Individual Thresholds (individual + threshold)

Distribution by Scientific Domains


Selected Abstracts


Determination of Carbonation Threshold in Yogurt

JOURNAL OF FOOD SCIENCE, Issue 1 2003
A.O. Wright
ABSTRACT: Carbonated Swiss-style yogurt ranging between 62 and 1596 ppm CO2 was evaluated for sensory detection of carbonation by 12 college-aged students. Seventy-two repetitions were completed. Each panelist received 42 3-AFC presentations. The group mean threshold was calculated as per American Society for Testing and Materials (ASTM) Method: E1432,91 (1997). Individual thresholds ranged from 181 to 390 ppm. The group mean threshold was determined to be 263 ppm. Upper and lower confidence levels (95%) for the mean were 305 and 227 ppm, respectively. This information may help industry set carbonation levels in carbonated yogurt. [source]


Biological foundation for periodontitis as a potential risk factor for atherosclerosis

JOURNAL OF PERIODONTAL RESEARCH, Issue 1 2005
Yong-Hee P. Chun
Objectives:, Links between periodontal diseases and systemic diseases have been well documented by epidemiological studies. Recently, research has shifted to elucidating the biologic mechanism for a causal relationship. One focus of interest is atherosclerosis, the underlying event of cardiovascular diseases due to its serious health impact. However, it is still not clear whether periodontopathic pathogens are truly etiologic agents or ubiquitous bystanders. This article reviews the current understanding about the molecular biological interactions between periodontal disease and atherosclerosis and the biological plausibility of periodontitis as a potential risk factor for cardiovascular disease. Materials and methods:, The current literature regarding periodontal diseases and atherosclerosis and coronary vascular disease was searched using the Medline and PubMed databases. Results:,In vitro experiments and animal models are appropriate tools to investigate the biological interactions between periodontal disease and atherosclerosis at the cell molecular level. The concepts linking both pathologies refer to inflammatory response, immune responses, and hemostasis. In particular, Porphyromonas gingivalis appears to have unique, versatile pathogenic properties. Whether or not these findings from isolated cells or animal models are applicable in humans with genetic and environmental variations is yet to be determined. Likewise, the benefit from periodontal therapy on the development of atherosclerosis is unclear. Approaches targeting inflammatory and immune responses of periodontitis and atherosclerosis simultaneously are very intriguing. Conclusion:, An emerging concept suggests that a pathogenic burden from different sources might overcome an individual threshold culminating in clinical sequela. P. gingivalis contributes directly and indirectly to atherosclerosis. [source]


A SIMPLE ALTERNATIVE ANALYSIS FOR THRESHOLD DATA DETERMINED BY ASCENDING FORCED-CHOICE METHODS OF LIMITS

JOURNAL OF SENSORY STUDIES, Issue 3 2010
HARRY T. LAWLESS
ABSTRACT An alternative analysis of forced-choice threshold data sets such as the type generated by ASTM method E-679 involves a simple interpolation of chance-corrected 50% detection. This analysis has several potential advantages. The analysis does not require the ad hoc heuristics for estimating individual thresholds above and below the series. It takes into account the possibility of guessing correctly, which is not considered in the ASTM calculations and produces a downward bias to the estimates. It does not discount correct responses early in the series which may be legitimate detections, but which are discounted by the ASTM method if followed by any incorrect response. Comparisons of the two methods in a large consumer study of odor detection threshold study data set gave comparable values. The interpolation can also be done to determine other levels of detection (e.g. 10, 25%). These values other than 50% can be potentially useful in setting regulatory standards for water or air pollution limits or to food manufacturers who wish to avoid detection of taints by more sensitive individuals. PRACTICAL APPLICATIONS The forced choice methods for threshold estimation have proven practically useful in comparing the potency of various flavor materials and in comparing the sensitivities of individuals. The ASTM method E-679 is one such method. The alternative analysis of results from this procedure which is outlined here provides additional information and does not exhibit the downward bias because of correct guessing. [source]


Development of a computerized assessment for visual masking

INTERNATIONAL JOURNAL OF METHODS IN PSYCHIATRIC RESEARCH, Issue 2 2002
Michael Foster Green
Abstract Visual masking provides a highly informative means of assessing the earliest stages of visual processing. This procedure is frequently used in psychopathology research, most commonly in the study of schizophrenia. Deficits in visual masking tasks appear to reflect vulnerability factors in schizophrenia, as opposed to the symptoms of the illness. Visual masking procedures are typically conducted on a tachistoscope, which limits standardization across sites, as well as the number of variables that can be examined in a testing session. Although visual masking can be administered on a computer, most methods used so far have had poor temporal resolution and yielded a limited range of variables. We describe the development of a computerized visual masking battery. This battery includes a staircase procedure to establish an individual's threshold for target detection, and a relatively dense sampling of masking intervals. It includes both forward and backward masking trials for three different masking conditions that have been used previously in experimental psychopathology (target location, target identification with high-energy mask, and target identification with low-energy mask). Copyright 2002 Whurr Publishers Ltd. [source]