The partial pressure of atmospheric carbon dioxide (pCO2) has increased 31% since 1750 and is predicted to double by 2100. In the same time period the partial pressure of ozone (pO3) has also risen by approximately 36%. Net CO2 uptake rate (A) increases in elevated pCO2 , but with continued exposure the degree of stimulation is reduced, growth in ozone also reduces A. A build up foliar carbohydrates is implicated in the down-regulation of A in plants grown in elevated pCO2. Using Free Air gas Concentration Enrichment technology we measured carbohydrate content and export rate in soybeans grown in the field at the elevated partial pressures of CO2 (55Pa) and ozone (ambient x 1.5) predicted for 2050 and compared them with plants grown under current (pCO2, 37Pa) conditions. Measurements of carbohydrate content taken in parallel with measurements of A were used to calculate export rate by mass balance. These data are from three time points during the early to mid-season (pre-flowering) development of soybean. Throughout this period of development, growth in elevated pCO2 significantly increased the content of ethanol soluble carbohydrates (23.8% increase, P = 0.06) and starch (82.4%increase, P = 0.015) relative to soybeans grown in air or elevated pO3. There was no significant difference between carbohydrate content in soybeans grown in air and ozone enriched air (4.3 % increase, P = 0.52). The increase in total non-structural carbohydrate (TNC) content (ethanol soluble + starch) due to growth in elevated pCO2 was maintained throughout the period of study (45% increase ± 9% SE, P = 0.041). Despite significantly higher foliar carbohydrate contents in elevated pCO2, the daytime export rate was significantly higher (32%, P = 0.01) in all three stages studied in the soybeans grown in elevated pCO2 . During this early period of crop development there was no evidence of a significant effect of ozone on either carbohydrate content or export rate. This study was supported by a Battelle fellowship and the National Institutes of Health MARC program, grant #T34- GMO8655..

Observations of the Impacts of Forest Fire-Generated Aerosols on Incoming Solar Radiation.
Alicia Handy and Mark A. Miller, Earth Systems Science Division, Brookhaven National Laboratory.

In recent years, there has been an apparent increase in the frequency and size of forest fires in Canada. There may be multiple causes for this increase, including weather patterns, global change, and funding for fire control activities. These forest fires contribute aerosols, which are small, suspended particles, to the atmosphere. With this summer being both hot and dry in Canada, there have been widespread outbreaks of forest fires. Forest fires have a major impact on the aerosol concentration and solar radiation transfer in the atmosphere both locally and regionally. One such fire began burning on July 2, 2002 in Quebec, Canada and produced a smoke plume that traveled south over Long Island, New York. The radiative impacts of this particular plume were measured using sunphotometers, which are instruments that measure the aerosol optical thickness (AOT). The AOT is a coefficient that quantifies how much solar radiation was either scattered or absorbed by the particles as incoming photons interacted with the turbid atmosphere. Now…how much different was the AOT in the plume than on other days? In recent years, the need to control greenhouse gas emissions has greatly increased. The amount of greenhouse gasses that are emitted directly effects global climate patterns. The main objective of this research is to improve climate prediction models, which determine such future patterns as rainfall and temperature. Measurements of the aerosol optical thickness (AOT) are taken daily. Low AOT's are associated with clear days, where high AOT's (generally values close to 1 and above) represent polluted or cloudy days. Sunphotometers are one type of instrument used to calculate aot. The calculations are based on Beer's Law and the Langley Principle. Beer's Law states that I=(Io)e^(-tm), where I is the radiation received at the surface, Io is the radiation emitted by the sun, t is the total molecular thickness, and m is the inverse of the cosine of the solar zenith angle. The Langley Technique allows you to find the value of Io by extrapolating the line to 0 of the graph of m vs. ln(I). By measuring the incoming solar radiation, and knowing the radiation being emitted from the sun, one is able to calculate how much is being scattered by clouds, aerosols, and atmospheric molecules (t). Tau (t) is than broken into its components: Rayleigh scattering (molecular scattering), aerosols (AOT at various wavelengths), ozone (only effects 660nm), and clouds (dominant). This summer internship was supported by the WISE-Battelle Summer Fellowship Grant.

Development of the Raster imaging procedure in correlation with ion imaging spectroscopy.
Peter Hallock, Arthur Suits, Department of Chemistry, Brookhaven National Laboratories and State University of New York at Stony Brook.

Our development of a novel variant on ion imaging shows much promise to the scientific community. The process fundamentally relies upon two lasers: one to dissociate a molecule, and another to probe for the atomic fragments using a (2 + 1) Resonance Enhanced Multi-Photon Ionization (REMPI) scheme. Our laser light is passed through a high vacuum chamber, where it intercepts a molecular beam, which contains the molecule we wish to observe, in our case chlorine gas (Cl2) seeded in argon. The Cl2 molecule was chosen on account of its large absorption cross-section at a chosen dissociation wavelength of 355 nm. The dissociated neutral Cl atom is then probed for using 235 nm UV radiation generated by a dye laser. The now ionized Cl+ fragment is accelerated down a flight tube where it collides with our detector. These collisions are interpreted by computer software and generate a visual image of the photon dissociation event. From these images, we are able to theorize about what is happening on a molecular level, such as the angular momentum alignments of the chlorine atom's p orbitals. Figure 1 shows Cl+ ions produced from the Raster procedure. What appears to be a single ring, upon closer inspection, is actually two. The outer/horizontal ring correlates to the Cl+ which results from the photodissociation of Cl2 into Cl + Cl. The faint inner/vertical ring is the Cl+ ion that resulted from the photodissociation of Cl2 into Cl + Cl*; such an ion was unable to be resolved in conventional ion velocity imaging techniques. Hence, Raster imaging has enabled us to produce high-resolution images with experiments involving crossed polarization geometries. The old method required us to project the recoil onto the detector then reconstruct it by computer software. With Raster, the "slicing" actually allows us to see the recoil distribution directly without compromising resolution.
I would like to thank the people at Battelle for funding this summer research opportunity and also Professor Arthur Suits for giving me the opportunity to work with him and his group at the frontier of chemical dynamics.

TRAIL/Apo2 as a candidate soluble factor mediating bystander effect in irradiated endothelial co-cultures.
Yana Kleyner, WISE Program, SUNY Stony Brook, NY; Xinhua Lin, Y. Medical Department, Brookhaven National Laboratory, NY; Hong Lau, Dept. of Radiation Oncology, School of Medicine, SUNY Stony Brook, NY; Louis A. Peña, Medical Department, Brookhaven National Laboratory, NY.

The Bystander Effect is a phenomenon in which cells affected by an agent, such as ionizing radiation, convey manifestation of damage to other cells not directly targeted by the agent, mediated by communication directly between cells, such as gap junctions, or indirectly by soluble factors in a paracrine manner. This study was conducted to investigate the role of soluble factors in the Bystander Effect. Co?cultures of physically isolated cells were prepared by seeding normal human umbilical vein endothelial cells (HUVEC) in the upper chamber of Transwell® 24-well inserts; glioma cells (CNS-1, C6, U87, U343) or HUVECs were seeded in the lower chamber. HUVEC inserts were subjected to 10 Gy of ionizing radiation, and returned to the co-culture dish. After 30 hrs, the unirradiated cells in the lower chamber were fixed and stained with DNA stain Hoechst 33258. Apoptotic changes in nuclear morphology was quantified. CNS?1, U343 and C6 cell lines were unaffected, but U87 and HUVEC showed significant increases in the amount apoptosis due to the Bystander Effect. Separately, a DNA Microarray experiment was conducted with sublethally irradiated endothelial cells (HAEC). The resulting gene induction data was analyzed using SAM (Significant Analysis of Microarrays) software (Tusher et al., Proc Natl Acad Sci, 98:5116, 2001). By measuring the strength of statistical relationship between gene expression and response variable (e.g. radiation dose) SAM identifies significant genes, e.g., TRAIL/Apo2, a cytokine that serves as an extracellular signaling triggering apoptosis. To test whether TRAIL/Apo2 might mediate the Bystander Effect in HUVEC-glioma or HUVEC-HUVEC co?cultures; a polyclonal anti-TRAIL antibody (Chemicon, 10 ug/ml) was used in neutralization experiments. The amount of bystander apoptosis was reduced by 48% in HUVEC-HUVEC co-cultures. HUVECs are primary cell cultures, thus another aim was to characterize these phenomenon in an immortalized endothelial cell line, RMEC (rat microvascular endothelial cells), transformed by SV40 Large T-antigen. RMECs irradiated with increasing doses of ionizing radiation, showed linear increases of apoptosis. The apoptotic response was approximately equivalent to HUVEC. Thus this cell line may be employed for future studies. This work was supported by NIH grant K01?CA76483 and BNL/DOE LDRD 00?32 (L.A.P.), by SUNY Stony Brook School of Medicine TRO grant SBF296110 (Y.H.L.), and a Battelle/WISE summer fellowship.

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