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Castrated male rats were treated parenterally with ovine prolactin during a primary infection with Nippostrongylus brasiliensis. Survival of the worms in the small intestine was prolonged, which suggested that prolactin inhibited rejection of the parasite.

Calicophoron calicophorum was recorded in domestic cattle from the East Kimberley district of Western Australia. No other species of paramphistomes were found. The significance ofC. calicophorum as a probable cause of poor productivity in beef cattle in tropical Northern Australia is discussed.

Mesenteric lymph node cells obtained from highly inbred donor rats (Lewis strain), resistant to Nippostrongylus brasiliensis infection, were syngeneically transferred by intravenous injection into previously uninfected recipients. The adoptively immunized recipients were then challenged with either 1500 or 3000 third stage N. brasiliensis larvae on the day of cell transfer. The degree of resistance transferred was assessed by monitoring daily faecal egg output, differential worm burdens on days 6 and 10 of infection and the number of eggs per uterus in gravid worms.

This Letter shows that transient changes in convection and precipitation patterns can significantly influence the electromagnetic energy transfer between the magnetosphere and the ionosphere. At the times of the transient events during the 10 January 1997 storm that was produced by a Coronal Mass Ejection (CME)-related magnetic cloud, the Sondrestrom incoherent scatter radar measured the local electrodynamic response of the high-latitude ionosphere. Important discrepancies between the net electrodynamic energy flux and the electromagnetic energy flux estimated for a stationary atmosphere suggest that the assumption of the ionosphere as a purely resistive load is often inadequate during these transient events as neutral winds cannot conform to the new orientation of the electric field and thus impact the load/generator characteristics of the ionosphere.

On 14 January 2001, the four Cluster spacecraft passed through the northern magnetospheric mantle in close conjunction to the EISCAT Svalbard Radar (ESR) and approached the post-noon dayside magnetopause over Green-land between 13:00 and 14:00 UT. During that interval, a sudden reorganisation of the high-latitude dayside convection pattern occurred after 13:20 UT, most likely caused by a direction change of the Solar wind magnetic field. The result was an eastward and poleward directed flow-channel, as monitored by the SuperDARN radar network and also by arrays of ground-based magnetometers in Canada, Greenland and Scandinavia. After an initial eastward and later poleward expansion of the flow-channel between 13:20 and 13:40 UT, the four Cluster spacecraft, and the field line footprints covered by the eastward looking scan cycle of the Söndre Strömfjord incoherent scatter radar were engulfed by cusp-like precipitation with transient magnetic and electric field signatures. In addition, the EISCAT Svalbard Radar detected strong transient effects of the convection reorganisation, a poleward moving precipitation, and a fast ion flow-channel in association with the auroral structures that suddenly formed to the west and north of the radar. From a detailed analysis of the coordinated Cluster and ground-based data, it was found that this extraordinary transient convection pattern, indeed, had moved the cusp precipitation from its former pre-noon position into the late post-noon sector, allowing for the first and quite unexpected encounter of the cusp by the Cluster spacecraft. Our findings illustrate the large amplitude of cusp dynamics even in response to moderate solar wind forcing. The global ground-based data proves to be an invaluable tool to monitor the dynamics and width of the affected magnetospheric regions.Key words. Magnetospheric cusp, ionosphere, reconnection, convection flow-channel, Cluster, ground-based observations

A method is presented for the characterization of zinc oxide photocopy papers. The tests include nondestructive physical examinations of weight, pH, and color under ultraviolet light. Chemical tests, consisting of thin-layer chromatographic examination of the sensitizing dyes and infrared spectrophotometry of the binder resins, are carried out on extractions of the photoconductive surface layer. A semiqualitative flow chart has been prepared that permits differentiation of most of the zinc oxide photocopy papers on the basis of the composite of characteristics of 50 papers supplied by eleven manufacturers.

We analyze simultaneous measurements by the incoherent scatter radars at Saint-Santin (45° latitude) and Chatanika (65° latitude) during a major magnetic storm in April 1978 to examine several disturbance mechanisms operating on the mid-latitude ionosphere during periods of strong magnetospheric and auroral activity. The first type of mechanism, the extension of magnetospheric convection electric fields to mid-latitudes, is illustrated by two large localized departures of the E×B plasma drifts over Saint-Santin that appeared in conjunction with the two storm negative phases. In both cases they were associated with large electric fields in the afternoon sector, within the eastward electrojet region, over Chatanika. The first event can be very clearly interpreted as a global short term enhancement of magnetospheric convection electric fields, since simultaneous plasma flux intensifications were identified over the polar cap, in the afternoon eastward electrojet, and at 45° latitude. The IMF and ring current signatures of these two events confirm our previous findings: large southward values of BƵ and large values of the rate of energy injection into the ring current system, are associated with the extension of magnetospheric convection electric fields to midlatitudes. In addition, a marked equatorward shift of the auroral oval was observed during both events. During the night of the first event, the mid-latitude drift perturbation magnitudes remained moderate (100 m/s) and did not seem to induce any significant ionospheric perturbation. The joint increase in ion and electron temperatures by 100 to 200° K above the quiet day reference level, which preserved the thermal equilibrium of the plasma, can be simply interpreted in terms of the storm-induced global heating of the thermospheric gas. Conversely, on the night of the second event, when drift magnitudes reached several hundreds of m/s, large-amplitude fluctuations in the F layer height and density, and very large increases (by more than 500° K) in the ion and electron temperatures were observed. Whereas collisional heating can account for a large part of the ion temperature increase, an additional energy source, heating preferentially the electron gas, is needed to explain the maintenance of the electron temperature 200° K above the ion temperature observed from the onset of the Dst decrease onward during that night. The identification of this source suffers from the lack of additional data, in particular photometric ones, in the Saint-Santin sector. However, the unusually large fields observed at Saint-Santin and the equatorward shift of the auroral zone observed at Chatanika in the early afternoon suggest that the plasmapause may have moved close to Saint-Santin and that the enhanced electron temperatures observed there might have been produced by a SAR arc.

Scientists in the fields of aeronomy, spate physics, and meteorology have used the Chatanika incoherent-scatter radar extensively over the last 11 years. During this past solar cycle, 11,718 hours of data were collected, resulting in substantial increases in knowledge of the high-latitude ionosphere and auroral processes. The 141 journal articles and 13 Ph.D. theses published since 1972 attest to the facility's productivity. On March 1, 1982, operations in Alaska ended so that the radar could be relocated to a higher invariant latitude (see Figure 1). The new location will be Sondre Stromfjord in Greenland, invariant latitude 75°. At this location, it will be the northernmost station of a longitudinal chain of incoherent-scatter radar facilities (Sondrestrom, Millstone Hill, Arecibo, and Jicamarca) stretching from the polar cap to the magnetic equator, and the incoherent-scatter technique, applied successfully in the auroral zone, will be available for polar cap/cusp research for the first time.

Several methods developed for mapping high-latitude plasma convection with a high-latitude HF radar are described, which utilize coherent backscatter from electron density irregularities at F-region altitudes to observe convective plasma motion. Several examples of two-dimensional convection-velocity maps are presented, showing instances of L-shell-aligned flow in the dusk sector, the reversal of convection near magnetic midnight, and counterstreaming in the dayside cleft.