bluuebunny/crossref_metadata_2025 huggingface dataset:
Control of defect binding and magnetic interaction energies in dilute magnetic semiconductors by charge state manipulation
Authors: Raebiger Hannes , Nakayama Hikaru , Fujita Takeshi
Published: January 2014

Dilute magnetic semiconductors exhibit a unique entanglement of magnetism and semiconductor properties. Their properties are dominated by short-range chemical and magnetic interactions among the magnetic impurities diluted therein. The microscopic structure and defect distribution are of crucial importance; and indeed, it has been shown that clustering, phase separation, and complex formation of the magnetic impurities, possibly involving other intrinsic or extrinsic defects, can dramatically alter the magnetic properties of a given sample. Detailed knowledge of the underlying short-range chemical and magnetic interactions, in turn, can be used to “design” new materials with target magnetic properties. This paper describes the Fermi-level dependence of these short-range chemical and magnetic interactions, i.e., how these interactions depend on defect charge states.
Phonons and defects in semiconductors and nanostructures: Phonon trapping, phonon scattering, and heat flow at heterojunctions
Authors: Estreicher S. K. , Gibbons T. M. , Kang By. , Bebek M. B.
Published: January 2014

Defects in semiconductors introduce vibrational modes that are distinct from bulk modes because they are spatially localized in the vicinity of the defect. Light impurities produce high-frequency modes often visible by Fourier-transform infrared absorption or Raman spectroscopy. Their vibrational lifetimes vary by orders of magnitude and sometimes exhibit unexpectedly large isotope effects. Heavy impurities introduce low-frequency modes sometimes visible as phonon replicas in photoluminescence bands. But other defects such as surfaces or interfaces exhibit spatially localized modes (SLMs) as well. All of them can trap phonons, which ultimately decay into lower-frequency bulk phonons. When heat flows through a material containing defects, phonon trapping at localized modes followed by their decay into bulk phonons is usually described in terms of phonon scattering: defects are assumed to be static scattering centers and the properties of the defect-related SLMs modes are ignored. These dynamic properties of defects are important. In this paper, we quantify the concepts of vibrational localization and phonon trapping, distinguish between normal and anomalous decay of localized excitations, discuss the meaning of phonon scattering in real space at the atomic level, and illustrate the importance of phonon trapping in the case of heat flow at Si/Ge and Si/C interfaces.
Metallic beam developments for the SPIRAL 2 project
Authors: Barué C. , Canet C. , Dupuis M. , Flambard J. L. , Frigot R. , Jardin P. , Lamy T. , Lemagnen F. , Maunoury L. , Osmond B. , Peaucelle C. , Sole P. , Thuillier T.
Published: January 2014

The SPIRAL 2 facility, currently under construction, will provide either stable or radioactive beams at high intensity. In addition to the high intensity of stable beams, high charge states must be produced by the ion source to fulfill the RFQ LINAC injection requirements: Q/A = 1/3 at 60 kV ion source extraction voltage. Excepting deuterons and hydrogen, most of the stable beam requests concern metallic elements. The existing 18 GHz electron cyclotron resonance ion source (ECRIS) Phoenix V2 designed at LPSC Grenoble has been used for the tests and will be the source for the SPIRAL 2 commissioning. The tests performed at LPSC for calcium (40Ca14+ and 40Ca16+), nickel (58Ni19+), and sulfur (32S11+) are described and discussed. Due to the very high charge states required, the oven method has been chosen. An intensity of 1 pμA has been reached for those elements. The performance and the beam stability have been studied using different buffer gases, and some ionization efficiency preliminary results are given.
Canonical form of the Hartree-Fock orbitals in open-shell systems
Authors: Plakhutin Boris N. , Davidson Ernest R.
Published: January 2014

This work compares different approaches to deriving Hartree-Fock (HF) orbitals and orbital energies for open-shell systems. We compare the basic HF equations underlying both the classic open-shell HF methods, which are the restricted open-shell HF (ROHF) and unrestricted HF (UHF) methods, and a number of the novel (amended) versions of these methods. The main attention is paid to a treatment of the validity of Brillouin's and Koopmans’ theorems in the amended versions. We show that these two theorems are fully obeyed only in the special (canonical) form of the ROHF method developed by Plakhutin et al. [J. Chem. Phys. 125, 204110 (2006)] and by Davidson and Plakhutin [J. Chem. Phys. 132, 184110 (2010)], while each of the amended UHF methods suffers from some deficiencies inherent to original UHF and ROHF methods. To compare the HF orbitals derived by different methods in two different forms – DODS (different orbitals for different spins) and SODS (the same orbitals for different spins), we develop the new ROHF-DODS method which combines the use of DODS underlying amended UHF methods and the main advantage of the canonical ROHF method which is a fulfillment of the rigorous Koopmans’ conditions. The main result of this work is that the orbitals and orbital energies derived with the new ROHF-DODS method appear identical to those derived with the canonical ROHF method based on the use of SODS. A discussion is presented of some related problems arising in open-shell HF methods such as a violation of the Aufbau principle.
Transient growth of droplet instabilities in a stream
Authors: Jalaal M. , Mehravaran K.
Published: January 2014

Droplet deformation is the first stage of all aerodynamically induced-breakups, considerably affecting the characteristics of the atomization. In the present study, using an adaptive volume of fluid method, two and three-dimensional direct numerical simulations have been performed to understand droplet deformation. A high Reynolds number and a range of relatively high Weber numbers are chosen, addressing the shear breakup of droplets in a stream. The study is focused on the initiation and growth of instabilities over the droplet. The role of Kelvin-Helmholtz and Rayleigh-Taylor instabilities in wave formation and azimuthal transverse modulation are shown and the obtained results for the most amplified wave-numbers are compared with instability theories for zero and non-zero vorticity layers. The present results for the most amplified wave-numbers and deformation topologies are in good agreement with the previous experimental results.
Composite and shaped pulses for efficient and robust pumping of disconnected eigenstates in magnetic resonance
Authors: Theis T. , Feng Y. , Wu T. , Warren W. S.
Published: January 2014

Hyperpolarization methods, which can enhance nuclear spin signals by orders of magnitude, open up important new opportunities in magnetic resonance. However, many of these applications are limited by spin lattice relaxation, which typically destroys the hyperpolarization in seconds. Significant lifetime enhancements have been found with “disconnected eigenstates” such as the singlet state between a pair of nearly equivalent spins, or the “singlet-singlet” state involving two pairs of chemically equivalent spins; the challenge is to populate these states (for example, from thermal equilibrium magnetization or hyperpolarization) and to later recall the population into observable signal. Existing methods for populating these states are limited by either excess energy dissipation or high sensitivity to inhomogeneities. Here we overcome the limitations by extending recent work using continuous-wave irradiation to include composite and adiabatic pulse excitations. Traditional composite and adiabatic pulses fail completely in this problem because the interactions driving the transitions are fundamentally different, but the new shapes we introduce can move population between accessible and disconnected eigenstates over a wide range of radio-frequency (RF) amplitudes and offsets while depositing insignificant amounts of power.
Magnetic susceptibility and magnetic resonance measurements of the moisture content and hydration condition of a magnetic mixture material
Authors: Tsukada K. , Kusaka T. , Saari M. M. , Takagi R. , Sakai K. , Kiwa T. , Bito Y.
Published: January 2014

We developed a magnetic measurement method to measure the moisture content and hydration condition of mortar as a magnetic mixture material. Mortar is a mixture of Portland cement, sand, and water, and these materials exhibit different magnetic properties. The magnetization–magnetic field curves of these components and of mortars with different moisture contents were measured, using a specially developed high-temperature-superconductor superconducting quantum interference device. Using the differences in magnetic characteristics, the moisture content of mortar was measured at the ferromagnetic saturation region over 250 mT. A correlation between magnetic susceptibility and moisture content was successfully established. After Portland cement and water are mixed, hydration begins. At the early stage of the hydration/gel, magnetization strength increased over time. To investigate the magnetization change, we measured the distribution between bound and free water in the mortar in the early stage by magnetic resonance imaging (MRI). The MRI results suggest that the amount of free water in mortar correlates with the change in magnetic susceptibility.
The magnetostriction and its ratio to hysteresis for Tb-Dy-Ho-Fe alloys
Authors: Wang Bowen , Lv Yan , Li Guolu , Huang Wenmei , Sun Ying , Cui Baozhi
Published: January 2014

The x(Tb0.15Ho0.85Fe2) + (1 − x)(Tb0.3Dy0.7Fe2) alloys were prepared in an arc furnace under high purity argon. The as-cast samples wrapped in Mo foil were sealed in a silica tube filled with high purity argon. The static measurement of magnetostriction (λ//, λ⊥) was made by standard strain gauge, and the magnetization M was measured by a vibrating sample magnetometer. It is found that the magnetostriction λ// of x(Tb0.15Ho0.85Fe2) + (1 − x)(Tb0.3Dy0.7Fe2) alloys decreases with increasing x and it does from 880 × 10−6 for x = 0 to 210 × 10−6 for x = 0.9 at the magnetic field of 640 kA/m. The ratio (λ///Wh) of magnetostriction to hysteresis exhibits a peak when x = 0.1, and it means that the Tb0.285Dy0.63Ho0.085Fe2 (x = 0.1) alloy possesses both large magnetostriction and small magnetostrictive hysteresis.
Structural and magnetic properties of epitaxial Heusler alloy Fe2Cr0.5Co0.5Si
Authors: Wang Yu-Pu , Han Gu-Chang , Lu Hui , Qiu Jinjun , Yap Qi-Jia , Teo Kie-Leong
Published: January 2014

This paper reports the study of structural and magnetic properties of Heusler alloy Fe2Cr0.5Co0.5Si (FCCS) thin film and its tunnel magnetoresistance (TMR) effect. The smooth quaternary Heusler alloy FCCS film with surface roughness of rms value of 0.25 nm measured by atomic force microscopy and partial L21 phase was obtained by magnetron sputtering at room temperature followed by in-situ annealing at 400 °C. The saturation magnetization and coercivity of FCCS are 410 emu/cm3 and 20 Oe, respectively. The magnetic tunnel junctions (MTJs) using FCCS as free layer were studied in detail as a function of post-annealing temperature. A TMR ratio of 15.6% has been achieved with 300 °C post-annealing. This is about twice the highest TMR ratio obtained in MTJs using Fe2CrSi. The enhancement of TMR ratio can be attributed to the successful tuning of the Fermi level of Fe2CrSi close to the center of the minority band gap by Co-doping.
Radioactive ion beam transportation for the fundamental symmetry study with laser-trapped atoms
Authors: Arikawa Hiroshi , Ando S. , Aoki T. , Ezure S. , Harada K. , Hayamizu T. , Inoue T. , Ishikawa T. , Itoh M. , Kawamura H. , Kato K. , Kato T. , Uchiyama A. , Aoki T. , Furukawa T. , Hatakeyama A. , Hatanaka K. , Imai K. , Murakami T. , Nataraj H. S. , Sato T. , Shimizu Y. , Wakasa T. , Yoshida H. P. , Sakemi Y.
Published: January 2014

The search for the violation of the fundamental symmetry in a radioactive atom is the promising candidate for precision tests of the standard model and its possible extensions. The subtle signal arising from the symmetry violation is enhanced in heavy atoms, such as a francium (Fr). To realize high precision measurements, a large amount of radioactive isotopes is required. The Fr is produced via a nuclear fusion reaction using a melted gold target with a 18O primary beam at Cyclotron and Radioisotope Center, Tohoku University. The maximum extraction efficiency of the Fr ion was achieved at approximately 35%. The beam line consists of an electrostatic deflector, three electrostatic quadrupole triplets to the measurement area at 10 m away from the reaction point, and several beam diagnosis systems. We optimized parameters of the beam line.
Salting out the polar polymorph: Analysis by alchemical solvent transformation
Authors: Duff Nathan , Dahal Yuba Raj , Schmit Jeremy D. , Peters Baron
Published: January 2014

We computationally examine how adding NaCl to an aqueous solution with α- and γ-glycine nuclei alters the structure and interfacial energy of the nuclei. The polar γ-glycine nucleus in pure aqueous solution develops a melted layer of amorphous glycine around the nucleus. When NaCl is added, a double layer is formed that stabilizes the polar glycine polymorph and eliminates the surface melted layer. In contrast, the non-polar α-glycine nucleus is largely unaffected by the addition of NaCl. To quantify the stabilizing effect of NaCl on γ-glycine nuclei, we alchemically transform the aqueous glycine solution into a brine solution of glycine. The alchemical transformation is performed both with and without a nucleus in solution and for nuclei of α-glycine and γ-glycine polymorphs. The calculations show that adding 80 mg/ml NaCl reduces the interfacial free energy of a γ-glycine nucleus by 7.7 mJ/m2 and increases the interfacial free energy of an α-glycine nucleus by 3.1 mJ/m2. Both results are consistent with experimental reports on nucleation rates which suggest: J(α, brine) < J(γ, brine) < J(α, water). For γ-glycine nuclei, Debye-Hückel theory qualitatively, but not quantitatively, captures the effect of salt addition. Only the alchemical solvent transformation approach can predict the results for both polar and non-polar polymorphs. The results suggest a general “salting out” strategy for obtaining polar polymorphs and also a general approach to computationally estimate the effects of solvent additives on interfacial free energies for nucleation.
First order deformations of the Fourier matrix
Authors: Banica Teodor
Published: January 2014

The N × N complex Hadamard matrices form a real algebraic manifold CN. The singularity at a point H ∈ CN is described by a filtration of cones \documentclass[12pt]{minimal}\begin{document}$T^\times _HC_N\subset T^\circ _HC_N\subset T_HC_N\subset \widetilde{T}_HC_N$\end{document}TH×CN⊂TH∘CN⊂THCN⊂T̃HCN, coming from the trivial, affine, smooth, and first order deformations. We study here these cones in the case where H = FN is the Fourier matrix, (wij) with w = e2πi/N, our main result being a simple description of \documentclass[12pt]{minimal}\begin{document}$\widetilde{T}_HC_N$\end{document}T̃HCN. As a consequence, the rationality conjecture \documentclass[12pt]{minimal}\begin{document}$dim_\mathbb {R}(\widetilde{T}_HC_N)=dim_\mathbb {Q}(\widetilde{T}_HC_N\cap M_N(\mathbb {Q}))$\end{document}dimR(T̃HCN)=dimQ(T̃HCN∩MN(Q)) holds at H = FN.
Single-photon emission from cubic GaN quantum dots
Authors: Kako Satoshi , Holmes Mark , Sergent Sylvain , Bürger Matthias , As Donat J. , Arakawa Yasuhiko
Published: January 2014

We report the demonstration of single-photon emission from cubic GaN/AlN quantum dots grown by molecular beam epitaxy. We have observed spectrally clean and isolated emission peaks from these quantum dots. Clear single-photon emission was detected by analyzing one such peak at 4 K. The estimated g(2)[0] value is 0.25, which becomes 0.05 when corrected for background and detector dark counts. We have also observed the single-photon nature of the emission up to 100 K (g(2)[0] = 0.47). These results indicate that cubic GaN quantum dots are possible candidates for high-temperature operating UV single-photon sources with the possibility of integration into photonic nanostructures.
Microwave noise characterization of graphene field effect transistors
Authors: Tanzid M. , Andersson M. A. , Sun J. , Stake J.
Published: January 2014

The microwave noise parameters of graphene field effect transistors (GFETs) fabricated using chemical vapor deposition graphene with 1  μm gate length in the 2 to 8 GHz range are reported. The obtained minimum noise temperature (Tmin) is 210 to 610 K for the extrinsic device and 100 to 500 K for the intrinsic GFET after de-embedding the parasitic noise contribution. The GFET noise properties are discussed in relation to FET noise models and the channel carrier transport. Comparison shows that GFETs can reach similar noise levels as contemporary Si CMOS technology provided a successful gate length scaling is performed.
Ultrafast all-optical switching and error-free 10 Gbit/s wavelength conversion in hybrid InP-silicon on insulator nanocavities using surface quantum wells
Authors: Bazin Alexandre , Lenglé Kevin , Gay Mathilde , Monnier Paul , Bramerie Laurent , Braive Rémy , Beaudoin Grégoire , Sagnes Isabelle , Raj Rama , Raineri Fabrice
Published: January 2014

Ultrafast switching with low energies is demonstrated using InP photonic crystal nanocavities embedding InGaAs surface quantum wells heterogeneously integrated to a silicon on insulator waveguide circuitry. Thanks to the engineered enhancement of surface non radiative recombination of carriers, switching time is obtained to be as fast as 10 ps. These hybrid nanostructures are shown to be capable of achieving systems level performance by demonstrating error free wavelength conversion at 10 Gbit/s with 6 mW switching powers.
Hybrid plasmonic waveguide in a metal V-groove
Authors: Chen Zhao-xian , Wu Zi-jian , Ming Yang , Zhang Xue-jin , Lu Yan-qing
Published: January 2014

We propose and investigate a type of hybrid plasmonic waveguide in a metal V-groove. A high-permittivity nanowire was placed in the metal channel covered with a dielectric film of lower permittivity. Deeper sub-wavelength confinement and much longer propagation distance were achieved in comparison with conventional channel plasmonic waveguides. The overall performance was improved as compared with the conventional hybrid plasmonic structure based on a flat metal surface. Finite element analysis showed that both the mode propagation and field profile can be adjusted by changing the nanowire radius and film thickness. Some benefits, such as a reduced scattering loss caused by the surface roughness, are also expected owing to the unique mode profile. The proposed approach has potential for application in high-level photonic integration.
Nuclear magnetic resonance takes a reaction’s temperature
Authors: Wilson R. Mark
Published: January 2014

A new technique exploits the inverse relation between temperature and the linewidth of a proton resonance.
Explaining our two-faced Moon
Authors: Wilson R. Mark
Published: January 2014

New computer simulations of asteroid impacts on the Moon reveal why the basins on its near side are almost twice as wide as those on its far side.
Scoping out the North American continent, 10 years on
Authors: Feder Toni
Published: January 2014

Designed as a sort of inward-looking telescope, EarthScope is addressing longstanding questions and making serendipitous findings.
Tasting music like wine: Sensory evaluation of concert halls
Authors: Lokki Tapio
Published: January 2014

How do acoustics affect a concertgoer’s experience? With the right tools, we can learn a lot by asking listeners to tell us in their own words.
Political Satire as an Index of Press Freedom: A Review of Political Satire in the Iranian Press during the 2000s
Authors: Farjami Mahmud
Published: January 2014

Political satire has had a prominent part to play in the social and political sphere of journalism in Iran since the appearance of an independent press in the country at the beginning of the twentieth century. This paper examines the problems of political satire in the Iranian press during the 2000s with respect to their historical context during the past century. The paper argues that, addressing the essential relationship between satire and criticism, and the primary role that criticism has in the freedom of press, what happened to political satire and satirists in Iran can be seen as an index of the freedom of the press and journalistic expression for an era.
Age, Growth, and Reproductive Biology of Cownose Rays in Chesapeake Bay
Authors: Fisher Robert A. , Call Garrett C. , Grubbs R. Dean
Published: January 2014

The Cownose Ray Rhinoptera bonasus is an opportunistic predator of benthic invertebrates and has had a long history of negative interactions with commercial shellfish industries. Most recently, Cownose Rays have been implicated in negatively affecting the recovery of bay scallop Argopecten irradians stocks in North Carolina and oyster restoration and commercial aquaculture efforts in Chesapeake Bay. A mitigation attempt to decrease predation on shellfish has resulted in an unregulated fishery for Cownose Rays. Cownose Ray life history suggests that they are highly susceptible to overexploitation. We determined age, growth, and size at maturity for Cownose Rays collected in Chesapeake Bay. In total, 694 rays were used for the study: 246 males ranging in size from 30.0 to 98.0 cm disc width (DW) and 448 females ranging from 30.0 to 110.5 cm DW. The oldest individual observed was a female (107 cm DW) estimated at age 21. Our data suggested that Cownose Rays grow considerably faster during the first few years than has been previously reported, thus producing higher estimates of the growth coefficient k. The best-fit growth models (three-parameter von Bertalanffy models) estimated k-values of 0.2741 for males and 0.1931 for females. The large sample size and inclusion of many older animals (n = 119 rays over age 10) resulted in theoretical maximum size estimates that matched the observed sizes well. The median size at 50% maturity was 85–86 cm DW for males and females (corresponding to ages of ∼6–7 for males and ∼7–8 for females). Fecundity in Cownose Rays was typically one embryo per mature female, with a gestation period of 11–12 months. Our study confirms that the Cownose Ray is a K-selected species with late maturity, long gestation, and low reproductive potential, indicating that it could be highly susceptible to overexploitation.

Received February 28, 2013; accepted June 3, 2013
A Novel Approach to Surveying Sturgeon Using Side-Scan Sonar and Occupancy Modeling
Authors: Flowers H. Jared , Hightower Joseph E.
Published: January 2014

Technological advances represent opportunities to enhance and supplement traditional fisheries sampling approaches. One example with growing importance for fisheries research is hydroacoustic technologies such as side-scan sonar. Advantages of side-scan sonar over traditional techniques include the ability to sample large areas efficiently and the potential to survey fish without physical handling—important for species of conservation concern, such as endangered sturgeons. Our objectives were to design an efficient survey methodology for sampling Atlantic Sturgeon Acipenser oxyrinchus by using side-scan sonar and to develop methods for analyzing these data. In North Carolina and South Carolina, we surveyed six rivers thought to contain varying abundances of sturgeon by using a combination of side-scan sonar, telemetry, and video cameras (i.e., to sample jumping sturgeon). Lower reaches of each river near the saltwater–freshwater interface were surveyed on three occasions (generally successive days), and we used occupancy modeling to analyze these data. We were able to detect sturgeon in five of six rivers by using these methods. Side-scan sonar was effective in detecting sturgeon, with estimated gear-specific detection probabilities ranging from 0.2 to 0.5 and river-specific occupancy estimates (per 2-km river segment) ranging from 0.0 to 0.8. Future extensions of this occupancy modeling framework will involve the use of side-scan sonar data to assess sturgeon habitat and abundance in different river systems.

Received January 15, 2013; accepted June 10, 2013
The Distribution of Larval Fishes of the Charleston Gyre Region off the Southeastern United States in Winter Shaped by Mesoscale, Cyclonic Eddies
Authors: Govoni J. J. , Hare J. A. , Davenport E. D.
Published: January 2014

Serial, cyclonic, mesoscale eddies arise just north of the Charleston Bump, a topographical rise on the continental slope and Blake Plateau, and characterize the U.S. outer shelf and upper slope in the region of the Charleston Gyre. This region was transected during the winters of 2000, 2001, and 2002, and hydrographic data and larval fishes were collected. The hydrodynamics of the cyclonic eddies of the Charleston Gyre shape the distribution of larval fishes by mixing larvae from the outer continental shelf and the Gulf Stream and entraining them into the eddy circulation at the peripheral margins, the wrap-around filaments. Over all years and transects (those that intercepted eddies and those that did not), chlorophyll a concentrations, zooplankton displacement volumes, and larval fish concentrations were positively correlated. Chlorophyll a concentrations were highest in filaments that wrapped around eddies, and zooplankton displacement volumes were highest in the continental shelf–Gulf Stream–frontal mix. Overall, the concentration of all larval fishes declined from inshore to offshore with highest concentrations occurring over the outer shelf. Collections produced larvae from 91 fish families representing continental shelf and oceanic species. The larvae of shelf-spawned fishes—Atlantic Menhaden Brevoortia tyrannus, Round Herring Etrumeus teres, Spot Leiostomus xanthurus, and Atlantic Croaker Micropogonias undulatus—were most concentrated over the outer shelf and in the continental shelf–Gulf Stream–frontal mix. The larvae of ocean-spawned fishes—lanternfishes, bristlemouths, and lightfishes—were more evenly dispersed in low concentrations across the outer shelf and upper slope, the highest typically in the Gulf Stream and Sargasso Sea, except for lightfishes that were highest in the continental shelf–Gulf Stream–frontal mix. Detrended correspondence analysis rendered groups of larval fishes that corresponded with a gradient between the continental shelf and Gulf Stream and Sargasso Sea. Eddies propagate northeastward with a residence time on the outer shelf and upper slope of ∼1 month, the same duration as the larval period of most fishes. The pelagic habitat afforded by eddies and fronts of the Charleston Gyre region can be exploited as nursery areas for feeding and growth of larval fishes within the southeastern Atlantic continental shelf ecosystem of the U.S. Eddies, and the nursery habitat they provide, translocate larvae northeastward.

Received March 18, 2013; accepted June 21, 2013
Understanding Smolt Survival Trends in Sockeye Salmon
Authors: Irvine James R. , Akenhead Scott A.
Published: January 2014

Many populations of Sockeye Salmon Oncorhynchus nerka in the eastern North Pacific Ocean experienced significant productivity declines that began about 1990, but there is no consensus on the mechanisms responsible. To better understand Sockeye Salmon survival trends, we examined the 50-year time series for two age-classes of Sockeye Salmon smolts from Chilko Lake in central British Columbia. Arranging survival time series for both age-classes by ocean entry year and combining them, weighted by a proxy model of sampling variance, reduced the sampling variance in the original age-1 smolt survivals sufficiently to indicate a linear trend of increasing survival from 1960 to 1990 that suddenly changed at or near 1991 to a lower and declining trend from 1992 to 2008. Neither density nor mean length influenced smolt survival. Returns in a given year were not good predictors of siblings returning in subsequent years. Time spent at sea increased linearly beginning around 1970. Although smolt survivals differed between ecosystem regimes, there was only the one clear pattern break about 1991. To improve our understanding of mechanisms, survival trends were compared with environmental indices that included catches and hatchery releases of potentially competing salmon from around the North Pacific Ocean. Smolt survivals were more similar to abundance indices of Sockeye Salmon, Chum Salmon O. keta, and Pink Salmon O. gorbuscha than to indices of global, regional, or local ocean climate. Our results are consistent with the hypothesis that salmon productivity in the North Pacific declined soon after 1990. We present a simple model to illustrate how increased competition at sea, related to the release of large numbers of hatchery salmon, in conjunction with changes in ocean productivity, may have played a significant role in improving Sockeye Salmon survivals while reducing their growth before 1991. After 1991, these factors may have acted to reduce survivals while the growth of survivors showed no effect.

Received February 8, 2013; accepted July 24, 2013
First Report of Plant-Parasitic Nematodes on Seashore Paspalum (Paspalum vaginatum) in Barbados
Authors: McGroary P. C. , Cisar J. L. , Giblin-Davis R. M. , Ruiz O. F. , Nangle E. J.
Published: January 2014

Seashore paspalum (Paspalum vaginatum Swartz) is a warm-season perennial turfgrass commonly used for golf courses that are grown in saline environments or using saline water for irrigation. However, seashore paspalum is also grown in non-saline conditions due to its low fertilizer and water requirements (2). In Barbados, on a newly constructed golf course, seashore paspalum ‘Sea Isle Supreme’ sprigs were imported from Georgia (United States) and were planted over 2006 and 2007 on greens, tees, fairways, and rough. Golf greens were constructed following the United States Golf Association Green Section (Far Hills, NJ) putting green guidelines. Tees and fairways were constructed using native soil. Two years after the grow-in, the putting greens began to exhibit irregular chlorotic patches, followed by gradual thinning and decline of turfgrass stand density in those areas. Additionally, turfgrass roots sampled from those symptomatic patches appeared to be abbreviated compared to non-symptomatic areas of the greens. A survey was conducted in May 2013 to determine if plant-parasitic nematodes were present coinciding with the observed symptoms, which were similar to those described in a previous report (3). Consequently, two samples were collected from each green with a total of four greens sampled. Each sample consisted of 20 soil cores (15 cm depth × 1.2 cm in diameter) from either areas of the greens showing symptoms or from non-symptomatic areas. Nematodes were extracted from 100 cm3 soil samples using a modified centrifugal-sugar flotation technique (4). No plant parasitic nematodes were present in any of the samples from the non-symptomatic areas. Three genera of plant parasitic nematodes were found in all the samples from the symptomatic areas: Helicotylenchus. Mesocriconema, and Pratylenchus. Nematode populations of these genera averaged 30, 60, and 200 nematodes per 100 cm3, respectively. Populations of the genera Helicotylenchus and Mesocriconema were below the action threshold levels for seashore paspalum used by the University of Florida Nematode Assay Laboratory (1). Currently, no threshold exists for Pratylenchus for seashore paspalum. Conversely, the genera Helicotylenchus. Mesocriconema, and Pratylenchus were found associated with the irregular chlorotic patches but not with the non-symptomatic areas. To our knowledge, this is the first report of plant parasitic nematodes associated with seashore paspalum maintained as putting greens in Barbados.

References: (1) W. T. Crow. Nematode management for golf courses in Florida. EDIS. Accessed 31 July 2013 from: http://edis.ifas.ufl.edu/in124 , 2001. (2) R. R. Duncan and R. N. Carrow. Seashore Paspalum: The Environmental Turfgrass. John Wiley & Sons, Inc., Hoboken, New Jersey, 2000. (3) A. C. Hixson and W. T. Crow. Plant Dis. 88:680, 2004. (4) W. R. Jenkins. Plant Dis. Rep. 48:692, 1964.
Persistent High Levels of IgM Antiphospholipid Antibodies in a Patient with Recurrent Pregnancy Losses and Rheumatoid Arthritis
Authors: Ota Kuniaki , Dambaeva Svetlana , Lee Jennifer , Gilman‐Sachs Alice , Beaman Kenneth , Kwak‐Kim Joanne
Published: January 2014

Objective

Recurrent pregnancy losses (RPL) and unexplained infertility (UI) are often associated with the presence of antiphospholipid antibodies (APA). We report one case with RPL, UI, and persistent IgM APA without B‐cell isotype switch.

Method of study

(i) A case report of a woman with RPL and UI who eventually developed rheumatoid arthritis and B‐cell phenotype study of the case and controls by flow cytometric analysis; (ii) a retrospective cohort study of 1067 subjects with APA test.

Results

A 44‐year‐old woman with a history of RPL and UI was revealed to have high levels of APA, primarily of IgM isotype: IgM autoantibodies were specific to cardiolipin, phosphatidylglycerol, phosphatidylserine, and phosphatidylinositol. The monitoring of the patient's serological characteristics for 28 months did not reveal the development of IgG APA. B‐cell phenotype analysis revealed decreased switched and double negative memory B cells and increased non‐switched memory B cells in comparison with normal controls and reported ranges.

A retrospective analysis of APA test revealed that total five patients (5/1067, 0.47%) with similar persistent IgM‐only pattern were detected.

Conclusion

Persistent IgM APA without isotype switch may be a rare variant form of APA manifestation, which is associated with dysregulated B‐cell subsets.
The efficacy of peri‐operative interventions to decrease postoperative delirium in non‐cardiac surgery: a systematic review and meta‐analysis.
Authors: Moyce Z. , Rodseth R. N. , Biccard B. M.
Published: January 2014

The purpose of this meta‐analysis was to determine the efficacy of peri‐operative interventions in decreasing the incidence of postoperative delirium. An electronic search of four databases was conducted. The Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines were adhered to. We included randomised controlled trials of non‐cardiac surgery with a peri‐operative intervention and that reported postoperative delirium, and identified 29 trials. Meta‐analysis revealed that peri‐operative geriatric consultation (OR 0.46, 95% CI 0.32–0.67) and lighter anaesthesia (OR 2.66, 95% CI 1.27–5.56) were associated with a decreased incidence of postoperative delirium. For the other interventions, the point estimate suggested possible protection with prophylactic haloperidol (OR 0.62, 95% CI 0.36–1.05), bright light therapy (OR 0.20, 95% CI 0.03–1.19) and general as opposed to regional anaesthesia (OR 0.76, 95% CI 0.47–1.23). This meta‐analysis has shown that peri‐operative geriatric consultations with multicomponent interventions and lighter anaesthesia are potentially effective in decreasing the incidence of postoperative delirium.
Early childhood malaria prevention and children's patterns of school leaving in the Gambia
Authors: Zuilkowski Stephanie S. , Jukes Matthew C. H.
Published: January 2014

Background

Early childhood malaria is often fatal, but its impact on the development and education of survivors has not received much attention. Malaria impacts cognitive development in a number of ways that may impact later educational participation.

Aims

In this study, we examine the long‐term educational effects of preventing early childhood malaria. Does intermittent preventive treatment (IPT) during early childhood reduce the risk of dropout? If so, does this effect vary by school type – government school versus madrassa?

Sample

We use data from a 2001 follow‐up of a 1985–1987 malaria prevention randomized controlled trial in the Gambia. The sample consists of 562 youth born between 1981 and 1986.

Methods

We use discrete‐time survival analysis to identify the impact of the intervention on dropout risk over time.

Results

We find that IPT has a positive impact on dropout for government school students, but not for madrassa attendees. The difference was striking: in government schools, the odds of dropout in the treatment group were one third of those in the control group.

Conclusions

Our findings suggest that preventing early childhood malaria may reduce dropout at a relatively low cost. In this intervention, the drugs cost less than one dollar per year per child. While IPT is no longer practised in many countries due to concerns over drug resistance, these results support the conclusion that any type of effective malaria control programme protecting young children, such as consistent and correct use of bed nets, could improve educational attainment in areas where malaria is prevalent.
Engineering the alternative oxidase gene to better understand and counteract mitochondrial defects: state of the art and perspectives
Authors: El‐Khoury Riyad , Kemppainen Kia K , Dufour Eric , Szibor Marten , Jacobs Howard T , Rustin Pierre
Published: January 2014

Mitochondrial disorders are nowadays recognized as impinging on most areas of medicine. They include specific and widespread organ involvement, including both tissue degeneration and tumour formation. Despite the spectacular progresses made in the identification of their underlying molecular basis, effective therapy remains a distant goal. Our still rudimentary understanding of the pathophysiological mechanisms by which these diseases arise constitutes an obstacle to developing any rational treatments. In this context, the idea of using a heterologous gene, encoding a supplemental oxidase otherwise absent from mammals, potentially bypassing the defective portion of the respiratory chain, was proposed more than 10 years ago. The recent progress made in the expression of the alternative oxidase in a wide range of biological systems and disease conditions reveals great potential benefit, considering the broad impact of mitochondrial diseases. This review addresses the state of the art and the perspectives that can be now envisaged by using this strategy.

Linked Articles

This article is part of a themed issue on Mitochondrial Pharmacology: Energy, Injury & Beyond. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2014.171.issue‐8
Increased CYP24A1 expression is associated with BRAFV600E mutation and advanced stages in papillary thyroid carcinoma
Authors: Zou Minjing , BinHumaid Faisal S. , Alzahrani Ali S. , Baitei Essa Y. , Al‐Mohanna Futwan A. , Meyer Brian F. , Shi Yufei
Published: January 2014

Objective

1α, 25(OH)2D3 (calcitriol), the active form of vitamin D, has been shown to exert antiproliferative effects in many cancers. Overexpression of CYP24A1, the primary vitamin D‐inactivating enzyme, is also observed in a variety of human cancers, thus potentially neutralizing the antitumour effect of 1α, 25(OH)2D3. This study investigates the expression of CYP24A1 and the effect of BRAFV600E on its expression in thyroid cancer.

Methods

We investigated 60 papillary thyroid carcinoma (PTC) specimens for CYP24A1 expression and its association with BRAF mutation and disease progression. CYP24A1 expression was measured by real‐time RT‐PCR, and BRAFV600E mutation was detected by PCR‐DNA sequencing analysis. The interaction between BRAFV600E and CYP24A1 expression was determined by Western blot analysis and real‐time RT‐PCR.

Results

CYP24A1 expression was increased in PTC as compared to benign multinodular goitre. The expression was further increased in stage III and IV tumours. There is a strong correlation between CYP24A1 overexpression and BRAFV600E mutation (P < 0·01). In thyroid cancer cell lines expressing BRAFV600E, CYP24A1 expression was significantly higher when compared to those without BRAFV600E expression. BRAFV600E transgene expression in CAL62 cell line can induce CYP24A1 expression. Furthermore, BRAFV600E inhibitor PLX4720 can significantly down‐regulate CYP24A1 expression and enhance the antiproliferative effects of calcitriol in thyroid cancer cell lines.

Conclusion

CYP24A1 overexpression is a poor prognostic indicator for PTC and may reflect BRAFV600E mutation and MARK activation. The crosstalk between vitamin D and MAPK signalling pathways results in resistance to calcitriol‐mediated antitumour effects, and the resistance can be reversed by BRAFV600E inhibitor PLX4720.
Phylogeny of harvestmen family Gonyleptidae inferred from a multilocus approach (Arachnida: Opiliones)
Authors: Pinto‐da‐Rocha Ricardo , Bragagnolo Cibele , Marques Fernando P. L. , Antunes Junior Manuel
Published: January 2014

Gonyleptidae is the second most diverse harvestmen family and the most studied in terms of morphology, behaviour, and ecology. Despite this, few phylogenetic studies have focused on gonyleptids, and those are based on a very limited number of taxa. We addressed this gap by constructing a phylogenetic hypothesis of the family using 101 taxa from all 16 gonyleptid subfamilies and four mitochondrial and nuclear loci (COI, 28SrRNA, 12SrRNA, and 16SrRNA). These were analysed under parsimony and likelihood optimality criteria (and using direct optimization for the former). Relationships among Gonyleptoidea and within each subfamily of Gonyleptidae were largely congruent between parsimony and maximum‐likelihood approaches. Taxonomic actions from our phylogeny include the following: Tricommatidae, new status, is restored as a family; Metasarcidae, new status, is recognized as a family and considered sister to the Cosmetidae; and Cranainae and Manaosbiinae are suggested as members of Gonyleptidae, restoring Roewer's concept of the family. Within Gonyleptidae, the “K92” group—composed of Sodreaninae, Caelopyginae, Hernandariinae, Progonyleptoidellinae, and Gonyleptinae—forms a clade, although the latter two subfamilies are not monophyletic. The genusParampheresis here transferred to Caelopyginae, and “Multumbo”dimorphicusto Gonyleptinae. Gonyleptidae is characterized by the presence of a ventral process on the penis glans and a bifid apophysis on the male coxa IV. The long‐legged Mitobatinae can be considered monophyletic only if some short‐legged pachylines are included, or if we assume that elongate legs arose twice independently (in the true mitobatine genera and inLongiperna). Pachylinae, the most diverse gonyleptid subfamily, represents several distinct lineages. We further conclude that the traditional use of a small set of morphological characters in the systematics of Gonyleptidae is unable to explain the complex evolution of the family.
Hybridization increases invasive knotweed success
Authors: Parepa Madalin , Fischer Markus , Krebs Christine , Bossdorf Oliver
Published: January 2014

Hybridization is one of the fundamental mechanisms by which rapid evolution can occur in exotic species. If hybrids show increased vigour, this could significantly contribute to invasion success. Here, we compared the success of the two invasive knotweeds, Fallopia japonica and F. sachalinensis, and their hybrid, F. × bohemica, in competing against experimental communities of native plants. Using plant material from multiple clones of each taxon collected across a latitudinal gradient in Central Europe, we found that knotweed hybrids performed significantly better in competition with a native community and that they more strongly reduced the growth of the native plants. One of the parental species, F. sachalinensis, regenerated significantly less well from rhizomes, and this difference disappeared if activated carbon was added to the substrate, which suggests allelopathic inhibition of F. sachalinensis regeneration by native plants. We found substantial within‐taxon variation in competitive success in all knotweed taxa, but variation was generally greatest in the hybrid. Interestingly, there was also significant variation within the genetically uniform F. japonica, possibly reflecting epigenetic differences. Our study shows that invasive knotweed hybrids are indeed more competitive than their parents and that hybridization increased the invasiveness of the exotic knotweed complex.
Effects of straw carbon input on carbon dynamics in agricultural soils: a meta‐analysis
Authors: Liu Chang , Lu Meng , Cui Jun , Li Bo , Fang Changming
Published: January 2014

Straw return has been widely recommended as an environmentally friendly practice to manage carbon (C) sequestration in agricultural ecosystems. However, the overall trend and magnitude of changes in soil C in response to straw return remain uncertain. In this meta‐analysis, we calculated the response ratios of soil organic C (SOC) concentrations, greenhouse gases (GHGs) emission, nutrient contents and other important soil properties to straw addition in 176 published field studies. Our results indicated that straw return significantly increased SOC concentration by 12.8 ± 0.4% on average, with a 27.4 ± 1.4% to 56.6 ± 1.8% increase in soil active C fraction. CO2 emission increased in both upland (27.8 ± 2.0%) and paddy systems (51.0 ± 2.0%), while CH4 emission increased by 110.7 ± 1.2% only in rice paddies. N2O emission has declined by 15.2 ± 1.1% in paddy soils but increased by 8.3 ± 2.5% in upland soils. Responses of macro‐aggregates and crop yield to straw return showed positively linear with increasing SOC concentration. Straw‐C input rate and clay content significantly affected the response of SOC. A significant positive relationship was found between annual SOC sequestered and duration, suggesting that soil C saturation would occur after 12 years under straw return. Overall, straw return was an effective means to improve SOC accumulation, soil quality, and crop yield. Straw return‐induced improvement of soil nutrient availability may favor crop growth, which can in turn increase ecosystem C input. Meanwhile, the analysis on net global warming potential (GWP) balance suggested that straw return increased C sink in upland soils but increased C source in paddy soils due to enhanced CH4 emission. Our meta‐analysis suggested that future agro‐ecosystem models and cropland management should differentiate the effects of straw return on ecosystem C budget in upland and paddy soils.