The majority of patients with multiple myeloma have translocations involving the immunoglobulin heavy chain switch regions on chromosome 14q32 and a promiscuous range of partner chromosomes. We describe a patient with an insertion of 132 bp of chromosome 22q12 sequence into the 5' region flanking S(mu) on chromosome 14q32. The 132 bp region from chromosome 22q12 contains the whole of exon 3 from a novel gene of unknown function in man. The significance of such insertional events remains unclear. The description of insertional events occurring as a result of abnormal switch recombination suggests that, in myeloma, dysregulation of oncogenes may occur by a mechanism other than chromosomal translocation.

Semiconducting single-wall carbon nanotubes have an absorption band centered about approximately 0.7 eV. This arises from the transition between the first valence band Van Hove singularity and the first conduction band singularity in the density of states. These singularities lie close enough to the Fermi-level that it is possible to shift the Fermi-level sufficiently to exclude this electronic transition. In this experiment an attempt has been made to demonstrate the optical switching of this absorption band by applying a gating potential. The experiment is in progress and results are pending. Carbon nanotubes were discovered in 1991 by Sumio Iijima at NEC Fundamental

Background-Medium chain acyl-CoA dehydrogenase (MCAD) deficiency is the most common inborn error of fatty acid metabolism. Undiagnosed, it has a mortality rate of 20-25%. Neonatal screening for the disorder is now possible but it is not known whether this would alter the prognosis.Objective-To investigate the outcome of MCAD deficiency after the diagnosis has been established. Method-All patients with a proved diagnosis of MCAD deficiency attending one centre in a four year period were reviewed.Results-Forty one patients were identified. Follow up was for a median of 6.7 years (range, 9 months to 14 years). Nearly half of the patients were admitted to hospital with symptoms characteristic of MCAD deficiency before the correct diagnosis was made. After diagnosis, two patients were admitted to hospital with severe encephalopathy but there were no additional deaths or appreciable morbidity. There was a high incidence (about one fifth) of previous sibling deaths among the cohort.Conclusions-Undiagnosed, MCAD deficiency results in considerable mortality and morbidity. However, current management improves outcome, supporting the view that the disorder should be included in newborn screening programmes.

Highly precise measurements of CO2 mixing ratios were recorded aboard both the NASA DC‐8 and P3‐B aircraft during the Pacific Exploratory Mission‐Tropics conducted in August‐October 1996. Data were obtained at altitudes ranging from 0.1 to 12 km over a large portion of the South Pacific Basin representing the most geographically extensive CO2 data set recorded in this region. These data along with CO2 surface measurements from the National Oceanic and Atmospheric Administration/Climate Monitoring and Diagnostics Laboratory (NOAA/CMDL) and the National Institute of Water and Atmospheric Research (NIWA) were examined to establish vertical and meridional gradients. The CO2 spatial distribution in the southern hemisphere appeared to be largely determined by interhemispheric transport as air masses with depleted CO2 levels characteristic of northern hemispheric air were frequently observed south of the Intertropical Convergence Zone. However, regional processes also played a role in modulating background concentrations. Comparisons of CO2 with other trace gases indicated that CO2 values were influenced by continental sources. Large scale plumes from biomass burning activities produced enhanced CO2 mixing ratios within the lower to midtroposphere over portions of the remote Pacific. An apparent CO2 source was observed in the NOAA/CMDL surface data between 15°N and 15°S and in the lower altitude flight data between 8°N and 8.5°S with a zone of intensity from 6.5°N to 1°S. Inferred from these data is the presence of a Southern Ocean sink from south of 15°S having two distinct zones seasonally out of phase with one another.

Exhaust measurements in the wake vortex regime of the NASA Boeing 757 aircraft were made during the SUbsonic aircraft: Contrails and Cloud Effects Special Study. Emission indices for NO and NOy were calculated from in situ measurements taken on board the NASA DC‐8 for plumes aged 20–300 seconds. The average NO emission index is 7.5 g NO2/kg fuel for mean conditions of 37 kft altitude, 0.7 Mach and 0.34 kg/s fuel flow rate. Comparison is made between measured indices and predictions based on ground engine test data and a fuel flow model. Measurements are positively correlated but are on average 22% higher than predictions, with considerable scatter and systematic deviations in measurements made under low thrust conditions. These conditions are lower than typical in commercial cruise operation of the 757, for which the model was optimized. No statistically significant change in nitrogenous emissions is observed for an order of magnitude change in fuel sulfur content. Estimation of the NO2 from photochemical calculations implies a contribution to NOx of 5–19%. Examination of exhaust composition shows that 95% of the NOy is in the form of NOx.

The hydroxyl (OH) and hydroperoxyl (HO2) radicals were measured for the first time throughout the troposphere and in the lower stratosphere with a new instrument aboard the NASA DC‐8 aircraft during the 1996 SUCCESS mission. Typically midday OH was 0.1‐0.5 pptv and HO2 was 3‐15 pptv. Comparisons with a steady‐state model yield the following conclusions. First, even in the lower stratosphere OH was sensitive to the albedo of low clouds and distant high clouds. Second, although sometimes in agreement with models, observed OH and HO2 were more than 4 times larger at other times. Evidence suggests that for the California upper troposphere on 10 May this discrepancy was due to unmeasured HOx sources from Asia. Third, observed HO2/OH had the expected inverse dependence with NO, but was inexplicably higher than modeled HO2/OH by an average of 30%. Finally, small‐scale, midday OH and HO2 features were strongly linked to NO variations.

We compare measurements of six species taken aboard NASA DC-8 and ER-2 aircraft during two flight legs in the tropical middle troposphere near Hawaii. NO, NOy. O-3, CH4, and N2O measurements agree to within the limits set by the known systematic errors. For CO2, which can be measured with better relative precision than the other five species, differences in measured values from the two platforms are slightly larger than expected if the air masses sampled by the two aircraft were indeed similar in CO2 composition to better than 0.08%.

We report the first measurements of CO, CH4, N2O, CO2, and H2O(g) in the exhaust trails of T‐39, B‐757, and DC‐8 aircraft at cruise conditions. Emission indices (EI) derived from these in‐situ measurements are presented. Results are in agreement with ground‐based tests indicating aircraft act as a net sink for CH4 and recent airborne in‐situ measurements that N2O is not an important exhaust constituent. Condensation of H2O(g) on exhaust particles resulted in EI(H2O(g)) values less than those expected from the combustion of fuel alone. Observed apparent negative EI(H2O(g)) values suggest that aircraft aerosol emissions, under unique atmospheric conditions, seed cloud formation and lead to dehydration of the exhaust‐influenced air parcel. Such conditions may induce the formation of cirrus clouds from persistent contrails. Comparisons with the Boeing EMIT Code show measurement‐derived CO emission index values consistent with model evaluations.

The Pacific Exploratory Mission‐West B (PEM‐West B) explored atmospheric layer structure using measurements of O3, H2O, CO, and CH4 from the NASA DC‐8 fast‐response instruments. The mission took place in February‐March 1994 over the western Pacific, mainly in the northern hemisphere. Results were compared with similar measurements made during the Pacific Exploratory Mission‐West A (PEM‐West A) in September‐October 1991. PEM‐West B sampled 94 vertical profiles, with an average atmospheric depth per profile of 6.4 km, and this sampling yielded 254 discrete layers. PEM‐West A sampled 105 profiles, also with a 6.4 km average depth, yielding 538 layers. Both missions revealed that layers containing high ozone and low water vapor were the most abundant, and low ozone and high water vapor layers were the next most abundant. Lidar images and potential vorticity cross sections showed the former associated with subsidence from the stratosphere in middle latitudes, spreading into the tropics. The latter was associated with convection from the boundary layer. The partition among different types of layers only changed slightly in the two missions, although PEM‐West B had half as many layers. Compared to PEM‐West A, PEM‐West B showed only one‐third the number of layers associated with polluted continental air. However, PEM‐West B revealed significantly more layers showing characteristics of descended clean marine air. In some cases these layers originated from the southern hemisphere. For ozone‐ and water‐vapor‐rich layers, the ozone deviation amplitude was higher in low latitudes and lower in high latitudes in PEM‐West B. The mean thickness of layers increased from about 450 m in PEM‐West A to 680 m in PEM‐West B. Layers also existed in the Intertropical Convergence Zone. CO2 measurements had sufficient vertical resolution to show layer structure as well.

Nonmethane hydrocarbons (NMHCs) and halocarbons were measured in the troposphere over the northwestern Pacific as part of the airborne component of NASA's Pacific Exploratory Mission‐West Phase B (PEM‐West B). This study took place in late winter of 1994, a period characterized by maximum outflow from the Asian continent. The results are compared to those from Pacific Exploratory Mission‐West Phase A (PEM‐West A), which was flown in the same region during late summer of 1991, when flow from the subtropical western Pacific dominated the lower troposphere. Mixing ratios of NMHCs, tetrachloroethene (C2Cl4), and methyl bromide (CH3Br) were significantly higher during PEM‐West B than during PEM‐West A, particularly at latitudes north of 25°N and altitudes lower than 6 km. The primary reasons for these higher ambient concentrations were the seasonal increase in the atmospheric lifetimes of trace gases controlled by HO radical reactions, and the more frequent input of continental air masses. During PEM‐West B, air masses of continental origin observed north of 25°N latitude were augmented with urban signature gases such as C2Cl4. By contrast, more southerly continental outflow had characteristics associated with combustion sources such as biomass burning, including wood fuel burning. During the summer PEM‐West A period, the spatial distribution of methyl iodide (CH3I) was consistent with effective oceanic sources at all latitudes, being especially strong in tropical and subtropical regions. At low latitudes, PEM‐West B CH3I mixing ratios in the lower troposphere were similar to PEM‐West A, but at latitudes greater than about 25°N PEM‐West B concentrations were significantly reduced. Equatorial regions exhibited enhanced CH3I mixing ratios extending into the upper tropical troposphere, consistent with fast vertical transport of air from the tropical marine boundary layer.

We report here measurements of the acidic gases nitric (HNO3), formic (HCOOH), and acetic (CH3COOH) over the western Pacific basin during the February‐March 1994 Pacific Exploratory Mission‐West (PEM‐West B). These data were obtained aboard the NASA DC‐8 research aircraft as it flew missions in the altitude range of 0.3–12.5 km over equatorial regions near Guam and then further westward encompassing the entire Pacific Rim arc. Aged marine air over the equatorial Pacific generally exhibited mixing ratios of acidic gases <100 parts per trillion by volume (pptv). Near the Asian continent, discrete plumes encountered below 6 km altitude contained up to 8 parts per billion by volume (ppbv) HNO3 and 10 ppbv HCOOH and CH3COOH. Overall there was a general correlation between mixing ratios of acidic gases with those of CO, C2H2, and C2Cl4, indicative of emissions from combustion and industrial sources. The latitudinal distributions of HNO3 and CO showed that the largest mixing ratios were centered around 15°N, while HCOOH, CH3COOH, and C2Cl4 peaked at 25°N. The mixing ratios of HCOOH and CH3COOH were highly correlated (r2 = 0.87) below 6 km altitude, with a slope (0.89) characteristic of the nongrowing season at midlatitudes in the northern hemisphere. Above 6 km altitude, HCOOH and CH3COOH were marginally correlated (r2 = 0.50), and plumes well defined by CO, C2H2, and C2Cl4 were depleted in acidic gases, most likely due to scavenging during vertical transport of air masses through convective cloud systems over the Asian continent. In stratospheric air masses, HNO3 mixing ratios were several parts per billion by volume (ppbv), yielding relationships with O3 and N2O consistent with those previously reported for NOy.

We present here the chemical composition of outflow from the Asian continent to the atmosphere over the western Pacific basin during the Pacific Exploratory Mission‐West (PEM‐West B) in February–March 1994. Comprehensive measurements of important tropospheric trace gases and aerosol particulate matter were performed from the NASA DC‐8 airborne laboratory. Backward 5 day isentropic trajectories were used to partition the outflow from two major source regions: continental north (>20°N) and continental south (<20°N). Air parcels that had not passed over continental areas for the previous 5 days were classified as originating from an aged marine source. The trajectories and the chemistry together indicated that there was extensive rapid outflow of air parcels at altitudes below 5 km, while aged marine air was rarely encountered and only at <20°N latitude. The outflow at low altitudes had enhancements in common industrial solvent vapors such as C2Cl4, CH3CCl3, and C6H6, intermixed with the combustion emission products C2H2, C2H6, CO, and NO. The mixing ratios of all species were up to tenfold greater in outflow from the continental north compared to the continental south source region, with 210Pb concentrations reaching 38 fCi (10−15 curies) per standard cubic meter. In the upper troposphere we again observed significant enhancements in combustion‐derived species in the 8–10 km altitude range, but water‐soluble trace gases and aerosol species were depleted. These observations suggest that ground level emissions were lofted to the upper troposphere by wet convective systems which stripped water‐soluble components from these air parcels. There were good correlations between C2H2 and CO and C2H6 (r2=0.70–0.97) in these air parcels and much weaker ones between C2H2 and H2O2 or CH3OOH (r2 ≈0.50). These correlations were the strongest in the continental north outflow where combustion inputs appeared to be recent (1–2 days old). Ozone and PAN showed general correlation in these same air parcels but not with the combustion products. It thus appears that several source inputs were intermixed in these upper tropospheric air masses, with possible contributions from European or Middle Eastern source regions. In aged marine air mixing ratios of O3 (≈20 parts per billion by volume) and PAN (≤10 parts per trillion by volume) were nearly identical at <2 km and 10–12 km altitudes due to extensive convective uplifting of marine boundary layer air over the equatorial Pacific even in wintertime. Comparison of the Pacific Exploratory Mission‐West A and PEM‐West B data sets shows significantly larger mixing ratios of SO2 and H2O2 during PEM‐West A. Emissions from eruption of Mount Pinatubo are a likely cause for the former, while suppressed photochemical activity in winter was probably responsible for the latter. This comparison also highlighted the twofold enhancement in C2H2, C2H6, and C3H8 in the continental north outflow during PEM‐West B. Although this could be due to reduced OH oxidation rates of these species in wintertime, we argue that increased source emissions are primarily responsible.

We report here measurements of the acidic gases nitric (HNO0, formic (HCOOH), and acetic (CH3COOH) over the western Pacific basin during the February-March 1994 Pacific Exploratory Mission-West (PEM-West B). These data were obtained aboard the NASA DC-8 research aircraft as it flew missions in the altitude range of 0.3 - 12.5 km over equatorial regions near Guam and then further westward encompassing the entire Pacific Rim arc. Aged marine air over the equatorial Pacific generally exhibited mixing ratios of acidic gases < 100 parts per trillion by volume (pptv). Near the Asian continent, discrete plumes encountered below 6 km altitude contained up to 8 parts per billion by volume (ppbv) HNO3 and 10 ppbv HCOOH and CH3COOH. Overall there was a general correlation between mixing ratios of acidic gases with those of CO, C2H2, and C2C14, indicative of emissions from combustion and industrial sources. The latitudinal distributions of HNO3 and CO showed that the largest mixing ratios were centered around 15 øN, while HCOOH, CH3COOH, and C2C14 peaked at 25 øN. The mixing ratios of HCOOH and CH3COOH were highly correlated (t a= 0.87) below 6 km altitude, with a slope (0.89) characteristic of the nongrowing season at midlatitudes in the northern hemisphere. Above 6 km akitude, HCOOH and CH3COOH were marginally correlated (t a= 0.50), and plumes well deftned by CO, C2H2, and C2C14 were depleted in acidic gases, most likely due to scavenging during vertical transport of air masses through convective cloud systems over the Asian continent. In stratospheric air masses, HNO3 mixing ratios were several parts per billion by volume (ppbv), yielding relationships with 03 and N20 consistent with those previously reported for NOy.

The NASA Global Tropospheric Experiment (GTE) Transport and Atmospheric Chemistry Near the Equator‐Atlantic (TRACE A) expedition was conducted September 21 through October 26, 1992, to investigate factors responsible for creating the seasonal South Atlantic tropospheric ozone maximum. During these flights, fine aerosol (0.1–3.0 μm) number densities were observed to be enhanced roughly tenfold over remote regions of the tropical South Atlantic and greater over adjacent continental areas, relative to northern hemisphere observations and to measurements recorded in the same area during the wet season. Chemical and meteorological analyses as well as visual observations indicate that the primary source of these enhancements was biomass burning occurring within grassland regions of north central Brazil and southeastern Africa. These fires exhibited fine aerosol (N) emission ratios relative to CO (dN/dCO) of 22.5 ± 9.7 and 23.6 ± 15.1 cm−3parts per billion by volume (ppbv)−1over Brazil and Africa, respectively. Convection coupled with counterclockwise flow around the South Atlantic subtropical anticyclone subsequently distributed these aerosols throughout the remote South Atlantic troposphere. We calculate that dilute smoke from biomass burning produced an average tenfold enhancement in optical depth over the continental regions as well as a 50% increase in this parameter over the middle South Atlantic Ocean; these changes correspond to an estimated net cooling of up to 25 W m−2and 2.4 W m−2during clear‐sky conditions over savannas and ocean respectively. Over the ocean our analyses suggest that modification of CCN concentrations within the persistent eastern Atlantic marine stratocumulus clouds by entrainment of subsiding haze layers could significantly increase cloud albedo resulting in an additional surface radiative cooling potentially greater in magnitude than that caused by direct extinction of solar radiation by the aerosol particles themselves.