Comparative accumulation of Alkaline-earth metals by two freshwater Mussel species from the Nepean River, Australia: Consistences and a resolved Paradox

1993 ◽  
Vol 44 (4) ◽  
pp. 609 ◽  
Author(s):  
RA Jeffree ◽  
SJ Markich ◽  
PL Brown
Keyword(s):  
Alkaline Earth ◽  
Tissue Concentration ◽  
Freshwater Mussel ◽  
Dry Weight ◽  
Alkaline Earth Metals ◽  
The Other ◽  
Tissue Concentrations ◽  
South Wales ◽  
Solubility Constant ◽  
The Mean

Whole tissue concentrations of Be, Mg, Ca, Sr, Ba and 226Ra were determined in Hyridella depressa (Lamarck) and Velesunio ambiguus (Philippi) from a minimally polluted region in the Upper Nepean River, New South Wales. Although the mean tissue concentrations of each metal were comparable between the two species, their patterns of accumulation were dissimilar. For each metal, tissue concentration was significantly correlated (P≤0.01) with tissue dry weight and shell length in H. depressa, but not in V. ambiguus, in which variability between individuals was high and Mg concentration was inversely correlated (P≤0.05) with tissue dry weight. However, in each species the Ca concentration was a highly significant (P≤0.001) positive predictor of the concentration of each of the other metals. For each species, normalized rates of accumulation of the metals, relative to increasing Ca concentration and/or size, were 226Ra >Ba≥Sr>Ca > Mg; these rates were inversely related (P≤0.05) to their solubilities as hydrogen phosphates. This inverse relationship was used to predict a solubility constant for BeHPO4. The results were consistent with those previously obtained for V. angasi (Sowerby). The metal solubility relationships, based on the relative increases in the tissue concentrations of each metal over the range of Ca concentrations, held for both species even though V. ambiguus showed no significant (P>0.05) increase in tissue concentrations with size. This paradox can be explained as follows. In both species the Ca tissue concentration is a measure of the total influx and efflux of Ca and its analogues through the tissue of an individual over its lifetime; however, in V. ambiguus this total flux is unrelated to mussel size. The use of Ca concentration to predict concentrations of the other metals was effective in explaining up to 98% and 95% of the variability between individual mussels of H. depressa and V. ambiguus respectively. Hence, the problem of inherent variability between individuals can be eliminated. This will permit any spatial and/or temporal differences in the tissue concentrations of alkaline-earth metals of mussel populations to be more readily discerned.

Cycle de développement, croissance et production de Pisidium amnicum (Mollusca: Bivalvia) dans le Saint-Laurent (Québec)

1981 ◽  
Vol 59 (12) ◽  
pp. 2350-2359 ◽  
Author(s):  
B. Vincent ◽  
G. Vaillancourt ◽  
N. Lafontaine
Keyword(s):  
Population Dynamics ◽  
Sexual Maturity ◽  
Dry Weight ◽  
Mortality Rates ◽  
The Other ◽  
Annual Production ◽  
Bithynia Tentaculata ◽  
The Mean ◽  
Total Dry Weight ◽  
St Lawrence River

The population dynamics of Pisidium amnicum have been studied in one population of the St. Lawrence River over a 2-year period during which 19 samples were taken. The species can live up to 3 years and it is iteroparous; individuals generally attain sexual maturity after 1 year and they reproduce twice, once at 2 and once at 3 years of age. In adults, mortality is lower in winter than during the rest of the year and mortality rates are twice as high during the 1st year than during the 2nd year. Total dry weight (PT, in milligrams) is related to maximum length (L, in millimetres) according to the equation PT = 0.0283∙L3,80 and flesh dry weight (PC, in milligrams) is related to length as follows: PC = 0.007∙L3,18. The annual production to mean biomass (P/B) ratio is 1.4, the mean annual production being 1.298 mg/m2 of total dry weight and 107 mg/m2 of flesh weight. Comparing these results with those obtained for the gastropod Bithynia tentaculata in the same environment and at the same period of the year has shown that the growth of Pisidium amnicum is far less influenced by the temperature regime than that of the other species and that its production is at least 10 times lower.

Analysis of the environment of beryllium, magnesium and alkaline earth atoms in oxygen-containing compounds

1999 ◽  
Vol 55 (2) ◽  
pp. 139-146 ◽  
Author(s):  
V. A. Blatov ◽  
L. V. Pogildyakova ◽  
V. N. Serezhkin
Keyword(s):  
Crystal Structure ◽  
Alkaline Earth ◽  
Organometallic Compounds ◽  
Alkaline Earth Metals ◽  
The Other ◽  
Crystal Chemical ◽  
Coordination Polyhedra ◽  
Coordination Numbers ◽  
Coordination Spheres

About 2100 inorganic and organometallic compounds containing beryllium, magnesium and alkaline earth atoms (M) were investigated with Voronoi–Dirichlet polyhedra (VDPs). It is shown that the coordination numbers (CNs) of the M atoms in MO n coordination polyhedra can be determined by means of VDPs without crystal-chemical radii. The distributions of the M—O distances in the coordination spheres of the M atoms are bimodal for M = Be or Mg and monomodal for the other alkaline earth metals. Beryllium and magnesium coordination polyhedra containing weak M—O contacts were classified by variants of their distortions. It is found that the volume of the domains of the Mg, Ca, Sr and Ba atoms is independent of their CNs at CN \ge 6 (up to 16 for barium). The possibility of using the model of deformable spheres to describe the crystal structure of the compounds investigated is suggested.

Evaluation of Bos indicus and Bos taurus straightbreds and crosses. II. Post-weaning growth, puberty, and pelvic size of heifers

1994 ◽  
Vol 45 (4) ◽  
pp. 795 ◽  
Author(s):  
H Hearnshaw ◽  
PF Arthur ◽  
R Barlow ◽  
PJ Kohun ◽  
RE Darnell
Keyword(s):  
Body Condition ◽  
Bos Taurus ◽  
Body Condition Score ◽  
Bos Indicus ◽  
The Other ◽  
South Wales ◽  
Condition Score ◽  
Medium Quality ◽  
The Mean ◽  
Pelvic Size

Post-weaning growth and body condition, puberty and pelvic size of 197 heifers comprising straightbred Hereford (HxH) and Brahman (BxB), first-cross (BxH) and back-cross (HxBH and BxBH) heifers were evaluated. The heifers were born over a 3 year period, and grazed improved and semi-improved pastures following weaning at Grafton, New South Wales. Prior to weaning, heifers had been reared by dams on three pasture systems (high, medium and low quality pastures). Heifers from low quality pre-weaning pasture had higher (P < 0.05) post-weaning liveweight gain than those from high and medium quality pastures. BxH heifers gained 71 g/day more (P < 0.05) than the mean gain of their contemporaries of the other genotypes, whose gains were similar, from weaning to either 26 or to 30 months of age. Liveweight at all ages was influenced by genotype x pre-weaning pasture system interaction. At 30 months of age, BxH heifers from high and medium pre-weaning pastures were the heaviest. At the same age, but from low quality pre-weaning pasture, heifers with crossbred dams (HxBH and BxBH) were the heaviest. Wither height depended significantly (P < 0.05) on the proportion of Bos indicus genes, increasing from 113.8 cm in the HxH heifers to 124.4 cm in the BxB heifers at 30 months of age. BxH heifers had a higher (P < 0.05) body condition score than their contemporaries of the other genotypes, which were in similar condition, at 26 and 30 months of age. On average (across pre-weaning pasture system), 9% of BxB heifers had reached puberty by 22 months of age compared to 62, 95, 82 and 64% (s.e.= 9) for HxH, HxBH, BxH and BxBH heifers respectively. No significant genotype differences were obtained in the height, width and size of the pelvic opening of the heifers, measured just prior to the beginning of the mating season at 26 months of age.

Effect of prolonged undernutrition on the recovery and reproductive performance of maiden Merino ewes

1967 ◽  
Vol 7 (24) ◽  
pp. 7 ◽  
Author(s):  
P McInnes ◽  
TJ Grainger ◽  
MD Smith
Keyword(s):  
Body Weight ◽  
Reproductive Performance ◽  
New South ◽  
New South Wales ◽  
The Other ◽  
First Year ◽  
Treatment Groups ◽  
South Wales ◽  
Feeding Trials ◽  
The Mean

Data are presented on the recovery and reproductive performance of 2 1/2-year-old maiden Merino ewes after a prolonged period of undernutrition. The 217 sheep had been hand-fed on a submaintenance ration in pen feeding trials at Glenfield, New South Wales. During the seven months of the trials they had lost 6 kg (28 to 22 kg) body weight. They were transported to Condobolin in south-western New South Wales, divided into two treatment groups and run on good quality pastures. One group was joined immediately (May 1959) and again ten months later, and the other group was mated after six months at Condobolin (in October 1959) and again 12 months later. The ewes recovered rapidly. The mean weight of both groups had reached 30 kg within six weeks and 40 kg within six months. In the first year 73 of the 100 May-mated ewes bore lambs, but only 38 of these lambs were weaned. Ewes bearing lambs had a higher body weight at the start of joining and gained more during joining than the barren ewes. At the other three joinings (October 1959, May 1960, October 1960) lambing percentage was from 86-89 and weaning percentage from 62-69-both normal for the district. The proportion of twin lambs (3-6 per cent) was low. Wool weight in 1959 was not affected by time of mating or by pregnancy.

Methods of analysing competition with special reference to herbage plants: I. Establishment

1973 ◽  
Vol 81 (1) ◽  
pp. 77-89 ◽  
Author(s):  
J. Hill ◽  
Y. Shimamoto
Keyword(s):  
Special Reference ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Natural Populations ◽  
Dry Weight ◽  
The Other ◽  
Replacement Series ◽  
Genotype Combination ◽  
South Wales ◽  
Gains And Losses

SummaryA diallel arrangement, which incorporated the essential features of the de Wit density replacement series, was employed to study the effects of competition amongst five genotypes of perennial ryegrass (Lolium perenne). Of the five genotypes concerned two were derived from S·24, two were collected from natural populations in South Wales, while the remaining genotype originated from S· 23. These five genotypes were grown as monocultures and in all ten binary combinations. Within each combination there were three mixture proportions, namely 75:25, 50:50 and 25:75. All mixtures and monocultures were represented by two boxes, one of which was cut at 3-week intervals (frequent cutting) the other being cut at 6-week intervals (infrequent cutting). At each cut all plants within the appropriate mixtures and monocultures were harvested individually and their dry weight recorded.The results obtained over the first 18 weeks of the experiment (i. e. the first three complete growing periods) establish that competition is occurring in nine of the ten binary combinations. Within these nine combinations competition may be classified into one of three groups: first, it may be compensatory, in which the gains and losses incurred by the two components counterbalance; secondly, it may be positive complete complementation, where the advantage gained by the stronger component is such that the mixture performance matches that of the better monoculture, and thirdly, it may be positive over-complementation, where the yield of the better monoculture is surpassed by the mixture. Further tests disclose that a long-leaved S· 24 genotype is the strongest competitor, while a short-leaved, prostrate, indigenous genotype proves to be by far the weakest competitor.Estimates of the equilibrium proportions for each genotype combination suggest that most combinations are expected to become monocultures of the strongest component, with only the combination between the long-leaved indigenous and longleaved S· 23 genotypes remaining a mixture at equilibrium. None of these equilibria coincides with the proportions required to achieve maximum productivity from a particular combination. The results are considered in relation to the known characteristics of these five perennial ryegrass genotypes, while the wider agronomic implications are also discussed.

Heterosis and combining ability effects on cotton. II. Heterosis

1988 ◽  
Vol 39 (6) ◽  
pp. 991 ◽  
Author(s):  
NJ Thomson ◽  
DJ Luckett
Keyword(s):  
New South ◽  
Commercial Production ◽  
River Valley ◽  
The Other ◽  
Diverse Range ◽  
Yield And Quality ◽  
South Wales ◽  
Commercial Cultivars ◽  
The Mean

The yield and quality of a diverse range of cotton hybrids was measured in one, or more, of a number of experiments conducted in the Ord River valley, Western Australia (15�S.) and the Namoi River valley, New South Wales (30�S.). Two of the experiments were diallels, one involving nine parents, the other thirteen parents. In both the plant and subsequent ratoon crops, mean yield of the hybrids was significantly greater than the mean yield of the parents, and the hybrids had significantly longer and stronger fibre. A few hybrids in both diallels significantly outyielded commercial controls by between 15 and 35% in both the plant and ratoon crops. Subsequently, in other experiments including one with near-commercial large plots, the high performers from the diallel experiments were inconsistent for yield, usually exhibiting little or no heterosis above that of the best commercial cultivars. Other hybrids tested in these experiments also generally failed to outyield the commercial controls, although a number had higher-quality fibre. It was concluded the heterosis for yield is not consistent enough under high-yielding Australian conditions to warrant the commercial production of hybrid cotton seed. Some hybrids, however, especially the interspecific G. hirsutum x G. barbadense ones, have the stronger, finer fibre that appears better suited to cotton spinning equipment now being developed, and this aspect could justify reappraisal of this conclusion in the future.

Evaluation of Hereford and first-cross cows on three pasture systems. II. Growth of Hereford and Brahman sired calves out of mature cows

1994 ◽  
Vol 122 (1) ◽  
pp. 131-138 ◽  
Author(s):  
H. Hearnshaw ◽  
P. F. Arthur ◽  
P. J. Kohun ◽  
R. Barlow
Keyword(s):  
Average Daily Gain ◽  
The Other ◽  
Weaning Weight ◽  
South Wales ◽  
Medium Quality ◽  
The Mean ◽  
Main Effects ◽  
Calving Difficulty ◽  
Daily Gain ◽  
Sire Breed

SUMMARYThe preweaning growth of the progeny of mature cows grazing high, medium or low quality pasture was evaluated. The cows were 5–9 years of age at the beginning of the study and were either purebred Hereford (H x H), first-cross Brahman x Hereford (B x H), Simmental x Hereford (S x H) or Friesian x Hereford (F x H). Hereford and Brahman bulls were mated to these cows for three mating seasons commencing in 1982, at Grafton, New South Wales, Australia. Records on 634 calves born over three consecutive years were used.Most traits were subject to significant sire breed or dam breed effects or their interactions with one or more of the other main effects (pasture, year of birth of calf, cow age and sex of calf). The incidences of calving difficulty and stillbirths were exceptions. Stillbirths (mean of 3·8%) were not affected by any of the effects studied, while calving difficulty was affected only by sex of calf effect (males, 3·9%; females, 0·8%). The mean calving date of Brahman-sired calves was 11·4 days later (P < 0·05) than that of Hereford-sired calves. Differences between Brahman-sired and Hereford-sired calves for weaning weight were not significant for S x H (Brahman, 237 kg; Hereford, 232 kg) and FxH (Brahman, 238kg; Hereford, 238kg) dams. For HxH dams however, calves sired by Brahman were heavier at weaning (205 kg) than those sired by Hereford (193 kg) bulls, while for B x H dams the reverse was true (Brahman, 222 kg; Hereford, 231 kg). For calves with B x H dams average daily gain (ADG) was the same (957 g/day) for each sire breed, while for the other dam breeds, Brahman-sired calves had a higher ADG than Hereford-sired calves (862 v. 779, 1014 v. 946 and 1022 v. 950 g/day for H x H, S x H and FxH, respectively). Calves sired by Brahman bulls had > 90% eyelid pigmentation while Hereford-sired calves had 44–74%. On high quality pasture, the weaning weights and ADG of calves of F x H and S x H dams were higher than those of B x H and HxH dams. On medium quality pasture, weaning weight of calves of crossbred dams (B x H, S x H and FxH) were similar but higher than those of H x H dams. On low quality pasture, mean weaning weight of calves of B x H was higher than those of S x H and F x H dams, which in turn, were higher than that of H x H dams.

The incidence of crown rot in wheat, barley and triticale when sown on two dates

1989 ◽  
Vol 29 (4) ◽  
pp. 559 ◽  
Author(s):  
TA Klein ◽  
LW Burgess ◽  
FW Ellison
Keyword(s):  
New South ◽  
Sowing Date ◽  
The Other ◽  
Crown Rot ◽  
Wheat Cultivars ◽  
Potential Yield ◽  
South Wales ◽  
The Mean ◽  
Fusarium Graminearum Group 1 ◽  
Group 1

Thirteen bread wheat cultivars, a durum wheat, a barley and a triticale cultivar were assessed in the field for their reaction to crown rot (Fusarium graminearum Group 1), based on the incidence of basal browning. Plots were sown in May and again in July at 2 sites i n northern New South Wales where the incidence of crown rot was high in the previous year. The incidence of infected plants and the incidence of plants with basal browning tended to be higher in all cultivars when sown in May. There was a mean loss in potential yield at 1 site of 35% and 18% at the other site. However, the mean loss in potential yield was unaffected by sowing date.

The distribution of coenzyme Q in the tissues of the gravid ewe and fetus

1969 ◽  
Vol 47 (6) ◽  
pp. 571-573
Author(s):  
M. Hidiroglou
Keyword(s):  
Fetal Heart ◽  
Fetal Liver ◽  
Coenzyme Q ◽  
The Other ◽  
Tissue Concentrations ◽  
Embryonic Life ◽  
The Mean ◽  
Mean Concentration

Data on coenzyme Q tissue concentrations were obtained from 26 ewes and their fetuses from 50 days postconception to term. Coenzyme Q concentrations were low in early embryonic life. A significant increase was observed in coenzyme Q concentration in the 4-month-old or older fetal heart and kidney. The mean concentration of coenzyme Q in fetal liver increased also with advance in gestation but with less consistency than in the other tissues.

SKELETAL SILVER CATALYSTS FOR THE OXIDATION OF ETHYLENE TO ETHYLENE OXIDE

1956 ◽  
Vol 34 (5) ◽  
pp. 665-671 ◽  
Author(s):  
A. Cambron ◽  
W. A. Alexander
Keyword(s):  
Ethylene Oxide ◽  
Alkaline Earth ◽  
Specific Activity ◽  
High Specific Activity ◽  
Alkaline Earth Metals ◽  
The Other ◽  
Silver Alloys ◽  
Silver Catalysts

Skeletal silver catalysts of high specific activity have been prepared by the removal of calcium from calcium–silver alloys. The activity of these catalysts in the oxidation of ethylene to ethylene oxide has been investigated. Catalysts prepared by the removal of the other alkaline earth metals from their alloys with silver have also been studied. It has been found that catalysts prepared from calcium–silver alloys show a higher specific activity and are more stable and more conveniently prepared than the catalysts from the other silver alloys investigated.

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