David Kyle Johnson

The abdominal subcutaneous tissue: computed tomographic, magnetic resonance, and anatomical observations.

We have studied the fasciae of the abdominal subcutaneous layer by analyzing axial CT images taken at a level immediately superior to the iliac crests in 20 adult female patients. The pattern of the fascial planes seen at this level was compared with those seen on MRI and dissected cadaveric sections. We have demonstrated a circumferential subcutaneous fascial plane that divides the subcutaneous fat into a single superficial fat compartment and a single deep fat compartment.

Determination of the source areas contributing to regionally high warm season PM2.5 in eastern North America.

Abstract An ensemble-trajectory analysis technique known as Quantitative Transport Bias Analysis was applied to determine which geographic areas systematically contributed to above- and below-average fine particle mass (PM2.5) over eastern North America. Six-hour average measurements from 12 rural or suburban locations in eastern North America collected using a tapered element oscillating microbalance were individually associated with corresponding 3-day back-trajectories for the warm seasons (May–September) of 2000 and 2001. Much of the populated areas of northeastern North America were implicated in the build-up of PM2.5 to above-average concentrations. The finer structure of the Quantitative Transport Bias Analysis pattern indicated that transport from the Ohio River Valley, particularly the eastern portion of this area, was most often associated with the highest PM2.5 concentrations. In addition, air masses originating over a relatively large area from southeast Ohio to the western part of Virginia and the western Kentucky to central Tennessee area tended to result in relatively high PM2.5 concentrations over northeastern North America. These observation-based findings were consistent with the spatial distribution of the main sulfur dioxide emissions sources and the major oxides of nitrogen point sources.

Characterization and Identification of Trends in Average Ambient Ozone and Fine Particulate Matter Levels through Trajectory Cluster Analysis in Eastern Canada

Abstract In many locations in Eastern Canada, ambient levels of fine particulate matter (PM2.5) and surface ozone (O3) depend on airflow direction and synoptic scale meteorological conditions. In this study, a cluster analysis was performed on 10 yr (1994 –2003) of back-trajectory data for 11 locations in Eastern Canada, resulting in the identification of 10 unique back-trajectory clusters (or airflows) for each location. The airflows were then used to characterize and identify spatial and temporal trends in the daily maximum 8-hr average O3 (dmax 8-hr O3) and the daily average PM2.5 levels. Results showed that airflows from the southwest passing over Michigan and Southern Ontario were associated, on average, with the highest O3 levels at most locations in Eastern Canada.For PM2.5, the highest levels occurred with airflows from the Eastern Ohio River Valley. At major urban locations in Ontario and Quebec, the warm season mean (May to September) dmax 8-hr O3 and the annual mean PM2.5 were, on average, 12 parts per billion and 7.6 μg/m3 higher, respectively, than airflows from the north. Elevated levels of O3 and PM2.5 also occurred under light airflows, and, on average, the levels under light airflows were higher than their nonlight counterparts. At several locations in Canada, including Toronto, Montreal, Quebec City, and Kejimkujik, the annual warm season mean dmax 8-hr O3 experienced a statistically significant (95% confidence) increasing trend over the 10-yr period. When airflow direction was considered, a number of locations experienced statistically significant upward trends in O3 for airflow from the north and northwest. Several locations also showed significant upward trends associated with airflow from the southwest passing over Michigan and Southwestern Ontario. Although there are no statistically significant downward trends, airflows from the southwest have shown a reduction in O3 levels in Southwestern Ontario in more recent years.

Identification of representative warm season periods for regional air quality (ozone) model simulations

Abstract There is a need to apply detailed air quality models to examine the fate of air pollutant emissions over periods of a year or more so that issues which involve annual or even multi-year standards can be addressed. This is a difficult task due to computational and model input demands. In this study we examine multiple years of ozone and meteorological data for eastern Canada to determine how many warm seasons (May–September) would need to be modelled to ensure that the range of typical conditions in the warm season is included. We also evaluate how well individual warm seasons can match these conditions, assuming that if a single, typical warm season can be identified then it may be a good candidate for future modelling studies. We found that representation of the long-term average warm season O3 distribution, cumulative O3 statistics, surface weather conditions and frequency of synoptic-scale weather patterns with a combined absolute error of less than 20% requires, on average, five consecutive warm seasons. The number can be reduced to three through selection of specific consecutive warm seasons. The single most representative warm season matches the long-term conditions to within 26% in Ontario, 29% in Quebec and 30% in Nova Scotia and New Brunswick, while inclusion of a second year reduces these errors by 4, 7 and 2%, respectively. Beyond two years the reduction in error from adding more warm seasons occurs at an increasingly slower rate.

God, fatalism, and temporal ontology

Theological incompatibility arguments suggest Gods comprehensive foreknowledge is incompatible with human free will. Logical incompatibility arguments suggest a complete set of truths about the future is logically incompatible with human free will. Of the two, most think theological incompatibility is the more severe problem; but hardly anyone thinks either kind of argument presents a real threat to free will. I will argue, however, that sound theological and logical incompatibility arguments exist and that, in fact, logical incompatibly is the more severe problem. A deep analysis of the arguments will reveal that, to avoid a fatalist conclusion, we must reject bivalence and adopt a specific kind of temporal ontology (presentism), which also forces the theist to embrace open theism.

A DEBATE BETWEEN A THEIST AND A SANTA CLAUSIST (ACT II)

In Act I, Faith and Klaus had it out regarding whether their deity of choice – God and Santa respectively – exists. Although Klaus was unable to convince Faith, Klaus suggested that Krampus, his ‘Santa pastor’ (the guy who owns the mall where he buys his Christmas presents), will set Faith straight. We join the dialogue, once again, as Faith is about to first meet Krampus, who promises to provide us with more sophisticated arguments in favor of Santa Claus.

DOES FREE WILL EXIST

In ‘Do Souls Exist’, I suggested that, while the non-existence of the soul does threaten free will, the threat it possess is inconsequential. Free will faces so many other hurdles that, if those were overcome, the souls non-existence would be a non-threat. In this paper, I establish this; and to do so, I define the common libertarian notion of free will, and show how neuroscience, determinism, indeterminism, theological belief, axioms in logic, and even Einsteins theory of relativity each entail that libertarian free will does not exist. I conclude by demonstrating why some philosophers reject alternate (compatibilist) understandings of free will, and so believe that the notion we are free is an illusion.

DO SOULS EXIST

‘The soul hypothesis’ (the belief that souls exist and humans have them) enjoys near unanimous support in the general population. Among philosophers and scientists, however, belief in the soul is far less common. The purpose of this essay to explain why many philosophers and scientists reject the soul hypothesis and to consider what the non-existence of the soul would entail.