Inhibition of the LH Surge by Restraint Stress in Cyclic Rats: Studies on the Role of GABAA and GABAB Receptors

There is evidence that stress can alter the activity in the brain of gamma-aminobutyricacid (GABA), a neurotransmitter that has been implicated in the regulation of LH secretion. In the present study the role of GABA in the restraint stress-induced inhibition of the LH surge was investigated in the intact cyclic rat. Intracerebroventricular (icv) administration of the GABAA receptor agonist muscimol (0.1, 0.5 or 1 μg) 5 min before the presumed onset of the pro-oestrous LH surge (at 0900 h) caused a dose dependent suppression of the surge. A single dose of the GABAB receptor agonist baclofen (1 μg; icv) injected at 0855 h postponed the onset of the LH surge, and repeated injections at 0855 and 1130 h suppressed the surge. These data indicate that GABA-ergic activity in the brain can inhibit the LH surge in the cyclic rat via GABAA and GABAB receptors. Pro-oestrous rats were subjected to 5 hrs of restraint starting at 0855 h. Pretreatment with the GABAA receptor antagonist bicuculine (1 μg; icv) at 0840, 0940 and 1040 h or pretreatment with the GABAB receptor antagonist phaclofen (10 μg; icv) at 0840 h were ineffective in preventing the restraint-induced inhibition of the LH surge. The results suggest that GABAA and GABAB receptors are not involved in the inhibitory effect of restraint stress on the LH surge.     

Strategic aspects of numerosity judgment: the effect of task characteristics

In previous investigations we documented that people use several strategies to determine different numerosities of blocks that are presented in a square grid. One of these strategies is the clever subtraction strategy, wherein the number of empty squares in the grid is subtracted from the total number of squares in the grid. In the present study we investigated participants' flexibility in strategy use when varying the shape of the grid. Analysis of the results in terms of the theoretical framework of Lemaire and Siegler (1995) regarding strategic change shows that this contextual variable affected the frequency, execution time, and accuracy of subjects' use of the subtraction strategy. The usefulness of this framework for analyzing the nature of the adaptation to contextual variations is discussed. From a methodological point of view, this study documents the potential of Beem's (1993, 1999) segmented linear regression models for assessing subjects' strategy use in cognitive tasks.     

Diurnal variation,morningness-eveningness,and momentary affect

The research questions of this study are the following: To what degree can results such as those of Thayer and colleagues (1978a, 1985, 1986, 1988) concerning diurnal variation and differences between diurnal types, obtained for energetic and tense arousal, be (1) replicated, (2) extended to elation and pleasantness, and (3) generalized to positive and negative affect? With regard to energetic arousal, all results were in line with those of Thayer and colleagues. However, regarding tense arousal, there was an unexpected main effect for time of day. For energetic arousal, elation, pleasantness, positive affect, and negative affect, there was (a) a significant main eflect for time of day, (b) a quadratic trend for diurnal variation, and (c) a significant Diurnal Type × Time of Day interaction, There were no significant sex differences in diurnal variation. Two final hypothetical statements are made about the diurnal variation and differences between diurnal types with regard to state scales: (a) the diurnal variation of a state scale cannot be described with a quadratic function if that scale is completely unrelated to energetic arousal; and (b) the characteristic differences between morning types and evening types, especially when measured in the morning and in the evening, will not manifest themselves on a state scale if that scale is entirely unrelated to energetic arousal. Finally, the possible usefulness of the results of this study for practical applications and the development of theories are discussed.     

The conceptual structure of sex role stereotypes in college students

This study investigated sex stereotypes as natural language categories. Ten years ago, sex stereotypes were found to have a core-peripheral structure similar to that of the nonevaluative categories studies by Rosch (1973). Changes and stability in these conceptions were studied by having 56 female and 56 male undergraduate students rate 217 adjectives on Likert scales according to how well each adjective represented their own view of typical Men or Women. Mean ratings were analyzed to reveal a structure of core, peripheral, and nonmembers for Men and for Women. As was the case ten years ago, core traits reflected dimensions of “niceness-nurturance” for Women and “potency-strength” for Men. Female students also viewed Women as “competent,” while male students also viewed Women as “socially effective.” Adjectives that constituted the core for one category were generally placed in the periphery for the other category. As compared to ten years ago, the peripheries of the categories were expanded and showed a greater degree of overlap. College students' conceptions of Men and Women are best characterized as overlapping rather than as bipolar opposites. The formation of sex stereotype categories was discussed in terms of cognitive and social learning processes.     

WOMEN, LEADERSHIP, AND EMPOWERMENT

This paper is a review of leadership research, focusing primarily on women as leaders. The more recent perspective of studying leaders by examining followers is included; but research is sparse as to how leaders are perceived as empowering by their subordinates. A study in progress, conducted by Denmark, Nielson, and Scholl, indicates that stereotypes were more typically held by women against female leaders. However, a leader's ability to be empowering varies with status. The higher the status, the more empowering that individual is perceived, whether female or male. Yet, more men than women held higher status positions. More women are needed in high-level positions to better assess leadership and empowerment.     

The role of anionic, imidic and amidic forms in structure-activity relationships. Conjugation and bacteriostatic activity in sulphonamides.

The electronic structures of anionic, imidic and amidic forms of sulphonamides were investigated and compared by means of I.R., Raman and U.V. spectroscopy. Indices reflecting the electronic situation of the common moiety p-H2N-C6H4-SO2 was a whole, although not necessarily related, physically, to any event taking place in the biological processes, were found to correlate with the in vitro bacteriostatic activity of the specific individual forms. The influence of N1-substituents both on the SO2 electronic features and on the coupling between the para amino group and the phenyl ring was discussed. It resulted that the most active chemical species, in this class of compounds, are characterized, electronically, by the most electron-rich common moiety and, in particular, by the most negative oxygens in the SO2 group and the most available (less engaged) lone-pair in the rho-amino group. These conclusions give a new settlement both to the problem of resonance and to the relation between resonance effects and bacteriostatic activity in this class of compounds.     

Procedural fairness and endorsement of prototypical leaders: Leader benevolence or follower control?

This research explored why strongly identifying followers endorse prototypical leaders by addressing the role of procedural fairness in this process. We introduced the distinction between procedural fairness rules relating to leader benevolence (i.e., whether the leader supports the group’s interests) and follower control (i.e., whether followers can influence the leader’s decisions). We predicted that strongly identifying group members endorse prototypical leaders because they perceive such leaders as acting in line with benevolence related fairness rules rather than because such leaders are perceived as giving followers control. An organizational field study and a laboratory experiment revealed support for these ideas. Our results thus provide insights into why prototypical leaders are endorsed among strongly identifying followers. They also have implications for the procedural fairness literature in showing that frequently studied procedural fairness rules (e.g., voice) do not explain endorsement of leaders believed to support the group’s interests.     

Longer-term consequences of anger expression in negotiation: Retaliation or spillover?

Negotiators often concede to angry partners. But what happens when they meet again? According to the spillover hypothesis, negotiators demand less from previously angry partners because they perceive them as tough. According to the retaliation hypothesis, negotiators demand more from previously angry partners because of negative impressions and a desire to get even. Experiment 1 showed that participants demanded less in later negotiations when their partner in a previous negotiation had expressed anger (rather than no emotion) and the later negotiation was with the same (rather than a different) partner. Consistent with the spillover hypothesis, this effect was mediated by inferences regarding the partner’s toughness. Experiment 2 showed that apologies reduce the negative effects of anger on impressions and desire for future interaction. Behavioral reactions were moderated by social value orientation: extending the established might/morality effect, prosocial participants responded cooperatively to an apology, whereas proselfs responded competitively.     

Effect of a kickboxing match on salivary cortisol and immunoglobulin A

The hypothesis that salivary cortisol would increase and salivary immunoglobulin A (IgA) decrease after a kickboxing match was tested among 20 male athletes. Saliva samples collected before and after the match were analyzed. Salivary cortisol and salivary IgA concentrations (absolute concentration, salivary IgAabs) and the secretion rate of IgA (salivary IgArate) were measured by enzyme-linked immunosorbent assay. A Wilcoxon test for paired samples showed significant increases in salivary cortisol from pre- to postmatch. No significant changes were observed in salivary IgAabs or secretory IgArate and saliva flow rate. This study indicates that a kickboxing match might increase salivary concentration and thereafter it could be considered a significant source of exercise-related stress. On the other hand, the effect of a kickboxing match on mucosal immunity seems not to be relevant.