This paper lists in chronological order all the nuclear detonations which have been announced by the six countries which have conducted nuclear detonations. The numbers of such detonations and the cumulative yield are underestimates for reasons presented and discussed. In a 30-yr span, beginning on 16 July 1945, and ending on 30 June 1975, some 801 nuclear detonations have been announced with a cumulative yield of about 325 Mt.Statistics for nuclear detonations are tabulated in a useful format and figures. International treaties and agreements which affected and continue to affect nuclear testing are discussed in relation to their effects.

Techniques that describe the use of covariance when heterogeneity of slopes exists are severely limited. Although a few procedures for model selection have been recommended, none, except the hierarchical approach, is straightforward and usable with present computer programs. The hierarchical subset selection procedure presented in this paper is based on the proposition that heterogeneity may be present only for certain terms in the model. After hierarchical selection, those terms which do not involve heterogeneity are interpreted as in the usual analysis for covariance. The interpretations of those terms which do involve heterogeneity are modified with respect to significance tests performed at various values of the covariate. The hierarchical subset selection method allows one to investigate heterogeneity of slopes in covariance models as functions of the classification variables present in the design.

Ethylene glycol dimethyl ether (EGdiME), diethylene glycol dimethyl ether (diEGdiME), triethylene glycol dimethyl ether (triEGdiME), diethylene glycol diethyl ether (diEGdiEE), ethylenethiourea (ETU), sodium selenite (SS), dimethyl phthalate (DMP), naphthalene (NAP), or p-nitrophenol (PNP) were administered by gavage for eight consecutive days to female CD-1 mice. Weight loss was insensitive as an index of sublethal adult toxicity and was inadequate for determining a maximum tolerated dose. LD50 values indicate that SS, NAP, and PNP were more toxic (8.4, 353.6, and 625.7 mg/kg, respectively) than the polyglycol ethers, ETU, and DMP (LD50 values ranged from 2525.8 to 6281.9 mg/kg). Each of the compounds was administered on d 7 through 14 to pregnant animals at a single dose estimated to be at or just below the threshold of adult lethality. In such a reproductive study, each of the compounds could be categorized on the basis of the pattern of maternal lethality and fetotoxicity which it produced. The number of dams with complete resorptions was significantly increased after administration of ETU, and no mice in the EGdiME-, diEGdiME-, or triEGdiME-treated groups delivered any viable offspring. Maternal lethality was significant in the EGdiME, triEGdiME, PNP, and NAP groups. There was a slight reduction in the average number of live pups per litter in the diEGdiEE- and PNP-treated groups and a significant reduction in the NAP group. The number dead per litter was increased with diEGdiEE. SS and DMP had no effect on maternal or fetal survival at the doses administered. Individual pup weight at d 1 postpartum was only significantly reduced by diEGdiEE, and no gross congenital abnormalities were detected in neonates from any treatment group. These results provide guidelines for the subsequent toxicity testing of these chemicals.

A negative exponential model with one independent variable, days or accumulated time, was examined for adequacy as a descriptive equation for aquatic leaf litter processing. The effect of adding a second independent variable, degree days or accumulated temperature, to the model was also examined. The two variable negative exponential model was shown to have two advantages over the single variable model. The expanded model provided an adequate fit of litter processing data for more cases than the single variable model. Also, the two variable model allowed determination of rate coefficients corresponding to each temperature level of the experiment rather than assuming a single, constant rate coefficient as with the one variable model. The trends of the temperature dependent rate coefficients were useful for examining processing differences between experiments for different sites and seasons.

Smelter workers were compared with employees at the mine, concentrator and refinery in an attempt to discover if the smelter environment has an effect on morbidity. The data for the study consisted of weekly indemnity insurance claim forms. It was found that the refinery, rather than the smelter, had the highest percent of employees submitting claims. Other major comparisons of morbidity among the four plants also showed the refinery to be highest, with the smelter closer to the mine and concentrator. This pattern was found to hold for respiratory disease classifications as well as overall morbidity levels.