih‐Kuang , Wang Yucheng , Li Chin Hui , Nguyen Quoc Toan , Lai Cheng Kee , Yoon Ho Sup , Wang Xiaomei , Xu Gaixia , Ye Ling , Cheng Chong , Yong Ken‐Tye
Published: February 2013

The application of small interfering RNA (siRNA)‐based RNA interference (RNAi) for cancer gene therapy has attracted great attention. Gene therapy is a promising strategy for cancer treatment because it is relatively non‐invasive and has a higher therapeutic specificity than chemotherapy. However, without the use of safe and efficient carriers, siRNAs cannot effectively penetrate the cell membranes and RNAi is impeded. In this work, cationic poly(lactic acid) (CPLA)‐based degradable nanocapsules (NCs) are utilized as novel carriers of siRNA for effective gene silencing of pancreatic cancer cells. These CPLA‐NCs can readily form nanoplexes with K‐Ras siRNA and over 90% transfection efficiency is achieved using the nanoplexes. Cell viability studies show that the nanoparticles are highly biocompatible and non‐toxic, indicating that CPLA‐NC is a promising potential candidate for gene therapy in a clinical setting.
Trauma‐related Preventable Deaths in Berlin 2010: Need to Change Prehospital Management Strategies and Trauma Management Education
Authors: Kleber C. , Giesecke M. T. , Tsokos M. , Haas N. P. , Buschmann C. T.
Published: February 2013

Background

Fatal trauma is one of the leading causes of death in Western industrialized countries. The aim of the present study was to determine the preventability of traumatic deaths, analyze the medical measures related to preventable deaths, detect management failures, and reveal specific injury patterns in order to avoid traumatic deaths in Berlin.

Materials and methods

In this prospective observational study all autopsied, direct trauma fatalities in Berlin in 2010 were included with systematic data acquisition, including police files, medical records, death certificates, and autopsy records. An interdisciplinary expert board judged the preventability of traumatic death according to the classification of non‐preventable (NP), potentially preventable (PP), and definitively preventable (DP) fatalities.

Results

Of the fatalities recorded, 84.9 % (n = 224) were classified as NP, 9.8 % (n = 26) as PP, and 5.3 % (n = 14) as DP. The incidence of severe traumatic brain injury (sTBI) was significantly lower in PP/DP than in NP, and the incidence of fatal exsanguinations was significantly higher. Most PP and NP deaths occurred in the prehospital setting. Notably, no PP or DP was recorded for fatalities treated by a HEMS crew. Causes of DP deaths consisted of tension pneumothorax, unrecognized trauma, exsanguinations, asphyxia, and occult bleeding with a false negative computed tomography scan.

Conclusions

The trauma mortality in Berlin, compared to worldwide published data, is low. Nevertheless, 15.2 % (n = 40) of traumatic deaths were classified as preventable. Compulsory training in trauma management might further reduce trauma‐related mortality. The main focus should remain on prevention programs, as the majority of the fatalities occurred as a result of non‐survivable injuries.
Kein Kind bleibt zurück
Authors: Stodden David , Holfelder Benjamin
Published: February 2013

Die Förderung von gesundheitsbewusstem Verhalten über die Lebensspanne hinweg ist ein weltweites Problem, das nicht nur Auswirkungen auf die gesamte physische Gesundheit hat (d. h. die Milderung der zunehmenden Rate an Adipositas und der Abnahme an körperlicher Aktivität), sondern auch auf die psychische und kognitive Gesundheit. Eine wachsende Anzahl an Studien zeigt, dass die Entwicklung von motorischen Fertigkeiten ein wichtiger direkter und/oder indirekter Mechanismus sein könnte, um positive physische und psychologische Gesundheitsverläufe in der Kindheit und im Erwachsenenalter zu fördern ( Stodden et al., 2008 ). Jüngste Untersuchungen zeigen außerdem, dass es zwischen körperlicher Aktivität und Adipositas sowie kognitiver Gesundheit und akademischer Leistung einen Zusammenhang gibt. Die direkte Integration der Entwicklung motorischer Fertigkeiten, als ein Schwerpunkt im Rahmen von Interventionen, könnte ebenfalls Aspekte der kognitiven Gesundheit beeinflussen. Aus einer entwicklungsorientierten Perspektive ist es wichtig, physische, psychologische und kognitive Gesundheit im frühen Kindesalter bereits anzusprechen, um positive Verläufe über die Lebensspanne hinweg zu fördern. Dieser Artikel stellt eine Übersicht über aktuelle Daten bezüglich der Zusammenhänge zwischen verschiedenen Aspekten der Entwicklung motorischer Fertigkeiten und körperlicher Aktivität, gesundheitsbezogener Fitness, Adipositas und psychischer Gesundheit dar. Des Weiteren liefert er Begründungen für Wissenschaftler, um den möglichen Einfluss der Entwicklung motorischer Fertigkeiten auf verschiedene Aspekte kognitiver Gesundheit zu untersuchen.
First successful ionization of Lr (Z = 103) by a surface-ionization technique
Authors: Sato Tetsuya K. , Sato Nozomi , Asai Masato , Tsukada Kazuaki , Toyoshima Atsushi , Ooe Kazuhiro , Miyashita Sunao , Schädel Matthias , Kaneya Yusuke , Nagame Yuichiro , Osa Akihiko , Ichikawa Shin-ichi , Stora Thierry , Kratz Jens Volker
Published: February 2013

We have developed a surface ionization ion-source as part of the JAEA-ISOL (Isotope Separator On-Line) setup, which is coupled to a He/CdI2 gas-jet transport system to determine the first ionization potential of the heaviest actinide lawrencium (Lr, Z = 103). The new ion-source is an improved version of the previous source that provided good ionization efficiencies for lanthanides. An additional filament was newly installed to give better control over its operation. We report, here, on the development of the new gas-jet coupled surface ion-source and on the first successful ionization and mass separation of 27-s 256Lr produced in the 249Cf + 11B reaction.
Note: Computer controlled rotation mount for large diameter optics
Authors: Rakonjac Ana , Roberts Kris O. , Deb Amita B. , Kjærgaard Niels
Published: February 2013

We describe the construction of a motorized optical rotation mount with a 40 mm clear aperture. The device is used to remotely control the power of large diameter laser beams for a magneto-optical trap. A piezo-electric ultrasonic motor on a printed circuit board provides rotation with a precision better than 0.03° and allows for a very compact design. The rotation unit is controlled from a computer via serial communication, making integration into most software control platforms straightforward.
Core-ion temperature measurement of the ADITYA tokamak using passive charge exchange neutral particle energy analyzer
Authors: Pandya Santosh P. , Ajay Kumar , Mishra Priyanka , Dhingra Rajani D. , Govindarajan J.
Published: February 2013

Core-ion temperature measurements have been carried out by the energy analysis of passive charge exchange (CX) neutrals escaping out of the ADITYA tokamak plasma (minor radius, a = 25 cm and major radius, R = 75 cm) using a 45° parallel plate electrostatic energy analyzer. The neutral particle analyzer (NPA) uses a gas cell configuration for re-ionizing the CX-neutrals and channel electron multipliers (CEMs) as detectors. Energy calibration of the NPA has been carried out using ion-source and ΔE/E of high-energy channel has been found to be ∼10%. Low signal to noise ratio (SNR) due to VUV reflections on the CEMs was identified during the operation of the NPA with ADITYA plasma discharges. This problem was rectified by upgrading the system by incorporating the additional components and arrangements to suppress VUV radiations and improve its VUV rejection capabilities. The noise rejection capability of the NPA was experimentally confirmed using a standard UV-source and also during the plasma discharges to get an adequate SNR (>30) at the energy channels. Core-ion temperature Ti(0) during flattop of the plasma current has been measured to be up to 150 eV during ohmically heated plasma discharges which is nearly 40% of the average core-electron temperature (typically Te(0) ∼ 400 eV). The present paper describes the principle of tokamak ion temperature measurement, NPA's design, development, and calibration along with the modifications carried out for minimizing the interference of plasma radiations in the CX-spectrum. Performance of the NPA during plasma discharges and experimental results on the measurement of ion-temperature have also been reported here.
Effects of compositional polydispersity on gradient copolymer melts
Authors: Jiang Run , Wang Zheng , Yin Yuhua , Li Baohui , Shi An-Chang
Published: February 2013

The phase behavior of gradient copolymers is studied theoretically using random phase approximation (RPA) and self-consistent field theory (SCFT), focusing on the effects of monomer sequence distribution, or compositional polydispersity, of the polymer chains. The stability of the disordered phase is examined using RPA analysis, whereas the ordered phases of the system are studied using SCFT calculations. It is discovered that the critical domain spacing increases and the disorder-order transition temperature moves to higher values with the increase of the compositional polydispersity. SCFT results reveal that, depending on the value of the degree of segregation, structural change due to the different chain-to-chain monomer sequence distribution is controlled by two different mechanisms.
Generalized shock conditions and the contact discontinuity in the Hall-magnetohydrodynamics model
Authors: Hameiri Eliezer
Published: February 2013

It is shown that shocks and contact discontinuities in the Hall-magnetohydrodynamics (HMHD) model must satisfy solvability conditions that replace some of the familiar Rankine-Hugoniot jump conditions when the latter do not apply due to singular behavior of fluxes of conserved quantities. Some of these conditions depend on the larger topology of the plasma and magnetic field and are not merely “local.” The contact discontinuity which separates two adjoining plasma regions or plasma and vacuum regions is the simplest case where the new jump conditions are applicable and is discussed for a toroidal plasma with sheared magnetic field such as the tokamak, but with no initial mass flow. It is proven that a static discontinuous tokamak-like equilibrium is linearly stable in the HMHD model if it is linearly stable within the ideal magnetohydrodynamics model, provided that the electron pressure depends only on the density, and some other restrictions on the ratio of pressure to density gradients also apply. When the electron pressure does depend on two thermodynamic variables, a sufficient condition for Hall-MHD plasma stability is derived as well.
Lattice strain analysis of silicon fin field-effect transistor structures wrapped by Ge2Sb2Te5 liner stressor
Authors: Ding Yinjie , Cheng Ran , Du Anyan , Yeo Yee-Chia
Published: February 2013

The local strain components in the source/drain (S/D) and channel regions of Si fin field-effect transistor (FinFET) structures wrapped around by a Ge2Sb2Te5 liner stressor were investigated for the first time using nano-beam diffraction. When the Ge2Sb2Te5 (GST) layer changes phase from amorphous to crystalline, it contracts and exerts a large stress on the Si fins. This results in large compressive strain in the S/D region of ⟨1¯10⟩-oriented Si FinFETs of up to −1.15% and −1.57% in the ⟨110⟩ (horizontal) and ⟨001⟩ (vertical) directions, respectively. In the channel region of the FinFETs under the metal gate, the GST contraction results in up to −1.47% and −0.61% compressive strain in the ⟨110⟩ and ⟨001⟩ directions, respectively. In the channel region, the ⟨110⟩ compressive strain is higher at the fin sidewalls and lower near the fin center, while the ⟨001⟩ compressive strain is lower at the sidewalls and higher near the center.
Complete set of elastic, dielectric, and piezoelectric constants of [011]C poled rhombohedral Pb(In0.5Nb0.5)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3:Mn single crystals
Authors: Huo Xiaoqing , Zhang Shujun , Liu Gang , Zhang Rui , Luo Jun , Sahul Raffi , Cao Wenwu , Shrout Thomas R.
Published: February 2013

Mn modified rhombohedral Pb(In0.5Nb0.5)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT:Mn) single crystals poled along [011]C crystallographic direction exhibit a “2R” engineered domain configuration, with macroscopic mm2 symmetry. The complete sets of material constants were determined using combined resonance and ultrasonic methods, and compared to [001]C poled PIN-PMN-PT:Mn crystals. The thickness shear piezoelectric coefficient d15 and electromechanical coupling factor k15 were found to be on the order of ∼3000 pC/N and 0.92, respectively, with longitudinal piezoelectric coefficient d33 and coupling factor k33 being on the order of ∼1050 pC/N and 0.90. Of particular importance is that PIN-PMN-PT:Mn single crystals exhibited high mechanical quality factor Q33 ∼ 1000, comparable to “hard” PZT8 ceramics, which can also be confirmed by the low extrinsic contribution, being ≤2% from the Rayleigh analysis.
Computational investigation of the mechanical and tribological responses of amorphous carbon nanoparticles
Authors: Bucholz Eric W. , Sinnott Susan B.
Published: February 2013

Nanoparticles are a class of materials that have seen increasing use as friction and wear reducers in tribological applications. Amorphous carbon (a-C) films have been the subject of significant scientific and industrial interest for use as solid-state lubricants. Here, we present classical molecular dynamics simulations to investigate the mechanical and tribological responses of a-C nanoparticles that are subjected to external forces between hydrogen-terminated diamond surfaces. Over the range of a-C nanoparticle diameters (2–5 nm) and hydrogenation (0%–50%) considered, the simulations predict a consistent mechanical response where each nanoparticle is highly elastic. The simulations predict that the transition from elastic to plastic response is directly related to an increase in the percentage of carbon-carbon crosslinking within the individual nanoparticles. Contrarily, the simulations also predict that the tribological response is noticeably impacted by changes in diameter and hydrogenation. This is because during friction, hydrogen passivates the unsaturated carbon atoms near the nanoparticle's surface, which prevents interfacial bond formation and allows the nanoparticle to roll within the interface. From these findings, it is demonstrated that a-C nanoparticles are able to provide good tribological performance only when sufficient chemical passivation of the nanoparticles is maintained.
Plant mating system transitions drive the macroevolution of defense strategies
Authors: Campbell Stuart A. , Kessler André
Published: February 2013

Understanding the factors that shape macroevolutionary patterns in functional traits is a central goal of evolutionary biology. Alternative strategies of sexual reproduction (inbreeding vs. outcrossing) have divergent effects on population genetic structure and could thereby broadly influence trait evolution. However, the broader evolutionary consequences of mating system transitions remain poorly understood, with the exception of traits related to reproduction itself (e.g., pollination). Across a phylogeny of 56 wild species of Solanaceae (nightshades), we show here that the repeated, unidirectional transition from ancestral self-incompatibility (obligate outcrossing) to self-compatibility (increased inbreeding) leads to the evolution of an inducible (vs. constitutive) strategy of plant resistance to herbivores. We demonstrate that inducible and constitutive defense strategies represent evolutionary alternatives and that the magnitude of the resulting macroevolutionary tradeoff is dependent on the mating system. Loss of self-incompatibility is also associated with the evolution of increased specificity in induced plant resistance. We conclude that the evolution of sexual reproductive variation may have profound effects on plant–herbivore interactions, suggesting a new hypothesis for the evolution of two primary strategies of plant defense.
Convergence of IRBIT, phosphatidylinositol (4,5) bisphosphate, and WNK/SPAK kinases in regulation of the Na
+
-HCO
3
−
cotransporters family
Authors: Hong Jeong Hee , Yang Dongki , Shcheynikov Nikolay , Ohana Ehud , Shin Dong Min , Muallem Shmuel
Published: February 2013

Fluid and HCO
3
−
secretion is a vital function of secretory epithelia, involving basolateral HCO
3
−
entry through the Na
+
-HCO
3
−
cotransporter (NBC) NBCe1-B, and luminal HCO
3
−
exit mediated by cystic fibrosis transmembrane conductance regulator (CFTR) and solute carrier family 26 (SLC26) Cl
−
/HCO
3
−
exchangers. HCO
3
−
secretion is highly regulated, with the WNK/SPAK kinase pathway setting the resting state and the IRBIT/PP1 pathway setting the stimulated state. However, we know little about the relationships between the WNK/SPAK and IRBIT/PP1 sites in the regulation of the transporters. The first 85 N-terminal amino acids of NBCe1-B function as an autoinhibitory domain. Here we have identified a positively charged module within NBCe1-B(37-65) that is conserved in NBCn1-A and all 20 members of the NBC superfamily except NBCe1-A. This module is required for the interaction and activation of NBCe1-B and NBCn1-A by IRBIT and their regulation by phosphatidylinositol 4,5-bisphosphate (PIP
2
). Activation of the transporters by IRBIT and PIP
2
is nonadditive but complementary. Phosphorylation of Ser65 mediates regulation of NBCe1-B by SPAK, and phosphorylation of Thr49 is required for regulation by IRBIT and SPAK. Sequence searches using the NBCe1-B regulatory module as a template identified a homologous sequence in the CFTR R domain and Slc26a6 sulfat transporter and antisigma factor antagonist (STAS) domain. Accordingly, the R and STAS domains bind IRBIT, and the R domain is required for activation of CFTR by IRBIT. These findings reveal convergence of regulatory modalities in a conserved domain of the NBC that may be present in other HCO
3
−
transporters and thus in the regulation of epithelial fluid and HCO
3
−
secretion.
Survey of Central Line–Associated Bloodstream Infection Prevention Practices across American Burn Association–Certified Adult Burn Units
Authors: Sood Geetika , Heath Doris , Adams Kerri , Radu Charlotte , Bauernfeind Judy , Price Leigh Ann , Zenilman Jonathan
Published: February 2013

Central line–associated bloodstream infections (CLABSIs) have a considerable impact on morbidity, length of stay, and potential mortality. The estimated per-case cost of CLABSIs is $11,000–$56,167, and there is consensus that most are preventable. Publicly reported CLABSI data are also now used as a metric to compare hospitals.

There are published guidelines for the prevention of central line–associated infections, but these practices have not been studied in burn patients. Patients with severe burns pose unique and specific challenges and differ substantially from the typical medical or surgical intensive care unit (ICU) patient. Our objective was to assess CLABSI prevention practices in burn units.

We identified all American Burn Association (ABA)–certified adult burn centers through the ABA website (http://www.ameriburn.org) and contacted nursing leadership of each burn intensive care unit to conduct a telephone survey of CLABSI prevention practices in March 2012. The survey project was approved by the Johns Hopkins institutional review board.

We had 100% survey participation. There was substantial variation among burn units in the number of beds, the mix of patients, and the acuity of patients' illness. Bed size varied from 4 to 38. Eight units stated that their burn unit incorporated a step-down unit or floor-status beds in their bed count. Thirty (58.8%) of the 51 units defined themselves as mixed burn/surgical or trauma units. The percentage of burned patients seen in the burn units varied from 10% to 100%, with 8 (15.4%) of 51 units stating that their census consisted of fewer than 30% burned patients in their burn ICU.
Water Deficit Modulates the Response ofVitis viniferato the Pierce's Disease PathogenXylella fastidiosa
Authors: Choi Hong-Kyu , Iandolino Alberto , da Silva Francisco Goes , Cook Douglas R.
Published: February 2013

Pierce's disease, caused by the bacterium Xylella fastidiosa, is one of the most devastating diseases of cultivated grape, currently restricted to the Americas. To test the long-standing hypothesis that Pierce's disease results from pathogen-induced drought stress, we used the Affymetrix Vitis GeneChip to compare the transcriptional response of Vitis vinifera to Xylella infection, water deficit, or a combination of the two stresses. The results reveal a redirection of gene transcription involving 822 genes with a minimum twofold change (P < 0.05), including the upregulation of transcripts for phenylpropanoid and flavonoid biosynthesis, pathogenesis-related proteins, abscisic acid- and jasmonic acid-responsive biosynthesis, and downregulation of transcripts related to photosynthesis, growth, and nutrition. Although the transcriptional response of plants to Xylella infection was largely distinct from the response of healthy plants to water stress, we find that 138 of the pathogen-induced genes exhibited a significantly stronger transcriptional response when plants were simultaneously exposed to infection and drought stress, suggesting a strong interaction between disease and water deficit. This interaction between drought stress and disease was mirrored in planta at the physiological level for aspects of water relations and photosynthesis and in terms of the severity of disease symptoms and the extent of pathogen colonization, providing a molecular correlate of the classical concept of the disease triangle in which environment impacts disease severity.
Angular deficits in flat space: remotely controllable apertures in nematic solid sheets
Authors: Modes C. D. , Warner M. , Sánchez-Somolinos C. , de Haan L. T. , Broer D.
Published: February 2013

Recent attention has been given to the realization of angular deficits and surpluses in the local ground-state geometry of thin sheets of nematic solids as out-of-plane deformations. Such systems exhibit conical or anti-conical curvature sites, or possibly arrays of such polyhedral corners, in order to satisfy the material's spontaneous strain-generated metric requirements. Here, we turn the angular deficit requirement on its head, and show theoretically and experimentally that by appropriately altering the topology of the initially flat sheet—for example, by cutting it in carefully chosen regions—the same angular deficits and surpluses may manifest simply in-plane by changing the geometry of the cut region. Such a mechanism offers a route to apertures or arrays of apertures that may be reversibly opened and closed by applying spontaneous strain with heat, light or chemical potential.
Clathrin Light Chains Regulate Clathrin-Mediated Trafficking, Auxin Signaling, and Development inArabidopsis
Authors: Wang Chao , Yan Xu , Chen Qian , Jiang Nan , Fu Wei , Ma Bojun , Liu Jianzhong , Li Chuanyou , Bednarek Sebastian Y. , Pan Jianwei
Published: February 2013

Plant clathrin-mediated membrane trafficking is involved in many developmental processes as well as in responses to environmental cues. Previous studies have shown that clathrin-mediated endocytosis of the plasma membrane (PM) auxin transporter PIN-FORMED1 is regulated by the extracellular auxin receptor AUXIN BINDING PROTEIN1 (ABP1). However, the mechanisms by which ABP1 and other factors regulate clathrin-mediated trafficking are poorly understood. Here, we applied a genetic strategy and time-resolved imaging to dissect the role of clathrin light chains (CLCs) and ABP1 in auxin regulation of clathrin-mediated trafficking in Arabidopsis thaliana. Auxin was found to differentially regulate the PM and trans-Golgi network/early endosome (TGN/EE) association of CLCs and heavy chains (CHCs) in an ABP1-dependent but TRANSPORT INHIBITOR RESPONSE1/AUXIN-BINDING F-BOX PROTEIN (TIR1/AFB)-independent manner. Loss of CLC2 and CLC3 affected CHC membrane association, decreased both internalization and intracellular trafficking of PM proteins, and impaired auxin-regulated endocytosis. Consistent with these results, basipetal auxin transport, auxin sensitivity and distribution, and root gravitropism were also found to be dramatically altered in clc2 clc3 double mutants, resulting in pleiotropic defects in plant development. These results suggest that CLCs are key regulators in clathrin-mediated trafficking downstream of ABP1-mediated signaling and thus play a critical role in membrane trafficking from the TGN/EE and PM during plant development.
β‐amyloid context intensifies vascular smooth muscle cells induced inflammatory response and de‐differentiation
Authors: Vromman Amélie , Trabelsi Nesrine , Rouxel Clotilde , Béréziat Gilbert , Limon Isabelle , Blaise Régis
Published: February 2013

Several studies have shown that the accumulation of β‐amyloid peptides in the brain parenchyma or vessel wall generates an inflammatory environment. Some even suggest that there is a cause‐and‐effect relationship between inflammation and the development of Alzheimer's disease and/or cerebral amyloid angiopathy (CAA). Here, we studied the ability of wild‐type Aβ1‐40‐peptide (the main amyloid peptide that accumulates in the vessel wall in sporadic forms of CAA) to modulate the phenotypic transition of vascular smooth muscle cells (VSMCs) toward an inflammatory/de‐differentiated state. We found that Aβ1‐40‐peptide alone neither induces an inflammatory response, nor decreases the expression of contractile markers; however, the inflammatory response of VSMCs exposed to Aβ1‐40‐peptide prior to the addition of the pro‐inflammatory cytokine IL‐1β is greatly intensified compared with IL‐1β‐treated VSMCs previously un‐exposed to Aβ1‐40‐peptide. Similar conclusions could be drawn when tracking the decline of contractile markers. Furthermore, we found that the mechanism of this potentiation highly depends on an Aβ1‐40 preactivation of the PI3Kinase and possibly NFκB pathway; indeed, blocking the activation of these pathways during Aβ1‐40‐peptide treatment completely suppressed the observed potentiation. Finally, strengthening the possible in vivo relevance of our findings, we evidenced that endothelial cells exposed to Aβ1‐40‐peptide generate an inflammatory context and have similar effects than the ones described with IL‐1β. These results reinforce the idea that intraparietal amyloid deposits triggering adhesion molecules in endothelial cells, contribute to the transition of VSMCs to an inflammatory/de‐differentiated phenotype. Therefore, we suggest that acute inflammatory episodes may increase vascular alterations and contribute to the ontogenesis of CAA.
Pharmacology of AMG 181, a human anti‐α4β7 antibody that specifically alters trafficking of gut‐homing T cells
Authors: Pan WJ , Hsu H , Rees WA , Lear SP , Lee F , Foltz IN , Rathanaswami P , Manchulenko K , Chan BM , Zhang M , Xia XZ , Patel SK , Prince PJ , Doherty DR , Sheckler CM , Reynhardt KO , Krill CD , Harder BJ , Wisler JA , Brandvig JL , Lynch JL , Anderson AA , Wienkers LC , Borie DC
Published: February 2013

Background and Purpose

AMG 181 is a human anti‐α4β7 antibody currently in phase 1 and 2 trials in subjects with inflammatory bowel diseases. AMG 181 specifically targets the α4β7 integrin heterodimer, blocking its interaction with mucosal addressin cell adhesion molecule‐1 (MAdCAM‐1), the principal ligand that mediates α4β7 T cell gut‐homing.

Experimental Approach

We studied the in vitro pharmacology of AMG 181, and the pharmacokinetics and pharmacodynamics of AMG 181 after single or weekly i.v. or s.c. administration in cynomolgus monkeys for up to 13 weeks.

Key Results

AMG 181 bound to α4β7, but not α4β1 or αEβ7, and potently inhibited α4β7 binding to MAdCAM‐1 (but not vascular cell adhesion molecule‐1) and thus inhibited T cell adhesion. Following single i.v. administration, AMG 181 Cmax was dose proportional from 0.01 to 80 mg·kg−1, while AUC increased more than dose proportionally. Following s.c. administration, dose‐proportional exposure was observed with single dose ranging from 5 to 80 mg·kg−1 and after 13 weekly doses at levels between 20 and 80 mg·kg−1. AMG 181 accumulated two‐ to threefold after 13 weekly 80 mg·kg−1 i.v. or s.c. doses. AMG 181 had an s.c. bioavailability of 80%. The linear elimination half‐life was 12 days, with a volume of distribution close to the intravascular plasma space. The mean trend for the magnitude and duration of AMG 181 exposure, immunogenicity, α4β7 receptor occupancy and elevation in gut‐homing CD4+ central memory T cell count displayed apparent correlations.

Conclusions and Implications

AMG 181 has in vitro pharmacology, and pharmacokinetic/pharmacodynamic and safety characteristics in cynomolgus monkeys that are suitable for further investigation in humans.
Demographic assessment of a stocking experiment in European Eels
Authors: Desprez M. , Crivelli A.J. , Lebel I. , Massez G. , Gimenez O.
Published: February 2013

Since the 1980s, the European eels’ stocks have dramatically decreased with no sign of recovery, resulting in their classification as Critically endangered on the IUCN red list of threatened species. The European Council Regulation 1100/2007 requires that 35% of glass eels caught annually by fishing be released in European waters for restocking. However, the efficiency of this measure on population viability has never been evaluated. Here, we estimated demographic parameters of a stocked population of French eels using a multistate capture–recapture model. Using these estimates, we then estimated population size and predicted the number of future genitors obtained by stocking. We found that the stage in which eels were stocked did not influence their future survival and that the maximal number of silver eels was quickly reached, after 3 years following stocking. We concluded that stocking experiments in the Mediterranean region are efficient for fast production of genitors. We suggest that further studies should assess the quality of these genitors.
Clinical and MRI predictors of response to interferon‐beta and glatiramer acetate in relapsing–remitting multiple sclerosis patients
Authors: Romeo M. , Martinelli‐Boneschi F. , Rodegher M. , Esposito F. , Martinelli V. , Comi G. ,   San Raffaele Multiple Sclerosis Clinical Group
Published: February 2013

Background and purpose

It is still unclear which patients benefit more from available disease‐modifying treatments (DMTs) in multiple sclerosis (MS). Our objective is to identify the baseline clinical and magnetic resonance imaging (MRI) predictors of response to first‐line DMTs in a cohort of relapsing–remitting (RR) MS patients in a real‐world clinical setting.

Methods

Consecutive naïve RRMS patients treated with interferon‐beta or glatiramer acetate have been included and followed for 2 years. Patients were grouped into responders (R) in case of absence of clinical and MRI activity, and non‐responders (NR) if the on‐treatment annualized relapse rate (ARR) reduction was < 50% of the ARR in the 2 years before treatment or in the presence of MRI activity (≥ 2 active lesions at 1‐year MRI or ≥ 4 active lesions at 1 + 2‐year MRI).

Results

At 2‐year follow‐up, 272 patients were R (34.6%) and 322 NR (40.9%), and multivariate analysis revealed that a later age at onset of the disease (P < 0.0001), a lower disability (P < 0.0001) and a lower number of gadolinium‐enhancing lesions at baseline MRI (P = 0.002) were predictors of efficacy of DMTs. Moreover, the first year response had a good predictive power on the second year, as 73.7% of 1‐year R had no evidence of clinical and MRI activity within the ensuing year.

Conclusion

A lower baseline MRI and clinical activity have been identified as predictors of DMT efficacy in patients with RRMS in routine clinical practice. Evaluation of clinical and MRI activity at 1 year is recommended to monitor patients over time.
Sex differences in the effects of chronic stress and food restriction on body weight gain and brain expression of CRF and relaxin‐3 in rats
Authors: Lenglos C. , Mitra A. , Guèvremont G. , Timofeeva E.
Published: February 2013

This study investigated sex‐specific effects of repeated stress and food restriction on food intake, body weight, corticosterone plasma levels and expression of corticotropin‐releasing factor (CRF) in the hypothalamus and relaxin‐3 in the nucleus incertus (NI). The CRF and relaxin‐3 expression is affected by stress, and these neuropeptides produce opposite effects on feeding (anorexigenic and orexigenic, respectively), but sex‐specific regulation of CRF and relaxin‐3 by chronic stress is not fully understood. Male and female rats were fed ad libitum chow (AC) or ad libitum chow and intermittent palatable liquid Ensure without food restriction (ACE), or combined with repeated food restriction (60% chow, 2 days per week; RCE). Half of the rats were submitted to 1‐h restraint stress once a week. In total, seven weekly cycles were applied. The body weight of the RCE stressed male rats significantly decreased, whereas the body weight of the RCE stressed female rats significantly increased compared with the respective control groups. The stressed female RCE rats considerably overate chow during recovery from stress and food restriction. The RCE female rats showed elevated plasma corticosterone levels and low expression of CRF mRNA in the paraventricular hypothalamic nucleus but not in the medial preoptic area. The NI expression of relaxin‐3 mRNA was significantly higher in the stressed RCE female rats compared with other groups. An increase in the expression of orexigenic relaxin‐3 and misbalanced hypothalamic‐pituitary‐adrenal axis activity may contribute to the overeating and increased body weight seen in chronically stressed and repeatedly food‐restricted female rats.
‘The Best Time is Now!’: The Temporal and Spatial Dynamics of Women Opting in to Self‐Employment
Authors: McKie Linda , Biese Ingrid , Jyrkinen Marjut
Published: February 2013

This paper explores the potential for the concepts of time and space, together with the analogy of landscapes, to aid the exploration and understandings of women's careers. Drawing upon case studies of women who chose to opt in to self‐employment, we examine how the multi‐faceted histories of these women are drawn upon as they remember the past, explain contemporary experiences, and anticipate their futures. All the women spoke of opting in to self‐employment as the best of times; they talked of greater control over work content, the relationship between family, gender and paid work, and self‐determinism and autonomy. They noted times when their careers were frayed but only in retrospect could they assess the context, consequences and impact of events. The framework of careerscapes — our unique blending of the notion of careers along with socio‐economic and geographical interpretations of scapes — offers a framework to examine frayed careers and multiple aspects of working and caring over time and space.
Editorial: Frayed Careers: Exploring Rhythms of Working Lives
Authors: Sabelis Ida , Schilling Elisabeth
Published: February 2013

In studies on difference related to age and gender, we face ‘abnormal’ or ‘typical’ work‐life arrangements vis‐à‐vis taken‐for‐granted career concepts. Age and career are conceptualized from different angles depending on politics of work and organization, societal perspectives of age group position, perceived needs to have people work longer, and changing demographics. Underlying all this are questions of how age and gender are constituted in terms of their intersectional, dynamic relationship. We apply a perspective of rhythm to investigate what lies behind the linear life course and career perspectives. The notion of frayed careers serves to highlight rhythm and to criticize linearity and upward direction in views on careers, and at the same time calls for further theory development. In this introduction, we explore the implications of a dynamic‐rhythmic, yet ‘frayed’ perspective on life course, career and gender to represent stages of working life (lives) as interlinked and biographic.
The Effectiveness of Visual Art on Environment in Nursing Home
Authors: Chang Chia‐Hsiu , Lu Ming‐Shih , Lin Tsyr‐En , Chen Chung‐Hey
Published: February 2013

Purpose

This Taiwan study investigated the effect of a visual art–based friendly environment on nursing home residents’ satisfaction with their living environment.

Design

A pre‐experimental design was used. Thirty‐three residents in a nursing home were recruited in a one‐group pre‐ and post‐test study.

Methods

The four‐floor living environment was integrated using visual art, reminiscence, and gardening based on the local culture and history. Each floor was given a different theme, one that was familiar to most of the residents on the floor. The Satisfaction with Living Environment at Nursing Home Scale (SLE‐NHS) was developed to measure outcomes.

Findings

Of the 33 participants recruited, 27 (81.8%) were women and 6 (18.2%) were men. Their mean age was 79.24 ± 7.40 years, and 48.5% were severely dependent in activities of daily living. The SLE‐NHS showed adequate reliability and validity. Its three domains were generated and defined using factor analysis. After the visual art–based intervention, the score on the “recalling old memories” subscale was significantly higher (t = −13.32, p < .001). However, there were no significant score changes on the “convenience” and “pretty and pleasurable” subscales. In general, the participants were satisfied with the redesigned environment and felt happy in the sunny rooms.

Conclusions

Visual art in a nursing home is a novel method for representing the local culture and stressing the spiritual value of the elderly residents who helped create it. Older adults’ aesthetic activities through visual art, including reminiscence and local culture, may enrich their spirits in later life.

Clinical Relevance

Older adults’ aesthetic activities through visual art have been shown to improve their satisfaction with their living environment. The SLE‐NHS is a useful tool for evaluating their satisfaction.