Showing papers by "University of Virginia published in 1982"
TL;DR: In this article, a class of linear rank statistics is proposed for the k-sample problem with right-censored survival data, which contains as special cases the log rank test (Mantel, 1966; Cox, 1972) and a test essentially equivalent to Peto & Peto's (1972) generalization of the Wilcoxon test.
Abstract: SUMMARY A class of linear rank statistics is proposed for the k-sample problem with rightcensored survival data. The class contains as special cases the log rank test (Mantel, 1966; Cox, 1972) and a test essentially equivalent to Peto & Peto's (1972) generalization of the Wilcoxon test. Martingale theory is used to establish asymptotic normality of test statistics under the null hypotheses considered, and to derive expressions for asymptotic relative efficiencies under contiguous sequences of alternative hypotheses. A class of distributions is presented which corresponds to the class of rank statistics in the sense that for each distribution there is a statistic with some optimal properties for detecting location alternatives from that distribution. Some Monte Carlo results are displayed which present small sample behaviour.
983 citations
TL;DR: In this article, the authors apply several commonly used algorithms and one new algorithm, to a representative problem in galactic gas dynamics, and a careful choice of the algorithm used in a calculation is found to be of the utmost importance in obtaining reliable results.
Abstract: In search of reliable computational methods for cosmic flow problems, we apply several commonly used algorithms and one new algorithm, to a representative problem in galactic gas dynamics. A careful choice of the algorithm used in a calculation is found to be of the utmost importance in obtaining reliable results. Two methods most commonly employed in astronomy (the Beam scheme and FCT methods) prove to be highly unsuitable for our test problem. The penalty in programming effort and computer time per grid point required for the best second-order accurate codes tested is more than offset by the improvement in accuracy obtained and the possibility to reduce the number of points in a grid.
824 citations
TL;DR: The impairment in renal function produced by increased intra-abdominal pressure is a local phenomenon caused by direct renal compression and is not related to cardiac output.
Abstract: The effect of increased intra-abdominal pressure on cardiac output and renal function was investigated using anesthetized dogs into whom inflatable intraperitoneal bags were placed. Hemodynamic and renal function measurements were made at intra-abdominal pressures of 0, 20, and 40 mmHg. Renal blood flo and glomerular filtration rate decreased to les than 25% of normal when the intra-abdominal pressure was elevated to 20 mmHg. At 40 mmHg intra-abdominal pressure, three dogs became anuric, and the renal blood flow and glomerular filtration rate of the remaining dogs was 7% of normal, while cardiac output was reduced to 37% of normal. Expansion of the blood volume using Dextran-40 easily corrected the deficit in cardiac output, but renal blood flow and glomerular filtration rate remained less than 25% of normal. Renal vascular resistance increased 555% when the intra-abdominal pressure was elevated from 0 to 20 mmHg, an increase fifteen-fold that of systemic vascular resistance. This suggests that the impairment in renal function produced by increased intra-abdominal pressure is a local phenomenon caused by direct renal compression and is not related to cardiac output.
527 citations
TL;DR: In this article, a saltwater flume was used to describe the mechanics of current flow around an articial Zostera marina meadow, where current velocity intrusion into the meadow before diminution and maximum reduction (both at the 2 cm height line) proceed by factors of 1·25 and 2·07 cm into a meadow per cm s −1 of current velocity, respectively.
Abstract: A salt-water flume was used to describe the mechanics of current flow around an articial Zostera marina meadow. Shear velocity and roughness height were positively correlated with seagrass surface area, and were positively/negatively correlated with current velocity. Current velocity intrusion into the meadow before diminution and maximum reduction (both at the 2 cm height line) proceed by factors of 1·25 and 2·07 cm into the meadow per cm s −1 of current velocity, respectively. Froude number was correlated with mean bending angle of the canopy as a whole. Maximum bending had occurred with Froude = 1, but most bending had taken place by Froude = 0·4, a velocity of 40–50 cm s −1 in this experiment. The meadow edge is the most dynamic zone of a seagrass meadow in regard to current flow. Bending of the shoot canopy is a mechanism for re-direction of current flow and in-canopy reduction of current velocity. Meadow dimensions may be regulated by scouring processes in different hydraulic regimes. Shoot bending and subsequent in-meadow current velocity reduction are mechanisms that affect self-shading and photosynthetic capabilities as well as providing habitat stability.
449 citations
TL;DR: Moderate head injury results in mortality and substantial morbidity intermediate between those of severe and minor head injury and more attention should be directed to patients with moderate head injury than to those with the most severe injuries, in whom brain damage is probably irreversible and all forms of management have demonstrated little success.
Abstract: We have divided head injury into three categories based on the Glasgow Coma Scale (GCS) (severe, 3-8; moderate, 9-12; and minor, 13-15). In a previous report, we described significant disability after minor head injury. The present report describes 199 patients with moderate head injury, 159 of whom underwent follow-up examinations at 3 months. In contrast to patients with minor head injury, half as many were students (17%) and twice as many were intoxicated (53%). Seventy-five patients were studied with computed tomographic (CT) scanning; 30% of the scans were negative and 31% showed a space-occupying mass. As reported by Gennarelli et al. in patients with severe head injuries, those with moderate head injury and subdural hematoma had a very poor outcome: 65% died or were severely disabled and none made a good recovery as measured by the Glasgow Outcome Scale. At 3 months, 38% of the moderate head injury patients had made a good recovery compared with 75% of the minor head injury patients. Within the good recovery category, however, there was much disability (headache, 93%; memory difficulties, 90%; difficulties with activities of daily living, 87%), and only 7% of the patients were asymptomatic. The Halstead-Reitan Neuropsychological Battery in an unselected subset (n = 32) showed significant deficits on all test measures. Sixty-six per cent of the patients previously employed had not returned to work, compared to 33% of the minor head injury patients. The major predictors of unemployment after minor head injury were premorbid characteristics (age, education, and socio-economic status). In contrast, all predictors in moderate head injury were measures of the severity of injury (length of coma, CT diagnosis, GCS on discharge). We conclude that: (a) moderate head injury, not described previously in the literature, results in mortality and substantial morbidity intermediate between those of severe and minor head injury; (b) unlike minor head injury, the principal predictors of outcome after moderate head injury are measures of the severity of injury; and (c) more attention should be directed to patients with moderate head injury than to those with the most severe injuries, in whom brain damage is probably irreversible and all forms of management have demonstrated little success.
438 citations
TL;DR: In this article, information on nineteen metals in atmospheric deposition potentially toxic to humans and other organisms was evaluated to conclude if metal concentrations are increasing in atmospheric deblurring and if these concentrations threaten human or organism health.
413 citations
TL;DR: The abbreviated burn severity index is a simple and clinically useful score that is derived from multivariate logistic regression that demonstrates predictive power for classifying patients according to their risk.
375 citations
358 citations
TL;DR: A categorization process based on two powerful project summary measures is provided, and it is shown that a rule introduced by this research performs significantly better on most categories of projects.
Abstract: Application of heuristic solution procedures to the practical problem of project scheduling has previously been studied by numerous researchers. However, there is little consensus about their findings, and the practicing manager is currently at a loss as to which scheduling rule to use. Furthermore, since no categorization process was developed, it is assumed that once a rule is selected it must be used throughout the whole project. This research breaks away from this tradition by providing a categorization process based on two powerful project summary measures. The first measure identifies the location of the peak of total resource requirements and the second measure identifies the rate of utilization of each resource type. The performance of the rules are classified according to values of these two measures, and it is shown that a rule introduced by this research performs significantly better on most categories of projects.
300 citations
TL;DR: Two dimensional echocardiography performed soon after admission to the coronary care unit is technically feasible, provides useful information concerning regional and global left ventricular function and offers important predictive information about patients early in acute myocardial infarction.
Abstract: Seventy-five consecutive patients with acute myocardial infarction underwent two dimensional echocardiography 7.9 ±3.1 hours after admission (1) to determine if this procedure can detect regional left ventricular asynergy in an unselected series of patients; (2) to evaluate the relation of asynergy outside the electrocardiographic infarct zone to clinical events and coronary anatomic findings; and (3) to determine whether the procedure can identify patients at high risk for cardiogenic shock, before the onset of hemodynamic deterioration. For purposes of analysis, the left ventricle was divided into 11 segments; individual segments were evaluated for systolic wall motion and thickening, and a wall motion index was calculated as a measure of global left ventricular performance. Technically satisfactory two dimensional echographic studies were obtained in all 75 patients. Of 825 possible segments in the 75 patients, 795 (96 percent) or 10.6 segments per patient were deemed adequate for analysis. Akinesia or dyskinesia was detected in at least one segment in all patients, including 15 (20 percent) who underwent imaging within 4 hours of the onset of symptoms and 19 (25 percent) with nontransmural infarction. Severe wall motion abnormalities outside the infarct zone were observed in 47 percent of patients and correlated with a greater prevalence of death (p = 0.03), cardiogenic shock (p Thus, two dimensional echocardiography performed soon after admission to the coronary care unit is technically feasible, provides useful information concerning regional and global left ventricular function and offers important predictive information about patients early in acute myocardial infarction.
269 citations
TL;DR: The 2DE EF formulae that utilized biplane areas were generally more accurate than single-plane area or diameter onlyformulae, but were obtainable in fewer patients, while biplane formULae for calculating EF yield better correlations, but are available from fewer patients thansingle-plane formuleae.
TL;DR: In this article, the authors developed a relationship between aggregate safety stock inventory levels and component part commonality, and a simulation experiment strongly supported the functional form of this relationship in an uncertain operating environment.
Abstract: The relationship between aggregate safety stock inventory levels and component part commonality is developed. A simulation experiment strongly supports the functional form of this relationship in an uncertain operating environment.
Managers can use these equations to assess the trade-offs between aggregate safety stock levels, service level and the degree of component part standardization. For example, these relationships can be used to predict service, inventory level and cost standards for any change in component part commonality.
TL;DR: It is suggested that the mechanism of facilitation or attenuation of analgesia by the enkephalins is a direct in vivo consequence of this coupling and the analgesic potencies of various opioid ligands can be better correlated to the combination of their simultaneous occupancy of mu and delta receptors.
TL;DR: The universal Newtonian gravitational constant was determined at the National Bureau of Standards with use of the method of Boyes in which the period of a torsion pendulum is altered by the presence of two 10.5-kg tungsten balls.
Abstract: The universal Newtonian gravitational constant is being redetermined at the National Bureau of Standards with use of the method of Boyes in which the period of a torsion pendulum is altered by the presence of two 10.5-kg tungsten balls. The difference in the squares of the frequencies with and without the balls is proportional to $G$. The resulting value of $G$ is (6.6726\ifmmode\pm\else\textpm\fi{}0.0005)\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}11}$ ${\mathrm{m}}^{3}$\ifmmode\cdot\else\textperiodcentered\fi{} ${\mathrm{sec}}^{\ensuremath{-}2}$\ifmmode\cdot\else\textperiodcentered\fi{} ${\mathrm{kg}}^{\ensuremath{-}1}$\ifmmode\cdot\else\textperiodcentered\fi{}
TL;DR: A confluence of several factors has served to highlight the saliency of mentally disordered offenders to mental health and criminal justice agencies in recent years as discussed by the authors, including the demands for levels of predictive accuracy and treatment efficacy that appear to exceed the state of mental health sciences in the present or foreseeable future.
Abstract: Persons believed both to be mentally ill and to have committed criminal behavior"mentally disordered offenders"' are enmeshed in a Byzantine pattern of relationships between mental health and correctional agencies, such that they often receive the worst that both systems have to offer (Kittrie, 1971; Wexler, 1976). As well, they confront forensic psychiatry and psychology with ethical dilemmas that defy easy resolution (Roth, 1980) and with demands for levels of predictive accuracy and treatment efficacy that appear to exceed the state of the mental health sciences in the present or foreseeable future (Steadman, 1980; Monahan, 1981). A confluence of several factors has served to highlight the salience of mentally disordered offenders to mental health and criminal justice agencies in recent years.
TL;DR: Parvalbumin and the sarcoplasmic reticulum (SR) pump were complementary relaxing factors that removed Ca2+ from the cytosol and from the T-sites and may have a high adaptive value in cold-blooded animals.
Abstract: The distribution of Ca2+ and Mg2+ among the 'regulatory' cation binding sites of troponin (T-sites) and the strong, Ca2+-Mg2+ binding sites of troponin and parvalbumins (P-sites) in the sarcoplasm of a muscle was calculated. At rest, 60% of the T-sites were metal free, while 92% of the P-sites were loaded with Mg2+. In response to a Ca2+ pulse, troponin-calcium (T-Ca) complexes were rapidly formed, while the binding of Ca2+ to P-sites was limited by the slow rate of dissociation of the parvalbumin-magnesium (P-Mg) complexes. Muscle activation was not prevented by a high content of parvalbumins. Parvalbumin and the sarcoplasmic reticulum (SR) pump were complementary relaxing factors that removed Ca2+ from the cytosol and from the T-sites. Parvalbumins dominated the first part of relaxation, while the action of the SR was essential to ensure the return to a very low level of free Ca2+ ion and of T-Ca. After relaxation, a large fraction of the Ca2+ pulse was still bound to parvalbumins and returned slowly to the SR during the recovery. When the SR activity was reduced, the presence of parvalbumins preserved a fast rate of relaxation, at least for a few contractions. This may have a high adaptive value in cold-blooded animals.
TL;DR: The authors present a report of 12 patients with anal melanoma (AM) and review 255 cases reported since 1947, finding that the most useful diagnostic criteria were melanin production, junctional change, and a nesting growth pattern.
Abstract: The authors present a report of 12 patients with anal melanoma (AM) and review 255 cases reported since 1947. Combining these patients with those from the literature, the authors analyze several aspects of AM that are controversial or have not been studied in a systematic manner. The mean clinical tumor size was 4.1 cm. Seventy per cent were grossly pigmented, 63 per cent were polypoid, and 44 per cent were prolapsed. Two-thirds of AM were located in the proximal pecten, at or near the level of the anal valves. Microscopically, the most useful diagnostic criteria were melanin production, junctional change, and a nesting growth pattern. In four of the authors’ cases, atypical junctional change extended laterally from the overt invasive neoplasm for distances up to 1 cm. Approximately 60 per cent of patients had metastases at the time of diagnosis. There was no statistical difference in determinate survivals of patients treated for cure by local excision and abdominoperineal resection. Neither tumor size nor configuration affected survival. The choice of therapy was not influenced by tumor size.
TL;DR: Brown et al. as mentioned in this paper derived the quadrupolar spin-lattice (T1) relaxation rates of 2H and 14N in lipid bilayers, as a function of temperature and frequency, and extended the analysis to include relatively slow fluctuations of the local director with respect to the macroscopic bilayer normal.
Abstract: Based on a previous, more approximate treatment [M. F. Brown, J. Magn. Reson. 35, 203 (1979)], expressions are derived for the quadrupolar spin‐lattice (T1) relaxation rates of 2H and 14N in lipid bilayers. Results are presented for the most general, anisotropic rotational diffusion model describing the segmental or molecular reorientation in lipid bilayers, and the analysis is extended to include relatively slow fluctuations of the local director with respect to the macroscopic bilayer normal. Numerically computed values of T1 for the diffusion model suggest that, even for extremes of ordering and motional anisotropy, such a model cannot by itself quantitatively account for the observed 2H T1 values of multilamellar dispersions of 1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine (DPPC), in the liquid crystalline state, as a function of temperature and frequency. The contribution from relatively low frequency motions is modeled in terms either (i) a simple noncollective model in which the slow motions are described in terms of a single effective correlation time, or (ii) a collective model in which the relatively slow reorientation is described by a distribution of correlation times, corresponding to collective fluctuations of the instantaneous director. The experimentally observed dependence of the 2H T1 relaxation rates on the acyl chain segmental order parameter SCD and the resonance frequency ω0 are most consistent with a collective model for slow molecular reorientations in lipid bilayers. The 2H T1 data for the saturated DPPC bilayer, in the liquid crystalline state, can be quantitatively described by a relaxation law of the form T−11 = Aτf+BS2CD ω−1/20 as observed for simpler nematic and smectic liquid crystals. The first (A) term is suggested to correspond to trans–gauche isomerizations of the lipid acyl chains, while the (B) term describes collective bilayer modes which predominantly influence the frequency dependence of the relaxation. In contrast to earlier conclusions [M. F. Brown et al., J. Chem. Phys. 70, 5045 (1979)], the dominant contribution to the 2H T1 relaxation rates of the saturated DPPC bilayer may arise from collective order fluctuations rather than fast local motions. The value of τf∼10−11 s obtained by extrapolating T−11 to infinite frequency or zero ordering is consistent with the correlation times calculated from 2H or 13C T1 data for n‐alkanes of equivalent chain lengths, suggesting that the microviscosity of the bilayer hydrocarbon region is not appreciably different from that of paraffinic liquids.
TL;DR: These studies indicate that experimental rhinovirus colds can be spread by way of contaminated environmental surfaces and suggest that disinfectant treatment of such surfaces may reduce risk of viral transmission by this route.
Abstract: Transfer of experimental rhinovirus infection by an intermediary environmental surface was examined in healthy young adults, in four studies done in 1980--1981, by having recipients handle surfaces previously contaminated by infected donors. Recipients touched their nasal and conjunctival mucosa after touching the surfaces. Five (50%) of 10 recipients developed infection after exposure to virus-contaminated coffee cup handles and nine (56%) of 16 became infected after exposure to contaminated plastic tiles. Spraying of contaminated tiles with a commercially available phenol/alcohol disinfectant reduced (p = 0.003) the rate of recovery of virus from the tiles from 42% (20/47) to 8% (2/26). Similarly, the rate of detection of virus on fingers touching the tiles was reduced (p = 0.001) from 61% (28/46) with unsprayed tiles to 21% (11/53) with sprayed tiles. Fifty-six per cent (9/16) of the recipients exposed on three consecutive days to untreated tiles became infected while 35% (7/20) touching only sprayed tiles became infected with rhinovirus (p = 0.3). These studies indicate that experimental rhinovirus colds can be spread by way of contaminated environmental surfaces and suggest that disinfectant treatment of such surfaces may reduce risk of viral transmission by this route.
TL;DR: A new, precoded, self-report questionnaire was used to collect information on 75 patient members of the Tourette Syndrome Association, indicating that the diagnosis of TS is being made earlier and haloperidol is an effective treatment for many patients.
Abstract: A new, precoded, self-report questionnaire was used to collect information on 75 patient members of the Tourette Syndrome Association. This diverse group of Tourette's syndrome (TS) patients supplied by mail detailed medical, symptom, developmental, family, and personal history information. Analysis of these data supported the usefulness and validity of the questionnaire, and also indicated that the diagnosis of TS is being made earlier; attentional difficulties may be basic to the disorder; haloperidol is an effective treatment for many patients, but alternative treatments are needed because unpleasant side effects of haloperidol often lead to discontinued use, and TS is disabling for many with most patients reporting serious problems in one or more areas of functioning.
TL;DR: Light- and electron-microscopic observations suggest that the small dark bodies in the cell layer are probably condensed nuclei, and that the preferential vulnerability of dentate granule cells following intrahippocampal injection was observed at all doses.
TL;DR: The data indicate that LC 20 phosphorylation is necessary for cross-bridge cycling leading to shortening or stress development but that stress can be maintained by additional mechanisms and suggest that dephosphorylation of an attached cross bridge in the presence of Ca2+ arrests the cycle, forming an attached, noncycling cross bridge.
Abstract: The time course of phosphorylation of the 20,000-dalton myosin light chain (LC 20) was determined during contraction and relaxation in K+- and histamine-stimulated medial strips of swine carotid arteries. Resting LC 20 phosphorylation levels of 0.15 mol P/mol LC 20 rapidly increased to peak values of 0.6-0.7 mol P/mol LC 20 after stimulation and then declined significantly, although stress continued to rise to a stable steady-state maximum. LC 20 dephosphorylation after agonist washout preceded the decline in isometric stress. Over the entire contraction-relaxation cycle, phosphorylation was correlated with shortening velocity and not with developed stress. The maximum shortening velocity with no external load (Vo) was directly proportional to LC 20 phosphorylation (r = 0.986). The data indicate that LC 20 phosphorylation is necessary for cross-bridge cycling leading to shortening or stress development but that stress can be maintained by additional mechanisms. We suggest that dephosphorylation of an attached cross bridge in the presence of Ca2+ arrests the cycle, forming an attached, noncycling cross bridge.
TL;DR: In this paper, thermal spike and Coulomb repulsion models for erosion in this temperature regime were discussed and the dependence of the low temperature erosion yield on electronic stopping power is nonlinear and approximately quadratic for light ions.
TL;DR: A simple theory for predicting the response times of unsaturated and saturated flows on hillslopes, based on kinematic wave equations, is presented in this article, where the sensitivity of the unsaturated zone lag and time of concentration of the saturated zone to hillslope and soil parameters, antecedent moisture and input rates is examined.
Abstract: A simple theory for predicting the response times of unsaturated and saturated flows on hillslopes, based on kinematic wave equations, is presented. The sensitivity of unsaturated zone lag and time of concentration of the saturated zone to hillslope and soil parameters, antecedent moisture and input rates is examined. It is shown that for many combinations of parameters subsurface response times are too long to be considered as stormflow; but that the combinations of high hydraulic conductivities, shallow soils and wet initial conditions that lead to fast responses are quite reasonable when compared with field studies of subsurface stormflows. It is suggested that the kinematic theory provides a basis for a practically useful predictive model.
TL;DR: The results are consistent with the conclusion that the observed sequential transcription of vesicular stomatitis virus mRNAs is due to obligatory entrance of all polymerases at the leader gene, and suggest that the transcriptase and replicase may recognize the same promoter.
TL;DR: A modified oxidase reagent, 1% tetramethyl-p-phenylenediamine in dimethyl sulfoxide, proved superior to the routinely used 1% aqueous tetramerethylp-pphenylensiamine dihydrochloride in detecting weakly oxidase-positive gram-negative bacteria after 24 h of growth on agar media.
Abstract: A modified oxidase reagent, 1% tetramethyl-p-phenylenediamine in dimethyl sulfoxide, proved superior to the routinely used 1% aqueous tetramethyl-p-phenylenediamine dihydrochloride in detecting weakly oxidase-positive gram-negative bacteria after 24 h of growth on agar media (40 of 40 positive versus 22 of 40 positive) The bacterial inoculum was obtained with a cotton-tipped swab instead of a loop or wooden applicator, and the reaction required less than 15 s
TL;DR: When the survival probability of patients treated operatively was compared with that of patientstreated nonoperatively, the operative group demonstrated a significantly higher survival probability.
TL;DR: The effect of complexation on the accumulation of dissolved copper by the American oyster Crassostrea virginica was determined in chemically defined exposure media by varying the concentrations of total copper and model chelator, nitrilotriacetic acid.
Abstract: The effect of complexation on the accumulation of dissolved copper by the American oyster Crassostrea virginica was determined in chemically defined exposure media. The speciation of copper was varied by varying the concentrations of total copper and model chelator, nitrilotriacetic acid (NTA). Accumulation of copper in 14-d experiments was related to the cupric ion activity and not the concentration of chelated copper. Rapid accumulation of copper occurred at cupric ion activities above 10-10 M and there was no measurable accumulation at 10-11 M.
TL;DR: Some 170 references to drought and disease along the south-western coast of Central Africa between 1550 and 1830 suggest that climatic and epidemiological factors motivated the farmers and herders of West-Central Africa in historically significant ways.
Abstract: Some 170 references to drought and disease along the south-western coast of Central Africa between 1550 and 1830 suggest that climatic and epidemiological factors motivated the farmers and herders of West-Central Africa in historically significant ways. Nearly all references come from documentary sources and so bear primarily on conditions in the drier and less fertile areas near Luanda and to the south, where African reactions would have been strongest.While minor shortages of rain occurred too frequently to receive much explicit attention in the documents, longer droughts spread more widely every decade or so and attracted notice. Major periods of dryness, extending for seven years or more and touching all parts of the region, occurred perhaps once each century and produced comments throughout the documentation.Localized minor droughts hardly disrupted the lives of Africans, who had presumably devised agricultural and pastoral strategies to take account of such ordinary climatic variation. Two-or three-year rainfall shortages produced banditry and warfare that often attracted Portuguese military retaliation. Major droughts disrupted polities and societies and hence coincided with major turning points in West-Central African history in the late sixteenth and late eighteenth centuries. In the earlier case, agricultural failures produced the famed ‘Jaga’ or Imbangala warriors, who elevated pillage to a way of life and who joined the Portuguese in establishing the Angolan slave trade. The later, protracted drought from 1784 to 1793 coincided with the historic peak of slave exports from West-Central Africa.
TL;DR: The question as to the place of mind in nature is a reformulation of the question of human beings in nature as mentioned in this paper, which is a question that was first raised by T. H. Huxley's essay on 'Man's Place in Nature'.
Abstract: The question as to the place of Mind in Nature is a reformulation of the question as to the place of human beings in nature. T. H. Huxley's essay on 'Man's Place in Nature' * was an attempt to break down the distinction between human beings and animals by viewing our species in the light of biological evolution. For most people at least, Huxley settled the question of whether the existence of our species required a different sort of explanation than did the existence of other kinds of animals. But this result simply transferred the problem to philosophy. The question now became: granted that what is special about human beings was produced by the same sorts of causes as produced the special faculties of the other animal species, are these human facul ties nonetheless so different that there is a special, philosophical problem about their nature? Granted, in other words, that what we call "mind" came into the world by spatio-temporal mechanisms homogeneous with those which produced the rest of the world's contents, what is it that we call "mind"? Something which is simply a special case of the other physical things which emerged? Or something "irreducible" to the physical? This is a vague question because "irreducible" is a multiply am biguous word. Most discussions of "the mind-body problem" argue for reducibility or irreducibility by tacitly choosing a sense, or senses, of "reducible" favorable to their own side. There are many such senses, stretching along a spectrum between a purely causal sense at one end and a purely definitional sense at the other. Those inclined to reduce mind to matter like to think that Huxley's point that mind emerged from matter is enough to show that there can be no ontolo gical discontinuity. So this side employs a sense of "reducible" in which X's are reducible to Y's if all the causes of X's are Y's. Those inclined to proclaim the irreducibility of mind like to think that since you cannot communicate what tarragon tastes like by telling a story about molecules there obviously is an ontological discontinuity. So