A note on the relationship between the dry weight condition index and the glycogen content of adult oysters (Ostrea edulis L.) kept in the laboratory

1974 ◽  
Vol 35 (3) ◽  
pp. 359-361 ◽  
Author(s):  
P. A. Gabbott ◽  
R. R. Stephenson
Author(s):  
R. M. L. Kent

The dry weight condition index and water content of two groups of mussels, one with heavy infestations and the other with mild infestations of Polydora ciliata, were determined over a period of 15 consecutive months. The results were seasonally variable, but for most months the heavily infested mussels had a condition index significantly lower, and a water content significantly higher, than the mildly infested mussels. This suggests that heavy infestations of P. ciliata are associated with reduced flesh content in mussels.Further analyses of the body components of the two groups of mussels, showed that the mantle tissue of heavily infested mussels was reduced much more than the nonmantle tissue. Since the mantle is the main repository of gametes, this suggests that heavy infestations of P. ciliata might lower the fecundity of mussels.


2001 ◽  
Vol 13 (3) ◽  
pp. 271-279 ◽  
Author(s):  
Brent J. Sinclair ◽  
Heidi Sjursen

Cold tolerance of the springtail Gomphiocephalus hodgsoni Carpenter (Collembola: Hypogastruridae) was studied at Cape Bird, Ross Island, Antarctica (77°13′S, 166°26′E). Microclimate temperatures indicate a highly seasonal thermal environment, with winter minima <–39°C. Snow cover significantly buffers both minimum temperatures and cooling rates. Gomphiocephalus hodgsoni survives low temperatures by avoiding freezing. Mean low group supercooling points (SCPs) ranged from –35.4°C in October to –28.3°C in January. The lowest SCP measured was –38.0°C. The high SCP group was very small, making up only 18% of the population in January. In October, G. hodgsoni had a very high glycerol content (>80 μg mg−1 dry weight), although this declined rapidly to low levels (c. 7–10 μg mg−1 dry weight) in January. Quantities of glucose and trehalose were low during October, but steadily increased throughout the summer. Haemolymph osmolality was exceptionally high (up to 1755 mOsm kg−1) at the end of November, but this rapidly declined to c. 500 mOsm kg−1 by late December. The presence of thermal hystersis proteins was indicated by both osmometry on haemolymph samples and recrystallization inhibition studies of springtail homogenates. There was a strong relationship between glycerol content and SCP, but the relationship between haemolymph osmolality, SCP and carbohydrates is uncertain.


1979 ◽  
Vol 236 (3) ◽  
pp. E229 ◽  
Author(s):  
J S Kerr ◽  
N J Baker ◽  
D J Bassett ◽  
A B Fisher

We investigated the relationship between perfusate concentration of glucose and its utilization and lactate production derived from exogenous glucose and from metabolism of endogenous substrates. Isolated rat lungs were ventilated with 5% CO2 in air and perfused for 100 min with Krebs-Ringer bicarbonate buffer containing 3% bovine serum albumin, 10(-2) U/ml insulin, [U-14C]glucose and [5-3H]glucose. Glucose utilization, total lactate production, [14C]lactate production, and 3H2O production were measured. The apparent Km and Vmax for glucose utilization were 3.4 mM and 72.5 mumol/g dry wt per h, respectively. Lactate production from endogenous substrates, calculated as the difference between total and [14C]lactate, was 37.6 +/- 2.2 mumol/g dry wt (n = 36); it was unaffected by perfusate glucose concentration and by omission of insulin, but increased threefold with anoxia. Lactate production from 1.5 mM glucose was significantly less (P less than 0.02) with insulin omitted. Glycogen content was unchanged during perfusion without glucose. These results suggest that: 1) protein catabolism contributes to lung lactate production; 2) glucose utilization by lung is not maximal at resting physiological glucose concentrations; and 3) insulin is required at low glucose concentrations for maximal glycolytic rates.


Rangifer ◽  
2004 ◽  
Vol 24 (2) ◽  
pp. 87-94 ◽  
Author(s):  
Eva Wiklund ◽  
Timothy R. Manley ◽  
Roger P. Littlejohn

The ultimate pH value of meat (measured at approx. 24 hours post slaughter) gives information about the technological quality, i.e. shelf life, colour, water-holding properties and tenderness and is a direct consequence of muscle glycogen (energy) levels at slaughter. It may therefore also indicate whether or not the animal has been exposed to stressful energy depleting events prior to slaughter. In the present study, 141 animals (130 red deer (Cervus elaphus) and 11 fallow deer (Dama dama) were included to investigate the relationship between ultimate pH and residual glycogen concentration in red deer and fallow deer M. longissimus. In addition, the muscle glycogen content and ultimate pH values in three red deer muscles (Mm. triceps brachii, longissimus and biceps femoris) were studied. M. triceps brachii had higher ultimate pH and lower glycogen content compared with the other two studied muscles. The frequency of intermediate DFD (5.8≤ pH<6.2) was 5.4% in red deer M. longissimus, compared with 9.1% in fallow deer, while the frequency of DFD (pH≥ 6.2) was much lower in red deer (3.8%) than in fallow deer (54.5%). A curvilinear relationship between ultimate pH and total glucose concentration (glycogen and glucose) 30 min post slaughter in red deer and fallow deer M. longissimus was found. The relationship between muscle pH and lactic acid concentration however, was indicated to be linear. A significant variation in total glucose concentration at ultimate pH below 5.80 was observed, including values in the range from 18 to 123 mmol/kg wet tissue. It was concluded that further studies are needed to further explore the relationship between muscle glycogen content and technological and sensory quality attributes of meat from different deer species.Abstract in Swedish / Sammanfattning:Köttets pH-värde (mätt ca 24 timmar efter slakt) har stor betydelse för den teknologiska kvaliteten som t. ex. hållbarhet, färg, vattenhållande förmåga och mörhet. Glykogenförrådet (energinivån) i djurens muskulatur vid slakt är helt avgörande för köttets slutliga pH-värde. Därför kan pH-värdet också indikera om hanteringen av slaktdjur varit skonsam eller om stora mängder muskelenergi har förbrukats vid stress. I vår undersökning ingick 141 hjortar (130 kronhjortar (Cervus elaphus) och 11 dovhjortar (Dama dama) för att studera sambandet mellan köttets pH-värde och glykogeninnehållet i M. longissimus. Glykogeninnehåll och pH-värden i 3 muskler från kronhjort (Mm. triceps brachii, longissimus och biceps femoris) undersöktes också. M. triceps brachii hade högre pH-värde och lägre glykogeninnehåll jämfört med de två andra musklerna. Det var inte så stor skillnad i frekvensen av intermediär DFD (pH-värden mellan 5,8 og 6,2) mellan de två hjortarterna (5,4% för kronhjort och 9,1% för dovhjort), däremot var frekvensen av DFD (pH-värden över 6,2) mycket låg hos kronhjort (3,8%) jämfört med dovhjort (54,5%). Det fanns ett kurvlinjärt samband mellan slutligt pH-värde i köttet och total glukoskoncentration (glykogen + glukos) mätt i M. longissimus 30 min efter slakt för både kron- och dovhjort. Ett linjärt samband mellan pH-värde och koncentration av mjölksyra i M. longissimus kunde också visas. Vi fann en mycket stor varitation i glukoskoncentration (18−123 mmol/kg våtvikt) när köttets pH-värdet var 5,8 eller lägre. Det behövs fler undersökningar för att vidare klargöra sambanden mellan glykogeninnehåll i muskulaturen och teknologisk och sensorisk kvalitet i olika typer av hjortkött.


2021 ◽  
Vol 905 (1) ◽  
pp. 012002
Author(s):  
C Prayogo ◽  
C Muthahar ◽  
R M Ishaq

Abstract The cause of global warming is the increasing carbon concentration arising from industrial activities, burning of fossils, and land-use change. The purpose of this research was to find out the allometric equation to calculate the local bamboo biomass and then to be able to calculate how much carbon sequestration at bamboo riparian forest since this area was rarely being explored. The parameters observed were the height and diameter of the bamboo stem at 1.3 m height of 6 types of local bamboo using destructive sampling, along with the measurement of bamboo weight. The carbon content of the bamboo biomass, litter, and soil was measured to complement the estimation of total carbon sequestration. The results showed that the allometric equation for estimating local bamboo biomass is Y=0.6396 X1.6162 with R2=0.77, obtained from the relationship equations between dry weight and the diameter. Total carbon sequestration of this system ranged between 81 to 215 tons C ha−1.


2016 ◽  
Vol 8 (1) ◽  
pp. 20 ◽  
Author(s):  
M. Bänziger ◽  
G. O. Edmeades ◽  
J. Bolaños

The amount of dry matter produced during various stages of corn growth is a important variable to be taken into consideration. However, the lack of drying facilities makes its measurement a difficult task in the fields. A simple method to convert the fresh weight of a crop in the field into dry weight, could be an answer to that problem. In this study, we calculated the relationship between fresh and dry weight of corn stovers, over several, growth, stages of eight corn cultivars of different vigour and maturity period, at two Mexican locations. The differences between cultivars were for percent stover dry weight (%SDW) most evident in the second half of the grain growth stage, when late cultivars showed less humidity than the early ones. The % SDW was regressed against the phenological developmental stage and expressed as a ratio against antesis (R, days to sampling /days to 50% antesis). The equations (R2 = 0.97 - 0.99) with best results were: Early maturing cultivars: %SDW = 12.6 + 0.94R2 + 1.68R4; Late: %SDW = 16.1 - 4.00 R2 + 3.36R4. There were no consistant differences among cultivars with different vigour levels, even though certain differences were noted among the locations and they were attributed to differences in relative humidity. We describe a protocol for determining the dry weight of corn stover by area unit (t/ha) when drying conditions are not available, by utilizing only a scale and a ruler.We also suggest a method to calculate percent dry matter for a real plant parts (including grain).


1984 ◽  
Vol 62 (9) ◽  
pp. 1781-1790 ◽  
Author(s):  
S. I. Warwick ◽  
B. K. Thompson ◽  
L. D. Black

Thirteen populations of Sorghum halepense, Johnson grass, were sampled from fields in Ontario, Canada, and Ohio and New York, United States. Only four of these populations were reported to overwinter as rhizomes. The morphology, phenology, resource allocation patterns, and growth of seedling and mature plants of the overwintering and the non-overwintering populations were compared. Field-collected specimens from the nonoverwintering populations had wider culms and leaves and larger seeds and inflorescences. Analysis of material grown in a 5-month greenhouse trial indicated similar differences. Greenhouse plants from the nonoverwintering populations were also characterized by greater percent emergence, larger and faster growing seedlings, earlier flowering, larger culms and seeds, greater reproductive dry weight per plant, and about 1/10th the rhizome dry weight of overwintering plants. Differences between populations within a biotype were evident for both biotypes, although there was little within-population variation, except in rhizome production, where certain individuals of some nonoverwintering populations did not produce extended rhizomes. Among the five enzymes which were examined electrophoretically, only one, phosphoglucomutase (PGM), showed variable isozyme patterns. No differences in enzyme patterns were apparent between the overwintering and the nonoverwintering biotypes. The relationship of the nonoverwintering populations to the cultivated species, Sorghum bicolor and S. almum, an introgressant between S. halepense and S. bicolor, is discussed.


1979 ◽  
Vol 59 (3) ◽  
pp. 585-601 ◽  
Author(s):  
G. O. EDMEADES ◽  
T. B. DAYNARD

In an attempt to explain plant-to-plant variation in dry weight of maize (Zea mays L.), a computer program was developed to predict daily assimilation per plant and its distribution throughout the shoot at flowering. Inputs to the model were meteorological data, photosynthetic rate-irradiance curves, measurements of intraplant assimilate distribution at flowering, and the positions of individual leaves of plants grown in the field at three densities (50 000, 100 000 and 150 000 plants/ha). Dry weights were recorded on these same plants following black layer formation. Predicted effects of plant density on shoot growth compared favorably with available data. The correlation coefficient between predicted assimilation 1 day after anthesis and grain yield on the same plants, with treatment effects removed, was 0.67 (N = 360). The coefficient of variation of predicted assimilate flux per plant increased significantly with increasing density, and the fluxes were generally normally distributed. Results supported the concept of a threshold assimilation rate per plant below which grain would not normally form, and this appears to be the cause of the bimodal frequency distribution of grain yield per plant observed at high densities.


Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1719
Author(s):  
Nurfarhana Diana Mohd Nor ◽  
Stella Lignou ◽  
Luke Bell ◽  
Carmel Houston-Price ◽  
Kate Harvey ◽  
...  

Glucosinolates (GSLs) are phytochemical compounds that can be found in Brassica vegetables. Seven separate batches of steamed-pureed turnip were assessed for GSL content using liquid chromatography mass spectrometry (LC-MS) and for sensory attributes by sensory profiling (carried out by a trained sensory panel). Twelve individual GSLs, which included 7 aliphatic, 4 indole and 1 arylaliphatic GSL, were identified across all batches. There were significant differences in individual GSL content between batches, with gluconasturtiin as the most abundant GSL. The total GSL content ranged from 16.07 to 44.74 μmol g−1 dry weight (DW). Sensory profiling concluded there were positive correlations between GSLs and bitter taste and negative correlations between GSLs (except glucobrassicanapin) and sweet taste. The batches, which had been purchased across different seasons, all led to cooked turnip that contained substantial levels of GSLs which were subsequently all rated as bitter.


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