bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced photocurrent generation of bio-inspired graphene/ZnO composite films
Authors: Yin Shengyan , Men Xiaoju , Sun Hang , She Ping , Zhang Wei , Wu Changfeng , Qin Weiping , Chen Xiaodong
Published: April 2015

A bio-inspired honeycomb graphene/ZnO composite photoelectrode is developed, which shows a decreased light reflection and an increased photocurrent.
Polypyrrole-stabilized gold nanorods with enhanced photothermal effect towards two-photon photothermal therapy
Authors: Du Cuiling , Wang Anhe , Fei Jinbo , Zhao Jie , Li Junbai
Published: April 2015

The core–shell composite of Au–polypyrrole nanorods with high two-photon photothermal effect and stability could efficiently kill tumor cells under irradiation.
Necrotizing Enterocolitis and the Use of Thickened Liquids for Infants With Dysphagia
Authors: Gosa Memorie M. , Corkins Mark R.
Published: April 2015

Necrotizing enterocolotis (NEC) is a common cause of morbidity and mortality in infants that are born prematurely. The exact cause of NEC is not known. Clinical correlations between the use of thickened fluids and the development of NEC have been established. Thickened fluids are commonly used for the treatment of symptoms from both dysphagia and gastroesophageal reflux disease (GERD) in fragile infant populations. Despite its frequent recommendation, there is little empirical evidence to support the use of thickened fluids in pediatric populations for the treatment of dysphagia or GERD. There is emerging evidence to support the use of slower flowing bottle/nipple systems and side lying feeding position to support safe oral intake in infant populations. Speech-language pathologists who work in neonatal intensive care units and who work with other fragile infant populations must be aware of the risks associated with the use of thickened fluids in these populations and be prepared to provide alternative treatment options as appropriate.
Programmable leaky‐wave antenna with periodic J‐shaped metamaterial patches
Authors: Luo Yong , Kikuta Kazutaka , Han Zhengli , Takahashi Takuya , Hirose Akira , Toshiyoshi Hiroshi
Published: April 2015

The feasibility of digital tuning of a programmable metamaterial‐based antenna is explored. A leaky‐wave antenna is implemented by cascading metallic J‐shaped units in a composite right–left handed formation to create tunable metamaterial properties in terms of the radiation direction. The gaps in the J‐shaped units are programmed in either open or close to alter the radiation patterns. Owing to the electromagnetic homogeneity where the unit length is smaller than one‐fifth of the wavelength, changing the gap states has an equivalent effect to gradually tune the dispersion diagram. Eight J‐shaped patches are integrated in the leaky‐wave antenna, and nine different gap states are designed. The dispersion diagram is found to vary the transition frequency from 9.4 to 8.7 GHz with steps of 0.1 GHz, thereby frequency‐dependent scanning radiation patterns are realised. Moreover, thanks to the gradually varying dispersion diagram, a state‐dependent which also means programmable scanning radiation patterns are acquired in the band from 9 to 9.3 GHz. Experiment results agree well with the finite‐element‐method numerical analysis.
Lung cancer detection using frequency‐domain microwave imaging
Authors: Zamani A. , Rezaeieh S.A. , Abbosh A.M.
Published: April 2015

A frequency‐domain algorithm for the early detection of lung cancer is presented. The algorithm predicts the distribution of scattered fields inside the imaged domain (torso) using the measured fields around that domain. That prediction is based on using the first‐order Bessel function of the first kind to relate the fields outside the imaged domain to the fields inside that domain. The predicted field distribution shows the relative differences between the dielectric properties of tissues within the torso and thus enables detecting lung cancer, which has a significantly larger dielectric constant that the lung's healthy tissues. To validate the proposed algorithm, an integrated imaging system, which includes a three‐dimensional slot‐rotated antenna that circularly scans an artificial torso phantom using the band 1.5–3 GHz, a wideband microwave transceiver and a laptop for control, processing and image generation, is built. The obtained experimental results confirm the reliability of the proposed method in lung cancer detection.
Automatic modulation classification technique for radio monitoring
Authors: Weber C. , Peter M. , Felhauer T.
Published: April 2015

The automatic classification of the modulation format of a detected signal is the intermediate step between signal detection and demodulation. If neither the transmitted data nor other signal parameters such as the frequency offset, phase offset and timing information are known, then automatic modulation classification (AMC) is a challenging task in radio monitoring systems. The approach of clustering algorithms is a new trend in AMC for digital modulations. A novel algorithm called ‘highest constellation pattern matching’ is introduced to identify quadrature amplitude modulation and phase shift keying signals. The obtained simulation and measurement results outperform the existing algorithms for AMC based on clustering. Finally, it is shown that the proposed algorithm works in a real monitoring environment.
Integer programming approach to unequal error protection coding for multiuser broadcast channels
Authors: Jung Wook , Chang Shih‐Chun
Published: April 2015

In this study, an integer programming approach is introduced to construct unequal error protection (UEP) codes for a multiuser broadcast communication system. The authors establish integer programming models for both binary and non‐binary UEP codes. The results show that optimal UEP codes can be constructed such that their code lengths achieve the integer programming bounds. Based on the bounds, the authors investigate asymptotic behaviour of code rates with symbols in 𝔼𝔼(q), and the authors present performance analysis of multiuser communications over a degraded broadcast channel with the optimal UEP codes.
Short‐term fading model for signals reflected by ocean surfaces in underwater acoustic communication
Authors: Kim Joonsuk , Koh Il‐Suek , Lee Yongshik
Published: April 2015

A short‐term fading model based on rough surface theory is proposed to estimate stochastic characteristics of signals reflected by time‐varying ocean surfaces in underwater acoustic channels. With this method, probability density functions of the fluctuations in the propagation delay and magnitude, and the Doppler spectral densities are provided with respect to wind speeds. After conducting several experiments and verifying them by comparing with the measurements, it is shown that the model accurately estimates the stochastic characteristics. The proposed model is valid when the transmitter and receiver locate sufficiently far away from the ocean surface.
Performance analysis of opportunistic relaying and opportunistic hybrid incremental relaying over fading channels
Authors: Yasar Lateef Hafiz , Dyo Vladimir , Allen Ben
Published: April 2015

In this study, the authors develop and present a comprehensive analysis of two opportunistic cooperative relaying schemes for long term evolution (LTE)‐advanced networks operating over generalised‐K and Nakagami‐m fading channels. They present and compare the performance of opportunistic relaying (OR) and opportunistic hybrid automatic repeat request incremental relaying (OHIR). They analyse performance in terms of the average symbol error rate for both conventional OR and OHIR LTE‐advanced networks with the radio channel modelled as composite generalised‐K fading (encompassing both fading and shadowing) and Nakagami‐m fading channels. They also analyse the outage probability for OR operating over these channels. Both the theoretical analysis and simulations confirm that for conventional OR LTE‐advanced networks operating over composite generalised‐K fading channels, a diversity order of k(N + 1) is achieved when shadowing is more severe than fading, and a diversity order of m(N + 1) is achieved when fading is more severe than shadowing (where k and m represent the generalised‐K distribution shape parameters and N represents the number of candidate relays for the OR selection). The simulation results confirm the accuracy of the analytical expressions developed in this study. It is evident from the theoretical analysis and simulations that, for a similar quality of service as that for OR, OHIR not only reduces the amount of required radio resources but also maintains the full diversity order.
Optimal design parameters for coverage probability in fractional frequency reuse and soft frequency reuse
Authors: Kumar Suman , Kalyani Sheetal , Giridhar Krishnamurthy
Published: April 2015

In this work, the authors derive the optimal signal‐to‐interference‐ratio (SIR) thresholds St which maximise coverage probability for both fractional frequency reuse (FFR) and soft frequency reuse (SFR) networks with base station locations modelled using Poisson point process. It is analytically shown that for both FFR and SFR, the optimal SIR threshold is equal to the target SIR T, i.e, St = T. The authors also show that at the optimal SIR threshold, FFR achieves a higher coverage than frequency reuse (1/Δ). Furthermore, for the cases when St > T and St < T, FFR achieves a higher coverage than reuse (1/Δ) and reuse 1, respectively. On the other hand, SFR coverage can be higher or lower than reuse (1/Δ) coverage, even when St = T. However, when St > T, SFR achieves a higher coverage than reuse 1, and when St < T, the SFR coverage can be lower than reuse 1 coverage. The FFR and SFR coverages are also compared for a given Δ, and it is shown that FFR achieves a higher coverage than SFR at the optimal value of St.
Low‐latency low‐complexity heap‐based extended min‐sum algorithms for non‐binary low‐density parity‐check codes
Authors: Hwang Youngjun , Yang Kyeongcheol , Cheun Kyungwhoon
Published: April 2015

The extended min‐sum (EMS) and improved EMS (I‐EMS) algorithms for non‐binary low‐density parity‐check codes over GF(q) significantly reduce the decoding complexity with an acceptable performance degradation, but they suffer from high latency because of many serial computations, including a sorting process. On the other hand, the trellis‐based EMS algorithm can greatly reduce the latency, but it does not solve the complexity problem in high‐order fields (q ≥ 64). To improve the latency problem with low‐complexity advantages, the authors propose heap‐based EMS (H‐EMS) and heap‐based I‐EMS (HI‐EMS) algorithms that are modifications of the EMS and I‐EMS algorithms, respectively. The authors also propose double H‐EMS and double HI‐EMS algorithms trading off the latency against the performance by heaping messages twice. Numerical results show that the H‐EMS algorithm has 2.74–9.52 times lower latency than the EMS algorithm with a negligible performance degradation over a wide range of code rates, whereas the HI‐EMS algorithm has 1.20–1.62 times lower latency than the I‐EMS algorithm. Furthermore, the proposed algorithms may be employed regardless of the decoding schedules.
Decentralised output‐feedback controller syntheses with restricted frequency‐domain specifications via generalised Kalman–Yakubovich–Popov lemma: a unified approach
Authors: Chou Yung‐Shan , Chang Yun‐Lun
Published: April 2015

This study is concerned with output‐feedback H‐infinity controller synthesis in finite frequency domain for continuous‐time multi‐channel linear systems. The recently developed results of full‐order centralised H‐infinity control theory in this field are extended to the subject of decentralised control. Both the block‐diagonal reduced‐order dynamic and static controller designs are discussed in a unified manner. Sufficient solvability conditions are given in terms of linear‐matrix‐inequalities. A numerical example is provided that establishes the efficacy of the proposed controller syntheses.
Online adaptive optimal control for continuous‐time Markov jump linear systems using a novel policy iteration algorithm
Authors: He Shuping , Song Jun , Ding Zhengtao , Liu Fei
Published: April 2015

This study studies the online adaptive optimal control problems for a class of continuous‐time Markov jump linear systems (MJLSs) based on a novel policy iteration algorithm. By utilising a new decoupling technique named subsystems transformation, the authors re‐construct the MJLSs and a set of new coupled systems composed of N subsystems are obtained. The online policy iteration algorithm was used to solve the coupled algebraic matrix Riccati equations with partial knowledge regarding to the system dynamics, and the relevant optimal controllers equivalent to the investigated MJLSs are designed. Moreover, the convergence of the novel policy iteration algorithm is also established. Finally, a simulation example is given to illustrate the effectiveness and applicability of the proposed approach.
Stochastic‐based scheduling of the microgrid operation including wind turbines, photovoltaic cells, energy storages and responsive loads
Authors: Talari Saber , Yazdaninejad Mohsen , Haghifam Mahmoud‐Reza
Published: April 2015

Microgrids with different technologies in distributed generations (DGs), different control facilities and power electronic interfaces require proper management and operation strategies. In these strategies, in order to reach the optimum scheduling, the stochastic nature of some decision variables should be considered. Subsequently, it will lead to a decrease in the forced load curtailment and an increase in the economic efficiency from the perspective of both the maingrid and the microgrid owner. In this study, the availability of dispatchable DGs, energy storage, renewable energy sources (RESs) and the maingrid as well as the power generation of RESs and load are studied through their uncertainty natures. For dealing with these uncertainties, stochastic variables computation module is designed which generates several scenarios by Monte Carlo simulation at each hour. The microgrid operation is optimised in uncertainty environment through a linear two‐stage stochastic model. The stochastic scheduling model which is solved by mixed‐integer linear programming is compared with a deterministic model through three different cases in presence of demand response on a sample microgrid. The results explicitly show benefits of the proposed stochastic model since it provides accuracy in scheduling and decreases the operation cost.
Optimal distributed static series compensator placement for enhancing power system loadability and reliability
Authors: Dorostkar‐Ghamsari Mohammadreza , Fotuhi‐Firuzabad Mahmud , Aminifar Farrokh , Safdarian Amir , Lehtonen Matti
Published: April 2015

Distributed static series compensator (DSSC) is a member of the family of distributed flexible AC transmission system devices that can be attached directly to conductors of transmission lines. DSSCs are able to compensate for and adjust the line reactance; thus, they could be widely used in stability‐limited transmission systems. Owing to economic matters, the optimal placement of DSSCs is of a great interest from practical viewpoints. This study presents an approach to find the optimal locations of DSSCs to enhance the system loadability and reliability using the DC load flow model. The optimisation problem is solved using the mixed‐integer linear programming. A compromise between improving the system loadability and reliability is fulfilled and a wide range of non‐dominated optimal solutions is calculated. The final solution is then selected using the fuzzy satisfying method. Numerical studies are conducted on the IEEE reliability test system (IEE‐RTS).
Modular double‐cascade converter for high‐power medium‐voltage drives
Authors: Sankala Arto , Korhonen Juhamatti , Ström Juha‐Pekka , Luukko Julius , Silventoinen Pertti , Komulainen Risto , Sarén Hannu , Södö Nicklas , Isaksson Dan
Published: April 2015

The modular double‐cascade converter (MDC) is a new multilevel AC/AC converter topology, which has a modular structure. The proposed topology can be used in medium‐voltage motor and generator drives, and in interfacing of grids of different voltages and frequencies. MDC is formed with two sets of cascaded H‐bridges where the isolation of the power modules is carried out with medium‐frequency multiwinding transformers. Although the transformers have a transformation ratio of one, the presented topology can be used to transform the voltage level by using different connections for the input and output H‐bridges. The number of steps of input and output voltages can be varied by connecting the modular units of MDC in series or in parallel. The functionality of the topology is verified by simulations of a seven‐level version for a 3.3 kV, 1.1 MW application and experimental results are shown for a 400 V, 76 kW three‐level inverter. In particular, an inherent submodule energy sharing capability through the transformer is analysed and assessed by simulations and experimental tests.
Calorimetric measurements on Li4C60 and Na4C60
Authors: Inaba Akira , Miyazaki Yuji , Michałowski Paweł P. , Gracia-Espino Eduardo , Sundqvist Bertil , Wågberg Thomas
Published: April 2015

We show specific heat data for Na4C60 and Li4C60 in the range 0.4-350 K for samples characterized by Raman spectroscopy and X-ray diffraction. At high temperatures, the two different polymer structures have very similar specific heats both in absolute values and in general trend. The specific heat data are compared with data for undoped polymeric and pristine C60. At high temperatures, a difference in specific heat between the intercalated and undoped C60 polymers of 100 J K−1 mol−1 is observed, in agreement with the Dulong-Petit law. At low temperatures, the specific heat data for Li4C60 and Na4C60 are modified by the stiffening of vibrational and librational molecular motion induced by the polymer bonds. The covalent twin bonds in Li4C60 affect these motions to a somewhat higher degree than the single intermolecular bonds in Na4C60. Below 1 K, the specific heats of both materials become linear in temperature, as expected from the effective dimensionality of the structure. The contribution to the total specific heat from the inserted metal ions can be well described by Einstein functions with TE = 386 K for Li4C60 and TE = 120 K for Na4C60, but for both materials we also observe a Schottky-type contribution corresponding to a first approximation to a two-level system with ΔE = 9.3 meV for Li4C60 and 3.1 meV for Na4C60, probably associated with jumps between closely spaced energy levels inside “octahedral-type” ionic sites. Static magnetic fields up to 9 T had very small effects on the specific heat below 10 K.
On the use of Abelian point group symmetry in density-fitted local MP2 using various types of virtual orbitals
Authors: Köppl Christoph , Werner Hans-Joachim
Published: April 2015

Electron correlation methods based on symmetry-adapted canonical Hartree-Fock orbitals can be speeded up significantly in the well known group theoretical manner, using the fact that integrals vanish unless the integrand is totally symmetric. In contrast to this, local electron correlation methods cannot benefit from such simplifications, since the localized molecular orbitals (LMOs) generally do not transform according to irreducible representations of the underlying point group symmetry. Instead, groups of LMOs become symmetry-equivalent and this can be exploited to accelerate local calculations. We describe an implementation of such a symmetry treatment for density-fitted local Møller-Plesset perturbation theory, using various types of virtual orbitals: Projected atomic orbitals, orbital specific virtuals, and pair natural orbitals. The savings by the symmetry treatment are demonstrated by calculations for several large molecules having different point group symmetries. Benchmarks for the parallel execution efficiency of our method are also presented.
Near equilibrium distributions for beams with space charge in linear and nonlinear periodic focusing systems
Authors: Sonnad Kiran G. , Cary John R.
Published: April 2015

A procedure to obtain a near equilibrium phase space distribution function has been derived for beams with space charge effects in a generalized periodic focusing transport channel. The method utilizes the Lie transform perturbation theory to canonically transform to slowly oscillating phase space coordinates. The procedure results in transforming the periodic focusing system to a constant focusing one, where equilibrium distributions can be found. Transforming back to the original phase space coordinates yields an equilibrium distribution function corresponding to a constant focusing system along with perturbations resulting from the periodicity in the focusing. Examples used here include linear and nonlinear alternating gradient focusing systems. It is shown that the nonlinear focusing components can be chosen such that the system is close to integrability. The equilibrium distribution functions are numerically calculated, and their properties associated with the corresponding focusing system are discussed.
Transmission electron microscopy and ab initio calculations to relate interfacial intermixing and the magnetism of core/shell nanoparticles
Authors: Chi C.-C. , Hsiao C.-H. , Skoropata E. , van Lierop J. , Ouyang Chuenhou (Hao)
Published: April 2015

Significant efforts towards understanding bi-magnetic core-shell nanoparticles are underway currently as they provide a pathway towards properties unavailable with single-phased systems. Recently, we have demonstrated that the magnetism of γ-Fe2O3/CoO core-shell nanoparticles, in particular, at high temperatures, originates essentially from an interfacial doped iron-oxide layer that is formed by the migration of Co2+ from the CoO shell into the surface layers of the γ-Fe2O3 core [Skoropata et al., Phys. Rev. B 89, 024410 (2014)]. To examine directly the nature of the intermixed layer, we have used high-resolution transmission electron microscopy (HRTEM) and first-principles calculations to examine the impact of the core-shell intermixing at the atomic level. By analyzing the HRTEM images and energy dispersive spectra, the level and nature of intermixing was confirmed, mainly as doping of Co into the octahedral site vacancies of γ-Fe2O3. The average Co doping depths for different processing temperatures (150 °C and 235 °C) were 0.56 nm and 0.78 nm (determined to within 5% through simulation), respectively, establishing that the amount of core-shell intermixing can be altered purposefully with an appropriate change in synthesis conditions. Through first-principles calculations, we find that the intermixing phase of γ-Fe2O3 with Co doping is ferromagnetic, with even higher magnetization as compared to that of pure γ-Fe2O3. In addition, we show that Co doping into different octahedral sites can cause different magnetizations. This was reflected in a change in overall nanoparticle magnetization, where we observed a 25% reduction in magnetization for the 235 °C versus the 150 °C sample, despite a thicker intermixed layer.
Electronic damage in S atoms in a native protein crystal induced by an intense X-ray free-electron laser pulse
Authors: Galli L. , Son S.-K. , Klinge M. , Bajt S. , Barty A. , Bean R. , Betzel C. , Beyerlein K. R. , Caleman C. , Doak R. B. , Duszenko M. , Fleckenstein H. , Gati C. , Hunt B. , Kirian R. A. , Liang M. , Nanao M. H. , Nass K. , Oberthür D. , Redecke L. , Shoeman R. , Stellato F. , Yoon C. H. , White T. A. , Yefanov O. , Spence J. , Chapman H. N.
Published: April 2015

Current hard X-ray free-electron laser (XFEL) sources can deliver doses to biological macromolecules well exceeding 1 GGy, in timescales of a few tens of femtoseconds. During the pulse, photoionization can reach the point of saturation in which certain atomic species in the sample lose most of their electrons. This electronic radiation damage causes the atomic scattering factors to change, affecting, in particular, the heavy atoms, due to their higher photoabsorption cross sections. Here, it is shown that experimental serial femtosecond crystallography data collected with an extremely bright XFEL source exhibit a reduction of the effective scattering power of the sulfur atoms in a native protein. Quantitative methods are developed to retrieve information on the effective ionization of the damaged atomic species from experimental data, and the implications of utilizing new phasing methods which can take advantage of this localized radiation damage are discussed.
Quantum mechanical differential and integral cross sections for the C(1D) + H2(ν = 0, j = 0) → CH(ν′, j′) + H reaction
Authors: Shen Zhitao , Cao Jianwei , Bian Wensheng
Published: April 2015

Accurate quantum dynamics calculations for the C(1D) + H2 reaction are performed using a real wave packet approach with full Coriolis coupling. The newly constructed ZMB-a ab initio potential energy surface [Zhang et al., J. Chem. Phys. 140, 234301 (2014)] is used. The integral cross sections (ICSs), differential cross sections (DCSs), and product state distributions are obtained over a wide range of collision energies. In contrast to previous accurate quantum dynamics calculations on the reproducing kernel Hilbert space potential energy surface, the present total ICS is much larger at low collision energies, yielding larger rate coefficients in better agreement with experiment and with slight inverse temperature dependence. Meanwhile, interesting nonstatistical behaviors in the DCSs are revealed. In particular, the DCSs display strong oscillations with the collision energy; forward biased product angular distribution appears when only small J partial wave contributions are included; alternate forward and backward biases emerge with very small increments of collision energy; and the rotational state-resolved DCSs show strong oscillations with the scattering angle. Nevertheless, the total DCSs can be roughly regarded as backward–forward symmetric over the whole energy range and are in reasonably good agreement with the available experimental measurements.
Asymptotic behavior of generalized *-derivations on C*-algebras with applications
Authors: Kim Hark-Mahn , Chang Ick-Soon
Published: April 2015

We consider generalized *-derivations on C*-algebra and we will first study the conditions for a linear generalized *-derivation on C*-algebra. Then we prove some theorems involving approximate linear generalized *-derivations on C*-algebra. So approximate linear generalized *-derivations on C*-algebra are characterized.
Low-frequency and wideband vibration energy harvester with flexible frame and interdigital structure
Authors: Li Pengwei , Liu Ying , Wang Yanfen , Luo Cuixian , Li Gang , Hu Jie , Liu Wei , Zhang Wendong
Published: April 2015

As an alternative to traditional cantilever beam structures and their evolutions, a flexible beam based, interdigital structure, vibration energy harvester has been presented and investigated. The proposed interdigital-shaped oscillator consists of a rectangular flexible frame and series of cantilever beams interdigitally bonded to it. In order to achieve low frequency and wide-bandwidth harvesting, Young’s modulus of materials, frame size and the amount of the cantilevers have been studied systematically. The measured frequency responses of the designed device (PDMS frame, quintuple piezoelectric cantilever beams) show a 460% increase in bandwidth below 80Hz. When excited at an acceleration of 1.0 g, the energy harvester achieves to a maximum open-circuit voltage of 65V, and the maximum output power 4.5 mW.
Genetic dissection of the developmental behaviour of total starch content and its components in wheat grain
Authors: Tian Bin , Deng Zhiying , Xie Quangang , Tian Jichun
Published: April 2015

Starch in wheat is an important component of flour and is related to grain yield and wheat end-products. In this study, a doubled haploid (DH) population with 168 lines derived from a cross of elite Chinese wheat (Triticum aestivum L.) cultivars Huapei 3 and Yumai 57 was used to identify dynamic quantitative trait loci (QTLs) for total starch content (TSC), amylose (AMS) and amylopectin (AMP) in wheat grain. Traits were measured at stages, grown under three treatments in two seasons, and were assessed by unconditional and conditional QTL analyses. Thirty-three additive QTLs and 21 pairs of epistatic QTLs for TSC, AMS and AMP were detected by unconditional mapping, whereas 19 additive QTLs and 15 pairs of epistatic QTLs were identified by conditional mapping. Of these, QTsc4A.1 and QAms4A.1 were detected continuously at five stages under three treatments in two seasons by unconditional mapping, indicating that the accumulated effects of these QTLs were expressed stably from 12 days after flowering (DAF) and were little affected by nitrogen and water agronomic treatment. These two QTLs also showed net expression from 12 to 22 DAF by conditional mapping. The results indicate that the two loci play an important role in starch synthesis. Most of the epistatic QTLs belonged to a minor QTL, but played an important role in the target traits. Therefore, the development of starch is mainly affected by additive effects besides the epistasis effect. The data are useful for potential marker-assisted selection and cloning of the target gene in further fine mapping, and provide a foundation to understand the genetic mechanism underlying the development of starch in wheat and to increase yield.
Comparative expression profiling of three early inflorescence stages of oil palm indicates that vegetative to reproductive phase transition of meristem is regulated by sugar balance
Authors: Ajambang Walter , Ardie Sintho W. , Volkaert Hugo , Ngando-Ebongue Georges F. , Sudarsono Sudarsono
Published: April 2015

Breeding and seed production activities in oil palm have been hampered because of the inability of the male parent Pisifera to produce male inflorescence as source of pollen under normal conditions. Researchers are using complete defoliation to induce male inflorescences, but the biological and molecular processes responsible for this morphological change are yet to be revealed. To understand the underlying network of genes that initiate and control this phenotypically documented activity, we initiated a study aimed at identifying differentially expressed genes (DEGs) in three stages of an oil palm inflorescence under complete defoliation stress using RNA-seq. Sequencing on an Illumina platform produced 82 631 476 reads consisting of 8 345 779 076 bases. A total of 60 700 genes were obtained after transcript filtering and normalisation and 54% of them were downregulated. Differences in gene expression levels were significant between tissues under stress. The farther the distance between tissues, the more DEGs recorded. Comparison between stage 2 and stage 1 induced 3893 DEGs whereas 10 136 DEGs were induced between stage 3 and stage 1. Stress response genes and flower development genes were among the highly expressed genes. This study suggests a link between complete defoliation and meristem differentiation from vegetative to reproductive phase in oil palm.
Crystal structure of the human mitochondrial chaperonin symmetrical football complex
Authors: Nisemblat Shahar , Yaniv Oren , Parnas Avital , Frolow Felix , Azem Abdussalam
Published: April 2015

Significance

The human mitochondrial chaperonin is vital for proper cell function because it assists in folding of mitochondrial proteins. Additionally, it participates in extramitochondrial processes, such as apoptosis, inflammation, and carcinogenesis. In this study, we report the crystal structure of mitochondrial chaperonins. The model shows an “American football”-shaped intermediate, composed of two 7-membered chaperonin rings capped at each end by a cochaperonin ring. This complex was captured in the early stages of dissociation. The extensive interface contacts between its rings, the asymmetry that exists within each ring, and symmetric binding of nucleotide cofactors that exists between the rings suggest that the mitochondrial system operates via a mechanism that is distinct from the mechanism of the canonical
Escherichia coli
(GroEL/GroES) system.
Brown Trout Removal Effects on Short‐Term Survival and Movement of Myxobolus cerebralis‐Resistant Rainbow Trout
Authors: Fetherman Eric R. , Winkelman Dana L. , Bailey Larissa L. , Schisler George J. , Davies K.
Published: April 2015

Following establishment of Myxobolus cerebralis (the parasite responsible for salmonid whirling disease) in Colorado, populations of Rainbow Trout Oncorhynchus mykiss experienced significant declines, whereas Brown Trout Salmo trutta densities increased in many locations across the state, potentially influencing the success of M. cerebralis‐resistant Rainbow Trout reintroductions. We examined the effects of Brown Trout removal on the short‐term (3‐month) survival and movement of two crosses of reintroduced, M. cerebralis‐resistant Rainbow Trout in the Cache la Poudre River, Colorado. Radio frequency identification passive integrated transponder tags and antennas were used to track movements of wild Brown Trout and stocked Rainbow Trout in reaches where Brown Trout had or had not been removed. Multistate mark–recapture models were used to estimate tagged fish apparent survival and movement in these sections 3 months following Brown Trout removal. A cross between the German Rainbow Trout and Colorado River Rainbow Trout strains exhibited similar survival and movement probabilities in the reaches, suggesting that the presence of Brown Trout did not affect its survival or movement. However, a cross between the German Rainbow Trout and Harrison Lake Rainbow Trout exhibited less movement from the reach in which Brown Trout had been removed. Despite this, the overall short‐term benefits of the removal were equivocal, suggesting that Brown Trout removal may not be beneficial for the reintroduction of Rainbow Trout. Additionally, the logistical constraints of conducting removals in large river systems are substantial and may not be a viable management option in many rivers.
Abundance, Survival, and Life History Strategies of Juvenile Chinook Salmon in the Skagit River, Washington
Authors: Zimmerman Mara S. , Kinsel Clayton , Beamer Eric , Connor Edward J. , Pflug David E.
Published: April 2015

To identify potential actions for conserving Chinook SalmonOncorhynchus tshawytschain the Skagit River, Washington, we used a 16‐year time series of streamflow data, adult escapement, and out‐migrant abundance to understand how out‐migrant abundance and life history diversity were related to spawner abundance and incubation flows. Three freshwater rearing strategies were distinguished based on body size at out‐migration: fry (≤45 mm FL), subyearling parr (46–100 mm FL), and yearling smolts (>100 mm FL). Density‐independent and density‐dependent processes were hypothesized to influence survival in sequence, with density‐independent mechanisms operating during incubation and density‐dependent mechanisms operating between emergence and out‐migration. A model selection process compared spawner–recruit models with and without different incubation flow metrics. Density‐independent models that included measures of flow duration and magnitude were strongly supported (Akaike's information criterion [AIC] difference ≤ 3). Sustained flow events of moderate magnitude (1‐year recurrence interval) were an equivalent if not better predictor of freshwater survival than short‐duration flow events of high magnitude (peak flows). A second model selection process evaluated density dependence of each life history type. The composition of out‐migrants (fry, subyearling parr, and yearling smolts) was a density‐dependent function of spawner abundance. Fry out‐migrant abundance was density independent, and subyearling parr out‐migrant abundance was density dependent. Neither model was supported for yearling smolts. At least one out‐migrant life history, subyearling parr, should benefit from continued restoration of freshwater habitats in the Skagit River system. Factors contributing to the yearling smolt life history will benefit from additional study.
A hot water extract ofCurcuma longainhibits adhesion molecule protein expression and monocyte adhesion to TNF-α-stimulated human endothelial cells
Authors: Kawasaki Kengo , Muroyama Koutarou , Yamamoto Norio , Murosaki Shinji
Published: April 2015

The recruitment of arterial leukocytes to endothelial cells is an important step in the progression of various inflammatory diseases. Therefore, its modulation is thought to be a prospective target for the prevention or treatment of such diseases. Adhesion molecules on endothelial cells are induced by proinflammatory cytokines, including tumor necrosis factor-α (TNF-α), and contribute to the recruitment of leukocytes. In the present study, we investigated the effect of hot water extract of Curcuma longa (WEC) on the protein expression of adhesion molecules, monocyte adhesion induced by TNF-α in human umbilical vascular endothelial cells (HUVECs). Treatment of HUVECs with WEC significantly suppressed both TNF-α-induced protein expression of adhesion molecules and monocyte adhesion. WEC also suppressed phosphorylation and degradation of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) induced by TNF-α in HUVECs, suggesting that WEC inhibits the NF-κB signaling pathway.
Anniversary of the discovery/isolation of the yeast centromere by Clarke and Carbon
Authors: Bloom Kerry
Published: April 2015

The first centromere was isolated 35 years ago by Louise Clarke and John Carbon from budding yeast. They embarked on their journey with rudimentary molecular tools (by today's standards) and little knowledge of the structure of a chromosome, much less the nature of a centromere. Their discovery opened up a new field, as centromeres have now been isolated from fungi and numerous plants and animals, including mammals. Budding yeast and several other fungi have small centromeres with short, well-defined sequences, known as point centromeres, whereas regional centromeres span several kilobases up to megabases and do not seem to have DNA sequence specificity. Centromeres are at the heart of artificial chromosomes, and we have seen the birth of synthetic centromeres in budding and fission yeast and mammals. The diversity in centromeres throughout phylogeny belie conserved functions that are only beginning to be understood.
Rapid bursts and slow declines: on the possible evolutionary trajectories of enzymes
Authors: Newton Matilda S. , Arcus Vickery L. , Patrick Wayne M.
Published: April 2015

The evolution of enzymes is often viewed as following a smooth and steady trajectory, from barely functional primordial catalysts to the highly active and specific enzymes that we observe today. In this review, we summarize experimental data that suggest a different reality. Modern examples, such as the emergence of enzymes that hydrolyse human-made pesticides, demonstrate that evolution can be extraordinarily rapid. Experiments to infer and resurrect ancient sequences suggest that some of the first organisms present on the Earth are likely to have possessed highly active enzymes. Reconciling these observations, we argue that rapid bursts of strong selection for increased catalytic efficiency are interspersed with much longer periods in which the catalytic power of an enzyme erodes, through neutral drift and selection for other properties such as cellular energy efficiency or regulation. Thus, many enzymes may have already passed their catalytic peaks.
Social evolution in the shadow of asymmetrical relatedness
Authors: Krupp D. B. , Taylor Peter D.
Published: April 2015

The persistence of altruism and spite remains an enduring problem of social evolution. It is well known that selection for these actions depends on the structure of the population—that is, on actors' genetic relationships to recipients and to the ‘neighbourhood’ upon which the effects of their actions redound. Less appreciated, however, is that population structure can cause genetic asymmetries between partners whereby the relatedness (defined relative to the neighbourhood) of an individualito a partnerjwill differ from the relatedness ofjtoi. Here, we introduce a widespread mechanism of kin recognition to a model of dispersal in subdivided populations. In so doing, we uncover three remarkable consequences of asymmetrical relatedness. First, altruism directed at phenotypically similar partners evolves more easily among migrant than native actors. Second, spite directed at dissimilar partners evolves more easily among native than migrant actors. Third, unlike migrants, natives can evolve to pay costs that far outstrip those they spitefully impose on others. We find that the frequency of natives relative to migrants amplifies the asymmetries between them. Taken together, our results reveal differentiated patterns of ‘phenocentrism’ that readily arise from asymmetries of relatedness.
Lactobacillus plajomi sp. nov. and Lactobacillus modestisalitolerans sp. nov., isolated from traditional fermented foods
Authors: Miyashita Mika , Yukphan Pattaraporn , Chaipitakchonlatarn Winai , Malimas Taweesak , Sugimoto Masako , Yoshino Mayumi , Kamakura Yuki , Potacharoen Wanchern , Tanasupawat Somboon , Tanaka Naoto , Nakagawa Yasuyoshi , Suzuki Ken-ichiro
Published: April 2015

Three Lactobacillus-like strains, NB53T, NB446T and NB702, were isolated from traditional fermented food in Thailand. Comparative 16S rRNA gene sequence analysis indicated that these strains belong to the Lactobacillus plantarum group. Phylogenetic analysis based on the dnaK, rpoA, pheS and recA gene sequences indicated that these three strains were distantly related to known species present in the L. plantarum group. DNA–DNA hybridization with closely related strains demonstrated that these strains represented two novel species; the novel strains could be differentiated based on chemotaxonomic and phenotypic characteristics. Therefore, two novel species of the genus Lactobacillus, Lactobacillus plajomi sp. nov. (NB53T) and Lactobacillus modestisalitolerans sp. nov. (NB446T and NB702), are proposed with the type strains NB53T ( = NBRC 107333T = BCC 38054T) and NB446T ( = NBRC 107235T = BCC 38191T), respectively.
In situsynchrotron X-ray diffraction investigation of the evolution of a PbO2/PbSO4surface layer on a copper electrowinning Pb anode in a novel electrochemical flow cell. Corrigendum
Authors: Clancy Marie , Styles Mark J. , Bettles Colleen J. , Birbilis Nick , Chen Miao , Zhang Yansheng , Gu Qinfen , Kimpton Justin A. , Webster Nathan A. S.
Published: April 2015

Figures 7 and 8 of the article by Clancyet al.[(2015),J. Synchrotron Rad.22, 366–375] are corrected.
Crystal structure of bis[4-(dimethylamino)pyridine-κN1]bis(methanol-κO)bis(thiocyanato-κN)manganese(II)
Authors: Suckert Stefan , Jess Inke , Näther Christian
Published: April 2015

The whole molecule of the title compound, [Mn(NCS)2(CH3OH)2(C5H6N2)2], is generated by inversion symmetry. The MnIIion, which is located on an inversion center, is coordinated by two 4-(dimethylamino)pyridine ligands, two methanol ligands and two terminallyN-bonded thiocyanate anions, forming a slightly distorted octahedron. In the crystal, molecules are linked by O—H...S hydrogen bonds, forming chains extending along thea-axis direction.
Crystal structure of 4-methyl-N-[2-(piperidin-1-yl)ethyl]benzamide monohydrate
Authors: Revathi B. K. , Reuben Jonathan D. , Sathya S. , Prathebha K. , Usha G.
Published: April 2015

In the title compound, C15H22N2O·H2O, the dihedral angle between the planes of the piperidine and benzene rings is 31.63 (1)°. The piperidine ring adopts a chair conformation. The water solvent molecule is involved in interspecies O—H...O, O—H...N, N—H...O and weak C—H...O hydrogen-bonding interactions, giving rise to chains extending along [010].
Crystal structure of 2-methyl-N-[(4-methylpyridin-2-yl)carbamothioyl]benzamide
Authors: Ameram Nadiah , Adam Farook , Fatihah Nur Nadia , Al-Juaid Salih
Published: April 2015

In the title compound, C15H15N3OS, there is an intramolecular N—H...O hydrogen bond and an intramolecular C—H...S hydrogen bond involving the C=O and C=S bonds which lie on opposite sides of the molecule. The molecule is non-planar with the benzene and pyridine rings being inclined to one another by 26.86 (9)°. In the crystal, molecules are linked by pairs of N—H...S hydrogen bonds, forming inversion dimers with anR22(8) ring motif. The dimers are linkedviaC—H...S hydrogen bonds, forming slabs parallel to thebcplane.
Crystal structure of 3-bromomethyl-2-chloro-6-(dibromomethyl)quinoline
Authors: Gayathri Kasirajan , Mohan Palathurai S. , Howard Judith A. K. , Sparkes Hazel A.
Published: April 2015

In the title compound, C11H7Br3ClN, the quinoline ring system is approximately planar (r.m.s. = 0.011 Å). In the crystal, molecules are linked by C—H...Br interactions forming chains along [10-1]. The chains are linked by C—H...π and π–π interactions involving inversion-related pyridine rings [intercentroid distance = 3.608 (4) Å], forming sheets parallel to (10-1). Within the sheets, there are two significant short interactions involving a Br...Cl contact of 3.4904 (18) Å and a Br...N contact of 3.187 (6) Å, both of which are significantly shorter than the sum of their van der Waals radii.
Crystal structure of (E)-3-(3,4-dimethoxyphenyl)-1-(1-hydroxynaphthalen-2-yl)prop-2-en-1-one
Authors: Ezhilarasi K. S. , Reuben Jonathan D. , Vasanthi R. , Revathi B. K. , Usha G.
Published: April 2015

The molecular structure of the title compound, C21H18O4, consists of a 3,4-dimethoxyphenyl ring and a naphthalene ring system linkedviaa prop-2-en-1-one spacer. The molecule is almost planar, with a dihedral angle between the benzene ring and the naphthalene ring system of 2.68 (12)°. There is an intramolecular O—H...O hydrogen bond involving the adjacent hydroxy and carbonyl groups. The molecule has anEconformation about the C=C bond and the carbonyl group issynwith respect to the C=C bond. In the crystal, molecules are linked by bifurcated C—H...(O,O) hydrogen bonds, enclosing anR21(6) ring motif, and by a further C—H...O hydrogen bond, forming undulating sheets extending inb-andc-axis directions. There are π–π interactions between the sheets, involving inversion-related naphthalene and benzene rings [intercentroid distance = 3.7452 (17) Å], forming a three-dimensional structure.
Crystal structure of [2-(triethylammonio)ethyl][(2,4,6-triisopropylphenyl)sulfonyl]amide tetrahydrate
Authors: Golz C. , Strohmann C.
Published: April 2015

The zwitterionic title compound, C23H42N2O2S·4H2O, crystallized as a tetrahydrate from a solution ofN-[(2,4,6-triisopropylphenyl)sulfonyl]aziridine in triethylamine, diethyl ether and pentane in the presence of moist air. It is formed by a nucleophillic ring-opening that is assumed to be reversible. The molecular structure shows a major disorder of the triisopropylphenyl group over two equally occupied locations. An interesting feature is the uncommon hydrate structure, exhibiting a tape-like motif which can be classified as a transition of the one-dimensional T4(2)6(2) motif into the two-dimensional L4(6)5(7)6(8) motif.
Crystal structure of ethyl 2-amino-4-(4-methoxyphenyl)-4H-1-benzothieno[3,2-b]pyran-3-carboxylate
Authors: Bakhouch Mohamed , Kerbal Abdelali , El Yazidi Mohamed , Saadi Mohamed , El Ammari Lahcen
Published: April 2015

The molecule of the title compound, C21H19NO4S, features a fused ring system whereby a five-membered ring is flanked by two six-membered rings. This is linked to an ethyl 3-carboxylate group and to a methoxybenzene group. The fused-ring system is quasi-planar, with the greatest deviation from the mean plane being 0.131 (1) Å for the methine C atom. The plane through the methoxybenzene ring is nearly perpendicular to that through the fused-ring system, as indicated by the dihedral angle of 85.72 (6)°. An intramolecular N—H...O hydrogen bond is noted. In the crystal, molecules are linked by N—H...O hydrogen bonds, forming layers that stack along theaaxis.