Immunoglobulins from antiserum raised against chromatographically purified avian myeloblastosis virus (AMV) group-specific (gs) antigens were used in enzyme-linked immunosorbent assay (ELISA). Readily discernible color was produced with 2--3 ng of AMV protein in microplate wells coated with 4 micrograms of salt-precipitated immunoglobulins. When a biological assay, i.e., phenotypic mixing (PM), was the criterion for the infectious status of specimens, the ELISA consistently identified a greater percentage of virus-positive specimens than direct complement-fixation (DCF) tests. Over 95% concordance was obtained between the ELISA and PM bioassays when meconia and whole-blood samples were tested. Moreover, three DCF(-) egg albumens from one virus shedder hen were positive by the direct ELISA. Complete agreement was found between a biological assay for endogenous virus and the ELISA when blood and albumens from inbred chickens were tested. The ELISA is a rapid and convenient alternative to the DCF test for identifying infected chickens in eradication programs, because virus-rich sources such as meconia and blood that are unsuitable for DCF can be tested directly.

We made a prospective study of the incidence and natural history of algodystrophy and associated changes in bone mineral density in the ankles and feet of 60 consecutive patients who had suffered unilateral fractures of the tibial shaft. At bone union, 18 patients showed signs of algodystrophy. Its development was independent of the type of fracture management and of the severity of injury. Patients with algodystrophy lost significantly more bone mineral than did those without but the degree of this loss was independent of the type of treatment and of the time to fracture union.In most cases the symptoms resolved within six months of fracture union but in four patients they were still present at one year and two of these had not returned to work.

Considerable recent research on the draping of the interplanetary magnetic field (IMF) about the ionospheres of comets and Venus and about the Earth's magnetosphere, as well as draping of magnetospheric fields about Io's ionosphere and plasmoids, has indicated the fundamental and prevalent nature of this process. In this paper we consider the possibility of magnetic field draping about fast coronal mass ejections (CMEs) which propagate into the outer heliosphere through slower moving, quiescent solar wind. In particular, when this velocity difference is appreciably greater than the local Alfvén speed, draping should produce extended magnetotaillike configurations somewhat analogous to those observed behind Venus and comets. For CMEs, however, such tails would point sunward and form on scales comparable to these large ejecta. In the draped magnetotail regions sunward of fast CMEs in the outer heliosphere the IMF should be relatively radial, in contrast to the generally transverse orientation of the Parker spiral there. Low transverse flow velocities in the draped regions just upstream from fast CMEs suggest that swept‐up interplanetary magnetic flux is hung up on these large structures (∼1 AU in transverse dimension at 1 AU) for many days. We have searched for evidence of magnetic field draping about fast CMEs and the existence of large draped magnetotails in the outer heliosphere by examining the Pioneer 11 data set between 6.9 and 9.4 AU. Several events consistent with such structures have been found, and two are displayed in the study.

The magnetic fields measured by the Ulysses spacecraft are used to study solar wind turbulence in the fast solar wind from the south polar hole. The spacecraft was at about 46 deg south latitude and 3.9 AU. For a magnetic field with a Gaussian distribution the power spectrum (second‐order structure function) is sufficient to completely characterize the turbulence. However, the actual distribution is non‐Gaussian so that the effects of intermittency must be taken into account. The observed spectral exponents include effects of intermittency and cannot be directly compared with the standard second‐order spectral theories such as the Kolmogorov and Kraichnan theories. To permit a better comparison of the observations with the theoretical models, we study the structure characteristics of the data. We find the exponents of the second‐order structure functions (power spectra) and the higher‐order normalized structure functions for the components of the magnetic fields. We show that these sets of exponents can be approximately described by two basic numbers: the spectral exponent and the intermittency exponent. The intermittency exponent characterizes correlation properties of the energy cascade from large to small scales. Before comparing the observations to the theoretically expected values, a reduction must be made to the observed spectral exponent. The amount of the reduction depends on both the intermittency exponent and the model of the energy cascade assumed in the turbulence theory. We reduce the measured spectral indices according to a simple model for Alfvén turbulence that is described here. We then compare our reduced spectral indices with second‐order spectral theory. The reduced spectral indices for the period range of 1 min to about a half hour are remarkably constant and in good agreement with the value of 3/2. Thus our treatment is self‐consistent. Our tentative conclusion is that the high‐frequency turbulence appears to agree with the model of random‐phased Alfvén waves. This tentative conclusion must be tested by further theoretical and observational work.

Recent studies have suggested that the ambient interplanetary magnetic field (IMF) drapes about fast coronal mass ejections (CMEs) as they plow out through slower moving, quiescent solar wind. In this study we examine ISEE 3 plasma and magnetic field data in order to look for observational evidence of IMF draping ahead of fast CMEs. Since the upstream IMF is excluded from CMEs, the ambient field must drape about these ejecta and connect back to the Sun around their edges. For example, for a purely radial, inward directed IMF, this would mean that a CME which extends into the ecliptic plane while being directed northward of it should give rise to a southward Bz perturbation in the ecliptic plane ahead of the CME. While purely radial IMF configurations are rare, the radial component of the IMF should also give rise to such Bz perturbations. In reality, it is difficult to make an unambiguous identification of a CME's source region, and the draped field sampled along a spacecraft trajectory ahead of a CME can be very complicated, including contributions from a wide range of heliolatitudes as well as heliolongitudes. In spite of these complications we set out to test the usefulness of the draping scenario for predicting the Bz perturbations (and hence associated geomagnetic activity) ahead of fast CMEs which produce interplanetary shocks using ISEE 3 plasma and magnetic field data and Cane's (1985) list of shocks associated with interplanetary type II radio bursts. Of Cane's 45 events, there were 26 events which were suitable for testing the draping hypothesis. However, for only 17 of these 26 events was there a substantial change in the average Bz between the regions upstream from the shocks and between the shocks and CMEs. Of these 17 events the simpleminded radial component predictor developed in this study correctly predicts the direction of the Bz perturbations for 13 events (76%). While this result is certainly not conclusive, we consider it to be supportive of the draping scenario. In terms of using the draping model for real‐time geomagnetic activity predictions, however, the outlook is not nearly so good since nine of the 26 events had no substantial change in the average Bz and since there is no a priori way to tell how substantial draping effects will be for a given case.