bluuebunny/crossref_metadata_2025 huggingface dataset:
Late Quaternary Spatio-temporal Limnological Variations in the Altiplano of Bolivia and Peru
Authors: Wirrmann Denis , Mourguiart Philippe
Published: September 2002

Between the western and eastern Andean cordilleras in Peru and Bolivia, there are three main lacustrine basins: Lake Titicaca, Lake Poopó, and the group of Coipasa-Uyuni. For the past few millennia, highly variable environmental conditions have been recorded in their sediments. Today a latitudinal meteorological gradient influences the lakes' status, leading to specific deposits and ostracod communities. Lake Titicaca in the north is oligohaline, whereas Lake Poopó further south is polyhaline. In the south, the Coipasa-Uyuni depression is characterized by a 12,000-km2surficial salt crust. During the Late Pleistocene (ca. 40,000 to 25,000 yr B.P.), the water depth and salinity in paleolake Poopó fluctuated widely and paleolake Titicaca was slightly larger than at present. Sedimentation was mostly biocarbonate in the shallower areas and it was detrital-organic in the deepest zones. During the Holocene, a dry period transformed Lake Poopó into a "salar" with evaporite precipitation. Lake Titicaca registered a large decline in water level (8100-3600 yr B.P.) initially inducing gypsum precipitation followed by short influxes of water, with an ostracod faunal composition similar to that of the modern brines of Lake Poopó. Lake Titicacas' present condition only appeared between 2200 and 1500 yr B.P.
A Younger Dryas Icecap in the Equatorial Andes
Authors: Clapperton Chalmers M. , Hall Minard , Mothes Patricia , Hole Malcolm J. , Still John W. , Helmens Karin F. , Kuhry Peter , Gemmell Alastair M.D.
Published: September 2002

Morphologic and stratigraphic evidence shows that a late-glacial ice cap existed on part of the Eastern Cordillera of Ecuador (Lat. 0° 20′ S) on ground with a mean elevation of 4200 m where none exists now. An outlet glacier from an ca. 800 km2ice cap terminated at 3850 m altitude in the Papallacta valley on the eastern side of the plateau. Radiocarbon dates show that moraines formed by this advance were ice-free by 13,20014C yr B.P. Tephras and the age of organic deposits at the plateau edge indicate ice-free conditions before 11,80014C yr B.P. This interval was followed by the expansion of an ca. 140 km2ice cap that discharged glaciers into adjacent valleys where terminal moraines were built at 3950 m altitude. AMS and conventional radiocarbon dates from macrofossils, peat, and gyttja above and below till of the readvance indicate that the ice cap formed between ca. 11,000 and 10,00014C yr B.P. and was thus coeval with the European Younger Dryas event. The ice cap developed in response to a surface temperature cooling of at least 3°C in the tropical Andes, a finding that is consistent with a coupled equatorial/high latitude North Atlantic climate system operating at the late-glacial/Holocene transition. These results are further evidence that Younger Dryas cooling may have been a global event.
A Detailed 31,000-Year Record of Climate and Vegetation Change, from the Isotope Geochemistry of Two New Zealand Speleothems
Authors: Hellstrom John , McCulloch Malcolm , Stone John
Published: September 2002

Uranium-series dating and stable isotope analyses of two speleothems from northwest Nelson, New Zealand, record changes in regional climate and local forest extent over the past 31,000 years. Oxygen isotope variation in these speleothems primarily represents changes in the meteoric waters falling above the caves, possibly responding to latitudinal changes in the position of the Subtropical Front in the Tasman Sea. Seven positive excursions can be identified in the oxygen isotope record, which coincide with periods of glacier advance, known to be sensitive to northward movement of the Subtropical Front. Four glacier advances occurred during oxygen isotope stage 2, with the most extreme glacial conditions centered on 19,000 cal yr B.P. An excursion in the oxygen isotope record from 13,800 to 11,700 cal yr B.P. provides support for a previously identified New Zealand glacier advance at the time of the Younger Dryas Stade, but suggests it began slightly before the Younger Dryas as recorded in Greenland ice cores. Carbon isotope variations in the speleothems record changes in forest productivity, closely matching existing paleovegetation records. On the basis of vegetation changes, stage 2 glacial climate conditions terminated abruptly in central New Zealand, from 15,700 to 14,200 cal yr B.P. Evidence of continuous speleothem growth at one site suggests that depression of the local treeline was limited to 600–700 m below its present altitude, throughout the last 31,000 years.
Analysis of the effects of chitosan on inflammation, angiogenesis, fibroplasia, and collagen deposition in polyvinyl alcohol sponge implants in rat wounds
Authors: Diegelmann Robert F. , Dunn James D. , Lindblad William J. , Cohen I. Kelman
Published: September 2002

Chitosan is a large molecular weight, positively charged polysaccharide extracted and purified from the chitin of crab shells. This compound has been shown to have hemostatic activity and has been suggested for use as a topical agent in tissue repair. The objective of this study was to analyze the effect of chitosan on the wound healing response to a standardized injury in the rat. The polyvinyl alcohol sponge implant model was used as a means to deliver either chitosan or its vehicle to a standardized subcutaneous wound on the backs of Sprague‐Dawley rats. On days 8 and 14, the chitosan‐treated implants contained primarily polymorphonuclear leukocytes compared with the vehicle controls which contained mainly macrophages, fibroblasts, collagen, and new blood vessels. High‐performance liquid chromatography analysis for hydroxy‐l‐proline deposited in the sponge implants showed significantly lower amounts on both days 8 and 14 in the chitosan treatment group. These histologic and biochemical studies suggest that chitosan modulates wound healing by first reducing the influx of activated tissue macrophages, which in turn reduces the subsequent events of angiogenesis, fibroplasia, and connective tissue deposition.
Anomalous luminescence in Sr4Al14O25:Eu, Dy phosphors
Authors: Lin Yuanhua , Tang Zilong , Zhang Zhongtai , Nan Ce Wen
Published: September 2002

Sr 4 Al 14 O 25 : Eu , Dy material with an extraordinarily long afterglow was synthesized via a traditional ceramic processing. Such a long afterglow observed can last over 20 h at recognizable intensity level (0.32 mcd/m2), which is attributed to energy exchange between the traps and emission states resulting from Dy and Eu doping. When the Eu2+ concentration doped in the host is less than 1.2 mol %, the emission spectra of Sr4Al14O25:Eu, Dy show two main peaks at 407 and 494 nm, ascribed to two types of Eu2+ centers existing in the Sr4Al14O25 host. The emission peak at 407 nm disappears slowly with increasing concentration of Eu2+ due to the energy exchange between two types of Eu2+ centers.
Approach for the fabrication of MgB2 superconducting tape with large in-field transport critical current density
Authors: Komori K. , Kawagishi K. , Takano Y. , Fujii H. , Arisawa S. , Kumakura H. , Fukutomi M. , Togano K.
Published: September 2002

The letter reports the fabrication of MgB2 superconducting tape using a flexible metallic substrate as well as its strong pinning force, which was verified by direct measurement of transport critical current density. The tape was prepared by depositing MgB2 film on a Hastelloy tape buffered with an yttria-stabilized-zirconia layer. The Jc of the tape exceeds 105 A/cm2 at 4.2 K and 10 T, which is considered as a common benchmark for magnet application. The Jc dependence on magnetic field remains surprisingly very small up to 10 T, suggesting that the tape has much better magnetic field characteristic than conventional Nb–Ti wires in liquid helium.
The role of trees in enhancing soil nutrient availability for native perennial grasses in open eucalypt woodlands of north-east Queensland
Authors: Jackson J. , Ash A. J.
Published: September 2002

To investigate the effects of eucalypt trees on pasture in open eucalypt
woodlands of north-eastern Queensland, 2 common native pasture species,
Chrysopogon fallaxand
Heteropogon contortus, were grown in soil collected from
under tree canopies and inter-canopy areas. These soils were collected from 2
localities that differed in soil fertility. The objective was to determine
whether trees enhanced soil nutrient levels beneath their canopies and whether
such changes affected pasture productivity and quality. It was hypothesised
that tree effects would be greater when overall soil fertility was low. Shade
and water stress treatments, which aimed to simulate field conditions, were
also imposed to investigate their independent and interactive effects on plant
growth.
Chemical analyses showed that nutrient levels were higher in under-canopy
soils, and plants grown in under-canopy soil produced 42% more biomass
than plants in outside-canopy soil. This increase in biomass was significantly
greater when the soil was from the low fertility site than from the high
fertility site. Leaf quality, in terms of N and P concentration and dry matter
digestibility (DMD), was generally higher in plants in under-canopy soil.
Shading reduced plant root biomass but had no effects on above ground biomass
or leaf quality. Water stress reduced above and below ground biomass and
increased leaf quality. Shading and water stress effects were greater in
plants in the more fertile soil types. Simulated ‘under-canopy’
plants (shaded, water-stressed plants in under-canopy soil) produced more
biomass and had higher leaf N concentration and DMD than simulated
‘outside-canopy’ plants (unshaded, well-watered plants in
outside-canopy soil).
In a pastoral context, trees in tropical woodlands are generally considered in
terms of their competitive effect on pasture productivity. This study has
demonstrated that soil nutrient availability is enhanced under eucalypt
canopies. The biomass results indicate that this effect is greater when
overall soil fertility conditions are low. These enhanced soil nutrient
conditions influence forage productivity and quality. Such positive benefits
should be considered when management decisions are taken to remove or kill
trees in eucalypt woodlands.
Restricted branching narrow-leafed lupin. I. Population density
Authors: Dracup Miles , Galwey Nick , Thomson Bob
Published: September 2002

Narrow-leafed lupin is a major grain crop in southern Australia. Its freely
branching growth habit is often seen as a limitation to grain yield, so
genotypes with restricted branching are being investigated. Since agronomic
recommendations for lupins have been developed with conventional, normal
branching cultivars, agronomy, particularly population density, may need
adjustment for restricted branching types. Here we report a study of
population density requirements of 3 restricted branching genotypes that cover
the range of variation available in degree of branching restriction, and a
normal branching cultivar, Merrit, which is widely grown and has good general
adaptation. The experiments were performed during 3 growing seasons at a
number of sites throughout Western Australia. Data were analysed using
recently developed statistical techniques, including spatial analysis to
reduce error variation and a smoothing spline to minimise assumptions made
about the form of the response to density. Generally, responsiveness to
density was similar for all genotypes, as were optimal densities, which, with
only one exception, were achieved at 35–57 plants/m
2 . At higher densities there were fewer pods per plant
and seeds per pod but heavier seeds; these effects were similar for all
genotypes except in the case of pods per plant, which was reduced more by high
density in the restricted branching types. Apart from yield, other advantages
of high density were taller plants, larger grain, and slightly higher grain
protein concentration.
Yields were highly correlated with shoot dry mass, but not with harvest index.
Shoot dry mass tended to be lower in restricted branching genotypes, but
harvest indices were similar. However, for yield, shoot mass, and especially
harvest index, interactions between genotype and environment were generally
highly significant. These results indicate that the restricted branching
genotypes currently available do not have wide suitability, but in
environments where harvest index in normal branching lupins is poor or
unstable and yield is not as strongly limited by growth, they could provide
higher or more stable yields. Further work is required to identify
‘niche’ environments.
Grain from restricted branching genotypes was generally less variable in size
and had higher concentrations of P, K, S, Mg, and Mn, whereas some genotypes
also had higher Ca, Cu, Na, and protein. Some of these changes in grain
quality might be related to grain filling earlier in the season, under less
stressful conditions and with less competition from concurrent vegetative
growth than in normal branching genotypes.
Intake and long-term cysteine supplementation change wool characteristics of Romney sheep
Authors: Sherlock R. G. , Harris P. M. , Lee J. , Wickham G. A. , Woods J. L. , McCutcheon S. N.
Published: September 2002

Sulfur amino acid supplementation increases wool production in sheep at low
planes of nutrition but it is unclear whether there is any benefit of
supplementation at planes of nutrition above maintenance and what implications
this might have for wool quality characteristics. This experiment directly
investigated the interaction between sulfur supplementation and plane of
nutrition in terms of wool growth and fibre characteristics. Twenty-four
Romney ewes, acclimatised in individual metabolism units over a 7-week
pre-treatment period, were allocated to 1 of 4 treatment groups based on a 22
factorial arrangement. Groups were low (L) or high (H) intake (0.8 or 1.3
maintenance, respectively) with continuous intravenous infusion of either
saline (–Cys) or cysteine (+Cys, 2 g/day). During the 3-month
treatment period, measurements were obtained for liveweight, plasma cysteine
concentration, wool sulfur concentration and output, clean wool growth, mean
fibre diameter (MFD), length growth rate (LGR), colour, loose wool bulk,
handle, and crimp frequency and character. Clean wool growth response
(P < 0.05) to cysteine supplementation was greater
for the L sheep (6.06 v. 4.31 g/100
cm2) than the H sheep (7.20 v.
6.13 g/100 cm2). The response to supplementation in
LGR (P < 0.01) was similar in both H (14%) and
L (20%) sheep. There was no response in MFD due to sulfur
supplementation, although fibre diameter measurements made along the fibres
suggest that there was a response in L but not H sheep
(P < 0.1).
Wool sulfur concentration and output increased as a result of cysteine
supplementation but concentration increased more in L (30.6
v. 24.5 mg S/g; P < 0.01)
than in H sheep (28.4 v. 26.2 mg S/g). Qualitative
electrophoresis analyses suggested that the increase in wool sulfur was
achieved primarily by an increase in ultra-high-sulfur proteins. Crimp
frequency and character were both significantly (P <
0.01) enhanced by cysteine supplementation.
It is concluded that cysteine supplementation, at feed intakes that commonly
occur in the commercial situation, can produce a useful increase in wool
growth. This growth increase is primarily accomplished by increasing length
growth rate rather than fibre diameter, which should also improve the value of
the wool fibre produced.
A review of the welfare issues for sows and piglets in relation to housing
Authors: Barnett J. L. , Hemsworth P. H. , Cronin G. M. , Jongman E. C. , Hutson G. D.
Published: September 2002

This review of sow welfare addresses all aspects of housing for adult female
pigs, including the issue of piglet welfare during lactation. It puts the
issue of sow welfare in perspective by briefly outlining different approaches
to the scientific assessment of welfare, the ‘feelings, preference,
nature, and the functional or homeostasis’ approaches. We believe the
last approach currently offers science the best assessment of welfare and is
the approach that is utilised in this review. It involves comparing housing or
husbandry systems and risks to welfare on the basis of relative changes in
biological (behavioural and physiological) responses and corresponding
decreases in fitness (growth rate, reproductive performance, or
health/injury/immunology).
The review discusses the following areas: (i) housing of
individually housed pregnant pigs, with subsections on tethers, stalls,
reproductive performance, exercise, and new stall designs; conventional,
alternative, and outdoor group housing with subsections on aggression,
electronic feeding stations, ecoshelters, and other alternative group housing
designs; and other issues, such as lameness, culling, straw and other
substrates, diet and hunger, quality of stockpeople, and housing around mating
including oestrus detection and mating; and (ii)
farrowing and lactating pigs with subsections on farrowing crates and
alternative farrowing systems, stress around farrowing and during lactation,
maternal behaviour and piglet survival, and sow and piglet injury and
lameness.
Conclusions and recommendations arising from the review include the need for
public education to provide an informed consumer base that will result in some
consensus on welfare issues among diverse interest groups and the need for
industry education that results in better animal welfare and a sustainable
industry. Some specific research recommendations include space allowance and
the duration of housing for individually housed pigs, welfare issues of
breeding sows in ecoshelters, piglet mortality in alternative systems,
aggression in conventional and large groups, bedding, and hunger.
Comparison of rumen fluid from South African game species and from sheep to digest tanniniferous browse
Authors: Jones R. J. , Meyer J. H. F. , Bechaz F. M. , Stoltz M. A. , Palmer B. , van der Merwe G.
Published: September 2002

The hypothesis that South African game animals that use browse containing
condensed tannins (CT) could have rumen microbial populations better able to
ferment tanniniferous forages was explored. Rumen fluid (RF) from a range of
browsing ruminants was used to ferment tanniniferous forages
in vitro and the results were compared with the values
obtained with rumen fluid from sheep. Leaves of the shrub legumes
Leucaena leucocephala, L. pallida,
L. trichandra,
Calliandra calothyrsus,Gliricidia sepium,
and Acacia boliviana were used as substrates.
In vitro digestibility of dry matter (IVDMD) and
nitrogen (IVND) was measured in the presence or absence of polyethylene glycol
(PEG) 4000 to assess the adverse effects of the CT in the feeds. Rumen fluid
from giraffe, greater kudu, eland, duiker, impala, nyala, goat, and gnu was
compared with that from sheep. Ability to metabolise or block the adverse
effects of CT was expected to result in only a small or no response to PEG in
terms of IVDMD and IVND with rumen fluid from browsers, and therefore to
result in a significant animal feed and animal PEG interaction.
There were no significant (P > 0.05) animal feed
interactions. For every animal species there was a response to PEG in terms of
IVND, and this response was linearly related to the CT in the feed as measured
by PEG binding using 14C-labelled PEG.
Rumen fluid from browsers had a lower pH (5.78 0.060 v.
6.68 0.052) and a higher dry matter content (1473 102 mg v. 415 4.3 mg/100
mL RF) than that of grazers (sheep and gnu). However, when measured at 2 pH
levels (6.7 and 5.8), IVDMD and IVND of the feeds were not improved at the
lower pH with rumen fluid from the browsers. Rather, digestibility was
depressed at the lower pH with rumen fluid from all animal species.
We conclude from these in vitro studies that rumen
microbial populations from browsers are not able to ferment tanniniferous
forages better than rumen microbial populations from grazers. It seems likely
that these browsers do not have rumen bacteria capable of degrading the CT in
these shrub legumes. Production on such tanniniferous feeds may well depend on
tannin binding with proline-rich saliva rather than on metabolism of or
tolerance to CT by rumen bacteria.
The impact of nutrition on bovine muscle glycogen metabolism following exercise
Authors: Gardner G. E. , McIntyre B. L. , Tudor G. D. , Pethick D. W.
Published: September 2002

The aims of this study were to develop a muscle biopsy technique which imposed
minimal stress on cattle, enabling accurate monitoring of muscle glycogen
concentration; to develop a method based on exercise, for controlled depletion
of glycogen from muscle; and to utilise the model to determine the ability of
cattle on hay and cereal grain diets to replete muscle glycogen. Expt 1
established the influence of repetitive muscle biopsies on muscle glycogen
concentration. It consisted of 3 trials in which cattle received 4 serial
biopsies every 36 h over a 108-h period. Repetitive biopsy had minimal impact
on M. semimembranosus (SM) glycogen concentrations,
although it did reduce concentration in the
M. semitendinosus (ST), particularly when animals were
penned individually. Expt 2 established an exercise regimen in which cattle
were trotted at 9 km/h for five 15-min intervals, with 15 min rest between
each interval, depleting muscle glycogen by approximately 50%. Expt 3
determined the repletion rates of muscle glycogen, by utilising the
exercise/biopsy model. Cattle were allocated to 4 dietary treatments: hay,
silage, hay–barley, and hay–maize. The metabolisable energy (ME)
of these rations ranged from 8 to 11.3 MJ/kg. After the exercise regimen,
glycogen concentration repleted in a linear fashion over 72 h in the SM of the
animals fed maize, barley, and silage. In contrast, the ST of these animals
was refractory to glycogen repletion over the same period. Both the SM and ST
of the cattle on the hay diet showed no significant repletion following
exercise. Repletion following exercise demonstrated a positive linear
relationship with ME intake.
Effects of sowing time and nitrogen fertiliser on canola and wheat, and nitrogen fertiliser on Indian mustard. I. Dry matter production, grain yield, and yield components
Authors: Hocking P. J. , Stapper M.
Published: September 2002

Canola, Indian mustard, and wheat were grown under dryland conditions at Ariah
Park and Cowra (canola only) in the cropping belt of New South Wales,
Australia, to determine the effects of sowing time (canola and wheat) and
nitrogen (N) fertiliser on the growth, grain yield, and yield components of
the crops. Compared with an April sowing, the grain yield of canola at Ariah
Park was reduced by 35% for a May sowing and by 67% for a July
sowing. Canola yield at Cowra was reduced by 45% between early and late
May sowings. Wheat yield declined by 35% between the May and July
sowings at Ariah Park. Grain yields of canola and wheat at Ariah Park
responded to N fertiliser in the April and May sowings, but not in the July
sowing. Indian mustard had a higher yield than thecomparable sowing of canola.
Canola yields at Cowra were more responsive to N fertiliser than at Ariah
Park, and increased from 0.5 to 2.9 t/ha with 100 kg N/ha. For each
day that sowing canola was delayed at both sites after Aprill—early
May, anthesis was delayed on average by 0.52 days. For Dollarbird wheat, the
delay in anthesis was 0.39 days per day sowing was delayed. Dry matter
accumulation by the oilseeds was greatest during flowering, but before
anthesis for wheat. Late sowing had little effect on the proportions of dry
matter accumulated in a particular growth period. Irrespective of sowing time,
grain yields and dry-matter harvest indices of the oilseeds were similar to
values for wheat when differences in the biosynthetic costs of grain and straw
production were taken into account. Late sowing usually resulted in a greater
reduction in canola oil concentration than high N fertiliser rates. Canola oil
concentration was reduced by 1.7 percentage points per 1mp;deg;C increase in
mean temperature during grain filling as a result of sowing late. It was
concluded that N fertiliser could not compensate for the yield reduction in
canola and wheat due to sowing late. Early sowing was essential to achieve
high oil levels in canola.
The production and storage of a fermentor-grown bacterial culture containing Synergistes jonesii, for protecting cattle against mimosine and 3-hydroxy-4(1H)-pyridone toxicity from feeding on Leucaena leucocephala
Authors: Klieve A. V. , Ouwerkerk D. , Turner A. , Roberton R.
Published: September 2002

The leguminous shrub Leucaena leucocephala (leucaena) iswidely used as a forage species for cattle in tropical agriculture. However,leucaena contains the toxic amino acid mimosine. Both mimosine and its primaryruminal degradation product 3-hydroxy-4(1H)-pyridone (DHP) are toxic and theiraccumulation in the animal’s system results in hair loss, reducedliveweight gain, and goitre. The ruminal bacteriumngle cultivar bywithholding water. In Expt 2, plants of EP and MK were grown together in thesame container and received water daily with gradation in intensity of waterdeficit achieved by varying the daily water ration per container.All cultivars in each experiment exhibited commonly reported responses towater deficit, characterised by diminished evaporative surface area andincreased root : shoot ratio. The response of MK was primarily morphologicaland MK plants had smaller plant size, higher root : shoot ratio,
Nutrition during mid to late pregnancy does not affect the birthweight response to mid pregnancy shearing
Authors: Kenyon P. R. , Morris S. T. , Revell D. K. , McCutcheon S. N.
Published: September 2002

This study was designed to determine whether dam nutrition during mid to latepregnancy influences birthweight responses from pregnancy shearing.Romney-cross ewes were either shorn during mid pregnancy(n = 68) or left unshorn (n= 66). Ewes were offered either a maintenance level of feed (a level ofnutrition that enabled the dam to maintain conceptus-free liveweight) or aed to apparenthomogeneity by using various biochemical fractionation procedures, such assolubilization with Triton X-100, sephadex gel filtration chromatography,concanavalin A–sepharose affinity chromatography anddiethylaminoethyl–cellulose ion-exchange chromatography. The isolatedPPase has a molecular mass of approximately 36 kDa and an isoelectric point of5.95. Sperm surface topography of the enzyme was investigated usingfluorescein isothiocyanate-conjugated antibody of the purified PPase. Theimmunofluorescent studies have demonstrated that the isolated PPase islocalized on the external surface of viable sperm. Immunocytochemical studiesalso revealed a marked topographical alteration of ecto-PPase duringepididymal transit of the male gametes. Immunoreactivity was observed all overthe surface of caput sperm, but was restricted primarily to the anterior tipof the head in the corpus sperm and to the posterior part of the head in caudasperm cells. The maturation-dependent decrease in PPase activity was alsoconfi
Nitrogen fixation characteristics of Rhizobium surviving in soils 'equilibrated' with sewage biosolids
Authors: Munn Kellie J. , Evans Jeffrey , Chalk Phillip M.
Published: September 2002

To determine the effects of urban sewage biosolids on the symbiotic
effectiveness of Rhizobium leguminosarum bv.
trifolii and N2 fixation,
glasshouse and laboratory studies were carried out with several soils,
biosolids, and biosolid application levels. Symbiotic effectiveness of
R. l. trifolii was estimated as the dry weight or N
content of seedlings of subterranean clover grown with only
N2 fixation and seed N as the available nitrogen
sources. The N fixed by legumes in unamended and biosolid-amended soils was
determined using the 15N isotope dilution method. Six
soils were represented in the experiments. Each of these was equilibrated over
a period of 12 months with dried, finely ground biosolids (DWS) from the
Malabar sewage treatment plant, at biosolids levels ranging from the
equivalent of 60 to 240 t DWS/ha. One of the soils was also equilibrated
with each of 4 other biosolids. The maximal concentration of heavy metals in
soil amended with biosolids was 1026 mg/kg.
The effect of biosolids on symbiotic effectiveness depended on the soil type
and biosolid applications level. Thus, biosolids reduced the symbiotic
effectiveness of R. l. trifolii in 2 of the 6 soils,
although at different levels of biosolid. In most soil treatments
N2 fixation was detected in subterranean clover,
confirming the persistence of symbiotically effective rhizobia in most
biosolids-amended soils. In addition, in strongly acidic soils plant N and
N2 fixation increased significantly with biosolids
addition, probably in response to higher soil pH, exchangeable Ca, and
available P. In the treatments in which the symbiotic effectiveness of
R. l. trifolii was reduced by biosolids, this was
reflected in poor N2 fixation. However, symbiotic
effectiveness did not correlate well with N2 fixation,
probably because increases in soil nitrate at higher biosolids levels
inhibited N2 fixation. Nevertheless, there were
instances at 240 t DWS/ha where this was unlikely to explain the decrease
in N2 fixation. It was concluded that adverse effects of
biosolids on symbiotic effectiveness depend first on soil type, and then on
biosolid type and application level; and the response in symbiotic
effectiveness to adding biosolids to soil needs to be determined for each
distinctively different site of biosolids reuse.
Porcine somatotropin (pST) administered using a commercial delivery system improves growth performance of rapidly growing, group-housed finisher pigs
Authors: Dunshea F. R. , Cox M. L. , Borg M. R. , Sillence M. N. , Harris D. R.
Published: September 2002

Porcine somatotropin (pST) treatment of pigs consistently improves average
daily gain (ADG) and feed conversion ratio (FCR). However, most studies have
been conducted with individually housed pigs, of unimproved genotype and over
a lighter finisher phase than current practice. The present study was designed
to determine whether a commercial pST (Reporcin) treatment regime would
improve growth performance in heavy boars and gilts (initial weight 79 kg) of
an improved genotype and housed under commercial conditions. The 2 2
factorial experiment involved 160, 19-week-old Large White Landrace pigs (80
males and 80 females) in 20 pens of 8 pigs/pen. The respective factors
were sex (boars and gilts) and dose of pST (0 and 5 mg/day). Pigs were fed
a wheat-based diet formulated to contain 200 g crude protein, 10.2 g available
lysine, and 14.6 MJ DE/kg to ensure that responses to pST and sex were
expressed. Injections of pST were given daily for 28 days prior to slaughter
using a commercial applicator designed for this purpose. Pigs were bled by
venipuncture on days 7 and 28 of treatment and the plasma samples analysed for
plasma urea nitrogen (PUN) and glucose. The degree of stomach ulceration at
slaughter was assessed by a veterinary pathologist. Daily pST treatment
increased ADG (P = 0.003), particularly in gilts,
as indicated by the interaction (P = 0.015)
between sex and pST. Thus, gilts treated with pST grew 23% faster than
control gilts (1093 v. 1273 g/day), whereas the
pST-treated boars grew only slightly faster (+2.5%) than control
boars (1261 v. 1291 g/day). Feed intake was similar
for boars and gilts and was decreased in both sexes by 10% during pST
treatment. FCR was higher in control gilts than in boars and was improved by
pST treatment. This was particularly evident in the gilts such that there was
no difference in the FCR of pST-treated gilts and boars. Back fat at slaughter
was reduced by 2.3 and 3.2 mm in boars and gilts treated with pST,
respectively. The only stomach lesions observed were very minor in severity
and there was no effect of pST on the proportion of pigs exhibiting stomach
ulcers (7/80 and 9/79 for control and pST-treated pigs, respectively;
χ2 = 0.31, P =
0.58) or visible possible injection site lesions (0/80 and 1/79;
χ2 = 1.01, P =
0.31). The PUN response mirrored the effects of sex and pST on FCR. Indeed,
there was a high correlation (R = +0.84,
P < 0.001) between FCR and PUN. In conclusion, pST
treatment of finisher pigs of an improved genotype and housed under simulated
commercial conditions improved growth performance, decreased back fat, and
negated sex differences.
A long-term experiment to study the role of mulches in the physiology and macro-nutrition of strawberry grown under water stress
Authors: Kirnak Halil , Kaya Cengiz , Higgs David , Gercek Sinan
Published: September 2002

Strawberry (Fragaria × ananassa Duch) cv. ‘Oso Grande’ was grown in
the field from July 1999 to May 2000 in order to investigate the effectiveness
of different mulch types on fruit yield, quality (i.e. soluble dry matter,
fruit size), leaf nutrient compositions, and normal plant growth parameters in
strawberry grown under water stress. Treatments were: (1) bare soil +
water stressed (WS), (2) bare soil + unstressed (control), (3) black
polyethylene mulch + water stressed (BPM + WS), (4) wheat
straw mulch + water stressed (WSM + WS), (5) wheat straw
mulch plus black polyethylene mulch + water stressed (WSM +
BPM + WS). Water stress was created by irrigating plants once every 3
days at 50% A pan (Epan) evaporation, compared with the control, which
received 75% daily. WS caused reductions in all parameters, except
water-soluble dry matter concentrations in fruits, compared with the control
treatment. Both BPM and WSM improved the fruit yield, fruit size, plant dry
matter, leaf area index, and chlorophyll concentrations in leaves in the
stressed treatments, while these 2 mulches in combination (BPM + WSM)
caused further increases in these parameters. WS enhanced electrolyte leakage
by impairing membrane permeability compared with control treatment. Mulching,
especially BPM and WSM together, substantially decreased electrolyte leakage.
WS reduced leaf concentrations of all nutrients tested (N, P, K, Ca, and Mg).
However, mulching, especially BPM and WSM together, enhanced the
concentrations of these nutrients, but their concentrations were still lower
than those in the control treatment. These results clearly indicate that
mulching mitigates negative effects of water stress on plant growth and fruit
yield in field-grown strawberry, particularly in semi-arid situations.
Rootstock influences postharvest anthracnose development in 'Hass' avocado
Authors: Willingham S. L. , Pegg K. G. , Cooke A. W. , Coates L. M. , Langdon P. W. B. , Dean J. R.
Published: September 2002

Rootstock studies conducted on ‘Hass’ avocado found that rootstock
had a significant impact on postharvest anthracnose susceptibility. This is
the first record of such an effect for avocado. The severity and incidence of
anthracnose was significantly lower on ‘Hass’ grafted to
‘Velvick’ Guatemalan seedling rootstock compared with the
‘Duke 6’ Mexican seedling rootstock. Differences in anthracnose
susceptibility were related to significant differences in concentrations of
antifungal dienes in the leaves and mineral nutrients in the leaves and fruits
from trees grafted to different rootstocks. Leaf diene concentrations were up
to 1.5 times higher in ‘Hass’ trees on the ‘Velvick’
than the ‘Duke 6’ rootstock. In ungrafted nursery stock trees,
diene concentrations were around 3 times higher in ‘Velvick’ than
‘Duke 6’ leaves. The ‘Velvick’/‘Hass’
combination also had a significantly lower leaf N concentration, a
significantly higher fruit flesh Mn concentration, and significantly lower and
higher leaf N/Ca and Ca+Mg/K ratios, respectively. A significant
correlation (r = 0.82) between anthracnose
severity and skin N/Ca ratio was also evident.
In sacco dry matter and nitrogen degradation and their relationship with in vitro dry matter digestibility of Napier grass (Pennisetum purpureum Schumach.) as influenced by height of plant at cutting
Authors: Zewdu Tessema , Baars Robert , Yami Alemu , Negassa Dawit
Published: September 2002

In vitro dry matter digestibility (IVDMD) as well as
in sacco rumen dry matter degradability (DMD) and
nitrogen degradability (ND) studies of Napier grass
(Pennisetum purpureum) were carried out using a 3 3
factorial experiment arranged in a randomised complete block design with 3
replications. The treatments were 3 levels of nitrogen (N) fertiliser (0, 46,
bacterium
Synergistes jonesii is known to degrade these compounds
and inoculation of the bacterium into the rumen protects cattle against
mimosine and DHP toxicity. We report on the development, production, and
storage of an in vitro, fermentor-based, mixed bacterial
inoculum, which includes S. jonesii, for administration
to cattle. This technique may be applicable to the production and delivery of
other live, anaerobic, bacterial inocula for use in animal agriculture.
Quantitative trait loci on chromosome 4B for coleoptile length and early vigour in wheat (Triticum aestivum L.)
Authors: Rebetzke G. J. , Appels R. , Morrison A. D. , Richards R. A. , McDonald G. , Ellis M. H. , Spielmeyer W. , Bonnett D. G.
Published: September 2002

The Norin-10 dwarfing genes, Rht-B1b
(Rht1) and Rht-D1b
(Rht2), are commonly used to reduce plant height and
increase grain yield in wheat breeding programs. These dwarfing genes lower
sensitivity of vegetative tissue to endogenous gibberellin to reduce cell and
subsequent stem elongation. This reduction in cell elongation capacity
reportedly results in a concomitant reduction in coleoptile length and early
vigour (leaf area) thereby affecting seedling establishment and growth. A
detailed genetic map from a cross between tall Halberd
(Rht-B1a) and semidwarf Cranbrook
(Rht-B1b) wheat cultivars was used to assess genetic
factors affecting seedling growth. Parental and 150 doubled haploid progeny
lines were characterised for seedling and height-related traits in controlled
and field environments. Genotypic variation was large and predominantly under
additive genetic control with evidence for transgressive segregation for some
traits. Narrow-sense heritabilities were moderate to high
(h2 = 0.31–0.91) indicating a strong
genetic basis for differences between progeny. Molecular marker analyses
identified a number of significant (P < 0.05)
quantitative trait loci (QTL) for each trait. A major QTL, mapping directly to
the Rht-B1 locus on chromosome arm 4BS, accounted for up
to 49% of the genotypic variance in peduncle length and plant height,
and 27–45% of the genotypic variance in coleoptile length across
different temperatures. Another QTL, located close to the RFLP marker
XksuC2 on the long arm of chromosome 4B, accounted for
15–27% of the genotypic variance in coleoptile length. The
influence of the XksuC2-linked QTL on coleoptile length
was greatest at 19˚C and decreased with cooler temperatures. The same QTL
affected reductions in leaf size, and both coleoptile tiller size and presence
to affect overall seedling vigour. There was also some evidence for epistatic
interactions influencing coleoptile tiller growth. Reductions in plant size at
the Rht-B1b and XksuC2 loci were
associated with presence of the Cranbrook 4B allele. The negative genetic
effect of the Rht-B1b dwarfing gene on early growth of
wheat confirms phenotypic evidence of a pleiotropic effect of
Rht-B1b on establishment and early vigour. Genetic
increases in coleoptile length and early leaf area development are likely to
be limited in wheat populations containing the Rht-B1b
dwarfing gene.
Grain proteins as markers of genetic traits in wheat
Authors: Cornish G. B. , Skylas D. J. , Siriamornpun S. , Békés F. , Larroque O. R. , Wrigley C. W. , Wootton M.
Published: September 2002

Different protein fractionation techniques were used to define differences
between a set of 8 wheat lines used in genetic mapping studies in Australia. A
proteomics approach was used to establish the feasibility of identifying new
protein polymorphisms for mapping purposes. Detailed analysis confirmed
differences in the glutenin subunits, gliadin proteins, and 10–20 other
proteins, between the mapping population parents, Cranbrook, Halberd, CD87,
and Katepwa. Differences were particularly evident in the low molecular weight
classes of protein. Alternative technologies were used to determine the
differences in various protein classes in order to screen doubled haploid
lines derived from crosses between the wheat lines. Polyacrylamide gel
electrophoresis analysis allowed the mapping of loci encoding high molecular
weight (HMW) and low molecular weight (LMW) glutenin subunit proteins.
Reversed phase high performance liquid chromatography also allowed several
loci encoding LMW glutenin subunit proteins to be mapped, as well as a new
protein on chromosome 6A. Capillary electrophoresis provided a high-resolution
system that was used to map several gliadin-type proteins. The studies showed
that proteins provide useful genetic markers and the data are discussed from
the point of view of the advantages that protein-based markers offer in
providing both genotypic and phenotypic data.
Implementation of markers in Australian wheat breeding
Authors: Eagles H. A. , Bariana H. S. , Ogbonnaya F. C. , Rebetzke G. J. , Hollamby G. J. , Henry R. J. , Henschke P. H. , Carter M.
Published: September 2002

Genetic associations of morphological, biochemical, and DNA markers with
economically important traits can be used for indirect selection of the
traits. Chromosomal linkage between pseudo-black chaff and the stemrust
resistance gene Sr2, and between the red glume gene
(Rg1) and the stripe rust resistance gene
Yr10, have been used in this way for many years.
Similarly, linkages between disease resistance genes, such as
Sr38,Lr37, and
Yr17, have been used to achieve resistance to multiple
diseases while selection is performed for resistance to one disease. Alleles
at the Glu loci, assessed as protein differences, have
been used as predictors of dough strength. More recently, DNA markers have
been developed and used, especially to select for resistance to cereal cyst
nematode, a trait which is difficult and expensive to assess with conventional
bioassays. We found that the major use of DNA markers was for selection for
traits of substantial economic importance, which were primarily determined by
a single gene, and where the non-marker assay was expensive and unreliable.
The other uses of markers were for pyramiding several genes influencing one
trait, or for rapid backcrossing.
Reliable and easy screening technique for salt tolerance of citrus rootstocks under controlled environments
Authors: García M. R. , Bernet G. P. , Puchades J. , Gómez I. , Carbonell E. A. , Asins M. J.
Published: September 2002

Three salt tolerance experiments using 5 common citrus rootstocks were carried out to find a reliable and easy screening technique for salt tolerance in breeding programs. The experiments were: (1) in vitro seed culture where salt tolerance was mainly evaluated as germination percentage, (2) hydroponic culture of 2-month-old seedlings where salt tolerance was mainly evaluated as survival percentage, and (3) hydroponic culture of satsuma-rootstock combinations where salt tolerance was evaluated by leaf and fruit characters. Treatments were: 4 mm K2CO3 and 0-100 mm NaCl in Expt 1; 3.5 mm K2CO3 and 0-50 mm NaCl, with and without K2CO3, in Expt�2; and 25 mm NaCl in Expt 3. Volkamer lemon was the most salt-sensitive genotype during seed germination (Expt�1), whereas Troyer citrange was the most sensitive when used as rootstock of satsuma (Expt 3). For seedling survival (Expt 2), the trifoliate orange variety Flying dragon showed the highest survival percentage, and chloride content of satsuma leaves and fruit juice were high on this rootstock under salinity (Expt 3). Alkalinity (pH = 8.5) greatly affected seedling survival of Cleopatra mandarin and Volkamer lemon (Expt 2), probably due to major disturbances in seedling nutrition. Analysis of trait values for the rootstocks in the different saline treatments in both the in vitro germination and the seedling survival experiments revealed some significant changes compared with control conditions. Most of these changes were not consistent between genotypes, except for chloride concentration in both shoot ([Cl]s) and root ([Cl]r).

The ordering of genotypes for salt tolerance found in the literature, which corresponds to the ordering as chloride excluders in our satsuma Expt 3, agrees with the inverse ordering of genotypes regarding the increment of both [Cl]s and the ratio [Cl]s/[Cl]r from control to low salinity, but does not agree with salt tolerance measured as a percentage of germination or seedling survival. The increments of both [Cl]s and the ratio [Cl]s/[Cl]r from control to low salinity are suggested as criteria for early selection of salt-tolerant citrus rootstocks. Three salt tolerance mechanisms have been observed: chloride exclusion, water saving, and accumulation of soluble solids. They all seem to be presented by Cleopatra mandarin when used as rootstock, supporting its utilisation as donor of salt tolerance in breeding programs of citrus rootstocks.
Factors contributing to proteolysis and disruption of myofibrillar proteins and the impact on tenderisation in beef and sheep meat
Authors: Hopkins D. L. , Thompson J. M.
Published: September 2002

This review seeks to examine the current theories of tenderisation with
respect to red meat where tenderisation is defined as the reduction in
toughness post-rigor. This examination is in the light
of recent research on meat biochemistry, and from this, areas of research that
may prove fruitful are highlighted. Based on available data, the major
candidate to explain tenderisation post-rigor is the
calpain protease system. Evidence that change in the binding of actomyosin
(the complex of contractile proteins formed at rigor) or
cleavage of myofibrillar proteins due to Ca2+ ions
contributes to tenderisation is far from compelling. Equally it appears that
the cathepsin proteases are unlikely to have a role in early post-mortem
cleavage of proteins (proteolysis) and thus tenderisation. The mode of action
of the calpains is not yet fully defined and questions remain as to the role
of m-calpain given the in vitro requirement for a
Ca2+ ion concentration exceeding that observed in
post-mortem muscle. The existence of the calpains in
living muscle and other tissues suggests a mode of action more subtle than
currently thought. Additionally, the observation that the degradation of
myofibrillar proteins occurs in the presence of effective synthetic and
natural calpain inhibitors suggests that other enzymes may also have a role in
tenderisation. Inevitably, the accumulated evidence points to a complex system
likely to involve interacting proteases and ions, and only through open minded
investigation with reliance on developments in the medical and biochemical
fields will a more complete model of tenderisation be developed.