bluuebunny/crossref_metadata_2025 huggingface dataset:
The temperature dependence of methane dissociation on Ni(111) and Pt(111): Mixed quantum-classical studies of the lattice response
Authors: Tiwari Ashwani Kumar , Nave Sven , Jackson Bret
Published: April 2010

The barrier to the dissociative adsorption of methane on metal surfaces is generally large, and its height can vary with the motion of the lattice atoms. One fully quantum and three different mixed quantum-classical approaches are used to examine this reaction on Ni(111) and Pt(111) surfaces, using potential energy surfaces derived from density functional theory. The three approximate methods are benchmarked against the exact quantum studies, and two of them are shown to work reasonably well. The mixed models, which treat the lattice motion classically, are used to examine the lattice response during the reaction. It is found that the thermal motion of the lattice atoms strongly modifies the reactivity, but that their motion is not significantly perturbed. Based on these results, new models for methane reactions are proposed based on a sudden treatment of the lattice motion and shown to agree well with the exact results. In these new models, the reaction probability at different surface temperatures is computed from static surface reaction probabilities, allowing for a quantum calculation of the reaction probability without having to explicitly treat the motion of the heavy lattice atoms.
m
-plane (101̱0) InN heteroepitaxied on (100)-γ-LiAlO2 substrate: Growth orientation control and characterization of structural and optical anisotropy
Authors: Hsiao Ching-Lien , Chen Jr-Tai , Hsu Hsu-Cheng , Liao Ying-Chieh , Tseng Po-Han , Chen Yen-Ting , Feng Zhe Chuan , Tu Li-Wei , Chou Mitch M. C. , Chen Li-Chyong , Chen Kuei-Hsien
Published: April 2010

Heteroepitaxial growth of m-plane (101̱0) InN film on (100)-γ-LiAlO2 (LAO) substrate has been realized by plasma-assisted molecular-beam epitaxy. Surface treatment of LAO substrate plays an important role in controlling the resultant phase and purity of m-plane InN. X-ray diffraction, reflection high-energy electron diffraction, electron back scatter diffraction, and transmission electron microscopy (TEM) studies revealed formation of pure m-plane InN film using substrate preannealed at 800 °C but without any nitridation. In contrast, using substrate with nitridation but otherwise identical pretreatment and growth conditions, c-plane (0001) InN columnar structure was grown, instead of m-plane InN film. Structural anisotropy of the m-plane InN epitaxied on LAO is attributed to the I1 type base-plane stacking faults according to the modified Williamson–Hall and TEM analyses. A rectangular-to-rectangular atomic stacking sequence and a commensurately lattice-matched condition in epitaxial direction of [12̱10]InN∥[001]LAO with a small misfit strain of ∼0.2% are proposed to realize this heteroepitaxy. Angle-dependent polarized UV-Raman spectra showed that all the InN phonon modes follow Raman selection rule well. Strong polarization anisotropy of photoluminescence (PL) emission located at ∼0.63 eV was observed, as evidenced by a high polarization degree of 87% of the m-plane InN determined by infrared polarized PL spectroscopy.
Properties of obliquely incident electromagnetic wave in one-dimensional magnetized plasma photonic crystals
Authors: Qi Limei , Yang Ziqiang , Lan Feng , Gao Xi , Shi Zongjun
Published: April 2010

Properties of obliquely incident electromagnetic wave in one-dimensional (1D) magnetized plasma photonic crystals (PPCs) are studied in this paper. Based on the continuous boundary condition of electromagnetic wave in 1D PPC, transfer matrix equation and dispersion equation of transverse magnetic polarization are deduced, and the properties of dispersion and transmission relation in terms of external magnetic field, collision frequency, and dielectric constant of dielectric and incident angles are investigated, respectively. Results show that gap location and gap width can be effectively controlled by adjusting external magnetic field as well as incident angle, and increasing collision frequency has little effect on gap width while larger dielectric constant of dielectric leads to more gaps.
Inertial measurement with trapped particles: A microdynamical system
Authors: Post E. Rehmi , Popescu George A. , Gershenfeld Neil
Published: April 2010

We describe an inertial measurement device based on an electrodynamically trapped proof mass. Mechanical constraints are replaced by guiding fields, permitting the trap stiffness to be tuned dynamically. Optical readout of the proof mass motion provides a measurement of acceleration and rotation, resulting in an integrated six degree of freedom inertial measurement device. We demonstrate such a device—constructed without microfabrication—with sensitivity comparable to that of commercial microelectromechanical systems technology and show how trapping parameters may be adjusted to increase dynamic range.
Circularly and elliptically polarized near-field radiation from nanoscale subwavelength apertures
Authors: Öğüt Erdem , Şendur Kürşat
Published: April 2010

With advances in nanotechnology, obtaining circularly and elliptically polarized optical spots beyond the diffraction limit is an emerging need for plasmonic applications. Two techniques are suggested to obtain circularly and elliptically polarized near-field radiation using subwavelength apertures. It is demonstrated that a square aperture can mediate diffraction limited circularly or elliptically polarized radiation into an optical spot with circular or elliptical polarization beyond the diffraction limit. Linearly polarized diffraction limited radiation is converted into a circularly or an elliptically polarized optical spot beyond the diffraction limit by creating asymmetry in the subwavelength aperture.
Density functional theoretical study of pentacene/noble metal interfaces with van der Waals corrections: Vacuum level shifts and electronic structures
Authors: Toyoda Kenji , Hamada Ikutaro , Lee Kyuho , Yanagisawa Susumu , Morikawa Yoshitada
Published: April 2010

In order to clarify factors determining the interface dipole, we have studied the electronic structures of pentacene adsorbed on Cu(111), Ag(111), and Au(111) by using first-principles density functional theoretical calculations. In the structural optimization, a semiempirical van der Waals (vdW) approach [S. Grimme, J. Comput. Chem. 27, 1787 (2006)] is employed to include long-range vdW interactions and is shown to reproduce pentacene-metal distances quite accurately. The pentacene-metal distances for Cu, Ag, and Au are evaluated to be 0.24, 0.29, and 0.32 nm, respectively, and work function changes calculated by using the theoretically optimized adsorption geometries are in good agreement with the experimental values, indicating the validity of the present approach in the prediction of the interface dipole at metal/organic interfaces. We examined systematically how the geometric factors, especially the pentacene-substrate distance (ZC), and the electronic properties of the metal substrates contribute to the interface dipole. We found that at ZC≥0.35 nm, the work function changes (Δϕ’s) do not depend on the substrate work function (ϕm), indicating that the interface level alignment is nearly in the Schottky limit, whereas at ZC≤0.25 nm, Δϕ’s vary nearly linearly with ϕm, and the interface level alignment is in the Bardeen limit. Our results indicate the importance of both the geometric and the electronic factors in predicting the interface dipoles. The calculated electronic structure shows that on Au, the long-range vdW interaction dominates the pentacene-substrate interaction, whereas on Cu and Ag, the chemical hybridization contributes to the interaction.
Phase stabilization of a wave-front dividing four-beam combined amplifier with stimulated Brillouin scattering phase conjugate mirrors
Authors: Shin Jae Sung , Park Sangwoo , Kong Hong Jin , Yoon Jin Woo
Published: April 2010

Beam combining method is a promising technique for achieving energy scaling of solid-state lasers. The key technique of the coherent beam combining is the phase control of the stimulated Brillouin scattering wave. In previous works, the amplitude dividing scheme has shown more effective phase control than the wave-front dividing scheme. A recent experiment demonstrated that the phase stabilization in the wave-front dividing scheme can be improved by reducing the beam pointing fluctuation. In this work, a phase stabilization experiment is performed with the wave-front dividing four-beam combined amplifier. The phases are stabilized within λ/25 with an amplified gain of 5.25.
Characterization and modeling of a terahertz photoconductive switch
Authors: Suen J. Y. , Li W. , Taylor Z. D. , Brown E. R.
Published: April 2010

We examine the terahertz (THz) performance of an ErAs:GaAs photoconductive switch under varying bias conditions and optical drive power. Despite THz power up to 287 μW, saturation effects were not seen. In addition, the THz power spectra were measured with a Fourier transform infrared spectrometer, and the roll-off was found to be invariant to bias voltage and consistent with a THz pulsewidth of 1.59 ps and a peak power of 3.1 W. These results are confirmed by a large-signal, high-frequency circuit model that suggests that further increase in THz power and efficiency are possible through an increase in the mode-locked laser power and reduction in its pulse width. The model is useful in designing both the laser and photoconductive switches to maximize available power and efficiency.
High-resolution two-dimensional correlation spectroscopy in inhomogeneous fields: New application of intermolecular zero-quantum coherences
Authors: Huang Yuqing , Chen Xi , Cai Shuhui , Cai Congbo , Chen Zhong
Published: April 2010

A new pulse sequence is proposed based on intermolecular zero-quantum coherences (iZQCs) to obtain high-resolution two-dimensional (2D) correlation spectroscopy (COSY) in inhomogeneous fields via three-dimensional (3D) acquisition. This sequence extends the high-resolution iZQC approaches from one dimension to two dimensions. Since the iZQC evolution periods in the new sequence are insensitive to the field inhomogeneities, high-resolution COSY spectra can be recovered from inhomogeneous fields by projecting the 3D data onto the indirectly acquired 2D plane. Theoretical expressions were derived according to the distant dipolar field treatment combined with product operator formalism. Both the experimental observations and computer simulations are consistent with the theoretical predictions. The new sequence thus provides an attractive way to eliminate the influences of field inhomogeneity on the conventional COSY methods, which may be useful for the study of chemical and biological materials.
Voltage-induced incandescent light emission from large-area graphene films
Authors: Yu Dingshan , Dai Liming
Published: April 2010

Voltage-induced incandescent light emission from large-area graphene films was demonstrated. Stable, bright, and uniform incandescent emission with a low turn-on voltage (∼6 V) was obtained for a free-standing graphene film (0.5×1 cm2) under appropriate vacuum (0.05 Torr) or Ar protection. The emission spectra fit well to the blackbody emission model with the emission intensity being exponentially proportional to the external voltage and inversely proportional to the gas pressure. Our results indicate great promise of graphene-based incandescent emitters for flat-lighting applications.
Wide memory window in graphene oxide charge storage nodes
Authors: Wang Shuai , Pu Jing , Chan Daniel S. H. , Cho Byung Jin , Loh Kian Ping
Published: April 2010

Solution-processable, isolated graphene oxide (GO) monolayers have been used as a charge trapping dielectric in TaN gate/Al2O3/isolated GO sheets/SiO2/p-Si memory device (TANOS). The TANOS type structure serves as memory device with the threshold voltage controlled by the amount of charge trapped in the GO sheet. Capacitance-Voltage hysteresis curves reveal a 7.5 V memory window using the sweep voltage of −5–14 V. Thermal reduction in the GO to graphene reduces the memory window to 1.4 V. The unique charge trapping properties of GO points to the potential applications in flexible organic memory devices.
Thermodynamic properties of normal and deuterated naphthalenes
Authors: Chen S. S. , Kudchadker S. A. , Wilhoit R. C.
Published: April 2010

Structural and spectroscopic data and the standard enthalpy of formation 298.15 K for C10H8, α-C10H1D4, β-C10H4D4 and C10D8 were reviewed. The selected values were utilized to calculate the ideal gas thermodynamic properties in the temperature range 0 to 1500 K, using the rigid rotor and harmonic oscillator model. The comparison between the third law entropies and the spectroscopically calculated entropies of C10H8 was studied. The agreement is satisfactory within the experimental uncertainties.
Daniel Klionsky: A full plate for autophagy
Authors: Short Ben
Published: April 2010

Klionsky proves that those who can, teach as well as do.
Cross talk between microRNA and epigenetic regulation in adult neurogenesis
Authors: Szulwach Keith E. , Li Xuekun , Smrt Richard D. , Li Yujing , Luo Yuping , Lin Li , Santistevan Nicholas J. , Li Wendi , Zhao Xinyu , Jin Peng
Published: April 2010

Both microRNAs (miRNAs) and epigenetic regulation have important functions in stem cell biology, although the interactions between these two pathways are not well understood. Here, we show that MeCP2, a DNA methyl-CpG–binding protein, can epigenetically regulate specific miRNAs in adult neural stem cells (aNSCs). MeCP2-mediated epigenetic regulation of one such miRNA, miR-137, involves coregulation by Sox2, a core transcription factor in stem cells. miR-137 modulates the proliferation and differentiation of aNSCs in vitro and in vivo. Overexpression of miR-137 promotes the proliferation of aNSCs, whereas a reduction of miR-137 enhances aNSC differentiation. We further show that miR-137 post-transcriptionally represses the expression of Ezh2, a histone methyltransferase and Polycomb group (PcG) protein. The miR-137–mediated repression of Ezh2 feeds back to chromatin, resulting in a global decrease in histone H3 trimethyl lysine 27. Coexpression of Ezh2 can rescue phenotypes associated with miR-137 overexpression. These results demonstrate that cross talk between miRNA and epigenetic regulation contributes to the modulation of adult neurogenesis.
A dual function for chaperones SSB–RAC and the NAC nascent polypeptide–associated complex on ribosomes
Authors: Koplin Ansgar , Preissler Steffen , Ilina Yulia , Koch Miriam , Scior Annika , Erhardt Marc , Deuerling Elke
Published: April 2010

The yeast Hsp70/40 system SSB–RAC (stress 70 B–ribosome-associated complex) binds to ribosomes and contacts nascent polypeptides to assist cotranslational folding. In this study, we demonstrate that nascent polypeptide–associated complex (NAC), another ribosome-tethered system, is functionally connected to SSB–RAC and the cytosolic Hsp70 network. Simultaneous deletions of genes encoding NAC and SSB caused conditional loss of cell viability under protein-folding stress conditions. Furthermore, NAC mutations revealed genetic interaction with a deletion of Sse1, a nucleotide exchange factor regulating the cytosolic Hsp70 network. Cells lacking SSB or Sse1 showed protein aggregation, which is enhanced by additional loss of NAC; however, these mutants differ in their potential client repertoire. Aggregation of ribosomal proteins and biogenesis factors accompanied by a pronounced deficiency in ribosomal particles and translating ribosomes only occurs in ssbΔ and nacΔssbΔ cells, suggesting that SSB and NAC control ribosome biogenesis. Thus, SSB–RAC and NAC assist protein folding and likewise have important functions for regulation of ribosome levels. These findings emphasize the concept that ribosome production is coordinated with the protein-folding capacity of ribosome-associated chaperones.
The Rvi15 (Vr2) Apple Scab Resistance Locus Contains Three TIR-NBS-LRR Genes
Authors: Galli Paolo , Patocchi Andrea , Broggini Giovanni Antonio Lodovico , Gessler Cesare
Published: April 2010

Scab caused by the pathogen Venturia inaequalis is considered the most important fungal disease of cultivated apple (Malus × domestica Borkh.). In all, 16 monogenic resistances against scab have been found in different Malus spp. and some of them are currently used in apple breeding for scab-resistant cultivars. However, the self incompatibility and the long generation time of Malus spp. together with the high standards of fruit quality demanded from the fresh market render the breeding of high-quality cultivars in apple a long and expensive task. Therefore, the cloning of disease resistance genes and the use of the cloned genes for the transformation of high-quality apple cultivars could be an approach to solve these drawbacks. We report the construction of a bacterial artificial chromosome (BAC) contig spanning the Rvi15 (Vr2) apple scab resistance locus using two GMAL 2473 BAC libraries. A single BAC clone of the contig was sufficient to span the resistance locus. The BAC clone was completely sequenced, allowing identification of a sequence of 48.6 kb going from the two closest markers (ARGH17 and 77G20RP) bracketing Rvi15 (Vr2). Analysis of the 48.6-kb sequence revealed the presence of three putative genes characterized by a Toll and mammalian interleukin-1 receptor protein nucleotide-binding site leucine-rich repeat structure. All three genes were found to be transcribed.
PAD4-Dependent Antibiosis Contributes to thessi2-Conferred Hyper-Resistance to the Green Peach Aphid
Authors: Louis Joe , Leung Queena , Pegadaraju Venkatramana , Reese John , Shah Jyoti
Published: April 2010

Myzus persicae, commonly known as green peach aphid (GPA), is a sap-sucking insect with a broad host range. Arabidopsis thaliana responds to GPA infestation with elevated expression of the PHYTOALEXIN DEFICIENT4 (PAD4) gene. Previously, we had demonstrated that the loss of PAD4 gene function compromises Arabidopsis resistance to GPA. In contrast, a mutation in the Arabidopsis SUPPRESSOR OF SALICYLIC ACID INSENSITIVITY2 (SSI2) gene, which encodes a desaturase involved in lipid metabolism, resulted in hyper-resistance to GPA. We demonstrate here that PAD4 is required for the ssi2-dependent heightened resistance to GPA. Based on electrical monitoring of insect behavior and bioassays in which the insect was given a choice between the wild type and the ssi2 mutant, it is concluded that the ssi2-conferred resistance is not due to deterrence of insect settling or feeding from the phloem of the mutant. Instead, hyper-resistance in the ssi2 mutant results from heightened antibiosis that curtails insect reproduction. Petiole exudates collected from uninfested ssi2 plants contain elevated levels of an activity that interferes with aphid reproduction in synthetic diets. PAD4 was required for the accumulation of this antibiotic activity in petiole exudates, supporting the role of PAD4 in phloem-based resistance. Because PAD4 expression is not elevated in the ssi2 mutant, we suggest that basal PAD4 expression contributes to this antibiosis.
Production of Nitric Oxide and Nitrosylleghemoglobin Complexes in Soybean Nodules in Response to Flooding
Authors: Sánchez Cristina , Gates Andrew J. , Meakin Georgina E. , Uchiumi Toshiki , Girard Lourdes , Richardson David J. , Bedmar Eulogio J. , Delgado María J.
Published: April 2010

Nitric oxide (NO) has gained interest as a major signaling molecule during plant development and in response to environmental cues. Formation of NO during symbiotic interactions has been reported, but the role and sources of NO in nodules remain unclear. In this work, the involvement of denitrification, performed by the symbiont Bradyrhizobium japonicum, in NO formation in soybean nodules in response to flooding conditions has been investigated by inoculating plants with napA-, nirK-, or norC-deficient mutants. Levels of nitrosylleghemoglobin (LbNO) in flooded nirK and norC nodules were significantly higher than those observed in wild-type nodules. In addition, nirK and norC nodules accumulated more nitrite and NO, respectively, than wild-type nodules. By contrast, levels of LbNO, nitrite, and NO in flooded napA nodules were lower than in wild-type nodules. These results suggest that LbNO formation in soybean nodules in response to flooding conditions is caused by nitrite and NO generated from periplasmic nitrate reductase (Nap) and also containing nitrite reductase (NirK) denitrification enzymes. Flooding caused a decrease of nifH expression and nitrogenase activity in wild-type and norC nodules but not in napA or nirK nodules. Incubation of wild-type and norC nodules with a NO scavenger counteracted the effect of flooding. Under free-living conditions, β-galactosidase activity from a nifD′-′lacZ fusion decreased in a norC mutant, which also accumulated NO in the medium. These results suggest that NO formed by Cu-containing nitrite reductase in soybean nodules in response to flooding has a negative effect on expression of nitrogenase. We propose that Lb has a major role in detoxifying NO and nitrite produced by bacteroidal denitrification in response to flooding conditions.
Short-term couplings of the cardiovascular system in pregnant women suffering from pre-eclampsia
Authors: Riedl Maik , Suhrbier Alexander , Stepan Holger , Kurths Jürgen , Wessel Niels
Published: April 2010

Pre-eclampsia (PE), a serious pregnancy-specific disorder, causes significant neonatal and maternal morbidity and mortality. Recent studies showed that cardiovascular variability parameters as well as the baroreflex sensitivity remarkably improve its early diagnosis. For a better understanding of the dynamical changes caused by PE, in this study the coupling between respiration, systolic and diastolic blood pressure, and heart rate is investigated. Thirteen datasets of healthy pregnant women and 10 of subjects suffering from PE are included. Nonlinear additive autoregressive models with external input are used for a model-based coupling analysis following the idea of Granger causality. To overcome the problem of misdetections of standard methods in systems with a dominant driver, a heuristic ensemble approach is used here. A coupling is assumed to be real when existent in more than 80 per cent of the ensemble members, and otherwise denoted as artefacts. As the main result, we found that the coupling structure between heart rate, systolic blood pressure, diastolic blood pressure and respiration for healthy subjects and PE patients is the same and reliable. As a pathological mechanism, however, a significant increased respiratory influence on the diastolic blood pressure could be found for PE patients (
p
=0.003). Moreover, the nonlinear form of the respiratory influence on the heart rate is significantly different between the two groups (
p
=0.002). Interestingly, the influence of systolic blood pressure on the heart rate is not selected, which indicates that the baroreflex sensitivity estimation strongly demands the consideration of causal relationships between heart rate, blood pressure and respiration. Finally, our results point to a potential role of respiration for understanding the pathogenesis of PE.
Optimality approaches to describe characteristic fluvial patterns on landscapes
Authors: Paik Kyungrock , Kumar Praveen
Published: April 2010

Mother Nature has left amazingly regular geomorphic patterns on the Earth's surface. These patterns are often explained as having arisen as a result of some optimal behaviour of natural processes. However, there is little agreement on what is being optimized. As a result, a number of alternatives have been proposed, often with little
a priori
justification with the argument that successful predictions will lend
a posteriori
support to the hypothesized optimality principle. Given that maximum entropy production is an optimality principle attempting to predict the microscopic behaviour from a macroscopic characterization, this paper provides a review of similar approaches with the goal of providing a comparison and contrast between them to enable synthesis. While assumptions of optimal behaviour approach a system from a macroscopic viewpoint, process-based formulations attempt to resolve the mechanistic details whose interactions lead to the system level functions. Using observed optimality trends may help simplify problem formulation at appropriate levels of scale of interest. However, for such an approach to be successful, we suggest that optimality approaches should be formulated at a broader level of environmental systems' viewpoint, i.e. incorporating the dynamic nature of environmental variables and complex feedback mechanisms between fluvial and non-fluvial processes.
Bacterial chemotaxis and entropy production
Authors: Županović Paško , Brumen Milan , Jagodič Marko , Juretić Davor
Published: April 2010

Entropy production is calculated for bacterial chemotaxis in the case of a migrating band of bacteria in a capillary tube. It is found that the speed of the migrating band is a decreasing function of the starting concentration of the metabolizable attractant. The experimentally found dependence of speed on the starting concentration of galactose, glucose and oxygen is fitted with power-law functions. It is found that the corresponding exponents lie within the theoretically predicted interval. The effect of the reproduction of bacteria on band speed is considered, too. The acceleration of the band is predicted due to the reproduction rate of bacteria. The relationship between chemotaxis, the maximum entropy production principle and the formation of self-organizing structure is discussed.
Predominance of an ST11 extended-spectrum β-lactamase-producing Klebsiella pneumoniae clone causing bacteraemia and urinary tract infections in Korea
Authors: Ko Kwan Soo , Lee Ji-Young , Baek Jin Yang , Suh Ji-Yoeun , Lee Mi Young , Choi Ji Young , Yeom Joon-Sup , Kim Yeon-Sook , Jung Sook-In , Shin Sang Yop , Heo Sang Taek , Kwon Ki Tae , Son Jun Seong , Kim Shin-Woo , Chang Hyun-Ha , Ki Hyun Kyun , Chung Doo Ryeon , Peck Kyong Ran , Song Jae-Hoon
Published: April 2010

To investigate the antimicrobial resistance, extended-spectrum β-lactamases (ESBLs) and clones of Klebsiella pneumoniae isolates causing bacteraemia or urinary tract infection (UTI) in Korea, a total of 406 K. pneumoniae isolates from patients with bacteraemia (221 isolates) and UTI (185 isolates) were collected from 10 tertiary-care Korean hospitals from July 2006 to October 2007. In vitro antimicrobial susceptibility testing was performed for all isolates and ESBL production was tested. Multilocus sequence typing (MLST) analyses were performed to characterize genotypes of ESBL-producing K. pneumoniae isolates. PFGE was performed for sequence type 11 (ST11) isolates. Forty-seven UTI isolates (25.4 %) produced ESBLs, while 30 bacteraemia isolates (13.6 %) produced ESBLs (P=0.002). Among 77 ESBL-producing isolates, thirty-two (41.6 %) produced SHV-type ESBLs. bla
CTX-M genes such as bla
CTX-M-14 and bla
CTX-M-15 were detected in 36.4 %. MLST and PFGE analyses showed that ST11 was dominant in ESBL-producing K. pneumoniae isolates causing UTI (57.4 %) and in those causing bacteraemia (70.0 %) and has been prevalent in Korean hospitals. ST11 isolates harbour a combination of different ESBL genes. The ST11 clone of ESBL-producing K. pneumoniae isolates prevails in Korea, but most isolates might acquire ESBL genes independently or several different clones might be distributed in Korea.
A Genetic Framework for Grain Size and Shape Variation in Wheat
Authors: Gegas Vasilis C. , Nazari Aida , Griffiths Simon , Simmonds James , Fish Lesley , Orford Simon , Sayers Liz , Doonan John H. , Snape John W.
Published: April 2010

Grain morphology in wheat (Triticum aestivum) has been selected and manipulated even in very early agrarian societies and remains a major breeding target. We undertook a large-scale quantitative analysis to determine the genetic basis of the phenotypic diversity in wheat grain morphology. A high-throughput method was used to capture grain size and shape variation in multiple mapping populations, elite varieties, and a broad collection of ancestral wheat species. This analysis reveals that grain size and shape are largely independent traits in both primitive wheat and in modern varieties. This phenotypic structure was retained across the mapping populations studied, suggesting that these traits are under the control of a limited number of discrete genetic components. We identified the underlying genes as quantitative trait loci that are distinct for grain size and shape and are largely shared between the different mapping populations. Moreover, our results show a significant reduction of phenotypic variation in grain shape in the modern germplasm pool compared with the ancestral wheat species, probably as a result of a relatively recent bottleneck. Therefore, this study provides the genetic underpinnings of an emerging phenotypic model where wheat domestication has transformed a long thin primitive grain to a wider and shorter modern grain.
Minimizing environmental impacts of grassland weed management: can Cirsium arvense be controlled without herbicides?
Authors: Pywell R. F. , Hayes M. J. , Tallowin J. B. , Walker K. J. , Meek W. R. , Carvell C. , Warman L. A. , Bullock J. M.
Published: April 2010

Invasion by undesirable plants, such as Cirsium arvense, can constrain attempts to conserve and restore biodiversity in extensively managed temperate grasslands, but control with herbicides can cause environmental harm. We contrasted herbicides with more environmentally sustainable weed control strategies. Six‐year, large‐scale randomized block experiments were established to determine optimum combinations of grazing management and mechanical or herbicide treatments to control thistles within lowland and upland grazing systems. Factorial combinations of tight vs. lenient grazing in spring and autumn with additional treatments of winter grazing were compared. Thistle control methods were applied in sub‐treatments for the first 2 years: cutting twice yearly, herbicide wiping, and cutting followed by herbicide application. Thistle abundance decreased under lenient grazing in spring, autumn and winter at the lowland site, under lenient spring and winter grazing in the uplands and under cattle compared with sheep grazing. Herbicide wiping was the most effective control measure and cutting the least, but effects of all weed control sub‐treatments were lost rapidly, so lenient grazing was sufficient to give long‐term thistle control. Lenient grazing and herbicide wiping also caused small declines in non‐target forb diversity. Control of creeping thistle can therefore be achieved without herbicides because lenient grazing in spring and autumn can decrease thistle populations to sufficiently low levels. Severe infestations can be more rapidly controlled using herbicides, but are better avoided at botanically diverse sites. Ecologically‐based weed control strategies have great potential, but require well designed field experiments, which run for sufficiently long periods to allow community‐level impacts to develop.
Fixed‐dose combination therapies in the management of hyperglycaemia in Type 2 diabetes: an opportunity to improve adherence and patient care
Authors: Schernthaner G.
Published: April 2010

Diabet. Med. 27, 739–743 (2010)

The medication‐taking behaviour of patients may be key to avoiding the serious long‐term micro‐ and macrovascular complications of Type 2 diabetes. However, the polypharmacy often required to achieve good metabolic control can be a significant barrier to adequate adherence. Reducing treatment complexity can be achieved through the use of single‐tablet fixed‐dose combinations of two oral hypoglycaemic agents. Studies to date suggest that this approach can significantly improve adherence over separate tablet dual therapy and has the potential to improve metabolic and clinical outcomes. A range of fixed‐dose combination oral hypoglycaemic agents in several different dosage strengths are available and the strategies for optimal implementation of these options continue to evolve. This article describes the extent and consequences of poor adherence to oral hypoglycaemic agents in Type 2 diabetes and discusses the potential contribution of fixed‐dose combinations to the provision of improved care.
Consumer Expenditures and Home Production at Retirement – New Evidence from Germany
Authors: Lührmann Melanie
Published: April 2010

This paper investigates consumer expenditures of German households pre- and post-retirement. The widely observed distinct drop in spending upon retirement entry poses an empirical puzzle since life cycle theory predicts smoothing of the marginal utility of consumption over time. As one explanation, I explore the role of home production as a substitute for consumer expenses. Taking a combined look at consumer expenditures and time use pre- and post-retirement, I find a significant drop of about 17% of pre-retirement expenses at retirement which coincides with an increase in time spent on home production of an additional 89 minutes per day, accounting for 21% of average home production.
Expression and signaling of novel IL15Rα splicing variants in cerebral endothelial cells of the blood‐brain barrier
Authors: Wu Xiaojun , Pan Weihong , Stone Kirsten P. , Zhang Yan , Hsuchou Hung , Kastin Abba J.
Published: April 2010

J. Neurochem. (2010) 114, 122–129.

Interleukin (IL)‐15 and its receptors in cerebral microvascular endothelial cells play an important role in mediating neuroinflammatory signaling across the blood‐brain barrier. Although alternative splice variants of IL15Rα (the specific receptor) are seen in immune cells, the presence and functions of splice variants have not been studied in the cerebral endothelia that compose the blood‐brain barrier. In this study, we identified five splice variants from mouse cerebral capillaries by RT‐PCR, cloning, and DNA sequencing, and performed domain analysis. Four of these isoforms have never been described in any tissue. All isoforms were detected by qPCR in enriched mouse cerebral microvessels and their expression was increased by tumor necrosis factor treatment in vivo. To determine their functions, plasmids encoding individual isoforms were transfected into RBE4 cerebral endothelial cells. All of these predicted alkalinic proteins were expressed and most showed post‐translational modifications. There were variations in their subcellular distribution. Only the full length IL15Rα and to a lesser degree isoform α1 were trafficked to the cell surface 24 h after over‐expression. As shown by a luciferase reporter for signal transducer and activator of transcription (STAT)‐3, over‐expression of isoforms α2 and α4 reduced basal STAT3 activation. In comparison with the control, over‐expression of the full length IL15Rα had a greater effect in increasing IL15‐induced STAT3 transactivation than other isoforms. The results show that IL15 signaling in cerebral endothelia is probably an orchestrated effect of all IL15Rα splice variants that determine the eventual outcome by differential regulation.
Communication as negotiation processes in long‐term physiotherapy: a qualitative study
Authors: Øien Aud Marie , Steihaug Sissel , Iversen Synnøve , Råheim Målfrid
Published: April 2010

Scand J Caring Sci; 2011; 25; 53–61
 
Communication as negotiation processes in long‐term physiotherapy: a qualitative study

Purpose:  The purpose of this study was to describe communicative patterns about change in demanding physiotherapy treatment situations.

Methods:  A multiple case study of eleven treatment courses was carried out, based on in‐depth individual interviews, focus group interview, personal notes and repeated video‐recordings. To compare communication within and over sessions, a two‐step procedure was applied: identification of communication patterns and detailed analysis of selected dialogues from video‐recorded sequences.

Findings:  One main communicative pattern was identified: Seeking for common ground – demanding negotiating process. This pattern was interrupted by short episodes of two types of challenges; the pattern of ambivalence and uncertainty, and the pattern of impatience and disagreement. Communication between the participants appeared as a demanding and complex process of negotiations during the treatment processes. The physiotherapists’ sensitivity of and ability to negotiate the tasks, the emotions related to tasks and the nature of the relationships, seemed to facilitate change. The patients’ and the physiotherapists’ capacity to bear and come through demanding situations created new ways of interaction.

Conclusion:  The demanding situations may generate a potential for the development and the improvement of treatment outcomes. Understanding such episodes as open and dynamic, in contrast to defining the patient as demanding, suggests a useful perspective for treatment.
Opioid Detoxification: From Controlled Clinical Trial to Clinical Practice
Authors: Dijkstra Boukje A. G. , De Jong Cor A. J. , Wensing Michel , Krabbe Paul F. M. , Van Der Staak Cees P. F.
Published: April 2010

Controlled clinical trials have high internal validity but suffer from difficulties in external validity. This study evaluates the generalizability of the results of a controlled clinical trial on rapid detoxification in the everyday clinical practice of two addiction treatment centers. The results show that rapid detoxification in everyday practice differs with regard to patient characteristics, enrolment, and completion rates (86.8% vs. 100%). However, abstinence rates after rapid detoxification in the controlled clinical trial (61.8%) were generalizable to everyday clinical practice (59.0%). Implementation factors that may have influenced the results, such as referral problems and treatment delivery, are discussed. (Am J Addict 2010;19:283–290)
Developmental Pathways from Parental Substance Use to Childhood Academic Achievement
Authors: Brook Judith S. , Saar Naomi S. , Brook David W.
Published: April 2010

This cross‐sectional study examined the pathways to childhood academic achievement in 209 African American and Puerto Rican children and their mothers. There were three pathways to childhood academic achievement: (a) the mother–child relationship and the child's personality mediated between low parental substance use and childhood academic achievement; (b) the child's personality mediated between high parental education and childhood academic achievement; and (c) there was a direct relationship between the child's gender and childhood academic achievement. Policy and clinical implications suggest the importance of increasing educational opportunities for all parents by providing substance use treatment and self‐esteem workshops. (Am J Addict 2010;19:270–276)
Improving PTSD/Substance Abuse Treatment in the VA: A Survey of Providers
Authors: Najavits Lisa M. , Norman Sonya B. , Kivlahan Daniel , Kosten Thomas R.
Published: April 2010

We surveyed 205 Veterans Affairs (VA) staff on treatment of posttraumatic stress disorder (PTSD), substance use disorder (SUD), and the combination (PTSD/SUD). The survey was anonymous and VA‐wide. PTSD/SUD was perceived as more difficult to treat than either disorder alone; gratification in the work was stronger than difficulty (for PTSD, SUD, and PTSD/SUD); and difficulty and gratification appeared separate constructs. Respondents endorsed views that represent expert treatment for the comorbidity; however, there was also endorsement of “myths.” Thus, there is a need for more training, policy clarifications, service integration, and adaptations for veterans returning from Iraq and Afghanistan. Limitations are described. (Am J Addict 2010;19:257–263)
Buprenorphine in Maintenance Treatment: Experience among Italian Physicians in Drug Addiction Centers
Authors: Quaglio Gianluca , Pattaro Cristian , Gerra Gilberto , Mezzelani Paolo , Montanari Linda , Jarlais Don C. Des , Lugoboni Fabio
Published: April 2010

The aim of this study was to assess the attitudes of Italian physicians regarding buprenorphine and its clinical use approximately 6 years after the medication was introduced into clinical practice. The sample consisted of 305 randomly selected physicians, working in public centers of drug addiction. In Italy buprenorphine seems a valid tool in the field of drug addiction treatment, although it is far from replacing methadone even though it seems to guarantee better compliance. Interviewees follow clinical experience more than international guidelines, with pharmaceutical company representatives as the most cited source for information about the medication. The data also suggests a need for the development of formal guidelines for treatment with buprenorphine in Italy. (Am J Addict 2010;19:222–230)
Factors associated with nonbenzodiazepine antiepileptic drug intoxication: Analysis of 9,809 registered cases of drug poisoning
Authors: Hassanian‐Moghaddam Hossein , Zarei Mohammad‐Reza , Kargar Mona , Sarjami Saeedeh , Rasouli Mohammad R.
Published: April 2010

Purpose:  Antiepileptic drug (AED) intoxications are common due in part to wide clinical application and availability. Because AEDs usually depress central nervous system function, overdosing may be potentially life‐threatening or lead to a range of adverse outcomes. The aim of this study was to identify risk factors for nonbenzodiazepine AED (NBAED) intoxication.

Methods:  In this cross‐sectional study, all consecutive adult and adolescent (>12 years old) poisoned patients who presented to the Loghman‐Hakim Poison Hospital (LHPH) during a 6‐month period were evaluated. Patients with NBAED intoxication were identified and compared to a control group of those other pharmaceutical intoxications. The risk factors for AED intoxication were identified using univariate analyses and multivariate modeling.

Results:  Among 9,809 cases of pharmaceutical agent overdose, there were 474 cases (4.8%) with NBAED intoxication. Mean age of the subjects was 24.5 ± 8.9 years. The most frequent NBAED was carbamazepine (n = 117), followed by phenobarbital (n = 77) and sodium valproate (n = 51). The most frequent motivation was intentional intoxication (95.3%). Multivariate analysis revealed that presence of medical disorders, a history of psychological events, and loneliness were associated with AED intoxication, whereas educational level had a protective effect. There was no association between previous history of parasuicide, sex, age, occupation status, and AED intoxication.

Discussion:  In conclusion, this study showed that the majority of AED intoxications are due to deliberate self poisoning. The presence of psychological events, medical disorders, and loneliness are risk factors for AED intoxication, whereas higher education level has a protective effect.
Increased seizure severity and seizure‐related death in mice lacking HCN1 channels
Authors: Santoro Bina , Lee Janet Y. , Englot Dario J. , Gildersleeve Sandra , Piskorowski Rebecca A. , Siegelbaum Steven A. , Winawer Melodie R. , Blumenfeld Hal
Published: April 2010

Persistent down‐regulation in the expression of the hyperpolarization‐activated HCN1 cation channel, a key determinant of intrinsic neuronal excitability, has been observed in febrile seizure, temporal lobe epilepsy, and generalized epilepsy animal models, as well as in patients with epilepsy. However, the role and importance of HCN1 down‐regulation for seizure activity is unclear. To address this question we determined the susceptibility of mice with either a general or forebrain‐restricted deletion of HCN1 to limbic seizure induction by amygdala kindling or pilocarpine administration. Loss of HCN1 expression in both mouse lines is associated with higher seizure severity and higher seizure‐related mortality, independent of the seizure‐induction method used. Therefore, down‐regulation of HCN1 associated with human epilepsy and rodent models may be a contributing factor in seizure behavior.
Deletions in 16p13 including GRIN2A in patients with intellectual disability, various dysmorphic features, and seizure disorders of the rolandic region
Authors: Reutlinger Constanze , Helbig Ingo , Gawelczyk Barbara , Subero Jose Ignacio Martin , Tönnies Holger , Muhle Hiltrud , Finsterwalder Katrin , Vermeer Sascha , Pfundt Rolph , Sperner Jürgen , Stefanova Irina , Gillessen‐Kaesbach Gabriele , Von Spiczak Sarah , Van Baalen Andreas , Boor Rainer , Siebert Reiner , Stephani Ulrich , Caliebe Almuth
Published: April 2010

Seizure disorders of the rolandic region comprise a spectrum of different epilepsy syndromes ranging from benign rolandic epilepsy to more severe seizure disorders including atypical benign partial epilepsy/pseudo‐Lennox syndrome, electrical status epilepticus during sleep, and Landau‐Kleffner syndrome. Centrotemporal spikes are the unifying electroencephalographic hallmark of these benign focal epilepsies, indicating a pathophysiologic relationship between the various epilepsies arising from the rolandic region. The etiology of these epilepsies is elusive, but a genetic component is assumed given the heritability of the characteristic electrographic trait. Herein we report on three patients with intellectual disability, various dysmorphic features, and epilepsies involving the rolandic region, carrying previously undescribed deletions in 16p13. The only gene located in the critical region shared by all three patients is GRIN2A coding for the alpha‐2 subunit of the neuronal N‐methyl‐d‐aspartate (NMDA) receptor.
PHYLOGENETIC PLACEMENT, GENOME SIZE, AND GC CONTENT OF THE LIQUID‐HYDROCARBON‐PRODUCING GREEN MICROALGA BOTRYOCOCCUS BRAUNII STRAIN BERKELEY (SHOWA) (CHLOROPHYTA)1
Authors: Weiss Taylor L. , Spencer Johnston J. , Fujisawa Kazuhiro , Sumimoto Koremitsu , Okada Shigeru , Chappell Joe , Devarenne Timothy P.
Published: April 2010

We report the genome size and the GC content, and perform a phylogenetic analysis on Botryococcus braunii Kütz., a green, colony‐forming, hydrocarbon‐rich alga that is an attractive source for biopetroleum. While the chemistry of the hydrocarbons produced by the B race of B. braunii has been studied for many years, there is a deficiency of information concerning the molecular biology of this alga. In addition, there has been some discrepancy as to the phylogenetic placement of the Berkeley (or Showa) strain of the B race. To clarify its classification, we isolated the Berkeley strain nuclear SSU (18S) rRNA gene and β‐actin cDNA and used these sequences for phylogenetic analysis to determine that the Berkeley strain belongs to the Trebouxiophyceae class. This finding is in agreement with other B races of B. braunii, indicating the Berkeley strain is a true B race of B. braunii. To better understand molecular aspects of B. braunii, we obtained the Berkeley strain genome size as a first step in genome sequencing. Using flow cytometry, we determined the B. braunii Berkeley genome size to be 166.2 ± 2.2 Mb. We also estimated the GC content of the Berkeley strain as 54.4 ± 1.2% for expressed gene sequences.