Design of A/D converters with hierarchic networks

A methodology for designing analog to digital (A/D) converters based on a hierarchic network is explored. The principle of this methodology and design procedure are presented. The characteristics and performances of the converter are compared with the converter based on the Hopfield network. Two circuit models for the A/D converters are described in this paper. As a hierarchic network is used, the A/D converters designed have no local minima in their operation, With the method proposed in the paper, high bit number A/D converters can be easily designed, and the converters designed are fast in signal conversion and stable in operation     

BiCMOS circuit optimisation technique linking channel width of MOSdevice to collector design of BJT

A methodology to optimise the propagation delay of BICMOS/BiNMOS circuits for high level injection is proposed. It is based on modifying the collector design of the BJT in association with an increase in the channel width of the MOS device to account for the speed degradation caused by the onset of high level injection. A sensitivity-type approach has been adopted to link the value of the channel width of the MOS device to the collector profile of the BJT     

The effects of selenium supplementation on antioxidative enzyme activities and plasma and erythrocyte selenium levels

Nucleotide pyrophosphatase (EC 3.6.1.9) is a membrane enzyme purified from a number of mammalian sources that may have alkaline phosphodiesterase I (EC 3.1.4.1) activity as well. The mol. wt and subunit structure of this membrane glycoprotein are similar to that of the murine plasma cell alloantigen, PC-1. The PC-1 protein is a disulfide-bonded dimer of identical 115 kDa polypeptides that is selectively expressed on B lineage cells that have reached the degree of maturation associated with immunoglobulin secretion. It also has restricted expression in certain non-lymphoid tissues. In this report, we show that alkaline phosphodiesterase I activity parallels PC-1 mRNA expression in a number of B lineage cell lines at different stages of differentiation. Furthermore, we demonstrate increases in both nucleotide pyrophosphatase and alkaline phosphodiesterase I enzymatic activities in transiently transfected COS-7 cells expressing a cloned PC-1 cDNA construction. These results extend our previous immunological and correlative studies and directly ascribe an enzymatic activity to this cell surface differentiation antigen. These experiments also demonstrate that a single protein is responsible for both alkaline phosphodiesterase I and nucleotide pyrophosphatase activities.     

A new approach for isolating cell wall mutants in Saccharomyces cerevisiae by screening for hypersensitivity to calcofluor white

To study cell wall assembly, a simple screening method was devised for isolating cell wall mutants. Mutagenized cells were screened for hypersensitivity to Calcofluor White, which interferes with cell wall assembly. The rationale is that Calcofluor White amplifies the effect of cell wall mutations. As a result, the cells stop growing at lower concentrations of Calcofluor White than cells with normal cell wall. In this way, 63 Calcofluor White-hypersensitive (cwh), monogenic mutants were obtained, ordered into 53 complementation groups. The mannose/glucose ratios of the mutant cell walls varied from 0.15 to 3.95, while wild-type cell walls contained about equal amounts of mannose and glucose. This indicates that both low-mannose and low-glucose cell wall mutants had been obtained. Further characterization showed the presence of three low-mannose cell wall mutants with a mnn9-like phenotype, affected, however, in different genes. In addition, four new killer-resistant (kre) mutants were found, which are presumably affected in the synthesis of β1,6-glucan. Most low-glucose cell wall mutants were not killer resistant, indicating that they might be defective in the synthesis of β1,3-glucan. Eleven cwh mutants were found to be hypersensitive to papulacandin B, which is known to interfere with β1,3-glucan synthesis, and four cwh mutants were temperature-sensitive and lysed at the restrictive temperature. Finally, nine cwh mutants were hypersensitive to caffeine, suggesting that these were affected in signal transduction related to cell wall assembly.     

Identification of high-risk groups among node-positive patients with stage IB and IIA cervical carcinoma

1. Mice were given sodium valproate (0.71%) in the drinking fluid for 21 days. The antinociceptive activity, locomotor activity and body temperature changes were recorded at 7, 14 and 21 days. The possible carryover antinociceptive effects were also determined after valproate withdrawal for up to 3 days after 7-, 14- and 21-day treatment. 2. The antinociceptive activity was present only on days 7, 14 and 21 and, on withdrawal of the drug, the antinociceptive activity disappeared. 3. Thus, with this regimen of valproate administration, there was no persistent antinociceptive activity (carryover effect). There were essentially no effects of valproate on the locomotor activity and body temperature of mice. The antinociceptive effects were due to the presence of the drug and disappeared on valproate's withdrawal.     

3D free-form surface registration and object recognition

A new technique to recognise 3D free-form objects via registration is proposed. This technique attempts to register a free-form surface, represented by a set of % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaGOmamaala% aabaGaaGymaaqaaiaaikdaaaGaamiraaaa!38F8!\[2\frac{1}{2}D\] sensed data points, to the model surface, represented by another set of % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaGOmamaala% aabaGaaGymaaqaaiaaikdaaaGaamiraaaa!38F8!\[2\frac{1}{2}D\] model data points, without prior knowledge of correspondence or view points between the two point sets. With an initial assumption that the sensed surface be part of a more complete model surface, the algorithm begins by selecting three dispersed, reliable points on the sensed surface. To find the three corresponding model points, the method uses the principal curvatures and the Darboux frames to restrict the search over the model space. Invariably, many possible model 3-typles will be found. For each hypothesized model 3-tuple, the transformation to match the sensed 3-tuple to the model 3-tuple can be determined. A heuristic search is proposed to single out the optimal transformation in low order time. For realistic object recognition or registration, where the two range images are often extracted from different view points of the model, the earlier assumption that the sensed surface be part of a more complete model surface cannot be relied on. With this, the sensed 3-tuple must be chosen such that the three sensed points lie on the common region visible to both the sensed and model views. We propose an algorithm to select a minimal non-redundant set of 3-tuples such that at least one of the 3-tuples will lie on the overlap. Applying the previous algorithm to each 3-tuple within this set, the optimal transformation can be determined. Experiments using data obtained from a range finder have indicated fast registration for relatively complex test cases. If the optimal registrations between the sensed data (candidate) and each of a set of model data are found, then, for 3D object recognition purposes, the minimal best fit error can be used as the decision rule.     

Neonatal septic arthritis

Neonatal septic arthritis has always been considered as separate from its counterpart in older children. The condition is uncommon but serious. Affected neonates usually survive, but with permanent skeletal deformities. Ten cases of neonatal septic arthritis were diagnosed between January 1989 and December 1993 in the neonatal intensive care units of two referral hospitals in the state of Kelantan, Malaysia. All except one neonate was born prematurely. The mean age of presentation was 15.6 days. Joint swelling (10/10), increased warmth (7/10) and erythema of the overlying skin (7/10) were the common presenting signs. Vague constitutional symptoms preceded the definitive signs of septic arthritis in all cases. The total white cell counts were raised with shift to the left. The knee (60%) was not commonly affected, followed by the hip (13%) and ankle (13%). Three neonates had multiple joint involvement. Coexistence of arthritis with osteomyelitis was observed in seven neonates. The commonest organism isolated was methicillin resistant Staphylococcus aureus (9/10). Needle aspiration was performed in nine neonates and one had incision with drainage. Follow up data was available for five neonates and two of these had skeletal morbidity. Early diagnosis by frequent examination of the joints, prompt treatment and control of nosocomial infection are important for management.     

Basin-type solar distillers with operating pressure reduced for improved performance

The theoretical and empirical equations for designing basin-type solar distillers with operating pressure reduced have been derived from energy and material balances coupled with experimental data. Considerable improvement in productivity was obtained by reducing the operating pressure in the solar distillers.