bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of index contrast in two dimensional photonic crystal lasers
Authors: Jørgensen Mette Marie , Petersen Sidsel Rübner , Christiansen Mads Brøkner , Buß Thomas , Smith Cameron L. C. , Kristensen Anders
Published: June 2010

The influence of index contrast variations for obtaining single-mode operation and low threshold in dye doped polymer two dimensional photonic crystal (PhC) lasers is investigated. We consider lasers made from Pyrromethene 597 doped Ormocore imprinted with a rectangular lattice PhC having a cavity in the middle of the crystal structure. We demonstrate that the index contrast, neff,high/neff,low, is an essential parameter for achieving low threshold, and we identify a trade-off between low threshold and single-mode operation.
Density functional theory plus U study of vacancy formations in bismuth ferrite
Authors: Zhang Zhen , Wu Ping , Chen Lang , Wang Junling
Published: June 2010

First-principles density functional theory plus U study on the formation enthalpy of BiFeO3 and the intrinsic vacancies was performed. The formation enthalpy of BiFeO3 from oxides is only −0.2 eV, indicating that BiFeO3 could easily decompose into Bi2O3 and Fe2O3 under thermal or electrical stresses. It is found that the vacancy induced local distortions have insignificant effect on the ferroelectric property, thanks to the high stability of the ferroelectric configuration in BiFeO3. Moreover, Bi and Fe vacancies have comparable formation energies, and become dominant in the oxygen rich conditions, leading to p-type conductivity.
Electron spin resonance probed suppressing of the cycloidal spin structure in doped bismuth ferrites
Authors: Lin J. W. , Tang Y. H. , Lue C. S. , Lin J. G.
Published: June 2010

The weak magnetism of bismuth ferrites Bi1−xDyxFeO3 with x=0.0 to 0.40 is studied via the electron spin resonance (ESR) of X-band (9.53 GHz) at various temperatures. The g-factor of pure BiFeO3 is 2.0, which originates from its cycloidal spin structure; while for the doped Bi1−xDyxFeO3 samples with x>0.10, ESR spectra reveal a second phase with a different g-factor around 1, which is attributed to the homogeneous magnetized phase of Bi1−xDyxFeO3. The temperature dependent ESR data further suggest a picture of the doping-induced transformation from cycloidal to canted antiferromagnetic state.
Band engineering of bilayer graphene by metal atoms: First-principles calculations
Authors: Oh D.-H. , Shin B. G. , Ahn J. R.
Published: June 2010

The continuous change in the electronic band structure of metal-adsorbed bilayer graphene was calculated as a function of metal coverage using first-principles calculations. Instead of modifying the unit cell size as a function of metal coverage, the distance between the metal atoms and bilayer graphene in the same 2×2 unit unit cell was controlled to change the total charges transferred from the metal atoms to bilayer graphene. The validity of the theoretical method was confirmed by reproducing the continuous change in the electronic band structure of K-adsorbed epitaxial bilayer graphene, as shown by Ohta et al. [Science 313, 951 (2006)]. In addition, the changes in the electronic band structures of undoped, n-type, and p-type bilayer graphene were studied schematically as a function of metal coverage using the theoretical method.
Surround-gated vertical nanowire quantum dots
Authors: van Weert M. H. M. , den Heijer M. , van Kouwen M. P. , Algra R. E. , Bakkers E. P. A. M. , Kouwenhoven L. P. , Zwiller V.
Published: June 2010

We report voltage dependent photoluminescence experiments on single indium arsenide phosphide (InAsP) quantum dots embedded in vertical surround-gated indium phosphide (InP) nanowires. We show that by tuning the gate voltage, we can access different quantum dot charge states. We study the anisotropic exchange splitting by polarization analysis, and identify the neutral and singly charged exciton. These results are important for spin addressability in a charge tunable nanowire quantum dot.
Absolute spectral gaps for infrared light and hypersound in three-dimensional metallodielectric phoxonic crystals
Authors: Papanikolaou N. , Psarobas I. E. , Stefanou N.
Published: June 2010

By means of full electrodynamic and elastodynamic multiple-scattering calculations we study the optical and acoustic properties of three-dimensional lattices of metallic nanospheres implanted in a dielectric host. Our results show that such structures exhibit omnidirectional spectral gaps for both telecom infrared light and hypersound, with relatively low absorptive losses. This class of dual (phoxonic) band-gap materials is an essential step toward the hypersonic modulation of light and could lead to the development of efficient acousto-optical devices.
Prediction of atmospheric pressure glow discharge in dielectric-barrier system
Authors: Duan Xiaoxi , He Feng , Ouyang Jiting
Published: June 2010

A one-dimensional fluid model was used to investigate the breakdown mechanism and discharge mode in dielectric-barrier system. The results show that the dielectric barrier discharge mode depends strongly on the gas property (i.e., the electron multiplication). The atmospheric pressure dielectric barrier glow discharge could only be achieved in a gas (e.g., noble gas) in which the first Townsend ionization coefficient is sufficiently small and the electron multiplication does not rise up rapidly with the electric field, while could not be sustained in the gas (e.g., N2 and O2) in which the electron multiplication is sensitive to the field.
Evolution of phase separation in In-rich InGaN alloys
Authors: Pantha B. N. , Li J. , Lin J. Y. , Jiang H. X.
Published: June 2010

Evolution of phase separation in InxGa1−xN alloys (x∼0.65) grown on AlN/sapphire templates by metal organic chemical vapor deposition has been probed. It was found that growth rate, GR, is a key parameter and must be high enough (>0.5 μm/h) in order to grow homogeneous and single phase InGaN alloys. Our results implied that conditions far from thermodynamic equilibrium are needed to suppress phase separation. Both structural and electrical properties were found to improve significantly with increasing GR. The improvement in material quality is attributed to the suppression of phase separation with higher GR. The maximum thickness of the single phase epilayer tmax (i.e., maximum thickness that can be grown without phase separation) was determined via in situ interference pattern monitoring and found to be a function of GR. As GR increases, tmax also increases. The maximum value of tmax for In0.65Ga0.35N alloy was found to be ∼1.1 μm at GR>1.8 μm/h.
Correlation between local structure distortions and martensitic transformation in Ni–Mn–In alloys
Authors: Lobo D. N. , Priolkar K. R. , Bhobe P. A. , Krishnamurthy D. , Emura S.
Published: June 2010

The local structural distortions arising as a consequence of increasing Mn content in Ni2Mn1+xIn1−x (x=0, 0.3, 0.4, 0.5, and 0.6) and its effect on martensitic transformation have been studied using extended x-ray absorption fine structure (EXAFS) spectroscopy. Using the room temperature EXAFS at the Ni and Mn K-edges in the above compositions, the changes associated with respect to the local structure of these absorbing atoms are compared. It is seen that in the alloys exhibiting martensitic transformation (x≥0.4) there is a significant difference between the Ni–In and Ni–Mn bond lengths even in the austenitic phase indicating atomic volume to be the main factor in inducing martensitic transformation in Ni–Mn–In Heusler alloys.
TiO
2
-coated carbon nanotubes: A redshift enhanced photocatalysis at visible light
Authors: Lu Sheng-Yi , Tang Chiung-Wen , Lin Yu-Hsien , Kuo Hsin-Fu , Lai Yao-Cheng , Tsai Meng-Yen , Ouyang Hao , Hsu Wen-Kuang
Published: June 2010

Annealing of carbon nanotubes coated with thin and uniform TiO2 results in carbon diffusion into oxygen lattices and doping induced redshift is evident by an efficient photocatalysis at visible light. The underlying mechanism is discussed.
Using MODIS imagery, climate and soil data to estimate pasture growth rates on farms in the south-west of Western Australia
Authors: Donald G. E. , Gherardi S. G. , Edirisinghe A. , Gittins S. P. , Henry D. A. , Mata G.
Published: June 2010

Remote sensing of vegetation and its monitoring using the normalised difference vegetation index (NDVI) offers the opportunity to provide a coverage of agricultural land at a large scale. The availability of MODIS NDVI at a resolution of 250 m provided the opportunity to evaluate the hypothesis that pasture growth rate (PGR) of individual paddocks can be accurately predicted using a model based on MODIS NDVI in combination with climate and soil data and a light-use efficiency model. Model estimates of PGR were compared with field measurements of PGR recorded in grazing enclosure cages collected over 3 years from six farms located across the south-west region of Western Australia. The estimates attained from the model explained 70% of the variation in PGR for individual paddocks on farms over the 3 years of the study, with an average error at the paddock scale of 10.4 kg DM/ha.day over all growing seasons and years. Across all farms studied, there was generally good agreement between satellite-derived PGR and ground-based measurements, although estimates of PGR varied between years and farms. The model explained 47% of the variation in pasture growth early in the season (from break of season to end of July), compared with 62% late in the season (from August to pasture senescence). The present study demonstrated that PGR for individual paddocks can be predicted at weekly intervals from MODIS imagery, climate and soil data and a light-use efficiency model at an accuracy sufficient to facilitate on-farm pasture and livestock management.
Wastage of conserved fodder when feeding livestock
Authors: Stockdale C. R.
Published: June 2010

The objective of the present review was to establish levels of conserved fodder wastage when feeding livestock (sheep, beef cattle, dairy cattle) under various conditions and using various feed-out systems, and to determine the factors affecting wastage. The mean wastage of hay recorded in the literature reviewed was 17% of the DM offered, but the range was from 4 to 77%. The main factors affecting the degree of wastage were storage method, packaging method, method of feeding out, amount of fodder on offer and its palatability and/or quality and the impact of wet weather. Although the emphasis was on hay, the principles should also apply to silage. If wastage was 40% rather than 5%, the cost of feeding conserved fodder to livestock would be a third greater than producers might expect or budget on.
Selection for fertility traits in Brahmans increases heifer pregnancy rates from yearling mating
Authors: Schatz T. J. , Jayawardhana G. A. , Golding R. , Hearnden M. N.
Published: June 2010

The performance of heifers from a Brahman herd that was selected for fertility was compared with Brahman heifers sourced from commercial properties using three year-groups of heifers. Each year, conception rates from yearling mating were significantly higher in heifers from the selected herd (SEL) than in heifers sourced from commercial properties (COM), despite the average joining weight of the SEL heifers being lower each year. The pregnancy rate in SEL heifers was 24% higher (P = 0.008) in the first year, 36% higher (P = 0.005) in the second year and 45% higher (P < 0.001) in the third year. Over the 3 years of the study, the conception rate was 35% higher (P = 0.009) in SEL heifers than in COM heifers. Joining weight also affected pregnancy rates. When heifers were split into weight ranges according to their pre-joining weight, pregnancy rates were significantly higher (P = 0.018) in the heavier weight range than the lighter one. The results indicate that selection for fertility has been successful in improving conception rates from yearling mating in SEL heifers.
Effects of Yerba Mate (Ilex paraguariensis) supplementation on the productive performance of dairy cows during mid-lactation
Authors: Celi Pietro , Raadsma Herman W.
Published: June 2010

Yerba Mate (Ilex paraguariensis), a tea known for its high antioxidant content, was fed (250 g/cow.day) to 8 of 16 Holstein cows for 6 weeks to assess its effect on their performance. Cows were weighed and blood samples were taken on Weeks 0, 3 and 6. Blood samples were centrifuged and plasma was analysed for reactive oxygen metabolites, biological antioxidant potential, advanced oxidation protein products and non-esterified fatty acids. Cows were milked two times daily and milk yields were recorded daily for individual cows. On Weeks 0 and 6, individual milk samples were collected from two consecutive milkings, composited, and analysed for somatic cell counts, fat and true protein concentrations. Plasma concentrations of reactive oxygen metabolites, biological antioxidant potential and non-esterified fatty acids were not affected by Yerba Mate supplementation. Similarly, no effect of Yerba Mate supplementation was noted on milk fat and protein content and on somatic cell counts. This study indicates that supplementation of dairy cows’ diet with Yerba Mate during mid lactation seems to improve milk yield when cows are fed with maize silage; however, even if the effect on milk yield was significant it was quite small and needs to be validated with further studies. Cows’ oxidative status was not affected by Yerba Mate supplementation indicating that the effect of Yerba Mate on their productive performances is not mediated by changes in redox status.
Mastitis in beef cows and the effects of supplemental β-carotene on milk parameters
Authors: Whiteman D. H. , Tomkins N. W. , Young R. J. , Immig I. , Weber G. , Elliott R.
Published: June 2010

Belmont red and Brahman cows (n = 50) were allocated to one of two groups to determine if β-carotene supplementation could reduce the incidence of mastitis and consequently improve calf productivity from birth to weaning. Both groups received a molasses-based supplement ad libitum; the treatment group supplement was fortified with ROVIMIX® β-carotene and ROVIMIX® E50 whereas the control group were provided access to the molasses supplement only. Blood samples were collected from cows pre and post calving and from calves when 84 ± 0.4 days old to measure plasma β-carotene concentration (PCC). Milk samples were collected 7 and 84 days post calving and at weaning and analysed for somatic cell count (SCC) and composition. Supplementation had no significant (P > 0.05) effect on SCC, calf PCC, calf LW gain and LW at weaning. Supplemented cows had significantly (P < 0.05) higher PCC compared with unsupplemented cows (4.9 ± 0.36 v. 3.9 ± 0.24 mg/L, respectively) at weaning. Cows commenced the study in an above-average condition, and combined with unseasonal green forage it is concluded that β-carotene supplementation has no effect on mastitis or calf weaning weight.
Alternative fibre sources for steers and calves fed high-grain feedlot diets
Authors: Beretta V. , Simeone A. , Elizalde J. C. , Franco J. , Bentancur O. , Ferrés A. , Ayçaguer S. , Iriñiz J. , Martínez V.
Published: June 2010

An experiment was conducted to evaluate the effect of fibre source (FS) in high-grain feedlot diets on liveweight gain (LWG) of steers and calves and carcass traits of steers at slaughter. Eighteen steers (330 ± 27.3 kg) and 18 calves (153 ± 11.9 kg) were randomly allotted within animal category to one of three high-grain diets varying in the FS, including either grass hay (H, 66% neutral detergent fibre (NDF)), rice hulls (RH, 85% NDF) or wood chips (W, 90% NDF), and a total mixed ration formulated for equal levels of digestible DM, crude protein and NDF, within category. Animals were individually fed (3 kg DM/100 kg LW, distributed in four meals) during 56 days. The LW increased linearly with time in all treatments (P < 0.01). FS did not affect calves’ LWG (P > 0.05), but it resulted in differences in steers LWG (H: 1.77b; RH: 1.51c; W: 2.02a kg/day, P < 0.05). However, no differences were observed in hot carcass weight (P > 0.05), which resulted in higher carcass yield (P < 0.05) for steers fed RH (55.0%) compared with H (53.5%) and W (53.3%). There was a significant interaction (P < 0.05) for feed : gain ratio, with an improvement of this value observed only for steers fed the W diet. Although varying the FS affected rumination of calves and steers (P < 0.01) and the time spent eating of steers (P < 0.05), it did not represent any constraint for animal production. This study suggests by-products high in fibre content, such as RH and W, could be used in substitution to H in high-grain feedlot diets when fed at equal NDF concentration in the ration, both for calves and steers. Because calves are sometimes grown on a high-concentrate diet during winter before spring grazing, further research is needed to quantify potential residual effects on LWG after they return to pasture.
Does the physiological status of lambs within a twin- and triplet-born litter differ during the first 12 hours of life?
Authors: Kerslake J. I. , Kenyon P. R. , Stafford K. J. , Morris S. T. , Morel P. C. H.
Published: June 2010

This study examined the physical and physiological differences from birth until 12 h of age within twin- and triplet-born litters. In 2005 and 2006, the parturition of 75 twin- and 62 triplet-bearing Romney ewes were observed. After parturition lamb blood samples were taken within 5 min of birth and rectal temperature was measured within 5 min of birth and at 1, 3, 6 and 12 h post-birth. Lamb birth weight, crown–rump length and thoracic-girth circumference were measured at 3 h of age. Lamb birth weight, plasma glucose, fructose, lactate, thyroxine and tri-iodothyronine did not differ (P > 0.05) between the heaviest-twin-born, lightest-twin-born and heaviest-triplet-born lamb. The lightest-triplet-born lambs, however, had lighter (P < 0.001) birthweights, greater (P < 0.001) surface-area-to-birth weight ratio, lower (P < 0.05) rectal temperatures, greater (P < 0.1) lactate concentrations and lower (P < 0.1) plasma thyroid hormone concentrations. These characteristics are known to have a negative impact on the ability of the lamb to maintain its body temperature after birth and may therefore provide some evidence as to why triplet-born lambs display a greater mortality rate than twin-born lambs, and why the lightest-triplet-born lambs have the greatest mortality rate within a litter.
Profitability of calving heifers at 2 compared with 3 years of age and the effect of incidence of assistance at parturition on profitability
Authors: Hickson R. E. , Lopez-Villalobos N. , Kenyon P. R. , Ridler B. J. , Morris S. T.
Published: June 2010

There is potential to increase the profitability of beef-breeding cows in New Zealand by calving heifers for the first time at 2 instead of 3 years of age; however, calving at this earlier age is often associated with an increase in assistance at calving. This study used a simulated farm system within the Grazing Systems Model to estimate the profitability of calving heifers at 2 years of age with various incidences of assistance at calving. Annual profit from the beef cattle herd was greater for primiparous 2-year-old heifers than for 3-year-old primiparous heifers when the incidence of assisted calving in 2-year-old heifers was less than 89%. Replacement rate increased with increased assistance at parturition. These results indicated that a considerable gain in profitability could be made by calving heifers for the first time at 2 instead of 3 years of age, and further gains could be made in herds already calving heifers at 2 years of age by reducing the incidence of assistance at calving.
Growth, feed intake and maternal performance of Angus heifers selected for high or low growth and milk production
Authors: Morris S. T. , Garrick D. J. , Lopez-Villalobos N. , Kenyon P. R. , Burke J. L. , Blair H. T.
Published: June 2010

Weight of calf weaned per cow that incorporates both growth and maternal component traits is an important determinant of profitability for cow–calf production systems. In New Zealand, there is little objective information available on the performance of progeny from bulls selected for either growth or maternal ability when compared under similar pastoral farming conditions. The present experiment produced 84 Angus heifers sired by Angus bulls divergently selected for high (Hi-Gr) or low (Lo-Gr) estimated breeding value (EBV) 600-day weight or high (Hi-Milk) or low (Lo-Milk) 200-day maternal EBV. Each heifer had their liveweight gain from weaning to just before first calving, herbage intake from pasture using the n-alkane method, and maternal performance (calf production after first and second parity) assessed. Liveweights of heifers born to Hi-Gr bulls were generally greater than for all other lines, while there was no difference between Lo-Gr and either of the maternal lines. There was no difference (P > 0.05) in herbage intake between the different genetic lines when measured at Days 310 (days of age from birth) and 880. At Day 400, the Lo-Milk selection line had higher (P < 0.05) intakes than the Hi-Milk, Hi-Gr and Lo-Gr lines. Calves born to the Lo-Gr heifers at the first parity were lighter while the birth weights of calves born at the second parity calving were similar for all the selection lines. Calf weaning weight was lowest (P < 0.05) after both the first and second parity weaning for the Lo-Milk sired heifers. The Lo-Milk heifers produced the least milk at Day 50 during their first lactation while the Hi-Milk heifers produced the most. This experiment confirms that for beef cattle, producers who wish to select bulls to use in their herds based on either high growth rate or high milk EBV, the resultant progeny will outperform those that are average or below average for those particular traits.
Effects of dam parity and rearing rank on the glucose and fat metabolism, and adrenal function of post-pubertal single and twin-ewe progeny
Authors: Pain S. J. , Kenyon P. R. , Morris S. T. , Blair H. T.
Published: June 2010

In an effort to increase the number of lambs produced per ewe’s productive lifetime in New Zealand, an increasing number of ewe lambs (8–9 months old) are being bred. This, in turn, results in an increased proportion of second-parity 2-year-old ewes in New Zealand’s breeding flock, rather than the more usual first-parity 2-year olds. The longer-term effects of dam parity on resulting ewe progeny are of interest and few studies have examined this. The present study was designed to determine whether parity (first or second) of Romney 2-year-old dams had any effect on the metabolic function of their single- and twin-born and reared ewe lamb progeny at 10 months of age. Ten-month-old, single and twin ewe lamb progeny born to first- or second-parity dams (n = 8 per group) were catheterised and given intravenous glucose (0.17 g/kg liveweight) (GTT), insulin (0.15 IU/kg liveweight) (ITT) and epinephrine (1 μg/kg liveweight) (ETT) tolerance tests to assess their glucose and fat metabolism and adrenal function. Rearing rank reduced (P < 0.05) the insulin response of twins to a glucose challenge, but increased (P < 0.05) their glucose response to an insulin challenge. Offspring from first-parity dams had higher (P < 0.05) basal plasma concentrations of cortisol and cortisone, whereas their cortisol/cortisone responses to an insulin challenge were unaffected by either dam parity or rearing rank. Neither dam parity nor rearing rank appeared to influence responses to an epinephrine challenge. The present study suggests that both dam parity and rearing rank alter the glucose and insulin metabolism of the offspring, which may have longer-term impacts on the growth and reproductive efficiency of the animal.
Intake, retention time in the rumen and microbial protein production of Bos indicus steers consuming grasses varying in crude protein content
Authors: Panjaitan T. , Quigley S. P. , McLennan S. R. , Swain T. , Poppi D. P.
Published: June 2010

Feed intake, rumen function, microbial protein (MCP) production and the efficiency of MCP production were determined in steers fed four different forage hays varying markedly in crude protein content. Low quality tropical forage (speargrass and Mitchell grass) hays had lower crude protein content, higher neutral detergent fibre content and lower digestibility than a medium quality tropical forage (pangola grass) hay and a temperate forage (ryegrass) hay. Steers fed speargrass and Mitchell grass hays had lower MCP production (80 and 170 g MCP/day, respectively) and efficiency of MCP production [78 and 79 g MCP/kg digestible organic matter (DOM), respectively] than steers fed pangola grass (328 g MCP/day; 102 g MCP/kg DOM) and ryegrass (627 g MCP/day; 135 g MCP/kg DOM) hays, which was directly related to the supply of DOM and rumen degradable protein. Intake was greatest for ryegrass hay, followed by pangola grass, Mitchell grass and speargrass hays [17.6, 15.6, 10.1 and 5.5 g DM/kg W.day, respectively]. The retention time of DM in the rumen was 72.1, 47.7, 28.6 and 19.1 h for speargrass, Mitchell grass, pangola grass and ryegrass hays, respectively, with a similar trend apparent for the retention time of neutral detergent fibre, lignin, chromium-EDTA and ytterbium labelled digesta. The difference in the protein : energy ratio of absorbed substrates (measured as efficiency of MCP production) did not appear to account for all the differences in intake, nor did a purely physical mechanism.
Urine distribution and grazing behaviour of female sheep and cattle grazing a steep New Zealand hill pasture
Authors: Betteridge Keith , Costall Des , Balladur Sophie , Upsdell Martin , Umemura Kazuhiro
Published: June 2010

Much of the nitrogen (N) excreted by grazing animals is within highly concentrated urine patches. The N that is not used by plants is likely to be lost through leaching, emitted as N gases or added to the soil organic N pool. The present study used custom-made global positioning system (GPS) and urine sensors on 20 non-lactating ewes and 20 non-lactating beef heifers grazing steep hill country to determine potential critical source areas for N loss to the environment. Bite counters on four sheep and five heifers showed when and where animals were eating. Animals were monitored simultaneously on 0.5 ha adjacent paddocks over 8 days. Sheep and cows urinated a mean (±s.d.) of 21.2 ± 6.1 and 9.0 ± 3.0 times/day, respectively. Eating started soon after sunrise and increased during the day to reach a maximum in the hour before sunset, after which the eating activity of both species was near zero for most of the night, except for a short feeding period at around 0300 hours. The urination frequency of sheep increased as eating activity increased during the day, but this relationship was not seen in heifers. Land classified as easy hill country (≤12°) comprised 31% of the sheep paddock and contained 23% of the urination events. In contrast, although the easy hill country comprised 33% of the cattle paddock, 46% of the urine patches were in this area. Although aerial application of N mitigation products to whole paddocks or farms is uneconomic, the results of the present study suggest that mitigation products could possibly be cost-effectively targeted to easy contoured, cattle-grazed hill country areas accessible by farm vehicle.
Influence of grain supplements during winter on liveweight, mohair growth and mohair quality of weaner Angora goats
Authors: McGregor B. A. , Harris R. , Denney G.
Published: June 2010

To identify methods to improve growth and mohair production of weaned Angora goats (mean liveweight 18–20 kg) during their first winter, two supplementary feeding experiments using whole-grain barley and lupins were conducted on a farm in southern New South Wales, in a region where weaner illthrift had been reported. Experiment 1 was a 2 × 2 + 1 factorial with 16 replicate goats; two feeding levels (115 or 230 g/day of whole-barley grain) × two periods of feeding (4 or 8 weeks) + Control (grazing only). Experiment 2 had five treatments × 13 replicate goats; three treatments fed 230 g/day of whole-barley grain for periods of 2 or 3 months and two treatments fed a 50 : 50 mixture of lupin and barley grain at 350 g/day for 2 or 4 months. Goats were individually fed and then all returned together for grazing. There were no effects of feeding in Experiment 1 and variations of feeding 230 g/day of barley in Experiment 2 provided no benefit. Feeding lupin/barley for 4 months increased liveweight (gain 59 g/day), mohair production, mohair fibre diameter and the incidence of medullated fibre. About 25% of this ration was not eaten by eight goats, reducing treatment average intake to 295 g/day. By the end of spring, there was no difference in treatment liveweights. Regression constants indicated that for each 1 μm increase in mean fibre diameter, greasy fleece weight increased 35 g and for each 1 kg increase in pre-shearing liveweight, greasy fleece weight increased 26 g. The results show that Angora weaner goats can grow during winter, provided their energy and protein needs for growth are met. Improved pasture management and higher levels of supplementary feeding to weaned Angoras are indicated compared with current practices on farms in Australia.
Gross margins in Australian mohair enterprises and relationships with farm inputs, productivity and mohair quality
Authors: McGregor B. A. , English W. D.
Published: June 2010

In the absence of financial information on Australian mohair enterprises we aimed to determine the gross margins (per dry sheep equivalent, DSE) and their relationships with farm inputs, productivity and mohair quality in Australian mohair enterprises. Using established Victorian Farm and Sheep Monitor Project protocols we collected data for the financial years 2004–05, 2005–06 and 2006–07 from farmers in south-eastern Australia and made comparisons with data from wool enterprises of similar farm area. Over 3 years the financial returns from mohair exceeded that from wool in terms of $/DSE ($23.0 v. 11.3) and $/ha ($132 v. $116). This result was achieved despite the mohair enterprises grazing their goats far less intensively compared with the grazing intensity of sheep (5.9 v. 10.3–11.1 DSE/ha) and by using far less phosphate fertiliser than used in the wool enterprises (2.2 v. 4.6–6.1 kg P/ha). These differences were counterbalanced by higher prices for mohair compared with fine wool ($13.15/kg v. $8.35/kg clean fibre). Gross margin for the mohair enterprise did not increase as stocking rate increased. Income from mohair sales declined as the proportion of does in the flock increased. Increasing the proportion of does in the flock was associated with a decline in the average price of mohair ($16/kg greasy at 42% does to $8/kg greasy at 83% does in the flock). This decline was closely associated with the increasing proportion of the total amount of mohair coarser than 34.0 µm (either fine hair or hair) plus stained mohair. The variation in profitability between farms indicates significant scope for many mohair enterprises to increase profit. A focus on producing finer quality mohair will increase mohair profitability.
Behavioural and physiological responses of laying hens to humans
Authors: Edwards L. E. , Botheras N. A. , Coleman G. J. , Hemsworth P. H.
Published: June 2010

Human interactions, particularly negative ones, affect the behaviour and physiology of laying hens, with possible implications for bird productivity and welfare. The present experiment investigated the effects of handling on the behaviour and plasma corticosterone concentrations of laying hens. A 2 × 2 × 3 factorial design was used to study the following three main effects: human contact during rearing [an additional 12 min of human contact per day (AC) or no additional contact (MC) during rearing]; handling quality in adulthood [brief daily exposure to positive (+ve) or negative (–ve) visual contact with a human]; and handling proximity in adulthood [handling-quality treatment (+ve or –ve) imposed at the following three distances from the birds: Near, 0–45 cm; Middle, 45–75 cm, or Far, 75–105 cm]. AC during rearing resulted in reduced avoidance behaviour of humans during adulthood, whereas handling imposed at the Far level resulted in greater avoidance behaviour than did handling at the Near or Middle level. The quality of the handling (+ve or –ve) had little effect on avoidance behaviour; however, there was a trend (P = 0.07) for hens receiving +ve handling to have a lower corticosterone response to human contact than those receiving –ve handling. These results demonstrate that visual human contact can influence the avoidance behaviour of laying hens.
Nutritional research to meet future challenges
Authors: Poppi D. P. , McLennan S. R.
Published: June 2010

Nutrition is a mature science with well established principles for energy, protein and mineral metabolism based on known metabolic pathways. The quantitative requirements are summarised within various international feeding standards and models. However, when these are applied to specific circumstances, especially in northern Australia, the response of the animal to nutrient supply does not always agree with that predicted from the feeding standards or the error of prediction is not sufficiently accurate for practical use. There is a need for the continual testing of these relationships within production systems. Molecular methods have the potential to discover new metabolic relationships within tissues and characterise the microbial ecology and its relationship to rumen function. Suitable problem models based on growth, meat quality, reproduction, milk and fibre production, and environmental consequences need to be identified. We suggest that production systems designed to meet market weight for age specifications, growth paths and compensatory growth, skeletal growth, parasites, fatty acid isomers, adaptation to low crude protein diets, rumen microbial ecology, epigenetics, remote data acquisition and animal management, greenhouse gas emission, and C balance of various production systems are important problem models, the research of which will benefit the future of the livestock industries in Australia.
Measuring colour and photostability of small fleece wool samples
Authors: Millington K. R. , King A. L.
Published: June 2010

A convenient method for measuring the clean colour (Y and Y-Z) and photostability Δ(Y-Z) of small samples of fleece wool (0.5 g) is described. Scoured wool samples are compressed to a constant density in disposable polymethyl methacrylate spectrophotometer cells and the wool colour is measured using a standard textile laboratory reflectance spectrophotometer. Packing scoured wool into cells ensures that the irradiated fibre surface is robust and individual fibres are unable to move relative to one another during irradiation and measurement. A UVB (280–320 nm) source was used to ensure all samples regardless of initial yellowness were yellowed following exposure and photobleaching was avoided. An apparatus capable of irradiating up to 48 scoured wool samples in one batch is described. The precision of photostability measurements was assessed and the relative error in Δ(Y-Z) was 5.7%. An initial study on 75 fleece wool samples with a high range of initial yellowness showed a moderate linear correlation (R2 = 0.68) between initial yellowness and Δ(Y-Z).
Training Merino sheep to respond to visual and auditory cues
Authors: Taylor Donnalee B. , Brown Wendy Y. , Price Ian R. , Hinch Geoff N.
Published: June 2010

The feasibility of training sheep to approach a stimulus was investigated in three experimental groups and a control group of fine wool Merino sheep (n = 11 in each group). The experimental groups (n = 11) were trained to approach either a visual (V), auditory (A), or visual + auditory (V+A) stimulus over eight training sessions and were subsequently tested in a T-maze for memory retention on six occasions over a 4-month period. Four testing occasions were spaced at greater than 30 days apart while two were less than 3 days apart. Sheep learned to approach the cues during the training period and the tests indicated that the sheep retained memory of the cues for over 130 days without reinforcement. The controls received no contingency exposure and made no choice in the T-maze test. The proportion of correct stimulus choices (±s.e.m.) in the T-maze averaged over the four longer-spaced testing occasions were V 0.61 (0.06), A 0.50 (0.11), V+A 0.77 (0.04). These differences approached significance (P = 0.058). Sheep trained to the V+A stimulus performed significantly (P < 0.05) better in the T-maze than sheep trained to the A stimulus alone. Comparisons over the shorter-spaced testing durations indicated that the sheep quickly learnt not to approach the stimulus (temporary extinction) when no food reward was available. Individual temperament of the animals was not related to their learning. This study highlights the potential for the use of V and A cues in manipulating the movement of sheep which may be useful for farm management purposes.
Evaluating development options for a rain-fed dairy farm in Gippsland
Authors: Armstrong D. P. , Tarrant K. A. , Ho C. K. M. , Malcolm L. R. , Wales W. J.
Published: June 2010

A case study and modelling approach was used to examine options for a dairy farm in the high rainfall area of Gippsland (southern Victoria) that would enable it to maintain or increase profit in the future (next 5–10 years) in the face of a continuing ‘cost-price squeeze’. The economic performance of the business under a range of development options, identified by an ‘expert panel’, was analysed for a planning period of 10 years. The options analysed were: (i) increased herd size without purchasing more land, (ii) increased milking area and (iii) purchasing non-milking area for production of conserved fodder. Expanding the milking area by purchasing more land without significantly increasing herd size (reducing stocking rate from 2.5 to 2.1 cows/ha) increased annual operating profit without increasing variability in profit between years compared with the base farm. The increased profit resulted from a reduction in the amount of purchased feed. The purchase of an additional outblock for fodder production reduced risk compared with the base farm system, but did not improve the profitability of the farm system. Other options significantly reduced profit while increasing risk. The most appropriate changes to dairy farm businesses in response to changes in the operating environment will vary from farm to farm. The analysis suggested that there may be an alternate path to the historical trends of larger and more intensive operations. It has also highlighted the importance of home-grown feed and efficient supplement use to increase or maintain profitability in the medium term.
Psammaplin Metabolites New and Old: An NMR Study Involving Chiral Sulfur Chemistry
Authors: Graham Sharna K. , Lambert Lynette K. , Pierens Gregory K. , Hooper John N. A. , Garson Mary J.
Published: June 2010

The new metabolite psammaplin N (8) that contains a sulfoxide moiety has been isolated together with psammaplins A (1), I (4a), and J (2) from a specimen of the marine sponge Aplysinella rhax (order Verongida family Aplysinidae) collected in South East Queensland. An NMR study on psammaplin J reveals its facile conversion to psammaplins A and I when exposed to methanol.
Structural Variations to the 9-N-Methyladeninium Diterpenoid Hybrid Commonly Isolated from Agelas Sponges
Authors: Calcul Laurent , Tenney Karen , Ratnam Joseline , McKerrow James H. , Crews Phillip
Published: June 2010

Four novel 9-N-methyladeninium diterpenoids, agelasine M (3), 2-oxo-agelasine B (4), gelasine A (5), and gelasine B (6) accompanied by the known-agelasine B (1) and F (2) were isolated from the marine sponge Agelas sp. collected in Papua New Guinea. Compounds 3–6 represent higher unsaturated 9-N-methyladeninium bicyclic diterpenoid derivatives including 5 and 6 as unusual norditerpenoid-agelasines. Their structures were elucidated through detailed physical data analyses and comparison with literature properties. All pure compounds were evaluated for inhibitory activity against Trypanosoma brucei as well as for cytotoxicity against Jurkat cells.
Synthesis, Characterization, and Photoluminescent Properties of ZnII, CdII, and HgII Complexes with N,O Hybrid Pyrazole Ligand
Authors: Guerrero Miguel , Pons Josefina , Font-Bardia Mercè , Calvet Teresa , Ros Josep
Published: June 2010

The synthesis and characterization by elemental analysis, mass spectrometry, conductance measurements, IR, 1H, and 13C NMR spectroscopies of compounds with the general formula [MCl2(L)2], where M = Zn (1), Cd (2), or Hg (3) and L = 1-(2-hydroxyethyl)-3,5-dimethylpyrazole have been described. The 113Cd{1H} and 199Hg{1H} NMR spectra were also measured to investigate the coordination environment of the metal in solution. The structure of complex [ZnCl2(L)2] was determined by single-crystal structure analysis. The extended structure revealed a 1D chain caused by several O–H···CH3 intermolecular interactions. Moreover, we have determined the fluorescent properties of complexes 1–3; it was found that L demonstrates the higher sensibility to HgII ion, one of the most toxic agent in the environment. The preliminary results indicate that L could have a promising future for the detection of mercury in real environmental samples.
Synthesis and Structure Reassessment of Psammopemmin A
Authors: Lebar Matthew D. , Baker Bill J.
Published: June 2010

We have isolated meridianins A, B, C, and E from the Antarctic tunicate Synoicum sp. In the process of verifying the structure of these compounds it was noted that the physical data reported for meridianins bore a striking resemblance to that of psammopemmins. The psammopemmins are alkaloids bearing similar structures to the meridianins, but reported from the Antarctic sponge Psammopemma sp. To verify the structure originally proposed for psammopemmin A, the compound was synthesized. By comparing the 1H and 13C NMR data of reported and synthetic psammopemmin A with that of meridianin A, we infer that the correct structure of psammopemmin A isolated from Psammopemma sp. is actually that of meridianin A.
Australin E Isolated from the Soft Coral Cladiella sp. Collected in Pohnpei Activates the Inositol 5-Phosphatase SHIP1
Authors: Williams David E. , Amlani Ashraf , Dewi Ariyanti S. , Patrick Brian O. , van Ofwegen Leen , Mui Alice L.-F. , Andersen Raymond J.
Published: June 2010

Four new diterpenoids, australins E–H (1–4), have been isolated from the marine soft coral Cladiella sp. collected in Pohnpei. The structures of 1–4 were elucidated by analysis of their NMR and mass spectrometry data combined with an X-ray diffraction analysis of australin E (1). Australin E (1) activates the inositol 5-phosphatase SHIP1 in vitro.
Identification of the Cyclase Product and its First Oxidation Product in the Biosynthesis of Fuscol and Fuscosides
Authors: Saleh Maysoon B. , Kerr Russell G.
Published: June 2010

Fuscol and the related fuscosides are diterpenes isolated from the Caribbean gorgonian Eunicea fusca, which exhibit potent anti-inflammatory activity with a selective action against leukotriene production in murine models. This report describes the isolation and characterization of the diterpene cyclase product leading to these natural products. The cyclase product has been assigned the trivial name eunicene A and was identified through a radioactivity-guided isolation. Additional biosynthetic experiments conducted by incubating a cell-free extract of E. fusca with 3H-labelled metabolites confirmed the involvement of this unsaturated hydrocarbon in the production of fuscol and fuscosides.
Aplysiols C - E, Brominated Triterpene Polyethers from the Marine Alga Chondria armata and a Revision of the Structure of Aplysiol B
Authors: Ola Antonius R. B. , Babey Anna-Marie , Motti Cherie , Bowden Bruce F.
Published: June 2010

Three new brominated triterpene polyethers, aplysiols C–E (1–3), were isolated from extracts of the red alga Chondria armata. Structures were determined by comparison with the closely related metabolite, aplysiol B, which was previously reported from the anaspidean mollusc Aplysia dactylomela. The relative stereochemistry of the tetracyclic ring system was determined from 1D gradient selective NOESY experiments and from biogenetic considerations that support a revision of the stereochemistry proposed for aplysiol B. In addition, three known brominated C15 acetogenin acetylenic ethers: (–)-pinnatifidenyne, (+)-laurenyne, and (+)-obtusenyne, two brominated diterpenes: (–)-ent-angasiol and (–)-ent-angasiol acetate, and the symmetrical halogenated triterpene polyether intricatetraol were isolated.
A New 3D Metal - Organic Framework Containing Chelidamic Acid with Unusual (3,6)-Connected Topology: Synthesis, Crystal Structure, and Optical Properties
Authors: Zou Jian-Ping , Li Ming-Jun , Xing Qiu-Ju , Wen Zhen-Hai , Zeng Gui-Sheng , Zhang Ai-Qing , Peng Qiang , Guo Guo-Cong
Published: June 2010

A new metal–organic framework [(LaL)·3H2O]n (L = chelidamic acid) with good optical properties was obtained through the hydrothermal reaction. It is the third three-dimensional framework constructed from chelidamic acid and presents a rare (3,6)-connected topology with Schläfli symbol (42.6)2(44.62.87.102).
Marine Natural Products Chemistry: Past, Present, and Future
Authors: Capon Robert J.
Published: June 2010

Marine metabolites represent an extraordinary pre-assembled pool of biologically active molecular diversity, programmed by evolution to be potent and selective modulators of key biopolymers, cells, tissues, organs, and animals. Over the past half-century the study of these metabolites (Marine Natural Products Chemistry) has evolved into a multidisciplinary endeavour, rich in complementary technologies and methodologies, and embracing diverse objectives and outcomes.
Structures of actin-bound Wiskott-Aldrich syndrome protein homology 2 (WH2) domains of Spire and the implication for filament nucleation
Authors: Ducka Anna M. , Joel Peteranne , Popowicz Grzegorz M. , Trybus Kathleen M. , Schleicher Michael , Noegel Angelika A. , Huber Robert , Holak Tad A. , Sitar Tomasz
Published: June 2010

Three classes of proteins are known to nucleate new filaments: the Arp2/3 complex, formins, and the third group of proteins that contain
ca.
25 amino acid long actin-binding Wiskott-Aldrich syndrome protein homology 2 domains, called the WH2 repeats. Crystal structures of the complexes between the actin-binding WH2 repeats of the Spire protein and actin were determined for the Spire single WH2 domain D, the double (SpirCD), triple (SpirBCD), quadruple (SpirABCD) domains, and an artificial Spire WH2 construct comprising three identical D repeats (SpirDDD). SpirCD represents the minimal functional core of Spire that can nucleate actin filaments. Packing in the crystals of the actin complexes with SpirCD, SpirBCD, SpirABCD, and SpirDDD shows the presence of two types of assemblies, “side-to-side” and “straight-longitudinal,” which can serve as actin filament nuclei. The principal feature of these structures is their loose, open conformations, in which the sides of actins that normally constitute the inner interface core of a filament are flipped inside out. These Spire structures are distant from those seen in the filamentous nuclei of Arp2/3, formins, and in the F-actin filament.