Positive Response

Correlation of Transformation Response with Reported Carcinogenicity and Mutagenicity 

---

New The continuing positive response to the gen erous use of tables m Organic Chemistry has en couraged us to create new ones The new tables are... 

Table 8 indicates the compatibiUty of magnesium with a variety of chemicals and common substances. Because the presence of even small amounts of impurities in a chemical substance may result in significantly altered performance, a positive response in the table only means that tests under the actual service conditions are warranted (132). Other factors which may significantly alter magnesium compatibiUty include the presence of galvanic couples, variations in operating temperatures, alloy composition, or humidity levels. 

Although in vitro mutagenicity tests suggest that some nitrofurans in general provoke a positive response, use of in vivo mammalian systems has produced equivocal or negative results. 

The contractors SSAHPs at Sites B, F, and K had general confined space provisions but lacked site-specific confined space procedures. For example, SSAHPs for the Site K contractor and subcontractor had written confined space entry programs, but the programs did not establish site-specific rescue procedures or identify the confined space hazards present on the site. The job hazard analyses for both programs failed to address site maintenance tasks that could involve confined space entry and hot work hazards. The programs also failed to identify the specific person or position responsible for supervising confined space entry procedures and the location of permit-required confined spaces on site. Interviews with both contractors indicated confusion about rescue procedures. 

Chemicals can be deleted if tlicrc is not sufficient evidence to establish positive responses to any of these questions. 

This is one of the most important factors in alleviating microbial problems. A decrease in microbial activity after treatment indicates a positive response to the microbiocidal treatment. Continuous monitoring is imperative for effective control. 

Does HCN actually exist in Odontosyllis enopla as an activator of luminescence Its existence appears likely based on the following two observations. (1) Using benzidine-copper acetate reagent (Feigl, 1960), a faint positive response of HCN was obtained from... 

Clinical trials should be designed so as to mirtimise potential sources of bias. It is known that patients can demonstrate a positive response to treatments that they believe will benefit them, even if no pharmaceutical agent has been admrrtistered (the placebo effect ). Similarly, investigators may be biased in their observations by an expectation of particular results. To avoid such bias, blinded trial designs are used. 

In the case of multi-centre, multi-state trials a single opinion should be delivered from each Member State. Only vhen a positive response has been obtained from an Ethics Committee and a Competent Authority can a trial commence. 

Would there be a positive response amongst the mentee target group ... 

Results of methyl parathion assays involving effects on chromosomes have also been contradictory. For sister chromatid exchange, Waters et al. (1982) reported a positive response in Chinese hamster ovary cells only in the presence of metabolic activation system, while methyl parathion tested positive without a metabolic activation system in Chinese hamster V79 cells (Chen et al. 1981), cultured normal human lymphoid cells (Chen et al. 1981 Gomez-Arroyo et al. 1987 Sobti et al. 1982), and Burkitt s l5miphoma cells (Chen et al. 1981). Chen et al. (1981) found a significant dose-related increase in sister chromatid exchange in both hamster and human cultured cells, but dose-related cell cycle delays were less pronounced in human cell lines than in V79 cells. Negative results were obtained for chromosomal aberrations in human lymphocytes without a metabolic activation system (Kumar et al. 1993). 

Acnegenic Response. Both 2,3,7,8-TCDD and HCDD produced chloracne in the rabbit ear bioassay as indicated by the formation of comedones. Solutions of 2,3,7,8-TCDD (sample c) in benzene ranging in concentration from 0.04 /xg/ml to 400 ju,g/ml produced a positive response with severity increasing with concentration. A negative response was obtained with a solution of 0.004 ju,g/ml. In contrast, a chloroform solution of 1,2,3,4-TCDD, 50 jug/ml, did not produce a positive response. With HCDD (samples a, b, c, and d), a response was produced by solutions of 10 to 50 ju,g/ml in chloroform and dimethoxyethane. Chloroform extracts from 10% suspensions of 2,7-DCDD or OCDD were negative, indicating that these have a low order or possibly no acnegenic activity. 

Elsevier Science and I, as Editor of the series, hope that these handbooks will receive a positive response from the sensor and actuator community and we expect that the series will be of great use to the many scientists and engineers working in this exciting field. 

O The goals of therapy for GAD are to acutely reduce the severity and duration of anxiety symptoms and restore overall functioning. The long-term goal in GAD is to achieve and maintain remission. With a positive response to treatment, patients with GAD and comorbid depression should have minimal depressive symptoms. 

This procedure was compared with sequential extractive techniques employing alkaline hydrolysis of dried plant tissue followed by extraction of the acidified mixture with ethyl acetate. Fractions were individually evaluated for phytotoxic properties. Selected fractions from those showing a positive response were analyzed by gas-liquid chromatography. Structural identification and characterization of the individual components in these selected fractions were accomplished by gas chromatography-mass spectrometry. 

The Log-Probit Model. The log-probit model has been utilized widely in the risk assessment literature, although it has no physiological justification. It was first proposed by Mantel and Bryan, and has been found to provide a good fit with a considerable amount of empirical data (10). The model rests on the assumption that the susceptibility of a population or organisms to a carcinogen has a lognormal distribution with respect to dose, i.e., the logarithm of the dose will produce a positive response if normally distributed. The functional form of the model is ... 

PPR is the probability of obtaining positive responses, TPR true positive rate (Eq. 4.48), TNR true negative rate (Eq. 4.49), FPR false positive rate (Eq. 4.50), FNR false negative rate (Eq. 4.51), X/ and xu are the lower and upper limits of the unreliability region... 

The solids circulation patterns were investigated with a force probe developed in-house. Typical force probe responses are presented in Figs. 43 and 44 for a probe located at 0.13 m from the jet nozzle and with different penetrations into the bed for an air tube velocity of 45.7 m/s. Sincetheforce probe is directional, the upward solids movement will produce a positive response from the probe and vice versa, the magnitude of the response being an indication of the magnitude of solids circulation rate. The number of major peaks per unit time is closely related to the actual bubble frequency in the bed. 

Figures 3.8(a) and (b) show the linear sweep voltammograms and concomitant reflectivity changes monitored at 2.34pm (4273cm-1) and 1.93pm (5181cm-1), Under the conditions employed the reflectivity change was obtained as (l/R)(AR/d ). This gives spectra in which an increase in reflectivity results in a negative value of (l/R)-(AR/d ) and a decrease in reflectivity (i.e, absorption) gives a positive response.

The situation is further complicated by the finding that in negative phototaxis, radiation between 500 and 560 nm and above 700 nm is effective in addition to the wavelengths, which are active in the positive response. Nultsch et al.106) have discus-... 

The main advantage of this technique is the rapidity of response and the possibility of performing many bioassays with different algal strains at the same time. The disadvantage is that the kind of response is qualitative. This limitation can be overcome by selecting for liquid inhibition bioassays, the strains that give a positive response in paper disk bioassay (i.e. the strains sensitive to the allechemical(s) tested). 

---