Audience effects in the Atlantic molly (Poecilia mexicana)–prudent male mate choice in response to perceived sperm competition risk?

Background Multidirectional interactions in social (or communication) networks can have a profound effect on mate choice behavior. For example, Poecilia mexicana males show weaker expression of mating preferences when being observed by an audience male. It was suggested that this behavior is an adaptation to reduce sperm competition risk, which arises because commonly preferred female phenotypes will receive attention also by surrounding males, and/or because the audience male can copy the focal male's mate choice. Do P. mexicana males indeed respond to perceived sperm competition risk? We gave males a choice between two females and repeated the tests under one of the following conditions: (1) during the 2nd part of the tests an empty transparent cylinder was presented (control); (2) an audience male inside the cylinder observed the focal male throughout the 2nd part, or (3) the audience male was presented only before the tests, but could not eavesdrop during the actual choice tests (non-specific sperm competition risk treatments); (4) the focal male could see a rival male sexually interacting with the previously preferred, or (5) with the non-preferred female before the 2nd part of the tests (specific sperm competition risk treatments). Results When comparing the strength of individual male preferences between the 1st and 2nd part of the tests (before and after presentation of an audience), male preferences declined slightly also during the control treatment (1). However, the decrease in strength of male preferences was more than two-fold stronger in audience treatment (2), i.e., with non-specific sperm competition risk including the possibility for visual eavesdropping by the audience male. No audience effect was found in treatments (3) and (5), but a weak effect was also seen when the focal male had seen the previously preferred female sexually interact with a rival male (treatment 4; specific sperm competition risk). Conclusions When comparing the two 'non-specific sperm competition risk' treatments (2 and 3), a very strong effect was found only when the audience male could actually observe the focal male during mate choice in treatment (2). This suggests that focal males indeed attempt to conceal their mating preferences in the visual presence of other males so as to avoid mate choice copying. When there is no potential for eavesdropping [treatment (3)], non-specific specific sperm competition risk seems to play a minor or no role. Congruent with studies on other poeciliid species, our results also show that P. mexicana males respond to perceived specific sperm competition risk, and tend to share their mating effort more equally among females when the resource value of their previously preferred mate decreases (after mating with a rival male). However, this effect is comparatively weak

H1-antihistamine up-dosing in chronic spontaneous urticaria: patients' perspective of effectiveness and side effects--a retrospective survey study.

BACKGROUND: The guidelines recommend that first line treatment of chronic spontaneous urticaria should be second generation non-sedating H(1)-antihistamines with a positive recommendation against the use of old sedating first generation antihistamines. If standard dosing is not effective, increasing the dosage up to four-fold is recommended. The objective of this study was to obtain the chronic spontaneous urticaria-patient perspective on the effectiveness and unwanted effects of H(1)-antihistamines in standard and higher doses. METHODOLOGY/PRINCIPAL FINDINGS: This was a questionnaire based survey, initially completed by 368 individuals. 319 (248 female, 71 male, median age 42 years) had a physician-confirmed diagnosis of chronic spontaneous urticaria and were included in the results. Participants believed standard doses (manufacturers recommended dose) of second generation antihistamines to be significantly (P<0.005) more effective than first generation drugs. Furthermore, they believed that second generation drugs caused significantly (P<0.001) fewer unwanted effects and caused significantly (P<0.001) less sedation than first generation antihistamines. Three-quarters of the patients stated that they had up-dosed with antihistamines with 40%, 42% and 54% reporting significant added benefit from taking 2, 3 or 4 tablets daily respectively. The number of reports of unwanted effects and sedation following up-dosing were not significantly different from those reported for standard doses. CONCLUSIONS: This survey supports the urticaria guidelines recommendations that the first line treatment for chronic spontaneous urticaria should be second generation rather than first generation H(1)-antihistamines and that, if standard dosing is not effective, the dosage should be increased up to four-fold

The comparative efficacy first and second generation H₁-antihistamines in chronic spontaneous urticaria.

<p>The histograms were constructed from 147 and 721 patient reports respectively.</p

The spectrum of H₁-antihistamines taken by the patients for the treatment of their chronic spontaneous urticaria.

<p>The results are expressed as the total number of participants who reported information on the efficacy of the itemized antihistamines in regular dose.</p

Unwanted effects and sedation while using standard doses or up-dosing with H₁-antihistamines in chronic spontaneous urticaria.

<p>The reports included in this table are from patients who had taken either the standard dose or two, three or four times the standard dose each day of a second generation H₁-antihistamine. Statistical comparisons were made using Fisher's exact test. n indicates the number of reports received for each condition.</p

Effectiveness of H₁-antihistamine updosing in chronic spontaneous urticaria.

<p>The reported effectiveness of up-dosing with second generation H₁-antihistamines compared with standard dose therapy in chronic spontaneous urticaria. The number of patient reports in each group are; 2 tablets = 108, 3 tablets = 72 and 4 tablets = 85.</p

Comparison of first and second generation H₁-antihistamines in chronic spontaneous urticaria.

<p>The first generation ‘sedating’ antihistamines were clemastine, dimethindene, hydroxyzine and promethazine and the second generation, ‘non-sedating’ antihistamines were cetirizine, desloratadine, ebastine, fexofenadine, levocetirizine, loratadine, mizolastine and rupatadine. All were taken at the standard licensed dose. Statistical comparisons were made using Fisher's exact test. n indicates the number of reports received for each condition.</p