67 research outputs found
Data file on amino acid distribution in calcified and uncalcified tissues of shell-forming organisms
Originally issued as Reference No. 66-27, series later renamed WHOI-.Largely for reason of limited space, scientific journals can only accept
brief articles. Thus full accounts on analytical techniques, data files, and
other details are frequently omitted, and pertinent information may be lost.
Although this information is only of peripheral interest to the general reader,
to the fellow scientist it is of vital significance.
In order to serve both the specialist and the general reader, we have
prepared a series of manuscripts dealing exclusively with either background information
or the actual interpretation and discussion of the data.
The present report is aimed chiefly at the specialist interested in calcification
processes in biological systems, in molluscan ecology and phylogeny, and
in amino acid analyses. It incorporates information on: (a) type, locality,
and environment of sample material, (b) analytical techniques, (c) utilization
of a digital computer and (d) quantitative amino acid analysis in the form of
data sheets, i,e. computer printouts.The work was supported by grants from the National Aeronautics and Space
Administration (NSR-22-014-001) and the American Chemical Society (PRF-1943-A2)
Data on the distribution of stable isotopes and amino acids in Indian Ocean sediments
Originally issued as Reference No. 68-4, series later renamed WHOI-.In February-March 1965, a series of piston cores were taken aboard ATLANTIS II
off the coast of Arabia, Pakistan, and India (Figure 1) in water depths of about 3,000
meters. The principal objectives of this program were (a ) to obtain information on the
change in petrology of the sediments as a function of geography and depth (b) to study
the microfauna in the sediment profiles, and (c) to apply geochemical tools for the
elucidation of the diagenetic fate of the organic matter and the history of the sediments.
This article presents data on the geochemical part of the project. Principally, we are
concerned with the oxygen and carbon isotope distribution in carbonates, the carbon isotope
composition of sedimentary organic matter, and the amino acid composition of the sediment
material. These studies represent a part of a larger program at our Institute which is
concerned with the distribution of (a) stable isotopes and (b) organic compounds such as
amino acids, carbohydrates, or hydrocarbons in recent and ancient sediments, natural
waters, and marine organisms.National Science Foundation
under Grant GP-490
Late Pleistocene-Holocene chemical stratigraphy and paleolimnology of the Rift Valley lakes of central Africa
The interaction of climate and geology in Central Africa during
Late Pleistocene and Holocene is examined. The study is based on sedimentological
and limnological work on the main lakes of the Western Branch
of the East African Rift Valley, particularly Lake Kivu, Changes in
sediment chemistry, mineralogy and diatom assemblage provide a detailed
histogram of lake level oscillations. Calculations indicate that the
drop in lake level could be as high as 600 m for Tanganyika and 400 m for
Kivu, Fluctuations in water levels.are the means for reconstruction of
climatic events in tropical Africa of the last 15,000 years. Paleoclimatic
comparison between tropical and temperate zones reveals that
pluvial times coincide with the prominent interstadials in Europe, e.g.
Bølling, Allerød, Climatic Optimum, and reversely, cool and dry periods
in equatorial Africa with ice ages in the Northern Hemisphere.
The African climatic sequence of pluvials and interpluvials is
accompanied by corresponding periods of hydrothermal activity and quiescence.
This may suggest that rain water exercises control on hydrothermal.
activities.Prepared for the National Science Foundation
under Grants GA-30641 and GA-35334
Molecular mechanisms on interactions between oxygen co-ordinated metal polyhedra and biochemical compounds
Information is presented on the structural and functional properties of phosphates in "biochemical systems. Phosphates follow four structural formation principles:
(1) linkage of phosphate units via oxygen co-ordinated metal ion polyhedra,
(2) establishment of chains,
(3) cross linkages of chains resulting in corrugated layers, and
(4) cross linkages of layers resulting in distinct three-dimensional molecular
networks.
One Iinkage type does not require nor exclude another Iinkage type.
On the basis of this concept on the associations of phosphate tetrahedra and metal ion oxygen polyhedra, a revised molecular model for DNA is proposed. Metal ion oxygen polyhedra excercise control on the shape of the DNA, and thus may introduce
the stretching of the polymer chains This can be considered the ultimate reason why a single stranded DNA will associate itself readily with another single stranded DNA resulting in a double helix. In contrast, the coupling of a single stranded DNA by itself
in making a sharp bend (loop) will not take place due to the stabilization of the structure by means of the metal ion oxygen polyhedra backbone. This model also explains thefunctional properties of the nucleic acids, for instance, the oxide chains and layers will favor proton jumps, and in the presence of a differential potential, they will form proton conduction bands.
The molecular organization, as introduced by the association of metal ion coordination polyhedra with the PO4 groups, plays also a significant role in membrane dynamics. Analogous to the ion co-ordination interactions of polyphosphoric acids,
the fixation of metal ions at the P-O surface and of membranes will result in a distinct molecular geometry as a whole. In this way, the membranes will act as dynamic molecular sieves, whereby the mesh size and the functional characteristics of these molecular sieves is determined by the flexible interplay of metals and the individual phospholipid compounds contained in the membranes.
TP (111-P) is characterized for its ability to form a co-ordination polyhedron with polyvalent cations. In this way it resembles polyphosphates and differs from 1-P and 11-P. Triphosphate exhibits two significant properties:
(1) terminal chain degradation, i.e. the release of terminal PO4 groups and formation of PO3 radicals which is controlled by external electrical forces,and
(2) affinity to all cations by means of metal ion oxygen polyhedra and the establishment of an exchange affinity series for all metal ions.
Concerning the biosynthesis of polysaccharides, proteins, and the nucleic acids, three conditions have to be fulfilled;.
(1) acitvation of the react ion partner,
(2) maximum efficiency and minimum error, and
(3) well-defined control of the reactions in terms of kinetics and transportation
mechanism.
All three requirements are most effectively executed by triphosphates. The controlled formation of the reactive P03 radicaI not only activates the reaction partner, but also eliminates by means of the phosphate formation, the OH and O groups from the reaction system and this with extraordinary efficiency and elegance. In biochemical reactions, this role is commonly exercised by ATP.Submitted to the National Aeronautics and Space Administration under Contract NSR-22-014-001. and to the American Chemical Society under Contract PRF 1943-A2
Lake Kivu expedition : geophysics, hydrography, sedimentology (preliminary report)
In March 1971, seven members of the Woods Hole Oceanographic Institution
were engaged in a multidisciplinary study of Lake Kivu. This expedition represents
part of a long-range program concerned with the structural and hydrographical
settings of the East African Rift Lakes and their relationships to
the Red Sea and the Gulf of Aden Rifts. The program started in May 1963 with
a geophysical study on Lake Malawi (von Herzen and Vacquier, 1967). Several
expeditions of our Institution into the Red Sea and Gulf of Aden area in 1964,
1965 and 1966 (Degens and Ross, 1969) provided detailed geological information
on the "northern" extension of the East African Rift. And finally our study of
last year on Lake Tanganyika c1osed a major gap in the program; it allowed
us to out1ine a model on the evolution of a rift which starts with (i) bulging
of the earth's crust, (ii) block-faulting, (iii) volcanism and hydrothermal
activity, and which has its final stage in (iv) sea floor spreading (Degens
et al. 1971). In the case of Lake Tanganyika, only the second stage of this
evolution series has been reached, i.e. block-faulting. In contrast, the Red
Sea and the Gulf of Aden had already evolved to active sea floor spreading, almost
25 million years ago. Somewhere along the line between Lake Tanganyika
and the Gulf of Aden must lie the "missing link" of this evolution series.
Lake Kivu, almost 100 miles to the north of Lake Tanganyika is situated
at the highest point of the Rift Valley and is surrounded by active volcanoes
and geothermal springs. As recently as 1944, lava flows reached the lake
shore. This lake was therefore, a natural choice to test our hypothesis on
the origin and development of rifts. Furthermore, the occurrence of large
quantities of dissolved gases, e.g., CO2 and methane, represented an interesting
geochemical phenomenon worthwhile to investigate.Supported by the National Science Foundation
with Grants GA 19262, GB 20956, and GU 3927;
grants from the Petroleum Research Fund of
the American Chemical Society PRF#1943A2;
and by private research funds of the Woods
Hole Oceanographic Institution
Biocalcification through time: environmental challenge and cellular response
A concept explaining biocalcification as a form of calcium detoxification is advanced using geochemical and paleontological criteria. The first appearence of calcareous skeletons at the turn of the Precambrian/Cambrian is interpreted as a biotic response to a gradual rise of Ca2+ in world ocean resulting in Ca2+ stress environments in shelf areas. Periodic appearance in the Phanerozoic record of heavily calcified marine biota, absent or relic in modern seas, suggests considerable temporal fluctuations of calcium concentrations in the ancient ocean. Temporal changes in Ca2+ and mineral nutrient contents in the environment can thus be seen as overriding factors in the evolution of organisms
- …