One-hundred-ninety-four eligible and evaluable patients with histologically confirmed locally unresectable adenocarcinoma of the pancreas were randomly assigned to therapy with high-dose (6000 rads) radiation therapy alone, to moderate-dose (4000 rads) radiation + 5-fluorouracil (5-FU), and to high-dose radiation plus 5-FU. Median survival with radiation alone was only 51/2 months from date of diagnosis. Both 5-FU-containing treatment regimens produced a highly significant survival improvement when compared with radiation alone. Forty percent of patients treated with the combined regimens were still living at one year compared with 10% of patients treated with radiation only. Survival differences between 4000 rads plus 5-FU and 6000 rads plus 5-FU were not significant with an overall median survival of ten months. Significant prognostic variables, in addition to treatment, were pretreatment performance status and pretreatment CEA level.

Compatible segmented polynomial taper and volume functions were developed for yellow-poplar (Liriodendron tulipifera L.) from two ecoregions of West Virginia. The data were based on stem analysis of 26 trees from the Central Appalachian Broadleaf Forest province in northern West Virginia and 18 trees from the Eastern Broadleaf Forest province in west central West Virginia. Sample disks were extracted from 0.3, 0.6, 1.37, 1.8 m and then every 1.2 m to an approximate 7.6 cm top diameter outside bark. Sample trees ranged from 17.3 to 56.1 cm in diameter and from 18.8 to 38.5 m in total height. Model forms developed by Max and Burkhart [Max, T.A., Burkhart, H.E., 1976. Segmented polynomial regression applied to taper equations. For. Sci. 22, 283-289] and Clark et al. [Clark III, A., Souter, R.A., Schlaegel, B.E., 1991. Stem profile equations for southern tree species. USDA For. Serv. Res. Pap. SE-282] as well as two reduced forms of Clark et al. [Clark III, A., Souter, R.A., Schlaegel, B.E., 1991. Stem profile equations for southern tree species. USDA For. Serv. Res. Pap. SE-282] model were fitted to both inside and outside bark data. Outside bark taper prediction error for the proposed reduced model form using the fitted dataset had an average bias of 0.0153 cm and a standard error of the estimate of 1.2798 cm, based on the results from Central Appalachian Broadleaf Forest province. Volume prediction error for the same model and location had an average bias of À0.00002 m 3 and a standard error of the estimate of 0.0045 m 3 .Tests with an independent dataset from northern West Virginia showed the proposed reduced model form had the lowest overall outside bark prediction error as well as having the smallest error in five of the seven relative height classes tested. #

In some conifers, shoot geometry and needle morphology vary significantly in response to the light conditions under which they develop. We measured shoot length, silhouette area, total projected needle area, total needle weight and needle thickness on current shoots developed under a wide range of light conditions in a 36-year-old Abies amabilis (Dougl.) Forbes stand. Current light was quantified by evaluating percent openness from hemispherical photographs taken before the growing season. Unweighted total openness was correlated with shoot geometry and needle morphology better than any weighted indices tested. Needle thickness and leaf mass/area were both closely correlated with total openness (R(2) = 0.86 and 0.82, respectively). The most exposed needles were 2.5 times thicker and had 3-4 times more leaf mass/area than the most shaded needles. Total projected leaf area/shoot silhouette area was also correlated with openness (R(2) = 0.74) and was about twice as high in sun shoots as in shaded shoots. As a result of greater leaf mass/leaf area and greater leaf area/shoot silhouette area, a unit of intercepted light was dispersed over about 6 times as much leaf mass in a sun shoot as in a shade shoot, which presumably permits more efficient utilization of the intercepted light under high illumination with less energy wastage to light saturation. Moreover, leaf mass per unit of silhouette area was almost exactly proportional to canopy openness, as predicted by resource optimization theory if nitrogen concentration and photosynthetic capacity per unit mass are constant in new leaves. The close correlation of needle thickness and leaf mass/area with openness suggests that either parameter could be used as an index of the distribution of light or light-driven processes in an A. amabilis canopy.

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