bluuebunny/crossref_metadata_2025 huggingface dataset:
CD95 engagement induces disseminated endothelial cell apoptosis in vivo: immunopathologic implications
Authors: Janin Anne , Deschaumes Christophe , Daneshpouy Marjan , Estaquier Jérôme , Micic-Polianski Juliette , Rajagopalan-Levasseur Premavathy , Akarid Khadija , Mounier Nicolas , Gluckman Eliane , Socié Gérard , Ameisen Jean Claude
Published: October 2002

Fas (CD95) is a death receptor involved in apoptosis induction on engagement by Fas ligand (CD95L). Although CD95L-mediated apoptosis has been proposed as a pathogenic mechanism in a wide range of diseases, including graft-versus-host disease, systemic CD95 engagement in mice by agonistic CD95-specific antibodies or by soluble multimeric CD95L (smCD95L), though lethal, has been reported to cause apoptosis only in a limited range of cell types, that is, hepatocytes, hepatic sinusoidal endothelial cells, and lymphocytes. Another member of the tumor necrosis factor (TNF)/CD95L family, TNF-α, induces disseminated vascular endothelial cell apoptosis, which precedes apoptosis of other cell types and lethal multiorgan failure. Here we show that systemic CD95 engagement in vivo by agonistic CD95-specific antibody or smCD95L causes rapid, extensive, and disseminated endothelial cell apoptosis throughout the body, by a mechanism that does not depend on TNF-α. Disseminated endothelial cell apoptosis was also the first detectable lesion in a murine model of acute tissue damage induced by systemic transfer of allogeneic lymphocytes and did not occur when allogeneic lymphocytes were from CD95L-defective mice. Both vascular and additional tissue lesions induced by agonistic CD95-specific antibody, smCD95L, or allogeneic lymphocytes were prevented by treatment with an inhibitor of caspase-8, the upstream caspase coupled to CD95 death signaling. Vascular lesions are likely to play an important role in the pathogenesis of allogeneic immune responses and of other diseases involving circulating CD95L-expressing cells or smCD95L, and the prevention of CD95-mediated death signaling in endothelial cells may have therapeutic implications in these diseases.
HLA-B7 β-pleated sheet-derived synthetic peptides are immunodominant T-cell epitopes regulating alloresponses
Authors: Freese Anja , Zavazava Nicholas
Published: October 2002

Chronic rejection of transplanted allografts is the major cause of graft loss after clinical solid organ transplantation. Recent data link the indirect presentation of allopeptides to chronic graft loss; thus, identification of immunodominant epitopes on major histocompatibility complex (MHC) antigens could significantly contribute to establishing novel ways for monitoring and managing chronic rejection. Here, we show that synthetic allo-MHC–derived peptides covering the polymorphic region 56 to120 of HLA-B7 modulate alloresponses. In particular, the 2 β-pleated sheet-derived peptides covering residues 91 to 105 and 96 to 120, respectively, but not sequences from the α1 helix, were presented by autologous peripheral blood lymphocytes to induce T-cell proliferation. In addition, the 2 β-pleated sheet-derived peptides and the α1-derived peptide residues 60 to 75 abrogated lysis of HLA-B7 target cells by anti–HLA-B7 cytotoxic T lymphocytes (CTLs). Although most residues between 91 and 120 are normally not directly accessible to T cells, our results indicate that peptides derived from the lower surface of the peptide-binding groove of HLA-B7 are immunodominant in HLA-B7 alloresponses. To characterize the binding and stability of allopeptides to T cells, the 62-70 peptide—derived from the 60-75 allopeptide that blocked cytotoxicity of anti–HLA-B7 CTL—was synthesized and coupled with fluorescein isothiocyanate. The peptide specifically labeled anti-B7 CTL, but not anti–HLA-A2 CTL as measured by flow cytometry. Peptide binding to CTL was specific at 4°C and remained stable for 12 hours, whereas it remained stable for less than 2 hours at 37°C. These studies allow the identification of HLA-B7 T-cell epitopes and reveal for the first time a novel, previously unrecognized application of synthetic HLA-derived allopeptides to visualize alloreactive T cells.
Cytokine production and cytolytic mechanism of CD4+cytotoxic T lymphocytes in ex vivo expanded therapeutic Epstein-Barr virus–specific T-cell cultures
Authors: Sun Qi , Burton Robert L. , Lucas Kenneth G.
Published: October 2002

Ex vivo expanded Epstein-Barr virus (EBV)–specific T cells have been successfully applied clinically for adoptive immunotherapy. However, the role of CD4+ T cells in the therapeutic T-cell culture has not been established for the reconstitution of EBV-specific immunity. We isolated and characterized CD4+ T-cell lines from the ex vivo T-cell cultures. Monoclonal line PD-F4 and oligoclonal lines ND-R4 and TD-B4 were CD3+CD4+CD8−. Cytolytic tests with targets of mismatched major histocompatibility complex (MHC) and anti-MHC antibodies confirmed that the cytotoxicity of these CD4+ cells was restricted by MHC class II. Single cells of ND-R4 expressed interferon-γ (IFN-γ, or interleukin 4 (IL-4), but rarely coexpressed these 2 cytokines. In contrast, PD-F4 coexpressed IFN-γ, IL-2, and IL-4. Kinetic studies with PD-F4 showed that expression of the 3 cytokines plateaued 5 hours upon stimulation and was then drastically reduced, with a pattern consistent with independent modulation and differential off-cycle signal requirements. The cytotoxicity of these CD4+ cells was largely resistant to brefeldin A, an inhibitor for cytolytic pathways by Fas-ligand family molecules. Although sensitive to concanamycin A and ethyleneglycotetraacetic acid, which inhibit cytotoxicity by granule exocytosis, the CD4+ cytotoxic T lymphocytes (CTLs) did not express perforin, suggesting a cytotoxic mechanism independent of perforin although involving exocytosis. Flow cytometric analysis showed that the CD4+ CTLs expressed granulysin, a recently identified cytolytic molecule associated with exocytotic cytolytic granules. These data suggested that CD4+ T cells in the therapeutic B-lymphoblastoid cell lines–primed T-cell culture are diverse in producing TH1 and TH2 cytokines, and may exert specific cytotoxicity via exocytosis of granulysin.
MDM2 induces NF-κB/p65 expression transcriptionally through Sp1-binding sites: a novel, p53-independent role of MDM2 in doxorubicin resistance in acute lymphoblastic leukemia
Authors: Gu Lubing , Findley Harry W. , Zhou Muxiang
Published: October 2002

MDM2 protein is thought to exhibit tumorigenic activity by binding to the p53 tumor-suppressor protein and inhibiting its function. Alternatively, MDM2 may have oncogenic roles other than those resulting from p53 interactions. Here we report that MDM2 can induce expression of the p65 subunit of NF-κB, which is an anti-apoptotic factor expressed in certain neoplastic cells in response to chemotherapy. Initially, we noted that the overexpression of MDM2 protein in leukemic bone marrow cells of patients with B-cell precursor acute lymphoblastic leukemia (BCP-ALL), and an ALL cell line (EU-4) transfected with theMDM2 gene was associated with elevated expression of p65 and in vitro resistance to doxorubicin (Adriamycin). By cotransfection of the MDM2 gene and p65-promoter-reporter constructs into EU-4 cells, we found that transient and high-level MDM2 expression induced p65 promoter activity. In the presence of wild-type (wt) p53, MDM2 increased p65 promoter activity by reversing p53-mediated suppression of p65. In the absence of p53, MDM2 directly increased p65 promoter activity. Deletion and mutation analysis of the p65 promoter indicated that the region between nt −575 and −178, which contains the first and second Sp1-binding sites, was required for activation by MDM2. Further studies using chromatin immunoprecipitation (CHIP) and electrophoretic mobility shift assay (EMSA) showed that MDM2 was able to directly bind to the Sp1 site of the p65 promoter. Our findings suggest that by inducing p65 expression, MDM2 has a p53-independent role in tumorigenesis, which may further elucidate the association between MDM2 overexpression and resistant disease in childhood ALL.
Ex vivo treatment of proliferating human cord blood stem cells with stroma-derived factor–1 enhances their ability to engraft NOD/SCID mice
Authors: Glimm Hanno , Tang Patrick , Clark-Lewis Ian , von Kalle Christof , Eaves Connie
Published: October 2002

Ex vivo proliferation of hematopoietic stem cells (HSCs) is important for cellular and gene therapy but is limited by the observation that HSCs do not engraft as they transit S/G2/M. Recently identified candidate inhibitors of human HSC cycling are transforming growth factor-β1(TGF-β1) and stroma-derived factor–1 (SDF-1). To determine the ability of these factors to alter the transplantability of human HSCs proliferating in vitro, lin− cord blood cells were first cultured for 96 hours in serum-free medium containing Flt3 ligand, Steel factor, interleukin-3, interleukin-6, and granulocyte colony-stimulating factor. These cells were then transferred to medium containing Steel factor and thrombopoietin with or without SDF-1 and/or TGF-β1 for 48 hours. Exposure to SDF-1 but not TGF-β1 significantly increased (> 2-fold) the recovery of HSCs able to repopulate nonobese diabetic/severe combined immunodeficiency mice. These results suggest new strategies for improving the engraftment activity of HSCs stimulated to proliferate ex vivo.
THE DEVELOPMENT AND APPLICATIONS OF AIRBORNE MAGNETOMETERS IN THE U.S.S.R.
Authors: Logachev A. A. , Hawkes H. E.
Published: October 2002

Translator’s Note: These three papers by A. A. Logachev describe the pioneer work by the Russians in magnetic exploration with airborne equipment. Partly because of the language and partly because of the obscurity of the journals in which it was published, information on this work has not been widely circulated among American geophysicists. It is hoped that these translations will be of historical if not of practical interest to the profession.
MOTION OF AN ELASTIC SPHERE IN AN ACOUSTIC WAVE FIELD IN FLUIDS
Authors: Wolf Alfred
Published: October 2002

The motion of an elastic sphere in an acoustic wave field in fluids is determined as function of the elastic constants of the sphere, its radius, and the frequency of the wave field. It is found that the motion differs but little from the motion of an infinitely rigid sphere when the wave length of transverse waves in the elastic sphere is at least as long as the circumference of the sphere. The coefficient of zero order scattering potential in the fluid is determined.
AN OBSERVATIONAL METHOD TO OVERCOME ZERO DRIFT ERROR IN FIELD INSTRUMENTS
Authors: Roman Irwin
Published: October 2002

By using a four‐step oscillating method of observation, four values are obtained for the increment in the measured value between consecutive stations. If the drift or “zero creep” of the instrument is regular, even when large, or not linear, this furnishes a means of improving the reliability of the readings and permits the detection of erratic readings. In areal surveys, a primary net of values may be established by this oscillating method and this net used as a base into which to adjust chains of observations. Intermediate values may sometimes be desirable, such values being adjusted into the primary net by the oscillating method. An example shows the application of the method to a gravimetric survey.
THE FUNDAMENTAL EQUATIONS OF ELECTRICAL PROSPECTING
Authors: Maillet Raymond
Published: October 2002

In the United States the applications of electrical prospecting have been few. Thus it might appear superfluous to discuss exhaustively the method. On the other hand it has been applied quite extensively and successfully in the Eastern Hemisphere, particularly by French geophysicists, under the leadership of Conrad and Marcel Schlumberger. Important theoretical studies have resulted from this use which it is deemed worthwhile to summarize, at least along general lines.
WAVE‐FRONT CIRCLES FOR A LINEAR INCREASE OF VELOCITY WITH DEPTH
Authors: Van Melle F. A.
Published: October 2002

Formulas are derived which express the depths of the center of the wave‐front circle and its radius as simple algebraic functions of known geometric quantities. By virtue of their simplicity, these formulas are readily applicable to the migration of reflections. While not intended to replace wave‐front charts in areas of steep dip, they have proved their usefulness in areas of moderate dip.
HOW CAN GEOPHYSICS BE OF BETTER SERVICE TO THE MINING INDUSTRY?
Authors: Heiland C. A.
Published: October 2002

By comparison with geophysical exploration for oil, geophysical prospecting in mining is of limited scope, both areawise and dollarwise. To begin with, geologic exposures are abundant in many mining districts, making the application of geophysics unnecessary. Exploration targets in mining are usually so small by comparison with the promising area that blanket exploration becomes too costly if not impossible. The geophysicist is handicapped not only by difficult transportation but difficult topography as well which in addition produces a direct effect on some of his readings. Geophysical data are difficult to interpret because of geologic complexities; to make matters worse, the methods most applicable in oil exploration such as seismic and gravimetric, are frequently of limited usefulness. A geophysicist undertaking a mining project must keep these limitations well in mind. He should not recommend the application of geophysics where no better than existing geologic information can be anticipated. If possible, he should limit the size of prospecting territory by geologic reasoning and test his methods under known conditions. Above all, he should have not only sufficient geologic training, but good geologic imagination as well when analyzing his findings. He should not oversimplify his problems nor oversell his wares. On the other hand, he should feel justified in asking a fair compensation for his services because high standards of training in both physics and geology, plus a background of long experience, are required to do a good job. The mining industry can help by supplying freely, rather than withholding, all geologic data available and by assisting in the financing of industrial research aimed at the development and perfection of new methods. Organizations specializing in geophysical mine exploration are rarely in a position to do so. Many a mining geophysicist stays with his calling not because he expects great financial returns, but because he loves his job with its variety of geophysical problems and its fascinating complexity of geology. Geophysicists in mining have committed more than their share of errors with resultant disappointment on the part of industry. However, with a better understanding of the industry’s problems by the geophysicist, and the geophysicist’s problems by the industry, there is no reason why the use of geophysics in mining cannot be extended.
SEISMOGRAPH DETERMINATION OF SALT‐DOME BOUNDARY USING WELL DETECTOR DEEP ON DOME FLANK
Authors: Gardner L. W.
Published: October 2002

A method is given for determining the boundary of a salt dome, based upon first‐arrival time measurements of seismic waves from ordinary shotpoints distributed around the dome and received by a well detector within a deep hole flanking the dome. The three‐dimensional problem of locating the dome boundary, taking account of radial and vertical changes of velocity within the surrounding sedimentary section, is solved by the determination of vertical and horizontal cross sections of “aplanatic surfaces” as set forth. A practical procedure for such a survey is briefly outlined.
INDEX OF WELLS SHOT FOR VELOCITY (Second Supplement)
Authors: Swan B. G.
Published: October 2002

This is the second supplement to the original Index published in the October 1944 issue of Geophysics, the first supplement appearing in the October 1946 issue. Information is listed on 239 velocity surveys, most of which were shot in the years 1946, 1947, and 1948. A considerable number of foreign wells are included. Corrections and information missing on some of the surveys of the original Index and the 1946 supplement are tabulated.
PROPAGATION OF ELECTROMAGNETIC WAVES IN EARTH
Authors: Haycock O. C. , Madsen E. C. , Hurst S. R.
Published: October 2002

The successful use of radar for locating objects has led the authors to consider the possibility of using it to determine discontinuities within the earth. Knowledge of the propagation characteristics of waves in the earth is required before such a development might be undertaken. The present article reviews the literature in this field and reports experiments in which the velocity, attenuation, and wave length of electromagnetic waves in certain earthy materials were measured. The conclusion describes the possibilities of such development based on the experimental results.
A NOTE ON MULTIPLE REFLECTIONS
Authors: Higgins G. E.
Published: October 2002

It was most interesting to read the January 1948 issue of Geophysics which was devoted to articles on multiple reflections and I would endorse the plea of Mr. Robert H. Mansfield for an issue of Geophysics to be devoted to the troublesome problems of offside energy in seismic prospecting. Trinidad has recently been the scene of intensive geophysical investigation, both gravimeter and reflection on seismic, and while neither method gives unambiguous answers to the local geologic problems, it is about the reflection seismic results which I should like to discuss. The first period of intensive seismic investigation in Trinidad was during 1938–1939 and certain anomalies observed then received further investigation during 1946–1947. During both periods of investigation, two particular phenomena were observed which may be called: 1. Near‐shore effect. 2. Coning.
DENSITY DETERMINATIONS BY UNDERGROUND GRAVITY MEASUREMENTS
Authors: Hammer Sigmund
Published: October 2002

Gravimeter observations, in a vertical shaft, 2,247 feet deep, of the Pittsburgh Plate Glass Company’s limestone mine at Barberton, Ohio, for the purpose of determining the densities of the subsurface rock strata, are reported. The survey was made with a standard‐type gravimeter to simulate the data which would be obtained by a borehole gravimeter to aid in the anticipation and formulation of problems in the development and application of a borehole gravimeter for gravity prospecting. Density measurements on many selected core drill rock samples are compared with the densities determined from the gravimeter data. The individual sample measurements show large scatter and systematically low values. Attempts to restore the samples to initial conditions underground were unsuccessful. It appears that density determinations of finite intervals of underground rock strata can be done better with the gravimeter than by laboratory measurements of rock samples.
DEEP BASEMENT REFLECTIONS IN BIG HORN COUNTY, MONTANA
Authors: Junger Arne
Published: October 2002

During a seismic survey in Big Horn County, Montana, a number of deep reflections from 7.0 to 8.5 seconds were observed. The reflecting surfaces are relatively flat as shown by the small step‐outs. It is demonstrated that these reflections cannot be multiples and that they therefore must come from inside the basement at depth of 18 to 21 km. The nature of the reflecting surfaces cannot be determined from available data, but it is pointed out that they fall in the depth range generally stated for the depth of the granitic layer.
SALT SOLUTION, A SEISMIC VELOCITY PROBLEM IN WESTERN ANADARKO BASIN, KANSAS‐OKLAHOMA‐TEXAS
Authors: Widess M. B.
Published: October 2002

Solution of salt from a shallow Upper Permian formation in parts of Western Anadarko Basin was observed to produce a pronounced and relatively abrupt velocity change, such as to cause over 300 feet of seismic relief error across a distance of less than three miles. Core‐hole velocity shooting and velocity profiling were used in the study of the effect of salt solution. The theory, methods, and results of the velocity profiling program are described. The core‐hole velocity data indicate that in the area several environments are present which involve different types of velocity alteration by ground water activity. This kind of phenomenon is considered to be of general significance and related to the spurious representation of surface topography sometimes observed in seismic structural maps.
THE INTERPRETATION OF ELECTROMAGNETIC REFLECTION DATA IN GEOPHYSICAL EXPLORATION PART II.—METALLIC MODEL EXPERIMENTS
Authors: Yost W. Jacque , Caldwell R. L. , Beard C. I. , McClure C. D. , Skomal E. N.
Published: October 2002

A metallic model of a horizontally stratified section of the earth’s crust has been constructed to provide information of considerable value in the interpretation of geophysical data. Modeling considerations and experimental arrangements are discussed in detail for a system employing loops of wire as transmitter and receiver for the study of propagation of electromagnetic energy in and on a semi‐infinite conductor. An experimental check of the theory given in Part I (Yost, 1952) has been made for the case of a semi‐infinite conducting medium underlying a semi‐infinite insulator. Discontinuities in electrical conductivity within such a medium have been shown to reflect electromagnetic pulses back to the surface. A detailed study of the shape of these pulses from single reflectors has been made showing that certain characteristics of the pulse shape can be correlated with the depth and nature of the reflecting horizon. The reflected signals can be approximately described by considering the discontinuities as reflectors which, in turn, can be replaced by virtual “image” oscillators in a homogeneous structure. The extent to which this approximation holds is discussed in the light of experiments with the model. An example is given of the use of a non‐concentric loop arrangement for geophysical profiling of a limited reflector, such as a salt dome. Finally, data are given to show the agreement between model signals and field results obtained from a known resistivity contrast in the earth.
THE FORM AND LAWS OF PROPAGATION OF SEISMIC WAVELETS
Authors: Ricker Norman
Published: October 2002

An attack has been made upon the problem of the form of the seismic disturbance which proceeds outward from the explosion of a charge of dynamite and the laws of propagation of this disturbance. A mathematical theory was developed about ten years ago and a small amount of experimental work carried out at that time encouraged further efforts. Recently an extensive series of experimental researches have been carried out in a sensibly homogeneous shale section, and as a result of these studies a rather clear understanding of the form and nature of the primary seismic disturbance, and its laws of propagation, has been obtained for shale. The results are in good agreement with the theory.
A METHOD FOR MEASURING THE ELECTRICAL CONDUCTIVITY OF DIAMOND DRILL CORE SPECIMENS
Authors: Ward S. H.
Published: October 2002

Conductive methods of measuring electrical conductivity are unsatisfactory for testing diamond drill core specimens of metallic ores. An inductive method which avoids many of the inherent difficulties of the conductive methods is described. The method consists of measuring the change of impedance of solenoid when a core specimen is inserted in it. A correlation between the change of impedance of the solenoid and the physical properties and dimensions of a spherical core is achieved mathematically. This result is extended, empirically, to include cylindrical cores. A convenient way to make the required measurements is outlined, followed by a description of the design of a particular inductive conductivity meter. Sample results obtained with this instrument are presented, and one application of the method is mentioned.
A NOTE ON DOWNWARD CONTINUATION OF GRAVITY
Authors: Trejo César A.
Published: October 2002

Comparing calculated and exact values in an ideal example, it is shown that Peters’ proposed method of downward continuation of gravity is far less suitable than a combination of Peters’ procedure for upward continuation and a finite differences method for downward continuation. It is shown also how Peters’ method can be substantially improved by considering only the closest values in the downward step of a continuation process.
THE PRESENT STATE OF GEOTHERMAL INVESTIGATIONS
Authors: Birch Francis
Published: October 2002

At present, the emphasis in geothermal studies in non‐volcanic areas is on the flow of heat to the surface, a quantity of much theoretical importance. The number of reliable determinations of heat flow is still small, with few of the oil‐producing regions represented. While thermal gradients range from about 5 to 70°C/km, most of the measurements of heat flow fall within the range [Formula: see text], including the recent values for the deep ocean basins. There are suggestions of regional variations, but many more measurements reliable to 10% or better will be needed for further progress. The study of regions or provinces, rather than single localities, is especially desirable, and should be feasible in areas extensively drilled for oil. The principal requirements, which are difficult to meet, are: 1) approximate thermal equilibrium, which may require an undisturbed period of many months, and 2) availability for laboratory study of cores representing the major formations penetrated by the well. A renewal of interest in this subject among oil geologists, with recognition and exploitation of opportunities as they arise, could greatly advance its development.
ADDITIONAL NOTES ON THE RESOLVED‐TIME COMPUTING METHOD
Authors: Rice R. B.
Published: October 2002

The basic elements of a time‐resolution method of performing reflection seismograph computations have been published previously. The purpose of this paper is to present additional material to show how, by varying the spacing between shot‐points on the time cross‐section, the method may be made to give results comparable to various standard techniques and to describe the corresponding time method of handling cross‐spread data. An additional example showing actual cross‐sections computed by the method is included.
NOTES ON THE USE OF MULTIPLE GEOPHONES
Authors: Lombardi Leonard V.
Published: October 2002

The use of multiple geophones, which has been largely empirical, serves two primary functions: cancellation of random and other unwanted energy, and improved sampling of the wave front. Curves are presented showing effectiveness of several different spreads for surface‐wave cancellation. The results also apply to mixed records. Cancellation of random energy follows conventional sampling theory, varying with the square root of the number of geophones in the spread. Sampling of the wave front is more complex because the samples are not mutually independent.
MAGNETIC PROSPECTING FOR IRON ORES IN JAMAICA
Authors: Vincenz S. A.
Published: October 2002

Two ground magnetometer surveys over iron ore deposits in Jamaica are described and the results of the observations interpreted. An improvised but economical technique is used to measure the main magnetic properties of ore samples obtained from surface exposures, and a suitable statistical analysis is applied to determine the significance of these observations. The interpretation of the magnetic profiles, carried out on the basis of these observations, is complicated by the non‐uniformity of the natural remanent magnetization of the ores and the roughness of Jamaican topography. The ambiguities due to the latter factor are diminished by taking into account in the computations the changes in the elevation of the ground surface. The results of the interpretation are on the whole successful and give the approximate sizes and positions of the main ore bodies. A conclusion is reached that, in the case of small‐scale near‐surface deposits whose approximate position is already known, ground magnetometer surveys can be superior to those made from the air because of their smaller cost and greater power of resolution in rough terrain.
SOME APPLICATIONS OF GEOPHYSICAL PROSPECTING IN THE UNION OF SOUTH AFRICA
Authors: Enslin J. F.
Published: October 2002

The major application of geophysical prospecting in the Union of South Africa is in determining locations for drilling water wells. Four principal approaches are employed: 1. Permeable contact zones between igneous intrusions and sedimentary rocks are sought by magnetic surveys. 2. Basins of decomposition are sought by the resistivity method. 3. Narrow water‐bearing fissures and fault zones are located by an electromagnetic method. 4. The water‐bearing and water‐yielding properties of rocks are determined from their computed resistivities. The interpretation of resistivity depth probe curves is based on an empirical method which corrects for lateral effects. Another important application of geophysical prospecting in the Union is in gold‐mining. Gravitational and magnetic surveys have been widely used in the search for auriferous reefs in the Wit‐waterstand system which are concealed by a deep cover of younger rocks. Resistivity, electromagnetic, gravitational, and seismic methods have been applied to problems of engineering geology, including the delineation of areas in dolomite where sinkholes may occur.
REGIONAL GRAVITY SURVEY IN NORTHEASTERN OKLAHOMA AND SOUTHEASTERN KANSAS
Authors: Cook Kenneth L.
Published: October 2002

In 1948 the U. S. Geological Survey, in cooperation with the U. S. Coast and Geodetic Survey, made a regional gravity survey in northeastern Oklahoma and southeastern Kansas in connection with the studies of the deflection of the vertical. About 550 gravity stations were occupied with spacings of 5 to 10 miles in parts of 54 counties, and a Bouguer anomaly map, contoured at intervals of 5 milligals, was drawn. In southeastern Kansas there is a lack of correlation of regional gravity with known regional structural geology. The observed gravity anomalies are apparently caused principally by variations of density in the Precambrian basement and indicate a basement of complex nature, made up of rocks of contrasting properties, with a regional grain striking predominantly west or west‐northwest. In northeastern Oklahoma the several observed regional gravity anomalies indicate different degrees of correlation of regional gravity with regional structural geology. In the Precambrian highland area in Osage, Pawnee, and Creek Counties, there is a lack of correlation, as the gravity anomaly is probably caused chiefly by density contrasts within the basement complex. The anomaly associated with the Hunton arch is probably caused partly by structural relief of the rocks of pre‐Pennsylvanian age and partly by density contrasts within the basement, and thus indicates some correlation. The steep gravity gradients along the outer flanks of the Ozark uplift indicate good correlation with the subsurface geology. The great anomaly over the Arkansas basin, which indicates a close correlation, is probably caused largely—but perhaps not entirely—by downwarping of the basement and pre‐Pennsylvanian rocks.
THEORY OF A RESONANCE METHOD TO MEASURE THE ACOUSTIC PROPERTIES OF SEDIMENTS
Authors: Toulis W. J.
Published: October 2002

The theory of resonance for a pressure release cylindrical chamber is explored and equations are derived for determining absolute values of the velocity of sound and the attenuation constant in sediment samples. The essential measurements that need to be made are the determination of the frequencies of the lower modes of resonance and the associated sharpness of resonance. Corrections are derived also for the finite thickness and the acoustic losses in the chamber walls.
REGIONAL GRAVITY SURVEY OF PARTS OF TOOELE, JUAB, AND MILLARD COUNTIES, UTAH
Authors: Johnson J. Burlin , Cook Kenneth L.
Published: October 2002

In the summer of 1955 a regional gravity survey was made in parts of Tooele, Juab, and Millard Counties, Utah. A total of 455 gravity stations were occupied in an area of about 1,700 square miles. A Bouguer anomaly map was compiled with a contour interval of 2 milligals. Steep gravity gradients indicate major Basin and Range fault zones along the eastern margin of the Cedar Mountains, the southwestern margin of Davis Mountain and its associated outcrops, the northeastern margins of Camels Back Ridge and Simpson Buttes, the eastern margin of Granite Mountain, and the northern margin of the Dugway Range. The principal trend of these fault zones is northwesterly; and they were instrumental in partly outlining several of the mountain ranges in the surveyed area. Great graben with probable vertical displacements of at least several thousand feet were found east of Granite Mountain and northeast of Camels Back Ridge. The highest gravity values, which lie just northwest of Granite Mountain, are about 40 milligals higher than the surrounding surveyed region. Gravity anomalies transecting the Dugway and Thomas Ranges probably indicate pre‐Basin and Range faulting.
THE USE OF A LEAST SQUARES METHOD FOR THE INTERPRETATION OF DATA FROM SEISMIC SURVEYS
Authors: Scheidegger A. E. , Willmore P. L.
Published: October 2002

During large‐scale seismic surveys it is often impossible to arrange shot points and seismometers in a simple pattern, so that the data cannot be treated as simply as those of small‐scale prospecting arrays. It is shown that the problem of reducing seismic observations from m shot points and n seismometers (where there is no simple pattern of arranging these) is equivalent to solving (m+n) normal equations with (m+n) unknowns. These normal equations are linear, the matrix of their coefficients is symmetric. The problem of inverting that matrix is solved here by the calculus of “Cracovians,” mathematical entities similar to matrices. When all the shots have been observed at all the seismometers, the solution can even be given generally. Otherwise, a certain amount of computation is necessary. An example is given.
REPORT OF SEG SUBCOMMITTEE ON INFORMATION ON MAGNETIC RECORDER CHARACTERISTICS
Authors: Kaufman S. , Parrack A. L. , Skelton J. D.
Published: October 2002

Information on geophysical magnetic recording and play back systems has been obtained from specifications furnished by the several manufacturers. As will be seen in the following summary, the various systems differ in basic design features to such a degree that it is difficult to anticipate the achievement of any large‐scale standardization. This information is presented as being of interest to those concerned with the handling of seismic data, but with no intention of suggestion or recommendation.
DISCUSSIONS ON “A THEORETICAL STUDY OF INDUCED ELECTRICAL POLARIZATION”
Authors: Wait James R.
Published: October 2002

The analysis in the quoted paper is an attempt to calculate the induced polarization response of a two‐layer flat earth. The upper layer is a homogeneous overburden of thickness h with a resistivity [Formula: see text] and a dielectric constant of [Formula: see text]. The lower (semi‐infinite) medium which is the “aquifer” has a resistivity [Formula: see text] and dielectric constant [Formula: see text]. The value of the relaxation voltage as seen at the potential electrodes “immediately after” the current is shut off is designated Δϕ. The A’s of the above paper present a method for calculating the ratio Δϕ/V where V is the steady voltage across the potential electrodes during the time of current flow.
CASE HISTORY OF THE SOJOURNER OIL FIELD HASKELL COUNTY, TEXAS, A GEOCHEMICAL CONFIRMATION
Authors: Ransone W. R.
Published: October 2002

Petroleum accumulation at the Sojourner field, Haskell County, Texas, was found in a lower Pennsylvanian sand pinch out. The prospect was first recognized as anomalous on a reconnaissance geochemical survey, leased, and then detailed by reflections, on the basis of which the discovery well was located. Since the field has been completely developed, the prediscovery predictions of the geochemical and reflection surveys can be compared with the subsurface known from well data. Pertinent maps are shown together with a discussion of the local geology and field development.
INTERPRETATION METHODS FOR GEOPHYSICAL EXPLORATION OF RESERVOIRS
Authors: Unz M.
Published: October 2002

Geophysical exploration methods can be valuable for the investigation of filled storage reservoirs. Impressed current circuits or natural ground potentials are analyzed for this purpose. General structural data are obtained from horizontal resistivity profiles. Ground bed details and seepage zones can be located by means of underwater equipotential surveys. Salinity and temperature measurements serve for the hydrological investigation of submerged springs and streams in natural lakes. The proposed interpretation methods can be readily adapted to specific local conditions.
MAGNETIC DIPOLE NOMOGRAMS
Authors: Price Charles E.
Published: October 2002

Two nomograms or alignment charts are presented for the solution of the magnetic‐dipole equations for magnetic intensity over a dipping dipole. The two charts are used in conjunction with each other and are as accurate as is needed for field work. One of these charts will be found useful also in other calculations involving [Formula: see text].
MATHEMATICAL FORMULATION AND TYPE CURVES FOR INDUCED POLARIZATION
Authors: Seigel Harold O.
Published: October 2002

A basic mathematical formulation is developed for overvoltage and other induced polarization phenomena. Starting from the fundamental representation of a volume dipolar distribution, one is led to the concept of a change in apparent conductivity due to polarization effects. The mathematical solution of induced polarization phenomena, therefore, reduces to the appropriate solution of Laplace’s equation for the same geometry and conductivity distribution ignoring polarization, followed by partial differentiation of the apparent resistivity function so determined. The dielectric constants of the media are not involved in the solution. As examples of the use of the representation, the response of a polarizable sphere and of a polarizable lower layer in a typical two‐layer case are presented. Actual field results are shown illustrating the use of the latter solution.
DISCUSSION OF INTERNAL FRICTION OF FINE GRAINED LIMESTONES
Authors: Treitel Sven
Published: October 2002

I wish to point out an ambiguity in the otherwise excellent paper by Peselnick and Zietz, “Internal Friction of Fine Grained Limestones,” that appeared in the April, 1959, issue of Geophysics. The authors derive a distance attenuation coefficient [Formula: see text], [Formula: see text]which is proportional to the first power of the circular frequency ω, and show experimentally that [Formula: see text] is indeed a linear function of ω. The quantity [Formula: see text] is, however, not the attenuation coefficient usually employed in the pertinent literature.
CONTINUOUS SIGNAL SEISMOGRAPH
Authors: Crawford John M. , Doty William E. N. , Lee Milford R.
Published: October 2002

The paper describes a seismic method in which a continuous signal vibrator provides the source energy. Operational features as well as some general theoretical considerations are discussed.
LOG INTERPRETATION IN SANDSTONE RESERVOIRS
Authors: Wyllie M. R. J.
Published: October 2002

By comparison with carbonate rocks sandstones are texturally homogeneous; in consequence the interpretation from well logs of the fluid content and physical properties of sandstones is relatively simple. From an exploration standpoint one significant fact must be gleaned from the log: Will the formation of interest produce oil or gas? The precise porosity and thickness of the formation and its exact hydrocarbon saturation are, initially, secondary considerations. Some of the principal difficulties involved in determining interstitial water resistivity, porosity and formation resistivity are examined. It is confirmed that the so‐called “low zone” significantly decreases the resistivity of an oil‐bearing sand when this resistivity is found from an induction log. Theory and laboratory experiment confirm that diffusion and convective mixing of the filtrate and interstitial water do little to mitigate the problem. It is suggested that future correction charts for induction logs recognize this fact. New data bearing on the dirty sand problem show that if formations contain interstitial clay the interpretation procedure suggested by A. J. de Witte is substantially correct. It is pointed out that the real problem is to decide the manner in which the clay content of a typical dirty sand is disposed. Measurements on the effect of the porosity of sandstones on the difference between velocities through them when dry and fully water‐saturated disclose an interesting paradox: The velocity difference is a maximum when the porosity is a minimum. Significant differences in velocity between gas‐ and water‐saturated sandstones are not to be expected in the porosity range of practical significance.
THE INFORMATION CONTENT OF A RIEBER SONOGRAM
Authors: Trorey A. W.
Published: October 2002

Shortly after F. Rieber originally proposed the seismic data processing method of controlled directional sensitivity (CDS), whose end‐product is a “sonogram,” considerable criticism and discussion of the method appeared in geophysical literature. Certain of this criticism apparently had to do with the belief that CDS did not faithfully preserve all the information contained in the original field recording. This paper shows by a simple argument based on Fourier Transforms that CDS causes no such loss of information.
THE RECIPROCAL METHOD OF ROUTINE SHALLOW SEISMIC REFRACTION INVESTIGATIONS
Authors: Hawkins L. V.
Published: October 2002

The Reciprocal Method of shallow seismic refraction investigation provides a simple reliable method of surveys where the absolute depths to important refractors and an analysis of the velocities in the refractors are required in detail. The depth computation is based on an early (1931) concept, termed here the time‐depth, which differs slightly from the delay‐time. The calculation of the individual time‐depths and of the corrected travel times within the refractor require only simple numerical computation. Hence, the method is very suitable for routine survey procedures in which use is made of composite velocity terms for multilayered overburdens. The basis and procedures of the Reciprocal Method are presented together with examples illustrating the application of the method and the technique of velocity analysis.
STUDY OF MULTIPLE REFLECTIONS USING A ONE‐DIMENSIONAL SEISMIC MODEL
Authors: Bennett A. D.
Published: October 2002

A one‐dimensional seismic model consisting of a multisection metal rod was used in a study of multiple reflections. The model was designed from velocity data provided by an acoustic velocity log. Reflecting interfaces were introduced into the model by changing the rod diameter. An acoustic pulse simulating a shot was applied near the top of the model by a magnetostrictive transducer. Reflections were detected by a crystal receiver placed at the top of the model. Means were devised to achieve an acceptable correspondence in character between a field seismic record obtained at a well site and a synthetic record produced by the model based on acoustic velocities in the well. Model techniques were worked out to separate and identify primary and multiple reflections as an aid in the interpretation of field seismic records.
COUPLING EXPLOSIVE ENERGY TO ROCK
Authors: Nicholls Harry R.
Published: October 2002

Two types of explosive‐to‐rock coupling were investigated—geometrical and impedance. Strain amplitudes generated by an explosion in a borehole are shown to vary with charge and hole dimensions. Strain amplitudes and strain energy in the rock also are shown to be dependent on the properties of the explosive and the medium surrounding the shothole. Deviations from acoustic theory predictions are noted.
NEW INTERPRETATION TECHNIQUES FOR TELLURIC AND SOME DIRECT CURRENT FIELDS
Authors: Roy Amalendu
Published: October 2002

Since the normal derivative of the telluric potential at the ground surface is zero, the odd terms in the Taylor expansion disappear, resulting in a simple technique of computing the downward continued potentials. The top of the nonconducting basement is a flow surface and can, therefore, be determined by sketching in curves orthogonal to the (continued) equipotential lines in suitably chosen sections. A model tank example is given. The applicability of the method of continuation to the interpretation of self potential data is also illustrated. A discussion of the derivatives, two limiting formulas, and a method for calculating telluric anomalies are included.
REPLY BY AUTHOR TO DISCUSSION BY STEPHEN THYSSEN‐BORNEMISZA AND W. F. STACKLER
Authors: Bible John L.
Published: October 2002

The Terrain Correction Table was intended for use primarily on a routine gravity survey for oil exploration where structure of interest will be a minimum of several hundred ft deep and the time involved in making the determination is of importance. Nevertheless, the table is equally adaptable to closely‐spaced stations if proper care is exercised in determining the elevation differences in the various compartments. For corrections larger than 0.01 mgal, the table has been graduated in steps of 0.01 mgal, which is the limit of accuracy of most gravimeters; however, where greater accuracy is required, closer terrain determinations can be made by interpolation. The near‐surface density must be taken into consideration in using the table as a density of 2.0 was selected for the base. The near‐surface density effect is of more concern in the Bouguer rather than in the terrain correction since the latter is the smaller of the two, approaching insignificance, especially in Zones B and C, if proper care is exercised in selecting the observation site.
PRELIMINARY STUDY OF THE CRUSTAL STRUCTURE ACROSS THE CAMPECHE ESCARPMENT FROM GRAVITY DATA
Authors: Henderson Garry C.
Published: October 2002

A possible structure of the earth’s crust across Campeche Escarpment, Gulf of Mexico, was resolved by utilizing the gravity measurements made on the A&M College of Texas Research Vessel HIDALGO and by combining these data with published seismic information. The La Coste‐Romberg surface‐ship gravity meter S‐9 of A&M College, owned by the Office of Naval Research, was the gravity instrument used. The method used herein effectively reduces an infinite number of possible structures to a few possible structures. A total of 915 km of continuous gravity profile was traversed from June 29 to July 1, 1961. Accuracy of the gravity profiles appears to be satisfactory for this kind of crustal investigation. This report is intended as a basis for further studies; no attempts were made to ascertain the geologic events in detail. From this investigation it appears that the escarpment is nontectonic in origin, although the possibility of a crustal fault below the escarpment cannot be ignored.
DELINEATING LOW‐VELOCITY LENSES
Authors: Schenck Frederick L.
Published: October 2002

The end of a low‐velocity lens diffracts energy emerging after reflection at a lower level. Conventional interpretive treatment of such energy as an undiffracted reflection could lead to serious inferences of nonexistent structure. Constant moveout down the record is the main criterion for the diffracted reflection situation. The diffractive source, assuming the velocity in the surrounding material to be known, is found as the envelope of emergent travel paths. Reflected energy from the top of the feature, if recognized, can be analyzed for delineating the upper limit of the body. The thickness can be estimated from observed delay times. For discovering and delineating low‐velocity lenses, long reflection spreads should be used.