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Biomedical subjects

J Arndt

Publications and source records attributed to J Arndt.

At least 19 recordsLinked to original sources
PubMed2001

Vicarious annihilation: the effect of mortality salience on perceptions of hate crimes.

Previous research has found that reminding participants of their mortality creates a need for individuals to maintain and defend subjective cultural worldviews. As a result, mortality salient participants typically strive to uphold legal sanctions and also react negatively to individuals who espouse alternative worldview beliefs, exhibiting behaviors toward those targets ranging from verbal derogation to physical aggression. This paper extends this line of research by examining perceptions of hate crimes. Hate crimes represent a unique class of crime where both the perpetrator and victim may be viewed as worldview violators. Study 1 revealed that mortality salient participants were more supportive of hate crime legislation than were control participants when hate crimes were described in abstract terms and no specific victim was mentioned. In Study 2, a specific victim who posed a potential worldview threat was identified. In this case, mortality salient participants were less punitive toward offenders who attacked these specific worldview-threatening victims.

Analysis of Variance↗
PubMed2001

Being accepted for who we are: evidence that social validation of the intrinsic self reduces general defensiveness.

Three studies examined the possibility that being liked intrinsically by others--for who one is--reduces self-esteem defense, whereas being liked for what one has achieved does not. All 3 studies contrasted the effects on self-esteem defense of liking based on intrinsic or achievement-related aspects of self. Study 1 showed that thoughts of being liked intrinsically reduced defensive bias toward downward social comparison. Study 2 demonstrated that being liked for intrinsic aspects of self reduced participants' tendency to defensively distance themselves from a negatively portrayed other. Study 3 revealed that being liked for intrinsic aspects of self encouraged a preference for upward over downward counterfactuals for a negative event. In all 3 studies, similar reductions in defensiveness were not found when liking was based on achievements. Discussion focuses on implications for understanding the functional value of different bases of self-worth.

Achievement↗
PubMed2001

Midazolam amnesia and conceptual processing in implicit memory.

Prominent theories of implicit memory (D. Schacter, B. Church, & J. Treadwell, 1994) emphasize the dominant role of perceptual processing in mediating priming on perceptual implicit memory tests. Examinations of the effects of conceptual processing on perceptual implicit memory tests have produced ambiguous results. Although a number of investigations (e.g., J. Toth & R. Hunt, 1990) have demonstrated that variations in conceptual processing affect priming on perceptual implicit memory tests, these effects may arise because of the contaminating effects of explicit memory. The current experiment examined this controversy using midazolam, a benzodiazepine that produces a dense, albeit temporary, anterograde amnesia when injected prior to study. The experiment examined whether the effects of generation found on the implicit memory test of perceptual identification were affected by a midazolam injection prior to study. Results demonstrated that midazolam substantially diminished generation effects in free and cued recall, as well as overall performance on these tests, but had no detectable effect on the generation effect in perceptual identification.

Adult↗
PubMed2000

Running from the shadow: psychological distancing from others to deny characteristics people fear in themselves.

Four experiments tested the hypothesis that people distance themselves from others who display characteristics they fear in themselves. In Study 1, participants were given false feedback that they were high or low in repressed anger and were given information about a person who became angry and responded in a violent or nonviolent manner. High anger feedback participants distanced themselves only from the violent person. In Study 2, high anger feedback led to distancing from a violent other but not a dishonest other, whereas dishonesty feedback led to distancing from a dishonest other but not a violent other. The results of Studies 3 and 4 replicated and extended the distancing effect with an anger induction: Participants who were insulted distanced themselves from an angry/violent person, and verbalizing their emotions about being insulted eliminated this effect. Implications for understanding defenses against undesirable self-attributions are discussed.

Analysis of Variance↗
PubMed2000

Comparative dosimetry in narrow high-energy photon beams.

A comparison of the response of different dosimeters in narrow photon beams (phi > or = 4 mm) of 6 and 18 MV bremsstrahlung has been performed. The detectors used were a natural diamond detector, a liquid ionization chamber, a plastic scintillator and two dedicated silicon diodes. The diodes had a very small detection volume and one was a specially designed double diode using two parallel opposed active volumes with compensating interface perturbations. The characteristics of the detectors were investigated both for dose distribution measurements, such as depth-dose curves and lateral beam profiles, and for output factors. The dose rate and angular dependence of the diamond and the two diodes were also studied separately. The depth-dose distributions for small fields agree well for the diamond, the scintillator and the single diode, while the measured dose maximum for the double diode is about 1% higher and for the liquid chamber about 1% lower than the mean of the others when normalized at a depth of 10 cm. The plastic scintillator and the liquid ionization chamber detect a penumbra width that is slightly broadened due to the influence of their finite size, while the double diode may even underestimate the penumbra width due to its small size and high density. When corrected for the extension of the detector volume a good agreement with Monte Carlo calculated beam profiles was obtained for the plastic scintillator and the liquid ionization chamber. Profiles measured with the diamond show an asymmetry when positioned with the smallest dimension facing the beam, while the double diode, the scintillator and the liquid chamber measure symmetric profiles irrespective of positioning. Significant differences in the output factors were obtained with the different detectors. The natural diamond detector measures output factors close to those with an ionization chamber (less than 1% difference) for field sizes between 3 x 3 and 15 x 15 cm2, but overestimates the output factors for large fields and underestimates the output factors for the smallest field sizes. The single and double diodes overestimated the output factor for large field sizes by up to 7 and 12% respectively due to the high content of low-energy photons. The double diode, and to some extent the single diode, also showed a relative increase in response compared with the more water equivalent liquid chamber and plastic scintillator at the smallest fields where there is a lack of lateral electron equilibrium. Both the plastic scintillator and the liquid chamber also show responses that deviate from the ionization chamber for larger field sizes. The major deviations can be explained based on the characteristics of the sensitive materials and the construction of the detectors.

Dose-Response Relationship, Radiation↗
PubMed1999

The effect of midazolam on the modality-match effect in implicit memory.

Prominent theories of implicit memory claim that perceptual processes play a central role in implicit memory. The modality-match effect, the finding that priming is greater when the modality of stimulus presentation matches at study and test, provides the central evidence for these approaches. In this paper we use the benzodiazepine, midazolam, to explore the nature of the modality-match effect in implicit memory. We compared the modality-match effect in a midazolam and a saline (i.e., a placebo) condition. Our experimental results demonstrate that the modality-match effect is diminished substantially in a midazolam condition even though components of priming are preserved. Given the empirically-validated assumption that midazolam minimizes explicit memory, these results suggest that there exist components of implicit memory that are not mediated by perceptual processes and raise questions about the generality of prominent theories of implicit memory.

Adult↗
PubMed1999

Stereotypes and terror management: evidence that mortality salience enhances stereotypic thinking and preferences.

If stereotypes function to protect people against death-related concerns, then mortality salience should increase stereotypic thinking and preferences for stereotype-confirming individuals. Study 1 demonstrated that mortality salience increased stereotyping of Germans. In Study 2, it increased participants' tendency to generate more explanations for stereotype-inconsistent than stereotype-consistent gender role behavior. In Study 3, mortality salience increased participants' liking for a stereotype-consistent African American and decreased their liking for a stereotype-inconsistent African American; control participants exhibited the opposite preference. Study 4 replicated this pattern with evaluations of stereotype-confirming or stereotype-disconfirming men and women. Study 5 showed that, among participants high in need for closure, mortality salience led to decreased liking for a stereotype-inconsistent gay man.

Adult↗
PubMed1998

Terror management and aggression: evidence that mortality salience motivates aggression against worldview-threatening others.

The hypothesis that mortality salience (MS) motivates aggression against worldview-threatening others was tested in 4 studies. In Study 1, the experimenters induced participants to write about either their own death or a control topic, presented them with a target who either disparaged their political views or did not, and gave them the opportunity to choose the amount of hot sauce the target would have to consume. As predicted, MS participants allocated a particularly large amount of hot sauce to the worldview-threatening target. In Studies 2 and 3, the authors found that following MS induction, the opportunity to express a negative attitude toward the critical target eliminated aggression and the opportunity to aggress against the target eliminated derogation. This suggests that derogation and aggression are two alternative modes of responding to MS that serve the same psychological function. Finally, Study 4 showed that MS did not encourage aggression against a person who allocated unpleasant juice to the participant, supporting the specificity of MS-induced aggression to worldview-threatening others.

Adult↗
PubMed1998

Terror management and meaning: evidence that the opportunity to defend the worldview in response to mortality salience increases the meaningfulness of life in the mildly depressed.

Previous terror management research has demonstrated that mildly depressed participants show a greater increase in worldview defense in response to reminders of their mortality than do nondepressed participants. Because the cultural worldview is posited to provide a meaningful conception of life, we hypothesized that mildly depressed participants who defend their worldview in response to mortality salience (MS) would increase their perception that the world is meaningful. A preliminary study first examined the Kunzendorf No Meaning Scale as a measure to assess perceptions of meaning. In the primary study, mildly depressed and nondepressed participants contemplated their own mortality or a neutral topic, evaluated two targets in a manner that either allowed them to defend their worldview or that did not, and then completed the Kunzendorf No Meaning Scale. As predicted, mildly depressed participants who had the opportunity to defend their worldview in response to mortality salience reported greater meaning in life than did mildly depressed participants who did not have the opportunity to defend their worldview, or mildly depressed participants not exposed to mortality salience. Implications for understanding and treating depression are briefly discussed.

Adult↗
PubMed1997

Terror management and cognitive-experiential self-theory: evidence that terror management occurs in the experiential system.

The authors hypothesized, on the basis of terror management theory and cognitive-experiential self-theory, that participants in an experiential mode of thinking would respond to mortality salience with increased worldview defense and increased accessibility of death-related thoughts, whereas participants in a rational mode would not. Results from 3 studies provided convergent evidence that when participants were in an experiential mode, mortality salience produced the typical worldview defense effect, but when participants were in a rational mode it did not. Study 4 revealed that mortality salience also led to a delayed increase in the accessibility of death-related thoughts only when participants were in an experiential mode. These results supported the notion that worldwide defense is intensified only if individuals are in an experiential mode when considering their mortality. Discussion focuses on implications for understanding terror management processes.

Adaptation, Psychological↗
PubMed1997

Suppression, accessibility of death-related thoughts, and cultural worldview defense: exploring the psychodynamics of terror management.

Previous research has shown that after a mortality-salience (MS) treatment, death thought accessibility and worldview defense are initially low and then increase after a delay, suggesting that a person's initial response to conscious thoughts of mortality is to actively suppress death thoughts. If so, then high cognitive load, by disrupting suppression efforts, should lead to immediate increases in death thought accessibility and cultural worldview defense. Studies 1 and 2 supported this reasoning. Specifically, Study 1 replicated the delayed increase in death accessibility after MS among low cognitive load participants but showed a reversed pattern among participants under high cognitive load. Study 2 showed that, unlike low cognitive load participants, high cognitive load participants exhibited immediate increase in pro-American bias after MS. Study 3 demonstrated that worldview defense in response to MS reduces the delayed increase in death accessibility. Implications of these findings for understanding both terror management processes and psychological defense in general are discussed.

Affect↗
PubMed1997

Do low-risk prenatal patients really need a screening glucose challenge test?

BACKGROUND: It is common practice to routinely screen pregnant women for gestational diabetes. The screening technique typically used is the 1-hour 50-g oral glucose tolerance test (OGTT), with a subsequent 3-hour 100-g OGTT for women whose 1-hour test was positive. This process can be both time-consuming and inconvenient for patients. Additionally, its sensitivity and specificity are estimated to be 70% and 87% respectively, and data about the effect of screening and treatment on low-risk pregnancy outcomes are limited. The objective of this study was to reassess the value of routine screening of all pregnant patients with a 1-hour glucose challenge test. METHODS: At a university-based family practice center with a predominantly low-risk population, a retrospective analysis was performed of all patients (n = 595) who received prenatal care and gave birth between January 1988 and December 1993. Among women in whom gestational diabetes was diagnosed on the basis of glucose tolerance testing, we identified those with risk factors for the disease, and examined whether a selective screening program based on risk factors alone would have resulted in correct diagnoses of gestational diabetes. RESULTS: Of the 595 patients, 544 (91.4%) were screened with a 1-hour 50-g OGTT. This initial screening test was positive in 76 women (12.8%). Of these, 58 (76.3%) then had a 3-hour 100-g OGTT, and 13 received a diagnosis of gestational diabetes. Nine of these 13 women had risk factors for gestational diabetes. We determined that less than 1% of prenatal patients without risk factors for gestational diabetes were ultimately found to have gestational diabetes. CONCLUSIONS: Screening with a 1-hour 50-g OGTT only those women who have identifiable risk factors for gestational diabetes is a reasonable approach to identifying the disease in a low-risk population. All pregnant women should have a thorough history taken to determine whether they have risk factors for gestational diabetes.

Adolescent↗
PubMed1994

Therapeutic efficacy and tolerability of brodimoprim in comparison with doxycycline in acute sinusitis in adults.

OBJECTIVE: To compare efficacy and tolerability of brodimoprim tablets with doxycycline tablets in adults with acute sinusitis. DESIGN: Open, randomized, controlled phase III study, with parallel groups. PATIENTS: Of the 70 enrolled patients, 56 adults of both sexes with a mean age of 33 years were evaluable. STUDY DRUGS: One brodimoprim 200mg tablet or one doxycycline 100mg tablet was administered once daily for 8 to 12 days (on the first treatment day all patients received the loading dose consisting of 2 tablets of the corresponding compound). CLINICAL OUTCOME: In the brodimoprim group 96.4% of the patients were judged cured/improved; in the doxycycline group 96.2%. BACTERIOLOGICAL OUTCOME: Eradication of the causative pathogen/s was achieved in 87.5% of the patients treated with brodimoprim and in 60% of the doxycycline group. SAFETY OUTCOME: Tolerability was judged as very good/good in 89.7% of the patients treated with brodimoprim and in all patients receiving doxycycline. Gastrointestinal skin, CNS and various other reactions were reported by 13 patients; 3 of them had to discontinue treatment. Discontinuation of therapy: 8 more patients withdrew from the study due to inactivity of the compound or reasons unrelated to the drugs. CONCLUSION: Brodimoprim was shown to be effective in the treatment of acute sinusitis in adults, its efficacy being equal to that of doxycycline. The assessments showed a positive clinical response to the medication in 96.4% of the patients treated with brodimoprim and 96.2% of the patients taking doxycycline. Both compounds were well tolerated and all side effects were of mild nature and reversible.

Acute Disease↗
PubMed1992

Three-dimensional dose mapping from gamma knife treatment using a dosimeter gel and MR-imaging.

A new method has been investigated for the mapping of dose distributions in three dimensions delivered by the Leksell gamma knife. The irradiation unit is used to selectively treat small volumes in the brain with single high doses of ionising radiation--a treatment procedure known as radiosurgery. The dosimetry method investigated utilises a dosimeter gel consisting of ferrous sulphate solution and agarose which is, prior to irradiation, loaded into a cavity in a spherical phantom. Chemical changes induced in the gel by the radiation are measured by means of an MR-scanner. This imaging method permits rapid evaluation of the dose distribution in an irradiated volume. It thus offers a potential verification of individual radiation intracranial target treatment regimes as well as quality assurance measurements, assuming that the precision and accuracy of the dose mapping are adequate. The dose and its distribution registered by the gel dosimeter, in this initial experiment, are in good agreement with corresponding computed data obtained with the KULA treatment planning system of the gamma knife. The gel has thus the potential of being an attractive alternative dose mapping method to those used at present in radiosurgery, i.e. radiographic film and small ionisation chambers. The precision of the dosimeter gel is, however, not yet sufficient high to be used as a basic dosimetry system for the gamma knife.

Gels↗
PubMed1990

Evidence for the induction of protease activity on cultured tumour cells as a consequence of implantation into nude mice.

We have studied the enzymic status of a tumour associated protease on human colonic tumour cells cultured in vitro and grown in vivo in nude mice. The cultured tumour cells lack this protease. The cells of the tumour colonies in the mice possess active enzyme although the tissue contains an inhibitor capable of inactivating this tumour cell protease. The evidence indicates that the induction of this protease on the tumour cells is a consequence of implantation of the cultured cells into the nude mouse.

Aminacrine↗