On the pulmonary toxicity of oxygen. 5. Electronic structure and the paramagnetic property of oxygen

Author Posting. © The Author(s), 2012. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Experimental and Molecular Pathology 93 (2012): 365-377, doi:10.1016/j.yexmp.2012.08.007.Oxygen uptake by the pulmonary circulation is a chemical reaction. The physicochemical attributesof oxygen are critical when studying pulmonary oxygen toxicity. Extent of lung injury depends onthe percentage of oxygen in an oxygen:nitrogen mix in polybaric circumstances (Shanklin, 1969). Further change in extent of lesion follows when other gases are used in the inhalant mix instead of nitrogen (Shanklin and Lester, 1972), with oxygen at 21-100% of the mix. Comparative subatmospheric oxygen levels down to 3% in hydrogen, helium, nitrogen, argon, or sulfurhexafluoride, were run with and without ventilatory distress by the Farber (1937) model, bilateralcervical vagotomy (BCV). This yielded coherent results indicating a need to consider molecular characteristics at the atomic level. Molecular mass and size, gas viscosity, and thermal conductivity yielded no obvious correlates to lung injury. Saturation of the outer electron shells of the diluents fit the empiric data, prospectively an interaction between oxygen and nitrogen from their electronegativity and closely approximate molecular mass, size, and shape. The lesion is essentially eliminated at 7% oxygen in nitrogen. At 3% oxygen, the least lesion is found with N2, H2, and SF6,all gases with incomplete outer electron shells, allowing for transient, possibly polarized, covalent bonding with oxygen as the significant minority component in the mix. Argon and helium do not interfere with oxygen. With 3% oxygen in argon without BCV, the experiments ran so long (>70hours) they were terminated once the point had been made. 3% oxygen in argon after BCV yielded a mean survival more than twice that of BCV in air, indicating a remarkable degree of nitrogen interference with oxygen in the respiratory medium of terrestrial animal life. Argon displayed other advantages for the lung compared to nitrogen. Hydrogen, nitrogen, and oxygen are diatomic molecules, a feature which does relate to the extent of lung injury, but only oxygen is paramagnetic. Magnetic effects on lesion formation were tested: [1] with ventilatory distress induced in newbornrabbits, and [2] in young adult female white mice exposed to 100% oxygen without addedmechanical distress. A noninvasive model for ventilatory distress, thoracic restraint (TR), withlonger mean survivals of 40-50 hours, was employed rather than the Farber model. Parallel runs with TR, one subset receiving 100% oxygen in a plastic chamber resting on six strong ring magnetswith measured fields up to +1200 gauss, the other plain 100% oxygen, were performed. Bothsubsets developed moderate metabolic acidosis with average weight losses circa 25%, but over different time courses, 82.89 ± 4.91 hours in magnetized oxygen, 55.4 per cent longer than the 53.34 ± 9.82 hours in plain oxygen ( p <0.001). The longer survival in magnetized oxygen meant extensive lung injury (99.57 ± 0.42% pleural surface, versus 83.86 ± 14.03%), but the rate of lesionformation was 30.89 per cent faster in plain oxygen (1.5722% per hour) than in magnetized oxygen(1.2012% per hour), a difference significant at p <0.001. The effect of oxygen without mechanical ventilatory distress was examined in female adult whitemice exposed to oxygen or magnetized oxygen. Similar survivals and weight losses were achieved. The rate of lung lesion formation was different, 1.2617% per hour in plain oxygen, 46.13 per centfaster than 0.8634% per hour in magnetized oxygen. A variable magnetic field, with animals moving and breathing in chambers flooded with oxygen, has both systemic and pulmonary effectswhich alter the rate of lesion formation due to oxygen toxicity. Paramagnetic oxygen in a magneticfield influences the effect of oxygen toxicity on the lung but at these strengths of field it does notovercome significant mechanical disturbance

On the pulmonary toxicity of oxygen : III. The induction of oxygen dependency by oxygen use

Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Experimental and Molecular Pathology 89 (2010): 36-45, doi:10.1016/j.yexmp.2010.05.004.Oxygen is central to the development of neonatal lung injury. The increase in oxygen exposure of the neonatal lung during the onset of extrauterine air breathing is an order of magnitude, from a range of 10-12 to 110-120 Torr. The contributions of oxygen and the volume and pressure relationships of ventilatory support to lung injury are not easily distinguished in the clinical setting. Sequential changes in inspired air or 100% oxygen were studied in 536 newborn rabbits without ventilatory support. Bilateral cervical vagotomies (BCV) were performed at 24 hours post natal to induce ventilatory distress which eventuates in hyaline membrane disease. The sequences applied yielded evidence for an induced state of oxygen dependency from oxygen use which was reflected in differences in survival and the extent of pulmonary injury. The median survival for animals kept in air throughout was 3 hours. Oxygen before vagotomy or during the first 3 hours afterwards extended the survival significantly but produced more extensive, more severe, and more rapid lung lesions. Returning animals to air after prior oxygen exposure reduced the number of survivors past 10 hours and shortened the maximum survival in those groups. These features indicate the development of a dependency of the defense mechanisms on the availability of oxygen at the higher level for metabolic and possibly other aspects of the pulmonary and systemic response to injury, beyond the usual physiological need. Subset analysis revealed additive and latent effects of oxygen and demonstrated a remarkable rapidity in onset of severe lesions under some circumstances, illustrating the toxicity of oxygen per se.John A. Hartford Foundation, New York, N.Y. 10022-171

Experimental restoration treatments for burn pile fire scars in conifer forests of the Front Range, Colorado

2014 Spring.Includes bibliographical references.Drastic changes in soil physical, chemical, and biotic properties following slash pile burning and their lasting effects on vegetation cover have been well documented in ecosystems worldwide. However, processes that inhibit burn scar recovery are poorly understood as are the means for their rehabilitation. This study compared plant and soil responses to a number of surface treatments designed to alter microclimate, moisture infiltration, and nutrient status of recently burned slash piles along the Front Range of Colorado. Hand-applied surface manipulation treatments including: scarification, woodchip mulch, and tree branch mulch were compared with untreated burn scars, both with and without addition of a native species seed mix at 19 sites. Pile burning effects were observed by comparing fire scar centers with unburned reference areas while restoration treatment effectiveness was observed by comparing treated scar centers with untreated scar centers. I found surface manipulations had little effect on vegetation recovery while seeding scars increased total plant biomass significantly. Woodchip mulch consistently increased soil moisture, decreased inorganic nitrogen availability, and inhibited plant regrowth in scars. Branch mulch and soil scarification showed no effect on plant regrowth and little effect on soil physical and chemical properties. Non-native species did not have a significant presence within slash scars and were no more prevalent in fire scar centers than reference conditions (unburned areas). Recommendations based upon results of this study include seeding native species in fire scars to promote native species reestablishment

Identification of Best Practices for Childhood Nutrition Education Interventions

Childhood obesity remains a major concern in the United States, as 17% of children and adolescents ages 2-18 are obese. Although changes in knowledge alone are not enough to change behavior, most successful nutrition interventions to reduce childhood obesity include nutrition education. The purpose of this study is to understand practices that impact the effectiveness of childhood nutrition education, and to identify expert opinions of essential best practices for childhood nutrition education. A literature review was conducted to identify previously established best practices for childhood nutrition education for 6-12 year olds. Eight sources were identified, and 33 best practices were cited. Ten members of a USDA multi-state research group reviewed the best practices and edits were made according to their feedback. Three practices were added, and four were deleted. In order to understand experts’ opinions about childhood nutrition education, an interview script was developed based on the revised list of best practices. Cognitive interviews were conducted with faculty members of the University of Tennessee, Knoxville Department of Public Health Nutrition, and Extension agents. Three practices were deleted, and eight practices were combined. To ensure clarity, a second round of cognitive interviews were conducted with the same interviewees. Four practices were added during this process. A total of 23 best practices were included in the subsequent interview and ranking process. Four experts received a list of the final 23 best practices and were asked to rank the top ten best practices. Through an interview, experts were asked to provide greater detail about each of the 23 practices, explaining and describing in their own words. Emerging concepts were documented in narrative form. Experts reviewed this document to ensure that the document represented their thoughts accurately. This study found that there is great variability among the literature and experts concerning best practices for childhood nutrition education interventions. In the future, best practices for specific settings and age groups should be established and disseminated in order to improve the effectiveness of childhood nutrition education interventions

Thyroid and adrenal factors in hyaline membrane disease

Author Posting. © The Author(s), 2011. Presented at Advances in inflammatory and fibrosing lung diseases. Sunday, April 10, 2011, Experimental Biology 2011, Washington, D.C.Pulmonary fibrosis implies antecedent lung injury which may or may not include inflammatory responses of the ordinary sort. The onset of breathing at mammalian birth is a different kind of lung injury, one occasioned by great physical stretch of the collapsed but moist fetal lung, and immediate exposure to over ten times the level of oxygen resident in the fetal organ. Access to a large archive, the perinatal mortality review from the Chicago Lying-In Hospital, has provided information very relevant to these questions, including the first regular documentation of the pulmonary lesion complex as related to clinical care: beginning in the late 1930s. The lesion complex is called hyaline membrane disease (HMD) from the condensation at the tissue:gas interface of protein exuded from the lung and its circulation

CHALLENGING NARRATIVES: KURDISH YOUNG ADULTS IN ISTANBUL AND CHICAGO

In this dissertation, I explore the interplay between youthful agency and state imposition. Specifically, drawing on 12 months of ethnographic fieldwork in Istanbul, Turkey and Chicago, Illinois, I investigate how young adults who have migrated within one state and to another are navigating the states and bureaucratic systems in which they live. My interlocutors hail from a state that is quintessentially twentieth century, by which I mean the state was established as a nation-state, promoted as existing for members of a particular ethno-linguistic identity, with a charismatic leader who inspired a cult of personality. This narrative of the state has reverberated down the generations and is central to the socio-political environment in which my interlocutors have lived their lives. I argue that ethno-nationalist states and the education systems they establish to train their citizenry do not necessarily produce loyal, docile subjects that conform to the state’s narrative of ideal citizens. Rather, as my case shows, the university environment can foster the development of activists who assert who they are in ethno-linguistic terms that challenge state narratives. My interlocutors are challenging the dominant ethno-nationalist narratives of a state that seeks to erase and silence them, as well as narratives of asylum seeking that rely on tropes of victimhood that do not reflect their lived experiences. In challenging these narratives, my interlocutors make emphatic assertions of their ethno-linguistic identity and strive for increased visibility. As Kurds in Turkey, my interlocutors have been subject to narratives perpetuated by the ethno-nationally assertive Turkish state and agents of the state, such as the military and the education system, that they do not have a history, they do not exist as a distinct ethno-linguistic group, and they are terrorists. It is these narratives my interlocutors are challenging. In both Istanbul and Chicago, they are engaged in making emphatic assertions of their Kurdishness. In Istanbul, this has included challenging dominant state narratives in university classrooms and through activities such as spray-painting Kurdish language graffiti in central locations in the city. In Chicago, this has included protesting in front of the Turkish Consulate and submitting narratives of the various forms of violence they endured at the hands of the Turkish state as part of their political asylum applications to the United States government. In migrating to the United States and applying for political asylum, my interlocutors continue to assert their Kurdish identities, pose challenges to the Turkish state, and demand visibility for themselves, and Kurds more broadly