Inactivation probability of heavy ion-irradiated Bacillus subtilis spores as a function of the radial distance to the particle's [correction of paricle's] trajectory.

The understanding of the radiobiological action of heavy ions requires the knowledge of the dependence of the inactivation probability on the distance between the particle's trajectory and the biological test organism (the impact parameter). Spores of Bacillus subtilis with a cytoplasmic core of about 0.22 micrometer cross section are suitable test objects for the study of this radial inactivation probability in its microscopic details. The spores are irradiated at low fluences of some 10(6) ions/cm2 with very heavy ions at different specific energies up to 10 MeV per atomic mass unit u while in fixed contact with visual nuclear track detectors. The methods are described by which the biological response of individual cells can be evaluated and the impact parameter be determined with an accuracy typically better than 0.2 micrometer. The results demonstrate that the common characteristics of inactivation, e.g., an effective range of inactivation extending to at least 3 micrometers, a nonmonotonic dependence of the inactivation probabilities on the radial distance, and the fact that the inactivation probability even for direct central hits on the cytoplasmic core is substantially below one, are nearly independent of the particle energy and type. The results are incompatible with the assumption that the radiobiological effectiveness can be attributed to the dose of secondary electrons as currently understood. They also demonstrate that the widely held notion of an "overkill" at low impact parameters does not apply for the spores even with the most densely ionizing ions.     

Red edge measurements for remotely sensing plant chlorophyll content

The feasibility of using the wavelength of the maximum slope of the red edge of leaf reflectance spectra (λ_re) as an indication of plant chlorophyll status was examined in the laboratory for single leaves of several species. λ_re for each sample was determined by derivative reflectance spectroscopy. A high positive correlation was found between λ_re and leaf chlorophyll content for all species, although there were some differences in the quantitative nature of the relationship for plants of different types. The position of the red edge was found to be unaffected by simulated change in ground cover, but multiple leaf layers produced a shift in its position. Appropriate spectral measurements and processing for obtaining useful information from the red edge are discussed, and the potential of the red edge in relation to other spectral measurements is considered.     

Influence of hypergravity on fish inner ear otoliths: I. Developmental growth profile.

Inner ear stones (otoliths) of larval cichlid fish Oreochromis mossambicus were marked with the calcium-tracer alizarin-complexone (AC) at 1 g earth gravity before and after a 3, 7, 14 or 21 days stay of the animals at hypergravity conditions (hg; 3 g, centrifuge). After the experiment, the otoliths' area between the two AC-labellings was measured with regard to size and asymmetry (size difference between the left and the right stones). Both utricular and saccular otoliths (lapilli and sagittae, respectively) continued growing in a linear way at hg, but growth was significantly slowed down as compared to parallely raised 1 g-control specimens. In case of bilateral asymmetry between the corresponding otoliths its formation in hg-animals became reduced as compared to the 1 g controls. The reduction of asymmetry was much more pronounced in the sagittae than in the lapilli. The latter result supports an earlier hypothesis, according to which especially a low sagittal asymmetry has a functional advantage. In general, the results strongly suggest that otolith growth is continuously regulated in dependence of the environmental gravity vector.     

Relay balloon

A relay balloon system for long-duration or large-area observations is described. The system consists of a balloon for scientific observations and a relay balloon for a data-relay terminal between a ground station and the balloon for observation. The system was successfully applied to the observation of electric-power fields (50 and 60 Hz) over the Pacific ocean. The maiximum distance between two balloons was about 1100 km and that between the Sanriku Balloon Center and the main balloon for the observation was about 1300 km.     

The status of space science and technology in developed countries — The european experience

Space research in Western Europe began in the form of independent national space programmes confined in the first instance to the use of sounding rockets. These early steps were soon supplemented by bilateral collaborative projects with the USA and USSR whose agencies provided the satellite launch vehicles that Europe lacked at that time.In 1962 as a result of an agreement between ten member states the European Space Research Organisation (ESRO) was established for the purpose of carrying out a programme of space science. ESRO was succeeded in 1974 by the European Space Agency (ESA) with a much broader range of activities covering both scientific research and the application of space technology together with the development of launch vehicles.At the present time the totality of space activities of the ESA member states is made up of national programmes and collaborative projects with other nations and agencies together with participation in the agreed ESA programme. Because of its essentially non-military character, its relatively modest level of funding and its multinational nature the European experience with ESA may provide some useful guidance in the development of space science and technology elsewhere in the world.     

Landsat analysis of the Yangjiatan tungsten district,Hunan Province,People's Republic of China

The Yangjiatan tungsten district at latitude 27°28′ N. and longitude 111°54′E. is located about 140 km southwest of the city of Changsha and 35 km northeast of the town of Shaoyang, southeast Hunan Province, People's Republic of China. The deposits, consisting largely of scheelite in veins (Wang, 1975), are contained in highly folded and faulted sedimentary rocks of Paleozoic, Mesozoic, and Cenozoic age intruded by granitic plutons that are circular in plan view. The major faults and folds trend in a northeasterly direction; whereas, the plutons are clustered in a more easterly trending band across the Landsat image.Landsat image E-2338-02202, acquired December 26, 1975, is number 470 in the “Landsat Image Atlas of the People's Republic of China” printed by the Publishing House of Geology in 1979. A computer-compatible tape of the image was analyzed and used as a demonstration project under a United Nations technical assistance program. Supervised classification of soils, rocks, and vegetation; band ratioing to detect limonite alteration; and edge enhancement were all conducted to demonstrate the flexibility and capability of interactive computer systems. Field evaluation of the results of this work will be conducted by colleagues of the Remote Sensing Center for Geology, Ministry of Geology, in China.     

Preliminary analysis of shuttle multispectral radiometer data for Southern Egypt

The Shuttle Multispectral Infrared Radiometer (SMIRR) is a spectroradiometer covering the region from 0.5 to 2.5 μm in 10 channels that acquired data from spots 100 m in diameter along the subspacecraft ground track. It was flown aboard the second flight of the space shuttle Columbia, November 12–14, 1981. Data collected during orbit 16 over southern Egypt show that carbonate rocks, kaolinite, and possibly montmorillonite can be identified by their SMIRR spectral signatures and limited knowledge of the lithologic units present. Detailed analysis of SMIRR data for this area indicates that calcite, kaolinite, and montmorillonite rocks give rise to absorption features that result in characteristic 10 channel spectra.     

Examination of a smallest CELSS (microcosm) through an individual-based model simulation.

Research of the effect of space environment on an ecosystem consisting of plants and animals is essential when they are to be positively used in space. Although there have been experiments on various organisms under space environment in the past, they mainly studied the effect of space environment on an individual organism or a single species. Microcosm is drawing attention as an experimental material of an ecosystem consisting of multiple species. The object in this research is to understand the nature of this network system called ecosystem. Thus, a mixed microorganism culturing system consisting of three types of microorganisms which form a minimum food chain system as a closed ecosystem (chlorella as the producer, bacteria as the decomposer, and rotifer as the consumer) was taken for the subject, on which to research the universal characteristics of ecosystems. From the results of experiments under the terrestrial environment, formation of colonies, which is an ecological structure, has been observed at its mature stage. The organisms form an optimal substance circulation system. Therefore, formation of colonies in simulation models is important. Many attempts have been made to create ecosystem models. For example, the Lotka-Volterra model forms a simultaneous equation with the differential equation expressing predator and prey relationship and many numerical calculations have been conducted on various ecosystems based on expanded L-V models. Conventionally, these top-down methods have been used. However, since this method only describes the average concentration of organisms that are distributed uniformly throughout the system and cannot express the spatial structure of the system, it was difficult to express ecosystem structures like colonies and density distributions. In actual ecosystems, there is heterogeneity in the number of individuals and in substance density, and this is thought to have great significance in ecosystems. Consequently, an individual-based model was used that applies rules to predator-prey relationship, suppression, production, self suppression, etc., of each species. It enabled the emergence of the overall system only by its local rules, and it was possible to reproduce colony generation. In addition, the transition and the ratio of populations for each species match well with experimental results.     

Mean zonal wind and temperature structure during the PMP-1 winter periods

Since Autumn of 1978, the National Meteorological Center of the United States National Weather Service has been archiving in a single, unique data set, global, daily synoptic analyses and computer gridded fields of geopotential height and temperature at 18 pressure levels from 1000 to 0.4 mb. The paper discusses the fields, with special emphasis on data and analysis procedures used for the stratospheric fields, along with estimates of uncertainties. Results are presented for the mean zonal wind and temperature patterns for each January of the four PMP-1 winters 1978/79 to 1981/82. The Preparatory MAP (Middle Atmosphere Program) Project for coordinated study of the behavior of the middle atmosphere is called PMP-1.