Effects of apomorphine on mating behavior, flank marking and aggression in male hamsters

In male rats, the dopamine agonist apomorphine (APO) generally facilitates copulatory behavior. However, disruptive effects of high APO doses have been reported. These have been interpreted in diverse ways, as products of a dopaminergic system that inhibits sexual behavior or as consequences of APO's stimulation of competing responses. To test the generality of these effects, we observed APO's impact on copulatory behavior in male hamsters. Several effects were observed, all attributable to a relatively high dose and involving the disruption of male behavior. More unexpectedly, APO treatment caused males to attack estrous stimulus females in the course of these tests. To clarify these effects, we observed the effects of APO on flank marking, a type of scent marking closely allied to aggression and dominance in hamsters. Treatment reliably decreased the latency of marking. It also increased the rate of marking when appropriate measures were taken to prevent this effect from being obscured by drug-induced cheek pouching. Together, these results confirm and extend APO's well-known ability to increase aggression. Further, they suggest that APO-induced aggression can intrude into other contexts so as to disrupt, or possibly facilitate, other forms of social behavior.

Individual Differences in First and Fourth Year College Women’s Short Term Mating Strategy Preferences and Perceptions

Using survey methodology, a cross sectional study was undertaken to ascertain whether first and fourth year college women have different perceptions and behavior associated with short term mating preferences. It was hypothesized that after incurring significant negative or costly experiences associated with hooking up, fourth year women would prefer men who had qualities associated with a desired long term partner as opposed to characteristics associated with short term mating partners. The results were partially consistent with the hypothesis. Reported preferences in a desired partner and perspective on hooking up differ between first and fourth year groups. No difference was found between frequency and willingness to hookup between the two groups. The findings are explained in terms of evolutionary theory, social exchange theory, and sexual script concepts.

Chemical Compatibility of Model Soil-Bentonite Backfill Containing Multiswellable Bentonite

The objective of this study was to evaluate the chemical compatibility of model soil-bentonite backfills containing multiswellable bentonite (MSB) relative to that of similar backfills containing untreated sodium (Na) bentonite or a commercially available, contaminant resistant bentonite (SW101). Flexible-wall tests were conducted on consolidated backfill specimens (effective stress =34.5 kPa) containing clean sand and 4.5–5.7% bentonite (by dry weight) using tap water and calcium chloride (CaCl2) solutions (10–1,000 mM) as the permeant liquids. Final values of hydraulic conductivity (k) and intrinsic permeability (K) to the CaCl2 solutions were determined after achieving both short-term termination criteria as defined by ASTM D5084 and long-term termination criteria for chemical equilibrium between the influent and effluent. Specimens containing MSB exhibited the smallest increases in k and K upon permeation with a given CaCl2 solution relative to specimens containing untreated Na bentonite or SW101. However, none of the specimens exhibited more than a five-fold increase in k or K, regardless of CaCl2 concentration or bentonite type. Final k values for specimens permeated with a given CaCl2 solution after permeation with tap water were similar to those for specimens of the same backfill permeated with only the CaCl2 solution, indicating that the order of permeation had no significant effect on k. Also, final k values for all specimens were within a factor of two of the k measured after achieving the ASTM D5084 termination criteria. Thus, use of only the ASTM D5084 criteria would have been sufficient to obtain reasonable estimates of long-term hydraulic conductivity for the specimens in this study.

Individual differences in first and fourth year college women’s short term mating strategy preferences and perceptions

Using survey methodology, a cross sectional study was undertaken to ascertain whether first and fourth year college women have different perceptions and behavior associated with short term mating preferences. It was hypothesized that after incurring significant negative or costly experiences associated with hooking up, fourth year women would prefer men who had qualities associated with a desired long term partner as opposed to characteristics associated with short term mating partners. The results were partially consistent with the hypothesis. Reported preferences in a desired partner and perspective on hooking up differ between first and fourth year groups. No difference was found between frequency and willingness to hookup between the two groups. The findings are explained in terms of evolutionary theory, social exchange theory, and sexual script concepts.

Responses to Central Oxotremorine and Scopolamine Support the Cholinergic Control of Male Mating Behavior in Hamsters

The responses of hamsters to intracranial injections of the cholinergic agonist oxotremorine (OXO) implicate cholinergic mechanisms in the medial preoptic area (MPOA) in the control of male mating behavior. To extend these observations, we ran three studies of responses to cholinergic drugs delivered singly or in combination to the vicinity of the MPOA. The first tested responses to OXO, confirming its ability to reduce the postejaculatory interval. The second complemented the first by examining responses to MPOA microinjections of the cholinergic antagonist scopolamine (SCO). These caused several changes revolving around intromission. These included increases in intromission frequency and ejaculation latency. They also included a change in the patterning of intromissions, marked by continuous strings without the usual separation by dismounts. The final study resembled the others in examining the effects of MPOA injections of OXO and SCO but focused on the ability of each drug to antagonize responses to the other. Most of the responses to OXO and SCO individually replicated earlier findings, though the measures examined here also permitted the description of effects on some noncopulatory sexual behaviors, specifically the male's inspection of the female. However, the most interesting results may be those suggesting asymmetry in the responses to the addition of the second drug: Whereas responses to OXO tended to be antagonized by SCO, OXO was less effective at counteracting responses to SCO. Though the explanation of this asymmetry is not completely clear, it is consistent with previous suggestions of differences in the affinities of these drugs for subtypes of muscarinic receptors. Therefore, it suggests that the cholinergic synapses and circuits controlling distinct elements of male behavior could differ in their dependence on these receptors. Copyright 2013 Elsevier Inc. All rights reserved.

Mating Intelligence, Self-Esteem, Self-Perceived Attractiveness, And Partner Choice

The present research was conducted in two studies. The first study examined how mating intelligence, self-esteem, and self-perceived attractiveness are related to each other. The second study examined how these three constructs relate to partner choice. It was hypothesized that participants who score high on mating intelligence will also score high on self-esteem and self-perceived attractiveness. Furthermore, those that score high on self-esteem will also score high on self-perceived attractiveness. It was expected that the results would be more significant for women than for men. For the second study, it was hypothesized that participants who score high on all three constructs will be more likely to select the attractive partner. The results did not show a significant interaction between mating intelligence, self-esteem, and self-perceived attractiveness. They also did not indicate higher significance levels for women. However, there were significant effects between the constructs. Additionally, participants with an average or a high score on mating intelligence were more likely to select the attractive partner.

Chemical compatibility of soil-bentonite cutoff wall backfills containing modified bentonites

This study examined the chemical compatibility of several model soil-bentonite(SB) backfills with an inorganic salt solution (CaCl2). First, bentonite-water slurry was created using a natural sodium-bentonite, as well as two modified bentonites –multiswellable bentonite (MSB) and a “salt-resistant” bentonite (SW101). Once slurries that met typical construction specifications had been created using the various bentonites,the model SB backfills were prepared for each type of bentonite. These backfills werealso designed to meet conventional construction and design requirements. The SB backfills were then subjected to permeation with tap water and/or CaCl2 solutions of various concentrations in order to evaluate the compatibility of the SB backfills with inorganic chemicals. The results indicate that SB backfill experiences only minor compatibility issues (i.e., no large differences between the hydraulic conductivity of the SB backfill to tap water and CaCl2) compared to many other types of clay barriers. In addition, SB backfills show no major change in final hydraulic conductivity to CaCl2 when permeated with tap water before CaCl2 versus being permeated with CaCl2 directly. These results may be due to the ability of the bentonite in the SB backfills to undergo osmotic swelling before permeation begins, and the inability of the CaCl2 solutions to undo the osmotic swelling. Similar results were obtained for all three clays tested, and while MSB did show less compatibility issues than the natural bentonite and SW101, it appears that the differences in performance may generally be negligible. Overall, thisstudy makes a significant addition to the understanding of SB cutoff wall compatibility.