The Ontario Cancer Registry (OCR) and the Surveillance, Epidemiology and End Results (SEER) databases were used to describe temporal trends in the incidence and survival of squamous cancers of the upper aerodigestive tract (UADT) in Ontario and the US between 1984 and 2001. Between the 1984-86 and 1999-01 periods, the age-adjusted incidence rate of all first primary cancers of the UADT decreased from 11.6 (11.2-12.0) to 8.8 (8.5-9.1) in Ontario and 13.0 (12.7-13.3) to 10.2 (10.0-10.4) in the US. Significant decreases in incidence were observed in many UADT sites but there was no significant change in the incidence of cancer of the oropharynx in either the US or Canada. Over the same period, the 5-year relative survival for all UADT cancers increased from 49.2% (47.2-51.2%) to 57.1%(55.0-59.1%) in Ontario and from 48.1% (46.9-49.3%) to 52.4% (51.2-53.6%) in the US. This significant improvement in the outcome of UADT cancer was largely due to a dramatic increase in the 5-year relative survival for cancers of the oropharynx from 31.1% (27.1-35.1%) to 53.6% (49.3-57.9%) in Ontario and from 35.3% (32.9-37.8%) to 51.0% (48.7-53.3%) in the US. Smaller increases in survival were observed in cancers of the oral cavity, nasopharynx, and hypopharynx, but there was no evidence of any increase in survival for cancer of the larynx. These results are consistent with the hypothesis that there has been a major change in the etiology of cancer of the oropharynx in Canada and the US and a concomitant change in its response to therapy. ' UICCKey words: head and neck cancer; cancer of the oropharynx; incidence; etiology; relative survival Cancer of the UADT remains a significant problem in North America. 1 Until recently, the use of tobacco and alcohol were considered to be the principal causes of UADT cancers in the developed countries. 2 The decline in smoking rates in recent decades has been associated with a reduction in the overall incidence of cancer of the UADT in the US. However, the incidence of cancer of the oropharynx has not decreased in parallel with that of other UADT cancers. 3,4 This has led to the hypothesis that a real decrease in the incidence of smoking-related cancers of the oropharynx may have been obscured by a simultaneous increase in the incidence of a new variant of the disease caused by human papilloma virus (HPV). [3][4][5][6][7][8][9] In a previous population-based study of UADT cancer over the period from 1982from to 1994 showed that the incidence of UADT cancers in Ontario, Canada was remarkably similar to that in the US. Smoking rates have been decreasing in Canada 11 as they have in the US, 3 but it is not yet known whether this has resulted in a decrease in the incidence of UADT cancer in Canada. The first objective of this study was to compare trends in the incidence of UADT cancers in Ontario and the US to determine: (a) whether the overall incidence of UADT cancer in Ontario has decreased as it has in the US; and (b) whether the temporal trend in the incidence of oropharyngeal cancer in Ontar...

Analyses of daytime fair-weather aircraft and surface-flux tower data from the May–June 2002 International H2O Project (IHOP_2002) and the April–May 1997 Cooperative Atmosphere Surface Exchange Study (CASES-97) are used to document the role of vegetation, soil moisture, and terrain in determining the horizontal variability of latent heat LE and sensible heat H along a 46-km flight track in southeast Kansas. Combining the two field experiments clearly reveals the strong influence of vegetation cover, with H maxima over sparse/dormant vegetation, and H minima over green vegetation; and, to a lesser extent, LE maxima over green vegetation, and LE minima over sparse/dormant vegetation. If the small number of cases is producing the correct trend, other effects of vegetation and the impact of soil moisture emerge through examining the slope ΔxyLE/ΔxyH for the best-fit straight line for plots of time-averaged LE as a function of time-averaged H over the area. Based on the surface energy balance, H + LE = Rnet − Gsfc, where Rnet is the net radiation and Gsfc is the flux into the soil; Rnet − Gsfc ∼ constant over the area implies an approximately −1 slope. Right after rainfall, H and LE vary too little horizontally to define a slope. After sufficient drying to produce enough horizontal variation to define a slope, a steep (∼−2) slope emerges. The slope becomes shallower and better defined with time as H and LE horizontal variability increases. Similarly, the slope becomes more negative with moister soils. In addition, the slope can change with time of day due to phase differences in H and LE. These trends are based on land surface model (LSM) runs and observations collected under nearly clear skies; the vegetation is unstressed for the days examined. LSM runs suggest terrain may also play a role, but observational support is weak.

Airborne vertically pointing Doppler radar data collected in 10 winter storms over the Medicine Bow Range in Wyoming are used to examine the importance of boundary layer (BL) turbulence for orographic precipitation growth. In all 10 cases, the cloud-base temperature was below 08C and the bulk Froude number was more than 1.0, implying little or no blocking of the flow by the mountain barrier. Seven of the 10 storms sampled were postfrontal, with weak static stability and relatively shallow cloud tops.Doppler vertical velocity transects depict an approximately 1-km-deep turbulent layer draped over the terrain, sometimes clearly distinct from the stratified flow in the free troposphere aloft, where vertical motion is largely controlled by gravity wave dynamics. Spectral analysis of near-surface Doppler vertical velocity data in terrain-following coordinates reveals an inertial subrange with decreasing power with height toward the BL top. The composite of radar data profiles from the 10 flights is analyzed in frequency-by-altitude diagrams, with altitude expressed above ground level. These diagrams indicate a wide range of vertical velocities in the BL, and rapid snow growth within the BL as air rises through the cloud base, especially when BL turbulence is more intense. This snow growth is concentrated on the windward side of mountains, above the terrain-cloud base intersection. The dominant snow growth mechanism in the BL (i.e., by accretion or vapor deposition) cannot be established because of restrictions in aircraft flight level over complex terrain. Snow aggregation may have contributed to the observed rapid increase in reflectivity in the BL along the windward slope.

No abstract

Vertical velocity characteristics of the optically clear convective boundary layer (CBL) are examined by means of profiling airborne radar data collected in the central Great Plains during the International H 2 O Project, May-June 2002 (IHOP 2002. Clear-air echoes are sufficiently strong for the radar, a 95-GHz cloud radar, to detect most of the CBL at a resolution of ϳ30 m. Vertical radar transects across the CBL are remarkably dominated by well-defined plumes of higher reflectivity. These echo plumes occupy most of the depth of the CBL in the developing and mature stages of the CBL. Gust probe data indicate that the plumes tend to correspond with ascending motion. Evidence exists in the literature, and arises from this study, that the clear-air scatterers are mostly small insects.The close-range Doppler radar velocities, some 100 m above and below the aircraft, are compared to gust probe vertical velocities after both are corrected for aircraft motion.It is found that the radar vertical velocities have a downward bias of 0.5 Ϯ 0.2 m s Ϫ1 on average. This bias is of the same sign as that reported in wind profiler data in the CBL, but it is larger. The difference between aircraft and radar vertical velocities becomes larger in stronger updrafts. This does not happen in cases where the scatterers are hydrometeors: hydrometeors fall out at their terminal velocity, which does not directly depend on updraft speed.The existence of the CBL echo plumes and radar "fine lines," sustained by low-level air convergence, has long been attributed to a biotic response to updrafts. This response has been assumed to be controlled by air temperature; that is, insects subside when they encounter cold air in the upper CBL. The authors propose that the biotic response is not temperature controlled but, rather, is dependent on the vertical displacement.