bluuebunny/crossref_metadata_2025 huggingface dataset:
Selective adduct formation by furan chemical ionization reagent in gas chromatography ion trap mass spectrometry
Authors: Tzing Shin‐Hwa , Ghule Anil , Chang Jia‐Yaw , Ling Yong‐Chien
Published: November 2004

The analytical potential of furan as a chemical ionization (CI) reagent was evaluated for selectivity with nine monosubstituted naphthalene compounds. The ion–molecule reactions of furan and tetrahydrofuran (THF) were compared with those of methane, methanol and acetonitrile (prominently producing [M + H]+ ion base peaks) with naphthalene compounds in chemical ionization mass spectrometry (CI‐MS). Reactions with furan predominantly show M+ and [M + 39]+ ions. Based on this phenomenon, investigations were carried out for some of the molecular factors such as proton affinity, substituent effects and the preferred site of [C3H3]+ ion attachment that influence reactivity in furan CI. High selectivity with different substituents is observed in the formation of [M + 39]+ adduct ion, suggesting its usefulness as selective ionization reagent liquid. The selectivity and sensitivity are illustrated in the analysis of mixture of amino acids. Furthermore, the structure determination and reaction mechanism study is characterized by collision‐activated dissociation experiments in CI‐MS/MS and CI‐MS/MS/MS. Copyright © 2003 John Wiley & Sons, Ltd.
Characterization of plant oligosaccharides by matrix‐assisted laser desorption/ionization and electrospray mass spectrometry
Authors: Matamoros Fernández Lobvi E. , Obel Nicolai , Scheller Henrik Vibe , Roepstorff Peter
Published: November 2004

Structural characterization of arabinoxylans from wheat by matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) and electrospray ionization (ESI) mass spectrometry using a Q‐TOF mass analyser (ESI‐Q‐TOF) or an ion trap (IT) mass analyser is presented. An arabinoxylan sample digested with endoxylanase A was analysed using MALDI‐TOF mass spectrometry (MS), resulting in the identification of molecular ions for structures with up to 22 monosaccharide residues. As the two‐component monosaccharides xylose and arabinose are isobaric, structures differing in the number of arabinose branching residues were indistinguishable based on molecular mass and also fragmentation pattern upon collision‐induced dissociation (CID). Permethylation followed by ESI‐CID analyses using ITMS was performed to obtain structural information regarding the number of arabinose branching residues and their spatial arrangement along the xylose backbone. Analysis of the signal corresponding to an oligomer with six monosaccharide residues showed the presence of at least four isomeric structures differing in degree of branching and position of the branched residue relative to the cleavage site of the enzyme. This is the first demonstration of the use of ESI‐ITMS for the structural characterization of arabinoxylan mixtures. Copyright © 2003 John Wiley & Sons, Ltd.
Liquid chromatography/atmospheric pressure ionization–mass spectrometry in drug metabolism studies
Authors: Kostiainen R. , Kotiaho T. , Kuuranne T. , Auriola S.
Published: November 2004

The study of the metabolic fate of drugs is an essential and important part of the drug development process. The analysis of metabolites is a challenging task and several different analytical methods have been used in these studies. However, after the introduction of the atmospheric pressure ionization (API) technique, electrospray and atmospheric pressure chemical ionization, liquid chromatography/mass spectrometry (LC/MS) has become an important and widely used method in the analysis of metabolites owing to its superior specificity, sensitivity and efficiency. In this paper the feasibility of LC/API‐MS techniques in the identification, structure characterization and quantitation of drug metabolites is reviewed. Sample preparation, LC techniques, isotope labeling, suitability of different MS techniques, such as tandem mass spectrometry, and high‐resolution MS in drug metabolite analysis, are summarized and discussed. Automation of data acquisition and interpretation, special techniques and possible future trends are also the topics of the review. Copyright © 2003 John Wiley & Sons, Ltd.
Cover Picture: Macromol. Biosci. 11/2004
Authors: Sannigrahi Biswajit , McGeady Paul , Khan Ishrat M.
Published: November 2004

Cover: Helical poly(3‐methyl‐4‐vinylpyridine)(P3M4VP)/amino acid complexes have been prepared via acid‐base interaction of the achiral polymer with D and L amino acids. Formation of the helical structures was quite rapid and within a few minutes of the complexation process, well developed CD spectra were observed. Furthermore the complexes are compatible with HeLa cells, they minimally interfere with the adhesion and growth of HeLa cells on complex surfaces.

Further details can be found in the Full Paper by B. Sannigrahi, P. McGeady, and I. M. Khan* on page 999.
Effects of velocity on maximal torque production in poststroke hemiparesis
Authors: Lum Peter S. , Patten Carolynn , Kothari Dhara , Yap Ruth
Published: November 2004

Impaired torque production is a major physical impairment following stroke, and has been studied extensively in isometric conditions. However, functional use of a limb requires torque production during movement, and the effects of velocity on maximal torque production may be abnormally enhanced in the paretic limb. The purpose of this study was to quantify the effects of movement velocity on maximal torque production during isokinetic, concentric flexion and extension of the elbow in poststroke subjects. Three speeds were tested (30, 75, 120 deg/s) over a 100‐deg range of motion. To control for strength variations between subjects and limbs, isokinetic torques were normalized by peak isometric torque. As flexion velocity increased, paretic limb torque decreased at a greater rate than in the unaffected limb. During extension, paretic limb torque was much lower than torque in the unaffected limb at all speeds. In both flexion and extension, the disparity between limbs in the constant‐velocity torque–angle curves became more pronounced as velocity increased. Torque decreased 44% ± 7% in flexion and 63% ± 9% in extension as velocity increased from 30 to 120 deg/s, whereas the corresponding decreases in the unaffected limb were only 9% ± 5% in flexion and 16% ± 4% in extension. No electromyographic (EMG) abnormalities were observed during flexion. During extension, EMG data provided evidence for abnormally increased antagonist coactivation in brachioradialis and markedly reduced activation in triceps as potential contributors to the decreased extension torques. The finding that movement velocity produces large deficits in maximal torque might explain why functional use of the paretic limb is often impaired even though isometric strength appears adequate. Muscle Nerve, 2004
An interesting contrast: effects of maleic acid and styrene on the synthesis of functional poly(methyl methacrylate) microspheres
Authors: Li Songjun , Hu Jie , Liu Bailing
Published: November 2004

The effects of maleic acid and styrene on the polymerization of methyl methacrylate (MMA) have been studied. Both comonomers play a considerable role in terms of particle size and MMA conversion. The polymerization of MMA in the presence of maleic acid can result in larger particles and a higher MMA conversion. However, in the presence of styrene, the polymerization process yields smaller particles and low MMA conversion. This can be related to the different properties of maleic acid and styrene. Maleic acid, a hydrophilic and electron‐withdrawing comonomer, can play a positive role in stabilizing the particles and increasing MMA activation. However, for styrene, these effects are reversed due to its opposite properties. The change in particle size may be caused by the change in particle stabilization. The change of MMA conversion can be kinetically attributed to the effects of maleic acid and styrene on the activation process. Copyright © 2004 Society of Chemical Industry
1,5‐Diphenyl‐1,4‐diyn‐3‐one: A highly efficient photoinitiator
Authors: Liska Robert , Seidl Bernhard
Published: November 2004

In a continuation of our research on new chromophores for photoinitiators (PIs), we investigated a triple‐bond‐containing benzophenone derivative. 1,5‐Diphenyl‐1,4‐pentadiyn‐3‐one (2) was prepared from phenylacetylene and ethyl formate by a one‐pot reaction. Differential scanning photocalorimetry experiments in lauryl acrylate of 2 showed surprisingly high activity for the double‐bond conversion and rate of polymerization at the lowest PI concentrations and even without any coinitiator. By the application of monomers with abstractable hydrogens, significant improvement in the photoreactivity was observed. Ultraviolet–visible spectroscopy revealed strong absorption up to 350 nm. Steady‐state photolysis experiments proved that the photochemistry of this compound was faster than that of benzophenone. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 101–111, 2005
A metrics suite for grammar‐based software
Authors: Power James F. , Malloy Brian A.
Published: November 2004

One approach to measuring and managing the complexity of software, as it evolves over time, is to exploit software metrics. Metrics have been used to estimate the complexity of the maintenance effort, to facilitate change impact analysis, and as an indicator for automatic detection of a transformation that can improve the quality of a system. However, there has been little effort directed at applying software metrics to the maintenance of grammar‐based software applications, such as compilers, editors, program comprehension tools and embedded systems. In this paper, we adapt the software metrics that are commonly used to measure program complexity and apply them to the measurement of the complexity of grammar‐based software applications. Since the behaviour of a grammar‐based application is typically choreographed by the grammar rules, the measure of complexity that our metrics provide can guide maintainers in locating problematic areas in grammar‐based applications. Copyright © 2004 John Wiley & Sons, Ltd.
Mistargeted MRPΔF728 mutant is rescued by intracellular GSH
Authors: Buyse Frédéric , Vandenbranden Michel , Ruysschaert Jean-Marie
Published: November 2004

The most common cystic fibrosis‐causing mutation is the deletion of the widely conserved phenylalanine 508 (ΔF508) of CFTR. The mutant is unable to fold correctly and to transit to the plasma membrane. MRP1 belongs to the same subfamily of ABC proteins as CFTR and confers resistance to a wide range of chemotherapeutic drugs. By analogy, phenylalanine 728 was deleted in MRP1. Our results shown that MRPΔF728 is correctly targeted to the plasma membrane, actively transports doxorubicin (DOX) and vincristine (VCR) and shares a structure identical to MRP1. Intracellular GSH depletion however results in a mistargeted mutant that is retained into the cytoplasm, while in the same conditions wild‐type MRP1 is correctly routed to the plasma membrane. The GSH‐protein complex could adopt a stable conformation protected against proteolytic degradation and correctly targeted to the plasma membrane.
Genetic variability of glutamate-gated chloride channel genes in ivermectin-susceptible and -resistant strains ofCooperia oncophora
Authors: NJUE A. I. , PRICHARD R. K.
Published: November 2004

The glutamate-gated chloride channels (GluCls) are members of the ligand-gated ion channel superfamily that are thought to be involved in the mode of action of ivermectin and mechanism of resistance. Using reverse-transcriptase PCR techniques, 2 full-length GluCl cDNAs, encoding GluClα3 and GluClβ subunits, were cloned fromCooperia oncophora, a nematode parasite of cattle. The two sequences show a high degree of identity to similar subunits from other nematodes. TheC. oncophoraGluClα3 subunit is most closely related to theHaemonchus contortusGluClα3B subunit, whileC. oncophoraGluClβ subunit shares high sequence identity with theH. contortusGluClβ subunit. Using single-strand conformation polymorphism, the genetic variability of these two genes was analysed in an ivermectin-susceptible isolate and an ivermectin-resistant field isolate ofC. oncophora. Statistical analysis suggested an association between theC. oncophora GluClα3gene and ivermectin resistance. No such association was seen with theGluClβ gene.
The effects of informal care on paid-work participation in Great Britain: a lifecourse perspective
Authors: HENZ URSULA
Published: November 2004

Several recent studies have documented a negative relationship between informal care-giving and labour market attachment in Great Britain. This paper examines the relationship from a longitudinal perspective using data from the Great Britain 1994–95 Family and Working Lives Survey. The first part of the paper studies the timing of informal care-giving to a sick, disabled or elderly person. This information is used in the second part to examine the effects of caring on employment. The results show that most carers look after only one dependant during their lives, and only around one-fifth to one-third look after a second dependant before the age of 65 years. Of all informal carers, about one-third had not been employed when they started caring for the first time in their lives, another third said that caring had no effect on their work arrangements, and about one-third reported one or several effects on their work arrangements, most commonly that they stopped working. Multivariate analyses show that semi-routine and routine manual workers report the strongest effects of care-giving. Part-time workers were more likely than full-time workers to reduce their hours of paid employment when they started caring.
Effects of time averaging on climate regimes
Authors: Teng Qiaobin , Monahan Adam H. , Fyfe John C.
Published: November 2004

The effects of different temporal averaging timescales on the regime structure of the extratropical Northern Hemisphere atmosphere in reanalysis data and in a global climate model are considered. It is shown that temporal averaging can significantly change the regime structure when the averaging timescale is considerably longer than the intrinsic regime residence times. These effects are explained using a simple stochastic model of motion in a 3‐well potential. This study highlights the importance of the careful choice of averaging timescales in the analysis of non‐Gaussian structure in climate data.
The transition of the monsoonal and the N Atlantic climate system off NW Africa during the Holocene
Authors: Kuhlmann Holger , Meggers Helge , Freudenthal Tim , Wefer Gerold
Published: November 2004

The northward extent of the influence of the W African monsoon during humid periods of interglacials is subject to investigations highlighting feedback mechanisms, such as vegetation. To detect this regional variation and the climate system acting farther to the north will be the aim of this paper focussing on the Holocene. We present two very high‐resolution Holocene sediment records off NW Africa located at 31°N and 27°N. The well‐known mid‐Holocene climate change from the “African Humid Period” to present arid conditions is well reflected by the terrigenous input in the southern core. In contrast, in the northern core spectral and wavelet analyses indicate a periodic oscillation of about 900 years of the terrigenous input throughout the last 9000 years B.P. We conclude that the W African monsoonal influence characterized by the abrupt climatic change at 5000 years B.P. can be separated from the influence of the N Atlantic climate system reflected by a periodic oscillation throughout the Holocene.
Climatically driven changes in oceanic processes throughout the equatorial Pacific
Authors: Paytan Adina , Lyle Mitch , Mix Alan , Chase Zanna
Published: November 2004

The mass accumulation rates of sedimentary components (carbonate, organic carbon, opal, barite, reactive phosphate, iron, terrigenous minerals, etc.) are used in many paleoceanographic reconstructions to learn about temporal and spatial changes in surficial Earth processes including wind stress and direction, oceanic circulation, weathering rates, marine productivity and ecosystem structure, climate change, and more. In most studies it is assumed/desired that the sediment accumulation represents the production and deposition of particles from the overlying water column since substantial horizontal transport imply homogenization of paleoceanographic proxies and little confidence in any paleoceanographic time series. In this note we highlight some discrepancies between the different approaches used to reconstruct sediment mass accumulation rates and specifically discuss the consequences of these discrepancies to the reconstruction of paleoproductivity in the equatorial Pacific. We pose research questions and suggest possible approaches/research strategies for the community to solve them.
Effect of phosphate supply and competition from grasses on growth and nitrogen fixation of Medicago trunculata
Authors: Dahmane ABK , Graham RD
Published: November 2004

Medic plants and ryegrass were grown in small pots in a glasshouse in monoculture (six plants per pot) or in mixture (three plants of each species) at eight rates of phosphate application. After 10 weeks, the rate of nitrogen fixation was estimated by the acetylene reduction (AR) technique on the intact plants in soil, after which the plants were harvested, both shoots and roots. The yield of medic, in both monoculture and mixture, increased with increasing rate of phosphate application to an optimum at a level of 160 ppm phosphorus and then decreased again at higher phosphate levels. AR activity was similarly dependent on phosphate application and was optimal at the same phosphate level as was yield. AR activity was extremely low in the ryegrass monocultures, the yield of which was optimized at only 10 ppm phosphorus. The community x phosphate interaction on AR activity per plant of medic was not statistically significant, there being considerable variability in this measurement; the suppression of nitrogen fixation by competition from ryegrass near its own phosphate optimum was not therefore established in this study, but remains a possibility. Ryegrass plants benefited individually from growing in mixed culture with the legume, producing as much shoot dry matter from three plants in mixture as from six in monoculture. The advantage in mixture was due either to reduced competition offered by medic or to transfer of fixed nitrogen from legume to grass. Higher concentrations and contents of nitrogen per plant in mixture provided circumstantial evidence for the latter. However, on a pot basis, nitrogen content of ryegrass was similar in pure culture and in mixture. The relevance of the data to the results of a survey of farmers' fields is discussed.
Milk replacers containing soybean protein isolates or concentrates: nitrogen digestibility and utilization by preruminant lambs
Authors: Malouf NM , Walker DM
Published: November 2004

Preruminant male crossbred lambs, aged 2-5 days at the start of the experiment, were given milk replacers containing between 0.25 and 0.29 of the total energy as protein. A comparison of milk replacers containing either soybean isolates or concentrates as the sole source of protein showed that, while the apparent digestibilities of dry matter and nitrogen were significantly higher for diets containing isolates, the efficiencies of retention of the apparently digested nitrogen were significantly higher for the concentrate diets. The net result was no significant difference in nitrogen balance between the diets. The milk replacers were accepted readily by the lambs, and intakes of gross energy of up to three times the maintenance requirement were attained without difficulty. Nitrogen balances of lambs given a milk replacer based on a soybean concentrate were not significantly improved by supplementation of the diet with lysine, in addition to methionine. Similarly, the nitrogen balances of lambs given a soybean isolate-based milk replacer, plus methionine, were unaffected when one of five supplementary amino acids (Lys, Thr, Val, Isol, Leu) was omitted in turn from the diet.
Crop loss assessment studies on the effects of barley yellow dwarf virus in wheat in Victoria
Authors: Smith PR , Sward RJ
Published: November 2004

The effect of barley yellow dwarf virus (BYDV) infection on grain yield of wheat, cv. Olympic, was determined over 3 years at three sites in Victoria in field plots inoculated with infective Rhopalosiphum padi (L.). Inoculation before tillering lowered grain yields by 9-79 %, whereas inoculation at early stem extension lowered yields by only 6-9 %. There was a linear relationship between the percentage of plants infected with BYDV at an early stage of growth and grain yield at all sites. Other components of yield affected included numbers of tillers, numbers of heads with sterile terminal spikelets, grain weight per head and weight of individual grains.
A physiological analysis of the effect of sowing density on the growth rate of subterranean clover
Authors: Prioul J-L , Silsbury JH
Published: November 2004

The initial planting density of subterranean clover swards is known to affect the subsequent crop growth rate in such a way that a low density crop reaches the same final yield as does one sown at high density. To explain this phenomenon, daily carbon influxes and effluxes were measured during the growth of 'low' and 'high' density swards in a constant environment. The growth characteristics of individual plants in the sward and the photosynthetic responses of individual leaves to light were measured during ontogeny. Good agreement was found between the growth curves reconstructed from daily carbon increment and growth curves previously derived from dry matter sampling. The crop growth rate of a low density sward was found to be higher than that of a high density sward, and this is shown to be due to a lower respiratory loss. The high respiration rate of a high density crop can be attributed to plant mortality when dry matter density is higher than 400 g m-2. The photosynthetic light response curves of individual leaves at the top of the canopy were not found to be affected by the initial planting density, which suggests that subterranean clover plants are extremely well adapted to growth under sward conditions.
Growth analysis of poppies (Papaver somniferum L.)
Authors: Chung B
Published: November 2004

A growth analysis study of the effects of two contrasting environments on the yield of field grown poppies (Papaver somnifevum L.) was undertaken using regression techniques. The change in total plant yield during the 1977-78 season was found to be adequately fitted by a cubic polynomial equation. In contrast, the change in total plant yield during the 1976-77 season and the development of leaf area index in both seasons were found to be adequately fitted by quartic polynomial equations. The total plant yield in the 1977-78 season was considerably higher than that in the 1976-77 season from the beginning of December to dry maturity with a maximum difference of 2 200 kg/ha on 15 January. This yield difference can be attributed to the higher crop growth rate in the 1977-78 season from 30 November to 18 January with a maximum difference of 12 g/m2/day on 30 December. Leaf area index was considered to be more important than net assimilation rate in influencing the crop growth rate up to 20 December. The differences in leaf area between the two seasons could be attributed to the climatic conditions. Under Tasmanian conditions, poppy yields could be expected to be reasonably stable from year to year, provided that the crop is encouraged to grow at its optimum during the whole season.
Phenology of sunflower cultivars. II. Controlled-environment studies of temperature and photoperiod effects
Authors: Goyne PJ , Hammer GL
Published: November 2004

The effects of photoperiod and temperature on the phenology of the open-pollinated sunflower cultivar, Sunfola 68-2, the hybrid, Hysun 30, and its parents, were studied in five experiments using the CSIRO Canberra phytotron. Photoperiod and temperature influenced the number of days to first anthesis (FA) mainly during the emergence (E) to head-visible (HV) stage of growth. Leaf counts and plant height measurements supported this finding. There were major differences in the responses of the two cultivars to short photoperiods and low temperatures. The differences were removed by increasing temperature to a regimen of 27/22�C (day/night) or by increasing the photoperiod to 14 h. At low temperature, Sunfola 68-2 showed little response to photoperiods of between 10 and 14 h, whereas Hysun 30 showed a marked increase in duration of the E-HV stage for photoperiods shorter than 14 h. At photoperiods of 10 and 12 h there was a general decline in all measured attributes with increases in temperature, except the number of leaves on Sunfola 68-2 which remained relatively constant. Hysun 30 was similar to its male parent ('R' line) in response to photoperiod and temperature. The experiments suggest that the effects of radiation levels on sunflower phenology and photoperiod x temperature interactions in the 14-18 h photoperiod range require further investigation.
Associations between individual gliadin proteins and quality, agronomic and morphological attributes of wheat cultivars
Authors: Wrigley CW , Robinson PJ , Williams WT
Published: November 2004

The gliadin protein compositions of 79 wheat genotypes from Australia, New Zealand and North America, and one rye cultivar have been examined by starch gel electrophoresis. Interrelationships in the patterns thus obtained were investigated using a computer-generated inverse minimum spanning tree. Certain components were frequently found to occur together, presumably because their synthesis is controlled by closely linked genes. In addition, by using a network-generating program, associations between gliadins and many morphological (plant, head and grain), agronomic and quality attributes were studied. In many cases, specific gliadin components were found to be closely associated with certain attributes. In such cases a direct cause and effect cannot be inferred, but the approach indicates associations that warrant further study.
Relationships between Australian wheats on the basis of pedigree, grain protein composition, grain quality and morphology
Authors: Wrigley CW , Robinson PJ , Williams WT
Published: November 2004

A procedure using numerical analysis has been devised for illustrating ancestry relationships. It has been applied to 60 wheat cultivars recently grown in Australia. The program also permits the grouping of parents to indicate those that are often used in combination. The network illustrating pedigree relationships between these cultivars corresponded closely to a second network which illustrated phenotypic similarities (morphology of plants, heads and grains, agronomic characteristics, grain quality and gluten composition). The specific attributes that most closely followed pedigree relationships were identified in this set of wheats. These procedures thus provide a basis for evaluating the role of pedigree in observed associations between phenotypic characteristics.
Genetics of total seed yield and its components in Phalaris aquatica L
Authors: Oram RN
Published: November 2004

Eight plants within each of 55 half-sib families in a diverse breeding population of this perennial pasture grass were assessed for total seed yield in bagged inflorescences, numbers of panicles and spikelets per plant, weight per seed, and for important agronomic characters. Total seed yield was moderately highly heritable (h2N = s.e. = 0.52 � 0.21), and was phenotypically variable. The mean seed yield of the progeny of the highest yielding 10% of the plants should be 44% higher than the mean of the original population. Seed yield was closely correlated genetically with the number of seeds per panicle or per plant, but not with weight per seed or number of panicles per plant. There was little variation for ovule fertility in the population. Visual estimates of spikelet number per plant were very highly correlated genetically with numbers of seeds per plant and total seed yield, but had a non-significant heritability (h2N = 0.30 � 0.20). Scoring for spikelet number per plant before anthesis would enable one generation of mass selection and recombination to be completed each year. Methods for increasing the accuracy of spikelet number estimation are discussed. Provided the true heritability value is greater than a quarter of the heritability of total seed yield, annual cycles of selection on spikelet number score would give a faster rate of genetic advance than direct selection for seed yield on seed parents only each year, or on seed and pollen parents every second year. Seed yields greatly exceeding those of current cultivars should be attainable by recurrent selection. There should be no deleterious correlated responses in flowering time, herbage yield or plant height; mature plant weight and harvest index would increase.
Response of four grain legumes to water stress in south-eastern Queensland. I. Physiological response mechanisms
Authors: Lawn RJ
Published: November 2004

The response of soybean (Glycine max CPI 26671), black gram (Vigna mungo cv. Regur), green gram ( V , radiata cv. Berken) and cowpea (V. unguiculta CPI 28215) to water stress was evaluated in the field at Dalby in south-east Queensland. Three stress response mechanisms were identified in each species but the degree of expression varied substantially. The Vigna spp. cultivars exhibited a measure of escape through faster development in response to stress, particularly in the flowering to maturity phase. Black gram and cowpea revealed additional developmental plasticity in terms of the ability to produce new flushes of flowering when stress was relieved late in the life cycle. Variation in phenology of the soybean cultivar in response to stress was small. Two mechanisms served to avoid dehydration through reduced water loss, viz. (i) stomatal closure in response to falling leaf water potential, and (ii) paraheliotropic leaf movement. Stomatal closure occurred at higher leaf water potentials and the expression of paraheliotropy under stress was strongest in Vigna spp. cultivars. Reduced leaf conductances were associated with higher leaf temperatures, particularly in soybean where paraheliotropy under stress was small. The inter-relationships between stress mechanisms, and some implications of cultivar differences for acclimatization to drought, are discussed.
Parotid saliva of sheep. 1. Effects of level of intake and type of roughage
Authors: Doyle PT , Egan JK , Thalen AJ
Published: November 2004

In three experiments, quantitative collections of saliva were made from the right parotid duct of six Merino wethers. Experiment 1 assessed the repeatability of the collection techniques and found little difference in salivary parameters measured at intervals over a 6-week period. When chopped lucerne was given at three levels (experiment 2) the secretion rate of parotid saliva (g 19.5h-1) increased (P < 0.01) with increasing lucerne consumption as did the concentrations and amounts of total and urea nitrogen in saliva (P < 0.05 to P< 0.01). Only minor changes in the secretion of total and reducible sulfur occurred. Plasma urea nitrogen (P < 0.05) and blood sulfate sulfur (P < 0.01) concentrations increased with increasing lucerne consumption. Values are given to indicate the variability between sheep in volume and composition of parotid saliva secretions. In experiment 3 the sheep were offered four different roughage diets. The secretion rate of saliva (g 19.5h-1) increased (P < 0.01) when more fibrous roughages were given. The type of roughage also affected (P < 0.01) the concentrations and amounts of total and urea nitrogen in saliva, but there was little effect upon the secretion of total or reducible sulfur. Plasma urea nitrogen and blood sulfate sulfur concentrations were different (P < 0.01) on the various roughage diets. The results are compared with the findings of previous research, and estimates of the amounts of nitrogen and sulfur recycled to the rumen in saliva are made.
Tillage and growth of a wheat crop in a loamy sand
Authors: Hamblin AP , Tennant D , Cochrane H
Published: November 2004

In the fourth consecutive year of a long-term tillage trial in a loamy sand in Western Australia above- and below-ground growth of a wheat crop (cv. Gamenya) was monitored. The grain yield was nearly 20% greater in the crop sown after ploughing than in those crops sown by direct drilling. A similar trend had been noted in each preceding year. Cumulative water use was 15 and 9 mm less with zero and minimum tillage than with ploughing. The ploughed treatment had lower soil strengths, not only in the seedbed but also to 50 cm in the subsoil, until 8 weeks after seeding. These lower soil strengths coincided with more-rapid wetting of the subsoil under ploughing, and faster root extension rates. Dry matter production was significantly greater in the ploughed crop from the initial sampling date, and direct-drilled crops were not able to compensate in the later part of the season, despite using slightly more water during that period. The slower wetting of the profile under direct drilling was a persistent feature over several seasons in this soil type. It was considered responsible for the increased soil strength and slower root extension rates. The implications of direct-drilled sandy soils for crop productivity, and drainage control of recharge soils in saline catchments, are discussed.
Effects of residues of crop plants on germination and early growth of wheat
Authors: Lovett JV , Jessop RS
Published: November 2004

In experiments conducted under controlled and field conditions residues of a range of crop plants were found to affect germination, emergence, height of the coleoptile and length of the longest seminal root of wheat. Rape and some leguminous crops exerted the greatest phytotoxic effects. Phytotoxicity was increased when crop residues were incorporated into soil rather than being left on the surface. The phytotoxins did not kill the test species, but it is argued that their effects would disadvantage such a species under field conditions and that instances of such effects are likely to increase as the practices of minimal tillage and stubble retention become more widely adopted.
Enzymic diagnosis of copper deficiency in subterranean clover. II. A simple field test
Authors: Delhaize E , Loneragan JF , Webb J
Published: November 2004

A rapid, simple and robust field test is described for diagnosing copper deficiency in subterranean clover plants by measuring ascorbate oxidase activity in young folded leaf blades (YFL) homogenized in phosphate buffer. The test measures activity by counting the drops of iodine required to titrate, to a dark blue end-point, excess ascorbic acid added to and incubated for 20 min with a YFL homogenate. When reagent control titrations had titres of 11 drops of iodine, YFL homogenates from copper-adequate plants had titres of 2-3 drops, from copper-deficient plants 6-11, and from plants with marginal copper supply 4-5 drops. The test was standardized against the measurement of ascorbate oxidase activity in YFL by oxygen uptake. Ascorbate oxidase activity was remarkably insensitive to assay temperature, decreasing by only one-third with decreasing temperature from 30 to 10�C. It was also very stable in both homogenates and whole leaves. At room temperature, activity dropped by only 25% in homogenates after 6 h and in whole leaf blades after 48 h. When stored in ice, leaf blades retained full activity for at least 5 days. Diagnosis of copper deficiency by the new test agreed closely with diagnosis based on copper analysis of young open leaves taken from the same subterranean clover plants in field pastures. The test should allow extension workers to give on-the-spot advice about the copper status of pastures containing subterranean clover.
Zinc in subterranean clover (Trifolium subterraneum L. cv. Seaton Park). I. Effects of zinc supply on distribution of zinc and dry weight among plant parts
Authors: Reuter DJ , Loneragan JF , Robson AD , Plaskett D
Published: November 2004

Effects of zinc supply on the distribution of zinc and dry weight among plant parts were examined during the first 55 days of vegetative development of Seaton Park subterranean clover grown in a zinc-deficient soil in a glasshouse. Symptoms of zinc deficiency first appeared in young trifoliate leaves. Zinc deficiency decreased the expansion of blades and petioles, delayed the development of leaves and lateral branches, depressed dry weights of roots and shoots, and increased the proportion of plant dry weight in roots and leaf blades. In each treatment and at each harvest, zinc concentrations varied widely amongst plant parts and with their physiological age. Plant parts also differed widely in the response of their dry matter and zinc concentrations to both zinc treatment and harvest time. It is suggested that these complex relationships explain why plant samples consisting of composite plant parts are not suitable for diagnosis of zinc deficiency. In the present experiment, zinc concentration in whole shoots was unsatisfactory for diagnosing zinc deficiency since concentrations were higher in young, zinc-deficient plants than in older, zinc-adequate plants. In young leaf blades of the same physiological age, zinc concentrations showed reasonably constant relationships with plant growth throughout the entire experiment. However, they varied two- to three-fold in leaves of different ages from the same plants. The results show the importance for diagnosis of zinc deficiency of selecting as a sample a single organ of defined physiological age. The youngest open leaf blade is recommended for diagnosis of zinc deficiency in subterranean clover.
Toxicity of Leucaena leucocephala in ruminants: the effect of supplemental thyroxine on goats fed on a sole diet of Leucaena
Authors: Megarrity RG , Jones RJ
Published: November 2004

Daily injections of thyroxine were ineffective in overcoming the toxic effects of feeding Leucaena to goats. The treated goats did not differ from the controls in liveweight change or body condition over the 15 weeks of feeding Leucaena and both groups of animals developed oesophageal lesions. Treated animals maintained normal serum thyroxine (T4) and triiodothyronine (T3) levels and did not exhibit the thyroid hyperplasia of the controls. An increase in the serum T4 and T3 levels of three of the control animals after 5 weeks of feeding was associated with declining mimosine concentration in the feed and the ability of the hyperplastic thyroids to produce sufficient T4. Serum analyses suggested zinc deficiency in the control animals, associated with their low thyroid status. It was concluded that the goitrogenicity of 3-hydroxy-4(1H)-pyridone (DHP) is only partly responsible for the toxicity of Leucaena to ruminants, and that the low feed intakes and low liveweight gains are related to other effects of DHP. The evidence for extra-ruminal metabolism of DHP is discussed.
Physiology of growth and seed production in Lupinus angustifolius L. II. Effect of temperature before and after flowering
Authors: Downes RW , Gladstones JS
Published: November 2004

Plants of Lupinus angustifolius cv. Unicrop, with branches excised to eliminate competition between branches and the primary inflorescence, were raised at 21/16�C and transferred as flowering began to eight temperature regimes from 36/31 to 15/10�C for seed development. Vegetative growth rather than seed growth was stimulated by coolest conditions, although ultimate individual seed weight was greatest at the lowest temperatures. Plant growth was poor at temperatures above 27/22�C. Temperatures about 21/16�C were most suitable for seed development. In another experiment, plants with branches excised were grown at 27/22 or 18/13�C until flowering, when they were either retained in the same conditions or moved to the other. Conditions before flowering determined growth of the inflorescence for the first 24 days after flowering began, but conditions after flowering affected ultimate yield. Plants raised to flowering at 27/22�C were able to recover if exposed to 18/13�C after flowering. This suggested a possible role for lupins as an autumn crop where water is available.
Effects of temperature on germination, emergence and early seedling growth of swards of Mt Barker subterranean clover plants grown with and without nitrate
Authors: Silsbury JH , Zuill D , Brown PH
Published: November 2004

Effects of constant temperatures of 10, 15, 20, 25 and 30�C on the germination, emergence and early vegetative growth of Trifolium subterraneum L. cv. Mt Barker grown as swards were examined in temperature-controlled glasshouses and in a growth cabinet. Seedlings were established at a density of about 2000 plants m-2 and grown for up to 70 days. Plants were either inoculated and grown without mineral nitrogen (-N), or supplied with 7.5 mM NO-3 (+ N). Percentage germination and emergence were hardly affected by temperatures of 10-20�C, but at 25�C were reduced to 50%, and at 30�C to about 10%. The rates of germination and emergence were slowest at 10�C, but showed little change with temperature over the range 15-30�C. Time to closed canopy (leaf area index 3) and time to a dry weight of 133 g m-2 were shorter where plants were supplied with NO; than where mineral nitrogen was withheld and a symbiotic system established. Rates of N2-fixation, as measured by acetylene reduction assay, were not markedly affected by temperature over the range 10-25�C. Relative efficiency ranged from about 0.55 at 10, 15, and 20�C to about 0.66 at 25�C. At 30�C nodulation still occurred, but nitrogenase activity was very slight. It is concluded that, where swards of subterranean clover are grown in the absence of any mineral N, a period of N-starvation limits growth during the time taken for symbiotic N2-fixation to become established. Such retardation of growth is small at about 20�C, but becomes more marked at lower and higher temperatures. The establishment of subterranean clover swards in soils of low N status are likely to be retarded following an early (March) or a late (July) start in the growing season. In such cases a 'starter' application of mineral nitrogen may promote the early growth of the legume.
Furrow irrigation of grain sorghum in a tropical environment. II. Influence of period of inundation on the utilization of soil and fertilizer nitrogen by the crop
Authors: Wright GC
Published: November 2004

Grain sorghum was grown in plots that had been fertilized, before sowing, with either 0, 80 or 170 kg Ha-1 nitrogen (N), and furrow irrigated for periods of 0 (sprinkler irrigated control), 3, 6, 12 or 24 h. The apparent uptake of fertilizer nitrogen declined from 63 to 7% as the period of inundation increased from 0 to 24 h. Large quantities of nitrate (up to 82 kg N ha-1) remained in the surface soil layers of all furrow irrigated ridges at crop maturity, in contrast to the sprinkler irrigated ridges (up to 4 kg N ha-1). At all inundation periods a constant proportion of the applied nitrogen was moved to the ridge tops, where it was unavailable for plant uptake. The differences in the recovery of applied nitrogen between the crops given 0 (sprinkler) and 3 h irrigation was mainly attributed to the surface accumulation of nitrate in the latter. Further reduction of nitrogen uptake with longer periods of inundation are attributed to differential rates of loss of nitrogen from the soil by denitrification and leaching.
Effect of nutrient seed coating on the emergence and early growth of perennial ryegrass
Authors: Scott JM , Mitchell CJ , Blair GJ
Published: November 2004

Perennial ryegrass (Lolium perenne L.) seeds were coated with either lime, reverted superphosphate plus nitrogen as isobutylidene diurea (RSN), or partially acidulated rock phosphate plus sulfur (ESPARP). In one experiment emergence rates and total emergence were calculated by fitting Mitscherlich-type curves to the data and then conducting statistical tests on the three parameters found for each curve. There was a significant interaction between soil moisture and coating treatment for all three parameters. In a glasshouse experiment, the same coated and uncoated seed treatments were sown either in soil supplied with nitrogen, phosphorus and sulfur or in soil with nutrient deficiencies of either N, P, or S or NPS, and the early growth of the plants and their P and N uptakes were studied. The two nutrient-coated treatments (RSN and ESPARP) produced more tillers and dry matter yields of roots and shoots than did lime-coated or uncoated seed when grown in soils deficient in P, S or NPS. Nitrogen deficiency reduced yields of all plants, even those derived from RSN seeds. N uptake in the RSN treatment was not significantly different from the ESPARP treatment, indicating that the N in isobutylidene diurea was not available to the plant.
Genetic control of flowering time in subterranean clover
Authors: Tan BH
Published: November 2004

The quantitative inheritance of flowering time in autumn-sown subterranean clover (Trifolium subterraneum L. ssp. subterraneum) was studied in a 13 x 13 diallel cross in a Mediterranean-type environment. Flowering time was shown to be highly heritable with a low average degree of dominance, which was predominantly in the direction of earliness. Covariance/variance ( Wr/Vr) regression analysis indicated early flowering to be conditioned mostly by dominant alleles, and lateness mostly by recessives. The alleles were slightly asymmetrically distributed among the parents, with recessives marginally in excess. Inadequacy of the additive-dominance model, on which the Birmingham diallel analysis is based, was detected by a significant departure from unity of the joint regression coefficient and the heterogeneity among arrays of (Wr Vr) values, which could be ascribed to and overcome by omitting two late-flowering parents from the diallel cross.
Germination and growth of Secale montanum Guss. in the presence of sodium chloride
Authors: Noble CL
Published: November 2004

The salt tolerance of Secale montanum varied at different growth stages. Tolerance during germination was high, with NaCl of more than 340 mol m-3 necessary to reduce germination by 50%. Seedling emergence was more sensitive to NaCl with a 50% reduction occurring at approximately 300 mol m-3. Up to 200 mol m-3aC1, all emerged seedlings reached the first leaf stage, although shoot dry weight of emerged seedlings at 200 mol m-3 NaCl was reduced to 64% of that of seedlings under non-saline conditions. During later plant growth, shoot growth (dry weight) had a salt tolerance threshold of 20 mol m-3 NaCl (electrical conductivity, ECw, of 2.7 mS cm-1). Subsequent yield decline up to approximately 100 mol m-3 NaCl (ECw, = 10.8 mS cm-1) was 6.7% of non-saline yield per mS cm-1 increase in ECw. At higher NaCl concentrations a more reciprocal form of yield decline occurred. Considerable plantto- plant variation for shoot dry weight existed in the presence of NaCl, indicating scope for selection to increase the tolerance of S. montanum. Osmotic adjustment was aided by a reduction in tissue water content under increasing NaCl and by the accumulation of sodium and chloride. Sodium was mainly accumulated in the roots, although the roots increased their selectivity for potassium over sodium. Chloride was mainly accumulated in the shoots. S. montanum could be classed as moderately salt tolerant, a tolerance similar to such pasture grasses as Lolium perenne, Phalaris aquatica and Festuca arundinacea.