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In this paper we derive the equivalent line mechanism for the case of low frequency monopole sources and receivers in boreholes. This line mechanism is equal to a point mechanism which propagates at the speed of tube waves. This was first recognized and treated in White and Sengbush (Geophysics, 28, p. 1001-1019). The resulting far-field radiation (or receptivity) pattern is a generalization of that published by Lee and Balch (Geophysics, 47, p 1308-1314) in that it addresses the case where the shear velocity is close to or slower than the tube wave speed. The equivalent moving point representation can be incorporated into existing modeling codes, thereby avoiding the need to directly model the borehole. Furthermore, realistic borehole environments (such as casing, caliper logs, curved welk, anisotropic formations, etc) can be incorporated into the equivalent representation.

We studied the pulmonary response of adult rats to erythrocyte (RBC) and RBC lysate insufflation to define the mechanism of RBC insufflation-induced protection against oxygen toxicity. Tracheal insufflation of 1 ml RBC (75%) or RBC lysate induced an intense pulmonary inflammatory response. Within 24 h of oxygen exposure, greater than 95% of insufflated RBCs was hemolyzed. The cell-free fraction of alveolar lavage fluids from RBC- or RBC lysate-insufflated rats had similar capacity in protecting endothelial cells against H2O2 cytotoxicity. However, RBC insufflation but not RBC lysate insufflation, protected rats against oxygen toxicity. There was marked erythrophagocytosis by alveolar macrophages of RBC-insufflated rats. Insufflation of RBCs, but not RBC lysate, resulted in production of tumor necrosis factor and interleukin 1, which could be recovered by bronchoalveolar lavages. When rats were insufflated with a combination of RBC lysate and cytokines at dosages within the range of cytokine levels achievable in alveolar lavage fluids by RBC insufflation, they became tolerant to oxygen. These results suggest that endogenously produced tumor necrosis factor and interleukin-1 as a result of RBC insufflation may play an important role in RBC insufflation-induced oxygen tolerance.

Two hundred twenty-three patients were enrolled on this randomized Phase III trial testing the value of late consolidative involved-field radiation therapy in the treatment of limited-stage small cell lung cancer (SCLC). Patients were treated with induction chemotherapy consisting of alternating cycles of procarbazine, vincristine, lomustine, and cyclophosphamide (POCC) and etoposide, doxorubicin, and methotrexate (VAM) for 6 to 9 months. Responding patients were then randomized at 6 or 9 months to chemotherapy alone or to involved-field radiation therapy. All partial and complete responders received prophylactic cranial irradiation. Of the 180 eligible and evaluable patients, 80 (44%) achieved a complete response and 39 (22%) achieved a partial response (overall rate of response, 66%). Actuarial median survival time was 11.6 months, with 16% of patients surviving 2 years and 11% surviving 5 years. Forty-eight patients were randomized to chemotherapy alone (24 patients) versus chemotherapy plus involved-field radiation therapy (24 patients). There were no significant differences in time to progression or survival between those patients receiving or not receiving involved-field radiation therapy. The thorax was the site of first relapse in 58% of patients randomized to chemotherapy alone versus 29% in patients randomized to chemotherapy plus involved-field radiation therapy (P equals 0.042). The major acute toxicity was reversible myelosuppression, and the major late toxicity was chronic central nervous system dysfunction. The authors conclude that the addition of late consolidative radiation therapy to induction chemotherapy in the treatment of limited-stage SCLC is well tolerated and improves local control, but does not improve time to progression or rates of survival.

A wide spectrum of hepatic lesions has been reported in AIDS, but it is not known whether the changes are related to the presence of human immunodeficiency virus type 1 (HIV-1). Therefore, we examined liver sections from 15 consecutively autopsied patients with AIDS for the presence of HIV-1 antigens p24 (core) and gp41 (envelope) by the avidin-biotin-peroxidase complex method using monoclonal antibodies. The most common histologic abnormalities noted were steatosis, portal inflammation, Kupffer cell hyperplasia, and focal hepatocellular and bile duct damage. Intra-hepatic opportunistic organisms were detected in six of 15 (40%) cases, with Mycobacterium avium-intracellulare being the commonest (four cases). Immunoreactivity for HIV-1 antigens was demonstrated in 12 of 15 cases (80%), with staining limited to Kupffer cells and other mononuclear cells characterized by a lymphoid morphology. Approximately the same number and type of cells were stained with both monoclonal antibodies and did not bear any relation to the degree of histologic abnormalities nor to the presence of opportunistic infections. The data suggest that some pathologic changes in AIDS livers are more likely the result of an indirect effect mediated by infected resident and circulating mononuclear cells than a direct cytopathic effect of HIV-1.

At the time of initial diagnosis, testicular malignancy is usually limited to the testicle and infradiaphragmatic lymph nodes. Metastases initially follow the retroperitoneal lymph channels and subsequently extend to the supradiphragmatic lymph nodes in the mediastinum and supraclavicular fossa. Testicular metastases to the pericardium are rare and usually asymptomatic. These lesions are most commonly identified at autopsy; therefore, the actual incidence is unknown. The authors report a 32-year-old man with testicular carcinoma, who developed asymptomatic pericardial metastases without concomitant supradiaphragmatic nodal or pulmonary metastases. They review the efficacy of echocardiography in diagnosis and follow up or pericardial metastasis.

Clinical simulations, depictions of real-life patient care situations, have been used extensively in medical education. This study determined the criterion validity of a computer-based simulation which permits natural language interface and runs interactively with videotape to be fair to good (K = .61).

Tracheal insufflation of tumor necrosis factor (TNF) enhances pulmonary antioxidant enzyme activities and protects rats against oxygen toxicity (J. Appl. Physiol. 68: 1211–1219, 1990). We now report that tracheal insufflation of TNF selectively induced pulmonary Mn-superoxide dismutase (SOD) mRNA in normoxia- and hyperoxia-exposed rats, leading to increased amounts of Mn-SOD specific protein and enzyme activity. Tracheal insufflation of TNF had no effect on the levels of pulmonary Cu,Zn-SOD mRNA or specific protein. Hyperoxia alone also selectively induced pulmonary Mn-SOD mRNA. However, the hyperoxia-induced increase in Mn-SOD mRNA was not associated with an increase in Mn-SOD specific protein or enzyme activity. The results suggest that the increased pulmonary Mn-SOD in TNF-insufflated rats may contribute to the TNF-induced protection against oxygen toxicity.

A follow-up total-body I-131 scan in a patient with follicular thyroid carcinoma demonstrated radionuclide accumulation in the right hemithorax. Originally thought to be pulmonary metastatic thyroid carcinoma, the uptake region proved to be intrathoracic gastric mucosa. The patient had been treated for squamous cell esophageal carcinoma by esophagogastrostomy reconstruction with gastric pull-up. This unusual imaging pattern could have been interpreted as metastatic disease in the absence of complete patient records, an appreciation of normal gastric concentration patterns of I-131, and corroborative imaging study analysis.

Tracheal insufflation of tumor necrosis factor (TNF; 5 micrograms or 1.2 x 10(5) U) markedly enhanced the survival of adult rats exposed to 100% O2: 12 of 17 rats (71%) survived for greater than 11 days, whereas 30 of 30 control (Hanks' balanced salt solution) insufflated rats (100%) died within 3 days of O2 exposure. Insufflation of gamma-interferon (5 micrograms) or intraperitoneal injection of up to 40 micrograms TNF did not afford any protection. At 55 h after O2 exposure, TNF-insufflated rats showed less pulmonary edema, as determined by the extravascular lung water content-to-bloodless lung dry weigh ratio and less alveolar capillary leak as determined by the protein content in the bronchoalveolar lavage fluid, than control insufflated rats similarly exposed. This protection against O2 toxicity by TNF insufflation was associated with increased lung superoxide dismutase, catalase, and glutathione peroxidase activities. The enhancement of lung antioxidant enzyme activities was noted at 55 h of O2 exposure, when control animals began to die of O2 toxicity. This temporal relationship suggests that TNF-induced increase in antioxidant enzyme activities contributes, at least in part, to the observed protection.

1. Cultured mesenchymal cells respond to hyperoxic (hyper-O2) stress with increased cell flattening/substrate adhesion and overall 47-69% reductions in total matrix-associated (i.e. saponin-resistant [SAP fraction]) protein. 2. Electrophoretic analysis revealed a selective hyper-O2-related 2.7- to 4-fold increase in SAP and cytoskeletal fraction deposition of the protein p45 beginning early (within 12 hr) after initial exposure of porcine endothelial cells to hyper-O2 and increasing over a 48 hr period. 3. p45 consisted of 8 distinct isoforms differing only in pI; hyper-O2-augmented matrix deposition of 3. p45 consisted of 8 distinct isoforms differing only in pI; hyper-02-augmented matrix deposition of p45 involved all 8 isoforms with the more basic subtypes exhibiting slightly greater net increases. 4. Both the specificity and time course of p45 induction, relative to the onset of hyper-O2 cytoarchitectural remodeling, indicate that p45 up-regulation constitutes an early aspect of the hyper-O2 adaptive response.

Surface‐to‐borehole seismic waves have been used from the early days of seismic exploration [B. McCollum and W. W. LaRue, Bull. AAPG 15 (11), (12) (1931)]. As long as the arrival time of the most direct compressional wave was the only observation, a geophone hanging on a cable sufficed, and it did not matter that the ensuing signal was dominated by acoustic waves in the mud column. Mathematical modeling and field measurements have guided the development of geophones that are pressed against the hole wall, greatly reducing sensitivity to these mud‐borne waves and more faithfully measuring the three components of motion in the solid around the hole. Analysis and measurements also show that shear and compressional waves passing the borehole create pressure signals in the mud column. Pressure detectors have the advantage that they do not need to be clamped, but this means that suppression of the mud‐borne signals must be achieved in some other way. Borehole sources that act by way of volume change create stro...

The term underground sound is meant to encompass the instrumentation, observational methods, and interpretive techniques that have been developed for the utilization of seismic waves in the earth, quite analogous to the field of underwater sound. Wave propagation in the shallow crust of the earth is more complex than waves in water, simply because of the presence of shear waves in addition to compressional waves. Either type of wave is severely attenuated in traveling through earth materials, compared with similar distances of travel through the ocean. Finally, many rocks are anisotropic in average properties, resulting in further complexities. In exploration for petroleum, remarkably detailed images of geologic boundaries have been achieved by processing observed data so as to enhance reflected compressional waves and suppress shear waves and reverberations. Alternatively, shear‐wave reflections can be observed by using a vibratory source which radiates strong shear waves and processing the data so as to...

Radiation of elastic waves from a point force or from a localized torque into a transversely isotropic medium has been formulated in terms of displacement potentials, and transient waveforms have been computed by numerical Fourier inversion. For isotropic sandstone, this procedure yields P‐ and S‐wave pulses whose arrival times and magnitudes agree with theory. For a range of anisotropic rocks, arrival times of quasi‐P‐waves and quasi‐S‐waves agree with asymptotic theory. For extreme anisotropy, some quasi‐S‐wave pulses arrive at times which are not predicted by asymptotic theory. Magnitudes have not been compared with results of asymptotic theory, but decrease with distance appears to be in agreement. This Fourier inversion method gives near‐source changes in waveform which are not obtainable from the asymptotic theory.

The five elastic coefficients which characterize a transversely isotropic medium have been measured for the Pierre Shale. The first-arrival times deduced from two closely spaced vertical seismic profiles provide values of magnitude and direction of the phase velocity at a given depth for different locations of the sources. From these velocities, we can estimate the five elastic coefficients by assuming that the P- and SV-wave velocities have only a small dependence on the angle of propagation. On the other hand, it is shown that the accuracy in the difference between the directions of propagation and particle motion is not sufficient to determine the anisotropy. This work was industrially sponsored through the Integrated Geophysics Project.

White (1983), among others, has shown that the propagation and attenuation of Stoneley waves in a fluid‐filled borehole contain information on the porosity and permeability of the surrounding formation. Prior to extracting permeability from attenuation, the correct viscous loss of Stoneley waves in a borehole in a nonporous medium must be completely understood. With this motivation in mind, the purpose of this paper is to derive the viscous loss due to drag at the wall of a borehole from the exactly solvable case of a perfectly cylindrical borehole in an elastic, nonporous formation filled with a fluid that is viscous in shear. Thus the fluid pressure and fluid motion in the small but critical region near the fluid‐solid interface can be calculated. We have obtained dispersion and attenuation of trapped waves and tube waves, but here we report only on tube waves.

Using skin-surface sensors, transcutaneous oxygen tension (Tc Po2) has been measured at the edges of ulcers and at control sites proximal to wounds on the same legs. Tc Po2 at 43°C at the edges of venous ulcers was found to be significantly different ( P < 0.003) from that of arterial and mixed arteriovenous ulcers ( P < 0.05) respectively. Tc Po2 on healed skin was higher than at any wound edge. At this temperature Tc Po2 was also found to be significantly different ( P < 0.001) on the intact skin of patients with venous disease when compared with measurements at identical sites on healthy controls. In the same group, these Tc Po2 values increased with dependency. By contrast, at 37°C Tc Po2 was no different between groups ( P < 0.10), nor did it alter with position. This protocol adopted for investigating ulcers enables a quantitative distinction to be made between ulcers of different aetiologies. The differences in Tc Po2 between different ulcers and healed skin support the fibrin cuff mechanism which has been suggested as the cause of venous ulceration.

The neurological complications of Borrelia burgdorferi infection have only recently been recognised in the United Kingdom. Eight cases are reported which were all contracted in the New Forest area of Hampshire. The majority of patients had Bannwarth's syndrome though meningism and parenchymal lesions also occurred. All patients made a virtually complete neurological recovery in contrast to some patients with Lyme disease.

A comparison was made of the circular dichroism (C.D.) spectra of Chlorella, Euglena, and Anacystis cells and thylakoids. Analyses of the spectra reveal that these C.D. bands are similar to those observed previously in whole spinach choloroplasts and subchloroplast particles. C.D. spectra of Euglena chloroplasts show bands at longer wavelengths than previously reported. From comparisons of circular dichroism spectra and fine structure, it was concluded that: (a) bands seen in circular dichroism spectra were not the result of light scattering from thylakoid membranes; and (b) bands seen in the C.D. spectra of nonmembranous systems (previously reported) could account for circular dichroism of algae. We also concluded that comparisons would have to be made with model systems in order to correct for effects of absorption flattening, concentration obscuring, and differential light scattering of membranous systems.

The mathematical description of fluid-saturated rocks developed by Biot and others has been applied to earthquake dynamics, providing a quantitative relation between rock properties and some seismic precursors which are being widely evaluated as a basis for earthquake prediction. This relation is a quantitative expression of the dilatancy-diffusion model of earthquake dynamics, with one significant refinement in concept: the dilatancy here is a consequence of the nonlinear stress-strain curve for rocks, rather than a result of crack formation as the rock approaches failure. Solution gas plays a key role. The computed imbalance in fluid pressure following the stress-release by an earthquake provides a starting point for describing the time sequence and spatial migration of aftershocks.

Expressions are derived for the acoustic pressure in a fluid-filled borehole due to the passage of plane compressional or shear waves propagating in a porous and permeable medium. The derivation is based on a quasistatic description, yielding results applicable at low frequencies. Computations for a plausible sandstone (with porosity of 0.21 and permeability of 300 millidarcies) show accoustic pressure to be a surprisingly distortion-free version of the stress waveform in a plane compressional wave. For a plane shear wave, the pressure waveform is visibly distorted.

Oral acyclovir at a dose of 800 mg five times daily for seven days was compared with placebo in a randomised double blind trial conducted at three centres in the United Kingdom. The study group comprised 205 elderly immune competent patients suffering from herpes zoster who were entered within 72 hours of the onset of rash. Acyclovir significantly reduced the times to arrest of new lesion formation (p = 0.005), loss of vesicles (p less than 0.001), and full crusting (p = 0.02) in those patients entered within 48 hours of the onset of rash. In addition, there was a significant reduction in pain during treatment with acyclovir as compared with placebo (p = 0.008). Of the patients with severe pain on entry, 40% (10/25) of those treated with acyclovir had no or only mild pain at the end of treatment, whereas in the placebo group all had residual moderate or severe pain (p less than 0.001). No clinically important adverse effects of acyclovir were reported. Oral acyclovir may modify acute herpes zoster and reduce pain.

SummaryThe 30-item General Health Questionnaire (GHQ) (Goldberg, 1972) was administered to 196 consecutive new dermatology out-patients and 40 consecutive admissions to dermatology beds. Thirty per cent of the outpatients and 60 per cent of the in-patients obtained high scores, while half the high scorers in each group scored high on the Wakefield Self-Assessment Depression Scale (Snaith et al, 1971). These findings suggest that dermatology out-patients have a higher prevalence of psychiatric disorder than the general population, and dermatology in-patients a higher prevalence than general medical in-patients.High GHQ scores were associated with (a) diagnoses of acne, eczema, psoriasis or alopecia; with (b) extensive lesions on exposed parts of the body; and with (c) the use of high potency topical steroid. We indicate other areas that might be profitably explored in a full-scale study.

Acoustic waveform measurements in boreholes have important applications in fracture hydrology and radioactive waste disposal, but ambiguities in existing interpretation techniques remain a problem. We have addressed the problem by using residue theory to predict the relative excitation of various modes contained in experimental waveforms. A plane‐geometry model involving a layer of fluid between two elastic half‐spaces is shown to provide velocity dispersion curves for propagating modes that are very similar to those for the fluid‐filled borehole. We use the plane‐geometry model to illustrate the effects of the confined borehole fluid on surface and body waves traveling along the borehole in the elastic solid. We also computed excitation functions for some of the lowest‐order symmetric modes, calculated the time‐domain response of the trapped modes following the shear head waves, and compared them to waveforms recorded in boreholes through several homogeneous formations. The insight into the mode composition of the experimental waveforms obtained in these formations is used to construct amplitude logs that should be especially sensitive to variations in the presence of fluid‐filled fractures in the borehole wall. Initial tests show the technique is most successful when the waveform is dominated by the fundamental tube wave, and yet frequencies remain relatively high. The model analysis indicates these conditions can only be obtained when the borehole diameter is not much larger than that of the logging tool.

Calculations for an unconsolidated sand with partial gas saturation show a 20 percent increase in compressional wave velocity between 1 and 100 hz and attenuation of 27 db/1000 ft at 31 hz and 82 db/1000 ft at 123 hz. Shear velocity and attenuation are not affected. Fluid‐flow waves are shown to be responsible for the dispersion and attenuation at low frequencies; relations are derived by extending Gassmann’s viewpoint to include coupling between fluid‐flow waves and seismic body waves. This appears to be an important loss mechanism for heterogeneous porous rocks.

The mechanism of low-frequency Borehole Coupling from the literature is here applied to a borehole of non-uniform radius. It is noted that in addition to the pressure signal in a fluid-filled borehole coincident with the passage of an external plane compressional wave, there are waves created at any change in radius which arrive later as coherent noise. This is illustrated first with a single step-change in radius. An example using the caliper log from an oil well shows that these delayed waves create a noise train of substantial amplitude relative to the direct compressional wave. It is pointed out that a down-hole pressure source will radiate a noise train due to caliper changes which will follow the direct compressional wave with exactly the same waveform as that encountered in Borehole Coupling.

The synthesis of a series of Polybis(arylamino)phosphazenes is described. The polymers usually were prepared by treatment of polydichlorophosphazene in benzene–tetrahydrofuran with arylamines/triethylamine at reflux for 48–144 hr. The polymers, having viscosities of 0.3–1.4dl/g, are essentially free of active chlorine sites, as shown by elemental analysis and their longterm hydrolytic stability. Thermal analysis revealed glass transition temperatures between 53 and 105°C and decomposition temperatures between 243 and 266°C. Analysis by differential scanning calorimetry revealed no first-order endothermic transitions. For comparison with the arylamino polymers, polydiethylaminophenylaminophosphazene, polybis(benzylamino)phosphazene, and polybis(β-phenethylamino)phosphazene were prepared and are described.

Experimental investigations of frost deposition under forced convection conditions have shown that in most cases heat and mass transfer rates become constant after an initial transient period. It is shown that, in such cases, approximately half of the mass transfer from a humid air stream to a frost layer diffuses inward, condenses and increases the density of the frost. The other half is deposited at the surface and increases the thickness of the layer. Approximate expressions for density and thickness of the frost layer are derived and compared with data from the literature and also with experimental work reported in this paper. The correlations are shown to work well for a broad range of experimental conditions.

A treatment of waves in a viscoelastic gel filling a rigid cylindrical cavity shows that, when the wall of the cavity executes axial motion, resonances occur at certain frequencies characterized by large displacements and high energy loss. Application of these results to shear waves in a ‘‘porous solid’’ consisting of parallel tubes in an elastic skeleton produces attenuation that is orders of magnitude greater for gel saturation than for fluid saturation. The mechanism of energy loss is applied to a more realistic pore geometry by repeating the derivation of the Biot theory with addition of a small shear rigidity to the saturating phase. Calculations show that attenuation and dispersion are greatly increased for compressional waves, type‐II dilatational waves, and shear waves. Even so, the computed decrements are not substantially larger than the decrements measured for typical porous rocks.

Many measurements have been made on fluid‐saturated porous rods executing extensional, flexural, and torsional motion. Measurements for extensional and flexural motion yield a loss parameter for Young's modulus waves [Formula: see text], and the measurement for torsional motion yields [Formula: see text] for shear waves. [Formula: see text] has then been calculated for compressional waves in bulk rock, on the assumption that the fluid‐saturated rock is an isotropic solid. I point out the fallacy of computing [Formula: see text] from these measurements and also urge workers to recognize the losses due to simple fluid viscosity in interpreting their data on extensional waves in rods. By application of published theory, I show that peaks in attenuation of extensional waves are to be expected at frequencies of several hertz to several kilohertz, depending upon rod radius. Computed curves are compared with published measurements on Navajo sandstone saturated with water, ethanol, and n‐decane. In each case, computed peak frequency agrees with published measurements. Shift of the peak frequency with temperature from 4 °C to 25 °C is due to change of viscosity of the saturating fluid (water).

In his recent article ‘Notes Towards a Critique of Buddhist Karmic Theory’ Paul J. Griffiths makes four criticisms of Buddhist karmic theory: it is empirically false, it is incoherent, it is morally repugnant, and it is vacuous. After listing these four criticisms, Griffiths concludes that ‘all these mean that Buddhist karmic theory as expounded in the major theoretical works devoted to it must be false’ (p. 291).

The model proposed describes the radiation of the primary seismic pulse from an explosive source. The model incorporates a viscous Voigt liquid in description of the nonelastic rock deformation that the explosion causes. The problem is solved in the frequency domain, followed by Fourier synthesis to obtain waveforms. Comparisons of the theoretical results with field data in three sedimentary environments of shale, sandstone, and marl indicate good quantitative agreements in shape and duration of transient pulses. Values of angular normal stress obtained at the deformed boundary suggest a dynamic tensile strength of rocks that decreased with duration of the tensile stress transient. The radius of the deformed zone (B) scales with the charge size Q approximately as [Formula: see text] where n is [Formula: see text] or larger.

The mechanical impedance of an electromagnetic speaker is affected by current flowing in the electrical elements, just as the electrical impedance is influenced by the motion of the mechanical system. This paper gives the relation between mechanical impedance and electrical load impedance, making use of the three complex speaker constants evaluated by the motional impedance method presented earlier by R. D. Fay. Measurements are given showing that the mechanical impedance of a WE555 horn driver can be varied over a fairly wide range.

The feasibility of producing tungsten, iron and nickel base alloys with or without a dispersal phase using elemental powders and standard powder metallurgical techniques has been established. Potential areas for further development as well as expected problem areas for such powder metallurgy alloys are also reviewed.

A simple method is described for computing the waveform to be expected from a closely‐spaced pattern of shots or geophones when the individual signal is a pulse. Four strength distributions are compared, and the case of uniform strength along the pattern is discussed in detail. It is concluded that if the individual signal is a short pulse, such as a seismic reflection, then the performance of the pattern is quite comparable for the four source distributions considered.