Showing papers by "University of Notre Dame published in 1978"

The distribution of heavy metals in anaerobic digestion

Abstract: In recent years, there has been a great deal of interest in the distribution and effects of influent wastewater heavy metals in conven tional wastewater treatment. Of the various process components of conventional waste water treatment, anaerobic digestion appears to be particularly vulnerable to excessively high heavy metals loadings to the treatment plant. The widespread use of anaerobic di gestion in the treatment of wastewater sludges has underscored the importance of under standing the various control problems caused by high heavy metal concentrations in treat ment plant sludges fed to anaerobic digesters. This study was undertaken to observe the ef fects of heavy metals on bench-scale anaerobic digesters and to determine the distribution of these metals among various forms in the digester.

Splitting of certain spaces CX

Abstract: There are a number of theorems to the effect that spaces of the form ΩnσnX split stably into wedges of simpler spaces when X is connected (by which we mean pathwise connected). The proofs generally proceed by exploitation of combinatorially manageable approximations for ΩnσnX.

Examination of stimulus persistence as the basis for superior visual identification performance among older adults.

Abstract: Visual identification performance of sequentially presented corresponding word-halves was studied in 12 young (mean 18.9 years, range 18-21) and 12 old (mean 68.0 years, range 59-78) male and female subjects. Corresponding word-halves were composed of straight horizontal and vertical line segments and when superimposed tachistoscopically formed clear, fully closed 3-letter words. Stimulus duration and interstimulus interval (ISI) were systematically varied. Correct word recognition was found to be an inverse function of ISI and stimulus duration for both young and old subjects. An interaction was found between age, sex, and stimulus duration. Recognition scores were significantly higher among older subjects, an effect which was particularly prominent at greater ISIs. The data offer strong support for the stimulus-persistence model as applied to age differences in the sequential integration of form.

Pulse radiolysis studies in model lipid systems: formation and behavior of peroxy radicals in fatty acids

Abstract: — Radiolytic formation and peroxidation of fatty acid radicals have been investigated by pulse radiolysis techniques in oleate, linoleate, linolenate and arachidonate systems. A strong absorption band at 280 nm associated with conjugated radicals, Rconj, formed in polyunsaturated fatty acid moieties has been used as a probe for kinetic processes occurring at doubly allylic sites in the hydrocarbon chain. Formation of Rconj by O- has been found to be more efficient than the less selective OH radical. Peroxidation of Rconj is shown to be somewhat slower, (kR+ O2˜ 3 × 108M-1 s-1), than O2 reactions with radicals in oleate (kR+ O2= 1 × 109M-1 s-1). Peroxy radicals generated in these reactions disappear slowly by essentially second order processes (2kRO1˜ 107M-1 s-1). The superoxide radical, O-2, shows little if any reactivity towards 0.01 M linolenate or arachidonate over periods of 20 s.

Ability and Responsibility

Abstract: La liberte ou la necessite? H. Frankfurt, "Alternate Possibilities and Moral Responsibility" (Journal of Philosophy, LXVI, 1969, p. 829-839) reitere une telle alternative dans ce qu'il appelle le principe de possibilite alternee ou morale: une personne est moralement responsable de ce qu'elle a fait seulement si elle aurait pu faire autrement. L'A. discute et critique cette conception en essayant de formaliser les idees morales.

Urban Folk Medicine: A Functional Overview

Abstract: Social and economic functions of folk illness and folk medicine are fairly well known for rural contexts but still lack codification for urban milieus. In this exploratory paper, folk health practices are examined in terms of their response to urban socioeconomic characteristics. Such practices appear to serve functions of acculturation, guilt displacement resulting from failure to achieve, and subgroup identity maintenance, among others. Folk practices are resilient, readily shifting to adjunct functions of healing under pressure from effective modern medical and welfare systems. [medical anthropology, urban anthropology, curanderismo, ethnology, health]

Genetics of house-entering behaviour in East African populations of Aedes aegypti (L.) (Diptera: Culicidae) and its relevance to speciation

Abstract: Samples of larvae of Aedes aegypti (L.) were collected in three principal habitats, domestic, peridomestic and feral, in the Rabai area in eastern Kenya. The samples from the domestic habitat represent the population of the domestic form, A. a. aegypti, and the feral samples from tree holes from Bejumwa Forest represent the feral subspecies, A. a. formosus (Wlk.). The peridomestic samples from steps cut into trunks of coconut palms most probably represent hybrids between the domestic and the feral forms. These samples were brought to the laboratory where they reproduced in high numbers, and crosses were made between the three populations. Adults of the parental populations and those resulting from the crosses were marked with different colours of fluorescent pigments, released in the peridomestic habitat in the Rabai area and subsequently recaptured in biting catches on man in the domestic and peridomestic habitats. The results indicate that domesticity, particularly house-entering behaviour, in A. aegypti is genetically controlled and is a product of the action of several genes. The gene action in terms of house-entering behaviour is additive as can be clearly seen from the recapture data for the various crosses. The percentage entering houses was highest among mosquitoes of the form from inside houses (the domestic A. a. aegypti population (D)) and the percentages decreased progressively through the peridomestic (P) and hybrid forms to the feral population of A. a. formosus (F) in the following manner: D (45·)DP (15 ·5), PD (13·9), P (9·8), DF (5·7), FD (73·), PF (1·5), FP. (0·6) and F (0·6).The recaptures outdoors were in the reverse order, the highest percentage being for F (187·) and the lowest for D (8·5), DP (8·0) and PD (7·7). The data suggest that the larvae from the peridomestic habitat may represent hybrids between the domestic and feral formsA model for the inheritance of behavioural characters in mosquitoes is presented. On the basis of isolating mechanisms and partial hybridisation, it is concluded that A. a. aegypti and A. a. formosus have developed as geographically isolated allopatric populations. This supports the existing polytypic concept of speciation in A. aegypti. Spatial distribution, non-random mating and the existing series of isolating mechanisms indicate that the domestic type form has been introduced into East Africa, most probably on ships.

Inverse attribute functions and the proposed modifications of the power law

Abstract: Three prominent modifications of Stevens’ power law, designed to account for the curvature at low stimulus intensities, were examined in the light of previously reported inverse attribute functions and five new experiments scaling loudness and softness by magnitude estimation. One hundred and seven students served as observers in the five experiments. Lack of curvature in the inverse functions at low stimulus intensities, plus the lack of parameter invariance, pointed to the inadequacy of the effective threshold and physiological noise modifications. The additive constant model of zero-point response bias, previously advanced by Irwin and Corballis (1968)and McGill (1960)was found more satisfactory. A discussion of the implications of the research findings for subsequent formulations of the modified power law was included.

The Role of the Thermal Hysteresis Factor in Tenebrio Molitor Larvae

Abstract: The haemolymph of larvae of Tenebrio molitor contains a factor which produces a thermal hysteresis (a difference between the freezing and melting points) of approximately 0.75 °C. When larvae were acclimated to low temperatures or short photoperiod the thermal hysteresis increased more than twofold. Coincident with the increase in thermal hysteresis the supercooling points and lower lethal temperatures of the larvae were depressed. Therefore, the thermal-hysteresis-producing factor seems to function as an antifreeze. The factor may also act as an adaptation to prevent desiccation. Thermal hysteresis increased almost three-fold in larvae acclimated to low relative humidity. Also, larvae with high levels of the thermal hysteresis factor survived low relative humidities much better than did larvae with lower levels.

Pulse Radiolysis Studies in Model Lipid Systems. The Influence of Aggregation on Kinetic Behavior of OH Induced Radicals in Aqueous Sodium Linoleate

Abstract: The kinetic and spectral behavior of radicals formed by hydroxyl radical attack on linoleate anions has been studied by pulse radiolysis. Reactivity of ·OH toward this surfactant is an order of magnitude greater in monomeric form [k·OH+linoleate = 8.0 ± 109 M−1 sec−1] than in micellar form [k·OH+lin(micelle) = 1.0 ± 109M−1 sec−1]. Abstraction of a hydrogen atom from the doubly allylic position gives rise to an intense absorption in the UV region (δmax = 282–286 nm, e 3·104 M−1 cm−1) which may be used as a probe of radical activity at that site. This abstraction may occur, to a small extent, directly via ·OH attack. However, greater than 90% of initial attack occurs at other sites. Subsequent secondary abstraction of doubly allylic H atoms appears to occur predominantly by: (1) intramolecular processes in monomers, (2) intermolecular processes in micelles. Disappearance of radicals by secondary processes is slower in the micellar pseudo phase than in monomeric solution. Die kinetischen und spektralen Eigenschaften von Radikalen, die durch die Reaktion von OH-Radikalen mit Linoleat-Anionen entstehen. wurden mit der Pulsradiolyse untersucht. Die Reaktivitat von OH ist gegenuber dem monomeren Linoleat-Anion etwa eine Grosenordnung groser (kOH + Linoleat = 8,0 · 109 M−1 s−1 als gegenuber der mizellaren Form (kOH+Lin(Mizelle) = 1,0 · 109 M−1 s−1). Abspaltung eines Wasserstoffatoms von der zweifachen Allylposition fuhrt zu einer intensiven Absorption im UV-Bereich (δmax = 282-286 nm, · 104 M−1), die als Sonde fur die Radikalaktivitat an dieser Stelle dienen kann. Mehr als 90% der OH-Radikale greifen jedoch an anderen Stellen des Molekuls an. Die darauf folgende sekundare Abspaltung von H-Atomen in der zweifachen Allylposition scheint hauptsachlich durch 1) intramolekulare Prozesse in Monomeren und 2. intermolekulare Prozesse in Mizellen zu erfolgen. Das Verschwinden von Radikalen durch Sekundarprozesse geschieht in der mizellaren Pseudophase langsamer als in der monomeren Losung.

The Conception of Science in Galileo’s Work

Abstract: It has been remarked more than once that each generation of theorists of science makes of Galileo, the “father of modern science” by customary reckoning, a scientist after its own heart.1 Most recently Paul Feyerabend proposed that: What Galileo did was to let refuted theories support each other, that he built in this way a new world-view which was only loosely (if at all!) connected with the preceding cosmology (everyday experience included), that he established false connections with the perceptual elements of this cosmology which are only now being replaced by genuine theories (physiological optics, theory of continua), and that whenever possible he replaced old facts by a new type of experience which he simply invented for the purpose of supporting Copernicus.2

Relativistic Effects on Low-Energy 5 s → ε p Photoionization for Xenon

Abstract: Under suitable conditions, relativistic corrections to the interaction of a photoelectron with its parent ion are enhanced, giving rise to large anisotropic final-state effects which can be observed in the photoelectron angular distribution. The particular example of $5s\ensuremath{\rightarrow}\ensuremath{\epsilon}p$ photoionization of Xe is considered in detail. It is shown that the angular asymmetry parameter $\ensuremath{\beta}$ is reduced by a factor of 9 from its nonrelativistic value of 2 near the $5s$ "Cooper minimum," so that the energy dependence of $\ensuremath{\beta}$ becomes a sensitive test of atomic correlation theories.

Field investigation of trace metals in groundwater from fly ash disposal

Abstract: A ponded flyash disposal site is studied in detail. Emphasis is on the extent of trace metal migration in groundwater from natural seepage. The investigation is conducted at Northern Indiana Public Service Co.'s Michigan City coal-fired generating station. Trace metals are released into the groundwater in low concentrations. (3 diagrams, 10 graphs, 21 references, 6 tables)

On Non-Compact Complex Nil-Manifolds

Abstract: Given a complex manifold X, it is natural to consider the quotient space X~ ~, where p~q whenever f(p)=f(q) for every fe(9(X). In the best of all worlds one would hope that X / ~ is a Stein space, and that there are no non-constant holomorphic functions on the equivalence classes of ~ . One would also hope to explain the latter phenomenon by compactness or Levi curvature. A classical result of this type is the Remmert Reduction Theorem: If X is an irreducible, holomorphically convex analytic space, then X / ~ is a Stein analytic space and the natural holomorphic separation map F : X ~ X / ~ is proper [15]. In general it is not possible to prove any such reduction theorem. In fact there are naturally occuring manifolds X where there is no natural way to put a complex structure on X~ ~ [5]. Grauert's examples [5] all contain non-compact divisors on which every holomorphic function is constant. Off these divisors the holomorphic functions separate points and give local coordinates. If one assumes that X is homogeneous, then of course X can't be one of Grauert's examples. For the purposes of this paper, homogeneity means that a complex Lie group G acts holomorphically and transitively on X. In other words X is holomorphically equivalent to G/H, where G is a connected complex Lie group and H is a closed subgroup of G. One would hope to obtain some form of a reduction theorem in the homogeneous setting. It is true that the holomorphic separation map of a complex homogeneous manifold can always be realized as a holomorphic fibration over a holomorphically separable homogeneous manifold. However, we do not even know if a holomorphically separable homogeneous manifold always has an envelope of holomorphy. Clearly it need not be Stein, e.g. ~2\{(0,0)}. Also the fiber of the holomorphic separation map may have nonconstant hotomorphic functions (see [2]). In particular cases, some results have been obtained. Morimoto [13] showed that if G is a connected, complex Lie group, then it has a closed, connected, central,

Giemsa C-banding patterns in Aedes (Stegomyia) mosquitoes

Abstract: Chromosomes from gonads of 14–24 h old pupae of nine species of Stegomyia mosquitoes have been examined using the Giemsa C-banding technique The species studied were Aedes albopictus, A polynesienis, A scutellaris, A alcasidi, A seatoi, A pseudalbopictus, A melallicus, A annandalei and A vittatus The diploid chromosome number of all species is six All species possess C-bands in the centromeric regions of each of the three pairs of chromosomes Besides, an intercalary C-band is present on the female determining (=m) chromosome but absent from the male—determining (= M) chromosome of all species except A vittatus In A vittatus, the m and M chromosomes possess a terminal C-band Thus, the nine species of Aedes analysed showed two distinct patterns of C-banding —The evolution of heterochromatin patterns in various species is also discussed The Giemsa C-banding technique should prove useful in studies of chromosomal speciation in culicine mosquitoes

Interference with avoidance behavior as a function of qualitative properties of inescapable shocks

Abstract: Temporal form (continuous vs pulsating) and shock source (alternating current vs direct current) were factorially combined to produce four shock treatments The effects of inescapable presentations of these stimuli on subsequent avoidance response acquisition were measured in dogs (Experiment 1) and in rats (Experiment 2) and revealed an interaction of shock variables Initially, all groups that received ac shock showed impaired performance for the pulsating and continuous shock conditions; groups that received dc continuous shock were also impaired, while those that received dc pulsating shock were not While this pattern of interference persisted for dogs, it was transient in rats, with only the ac continuous-shock group continuing to be impaired Mean avoidance performance were positively related to mean activity levels during inescapable shocks for the dc shock groups but not for the ac shock groups