Marginal Sectors Research Articles

Channel migration patterns and related sequences in some alluvial fan systems

The pendular displacement of a channel system, consisting of an area of higher channel density (trunk channel zone) on both sides of which channel density progressively decreases (secondary channel zone), can, under favourable subsidence conditions, lead to the development of alluvial fans. Characteristic sequences are found in these fans, depending on their position in the sedimentary body. A marginal position in the fan is thus recognized by the superposition of fining and thinning upwards (FTU) cycles, the upper part of which is made up of important thicknesses of overbank fines, all the backsets of bars dipping in the same direction (towards the centre of the cone). On the other hand, a central position is characterized by a higher number of FTU cycles, which are incomplete due to erosion of the upper parts (corresponding to the higher concentration of overbank fines), and the backsets in each cycle dip alternately in opposite directions. The displacement of the channel system in a constant direction may be caused by the preferential accumulation of bars on one of the banks of the channel. The change in migratory direction giving rise to the pendular movement is caused by the trunk channel reaching the basin margin or the sedimentation area of an adjoining fan. Palaeogeographic reconstructions of fans using this technique contribute to the analysis of ancient basins: small-radius fans with a high sweep angle (A S) are characteristic of basin margins subjected to a low sediment supply/subsidence ratio (S S /S B), whereas large-radius fans with a low A S characterize periods with a high S S /S B ratio on the basin margin. This model can be applied in economic geology studies, as the location of an ancient cone permits delimitation of the axial strip (with a higher proportion of coarse, highly porous, channelled facies) and the marginal sectors (where thick layers of less porous overbank fines are intercalated). We here present the example of the alluvial fans in the Guadix Fm. (Betic Cordillera, Spain), which lie on a basin margin (ESE) where the S S /S B ratio increased progressively throughout the Lower Pliocene. The detailed analysis of palaeocurrents on the basis of different criteria throughout the Arroyo de Gor section helps to locate more precisely and confirm the palaeogeographical distribution of the Pliocene cone, as deduced from sequential analysis.

L'industrie du plasma

The Commercial Blood Plasma Industry The commercial blood plasma industry in the United States obtains its raw « source plasma » from economically marginal sectors of the population. This paper focuses on the connections between the US plasma industry and the homeless, who comprise one major sector of the plasma « donor » population. The broader homeless economy provides few dependable economic opportunities and over time on the streets many homeless individuals come to rely on selling plasma. The regular selling of plasma may damage the health of long-term homeless « donors ». The homeless are also subjected to stigmatizing interactions in the plasma centers where they donate. We conclude by discussing the public health and moral dilemmas resulting from the commercial exploitation of the bodies of the most destitute members of American society.

La fonction sociale et politique des hétérodoxies religieuses en Amérique latine

Pentecostalism and other new religious movements have acquired an increasing social and political visibility during the 1980s. This corresponds to a restructuring of the religious field and a re-elaboration of the popular religion of subordinate and marginal social sectors by means of a symbolic do-it-yourselfism. Far from being faced with a movement of protestant religious reform as Martin and Stoll suggest in their recent works, we are witnessing a re-enchantment of the world in the sense of traditional, corporatist and authoritarian practices and values. The “clientelist” use of heterdox religious infrastructures by military regimes as well as by neo-populist politicians confirms the perennial nature of traditional religious mentalities and practices and not the rise of a democratic and tolerant religious modernity.

Textural characteristics and interpretation of second-cycle, debris-flow-dominated alluvial fans (Devonian of Northern Scotland)

Devonian conglomerates in Northern Scotland are interpreted as a product of recycling of pre-existing, variously reworked gravels and sands and deposition in a form of alluvial fans. These second-cycle fanglomerates fringe the western margin of the Golspie Basin (marginal sector of the Orcadian Basin) and are dominated by texturally heterogeneous, structureless debris-flow conglomerates of Facies B and B1. The textural heterogeneity of Facies B, manifested through chaotically arranged bimodal and polymodal textures, highly variable amounts of matrix and unremoulded sandy blocks, indicates that the cohesive and highly competent debris flows originated through remobilisation of previously reworked, sand-enriched gravels. The debris flows of Facies B1 formed as result of resedimentation and remoulding of two, texturally and compositionally distinct, groups of sediment—angular, poorly sorted, locally derived gravels and fine-grained, well sorted, exotic sands. The debris-flow deposits are accompanied by texturally homogeneous, massive to planar-stratified and cross-stratified conglomerates and sandstones of Facies C and C1. The latter deposits represent turbulent sheetfloods that were less competent than the debris flows and that acquired their sediment load through surficial reworking of the alluvial-fan gravels. Texturally homogeneous and structureless talus deposits of Facies A, and massive to planar-stratified sheetflood conglomerates of Facies C2 are locally derived and show first-cycle characteristics.

Children's Literacy and Public Schools in Latin America

Illiteracy problems in Latin America cannot be faced successfully without taking into account what actually happens at the beginning of primary school. Almost all children enter primary school, but those from marginal sectors of the population repeat the first grades one or more times and leave school before completion. Nonpromotion and low retention constitute the evidence of a deeper problem. Traditional school practices make the beginning of literacy more difficult precisely for those children who are more dependent on school help. The present situation may be overcome on the basis of research results generated in Latin America as well as innovative pedagogical experiences to improve literacy acquisition. If failure at the beginning of primary school continues as it is, the children of today will become the low-literate adults of tomorrow.

Depositional Characteristics of Suvero Submarine Slide, Paola Slope Basin, Eastern Tyrrhenian Margin: ABSTRACT

The Suvero submarine slide covers an area of about 225 km{sup 2} in the Paola slope basin on the eastern Tyrrhenian margin. The shape and lateral extent of the deposit, investigated by means of 1 and 30-kJ Sparker seismic profiles, strongly reflect the topographic confinement between the steep uppermost continental slope and a morphologic barrier formed by a margin-parallel slope ridge. The slide is small when compared with similar features on large delta-fed submarine fans or other slope-rise examples, but it constitutes a major depositional event relative to the size of the slope basin. No headwall and slide slip surface comparable in size with the slide deposit were found, suggesting that a significant part of the material flooring the slope basin became involved in the deformation and experienced some short-distance transport or internal shearing in response to a relatively small downslope-moving slide. The presence of small-relief ramps, over intervals of many kilometers, along the otherwise flat basal contact seems to indicate some strength and cohesion of the material involved. The development of a deep scour, localized where the regional gradient decreases from the steep upper slope to the flat basin floor, is also consistent with the occurrence of in-situ deformationmore » of underconsolidated sediments. The source area of the slide deposit lies in a margin sector where uplift was particularly effect during Pleistocene time (1 mm/year), causing the presence of steep upper-slope gradients and the generation of other small-scale creep and failure events.« less

Gustavo Gutierrez: Latin American Liberation Theology

Latin American liberation theology has become one of the more dynamic and controversial intellectual forces of contemporary Latin American politics. Although identified with a minority left‐wing perspective, liberation theology constitutes an important component within the larger context of progressive change in the political orientation of the Church in recent years. The chief inspiration for liberation theology stems from the Conference of Latin American Bishops at Medellin in 1968. The central theme of the Medellin conference was that Latin America lives beneath a tragic sign of under‐development: hunger, misery, illness, infant mortality, inequalities of income; tension between classes and outbreaks of violence; the lack of participation of people in decisions affecting the common good; an external position of neo‐colonial dependency. The privileged classes, it alleges, are insensitive to the miseries of the marginal sectors and frequently resort to force to repress opposition with “anti‐communism” or “keeping order” as the justification for their actions.

Surgical treatment of fractures of the proximal end of the radius in childhood.

In childhood, fracture of the neck of the radius is rather common. Generally the fracture is localized in the metaphysis, sometimes with involvement of the epiphysis. Marginal sector fractures, which are common in adults, are very rare. Different types of fractures, indications for surgical treatment, therapeutic procedures, and results are discussed.

Amaranth Flour Blends and Fractions for Baking Applications

Selected Amaranthus eruentus ecotypes from different places of origin were used to prepare baking products. Amylograph, alveograph and farinograph data of mixtures of white wheat flour with whole amaranth grain flour from raw, toasted and popped amaranth seeds, as well as with higher protein fractions obtained by air classification, presented clear differences with respect to wheat flour. Six selected amaranth lines displayed different behaviors according to their origin and the seeds, previous treatment. Results indicate the opportunity of employing wheat‐amaranth mixtures in programs developed to improve the diet of the population's marginal sectors. Enriched cookies and “bolillos” (French bread) with NPR values of 3.63 and 4.35, respectively, slightly higher than casein (3.0 and 4.0). are especially recommended for this purpose.

Shallow seismic stratigraphy and post-Albian geologic history of the northern and central Blake Plateau

Interpretation of >4,700 km of high-resolution, seismic-reflection profiles from the northern and central Blake Plateau was used to reconstruct the geologic history of this continental margin sector since Albian time. Beneath the northern Blake Plateau, a basal Albian sequence is overlain by three progradational sequences inferred to be Turonian-Coniacian, Santonian, and Campanian-Maastrichtian in age. Their clinoform patterns and external geometry suggest that these sequences consist of clastic sediment derived from a source to the west. The position of the seaward terminus of these sequences shifted by as much as 50 km during the Late Cretaceous, presumably in response to variations in the input of clastic sediment. To the south, the progradational units grade into thinner, blanketlike deposits interpreted as being deep-water sediments that accumulated in a slowly subsiding basin. By latest Cretaceous time, sediment was introduced to the inshore reaches of this deep-water basin apparently by a powerful, easterly flowing current sweeping through the Suwannee Strait of southern Georgia and northern Florida. Three thin, but mappable, units of Paleocene, Eocene-Oligocene, and post-Oligocene age comprise the Cenozoic section. Drill-hole data indicate that they consist principally of deep-water foraminiferal oozes and limestones. The dominant geologic agent during the Cenozoic was the Gulf Stream, the flow axis of which shifted periodically across the Plateau in response to global sea-level fluctuations. This powerful current influenced the location and development of the Florida-Hatteras Shelf and Slope, controlled facies distribution, and scoured the surface of the Blake Plateau, thereby producing an abbreviated sedimentary section containing numerous unconformities. The persistence of Gulf Stream erosion during the Cenozoic, in conjunction with crustal subsidence, transformed the distal edge of this continental margin sector into a deep-water, sediment-starved environment, the Blake Plateau.

An x-ray energy dispersive study of cellular compartmentalization of lead and zinc in Chlorella Saccharophila (Chlorophyta), Navicula incerta and Nitzschia closterium (bacillariophyta)

The compartmentalization of the heavy metals Pb and Zn was studied in Chlorella saccharophila, Navicula incerta and Nitzschia closterium using the STEM with dispersive X-ray spectrometer. Cells were exposed to the metals, at various concentrations, for 96 hr and then air dried on formvar coated grids. Lead was found to be concentrated in cell sectors with polyphosphate bodies in C. saccharophila at 13.3 ppm and in N. incerta and N. closterium at 10 ppm. Lead was also detected when the probe was placed on the cell margin (cell wall sector) of C. saccharophila at 25 ppm and 5.6 ppm in N. closterium. No Pb was detected in the cell margin sector (cell wall) of N. incerta at metal concentrations up to 10 ppm. In cells exposed to Zn, the metal was detected in polyphosphate body cell sectors in C. saccharophila starting at 1.0 ppm and in N. incerta starting at 2.3 ppm. Small amounts of Zn were detected in cell sectors away from polyphosphate bodies in C. saccharophila starting at 2.3 ppm. No Zn was detected in N. closterium at metal concentrations up to 2.3 ppm. It is suggested that the compartmentalization of the heavy metals Pb and Zn into polyphosphate bodies and the cell wall may be a means by which some algae reduce the toxicity of these cations. These means of sequestering heavy metals may also be a significant way in which heavy metals move, in large amounts, in the food chain.

Landlords, sharecroppers and agricultural labourers: Changing labour relations in Rural Java

Summary It has mainlv been the large landowners in Gondosari who have been in a position to take advantage of the modernisasi of agricultural production. Long before the seventies they enjoyed a dominant economic, social and political position in the village. Closely linked by family ties,7 they have occupied all the important positions (such as village head and members of the village administration) since the end of the last century. In this way they have been able to maintain and enlarge their economic power. Although several of them attempted to engage in commercial farming in the past, particularly in the twenties, until recently such efforts did not always meet with success. The cultivation of cash crops such as peanuts and kapok was practically under their complete control, but because profit margins were narrow, this did not lead to accumulation on a large scale. In the period 1930 to 1950, when monetized trade practically disappeared as a consequence of economic depression, war and revolution, commercial production was rather unattractive. Although the Indonesian government tried to create an “agricultural middle class” in the first years of independence, the efforts soon failed in Gondosari because of monetary inflation and the lack of an adequate economic infrastructure (roads, marketing) on the one hand and the political mobilization of small peasants and landless on the other. It was not until after a second major effort was made to increase commercial rice production through the Bimas programme in the wake of the 1965 military coup that the large owners in Gondosari could make the transition to “rural capitalism”. Capital investments were shown to bear fruit provided that production costs could be reduced by limiting the number of labourers and by cutting down wage in cash or in kind. Given its virtual monopoly of land ownership, the government support it has received, the growing number of landless households and the destruction of the peasants' unions, the village élite was able to carry its strategy into effect without too much opposition. The landlords are becoming “entrepreneurs” not only in agriculture, but also outside it. In Gondosari and some other villages they have introduced new rice hullers; purchased ‘Colts’ (pick-ups adapted for public transport) that visit all the main villages in the district; acquired diesel-powered generators, the electricity from which they sell to other villagers; and engaged in trade in agricultural produce (peanuts, chillies, cloves and citrus fruits). On the other hand, it is also they who purchase the imported luxury goods such as televisions, radios, motorbikes, cassette-recorders and amplifiers. In the houses of the village élite these have become common status symbols in recent years. The agricultural labourers have seen only the negative effects of this transition to rural capitalism, namely a drastic decrease in employment as the rationalization of rice and peanut production on the lands of the large landowners where they used to work has gradually resulted in the expulsion of their “superfluous labour”. In the absence of any other employment prospects they are increasingly driven into the marginal sectors of the village economy such as petty trade, various forms of handicrafts and cottage-industry and the illegal felling and selling of teak wood from the government forest. Such forms of activity generally provide much lower returns on labour. For the sharecroppers, commercialization of agriculture has led not to a decrease in employment, but ironically to its very opposite. Sharecroppers are now expected to make a greater financial and physical contribution to production for a proportionately smaller share in the harvest. The mode of production debate in India has shown that a developing rural capitalism does not necessarily put an end to precapitalist relations of production, but sometimes reinforces them (McEachern, 1976: 453). The case of Gondosari also shows that sharecropping for the large landowners is the most profitable relationship and is therefore also maintained in a commercial context.

Formation and distribution of gas-oil accumulations in the Paleozoic subsalt deposits of the northern marginal zone of the Caspian depression

We consider the formation and distribution of the gas--oil (gas-condensate) accumulations in the upper Paleozoic subsalt deposits of the northern marginal zone of the Caspian depression. On the basis of a detailed analysis of the geological, geochemical, and other conditions of preservation and conversion of the disseminated organic matter (DOM), we conclude that the principal sources of the hydrocarbons (HC) are the Devonian--Middle Carboniferous oil-source sequences. A result of the complex (stepped) migration of the hydrocarbons from these deposits, accumulations of oil and gas (gas-condensate) were formed in the Middle Carboniferous--Lower Permian deposits. From factual geological--geophysical and geochemical data, and also the results of sampling deep exploratory wells (the West Teplovo area), there is a possibility of discovering tectonically screened deposits of oil and gas in the marginal sectors of the basin, confined to the sunken blocks of structures and associated with faults in the subsalt Paleozoic sequence.

Mecanismos de articulación entre el sector informal y el sector formal urbano

This article utilizes field data from Mexico City squatter settlements and personal interviews with employers to analyze some aspects of social relations between the informal sector and the formal urban sector, and compares the results with findings of other anthropologists in Mexico and elsewhere to derive a series of theoretical generalizations concerning mechanisms of articulation between the marginal sector and the formal economic and political institutions of the society. The formal sector is postulated to consist of the 3 subsectors of power, capital, and labor, which are in permanent conflict among themselves but all of which enjoy labor security and an assured minimal level of income. The marginal or informal sector lacks employment security, a minimal income level, and bargaining power. It is characterized by a small scale economy utilizing intensive familial labor. The informal sector is marginal to the dominant industrial system of production and the state apparatus, although it fulfills functions in terms of the national economy. 2 types of relationships may be distinguished in the social organization of the marginal sector: reciprocal relations between equals which form a network for the exchange of goods and services, or patron/client relations which are used, for example, in the case of petty entrepreneurs utilizing their relatives and acquaintances to create units of production. The functions of reciprocal relations are affected by social, physical, economic, and psychosocial distance or proximity and may result in exchanges of information, labor assistance, loans, services, or moral support. Patron/client relations may be direct, or the "patron" may be an intermediary. Some reciprocal networks display a pattern of incipient asymmetry leading to formation of true patron/client ties and some petty entrepreneurs or intermediaries manage to develop true patron/client networks; case histories are used to illustrate both phenomena. Intermediaries functioning in the system of production and the political process are discussed. It is concluded that as long as members of the informal sector continue to be excluded from local and national institutions, intermediaries will be required to link the 2 sectors. The patron superimposes an element of inequality in his network of reciprocal relations, but his economic utility makes it necessary. At the same time, the prevailing lack of social mobility means that his true class position will not improve significantly.

On the political economy of urbanization in the Third World

Cette analyse de l'urbanisation d'aprés‐guerre en Afrique Occidentale est proposée comme un jalon pour l'économie politique de l'urbanisation dans le Tiers Monde. L'Afrique Occidentale est une des régions les moins urbanisées du monde qui cependant a récemment connu une urbanisation plus rapide que toute autre. Cette explosion urbaine est associée avec des inégalités sévères à trois niveaux: un déséquilibre profond dans les conditions de travail et de vie entre le secteur urbain et le secteur rural une forte concentration des ressources dans les capitales une énorme disparité économique à l'intérieur des villes entre les masses et une petit élite Si l'urbanisation en Afrique Occidentale est caractérisée par ces inégalités, il apparait qu'elle entraîne aussi des pertes économiques. Deux approches suggèrent que l'allocation des ressources est loin d'ětre optimale pour la croissance économique. D'une part des ressources sont gaspillées dans le chǒmage et le sous‐emploi urbain, dans la croissance des grands centres métropolitains, et dans la construction des ‘quartiers spontanés’. D'autre part la présupposition que la forme prise par l'urbanisation est le résultat d'une allocation optimale des ressources est mise en doute quand les facteurs qui affectent les paramètres économiques ou qui interferent directement avec les décisions d'investissement sont soumis à l'examen, et quand l'attention est dirigée sur le processus politique qui s'avère constamment dominé par les intérěts et les préoccupations d'un petit groupe de dirigeants.

Morphology off northern Honduras, northwestern Carribean Sea

Over 5500 km of sounding lines were used to construct a detailed bathymetric chart of the sea floor between Honduras and the southern Cayman Trough. The submarine morphology is related clearly to the tectonic setting. Complex transform faulting has ruptured the crust seaward of the Honduras continental margin into a series of deep grabens separated by irregular submarine ridges. Because of the proximity of the Cayman Trough, the western continental margin is a faulted platform characterized by an irregular shelf as narrow as 10 km and a steeply dipping slope; both shelf and slope have been modified substantially by the growth of thick reef masses. Further east, tectonism is reduced as a result of the divergent trends of the Cayman Trough and the Honduras continental margin. Consequently, the eastern margin sector is a depositional platform consisting mostly of a broad, smooth shelf and gentle slopes. Submarine erosion and local slumping have steepened the slope throughout the area.

Influence of estrogens on intraocular tension in the eyeballs of rabbits.

Iridocorneal angles from the eyes of female rabbits subjected to large doses of estrogens were examined under an electron scanning microscope. A temporary rise in intraocular tension was noted lasting up to 24 h after injection of estrogens, followed by a slow return to normal conditions. Histostructural changes of the iridicorneal angle were observed as widening of the marginal sector, enlarging of the dimple-shaped depressions and also increased number and narrowing of the micropores in the central part of the iridocorneal field. The authors postulate that estrogens affect the histostructure of the iridocorneal field and also stimulate the circulation of the aqueous fluid.

The economic structure and development of scanian fishing, 1870–1960

Abstract This investigation into the economic structure and development of Scanian (Map 1) fishing is based on different types of primary material from the statistics that report the sea fishing associated with the Scanian coastal communities and towns. The development will be analysed from 1870 to 1960, i.e. from a time when Sweden begins to transfer from agrarian society to industrial up to the time of highly industrialized society. Fishing is for the most part characterized as ancillary industry to farming. In Sweden, it plays a relatively insignificant role and is a marginal sector in this development. The reaction of marginal economic sectors during the industrialization process shows the spreading effect of the change.