Exploring the Effects of Source Credibility and Message Framing on STI Screening Intentions: An Application of Prospect and Protection Motivation Theory

Roughly half of all new sexually transmitted infections (STI) occur in adolescent and college-aged populations. College students tend to underestimate their personal risks of contracting STIs. Consequently, many college students do not engage in protective behaviors that would reduce STI transmission rates. This study examined the effect of source credibility (high vs. low) and message framing (positive vs. negative) on college students’ behavioral intentions to get screened for STIs via a 2 × 2 experiment (n = 207). Further, drawing on both Prospect Theory and Protection Motivation Theory, the study tested whether coping and threat appraisals mediated the effects of source credibility and message framing on behavioral intentions. Results reveal that both highly credible sources and negatively framed messages influenced behavioral intentions to screen for STIs. However, the interaction term of source credibility by message frame was not significant. Mediation models suggested that efficacy perceptions partially explained the effect of source credibility on behavioral intentions, but not for the effect of message framing. Perceptions of severity and susceptibility did not mediate the effect of either source credibility or message framing. Practical and theoretical implications of the results are discussed.     

Alloimmunization to platelet-specific antigens on glycoproteins IIb- IIIa and Ib/IX in multiply transfused thrombocytopenic patients

The rate of alloimmunization to platelet-specific antigens associated with platelet glycoproteins (GPs) IIb-IIIa and Ib/IX was studied in 293 multiply transfused thrombocytopenic patients. Antibodies to platelet-specific antigens were measured with a solid-phase assay using platelet GP IIb-IIIa or Ib/IX as the antigenic targets. Nine patients were found to have antibodies to platelet GP IIb-IIIa, and no patients had antibodies to platelet GP Ib/IX. In six of these nine patients, the specificity of the antibody was shown by using GP IIb-IIIa from donors with different platelet-specific antigen phenotypes. In the remaining three patients with antibodies to platelet GP IIb-IIIa, no specificity could be identified. These patients had autoimmune thrombocytopenia in association with lymphoma. The alloimmunization rate to platelet-specific antigens associated with GP IIb-IIIa was 2 percent, whereas the rate of alloimmunization to HLA antigens was 23 percent. Of the patients alloimmunized to HLA antigens, 9 percent also had antibodies to platelet-specific antigens. A poor response to HLA-identical platelet transfusions was observed only in those patients with positive assays in the solid-phase test. These results suggest that the incidence of antibodies to platelet-specific antigens carried on GP IIb-IIIa is low. Platelet-specific antibodies may be found more frequently in patients alloimmunized to HLA antigens than in those not so alloimmunized.     

SSR591813, a novel selective and partial alpha4beta2 nicotinic receptor agonist with potential as an aid to smoking cessation

(5aS,8S,10aR)-5a,6,9,10-Tetrahydro,7H,11H-8,10a-methanopyrido[2',3':5,6]pyrano[2,3-d]azepine (SSR591813) is a novel compound that binds with high affinity to the rat and human alpha4beta2 nicotinic acetylcholine receptor (nAChR) subtypes (Ki = 107 and 36 nM, respectively) and displays selectivity for the alpha4beta2 nAChR (Ki, human alpha3beta4 > 1000, alpha3beta2 = 116; alpha1beta1deltagamma > 6000 nM and rat alpha7 > 6000 nM). Electrophysiological experiments indicate that SSR591813 is a partial agonist at the human alpha4beta2 nAChR subtype (EC50 = 1.3 micro M, IA =19% compared with the full agonist 1,1-dimethyl-4-phenyl-piperazinium). In vivo findings from microdialysis and drug discrimination studies confirm the partial intrinsic activity of SSR591813. The drug increases dopamine release in the nucleus accumbens shell (30 mg/kg i.p.) and generalizes to nicotine or amphetamine (10-20 mg/kg i.p.) in rats, with an efficacy approximately 2-fold lower than that of nicotine. Pretreatment with SSR591813 (10 mg/kg i.p.) reduces the dopamine-releasing and discriminative effects of nicotine. SSR591813 shows activity in animal models of nicotine dependence at doses devoid of unwanted side effects typically observed with nicotine (hypothermia and cardiovascular effects). The compound (10 mg/kg i.p.) also prevents withdrawal signs precipitated by mecamylamine in nicotine-dependent rats and partially blocks the discriminative cue of an acute precipitated withdrawal. SSR591813 (20 mg/kg i.p.) reduces i.v. nicotine self-administration and antagonizes nicotine-induced behavioral sensitization in rats. The present results confirm important role for alpha4beta2 nAChRs in mediating nicotine dependence and suggest that SSR591813, a partial agonist at this particular nAChR subtype, may have therapeutic potential in the clinical management of smoking cessation.     

Relationship between ankle frontal muscle powers and three-d gait patterns

OBJECTIVE: This study was undertaken to demonstrate that the ankle frontal muscle power absorption and generation at push-off are related to the foot's initial position at heel-strike with respect to the body center of mass. DESIGN: Nineteen able-bodied male subjects participated in this study and were divided into two groups according to ankle frontal plane power generation or absorption at push-off. RESULTS: At heel-strike, the group that absorbed had a center of pressure that was located on average 25% more anteriorly and 36% more laterally to the body center of mass. Moreover, at push-off, the center of pressure was closer (26%) to the center of mass than in the generating group. The absorbing group compensated by increasing their sagittal plane hip energy by 30% to pull the lower limb forward and their knee power absorption by 47% to slow down the leg before the subsequent heel-strike. CONCLUSIONS: The foot's initial position at heel-strike explains in part the ankle frontal power generation or absorption at push-off. Increasing hip and knee sagittal joint powers and mechanical energies were the main contributors in compensating and providing a broader base of support and frontal plane ankle power absorption.     

Adding Multimedia Cues to Medical Providers’ Online Biographies: Do Pictures,Video, and B-Roll Matter?

Developing engaging online healthcare provider biographies for prospective patients to consult is becoming a big business. Health-care systems are beginning to add more multichannel components—like videos—to these provider search tools at increasingly higher costs. Prior research finds that prospective patients desire videos offering additional footage (i.e., b-roll) displaying how a provider might interact with a patient during a consultation. Shooting and editing b-roll footage to add to providers’ videos takes additional time and resources. Using predictions and questions generated from uncertainty reduction and cue summation theories, this study sought to determine whether the addition of multichannel media (e.g., a video with added b-roll) offers any greater effects in the form of reduced uncertainty, provider likability, patient satisfaction, or trust than biographies providing fewer multichannel cues. A between-subjects online experiment randomly exposed participants (n = 523) to one of four biographies with increasing levels of multichannel components (i.e., text only biography, text with picture, video, video with b-roll). Results revealed that the two video biographies generated more significant effects than text-only biographies. However, the biography with just the video of the provider (i.e., a-roll only) and the video including added b-roll were not significantly different from one another on any of the dependent variables measured. These findings indicate that there may be a limit to the number of multichannel components needed to be an effective biography to help patients select their next healthcare provider. Both theoretical and practical implications of these results are discussed, in addition to future directions for research.