Saturated laser fluorescence in turbulent sooting flames at high pressure

The primary objective was to develop a quantitative, single pulse, laser-saturated fluorescence (LSF) technique for measurement of radical species concentrations in practical flames. The species of immediate interest was the hydroxyl radical. Measurements were made in both turbulent premixed diffusion flames at pressures between 1 and 20 atm. Interferences from Mie scattering were assessed by doping with particles or by controlling soot loading through variation of equivalence ratio and fuel type. The efficacy of the LSF method at high pressure was addressed by comparing fluorescence and adsorption measurements in a premixed, laminar flat flame at 1-20 atm. Signal-averaging over many laser shots is sufficient to determine the local concentration of radical species in laminar flames. However, for turbulent flames, single pulse measurements are more appropriate since a statistically significant number of laser pulses is needed to determine the probability function (PDF). PDFs can be analyzed to give true average properties and true local kinetics in turbulent, chemically reactive flows

Elucidating the Influence of the Activation Energy on Reaction Rates by Simulations Based on a Simple Particle Model

An application for visualizing the dynamic properties of an equimolar binary mixture of isotropic reactive particles is presented. By introducing a user selectable choice for the activation energy, the application is useful to demonstrate qualitatively that the reaction rate depends on the above choice and on temperature. The application is based on a 2D realistic dynamic model where atoms move because of their thermal energies and the trajectories are determined by solving numerically Newton’s laws according to a Molecular Dynamics (MD) scheme. Collisions are monitored as time progresses, and every time the collision energy is larger than the selected activation energy, a reactive event occurs. By examining the time evolution of the configurations, it is possible to observe that the number of reactive collisions is always smaller than the total number of collisions. However, the number of reactive events increases on raising the temperature and/or by decreasing the activation energy. The above observations, as well as more quantitative analyses of the simulation data, are useful in elucidating the connections existing among particle kinetic energy, temperature, and activation energy of the reaction. The application can be used at different levels of detail and in different instruction levels. Qualitative visual observations of the progress of the reaction are suitable at all levels of instruction. Systematic investigations on the effect of changes of temperature and activation energy, suitable for senior high school and college courses and useful to gain insight into kinetic models and Arrhenius’ law, are also reported

Microfluorometric technique for the determination of localized heating in organic particles

We describe a novel microfluorometric technique, based on the temperature-dependent fluorescence emission from single dye-labeled phospholipid vesicles, for the determination of localized heating effects. An increase in sample temperature results in a red shifting of the probe fluorescence spectrum. As individually calibrated microthermometers, fluorescent liposomes exhibit a temperature sensitivity of ∼0.1°C in the vicinity of the bilayer phase transition temperature. Through modification of the bilayer components, both the sensitivity and operating temperature range of these microthermometers can be controlled. Micron spatial resolution is achieved at a signal-to-noise ratio in excess of 103:1. We use the above technique, for the first time, to determine localized heating effects induced by a laser beam focused to its near-diffraction limited spot size. At the laser wavelength of λ=1.064 μm, a temperature change of 1.1°C/100mW in 10-μm-diam organic liposomes is reported. Implications for the real-time optical monitoring of temperature in biological systems are discussed

Adenovirus DNA in Guthrie cards from children who develop acute lymphoblastic leukaemia (ALL)

Aims: The aim of this thesis was to increase understanding of how molecular processes influence the development and risk assessment of childhood leukemia. Studies I and II investigates whether a specific virus infection in utero could be involved in a “first hit” in leukemogenesis. Studies III and IV examine whether alterations in protein expression from cell cycle regulating genes may predict a relapse in children with myeloid malignancies undergoing hematopoietic stem cell transplantation (HSCT). Background: Genetic alterations, analyzed at time of diagnosis in children who develop leukemia, have been traced back to neonatal dried blood spots (DBS). This suggests that the majority of chromosome translocations occur in utero during fetal hematopoiesis, generating a “first hit”. A “second hit” is then required to generate a leukemic clone. Today, experiments in vitro, animal models, and clinical observations have revealed that several viruses are oncogenic and capable of initiating a genetic alteration. Smith M postulated the theory that an in utero infection might be the “first hit”, causing genetic aberrations that could later lead to the development of the leukemic clone, which is supported by the early age of onset and space-time clustering data, based on time, place of birth, and diagnosis. Leukemia develops as a result of hematopoietic or lymphoid tissue with uncontrolled cell division. Normally cell division is controlled by the cell cycle, the network of which is complex with numerous regulating proteins both up and down stream, but also containing several feedback loops. The important regulators of this process are tumor suppressor genes, essential for normal cell proliferation and differentiation as well as for controlling DNA integrity. Errors in these genes or their protein expression affect the ability of the cell to check for DNA damage, thus tumors may occur. Proteins from these genes could serve as prognostic markers and predict relapse. Methods: In studies I and II we investigated neonatal DBS by PCR for the presence of adenovirus DNA (243 samples) and the three newly discovered polyomaviruses (50 samples) from children who later developed leukemia but also from controls (486 and 100 samples respectively). In studies III and IV we explored the expression of one (p53) respectively four (p53, p21, p16 and PTEN) cell cycle regulating proteins in bone marrow at diagnosis as well as pre and post HSCT in myeloid malignancies in children. We retrospectively collected clinical data and bone marrow samples from 33 children diagnosed with chronic myeloid malignancies (MDS, JMML and CML), 34 children diagnosed with AML as well as 55 controls. The samples were prepared by tissue micro array (TMA) as well as immunohistochemistry and examined for protein expression in a light microscope. Results: In study I we detected adenovirus DNA in only two patients who later developed leukemia, but in none of the controls. In study II all the samples were negative for KIPyV, WUPyV and MCPyV DNA in both patients and controls. In study III we found an overexpression of p53 protein at diagnosis that significantly predicted relapse after HSCT in children with rare chronic myeloid malignancies. In study IV a significantly higher p53 expression was found in the relapse compared to the non-relapse group at six months post HSCT in children with AML, suggesting that p53 may be used as prognostic markers for predicting a relapse. In addition, the calculated cut off level for p53 at diagnosis (study III) and at six months (study IV) post HSCT was approximately 20%, which indicates that a p53 expression over 20% may predict relapse in children with myeloid malignancies. Conclusion: Although we did not find an association between adenoviruses or the three newly discovered polyomaviruses and the development of childhood leukemia, a virus could still be involved in this process; the virus may have escaped detection, other new viruses could be involved or a virus could precipitate the “second hit”. We suggest that evaluation of p53 protein expression may be used as a supplement to regular prognostic markers both pre and post HSCT. To further evaluate this, a prospective multicenter study has been started

‘It used to be brutal, now it’s an art’:changing negotiations of violence and masculinity in British karate

In most western (and indeed eastern) cultures, fighting is seen as an ultimate symbol of masculinity – an embodied display of dominance, control and violence (Bourdieu, 2001). As a space legitimising and praising performances of mimetic violence (Dunning, 1999), combat sports provide an arena where the virtues of dominance and power at the heart of conceptions of orthodox masculinity (Anderson, 2010 ) or hegemonic masculinity (Connell, 2005) can be symbolically presented by men through bodily displays of strength, physical aggression, and the taking and overcoming of pain (Bourdieu, 2001; Messner, 1990; Wacquant, 2004). Yet, over the last twenty years the focus of karate in Britain has been perceived to shift from aggressive acts of 'hitting hard' to developing and displaying controlled, acrobatic and technically precise movements. Drawn from a nine-month ethnography and 7 semi-structured interviews, this chapter explores how British male karate practitioners re/negotiate ideas of masculinity and embodiments of a masculine identity in the context of karate’s changing emphasis on, and practices of, 'violence'. This paper suggests that a 'civilising' shift (Elias and Dunning, 1986) in the competition rules increases in women’s participation in karate with men, and subsequent negotiations of mimetic violence, complicate the use of violence as a symbol of praised masculine identity within British karate . A praised masculine identity is crafted by carefully blending traits conventional deemed feminine such as technical precision, elegance and agility alongside displays of strength and dominance. Such performances challenge conceptions of an orthodox sporting masculinity and notions of hierarchical gender distinction

Knowledge translation research in population health: establishing a collaborative research agenda

<p>Abstract</p> <p>Background</p> <p>Despite the increasing mobilization of researchers and funding organizations around knowledge translation (KT) in Canada and elsewhere, many questions have been only partially answered, particularly in the field of population health. This article presents the results of a systematic process to draw out possible avenues of collaboration for researchers, practitioners and decision-makers who work in the area of KT. The main objective was to establish a research agenda on knowledge translation in population health.</p> <p>Methods</p> <p>Using the Concept Mapping approach, the research team wanted to identify priority themes for the development of research on KT in population health. Mapping is based on multivariate statistical analyses (multidimensional scaling and hierarchical cluster analysis) in which statements produced during a brainstorming session are grouped in weighted clusters. The final maps are a visual representation of the priority themes of research on KT. Especially designed for facilitating consensus in the understanding and organization of various concepts, the Concept Mapping method proved suitable for achieving this objective.</p> <p>Results</p> <p>The maps were produced by 19 participants from university settings, and from institutions within the health and social services network. Three main perspectives emerge from this operation: (1) The evaluation of the effectiveness of KT efforts is one of the main research priorities; (2) The importance of taking into consideration user contexts in any KT effort; (3) The challenges related to sharing power for decision-making and action-taking among various stakeholder groups. These perspectives open up avenues of collaboration for stakeholders who are involved in research on KT. Besides these three main perspectives, the concept maps reveal three other trends which should be emphasized.</p> <p>Conclusion</p> <p>The Concept Mapping process reported in this article aimed to provoke collective reflection on the research questions that should be studied, in order to foster coherence in research activities in the field of population health. Based on this, it is appropriate to continue to support the development of research projects in KT and the formation of research teams in this field. Research on KT must lead to concrete outcomes within communities that are interested in the question.</p

Apoptotic HPV Positive Cancer Cells Exhibit Transforming Properties

Previous studies have shown that DNA can be transferred from dying engineered cells to neighboring cells through the phagocytosis of apoptotic bodies, which leads to cellular transformation. Here, we provide evidence of an uptake of apoptotic-derived cervical cancer cells by human mesenchymal cells. Interestingly, HeLa (HPV 18+) or Ca Ski (HPV16+) cells, harboring integrated high-risk HPV DNA but not C-33 A cells (HPV-), were able to transform the recipient cells. Human primary fibroblasts engulfed the apoptotic bodies effectively within 30 minutes after co-cultivation. This mechanism is active and involves the actin cytoskeleton. In situ hybridization of transformed fibroblasts revealed the presence of HPV DNA in the nucleus of a subset of phagocytosing cells. These cells expressed the HPV16/18 E6 gene, which contributes to the disruption of the p53/p21 pathway, and the cells exhibited a tumorigenic phenotype, including an increased proliferation rate, polyploidy and anchorage independence growth. Such horizontal transfer of viral oncogenes to surrounding cells that lack receptors for HPV could facilitate the persistence of the virus, the main risk factor for cervical cancer development. This process might contribute to HPV-associated disease progression in vivo

Gasification in pulverized coal flames. First quarterly progress report, July--September 1975

This project is concerned with the production of power and synthesis gases from pulverized coal via suspension gasification. Specifically, the concentric jet and vortex gasifiers, with separation of oxidation and reduction zones, will be investigated. Gasifier performance will be correlated with internally measured temperature and concentration profiles. A suction pyrometer will be used to simultaneously measure temperature and gas concentrations. Rapid species analysis will be provided by a UTI Q-30C mass spectrometer system. To date, a coal-handling facility has been developed, test cell design has been initiated, and preliminary literature searches have been made. A coal crusher, pulverizer, feeder, and sieve shaker are on order. Preliminary consultations are underway concerning the mass spectrometer system. (auth