bluuebunny/crossref_metadata_2025 huggingface dataset:
La protection des travailleurs et coopérants étrangers dans les situations de conflit interne, en particulier dans les cas de prises d'otages
Authors: Piernas Carlos Jiménez
Published: April 2010

Il suffit d'un coup d'œil sur la presse quotidienne pour mesurer l'étendue de l'anarchie qui sévit en permanence dans une grande partie de notre planète. Maints Etats sont confrontés à des conflits internes d'origines très diverses, au regard desquels la situation de paix sociale dont jouissent en temps normal l'Amérique du Nord et l'Europe occidentale apparaît comme un rare privilège. Ces situations de conflit interne favorisent l'escalade de la violence la plus arbitraire à rencontre de victimes sans défense et la multiplication des violations des droits et libertés individuels fondamentaux, vis-à-vis tant des autochtones que des étrangers.
Sociétés Nationales de la Croix-Rouge et du Croissant-Rouge: La Croix-Rouge Panaméenne 1917–1992
Authors: Beliz José A.
Published: April 2010

L'origine de la Croix-Rouge remonte à l'époque où Mmc Mathilde Obarrio de Mallet s'aperçut que le développement de la santé était très limité dans notre pays au cours des premières années d'indépendance. Elle entama une série de démarches auprès du gouvernement, de sociétés privées et de personnes généreuses que l'organisation d'une institution d'aide sociale intéressait. Cette initiative aboutit à la fondation de la Croix-Rouge panaméenne, confirmée officiellement par le décret exécutif no 34 du 1er mars 1917.
Travaux récents relatifs à la protection de l'environnement en période de conflit armé
Authors: Bouvier Antoine
Published: April 2010

La problématique de la protection de l'environnement en période de conflit armé a donné lieu à de nombreux débats et suscité d'importants travaux au cours des deux dernières années.

L'intérêt marqué pour cette question nous paraît s'expliquer par au moins deux raisons distinctes. Il fait tout d'abord — et très logiquement — écho aux travaux toujours plus ambitieux visant à améliorer, aux plans national et international, la protection de l'environnement en temps de paix.3 Il répond, par ailleurs, aux craintes nées durant et après le conflit qui a embrasé le Moyen-Orient en 1990–91.
Les Conventions de Genève et les communications télégraphiques
Authors: Pilloud Claude
Published: April 2010

Les prisonniers de guerre, les internés civils et autres victims de la guerre sont autorisés à entretenir avec leur famille une correspondance et à transmettre régulièrement de leurs nouvelles. Le nombre des correspondances expédiées peut être réduit, selon les circonstances, mais le droit à la correspondance a été établi fermement par les Conventions de Genève de 1949.
La réunion des familles en période de conflit armé
Authors: Draper G.I.A.D.
Published: April 2010

La destruction de l'unité et de l'intégrité de la famille, élément naturel et fondamental de la société, selon l'article 16, alinéa 3 de la Déclaration Universelle des Droits de l'Homme de 1948, est l'une des conséquences les plus tragiques des conflits armés. De même, en temps de paix, la menace à l'unité et à l'intégrité de la famille est l'une des formes puissantes et inhumaines de pression que les Gouvernements exercent sur les individus pour enrégimenter leurs peuples. Il est salutaire de rappeler, à cet égard, que l'un des objectifs du droit international est de donner effet, par des restrictions appropriées et une surveillance internationale adéquate sur la souveraineté interne des Etats, au principe selon lequel la protection de la personnalité humaine et des droits fondamentaux de l'homme est le but ultime de toute législation, nationale et internationale. Le droit international n'est pas créé au profit des Etats, mais en dernière analyse au bénéfice des individus qui composent les sociétés politiques. Encore que l'on puisse trouver dans Grotius un tel axiome fondamental quant à l'objet du droit international, sa reconnaissance pratique s'est faite lentement et, même aujourd'hui, n'est que partielle. Le droit international des conflits armés a traité les individus avec sévérité en exposant ceux qui en violent les règles à la juridiction pénale des Etats, au plan universel, et en exposant ceux qui ont été reconnus coupables au risque d'exécution ou de peines sévères.
Les « Mémoires » d'Henry Dunant
Authors: J.-G. L.
Published: April 2010

En décembre 1969, nous présentions id même le premier volume de la « Collection de l'Institut Henry-Dunant » qui contenait Un Souvenir de Solférino et des textes inédits de Dunant groupés sous le titre général de L'Avenir sanglant. Cette collection s'enrichit aujour d'hui d'un nouveau volume intitulé Mémoires, que l'lnstitut Henry-Dunant édite en français, conjointement avec les Editions de l'Age d'homme, à Lausanne. Le texte en a été établi et présenté par le professeur Bernard Gagnebin, doyen de la Faculté des Lettres de l'Université de Genève, qui s'est chargé de faire un choix parmi les manuscrits — 102 cahiers — retrouvés dans trois caisses déposées à la Bibliothèque publique et universitaire de Genève. Besogne aussi difficile que délicate puisque, comme l'écrit lui-même M. Gagnebin dans une substantielle introduction, « les Mémoires d'Henry Dunant ne se présentent nullement comme un texte continu, comme une œuvre achevée. Nous les avons reconstitués en puisant leurs matériaux dans plus de trente cahiers différents et nous les avons subdivisés en trentequatre chapitres ».
Droits de l'homme, droit des conflits armés et représailles
Authors: Kalshoven F.
Published: April 2010

Depuis que la Conférence internationale des droits de l'homme, réunie à Téhéran en avril et mai 1968, a adopté à l'unanimité la Résolution no XXIII sur les droits de l'homme dans les conflits armés, le respect de ces droits a pris un caractère d'actualité qui s'est d'ailleurs intensifié. Mais il n'est pas besoin de connaître profondément la question pour se rendre compte que le problème est, bien entendu, beaucoup plus ancien. On peut dire sans risquer de se tromper que l'idée des droits de l'homme — bien que sous un autre nom peut-être — est à l'origine de toutes les initiatives prises, depuis la Conférence de Bruxelles en 1874, en vue de codifier le droit de la guerre.
Les dommages illicites dans les conflits armés et leur réparation dans le cadre du droit international humanitaire
Authors: Sandoz Yves
Published: April 2010

A côté des aspirations à la paix universelle, des efforts pour limiter les effets de la guerre ont eu lieu de tout temps et dans toutes les grandes civilisations. Mais ces efforts se sont concrétisés avant tout par l'énoncé de préceptes religieux ou moraux et si quelques traités ont bien été conclus, ils étaient de portée limitée.
Le droit international humanitaire et les conflits armés internes internationalisés
Authors: Schindler Dietrich
Published: April 2010

Les conflits armés internes internationalisés se sont multipliés au cours des dernières décennies. Lors de nombreuses guerres civiles, des forces armées étrangères sont intervenues en faveur de l'une ou l'autre partie afin d'influer sur l'issue du conflit. Plusieurs causes sont à l'origine de ce développement. L'une d'elles est l'interdépendance accrue des Etats. De ce fait, chaque guerre civile affecte les autres Etats et, réciproquement, l'attitude des autres Etats peut avoir une incidence sur l'issue de la guerre civile, même sans intervention. Une autre cause c'est la scission idéologique dans le monde, qui divise les nations et entraîne un chevauchement des conflits internes et internationaux. Parmi d'autres causes, on peut mentionner l'existence des blocs militaires et des groupements régionaux, qui ont intérêt à empêcher des renversements de régimes à l'intérieur de leur bloc et tendent à encourager les changements dans d'autres blocs. Il convient de prendre en considération un autre facteur: l'interdiction de l'usage de la force dans les relations internationales. Alors que jadis les Etats se livraient ouvertement la guerre afin d'accroître leur puissance, aujourd'hui, l'usage de la force étant interdit, ils cherchent à parvenir au même résultat en intervenant dans les affaires intérieures d'autres Etats. L'intervention dans les conflits internes se substitue souvent à une guerre internationale. D'ailleurs, l'instabilité de nombreux régimes contemporains, principalement dans le Tiers-Monde, favorise encore l'internationalisation des conflits internes.
Energy dissipation in insulators induced by swift heavy ions: A parameter study
Authors: Osmani O. , Lebius H. , Rethfeld B. , Schleberger M.
Published: April 2010

The irradiation of solids with high energy laser or particle beams has led to a deeper understanding of the relaxation processes inside the target material. However, a lot of open questions remain. In the present paper, we will examine the irradiation of the model system Xe23+ @ 93 MeV → SrTiO3 within the framework of the two-temperature-model and study the electron-phonon-coupling g and the electron diffusivity De as well as the lattice diffusivity Dp. These are crucial parameters for which no experimental data is available. Experimentally, g is very difficult to measure and therefore theoretical predictions are of great importance. With the approach presented here it is possible to determine the coupling-constant by one order of magnitude.
The Katanga Trial Chamber Decision: Selected Issues
Authors: BITTI GILBERT , EL ZEIDY MOHAMED M.
Published: April 2010

The admissibility challenge of the defence in Katanga has raised complex issues of litigation in the light of the practice of self-referrals and existing ICC jurisprudence. This article examines the Katanga Trial Chamber decision and its consequences from this perspective. It focuses on three themes that are of particular relevance, since they have a direct impact on the functioning of the Court and its different organs: (i) the timing for a challenge of the admissibility of the case; (2) access to information related to admissibility; and (iii) the role of the defence.
Nonlinear analysis and synthesis of distributed voltage controlled oscillators
Authors: Collado Ana , Acampora Alessandro , Georgiadis Apostolos
Published: April 2010

A detailed nonlinear analysis and design of a distributed voltage controlled oscillator (DVCO) is presented in this work. The analysis and design of the DVCO is performed using harmonic balance-based simulation techniques and envelope transient simulation. These techniques are used to make a complete nonlinear study of the behavior of the DVCO. Using the proposed nonlinear tools, a DVCO operating in the frequency tuning range between 1 and 2 GHz has been implemented in order to support the simulation results. The average output power and consumption along the frequency band for the designed DVCO are 5.2 dBm and 60.4 mW, respectively.
The policy context of torture: A social-psychoioqical analysis
Authors: Kelman Herbert C.
Published: April 2010

Acts of torture are conceptualized as crimes of obedience, which are inevitably linked to crimes at higher levels of the hierarchy, where orders are issued, policy is formulated, and the atmosphere conducive to acts of torture is created. The present analysis suggests several conditions under which torture becomes an instrument of State policy and the authority structure of the State is fully utilized to implement that policy: the perception by State authorities that the security of the State is under severe threat — which, at the macro-level, can justify torture and, at the micro-level, contribute to its authorization; the existence of an elaborate and powerful apparatus charged with protecting the security of the State — which, at the macro-level, may lead to the recruitment and training of professional torturers as part of that apparatus and, at the micro-level, contribute to the routinization of torture; and the existence of disaffected ethnic, religious, political, or other groups within (or under the control) of the State that do not enjoy full citizenship rights — which, at the macro-level, may lead to their designation as enemies of the State and appropriate targets for torture and, at the micro-level, their dehumanization.
Study on customary international humanitarian law: A contribution to the understanding and respect for the rule of law in armed conflict
Authors: Henckaerts Jean-Marie
Published: April 2010

This article explains the rationale behind a study on customary international humanitarian law recently undertaken by the ICRC at the request of the International Conference of the Red Cross and Red Crescent. It describes the methodology used and how the study was organized and summarizes some major findings. It does not, however, purport to provide a complete overview or analysis of these findings.
Judaism and the ethics of war
Authors: Solomon Norman
Published: April 2010

The article surveys Jewish sources relating to the justification and conduct of war, from the Bible and rabbinic interpretation to recent times, including special problems of the State of Israel. It concludes with the suggestion that there is convergence between contemporary Jewish teaching, modern human rights doctrine and international law.
Precision attack and international humanitarian law
Authors: Schmitt Michael N.
Published: April 2010

This article explores the relationship between precision attack and international humanitarian law. It begins by addressing the nature of precision attack, including precision technologies, the combat environment in which it occurs, attacker tactics, and the targeting process. Modern precision attack's greatest impact on international humanitarian law lies in four areas: indiscriminate attack; proportionality; precautions in attack; perfidy and protected status. The author concludes that precision warfare has both positive and negative implications for the interpretation and application of international humanitarian law on the twenty-first-century battlefield.
Public communication strategies of international humanitarian organizations
Authors: Dijkzeul Dennis , Moke Markus
Published: April 2010

The article studies the public communication strategies of large humanitarian NGOs as well as UN organizations with regard to the humanitarian principles. It shows that different strategies concerning impartiality vs. solidarity and independence vs. subcontracting cause a wide diversity of humanitarian positions, which lead to different types of public communication strategies. It also discusses several recent trends and three scenarios concerning humanitarian public communication, focusing on interaction with donors and the military, as well as the security situation on the ground. The article concludes that it is essential for humanitarian organizations to understand the different interpretations of the humanitarian principles and that this will help in establishing a strategic approach toward public communication at headquarters, as well as in the field.
ICRC communication: Generating support
Authors: Daccord Yves
Published: April 2010

The environment in which the ICRC works and communicates is constantly changing. The ICRC is also constantly seeking support that will allow it to gain access to victims, carry out its work, generate the diplomatic and financial backing needed for that work and ensure the safety of its delegates. The primary aim of communication is not merely to pass on messages from the organization effectively. It is just as necessary to understand the issues concerning the various audiences and how they perceive those issues as it is to inform them. The ICRC draws on a wide array of communication strategies and resources, depending on their complementarity and their potential impact, ranging from meetings with local armed groups to the use of mass communication tools. Communication is thus an integral part of the ICRC's decision-making process, both at headquarters and in each context in the field.
Memory CD8+ T cells from naturally acquired primary dengue virus infection are highly cross‐reactive
Authors: Friberg Heather , Burns Lynne , Woda Marcia , Kalayanarooj Siripen , Endy Timothy P , Stephens Henry AF , Green Sharone , Rothman Alan L , Mathew Anuja
Published: April 2010

Cross‐reactive memory T cells induced by primary infection with one of the four serotypes of dengue virus (DENV) are hypothesized to have an immunopathological function in secondary heterologous DENV infection. To define the T‐cell response to heterologous serotypes, we isolated HLA‐A∗1101‐restricted epitope‐specific CD8+ T‐cell lines from primary DENV‐immune donors. Cell lines exhibited marked cross‐reactivity toward peptide variants representing the four DENV serotypes in tetramer binding and functional assays. Many clones responded similarly to homologous and heterologous serotypes with striking cross‐reactivity between the DENV‐1 and DENV‐3 epitope variants. In vitro‐stimulated T‐cell lines consistently revealed a hierarchical induction of MIP‐1β>degranulation>tumor necrosis factor α (TNFα)>interferon‐γ (IFNγ), which depended on the concentration of agonistic peptide. Phosphoflow assays showed peptide dose‐dependent phosphorylation of ERK1/2, which correlated with cytolysis, degranulation, and induction of TNFα and IFNγ, but not MIP‐1β production. This is the first study to show significant DENV serotype‐cross‐reactivity of CD8+ T cells after naturally acquired primary infection. We also show qualitatively different T‐cell receptor signaling after stimulation with homologous and heterologous peptides. Our data support a model whereby the order of sequential DENV infections influences the immune response to secondary heterologous DENV infection, contributing to varying disease outcomes.
Postprandial oxidative stress is modified by dietary fat: evidence from a human intervention study
Authors: Perez-Martinez Pablo , Garcia-Quintana Jose Maria , Yubero-Serrano Elena M. , Tasset-Cuevas Inmaculada , Tunez Isaac , Garcia-Rios Antonio , Delgado-Lista Javier , Marin Carmen , Perez-Jimenez Francisco , Roche Helen M. , Lopez-Miranda Jose
Published: April 2010

Previous evidence supports the concept that increased oxidative stress may play an important role in MetS (metabolic syndrome)-related manifestations. Dietary fat quality has been proposed to be critical in oxidative stress and the pathogenesis of the MetS. In the present study, we investigated whether oxidative stress parameters are affected by diets with different fat quantity and quality during the postprandial state in subjects with the MetS. Patients were randomly assigned to one of four isoenergetic diets distinct in fat quantity and quality for 12 weeks: a high-saturated-fatty-acid (HSFA) diet, a high-mono-unsaturated-fatty-acid (HMUFA) diet and two low-fat/high-complex carbohydrate diets [supplemented with 1.24 g/day of long-chain n−3 polyunsaturated fatty acid (LFHCC n−3) or with 1 g/day of sunflower oil high in oleic acid (LFHCC) as placebo]. The HMUFA diet enhanced postprandial GSH (reduced glutathione) levels and the GSH/GSSH (oxidized glutathione) ratio, compared with the other three diets. In addition, after the HMUFA-rich diet postprandial lipid peroxide levels, protein carbonyl concentrations, SOD (superoxide dismutase) activity and plasma H2O2 levels were lower compared with subjects adhering to the HSFA-rich diet. Both LFHCC diets had an intermediate effect relative to the HMUFA and HSFA diets. In conclusion, our data support the notion that the HMUFA diet improves postprandial oxidative stress in patients with the MetS. These findings suggest that the postprandial state is important for understanding the possible cardioprotective effects associated with mono-unsaturated dietary fat, particularly in subjects with the MetS.
Tau function and Hirota bilinear equations for the extended bigraded Toda hierarchy
Authors: Li Chuanzhong , He Jingsong , Wu Ke , Cheng Yi
Published: April 2010

In this paper, we generalize the Sato theory to the extended bigraded Toda hierarchy. We revise the definition of the Lax equations, give the Sato equations, wave operators, Hirota bilinear identities, and show the existence of tau function τ(t). Meanwhile, we prove the validity of its Fay-like identities and Hirota bilinear equations (HBEs) in terms of vertex operators whose coefficients take values in the algebra of differential operators. In contrast to HBEs of the usual integrable system, the current HBEs are equations of the product of operators involving e∂x and τ(t).
Lithium niobate crystals doped with iron by thermal diffusion: Relation between lattice deformation and reduction degree
Authors: Ciampolillo M. V. , Zaltron A. , Bazzan M. , Argiolas N. , Sada C. , Bianconi M.
Published: April 2010

We report, to our knowledge for the first time, on the experimental observation that the maximum lattice deformation induced at the surface of iron doped lithium niobate crystal by thermal diffusion depends on both the Fe concentration and the reduction degree of the doped layer itself. By exploiting a simple linear model, we suggest a description of this experimental evidence and we point out a procedure that allows the characterization of the in-depth profile of the [Fe2+]/[Fe3+] ratio.
Approximating the set of separable states using the positive partial transpose test
Authors: Beigi Salman , Shor Peter W.
Published: April 2010

The positive partial transpose test is one of the main criteria for detecting entanglement, and the set of states with positive partial transpose is considered as an approximation of the set of separable states. However, we do not know to what extent this criterion, as well as the approximation, is efficient. In this paper, we show that the positive partial transpose test gives no bound on the distance of a density matrix from separable states. More precisely, we prove that, as the dimension of the space tends to infinity, the maximum trace distance of a positive partial transpose state from separable states tends to 1. Using similar techniques, we show that the same result holds for other well-known separability criteria such as reduction criterion, majorization criterion, and symmetric extension criterion. We also bring in evidence that the sets of positive partial transpose states and separable states have totally different shapes.
Effect of proton energy on damage generation in irradiated silicon
Authors: Väyrynen S. , Räisänen J.
Published: April 2010

Czochralski- and float-zone- grown silicon detectors were irradiated with 2 to 5 MeV protons. Capacitance-voltage (CV) measurements served to deduce the effective doping profiles and current-voltage (IV) measurements served to obtaining information on irradiation-induced deep levels. The CV measurements show that the proton-induced net space charge is positive or negative depending on the energy of the bombarding ion. The commonly employed nonionizing energy loss hypothesis was tested with the low energy proton regime and prominent previously unobserved deviations from predictions were noted.
The regime diagram for premixed flame kernel-vortex interactions—Revisited
Authors: Vasudeo Nikhil , Echekki Tarek , Day Marcus S. , Bell John B.
Published: April 2010

Regimes of flame kernel-vortex (KV) interactions are investigated numerically using a detailed mechanism for hydrogen chemistry. The parametric simulations explore a wide range of conditions that are representative of conditions encountered at various degrees of turbulence intensity. The results show that KV interactions can be classified into five different regimes, which include (1) the laminar kernel regime, (2) the wrinkled kernel regime, (3) the breakthrough regime, (4) the global extinction regime, and (5) the regeneration after global extinction (RGE) regime. With the exception of the last regime, the transition from one regime to another in the order listed corresponds to increasing the vortex size and strength. Operation at the RGE regime reveals interesting dynamics of the flame front that results in reignition or mending of combustion regimes after most of the original kernel has extinguished due to intense straining. Two different types of combustion zones are observed, which correspond to a flamelet structure as well as to more diffuse structures of merged flame segments. A revised regime diagram of the KV interactions is proposed that includes the broader range of KV interactions and incorporates the new RGE regime.
The DCU laser ion source
Authors: Yeates P. , Costello J. T. , Kennedy E. T.
Published: April 2010

Laser ion sources are used to generate and deliver highly charged ions of various masses and energies. We present details on the design and basic parameters of the DCU laser ion source (LIS). The theoretical aspects of a high voltage (HV) linear LIS are presented and the main issues surrounding laser-plasma formation, ion extraction and modeling of beam transport in relation to the operation of a LIS are detailed. A range of laser power densities (I∼108–1011 W cm−2) and fluences (F=0.1–3.9 kJ cm−2) from a Q-switched ruby laser (full-width half-maximum pulse duration ∼35 ns, λ=694 nm) were used to generate a copper plasma. In “basic operating mode,” laser generated plasma ions are electrostatically accelerated using a dc HV bias (5–18 kV). A traditional einzel electrostatic lens system is utilized to transport and collimate the extracted ion beam for detection via a Faraday cup. Peak currents of up to I∼600 μA for Cu+ to Cu3+ ions were recorded. The maximum collected charge reached 94 pC (Cu2+). Hydrodynamic simulations and ion probe diagnostics were used to study the plasma plume within the extraction gap. The system measured performance and electrodynamic simulations indicated that the use of a short field-free (L=48 mm) region results in rapid expansion of the injected ion beam in the drift tube. This severely limits the efficiency of the electrostatic lens system and consequently the sources performance. Simulations of ion beam dynamics in a “continuous einzel array” were performed and experimentally verified to counter the strong space-charge force present in the ion beam which results from plasma extraction close to the target surface. Ion beam acceleration and injection thus occur at “high pressure.” In “enhanced operating mode,” peak currents of 3.26 mA (Cu2+) were recorded. The collected currents of more highly charged ions (Cu4+–Cu6+) increased considerably in this mode of operation.
Trapping properties of LiNbO3/AlGaN/GaN metal-ferroelectric-semiconductor heterostructure characterized by temperature dependent conductance measurements
Authors: Zeng Huizhong , Hao Lanzhong , Luo Wenbo , Liao Xiuwei , Huang Wen , Lin Yuan , Li Yanrong
Published: April 2010

The trapping properties of the ferroelectric LiNbO3/AlGaN/GaN heterostructure capacitors were characterized by temperature dependent capacitance and conductance measurements. In a wide temperature range (200–450 K), two kind of traps were identified by the conductance measurements. One is the interface trap with the density of 1.1×1012 to 1.4×1010 cm−2 eV−1 which shows an exponential dependency of time constant on the bias applied to the heterostructure. The other is the bulk trap with a lower density, about (1−4)×1010 cm−2 eV−1, which manifests at higher temperatures. The measured time constant of bulk traps (∼1 μs) is almost independent of bias, differing from that of interface traps (about 200 to 1 μs).
Hydrostatic pressure effects on the Landé g∥ factor in GaAs–Ga1−xAlxAs quantum heterostructures under applied magnetic fields
Authors: Mejía-Salazar J. R. , Porras-Montenegro N.
Published: April 2010

We have performed a theoretical study of the hydrostatic pressure effects on the conduction-electron Landé g∥ factor in GaAs–Ga1−xAlxAs quantum heterostructures (QHs) under the influence of applied magnetic fields. Numerical calculations are performed by using the Ogg–McCombe effective Hamiltonian, which include nonparabolicity and anisotropy effects for the conduction-band electrons. The QHs is assumed to consist of a finite-length cylinder of GaAs surrounded by Ga1−xAlxAs barrier. Theoretical results are given as functions of the radii, lengths, hydrostatic pressure, and applied magnetic fields. We have studied the competition between the geometrical and magnetic confinement versus hydrostatic pressure effects, finding that the geometrical confinement commands the behavior of the g∥ factor. Present theoretical results are in very good agreement with previous experimental and theoretical reports in GaAs–Ga1−xAlxAs heterostructures.
Evidence of intermolecular species formation with electrical aging in anthracene-based blue organic light-emitting devices
Authors: Wang Qi , Luo Yichun , Aziz Hany
Published: April 2010

Electrical aging mechanism in blue emitting organic light-emitting devices (OLEDs) based on 9,10-bis (2-naphthyl)-2-t-butyl anthracene (TBADN) fluorescent emitter is investigated using a number of techniques, including delayed electroluminescence measurements. The studies reveal that electrical aging is associated with an increasing concentration of an intermolecular species with a weak characteristic luminescence at around 535 nm. This species is capable of charge trapping, and thus plays a role as an electron-hole recombination center with prolonged electrical driving. Weak green luminescence from this species leads to an increased green/blue emission ratio, and causes the color purity loss in aged devices. The results also suggest that this species is also efficient in dissipating excitation energy nonradiatively, hence is capable of quenching TBADN singlet excitons, contributing to the observed efficiency loss with electrical aging.
Flow past a square cylinder with an angle of incidence
Authors: Yoon Dong-Hyeog , Yang Kyung-Soo , Choi Choon-Bum
Published: April 2010

A parametric study has been carried out to elucidate the characteristics of flow past a square cylinder inclined with respect to the main flow in the laminar flow regime. Reynolds number and angle of incidence are the key parameters which determine the flow characteristics. Location of separation point is greatly affected by angle of incidence, thus determining the flow field around the square cylinder. The critical Reynolds number for periodic vortex shedding at each angle of incidence considered is obtained by using Stuart–Landau equation. Attempt is made to classify the related flow patterns from a topological point of view, resulting in three distinct patterns in total. A comprehensive analysis of the effects of Reynolds number and angle of incidence on flow-induced forces on the square cylinder is presented. Collecting all the results obtained, contour diagrams of force and moment coefficients, Strouhal number, rms of lift-coefficient fluctuation, as well as a flow-pattern diagram are proposed for the ranges of the two parameters considered in the current investigation. Finally, a Floquet stability analysis is presented to detect the onset of the secondary instability leading to three-dimensional flow. The proposed diagrams and the Floquet stability analysis shed light on better physical understanding of the flow past a square cylinder, which should be useful in many engineering applications.
Partitioning of the molecular density matrix over atoms and bonds
Authors: Vanfleteren Diederik , Van Neck Dimitri , Bultinck Patrick , Ayers Paul W. , Waroquier Michel
Published: April 2010

A double-index atomic partitioning of the molecular first-order density matrix is proposed. Contributions diagonal in the atomic indices correspond to atomic density matrices, whereas off-diagonal contributions carry information about the bonds. The resulting matrices have good localization properties, in contrast to single-index atomic partitioning schemes of the molecular density matrix. It is shown that the electron density assigned to individual atoms, when derived from the density matrix partitioning, can be made consistent with well-known partitions of the electron density over atom in the molecule basins, either with sharp or with fuzzy boundaries. The method is applied to a test set of about 50 molecules, representative for various types of chemical binding. A close correlation is observed between the trace of the bond matrices and the shared electron density index.
Giant magnetocaloric effects by tailoring the phase transitions
Authors: Trung N. T. , Zhang L. , Caron L. , Buschow K. H. J. , Brück E.
Published: April 2010

The MnCoGe alloy can crystallize in either the hexagonal Ni2In- or the orthorhombic TiNiSi-type of structure. In both phases MnCoGe behaves like a typical ferromagnet with a second-order magnetic phase transition. For MnCoGeBx with B on interstitial positions, we discover a giant magnetocaloric effect associated with a single first-order magnetostructural phase transition, which can be achieved by tuning the magnetic and structural transitions to coincide. The results obtained on the MnCoGe-type alloys may be extensible to other types of magnetic materials undergoing a first-order structural transformation and can open up some possibilities for searching magnetic refrigerants for room-temperature applications.
Electron spin resonance observation of field-induced charge carriers in ultrathin-film transistors of regioregular poly(3-hexylthiophene) with controlled in-plane chain orientation
Authors: Watanabe Shun-ichiro , Tanaka Hisaaki , Kuroda Shin-ichi , Toda Akio , Nagano Shusaku , Seki Takahiro , Kimoto Atsushi , Abe Jiro
Published: April 2010

Ultrathin-film polymeric transistors with controlled in-plane chain orientation have been fabricated based on Langmuir–Blodgett technique by cospreading liquid crystal molecule with regioregular poly(3-hexylthiophene). The mobilities parallel to the chain direction reached 0.001–0.01 cm2/V s for 1 to 5 monolayer thick transistors. Mobility ratio was about 2 for the parallel and perpendicular directions. Electron spin resonance (ESR) signals of the field-induced polarons exhibited clear in-plane anisotropies due to unpaired π-electrons. The anisotropic ESR spectra together with the optical dichroism determine the detailed molecular orientations in the channel of such ultrathin transistors.
Requirement of CCL17 for CCR7- and CXCR4-dependent migration of cutaneous dendritic cells
Authors: Stutte Susanne , Quast Thomas , Gerbitzki Nancy , Savinko Terhi , Novak Nina , Reifenberger Julia , Homey Bernhard , Kolanus Waldemar , Alenius Harri , Förster Irmgard
Published: April 2010

Chemokines are known to regulate the steady-state and inflammatory migration of cutaneous dendritic cells (DCs). The β-chemokine CCL17, a ligand of CCR4, is inducibly expressed in a subset of DCs and is strongly up-regulated in atopic diseases. Using an atopic dermatitis model, we show that CCL17-deficient mice develop acanthosis as WT mice, whereas dermal inflammation, T helper 2-type cytokine production, and the allergen-specific humoral immune response are significantly decreased. Notably, CCL17-deficient mice retained Langerhans cells (LCs) in the lesional skin after chronic allergen exposure, whereas most LCs emigrated from the epidermis of allergen-treated WT controls into draining lymph nodes (LNs). Moreover, CCL17-deficient LCs showed impaired emigration from the skin after exposure to a contact sensitizer. In contrast, the absence of CCR4 had no effect on cutaneous DC migration and development of atopic dermatitis symptoms. As an explanation for the major migratory defect of CCL17-deficient DCs in vivo, we demonstrate impaired mobility of CCL17-deficient DCs to CCL19/21 in 3D in vitro migration assays and a blockade of intracellular calcium release in response to CCR7 ligands. In addition, responsiveness of CCL17-deficient DCs to CXCL12 was impaired as well. We demonstrate that the inducible chemokine CCL17 sensitizes DCs for CCR7- and CXCR4-dependent migration to LN-associated homeostatic chemokines under inflammatory conditions and thus plays an important role in cutaneous DC migration.
ACTH protects against glucocorticoid-induced osteonecrosis of bone
Authors: Zaidi Mone , Sun Li , Robinson Lisa J. , Tourkova Irina L. , Liu Li , Wang Yujuan , Zhu Ling-Ling , Liu Xuan , Li Jianhua , Peng Yuanzhen , Yang Guozhe , Shi Xingming , Levine Alice , Iqbal Jameel , Yaroslavskiy Beatrice B. , Isales Carlos , Blair Harry C.
Published: April 2010

We report that adrenocorticotropic hormone (ACTH) protects against osteonecrosis of the femoral head induced by depot methylprednisolone acetate (depomedrol). This therapeutic response likely arises from enhanced osteoblastic support and the stimulation of VEGF by ACTH; the latter is largely responsible for maintaining the fine vascular network that surrounds highly remodeling bone. We suggest examining the efficacy of ACTH in preventing human osteonecrosis, a devastating complication of glucocorticoid therapy.
Adaptive evolution of energy metabolism genes and the origin of flight in bats
Authors: Shen Yong-Yi , Liang Lu , Zhu Zhou-Hai , Zhou Wei-Ping , Irwin David M. , Zhang Ya-Ping
Published: April 2010

Bat flight poses intriguing questions about how flight independently developed in mammals. Flight is among the most energy-consuming activities. Thus, we deduced that changes in energy metabolism must be a primary factor in the origin of flight in bats. The respiratory chain of the mitochondrial produces 95% of the adenosine triphosphate (ATP) needed for locomotion. Because the respiratory chain has a dual genetic foundation, with genes encoded by both the mitochondrial and nuclear genomes, we examined both genomes to gain insights into the evolution of flight within mammals. Evidence for positive selection was detected in 23.08% of the mitochondrial-encoded and 4.90% of nuclear-encoded oxidative phosphorylation (OXPHOS) genes, but in only 2.25% of the nuclear-encoded nonrespiratory genes that function in mitochondria or 1.005% of other nuclear genes in bats. To address the caveat that the two available bat genomes are of only draft quality, we resequenced 77 OXPHOS genes from four species of bats. The analysis of the resequenced gene data are in agreement with our conclusion that a significantly higher proportion of genes involved in energy metabolism, compared with background genes, show evidence of adaptive evolution specific on the common ancestral bat lineage. Both mitochondrial and nuclear-encoded OXPHOS genes display evidence of adaptive evolution along the common ancestral branch of bats, supporting our hypothesis that genes involved in energy metabolism were targets of natural selection and allowed adaptation to the huge change in energy demand that were required during the origin of flight.
Identification of a methylase required for 2-methylhopanoid production and implications for the interpretation of sedimentary hopanes
Authors: Welander Paula V. , Coleman Maureen L. , Sessions Alex L. , Summons Roger E. , Newman Dianne K.
Published: April 2010

The rise of atmospheric oxygen has driven environmental change and biological evolution throughout much of Earth’s history and was enabled by the evolution of oxygenic photosynthesis in the cyanobacteria. Dating this metabolic innovation using inorganic proxies from sedimentary rocks has been difficult and one important approach has been to study the distributions of fossil lipids, such as steranes and 2-methylhopanes, as biomarkers for this process. 2-methylhopanes arise from degradation of 2-methylbacteriohopanepolyols (2-MeBHPs), lipids thought to be synthesized primarily by cyanobacteria. The discovery that 2-MeBHPs are produced by an anoxygenic phototroph, however, challenged both their taxonomic link with cyanobacteria and their functional link with oxygenic photosynthesis. Here, we identify a radical SAM methylase encoded by the
hpnP
gene that is required for methylation at the C-2 position in hopanoids. This gene is found in several, but not all, cyanobacteria and also in α -proteobacteria and acidobacteria. Thus, one cannot extrapolate from the presence of 2-methylhopanes alone, in modern environments or ancient sedimentary rocks, to a particular taxonomic group or metabolism. To understand the origin of this gene, we reconstructed the evolutionary history of HpnP. HpnP proteins from cyanobacteria,
Methylobacterium
species, and other α-proteobacteria form distinct phylogenetic clusters, but the branching order of these clades could not be confidently resolved. Hence,it is unclear whether HpnP, and 2-methylhopanoids, originated first in the cyanobacteria. In summary, existing evidence does not support the use of 2-methylhopanes as biomarkers for oxygenic photosynthesis.
RNAi and heterochromatin repress centromeric meiotic recombination
Authors: Ellermeier Chad , Higuchi Emily C. , Phadnis Naina , Holm Laerke , Geelhood Jennifer L. , Thon Genevieve , Smith Gerald R.
Published: April 2010

During meiosis, the formation of viable haploid gametes from diploid precursors requires that each homologous chromosome pair be properly segregated to produce an exact haploid set of chromosomes. Genetic recombination, which provides a physical connection between homologous chromosomes, is essential in most species for proper homologue segregation. Nevertheless, recombination is repressed specifically in and around the centromeres of chromosomes, apparently because rare centromeric (or pericentromeric) recombination events, when they do occur, can disrupt proper segregation and lead to genetic disabilities, including birth defects. The basis by which centromeric meiotic recombination is repressed has been largely unknown. We report here that, in fission yeast, RNAi functions and Clr4-Rik1 (histone H3 lysine 9 methyltransferase) are required for repression of centromeric recombination. Surprisingly, one mutant derepressed for recombination in the heterochromatic mating-type region during meiosis and several mutants derepressed for centromeric gene expression during mitotic growth are not derepressed for centromeric recombination during meiosis. These results reveal a complex relation between types of repression by heterochromatin. Our results also reveal a previously undemonstrated role for RNAi and heterochromatin in the repression of meiotic centromeric recombination and, potentially, in the prevention of birth defects by maintenance of proper chromosome segregation during meiosis.
Individual identity and movement networks for disease metapopulations
Authors: Keeling Matt J. , Danon Leon , Vernon Matthew C. , House Thomas A.
Published: April 2010

The theory of networks has had a huge impact in both the physical and life sciences, shaping our understanding of the interaction between multiple elements in complex systems. In particular, networks have been extensively used in predicting the spread of infectious diseases where individuals, or populations of individuals, interact with a limited set of others—defining the network through which the disease can spread. Here for such disease models we consider three assumptions for capturing the network of movements between populations, and focus on two applied problems supported by detailed data from Great Britain: the commuter movement of workers between local areas (wards) and the permanent movement of cattle between farms. For such metapopulation networks, we show that the identity of individuals responsible for making network connections can have a significant impact on the infection dynamics, with clear implications for detailed public health and veterinary applications.
Transmissibility and geographic spread of the 1889 influenza pandemic
Authors: Valleron Alain-Jacques , Cori Anne , Valtat Sophie , Meurisse Sofia , Carrat Fabrice , Boëlle Pierre-Yves
Published: April 2010

Until now, mortality and spreading mechanisms of influenza pandemics have been studied only for the 1918, 1957, and 1968 pandemics; none have concerned the 19th century. Herein, we examined the 1889 “Russian” pandemic. Clinical attack rates were retrieved for 408 geographic entities in 14 European countries and in the United States. Case fatality ratios were estimated from datasets in the French, British and German armies, and morbidity and mortality records of Swiss cities. Weekly all-cause mortality was analyzed in 96 European and American cities. The pandemic spread rapidly, taking only 4 months to circumnavigate the planet, peaking in the United States 70 days after the original peak in St. Petersburg. The median and interquartile range of clinical attack rates was 60% (45–70%). The case fatality ratios ranged from 0.1% to 0.28%, which is comparable to those of 1957 and 1968, and 10-fold lower than in 1918. The median basic reproduction number (

R
0

) was 2.1, which is comparable to the values found for the other pandemics, despite the different viruses and contact networks.

R
0

values varied widely from one city to another, and only a small minority of those values was within the range in which modelers’ mitigation scenarios predicted effectiveness. The 1889 and 1918

R
0

correlated for the subset of cities for which both values were available. Social and geographic factors probably shape the local

R
0

, and they could be identified to design optimal mitigation scenarios tailored to each city.
Different amygdala subregions mediate valence-related and attentional effects of oxytocin in humans
Authors: Gamer Matthias , Zurowski Bartosz , Büchel Christian
Published: April 2010

The neuropeptide oxytocin enhances the processing of positive social stimuli and improves the capacity to effectively attend the eye region of conspecifics. To investigate the neural basis of these effects, we combined intranasal oxytocin administration with high-resolution functional magnetic resonance imaging in a unique emotion classification task. Emotional faces were briefly presented while controlling for the initial fixation, and measuring subsequent eye movements. Oxytocin had differential effects on the activity of specific amygdala subregions. On the one hand, it attenuated activation in lateral and dorsal regions of the anterior amygdala for fearful faces but enhanced activity for happy expressions, thus indicating a shift of the processing focus toward positive social stimuli. On the other hand, oxytocin increased the likelihood of reflexive gaze shifts toward the eye region irrespective of the depicted emotional expression. This gazing pattern was related to an increase of activity in the posterior amygdala and an enhanced functional coupling of this region to the superior colliculi. Thus, different behavioral effects of oxytocin seem to be closely related its specific modulatory influence on subregions within the human amygdala.
Urinary excretion of morphine and biosynthetic precursors in mice
Authors: Grobe Nadja , Lamshöft Marc , Orth Robert G. , Dräger Birgit , Kutchan Toni M. , Zenk Meinhart H. , Spiteller Michael
Published: April 2010

It has been firmly established that humans excrete a small but steady amount of the isoquinoline alkaloid morphine in their urine. It is unclear whether it is of dietary or endogenous origin. There is no doubt that a simple isoquinoline alkaloid, tetrahydropapaveroline (THP), is found in human and rodent brain as well as in human urine. This suggests a potential biogenetic relationship between both alkaloids. Unlabeled THP or [1,3,4-D3]-THP was injected intraperitoneally into mice and the urine was analyzed. This potential precursor was extensively metabolized (96%). Among the metabolites found was the phenol-coupled product salutaridine, the known morphine precursor in the opium poppy plant. Synthetic [7D]-salutaridinol, the biosynthetic reduction product of salutaridine, injected intraperitoneally into live animals led to the formation of [7D]-thebaine, which was excreted in urine. [N-CD3]-thebaine was also administered and yielded [N-CD3]-morphine and the congeners [N-CD3]-codeine and [N-CD3]-oripavine in urine. These results show for the first time that live animals have the biosynthetic capability to convert a normal constituent of rodents, THP, to morphine. Morphine and its precursors are normally not found in tissues or organs, presumably due to metabolic breakdown. Hence, only that portion of the isoquinoline alkaloids excreted in urine unmetabolized can be detected. Analysis of urine by high resolution-mass spectrometry proved to be a powerful method for tracking endogenous morphine and its biosynthetic precursors.