The importance of feeding status and desiccation rate in successful anhydrobiosis of Panagrolaimus detritophagus

Abstract We examined the effect of nutritional status and desiccation rate on the ability of Panagrolaimus detritophagus to undergo anhydrobiosis, as well as to survive high temperatures in the dried state. Both nutrition and drying rate were found to be important, with starvation and slow drying providing better success at anhydrobiosis. The upper temperature for survival of dried animals in laboratory studies was 80°C. Starved worms recovered from drying more successfully when the starvation period was followed by a smooth, gradual dry period prior to undergoing desiccation. Thus, the ability of these worms to enter and leave anhydrobiosis is dependent on critical stress signals.

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The effect of feeding intensity during the dry period on plasma leptin and time to return to cyclicity in dairy cows

Proceedings of the British Society of Animal Science ◽

10.1017/s1752756200006578 ◽

2002 ◽

Vol 2002 ◽

pp. 1-1 ◽

Cited By ~ 2

Author(s):

K. Holtenius ◽

S. Agenäs ◽

H. Gustafsson ◽

C. Delavaud ◽

Y. Chillard

Keyword(s):

Nutritional Status ◽

Dairy Cows ◽

Body Condition ◽

Reproductive Function ◽

Peptide Hormone ◽

Dry Period ◽

Feeding Intensity ◽

Plasma Leptin ◽

Different Levels ◽

Effect Of Feeding

Much evidence has accumulated showing that female reproductive functions are disrupted when changes in nutritional status take place in both over- and undernutrition. The peptide hormone leptin is considered a possible link between nutrition and reproduction. One objective with the present study was to investigate how different levels of feed intake during the dry period, thereby creating differences in body condition at parturition, affected the plasma leptin concentration and the reproductive function after parturition.

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Persistent, vertical-migration rhythms in benthic microflora.: II. Field and Laboratory Studies On Diatoms From The Banks Of The River Avon

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400017641 ◽

1966 ◽

Vol 46 (1) ◽

pp. 191-214 ◽

Cited By ~ 92

Author(s):

F. E. Round ◽

J. D. Palmer

Keyword(s):

High Temperatures ◽

Vertical Migration ◽

Laboratory Experiments ◽

Biological Clock ◽

Diatom Species ◽

Laboratory Studies ◽

Natural Conditions ◽

Constant Illumination ◽

Different Temperatures ◽

Clock Hypothesis

The vertical migration of two Euglena species and several diatom species into and out of the sediment on the banks of the River Avon has been studied under natural conditions. All species have been shown to migrate vertically upwards when exposed during daylight. Tidal flooding of the sediment is generally preceded by re-burrowing of the algae beneath the surface. Methods have been devised to follow these migrations in both the field and laboratory. Laboratory experiments show that these migrations are rhythmic, continuing under constant illumination and temperature and removed from tidal influence. The effect of three different temperatures and three different light intensities has been investigated. Transfer from low to high temperatures has been shown to reset the phase of the rhythm. The results are discussed in relation to other work and to the ‘biological clock’ hypothesis.

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Field and laboratory studies of net-spinning activity by Hydropsyche larvae (Trichoptera: Hydropsychidae)

Canadian Journal of Zoology ◽

10.1139/z80-276 ◽

1980 ◽

Vol 58 (11) ◽

pp. 2006-2014 ◽

Cited By ~ 25

Author(s):

Randall L. Fuller ◽

Rosemary J. Mackay

Keyword(s):

High Temperatures ◽

Current Velocity ◽

The Other ◽

Laboratory Studies

Net-spinning activity of third, fourth, and fifth instars of Hydropsyche betteni, H. slossonae, and H. sparna was observed at three different experimental temperatures and current speeds. The upstream species, H. slossonae, was intolerant of high temperatures (20 °C) while the other species were more tolerant. Colder temperatures (5 and 14 °C) decreased net spinning of all species and instars. The slowest current velocity (10 cm/s) had little effect on third-instar net spinning but reduced that of fifth instars. Faster currents (20 and 40 cm/s) raised the percentages of fourth and fifth instars producing nets but did not change third-instar net spinning.Experiments investigating the absence of nets in the field during winter showed that net spinning was reduced when substrates developed thick accumulations of diatoms and detritus (ADD) and that larvae emigrated from low ADD areas, apparently in favor of high ADD areas. Winter photoperiods also decreased net spinning. Resumption of net spinning in spring may be triggered by scouring of ADD from substrates during snowmelt and by longer day lengths.

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Effects of animal size and nutritional status on the RNA/DNA ratio in different tissues of the green-lipped mussel Perna viridis

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315411001573 ◽

2011 ◽

Vol 93 (1) ◽

pp. 217-225 ◽

Cited By ~ 5

Author(s):

Jamius W.Y. Yeung ◽

Kenneth M.Y. Leung

Keyword(s):

Nutritional Status ◽

Adductor Muscle ◽

Health Condition ◽

Tissue Type ◽

Perna Viridis ◽

Laboratory Studies ◽

Short Term ◽

General Health Condition ◽

Animal Size ◽

Hong Kong Waters

This study aimed to examine the responses of RNA/DNA ratio in Perna viridis under different nutritional status via both field and laboratory studies, and hence evaluate the usefulness of this ratio as a rapid growth biomarker in the mussels. First, the effects of size (small: 30–40 mm; medium: 40–50 mm; large: >50 mm) and tissue type (adductor muscle, foot, gill and hepatopancreas) on the RNA/DNA ratio were investigated in P. viridis collected from three different sites with different degrees of eutrophication in Hong Kong waters. Across all sizes, the mussels collected from a fairly ‘eutrophic’ mariculture zone had significantly higher RNA/DNA ratios in their gills than those from the other two relatively clean sites. The RNA/DNA ratio in small mussels was generally higher than in medium and large individuals, though such a size effect significantly interacted with tissue type and site. Second, we conducted a 10-day comparative laboratory study to elucidate the influence of starvation and feeding on the RNA/DNA ratio in the mussels. We observed that both hepatopancreas and foot muscle generally exhibited significant and rapid response to such a short-term starvation or food addition. The present results confirmed that the RNA/DNA ratio in P. viridis is a sensitive biomarker to gauge their growth and general health condition in accordance with food availability and/or eutrophication condition.

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Effects of starvation on circadian variations of plasma TSH in rats

Acta Endocrinologica ◽

10.1530/acta.0.1010403 ◽

1982 ◽

Vol 101 (3) ◽

pp. 403-407 ◽

Cited By ~ 6

Author(s):

J. N. Hugues ◽

A. Reinberg ◽

D. Jordan ◽

J. Sebaoun ◽

E. Modigliani ◽

...

Keyword(s):

Nutritional Status ◽

Starvation Period ◽

Circadian Pattern ◽

Circadian Variations ◽

Tsh Secretion ◽

Ad Libitum ◽

Diurnal Fluctuations ◽

The Relationship ◽

Tsh Levels

Abstract. Diurnal fluctuations of plasma TSH were investigated in ad libitum fed rats as well as after a 3 day starvation period in order to study the relationship between the circadian pattern of TSH secretion and nutritional status. Our study showed the persistence of a circadian TSH rhythm after a 3 day starvation without any change in the amplitude of plasma TSH variations. However, the 24 h average plasma TSH levels were significantly lower. A suggestive acrophase occurred at the same period of the day in starved and fed rats. Our results suggest that the control of plasma TSH concentrations and nycthemeral rhythm are not closely related and may even possibly be independent of one another.

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EUCALYPTUS LOGS DRYING AT HIGH TEMPERATURES

Revista Árvore ◽

10.1590/1806-90882017000200007 ◽

2017 ◽

Vol 41 (2) ◽

Author(s):

Aylson Costa Oliveira ◽

Bárbara Luísa Corradi Pereira ◽

Angélica de Cássia Oliveira Carneiro ◽

Lucas de Freitas Fialho ◽

Clarissa Gusmão Figueiró ◽

...

Keyword(s):

High Temperatures ◽

Water Loss ◽

Total Loss ◽

Drying Rate ◽

Eucalyptus Urophylla ◽

Drying Process ◽

Forced Air ◽

Air Circulation ◽

Diameter Classes

ABSTRACT The objective of this work was to evaluate the drying speed of Eucalyptus urophylla logs in high temperatures and the influence of the presence or absence of bark and also the diameter of the log in the drying rate. Eucalyptus logs 60 cm long were divided into three diameter classes: 8-12 cm; 12,1-16 cm and 16,1-20 cm. The logs were dried in a heater with forced air circulation, in the presence or absence of bark in five temperatures: 50, 75, 100, 125 and 150ºC. The mass and the initial moisture were determined from each log and the water loss was kept up with periodic weightings, closing the drying process when the logs reached 20% moisture. The drying rate of the logs was calculated using the ratio between the total loss of moisture and the time in hours in order to reach the established moisture. It was concluded that the increase in temperature promotes the raise of the drying ratio, as being higher for smaller logs in relation to bigger ones and in addition to this, the bark effect was not significant in the drying of eucalyptus logs above 100ºC. It was also concluded that the best conditions for the operation of artificial dryers for Eucalyptus logs containing bark and separated in diameter classes would be at 125ºC.

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Practical guidelines for postmortem examination and tissue sampling of cetaceans for ecotoxicological purposes

J. Cetacean Res. Manage. ◽

10.47536/jcrm.v1i1.256 ◽

1999 ◽

pp. 43-45

Author(s):

B. Clausen

Keyword(s):

Nutritional Status ◽

Marine Mammals ◽

Postmortem Examination ◽

Biological Data ◽

Tissue Sampling ◽

Pathological Changes ◽

Laboratory Studies ◽

Practical Guidelines ◽

Possible Cause ◽

Postmortem Examinations

Postmortem examinations of marine mammals are undertaken for a number of reasons, inter alia: to determine the possible cause of death; to obtain evidence of diseases or pathological changes; and to collect tissue and other samples (e.g. blood and organs) for further research. The latter can provide material for laboratory studies for a variety of subjects including toxicology, immunology, virology, parasitology and histopathology. The collection of associated biological data such as sex, age, length and nutritional status from each specimen is an essential part of any postmortem examination. Without such data it is very difficult if not impossible to interpret the results of the aforementioned studies.

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Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

International Astronomical Union Colloquium ◽

10.1017/s025292110001469x ◽

1997 ◽

Vol 161 ◽

pp. 179-187

Author(s):

Clifford N. Matthews ◽

Rose A. Pesce-Rodriguez ◽

Shirley A. Liebman

Keyword(s):

Amino Acids ◽

Solar System ◽

Hydrogen Cyanide ◽

Nitrogen Heterocycles ◽

Laboratory Studies ◽

Heterogeneous Solids ◽

The Many ◽

Comet Halley ◽

The Impact ◽

By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

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In situ REM imaging of surface processes on ceramic bulk crystals from 300 to 1670 K in a conventional TEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087616 ◽

1991 ◽

Vol 49 ◽

pp. 660-661

Author(s):

Z. L. Wang ◽

J. Bentley

Keyword(s):

High Temperatures ◽

Image Resolution ◽

Atomic Processes ◽

Crystal Surfaces ◽

Beam Radiation ◽

Surface Areas ◽

Transmission Electron ◽

Reflection Electron Microscopy ◽

Gas Reactions

Studying the behavior of surfaces at high temperatures is of great importance for understanding the properties of ceramics and associated surface-gas reactions. Atomic processes occurring on bulk crystal surfaces at high temperatures can be recorded by reflection electron microscopy (REM) in a conventional transmission electron microscope (TEM) with relatively high resolution, because REM is especially sensitive to atomic-height steps.Improved REM image resolution with a FEG: Cleaved surfaces of a-alumina (012) exhibit atomic flatness with steps of height about 5 Å, determined by reference to a screw (or near screw) dislocation with a presumed Burgers vector of b = (1/3)<012> (see Fig. 1). Steps of heights less than about 0.8 Å can be clearly resolved only with a field emission gun (FEG) (Fig. 2). The small steps are formed by the surface oscillating between the closely packed O and Al stacking layers. The bands of dark contrast (Fig. 2b) are the result of beam radiation damage to surface areas initially terminated with O ions.

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