Effects of Dispatcher-assisted Cardiopulmonary Resuscitation on Survival Outcomes in Infants, Children, and Adolescents with Out-of-hospital Cardiac Arrests.

PubMed

Ro, Young Sun; Shin, Sang Do; Song, Kyoung Jun; Hong, Ki Jeong; Ahn, Ki Ok; Kim, Do Kyun; Kwak, Young Ho

2016-11-01

We studied the effect of a dispatcher-assisted cardiopulmonary resuscitation (CPR) program on paediatric out-of-hospital cardiac arrest (OHCA) outcomes by age groups. All emergency medical services (EMS)-treated paediatric OHCAs in Korea were enrolled between 2012 and 2014, excluding cases witnessed by EMS providers and those with unknown outcomes. The cases were divided into three groups: bystander CPR with dispatcher assistance, bystander CPR without dispatcher assistance, and no-bystander CPR. The endpoint was survival until discharge from hospital. Multivariable logistic regression analysis was performed. The final model with an interaction term was evaluated to compare the effects across age groups. A total of 1529 patients (32.8% bystander CPR with dispatcher assistance, 17.3% without dispatcher assistance, and 54.6% no-bystander CPR) were included. Both bystander CPR groups were more likely to have higher rate of survival to discharge (8.8% and 12.1%) compared to no-bystander CPR (3.9%). The adjusted OR (95% CI) for survival to discharge were 1.77 (1.04-3.00) in bystander CPR with dispatcher assistance and 2.86 (1.61-5.08) in without dispatcher assistance compared with no-bystander CPR. By age groups, the adjusted OR (95% CI) in bystander CPR with and without dispatcher assistance were 2.18 (1.07-4.42) and 2.27 (1.01-5.14) for the group aged 9-18 years; 2.32 (0.64-8.44) and 6.21 (1.83-21.01) for the group aged 1-8 years; 1.06 (0.41-2.77) and 2.00 (0.64-6.18) for the group aged 0-12 months, respectively. Bystander CPR, regardless of dispatcher assistance, was associated with improved survival outcomes after OHCA in the paediatric population. However, the associations between dispatcher-assisted bystander CPR and survival outcomes varied by age. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Low Doses of Gamma-Irradiation Induce an Early Bystander Effect in Zebrafish Cells Which Is Sufficient to Radioprotect Cells

PubMed Central

Pereira, Sandrine; Malard, Véronique; Ravanat, Jean-Luc; Davin, Anne-Hélène; Armengaud, Jean; Foray, Nicolas; Adam-Guillermin, Christelle

2014-01-01

The term “bystander effect” is used to describe an effect in which cells that have not been exposed to radiation are affected by irradiated cells though various intracellular signaling mechanisms. In this study we analyzed the kinetics and mechanisms of bystander effect and radioadaptation in embryonic zebrafish cells (ZF4) exposed to chronic low dose of gamma rays. ZF4 cells were irradiated for 4 hours with total doses of gamma irradiation ranging from 0.01–0.1 Gy. In two experimental conditions, the transfer of irradiated cells or culture medium from irradiated cells results in the occurrence of DNA double strand breaks in non-irradiated cells (assessed by the number of γ-H2AX foci) that are repaired at 24 hours post-irradiation whatever the dose. At low total irradiation doses the bystander effect observed does not affect DNA repair mechanisms in targeted and bystander cells. An increase in global methylation of ZF4 cells was observed in irradiated cells and bystander cells compared to control cells. We observed that pre-irradiated cells which are then irradiated for a second time with the same doses contained significantly less γ-H2AX foci than in 24 h gamma-irradiated control cells. We also showed that bystander cells that have been in contact with the pre-irradiated cells and then irradiated alone present less γ-H2AX foci compared to the control cells. This radioadaptation effect is significantly more pronounced at the highest doses. To determine the factors involved in the early events of the bystander effect, we performed an extensive comparative proteomic study of the ZF4 secretomes upon irradiation. In the experimental conditions assayed here, we showed that the early events of bystander effect are probably not due to the secretion of specific proteins neither the oxidation of these secreted proteins. These results suggest that early bystander effect may be due probably to a combination of multiple factors. PMID:24667817

Getting angry matters: Going beyond perspective taking and empathic concern to understand bystanders' behavior in bullying.

PubMed

Pozzoli, Tiziana; Gini, Gianluca; Thornberg, Robert

2017-12-01

The present study examined the relations between different empathic dimensions and bystanders' behavior in bullying. Specifically, the indirect effects of empathic concern and perspective taking via empathic anger on defending and passive bystanding were tested in a sample of Italian young adolescents (N = 398; M age  = 12 years, 3 months, 47.2% girls). Path analysis confirmed the direct and indirect effects, via empathic anger, of empathic concern and perspective taking on bystanders' behavior, with the exception of the direct association between perspective taking and passive bystanding that was not significant. Our findings suggest that considering empathic anger together with empathic concern and perspective taking could help researchers to better understand the links between empathic dispositions and bystanders' behavior in bullying. Copyright © 2017. Published by Elsevier Ltd.

Radionuclides in radiation-induced bystander effect; may it share in radionuclide therapy?

PubMed

Widel, M

2017-01-01

For many years in radiobiology and radiotherapy predominated the conviction that cellular DNA is the main target for ionizing radiation, however, the view has changed in the past 20 years. Nowadays, it is assumed that not only directed (targeted) radiation effect, but also an indirect (non-targeted) effect may contribute to the result of radiation treatment. Non-targeted effect is relatively well recognized after external beam irradiation in vitro and in vivo, and comprises such phenomena like radiation-induced bystander effect (RIBE), genomic instability, adaptive response and abscopal (out of field) effect. These stress-induced and molecular signaling mediated phenomena appear in non-targeted cells as variety responses resembling that observed in directly hit cells. Bystander effects can be both detrimental and beneficial in dependence on dose, dose-rate, cell type, genetic status and experimental condition. Less is known about radionuclide-induced non-targeted effects in radionuclide therapy, although, based on characteristics of the radionuclide radiation, on experiments in vitro utilizing classical and 3-D cell cultures, and preclinical study on animals it seems obvious that exposure to radionuclide is accompanied by various bystander effects, mostly damaging, less often protective. This review summarizes existing data on radionuclide induced bystander effects comprising radionuclides emitting beta- and alpha-particles and Auger electrons used in tumor radiotherapy and diagnostics. So far, separation of the direct effect of radionuclide decay from crossfire and bystander effects in clinical targeted radionuclide therapy is impossible because of the lack of methods to assess whether, and to what extent bystander effect is involved in human organism. Considerations on this topic are also included.

The Bystander-Effect: A Meta-Analytic Review on Bystander Intervention in Dangerous and Non-Dangerous Emergencies

ERIC Educational Resources Information Center

Fischer, Peter; Krueger, Joachim I.; Greitemeyer, Tobias; Vogrincic, Claudia; Kastenmuller, Andreas; Frey, Dieter; Heene, Moritz; Wicher, Magdalena; Kainbacher, Martina

2011-01-01

Research on bystander intervention has produced a great number of studies showing that the presence of other people in a critical situation reduces the likelihood that an individual will help. As the last systematic review of bystander research was published in 1981 and was not a quantitative meta-analysis in the modern sense, the present…

Predicting Improvement After a Bystander Program for the Prevention of Sexual and Dating Violence.

PubMed

Hines, Denise A; Palm Reed, Kathleen M

2015-07-01

Although evidence suggests that bystander prevention programs are promising interventions for decreasing sexual violence and dating violence on college campuses, there have been no studies to date evaluating moderators of bystander program effectiveness. The current study evaluates whether different demographic characteristics, attitudes, knowledge, and behaviors at pretest predict change over a 6-month follow-up for students who participated in a bystander prevention program. Participants in the three assessments (pretest, posttest, 6-month follow-up) included 296 college students who were mandated to attend a bystander program during their first year orientation. Analyses showed that with few exceptions, the bystander program worked best for students who were most at risk given their pretest demographics and levels of attitudes condoning dating violence and sexual violence, bystander efficacy, and bystander behaviors. Results are discussed in terms of suggestions for future research. © 2014 Society for Public Health Education.

The positive bystander effect: passive bystanders increase helping in situations with high expected negative consequences for the helper.

PubMed

Fischer, Peter; Greitemeyer, Tobias

2013-01-01

The present field study investigated the interplay between the presence of a passive bystander (not present versus present) in a simulated bike theft and expected negative consequences (low versus high) in predicting intervention behavior when no physical victim is present. It was found that an additional bystander increases individual intervention in situations where the expected negative consequences for the helper in case of intervention were high (i.e., when the bike thief looks fierce) compared to situations where the expected negative consequences for the helper were low (i.e., when the bike thief does not look fierce). In contrast, no such effect for high vs. low expected negative consequences was observed when no additional bystander observed the critical situation. The results are discussed in light of previous laboratory findings on expected negative consequences and bystander intervention.

Chemotherapy-induced bystander effect in response to several chloroethylnitrosoureas: an origin independent of DNA damage?

PubMed

Merle, Patrick; Morvan, Daniel; Caillaud, Denis; Demidem, Aicha

2008-01-01

Chloroethylnitrosourea (CENU) chemotherapy is used for the treatment of melanoma tumors. The main mechanism of action of this anticancer agent is via DNA damage. We recently showed in murine experiments using a parental double B16 melanoma tumor model that, after treatment of primary tumors with cystemustine (CENU agent), untreated secondary tumors exhibited growth inhibition and metabolism disorders. The response of secondary untreated tumor was called the chemotherapy-induced bystander effect. To see whether chemotherapy-induced bystander effects were induced with other members of the CENU family, we compared three CENU(s) used in melanoma treatment: cystemustine, carmustine and fotemustine. Our results demonstrate that fotemustine, like cystemustine, but not carmustine induced a protective effect against secondary untreated tumors including alterations in phospholipid derivative and glutathione which are the metabolic signature of the bystander effect. From these data we may conclude that DNA damage to the primary tumor is not sufficient to explain chemotherapy-induced bystander effects.

Improved Anticancer Photothermal Therapy Using the Bystander Effect Enhanced by Antiarrhythmic Peptide Conjugated Dopamine-Modified Reduced Graphene Oxide Nanocomposite.

PubMed

Yu, Jiantao; Lin, Yu-Hsin; Yang, Lingyan; Huang, Chih-Ching; Chen, Liliang; Wang, Wen-Cheng; Chen, Guan-Wen; Yan, Junyan; Sawettanun, Saranta; Lin, Chia-Hua

2017-01-01

Despite tremendous efforts toward developing novel near-infrared (NIR)-absorbing nanomaterials, improvement in therapeutic efficiency remains a formidable challenge in photothermal cancer therapy. This study aims to synthesize a specific peptide conjugated polydopamine-modified reduced graphene oxide (pDA/rGO) nanocomposite that promotes the bystander effect to facilitate cancer treatment using NIR-activated photothermal therapy. To prepare a nanoplatform capable of promoting the bystander effect in cancer cells, we immobilized antiarrhythmic peptide 10 (AAP10) on the surface of dopamine-modified rGO (AAP10-pDA/rGO). Our AAP10-pDA/rGO could promote the bystander effect by increasing the expression of connexin 43 protein in MCF-7 breast-cancer cells. Because of its tremendous ability to absorb NIR absorption, AAP10-pDA/rGO offers a high photothermal effect under NIR irradiation. This leads to a massive death of MCF-7 cells via the bystander effect. Using tumor-bearing mice as the model, it is found that NIR radiation effectively ablates breast tumor in the presence of AAP10-pDA/rGO and inhibits tumor growth by ≈100%. Therefore, this research integrates the bystander and photothermal effects into a single nanoplatform in order to facilitate an efficient photothermal therapy. Furthermore, our AAP10-pDA/rGO, which exhibits both hyperthermia and the bystander effect, can prevent breast-cancer recurrence and, therefore, has great potential for future clinical and research applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Neutron Exposures in Human Cells: Bystander Effect and Relative Biological Effectiveness

PubMed Central

Seth, Isheeta; Schwartz, Jeffrey L.; Stewart, Robert D.; Emery, Robert; Joiner, Michael C.; Tucker, James D.

2014-01-01

Bystander effects have been observed repeatedly in mammalian cells following photon and alpha particle irradiation. However, few studies have been performed to investigate bystander effects arising from neutron irradiation. Here we asked whether neutrons also induce a bystander effect in two normal human lymphoblastoid cell lines. These cells were exposed to fast neutrons produced by targeting a near-monoenergetic 50.5 MeV proton beam at a Be target (17 MeV average neutron energy), and irradiated-cell conditioned media (ICCM) was transferred to unirradiated cells. The cytokinesis-block micronucleus assay was used to quantify genetic damage in radiation-naïve cells exposed to ICCM from cultures that received 0 (control), 0.5, 1, 1.5, 2, 3 or 4 Gy neutrons. Cells grown in ICCM from irradiated cells showed no significant increase in the frequencies of micronuclei or nucleoplasmic bridges compared to cells grown in ICCM from sham irradiated cells for either cell line. However, the neutron beam has a photon dose-contamination of 5%, which may modulate a neutron-induced bystander effect. To determine whether these low doses of contaminating photons can induce a bystander effect, cells were irradiated with cobalt-60 at doses equivalent to the percent contamination for each neutron dose. No significant increase in the frequencies of micronuclei or bridges was observed at these doses of photons for either cell line when cultured in ICCM. As expected, high doses of photons induced a clear bystander effect in both cell lines for micronuclei and bridges (p<0.0001). These data indicate that neutrons do not induce a bystander effect in these cells. Finally, neutrons had a relative biological effectiveness of 2.0±0.13 for micronuclei and 5.8±2.9 for bridges compared to cobalt-60. These results may be relevant to radiation therapy with fast neutrons and for regulatory agencies setting standards for neutron radiation protection and safety. PMID:24896095

Neutron exposures in human cells: bystander effect and relative biological effectiveness.

PubMed

Seth, Isheeta; Schwartz, Jeffrey L; Stewart, Robert D; Emery, Robert; Joiner, Michael C; Tucker, James D

2014-01-01

Bystander effects have been observed repeatedly in mammalian cells following photon and alpha particle irradiation. However, few studies have been performed to investigate bystander effects arising from neutron irradiation. Here we asked whether neutrons also induce a bystander effect in two normal human lymphoblastoid cell lines. These cells were exposed to fast neutrons produced by targeting a near-monoenergetic 50.5 MeV proton beam at a Be target (17 MeV average neutron energy), and irradiated-cell conditioned media (ICCM) was transferred to unirradiated cells. The cytokinesis-block micronucleus assay was used to quantify genetic damage in radiation-naïve cells exposed to ICCM from cultures that received 0 (control), 0.5, 1, 1.5, 2, 3 or 4 Gy neutrons. Cells grown in ICCM from irradiated cells showed no significant increase in the frequencies of micronuclei or nucleoplasmic bridges compared to cells grown in ICCM from sham irradiated cells for either cell line. However, the neutron beam has a photon dose-contamination of 5%, which may modulate a neutron-induced bystander effect. To determine whether these low doses of contaminating photons can induce a bystander effect, cells were irradiated with cobalt-60 at doses equivalent to the percent contamination for each neutron dose. No significant increase in the frequencies of micronuclei or bridges was observed at these doses of photons for either cell line when cultured in ICCM. As expected, high doses of photons induced a clear bystander effect in both cell lines for micronuclei and bridges (p<0.0001). These data indicate that neutrons do not induce a bystander effect in these cells. Finally, neutrons had a relative biological effectiveness of 2.0 ± 0.13 for micronuclei and 5.8 ± 2.9 for bridges compared to cobalt-60. These results may be relevant to radiation therapy with fast neutrons and for regulatory agencies setting standards for neutron radiation protection and safety.

A correlation of long term effects and radiation quality in the progeny of bystander cells after microbeam radiations: The experimental study of radiotherapy for cancer risk mitigation

NASA Astrophysics Data System (ADS)

Autsavapromporn, N.; Konishi, T.; Liu, C.; Plante, I.; Funayama, T.; Usami, N.; Azzam, EI; Suzuki, M.

2017-06-01

The goal of this study is to investigate the role of radiation quality and gap junction intercellular communication (GJIC) in the propagation of delayed stressful effects in the progeny of bystander human skin fibroblasts cultures (NB1RGB). Briefly, confluent NB1RGB cells in the presence and absence of gap junction inhibitor (AGA) were exposed to ionizing radiation (IR) with a different linear energy transfer (LET) either 5.35 keV X rays (LET ∼6 keV/μm) or 18.3 MeV/u carbon (LET ∼103 keV/μm) microbeam radiations. Following 20 populations post-irradiation, the progeny of bystander NB1RGB cells were harvested and assayed for several of biological endpoints. Our results showed that expression of stressful effects in the progeny of bystander cells is dependent on LET. The progeny of bystander cells exposed to low-LET X rays showed the persistence of oxidative stress and it was correlated with the increased mutant fraction. Such effect were not observed after high-LET carbon ions. Interestingly, inhibition of GJIC mitigated the toxic effects in the progeny of bystander cells. Together, the results contribute to the understanding of the fundamental radiation biology relating to the high-LET carbon ions to mitigate cancer risk after radiotherapy. Furthermore, GJIC be considered as a critical mediator in the bystander mutagenic effect.

Raising a Red Flag on Dating Violence: Evaluation of a Low-Resource, College-Based Bystander Behavior Intervention Program.

PubMed

Borsky, Amanda E; McDonnell, Karen; Turner, Monique Mitchell; Rimal, Rajiv

2016-03-09

Encouraging bystanders to intervene safely and effectively in situations that could escalate to violence-known as bystander behavior programs-is a growing yet largely untested strategy to prevent dating violence. Using a quasi-experimental design, we evaluate a low-resource, low-intensity intervention aimed at preventing dating violence among college students. The integrated behavioral model (IBM) was used to guide the evaluation. We also assess which IBM variables were most strongly associated with bystander behaviors. Participants were drawn from two Virginia colleges that predominantly train females in the health profession sciences. The intervention group (n = 329) participated in a university-wide bystander behavior intervention consisting of a 30-min presentation on dating violence at new-student orientation and a week-long "red flag" social marketing campaign on campus to raise awareness of dating violence. Controlling for changes at the comparison university, results showed an increase in bystander behaviors, such as encouraging a friend who may be in an abusive relationship to get help, after the intervention and adjusting for potential confounders (increase of 1.41 bystander behaviors, p = .04). However, no significant changes were found for bystander intentions, self-efficacy, social norms, or attitudes related to dating violence from pre- to post-intervention. Self-efficacy had a direct relationship with bystander behaviors. Results suggest that low-resource interventions have a modest effect on increasing bystander behaviors. However, higher resource interventions likely are needed for a larger impact, especially among students who already demonstrate strong baseline intentions to intervene and prevent dating violence. © The Author(s) 2016.

Student Voices: What Can Bystanders Do to Prevent Bullying of Students Who Are Different (or Perceived as Different) from Others?

ERIC Educational Resources Information Center

Nordseth, Anna; Vepachedu, Vikas; Shipman, Grant; Alayachew, David

2012-01-01

In this article, four students share their ideas on what bystanders can do to prevent bullying of students who are different or perceived as different from others. Anna Nordseth says what bystanders need to realize is how to recognize bullying and what a lasting effect it can have on the individuals involved. One bold, compassionate bystander can…

Real behavior in virtual environments: psychology experiments in a simple virtual-reality paradigm using video games.

PubMed

Kozlov, Michail D; Johansen, Mark K

2010-12-01

The purpose of this research was to illustrate the broad usefulness of simple video-game-based virtual environments (VEs) for psychological research on real-world behavior. To this end, this research explored several high-level social phenomena in a simple, inexpensive computer-game environment: the reduced likelihood of helping under time pressure and the bystander effect, which is reduced helping in the presence of bystanders. In the first experiment, participants had to find the exit in a virtual labyrinth under either high or low time pressure. They encountered rooms with and without virtual bystanders, and in each room, a virtual person requested assistance. Participants helped significantly less frequently under time pressure but the presence/absence of a small number of bystanders did not significantly moderate helping. The second experiment increased the number of virtual bystanders, and participants were instructed to imagine that these were real people. Participants helped significantly less in rooms with large numbers of bystanders compared to rooms with no bystanders, thus demonstrating a bystander effect. These results indicate that even sophisticated high-level social behaviors can be observed and experimentally manipulated in simple VEs, thus implying the broad usefulness of this paradigm in psychological research as a good compromise between experimental control and ecological validity.

Booze, Bars, and Bystander Behavior: People Who Consumed Alcohol Help Faster in the Presence of Others

PubMed Central

van Bommel, Marco; van Prooijen, Jan-Willem; Elffers, Henk; Van Lange, Paul A. M.

2016-01-01

People help each other less often and less quickly when bystanders are present. In this paper, we propose that alcohol consumption could attenuate or reverse this so-called bystander effect. Alcohol impairs people cognitively and perceptually, leading them to think less about the presence of others and behave less inhibited. Moreover, alcohol makes people more prone to see the benefits of helping and not the costs. To provide an initial test of these lines of reasoning, we invited visitors of bars in Amsterdam to join our study at a secluded spot at the bar. We manipulated bystander presence, and at the end of the study, we measured alcohol consumption. When participants took their seats, the experimenter dropped some items. We measured how many items were picked up and how quickly participants engaged in helping. Results revealed that alcohol did not influence the bystander effect in terms of the amount of help given. But importantly, it did influence the bystander effect in terms of response times: people who consumed alcohol actually came to aid faster in the presence of others. PMID:26903929

Epigenetic Analysis of Heavy-ion Radiation Induced Bystander Effects in Mice

NASA Astrophysics Data System (ADS)

Zhang, Meng; Sun, Yeqing; Cui, Changna; Xue, Bei

Abstract: Radiation-induced bystander effect was defined as the induction of damage in neighboring non-hit cells by signals released from directly-irradiated cells. Recently, low dose of high LET radiation induced bystander effects in vivo have been reported more and more. It has been indicated that radiation induced bystander effect was localized not only in bystander tissues but also in distant organs. Genomic, epigenetic and proteomics plays significant roles in regulating heavy-ion radiation stress responses in mice. To identify the molecular mechanism that underlies bystander effects of heavy-ion radiation, the male Balb/c and C57BL mice were exposed head-only to 40, 200, 2000mGy dose of (12) C heavy-ion radiation, while the rest of the animal body was shielded. Directly radiation organ ear and the distant organ liver were detected on 1h, 6h, 12h and 24h after radiation, respectively. Methylation-sensitive amplification polymorphism (MSAP) was used to monitor the level of polymorphic genomic DNA methylation changed with dose and time effects. The results show that heavy-ion irradiated mouse head could induce genomic DNA methylation changes significantly in both the directly radiation organ ear and the distant organ liver. The percent of DNA methylation changes were time-dependent and tissue-specific. Demethylation polymorphism rate was highest separately at 1 h in 200 mGy and 6 h in 2000 mGy after irradiation. The global DNA methylation changes tended to occur in the CG sites. The results illustrated that genomic methylation changes of heavy ion radiation-induced bystander effect in liver could be obvious 1 h after radiation and achieved the maximum at 6 h, while the changes could recover gradually at 12 h. The results suggest that mice head exposed to heavy-ion radiation can induce damage and methylation pattern changed in both directly radiation organ ear and distant organ liver. Moreover, our findings are important to understand the molecular mechanism of radiation induced bystander effects in vivo.

Recursive mentalizing and common knowledge in the bystander effect.

PubMed

Thomas, Kyle A; De Freitas, Julian; DeScioli, Peter; Pinker, Steven

2016-05-01

The more potential helpers there are, the less likely any individual is to help. A traditional explanation for this bystander effect is that responsibility diffuses across the multiple bystanders, diluting the responsibility of each. We investigate an alternative, which combines the volunteer's dilemma (each bystander is best off if another responds) with recursive theory of mind (each infers what the others know about what he knows) to predict that actors will strategically shirk when they think others feel compelled to help. In 3 experiments, participants responded to a (fictional) person who needed help from at least 1 volunteer. Participants were in groups of 2 or 5 and had varying information about whether other group members knew that help was needed. As predicted, people's decision to help zigzagged with the depth of their asymmetric, recursive knowledge (e.g., "John knows that Michael knows that John knows help is needed"), and replicated the classic bystander effect when they had common knowledge (everyone knowing what everyone knows). The results demonstrate that the bystander effect may result not from a mere diffusion of responsibility but specifically from actors' strategic computations. (c) 2016 APA, all rights reserved).

Beta1-integrin and IL-1alpha expression as bystander effect of medium from irradiated cells: the pilot study.

PubMed

Osterreicher, Jan; Skopek, Jirí; Jahns, Juta; Hildebrandt, Guido; Psutka, Jan; Vilasová, Zdenka; Tanner, Judith Maria; Vogt, Jürgen; Butz, Tilman

2003-01-01

Bystander effects have been proposed as a third action pathway of ionising radiation besides direct and indirect effects. The purpose of the study was to investigate whether expression of interleukin-1alpha (IL-1alpha) and beta1-integrin is elevated in bystander cells as a marker for bystander effects in comparison with classical markers such as the clonogenic assay, apoptosis and the presence of micronuclei. The hybrid cell line E.A. hy.926 obtained by fusion of HUVEC cells with the epithelial cell line A 459 was irradiated with 0-5 Gy. Bystander effects were established via medium transfer at 45 min and 4 h after irradiation from irradiated to nonirradiated cell populations. In order to exclude effects of the irradiated medium itself, irradiated medium only was also used for transfer to nonirradiated cells. Then, cells were fixed at 1, 2, 6, and 24 h after irradiation or medium transport and IL-1alpha and beta1-integrin were detected and evaluated. A higher number of beta1-integrin-positive cells was observed in both irradiated and bystander cell populations than in the control group at 1 and 24 h after irradiation with 1 Gy or medium transfer. Significantly higher numbers of IL-1alpha-positive cells were found at 1, 2, and 6 h after irradiation with 1 Gy or medium transfer as well as at 2 and 6 h after irradiation with 5 Gy or medium transfer. Clonogenic survival decreased dependently on the dose in irradiated cells but did not show any significant difference between the bystander cell populations and sham-irradiated cells. The irradiated medium itself did not have any effect. It is concluded that beta1-integrin and IL-1alpha expression may serve as more sensitive markers of post-irradiation responses in bystander cell populations than the classical radiobiological markers. Moreover, overexpression of beta1-integrin and IL-1alpha may induce increased susceptibility to inflammation of bystander cells.

Factors associated with bystander behaviors of Korean youth in school bullying situations: A cross-sectional study.

PubMed

Yang, Seung Ae; Kim, Dong Hee

2017-08-01

The behaviors of bystanders can have important effects on their peers. The aim of this study was to identify psychosocial and contextual factors associated with 3 types of bystander behavior (bully followers, outsiders, and defenders of victims) among Korean youth. A descriptive and cross-sectional study was conducted among 416 7th and 8th-grade students from 1 middle school in Korea. The Rosenberg Self Esteem Scale, the Korean version of the Social Problem-Solving Inventory, and measurements of relationships with friends and teachers, empathy, concerns about being bullied, attitudes toward bullying, and bystander behaviors were all used in the assessment. Empathy, relationship of teachers, attitudes toward bullying, and concerns about being bullied were significantly associated with all 3 types of bystanders' behaviors. Although, self-esteem, social problem solving ability were significantly associated with just defender of victim behaviors. These results suggest that several significant factors to cultivate constructive bystander behaviors should be considered to develop effective antibullying intervention.

Critical role of gap junction communication, calcium and nitric oxide signaling in bystander responses to focal photodynamic injury.

PubMed

Calì, Bianca; Ceolin, Stefano; Ceriani, Federico; Bortolozzi, Mario; Agnellini, Andrielly H R; Zorzi, Veronica; Predonzani, Andrea; Bronte, Vincenzo; Molon, Barbara; Mammano, Fabio

2015-04-30

Ionizing and nonionizing radiation affect not only directly targeted cells but also surrounding "bystander" cells. The underlying mechanisms and therapeutic role of bystander responses remain incompletely defined. Here we show that photosentizer activation in a single cell triggers apoptosis in bystander cancer cells, which are electrically coupled by gap junction channels and support the propagation of a Ca2+ wave initiated in the irradiated cell. The latter also acts as source of nitric oxide (NO) that diffuses to bystander cells, in which NO levels are further increased by a mechanism compatible with Ca(2+)-dependent enzymatic production. We detected similar signals in tumors grown in dorsal skinfold chambers applied to live mice. Pharmacological blockade of connexin channels significantly reduced the extent of apoptosis in bystander cells, consistent with a critical role played by intercellular communication, Ca2+ and NO in the bystander effects triggered by photodynamic therapy.

X-ray-induced bystander responses reduce spontaneous mutations in V79 cells

PubMed Central

Maeda, Munetoshi; Kobayashi, Katsumi; Matsumoto, Hideki; Usami, Noriko; Tomita, Masanori

2013-01-01

The potential for carcinogenic risks is increased by radiation-induced bystander responses; these responses are the biological effects in unirradiated cells that receive signals from the neighboring irradiated cells. Bystander responses have attracted attention in modern radiobiology because they are characterized by non-linear responses to low-dose radiation. We used a synchrotron X-ray microbeam irradiation system developed at the Photon Factory, High Energy Accelerator Research Organization, KEK, and showed that nitric oxide (NO)-mediated bystander cell death increased biphasically in a dose-dependent manner. Here, we irradiated five cell nuclei using 10 × 10 µm2 5.35 keV X-ray beams and then measured the mutation frequency at the hypoxanthine-guanosine phosphoribosyl transferase (HPRT) locus in bystander cells. The mutation frequency with the null radiation dose was 2.6 × 10–5 (background level), and the frequency decreased to 5.3 × 10–6 with a dose of approximately 1 Gy (absorbed dose in the nucleus of irradiated cells). At high doses, the mutation frequency returned to the background level. A similar biphasic dose-response effect was observed for bystander cell death. Furthermore, we found that incubation with 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO), a specific scavenger of NO, suppressed not only the biphasic increase in bystander cell death but also the biphasic reduction in mutation frequency of bystander cells. These results indicate that the increase in bystander cell death involves mechanisms that suppress mutagenesis. This study has thus shown that radiation-induced bystander responses could affect processes that protect the cell against naturally occurring alterations such as mutations. PMID:23660275

A High School-Based Evaluation of TakeCARE, a Video Bystander Program to Prevent Adolescent Relationship Violence.

PubMed

Sargent, Kelli S; Jouriles, Ernest N; Rosenfield, David; McDonald, Renee

2017-03-01

Although bystander programs to prevent relationship and sexual violence have been evaluated with college students, few evaluations have been conducted with high school students. This study evaluated the effectiveness of TakeCARE, a brief video bystander program designed to promote helpful bystander behavior in situations involving relationship violence among high school students. Students (N = 1295; 52.5% female; 72.3% Hispanic) reported their bystander behavior at a baseline assessment. Classrooms (N = 66) were randomized to view TakeCARE or to a control condition, and high school counselors administered the video in the classrooms assigned to view TakeCARE. Students again reported their bystander behavior at a follow-up assessment approximately 3 months afterward. Results indicate that students who viewed TakeCARE reported more helpful bystander behavior at the follow-up assessment than students in the control condition. Results of exploratory analyses of the likelihood of encountering and intervening upon specific situations calling for bystander behavior are also reported. TakeCARE is efficacious when implemented in an urban high school by high school counselors.

An Evaluation of Two Dating Violence Prevention Programs on a College Campus.

PubMed

Peterson, Kerry; Sharps, Phyllis; Banyard, Victoria; Powers, Ráchael A; Kaukinen, Catherine; Gross, Deborah; Decker, Michele R; Baatz, Carrie; Campbell, Jacquelyn

2016-03-13

Dating violence is a serious and prevalent public health problem that is associated with numerous negative physical and psychological health outcomes, and yet there has been limited evaluation of prevention programs on college campuses. A recent innovation in campus prevention focuses on mobilizing bystanders to take action. To date, bystander programs have mainly been compared with no treatment control groups raising questions about what value is added to dating violence prevention by focusing on bystanders. This study compared a single 90-min bystander education program for dating violence prevention with a traditional awareness education program, as well as with a no education control group. Using a quasi-experimental pre-test/post-test design with follow-up at 2 months, a sample of predominately freshmen college students was randomized to either the bystander (n = 369) or traditional awareness (n = 376) dating violence education program. A non-randomized control group of freshmen students who did not receive any education were also surveyed (n = 224). Students completed measures of attitudes, including rape myth acceptance, bystander efficacy, and intent to help as well as behavioral measures related to bystander action and victimization. Results showed that the bystander education program was more effective at changing attitudes, beliefs, efficacy, intentions, and self-reported behaviors compared with the traditional awareness education program. Both programs were significantly more effective than no education. The findings of this study have important implications for future dating violence prevention educational programming, emphasizing the value of bystander education programs for primary dating violence prevention among college students. © The Author(s) 2016.

The Role of DNA Methylation Changes in Radiation-Induced Bystander Effects in cranial irradiated Mice

NASA Astrophysics Data System (ADS)

Zhang, Meng; Sun, Yeqing; Xue, Bei; Wang, Xinwen; Wang, Jiawen

2016-07-01

Heavy-ion radiation could lead to bystander effect in neighboring non-hit cells by signals released from directly-irradiated cells. The exact mechanisms of radiation-induced bystander effect in distant organ remain obscure, yet accumulating evidence points to the role of DNA methylation changes in bystander effect. To identify the molecular mechanism that underlies bystander effects of heavy-ion radiation, the male Balb/c and C57BL mice were cranial exposed to 40, 200, 2000mGy dose of carbon heavy-ion radiation, while the rest of the animal body was shielded. The γH2AX foci as the DNA damage biomarker in directly irradiation organ ear and the distant organ liver were detected on 0, 1, 2, 6, 12 and 24h after radiation, respectively. Methylation-sensitive amplifcation polymorphism (MSAP) was used to monitor the level of polymorphic genomic DNA methylation changed with dose and time effects. The results show that cranial irradiated mice could induce the γH2AX foci and genomic DNA methylation changes significantly in both the directly irradiation organ ear and the distant organ liver. The percent of DNA methylation changes were time-dependent and tissue-specific. Demethylation polymorphism rate were highest separately at 1 h in 200 mGy and 6 h in 2000 mGy after irradiation in ear. The global DNA methylation changes tended to occur in the CG sites. We also found that the numbers of γH2AX foci and the genomic methylation changes of heavy-ion radiation-induced bystander effect in liver could be obvious 1 h after radiation and achieved the maximum at 6 h, while the changes could recover gradually at 12 h. The results suggest that mice head exposed to heavy-ion radiation can induce damage and methylation pattern changed in both directly radiation organ ear and distant organ liver. Moreover, our findings are important to understand the molecular mechanism of radiation induced bystander effects in vivo. Keywords: Heavy-ion radiation; Bystander effect; DNA methylation; γH2AX; Mice.

Young children show the bystander effect in helping situations.

PubMed

Plötner, Maria; Over, Harriet; Carpenter, Malinda; Tomasello, Michael

2015-04-01

Much research in social psychology has shown that otherwise helpful people often fail to help when bystanders are present. Research in developmental psychology has shown that even very young children help and that the presence of others can actually increase helping in some cases. In the current study, in contrast, 5-year-old children helped an experimenter at very high levels when they were alone but helped significantly less often in the presence of bystanders who were potentially available to help. In another condition designed to elucidate the mechanism underlying the effect, children's helping was not reduced when bystanders were present but confined behind a barrier and thus unable to help (a condition that has not been run in previous studies with adults). Young children thus show the bystander effect, and it is due not to social referencing or shyness to act in front of others but, rather, to a sense of a diffusion of responsibility. © The Author(s) 2015.

[Radiation-induced bystander effect: the important part of ionizing radiation response. Potential clinical implications].

PubMed

Wideł, Maria; Przybyszewski, Waldemar; Rzeszowska-Wolny, Joanna

2009-08-18

It has long been a central radiobiological dogma that the damaging effects of ionizing radiation, such as cell death, cytogenetic changes, apoptosis, mutagenesis, and carcinogenesis, are the results of the direct ionization of cell structures, particularly DNA, or indirect damage via water radiolysis products. However, several years ago attention turned to a third mechanism of radiation, termed the "bystander effect" or "radiation-induced bystander effect" (RIBE). This is induced by agents and signals emitted by directly irradiated cells and manifests as a lowering of survival, cytogenetic damage, apoptosis enhancement, and biochemical changes in neighboring non-irradiated cells. The bystander effect is mainly observed in in vitro experiments using very low doses of alpha particles (range; mGy, cGy), but also after conventional irradiation (X-rays, gamma rays) at low as well as conventional doses. The mechanisms responsible for the bystander effect are complex and still poorly understood. It is believed that molecular signals released from irradiated cells induce different signaling ways in non-irradiated neighboring cells, leading to the observed events. The molecular signals may be transmitted through gap junction intercellular communication and through a medium transfer mechanism. The nature of these transmitted factors are diverse, and still not definitely established. It seems that RIBE may have important clinical implications for health risk associated with radiation exposure. Potentially, this effect may have important implications in the creation of whole-body or localized side effects in tissues beyond the irradiation field and also in low-dose radiological and radioisotope diagnostics. Factors emitted by irradiated cells may result in the risk of genetic instability, mutations, and second primary cancer induction. They might also have their own part in inducing and extending post-radiation side effects in normal tissue. The bystander effect may be a potentially harmful or a useful event in radiotherapy. The elevation of damage to tumor cells not directly hit by radiation or the initiation of tumor cell differentiation may increase the therapeutic ratio. If, however, molecular species secreted by irradiated tumor cells in vivo damage neighboring normal cells (epithelial and endothelial cells, fibroblasts, or lymphocytes), the bystander effect would be harmful and could lead to increased side effects in normal tissue. This is especially important in modern radiotherapy, as 3D conformal radiation therapy (3D-CRT) and intensity-modulated radiation therapy (IMRT) are aimed at diminishing the radiation dose in normal tissues. Recent in vivo studies on animals indicate that bystander effects may appear in organs and tissues remote from the irradiated field and the extension of tissue damage seems to be tissue-type dependent. However, recent experimental results indicate that non-irradiated cells that are neighbors of irradiated cells may diminish radiation damage in the radiation-focused cells. Less is known about the bystander effect during fractionated irradiation. Thus the clinical implications of the bystander effect and its possible modification for radiotherapeutic usefulness is still under debate.

Induction of a bystander mutagenic effect of alpha particles in mammalian cells

NASA Technical Reports Server (NTRS)

Zhou, H.; Randers-Pehrson, G.; Waldren, C. A.; Vannais, D.; Hall, E. J.; Hei, T. K.; Chatterjee, A. (Principal Investigator)

2000-01-01

Ever since the discovery of X-rays was made by Rontgen more than a hundred years ago, it has always been accepted that the deleterious effects of ionizing radiation such as mutation and carcinogenesis are attributable mainly to direct damage to DNA. Although evidence based on microdosimetric estimation in support of a bystander effect appears to be consistent, direct proof of such extranuclear/extracellular effects are limited. Using a precision charged particle microbeam, we show here that irradiation of 20% of randomly selected A(L) cells with 20 alpha particles each results in a mutant fraction that is 3-fold higher than expected, assuming no bystander modulation effect. Furthermore, analysis by multiplex PCR shows that the types of mutants induced are significantly different from those of spontaneous origin. Pretreatment of cells with the radical scavenger DMSO had no effect on the mutagenic incidence. In contrast, cells pretreated with a 40 microM dose of lindane, which inhibits cell-cell communication, significantly decreased the mutant yield. The doses of DMSO and lindane used in these experiments are nontoxic and nonmutagenic. We further examined the mutagenic yield when 5-10% of randomly selected cells were irradiated with 20 alpha particles each. Results showed, likewise, a higher mutant yield than expected assuming no bystander effects. Our studies provide clear evidence that irradiated cells can induce a bystander mutagenic response in neighboring cells not directly traversed by alpha particles and that cell-cell communication process play a critical role in mediating the bystander phenomenon.

Caspase-3-independent pathways proceeding in bystander effect of HSV-tk/GCV system

NASA Astrophysics Data System (ADS)

Lin, Juqiang; Ma, Yan; Zeng, Shaoqun; Zhang, Zhihong

2008-02-01

HSV-tk/GCV system, which is the virus-directed enzyme/prodrug therapy of herpes simplex virus (HSV) thymidine kinase (tk) gene / the anti-viral reagent ganciclovir (GCV), is one of the promising approaches in the rapidly growing area of gene therapy. As gene therapy of cancer such as suicide gene therapy has entered the clinic, another therapy effect which is called 'bystander effect' was reported. Bystander effect can lead to killing of non-transduced tumor cells in the immediate vicinity of GCV-treated HSV-TK-positive cells. Now the magnitude of 'bystander effect' is an essential factor for this anti-tumor approach in vivo. However, the mechanism which HSV-tk/ACV brings "bystander effect" is poorly understood. In this study, we monitor the activation of caspase-3 in HSV-tk/GCV system by a FRET probe CD3, a FRET-based indicator for activity of caspase3, which is composed of an enhanced cyan fluorescent protein, a caspase-sensitive linker, and a red fluorescent protein from Discosoma with efficient maturation property. Through application of CD3 we have visualized the activation of caspase-3 in tk gene positive human adenoid cystic carcinoma (ACC-M) cells but not in bystander effect of HSV-tk/GCV system induced by GCV. This finding provides needed information for understanding the mechanisms by which suicide gene approaches actually kill cancer cells, and may prove to be helpful for the clinical treatment of cancers.

Exposures involving perturbations of the EM field have non-linear effects on radiation response and can alter the expression of radiation induced bystander effects

NASA Astrophysics Data System (ADS)

Mothersill, Carmel; Seymour, Colin

2012-07-01

Our recent data suggest there is a physical component to the bystander signal induced by radiation exposure and that alternative medicine techniques such as Reiki and acupuncture or exposures to weak EM fields alter the response of cells to direct irradiation and either altered bystander signal production or altered the response of cells receiving bystander signals. Our proposed mechanism to explain these findings is that perturbation of electromagnetic (EM) fields is central to the induction of low radiation dose responses especially non-targeted bystander effects. In this presentation we review the alternative medicine data and other data sets from our laboratory which test our hypothesis that perturbation of bio-fields will modulate radiation response in the low dose region. The other data sets include exposure to MRI, shielding using lead and or Faraday cages, the use of physical barriers to bystander signal transmission and the use of membrane channel blockers. The data taken together strongly suggest that EM field perturbation can modulate low dose response and that in fact the EM field rather than the targeted deposition of ionizing energy in the DNA may be the key determinant of dose response in a cell or organism The results also lead us to suspect that at least when chemical transmission is blocked, bystander signals can be transmitted by other means. Our recent experiments suggest light signals and volatiles are not likely. We conclude that alternative medicine and other techniques involving electromagnetic perturbations can modify the response of cells to low doses of ionizing radiation and can induce bystander effects similar to those seen in medium transfer experiments. In addition to the obvious implications for mechanistic studies of low dose effects, this could perhaps provide a novel target to exploit in space radiation protection and in optimizing therapeutic gain during radiotherapy.

Genomic instability and bystander effects: a paradigm shift in radiation biology?

NASA Technical Reports Server (NTRS)

Morgan, William F.

2002-01-01

A basic paradigm in radiobiology is that, following exposure to ionizing radiation, the deposition of energy in the cell nucleus and the resulting damage to DNA, the principal target, are responsible for the radiation's deleterious biological effects. Findings in two rapidly expanding fields of research--radiation-induced genomic instability and bystander effects--have caused us to reevaluate these central tenets. In this article, the potential influence of induced genomic instability and bystander effects on cellular injury after exposure to low-level radiation will be reviewed.

Bystander's willingness to report theft, physical assault, and sexual assault: the impact of gender, anonymity, and relationship with the offender.

PubMed

Nicksa, Sarah C

2014-01-01

This research examines bystander willingness to report three different crimes to the police or campus authorities among a college student sample (n = 295). Twelve original vignettes varied anonymity when reporting, bystander's relationship with the offender (friend or stranger), and crime type. A factorial analysis of variance showed that main effects were found for crime type, bystander's gender, and bystander's relationship with the offender; anonymity was not significant. The physical assault was the most likely to be reported (4.47), followed by theft (3.26), and sexual assault (2.36). Women were more likely than men to report each crime type, and bystanders who were good friends of the offender were less likely to report than strangers. No two- or three-way interactions were significant, but a significant four-way interaction indicated that anonymity, relationship with the offender, and bystander's gender predicted willingness to report for the sexual assault scenario.

Engaging intercollegiate athletes in preventing and intervening in sexual and intimate partner violence.

PubMed

Moynihan, Mary M; Banyard, Victoria L; Arnold, Julie S; Eckstein, Robert P; Stapleton, Jane G

2010-01-01

the object of this exploratory evaluation was to evaluate the "Bringing in the Bystander" sexual and intimate partner violence prevention program with a new sample of intercollegiate athletes. fifty-three male and female athletes participated in the program (experimental group), and 86 were in the control group. All completed pretest, posttest, and 2-month follow-up surveys, including assessment of rape myth acceptance, intent to engage in bystander behaviors, bystander confidence, and bystander behaviors. the program worked overall and for both women and men, improved bystander confidence and intent to engage in bystander behaviors, and did not create significant backlash effects (ie, worsening of attitudes as a result of program). the program fits with the intent of the National Collegiate Athletic Association CHAMPS/Life Skills program regarding its focus on the overall development of student-athletes and demonstrates the promising bystander approach compatible with the 2007 American College Health Association toolkit, Shifting the Paradigm: Primary Prevention of Sexual Violence.

Action Research Evaluation of Bystander Intervention Training Created by Munche, Stern, and O'Brien

ERIC Educational Resources Information Center

Shiflet, Jacqueline H.

2013-01-01

This qualitative, appreciative inquiry study was an examination of bystander intervention as related to sexual assault in the military. The purpose of the study was to examine how military personnel and Department of Defense civilian employees reflecting diverse backgrounds perceived the effectiveness of bystander intervention training and sexual…

Effects of a Rape Awareness Program on College Women: Increasing Bystander Efficacy and Willingness to Intervene

ERIC Educational Resources Information Center

Foubert, John D.; Langhinrichsen-Rohling, Jennifer; Brasfield, Hope; Hill, Brent

2010-01-01

An experimental study evaluated the efficacy of a sexual assault risk-reduction program on 279 college women that focused on learning characteristics of male perpetrators and teaching bystander intervention techniques. After seeing The Women's Program, participants reported significantly greater bystander efficacy and significantly greater…

Does Non-Targeted Community CPR Training Increase Bystander CPR Frequency?

PubMed

Uber, Amy; Sadler, Richard C; Chassee, Todd; Reynolds, Joshua C

2018-05-01

Only 37% of out-of-hospital cardiac arrests (OHCA) receive bystander Cardiopulmonary resuscitation (CPR) in Kent County, MI. In May 2014, prehospital providers offered one-time, point-of-contact compression-only CPR training to 2,253 passersby at 7 public locations in Grand Rapids, Michigan. To assess the impact of this intervention, we compared bystander CPR frequency and clinical outcomes in regions surrounding training sites before and after the intervention, adjusting for prehospital covariates. We aimed to assess the effect of this broad, non-targeted intervention on bystander CPR frequency, type of CPR utilized, and clinical outcomes. We also tested for differences in geospatial variation of bystander CPR and clinical outcomes clustered around training sites. Retrospective, observational, before-after study of adult, EMS-treated OHCA in Kent County from January 1, 2010 to December 31, 2015. We generated a 5-kilometer radius surrounding each training site to estimate any geospatial influence that training sites might have on bystander CPR frequency in nearby OHCA cases. Chi-squared, Fisher's exact, and t-tests assessed differences in subject features. Difference-in-differences analysis with generalized estimating equation (GEE) modeling assessed bystander CPR frequency, adjusting for training site, covariates (age, sex, witnessed, shockable rhythm, public location), and clustering around training sites. Similar modeling tested for changes in bystander CPR type, return of spontaneous circulation (ROSC), survival to hospital discharge, and cerebral performance category (CPC) of 1-2 at hospital discharge. We included 899 cases before and 587 cases post-intervention. Overall, we observed no increase in the frequency of bystander CPR or favorable clinical outcomes. We did observe an increase in compression-only CPR, but this was paradoxically restricted to OHCA cases falling outside radii around training sites. In adjusted modeling, the bystander CPR training intervention was not associated with bystander CPR frequency (β -0.002; 95% CI -0.16, 0.15), compression-only CPR (β -0.06; 95% CI -0.15, 0.02), ROSC (β -0.06; 95% CI -0.21, 0.25), survival (β -0.02; 95% CI -0.11, 0.06), or favorable neurologic outcome (β -0.01; 95% CI -0.07, 0.09). We observed no impact in bystander CPR performance or outcomes from a blanket, non-targeted approach to community CPR education. The effect of targeted CPR education in locales with known low bystander CPR rates should be tested in this region.

Virtual Bystanders in a Language Lesson: Examining the Effect of Social Evaluation, Vicarious Experience, Cognitive Consistency and Praising on Students' Beliefs, Self-Efficacy and Anxiety in a Virtual Reality Environment

PubMed Central

Qu, Chao; Ling, Yun; Heynderickx, Ingrid; Brinkman, Willem-Paul

2015-01-01

Bystanders in a real world's social setting have the ability to influence people’s beliefs and behavior. This study examines whether this effect can be recreated in a virtual environment, by exposing people to virtual bystanders in a classroom setting. Participants (n = 26) first witnessed virtual students answering questions from an English teacher, after which they were also asked to answer questions from the teacher as part of a simulated training for spoken English. During the experiment the attitudes of the other virtual students in the classroom was manipulated; they could whisper either positive or negative remarks to each other when a virtual student was talking or when a participant was talking. The results show that the expressed attitude of virtual bystanders towards the participants affected their self-efficacy, and their avoidance behavior. Furthermore, the experience of witnessing bystanders commenting negatively on the performance of other students raised the participants’ heart rate when it was their turn to speak. Two-way interaction effects were also found on self-reported anxiety and self-efficacy. After witnessing bystanders’ positive attitude towards peer students, participants’ self-efficacy when answering questions received a boost when bystanders were also positive towards them, and a blow when bystanders reversed their attitude by being negative towards them. Still, inconsistency, instead of consistency, between the bystanders’ attitudes towards virtual peers and the participants was not found to result in a larger change in the participants’ beliefs. Finally the results also reveal that virtual flattering or destructive criticizing affected the participants’ beliefs not only about the virtual bystanders, but also about the neutral teacher. Together these findings show that virtual bystanders in a classroom can affect people’s beliefs, anxiety and behavior. PMID:25884211

TakeCARE, a Video Bystander Program to Help Prevent Sexual Violence on College Campuses: Results of Two Randomized, Controlled Trials

PubMed Central

Jouriles, Ernest N.; McDonald, Renee; Rosenfield, David; Levy, Nicole; Sargent, Kelli; Caiozzo, Christina; Grych, John H.

2015-01-01

Objective The present research reports on two randomized controlled trials evaluating TakeCARE, a video bystander program designed to help prevent sexual violence on college campuses. Method In Study 1, students were recruited from psychology courses at two universities. In Study 2, first-year students were recruited from a required course at one university. In both studies, students were randomly assigned to view one of two videos: TakeCARE or a control video on study skills. Just before viewing the videos, students completed measures of bystander behavior toward friends and ratings of self-efficacy for performing such behaviors. The efficacy measure was administered again after the video, and both the bystander behavior measure and the efficacy measure were administered at either one (Study 1) or two (Study 2) months later. Results In both studies, students who viewed TakeCARE, compared to students who viewed the control video, reported engaging in more bystander behavior toward friends and greater feelings of efficacy for performing such behavior. In Study 1, feelings of efficacy mediated effects of TakeCARE on bystander behavior; this result did not emerge in Study 2. Conclusions This research demonstrates that TakeCARE, a video bystander program, can positively influence bystander behavior toward friends. Given its potential to be easily distributed to an entire campus community, TakeCARE might be an effective addition to campus efforts to prevent sexual violence. PMID:27867694

Genetic changes in progeny of bystander human fibroblasts after microbeam irradiation with X-rays, protons or carbon ions: the relevance to cancer risk.

PubMed

Autsavapromporn, Narongchai; Plante, Ianik; Liu, Cuihua; Konishi, Teruaki; Usami, Noriko; Funayama, Tomoo; Azzam, Edouard I; Murakami, Takeshi; Suzuki, Masao

2015-01-01

Radiation-induced bystander effects have important implications in radiotherapy. Their persistence in normal cells may contribute to risk of health hazards, including cancer. This study investigates the role of radiation quality and gap junction intercellular communication (GJIC) in the propagation of harmful effects in progeny of bystander cells. Confluent human skin fibroblasts were exposed to microbeam radiations with different linear energy transfer (LET) at mean absorbed doses of 0.4 Gy by which 0.036-0.4% of the cells were directly targeted by radiation. Following 20 population doublings, the cells were harvested and assayed for micronucleus formation, gene mutation and protein oxidation. Our results showed that expression of stressful effects in the progeny of bystander cells is dependent on LET. The progeny of bystander cells exposed to X-rays (LET ∼6 keV/μm) or protons (LET ∼11 keV/μm) showed persistent oxidative stress, which correlated with increased micronucleus formation and mutation at the hypoxanthine-guanine phosphoribosyl-transferase (HPRT) locus. Such effects were not observed after irradiation by carbon ions (LET ∼103 keV/μm). Interestingly, progeny of bystander cells from cultures exposed to protons or carbon ions under conditions where GJIC was inhibited harbored reduced oxidative and genetic damage. This mitigating effect was not detected when the cultures were exposed to X-rays. These findings suggest that cellular exposure to proton and heavy charged particle with LET properties similar to those used here can reduce the risk of lesions associated with cancer. The ability of cells to communicate via gap junctions at the time of irradiation appears to impact residual damage in progeny of bystander cells.

Not All Behind Closed Doors: Examining Bystander Involvement in Intimate Partner Violence.

PubMed

Taylor, Elizabeth; Banyard, Victoria; Grych, John; Hamby, Sherry

2016-10-01

It is often said that intimate partner violence (IPV) happens "behind closed doors"; however, research on IPV and other crimes suggests that witnesses are sometimes present. This suggests that bystanders may be in a position to help victims or potential victims of violence. Bystander behavior has been studied primarily in school settings, and consequently, little is known about how often it occurs or what its effects may be in the broader community. This study examined IPV incidents in a rural sample to assess the presence and potential impact of bystanders on victim-reported outcomes. One thousand nine hundred seventy-seven adult participants completed a questionnaire that asked about five violent behaviors (my partner threatened to hurt me; pushed, grabbed, or shook me; hit me; beat me up; sexually assaulted me), bystander characteristics, and victim outcomes (fear; injury; disruption of daily routines; mental health). Adult or teen bystanders were present for each IPV approximately one third of the time, except in the case of sexual assault (14.3%). When a bystander was present, victims reported higher rates of injury, greater disruption in their routines, and poorer mental health. When a bystander's safety was threatened, victims reported more physical injury and more routine disruption. A considerable number of IPV incidents do not happen behind closed doors, and the presence of a bystander was associated with worse outcomes for victims. Prevention efforts for adult IPV may need to take a more cautious or nuanced approach to encouraging bystander action, especially when confronted with more severe incidents. Bystander safety should be a priority for violence prevention.

Do dispatcher instructions facilitate bystander-initiated cardiopulmonary resuscitation and improve outcomes in patients with out-of-hospital cardiac arrest? A comparison of family and non-family bystanders.

PubMed

Fujie, Keiko; Nakata, Yoshio; Yasuda, Susumu; Mizutani, Taro; Hashimoto, Koichi

2014-03-01

Bystander-initiated cardiopulmonary resuscitation (CPR) has been reported to increase the possibility of survival in patients with out-of-hospital cardiopulmonary arrest (OHCA). We evaluated the effects of CPR instructions by emergency medical dispatchers on the frequency of bystander CPR and outcomes, and whether these effects differed between family and non-family bystanders. We conducted a retrospective cohort study, using Utstein-style records of OHCA taken in a rural area of Japan between January 2004 and December 2009. Of the 559 patients with non-traumatic OHCA witnessed by laypeople, 231 (41.3%) were given bystander CPR. More OHCA patients received resuscitation when the OHCA was witnessed by non-family bystanders than when it was witnessed by family members (61.4% vs. 34.2%). The patients with non-family-witnessed OHCA were more likely to be given conventional CPR (chest compression plus rescue breathing) or defibrillation with an AED than were those with family-witnessed OHCA. Dispatcher instructions significantly increased the provision of bystander CPR regardless of who the witnesses were. Neurologically favorable survival was increased by CPR in non-family-witnessed, but not in family-witnessed, OHCA patients. No difference in survival rate was observed between the cases provided with dispatcher instructions and those not provided with the instructions. Dispatcher instructions increased the frequency of bystander CPR, but did not improve the rate of neurologically favorable survival in patients with witnessed OHCA. Efforts to enhance the frequency and quality of resuscitation, especially by family members, are required for dispatcher-assisted CPR. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

The differential role of human macrophage in triggering secondary bystander effects after either gamma-ray or carbon beam irradiation

PubMed Central

Dong, Chen; He, Mingyuan; Tu, Wenzhi; Konishi, Teruaki; Liu, Weili; Xie, Yuexia; Dang, Bingrong; Li, Wenjian; Uchihori, Yukio; Hei, Tom K.; Shao, Chunlin

2015-01-01

The abscopal effect could be an underlying factor in evaluating prognosis of radiotherapy. This study established an in vitro system to examine whether tumor-generated bystander signals could be transmitted by macrophages to further trigger secondary cellular responses after different irradiations, where human lung cancer NCI-H446 cells were irradiated with either γ-rays or carbon ions and co-cultured with human macrophage U937 cells, then these U937 cells were used as a bystander signal transmitter and co-cultured with human bronchial epithelial cells BEAS-2B. Results showed that U937 cells were only activated by γ-irradiated NCI-H446 cells so that the secondary injuries in BEAS-2B cells under carbon ion irradiation were weaker than γ-rays. Both TNF-α and IL-1α were involved in γ-irradiation induced secondary bystander effect but only TNF-α contributed to the carbon ion induced response. Further assay disclosed that IL-1α but not TNF-α was largely responsible for the activation of macrophages and the formation of micronucleus in BEAS-2B cells. These data suggest that macrophages could transfer secondary bystander signals and play a key role in the secondary bystander effect of photon irradiation while carbon ion irradiation has conspicuous advantage due to its reduced secondary injury. PMID:25896631

The differential role of human macrophage in triggering secondary bystander effects after either gamma-ray or carbon beam irradiation.

PubMed

Dong, Chen; He, Mingyuan; Tu, Wenzhi; Konishi, Teruaki; Liu, Weili; Xie, Yuexia; Dang, Bingrong; Li, Wenjian; Uchihori, Yukio; Hei, Tom K; Shao, Chunlin

2015-07-10

The abscopal effect could be an underlying factor in evaluating prognosis of radiotherapy. This study established an in vitro system to examine whether tumor-generated bystander signals could be transmitted by macrophages to further trigger secondary cellular responses after different irradiations, where human lung cancer NCI-H446 cells were irradiated with either γ-rays or carbon ions and co-cultured with human macrophage U937 cells, then these U937 cells were used as a bystander signal transmitter and co-cultured with human bronchial epithelial cells BEAS-2B. Results showed that U937 cells were only activated by γ-irradiated NCI-H446 cells so that the secondary injuries in BEAS-2B cells under carbon ion irradiation were weaker than γ-rays. Both TNF-α and IL-1α were involved in the γ-irradiation induced secondary bystander effect but only TNF-α contributed to the carbon ion induced response. Further assay disclosed that IL-1α but not TNF-α was largely responsible for the activation of macrophages and the formation of micronucleus in BEAS-2B cells. These data suggest that macrophages could transfer secondary bystander signals and play a key role in the secondary bystander effect of photon irradiation, while carbon ion irradiation has conspicuous advantage due to its reduced secondary injury. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Sci—Fri PM: Topics — 04: What if bystander effects influence cell kill within a target volume? Potential consequences of dose heterogeneity on TCP and EUD on intermediate risk prostate patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balderson, M.J.; Kirkby, C.; Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta

In vitro evidence has suggested that radiation induced bystander effects may enhance non-local cell killing which may influence radiotherapy treatment planning paradigms. This work applies a bystander effect model, which has been derived from published in vitro data, to calculate equivalent uniform dose (EUD) and tumour control probability (TCP) and compare them with predictions from standard linear quadratic (LQ) models that assume a response due only to local absorbed dose. Comparisons between the models were made under increasing dose heterogeneity scenarios. Dose throughout the CTV was modeled with normal distributions, where the degree of heterogeneity was then dictated by changingmore » the standard deviation (SD). The broad assumptions applied in the bystander effect model are intended to place an upper limit on the extent of the results in a clinical context. The bystander model suggests a moderate degree of dose heterogeneity yields as good or better outcome compared to a uniform dose in terms of EUD and TCP. Intermediate risk prostate prescriptions of 78 Gy over 39 fractions had maximum EUD and TCP values at SD of around 5Gy. The plots only dropped below the uniform dose values for SD ∼ 10 Gy, almost 13% of the prescribed dose. The bystander model demonstrates the potential to deviate from the common local LQ model predictions as dose heterogeneity through a prostate CTV is varies. The results suggest the potential for allowing some degree of dose heterogeneity within a CTV, although further investigations of the assumptions of the bystander model are warranted.« less

Signaling pathways underpinning the manifestations of ionizing radiation-induced bystander effects.

PubMed

Hamada, Nobuyuki; Maeda, Munetoshi; Otsuka, Kensuke; Tomita, Masanori

2011-06-01

For nearly a century, ionizing radiation has been indispensable to medical diagnosis. Furthermore, various types of electromagnetic and particulate radiation have also been used in cancer therapy. However, the biological mechanism of radiation action remains incompletely understood. In this regard, a rapidly growing body of experimental evidence indicates that radiation exposure induces biological effects in cells whose nucleus has not been irradiated. This phenomenon termed the 'non-targeted effects' challenges the long-held tenet that radiation traversal through the cell nucleus is a prerequisite to elicit genetic damage and biological responses. The non-targeted effects include biological effects in cytoplasm-irradiated cells, bystander effects that arise in non-irradiated cells having received signals from irradiated cells, and genomic instability occurring in the progeny of irradiated cells. Such non-targeted responses are interrelated, and the bystander effect is further related with an adaptive response that manifests itself as the attenuated stressful biological effects of acute high-dose irradiation in cells that have been pre-exposed to low-dose or low-dose-rate radiation. This paper reviews the current body of knowledge about the bystander effect with emphasis on experimental approaches, in vitro and in vivo manifestations, radiation quality dependence, temporal and spatial dependence, proposed mechanisms, and clinical implications. Relations of bystander responses with the effects in cytoplasm-irradiated cells, genomic instability and adaptive response will also be briefly discussed.

Potential implications of the bystander effect on TCP and EUD when considering target volume dose heterogeneity.

PubMed

Balderson, Michael J; Kirkby, Charles

2015-01-01

In light of in vitro evidence suggesting that radiation-induced bystander effects may enhance non-local cell killing, there is potential for impact on radiotherapy treatment planning paradigms such as the goal of delivering a uniform dose throughout the clinical target volume (CTV). This work applies a bystander effect model to calculate equivalent uniform dose (EUD) and tumor control probability (TCP) for external beam prostate treatment and compares the results with a more common model where local response is dictated exclusively by local absorbed dose. The broad assumptions applied in the bystander effect model are intended to place an upper limit on the extent of the results in a clinical context. EUD and TCP of a prostate cancer target volume under conditions of increasing dose heterogeneity were calculated using two models: One incorporating bystander effects derived from previously published in vitro bystander data ( McMahon et al. 2012 , 2013a); and one using a common linear-quadratic (LQ) response that relies exclusively on local absorbed dose. Dose through the CTV was modelled as a normal distribution, where the degree of heterogeneity was then dictated by changing the standard deviation (SD). Also, a representative clinical dose distribution was examined as cold (low dose) sub-volumes were systematically introduced. The bystander model suggests a moderate degree of dose heterogeneity throughout a target volume will yield as good or better outcome compared to a uniform dose in terms of EUD and TCP. For a typical intermediate risk prostate prescription of 78 Gy over 39 fractions maxima in EUD and TCP as a function of increasing SD occurred at SD ∼ 5 Gy. The plots only dropped below the uniform dose values for SD ∼ 10 Gy, almost 13% of the prescribed dose. Small, but potentially significant differences in the outcome metrics between the models were identified in the clinically-derived dose distribution as cold sub-volumes were introduced. In terms of EUD and TCP, the bystander model demonstrates the potential to deviate from the common local LQ model predictions as dose heterogeneity through a prostate CTV varies. The results suggest, at least in a limiting sense, the potential for allowing some degree of dose heterogeneity within a CTV, although further investigation of the assumptions of the bystander model are warranted.

Irradiation of rainbow trout at early life stages results in trans-generational effects including the induction of a bystander effect in non-irradiated fish

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Richard W., E-mail: rich.wilson.smith@gmail.com; Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario; Seymour, Colin B.

The bystander effect, a non-targeted effect (NTE) of radiation, which describes the response by non-irradiated organisms to signals emitted by irradiated organisms, has been documented in a number of fish species. However transgenerational effects of radiation (including NTE) have yet to be studied in fish. Therefore rainbow trout, which were irradiated as eggs at 48 h after fertilisation, eyed eggs, yolk sac larvae or first feeders, were bred to generate a F1 generation and these F1 fish were bred to generate a F2 generation. F1 and F2 fish were swam with non-irradiated bystander fish. Media from explants of F1 eyedmore » eggs, F1 one year old fish gill and F1 two year old fish gill and spleen samples, and F2 two year old gill and spleen samples, as well as from bystander eggs/fish, was used to treat a reporter cell line, which was then assayed for changes in cellular survival/growth. The results were complex and dependent on irradiation history, age (in the case of the F1 generation), and were tissue specific. For example, irradiation of one parent often resulted in effects not seen with irradiation of both parents. This suggests that, unlike mammals, in certain circumstances maternal and paternal irradiation may be equally important. This study also showed that trout can induce a bystander effect 2 generations after irradiation, which further emphasises the importance of the bystander effect in aquatic radiobiology. Given the complex community structure in aquatic ecosystems, these results may have significant implications for environmental radiological protection. - Highlights: • We evaluated the transgenerational effect of early life irradiation in rainbow trout. • Trout irradiated as eggs, yolk sac larvae or first feeders were crossed. • A transgenerational effect was evident in two generations after irradiation. • F1 and F2 generation fish induced a bystander effect in non-irradiated fish. • The precise effects were tissue specific and dependent on parental radiation history.« less

Post-conflict affiliation as conflict management in captive bottlenose dolphins (Tursiops truncatus)

PubMed Central

Yamamoto, Chisato; Morisaka, Tadamichi; Furuta, Keisuke; Ishibashi, Toshiaki; Yoshida, Akihiko; Taki, Michihiro; Mori, Yoshihisa; Amano, Masao

2015-01-01

Post-conflict affiliation between former opponents or between one of the former opponents and bystanders might have the function of conflict management, which reduces the costs associated with aggressions. One of the suggested functions of post-conflict affiliation is decreased renewed aggressions directed from aggressors to victims. However, the effect of post-conflict affiliation on renewed aggressions by victims has not been investigated. We examined whether post-conflict affiliations decreased the number of renewed aggressions initiated by winners or losers in captive bottlenose dolphins. Both winners and losers initiated renewed aggressions. However, these aggressions decreased after post-conflict affiliation between former opponents, initiated by bystanders to winners, initiated by losers to bystanders, and initiated by bystanders to losers. Post-conflict affiliation between former opponents is suggested to function as reconciliation. Post–conflict affiliation initiated by losers to bystanders is suggested to function as the protection of losers. Post-conflict affiliations initiated by bystanders to one of former opponents are suggested to function as both appeasement and protection of the opponent who affiliates with bystanders. PMID:26392064

Post-conflict affiliation as conflict management in captive bottlenose dolphins (Tursiops truncatus).

PubMed

Yamamoto, Chisato; Morisaka, Tadamichi; Furuta, Keisuke; Ishibashi, Toshiaki; Yoshida, Akihiko; Taki, Michihiro; Mori, Yoshihisa; Amano, Masao

2015-09-22

Post-conflict affiliation between former opponents or between one of the former opponents and bystanders might have the function of conflict management, which reduces the costs associated with aggressions. One of the suggested functions of post-conflict affiliation is decreased renewed aggressions directed from aggressors to victims. However, the effect of post-conflict affiliation on renewed aggressions by victims has not been investigated. We examined whether post-conflict affiliations decreased the number of renewed aggressions initiated by winners or losers in captive bottlenose dolphins. Both winners and losers initiated renewed aggressions. However, these aggressions decreased after post-conflict affiliation between former opponents, initiated by bystanders to winners, initiated by losers to bystanders, and initiated by bystanders to losers. Post-conflict affiliation between former opponents is suggested to function as reconciliation. Post-conflict affiliation initiated by losers to bystanders is suggested to function as the protection of losers. Post-conflict affiliations initiated by bystanders to one of former opponents are suggested to function as both appeasement and protection of the opponent who affiliates with bystanders.

Irradiation of rainbow trout at early life stages results in trans-generational effects including the induction of a bystander effect in non-irradiated fish.

PubMed

Smith, Richard W; Seymour, Colin B; Moccia, Richard D; Mothersill, Carmel E

2016-02-01

The bystander effect, a non-targeted effect (NTE) of radiation, which describes the response by non-irradiated organisms to signals emitted by irradiated organisms, has been documented in a number of fish species. However transgenerational effects of radiation (including NTE) have yet to be studied in fish. Therefore rainbow trout, which were irradiated as eggs at 48h after fertilisation, eyed eggs, yolk sac larvae or first feeders, were bred to generate a F1 generation and these F1 fish were bred to generate a F2 generation. F1 and F2 fish were swam with non-irradiated bystander fish. Media from explants of F1 eyed eggs, F1 one year old fish gill and F1 two year old fish gill and spleen samples, and F2 two year old gill and spleen samples, as well as from bystander eggs/fish, was used to treat a reporter cell line, which was then assayed for changes in cellular survival/growth. The results were complex and dependent on irradiation history, age (in the case of the F1 generation), and were tissue specific. For example, irradiation of one parent often resulted in effects not seen with irradiation of both parents. This suggests that, unlike mammals, in certain circumstances maternal and paternal irradiation may be equally important. This study also showed that trout can induce a bystander effect 2 generations after irradiation, which further emphasises the importance of the bystander effect in aquatic radiobiology. Given the complex community structure in aquatic ecosystems, these results may have significant implications for environmental radiological protection. Copyright © 2015 Elsevier Inc. All rights reserved.

Bystander Cardiopulmonary Resuscitation Is Clustered and Associated With Neighborhood Socioeconomic Characteristics: A Geospatial Analysis of Kent County, Michigan.

PubMed

Uber, Amy; Sadler, Richard C; Chassee, Todd; Reynolds, Joshua C

2017-08-01

Geographic clustering of bystander cardiopulmonary resuscitation (CPR) is associated with demographic and socioeconomic features of the community where out-of-hospital cardiac arrest (OHCA) occurred, although this association remains largely untested in rural areas. With a significant rural component and relative racial homogeneity, Kent County, Michigan, provides a unique setting to externally validate or identify new community features associated with bystander CPR. Using a large, countywide data set, we tested for geographic clustering of bystander CPR and its associations with community socioeconomic features. Secondary analysis of adult OHCA subjects (2010-2015) in the Cardiac Arrest Registry to Enhance Survival (CARES) data set for Kent County, Michigan. After linking geocoded OHCA cases to U.S. census data, we used Moran's I-test to assess for spatial autocorrelation of population-weighted cardiac arrest rate by census block group. Getis-Ord Gi statistic assessed for spatial clustering of bystander CPR and mixed-effects hierarchical logistic regression estimated adjusted associations between community features and bystander CPR. Of 1,592 subjects, 1,465 met inclusion criteria. Geospatial analysis revealed significant clustering of OHCA in more populated/urban areas. Conversely, bystander CPR was less likely in these areas (99% confidence) and more likely in suburban and rural areas (99% confidence). Adjusting for clinical, demographic, and socioeconomic covariates, bystander CPR was associated with public location (odds ratio [OR] = 1.19; 95% confidence interval [CI] = 1.03-1.39), initially shockable rhythms (OR = 1.48; 95% CI = 1.12-1.96), and those in urban neighborhoods (OR = 0.54; 95% CI = 0.38-0.77). Out-of-hospital cardiac arrest and bystander CPR are geographically clustered in Kent County, Michigan, but bystander CPR is inversely associated with urban designation. These results offer new insight into bystander CPR patterns in mixed urban and rural regions and afford the opportunity for targeted community CPR education in areas of low bystander CPR prevalence. © 2017 by the Society for Academic Emergency Medicine.

Estimating cost-effectiveness of mass cardiopulmonary resuscitation training strategies to improve survival from cardiac arrest in private locations.

PubMed

Swor, Robert; Compton, Scott

2004-01-01

Most cardiopulmonary resuscitation (CPR) trainees are young, and most cardiac arrests occur in private residences witnessed by older individuals. To estimate the cost-effectiveness of a CPR training program targeted at citizens over the age of 50 years compared with that of current nontargeted public CPR training. A model was developed using cardiac arrest and known demographic data from a single suburban zip code (population 36,325) including: local data (1997-1999) regarding cardiac arrest locations (public vs. private); incremental survival with CPR (historical survival rate 7.8%, adjusted odds ratio for CPR 2.0); arrest bystander demographics obtained from bystander telephone interviews; zip code demographics regarding population age and distribution; and 12.50 dollars per student for the cost of CPR training. Published rates of CPR training programs by age were used to estimate the numbers typically trained. Several assumptions were made: 1) there would be one bystander per. arrest; 2) the bystander would always perform CPR if trained; 3) cardiac arrest would be evenly distributed in the population; and 4) CPR training for a proportion of the population would proportionally increase CPR provision. Rates of arrest, bystanders by age, number of CPR trainees needed to result in increased arrest survival, and training cost per life saved for a one-year study period were calculated. There were 24.3 cardiac arrests per year, with 21.9 (90%) occurring in homes. In 66.5% of the home arrests, the bystander was more than 50 years old. To yield one additional survivor using the current CPR training strategy, 12,306 people needed to be trained (3,510 bystanders aged < or = 50 years and 8,796 bystanders aged > 50 years), which resulted in CPR provision to 7.14 additional patients. The training cost per life saved for a bystander aged < or = 50 years was 313,214 dollars, and that for a bystander aged > 50 years was 785,040 dollars. Using a strategy of training only those < or = 50 years, 583 elders per cardiac arrest would need to be trained, with a cost of 53,383 dollars per life saved. Using these assumptions, current CPR training strategy is not a cost-effective intervention for home cardiac arrests. The high rate of elders witnessing CPR mandates focused CPR interventions for this population.

The influence of smoking on radiation-induced bystander signal production in esophageal cancer patients.

PubMed

Hanu, C; Timotin, E; Wong, R; Sur, R K; Hayward, J E; Seymour, C B; Mothersill, C E

2016-05-01

The relevance of radiation-induced bystander effects in humans is unclear. Much of the existing data relate to cell lines but the effect of bystander signals in complex human tissues is unclear. A phase II clinical study was untaken, where blood sera from 60 patients along with 15 cancer-free volunteers were used to detect whether measurable bystander factor(s) could be found in the blood following high dose rate (HDR) brachytherapy. Overall, there was no significant change in bystander signal production (measured in a human keratinocyte reporter system) before and after one treatment fraction of HDR brachytherapy (p>0.05). Further assessment of patient characteristics and environmental modifiable factors including smoking were also analyzed. Similar to previously published data, samples taken from smokers produced weaker signals compared to non-smokers (p<0.05). Although the number of non-smoking subjects was low, there was a clear decrease in cloning efficiency observed in keratinocyte cultures for these patients that requires further study. This study found that samples taken from smokers do not produce bystander signals, whereas samples taken from non-smokers can produce such signals following HDR brachytherapy. These findings highlight the importance of studying the interactions of multiple stressors including environmental modifiers with radiation, since some factors such as smoking may elicit protection in tumor cells which could counteract the effectiveness of radiation therapy. Copyright © 2015 Elsevier Inc. All rights reserved.

Bystander Attitudes to Prevent Sexual Assault: A Study of College Students in the United States, Japan, India, Vietnam, and China.

PubMed

Kamimura, Akiko; Trinh, Ha Ngoc; Nguyen, Hanh; Yamawaki, Niwako; Bhattacharya, Haimanti; Mo, Wenjing; Birkholz, Ryan; Makomenaw, Angie; Olson, Lenora M

2016-01-01

College women are at a high risk of sexual assault. Although programs that aim to change bystander behaviors have been shown to be potentially effective in preventing sexual assault on campuses in the United States, little is known about bystander behaviors outside of the United States. The purpose of this study was to explore and compare factors affecting bystander behaviors regarding sexual assault intervention and prevention among undergraduate students in the United States, Japan, India, Vietnam, and China. A total of 1,136 students participated in a self-reported survey. Results demonstrate substantial variations across countries. Bystander behaviors are associated with multilevel factors, including gender, knowledge of individuals who have experienced a sexual assault, and knowledge about campus or community organizations.

The release of bystander factor(s) from tissue explant cultures of rainbow trout (Onchorhynchus mykiss) after exposure to gamma radiation.

PubMed

O'Dowd, Colm; Mothersill, Carmel E; Cairns, Michael T; Austin, Brian; McClean, Brendan; Lyng, Fiona M; Murphy, James E J

2006-10-01

The bystander response has been documented in cell lines and cell cultures derived from aquatic species over the past several years. However, little work has been undertaken to identify a similar bystander response in tissue explant cultures from fish. In this study, indirect effects of ionizing gamma radiation on tissue explant cultures of fish were investigated. Tissue explants in culture were exposed to 0.5 Gy and 5 Gy gamma radiation from a 60Co teletherapy unit. A bystander response in Epithelioma papulosum cyprini (EPC) cells exposed to gamma-irradiated tissue conditioned medium from rainbow trout explants was investigated, and the effects on cell survival were quantified by the clonogenic survival assay. Dichlorofluorescein and rhodamine 123 fluorescent dyes were used to identify alterations in reactive oxygen species (ROS) and mitochondrial membrane potential (MMP), respectively. Results indicate a different response for the three tissue types investigated. Clonogenic assay results vary from a decrease in cell survival (gill) to no effect (skin) to a stimulatory effect (spleen). Results from fluorescence assays of ROS and MMP show similarities to clonogenic assay results. This study identifies a useful model for further studies relating to the bystander effect in aquatic organisms in vivo and ex vivo.

Modifiers of Neighbors' Bystander Intervention in Intimate Partner Violence: A Concept Mapping Study.

PubMed

Wee, Sara; Todd, Mary-Justine; Oshiro, Michael; Greene, Emily; Frye, Victoria

2016-03-01

Encouraging bystander intervention in intimate partner violence (IPV) against women is potentially an important method of reducing the prevalence of such violence in urban communities. Most existing research has been conducted on campuses and in relation to sexual violence among teens or young adults. Our understanding of which bystander behaviors are feasible is nascent, and our knowledge of which situational factors influence neighbors' self-reported willingness to intervene is underdeveloped. We conducted a concept mapping study to identify potential bystander intervention behaviors in IPV among neighbors in urban settings; we also assessed whether perceived feasibility and effectiveness of those behaviors varied by situational characteristics. Using data collected from 41 residents of a low-income New York City neighborhood in late 2011, concept mapping was used to create a conceptual map of the 74 behaviors identified by participants. We examined participant differences in mean feasibility (i.e., that the participants "could" or "would" enact a behavior), feasibility given two situational characteristics (if the couple was perceived to have a history of IPV, and if children were believed to be involved or present), and perceived effectiveness of bystander behaviors. Differences across select sociodemographic factors of participants were also analyzed. A 13-cluster solution emerged, with clusters of bystander behaviors grouped into four larger cluster areas: victim focused, parenting/education focused, perpetrator focused, and community involvement focused. Bivariate analyses revealed that participants rated the four cluster areas as more feasible when a child was believed to be involved. Male participants rated intervention as less feasible when the couple was believed to have a history of IPV. Participants who reported a history of IPV victimization rated all four cluster areas as less effective on average, as compared with participants without a history of IPV. This study explored bystander intervention into IPV outside of a college context and among urban adults living in high-poverty areas. Results suggest that the presence of children and perceived history of IPV may affect bystander intervention. Specific recommendations to build the research base on bystander intervention in adult IPV as well as what situational, sociodemographic, and other factors mitigate against intervention among potential responders are offered.

Bystander effects in unicellular organisms.

PubMed

DeVeaux, Linda C; Durtschi, Lynn S; Case, Jonathan G; Wells, Douglas P

2006-05-11

Radiation-induced bystander effects have been seen in mammalian cells from diverse origins. These effects can be transmitted through the medium to cells not present at the time of irradiation. We have developed an assay for detecting bystander effects in the unicellular eukaryote, the fission yeast Schizosaccharomyces pombe. This assay allows maximal exposure of unirradiated cells to cells that have received electron beam irradiation. S. pombe cells were irradiated with 16-18 MeV electrons from a pulsed electron LINAC. When survival of the irradiated cells decreased to approximately 50%, forward-mutation to 2-deoxy-d-glucose resistance increased in the unirradiated bystander cells. Further increase in dose had no additional effect on this increase. In order to detect this response, it was necessary for the irradiated cell/unirradiated cell ratio to be high. Other cellular stresses, such as heat treatment, UV irradiation, and bleomycin exposure, also caused a detectable response in untreated cells grown with the treated cells. We discuss evolutionary implications of these results.

Critical role of gap junction communication, calcium and nitric oxide signaling in bystander responses to focal photodynamic injury

PubMed Central

Calì, Bianca; Ceolin, Stefano; Ceriani, Federico; Bortolozzi, Mario; Agnellini, Andrielly H.R.; Zorzi, Veronica; Predonzani, Andrea; Bronte, Vincenzo

2015-01-01

Ionizing and nonionizing radiation affect not only directly targeted cells but also surrounding “bystander” cells. The underlying mechanisms and therapeutic role of bystander responses remain incompletely defined. Here we show that photosentizer activation in a single cell triggers apoptosis in bystander cancer cells, which are electrically coupled by gap junction channels and support the propagation of a Ca2+ wave initiated in the irradiated cell. The latter also acts as source of nitric oxide (NO) that diffuses to bystander cells, in which NO levels are further increased by a mechanism compatible with Ca2+-dependent enzymatic production. We detected similar signals in tumors grown in dorsal skinfold chambers applied to live mice. Pharmacological blockade of connexin channels significantly reduced the extent of apoptosis in bystander cells, consistent with a critical role played by intercellular communication, Ca2+ and NO in the bystander effects triggered by photodynamic therapy. PMID:25868859

I know what you did: The effects of interpersonal deviance on bystanders.

PubMed

Ferguson, Merideth; Barry, Bruce

2011-01-01

Using social information processing theory, we explore how interpersonally directed deviance affects work group members who observe or are aware of these insidious behaviors. In a field study, we find that indirect knowledge of work group member interpersonal deviance leads to subsequent interpersonal deviance of a focal individual. We also find that when work group cohesion is high, direct observation of deviance is more likely to result in subsequent bystander deviance. These findings add concretely to theory and research on the bystander effects of workplace deviance.

Tanshinone IIA Increases the Bystander Effect of Herpes Simplex Virus Thymidine Kinase/Ganciclovir Gene Therapy via Enhanced Gap Junctional Intercellular Communication

PubMed Central

Liu, Xijuan; Wu, Yingya; Du, Biaoyan; Li, Jiefen; Zhou, Jing; Li, Jingjing; Tan, Yuhui

2013-01-01

The bystander effect is an intriguing phenomenon by which adjacent cells become sensitized to drug treatment during gene therapy with herpes simplex virus thymidine kinase/ganciclovir (HSV-tk/GCV). This effect is reported to be mediated by gap junctional intercellular communication (GJIC), and therefore, we postulated that upregulation of genes that facilitate GJIC may enhance the HSV-tk/GCV bystander effect. Previous findings have shown Tanshinone IIA (Tan IIA), a chemical substance derived from a Chinese medicine herb, promotes the upregulation of the connexins Cx26 and Cx43 in B16 cells. Because gap junctions are formed by connexins, we hypothesized that Tan IIA might increase GJIC. Our results show that Tan IIA increased GJIC in B16 melanoma cells, leading to more efficient GCV-induced bystander killing in cells stably expressing HSV-tk. Additionally, in vivo experiments demonstrated that tumors in mice with 10% HSV-tk positive B16 cells and 90% wild-type B16 cells became smaller following treatment with the combination of GCV and Tan IIA as compared to GCV or Tan IIA alone. These data demonstrate that Tan IIA can augment the bystander effect of HSV-tk/GCV system through increased gap junction coupling, which adds strength to the promising strategy that develops connexins inducer to potentiate the effects of suicide gene therapy. PMID:23861780

A review: Development of a microdose model for analysis of adaptive response and bystander dose response behavior.

PubMed

Leonard, Bobby E

2008-02-27

Prior work has provided incremental phases to a microdosimetry modeling program to describe the dose response behavior of the radio-protective adaptive response effect. We have here consolidated these prior works (Leonard 2000, 2005, 2007a, 2007b, 2007c) to provide a composite, comprehensive Microdose Model that is also herein modified to include the bystander effect. The nomenclature for the model is also standardized for the benefit of the experimental cellular radio-biologist. It extends the prior work to explicitly encompass separately the analysis of experimental data that is 1.) only dose dependent and reflecting only adaptive response radio-protection, 2.) both dose and dose-rate dependent data and reflecting only adaptive response radio-protection for spontaneous and challenge dose damage, 3.) only dose dependent data and reflecting both bystander deleterious damage and adaptive response radio-protection (AR-BE model). The Appendix cites the various applications of the model. Here we have used the Microdose Model to analyze the, much more human risk significant, Elmore et al (2006) data for the dose and dose rate influence on the adaptive response radio-protective behavior of HeLa x Skin cells for naturally occurring, spontaneous chromosome damage from a Brachytherapy type (125)I photon radiation source. We have also applied the AR-BE Microdose Model to the Chromosome inversion data of Hooker et al (2004) reflecting both low LET bystander and adaptive response effects. The micro-beam facility data of Miller et al (1999), Nagasawa and Little (1999) and Zhou et al (2003) is also examined. For the Zhou et al (2003) data, we use the AR-BE model to estimate the threshold for adaptive response reduction of the bystander effect. The mammogram and diagnostic X-ray induction of AR and protective BE are observed. We show that bystander damage is reduced in the similar manner as spontaneous and challenge dose damage as shown by the Azzam et al (1996) data. We cite primary unresolved questions regarding adaptive response behavior and bystander behavior. The five features of major significance provided by the Microdose Model so far are 1. Single Specific Energy Hits initiate Adaptive Response. 2. Mammogram and diagnostic X-rays induce a protective Bystander Effect as well as Adaptive Response radio-protection. 3. For mammogram X-rays the Adaptive Response protection is retained at high primer dose levels. 4. The dose range of the AR protection depends on the value of the Specific Energy per Hit, 1 >. 5. Alpha particle induced deleterious Bystander damage is modulated by low LET radiation.

Bystander Intervention Prior to The Arrival of Emergency Medical Services: Comparing Assistance across Types of Medical Emergencies.

PubMed

Faul, Mark; Aikman, Shelley N; Sasser, Scott M

2016-01-01

To determine the situational circumstances associated with bystander interventions to render aid during a medical emergency. This study examined 16.2 million Emergency Medical Service (EMS) events contained within the National Emergency Medical Services Information System. The records of patients following a 9-1-1 call for emergency medical assistance were analyzed using logistic regression to determine what factors influenced bystander interventions. The dependent variable of the model was whether or not a bystander intervened. EMS providers recorded bystander assistance 11% of the time. The logistic regression model correctly predicted bystander intervention occurrence 71.4% of the time. Bystanders were more likely to intervene when the patient was male (aOR = 1.12, 95% CI = 1.12-1.3) and if the patient was older (progressive aOR = 1.10, 1.46 age group 20-29 through age group 60-99). Bystanders were less likely to intervene in rural areas compared to urban areas (aOR = 0.58, 95% CI = 0.58-0.59). The highest likelihood of bystander intervention occurred in a residential institution (aOR = 1.86, 95% CI = 1.85-1.86) and the lowest occurred on a street or a highway (aOR = 0.96, 95% CI = 0.95-0.96). Using death as a reference group, bystanders were most likely to intervene when the patient had cardiac distress/chest pain (aOR = 11.38, 95% CI = 10.93-11.86), followed by allergic reaction (aOR = 7.63, 95% CI = 7.30-7.99), smoke inhalation (aOR = 6.65, 95% CI = 5.98-7.39), and respiration arrest/distress (aOR = 6.43, 95% CI = 6.17-6.70). A traumatic injury was the most commonly recorded known event, and it was also associated with a relatively high level of bystander intervention (aOR = 5.81, 95% CI = 5.58-6.05). The type of injury/illness that prompted the lowest likelihood of bystander assistance was Sexual Assault/Rape (aOR = 1.57, 95% CI = 1.32-1.84) followed by behavioral/psychiatric disorder (aOR = 1.64, 95% CI = 1.57-1.71). Bystander intervention varies greatly on situational factors and the type of medical emergency. A higher risk of patient death is likely to prompt bystander action. These novel study results can lead to more effective first aid training programs. bystander; EMS; rural; cardiac distress; trauma.

Radiation-induced genomic instability and bystander effects: related inflammatory-type responses to radiation-induced stress and injury? A review.

PubMed

Lorimore, S A; Wright, E G

2003-01-01

To review studies of radiation responses in the haemopoietic system in the context of radiation-induced genomic instability, bystander effects and inflammatory-type processes. There is considerable evidence that cells that themselves are not exposed to ionizing radiation but are the progeny of cells irradiated many cell divisions previously may express a high frequency of gene mutations, chromosomal aberrations and cell death. These effects are collectively known as radiation-induced genomic instability. A second untargeted effect results in non-irradiated cells exhibiting responses typically associated with direct radiation exposure but occurs as a consequence of contact with irradiated cells or by receiving soluble signals from irradiated cells. These effects are collectively known as radiation-induced bystander effects. Reported effects include increases or decreases in damage-inducible and stress-related proteins; increases or decreases in reactive oxygen species, cell death or cell proliferation, and induction of mutations and chromosome aberrations. This array of responses is reminiscent of effects mediated by cytokines and other similar regulatory factors that may involve, but do not necessarily require, gap junction-mediated transfer, have multiple inducers and a variety of context-dependent consequences in different cell systems. That chromosomal instability in haemopoietic cells can be induced by an indirect bystander-type mechanism both in vitro and in vivo provides a potential link between these two untargeted effects and there are radiation responses in vivo consistent with the microenvironment contributing secondary cell damage as a consequence of an inflammatory-type response to radiation-induced injury. Intercellular signalling, production of cytokines and free radicals are features of inflammatory responses that have the potential for both bystander-mediated and persisting damage as well as for conferring a predisposition to malignancy. The induction of bystander effects and instabilities may reflect interrelated aspects of a non-specific inflammatory-type response to radiation-induced stress and injury and be involved in a variety of the pathological consequences of radiation exposures.

Mechanisms and biological importance of photon-induced bystander responses: do they have an impact on low-dose radiation responses

PubMed Central

Tomita, Masanori; Maeda, Munetoshi

2015-01-01

Abstract Elucidating the biological effect of low linear energy transfer (LET), low-dose and/or low-dose-rate ionizing radiation is essential in ensuring radiation safety. Over the past two decades, non-targeted effects, which are not only a direct consequence of radiation-induced initial lesions produced in cellular DNA but also of intra- and inter-cellular communications involving both targeted and non-targeted cells, have been reported and are currently defining a new paradigm in radiation biology. These effects include radiation-induced adaptive response, low-dose hypersensitivity, genomic instability, and radiation-induced bystander response (RIBR). RIBR is generally defined as a cellular response that is induced in non-irradiated cells that receive bystander signals from directly irradiated cells. RIBR could thus play an important biological role in low-dose irradiation conditions. However, this suggestion was mainly based on findings obtained using high-LET charged-particle radiations. The human population (especially the Japanese, who are exposed to lower doses of radon than the world average) is more frequently exposed to low-LET photons (X-rays or γ-rays) than to high-LET charged-particle radiation on a daily basis. There are currently a growing number of reports describing a distinguishing feature between photon-induced bystander response and high-LET RIBR. In particular, photon-induced bystander response is strongly influenced by irradiation dose, the irradiated region of the targeted cells, and p53 status. The present review focuses on the photon-induced bystander response, and discusses its impact on the low-dose radiation effect. PMID:25361549

BYSTANDER EFFECTS GENOMIC INSTABILITY, ADAPTIVE RESPONSE AND CANCER RISK ASSESSMENT FOR RADIAION AND CHEMICAL EXPOSURES

EPA Science Inventory

BYSTANDER EFFECTS, GENOMIC INSTABILITY, ADAPTIVE RESPONSE AND CANCER RISK ASSESSMENT FOR RADIATION AND CHEMICAL EXPOSURES

R. Julian Preston
Environmental Carcinogenesis Division, U.S. Environmental Protection Agency, Research Triangle Park, N.C. 27711, USA

There ...

Propagation Distance of the α-Particle-Induced Bystander Effect: The Role of Nuclear Traversal and Gap Junction Communication

PubMed Central

Gaillard, Sylvain; Pusset, David; de Toledo, Sonia M.; Fromm, Michel; Azzam, Edouard I.

2009-01-01

When cell populations are exposed to low-dose α-particle radiation, a significant fraction of the cells will not be traversed by a radiation track. However, stressful effects occur in both irradiated and bystander cells in the population. Characterizing these effects, and investigating their underlying mechanism(s), is critical to understanding human health risks associated with exposure to α particles. To this end, confluent normal human fibroblast cultures were grown on polyethylene terephthalate foil grafted to an ultrathin solid-state nuclear track detector and exposed under non-perturbing conditions to low-fluence α particles from a broadbeam irradiator. Irradiated and affected bystander cells were localized with micrometer precision. The stress-responsive protein p21Waf1 (also known as CDKN1A) was induced in bystander cells within a 100-µm radius from an irradiated cell. The mean propagation distance ranged from 20 to 40 µm around the intranuclear α-particle impact point, which corresponds to a set of ∼30 cells. Nuclear traversal, induced DNA damage, and gap junction communication were critical contributors to propagation of this stressful effect The strategy described here may be ideal to investigate the size of radiation-affected target and the relative contribution of different cellular organelles to bystander effects induced by energetic particles, which is relevant to radioprotection and cancer radiotherapy. PMID:19580486

Selective replication of oncolytic virus M1 results in a bystander killing effect that is potentiated by Smac mimetics.

PubMed

Cai, Jing; Lin, Yuan; Zhang, Haipeng; Liang, Jiankai; Tan, Yaqian; Cavenee, Webster K; Yan, Guangmei

2017-06-27

Oncolytic virotherapy is a treatment modality that uses native or genetically modified viruses that selectively replicate in and kill tumor cells. Viruses represent a type of pathogen-associated molecular pattern and thereby induce the up-regulation of dozens of cytokines via activating the host innate immune system. Second mitochondria-derived activator of caspases (Smac) mimetic compounds (SMCs), which antagonize the function of inhibitor of apoptosis proteins (IAPs) and induce apoptosis, sensitize tumor cells to multiple cytokines. Therefore, we sought to determine whether SMCs sensitize tumor cells to cytokines induced by the oncolytic M1 virus, thus enhancing a bystander killing effect. Here, we report that SMCs potentiate the oncolytic effect of M1 in vitro, in vivo, and ex vivo. This strengthened oncolytic efficacy resulted from the enhanced bystander killing effect caused by the M1 virus via cytokine induction. Through a microarray analysis and subsequent validation using recombinant cytokines, we identified IL-8, IL-1A, and TRAIL as the key cytokines in the bystander killing effect. Furthermore, SMCs increased the replication of M1, and the accumulation of virus protein induced irreversible endoplasmic reticulum stress- and c-Jun N-terminal kinase-mediated apoptosis. Nevertheless, the combined treatment with M1 and SMCs had little effect on normal and human primary cells. Because SMCs selectively and significantly enhance the bystander killing effect and the replication of oncolytic virus M1 specifically in cancer cells, this combined treatment may represent a promising therapeutic strategy.

Are nonparticipants in prosocial behavior merely innocent bystanders?

PubMed

Anker, Ashley E; Feeley, Thomas Hugh

2011-01-01

Latané and Darley's (1970) bystander intervention theory was used to model individuals' participation in two prosocial behaviors (organ donation, green living). It is argued that nonparticipants in prosocial helping are innocent bystanders who likely fail to notice the need, do not interpret the cause as an emergency, do not accept responsibility for the need to help, and have little knowledge on how to help. Data in study 1 (n = 494) indicate support for the proposed innocent bystander path model (notice event → interpret event as emergency → accept responsibility → knowledge of how to help) in organ donation. Study 2 (n = 519) replicated the model in the context of green living and additionally found a direct path from noticing the event to knowledge of how to help. Implications of framing nonparticipation in prosocial behaviors as innocent bystander effects are discussed in context of campaign communication.

No significant level of inheritable interchromosomal aberrations in the progeny of bystander primary human fibroblasts after alpha particle irradiation

NASA Astrophysics Data System (ADS)

Hu, Burong; Zhu, Jiayun; Zhou, Hongning; Hei, Tom K.

2013-02-01

A major concern for bystander effects is the probability that normal healthy cells adjacent to the irradiated cells become genomically unstable and undergo further carcinogenesis after therapeutic irradiation or space mission where astronauts are exposed to low dose of heavy ions. Genomic instability is a hallmark of cancer cells. In the present study, two irradiation protocols were performed in order to ensure pure populations of bystander cells and the genomic instability in their progeny were investigated. After irradiation, chromosomal aberrations of cells were analyzed at designated time points using G2 phase premature chromosome condensation (G2-PCC) coupled with Giemsa staining and with multiplex fluorescent in situ hybridization (mFISH). Our Giemsa staining assay demonstrated that elevated yields of chromatid breaks were induced in the progeny of pure bystander primary fibroblasts up to 20 days after irradiation. mFISH assay showed no significant level of inheritable interchromosomal aberrations were induced in the progeny of the bystander cell groups, while the fractions of gross aberrations (chromatid breaks or chromosomal breaks) significantly increased in some bystander cell groups. These results suggest that genomic instability occurred in the progeny of the irradiation associated bystander normal fibroblasts exclude the inheritable interchromosomal aberration.

No significant level of inheritable interchromosomal aberrations in the progeny of bystander primary human fibroblast after alpha particle irradiation.

PubMed

Hu, Burong; Zhu, Jiayun; Zhou, Hongning; Hei, Tom K

2013-02-01

A major concern for bystander effects is the probability that normal healthy cells adjacent to the irradiated cells become genomically unstable and undergo further carcinogenesis after therapeutic irradiation or space mission where astronauts are exposed to low dose of heavy ions. Genomic instability is a hallmark of cancer cells. In the present study, two irradiation protocols were performed in order to ensure pure populations of bystander cells and the genomic instability in their progeny were investigated. After irradiation, chromosomal aberrations of cells were analyzed at designated time points using G 2 phase premature chromosome condensation (G 2 -PCC) coupled with Giemsa staining and with multiplex fluorescent in situ hybridization (mFISH). Our Giemsa staining assay demonstrated that elevated yields of chromatid breaks were induced in the progeny of pure bystander primary fibroblasts up to 20 days after irradiation. MFISH assay showed no significant level of inheritable interchromosomal aberrations were induced in the progeny of the bystander cell groups, while the fractions of gross aberrations (chromatid breaks or chromosomal breaks) significantly increased in some bystander cell groups. These results suggest that genomic instability occurred in the progeny of the irradiation associated bystander normal fibroblasts exclude the inheritable interchromosomal aberration.

Bystander Intervention Prior to The Arrival of Emergency Medical Services: Comparing Assistance across Types of Medical Emergencies

PubMed Central

Faul, Mark; Aikman, Shelley N.; Sasser, Scott M.

2016-01-01

Objective To determine the situational circumstances associated with bystander interventions to render aid during a medical emergency. Methods This study examined 16.2 million Emergency Medical Service (EMS) events contained within the National Emergency Medical Services Information System. The records of patients following a 9-1-1 call for emergency medical assistance were analyzed using logistic regression to determine what factors influenced bystander interventions. The dependent variable of the model was whether or not a bystander intervened. Results EMS providers recorded bystander assistance 11% of the time. The logistic regression model correctly predicted bystander intervention occurrence 71.4% of the time. Bystanders were more likely to intervene when the patient was male (aOR = 1.12, 95% CI = 1.12–1.3) and if the patient was older (progressive aOR = 1.10, 1.46 age group 20–29 through age group 60–99). Bystanders were less likely to intervene in rural areas compared to urban areas (aOR = 0.58, 95% CI = 0.58–0.59). The highest likelihood of bystander intervention occurred in a residential institution (aOR = 1.86, 95% CI = 1.85–1.86) and the lowest occurred on a street or a highway (aOR = 0.96, 95% CI = 0.95–0.96). Using death as a reference group, bystanders were most likely to intervene when the patient had cardiac distress/chest pain (aOR = 11.38, 95% CI = 10.93–11.86), followed by allergic reaction (aOR = 7.63, 95% CI = 7.30–7.99), smoke inhalation (aOR = 6.65, 95% CI = 5.98–7.39), and respiration arrest/distress (aOR = 6.43, 95% CI = 6.17–6.70). A traumatic injury was the most commonly recorded known event, and it was also associated with a relatively high level of bystander intervention (aOR = 5.81, 95% CI = 5.58–6.05). The type of injury/illness that prompted the lowest likelihood of bystander assistance was Sexual Assault/Rape (aOR = 1.57, 95% CI = 1.32–1.84) followed by behavioral/psychiatric disorder (aOR = 1.64, 95% CI = 1.57–1.71). Conclusion Bystander intervention varies greatly on situational factors and the type of medical emergency. A higher risk of patient death is likely to prompt bystander action. These novel study results can lead to more effective first aid training programs. PMID:26807490

Prodrugs for Gene-Directed Enzyme-Prodrug Therapy (Suicide Gene Therapy)

PubMed Central

2003-01-01

This review focuses on the prodrugs used in suicide gene therapy. These prodrugs need to satisfy a number of criteria. They must be efficient and selective substrates for the activating enzyme, and be metabolized to potent cytotoxins preferably able to kill cells at all stages of the cell cycle. Both prodrugs and their activated species should have good distributive properties, so that the resulting bystander effects can maximize the effectiveness of the therapy, since gene transduction efficiencies are generally low. A total of 42 prodrugs explored for use in suicide gene therapy with 12 different enzymes are discussed, particularly in terms of their physiocochemical properties. An important parameter in determining bystander effects generated by passive diffusion is the lipophilicity of the activated form, a property conveniently compared by diffusion coefficients (log P for nonionizable compounds and log D7 for compounds containing an ionizable centre). Many of the early antimetabolite-based prodrugs provide very polar activated forms that have limited abilities to diffuse across cell membranes, and rely on gap junctions between cells for their bystander effects. Several later studies have shown that more lipophilic, neutral compounds have superior diffusion-based bystander effects. Prodrugs of DNA alkylating agents, that are less cell cycle-specific than antimetabolites and more effective against noncycling tumor cells, appear in general to be more active prodrugs, requiring less prolonged dosing schedules to be effective. It is expected that continued studies to optimize the bystander effects and other properties of prodrugs and the activated species they generate will contribute to improvements in the effectiveness of suicide gene therapy. PMID:12686722

Low-dose non-targeted radiation effects in human esophageal adenocarcinoma cell lines.

PubMed

Hanu, Christine; Wong, Raimond; Sur, Ranjan K; Hayward, Joseph E; Seymour, Colin; Mothersill, Carmel

2017-02-01

To investigate non-targeted radiation effects in esophageal adenocarcinoma cell lines (OE19 and OE33) using human keratinocyte and colorectal cancer cell reporters following γ-ray exposure. Both clonogenic assays and ratiometric calcium endpoints were used to check for the occurrence of bystander signals in reporter cells. We report data suggesting that γ-irradiation increases cell killing over the expected linear quadratic (LQ) model levels in the OE19 cell line exposed to doses below 1 Gy, i.e. which may be suggestive to be a low hyper-radiosensitive (HRS) response to direct irradiation. Both EAC cell lines (OE19 and OE33) have the ability to produce bystander signals when irradiated cell conditioned medium (ICCM) is placed onto human keratinocyte reporters, but do not seem to be capable of responding to bystander signals when placed on their autologous reporters. Further work with human keratinocyte reporter models showed statistically significant intracellular calcium fluxes following exposure of the reporters to ICCM harvested from both EAC cell lines exposed to 0.5 Gy. These experiments suggest that the OE19 and OE33 cell lines produce bystander signals in human keratinocyte reporter cells. However, the radiosensitivity of the EAC cell lines used in this study cannot be enhanced by the bystander response since both cell lines could not respond to bystander signals.

Beyond Yes or No: Understanding Undergraduate Students' Responses as Bystanders to Sexual Assault Risk Situations.

PubMed

Hoxmeier, Jill C; McMahon, Sarah; O'Connor, Julia

2017-08-01

The White House Task Force to Protect Students From Sexual Assault recommends bystander engagement programming as part of campus sexual assault prevention efforts. Measuring students' bystander behavior, and thus, assessing the effectiveness of such programming, is a challenging endeavor due to the range of risk situations students may witness, as well as the nuances in potential barriers students may face in these situations. Currently, many studies include dichotomous measures of bystander behavior without gathering further information about students' opportunities to intervene, barriers to intervening, and intervention strategies. The current study sought to implement a more comprehensive approach to understanding the types of sexual assault risk situations students report to witness, as well as their response in those situations, reasons for not intervening, and any gender differences therein. In 2014, undergraduate students ( n = 9,358) at a large, public university in the Northeast completed a web-based survey to assess bystander opportunities and responses for six different risk situations. Results show that prosocial bystander responses varied depending on the risk situation. Of those students with opportunities to intervene, noninterveners reported the situation was "none of their business" or that they were "unsure of what to do." Interveners reported to have either "confronted the situation directly" or "went and got assistance." We also observed significant gender differences in students' reported intervention opportunities and bystander responses. The findings of this study have several important implications for bystander engagement programming and future research.

Do Sexual Assault Bystander Interventions Change Men's Intentions? Applying the Theory of Normative Social Behavior to Predicting Bystander Outcomes.

PubMed

Mabry, Amanda; Turner, Monique Mitchell

2016-01-01

The high prevalence of sexual assault on college campuses has led to the implementation of health communication programs to prevent sexual assault. A few novel programs focus on primary prevention by targeting social norms related to gender and masculinity among men through bystander intervention. Guided by the theory of normative social behavior, this study sought to examine the relative effect of campaigns communicating positive versus negative injunctive norms and the interaction between exposure to such campaign messages and perceived descriptive norms and relevant cognitive moderators (e.g., outcome expectations, injunctive norms, group identity, ego involvement) among men. A 2 (high/low descriptive norms) × 2 (high/low moderator) × 3 (public service announcement) independent groups quasi-experimental design (N = 332) was used. Results indicated that messages communicating positive injunctive norms were most effective among men who were least likely to engage in bystander intervention. Furthermore, descriptive norms played a significant role in behavioral intentions, such that those with stronger norms were more likely to report intentions to engage in bystander behaviors in the future. Similarly, the moderators of aspiration, injunctive norms, social approval, and ego involvement had a significant positive effect on behavioral intentions. These findings have important implications for future message design strategy and audience segmentation.

A Review: Development of a Microdose Model for Analysis of Adaptive Response and Bystander Dose Response Behavior

PubMed Central

Leonard, Bobby E.

2008-01-01

Prior work has provided incremental phases to a microdosimetry modeling program to describe the dose response behavior of the radio-protective adaptive response effect. We have here consolidated these prior works (Leonard 2000, 2005, 2007a, 2007b, 2007c) to provide a composite, comprehensive Microdose Model that is also herein modified to include the bystander effect. The nomenclature for the model is also standardized for the benefit of the experimental cellular radio-biologist. It extends the prior work to explicitly encompass separately the analysis of experimental data that is 1.) only dose dependent and reflecting only adaptive response radio-protection, 2.) both dose and dose-rate dependent data and reflecting only adaptive response radio-protection for spontaneous and challenge dose damage, 3.) only dose dependent data and reflecting both bystander deleterious damage and adaptive response radio-protection (AR-BE model). The Appendix cites the various applications of the model. Here we have used the Microdose Model to analyze the, much more human risk significant, Elmore et al (2006) data for the dose and dose rate influence on the adaptive response radio-protective behavior of HeLa x Skin cells for naturally occurring, spontaneous chromosome damage from a Brachytherapy type 125I photon radiation source. We have also applied the AR-BE Microdose Model to the Chromosome inversion data of Hooker et al (2004) reflecting both low LET bystander and adaptive response effects. The micro-beam facility data of Miller et al (1999), Nagasawa and Little (1999) and Zhou et al (2003) is also examined. For the Zhou et al (2003) data, we use the AR-BE model to estimate the threshold for adaptive response reduction of the bystander effect. The mammogram and diagnostic X-ray induction of AR and protective BE are observed. We show that bystander damage is reduced in the similar manner as spontaneous and challenge dose damage as shown by the Azzam et al (1996) data. We cite primary unresolved questions regarding adaptive response behavior and bystander behavior. The five features of major significance provided by the Microdose Model so far are 1.) Single Specific Energy Hits initiate Adaptive Response, 2.) Mammogram and diagnostic X-rays induce a protective Bystander Effect as well as Adaptive Response radio-protection. 3.) For mammogram X-rays the Adaptive Response protection is retained at high primer dose levels. 4.) The dose range of the AR protection depends on the value of the Specific Energy per Hit, . 5.) Alpha particle induced deleterious Bystander damage is modulated by low LET radiation. PMID:18648579

Photon hormesis deactivates alpha-particle induced bystander effects between zebrafish embryos

NASA Astrophysics Data System (ADS)

Ng, C. Y. P.; Cheng, S. H.; Yu, K. N.

2017-04-01

In the present work, we studied the effects of low-dose X-ray photons on the alpha-particle induced bystander effects between embryos of the zebrafish, Danio rerio. The effects on the naive whole embryos were studied through quantification of apoptotic signals (amounts of cells undergoing apoptosis) at 24 h post fertilization (hpf) using vital dye acridine orange staining, followed by counting the stained cells under a fluorescent microscope. We report data showing that embryos at 5 hpf subjected to a 4.4 mGy alpha-particle irradiation could release a stress signal into the medium, which could induce bystander effect in partnered naive embryos sharing the same medium. We also report that the bystander effect was deactivated when the irradiated embryos were subjected to a concomitant irradiation of 10 or 14 mGy of X-rays, but no such deactivation was achieved if the concomitant X-ray dose dropped to 2.5 or 5 mGy. In the present study, the significant drop in the amount of apoptotic signals on the embryos having received 4.4 mGy alpha particles together X-rays irradiation from 2.5 or 5 mGy to 10 or 14 mGy, together with the deactivation of RIBE with concomitant irradiation of 10 or 14 mGy of X-rays supported the participation of photon hormesis with an onset dose between 5 and 10 mGy, which might lead to removal of aberrant cells through early apoptosis or induction of high-fidelity DNA repair. As we found that photons and alpha particles could have opposite biological effects when these were simultaneously irradiated onto living organisms, these ionizing radiations could be viewed as two different environmental stressors, and the resultant effects could be regarded as multiple stressor effects. The present work presented the first study on a multiple stressor effect which occurred on bystander organisms. In other words, this was a non-targeted multiple stressor effect. The photon hormesis could also explain some failed attempts to observe neutron-induced bystander effects in previous studies, as neutron sources invariably emit neutrons with concomitant gamma-ray photons, which is often referred to as gamma-ray contamination.

Cyberbullying Among Adolescent Bystanders: Role of Affective Versus Cognitive Empathy in Increasing Prosocial Cyberbystander Behavior.

PubMed

Barlińska, Julia; Szuster, Anna; Winiewski, Mikołaj

2018-01-01

The purpose of this study was to investigate if affective (vicarious sharing of emotions) and cognitive empathy (mental perspective taking) induction may stimulate adolescent online bystanders' intervention in cyberbullying cases. The role of reporting the abuse is crucial because it is a form of active support to the victim, initiated by children, to stop the bullying. The effectiveness of empathy activation in decreasing negative cyberbystander reinforcing behavior has been proved in previous studies. The effects of affective and cognitive empathy activation on positive cyberbystander behavior, defined as reporting the bullying online, were explored in two follow-up studies N = 271 and N = 265. The influence of experiencing cyberbullying as perpetrator, victim, and as determined by gender on prosocial cyberbystander behavior was also controlled. The results indicate that only cognitive empathy activation increases the likelihood of intervening bystander behavior. Neither affective empathy induction, previous experience of cyberperpetration, cybervictimization, nor gender affected the engagement in prosocial bystander behavior. The conclusion of the research is that a program consequently activating more reflective cognitive empathy induction can contribute toward the establishment of healthier behavioral patterns among bystanders to cyberbullying, increasing the probability of their reporting the cyberbullying acts.

Masculinity and Bystander Attitudes: Moderating Effects of Masculine Gender Role Stress.

PubMed

Leone, Ruschelle M; Parrott, Dominic J; Swartout, Kevin M; Tharp, Andra Teten

2016-01-01

The purpose of the current study was to examine the bystander decision-making process as a mechanism by which men's adherence to various dimensions of traditional masculinity is associated with their confidence to intervene in sexually aggressive events. Further, this study examined the stress men experience from their attempts to adhere to traditional male gender roles as a moderator of this mediational path. Participants ( n = 252) completed measures of traditional masculinity, decisional balance (i.e., weighing the pros and cons) for intervening, masculine gender roles stress, and bystander efficacy. The belief that men must attain social status was associated with more confidence in men's ability to intervene. This effect was mediated by greater perceived positive consequences for intervention among men high, but not low, in masculine gender role stress. The belief that men should be tough and aggressive was associated with greater perceived negative consequences for intervention and less confidence to intervene. The belief that men should not act in stereotypically feminine ways was directly associated with less confidence for intervention. Findings highlight the importance of examining masculinity from a multidimensional perspective to better understand how adherence to various norms differentially influences bystander behavior. These findings may help to inform bystander intervention programming.

Damage of chromosoms under irradiation of human blood lymphocytes and development of bystander effect.

PubMed

Shemetun, O V

2016-12-01

the research the distribution of radiation induced damages among chromosomes and their bands in irra diated in vitro human blood lymphocytes and in unirradiated bystander cells.Material and methods of research: cultivation of human peripheral blood lymphocytes by semi micromethod D.A. Hungerford, modeling of radiation induced bystander effect in mixed cultures consisting of irradiated in vitro and non irradiated blood lymphocytes from persons of different gender, GTG staining of metaphase chromosomes and their cytogenetic analysis. Break points in chromosomes under the formation of aberrations were identified in exposed in vitro human peripheral blood lymphocytes in doses 0.25 Gy (95 breaks in 1248 cells) and 1.0 Gy (227 breaks in 726 cells) and in non irradiated bystander cells under their joint cultivation with irradiated in vitro human lymphocytes (51 breaks in 1137 cells at irradiation of adjacent populations of lymphocytes in dose 0.25 Gy and 75 breaks in 1321 cells at irradiation of adjacent population of lymphocytes in a dose 1.0 Gy). The distribution of injuries among the chromo somes and their bands was investigated. in radiation exposed in vitro human peripheral blood lymphocytes as well as in bystander cells the fre quency of damaged bands and number of breaks which localized in them exceeded the control value (p < 0.01). As under direct radiation exposure, as under formation of breaks due to induction of bystander effect, chromosomes were damaged according to their relative length. Location of bands with increasing number of breaks coincided with the «hot spots» of chromosome damage following irradiation and fragile sites. More sensitive to damage were G negative euchromatin chromosome bands, in which were localized 82 88 % breaks. Damageability of telomeric regions in the irradiated cells had no significant difference from the control, while in bystander cells was lower than control value (p < 0.05). O. V. Shemetun.

Blame Conformity: Innocent Bystanders Can Be Blamed for a Crime as a Result of Misinformation from a Young, but Not Elderly, Adult Co-Witness

PubMed Central

Thorley, Craig

2015-01-01

This study examined whether or not exposing an eyewitness to a co-witness statement that incorrectly blames an innocent bystander for a crime can increase the likelihood of the eyewitness subsequently blaming the innocent bystander for the crime. It also examined whether or not the perceived age of the co-witness influences this effect. Participant eyewitnesses first watched a video of a crime featuring a perpetrator and an innocent bystander. They then read one of six bogus co-witness statements about the crime. All were presented as having been written by a female co-witness and they differed in terms of her age (young adult or elderly) and who she blamed for the crime (the perpetrator, the innocent bystander, or nobody). One week later the participants were asked who committed the crime. When the young adult co-witness had blamed the innocent bystander just over 40% of participants subsequently did the same. Few participants (less than 8%) in the other conditions subsequently blamed the innocent bystander. The elderly co-witness was also rated as less credible, less competent, and less accurate than the younger co-witness suggesting eyewitnesses were less likely to be influenced by her incorrect statement as they perceived her to be a less reliable source of information. The applied implications of these findings are discussed. PMID:26230523

Blame Conformity: Innocent Bystanders Can Be Blamed for a Crime as a Result of Misinformation from a Young, but Not Elderly, Adult Co-Witness.

PubMed

Thorley, Craig

2015-01-01

This study examined whether or not exposing an eyewitness to a co-witness statement that incorrectly blames an innocent bystander for a crime can increase the likelihood of the eyewitness subsequently blaming the innocent bystander for the crime. It also examined whether or not the perceived age of the co-witness influences this effect. Participant eyewitnesses first watched a video of a crime featuring a perpetrator and an innocent bystander. They then read one of six bogus co-witness statements about the crime. All were presented as having been written by a female co-witness and they differed in terms of her age (young adult or elderly) and who she blamed for the crime (the perpetrator, the innocent bystander, or nobody). One week later the participants were asked who committed the crime. When the young adult co-witness had blamed the innocent bystander just over 40% of participants subsequently did the same. Few participants (less than 8%) in the other conditions subsequently blamed the innocent bystander. The elderly co-witness was also rated as less credible, less competent, and less accurate than the younger co-witness suggesting eyewitnesses were less likely to be influenced by her incorrect statement as they perceived her to be a less reliable source of information. The applied implications of these findings are discussed.

Leverage Between the Buffering Effect and the Bystander Effect in Social Networking.

PubMed

Chiu, Yu-Ping; Chang, Shu-Chen

2015-08-01

This study examined encouraged and inhibited social feedback behaviors based on the theories of the buffering effect and the bystander effect. A system program was used to collect personal data and social feedback from a Facebook data set to test the research model. The results revealed that the buffering effect induced a positive relationship between social network size and feedback gained from friends when people's social network size was under a certain cognitive constraint. For people with a social network size that exceeds this cognitive constraint, the bystander effect may occur, in which having more friends may inhibit social feedback. In this study, two social psychological theories were applied to explain social feedback behavior on Facebook, and it was determined that social network size and social feedback exhibited no consistent linear relationship.

Bystander first aid in trauma - prevalence and quality: a prospective observational study.

PubMed

Bakke, H K; Steinvik, T; Eidissen, S-I; Gilbert, M; Wisborg, T

2015-10-01

Bystander first aid and basic life support can likely improve victim survival in trauma. In contrast to bystander first aid and out-of-hospital cardiac arrest, little is known about the role of bystanders in trauma response. Our aim was to determine how frequently first aid is given to trauma victims by bystanders, the quality of this aid, the professional background of first-aid providers, and whether previous first-aid training affects aid quality. We conducted a prospective 18-month study in two mixed urban-rural Norwegian counties. The personnel on the first ambulance responding to trauma calls assessed and documented first aid performed by bystanders using a standard form. A total of 330 trauma calls were included, with bystanders present in 97% of cases. Securing an open airway was correctly performed for 76% of the 43 patients in need of this first-aid measure. Bleeding control was provided correctly for 81% of 63 patients for whom this measure was indicated, and prevention of hypothermia for 62% of 204 patients. Among the first-aid providers studied, 35% had some training in first aid. Bystanders with documented first-aid training gave better first aid than those where first-aid training status was unknown. A majority of the trauma patients studied received correct pre-hospital first aid, but still there is need for considerable improvement, particularly hypothermia prevention. Previous first-aid training seems to improve the quality of first aid provided. The effect on patient survival needs to be investigated. © 2015 The Authors. The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

A Meta-Analysis of School-Based Bullying Prevention Programs' Effects on Bystander Intervention Behavior

ERIC Educational Resources Information Center

Polanin, Joshua R.; Espelage, Dorothy L.; Pigott, Therese D.

2012-01-01

This meta-analysis synthesized bullying prevention programs' effectiveness at increasing bystander intervention in bullying situations. Evidence from 12 school-based programs, involving 12,874 students, indicated that overall the programs were successful (Hedges's g = 0.20, 95% confidence interval [CI] = 0.11 to 0.29, p = 0.001), with larger…

Collective helping and bystander effects in coevolving helping networks.

PubMed

Jo, Hang-Hyun; Lee, Hyun Keun; Park, Hyunggyu

2010-06-01

We study collective helping behavior and bystander effects in a coevolving helping network model. A node and a link of the network represents an agent who renders or receives help and a friendly relation between agents, respectively. A helping trial of an agent depends on relations with other involved agents and its result (success or failure) updates the relation between the helper and the recipient. We study the network link dynamics and its steady states analytically and numerically. The full phase diagram is presented with various kinds of active and inactive phases and the nature of phase transitions are explored. We find various interesting bystander effects, consistent with the field study results, of which the underlying mechanism is proposed.

Bystander effects of ionizing radiation can be modulated by signaling amines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poon, R.C.C.; Agnihotri, N.; Seymour, C.

2007-10-15

Actual risk and risk management of exposure to ionizing radiation are among the most controversial areas in environmental health protection. Recent developments in radiobiology especially characterization of bystander effects have called into question established dogmas and are thought to cast doubt on the scientific basis of the risk assessment framework, leading to uncertainty for regulators and concern among affected populations. In this paper we test the hypothesis that small signaling molecules widely used throughout the animal kingdom for signaling stress or environmental change, such as 5-Hydroxytryptamine (5-HT, serotonin), L-DOPA, glycine or nicotine are involved in bystander signaling processes following ionizingmore » radiation exposure. We report data which suggest that nano to micromolar concentrations of these agents can modulate bystander-induced cell death. Depletion of 5-HT present in tissue culture medium, occurred following irradiation of cells. This suggested that 5-HT might be bound by membrane receptors after irradiation. Expression of 5-HT type 3 receptors which are Ca{sup 2+} ion channels was confirmed in the cells using immunocytochemistry and receptor expression could be increased using radiation or 5-HT exposure. Zofran and Kitryl, inhibitors of 5-HT type 3 receptors, and reserpine a generic serotonin antagonist block the bystander effect induced by radiation or by serotonin. The results may be important for the mechanistic understanding of how low doses of radiation interact with cells to produce biological effects.« less

Cell cycle tracking for irradiated and unirradiated bystander cells in a single colony with exposure to a soft X-ray microbeam.

PubMed

Kaminaga, Kiichi; Noguchi, Miho; Narita, Ayumi; Hattori, Yuya; Usami, Noriko; Yokoya, Akinari

2016-11-01

To establish a new experimental technique to explore the photoelectric and subsequent Auger effects on the cell cycles of soft X-ray microbeam-irradiated cells and unirradiated bystander cells in a single colony. Several cells located in the center of a microcolony of HeLa-Fucci cells consisting of 20-80 cells were irradiated with soft X-ray (5.35 keV) microbeam using synchrotron radiation as a light source. All cells in the colony were tracked for 72 h by time-lapse microscopy imaging. Cell cycle progression, division, and death of each cell in the movies obtained were analyzed by pedigree assay. The number of cell divisions in the microcolony was also determined. The fates of these cells were clarified by tracking both irradiated and unirradiated bystander cells. Irradiated cells showed significant cell cycle retardation, explosive cell death, or cell fusion after a few divisions. These serious effects were also observed in 15 and 26% of the bystander cells for 10 and 20 Gy irradiation, respectively, and frequently appeared in at least two daughter or granddaughter cells from a single-parent cell. We successfully tracked the fates of microbeam-irradiated cells and unirradiated bystander cells with live cell recordings, which have revealed the dynamics of soft X-ray irradiated and unirradiated bystander cells for the first time. Notably, cell deaths or cell cycle arrests frequently arose in closely related cells. These details would not have been revealed by a conventional immunostaining imaging method. Our approach promises to reveal the dynamic cellular effects of soft X-ray microbeam irradiation and subsequent Auger processes from various endpoints in future studies.

Encouraging responses in sexual and relationship violence prevention: what program effects remain 1 year later?

PubMed

Moynihan, Mary M; Banyard, Victoria L; Cares, Alison C; Potter, Sharyn J; Williams, Linda M; Stapleton, Jane G

2015-01-01

Colleges and universities are high-risk settings for sexual and relationship violence. To address these problems, institutions of higher education have implemented prevention programs, many of which train students as potential bystanders who can step in to help diffuse risky situations, identify and challenge perpetrators, and assist victims. The impact of bystander sexual and relationship violence prevention programs on long-term behavior of bystanders has remained a key unanswered question for those who seek to offer the most effective programs as well as for policy makers. In this study, the researchers experimentally evaluated the effectiveness of the Bringing in the Bystander® in-person program. Participants were 948 1st-year college students of whom 47.8% were women and 85.2% identified as White (15% also identified as Hispanic in a separate question) between the ages of 18 and 24 at two universities (one a rural, primarily residential campus and the other an urban, highly commuter campus) in the northeastern United States. To date, this is the first study to have found positive behavior changes as long-lasting as 1 year following an educational workshop focusing on engaging bystanders in preventing sexual and relationship violence. Even so, many questions remain to be answered about prevention and intervention of this type. More prospective research is needed on bystander-focused prevention of these forms of violence to help understand and better predict the complicated relationships both between and among the attitudes and behaviors related to preventing sexual and relationship violence. In this regard, we make specific recommendations for designing and evaluating programs based on our findings relating to the importance of moderators, especially two key understudied ones, readiness to help and opportunity to intervene. © The Author(s) 2014.

Bystander motivation in bullying incidents: to intervene or not to intervene?

PubMed

Thornberg, Robert; Tenenbaum, Laura; Varjas, Kris; Meyers, Joel; Jungert, Tomas; Vanegas, Gina

2012-08-01

This research sought to extend knowledge about bystanders in bullying situations with a focus on the motivations that lead them to different responses. The 2 primary goals of this study were to investigate the reasons for children's decisions to help or not to help a victim when witnessing bullying, and to generate a grounded theory (or conceptual framework) of bystander motivation in bullying situations. Thirty students ranging in age from 9 to 15 years (M = 11.9; SD = 1.7) from an elementary and middle school in the southeastern United States participated in this study. Open- ended, semi-structured interviews were used, and sessions ranged from 30 to 45 minutes. We conducted qualitative methodology and analyses to gain an in-depth understanding of children's perspectives and concerns when witnessing bullying. A key finding was a conceptual framework of bystander motivation to intervene in bullying situations suggesting that deciding whether to help or not help the victim in a bullying situation depends on how bystanders define and evaluate the situation, the social context, and their own agency. Qualitative analysis revealed 5 themes related to bystander motives and included: interpretation of harm in the bullying situation, emotional reactions, social evaluating, moral evaluating, and intervention self-efficacy. Given the themes that emerged surrounding bystanders' motives to intervene or abstain from intervening, respondents reported 3 key elements that need to be confirmed in future research and that may have implications for future work on bullying prevention. These included: first, the potential importance of clear communication to children that adults expect bystanders to intervene when witnessing bullying; second, the potential of direct education about how bystanders can intervene to increase children's self-efficacy as defenders of those who are victims of bullying; and third, the assumption that it may be effective to encourage children's belief that bullying is morally wrong.

Defending behaviors, bullying roles, and their associations with mental health in junior high school students: a population-based study.

PubMed

Wu, Wen-Chi; Luu, Shyuemeng; Luh, Dih-Ling

2016-10-10

Students should be encouraged to help prevent or stop bullying. However, defending victims of bullying can impact on mental health. It is not only bystanders who may defend victims, but bullies, victims and bully-victims can also have defending behaviors. Nevertheless, most studies of defending behaviors have been limited to an examination of the reactions of bystanders or those not involved in bullying and have ignored the other players. The aim of this study is to investigate the associations between defending behaviors and mental health among bullies, victims, bully-victims and bystanders. Associations among defending behaviors, mental health (including depressive symptoms and social anxiety), and bullying experiences were cross-sectionally examined in 3441 students (13-15 years old.) from 20 randomly selected junior high schools in Taiwan using a self-report questionnaire. SAS 9.3 Survey Analysis procedures were used to conduct descriptive analysis and multiple regression models. Defending behaviors were associated with bullying roles and were higher in victims than in bullies or bystanders. Defending behaviors were positively associated with social anxiety and depressive symptoms. After stratifying by bullying roles, defending behaviors were positively associated with social anxiety in bystanders, and were positively associated with depressive symptoms in victims and bystanders. However, defending behaviors were not significantly associated with mental health indicators in bullies. The associations between defending behaviors and mental health varied according to bullying roles. The results suggest that bystanders and victims experience more mental health effects than bullies. Intervention programs aimed at preventing bullying should focus on strategies that minimize social anxiety and depression in victims and bystanders, and urge students to help vulnerable peers during bullying events.

Reactive oxygen species formation and bystander effects in gradient irradiation on human breast cancer cells.

PubMed

Zhang, Dongqing; Zhou, Tingyang; He, Feng; Rong, Yi; Lee, Shin Hee; Wu, Shiyong; Zuo, Li

2016-07-05

Ionizing radiation (IR) in cancer radiotherapy can induce damage to neighboring cells via non-targeted effects by irradiated cells. These so-called bystander effects remain an area of interest as it may provide enhanced efficacy in killing carcinomas with minimal radiation. It is well known that reactive oxygen species (ROS) are ubiquitous among most biological activities. However, the role of ROS in bystander effects has not been thoroughly elucidated. We hypothesized that gradient irradiation (GI) has enhanced therapeutic effects via the ROS-mediated bystander pathways as compared to uniform irradiation (UI). We evaluated ROS generation, viability, and apoptosis in breast cancer cells (MCF-7) exposed to UI (5 Gy) or GI (8-2 Gy) in radiation fields at 2, 24 and 48 h after IR. We found that extracellular ROS release induced by GI was higher than that by UI at both 24 h (p < 0.001) and 48 h (p < 0.001). More apoptosis and less viability were observed in GI when compared to UI at either 24 h or 48 h after irradiation. The mean effective doses (ED) of GI were ~130% (24 h) and ~48% (48 h) higher than that of UI, respectively. Our results suggest that GI is superior to UI regarding redox mechanisms, ED, and toxic dosage to surrounding tissues.

Masculinity and Bystander Attitudes: Moderating Effects of Masculine Gender Role Stress

PubMed Central

Leone, Ruschelle M.; Parrott, Dominic J.; Swartout, Kevin M.; Tharp, Andra Teten

2018-01-01

Objective The purpose of the current study was to examine the bystander decision-making process as a mechanism by which men’s adherence to various dimensions of traditional masculinity is associated with their confidence to intervene in sexually aggressive events. Further, this study examined the stress men experience from their attempts to adhere to traditional male gender roles as a moderator of this mediational path. Method Participants (n = 252) completed measures of traditional masculinity, decisional balance (i.e., weighing the pros and cons) for intervening, masculine gender roles stress, and bystander efficacy. Results The belief that men must attain social status was associated with more confidence in men’s ability to intervene. This effect was mediated by greater perceived positive consequences for intervention among men high, but not low, in masculine gender role stress. The belief that men should be tough and aggressive was associated with greater perceived negative consequences for intervention and less confidence to intervene. The belief that men should not act in stereotypically feminine ways was directly associated with less confidence for intervention. Conclusions Findings highlight the importance of examining masculinity from a multidimensional perspective to better understand how adherence to various norms differentially influences bystander behavior. These findings may help to inform bystander intervention programming. PMID:29593932

Radiation quality dependence of signal transmission and bystander induced cell killing

NASA Astrophysics Data System (ADS)

Esposito, Giuseppe; Bertolotti, Alessia; Facoetti, Angelica; Grande, Sveva; Mariotti, Luca; Ottolenghi, Andrea; Ranza, Elena; Simone, Giustina; Sorrentino, Eugenio; Antonella Tabocchini, Maria

Low dose radiobiological studies have shown effects, observable in cells that are in the vicinity of irradiated cells, which are due to the release by irradiated cells of several cellular mediators among which Reactive Oxygen and Nitrogen Species (ROS, NRS), and cytokines are likely to play a key role. Despite the large number in the literature of studies on bystander effects induced by ionizing radiation the results are still conflicting, and further studies are therefore needed on the possible underlying mechanisms. The dependence on radiation quality deserve particular attention because bystander mechanisms are probably more important with high-LET irradi-ations, where many cells are not hit (bystander). Moreover, due to the different patterns of energy deposition, the cellular response to low LET and high LET radiation can be different. Understanding whether these cells can contribute to the adverse effects of low radiation doses in a radiation quality-dependent fashion might have important implications in risk estimates for both cancer induction and non-cancer diseases. In this context, we addressed to the study of the bystander induced cell killing after incubation with "conditioned medium" from primary human fibroblasts irradiated with 0.1 and 0.5 Gy of α-particles or γ-rays. Medium transfer was performed after 1h incubation from irradiation. The results have confirmed a reduction in clonogenic survival after incubation with medium from α-irradiated cells, independently of the dose; similar results were obtained after γ-irradiation, although in this case a slight dose depen-dence could be envisaged. Interleukin-6 (IL-6) and Interleukin-8 (IL-8) levels were measured in the conditioned medium collected up to 20 hours after irradiation with α-particles and γ-rays in the dose-range of 0.1-1.0 Gy, in parallel with evaluation of their receptor expression in irradi-ated and bystander cells. Concerning IL-6, we observed the strongest modulation of its release at 20 hours post exposure, whereas IL-8 release was significantly increased at shorter times, i.e. 5-7 hours after irradiation. The expression of their receptors was modulated in both irradiated and bystander cells, although it is not apparently correlated with the relative interleukin re-lease. In order to investigate possible correlation between NRS and cytokines as early and late mediators in the signalling chain leading to bystander induced cell killing, experiments were performed using c-PTIO, a well known scavengers of RNS. In these experiments conditioned medium taken after 1h or 5h from α-particle irradiated cells was used. The results obtained after 5h in the absence of c-PTIO didn't show any further decrease in clonogenic survival of bystander cells. The presence of the scavenger seems to reduce, the bystander induced cell killing indicating that RNS are involved in the transduction of the bystander signal. Experi-ments, performed with both c-PTIO and DMSO, a scavenger of hydroxyl radicals, showed that RNS and ROS play a role in some cytokine pathways (interleukins release and their receptor expression) activated by irradiation. ACKNOWLEDGEMENTS This work was partially supported by the European Commission (EC Contract FP6-36465, "NOTE")

Analysis of the common deletions in the mitochondrial DNA is a sensitive biomarker detecting direct and non-targeted cellular effects of low dose ionizing radiation.

PubMed

Schilling-Tóth, Boglárka; Sándor, Nikolett; Kis, Eniko; Kadhim, Munira; Sáfrány, Géza; Hegyesi, Hargita

2011-11-01

One of the key issues of current radiation research is the biological effect of low doses. Unfortunately, low dose science is hampered by the unavailability of easily performable, reliable and sensitive quantitative biomarkers suitable detecting low frequency alterations in irradiated cells. We applied a quantitative real time polymerase chain reaction (qRT-PCR) based protocol detecting common deletions (CD) in the mitochondrial genome to assess direct and non-targeted effects of radiation in human fibroblasts. In directly irradiated (IR) cells CD increased with dose and was higher in radiosensitive cells. Investigating conditioned medium-mediated bystander effects we demonstrated that low and high (0.1 and 2Gy) doses induced similar levels of bystander responses and found individual differences in human fibroblasts. The bystander response was not related to the radiosensitivity of the cells. The importance of signal sending donor and signal receiving target cells was investigated by placing conditioned medium from a bystander response positive cell line (F11-hTERT) to bystander negative cells (S1-hTERT) and vice versa. The data indicated that signal sending cells are more important in the medium-mediated bystander effect than recipients. Finally, we followed long term effects in immortalized radiation sensitive (S1-hTERT) and normal (F11-hTERT) fibroblasts up to 63 days after IR. In F11-hTERT cells CD level was increased until 35 days after IR then reduced back to control level by day 49. In S1-hTERT cells the increased CD level was also normalized by day 42, however a second wave of increased CD incidence appeared by day 49 which was maintained up to day 63 after IR. This second CD wave might be the indication of radiation-induced instability in the mitochondrial genome of S1-hTERT cells. The data demonstrated that measuring CD in mtDNA by qRT-PCR is a reliable and sensitive biomarker to estimate radiation-induced direct and non-targeted effects. Copyright © 2011 Elsevier B.V. All rights reserved.

Factors influencing Chinese university students' willingness to performing bystander cardiopulmonary resuscitation.

PubMed

Lu, Cui; Jin, Ying-Hui; Shi, Xiao-Tong; Ma, Wen-Jing; Wang, Yun-Yun; Wang, Wei; Zhang, Yao

2017-05-01

Low rates of bystander-initiated CPR are a major obstacle to improved survival rates, and the aim of this study is to elucidate the factors associated with university students' attitudes toward performing bystander CPR. Questionnaires were distributed to 18 universities across three metropolises in China. One question asking for respondents' attitudes toward performing bystander CPR was set as the dependent variable, and the logistic regression models were used to extract independent factors for respondents' attitudes toward performing bystander CPR. 2934 questionnaires were completed, with a response rate of 81.5%. Results suggested that predictors of willingness to perform bystander CPR were: previous experience of performing bystander CPR, higher self-perceived ability to perform bystander CPR properly after instruction, medicine and law discipline, male gender, not being the single child of their parents, higher participation in university societies, being used to taking decisive action immediately, less self-perceived life stress and higher self-perceived knowledge level of CPR. Persons having previous experience of performing bystander CPR and those who thought they would have the ability to perform bystander CPR properly are predominantly associated with willingness to perform bystander CPR. Psychological and cultural factors need further study. Copyright © 2016 Elsevier Ltd. All rights reserved.

Stochastic models of the bystander effect and of transmissible genomic instability: implications for mechanisms and low dose risks

NASA Astrophysics Data System (ADS)

Little, M. P.

Bystander effects following exposure to α -particles have been observed in C3H 10T cells and in other experimental systems, and imply that linearly extrapolating low dose risks from high-dose data might materially underestimate risk. In many experimental systems there is evidence of saturation of dose response that would be expected from the bystander effect. The ratio of lung cancer risk among persons exposed to low and high doses of radon daughters is 2.4 -- 4.0, with an upper 95% confidence limit of about 14. Assuming the bystander effect observed in the C3H 10T data applies to human lung cells in vivo, the epidemiological data imply that the number of neighbouring cells that can contribute to the bystander effect is between 0 and 1, with an upper 95% confidence limit of about 7. As a consequence, the bystander effect observed in the C3H 10T system probably does not play a large part in the process of radon-induced lung carcinogenesis in humans. Other experimental data relating to the bystander effect after α -particle exposure are surveyed; some of these data are more compatible with the epidemiological data. Three models of genomic instability recently developed by Little and Wright (Math. Biosci. 2003;183:111-34), with two, three and five stages, are compared with the four-stage model proposed by Luebeck and Moolgavkar (PNAS 2002;99:15095-100) and the two-stage model of Nowak et al. (PNAS 2002;99:16226-31). All models are fitted to SEER colon cancer data. Although the five-stage model of Little and Wright (2003) provides the best fit, it is not much superior to that of the model of Nowak et al. (2002) or the two- and three-stage models of Little and Wright (2003). The fit of the model of Luebeck and Moolgavkar (2002) is somewhat worse than these three, particularly for females under the age of 40. Comparison of the predictions of the two-stage models of Little and Wright (2003) and Nowak (2002) with patterns of excess risk in the Japanese atomic bomb survivor colon cancer incidence data indicate that radiation might act on cell proliferation rates in the model, and at least for the model of Little and Wright also on one of the parameters governing progression to genomic destabilization.

Is there a common mechanism underlying genomic instability, bystander effects and other nontargeted effects of exposure to ionizing radiation?

NASA Technical Reports Server (NTRS)

Morgan, William F.

2003-01-01

A number of nontargeted and delayed effects associated with radiation exposure have now been described. These include radiation-induced genomic instability, death-inducing and bystander effects, clastogenic factors and transgenerational effects. It is unlikely that these nontargeted effects are directly induced by cellular irradiation. Instead, it is proposed that some as yet to be identified secreted factor can be produced by irradiated cells that can stimulate effects in nonirradiated cells (death-inducing and bystander effects, clastogenic factors) and perpetuate genomic instability in the clonally expanded progeny of an irradiated cell. The proposed factor must be soluble and capable of being transported between cells by cell-to-cell gap junction communication channels. Furthermore, it must have the potential to stimulate cellular cytokines and/or reactive oxygen species. While it is difficult to imagine a role for such a secreted factor in contributing to transgenerational effects, the other nontargeted effects of radiation may all share a common mechanism.

Building upon Bystander Intervention: A Multi-Component Prevention Programming Approach for University Sorority Members

ERIC Educational Resources Information Center

Steward, Jennifer M.

2017-01-01

Sexual violence on college campuses is a pervasive problem with the potential for extensive physical and psychological health consequences. Institutions have begun implementing prevention programs; however, more research is needed to understand whether these programs are effective. Bystander intervention programs have increased in popularity…

Bystanders Are the Key to Stopping Bullying

ERIC Educational Resources Information Center

Padgett, Sharon; Notar, Charles E.

2013-01-01

Bullying is the dominance over another. Bullying occurs when there is an audience. Peer bystanders provide an audience 85% of instances of bullying. If you remove the audience bullying should stop. The article is a review of literature (2002-2013) on the role of bystanders; importance of bystanders; why bystanders behave as they do; resources to…

An Application of the Reasoned Action Approach to Bystander Intervention for Sexual Assault.

PubMed

Lukacena, Kaylee M; Reynolds-Tylus, Tobias; Quick, Brian L

2017-10-25

The high prevalence of sexual assault in US college campuses has led to a widespread implementation of bystander intervention programs aimed at preventing sexual assault. The current study examines predictors of college students' intentions to engage in bystander intervention through the theoretical lens of the reasoned action approach. An online survey with college students (N = 186) was conducted at a large Midwestern university. Our results indicated experiential attitudes, instrumental attitudes, descriptive norms, autonomy, and capacity, each positively associated with participants' intentions to intervene to stop a sexual assault. Against expectations, injunctive norms were unrelated to bystander intervention intentions. Finally, in addition to these main effects, an experiential attitude by autonomy interaction was also observed. The results are discussed with a focus on the theoretical and practical implications of our findings.

Mechanism of bystander-blaming: defensive attribution, counterfactual thinking, and gender.

PubMed

Levy, Inna; Ben-David, Sarah

2015-01-01

Contemporary victimology recognizes that an understanding of the mechanism of blaming requires a comprehensive approach that includes the victim, the offender, and the bystander. However, most of the existing research on blaming focuses on the victim and the offender, ignoring the issue of bystander-blaming. This study highlights the bystander and investigates bystander-blaming by exploring some theoretical explanations, including counterfactual thinking, defensive attribution, and gender differences. The study included 363 young male and female participants, who read vignettes describing the behavior of the victim and the bystander in a rape scenario and answered questions regarding bystander-blaming. The results show that both counterfactual thinking and defensive attribution play a role in bystander-blaming. This article addresses the theoretical and practical implications of these findings. © The Author(s) 2013.

Do Ravens Show Consolation? Responses to Distressed Others

PubMed Central

Fraser, Orlaith N.; Bugnyar, Thomas

2010-01-01

Background Bystander affiliation (post-conflict affiliation from an uninvolved bystander to the conflict victim) may represent an expression of empathy in which the bystander consoles the victim to alleviate the victim's distress (“consolation”). However, alternative hypotheses for the function of bystander affiliation also exist. Determining whether ravens spontaneously offer consolation to distressed partners may not only help us to understand how animals deal with the costs of aggressive conflict, but may also play an important role in the empathy debate. Methodology/Principal findings This study investigates the post-conflict behavior of ravens, applying the predictive framework for the function of bystander affiliation for the first time in a non-ape species. We found weak evidence for reconciliation (post-conflict affiliation between former opponents), but strong evidence for both bystander affiliation and solicited bystander affiliation (post-conflict affiliation from the victim to a bystander). Bystanders involved in both interactions were likely to share a valuable relationship with the victim. Bystander affiliation offered to the victim was more likely to occur after intense conflicts. Renewed aggression was less likely to occur after the victim solicited affiliation from a bystander. Conclusions/Significance Our findings suggest that in ravens, bystanders may console victims with whom they share a valuable relationship, thus alleviating the victims' post-conflict distress. Conversely victims may affiliate with bystanders after a conflict in order to reduce the likelihood of renewed aggression. These results stress the importance of relationship quality in determining the occurrence and function of post-conflict interactions, and show that ravens may be sensitive to the emotions of others. PMID:20485685

3D-modelling of radon-induced cellular radiobiological effects in bronchial airway bifurcations: direct versus bystander effects.

PubMed

Szőke, István; Farkas, Arpád; Balásházy, Imre; Hofmann, Werner; Madas, Balázs G; Szőke, Réka

2012-06-01

The primary objective of this paper was to investigate the distribution of radiation doses and the related biological responses in cells of a central airway bifurcation of the human lung of a hypothetical worker of the New Mexico uranium mines during approximately 12 hours of exposure to short-lived radon progenies. State-of-the-art computational modelling techniques were applied to simulate the relevant biophysical and biological processes in a central human airway bifurcation. The non-uniform deposition pattern of inhaled radon daughters caused a non-uniform distribution of energy deposition among cells, and of related cell inactivation and cell transformation probabilities. When damage propagation via bystander signalling was assessed, it produced more cell killing and cell transformation events than did direct effects. If bystander signalling was considered, variations of the average probabilities of cell killing and cell transformation were supra-linear over time. Our results are very sensitive to the radiobiological parameters, derived from in vitro experiments (e.g., range of bystander signalling), applied in this work and suggest that these parameters may not be directly applicable to realistic three-dimensional (3D) epithelium models.

'We didn't know anything, it was a mess!' Emergent structures and the effectiveness of a rescue operation multi-team system.

PubMed

Fleştea, Alina Maria; Fodor, Oana Cătălina; Curşeu, Petru Lucian; Miclea, Mircea

2017-01-01

Multi-team systems (MTS) are used to tackle unpredictable events and to respond effectively to fast-changing environmental contingencies. Their effectiveness is influenced by within as well as between team processes (i.e. communication, coordination) and emergent phenomena (i.e. situational awareness). The present case study explores the way in which the emergent structures and the involvement of bystanders intertwine with the dynamics of processes and emergent states both within and between the component teams. Our findings show that inefficient transition process and the ambiguous leadership generated poor coordination and hindered the development of emergent phenomena within the whole system. Emergent structures and bystanders substituted leadership functions and provided a pool of critical resources for the MTS. Their involvement fostered the emergence of situational awareness and facilitated contingency planning processes. However, bystander involvement impaired the emergence of cross-understandings and interfered with coordination processes between the component teams. Practitioner Summary: Based on a real emergency situation, the present research provides important theoretical and practical insights about the role of bystander involvement in the dynamics of multi-team systems composed to tackle complex tasks and respond to fast changing and unpredictable environmental contingencies.

Human Lung Cancer Risks from Radon – Part II – Influence from Combined Adaptive Response and Bystander Effects – A Microdose Analysis

PubMed Central

Leonard, Bobby E.; Thompson, Richard E.; Beecher, Georgia C.

2010-01-01

In the prior Part I, the potential influence of the low level alpha radiation induced bystander effect (BE) on human lung cancer risks was examined. Recent analysis of adaptive response (AR) research results with a Microdose Model has shown that single low LET radiation induced charged particles traversals through the cell nucleus activates AR. We have here conducted an analysis based on what is presently known about adaptive response and the bystander effect (BE) and what new research is needed that can assist in the further evaluation human cancer risks from radon. We find that, at the UNSCEAR (2000) worldwide average human exposures from natural background and man-made radiations, the human lung receives about a 25% adaptive response protection against the radon alpha bystander damage. At the UNSCEAR (2000) minimum range of background exposure levels, the lung receives minimal AR protection but at higher background levels, in the high UNSCEAR (2000) range, the lung receives essentially 100% protection from both the radon alpha damage and also the endogenic, spontaneously occurring, potentially carcinogenic, lung cellular damage. PMID:22461760

Radiation-induced bystander effect and adaptive response in mammalian cells

NASA Technical Reports Server (NTRS)

Zhou, H.; Randers-Pehrson, G.; Waldren, C. A.; Hei, T. K.

2004-01-01

Two conflicting phenomena, bystander effect and adaptive response, are important in determining the biological responses at low doses of radiation and have the potential to impact the shape of the dose-response relationship. Using the Columbia University charged-particle microbeam and the highly sensitive AL cell mutagenic assay, we show here that non-irradiated cells acquire mutagenesis through direct contact with cells whose nuclei have been traversed with a single alpha particle each. Pretreatment of cells with a low dose of X-rays four hours before alpha particle irradiation significantly decreased this bystander mutagenic response. Results from the present study address some of the fundamental issues regarding both the actual target and radiation dose effect and can contribute to our current understanding in radiation risk assessment. c2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

Impact of neighbourhood socio-economic status on bystander cardiopulmonary resuscitation in Paris.

PubMed

Dahan, Benjamin; Jabre, Patricia; Karam, Nicole; Misslin, Renaud; Tafflet, Muriel; Bougouin, Wulfran; Jost, Daniel; Beganton, Frankie; Marijon, Eloi; Jouven, Xavier

2017-01-01

No European data currently describe the relation between neighbourhood socio-economic status (SES) and rates of out-of-hospital cardiac arrest (OHCA) bystander cardiopulmonary resuscitation (CPR). This study aims to analyse this effect with a robust deprivation index. Data about all OHCA in Paris were collected prospectively between 2000 and 2010. A geographical neighbourhood unit was assigned to each case. Median household income, and rates of blue-collar workers, unemployment, and adults without high school diplomas were selected as SES characteristics and used to classify neighbourhoods as low SES or higher SES. We analysed the relationship between neighbourhood SES characteristics and the probability of receiving bystander CPR. Of the 4009 OHCA with mappable addresses recorded, 777 (19.4%) received bystander CPR. Compared to OHCA who did not receive bystander CPR, those receiving CPR were significantly more likely to have occurred in public locations, have had a witness to their OHCA, and not to have collapsed in a low SES neighbourhood, or in a neighbourhood with a median household income in the lowest quartile and with rates of no high school diplomas and blue-collar workers in the highest quartile. In the multilevel analyses, bystander CPR provision was significantly less frequent in low than in higher SES neighbourhoods (OR 0.85; 95% confidence interval [CI] 0.72-0.99). In the city of Paris, OHCA victims were less likely to receive bystander CPR in low SES neighbourhoods. These first European data are consistent with observations in North America and Asia. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Regions With Low Rates of Bystander Cardiopulmonary Resuscitation (CPR) Have Lower Rates of CPR Training in Victoria, Australia.

PubMed

Bray, Janet E; Straney, Lahn; Smith, Karen; Cartledge, Susie; Case, Rosalind; Bernard, Stephen; Finn, Judith

2017-06-05

Bystander cardiopulmonary resuscitation (CPR) more than doubles the chance of surviving an out-of-hospital cardiac arrest. Recent data have shown considerable regional variation in bystander CPR rates across the Australian state of Victoria. This study aims to determine whether there is associated regional variation in rates of CPR training and willingness to perform CPR in these communities. We categorized each Victorian postcode as either a low or high bystander CPR region using data on adult, bystander-witnessed, out-of-hospital cardiac arrests of presumed cardiac etiology (n=7175) from the Victorian Ambulance Cardiac Arrest Registry. We then surveyed adult Victorians (n=404) and compared CPR training data of the respondents from low and high bystander CPR regions. Of the 404 adults surveyed, 223 (55%) resided in regions with low bystander CPR. Compared with respondents from high bystander CPR regions, respondents residing in regions with low bystander CPR had lower rates of CPR training (62% versus 75%, P =0.009) and lower self-ratings for their overall knowledge of CPR (76% versus 84%, P =0.04). There were no differences between the regions in their reasons for not having undergone CPR training or in their willingness to perform CPR. Rates of survival for bystander-witnessed, out-of-hospital cardiac arrests were significantly lower in low bystander CPR regions (15.7% versus 17.0%, P <0.001). This study found lower rates of CPR training and lower survival in regions with lower rates of bystander CPR in Victoria, Australia. Targeting these regions with CPR training programs may improve bystander CPR rates and out-of-hospital cardiac arrest outcomes. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Bullying victimization and the social and emotional maladjustment of bystanders: A propensity score analysis.

PubMed

Werth, Jilynn M; Nickerson, Amanda B; Aloe, Ariel M; Swearer, Susan M

2015-08-01

This study investigated how bystanders, who have and have not been bullied, perceive their social and emotional maladjustment depending on the form of bullying (physical or verbal) they witness. Using propensity score matching, equivalent groups of 270 victimized and 270 non-victimized bystander groups were created based on middle school students' responses on the Bully Survey-Student Version (BYS-S; Swearer, 2001). Victimized bystanders experienced higher social maladjustment than non-victimized bystanders. Path analysis results suggest that social and emotional maladjustment as a bystander is related not only to social-emotional maladjustment as victim, but to gender and the form of bullying witnessed. The way in which bystanders are influenced by their personal victimization may be a critical factor in predicting, understanding, and increasing active bystander intervention. Copyright © 2015 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

Rethinking the bystander role in school violence prevention.

PubMed

Stueve, Ann; Dash, Kimberly; O'Donnell, Lydia; Tehranifar, Parisa; Wilson-Simmons, Renée; Slaby, Ronald G; Link, Bruce G

2006-01-01

Public concerns about school shootings and safety draw attention to the role bystanders can play in preventing school violence. Although school violence prevention plans are often required, there is little guidance about whether these should address the roles of bystanders and what actions bystanders should take in different circumstances, from more common instances of bullying and fighting to rare, but potentially lethal, threats and use of weapons. Literature pertaining to bystanders is reviewed and applied to the school setting. The definition of bystander is expanded, including parents, teachers, and other school staff as well as youths and those who have information about potential violence as well as those who witness its occurrence. Barriers preventing bystanders from taking positive actions are discussed. The authors call on health promotion researchers and practitioners to work with school communities to identify norms, attitudes, and outcome expectancies that shape bystander behaviors to inform prevention efforts.

Chromosome damage evolution after low and high LET irradiation

NASA Astrophysics Data System (ADS)

Andreev, Sergey; Eidelman, Yuri

Ionizing radiation induces DNA and chromatin lesions which are converted to chromosome lesions detected in the first post-irradiation mitosis by classic cytogenetic techniques as chromosomal aberrations (CAs). These techniques allow to monitor also delayed aberrations observed after many cell generations post-irradiation - the manifestation of chromosomal instability phenotype (CIN). The problem discussed is how to predict time evolution from initial to delayed DNA/chromosome damage. To address this question, in the present work a mechanistic model of CIN is elaborated which integrates pathways of (*) DNA damage induction and its conversion to chromosome lesions (aberrations), (**) lesion transmission and generation through cell cycles. Delayed aberrations in subsequent cycles are formed in the model owing to two pathways, DNA damage generation de novo as well as CA transmission from previous cycles. DNA damage generation rate is assumed to consist of bystander and non-bystander components. Bystander signals impact all cells roughly equally, whereas non-bystander DSB generation rate differs for the descendants of unirradiated and irradiated cells. Monte Carlo simulation of processes underlying CIN allows to predict the time evolution of initial radiation-induced damage - kinetics curve for delayed unstable aberrations (dicentrics) together with dose response and RBE as a function of time after high vs low LET irradiation. The experimental data for radiation-induced CIN in TK6 lymphoblastoid cells and human lymphocytes irradiated with low (gamma) and high (Fe, C) LET radiation are analyzed on the basis of the proposed model. One of the conclusions is that without bystander signaling, just taking into account the initial DNA damage and non-bystander DSB generation, it is impossible to describe the available experimental data for high-LET-induced CIN. The exact contribution of bystander effects for high vs low LET remains unknown, but the relative contribution may be assessed at large times after initial acute irradiation. RBE for delayed aberrations depends on LET, time and cell line, which probably reflects a genetic background for bystander component. The proposed modeling approach creates a basis for integration of complex network of bystander/inflammatory signaling in systems-level platform for quantification of radiation induced CIN.

Mechanisms underlying cellular responses of cells from haemopoietic tissue to low dose/low LET radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Munira A Kadhim

2010-03-05

To accurately define the risks associated with human exposure to relevant environmental doses of low LET ionizing radiation, it is necessary to completely understand the biological effects at very low doses (i.e., less than 0.1 Gy), including the lowest possible dose, that of a single electron track traversal. At such low doses, a range of studies have shown responses in biological systems which are not related to the direct interaction of radiation tracks with DNA. The role of these “non-targeted” responses in critical tissues is poorly understood and little is known regarding the underlying mechanisms. Although critical for dosimetry andmore » risk assessment, the role of individual genetic susceptibility in radiation risk is not satisfactorily defined at present. The aim of the proposed grant is to critically evaluate radiation-induced genomic instability and bystander responses in key stem cell populations from haemopoietic tissue. Using stem cells from two mouse strains (CBA/H and C57BL/6J) known to differ in their susceptibility to radiation effects, we plan to carefully dissect the role of genetic predisposition on two non-targeted radiation responses in these models; the bystander effect and genomic instability, which we believe are closely related. We will specifically focus on the effects of low doses of low LET radiation, down to doses approaching a single electron traversal. Using conventional X-ray and γ-ray sources, novel dish separation and targeted irradiation approaches, we will be able to assess the role of genetic variation under various bystander conditions at doses down to a few electron tracks. Irradiations will be carried out using facilities in routine operation for bystander targeted studies. Mechanistic studies of instability and the bystander response in different cell lineages will focus initially on the role of cytokines which have been shown to be involved in bystander signaling and the initiation of instability. These studies also aim to uncover protein mediators of the bystander responses using advanced proteomic screening of factors released from irradiated, bystander and unstable cells. Integral to these studies will be an assessment of the role of genetic susceptibility in these responses, using CBA/H and C57BL/6J mice. The relevance of in vivo interactions between stem cells and the stem cell niche will be explored in the future by re-implantation techniques of previously irradiated cells. The above studies will provide fundamental mechanistic information relating genetic predisposition to important low dose phenomena, and will aid in the development of Department of Energy policy, as well as radiation risk policy for the public and the workplace. We believe the proposed studies accurately reflect the goals of the DOE low dose program.« less

“Protective Bystander Effects Simulated with the State-Vector Model”—HeLa x Skin Exposure to 137Cs Not Protective Bystander Response But Mammogram and Diagnostic X-Rays Are

PubMed Central

Leonard, Bobby E.

2008-01-01

The recent Dose Response journal article “Protective Bystander Effects Simulated with the State-Vector Model” (Schollnberger and Eckl 2007) identified the suppressive (below natural occurring, zero primer dose, spontaneous level) dose response for HeLa x skin exposure to 137Cs gamma rays (Redpath et al 2001) as a protective Bystander Effect (BE) behavior. I had previously analyzed the Redpath et al (2001) data with a Microdose Model and conclusively showed that the suppressive response was from Adaptive Response (AR) radio-protection (Leonard 2005, 2007a). The significance of my microdose analysis has been that low LET radiation induced single (i.e. only one) charged particle traversals through a cell can initiate a Poisson distributed activation of AR radio-protection. The purpose of this correspondence is to clarify the distinctions relative to the BE and the AR behaviors for the Redpath groups 137Cs data, show conversely however that the Redpath group data for mammography (Ko et al 2004) and diagnostic (Redpath et al 2003) X-rays do conclusively reflect protective bystander behavior and also herein emphasize the need for radio-biologist to apply microdosimetry in planning and analyzing their experiments for BE and AR. Whether we are adamantly pro-LNT, adamantly anti-LNT or, like most of us, just simple scientists searching for the truth in radio-biology, it is important that we accurately identify our results, especially when related to the LNT hypothesis controversy. PMID:18846260

Variations in Involvement: Motivating Bystanders to Care for Senior Citizens.

PubMed

Keller, Sarah N; Wilkinson, Tim

2017-01-01

The purpose of this study was to determine the impact of a senior service advertising campaign designed to increase volunteerism and financial donations among bystanders. A cross-sectional mail survey was administered to 2,500 adults; 384 usable responses were obtained. Survey responses were analyzed by level of exposure and involvement in senior care. High involvement individuals viewed the ads more favorably and exhibited stronger senior caretaking intentions. Low-involvement consumers were less likely to see their own potential contributions to senior care services as effective. It is argued that nonparticipants in prosocial helping may fail to notice the need (low awareness), fail to view the cause as urgent (low perceived susceptibility), or have low prior experience with the issue. A typology of involvement could be developed that can be used for audience segmentation in marketing health behaviors to bystanders. With limited theoretical and practical guidance on how to motivate bystanders to engage in prosocial behaviors, health communicators and marketers are challenged to tap into the vital resource that bystanders potentially could provide. The research reviewed and presented here indicates hope for engaging the public to become active players in making the nation a safer and healthier place.

Friends, strangers, and bystanders: Informal practices of sexual assault intervention.

PubMed

Wamboldt, Alexander; Khan, Shamus R; Mellins, Claude Ann; Hirsch, Jennifer S

2018-05-07

Sexual assault is a part of many students' experiences in higher education. In U.S. universities, one in four women and one in ten men report being sexually assaulted before graduation. Bystander training programmes have been shown to modestly reduce campus sexual assault. Like all public health interventions, however, they have unintended social consequences; this research examines how undergraduate men on one campus understand bystander interventions and how those understandings shape their actual practices. We draw on ethnographic data collected between August 2015 and January 2017 at Columbia University and Barnard College. Our findings show that university training and an earnest desire to be responsible lead many men to intervene in possible sexual assaults. However, students' gendered methods target more socially vulnerable and socially distant men while protecting popular men and those to whom they are socially connected. Students' actual bystander practices thus reproduce social hierarchies in which low prestige may or may not be connected to actual risks of sexual assault. These results suggest that understanding intragroup dynamics and social hierarchies is essential to assault prevention in universities and that students' actions as bystanders may be effective at preventing assaults in some circumstances but may lead to new risks of sexual assault.

It's Your Place: Development and Evaluation of an Evidence-Based Bystander Intervention Campaign.

PubMed

Sundstrom, Beth; Ferrara, Merissa; DeMaria, Andrea L; Gabel, Colby; Booth, Kathleen; Cabot, Jeri

2017-06-28

Preventing sexual assault on college campuses is a national priority. Bystander intervention offers a promising approach to change social norms and prevent sexual misconduct. This study presents the implementation and evaluation of a theory-based campaign to promote active bystander intervention. The theory of planned behavior (TPB) served as a conceptual framework throughout campaign development and evaluation. Formative research published elsewhere was used to develop campaign strategies, communication channels, and messages, including "It is your place to prevent sexual assault: You're not ruining a good time." The It's Your Place multi-media campaign fosters a culture of bystander intervention through peer-to-peer facilitation and training, as well as traditional and new media platforms. A cross-sectional post-test only web-based survey was designed to evaluate the campaign and test the TPB's ability to accurately predict intention to intervene. Survey data were collected from 1,505 currently enrolled students. The TPB model predicted intention to intervene. There was a significant effect of campaign exposure on attitude, subjective norms, and perceived behavioral intention. This theory-based communication campaign offers implications for promoting active bystander intervention and reducing sexual assault.

A Bystander Bullying Psychoeducation Program with Middle School Students: A Preliminary Report

ERIC Educational Resources Information Center

Midgett, Aida; Doumas, Diana; Sears, Dara; Lundquist, Amanda; Hausheer, Robin

2015-01-01

This study evaluated the effectiveness of a brief, stand-alone bystander bullying psychoeducation program for middle school students. The purpose of the program was to train students to take action as peer advocates. Pre- and post-tests indicated that after completing the 90-minute psychoeducation program, students reported an increase in their…

Total and Marginal Cost Analysis for a High School Based Bystander Intervention

ERIC Educational Resources Information Center

Bush, Joshua L.; Bush, Heather M.; Coker, Ann L.; Brancato, Candace J.; Clear, Emily R.; Recktenwald, Eileen A.

2018-01-01

Costs of providing the Green Dot bystander-based intervention, shown to be effective in the reduction of sexual violence among Kentucky high school students, were estimated based on data from a large cluster-randomized clinical trial. Rape Crisis Center Educators were trained to provide Green Dot curriculum to students. Implementing Green Dot in…

Personal Responsibility and Behavioral Disengagement in Innocent Bystanders during Classroom Management Events: The Moderating Effect of Teacher Aggressive Tendencies

ERIC Educational Resources Information Center

Montuoro, Paul; Lewis, Ramon

2018-01-01

Recent studies have shown that student behavioral engagement is malleable. For example, these studies have reported that students who feel emotionally supported by their teachers experience higher levels of behavioral engagement. The authors contributed to this research by investigating behavioral disengagement among innocent bystanders during…

A Randomized Controlled Study Evaluating a Brief, Bystander Bullying Intervention with Junior High School Students

ERIC Educational Resources Information Center

Midgett, Aida; Doumas, Diana; Trull, Rhiannon; Johnston, April D.

2017-01-01

A randomized controlled study evaluated a brief, bystander bullying intervention for junior high school students. Students in both groups reported an increase in knowledge and confidence to act as defenders and to utilize strategies to intervene on behalf of victims of bullying. Findings suggest possible carry-over effects from the intervention…

Chromosomal mutagenesis in human somatic cells: 30-year cytogenetic monitoring after Chornobyl accident.

PubMed

Pilinska, M A; Shemetun, G M; Shemetun, O V; Dybsky, S S; Dybska, O B; Talan, O O; Pedan, L R; Kurinnyi, D А

2016-12-01

In the lecture we have generalized and analyzed the data of cytogenetic laboratory of National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine on 30-year selective cytogenetic monitoring among the priority contingents of different ages exposed to radiation after Chornobyl accident in Ukraine. It is highlighted that not only targeted but also untargeted radiation-induced cytogenetic effects should be explored, especially in delayed terms following radiation exposure. The new methodical approaches for studying "bystander effect", individual radiosensitivity, and various forms of radiation-induced chromosomal instability (delayed, hidden, transmissible) have been proposed. These approaches proved to be advantageous for analyzing cytogenetic patterns of induction and persistence of chromosomal instability in human somatic cells because of "bystander effect" and "bystander type effect". The phenomenon of positive "reverse" bystander effect has been found. The possibility of modifying the inherited individual human susceptibility to mutagenic exposure by ionizing radiation has been estimated. Finally, the association between hypersensitivity to radiation exposure and realization of oncopathology in exposed individuals has been revealed. The increased intensity of human somatic chromosomal mutagenesis was confirmed not only in the nearest but in the delayed terms following Chornobyl accident as a result of radiation-induced both targeted and untargeted cytogenetic effects. Such effects can be considered as risk factors for malignant transformation of cells, hereditary diseases, birth defects, and multifactorial somatic pathology. This article is a part of a Special Issue entitled "The Chornobyl Nuclear Accident: Thirty Years After".

Nitric oxide-mediated bystander signal transduction induced by heavy-ion microbeam irradiation

NASA Astrophysics Data System (ADS)

Tomita, Masanori; Matsumoto, Hideki; Funayama, Tomoo; Yokota, Yuichiro; Otsuka, Kensuke; Maeda, Munetoshi; Kobayashi, Yasuhiko

2015-07-01

In general, a radiation-induced bystander response is known to be a cellular response induced in non-irradiated cells after receiving bystander signaling factors released from directly irradiated cells within a cell population. Bystander responses induced by high-linear energy transfer (LET) heavy ions at low fluence are an important health problem for astronauts in space. Bystander responses are mediated via physical cell-cell contact, such as gap-junction intercellular communication (GJIC) and/or diffusive factors released into the medium in cell culture conditions. Nitric oxide (NO) is a well-known major initiator/mediator of intercellular signaling within culture medium during bystander responses. In this study, we investigated the NO-mediated bystander signal transduction induced by high-LET argon (Ar)-ion microbeam irradiation of normal human fibroblasts. Foci formation by DNA double-strand break repair proteins was induced in non-irradiated cells, which were co-cultured with those irradiated by high-LET Ar-ion microbeams in the same culture plate. Foci formation was suppressed significantly by pretreatment with an NO scavenger. Furthermore, NO-mediated reproductive cell death was also induced in bystander cells. Phosphorylation of NF-κB and Akt were induced during NO-mediated bystander signaling in the irradiated and bystander cells. However, the activation of these proteins depended on the incubation time after irradiation. The accumulation of cyclooxygenase-2 (COX-2), a downstream target of NO and NF-κB, was observed in the bystander cells 6 h after irradiation but not in the directly irradiated cells. Our findings suggest that Akt- and NF-κB-dependent signaling pathways involving COX-2 play important roles in NO-mediated high-LET heavy-ion-induced bystander responses. In addition, COX-2 may be used as a molecular marker of high-LET heavy-ion-induced bystander cells to distinguish them from directly irradiated cells, although this may depend on the time after irradiation.

Dioscin augments HSV-tk-mediated suicide gene therapy for melanoma by promoting connexin-based intercellular communication

PubMed Central

Li, Bin; Wu, Yingya; Liu, Xijuan; Tan, Yuhui; Du, Biaoyan

2017-01-01

Suicide gene therapy is a promising strategy against melanoma. However, the low efficiency of the gene transfer technique can limit its application. Our preliminary data showed that dioscin, a glucoside saponin, could upregulate the expression of connexins Cx26 and Cx43, major components of gap junctions, in melanoma cells. We hypothesized that dioscin may increase the bystander effect of herpes simplex virus thymidine kinase/ganciclovir (HSV-tk/GCV) through increasing the formation of gap junctions. Further analysis showed that dioscin indeed could increase the gap junctional intercellular communication in B16 melanoma cells, resulting in more efficient GCV-induced bystander killing in B16tk cells. By contrast, overexpression of dominant negative Cx43 impaired the cell-cell communication of B16 cells and subsequently weakened the bystander effect of HSV-tk/GCV gene therapy. In vivo, combination treatment with dioscin and GCV of tumor-bearing mice with 30% positive B16tk cells and 70% wild-type B16 cells caused a significant reduction in tumor volume and weight compared to treatment with GCV or dioscin alone. Taken together, these results demonstrated that dioscin could augment the bystander effect of the HSV-tk/GCV system through increasing connexin-mediated gap junction coupling. PMID:27903977

Theoretical models and simulation codes to investigate bystander effects and cellular communication at low doses

NASA Astrophysics Data System (ADS)

Ballarini, F.; Alloni, D.; Facoetti, A.; Mairani, A.; Nano, R.; Ottolenghi, A.

Astronauts in space are continuously exposed to low doses of ionizing radiation from Galactic Cosmic Rays During the last ten years the effects of low radiation doses have been widely re-discussed following a large number of observations on the so-called non targeted effects in particular bystander effects The latter consist of induction of cytogenetic damage in cells not directly traversed by radiation most likely as a response to molecular messengers released by directly irradiated cells Bystander effects which are observed both for lethal endpoints e g clonogenic inactivation and apoptosis and for non-lethal ones e g mutations and neoplastic transformation tend to show non-linear dose responses This might have significant consequences in terms of low-dose risk which is generally calculated on the basis of the Linear No Threshold hypothesis Although the mechanisms underlying bystander effects are still largely unknown it is now clear that two types of cellular communication i e via gap junctions and or release of molecular messengers into the extracellular environment play a fundamental role Theoretical models and simulation codes can be of help in elucidating such mechanisms In the present paper we will review different available modelling approaches including one that is being developed at the University of Pavia The focus will be on the different assumptions adopted by the various authors and on the implications of such assumptions in terms of non-targeted radiobiological damage and more generally low-dose

Melatonin Ameliorates The Production of COX-2, iNOS, and The Formation of 8-OHdG in Non-Targeted Lung Tissue after Pelvic Irradiation.

PubMed

Fardid, Reza; Salajegheh, Ashkan; Mosleh-Shirazi, Mohammad Amin; Sharifzadeh, Sedigheh; Okhovat, Mohammad Ali; Najafi, Masoud; Rezaeyan, Abolhasan; Abaszadeh, Akbar

2017-01-01

In this study, we evaluated the bystander effect of radiation on the regulation of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and 8-hydroxydeoxyguanosine (8-OHdG) in lung tissues of Sprague-Dawley rats with and without pre-administration of melatonin. A 2×2 cm 2 area of the pelvis of male Sprague-Dawley rats with and without pre-administration of melatonin (100 mg/kg) by oral and intraperitoneal injection was irradiated with a 3 Gy dose of 1.25 MeV γ-rays. Alterations in the levels of COX-2, iNOS, and 8-OHdG in the out-of-field lung areas of the animals were detected by enzyme immunoassay. The bystander effect significantly increased COX-2, iNOS, and 8-OHdG levels in non-targeted lung tissues (P<0.05). Melatonin ameliorated the bystander effect of radiation and significantly reduced the level of all examined biomarkers (P<0.05). The results indicated that the ameliorating effect of a pre-intraperitoneal (IP) injection of melatonin was noticeably greater compared to oral pre-administration. Our findings revealed that the bystander effect of radiation could induce oxidative DNA damage and increase the levels of imperative COX-2 and iNOS in non-targeted lung tissues. Interestingly, melatonin could modulate the indirect destructive effect of radiation and reduce DNA damage in non-targeted cells.

LGBT Discrimination on Campus and Heterosexual Bystanders: Understanding Intentions to Intervene

ERIC Educational Resources Information Center

Dessel, Adrienne B.; Goodman, Kevin D.; Woodford, Michael R.

2017-01-01

Discrimination targeting lesbian, gay, bisexual, and transgender (LGBT) students on college campuses occurs. Bystander intervention is important in supporting targeted students and improving campus climate for LGBT students. Peer-familiarity context (i.e., who the bystander knows in the situation) can play a role in bystander intervention, but…

Standing Up for the Victim, Siding with the Bully or Standing By? Bystander Responses in Bullying Situations

ERIC Educational Resources Information Center

Poyhonen, Virpi; Juvonen, Jaana; Salmivalli, Christina

2012-01-01

In this study we examined children's self-efficacy, outcome expectations, and outcome values in relation to bystander responses in bullying situations. We proposed that beyond the effect of self-efficacy, the decision to defend the victim of bullying vs. remain passive vs. reinforce the bully depends on outcomes children expect from defending, and…

Responding to Gendered Violence among College Students: The Impact of Participant Characteristics on Direct Bystander Intervention Behavior

ERIC Educational Resources Information Center

Franklin, Cortney A.; Brady, Patrick Q.; Jurek, Alicia L.

2017-01-01

Bystander intervention has been an effective strategy for crime prevention and has been successful in the context of campus sexual assault. Less is known about the extent to which individual-level factors correlate with intervention behavior in situations of intimate partner violence (IPV) and sexual harassment. The present study used a sample of…

School personnel social support and nonsupport for bystanders of bullying: Exploring student perspectives.

PubMed

Wood, Laura; Smith, Jennifer; Varjas, Kris; Meyers, Joel

2017-04-01

Defending behaviors by bystanders in bullying situations have been associated with decreases in the frequency and negative effects of bullying incidents. The current study utilized qualitative methodology to investigate the role of perceived school personnel support and nonsupport in students' decisions to display defending behaviors. Forty-six semi-structured interviews were conducted with upper-elementary (n=26) and middle school (n=20) students in the southeastern United States. Qualitative data were analyzed using constant comparison and a recursive inductive-deductive approach. The findings resulted in the conceptualization of a combined social support-nonsupport framework that provides details about the source, description, evaluation, and perceived effects of different types of support and nonsupport bystanders receive from school personnel. Unique contributions to the literature included expanding the sources of support and nonsupport to consider school personnel other than teachers, providing descriptions and evaluations of support and nonsupport specific to bystanders, and demonstrating an overlap between various types of support and nonsupport reiterating the need to consider both supports and nonsupports concurrently. Implications for research and practice are discussed. Copyright © 2016 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

Cyberbullying Among Adolescent Bystanders: Role of Affective Versus Cognitive Empathy in Increasing Prosocial Cyberbystander Behavior

PubMed Central

Barlińska, Julia; Szuster, Anna; Winiewski, Mikołaj

2018-01-01

The purpose of this study was to investigate if affective (vicarious sharing of emotions) and cognitive empathy (mental perspective taking) induction may stimulate adolescent online bystanders’ intervention in cyberbullying cases. The role of reporting the abuse is crucial because it is a form of active support to the victim, initiated by children, to stop the bullying. The effectiveness of empathy activation in decreasing negative cyberbystander reinforcing behavior has been proved in previous studies. The effects of affective and cognitive empathy activation on positive cyberbystander behavior, defined as reporting the bullying online, were explored in two follow-up studies N = 271 and N = 265. The influence of experiencing cyberbullying as perpetrator, victim, and as determined by gender on prosocial cyberbystander behavior was also controlled. The results indicate that only cognitive empathy activation increases the likelihood of intervening bystander behavior. Neither affective empathy induction, previous experience of cyberperpetration, cybervictimization, nor gender affected the engagement in prosocial bystander behavior. The conclusion of the research is that a program consequently activating more reflective cognitive empathy induction can contribute toward the establishment of healthier behavioral patterns among bystanders to cyberbullying, increasing the probability of their reporting the cyberbullying acts. PMID:29899715

Role of connexin43 and ATP in long-range bystander radiation damage and oncogenesis in vivo.

PubMed

Mancuso, M; Pasquali, E; Leonardi, S; Rebessi, S; Tanori, M; Giardullo, P; Borra, F; Pazzaglia, S; Naus, C C; Di Majo, V; Saran, A

2011-11-10

Ionizing radiation is a genotoxic agent and human carcinogen. Recent work has questioned long-held dogmas by showing that cancer-associated genetic alterations occur in cells and tissues not directly exposed to radiation, questioning the robustness of the current system of radiation risk assessment. In vitro, diverse mechanisms involving secreted soluble factors, gap junction intercellular communication (GJIC) and oxidative metabolism are proposed to mediate these indirect effects. In vivo, the mechanisms behind long-range 'bystander' responses remain largely unknown. Here, we investigate the role of GJIC in propagating radiation stress signals in vivo, and in mediating radiation-associated bystander tumorigenesis in mouse central nervous system using a mouse model in which intercellular communication is downregulated by targeted deletion of the connexin43 (Cx43) gene. We show that GJIC is critical for transmission of oncogenic radiation damage to the non-targeted cerebellum, and that a mechanism involving adenosine triphosphate release and upregulation of Cx43, the major GJIC constituent, regulates transduction of oncogenic damage to unirradiated tissues in vivo. Our data provide a novel hypothesis for transduction of distant bystander effects and suggest that the highly branched nervous system, similar to the vascular network, has an important role.

Rehearsing for real life: the impact of the InterACT Sexual Assault Prevention Program on self-reported likelihood of engaging in bystander interventions.

PubMed

Ahrens, Courtney E; Rich, Marc D; Ullman, Jodie B

2011-06-01

The interACT Sexual Assault Prevention Program is an interactive, skill-building performance based on the pedagogy of Augusto Boal's Theatre of the Oppressed. A longitudinal evaluation of this program compared pretest, posttest, and 3-month follow-up data from 509 university student participants. Results suggested that the interACT performance was successful in increasing participants' beliefs about the effectiveness of bystander interventions and the self-rated likelihood that participants would engage in bystander interventions in the future. Differences in both overall ratings and rates of change were noted. Implications of these results for research and practice are discussed.

Changing attitudes about being a bystander to violence: translating an in-person sexual violence prevention program to a new campus.

PubMed

Cares, Alison C; Banyard, Victoria L; Moynihan, Mary M; Williams, Linda M; Potter, Sharyn J; Stapleton, Jane G

2015-02-01

Bystander approaches to reducing sexual violence train community members in prosocial roles to interrupt situations with risk of sexual violence and be supportive community allies after an assault. This study employs a true experimental design to evaluate the effectiveness of Bringing in the Bystander™ through 1-year post-implementation with first-year students from two universities (one rural, primarily residential; one urban, heavily commuter). We found significant change in bystander attitudes for male and female student program participants compared with the control group on both campuses, although the pattern of change depended on the combination of gender and campus. © The Author(s) 2014.

Control, Norms, and Attitudes: Differences Between Students Who Do and Do Not Intervene as Bystanders to Sexual Assault.

PubMed

Hoxmeier, Jill C; Flay, Brian R; Acock, Alan C

2016-01-14

Sexual assault is a major concern on the U.S. college campus. Engaging students as pro-social bystanders has become more common as a potentially effective mechanism for reducing the incidence of sexual assault and mitigating the harm of assaults that have already occurred. Understanding the influences of pro-social bystander behavior is imperative to developing effective programs, and the use of an evidence-based theoretical framework can help identify the differences between students who intervene and those who do not when presented with the opportunity. A sample of 815 undergraduate university students completed the Sexual Assault Bystander Behavior Questionnaire, a survey based on the theory of planned behavior (TPB) that investigates students' perceived behavioral control to intervene, subjective norms that support intervening, attitudes toward intervening, and intent to intervene in the future. Two-tailed t tests revealed interveners reported significantly greater perceived behavioral control than non-interveners for eight of the 12 intervention behaviors, more supportive subjective norms than non-interveners for seven of the 12 intervention behaviors, more positive attitudes than non-interveners for only one of the 12 intervention behaviors, and greater intent to intervene in the future for six of the 12 intervention behaviors. Differences in the four TPB variables were not consistent for the 12 intervention behaviors. The use of a theoretical framework found to be effective in explaining-and changing-other health-related behaviors, and the inquiry into students' opportunities to intervene to compare against their reported intervention behaviors, is new to this body of literature and contributes to the understanding of the influences of pro-social bystander behavior. © The Author(s) 2016.

Role of the MAPK pathway in the observed bystander effect in lymphocytes co-cultured with macrophages irradiated with γ-rays or carbon ions.

PubMed

Dong, Chen; He, Mingyuan; Ren, Ruiping; Xie, Yuexia; Yuan, Dexiao; Dang, Bingrong; Li, Wenjian; Shao, Chunlin

2015-04-15

The radiation-induced bystander effect (RIBE) has potential implications in cancer risks from space particle radiation; however, the mechanisms underlying RIBE are unclear. The role of the MAPK pathway in the RIBEs of different linear energy transfer (LET) was investigated. Human macrophage U937 cells were irradiated with γ-rays or carbon ions and then co-cultured with nonirradiated HMy2.CIR (HMy) lymphocytes for different periods. The activation of MAPK proteins and the generation of intracellular nitric oxide (NO) and reactive oxygen species (ROS) in the irradiated U937 cells were measured. Micronuclei (MN) formation in the HMy cells was applied to evaluate the bystander damage. Some U937 cells were pretreated with different MAPK inhibitors before irradiation. Additional MN formation was induced in the HMy cells after co-culturing with irradiated U937 cells, and the yield of this bystander MN formation was dependent on the co-culture period with γ-ray irradiation but remained high after 1h of co-culture with carbon irradiation. Further investigations disclosed that the time response of the RIBEs had a relationship with LET, where ERK played a different role from JNK and p38 in regulating RIBEs by regulating the generation of the bystander signaling factors NO and ROS. The finding that the RIBE of high-LET radiation could persist for a much longer period than that of γ-rays implies that particle radiation during space flight could have a high risk of long-term harmful effects. An appropriate intervention targeting the MAPK pathway may have significant implications in reducing this risk. Copyright © 2015 Elsevier Inc. All rights reserved.

A Randomized Controlled Trial of a Multi-Dose Bystander Intervention Program Using Peer Education Theater

ERIC Educational Resources Information Center

McMahon, Sarah; Winter, Samantha C.; Palmer, Jane E.; Postmus, Judy L.; Peterson, N. Andrew; Zucker, Sharon; Koenick, RuthAnne

2015-01-01

This article reports findings from a longitudinal, experimental evaluation of a peer education theater program, Students Challenging Realities and Educating Against Myths (SCREAM) Theater. This study examines the impact of SCREAM Theater on a range of bystander-related outcomes (i.e. bystander intentions, bystander efficacy, perception of friend…

The Effect of Cognitive Behavioral Therapy and Cognitive Behavioral Therapy Plus Media on the Reduction of Bullying and Victimization and the Increase of Empathy and Bystander Response in a Bully Prevention Program for Urban Sixth-Grade Students

ERIC Educational Resources Information Center

McLaughlin, Laura Pierce

2009-01-01

The purpose of this study was to investigate the effect of cognitive behavioral therapy and cognitive behavioral therapy plus media on the reduction of bullying and victimization and the increase in empathy and bystander response in a bully prevention program for urban sixth-graders. Sixty-eight students participated. Because one of the…

Peer bystanders to bullying: who wants to play with the victim?

PubMed

Howard, Anne M; Landau, Steven; Pryor, John B

2014-02-01

Given widespread concern associated with school-based bullying, researchers have looked beyond a dyadic perspective (i.e., bullies and victims only), and now consider the broader social ecology of the peer group. In this research, we examined how the behaviors of peer bystanders influence subsequent reactions to bullies and their victims. Two hundred and six 10- to 15-year-old boys (Mage = 12.46) were invited to play a computer game with three other boys allegedly located at another school. Before the start of the game, participants "met the other players" apparently sitting in a waiting room. These child actors depicted an escalating bullying episode in which the behavior of the bystander was manipulated: aide to the bully, defender of the victim, or passive outsider. Immediately after exposure to the bullying, each participant played a ball toss game (Cyberball) with the three other boys in the video. Individual differences among participants were examined as moderators of the effect of bystander behavior on participants' willingness to include the "victim" in the game. Results indicated that, when exposed to a passive bystander, boys' normative beliefs about aggression, as well as their tendency to morally disengage from observed egregious acts, decreased their willingness to include the victim in the game.

Variations in Involvement: Motivating Bystanders to Care for Senior Citizens

PubMed Central

Keller, Sarah N.; Wilkinson, Tim

2017-01-01

Purpose The purpose of this study was to determine the impact of a senior service advertising campaign designed to increase volunteerism and financial donations among bystanders. Design/methodology/approach A cross-sectional mail survey was administered to 2,500 adults; 384 usable responses were obtained. Survey responses were analyzed by level of exposure and involvement in senior care. Findings High involvement individuals viewed the ads more favorably and exhibited stronger senior caretaking intentions. Low-involvement consumers were less likely to see their own potential contributions to senior care services as effective. Results/implications It is argued that nonparticipants in prosocial helping may fail to notice the need (low awareness), fail to view the cause as urgent (low perceived susceptibility), or have low prior experience with the issue. Practical implications A typology of involvement could be developed that can be used for audience segmentation in marketing health behaviors to bystanders. Originality With limited theoretical and practical guidance on how to motivate bystanders to engage in prosocial behaviors, health communicators and marketers are challenged to tap into the vital resource that bystanders potentially could provide. The research reviewed and presented here indicates hope for engaging the public to become active players in making the nation a safer and healthier place. PMID:28824705

Promoting Prosocial Behaviors to Prevent Dating Violence among College Students: Evaluation of a Bystander Intervention

ERIC Educational Resources Information Center

Borsky, Amanda E.

2014-01-01

The objective of this dissertation was to evaluate a bystander behavior program at the Jefferson College of Health Sciences (JCHS) in Roanoke, Virginia. Specifically, this dissertation examined the: (1) preliminary measurement properties of a newly developed bystander behavior intention scale; (2) impact of the bystander intervention at JCHS; and…

Effect and accuracy of emergency dispatch telephone guidance to bystanders in trauma: post-hoc analysis of a prospective observational study.

PubMed

Bakke, Håkon Kvåle; Steinvik, Tine; Ruud, Håkon; Wisborg, Torben

2017-03-07

Emergency medical communication centres (EMCCs) dispatch and allocate ambulance resources, and provide first-aid guidance to on-scene bystanders. We aimed to 1) evaluate whether dispatcher guidance improved bystander first aid in trauma, and 2) to evaluate whether dispatchers and on-scene emergency medical services (EMS) crews identified the same first aid measures as indicated. For 18 months, the crew on the first EMS crew responding to trauma calls used a standard form to assess bystander first aid. Audio recordings of the corresponding telephone calls from bystanders to the EMCC were reviewed. A total of 311 trauma calls were included. The on-scene EMS crew identified needs for the following first-aid measures: free airway in 26 patients, CPR in 6 patients, and hypothermia prevention in 179 patients. EMCC dispatchers advised these measures, respectively, in 16 (62%), 5 (83%), and 54 (30%) of these cases. Dispatcher guidance was not correlated with correctly performed bystander first aid. For potentially life saving first aid measures, all (20/20) callers who received dispatcher guidance attempted first aid, while only some few (4/22) of the callers who did not receive dispatcher guidance did not attempt first aid. Overall, the EMCC dispatchers had low sensitivity and specificity for correctly identifying trauma patients requiring first-aid measures. Dispatcher guidance did not significantly influence whether on-scene bystander first aid was performed correctly or attempted in this study setting, with a remarkably high willingness to perform first-aid. However, the findings for potentially lifesaving measures suggests that there may be differences that this study was unable to detect. This study found a high rate of first-aid willingness and performance, even without dispatcher prompting, and a low precision in dispatcher advice. This underlines the need for further knowledge about how to increase EMCC dispatchers' possibility to identify trauma patients in need of first aid. The correlation between EMCC-guidance and bystander first aid should be investigated in study settings with lower spontaneous first-aid rates.

Bystander Effects of Ionizing Radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Little, John B.

The objectives of this grant renewal are to provide administrative support and travel funds to allow the continued participation of the principal investigator (Dr. John B. Little) as an advisor to research initiated by several research fellows from his laboratory. The actual research will be carried out under the direction of Dr. Hatsumi Nagasawa with the collaboration of Dr. Joel Bedford at the Colorado State University, and by Drs. Edouard Azzam and Sonia de Toledo at the University of Medicine and Dentistry of New Jersey. Dr. Little will advise on the planning of experiments and development of experimental protocols, themore » analysis of data, and the preparation of manuscripts for publication. The Specific Aims for several of the planned experiments include: 1) to extend studies of the role of recombinational repair in the bystander effect by examining other genes in this pathway and cell lines deficient in excision repair; 2) to continue studies to determine the nature of the damage signal transmitted to bystander cells including the expression of several connexins in the bystander response, and the extent to which the enhanced oxidative metabolism observed in bystander cells may relate to the nature of the transmitted bystander signal; 3) to utilize a genome-wide approach to examine the genetic basis for the hypersensitivity to ionization we have observed in unaffected parents of patients with hereditary retinoblastoma, as well as from a group of apparently normal individuals that show similar radiosensitivity; 4) to complete studies concerning the induction of high frequencies of cells with massive chromosome damage in clonal derivatives of p53 and p21 knockout mouse cell lines; in particular to examine the role of telomere changes in this phenomenon. Overall, the results of these studies should enhance our understanding of the risk of low-dose exposures to ionizing radiation, including human populations to residential radon as well as occupational exposures.« less

Collaborative effects of bystander-initiated cardiopulmonary resuscitation and prehospital advanced cardiac life support by physicians on survival of out-of-hospital cardiac arrest: a nationwide population-based observational study.

PubMed

Yasunaga, Hideo; Horiguchi, Hiromasa; Tanabe, Seizan; Akahane, Manabu; Ogawa, Toshio; Koike, Soichi; Imamura, Tomoaki

2010-01-01

There are inconsistent data about the effectiveness of prehospital physician-staffed advanced cardiac life support (ACLS) on the outcomes of out-of-hospital cardiac arrest (OHCA). Furthermore, the relative importance of bystander-initiated cardiopulmonary resuscitation (BCPR) and ACLS and the effectiveness of their combination have not been clearly demonstrated. Using a prospective, nationwide, population-based registry of all OHCA patients in Japan, we enrolled 95,072 patients whose arrests were witnessed by bystanders and 23,127 patients witnessed by emergency medical service providers between 2005 and 2007. We divided the bystander-witnessed arrest patients into Group A (ACLS by emergency life-saving technicians without BCPR), Group B (ACLS by emergency life-saving technicians with BCPR), Group C (ACLS by physicians without BCPR) and Group D (ACLS by physicians with BCPR). The outcome data included 1-month survival and neurological outcomes determined by the cerebral performance category. Among the 95,072 bystander-witnessed arrest patients, 7,722 (8.1%) were alive at 1 month, including 2,754 (2.9%) with good performance and 3,171 (3.3%) with vegetative status or worse. BCPR occurred in 42% of bystander-witnessed arrests. In comparison with Group A, the rates of good-performance survival were significantly higher in Group B (odds ratio (OR), 2.23; 95% confidence interval, 2.05 to 2.42; P < 0.01) and Group D (OR, 2.80; 95% confidence interval, 2.28 to 3.43; P < 0.01), while no significant difference was seen for Group C (OR, 1.18; 95% confidence interval, 0.86 to 1.61; P = 0.32). The occurrence of vegetative status or worse at 1 month was highest in Group C (OR, 1.92; 95% confidence interval, 1.55 to 2.37; P < 0.01). In this registry-based study, BCPR significantly improved the survival of OHCA with good cerebral outcome. The groups with BCPR and ACLS by physicians had the best outcomes. However, receiving ACLS by physicians without preceding BCPR significantly increased the number of patients with neurologically unfavorable outcomes.

X-irradiation of human bronchial cancer cells causes the bystander effects in normal bronchial cells in vitro.

PubMed

Konopacka, M; Rogoliński, J

2010-01-01

Using X radiation commonly used in radiotherapy of cancers we investigated bystander interactions between human cells: irradiated A549 bronchial carcinoma human cells and non irradiated BEAS-2B normal bronchial epithelial cells. Non irradiated cells were incubated in medium transferred from irradiated A549 cells (ICM-irradiation conditioned medium) for 48h and next the chromosomal damage and apoptosis were estimated. Conditioned medium collected from irradiated cancer cells induced in non irradiated cells of the same line as well as in BEAS-2B normal cells genetic changes such as micronuclei, chromatid and chromosomal breaks and condensation of chromatin characteristic for processes of apoptosis. Addition of only 1% of conditioned medium to fresh medium was sufficient to induction of bystander response to normal bronchial cells. The presented results in this study could have implications for human radiation risk and in evaluating the secondary effects of radiotherapy.

Genetic Signatures of HIV-1 Envelope-mediated Bystander Apoptosis

PubMed Central

Joshi, Anjali; Lee, Raphael T. C.; Mohl, Jonathan; Sedano, Melina; Khong, Wei Xin; Ng, Oon Tek; Maurer-Stroh, Sebastian; Garg, Himanshu

2014-01-01

The envelope (Env) glycoprotein of HIV is an important determinant of viral pathogenesis. Several lines of evidence support the role of HIV-1 Env in inducing bystander apoptosis that may be a contributing factor in CD4+ T cell loss. However, most of the studies testing this phenomenon have been conducted with laboratory-adapted HIV-1 isolates. This raises the question of whether primary Envs derived from HIV-infected patients are capable of inducing bystander apoptosis and whether specific Env signatures are associated with this phenomenon. We developed a high throughput assay to determine the bystander apoptosis inducing activity of a panel of primary Envs. We tested 38 different Envs for bystander apoptosis, virion infectivity, neutralizing antibody sensitivity, and putative N-linked glycosylation sites along with a comprehensive sequence analysis to determine if specific sequence signatures within the viral Env are associated with bystander apoptosis. Our studies show that primary Envs vary considerably in their bystander apoptosis-inducing potential, a phenomenon that correlates inversely with putative N-linked glycosylation sites and positively with virion infectivity. By use of a novel phylogenetic analysis that avoids subtype bias coupled with structural considerations, we found specific residues like Arg-476 and Asn-425 that were associated with differences in bystander apoptosis induction. A specific role of these residues was also confirmed experimentally. These data demonstrate for the first time the potential of primary R5 Envs to mediate bystander apoptosis in CD4+ T cells. Furthermore, we identify specific genetic signatures within the Env that may be associated with the bystander apoptosis-inducing phenotype. PMID:24265318

Adolescent Bystander Behavior in the School and Online Environments and the Implications for Interventions Targeting Cyberbullying

ERIC Educational Resources Information Center

Patterson, Lisa J.; Allan, Alfred; Cross, Donna

2017-01-01

The aim of this study was to add to the emerging knowledge about the role of bystanders in cyberbullying. To differentiate online versus offline bystander behaviors, 292 Australian children (mean age = 15.2; female = 54.4%) reviewed hypothetical scenarios experimentally manipulated by bystander sex, relationship to target and perpetrator, and…

Risk Factors Associated with Peer Victimization and Bystander Behaviors among Adolescent Students.

PubMed

Huang, Zepeng; Liu, Zhenni; Liu, Xiangxiang; Lv, Laiwen; Zhang, Yan; Ou, Limin; Li, Liping

2016-07-27

Despite the prevalence of the phenomena of peer victimization and bystander behaviors, little data has generated to describe their relationships and risk factors. In this paper, a self-administered survey using a cross-sectional cluster-random sampling method in a sample of 5450 participants (2734 girls and 2716 boys) between 4th and 11th grades was conducted at six schools (two primary schools and four middle schools) located in Shantou, China. Self-reported peer victimization, bystander behaviors and information regarding parents' risky behaviors and individual behavioral factors were collected. Multinomial logistic regression analysis was applied to evaluate risk factors affecting peer victimization and bystander behaviors. The results indicated that urban participants were more likely to become bullying victims but less likely to become passive bystanders. Contrarily, bullying victimization was related to the increasing of passive bystander behaviors. Father drinking and mother smoking as independent factors were risk factors for peer victimization. Participants who were smoking or drinking had a tendency to be involved in both peer victimization and passive bystander behaviors. This study suggested that bystander behaviors, victims' and parents' educations play a more important role in peer victimization than previously thought.

Leukocyte function-associated antigen-1-dependent lysis of Fas+ (CD95+/Apo-1+) innocent bystanders by antigen-specific CD8+ CTL.

PubMed

Kojima, H; Eshima, K; Takayama, H; Sitkovsky, M V

1997-09-15

Exquisite specificity toward Ag-bearing cells (cognate targets) is one of the most important properties of CD8+ CTL-mediated cytotoxicity. Using highly Ag-specific CD8+ CTL lines and clones, which spare noncognate, Ag-free targets, we found that in the presence of Ag-bearing targets the CTL acquire the ability to lyse noncognate target cells (bystanders). It is shown that the unexpectedly rapid and efficient lysis of bystanders by Ag-activated CTL is mediated by a Fas ligand (FasL)/Fas-based mechanism and does not depend on perforin. The CTL lysed Fas-expressing bystanders, but spared the Fas-negative or anti-Fas mAb-resistant bystander cells. Accordingly, the FasL-deficient gld/gld CTL did not kill bystanders, while perforin-deficient CTL did. Unlike anti-Fas mAb-induced cell death, the lysis of bystanders was not only FasL/Fas dependent but also required adhesion molecule LFA-1 on the surface of the activated CTL. Lysis of bystanders is viewed as acceptable "collateral" damage, but the persistent presence of activated CTL could result in immunopathologies involving functional Fas-expressing tissues.

The survival benefit of bystander cardiopulmonary resuscitation in a paramedic served metropolitan area.

PubMed Central

Guzy, P M; Pearce, M L; Greenfield, S

1983-01-01

We investigated the survival benefit bystander cardiopulmonary resuscitation (CPR) for out-of-hospital emergencies in a paramedic served area of metropolitan Los Angeles. Clinical information for all events occurring between January 1 and December 31, 1978 was obtained from paramedic report forms and hospital medical records. Bystander CPR was performed for 93 cases and, of these, 20 (22 per cent) survived to hospital discharge, as compared to 7 (5 per cent) of the 150 patients not receiving bystander CPR (p less than 0.001). Twelve (27 per cent) of the 45 patients in ventricular fibrillation (VF) who had bystander CPR survived, as compared to 4 (6 per cent) of 70 VF patients without bystander CPR (p less than 0.01). We conclude that bystander CPR, initiated prior to arrival of paramedics, produced a fourfold improvement in survival. Overall there was a 10 per cent survival rate at hospital discharge. Survival rates reported from Seattle may not necessarily be generalized to larger cities. PMID:6859360

Association of Bystander Cardiopulmonary Resuscitation and Survival According to Ambulance Response Times After Out-of-Hospital Cardiac Arrest.

PubMed

Rajan, Shahzleen; Wissenberg, Mads; Folke, Fredrik; Hansen, Steen Møller; Gerds, Thomas A; Kragholm, Kristian; Hansen, Carolina Malta; Karlsson, Lena; Lippert, Freddy K; Køber, Lars; Gislason, Gunnar H; Torp-Pedersen, Christian

2016-12-20

Bystander-initiated cardiopulmonary resuscitation (CPR) increases patient survival after out-of-hospital cardiac arrest, but it is unknown to what degree bystander CPR remains positively associated with survival with increasing time to potential defibrillation. The main objective was to examine the association of bystander CPR with survival as time to advanced treatment increases. We studied 7623 out-of-hospital cardiac arrest patients between 2005 and 2011, identified through the nationwide Danish Cardiac Arrest Registry. Multiple logistic regression analysis was used to examine the association between time from 911 call to emergency medical service arrival (response time) and survival according to whether bystander CPR was provided (yes or no). Reported are 30-day survival chances with 95% bootstrap confidence intervals. With increasing response times, adjusted 30-day survival chances decreased for both patients with bystander CPR and those without. However, the contrast between the survival chances of patients with versus without bystander CPR increased over time: within 5 minutes, 30-day survival was 14.5% (95% confidence interval [CI]: 12.8-16.4) versus 6.3% (95% CI: 5.1-7.6), corresponding to 2.3 times higher chances of survival associated with bystander CPR; within 10 minutes, 30-day survival chances were 6.7% (95% CI: 5.4-8.1) versus 2.2% (95% CI: 1.5-3.1), corresponding to 3.0 times higher chances of 30-day survival associated with bystander CPR. The contrast in 30-day survival became statistically insignificant when response time was >13 minutes (bystander CPR vs no bystander CPR: 3.7% [95% CI: 2.2-5.4] vs 1.5% [95% CI: 0.6-2.7]), but 30-day survival was still 2.5 times higher associated with bystander CPR. Based on the model and Danish out-of-hospital cardiac arrest statistics, an additional 233 patients could potentially be saved annually if response time was reduced from 10 to 5 minutes and 119 patients if response time was reduced from 7 (the median response time in this study) to 5 minutes. The absolute survival associated with bystander CPR declined rapidly with time. Yet bystander CPR while waiting for an ambulance was associated with a more than doubling of 30-day survival even in case of long ambulance response time. Decreasing ambulance response time by even a few minutes could potentially lead to many additional lives saved every year. © 2016 American Heart Association, Inc.

A composite microdose Adaptive Response (AR) and Bystander Effect (BE) model-application to low LET and high LET AR and BE data.

PubMed

Leonard, Bobby E

2008-08-01

It has been suggested that Adaptive Response (AR) may reduce risk of adverse health effects due to ionizing radiation. But very low dose Bystander Effects (BE) may impose dominant deleterious human risks. These conflicting behaviors have stimulated controversy regarding the Linear No-Threshold human risk model. A dose and dose rate-dependent microdose model, to examine AR behavior, was developed in prior work. In the prior work a number of in vitro and in vivo dose response data were examined with the model. Recent new data show AR behavior with some evidence of very low dose BE. The purpose of this work is to supplement the microdose model to encompass the Brenner and colleagues BaD (Bystander and Direct Damage) model and apply this composite model to obtain new knowledge regarding AR and BE and illustrate the use of the model to plan radio-biology experiments. The biophysical composite AR and BE Microdose Model quantifies the accumulation of hits (Poisson distributed, microdose specific energy depositions) to cell nucleus volumes. This new composite AR and BE model provides predictions of dose response at very low dose BE levels, higher dose AR levels and even higher dose Direct (linear-quadratic) Damage radiation levels. We find good fits of the model to both BE data from the Columbia University microbeam facility and combined AR and BE data for low Linear Energy Transfer (LET) and high LET data. A Bystander Factor of about 27,000 and an AR protection factor of 0.61 are obtained for the low LET in vivo mouse spleen exposures. A Bystander Factor of 317 and an AR protection factor of 0.53 are obtained for high LET radon alpha particles in human lymphocytes. In both cases the AR is activated at most by one or two radiation induced charged particle traversals through the cell nucleus. The results of the model analysis is consistent with a premise that both Bystander damage and Adaptive Response radioprotection can occur in the same cell type, derived from the same cell species. The model provides an analytical tool to biophysically study the combined effects of BE and AR.

Workplace mobbing and bystanders' helping behaviour towards victims: the role of gender, perceived responsibility and anticipated stigma by association.

PubMed

Mulder, Roelie; Pouwelse, Mieneke; Lodewijkx, Hein; Bolman, Catherine

2014-08-01

We examined victims' perceived responsibility and bystanders' anticipated risk of being victimized themselves when others associate them with the victim (stigma by association, SBA) as possible antecedents of bystanders' helping behaviour towards a victim of workplace mobbing, and explored the effects of gender. Guided by the attribution model of social conduct (Weiner, 2006), a 2 × 2 vignette experiment was conducted. Participants were Dutch regional government employees (N = 161). Path analyses generally supported the hypotheses, but showed different results for women and men. In the strong (Vs. weak) responsibility condition, women reported less sympathy and more anger and men only more anger, which resulted in lower helping intention. Additionally, for men the results showed an unexpected direct positive effect of responsibility on helping intention. Furthermore, in the strong SBA condition, women and men reported more fear and men, unexpectedly, more anger. Consequently, helping intention decreased. The findings on gender are discussed in the context of social role theory, gender and emotion. Our findings suggest that to prevent and tackle mobbing, organizations and professionals should be aware of the attributional and emotional processes and gender differences in bystanders' helping behaviour. © 2013 International Union of Psychological Science.

Non-targeted and delayed effects of exposure to ionizing radiation: I. Radiation-induced genomic instability and bystander effects in vitro

NASA Technical Reports Server (NTRS)

Morgan, William F.

2003-01-01

A long-standing dogma in the radiation sciences is that energy from radiation must be deposited in the cell nucleus to elicit a biological effect. A number of non-targeted, delayed effects of ionizing radiation have been described that challenge this dogma and pose new challenges to evaluating potential hazards associated with radiation exposure. These effects include induced genomic instability and non-targeted bystander effects. The in vitro evidence for non-targeted effects in radiation biology will be reviewed, but the question as to how one extrapolates from these in vitro observations to the risk of radiation-induced adverse health effects such as cancer remains open.

Receiving Post-Conflict Affiliation from the Enemy's Friend Reconciles Former Opponents

PubMed Central

Wittig, Roman M.; Boesch, Christophe

2010-01-01

The adaptive function of bystander initiated post-conflict affiliation (also: consolation & appeasement) has been debated for 30 years. Three influential hypotheses compete for the most likely explanation but have not previously been tested with a single data set. The consolation hypothesis argues that bystander affiliation calms the victim and reduces their stress levels. The self-protection hypothesis proposes that a bystander offers affiliation to either opponent to protect himself from redirected aggression by this individual. The relationship-repair hypothesis suggests a bystander can substitute for a friend to reconcile the friend with the friend's former opponent. Here, we contrast all three hypotheses and tested their predictions with data on wild chimpanzees (Pan troglodytes verus) of the Taï National Park, Côte d'Ivoire. We examined the first and second post-conflict interactions with respect to both the dyadic and triadic relationships between the bystander and the two opponents. Results showed that female bystanders offered affiliation to their aggressor friends and the victims of their friends, while male bystanders offered affiliation to their victim friends and the aggressors of their friends. For both sexes, bystander affiliation resulted in a subsequent interaction pattern that is expected for direct reconciliation. Bystander affiliation offered to the opponent's friend was more likely to lead to affiliation among opponents in their subsequent interaction. Also, tolerance levels among former opponents were reset to normal levels. In conclusion, this study provides strong evidence for the relationship-repair hypothesis, moderate evidence for the consolation hypothesis and no evidence for the self-protection hypothesis. Furthermore, that bystanders can repair a relationship on behalf of their friend indicates that recipient chimpanzees are aware of the relationships between others, even when they are not kin. This presents a mechanism through which chimpanzees may gain benefits from social knowledge. PMID:21085592

We need to include bystander first aid in trauma research.

PubMed

Bakke, Håkon Kvåle; Wisborg, Torben

2017-03-23

The chain of trauma survival is a concept that originated in the area of out-of-hospital cardiac arrest (OHCA) and was adapted to the treatment of trauma. In out-of-hospital cardiac arrest research into bystander first aid has resulted in improved outcome. Whereas, in trauma research the first link of the chain of survival is almost ignored. In OHCA, cardiopulmonary resuscitation (CPR) from bystanders has been subject of a vast amount of research, as well as measures and programs to raise the rate of bystander CPR to cardiac arrest victims. These efforts have resulted in improved survival. The research effort has been well grounded in the research community, as demonstrated by its natural inclusion in the uniform reporting template (Utstein) for the treatment of OHCA. In trauma the bystander may contribute by providing an open airway, staunch bleedings, or prevent hypothermia. In trauma however, while the chain of survival has been adopted along with it distinct links, including bystander first aid, the consensus-based uniform reporting template for trauma (the Utstein template) does not include the bystander first aid efforts. There is extremely little research on what first aid measures bystanders provide to trauma victims, and on what impact such measures have on outcome. An important step to improve research on bystander first aid in trauma would be to include this as part of the uniform reporting template for trauma CONCLUSION: The lack of research on bystander first aid makes the first link in the trauma chain of survival the weakest link. We, the trauma research community, should either improve our research and knowledge in this area, or remove the link from the chain of survival.

A heterotypic bystander effect for tumor cell killing after adeno-associated virus/phage-mediated, vascular-targeted suicide gene transfer.

PubMed

Trepel, Martin; Stoneham, Charlotte A; Eleftherohorinou, Hariklia; Mazarakis, Nicholas D; Pasqualini, Renata; Arap, Wadih; Hajitou, Amin

2009-08-01

Suicide gene transfer is the most commonly used cytotoxic approach in cancer gene therapy; however, a successful suicide gene therapy depends on the generation of efficient targeted systemic gene delivery vectors. We recently reported that selective systemic delivery of suicide genes such as herpes simplex virus thymidine kinase (HSVtk) to tumor endothelial cells through a novel targeted adeno-associated virus/phage vector leads to suppression of tumor growth. This marked effect has been postulated to result primarily from the death of cancer cells by hypoxia following the targeted disruption of tumor blood vessels. Here, we investigated whether an additional mechanism of action is involved. We show that there is a heterotypic "bystander" effect between endothelial cells expressing the HSVtk suicide gene and tumor cells. Treatment of cocultures of HSVtk-transduced endothelial cells and non-HSVtk-transduced tumor cells with ganciclovir results in the death of both endothelial and tumor cells. Blocking of this effect by 18alpha-glycyrrhetinic acid indicates that gap junctions between endothelial and tumor cells are largely responsible for this phenomenon. Moreover, the observed bystander killing is mediated by connexins 43 and 26, which are expressed in endothelial and tumor cell types. Finally, this heterotypic bystander effect is accompanied by a suppression of tumor growth in vivo that is independent of primary gene transfer into host-derived tumor vascular endothelium. These findings add an alternative nonmutually exclusive and potentially synergistic cytotoxic mechanism to cancer gene therapy based on targeted adeno-associated virus/phage and further support the promising role of nonmalignant tumor stromal cells as therapeutic targets.

Prosocial Bystander Behavior in Bullying Dynamics: Assessing the Impact of Social Capital.

PubMed

Evans, Caroline B R; Smokowski, Paul R

2015-12-01

Individuals who observe a bullying event, but are not directly involved as a bully or victim, are referred to as bystanders. Prosocial bystanders are those individuals who actively intervene in bullying dynamics to support the victim and this prosocial behavior often ends the bullying. The current study examines how social capital in the form of social support, community engagement, mental health functioning, and positive school experiences and characteristics is associated with the likelihood of engaging in prosocial bystander behavior in a large sample (N = 5752; 51.03% female) of racially/ethnically diverse rural youth. It was hypothesized that social capital would be associated with an increased likelihood of engaging in prosocial bystander behavior. Following multiple imputation, an ordered logistic regression with robust standard errors was run. The hypothesis was partially supported and results indicated that social capital in the form of friend and teacher support, ethnic identity, religious orientation, and future optimism were significantly associated with an increased likelihood of engaging in prosocial bystander behavior. Contrary to the hypothesis, a decreased rate of self-esteem was significantly associated with an increased likelihood of engaging in prosocial bystander behavior. The findings highlight the importance of positive social relationships and community engagement in increasing prosocial bystander behavior and ultimately decreasing school bullying. Implications were discussed.

Effect of modeled microgravity on UV-C-induced interplant communication of Arabidopsis thaliana.

PubMed

Wang, Ting; Xu, Wei; Li, Huasheng; Deng, Chenguang; Zhao, Hui; Wu, Yuejin; Liu, Min; Wu, Lijun; Lu, Jinying; Bian, Po

2017-12-01

Controlled ecological life support systems (CELSS) will be an important feature of long-duration space missions of which higher plants are one of the indispensable components. Because of its pivotal role in enabling plants to cope with environmental stress, interplant communication might have important implications for the ecological stability of such CELSS. However, the manifestations of interplant communication in microgravity conditions have yet to be fully elucidated. To address this, a well-established Arabidopsis thaliana co-culture experimental system, in which UV-C-induced airborne interplant communication is evaluated by the alleviation of transcriptional gene silencing (TGS) in bystander plants, was placed in microgravity modeled by a two-dimensional rotating clinostat. Compared with plants under normal gravity, TGS alleviation in bystander plants was inhibited in microgravity. Moreover, TGS alleviation was also prevented when plants of the pgm-1 line, which are impaired in gravity sensing, were used in either the UV-C-irradiated or bystander group. In addition to the specific TGS-loci, interplant communication-shaped genome-wide DNA methylation in bystander plants was altered under microgravity conditions. These results indicate that interplant communications might be modified in microgravity. Time course analysis showed that microgravity interfered with both the production of communicative signals in UV-C-irradiated plants and the induction of epigenetic responses in bystander plants. This was further confirmed by the experimental finding that microgravity also prevented the response of bystander plants to exogenous methyl jasmonate (JA) and methyl salicylate (SA), two well-known airborne signaling molecules, and down-regulated JA and SA biosynthesis in UV-C-irradiated plants. Copyright © 2017 Elsevier B.V. All rights reserved.

Role of TGF-β1 and nitric oxide in the bystander response of irradiated glioma cells

PubMed Central

Shao, C; Folkard, M; Prise, KM

2010-01-01

The radiation-induced bystander effect (RIBE) increases the probability of cellular response and therefore has important implications for cancer risk assessment following low-dose irradiation and for the likelihood of secondary cancers after radiotherapy. However, our knowledge of bystander signaling factors, especially those having long half-lives, is still limited. The present study found that, when a fraction of cells within a glioblastoma population were individually irradiated with helium ions from a particle microbeam, the yield of micronuclei (MN) in the nontargeted cells was increased, but these bystander MN were eliminated by treating the cells with either aminoguanidine (an inhibitor of inducible nitric oxide (NO) synthase) or anti-transforming growth factor β1 (anti-TGF-β1), indicating that NO and TGF-β1 are involved in the RIBE. Intracellular NO was detected in the bystander cells, and additional TGF-β1 was detected in the medium from irradiated T98G cells, but it was diminished by aminoguanidine. Consistent with this, an NO donor, diethylamine nitric oxide (DEANO), induced TGF-β1 generation in T98G cells. Conversely, treatment of cells with recombinant TGF-β1 could also induce NO and MN in T98G cells. Treatment of T98G cells with anti-TGF-β1 inhibited the NO production when only 1% of cells were targeted, but not when 100% of cells were targeted. Our results indicate that, downstream of radiation-induced NO, TGF-β1 can be released from targeted T98G cells and plays a key role as a signaling factor in the RIBE by further inducing free radicals and DNA damage in the nontargeted bystander cells. PMID:17621264

The impact of ultra-brief chest compression-only CPR video training on responsiveness, compression rate, and hands-off time interval among bystanders in a shopping mall.

PubMed

Panchal, Ashish R; Meziab, Omar; Stolz, Uwe; Anderson, Wes; Bartlett, Mitchell; Spaite, Daniel W; Bobrow, Bentley J; Kern, Karl B

2014-09-01

Recent studies have demonstrated higher-quality chest compressions (CCs) following a 60 s ultra-brief video (UBV) on compression-only CPR (CO-CPR). However, the effectiveness of UBVs as a CPR-teaching tool for lay bystanders in public venues remains unknown. Determine whether an UBV is effective in teaching laypersons CO-CPR in a public setting and if viewing leads to superior responsiveness and CPR skills. Adult lay bystanders were enrolled in a public shopping mall and randomized to: (1) Control (CTR): sat idle for 60 s; (2) UBV: watched a 60 s UBV on CO-CPR. Subjects were read a scenario detailing a sudden collapse in the mall and asked to do what they "thought was best" on a mannequin. Performance measures were recorded for 2 min: responsiveness (time to call 911 and first CCs) and CPR quality [CC depth, rate, hands-off interval (time without CC after first CC)]. One hundred subjects were enrolled. Demographics were similar between groups. UBV subjects called 911 more frequently (percent difference: 31%) and initiated CCs sooner in the arrest scenario (median difference (MD): 5 s). UBV cohort had increased CC rate (MD: 19 cpm) and decreased hands-off interval (MD: 27 s). There was no difference in CC depth. Bystanders with UBV training in a shopping mall had significantly improved responsiveness, CC rate, and decreased hands-off interval. Given the short length of training, UBV may have potential as a ubiquitous intervention for public venues to help improve bystander reaction to arrest and CO-CPR performance. Published by Elsevier Ireland Ltd.

Bystander Intervention Among College Men: The Role of Alcohol and Correlates of Sexual Aggression.

PubMed

Orchowski, Lindsay M; Berkowitz, Alan; Boggis, Jesse; Oesterle, Daniel

2016-10-01

Current efforts to reduce sexual violence in college campuses underscore the role of engaging men in prosocial bystander behavior. The current study implemented an online survey to explore associations between engaging in heavy drinking and attitudes toward bystander intervention among a sample of college men (N = 242). Correlates of sexual aggression were also explored as mediators of the hypothesized relationship between engaging in heavy drinking and attitudes toward bystander intervention. Data indicated that men who engaged in two or more episodes of heavy drinking over the past month reported lower prosocial bystander attitudes compared with men who did not engage in such behavior. The association between engaging in heavy drinking and lower prosocial bystander attitudes was mediated by men's perception of their peers' approval for sexual aggression, their own comfort with sexism, and engagement in coercive sexual behavior. Implications for sexual assault prevention are discussed. © The Author(s) 2015.

Proteomic overview and perspectives of the radiation-induced bystander effects.

PubMed

Chevalier, François; Hamdi, Dounia Houria; Saintigny, Yannick; Lefaix, Jean-Louis

2015-01-01

Radiation proteomics is a recent, promising and powerful tool to identify protein markers of direct and indirect consequences of ionizing radiation. The main challenges of modern radiobiology is to predict radio-sensitivity of patients and radio-resistance of tumor to be treated, but considerable evidences are now available regarding the significance of a bystander effect at low and high doses. This "radiation-induced bystander effect" (RIBE) is defined as the biological responses of non-irradiated cells that received signals from neighboring irradiated cells. Such intercellular signal is no more considered as a minor side-effect of radiotherapy in surrounding healthy tissue and its occurrence should be considered in adapting radiotherapy protocols, to limit the risk for radiation-induced secondary cancer. There is no consensus on a precise designation of RIBE, which involves a number of distinct signal-mediated effects within or outside the irradiated volume. Indeed, several cellular mechanisms were proposed, including the secretion of soluble factors by irradiated cells in the extracellular matrix, or the direct communication between irradiated and neighboring non-irradiated cells via gap junctions. This phenomenon is observed in a context of major local inflammation, linked with a global imbalance of oxidative metabolism which makes its analysis challenging using in vitro model systems. In this review article, the authors first define the radiation-induced bystander effect as a function of radiation type, in vitro analysis protocols, and cell type. In a second time, the authors present the current status of protein biomarkers and proteomic-based findings and discuss the capacities, limits and perspectives of such global approaches to explore these complex intercellular mechanisms. Copyright © 2014 Elsevier B.V. All rights reserved.

Low-dose energetic protons induce adaptive and bystander effects that protect human cells against DNA damage caused by a subsequent exposure to energetic iron ions

PubMed Central

Buonanno, Manuela; De Toledo, Sonia M.; Howell, Roger W.; Azzam, Edouard I.

2015-01-01

During interplanetary missions, astronauts are exposed to mixed types of ionizing radiation. The low ‘flux’ of the high atomic number and high energy (HZE) radiations relative to the higher ‘flux’ of low linear energy transfer (LET) protons makes it highly probable that for any given cell in the body, proton events will precede any HZE event. Whereas progress has been made in our understanding of the biological effects of low-LET protons and high-LET HZE particles, the interplay between the biochemical processes modulated by these radiations is unclear. Here we show that exposure of normal human fibroblasts to a low mean absorbed dose of 20 cGy of 0.05 or 1-GeV protons (LET ∼ 1.25 or 0.2 keV/μm, respectively) protects the irradiated cells (P < 0.0001) against chromosomal damage induced by a subsequent exposure to a mean absorbed dose of 50 cGy from 1 GeV/u iron ions (LET ∼ 151 keV/μm). Surprisingly, unirradiated (i.e. bystander) cells with which the proton-irradiated cells were co-cultured were also significantly protected from the DNA-damaging effects of the challenge dose. The mitigating effect persisted for at least 24 h. These results highlight the interactions of biological effects due to direct cellular traversal by radiation with those due to bystander effects in cell populations exposed to mixed radiation fields. They show that protective adaptive responses can spread from cells targeted by low-LET space radiation to bystander cells in their vicinity. The findings are relevant to understanding the health hazards of space travel. PMID:25805407

Non-targeted effects of ionizing radiation–implications for low dose risk

PubMed Central

Kadhim, Munira; Salomaa, Sisko; Wright, Eric; Hildebrandt, Guido; Belyakov, Oleg V.; Prise, Kevin M.; Little, Mark P.

2014-01-01

Non-DNA targeted effects of ionizing radiation, which include genomic instability, and a variety of bystander effects including abscopal effects and bystander mediated adaptive response, have raised concerns about the magnitude of low-dose radiation risk. Genomic instability, bystander effects and adaptive responses are powered by fundamental, but not clearly understood systems that maintain tissue homeostasis. Despite excellent research in this field by various groups, there are still gaps in our understanding of the likely mechanisms associated with non-DNA targeted effects, particularly with respect to systemic (human health) consequences at low and intermediate doses of ionizing radiation. Other outstanding questions include links between the different non-targeted responses and the variations in response observed between individuals and cell lines, possibly a function of genetic background. Furthermore, it is still not known what the initial target and early interactions in cells are that give rise to non-targeted responses in neighbouring or descendant cells. This paper provides a commentary on the current state of the field as a result of the Non-targeted effects of ionizing radiation (NOTE) Integrated Project funded by the European Union. Here we critically examine the evidence for non-targeted effects, discuss apparently contradictory results and consider implications for low-dose radiation health effects. PMID:23262375

Evaluation of the Green Dot Bystander Intervention to Reduce Interpersonal Violence Among College Students Across Three Campuses.

PubMed

Coker, Ann L; Fisher, Bonnie S; Bush, Heather M; Swan, Suzanne C; Williams, Corrine M; Clear, Emily R; DeGue, Sarah

2015-12-01

Evidence suggests that interventions to engage bystanders in violence prevention increase bystander intentions and efficacy to intervene, yet the impact of such programs on violence remains unknown. This study compared rates of violence by type among undergraduate students attending a college campus with the Green Dot bystander intervention (n = 2,768) with students at two colleges without bystander programs (n = 4,258). Violent victimization rates were significantly (p < .01) lower among students attending the campus with Green Dot relative to the two comparison campuses. Violence perpetration rates were lower among males attending the intervention campus. Implications of these results for research and practice are discussed. © The Author(s) 2014.

Students as Prosocial Bystanders to Sexual Assault: Demographic Correlates of Intervention Norms, Intentions, and Missed Opportunities.

PubMed

Hoxmeier, Jill C; Acock, Alan C; Flay, Brian R

2017-01-01

Sexual assault is a major public health issue. Bystander engagement programs are becoming widely used to combat sexual assault on college campuses. The purpose of this study was to examine students' intervention norms, intentions, opportunities, and behaviors as bystanders to sexual assault. Undergraduate students ( N = 779) completed the Sexual Assault Bystander Behavior Questionnaire in the fall of 2014. The t tests revealed differences in students' intervention norms, intentions, opportunities, and missed opportunities based on sex, race/ethnicity, athletic participation, and fraternity/sorority membership. The findings support the use of additional measures to assess bystander behavior and to identify student subpopulations that may benefit from programs aimed at increasing prosocial intervention.

Evaluation of the Green Dot Bystander Intervention to Reduce Interpersonal Violence Among College Students Across Three Campuses

PubMed Central

Coker, Ann L.; Fisher, Bonnie S.; Bush, Heather M.; Swan, Suzanne C.; Williams, Corrine M.; Clear, Emily R.; DeGue, Sarah

2018-01-01

Evidence suggests that interventions to engage bystanders in violence prevention increase bystander intentions and efficacy to intervene, yet the impact of such programs on violence remains unknown. This study compared rates of violence by type among undergraduate students attending a college campus with the Green Dot bystander intervention (n = 2,768) with students at two colleges without bystander programs (n = 4,258). Violent victimization rates were significantly (p < .01) lower among students attending the campus with Green Dot relative to the two comparison campuses. Violence perpetration rates were lower among males attending the intervention campus. Implications of these results for research and practice are discussed. PMID:25125493

Activation of caspase-3 noninvolved in the bystander effect of the herpes simplex virus thymidine kinase gene/ganciclovir (HSV-tk/GCV) system.

PubMed

Zhang, Zhihong; Lin, Juqiang; Chu, Jun; Ma, Yan; Zeng, Shaoqun; Luo, Qingming

2008-01-01

Use of the herpes simplex virus thymidine kinase gene/ganciclovir (HSV-tk/GCV) system is one of the promising approaches in the rapidly growing area of gene therapy. The "bystander effect," a phenomenon in which HSV-tk+ cells exposed to GCV are toxic to adjacent HSV-tk- cells, was reported to play an important role in suicide gene therapy. However, the mechanism by which HSV-tk/GCV induces the bystander effect is poorly understood. We monitored the activation of caspase-3 in living cells induced by the HSV-tk/GCV system using a genetically encoded fluorescence resonance energy transfer (FRET) probe CD3, , a caspase-3 recognition site fused with a cyan fluorescent protien (CFP) and a red fluorescent protein (DsRed) which we reported and named in a previous paper. Fluorescence protein (FP)-based multicolor cellular labeling, combined with the multichannel fluorescence imaging and FRET imaging techniques, provides a novel and improved approach to directly determine whether the activation of caspase-3 involved in the HSV-tk/GCV system induces cell apoptosis in tk gene-expressing cells and their neighboring cells. FRET ratio images of CD3, and fluorescence images of the fusion protein of thymidine kinase linked with green fluorescent protein (TK-GFP), indicated that HSV-tk/GCV system-induced apoptosis in human adenoid cystic carcinoma (ACC-M) cells was via a caspase-3 pathway, and the activation of caspase-3 was not involved in the bystander effect of HSV-tk/GCV system.

Human Lung Cancer Risks from Radon – Part III - Evidence of Influence of Combined Bystander and Adaptive Response Effects on Radon Case-Control Studies - A Microdose Analysis

PubMed Central

Leonard, Bobby E.; Thompson, Richard E.; Beecher, Georgia C.

2012-01-01

Since the publication of the BEIR VI (1999) report on health risks from radon, a significant amount of new data has been published showing various mechanisms that may affect the ultimate assessment of radon as a carcinogen, in particular the potentially deleterious Bystander Effect (BE) and the potentially beneficial Adaptive Response radio-protection (AR). The case-control radon lung cancer risk data of the pooled 13 European countries radon study (Darby et al 2005, 2006) and the 8 North American pooled study (Krewski et al 2005, 2006) have been evaluated. The large variation in the odds ratios of lung cancer from radon risk is reconciled, based on the large variation in geological and ecological conditions and variation in the degree of adaptive response radio-protection against the bystander effect induced lung damage. The analysis clearly shows Bystander Effect radon lung cancer induction and Adaptive Response reduction in lung cancer in some geographical regions. It is estimated that for radon levels up to about 400 Bq m−3 there is about a 30% probability that no human lung cancer risk from radon will be experienced and a 20% probability that the risk is below the zero-radon, endogenic spontaneous or perhaps even genetically inheritable lung cancer risk rate. The BEIR VI (1999) and EPA (2003) estimates of human lung cancer deaths from radon are most likely significantly excessive. The assumption of linearity of risk, by the Linear No-Threshold Model, with increasing radon exposure is invalid. PMID:22942874

Cellular communication and “non-targeted effects”: Modelling approaches

NASA Astrophysics Data System (ADS)

Ballarini, Francesca; Facoetti, Angelica; Mariotti, Luca; Nano, Rosanna; Ottolenghi, Andrea

2009-10-01

During the last decade, a large number of experimental studies on the so-called "non-targeted effects", in particular bystander effects, outlined that cellular communication plays a significant role in the pathways leading to radiobiological damage. Although it is known that two main types of cellular communication (i.e. via gap junctions and/or molecular messengers diffusing in the extra-cellular environment, such as cytokines, NO etc.) play a major role, it is of utmost importance to better understand the underlying mechanisms, and how such mechanisms can be modulated by ionizing radiation. Though the "final" goal is of course to elucidate the in vivo scenario, in the meanwhile also in vitro studies can provide useful insights. In the present paper we will discuss key issues on the mechanisms underlying non-targeted effects and cell communication, for which theoretical models and simulation codes can be of great help. In this framework, we will present in detail three literature models, as well as an approach under development at the University of Pavia. More specifically, we will first focus on a version of the "State-Vector Model" including bystander-induced apoptosis of initiated cells, which was successfully fitted to in vitro data on neoplastic transformation supporting the hypothesis of a protective bystander effect mediated by apoptosis. The second analyzed model, focusing on the kinetics of bystander effects in 3D tissues, was successfully fitted to data on bystander damage in an artificial 3D skin system, indicating a signal range of the order of 0.7-1 mm. A third model for bystander effect, taking into account of spatial location, cell killing and repopulation, showed dose-response curves increasing approximately linearly at low dose rates but quickly flattening out for higher dose rates, also predicting an effect augmentation following dose fractionation. Concerning the Pavia approach, which can model the release, diffusion and depletion/degradation of candidate signals (e.g. cytokines) travelling in the extra-cellular environment, the good agreement with ad hoc experimental data obtained in our laboratory validated the adopted approach, which in the future can be applied also to other candidate signals. Although the available information is still not sufficient to decide whether the Linear No Threshold approach for low dose risk - including space radiation risk - has to be modified, these studies confirmed the need of a paradigm shift in (low-dose) radiobiology, where the DNA-centric vision needs to be integrated by a wider vision where cells constitute an organized population responding to external stimuli in a collective fashion, communicating by means of different molecular signals. Further studies, in particular in vivo (or at least in 3D tissues) and possibly combined with human epidemiological data, will be crucial to help solving such questions in the future.

That's What Friends Are For: Bystander Responses to Friends or Strangers at Risk for Party Rape Victimization.

PubMed

Katz, Jennifer; Pazienza, Rena; Olin, Rachel; Rich, Hillary

2015-10-01

The present research examined bystander responses to potential party rape scenarios involving either a friend or a stranger at risk. Undergraduate students (N = 151) imagined attending a party and seeing a man lead an intoxicated woman (friend or stranger) into a bedroom. After random assignment to conditions, participants reported on intentions to help, barriers to helping, victim blame, and empathic concern. As expected, based on their shared social group membership, bystanders intended to offer more help to friends than to strangers. Bystanders also reported more personal responsibility to help and more empathic concern when the potential victim was a friend rather than stranger. Observing a friend versus stranger at risk did not affect audience inhibition or perceived victim blame. Compared with women, men reported more blame and less empathic concern for potential victims. However, there were no gender differences in bystander intent to help or barriers to helping. In multivariate analyses, both responsibility to help and empathic concern for the potential victim uniquely predicted bystanders' intent to help a woman at risk for party rape. Results suggest that promoting social identification with peers at risk could increase bystander intervention. © The Author(s) 2014.

Determinants of self-reported bystander behavior in cyberbullying incidents amongst adolescents.

PubMed

DeSmet, Ann; Veldeman, Charlene; Poels, Karolien; Bastiaensens, Sara; Van Cleemput, Katrien; Vandebosch, Heidi; De Bourdeaudhuij, Ilse

2014-04-01

This study explores behavioral determinants of self-reported cyberbullying bystander behavior from a behavioral change theoretical perspective, to provide levers for interventions. Nine focus groups were conducted with 61 young adolescents (aged 12-16 years, 52% girls). Assertive defending, reporting to others, providing advice, and seeking support were the most mentioned behaviors. Self-reported bystander behavior heavily depended on contextual factors, and should not be considered a fixed participant role. Bystanders preferred to handle cyberbullying offline and in person, and comforting the victim was considered more feasible than facing the bully. Most prevailing behavioral determinants to defend or support the victim were low moral disengagement, that the victim is an ingroup member, and that the bystander is popular. Youngsters felt they received little encouragement from their environment to perform positive bystanding behavior, since peers have a high acceptance for not defending and perceived parental support for defending behavior is largely lacking. These results suggest multilevel models for cyberbullying research, and interventions are needed. With much previous research into cyberbullying insufficiently founded in theoretical models, the employed framework of the Integrative Model and Social Cognitive Theory may inspire future studies into bystander behavior.

Human Lung Cancer Risks from Radon – Part I - Influence from Bystander Effects - A Microdose Analysis

PubMed Central

Leonard, Bobby E.; Thompson, Richard E.; Beecher, Georgia C.

2010-01-01

Since the publication of the BEIR VI report in 1999 on health risks from radon, a significant amount of new data has been published showing various mechanisms that may affect the ultimate assessment of radon as a carcinogen, at low domestic and workplace radon levels, in particular the Bystander Effect (BE) and the Adaptive Response radio-protection (AR). We analyzed the microbeam and broadbeam alpha particle data of Miller et al. (1995, 1999), Zhou et al. (2001, 2003, 2004), Nagasawa and Little (1999, 2002), Hei et al. (1999), Sawant et al. (2001a) and found that the shape of the cellular response to alphas is relatively independent of cell species and LET of the alphas. The same alpha particle traversal dose response behavior should be true for human lung tissue exposure to radon progeny alpha particles. In the Bystander Damage Region of the alpha particle response, there is a variation of RBE from about 10 to 35. There is a transition region between the Bystander Damage Region and Direct Damage Region of between one and two microdose alpha particle traversals indicating that perhaps two alpha particle “hits” are necessary to produce the direct damage. Extrapolation of underground miners lung cancer risks to human risks at domestic and workplace levels may not be valid. PMID:21731539

Fas Ligand-Mediated Lysis of Self Bystander Targets by Human Papillomavirus-Specific CD8+ Cytotoxic T Lymphocytes

PubMed Central

Smyth, Mark J.; Krasovskis, Erika; Johnstone, Ricky W.

1998-01-01

Mouse cytotoxic T lymphocytes (CTL) reactive with a H-2Db-presented 9-mer peptide of the human papillomavirus type 16 protein E749-57 (RAHYNIVTF) were generated from the spleen cells of wild-type C57BL/6 (B6) or B6 perforin-deficient (B6.P0) mice. CD8+ B6 CTL displayed peptide-specific perforin- and Fas-mediated lysis of E7-transfected mouse RMA lymphoma cells (RMA-E7), while CD8+ CTL from B6.P0 mice lysed RMA-E7 cells via Fas ligand (FasL) exclusively. Rapid and efficient lysis of syngeneic bystander B6 blasts or RMA cells by either B6 or B6.P0 Ag-activated CTL was mediated by a FasL-Fas mechanism. Fas-resistant bystanders were not lysed, nor were allogeneic Fas-sensitive C3H/HeJ (H-2k) or BALB/c (H-2d) bystander blasts. Interestingly, however, phorbol myristate acetate-ionomycin preactivation of B6.P0 effectors enabled lysis of allogeneic H-2k and H-2d bystanders even in the absence of antigenic stimulation. Lysis of syngeneic bystander cells was always FasL-Fas dependent and required effector-bystander contact and, in particular, an interaction between CTL LFA-1 and bystander ICAM-1. Thus, in the context of major histocompatibility complex class I molecule-peptide ligation of the T-cell receptors of CD8+ CTL, neighboring bystander cells that are syngeneic and Fas sensitive and express the adhesion molecule ICAM-1 are potential targets of CTL attack. PMID:9621057

Implications for sexual assault prevention: college students as prosocial bystanders.

PubMed

Exner, Deinera; Cummings, Nina

2011-01-01

Prosocial bystander interventions are promising approaches to sexual assault prevention on college campuses. To assess bystander attitudes among undergraduate students at a northeastern university. A convenience sample of 188 students from 4 undergraduate classes was surveyed during regularly scheduled class sessions. Participants completed a short survey on bystander efficacy, readiness to change, and barriers to intervention prior to the start of class. The majority of students were not involved in activities or programs focused on sexual assault prevention. Although students agreed that violence could be prevented, they perceived many barriers to their own participation in intervention. There is a need for gender-targeted prevention programming that introduces the idea of prosocial bystander intervention, with a focus on increasing self-efficacy and lowering barriers.

Participation in High School Sports and Bystander Intentions, Efficacy to Intervene, and Rape Myth Beliefs.

PubMed

McMahon, Sarah

2015-10-01

Debate exists as to whether male athletes are more prone to commit acts of sexual violence and maintain problematic attitudes about sexual assault. To contribute to the literature on this relationship, this study posed the following research questions: (1) Do those students who participated in high school sports and those who did not differ significantly in their attitudes about sexual violence and willingness to intervene as a bystander? Do these differ among types of rape myths and bystander intervention situations? (2) Within a group of athletes, are there significant differences by gender or type of sport (contact sport vs. non-contact?) To answer these questions, surveys were analyzed with a sample of recent high school graduates the summer before entering college (N = 3,588). Results indicate that there were only minor differences between those students who participated in high school varsity sports and those who did not. Students who participated in sports had greater acceptance of three out of five types of rape myths, and less willingness to intervene with perpetrators after an assault; however, the effect sizes were small. There were no significant differences for bystander efficacy. The interaction between sport and gender was significant, but contact sport was not. The findings suggest that there may be aspects of male athletic participation in sports that needs to be addressed, yet there also exists the potential for engaging athletes as leaders who can act as prosocial bystanders. © The Author(s) 2014.

Measurement of the bystander intervention model for bullying and sexual harassment.

PubMed

Nickerson, Amanda B; Aloe, Ariel M; Livingston, Jennifer A; Feeley, Thomas Hugh

2014-06-01

Although peer bystanders can exacerbate or prevent bullying and sexual harassment, research has been hindered by the absence of a validated assessment tool to measure the process and sequential steps of the bystander intervention model. A measure was developed based on the five steps of Latané and Darley's (1970) bystander intervention model applied to bullying and sexual harassment. Confirmatory factor analysis with a sample of 562 secondary school students confirmed the five-factor structure of the measure. Structural equation modeling revealed that all the steps were influenced by the previous step in the model, as the theory proposed. In addition, the bystander intervention measure was positively correlated with empathy, attitudes toward bullying and sexual harassment, and awareness of bullying and sexual harassment facts. This measure can be used for future research and to inform intervention efforts related to the process of bystander intervention for bullying and sexual harassment. Copyright © 2014 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

First aid: level of knowledge of relatives and bystanders in emergency situations.

PubMed

Tomruk, Onder; Soysal, Suna; Gunay, Turkan; Cimrin, Arif H

2007-01-01

Bystanders who are able to provide immediate first aid to patients who require emergency care can make a big difference in the outcome. Thus, first-aid training should be made available to as many people as possible. The aims of this study were to assess the level of first-aid knowledge among bystanders in emergency situations and to identify factors that affected this level of knowledge. At Dokuz Eylul University Emergency Service between February 1 and February 15, 2002, 318 bystanders were given a questionnaire. The first part of the questionnaire was concerned with demographic characteristics and factors that would affect first-aid knowledge level. The second part consisted of 16 multiple choice questions about first aid. Bystanders answered an average of 7.16+/-3.14 questions correctly. Bystanders who had graduated from a university, were health care personnel, had taken a first-aid course, had a first-aid certificate, or had a driver's license were considered to be more successful.

Adolescent bystanders' perspectives of aggression in the online versus school environments.

PubMed

Patterson, Lisa J; Allan, Alfred; Cross, Donna

2016-06-01

Researchers' understanding of bystanders' perspectives in the cyber-environment fails to take young people's perceptions into account and remains imperfect. Interventions encouraging adolescents to help targets of cyber-aggression are therefore typically based upon traditional school-based aggression research. Twenty-four in-depth interviews with Australian 13-16 year-olds revealed two themes that reflect how young bystanders perceive differences between aggression online and at school. The physical presence theme suggests that young bystanders struggle to determine online intentions in the absence of body language, leading to hesitancy in reactions and furthermore make it easier for them to ignore online transgressions and avoid becoming involved. The authority theme indicates young bystanders perceive that, compared to the school environment, the online environment lacks clearly established rules, authority figures and formal reporting mechanisms. These differences indicate that unique strategies should be developed to encourage young bystanders to intervene in cyber-aggression situations. Copyright © 2016 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Bystander Programs: Accommodating or Derailing Sexism?

PubMed Central

Reid, Adam; Dundes, Lauren

2017-01-01

Bystander programs implemented to meet federal requirements to reduce sexual assaults on college campuses in the United States must include primary prevention. Survey data (n = 280) and interview data (n = 20) presented in this paper explore students’ hypothetical and actual willingness to intervene as bystanders. Although most students surveyed (57%) claim they would be very likely to intervene, fewer than half would be very suspicious of someone leading away an intoxicated individual at a party (45% of women and 28% of men: p < 0.01). Interview data reveal how students perceive risk factors at college parties and what types of bystander measures they attempt, including “distractions”, a nonconfrontational tactic in which bystanders avoid more direct but socially risky interventions. Subsumed in many current bystander programs is an invisible element of valorizing harmony. Condoning bystanders’ unwillingness to directly confront seemingly predatory individuals could make change seem out of reach and could also embolden offenders whose behavior is observed and only temporarily thwarted. PMID:29299348

Extracellular signaling through the microenvironment: a hypothesis relating carcinogenesis, bystander effects, and genomic instability

NASA Technical Reports Server (NTRS)

Barcellos-Hoff, M. H.; Brooks, A. L.; Chatterjee, A. (Principal Investigator)

2001-01-01

Cell growth, differentiation and death are directed in large part by extracellular signaling through the interactions of cells with other cells and with the extracellular matrix; these interactions are in turn modulated by cytokines and growth factors, i.e. the microenvironment. Here we discuss the idea that extracellular signaling integrates multicellular damage responses that are important deterrents to the development of cancer through mechanisms that eliminate abnormal cells and inhibit neoplastic behavior. As an example, we discuss the action of transforming growth factor beta (TGFB1) as an extracellular sensor of damage. We propose that radiation-induced bystander effects and genomic instability are, respectively, positive and negative manifestations of this homeostatic process. Bystander effects exhibited predominantly after a low-dose or a nonhomogeneous radiation exposure are extracellular signaling pathways that modulate cellular repair and death programs. Persistent disruption of extracellular signaling after exposure to relatively high doses of ionizing radiation may lead to the accumulation of aberrant cells that are genomically unstable. Understanding radiation effects in terms of coordinated multicellular responses that affect decisions regarding the fate of a cell may necessitate re-evaluation of radiation dose and risk concepts and provide avenues for intervention.

Addressing bystander exposure to agricultural pesticides in life cycle impact assessment.

PubMed

Ryberg, Morten Walbech; Rosenbaum, Ralph K; Mosqueron, Luc; Fantke, Peter

2018-04-01

Residents living near agricultural fields may be exposed to pesticides drifting from the fields after application to different field crops. To address this currently missing exposure pathway in life cycle assessment (LCA), we developed a modeling framework for quantifying exposure of bystanders to pesticide spray drift from agricultural fields. Our framework consists of three parts addressing: (1) loss of pesticides from an agricultural field via spray drift; (2) environmental fate of pesticide in air outside of the treated field; and (3) exposure of bystanders to pesticides via inhalation. A comparison with measured data in a case study on pesticides applied to potato fields shows that our model gives good predictions of pesticide air concentrations. We compared our bystander exposure estimates with pathways currently included in LCA, namely aggregated inhalation and ingestion exposure mediated via the environment for the general population, and general population exposure via ingestion of pesticide residues in consumed food crops. The results show that exposure of bystanders is limited relative to total population exposure from ingestion of pesticide residues in crops, but that the exposure magnitude of individual bystanders can be substantially larger than the exposure of populations not living in the proximity to agricultural fields. Our framework for assessing bystander exposure to pesticide applications closes a relevant gap in the exposure assessment included in LCA for agricultural pesticides. This inclusion aids decision-making based on LCA as previously restricted knowledge about exposure of bystanders can now be taken into account. Copyright © 2018 Elsevier Ltd. All rights reserved.

Characteristics of adolescents who intervene to stop the risky and dangerous behavior of their friends.

PubMed

Buckley, Lisa; Chapman, Rebekah L

2016-03-01

Adolescents value protecting friends from harm and report that they do intervene as bystanders in friends' risky and dangerous behavior. Moreover intervention can be effective in reducing such behaviors. The Protection-Risk Framework was used to explain bystander intervention. There were 962 students from 13 Australian high schools (mean age at time 1=13.44 years) surveyed in their 9th grade and again 1-year later when students were in 10th grade. We found that protective factors of self-efficacy, support, prosocial models, social control, and ease of opportunity related to greater intervening behavior after 12-months. Among those who reported that they had intervened in a 3-month period, a cumulative measure of protective factors was associated with their reports of intervening. Risk factors were non-significant predictors after accounting for earlier, time 1, bystander intervening behavior and demographic factors. The findings highlight potential mechanisms to promote adolescents' looking out for their friends and provide an assessment over time of bystander behavior. The theory-guided inquiry into such behavior provides a foundation on which to better develop our understanding of benefits to adolescent friendship in the injury field. Copyright © 2016 Elsevier Ltd. All rights reserved.

Increased frequency of spontaneous neoplastic transformation in progeny of bystander cells from cultures exposed to densely ionizing radiation.

PubMed

Buonanno, Manuela; de Toledo, Sonia M; Azzam, Edouard I

2011-01-01

An increased risk of carcinogenesis caused by exposure to space radiation during prolonged space travel is a limiting factor for human space exploration. Typically, astronauts are exposed to low fluences of ionizing particles that target only a few cells in a tissue at any one time. The propagation of stressful effects from irradiated to neighboring bystander cells and their transmission to progeny cells would be of importance in estimates of the health risks of exposure to space radiation. With relevance to the risk of carcinogenesis, we investigated, in model C3H 10T½ mouse embryo fibroblasts (MEFs), modulation of the spontaneous frequency of neoplastic transformation in the progeny of bystander MEFs that had been in co-culture 10 population doublings earlier with MEFs exposed to moderate doses of densely ionizing iron ions (1 GeV/nucleon) or sparsely ionizing protons (1 GeV). An increase (P<0.05) in neoplastic transformation frequency, likely mediated by intercellular communication through gap junctions, was observed in the progeny of bystander cells that had been in co-culture with cells irradiated with iron ions, but not with protons.

Engaging Upstanders: Class-Wide Approach to Promoting Positive Bystander Behavior

ERIC Educational Resources Information Center

Wood, Laura; Smith, Jennifer; Varjas, Kris; Meyers, Joel

2016-01-01

Positive and supportive bystander behaviors have been associated with decreases in the frequency and negative impact of bullying. This article addresses the design, implementation, evaluation, and continuation of a classroom-based intervention that promotes positive bystander behaviors. The Engaging Upstanders curriculum was piloted with two…

Implications for Sexual Assault Prevention: College Students as Prosocial Bystanders

ERIC Educational Resources Information Center

Exner, Deinera; Cummings, Nina

2011-01-01

Prosocial bystander interventions are promising approaches to sexual assault prevention on college campuses. Objective: To assess bystander attitudes among undergraduate students at a northeastern university. Participants: A convenience sample of 188 students from 4 undergraduate classes was surveyed during regularly scheduled class sessions.…

Long-term biological effects induced by ionizing radiation--implications for dose mediated risk.

PubMed

Miron, S D; Astărăstoae, V

2014-01-01

Ionizing radiations are considered to be risk agents that are responsible for the effects on interaction with living matter. The occurring biological effects are due to various factors such as: dose, type of radiation, exposure time, type of biological tissue, health condition and the age of the person exposed. The mechanisms involved in the direct modifications of nuclear DNA and mitochondrial DNA are reviewed. Classical target theory of energy deposition in the nucleus that causes DNA damages, in particular DNA double-strand breaks and that explanation of the biological consequences of ionizing radiation exposure is a paradigm in radiobiology. Recent experimental evidences have demonstrated the existence of a molecular mechanism that explains the non-targeted effects of ionizing radiation exposure. Among these novel data, genomic instability and a variety of bystander effects are discussed here. Those bystander effects of ionizing radiation are fulfilled by cellular communication systems that give rise to non-targeted effects in the neighboring non irradiated cells. This paper provides also a commentary on the synergistic effects induced by the co-exposures to ionizing radiation and various physical agents such as electromagnetic fields and the co-exposures to ionizing radiation and chemical environmental contaminants such as metals. The biological effects of multiple stressors on genomic instability and bystander effects are also discussed. Moreover, a brief presentation of the methods used to characterize cyto- and genotoxic damages is offered.

A Pragmatic Study of Relational Identity in Bystander Intervention

ERIC Educational Resources Information Center

Huang, Xu

2018-01-01

Given that intervention has been relatively under-researched in pragmatics, this paper offers a linguistic-pragmatic examination of a case of bystander intervention, a notion which is generally known in social psychology. This study approaches the phenomenon of bystander intervention by analyzing discourse data transcribed from a video posted…

Bystander Approaches: Empowering Students to Model Ethical Sexual Behavior

ERIC Educational Resources Information Center

Lynch, Annette; Fleming, Wm. Michael

2005-01-01

Sexual violence on college campuses is well documented. Prevention education has emerged as an alternative to victim-- and perpetrator--oriented approaches used in the past. One sexual violence prevention education approach focuses on educating and empowering the bystander to become a point of ethical intervention. In this model, bystanders to…

Why Do Bystanders of Bullying Help or Not? A Multidimensional Model

ERIC Educational Resources Information Center

Pozzoli, Tiziana; Gini, Gianluca

2013-01-01

The authors employed Latane and Darley's model about bystanders' behavior to explain children's active defending and passive bystanding behavior in school bullying. The three central steps of the model were operationalized by measuring provictim attitudes, personal responsibility for intervention, and coping strategies. Moreover, the role of…

Rape Myth Beliefs and Bystander Attitudes among Incoming College Students

ERIC Educational Resources Information Center

McMahon, Sarah

2010-01-01

Objective: The bystander approach to rape prevention is gaining popularity on college campuses, although research is limited. This study explored bystander attitudes and their relationship with rape myths in a sample of college students. Participants: Surveys from 2,338 incoming undergraduate students at a large, northeastern university were…

Being a Positive Bystander: Male Antiviolence Allies’ Experiences of “Stepping Up”

PubMed Central

Casey, Erin A.; Ohler, Kristin

2014-01-01

As bystander approaches become increasingly prevalent elements of sexual and domestic violence prevention efforts, it is necessary to better understand the factors that support or impede individuals in taking positive action in the face of aggressive or disrespectful behavior from others. This study presents descriptive findings about the bystander experiences of 27 men who recently became involved in antiviolence against women work. More specifically, we describe the consistency with which respondents actively intervene in the speech or behavior of others, the strategies they use, and the factors they weigh as they deliberate taking action. Respondents report a complex and interrelated set of individual and contextual influences on their choices within bystander opportunities, which hold implications for both violence-specific models of bystander behavior and for prevention intervention development. PMID:21859757

L Particles Transmit Viral Proteins from Herpes Simplex Virus 1-Infected Mature Dendritic Cells to Uninfected Bystander Cells, Inducing CD83 Downmodulation.

PubMed

Heilingloh, Christiane S; Kummer, Mirko; Mühl-Zürbes, Petra; Drassner, Christina; Daniel, Christoph; Klewer, Monika; Steinkasserer, Alexander

2015-11-01

Mature dendritic cells (mDCs) are known as the most potent antigen-presenting cells (APCs) since they are also able to prime/induce naive T cells. Thus, mDCs play a pivotal role during the induction of antiviral immune responses. Remarkably, the cell surface molecule CD83, which was shown to have costimulatory properties, is targeted by herpes simplex virus 1 (HSV-1) for viral immune escape. Infection of mDCs with HSV-1 results in downmodulation of CD83, resulting in reduced T cell stimulation. In this study, we report that not only infected mDCs but also uninfected bystander cells in an infected culture show a significant CD83 reduction. We demonstrate that this effect is independent of phagocytosis and transmissible from infected to uninfected mDCs. The presence of specific viral proteins found in these uninfected bystander cells led to the hypothesis that viral proteins are transferred from infected to uninfected cells via L particles. These L particles are generated during lytic replication in parallel with full virions, called H particles. L particles contain viral proteins but lack the viral capsid and DNA. Therefore, these particles are not infectious but are able to transfer several viral proteins. Incubation of mDCs with L particles indeed reduced CD83 expression on uninfected bystander DCs, providing for the first time evidence that functional viral proteins are transmitted via L particles from infected mDCs to uninfected bystander cells, thereby inducing CD83 downmodulation. HSV-1 has evolved a number of strategies to evade the host's immune system. Among others, HSV-1 infection of mDCs results in an inhibited T cell activation caused by degradation of CD83. Interestingly, CD83 is lost not only from HSV-1-infected mDCs but also from uninfected bystander cells. The release of so-called L particles, which contain several viral proteins but lack capsid and DNA, during infection is a common phenomenon observed among several viruses, such as human cytomegalovirus (HCMV), Epstein-Barr virus, and HSV-1. However, the detailed function of these particles is poorly understood. Here, we provide for the first time evidence that functional viral proteins can be transferred to uninfected bystander mDCs via L particles, revealing important biological functions of these particles during lytic replication. Therefore, the transfer of viral proteins by L particles to modulate uninfected bystander cells may represent an additional strategy for viral immune escape. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Moral Disengagement among Bystanders to School Bullying

ERIC Educational Resources Information Center

Obermann, Marie-Louise

2011-01-01

This study examined the use of moral disengagement among children indirectly involved in bullying (bystanders). A sample of Danish adolescents (N = 660, M age 12.6 years) were divided into four groups depending on their bystander status: (a) outsiders, who did not experience bullying among their peers; (b) defenders, who were likely to help the…

A Solution to the Mysteries of Morality

ERIC Educational Resources Information Center

DeScioli, Peter; Kurzban, Robert

2013-01-01

We propose that moral condemnation functions to guide bystanders to choose the same side as other bystanders in disputes. Humans interact in dense social networks, and this poses a problem for bystanders when conflicts arise: which side, if any, to support. Choosing sides is a difficult strategic problem because the outcome of a conflict…

On Standby? A Comparison of Online and Offline Witnesses to Bullying and Their Bystander Behaviour

ERIC Educational Resources Information Center

Quirk, Roslynn; Campbell, Marilyn

2015-01-01

Given their ubiquitous presence as witnesses to school-yard bullying, the role of the "bystander" has been studied extensively. The prevalence and behaviour of bystanders to "cyberbullying," however, is less understood. In an anonymous, school-based questionnaire, 716 secondary school students from South-East Queensland…

Group vs. Individual Bystander Response to a Violent Assault: A Field Experiment.

ERIC Educational Resources Information Center

Harari, Herbert; And Others

Research studies on group versus individual bystander responses either have involved nonviolent emergencies or laboratory simulations. To investigate group versus individual bystander response to a violent assualt in a natural setting, 80 male college students (from an original pool of 393 white, male students) were observed either individually or…

Roles of Fatalism and Parental Support in the Relationship between Bullying Victimization and Bystander Behaviors

ERIC Educational Resources Information Center

Li, Yiqiong; Chen, Peter Y.; Chen, Fu-Li; Wu, Wen-Chi

2015-01-01

This article examines how past bullied victims engage two types of bystander behaviors (defender and outsider) when they witness bullying situations.We also investigate if fatalism mediates the relationship between past victimization and two bystander behaviors. Finally, we test if parental support moderates the relationship between fatalism and…

Examining Variation in Adolescent Bystanders' Responses to Bullying

ERIC Educational Resources Information Center

Waasdorp, Tracy Evian; Bradshaw, Catherine P.

2018-01-01

Latent class analysis was used to examine whether patterns of bystander responses varied as a function of both student- and school-level characteristics. Data from 18,863 high school students from 58 schools who "ever witnessed bullying" were used to identify five latent classes of bystander behavior. Three of the classes identified…

Sorority Women's and Fraternity Men's Rape Myth Acceptance and Bystander Intervention Attitudes

ERIC Educational Resources Information Center

Bannon, R. Sean; Brosi, Matthew W.; Foubert, John D.

2013-01-01

Sorority women and fraternity men are more likely than other students to be survivors and perpetrators of sexual assault, respectively. The present study examined sorority and fraternity members' rape myth acceptance, bystander efficacy, and bystander willingness to help in potential sexual assault situations. Sorority women were more rejecting of…

Social eavesdropping and the evolution of conditional cooperation and cheating strategies

PubMed Central

Earley, Ryan L.

2010-01-01

The response of bystanders to information available in their social environment can have a potent influence on the evolution of cooperation and signalling systems. In the presence of bystanders, individuals might be able to increase their payoff by exaggerating signals beyond their means (cheating) or investing to help others despite considerable costs. In doing so, animals can accrue immediate benefits by manipulating (or helping) individuals with whom they are currently interacting and delayed benefits by convincing bystanders that they are more fit or cooperative than perhaps is warranted. In this paper, I provide some illustrative examples of how bystanders could apply added positive selection pressure on both cooperative behaviour and dishonest signalling during courtship or conflict. I also discuss how the presence of bystanders might select for greater flexibility in behavioural strategies (e.g. conditional or condition dependence), which could maintain dishonesty at evolutionarily stable frequencies under some ecological conditions. By recognizing bystanders as a significant selection pressure, we might gain a more realistic approximation of what drives signalling and/or interaction dynamics in social animals. PMID:20679111

Chronic bystander infections and immunity to unrelated antigens

PubMed Central

Stelekati, Erietta; Wherry, E. John

2012-01-01

Chronic infections with persistent pathogens such as helminths, mycobacteria, Plasmodium and hepatitis viruses affect more than a third of the human population and are associated with increased susceptibility to other pathogens as well as reduced vaccine efficacy. Although these observations suggest an impact of chronic infections in modulating immunity to unrelated antigens, little is known regarding the underlying mechanisms. Here, we summarize evidence of the most prevalent infections affecting immunity to unrelated pathogens and vaccines, and discuss potential mechanisms of how different bystander chronic infections might impact immune responses. We suggest that bystander chronic infections affect different stages of host responses and may impact transmission of other pathogens, recognition and innate immune responses, priming and differentiation of adaptive effector responses, as well as the development and maintenance of immunological memory. Further understanding of the immunological effects of co-infection should provide opportunities to enhance vaccine efficacy and control infectious diseases. PMID:23084915

Designing, implementing, and evaluating a media campaign illustrating the bystander role.

PubMed

Potter, Sharyn J; Stapleton, Jane G; Moynihan, Mary M

2008-01-01

Recent research found that training men and women to understand the role of bystanders in situations where violence against women (VAW) is occurring may reduce the incidence of VAW (Moynihan & Banyard, 2004). Therefore a public awareness campaign to increase understanding of the prosocial role of bystanders in reducing VAW was developed and implemented. The current article discusses the role of media campaigns in addressing public health issues and describes the initial development, implementation, and evaluation of a media campaign focused on the bystander role in reducing the incidence of VAW. Conclusions and future directions of this exploratory project are discussed.

RCT Testing Bystander Effectiveness to Reduce Violence.

PubMed

Coker, Ann L; Bush, Heather M; Cook-Craig, Patricia G; DeGue, Sarah A; Clear, Emily R; Brancato, Candace J; Fisher, Bonnie S; Recktenwald, Eileen A

2017-05-01

Bystander-based programs have shown promise to reduce interpersonal violence at colleges, yet limited rigorous evaluations have addressed bystander intervention effectiveness in high schools. This study evaluated the Green Dot bystander intervention to reduce sexual violence and related forms of interpersonal violence in 26 high schools over 5 years. A cluster RCT was conducted. Kentucky high schools were randomized to intervention or control (wait list) conditions. Green Dot-trained educators conducted schoolwide presentations and recruited student popular opinion leaders to receive bystander training in intervention schools beginning in Year 1. The primary outcome was sexual violence perpetration, and related forms of interpersonal violence victimization and perpetration were also measured using anonymous student surveys collected at baseline and annually from 2010 to 2014. Because the school was the unit of analysis, violence measures were aggregated by school and year and school-level counts were provided. A total of 89,707 students completed surveys. The primary, as randomized, analyses conducted in 2014-2016 included linear mixed models and generalized estimating equations to examine the condition-time interaction on violence outcomes. Slopes of school-level totals of sexual violence perpetration (condition-time, p<0.001) and victimization (condition-time, p<0.001) were different over time. During Years 3-4, when Green Dot was fully implemented, the mean number of sexual violent events prevented by the intervention was 120 in Intervention Year 3 and 88 in Year 4. For Year 3, prevalence rate ratios for sexual violence perpetration in the intervention relative to control schools were 0.83 (95% CI=0.70, 0.99) in Year 3 and 0.79 (95% CI=0.67, 0.94) in Year 4. Similar patterns were observed for sexual violence victimization, sexual harassment, stalking, and dating violence perpetration and victimization. Implementation of Green Dot in Kentucky high schools significantly decreased not only sexual violence perpetration but also other forms of interpersonal violence perpetration and victimization. Copyright © 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

RCT Testing Bystander Effectiveness to Reduce Violence

PubMed Central

Coker, Ann L.; Bush, Heather M.; Cook-Craig, Patricia G.; DeGue, Sarah A.; Clear, Emily R.; Brancato, Candace J.; Fisher, Bonnie S.; Recktenwald, Eileen A.

2017-01-01

Introduction Bystander-based programs have shown promise to reduce interpersonal violence at colleges, yet limited rigorous evaluations have addressed bystander intervention effectiveness in high schools. This study evaluated the Green Dot bystander intervention to reduce sexual violence and related forms of interpersonal violence in 26 high schools over 5 years. Design A cluster RCT was conducted. Setting/participants Kentucky high schools were randomized to intervention or control (wait list) conditions. Intervention Green Dot–trained educators conducted schoolwide presentations and recruited student popular opinion leaders to receive bystander training in intervention schools beginning in Year 1. Main outcome measures The primary outcome was sexual violence perpetration, and related forms of interpersonal violence victimization and perpetration were also measured using anonymous student surveys collected at baseline and annually from 2010 to 2014. Because the school was the unit of analysis, violence measures were aggregated by school and year and school-level counts were provided. Results A total of 89,707 students completed surveys. The primary, as randomized, analyses conducted in 2014–2016 included linear mixed models and generalized estimating equations to examine the condition–time interaction on violence outcomes. Slopes of school-level totals of sexual violence perpetration (condition–time, p<0.001) and victimization (condition time, p<0.001) were different over time. During Years 3–4, when Green Dot was fully implemented, the mean number of sexual violent events prevented by the intervention was 120 in Intervention Year 3 and 88 in Year 4. For Year 3, prevalence rate ratios for sexual violence perpetration in the intervention relative to control schools were 0.83 (95% CI=0.70, 0.99) in Year 3 and 0.79 (95% CI=0.67, 0.94) in Year 4. Similar patterns were observed for sexual violence victimization, sexual harassment, stalking, and dating violence perpetration and victimization. Conclusions Implementation of Green Dot in Kentucky high schools significantly decreased not only sexual violence perpetration but also other forms of interpersonal violence perpetration and victimization. PMID:28279546

Preventing and Responding to Sexual Misconduct: Preliminary Efficacy of a Peer-Led Bystander Training Program for Preventing Sexual Misconduct and Reducing Heavy Drinking Among Collegiate Athletes.

PubMed

Morean, Meghan E; Darling, Nancy; Smit, Jessie; DeFeis, Jolie; Wergeles, Maya; Kurzer-Yashin, Dana; Custer, Kaitlyn

2018-06-01

Sexual misconduct occurs with disproportionate frequency on college campuses, and alcohol is involved in most sexual assaults. Importantly, collegiate athletes are at risk for both heavy drinking and sexual misconduct. Thus, the current study evaluated the efficacy of a novel, 2.5-hr, peer-facilitated, interactive, group-based bystander intervention program for student athletes that integrated information on sexual misconduct and risky drinking (Preventing and Responding to Sexual Misconduct [PRSM]). In all, 205 athletes completed 25-min surveys immediately before and after the training, and 76 (of 94 invited) completed a 3-month follow-up. Participating in the workshop was associated with significant increases in acknowledgment that sexual misconduct is a problem on campus, knowledge of where to get help if sexual misconduct occurs, knowledge about the college's procedures for addressing sexual misconduct, confidence that the college's procedures for addressing sexual misconduct are fair, bystander confidence, and engagement in a range of bystander activities. A significant decrease in rape myths also was observed. Participating in the workshop also produced changes in alcohol-related beliefs and behaviors. After participating in PRSM, athletes reported increased expectations that drinking alcohol can produce negative effects including aggression and acute intoxication. Participating in the workshop also was associated with significant reductions in drinking frequency, the total number of drinks consumed per month, the maximum drinks consumed in 24 hours, the frequency of binge-drinking episodes, and the experience of alcohol-related problems. In sum, the PRSM program evidenced preliminary efficacy as a program designed to increase prosocial bystander behavior and decrease high-risk drinking among collegiate athletes; changes in beliefs and behaviors consistent with reducing risk for sexual misconduct and problem drinking were observed after workshop participation. Future research should evaluate whether the PRSM program is effective for use with other high-risk populations like fraternity members or more diverse institutions of higher education including large universities.

The effect of basic life support education on laypersons' willingness in performing bystander hands only cardiopulmonary resuscitation.

PubMed

Cho, Gyu Chong; Sohn, You Dong; Kang, Ku Hyun; Lee, Won Woong; Lim, Kyung Soo; Kim, Won; Oh, Bum Jin; Choi, Dai Hai; Yeom, Seok Ran; Lim, Hoon

2010-06-01

Recently, hands only CPR (cardiopulmonary resuscitation) has been proposed as an alternative to standard CPR for bystanders. The present study was performed to identify the effect of basic life support (BLS) training on laypersons' willingness in performing standard CPR and hands only CPR. The participants for this study were non-medical personnel who applied for BLS training program that took place in 7 university hospitals in and around Korea for 6 months. Before and after BLS training, all the participants were given questionnaires for bystander CPR, and 890 respondents were included in the final analyses. Self-assessed confidence score for bystander CPR, using a visual analogue scale from 0 to 100, increased from 51.5+/-30.0 before BLS training to 87.0+/-13.7 after the training with statistical significance (p 0.001). Before the training, 19% of respondents reported willingness to perform standard CPR on a stranger, and 30.1% to perform hands only CPR. After the training, this increased to 56.7% of respondents reporting willingness to perform standard CPR, and 71.9%, hands only CPR, on strangers. Before and after BLS training, the odds ratio of willingness to perform hands only CPR versus standard CPR were 1.8 (95% CI 1.5-2.3) and 2.0 (95% CI 1.7-2.6) for a stranger, respectively. Most of the respondents, who reported they would decline to perform standard CPR, stated that fear of liability and fear of disease transmission were deciding factors after the BLS training. The BLS training increases laypersons' confidence and willingness to perform bystander CPR on a stranger. However, laypersons are more willing to perform hands only CPR rather than to perform standard CPR on a stranger regardless of the BLS training. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Non-targeted and delayed effects of exposure to ionizing radiation: II. Radiation-induced genomic instability and bystander effects in vivo, clastogenic factors and transgenerational effects

NASA Technical Reports Server (NTRS)

Morgan, William F.

2003-01-01

The goal of this review is to summarize the evidence for non-targeted and delayed effects of exposure to ionizing radiation in vivo. Currently, human health risks associated with radiation exposures are based primarily on the assumption that the detrimental effects of radiation occur in irradiated cells. Over the years a number of non-targeted effects of radiation exposure in vivo have been described that challenge this concept. These include radiation-induced genomic instability, bystander effects, clastogenic factors produced in plasma from irradiated individuals that can cause chromosomal damage when cultured with nonirradiated cells, and transgenerational effects of parental irradiation that can manifest in the progeny. These effects pose new challenges to evaluating the risk(s) associated with radiation exposure and understanding radiation-induced carcinogenesis.

Adult age differences in unconscious transference: source confusion or identity blending?

PubMed

Perfect, Timothy J; Harris, Lucy J

2003-06-01

Eyewitnesses are known often to falsely identify a familiar but innocent bystander when asked to pick out a perpetrator from a lineup. Such unconscious transference errors have been attributed to either identity confusions at encoding or source retrieval errors. Three experiments contrasted younger and older adults in their susceptibility to such misidentifications. Participants saw photographs of perpetrators, then a series of mug shots of innocent bystanders. A week later, they saw lineups containing bystanders (and others containing perpetrators in Experiment 3) and were asked whether any of the perpetrators were present. When younger faces were used as stimuli (Experiments 1 and 3), older adults showed higher rates of transference errors. When older faces were used as stimuli (Experiments 2 and 3), no such age effects in rates of unconscious transference were apparent. In addition, older adults in Experiment 3 showed an own-age bias effect for correct identification of targets. Unconscious transference errors were found to be due to both source retrieval errors and identity confusions, but age-related increases were found only in the latter.

Bystanders' responses to offline bullying and cyberbullying: The role of empathy and normative beliefs about aggression.

PubMed

Machackova, Hana; Pfetsch, Jan

2016-04-01

Cyberbullying often takes place with the virtual presence or knowledge of bystanders. While we have some evidence about the determinants of bystanders' responses to offline bullying, we lack empirical studies concerning the variables that influence bystanders' responses to cyberbullying. The current study examines bystanders' responses to offline bullying and cyberbullying incidents. Two types of responses were captured: support toward the victims and the reinforcement of bullies' actions. Using data from 321 German adolescents (ages 12-18; M = 14.99; 44% girls), the association between bystanders' responses and normative beliefs about verbal aggression and cyberaggression, and affective and cognitive empathy, were tested in a path model. Both types of normative beliefs positively predicted the reinforcement of bullies, and normative belief about verbal aggression also predicted support for the victims of offline bullying. Both types of empathy predicted support in offline bullying, but only affective empathy predicted support in cyberbullying. There was no link between affective or cognitive empathy to the reinforcement of bullies. Moreover, bystanders' tendencies to respond supportively to the victim or to reinforce the bully were rather consistent in both cyber- and offline bullying, but there was no link between support and reinforcement. The findings are discussed with regard to implications for prevention and intervention efforts. © 2016 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Identifying barriers to the provision of bystander cardiopulmonary resuscitation (CPR) in high-risk regions: a qualitative review of emergency calls.

PubMed

Case, Rosalind; Cartledge, Susie; Siedenburg, Josine; Smith, Karen; Straney, Lahn; Barger, Bill; Finn, Judith; Bray, Janet E

2018-06-01

Understanding regional variation in bystander cardiopulmonary resuscitation (CPR) is important to improving out-of-hospital cardiac arrest (OHCA) survival. In this study we aimed to identify barriers to providing bystander CPR in regions with low rates of bystander CPR and where OHCA was recognised in the emergency call. We retrospectively reviewed emergency calls for adults in regions of low bystander CPR in the Australian state of Victoria. Included calls were those where OHCA was identified during the call but no bystander CPR was given. A thematic content analysis was independently conducted by two investigators. Saturation of themes was reached after listening to 139 calls. Calls progressed to the point of compression instructions before EMS arrival in only 26 (18.7%) of cases. Three types of barriers were identified: procedural barriers (time lost due to language barriers and communication issues; telephone problems), CPR knowledge (skill deficits; perceived benefit) and personal factors (physical frailty or disability; patient position; emotional factors). A range of factors are associated with barriers to delivering bystander CPR even in the presence of dispatcher instructions -some of which are modifiable. To overcome these barriers in high-risk regions, targeted public education needs to provide information about what occurs in an emergency call, how to recognise an OHCA and to improve CPR knowledge and skills. Copyright © 2018. Published by Elsevier B.V.

Low-dose energetic protons induce adaptive and bystander effects that protect human cells against DNA damage caused by a subsequent exposure to energetic iron ions.

PubMed

Buonanno, Manuela; De Toledo, Sonia M; Howell, Roger W; Azzam, Edouard I

2015-05-01

During interplanetary missions, astronauts are exposed to mixed types of ionizing radiation. The low 'flux' of the high atomic number and high energy (HZE) radiations relative to the higher 'flux' of low linear energy transfer (LET) protons makes it highly probable that for any given cell in the body, proton events will precede any HZE event. Whereas progress has been made in our understanding of the biological effects of low-LET protons and high-LET HZE particles, the interplay between the biochemical processes modulated by these radiations is unclear. Here we show that exposure of normal human fibroblasts to a low mean absorbed dose of 20 cGy of 0.05 or 1-GeV protons (LET ∼ 1.25 or 0.2 keV/μm, respectively) protects the irradiated cells (P < 0.0001) against chromosomal damage induced by a subsequent exposure to a mean absorbed dose of 50 cGy from 1 GeV/u iron ions (LET ∼ 151 keV/μm). Surprisingly, unirradiated (i.e. bystander) cells with which the proton-irradiated cells were co-cultured were also significantly protected from the DNA-damaging effects of the challenge dose. The mitigating effect persisted for at least 24 h. These results highlight the interactions of biological effects due to direct cellular traversal by radiation with those due to bystander effects in cell populations exposed to mixed radiation fields. They show that protective adaptive responses can spread from cells targeted by low-LET space radiation to bystander cells in their vicinity. The findings are relevant to understanding the health hazards of space travel. © The Author 2015. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

Contributions of Personal and Situational Factors to Bystanders' Reactions to School Bullying

ERIC Educational Resources Information Center

Oh, Insoo; Hazler, Richard J.

2009-01-01

The intent of this study was to explore bystanders' personal and situational variables predicting their behavioural reactions to school bullying by investigating a sample of 298 college students who had witnessed bullying during middle or high school. Results indicated that the bystander personal variables, gender and past experience as a bully or…

What Would You Do? Strategies for Bystander Intervention to Prevent Sexual Violence by College Students

ERIC Educational Resources Information Center

McMahon, Sarah; Hoffman, Melanie Lowe; McMahon, Sheila M.; Zucker, Sharon; Koenick, Ruth Anne

2013-01-01

Bystander education is an increasingly utilized strategy for addressing sexual assault prevention and intervention on U.S. college campuses. Given the paramount importance of peers among college students, what types of pro-social bystander interventions do students themselves deem feasible in the campus context? Drawing on self-reports from…

Conceptualizing the Engaging Bystander Approach to Sexual Violence Prevention on College Campuses

ERIC Educational Resources Information Center

McMahon, Sarah; Postmus, Judy L.; Koenick, Ruth Anne

2011-01-01

Bystander intervention offers promise as a sexual violence prevention tool for student affairs administrators on college campuses, but the conceptualization and definition of the approach is in its infancy and needs further development. In an effort to emphasize the potential role of bystanders in the primary prevention of sexual violence, we put…

A Bully's Bystanders Are Never Innocent

ERIC Educational Resources Information Center

Coloroso, Barbara

2005-01-01

Though they play the least active role, bystanders are a critical element in bullying. With peers looking on and providing at least tacit support, the bully is no longer acting alone. The bystanders have become allies to the point of magnifying the supposed negative attributes of the target. If the bullying cycle is to be broken, the role of the…

Measuring Bystander Attitudes and Behavior to Prevent Sexual Violence

ERIC Educational Resources Information Center

McMahon, Sarah; Allen, Christopher T.; Postmus, Judy L.; McMahon, Sheila M.; Peterson, N. Andrew; Lowe Hoffman, Melanie

2014-01-01

Objective: The purpose of this study is to further investigate the factor structure and strength of the Bystander Attitude Scale-Revised and Bystander Behavior Scale-Revised (BAS-R and BBS-R). Participants: First-year students (N = 4,054) at a large public university in the Northeast completed a survey in 2010 as part of a larger longitudinal…

Using Social Self-Identification in Social Marketing Materials Aimed at Reducing Violence against Women on Campus

ERIC Educational Resources Information Center

Potter, Sharyn J.; Moynihan, Mary M.; Stapleton, Jane G.

2011-01-01

Bystander-focused in person sexual violence prevention programs provide an opportunity for skill development among bystanders and for widening the safety net for survivors. A social marketing campaign was designed modeling prosocial bystander behavior and using content familiar to target audience members by staging and casting scenes to look…

The impact of bystanding to workplace bullying on symptoms of depression among women and men in industry in Sweden: an empirical and theoretical longitudinal study.

PubMed

Emdad, R; Alipour, A; Hagberg, J; Jensen, I B

2013-08-01

Prospective studies on bystanding to workplace bullying and the health outcomes are scarce. To investigate the work environmental risk factors of depressive symptoms among bystanders to bullying in both women and men in four large industrial organizations in Sweden. The number of respondents at four large industrial enterprises with more than one year at the workplace at T1: n = 2,563 (Women: n = 342; Men: n = 2,227). Bystanders to bullying at T1: n = 305 (Women: n = 30; Men: n = 275). The total number of those with symptoms of depression at T2: Women: n = 30; Men: n = 161. Two thousand one hundred and seventy-seven employees answered the questionnaire on T1 and T2 with an 18-month interval. "To have depressive symptoms" was defined as not having depressive symptoms at T1 but having depressive symptoms at T2. The number of men who were bystanders to bullying was larger compared to women. However, the proportion of women who were bystanders to bullying and developed depressive symptoms 18 months later was higher in comparison with men (33.3 and 16.4 %, respectively). Further, "Being a bystander to bullying" 1.69 (1.13-2.53), "Rumors of changes in the workplace" 1.53 (1.10-2.14), "Reduced role clarity" 2.30 (1.21-4.32), "Lack of appreciation of being in the group" 1.76 (1.22-2.53) increased the risk of future symptoms of depression. "Job Strain" was not an adjusted risk factor for depression. Our results support previous findings that bystanding to workplace bullying is related to future depressive symptoms.

Neighborhood characteristics, bystander automated external defibrillator use, and patient outcomes in public out-of-hospital cardiac arrest.

PubMed

Andersen, Lars W; Holmberg, Mathias J; Granfeldt, Asger; Løfgren, Bo; Vellano, Kimberly; McNally, Bryan F; Siegerink, Bob; Kurth, Tobias; Donnino, Michael W

2018-05-01

Automated external defibrillators (AEDs) can be used by bystanders to provide rapid defibrillation for patients with out-of-hospital cardiac arrest (OHCA). Whether neighborhood characteristics are associated with AED use is unknown. Furthermore, the association between AED use and outcomes has not been well characterized for all (i.e. shockable and non-shockable) public OHCAs. We included public, non-911-responder witnessed OHCAs registered in the Cardiac Arrest Registry to Enhance Survival (CARES) between 2013 and 2016. The primary patient outcome was survival to hospital discharge with a favorable functional outcome. We first assessed the association between neighborhood characteristics and bystander AED use using logistic regression and then assessed the association between bystander AED use and patient outcomes in a propensity score matched cohort. 25,182 OHCAs were included. Several neighborhood characteristics, including the proportion of people living alone, the proportion of white people, and the proportion with a high-school degree or higher, were associated with bystander AED use. 5132 OHCAs were included in the propensity score-matched cohort. Bystander AED use was associated with an increased risk of a favorable functional outcome (35% vs. 25%, risk difference: 9.7% [95% confidence interval: 7.2%, 12.2%], risk ratio: 1.38 [95% confidence interval: 1.27, 1.50]). This was driven by increased favorable functional outcomes with AED use in patients with shockable rhythms (58% vs. 39%) but not in patients with non-shockable rhythms (10% vs. 10%). Specific neighborhood characteristics were associated with bystander AED use in OHCA. Bystander AED use was associated with an increase in favorable functional outcome. Copyright © 2018 Elsevier B.V. All rights reserved.

Analysis of bystander CPR quality during out-of-hospital cardiac arrest using data derived from automated external defibrillators.

PubMed

Fernando, Shannon M; Vaillancourt, Christian; Morrow, Stanley; Stiell, Ian G

2018-07-01

Little is known regarding the quality of cardiopulmonary resuscitation (CPR) performed by bystanders in out-of-hospital cardiac arrest (OHCA). We sought to determine quality of bystander CPR provided during OHCA using CPR quality data stored by Automated External Defibrillators (AEDs). We used the Resuscitation Outcomes Consortium database to identify OHCA cases of presumed cardiac etiology where an AED was utilized. We then matched AED data to each case identified. AED data was analyzed using manufacturer software in order to determine overall measures of bystander CPR quality, changes in bystander CPR quality over time, and adherence to existing 2010 Resuscitation Quality Guidelines. 100 cases of OHCA of presumed cardiac etiology involving bystander CPR and with corresponding AED data. Mean age was 62.3 years, and 75% were male. Bystanders demonstrated high-quality CPR over all minutes of resuscitation, with a chest compression fraction of 76%, a compression depth of 5.3 cm, and a compression rate of 111.2 compressions/min. Mean perishock pause was 26.8 s. Adherence rates to 2010 Resuscitation Guidelines for compression rate and depth were found to be 66% and 55%, respectively. CPR quality was lowest in the first minute, resulting from increased delay to rhythm analysis (mean 40.7 s). In cases involving shock delivery, latency from initiation of AED to shock delivery was 59.2 s. We found that bystanders perform high-quality CPR, with strong adherence rates to existing Resuscitation Guidelines. High-quality CPR is maintained over the first five minutes of resuscitation, but was lowest in the first minute. Copyright © 2018 Elsevier B.V. All rights reserved.

Lay Bystanders' Perspectives on What Facilitates Cardiopulmonary Resuscitation and Use of Automated External Defibrillators in Real Cardiac Arrests.

PubMed

Malta Hansen, Carolina; Rosenkranz, Simone Mørk; Folke, Fredrik; Zinckernagel, Line; Tjørnhøj-Thomsen, Tine; Torp-Pedersen, Christian; Sondergaard, Kathrine B; Nichol, Graham; Hulvej Rod, Morten

2017-03-13

Many patients who suffer an out-of-hospital cardiac arrest will fail to receive bystander intervention (cardiopulmonary resuscitation [CPR] or defibrillation) despite widespread CPR training and the dissemination of automated external defibrillators (AEDs). We sought to investigate what factors encourage lay bystanders to initiate CPR and AED use in a cohort of bystanders previously trained in CPR techniques who were present at an out-of-hospital cardiac arrest. One-hundred and twenty-eight semistructured qualitative interviews with CPR-trained lay bystanders to consecutive out-of-hospital cardiac arrest, where an AED was present were conducted (from January 2012 to April 2015, in Denmark). Purposive maximum variation sampling was used to establish the breadth of the bystander perspective. Twenty-six of the 128 interviews were chosen for further in-depth analyses, until data saturation. We used cross-sectional indexing (using software), and inductive in-depth thematic analyses, to identify those factors that facilitated CPR and AED use. In addition to prior hands-on CPR training, the following were described as facilitators: prior knowledge that intervention is crucial in improving survival, cannot cause substantial harm, and that the AED will provide guidance through CPR; prior hands-on training in AED use; during CPR performance, teamwork (ie, support), using the AED voice prompt and a ventilation mask, as well as demonstrating leadership and feeling a moral obligation to act. Several factors other than previous hands-on CPR training facilitate lay bystander instigation of CPR and AED use. The recognition and modification of these factors may increase lay bystander CPR rates and patient survival following an out-of-hospital cardiac arrest. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Comparison of Bystander Cardiopulmonary Resuscitation (BCPR) Performance in the Absence and Presence of Timing Devices for Coordinating Delivery of Ventilatory Breaths and Cardiac Compressions in a Model of Adult Cardiopulmonary Arrest

NASA Technical Reports Server (NTRS)

Hurst, Victor, IV; West, Sarah; Austin, Paul; Branson, Richard; Beck, George

2006-01-01

Astronaut crew medical officers (CMO) aboard the International Space Station (ISS) receive 40 hours of medical training during the 18 months preceding each mission. Part of this training ilncludes twoperson cardiopulmonary resuscitation (CPR) per training guidelines from the American Heart Association (AHA). Recent studies concluded that the use of metronomic tones improves the coordination of CPR by trained clinicians. Similar data for bystander or "trained lay people" (e.g. CMO) performance of CPR (BCPR) have been limited. The purpose of this study was to evailuate whether use of timing devices, such as audible metronomic tones, would improve BCPR perfomance by trained bystanders. Twenty pairs of bystanders trained in two-person BCPR performled BCPR for 4 minutes on a simulated cardiopulmonary arrest patient using three interventions: 1) BCPR with no timing devices, 2) BCPR plus metronomic tones for coordinating compression rate only, 3) BCPR with a timing device and metronome for coordinating ventilation and compression rates, respectively. Bystanders were evaluated on their ability to meet international and AHA CPR guidelines. Bystanders failed to provide the recommended number of breaths and number of compressions in the absence of a timing device and in the presence of audible metronomic tones for only coordinating compression rate. Bystanders using timing devices to coordinate both components of BCPR provided the reco number of breaths and were closer to providing the recommended number of compressions compared with the other interventions. Survey results indicated that bystanders preferred to use a metronome for delivery of compressions during BCPR. BCPR performance is improved by timing devices that coordinate both compressions and breaths.

Negative Bystander Behavior in Bullying Dynamics: Assessing the Impact of Social Capital Deprivation and Anti-social Capital.

PubMed

Evans, Caroline B R; Smokowski, Paul R

2017-02-01

Bystanders witness bullying, but are not directly involved as a bully or victim; however, they often engage in negative bystander behavior. This study examines how social capital deprivation and anti-social capital are associated with the likelihood of engaging in negative bystander behavior in a sample (N = 5752) of racially/ethnically diverse rural youth. Data were collected using an online, youth self-report; the current study uses cross sectional data. Following multiple imputation, a binary logistic regression with robust standard errors was run. Results partially supported the hypothesis and indicated that social capital deprivation in the form of peer pressure and verbal victimization and anti-social capital in the form of delinquent friends, bullying perpetration, verbal perpetration, and physical perpetration were significantly associated with an increased likelihood of engaging in negative bystander behavior. Findings highlight the importance of establishing sources of positive social support for disenfranchised youth.

Bystander Interventions for Sexual Assault and Dating Violence on College Campuses: Are We Putting Bystanders in Harm's Way?

ERIC Educational Resources Information Center

Witte, Tricia H.; Casper, Deborah M.; Hackman, Christine L.; Mulla, Mazheruddin M.

2017-01-01

Objective: The present study investigated the well-being of bystanders who witness and intervene in sexual assault and dating violence situations on campus. Participants: Participants were 321 young men and women from a large university in the southeastern United States. Methods: Participants completed a survey at the end of the Spring semester of…

A Longitudinal Study of the Associations between Moral Disengagement and Active Defending versus Passive Bystanding during Bullying Situations

ERIC Educational Resources Information Center

Doramajian, Caroline; Bukowski, William M.

2015-01-01

This study investigated the prospective association between moral disengagement and bystander behaviors in bullying situations, including both defending and passive bystanding. A diverse sample of Canadian school children (N = 130; 68 boys and 62 girls; mean age = 11.36 years) participated in a three-wave longitudinal study over a 4-month period.…

An Examination of the Social Influence Hypothesis of Bystander Intervention in Emergencies.

ERIC Educational Resources Information Center

Teger, Allan I.; Henderson James E.

Data is brought to bear on the social influence hypothesis, according to which the behavior of one bystander influences other bystanders by providing information leading to a definition of the situation. The study placed a subject in an emergency situation in which one of 3 confederates served as a model: (1) male peer; (2) female peer; or (3)…

Educating for Justice: Creating a Mission-Driven Model of Bystander Intervention to Address Sexual Violence at U.S. Catholic Colleges and Universities

ERIC Educational Resources Information Center

Galarneau, Joy; O'Neill, Shannon

2015-01-01

This article presents bystander intervention education as a best-practice approach to sexual violence prevention in college settings. It draws out a connection between mission-specific resources that can be used to advance the prevention agenda, while examining how bystander intervention education can deepen community engagement in collegiate…

Marketing defibrillation training programs and bystander intervention support.

PubMed

Sneath, Julie Z; Lacey, Russell

2009-01-01

This exploratory study identifies perceptions of and participation in resuscitation training programs, and bystanders' willingness to resuscitate cardiac arrest victims. While most of the study's participants greatly appreciate the importance of saving someone's life, many indicated that they did not feel comfortable assuming this role. The findings also demonstrate there is a relationship between type of victim and bystanders' willingness to intervene. Yet, bystander intervention discomfort can be overcome with cardiopulmonary resuscitation and defibrillation training, particularly when the victim is a coworker or stranger. Further implications of these findings are discussed and modifications to public access defibrillation (PAD) training programs' strategy and communications are proposed.

Bystander position taking in school bullying: the role of positive identity, self-efficacy, and self-determination.

PubMed

Tsang, Sandra K M; Hui, Eadaoin K P; Law, Bella C M

2011-01-01

School bullying has become an explicit, burgeoning problem challenging the healthy development of children and adolescents in Hong Kong. Many bullying prevention and intervention programs focus on victims and bullies, with bystanders treated as either nonexistent or irrelevant. This paper asserts that bystanders actually play pivotal roles in deciding whether the bullying process and dynamics are benign or adversarial. Bystanders' own abilities and characteristics often influence how they respond to victims and bullies. "P.A.T.H.S. to Adulthood: A Jockey Club Youth Enhancement Scheme" (P.A.T.H.S. = Positive Adolescent Training through Holistic Social Programmes) is an evidence-based positive youth development program which shows that primary intervention programs have constructive impacts on junior secondary school students' beliefs and behavior. This paper asserts that intrapsychic qualities, namely identity, self-efficacy, and self-determination, greatly influence how bystanders react in school bullying situations. The paper also explains how classroom-based educational programs based on the P.A.T.H.S. model have been designed to help junior secondary school students strengthen these characteristics, so that they can be constructive bystanders when they encounter school bullying.

Determine the yield of micronucleated cells in primary human fibroblasts exposed to focused soft X-rays.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kevin M. Prise

This project was a small part of a larger collaborative study headed by Dr Aloke Chatterjee, (Lawrence Berkeley National Laboratory) and including Drs Les Braby, John Ford (Texas A&M) and Kathy Held (MGH Boston), which was developing an integrated theoretical and experimental model of the radiation-induced bystander response. Our part of the study has been to determine the effectiveness of soft X-rays at inducing chromosomal damage under conditions of direct and bystander exposure. The aim was to compare this with the effectiveness of the low energy 60 kV electron microbeam available at Texas A&M. Previous studies have been performed withmore » primary human fibroblasts measuring micronuclei formation to determine the relative yields of direct versus bystander mediated micronuclei formation after cells were individually irradiated utilizing our novel focused soft X-ray microprobe, which is capable of producing localized submicron beams of carbon-K (278 eV) X-rays. Only a brief overview is given here as the study has been published in several papers. Our original hypothesis was to study yields of bystander-induced micronucleated cells in both wild-type and mutant fibroblast from mouse embryo fibroblasts. Difficulties with the level of background micronuclei in the MEFs prevented systematic studies of bystander responses in the laboratories involved in the collaboration. We then performed these studies with AG1522 primary human fibroblast cells using a siRNA approach developed by John Ford at Texas A&M to knock down DNA PKcs in the first instance. Our soft X-ray source has been in routine use for carbon-K X-rays and is now available with Aluminium-K (1.49 keV) and titanium-K (4.5 keV), although the dose-rate from titanium is still too low at present for most experiments, where large numbers of cells need to be exposed. A separately funded project developed a new soft X-ray microprobe which will give much greater flexibility for changing energies and giving high dose-rates for exposures (See DE-FG02-01ER63236). However, we performed pilot studies measuring bystander responses with titanium-K. To date we have performed studies with V79 cells measuring cell survival as an endpoint and are starting studies in our human fibroblasts to measure micronuclei yields. A significant bystander response is observed in the V79 cells under conditions where only a single cell within a population was irradiated either with carbon-K or titanium-K X-rays. Typically around 10% cell killing is observed under these conditions. These studies are now being extended to measure micronuclei yields in the AG1522 cells under direct and bystander conditions. Our work has suggested that the yield of micronuclei in fibroblasts exposed to soft X-rays may be reduced in comparison to conventional X-ray exposures (Prise et al., 2003). Although further studies are required to confirm this using a range of scoring times.« less

The non-targeted effects of radiation are perpetuated by exosomes.

PubMed

Al-Mayah, Ammar; Bright, Scott; Chapman, Kim; Irons, Sarah; Luo, Ping; Carter, David; Goodwin, Edwin; Kadhim, Munira

2015-02-01

Exosomes contain cargo material from endosomes, cytosol, plasma membrane and microRNA molecules, they are released by a number of non-cancer and cancer cells into both the extracellular microenvironment and body fluids such as blood plasma. Recently we demonstrated radiation-induced non-targeted effects [NTE: genomic instability (GI) and bystander effects (BE)] are partially mediated by exosomes, particularly the RNA content. However the mechanistic role of exosomes in NTE is yet to be fully understood. The present study used MCF7 cells to characterise the longevity of exosome-induced activity in the progeny of irradiated and unirradiated bystander cells. Exosomes extracted from conditioned media of irradiated and bystander progeny were added to unirradiated cells. Analysis was carried out at 1 and 20/24 population doublings following medium/exosome transfer for DNA/chromosomal damage. Results confirmed exosomes play a significant role in mediating NTE of ionising radiation (IR). This effect was remarkably persistent, observed >20 doublings post-irradiation in the progeny of bystander cells. Additionally, cell progeny undergoing a BE were themselves capable of inducing BE in other cells via exosomes they released. Furthermore we investigated the role of exosome cargo. Culture media from cells exposed to 2 Gy X-rays was subjected to ultracentrifugation and four inoculants prepared, (a) supernatants with exosomes removed, and pellets with (b) exosome proteins denatured, (c) RNA degraded, and (d) a combination of protein-RNA inactivation. These were added to separate populations of unirradiated cells. The BE was partially inhibited when either exosome protein or exosome RNA were inactivated separately, whilst combined RNA-protein inhibition significantly reduced or eliminated the BE. These results demonstrate that exosomes are associated with long-lived signalling of the NTE of IR. Both RNA and protein molecules of exosomes work in a synergistic manner to initiate NTE, spread these effects to naïve cells, and perpetuate GI in the affected cells. Copyright © 2015. Published by Elsevier B.V.

Bystander capability to activate speaker function for continuous dispatcher assisted CPR in case of suspected cardiac arrest.

PubMed

Steensberg, Alvilda T; Eriksen, Mette M; Andersen, Lars B; Hendriksen, Ole M; Larsen, Heinrich D; Laier, Gunnar H; Thougaard, Thomas

2017-06-01

The European Resuscitation Council Guidelines 2015 recommend bystanders to activate their mobile phone speaker function, if possible, in case of suspected cardiac arrest. This is to facilitate continuous dialogue with the dispatcher including (if required) cardiopulmonary resuscitation instructions. The aim of this study was to measure the bystander capability to activate speaker function in case of suspected cardiac arrest. In 87days, a systematic prospective registration of bystander capability to activate the speaker function, when cardiac arrest was suspected, was performed. For those asked, "can you activate your mobile phone's speaker function", audio recordings were examined and categorized into groups according to the bystanders capability to activate speaker function on their own initiative, without instructions, or with instructions from the emergency medical dispatcher. Time delay was measured, in seconds, for the bystanders without pre-activated speaker function. 42.0% (58) was able to activate the speaker function without instructions, 2.9% (4) with instructions, 18.1% (25) on own initiative and 37.0% (51) were unable to activate the speaker function. The median time to activate speaker function was 19s and 8s, with and without instructions, respectively. Dispatcher assisted cardiopulmonary resuscitation with activated speaker function, in cases of suspected cardiac arrest, allows for continuous dialogue between the emergency medical dispatcher and the bystander. In this study, we found a 63.0% success rate of activating the speaker function in such situations. Copyright © 2017 Elsevier B.V. All rights reserved.

Can implicit appraisal concepts produce emotion-specific effects? A focus on unfairness and anger.

PubMed

Tong, Eddie M W; Tan, Deborah H; Tan, Yan Lin

2013-06-01

This research examined whether the non-conscious activation of an implicit appraisal concept could affect responses associated with the corresponding emotion as predicted by appraisal theories. Explicit and implicit emotional responses were examined. We focused on implicit unfairness and its effect on anger. The results show that subliminal activation of implicit unfairness affected implicit anger responses (anger facial expression and latency responses to anger words) but not explicit anger feelings (i.e., reported anger). The non-conscious effect of implicit unfairness was specific to anger, as no effect on sadness, fear, and guilt was found. Copyright © 2013 Elsevier Inc. All rights reserved.

Are Chinese Students Willing to Learn and Perform Bystander Cardiopulmonary Resuscitation?

PubMed

Huang, Qiao; Hu, Cuihuan; Mao, Jing

2016-12-01

Immediate cardiopulmonary resuscitation (CPR) can improve survival rate from cardiac arrest and students are potentially important bystander CPR providers. Our aim was to investigate the willingness among Chinese students to learn and perform bystander CPR. Questionnaires were distributed to 1407 students. The survey investigated the willingness to learn and perform bystander CPR and the barriers to performing CPR on family members and strangers, assuming that students had mastered CPR. Only 14.6% of respondents reported having ever attended CPR training classes, however, 88.3% expressed their willingness to learn. The main characteristics of the students who were willing to learn were the following: they considered the development of the local emergency system excellent (odds ratio [OR] = 3.15); cardiovascular diseases were present within their family (OR = 2.74); and they had previously heard about CPR (OR = 2.43). Almost all respondents (94.6%) reported that they would conduct bystander CPR on family members, while only 59.7% of respondents would do it for strangers. A lack of confidence was the principal barrier to doing CPR for family members (78.4%) and the leading barrier to stranger CPR was the fear of legal liability if their lifesaving attempts failed (90.8%). The complicated process of performing CPR was also a major barrier in both scenarios. When there is a great desire to learn CPR, the rate and effect of training can be significantly improved by providing students with regular CPR training, especially compression-only CPR training. Training classes should focus on enhancing the participants' confidence. In addition, legislation by the government is needed to protect the rescuers. Copyright © 2016 Elsevier Inc. All rights reserved.

Translating sexual assault prevention from a college campus to a United States military installation: piloting the know-your-power bystander social marketing campaign.

PubMed

Potter, Sharyn J; Stapleton, Jane G

2012-05-01

One population that shares both similar and different characteristics with traditional college-age students is the U.S. Military. Similarities include a high concentration of 18- to 26-year-olds dealing with new found independence, peer pressure, and the presence of social norms that support violence and hypermasculinity. Sexual violence is a major public health problem in the United States, and because of the similarities in the age group of college and military populations, the problems regarding sexual violence in both constituencies have been well-documented. In the current pilot study we seek to add to both current knowledge about and promising practices of translating prevention strategies from one target audience to another. We describe how we translated, administered, and evaluated a bystander intervention social marketing campaign focused on sexual assault prevention that had been found to significantly affect attitude change on a college campus for a U.S. Army installation in Europe. In addition to demonstrating the process of translating prevention strategies across target audiences, findings from this pilot study contribute to the evaluation data on the effectiveness of sexual violence prevention strategies implemented with members of the U.S. Military. From our analysis, we see that research participants indicate that the degree to which the images resonate with them and the familiarity of the context (i.e., social self-identification) significantly effect the participants' personal responsibility for reducing sexual assault, confidence in acting as a bystander, and reported engagement as a bystander.

Modulation of oxidative phosphorylation (OXPHOS) by radiation- induced biophotons.

PubMed

Le, Michelle; McNeill, Fiona E; Seymour, Colin B; Rusin, Andrej; Diamond, Kevin; Rainbow, Andrew J; Murphy, James; Mothersill, Carmel E

2018-05-01

Radiation-induced biophotons are an electromagnetic form of bystander signalling. In human cells, biophoton signalling is capable of eliciting effects in non-irradiated bystander cells. However, the mechanisms by which the biophotons interact and act upon the bystander cells are not clearly understood. Mitochondrial energy production and ROS are known to be involved but the precise interactions are not known. To address this question, we have investigated the effect of biophoton emission upon the function of the complexes of oxidative phosphorylation (OXPHOS). The exposure of bystander HCT116 p53 +/+ cells to biophoton signals emitted from β-irradiated HCT116 p53 +/+ cells induced significant modifications in the activity of Complex I (NADH dehydrogenase or NADH:ubiquinone oxidoreductase) such that the activity was severely diminished compared to non-irradiated controls. The enzymatic assay showed that the efficiency of NADH oxidation to NAD+ was severely compromised. It is suspected that this impairment may be linked to the photoabsorption of biophotons in the blue wavelength range (492-455 nm). The photobiomodulation to Complex I was suspected to contribute greatly to the inefficiency of ATP synthase function since it resulted in a lower quantity of H + ions to be available for use in the process of chemiosmosis. Other reactions of the ETC were not significantly impacted. Overall, these results provide evidence for a link between biophoton emission and biomodulation of the mitochondrial ATP synthesis process. However, there are many aspects of biological modulation by radiation-induced biophotons which will require further elucidation. Copyright © 2018 Elsevier Inc. All rights reserved.

Challenges of Bystander Intervention in Male-Dominated Professional Sport: Lessons From the Australian Football League.

PubMed

Corboz, Julienne; Flood, Michael; Dyson, Sue

2016-03-01

Programs aimed at preventing violence against women have increasingly adopted bystander approaches, yet large gaps remain in our knowledge about what drives bystanders to act or not, particularly in settings where there is an increased risk of violence against women occurring. This article contributes to this gap by examining data from research with professional male athletes from the Australian Football League. Drawing from a mixed methods approach, including a survey and interviews with football players, we outline some of the challenges to bystander intervention faced by professional athletes and discuss some of the possible similarities and differences between these and other groups of men. © The Author(s) 2015.

Predictors of Sexual Assault-Specific Prosocial Bystander Behavior and Intentions: A Prospective Analysis.

PubMed

Austin, Megan J Murphy; Dardis, Christina M; Wilson, Milo S; Gidycz, Christine A; Berkowitz, Alan D

2016-01-01

This study prospectively examined the impact of men's own attitudes and behaviors and perceptions of peer attitudes and behaviors on intentions and engagement in prosocial bystander behavior. Undergraduate men completed surveys at baseline and 4- and 7-month follow-ups. Men's perceptions of peer attitudes and behaviors and their own attitudes and behaviors were both important predictors of intentions. However, men's own attitudes and behaviors appeared to be more robustly predictive of behavior. Intentions to engage in bystander behavior were not predictive of behavior. Results support two specific areas of bystander intervention programming addressing misperceptions of social norms and personal attitudes and behaviors. © The Author(s) 2015.

Social Capital and Bystander Behavior in Bullying: Internalizing Problems as a Barrier to Prosocial Intervention.

PubMed

Jenkins, Lyndsay N; Fredrick, Stephanie Secord

2017-04-01

Theory and research suggests that individuals with greater social capital (i.e., resources and benefits gained from relationships, experiences, and social interactions) may be more likely to be active, prosocial bystanders in bullying situations. Therefore, the goal of the current study was to examine the association of social capital (social support and social skills) with prosocial bystander behavior, and the role of internalizing problems as a potential barrier to this relation among 299 students (45.8% girls, 95% White) in sixth, seventh, and eighth grades. Results indicate a positive relation between social capital and prosocial bystander behavior. In addition, internalizing problems were a significant risk factor that may hinder youth-particularly girls-from engaging in defending behavior. Prosocial bystanders are an essential component to prevent and reduce bullying and further research is needed to better understand how to foster prosocial behavior in bullying situations, perhaps by utilizing social capital, related to school bullying.

Radiation induced COX-2 expression and mutagenesis at non-targeted lung tissues of gpt delta transgenic mice

PubMed Central

Chai, Y; Calaf, G M; Zhou, H; Ghandhi, S A; Elliston, C D; Wen, G; Nohmi, T; Amundson, S A; Hei, T K

2013-01-01

Background: Although radiation-induced bystander effects have been confirmed using a variety of endpoints, the mechanism(s) underlying these effects are not well understood, especially for in vivo study. Methods: A 1-cm2 area (1 cm × 1 cm) in the lower abdominal region of gpt delta transgenic mice was irradiated with 5 Gy of 300 keV X-rays, and changes in out-of-field lung and liver were observed. Results: Compared with sham-treated controls, the Spi− mutation frequency increased 2.4-fold in non-targeted lung tissues at 24 h after partial body irradiation (PBIR). Consistent with dramatic Cyclooxygenase 2 (COX-2) induction in the non-targeted bronchial epithelial cells, increasing levels of prostaglandin, together with 8-hydroxydeoxyguanosine, in the out-of-field lung tissues were observed after PBIR. In addition, DNA double-strand breaks and apoptosis were induced in bystander lung tissues after PBIR. Conclusion: The PBIR induces DNA damage and mutagenesis in non-targeted lung tissues, especially in bronchial epithelial cells, and COX-2 has an essential role in bystander mutagenesis. PMID:23321513

Quantifying the bystander-effect of 2.5G mobile telephones on the speech perception of digital hearing aid users.

PubMed

Vlastarakos, P V; Nikolopoulos, T P; Manolopoulos, L; Stamou, A; Halkiotis, K K; Ferekidis, E; Georgiou, E

2012-01-01

To quantify the bystander-effect of 2.5G mobile telephones (2.5G-MTs) on the speech perception of digital hearing-aid (dHA) users. Differences in the susceptibility of behind-the-ear (BTE) compared to in-to-the-ear (ITE) dHAs were also assessed. Prospective-comparative study conducted at a tertiary referral centre (ENT Department) and a HA-fitting laboratory. Key-word recognition scores from open-sentence lists were calculated. Power-analysis determined that a minimum of 60 subjects with SNHL (30 in each group), using either BTE or ITE dHAs, were required for reliable study outcomes. Sixty-four adults were tested with a functioning 2.5G-MT at almost physical contact with their ear; thirty subjects used BTE and 34 ITE dHAs. Aided word recognition score differences between studied groups and within each group, while a 2.5G-MT was activated. Cut-off inclusion criterion regarding baseline aided word recognition score was 75%. Baseline aided word recognition scores for ITE dHAs were better compared to BTE ones (p < 0.01). Following the 2.5G-MT activation, this difference disappeared. No statistically significant difference in word recognition was observed between the examined groups, or within the BTE group, from the bystander-effect of the 2.5G-MT. ITE dHAs proved more susceptible to electromagnetic interference (p < 0.05). The bystander-effect of 2.5G-MTs on the speech perception of dHA users is either minimal, or not significant. The observed compatibility has a positive impact on the lives of millions of people worldwide. The long-standing theory of more interference in BTE compared to ITE HAs is not confirmed by the results of the present study. EBM level of evidence: 2c.

Association between bystander cardiopulmonary resuscitation and redeemed prescriptions for antidepressants and anxiolytics in out-of-hospital cardiac arrest survivors.

PubMed

Bundgaard, Kristian; Hansen, Steen M; Mortensen, Rikke Nørmark; Wissenberg, Mads; Hansen, Malta; Lippert, Freddy; Gislason, Gunnar; Køber, Lars; Nielsen, Jimmi; Torp-Pedersen, Christian; Rasmussen, Bodil Steen; Kragholm, Kristian

2017-06-01

This study aimed to examine rates of redeemed prescriptions of antidepressants and anxiolytics, used as markers for cerebral dysfunction in out-of-hospital cardiac arrest (OHCA) survivors, and examine the association between bystander CPR and these psychoactive drugs. We included all 30-day survivors of OHCA in Denmark between 2001 and 2011, who had not redeemed prescriptions for antidepressants or anxiolytics in the last six months prior to OHCA. Main outcome measures were redeemed prescriptions of antidepressants and anxiolytics within one year after OHCA. Among 2,001 30-day survivors, 174 (8.6% died and 12.0% redeemed a first prescription for an antidepressant and 8.2% for an anxiolytic drug within one year after arrest. The corresponding frequencies for redeemed prescribed drugs among age- and sex-matched population controls were 7.5% and 5.2%, respectively. Among survivors who received bystander CPR, prescriptions for antidepressants and anxiolytics were redeemed in 11.1% [95% CI 9.2-13.3%] and 6.3% [95% CI 4.9-8.0%] of the cases, respectively, versus 17.2% [95% CI 13.9-21.1%] and 13.4% [95% CI 10.5-17.0%], respectively, among patients who had not received bystander CPR. Adjusted for age, sex, year of arrest, comorbidity, witnessed status and socioeconomic status, bystander CPR was associated with significant reductions in redeemed prescriptions for antidepressants, Hazard Ratio (HR) 0.71 [95% CI 0.52-0.98], P=0.031; and anxiolytics, HR 0.55 [95% CI 0.38-0.81], P=0.002. Relative to no bystander CPR, redeemed prescriptions for antidepressants and anxiolytics were significantly lower among 30-day survivors of OHCA who received bystander CPR, suggesting a cerebral dysfunction-lowering potential of bystander CPR. Copyright © 2017 Elsevier B.V. All rights reserved.

Senior citizens as rescuers: Is reduced knowledge the reason for omitted lay-resuscitation-attempts? Results from a representative survey with 2004 interviews.

PubMed

Brinkrolf, Peter; Bohn, Andreas; Lukas, Roman-Patrik; Heyse, Marko; Dierschke, Thomas; Van Aken, Hugo Karel; Hahnenkamp, Klaus

2017-01-01

Resuscitation (CPR) provided by a bystander prior to the arrival of the emergency services is a beneficial factor for surviving a cardiac arrest (CA). Our registry-based data show, that older patients receive bystander-CPR less frequently. Little is known on possible reasons for this finding. We sought to investigate the hypothesis that awareness of CPR measures is lower in older laypersons being a possible reason for less CPR-attempts in senior citizens. 1206 datasets on bystander resuscitations actually carried out were analyzed for age-dependent differences. Subsequently, we investigated whether the knowledge required carrying out bystander-CPR and the self-confidence to do so differ between younger and older citizens using computer-assisted telephone interviewing. 2004 interviews were performed and statistically analyzed. A lower level of knowledge to carry out bystander-CPR was seen in older individuals. For example, 82.4% of interviewees under 65 years of age, knew the correct emergency number. In this group, 66.6% named CPR as the relevant procedure in CA. Among older individuals these responses were only given by 75.1% and 49.5% (V = 0.082; P < 0.001 and V = 0.0157; P < 0.001). Additionally, a difference concerning participants' confidence in their own abilities was detectable. 58.0% of the persons younger than 65 years were confident that they would detect a CA in comparison to 44.6% of the participants older than 65 years (V = 0.120; P < 0.001). Similarly, 62.7% of the interviewees younger than 65 were certain to know what to do during CPR compared to 51.3% of the other group (V = 0.103; P < 0.001). Lower levels of older bystanders' knowledge and self-confidence might provide an explanation for why older patients receive bystander-CPR less frequently. Further investigation is necessary to identify causal connections and optimum ways to empower bystander resuscitation.

Senior citizens as rescuers: Is reduced knowledge the reason for omitted lay-resuscitation-attempts? Results from a representative survey with 2004 interviews

PubMed Central

Lukas, Roman-Patrik; Heyse, Marko; Dierschke, Thomas; Van Aken, Hugo Karel; Hahnenkamp, Klaus

2017-01-01

Objective Resuscitation (CPR) provided by a bystander prior to the arrival of the emergency services is a beneficial factor for surviving a cardiac arrest (CA). Our registry-based data show, that older patients receive bystander-CPR less frequently. Little is known on possible reasons for this finding. We sought to investigate the hypothesis that awareness of CPR measures is lower in older laypersons being a possible reason for less CPR-attempts in senior citizens. Methods 1206 datasets on bystander resuscitations actually carried out were analyzed for age-dependent differences. Subsequently, we investigated whether the knowledge required carrying out bystander-CPR and the self-confidence to do so differ between younger and older citizens using computer-assisted telephone interviewing. 2004 interviews were performed and statistically analyzed. Results A lower level of knowledge to carry out bystander-CPR was seen in older individuals. For example, 82.4% of interviewees under 65 years of age, knew the correct emergency number. In this group, 66.6% named CPR as the relevant procedure in CA. Among older individuals these responses were only given by 75.1% and 49.5% (V = 0.082; P < 0.001 and V = 0.0157; P < 0.001). Additionally, a difference concerning participants’ confidence in their own abilities was detectable. 58.0% of the persons younger than 65 years were confident that they would detect a CA in comparison to 44.6% of the participants older than 65 years (V = 0.120; P < 0.001). Similarly, 62.7% of the interviewees younger than 65 were certain to know what to do during CPR compared to 51.3% of the other group (V = 0.103; P < 0.001). Conclusions Lower levels of older bystanders' knowledge and self-confidence might provide an explanation for why older patients receive bystander-CPR less frequently. Further investigation is necessary to identify causal connections and optimum ways to empower bystander resuscitation. PMID:28604793

Association of initial rhythm with neurologically favorable survival in non-shockable out-of-hospital cardiac arrest without a bystander witness or bystander cardiopulmonary resuscitation.

PubMed

Fukuda, Tatsuma; Ohashi-Fukuda, Naoko; Matsubara, Takehiro; Doi, Kent; Kitsuta, Yoichi; Nakajima, Susumu; Yahagi, Naoki

2016-05-01

Out-of-hospital cardiac arrest (OHCA) has a predominantly non-shockable rhythm. Non-shockable rhythm, and the absence of a bystander witness or bystander cardiopulmonary resuscitation (CPR) are associated with poor outcomes. However, the association between the type of non-shockable rhythm and outcomes is not well known. To examine the association between the initial rhythm and neurologically favorable outcomes after non-shockable OHCA without a bystander witness or bystander CPR. In a nationwide, population-based, cohort study, we analyzed 213,984 adult OHCA patients with a non-shockable rhythm who had neither a bystander witness nor bystander CPR. They were identified through the Japanese national OHCA registry data from January 1, 2005 to December 31, 2010. The primary outcome was neurologically favorable survival. Among 213,984 patients, the initial rhythm was Pulseless Electrical Activity (PEA) in 31,179 patients (14.6%) and Asystole in 182,805 patients (85.4%). The neurological outcome was more favorable in PEA than in Asystole (1.4% vs. 0.2%, p<0.0001). After adjusting for age, sex, etiology of arrest, epinephrine administration, advanced airway management, time from call to contact with patient, and calendar year, PEA was associated with an increased neurologically favorable survival rate (odds ratio 7.86; 95% confidence interval 6.81-9.07). In subgroup analysis stratified by age group (18-64, 65-84, or ≥85years), the neurologically favorable survival rate was ≥1% in PEA, even for patients aged ≥85years, but <1% in Asystole among all age groups. PEA and Asystole should not be considered to be identical to non-shockable rhythm, but rather should be clearly distinguished from each other from the perspective of quantitative medical futility. Copyright © 2016 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

Recommendations in dispatcher-assisted bystander resuscitation from emergency call center.

PubMed

García del Águila, J; López-Messa, J; Rosell-Ortiz, F; de Elías Hernández, R; Martínez del Valle, M; Sánchez-Santos, L; López-Herce, J; Cerdà-Vila, M; Roza-Alonso, C L; Bernardez-Otero, M

2015-01-01

Dispatch-assisted bystander cardiopulmonary resuscitation in out-of-hospital cardiac arrest has been shown as an effective measure to improve the survival of this process. The development of a unified protocol for all dispatch centers of the different emergency medical services can be a first step towards this goal in our environment. The process of developing a recommendations document and the realization of posters of dispatch-assisted cardiopulmonary resuscitation, agreed by different actors and promoted by the Spanish Resuscitation Council, is presented. Copyright © 2015 Elsevier España, S.L.U. and SEMICYUC. All rights reserved.

Changes in vocal parameters with social context in humpback whales: considering the effect of bystanders.

PubMed

Dunlop, Rebecca A

Many theories and communication models developed from terrestrial studies focus on a simple dyadic exchange between a sender and receiver. During social interactions, the "frequency code" hypothesis suggests that frequency characteristics of vocal signals can simultaneously encode for static signaler attributes (size or sex) and dynamic information, such as motivation or emotional state. However, the additional presence of a bystander may result in a change of signaling behavior if the costs and benefits associated with the presence of this bystander are different from that of a simple dyad. In this study, two common humpback whale social calls ("wops" and "grumbles") were tested for differences related to group social behavior and the presence of bystanders. "Wop" parameters were stable with group social behavior, but were emitted at lower (14 dB) levels in the presence of a nearby singing whale compared to when a singing whale was not in the area. "Grumbles" were emitted at lower (30-39 Hz) fundamental frequencies in affiliative compared to non-affiliative groups and, in the presence of a nearby singing whale, were also emitted at lower (14 dB) levels. Vocal rates did not significantly change. The results suggest that, in humpbacks, the frequency in certain sound types relates to the social behavior of the vocalizing group, implying a frequency code system. The presence of a nearby audible bystander (a singing whale) had no effect on this frequency code, but by reducing their acoustic level, the signal-to-noise ratio at the singer would have been below 0, making it difficult for the singer to audibly detect the group. The frequency, duration, and amplitude parameters of humpback whale social vocalizations were tested between different social contexts: group social behavior (affiliating versus non-affiliating), the presence of a nearby singing whale, and the presence of a nearby non-singing group. "Grumbles" (commonly heard low-frequency unmodulated sounds) frequencies were lower in affiliating groups compared to non-affiliating groups, suggesting a change in group motivation (such as levels of aggression). "Wop" (another common sound type) structure (frequency and duration) was similar in affiliating and non-affiliating groups. In the presence of an audible bystander (a singing whale), both sound types were emitted at similar rates, but much lower amplitudes (14 dB), vastly reducing the detectability of these sounds by the singer. This suggests that these groups were acoustically avoiding the singing whale. They did not, however, acoustically respond to the presence of a nearby non-singing group.

Effects of brief mindful acceptance induction on implicit dysfunctional attitudes and concordance between implicit and explicit dysfunctional attitudes.

PubMed

Keng, Shian-Ling; Seah, Stanley T H; Tong, Eddie M W; Smoski, Moria

2016-08-01

Mindfulness-based interventions have been shown to be effective in alleviating depressive symptoms. While much work has examined the effects of mindfulness training on subjective symptoms and experiences, and less is known regarding whether mindfulness training may alter relatively uncontrollable cognitive processes associated with depressed mood, particularly implicit dysfunctional attitudes. The present study examined the effects of a brief mindful acceptance induction on implicit dysfunctional attitudes and degree of concordance between implicit and explicit dysfunctional attitudes in the context of sad mood. A total of 79 adult participants with elevated depressive symptoms underwent an autobiographical mood induction procedure before being randomly assigned to mindful acceptance or thought wandering inductions. Results showed that the effect of mindful acceptance on implicit dysfunctional attitude was significantly moderated by trait mindfulness. Participants high on trait mindfulness demonstrated significant improvements in implicit dysfunctional attitudes following the mindful acceptance induction. Those low on trait mindfulness demonstrated significantly worse implicit dysfunctional attitudes following the induction. Significantly greater levels of concordance between implicit and explicit dysfunctional attitudes were observed in the mindful acceptance condition versus the thought wandering condition. The findings highlight changes in implicit dysfunctional attitudes and improvements in self-concordance as two potential mechanisms underlying the effects of mindfulness-based interventions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Recognising out-of-hospital cardiac arrest during emergency calls increases bystander cardiopulmonary resuscitation and survival.

PubMed

Viereck, Søren; Møller, Thea Palsgaard; Ersbøll, Annette Kjær; Bækgaard, Josefine Stokholm; Claesson, Andreas; Hollenberg, Jacob; Folke, Fredrik; Lippert, Freddy K

2017-06-01

Initiation of early bystander cardiopulmonary resuscitation (CPR) depends on bystanders' or medical dispatchers' recognition of out-of-hospital cardiac arrest (OHCA). The primary aim of our study was to investigate if OHCA recognition during the emergency call was associated with bystander CPR, return of spontaneous circulation (ROSC), and 30-day survival. Our secondary aim was to identify patient-, setting-, and dispatcher-related predictors of OHCA recognition. We performed an observational study of all OHCA patients' emergency calls in the Capital Region of Denmark from 01/01/2013-31/12/2013. OHCAs were collected from the Danish Cardiac Arrest Registry and the Mobile Critical Care Unit database. Emergency call recordings were identified and evaluated. Multivariable logistic regression analyses were applied to all OHCAs and witnessed OHCAs only to analyse the association between OHCA recognition and bystander CPR, ROSC, and 30-day survival. Univariable logistic regression analyses were applied to identify predictors of OHCA recognition. We included 779 emergency calls in the analyses. During the emergency calls, 70.1% (n=534) of OHCAs were recognised; OHCA recognition was positively associated with bystander CPR (odds ratio [OR]=7.84, 95% confidence interval [CI]: 5.10-12.05) in all OHCAs; and ROSC (OR=1.86, 95% CI: 1.13-3.06) and 30-day survival (OR=2.80, 95% CI: 1.58-4.96) in witnessed OHCA. Predictors of OHCA recognition were addressing breathing (OR=1.76, 95% CI: 1.17-2.66) and callers located by the patient's side (OR=2.16, 95% CI: 1.46-3.19). Recognition of OHCA during emergency calls was positively associated with the provision of bystander CPR, ROSC, and 30-day survival in witnessed OHCA. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

"Please. Don't. Die.": A Grounded Theory Study of Bystander Cardiopulmonary Resuscitation.

PubMed

Mausz, Justin; Snobelen, Paul; Tavares, Walter

2018-02-01

Bystander cardiopulmonary resuscitation (CPR) is an important determinant of survival from out-of-hospital cardiac arrest (OHCA), yet rates of bystander CPR are highly variable. In an effort to promote bystander CPR, the procedure has been streamlined, and ultrashort teaching modalities have been introduced. CPR has been increasingly reconceptualized as simple, safe, and easy to perform; however, current methods of CPR instruction may not adequately prepare lay rescuers for the various logistical, conceptual, and emotional challenges of resuscitating a victim of cardiac arrest. We adopted a constructivist grounded theory methodology to qualitatively explore bystander CPR and invited lay rescuers who had recently (ie, within 1 week) intervened in an OHCA to participate in semistructured interviews and focus groups. We used constant comparative analysis until theoretical saturation to derive a midrange explanatory theory of bystander CPR. We constructed a 3-stage theoretical model describing a common experiential process for lay rescuer intervention in OHCA: Being called to act is disturbing, causing panic, shock, and disbelief that must ultimately be overcome. Taking action to save the victim is complicated by several misconceptions about cardiac arrest, where victims are mistakenly believed to be choking, and agonal respirations are misinterpreted to mean the victim is alive. Making sense of the experience is challenging, at least in the short term, where lay rescuers have to contend with self-doubt, unanswered questions, and uncomfortable emotional reactions to a traumatic event. Our study suggests that current CPR training programs may not adequately prepare lay rescuers for the reality of an OHCA and identifies several key knowledge gaps that should be addressed. The long-term psychological consequences of bystander intervention in OHCA remain poorly understood and warrant further study. © 2018 American Heart Association, Inc.

The response time threshold for predicting favourable neurological outcomes in patients with bystander-witnessed out-of-hospital cardiac arrest.

PubMed

Ono, Yuichi; Hayakawa, Mineji; Iijima, Hiroaki; Maekawa, Kunihiko; Kodate, Akira; Sadamoto, Yoshihiro; Mizugaki, Asumi; Murakami, Hiromoto; Katabami, Kenichi; Sawamura, Atsushi; Gando, Satoshi

2016-10-01

It is well established that the period of time between a call being made to emergency medical services (EMS) and the time at which the EMS arrive at the scene (i.e. the response time) affects survival outcomes in patients who experience out-of-hospital cardiac arrest (OHCA). However, the relationship between the response time and favourable neurological outcomes remains unclear. We therefore aimed to determine a response time threshold in patients with bystander-witnessed OHCA that is associated with positive neurological outcomes and to assess the relationship between the response time and neurological outcomes in patients with OHCA. This study was a retrospective, observational analysis of data from 204,277 episodes of bystander-witnessed OHCA between 2006 and 2012 in Japan. We used classification and regression trees (CARTs) and receiver operating characteristic (ROC) curve analyses to determine the threshold of response time associated with favourable neurological outcomes (Cerebral Performance Category 1 or 2) 1 month after cardiac arrest. Both CARTs and ROC analyses indicated that a threshold of 6.5min was associated with improved neurological outcomes in all bystander-witnessed OHCA events of cardiac origin. Furthermore, bystander cardiopulmonary resuscitation (CPR) prolonged the threshold of response time by 1min (up to 7.5min). The adjusted odds ratio for favourable neurological outcomes in patients with OHCA who received care within ≤6.5min was 1.935 (95% confidential interval: 1.834-2.041, P<0.001). A response time of ≤6.5min was closely associated with favourable neurological outcomes in all bystander-witnessed patients with OHCA. Bystander CPR prolonged the response time threshold by 1min. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

To act or not to act, that is the question? Barriers and facilitators of bystander intervention.

PubMed

Bennett, Sidney; Banyard, Victoria L; Garnhart, Lydia

2014-02-01

A promising line of inquiry in sexual violence prevention involves training potential bystanders to intervene in situations where there is risk for violence. Theories of bystander intervention often discuss barriers to helping behavior, but there has been little empirical inquiry into this question. We will present findings of a study of both barriers and facilitators of helping behavior in the context of sexual violence among first-semester college students. Two hundred and forty-two first year college students completed surveys during their first year of college. Measures included assessment of bystander behavior, perceived barriers to helping, as well as a variety of other variables identified in the literature as key correlates of helping. Quantitative and qualitative analyses were used to (a) describe barriers and facilitators of helping, (b) examine the relationship between barriers and self-reports of helping, and (c) model individual differences in helping behavior. In quantitative analyses, barriers, as assessed in this study, were better predictors of helping behavior directed at strangers than helping of friends. Results suggested that open-ended responses about the facilitators and barriers to helping for sexual violence map well onto social-psychological models of bystander behavior, and that greater prosocial tendencies, an intrapersonal variable, increase actual helping behavior. A more specific understanding of what promotes and hinders helping can be used to enhance prevention education efforts focused on increasing helpful bystander actions.

The Killing of Kitty Genovese: What Else Does This Case Tell Us?

PubMed

Kassin, Saul M

2017-05-01

Well known in popular culture, the 1964 murder of Kitty Genovese in Queens, New York, became famous because not one of an alleged 38 bystanders called police until it was too late. Within psychology, this singular event inspired the study of bystander intervention. With the spotlight of history focused on Ms. Genovese and bystanders, other events, also profound for what they tell us about human social behavior, have escaped public notice. Based on archival records and current interviews, this article describes the three issues linked to Genovese. First, three false confessions, taken from two individuals, led to their wrongful convictions and imprisonment. One of these individuals was cited by the U.S. Supreme Court in Miranda v. Arizona (1966); the other individual is alive and well and wants to clear his name. Second, the narrative of the unresponsive bystander was initiated by police, not by journalists, in response to probing questions about one of these confessions. Finally, there is the ironic fact, which somehow has slipped through the cracks, that the killer of Genovese was ultimately captured as a result of the intervention of two bystanders.

Power effects on implicit prejudice and stereotyping: The role of intergroup face processing.

PubMed

Schmid, Petra C; Amodio, David M

2017-04-01

Power is thought to increase discrimination toward subordinate groups, yet its effect on different forms of implicit bias remains unclear. We tested whether power enhances implicit racial stereotyping, in addition to implicit prejudice (i.e., evaluative associations), and examined the effect of power on the automatic processing of faces during implicit tasks. Study 1 showed that manipulated high power increased both forms of implicit bias, relative to low power. Using a neural index of visual face processing (the N170 component of the ERP), Study 2 revealed that power affected the encoding of White ingroup vs. Black outgroup faces. Whereas high power increased the relative processing of outgroup faces during evaluative judgments in the prejudice task, it decreased the relative processing of outgroup faces during stereotype trait judgments. An indirect effect of power on implicit prejudice through enhanced processing of outgroup versus ingroup faces suggested a potential link between face processing and implicit bias. Together, these findings demonstrate that power can affect implicit prejudice and stereotyping as well as early processing of racial ingroup and outgroup faces.

Buffer Zone Fact Sheets

EPA Pesticide Factsheets

New requirements for buffer zones and sign posting contribute to soil fumigant mitigation and protection for workers and bystanders. The buffer provides distance between the pesticide application site and bystanders, reducing exposure risk.

Effects of pretesting implicit self-determined motivation on behavioral engagement: evidence for the mere measurement effect at the implicit level.

PubMed

Keatley, David A; Clarke, David D; Ferguson, Eamonn; Hagger, Martin S

2014-01-01

Research into individuals' intended behavior and performance has traditionally adopted explicitly measured, self-report constructs, and outcomes. More recently, research has shown that completing explicit self-report measures of constructs may effect subsequent behavior, termed the "mere measurement" effect. The aim of the present experiment was to investigate whether implicit measures of motivation showed a similar mere measurement effect on subsequent behavior. It may be the case that measuring the implicit systems affects subsequent implicit interventions (e.g., priming), observable on subsequent behavior. Priming manipulations were also given to participants in order to investigate the interaction between measurement and priming of motivation. Initially, a 2 [implicit association test (IAT: present vs. absent) ×2 (Prime: autonomous vs. absent) and a 2 (IAT: present vs. absent) × 2 (Prime: controlled vs. absent)] between participants designs were conducted, these were them combined into a 2 (IAT: present vs. absent) ×3 (Prime: autonomous vs. controlled vs. absent) between participants design, with attempts at a novel task taken as the outcome measure. Implicit measure completion significantly decreased behavioral engagement. Priming autonomous motivation significantly facilitated, and controlled motivation significantly inhibited performance. Finally, there was a significant implicit measurement × priming interaction, such that priming autonomous motivation only improved performance in the absence of the implicit measure. Overall, this research provides an insight into the effects of implicit measurement and priming of motivation and the combined effect of completing both tasks on behavior.

Instructions to "put the phone down" do not improve the quality of bystander initiated dispatcher-assisted cardiopulmonary resuscitation.

PubMed

Brown, Todd B; Saini, Devashish; Pepper, Tracy; Mirza, Muzna; Nandigam, Hari Krishna; Kaza, Niroop; Cofield, Stacey S

2008-02-01

The quality of early bystander CPR appears important in maximizing survival. This trial tests whether explicit instructions to "put the phone down" improve the quality of bystander initiated dispatch-assisted CPR. In a randomized, double-blinded, controlled trial, subjects were randomized to a modified version of the Medical Priority Dispatch System (MPDS) version 11.2 protocol or a simplified protocol, each with or without instruction to "put the phone down" during CPR. Data were recorded from a Laerdal Resusci Anne Skillreporter manikin. A simulated emergency medical dispatcher, contacted by cell phone, delivered standardized instructions. Primary outcome measures included chest compression rate, depth, and the proportion of compressions without error, with correct hand position, adequate depth, and total release. Time was measured in two distinct ways: time required for initiation of CPR and total amount of time hands were off the chest during CPR. Proportions were analyzed by Wilcoxon rank sum tests and time variables with ANOVA. All tests used a two-sided alpha-level of 0.05. Two hundred and fifteen subjects were randomized-107 in the "put the phone down" instruction group and 108 in the group without "put the phone down" instructions. The groups were comparable across demographic and experiential variables. The additional instruction to "put the phone down" had no effect on the proportion of compressions administered without error, with the correct depth, and with the correct hand position. Likewise, "put the phone down" did not affect the average compression depth, the average compression rate, the total hands-off-chest time, or the time to initiate chest compressions. A statistically significant, yet trivial, effect was found in the proportion of compressions with total release of the chest wall. Instructions to "put the phone down" had no effect on the quality of bystander initiated dispatcher-assisted CPR in this trial.

Dose Calculations for [131I] Meta-Iodobenzylguanidine-Induced Bystander Effects

PubMed Central

Gow, M. D.; Seymour, C. B.; Boyd, M.; Mairs, R. J.; Prestiwch, W. V.; Mothersill, C. E.

2014-01-01

Targeted radiotherapy is a potentially useful treatment for some cancers and may be potentiated by bystander effects. However, without estimation of absorbed dose, it is difficult to compare the effects with conventional external radiation treatment. Methods: Using the Vynckier – Wambersie dose point kernel, a model for dose rate evaluation was created allowing for calculation of absorbed dose values to two cell lines transfected with the noradrenaline transporter (NAT) gene and treated with [131I]MIBG. Results: The mean doses required to decrease surviving fractions of UVW/NAT and EJ138/NAT cells, which received medium from [131I]MIBG-treated cells, to 25 – 30% were 1.6 and 1.7 Gy respectively. The maximum mean dose rates achieved during [131I]MIBG treatment were 0.09 – 0.75 Gy/h for UVW/NAT and 0.07 – 0.78 Gy/h for EJ138/NAT. These were significantly lower than the external beam gamma radiation dose rate of 15 Gy/h. In the case of control lines which were incapable of [131I]MIBG uptake the mean absorbed doses following radiopharmaceutical were 0.03 – 0.23 Gy for UVW and 0.03 – 0.32 Gy for EJ138. Conclusion: [131I]MIBG treatment for ICCM production elicited a bystander dose-response profile similar to that generated by external beam gamma irradiation but with significantly greater cell death. PMID:24659931

Combating weight-based cyberbullying on Facebook with the dissenter effect.

PubMed

Anderson, Jenn; Bresnahan, Mary; Musatics, Catherine

2014-05-01

Weight-based cyberbullying is prevalent among youth and adolescents and can have lasting negative psychological effects on the victims. One way to combat these negative effects is through modeling dissenting behavior. When a bystander challenges the bully or supports the victim, this models dissenting behavior. In this study, 181 participants were exposed to message manipulations posted on a Facebook page aimed at testing the conformity effect, the dissenter effect, and the bystander effect in response to enactment of weight-based bullying. Facebook is a common social media site where cyberbullying is reported. Results indicate that in the dissenting condition, participants' comments were significantly more positive or supporting for the victim, as compared to other conditions. This effect was more pronounced for men than for women. In addition, in the dissenting condition, men were less likely to consider the victim unhealthy than women and men in other conditions. These results support the effectiveness of efforts to model dissenting behavior in the face of bullies and extend them to online contexts. Implications are discussed.

How "implicit" are implicit color effects in memory?

PubMed

Zimmer, Hubert D; Steiner, Astrid; Ecker, Ullrich K H

2002-01-01

Processing colored pictures of objects results in a preference to choose the former color for a specific object in a subsequent color choice test (Wippich & Mecklenbräuker, 1998). We tested whether this implicit memory effect is independent of performances in episodic color recollection (recognition). In the study phase of Experiment 1, the color of line drawings was either named or its appropriateness was judged. We found only weak implicit memory effects for categorical color information. In Experiment 2, silhouettes were colored by subjects during the study phase. Performances in both the implicit and the explicit test were good. Selections of "old" colors in the implicit test, though, were almost completely confined to items for which the color was also remembered explicitly. In Experiment 3, we applied the opposition technique in order to check whether we could find any implicit effects regarding items for which no explicit color recollection was possible. This was not the case. We therefore draw the conclusion that implicit color preference effects are not independent of explicit recollection, and that they are probably based on the same episodic memory traces that are used in explicit tests.

RETRACTED ARTICLE: Personal distress, but not sympathy, predicts the negative influence of bystanders on responding to an emergency.

PubMed

2015-06-01

At the request of the authors this article has been retracted. During the preparation of a follow-up study, a mistake was found in the experimental script of the cued reaction time task of experiment 2. Four out of six conditions were mislabeled. Consequently, the reported findings and their interpretation and discussion are incorrect. Careful reexamination and reanalyzing of the data using the correct labels revealed a pattern of results that is not entirely compatible with several of the main claims of the article. Importantly, the corrected results show that reaction times do not increase with more bystanders present at an emergency.Moreover, not only personal distress but also perspective taking predicts the negative influence of bystanders on reaction times.We believe that these new findings undermine our central claim of decreased action preparation as a function of bystanders present at an emergency and the enhancement of this effect in people with higher levels of trait personal distress. While the results and discussion of experiment 1 and 3 remain correct, the new results of experiment 2 influence the article to such an extent that we currently see no other option than to retract the article from publication. We will continue to work on this topic and hope to publish the new results in due time. We deeply regret the publication of invalid results.We sincerely apologize to the Editor and reviewers of the manuscript, and the readers of Cognitive, Affective, & Behavioral Neuroscience.

Genomic regulatory blocks encompass multiple neighboring genes and maintain conserved synteny in vertebrates

PubMed Central

Kikuta, Hiroshi; Laplante, Mary; Navratilova, Pavla; Komisarczuk, Anna Z.; Engström, Pär G.; Fredman, David; Akalin, Altuna; Caccamo, Mario; Sealy, Ian; Howe, Kerstin; Ghislain, Julien; Pezeron, Guillaume; Mourrain, Philippe; Ellingsen, Staale; Oates, Andrew C.; Thisse, Christine; Thisse, Bernard; Foucher, Isabelle; Adolf, Birgit; Geling, Andrea; Lenhard, Boris; Becker, Thomas S.

2007-01-01

We report evidence for a mechanism for the maintenance of long-range conserved synteny across vertebrate genomes. We found the largest mammal-teleost conserved chromosomal segments to be spanned by highly conserved noncoding elements (HCNEs), their developmental regulatory target genes, and phylogenetically and functionally unrelated “bystander” genes. Bystander genes are not specifically under the control of the regulatory elements that drive the target genes and are expressed in patterns that are different from those of the target genes. Reporter insertions distal to zebrafish developmental regulatory genes pax6.1/2, rx3, id1, and fgf8 and miRNA genes mirn9-1 and mirn9-5 recapitulate the expression patterns of these genes even if located inside or beyond bystander genes, suggesting that the regulatory domain of a developmental regulatory gene can extend into and beyond adjacent transcriptional units. We termed these chromosomal segments genomic regulatory blocks (GRBs). After whole genome duplication in teleosts, GRBs, including HCNEs and target genes, were often maintained in both copies, while bystander genes were typically lost from one GRB, strongly suggesting that evolutionary pressure acts to keep the single-copy GRBs of higher vertebrates intact. We show that loss of bystander genes and other mutational events suffered by duplicated GRBs in teleost genomes permits target gene identification and HCNE/target gene assignment. These findings explain the absence of evolutionary breakpoints from large vertebrate chromosomal segments and will aid in the recognition of position effect mutations within human GRBs. PMID:17387144

Electronic Cigarettes and Indoor Air Quality: A Simple Approach to Modeling Potential Bystander Exposures to Nicotine

PubMed Central

Colard, Stéphane; O’Connell, Grant; Verron, Thomas; Cahours, Xavier; Pritchard, John D.

2014-01-01

There has been rapid growth in the use of electronic cigarettes (“vaping”) in Europe, North America and elsewhere. With such increased prevalence, there is currently a debate on whether the aerosol exhaled following the use of e-cigarettes has implications for the quality of air breathed by bystanders. Conducting chemical analysis of the indoor environment can be costly and resource intensive, limiting the number of studies which can be conducted. However, this can be modelled reasonably accurately based on empirical emissions data and using some basic assumptions. Here, we present a simplified model, based on physical principles, which considers aerosol propagation, dilution and extraction to determine the potential contribution of a single puff from an e-cigarette to indoor air. From this, it was then possible to simulate the cumulative effect of vaping over time. The model was applied to a virtual, but plausible, scenario considering an e-cigarette user and a non-user working in the same office space. The model was also used to reproduce published experimental studies and showed good agreement with the published values of indoor air nicotine concentration. With some additional refinements, such an approach may be a cost-effective and rapid way of assessing the potential exposure of bystanders to exhaled e-cigarette aerosol constituents. PMID:25547398

Vaccination Expands Antigen-Specific CD4+ Memory T Cells and Mobilizes Bystander Central Memory T Cells

PubMed Central

Li Causi, Eleonora; Parikh, Suraj C.; Chudley, Lindsey; Layfield, David M.; Ottensmeier, Christian H.; Stevenson, Freda K.; Di Genova, Gianfranco

2015-01-01

CD4+ T helper memory (Thmem) cells influence both natural and vaccine-boosted immunity, but mechanisms for their maintenance remain unclear. Pro-survival signals from the common gamma-chain cytokines, in particular IL-7, appear important. Previously we showed in healthy volunteers that a booster vaccination with tetanus toxoid (TT) expanded peripheral blood TT-specific Thmem cells as expected, but was accompanied by parallel increase of Thmem cells specific for two unrelated and non cross-reactive common recall antigens. Here, in a new cohort of healthy human subjects, we compare blood vaccine-specific and bystander Thmem cells in terms of differentiation stage, function, activation and proliferative status. Both responses peaked 1 week post-vaccination. Vaccine-specific cytokine-producing Thmem cells were predominantly effector memory, whereas bystander cells were mainly of central memory phenotype. Importantly, TT-specific Thmem cells were activated (CD38High HLA-DR+), cycling or recently divided (Ki-67+), and apparently vulnerable to death (IL-7RαLow and Bcl-2 Low). In contrast, bystander Thmem cells were resting (CD38Low HLA-DR- Ki-67-) with high expression of IL-7Rα and Bcl-2. These findings allow a clear distinction between vaccine-specific and bystander Thmem cells, suggesting the latter do not derive from recent proliferation but from cells mobilized from as yet undefined reservoirs. Furthermore, they reveal the interdependent dynamics of specific and bystander T-cell responses which will inform assessments of responses to vaccines. PMID:26332995

[Effects of an implicit internal working model on attachment in information processing assessed using Go/No-Go Association Task].

PubMed

Fujii, Tsutomu; Uebuchi, Hisashi; Yamada, Kotono; Saito, Masahiro; Ito, Eriko; Tonegawa, Akiko; Uebuchi, Marie

2015-06-01

The purposes of the present study were (a) to use both a relational-anxiety Go/No-Go Association Task (GNAT) and an avoidance-of-intimacy GNAT in order to assess an implicit Internal Working Model (IWM) of attachment; (b) to verify the effects of both measured implicit relational anxiety and implicit avoidance of intimacy on information processing. The implicit IWM measured by GNAT differed from the explicit IWM measured by questionnaires in terms of the effects on information processing. In particular, in subliminal priming tasks involving with others, implicit avoidance of intimacy predicted accelerated response times with negative stimulus words about attachment. Moreover, after subliminally priming stimulus words about self, implicit relational anxiety predicted delayed response times with negative stimulus words about attachment.

The Intergenerational Transmission of Implicit and Explicit Attitudes Toward Smoking

PubMed Central

Sherman, Steven J.; Chassin, Laurie; Presson, Clark; Seo, Dong-Chul; Macy, Jonathan T.

2009-01-01

This study examined the intergenerational transmission of implicit and explicit attitudes toward smoking, as well as the role of these attitudes in adolescents’ smoking initiation. There was evidence of intergenerational transmission of implicit attitudes. Mothers who had more positive implicit attitudes had children with more positive implicit attitudes. In turn, these positive implicit attitudes of adolescents predicted their smoking initiation 18-months later. Moreover, these effects were obtained above and beyond the effects of explicit attitudes. These findings provide the first evidence that the intergenerational transmission of implicit cognition may play a role in the intergenerational transmission of an addictive behavior. PMID:20126293

Gamma-H2AX as a biomarker of DNA damage induced by ionizing radiation in targeted and bystander human artificial skin models and peripheral blood lymphocytes

NASA Astrophysics Data System (ADS)

Redon, Christophe; Dickey, Jennifer; Bonner, William; Sedelnikova, Olga

Ionizing radiation (IR) exposure is inevitable. In addition to exposure from cosmic rays, the sun and radioactive substances, modern society has created new sources of radiation exposure such as space and high altitude journeys, X-ray diagnostics, radiological treatments and the increasing threat of radiobiological terrorism. For these reasons, a reliable, reproducible and sensitive assessment of dose and time exposure to IR is essential. We developed a minimally invasive diagnostic test for IR exposure based on detection of a phosphorylated variant of histone H2AX (gamma-H2AX), which occurs specifically at sites of DNA double-strand breaks (DSBs). The phosphorylation of thousands of H2AX molecules forms a gamma-H2AX focus in the chromatin flanking the DSB site that can be detected in situ. We analyzed gamma- H2AX focus formation in both directly irradiated cells as well as in un-irradiated "bystanders" in close contact with irradiated cells. In order to insure minimal invasiveness, we examined commercially available artificial skin models as a surrogate for human skin biopsies as well as peripheral blood lymphocytes. In human skin models, cells in a thin plane were microbeamirradiated and gamma-H2AX formation was measured both in irradiated and in distal bystander cells over time. In irradiated cells DSB formation reached a maximum at 15-30 minutes post- IR and then declined within several hours; all cells were affected. In marked contrast, the incidence of DSBs in bystander cells reached a maximum by 12-48 hours post-irradiation, gradually decreasing over the 7 day time course. At the maxima, 40-60% of bystander cells were affected. Similarly, we analyzed blood samples exposed to IR ex vivo at doses ranging from 0.02 to 3 Gy. The amount of DNA damage was linear in respect to radiation dose and independent of the age or sex of the blood donor. The method is highly reproducible and highly sensitive. In directly irradiated cells, the number of gamma-H2AX foci peaked 30 min after irradiation and then declined at a relatively steady pace as the cell repaired the DNA damage. Radiation effects were still detectable after 48 hrs for doses greater than 1 Gy and remained linear to initial dose. Activated bystander lymphocytes cultured with media from irradiated lymphocytes exhibited a two-fold increased damage response as seen by gamma- H2AX formation. The effect reached a maximum 3 hrs post-exposure and was retained for over 24 hrs. Thus, detection of gamma-H2AX formation to determine DNA damage in a minimally invasive skin test and a non-invasive blood test could be useful and promising tools to analyze direct and indirect effects of radiation exposure.

See Something, Do Something: Predicting Sexual Assault Bystander Intentions in the U.S. Military.

PubMed

Holland, Kathryn J; Rabelo, Verónica Caridad; Cortina, Lilia

2016-09-01

Sexual assault is a pervasive problem in the U.S. military, especially against women. Bystander intervention is increasingly promoted as important for reducing sexual violence, and it may be particularly helpful in contexts with high rates of sexual violence. Bystander training encourages and enables people to intervene safely and stop sexual violence. In this study, we drew from an ecological model to investigate intrapersonal, microsystem, and exosystem factors that predicted Service members' assumption of personal responsibility to intervene in an alcohol-involved sexual assault. Moreover, we examined how these predictors played a role in decisions about how to intervene: confronting the perpetrator, assisting the victim, or finding someone to help. We analyzed data from 24,610 active duty personnel collected by the Department of Defense. Several factors significantly related to Service members' bystander intentions: gender, rank, morale, attitudes about sexual assault, training, and trust in the military sexual assault system predicted the likelihood and method of bystander intervention. These findings help identify how and why people intervene (or fail to intervene) when they witness situations that could develop into sexual violence. © Society for Community Research and Action 2016.

The New Zealand child work-related fatal injury study: 1985-1998.

PubMed

Lilley, Rebbecca; Feyer, Anne-Marie; Langley, John; Wren, John

2004-05-21

To estimate the numbers and rates of work-related fatal injury for children under the age of 15 years. Potential cases of work-related injury deaths of persons aged <15 years of age were identified from the national electronic mortality data-files for the period 1985-1998 inclusive. The circumstances of the death in each fatality incident were reviewed directly from coronial files to determine work-relatedness. A total of 87 workplace work-related fatalities were identified. The vast majority of children identified were fatally injured while a bystander to another person's work. Workplace bystander involvement was found to vary by age, with the majority of workers identified aged 10-14 years old. With a third of all fatalities, the agricultural industry was the most common industry for workplace work-related fatalities in children. In the period 1985-94, children <15 years of age were found to account for 46% of New Zealand's total workplace bystander deaths. Children contribute significantly to the overall burden of work-related fatal injury in New Zealand, especially as bystanders to other people's work. The high contribution to bystander deaths by children aged <15 years suggests that hazard control in certain work settings is lacking.

The role of the bystander in the social architecture of bullying and violence in schools and communities.

PubMed

Twemlow, Stuart W; Fonagy, Peter; Sacco, Frank C

2004-12-01

The bystander is defined as an active and involved participant in the social architecture of school violence, rather than a passive witness. Bullying is redefined from a triadic (bully-victim-bystander) rather than dyadic (bully-victim) perspective. Teachers, including administrators, and students can promote or ameliorate bullying and other forms of violence when in this social role. Cases are used to illustrate this phenomenon, including one in which a teacher is murdered. Data are presented from a study of teachers' perceptions of other teachers who bully students, suggesting that bullying of students by teachers and bullying of teachers by students is a factor in the aggravation of school bullying and violence that needs to be more openly discussed. An intervention in nine elementary schools involving 3,600 students is outlined to illustrate how a focus on reflective mentalizing and awareness of the importance of the helpful bystander role can promote a peaceful school-learning environment for students and teachers. The paper concludes with an outline for research into how communities and schools adopt bystanding roles when faced with complex problems like youth violence, and how they may avoid facing the problems by blaming law enforcement and educators.

"Whether I like it or not, it's important": Implicit importance of means predicts self-regulatory persistence and success.

PubMed

Critcher, Clayton R; Ferguson, Melissa J

2016-06-01

To effectively self-regulate, people must persevere on tasks that they deem important, regardless of whether those tasks are enjoyable. Building on past work that has noted the fundamental role of implicit cognition in guiding effective self-regulation, the present paper tests whether an implicit association between goal means and importance predicts self-regulatory persistence and success. Implicit importance predicted markers of effective self-regulation-better grades, more studying and exercise, and stronger standardized testing performance-over and above, and often better than, explicit beliefs about the importance of that self-regulation, as well as implicit evaluations of those means. In particular, those for whom tasks were fairly taxing to complete (i.e., those for whom this self-regulation required effortful self-control) were those who most benefitted from the implicit association between means and importance. Moreover, when participants were reminded of recent self-regulatory failure that they believed could be overcome through hard work, implicit importance toward the means increased as if to prepare them to achieve self-regulatory persistence. A final study sought to reconcile the present findings with previous work showing the key role that implicit evaluations play in effective self-regulation. We reasoned that means are important precisely because they are associated with valued end-states. Consistent with this account, implicit evaluations of end-states predicted the implicit importance of means, which in turn predicted effective self-regulation. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Grid therapy using high definition multileaf collimators: realizing benefits of the bystander effect.

PubMed

Peng, Valery; Suchowerska, Natalka; Rogers, Linda; Claridge Mackonis, Elizabeth; Oakes, Samantha; McKenzie, David R

2017-08-01

In microbeam radiotherapy (MRT), parallel arrays of high-intensity synchrotron x-ray beams achieve normal tissue sparing without compromising tumor control. Grid-therapy using clinical linacs has spatial modulation on a larger scale and achieves promising results for palliative treatments of bulky tumors. The availability of high definition multileaf collimators (HDMLCs) with 2.5 mm leaves provides an opportunity for grid-therapy to more closely approach MRT. However, challenges to the wider implementation of grid-therapy remain because spatial modulation of the target volume runs counter to current radiotherapy practice and mechanisms for the beneficial effects of MRT are not fully understood. Without more knowledge of cell dose responses, a quantitative basis for planning treatments is difficult. The aim of this study is to determine if therapeutic benefits of MRT can be achieved using a linac with HDMLCs and if so, to develop a predictive model to support treatment planning. HD120-MLCs of a Varian Novalis TX TM were used to generate grid patterns of 2.5 and 5.0 mm spacing, which were characterized dosimetrically using Gafchromic TM EBT3 film. Clonogenic survival of normal (HUVEC) and cancer (NCI-H460, HCC-1954) cell lines following irradiation under the grid and open fields using a 6 MV photon beam were compared in-vitro for the same average dose. Relative to an open field, survival of normal cells in a 2.5 mm striped field was the same, while the survival of both cancer cell lines was significantly lower. A mathematical model was developed to incorporate dose gradients of the spatial modulation into the standard linear quadratic model. Our new bystander extended LQ model assumes spatial gradients drive the diffusion of soluble factors that influence survival through bystander effects, successfully predicting the experimental results that show an increased therapeutic ratio. Our results challenge conventional radiotherapy practice and propose that additional gain can be realized by prescribing spatially modulated treatments to harness the bystander effect.

Workplace mobbing: How the victim's coping behavior influences bystander responses.

PubMed

Mulder, Roelie; Bos, Arjan E R; Pouwelse, Mieneke; van Dam, Karen

2017-01-01

Victims of workplace mobbing show diverse coping behavior. We investigated the impact of this behavior on bystander cognitions, emotions, and helping toward the victim, integrating coping literature with attribution theory. Adult part-time university students (N = 161) working at various organizations participated in a study with a 3(Coping: approach/avoidance/neutral) × 2(Gender Victim: male/female) × 2(Gender Bystander: male/female) design. Victims showing approach (vs. avoidance) coping were considered to be more self-reliant and less responsible for the continuation of the mobbing, and they elicited less anger. Continuation responsibility and self-reliance mediated the relationship between the victim's coping behavior and bystanders' helping intentions. Female (vs. male) participants reported more sympathy for the victim and greater willingness to help, and female (vs. male) victims elicited less anger. Theoretical and practical implications of the findings are discussed.

Bystander CD4+ T lymphocytes survive in HIV-infected human lymphoid tissue

NASA Technical Reports Server (NTRS)

Grivel, Jean-Charles; Biancotto, Angelique; Ito, Yoshinori; Lima, Rosangela G.; Margolis, Leonid B.

2003-01-01

HIV infection is associated with depletion of CD4(+) T cells. The mechanisms of this phenomenon remain to be understood. In particular, it remains controversial whether and to what extent uninfected ("bystander") CD4(+) T cells die in HIV-infected individuals. We address this question using a system of human lymphoid tissue ex vivo. Tissue blocks were inoculated with HIV-1. After productive infection was established, they were treated with the reverse transcriptase inhibitor nevirapine to protect from infection those CD4(+) T cells that had not yet been infected. These CD4(+) T cells residing in HIV-infected tissue are by definition bystanders. Our results demonstrate that after nevirapine application the number of bystander CD4(+) T cells is conserved. Thus, in the context of HIV-infected human lymphoid tissue, productive HIV infection kills infected cells but is not sufficient to cause the death of a significant number of uninfected CD4(+) T cells.

Context Effects of Alcohol Availability at Home: Implicit Alcohol Associations and the Prediction of Adolescents' Drinking Behavior.

PubMed

Peeters, Margot; Koning, Ina; Monshouwer, Karin; Vollebergh, Wilma A M; Wiers, Reinout W

2016-09-01

Recent studies suggest that the predictive effect of implicit alcohol associations is context dependent. Findings indicate that implicit associations are more easily retrieved in an alcohol-associated setting or context (e.g., bar) compared with a neutral setting. In line with this reasoning, we hypothesized that alcohol availability at home might moderate the relationship between implicit alcohol associations and future drinking behavior of adolescents. Participants were 262 at-risk adolescents (235 boys, 27 girls, adolescents with externalizing behavioral problems) with a mean age of 14.11 years (SD = 0.86, age range: 12-16 years) at baseline. Adolescents completed a questionnaire and a modified version of the Implicit Association Test (i.e., Single Category Implicit Association Test; SC-IAT). Stronger implicit alcohol associations predicted increase in frequency of alcohol use, only in adolescents who indicated that alcohol was available at home. No moderating effects were found for increase in quantity of alcohol use and problematic alcohol use, suggesting that implicit alcohol associations particularly influence the decision of whether to drink in adolescence. The findings illustrate that the availability of alcohol in the home setting influences adolescents' implicit alcohol associations and consequently affects the frequency of alcohol use. In this way, alcohol availability at home may be an important contextual factor to consider when examining the effect of implicit alcohol associations on the future drinking behavior of adolescents.

Push hard, push fast, if you’re downtown: a citation review of urban-centrism in American and European basic life support guidelines

PubMed Central

2013-01-01

Bystander cardiopulmonary resuscitation (CPR) improves out-of-hospital cardiac arrest (OHCA) survival. In settings with prolonged ambulance response times, skilled bystanders may be even more crucial. In 2010, American Heart Association (AHA) and European Resuscitation Council (ERC) introduced compression-only CPR as an alternative to conventional bystander CPR under some circumstances. The purpose of this citation review and document analysis is to determine whether the evidentiary basis for 2010 AHA and ERC guidelines attends to settings with prolonged ambulance response times or no formal ambulance dispatch services. Primary and secondary citations referring to epidemiological research comparing adult OHCA survival based on the type of bystander CPR were included in the analysis. Details extracted from the citations included a study description and primary outcome measure, the geographic location in which the study occurred, EMS response times, the role of dispatchers, and main findings and summary statistics regarding rates of survival among patients receiving no CPR, conventional CPR or compression-only CPR. The inclusion criteria were met by 10 studies. 9 studies took place exclusively in urban settings. Ambulance dispatchers played an integral role in 7 studies. The cited studies suggest either no survival benefit or harm arising from compression-only CPR in settings with extended ambulance response times. The evidentiary basis for 2010 AHA and ERC bystander CPR guidelines does not attend to settings without rapid ambulance response times or dispatch services. Standardized bystander CPR guidelines may require adaptation or reconsideration in these settings. PMID:23601200

Bystander killing effect of DS-8201a, a novel anti-human epidermal growth factor receptor 2 antibody-drug conjugate, in tumors with human epidermal growth factor receptor 2 heterogeneity.

PubMed

Ogitani, Yusuke; Hagihara, Katsunobu; Oitate, Masataka; Naito, Hiroyuki; Agatsuma, Toshinori

2016-07-01

Antibody-drug conjugates deliver anticancer agents selectively and efficiently to tumor tissue and have significant antitumor efficacy with a wide therapeutic window. DS-8201a is a human epidermal growth factor receptor 2 (HER2)-targeting antibody-drug conjugate prepared using a novel linker-payload system with a potent topoisomerase I inhibitor, exatecan derivative (DX-8951 derivative, DXd). It was effective against trastuzumab emtansine (T-DM1)-insensitive patient-derived xenograft models with both high and low HER2 expression. In this study, the bystander killing effect of DS-8201a was evaluated and compared with that of T-DM1. We confirmed that the payload of DS-8201a, DXd (1), was highly membrane-permeable whereas that of T-DM1, Lys-SMCC-DM1, had a low level of permeability. Under a coculture condition of HER2-positive KPL-4 cells and negative MDA-MB-468 cells in vitro, DS-8201a killed both cells, whereas T-DM1 and an antibody-drug conjugate with a low permeable payload, anti-HER2-DXd (2), did not. In vivo evaluation was carried out using mice inoculated with a mixture of HER2-positive NCI-N87 cells and HER2-negative MDA-MB-468-Luc cells by using an in vivo imaging system. In vivo, DS-8201a reduced the luciferase signal of the mice, indicating suppression of the MDA-MB-468-Luc population; however, T-DM1 and anti-HER2-DXd (2) did not. Furthermore, it was confirmed that DS-8201a was not effective against MDA-MB-468-Luc tumors inoculated at the opposite side of the NCI-N87 tumor, suggesting that the bystander killing effect of DS-8201a is observed only in cells neighboring HER2-positive cells, indicating low concern in terms of systemic toxicity. These results indicated that DS-8201a has a potent bystander effect due to a highly membrane-permeable payload and is beneficial in treating tumors with HER2 heterogeneity that are unresponsive to T-DM1. © 2016 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

Viewing an ultra-brief chest compression only video improves some measures of bystander CPR performance and responsiveness at a mass gathering event.

PubMed

Beskind, Daniel L; Stolz, Uwe; Thiede, Rebecca; Hoyer, Riley; Robertson, Whitney; Brown, Jeffrey; Ludgate, Melissa; Tiutan, Timothy; Shane, Romy; McMorrow, Deven; Pleasants, Michael; Kern, Karl B; Panchal, Ashish R

2017-09-01

CPR training at mass gathering events is an important part of health initiatives to improve cardiac arrest survival. However, it is unclear whether training lay bystanders using an ultra-brief video at a mass gathering event improves CPR quality and responsiveness. To determine if showing a chest-compression only (CCO) Ultra-Brief Video (UBV) at a mass gathering event is effective in teaching lay bystanders CCO-CPR. Prospective control trial in adults (age >18) who attended either a women's University of Arizona or a men's Phoenix Suns basketball game. Participants were evaluated using a standardized cardiac arrest scenario with Laerdal Skillreporter™ mannequins. CPR responsiveness (calling 911, time to calling 911, starting compressions within two minutes) and quality (compression rate, depth, hands-off time) were assessed for participants and data collected at Baseline and Post-intervention. Different participants were tested before and after the exposure of the UBV. Data were analyzed via the intention to treat principle using logistic regression for binary outcomes and median regression for continuous outcomes, controlling for clustering by venue. A total of 96 people were consented (Baseline=45; Post intervention=51). CPR responsiveness post intervention improved with faster time to calling 911 (s) and time to starting compressions (sec). Likewise, CPR quality improved with deeper compressions and improved hands-off time. Showing a UBV at a mass gathering sporting event is associated with improved CPR responsiveness and performance for lay bystanders. This data provides further support for the use of mass media interventions. Copyright © 2017 Elsevier B.V. All rights reserved.

40 CFR 158.2270 - Post-application exposure.

Code of Federal Regulations, 2013 CFR

2013-07-01

... and the human activities associated with the pesticide's use pattern can lead to potential adverse...) Occupational human post-application or bystander exposure to residues of antimicrobial pesticides could occur... human post-application or bystander exposure to residues of antimicrobial pesticides could occur...

40 CFR 158.2270 - Post-application exposure.

Code of Federal Regulations, 2014 CFR

2014-07-01

... and the human activities associated with the pesticide's use pattern can lead to potential adverse...) Occupational human post-application or bystander exposure to residues of antimicrobial pesticides could occur... human post-application or bystander exposure to residues of antimicrobial pesticides could occur...

Empowering bystanders to prevent campus violence against women: a preliminary evaluation of a poster campaign.

PubMed

Potter, Sharyn J; Moynihan, Mary M; Stapleton, Jane G; Banyard, Victoria L

2009-01-01

Researchers at a midsized public northeastern university evaluated the efficacy of a poster campaign to determine if students increase their knowledge of prosocial bystander behaviors and willingness to intervene in instances of sexual violence after viewing a series of campaign posters where student actors model appropriate bystander behaviors. During the last week of the campaign, undergraduates were invited to participate in a Web survey. The results of this preliminary evaluation indicate promising variation in the awareness of students who reported seeing the campaign compared to those who did not.

How Community and Peer Perceptions Promote College Students' Pro-Social Bystander Actions to Prevent Sexual Violence.

PubMed

Banyard, Victoria L; Rizzo, Andrew J; Bencosme, Yamilex; Cares, Alison C; Moynihan, Mary M

2018-06-01

The prevalence of sexual violence crimes on U.S. college campuses is prompting institutions of higher education to increasingly invest in centers to support survivors and programs to prevent the violence before it happens. Understanding bystanders to sexual violence and what may motivate them to step in and help is a promising prevention strategy. The purpose of this study was to understand how potential active bystanders' (first-year college students) perceptions of community (including a sense of one's influence in the community and positive peer norms for helping) and individual beliefs about self (including sense of responsibility and self-efficacy) affect their self-reports of performing bystander behavior to address sexual violence risks. Participants were 948 students at two different universities (one a rural, primarily residential campus and the other an urban, mostly commuter campus) in the northeastern United States. Regression and path analysis quantitative results suggest that individual-level characteristics may mediate some of the impact that community-level norms and perceptions have on bystander outcomes, explaining some of the mixed findings in previous research. Prevention strategies should work to change community norms and perceptions of mattering and perceptions of community influence in addition to the more traditional focus on individual-level violence specific attitudes.

Delayed innocent bystander cell death following hypoxia in Caenorhabditis elegans

PubMed Central

Sun, C-L; Kim, E; Crowder, C M

2014-01-01

After hypoxia, cells may die immediately or have a protracted course, living or dying depending on an incompletely understood set of cell autonomous and nonautonomous factors. In stroke, for example, some neurons are thought to die from direct hypoxic injury by cell autonomous primary mechanisms, whereas other so called innocent bystander neurons die from factors released from the primarily injured cells. A major limitation in identifying these factors is the inability of current in vivo models to selectively target a set of cells for hypoxic injury so that the primarily injured cells and the innocent bystanders are clearly delineated. In order to develop such a model, we generated transgenic Caenorhabditis elegans strains where 2–3% of somatic cells were made selectively sensitive to hypoxia. This was accomplished by cell type-specific wild-type rescue in either pharyngeal myocytes or GABAergic neurons of a hypoxia resistance-producing translation factor mutation. Surprisingly, hypoxic targeting of these relatively small subsets of non-essential cells produced widespread innocent bystander cell injury, behavioral dysfunction and eventual organismal death. The hypoxic injury phenotypes of the myocyte or neuron sensitized strains were virtually identical. Using this model, we show that the C. elegans insulin receptor/FOXO transcription factor pathway improves survival when activated only after hypoxic injury and blocks innocent bystander death. PMID:24317200

Delayed innocent bystander cell death following hypoxia in Caenorhabditis elegans.

PubMed

Sun, C-L; Kim, E; Crowder, C M

2014-04-01

After hypoxia, cells may die immediately or have a protracted course, living or dying depending on an incompletely understood set of cell autonomous and nonautonomous factors. In stroke, for example, some neurons are thought to die from direct hypoxic injury by cell autonomous primary mechanisms, whereas other so called innocent bystander neurons die from factors released from the primarily injured cells. A major limitation in identifying these factors is the inability of current in vivo models to selectively target a set of cells for hypoxic injury so that the primarily injured cells and the innocent bystanders are clearly delineated. In order to develop such a model, we generated transgenic Caenorhabditis elegans strains where 2-3% of somatic cells were made selectively sensitive to hypoxia. This was accomplished by cell type-specific wild-type rescue in either pharyngeal myocytes or GABAergic neurons of a hypoxia resistance-producing translation factor mutation. Surprisingly, hypoxic targeting of these relatively small subsets of non-essential cells produced widespread innocent bystander cell injury, behavioral dysfunction and eventual organismal death. The hypoxic injury phenotypes of the myocyte or neuron sensitized strains were virtually identical. Using this model, we show that the C. elegans insulin receptor/FOXO transcription factor pathway improves survival when activated only after hypoxic injury and blocks innocent bystander death.

Improvements in Modelling Bystander and Resident Exposure to Pesticide Spray Drift: Investigations into New Approaches for Characterizing the 'Collection Efficiency' of the Human Body.

PubMed

Butler Ellis, M Clare; Kennedy, Marc C; Kuster, Christian J; Alanis, Rafael; Tuck, Clive R

2018-05-28

The BREAM (Bystander and Resident Exposure Assessment Model) (Kennedy et al. in BREAM: A probabilistic bystander and resident exposure assessment model of spray drift from an agricultural boom sprayer. Comput Electron Agric 2012;88:63-71) for bystander and resident exposure to spray drift from boom sprayers has recently been incorporated into the European Food Safety Authority (EFSA) guidance for determining non-dietary exposures of humans to plant protection products. The component of BREAM, which relates airborne spray concentrations to bystander and resident dermal exposure, has been reviewed to identify whether it is possible to improve this and its description of variability captured in the model. Two approaches have been explored: a more rigorous statistical analysis of the empirical data and a semi-mechanistic model based on established studies combined with new data obtained in a wind tunnel. A statistical comparison between field data and model outputs was used to determine which approach gave the better prediction of exposures. The semi-mechanistic approach gave the better prediction of experimental data and resulted in a reduction in the proposed regulatory values for the 75th and 95th percentiles of the exposure distribution.

Gender-Equitable Attitudes, Bystander Behavior, and Recent Abuse Perpetration Against Heterosexual Dating Partners of Male High School Athletes

PubMed Central

Tancredi, Daniel J.; Silverman, Jay G.; Decker, Michele R.; Austin, S. Bryn; McCormick, Marie C.; Virata, Maria Catrina; Miller, Elizabeth

2013-01-01

Objectives. We assessed the relationship between gender attitudes, identified as a critical component of violence prevention, and abuse toward dating partners among adolescent male athletes. Methods. Our sample comprised 1699 athletes from 16 high schools in northern California who were surveyed between December 2009 and October 2010 in the larger Coaching Boys Into Men trial. We used logistic regression to assess the association between gender-equitable attitudes, bystander behavior, and recent abuse incidents. Results. Athletes with more gender-equitable attitudes and greater intention to intervene were less likely (adjusted odds ratio [AOR] = 0.36; 95% confidence interval [CI] = 0.28, 0.46; and AOR = 0.60; 95% CI = 0.48, 0.75, respectively) and athletes who engaged in negative bystander behavior were more likely (AOR = 1.22, 95% CI = 1.10, 1.35) to perpetrate abuse against their female dating partners. Conclusions. Despite the shift among bystander intervention programs toward gender neutrality, our findings suggest a strong association between gender attitudes and dating violence. Programs designed for adolescents should include discussion of gender attitudes and target bystander behavior, because these components may operate on related but distinct pathways to reduce abuse. PMID:23947324

Hooked on a feeling: affective anti-smoking messages are more effective than cognitive messages at changing implicit evaluations of smoking

PubMed Central

Smith, Colin Tucker; De Houwer, Jan

2015-01-01

Because implicit evaluations are thought to underlie many aspects of behavior, researchers have started looking for ways to change them. We examine whether and when persuasive messages alter strongly held implicit evaluations of smoking. In smokers, an affective anti-smoking message led to more negative implicit evaluations on four different implicit measures as compared to a cognitive anti-smoking message which seemed to backfire. Additional analyses suggested that the observed effects were mediated by the feelings and emotions raised by the messages. In non-smokers, both the affective and cognitive message engendered slightly more negative implicit evaluations. We conclude that persuasive messages change implicit evaluations in a way that depends on properties of the message and of the participant. Thus, our data open new avenues for research directed at tailoring persuasive messages to change implicit evaluations. PMID:26557099

Hooked on a feeling: affective anti-smoking messages are more effective than cognitive messages at changing implicit evaluations of smoking.

PubMed

Smith, Colin Tucker; De Houwer, Jan

2015-01-01

Because implicit evaluations are thought to underlie many aspects of behavior, researchers have started looking for ways to change them. We examine whether and when persuasive messages alter strongly held implicit evaluations of smoking. In smokers, an affective anti-smoking message led to more negative implicit evaluations on four different implicit measures as compared to a cognitive anti-smoking message which seemed to backfire. Additional analyses suggested that the observed effects were mediated by the feelings and emotions raised by the messages. In non-smokers, both the affective and cognitive message engendered slightly more negative implicit evaluations. We conclude that persuasive messages change implicit evaluations in a way that depends on properties of the message and of the participant. Thus, our data open new avenues for research directed at tailoring persuasive messages to change implicit evaluations.

Effects of the men's program on U.S. Army soldiers' intentions to commit and willingness to intervene to prevent rape: a pretest posttest study.

PubMed

Foubert, John D; Masin, Ryan C

2012-01-01

Noncommissioned male officers in the U.S. Army stationed in Germany were trained to present a 1-hour rape prevention workshop--The Men's Program--to 237 enlisted male soldiers. A comparison group of 244 male soldiers received a briefing focused on reducing the individual's risk for experiencing sexual assault, discussion of myths and facts about sexual assault, and how to avoid being accused of sexual assault. Participants in The Men's Program experienced significant change in the predicted direction for bystander willingness to help, bystander efficacy, rape myth acceptance, likelihood of raping, and likelihood of committing sexual assault with low to medium effect sizes. Comparison group participants experienced no effect on these variables except for a significant decline in rape myth acceptance with a very low effect size. Between-group differences pointed to the efficacy of The Men's Program. Implications of these results for rape prevention programming in the military are discussed.

I trust it, but I don't know why: effects of implicit attitudes toward automation on trust in an automated system.

PubMed

Merritt, Stephanie M; Heimbaugh, Heather; LaChapell, Jennifer; Lee, Deborah

2013-06-01

This study is the first to examine the influence of implicit attitudes toward automation on users' trust in automation. Past empirical work has examined explicit (conscious) influences on user level of trust in automation but has not yet measured implicit influences. We examine concurrent effects of explicit propensity to trust machines and implicit attitudes toward automation on trust in an automated system. We examine differential impacts of each under varying automation performance conditions (clearly good, ambiguous, clearly poor). Participants completed both a self-report measure of propensity to trust and an Implicit Association Test measuring implicit attitude toward automation, then performed an X-ray screening task. Automation performance was manipulated within-subjects by varying the number and obviousness of errors. Explicit propensity to trust and implicit attitude toward automation did not significantly correlate. When the automation's performance was ambiguous, implicit attitude significantly affected automation trust, and its relationship with propensity to trust was additive: Increments in either were related to increases in trust. When errors were obvious, a significant interaction between the implicit and explicit measures was found, with those high in both having higher trust. Implicit attitudes have important implications for automation trust. Users may not be able to accurately report why they experience a given level of trust. To understand why users trust or fail to trust automation, measurements of implicit and explicit predictors may be necessary. Furthermore, implicit attitude toward automation might be used as a lever to effectively calibrate trust.

Creating an Implicit Measure of Cognition More Suited to Applied Research: A Test of the Mixed Trial-Implicit Relational Assessment Procedure (MT-IRAP)

ERIC Educational Resources Information Center

Levin, Michael E.; Hayes, Steven C.; Waltz, Thomas

2010-01-01

The Implicit Relational Assessment Procedure (IRAP) is a promising tool for measuring implicit cognitions in applied research. However, the need for training and block effects can limit its capacity to assess effects with individual stimuli and participants, both of which are important for applied research. We developed a modified IRAP, the Mixed…

Multi-College Bystander Intervention Evaluation for Violence Prevention.

PubMed

Coker, Ann L; Bush, Heather M; Fisher, Bonnie S; Swan, Suzanne C; Williams, Corrine M; Clear, Emily R; DeGue, Sarah

2016-03-01

The 2013 Campus Sexual Violence Elimination Act requires U.S. colleges to provide bystander-based training to reduce sexual violence, but little is known about the efficacy of such programs for preventing violent behavior. This study provides the first multiyear evaluation of a bystander intervention's campus-level impact on reducing interpersonal violence victimization and perpetration behavior on college campuses. First-year students attending three similarly sized public university campuses were randomly selected and invited to complete online surveys in the spring terms of 2010-2013. On one campus, the Green Dot bystander intervention was implemented in 2008 (Intervention, n=2,979) and two comparison campuses had no bystander programming at baseline (Comparison, n=4,132). Data analyses conducted in 2014-2015 compared violence rates by condition over the four survey periods. Multivariable logistic regression was used to estimate violence risk on Intervention relative to Comparison campuses, adjusting for demographic factors and time (2010-2013). Interpersonal violence victimization rates (measured in the past academic year) were 17% lower among students attending the Intervention (46.4%) relative to Comparison (55.7%) campuses (adjusted rate ratio=0.83; 95% CI=0.79, 0.88); a similar pattern held for interpersonal violence perpetration (25.5% in Intervention; 32.2% in Comparison; adjusted rate ratio=0.79; 95% CI=0.71, 0.86). Violence rates were lower on Intervention versus Comparison campuses for unwanted sexual victimization, sexual harassment, stalking, and psychological dating violence victimization and perpetration (p<0.01). Green Dot may be an efficacious intervention to reduce violence at the community level and meet Campus Sexual Violence Elimination Act bystander training requirements. Copyright © 2016 American Journal of Preventive Medicine. All rights reserved.

Preventing Sexual Violence Through Bystander Intervention: Attitudes, Behaviors, Missed Opportunities, and Barriers to Intervention Among Australian University Students.

PubMed

Kania, Rachel; Cale, Jesse

2018-03-01

The concept of bystander intervention is gaining popularity in universities as a mechanism to prevent sexual violence. Prior research has focused on correlates of bystanders' intentions to intervene and intervention behaviors in situations where there is a risk of sexual violence. The current study builds on this literature by exploring the nature of missed opportunities, including perceived barriers to intervention. In all, 380 Australian undergraduate university students completed an online survey. Measures included a rape myth acceptance scale, bystander intentions to intervene, actual intervention behaviors, missed opportunities for intervention, and perceived barriers for missed opportunities. Promisingly, students reported high levels of intentions to intervene in situations where there was a risk of sexual violence and reported relatively few missed opportunities to do so when these situations did occur. Intervention behaviors varied by important demographic characteristics such as gender, age, attitudes toward sexual violence, and the nature of the situation. Younger female students, with lower levels of rape myth acceptance, who had previously engaged in bystander intervention behaviors were more likely to report intentions to intervene in future risky situations, and female international students reported fewer missed opportunities for intervention. The most common barrier to intervention for identified missed opportunities was a failure to recognize situations as having a potential risk for sexual violence, and students were most likely to intervene in situations when the opportunity to help a friend in distress arose. This study provides some preliminary empirical evidence about bystander intervention against sexual violence among Australian university students, and identifies unique contexts for intervention and what current barriers to intervention may be.

A Smartphone Application to Reduce the Time to Automated External Defibrillator Delivery After a Witnessed Out-of-Hospital Cardiac Arrest: A Randomized Simulation-Based Study.

PubMed

Hatakeyama, Toshihiro; Nishiyama, Chika; Shimamoto, Tomonari; Kiyohara, Kosuke; Kiguchi, Takeyuki; Chida, Izumi; Izawa, Junichi; Matsuyama, Tasuku; Kitamura, Tetsuhisa; Kawamura, Takashi; Iwami, Taku

2018-04-13

We developed a new smartphone application to deliver an automated external defibrillator (AED) to out-of-hospital cardiac arrest scene. The aim of this study was to evaluate whether an AED could be delivered earlier with or without an application in a simulated randomized controlled trial. Participants, who were asked to work as bystanders, were randomly assigned to either an application group or control group and were asked to bring an AED in both groups. The bystanders in the application group sent a signal notification using the application to two responders, who were stationed within 200 meters of the arrest scene, to carry an AED. The primary outcome was the AED delivery time by either the bystander or his/her responder. In total, 61 bystanders were eligible and randomized to either the application group (32) or the control group (29). The 52 with time data were available and analyzed. The AED delivery time by either the bystander or his/her responder was significantly shorter in the application group than in the control group [133.6 (44.4) seconds vs. 202.2 (122.2) seconds, P = 0.01]. In this simulation-based trial, AED delivery time was shortened by our newly developed smartphone application for the bystander to ask nearby responders to find and bring an AED to the cardiac arrest scene (UMIN-Clinical Trials Registry 000016506).This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

Cardiopulmonary resuscitation by trained responders versus lay persons and outcomes of out-of-hospital cardiac arrest: A community observational study.

PubMed

Park, Yoo Mi; Shin, Sang Do; Lee, Yu Jin; Song, Kyoung Jun; Ro, Young Sun; Ahn, Ki Ok

2017-09-01

The study aims to compare bystander processes of care (cardiopulmonary resuscitation (CPR) and defibrillation) and outcomes for witnessed presumed cardiac etiology in OHCA patients in whom initial resuscitation was provided by dedicated trained responder (TR) versus lay person (LP) bystanders. Data on witnessed and presumed cardiac OHCA in adults (15 years or older) from 2011 to 2015 in a metropolitan city with 10 million persons were collected, excluding cases in which the information on TRs, bystander CPR, defibrillation, and clinical outcomes was unknown. Exposure variables were TRs who were legally designated with CPR education and response and LPs who were bystanders who witnessed the OHCA by chance. The primary/secondary/tertiary outcomes were a good cerebral performance category (CPC) of 1 or 2, survival to discharge, and bystander defibrillation. A multivariable logistic regression analysis was used to calculate the adjusted odds ratio (AOR) with 95% confidence intervals (CIs), adjusting for potential confounders. Of 20,984 OHCA events, 6475 cases were ultimately analyzed. The TR group constituted 6.4% of the cases, and the patients showed significantly better survival and a good CPC. From the multivariable logistic regression analysis of the outcomes, by comparing the TR group with the LP group, the AOR (95% CIs) was 1.49 (1.04-2.15) for a good CPC, 1.59 (1.20-2.11) for survival to discharge, and 10.02 (7.04-14.26) for bystander defibrillation. The TR group witnessed a relatively low proportion of OHCA but was associated with better survival outcomes and good neurological recovery through higher CPR rates and defibrillation of adults older than 15 years with witnessed OHCA in a metropolitan city. Copyright © 2017 Elsevier B.V. All rights reserved.

Deconstructing Attitudes About Intimate Partner Violence and Bystander Intervention: The Roles of Perpetrator Gender and Severity of Aggression.

PubMed

Ermer, Ashley E; Roach, Andrea L; Coleman, Marilyn; Ganong, Lawrence

2017-10-01

In this mixed methods study, we explored how gender of an aggressor and the levels of aggression (i.e., yelling, throwing a drink, slapping, and punching) influenced attitudes about (a) public displays of intimate partner violence (IPV) and (b) bystander intervention. A feminist-informed, social constructionist perspective guided the study. Participants ( N = 562) responded online to randomly assigned factorial vignettes. Participants ranged in age between 18 and 70 years. The majority were female, self-identified as heterosexual, and identified as White. Logistic regressions revealed that participants significantly viewed aggression as unacceptable, especially in cases of more severe and male-perpetrated aggressions. Multinomial logistic regressions revealed that participants significantly thought bystanders or friends of the couple should intervene, especially in cases of male-perpetrated and/or more severe aggression. Analyses of qualitative responses indicated that participants viewed aggression as never okay, as poor communication, as justified if provoked, and discussed the gendered double standard of aggression (i.e., men should not be aggressive because they could cause more harm than females and female-perpetrated aggression is minor, in comparison). Regarding attitudes about bystander intervention, analyses of qualitative responses indicated that aggression severity, issues surrounding relationship privacy, factors relevant to the situation (e.g., if the event occurred once or repeatedly), perceptions that help was needed (e.g., if the victim was hurt), and the bystander's relationship with the victim (i.e., friend or not) were important to consider when thinking about the decision to intervene in public acts of violence. These findings have implications for bystander intervention programs and for how individuals view public acts of IPV.

Multi–College Bystander Intervention Evaluationon for Violence Prevention

PubMed Central

Coker, Ann L.; Bush, Heather M.; Fisher, Bonnie S.; Swan, Suzanne C.; Williams, Corrine M.; Clear, Emily R.; DeGue, Sarah

2015-01-01

Introduction The 2013 Campus Sexual Violence Elimination Act requires U.S. colleges to provide bystander-based training to reduce sexual violence, but little is known about the efficacy of such programs for preventing violent behavior. This study provides the first multiyear evaluation of a bystander intervention’s campus-level impact on reducing interpersonal violence victimization and perpetration behavior on college campuses. Methods First-year students attending three similarly sized public university campuses were randomly selected and invited to complete online surveys in the spring terms of 2010–2013. On one campus, the Green Dot bystander intervention had been implemented since 2008 (Intervention, n=2,979) and two Comparison campuses had no bystander programming at baseline (Comparison, n=4,132). Data analyses conducted in 2014–2015 compared violence rates by condition over the four survey periods. Multivariable logistic regression was used to estimate violence risk on Intervention relative to Comparison campuses adjusting for demographic factors and time (2010–2013). Results Interpersonal violence victimization rates (measured in the past academic year) were 17% lower among students attending the Intervention (46.4%) relative to Comparison (55.7%) campuses (adjusted rate ratio, 0.83; 95% CI=0.79, 0.88); a similar pattern held for interpersonal violence perpetration (25.5% in Intervention; 32.2% in Comparison; adjusted rate ratio, 0.79; 95% CI=0.71, 0.86). Violence rates were lower on Intervention versus Comparison campuses for unwanted sexual victimization, sexual harassment, stalking, and psychological dating violence victimization and perpetration (p<0.01). Conclusions Green Dot may be an efficacious intervention to reduce violence at the community-level and meet Campus Sexual Violence Elimination Act bystander training requirements. PMID:26541099

One-year follow-up of a coach-delivered dating violence prevention program: a cluster randomized controlled trial.

PubMed

Miller, Elizabeth; Tancredi, Daniel J; McCauley, Heather L; Decker, Michele R; Virata, Maria Catrina D; Anderson, Heather A; O'Connor, Brian; Silverman, Jay G

2013-07-01

Perpetration of physical, sexual, and psychological abuse is prevalent in adolescent relationships. One strategy for reducing such violence is to increase the likelihood that youth will intervene when they see peers engaging in disrespectful and abusive behaviors. This 12-month follow-up of a cluster RCT examined the longer-term effectiveness of Coaching Boys Into Men, a dating violence prevention program targeting high school male athletes. This cluster RCT was conducted from 2009 to 2011. The unit of randomization was the school, and the unit of analysis was the athlete. Data were analyzed in 2012. Participants were male athletes in Grades 9-11 (N=1513) participating in athletics in 16 high schools. The intervention consisted of training athletic coaches to integrate violence prevention messages into coaching activities through brief, weekly, scripted discussions with athletes. Primary outcomes were intentions to intervene, recognition of abusive behaviors, and gender-equitable attitudes. Secondary outcomes included bystander behaviors and abuse perpetration. Intervention effects were expressed as adjusted mean between-arm differences in changes in outcomes over time, estimated via regression models for clustered, longitudinal data. Perpetration of dating violence in the past 3 months was less prevalent among intervention athletes relative to control athletes, resulting in an estimated intervention effect of -0.15 (95% CI=-0.27, -0.03). Intervention athletes also reported lower levels of negative bystander behaviors (i.e., laughing and going along with peers' abusive behaviors) compared to controls (-0.41, 95% CI=-0.72, -0.10). No differences were observed in intentions to intervene (0.04, 95% CI=-0.07, 0.16); gender-equitable attitudes (-0.04, 95% CI=-0.11, 0.04); recognition of abusive behaviors (-0.03, 95% CI=-0.15, 0.09); or positive bystander behaviors (0.04, 95% CI=-0.11, 0.19). This school athletics-based dating violence prevention program is a promising approach to reduce perpetration and negative bystander behaviors that condone dating violence among male athletes. This study is registered at www.clinicaltrials.gov NCTO1367704. Copyright © 2013 American Journal of Preventive Medicine.

School Personnel's Bystander Action in Situations of Dating Violence, Sexual Violence, and Sexual Harassment Among High School Teens: A Qualitative Analysis.

PubMed

Edwards, Katie M; Rodenhizer, Kara Anne; Eckstein, Robert P

2017-04-01

We examined school personnel's engagement in bystander action in situations of teen dating violence (DV), sexual violence (SV), and sexual harassment (SH). We conducted focus groups with 22 school personnel from three high schools in New Hampshire. School personnel identified their own barriers to intervening in situations of teen DV, SV, and SH (e.g., not having the time or ability to intervene). School personnel also discussed the ways in which they intervened before (e.g., talking with teens about healthy relationships), during (e.g., breaking up fights between dating partners) and after (e.g., comforting victims) instances of teen DV, SV, and SH. These data can be used to support the development of bystander training for school personnel as one component of comprehensive DV, SV, and SH prevention for teens. In addition, these data provide information that can be used to develop measures that assess school personnel bystander action barriers and behaviors in instances of teen DV, SV, and SH.

The 4Rs of Aquatic Rescue: educating the public about safety and risks of bystander rescue.

PubMed

Moran, Kevin; Webber, Jonathon; Stanley, Teresa

2017-09-01

From 1980 to 2014, 87 persons drowned in New Zealand while attempting to rescue others; all incidents occurred in open water and most (80%) fatalities were male. While bystander rescue has been promoted as a way of preventing drowning, little is known about the knowledge base that informs potential rescuers. This study utilized a family water safety programme to promote a resource entitled the 4Rs of Aquatic Rescue. Participants (n = 174) completed a pre-intervention survey and were then provided with information and access to electronic resources on safe bystander rescue techniques. Most respondents (71%) had never been taught rescue techniques, and males were more confident of their rescue ability. Upon completion of the programme, significant differences were evident in respondents' understanding of rescue safety, but this did not translate to greater confidence or disposition towards performing a rescue. Ways of promoting bystander safety around water are discussed and recommendations for future studies are made.

Predicting bystander intervention among middle school students.

PubMed

Menolascino, Nicole; Jenkins, Lyndsay N

2018-06-01

Bullying is a prevalent issue in schools, and the importance of involving bystanders in bullying prevention has been recognized; however, there are few studies that examine personal characteristics that relate to the five steps of Latané and Darley's (1970) Bystander Intervention Model (notice the event, interpret as an emergency, accept responsibility, know what to do, and act). This study examined cognitive and affective empathy and perceived popularity and their relation to each of the five steps of the Bystander Intervention Model in Bullying (Nickerson, Aloe, Livingston, & Feeley, 2014), as well as explored if gender changed those relations. With a sample of 346 sixth to eighth grade students, we found a negative relation between perceived popularity and noticing bullying events. For boys, higher affective empathy was associated with a greater likelihood of interpreting bullying as an emergency and accepting responsibility for intervening, but for girls, their perception of bullying as an emergency and accepting responsibility was stable regardless of their level of affective empathy. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Effects of very low fluences of high-energy protons or iron ions on irradiated and bystander cells.

PubMed

Yang, H; Magpayo, N; Rusek, A; Chiang, I-H; Sivertz, M; Held, K D

2011-12-01

In space, astronauts are exposed to radiation fields consisting of energetic protons and high atomic number, high-energy (HZE) particles at very low dose rates or fluences. Under these conditions, it is likely that, in addition to cells in an astronaut's body being traversed by ionizing radiation particles, unirradiated cells can also receive intercellular bystander signals from irradiated cells. Thus this study was designed to determine the dependence of DNA damage induction on dose at very low fluences of charged particles. Novel techniques to quantify particle fluence have been developed at the NASA Space Radiation Biology Laboratory (NSRL) at Brookhaven National Laboratory (BNL). The approach uses a large ionization chamber to visualize the radiation beam coupled with a scintillation counter to measure fluence. This development has allowed us to irradiate cells with 1 GeV/nucleon protons and iron ions at particle fluences as low as 200 particles/cm(2) and quantify biological responses. Our results show an increased fraction of cells with DNA damage in both the irradiated population and bystander cells sharing medium with irradiated cells after low fluences. The fraction of cells with damage, manifest as micronucleus formation and 53BP1 focus induction, is about 2-fold higher than background at doses as low as ∼0.47 mGy iron ions (∼0.02 iron ions/cell) or ∼70 μGy protons (∼2 protons/cell). In the irradiated population, irrespective of radiation type, the fraction of damaged cells is constant from the lowest damaging fluence to about 1 cGy, above which the fraction of damaged cells increases with dose. In the bystander population, the level of damage is the same as in the irradiated population up to 1 cGy, but it does not increase above that plateau level with increasing dose. The data suggest that at fluences of high-energy protons or iron ions less than about 5 cGy, the response in irradiated cell populations may be dominated by the bystander response.

Controlled and implicit processes in evaluative conditioning on implicit and explicit attitudes toward alcohol and intentions to drink.

PubMed

Zerhouni, Oulmann; Bègue, Laurent; Comiran, Francisco; Wiers, Reinout W

2018-01-01

Since implicit attitudes (i.e. evaluations occurring outside of complete awareness) are highly predictive of alcohol consumption, we tested an evaluative learning procedure based on repeated pairing to a critical stimulus (i.e. alcohol, the CS) with a valenced stimulus (the US) in order to modify implicit attitudes (i.e. evaluative conditioning; EC). We hypothesized that manipulating the learning context to bolster implicit affect misattribution should strengthen EC effects on implicit attitudes toward alcohol, while encouraging deliberate processing of CS-US pairs, should strengthen EC effects on explicit attitudes. In our study (n=114 students) we manipulated whether CS-US pairs were presented simultaneously or sequentially. Recollective memory was estimated with a Process Dissociation Procedure. Both implicit and explicit attitudes were assessed immediately after the procedure. Behavioral intentions were measured directly after and one week after the EC-procedure. We found that EC with sequential presentation had a stronger impact on implicit and explicit measures and on purchase intentions immediately after the procedure and one week after. The present findings provide new evidence that (i) EC is an effective way to change implicit attitudes toward alcohol and (ii) evidence that EC may be better described by propositional rather than dual process accounts. Copyright © 2017 Elsevier Ltd. All rights reserved.

People, clothing, music, and arousal as contextual retrieval cues in verbal memory.

PubMed

Standing, Lionel G; Bobbitt, Kristin E; Boisvert, Kathryn L; Dayholos, Kathy N; Gagnon, Anne M

2008-10-01

Four experiments (N = 164) on context-dependent memory were performed to explore the effects on verbal memory of incidental cues during the test session which replicated specific features of the learning session. These features involved (1) bystanders, (2) the clothing of the experimenter, (3) background music, and (4) the arousal level of the subject. Social contextual cues (bystanders or experimenter clothing) improved verbal recall or recognition. However, recall decreased when the contextual cue was a different stimulus taken from the same conceptual category (piano music by Chopin) that was heard during learning. Memory was unaffected by congruent internal cues, produced by the same physiological arousal level (low, moderate, or high heart rate) during the learning and test sessions. However, recall increased with the level of arousal across the three congruent conditions. The results emphasize the effectiveness as retrieval cues of stimuli which are socially salient, concrete, and external.

The Bystander Approach to Sexual Assault Risk Reduction: Effects on Risk Recognition, Perceived Self-Efficacy, and Protective Behavior.

PubMed

Bannon, R Sean; Foubert, John D

2017-02-01

Several characteristics of sexual assault awareness programs for women are associated with meeting the goals of risk reduction. To date, the literature lacks an exploration of how single-sex programs affect women, particularly when they take a bystander intervention focus using women's risk recognition and avoidance as outcome measures. The purpose of this study was to investigate the effectiveness of The Women's Program (Foubert, 2011), a sexual assault awareness program geared toward women. Participants consisted of 103 undergraduate women attending a large, public university in the Midwest United States. Women in the treatment group viewed a presentation of The Women's Program, whereas the control group received no intervention. Consistent with hypotheses, program participants reported a greater ability to recognize risk cues, a greater willingness to engage in self-protective behaviors, and a greater level of perceived self-efficacy in handling threatening dating situations compared to the control group.

The future impacts of non-targeted effects.

PubMed

Bright, Scott; Kadhim, Munira

2018-04-11

Ionizing radiation was traditionally thought to exert its detrimental effects through interaction with sensitive cellular targets, nuclear DNA being of most importance. This theory has since merged with a more recently described radiation response called non-targeted effects (NTE). This review will briefly look at the various types of NTE and the potential implications they may have for radiobiology research and its applications. The most well-known NTE are genomic instability (GI) and bystander effects (BE). Other NTE include abscopal effects, which are similar to bystander effects but are generally based in a clinical environment with immune involvement as the defining feature. Currently, our understanding of NTE is limited to certain signaling pathways/molecules, and as yet there is no theory that describes or can accurately predict the occurrence or outcome of these NTE. There are numerous groups investigating these processes in vitro and in vivo, and thus steady progress is being made. Developing a deeper understanding of NTE has potential impacts for therapy and diagnosis, safer occupational exposures, space flight and our general understanding of radiation biology.

Incoming College Students' Bystander Behaviors to Prevent Sexual Violence

ERIC Educational Resources Information Center

McMahon, Sarah; Banyard, Victoria L.; McMahon, Sheila M.

2015-01-01

Evaluations of bystander intervention education programs demonstrate that this approach results in students' increased willingness to intervene in prosocial ways to prevent sexual violence (e.g., Moynihan, Banyard, Arnold, Eckstein, & Stapleton, 2010). These programs often focus on first-year college students, though theories and research on…

Implicit Motives and Men’s Perceived Constraint in Fatherhood

PubMed Central

Ruppen, Jessica; Waldvogel, Patricia; Ehlert, Ulrike

2016-01-01

Research shows that implicit motives influence social relationships. However, little is known about their role in fatherhood and, particularly, how men experience their paternal role. Therefore, this study examined the association of implicit motives and fathers’ perceived constraint due to fatherhood. Furthermore, we explored their relation to fathers’ life satisfaction. Participants were fathers with biological children (N = 276). They were asked to write picture stories, which were then coded for implicit affiliation and power motives. Perceived constraint and life satisfaction were assessed on a visual analog scale. A higher implicit need for affiliation was significantly associated with lower perceived constraint, whereas the implicit need for power had the opposite effect. Perceived constraint had a negative influence on life satisfaction. Structural equation modeling revealed significant indirect effects of implicit affiliation and power motives on life satisfaction mediated by perceived constraint. Our findings indicate that men with a higher implicit need for affiliation experience less constraint due to fatherhood, resulting in higher life satisfaction. The implicit need for power, however, results in more perceived constraint and is related to decreased life satisfaction. PMID:27933023

Validity for an integrated laboratory analogue of sexual aggression and bystander intervention.

PubMed

Parrott, Dominic J; Tharp, Andra Teten; Swartout, Kevin M; Miller, Cameron A; Hall, Gordon C Nagayama; George, William H

2012-01-01

This study sought to develop and validate an integrated laboratory paradigm of sexual aggression and bystander intervention. Participants were a diverse community sample (54% African American) of heterosexual males (N = 156) between 21 and 35 years of age who were recruited to complete the study with a male friend and an ostensibly single, heterosexual female who reported a strong dislike of sexual content in the media. Participants viewed a sexually explicit or nonsexually explicit film clip as part of contrived media rating task and made individual choices of which film clip to show the female confederate. Immediately thereafter, participants were required to reach consensus on a group decision of which film clip to show the female confederate. Subjecting a target to an unwanted experience with a sexual connotation was operationalized as selection of the sexually explicit video, whereas successful bystander intervention was operationalized as the event of one partner individually selecting the sexually explicit video but then selecting the nonsexually explicit video for the group choice. Results demonstrated that a 1-year history of sexual aggression and endorsement of pertinent misogynistic attitudes significantly predicted selection of the sexually-explicit video. In addition, bystander efficacy significantly predicted men's successful prevention of their male peer's intent to show the female confederate a sexually explicit video. Discussion focused on how these data inform future research and bystander intervention programming for sexual aggression. © 2012 Wiley Periodicals, Inc.

The Locus of Implicit Causality Effects in Comprehension

PubMed Central

Garnham, Alan; Traxler, Matthew; Oakhill, Jane; Gernsbacher, Morton Ann

2015-01-01

Implicit causality might enable readers to focus on the imputed cause of an event and make it the default referent of a following pronoun. Alternatively, its effects might arise only when a following explicit cause is integrated with a description of the event. In three probe recognition experiments, in which the participants in the events were of the same sex, the only reliable effect — apart from the advantage of first mention — was that of whether implicit and explicit causes were the same. This effect was independent of whether the probe named the referent of the pronoun. In a fourth experiment, in which the two participants were of different sexes, there was no simple effect of implicit causality, but there was an advantage for the pronoun’s referent. These results are consistent with the view that implicit causality has its effects at integration. We discuss their broader implications for theories of comprehension. PMID:26221059

Investigating the predictive validity of implicit and explicit measures of motivation on condom use, physical activity and healthy eating.

PubMed

Keatley, David; Clarke, David D; Hagger, Martin S

2012-01-01

The literature on health-related behaviours and motivation is replete with research involving explicit processes and their relations with intentions and behaviour. Recently, interest has been focused on the impact of implicit processes and measures on health-related behaviours. Dual-systems models have been proposed to provide a framework for understanding the effects of explicit or deliberative and implicit or impulsive processes on health behaviours. Informed by a dual-systems approach and self-determination theory, the aim of this study was to test the effects of implicit and explicit motivation on three health-related behaviours in a sample of undergraduate students (N = 162). Implicit motives were hypothesised to predict behaviour independent of intentions while explicit motives would be mediated by intentions. Regression analyses indicated that implicit motivation predicted physical activity behaviour only. Across all behaviours, intention mediated the effects of explicit motivational variables from self-determination theory. This study provides limited support for dual-systems models and the role of implicit motivation in the prediction of health-related behaviour. Suggestions for future research into the role of implicit processes in motivation are outlined.

Investigating the predictive validity of implicit and explicit measures of motivation in problem-solving behavioural tasks.

PubMed

Keatley, David; Clarke, David D; Hagger, Martin S

2013-09-01

Research into the effects of individuals'autonomous motivation on behaviour has traditionally adopted explicit measures and self-reported outcome assessment. Recently, there has been increased interest in the effects of implicit motivational processes underlying behaviour from a self-determination theory (SDT) perspective. The aim of the present research was to provide support for the predictive validity of an implicit measure of autonomous motivation on behavioural persistence on two objectively measurable tasks. SDT and a dual-systems model were adopted as frameworks to explain the unique effects offered by explicit and implicit autonomous motivational constructs on behavioural persistence. In both studies, implicit autonomous motivation significantly predicted unique variance in time spent on each task. Several explicit measures of autonomous motivation also significantly predicted persistence. Results provide support for the proposed model and the inclusion of implicit measures in research on motivated behaviour. In addition, implicit measures of autonomous motivation appear to be better suited to explaining variance in behaviours that are more spontaneous or unplanned. Future implications for research examining implicit motivation from dual-systems models and SDT approaches are outlined. © 2012 The British Psychological Society.

Bonobos respond to distress in others: consolation across the age spectrum.

PubMed

Clay, Zanna; de Waal, Frans B M

2013-01-01

How animals respond to conflict provides key insights into the evolution of socio-cognitive and emotional capacities. Evidence from apes has shown that, after social conflicts, bystanders approach victims of aggression to offer stress-alleviating contact behavior, a phenomenon known as consolation. This other-orientated behavior depends on sensitivity to the other's emotional state, whereby the consoler acts to ameliorate the other's situation. We examined post-conflict interactions in bonobos (Pan paniscus) to identify the determinants of consolation and reconciliation. Thirty-six semi-free bonobos of all ages were observed at the Lola ya Bonobo Sanctuary, DR Congo, using standardized Post-conflict/Matched Control methods. Across age and sex classes, bonobos consoled victims and reconciled after conflicts using a suite of affiliative and socio-sexual behaviors including embracing, touching, and mounting. Juveniles were more likely to console than adults, challenging the assumption that comfort-giving rests on advanced cognitive mechanisms that emerge only with age. Mother-reared individuals were more likely to console than orphans, highlighting the role of rearing in emotional development. Consistent with previous studies, bystanders were more likely to console relatives or closely bonded partners. Effects of kinship, affiliation and rearing were similarly indicated in patterns of reconciliation. Nearby bystanders were significantly more likely to contact victims than more distal ones, and consolation was more likely in non-food contexts than during feeding. The results did not provide convincing evidence that bystander contacts served for self-protection or as substitutes for reconciliation. Overall, results indicate that a suite of social, developmental and contextual factors underlie consolation and reconciliation in bonobos and that a sensitivity to the emotions of others and the ability to provide appropriate consolatory behaviors emerges early in development.

The importance of serum serotonin levels in the measurement of radiation-induced bystander cell death in HaCaT cells.

PubMed

Lyng, Fiona M; Desplanques, Maxime; Jella, Kishore Kumar; Garcia, Amaya; McClean, Brendan

2012-10-01

The aim of this study was to investigate the importance of serum serotonin levels in the measurement of bystander cell death. The study was undertaken as part of an intercomparison exercise involving seven European laboratories funded under the European Union Sixth Framework Programme (FP6) Non-Targeted Effects (NOTE) integrated project. Three batches of foetal bovine serum were tested; serum with high and low serotonin content from the intercomparison exercise as well as serum from the home laboratory. Three sets of human keratinocytes (HaCaT cell line) were cultured in DMEM:F12 medium supplemented with serum with high or low serotonin content or serum from the home laboratory and both donor and recipient HaCaT cells were plated. The donor HaCaT cells were irradiated (0.5 Gy) using a cobalt 60 teletherapy unit, the medium was harvested 1 hour post irradiation and transferred to the recipient HaCaT cells. Bystander induced cell death was measured by the clonogenic survival assay and the Alamar blue viability assay. A significant reduction in cell survival, as measured by the clonogenic assay, and in cell viability, as measured by the Alamar blue assay, was observed in the recipient HaCaT cells treated with medium from irradiated cells compared to the cells treated with medium from unirradiated cells. No significant difference was found between the three batches of serum. The data suggest that in our cell system and with our endpoints (clonogenic assay and Alamar blue assay), serum serotonin levels do not play a role in bystander-induced cell death.

Bystander cardiopulmonary resuscitation training experience and self-efficacy of age and gender group: a nationwide community survey.

PubMed

Ro, Young Sun; Shin, Sang Do; Song, Kyoung Jun; Hong, Sung Ok; Kim, Young Taek; Cho, Sung-Il

2016-08-01

We hypothesized that recent hands-on practice for cardiopulmonary resuscitation (CPR) would be strongly associated with a higher likelihood of self-efficacy in bystander CPR among laypersons according to age and gender group. We used the National Korean Community Health Survey database of 228921 representatively sampled responders from 253 counties in 2012. Laypersons who had previous CPR training were eligible. Exposure variables were having had CPR training with hands-on practice session with a manikin (Practical-CPR-Training) and CPR training within the last 2 years (Recent-CPR-Training). Primary outcome was self-efficacy in bystander CPR. Multivariable logistic regression analysis was performed. The final model with an interaction term was evaluated to compare the effects of CPR training across different age and gender groups. Of 62425 eligible respondents who have had CPR training, 20213 (32.4%) had Practical-CPR-Training. Adjusted odds ratios (AORs) for self-efficacy were 4.08 (3.78-4.41) in Practical-CPR-Training, 2.61 (2.50-2.73) in male, 1.26 (1.16-1.36) in good self-rated health, 1.19 (1.10-1.29) in high school graduate, 1.19 (1.01-1.39) in persons living with stroke patients in household, and 1.17 (1.10-1.24) in Recent-CPR-Training. In interaction models, Practical-CPR-Training showed higher self-efficacy in all age and gender groups, whereas Recent-CPR-Training was not associated with better self-efficacy in elderly group, male (AOR, 0.90 [0.69-1.18]) and female (AOR, 0.94 [0.72-1.23]). Self-efficacy in bystander CPR was higher in person with recent CPR training with hands-on practice with a manikin. Copyright © 2015 Elsevier Inc. All rights reserved.

Implementation of the ALERT algorithm, a new dispatcher-assisted telephone cardiopulmonary resuscitation protocol, in non-Advanced Medical Priority Dispatch System (AMPDS) Emergency Medical Services centres.

PubMed

Stipulante, Samuel; Tubes, Rebecca; El Fassi, Mehdi; Donneau, Anne-Francoise; Van Troyen, Barbara; Hartstein, Gary; D'Orio, Vincent; Ghuysen, Alexandre

2014-02-01

Early bystander cardiopulmonary resuscitation (CPR) is a key factor in improving survival from out-of-hospital cardiac arrest (OHCA). The ALERT (Algorithme Liégeois d'Encadrement à la Réanimation par Téléphone) algorithm has the potential to help bystanders initiate CPR. This study evaluates the effectiveness of the implementation of this protocol in a non-Advanced Medical Priority Dispatch System area. We designed a before and after study based on a 3-month retrospective assessment of victims of OHCA in 2009, before the implementation of the ALERT protocol in Liege emergency medical communication centre (EMCC), and the prospective evaluation of the same 3 months in 2011, immediately after the implementation. At the moment of the call, dispatchers were able to identify 233 OHCA in the first period and 235 in the second. Victims were predominantly male (59%, both periods), with mean ages of 64.1 and 63.9 years, respectively. In 2009, only 9.9% victims benefited from bystander CPR, this increased to 22.5% in 2011 (p<0.0002). The main reasons for protocol under-utilisation were: assistance not offered by the dispatcher (42.3%), caller physically remote from the victim (20.6%). Median time from call to first compression, defined here as no flow time, was 253s in 2009 and 168s in 2011 (NS). Ten victims were admitted to hospital after ROSC in 2009 and 13 in 2011 (p=0.09). From the beginning and despite its under-utilisation, the ALERT protocol significantly improved the number of patients in whom bystander CPR was attempted. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Implicit Social Biases in People with Autism

PubMed Central

Birmingham, Elina; Stanley, Damian; Nair, Remya; Adolphs, Ralph

2015-01-01

Implicit social biases are ubiquitous and are known to influence social behavior. A core diagnostic criterion of Autism Spectrum Disorder (ASD) is abnormal social behavior. Here we investigated the extent to which individuals with ASD might show a specific attenuation of implicit social biases, using the Implicit Association Test (IAT) across Social (gender, race) and Nonsocial (flowers/insect, shoes) categories. High-functioning adults with ASD showed intact but reduced IAT effects relative to healthy controls. Importantly, we observed no selective attenuation of implicit social (vs. nonsocial) biases in our ASD population. To extend these results, we collected data from a large online sample of the general population, and explored correlations between autistic traits and IAT effects. No associations were found between autistic traits and IAT effects for any of the categories tested in our online sample. Taken together, these results suggest that implicit social biases, as measured by the IAT, are largely intact in ASD. PMID:26386014

Using Bullying Incident Density to Evaluate the Olweus Bullying Prevention Programme

ERIC Educational Resources Information Center

Black, Sally A.; Jackson, Ericka

2007-01-01

Bullying negatively impacts the mental and physical health of student victims, bullies and bystanders. The Olweus Bullying Prevention Programme is an internationally recognized school based programme demonstrated effective in research. The purpose of this study was to determine if the Bullying Prevention Programme was effective for urban youth…

BYSTANDERS, ADAPTIVE RESPONSES AND GENOMIC INSTABILITY - POTENTIAL MODIFIERS OF LOW-DOSE CANCER RESPONSES.

EPA Science Inventory

Bystanders, Adaptive Responses and Genomic Instability -Potential Modifiers ofLow-Dose
Cancer Responses
.
There has been a concerted effort in the field of radiation biology to better understand cellular
responses that could have an impact on the estin1ation of cancer...

Exploring the Impact of Bullying on Young Bystanders

ERIC Educational Resources Information Center

Hutchinson, Matthew

2012-01-01

This study aimed to explore peer bullying events in schools by using Interpretative Phenomenological Analysis (IPA) to consider the experiences of young bystanders: the perceptions and understandings of students who had witnessed bullying. Participants were aged 12-13 and attended two neighbouring secondary schools in the UK. Four themes were…

32 CFR 632.5 - Use of firearms.

Code of Federal Regulations, 2010 CFR

2010-07-01

... not fire if shots are likely to harm innocent bystanders. (3) Since warning shots could harm innocent bystanders, avoid firing them. However, when lesser degrees of force have failed, the law enforcement or.... If able to avoid hazards to innocent persons in these cases, fire warning shots. (4) Aim to disable...

Aggressive Attitudes and Prevalence of Bullying Bystander Behavior in Middle School

ERIC Educational Resources Information Center

Datta, Pooja; Cornell, Dewey; Huang, Francis

2016-01-01

Separate lines of research find that proaggressive attitudes promote peer aggression and that bystanders play a pivotal role in deterring or facilitating bullying behavior. The current study hypothesized that proaggressive attitudes in middle school would deter students from standing up to bullying and encourage them to reinforce bullying…

Being a Positive Bystander: Male Antiviolence Allies' Experiences of "Stepping up"

ERIC Educational Resources Information Center

Casey, Erin A.; Ohler, Kristin

2012-01-01

As bystander approaches become increasingly prevalent elements of sexual and domestic violence prevention efforts, it is necessary to better understand the factors that support or impede individuals in taking positive action in the face of aggressive or disrespectful behavior from others. This study presents descriptive findings about the…

R.U. Ready?: Peer Education and Bystander Intervention Sexual Assault Programming

ERIC Educational Resources Information Center

Schweer, Jen Luettel; Heather, Katie; Kay, Kathryn; Stewart, K. Leigh; Kovach, Laura

2012-01-01

R.U. Ready? at Georgetown University is an annual sexual assault awareness event that incorporates peer education and resources with opportunities for students, staff, and faculty to dialogue about providing bystander intervention throughout the campus community. Beyond dialogue, participants learn about student activism and the resources and…

Bystanders' Supportive and Passive Responses to Cyberaggression

ERIC Educational Resources Information Center

Machackova, Hana; Dedkova, Lenka; Sevcikova, Anna; Cerna, Alena

2018-01-01

Bystanders in cyberaggression can support the victim, join the aggressor, or remain passive. We examined how supportive and passive adolescent Czech cyberbystanders (N = 443, ages 12-18) differ in terms of individual characteristics, emotional responses, and contextual factors. The most substantial distinguishing factor between the two groups…

Terror management theory and self-esteem revisited: the roles of implicit and explicit self-esteem in mortality salience effects.

PubMed

Schmeichel, Brandon J; Gailliot, Matthew T; Filardo, Emily-Ana; McGregor, Ian; Gitter, Seth; Baumeister, Roy F

2009-05-01

Three studies tested the roles of implicit and/or explicit self-esteem in reactions to mortality salience. In Study 1, writing about death versus a control topic increased worldview defense among participants low in implicit self-esteem but not among those high in implicit self-esteem. In Study 2, a manipulation to boost implicit self-esteem reduced the effect of mortality salience on worldview defense. In Study 3, mortality salience increased the endorsement of positive personality descriptions but only among participants with the combination of low implicit and high explicit self-esteem. These findings indicate that high implicit self-esteem confers resilience against the psychological threat of death, and therefore the findings provide direct support for a fundamental tenet of terror management theory regarding the anxiety-buffering role of self-esteem. Copyright (c) 2009 APA, all rights reserved.

Action of methotrexate and tofacitinib on directly stimulated and bystander-activated lymphocytes.

PubMed

Piscianz, Elisa; Candilera, Vanessa; Valencic, Erica; Loganes, Claudia; Paron, Greta; De Iudicibus, Sara; Decorti, Giuliana; Tommasini, Alberto

2016-07-01

Chronic inflammation associated with autoimmune activation is characteristic of rheumatic diseases from childhood to adulthood. In recent decades, significant improvements in the treatment of these types of disease have been achieved using disease modifying anti-rheumatic drugs (DMARDs), such as methotrexate (MTX) and, more recently, using biologic inhibitors. The recent introduction of kinase inhibitors (for example, tofacitinib; Tofa) further increases the available ARDs. However, there are patients that do not respond to any treatment strategies, for whom combination therapies are proposed. The data regarding the combined action of different drugs is lacking and the knowledge of the mechanisms of ARDs and their actions upon pathogenic lymphocytes, which are hypothesized to sustain disease, is poor. An in vitro model of inflammation was developed in the current study, in which stimulated and unstimulated lymphocytes were cultured together, but tracked separately, to investigate the action of MTX and Tofa on the two populations. By analysing lymphocyte proliferation and activation, and cytokine secretion in the culture supernatants, it was established that, due to the presence of activated cells, unstimulated cells underwent a bystander activation that was modulated by the ARDs. Additionally, varying administration schedules were demonstrated to affect lymphocytes differently in vitro, either directly or via bystander activation. Furthermore, MTX and Tofa exerted different effects; while MTX showed an antiproliferative effect, Tofa marginally effected activation, although only a slight antiproliferative action, which could be potentiated by sequential treatment with MTX. Thus, it was hypothesized that these differences may be exploited in sequential therapeutic strategies, to maximize the anti‑rheumatic effect. These findings are notable and must be accounted for, as bystander‑activated cells in vivo could contribute to the spread of autoimmune activation and disease progression.

Trial Watch: Anticancer radioimmunotherapy.

PubMed

Vacchelli, Erika; Vitale, Ilio; Tartour, Eric; Eggermont, Alexander; Sautès-Fridman, Catherine; Galon, Jérôme; Zitvogel, Laurence; Kroemer, Guido; Galluzzi, Lorenzo

2013-09-01

Radiotherapy has extensively been employed as a curative or palliative intervention against cancer throughout the last century, with a varying degree of success. For a long time, the antineoplastic activity of X- and γ-rays was entirely ascribed to their capacity of damaging macromolecules, in particular DNA, and hence triggering the (apoptotic) demise of malignant cells. However, accumulating evidence indicates that (at least part of) the clinical potential of radiotherapy stems from cancer cell-extrinsic mechanisms, including the normalization of tumor vasculature as well as short- and long-range bystander effects. Local bystander effects involve either the direct transmission of lethal signals between cells connected by gap junctions or the production of diffusible cytotoxic mediators, including reactive oxygen species, nitric oxide and cytokines. Conversely, long-range bystander effects, also known as out-of-field or abscopal effects, presumably reflect the elicitation of tumor-specific adaptive immune responses. Ionizing rays have indeed been shown to promote the immunogenic demise of malignant cells, a process that relies on the spatiotemporally defined emanation of specific damage-associated molecular patterns (DAMPs). Thus, irradiation reportedly improves the clinical efficacy of other treatment modalities such as surgery (both in neo-adjuvant and adjuvant settings) or chemotherapy. Moreover, at least under some circumstances, radiotherapy may potentiate anticancer immune responses as elicited by various immunotherapeutic agents, including (but presumably not limited to) immunomodulatory monoclonal antibodies, cancer-specific vaccines, dendritic cell-based interventions and Toll-like receptor agonists. Here, we review the rationale of using radiotherapy, alone or combined with immunomodulatory agents, as a means to elicit or boost anticancer immune responses, and present recent clinical trials investigating the therapeutic potential of this approach in cancer patients.

Trial Watch

PubMed Central

Vacchelli, Erika; Vitale, Ilio; Tartour, Eric; Eggermont, Alexander; Sautès-Fridman, Catherine; Galon, Jérôme; Zitvogel, Laurence; Kroemer, Guido; Galluzzi, Lorenzo

2013-01-01

Radiotherapy has extensively been employed as a curative or palliative intervention against cancer throughout the last century, with a varying degree of success. For a long time, the antineoplastic activity of X- and γ-rays was entirely ascribed to their capacity of damaging macromolecules, in particular DNA, and hence triggering the (apoptotic) demise of malignant cells. However, accumulating evidence indicates that (at least part of) the clinical potential of radiotherapy stems from cancer cell-extrinsic mechanisms, including the normalization of tumor vasculature as well as short- and long-range bystander effects. Local bystander effects involve either the direct transmission of lethal signals between cells connected by gap junctions or the production of diffusible cytotoxic mediators, including reactive oxygen species, nitric oxide and cytokines. Conversely, long-range bystander effects, also known as out-of-field or abscopal effects, presumably reflect the elicitation of tumor-specific adaptive immune responses. Ionizing rays have indeed been shown to promote the immunogenic demise of malignant cells, a process that relies on the spatiotemporally defined emanation of specific damage-associated molecular patterns (DAMPs). Thus, irradiation reportedly improves the clinical efficacy of other treatment modalities such as surgery (both in neo-adjuvant and adjuvant settings) or chemotherapy. Moreover, at least under some circumstances, radiotherapy may potentiate anticancer immune responses as elicited by various immunotherapeutic agents, including (but presumably not limited to) immunomodulatory monoclonal antibodies, cancer-specific vaccines, dendritic cell-based interventions and Toll-like receptor agonists. Here, we review the rationale of using radiotherapy, alone or combined with immunomodulatory agents, as a means to elicit or boost anticancer immune responses, and present recent clinical trials investigating the therapeutic potential of this approach in cancer patients. PMID:24319634

Gata3 hypermethylation and Foxp3 hypomethylation are associated with sustained protection and bystander effect following epicutaneous immunotherapy in peanut-sensitized mice.

PubMed

Mondoulet, Lucie; Dioszeghy, Vincent; Busato, Florence; Plaquet, Camille; Dhelft, Véronique; Bethune, Kevin; Leclere, Laurence; Daviaud, Christian; Ligouis, Mélanie; Sampson, Hugh; Dupont, Christophe; Tost, Jörg

2018-05-19

Epicutaneous immunotherapy (EPIT) is a promising method for treating food allergies. In animal models, EPIT induces sustained unresponsiveness and prevents further sensitization mediated by Tregs. Here, we elucidate the mechanisms underlying the therapeutic effect of EPIT, by characterizing the kinetics of DNA methylation changes in sorted cells from spleen and blood and by evaluating its persistence and bystander effect compared to oral immunotherapy (OIT). BALB/c mice orally sensitized to peanut proteins (PPE) were treated by EPIT using a PPE-patch or by PPE-OIT. Another set of peanut-sensitized mice treated by EPIT or OIT were sacrificed following a protocol of sensitization to OVA. DNA methylation was analysed during immunotherapy and 8 weeks after the end of treatment in sorted cells from spleen and blood by pyrosequencing. Humoral and cellular responses were measured during and after immunotherapy. Analyses showed a significant hypermethylation of the Gata3 promoter detectable only in Th2 cells for EPIT from the 4 th week and a significant hypomethylation of the Foxp3 promoter in CD62L + Tregs, which was sustained only for EPIT. In addition, mice treated with EPIT were protected from subsequent sensitization and maintained the epigenetic signature characteristic for EPIT. Our study demonstrates that EPIT leads to a unique and stable epigenetic signature in specific T cell compartments with down regulation of Th2 key regulators and upregulation of Treg transcription factors, likely explaining the sustainability of protection and the observed bystander effect. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The Effect of Implicit Preferences on Food Consumption: Moderating Role of Ego Depletion and Impulsivity

PubMed Central

Wang, Yan; Zhu, Jinglei; Hu, Yi; Fang, Yuan; Wang, Guosen; Cui, Xianghua; Wang, Lei

2016-01-01

Ego depletion has been found to moderate the effect of implicit preferences on food consumption, such that implicit preferences predict consumption only under a depleted state. The present study tested how trait impulsivity impacts the effect of implicit preferences on food consumption in a depleted condition. Trait impulsivity was measured by means of self-report and a stop signal task. Results showed that both self-reported impulsivity and behavioral impulsivity moderated the ‘depletion and then eating according to implicit preferences’ effect, albeit in different ways. Participants high in self-reported impulsivity and low in behavioral impulsivity were more vulnerable to the effect of depletion on eating. The implications of these results for extant theories are discussed. Future research is needed to verify whether or not trait impulsivity is associated with vulnerability to depletion across different self-control domains. PMID:27881966

Intrusive effects of implicitly processed information on explicit memory.

PubMed

Sentz, Dustin F; Kirkhart, Matthew W; LoPresto, Charles; Sobelman, Steven

2002-02-01

This study described the interference of implicitly processed information on the memory for explicitly processed information. Participants studied a list of words either auditorily or visually under instructions to remember the words (explicit study). They were then visually presented another word list under instructions which facilitate implicit but not explicit processing. Following a distractor task, memory for the explicit study list was tested with either a visual or auditory recognition task that included new words, words from the explicit study list, and words implicitly processed. Analysis indicated participants both failed to recognize words from the explicit study list and falsely recognized words that were implicitly processed as originating from the explicit study list. However, this effect only occurred when the testing modality was visual, thereby matching the modality for the implicitly processed information, regardless of the modality of the explicit study list. This "modality effect" for explicit memory was interpreted as poor source memory for implicitly processed information and in light of the procedures used. as well as illustrating an example of "remembering causing forgetting."

Implicit and Explicit Instruction of Spelling Rules

ERIC Educational Resources Information Center

Kemper, M. J.; Verhoeven, L.; Bosman, A. M. T.

2012-01-01

The study aimed to compare the differential effectiveness of explicit and implicit instruction of two Dutch spelling rules. Students with and without spelling disabilities were instructed a spelling rule either implicitly or explicitly in two experiments. Effects were tested in a pretest-intervention-posttest control group design. Experiment 1…

The Role of Self-Efficacy for Bystander Helping Behaviors in Risky Alcohol Situations

PubMed Central

Krieger, Heather; Serrano, Surizaday; Neighbors, Clayton

2017-01-01

We examined the role of self-efficacy in preventing bystander inaction in dangerous alcohol situations. Participants (N = 504) completed an online survey that assessed whether they had previously witnessed or intervened in alcohol-related emergencies, their self-efficacy for intervening, and their likelihood of intervening in the future. Previously intervening was positively associated with self-efficacy and likelihood of intervening in the future. Furthermore, self-efficacy mediated the association between previously intervening and likelihood of intervening in the future. In conclusion, self-efficacy for intervening in social situations is associated with intervening in alcohol-related emergencies and is an important factor to consider when designing bystander interventions. PMID:29097835

The Role of Self-Efficacy for Bystander Helping Behaviors in Risky Alcohol Situations.

PubMed

Krieger, Heather; Serrano, Surizaday; Neighbors, Clayton

2017-04-01

We examined the role of self-efficacy in preventing bystander inaction in dangerous alcohol situations. Participants (N = 504) completed an online survey that assessed whether they had previously witnessed or intervened in alcohol-related emergencies, their self-efficacy for intervening, and their likelihood of intervening in the future. Previously intervening was positively associated with self-efficacy and likelihood of intervening in the future. Furthermore, self-efficacy mediated the association between previously intervening and likelihood of intervening in the future. In conclusion, self-efficacy for intervening in social situations is associated with intervening in alcohol-related emergencies and is an important factor to consider when designing bystander interventions.

A decade of studying implicit racial/ethnic bias in healthcare providers using the implicit association test.

PubMed

Maina, Ivy W; Belton, Tanisha D; Ginzberg, Sara; Singh, Ajit; Johnson, Tiffani J

2018-02-01

Disparities in the care and outcomes of US racial/ethnic minorities are well documented. Research suggests that provider bias plays a role in these disparities. The implicit association test enables measurement of implicit bias via tests of automatic associations between concepts. Hundreds of studies have examined implicit bias in various settings, but relatively few have been conducted in healthcare. The aim of this systematic review is to synthesize the current knowledge on the role of implicit bias in healthcare disparities. A comprehensive literature search of several databases between May 2015 and September 2016 identified 37 qualifying studies. Of these, 31 found evidence of pro-White or light-skin/anti-Black, Hispanic, American Indian or dark-skin bias among a variety of HCPs across multiple levels of training and disciplines. Fourteen studies examined the association between implicit bias and healthcare outcomes using clinical vignettes or simulated patients. Eight found no statistically significant association between implicit bias and patient care while six studies found that higher implicit bias was associated with disparities in treatment recommendations, expectations of therapeutic bonds, pain management, and empathy. All seven studies that examined the impact of implicit provider bias on real-world patient-provider interaction found that providers with stronger implicit bias demonstrated poorer patient-provider communication. Two studies examined the effect of implicit bias on real-world clinical outcomes. One found an association and the other did not. Two studies tested interventions aimed at reducing bias, but only one found a post-intervention reduction in implicit bias. This review reveals a need for more research exploring implicit bias in real-world patient care, potential modifiers and confounders of the effect of implicit bias on care, and strategies aimed at reducing implicit bias and improving patient-provider communication. Future studies have the opportunity to build on this current body of research, and in doing so will enable us to achieve equity in healthcare and outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Effects of Oncologist Implicit Racial Bias in Racially Discordant Oncology Interactions

PubMed Central

Dovidio, John F.; Gonzalez, Richard; Albrecht, Terrance L.; Chapman, Robert; Foster, Tanina; Harper, Felicity W.K.; Hagiwara, Nao; Hamel, Lauren M.; Shields, Anthony F.; Gadgeel, Shirish; Simon, Michael S.; Griggs, Jennifer J.; Eggly, Susan

2016-01-01

Purpose Health providers’ implicit racial bias negatively affects communication and patient reactions to many medical interactions. However, its effects on racially discordant oncology interactions are largely unknown. Thus, we examined whether oncologist implicit racial bias has similar effects in oncology interactions. We further investigated whether oncologist implicit bias negatively affects patients’ perceptions of recommended treatments (i.e., degree of confidence, expected difficulty). We predicted oncologist implicit bias would negatively affect communication, patient reactions to interactions, and, indirectly, patient perceptions of recommended treatments. Methods Participants were 18 non-black medical oncologists and 112 black patients. Oncologists completed an implicit racial bias measure several weeks before video-recorded treatment discussions with new patients. Observers rated oncologist communication and recorded interaction length of time and amount of time oncologists and patients spoke. Following interactions, patients answered questions about oncologists’ patient-centeredness and difficulty remembering contents of the interaction, distress, trust, and treatment perceptions. Results As predicted, oncologists higher in implicit racial bias had shorter interactions, and patients and observers rated these oncologists’ communication as less patient-centered and supportive. Higher implicit bias also was associated with more patient difficulty remembering contents of the interaction. In addition, oncologist implicit bias indirectly predicted less patient confidence in recommended treatments, and greater perceived difficulty completing them, through its impact on oncologists’ communication (as rated by both patients and observers). Conclusion Oncologist implicit racial bias is negatively associated with oncologist communication, patients’ reactions to racially discordant oncology interactions, and patient perceptions of recommended treatments. These perceptions could subsequently directly affect patient-treatment decisions. Thus, implicit racial bias is a likely source of racial treatment disparities and must be addressed in oncology training and practice. PMID:27325865

The Effects of Oncologist Implicit Racial Bias in Racially Discordant Oncology Interactions.

PubMed

Penner, Louis A; Dovidio, John F; Gonzalez, Richard; Albrecht, Terrance L; Chapman, Robert; Foster, Tanina; Harper, Felicity W K; Hagiwara, Nao; Hamel, Lauren M; Shields, Anthony F; Gadgeel, Shirish; Simon, Michael S; Griggs, Jennifer J; Eggly, Susan

2016-08-20

Health providers' implicit racial bias negatively affects communication and patient reactions to many medical interactions. However, its effects on racially discordant oncology interactions are largely unknown. Thus, we examined whether oncologist implicit racial bias has similar effects in oncology interactions. We further investigated whether oncologist implicit bias negatively affects patients' perceptions of recommended treatments (i.e., degree of confidence, expected difficulty). We predicted oncologist implicit bias would negatively affect communication, patient reactions to interactions, and, indirectly, patient perceptions of recommended treatments. Participants were 18 non-black medical oncologists and 112 black patients. Oncologists completed an implicit racial bias measure several weeks before video-recorded treatment discussions with new patients. Observers rated oncologist communication and recorded interaction length of time and amount of time oncologists and patients spoke. Following interactions, patients answered questions about oncologists' patient-centeredness and difficulty remembering contents of the interaction, distress, trust, and treatment perceptions. As predicted, oncologists higher in implicit racial bias had shorter interactions, and patients and observers rated these oncologists' communication as less patient-centered and supportive. Higher implicit bias also was associated with more patient difficulty remembering contents of the interaction. In addition, oncologist implicit bias indirectly predicted less patient confidence in recommended treatments, and greater perceived difficulty completing them, through its impact on oncologists' communication (as rated by both patients and observers). Oncologist implicit racial bias is negatively associated with oncologist communication, patients' reactions to racially discordant oncology interactions, and patient perceptions of recommended treatments. These perceptions could subsequently directly affect patient-treatment decisions. Thus, implicit racial bias is a likely source of racial treatment disparities and must be addressed in oncology training and practice. © 2016 by American Society of Clinical Oncology.

Bystander Behavior in Bullying Situations: Basic Moral Sensitivity, Moral Disengagement and Defender Self-Efficacy

ERIC Educational Resources Information Center

Thornberg, Robert; Jungert, Tomas

2013-01-01

The aim of the present study was to investigate how basic moral sensitivity in bullying, moral disengagement in bullying and defender self-efficacy were related to different bystander behaviors in bullying. Therefore, we examined pathways that linked students' basic moral sensitivity, moral disengagement, and defender self-efficacy to different…

The Role of Self-Efficacy for Bystander Helping Behaviors in Risky Alcohol Situations

ERIC Educational Resources Information Center

Krieger, Heather; Serrano, Surizaday; Neighbors, Clayton

2017-01-01

We examined the role of self-efficacy in preventing bystander inaction in dangerous alcohol situations. Participants (N = 504) completed an online survey that assessed whether they had previously witnessed or intervened in alcohol-related emergencies, their self-efficacy for intervening, and their likelihood of intervening in the future.…

Reducing Sexual Violence on Campus: The Role of Student Leaders as Empowered Bystanders

ERIC Educational Resources Information Center

Banyard, Victoria L.; Moynihan, Mary M.; Crossman, Maria T.

2009-01-01

Sexual violence is a widespread problem for college communities. Students, faculty, and staff are increasingly involved in prevention efforts. To date, however, evaluation of sexual violence prevention programs has shown mixed results. One promising new practice teaches segments of college communities to be engaged, positive bystanders. It aims to…

Counseling and the Bystander-Equity Model of Supervisory Helping Behavior: Directions for EAP Research.

ERIC Educational Resources Information Center

Gerstein, Lawrence H.; Bayer, Gregory A.

1991-01-01

Discusses contribution of Bystander-Equity Model of Supervisory Helping Behavior to pursuit of employee assistance program (EAP) research based on traditions of field of counseling. Offers structure for pursuing empirical and applied activities in EAP settings. Encourages counseling researchers and practitioners to respond to challenge of working…

A Qualitative Exploration of Cyber-Bystanders and Moral Engagement

ERIC Educational Resources Information Center

Price, Deborah; Green, Deborah; Spears, Barbara; Scrimgeour, Margaret; Barnes, Alan; Geer, Ruth; Johnson, Bruce

2014-01-01

Studies have found that moral disengagement plays a significant role in the continuation of bullying situations (Bonanno, 2005); however, the moral stance of cyber-bystanders--those who witness online bullying--is not yet clear. While research into traditional face-to-face bullying reported that peers would probably or certainly intervene to…

Active defending and passive bystanding behavior in bullying: the role of personal characteristics and perceived peer pressure.

PubMed

Pozzoli, Tiziana; Gini, Gianluca

2010-08-01

This study examined the role of pro-victim attitudes, personal responsibility, coping responses to observations of bullying, and perceived peer normative pressure in explaining defending the victim and passive bystanding behavior in bullying. A total of 462 Italian early adolescents (mean age = 13.4 years, SD = 9 months) participated in the study. The behaviors were measured through two informants: each individual student and the teachers. The findings of a series of hierarchical regressions showed that, regardless of the informant, problem solving coping strategies and perceived peer normative pressure for intervention were positively associated with active help towards a bullied peer and negatively related to passivity. In contrast, distancing strategies were positively associated with passive bystanding, whereas they were negatively associated with teacher-reported defending behavior. Moreover, self-reported defending behavior was positively associated with personal responsibility for intervention, but only under conditions of low perceived peer pressure. Finally, the perception of peer pressure for intervention buffered the negative influence of distancing on passive bystanding tendencies. Future directions are discussed.

Addressing sexual and relationship violence in the LGBT community using a bystander framework.

PubMed

Potter, Sharyn J; Fountain, Kim; Stapleton, Jane G

2012-01-01

Sexual and relationship violence are two major public health issues that affect an alarming number of undergraduate students. As a result, many colleges and universities have protocols to serve victims of these forms of violence. Despite federal legislation stating that all students should have equitable experiences, current protocols and programs focus primarily on heterosexual students. College student victims of sexual and relationship violence who identify as lesbian, gay, bisexual, or transgender can face particular challenges, including disclosure of their sexual and gender orientations, and revictimization when seeking services. In recent years an increasing number of campuses have adopted bystander prevention strategies to address sexual and relationship violence. These strategies seek to engage community members in the prevention of sexual and relationship violence by training them to identify and safely intervene in situations where sexual or relationship violence is about to occur, is occurring, or has occurred. In this article we review published bystander prevention strategies that focus on preventing sexual and relationship violence in the campus community, and discuss how bystander strategies are addressing or can address relationship and sexual violence in the LGBT community.

Time-of-day effects in implicit racial in-group preferences are likely selection effects, not circadian rhythms

PubMed Central

2016-01-01

Time-of-day effects in human psychological functioning have been known of since the 1800s. However, outside of research specifically focused on the quantification of circadian rhythms, their study has largely been neglected. Moves toward online data collection now mean that psychological investigations take place around the clock, which affords researchers the ability to easily study time-of-day effects. Recent analyses have shown, for instance, that implicit attitudes have time-of-day effects. The plausibility that these effects indicate circadian rhythms rather than selection effects is considered in the current study. There was little evidence that the time-of-day effects in implicit attitudes shifted appropriately with factors known to influence the time of circadian rhythms. Moreover, even variables that cannot logically show circadian rhythms demonstrated stronger time-of-day effects than did implicit attitudes. Taken together, these results suggest that time-of-day effects in implicit attitudes are more likely to represent processes of selection rather than circadian rhythms, but do not rule out the latter possibility. PMID:27114886

Time-of-day effects in implicit racial in-group preferences are likely selection effects, not circadian rhythms.

PubMed

Schofield, Timothy P

2016-01-01

Time-of-day effects in human psychological functioning have been known of since the 1800s. However, outside of research specifically focused on the quantification of circadian rhythms, their study has largely been neglected. Moves toward online data collection now mean that psychological investigations take place around the clock, which affords researchers the ability to easily study time-of-day effects. Recent analyses have shown, for instance, that implicit attitudes have time-of-day effects. The plausibility that these effects indicate circadian rhythms rather than selection effects is considered in the current study. There was little evidence that the time-of-day effects in implicit attitudes shifted appropriately with factors known to influence the time of circadian rhythms. Moreover, even variables that cannot logically show circadian rhythms demonstrated stronger time-of-day effects than did implicit attitudes. Taken together, these results suggest that time-of-day effects in implicit attitudes are more likely to represent processes of selection rather than circadian rhythms, but do not rule out the latter possibility.

Trends in public information within the Fairfax Alcohol Safety Action Project, 1976.

DOT National Transportation Integrated Search

1979-01-01

In general, there was little evidence that the public information countermeasure was effective in increasing awareness or overall knowledge, or in improving attitudes. The major exceptions to this were the self-reported increase in bystander interven...

Low dose radiation effects on the brain - from mechanisms and behavioral outcomes to mitigation strategies.

PubMed

Kovalchuk, Anna; Kolb, Bryan

2017-07-03

Based on the most recent estimates by the Canadian Cancer Society, 2 in 5 Canadians will develop cancer in their lifetimes. More than half of all cancer patients receive some type of radiation therapy, and all patients undergo radiation-based diagnostics. While radiation is one of the most important diagnostic and treatments modalities, high-dose cranial radiation therapy causes numerous central nervous system side-effects, including declines in cognitive function, memory, and attention. While the mechanisms of these effects have been studies, they still need to be further elucidated. On the other hand, the effects of low dose radiation as well as indirect radiation bystander effects on the brain remain elusive. We pioneered analysis of the molecular and cellular effects of low dose direct, bystander and scatter radiation on the brain. Using a rat model, we showed that low dose radiation exposures cause molecular and cellular changes in the brain and impacts animal behavior. Here we reflect upon our recent findings and current state of knowledge in the field, and suggest novel radiation effect biomarkers and means of prevention. We propose strategies and interventions to prevent and mitigate radiation effects on the brain.

Do College Instructors Have Implicit Bias toward Latino-Accented English Speakers?

ERIC Educational Resources Information Center

Na, Eunkyung

2016-01-01

The purpose of this study was to examine the implicit attitudes of college-level instructors toward Latino-accented English and the effects of gender, teaching experience, home language, race/ethnicity, and rank on those attitudes. The auditory Implicit Association Test (IAT) was used to measure the implicit accent preferences. Participants (N =…

The Effects of Mindfulness versus Thought Suppression on Implicit and Explicit Measures of Experiential Avoidance

ERIC Educational Resources Information Center

Hooper, Nic; Villatte, Matthieu; Neofotistou, Evi; McHugh, Louise

2010-01-01

The current study aimed to provide an implicit measure of experiential avoidance (EA). Fifty undergraduate participants were exposed to an implicit (Implicit Relational Assessment Procedure: IRAP) and an explicit (Acceptance and Action Questionnaire II: AAQ II) measure of EA. Subsequently participant's response latencies on viewing a negatively…

Impact of the ConRed program on different cyberbulling roles.

PubMed

Del Rey, Rosario; Casas, José A; Ortega, Rosario

2016-01-01

This article presents results from an evaluation of the ConRed cyberbullying intervention program. The program's impacts were separately determined for the different roles within cyberbullying that students can take, i.e., cyber-victims, cyber-bullies, cyber-bully/victims, and bystanders. The ConRed program is a theory-driven program designed to prevent cyberbullying and improve cyberbullying coping skills. It involves students, teachers, and families. During a 3-month period, external experts conducted eight training sessions with students, two with teachers and one with families. ConRed was evaluated through a quasi-experimental design, in which students from three secondary schools were separated into experimental and control groups. The sample comprised 875 students, aged between 11 and 19 years. More students (n = 586) were allocated to the experimental groups at the specific insistence of the management of all schools; the remainder (n = 289) formed the control. Repeated measures MANOVA showed that cyber victims, cyber aggressors and cyberbully/victims reduced their involvement in cyberbullying. Moreover, cyber-victims and bystanders adjusted their perceptions about their control of personal information on the Internet, and cyber aggressors and bystanders reduced their Internet dependence. The ConRed program had stronger effects on male participants, especially in heightening their affective empathy. © 2015 Wiley Periodicals, Inc.

The safe use of automated external defibrillators in a wet environment.

PubMed

Lyster, Tom; Jorgenson, Dawn; Morgan, Carl

2003-01-01

There has been concern regarding potential shock hazards for rescuers or bystanders when a defibrillator is used in a wet environment and the recommended safety procedure, moving the patient to a dry area, is not followed. To measure the electrical potentials associated with the use of an automated external defibrillator (AED) in a realistically modeled wet environment. A raw processed turkey was used as a patient surrogate. The turkey was placed on a cement floor while pool water was applied to the surrounding area. To simulate a rescuer or bystander in the vicinity of a patient, a custom sense probe was constructed. Defibrillation shocks were delivered to the turkey and the probe was used to measure the voltage an operator/bystander would receive at different points surrounding the surrogate. The test was repeated with salt water. The maximum voltage occurred approximately 15 cm from the simulated patient and measured 14 V peak (current 14 mA peak) in the case of pool water, and 30 V peak (current 30 mA peak) in the case of salt water. Thirty volts may result in some minor sensation by the operator or bystander, but is considered unlikely to be hazardous under these circumstances. The maximum currents were lower than allowed by safety standards. Although defibrillation in a wet environment is not recommended practice, our simulation of a patient and a rescuer/bystander in a wet environment did not show significant risk should circumstances demand it.

Anterior Cingulate Cortex Contributes to Alcohol Withdrawal- Induced and Socially Transferred Hyperalgesia.

PubMed

Smith, Monique L; Walcott, Andre T; Heinricher, Mary M; Ryabinin, Andrey E

2017-01-01

Pain is often described as a "biopsychosocial" process, yet social influences on pain and underlying neural mechanisms are only now receiving significant experimental attention. Expression of pain by one individual can be communicated to nearby individuals by auditory, visual, and olfactory cues. Conversely, the perception of another's pain can lead to physiological and behavioral changes in the observer, which can include induction of hyperalgesia in "bystanders" exposed to "primary" conspecifics in which hyperalgesia has been induced directly. The current studies were designed to investigate the neural mechanisms responsible for the social transfer of hyperalgesia in bystander mice housed and tested with primary mice in which hyperalgesia was induced using withdrawal (WD) from voluntary alcohol consumption. Male C57BL/6J mice undergoing WD from a two-bottle choice voluntary alcohol-drinking procedure served as the primary mice. Mice housed in the same room served as bystanders. Naïve, water-drinking controls were housed in a separate room. Immunohistochemical mapping identified significantly enhanced Fos immunoreactivity (Fos-ir) in the anterior cingulate cortex (ACC) and insula (INS) of bystander mice compared to naïve controls, and in the dorsal medial hypothalamus (DMH) of primary mice. Chemogenetic inactivation of the ACC but not primary somatosensory cortex reversed the expression of hyperalgesia in both primary and bystander mice. These studies point to an overlapping neural substrate for expression of socially transferred hyperalgesia and that expressed during alcohol WD.

Propositional Versus Dual-Process Accounts of Evaluative Conditioning: I. The Effects of Co-Occurrence and Relational Information on Implicit and Explicit Evaluations.

PubMed

Hu, Xiaoqing; Gawronski, Bertram; Balas, Robert

2017-01-01

Evaluative conditioning (EC) is defined as the change in the evaluation of a conditioned stimulus (CS) due to its pairing with a valenced unconditioned stimulus (US). According to propositional accounts, EC effects should be qualified by the relation between the CS and the US. Dual-process accounts suggest that relational information should qualify EC effects on explicit evaluations, whereas implicit evaluations should reflect the frequency of CS-US co-occurrences. Experiments 1 and 2 showed that, when relational information was provided before the encoding of CS-US pairings, it moderated EC effects on explicit, but not implicit, evaluations. In Experiment 3, relational information moderated EC effects on both explicit and implicit evaluations when it was provided simultaneously with CS-US pairings. Frequency of CS-US pairings had no effect on implicit evaluations. Although the results can be reconciled with both propositional and dual-process accounts, they are more parsimoniously explained by propositional accounts.

Implicit Learning of Viewpoint-Independent Spatial Layouts

PubMed Central

Tsuchiai, Taiga; Matsumiya, Kazumichi; Kuriki, Ichiro; Shioiri, Satoshi

2012-01-01

We usually perceive things in our surroundings as unchanged despite viewpoint changes caused by self-motion. The visual system therefore must have a function to process objects independently of viewpoint. In this study, we examined whether viewpoint-independent spatial layout can be obtained implicitly. For this purpose, we used a contextual cueing effect, a learning effect of spatial layout in visual search displays known to be an implicit effect. We investigated the transfer of the contextual cueing effect to images from a different viewpoint by using visual search displays of 3D objects. For images from a different viewpoint, the contextual cueing effect was maintained with self-motion but disappeared when the display changed without self-motion. This indicates that there is an implicit learning effect in environment-centered coordinates and suggests that the spatial representation of object layouts can be obtained and updated implicitly. We also showed that binocular disparity plays an important role in the layout representations. PMID:22740837

I like myself but I don't know why: enhancing implicit self-esteem by subliminal evaluative conditioning.

PubMed

Dijksterhuis, Ap

2004-02-01

On the basis of a conceptualization of implicit self-esteem as the implicit attitude toward the self, it was predicted that implicit self-esteem could be enhanced by subliminal evaluative conditioning. In 5 experiments, participants were repeatedly presented with trials in which the word I was paired with positive trait terms. Relative to control conditions, this procedure enhanced implicit self-esteem. The effects generalized across 3 measures of implicit self-esteem (Experiments 1-3). Furthermore, evaluative conditioning enhanced implicit self-esteem among people with low-temporal implicit self-esteem and among people with high-temporal implicit self-esteem (Experiment 4). In addition, it was shown that conditioning enhanced self-esteem to such an extent that it made participants insensitive to negative intelligence feedback (Experiments 5a and 5b). Various implications are discussed.

"Caught with a body" yet protected by law? Calling 911 for opioid overdose in the context of the Good Samaritan Law.

PubMed

Latimore, Amanda D; Bergstein, Rachel S

2017-12-01

To address soaring opioid overdose fatality rates, 41U.S. states have passed Good Samaritan Laws (GSLs) extending legal immunity to overdose bystanders who call for emergency assistance. This study, conducted during the period that followed implementation of a GSL, aimed to characterize current factors determining the decision to call for emergency medical help (911) at the scene of an overdose with specific attention to exploring the role of the GSL as one such factor in decision-making. We conducted 22 in-depth interviews with needle exchange program clients in Baltimore, MD. Most participants reported calling 911 or witnessing a 911 call after drug overdose, but widely remained fearful of arrest for drug or paraphernalia possession, homicide, outstanding warrants, and/or trespassing. These concerns were underpinned by a history of police maltreatment and threat, and strong distrust of police; concerns which were specifically related to perceptions of police conduct at the scene of an overdose as well as perceptions of police conduct in general. Additional considerations included: fear of losing housing, informal shelter or custody of children; encountering social stigma; and facing violent and fatal repercussions at the hands of local drug dealers. Additionally, some participants did not perceive a significant enough medical risk to call 911. Two thirds of participants were unaware of the GSL. Some believed a GSL would positively impact law enforcement behaviour and increase the likelihood of a bystander call; but due to distrust of police, others believed the GSL would have little influence on bystander decisions. Insights from overdose bystanders during the post-implementation period of a Good Samaritan Law demonstrate persistent deterrents to bystanders calling 911 after overdose. Additional measures are needed to align policy aims with lived experiences of overdose bystanders, and to achieve overdose prevention aims. Copyright © 2017 Elsevier B.V. All rights reserved.

Are regional variations in activity of dispatcher-assisted cardiopulmonary resuscitation associated with out-of-hospital cardiac arrests outcomes? A nation-wide population-based cohort study.

PubMed

Nishi, Taiki; Kamikura, Takahisa; Funada, Akira; Myojo, Yasuhiro; Ishida, Tetsuya; Inaba, Hideo

2016-01-01

Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) impacts the rates of bystander CPR (BCPR) and survival after out-of-hospital cardiac arrests (OHCAs). This study aimed to elucidate whether regional variations in indexes for BCPR and emergency medical service (EMS) may be associated with OHCA outcomes. We conducted a population-based observational study involving 157,093 bystander-witnessed, resuscitation-attempted OHCAs without physician involvement between 2007 and 2011. For each index of BCPR and EMS, we classified the 47 prefectures into the following three groups: advanced, intermediate, and developing regions. Nominal logit analysis followed by multivariable logistic regression including OHCA backgrounds was employed to examine the association between neurologically favourable 1-month survival, and regional classifications based on BCPR- and EMS-related indexes. Logit analysis including all regional classifications revealed that the number of BLS training course participants per population or bystander's own performance of BCPR without DA-CPR was not associated with the survival. Multivariable logistic regression including the OHCA backgrounds known to be associated with survival (BCPR provision, arrest aetiology, initial rhythm, patient age, time intervals of witness-to-call and call-to-arrival at patient), the following regional classifications based on DA-CPR but not on EMS were associated with survival: sensitivity of DA-CPR [adjusted odds ratio (95% confidence intervals) for advanced region; those for intermediate region, with developing region as reference, 1.277 (1.131-1.441); 1.162 (1.058-1.277)]; the proportion of bystanders to follow DA-CPR [1.749 (1.554-1.967); 1.280 (1.188-1.380)]. Good outcomes of bystander-witnessed OHCAs correlate with regions having higher sensitivity of DA-CPR and larger proportion of bystanders to follow DA-CPR. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Do Some People Need Autonomy More Than Others? Implicit Dispositions Toward Autonomy Moderate the Effects of Felt Autonomy on Well-Being.

PubMed

Schüler, Julia; Sheldon, Kennon M; Prentice, Mike; Halusic, Marc

2016-02-01

The present studies examined whether implicit or explicit autonomy dispositions moderate the relationship between felt autonomy and well-being. Study 1 (N = 187 undergraduate students) presents an initial test of the moderator hypothesis by predicting flow experience from the interaction of autonomy need satisfaction and autonomy dispositions. Study 2 (N = 127 physically inactive persons) used vignettes involving an autonomy (un)supportive coach to test a moderated mediation model in which perceived coach autonomy support leads to well-being through basic need satisfaction. Again, the effects of need satisfaction on well-being were hypothesized to be moderated by an implicit autonomy disposition. Study 1 showed that individuals with a strong implicit autonomy (but not power or achievement) motive disposition derived more flow experience from felt autonomy than individuals with a weak implicit autonomy disposition. Study 2 revealed that perceived autonomy support from sports coaches, which we experimentally induced with a vignette method, leads to autonomy satisfaction, leading in turn to positive effects on well-being. This indirect effect held at high and average but not low implicit autonomy disposition. The results indicate that the degree to which people benefit from autonomy need satisfaction depends on their implicit disposition toward autonomy. © 2014 Wiley Periodicals, Inc.

Impact of implicit effects on uncertainties and sensitivities of the Doppler coefficient of a LWR pin cell

NASA Astrophysics Data System (ADS)

Hursin, Mathieu; Leray, Olivier; Perret, Gregory; Pautz, Andreas; Bostelmann, Friederike; Aures, Alexander; Zwermann, Winfried

2017-09-01

In the present work, PSI and GRS sensitivity analysis (SA) and uncertainty quantification (UQ) methods, SHARK-X and XSUSA respectively, are compared for reactivity coefficient calculation; for reference the results of the TSUNAMI and SAMPLER modules of the SCALE code package are also provided. The main objective of paper is to assess the impact of the implicit effect, e.g., considering the effect of cross section perturbation on the self-shielding calculation, on the Doppler coefficient SA and UQ. Analyses are done for a Light Water Reactor (LWR) pin cell based on Phase I of the UAM LWR benchmark. The negligence of implicit effects in XSUSA and TSUNAMI leads to deviations of a few percent between the sensitivity profiles compared to SAMPLER and TSUNAMI (incl. implicit effects) except for 238U elastic scattering. The implicit effect is much larger for the SHARK-X calculations because of its coarser energy group structure between 10 eV and 10 keV compared to the applied SCALE libraries. It is concluded that the influence of the implicit effect strongly depends on the energy mesh of the nuclear data library of the neutron transport solver involved in the UQ calculations and may be magnified by the response considered.

Emotion effects on implicit and explicit musical memory in normal aging.

PubMed

Narme, Pauline; Peretz, Isabelle; Strub, Marie-Laure; Ergis, Anne-Marie

2016-12-01

Normal aging affects explicit memory while leaving implicit memory relatively spared. Normal aging also modifies how emotions are processed and experienced, with increasing evidence that older adults (OAs) focus more on positive information than younger adults (YAs). The aim of the present study was to investigate how age-related changes in emotion processing influence explicit and implicit memory. We used emotional melodies that differed in terms of valence (positive or negative) and arousal (high or low). Implicit memory was assessed with a preference task exploiting exposure effects, and explicit memory with a recognition task. Results indicated that effects of valence and arousal interacted to modulate both implicit and explicit memory in YAs. In OAs, recognition was poorer than in YAs; however, recognition of positive and high-arousal (happy) studied melodies was comparable. Insofar as socioemotional selectivity theory (SST) predicts a preservation of the recognition of positive information, our findings are not fully consistent with the extension of this theory to positive melodies since recognition of low-arousal (peaceful) studied melodies was poorer in OAs. In the preference task, YAs showed stronger exposure effects than OAs, suggesting an age-related decline of implicit memory. This impairment is smaller than the one observed for explicit memory (recognition), extending to the musical domain the dissociation between explicit memory decline and implicit memory relative preservation in aging. Finally, the disproportionate preference for positive material seen in OAs did not translate into stronger exposure effects for positive material suggesting no age-related emotional bias in implicit memory. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Dissociation between implicit and explicit expectancies of cannabis use in adolescence.

PubMed

Schmits, Emilie; Maurage, Pierre; Thirion, Romain; Quertemont, Etienne

2015-12-30

Cannabis is one of the most commonly drugs used by teenagers. Expectancies about its effects play a crucial role in cannabis consumption. Various tools have been used to assess expectancies, mainly self-report questionnaires measuring explicit expectancies, but implicit measures based on experimental tasks have also been developed, measuring implicit expectancies. The aim of this study was to simultaneously assess implicit/explicit expectancies related to cannabis among adolescent users and non-users. 130 teenagers attending school (55 girls) were enrolled (Age: M=16.40 years); 43.84% had never used cannabis ("non-users") and 56.16% had used cannabis ("users"). They completed self-report questionnaires evaluating cannabis use, cannabis-related problems, effect expectancies (explicit expectancies), alcohol use, social and trait anxiety, depression, as well as three Implicit Association Tests (IAT) assessing implicit expectancies. Adolescents manifested more implicit affective associations (relaxation, excitation, negative) than neutral ones regarding cannabis. These were not related to explicit expectancies. Cannabis users reported more implicit relaxation expectancies and less negative explicit expectancies than non-users. The frequency of use and related problems were positively associated with the explicit expectancies regarding relaxation and enhancement, and were negatively associated with negative explicit expectancies and negative implicit expectancies. Findings indicate that implicit and explicit expectancies play different roles in cannabis use by adolescents. The implications for experimentation and prevention are discussed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

[Killing effects of PWZL plasmid-mediated double suicide gene on human lens epithelium cells].

PubMed

Yan, Xiao-ran; Wu, Hong; Yu, Hai-tao; Wang, Xiu; Zhang, Yu

2008-04-01

To investigate the killing efficiency of PWZL plasmid-mediated herpes simplex virus-thymidine kinase (TK) and E. coli cytosine deaminase (CD) on human lens epithelium cells followed by the treatment of prodrugs. PWZL plasmid was used as a vehicle, to transduce double suicide genes into the human lens epithelium in vitro, then the cells were treated with fluorocytosine (5-FC) and/or ganciclovir (GCV) at different concentrations. The cell growth of the lens epithelium cells was observed by light microscope. MTT analysis was used to estimate the cell survival rate and the bystander effect was analyzed simultaneously. The significance of difference between each group was treated by statistical tests. The CD and TK gene could be joined into PWZL plasmid successfully, and did not have any special effect on normal cells. There was no significant difference in cell viability between CD-TK transfected cells and control cells. Cell viability in cells treated with prodrugs was decreased in a time-dependent manner. At the end of the experiment, cell viability was lowest in GCV 10 mg/L +5-FC 60 mg/L group, GCV 10 mg/L + 5-FC 100 mg/L group and GCV 100 mg/L + 5-FC 100 mg/L group. There were no significant differences between these three groups (X2 = 1.25 , P > 0.01). Analysis of bystander effect indicated that the cell viability in GCV 100 mg/L + 5-FC 100 mg/L group and GCV 10 mg/L +5-FC 60 mg/L group was significantly lower than that in the controls (t = 10.26, 13.16; P < 0.01). PWZL plasmid can transfect the CD and TK genes into lens epithelium cells successfully and efficiently. CD and TK genes can be expressed steadily. Transfection of double suicide gene reduces the dosage of prodrugs required for killing cells. The combination of 5-FC with GCV shows the greatest killing effect and also has the bystander effect.

Participant Roles in Bullying: How Can Peer Bystanders Be Utilized in Interventions?

ERIC Educational Resources Information Center

Salmivalli, Christina

2014-01-01

This article provides a view of school bullying as a group phenomenon and practical implications stemming from this approach. The motivation for bullying perpetration often relates to one's social standing in the group. Peer bystanders are typically present when bullying takes place, often providing the perpetrators with social rewards. The…

Bystanders to Bullying: Fourth-to Seventh-Grade Students' Perspectives on Their Reactions

ERIC Educational Resources Information Center

Forsberg, Camilla; Thornberg, Robert; Samuelsson, Marcus

2014-01-01

The aim with the present study was to investigate bystander actions in bullying situations as well as reasons behind these actions as they are articulated by Swedish students from fourth to seventh grade. Forty-three semi-structured individual interviews were conducted with students. Qualitative analysis of data was performed by methods from…

Bystanders' Reactions to Bullying: A Cross-Cultural Analysis of Personal Correlates among Italian and Singaporean Students

ERIC Educational Resources Information Center

Pozzoli, Tiziana; Ang, Rebecca P.; Gini, Gianluca

2012-01-01

This study examined the role of attitudes against bullying and perceived peer pressure for intervention in explaining defending the victim and passive bystanding behavior in bullying. Participants were 1031 school-age children from two culturally diverse settings, namely Italy and Singapore, which are similar on several dimensions (e.g., quality…

Tell the Teacher or Tell the Bully Off: Children's Strategy Production for Bystanders to Bullying

ERIC Educational Resources Information Center

Rock, Patrick F.; Baird, Jodie A.

2012-01-01

Although children's reticence to intervene as bystanders to bullying is well established, the reasons for their inaction remain unclear. One possibility is that they are incapable of generating appropriate response strategies in these situations. This study examined the number and type of strategies children (N = 104, 6-11 years) could generate…

Bystander Reaction to Women Fighting: Developing a Theory of Intervention

ERIC Educational Resources Information Center

Lowe, Robert D.; Levine, Mark; Best, Rachel M.; Heim, Derek

2012-01-01

This article explores accounts of bystanders to female-on-female public violence. Group interviews with participants in the night-time economy are carried out. Whereas men tend to respond to the discussion topic of female-on-female violence with laughter, this laughter reveals ambivalence and discomfort as much as amusement. Men seem to negotiate…

Bystanders not so innocent after all.

PubMed

Batten, Marcel; Ghilardi, Nico

2012-06-29

Interleukin 27 (IL-27) regulates immune responses, including T helper 17 (Th17) cell activity. In this issue of Immunity, Hirahara et al. (2012) demonstrate that IL-27 suppresses Th17 cells in trans through induction of the inhibitory ligand PD-L1 on bystander T cells. Copyright © 2012 Elsevier Inc. All rights reserved.

Noble or Malevolent in a Moment of Dismay: How Postsecondary Students Construe and Characterize Bystander Action in School Violence Shooting Incidents

ERIC Educational Resources Information Center

Underhill, Dyan Whitlow

2012-01-01

Multiple incidents of postsecondary school shooting violence have occurred in American society--prompting concern about safety on college campuses, administrators' roles in prevention, and proactive and responsible bystander actions. Active shooter plans have become more established in educational environments, with efforts are directed…

A Mixed Methods Evaluation of the "Aged-Up" STAC Bullying Bystander Intervention for High School Students

ERIC Educational Resources Information Center

Johnston, April D.; Midgett, Aida; Doumas, Diana M.; Moody, Steve

2018-01-01

This mixed methods study assessed the appropriateness of an "aged-up," brief bullying bystander intervention (STAC) and explored the lived experiences of high school students trained in the program. Quantitative results included an increase in knowledge and confidence to intervene in bullying situations, awareness of bullying, and use of…

Bystander Intervention, Bullying, and Victimization: A Multilevel Analysis of New Zealand High Schools

ERIC Educational Resources Information Center

Denny, Simon; Peterson, Elizabeth R.; Stuart, Jaimee; Utter, Jennifer; Bullen, Pat; Fleming, Theresa; Ameratunga, Shanthi; Clark, Terryann; Milfont, Taciano

2015-01-01

This study examines the association between schools and student bullying behaviors and victimization among a nationally representative sample (N = 9,107) of New Zealand high school students. In particular, the study sought to explore the role of characteristics of schools and school culture with respect to bystander behavior, while controlling for…

Using a Multimedia Social Marketing Campaign to Increase Active Bystanders on the College Campus

ERIC Educational Resources Information Center

Potter, Sharyn J.

2012-01-01

Objective: To evaluate the campus-wide administration of the Know Your Power bystander-oriented social marketing campaign. Participants: Undergraduate students at a public college were invited to participate in a public awareness survey before and after the 6-week campaign administration in February and March 2009. Methods: Pretest and posttests…

Out-of-hospital cardiac arrest surveillance --- Cardiac Arrest Registry to Enhance Survival (CARES), United States, October 1, 2005--December 31, 2010.

PubMed

McNally, Bryan; Robb, Rachel; Mehta, Monica; Vellano, Kimberly; Valderrama, Amy L; Yoon, Paula W; Sasson, Comilla; Crouch, Allison; Perez, Amanda Bray; Merritt, Robert; Kellermann, Arthur

2011-07-29

Each year, approximately 300,000 persons in the United States experience an out-of-hospital cardiac arrest (OHCA); approximately 92% of persons who experience an OHCA event die. An OHCA is defined as cessation of cardiac mechanical activity that occurs outside of the hospital setting and is confirmed by the absence of signs of circulation. Whereas an OHCA can occur from noncardiac causes (i.e., trauma, drowning, overdose, asphyxia, electrocution, primary respiratory arrests, and other noncardiac etiologies), the majority (70%--85%) of such events have a cardiac cause. The majority of persons who experience an OHCA event, irrespective of etiology, do not receive bystander-assisted cardiopulmonary resuscitation (CPR) or other timely interventions that are known to improve the likelihood of survival to hospital discharge (e.g., defibrillation). Because nearly half of cardiac arrest events are witnessed, efforts to increase survival rates should focus on timely and effective delivery of interventions by bystanders and emergency medical services (EMS) personnel. This is the first report to provide summary data from an OHCA surveillance registry in the United States. This report summarizes surveillance data collected during October 1, 2005-- December 31, 2010. In 2004, CDC established the Cardiac Arrest Registry to Enhance Survival (CARES) in collaboration with the Department of Emergency Medicine at the Emory University School of Medicine. This registry evaluates only OHCA events of presumed cardiac etiology that involve persons who received resuscitative efforts, including CPR or defibrillation. Participating sites collect data from three sources that define the continuum of emergency cardiac care: 911 dispatch centers, EMS providers, and receiving hospitals. OHCA is defined in CARES as a cardiac arrest that occurred in the prehospital setting, had a presumed cardiac etiology, and involved a person who received resuscitative efforts, including CPR or defibrillation. During October 1, 2005--December 31, 2010, a total of 40,274 OHCA records were submitted to the CARES registry. After noncardiac etiology arrests and missing hospital outcomes were excluded from the analysis (n = 8,585), 31,689 OHCA events of presumed cardiac etiology (e.g., myocardial infarction or arrhythmia) that received resuscitation efforts in the prehospital setting were analyzed. The mean age at cardiac arrest was 64.0 years (standard deviation [SD]: 18.2); 61.1% of persons who experienced OHCA were male (n = 19,360). According to local EMS agency protocols, 21.6% of patients were pronounced dead after resuscitation efforts were terminated in the prehospital setting. The survival rate to hospital admission was 26.3%, and the overall survival rate to hospital discharge was 9.6%. Approximately 36.7% of OHCA events were witnessed by a bystander. Only 33.3% of all patients received bystander CPR, and only 3.7% were treated by bystanders with an automated external defibrillator (AED) before the arrival of EMS providers. The group most likely to survive an OHCA are persons who are witnessed to collapse by a bystander and found in a shockable rhythm (e.g., ventricular fibrillation or pulseless ventricular tachycardia). Among this group, survival to discharge was 30.1%. A subgroup analysis was performed among persons who experienced OHCA events that were not witnessed by EMS personnel to evaluate rates of bystander CPR for these persons. After exclusion of 3,400 OHCA events that occurred after the arrival of EMS providers, bystander CPR information was analyzed for 28,289 events. In this group, whites were significantly more likely to receive CPR than blacks, Hispanics, or members of other racial/ethnic populations (p<0.001). Overall survival to hospital discharge of patients whose events were not witnessed by EMS personnel was 8.5%. Of these, patients who received bystander CPR had a significantly higher rate of overall survival (11.2%) than those who did not (7.0%) (p<0.001). CARES data have helped identify opportunities for improvement in OHCA care. The registry is being used continually to monitor prehospital performance and selected aspects of hospital care to improve quality of care and increase rates of survival following OHCA. CARES data confirm that patients who receive CPR from bystanders have a greater chance of surviving OHCA than those who do not. Medical directors and public health professionals in participating communities use CARES data to measure and improve the quality of prehospital care for persons experiencing OHCA. Tracking performance longitudinally allows communities to better understand which elements of their care are working well and which elements need improvement. Education of public officials and community members about the importance of increasing rates of bystander CPR and promoting the use of early defibrillation by lay and professional rescuers is critical to increasing survival rates. Reporting at the state and local levels can enable state and local public health and EMS agencies to coordinate their efforts to target improving emergency response for OHCA events, regardless of etiology, which can lead to improvement in OHCA survival rates.

Implicit Sequence Learning and Contextual Cueing Do Not Compete for Central Cognitive Resources

ERIC Educational Resources Information Center

Jimenez, Luis; Vazquez, Gustavo A.

2011-01-01

Sequence learning and contextual cueing explore different forms of implicit learning, arising from practice with a structured serial task, or with a search task with informative contexts. We assess whether these two learning effects arise simultaneously when both remain implicit. Experiments 1 and 2 confirm that a cueing effect can be observed…

The Effects of Peer Influences and Implicit and Explicit Attitudes on Smoking Initiation in Adolescence

ERIC Educational Resources Information Center

Bountress, Kaitlin; Chassin, Laurie; Presson, Clark C.; Jackson, Corrie

2016-01-01

Using participants from an 1-and-1/2-year longitudinal study of smoking socialization (N = 709), we examined peer smoking, and implicit and explicit attitudes on smoking initiation among initial nonsmoking adolescents. We also tested whether implicit and explicit attitudes mediated the effect of peer smoking on smoking initiation, and whether…

Cardiovascular change during encoding predicts the nonconscious mere exposure effect.

PubMed

Ladd, Sandra L; Toscano, William B; Cowings, Patricia S; Gabrieli, John D E

2014-01-01

These studies examined memory encoding to determine whether the mere exposure effect could be categorized as a form of conceptual or perceptual implicit priming and, if it was not conceptual or perceptual, whether cardiovascular psychophysiology could reveal its nature. Experiment 1 examined the effects of study phase level of processing on recognition, the mere exposure effect, and word identification implicit priming. Deep relative to shallow processing improved recognition but did not influence the mere exposure effect for nonwords or word identification implicit priming for words. Experiments 2 and 3 examined the effect of study-test changes in font and orientation, respectively, on the mere exposure effect and word identification implicit priming. Different study-test font and orientation reduced word identification implicit priming but had no influence on the mere exposure effect. Experiments 4 and 5 developed and used, respectively, a cardiovascular psychophysiological implicit priming paradigm to examine whether stimulus-specific cardiovascular reactivity at study predicted the mere exposure effect at test. Blood volume pulse change at study was significantly greater for nonwords that were later preferred than for nonwords that were not preferred at test. There was no difference in blood volume pulse change for words at study that were later either identified or not identified at test. Fluency effects, at encoding or retrieval, are an unlikely explanation for these behavioral and cardiovascular findings. The relation of blood volume pulse to affect suggests that an affective process that is not conceptual or perceptual contributes to the mere exposure effect.

Consider the source: persuasion of implicit evaluations is moderated by source credibility.

PubMed

Smith, Colin Tucker; De Houwer, Jan; Nosek, Brian A

2013-02-01

The long history of persuasion research shows how to change explicit, self-reported evaluations through direct appeals. At the same time, research on how to change implicit evaluations has focused almost entirely on techniques of retraining existing evaluations or manipulating contexts. In five studies, we examined whether direct appeals can change implicit evaluations in the same way as they do explicit evaluations. In five studies, both explicit and implicit evaluations showed greater evidence of persuasion following information presented by a highly credible source than a source low in credibility. Whereas cognitive load did not alter the effect of source credibility on explicit evaluations, source credibility had an effect on the persuasion of implicit evaluations only when participants were encouraged and able to consider information about the source. Our findings reveal the relevance of persuasion research for changing implicit evaluations and provide new ideas about the processes underlying both types of evaluation.

Categorization and Prediction of Crimes of Passion Based on Attitudes Toward Violence.

PubMed

Guan, Muzhen; Li, Xiaojing; Xiao, Wei; Miao, Danmin; Liu, Xufeng

2017-11-01

The present study explored implicit and explicit attitudes toward violence in crimes of passion. Criminals ( n = 96) who had perpetrated crimes of passion and students ( n = 100) participated in this study. Explicit attitudes toward violence were evaluated using the Abnormal Personality Risk Inventory (APRI), and implicit attitude toward violence was evaluated using the Implicit Association Test (IAT). Results indicated that APRI scores of the perpetrators were significantly higher than that of the control group ( p < .05), suggesting that explicit attitudes toward violence could discriminate between the criminals and the control group. There was a significant IAT effect demonstrating a negative implicit attitude toward violence in both the control group and in the criminals ( n = 68); whereas there was a significant IAT effect manifesting a positive implicit attitude toward violence in the criminals ( n = 16) only. These results suggest that combining explicit and implicit attitudes could provide an empirical classification of crimes of passion.

Long-term reduction in implicit race bias: A prejudice habit-breaking intervention

PubMed Central

Devine, Patricia G.; Forscher, Patrick S.; Austin, Anthony J.; Cox, William T. L.

2012-01-01

We developed a multi-faceted prejudice habit-breaking intervention to produce long-term reductions in implicit race bias. The intervention is based on the premise that implicit bias is like a habit that can be reduced through a combination of awareness of implicit bias, concern about the effects of that bias, and the application of strategies to reduce bias. In a 12-week longitudinal study, people who received the intervention showed dramatic reductions in implicit race bias. People who were concerned about discrimination or who reported using the strategies showed the greatest reductions. The intervention also led to increases in concern about discrimination and personal awareness of bias over the duration of the study. People in the control group showed none of the above effects. Our results raise the hope of reducing persistent and unintentional forms of discrimination that arise from implicit bias. PMID:23524616

Cell line specific modulation of connexin43 expression after exposure to ionizing radiation.

PubMed

Banaz-Yaşar, Ferya; Tischka, Rabea; Iliakis, George; Winterhager, Elke; Gellhaus, Alexandra

2005-01-01

Gap junctional intercellular communication plays a significant role in mediating radiation-induced bystander effects. However, the level of Cx43 itself is influenced by ionizing radiation, which could modify the bystander effect. Here we have investigated several cell lines for the modulation of Cx43 expression 24 h after irradiation with 5 Gy X-rays. The mouse endothelial cell line bEnd3 revealed a significantly elevated level of Cx43 already 15 min after exposure to X-rays, whereas human hybrid endothelial cells (EA.hy926) exhibited a transient downregulation of Cx43 mRNA. No obvious changes in the communication properties of the different cell lines could be observed after irradiation. The communication-deficient malignant human trophoblast cell line Jeg3 stably transfected with Cx43 did not reveal any induction of endogenous nor alteration in the exogenous Cx43 transcript level upon exposure to 5 Gy. Taken together, our data show a cell line specific modulation of Cx43 expression after exposure to X-rays.

The Effect of Implicit and Explicit Feedback: A Study on the Acquisition of Mandarin Classifiers by Chinese Heritage and Non-Heritage Language Learners

ERIC Educational Resources Information Center

Han, Ye

2010-01-01

Previous studies revealed mixed results in terms of the relative effects of implicit and explicit feedback: some found that explicit feedback worked more efficiently than implicit feedback; others found no difference between the two feedback types. These contrasting results called for further investigations into this issue, particularly examining…

Teachers as Bystanders: The Effect of Teachers' Perceptions on Reporting Bullying Behavior

ERIC Educational Resources Information Center

Uale, Beth P.

2010-01-01

This paper examines the role of educators as it relates to the reporting process of bullying incidents. Since bullying behaviors have negative effects on student health and educators have regular contact with students, this study looks at teacher perceptions of bullying behaviors and how these perceptions influence the reporting process. Using the…

Repeated evaluative pairings and evaluative statements: How effectively do they shift implicit attitudes?

PubMed

Kurdi, Benedek; Banaji, Mahzarin R

2017-02-01

Six experiments, involving a total of 6,492 participants, were conducted to investigate the relative effectiveness of repeated evaluative pairings (REP; exposure to category members paired with pleasant or unpleasant images), evaluative statements (ES; verbally signaling upcoming pairings without actual exposure), and their combination (ES + REP) in shifting implicit social and nonsocial attitudes. Learning modality (REP, ES, and ES + REP) was varied between participants and implicit attitudes were assessed using an Implicit Association Test (IAT). Study 1 (N = 675) used fictitious social groups (NIFFs and LAAPs), Study 2 (N = 1,034) used novel social groups (humans with long vs. square faces), Study 3 (N = 1,072) used nonsocial stimuli (squares vs. rectangles), and Study 4 (N = 848) and Study 5 (N = 958) used known social groups (young vs. elderly; American vs. foreign). ES were more effective than REP and no less superior than ES + REP in producing implicit attitude change. Results were robust across social and nonsocial domains and for known and novel groups. Study 6 (N = 1,905) eliminated time on intervention, levels of construal, and expectancy effects as possible explanations for these findings. Associative theories of implicit evaluation posit that implicit attitudes should shift piecemeal over time; yet, in these experiments, one-shot language-based learning led to larger shifts in implicit attitude than exposure to stimulus pairings. Moreover, the redundancy observed in REP + ES suggests that attitude acquisition from repeated pairings and evaluative instructions may rely on shared mental representations. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Penalties for Peer Sexual Harassment in an Academic Context: The Influence of Harasser Gender, Participant Gender, Severity of Harassment, and the Presence of Bystanders.

ERIC Educational Resources Information Center

Cummings, Kimberly M.; Armenta, Madeline

2002-01-01

Examined the impact of harasser gender, participant gender, and presence of bystanders on perceptions of penalty appropriateness for peer sexual harassment in college. Students responded to descriptions of potential sexual harassment between one college student and another and described the appropriate penalty. Participants were more likely to…

An Exploratory Analysis of College Students' Response and Reporting Behavior Regarding Intimate Partner Violence Victimization and Perpetration among Their Friends

ERIC Educational Resources Information Center

Branch, Kathryn A.; Richards, Tara N.; Dretsch, Elizabeth C.

2013-01-01

Over the last several decades, an extensive literature has documented the prevalence of dating violence on college campuses. As a result, initiatives to promote awareness of dating violence on college campuses have proliferated and models of "bystander intervention" have been developed. Bystander intervention asserts that by giving all…

Active Defending and Passive Bystanding Behavior in Bullying: The Role of Personal Characteristics and Perceived Peer Pressure

ERIC Educational Resources Information Center

Pozzoli, Tiziana; Gini, Gianluca

2010-01-01

This study examined the role of pro-victim attitudes, personal responsibility, coping responses to observations of bullying, and perceived peer normative pressure in explaining defending the victim and passive bystanding behavior in bullying. A total of 462 Italian early adolescents (mean age = 13.4 years, SD = 9 months) participated in the study.…

Bystanders Matter: Associations between Reinforcing, Defending, and the Frequency of Bullying Behavior in Classrooms

ERIC Educational Resources Information Center

Salmivalli, Christina; Voeten, Marinus; Poskiparta, Elisa

2011-01-01

This study investigated whether the bystanders' behaviors (reinforcing the bully vs. defending the victim) in bullying situations are related to the frequency of bullying in a classroom. The sample consisted of 6,764 primary school children from Grades 3 to 5 (9-11 years of age), who were nested within 385 classrooms in 77 schools. The students…

Sticks, Stones, and Stigma: Student Bystander Behavior in Response to Hearing the Word "Retard"

ERIC Educational Resources Information Center

Albert, Avery B.; Jacobs, Holly E.; Siperstein, Gary N.

2016-01-01

The present study explored the prevalence of the r-word in schools and students' bystander behavior in response to hearing the word. In total, 2,297 students from 12 high schools across the country participated in this study. Results revealed the r-word was used frequently among high school students, most often toward individuals without…

How Students' Perceptions of the School Climate Influence Their Choice to Upstand, Bystand, or Join Perpetrators of Bullying

ERIC Educational Resources Information Center

Ferráns, Silvia Diazgranados; Selman, Robert L.

2014-01-01

The authors of this article, Silvia Diazgranados Ferráns and Robert Selman, use an emergent framework to explore how the rules of the school culture at different perceived school climates affect early adolescents' decisions to upstand, bystand, or join the perpetrators when they witness peer aggression and bullying. Through a grounded theory…

Active Citizens, Good Citizens, and Insouciant Bystanders: The Educational Implications of Chinese University Students' Civic Participation via Social Networking

ERIC Educational Resources Information Center

Ke, Lin; Starkey, Hugh

2014-01-01

This virtual ethnographic study explores how Chinese university students use social network sites (SNSs) to participate in civic activities. An ideal of "active" citizens is contrasted with good citizens (Crick) and insouciant bystanders. We find that students engage with the civic issues embedded in everyday life; their online civic…

They Know I Saw It: Evaluation Apprehension and Diffusion of Responsibility in Bystander Reactions to a Violent Crime.

ERIC Educational Resources Information Center

Gottlieb, Avi; Schwartz, Shalom H.

Male and female bystanders witnessed a violent theft in the course of a bogus "ESP Experiment." In addition to the subjects' sex, two experimental manipulations were orthogonally crossed. The subject was either the only one to witness the emergency, or witnessed it with an additional participant (diffusion of responsibility), and the subject's…

Identifiable Images of Bystanders Extracted from Corneal Reflections

PubMed Central

Jenkins, Rob; Kerr, Christie

2013-01-01

Criminal investigations often use photographic evidence to identify suspects. Here we combined robust face perception and high-resolution photography to mine face photographs for hidden information. By zooming in on high-resolution face photographs, we were able to recover images of unseen bystanders from reflections in the subjects' eyes. To establish whether these bystanders could be identified from the reflection images, we presented them as stimuli in a face matching task (Experiment 1). Accuracy in the face matching task was well above chance (50%), despite the unpromising source of the stimuli. Participants who were unfamiliar with the bystanders' faces (n = 16) performed at 71% accuracy [t(15) = 7.64, p<.0001, d = 1.91], and participants who were familiar with the faces (n = 16) performed at 84% accuracy [t(15) = 11.15, p<.0001, d = 2.79]. In a test of spontaneous recognition (Experiment 2), observers could reliably name a familiar face from an eye reflection image. For crimes in which the victims are photographed (e.g., hostage taking, child sex abuse), reflections in the eyes of the photographic subject could help to identify perpetrators. PMID:24386177

Motivation modulates the effect of approach on implicit preferences.

PubMed

Zogmaister, Cristina; Perugini, Marco; Richetin, Juliette

2016-08-01

With three studies, we investigated whether motivational states can modulate the formation of implicit preferences. In Study 1, participants played a video game in which they repeatedly approached one of two similar beverages, while disregarding the other. A subsequent implicit preference for the target beverage emerged, which increased with participants' thirst. In Study 2, participants approached one brand of potato chips while avoiding the other: Conceptually replicating the moderation observed in Study 1, the implicit preference for the approached brand increased with the number of hours from last food intake. In Study 3, we experimentally manipulated hunger, and the moderation effect emerged again, with hungry participants displaying a higher implicit preference for the approached brand, as compared to satiated participants. In the three studies, the moderation effect was not paralleled in explicit preferences although the latter were affected by the preference inducing manipulation. Theoretical implications and open questions are discussed.

Examining the Presence, Consequences, and Reduction of Implicit Bias in Health Care: A Narrative Review

PubMed Central

Zestcott, Colin A.; Blair, Irene V.; Stone, Jeff

2016-01-01

Recent evidence suggests that one possible cause of disparities in health outcomes for stigmatized groups is the implicit biases held by health care providers. In response, several health care organizations have called for, and developed, new training in implicit bias for their providers. This review examines current evidence on the role that provider implicit bias may play in health disparities, and whether training in implicit bias can effectively reduce the biases that providers exhibit. Directions for future research on the presence and consequences of provider implicit bias, and best practices for training to reduce such bias, will be discussed. PMID:27547105

Overexpression of SKP2 Inhibits the Radiation-Induced Bystander Effects of Esophageal Carcinoma.

PubMed

Wang, Xiao-Chun; Zhang, Tie-Jun; Guo, Zi-Jian; Xiao, Chang-Yan; Ding, Xiao-Wen; Fang, Fang; Sheng, Wen-Tao; Shu, Xu; Li, Jue

2017-02-06

To investigate the effects of S-phase kinase protein 2 (SKP2) expression on the radiation induced bystander effect (RIBE) in esophageal cancer (EC) cells. Western blot was used to detect the levels of SKP2, Rad51, and Ku70 in EC cells. Positive transfection, RNAi, micronucleus (MN), and γ-H2AX focus formation assay were used to investigate the effects of SKP2 on RIBE induced by irradiated cells. We found a significant negative correlation between SKP2 expression and MN frequency ( p < 0.05) induced by RIBE. The results were further confirmed by positive transfection, RNAi, and rescue experiments.γ-H2AX focus formation assay results indicated that overexpression of SKP2 in the irradiated cells inhibited the DNA damage of RIBE cells. However, when SKP2 expression decreased in irradiated cells, the DNA damage of RIBE cells increased. Increased or decreased expression levels of SKP2 had effects on Rad51 expression under the conditions of RIBE. These results showed, for the first time, that SKP2 expression can inhibit RIBE of EC cells. The mechanism may function, at least partly, through the regulation of Rad51 in the ability to repair DNA damage.

The Effect of Testosterone Administration and Digit Ratio (2D:4D) on Implicit Preference for Status Goods in Healthy Males

PubMed Central

Wu, Yin; Zilioli, Samuele; Eisenegger, Christoph; Clark, Luke; Li, Hong

2017-01-01

Testosterone has been linked to social status seeking in humans. The present study investigated the effects of testosterone administration on implicit and explicit preferences for status goods in healthy male participants (n = 64), using a double-blind, placebo-controlled, between-subjects design. We also investigated the interactive effect between second-to-fourth digit ratio (2D:4D; i.e., a proximal index of prenatal testosterone) and testosterone treatment on status preferences. Results showed that testosterone administration has no discernable influence on self-reported willingness-to-pay (i.e., the explicit measure) or implicit attitudes towards status goods. Individuals with lower 2D:4D (i.e., more masculine) had more positive attitudes for high-status goods on an Implicit Association Task, and this association was abolished with testosterone administration. These data suggest interactive effects of acute testosterone administration and prenatal testosterone exposure on human social status seeking, and highlight the utility of implicit methods for measuring status-related behavior. PMID:29085287

Using aversive images to enhance healthy food choices and implicit attitudes: An experimental test of evaluative conditioning.

PubMed

Hollands, Gareth J; Prestwich, Andrew; Marteau, Theresa M

2011-03-01

To examine the effect of communicating images of energy-dense snack foods paired with aversive images of the potential health consequences of unhealthy eating, on implicit and explicit attitudes and food choice behavior. Participants were randomly allocated to either an evaluative conditioning (EC) procedure that paired images of snack foods with images of potential adverse health consequences or a control condition that featured images of snack foods alone. Implicit attitudes were assessed pre- and post-intervention. Explicit attitudes and food choice behavior were assessed post-intervention. The conditioning intervention made implicit attitudes toward energy-dense snacks more negative, with this effect greatest in those with relatively more favorable implicit attitudes toward these snacks at baseline. Participants in the conditioning intervention were more likely to choose fruit rather than snacks in a behavioral choice task, a relationship mediated by changes in implicit attitudes. Presenting aversive images of potential health consequences with those of specific foodstuffs can change implicit attitudes, which impacts on subsequent food choice behavior. (c) 2011 APA, all rights reserved

Absent bystanders and cognitive dissonance: a comment on Timmins & de Vries.

PubMed

Paley, John

2015-04-01

Timmins & de Vries are more sympathetic to my editorial than other critics, but they take issue with the details. They doubt whether the bystander phenomenon applies to Mid Staffs nurses; they believe that cognitive dissonance is a better explanation of why nurses fail to behave compassionately; and they think that I am 'perhaps a bit rash' to conclude that 'teaching compassion may be fruitless'. In this comment, I discuss all three points. I suggest that the bystander phenomenon is irrelevant; that Timmins & de Vries give an incomplete account of cognitive dissonance; and that it isn't rash to propose that educating nurses 'for compassion' is a red herring. Additionally, I comment on the idea that I wish to mount a 'defence of healthcare staff'. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of Visual Feedback Distortion on Gait Adaptation: Comparison of Implicit Visual Distortion Versus Conscious Modulation on Retention of Motor Learning.

PubMed

Kim, Seung-Jae; Ogilvie, Mitchell; Shimabukuro, Nathan; Stewart, Trevor; Shin, Joon-Ho

2015-09-01

Visual feedback can be used during gait rehabilitation to improve the efficacy of training. We presented a paradigm called visual feedback distortion; the visual representation of step length was manipulated during treadmill walking. Our prior work demonstrated that an implicit distortion of visual feedback of step length entails an unintentional adaptive process in the subjects' spatial gait pattern. Here, we investigated whether the implicit visual feedback distortion, versus conscious correction, promotes efficient locomotor adaptation that relates to greater retention of a task. Thirteen healthy subjects were studied under two conditions: (1) we implicitly distorted the visual representation of their gait symmetry over 14 min, and (2) with help of visual feedback, subjects were told to walk on the treadmill with the intent of attaining the gait asymmetry observed during the first implicit trial. After adaptation, the visual feedback was removed while subjects continued walking normally. Over this 6-min period, retention of preserved asymmetric pattern was assessed. We found that there was a greater retention rate during the implicit distortion trial than that of the visually guided conscious modulation trial. This study highlights the important role of implicit learning in the context of gait rehabilitation by demonstrating that training with implicit visual feedback distortion may produce longer lasting effects. This suggests that using visual feedback distortion could improve the effectiveness of treadmill rehabilitation processes by influencing the retention of motor skills.

Modeling stimulus variation in three common implicit attitude tasks.

PubMed

Wolsiefer, Katie; Westfall, Jacob; Judd, Charles M

2017-08-01

We explored the consequences of ignoring the sampling variation due to stimuli in the domain of implicit attitudes. A large literature in psycholinguistics has examined the statistical treatment of random stimulus materials, but the recommendations from this literature have not been applied to the social psychological literature on implicit attitudes. This is partly because of inherent complications in applying crossed random-effect models to some of the most common implicit attitude tasks, and partly because no work to date has demonstrated that random stimulus variation is in fact consequential in implicit attitude measurement. We addressed this problem by laying out statistically appropriate and practically feasible crossed random-effect models for three of the most commonly used implicit attitude measures-the Implicit Association Test, affect misattribution procedure, and evaluative priming task-and then applying these models to large datasets (average N = 3,206) that assess participants' implicit attitudes toward race, politics, and self-esteem. We showed that the test statistics from the traditional analyses are substantially (about 60 %) inflated relative to the more-appropriate analyses that incorporate stimulus variation. Because all three tasks used the same stimulus words and faces, we could also meaningfully compare the relative contributions of stimulus variation across the tasks. In an appendix, we give syntax in R, SAS, and SPSS for fitting the recommended crossed random-effects models to data from all three tasks, as well as instructions on how to structure the data file.

Cardiac arrests in schools: assessing use of automated external defibrillators (AED) on school campuses.

PubMed

Swor, Robert; Grace, Heather; McGovern, Heather; Weiner, Michelle; Walton, Edward

2013-04-01

Sudden cardiac arrest in schools are infrequent, but emotionally charged events. The purpose of our study was to: (1) describe characteristics and outcomes of school cardiac arrests; and (2) assess the feasibility of conducting school bystander interviews to describe the events surrounding cardiac arrests, assess AED availability and use, and identify barriers to AED use. We performed a telephone survey of bystanders to cardiac arrests occurring in K-12 schools in communities participating in the Cardiac Arrest Registry to Enhance Survival (CARES) database and a local cardiac arrest database. The study period was from 8/2005 to 8/2011 and continued in one community through 2011. Utstein style descriptive data and outcomes were collected. A structured telephone interview of a bystander or administrative personnel was conducted for each cardiac arrest event. We collected a descriptive event summary, including provision of bystander CPR, presence of an AED and information regarding AED deployment, training, and use and perceived barriers to AED use. Descriptive data are reported. During the study period there were 30,603 cardiac arrests identified at study communities, of which 47 (0.15%) events were at K-12 schools. Of these, 21 (45.7%) were at high schools, a minority (16, 34.0%) were children (

Survival After Application of Automatic External Defibrillators Before Arrival of the Emergency Medical System

PubMed Central

Weisfeldt, Myron L.; Sitlani, Colleen M.; Ornato, Joseph P.; Rea, Thomas; Aufderheide, Tom P.; Davis, Daniel; Dreyer, Jonathan; Hess, Erik P.; Jui, Jonathan; Maloney, Justin; Sopko, George; Powell, Judy; Nichol, Graham; Morrison, Laurie J.

2010-01-01

Objectives The purpose of this study was to assess the effectiveness of contemporary automatic external defibrillator (AED) use. Background In the PAD (Public Access Defibrillation) trial, survival was doubled by focused training of lay volunteers to use an AED in high-risk public settings. Methods We performed a population-based cohort study of persons with nontraumatic out-of-hospital cardiac arrest before emergency medical system (EMS) arrival at Resuscitation Outcomes Consortium (ROC) sites between December 2005 and May 2007. Multiple logistic regression was used to assess the independent association between AED application and survival to hospital discharge. Results Of 13,769 out-of-hospital cardiac arrests, 4,403 (32.0%) received bystander cardiopulmonary resuscitation but had no AED applied before EMS arrival, and 289 (2.1%) had an AED applied before EMS arrival. The AED was applied by health care workers (32%), lay volunteers (35%), police (26%), or unknown (7%). Overall survival to hospital discharge was 7%. Survival was 9% (382 of 4,403) with bystander cardiopulmonary resuscitation but no AED, 24% (69 of 289) with AED application, and 38% (64 of 170) with AED shock delivered. In multivariable analyses adjusting for: 1) age and sex; 2) bystander cardiopulmonary resuscitation performed; 3) location of arrest (public or private); 4) EMS response interval; 5) arrest witnessed; 6) initial shockable or not shockable rhythm; and 7) study site, AED application was associated with greater likelihood of survival (odds ratio: 1.75; 95% confidence interval: 1.23 to 2.50; p < 0.002). Extrapolating this greater survival from the ROC EMS population base (21 million) to the population of the U.S. and Canada (330 million), AED application by bystanders seems to save 474 lives/year. Conclusions Application of an AED in communities is associated with nearly a doubling of survival after out-of-hospital cardiac arrest. These results reinforce the importance of strategically expanding community-based AED programs. PMID:20394876

Quality of audio-assisted versus video-assisted dispatcher-instructed bystander cardiopulmonary resuscitation: A systematic review and meta-analysis.

PubMed

Lin, Yu-You; Chiang, Wen-Chu; Hsieh, Ming-Ju; Sun, Jen-Tang; Chang, Yi-Chung; Ma, Matthew Huei-Ming

2018-02-01

This study aimed to conduct a systematic review and meta-analysis comparing the effect of video-assistance and audio-assistance on quality of dispatcher-instructed cardiopulmonary resuscitation (DI-CPR) for bystanders. Five databases were searched, including PubMed, Cochrane library, Embase, Scopus and NIH clinical trial, to find randomized control trials published before June 2017. Qualitative analysis and meta-analysis were undertaken to examine the difference between the quality of video-instructed and audio-instructed dispatcher-instructed bystander CPR. The database search yielded 929 records, resulting in the inclusion of 9 relevant articles in this study. Of these, 6 were included in the meta-analysis. Initiation of chest compressions was slower in the video-instructed group than in the audio-instructed group (median delay 31.5 s; 95% CI: 10.94-52.09). The difference in the number of chest compressions per minute between the groups was 19.9 (95% CI: 10.50-29.38) with significantly faster compressions in the video-instructed group than in the audio-instructed group (104.8 vs. 80.6). The odds ratio (OR) for correct hand positioning was 0.8 (95% CI: 0.53-1.30) when comparing the audio-instructed and video-instructed groups. The differences in chest compression depth (mm) and time to first ventilation (seconds) between the video-instructed group and audio-instructed group were 1.6 mm (95% CI: -8.75, 5.55) and 7.5 s (95% CI: -56.84, 71.80), respectively. Video-instructed DI-CPR significantly improved the chest compression rate compared to the audio-instructed method, and a trend for correctness of hand position was also observed. However, this method caused a delay in the commencement of bystander-initiated CPR in the simulation setting. Copyright © 2017 Elsevier B.V. All rights reserved.

Not explicit but implicit memory is influenced by individual perception style

PubMed Central

Tsushima, Yoshiaki

2018-01-01

Not only explicit but also implicit memory has considerable influence on our daily life. However, it is still unclear whether explicit and implicit memories are sensitive to individual differences. Here, we investigated how individual perception style (global or local) correlates with implicit and explicit memory. As a result, we found that not explicit but implicit memory was affected by the perception style: local perception style people more greatly used implicit memory than global perception style people. These results help us to make the new effective application adapting to individual perception style and understand some clinical symptoms such as autistic spectrum disorder. Furthermore, this finding might give us new insight of memory involving consciousness and unconsciousness as well as relationship between implicit/explicit memory and individual perception style. PMID:29370212

Not explicit but implicit memory is influenced by individual perception style.

PubMed

Hine, Kyoko; Tsushima, Yoshiaki

2018-01-01

Not only explicit but also implicit memory has considerable influence on our daily life. However, it is still unclear whether explicit and implicit memories are sensitive to individual differences. Here, we investigated how individual perception style (global or local) correlates with implicit and explicit memory. As a result, we found that not explicit but implicit memory was affected by the perception style: local perception style people more greatly used implicit memory than global perception style people. These results help us to make the new effective application adapting to individual perception style and understand some clinical symptoms such as autistic spectrum disorder. Furthermore, this finding might give us new insight of memory involving consciousness and unconsciousness as well as relationship between implicit/explicit memory and individual perception style.

Influence of Psychological and Social Factors on Bystanders' Roles in School Bullying among Korean-American Students in the United States

ERIC Educational Resources Information Center

Choi, Sumi; Cho, Young Il

2013-01-01

This study investigated the associations of psychological and social variables with the likelihood of exhibiting three different behaviors as a bystander in a bullying situation. The sample comprised 238 Korean-American and Korean students, from the 3rd to 12th grades, studying in the USA. Students receiving classmate support showed a lower…

Should I Say Something? Dating and Sexual Aggression Bystander Intervention among High School Youth. National Issue Brief Number 92

ERIC Educational Resources Information Center

Edwards, Katie M.; Eckstein, Robert P.; Rodenhizer-Stämpfli , Kara Anne

2015-01-01

Using data from a sample of 218 high school youth from three high schools in New England (one rural, two urban), this brief discusses dating and sexual aggression bystander intervention among high school youth. Authors Katie Edwards, Robert Eckstein, and Kara Anne Rodenhizer-Stämpfli report that an overwhelming majority (93.6 percent) of high…

Working memory moderates the effect of the integrative process of implicit and explicit autonomous motivation on academic achievement.

PubMed

Gareau, Alexandre; Gaudreau, Patrick

2017-11-01

In previous research, autonomous motivation (AM) has been found to be associated with school achievement, but the relation has been largely heterogeneous across studies. AM has typically been assessed with explicit measures such as self-report questionnaires. Recent self-determination theory (SDT) research has suggested that converging implicit and explicit measures can be taken to characterize the integrative process in SDT. Drawing from dual-process theories, we contended that explicit AM is likely to promote school achievement when it is part of an integrated cognitive system that combines easily accessible mental representations (i.e., implicit AM) and efficient executive functioning. A sample of 272 university students completed a questionnaire and a lexical decision task to assess their explicit and implicit AM, respectively, and they also completed working memory capacity measures. Grades were obtained at the end of the semester to examine the short-term prospective effect of implicit and explicit AM, working memory, and their interaction. Results of moderation analyses have provided support for a synergistic interaction in which the association between explicit AM and academic achievement was positive and significant only for individuals with high level of implicit AM. Moreover, working memory was moderating the synergistic effect of explicit and implicit AM. Explicit AM was positively associated with academic achievement for students with average-to-high levels of working memory capacity, but only if their motivation operated synergistically with high implicit AM. The integrative process thus seems to hold better proprieties for achievement than the sole effect of explicit AM. Implications for SDT are outlined. © 2017 The British Psychological Society.

Perceptual other-race training reduces implicit racial bias.

PubMed

Lebrecht, Sophie; Pierce, Lara J; Tarr, Michael J; Tanaka, James W

2009-01-01

Implicit racial bias denotes socio-cognitive attitudes towards other-race groups that are exempt from conscious awareness. In parallel, other-race faces are more difficult to differentiate relative to own-race faces--the "Other-Race Effect." To examine the relationship between these two biases, we trained Caucasian subjects to better individuate other-race faces and measured implicit racial bias for those faces both before and after training. Two groups of Caucasian subjects were exposed equally to the same African American faces in a training protocol run over 5 sessions. In the individuation condition, subjects learned to discriminate between African American faces. In the categorization condition, subjects learned to categorize faces as African American or not. For both conditions, both pre- and post-training we measured the Other-Race Effect using old-new recognition and implicit racial biases using a novel implicit social measure--the "Affective Lexical Priming Score" (ALPS). Subjects in the individuation condition, but not in the categorization condition, showed improved discrimination of African American faces with training. Concomitantly, subjects in the individuation condition, but not the categorization condition, showed a reduction in their ALPS. Critically, for the individuation condition only, the degree to which an individual subject's ALPS decreased was significantly correlated with the degree of improvement that subject showed in their ability to differentiate African American faces. Our results establish a causal link between the Other-Race Effect and implicit racial bias. We demonstrate that training that ameliorates the perceptual Other-Race Effect also reduces socio-cognitive implicit racial bias. These findings suggest that implicit racial biases are multifaceted, and include malleable perceptual skills that can be modified with relatively little training.

Measuring implicit attitudes: A positive framing bias flaw in the Implicit Relational Assessment Procedure (IRAP).

PubMed

O'Shea, Brian; Watson, Derrick G; Brown, Gordon D A

2016-02-01

How can implicit attitudes best be measured? The Implicit Relational Assessment Procedure (IRAP), unlike the Implicit Association Test (IAT), claims to measure absolute, not just relative, implicit attitudes. In the IRAP, participants make congruent (Fat Person-Active: false; Fat Person-Unhealthy: true) or incongruent (Fat Person-Active: true; Fat Person-Unhealthy: false) responses in different blocks of trials. IRAP experiments have reported positive or neutral implicit attitudes (e.g., neutral attitudes toward fat people) in cases in which negative attitudes are normally found on explicit or other implicit measures. It was hypothesized that these results might reflect a positive framing bias (PFB) that occurs when participants complete the IRAP. Implicit attitudes toward categories with varying prior associations (nonwords, social systems, flowers and insects, thin and fat people) were measured. Three conditions (standard, positive framing, and negative framing) were used to measure whether framing influenced estimates of implicit attitudes. It was found that IRAP scores were influenced by how the task was framed to the participants, that the framing effect was modulated by the strength of prior stimulus associations, and that a default PFB led to an overestimation of positive implicit attitudes when measured by the IRAP. Overall, the findings question the validity of the IRAP as a tool for the measurement of absolute implicit attitudes. A new tool (Simple Implicit Procedure:SIP) for measuring absolute, not just relative, implicit attitudes is proposed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

To Be or Want to Be: Disentangling the Role of Actual versus Ideal Self in Implicit Self-Esteem

PubMed Central

De Houwer, Jan; De Raedt, Rudi

2014-01-01

A growing body of work suggests that both depressed and non-depressed individuals display implicit positivity towards the self. In the current study, we examined whether this positivity can be underpinned by two qualitatively distinct propositions related to actual (‘I am good’) or ideal (‘I want to be good’) self-esteem. Dysphoric and non-dysphoric participants completed a self-esteem Implicit Association Test (IAT) as well an Implicit Relational Assessment Procedure (IRAP) targeting their actual self-esteem and an IRAP targeting ideal self-esteem. Both groups demonstrated similar and positive IAT effects. A more complex picture emerged with regard to the IRAP effects. Whereas non-dysphorics did not differ in their actual and ideal self-esteem, their dysphoric counterparts demonstrated lower actual than ideal self-esteem. Our results suggest that closer attention to the role of propositional processes in implicit measures may unlock novel insight into the relationship between implicit self-esteem and depression. PMID:25268889

Implicit theories of body weight: entity beliefs can weigh you down.

PubMed

Burnette, Jeni L

2010-03-01

The current research extended the implicit theory approach to a weight management context and merged it with value expectancy theory. Three studies investigated the hypothesis that individuals are especially unlikely to self-regulate effectively after dieting setbacks when they believe body weight to be fixed (entity theory) rather than malleable (incremental theory). Study 1 examined avoidant coping after a hypothetical dieting setback. Study 2 examined the implicit theory-avoidant coping relation after naturally occurring challenges to participants' weight-loss goals. Across both studies, entity theorists, relative to incremental theorists, reported more avoidant coping after setbacks. In Study 2, avoidant coping, in turn, predicted difficulty achieving weight-loss success. Study 3 manipulated implicit theories of weight to test the causal effects of implicit theories on effortful regulation. Entity theorists, relative to incremental theorists, reported less persistence following setbacks. Across the three studies, expectations about the potential for future dieting success mediated the link between implicit theory and self-regulation.

Is homophobia associated with an implicit same-sex attraction?

PubMed

Macinnis, Cara C; Hodson, Gordon

2013-01-01

Some theorists propose that homophobia stems from underlying same-sex attraction. A few studies have tested this hypothesis, yet without a clear measure of implicit sexual attraction, producing mixed results. For the first time, we test this attraction-based account of homophobia among both men and women using an implicit measure of sexual attraction. No evidence of an attraction-based account of homophobia emerged. Instead, implicit same-sex attraction was related to positive evaluations of gay men and lesbians among female participants. Even in targeted analyses examining the relation between implicit same-sex attraction and homosexual evaluations among only those theoretically most likely to demonstrate an attraction-based homophobic effect, implicit same-sex attraction was not associated with evaluations of homosexuals or was associated with more positive evaluations of homosexuals. In addition, explicit same-sex attraction was related to positive evaluations of gay men and lesbians for male participants. These results are more in keeping with the attitude-similarity effect (i.e., people like, rather than dislike, similar others).

Mobile-phone dispatch of laypersons for CPR in out-of-hospital cardiac arrest.

PubMed

Ringh, Mattias; Rosenqvist, Mårten; Hollenberg, Jacob; Jonsson, Martin; Fredman, David; Nordberg, Per; Järnbert-Pettersson, Hans; Hasselqvist-Ax, Ingela; Riva, Gabriel; Svensson, Leif

2015-06-11

Cardiopulmonary resuscitation (CPR) performed by bystanders is associated with increased survival rates among persons with out-of-hospital cardiac arrest. We investigated whether rates of bystander-initiated CPR could be increased with the use of a mobile-phone positioning system that could instantly locate mobile-phone users and dispatch lay volunteers who were trained in CPR to a patient nearby with out-of-hospital cardiac arrest. We conducted a blinded, randomized, controlled trial in Stockholm from April 2012 through December 2013. A mobile-phone positioning system that was activated when ambulance, fire, and police services were dispatched was used to locate trained volunteers who were within 500 m of patients with out-of-hospital cardiac arrest; volunteers were then dispatched to the patients (the intervention group) or not dispatched to them (the control group). The primary outcome was bystander-initiated CPR before the arrival of ambulance, fire, and police services. A total of 5989 lay volunteers who were trained in CPR were recruited initially, and overall 9828 were recruited during the study. The mobile-phone positioning system was activated in 667 out-of-hospital cardiac arrests: 46% (306 patients) in the intervention group and 54% (361 patients) in the control group. The rate of bystander-initiated CPR was 62% (188 of 305 patients) in the intervention group and 48% (172 of 360 patients) in the control group (absolute difference for intervention vs. control, 14 percentage points; 95% confidence interval, 6 to 21; P<0.001). A mobile-phone positioning system to dispatch lay volunteers who were trained in CPR was associated with significantly increased rates of bystander-initiated CPR among persons with out-of-hospital cardiac arrest. (Funded by the Swedish Heart-Lung Foundation and Stockholm County; ClinicalTrials.gov number, NCT01789554.).

Uninfected Bystander Cells Impact the Measurement of HIV-Specific Antibody-Dependent Cellular Cytotoxicity Responses

PubMed Central

Richard, Jonathan; Prévost, Jérémie; Baxter, Amy E.; Ding, Shilei; Medjahed, Halima; Delgado, Gloria G.; Brassard, Nathalie; Stürzel, Christina M.; Kirchhoff, Frank; Hahn, Beatrice H.; Parsons, Matthew S.; Kaufmann, Daniel E.; Evans, David T.

2018-01-01

ABSTRACT The conformation of the HIV-1 envelope glycoprotein (Env) substantially impacts antibody recognition and antibody-dependent cellular cytotoxicity (ADCC) responses. In the absence of the CD4 receptor at the cell surface, primary Envs sample a “closed” conformation that occludes CD4-induced (CD4i) epitopes. The virus controls CD4 expression through the actions of Nef and Vpu accessory proteins, thus protecting infected cells from ADCC responses. However, gp120 shed from infected cells can bind to CD4 present on uninfected bystander cells, sensitizing them to ADCC mediated by CD4i antibodies (Abs). Therefore, we hypothesized that these bystander cells could impact the interpretation of ADCC measurements. To investigate this, we evaluated the ability of antibodies to CD4i epitopes and broadly neutralizing Abs (bNAbs) to mediate ADCC measured by five ADCC assays commonly used in the field. Our results indicate that the uninfected bystander cells coated with gp120 are efficiently recognized by the CD4i ligands but not the bNabs. Consequently, the uninfected bystander cells substantially affect in vitro measurements made with ADCC assays that fail to identify responses against infected versus uninfected cells. Moreover, using an mRNA flow technique that detects productively infected cells, we found that the vast majority of HIV-1-infected cells in in vitro cultures or ex vivo samples from HIV-1-infected individuals are CD4 negative and therefore do not expose significant levels of CD4i epitopes. Altogether, our results indicate that ADCC assays unable to differentiate responses against infected versus uninfected cells overestimate responses mediated by CD4i ligands. PMID:29559570

Radiation damage and radioprotectants: new concepts in the era of molecular medicine

PubMed Central

Koukourakis, M I

2012-01-01

Exposure to ionising radiation results in mutagenesis and cell death, and the clinical manifestations depend on the dose and the involved body area. Reducing carcinogenesis in patients treated with radiotherapy, exposed to diagnostic radiation or who are in certain professional groups is mandatory. The prevention or treatment of early and late radiotherapy effects would improve quality of life and increase cancer curability by intensifying therapies. Experimental and clinical data have given rise to new concepts and a large pool of chemical and molecular agents that could be effective in the protection and treatment of radiation damage. To date, amifostine is the only drug recommended as an effective radioprotectant. This review identifies five distinct types of radiation damage (I, cellular depletion; II, reactive gene activation; III, tissue disorganisation; IV, stochastic effects; V, bystander effects) and classifies the radioprotective agents into five relevant categories (A, protectants against all types of radiation effects; B, death pathway modulators; C, blockers of inflammation, chemotaxis and autocrine/paracrine pathways; D, antimutagenic keepers of genomic integrity; E, agents that block bystander effects). The necessity of establishing and funding central committees that guide systematic clinical research into evaluating the novel agents revealed in the era of molecular medicine is stressed. PMID:22294702

Effects of Grading Leniency and Low Workload on Students' Evaluations of Teaching: Popular Myth, Bias, Validity, or Innocent Bystanders?

ERIC Educational Resources Information Center

Marsh, Herbert W.; Roche, Lawrence A.

2000-01-01

Discusses two studies that debunk the popular myths that student evaluations of teaching (SETs) are substantially biased by low workload and grading leniency. Results imply teaching effects were related to SETs. Contrary to predictions workload, expected grades, and their relations to SETs were stable over 12 years. (Author/MKA)

Effects of Age, Gender, School Class on Cardiopulmonary Resuscitation Skills of Nigerian Secondary School Students

ERIC Educational Resources Information Center

Onyeaso, Adedamola Olutoyin; Onyeaso, Chukwudi Ochi

2016-01-01

Background: The need for training of schoolchildren on cardiopulmonary resuscitation (CPR) as potential bystander CPR providers is growing globally but Nigeria is still behind and lacks basic necessary data. Purpose: The purpose of this study was to investigate the effects of age, gender and school class on CPR skills of Nigerian secondary school…

The mere exposure effect is sensitive to color information: evidence for color effects in a perceptual implicit memory test.

PubMed

Hupbach, Almut; Melzer, André; Hardt, Oliver

2006-01-01

Priming effects in perceptual tests of implicit memory are assumed to be perceptually specific. Surprisingly, changing object colors from study to test did not diminish priming in most previous studies. However, these studies used implicit tests that are based on object identification, which mainly depends on the analysis of the object shape and therefore operates color-independently. The present study shows that color effects can be found in perceptual implicit tests when the test task requires the processing of color information. In Experiment 1, reliable color priming was found in a mere exposure design (preference test). In Experiment 2, the preference test was contrasted with a conceptually driven color-choice test. Altering the shape of object from study to test resulted in significant priming in the color-choice test but eliminated priming in the preference test. Preference judgments thus largely depend on perceptual processes. In Experiment 3, the preference and the color-choice test were studied under explicit test instructions. Differences in reaction times between the implicit and the explicit test suggest that the implicit test results were not an artifact of explicit retrieval attempts. In contrast with previous assumptions, it is therefore concluded that color is part of the representation that mediates perceptual priming.

Definitions of School Bullying in Taiwan: A Comparison of Multiple Perspectives

ERIC Educational Resources Information Center

Cheng, Ying-Yao; Chen, Li-Ming; Ho, Hsiao-Chi; Cheng, Chih-Ling

2011-01-01

Investigating teachers' and students' different definitions of school bullying is important for necessary prevention and effective intervention. This study compared definitions of bullying from the perspectives of bystanders, bullies, victims, and educators. A total of 1,558 secondary educators and students in Taiwan participated in this research,…

BYSTANDER EFFECTS, GENOMIC INSTABILITY, ADAPTIVE RESPONSE AND CANCER RISK ASSESSMENT FOR RADIATION AND CHEMICAL EXPOSURES

EPA Science Inventory

There is an increased interest in utilizing mechanistic data in support of the cancer risk assessment process for ionizing radiation and environmental chemical exposures. In this regard the use of biologically based dose-response models is particularly advocated. The aim is to pr...

Full versus divided attention and implicit memory performance.

PubMed

Wolters, G; Prinsen, A

1997-11-01

Effects of full and divided attention during study on explicit and implicit memory performance were investigated in two experiments. Study time was manipulated in a third experiment. Experiment 1 showed that both similar and dissociative effects can be found in the two kinds of memory test, depending on the difficulty of the concurrent tasks used in the divided-attention condition. In this experiment, however, standard implicit memory tests were used and contamination by explicit memory influences cannot be ruled out. Therefore, in Experiments 2 and 3 the process dissociation procedure was applied. Manipulations of attention during study and of study time clearly affected the controlled (explicit) memory component, but had no effect on the automatic (implicit) memory component. Theoretical implications of these findings are discussed.

The Association Between Implicit and Explicit Attitudes Toward Smoking and Support for Tobacco Control Measures

PubMed Central

Chassin, Laurie; Presson, Clark C.

2013-01-01

Introduction: This study examined the association between implicit and explicit attitudes toward smoking and support for tobacco control policies. Methods: Participants were from an ongoing longitudinal study of the natural history of smoking who also completed a web-based assessment of implicit attitudes toward smoking (N = 1,337). Multiple regression was used to test the association between covariates (sex, age, educational attainment, parent status, and smoking status), implicit attitude toward smoking, and explicit attitude toward smoking and support for tobacco control policies. The moderating effect of the covariates on the relation between attitudes and support for policies was also tested. Results: Females, those with higher educational attainment, parents, and nonsmokers expressed more support for tobacco control policy measures. For nonsmokers, only explicit attitude was significantly associated with support for policies. For smokers, both explicit and implicit attitudes were significantly associated with support. The effect of explicit attitude was stronger for those with lower educational attainment. Conclusions: Both explicit and implicit smoking attitudes are important for building support for tobacco control policies, particularly among smokers. More research is needed on how to influence explicit and implicit attitudes to inform policy advocacy campaigns. PMID:22581941

The association between implicit and explicit attitudes toward smoking and support for tobacco control measures.

PubMed

Macy, Jonathan T; Chassin, Laurie; Presson, Clark C

2013-01-01

This study examined the association between implicit and explicit attitudes toward smoking and support for tobacco control policies. Participants were from an ongoing longitudinal study of the natural history of smoking who also completed a web-based assessment of implicit attitudes toward smoking (N = 1,337). Multiple regression was used to test the association between covariates (sex, age, educational attainment, parent status, and smoking status), implicit attitude toward smoking, and explicit attitude toward smoking and support for tobacco control policies. The moderating effect of the covariates on the relation between attitudes and support for policies was also tested. Females, those with higher educational attainment, parents, and nonsmokers expressed more support for tobacco control policy measures. For nonsmokers, only explicit attitude was significantly associated with support for policies. For smokers, both explicit and implicit attitudes were significantly associated with support. The effect of explicit attitude was stronger for those with lower educational attainment. Both explicit and implicit smoking attitudes are important for building support for tobacco control policies, particularly among smokers. More research is needed on how to influence explicit and implicit attitudes to inform policy advocacy campaigns.

The Role of Individual Correlates and Class Norms in Defending and Passive Bystanding Behavior in Bullying: A Multilevel Analysis

ERIC Educational Resources Information Center

Pozzoli, Tiziana; Gini, Gianluca; Vieno, Alessio

2012-01-01

This study investigates possible individual and class correlates of defending and passive bystanding behavior in bullying, in a sample of 1,825 Italian primary school (mean age = 10 years 1 month) and middle school (mean age = 13 years 2 months) students. The findings of a series of multilevel regression models show that both individual (e.g.,…

Measuring automatic retrieval: a comparison of implicit memory, process dissociation, and speeded response procedures.

PubMed

Horton, Keith D; Wilson, Daryl E; Vonk, Jennifer; Kirby, Sarah L; Nielsen, Tina

2005-07-01

Using the stem completion task, we compared estimates of automatic retrieval from an implicit memory task, the process dissociation procedure, and the speeded response procedure. Two standard manipulations were employed. In Experiment 1, a depth of processing effect was found on automatic retrieval using the speeded response procedure although this effect was substantially reduced in Experiment 2 when lexical processing was required of all words. In Experiment 3, the speeded response procedure showed an advantage of full versus divided attention at study on automatic retrieval. An implicit condition showed parallel effects in each study, suggesting that implicit stem completion may normally provide a good estimate of automatic retrieval. Also, we replicated earlier findings from the process dissociation procedure, but estimates of automatic retrieval from this procedure were consistently lower than those from the speeded response procedure, except when conscious retrieval was relatively low. We discuss several factors that may contribute to the conflicting outcomes, including the evidence for theoretical assumptions and criterial task differences between implicit and explicit tests.

The Effects of Training Contingency Awareness During Attention Bias Modification on Learning and Stress Reactivity.

PubMed

Lazarov, Amit; Abend, Rany; Seidner, Shiran; Pine, Daniel S; Bar-Haim, Yair

2017-09-01

Current attention bias modification (ABM) procedures are designed to implicitly train attention away from threatening stimuli with the hope of reducing stress reactivity and anxiety symptoms. However, the mechanisms underlying effective ABM delivery are not well understood, with awareness of the training contingency suggested as one possible factor contributing to ABM efficacy. Here, 45 high-anxious participants were trained to divert attention away from threat in two ABM sessions. They were randomly assigned to one of three training protocols: an implicit protocol, comprising two standard implicit ABM training sessions; an explicit protocol, comprising two sessions with explicit instruction as to the attention training contingency; and an implicit-explicit protocol, in which participants were not informed of the training contingency in the first ABM session and informed of it at the start of the second session. We examined learning processes and stress reactivity following a stress-induction task. Results indicate that relative to implicit instructions, explicit instructions led to stronger learning during the first training session. Following rest, the explicit and implicit groups exhibited consolidation-related improvement in performance, whereas no such improvement was noted for the implicit-explicit group. Finally, although stress reactivity was reduced after training, contingency awareness did not yield a differential effect on stress reactivity measured using both self-reports and skin conductance, within and across sessions. These results suggest that explicit ABM administration leads to greater initial learning during the training protocol while not differing from standard implicit administration in terms of off-line learning and stress reactivity. Copyright © 2017. Published by Elsevier Ltd.

Enhanced cardiac perception is associated with increased susceptibility to framing effects.

PubMed

Sütterlin, Stefan; Schulz, Stefan M; Stumpf, Theresa; Pauli, Paul; Vögele, Claus

2013-07-01

Previous studies suggest in line with dual process models that interoceptive skills affect controlled decisions via automatic or implicit processing. The "framing effect" is considered to capture implicit effects of task-irrelevant emotional stimuli on decision-making. We hypothesized that cardiac awareness, as a measure of interoceptive skills, is positively associated with susceptibility to the framing effect. Forty volunteers performed a risky-choice framing task in which the effect of loss versus gain frames on decisions based on identical information was assessed. The results show a positive association between cardiac awareness and the framing effect, accounting for 24% of the variance in the framing effect. These findings demonstrate that good interoceptive skills are linked to poorer performance in risky choices based on ambivalent information when implicit bias is induced by task-irrelevant emotional information. These findings support a dual process perspective on decision-making and suggest that interoceptive skills mediate effects of implicit bias on decisions. Copyright © 2013 Cognitive Science Society, Inc.

Community matters: intimate partner violence among rural young adults.

PubMed

Edwards, Katie M; Mattingly, Marybeth J; Dixon, Kristiana J; Banyard, Victoria L

2014-03-01

Drawing on social disorganization theory, the current study examined the extent to which community-level poverty rates and collective efficacy influenced individual reports of intimate partner violence (IPV) perpetration, victimization, and bystander intervention among a sample of 178 young adults (18-24; 67.4% women) from 16 rural counties across the eastern US who completed an online survey that assessed demographic information, IPV perpetration, victimization, bystander intervention, and collective efficacy. We computed each county's poverty rate from the 2007-2011 American Community Survey. Generalized estimating equations demonstrated that after controlling for individual-level income status, community-level poverty positively predicted IPV victimization and perpetration for both men and women. Collective efficacy was inversely related to IPV victimization and perpetration for men; however, collective efficacy was unrelated to IPV victimization and perpetration for women. Whereas IPV bystander intervention was positively related to collective efficacy and inversely related to individual-level income status for both men and women, community-level poverty was unrelated to IPV bystander intervention for both men and women. Overall, these findings provide some support for social disorganization theory in explaining IPV among rural young adults, and underscore the importance of multi-level IPV prevention and intervention efforts focused around community-capacity building and enhancement of collective efficacy.

Classroom relationship qualities and social-cognitive correlates of defending and passive bystanding in school bullying in Sweden: A multilevel analysis.

PubMed

Thornberg, Robert; Wänström, Linda; Hong, Jun Sung; Espelage, Dorothy L

2017-08-01

Using the social-ecological and social cognitive theories as integrated guiding frameworks, the present study examined whether moral disengagement and defender self-efficacy at the individual level, and moral disengagement, quality of teacher-student relationships and quality of student-student relationships at the classroom level were associated with passive bystanding and defending in bullying situations. Participants were 900 Swedish students from 43 classrooms, ranging in age from 9 to 13years. Multilevel regression analyses revealed that passive reactions by bystanders were associated with greater moral disengagement and less defender self-efficacy. Defending, in turn, was associated with less moral disengagement and greater defender self-efficacy and classroom student-student relationship quality. Furthermore, students who scored high in moral disengagement were even less prone to defend victims when the classroom student-student relationship quality was low, but more prone to act as defenders when the classroom student-student relationship quality was high. In addition, the negative association between defender self-efficacy and passive bystanding was stronger both in classrooms with higher student-student relationship quality and in those with lower class moral disengagement. Implications for prevention are discussed. Copyright © 2017 Society for the Study of School Psychology. All rights reserved.

Third-party punishers are rewarded, but third-party helpers even more so.

PubMed

Raihani, Nichola J; Bshary, Redouan

2015-04-01

Punishers can benefit from a tough reputation, where future partners cooperate because they fear repercussions. Alternatively, punishers might receive help from bystanders if their act is perceived as just and other-regarding. Third-party punishment of selfish individuals arguably fits these conditions, but it is not known whether third-party punishers are rewarded for their investments. Here, we show that third-party punishers are indeed rewarded by uninvolved bystanders. Third parties were presented with the outcome of a dictator game in which the dictator was either selfish or fair and were allocated to one of three treatments in which they could choose to do nothing or (1) punish the dictator, (2) help the receiver, or (3) choose between punishment and helping, respectively. A fourth player (bystander) then sees the third-party's decision and could choose to reward the third party or not. Third parties that punished selfish dictators were more likely to be rewarded by bystanders than third parties that took no action in response to a selfish dictator. However, helpful third parties were rewarded even more than third-party punishers. These results suggest that punishment could in principle evolve via indirect reciprocity, but also provide insights into why individuals typically prefer to invest in positive actions. © 2015 The Author(s).

Coach Expectations About Off-Field Conduct and Bystander Intervention by U.S. College Football Players to Prevent Inappropriate Sexual Behavior.

PubMed

Kroshus, Emily; Paskus, Tom; Bell, Lydia

2015-09-21

The objective of the present study was to assess whether there is a positive association between expectations about off-field conduct set by the team coach and the likelihood that college football players intend to engage as prosocial bystanders in the prevention of what they consider to be inappropriate sexual behavior. In a sample of U.S. collegiate football players (N = 3,281), a path analysis model tested the association between coach expectations, perceived likelihood of discipline for off-field transgressions, and likelihood of intending to intervene to prevent inappropriate sexual behavior. Mediation of these relationships by the athlete's sense of exploitative entitlement and their attitudes about intervening were also assessed. Findings supported the hypothesized relationships, with expectations and discipline associated with bystander intentions both directly and indirectly through the mediating pathways of entitlement and attitudes about intervening. These findings provide evidence about the important role that sports team coaches can play in encouraging bystander intervention by clarifying expectations and consequences for conduct off the field of play. Athletic departments can provide a framework within which coaches are informed about the importance of setting and enforcing standards for off-field behavior, and are appropriately incentivized to do so. © The Author(s) 2015.

Changes of Explicit and Implicit Stigma in Medical Students during Psychiatric Clerkship.

PubMed

Wang, Peng-Wei; Ko, Chih-Hung; Chen, Cheng-Sheng; Yang, Yi-Hsin Connine; Lin, Huang-Chi; Cheng, Cheng-Chung; Tsang, Hin-Yeung; Wu, Ching-Kuan; Yen, Cheng-Fang

2016-04-01

This study examines the differences in explicit and implicit stigma between medical and non-medical undergraduate students at baseline; the changes of explicit and implicit stigma in medical undergraduate and non-medical undergraduate students after a 1-month psychiatric clerkship and 1-month follow-up period; and the differences in the changes of explicit and implicit stigma between medical and non-medical undergraduate students. Seventy-two medical undergraduate students and 64 non-medical undergraduate students were enrolled. All participants were interviewed at intake and after 1 month. The Taiwanese version of the Stigma Assessment Scale and the Implicit Association Test were used to measure the participants' explicit and implicit stigma. Neither explicit nor implicit stigma differed between two groups at baseline. The medical, but not the non-medical, undergraduate students had a significant decrease in explicit stigma during the 1-month period of follow-up. Neither the medical nor the non-medical undergraduate students exhibited a significant change in implicit stigma during the one-month of follow-up, however. There was an interactive effect between group and time on explicit stigma but not on implicit stigma. Explicit but not implicit stigma toward mental illness decreased in the medical undergraduate students after a psychiatric clerkship. Further study is needed to examine how to improve implicit stigma toward mental illness.

Attitudes toward Overweight Individuals among Fitness Center Employees: An Examination of Contextual Effects

ERIC Educational Resources Information Center

Dimmock, James A.; Hallett, Bree E.; Grove, J. Robert

2009-01-01

Our study assessed implicit and explicit evaluations of overweight individuals among a sample of fitness center employees (N = 70). Participants completed a general demographics questionnaire and an explicit, self-report Antifat Attitudes Test (AFAT). Participants also completed two Implicit Association Tests (IATs) to measure implicit attitudes…

Explicit and Implicit Learning: Exploring Their Simultaneity and Immediate Effectiveness

ERIC Educational Resources Information Center

Bell, Philippa K.

2017-01-01

Do adults learn the same syntactic second language (L2) form explicitly and implicitly simultaneously during meaning-based exposure, and does the type of learning (explicit and/or implicit) affect subsequent performance. In this study, 81 anglophones completed comprehension tasks providing incidental exposure to a semi-artificial language (English…

Implicit Relational Effects in Associative Recognition

ERIC Educational Resources Information Center

Algarabel, S.; Pitarque, A.; Combita, L. M.; Rodriguez, L. A.

2013-01-01

We study the contribution of implicit relatedness to associative recognition in two experiments. In the first experiment, we showed an implicit improvement in recognition when the stimulus elements of each word pair shared common letters and they were unpaired at test. Moreover, when asked to study the stimuli under divided attention, recollection…

Teaching about Implicit Prejudices and Stereotypes: A Pedagogical Demonstration

ERIC Educational Resources Information Center

Adams, Virgil H., III; Devos, Thierry; Rivera, Luis M.; Smith, Heather; Vega, Luis A.

2014-01-01

Social psychology instructors from five distinct state universities in California examined the effect of incorporating the implicit association test (IAT) in a teaching module on students' perceived knowledge of implicit biases and motivation to control prejudice. Students (N = 258) completed a knowledge survey on prejudice, stereotypes, and…

Dissociation between arithmetic relatedness and distance effects is modulated by task properties: an ERP study comparing explicit vs. implicit arithmetic processing.

PubMed

Avancini, Chiara; Galfano, Giovanni; Szűcs, Dénes

2014-12-01

Event-related potential (ERP) studies have detected several characteristic consecutive amplitude modulations in both implicit and explicit mental arithmetic tasks. Implicit tasks typically focused on the arithmetic relatedness effect (in which performance is affected by semantic associations between numbers) while explicit tasks focused on the distance effect (in which performance is affected by the numerical difference of to-be-compared numbers). Both task types elicit morphologically similar ERP waves which were explained in functionally similar terms. However, to date, the relationship between these tasks has not been investigated explicitly and systematically. In order to fill this gap, here we examined whether ERP effects and their underlying cognitive processes in implicit and explicit mental arithmetic tasks differ from each other. The same group of participants performed both an implicit number-matching task (in which arithmetic knowledge is task-irrelevant) and an explicit arithmetic-verification task (in which arithmetic knowledge is task-relevant). 129-channel ERP data differed substantially between tasks. In the number-matching task, the arithmetic relatedness effect appeared as a negativity over left-frontal electrodes whereas the distance effect was more prominent over right centro-parietal electrodes. In the verification task, all probe types elicited similar N2b waves over right fronto-central electrodes and typical centro-parietal N400 effects over central electrodes. The distance effect appeared as an early-rising, long-lasting left parietal negativity. We suggest that ERP effects in the implicit task reflect access to semantic memory networks and to magnitude discrimination, respectively. In contrast, effects of expectation violation are more prominent in explicit tasks and may mask more delicate cognitive processes. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Dissociation between arithmetic relatedness and distance effects is modulated by task properties: An ERP study comparing explicit vs. implicit arithmetic processing

PubMed Central

Avancini, Chiara; Galfano, Giovanni; Szűcs, Dénes

2014-01-01

Event-related potential (ERP) studies have detected several characteristic consecutive amplitude modulations in both implicit and explicit mental arithmetic tasks. Implicit tasks typically focused on the arithmetic relatedness effect (in which performance is affected by semantic associations between numbers) while explicit tasks focused on the distance effect (in which performance is affected by the numerical difference of to-be-compared numbers). Both task types elicit morphologically similar ERP waves which were explained in functionally similar terms. However, to date, the relationship between these tasks has not been investigated explicitly and systematically. In order to fill this gap, here we examined whether ERP effects and their underlying cognitive processes in implicit and explicit mental arithmetic tasks differ from each other. The same group of participants performed both an implicit number-matching task (in which arithmetic knowledge is task-irrelevant) and an explicit arithmetic-verification task (in which arithmetic knowledge is task-relevant). 129-channel ERP data differed substantially between tasks. In the number-matching task, the arithmetic relatedness effect appeared as a negativity over left-frontal electrodes whereas the distance effect was more prominent over right centro-parietal electrodes. In the verification task, all probe types elicited similar N2b waves over right fronto-central electrodes and typical centro-parietal N400 effects over central electrodes. The distance effect appeared as an early-rising, long-lasting left parietal negativity. We suggest that ERP effects in the implicit task reflect access to semantic memory networks and to magnitude discrimination, respectively. In contrast, effects of expectation violation are more prominent in explicit tasks and may mask more delicate cognitive processes. PMID:25450162

Implicit Learning in Science: Activating and Suppressing Scientific Intuitions to Enhance Conceptual Change

NASA Astrophysics Data System (ADS)

Wang, Jeremy Yi-Ming

This dissertation examines the thesis that implicit learning plays a role in learning about scientific phenomena, and subsequently, in conceptual change. Decades of research in learning science demonstrate that a primary challenge of science education is overcoming prior, naive knowledge of natural phenomena in order to gain scientific understanding. Until recently, a key assumption of this research has been that to develop scientific understanding, learners must abandon their prior scientific intuitions and replace them with scientific concepts. However, a growing body of research shows that scientific intuitions persist, even among science experts. This suggests that naive intuitions are suppressed, not supplanted, as learners gain scientific understanding. The current study examines two potential roles of implicit learning processes in the development of scientific knowledge. First, implicit learning is a source of cognitive structures that impede science learning. Second, tasks that engage implicit learning processes can be employed to activate and suppress prior intuitions, enhancing the likelihood that scientific concepts are adopted and applied. This second proposal is tested in two experiments that measure training-induced changes in intuitive and conceptual knowledge related to sinking and floating objects in water. In Experiment 1, an implicit learning task was developed to examine whether implicit learning can induce changes in performance on near and far transfer tasks. The results of this experiment provide evidence that implicit learning tasks activate and suppress scientific intuitions. Experiment 2 examined the effects of combining implicit learning with traditional, direct instruction to enhance explicit learning of science concepts. This experiment demonstrates that sequencing implicit learning task before and after direct instruction has different effects on intuitive and conceptual knowledge. Together, these results suggest a novel approach for enhancing learning for conceptual change in science education.

Small-Noise Analysis and Symmetrization of Implicit Monte Carlo Samplers

DOE PAGES

Goodman, Jonathan; Lin, Kevin K.; Morzfeld, Matthias

2015-07-06

Implicit samplers are algorithms for producing independent, weighted samples from multivariate probability distributions. These are often applied in Bayesian data assimilation algorithms. We use Laplace asymptotic expansions to analyze two implicit samplers in the small noise regime. Our analysis suggests a symmetrization of the algorithms that leads to improved implicit sampling schemes at a relatively small additional cost. Here, computational experiments confirm the theory and show that symmetrization is effective for small noise sampling problems.

Witnessed arrest, but not delayed bystander cardiopulmonary resuscitation improves prehospital cardiac arrest survival.

PubMed

Vukmir, R B

2004-05-01

This study correlated the effect of witnessing a cardiac arrest and instituting bystander CPR (ByCPR), as a secondary end point in a study evaluating the effect of bicarbonate on survival. This prospective, randomised, double blinded clinical intervention trial enrolled 874 prehospital cardiopulmonary arrest patients encountered in a prehospital urban, suburban, and rural regional emergency medical service (EMS) area. This group underwent conventional advanced cardiac life support intervention followed by empiric early administration of sodium bicarbonate (1 mEq/l), monitoring conventional resuscitation parameters. Survival was measured as presence of vital signs on emergency department (ED) arrival. Data were analysed using chi(2) with Pearson correlation and odds ratio where appropriate. The overall survival rate was 13.9% (110 of 792) of prehospital cardiac arrest patients. The mean (SD) time until provision of bystander cardiopulmonary resuscitation (ByCPR) by laymen was 2.08 (2.77) minutes, and basic life support (BLS) by emergency medical technicians was 6.62 (5.73) minutes. There was improved survival noted with witnessed cardiac arrest-a 2.2-fold increase in survival, 18.9% (76 of 402) versus 8.6% (27 of 315) compared with unwitnessed arrests (p<0.001) with a decreased risk ratio of mortality of 0.4534 (95% CI, 0.0857 to 0.1891). The presence of ByCPR occurred in 32% (228 of 716) of patients, but interestingly did not correlate with survival. The survival rate was 18.2% (33 of 181) if ByCPR was performed within two minutes and 12.8% (6 of 47), if performed >two minutes (p = 0.3752). Survival after prehospital cardiac arrest is more likely when witnessed, but not necessarily when ByCPR was performed by laymen.

Implicit and explicit processing in deep dyslexia: Semantic blocking as a test for failure of inhibition in the phonological output lexicon.

PubMed

Colangelo, Annette; Buchanan, Lori

2006-12-01

The failure of inhibition hypothesis posits a theoretical distinction between implicit and explicit access in deep dyslexia. Specifically, the effects of failure of inhibition are assumed only in conditions that have an explicit selection requirement in the context of production (i.e., aloud reading). In contrast, the failure of inhibition hypothesis proposes that implicit processing and explicit access to semantic information without production demands are intact in deep dyslexia. Evidence for intact implicit and explicit access requires that performance in deep dyslexia parallels that observed in neurologically intact participants on tasks based on implicit and explicit processes. In other words, deep dyslexics should produce normal effects in conditions with implicit task demands (i.e., lexical decision) and on tasks based on explicit access without production (i.e., forced choice semantic decisions) because failure of inhibition does not impact the availability of lexical information, only explicit retrieval in the context of production. This research examined the distinction between implicit and explicit processes in deep dyslexia using semantic blocking in lexical decision and forced choice semantic decisions as a test for the failure of inhibition hypothesis. The results of the semantic blocking paradigm support the distinction between implicit and explicit processing and provide evidence for failure of inhibition as an explanation for semantic errors in deep dyslexia.

The key to success in elite athletes? Explicit and implicit motor learning in youth elite and non-elite soccer players.

PubMed

Verburgh, L; Scherder, E J A; van Lange, P A M; Oosterlaan, J

2016-09-01

In sports, fast and accurate execution of movements is required. It has been shown that implicitly learned movements might be less vulnerable than explicitly learned movements to stressful and fast changing circumstances that exist at the elite sports level. The present study provides insight in explicit and implicit motor learning in youth soccer players with different expertise levels. Twenty-seven youth elite soccer players and 25 non-elite soccer players (aged 10-12) performed a serial reaction time task (SRTT). In the SRTT, one of the sequences must be learned explicitly, the other was implicitly learned. No main effect of group was found for implicit and explicit learning on mean reaction time (MRT) and accuracy. However, for MRT, an interaction was found between learning condition, learning phase and group. Analyses showed no group effects for the explicit learning condition, but youth elite soccer players showed better learning in the implicit learning condition. In particular, during implicit motor learning youth elite soccer showed faster MRTs in the early learning phase and earlier reached asymptote performance in terms of MRT. Present findings may be important for sports because children with superior implicit learning abilities in early learning phases may be able to learn more (durable) motor skills in a shorter time period as compared to other children.

Moderators of Implicit-Explicit Exercise Cognition Concordance.

PubMed

Berry, Tanya R; Rodgers, Wendy M; Markland, David; Hall, Craig R

2016-12-01

Investigating implicit-explicit concordance can aid in understanding underlying mechanisms and possible intervention effects. This research examined the concordance between implicit associations of exercise with health or appearance and related explicit motives. Variables considered as possible moderators were behavioral regulations, explicit attitudes, and social desirability. Participants (N = 454) completed measures of implicit associations of exercise with health and appearance and questionnaire measures of health and appearance motives, attitudes, social desirability, and behavioral regulations. Attitudes significantly moderated the relationship between implicit associations of exercise with health and health motives. Identified regulations significantly moderated implicit-explicit concordance with respect to associations with appearance. These results suggest that implicit and explicit exercise-related cognitions are not necessarily independent and their relationship to each other may be moderated by attitudes or some forms of behavioral regulation. Future research that takes a dual-processing approach to exercise behavior should consider potential theoretical moderators of concordance.

How Explicit and Implicit Test Instructions in an Implicit Learning Task Affect Performance

PubMed Central

Witt, Arnaud; Puspitawati, Ira; Vinter, Annie

2013-01-01

Typically developing children aged 5 to 8 years were exposed to artificial grammar learning. Following an implicit exposure phase, half of the participants received neutral instructions at test while the other half received instructions making a direct, explicit reference to the training phase. We first aimed to assess whether implicit learning operated in the two test conditions. We then evaluated the differential impact of age on learning performances as a function of test instructions. The results showed that performance did not vary as a function of age in the implicit instructions condition, while age effects emerged when explicit instructions were employed at test. However, performance was affected differently by age and the instructions given at test, depending on whether the implicit learning of short or long units was assessed. These results suggest that the claim that the implicit learning process is independent of age needs to be revised. PMID:23326409

Implicit Attitudes in Prosopagnosia

PubMed Central

Knutson, Kristine M.; DeTucci, Karen A.; Grafman, Jordan

2011-01-01

We studied a male with acquired prosopagnosia using a battery of implicit association tests (IATs) to investigate whether observing faces varying by social category would activate the patient’s implicit social biases. We also asked him to categorize faces explicitly by race, gender, and political party. The patient, G.B., was marginally slower to categorize black compared to white faces. He showed congruency effects in the race and celebrity IATs, but not in the gender or political IATs. These results indicate that G.B. possesses an implicit social sensitivity to certain facial stimuli despite an inability to overtly recognize familiar faces. The results demonstrate that social biases can be retrieved based on facial stimuli via pathways bypassing the fusiform gyri. Thus the IAT effect can be added to the list of covert recognition effects found in prosopagnosia. PMID:21414330

I can do that: the impact of implicit theories on leadership role model effectiveness.

PubMed

Hoyt, Crystal L; Burnette, Jeni L; Innella, Audrey N

2012-02-01

This research investigates the role of implicit theories in influencing the effectiveness of successful role models in the leadership domain. Across two studies, the authors test the prediction that incremental theorists ("leaders are made") compared to entity theorists ("leaders are born") will respond more positively to being presented with a role model before undertaking a leadership task. In Study 1, measuring people's naturally occurring implicit theories of leadership, the authors showed that after being primed with a role model, incremental theorists reported greater leadership confidence and less anxious-depressed affect than entity theorists following the leadership task. In Study 2, the authors demonstrated the causal role of implicit theories by manipulating participants' theory of leadership ability. They replicated the findings from Study 1 and demonstrated that identification with the role model mediated the relationship between implicit theories and both confidence and affect. In addition, incremental theorists outperformed entity theorists on the leadership task.

Implementation Intentions Reduce Implicit Stereotype Activation and Application.

PubMed

Rees, Heather Rose; Rivers, Andrew Michael; Sherman, Jeffrey W

2018-05-01

Research has found that implementation intentions, if-then action plans (e.g., "if I see a Black face, I will think safe"), reduce stereotyping on implicit measures. However, it is unknown by what process(es) implementation intentions reduce implicit stereotyping. The present research examines the effects of implementation intentions on stereotype activation (e.g., extent to which stereotypic information is accessible) and stereotype application (e.g., extent to which accessible stereotypes are applied in judgment). In addition, we assessed the efficiency of implementation intentions by manipulating cognitive resources (e.g., digit-span, restricted response window) while participants made judgments on an implicit stereotyping measure. Across four studies, implementation intentions reduced implicit stereotyping. This decrease in stereotyping was associated with reductions in both stereotype activation and application. In addition, these effects of implementation intentions were highly efficient and associated with reduced stereotyping even for groups for which people may have little practice inhibiting stereotypes (e.g., gender).

Video calls from lay bystanders to dispatch centers - risk assessment of information security.

PubMed

Bolle, Stein R; Hasvold, Per; Henriksen, Eva

2011-09-30

Video calls from mobile phones can improve communication during medical emergencies. Lay bystanders can be instructed and supervised by health professionals at Emergency Medical Communication Centers. Before implementation of video mobile calls in emergencies, issues of information security should be addressed. Information security was assessed for risk, based on the information security standard ISO/IEC 27005:2008. A multi-professional team used structured brainstorming to find threats to the information security aspects confidentiality, quality, integrity, and availability. Twenty security threats of different risk levels were identified and analyzed. Solutions were proposed to reduce the risk level. Given proper implementation, we found no risks to information security that would advocate against the use of video calls between lay bystanders and Emergency Medical Communication Centers. The identified threats should be used as input to formal requirements when planning and implementing video calls from mobile phones for these call centers.

Video calls from lay bystanders to dispatch centers - risk assessment of information security

PubMed Central

2011-01-01

Background Video calls from mobile phones can improve communication during medical emergencies. Lay bystanders can be instructed and supervised by health professionals at Emergency Medical Communication Centers. Before implementation of video mobile calls in emergencies, issues of information security should be addressed. Methods Information security was assessed for risk, based on the information security standard ISO/IEC 27005:2008. A multi-professional team used structured brainstorming to find threats to the information security aspects confidentiality, quality, integrity, and availability. Results Twenty security threats of different risk levels were identified and analyzed. Solutions were proposed to reduce the risk level. Conclusions Given proper implementation, we found no risks to information security that would advocate against the use of video calls between lay bystanders and Emergency Medical Communication Centers. The identified threats should be used as input to formal requirements when planning and implementing video calls from mobile phones for these call centers. PMID:21958387

[Effect of divided attention on explicit and implicit aspects of recall].

PubMed

Wippich, W; Schmitt, R; Mecklenbräuker, S

1989-01-01

If subjects have to form word images before spelling a word from the image, results of a repetition of the spelling test reveal a reliable priming effect: Old words can be spelled faster than comparable control words, reflecting a form of implicit memory. We investigated whether this kind of repetition priming remains stable under conditions of divided attention in the study phase. The subjects had to spell meaningful words, meaningless non-words, and non-words that were meaningful with a backward spelling direction (troper, for example). In the testing stage, recognition judgments as a form of explicit memory were required, too. Divided attention in the study phase had a negative effect on explicit memory, as revealed by performance on the recognition task, but had little effect on implicit memory, as revealed by performance on the repetition of the spelling test. A further dissociation between implicit and explicit memory showed up as meaningful words were recognized much better than non-words, whereas implicit memory was uninfluenced by the meaningfulness variable. The disadvantage of backward spellings was not reduced with non-words (like troper) spelled backwards. Finally, we analyzed the relations between spelling times and recognition judgments and found a pattern of dependency for non-words only. Generally, the results are discussed within processing-oriented approaches to implicit memory with a special emphasis on controversial findings concerning the role of attention in different expressions of memory.

Implicit associations and compensatory health beliefs in smokers: exploring their role for behaviour and their change through warning labels.

PubMed

Glock, Sabine; Müller, Barbara C N; Krolak-Schwerdt, Sabine

2013-11-01

Smokers might think that the negative effects of smoking can be compensated for by other behaviours, such as doing exercise or eating healthily. This phenomenon is known as compensatory health beliefs (CHBs). Graphic warning labels on cigarette packets emphasize the negative effects of smoking, which may impact CHBs. Research so far has assessed CHBs explicitly only via questionnaires, although implicit cognition might be an important factor in continuing to smoke. This study investigated the impact of graphic warning labels on CHBs, by testing CHBs both implicitly and explicitly. The study had a three-group experimental design. ANOVAs and multiple regression analyses were run on the results. We assessed explicit CHBs among non-smokers, smokers, and smokers confronted with graphic warning labels (N = 107; 47 females, 23.89 years old, 78 daily smokers). Implicit associations between smoking and CHB-specific behaviours (e.g., eating healthy food) were measured using a Single-Target Implicit Association Test. After the experiment, participants were able to choose between a healthy and unhealthy food reward. Non-smokers and smokers differed in explicit CHBs but not in implicit cognitions. Warning labels influenced implicit associations among smokers but did not affect explicit CHBs. Most interestingly, implicit associations and explicit CHBs predicted food choice and smoking among smokers not confronted with warning labels. Graphic warning labels could be used in interventions to inhibit automatic associations between smoking and healthy behaviours. Unlearning implicit cognitions might in turn affect explicit CHBs, thus decreasing their role in reducing the negative feelings caused by smoking. © 2013 The British Psychological Society.

The Effects of Implicit Instruction on Implicit and Explicit Knowledge Development

ERIC Educational Resources Information Center

Godfroid, Aline

2016-01-01

This study extends the evidence for implicit second language (L2) learning, which comes largely from (semi-)artificial language research, to German. Upper-intermediate L2 German learners were flooded with spoken exemplars of a difficult morphological structure, namely strong, vowel-changing verbs. Toward the end of exposure, the mandatory vowel…

Is Implicit Motor Learning Preserved after Stroke? A Systematic Review with Meta-Analysis

PubMed Central

Kal, E.; Winters, M.; van der Kamp, J.; Houdijk, H.; Groet, E.; van Bennekom, C.; Scherder, E.

2016-01-01

Many stroke patients experience difficulty with performing dual-tasks. A promising intervention to target this issue is implicit motor learning, as it should enhance patients’ automaticity of movement. Yet, although it is often thought that implicit motor learning is preserved post-stroke, evidence for this claim has not been systematically analysed yet. Therefore, we systematically reviewed whether implicit motor learning is preserved post-stroke, and whether patients benefit more from implicit than from explicit motor learning. We comprehensively searched conventional (MEDLINE, Cochrane, Embase, PEDro, PsycINFO) and grey literature databases (BIOSIS, Web of Science, OpenGrey, British Library, trial registries) for relevant reports. Two independent reviewers screened reports, extracted data, and performed a risk of bias assessment. Overall, we included 20 out of the 2177 identified reports that allow for a succinct evaluation of implicit motor learning. Of these, only 1 study investigated learning on a relatively complex, whole-body (balance board) task. All 19 other studies concerned variants of the serial-reaction time paradigm, with most of these focusing on learning with the unaffected hand (N = 13) rather than the affected hand or both hands (both: N = 4). Four of the 20 studies compared explicit and implicit motor learning post-stroke. Meta-analyses suggest that patients with stroke can learn implicitly with their unaffected side (mean difference (MD) = 69 ms, 95% CI[45.1, 92.9], p < .00001), but not with their affected side (standardized MD = -.11, 95% CI[-.45, .25], p = .56). Finally, implicit motor learning seemed equally effective as explicit motor learning post-stroke (SMD = -.54, 95% CI[-1.37, .29], p = .20). However, overall, the high risk of bias, small samples, and limited clinical relevance of most studies make it impossible to draw reliable conclusions regarding the effect of implicit motor learning strategies post-stroke. High quality studies with larger samples are warranted to test implicit motor learning in clinically relevant contexts. PMID:27992442

Implicit Age Cues in Resumes: Subtle Effects on Hiring Discrimination

PubMed Central

Derous, Eva; Decoster, Jeroen

2017-01-01

Anonymous resume screening, as assumed, does not dissuade age discriminatory effects. Building on job market signaling theory, this study investigated whether older applicants may benefit from concealing explicitly mentioned age signals on their resumes (date of birth) or whether more implicit/subtle age cues on resumes (older-sounding names/old-fashioned extracurricular activities) may lower older applicants’ hirability ratings. An experimental study among 610 HR professionals using a mixed factorial design showed hiring discrimination of older applicants based on implicit age cues in resumes. This effect was more pronounced for older raters. Concealing one’s date of birth led to overall lower ratings. Study findings add to the limited knowledge on the effects of implicit age cues on hiring discrimination in resume screening and the usefulness of anonymous resume screening in the context of age. Implications for research and practice are discussed. PMID:28848463

Effects of Attention and Levels of Processing on Explicit and Implicit Memory Function with Interesting and Uninteresting Tasks in University Students

NASA Astrophysics Data System (ADS)

Mahdavian, Alireza; Kormi-Nouri, Reza

This study aims to investigate the effect of attention and levels of processing on memory function and recalling words in two situations when students are interested in the subject and when they are not. This is an experimental study of 160 students conducted individually using a computer software. Results reveal focused attention, interest in the subject and deep processing caused the explicit memory to be at its highest level of functionality. On the contrary, shallow processing, divided attention and lack of interest in the subject plunged memory function into its lowest levels. Variables have different effects on attention, explicit and implicit memory. That is, interesting tasks with focused attention and deep processing have the highest effect on explicit memory in order. Also, interesting tasks, focused attention, respectively affect implicit memory. But level of processing does not affect implicit memory significantly.

Narrative Exemplars and the Celebrity Spokesperson in Lebanese Anti-Domestic Violence Public Service Announcements.

PubMed

El-Khoury, Jessica R; Shafer, Autumn

2016-08-01

Domestic violence is a worldwide epidemic. This study examines the effects of narrative exemplars and a celebrity spokesperson in anti-domestic violence ads on Lebanese college students' attitudes and beliefs towards domestic violence and whether these effects are impacted by personal experience. The practical significance is derived from the high prevalence of domestic violence internationally, making it important to find ways to effectively use media to address this health-related issue that has huge consequences for the individual and society. This study adds to the theoretical understanding of narrative persuasion and media effects. Results indicated that narrative exemplars in anti-domestic violence ads promoting bystander awareness and intervention were more beneficial for people without relevant experience compared to people who know someone affected by domestic violence. Anti-domestic violence ads without narrative exemplars, but that also featured an emotional self-efficacy appeal targeting bystanders, were more effective for participants who know someone who had experienced domestic violence compared to participants without relevant experience. The presence of a celebrity spokesperson elicited more positive attitudes about the ad than a noncelebrity, but failed to directly affect relevant anti-domestic violence attitudes or beliefs. These results highlight the significance of formative audience research in health communication message design.

Sexual Violence Prevention through Bystander Education: An Experimental Evaluation

ERIC Educational Resources Information Center

Banyard, Victoria L.; Moynihan, Mary M.; Plante, Elizabethe G.

2007-01-01

The current study used an experimental design to evaluate a sexual violence prevention program based on a community of responsibility model that teaches women and men how to intervene safely and effectively in cases of sexual violence before, during, and after incidents with strangers, acquaintances, or friends. It approaches both women and men as…

Using Children's Literature to Decrease Moral Disengagement and Victimization among Elementary School Students

ERIC Educational Resources Information Center

Wang, Cixin; Goldberg, Taryn S.

2017-01-01

Previous research has suggested that moral disengagement is strongly associated with bullying and bystander behavior. The current study evaluated the effectiveness of a 5-week classroom-wide bullying intervention, "The Bullying Literature Project-Moral Disengagement Version (BLP-MD)", on moral disengagement and bullying among elementary…

From Bystander to Ally: Transforming the District Human Resources Department

ERIC Educational Resources Information Center

Campbell, Christine; DeArmond, Michael; Schumwinger, Abigail

2004-01-01

Although policymakers and academics tend to overlook the behind-the-scenes role that district human resources (HR) departments play in education, the HR office's effect is far from small. HR departments determine whether qualified teacher candidates make it to the classroom, or slip through the cracks. They can help principals find teachers who…

Retention of Cardiopulmonary Resuscitation Skills in Nigerian Secondary School Students

ERIC Educational Resources Information Center

Onyeaso, Adedamola Olutoyin

2016-01-01

Background/Objective: For effective bystander cardiopulmonary resuscitation (CPR), retention of CPR skills after the training is central. The objective of this study was to find out how much of the CPR skills a group of Nigerian secondary school students would retain six weeks after their first exposure to the conventional CPR training. Materials…

Collateral Damage Related to Rape and Interpersonal Violence in Higher Education

ERIC Educational Resources Information Center

Jones, Dan L.

2014-01-01

Collegiate communities are often faced with difficult situations from sexual assault, rape, and other forms of interpersonal violence. These events are not only tragic or traumatic for the individuals involved but also have ripple effects and create collateral damage within the campus community. Many universities are instituting bystander training…

Promoting Positive Peer Relationships among Youths: A Study Examining the Effects of a Class-Wide Bullying Prevention Program

ERIC Educational Resources Information Center

Earhart, James Allen, Jr.

2011-01-01

Bullying in schools has revealed deleterious psychosocial consequences for bullies, victims, and bystanders. Programs aimed at preventing bullying have largely revealed limited positive outcomes. Efforts that have been associated with positive results have drawn from the social-ecological model, focusing on the constellation of individual…

The single category implicit association test as a measure of implicit social cognition.

PubMed

Karpinski, Andrew; Steinman, Ross B

2006-07-01

The Single Category Implicit Association Test (SC-IAT) is a modification of the Implicit Association Test that measures the strength of evaluative associations with a single attitude object. Across 3 different attitude domains--soda brand preferences, self-esteem, and racial attitudes--the authors found evidence that the SC-IAT is internally consistent and makes unique contributions in the ability to understand implicit social cognition. In a 4th study, the authors investigated the susceptibility of the SC-IAT to faking or self-presentational concerns. Once participants with high error rates were removed, no significant self-presentation effect was observed. These results provide initial evidence for the reliability and validity of the SC-IAT as an individual difference measure of implicit social cognition. Copyright 2006 APA, all rights reserved.

Implicit spiritual assessment: an alternative approach for assessing client spirituality.

PubMed

Hodge, David R

2013-07-01

To provide optimal services, a spiritual assessment is often administered to understand the intersection between clients' spirituality and service provision. Traditional assessment approaches, however, may be ineffective with clients who are uncomfortable with spiritual language or who are otherwise hesitant to discuss spirituality overtly. This article orients readers to an implicit spiritual assessment, an alternative approach that may be more valid with such clients. The process of administering an implicit assessment is discussed, sample questions are provided to help operationalize this approach, and suggestions are offered to integrate an implicit assessment with more traditional assessment approaches. By using terminology that is implicitly spiritual in nature, an implicit assessment enables practitioners to identify and operationalize dimensions of clients' experience that may be critical to effective service provision but would otherwise be overlooked.

Implicit measures: A normative analysis and review.

PubMed

De Houwer, Jan; Teige-Mocigemba, Sarah; Spruyt, Adriaan; Moors, Agnes

2009-05-01

Implicit measures can be defined as outcomes of measurement procedures that are caused in an automatic manner by psychological attributes. To establish that a measurement outcome is an implicit measure, one should examine (a) whether the outcome is causally produced by the psychological attribute it was designed to measure, (b) the nature of the processes by which the attribute causes the outcome, and (c) whether these processes operate automatically. This normative analysis provides a heuristic framework for organizing past and future research on implicit measures. The authors illustrate the heuristic function of their framework by using it to review past research on the 2 implicit measures that are currently most popular: effects in implicit association tests and affective priming tasks. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

The Cognitive and Behavioural Impact of Alcohol Promoting and Alcohol Warning Advertisements: An Experimental Study

PubMed Central

Brown, Kyle G.; Stautz, Kaidy; Hollands, Gareth J.; Winpenny, Eleanor M.; Marteau, Theresa M.

2016-01-01

Aims To assess the immediate effect of alcohol promoting and alcohol warning advertisements on implicit and explicit attitudes towards alcohol and on alcohol seeking behaviour. Methods We conducted a between-participants online experiment in which participants were randomly assigned to view one of three sets of advertisements: (a) alcohol promoting, (b) alcohol warning, or (c) unrelated to alcohol. A total of 373 participants (59.5% female) aged 18–40 (M = 28.03) living in the UK were recruited online through a research agency. Positive and negative implicit attitudes and explicit attitudes towards alcohol were assessed before and after advertisements were viewed. Alcohol seeking behaviour was measured by participants' choice of either an alcohol-related or non-alcohol-related voucher offered ostensibly as a reward for participation. Self-reported past week alcohol consumption was also recorded. Results There were no main effects on any of the outcome measures. In heavier drinkers, viewing alcohol promoting advertisements increased positive implicit attitudes (standardized beta = 0.15, P = 0.04) and decreased negative implicit attitudes (standardized beta = −0.17, P = 0.02). In heavier drinkers, viewing alcohol warning advertisements decreased negative implicit attitudes (standardized beta = −0.19, P = 0.01). Conclusions Viewing alcohol promoting advertisements has a cognitive impact on heavier drinkers, increasing positive and reducing negative implicit attitudes towards alcohol. Viewing alcohol warning advertisements reduces negative implicit attitudes towards alcohol in heavier drinkers, suggestive of a reactance effect. PMID:26391367

The Cognitive and Behavioural Impact of Alcohol Promoting and Alcohol Warning Advertisements: An Experimental Study.

PubMed

Brown, Kyle G; Stautz, Kaidy; Hollands, Gareth J; Winpenny, Eleanor M; Marteau, Theresa M

2016-05-01

To assess the immediate effect of alcohol promoting and alcohol warning advertisements on implicit and explicit attitudes towards alcohol and on alcohol seeking behaviour. We conducted a between-participants online experiment in which participants were randomly assigned to view one of three sets of advertisements: (a) alcohol promoting, (b) alcohol warning, or (c) unrelated to alcohol. A total of 373 participants (59.5% female) aged 18-40 (M = 28.03) living in the UK were recruited online through a research agency. Positive and negative implicit attitudes and explicit attitudes towards alcohol were assessed before and after advertisements were viewed. Alcohol seeking behaviour was measured by participants' choice of either an alcohol-related or non-alcohol-related voucher offered ostensibly as a reward for participation. Self-reported past week alcohol consumption was also recorded. There were no main effects on any of the outcome measures. In heavier drinkers, viewing alcohol promoting advertisements increased positive implicit attitudes (standardized beta = 0.15, P = 0.04) and decreased negative implicit attitudes (standardized beta = -0.17, P = 0.02). In heavier drinkers, viewing alcohol warning advertisements decreased negative implicit attitudes (standardized beta = -0.19, P = 0.01). Viewing alcohol promoting advertisements has a cognitive impact on heavier drinkers, increasing positive and reducing negative implicit attitudes towards alcohol. Viewing alcohol warning advertisements reduces negative implicit attitudes towards alcohol in heavier drinkers, suggestive of a reactance effect. © The Author 2015. Medical Council on Alcohol and Oxford University Press.

Real-time Molecular Study of Bystander Effects of Low dose Low LET radiation Using Living Cell Imaging and Nanoparticale Optics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Natarajan, Mohan; Xu, Nancy R; Mohan, Sumathy

2013-06-03

In this study two novel approaches are proposed to investigate precisely the low dose low LET radiation damage and its effect on bystander cells in real time. First, a flow shear model system, which would provide us a near in vivo situation where endothelial cells in the presence of extra cellular matrix experiencing continuous flow shear stress, will be used. Endothelial cells on matri-gel (simulated extra cellular matrix) will be subjected to physiological flow shear (that occurs in normal blood vessels). Second, a unique tool (Single nano particle/single live cell/single molecule microscopy and spectroscopy; Figure A) will be used tomore » track the molecular trafficking by single live cell imaging. Single molecule chemical microscopy allows one to single out and study rare events that otherwise might be lost in assembled average measurement, and monitor many target single molecules simultaneously in real-time. Multi color single novel metal nanoparticle probes allow one to prepare multicolor probes (Figure B) to monitor many single components (events) simultaneously and perform multi-complex analysis in real-time. These nano-particles resist to photo bleaching and hence serve as probes for unlimited timeframe of analysis. Single live cell microscopy allows one to image many single cells simultaneously in real-time. With the combination of these unique tools, we will be able to study under near-physiological conditions the cellular and sub-cellular responses (even subtle changes at one molecule level) to low and very low doses of low LET radiation in real time (milli-second or nano-second) at sub-10 nanometer spatial resolution. This would allow us to precisely identify, at least in part, the molecular mediators that are responsible of radiation damage in the irradiated cells and the mediators that are responsible for initiating the signaling in the neighboring cells. Endothelial cells subjected to flow shear (2 dynes/cm2 or 16 dynes/cm2) and exposed to 0.1, 1 and 10 cGy on coverslips will be examined for (a) low LET radiation-induced alterations of cellular function and its physiological relevance in real time; and (b) radiation damage triggered bystander effect on the neighboring unirradiated cells. First, to determine the low LET radiation induced alteration of cellular function we will examine: (i) the real time transformation of single membrane transporters in single living cells; (ii) the pump efficiency of membrane efflux pump of live cells in real time at the molecular level; (iii) the kinetics of single-ligand receptor interaction on single live cell surface (Figure C); and (iv) alteration in chromosome replication in living cell. Second, to study the radiation triggered bystander responses, we will examine one of the key signaling pathway i.e. TNF- alpha/NF-kappa B mediated signaling. TNF-alpha specific nano particle sensors (green) will be developed to detect the releasing dynamics, transport mechanisms and ligand-receptor binding on live cell surface in real time. A second sensor (blue) will be developed to simultaneously monitor the track of NF-kB inside the cell. The proposed nano-particle optics approach would complement our DOE funded study on biochemical mechanisms of TNF-alpha- NF-kappa B-mediated bystander effect.« less

Health Care Providers’ Implicit and Explicit Attitudes Toward Lesbian Women and Gay Men

PubMed Central

Riskind, Rachel G.; Nosek, Brian A.

2015-01-01

Objectives. We examined providers’ implicit and explicit attitudes toward lesbian and gay people by provider gender, sexual identity, and race/ethnicity. Methods. We examined attitudes toward heterosexual people versus lesbian and gay people in Implicit Association Test takers: 2338 medical doctors, 5379 nurses, 8531 mental health providers, 2735 other treatment providers, and 214 110 nonproviders in the United States and internationally between May 2006 and December 2012. We characterized the sample with descriptive statistics and calculated Cohen d, a standardized effect size measure, with 95% confidence intervals. Results. Among heterosexual providers, implicit preferences always favored heterosexual people over lesbian and gay people. Implicit preferences for heterosexual women were weaker than implicit preferences for heterosexual men. Heterosexual nurses held the strongest implicit preference for heterosexual men over gay men (Cohen d = 1.30; 95% confidence interval = 1.28, 1.32 among female nurses; Cohen d = 1.38; 95% confidence interval = 1.32, 1.44 among male nurses). Among all groups, explicit preferences for heterosexual versus lesbian and gay people were weaker than implicit preferences. Conclusions. Implicit preferences for heterosexual people versus lesbian and gay people are pervasive among heterosexual health care providers. Future research should investigate how implicit sexual prejudice affects care. PMID:26180976

Implicit attitudes towards homosexuality: reliability, validity, and controllability of the IAT.

PubMed

Banse, R; Seise, J; Zerbes, N

2001-01-01

Two experiments were conducted to investigate the psychometric properties of an Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998) that was adapted to measure implicit attitudes towards homosexuality. In a first experiment, the validity of the Homosexuality-IAT was tested using a known group approach. Implicit and explicit attitudes were assessed in heterosexual and homosexual men and women (N = 101). The results provided compelling evidence for the convergent and discriminant validity of the Homosexuality-IAT as a measure of implicit attitudes. No evidence was found for two alternative explanations of IAT effects (familiarity with stimulus material and stereotype knowledge). The internal consistency of IAT scores was satisfactory (alpha s > .80), but retest correlations were lower. In a second experiment (N = 79) it was shown that uninformed participants were able to fake positive explicit but not implicit attitudes. Discrepancies between implicit and explicit attitudes towards homosexuality could be partially accounted for by individual differences in the motivation to control prejudiced behavior, thus providing independent evidence for the validity of the implicit attitude measure. Neither explicit nor implicit attitudes could be changed by persuasive messages. The results of both experiments are interpreted as evidence for a single construct account of implicit and explicit attitudes towards homosexuality.

Exposure to graphic warning labels on cigarette packages: Effects on implicit and explicit attitudes towards smoking among young adults.

PubMed

Macy, Jonathan T; Chassin, Laurie; Presson, Clark C; Yeung, Ellen

2016-01-01

To test the effect of exposure to the US Food and Drug Administration's proposed graphic images with text warning statements for cigarette packages on implicit and explicit attitudes towards smoking. A two-session web-based study was conducted with 2192 young adults 18-25-years-old. During session one, demographics, smoking behaviour, and baseline implicit and explicit attitudes were assessed. Session two, completed on average 18 days later, contained random assignment to viewing one of three sets of cigarette packages, graphic images with text warnings, text warnings only, or current US Surgeon General's text warnings. Participants then completed post-exposure measures of implicit and explicit attitudes. ANCOVAs tested the effect of condition on the outcomes, controlling for baseline attitudes. Smokers who viewed packages with graphic images plus text warnings demonstrated more negative implicit attitudes compared to smokers in the other conditions (p = .004). For the entire sample, explicit attitudes were more negative for those who viewed graphic images plus text warnings compared to those who viewed current US Surgeon General's text warnings (p = .014), but there was no difference compared to those who viewed text-only warnings. Graphic health warnings on cigarette packages can influence young adult smokers' implicit attitudes towards smoking.

Dynamic Exposure to Alcohol Advertising in a Sports Context Influences Implicit Attitudes.

PubMed

Zerhouni, Oulmann; Bègue, Laurent; Duke, Aaron A; Flaudias, Valentin

2016-02-01

Experimental studies investigating the impact of advertising with ecological stimuli on alcohol-related cognition are scarce. This research investigated the cognitive processes involved in learning implicit attitudes toward alcohol after incidental exposure to alcohol advertisements presented in a dynamic context. We hypothesized that incidental exposure to a specific alcohol brand would lead to heightened positive implicit attitudes toward alcohol due to a mere exposure effect. In total, 108 participants were randomly exposed to dynamic sporting events excerpts with and without advertising for a specific brand of alcohol, after completing self-reported measures of alcohol-related expectancies, alcohol consumption, and attitudes toward sport. Participants then completed a lexical decision task and an affective priming task. We showed that participants were faster to detect brand name after being exposed to advertising during a sports game, and that implicit attitudes of participants toward the brand were more positive after they were exposed to advertising, even when alcohol usage patterns were controlled for. Incidental exposure to alcohol sponsorship in sport events impacts implicit attitudes toward the advertised brand and alcohol in general. The effect of incidental advertising on implicit attitudes is also likely to be due to a mere exposure effect. However, further studies should address this point specifically. Copyright © 2016 by the Research Society on Alcoholism.

Ethnic identity and paranoid thinking: Implicit out-group preference and language dominance predict paranoia in Emirati women.

PubMed

Thomas, Justin; Bentall, Richard P; Hadden, Lowri; O'Hara, Lily

2017-09-01

Psychotic experiences including persecutory beliefs are elevated among immigrant and minority populations, especially when living in low ethnic density neighbourhoods (the ethnic density effect). Discrimination, victimization and experiencing a sense of 'not belonging' are hypothesized to play a role in this effect. Because a secure ethnic identity protects against poor self-esteem it may also protect against paranoia. This study explores the relationship between language proficiency (Arabic/English), in-group identity (implicit and explicit) and paranoia in female Emirati university students. Female citizens of the United Arab Emirates (UAE), Emirati college women (N = 208), reported English/Arabic language proficiencies, and performed a computerized affective priming task engineered to implicitly assess in-group (Emirati) versus out-group (American) positivity. Participants also completed self-report measures of in-group identity (MIIS), and paranoia (PaDs). Arabic proficiency was negatively correlated with paranoia, as was implicit in-group positivity. Furthermore, participants reporting English language dominance, and those demonstrating an implicit out-group preference, reported the highest levels of paranoia. The study is limited by its use of an all female sample. Implicit in-group attitudes and linguistic competence protect against paranoia and may help to explain the ethnic density effect. Copyright © 2016 Elsevier Ltd. All rights reserved.

Prehospital deaths from trauma: Are injuries survivable and do bystanders help?

PubMed

Oliver, G J; Walter, D P; Redmond, A D

2017-05-01

Deaths from trauma occurring in the prehospital phase of care are typically excluded from analysis in trauma registries. A direct historical comparison with Hussain and Redmond's study on preventable prehospital trauma deaths has shown that, two decades on, the number of potentially preventable deaths remains high. Using updated methodology, we aimed to determine the current nature, injury severity and survivability of traumatic prehospital deaths and to ascertain the presence of bystanders and their role following the point of injury including the frequency of first-aid delivery. We examined the Coroners' inquest files for deaths from trauma, occurring in the prehospital phase, over a three-year period in the Cheshire and Manchester (City), subsequently referred to as Manchester, Coronial jurisdictions. Injuries were scored using the Abbreviated-Injury-Scale (AIS-2008), Injury Severity Score (ISS) calculated and probability of survival estimated using the Trauma Audit and Research Network's outcome prediction model. One hundred and seventy-eight deaths were included in the study (one hundred and thirty-four Cheshire, forty-four Manchester). The World Health Organisation's recommendations consider those with a probability of survival between 25-50% as potentially preventable and those above 50% as preventable. The median ISS was 29 (Cheshire) and 27.5 (Manchester) with sixty-two (46%) and twenty-six (59%) respectively having a probability of survival in the potentially preventable and preventable ranges. Bystander presence during or immediately after the point of injury was 45% (Cheshire) and 39% (Manchester). Bystander intervention of any kind was 25% and 30% respectively. Excluding those found dead and those with a probability of survival less than 25%, bystanders were present immediately after the point of injury or "within minutes" in thirty-three of thirty-five (94%) Cheshire and ten of twelve (83%) Manchester. First aid of any form was attempted in fourteen of thirty-five (40%) and nine of twelve (75%) respectively. A high number of prehospital deaths from trauma occur with injuries that are potentially survivable, yet first aid intervention is infrequent. Following injury there is a potential window of opportunity for the provision of bystander assistance, particularly in the context of head injury, for simple first-aid manoeuvres to save lives. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.