bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectroscopic observation of developing InAs quantum dots on GaAs ringlike-nanostructured templates
Authors: Mazur Yu. I. , Abu Waar Z. Y. , Mishima T. D. , Lee J. H. , Tarasov G. G. , Liang B. L. , Dorogan V. G. , Ware M. E. , Wang Zh. M. , Johnson M. B. , Salamo G. J.
Published: August 2008

Spectroscopic study of the InAs quantum dot (QD) formation in GaAs ringlike nanostructures is carried out. Ga droplet epitaxy is used to form GaAs ringlike nanostructures. Subsequently InAs is deposited to obtain InAs QDs by self-assembly inside the holes of the nanostructures. Regularly spaced bands in the photoluminescence spectra exhibit state filling properties under increased excitation power. However, it is demonstrated that these bands do not represent excited states of a single ensemble of dots, but are separate ensembles with individual ground state energies, which are coupled through the GaAs ring structure on which they form. The most likely cause of these uniformly spaced ensemble energies is monolayer differences in the effective height of the dots. Temperature, excitation power density, and time dependent photoluminescence measurements are used to demonstrate the significance of the interdot coupling. The photoluminescent properties of these novel nanostructures make them candidates for optoelectronic applications.
Texturing Nd–Fe–B magnets under high magnetic field
Authors: Rivoirard S. , Barthem V. M. T. S. , Bres R. , Beaugnon E. , de Miranda P. E. V. , Givord D.
Published: August 2008

An original approach is explored in the preparation of anisotropic hard magnetic alloys. This constitutes a proof of principle toward the preparation of anisotropic bonded magnets. Nd–Fe–B ribbons (50% Nd2Fe14B+50% Nd–Cu alloy), constituted of Nd2Fe14B grains embedded in a Nd–Cu eutectic matrix, were annealed under an applied magnetic field up to 16 T at various temperatures above the Nd–Cu melting temperature. The grain orientation mechanism is described in terms of a competition between the aligning magnetic field torque acting on the solid magnetic grains and the friction counter torque at the interface between the grains and the liquid matrix. The large temperature effect on the orientation behavior is attributed to the associated increase in the liquid phase volume fraction.
Influence of interface roughness on the performance of nanoparticulate zinc oxide field-effect transistors
Authors: Okamura Koshi , Mechau Norman , Nikolova Donna , Hahn Horst
Published: August 2008

Nanoparticulate zinc oxide is regarded as one of the most promising inorganic materials for printable field-effect transistors (FETs), which work in the n-channel enhancement mode, due to the compatibility with solution, low-temperature, and high throughput processes. Since nanoparticulate films are composed of the nanoparticles and their agglomerates, the roughness of the interface to the insulating layer, where the channel of the FETs is formed, is a critical issue. Thus, the influence of the interface roughness on the field-effect mobility of the FETs is investigated in conjunction with film roughness and capacitance analyses. The field-effect mobility increases almost by a factor of 50, from 2.0×10−4 to 8.4×10−3 cm2 V−1 s−1, even if the reduction in the average roughness of the films is as small as 1.7 nm.
A two-parameter variational multiscale method for large eddy simulation
Authors: Wanderer John , Oberai Assad A.
Published: August 2008

A two-parameter version of the variational multiscale (VMS) formulation with two Smagorinsky-type terms is proposed for the large eddy simulation of incompressible turbulent flows. One of the terms is the standard Smagorinsky eddy viscosity model that is applied to all resolved scales. The other is a fine scale addition that is constructed from the fine scale velocity field and is applied only to the fine scale equations. The new model is a generalization of the original variational multiscale model, which employs an eddy viscosity that acts only in the fine scales. The ability of the new two-parameter model to accurately predict sustained homogeneous isotropic turbulence is assessed by implementing it in a spectral code. Its performance is compared to the Smagorinsky model and the single-parameter VMS model. It is found that the single-parameter VMS model performs well at low to moderate Reynolds numbers, that the Smagorinsky model is more accurate at high Reynolds numbers, and that the new two-parameter VMS model performs well over the entire range. This performance is explained on the basis of the effective wavenumber dependent eddy viscosity for each model.
Surface property controllable multilayered gate dielectric for low voltage organic thin film transistors
Authors: Jo Sung Jin , Kim Chang Su , Kim Jong Bok , Kim Joohee , Lee Min Jung , Hwang Hyeon Seok , Baik Hong Koo , Kim Youn Sang
Published: August 2008

We report the effects of dielectric surface properties on the device performance of organic thin film transistors (OTFTs) using polymer/high-k oxide multilayered gate dielectrics. We systematically controlled the surface energy of the gate dielectric from very hydrophobic to very hydrophilic. The modified dielectric surface strongly affected the initial growth mechanism of pentacene and subsequently the performance of the OTFTs. The performance of the OTFTs with a higher surface energy was superior to that of the OTFTs with a lower surface energy.
High efficiency operation of butt joint line-defect-waveguide microlaser in two-dimensional photonic crystal slab
Authors: Zheng Wanhua , Ren Gang , Xing Mingxin , Chen Wei , Liu Anjin , Zhou Wenjun , Baba Toshihiko , Nozaki Kango , Chen Lianghui
Published: August 2008

Butt joint line-defect-waveguide microlasers are demonstrated on photonic crystal slabs with airholes in a triangular lattice. Such microlaser is designed to increase the output power from the waveguide edge directly. The output power is remarkably enhanced to 214 times higher by introducing chirped structure in the output waveguide. The lasing mode operates in the linear dispersion region of the output waveguide so that the absorption loss due to the band-edge effect is reduced. The laser resonance is illustrated theoretically using the finite difference time domain method. A practical high power efficiency of 20% is obtained in this microlaser.
Memory effect and negative differential resistance in tris-(8-hydroxy quinoline) aluminum/bathocuproine bilayer devices
Authors: Su Z. S. , Fung M. K. , Lee C. S. , Li W. L. , Lee S. T.
Published: August 2008

Memory effect and negative differential resistance (NDR) were observed in simple tris-(8-hydroxyquinoline) aluminum/bathocuproine (BCP) bilayer devices. The devices could be switched from a low conductance state to a high conductance state when a negative bias was applied and could be restored to an OFF state when a positive bias was applied beyond the NDR region. The memory effect is nonvolatile, and an ON/OFF ratio of over 103 was achieved. The memory effect was observed only in the presence of both Alq3 and BCP layers, and the NDR is attributed to the defects formed in the BCP layer upon evaporation of an Al cathode.
Nonlinear electrostatic drift waves in dense electron-positron-ion plasmas
Authors: Haque Q. , Mahmood S. , Mushtaq A.
Published: August 2008

The Korteweg–de Vries–Burgers (KdVB)-type equation is obtained using the quantum hydrodynamic model in an inhomogeneous electron-positron-ion quantum magnetoplasma with neutral particles in the background. The KdV-type solitary waves, Burgers-type monotonic, and oscillatory shock like solutions are discussed in different limits. The quantum parameter is also dependent on the positron concentration in dense multicomponent plasmas. It is found that both solitary hump and dip are formed and their amplitude and width are dependent on percentage presence of positrons in electron-ion plasmas. The height of the monotonic shock is decreased with the increase of positron concentration and it is independent of the quantum parameter in electron-positron-ion magnetized quantum plasmas. However, the amplitude of the oscillatory shock is dependent on positron concentration and quantum parameter in electron-positron-ion plasmas.
A linearized Fokker–Planck study of ion-eigenmodes in an unmagnetized pair-ion-electron plasma
Authors: Zhao Bin , Zheng Jian
Published: August 2008

Two kinds of ion-eigenmodes in an unmagnetized pair-ion-electron plasma, pair-ion-acoustic waves (PIAWs) and ion-Langmuir waves (ILWs), are investigated with Fokker–Planck description. The linearized negative- and positive-ion Fokker–Planck equations and linearized electron Vlasov equation are solved numerically as an eigenvalue problem. The frequencies and damping rates of PIAWs and ILWs are presented as a function of kλ, kλD, Te∕T, n−∕n+, where k is the wave number, λ is the mean-free path of the positive ion, λD is the positive ion Debye length, Te and T are electron and ion temperature, and n−∕n+ is the ratio of negative ion density to positive ion density. It is found that the dispersion relations of PIAWs and ILWs are sensitive to the strength of ion-ion collisions. As kλ increases, it is shown that PIAWs evolve into ILWs smoothly at small negative ion concentration. For large n−∕n+, PIAWs and ILWs, respectively, exist in a strong-collisional and rare-collisional region, and coexist in the intermediate regime at about kλ∼1. For comparison, hydrodynamic description and Vlasov description are also discussed. When the Landau damping is negligible, the two-fluid hydrodynamic description can give good results for ILWs if the friction forces between the negative and positive ions are included.
N
-type behavior of ferroelectric-gate carbon nanotube network transistor
Authors: Cheah Jun Wei , Shi Yumeng , Ong Hock Guan , Lee Chun Wei , Li Lain-Jong , Wang Junling
Published: August 2008

Carbon nanotube field effect transistor has attracted much attention recently and is a promising candidate for next generation nanoelectronics. Here, we report our study on a transistor using single wall carbon nanotube network as the channel and a ferroelectric film as the gate dielectric. The spontaneous polarization of ferroelectric materials offers nonvolatility and controllability of the surface charges. Modulation of >102 in the channel conductivity has been observed in the network-based transistor. Voltage pulses are used to control the transistor states; no continuous gate bias is needed. Furthermore, n-type behavior of the network channel is observed, which is attributed to a change in the Schottky barrier at the carbon nanotube-metal interface.
Low-loss left-handed metamaterials at millimeter waves
Authors: Zhang Fuli , Gaillot Davy P. , Croënne Charles , Lheurette Eric , Mélique Xavier , Lippens Didier
Published: August 2008

An omega-type multilayered metamaterial aimed at operating at millimeter wavelengths was characterized between 75 and 110 GHz (W-band). The fabrication involves a monolithic integration of planar arrays of broad-side coupled microresonators with a benzocyclobutene spacing layer printed onto quartz substrates. The frequency dependence of the transmittance shows a well-resolved transmission window centered around 80 GHz with a 10% fractional bandwidth and another one starting from 100 GHz, both displaying comparable high transmission levels. The left- or right-handed behavior is assessed by the comparison of the phase delay between two devices of different lengths and by tilted-incidence transmission experiments.
Recirculation in multiple wave conversions
Authors: Brizard A. J. , Kaufman A. N. , Tracy E. R.
Published: August 2008

A one-dimensional multiple wave-conversion model is constructed that allows energy recirculation in ray phase space. Using a modular eikonal approach, the connection coefficients for this model are calculated by ray phase-space methods. Analytical results (confirmed numerically) show that all connection coefficients exhibit interference effects that depend on an interference phase, calculated from the coupling constants and the area enclosed by the intersecting rays. This conceptual model, which focuses on the topology of intersecting rays in phase space, is used to investigate how mode conversion between primary and secondary waves is modified by the presence of a tertiary wave.
Solitary kinetic Alfvén waves in dusty plasmas
Authors: Li Yang-fang , Wu D. J. , Morfill G. E.
Published: August 2008

Solitary kinetic Alfvén waves in dusty plasmas are studied by considering the dust charge variation. The effect of the dust charge-to-mass ratio on the soliton solution is discussed. The Sagdeev potential is derived analytically with constant dust charge and then calculated numerically by taking the dust charge variation into account. We show that the dust charge-to-mass ratio plays an important role in the soliton properties. The soliton solutions are comprised of two branches. One branch is sub-Alfvénic and the soliton velocity is obviously smaller than the Alfvén speed. The other branch is super-Alfvénic and the soliton velocity is very close to or greater than the Alfvén speed. Both compressive and rarefactive solitons can exist. For the sub-Alfvénic branch, the rarefactive soliton is bell-shaped and it is much narrower than the compressive one. However, for the super-Alfvénic branch, the compressive soliton is bell-shaped and narrower, and the rarefactive one is broadened. When the charge-to-mass ratio of the dust grains is sufficiently high, the width of the rarefactive soliton, in the super-Alfvénic branch, will broaden extremely and a electron depletion will be observed. It is also shown that the bell-shaped soliton can transition to a cusped structure when the velocity is sufficiently high.
Efficient tandem organic solar cells with an Al/MoO3 intermediate layer
Authors: Zhao D. W. , Sun X. W. , Jiang C. Y. , Kyaw A. K. K. , Lo G. Q. , Kwong D. L.
Published: August 2008

We report efficient tandem organic solar cells with an Al and MoO3 intermediate layer. Such an intermediate layer with optimized thickness (1 nm Al and 15 nm MoO3) has high transparency (∼98% in the range from 350 to 900 nm) and efficient charge collections to realize electric connection in series. For polymer-small molecule tandem cell, due to the summation (1.01 V) of the open-circuit voltages of individual cells and a short-circuit current density of 6.05 mA/cm2, a power conversion efficiency (PCE) of 2.82% was obtained under 100 mW/cm2 illumination, which is larger than either of the individual cells. The PCE reached 3.88% when the tandem cell was illuminated under 300 mW/cm2. Additionally, we applied Al/MoO3 intermediate layer to realize a solution-processed polymer tandem cell with a high PCE (2.23%). The thick MoO3 (15 nm) provides a complete protection of the prior-deposited polymer layer from dissolving during the top cell polymer coating.
Effect of defects on oscillation characteristics and instability of carbon nanotube-based oscillators
Authors: Liu P. , Gao H. J. , Zhang Y. W.
Published: August 2008

The oscillatory characteristics and the instability of double- and triple-walled carbon nanotube-based oscillators containing a vacancy or a Stone–Wales (SW) defect were investigated by molecular dynamics simulations. It was found that the existence of these defects markedly affects the oscillation period and amplitude. The defect-free oscillators are most stable, followed by oscillators containing a SW defect, while oscillators containing a vacancy are least stable. The origin of the defect-induced instability is due to the change in potential energy profile and the resulting force fluctuation.
Electrical characterization of organic light-emitting diodes using dipotassium phthalate as n-type dopant
Authors: Ho Meng-Huan , Hsieh Ming-Ta , Chen Teng-Ming , Chen Jenn-Fang , Hwang Shiao-Wen , Chen Chin H.
Published: August 2008

An efficient n-doped electron transport layer composed of 4,7-diphenyl-1,10-phenanthroline (BPhen) and dipotassium phthalate (PAK2) has been developed. By temperature-dependent admittance spectroscopy, the incorporation of PAK2 into BPhen is found to raise the Fermi level from 1.7eV to only around 0.5eV below BPhen’s lowest unoccupied molecular orbital, which further enhances the efficiency of electron injection from an Al cathode. When this n-doped layer is adopted in an organic light-emitting diode device, the green fluorescent 10-(2-benzothiazolyl)-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H,11H-benzo[l]-pyrano[6,7,8-ij]quinolizin-11-one do-ped device can achieve a current efficiency of 16cd∕A and a power efficiency of 10.9lm∕W at 1000cd∕m2.
Temperature-dependent transition of discharge pattern of He/air cryoplasma
Authors: Choi Jai Hyuk , Noma Yuri , Tomai Takaaki , Terashima Kazuo
Published: August 2008

Dielectric barrier discharges were generated under atmospheric pressure at temperatures ranging from room temperature down to 88K. The gas temperature of the plasma generated by the discharges was controlled by liquid nitrogen, and a mixture of helium and air was used as the discharge gas. We found that microdischarges exhibited temperature-dependent specific discharge patterns as the temperature decreased. This transition of discharge patterns was closely related to the change in the gap voltage at breakdown. A possible scenario that may explain the pattern of the transition of the microdischarges is discussed.
Thermal SiO2 gated Ge metal-oxide-semiconductor capacitor on Si substrate formed by thin amorphous Ge oxidation and thermal annealing
Authors: Wu Yung-Hsien , Wu Jia-Rong , Lin Yuan-Sheng , Wu Min-Lin
Published: August 2008

The thermal SiO2 gated Ge metal-oxide-semiconductor (MOS) capacitor on Si substrate was accomplished by the direct oxidation of the amorphous Ge layer and a subsequent forming gas annealing. The epitaxial Ge on Si substrate shows the good crystallinity and the smooth interface with the thermal oxide. The oxide on the Ge layer is confirmed to have SiO2 bonding structure with tiny Ge content. The negligible hysteresis and the small frequency dispersion in C-V characteristics indicate the desirable oxide quality. The conduction mechanism through the oxide has been verified as Fowler–Nordheim tunneling with the conduction band offset of 2.81eV. Another intriguing point of this process lies in the fact that it provides a simpler and ultralarge scale integration-compatible approach to fabricate high-performance Ge MOS field effect transistors as compared with previous works.
High-density one-dimensional well-aligned germanium quantum dots on a nanoridge array
Authors: Chen Yan-Ru , Kuan Chieh-Hsiung , Suen Yuen-Wuu , Peng Yu-Hwa , Chen Peng-Shiu , Chao Cha-Hsin , Liang Eih-Zhe , Lin Ching-Fuh , Lo Hung-Chun
Published: August 2008

The selective growth of high-density one-dimensional well-aligned Ge quantum dots (QDs) on the top of nanoridges patterned on Si substrate is reported. The period of ridge array is 150 nm, the width of each ridge is 80 nm, and the depth of the trench is 20 nm. The areal density of QDs is about 5.4×109 cm−2. Simulations of the chemical potential show that a proper distribution of the surface curvature may give rise to a suitable chemical potential minimum helping positioning the QDs. These ridges can also be used to control the shape and the uniformity of QDs.
Genetic analysis of pod and seed resistance to pea weevil in a Pisum sativum×P. fulvum interspecific cross
Authors: Byrne O. M. , Hardie D. C. , Khan T. N. , Speijers J. , Yan G.
Published: August 2008

Interspecific populations derived from crossing cultivated field pea, Pisum sativum, with the wild pea relative, Pisum fulvum, were scored for pod and seed injury caused by the pea weevil, Bruchus pisorum. Pod resistance was quantitatively inherited in the F2 population, with evidence of transgressive segregation. Heritability of pod resistance between F2 and F3 generations was very low, suggesting that this trait would be difficult to transfer in a breeding program. Seed resistance was determined for the F2 population by testing F3 seed tissues of individual F2 plants and pooling data from seed reaction for each F2 plant (inferred F2 genotype). Segregation for seed resistance in the F2 population of the cross Pennant/ATC113 showed a trigenic mode of inheritance, with additive effects and dominant epistasis towards susceptibility. Seed resistance was conserved over consecutive generations (F2 to F5) and successfully transferred to a new population by backcross introgression. Seed resistance in the backcross introgressed population segregated in a 63 : 1 ratio, supporting the three-gene inheritance model. It is proposed that complete resistance to pea weevil is controlled by three major recessive alleles assigned pwr1, pwr2, and pwr3, and complete susceptibility by three major dominant alleles assigned PWR1, PWR2, and PWR3. It is recommended that large populations (>300 F2 plants) would be required to effectively transfer these recessive alleles to current field pea cultivars through hybridisation and repeated backcrossing.
Management of ash/impurity ratio in sugarcane: relative effects of genotypes, and N and K fertiliser rates
Authors: Jackson Phillip A. , Schroeder Bernard L. , Rattey Allan R. , Wood Andrew , O'Shea Michael G.
Published: August 2008

In sugarcane juice or raw sugar, ash refers to soluble inorganic salts. The ratio of ash/impurity is important because high levels reduce sucrose extraction in sugar mills and the market value of raw sugar. The aim of research reported here was to examine, through a series of field experiments, the effects of genotypes and varying N and K fertiliser application rates on ash and ash/impurity levels. Ash levels were estimated via conductivity measurements, following prior studies indicating close relationships between conductivity and ash.
Significant variation due to genotypes for conductivity/impurity levels was observed, with a range of about ±25% around the mean. Despite this variation, broad-sense heritability of conductivity/impurity levels on unselected genotypes on the basis of measurements in one environment were low (0.20), suggesting that selection in early phases of selection systems in breeding programs would probably be of limited value. However, it was recommended that measurements on conductivity/impurity ratio be made in multi-environment trials for genotypes being tested for commercial release, to assist in comprehensive economic evaluation.
On average it was found that conductivity/impurity levels increased by 15% per 100 kg/ha of applied K, highlighting potential costs of high rates of K fertiliser. Increased N rates had a significant but small effect on reducing conductivity/impurity levels by ~10% per additional 100 kg/ha of applied N.
The information reported here may be used to help develop optimal strategies for cultivar selection in sugarcane breeding programs and for developing recommendations for optimal fertiliser management, and some guidelines in relation to this are discussed.
Inheritance of coleoptile tiller appearance and size in wheat
Authors: Rebetzke G. J. , López-Castañeda C. , Acuña T. L. Botwright , Condon A. G. , Richards R. A.
Published: August 2008

Selection for rapid leaf area growth has the potential to increase wheat biomass, and both water-use efficiency and weed competitiveness early in the season. Several morphological components contribute to increased seedling leaf area, including rapid seedling emergence and production of longer, wider leaves. Early emergence of a large coleoptile tiller has also been demonstrated to increase plant leaf area and biomass in wheat and other grass seedlings. Yet little is known of the extent and nature of genotypic variation for coleoptile tiller growth in wheat. A random set of 35 wheat, barley, and triticale genotypes was evaluated in glasshouse and outdoor studies for seedling characteristics, including coleoptile tiller growth and total plant leaf area. Coleoptile tillers were produced more reliably for seedlings grown outdoors and when supplied with additional soil nitrogen. Genotypic differences in coleoptile tiller frequency and leaf area were large, ranging from 0 to 78% and from 0.0 to 1.4 cm2, respectively at very early growth stages. Australian commercial wheats tended to produce fewer coleoptile tillers of smaller size than overseas germplasm where the coleoptile tiller accounted for up to 12% of total seedling leaf area. This compared favourably with mainstem tiller leaf area, which ranged from 0 to 3.5 cm2 and accounted for up to 16% of plant leaf area. Broad-sense heritabilities were high for coleoptile tiller presence and size in favourable conditions (c. 75%) but low (c. 40%) for seedlings evaluated across nitrogen content-varying soils. Generation means analysis was used to investigate genetic control for coleoptile tiller growth across multiple populations. Significant (P < 0.05) differences were observed among generations for coleoptile tiller frequency and growth (numbers of leaves, leaf area, and biomass). These differences reflected strong additive genetic control with little evidence for any gene action × year interaction. Increases in coleoptile tiller frequency and mass were correlated with larger embryo size and wider seedling leaves to increase seedling leaf area (rg = 0.89). Comparisons between reciprocal F1 and F2 generation means indicated strong maternal effects for coleoptile tiller growth in some but not all crosses. Screening in favourable environments will increase heritability and aid in selection for progenies producing large coleoptile tillers. Evidence for additive genetic control should permit early generation selection but not without some progeny-testing for coleoptile tiller growth together with other early vigour components associated with increased plant leaf area.
Identification of variability in phenological responses in canola-quality Brassica juncea for utilisation in Australian breeding programs
Authors: Burton W. A. , Flood R. F. , Norton R. M. , Field B. , Potts D. A. , Robertson M. J. , Salisbury P. A.
Published: August 2008

Canola-quality Brassica juncea is a potential alternative crop species in lower rainfall Australian environments due to its superior heat and drought tolerance, disease resistance, and pod-shatter resistance compared with the currently grown B. napus species. Canola-quality types of B. juncea that are adapted to flower and mature before water deficits and high temperatures significantly limit yield potential are currently being developed. In this study, the variability in phenological characteristics in canola-quality B. juncea is assessed, with a view to identifying the potential for including a range of genetic phenological controls on the development of the crop to assist with adaptation.
Vernalisation response was compared among 17 lines of B. juncea and 3 of B. napus, using a cold treatment of 2.6°C for 25 days. Leaf number, and duration to first flower and maturity were compared in response to the vernalisation treatments. To assess day length response, the same 20 genotypes were sown at five locations with a range of sowing times, and one controlled environment, where day length was artificially extended. Development stages were assessed and the duration of particular phenological phases determined in relation to time, thermal time, and photoperiod.
The major factor controlling flowering in canola-quality B. juncea genotypes was day length, with only small responses to vernalisation detected. There was sufficient variability in these traits and in thermal time to flowering under long days (intrinsic earliness) within the current canola-quality germplasm in Australia to select early flowering genotypes with potential adaptation to low-rainfall environments.
Effects of partial rootzone drying and rootstock vigour on growth and fruit quality of 'Pink Lady' apple trees in Mediterranean environments
Authors: Talluto G. , Farina V. , Volpe G. , Lo Bianco R.
Published: August 2008

We investigated the effects of partial rootzone drying (PRD) and rootstock vigour on water relations, and vegetative and productive performance of ‘Pink Lady’ apple (Malus domestica Borkh.) trees in central Sicily. In a first field trial, trees on MM.106 rootstock were subjected to: Conventional irrigation (CI), maintaining soil moisture above 80% of field capacity; PRD irrigation, where only one alternated side of the rootzone received 50% of the CI irrigation water; and continuous deficit irrigation (DI), where 50% of the CI water was equally applied to both sides of the rootzone. In a second trial, trees on M.9 or MM.106 were subjected to CI and PRD irrigation. PRD reduced stomatal conductance (gs) more consistently in trees on MM.106 than in trees on M.9, but maintained relative water content (RWC) to the levels of CI. DI induced greater gs reductions than PRD and lower RWC than CI and PRD. Rootstock vigour did not influence plant response to irrigation strategy. PRD induced some reduction in fruit number but no change in yields and fruit quality compared with CI, whereas DI reduced fruit size and marketable yields. Significant reductions in shoot and leaf growth were induced by DI, whereas only leaf growth was affected by PRD. Our observations indicate that responses induced by PRD are due to a combination of the amount and way of applying water, and not just to reductions in irrigation volumes, suggesting a possible use of PRD for increasing apple water-use efficiency in Mediterranean environments.
Finding Wheat streak mosaic virus in south-west Australia
Authors: Coutts B. A. , Hammond N. E. B. , Kehoe M. A. , Jones R. A. C.
Published: August 2008

Between 2003 and summer 2006, 33 659 samples of wheat and grasses were collected from diverse locations in south-west Australia and tested for presence of Wheat streak mosaic virus (WSMV), but none was detected. In April–early May 2006, 2840 random samples of volunteer wheat from 28 fields on 24 farms in 6 districts in the grainbelt were tested. WSMV was detected for the first time, the infected samples coming from three fields, one in the Hyden and two in the Esperance districts. In ‘follow-up’ surveys in May 2006 in the same two districts, 8983 samples of volunteer wheat or grasses were tested, and the virus was detected on further farms, two in the Hyden and four in the Esperance districts. Incidences of infection in volunteer wheat were 1–8%, but WSMV was not found in grasses. By September 2006, when 1769 samples from further visits were tested, WSMV was detected in wheat crops or volunteer wheat plants at 2/3 of the original farms, with infection also found at one of them in barley, volunteer oats, and barley grass (Hordeum sp.). When samples of the seed stocks originally used in 2005 to plant five of the fields containing infected volunteer wheat at the three original infected farms were tested, seed transmission of WSMV was detected in four of them (0.1–0.2% transmission rates). In August–October 2006, 16 436 samples were collected in a growing-season survey for WSMV in wheat trials and crops throughout the grainbelt. WSMV was detected in 33% of ‘variety’ trials, 18% of other trials, 13% of seed ‘increase’ crops, and 52% of commercial crops. Incidences of infection were <1–100% within individual crops, <1–17% in trials, and <1–3% in seed increase crops. WSMV-infected sites were concentrated in the low-rainfall zone (east) of the central grainbelt. This area received considerable summer rains in 2006, which allowed growth of a substantial ‘green ramp’ of volunteer cereals and grasses, favouring infection of subsequent wheat plantings. WSMV was also detected at low levels over a much wider area involving all rainfall zones, from Dongara in the north to Esperance in the south. All 26 122 samples collected in January–May 2006 and 515 with possible WSMV symptoms collected in August–October 2006 were also tested for High plains virus (HPV), but it was not detected.
Increasing cloning possibilities using artificial zinc finger nucleases
Authors: Zeevi Vardit , Tovkach Andriy , Tzfira Tzvi
Published: August 2008

The ability to accurately digest and ligate DNA molecules of different origins is fundamental to modern recombinant DNA research. Only a handful of enzymes are capable of recognizing and cleaving novel and long DNA sequences, however. The slow evolution and engineering of new restriction enzymes calls for alternative strategies to design novel and unique restriction enzymes capable of binding and digesting specific long DNA sequences. Here we report on the use of zinc finger nucleases (ZFNs)—hybrid synthetic restriction enzymes that can be specifically designed to bind and cleave long DNA sequences—for the purpose of DNA recombination. We show that novel ZFNs can be designed for the digestion of specific sequences and can be expressed and used for cloning purposes. We also demonstrate the power of ZFNs in DNA cloning by custom-cloning a target DNA sequence and assembling dual-expression cassettes on a single target plasmid, a task that rarely can be achieved using type-II restriction enzymes. We demonstrate the flexibility of ZFN design and the ability to shuffle monomers of different ZFNs for the digestion of compatible recognition sites through ligation of compatible ends and their cleavage by heterodimer ZFNs. Of no less importance, we show that ZFNs can be designed to recognize and cleave existing DNA sequences for the custom-cloning of native target DNA molecules.
Magnetic alignment in grazing and resting cattle and deer
Authors: Begall Sabine , Červený Jaroslav , Neef Julia , Vojtěch Oldřich , Burda Hynek
Published: August 2008

We demonstrate by means of simple, noninvasive methods (analysis of satellite images, field observations, and measuring “deer beds” in snow) that domestic cattle (
n
= 8,510 in 308 pastures) across the globe, and grazing and resting red and roe deer (
n
= 2,974 at 241 localities), align their body axes in roughly a north–south direction. Direct observations of roe deer revealed that animals orient their heads northward when grazing or resting. Amazingly, this ubiquitous phenomenon does not seem to have been noticed by herdsmen, ranchers, or hunters. Because wind and light conditions could be excluded as a common denominator determining the body axis orientation, magnetic alignment is the most parsimonious explanation. To test the hypothesis that cattle orient their body axes along the field lines of the Earth's magnetic field, we analyzed the body orientation of cattle from localities with high magnetic declination. Here, magnetic north was a better predictor than geographic north. This study reveals the magnetic alignment in large mammals based on statistically sufficient sample sizes. Our findings open horizons for the study of magnetoreception in general and are of potential significance for applied ethology (husbandry, animal welfare). They challenge neuroscientists and biophysics to explain the proximate mechanisms.
Psychologically induced cooling of a specific body part caused by the illusory ownership of an artificial counterpart
Authors: Moseley G. Lorimer , Olthof Nick , Venema Annemeike , Don Sanneke , Wijers Marijke , Gallace Alberto , Spence Charles
Published: August 2008

The sense of body ownership represents a fundamental aspect of our self-awareness, but is disrupted in many neurological, psychiatric, and psychological conditions that are also characterized by disruption of skin temperature regulation, sometimes in a single limb. We hypothesized that skin temperature in a specific limb could be disrupted by psychologically disrupting the sense of ownership of that limb. In six separate experiments, and by using an established protocol to induce the rubber hand illusion, we demonstrate that skin temperature of the real hand decreases when we take ownership of an artificial counterpart. The decrease in skin temperature is limb-specific: it does not occur in the unstimulated hand, nor in the ipsilateral foot. The effect is not evoked by tactile or visual input
per se
, nor by simultaneous tactile and visual input
per se
, nor by a shift in attention toward the experimental side or limb. In fact, taking ownership of an artificial hand slows tactile processing of information from the real hand, which is also observed in patients who demonstrate body disownership after stroke. These findings of psychologically induced limb-specific disruption of temperature regulation provide the first evidence that: taking ownership of an artificial body part has consequences for the real body part; that the awareness of our physical self and the physiological regulation of self are closely linked in a top-down manner; and that cognitive processes that disrupt the sense of body ownership may in turn disrupt temperature regulation in numerous states characterized by both.
Flying in silence: Echolocating bats cease vocalizing to avoid sonar jamming
Authors: Chiu Chen , Xian Wei , Moss Cynthia F.
Published: August 2008

Although it has been recognized that echolocating bats may experience jamming from the signals of conspecifics, research on this problem has focused exclusively on time-frequency adjustments in the emitted signals to minimize interference. Here, we report a surprising new strategy used by bats to avoid interference, namely silence. In a quantitative study of flight and vocal behavior of the big brown bat (
Eptesicus fuscus
), we discovered that the bat spends considerable time in silence when flying with conspecifics. Silent behavior, defined here as at least one bat in a pair ceasing vocalization for more than 0.2 s (200 ms), occurred as much as 76% of the time (mean of 40% across 7 pairs) when their separation was shorter than 1 m, but only 0.08% when a single bat flew alone. Spatial separation, heading direction, and similarity in call design of paired bats were related to the prevalence of this silent behavior. Our data suggest that the bat uses silence as a strategy to avoid interference from sonar vocalizations of its neighbor, while listening to conspecific-generated acoustic signals to guide orientation. Based on previous neurophysiological studies of the bat's auditory midbrain, we hypothesize that environmental sounds (including vocalizations produced by other bats) and active echolocation evoke neural activity in different populations of neurons. Our findings offer compelling evidence that the echolocating bat switches between active and passive sensing to cope with a complex acoustic environment, and these results hold broad implications for research on navigation and communication throughout the animal kingdom.
Lignin degradation in wood-feeding insects
Authors: Geib Scott M. , Filley Timothy R. , Hatcher Patrick G. , Hoover Kelli , Carlson John E. , Jimenez-Gasco Maria del Mar , Nakagawa-Izumi Akiko , Sleighter Rachel L. , Tien Ming
Published: August 2008

The aromatic polymer lignin protects plants from most forms of microbial attack. Despite the fact that a significant fraction of all lignocellulose degraded passes through arthropod guts, the fate of lignin in these systems is not known. Using tetramethylammonium hydroxide thermochemolysis, we show lignin degradation by two insect species, the Asian longhorned beetle (
Anoplophora glabripennis
) and the Pacific dampwood termite (
Zootermopsis angusticollis
). In both the beetle and termite, significant levels of propyl side-chain oxidation (depolymerization) and demethylation of ring methoxyl groups is detected; for the termite, ring hydroxylation is also observed. In addition, culture-independent fungal gut community analysis of
A. glabripennis
identified a single species of fungus in the
Fusarium solani
/
Nectria haematococca
species complex. This is a soft-rot fungus that may be contributing to wood degradation. These results transform our understanding of lignin degradation by wood-feeding insects.
Recent climate extremes alter alpine lake ecosystems
Authors: Parker Brian R. , Vinebrooke Rolf D. , Schindler David W.
Published: August 2008

Here, we show that alpine lake ecosystems are responsive to interannual variation in climate, based on long-term limnological and meteorological data from the Canadian Rockies. In the 2000s, in years with colder winter temperatures, higher winter snowfall, later snowmelt, shorter ice-free seasons, and dryer summers, relative to the 1990s, alpine lakes became clearer, warmer, and mixed to deeper depths. Further, lakes became more dilute and nutrient-poor, the latter leading to significant declines in total phytoplankton biomass. However, increased concentrations of dissolved organic carbon in lake water stimulated the appearance of small mixotrophic algal species, partially offsetting the decline in autotrophic phytoplankton biomass and increasing algal species richness. The climate regime in the 2000s altered the physical, chemical, and biological character and the function of high-elevation aquatic ecosystems. Forecasts of increased climatic variability in the future pose serious ramifications for both the biodiversity and ecosystem function of high-elevation lakes.
Detection of pregnancies with high risk of fetal macrosomia among women with gestational diabetes mellitus
Authors: SUHONEN LAURI , HIILESMAA VILHO , KAAJA RISTO , TERAMO KARI
Published: August 2008

Objective. To compare the frequency of fetal macrosomia and Erb's palsy in two groups of women with gestational diabetes mellitus (GDM) and in healthy controls. Design. Retrospective clinical study of women with GDM. Setting. Pregnant women in Greater Helsinki area. Population. Nine hundred and five pregnancies and newborn infants of women with GDM and 805 non‐diabetic controls. Methods. GDM was diagnosed by a 2‐hour oral glucose tolerance test (OGTT) among women with risk factors for GDM. The treatment of GDM was resolved by a 24‐hour glucose profile obtained after 2 or 3 abnormal glucose values in the OGTT. Patients with a history of insulin‐treated GDM in a previous pregnancy and those with a fasting glucose over 6 mmol/l underwent a 24‐h glucose profile directly without a preceding OGTT. Main outcome measures. Fetal macrosomia, defined as a birth weight (adjusted for sex and gestational age) of >2.0 SD above the mean of a Finnish standard population. Erb's palsy. Results. 385 women (42.5%) were treated with insulin and diet and 520 (57.5%) with diet only. Macrosomia occurred more often in the insulin‐treated group (18.2%, p<0.001) compared with the diet‐treated group (4.4%) and the controls (2.2%). The rate of Erb's palsy was 2.7% in the insulin‐treated group, 2.4% in the diet‐treated group, compared with 0.3% in the controls (p <0.001). Conclusion. The 24‐hour glucose profile performed after the diagnosis of GDM clearly distinguishes between low‐risk (diet‐treated) and high‐risk (insulin‐treated) for fetal macrosomia in GDM pregnancies.
Dual-frequency ultrasound technique minimizes errors induced by soft tissue in ultrasound bone densitometry
Authors: Karjalainen J. , Töyräs J. , Rikkonen T. , Jurvelin J.S. , Riekkinen O.
Published: August 2008

Background: Most bone ultrasound devices are designed for through-transmission measurements of the calcaneus. In principle, ultrasound backscattering measurements are possible at more typical fracture sites of the central skeleton. Unfortunately, soft tissue overlying the bones diminishes reliability of these measurements.

Purpose: To apply the single-transducer dual-frequency ultrasound (DFUS) technique to eliminate the errors induced by soft tissue on the measurements of integrated reflection coefficient (IRC) in human distal femur in vivo.

Material and Methods: Ultrasound and dual-energy X-ray absorptiometry (DXA) examinations were conducted on a bodybuilder during a 21-week training and dieting period.

Results: Significant changes in quantity and composition of soft tissue took place during the diet. However, DXA measurements showed no significant effects on bone density measurements. The single transducer DFUS technique enabled the determination of local soft-tissue composition, as verified by comparison with the DXA ( r=0.91, n=8, p<0.01). Further, the technique eliminated the soft-tissue-induced error from IRC measured for the bone. The uncorrected IRC associated significantly with the change in local soft-tissue composition ( r=−0.83, n=8, p<0.05), whereas the corrected IRC values showed no significant dependence ( r=−0.30, n=8, p=0.46) on local soft-tissue composition.

Conclusion: The DFUS technique may significantly enhance the accuracy of clinical ultrasound measurements of bone.
Impact of Health Communication Campaigns on Health Behaviors in Singapore
Authors: Karan Kavita
Published: August 2008

The government of Singapore established the Health Promotion Board (HPB) in 2001 with an annual budget close to S$100 million to drive its health promotion and disease prevention programs. This article reviews the social marketing efforts of the HPB, in particular those campaigns related to healthy lifestyle during 2003–2006. A computer-assisted telephone interview survey conducted on over 300 Singaporeans reveals the impact of these campaigns on patterns of health awareness, health consciousness, risk perception, knowledge, and motivation that lead to adoption or nonadoption of prescribed disease prevention and health improvement practices. The survey found that while awareness of HPB campaigns is at a medium range among the respondents, a majority of those exposed to the campaigns have been influenced to adapt behaviors that lead to a healthy lifestyle.
Introduction
Authors: Armand Françoise
Published: August 2008

The first social marketing conference to focus exclusively on the developing world took place on line March 10–17, 2008. “Social Marketing for Health in the Developing World: What Have We Accomplished and What Does the Future Hold?” was “virtually attended” by nearly 1,000 individuals from social marketing organizations, nongovernmental organizations, government agencies, private foundations, academic institutions, and the commercial sector in over 70 countries.
The Saathiya Trusted Partner Program in India: Meeting Young Couples' Reproductive Health Needs
Authors: 'Sullivan Gael
Published: August 2008

Saathiya, or “trusted partner” in Hindi, is an apt name for a new private sector social marketing initiative designed to help young married couples in Lucknow, Uttar Pradesh make informed choices about how many children to have and when to start their families. Supported by funding from the U.S. Agency for International Development (USAID), contributions from eight different pharmaceutical and medical association partners, and technical guidance from Abt Associates through the Private Sector Partnerships-One Project (PSP-One), Saathiya was launched in October 2007 at a press conference led by local government and civic officials, USAID, and the medical community. Program innovations include an intervention/control research design to track changes in family planning-related knowledge, attitudes, and behavior, expansion of the service delivery network to include traditional medical doctors, a “basket” of four different short-acting contraceptives that are cobranded with the Saathiya program, and a youth-friendly promotional strategy that employs a helpline, short message service (SMS) text messaging, and the Internet in additional to traditional channels.