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Sensitive Individuals (sensitive + individual)
Selected AbstractsGenetic indicators of herbicide stress in the pacific oyster Crassostrea gigas under experimental conditionsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2000Dario Moraga Abstract This study examined use of the oyster Crassostrea gigas as a bioindicator of experimental pollution caused by two concentrations of five pesticides (atrazine, isoproturon, alachlore, metolachlore, and diuron) used in agricultural and urban activities. The effect of these pesticides on the genetic structure of the marine bivalve was studied as part of an environmental biomonitoring project. This research was performed on two natural estuarine populations sampled along the French Atlantic coast as part of an ongoing monitoring program to survey the ecosystem of Brittany using two approaches: identifying the genetic markers based on the alleles and genotypes associated with pollution effects, and searching for a correlation between these markers and the sensitivity or tolerance of individuals under stress conditions. Results indicate a differential survival of individuals subjected to the various pollutants examined. The sensitivity of alleles and genotypes to environmental stress can be assessed based on the significant differences in allele and genotype frequencies observed between resistant and sensitive individuals when subjected to the pesticides. This genetic study included examination of five enzyme systems (Ak, Pgi, Cap, Pgm, and Mdh) involved in physiologic processes. A total of six alleles and five genotypes at three loci (Ak, Pgi, and Pgm) were identified as being markers of resistance or sensitivity. It is hypothesized that these markers could be used as potential genetic markers in estuarine ecosystem monitoring. [source] A SIMPLE ALTERNATIVE ANALYSIS FOR THRESHOLD DATA DETERMINED BY ASCENDING FORCED-CHOICE METHODS OF LIMITSJOURNAL OF SENSORY STUDIES, Issue 3 2010HARRY 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] The Genetics of Acute Functional Tolerance and Initial Sensitivity to Ethanol for an Ataxia Test in the LSxSS RI StrainsALCOHOLISM, Issue 5 2000Vaughn M. Gehle Background: It has been proposed that development of tolerance to the behavioral effects of ethanol depends on the degree of impairment produced by the drug; that is, more sensitive individuals should develop greater tolerance. Tests of this hypothesis with respect to acute functional tolerance have produced contradictory results. We tested the hypothesis by examining the genetic relationship between initial sensitivity and acute functional tolerance in the LSXSS recombinant inbred mice. Methods: We tested mice for initial sensitivity to the ataxic effects of 1.75 g/kg of ethanol in a stationary dowel balance test by determining blood and brain ethanol concentrations at fall. Acute tolerance to the ataxic effects of ethanol was determined by measuring blood ethanol concentration (BEC) at regain of dowel balance ability after the first injection (BEC1RB) and after a second ethanol injection of 2.0 g/kg (BEC2RB). Acute tolerance was quantified by the difference in ethanol concentration at the two regains of balance (BEC2RB , BEC1RB) or by the difference between the second regain and one of the initial sensitivity measures (BEC2RB , initial sensitivity). Results: Four different measures of initial sensitivity were taken: two that used BEC values and two that used forebrain or hindbrain ethanol concentrations. We calculated acute tolerance values by using each of these initial sensitivity measures plus BEC2RB. No evidence of a genetic relationship between initial sensitivity and acute tolerance was found, which suggests that these are two independent phenomena with respect to stationary dowel balance. Conclusions: Three conclusions can be drawn from this work: (1) Orbital sinus BEC at early time points (<5 min postinjection) may or may not accurately reflect brain EC in mice, dependent on genotype; (2) there is no genetic relationship between initial sensitivity and acute tolerance to stationary dowel ataxia in the LSXSS RIs; and (3) sex-specific factors affect low-dose ethanol responses on the stationary dowel. [source] Determination of the Minimal Erythema Dose and Colorimetric Measurements as Indicators of Skin Sensitivity to UV-B Radiation,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 6 2004Sérgio Dornelles ABSTRACT There is a strong relation between chronic UV-B-induced sunburns and the development of skin cancer. Therefore, it is important to obtain a method that can be reproduced easily to detect individuals with similar skin color but different sensitiveness to sun exposure. The study evaluated 193 healthy volunteers (68% women; the average age was 38 years). They were divided into six groups of at least 30 subjects, according to skin type. The minimal erythema dose (MED) was assessed in two non-sun-exposed areas (thorax-infra-axillary area and on the buttocks), using a UV-B source (0.5 mW/cm2), with openings of 1 cm2, in increasing doses. The same areas were evaluated with a Minolta CR 300 Chromameter (L*a*b* system). The MED values ranged from 13 to 156 mJ/cm2; the coordinate L* (brightness) ranged from 75.96 to 30.15. The correlation between the MED and the brightness was negative in both areas (Pearson's correlation r =,0.91, P < 0.05). Color measurements, especially brightness, can be used to quickly assess skin sensibility. Considering the MED, there is a substantial overlapping of adjacent phototypes, but they could be separated into two groups: more sensitive individuals (Types I, II, III and IV) and less sensitive ones (Types V and VI). [source] Revisiting Jung's concept of innate sensitivenessTHE JOURNAL OF ANALYTICAL PSYCHOLOGY, Issue 3 2004Elaine N. Aron Abstract:, Jung suggested that innate sensitiveness predisposes some individuals to be particularly affected by negative childhood experiences, so that later, when under pressure to adapt to some challenge, they retreat into infantile fantasies based on those experiences and become neurotic. Recent research by the author and others is reviewed to support Jung's theory of sensitiveness as a distinctly thorough conscious and unconscious reflection on experiences. Indeed, this probably innate tendency is found in about twenty percent of humans, and, in a sense, in most species, in that about this percentage will evidence a strategy of thoroughly processing information before taking action, while the majority depend on efficient, rapid motor activity. Given this thorough processing, sensitive individuals readily detect subtleties,including whatever is distressing or threatening. Hence, as Jung observed, given the same degree of stress in childhood as non-sensitive individuals, sensitive persons will develop more depression, anxiety, and shyness. Without undue stress, they evidence no more of these difficulties than the non-sensitive,or even less, being unusually aware of supportive as well as negative cues from caregivers. Given this interaction, one treatment task is to distinguish the effects of such childhood difficulties from what does not need treatment, which are the typical effects of the trait itself on an adult without a troubled developmental history. [source] | ||||||||||