Document xEeX0ODyr3491Yqgpjd8yknQ

I'll \ vs r munologically. In addition to RSVa, nooinfectioui forms of mouse sarcoma* leukemia virus have been reported to have very luw levels of DNA polym erase </i). None of the Infectious forms has been found deficient in this enzyme. H. Hanafusa Public Health Research Institute of the City of New York, New York 10016 D. Baltimore, D. Smoler Department of Biology, Massachusetts Institute of Technology, Cambridge 02139 K. F. Watson, A. Yaniv S. Seieoblman Institute of Cancer Research, Department of Human Genetics and Development, Columbia University College of Physicians and Surgeons, New York 10032 I. H. Hanafuta end T. Hanafuit, Virology S4, )0 (1461). t. T. llwiafukB, H. Hanafusa. T. Miyamoto. Pror. Sot. Atod. Stl. U S A. ST, 1797 (1970). 1. H. Hanafusa and T. Hanafusa, *Urotot? S3. 119 (1971). 4- W. 44, S. Robinsoa 497 (1971). and H. L. Robinson. Ibid. 9. D. Biliimoi* and D. Smoler, free. Not. Acad. Set. UJ.A. SO, 1907 (1971V S. S. Spiefelman, A. Bumjr, M. R. Dai, t. Keyear, J. Schism, M. Travnictk, K. Watton, 77. Nalor* SSI, 430 (1970), Abbreviations; Ply(A), polyatfenylata: poly(C), pelyeyildylaie; poly(dT), polydaonytltymidy- lata; poly(dG), polydeoaysuanylatc: dTMP. dcoiythymidine monophosphate: dTTP, dc- oxyihymidlne trlpboiphatt; dATP. Utoxyadenoilnt trl|hnplwwi tfOTP, dnirfuneum tri* phosphate; dCTP. deosycytldloe trlpboiphatt; IgO, Immunoglobulin G. J;S. L. A. Loeb. /. Blot. Cfitm. 144, It 72 (1949). 9. K. P. Watton, R. C. Npwlntki. A. Yaniv, S. Splegelman, J, Vtrot., In preu. 10. R. C. NowiniU. K. F. Watton. A. Yaniv, ' S. Spieitlman, In preparation. "11. D. L. Kaelan, K. F. Wataoa, Spletelman, BlocHIm. PlopMys. A. Buray, S. Acta S44, 369 0971). tIS2-. A. Welubaeh, A. BoMea, R. Muller, H. Hanafusa, T. Hanafuia, /. Virot., la pran. 13. F. T. PeeMat, D. K. Haapala, A. F. Gaidar, J144. Ibid. 9. 4IS (1972). S. Splegelman, A. Bumy, M. R. Dai, J. Keydar, 3. Scblom, M. Travnictk, K. Watton. Notary SI7, 9SI (1970). 13. We thank Dri. A. J. Laaglob and D. and J. W. Beard (or aupplying avian myeloblastosis vinai. We alto thank Dr. R. NowIntU lor astiatenca in preparing antiierura against purified AMV DNA polymerase, and Dr. T. Hanafusa for various viruiei. Supported by NCI grant! CA-OS747 and CA-02332 from the contract* from the Spaetal Virus Caaecr Ptogram of NCI (including 7(h2049 to the Institute of Cancer Research). 6 July 1972; nvised 12 August 1973 Polychlorinated Biphenyl Residues: Accumulation tn Cayuga Lake Trout with Age of their age, length, and weight. The correlation coefficient for PCB co> centration as a function of age was 0.86 and was highly significant. The corre lation confidents relating PCB concen tration with length and weight for fish 2 years and older were 0.83 and 0.80, respectively. The weights and lengths of the year-old trout were not recorded. The relation between the cone, ntration of PCB's in the lake trout and their age is shown in Fig. I; the curve rep resents the best fit of the data and has the equation: PCB = 1.0311* "** where a is age. Figure 2 shows gas chromatograms of PCB's in a 12-year- old lake trout and of Aroclcr 1254 standard (a mixture of chlorinated bi phenyls containing 54 percent chlorine) to illustrate the similar peak retention times. Tht_re_latjve eak heights of in dividual PCB isomers in the chromatogramUid not vary with age of the BsK This would indicate that there is no selective metabolism or slorage ot spe- Tine pcb isomers as the mature. Combined gas chromatography-mass spectrometry was used to verify the presence of the various PCB isomers in a 12-year-old lake trout (PCB's. 26.2 Abstract. The concentration of polychlorinated biphenyls was shown to pro gressively increase with maturity in a series of lake trout. The presence of these compounds hoi determined by column chromatographic isolation, specific de~ reefer gas chromatography and mass spectrometry. The relation between fish age and the concentration of polychlorinated biphenyls was highly significant. Residues of polychlorinated biphenyls (PCB's) have been reported in Ash (/), and general environmental contamina tion by these compounds has been re viewed (2). The concentration of DDT residues in a scries of lake trout from Cayuga Lake in Ithaca, New York, was found to be proportional to their age (3). Since PCB's arc similarly stable, fat-soluble compounds, analysis for them was performed on the same series of fish. The fish were netted in October 1970. Their ages were accurately known, because the fish are annually stocked hi yearlings and distinctly marked as to year class. Without evisceration, each fish was mechanically chopped, ground, and thorough))' mixed. Fish samples (5 g) were dried and extracted with hexane in a Soxhlet apparatus for 3 hours. The hexane extracts were con centrated, and PCB's were separated from DDT residues and other constitu ents by adaptations of the methods (4) involving sulfuric acid partitioning and column chromatography on silica gel. Final analysis was made by electron af finity gas chromatography with a col umn 30 cm long, consisting of 10 percent DC-200 on 100- to 120-mesh Gas-Chrom Q and operated at 185C. The concentration was estimated by the method of Risebrough (5), in which the response of each PCB isomer is taken as equal to that of the correspond ing weight of p.p'-dichlorodiphenyldichioroethylene (p.p'-DDE). This meth od was sensitive to about 0.25 part per million (ppm) of PCB's in the fish. Analysis of PCB's in five portions of the same fish were 6.4, 6.0, 5.6, 5.6, and 5.3 ppm. The standard deviation for these analyses is 0.427, Table 1 lists the concentrations of PCB's in the lake trout as a function Table I. Residues of PCB's in Cavugt Lake trout as a function of maturity; J. juvenile. Age (yean) Sex tJ 1J 11 1J 2J 2J 2S 3J 3J 3J 4J 4J 4J 3M 6M 6M 6P 7M 7M 7 gF 8M 8F 9F 11 M 12 M 12 M 12 F Length (cm) 27.7 28.7 33.5 44.3 44.3 41.t 33.8 30.3 33.1 61.0 63.3 66.4 68.3 63.3 68.9 39.7 75.2 71.4 69.0 71.2 80.3 71.6 75.3 70.6 Weight PCB (1) (ppm) 181 226 407 813 725 770 1310 1160 1339 2030 2440 2830 2310 2260 3300 1990 3390 2805 3300 3390 4200 2333 3120 3440 0.6 1.6 0.5 1.2 2.0 1.3 2.3 2.2 2.4 1.2 3.5 4.1 5.1 5.7 3.4 97 8.6 4.0 53 10.3 17.5 13.4 4.5 30.4 12.4 13.4 26.2 7.4 39smrrMBCR 1972 MOWS 082450 1191 t fish may be due to greater differences ariiwuii mi New among foraging, metabolic, and excre tory capabilities of these older fish. Carl A. Bache Pesticide Residue Laboratory, Cornell University, Ithaca, New York 14850 1. J- H. Kocman, M. C. Ten Noam Dt Stunt, R. H. DeVet, Nairn SSI. 112ft (1969); 1 /entta. A. O. Joturalf. M. Oluon. O. Otter* liotf, ibid. 224. 247 0969); V. Zitko, Butt Environ. Canimm. Toxical. 4. 464 (1971). 2. D. a. PtakAU w X. L. Linear. JfoScfenct SS, 951 (1470); A. L. Hanmontt, Science i?J, |JJ James W. Serum 3. W. D. Ycninp, w. H. CHitnmaan, D. i. Department of Chemistry, Litk. Environ. Set. Ttehnol. 4, 431 (1972). i Cornell University William D. Youngs Department of Natural Resources, 4. D. L. Orani, W. E. J. Phillips, D. C. ViUeiwuve, Bull. Environ. Contain. Toxicol. 6, in (1971); D. Snyder awl R. P.-iaait, ibid., p, 5. R. W. Rlwbroufh, in Chemical Fallow. M. Cornell University W. MlUer and 0. 0. er. Eds. (Ttemw. i Donald J. Lisk Sprlnvflcld, III. 1949), pp. S-23. 4. We thank O. A. Marlin for allo*ui| me i Pesticide Residue Laboratory, Cornell University the man spectrometer. 30 Sum 1972 m f Atmospheric Carbon Dioxide: Its Role in Maintaining Phytoplankton Standing Crops Fig. 1. The concentration of PCB'i in Cayuga Lake trout as a function of age. ppm). The mass spectra obtained from both a Perkin-EImer 270 and a Finnigaa 1015 quadripole gas chromato graph-mass spectrometer were essen tially identical with the mass spectra of the corresponding isomers of Aroclor 1254 standard. There are many sources ol PCB's in the environment, and it is not known whit combination of these leads to con tamination of Cayuga lake trout.,JJhe_ increase in PCB concentration with trout"EWis the Same .tfchd holedJqt DD11 residues in this scries of fish. The laTjJF'vanafion in PCB concentrations among individual II- or 12-year-o!d Fig. 2. Cas chromatograms of a 12-yearold Cayuga Lake trout (injected sample represents 0.12 mg of fish) and 1 ng of Aroclor 1254 standard. Abstract. The rate of invasion of carbon dioxide into an artificially eutrophie Canadian Shield Sake with insufficient internal sources of carbon was determined by two methods; measuring the carbon: nitrogen: phosphorus ratios of seston after weekly additions of nitrogen and phosphorus, and measuring the loss of radon-222 tracer from the rpilimnion. Both methods gave an invasion rate of about 0.2 gram of carbon per square meter per day. The results demonstrate that invasion of atmospheric carbon dioxide may be sufficient to permit eutrophi cation of any body of water receiving an adequate supply of phosphorus and ni trogen. The atmosphere is frequently con sidered to be an insignificant source of CO- for phytoplankton production (/). Yet, by adding phosphate and nitrate we have been able to increase by almost two orders of magnitude the standing crop of phytoplankton in a small Cana dian Shield lake which has extremely low concentrations of natural dissolved inorganic carbon (less than 0.6 mg/ liter in the cpilimnion in midsummer). The lake appears to have obtained the carbon necessary to produce the algal bloom from the atmosphere (2, 5). We report here measurements of the inva sion rale of atmospheric COj into the waters of this experimentally enriched lake. The results were obtained between 4 and 18 August 1970. Lake 227, a small oiigotrophic lake in the experimental lakes area of the Fisheries Research Board near Kenora, Ontario, was enriched with 0.34 g of phosphorus (as Na-HPO,) and 5.0 g of nitrogen (as NaNOs) per square meter per year in 1969, and 0.48 g of phos phorus (as HjPO*) and 7.2 g of nitro gen (as NaNOs) per square meter per year in 1970. The chemical additions were made in 17 weekly increments in 1969 and 21 weekly increments in 1970. The midsummer phytoplankton standing crop, as measured by chloro phyll a concentrations, increased from l to 3 fig/liter in 1968 (before fertiliza tion) to 50 to 100 fig/liter after the additions. The uptake of C03 by this phytoplankton caused an increase in the pH of the euphotic zone from normal values of 6 to 7 to values ranging from 9.5 to 10.2 during summer, so that very little of the dissolved inorganic car bon was present as gaseous CO- (2. 5). The concentration of dissolved inorgan ic carbon (ICO- = C02 + HC05- + C032~), however, did not change great ly after fertilization. The midsummer concentrations of total CO- in the epilimnion ranged from 20 to 50 fimole/liter (0.24 to 0.60 mg/liter). As a result of the high pH and low con centration of CO.:, the partial pressure of CO- in epilimneiic waters (calculated from the pH. total CO- concentration, and temperature) was far below that of the atmosphere (Fig. I); this created a pronounced concentration gradient from the atmosphere into ihe lake. It is impossible to calculate the magnitude of CO- exchange between the atmosphere and the water from the difference in partial pressures alone. 1192 SCIFNCE. VOL. 177 HONS 082451