Threshold assessment

Moore, A. J. and Moore, P. J. (1988). Female strategy during mate choice threshold assessment. Evolution 42 387-391. 

The application of sewage sludge increased the contents in the soils in the mean and extreme values by a factor of 5 to 10. The average values for benzo-(a)-pyrene were found to be about 0,2 and for the other polycyclic compounds, 0,03 to 0,3 mg/kg. In comparison to the Dutch reference values, they were closer to the reference values (0,05 or 1,0) than to the test requirement (1 or 20). No critical situation is apparent, with the reservation that the threshold assessment variables are provisional. 

The growing availability of AutoCapture capabilities, first introduced in Europe by St. Jude Medical in their Microny family of single-chamber rate-modulated pacemakers has been expanded to the ventricular channel in the Affinity family of dual-chamber pacemakers (50-52). Similar but not identical algorithms have now been introduced by other manufacturers thus reducing the need for periodic capture threshold assessments. However, it does not totally eliminate the need to consider the combined concerns of patient safety and device longevity and periodically assess the event counter diagnostics that accompany this feature. While AutoCapture will protect the patient to... 

Screening undertaken to decide which projects should be subjecHo environmental assessment. Screening may be partly determined by local EIA regulations. Criteria used include threshold, size of project, and sensitivity of the environment. 

A relatively new methodology caEed aroma dEution analysis (ada), which combines aroma dEution and gas chromatography-olfactometry to gain a better understanding of the relative importance of aroma compounds, was recently done for coffee. In a roasted Colombian coffee brew, 41 impact compounds were found with flavor dEution threshold factors (FD) greater than 25, and 26 compounds had FD factors of 100 or above. WhEe the technique permits assessment of the impact of individual compounds, it does not evaluate synergistic effects among compounds (13). 

The value of the eorrelation eoeffieient using the least squares teehnique and the use of goodness-of-fit tests (in the non-linear domain) together probably provide the means to determine whieh distribution is the most appropriate (Keeeeioglu, 1991). However, a more intuitive assessment about the nature of the data must also be made when seleeting the eorreet type of distribution, for example when there is likely to be a zero threshold. 

None of the foregoing methods will tell the frequency or duration of exposure of any receptor to irritant or odorous gases when each such exposure may exceed the irritation or odor response threshold for only minutes or seconds. The only way that such an exposure can be measured instrumentally is by an essentially continuous monitoring instrument, the record from which will yield not only this kind of information but also all the information required to assess hourly, daUy, monthly, and annual phenomena. Continuous monitoring techniques may be used at a particular location or involve remote sensing techniques. 

A railroad tank car has derailed and overturned, and some material is leaking out and apparently evaporating. The car is labeled "Toxic." In order to take appropriate emergency action, which meteorological factors would you consider and how would you assess them In addition to air pollutants, what meteorological factor has a profound effect on decreasing visibility, and what is the approximate threshold of its influence ... 

The notification dossier may also contain a risk assessment prepared by the notifier. The precise contents of a notification will depend on, e.g., the quantity of the substance to be placed on the market and, to an extent, on the properties and uses of the substance. The thresholds for notification and a summary of the information requirements are given in Table 14.12. 

The links between levels of exposure and inconvenience caused by ventilation noise are described in an investigation carried out on office workers.- Technical measurements and analyses of the ventilation noise at 155 typical office workplaces were in this study combined with assessments by the office workers of the level of disturbance that they experienced, the effect on working performance, fatigue, stress-related pain, and headaches. The average noise level was about 40 dB(A) at two of the workplaces, while it was about 35 dB(A) at two others. It emerged from rhe narrow-band analyses that the sound pressure levels of rhe infrasound were not in any event of an order that this type of sound frequencies (below 20 Hz) could contribute to any disturbance effects. Any steps taken to counter the sound frequencies of the ventilation noise under 50 Hz, i.e., the point of btersection between the threshold curve of auditory perception and the spectral level distribution curve of... 

Threshold Limit Value Ceiling (TLV-C) The concentration that RDA should not be e, cceded during any part of the working e. posure. If conventional industrial hygiene instantaneous monitoring is not feasible, then the TLV-C can be assessed by sampling over a 15-minute period except for those substances that may cause immediate irritation when exposures arc short. 

Figure 3.6-1 shows the electrochemical window of a 76-24 mol % [BMMIM][(GF3S02)2N]/Li[(GF3S02)2N] ionic liquid at both GG and Pt working electrodes [15]. For the purposes of assessing the electrochemical window, the current threshold for both the anodic and cathodic limits was set at an absolute value of 100 pA cm . ... 

Apart from the use of this approach to study the ecotoxicology of neurotoxic pollutants in the field, it also has potential for use during the course of environmental risk assessment. An understanding of the relationship between biomarker responses to neurotoxic compounds and effects at the population level can be gained from both field studies and the use of mesocosms and other model systems. From these it may be possible to define critical thresholds in biomarker responses of indicator species above which population effects begin to appear. In the longer term, this approach... 

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