2003 Program Abstracts

 

The Effect of Females on Male-Male Competition in the Marine Isopod, Paracerceis sculpta

Emily Arnold and Stephen M. Shuster

We examined interactions between a-males in arenas that lacked this species’ usual reproductive habitat (sponges), while in the presence and in the absence of sexually receptive females. Resident males occupied arenas with females for 1 hr before intruders were introduced. Residents and intruders engaged in significantly more total acts (F[3,79]=3.48, P=0.02) and grappled more (F[3,79]=3.67, P=0.02) in the presence of females than when females were absent. Also, residents became active first and contacted females more (F=5.90, p<0.02) than intruders. When receptive females were present, latency to activity was significantly longer than when females were absent (F= 12.10, p<0.003). However, compared to the number of contests with females present (N=14), the number of contests observed in the absence of females were few (N=4). Our results indicate that a-males will compete for females outside of their normal breeding habitat, and that in such circumstances, males recognize their status as residents and intruders. Our results suggest that contests for mates and mating attempts outside of sponges may be common in nature.

 

All-clear call distance variation in Gunnison’s Prairie Dogs(Cynomys Gunnisoni)

J.M. Ballesteros and C.N. Slobodchikoff

 Gunisson’s prairie dogs, Cynomys gunnosoni, use vocalizations for communication in their social assemblages.  Antipredator alarm calls have been identified in these animals that vary accordingly to the species of the animal eliciting the call.  This experiment looked for the presence of an “all clear” call that is believed to be used to signal when a predator has left the animal colony and thus complement an antipredator call.  A series of experiments were undergone to measure the distance from the prairie dog and acoustic parameters of the “all clear” call when exposed to a human predator.  Pooled data from four sites found a significant difference(p<0.001) in the distance to the human predator between an antipredator and suspected “all clear” calls.  These results provide evidence towards the existence of an “all clear” call that can be further expanded by studying the “all clear” calls acoustic variables.

 

Feeding Behavior of Poecilia sphenops: Kinematics of a novel jaw
protrusion mechanism
 
J.M. Blanton and A.C. Gibb
 

Upper jaw protrusion in fish is assumed to enhance prey capture by creating forward expansion of the mouth during feeding. Protrusion is theorized to have evolved independently in several lineages, namely the order Cypriniformes and the orders Perciformes and Cyprinidontiformes. For this study, we compared Poecilia sphenops with data previously collected of Danio rerio and Betta splendens.  The species represent each lineage: Danio (Cypriniformes), Betta (Perciformes) and Poecilia (Cyprinidontiformes). We hypothesized that Betta and Poecilia, because of shared ancestral lineage, would be more similar in feeding behavior to each other than to Danio. Digital images of Poecilia were taken to measure ten head displacement variables during feeding. We used Principal Component Analysis and ANOVA to analyze these measurements. We found Betta and Danio similar to each other, but both significantly different from Poecilia. Poecilia were significantly slower for all timing variables. Displacement variables were larger in Poecilia, excepting cranial rotation and lower jaw displacement. Difference could be due to difference in jaw mechanism. Poecilia has little rotation at the suspensorium-lower jaw joint (where rotation occurs in most fishes), and a secondary, previously undescribed joint in the anterior lower jaw allowing dentary protrusion and flexion. The upper jaw consists of a fixed maxilla (where movement occurs in other fish, causing premaxillary protrusion) and a premaxilla with extreme protrusion.  From these findings, we propose a new mechanism for Poecilia, describing the phenomenon of intramandibular bending and a new model for upper jaw protrusion and retraction.  Such a different jaw mechanism could be attributed to specialized functions Poecilia probably uses its flexible jaws for scraping algae off of vegetation and hard substrate.

 

Religious coping and its relationship to disease progression, socio-economic status, and social support in HIV+ patients who experienced Hurricane Andrew

 T. Halloran, A.D. Kittur,  M.A. Antoni,  K.M. Kilbourn

 The use of religion and spirituality as a coping strategy for those experiencing a major life stressor has received wide-spread attention over the past few years.  There remain a number of unanswered questions regarding the relationship of religious coping to other variables such as social support, socio-economic status (SES) and health outcome.   This study examined the relationship between religious coping (COPE), SES (income and education level), disease progression (CD4 #), and social support coping in 40 HIV+ gay men who experienced Hurricane Andrew.  A situational specific form of the COPE was administered to each participant instructing them to anchor their responses to hurricane-related events.  Results found that the use of religious coping following the hurricane was significantly associated with the use of emotional social support (r = .39) and disease progression (r = -.36).  Religious coping was negatively associated with income (r = -.46) and education (r = -.42).  Instrumental social support was negatively correlated with education (r = -.38). A regression analysis was conducted to predict the relative contribution of SES, disease progression, and emotional social support to the use of religious coping.  SES and CD4# accounted for accounted for 17% and 8% of the variance in religious coping scores and emotional social support predicted an additional 15% of the variance beyond SES and CD4#.  Overall, this model accounted for 48% of the variance in religious coping scores (R2 = .45, p < .01).  These results demonstrate that SES, disease progression and emotional social support make independent contributions to the use of religious coping.  Individuals who are sicker and/or who are of lower SES tend to use more religious coping.  Our findings support the inclusion of religious and spiritual coping techniques in psychosocial interventions for chronically ill individuals.

 

Coping, distress, and Catecholamine levels in HIV+ men

Alvina Kittur, Terri Halloran,  Michael Antoni,  Kristin Kilbourn

 Coping with a chronic stressor, such as HIV, requires the use of beneficial coping strategies.  Recently, active coping efforts have been shown to be more effective than passive ones.  This study examines the relationship between active coping styles, distress (IES), and epinephrine in HIV+ men who experienced Hurricane Andrew.  Participants were measured once immediately after Hurricane Andrew (time 1, n= 44), and again two years later (time 2, n= 24).  A situational specific form of both the COPE and the IES was administered to each participant instructing them to anchor their responses to HIV-related events.  Urine samples were analyzed for levels of epinephrine.  Results showed that time 2 distress was significantly associated with active coping (r= -.488 , p<.05 ), planning (r= -.630, p<.005), and the use of instrumental (r= -.464, p<.05)and emotional (r= -.520, p<.05) social support at time 1.  The use of instrumental social support was correlated with epinephrine levels at time 2 (r= -.456 , p<.05).  Planning was correlated with IES at time 2 (r= -.630 , p<.005).  A regression analysis of epinephrine (time 2) showed that 13% of the variance in epinephrine levels (time 2) was due to the use of instrumental social support, and 32% was due to time 1 epinephrine levels.  Another regression analysis showed that 15% of the variance in distress level at time 2 (IES) was due to active coping, and 54% was due to IES (time 1) scores.  This data suggests the possible long term buffering effect of active coping styles on both HIV-specific distress and neuroendocrine levels.

 

 Does free female mate choice affect fecundity in the confused flour beetle, Tribolium confusum?

Jay Nagtalon, Stephen M. Shuster and Lee C. Drickamer

Although mate choice is presumed to affect individual fitness, the effect of mate choice on offspring numbers is seldom investigated.  To test whether female flour beetles, Tribolium confusum, actively choose males, and whether those choices affect their fecundity, we allowed virgin females to select mates, and then bred them with virgin males that females preferred or did not prefer. As a control we also mated virgin females to virgin males at random. Using ANOVA, we compared the 40 day productivities of all females by mating class (Ncrosses=30, Nprogeny=3,500). Our results showed that while females actively chose males,  the number of offspring produced by females bred either with preferred, non-preferred, or random males, did not differ significantly between groups (F[2,29]=0.86, p=0.44).  Thus, contrary to current “good genes” predictions, free female mate choice in T. confusum showed no effect on female fecundity.

 

The Effect of Reclaimed Wastewater on Western Mosquitofish

(Gambusia affinis) Survivorship

 Somley, B.L.; Hortin, S.M.; Powell, L.D.; Scott, N.A.; Moreno, V.N.; Shah, P.J.; Phillips, J.D.; Westmoreland, K.L.; Propper, C.R.

This study investigated the endocrine disrupting potential of reclaimed wastewater. We hypothesized that the wastewater treatment process may not have sufficiently removed all androgenic xenobiotics. Female western mosquitofish (Gambusia affinis) were utilized as bioindicators because they develop elongated anal fins upon exposure to androgens. The Gambusia were treated with conditioned reverse osmosis water (CRO) or reclaimed wastewater (WW, n=20 per treatment). Prior to and following treatment, each fish was weighed, and the total body length and anal fin rays’ lengths were determined. The study was designed to continue treatment of the fish for 30 days, but 13 days after treatment a significant quantity of the WW-treated fish died (p = 0.0012). Due to this high mortality rate, the remaining fish were sacrificed early. Analysis of the water indicated that the WW had significantly lower dissolved oxygen levels than the CRO water (p < 0.0001). There was a significant decrease in condition factor (p < 0.0445) and in the degree of anal fin elongation in the WW-treated group (p = 0.05) indicating no masculinization effect. Further examination of the WW indicated the presence of several microorganisms. These microorganisms may have come from the activated sludge or they may have also colonized the wastewater during transport and/or storage at the reclaimed water tank. Two non-mutually exclusive hypotheses may explain the mortality of the WW-treated fish. The microorganisms may have contributed to the depletion in oxygen levels, compromising the health of the fish, or the organisms may have caused infection or the release of plant toxins.  

 

Using the Rasch model to increase the reliability of the Picture Story Exercise

Christopher Vega and Virginia Blankenship

The Thematic Apperception Test (TAT) or Picture Story Exercise (PSE) is a widely used measure of motivation. In two experiments the Rasch (1980) model was used to develop ten new pictures to measure need for achievement (nAch) and to revise the coding system for nAch. In experiment one, stories from 320 participants were analyzed by paragraphs to assess the difficulty level of eight pictures. Six pictures were retained and four new ones added for experiment two, in which 201 participants wrote six stories to a random set of the ten new pictures. The multi-faceted Rasch model was used in both experiments with item difficulty, participant ability, and coder leniency as facets in a partial credit model. Results from FACETS, a computer program based on the Rasch model (Linacre , 2001), indicate that the ten-picture PSE has substantial reliability for participants of .86 (comparable to coefficient alpha). The Person Separation Index of 2.47 indicates that the sample can be divided confidently into two groups, High versus Low. A revised coding system incorporating assumptions of the Rasch model is presented, and the usefulness of the Rasch model for improving the items on an implicit or projective test is discussed.