Saline soils in the Dry Valley region of McMurdo Sound, Antarctica, contained bacteria showing salt tolerance or requirement. Soils were plated by the spread plate method on soil extract-peptone-yeast extract media to which sodium chloride had been added in concentrations from 0 to15 per cent (w/v). Bacteria isolated from these media at 2 °C, 5 °C, and 15 °C were predominantly Gram negative rods with few Gram positive rods and cocci. No filamentous fungi or Halobacterium spp. were observed on the media used. At 15 C there were no isolates from media containing greater than 15 percent added salt; however, counts of 1.4 x 10³ colonies per gram of soil were found at this concentration. As the incubation temperatures were lowered, salt tolerance was lowered. The data indicate that the limited soil microflora observed in saline soils and ponds may be attributed to a combination of low maximal summer temperature and high salinity. / Master of Science

This dissertation deals with an analysis of impulsively loaded plastic plates that includes effects of large deformations and midplane forces. Specifically, it deals with a circular plate of uniform thickness simply supported at its edges. The impulsive loading is characterized by an initial velocity distribution. The analysis assumes that the plate is an isotropic, rigid, ideally plastic material. Shear deformations and longitudinal inertia are neglected. Both bending and midplane forces are considered. The midplane forces can be either applied prior to the impulse or generated by deformations of the midplane. Deformations of the cross section are based on the assumption that a line initially normal to the midplane remains straight and normal after deformation. Strains are nonlinear with respect to transverse displacements but contain only linear radial displacement terms. Finally, the Tresca yield criteria are used. An interaction equation is derived between the plastic moment and normal force. The relationship indicates that the greater the midplane force the smaller the required bending moment for plastic flow. When the midplane force reaches a maximum value, the plate no longer carries a moment. Equilibrium equations are derived for the motion of the plate which are consistent with the von Karman plate theory. Governing equations are then developed for the three possible phases of motion. The initial Phase 1 includes a bending hinge that travels from the support to the center of the plate. Phase 2, which is initiated when the hinge reaches the center, continues until either the motion ceases or a portion of the plate becomes a membrane. Phase 3 described the motion of the membrane hinge from its initial point of origin to its final stopping point. These governing equations are solved for two types of bending moment-midplane-force interaction relationships. One relationship is based on displacement of the neutral surface from the midplane surface. The second is based on the magnitude of the midplane forces. Both types of plastic plate behavior are examined. Plots of final central deformation for various applied midplane forces and impulses are presented that clearly illustrate that even small amounts of midplane forces have a significant effect on the final deformation of plastic plates. Numerical results of the large deformational analyses are also presented. Plots are given showing the influence of the magnitude of the impulse on bending hinge velocity, initiation of membrane behavior, location of the membrane hinge, and the final deformation of the plate. A comparison is made between results of the large deformational analysis and experimental data. It shows excellent agreement. For the small and intermediate range of impulses the agreement is within experimental scatter. For the large impulses the calculated deformations are slightly conservative. Reasons for this deviation are discussed. Finally a critical examination is made of the various other suggested approaches that have possible application to the behavior of plastic plates. / Ph. D.

Both TPN- and DPN-linked isocitrate dehydrogenases have been identified in the thoracic muscle mitochondria from the face fly and the American cockroach. The DPN-linked enzyme from these two insects is closely related on the basis of chromatographic pattern. DPN-linked IDH has been isolated from face fly thoracic muscle mitochondria and purified 50-fold from the initial mitochondria acetone powder extract in good yield (22%). The enzyme may be stored without loss of activity as a suspension in 0.3 sat. (NH₄)₂SO₄ containing 20 mM potassium phosphate, pH 7.0, for three weeks at room temperature. It was found that the enzyme requires mg⁺⁺or Mn⁺⁺ for activity, but the optimal metal ion concentration depends upon the Mg⁺⁺ or Mn⁺⁺ to substrate ratio. The optimal stimulation effect of ADP on the enzyme activity was found to be 2 mM in correlation with the concentration of DPN⁺ (4mM), isocitrate (6mM), and Mg⁺⁺(6mM) . The pH optimum varied depending on the concentrations of the reaction cofactors involved. As a result, the activity of DPN-linked IDH is pH dependent. Kinetic studies on the forward reaction revealed several interesting properties of the DPN-linked IDH. At lower pH values, the stimulatory effect of ADP on the enzyme was observed to be less than at higher pH. It has been clarified in the text that in the presence of ADP, the maximal pH shifts slightly higher". The results indicate that the stimulation provided by ADP is not solely due to the amount of ADP which participates in the reaction but is rather controlled by H+ concentration in a specific fashion. The effect of pH on the activity of DPN-linked IDH is dependent on the concentrations of isocitrate and DPN+. The enzyme is inhibited by low concentration (0.16 mM) of p-chloromercuribenzoate. Comparative kinetic studies at pH 7.0 and 6.0 reveal that the enzyme is inhibited by the reaction products. With DPNH as the variable substrate, Lineweaver-Burk plots reveal a pattern of competitive inhibition for isocitrate. Furthermore, with a-ketoglutarate as the variable substrate, Lineweaver-Burk plots reveal a pattern of noncompetitive inhibition for both DPN and isocitrate. The reaction catalyzed by purified enzymes is inhibited by ATP and EDTA. DPN-linked IDH was activated by citrate. / Ph. D.

The rates of penetration, metabolism, and excretion of DDT have been studied in vivo in resistant and susceptible strains of the German cockroach, Blattella germanica (L.). The cockroaches were exposed to various DDT treatments for intervals ranging from 3 to 72 hours. DDT and its metabolites were identified and quantitated in external, internal, and excreta fractions using gas-liquid chromatography. The identifications were verified by thin-layer chromatography. It has been shown that DDT penetration is nearly identical for the three cockroach strains used in this study (two resistant and one susceptible strain). For this reason penetration is not thought to be related to the DDT resistance mechanism in this insect. Susceptible and resistant cockroaches are both capable of converting DDT to dicofol which was the only metabolite observed. The conversion rate is somewhat faster in the resistant strains than in the susceptible strain but in no case exceeds 20% of the absorbed dose. Dicofol production reaches a maximum which is not exceeded in the presence of additional DDT. Female cockroaches of all three strains convert DDT to dicofol at a faster rate than their respective males. The inhibition of dicofol production by the synergist sesamex occurs at a high level in all strains, but results in mortality in the susceptible strain. Therefore, metabolism does not seem to be a major resistance mechanism. Excretion of unchanged DDT is apparently not related to the observed resistance levels. The excretion mechanism is, however, capable of removing much of the penetrated DDT provided the insect can survive the treatment. Excretion of DDT was consistently higher in male cockroaches than in females. The combined effects of the detoxication and excretion mechanisms are extremely efficient in removing penetrated DDT from this insect, particularly at higher treatment levels. Never-the-less, resistant cockroaches have and can apparently withstand much higher internal concentrations of DDT than susceptible cockroaches. The DDT-resistance mechanism of these cockroaches appears to be similar in nature to the unknown mechanism responsible for resistance to knockdown (Kdr) or paralysis by DDT in houseflies. This mechanism may alter the site of action of DDT and result in a reduced binding capacity of resistant insect nerve tissue for the DDT molecule as compared to susceptible insect nerve tissue. / Ph. D.

The minerals of the humite group have the formula nM₂SiO₄• M₁₋ₓTiₓ(OH₃F)₂₋₂ₓ0ₓ₂ where M is Mg, Fe, Mn, Ca, Zn in decreasing order of abundance, x < 1, and n=1 for norbergite, n=2 for chondrodite, n= 3 for humite, and n=4 for clinohumite. Description of the humites as alternating layers of forsterite (Mg₂SiO₄) and sellaite and/or brucite (MgF₂ and Mg(OH)₂) composition is incorrect because no layers with these compositions are present in the structure. The humites are structurally analogous to olivine in that both consist of a hexagonal close-packed array of anions (O, OH,F), zigzag chains of edge-sharing, M-filled octahedra and isolated Si04 tetrahedra. They differ from olivine in that none of the available tetrahedral sites coordinated by one or more OH or F anions is occupied by Si; this results in a stagger of the chains of octahedra. Substitution of Fe, Mn, and Ca for Mg has the same effect on the unit cell volume (normalized to half the mean anion-anion distance along the normal to (001)) in minerals with the humite structure as it does in minerals with the olivine structure. Fifty-five humite mineral samples have been analyzed by microprobe x-ray emission methods for F, Mg, Si, Ca, Ti, Mn, Fe, and Zn. Al, P, Cl, Cr, Co, Ni, Cu, and Pb were not detected by analysis or wavelength scanning at the less than 0.03 weight percent level. The OH⁻¹ concentrations were calculated using atomic proportions and assuming electro- static charge balance in the M₁₋ₓTiₓ(OH,F)₂₋₂ₓ0₂ₓ part of the formulae. Epitaxial intergrowths between members of the humite group have been predicted on the basis of their similar structures and wet chemical analyses. Most chemical analyses of humite minerals show substantial anion deficiencies which lead to non-stoichiometric Si:(OH + F + O_Ti) ratios; many also indicate non-stoichiometry in the olivine equivalent portion of the formula. In contrast, the microprobe analyses indicate that the humite minerals are stoichiometric. They also suggest that most bulk chemical analyses are deficient in H₂O and were made with material which contained minor amounts of other mineral impurities. Single crystal x-ray diffraction studies were made on nine microprobe analyzed humites to determine the effects of minor chemical substitution on the unit cell parameters. These studies show that the substitution of (Fe + Mn) for Mg increases the normalized cell volume; that Ti+ 2(O) for Mg + 2(OH,F) has little effect on the cell volume; and that (OH,F) + tetrahedral vacancies for 0 + Si results in a decrease in cell volume. / Ph. D.

Abandoned manganese strip mines in Smyth County, Virginia have for many years contributed pollution to the streams draining them. Streams in the Cripple Creek drainage area were sampled during the summer of 1967 to determine the nature and extent of pollution in them, and to evaluate the reclamation work being done by the United States Forest Service. Affected streams were compared with control streams on the basis of physical, chemical and biological properties. Manganese levels in all streams sampled were found to be below one part per million. A controlled experiment with Mn(NO₃)₂ showed that the median tolerance limit for rainbow trout fingerlings is about 16 ppm Mn which, together with stream sampling data, indicates that manganese is not present in toxic concentrations in the study streams. Killinger Creek, which drains a partially reclaimed area, was found to support fewer species of fish and benthic fauna than Crigger Creek, a comparable control stream. Siltation is probably the main contributing factor. Bedload was much greater in affected streams than in control streams. Although volume of bedload was high in Blue Spring Creek, which drains a reclaimed area, particle size distribution of the bedload indicates that much of the finest silt has been flushed from the upper portion of this stream. Blue Spring Creek supports an abundant population of aquatic insects and fish fauna, indicating that reclamation has been effective on this watershed. It was also found that rainbow trout are spawning successfully in this stream. / Master of Science

This thesis aims to explore and investigate the use of the cliché ‘68 in a contemporary Swedish debate. The sixties and especially 1968 is a historically significant year,and it is marked by political murders, protesting students and political energy. InSweden one of the most notable happenings was the occupation of the student union’s headquarters in Stockholm. The occupation, which was held by the students, lasted for three days and was initiated during a meeting to discuss a parliament proposal of regulated courses of studies, known as UKAS. In 2008, during the jubilee forty years after the occupation, a seminar was arranged by the cultural conservative forum Axessat the very same address where the student union’s headquarters once had been. The seminar is characteristic for the research material: It exemplifies how the leftist symbol ‘68 is used and transformed by participants who do not define themselves as left-wing. The purpose of this paper is to show how ‘68 as a cliché is used not to challenge thepolitical situation of today, but to present the discoursers and their political views asneutralised or natural. The hypothesis of this study is that ‘68 serves as a hegemonical gap, where leftist political values can absorb a minor part of the debate — just to bemarked off as something caused almost biological by youth, and placed in a largerscheme where the participants in forums, such as the seminar arranged by Axess, are acknowledged as judges of society both now and then, and as su neutralised. The cliché ‘68 can be positioned in the debate concerning the post-political society. Part ofthe cliché is the historical narrative where society evolves from immature to mature,from radical leftist to non-socialist and right-wing stands.

Th.--Lettres--Strasbourg, 1968. / Bibliogr. p. 485-497.

No description available.

Doctorat en sciences sociales, politiques et économiques / info:eu-repo/semantics/nonPublished