A sample of [

3H

] tobrarnycin (

5

, 000 Ci/Mole) has been synthetized and incubated with
the bacterial ribosome and its subunits. The results obtained show that this antibiotic has
two types of binding sites. The primary one is probably responsible for the inhibition of
protein synthesis whereas the secondary one is probably related to the misreading and reading
tiirough of the messenger RNA.

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A comparative study of the static and dynamic response of a slope is carried out, using the large deformation theory of the updated Lagrangian formulation and the conventional infinitesimal theory. In the static analysis, a strength reduction method proposed by one of the authors is used to evaluate the safety factor of the slope. It is found that by the large deformation theory, the safety factor is larger than that calculated by the infinitesimal theory, and this difference becomes large along with the reduction of elastic modulus. In the dynamic analysis, it is observed that the large deformation theory gives smaller sliding displacement and larger response acceleration than the infinitesimal approach. It is concluded that in many cases the large deformation approach gives more adequate solutions.

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Based on the concept "intermediate soil wedge" which is dependent on mobilized frictional resistance, a new theory has been developed for evaluating the seismic earth pressures against retaining walls under any condition between the active and passive states. For this theory, the seismic earth pressure is separated into four components according to their formation. New equations are proposed to determine the distribution, resultant and point of application for each component. An equivalent seismic coefficient is introduced to take into account non-uniform seismic acceleration distribution with depth. The equations place special emphasis on dependence of the seismic earth pressure on mode and level of wall movement. The equations can be reduced to the Mononobe-Okabe equation for the limiting conditions. Their applicability was confirmed by comparing the predictions with a number of previous model test results.

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A finite element model capable of taking into account nonlinear hysteretic soil behavior is presented to study earthquake induced retaining wall movement. The model also accounts for increase in lateral stresses and settlement associated with grain slip caused by cyclic loads. The predictive capability of the proposed method is verified by comparing responses given by the model with those computed by another existing finite element model and also with responses recorded at the Cambridge centrifuge facility. The study reveals that the wall displacement can be substantially affected, among other factors, by the increase in lateral stresses due to grain slip and wall-soil friction. Care should be taken when selecting a constant value of wall-soil friction angle for the entire duration of excitation since structural changes can occur in the soil adjacent to the wall.

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(

3H

) Tobramycin was used as a probe to determine the relationship between the structure of aminoglycoside antibiotics and their ability to remove this drug from its higher affinity binding site on the ribosome. The dissacharide moieties (neamine, tobramine, gentamine) appeared to have a common binding site, whereas the kanosamine, garosamine and ribose moieties determined the specificity of this binding. Amikacin and butikacin behaved in an anomalous manner in spite of their close structural relationship to tobramycin.

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The ability of Climacodon septentrionalis to immobilize and kill a mycophagous nematode (Aphelenchoides sp.) in vitro is described for the first time. Two isolates produced droplets (20–45 μm in diameter) that formed at the apices of tall, stalked, and branching secretory cells (700–1,500 μm tall). On

% modified malt extract agar, nematodes became enveloped in the droplets, which restricted their ability to move and resulted in complete immobilization and death within several hours of contact. The rate of decomposition of the nematodes varied considerably, with most individuals persisting for weeks whereas others were degraded within several days and appeared to be colonized by dense hyphal growth. This study provides the first documentation of a non-agaricoid fungus producing secretory cells that are able to immobilize nematodes.

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-Benzyl-4-chloro--mercapto- (H)-pyridazinone (1) was heated in ethanol under reflux for 10 hours to form concurrently , -dibenzyldipyridazo [4, - : 4', '-]-1, 4-dithiin-1, 6 (H, H)-dione (Ia) (57% in yield) and , -dibenzyldipyridazo [4, - : 4', '-]-1, 4-dithiin-1, (H, H)-dione (IIa) (14% in yield). Assignment of the two products to the corresponding structures is established by their physico-chemical constants and chemical behaviors. The concurrent formation of the dipyridazo [4, - : 4', '-]-1, 4-dithiin-1, 6 (H, H)-dione and the -1, (H, H)-dione were observed in, not only heating 4-chloro--mercapto- (H)-pyridazinones (1-) in polar solvent, but warming 4-mercapto--chloro- (H)-pyridazinones (4-6) in the presence of potassium carbonate in DMF. For the interpretation of the reaction, keto-thioketo carbenes as active intermediate species and a reversible interconversion among them are suggested on the basis of the fact that there was nonexistence of an equilibrium between the two compounds, such as Ia and IIa, under the reaction condition and a trapping keto-thioketo carbene species as -phenylimino--benzylpyridazo [4, -d]-1, -dithiol-4 (H)-one (IVa) (14% in yield) along with the major products, (Ia) and (IIa), was furnished by warming 1 with phenylisothiocyanate in the presence of triethylamine in dry benzene. On the contrary, participation of a reversible interconversion between Ia and IIa, to a considerable extent, with the concurrent formation of them in the case of benzylation of either Ib or IIb, by warming with benzylchloride in the presence of potassium carbonate in DMF at 80°, might not be neglected, because an attempted approach to an equilibrium between Ia and IIa in a similar reaction condition except the use of benzylchloride realized, whereas non-existence of an equilibrium between Ib and IIb in the similar reaction condition was observed.

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The phase diagrams of the Ni-Mo- and Ni-W- ternary systems in the region of less than 50mol% were constructed by thermodynamic calculation, based on the data obtained by thermodynamic measurement of the related materials. We found three ternary eutectic points and three or two ternary peritecto-eutectic points as follows:
:L (1365K, 71.mol%Ni-6.0mol%Mo-.mol%)=(Ni)++
:L (1355K, 62.mol%Ni-.mol%Mo-30.mol%)=++
:L (1445K, 42.0mol%Ni-30.6mol%Mo-10.mol%)=(Ni)+NiMo+
P₁:L (1812K, 34.mol%Ni-42.mol%Mo-.mol%)+MoB=+
:L (1633K, 42.mol%Ni-40.4mol%Mo-17.mol%)+Mo=+
:L (1812K, 53.mol%Ni-33.mol%Mo-12.mol%)+Mo=NiMo+
:L (1622K, 51.0mol%Ni-31.6mol%W-17.4mol%)=(Ni)+W+
:L (1260K, 71.0mol%Ni-.0mol%W-.0mol%)=(Ni)++
:L (1291K, 65.4mol%Ni-4.mol%W-29.mol%)=++
P₁:L (2115K, 23.mol%Ni-43.1mol%W-33.1mol%)+WB=+
:L (1657K, 48.mol%Ni-33.1mol%W-18.0mol%)+=W+
The calculated phase diagrams are expected to be useful for the development of new Ni-based heat-, corrosion- or wear-resistance alloys.

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The activities of tobramycin derivatives acetylated and ethylated on the 6'-N, '-N and -N positions were examined. The MICs of these derivatives against tobramycin sensitive strains indicated that '-N-ethylated and 6'-N-ethylated derivatives have a fairly good activity, and confirmed that the -N position is the most important one for antibiotic activity since -N derivatives were less active. The MICs of these derivatives against tobramycin resistant strains, and their inactivation by tobramycin modifying enzymes were examined. These results showed that '-N or 6'-N ethylation protects the drug against inactivation by AAC(') or AAC(6'), respectively, and '-N-ethyltobramycin and 6'-N-ethyltobramycin were active against strains containing these modifying enzymes. On the other hand, -N ethylation protects the drug against inactivation by AAC() but -N-ethyl tobramycin does not inhibit strains containing this enzyme.

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This paper concerns the stability against overturning of the caissons on rubble mound subjected to wave loading. A theoretical discussion is first made of the stability of a leaning caisson during wave loading, as a single degree-of-freedom system. The expression for the lower bound of driving moments sufficient to overturn a given caisson is derived. A review is then made of the damages induced to a composite breakwater, which consisted of two adjoining Stretches and C with slightly different sizes of caissons. Attention is called for the observation that most of the caissons in Stretch were overturned, whereas no caissons in Stretch C were brought into overturning. This fact is examined in detail in the light of the theory of overturning, making it possible to estimate the destructive wave heights that are compatible with the observed patterns of damage in Stretches and C of the composite breakwater.

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The behavior of the soft clay grounds subjected to repeated loading is different from that subjected to sustained loading. The difference in settlement between these two loading patterns should be due to secondary compression over a long period of time. Consequently, soft clay grounds subjected to repeated loading tend to be more compressible than those subjected to sustained loading. Therefore, it is necessary for engineers to predict post-construction settlements under repeated loading. In this respect, the preloading is considered to be promising as a countermeasure to reduce the settlement of clay under repeated loading as well as under sustained loading. The effect of preloading on post-construction consolidation settlement of soft clay subjected to repeated loading after removal of a part of preload is investigated in the present paper. It has become clear that the settlement of a clay sample after preconsolidation is mainly affected by the amount of preload, the degree of consolidation due to the preload, the amount of permanent load and the amount of repeated load after removal of preload. The calculated settlement versus time relations using a method to estimate the amount of consolidation settlement of soft clay grounds subjected to repeated loading after removal of preloading were compared with the observed degree of consolidation as parameters of the intensities of preload and repeated load.

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This study aimed to determine the prevalence of fecal carriage of extended spectrum β-lactamase (ESBL) and/or plasmidic AmpC β-lactamase (pAmpC) producing Escherichia coli among dogs (n=428) in Turkey. Polymerase chain reaction (PCR) and sequencing were used to characterize genes encoding β-lactamase and plasmid mediated quinolone resistance (PMQR). Antimicrobial susceptibility testing and PCRs for virulence genes and phylogenetic groups were also performed. Cefotaxime resistant

. coli isolates were detected in 95 (.%) of the swab samples. Sequencing analysis results showed occurrence of various β-lactamase genes: bla_CTX-M-15 (62), blaTEM-

1b

(42), blaCMY-

2

(

22

), blaCTX-M-

3

(16), bla_CTX-M-1 (15), bla_OXA-1 (

9

) and bla_SHV-12 (

3

) alone or in combination. The most frequently encountered phylogenetic group was group A₁ (35.

8

%), followed by group

D₂

(

22

.1%),

B

1 (15.

8

%), D₁ (

9

.

5

%), A₀ (

7

.4%),

B2₂

(

5

.

3

%) and

B2₃

(4.

2

%), respectively. PMQR genes, aac(6’)-Ib-cr, qnrS1 and qnrB10 were detected in 25.

3

, 10.

5

and 1.1% of the isolates, respectively. While all isolates were susceptible to imipenem and amikacin, resistance rates to non-β-lactam antibiotics ranged from 20.0% for tobramycin to 56.

8

% for tetracycline. The virulence genes were only detected in 34 (36.

2

%) of the isolates and this isolates carried single or various combination of virulence genes of iucD, papC, papE, f17a-A and eaeA. Four isolates were identified as human virulent pandemic CTX-M-15 producing

E

. coli clone O25

b

:ST131/

B

2

. To the best of our knowledge, this is the first study to show fecal carriage of ESBL/pAmpC type β-lactamase producing

E

. coli isolates among dogs in Turkey.

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An analytical measure was developed so that the permanent displacement/deformation caused by seismic subsoil liquefaction can be predicted. Since the effects of topography on displacement is important, a three-dimensional analysis was developed which can fully consider the topography. Moreover, the loss of resistance in the surface unliquefied crust undergoing a tensile stress was taken into account. The empirical interpolation of the lateral displacement along the vertical axis helped reduce the amount of computation. Consequently, a finite-element two-dimensional analysis which is equivalent to a three-dimensional calculation was developed. The displacement obtained by the proposed method is the maximum possible to minimize the potential energy of the subsoil. By comparing the calculated displacement with the observation, the predicted displacement was to some extent greater than the observation. Hence, a dynamic analysis in the time domain, which was also developed by the authors, is necessary for a better matching between prediction and observation. In contrast, the direction of displacement was correctly predicted by the present analysis.

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Two new partially saturated tricyclic ring systems, 6, 6a, , , , 10, 10a, 11-octahydro-11-oxodibenz [, ] oxepins (a and ), and -thiepins (4a and 4) were synthesized. Compounds 4a and 4 were desulfurized to give a pair of isomeric -methylbenzoylcyclohexanes (10a and 10). Deuterated 4a and 4 (11a and 11) were prepared starting from butadiene-d₆ (12). The stereochemical features of a (trans), (cis), 4a (trans) and 4 (cis) are compared with those of 10a, 10, 11a and 11 on the basis of proton nuclear magnetic resonance data.

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During earthquakes, saturated loose sandy soils often liquefy, causing serious damage to buildings and underground structures. Various construction methods have been employed to stabilize these soils against liquefaction. The popular methods are those which increase their density. Vibration and impact methods are commonly employed, but these often pose a problem of noise and vibration in urban areas. Results of previous experiments have shown that Quick Lime Consolidated Briquettes (QCB), a soil stabilizer made of quicklime and cement placed to form cylinders, significantly increases resistance to liquefaction by utilizing the effects of water absorption, swelling, and hardening. In the present study, shaking table tests were performed to evaluate the earthquake resistance of soil treated with QCB. Results of these test showed that the response acceleration and excess pore water pressure in QCB-treated soils were scarcely affected by the excitation of 200 Gals. The soil settlement due to shaking was about one tenth of that for the untreated soil, proving the effectiveness of QCB during earthquakes.

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The possibility of attenuation of microseismic waves due to the presence of an upward folding of the ocean bottom into the liquid is discussed in this paper. The upward folding of the ocean bottom has been idealized by means of an irregularity in the form of a rectangle intruding into the liquid and the evaluation of the displacement component at any point of the solid medium has been carried out in two stages. First, the change in the incident mode of the surface wave due to the presence of the rectangular irregularity has been determined, and second, the subsequent change of the resulting displacement components due to the termination of the liquid layer and the step change in elevation of the solid medium at the continental margin has been discovered. Finally, numerical calculation has been made to determine the attenuation of the microseismic waves of different periods due to the presence of the rectangular irregularity at the ocean bottom.

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This paper introduces a time-dependent radiation damping for the time-domain wave equation analyses of single piles. By deriving the radiation damping ratios of the linear viscoelastic soils along the pile from the dynamic impedance functions (Novak, 1974), time-dependent damping coefficients are obtained from the inverse Fourier Transform of these damping ratios and the static soil spring constants. Numerical examples are studied by solving the wave equations with the finite difference scheme. Applications of the modeling are presented and discussed with emphasis on identifying the primary factors that control the performance of piles. It is important to know that this solution, in contrast to the ordinary frequency-domain approach, can predict the softening load-displacement response of the piles under cyclic loads. The pile response under monotonic loads would be significantly influenced by the proposed damping parameters.

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The paper discusses the main aspects involved in numerical modeling of successive, large deformation, rigid body impacts in sand. The modeling was performed for the study of dynamic compaction of dry sand induced by repeated drops of a rigid tamper. Two dynamic finite element codes were used with a variety of soil models and computational algorithms. Large deformation effects and associated plastic behavior of the sand required special computational techniques of remeshing and reassignment of material properties. Consistency and stability of the formulations were evaluated based on their characteristics of convergency, accuracy, and computational efficiency. The adequacy of these models to represent actual soil behavior was evaluated by comparing computed results with available experimental data from an extensive laboratory investigation. The conclusions presented may serve as general guidelines relevant for this type of analysis.

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