Showing papers by "Indiana University published in 1970"

Toward a Definition of “Virtual Worlds”

Abstract: This is a brief essay, we call "think-pieces", designed to stimulate a discussion on a particular topic. The topic for this series of essays is "defining virtual worlds".

A Thermophilic, Acidophilic Mycoplasma Isolated from a Coal Refuse Pile

Abstract: A thermophilic, acidophilic procaryote lacking a cell wall has been isolated from a coal refuse pile which had undergone self-heating. Electron micrographs, chemical assays for hexosamine, and the inability of vancomycin to inhibit growth confirm the lack of a cell wall. The apparent ability of the organism to reproduce by budding and the low guanine plus cytosine content of its DNA indicate a relation to the mycoplasmas. The temperature optimum of the organism is 59°C, and growth occurs over a range of 45° to 62°C. No growth occurs at 37°C or at 65°C. The optimum pH for growth is between 1 and 2, and growth occurs between pH 0.96 and 3.5 but does not occur at pH 0.35 and only poorly at pH 4.0. We propose to call this organism Thermoplasma acidophila. The existence of this organism extends considerably the range of habitats in which mycoplasma may occur.

Chapter 12 Methods in Paramecium Research

Abstract: Publisher Summary This chapter discusses methods in Paramecium research. Paramecium and other eukaryotic unicells occupy a strategically important level of biological structure and function between the levels of prokaryotic and multicellular organisms. Paramecium possesses many attractive research features, some of them are (1) it is readily obtainable from nature, from commercial sources, and from investigators. (2) It is readily cultivated in isolation by methods varying from the simplest and crudest to fully defined axenic culture, and several others. Methods used in research on the general biology and genetics of P. aurelia were set forth by Sonneborn. This chapter updates the summary and extends it to all species of Paramecium. Paramecium caudatum, P. multimicronucleatum, P. aurelia, and P. bursaria occur commonly, and P. trichium and P. polycaryum less commonly, in still and moving fresh-water. For ecological and other studies that require sampling of natural sources Hairston and Kellerman exploited the long-known fact that paramecia swim toward the cathode in a weak electric current. The results of genetic work on higher organisms led to the concept of the gene that made possible the successful attack on the molecular genetics of bacteria and viruses.

The Identity of Women's Clothing Fashion Opinion Leaders:

Abstract: This article analyses the characteristics of women's clothing fashion opinion leaders. The data suggest that substantial differences exist between fashion opinion leaders and non-leaders on a wide ...

Identification of ultrasound echoes from the left ventricle by use of intracardiac injections of indocyanine green.

Abstract: This study was designed to identify the ultrasound echoes originating from the left ventricle. Injections of indocyanine green and saline were made directly in the left ventricular cavity via a cardiac catheter in patients undergoing routine diagnostic cardiac catheterization. The injections produced a cloud of echoes that filled the left ventricular cavity and outlined the left side of the interventricular septum and the endocardial surface of the posterior left ventricular wall. The results of this study verified the origin of echoes that are vital to the ultrasound technics for the detection of pericardial effusion, left ventricular wall size, left ventricular cavity size, and left ventricular stroke volume. This study also provided ways of distinguishing between the true left ventricular wall echoes and intracavitary echoes that often cause confusion.

From Columbus to Castro: The History of the Caribbean 1492-1969

Abstract: This landmark work, by the late Prime Minister of Trinidad, illuminates a profoundly important but neglected and misrepresented area of the world. 50 photos, maps.

The metabolism in vivo of glycine and serine in eight areas of the rat central nervous system.

Abstract: — Results of studies designed to estimate the rates at which glycine is derived from various possible sources in discrete areas of the rat CNS are reported. These results suggest that glycine is derived predominantly by de novo synthesis, presumably via the established pathways leading from glucose through serine to glycine. The content of glycine ranged from a low of approximately 0-6 μmol/g in the cerebellum and telencephalon to a high of 5·5 μmol/g in the spinal cord grey matter; however, based on its estimated rate of synthesis from serine, there appeared to be no correlation between the content of glycine and its rate of synthesis in the various areas studied. The flux of glycine from blood into the CNS was slower (0·03-0·15 μmol/g/h depending on the CNS structure) than that of serine (0·15-0·23 μmol/g/h) and both amino acids entered various CNS areas at rates unrelated to their respective tissue contents. These data have been discussed with regard to the putative transmitter function of glycine in the spinal cord and brainstem.

Isolation of a Nonpigmented, Thermophilic Bacterium Similar to Thermus aquaticus

Abstract: A thermophilic (70 C), gram-negative bacterium has been isolated that resembles Thermus aquaticus but lacks the type-characteristic yellow carotenoid.

Gene action in development.

Abstract: This paper deals with processes occurring in the assembly of genic products into cell organelles and structures, especially with processes determining the initiation, location, orientation and number of cortical structures in the ciliated protozoan, Paramecium aurelia . The examples analysed experimentally are: ciliary basal bodies and their associated structures, the repeating unit territory of cortical structure, the pattern of path directions of the rows of basal bodies and unit territories, the distribution in the cortex of two different kinds of unit territories, and the ingestatory apparatus (vestibule and gullet). Among the processes that appear to occur are homonucleation, heteronucleation, and allosteric transitions, as found by others in the in vitro assembly of bacterial flagella, bacterial viruses, and the parts of ciliary microtubules and their appendages. In Paramecium , new basal bodies can arise only in one position and orientation, close and at right angles to an existing basal body at a specified spot. Unit territories reproduce by forming additional parts and subdividing. The information for the positioning and orientation of the developing parts of the unit territory is located within the unit itself and, when experimentally altered, reproduces in the altered orientation which cannot be corrected by genic action. This hereditary aspect of development is determined by an unbroken chain of self-reproducing arrangements of cortical parts. Search for DNA in the cortex gave negative results. Analysis of the hereditary determination of initiation, location, and orientation of the gullet gave results similar to those on the basal body and unit territory. Analysis of the hereditary determination of the path of the rows of unit territories and basal bodies and of the distribution of the two kinds of unit territories showed developmental and genetic control by spatial relations to the vestibule-gullet. Thus, for all corticaltra its examined, development is hereditarily determined by existing and self-reproducing cortical arrangements: the genes (or DNA) doubtless control synthesis of the molecular building blocks, but not their site of assembly or the position, orientation and number of assemblies. The flatworm Stenostomum also shows hereditary developmental control by self-perpetuating structural arrangements, two variations from normal (two kinds of doublet worms) reproducing true to type during asexual reproduction. Whether similar processes occur in the inheritance of the developmentally decisive organization of the amphibian egg is still an open question The processes described in this paper constitute but one of many options available for hereditary control of development.

Fine structure of degeneration and regeneration in denervated rabbit vallate taste buds.

Abstract: Taste buds of rabbit circumvallate papillae were studied with the electron microscope at intervals from six hours to 11 weeks after section of the glossopharyngeal nerve distal to the petrosal ganglion. Nerve endings were first affected, showing degeneration as early as 12 hours and disappearing by 48 hours. Rapid loss of cells and of all buds by ten days followed. Numerous inclusion bodies within type I and type II cells were interpreted as autophagic activity in type II cells and both phagocytic and autophagic activity in type I cells. Type III cells were lost primarily by pyknosis, and phagocytized by type I cells. No clear evidence of dedifferentiation, or extrusion of dead cells, was observed. Regenerated nerves appeared beneath the epithelium at 21 days but new buds first appeared at 25 days, after nerves had penetrated the basement membrane. Intimate contact of nerves with epithelial cells appears to be a precondition for taste bud renewal. Early appearance of cells resembling basal cells (type IV) followed by relatively simultaneous appearance of type I, II and III suggest independent origins for these three types. The data support a humoral hypothesis of trophic action but do not rule out a role for impulse transmission.

Echocardiographic diagnosis of pericardial effusion.

Abstract: Echocardiography, because of its ability to detect intracardiac structures in a noninvasive manner, has been increasing in importance as a cardiologic diagnostic tool. The ultrasonic diagnosis of pericardial effusion has stimulated much of the interest in echocardiography in this country. With this technique pericardial fluid is recorded as a relatively echo-free space between the posterior left ventricular epicardium and the posterior pericardium. Anterior fluid is seen as a similar echo-free space between the anterior right ventricular wall and the anterior chest wall. Although the examination is fairly simple and frequently can be performed in a few minutes, the examiner must be aware of technical details, especially with respect to direction of the transducer and control settings on the echograph. In addition, it may be difficult to obtain satisfactory echocardiographic recordings in some patients, such as those with marked pulmonary emphysema. However, these few limitations are overshadowed by the many advantages of a harmless, sensitive, bedside examination for pericardial fluid. Thus, in many institutions echocardiography is becoming the examination of choice for the detection or exclusion of pericardial effusion.

Algebraic completeness results for r-mingle and its extensions

Abstract: Schiller Joe Scroggs in [9] established remarkable facts concerning “normal” extensions of the modal sentential calculus S5, the most notable of these facts being that all such proper extensions have finite characteristic matrices. The major import of the present paper is that like facts hold for the relevant sentential calculus R-Mingle (RM). Robert K. Meyer in [6] has obtained an important completeness result for RM, which will play a central role in our results. However, in §2 we shall obtain a new proof of Meyer's result as a by-product of the algebraic logic that we develop in §1. Also in §2 we shall obtain the promised results for extensions of RM. In §3 we shall provide a strong completeness theorem for RM by generalizing the semantics of Meyer.

Comparative effects of smoking marihuana or placebo on human motor and mental performance.

Abstract: Motor and mental performance was tested after smoking a placebo cigarette and after smoking a marihuana cigarette calibrated to deliver 5 mg. of delta‐9‐tetrahydrocannabinol. A significant decrement in all motor performance tests and in five of nine mental performance tests was observed after the marihuana cigarette. We were not able to detect any cannabinols in the blood or urine of subjects who smoked the marihuana.

Microtus Population Biology: Behavioral Changes Associated with the Population Cycle in M. Ochrogaster and M. Pennsylvanicus

Abstract: If aggressive behavior regulates population size in small rodents (as claimed by Chitty 1967), periodic fluctuations must be associated with behavioral changes. In an attempt to test this hypothesis, exploratory activity and aggressive behavior were measured in 645 male Microtus ochrogaster and 570 M. pennsylvanicus of 7 populations in southern Indiana from August 1965 to September 1967. Exploratory activity was measured in an open—field test under daylight conditions, and aggressive behavior was measured by fighting voles in pairs in a neutral fighting arena. Exploratory activity could not be related to the individual attributes of home range size or duration of life in males of either Microtus species. On the population level, mean exploratory activity could predict the mean rate of population growth in M. ochrogaster populations, but not in M. pennsylvanicus populations. Aggressive behavior changed significantly over the population cycle in both species, and males from peak populations were most aggressive. Multiple discriminant analysis was used to characterize the behavior patterns of males from increasing, peak, and declining populations. These discriminant scores predicted the mean rate of population growth in M. pennsylvanicus populations but not in M. ochrogaster populations. Aggressive behavior types characteristic of increase, peak, and decline phases showed differential survival rates, but no association was found with body weight or transferrin genotype in either species. Home range size was related to aggressive behavior type in M. ochrogaster but not in M. pennsylvanicus. These data on two species of Microtus do not refute the hypothesis that aggressive behavior may act to regulate population size. However, there is no information on what causes these behavioral changes, and the next step is to see if these changes occur in other populations of these two species and to determine whether they are genotypic or phenotypic.

Ophryocystis elektroscirrha sp. n., a Neogregarine Pathogen of the Monarch Butterfly Danaus plexippus (L.) and the Florida Queen Butterfly D. gilippus berenice Cramer1

Abstract: SYNOPSIS. Naturally occurring populations of the monarch butterfly, Danaus plexippus (L.) and the Florida queen butterfly D. gilippus berenice Cramer were found infected with Ophryocystis elektroscirrha sp. n. This neogregarine pathogen infects the hypodermal tissue, remains in micronclear schizogony until after pupation of the host, and then rapidly completes morphogenesis in the tissue that becomes the scales of the adult butterfly. The adult thus carries the spores externally; no internal infection was detected. The pathogen is unique in the genus Ophryocystis because: other species have all been reported from the Malphigian tubules of Coleoptera; no pseudopodial attachments of schizonts to host tissue were seen; the merozoites were motile; the cystic membrane surrounding the zygote was tenuous, and the sporont developed with no apparent membrane other than the spore wall: and the spore wall appeared amber in transmitted light when morphogenesis was completed.

Three variable-gene pools common to IgM, IgG and IgA immunoglobulins.

Abstract: Comparison of the NH2-terminal region of several α, γ and μ chains indicates that four variable-sequence subgroups are common to heavy chains. The existence of three independent variable-gene pools common to the three major immunoglobulin classes is confirmed.

Forgetting: Trace Erosion or Retrieval Failure?

Abstract: A series of lists of random words was presented. Following each list, the subject attempted to recall the words of the list prior to the list just presented. Recall probability for a given word depended on the length of the list in which it was embedded, not on the length of the list intervening between presentation and test. These results indicate that forgetting is a failure in the memory search during retrieval rather than a degradation of the memory trace occurring between presentation and test.

A Network Flow Solution to a Rectilinear Distance Facility Location Problem

Abstract: The problem of locating new facilities is considered with respect to existing facilities so as to minimize a sum of costs which consists of costs proportional to the rectilinear distances between new and existing facilities, and costs proportional to the rectilinear distances among new facilities. The location problem decomposes into two independent sub-problems, each of which is equivalent to a linear programming problem which is essentially the dual of a minimal cost network flow problem. Fulkerson's out-of-kilter algorithm provides an efficient means of solving each of the network flow problems as well as the location problem. The dual variables in each of the optimum tableaus to the two flow problems give the x and y coordinates respectively of the optimum locations of the new facilities. Several alternative approaches to solving the equivalent linear programming problems are also discussed, and some research questions are identified.