Investigation of the relationship between invertebrate predation and biochemical composition, energy content, spicule armament and toxicity of benthic sponges at McMurdo Sound, Antarctica

1987 ◽  
Vol 94 (3) ◽  
pp. 479-487 ◽  
Author(s):  
J. B. McClintock
Keyword(s):  
Biochemical Composition ◽  
Energy Content ◽  
Invertebrate Predation ◽  
Mcmurdo Sound ◽  
The Relationship

scholarly journals DIGESTIBLE ENERGY IN FORAGE BYIN VIVOANDIN VITROASSAYS

1970 ◽  
Vol 50 (3) ◽  
pp. 557-562 ◽  
Author(s):  
J. E. TROELSEN
Keyword(s):  
Energy Analysis ◽  
Energy Content ◽  
In Vitro Assay ◽  
Pure Species ◽  
Vitro Assay ◽  
Digestible Energy ◽  
The Relationship ◽  
Cattle And Sheep

Forage of six pure species was harvested for hay at several maturity stages during four years. The digestible energy content of 102 different lots of hay was determined by feeding to four groups of sheep during the same period, and by in vitro digestions and energy analysis of the undigested residues. The relationship between digestible energy content assayed by the two methods was highly significant (r = 0.85) and did not differ between years and species. Exclusion from regression of the hays containing less than 2 or more than 3 digestible kcal/g revealed that the in vitro assay could reproduce the in vivo digestible energy value with a standard deviation of 0.31 in over 70% of the hays. This represented the maturity and quality range of forage commonly fed to cattle and sheep. The in vitro assay therefore appeared promising for commercial quality determinations.

scholarly journals Tests for coronal electron temperature signatures in suprathermal electron populations at 1 AU

2017 ◽  
Vol 35 (6) ◽  
pp. 1275-1291 ◽  
Author(s):  
Allan R. Macneil ◽  
Christopher J. Owen ◽  
Robert T. Wicks
Keyword(s):  
Solar Wind ◽  
Electron Temperature ◽  
Energy Content ◽  
The Sun ◽  
Particle Interactions ◽  
Core Electron ◽  
Suprathermal Electron ◽  
Electron Distributions ◽  
The Relationship ◽  
Coronal Electron

Abstract. The development of knowledge of how the coronal origin of the solar wind affects its in situ properties is one of the keys to understanding the relationship between the Sun and the heliosphere. In this paper, we analyse ACE/SWICS and WIND/3DP data spanning  > 12 years, and test properties of solar wind suprathermal electron distributions for the presence of signatures of the coronal temperature at their origin which may remain at 1 AU. In particular we re-examine a previous suggestion that these properties correlate with the oxygen charge state ratio O7+ ∕ O6+, an established proxy for coronal electron temperature. We find only a very weak but variable correlation between measures of suprathermal electron energy content and O7+ ∕ O6+. The weak nature of the correlation leads us to conclude, in contrast to earlier results, that an initial relationship with core electron temperature has the possibility to exist in the corona, but that in most cases no strong signatures remain in the suprathermal electron distributions at 1 AU. It cannot yet be confirmed whether this is due to the effects of coronal conditions on the establishment of this relationship or due to the altering of the electron distributions by processing during transport in the solar wind en route to 1 AU. Contrasting results for the halo and strahl population favours the latter interpretation. Confirmation of this will be possible using Solar Orbiter data (cruise and nominal mission phase) to test whether the weakness of the relationship persists over a range of heliocentric distances. If the correlation is found to strengthen when closer to the Sun, then this would indicate an initial relationship which is being degraded, perhaps by wave–particle interactions, en route to the observer.

The relationship between digestibility or energy losses as methane and metabolisable energy content of whole crop wheat

1996 ◽  
Vol 1996 ◽  
pp. 41-41
Author(s):  
A.T. Adesogan ◽  
E. Owen ◽  
D.I. Givens
Keyword(s):  
Organic Matter ◽  
Energy Content ◽  
Organic Matter Content ◽  
Matter Content ◽  
Energy Losses ◽  
Digestible Organic Matter ◽  
Metabolisable Energy ◽  
The Cost ◽  
The Relationship

Estimates of the metabolisable energy (ME) content of whole crop wheat (WCW) derived using measured energy losses as methane (ELMm) are lacking due to the cost of measuring ELMm. Published ME values of WCW are largely calculated using predicted energy losses as methane (ELMp, Blaxter and Clapperton, 1965) or digestible organic matter content (DOMD) in vivo. However, there appears to be no published information about the accuracy with which DOMD in vivo or ELMp predicts the ME content of WCW. Therefore, this study assessed the validity of such ME predictions by comparing them with ME contents calculated using ELMm.

scholarly journals Factors affecting biochemical composition of seston in an eutrophic reservoir (Pampulha Reservoir, Belo Horizonte, MG

2000 ◽  
Vol 60 (1) ◽  
pp. 63-71 ◽  
Author(s):  
I. G. BOËCHAT ◽  
A. GIANI
Keyword(s):  
Seasonal Changes ◽  
Biochemical Composition ◽  
Abiotic Factors ◽  
Eutrophic Lake ◽  
Phytoplankton Assemblages ◽  
Factors Affecting ◽  
Physical Chemical ◽  
Algal Groups ◽  
Belo Horizonte ◽  
The Relationship

Sestonic biochemical composition (lipids, proteins and carbohydrates) may change with varying environmental fluctuations. These changes and the effects in the nutritional status of algae consists of an actual increasing source of interest. The aims of this work were to establish the relationship between biochemical composition of seston and 1) a range of physical, chemical and climatological factors, and 2) the natural fluctuation in the species composition in phytoplankton assemblages of the Pampulha Reservoir, an urban eutrophic lake located in Belo Horizonte, MG. Seasonal changes in the biochemical composition were observed in this study. None of the considered abiotic factors alone seem to affect the biochemical composition. So the effects could only be understood by interactions among different environmental factors. On the other hand, the dominant algal groups probably have some influence in the observed changes in biochemical composition of seston.

scholarly journals The electronic structure of some polyenes and aromatic molecules I–The nature of the links by the method of molecular orbitals

1937 ◽  
Vol 158 (894) ◽  
pp. 280-296 ◽  
Keyword(s):  
Electronic Structure ◽  
Organic Molecules ◽  
Characteristic Property ◽  
Energy Content ◽  
Empirical Relation ◽  
Resonance Energy ◽  
Canonical Structure ◽  
Aromatic Molecules ◽  
The Individual ◽  
The Relationship

The characteristic property which some molecules have of trans­mitting influences from one part to another is an indication that the electrons constituting the bonds cannot be segregated into closed localized pairs. This feature is represented in the Pauling method by the super­ position of a number of canonical structures, each of which corresponds to a chemical picture of localized bonds. The state of the molecule has properties which are different from those of the individual canonical structures, but can be defined or interpreted in terms of a set of them. The energy of the lowest or normal state is usually lower than that of any one canonical structure, even than that which would appear from the orthodox method of drawing bonds to be the most stable. The amount by which the energy sinks as a result of the superposition has been called resonance energy by Pauling, and numerical estimates of its value have been made for a large number of organic molecules. In calculating this energy change, however, no account seems to have been taken of the change in the lengths of the links which may be caused by the interaction of the electrons. Links are regarded as single or double, and the appropriate energy content calculated as though they were isolated single or double links, whereas the interaction between adjoining links may result in a length and an energy of link, to which the description single or double is no longer appropriate. Pauling has recently discussed the relationship between the nature and the lengths of links in typical organic molecules. Taking the known lengths of links in ethylene, benzene, graphite, and ethane, and the frac­tional order of their links (as two, three-halves, four-thirds, and unity) derived from the coefficients which occur in the linear sum of canonical structures, Pauling has derived an empirical relation between them. From it he deduces in other cases the extent to which the double-bonded character enters into other links. Pauling’s method will be made more precise in a paper which follows this.

A note on the relationship between the digestible dry matter and the digestible energy content of ruminant diets

1961 ◽  
Vol 1 (1) ◽  
pp. 24 ◽  
Author(s):  
RJ Moir
Keyword(s):  
Dry Matter ◽  
Energy Content ◽  
Accurate Description ◽  
Digestible Energy ◽  
Dry Matter Digestibility ◽  
Wide Range ◽  
Ruminant Diets ◽  
The Relationship

The digestible energy content (y, in Calories per gram) of a wide range of foodstuffs for ruminants may be accurately estimated from the dry matter digestibility (x per cent) by the regression y = 0.0467 x - 0.158 (r = 0.998). It follows that dry matter digestibility itself is a simple and accurate description of the digestible energv content of foodstuffs for ruminants.

scholarly journals ALTERATIONS IN BIOCHEMICAL COMPOSITION AND RIBONUCLEIC ACID METABOLISM INDUCED IN RAT LIVER BY CORTISONE

1956 ◽  
Vol 2 (3) ◽  
pp. 331-350 ◽  
Author(s):  
Charles Upton Lowe ◽  
Royden N. Rand
Keyword(s):  
Rat Liver ◽  
Biochemical Composition ◽  
Microsomal Fraction ◽  
Acid Metabolism ◽  
Chemical Constituents ◽  
Differential Centrifugation ◽  
Sucrose Solutions ◽  
The Relationship

An investigation of the effect of cortisone administration upon the chemical composition of intracellular particulates of rat liver has been made. Livers were homogenized in 0.25 M sucrose solutions and submitted to differential centrifugation. Five fractions were prepared: mitochondria (Mit), microsomes (Mi), ultracentrifugable (U), non-sedimentable (S), and nuclear (Nuc). Measurement was made of total and polymerized RNA, nitrogen, lipide P, and uptake of P32 by the RNA of each fraction. The following observations were made:— Cortisone administration caused a fall in concentration in all measured constituents except glycogen. On a per liver basis, however, total liver RNA was unchanged in amount; nitrogen content of Mi fell and that of S increased; the lipide P of Mit and Mi also decreased. The biochemical composition of a statistical mitochondrion was significantly altered; in contrast, the microsomal fraction decreased in amount, but the relationship between the chemical constituents was unchanged. When polymerized RNA was sought by a process involving precipitation from ethanol at 20°C., none was found in the Mit of cortisone livers and the amount in Mi was much less than found in the normal. When, however, precipitation was conducted at 4°C., yields of polymerized RNA in all fractions after cortisone were equal to or greater than those found in the normal. Furthermore, incubation of mixtures of homogenates from normal and cortisone livers resulted in loss of warm precipitable RNA. These data strongly suggest the presence of an enzyme in cortisone livers which upon incubation with normal livers made preparation of polymerized RNA virtually impossible by use of the warm method. This agent, thought to operate in vivo and in vitro, was not present in significant amounts in normal livers, since incubation in this instance had no effect upon the amount of polymerized RNA. Mit from cortisone livers obtained by the cold technique had a significantly decreased rate of incorporation of P32 even though the yield of RNA from this fraction was increased. To reconcile these observations, it was proposed that under the influence of cortisone a variant of normal RNA is synthesized or normal RNA is converted to this variant. This "new" RNA has new solubility properties, a new rate of incorporation of P32, and conceivably it cannot act as a template for normal protein synthesis.

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