bluuebunny/crossref_metadata_2025 huggingface dataset:
Decadal variability of the tropical stratosphere: Secondary influence of the El Niño–Southern Oscillation
Authors: Hood L. L. , Soukharev B. E. , McCormack J. P.
Published: June 2010

A decadal variation of tropical lower stratospheric ozone and temperature has previously been identified that correlates positively with the 11 year solar activity cycle. However, the El Niño–Southern Oscillation (ENSO) also influences lower stratospheric ozone and temperature. It is therefore legitimate to ask whether quasi‐decadal ENSO variability can contribute to this apparent solar cycle variation, either accidentally because of the short measurement record or physically because solar variability affects ENSO. Here we present multiple regression analyses of available data records to compare differences in results obtained with and without including an ENSO term in the statistical model. In addition, simulations are performed using the NRL NOGAPS‐ALPHA GCM for warm/cold ENSO conditions to test for consistency with the ENSO regression results. We find only very minor changes in annual mean solar regression coefficients when an ENSO term is included. However, the observed tropical ENSO response provides useful insights into the origin of the unexpected vertical structure of the tropical solar cycle ozone response. In particular, the ENSO ozone response is negative in the lower stratosphere due to increased upwelling but changes sign, becoming positive in the middle stratosphere (5–10 hPa) due mainly to advective decreases of temperature and NOx, which photochemically increase ozone. A similar mechanism may explain the observed lower stratospheric solar cycle ozone and temperature response and the absence of a significant response in the tropical middle stratosphere.
Effects of interbasin water transfer on regional climate: A case study of the Middle Route of the South‐to‐North Water Transfer Project in China
Authors: Chen Feng , Xie Zhenghui
Published: June 2010

In this study, a water transfer mechanism was implemented into the regional climate model, RegCM3, to represent water to be transferred by increasing the precipitation that reached the surface in intake areas. The effects of interbasin water transfer on local and regional climates were then studied based on numerical simulations conducted using the RegCM3 model. The Middle Route of the South‐to‐North Water Transfer Project (MRSNWTP) in China was chosen as a case study to investigate the climatic responses under three different water transfer schemes with three intensities. Four 10‐year simulations were conducted, a control run (MCTL) without water transfer, and three water transfer runs (MWT1, MWT2, and MWT3) related to the three schemes. In the three water transfer runs, spatial and temporal water transfer data were derived from the schemes under the assumption that the quantity of water to be transferred into a county in the intake area in a year for each scheme was distributed evenly into each time step. Increases in top‐layer soil moisture and latent heat flux were observed when compared to the control, and these increases were found to occur as a direct result of injecting water into the intake area. The increases in latent heat flux and evaporation were accompanied with decreases in sensible heat flux, mean air temperature, and increases in precipitation in the intake area. These differences were generally small and statistically insignificant, indicating that the water transfer plays a small role in influencing regional climate in our simulations. However, the climatic influence intensity of a water transfer scheme was found to be positively related to the quantity of water to be transferred, and to have strong seasonal variability, with larger effect being observed in spring and autumn than in summer and winter. We also conducted a water transfer run, MWT4, using the same configuration as MWT3 but under the assumption that the quantity of water was distributed evenly into each time step of the first half of the year. Comparison of the two runs shows a stronger seasonal variability in the climatic influence when the water was assigned into the first half of the year than when it was assigned into the entire year. Further analysis revealed that the water transfer could reduce both the seasonal and diurnal temperature ranges at the surface and that the decrease in temperature could diffuse over almost the entire Huabei Plain below 700 hPa, thereby weakening the wind velocity of the easterly breeze. It follows from the analyses of the vertical profiles of the water vapor content and the atmospheric moisture budgets that the water transfer can affect the local and regional climates by changing the local water vapor content and the regional water vapor transports, which in turn influences precipitation.
Superrotation of Venus' atmosphere analyzed with a full general circulation model
Authors: Lebonnois Sébastien , Hourdin Frédéric , Eymet Vincent , Crespin Audrey , Fournier Richard , Forget François
Published: June 2010

A general circulation model (GCM) has been developed for the Venus atmosphere, from the surface up to 100 km altitude, based on the GCM developed for Earth at our laboratory. Key features of this new GCM include topography, diurnal cycle, dependence of the specific heat on temperature, and a consistent radiative transfer module based on net exchange rate matrices. This allows a consistent computation of the temperature field, in contrast to previous GCMs of Venus atmosphere that used simplified temperature forcing. The circulation is analyzed after 350 Venus days (111 Earth years). Superrotation is obtained above roughly 40 km altitude. Below, the zonal wind remains very small compared to observed values, which is a major pending question. The meridional circulation consists of equator‐to‐pole cells, the dominant one being located within the cloud layers. The modeled temperature structure is globally consistent with observations, though discrepancies persist in the stability of the lowest layers and equator‐pole temperature contrast within the clouds (10 K in the model compared to the observed 40 K). In agreement with observational data, a convective layer is found between the base of the clouds (around 47 km) and the middle of the clouds (55–60 km altitude). The transport of angular momentum is analyzed, and comparison between the reference simulation and a simulation without diurnal cycle illustrates the role played by thermal tides in the equatorial region. Without diurnal cycle, the Gierasch‐Rossow‐Williams mechanism controls angular momentum transport. The diurnal tides add a significant downward transport of momentum in the equatorial region, causing low latitude momentum accumulation.
Surface Cu-depletion of Cu(In,Ga)Se2 thin films: Further experimental evidence for a defect-induced surface reconstruction
Authors: Mönig H. , Fischer Ch.-H. , Grimm A. , Johnson B. , Kaufmann C. A. , Caballero R. , Lauermann I. , Lux-Steiner M. Ch.
Published: June 2010

The surface Cu-depletion of chalcopyrite thin films and its influence on the interface properties of related solar cells have been subject of a controversial debate for many years. Although the nature of this Cu-depletion and its extension in depth are crucial for the device physics, there are only a few contradictory experimental results that address this topic. To clarify this issue, we performed depth-dependent compositional analysis by angle dependent soft x-ray emission spectroscopy (AXES) on Cu(In,Ga)Se2 thin films with different integral Cu-contents. By considering depth profiles from literature and by taking the accuracy of AXES into account, our numerical AXES simulations predict a pronounced angle dependence for our samples. However, our experimental data show only a minor angle dependence, which leads to the conclusion that the Cu-depleted surface layer must be restricted to a very thin surface layer, which is not accessible by AXES. This conclusion is consistent with the result from our previous investigation by hard x-ray photoelectron spectroscopy, where we found a Cu-depleted surface layer in the subnanometer regime. Consequently the present study gives further experimental evidence for the surface reconstruction model proposed by first-principles calculations. Supported by secondary neutral mass spectroscopy, we show that the minor angle dependence in our AXES data can be attributed to a Ga-gradient in the chalcopyrite material.
Dipolar vortex formation in electromagnetic ion-temperature-gradient driven waves in a dust-contaminated magnetoplasma
Authors: Qamar Anisa , Khan M. Yaqub , Mirza Arshad M. , Ahmad Zulfiqar
Published: June 2010

We investigated linear and nonlinear properties of electromagnetic ion-temperature-gradient driven mode for a dissipative, nonuniform dust-contaminated electron-ion plasma with sheared ion flows. In the linear limit, a new dispersion relation has been derived and several interesting limiting cases are also discussed. On the other hand, in the nonlinear case, by ignoring dissipative effects, the nonlinear set of equations admits a dipolar vortex type solution. The results of the present investigation should be helpful to understand some linear as well as nonlinear properties of magnetically confined dust-contaminated tokamak edge plasmas.
Generalized Replica Exchange Method
Authors: Kim Jaegil , Keyes Thomas , Straub John E.
Published: June 2010

We present a powerful replica exchange method, particularly suited to first-order phase transitions associated with the backbending in the statistical temperature, by merging an optimally designed generalized ensemble sampling with replica exchanges. The key ingredients of our method are parametrized effective sampling weights, smoothly joining ordered and disordered phases with a succession of unimodal energy distributions by transforming unstable or metastable energy states of canonical ensembles into stable ones. The inverse mapping between the sampling weight and the effective temperature provides a systematic way to design the effective sampling weights and determine a dynamic range of relevant parameters. Illustrative simulations on Potts spins with varying system size and simulation conditions demonstrate a comprehensive sampling for phase-coexistent states with a dramatic acceleration of tunneling transitions. A significant improvement over the power-law slowing down of mean tunneling times with increasing system size is obtained, and the underlying mechanism for accelerated tunneling is discussed.
Drop dynamics after impact on a solid wall: Theory and simulations
Authors: Eggers Jens , Fontelos Marco A. , Josserand Christophe , Zaleski Stéphane
Published: June 2010

We study the impact of a fluid drop onto a planar solid surface at high speed so that at impact, kinetic energy dominates over surface energy and inertia dominates over viscous effects. As the drop spreads, it deforms into a thin film, whose thickness is limited by the growth of a viscous boundary layer near the solid wall. Owing to surface tension, the edge of the film retracts relative to the flow in the film and fluid collects into a toroidal rim bounding the film. Using mass and momentum conservation, we construct a model for the radius of the deposit as a function of time. At each stage, we perform detailed comparisons between theory and numerical simulations of the Navier–Stokes equation.
Chiroptical nature of two-exciton states of light-harvesting complex: Doubly resonant three-wave-mixing spectroscopy
Authors: Lee Hochan , Cheon Sangheon , Cho Minhaeng
Published: June 2010

Photosynthetic light-harvesting complex is a coupled multichromophore system. Due to electronic couplings between neighboring chlorophylls in the complex, the one- and two-exciton states are delocalized and they can be written as linear combinations of singly and doubly excited configurations, respectively. Despite that the chiroptical properties of one-exciton states in such a multichromophore system have been investigated by using linear optical activity measurement techniques; those of two-exciton states have not been studied before due to a lack of appropriate measurement methods. Here, we present a theoretical description on chiroptical χ(2) spectroscopy and show that it can be used to investigate such properties of a photosynthetic light-harvesting system, which is the Fenna–Matthews–Olson complex, consisting of seven bacteriochlorophylls in its protein subunit. To simulate the doubly resonant sum- and difference-frequency-generation spectra of the complex, one- and two-exciton transition dipoles were calculated. Carrying out quantum chemistry calculations of electronically excited states of a model bacteriochlorophyll system and taking into account the dipole-induced dipole electronic transition processes between the ground state and two-exciton states, we could calculate the two-dimensional sum-frequency-generation spectra revealing dominant second-order chiroptical transition pathways and involved one- and two-exciton states. It is believed that the present computational scheme and the theoretically proposed doubly resonant two-dimensional three-wave-mixing spectroscopy would be of use to shed light on the chiroptical natures of two-exciton states of arbitrary coupled multichromophore systems.
Precise phase synchronization of a cryogenic microwave oscillator
Authors: Ivanov E. N. , Mouneyrac D. , Le Floch J.-M. , Tobar M. E. , Cros D.
Published: June 2010

We developed a novel technique for accurate phase synchronization of microwave oscillators based on sapphire dielectric resonators cooled to liquid nitrogen temperature. The achieved quality of phase synchronization (a few milliradians) enables the accurate measurements of extremely weak phase fluctuations expected from the next generation of ultralow phase noise microwave oscillators.
Ab initio floating occupation molecular orbital-complete active space configuration interaction: An efficient approximation to CASSCF
Authors: Slavíček Petr , Martínez Todd J.
Published: June 2010

We have implemented a complete active space configuration interaction method (CASCI) based on floating occupation molecular orbitals (FOMOs) at the ab initio level. The performance of this FOMO-CASCI method was investigated for potential applications in photochemistry and photodynamics. We found that FOMO-CASCI often represents a good approximation to the state-averaged complete active space self-consistent field (SA-CASSCF) method. FOMO-CASCI is therefore an attractive alternative for use in ab initio photodynamics. The method is more efficient and more stable than SA-CASSCF. We also discuss some problematic cases for the FOMO-CASCI approach. Possible extensions of the FOMO-CASCI approach are discussed briefly.
Analysis of the stress distribution in the nonuniformly bent GaN thin film grown on a sapphire substrate
Authors: Jang Yuseong , Kim Won Rae , Jang Dong-Hyun , Shim Jong-In , Shin Dong-Soo
Published: June 2010

We analyze the stress distribution in the nonuniformly bent GaN epilayers grown on a sapphire substrate. By using theoretical analysis combined with an analytical formula describing the realistic shape for the wafer bending of GaN epiwafers, we examine the effect of nonuniformity in the wafer bending on the stress-value variation over the entire wafer. We show that the stress on the GaN thin film can deviate by ∼1 MPa from the value obtained by the simple Stoney’s formula that is typically used for the uniformly bent wafer. We also show that the maximum value of the stress linearly increases with the bow difference along the horizontal and vertical directions.
Connectedness percolation in polydisperse rod systems: A modified Bethe lattice approach
Authors: Chatterjee Avik P.
Published: June 2010

A mean-field theory is presented for the percolation behavior of systems of rodlike particles characterized by length polydispersity. An analogy to the problem of site percolation on a modified Bethe lattice is employed to estimate the percolation threshold, percolation probability, and backbone fraction as functions of the rod volume fraction and polydispersity. Model calculations reveal that the percolation probability and backbone fraction depend sensitively upon the rod length distribution, while the percolation threshold is governed primarily by the weight-averaged rod length.
A-site occupancy in the lead-free (Bi1/2Na1/2TiO3)0.94–(BaTiO3)0.06 piezoceramic: Combining first-principles study and TEM
Authors: Kling Jens , Hayn Silke , Schmitt Ljubomira A. , Gröting Melanie , Kleebe Hans-Joachim , Albe Karsten
Published: June 2010

The crystal structure of the lead-free piezoelectric ceramic (Bi1/2Na1/2TiO3)0.94–(BaTiO3)0.06 was investigated by first-principles calculations and high-resolution transmission electron microscopy (HRTEM) imaging. Structures with different A-site occupation were relaxed by total energy calculations within density functional theory and then used for simulating the corresponding HRTEM images. Simulated and experimental HRTEM images were compared and the closest match selected for structure interpretation. By combining these techniques, we have identified the Bi(Ba)/Na distribution on the A-site to be homogeneous. We exclude the possibility that regions visible in HRTEM images within one grain can be attributed to different ordering but to a slight tilting of the structure with respect to the electron beam.
Structure and stability of N–H complexes in single-crystal ZnO
Authors: Jokela S. J. , McCluskey M. D.
Published: June 2010

Zinc oxide (ZnO) is semiconductor with a wide band gap of 3.4 eV. It continues to gain more attention not only for its versatile use in industry but also its potential for further application in electronics, optics, spintronics, and transparent circuits. Many of these applications require p-type ZnO. Nitrogen substituting for oxygen is a possible acceptor for such applications. In this paper, we report a study of nitrogen-hydrogen (N–H) complexes grown into single-crystal ZnO, using seeded chemical vapor transport in an ammonia ambient. An infrared (IR) absorption peak arising from N–H complexes was observed at 3150.6 cm−1 at liquid-helium temperatures. The assignment of this peak was confirmed by nitrogen and hydrogen isotope substitution. Polarized IR spectroscopy shows that the N–H dipole is oriented at an angle ∼114° to the c axis, in agreement with previous first-principles calculations. To probe the stability of the N–H complexes, samples were annealed in air, oxygen, and argon. Samples annealed in oxygen at 725 °C showed a significant increase in resistivity, due to outdiffusion of hydrogen and compensation by nitrogen acceptors.
Room temperature infrared photoresponse of self assembled Ge/Si (001) quantum dots grown by molecular beam epitaxy
Authors: Singha R. K. , Manna S. , Das S. , Dhar A. , Ray S. K.
Published: June 2010

We report on the observation of intraband near infrared (∼3.1 μm) and mid infrared (∼6.2 μm) photocurrent response at room temperature using Ge/Si self-assembled quantum dots grown by molecular beam epitaxy. Due to the bimodal size distribution and SiGe intermixing, distinguishable photoluminescence transitions are observed at 10 K, below and above the optical band gap of bulk Ge. The observed redshift in photocurrent with increasing temperature has been explained by the excitonic electric field originated due to infrared excitation at low temperatures. A good correlation between the spectral photocurrent response and photoluminescence of the quantum dots has been established.
Impedance spectroscopy of micron sized magnetic tunnel junctions with MgO tunnel barrier
Authors: Ingvarsson Snorri , Arikan Mustafa , Carter Matthew , Shen Weifeng , Xiao Gang
Published: June 2010

We have studied the magnetoimpedance of micron sized magnetic tunnel junction sensors with 1.7 nm MgO tunnel barrier. We performed ac impedance spectroscopy in the frequency range between 100 Hz–40 MHz as a function of applied magnetic field in the sensing direction. We model our devices with a simple RLC circuit. Fitting the model to our data results in frequency independent R, L, and C, and our low frequency results are in agreement with dc measurements. Despite excellent agreement with published result on interface capacitance for MgO barrier magnetic tunnel junctions similar to ours we do not observe any magnetocapacitance in our devices.
Range-separated local hybrids
Authors: Haunschild Robin , Scuseria Gustavo E.
Published: June 2010

We present two range-separated (screened and long-range-corrected) extensions to our recent work on local hybrids of generalized gradient approximation exchange. Our screened local hybrid improves over HSE06 for thermochemistry and barrier heights. The long-range-corrected (LC) local hybrid improves over LC-ωPBE for heats of formation and nonhydrogen transfer reaction barriers but does not reach the accuracy of LC-ωPBE for hydrogen transfer barrier heights.
Semipolar GaN films on patterned r-plane sapphire obtained by wet chemical etching
Authors: de Mierry P. , Kriouche N. , Nemoz M. , Chenot S. , Nataf G.
Published: June 2010

It is shown that (112¯2)-oriented GaN films can be achieved from r-sapphire patterned by chemical etching. Growth first occurs selectively from the inclined c-facet of sapphire, leading finally to a fully coalesced layer with (112¯2) orientation. The structural and optical quality of these layers was assessed by x-ray diffraction, cathodoluminescence and photoluminescence measurements. The results clearly show that the quality of (112¯2) GaN on patterned r-sapphire is markedly improved in comparison with (112¯2) GaN on m-sapphire.
Temporal and spatial regional cattle farm turn-off patterns in eastern Australia
Authors: Donald G. E. , Miron D. J. , Dyall T. , Garner M. G.
Published: June 2010

The introduction of the National Livestock Identification System served to provide a record of cattle movements by using an effective, electronic animal tracking system across Australia. The availability of an algorithm to simulate real-time and accurate movements of cattle is critical in the event of a major exotic disease outbreak. Such an algorithm could also be used for forecasting and formulation of policies to manage emerging disease threats. The National Livestock Identification System database will provide the basis for testing and verifying real-time and forecast cattle livestock turn-off patterns as a precursor to developing a real-time cattle movement simulation algorithm. The study demonstrated the major drivers and that real-time pasture information clearly needed to be incorporated into a movement model.
Measuring the shear force of lamb meat cooked from frozen samples: comparison of two laboratories
Authors: Hopkins D. L. , Toohey E. S. , Warner R. D. , Kerr M. J. , van de Ven R.
Published: June 2010

The tenderness of 160 samples of m. longissimus thoracis et lumborum (LL) from 40 sheep carcasses was measured at two laboratories, 80 samples per laboratory, with two ageing times (0 and 5 days). The samples were all cooked from frozen and then measured on the same type of machine, a Lloyd Texture analyser with a Warner–Bratzler-type shearing blade attached to give a shear force value for each sample. Shear force results were natural log-transformed and the analysis showed that there was a significant (P < 0.001) effect of ageing on shear force and a significant (P = 0.01) difference between the laboratories. Thus, on equivalent samples, Laboratory B produced shear force results 0.78 times those for Laboratory A. There was no significant (P > 0.05) effect of ageing on cooking loss, but there was a significant (P < 0.05) difference between the laboratories. On equivalent samples, Laboratory B produced lower cooking loss results (expressed as a percentage), on average by 3.1%, than did Laboratory A. When cooking loss was included in the model for shear force, it was significant (P < 0.001), and its inclusion reduced the significance (P = 0.04) of the difference between laboratories. Thus, part of the differences between the two laboratories for shear force could be explained by the difference in the cooking loss at the two laboratories. As cooking loss increased, shear force increased.
Influence of end-grazing forage residual and grazing management on lamb growth performance and crop yield from irrigated dual-purpose winter wheat
Authors: Miller D. R. , Dean G. J. , Ball P. D.
Published: June 2010

The effects of end-grazing forage residual and continuous v. rotational grazing systems on prime lamb performance, grain yield and quality were examined in an irrigated dual-purpose winter wheat (cv. Mackellar) crop in Tasmania. The design was a two end-grazing residual (400 and 800 kg/ha of dry matter (DM) at Zadoks Growth Stage 30, Low and High respectively, 0.2 ha plots) × two grazing system (continuously, or rotationally grazed in four subplots) factorial, replicated three times. Mixed-sex, second-cross lambs [37 kg liveweight (LW), 2.5 body condition score, 45 kg DM/head initial feed allowance] grazed for a total of 46 days before removal. Initial feed availability was 1875 kg DM/ha, with final residuals of 520 ± 57 and 940 ± 70 kg DM/ha for the Low and High treatments respectively. Particularly for the Low residual, in vitro DM digestibility and crude protein at stem elongation were reduced (P < 0.05) by rotational compared with continuous grazing. The weekly lamb growth rate (g/day) during the first 5 weeks of grazing was linearly related to average weekly available DM in kg/ha (GR = 0.35 ± 0.041 × DM – 194 ± 49.0, P < 0.01, R2 = 0.56). Total LW produced (336 ± 11.7 kg/ha), and grain yield (6.9 ± 0.21 t/ha), protein (11.4%), screenings <2.2 mm (10.9%) and 100 grain weights (3.82 g DM) were not different between treatments. There were no advantages of rotational grazing compared with continuous grazing. Irrigated dual-purpose winter wheat can be continuously grazed by lambs up to a 500 kg DM/ha residual at stem elongation without compromising total LW produced, grain yields or grain quality.
Effect of offering concentrate supplement in late pregnancy, under conditions of unrestricted herbage, on the performance of multiple-bearing ewes and their lambs to weaning
Authors: Kenyon P. R. , Wall A. J. , Burnham D. L. , Stafford K. J. , West D. M. , Morris S. T.
Published: June 2010

The aim of the present study was to determine if offering ewes a commercial concentrate supplement under conditions of unrestricted perennial ryegrass–white clover herbage availability would increase newborn lamb heat production, colostrum intake and subsequent liveweight. Forty seven twin- and 43 triplet-bearing Romney composite ewes (1/2 Romney, 1/4 Finn, 1/4 Texel) were randomly allocated to either non-concentrate or concentrate treatment groups (twin non-concentrate, n = 24; twin concentrate, n = 23; triplet non-concentrate, n = 22; triplet concentrate, n = 21) from Day 79 of pregnancy. Concentrate-fed ewes were offered an increasing amount of concentrate sheep pellets from Day 79 until Day 90 of pregnancy, at which stage ewes were offered 400 g/day per ewe until they lambed. Pre- and post-grazing herbage masses did not differ (P > 0.05) between non-concentrate (2162 ± 54 and 1704 ± 47 kg DM/ha) and concentrate (2135 ± 49 and 1771 ± 42 kg DM/ha) ewes. Ewe nutritional treatment had no effect (P > 0.05) on ewe liveweight, body condition score, β-hydroxybutyate or non-esterified fatty acid concentrations in late pregnancy. Offering concentrates increased (P < 0.05) the birthweight of triplet-born lambs (4.4 ± 0.1 v. 3.9 ± 0.1 kg for those born to concentrate and non-concentrate ewes, respectively) but had the opposite effect on twins (4.8 ± 0.1 v. 5.2 ± 0.1 kg, respectively). There was no difference (P > 0.05) in maximal heat production, total heat production, rate to reach maximal heat production, and IgG concentrations at 24–36 h of age or liveweight and survival of lambs born to ewes offered concentrates or not. Twin-born lambs had greater (P < 0.05) liveweight and total heat production and had higher (P < 0.05) survival rates than triplet-born lambs. In conclusion, the results of the present study indicate that there are only minor beneficial effects from offering concentrate supplements to ewes in late pregnancy under conditions of unrestricted herbage availability and it is not a viable option for farmers to utilise.
Can a herb and white clover mix improve the performance of multiple-bearing ewes and their lambs to weaning?
Authors: Kenyon P. R. , Kemp P. D. , Stafford K. J. , West D. M. , Morris S. T.
Published: June 2010

The productive performance of highly fecund ewes and their progeny on ryegrass-based swards is limited in late pregnancy and lactation. Alternative herbages, such as chicory, plantain and red and white clover, have the potential to improve performance levels. In the present study, 49 twin- and 42 triplet-bearing Romney composite ewes bred to either Suffolk or Romney rams were allocated to one of three nutritional treatments from Day 131 of pregnancy [19 twin ewes on a ryegrass–white clover sward mix (Rye/WC); 16 twin ewes on a plantain–ryegrass sward mix (Plant/Rye); 14 twin ewes on a chicory–plantain–red and white clover sward mix (Herb); 13 triplet ewes on Rye/WC; 16 triplet ewes on Plant/Rye; and 13 triplet ewes on Herb] and remained on these sward treatments with their lambs until 75 days after the midpoint of the lambing period (L75). Nutritional treatment had no effect (P > 0.05) on ewe liveweight, body condition score (BCS) or non-esterified fatty acid and β-hydroxybutyrate concentrations on Day 145 of pregnancy. At L75, ewes on the Herb treatment sward were heavier than ewes on Plant/Rye (70.75 ± 1.31 v. 61.43 ± 1.28 kg, respectively) and had a higher BCS than ewes on either Plant/Rye or Rye/WC (2.7 ± 0.1, 2.2 ± 0.1 and 2.3 ± 0.1, respectively). Sire type and nutritional treatment had no affect (P > 0.05) on lamb birthweight or weight at L75. At L20, lambs born to ewes on the Herb sward treatment were heavier than those on the Rye/WC and Plant/Rye treatments (8.74 ± 0.23 v. 7.98 ± 0.23 and 7.79 ± 0.22 kg, respectively; P < 0.05). Neither birth rank, sire type nor ewe treatment had any effect (P > 0.05) on maximum heat production on a per kg liveweight basis or total heat production. Romney-sired lambs on the Herb sward treatment had higher (P < 0.05) survival rates than those on the Rye/WC sward treatment (97.8% v. 61.7%, respectively). However, no such relationship was observed in lambs born to Suffolk sires (79.8% v. 84.8%, respectively). The survival response resulted in greater (P < 0.05) total liveweight of Romney-sired lambs at L75 per ewe on the Herb nutritional treatment than on the Rye/WC treatment (61.6 ± 5.0 v. 36.7 ± 4.6 kg, respectively) a relationship not observed (P > 0.05) in Suffolk-sired lambs. In conclusion, the present study indicates that there is the potential to improve the productive performance of multiple-bearing ewes and their lambs by grazing on a Herb sward mix.
Effect of the concentration of Spirulina (Spirulina platensis) algae in the drinking water on water intake by cattle and the proportion of algae bypassing the rumen
Authors: Panjaitan T. , Quigley S. P. , McLennan S. R. , Poppi D. P.
Published: June 2010

Spirulina, a freshwater microalgae, has previously been shown to increase the efficiency of microbial protein production in cattle fed hay with a low crude protein content. The present study was carried out to determine the effect of increasing the concentration of Spirulina in the drinking water on the intake of water and the amount of water containing Spirulina bypassing the rumen of cattle. Five rumen-cannulated steers were given a fixed amount of pangola grass hay (14 g DM/kg W.day–1) and water containing 0, 1, 2, 2.7 and 3.5% (w/w) Spirulina in an incomplete Latin square design. Water intake by the control steers (0% Spirulina) was 29.7 and 49.3 g/kg W for the first drinking event after it was made available and over 24 h, respectively. For steers receiving the algae, intake of water plus Spirulina increased linearly (P < 0.01) from 42.7 to 60.2 g/kg W during the first drinking event, as the concentration of Spirulina in the drinking water increased, but over 24 h was not affected by Spirulina concentration and averaged 74.4 g/kg W. The bypass of water through the rumen, as determined using chromium-EDTA as a marker, averaged 20.5 ± 1.2% and was not affected by the concentration of Spirulina in the drinking water. Increasing inclusion of Spirulina was associated with a decrease in rumen pH, an increase in urea concentration in blood serum, and an increase in ammonia-N concentration, propionate and branched-chain fatty acids, and a decrease in butyrate proportions in rumen fluid. Spirulina inclusion in the drinking water increased water intake and may provide a potential safe and inexpensive alternative to urea for extensively grazed ruminants.
Fat depth, muscle depth, fat score and wool growth in Merino dams selected for high or low clean fleece weight and bodyweight
Authors: Refshauge G. , Hatcher S. , Hinch G. N. , Hopkins D. L. , Nielsen S.
Published: June 2010

Concerns exist that selection for increased clean fleece weight (CFW) is expected to reduce body fatness. Such an effect is likely to impact on reproduction; however, all previous studies have examined non-reproductive yearlings or hoggets. The present study, using adult reproductive dams examined the impact of phenotype [based on high or low phenotypic CFW and bodyweight (BWT) performance], stocking rate (high or low) and litter size on body composition and wool traits. High CFW dams were heavier (P < 0.01) with lower fat depth (P < 0.01) and muscle depth (P < 0.05). The high CFW twin-weaning dams had a lower fat score from lamb marking to pre-joining (P < 0.05), but tended to replete fat reserves faster (P < 0.1) between weaning and pre-joining. At these times of repletion these animals grew longer wool staples (P < 0.05). High BWT ewes had reduced staple length (P < 0.01), and when adjusted for maternal liveweight also reduced fat depth (P < 0.001) and muscle depth (P < 0.05). We conclude that the CFW phenotype impacts on fat reserves but that management of dams in groups according to their CFW performance is not warranted.
Can rumen methane production be predicted from volatile fatty acid concentrations?
Authors: Robinson D. L. , Goopy J. , Hegarty R. S.
Published: June 2010

Rumen cannulated sheep (n = 12) were tested at each of three feeding levels: 0.8, 1.24 and 1.6 times maintenance. The ration (lucerne chaff) was provided in eight equal portions to emulate morning and afternoon grazing. After at least 10 days adaptation to each feeding level, methane production was measured in an open circuit calorimeter for 22 h using the same feeding regime. During measurement, 10 rumen samples were taken for volatile fatty acid (VFA) analysis by an indwelling rumen probe with a sampling tube that passed outside the calorimeter. Feed intake was strongly correlated with daily methane production (DMP, r = 0.87). Both methane production and VFA concentrations showed bimodal patterns related to the feeding cycle, but feed intake had a much smaller effect on VFA concentrations than on methane production rate. Average VFA concentration was a poor predictor of DMP. The best predictor, propionate concentration, explained 26% of the variance in DMP. The weakness of the association between VFA concentrations and methane production could be a consequence of differences in rumen volume and differences in VFA absorption associated with feeding level, although the possibility of accumulation of alternate fermentation end products or re-fermentation of VFA cannot be excluded. It is concluded that none of the suite of VFA parameters assessed offers a useful tool to predict daily methane production in grazing sheep.
Modes of transmission of rumen protozoa between mature sheep
Authors: Bird Simon H. , Hegarty R. S. , Woodgate R.
Published: June 2010

Three experiments were conducted to evaluate routes by which viable rumen ciliate-protozoa may be transferred between mature sheep. Feed, water and faecal material were tested as possible vectors for protozoal transfer in addition to direct animal to animal contact. In Experiment 1, protozoa-free sheep were either offered or orally dosed with protozoa-contaminated material or allowed contact with faunated animals. The treated sheep were then monitored over a 4-week period for the appearance of protozoa in the rumen. Protozoa were successfully transferred to protozoa-free animals via contaminated water but no transfer occurred via feed or faeces or by direct animal to animal contact. In Experiment 2, the drinking water of penned faunated sheep was found to become contaminated with protozoa within 4–6 h of being placed in the pen. In Experiment 3, nine protozoa-free sheep were grazed in a paddock with a flock of 75 faunated ewes for periods of 1–3 weeks, and protozoa became established in one protozoa-free sheep. The results of these studies suggest that the most likely mode of transfer of protozoal cells from one sheep to another is via water, rather than by rumen fluid contaminating feed, or from faeces of faunated sheep. Further tests are required to demonstrate protozoal transmission via water occur under a range of conditions and inoculum levels.
Cooperative Research Centres as effective institutions for contemporary models for achieving innovation in primary industry
Authors: Thomas P.
Published: June 2010

The creation of a formal organisational structure that brings together the specific needs of particular industries, with the expertise and research capacity available through recognised research providers, has an underlying and undeniable logic. Cooperative Research Centres (CRCs) provide this formal structure and are generally strongly focussed on carrying out applied outcome-driven research to improve productivity through innovation. Despite this strong commercial focus and record of scientific-output CRCs, there is general recognition that adoption of research from CRCs can be improved. The present paper focuses on primary industry CRCs and discusses the applicability of contemporary innovation concepts, which have evolved through the process of industrialisation and socialisation of science, and their application for improving innovation within primary industry CRCs. Specifically considered are 4th and 5th generation innovation concepts that promote ideas within ‘Open Innovation’ and ‘Knowledge Creation’ as a means of improving innovation within the primary industry CRCs organisational structure.
Aligning farm decision making and genetic information systems to improve animal production: methodology and findings from the Australian dairy industry
Authors: Nettle Ruth , Paine Mark , Penry John
Published: June 2010

To date there has been little research into the way genetic improvement decisions are made in practice on Australian farms. This type of knowledge is important for guiding the design of programs to increase the use of genetic information and thereby the rate of genetic gain in animal production systems. This paper describes an approach to understanding farm decision making in order to improve the design of services to increase the use of genetic information in the Australian dairy industry. A mixed-method approach involving a national survey and regional focus groups was used to determine farmers’ perceptions of the genetic information system overall and the key features of bull selection decisions and information sources. The current genetic information system was found to have a strong reputation for ease of access, use and fit with the way farmers evaluated bulls. In the focus groups the farmers described their decision process as having an ‘ideal cow’ in mind that fitted their farming system (e.g. balancing survival, milk volume, milk components, mammary features, fertility, milking speed, etc.). Bull proofs were then screened to identify a batch of eligible bulls that were further screened for their specific situation. Focus groups of advisers generally concurred with the process described by farmers. Further, farmers tended to rely on one or two main information sources in making decisions. To address the issue of greater alignment between farmer decision making and use of genetic information through industry organisations requires a coordinated strategy and a comprehensive development program. Suggestions for activities to this end are outlined.
Structural Changes in CuII Complexes of Potential Octadentate Ligands by Coordination with Carboxylate/Carboxylic Acid: DFT, TD-DFT, and Experimental Studies
Authors: Montiel Enrique , Cruz Julian , Jayanthi Narayanan , Bernés Sylvain , Pandiyan Thangarasu
Published: June 2010

The structural and spectroscopic studies of N,N,N′,N′,N′-pentakis-(benzimidazol-2-yl-methyl)diethylenetriamine (L1) and N,N,N′,N′-tetrakis-(benzimidazol-2-yl-methyl)-N′-(carboxylmethyl)diethylenetriamine (L2H) and [CuL1]2+, [CuL2H]2+, and [CuL2]+ were carried out by density functional theory (DFT) and time-dependant (TD)-DFT techniques. The results show that a geometrical change occurs when carboxylate/carboxylic acid coordinates with the metal ion. For example, the ligand L2H forms an octahedral geometry with CuII and in the structure, four nitrogens (N3, N13, N44, N47) are equatorially coordinated with the metal ion, and atoms O50 (–COOH) and N41, which are weakly bonded at the axial positions, are in competition in the formation of an axial bond with CuII; however, for the ligand L2, only a square pyramidal (SP) geometry results with CuII because of the formation of a strong axial bond by O50 (–COO–) with CuII, which dictates non-bonding at its trans position. Molecular orbital analysis proves that both HOMO and HOMO – 1 are localized over the carboxylate ion that favours a strong axial bond with the metal ion; thus, the SP geometry results in the X-ray structure of [CuL2]ClO4. Furthermore, for the complexes, since the electronic spectroscopic bands were unseparated in the spectra, the TD-DFT was used to identify the bands.
Dereplication of Bromotyrosine-derived Metabolites by LC-PDA-MS and Analysis of the Chemical Profile of 14 Aplysina Sponge Specimens from the Brazilian Coastline
Authors: Silva Michelli M. , Bergamasco Juliana , Lira Simone P. , Lopes Norberto P. , Hajdu Eduardo , Peixinho Solange , Berlinck Roberto G. S.
Published: June 2010

In order to investigate the chemical profile of 14 specimens of Aplysina spp. marine sponges, we have developed a method based on LC-PDA-MS for the detection of bromotyrosine-derived metabolites. The method enabled the dereplication of three distinct chemotypes of bromotyrosine-derived compounds based on UV absorptions, which were further refined by electrospray ionization-mass spectrometry analysis of the brominated quasi-molecular ion clusters. This procedure led to either a single compound assignment, or a maximum of two possible isobaric compounds. The dereplication study indicated that the chemical profile of the 14 specimens of Aplysina spp. analyzed presented practically the same dibromotyrosine-derived compounds. The results obtained suggested a possible biogenetic pathway for the formation of dibromotyrosine-derived compounds of wide occurrence in Verongida sponges.
9-(5'-Deoxy-5'-thio-β-D-xylofuranosyl)adenine Disulfide from the Southern Australian Marine Sponge Trachycladus laevispirulifer: the First Natural Occurrence of a Nucleoside Disulfide
Authors: Peng Chongsheng , Gunaherath G. M. Kamal B. , Piggott Andrew M. , Khalil Zeinab , Conte Melissa , Capon Robert J.
Published: June 2010

Chemical fractionation of a southern Australian marine sponge, Trachycladus laevispirulifer, yielded 9-(5′-deoxy-5′-thio-β-d-xylofuranosyl)adenine disulfide as the first recorded natural occurrence of a nucleoside disulfide, and only the second of a xylo-nucleoside. Structure elucidation of the disulfide was achieved by detailed spectroscopic analysis and comparison to synthetic model compounds. The antibacterial, antifungal, and anticancer properties of the disulfide are documented and the literature surrounding natural and synthetic thionucleosides is reviewed.
Stereochemical Elucidation of New Sagittamides C - F from a Didemnid Ascidian
Authors: Lievens Sarah C. , Morinaka Brandon I. , Molinski Tadeusz F.
Published: June 2010

Four new minor congeners, sagittamides C–F, were isolated from an unidentified Didemnid tunicate that previously afforded sagittamides A and B. The structures were determined by interpretation of spectroscopic data, degradation to amino acids, and comparisons with sagittamide A. An unexpected change in relative configuration of the hexacetoxy C5–C10 stereoelement is present in sagittamides D and F. A tentative assignment of configuration was possible through a systematic deduction based on analysis of 13C NMR data and symmetry considerations.
Saliniquinones A - F, New Members of the Highly Cytotoxic Anthraquinone-γ-Pyrones from the Marine Actinomycete Salinispora arenicola
Authors: Murphy Brian T. , Narender Tadigoppula , Kauffman Christopher A. , Woolery Matthew , Jensen Paul R. , Fenical William
Published: June 2010

Six new anthraquinone-γ-pyrones, saliniquinones A–F (1–6), which are related to metabolites of the pluramycin/altromycin class, were isolated from a fermentation broth of the marine actinomycete Salinispora arenicola (strain CNS-325). Their structures were determined by analysis of one- and two-dimensional NMR spectroscopic and high-resolution mass spectrometric data. The relative and absolute configurations of compounds 1–6 were determined by analysis of NOESY NMR spectroscopic data and by comparison of circular dichroism and optical rotation data with model compounds found in the literature. Saliniquinone A (1) exhibited potent inhibition of the human colon adenocarcinoma cell line (HCT-116) with an IC50 of 9.9 × 10–9 M. In the context of the biosynthetic diversity of S. arenicola, compounds 1–6 represent secondary metabolites that appear to be strain specific and thus occur outside of the core group of compounds commonly observed from this species.
Marine Pharmacology in Australia. The Roche Research Institute at Dee Why, New South Wales, 1974 - 81
Authors: Rae Ian D.
Published: June 2010

Hoffmann-La Roche supported the work of University of Queensland zoologist Robert Endean in the late 1960s, but the company’s deepening interest in the prospect of ‘drugs from the sea’ led them to establish the Roche Research Institute of Marine Pharmacology (RRIMP) at Dee Why, New South Wales. It was headed by Dr Joe Baker, an Australian organic chemist who had researched marine natural products. RRIMP took advice from several influential advisers, and Baker recruited chemists, pharmacologists, microbiologists, and marine biologists. Despite the conjecture, raised in some quarters, that RRIMP was established to mute the Australian government criticism of the pricing of Roche’s most famous product, Valium, I believe that the research venture was a genuine attempt to find lead compounds in organisms from Australian waters with a view to the development of new drugs. Changes in the research directions taken by Hoffmann-La Roche resulted in the closure of RRIMP in mid-1981, before any such success could be claimed for the Dee Why operation. RRIMP scientists, an elite but suddenly redundant group, secured positions in other Australian laboratories.