Showing papers by "University of Rhode Island published in 1973"

Iceland Mantle Plume: Geochemical Study of Reykjanes Ridge

Abstract: Systematic rare earth and minor element concentration variations in basalt recently erupted along the post-glacial Reykjanes Ridge Axis and its northward extension over Iceland reflect the existence, spatial influence, and primordial nature of the Iceland hot mantle plume.

CHILD ABUSE AS PSYCHOPATHOLOGY: A Sociological Critique and Reformulation

Abstract: Book reviewed in this article: Much of the current research on child abuse employs a psychopathological model, which explains child abuse as a function of a psychological pathology, or a “sickness.” This paper asserts that major deficiencies of this model are its inconsistency and narrowness. It is suggested that a more dimensional approach to child abuse is possible by focusing on the sociological and contextual variables associated with abuse.

Basalts from Iceland and Along the Reykjanes Ridge: Sr Isotope Geochemistry

Abstract: Strontium isotope ratios in basalts demonstrate two distinct mantle sources under Iceland and the Reykjanes Ridge.

Vesicles, water, and sulfur in Reykjanes Ridge basalts

Abstract: Dredge hauls of fresh submarine basalt collected from the axis of the Reykjanes Ridge (Mid-Atlantic Ridge) south of Iceland were taken aboard R/ V TRIDENT in 1967 and 1971. The samples show systematic changes as the water depth of collection (and eruption) decreases: radially elongate vesicles and concentric zones of vesicles appear at about 700 m depth and are conspicuous to shallow water; the smoothed volume percent of vesicles increases from 5% at 1000 m, 10% at 700 m, to 16% at 500 m, and the scatter in degree of vesicularity increases in shallower water; specific gravity decreases from 2.7±0.1 at 1000 m to 2.3±0.3 at 100 m. Bulk sulfur content for the outer 2 cm averages 843 ppm up to a depth of 200 m, then drops off rapidly in shallower water owing to degassing. Sulfur content below 200 m is independent of depth (or geographic position), and the melt is apparently saturated with sulfur, but the excess cannot escape the lava unless another vehicle carries it out. Only shallower than 200 m, where intense vesiculation of other gases occurs can excess sulfur be lost from the lava erupting on the sea floor. H2O+110° averages about 0.35 percent and H2O+150° about 0.25 percent, and both apparently decrease in water shallower than 200 m as a result of degassing. H2O+ (below 200 m) decreases with distance from Iceland or increasing depth, presumably as a result of either adsorption of water on the surface of shallower, more vesicular rocks; or more likely due to the presence of the Iceland hot mantle plume supplying undifferentiated primordial material, relative to lavas of the Reykjanes Ridge supplied from the low velocity layer already depleted in volatiles and large lithophile elements. The H2O+110°/S ratio of lava erupting below 200 m water depth ranges from 3 to 5 which is comparable to reliable gas analyses from oceanic basaltic volcanoes.

Evaluation of Mott's Parameters for Hopping Conduction in Amorphous Ge, Si, and Se-Si

Abstract: The temperature dependence of electrical conductivity of rf-sputtered amorphous Ge, Si, and Ge-Si films as functions of annealing temperature and time have been investigated for $350\ensuremath{\gtrsim}T\ensuremath{\gtrsim}77$ K. Annealing shifts the hopping region to lower temperatures. We find that reasonable values of Mott's parameters are obtained only for properly annealed specimens in the true hopping-conduction region.

Iceland Mantle Plume

Abstract: O'HARA1 has objected to my interpretation concerning the trace element chemistry of lavas erupted along the Iceland-Reykjanes Ridge System2 on the ground that: (1) Such magmas are not “primary magmas” but residual liquids; (2) instead, such lavas have suffered prior to eruption extensive “gabbro fractionation” at low pressure (olivine-augite-plagioclase extraction), and/or “eclogite fractionation” at higher pressure (clinopyroxenegarnet extraction in a 50–50% mixture); (3) the “extent of fractionation” is directly proportional to the elevation of the surface on which these lavas have been erupted, thus increases toward Iceland, and is the principal cause of trace element variations along the ridge. According to O'Hara, the lavas are derived from a unique and homogeneous mantle at the upper mantle-transition zone boundary and not, as I prefer2, from two distinct mantle sources, one forcefully rising as a primary hot mantle plume (PHMP) beneath Iceland and interacting with the depleted low velocity layer (DLVL).

Afar Mantle Plume: Rare Earth Evidence

Abstract: Rare earth pattern zonation about the Afar Triangle, in tholeiitic basalts erupting along the Red Sea Trough and the Gulf of Aden, suggests the presence of a primordial mantle plume rising beneath the Afar and overflowing in a star-like fashion into the soft asthenosphere.

Association of Hydrocarbons and Mineral Particles in Saline Solution

Abstract: WE report evidence confirming the suggestion that the partial dissolution in seawater of fuel oil hydrocarbons is important in the degradation of this petroleum product in the marine environment1. Our experiments show that hydrocarbon solubility affects uptake and retention of fuel oil by marine sediments and that organic matter in sediments reduces the incorporation of fuel oil into the sediment samples investigated.

Effect of dopaminergic stimulation or blockade on morphine-withdrawal aggression.

Abstract: Aggregation during morphine abstinence elicited social aggression (rearing, vocalization, attack-bites) in the morphine dependent rats. Pretreatment with l-dihydroxyphenylalanine (50 mg/kg), dl-dihydroxyphenylalanine (200 mg/ kg), dextro-amphetamine sulfate (2 mg/kg) or apomorphine hydrochloride (1.25 mg/kg) enhanced that aggression severalfold. Alpha methyl-p-tyrosine (200 mg/kg) abolished the morphine withdrawal aggression that was elicited either by mere aggregation or by aggregation combined with amphetamine. However, alpha methyl-p-tyrosine did not block the aggression in apomorphine treated rats. Haloperidol (0.63–2.5 mg/kg) also blocked the aggression due to mere abstinence or abstinence supersensitized by amphetamine. Similarly, methadone hydrochloride (5–20 mg/kg) blocked morphine withdrawal aggression supersensitized by apomorphine. These data are interpreted to suggest dopaminergic basis of morphine withdrawal aggression and a latent supersensitivity of dopaminergic neuropathways during morphine dependence.

Lifetime of adrenal cytochrome p‐450 as influenced by acth*

Abstract: ACTH can stimulate adrenal steroid production within a short time period, or maintain corticosteroidogenesis over long periods of time. The mechanism of the short-term, or tropic, action of ACTH seems to involve the synthesis of a short-lived protein which can specifically stimulate glucocorticoid production within 15 min,'.* presumably at the rate-limiting step, the side-chain cleavage of cholesterol to pregnen~lone.~ The long-term, or trophic, action of ACTH involves the maintenance of both adrenocortical integrity and an increased steady-state secretion of glucocorticoids. While the puzzle of the tropic effect of ACTH may be closer to solution, less is known about the trophic effect of ACTH on the components of steroid hormone synthesis. It has been well documented that ACTH is able to prevent the extensive atrophy of the cells in the adrenal zona fasciculata which occurs after hypophysectomy.' At the fine structural level, however, studies reported within the past 15 years on the effect of hypophysectomy and ACTH treatment have been, in general, contradictory and inconclusive (they are extensively reviewed by Idelman'). Recently, Canick and Purvis' investigated the trophic effect of ACTH on the size and number of mitochondria of the zona fasciculata. It was reported that ACTH appears to maintain mitochondrial size and number by controlling mitochondrial growth and division. Nussdorfer and colleagues' have shown that the administration of ACTH to normal rats over long time periods caused substantial proliferation of the smooth endoplasmic reticulum (SER) as well as a small but significant increase in mitochondrial volume. Both the mitochondria and the SER are directly involved in corticoid synthesis, since all the enzymes in the oxidative pathway from cholesterol to corticoids are located on these membranes (this is reviewed by Savard'). Kimura\" has investigated changes in various adrenal enzymes after hypophysectomy and subsequent ACTH treat-

Theory of the Temperature Derivative of the Refractive Index in Transparent Crystals

Abstract: A simplified model is introduced to study the temperature dependence of the index of refraction $n$ in the transparent regime of crystals The dielectric susceptibility is written as a sum of an electronic contribution due to band-to-band transitions and a lattice contribution, viewed as due to a single mode ${\ensuremath{\omega}}_{0}$ Each of the latter undergoes a temperature variation consisting of contributions due to thermal expansion, as well as contributions due to the explicit temperature dependence at constant volume The temperature derivative $\frac{\mathrm{dn}}{\mathrm{dT}}$ is investigated for various materials It is found that for zinc-blende- and diamond-type semiconductors, electronic effects, in particular the temperature variation of the band gap at constant volume, yield the dominant contribution Theoretical calculations of the latter are carried out employing a temperature-dependent-pseudopotential band-structure model; the resulting values for $\frac{\mathrm{dn}}{\mathrm{dT}}$ are in good agreement with experiment For ionic materials, it is found that both lattice and electronic contributions may be important, as are both explicit temperature variation and thermal-expansion effects Experimental data on the temperature dependence of ${\ensuremath{\omega}}_{0}$ and the band gap are employed to obtain good agreement with the frequency variation of $\frac{\mathrm{dn}}{\mathrm{dT}}$ for a variety of ionic crystals The results demonstrate that the major physical mechanisms responsible for $\frac{\mathrm{dn}}{\mathrm{dT}}$ can be understood within the present simplified model, and that the model is useful in predicting the magnitude and frequency dependence of $\frac{\mathrm{dn}}{\mathrm{dT}}$ for a wide variety of crystals of interest

Fouling on eelgrass (zostera marina l.)1

Abstract: SUMMARY The diatom Cocconeis scutellum (Meunier) colonizes the surface of young plants emerging from the mud in the spring and the usually emersed plant tips as they are knocked over and become immersed in the fall to form a virtually unialgal mat. Broken frustules and detritus adhere to form a crust which then becomes colonized nonselectively by a variety of microorganisms. Removal of the crust shows that the original “cobblestone” surface of the eelgrass is obscured with a layer of deformed cells of C. scutellum which appears to be impressed into the epithelium.

Cytological sexing of cetacea

Abstract: A biopsy dart, that can be shot from a gun or crossbow, was developed to obtain skin of whales at sea. Determination of sex was found possible by staining and locating sex chromatin bodies in the nuclei of female skin cells. This procedure will be useful in many types of field studies on whales.

Testicular cytochrome P-450 and iron-sulfur protein as related to steroid metabolism.

Abstract: It has been known for a considerable time that testicular mitochondria contain the enzyme system that converts cholesterol to pregnenolone.' This enzyme in adrenal mitochondria has been shown to involve cytochrome P-450 and an iron-sulfur protein, adrenodoxin, as well as a FAD-containing flavoprotein, NADPH-adrenodoxin reductase? Adrenocortical mitochondrial cytochrome P-450 and adrenodoxin, components of the mitochondrial steroid 1 lp-hydroxylase: as well as the cholesterol side-chain cleavage enzyme system, have been the objects of intensive study, as is evidenced by other papers at this symposium. Considerable difficulty has been found, however, in detecting and characterizing cytochrome P-450 in testis mitochondria.' Cytochrome P-450 is conventionally determined by optical difference spectrophotometry, using the method of Omura and Sato," which utilizes the reduced carbon monoxide complex of the pigment. Cytochrome a3, associated with the respiratory chain, however, also combines in its reduced form with carbon monoxide. The difference spectrum of electron transport particles (ETP) from beef heart mitochondria in which the pigments are reduced and then complexed with carbon monoxide is shown in FIGURE 1. It is obvious that the large negative absorption at 450 nm associated with the CO complex of reduced cytochrome oxidase will perturb the cytochrome P-450 difference spectrum, the amount of perturbation depending on the relative molar amounts of cytochrome P-450 and cytochrome oxidase. FIGURE 2 shows the difference spectra obtained with the reduced pigments in the presence of carbon monoxide when increasing amounts of ETP are added to a rat liver microsomal preparation containing cytochrome P-450. It can be seen in TABLE 1 that cytochrome oxidase perturbs the absorbance maximum of cytochrome P-450 to higher wavelengths as well as decreasing the 450 490 nm absorbance difference contribution of the cytochrome P-450. Cytochrome P-450 can be quantitated under such conditions, as described by Kowal and colleagues," by determining the 460 minus 490 nm absorbance change, using an extinction coefficient of 52 cm-' mM-', since the difference spectrum of reduced and CO-complexed cytochrome oxidase has only a small spectral contribution in this region. This experiment illustrates the point that one

Aquatic Respiration: An Unusual Strategy in the Hellbender Cryptobranchus alleganiensis alleganiensis (Daudin)

Abstract: Separate and simultaneous determinations of aerial and aquatic gas exchange in the giant salamander, Cryptobranchus alleganiensis alleganiensis (Daudin) were made at 5°, 15°, and 25°C. The aquatic respiration of this animal accounts for over 90 percent of the total volume of oxygen consumed and 97 percent of the total volume of carbon dioxide released at all temperatures. The lungs of these individuals are large transparent sacs which are poor respiratory organs; the lungs probably function more as hydrostatic structures than as gas exchangers. This animal is the largest aquatic vertebrate that lacks gills and yet utilizes almost exclusively an aquatic mode of respiration. Specialized cutaneous modifications, a unique body form, and a peculiar behavioral mechanism are of considerable adaptative significance, and confer to the skin the effectiveness of a veritable "gill."

An electron microscopy study of chip formation

Abstract: Chip formation or metal cutting is a unique large strain, high strain rate plastic deformation process. Almost all the previously reported studies of chip formation have examined the problem from the point of view of the mechanics of the deformable bodies using the mathematical theory of plasticity. This study, recognizing the heterogeneous nature of chip formation as encountered in course of machining metals, examines the problem from the metal physical or metallurgical view point. Electron microscopy studies were carried out on steel as well as nonferrous metal chips produced by shop machining conditions and compared to those chips produced by ultramicrotomy. This thin film orthogonal cutting process was employed to produce chips for microscopic examinations under well controlled and repeatable experimental conditions. The experiments carried out were designed to clarify the details of the heterogeneous plastic deformation activity occurring on the microscopic level during machining. The morphological (external surface) characteristics of the chips observed with the scanning electron microscope were correlated with the internal, dislocated structure of the chips observed by transmission electron microscopy methods. The effect of a stacking fault energy (SFE) change in an Ag-Sn alloy on chip thickness ratio(ν t) is presented for the first time, demonstrating that this deformation process is sensitive to changes in SFE. The essentially discontinuous nature of the chip formation process observed by scanning and transmission electron microscopy is analyzed with a model involving dynamic dislocation behavior in a metal in the presence of large energy dissipation arising from plastic flow to account for the observed instability.

Aristotle's Account of Incidental Perception

Abstract: A lthough there has been renewed interest in Aristotle's theory of perception, not much attention has been paid to his treatment of perception of the incidental sense-objects.' It is the primary purpose of this paper to draw a clearer account of his thought on this matter. Commentators on De Anima have usually believed that Aristotle does not hold that incidental perception is a case of pure aisthesis but rather a complex sort of psychic functioning involving thought or memory or both, as well as perception.2 Moreover, whatever faculties are thought to contribute to incidental perception, it is generally believed that this process is the cognition (or recognition) of particular things or persons (viz. individual substances) alone.3 In addition, the general lack of interest in this topic has perhaps been responsible for the apparent further view I assume this from silence on the matter that incidental perception is not of central importance in Aristotle's psychology.4 I shall dispute the first two of these positions. I believe it can be shown that Aristotle (1) does hold that incidental perception is a case of aisthesis alone and (2) that possible incidental sense-objects include more than particular substances. But I shall conclude with the further claim that incidental perception is of no less importance than perception of special and common objects in Aristotle's psychology and thought in general.

The Equation x′(t) = ax(t) + bx(t − τ) With “Small” Delay

Abstract: (1973). The Equation x′(t) = ax(t) + bx(t − τ) With “Small” Delay. The American Mathematical Monthly: Vol. 80, No. 9, pp. 990-995.

Species of oceanic dinoflagellates in the genera dissodinium and pyrocystis: interclonal and interspecific comparisons of the color and photon yield of bioluminescence1

Abstract: SUMMARY We have examined aspects of the bioluminescence of 5 clones of Dissodinium, 1 clone of Pyrocystis acuta, 4 clones of Pyrocystis fusiformis, and 5 clones of Pyrocystis noctiluca. All clones produced the same color bioluminescence with an intensity peak near 474 nm. The in vivo emission spectra of these clones agreed with those previously determined, for 4 other species of marine dinoflagellates. The amount of light emitted by the dinoflagellates in scotophase when mechanically stimulated to exhaustion was determined for most of the clones. The largest species, P. noctiluca and P. fusiformis, emitted 37–89 × 109 photons cell−1 and 23–62 × 109 photons cell−1, respectively, about a thousand, times as much light as Gonyaulax species. Pyrocystis acuta emitted 3–6 × 109 photons cell−1. Three of the 5 clones of Dissodinium were bioluminescent. The range for 3 clones was 5–13 × 109 photons cell−1. All 5 clones of Dissodinium are morphologically distinct. Both the clones of Dissodinium and Pyrocystis produced much higher numbers of photons per cell nitrogen (ca. 7–50 times) than Gonyaulax polyedra or Pyrodinium bahamense. The data suggested that enzyme turnover occurred in the reactions producing light during mechanical stimulation of Dissodinium and Pyrocystis species.