Analysis of Energy Flow and Production in an Unexploited Marine Flatfish Population

1973 ◽  
Vol 30 (11) ◽  
pp. 1717-1728 ◽  
Author(s):  
J. C. MacKinnon
Keyword(s):  
Energy Intake ◽  
Energy Flow ◽  
Analytical Approach ◽  
Total Population ◽  
Seasonal Pattern ◽  
Ecological Efficiency ◽  
Resident Population ◽  
Net Production ◽  
Production Processes ◽  
Hippoglossoides Platessoides

The seasonal pattern of production processes in an unexploited resident population of American plaice (Hippoglossoides platessoides) in St. Margaret’s Bay, N.S., was analyzed with an energetics model which represents an extension of the analytical approach used in fishery theory. During summer, production is about twice the annual net production of 1.5 kcal/m2 by fish aged 1 and up. The ecological efficiency is 17%, with larvae and 0+ fish accounting for some 20% of total population ingestion and 34% of net population production. Metabolic expenditures constitute the largest fraction (62%) of population energy intake and about 80% of this amount is consumed during summer. Plaice ingest about half the yearly estimated production (25 kcal/m2) of benthos in the deeper parts of the Bay.

Energy Flow and Secondary Production of the Amphipods Hyalella azteca and Crangonyx richmondensis occidentalis in Marion Lake, British Columbia

1971 ◽  
Vol 28 (5) ◽  
pp. 711-726 ◽  
Author(s):  
Jack A. Mathias
Keyword(s):  
Population Growth ◽  
Energy Flow ◽  
Standing Crop ◽  
Production Efficiency ◽  
Hyalella Azteca ◽  
Growth Efficiency ◽  
Ecological Efficiency ◽  
Net Production ◽  
Annual Basis ◽  
Predator System

The Hyalella azteca population in Marion Lake, B.C., assimilated and produced about three times as much energy as did the Crangonyx richmondensis occidentalis population from May 1966 to May 1967, but during the summer the energy flow of H. azteca was four times, and production was five times, that of C. r. occidentalis.Hyalella azteca was abundant at a depth of 1.0 m (mean summer standing crop, 1952 animals/m2), but was rare (75 animals/m2) at depths greater than 2.5 m. Growth, molting, respiration, and hence energy flow rates decreased with depth, due (in part) to lower ambient temperatures in deeper water. On an annual basis, a mean standing crop of 1.1 kcal/m2 of H. azteca assimilated 18.1 kcal/m2, respired 13.5 kcal/m2, and used 4.6 kcal/m2 in production of growth, molts, and eggs. Approximately two-thirds of the annual energy flow was completed between June and October. On an annual basis, the ecological efficiency of an H. azteca-predator system was in the range 2.5–12.5%, the net production efficiency was 25%, and the net population growth efficiency was 16%.The mean summer density of C. r. occidentalis remained constant with depth (about 283 animals/m2). Annual energy flow and production were not appreciably affected by lower temperatures in deeper water. On an annual basis, a mean standing crop of 0.7 kcal/m2 assimilated 6.5 kcal/m2, respired 5.2 kcal/m2, and used 1.4 kcal/m2 in production. Crangonyx r. occidentalis energy flow was fairly constant throughout the year. The ecological efficiency of a C. r. occidentalis-predator system was in the range 2–10.5%, the net production efficiency was 21%, and the population growth efficiency was 17% on an annual basis.

Seasonal pattern of energy use, respiration, and nitrogenase activity in root nodules of Myrica gale

1983 ◽  
Vol 61 (11) ◽  
pp. 2937-2942 ◽  
Author(s):  
Christa R. Schwintzer ◽  
John D. Tjepkema
Keyword(s):  
Energy Cost ◽  
Energy Use ◽  
Nitrogenase Activity ◽  
Root Nodules ◽  
Seasonal Pattern ◽  
Uptake Ratio ◽  
Experimental Conditions ◽  
Myrica Gale ◽  
Net Production ◽  
N Requirement

Annual CO2 evolution, H2 evolution, and C2H2 reduction were measured in root nodules from a vigorous Myrica gale stand in a Massachusetts peatland at 3-week intervals in 1980. Nodule activity was approximately the same under the experimental conditions (excised nodules reducing C2H2) as in nature (attached nodules reducing N2) and the CO2 evolution to O2 uptake ratio averaged 1.07. Nitrogenase activity was first detectable in late May, reached its maximum [Formula: see text] in mid-July, and disappeared in late October. The seasonal pattern of CO2 evolution was similar except that it continued at low rates when nitrogenase activity was absent. Hydrogen evolution was barely detectable. The energy cost of nitrogen fixation, expressed as the molar CO2:C2H4 ratio, was relatively low [Formula: see text] throughout the period of substantial nitrogenase activity and had a mean annual value of 4.9. Annual N2 fixation was estimated to be 2.8 g N m−2year−1, contributing about 33% of the annual N requirement measured in 1979. Annual C use by nodules was about 21.0 g C m−2 year−1. If this C were available for additional net production, it would increase it by about 5.5%.

scholarly journals Determination of Deoxynivalenol Biomarkers in Italian Urine Samples

Toxins ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 441 ◽  
Author(s):  
De Santis ◽  
Debegnach ◽  
Miano ◽  
Moretti ◽  
Sonego ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Analytical Approach ◽  
Total Population ◽  
The Elderly ◽  
Urine Samples ◽  
Vulnerable Groups ◽  
Age Group ◽  
Children And Adolescent ◽  
Before And After

Deoxynivalenol (DON) is a mycotoxin mainly produced by Fusarium graminearum that can contaminate cereals and cereal-based foodstuff. Urinary DON levels can be used as biomarker for exposure assessment purposes. This study assessed urinary DON concentrations in Italian volunteers recruited by age group, namely children, adolescents, adults, and the elderly. In addition, vulnerable groups, namely vegetarians and pregnant women, were included in the study. To determine the urinary DON, its glucuronide and de-epoxydated (DOM-1) forms, an indirect analytical approach was used, measuring free DON and total DON (as sum of free and glucuronides forms), before and after enzymatic treatment, respectively. Morning urine samples were collected on two consecutive days, from six different population groups, namely children, adolescent, adults, elderly, vegetarians and pregnant women. Total DON was measured in the 76% of the collected samples with the maximum incidences in children and adolescent age group. Urine samples from children and adolescent also showed the highest total DON levels, up to 17.0 ng/mgcreat. Pregnant women had the lowest positive samples per category (40% for day 1 and 43% for day 2, respectively), low mean levels of total DON (down to 2.84 ng/mgcreat) and median equal to 0 ng/mgcreat. Estimation of DON dietary intake reveals that 7.5% of the total population exceeds the TDI of 1 μg/kg bw/day set for DON, with children showing 40% of individuals surpassing this value (male, day 2).

The Dismantling of the Mental Hospital?

1987 ◽  
Vol 151 (4) ◽  
pp. 479-485 ◽  
Author(s):  
M. Ford ◽  
C. Goddard ◽  
R. Lansdall-Welfare
Keyword(s):  
Mental Hospital ◽  
Total Population ◽  
Resident Population ◽  
Rate Of Decline

Results of the sixth quinquennial survey of the resident population of Glenside Hospital, Bristol, are reported. The total population continues to fall, but the rate of decline has slowed; the implications of this are discussed. Many patients live in an emotionally impoverished state, friendless and rarely leaving the hospital. Few in-patients are employed, even within the hospital. Considerable provision is made, however, for the employment of day-patients. To effectively resettle and support in the community those currently remaining in hospital will require increasingly extensive provision.

scholarly journals Annual variations in fish fecundity

1957 ◽  
Vol 36 (2) ◽  
pp. 377-382 ◽  
Author(s):  
T. B. Bagenal
Keyword(s):  
Fish Species ◽  
Total Population ◽  
Accurate Estimate ◽  
Young Fish ◽  
Important Work ◽  
Annual Variations ◽  
Steady Decrease ◽  
Mean Size ◽  
The Mean ◽  
Hippoglossoides Platessoides

The variation in the fecundity of a fish species from year to year has not received much attention, although the changes in the numbers of young fish in the plankton are well documented for the Plymouth area (Russell 1930–47; Corbin, 1948–51). The most important work considering fecundity fluctuations is that of Simpson (1951) who, working onPlaice, Pleuronectes platessa L., concluded that during 1947,1948 and 1949 there was a steady decrease in the number of eggs laid, this being due to a decrease in the mean size of the spawning fish which he showed to be correlated with the egg numbers. Simpson's interest in the fecundity was to provide a more accurate estimate for determining the number of plaice in the total population from planktonic egg surveys similar to the work of Buchanan-Wollaston (1923). He did not consider in detail whether the fecundity for a given length might change from year to year. It is this problem which will be considered here. Estimates of fecundity of Long Rough Dabs, Hippoglossoides platessoides (Fabr.), will be analysed, and Simpson's Plaice data will also be considered.

Ecological Efficiency of Some Hydrogen Production Processes

2016 ◽  
pp. 127-137
Author(s):  
Lúcia Bollini Braga ◽  
Celso Eduardo Tuna ◽  
Fernando Henrique Mayworm de Araujo ◽  
Lucas Fachini Vane ◽  
Daniel Travieso Pedroso ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Ecological Efficiency ◽  
Production Processes

scholarly journals ASUPAN ENERGI, PROTEIN, DAN STATUS GIZI DENGAN KADAR UREUM PADA PENDERITA PENYAKIT GINJAL KRONIK DENGAN HEMODIALISA

2018 ◽  
Vol 7 (2) ◽  
pp. 164-168
Author(s):  
Sri Era Wahyuni
Keyword(s):  
Nutritional Status ◽  
Energy Intake ◽  
Research Design ◽  
Protein Intake ◽  
Total Population ◽  
Sampling Technique ◽  
Cross Sectional ◽  
Independent Variables ◽  
Relationship Of ◽  
The Relationship

Energy and protein intake decreased menurun (<1600 kkal and  <40 gr)  in patients with CKD RSUD M.Yunus Bengkulu, which can affect the nutritional status of the state can be seen from the LLA.The purpose of this study to examine the relationship of energy intake, protein and nutritional status based on LLA with urea levels in patients with CKD undergoing hemodialysis in hemodialysis installation RSUD dr. M. Yunus Bengkulu in 2013. Type a descriptive analytic study using cross-sectional research design with the independent variables (intake of energy, protein, nutritional status) and the dependent variable (urea levels). Total population of 140 people with 58 sample was taken by purposive sampling technique. The results of this study found that there was no significant correlation between energy intake with urea levels, there was a significant association between the intake of protein with urea levels and no significant correlation between the levels of nutritional status on penderta urem CKD undergoing hemodialysis in hemodialysis Installation RSUD  dr . M. Yunus Bengkulu in 2013.

scholarly journals Digitalization in the Mining Industry

2021 ◽  
pp. 184-192
Author(s):  
O. E. Kalenov
Keyword(s):  
Mining Industry ◽  
Digital Technologies ◽  
Digital Transformation ◽  
Decisive Factor ◽  
Ecological Efficiency ◽  
Mining Companies ◽  
Production Processes ◽  
Advanced Technologies ◽  
Labour Costs ◽  
The World

Competitiveness of mining enterprises is determined, mainly by their productivity and operation superiority. Digitalization becomes a decisive factor, which can provide an opportunity to companies of this sphere to remain competitive in the future. In mining industry passing-over to new, advanced methods of work usually happens more slowly due to the scale and complexity of production processes and considerable costs necessary for re-equipment. That is why certain enterprises of this field use digital technologies without enthusiasm. However, the leading mining companies in the world invest vast funds in development of advanced technologies in power engineering and automation in order to increase mining and ecological efficiency, to cut the volume of hand labour, costs and power expenses. It is obvious that digital technologies can give new opportunities for serious rise in productivity and profit. The article studies key lines in digital transformation at mining enterprises, demonstrates basic advantages and potential threats. The authors analyze both foreign and Russian examples of effective digitalization at enterprises of this sphere.

The Workhouse Population of the Nottingham Union, 1881-1882

2017 ◽  
pp. 66-80 ◽  
Author(s):  
Johanna Purser
Keyword(s):  
Local Politics ◽  
Population Analysis ◽  
Seasonal Pattern ◽  
Good Practice ◽  
Local Economy ◽  
Social Conditions ◽  
Poor Law ◽  
Resident Population ◽  
The Poor ◽  
Using Data

The purpose of this article is to examine and analyse the resident population of the Nottingham Union Workhouse during a 12-month period beginning on Lady Day 1881. Using data drawn from the workhouse admission and discharge registers this study analyses the seasonal pattern of admissions and discharges as revealed by the registers, and also considers how this pattern might be related to the local economy. The Nottingham region had been a beacon of good practice in the treatment of the poor in the years leading up to the Poor Law Amendment Act of 1834, but soon became a centre of resistance to the New Poor Law. Local politics and the textile trade cycle not only prevented the legislation from being fully implemented after 1834, but also dictated the economic and social conditions which prevailed in Nottingham in the later nineteenth century. The population analysis is based not only on the relevant admission and discharge register data, but also includes a study of the workhouse census information for 1881. The incidence of birth in the workhouse is also assessed together with the use made of the workhouse by women for giving birth and 'lying-in'.

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