State regulation of agro-industries in developing countries. Governance systems in the vegetable oil industry of Malaysia and Zimbabwe

Some observers of agro-industrial development in the Third World recognize the nation state as an important locus for mediation of conflicts between different social forces but fail to analyze the regulatory mechanisms and their effect on the dynamics of particular agro-industries. This paper proposes an analytical model to study agro-industrial regulation in a national framework. The purpose is to investigate the dynamics between changing forms of state regulation and particular industry governance system in the vegetable oil industry in Malaysia and Zimbabwe. State regulation and industry governance systems differ in a number of ways between the two countries. However, in each country there is a correspondence between the dominant form of state regulation and the industrial governance system. The study confronts some of the basic assumptions within the food regime approach and stress the need to incorporate the properties of the crops in the analysis of (agro-)industry governance systems.     

Sediment supply from landslide-dominated catchments: implications for basin-margin fans

The sediment flux from a mountainous catchment can be expressed as a function of a landslide rate constant κ which accounts for the vigour of hillslope erosion. Since the incising drainage network flushes all or a portion of the products of hillslope erosion to a range front where fan deposition takes place, a conservation of solid sediment volume allows the fan area and progradation distance to be calculated. These parameters are related primarily to the discharge of sediment from the catchment and to local tectonic subsidence.
A survey of modern alluvial fans in a wide range of climatic and tectonic settings shows that the effects of climate and bedrock lithology cannot be discriminated in the scatter of data of catchment area vs. fan area. However, by focusing on over 100 fans in the arid and semiarid zone of SW USA, the impact of tectonic subsidence rate is unambiguous. Although further quantitative data on local tectonic subsidence rates are urgently required, our preliminary analysis suggests considerable potential for reconstructing palaeocatchments where basin tectonic subsidence rates can be estimated. The progradation distances of fans from the northern and southern margins of the Middle Devonian Hornelen Basin of Norway, and the western and north-eastern margins of the Mio-Pliocene Ridge Basin, California, allow catchment sizes and denudation rates to be approximated. Although unique solution sets are not possible, an iteration of parameter values allows plausible parameter combinations to be calculated which shed light on the tectonic and sedimentary history of the proximal basin and upland source regions. Model results suggest significant asymmetry in basin subsidence rates, catchment slopes and transport mechanics between the two margins.     

On farsidedness of palaeomagnetic poles: Magnetic refraction,sediment compaction and dipole off-set

Summary Three possible ways to explain the Caenozoically observed farsidedness of paleomagnetic poles (apart from lithospheric plate movements) are discussed: magnetic refraction, sediment compaction and dipole off-set. The dipole off-set, being a possible geomagnetic field property, will be of opposite sign on opposite hemispheres, and hence will not tend to smoothe out by sectorial averaging. Sediment compaction shallows the inclination on both hemispheres, and hence will tend to smoothe out by sectorial averaging, provided that sediment properties, site latitude coverage and number of investigations are equal (fairly unlikely).Magnetic refraction causes systematic directional distortions of the remanent magnetization in rocks of moderate to high magnetic intensity (or apparent susceptibility k_app=k(1+Q)) such as in many volcanics, some metamorphics, as well as in baked clays and slags, etc. A detailed discussion of this effect is given: If the k_app of the material is above 0.001 emu/cm ³ (×4 SI), this effect is likely to cause a significant palaeomagnetic refraction error of the NRM (typically a TRM or a CRM) of the rock. An apparent susceptibility of this order of magnitude is quite common in volcanic rocks; e.g. for oceanic floor basalts the average of k_app is about 0.02 emu/cm ³ corresponding to systematic errors (flattening) of some 3° to 6° in the inclination of a horizontal flow, depending on the latitude.To improve paleomagnetic results in general, a simple refraction correction is therefore suggested to be applied in the case of common two-dimensional (i.e. flat, elongated) geological bodies such as dykes, sills, lava flows and baked clays. Numerical solutions are given for the horizontal case, while a graphical solution is given for the general two-dimensional case.Being of systematic types, the refraction error together with the sediment compaction effect may be responsible for a major part of the observed farsidedness of the Caenozoic palaeomagnetic pole positions, the apparent farsidedness not yet beeing masked by the scatter of pole positions produced by older individual lithospheric plate movements.Presented at 2nd conference on New Trends in Geomagnetism, Castle of Bechyn, Czechoslovakia, September 24–29, 1990.     

Martian volcanism: Additional observations and evidence for pyroclastic activity

Inspection of the Mariner 9 B-camera (resolution 100–200m) and A-camera (resolution 1–2km) photographs of Mars reveals numerous analogs of terrestrial and lunar volcanic features. In addition to the exceptionally large constructional features in the Tharsis region, many other large and small landforms present probably are related to endogenic processes.     

Spatially resolved methane band photometry of Jupiter: I. Absolute reflectivity and center-to-limb variations in the 6190-, 7250-, and 8900-Å bands

Spatially resolved measurements of Jupiter's absolute reflectivity in methane bands at 6190, 7250, and 8900 Å and nearby continuum regions are presented. The data were obtained with a 400 × 400 pixel charge-coupled device (CCD) at the 1.54-m Catalina telescope near Tucson, Arizona. Jupiter was imaged on the CCD through narrow-band interference filters. Photometric standard stars were also measured. Calibration data were obtained to remove instrumental effects. Uncertainty in the absolute reflectivity is ±8%. Uncertainty in the relative (across the disk) reflectivity is 1 or 2%. Uncertainty in the geomtry is ±1 pixel (0.22 arcsec) for centering and ±1% in scale. Intensity and scattering geometry are tabulated for points across 10 axisymmetric cloud bands and the Great Red Spot. Because of their high spatial, photometric, and time resolution, these data provide strong constraints on models of the Jovian cloud structure.     

Martian planetwide crater distributions: Implications for geologic history and surface processes

Population-density maps of craters in three size ranges (0.6 to 1.2 km, 4 to 10 km, and >20 km in diameter) were compiled for most of Mars from Mariner 9 imagery. These data provide: historical records of the eolian processes (0.6 to 1.2 km craters); stratigraphic, relative, and absolute timescales (4 to 10 km craters); and a history of the early postaccretional evolution of the uplands (> 20 km craters).Based on the distribution of large craters (>20 km diameters), Mars is divisible into two general classes of terrain, densely cratered and very lightly cratered—a division remarkably like the uplands-maria dichotomy of the moon. It is probable that this bimodal character in the density distribution of large craters arose from an abrupt transition in the impact flux rate from an early intense period associated with the tailing off of accretion to an extended quiescent epoch, not from a void in geological activity during much of Mars' history. Radio-isotope studies of Apollo lunar samples show that this transition occurred on the moon in a short time.The intermediate-sized craters (4 to 10 km diameter) and the small-sized craters (0.6 to 1.2 km diameter) appear to be genetically related. The smaller ones are apparently secondary impact craters generated by the former. Most of the craters in the larger of these two size classes appear fresh and uneroded, although many are partly buried by dust mantles. Poleward of the 40° parallels the small fresh craters are notably absent owing to these mantles. The density of small craters is highest in an irregular band centered at 20°S. This band coincides closely with (1) the zone of permanent low-albedo markings; (2) the “wind equator” (the latitude of zero net north or south transport at the surface); and (3) a band that includes a majority of the small dendritic channels. Situated in the southermost part of the equatorial unmantled terrain which extends from about 40°N to 40°S, this band is apparently devoid of even a thin mantle. Because this belt is also coincident with the latitutde of maximum solar insolation (periapsis occurs near summer solstice), we suggest that this band arises from the asymmetrical global wind patterns at the surface and that the band probably follows the latitude of maximum heating which migrates north and south from 25°N to 25°S within the unmantled terrain on a 50,000 year timescale.The population of intermediate-sized craters (4–10 km diameter) appears unaffected by the eolian mantles, at least within the ±45° latitudes. Hence the local density of these craters is probably a valid indicator of the relative age of surfaces generated during the period since the uplands were intensely bombarded and eroded. It now appears that the impact fluxes at Mars and the moon have been roughly the same over the last 4 b.y. because the oldest postaccretional, mare-like surfaces on Mars and the moon display about the same crater density. If so, the nearness of Mars to the asteroid belt has not generated a flux 10 to 25 times greater than the lunar flux. Whereas the lunar maria show a variation of about a factor of three in crater density from the oldest to the youngest major units, analogous surfaces on Mars show a variation between 30 and 50. This implies that periods of active eolian erosion, tectonic evolution, volcanic eruption, and possibly fluvial modification have been scattered throughout Martian history since the formation and degradation of the martian uplands and not confined to small, ancient or recent, epochs. These processes are surely active on the planet today.     

乌石凹陷含油气远景

乌石凹陷是北部湾盆地的一个以下第三系沉积为主的生油凹陷。主要生油层流沙港组泥页岩生油指标高、厚度大、分布面积广,具有丰富的油气源;在早第三纪已形成的四个局部构造带为有利的油气聚集场所。凹陷东部流沙港组存在高压异常,而凹陷西部存在流沙港组与涠洲组两套烃源岩。