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21.
Temperature and metabolic rate in sedentary fish from the Antarctic,North Sea and Indo-West Pacific Ocean 总被引:2,自引:0,他引:2
Resting metabolic rate
was measured in demersal stages of the teleostNotothenia neglecta Nybelin from the South Orkney Islands, Antarctica, from 1985 to 1987. The relationship between
and body mass (Mb) conformed to the general relationship
, wherea is a proportionality constant andb is the scaling exponent.
(mg O2 h–1) was found to scale toMb
(0.82±0.011) in the summer (November to April, 1.6 to 1 850 g,n=56) and toMb
(0.76±0.013) in the winter (May to October, 0.9 to 1 850 g,n=57) (values ofb are means ± SD). Although the scaling exponents were significantly different (P<0.01),
was similar in the juvenile stages of summer- and winter-caught fish matched for body mass. The effects of activity on oxygen consumption was studied using a Brett respirometer. Adult stages had a factorial aerobic scope for activity
of 5.7, which is similar to that reported for demersal fish from temperate latitudes. The effects of temperature on resting metabolism was investigated in fish with similar sedentary lifestyles from the North Sea (Agonus cataphractus andMyoxocephalus scorpius) and the Indo-West Pacific (Paracirrhites forsteri, P. arcatus, Neocirrhites armatus andExallias brevis). Extrapolated values of
for the tropical species approached zero at 5 to 10°C. For a standard 50 g fish,
for the tropical species at 25°C was in the range 3.4 to 4.4 mg O2 h–1, compared with 1.3 mg O2 h–1 forNotothenia neglecta at its acclimation temperature. Thus, the maximum metabolic rate of sedentary tropical species at 24°C is likely to be 2 to 4 times higher than inN. neglecta at 0°C. This suggests that the energy available for sustained activity
is significantly lower in cold- than in warm-water fish. 相似文献
22.
Protein, lipid, phosphorus, and organic carbon contents, as well as electron transport system (ETS) activity, lactatedehydrogenase activity, and gut evacuation rate, were measured in four interzonal species of Pacific copepods:Calanus australis, C. pacificus, Eucalanus inermis, andE. elongatus f.hyalinus, collected at the upwelling areas off Peru (8°S) and California (27°N), and in the middle of the North Pacific (30°N), from February to April 1987. The two Eucalanidae species —E. inermis andE. elongatus — have distinctive biochemical and elemental body composition and rates of main physiological processes. Relative protein, lipid, phosphorus, and organic carbon contents (µg mg–1 wet weight) in these species were, respectively, ca. 1/7 to 1/10, 1/5 to 1/20, 1/5 to 1/10, and 1/5 those inCalanus spp. Likewise, oxygen uptake rate per unit of wet weight (based on ETS activity) inE. inermis andE. elongatus was 5 to 10% of that in calanids; a similar difference was found in phosphorus excretion rate. In addition, gut evacuation rates inE. inermis andE. elongatus were ca. one-fifth of those inCalanus spp. Based on these data, we considered the eucalanids as belonging to a distinctive physiological group, figuratively named jelly-body copepods. In contrast with calanids, active lactatedehydrogenase has been found in the bodies ofE. inermis andE. elongatus, apparently allowing them to survive for a long time in layers of extremely low oxygen content (<0.2 ml l–1). The adaptive value of physiological features in these eucalanids and typical calanids is compared. 相似文献
23.
A Barba M A Camara S Navarro Garcia C Sanchez-Fresneda N Lopez de Hierro A Acebes 《Journal of environmental science and health. Part. B》1991,26(3):323-332
Residues of Bromopropylate were determine in artichokes, strawberries and beans after foliar spray of acaricide at two rates. The rates used were 1 g/l formulated product (normal recommended) and 1.5 g/l. The residue levels of bromopropylate in the three crops after 14 days were lower than 0.7 ppm and did not exceed the Maximum Residual Level (MRL) recommended by FAO. In the artichokes and strawberries, the total concentration of residues decreased by 50% of the initial level after 2-3 days. Only trace levels of the bromopropylate residues (less than 0.01 ppm) were detected in the "hearts" of the artichokes. Bromopropylate residues in the green beans were also less than 0.8 ppm after the first day of foliar spraying. The kinetic of degradation occurred in two different steps. In the first step (4-6 days) the dissipation of bromopropylate was faster whereas in the second step (7-14 days) the loss of residues was much slower. 相似文献
24.
25.
Pomonis A 《Disasters》1990,14(2):89-114
The 1988 earthquake in Armenia was the most serious seismic disaster since the 1976 earthquake in Tangshan, China. At least 25,000 people lost their lives in a tremor of moderate magnitude and the USSR suffered a loss of more than 2.5 per cent of 1988's GDP. Research at the Martin Centre on the effects of earthquakes on human lives has shown an increase in global earthquake mortality rate, despite the well known improvements in some countries. The Armenian disaster was a warning to all of us concerned with natural or man-made disasters. Areas of potential high hazard are pointed out for the sub-Caucasian region. Construction practices similar to those in Armenia are certainly found in many other parts of the world, with some regional variations, and the fast assimilation of the lessons is an important target. The structural characteristics of all the residential building types existing in the affected area are presented in terms of their seismic vulnerability. Vulnerable points are discussed with a view to low cost interventions that will drastically improve the seismic safety of new buildings. 相似文献
26.
Ornas AH 《Disasters》1990,14(2):115-122
The most vulnerable people in Third World countries are often accused of destroying forests and fragile ecosystems and of practising destructive forms of agriculture and animal husbandry. The key to environmental sustainability, however, lies in more reliable production and food security at the local level. This article focuses on individual and household security amongst dryland herders in East Africa. The most crucial aspect of pastoral viability is the maintenance of a balance between family herd and size of household. Risk-spreading, through dependence on relatives, the borrowing of animals, redistribution through marriage etc. is a general principle of social behaviour amongst these peoples. Consideration of local-level security, furthermore, reveals the connection between ecological stress and political conflict. Only by establishing secure access to food for individuals and families can sustainable development and political security, not only at the local but also at the national and international levels, be achieved. 相似文献
27.
28.
A. Raman 《Die Naturwissenschaften》1967,54(21):560-560
29.
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