Hypervelocity impact survivability experiments for carbonaceous impactors

We performed a series of hypervelocity impact experiments using carbon-bearing impactors (diamond, graphite, fullerenes, phthalic acid crystals, and Murchison meteorite) into Al plate at velocities between 4.2 and 6.1 km/s. These tests were made to do the following: (1) determine the survivability of carbon forms and organize molecules in low hypervelocity impact; (2) characterize carbonaceous impactor residues; and (3) determine whether or not fullerenes could form from carbonaceous impactors, under our experimental conditions, or survive as impactors. An analytical protocol of field emission SEM imagery, SEM-EDX, laser Raman spectroscopy, single and 2-stage laser mass spectrometry, and laser induced fluorescence (LIF) found the following: (1) diamonds did not survive impact at 4.8 km/s, but were transformed into various forms of disordered graphite; (2) intact, well-ordered graphite impactors did survive impact at 5.9 km/sec, but were only found in the crater bottom centers; the degree of impact-induced disorder in the graphite increases outward (walls, rims, ejecta); (3) phthalic acid crystals were destroyed on impact (at 4.2 km/s, although a large proportion of phthalic acid molecules did survive impact); (4) fullerenes did not form as products of carbonaceous impactors (5.9 - 6.1 km/s, fullerene impactor molecules mostly survived impact at 5.9 km/s; and (5) two Murchison meteorite samples (launched at 4.8 and 5.9 km/s) show preservation of some higher mass polycyclic aromatic hydrocarbons (PAHs) compared with the non-impacted sample. Each impactor type shows unique impactor residue morphologies produced at a given impact velocity. An expanded methodology is presented to announce relatively new analytical techniques together with innovative modifications to other methods that can be used to characterize small impact residues in LDEF craters, in addition to other acquired extraterrestrial samples

Confocal Imaging of Transmembrane Voltage by SEER of di-8-ANEPPS

Imaging, optical mapping, and optical multisite recording of transmembrane potential (Vm) are essential for studying excitable cells and systems. The naphthylstyryl voltage-sensitive dyes, including di-8-ANEPPS, shift both their fluorescence excitation and emission spectra upon changes in Vm. Accordingly, they have been used for monitoring Vm in nonratioing and both emission and excitation ratioing modes. Their changes in fluorescence are usually much less than 10% per 100 mV. Conventional ratioing increases sensitivity to between 3 and 15% per 100 mV. Low sensitivity limits the value of these dyes, especially when imaged with low light systems like confocal scanners. Here we demonstrate the improvement afforded by shifted excitation and emission ratioing (SEER) as applied to imaging membrane potential in flexor digitorum brevis muscle fibers of adult mice. SEER—the ratioing of two images of fluorescence, obtained with different excitation wavelengths in different emission bands—was implemented in two commercial confocal systems. A conventional pinhole scanner, affording optimal setting of emission bands but less than ideal excitation wavelengths, achieved a sensitivity of up to 27% per 100 mV, nearly doubling the value found by conventional ratioing of the same data. A better pair of excitation lights should increase the sensitivity further, to 35% per 100 mV. The maximum acquisition rate with this system was 1 kHz. A fast “slit scanner” increased the effective rate to 8 kHz, but sensitivity was lower. In its high-sensitivity implementation, the technique demonstrated progressive deterioration of action potentials upon fatiguing tetani induced by stimulation patterns at \u3e40 Hz, thereby identifying action potential decay as a contributor to fatigue onset. Using the fast implementation, we could image for the first time an action potential simultaneously at multiple locations along the t-tubule system. These images resolved the radially varying lag associated with propagation at a finite velocity

Coping strategies and adaptation mechanisms utilized by female Holocaust survivors from the Auschwitz Concentration Camp

The female experience during the Holocaust has largely been ignored as significantly different than that of male counterparts. This gender-specific research study investigates the unique, poignant voices of women\u27s coping strategies utilized during internment in the Auschwitz Concentration Camp. Focusing specifically on the video oral history testimonies of the complete collection of female survivors of Auschwitz, which were produced by the United States Holocaust Memorial Museum, the study suggests that the predominate coping strategies used by females was affiliation with others as the means of survival. Through the utilization of clustering sheets, the data suggested that affiliation and assistance from others was essential in female survival and coping, coupled primarily with the utilization of emotion-focused coping strategies. Additionally, the study utilizes telephone interviews with the Holocaust survivors in the sample, three to five years after their testimonies were elicited as part of the permanent exhibits and research archives at the United States Holocaust Memorial Museum. The findings from the interviews concur with the predominant utilization of affiliation as a coping mechanism for survival of massive traumatization during internment in the Auschwitz Concentration Camp

The scientific and social construction of post-world war II US public health guidelines for physical activity: 1948-1996

Public health guidelines for (leisure time) physical activity evolved in the United States from scientific research which began in Britain and spread to North America during the second half of the 20th Century. This dissertation examines the guidelines' scientific and social construction. Research questions centre upon what has become known as the 'threshold-intensity vs volume-energy expenditure debate': Is a minimum intensity of physical activity necessary to achieve significant beneficial health outcomes? Or can that effective 'dose' be achieved by accumulating a sufficient total volume of expenditure (kcals) -- regardless of its intensity? The research questions are: 1. Why were public health guidelines switched from a focus upon vigorous intensity to moderate intensity, and was the science base sufficiently sound and uncontested to justify that switch on scientific (and social scientific) grounds? 2. Why were the guidelines so focused on cardiovascular disease (CVD) to the relative exclusion of other health outcomes? 3. Did a small, influential group of investigators play a disproportionate (anomalous) role in shaping the 1996 US Surgeon General's Report on Physical Activity and Health? Conclusions: The US Surgeon General's Report switched public health focus from vigorous to moderate intensity activities on a proclaimed 'emerging consensus' of scientific evidence. However, the science base remained complex and contested. This 'consensus' was, in large measure, socially constructed by a small group of investigators who had gained influence within the American Heart Association, the Centers for Disease Control and Prevention, the National Heart, Lung and Blood Institute, and then the very taskforce selected to write the Report. This dissertation explores a new and relevant area of 'Regulatory Science' given current interest in sedentary lifestyles and illness, not least cardiovascular disease and obesity. Anomalies in scientific interpretation and policy making arose not from financial considerations, but primarily from motives of altruism and professional status

Physical activity levels, ownership of goods promoting sedentary behaviour and risk of myocardial infarction: results of the INTERHEART study

Aims: To evaluate the association between occupational and leisure-time physical activity (PA), ownership of goods promoting sedentary behaviour, and the risk of myocardial infarction (MI) in different socio-economic populations of the world. Studies in developed countries have found low PA as a risk factor for cardiovascular disease, however, the protective effect of occupational PA is less certain. Moreover, ownership of goods promoting sedentary behaviour may be associated with an increased risk. Methods: In INTERHEART, a casecontrol study of 10 043 cases of first MI and 14 217 controls who did not report previous angina or physical disability completed a questionnaire on work and leisure-time PA. Results: Subjects whose occupation involved either light [multivariable-adjusted odds ratio (OR) 0.78, confidence interval (CI) 0.710.86] or moderate (OR 0.89, CI 0.800.99) PA were at a lower risk of MI, whereas those who did heavy physical labour were not (OR 1.02, CI 0.881.19), compared with sedentary subjects. Mild exercise (OR 0.87, CI 0.810.93) as well as moderate or strenuous exercise (OR 0.76, CI 0.690.82) was protective. The effect of PA was observed across countries with low, middle, and high income. Subjects who owned both a car and a television (TV) (multivariable-adjusted OR 1.27, CI 1.051.54) were at higher risk of MI compared with those who owned neither. Conclusion: Leisure-time PA and mild-to-moderate occupational PA, but not heavy physical labour, were associated with a reduced risk, while ownership of a car and TV was associated with an increased risk of MI across all economic regions

Interventions for preventing oral mucositis for patients with cancer receiving treatment

Interventions for preventing oral mucositis for patients with cancer receiving treatmentTreatment for cancer (including bone marrow transplant) can cause oral mucositis (severe ulcers in the mouth). This painful condition can cause difficulties in eating, drinking and swallowing, and may also be associated with infections which may require the patient to stay longer in hospital. Different strategies are used to try and prevent this condition, and the review of trials found that some of these are effective. Two interventions, cryotherapy (ice chips) and keratinocyte growth factor (palifermin®) showed some benefit in preventing mucositis. Sucralfate is effective in reducing the severity of mucositis, and a further seven interventions, aloe vera, amifostine, intravenous glutamine, granulocyte‐colony stimulating factor (G‐CSF), honey, laser and antibiotic lozenges containing polymixin/tobramycin/amphotericin (PTA) showed weaker evidence of benefit. These were evaluated in patients with different types of cancer, undergoing different types of cancer treatment. Benefits may be restricted to the disease and treatment combinations evaluated