bluuebunny/crossref_metadata_2025 huggingface dataset:
Reversible photoswitching conjugated polymer nanoparticles for cell and ex vivo tumor imaging
Authors: Feng Guangxue , Ding Dan , Li Kai , Liu Jie , Liu Bin
Published: January 2014

Fluorescent photoswitchable conjugated polymer nanoparticles for cell and ex vivo tumour imaging with fluorescence on/off contrast over 10-fold in tumour.
Chemoselective and repetitive intermolecular cross-acyloin condensation reactions between a variety of aromatic and aliphatic aldehydes using a robust N-heterocyclic carbene catalyst
Authors: Jin Ming Yu , Kim Sun Min , Mao Hui , Ryu Do Hyun , Song Choong Eui , Yang Jung Woon
Published: January 2014

Chemoselectivity of the crossed acyloin product is controlled by the adjustment of the aromatic aldehyde/aliphatic aldehyde ratio.
Beyond perylene diimides: synthesis, assembly and function of higher rylene chromophores
Authors: Chen Long , Li Chen , Müllen Klaus
Published: January 2014

This feature article highlights the latest advances in synthetic strategies toward preparation of rylene chromophores as well as their self-assembly behaviour and applications.
Electrically pumped polariton lasers
Authors: Wei Cong , Sheng Zhao Yong
Published: January 2014

Exciton–polariton lasers under fermions injection: a condensation of exciton–polaritons was achieved in a microcavity sandwiched by two gradually doped distributed Bragg reflectors with electrical pumping. The polariton laser with an electron–polariton scattering process offers a platform to investigate the interaction between bosons and fermions and an effective way to generate coherent light.
Clustering Gaussian mixture reduction algorithm based on fuzzy adaptive resonance theory for extended target tracking
Authors: Zhang Yongquan , Ji Hongbing
Published: January 2014

This study presents a global Gaussian mixture reduction (GMR) algorithm via clustering, which is based on a fuzzy adaptive resonance theory (FART) neural network architecture. Therefore the authors call the proposed algorithm as GMR based on the fuzzy ART (GMR‐FART) in this study. The architecture of GMR‐FART is similar to that of the FART, however, its choice function, match function and learning update equations are characterised by features of Gaussian mixture (GM). The proposed algorithm automatically forms categories (i.e. the reduced GM components) via a feedback mechanism. The performance of GMR‐FART is evaluated by the normalised integrated squared distance measure which describes the deviation between the original and the reduced GM. The proposed algorithm is tested on both one‐dimensional (1D) and 4D simulation examples, and the results show that the proposed algorithm can accurately approximate the original mixture and requires less computational burden, and is useful in extended target tracking.
Disstress in der Chirurgie – Eine Untersuchung in deutschen Krankenhäusern
Authors: Bauer J. , Groneberg D.
Published: January 2014

Hintergrund Stress am Arbeitsplatz mit negativen Auswirkungen auf die Gesundheit (Disstress) ist gerade im Fachgebiet der Chirurgie weit verbreitet. Deswegen spielen die subjektiv wahrgenommenen Arbeitsbedingungen der Ärztinnen und Ärzte in der Chirurgie eine erhebliche Rolle für die eigene Gesundheit und die Gesundheit der Patienten. Wie die Arbeitsbedingungen im Fachgebiet der Chirurgie konkret wahrgenommen werden, soll durch die vorliegende Studie geklärt werden.

Material und Methoden Diese webbasierte Studie, an der 1142 Ärzte und Ärztinnen der Chirurgie teilnahmen, stützt sich methodisch auf das Effort-Reward-Imbalance (ERI) Modell von Siegrist und das Job-Demand-Control Modell von Karasek. Der für diese Studie auf Basis der beiden Modelle konzipierte Fragebogen besteht aus Items zweier validierter und etablierter Fragebögen. Dadurch lässt sich eine Aussage über die Berufszufriedenheit und Disstress-Prävalenz im Fachgebiet der Chirurgie treffen.

Ergebnisse In dieser Studie gaben 58,2% (95%-KI: 55,6 – 61,5) der Befragten ungünstige Arbeitsbedingungen in Form von Disstress (ER/JDC-Ratio > 1) an. Gleichzeitig war mit 52,2% (95%-KI: 49,3 – 55,1) ungefähr die Hälfte der Befragten sehr zufrieden mit ihrem Beruf. Bei Ärztinnen lag die Disstress-Prävalenz um 6 Prozentpunkte höher (95%-KI: 0,1 – 12,0) bei 62,4% und war damit signifikant höher als bei Ärzten (OR: 1,29; 95%-KI: 1,01 – 1,65; p < 0,05). In Betrachtung der in dieser Studie untersuchten 4 funktionalen Stellungen im Krankenhaus wiesen Chefärzte/-ärztinnen mit 22,0% die niedrigste Disstress-Prävalenz auf. Die höchste Disstress-Prävalenz wiesen Fachärzte mit 66,7% auf (OR: 7,11; 95%-KI: 3,26 – 15,48; p < 0,001). Weiterhin gaben 43,4% der befragten Fachärzte/-ärztinnen an, sehr zufrieden mit ihrem Beruf zu sein. Bei Oberärzten/-ärztinnen gaben dies 61,5% an (OR: 2,08; 95%-KI: 1,52 – 2,84; p < 0,001).

Schlussfolgerungen Die dargestellten Daten unterstreichen ein hohes Stresspotenzial des Fachgebiets der Chirurgie in Bezug auf die Arbeitsbedingungen. Im Hinblick auf das Potenzial und Personal, welches durch eine Verbesserung der Arbeitsbedingungen im Fachgebiet der Chirurgie in den Kliniken gehalten werden könnte, sollte auf ein Gleichgewicht entsprechend des ERI/JDC-Modells geachtet werden.
Everything Counts in Large Amounts: A Critical Realist Case Study on Data-Based Production
Authors: Aaltonen Aleksi , Tempini Niccoló
Published: January 2014

Contemporary digital ecosystems produce vast amounts of data every day. The data are often no more than microscopic log entries generated by the elements of an information infrastructure or system. Although such records may represent a variety of things outside the system, their powers go beyond the capacity to carry semantic content. In this article, we harness critical realism to explain how such data come to matter in specific business operations. We analyse the production of an advertising audience from data tokens extracted from a telecommunications network. The research is based on an intensive case study of a mobile network operator that tries to turn its subscribers into an advertising audience. We identify three mechanisms that shape data-based production and three properties that characterize the underlying pool of data. The findings advance the understanding of many organizational settings that are centred on data processing.
Development of the front end test stand and vessel for extraction and source plasma analyses negative hydrogen ion sources at the Rutherford Appleton Laboratory
Authors: Lawrie S. R. , Faircloth D. C. , Letchford A. P. , Perkins M. , Whitehead M. O. , Wood T. , Gabor C. , Back J.
Published: January 2014

The ISIS pulsed spallation neutron and muon facility at the Rutherford Appleton Laboratory (RAL) in the UK uses a Penning surface plasma negative hydrogen ion source. Upgrade options for the ISIS accelerator system demand a higher current, lower emittance beam with longer pulse lengths from the injector. The Front End Test Stand is being constructed at RAL to meet the upgrade requirements using a modified ISIS ion source. A new 10% duty cycle 25 kV pulsed extraction power supply has been commissioned and the first meter of 3 MeV radio frequency quadrupole has been delivered. Simultaneously, a Vessel for Extraction and Source Plasma Analyses is under construction in a new laboratory at RAL. The detailed measurements of the plasma and extracted beam characteristics will allow a radical overhaul of the transport optics, potentially yielding a simpler source configuration with greater output and lifetime.
Reactions between cold methyl halide molecules and alkali-metal atoms
Authors: Lutz Jesse J. , Hutson Jeremy M.
Published: January 2014

We investigate the potential energy surfaces and activation energies for reactions between methyl halide molecules CH3X (X = F, Cl, Br, I) and alkali-metal atoms A (A = Li, Na, K, Rb) using high-level ab initio calculations. We examine the anisotropy of each intermolecular potential energy surface (PES) and the mechanism and energetics of the only available exothermic reaction pathway, CH3X + A → CH3 + AX. The region of the transition state is explored using two-dimensional PES cuts and estimates of the activation energies are inferred. Nearly all combinations of methyl halide and alkali-metal atom have positive barrier heights, indicating that reactions at low temperatures will be slow.
Electronic structures and ferromagnetism of SnO2 (rutile) doped with double-impurities: First-principles calculations
Authors: Fakhim Lamrani A. , Belaiche M. , Benyoussef A. , Kenz El
Published: January 2014

The electronic and magnetic properties of double-impurities-doped SnO2 (rutile) are explored using first-principles calculations within the generalized gradient approximation to examine their potential use as spintronic system. Calculations are performed for double impurities (M1 and M2) from M1 = Cr, and M2 = Mn, and Re. The origins of ferromagnetism are shown to be different in the two cases. For Sn1-2xCrxMnxO2, the hybridization between Cr-3d and O-2p results in Cr becoming ferromagnetic with a magnetic moment of about 5.0 μB per supercell. The Cr-and Mn-doped SnO2 system exhibits half-metallic ferromagnetism. The strong ferromagnetic couplings between local magnetic moments can be attributed to p-d hybridization. In contrast, in (Cr, Re) codoped TiO2, the local magnetic moments of the impurities and their oxidation states agree with the charge transfer between Cr and Re, which would lead to the ferromagnetic through the double-exchange mechanism in transition metal oxides. Since there are two possible couplings between the impurities, we studied both configurations (ferromagnetic and antiferromagnetic (AF)) for double-impurities-doped SnO2. Our calculations show that a ferromagnetic alignment of the spins is energetically always more stable than simple AF arrangements, which makes these materials possible candidates for spin injection in spintronic devices.
Electronic and magnetic properties of double perovskite Dy2MnCoO6 by first-principles calculation
Authors: Ganeshraj C. , Santhosh P. N.
Published: January 2014

Using first-principles calculation, we investigate electronic and magnetic properties of Dy2MnCoO6. A detailed structural optimization has been done and found that the orthorhombic structure with Mn (Co) ions aligning along the longest axis type is the most stable structure. Within the generalized gradient approximation, the spin polarized calculations predict Dy2MnCoO6 to be a half-metallic with ferromagnetic interaction between Mn and Co ions and antiferromagnetic interaction between Dy and Mn/Co ions. We also investigate the effect of Hubbard parameter (U) on the ground state magnetic structure. For all values of Hubbard U parameter the Co ions have nonzero magnetic moment; they do not lie in low-spin state, as in DyCoO3.
An effective medium study of surface plasmon polaritons in nanostructured gratings using attenuated total reflection
Authors: Tyboroski M. H. , Anderson N. R. , Camley R. E.
Published: January 2014

Recent work studied surface plasmon resonances in structured materials by the method of attenuated total reflection using a prism on top of a metallic grating. That calculation considered Transverse Magnetic polarized radiation, involved an expansion in 121 Fourier modes, and found a number of interesting features. Many of these features were attributed to localized plasmons or other factors, which arise from a discrete structure. We use a simple effective medium theory to address the same problem, and find many of the same reflection features observed in the more complex calculation, indicating that localization is not an important factor. We also evaluate the possibility of using some of the new features in the reflection spectrum for bio-sensing and find that the sensitivity of the system to small changes in relative permittivity is increased compared to some standard methods.
Electromagnetic analysis and experimental testing of a light switchwith a permanent magnet generator for energy harvesting based on three dimensional finite element model
Authors: Shin Hyeon-Jae , Choi Jang-Young , Kim Il-Jung , Choi Yeon-Suk
Published: January 2014

This paper presents a small-size permanent magnet generator for an energy harvester. The generator is suitable for a switch, as it uses a magnetic force as the retention force and the force of motion to recognize switch operation. In addition, the induced voltages have positive or negative values depending on the switching direction. It is possible to monitor switch operation for achieving intelligent power consumption. Finally, measurements of the generated voltage are presented to reveal the effectiveness of the energy harvester.
Design study of a 17.3 GHz electron cyclotron resonance (ECR) ion source at Louvain-la-Neuve
Authors: Standaert L. , Davin F. , Loiselet M.
Published: January 2014

The Cyclotron Resources Center of the Louvain-la-Neuve University is developing a new electron cyclotron resonance ion source to increase the energy of the accelerated beam by injection of higher charge state ions into the cyclotron. The design of the source is based on a 17.3 GHz frequency and classical coils to produce the axial field. The field reaches 2 T at the injection side and 1.2 T at extraction. The total power consumption for the coils is limited to 80 kW. The design features of the source are presented.
Electron-beam-induced current at absorber back surfaces of Cu(In,Ga)Se2 thin-film solar cells
Authors: Kavalakkatt J. , Abou-Ras D. , Haarstrich J. , Ronning C. , Nichterwitz M. , Caballero R. , Rissom T. , Unold T. , Scheer R. , Schock H. W.
Published: January 2014

The present work reports on investigations of the influence of the microstructure on electronic properties of Cu(In,Ga)Se2 (CIGSe) thin-film solar cells. For this purpose, ZnO/CdS/CIGSe stacks of these solar cells were lifted off the Mo-coated glass substrates. The exposed CIGSe backsides of these stacks were investigated by means of electron-beam-induced current (EBIC) and cathodoluminescence (CL) measurements as well as by electron backscattered diffraction (EBSD). EBIC and CL profiles across grain boundaries (GBs), which were identified by EBSD, do not show any significant changes at Σ3 GBs. Across non-Σ3 GBs, on the other hand, the CL signals exhibit local minima with varying peak values, while by means of EBIC, decreased and also increased short-circuit current values are measured. Overall, EBIC and CL signals change across non-Σ3 GBs always differently. This complex situation was found in various CIGSe thin films with different [Ga]/([In]+[Ga]) and [Cu]/([In]+[Ga]) ratios. A part of the EBIC profiles exhibiting reduced signals across non-Σ3 GBs can be approximated by a simple model based on diffusion of generated charge carriers to the GBs.
Non-modal stability in Hagen-Poiseuille flow of a Bingham fluid
Authors: Liu Rong , Liu Qiu Sheng
Published: January 2014

Linear stability in Hagen-Poiseuille flow of a Bingham fluid is considered. Bingham fluid exhibits a yield stress in addition to a plastic viscosity. A Bingham number B, which describes the ratio of yield and viscous stresses, is used to characterize the behavior of Bingham-Hagen-Poiseuille flow. The effects of B on the stability are investigated using the energy method and the non-modal stability theory. The energy analysis shows that the non-axisymmetric disturbance has the lowest critical energy Reynolds number for all B. The global critical energy Reynolds number Reg increases with B. At sufficient large B, Reg has the order of B1/2. For the non-modal stability, we focus on response to external excitations and initial conditions. The former is studied by examining the ε-pseudospectrum, and the latter is by examining the energy growth function G(t). For the problem of response to external excitations, the maximum response is achieved by non-axisymmetric and streamwise uniform disturbances at the frequency of ω = 0, with a possible choice of the azimuthal wavenumbers of n = 1, 2, or 3. For the problem of response to initial conditions, it is found that there can be a rather large transient growth even though the linear operator of the Bingham-Hagen-Poiseuille flow has no unstable eigenvalue. For small B, the optimal disturbance is in the form of streamwise uniform vortices and streaks. For large B, the optimal disturbance is in the form of oblique waves. The optimal energy growth decreases and the optimal azimuthal wavenumber increases with the increase of B.
Optical signatures of photoinduced Zn vacancies in ZnO single crystal
Authors: Khan Enamul H.
Published: January 2014

193-nm excimer laser interaction with ZnO single-crystal at 0.05–500 KW/cm2 intensities is investigated under ultra high vacuum conditions by time resolved photoluminescence (PL) spectroscopy. A dominant 3.18 eV PL emission band at 295 K is observed. This band shows unusually long 0.52 ± 0.01 μs lifetime, indicating a defect mediated emission mechanism. The demonstrated negative thermal quenching for this band confirms its free electron to acceptor type transition. The involved acceptor is attributed to zinc vacancy with ∼100 meV shallow acceptor state. This study finds that 193-nm interactions produce Zn vacancies in transient states at 0.05–50 KW/cm2 excitation intensities and in stable state at 500 KW/cm2 or above intensities. The transient zinc vacancy production at such low intensities further validates the Frenkel pair creation as mechanism for creating these defects in ZnO single-crystal.
On the valve nature of a monolayer of aligned molecular magnets in tunneling spin-polarized electrons: Towards organic molecular spintronics
Authors: Chakrabarti Sudipto , Pal Amlan J.
Published: January 2014

We form a monolayer of magnetic organic molecules and immobilize their moments pointing either upwards or downwards with respect to the substrate through an electrostatic-binding process. Such a monolayer is probed with a scanning tunneling microscope tip, which is also magnetized with the magnetization vector pointing towards (or away from) apex of the tip. From spin-polarized tunneling current, we show that the current was higher when magnetization vectors of the tip and molecules were parallel as compared to that when they were anti-parallel. We show that for tunneling of spin-polarized electrons, aligned organic molecular magnets can act as a valve.
Influence of direct bias current on the electromagnetic properties of melt-extracted microwires and their composites
Authors: Qin F. X. , Tang J. , Popov V. V. , Liu J. S. , Peng H. X. , Brosseau C.
Published: January 2014

We study the influence of a direct bias current on the magnetoimpedance (MI) in melt-extracted amorphous CoFeSiB microwires and the effective electromagnetic properties of epoxy composites filled with these microwires. Our analysis reveals two remarkable features of the current dependence of MI in the range of gigahertz frequencies: a redshift of the dielectric resonance frequency and a decrease of the peak resonance of the effective permittivity as the bias current increases. Both effects are intrinsically linked to the influence of the polymer matrix on the magnetic structure and properties of the microwires. A discussion of these results is proposed in terms of two competing effects of the bias current, i.e., the induced additional effective field in the plane normal to the wire axis and the stress relief from Joule heating.
Resistive magneto-hydrodynamical cut-off of Alfvén wave in fully ionized plasmas
Authors: Vranjes J. , Kono M.
Published: January 2014

The term cut-off in the theory of the Alfvén wave is used to describe several different phenomena. In this work, the cut-off due to magnetohydrodynamic resistive damping in fully ionized plasmas is revisited. This cut-off requires short enough wavelengths, it is routinely discussed in numerous works, and graphs depicting it are available even in textbooks. We show that this cut-off is hardly ever possible in real plasmas. This is due to the fact that some essential criteria and conditions become strongly violated in order to achieve the cut-off.
Three-terminal resistive switching memory in a transparent vertical-configuration device
Authors: Ungureanu Mariana , Llopis Roger , Casanova Fèlix , Hueso Luis E.
Published: January 2014

The resistive switching phenomenon has attracted much attention recently for memory applications. It describes the reversible change in the resistance of a dielectric between two non-volatile states by the application of electrical pulses. Typical resistive switching memories are two-terminal devices formed by an oxide layer placed between two metal electrodes. Here, we report on the fabrication and operation of a three-terminal resistive switching memory that works as a reconfigurable logic component and offers an increased logic density on chip. The three-terminal memory device we present is transparent and could be further incorporated in transparent computing electronic technologies.
Orientation-dependent piezoelectricity and domain characteristics of tetragonal Pb(Zr0.3,Ti0.7)0.98Nb0.02O3 thin films on Nb-doped SrTiO3 substrates
Authors: Yu Qi , Li Jing-Feng , Sun Wei , Zhu Fang-Yuan , Liu Yuanming , Chen Yanna , Wang Zhanjie , Li Jiangyu
Published: January 2014

For a better understanding of piezoelectricity in epitaxial film systems, epitaxially grown tetragonal Pb(Zr0.3Ti0.7)0.98Nb0.02O3 (PNZT) thin films with three primary crystallographic orientations were studied with a focus on their piezoelectric behaviors and domain configuration. Using piezoresponse force microscopy, the (001)-oriented epitaxial films were found to show superior piezoelectric properties compared with the (110)- and (111)-oriented films. This can be attributed to the structural characteristics of the tetragonal PNZT phase after applying an electrical field. Island-distributed domain shapes were also mapped for all three orientations.
Note: Nonpolar solute partial molar volume response to attractive interactions with water
Authors: Williams Steven M. , Ashbaugh Henry S.
Published: January 2014

The impact of attractive interactions on the partial molar volumes of methane-like solutes in water is characterized using molecular simulations. Attractions account for a significant 20% volume drop between a repulsive Weeks-Chandler-Andersen and full Lennard-Jones description of methane interactions. The response of the volume to interaction perturbations is characterized by linear fits to our simulations and a rigorous statistical thermodynamic expression for the derivative of the volume to increasing attractions. While a weak non-linear response is observed, an average effective slope accurately captures the volume decrease. This response, however, is anticipated to become more non-linear with increasing solute size.
Persistence of social signatures in human communication
Authors: Saramäki Jari , Leicht E. A. , López Eduardo , Roberts Sam G. B. , Reed-Tsochas Felix , Dunbar Robin I. M.
Published: January 2014

Significance

We combine cell phone data with survey responses to show that a person’s social signature, as we call the pattern of their interactions with different friends and family members, is remarkably robust. People focus a high proportion of their communication efforts on a small number of individuals, and this behavior persists even when there are changes in the identity of the individuals involved. Although social signatures vary between individuals, a given individual appears to retain a specific social signature over time. Our results are likely to reflect limitations in the ability of humans to maintain many emotionally close relationships, both because of limited time and because the emotional “capital” that individuals can allocate between family members and friends is finite.
Resonant secondary light emission from plasmonic Au nanostructures at high electron temperatures created by pulsed-laser excitation
Authors: Huang Jingyu , Wang Wei , Murphy Catherine J. , Cahill David G.
Published: January 2014

Significance

Light emission from plasmonic nanostructures at wavelengths shorter than the wavelength of pulsed-laser excitation is typically described as two-photon absorption followed by fluorescence. In this work, we present an alternate description of the secondary light emission as a resonant electronic Raman scattering process. Experiments on aqueous suspensions of Au nanorods are quantitatively described by a two-temperature model. The results will facilitate the design of imaging experiments and understanding of background in surface-enhanced Raman scattering.
Mismatch repair protein hMSH2–hMSH6 recognizes mismatches and forms sliding clamps within a D-loop recombination intermediate
Authors: Honda Masayoshi , Okuno Yusuke , Hengel Sarah R. , Martín-López Juana V. , Cook Christopher P. , Amunugama Ravindra , Soukup Randal J. , Subramanyam Shyamal , Fishel Richard , Spies Maria
Published: January 2014

Significance

Recombination between divergent DNA sequences (homeologous recombination) is generally suppressed to preserve cellular genetic integrity and to ultimately introduce genetic barriers between species. Decades of genetic and cell biology studies have identified the involvement of the mismatch repair (MMR) machinery in the quality control of homologous recombination. However, the molecular mechanism by which this remarkable control is achieved is unknown. Here, we report the biophysical reconstitution and analysis of the early steps in the rejection of divergent DNA sequences by the MMR machinery during recombination initiation. We have determined that the first responder of MMR, human MutS-homolog hMSH2–hMSH6, efficiently recognizes mismatches within a D-loop recombination initiation intermediate, even in the presence of recombination initiation proteins HsRAD51 and human replication protein A (HsRPA).
Biological clockwork underlying adaptive rhythmic movements
Authors: Iwasaki Tetsuya , Chen Jun , Friesen W. Otto
Published: January 2014

Significance

Animals can adapt the frequency and shape of their oscillatory body movements during locomotion in response to changes in the environment. Although central pattern generators (CPGs) are known to be the basic neuronal circuits responsible for generation of rhythmic movements, no conclusive evidence has so far been found to attribute adaptive behaviors solely to the function of CPGs. We have found a blueprint of a design by nature in terms of mathematical equations. Experimental and computational studies presented in this article demonstrate that CPGs are indeed capable of adapting oscillations to the environment through sensory feedback, but without detailed guidance from the brain.
UCP2 transports C4 metabolites out of mitochondria, regulating glucose and glutamine oxidation
Authors: Vozza Angelo , Parisi Giovanni , De Leonardis Francesco , Lasorsa Francesco M. , Castegna Alessandra , Amorese Daniela , Marmo Raffaele , Calcagnile Valeria M. , Palmieri Luigi , Ricquier Daniel , Paradies Eleonora , Scarcia Pasquale , Palmieri Ferdinando , Bouillaud Frédéric , Fiermonte Giuseppe
Published: January 2014

Significance

Mitochondrial carriers constitute a large family of transport proteins that play important roles in the intracellular translocation of metabolites, nucleotides, and coenzymes. Despite considerable research efforts, the biochemical function of Uncoupling protein 2 (UCP2), a member of the mitochondrial carrier family reported to be involved in numerous pathologies, is still elusive. Here we show that UCP2 catalyzes an exchange of malate, oxaloacetate, and aspartate for phosphate, and that it exports C4 metabolites from mitochondria to the cytosol in vivo. Our findings also provide evidence that UCP2 activity limits mitochondrial oxidation of glucose and enhances glutaminolysis. These results provide a unique regulatory mechanism in cell bioenergetics and explain the significance of UCP2 levels in metabolic reprogramming occurring under various physiopathological conditions.
Probing nanoparticle translocation across the permeable endothelium in experimental atherosclerosis
Authors: Kim YongTae , Lobatto Mark E. , Kawahara Tomohiro , Lee Chung Bomy , Mieszawska Aneta J. , Sanchez-Gaytan Brenda L. , Fay Francois , Senders Max L. , Calcagno Claudia , Becraft Jacob , Tun Saung May , Gordon Ronald E. , Stroes Erik S. G. , Ma Mingming , Farokhzad Omid C. , Fayad Zahi A. , Mulder Willem J. M. , Langer Robert
Published: January 2014

Significance

This study shows that an endothelialized microfluidic chip with controllable permeability can serve as a model for nanoparticle translocation across the permeable endothelium. Integration of this in vitro model and an in vivo rabbit model revealed that the extravasation of nanoparticles across the endothelium in atherosclerotic plaques depends on microvascular permeability. This approach represents a unique method for the assessment of nanoparticle behavior across the atherosclerotic endothelium, and may also serve as a valuable tool to study nanomedicine accumulation in a variety of other diseases.
Preclinical efficacy of growth hormone-releasing hormone antagonists for androgen-dependent and castration-resistant human prostate cancer
Authors: Fahrenholtz Cale D. , Rick Ferenc G. , Garcia Maria I. , Zarandi Marta , Cai Ren-Zhi , Block Norman L. , Schally Andrew V. , Burnstein Kerry L.
Published: January 2014

Significance

Therapeutic options for recurrent castration-resistant prostate cancer (CRPC) are limited and more effective treatment regimens are needed. Antagonists of growth hormone-releasing hormone (GHRH) inhibit growth of experimental models of human cancer cells, including prostate cancer, by suppressing the actions of tumoral growth factors, particularly GHRH itself, which is an autocrine/paracrine growth factor in many tumors. Here we investigated the antitumor effects of the latest series of highly potent GHRH antagonists—MIA-602, MIA-606, and MIA-690—on androgen-dependent as well as CRPC lines expressing receptors for GHRH. MIA-602 inhibited in vivo growth of both androgen-dependent and CRPCs and decreased cell proliferation in vitro. This study provides evidence of the preclinical efficacy of GHRH antagonist MIA-602 in the treatment of human prostate cancer.
Size-dependent ultrafast structural dynamics inside phospholipid vesicle bilayers measured with 2D IR vibrational echoes
Authors: Kel Oksana , Tamimi Amr , Fayer Michael D.
Published: January 2014

Significance

Plasma membranes hold a wide variety of proteins and other biomolecules that are essential to cell functions. In addition, membranes are the solvent bath, which is intimately coupled to transmembrane processes. Membranes are frequently modeled using planar phospholipid bilayers and vesicles. However, vesicles are small and have relatively small radii of curvature. Research has shown that the bilayer curvature influences structural and thermodynamic properties, but much less is known about the interior dynamics of model membranes. Here we address ultrafast structural dynamics inside vesicle and planar bilayers using 2D IR vibrational echo experiments. The results show that the interior dynamics depend on the phospholipid chain length and are curvature dependent, with the dynamics becoming faster as the vesicle size decreases.
Drug Control in Afghanistan: Culture, Politics, and Power during the 1958 Prohibition of Opium in Badakhshan
Authors: Bradford James
Published: January 2014

This article explores the process leading to the Afghan government's decision to implement a prohibition and eradication of opium in the northeastern province of Badakhshan. It explores why Daud chose Badakhshan, the impact of the opium ban on the people of Badakhshan and the future of opium production and trade, as well as the evolution of drug control in Afghanistan under the Musahiban dynasty. Ultimately, the ban was launched because it allowed Daud to garner international praise and financial support, while enforcing eradication in an area inhabited by ethnic minorities ensured that the Afghan government's coercive strategy would not generate resistance from rural Pashtun tribes historically opposed to these types of state intervention.
Gene-culture co-evolution: teaching, learning, and correlations between relatives
Authors: Feldman Marcus W. , Christiansen Freddy B. , Otto Sarah P.
Published: January 2014

Heritability, the fraction of phenotypic variance attributable to the action of genes, is usually derived from a linear statistical partition of variance. In this paper we study a dichotomous phenotype whose transmission from parents to offspring depends on the parents’ phenotypes and the offspring’s genotype. Each individual is then represented as a phenogenotype. We derive expressions for each component of phenotypic variance and for covariances between relatives of various degrees. The resulting heritability estimates vary with the rates of phenotypic transmission as well as with the genetic contribution to the phenotype. Assortative mating by phenotype in parents is also shown to contribute to the correlations between relatives. In addition, we show that the frequency of alleles at genes affecting the phenotypes strongly affects standard heritability measures. This is important because for most complex traits these allele frequencies cannot be ascertained.
A theory of supply-driven evolution for cultural evolution
Authors: Xue Julian Z.
Published: January 2014

A process akin to biological evolution is one of the most promising candidates today for producing a general theory of cultural evolution. Current understanding of this process focuses on both drift as well as the selection of cultural variation as the primary vehicles of cultural change. Here, I show that natural selection can produce cultural change in the direction of the generation of cultural variation. I show how this mechanism can result in long-term cultural trends and how it adds to known mechanisms. I present examples to show how this theory is compatible with documented cultural and historical change.
Why Matter Occupies so Large a Volume?
Authors: Manoukian E.B.
Published: January 2014

The paper represents a rigorous treatment of the underlying quantum theory, not just in words but providing the underlying technical details, as to why matter occupies so large a volume and its intimate connection with the Pauli exclusion principle, as more and more matter is put together, as well as of the contraction or shrinkage of “bosonic matter”, upon collapse, for which the Pauli exclusion is abolished. From the derived explicit bounds of integrals of powers of the particle number densities, explicit bounds on probabilities of the occurrences of the events just described are extracted. These probabilities lead one to infer the change of the “size” or extension of such matter, upon expansion or contraction, respectively, as their content is increased.
Localized States of an Excess Electron in an Ionic Cluster
Authors: Grigorishin K.V. , Lev B.I.
Published: January 2014

A theory of an electron affinity for an ionic cluster is proposed both in a quasiclassical approach and with quantization of a polarization electric field in a nanoparticle. A critical size of the cluster regarding in formation of an electron's autolocalized state, dependencies of energy and radius of a polaron on a cluster's size are obtained by a variational method. It has been found that binding energy of the electron in the cluster depends on a cluster's radius but a radius of electron's auto-localization does not depend on the cluster's radius and it equals to the polaron radius in a corresponding infinity crystal. A bound state of the electron in a cluster is possible only if the cluster's radius is more than the polaron radius.
Is recovery of northern cod limited by poor feeding? The capelin hypothesis revisited
Authors: Mullowney Darrell R. J. , Rose George A.
Published: January 2014

The slow recovery of the “northern” Atlantic cod (Gadus morhua) stock off Newfoundland and Labrador has been ascribed to many factors. One hypothesis is poor feeding and condition as a consequence of a decline in capelin (Mallotus villosus), their former main prey. We compared the growth and condition of cod from known inshore (Smith Sound) and offshore (Bonavista Corridor) centres of rebuilding in wild subjects versus captive subjects fed an unlimited diet of oily rich fish. Wild fish in these areas have had different diets and population performance trends since stock declines in the early 1990s. Captive cod from both areas grew at the same rates and achieved equivalent prime condition, while their wild counterparts differed, with smaller sizes, lower condition in small fish, and elevated mortality levels in the offshore centre. Environmental temperature conditions did not account for the differences in performance of wild fish. Our results suggest that fish growth and condition, and hence rebuilding in the formerly large offshore spawning components of the northern cod, have been limited by a lack of capelin in their diet. Furthermore, we suggest that these groups are unlikely to rebuild until a recovery in capelin occurs.
Multiple-binding-site mechanism explains concentration-dependent unbinding rates of DNA-binding proteins
Authors: Sing Charles E. , Olvera de la Cruz Monica , Marko John F.
Published: January 2014

Recent work has demonstrated concentration-dependent unbinding rates of proteins from DNA, using fluorescence visualization of the bacterial nucleoid protein Fis [Graham et al. (2011) (Concentration-dependent exchange accelerates turnover of proteins bound to double-stranded DNA. Nucleic Acids Res., 39:2249)]. The physical origin of this concentration-dependence is unexplained. We use a combination of coarse-grained simulation and theory to demonstrate that this behavior can be explained by taking into account the dimeric nature of the protein, which permits partial dissociation and exchange with other proteins in solution. Concentration-dependent unbinding is generated by this simple model, quantitatively explaining experimental data. This effect is likely to play a major role in determining binding lifetimes of proteins in vivo where there are very high concentrations of solvated molecules.
Characteristics of Vegetable‐Based Twin‐Screw Extruded Yellow Perch (Perca flavescens) Diets Containing Fermented High‐Protein Soybean Meal and Graded Levels of Distillers Dried Grains with Solubles
Authors: Fallahi Parisa , Rosentrater Kurt A. , Muthukumarappan Kasiviswanathan , Brown Michael L.
Published: January 2014

A twin‐screw extrusion study was performed in replicated trials to produce vegetable‐based feeds for juvenile yellow perch. Two isocaloric (3.06 kcal/g) experimental diets were balanced to contain 20 and 40% distillers dried grains with solubles (DDGS) and a constant amount (20%) of fermented high‐protein soybean meal (PepSoyGen) as the fishmeal protein replacers; crude protein content was targeted at 40%. A fishmeal‐based diet was used as a control. Extrusion conditions included conditioner steam (0.11–0.16 kg/min), extruder water (0.11–0.19 kg/min), and screw speed (230–300 rpm). Increasing DDGS from 0 to 40% led to a considerable rise in bulk density, lightness L*), yellowness (b*), and unit density but to decreases in water activity (aw) and expansion ratio by 12.6, 14.4, 23, 21, 31, and 13%, respectively. The lowest unit density of 791.6 kg/m3 and highest bulk density of 654.5 kg/m3 were achieved with diets containing 20 and 40% DDGS, respectively; changes in DDGS content did not affect extrudate moisture, absorption index, or thermal properties. Raising DDGS from 0 to 40% resulted in an increase in water solubility and redness (a*) by 13.4 and 35%, respectively. All extrudates had high durability (>98%), and low aw of less than 0.5. Overall, this study yielded viable feeds for yellow perch.
Looking and homing: how displaced ants decide where to go
Authors: Zeil Jochen , Narendra Ajay , Stürzl Wolfgang
Published: January 2014

We caught solitary foragers of the Australian Jack Jumper ant,Myrmecia croslandi, and released them in three compass directions at distances of 10 and 15 m from the nest at locations they have never been before. We recorded the head orientation and the movements of ants within a radius of 20 cm from the release point and, in some cases, tracked their subsequent paths with a differential GPS. We find that upon surfacing from their transport vials onto a release platform, most ants move into the home direction after looking around briefly. The ants use a systematic scanning procedure, consisting of saccadic head and body rotations that sweep gaze across the scene with an average angular velocity of 90° s−1and intermittent changes in turning direction. By mapping the ants’ gaze directions onto the local panorama, we find that neither the ants’ gaze nor their decisions to change turning direction are clearly associated with salient or significant features in the scene. Instead, the ants look most frequently in the home direction and start walking fast when doing so. Displaced ants can thus identify home direction with little translation, but exclusively through rotational scanning. We discuss the navigational information content of the ants’ habitat and how the insects’ behaviour informs us about how they may acquire and retrieve that information.
Honeybee navigation: critically examining the role of the polarization compass
Authors: Evangelista C. , Kraft P. , Dacke M. , Labhart T. , Srinivasan M. V.
Published: January 2014

Although it is widely accepted that honeybees use the polarized-light pattern of the sky as a compass for navigation, there is little direct evidence that this information is actually sensed during flight. Here, we ask whether flying bees can obtain compass cues derived purely from polarized light, and communicate this information to their nest-mates through the ‘waggle dance’. Bees, from an observation hive with vertically oriented honeycombs, were trained to fly to a food source at the end of a tunnel, which provided overhead illumination that was polarized either parallel to the axis of the tunnel, or perpendicular to it. When the illumination was transversely polarized, bees danced in a predominantly vertical direction with waggles occurring equally frequently in the upward or the downward direction. They were thus using the polarized-light information to signal the two possible directions in which they could have flown in natural outdoor flight: either directly towards the sun, or directly away from it. When the illumination was axially polarized, the bees danced in a predominantly horizontal direction with waggles directed either to the left or the right, indicating that they could have flown in an azimuthal direction that was 90° to the right or to the left of the sun, respectively. When the first half of the tunnel provided axial illumination and the second half transverse illumination, bees danced along all of the four principal diagonal directions, which represent four equally likely locations of the food source based on the polarized-light information that they had acquired during their journey. We conclude that flying bees are capable of obtaining and signalling compass information that is derived purely from polarized light. Furthermore, they deal with the directional ambiguity that is inherent in polarized light by signalling all of the possible locations of the food source in their dances, thus maximizing the chances of recruitment to it.
Intron-Mediated Alternative Splicing of WOOD-ASSOCIATED NAC TRANSCRIPTION FACTOR1B Regulates Cell Wall Thickening during Fiber Development in Populus Species
Authors: Zhao Yunjun , Sun Jiayan , Xu Peng , Zhang Rui , Li Laigeng
Published: January 2014

Alternative splicing is an important mechanism involved in regulating the development of multicellular organisms. Although many genes in plants undergo alternative splicing, little is understood of its significance in regulating plant growth and development. In this study, alternative splicing of black cottonwood (Populus trichocarpa) wood-associated NAC domain transcription factor (PtrWNDs), PtrWND1B, is shown to occur exclusively in secondary xylem fiber cells. PtrWND1B is expressed with a normal short-transcript PtrWND1B-s as well as its alternative long-transcript PtrWND1B-l. The intron 2 structure of the PtrWND1B gene was identified as a critical sequence that causes PtrWND1B alternative splicing. Suppression of PtrWND1B expression specifically inhibited fiber cell wall thickening. The two PtrWND1B isoforms play antagonistic roles in regulating cell wall thickening during fiber cell differentiation in Populus spp. PtrWND1B-s overexpression enhanced fiber cell wall thickening, while overexpression of PtrWND1B-l repressed fiber cell wall thickening. Alternative splicing may enable more specific regulation of processes such as fiber cell wall thickening during wood formation.
Cross-sectoral comparison of concessions in transport
Authors: Vanelslander Thierry , Chomat Gilles , Roumboutsos Athena , Bonnet Géraldine
Published: January 2014

Purpose

– The purpose of this paper is to present a methodology of comparing concession projects developed in different transport sub-sectors. The methodology is tested in the comparison of three different cases, each of which represent a particular mode of transport: a road development project, a city tramway project and a port lock construction initiative.

Design/methodology/approach

– A fuzzy logic approach methodology is applied in carrying out the comparison between cases. Granulation is achieved by employing a Contextual (Ws) Risk Analysis Framework, as risks constitute the basis to public private partnership (PPP) structure. Linguistic variables are then used to describe the comparative findings.

Findings

– The methodology presented allows for the comparison of three cases from different transport sub-sectors. Identification of similarities provides the potential to transfer experience from one sector to the other. With respect to the three cases studied, it was identified that traffic risk seems to be passed on to the private operators in relation to the level of exclusivity. Finally, PPP projects initiated by central government (as opposed to those initiated by local governments) seem to be more finance-driven than service-driven.

Research limitations/implications

– As the number of cases to be compared increases, quantitative comparative analysis fuzzy set values can be included in order to carry out a full analysis. The present approach should be considered introductory, as fuzzy sets are not generated due to the limited number of surveys (cases) compared (hence the term “pre-fuzzy”).

Practical implications

– The methodology presented and the cases tested indicate the possibility for knowledge/experience transfer and the transferability of best practices.

Originality/value

– Cross-sub-sectoral comparisons for transport PPP projects have not been identified in literature.