Showing papers by "University of Arizona published in 1984"
01 Jan 1984
3,213 citations
TL;DR: In this article, a model that unifies the age and tectonic significance of the Cordilleran metamorphic core complexes was proposed, which reconciles opposing views of the core complexes and places them in a more comprehensible setting with respect to Mesozoic-Cenozoic thermotectonic history.
Abstract: Cordilleran metamorphic core complexes form a belt of uplifted metamorphic rock that extends from southern Canada to northwestern Mexico just west of, or astride, the foreland thrust belt of the North American Cordillera. During the past several years the age and tectonic significance of the core complexes have been a topic of considerable controversy. Some geologists view the complexes as an uplifted erogenic core zone that formed behind the thrust belts mainly during Mesozoic regional compression. An opposing view is that they are mainly Tertiary in age and of extensional origin. We support a model that unifies these seemingly inconsistent views by suggesting that Mesozoic crustal telescoping resulted in an overthickened plateaulike crustal welt along the Cordilleran hinterland. During Cenozoic time this gravitationally unstable mass spread laterally, resulting in deep-seated crustal extension. The extension was aided by a thermal pulse of Cenozoic magmatism that reduced crustal viscosity and by a lowering of intraplate convergent stress fields due to changing plate kinematics. The chief advantage of the model is that it reconciles opposing views as to the age and tectonic significance of the complexes and places them in a more comprehensible setting amid Mesozoic-Cenozoic Cordilleran thermotectonic history.
666 citations
TL;DR: In this paper, a highly flattened disk has been observed around the fourth-magnitude star Beta Pictoris and it is assumed that the disk is associated with planet formation and that the mass density of the disk falls off with approximately the third power of the radius.
Abstract: A circumstellar disk has been observed optically around the fourth-magnitude star Beta Pictoris. First detected in the infrared by the Infrared Astronomy Satellite last year, the disk is seen to extend to more than 400 astronomical units from the star, or more than twice the distance measured in the infrared by the Infrared Astronomy Satellite. The disk is presented to earth almost edge-on and is composed of solid particles in nearly coplanar orbits. The observed change in surface brightness with distance from the star implies that the mass density of the disk falls off with approximately the third power of the radius. Because the circumstellar material is in the form of a highly flattened disk rather than a spherical shell, it is presumed to be associated with planet formation. It seems likely that the system is relatively young and that planet formation either is occurring now around Beta Pictoris or has recently been completed.
643 citations
TL;DR: The most important single observation from this research is the similarity between our wide range of results and the multitude of seemingly divergent conclusions about free riding from previous experimental results as mentioned in this paper, which shows that free riding is neither absolutely all pervasive nor always nonexistent.
Abstract: The most important single observation from this research is the similarity between our wide range of results and the multitude of seemingly divergent conclusions about free riding from previous experimental results. Even when defined in the restrictive manner of this paper, free riding is neither absolutely all pervasive nor always nonexistent. This ‘intermediate’ result is not the same as a general theory which states that the predictable result of public goods provision processes is always weak free riding. The extremes of strong free riding and near-Lindahl optimal behavior can and do occur.
641 citations
TL;DR: In this paper, the authors studied the effect of pollution on global climate and found that the climate effect is comparable to that of increased carbon dioxide, and acts in the opposite direction, in that increasing absorption also attends increasing pollution.
Abstract: Increased pollution leads to increasing particulate concentrations. Since some particles nucleatedrop formation, clouds will contain, with increasing pollution, more drops per unit volume, andhence will tend to be optically thicker and more reflecting. An opposite effect is also present, inthat increasing absorption also attends increasing pollution. Measurements suggest that theformer (brightening) effect is the dominant one for global climate and that the climatic effect isquite comparable to that of increased carbon dioxide, and acts in the opposite direction. DOI: 10.1111/j.1600-0889.1984.tb00254.x
584 citations
TL;DR: In this article, a thin solid element, called a thin-layer element, was proposed for soil-structure interaction and rock joints, and a special constitutive model was used and various deformation modes such as no slip, slip, debonding and rebonding were incorporated.
Abstract: The idea of using a thin solid element, called a thin-layer element, in soil-structure interaction and rock joints is proposed. A special constitutive model is used and various deformation modes such as no slip, slip, debonding and rebonding are incorporated. The shear stiffness is found from special laboratory tests and the normal stiffness is assumed to be composed of participation of the thin-layer element and the adjoining solid elements. A parametric study shows that the thickness of the thin-layer element can be such that the ratio of thickness to (mean) dimension of the adjacent element is in the range of 0.01 to 0.1. A number of simple and practical problems are solved to illustrate the success of the thin-layer element for soil-structure interaction problems.
563 citations
TL;DR: This chapter highlights how the current understanding of the mechanisms and factors influencing virus adsorption can be used to interpret and control virus behavior in the environment.
Abstract: Publisher Summary This chapter highlights how the current understanding of the mechanisms and factors influencing virus adsorption can be used to interpret and control virus behavior in the environment. An understanding of factors controlling the interaction has already led to new and improved methods for the concentration of viruses from water, and their isolation from the environment. It is evident that not all viruses behave alike toward a solid under identical conditions. Under most natural conditions viruses with a low isoelectric point appear to be more poorly adsorbed to most solid surfaces. This must be taken into consideration when evaluating concentration or treatment systems which involve adsorption. This phenomenon is also important in determining the transport of viruses in the environment. Certain enteric viruses appear to adsorb less readily to soils and aquatic sediments than others. Thus their potential transport to groundwater may be greater and they may be less likely to settle in surface waters. To take into consideration these differences in virus behavior, it is perhaps best to use viruses with widely varying isoelectric points or marked differences in hydrophobicity to evaluate the extremes in virus interaction with a given surface which could occur.
506 citations
TL;DR: Extended sources of far-infrared emission superposed on the zodiacal and galactic backgrounds are found at high galactic latitudes and near the ecliptic plane as discussed by the authors.
Abstract: Extended sources of far-infrared emission superposed on the zodiacal and galactic backgrounds are found at high galactic latitudes and near the ecliptic plane. Clouds of interstellar dust at color temperatures as high as 35 K account for much of this complex structure, but the relationship to H I column density is not simple. Other features of the extended emission show the existence of warm structures within the solar system. Three bands of dust clouds at temperatures of 150-200 K appear within 10 deg on both sides of the ecliptic plane. Their ecliptic latitudes and derived distances suggest that they are associated with the main asteroid belt. A third component of the 100-micron cirrus, poorly correlated with H I, may represent cold material in the outer solar system or a new component of the interstellar medium.
448 citations
TL;DR: The second edition of Dainty's widely read book on laser and astronomical speckle as discussed by the authors is a beautiful soft-bound book identical to the first edition (sans typographical errors), except for a rewritten Chapter 7 on "Stellar Speckle Interferometry" and a new Chapter 8 on "Recent Developments" in the overall field of speckles.
Abstract: This is the second edition of a widely read book on laser and astronomical speckle. I have, through the years, extensively used the material in the first edition for teaching purposes and for “meaty” homework problems. The book is very readable, with good introductory material for helping the uninitiated “over the hurdles,” and yet, with a development in each subject to the state of the art in depth (as of 1975). The second edition is a handsome soft-bound book identical to the first edition (sans typographical errors), except for a rewritten Chapter 7 on “Stellar Speckle Interferometry” and a new Chapter 8 on “Recent Developments” in the overall field of speckle. Both are by J. C. Dainty. The other chapters are 1) “Introduction” by J . C. Dainty; 2) “Statistical Properties of Laser Speckle Patterns” by J. W .
439 citations
432 citations
TL;DR: Letter correspondence indicates that 1,25(OH)2D3- induced differentiation of HL-60 cells to monocytes/macrophages is occurring via receptor-mediated events.
Abstract: The human-derived promyelocytic leukemia cell line, HL-60, is known to differentiate into mature myeloid cells in the presence of 1,25-dihydroxyvitamin D3 (1,25[OH]2D3) We investigated differentiation by monitoring 1,25(OH)2D3-exposed HL-60 cells for phagocytic activity, ability to reduce nitroblue tetrazolium, binding of the chemotaxin N-formyl-methionyl-leucyl-[3H]phenylalanine, development of nonspecific acid esterase activity, and morphological maturation of Wright-Giemsa-stained cells 1,25(OH)2D3 concentrations as low as 10(-10) M caused significant development of phagocytosis, nitroblue tetrazolium reduction, and the emergence of differentiated myeloid cells that had morphological characteristics of both metamyelocytes and monocytes These cells were conclusively identified as monocytes/macrophages based upon their adherence to the plastic flasks and their content of the macrophage-characteristic nonspecific acid esterase enzyme The estimated ED50 for 1,25(OH)2D3-induced differentiation based upon nitroblue tetrazolium reduction and N-formyl-methionyl-leucyl-[3H]phenylalanine binding was 57 X 10(-9) M HL-60 cells exhibited a complex growth response with various levels of 1,25(OH)2D3: less than or equal to 10(-10) M had no detectable effect, 10(-9) M stimulated growth, and greater than or equal to 10(-8) M sharply inhibited proliferation We also detected and quantitated the specific receptor for 1,25(OH)2D3 in HL-60 and HL-60 Blast, a sub-clone resistant to the growth and differentiation effects of 1,25(OH)2D3 The receptor in both lines was characterized as a DNA-binding protein that migrated at 33S on high-salt sucrose gradients Unequivocal identification was provided by selective dissociation of the 1,25(OH)2D3-receptor complex with the mercurial reagent, p-chloromercuribenzenesulfonic acid, and by a shift in its sedimentation position upon complexing with anti-receptor monoclonal antibody On the basis of labeling of whole cells with 1,25(OH)2[3H]D3 in culture, we found that HL-60 contains approximately 4,000 1,25(OH)2D3 receptor molecules per cell, while the nonresponsive HL-60 Blast is endowed with approximately 8% of that number The concentration of 1,25(OH)2D3 (5 X 10(-9) M) in complete culture medium, which facilitates the saturation of receptors in HL-60 cells, is virtually identical to the ED50 for the sterol's induction of differentiation This correspondence, plus the resistance of the relatively receptor-poor HL-60 Blast, indicates that 1,25(OH)2D3-induced differentiation of HL-60 cells to monocytes/macrophages is occurring via receptor-mediated events
Journal Article•
TL;DR: The opioid receptors involved in the mediation of thermal analgesia and inhibition of gastrointestinal transit at the spinal and supraspinal levels were studied in unanesthetized mice and receptor-selective compounds found to produce analgesia after i.c.v. administration.
Abstract: The opioid receptors involved in the mediation of thermal analgesia (55 degrees C hot-plate) and inhibition of gastrointestinal transit at the spinal and supraspinal levels were studied in unanesthetized mice. Five receptor-selective compounds were evaluated for effectiveness in eliciting analgesia and inhibiting transit after both i.c.v. and intrathecal administration; these included the proposed mu agonist, [D-Ala2, N-methyl-Phe4, Gly5-ol]enkephalin (DAGO), the proposed delta agonists, [D-Pen2, L-Pen5]enkephalin (DPLPE), [D-Pen2, D-Pen5]enkephalin (DPDPE) (conformationally constrained delta selective enkephalin analogs) and [D-Thr2, Thr6, Leu5]enkephalin (DTTLE), and the proposed kappa agonist, trans-3,4-dichloro-N-methyl-N-[2-(1-pyrolidinyl)-cyclohexyl]- benzeneacetamide methanesulfonate (U-50,488H), as well as the nonselective mu-acting agonist, morphine. All compounds were found to produce analgesia after i.c.v. administration; the rank order of potency by the i.c.v. route was DAGO greater than DTTLE greater than morphine greater than DPLPE greater than DPDPE greater than U-50,488H. The analgesic effectiveness of most of these agonists given i.c.v. was evident for up to 40 min, with only DTTLE and U-50,488H having briefer time courses. Similarly, all the compounds produced analgesic responses after intrathecal administration, with the rank order of potency by this route being DTTLE greater than morphine greater than DAGO greater than DPLPE greater than DPDPE greater than U-50,488H, and all compounds (except U-50,488H) had durations of action of up to 20 to 40 min. These agonists also inhibited gastrointestinal transit after intrathecal administration, with a rank order of potency of DAGO greater than DTTLE greater than DPLPE greater than morphine greater than DPDPE greater than U-50,488H.(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: In this article, the authors found that the cataclysmic proto-historic eruption of Santorini (Thera), in the Aegean, is tentatively dated to 1628-26 BC from frost-ring evidence.
Abstract: New data about climatically-effective volcanic eruptions during the past several thousand years may be contained in frost-damage zones in the annual rings of trees. There is good agreement in the timing of frost events and recent eruptions, and the damage can be plausibly linked to climatic effects of stratospheric aerosol veils on hemispheric and global scales. The cataclysmic proto-historic eruption of Santorini (Thera), in the Aegean, is tentatively dated to 1628–26 BC from frost-ring evidence.
TL;DR: In this article, a technique that combines ideas of phase shifting interferometry (PSI) and two-wavelength interference (TWLI) to extend the phase measurement range of conventional singlewavelength PSI is described.
Abstract: This paper describes a technique that combines ideas of phase shifting interferometry (PSI) and two-wavelength interferometry (TWLI) to extend the phase measurement range of conventional single-wavelength PSI. To verify theoretical predictions, experiments have been performed using a solid-state linear detector array to measure 1-D surface heights. Problems associated with TWLPSI and the experimental setup are discussed. To test the capability of the TWLPSI, a very fine fringe pattern was used to illuminate a 1024 element detector array. Without temporal averaging, the repeatability of measuring a surface having a sag of ~100 μm is better than 25-A (0.0025%) rms.
TL;DR: In this article, the authors manipulated five nonverbal cues (eye contact, proximity, body lean, smiling, and touch) to determine what meanings they convey along four relational message dimensions.
Abstract: Based on the assumptions that relational messages are multidimensional and that they are frequently communicated by nonverbal cues, this experiment manipulated five nonverbal cues -eye contact, proximity, body lean, smiling, and touch - to determine what meanings they convey along four relational message dimensions. Subjects (N= 150) observed 2 out of 40 videotaped conversational segments in which a male-female dyad presented various combinations of the nonverbal cues. High eye contact, close proximity, forward body lean, and smiling all conveyed greater intimacy, attraction, and trust. Low eye contact, a distal position, backward body lean, and the absence of smiling and touch communicated greater detachment. High eye contact, close proximity, and smiling also communicated less emotional arousal and greater composure, while high eye contact and close proximity alone conveyed greater dominance and control. Effects of combinations of cues and sex-differences are also reported.
TL;DR: In this article, a model for the ejection of material from an impact crater which links ejection velocity, fragment size, and shock pressure through a simplified stress-wave propagation and reflection scheme is presented.
TL;DR: In this paper, the authors considered the critical exponent γ associated with the expected cluster sizex and the structure of then-site connection probabilities τ =τn(x 1,..., xn) and showed that quite generally γ⩾ 1.
Abstract: Various inequalities are derived and used for the study of the critical behavior in independent percolation models. In particular, we consider the critical exponent γ associated with the expected cluster sizex and the structure of then-site connection probabilities τ=τn(x1,..., xn). It is shown that quite generally γ⩾ 1. The upper critical dimension, above which γ attains the Bethe lattice value 1, is characterized both in terms of the geometry of incipient clusters and a diagramatic convergence condition. For homogeneousd-dimensional lattices with τ(x, y)=O(¦x -y¦−(d−2+η), atp=p
c, our criterion shows that γ=1 if η> (6-d)/3. The connectivity functions τn are generally bounded by tree diagrams which involve the two-point function. We conjecture that above the critical dimension the asymptotic behavior of τn, in the critical regime, is actually given by such tree diagrams modified by a nonsingular vertex factor. Other results deal with the exponential decay of the cluster-size distribution and the function τ2
(x, y).
TL;DR: Somatic cell hybrids are used to show that N-myc is normally localized on the distal short arm of chromosome 2, and in situ hybridization localizes amplified N- myc in neuroblastoma cells to homogeneously staining regions (HSRs) on different chromosomes.
Abstract: Cellular oncogenes comprise a class of genes whose aberrant expression or function may be involved in the development of tumours1. Indeed, several naturally occurring animal and human tumours are associated with consistent alterations in the structure or genomic position of particular cellular oncogenes2–4. Recently, we isolated a DNA segment having limited similarity to c-myc (termed N-myc) from a human neuroblastoma cell line5. Although N-myc was present as a single copy in normal cells, it was selectively amplified up to 140-fold in tumour cells from human neuroblastomas5. Now, we have used somatic cell hybrids to show that N-myc is normally localized on the distal short arm of chromosome 2, and in situ hybridization to localize N-myc to chromosome 2p23–24. Further, in situ hybridization localizes amplified N-myc in neuroblastoma cells to homogeneously staining regions (HSRs) on different chromosomes. Thus, our results suggest that amplification and translocation of N-myc may be interrelated processes associated with human neuroblastoma, and demonstrate that lhe site of N-myc amplification is quite variable and bears no apparent relationship to either the normal single-copy locus or recognized sites of non-random chromosome alteration in human neuroblastoma.
TL;DR: Testing of the model with hospitalized medical patients indicated support for the relationship of uncertainty to stress, and perceived uncertainty had the predicted mediating role between seriousness of illness and stress.
Abstract: A structural model was proposed to explain the stress resulting from hospitalization for a medical problem. Perceived uncertainty about symptoms, treatment, and outcome was examined as a major predictor of stress. Other variables proposed in the model included seriousness of illness, age, education, and recency of rehospitalization. Testing of the model with hospitalized medical patients indicated support for the relationship of uncertainty to stress. Uncertainty also had the predicted mediating role between seriousness of illness and stress. The only other variable supporting the proposed model was age which related inversely to stress. Much of the unexplained variance in the model is attributed to the heterogeneity of diagnoses in the sample. Suggestions for future testing of the model are presented.
TL;DR: The greatly increased tree growth rates observed since the mid-l9th century exceed those expected from climatic trends but are consistent in magnitude with global trends in carbon dioxide, especially in recent decades.
Abstract: A response of plant growth to increased atmospheric carbon dioxide, which has been anticipated from laboratory data, may now have been detected in the annual rings of subalpine conifers growing in the western United States. Experimental evidence shows that carbon dioxide can be an important limiting factor in the growth of plants in this high-altitude environment. The greatly increased tree growth rates observed since the mid-l9th century exceed those expected from climatic trends but are consistent in magnitude with global trends in carbon dioxide, especially in recent decades. If correctly interpreted, these findings have important implications for climate studies involving tree ring observations and for models of the global carbon dioxide budget.
TL;DR: In this article, the frequency difference between prograde and retrograde sectoral solar oscillations was analyzed to determine the rotation rate of the solar interior, assuming no latitudinal dependence, and the resulting solar gravitational quadrupole moment is J2 = (1.7 + or - 0.4) x 10 to the -7th and provides a negligible contribution to current planetary tests of general relativity.
Abstract: The frequency difference between prograde and retrograde sectoral solar oscillations is analyzed to determine the rotation rate of the solar interior, assuming no latitudinal dependence. Much of the solar interior rotates slightly less rapidly than the surface, while the innermost part apparently rotates more rapidly. The resulting solar gravitational quadrupole moment is J2 = (1.7 + or - 0.4) x 10 to the -7th and provides a negligible contribution to current planetary tests of Einstein's theory of general relativity.
TL;DR: The seven participating laboratories received films of two different thicknesses of Sc2O3 and Rh, and the various methods used for determination of the optical constants of these coating materials were described.
Abstract: The seven participating laboratories received films of two different thicknesses of Sc2O3 and Rh. All samples of each material were prepared in a single deposition run. Brief descriptions are given of the various methods used for determination of the optical constants of these coating materials. The measurement data are presented, and the results are compared. The mean of the variances of the Sc2O3 refractive-index determinations in the 0.40–0.75-nm spectral region was 0.03. The corresponding variances for the refractive index and absorption coefficient of Rh were 0.35 and 0.26, respectively.
TL;DR: In this article, the historical fire frequency in a stand of southwestern ponderosa pine has been evaluated in a master fire chronology developed for a prescribed burning study area in Arizona, and 12 specimens used to assemble this chronology were used to date the fire scars accurately, locate missing and locally absent rings, and identify special problems relating to analysis and dating of this unusual specimen.
Abstract: Historical fire frequency in a stand of southwestern ponderosa pine has been doc- umented in a master fire chronology developed for a prescribed burning study area in Arizona. One of the 12 specimens used to assemble this chronology was a small, suppressed tree that contained 42 fire scars. Standard crossdating techniques were used to date the fire scars accurately, locate missing and locally absent rings, and identify special problems relating to analysis and dating of this unusual specimen. Mean fire interval for the study area was about 2 years; mean fire interval for the individual specimen was 4 years for the 178-year period, 1722-1900. FOREST SCI. 30:238-247.
TL;DR: Sixty patients with diabetes mellitus who survived the coronary care unit phase of acute myocardial infarction were followed an average of 19 months and the prognosis of diabetic patients was compared with that of 719 nondiabetic patients.
Abstract: Sixty patients with diabetes mellitus who survived the coronary care unit phase of acute myocardial infarction (AMI) were followed an average of 19 months and the prognosis of diabetic patients was compared with that of 719 nondiabetic patients. The mortality rate was 25% in diabetic patients and 8% in nondiabetic patients. These patients had been entered in a Multicenter Postinfarction Program, where analysis of the total data base showed 4 significant prognostic factors: cardiac symptoms before AMI, pulmonary rales when the patient was in the coronary care unit, more than 10 ventricular premature complexes per hour recorded on Holter monitor just before discharge, and a radionuclide ejection fraction of less than 40%. Of these 4 factors, only cardiac symptoms before AMI was significantly more common in diabetic patients (57% in diabetic vs 36% in nondiabetic patients). When each of these 4 factors was stratified for severity, the mortality rate was always higher in diabetic patients. The data were examined to determine other factors in diabetic patients who died. Pulmonary rales was significantly more common in diabetic patients who died (6% in survivors vs 42% in patients who died). In a multivariate analysis of both diabetic and nondiabetic patients, 5 factors were significant determinants of prognosis. They are, in order of entry into the model, rales (p
TL;DR: In this article, a meta-analysis of the foot-in-the-door (FITD) and door-in the face (DITF) literatures showed both effects to be small (r =.17,.15 respectively).
Abstract: Meta-analysis of the foot-in-the-door (FITD) and door-in-the-face (DITF) literatures showed both effects to be small (r = .17, .15 respectively), even under optimal conditions. Both require aprosocial topic in order to work. The amount of time between the first and second requests plays a different role in the operation of each of the two strategies. DITF was effective only when the delay between requests was brief. Effectiveness of FITD was unrelated to delay, but did depend on whether or not an incentive was provided with the first request. The positive relationship between effort and FITD predicted by self-perception theory was not found. Self-perception theory and reciprocal concessions theory, the theoretical perspectives usually applied to FITD and DITF respectively are examined in light of the findings and it is concluded that both are flawed seriously. Directions for future research are suggested.
TL;DR: Using methyl chloride gas in a ratio mass spectrometer, this article reported significant isotope variation in natural chlorides, and increased the precision of measurement to ± 0.24%.
Abstract: Previously known natural variations in the stable isotope ratio of chlorine, 37Cl/35Cl, have been within the experimental error of ±1.0‰. [All our measurements are reported in terms of δ37 in units of ‰; δ37Cl = |(Rx/Rs)−1|×1,000, where R = 37Cl/35Cl.] Using methyl chloride gas in a ratio mass spectrometer, we have increased the precision of measurement to ±0.24%, and report here significant isotope variation in natural chlorides. In general, salt deposits and saline hydrothermal springs tend to be enriched in 37Cl with respect to seawater. Groundwater shows both enrichment and depletion with respect to seawater. Saline groundwater becomes more enriched in 37Cl with increasing depth.
TL;DR: Data to indicate the possible involvement of the raffinose family of oligosaccharides in flatulence production are given and molecular and physicochemical properties of legume starches are discussed.
TL;DR: This paper demonstrates that a meaningful system response can be calculated by averaging over an ensemble of point-source system inputs to yield an MTF which accounts for the combined effects of image formation, sampling, and image reconstruction.
Abstract: Sampling generally causes the response of a digital imaging system to be locally shift-variant and not directly amenable to Modulation Transfer Function (MTF) analysis. However, this paper demonstrates that a meaningful system response can be calculated by averaging over an ensemble of point-source system inputs to yield an MTF which accounts for the combined effects of image formation, sampling, and image reconstruction. As an illustration, the MTF of the Landsat MSS system is analyzed to reveal an average effective instantaneous field of view which is significantly larger than the commonly accepted value, particularly in the along-track direction where undersampling contributes markedly to an MTF reduction and resultant increase in image blur.
TL;DR: In all nonsurvivors, it was impossible to maintain diastolic pressure above 30 mm Hg even with large doses of epinephrine and saline, which appears important for survival.
Abstract: A study was done to determine if 12 dogs could be resuscitated from 30 min of ventricular fibrillation if aortic diastolic blood pressure was maintained above 30 mm Hg by administration of epinephrine and, in 6 cases, saline solution during cardiopulmonary resuscitation (CPR). Of the 12 dogs seven were resuscitated successfully. The survivors received 3.4 +/- 1.7 mg of epinephrine, whereas the nonsurvivors received 11.1 +/- 2.1 mg of epinephrine. The aortic diastolic blood pressure was significantly higher (p less than .05) in the survivors at 12, 18, 24, and 30 min of ventricular fibrillation. In all nonsurvivors, it was impossible to maintain diastolic pressure above 30 mm Hg even with large doses of epinephrine and saline. Maintenance of an adequate diastolic blood pressure during CPR appears important for survival.
TL;DR: The model abstraction structure is introduced as a vehicle for model representation which supports both heuristic and deterministic inferencing as well as the conceptual/external schema notion familiar to database management.
Abstract: This paper examines the concept of a model management system, what its functions are, and how they are to be achieved in a decision support context The central issue is model representation which involves knowledge representation and knowledge management within a database environment The model abstraction structure is introduced as a vehicle for model representation which supports both heuristic and deterministic inferencing as well as the conceptual/external schema notion familiar to database management The model abstraction is seen as a special instance of the frame construct in artificial intelligence Model management systems are characterized as frame-systems and a database implementation of this approach is described