Thesis (M.S. in molecular biosciences)--Washington State University, May 2010. / Title from PDF title page (viewed on July 9, 2010). "School of Molecular Biosciences." Includes bibliographical references.

<p>Denna studie har genom halvstrukturerade kvalitativa intervjuer med 13 högstadieelever undersökt hur eleverna upplever två reklamfilmer mot mobbing. Filmerna har lanserats av stiftelsen Friends och utgör en del i deras arbete mot mobbing. Resultatet sammanställdes genom induktiv tematisk analys och åtta teman framkom. Temana var: Känsloprocess, Indirekt mobbing berör mer än direkt mobbing, Kan hända vem som helst, Förståelse för mobboffret, Hjälparen väcker beundran, Medlöparens brist på ingripande, Lärarens passivitet irriterar samt Alla kan hjälpa till. Det resultat som framkom jämfördes med det som Friends önskade att åskådaren skulle uppleva. Resultatet kopplades även ihop med teorierna bystander-effect och empati. Det visade sig att intervjupersonerna i stort upplevde filmerna som Friends önskade.</p>

Denna studie har genom halvstrukturerade kvalitativa intervjuer med 13 högstadieelever undersökt hur eleverna upplever två reklamfilmer mot mobbing. Filmerna har lanserats av stiftelsen Friends och utgör en del i deras arbete mot mobbing. Resultatet sammanställdes genom induktiv tematisk analys och åtta teman framkom. Temana var: Känsloprocess, Indirekt mobbing berör mer än direkt mobbing, Kan hända vem som helst, Förståelse för mobboffret, Hjälparen väcker beundran, Medlöparens brist på ingripande, Lärarens passivitet irriterar samt Alla kan hjälpa till. Det resultat som framkom jämfördes med det som Friends önskade att åskådaren skulle uppleva. Resultatet kopplades även ihop med teorierna bystander-effect och empati. Det visade sig att intervjupersonerna i stort upplevde filmerna som Friends önskade.

The communication of information between irradiated and non-irradiated bystander cell populations and the subsequent expression of radiation-like responses in the non-irradiated population, formally referred to as the radiation-induced bystander effect, is a very well established phenomenon in the study of radiobiology. Intercellular communication of bystander signals is known to occur via the exchange of soluble factors through biological fluids and via the transfer of molecules between adjacent cells via gap-junctions. Both of these communication methods require some degree of physical contact between biological entities. However, observations made in the literature demonstrating the induction of radiation effects in optically-coupled, yet chemically-separated organisms raises the hypothesis that alternative radiation bystander communication mechanisms may exist that have not yet been explored. Following the detection of significant photon emission from human keratinocyte cells exposed to ionizing beta-radiation by Ahmad in 2013, the involvement of an electromagnetic bystander signal was proposed. While not yet established in the field of radiobiology, intercellular communication via electromagnetic signalling is widely studied in the field of biophotonics. The emission of electromagnetic radiation from biological material, called biophoton emission, and the subsequent communication of effects using those signals has been characterized both spontaneously and as a result of perturbation by various stressors. This thesis therefore aimed to investigate intercellular communication via electromagnetic signalling stimulated by low-dose ionizing radiation to identify a possible convergence between the fields of biophoton communication and radiation-induced bystander effects. The characterization of biophoton emission from human cell cultures was accomplished using a single photon counting photomultiplier tube. The results revealed that biophoton emission is exacerbated by external stimulation (beta-radiation), it possesses a dependence upon the activity of radiation delivered, the density of the irradiated cell culture, and cell viability. These results suggest that biophoton emission is governed by physical transitions between excited and ground states and may further be modulated by metabolic processes. An effect of beta-radiation-induced biophoton emission upon non-irradiated bystander cells was identified and manifested as a reduction in cell survival. The modulatory effects observed following the application of photomodulating agents to the bystander cultures support ultraviolet electromagnetic radiation as a responsible factor in the communication of bystander signals. Observation of photon emission across the entire ultraviolet, visible and infrared spectra lead to the suggestion that ultraviolet wavelengths are only a portion of the signal responsible for eliciting bystander responses and that coherent interaction of multiple wavelengths is probable in the intercellular exchange of information. The possibility of a link between biophoton bystander signalling and soluble factor mediated bystander effects was investigated next by isolating exosomes from biophoton-exposed bystander cultures. Positive bystander responses were exhibited by secondary reporter cells incubated with the exosomes isolated from the biophoton-exposed bystander cultures, thereby suggesting that biophoton signalling is a possible form of biological redundancy where it acts as an intermediary to trigger soluble factor release and further reinforce intercellular communication. Finally, the effect of beta-radiation-induced biophoton signals upon mitochondrial activity was assessed and revealed the capacity for biophotons to downregulate Complex I and ATP synthase activity. The demonstrated effect of biophotons upon mitochondria elucidates a candidate mechanism worthy of further exploration to determine how biophotons may trigger responses in bystander cells. Overall, this thesis elucidates an additional mechanism for intercellular communication between biological systems perturbed by low doses of ionizing radiation, in the form of an electromagnetic signal. This work contributes to the current perspective on biophoton bystander signalling as a potential source of biological redundancy, facilitating a means of intercellular communication when optical coupling but not chemical contact is available in a given system. / Thesis / Doctor of Philosophy (PhD)

Τα αποτελέσματα ποικίλων δόσεων ακτινών Χ στην κυτταρική απόπτωση, τον πολλαπλασιασμό, την έκφραση του υποδοχέα του επιδερμικού αυξητικού παράγοντα (EGFR) και των μεταλλοπρωτεϊνασών-2 (MMP-2), μελετήθηκαν σε δύο κυτταρικές σειρές ανθρώπινου γλοιοβλαστώματος. Μέθοδος: Οι κυτταρικές σειρές LN18 και M059K ακτινοβολήθηκαν σε θερμοκρασία δωματίου με δόσεις κυμαινόμενες από 0,5 έως 15 Gy με τη χρήση πηγής 6 MV. Η απόπτωση μελετήθηκε με τη μέθοδο annexin V, ο πολλαπλασιασμός με τη μέθοδο MTT (methyl tetrazolium) και η έκκριση των MMP-2 με ζυμογράφημα. H καταγραφή των επιπέδων του φωσφοριωμένου EGFR έγινε με ELISA. Αποτελέσματα: Ο κυτταρικός πολλαπλασιασμός ανεστάλη με δόσο-εξαρτώμενο τρόπο ενώ η απόπτωση αυξήθηκε σημαντικά μετά την ακτινοβολία. Σε δόσεις μικρότερες των 2 Gy δεν καταγράφηκε καμία μεταβολή στην απόπτωση και τον κυτταρικό πολλαπλασιασμό. Τα επίπεδα των MMP-2 αυξήθηκαν 48 ώρες μετά την ακτινοβόληση με δόσο-εξαρτώμενο τρόπο. Αντιθέτως, η έκφραση του EGFR αυξήθηκε σημαντικά 15 λεπτά μετά την ακτινοβόληση και κατά δόσο-εξαρτώμενο τρόπο. Συμπέρασμα: Η ιοντίζουσα ακτινοβολία επάγει την έκφραση του EGFR και αυξάνει την έκκριση των MMP-2 γεγονός που αιτιολογεί την διηθητική και κακοήθη συμπεριφορά των γλοιωμάτων καθώς και την ανταπόκριση τους στην ιοντίζουσα ακτινοβολία. / The effect of different doses of X(-)rays on apoptosis, proliferation, epidermal growth factor receptor (EGFR) and matrix metalloproteinase (MMP-2) expression was investigated in a human glioblastoma cell line. Materials and Methods: The cell line LN18 was irradiated at room temperature with doses ranging from 0.5 to 15 Gy using 6 MV X(-)rays. Apoptosis was assessed using the annexin V binding assay, proliferation by the methyl tetrazolium (MTT) assay and MMP-2 secretion with zymography. The levels of phosphorylated (pEGFR) were estimated using a commercially available ELISA kit. Results: Cell proliferation decreased in a dose-dependent manner, while apoptosis was increased after radiation. Doses below 2 Gy did not affect proliferation or apoptosis. MMP-2 levels were increased 48 h after radiation in a dose-dependent manner. In contrast, EGFR signaling was significantly activated 15 min after radiation in a dose-dependent manner. Conclusion: Ionizing radiation activates EGFR signalling and enhances MMP-2 secretion, suggesting that the molecular pathways involved may contribute to the invasiveness and malignant behaviour of glioma cells and help to explain the response of gliomas to ionizing radiation.

Detta examensarbete ämnar undersöka den roll och påverkan elever som är åskådare till mobbning i skolmiljö har, utifrån teorin The Bystander Effect. Utgångspunkten är mellanstadielärares berättelser om, erfarenheter och upplevelser av mobbning mellan elever med ett särskilt fokus på de som är åskådare. Med en kvalitativ ansats har semi-strukturerade intervjuer med sex lärare som undervisar i årskurs 4–6 genomförts.Studiens resultat tyder på att åskådare spelar en viktig roll vid mobbning mellan elever, både genom att förstärka och upprätthålla mobbningen, men också genom att avbryta denna när de väljer att ingripa och hjälpa offret. En rad olika faktorer sågs påverka den roll åskådare antog, som passiva eller ingripande, varav de viktigaste ansågs vara gruppen och omgivningens klimat och normer samt de olika konsekvenser som beskrevs åtfölja såväl mobbning som ingripande. Centralt var också de olika typer av kontroll lärare försökte utöva för att påverka mobbningen, genom att definiera den, lära och utbilda elever om mobbning samt att själva inneha det huvudsakliga ansvaret för att ingripa och stoppa mobbningen. Genomgående i informanternas berättelse återfanns de mekanismer som stärker eller hämmar The Bystander Effect och åskådares passivitet kontra aktiva ingripande. / The purpose of this essay is to analyze the effect that bullying has on the observing party with reference to The Bystander Effect. We have chosen to use semi—structured interviews with six different elementary school teachers, grade 4 to 6, as basis for our analysis. In the interviews the teachers referred to experiences where they had personally witnessed bullying amongst students; focusing on details regarding the bystanders.The data collected from the interviews leads us to believe that bystanders play a role in both enforcing and interrupting bullying. Many factors were observed that affected the bystanders' reaction whether passive or intrusive. These included the social norms, social climate and perceived consequence of both bullying and various forms of interference. Another key factor was the teachers' methods to minimize bullying and their ability to do so. The different interviews highlighted certain mechanisms that strengthened or weakened The Bystander Effect.

David Cash was a college student who found himself in the women's restroom of the Primadonna in Nevada. He witnessed his friend, Jeremy Strohmeyer raping and killing a 7-year-old girl. Cash did not take any action in trying to prevent this heinous crime. There are many elements to consider when bystanders neglect to take action. Research examining bystander apathy in critical situations is lacking, yet the number of violent crimes witnessed by others where intervention is not offered continues to escalate. Bullying often occurs in the presence of others. Bystander apathy is believed to play a passive role in most cases of bullying. This study investigated the psychological symptom patterns of intervening and non-intervening bystanders in bullying events. It was hypothesized that there would be a significant difference in the SLC-90-R profiles between intervening and non-intervening bystanders. It was further hypothesized that gender would significantly interact with the bystander response to witnessing bullying. Data were collected from undergraduate participants at the University of Central Florida through The Psychology Department's Psychological Research Participant System (aka, SONA). Psychological Symptoms were evaluated using the Symptom-Checklist-90-Revised (SCL-90-R). Data was obtained from 135 undergraduate participants. The sample consisted of 42 males and 93 females between 18 to 58 years of age. The participants were categorized by intervening and non-intervening bystanders. A two-way between subjects MANOVA was used to assess the influence of gender and intervening and non-intervening bystanders on the nine SLC-90-R symptom domains. No significant main effects or interaction was observed. However, a review of the univariate analyses revealed a significant gender x intervening interaction on the paranoid ideation subscale, F(1, 131) = 4.823, p = .03. Implications and directions for future research are discussed.

The radiation-induced bystander effect is an important phenomenon in the field of radiation biology. It has been shown that cells, after exposure to radiation, can communicate with surrounding cells and affect their physiology. Otherwise-healthy recipient cells can be influenced to undergo cellular senescence or apoptosis through this process. This has potential utilizations for radiation oncology and as well as our understanding of radiation safety. The radiation-induced bystander effect has been extensively investigated since the 1990s, but the scientific community struggles to come to a unanimous decision on how strongly these signals impact the survival of bystander cells. Results show various degrees of impact on cell survival whereas certain studies refute the existence of a radiation-induced bystander effect. This may be due to the fact that there is a great deal of study heterogeneity within the radiation-induced bystander effect community. Most experiments follow a similar general bystander protocol but often use different donor and reporter cell lines that vary in sex, organ of origin, and p53 status. The type of radiation and dose rate also typically differ between experimental designs. In this analysis, 67 in vitro, medium-transfer, radiation-induced, bystander effect studies were retrospectively graphed and analyzed to determine which intrinsic and external factors contributed significantly to the overall survival percentage change observed in reporter cells. A Two-Way ANOVA was conducted on each variable and showed that the reporter cell line, p53 status, and radiation type had a statistically significant effect on survival percentage change. These findings may explain the variation in results seen in past experiments and may help standardize future research allowing for more direct comparisons. / Thesis / Master of Science (MSc)

In recent years, the use of bystander intervention training to address campus sexual violence has risen rapidly. More research is critically needed to guide the ongoing development and implementation of prevention efforts by campuses utilizing this relatively new approach. This investigation examined associations between college students' bystander intervention behavior and three key factors: (1) perceived peer norms supportive of sexual violence; (2) perceived campus administrative response to sexual violence; and (3) sense of campus community. Data from a sample of 2370 college students was analyzed using hierarchical linear regression to test both direct and moderated effects. Findings revealed that both peer norms supportive of sexual violence and perceptions of campus administrative response to sexual violence were significantly associated with bystander intervention. No significant direct or moderating effects related to sense of campus community were uncovered in this sample. Implications of this study include contributing to the current knowledge base about factors associated with bystander intervention behavior, and informing campus efforts to make bystander training programs more effective.

No description available.