Cycle de developpement, croissance et production de Sphaerium striatinum (Bivalvia : Pisidiidae) dans le Saint-Laurent (Québec)

1984 ◽  
Vol 62 (12) ◽  
pp. 2418-2424 ◽  
Author(s):  
B. Vincent ◽  
N. Lafontaine
Keyword(s):  
Life Span ◽  
Dry Weight ◽  
Individual Growth ◽  
Total Production ◽  
Maximum Increase ◽  
Total Growth ◽  
The Mean ◽  
Total Dry Weight ◽  
Individual Size ◽  
St Lawrence River

The life cycle of a population of Sphaerium striatinum in the St. Lawrence River (Québec) was studied over a 13-month period. This species has a life-span of 2–3 years and is iteroparous; individuals start producing young at the age of 1 year. Growth in length reached a maximum of 0.010 mm/day between the ages of 0 and 8 months, while the maximum increase in weight occurred during the 2nd year, representing 46% of the total growth. The mean population density was 737 individuals/m2 for the months of May to November 1979; the mean biomass values were 20.6 and 2.1 g/m2, respectively, for total dry weight and dry weight minus shells. Young of the year and yearlings combined represent 96% of the total production, which was calculated to be 14.9 g (total dry weight)/m2. The production to biomass ratio (P/B) decreased with the age of a generation and was 0.72 for the entire population. A comparison of our results with those in the literature indicates that individual growth rates are slower in the St. Lawrence population and that larvae, adults, and reproductive individuals are smaller in size; however, the population's life expectancy is greater. This longer life-span and smaller individual size, along with a delayed sexual maturity, can be explained by the environmental temperature regime.[Journal translation]

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.

Experimental Evidence of a Plant Meridian System IV.

1997 ◽  
Vol 25 (02) ◽  
pp. 135-142 ◽  
Author(s):  
T. Z. Hou ◽  
M. D. Li
Keyword(s):  
Sound Production ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Phaseolus Vulgaris L ◽  
Net Photosynthesis Rate ◽  
Bush Bean ◽  
Agricultural Plants ◽  
The Mean ◽  
Total Dry Weight ◽  
Growing Conditions

We have shown previously that plants exhibit functional characteristics similar to the meridian system in humans and animals, such as high potential and low electrical resistance, high temperature, and spontaneous sound production. Here we will show the effect of acupuncture on plants. When plants of Phaseolus vulgaris L. pole bean (cv. Kentucky wonder) and bush bean (cv. Slenderette) were subjected to acupuncture by inserting two needles into opposite sides of the stem of the unifoliolate buds, it was found that acupuncture strengthened the growth and development of the plants. Two repeated experiments showed that the mean net photosynthesis rate of plants subjected to acupuncture increased about 20.5%, the mean transpiration 27.2%, the growth and total length of internodes 22.5%, and the total dry weight of shoots from the cotyledon to the apex 22.9%, in comparisons with control plants under the same growing conditions. In addition, treated plants flowered three days earlier and had 14.4% more fruit than the untreated control plants. Thus, acupuncture may serve as a viable technique for increasing yield in agricultural plants.

scholarly journals Numbers and biomass of soil invertebrates in a reserved field in central Finland

1979 ◽  
Vol 51 (1) ◽  
pp. 172-187 ◽  
Author(s):  
Timo Törmälä
Keyword(s):  
Soil Surface ◽  
Dry Weight ◽  
Soil Invertebrates ◽  
Soil Invertebrate ◽  
Total Biomass ◽  
Invertebrate Community ◽  
Wet Weight ◽  
The Mean ◽  
Individual Size ◽  
Diptera Larvae

The numbers and biomasses of soil invertebrates were investigated in a reserved field in central Finland. Samples were taken monthly from June to September. Five methods were employed to extract the animals from the soil samples. The animals were counted, measured and their dry biomasses were estimated by body length/weight regressions and dry weight/wet weight ratios derived from the literature. In July the total biomass of the soil invertebrate community (excluding Protozoa, Tardigrada and Rotatoria) was about 9.6 g dry weight m-2. The most dominant groups were Lumricidae (73.1 %), Enchytraeidae (5,7 %), Oribatei (5.0 %), and Nematoda (4.4 %). In September the biomass of Diptera larvae was high (1.0 g dw m-2). In numbers nematodes were superior (maximum 12 million m-2) to other groups. Oribatei, Mesostigmata and Collembola were more concentrated to the soil surface than other Acari, Enchytraeidae and Nematoda. The mean individual size decreased with depth in all of the studied groups.

EFFECT OF ALAR ON DRY WEIGHT OF VARIOUS TISSUES OF GREENHOUSE GROWN APPLE TREES

1970 ◽  
Vol 50 (4) ◽  
pp. 481-484 ◽  
Author(s):  
S. R. MILLER
Keyword(s):  
Dry Weight ◽  
Apple Trees ◽  
Total Growth ◽  
Woody Tissues ◽  
Total Dry Weight

The total dry weights of greenhouse grown apple trees, taken 102 days after being sprayed with 1000 or 2000 ppm of Alar, was reduced. Alar at these rates caused an accumulation of photosynthate in the older stem and roots with a reduced growth of new wood. Trees harvested 182 days after treatment demonstrated that the inhibiting effects of Alar were dissipated. Those trees had made more total growth than the controls, the increase occurring as renewed terminal growth. Raising the concentration of Alar to 4000 ppm slightly increased the total dry weight after 53 days, the greater growth occurring in the older woody tissues. Little further growth took place 102 and 182 days after treatment. There was no indication that the inhibiting effects of Alar at 4000 ppm were lost in any tissue 182 days after application.

Effects of Sowing Date on Growth, Development and Yield of Photosensitive Sorghum at Samaru, Northern Nigeria

1975 ◽  
Vol 11 (3) ◽  
pp. 227-240 ◽  
Author(s):  
A. H. Kassam ◽  
D. J. Andrews
Keyword(s):  
Dry Weight ◽  
Grain Filling ◽  
Sowing Date ◽  
Growth Cycle ◽  
Head Development ◽  
Definite Effect ◽  
Filling Phase ◽  
Total Growth ◽  
Growth Development ◽  
Total Dry Weight

SUMMARYPerformance of Short Kaura, a photosensitive Nigerian sorghum, was compared at Samaru in ten sowings in 1972. Except for a two-week interval between the fifth and sixth sowings, all sowings were at weekly intervals from 12 May to 21 July. Total dry weight and grain yield decreased with delay in sowing after 26 May at the rate of 1700 kg.ha.−1 week−1 and 360 kg. ha.−1 week−1 respectively. Each week's delay in sowing after 12 May shortened the total growth cycle by 5·9 to 6·0 days, with 77 to 78 per cent in the vegetative phase, 7 to 8 per cent in the head development phase and 14 to 16 per cent in the grain filling phase. Although the date of head initiation seemed to be determined by photoperiod, sowing date also had a small but definite effect.

Population status of the bush fly, Musca vetustissima (Diptera: Muscidae), and native dung beetles (Coleoptera: Scarabaeinae) in south-eastern Australia in relation to establishment of exotic dung beetles

1996 ◽  
Vol 86 (2) ◽  
pp. 183-192 ◽  
Author(s):  
Marina Tyndale-Biscoe ◽  
W.G. Vogt
Keyword(s):  
Dry Weight ◽  
Dung Beetle ◽  
Dung Beetles ◽  
Population Status ◽  
Replacement Level ◽  
Onthophagus Taurus ◽  
Eastern Australia ◽  
Discomfort Threshold ◽  
The Mean ◽  
Total Dry Weight

AbstractWe compare the pest status and age structure of bush fly,Musca vetustissima Walker, populations, and the abundance of native dung beetles at Uriarra, ACT, for five fly seasons before (1976–81) and three seasons after (1990–93) the exotic dung beetles Euoniticellus fulvus (Goeze) and Onthophagus taurus (Schreber) became established in the area during the late 1980s. Fly populations in all post-introduction seasons of 1990–93 were much older than in the pre-introduction seasons, indicating reduced levels of local fly breeding and higher proportions of immigrants. During the pre-introduction period, the fly annoyance index exceeded the ‘minimum discomfort’ threshold of 10.0 in parts of all seasons. The mean index was 11.3, and this did not differ significantly between seasons. The total dry weight of dung beetles at the time of the first influx of bush flies each year was consistently below 3 g/dung pad which was apparently too low to depress bush fly breeding below their replacement level of 3%. The mean annoyance index of 3.1 for the 1990–91 season was significantly lower than for the pre-introduction period and the total dry weight of beetles during November-December exceeded 3 g/dung pad on all sampling occasions. In the 1991–92 and 1992–93 seasons fly annoyance indices reverted to pre-introduction levels (seasonal means of 13.7 and 7.8 respectively) and total dry weight of beetles was again below 3 g/dung pad when the bush flies first appeared. Survival of immature bush flies in local dung pads remained below the replacement level of 3% during 1990–91, but exceeded 3% on two occasions during 1991–92. Apart from 1976–77, when mean catches of native dung beetles (O. australis and O. granulatus) were exceptionally high, mean catches of native dung beetles during pre- and post-introduction years were very similar, but the mean dung beetle biomass increased following the establishment of exotic species.

scholarly journals Analysis of the Anticancer Phytochemicals inAndrographis paniculataNees. under Salinity Stress

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Daryush Talei ◽  
Alireza Valdiani ◽  
Mahmood Maziah ◽  
Sreenivasa Rao Sagineedu ◽  
Mohd Said Saad
Keyword(s):  
Salinity Stress ◽  
Morphological Traits ◽  
Dry Weight ◽  
Proline Content ◽  
Tolerance Index ◽  
Maximum Increase ◽  
Physiological Processes ◽  
Salinity Levels ◽  
Total Dry Weight ◽  
Salt Tolerance Index

Salinity causes the adverse effects in all physiological processes of plants. The present study aimed to investigate the potential of salt stress to enhance the accumulation of the anticancer phytochemicals inAndrographis paniculataaccessions. For this purpose, 70-day-old plants were grown in different salinity levels (0.18, 4, 8, 12, and 16 dSm−1) on sand medium. After inducing a period of 30-day salinity stress and before flowering, all plants were harvested and the data on morphological traits, proline content and the three anticancer phytochemicals, including andrographolide (AG), neoandrographolide (NAG), and 14-deoxy-11,12-didehydroandrographolide (DDAG), were measured. The results indicated that salinity had a significant effect on the aforementioned three anticancer phytochemicals. In addition, the salt tolerance index (STI) was significantly decreased, while, except for DDAG, the content of proline, the AG, and NAG was significantly increased (P≤0.01). Furthermore, it was revealed that significant differences among accessions could happen based on the total dry weight, STI, AG, and NAG. Finally, we noticed that the salinity at 12 dSm−1led to the maximum increase in the quantities of AG, NAG, and DDAG. In other words, under salinity stress, the tolerant accessions were capable of accumulating the higher amounts of proline, AG, and NAG than the sensitive accessions.

Size selection of common mussels, Mytilus edulis, by common eiders, Somateria mollissima: energy maximization or shell weight minimization?

1990 ◽  
Vol 68 (11) ◽  
pp. 2280-2283 ◽  
Author(s):  
Jan Ove Bustnes ◽  
Kjell Einar Erikstad
Keyword(s):  
Mytilus Edulis ◽  
Dry Weight ◽  
Somateria Mollissima ◽  
Shell Weight ◽  
Size Selection ◽  
Common Eiders ◽  
The Mean ◽  
Energy Maximization ◽  
Total Dry Weight ◽  
Selection Of

Prey size selection by common eiders, Somateria mollissima, preying on common mussels, Mytilus edulis, in northern Norway is described. The mean length (± 1 SD) of mussels preyed upon was 13.9 ± 5.7 mm (range 3.5–38.1 mm). The dry flesh weight as a percentage of the total dry weight ranged from 4.2 to 8.6% in different body-length categories and was greatest in the mussels most frequently fed upon. There was a close negative correlation between the size of mussels fed upon and the estimated total shell weight that birds had to ingest to obtain their daily requirement of food (rs = −0.86). A hypothesis is proposed that common eiders select mussels of certain size classes to minimize the daily shell weight intake.

scholarly journals Relationships Between the Yield and Vegetative Characteristics of Individual Shoots of `Cabernet Sauvignon' Grapevines

1990 ◽  
Vol 115 (4) ◽  
pp. 534-539 ◽  
Author(s):  
P.A. Bowen ◽  
W.M. Kliewer
Keyword(s):  
Positive Relationship ◽  
Shoot Growth ◽  
Light Exposure ◽  
Dry Weight ◽  
Growth And Yield ◽  
Cabernet Sauvignon ◽  
Cluster Number ◽  
Growth Duration ◽  
Total Growth ◽  
The Mean

Two-dimensional partitioning of variation was used to determine the sources of relationships between the yield and vegetative characteristics of three `Cabernet Sauvignon' grape (Vitis vinifera L.) clones. Clonal differences were found in shoot growth rate, but not in duration or total growth. A weak positive relationship between total shoot growth and yield resulted from a positive relationship between fruit set and growth duration. Relationships between cluster number and foliar characteristics indicated that light exposure in the previous year may have influenced both vegetative and reproductive development. The mean number of clusters per bud was positively related to the mean area, dry weight, and nitrogen content of leaves.

Relation Between Production and Biomass

1971 ◽  
Vol 28 (10) ◽  
pp. 1573-1581 ◽  
Author(s):  
K. Radway Allen
Keyword(s):  
Life Span ◽  
Simple Relation ◽  
Annual Production ◽  
Total Biomass ◽  
Total Production ◽  
Animal Populations ◽  
The Mean ◽  
Biomass Ratio ◽  
The Individual ◽  
Simple Growth

A series of mathematical models of cohorts in animal populations representing various combinations of several different simple growth and mortality functions is examined to investigate the ratio between mean biomass and production over unit time, and to compare this ratio with the mean age and mean life span of the animals in the cohort.For any cohort, the ratio of production per unit time to mean biomass is equal to the ratio of total production by the cohort to its total biomass integral by time. For populations consisting of a number of simultaneous, successive, or overlapping cohorts, the ratio of production per unit time to mean biomass is equal to the mean of the ratios for the individual cohorts weighted by the mean biomasses of the cohorts.If the cohorts are identical, the population ratio is the same as the cohort ratio and problems arising from the presence of more than one cohort may be ignored. Formulations for the total production per cohort, biomass integral, and, where they can be simplified, their ratios, are given.Comparison with mean age and mean life span shows that for constant exponential mortality, mean age and mean life span are both equal to the reciprocal of the production–biomass ratio. For other mortality functions, if growth in weight is linear, the production–biomass ratio equals the reciprocal of the mean age. For other models there is no simple relation. In general, mean age appears a better approximation than mean life span to the reciprocal of the production–biomass ratio.These methods are applied, as an example, to Antarctic krill, using a model having linear growth in length and four periods with different exponential mortality rates. For this model, annual production is 1.8 times the mean biomass so that assumption of equality leads to an underestimate of production. Mean age and mean life span are 0.21 and 0.037 years respectively. Thus, use of either of these as an approximation, and particularly mean life span, leads to severe overestimation of annual production.

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