Induction Experiments (induction + experiment)

Distribution by Scientific Domains


Selected Abstracts


Trait emotional intelligence: behavioural validation in two studies of emotion recognition and reactivity to mood induction

EUROPEAN JOURNAL OF PERSONALITY, Issue 1 2003
K. V. Petrides
This paper presents two experiments concerning trait emotional intelligence (,trait EI'). In study 1, ten high and ten low trait EI individuals were selected from a sample of 85 persons to participate in a computerized experiment involving the recognition of morphed emotional expressions. As hypothesized, high trait EI participants were faster at identifying the expressions than their low trait EI counterparts. In study 2, trait EI scores from 102 persons were residualized on the Big Five and subsequently 15 high and 15 low trait EI individuals were selected to participate in a mood induction experiment. As hypothesized, high trait EI participants exhibited greater sensitivity to the mood induction procedure than their low trait EI counterparts. The findings are discussed in terms of the construct validity of trait EI, with particular emphasis on the issue of incremental validity vis-à-vis broad personality traits. Copyright © 2002 John Wiley & Sons, Ltd. [source]


Isoform-specific quantification of metallothionein in the terrestrial gastropod Helix pomatia.

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2004

Abstract The two function-specific metallothionein (MT) isoforms characterized from the midgut gland and mantle tissue of Helix pomatia differ substantially in their metal-binding preferences, as well as molecular and biochemical features. These differences make them potential candidates for biomarker studies based on a differential, isoform-specific approach. To prove this hypothesis, induction experiments with two metals (Cd and Cu) that are normally bound by the two isoforms were compared with a range of organic chemicals and physical stressors under laboratory conditions to test the responsiveness of the two isoforms to the stressors applied. In addition, field studies were conducted with Roman snails and substrate samples collected from different metal-contaminated sites in Austria to test the suitability of the two isoforms as biomarkers under field conditions. The results of these combined laboratory and field studies confirmed the validity of the biomarker approach with the two metal- and tissue-specific isoforms. It is demonstrated that the Cd-binding MT specifically and exclusively responds to Cd exposure by increasing concentrations, whereas the Cu-binding MT isoform decreases in its concentration upon exposure to physical stress (X-ray irradiation and cold). This suggests researchers should adopt, under certain preconditions, a dual biomarker approach by combining the simultaneous quantification of Cd-MT concentrations in the midgut gland as a biomarker for Cd pollution and of Cu-MT concentration in the mantle as a biomarker for the impairment of snails by additional physical stressors. [source]


Cell proliferation and apoptosis: dual-signal hypothesis tested in tuberculous pleuritis using mycobacterial antigens

FEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 1 2004
Sulochana D. Das
Abstract Antigens and mitogens have the innate ability to trigger cell proliferation and apoptosis thus exhibiting a dual-signal phenomenon. This dual-signal hypothesis was tested with mycobacterial antigens (PPD and heat killed Mycobacterium tuberculosis, MTB) in tuberculous pleuritis patients where the immune response is protective and compartmentalized. We compared and correlated the cell-cycle analysis and antigen-induced apoptosis in normal and patients' peripheral blood mononuclear cells (PBMCs) and patients' pleural fluid mononuclear cells (PFMCs). In cell-cycle analysis, PFMCs showed good mitotic response with PPD and MTB antigens where 10% and 7% of resting cells entered the S and G2/M phases of cell cycle, respectively. This antigen-induced proliferation of PFMCs correlated well with the lymphocyte transformation test (LTT) results. On the other hand, PFMCs also showed 21% of spontaneous apoptosis, which further increased to 43%, by induction with known apoptotic agent like Dexamethasone (DEX) and the mycobacterial antigens PPD and MTB. Further we demonstrated by anti-CD3 induction experiments that prior activation of cells is prerequisite for them to undergo apoptosis. Our results showed that PPD and MTB antigens induced both cell proliferation and apoptosis in PFMCs, which were pre-sensitized to mycobacterial antigens in vivo. Thus the dual-signal phenomenon was operative against these antigens in tuberculous pleuritis. We also demonstrated that the activated cells are more predisposed to apoptosis. [source]


Poor phenotypic integration of blue mussel inducible defenses in environments with multiple predators

OIKOS, Issue 5 2009
Aaren S. Freeman
Aquatic prey encounter an array of threat cues from multiple predators and killed conspecifics, yet the vast majority of induced defenses are investigated using cues from single predator species. In most cases, it is unclear if odors from multiple predators will disrupt defenses observed in single-predator induction experiments. We experimentally compared the inducible defenses of the common marine mussel Mytilus edulis to waterborne odor from pairwise combinations of three predators representing two attack strategies. Predators included the sea star, Asterias vulgaris (=Asteriasrubens), and the crabs Carcinus maenas and Cancer irroratus. The mussels increased adductor muscle mass in response to cues from unfed Asterias (a predatory seastar that pulls mussel shells open) and increased shell thickness in response to unfed Carcinus, a predatory crab that crushes or peels shells. However, the mussels did not express either predator specific response when exposed to the combined cues of Asterias and Carcinus, and mussels did not increase shell thickness when exposed to cues from Cancer alone or any pairwise combination of the three predators. Shell closure or ,clamming up' did not occur in response to any predator combination. These results suggest that predator-specific responses to the Asterias and Carcinus are poorly integrated and cannot be expressed simultaneously. Simultaneous cues from multiple predators affect the integration of predator specific defenses and predator odors from functionally similar predators do not necessarily initiate similar defenses. Ultimately, the degree that prey can integrate potentially disparate defenses in a multiple predator environment may have ecological ramifications and represent a seldom explored facet of the evolution of inducible defenses. [source]