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.

Bakgrund: Varje år så sker det ungefär 6000 hjärtstopp utanför sjukhus i Sverige. När ett hjärtstopp sker så är tiden till behandling avgörande för den drabbades chans att överleva. Den eller de första på plats, så kallade bystanders ingripande innan annan räddningspersonal har anlänt till platsen är ofta livsavgörande. Därför är bystanders inställning inför att ingripa med HLR utanför sjukhus ett otroligt viktigt forskningsämne. Syfte: Syftet var att belysa bystanders inställning inför att ingripa med hjärt-lungräddning (HLR) vid hjärtstopp utanför sjukhus. Metod: En allmän litteraturstudie genomfördes via granskning och analys av 9 vetenskapliga artiklar, både kvantitativa och kvalitativa som utgjordes av sökningar i databaserna Cinahl och PubMed. Resultat: I resultatet framkom tre olika kategorier som presenteras i arbetet. Rädslor inför att utföra HLR, betydelsen av HLR-utbildning samt kontextuella variationer i inställning Slutsats: Det finns rädslor och farhågor hos bystanders inför att ingripa med HLR i samhället. Det är viktigt att ha förståelse för detta och använda kunskapen för att förbättra HLR-utbildningen samt att man utbildar mer och på så sätt bidrar till ökad bystander-HLR och därmed ökad överlevnad vid hjärtstopp utanför sjukhus. Nyckelord: bystander, hjärt-lungräddning, hjärtstopp, inställning, utanför sjukhus

The purpose of this study was to decrease school bullying by implementing a class-wide intervention that targets bystanders. Hypotheses include that an intervention will increase prosocial bystander behaviors that will result in reduced rates of bullying and improved positive peer responses. Ross and Horner’s Positive Behavior Supports bullying prevention program was modified to increase incentives for students who defend others from bullying. A multiple baseline design across three general education classrooms was used to examine the effectiveness of the intervention in an elementary school in northwestern Utah. Pre- and posttests were administered to assess participant roles and student intervention acceptability. The findings of the study suggested that bullying behavior decreased and defending increased. Further, acceptability of the intervention and the skills taught to children were rated as moderately high across all classrooms. Even though bullying incidences decreased substantially, bullying behaviors were not eradicated completely in the three classrooms. To decrease rates of bullying further, secondary and tertiary interventions along with continued functional assessment on why bullying occurs are needed. Further, to help increase the practicality of teaching peers the critical skills of defending victims, research on how to increase students’ ability and motivation to intervene is essential.

No description available.

No description available.

No description available.

No description available.

No description available.

<p>Radiation induced bystander effects have given the cancer risk analysis a whole new paradigm. However the actual mechanism involved in producing the effects is still not clear. The basic bystander signal is assumed to be a biological signal. In this study we proposed and tried to quantify the presence of a physical signal in the form of electromagnetic radiation that can trigger a biological response in the bystander cells. In bystander effect studies where the cells are exposed to very low fluence of charged particles there could be several regions that can produce electromagnetic radiation due to the process of atomic/molecular excitations and relaxations. We focused on quantifying the number of ultraviolet photons emitted when charged particles pass through different media that have relevance to radiation biology experiments. The choice of UV photons was made due to the reason that its effects on living cells are very well documented. For this purpose we developed a system which employed the technique of single photon counting to measure the light emitted from samples irradiated under vacuum by a charged particle beam. Photon counting was done using a fast photomultiplier tube (Hamamatsu R7400p) with a peak cathode response at 420 nm wavelength.</p> <p>In the early set of “proof of principle experiments” we tested polystyrene targets for ion beam induced luminescence. Polystyrene is one of the materials that are used as a cell substrate for radiation biology experiments. The luminescence yield from polystyrene was measured in terms of absolute value i.e. number of photons per second per unit solid angle. The output appeared to have a non-linear behavior with the incident Ion fluence: it rose exponentially to an asymptotic value. We irradiated the samples with beam energies varying from 1 MeV to 2.0 MeV and showed saturation at or before an incident fluence rate of 3×10¹³ H⁺/cm²s. The average saturation value for the photon output was found to be 40 × 10⁶ cps. Some measurements were performed using filters to study the emission at specific wavelengths. In the case of filtered light measurements, the photon output was found to saturate at 28×10³, 10×10⁶, and 35×10⁶ cps for wavelengths of 280±5 nm, 320±5 nm and 340±5 nm respectively. Using the IBIL signal evolution characteristics with the ion fluence we determined the ions produce a damage having a cross section of the order of 10^-14 cm² in polystyrene. The average radiant intensity was found to increase at wavelengths of 280 nm and 320 nm when the proton energy was increased. Having found an evidence of a significant production of UV in ion irradiated, biologically relevant, material we extended this study further into the measurements from other relevant materials in radiation biology.</p> <p>Here charged particle irradiation was performed using positively charged protons (H⁺) ranging in energy from 1.2 MeV to 2.2 MeV at a fluence rate of 2.7×10¹⁰ protons mm^-2s^-1.The materials chosen for this study were polypropylene, Mylar, Teflon, and Cellophane as they are all materials commonly used in radiation biology experiments as cell substrates or containers. In addition, we performed measurements of two NIST standard materials derived from living cells: oyster tissue and citrus leaves. These materials were measured as a powder.</p> <p>All the container materials were found to emit UV frequency photons at emission levels that are significant enough to warrant further investigation of the potential biological consequences. In addition, the NIST standard reference materials oyster tissue and citrus leaves also emitted UV when irradiated. This suggested that biological materials may themselves emit UV at significant levels when irradiated with charged particles.</p> <p>We established this further by irradiated cells with β-particles. Cells were plated in Petri-dishes of two different sizes, having different thicknesses of polystyrene (PS) substrate. Exposure of the cell substrates (polystyrene) only resulted in the production of 1035 photons per unit activity in μCi of ⁹⁰Y which was equivalent to an exposure of 840 <em>β</em>-particles/cm² to the substrate. For a collimated electron beam exposure, we observed 158-167 photons per unit μCi (18 β-particles per cm² on the substrate) for different thicknessesof the substrate. Upon irradiating HPV-G cells plated on the PS dishes we determined that the luminescence gradually increased with the increasing exposure of β-particles; reaching up to 250 % of that of the luminescence without any cells for an activity of 180 μCi. For general irradiation conditions we found statistically significant difference in luminescence output for varying cellular densities with cells only and with the application of medium on top of the cells. The colourless medium increased the total luminescence yield while the coloured medium decreased it. When the cells were irradiated using a collimated beam of electrons it was found that the luminescence decreases with the increasing cellular density thus providing an evidence of re-absorption of photons within the surroundings.</p> <p>After establishing the fact that charged particles induce light emission from the materials that have a relevance to the radiation biology experiments. We extended our study further to find out other sources of radiation that could affect the dose distribution in radiation biology experiments. In radiation biology experiments the low doses of radiation are usually delivered usingamicrobeam charged particle accelerator. Microbeams delivers a highly localized and small dose to the biological medium by using a set of collimators that confine the charged particle beam to a very narrow (micron level) region. Since the collimation block a significant proportion of the beam therefore there is a chance of the production of low energy x-rays and secondary electrons. We used Monte Carlo simulations to investigate the production of particle induced x-rays and secondary electrons in the collimation system and its possible effects on the final dose delivery to the biological medium. We found no evidence of the escape of x-rays or secondary electrons from the collimation system for proton energies of up to 3 MeV. The thickness of the collimators was sufficient to reabsorb all the generated low energy x-rays and secondary electrons. However if the proton energy exceeds 3 MeV then a significant proportion of 10 keV and 59 keV (K-α) x-rays can be emitted by the collimator. Further it was established that due to the phase space distribution of particles in various orientations with the beam axis there are significant chances of hitting non-targetted cells in microbeams that employ a collimator to confine the beam.This may happen due to the beam particles travelling obliquely with the beam axis thus passing the collimator edge and hitting the non-targetted cells. Another reason could be the scatter of beam particles inside the collimator.</p> <p>The evidence of the production of UV in materials relevant to the radiation biology experiments suggest that the conclusions and hypotheses derived from some radiation bystander experiments need to be re-thought, as charged particle irradiation leads to some level of UV emission in experimental materials which may be the cause of some “non-targeted” effects.</p> / Doctor of Philosophy (PhD)

Asthma is defined as reversible airflow obstruction and an estimated 1-in-3 Canadians will be diagnosed over their lifetime. Many clinical phenotypes of asthma exist, but allergic asthma is the most common presentation. Despite effective therapies, approximately 65% of Canadian asthmatics have poorly controlled disease. Thus, there remains pressing need to develop disease modifying therapies. Allergen-specific immunotherapy (SIT) is a disease-modifying therapy for allergic disease that consists of repeatedly administering doses of allergen, to an allergic individual; over 100 years of clinical use, SIT has been demonstrated to reduce symptoms of disease both during and after cessation of therapy. Widespread clinical uptake of SIT has been limited by the risk of developing anaphylaxis as a response to therapy. Peptide immunotherapy is a derivation of SIT, that attempts to retain the disease-modifying benefits, while lessening the risk of anaphylaxis, by treating subjects with allergen-derived T-cell peptide epitopes. Peptide immunotherapy has been demonstrated to reduce symptoms of allergic disease in treated subjects; however, it remains unknown how administration of a single (or several) T-cell epitopes can modulate immune responses to entire complex allergens. Additionally, how genetic diversity in peptide epitope presentation effects the development of immune tolerance is unknown. In this thesis, we sought to characterize these mechanisms of peptide immunotherapy; the hypothesis was, “The induction of immunosuppression by peptide immunotherapy involves the infectious spread of tolerance beyond the treatment epitope, and is dependent upon treatment peptide dose and affinity to MHC”. Through the definition of these mechanistic traits we hoped to expedite and inform the design of future peptide based therapeutics. The studies presented within this thesis examine the topic of immune modulation of allergic disease in mouse models, and have focused upon broadly pertinent characteristics of immune modulation, such as the number, dose and affinity of immunomodulatory epitopes. / Thesis / Doctor of Philosophy (PhD) / Asthma is a disease of the airways that can cause difficulties in breathing. In some people, asthma develops because their immune system reacts in an uncontrolled manner to common environmental proteins, called allergens. Whole allergen immunotherapy is a treatment for asthma, where asthmatic people are injected with doses of allergen until their immune system no longer responds to (or ‘tolerates’) the allergen. In some people, injection of allergen can lead to a life-threatening immune response known as ‘anaphylaxis’. Peptide-immunotherapy is a form of whole allergen immunotherapy where people are given small fragments of the allergen (a ‘peptide’) rather than the whole allergen. The benefit of peptide immunotherapy is that the treatment peptides are too small to cause anaphylaxis, but remain large enough to teach the immune system. In this thesis, we examined how treatment with small peptides teaches the immune system to tolerate the larger and more complex whole allergen.