Biochemistry Commons^™

Self-Aligned Mechanical Attachment Of Carbon Nanotubes To Silicon Dioxide Structures By Selective Silicon Dioxide Chemical-Vapor Deposition, Jed D. Whittaker, Ghaleb A. Husseini, Matthew A. Linford, Robert C. Davis, Markus Brink

Faculty Publications

A self-aligned thin-film deposition technique was developed to mechanically attach carbon nanotubes to surfaces for the fabrication of structurally robust nanotube-based nanomechanical devices. Single-walled carbon nanotubes were grown by thermal chemical-vapor deposition (CVD) across 150-nm-wide SiO2 trenches. The nanotubes were mechanically attached to the trench tops by selective silicon tetraacetate-based SiO2 CVD. No film was deposited on the nanotubes where they were suspended across the trenches.

Seasonal Variation And Ecosystem Dependence Of Emission Factors For Selected Trace Gases And Pm2.5 For Southern African Savanna Fires, S. Korontzi, Darold E. Ward, Ronald A. Susott, Robert J. Yokelson, C. O. Justice, Peter V. Hobbs, E.A. H. Smithwick, Wei Min Hao

Chemistry and Biochemistry Faculty Publications

[1] In this paper we present the first early dry season (early June-early August) emission factor measurements for carbon dioxide (CO₂), carbon monoxide (CO), methane (CH₄), nonmethane hydrocarbons (NMHC), and particulates with a diameter less than 2.5 μm (PM_2.5) for southern African grassland and woodland fires. Seasonal emission factors for grassland fires correlate linearly with the proportion of green grass, used as a surrogate for the fuel moisture content, and are higher for products of incomplete combustion in the early part of the dry season compared with later in the dry season. Models of …

Comprehensive Laboratory Measurements Of Biomass-Burning Emissions: 1. Emissions From Indonesian, African, And Other Fuels, Ted J. Christian, B. Kleiss, Robert J. Yokelson, R. Holzinger, P. J. Crutzen, Wei Min Hao, B. H. Saharjo, Darold E. Ward

Chemistry and Biochemistry Faculty Publications

[1] Trace gas and particle emissions were measured from 47 laboratory fires burning 16 regionally to globally significant fuel types. Instrumentation included the following: open-path Fourier transform infrared spectroscopy; proton transfer reaction mass spectrometry; filter sampling with subsequent analysis of particles with diameter <2.5 μm for organic and elemental carbon and other elements; and canister sampling with subsequent analysis by gas chromatography (GC)/flame ionization detector, GC/electron capture detector, and GC/mass spectrometry. The emissions of 26 compounds are reported by fuel type. The results include the first detailed measurements of the emissions from Indonesian fuels. Carbon dioxide, CO, CH₄, NH₃, HCN, methanol, and acetic acid were the seven most abundant emissions (in order) from burning Indonesian peat. Acetol (hydroxyacetone) was a major, previously unobserved emission from burning rice straw (21–34 g/kg). The emission factors for our simulated African fires are consistent with field data for African fires for compounds measured in both …

Tolerance Of The Fetus By The Maternal Immune System: Role Of Inflammatory Mediators At The Feto-Maternal Interface, Colette Kanellopoulos-Langevin, Stephane M. Caucheteux, Philippe Verbeke, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

The adaptive immune system of placental mammals has evolved to tolerate the fetus. Rejection of the fetus by adaptive immune responses is therefore a rare event, with abortion being caused more frequently by inflammation in the placenta. This review will cover recent aspects of immune privilege and the innate immune system at the feto-maternal interface, citing examples of the role played by microbial infections in fetal demise.

Disulfide Bond Formation Involves A Quinhydrone-Type Charge–Transfer Complex, James Regeimbal, Stefan Gleiter, Bernard L. Trumpower, Chang-Ang Yu

Dartmouth Scholarship

The chemistry of disulfide exchange in biological systems is well studied. However, the detailed mechanism of how oxidizing equivalents are derived to form disulfide bonds in proteins is not clear. In prokaryotic organisms, it is known that DsbB delivers oxidizing equivalents through DsbA to secreted proteins. DsbB becomes reoxidized by reducing quinones that are part of the membrane-bound electron-transfer chains. It is this quinone reductase activity that links disulfide bond formation to the electron transport system. We show here that purified DsbB contains the spectral signal of a quinhydrone, a charge-transfer complex consisting of a hydroquinone and a quinone in …

Blood Lead Levels During Pregnancy And Pregnancy Outcome In Karachi Women, A Rahman, A Hakeem

Department of Biological & Biomedical Sciences

objective: To evaluate association of blood lead levels with pregnancy outcome in the obstetrics and gynaecology unit.
Methods: Blood lead levels were measured in 73 pregnant women at the time of delivery and assessed its association with pregnancyoutcome.
Results: Mean maternal lead level was 9.91+/-4.44 mg/dL (range 2.28-36.35 mg/dL). Mothers of boys had significantly higher (p=0.013, one-tailed t test) blood lead levels (11.05+/-5.19) when compared to mothers of girls (8.74+/-3.18 mg/dL.
Conclusion: Maternal lead levels at the time of delivery showed no association with gestational age, birth weight, recumbent length, or head circumference.

Live And Let Die: Regulatory Mechanisms In Fas-Mediated Apoptosis, James Curtin, Thomas Cotter

Articles

Activation of Fas receptor by Fas ligand causes caspase 8 activation and apoptosis in cells and is an important mechanism by which normal tissue homeostasis and function are maintained. Activation of caspase 8 is preceded by the formation of a death-inducing signalling complex (DISC), and a number of redundant mechanisms regulate DISC formation in vivo. Fas receptor is widely expressed in tissues, and dysfunction of the regulatory mechanisms in Fas receptor signalling has been reported in several diseases including autoimmune disease and cancer. This review aims to identify and discuss the various mechanisms employed by cells to alter their sensitivity …

Defects In Death-Inducing Signalling Complex Formation Prevent Jnk Activation And Fas-Mediated Apoptosis In Du 145 Prostate Carcinoma Cells, James Curtin, Thomas Cotter

Articles

Androgen-independent prostate carcinomas are resistant to chemotherapy and cell lines derived from androgen-independent prostate carcinomas such as DU 145 cells are highly resistant to Fas-mediated apoptosis. The incubation of DU 145 cells with anti-Fas IgM agonistic antibody of Fas receptor fails to activate JNK, a stress kinase involved in regulating apoptosis. We have previously shown that JNK activation is sufficient and necessary to promote Fas-mediated apoptosis in DU 145 cells. We investigate the mechanisms by which JNK activation and apoptosis are abrogated. HSP27 is overexpressed in DU 145 cells and has previously been reported to sequester DAXX and prevent JNK …

Evaluation Of Adsorption Effects On Measurements Of Ammonia, Acetic Acid, And Methanol, Robert J. Yokelson, Ted J. Christian, Isaac T. Bertschi, Wei M. Hao

Chemistry and Biochemistry Faculty Publications

[1] We examined how adsorption and desorption of gases from inlets and a cell could affect the accuracy of closed-cell FTIR measurements of carbon dioxide (CO₂), carbon monoxide (CO), methane (CH₄), nitric oxide (NO), nitrogen dioxide (NO₂), methanol (CH₃OH), acetic acid (CH₃COOH), and ammonia (NH₃). When standards were delivered to the cell through a stainless steel inlet, temporarily reduced transmission was observed for CH₃OH and NH₃. However, a halocarbon wax coated inlet (normally used on the system) had excellent transmission (comparable to room temperature …

Magnetic Storage Device Using Induced Magnetic Reversal Of A Cobalt Element Array, Hanning Chen, Scott L. Whittenburg

Chemistry and Biochemistry Faculty Publications

The effects of the applied field, cell size, and cutting area on the ‘‘seed’’ induced magnetic reversal of a cobalt element array have been studied by a stochastic dynamic micromagnetics code using the Laudau–Lifshitz–Gilbert equation. Three magnetic reversal mechanisms under different magnitudes of the applied field have been investigated by examining the energy profiles. To minimize the effect of the thermal fluctuations on the switching time, an applied field with magnitude around 0.7 or 0.8 T and an element array with cutting area less than 10 nm X 10 nm are required. By using the smaller cellsize, the switching time …

A Role For Yip1p In Copii Vesicle Biogenesis, Matthew Heidtman, Catherine Z. Chen, Ruth N. Collins, Charles Barlowe

Dartmouth Scholarship

Yeast Ypt1p-interacting protein (Yip1p) belongs to a conserved family of transmembrane proteins that interact with Rab GTPases. We encountered Yip1p as a constituent of ER-derived transport vesicles, leading us to hypothesize a direct role for this protein in transport through the early secretory pathway. Using a cell-free assay that recapitulates protein transport from the ER to the Golgi complex, we find that affinity-purified antibodies directed against the hydrophilic amino terminus of Yip1p potently inhibit transport. Surprisingly, inhibition is specific to the COPII-dependent budding stage. In support of this in vitro observation, strains bearing the temperature-sensitive yip1-4 allele accumulate ER membranes …

Topographical Expression Of Class Ia And Class Ii Phosphoinositide 3-Kinase Enzymes In Normal Human Tissues Is Consistent With A Role In Differentiation, Soha Salama El Sheikh, Jan Domin, Prakitpunthu Tomtitchong, Paul Abel, Gordon Stamp, El-Nasir Lalani

Department of Pathology and Laboratory Medicine

Background: Growth factor, cytokine and chemokine-induced activation of PI3K enzymes constitutes the start of a complex signalling cascade, which ultimately mediates cellular activities such as proliferation, differentiation, chemotaxis, survival, trafficking, and glucose homeostasis. The PI3K enzyme family is divided into 3 classes; class I (subdivided into IA and IB), class II (PI3K-C2α, PI3K-C2β and PI3K-C2γ) and class III PI3K. Expression of these enzymes in human tissue has not been clearly defined.

Methods: In this study, we analysed the immunohistochemical topographical expression profile of class IA (anti-p85 adaptor) and class II PI3K (PI3K-C2α and PI3K-C2β) enzymes in 104 formalin-fixed, paraffin embedded …

Distributions Of Trace Gases And Aerosols During The Dry Biomass Burning Season In Southern Africa, Parikhit Sinha, Peter V. Hobbs, Robert J. Yokelson, Donald R. Blake, Song Gao, Thomas W. Kirschsetter

Chemistry and Biochemistry Faculty Publications

[1] Vertical profiles in the lower troposphere of temperature, relative humidity, sulfur dioxide (SO₂), ozone (O₃), condensation nuclei (CN), and carbon monoxide (CO), and horizontal distributions of twenty gaseous and particulate species, are presented for five regions of southern Africa during the dry biomass burning season of 2000. The regions are the semiarid savannas of northeast South Africa and northern Botswana, the savanna-forest mosaic of coastal Mozambique, the humid savanna of southern Zambia, and the desert of western Namibia. The highest average concentrations of carbon dioxide (CO₂), CO, methane (CH₄), O_{3 …}

N-Acetyl-Beta-D-Glucosaminidase In Acute Myocardial Infarction, M Perwaiz Iqbal, Khawar A. Kazmi, Hasan R. Jafri, Naseema Mehboobali

Department of Biological & Biomedical Sciences

The objective of the study was to investigate whether the lysosomal enzyme, N-Acetyl-beta-D-glucosaminidase (NAG) activity is increased in plasma of patients with acute myocardial infarction (AMI) and to determine if there is any association between plasma levels of NAG and severity of myocardial infarction (MI). NAG activity in plasma was monitored in 69 patients with AMI and 135 normal healthy subjects using a spectrofluorimetric method. A modified Aldrich ST elevation score was used to gauge the severity of MI in terms of size of the infarct. Plasma NAG levels in AMI patients and normal healthy subjects were found to be …

Metabolic Responses Of Shorebird Chicks To Cold Stress: Hysteresis Of Cooling And Warming Phases, Robert Ricklefs, Joseph Williams

Biology Department Faculty Works

We developed a protocol for determining the maximum rate of oxygen consumption of shorebird chicks (Scolopacidae and Charadriidae) in response to cold challenge. We first subjected the chicks to gradually decreasing temperatures until their metabolism peaked and began to decrease. We ended the cooling phase of a trial when a chick’s body temperature Tb had declined typically to 32–34°C. After this point, we gradually increased the temperature in the metabolism chamber until normal Tb values and thermoneutral resting metabolism were restored. We refer to this cycle as the down–up (DU) protocol. We estimated instantaneous oxygen consumption (V . O∑) using …

Cardiac Acceleration As A Marker Of Vagal Withdrawal In Heart Rate Control During Exercise In Humans, S S I Bokhari, H R. Ahmad, M M F Subhan, S A. Ali, M N. Khan

Department of Biological & Biomedical Sciences

Objective: To investigate whether the time rate of change in heart rate i.e. cardiac acceleration, during aerobic exercise in human subjects could be used to differentiate vagal withdrawal from sympathetic stimulation.Methods: Fifteen male subjects exercised on a bicycle ergometer at 50 Watts (Step 1), then 100 Watts (Step 2), for 2 minutes each.Results: Heart rate (HR) was monitored from a resting value (mean +/- SD) of 80.3 +/- 12.9 to 113.8 +/- 13.6 beats min-1 in Step 1. In Step 2 exercise, HR increased from 113.8 +/- 13.6 to 145 +/- 20 beats min-1. At the initiation of Step 1, …

Trace Gas Measurements In Nascent, Aged, And Cloud-Processed Smoke From African Savanna Fires By Airborne Fourier Transform Infrared Spectroscopy (Aftir), Robert J. Yokelson, Issac T. Bertschi, Ted J. Christian, Peter V. Hobbs, Darold E. Ward, Wei Min Hao

Chemistry and Biochemistry Faculty Publications

[1] We measured stable and reactive trace gases with an airborne Fourier transform infrared spectrometer (AFTIR) on the University of Washington Convair-580 research aircraft in August/September 2000 during the SAFARI 2000 dry season campaign in Southern Africa. The measurements included vertical profiles of CO₂, CO, H₂O, and CH₄ up to 5.5 km on six occasions above instrumented ground sites and below the TERRA satellite and ER-2 high-flying research aircraft. We also measured the trace gas emissions from 10 African savanna fires. Five of these fires featured extensive ground-based fuel characterization, and two were in the …

Perilipin A Is Essential For The Translocation Of Hormone-Sensitive Lipase During Lipolytic Activation. J Cell Biol, John Tansey

Chemistry Faculty Scholarship

A key step in lipolytic activation of adipocytes is the translocation of hormone-sensitive lipase (HSL) from the cytosol to the surface of the lipid storage droplet. Adipocytes from perilipin -null animals have an elevated basal rate of lipolysis compared with adipocytes from wild-type mice, but fail to respond maximally to lipolytic stimuli. This defect is downstream of the -adrenergic receptor–adenylyl cyclase complex. Now, we show that HSL is basally associated with lipid droplet surfaces at a low level in perilipin nulls, but that stimulated translocation from the cytosol to lipid droplets is absent in adipocytes derived from embryonic fibroblasts of …

Thickness Dependence Of Magnetic Blocking In Granular Thin Films With Interacting Magnetic Particles, Jian Qing Wang, Zhi Dong Zhao, Scott L. Whittenburg

Chemistry and Biochemistry Faculty Publications

Interparticle interaction among single domain nanosize magnetic particles embedded in nonmagnetic matrix was studied. Attention was paid to concentrated Cu–Co granular thin films with a fixed magnetic volume fraction (20%). By analyzing theoretical models and comparing with experimental results, a dimensional constraint on the magnetic properties was found. As the film thickness reduces toward the thin limit the interparticle interaction plays important roles in modifying the magnetic behavior. The dipolar interaction energy was calculated among magnetic particles including far-neighbor interaction for films with different thickness values. When magnetization variation is included in the calculation, the resulting calculated interaction energy versus …

Evaluating The Effects Of Enhanced Processivity And Metal Ions On Translesion Dna Replication Catalyzed By The Bacteriophage T4 Dna Polymerase, Edmunds Z. Reineks, Anthony J. Berdis

Chemistry Faculty Publications

The fidelity of DNA replication is achieved in a multiplicative process encompassing nucleobase selection and insertion, removal of misinserted nucleotides by exonuclease activity, and enzyme dissociation from primer/templates that are misaligned due to mispairing. In this study, we have evaluated the effect of altering these kinetic processes on the dynamics of translesion DNA replication using the bacteriophage T4 replication apparatus as a model system. The effect of enhancing the processivity of the T4 DNA polymerase, gp43, on translesion DNA replication was evaluated using a defined in vitro assay system. While the T4 replicase (gp43 in complex with gp45) can perform …

Lysosomal Membrane Permeabilization Induces Cell Death In A Mitochondrion-Dependent Fashion, Patricia Boya, Karine Andreau, Delphine Poncet, Naoufal Zamzami, Jean-Luc Perfettini, Didier Metivier, David M. Ojcius, Marja Jäättelä, Guido Kroemer

All Dugoni School of Dentistry Faculty Articles

A number of diseases are due to lysosomal destabilization, which results in damaging cell loss. To investigate the mechanisms of lysosomal cell death, we characterized the cytotoxic action of two widely used quinolone antibiotics: ciprofloxacin (CPX) or norfloxacin (NFX). CPX or NFX plus UV light (NFX*) induce lysosomal membrane permeabilization (LMP), as detected by the release of cathepsins from lysosomes. Inhibition of the lysosomal accumulation of CPX or NFX suppresses their capacity to induce LMP and to kill cells. CPX- or NFX-triggered LMP results in caspase-independent cell death, with hallmarks of apoptosis such as chromatin condensation and phosphatidylserine exposure on …

Characterizing Conformational Changes Along The Dimerization Helix Of The Global Regulator, Fnr, Using Fluorescence Spectroscopy, Melanie Zupancic '03

Honors Projects

The FNR protein is a transcription factor that allows Escherichia coli to undergo anaerobic cellular respiration. It is known to positively regulate the expression ofseveral genes required for anaerobic respiration as well as negatively regulate genes responsible for aerobic respiration. Consequently, FNR is active under anaerobic conditions and inactive under aerobic conditions. Although the tertiary structure ofFNR is unknown, previous studies have indicated that FNR is inactive in the monomeric state and active in the dimeric state. Thus, it is believed that in anaerobic conditions, FNR undergoes a confonnational change from the monomeric to dimeric state. The mechanism involved in …

Preparation Of 2s,3s-N-Isobutyl-N-(2-Hydroxy-3-Amino-4-Phenylbutyl)-P-Nitrobenzenesulfonylamide Hydrochloride And Other Derivatives Of 2-Hydroxy-1,3-Diamines, Aslam A. Malik, Hasan Palandoken, Joy A. Stringer, Roland P. Carlson, John Leach, Thomas G. Archibald, Robert G. Miotke

Chemistry and Biochemistry

The present invention provides a new process for the preparation of 2S,3S-N-isobutyl-N-(2-hydroxy-3-amino-4phenylbutyl)- p-nitrobenzenesulfonylamide hydrochloride, wherein this compound is prepared directly from the chloromethylalcohol. Importantly, the process of the present invention results in higher yields of 2S,3S-N-isobutyl-N-(2hydroxy -3 -amino -4-phenylbutyl) -pnitrobenzenesulfonylamide hydrochloride without sacrificing its purity. The processes of the present inventin can be used to prepare not only the 2S,3S-derivative, but also the 2R,3S-, 2S,2R- and the 2R,3R-derivatives.

Clean, High-Yield Preparation Of S,S- And R,S- Amino Acid Isosteres, Aslam A. Malik, Todd E. Clement, Hasan Palandoken, James Robinson Iii, Joy A. Stringer

Chemistry and Biochemistry

The present invention provides compounds and methods that can be used to convert the intermediate halomethyl ketones (HMKs), e.g., chloromethyl ketones, to the corresponding S,S- and R,S-diastereomers. More particularly, the present invention provides: (1) reduction methods; (2) inversion methods; and (3) methods involving the epoxidation of alkenes. Using the various methods of the present invention, the R,S-epoxide and the intermediary compounds can be prepared reliably, in high yields and in high purity.

Tropospheric Carbon Monoxide Measurements From The Scanning High-Resolution Interferometer Sounder On 7 September 2000 In Southern Africa During Safari 2000, W. W. Mcmillan, M. L. Mccourt, H. E. Revercomb, R. O. Knuteson, Ted J. Christian, B. G. Doddridge, Peter V. Hobbs, J. V. Lukovich, P. C. Novelli, S. J. Piketh, L. Sparling, D. Stein, R. J. Swap, Robert J. Yokelson

Chemistry and Biochemistry Faculty Publications

[1] Retrieved tropospheric carbon monoxide (CO) column densities are presented for more than 9000 spectra obtained by the University of Wisconsin-Madison (UWis) Scanning High-Resolution Interferometer Sounder (SHIS) during a flight on the NASA ER-2 on 7 September 2000 as part of the Southern African Regional Science Initiative (SAFARI 2000) dry season field campaign. Enhancements in tropospheric column CO were detected in the vicinity of a controlled biomass burn in the Timbavati Game Reserve in northeastern South Africa and over the edge of the river of smoke in south central Mozambique. Relatively clean air was observed over the far southern coast …

Emissions Of Trace Gases And Particles From Savanna Fires In Southern Africa, Parikhit Sinha, Peter V. Hobbs, Robert J. Yokelson, I. T. Bertschi, Donald R. Blake, Isobel J. Simpson, Song Gao, Thomas W. Kirschsetter, Tica Novakov

Chemistry and Biochemistry Faculty Publications

[1] Airborne measurements made on initial smoke from 10 savanna fires in southern Africa provide quantitative data on emissions of 50 gaseous and particulate species, including carbon dioxide, carbon monoxide, sulfur dioxide, nitrogen oxides, methane, ammonia, dimethyl sulfide, nonmethane organic compounds, halocarbons, gaseous organic acids, aerosol ionic components, carbonaceous aerosols, and condensation nuclei (CN). Measurements of several of the gaseous species by gas chromatography and Fourier transform infrared spectroscopy are compared. Emission ratios and emission factors are given for eight species that have not been reported previously for biomass burning of savanna in southern Africa (namely, dimethyl sulfide, methyl nitrate, …

Role Of Proapoptotic Bax In Propagation Of Chlamydia Muridarum (The Mouse Pneumonitis Strain Of Chlamydia Trachomatis) And The Host Inflammatory Response, Jean-Luc Perfettini, David M. Ojcius, Charles W. Andrews Jr., Stanley J. Korsmeyer, Roger G. Rank, Toni Darville

All Dugoni School of Dentistry Faculty Articles

The BCL-2 family member BAX plays a critical role in regulating apoptosis. Surprisingly, bax-deficient mice display limited phenotypic abnormalities. Here we investigate the effect of BAX on infection by the sexually transmitted pathogen,Chlamydia muridarum (the mouse pneumonitis strain ofChlamydia trachomatis). Bax −/−cells are relatively resistant to Chlamydia-induced apoptosis, and fewer bacteria are recovered after two infection cycles from Bax −/− cells than from wild-type cells. These results suggest that BAX-dependent apoptosis may be used to initiate a new round of infection, most likely by releasingChlamydia-containing apoptotic bodies from infected cells that could be internalized by neighboring uninfected cells. Nonetheless, infected …

Purified Particulate Methane Monooxygenase From Methylococcus Capsulatus (Bath) Is A Dimer With Both Mononuclear Copper And A Copper-Containing Cluster, Raquel L. Lieberman, Deepak B. Shrestha, Peter E. Doan, Brian M. Hoffman, Timothy L. Stemmler, Amy C. Rosenzweig

Biochemistry and Molecular Biology Faculty Publications

Particulate methane monooxygenase (pMMO) is a membrane-bound enzyme that catalyzes the oxidation of methane to methanol in methanotropic bacteria. Understanding how this enzyme hydroxylates methane at ambient temperature and pressure is of fundamental chemical and potential commercial importance. Difficulties in solubilizing and purifying active pMMO have led to conflicting reports regarding its biochemical and biophysical properties, however. We have purified pMMO from Methylococcus capsulatus (Bath) and detected activity. The purified enzyme has a molecular mass of ~200 kDa, probably corresponding to an a2b2g2 polypeptide arrangement. Each 200 kDa pMMO complex contains 4.8 ± 0.8 copper ions and 1.5 ± 0.7 …

Characterization Of A Gene Encoding Two Isoforms Of A Mitochondrial Protein Upregulated By Cyclosporin A In Activated T Cells, Laurent Mascarell, Rodolphe Auger, Andres Alcover, David M. Ojcius, Thomas Jungas, Veronique Cadet-Daniel, Jean M. Kanellopoulos, Paolo Truffa-Bacchi

All Dugoni School of Dentistry Faculty Articles

Cyclosporin A (CSA) is an immunosuppressor used in organ transplantation. A recent proteomic analysis has revealed that activation of T cells in the presence of CSA induces the synthesis of hundreds of new proteins. Here we used representational difference analysis to characterize some of the corresponding induced genes. After cDNA bank screening we focused on one of these genes, which we named CSA-conditional, T cell activation-dependent (CSTAD) gene. This gene produces two mRNAs resulting from alternative splicing events. They encode two proteins of 104 and 141 amino acids, CSTADp-S and CSTADp-L, for the short and long forms, respectively. FK506 had …

Evolution Of Gases And Particles From A Savanna Fire In South Africa, Peter V. Hobbs, Parikhit Sinha, Robert J. Yokelson, Ted J. Christian, Donald R. Blake, Song Gao, Thomas W. Kirschsetter, Tica Novakov, Peter Pilewskie

Chemistry and Biochemistry Faculty Publications

[1] Airborne measurements of particles and gases from a 1000-ha savanna fire in South Africa are presented. These measurements represent the most extensive data set reported on the aging of biomass smoke. The measurements include total concentrations of particles (CN), particle sizes, particulate organic carbon and black carbon, light-scattering coefficients, downwelling UV fluxes, and mixing ratios for 42 trace gases and 7 particulate species. The ratios of excess nitrate, ozone, and gaseous acetic acid to excess CO increased significantly as the smoke aged over ∼40–45 min, indicating that these species were formed by photochemistry in the plume. For 17 other …