bluuebunny/crossref_metadata_2025 huggingface dataset:
Formoterol in patients with chronic obstructive pulmonary disease: a randomized, controlled, 3-month trial
Authors: Aalbers R. , Ayres J. , Backer V. , Decramer M. , Lier P.A. , Magyar P. , Malolepszy J. , Ruffin R. , Sybrecht G.W.
Published: October 2002

The aim of this study was to investigate formoterol, an inhaled long-acting β2-agonist, in patients with chronic obstructive pulmonary disease (COPD).

Six-hundred and ninety-two COPD patients, mean baseline forced expiratory volume in one second (FEV1) 54%, FEV1/forced vital capacity 75% of predicted, reversibility 6.4% pred, were treated with formoterol (4.5, 9 or 18 µgb.i.d.) or placeboviaTurbuhaler® for 12 weeks. Symptoms were recorded daily. Spirometry and the incremental shuttle walking test (SWT) were performed at clinic visits.

Compared with placebo, 18 µgb.i.d. formoterol reduced the mean total symptom score by 13% and increased the percentage of nights without awakenings by 15%. Formoterol (9 and 18 µgb.i.d.) significantly reduced symptom scores for breathlessness (−7% and −9%, respectively) and chest tightness (−11% and −8%, respectively), reduced the need for rescue medication (−25% and −18%, respectively), and increased symptom-free days (71% and 86%, respectively). FEV1improved significantly after all three doses of formoterol (versusplacebo). No differences were found between groups in SWT walking distance. No unexpected adverse events were seen.

In conclusion, 9 and 18 µgb.i.d.formoterol reduced symptoms and increased the number of symptom-free days in a dose-dependent manner in chronic obstructive pulmonary disease patients. Formoterol improved lung function at a dose of 4.5 µgb.i.d.and higher.
Hospitalization trends for paediatric asthma in eastern Finland: a 10-yr survey
Authors: Korhonen K. , Reijonen T.M. , Malmström K. , Klaukka T. , Remes K. , Korppi M.
Published: October 2002

The prevalence of childhood asthma has increased during the past 20 yrs in eastern Finland. The use of regular medication for asthma has, consequently, also risen at the same time. The aim of the present study was to assess how these factors have influenced hospitalization for asthma in children.

Data concerning the annual number of children aged <16 yrs treated for asthma, their number of hospital periods, and length of hospitalization were collected using patient-specific medical records for the years 1988–1997.

Admissions for asthma more than doubled (from 1.2 in 1,000 to 2.7 in 1,000) (p<0.001), whereas re-admissions decreased from 28.1% to 8.7% (p<0.001) during the study period. The greatest increase was seen among children aged <2 yrs, whereas during recent years the admission rate among children aged >2 yrs has declined by one-third.

Despite the increased prevalence of asthma, the decline in admissions seen in all but the youngest children may, at least partly, be attributed to the decrease in re-admissions, resulting from the early onset and increased use of inhaled steroids.
What is the optimal treatment strategy for chronic obstructive pulmonary disease exacerbations?
Authors: Willaert W. , Daenen M. , Bomans P. , Verleden G. , Decramer M.
Published: October 2002

The present study aims to determine whether treating chronic obstructive pulmonary disease (COPD) exacerbations with intravenous steroids and aerosol bronchodilators (group I) is superior to oral steroids and multiple dose inhaler (MDI) bronchodilators with a spacer (group II).

Group I received 40 mg methylprednisolone·day−1intravenously with a decrease to 20 mg after 10 days and a further decrease of 4 mg·4 days−1. Aerosol therapy consisted of 10 mg salbutamol and 1 mg ipratropiumbromide·day−1. Group II received 32 mg methylprednisolone orally for 1 week followed by 24 mg·day−1for 4 days and a subsequent decrease of 4 mg·week−1. Duovent® MDI with a spacer was given at a dose of 1.6 mg fenoterol and 640 µg ipratropiumbromide·day−1.

In group I (n=19) forced expiratory volume in one second (FEV1) rose from 0.82±0.46 to 0.91±0.47 L and average dyspnoea decreased from 6.0±1.9 to 4.1±2.6 within 10 days. The Chronic Respiratory Disease Index Questionnaire (CRQ) score increased from 78±24 to 90±24 points after 4 weeks. In group II (n=18) FEV1increased from 0.70±0.27 to 0.90±0.29 L, dyspnoea regressed from 6.2±2.4 to 2.7±2.6 and CRQ from 67±17 to 86±20. Both groups showed similar results in dropout rate, length of hospital stay and patient satisfaction.

In conclusion, the two treatment strategies appear equally effective in treating chronic obstructive pulmonary disease exacerbations, although oral steroids and metered dose inhaler bronchodilators appear associated with a higher risk of hospital re-admission.
Computed tomography in staging for lung cancer
Authors: Verschakelen J.A. , Bogaert J. , De Wever W.
Published: October 2002

Computed tomography (CT) provides the most detailed imaging information, hence it is generally used as a routine imaging procedure in the tumour, node, metastasis (TNM)-staging of patients with lung cancer. However, despite the continuously ongoing process of improvement in CT scanning in which today's CT scanners combine fast acquisition, fast data reconstruction and high detail, the technique has important limitations.

CT can, in some cases, very accurately show tumour extent within, and predict spread beyond the lung. However, the question of whether the tumour has invaded the chest wall or the mediastinum and, if so, whether it is still potentially surgically curable often remains unanswered. In addition, the only sign for predicting lymph node involvement using CT is enlargement. Many studies have shown that this sign is not very reliable. CT is also, with success, being used to evaluate distant metastases although other techniques such as ultrasound and magnetic resonance imaging can have similar or higher accuracies.

Despite these well-known limitations, computed tomography will most likely stay the routine imaging procedure for determining resectability and for assessing intra- and extrathoracic spread of lung cancer. The improvement in technology will probably result a better T-staging. The role of computed tomography in nodal staging remains important. It offers the surgeon a road map of the lymph nodes and guides towards the nodes that need biopsy. Combining computed tomography with positron emission tomography, when it becomes more widely available, will add functional images to the detail of computed tomography and will not only improve nodal staging but will probably also allow a better evaluation of distant metastasis and reduce the number of unnecessary interventional procedures.
Nasal and oral contribution to inhaled and exhaled nitric oxide: a study in tracheotomized patients
Authors: Törnberg D.C.F. , Marteus H. , Schedin U. , Alving K. , Lundberg J.O.N. , Weitzberg E.
Published: October 2002

Nitric oxide (NO) is produced at different sites in the human airways and may have several physiological effects. Orally-produced NO seems to contribute to the levels found in exhaled air. Autoinhalation of nasal NO increases oxygenation and reduces pulmonary artery pressure in humans. The aim of this study was to measure the concentration and output of NO during nasal, oral and tracheal controlled exhalation and inhalation.

Ten tracheotomized patients and seven healthy subjects were studied. The mean±sem fraction of exhaled NO from the nose, mouth and trachea was 56±8, 14±4 and 6±1 parts per billion (ppb), respectively. During single-breath nasal, oral and tracheal inhalation the fraction of inhaled NO was 64±14, 11±3 and 4±1, respectively. There was a marked flow dependency on nasal NO output in the healthy subjects, which was four-fold greater at the higher flow rates, during inhalation when compared to exhalation.

There is a substantial contribution of nasal and oral nitric oxide during both inhalation and exhalation. Nasal nitric oxide output is markedly higher during inhalation, reaching levels similar to those that are found to have clinical effects in the trachea. These findings have implications for the measurement of nitric oxide in exhaled air and the physiological effects of autoinhaled endogenous nitric oxide.
Noninvasive ventilation after intubation and mechanical ventilation
Authors: Ferrer M. , Bernadich O. , Nava S. , Torres A.
Published: October 2002

Patients with chronic airflow obstruction who are difficult to wean from mechanical ventilation are at increased risk of intubation-associated complications and mortality because of prolonged invasive mechanical ventilation. Noninvasive positive pressure ventilation may revert most of the pathophysiological mechanisms associated with weaning failure in these patients.

Several randomized controlled trials have shown that use of noninvasive ventilation to achieve earlier extubation in difficult-to-wean patients or in patients who develop respiratory failure after apparently successful extubation can result in reduced periods of endotracheal intubation and complication rates and improved survival. However, this is not a consistent finding, and the currently available published data with outcome as the primary variable are exclusively from patients who had pre-existing lung disease. In addition, the patients were haemodynamically stable, with a normal level of consciousness, no fever and a preserved cough reflex.

It remains to be seen whether noninvasive positive pressure ventilation has a role in other patient groups and situations, such as prevention of postextubation failure or unplanned extubation. The technique is, however, a useful addition to the therapeutic armamentarium for a group of patients who pose a significant clinical and economic challenge.
Studying human airway pharmacology in microsections: application of videomicrometry
Authors: Schmidt D.T. , Dent G. , Rühlmann E. , Muñoz N.M. , Leff A.R. , Rabe K.F.
Published: October 2002

The influence of endogenously-released mediators and activated eosinophils on the airway lumen and the effect of passive sensitization on anti-immunoglobulin (Ig)-E-induced contractile responses was investigated by videomicrometry.

Human bronchial sections of 2–3 mm internal diameter, placed in 250 µL Hank's balanced salt solution on microtitre plates, were monitored and recorded by digitized image analysis. Airway preparations exhibited a spontaneous narrowing (mean±sem −33±5% of the luminal area). Removal of the bronchial epithelium almost completely prevented the development of spontaneuous narrowing (−6±3%; p<0.001). The addition of platelet-activating factor stimulated human eosinophils to the bronchial sections led to significant narrowing of the airway lumen (−39±9%; p<0.05). Passive sensitization induced hyperresponsiveness to polyclonal anti-IgE (−35±8%; p<0.01).

It is concluded that videomicrometry is suitable for studying interactions between human airways and inflammatory cells, as well as the effect of passive sensitization on smooth muscle reactivityin vitro, without the imposition of preload. Under these conditions, human airways exhibited a spontaneous decrease of the airway lumen over time suggesting a role for epithelium-derived mediators because the development of spontaneous tone was epithelium dependent.
Changes of exhaled nitric oxide during steroid treatment of childhood asthma
Authors: Beck-Ripp J. , Griese M. , Arenz S. , Köring C. , Pasqualoni B. , Bufler P.
Published: October 2002

Exhaled nitric oxide (eNO) is elevated in several inflammatory airway diseases and is significantly reduced by anti-inflammatory treatment with inhaled steroids. The aim of this randomized, open clinical trial was to evaluate eNO in relation to conventional lung function parameters at rest and after exercise during sequential changes of inhaled steroids in children with persistent asthma.

The study consisted of a 4 week run-in period, a 4 week washout phase and a randomized treatment period during which only one group was treated again with inhaled budesonide.

After run-in, eNO was reduced to normal values, and rose again during washout. In the patients randomized to steroid treatment, eNO was again decreased, whereas it remained unchanged in the untreated patients. Forced expiratory volume in one second and forced vital capacity at rest and after exercise improved significantly after run-in, but showed no difference after randomization. However there was a strong correlation of eNO with patient compliance.

Exhaled nitric oxide was able to differentiate between children briefly treated with or without steroids, the conventional lung-function variables however could not. In practice exhaled nitric oxide may thus be a valuable parameter to monitor adherence to steroids, but less suitable to describe physiologically relevant impairments of lung function.
Dyspnoea perception during clinical remission of atopic asthma
Authors: van den Toorn L.M. , Overbeek S.E. , Prins J-B. , Hoogsteden H.C. , De Jongste J.C.
Published: October 2002

Symptoms of atopic asthma often disappear around puberty. The authors recently demonstrated that this clinical remission is accompanied with ongoing airways inflammation in most subjects. The discrepancy between lack of symptoms and persistent airway inflammation suggests that perception of the symptoms is unclear. In the present study, young adults in clinical remission of atopic asthma assigned themselves a modified Borg score during methacholine and adenosine-5′-monophosphate induced bronchoconstriction. Borg scores of subjects in clinical remission were compared with those of symptomatic asthmatic subjects. A marked variation in the Borg scores at a 20% fall in the forced expiratory volume in one second was found. Significant differences in Borg scores between remission patients and asthmatics could not be detected.

It was concluded that perception of dyspnoea, induced with methacholine and adenosine challenge, is similar in young adults in clinical remission of atopic asthma compared to that of patients with symptomatic asthma. Hence, an unclear perception seems to be an unlikely explanation for the discrepancy between lack of symptoms and ongoing inflammation. Other factors, including both physical and psychological ones, may play a role in the apparent absence of symptoms, thereby potentially leading to undertreatment.
Asthma prevalence in children living in villages, cities and refugee camps in Palestine
Authors: El-Sharif N. , Abdeen Z. , Qasrawi R. , Moens G. , Nemery B.
Published: October 2002

Previous studies have suggested that asthma prevalence is generally lower in the Middle East than in more developed countries. The aim of this study was to investigate the prevalence and severity of asthma and asthma symptoms in schoolchildren in the Ramallah District in Palestine.

In the autumn of 2000, 3,382 schoolchildren aged 6–12 yrs were surveyed in 12 schools, using the International Study for Asthma and Allergies in Childhood (ISAAC)-phase III, parents-administered translated questionnaire.

The crude prevalence rates for “wheezing-ever”, “wheezing in the previous 12 months”, and “physician-diagnosed asthma” were 17.1, 8.8 and 9.4% respectively, with urban areas having higher prevalence rates than rural areas. Within urban areas, refugee camps had higher prevalence rates than cities. Yet, within the rural areas, the 12-month prevalence was lower in the deprived villages than other residences. Place of residence remained significant for asthma and asthma symptoms, after adjusting for sex, age, and place of birth.

To conclude, children from refugee camps appear to be at higher risk of asthma than children from neighbouring villages or cities. The prevalence of asthma and asthma symptoms in Palestine appears to be close to that of Jordan, but it is much lower than Israel, and lower than some other countries in the region, such as Kuwait and Saudi Arabia, and more developed countries. This initial study is a baseline for a study on lifestyle and environmental determinants for asthma among Palestinian children.
Analysis of factors that characterize health impairment in patients with chronic respiratory failure. Quality of Life in Chronic Respiratory Failure Group
Authors: Carone M , Bertolotti G , Anchisi F , Zotti AM , Donner CF , Jones PW
Published: October 2002

This study was designed to identify a core set of items that may characterize impaired health in chronic respiratory failure (CRF) since none of the questionnaires commonly used to measure impaired health in patients with CRF were developed for use in such patients. Questionnaire items, identified from several sources, were administered to 92 patients with stable severe chronic hypoxia or hypercapnia, together with physiological measures of disease severity, the Sickness Impact Profile (SIP) and the St George's Respiratory Questionnaire (SGRQ). Of the 152 items identified, only 28 correlated with patients' perceptions of overall health and were also independent of age, sex, disease or type of treatment and did not show floor or ceiling effects. Principal components analysis identified three specific factors: "daily activities", "cognitive function", and "invalidity". The total score for the whole 28-item set correlated with other measures of disease activity, including SGRQ (r = 0.86) and SIP (r = 0.70), but not spirometry. The interquartile range of the 28-item set was wider than that of the SGRQ or the SIP. This study characterized two areas of health impairment in chronic respiratory failure that had not previously been identified: effects of impaired cognitive function on daily life, and a sense of invalidity. The measurements properties of this 28-item set suggest that it may be a more discriminative instrument for patients with chronic respiratory failure than existing questionnaires.
Short-term and long-term epoprostenol (prostacyclin) therapy in pulmonary hypertension secondary to connective tissue diseases: results of a pilot study
Authors: Humbert M , Sanchez O , Fartoukh M , Jagot JL , Le Gall C , Sitbon O , Parent F , Simonneau G
Published: October 2002

Continuous intravenous epoprostenol improves exercise capacity, haemodynamics, and survival in severe primary pulmonary hypertension. Pulmonary hypertension can also be life-threatening in patients with connective tissue diseases. In a prospective open monocentre uncontrolled study, the effects of epoprostenol were evaluated in patients with severe pulmonary hypertension secondary to connective tissue diseases who were unresponsive to oral vasodilators (including calcium channel blockers) and continued to be in the New York Heart Association (NYHA) functional class III or IV despite conventional medical therapy. Seventeen patients received epoprostenol administered by a portable infusion pump associated with conventional therapy (oral anticoagulants, diuretics, supplemental oxygen). During the first six weeks of therapy, two (12%) patients died, of pulmonary oedema (n = 1) and severe sepsis (n = 1). In the fifteen remaining subjects, clinical and haemodynamic parameters improved significantly at six weeks. These patients were subsequently monitored for 80+/-48 (range 14-154) weeks after initiation of epoprostenol. Five (33%) patients died, of right heart failure (n = 2), severe sepsis (n = 2) or syncope (n = 1) and two patients were successfully transplanted 24 and 52 weeks after initiation of epoprostenol. Seven of the remaining eight patients had a persistent clinical improvement. Short-term epoprostenol therapy is effective in some patients with connective tissue diseases as demonstrated by better clinical status and haemodynamics at six weeks. However, this study reports several cases of early and late major complications including severe sepsis and pulmonary oedema. Additional information is needed to evaluate the benefit: risk ratio of long-term epoprostenol therapy in pulmonary hypertension secondary to connective tissue diseases.
A PROPOSED GEOPHYSICAL PROGRAM OF EXPLORATION FOR NEBRASKA AND THE DAKOTAS
Authors: Wilson John H.
Published: October 2002

The known geological information, particularly with reference to possible oil‐producing horizons, is discussed briefly. A method is proposed whereby the area is subjected to a reconnaissance seismic survey to determine the location of the major structural features, followed by other methods of successively higher resolving power in the favorable areas outlined by the reconnaissance.
A SIMPLIFIED CIRCUIT OF THE SEISMIC ELECTRIC METHOD AND ITS STEADY‐STATE SOLUTION
Authors: Slotnick M. M.
Published: October 2002

The Seismic Electric Effect gives rise to the problem of finding the steady state response of a circuit consisting of an inductance and a response of a circuit consisting of an inductance and a resistance of the form R+A cos cot (R>A) in series with a D.C. input. In this paper a solution is given, other than the one usually obtained by the method of successive approximations.
HISTORY OF THE GEOPHYSICAL EXPLORATION OF THE CAMERON MEADOWS DOME, CAMERON PARISH, LOUISIANA
Authors: McGuckin Glenn M.
Published: October 2002

In order to demonstrate the growth of our knowledge of a typical Gulf Coast salt dome concurrently with development of the science of geophysics, the successive application of various techniques to the exploration of the Cameron Meadows dome is described and illustrated. These methods were: mechanical refraction seismograph (1926); torsion balance (1927); electrical refraction seismograph (1928–29); early correlation reflection seismograph (1929); dip reflection seismograph (1933); special salt profiling refraction seismograph (1942); continuous correlation reflection seismograph (1942); gravity meter (1943.)
THE COMPUTATION OF OUTPUT DISTURBANCES FROM AMPLIFIERS FOR TRUE WAVELET INPUTS
Authors: Ricker Norman
Published: October 2002

A procedure for the computation of amplifier output forms for a true wavelet input form is outlined, and examples are given showing the manner in which these output forms may be determined from the known amplitude vs. frequency and phase vs. frequency characteristic curves of the amplifiers.
THERMODYNAMICS OF A GAS MIGRATING VERTICALLY THROUGH THE SEDIMENTARY COLUMN
Authors: Tripp R. Maurice
Published: October 2002

The gaseous hydrocarbons in a petroleum trap which escape to the surface by diffusing through the semi‐permeable geologic column are viewed thermodynamically to see if there might be an energy transfer involved that could produce a significant shift in the chemical, physical, or biologic equilibrium of the local environment.
EVALUATION OF NEW GEOPHYSICAL METHODS
Authors: Rust W. M.
Published: October 2002

Last March when you did me the honor of selecting me as President, I hoped I would have the privilege in my Presidential Address of telling part of the story of the contributions of geophysicists to the war effort, and of attempting some prophecies concerning the contributions of the war to geophysicists’ future prospecting efforts. For a time last fall, official optimism reached the point where it seemed that it would be possible to secure the release of some of the story; however, in December, I realized that someone else would have that pleasure. But, in looking forward to the day when we can turn away from our wartime activities, I have had my interest rekindled in an old problem, a problem which, with our present prospecting organizations, is the mutual responsibility of geophysicists, geologists and management. It is the problem of evaluating proposed new geophysical prospecting procedures and the somewhat simpler but still extremely difficult problem of evaluating modifications of existing methods.
THE REVIEW AND ANALYSIS OF SEISMIC DATA
Authors: Alcock E. D.
Published: October 2002

It is proposed that separate departments be established for the review and analysis of seismic data. The functions of these departments would be to review and submit independent interpretations of current seismic data, to review old seismic data in the light of new geological and geophysical developments, to compile and prepare regional seismic maps and to investigate areas in which seismic and geological data do not conform. This paper discusses the benefits to be expected from such a program, the source of man power, and the costs.
APPLICATION OF CONTINUOUS PROFILING TO REFRACTION SHOOTING
Authors: Barthelmes A. J.
Published: October 2002

A method of refraction shooting is developed for the purpose of investigating subsurface structures by utilizing the principle of continuous profiling now generally in use for detailed and more accurate reflection surveys. The basic assumptions and the general theory, which will allow individual depth determinations for all geophone locations, are discussed. The practical application is illustrated with sample records and cross sections. Several field techniques, as well as efficiency with regard to accuracy, production, and cost are discussed and analyzed.
CORRELATION OF REFRACTION SHOOTING
Authors: Gamburtsev G. A.
Published: October 2002

The theme of this paper is that refraction seismograph investigations making use of techniques and equipment similar to those used for reflection operations can be carried out much more effectively than the older refraction technique of using only first arrivals. The paper is of interest not only because it furnishes a measure of the development of the art in Russia before the war, but also because it contains some thought provoking assertions. The original paper is long (twenty‐two pages in original Russian, ten figures), since it contains a background of theoretical considerations, previous experience, and conceptions leading up to experiments and conclusions which are described, as well as discussion of the merits of the new developments in technique as compared with old technique. Essential features of the experiments, conclusions, and pertinent considerations are given below, without following the order or general arrangement of the original.
PUBLICATION OF GEOPHYSICAL CASE HISTORIES
Authors: Cortes Henry C.
Published: October 2002

As an introduction to the subject, I wish to review certain aspects pertaining to exploration and to the history of the Society of Exploration Geophysicists.
THE EFFECT OF VELOCITY OF DETONATION ON THE EFFICIENCY OF EXPLOSIVES USED IN SEISMIC PROSPECTING
Authors: Taylor J. , Morris G. , Richards T. C.
Published: October 2002

Field tests have shown that no significant difference in amplitude or frequency of the first arrivals of refracted waves at distances from 6,000 to 20,000 feet, is found from explosives having velocities of detonation in the range 7,500 to 1,100 metres/second or powers from 61% to 85% blasting gelatine. When a deflagrating explosive was employed there was only a very small decrease in the amplitude of the refracted wave.
VERTICAL VELOCITIES FROM REFLECTION SHOOTING
Authors: Gardner L. W.
Published: October 2002

Reflection seismograph observations supply a means of determining the average vertical velocity of seismic waves from the ground surface to the depth of any good reflecting horizon, through measurements of “angularity corrections.” Specially grouped arrangements of shot points and detectors are illustrated and described, which minimize error in making these measurements. Reflection seismograph observations using these arrangements were made at four locations where well velocity surveys were available. Comparison of results indicates that average vertical velocities good to within 3% can be obtained by this method, under favorable conditions.
GEOPHYSICAL HISTORY OF THE NORTH COLES LEVEE OIL FIELD, KERN COUNTY, CALIFORNIA
Authors: LeConte Joseph
Published: October 2002

The North Coles Levee oil field was discovered in November 1938. The location for the discovery well was based on data obtained from a reflection seismograph survey run early in the same year. A contour map, based on these reflection data, was prepared after several months of geophysical field work and interpretation. This map outlined the structure with reasonable accuracy as shown by comparing it with the present subsurface contour map constructed from electric‐log correlations in over one hundred wells which have been drilled in the field as of December 1946.
MULTICHANNEL PEN RECORDER FOR ELECTRICAL LOGGING OPERATIONS
Authors: Eisler J. D. , Silverman D.
Published: October 2002

Principle of operation, constructional details and performance of a servo‐mechanism type pen recorder are described. The recorder comprises two independent channels of servo‐amplifier and motor, each capable of moving an inking pen in a rectilinear fashion across a chart moving proportionally to the bore hole depth traversed by an electrode array. The speed and resolution of the recorder is more than adequate for electrical logging requirements. The recorder is capable of recording both d.-c. and a.-c. signals.
MULTIPLE‐REFLECTION EVIDENCE
Authors: Waterman Joseph C.
Published: October 2002

A rather interesting example of multiple reflections was found in one area in Madera County on the east side of the San Joaquin Valley of California. In this region the top of the basement complex is an excellent reflecting horizon, and the determination of the depth of the basement was confirmed by well data.
NOTES ON MULTIPLE REFLECTIONS
Authors: Walling Dean
Published: October 2002

Since the inception of the reflection seismograph, apparent reflections have been observed from time to time, which for one reason or another, do not meet the requirements of normal reflections from interfaces in the sedimentary section. Various theories have served to explain and allow the proper interpretation of a large percentage of these spurious energies. Among these is the multiple‐reflection theory which has proven to be applicable in many cases.
MULTIPLE REFLECTIONS OF SEISMIC ENERGY
Authors: Hansen Raul F. , Johnson Curtis H.
Published: October 2002

This paper is a report of observations of multiple reflections in seismograph work in Argentina, of successful methods of identifying them, and of unsuccessful attempts to eliminate them. The paper begins with generalizations regarding the expectancy of multiples and develops geometrically (using straight‐line paths) the relation between multiples and their primary reflections for the cases of multiple reflection between a horizon and the surface and between two horizons, as regards time of reflection, dip and average velocity. The importance of a sharp reflecting contrast at the surface is emphasized, and it is concluded that the base of weathering may be more important in the formation of multiples than the surface of the earth. Early observations of multiple reflections from a volcanic flow and from a shallow basement are described. Other areas showed discordant data on the seismograms and cross sections, which, if due to multiples, could only be caused by multiple reflections from good sedimentary reflectors. In these areas a method for identifying both types of multiple reflections by their low average velocity as obtained by shooting reflection velocity‐profiles was developed, the work being facilitated by considerable knowledge of velocity and section from previous refraction shooting. Though this reflection velocity‐profile method is considered essential to positive and detailed identification of multiples, two methods of multiple identification using ΔT variations in continuous profiling are described and the results of considerable work with one of them are reported in graphical form, showing not only a separation of multiple from real reflections but also the determination of the true velocity‐depth function by means of the real reflections so segregated. Experiments are briefly described in which variations in size or depth of shot and variations in filters were not effective in reducing the ratio of multiple reflections to real reflections. The paper closes with suggestions for identifying multiple reflections by their abnormal curvatures in discontinuous, symmetrical‐spread dip shooting, and for using primitive qualitative methods where the topography or subsurface are not suited to the quantitative methods developed here.
A NOTE ON TERRAIN CORRECTIONS
Authors: Bickel H. C.
Published: October 2002

A means is presented for empirically determining the areal extent within which terrain corrections are appreciable in any given area. An example is given to show how the same device can be extended to decrease the labor of making terrain corrections in extremely rugged areas.
EXPLOSIVES ACCIDENTS ON GEOPHYSICAL CREWS
Authors: Hanahen P. M.
Published: October 2002

This paper discusses accidents caused by the improper handling of explosives by geophysical crews. Since the war, geophysical companies have been experimenting with the use of aluminum loading poles. Premature ignitions have been caused by the electric current generated by the galvanic cell formed by the aluminum loading poles, the alkaline mud, and the steel casing of the shot hole. This paper gives a brief description of tests that have been made on the amount of electric current generated by such a cell. Static electricity has been blamed for the ignition of detonators while the primer was being prepared. This paper briefly summarizes the experiments conducted by the Bureau of Mines and discussed in Report of Investigations 3852 “Sensitivity of Explosive to Initiation by Electrostatic Discharges” and the probabilities that static electricity caused premature detonations. From the data discussed in this paper, the author concludes that there is a need for establishing a set of standard safety regulations in the geophysical industry, and that before any new piece of equipment, such as aluminum loading poles, is introduced, the problem should be studied to insure that a new hazard is not introduced. Only a safe geophysical crew operates economically and efficiently, and, in order to promote and maintain efficient operations, geophysical companies must not revert to the unsafe practices used prior to the war.
RESIDUAL GRAVITY IN THEORY AND PRACTICE
Authors: Griffin W. Raymond
Published: October 2002

A precise definition of residual gravity is given and in a form most suitable for numerical application. Some pains are taken to show that the residual‐gravity picture one obtains depends on the method used in obtaining it and that there are many ways in which this may be done. Several examples from actual work on developed oil fields are given in the form of figures and maps to bear out the above statement. Conclusions are drawn as to the relative order of sensitivity of several factors entering into the computations in determining a given residual picture. Factors considered in this paper are (1) size of unit figure, (2) kind (or shape) of unit figure, (3) density of reference net; that is, number of reference points per unit area, and (4) sensitivity of reference points to lateral displacement on gravity map.
ON THE STRATIFICATION OF THE EARTH’S CRUST ACCORDING TO SEISMIC STUDIES OF A LARGE EXPLOSION AND OF EARTHQUAKES
Authors: Mintrop L.
Published: October 2002

The analysis of the seismograms of an explosion of 4,000 tons (about 10 million pounds) of munitions piled up in tunnels 50 feet below the surface of the rocky island of Heligoland in the North Sea near Hamburg, Germany, and of a great number of natural earthquakes, especially the disastrous shock at Messina (Italy) led to the discovery of a number of formations unknown heretofore down to a depth of several hundred kilometers. At depths from 110 to 118 km a plastic layer occurs which seems to represent a belt around the globe. At a depth of 183 km the melting point of a material with very high wave‐velocity is reached. These findings are in accordance with the determination of the depth of Isostatic Surface by Hayford and Helmert (both in 1909) from deflections of the vertical and/or from gravity anomalies (113 and 118 km, respectively). Qualitatively, the results are also in accordance with the assumption of Gutenberg and Richter, based on the measurement of the amplitudes of the first recorded waves from numerous earthquakes with different epicenter distances and with different depths, that at a depth of 80 to 100 km the melting point of the material has been reached.
COMPLICATIONS IN BASEMENT REFLECTION CORRELATION
Authors: Cortright W. D.
Published: October 2002

This paper shows by illustration how the top of basement reflection character correlation may be misleading, and suggests some geologic conditions which may have a bearing on the problem. Local migration vertically of the typical “Z” basement reflection, although a disturbing factor, does not prevent the extended use of this reflecting band as a basis for regional mapping of the top of basement horizon.
INDUCTIVE COUPLING OF A HOMOGENEOUS GROUND WITH A VERTICAL COIL
Authors: Belluigi A.
Published: October 2002

The problem of the “magnetic pulsating pole” is examined from an analytical viewpoint and an integral solution is reached with the use of Hankel’s Integrals. However, a complete explanation was derived only with respect to the horizontal component of the magnetic field. In addition the problem of the “pulsating magnetic dipole” is also explored and similarly a complete explanation is derived only for the horizontal component. The application of the results of these analyses to field prospecting methods is also discussed.
THE UNITED NATIONS SCIENTIFIC CONFERENCE ON THE CONSERVATION AND UTILIZATION OF RESOURCES
Authors: Hubbert M. King
Published: October 2002

During the three‐week period August 17 to September 6, 1949, there was held at the United Nations headquarters at Lake Success, New York, an international scientific conference dealing with all aspects of the utilization and conservation of natural resources. The conference was authorized by a resolution of the Economic and Social Council in March 1947, who wisely stipulated that it should be limited strictly to an exchange of information, ideas and experience, and should not pass resolutions or otherwise advise or commit member governments. It was to be a scientific rather than a political conference.
A GRAPHICAL METHOD FOR THE INTERPRETATION OF REFRACTION PROFILE DATA
Authors: Slotnick M. M.
Published: October 2002

A graphical method for interpreting refraction profiles is presented by means of a complete solution of a numerical example.
THE STATE OF SEISMIC PROSPECTING
Authors: Gilmour Andrew
Published: October 2002

The application of physics to the search for minerals and especially for petroleum began in earnest after the first World War. As Weatherby has stated in his excellent paper on The History and Development of Seismic Prospecting (1940) “the stage had been carefully set and the players were ready to perform their new roles as prospectors.” Minthrop in Germany and Karcher, Hasemann, Eckhardt, and McCullom in this country were considering the use of artificial seismic waves in finding oil‐bearing structure. Ferdinand Suess in Hungary was building Eötvös torsion balances and the Askania Company in Germany was constructing torsion balances and magnetometers.
PULSE PROPAGATION IN TWO SPATIAL DIMENSIONS
Authors: Dix C. Hewitt
Published: October 2002

Mathematicians have known for many years that two dimensional wave propagation is very different from one (plane) or three (spherical) dimensional propagation. Plane and spherical pulses can be propagated without change of form—an impossibility for cylindrical waves. The object of the present paper is to clarify the physical picture involved. It is shown that for any initially given axially symmetric disturbance, confined between two concentric circular cylinders, if energy is subsequently transmitted outwards then it is also always subsequently transmitted inwards. The only possible case of no inward transmission is that of no transmission. Thus for a two dimensional pulse propagation every part of the pulse is being continually split at each instant, part traveling inwards and part outwards. Only the very simplest problem is solved in this paper. However the process of tail (coda) formation is now clear for this case.
FAULT INTERPRETATION FROM SEISMIC DATA IN SOUTHWEST TEXAS
Authors: Quarles Miller
Published: October 2002

Many of the oil‐bearing structures around the Gulf Coast and in Southwest Texas are found along a distinctive type of low‐angle normal faulting. Reflection sesimograph shooting across the faults gives normal information on the downthrown side but produces two types of distorted and misleading data below the fault plane on the upthrown side. One type of distortion gives a time lag up to 100 milliseconds to reflections plotted vertically below the upper limit of the fault plane. If this time lag is not recognized, the fault may be located as far as a mile from its true position. The second type of distortion below the fault plane is an apparent increase in dip toward the fault plane in the deeper beds. The magnitude may be great enough to cause some reflecting horizons on the upthrown side of the fault to be plotted actually deeper than those on the downthrown side. This could readily cause error in locating the fault and determining the magnitude and direction of throw. The first “drop” type of distortion is explained by a refraction pattern downward along a portion of the fault plane before the energy is reflected back from the recognized interface. The second “increased dip” type of distortion may be either a reflection time lag through the gouge zone of the fault or a refraction across the fault plane and a reflection from the known interface.
QUANTITATIVE INTERPRETATION OF VERTICAL MAGNETIC ANOMALIES OVER VEINS
Authors: Cook Kenneth L.
Published: October 2002

By using ordinary magnetic induction methods of analysis, Haalck, Heiland, and others have developed formulas which express the magnetic anomaly over a vertical or inclined vein of tabular shape as a function of the susceptibility, dimensions, shape, and disposition of the vein, and of the strength and direction of the earth’s magnetic field. On the basis of these fundamental formulas, other formulas for the vertical component of the magnetic field are derived in the present paper for such veins in intermediate northern magnetic latitudes. Special emphasis is given to the orientation of the veins relative to the magnetic north direction. Several families of vertical magnetic intensity curves for veins with different strikes and dips are given. All theoretical curves for veins striking magnetic north are plotted in terms of a parametric unit so that, once plotted, they can be used repeatedly in different districts, provided a proper multiplying factor is chosen for the observed curve. The importance of the transverse horizontal magnetization effect under certain conditions of orientation is demonstrated. It is shown mathematically that small vertical magnetic anomalies are to be expected for thin veins striking east and dipping south at an angle equal to, or approximately equal to, the complement of the angle of magnetic inclination.
SEISMIC REFRACTION WITH VARIABLE VELOCITY
Authors: Goguel Jean M.
Published: October 2002

The results of an investigation of methods of interpreting and calculating the propagation of seismic waves with variable velocity in contrast to an assumed constant velocity is presented. One of the major purposes of this study is to establish a calculation method for use in seismic refraction work that can be applied to existing types of alluvia and similar geologic formations. In addition to presenting the necessary tables and graphs used for such computations, two examples from actual field experience are presented.
GROUND ROLL COUPLING TO ATMOSPHERIC COMPRESSIONAL WAVES
Authors: Press Frank , Ewing Maurice
Published: October 2002

A theoretical treatment of ground roll originating from air shots and hole shots is given. It is shown that coupling of ground roll to compressional waves in the atmosphere exists for both air shots and hole shots. Experimental data obtained in the field are in excellent agreement with the theoretical results; namely, that the effective coupling exists for surface waves whose phase velocity is equal to the speed of sound in air. In regions where Rayleigh wave velocities vary with period due to layering in such a way that they are less than the speed of sound in air for short periods and exceed this value for longer periods, this coupling gives rise to a unique surface wave pattern on seismic records. It is shown that body wave and surface wave character is almost independent of charge elevation in the range from 0 (on the ground) to 30 feet. In a reciprocal manner ground roll from hole shots was recorded with air microphones as predicted by the theory.
HYDROSTATIC LEVEL FOR ELEVATION SURVEYING
Authors: Crumrine Kenneth C. , Palmer John E.
Published: October 2002

A hydrostatic level for elevation surveying has been developed which indicates differences in elevation by measuring the head of a column of water. It is essentially a differential pressure gauge connected by a length of water‐filled plastic tubing to a water reservoir. The instrument is described and the results of a field test on 73 miles of traverse are given. A probable error of about 6 cm and a maximum error of 33 cm were found for closed loops of 3 to 5 miles after proration of closure errors. On unsupported traverses of 3 to 5 miles, application of a temperature correction appeared desirable and resulted in a probable error of about 10 cm and a maximum error of 52 cm. The range of the instrument is from minus to plus 10 meters and the least count is 2 cm. It is read to the nearest centimeter.
GEOPHYSICAL EVALUATION OF THE MARFA BASIN OF TEXAS
Authors: Wilson John H.
Published: October 2002

Information on past geophysical investigations of the Marfa Basin of Texas is given. Special problems are involved in the application of geophysical methods.
THE WORLD‐WIDE GRAVITY PROGRAM OF THE MAPPING AND CHARTING RESEARCH LABORATORY OF OHIO STATE UNIVERSITY
Authors: Heiskanen W.
Published: October 2002

This paper deals with the geodetic applications of the gravity method. Gravity anomalies permit the absolute undulations of the geoid and the absolute deflections of the vertical to be determined. In turn, these, together with astronomical observations, form the basis for a World Geodetic System for the control of small scale maps beginning with the scale 1:100,000. They serve also, together with existing triangulations, for the correction of the dimensions of the reference ellipsoid. Additional gravity surveys are needed in order to obtain these and other minor objectives. Cooperation among scientists and agencies of different countries concerned with these problems is a prerequisite for the success of this world‐wide program.