Factors influencing deterioration of denitrification by oxygen entering an anoxic reactor through the surface

The purpose of the paper is to examine the factors that influence the deterioration of denitrification in open anoxic reactors. For this investigation an ASM 1-based simulation model was developed and successfully applied to fit data from batch experiments carried out in lab-scale reactor vessels (uncovered and covered) using both clarified domestic wastewater and synthetic wastewater. Applying the verified model, simulation studies were performed to investigate the effects of available denitrifiable substrate, biomass concentration, oxygen transfer rate, and temperature on deterioration of denitrification in open anoxic reactors. It has been shown that oxygen entering an anoxic reactor through the surface may not just affect denitrification metabolically, but also kinetically, due to increased dissolved oxygen (DO) concentration exerting an inhibitory effect on the denitrification rate. When the exogenous substrate concentration in the reactor vessel is high enough for a high consumption rate, the DO concentration is kept low. The higher the biomass concentration, and thereby the consumption rate of endogenous substrate, the lower the DO concentration during the low-rate denitrification phase. At low substrate removal rates, decreasing temperature will cause the DO concentration in anoxic vessels to increase. The results suggest that assuring removal of available exogenous carbon source at high rate by staging of open anoxic bioreactors may significantly improve denitrification efficiency.     

Behavioral instrumental reactions and the frequency of cardiac contractions in chimpanzees with different rates of approaching a goal and a shortened time of its exposure

Reaching the goals moving with different speed (from 1 to 400 mm/sec), the chimpanzee revealed respective behavioural, emotional, instrumental, and cardiovascular responses. When obscuring the goal for a certain time, the chimpanzee nevertheless managed to reach it, the relations between the speed of approaching goal and behavioural or instrumental responses being preserved. Thereupon, the chimpanzee are able to reach the goal provided the latter's trace exceeds 5-10-fold the time of really acting stimulus.     

The delta 5-3 beta-hydroxy steroid acyl transferase activities in tissues of the male rat and sheep

The present study reports on the results of a follow-up examination of patient material, 5 years after the installation of the fixed supraconstruction. The patient group comprised 11 individuals. Briefly, a split-mouth technique of treatment was used. In the right side of the mandible the traditional 2-step surgical approach for implant installation was used. In the left jaw quadrant a 1-step surgical procedure was used. A clinical and radiographical examination was performed 5 years after the initial connection of the supraconstruction to the implants. At the 5-year follow-up examination all 61 implants examined at the 18-month follow-up were still in service and found to be clinically stable irrespective of the surgical procedure used. Furthermore, the results of the present clinical and radiographical follow-up study demonstrate that the marginal bone level at implants placed anteriorly in the edentulous mandible and supporting fixed supraconstructions is stable between 18 and 60 months irrespective of whether placed according to a 1-step or 2-step surgical procedure.     

The six N-linked carbohydrates of the lutropin/choriogonadotropin receptor are not absolutely required for correct folding, cell surface expression, hormone binding, or signal transduction

Using two separate methods, we have determined that all six potential sites for N-linked glycosylation on the rat lutropin/choriogonadotropin receptor (rLHR) contain carbohydrates. The functional roles of the carbohydrates were analyzed initially through the use of two nonglycosylated receptor mutants rLHR(N(77,152,173,269,277,291)Q) and rLHR(N(77,152,269,277,291)Q;T(175)A). Although Western blot analyses demonstrated both mutant receptors to be stably expressed, little or no hCG binding activity could be detected in detergent solubilized extracts of 293 cells expressing either nonglycosylated LHR mutant. Although this loss of hCG binding was concluded to be due to misfolding, it was unknown whether this misfolding was due to the absence of carbohydrates or to the multiple amino acid substitutions that had been introduced into the polypeptide. To differentiate between these possibilities, hCG binding assays were performed with nonglycosylated receptors obtained after tunicamycin treatment of cells expressing the wild-type rLHR. Even though these wild-type receptors were confirmed to be devoid of all N-linked carbohydrates by Western blots, they were found to bind hCG with a normal high affinity. In addition, tunicamycin-derived, nonglycosylated LHRs were present at the cell surface and exhibited a phenotype consistent with mature receptors due to their capability to mediate hCG-stimulated cAMP production as well as bind oLH with high affinity. These results indicate that the loss of high affinity hormone binding by rLHR(N(77,152,173,269,277,291)Q) and rLHR(N(77,152,269,277,291)Q;T(175)A) is simply due to the collective amino acid substitutions rather than to the absence of carbohydrates. Therefore, N-linked carbohydrates are not absolutely required for the proper folding of the rLHR into a mature receptor capable of binding hormone and signaling. These results are in marked contrast to the follitropin receptor (FSHR), a very similar receptor which has been shown to strictly require N-linked carbohydrates for folding of the nascent protein.     

Massive hemorrhage caused by a perforating Gianturco-Z stent resulting in an aortoesophageal fistula

Squamous cell carcinoma of the tonsil has a relatively poor prognosis. Aggressive surgery, radiation therapy and combinations of irradiation and surgery have been employed but there exists some controversy about the efficacy of these treatment modalities. The purpose of this paper is to compare the efficacy of treatment between the surgery followed by radiation therapy and the preoperative radiation therapy followed by surgical resection. The medical records of 33 patients treated for squamous cell carcinoma of the tonsil at the Department of Otolaryngology-Head and Neck Surgery, Korea University Hospital between 1989-1993 were reviewed retrospectively. None of the patients were stage I, but stage II, III, and IV were four, five, and 24 patients, respectively. There were 30 males and three females. The most common histopathology was moderately differentiated squamous cell carcinoma (20/33). The 13 patients treated initially with surgery had an overall three-year survival rate of 38.5%, and the rate for the 20 patients treated initially with radiation was 40%. The main pattern of treatment failure was a local recurrence and neck metastases, and pathologic differentiation thought to be an important prognostic factor. Complications are fewer in patients treated initially with surgery (23.1%) than patients initially treated with radiation (50.0%). There is no difference in the efficacy between the two therapeutic groups.     

Electron tomography of large, multicomponent biological structures

Genome-wide scans for linkage of chromosome regions to type 1 diabetes in affected sib pair families have revealed that the major susceptibility locus resides within the major histocompatibility complex (MHC) on chromosome 6p21 (lambda s = 2.5). It is recognised that the MHC contains multiple susceptibility loci (referred to collectively as IDDM1), including the class II antigen receptor genes, which control the major pathological feature of the disease: T lymphocyte-mediated autoimmune destruction of the insulin-producing pancreatic beta cells. However, the MHC genes, and a second locus, the insulin gene minisatellite on chromosome 11p15 (IDDM2; lambda s = 1.25), cannot account for all of the observed clustering of disease in families (lambda s = 15), and the scans suggested the presence of other susceptibility loci scattered throughout the genome. There are four additional loci for which there is currently sufficient evidence from linkage and association studies to justify fine mapping experiments: IDDM4 (FGF3/11q13), IDDM5 (ESR/6q22), IDDM8 (D6S281/6q27) and IDDM12 (CTLA-4/2q33), IDDM4, 5 and 8 were detected by genome scanning, and IDDM12 by a candidate gene strategy. The results suggest that the clustering of type 1 diabetes in families is due to the sharing of alleles at multiple loci, and that the as yet unidentified environmental factors are not causing clustering, but instead appear to influence the overall penetrance of genetically programmed susceptibility. The data are consistent with a polygenic threshold model for the inheritance of type 1 diabetes.     

Hybrid identification of nuclear power plant transients with artificial neural networks

Proper and rapid identification of malfunctions (transients) is of premier importance for the safe operation of nuclear power plants. Feedforward neural networks trained with the backpropagation (BP) algorithm are frequently applied to model simulated nuclear power plant malfunctions. The correct identification of unlabeled transients-or transients of the "don't-know" type have proven to be especially challenging. A novel hybrid neural network methodology is presented which also correctly classifies the unlabeled transients. From this analysis the importance for properly accommodating practical aspects such as the drift of electronics elements of a simulator, the digitization of simulated and actual plant signals, and the accumulating errors during numerical integration became obvious. Beside the feedforward neural networks trained with the BP algorithm, many other types of networks and codes were used for finding the best (sensitive and robust) algorithms. Various neural network based models were successfully applied to identify labeled and unlabeled malfunctions of the Hungarian Paks nuclear power plant simulator. The BP and probabilistic methods have been proven as the most robust against the misleading recognition of unlabeled malfunctions.