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We present the development and characterization of a dedicated resonant soft x-ray scattering facility. Capable of operation over a wide energy range, the beamline and endstation are primarily used for scattering from soft matter systems around the carbon K-edge (∼285 eV). We describe the specialized design of the instrument and characteristics of the beamline. Operational characteristics of immediate interest to users such as polarization control, degree of higher harmonic spectral contamination, and detector noise are delineated. Of special interest is the development of a higher harmonic rejection system that improves the spectral purity of the x-ray beam. Special software and a user-friendly interface have been implemented to allow real-time data processing and preliminary data analysis simultaneous with data acquisition.

This paper describes a design study with the objective of optimizing spectral performance of an elliptical wiggler to be installed at the Lawrence Berkeley Laboratory Advanced Light Source (ALS). This device is to produce circularly polarized radiation in the energy range of 50 eV to 10 KeV. A figure of merit, which is a function of flux density and degree of circular polarization, is introduced as the objective function for optimization. An optimum set point for a particular photon energy is characterized by values of peak vertical field, horizontal deflection parameter, and vertical aperture. Optimum performance is evaluated for the nominal ALS operating energy of 1.5 GeV.

We have studied the magnetic domain structure of La0.7Sr0.3MnO3 (LSMO) nanoislands with dimensions on the order of 160 ~ 720 nm. Domain structures of (001)-oriented LSMO rectangular nanoislands exhibit single and multiple flux-closed domain states depending on aspect ratio. (110)-oriented rectangular nanoislands, with a strain-induced magnetically easy axis parallel to the long axis of the rectangle, exhibit single and two domain states depending on aspect ratio. (110) elongated hexagonal islands, with similar aspect ratios, uniformly exhibit single domain states due to the apparent suppression of domain nucleation at tapered edges. These results are consistent with object-oriented micromagnetic framework simulations of LSMO islands.

The demagnetization dynamics of the Heusler alloy Co(2)MnSi was studied using picosecond time-resolved x-ray magnetic circular dichroism. The sample was excited using femtosecond laser pulses. In contrast to the sub-picosecond demagnetization of the metal ferromagnet Ni, substantially slower demagnetization with a time constant of 3.5 ± 0.5 ps was measured. This could be explained by a spin-dependent band gap inhibiting the spin-flip scattering of hot electrons in Co(2)MnSi, which is predicted to be half-metallic. A universal demagnetization time constant was measured across a range of pump power levels.

First principles calculations within the tight binding linear muffin tin orbital method confirm the ferrimagnetic coupling between the Er 4f and Co 3d moments in the magnetically ordered phase and the change of sign of the Co 3d magnetization across the magnetostructural transition. Both the experimental x-ray magnetic circular dichroism measurements and theoretical results show that the influence of the rare-earth moment on the Co sp band is so strong that the polarization of the sp band does not follow that of the 3d band, but is determined by the Er sublattice magnetization, both in the magnetically ordered and paramagnetic states.

This paper provides current information on the epidemiology of the important mango disease, bacterial necrosis, caused by Pseudomonas syringae pv. syringae. It clarifies certain details contained within the first Australian report and provides further information on the symptoms and known epidemiology of the disease, in addition to potential management strategies.

The role of orbital magnetism in the laser-induced demagnetization of Fe/Gd multilayers was investigated using time-resolved X-ray magnetic circular dichroism at 2-ps time resolution given by an x-ray streak camera. An ultrafast transfer of angular momentum from the spin via the orbital momentum to the lattice was observed which was characterized by rapidly thermalizing spin and orbital momenta. Strong interlayer exchange coupling between Fe and Gd led to a simultaneous demagnetization of both layers.

Nursery-grown golden cane palms (Dypsis lutescens) in north-eastern Queensland exhibited angular, water-soaked and chlorotic haloed lesions typical of blight symptoms. Bacteria isolated from oozing preparations were identified as Burkholderia andropogonis through culture characteristics, microscopy, biochemical activity and 16S rRNA gene sequencing. A healthy golden cane palm was inoculated with the isolate and external symptoms were reproduced after approximately three months, whereupon the pathogen was reisolated.

An international collection of the sugarcane ratoon stunting disease pathogen, Leifsonia xyli subsp. xyli, was analysed to assess genetic diversity. DNA fingerprinting using BOX primers was performed on 105 isolates, comprising 65 Australian isolates and an additional 40 isolates from Indonesia (n=8), Japan (n=1), USA (n=3), Brazil (n=2), Mali (n=2), Zimbabwe (n=13), South Africa (n=9) and Reunion (n=2). Sixty-two of these isolates were also screened using ERIC primers. No variation was found among any of the isolates. The intergenic spacer (IGS) region of the ribosomal RNA genes from 54 isolates was screened for sequence variation using singlestranded conformational polymorphism (SSCP), but none was observed. Direct sequencing of the IGS from a subset of nine isolates, representing all of the countries sampled in this study, confirmed the results of the SSCP analysis. Likewise, no sequence variation was found in the 16S ribosomal RNA genes of the same subset. Four Colombian isolates from sugarcane, morphologically similar to L. xyli subsp. xyli, were putatively shown to be an undescribed Agrococcus species of unknown pathogenicity. The lack of genetic variation among L. xyli subsp. xyli isolates, independent of time of sampling, cultivar of isolation, or country of origin, suggests the worldwide spread of a single pathogenic clone, and further suggests that sugarcane cultivars resistant to ratoon stunting disease in one area should retain this property in other regions.

Twelve years ago our understanding of ratoon stunting disease (RSD) was confined almost exclusively to diagnosis of the disease and control via farm hygiene, with little understanding of the biology of the interaction between the causal agent (Leifsonia xyli subsp. xyli) and the host plant sugarcane (Saccharum spp. hybrids). Since then, research has focused on developing the molecular tools to dissect L. xyli subsp. xyli, so that better control strategies can be developed to prevent losses from RSD. Within this review, we give a brief overview of the progression in research on L. xyli subsp. xyli and highlight future challenges. After a brief historical background on RSD, we discuss the development of molecular tools such as transformation and transposon mutagenesis and discuss the apparent lack of genetic diversity within the L. xyli subsp. xyli world population. We go on to discuss the sequencing of the genome of L. xyli subsp. xyli, describe the key findings and suggest some future research based on known deficiencies that will capitalise on this tremendous knowledge base to which we now have access.

Circular polarization insertion devices and beamlines at the Advanced Light Source are described. The facility will consist of multiple undulators feeding two independent beamlines, one optimized for microscopy and the other for spectroscopy. The energy range of the beamlines will go from below 100 eV to 1800 eV, enabling studies of the magnetically important L2,3 edges of transition metals and the M4,5 edges of rare earths.

Bending magnet beamline 9.3.2 at the Advanced Light Source (ALS) was designed for high resolution spectroscopy with capability for delivering circularly polarized light in the soft X-ray energy region using three gratings. The monochromator is a fixed included angle spherical grating monochromator (SGM) and was originally used at SSRL as a prototype for later insertion device based monochromators for the ALS, For operation at the ALS, the toroidal pre-mirror used at SSRL was replaced by a horizontally focusing and a vertically focusing mirrors in the Kirkpatrick-Baez configuration. Circularly polarized radiation is obtained by inserting a water-cooled movable aperture in front of the vertically focusing mirror to allow selecting the beam either above or below the horizontal plane. To maintain a stable beam intensity through the entrance slit, the photocurrent signals from the upper and lower jaws of the entrance slit are utilized to set a feedback loop with the vertically deflecting mirror piezoelectric drive. The beamline end station has a movable platform that accommodates two experimental chambers enabling the synchrotron radiation to be directed to either one of the two experimental chambers without breaking the vacuum.

The latosols, or ‘red and yellow’ soils of the tropics, encompass a wide range of properties and fertility. The poorer types occupy large areas both in the rain forest and in savanna climatic zones. The various systems of shifting cultivation traditionally practised are now inadequate with regard to increasing population densities, and management should be based on fertilizer application at moderate levels together with methods of maintaining organic matter and hence soil structure.

ICRAF's main contributions to research related to soils have been a symposium, Soils Research in Agroforestry; a review of soil productivity aspects of agroforestry; a further review of the potential of agroforestry for soil conservation, covering both erosion control and maintenance of fertility; the construction of a computerized model to predict soil changes under agroforestry systems; and a handbook of practical methods of agroforestry for soil and water conservation in dryland Africa. In research on land evaluation, an environmental data base has been established, leading to a capacity to obtain information, for environmental conditions similar to those of a given site or area, on publications, multipurpose trees, crops, existing agroforestry systems and current experimental work. Land evaluation for agroforestry cannot be achieved merely by synthesis of methods from agriculture and forestry, but will require more data on the performance of agroforestry land utilization types. Recognition of problems of environmental degradation has become an integral part of planning for agroforestry research. By means of a partial synthesis between land evaluation and diagnosis and design, a procedure of site selection for agroforestry research and development has been established.

Summary The volume of sediment deposited in Strines Reservoir, Yorkshire, over a period of 87 years indicates an annual loss of material from the area draining into it equivalent to a layer of 0.04 in. thickness from the whole of the valleys, or 0.12 in. thickness if it is assumed that the material is derived very largely from the steeper slopes.

The experimental program at the Advanced Light Source to produce and characterize circularly polarized x-rays is described. A number of beamlines are either operating or under construction which produce circularly polarized light. Bend magnets, multilayer phase retarders, and insertion devices which directly produce circularly polarized radiation are described. These beamlines will have capabilities for both microscopy and high resolution spectroscopy. Measurements of the linear and circular polarization of these beamlines are also described.

Stmzmary.48 black teenagers living in the Douglas neighborhood of Chi- cago were given both the Black Intelligence Test of Cultural Homogeneity and the Shipley-Institute of Living Scale. Lower-class black subjects (housing project residents) scored below middle-class black subjects (high-rise apartment resi- dents) on the vocabulary and abstract reasoning subtests of the Shipley but not on the Black Intelligence Test of Cultural Homogeneity. Scores on the latter increased directly with age, and females scored higher than males. When age was controlled for middle-class subjects Black Intelligence Test of Cultural Homogeneity scores were negatively related to vocabulary and when sex was controlled with lower-class subjects, scores were positively related to vocabulary. Abstract reasoning was negatively related to Black Intelligence Test of Cultural Homogeneity scores when age was controlled for all subjects. The Black Intelligence Test of Cultural Homogeneity has discriminated black and white St. Louis teenagers' and black and white Portland police applicants (Matarazzo & Wiens. 1377). This study compared scores of black Chicago teenagers of different socio- economic levels, based on place of residency, on the Black Intelligence Test of Cultural Homogeneity. The 22 male and 26 female subjects (16 to 18 yr. old) were also given the vocabulary and abstract thinking subtests of the Shipley-Institute of Living Scale. Testing was done in small groups in the Douglas neighborhood and subjects were told only that they would be taking part in a community survey. Residents of the public housing project (lower socio-economic level) were tested in a youth activity center in the project and residents of high-rise apartments (middle class) were tested in a church near the apartments. The mean raw Black Intelligence Test of Cultural Homogeneity score of 57.31 (SD = 17.58) was well below the mean of 84.89 reported by Matarazzo and Wiens ( 1977) and the 87 reported by Williams.' The multiple regression coefficient of age, sex, socio- economic level, vocabulary and abstract reasoning on test scores was significant; R = ,569 (F = 4.02, p < .005). However, age (F = 10.83, p < ,002) which was positively related to Black Intelligence Test of Cultural Homogeneity scores and sex (F = 7.43, p < .009), with females scoring higher than males, accounted for 8S% of the predicted variance of the scores. Socio-economic differences were large for vocabulaty (F = 36.96, Af = 1/36, p < ,001). abstract reasoning (I; = 12.89, df = 1/36, p < .001), and a full scale Shipley (F = 28.86, df = 1/36, p < ,001) but there were no socio-economic differences on the Black Intelligence Test of Cultural Homogeneity. However, test scores correlate with Shipley scores in opposite directions within socio-economic levels when 'Request reprints from J. J. Rearden, Eastern Illinois University, Charleston, IL 61920. For tabled data in Document NAPS-03505 remit to Microfiche Publications, 440 Park Avenue South, New York, N. Y. 10016, $3.00 for fiche or $7.75 for photocopy. 'R. L. Williams. Black Intelligence Test for Cultural Homogeneity: manual of directions. (Available. 1975, from Robert L. Williams, Williams and Associates, Inc., 6374 Delmar Boulevard, St. Louis, Missouri 63130)

A fresh look at available estimates of the rates of erosion suggests that landforms have taken longer to evolve than has been thought.

The purpose of this document is to record developments in certain aspects of geomorphology which were influenced by contributions of the late David L Linton. It consists of fifteen essays, the titles of some of which are as follows:- Geomorphology in the United Kingdom since the First World War - Brown, EH and Waters, RS; Granite Landforms: a Review of Some Recurrent Problems of Interpretation - Thomas, MF; the Geomorphological Importance of Jointing in the Dartmoor Granite - Gerrard, JW; Granite Tors in the Sudeten Mountains - Jahn, A; the rate of slope Retreat - Young, A; a Parametric Approach to Landform Regions - Speight, JG; Detailed Geomorphological Mapping and Land Evaluation in Highland Scotland - Crofts, RS. /TRRL/

Agroforestry refers to land use systems in which trees are grown in association with crops and/or pasture and livestock, and in which there is both an economic and an ecological interaction between the trees and other components. It is based on multipurpose trees, those which make more than one contribution to the productive and service functions of land use systems. Interactions take place at the tree/crop or tree/pas- ture interface, involving shade, organic matter, nutrients, microclimate, soil moisture and conservation. There are over twenty agroforestry prac- tices, arrangements of components in space and time, and many hundreds of agroforestry systems, traditional and modern. A major function of agroforestry is in helping to solve land use problems: problems of the farmer and of the land. Land use planning for agroforestry makes use of the methods of land evaluation and of diagnosis and design. Although

Over the past 20 years there has been a growing recognition that land develop? m nt plans in the tropics should be ased on surveys of the physical environ? ment, or natural resource surveys. The immediate aims of these surveys have been of a local nature: to enable development to make the optimum use of resources and to avoid environmental hazards, particularly those consequent on the disturbance of the ecological balance. But the maps and monographs produced for these applied pur? poses have also contributed substantially to knowledge of the nature of the physical environment of the tropics. Each group of natural scientists concerned with resource surveys realized the need to provide a framework to which detailed local surveys could be related. Nowhere was this more necessary than in Africa, where scientists from Britain, France and Belgium have tended to work independently of each other, establishing different concepts and methods, particularly with regard to environmental classification systems. Inter? national coordinating organizations were established, and under their auspices a series of maps of environmental factors for the African continent have been produced. These include two vegetation maps of a scale of i: 10 million, one showing physiognomic vegetation types (Keay, 1959) and the other floristically-based grassland types (Rattray, 1960; previously reviewed in Geogr. J. 128 (1962) 527); two climatie atlases, with the climatie elements mapped at scales of 1:5 million to 1:30 million (Jackson, 1961; Thompson, 1965, previously reviewed in Geogr. J. 132 (1966) 291-2); and two maps at 1:5 million, which it is proposed to discuss here, of geology and of soils (Furon and Lombard, 1964; D'Hoore, 1964). It has now become possible to abstract a range of environmental information, classified on a uniform basis, for any selected location in Africa (south of the Tropic of Cancer). It would be naive to expect a high level of accuracy for these maps, large parts of which are based on reconnaissance surveys at small scales or interpolations between scattered data; but at the least they summarize the views of the appropriate specialists, with all available information at their disposal. The small-scale maps of African geology, climate, vegetation and soils carried by atlases may now be re-drawn on a comparatively well-established foundation. The maps of geology and soils are both cartographically well-produced. The Geological map covers the continent in eight non-overlapping sheets; a ninth gives the full legend, and the whole can be assembled as a display map some six feet square. Parallels and meridians are shown at 50 intervals, with i? intersections marked by small crosses; the latter in no way obscure the geological detail, yet permit any chosen area or point to be located rapidly. Geological information is shown by colour-shading and symbols, although there are some discrepancies between the combinations of these ap? pearing on the map and in the legend. The Soil map comprises seven sheets, with parallels and meridians shown at 20 intervals. A substantial overlap between sheets renders it more convenient for reference. On both maps the relevant parts of the legends are shown on each sheet, but in the case of soils the full legend is found only in the explanatory monograph. The Geological map is accompanied by a list of source maps for each territory, the scales of which provide some indication of the intensity of survey and hence the accuracy to be expected. For the Soil map there is only a list of contributors, many of whom who are no longer working in their respective countries. Courtesy and politics forbid the inclusion of an inset map showing relative accuracy on international compilations of this kind. The nature of the distribution pattern of soils is such that profiles with widely different properties, separated at a high level in any systematic classification, occur within small areas. Consequently in mapping on a continental scale, composite units must be employed. The 63 soil types contained in the classification scheme are termed ^ Dr. Anthony Young is Lecturer in Geography at the University of Sussex, and has worked as Soil Surveyor in Malawi. Earlier this year he was geomorphologist on the Royal Society/R.G.S. Mato Grosso expedition.