Hot surface ignition system

A hot-surface ignition (HSI) system that controls the operation of industrial gas-fired appliances with levels of safety, reliability, and versatility never before achieved is presented. A microcomputer-based control module provides multilevel component fault tolerance in critical areas such as the flame-sensing and valve-control circuits. The program in the control module negates unsafe operation in the event of a failure of the microcomputer by requiring diverse signals to exist at precise time relationships to execute particular functions. The control module is designed for reliable operation far beyond normal appliance life     

In vitro cultivation of Trypanosoma acomys: production of insect stages and bloodstream forms

When Trypanosoma acomys bloodstream forms were cultivated at 37 degrees C in Schneider's Drosophila medium supplemented with 20% (v/v) heat-inactivated foetal calf serum (FCS), with Microtus agrestis embryonic fibroblasts in RPMI 1640 medium supplemented with 20% FCS or in Baltz's medium supplemented with 10% FCS, the parasites transformed and largely remained as epimastigotes. Epimastigotes were also usually the commonest stage observed when the parasites were co-cultivated with a mosquito cell line at 27 degrees C. However, if these cultures were initiated with the supernatant suspensions from fibroblast cultures that had been cryopreserved, trypomastigotes, including bloodstream-like forms, were the predominant stage for the first 4 days of culture. It is suggested that the glycerol supplement or the temperature changes stimulated this unusual morphogenesis. At 27 degrees C, T. acomys was incapable of multiplying and died when cultured in fresh Schneider's Drosophila medium supplemented with 20% FCS, but co-cultivation with the mosquito cell lines or cultivation in cell-free supernatants from 1-week-old mosquito cell cultures was successful at this temperature; most of the parasites multiplied as epimastigotes.     

Immunoassay of human Neisseria meningitidis serogroup A antibody

An enzyme immunoassay is described which quantitates antibodies to Neisseria meningitidis serogroup A capsular polysaccharide in human sera. Modifications of a previously developed two-day assay by Carlone et al. were made to permit analysis in one day and to be compatible with automation. The allowable variations in assay conditions and the areas in which stringent control must be maintained for consistent assay performance are described. Antigen-coating parameters, the kinetics of primary and secondary antibody incubation steps, the buffer compositions, including detergents, serum requirements, and the need for blocking steps were examined. Our modified one-day assay showed excellent agreement with the standardized method of Carlone, with a correlation coefficient between the two methods of 0.989. This assay is adaptable within a permissible range of parameters thus facilitating the implementation of the standardized assay. This will maximize the consistency of results from serum analysis for conjugate vaccine trials related to serotype A Neisseria meningitidis.     

Memory monitoring by animals and humans

The authors asked whether animals and humans would use similarly an uncertain response to escape indeterminate memories. Monkeys and humans performed serial probe recognition tasks that produced differential memory difficulty across serial positions (e.g., primacy and recency effects). Participants were given an escape option that let them avoid any trials they wished and receive a hint to the trial's answer. Across species, across tasks, and even across conspecifics with sharper or duller memories, monkeys and humans used the escape option selectively when more indeterminate memory traces were probed. Their pattern of escaping always mirrored the pattern of their primary memory performance across serial positions. Signal-detection analyses confirm the similarity of the animals' and humans' performances. Optimality analyses assess their efficiency. Several aspects of monkeys' performance suggest the cognitive sophistication of their decisions to escape.     

Transgenic pigs expressing human CD59 and decay-accelerating factor produce an intrinsic barrier to complement-mediated damage

OBJECTIVE: The antenatal and intrapartum management of women with autoimmune thrombocytopenia is controversial. The current approach emphasizes an effort to identify maternal characteristics predictive of severe neonatal thrombocytopenia or to measure fetal platelet counts and perform cesarean section in patients considered to be at risk for neonatal intracranial hemorrhage. In the current study we review our experience with maternal autoimmune thrombocytopenia and neonatal outcome. STUDY DESIGN: Fifty-five pregnancies with autoimmune thrombocytopenia over a 10-year period in three major medical centers in San Diego, California, were evaluated. Maternal characteristics and neonatal outcomes were assessed and compared with those in other recent reports. Data were submitted to Fisher's exact (two-tailed), chi2, and Student t tests, with linear regression performed to analyze the association between variables. RESULTS: Maternal characteristics including platelet count, presence of antiplatelet antibody, antecedent history of autoimmune thrombocytopenia, and corticosteroid therapy were not predictive of severe neonatal thrombocytopenia. Maternal history of splenectomy was significantly correlated with fetal platelet counts <50 x 10(9)/L (odds ratio 5.63; 95% confidence interval 2.2 to 14.3). There were four neonates with severe neonatal thrombocytopenia (8%), and one who was delivered by cesarean section had intracranial hemorrhage. CONCLUSIONS: These findings, combined with others in the literature, confirm that severe neonatal thrombocytopenia is an infrequent complication of maternal autoimmune thrombocytopenia and is not reliably predicted by maternal characteristics. Intracranial hemorrhage is also a rare event and is not related to mode of delivery. Cesarean section should be reserved for obstetric indications only.     

Reaction force control of a linear electrical generator for direct drive wave energy conversion

Direct drive wave energy converters have been proposed in view of the disadvantage of mechanical complexity and low conversion efficiencies in conventional wave energy converters. By directly coupling a linear generator to a reciprocating wave energy device, it is suggested that direct drive power take-off could be a viable alternative to hydraulic- and pneumatic-based systems. To further realise the benefits of a direct drive system, a control scheme based on reaction force control to maximise energy extraction is presented. It focuses predominantly on the theoretical analysis of the linear generator reaction force. The modelling, simulation and control of direct drive wave energy conversion are systematically investigated by computer-aided analysis via Matlab/Simulink     

Angiogenesis during tumor progression in the oral cavity is related to reduced apoptosis and high tumor cell proliferation

To evaluate the potential of [1-(11)C]-3-(R,S)-methyloctanoate (BMOA), [1-(11)C]-2-octynoate, and [1-(11)C]-2-decynoate as PET tracers for studying particular steps in fatty acid beta-oxidation, we examined the pharmacokinetics of these compounds in rats and a cat. In rats given these compounds, high levels of radioactivity accumulated in the heart, liver, and kidneys, suggesting their potential as tracers for studying beta-oxidation in these tissues. These organs were clearly visible with PET in a cat given BMOA, indicating the utility of BMOA for imaging these organs.     

Human RanBP3, a group of nuclear RanGTP binding proteins

Willingness to pay (WTP) for a health care program can be estimated in contingent valuation (CV) studies by a nonparametric approach. The nonparametric approach is free from distributional assumptions, which is a strength compared with parametric regression-based approaches. However, using a nonparametric approach it is not clear how to obtain confidence statements for WTP estimates, for example, when testing hypotheses regarding differences in mean WTP for different subsamples. The authors propose a procedure that allows statistical testing and confidence interval estimation by employing bootstrap techniques. The method is easy to implement and has low computational costs with modern personal computers. The method is applied to data from a CV study where the WTP for hormone replacement therapy was investigated. The mean WTP was estimated for the full sample and separately for women with mild and severe menopausal symptoms. Using the proposed method, the mean WTP was significantly higher in the group with severe symptoms.