Long-term changes in tropospheric ozone

Tropospheric ozone changes are investigated using a selected network of surface and ozonesonde sites to give a broad geographic picture of long-term variations. The picture of long-term tropospheric ozone changes is a varied one in terms of both the sign and magnitude of trends and in the possible causes for the changes. At mid latitudes of the S.H. three time series of ∼20 years in length agree in showing increases that are strongest in the austral spring (August–October). Profile measurements show this increase extending through the mid troposphere but not into the highest levels of the troposphere. In the N.H. in the Arctic a period of declining ozone in the troposphere through the 1980s into the mid-1990s has reversed and the overall change is small. The decadal-scale variations in the troposphere in this region are related in part to changes in the lowermost stratosphere. At mid latitudes in the N.H., continental Europe and Japan showed significant increases in the 1970s and 1980s. Over North America rises in the 1970s are less than those seen in Europe and Japan, suggesting significant regional differences. In all three of these mid latitude, continental regions tropospheric ozone amounts appear to have leveled off or in some cases declined in the more recent decades. Over the North Atlantic three widely separated sites show significant increases since the late-1990s that may have peaked in recent years. In the N.H. tropics both the surface record and the ozonesondes in Hawaii show a significant increase in the autumn months in the most recent decade compared to earlier periods that drives the overall increase seen in the 30-year record. This appears to be related to a shift in the transport pattern during this season with more frequent flow from higher latitudes in the latest decade

In vivo validation of a three-dimensional optical method to document volumetric soft tissue changes of the interdental papilla

BACKGROUND: Non-surgical and surgical periodontal treatment may cause volumetric changes in the gingival contour. Many techniques have been suggested to minimize soft tissue shrinkage; however, there is a lack of three-dimensional (3D) quantitative data comparing different treatment approaches. The aim of the present study was to clinically validate an easy-to-use chair-side procedure to document volumetric changes in the interdental papilla region. METHODS: Nine volunteers participated in the study. A thin layer of a flowable composite resin material was applied on a papilla and volumetrically analyzed using the clinical chair-side computer-aided design/computer-aided machining (CAD/CAM) 3D method. To accurately measure the applied volumes, the composite resin volume was also determined using microcomputed tomography (micro-CT) and weight measurements. In addition, inter- and intraexaminer differences were evaluated in the same manner using a dental training unit (phantom head) to simulate clinical conditions. RESULTS: No statistically significant difference was found between the results obtained by micro-CT and the weight measurements. The CAD/CAM 3D method showed a significant underestimation of the composite resin volume (P = 0.0047) compared to micro-CT, although the two methods correlated well (R(2) = 0.991). High accuracy was found when inter- and intraexaminer differences were evaluated, showing a concordance correlation coefficient of 0.99. CONCLUSION: CAD/CAM 3D device and software are an easy-to-use chair-side method to document changes in soft tissues

Equatorial dynamics observed by rocket, radar and satellite during the CADRE/MALTED campaign, 2: Mean and wave structures, coherence, and variability

We present an analysis of the wind and temperature measurements made by rocket, radar, and satellite instrumentation in the equatorial and subtropical middle atmosphere accompanying the MALTED/CADRE campaign conducted at Alcantara, Brazil during August 1994. Measured mean winds and temperatures extended from similar to 10 to 110 km, exhibited general consistency between instruments, and revealed an oscillatory nature of the mean zonal wind with altitude at equatorial latitudes. MF radar measurements of tidal structures showed these to exhibit variability on similar to 8- and 16-day periods, but to be largely uncorrelated in time. Two-day wave structures displayed the same periodicities, but were well correlated among sites at northern and equatorial latitudes. Rocket and radar measurements at smaller scales of motion revealed inertia-gravity waves having significant temporal coherence, quadrature correlations between components indicating clear directions of propagation, and momentum flux and mean wind correlations indicative of gravity wave filtering processes. Rochet estimates of diurnal tidal amplitudes suggest that the diurnal tide achieves convectively unstable amplitudes in the upper equatorial mesosphere.Fritts, DC; Hitchman, MH; Lieberman, RS; Reid, IM; Vincent, RA; Garten, JF; Riggin, DM; Goldberg, RA; Lehmacher, GA; Schmidlin, FJ; McCarthy, S; Kudeki, E; Fawcett, C

Tropospheric ozone from IASI: comparison of different inversion algorithms and validation with ozone sondes in the northern middle latitudes [Discussion paper]

This paper presents a first statistical validation of tropospheric ozone products derived from measurements of the IASI satellite instrument. Since the end of 2006, IASI (Infrared Atmospheric Sounding Interferometer) aboard the polar orbiter Metop-A measures infrared spectra of the Earth's atmosphere in nadir geometry. This validation covers the northern mid-latitudes and the period from July 2007 to August 2008. Retrieval results from four different sources are presented: three are from scientific products (LATMOS, LISA, LPMAA) and the fourth one is the pre-operational product distributed by EUMETSAT (version 4.2). The different products are derived from different algorithms with different approaches. The difference and their implications for the retrieved products are discussed. In order to evaluate the quality and the performance of each product, comparisons with the vertical ozone concentration profiles measured by balloon sondes are performed and lead to estimates of the systematic and random errors in the IASI ozone products (profiles and partial columns). A first comparison is performed on the given profiles; a second comparison takes into account the altitude dependent sensitivity of the retrievals. Tropospheric columnar amounts are compared to the sonde for a lower tropospheric column (surface to about 6 km) and a "total" tropospheric column (surface to about 11 km). On average both tropospheric columns have small biases for the scientific products, less than 2 Dobson Units (DU) for the lower troposphere and less than 1 DU for the total troposphere. The comparison of the still pre-operational EUMETSAT columns shows higher mean differences of about 5 DU.Since June 2007 funding from the Environmental Protection Agency (EPA, Reference Number: 2006-AQ-MS-50) has allowed Valentia Observatory to extend its Ozonesonde launches to a year round weekly programme

Signatures of murine B-cell development implicate Yy1 as a regulator of the germinal center-specific program

We utilized gene expression profiling of a comprehensive panel of purified developmentally defined normal murine B cells to identify unique transcriptional signatures for each subset. To elucidate transcription factor activities that function in a stage-specific fashion, we used gene sets that share transcription factor targets and found that germinal center B cells had a robust enrichment of up-regulated and down-regulated signatures compared with the other B-cell subsets. Notably, we found Yy1 and its targets to be central regulators of the germinal center B (GCB)-specific transcriptional program with binding of Yy1 to select signature genes in GCB cells, and translation of the Yy1 signatures to human GCB cells. We then tested whether our newly generated, stage-specific transcriptional signatures could be used to link murine lymphoma models to stages of normal B-cell development. Although each of the molecularly defined murine lymphoma models conserved certain stage-specific features of normal B-cell development, there was a significant alteration of the normal differentiation signature following malignant transformation. These findings offer important tools and insights for elucidating differences between normal and malignant B cells

Validation of 10-year SAO OMI Ozone Profile (PROFOZ) Product Using Ozonesonde Observations

We validate the Ozone Monitoring Instrument (OMI) ozone-profile (PROFOZ) product from October 2004 through December 2014 retrieved by the Smithsonian Astrophysical Observatory (SAO) algorithm against ozonesonde observations. We also evaluate the effects of OMI Row anomaly (RA) on the retrieval by dividing the data set into before and after the occurrence of serious OMI RA, i.e., pre-RA (2004-2008) and post-RA (2009-2014). The retrieval shows good agreement with ozonesondes in the tropics and mid-latitudes and for pressure ~50 hPa after applying OMI averaging kernels to ozonesonde data. The MBs of the stratospheric ozone column (SOC) are within 2% with SDs of ~50 hPa. The SOC MBs increase up to 3% with SDs as great as 6% and the TOC SDs increase up to 30%. The comparison generally degrades at larger solarzenith angles (SZA) due to weaker signals and additional sources of error, leading to worse performance at high latitudes and during the mid-latitude winter. Agreement also degrades with increasing cloudiness for pressure > ~100 hPa and varies with cross-track position, especially with large MBs and SDs at extreme off-nadir positions. In the tropics and mid-latitudes, the post-RA comparison is considerably worse with larger SDs reaching 2% in the stratosphere and 8% in the troposphere and up to 6% in TOC. There are systematic differences that vary with latitude compared to the pre-RA comparison. The retrieval comparison demonstrates good long-term stability during the pre-RA period, but exhibits a statistically significant trend of 0.14-0.7%/year for pressure < ~ 80 hPa, 0.7 DU/year in SOC and -0.33 DU/year in TOC during the post-RA period. The spatiotemporal variation of retrieval performance suggests the need to improve OMI’s radiometric calibration especially during the post-RA period to maintain the long-term stability and reduce the latitude/season/SZA and cross-track dependence of retrieval quality.Astronom