Showing papers on "Energy source published in 1971"

Nutrient requirements for the culture of preimplantation embryos in vitro

Abstract: All normal mouse embryos develop from the pronuclear stage to blastocysts when cultured in a simple chemically defined medium and a high proportion of these develop into normal mice if introduced into the uteri of pseudopregnant females. The medium should have an osmolarity between 240 and 310 milliosmols and a pH of about 7.2. Some oxygen should be present but the partial pressure should be less than 76 mm Hg. Calcium and bicarbonate ions are essential but there does not appear to be a requirement for amino nitrogen. Pyruvate is the only essential energy source but it inhibits development at higher concentrations.

Ecological Implications of dividing Plants into Groups with Distinct Photosynthetic Production Capacities

Abstract: Publisher Summary This chapter discusses the ecological implications of dividing plants in groups with distinct photosynthetic production capacities. The productivity of photosynthetic organisms is a fundamental factor in ecological relationships. It is observed that data on plant anatomy, plant physiology, and plant biochemistry have largely converged with the recognition of distinct groups of plants with several distinct characteristics including photosynthetic production capacity. One of the distinguishing characteristics of each plant group is the rate of net photosynthesis which in one major group of plants is two to threefold higher than the second major group of plants. This chapter describes the data which supports the concept of dividing plants in distinct groups in order to analyze some ecological implications and consequences of a particular division. The chapter also describes various criteria's based on which the plants are divided in distinct group. These include anatomical, physiological, and biochemical criteria's. In specific, the chapter considers photosynthetic capacity as a dominating factor in ecology. It states that solar energy is the major energy source and a plant which can add energy two to three times faster into an ecosystem than another plant must be considered when explaining or studying that ecosystem.

The human alveolar macrophage: isolation, cultivation in vitro, and studies of morphologic and functional characteristics

Abstract: Human alveolar macrophages were lavaged from surgically resected lungs and from lungs of normal subjects. Macrophages that had been purified by glass adherence were maintained in tissue culture for as long as 54 days. After 3-4 wk in vitro they underwent transformation into multinucleated giant cells. These aged cells had more than 30 times the phagocytic capacity that the same group of cells had had after 1 day in vitro. Phagocytosis of heat-killed Candida albicans was inhibited by iodoacetate, sodium fluoride, potassium cyanide, and low partial pressures of oxygen, suggesting that these cells require both oxidative and glycolytic energy sources for maximal particle ingestion. Alveolar macrophages and monocyte-derived macrophages killed Listeria monocytogenes with similar efficiency, but neutrophils were more efficient than either of the other cell types. Bacterial killing is probably not dependent upon myeloperoxidase in the monocyte-derived macrophage or in the alveolar macrophage since histochemical stains for peroxidase do not stain either cell type. C. albicans blastospores, which are killed by neutrophils and monocytes that contain myeloperoxidase, were not killed by human alveolar macrophages during the 4 hr of observation. Large cells with supernormal phagocytic capacity were recovered from patients with postobstructive pheumonia and from one patient with recurrent bacterial pneumonia, indicating that macrophage function can be altered in certain disease states. Human alveolar macrophages are unique human phagocytes in their dependence on an oxygen tension greater than 25 mm HG for maximal phagocytosis. Carbon dioxide tensions as high as 70 mm Hg did not alter phagocytosis when the pH of the medium was held constant. These data suggest that the increased susceptibility to pneumonia of patients with chronic bronchitis or atelectasis may be in part related to suboptimal phagocytosis by macrophages in areas of the lung with depressed oxygen tension.

Inactivation of fructose-1,6-diphosphatase by glucose in yeast.

Abstract: Fructose-1,6-diphosphatase was derepressed in Saccharomyces cerevisiae by incubation in media containing non-sugar carbon sources. Addition of glucose to a derepressed culture led to a rapid loss of the measurable activity of the enzyme. Fructose and mannose also produced inactivation, but 2-deoxyglucose was ineffective. Experiments with cycloheximide indicated that the inactivation does not require protein synthesis. It was also shown that the process is not energy-dependent. The reappearance of the enzyme was dependent on an energy source and was prevented by cycloheximide. These results suggest that fructose diphosphatase inactivation is irreversible and that reappearance of enzyme activity implies de novo synthesis. Screening of different genera of yeasts has shown that the inactivation of fructose diphosphatase is a relatively widespread phenomenon.

Fossil Fuels as a Source of Mercury Pollution

Abstract: The upper limit of the quantity of mercury released by weathering processes is approximately 230 metric tons per year. The quantity of mercury released by burning of coal is estimated to be of the order of 3000 tons per year, a quantity comparable to that emitted as waste from industrial processes.

The Amino Acid-fermenting Clostridia

Abstract: Summary: Representative strains of 30 named species of clostridia were tested for their ability to grow in a semidefined medium containing either 1 % (w/v) glucose or 3 % (w/v) acid-hydrolysed casein as an energy source. Strains from 15 species were selected empirically as amino acid-fermenting types by comparing growth in the two media. After growth in 3 % casein hydrolysate medium the organisms were removed and their amino acid utilization determined by examining the culture supernatants. The organisms were then divided into four main groups. The characteristic features of each group are as follows: group I, the utilization of proline with the production of δ-amino valeric acid; group II, mainly arginine and/or glycine utilized; group III, the utilization of glutamic acid, serine and histidine; group IV, serine and threonine utilized. Possible implications of these findings for the taxonomy of clostridia are discussed.

Liquid bridges between cylinders, in a torus, and between spheres

Abstract: Recently, there has been a revival of interest in the classical problems concerning the configuration of a mass of liquid which bridges a gap between solid surface, being supported by capillary attraction. These liquid bridges are concepts in theories of oil recovery from porous media, adsorption hysteresis in porous adsorbents, capillary condensation, particle sedimentation, soil properties, and space exploration. The stability of a capillary liquid bridge of given volume between 2 small, solid, equal, separated spheres is investigated by formulating and treating a minimum energy problem in the calculus of variations and by experiment. A conjecture is made that in the case of 2 solutions, one and only one is minimizing, and that the case of one solution represents the limiting stable bridge. This theory agrees accurately with the stability experiments. Furthermore, it is possible to predict the cohesive force. For the case of spheres in contact, the theory presented is in agreement with some experimental work and also with the theory of Fisher and calculations of cohesive force based on Melrose and Wallick's solution to the bridge problem. For the case of separated spheres, the agreement with the only available experimental data is excellent except for close separations. (18more » refs.)« less

The Spectral Reflectance of Natural Surfaces

Abstract: The amount of solar energy reflected from various soils and types of vegetation has been measured as a function of sun elevation in six different wavelength ranges in the ultraviolet, visible and near-infrared regions of the spectrum. It is shown that there is a significant dependence of reflectance on both wavelength and elevation of the sun for all surfaces for which measurements were made.

Spectral studies of tropospheric wave disturbances in the tropical western Pacific

Abstract: Tropospheric wave disturbances in the tropical western Pacific have been subjected to intensive analysis during three separate seasons. These all show evidence of spectral peaks in the 4- to 5-day range and at periods longer than 10 days. In this review I attempt to synthesize the results for these three seasons, together with the analysis of a fourth season, into a tentative description of the various types of wave disturbances in this region. The conclusions are outlined below. It appears that there are two types of tropical disturbances that contribute to the 4- to 5-day peaks: synoptic-scale, westward-propagating waves with phase speeds on the order of 6-7 degrees per day, and planetary-scale equatorial waves that extend into the lower stratosphere. There are also one or more wave types associated with the low-frequency spectral peaks. All the tropical waves exhibit a similar vertical structure, with a phase reversal in the wind field between upper and lower troposphere. There are warm temperature anomalies at 300 mb, above the low-level troughs, in qualitative agreement with the thermal-wind equation. These warm anomalies coincide with the regions of maximum rising motion. As distinguished from tropical waves, the subtropical disturbances do not exhibit a phase reversal in the wind field between upper and lower tropospheric levels. The troughs of these waves appear to be colder than their surroundings at 300 mb. The available potential energy the tropical waves derive from condensation heating is immediately converted into kinetic energy by the synoptic-scale divergent wind field. This appears to be the dominant energy source for these waves. The leakage of wave energy upward through the tropopause appears to be at least an order of magnitude smaller than the rate of energy generation. The spectral results indicate that most of the synoptic-scale mass convergence into regions of disturbed weather takes place above the subcloud layer. Although the vertical distribution of latent heat release displays the same gross features in different regions, a simple linear proportionality between boundary-layer convergence and condensation heating (as is usually assumed in the CISK hypothesis) does not appear to exist.

Biochemistry and methodology of lipids

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The Effects of Two Acute Stresses on the Arthropod Component of an Experimental Grassland Ecosystem.

Abstract: The effects of two acute stresses, mowing and burning, on the arthropod component of an experimental grassland ecosystem were investigated. Oats (Avena sativa L.) were planted in two comparable and adjacent 1-acre areas. Midway in the growing season (July), one area was mowed and the other areas was both mowed and burned. Density and biomass were used to measure the effects of both stresses on the total arthropod community, while species diversity and equitability were used to analyze the species composition and apportionment of the Coleoptera. Effects of mowing on arthropod density and biomass appeared to be relatively brief (2 weeks) as compared with those of burning (3 months). This difference was attributed to a shift from live primary producer energy to detritus in the mowed area, as compared to the almost complete destruction of the energy source in the burned area. Coleoptera species/area diversity was significantly lower (P < 0.01) in the burned area. This was attributed to a greater energy supply and a larger number of ecological niches in the unburned grid. Margalef's species diversity, D = (S-1)/1nN, for the total Coleoptera community was significantly reduced (P < 0.05) in response to the fire. When analyzed by trophic levels on a long-term basis, herbivorous Coleoptera species diversity was significantly reduced (P < 0.01), whereas that of the carnivorous Coleoptera was not measurably affected. Herbivorous Coleoptera equitability values, in response to mowing, exhibited a brief increase before returning to the premow level. In response to burning, however, herbivorous Coleoptera equitability values remained higher than those in the unburned area, indicating a longterm limitation of resources. Carnivore equitability values did not exhibit a long-term increase in response to the fire stress. Coleoptera responses to fire revealed that biomass, species/area diversity, and primary consumer species diversity and equitability were the most sensitive indicators for evaluating the effects of an acute environmental stress such as fire. Coleoptera responses appeared to be representative of the total arthropod community.

Carbohydrate Metabolism in Fish-III

Abstract: In order to examine the previous assumption that the primary energy source for carp is not carbohydrate (glucose) but protein (amino acids), incorporation of radioactivity from glucose-U-14C or glutamate-U-14C into hepatopancreatic lipid and glycogen, blood glucose, and its excretion as 14CO2 in carp were measured Carp used were bred for 45 days with two kinds of diet, HC (90% carbohydrate) and C (50% carbohydrate), which were composed of potato starch and casein Excretions of 14CO2 from glutamate-U-14C of both diet groups were extraordinarily higher than those from glucose-U-14C In both groups, glucose-U-14C was hardly incorporated into hepatopancreatic lipid but was incorporated into glycogen In contrast, much more glutamate-U-14C was incorporated into lipid whereas little into glycogen The blood glucose levels of both diet groups were unusually increased probably by injections of glutamate-U-14C with carrier glutamate, and the radioactivities in blood glucose 6 hours after the injections were 1/7 to 1/5 of the residual activities from glucose-U-14C From these results it was suggested that oxidation of amino acids by carp is superior to glucose oxidation and that depot lipid is principally synthesized from amino acids while only a little glucose is converted to glycogen Therefore, amino acids appear to be a more excellent energy source than glucose in carp and the energy utilization resembles that in diabetic mammals

A lobular, ammonia-oxidizing bacterium, Nitrosolobus multiformis Nov. Gen. Nov. sp.

Abstract: Nitrosolobus multiformis is a lobular shaped, previously undescribed ammonia-oxidizing bacterium. The organism is ubiquitous and was isolated from soil samples obtained in various parts of the world. Its lobular nature and its internal, partially compartmentalized cytoplasm makes it morphologically unique and easily distinguishable from all other microorganisms. Physiological compartmentalization also occurs and is characterized by glycogen deposition in the peripheral compartments of the cell. The cells are obligate chemoautotrophs using CO2 and ammonia as primary carbon and energy sources. Its obligate chemoautotrophic nature stems primarily from a metabolic deficiency. Even though the cells cannot be grown on an organic medium the cells still have a slight heterotrophic potential and are able to oxidize and assimilate minute amounts of acetate in the absence of an inorganic energy source.

Energy in the world economy

Abstract: This book deals with quantitative aspects of long-term trends in energy consumption, production, and foreign trade; and, more particularly, with the transformation, during this century, of the world's fuel base away from coal and toward oil and natural gas These latter changes, which occurred at different times and rates in the major geographic regions, are particularly important for two reasons: they reflected, as well as facilitated, significant changes which were taking place in the world's industrial life and in economic activity in general; and they gave rise to wholly new patterns of regional economic interdependence The book sets out to accomplish three main tasks The first, upon which the others depend, is to assemble statistical series depicting movements in consumption, production, and international trade of energy commodities since 1925 by countries, regions, and the world as a whole Secondly, these voluminous statistical materials are winnowed in order to bring into sharp focus the main features of those movements The third task is to relate these main features to other economic variables and, in so doing, to provide an essential springboard for anyone wishing to evaluate prospects for the future Key data has been selectively updated to 1968 Part One describes and interprets the significant statistical findings Part Two presents a series of Statistical Profiles, each dealing with some unique facet of the overall picture These profiles are derived from the detailed statistics in Part Three Part Four deals with questions of methodology and definition connected with the detailed statistical series, and also provides country-by-country source notes Part Five presents selected supplementary materials: on energy and gross national product, matrix tables of international energy flows, and a brief bibliography

Comments on a proposed magnetospheric model

Abstract: Magnetospheric model characteristics, discussing auroral phenomena energy sources, magnetotail length, polar cusp, auroral oval and electrojet relationships, polar and magnetospheric substorms

Lateral transport of ions into the xylem of corn roots: I. Kinetics and energetics.

Abstract: A technique is described for study of the kinetics of lateral transport of ions across single roots of corn, Zea mays, in short term experiments under steady state conditions. The kinetics of chloride transfer to the vessels reflected the kinetics of absorption of chloride by the root cells. Efflux from the root vacuoles contributed to only a small extent to transport of chloride into the exudate. Lateral transport of chloride was inhibited by bromide at chloride concentrations in the ranges of both mechanisms 1 and 2 in a manner implicating competition. The uncoupler carbonylcyanide m-chlorophenylhydrazone used at 1 mum caused transfer of chloride to cease almost immediately at both low and high concentrations of chloride. Oligomycin depressed transport of chloride to the vessels within 10 to 15 minutes after application at 2 micrograms per milliliter. Inhibition by oligomycin was 75% at 0.5 mm chloride and 55% at 5 mm.It is concluded that lateral transport of chloride across corn roots is mediated by the dual mechanisms of ion absorption which reside in the plasmalemma. Transfer of chloride is inhibited by bromide and depends upon ATP as energy source. Chloride moves from the plasmalemma, the site of carriermediated absorption, to the xylem vessels by way of the symplasm. There is no evidence in these experiments that lateral transport of chloride in corn roots is governed by diffusion at any concentrations of chloride used in these experiments.

Utilization of Glucose and the Effect of Organic Compounds on the Chemolithotroph Thiobacillus ferrooxidans

Abstract: The utilization of glucose by the chemolithotroph Thiobacillus ferrooxidans results in a repression of the ability to oxidize iron, the substrate for autotrophic growth. An assay with resting cells was used to measure iron oxidation rates. Concomitant with the decreased iron oxidation rates, the enzyme responsible for carbon dioxide fixation, ribulose diphosphate (RuDP) carboxylase, was also repressed. Maximum iron oxidation rates precede peak RuDP carboxylase levels, consistent with the role of these processes in autotrophic metabolism in nonrepressed cells. The degree of iron oxidation repression depends on the organic substrate supplied, as does the level of RuDP carboxylase. The uptake of glucose parallels an increase in synthesis of glucose-6-phosphate dehydrogenase and the accumulation in cells of poly-β-hydroxybutyrate. The organism is also capable of growing on glucose and other organic supplements in the absence of its inorganic energy source; growth rates depend on the organic substrate supplied.

Energy and power

Abstract: The historical development of energy and power resources is discussed and the magnitude of our expanding need for power is examined. The economic, social, and environmental problems created by our rapidly expanding needs are described. The outlook for continued energy development is discussed.