1,125 research outputs found

    Industrial Growth and the Subsistence Economy

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    A RJE conference paper on industrial growth and rural development of Rhodesia (now Zimbabwe). Paper presented at the Symposium for Industry In Rhodesia, June 11 & 12th, 1969.It goes without saying that, in any country, advance in one sector of the national economy will benefit the nation as a whole and may well have profound effects upon other sectors, and the purpose in presenting this paper is to examine the inter-relation of the subsistence or traditional sector and industrial growth in Rhodesia. At the outset, it is important to look at the present position in the traditional sector and consider the developmental possibilities that may exist, taking due account of the many difficulties that, doubtless, will be encountered in attempts to change the economic tempo and, thereby, the very lives of three-quarters of the total Rhodesian African population, who live in what is known as Tribal Trust Land, covering an area of some 40 million acres. The economy of our traditional sector is a rural one, families relying for their subsistence primarily on simple cultivation of the soil or on animal husbandry. In some cases, the income thus derived is supplemented by remittances from adult male members of the family who have found employment in the modern sector, but it will be appreciated that the modern sector cannot absorb more than a small fraction of the expanding population of the traditional sector and, obviously, this limits the extent to which incomes of families can be supplemented by such remittances

    Education for Participation

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    A conference paper on the need for participation of the black mnajority Africans in the economy of minority white ruled Rhodesia , via educational advancement, during the middle 1970's.The title that has been chosen for this Symposium, “African Participation in the Rhodesian economy”, is certainly topical. All of us are well aware, of course, that Africans do, in fact, play a major part in our economic life. In 1973, there were almost 900 000 of them in employment, earning nearly $320 million; buying power that stimulated economic activity very considerably. In some respects, the Rhodesia of today resembles the United States of America of something over a century ago. Like the United States of that time, we, today, have the majority of our people subsisting in the rural areas, while the industrial base of our economy is still relatively small

    Supporting arts and science communities on-line

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    This paper examines the use of the Web to support continuing professional development (CPD). It outlines the factors driving the adoption of CPD and highlights areas where the Web can aid in the development of successful professional communities. A survey examining the use of the Internet to support professionals working in the domains of the Arts and Science is presented. The study reviews twenty four sites for the presence and degree of adoption of several key features including: - community building, range and value of content, user friendliness and guidance, sophistication of employed Web technology

    The preservation of some East African freshwater fish

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    Quality changes during storage were investigated for several commercially important East African freshwater fish. Lates, Bagrus, Protopterus, Tilapia esculenta and T. nilotica were examined during storage in ice and at ambient temperature (250•C). After 24 hours at ambient temperature Lates and Bagrus were completely spoilt but Protopterus was still edible. In iced storage most fish were acceptable for at least 20 days. Organoleptic examination showed that T. nilotica was acceptable after 22 days storage in ice and that gutting was only marginally beneficial. Changes in physical appearance, which could form the basis of a fish inspection system, were recorded during storage. Possible chemical quality control indices were also investigated. It was found that total volatile bases and hypoxanthine are unlikely to be useful quality indices for the species studied with the possible exception of Lates. The bacterial counts of the flesh and skin of T. esculenta and T. niloticus were found to be low (a maximum of 10 organisms per sq cm of skin or per g of flesh) after 22 days storage in ice

    Synthesis of satellite (MODIS), aircraft (ICARTT), and surface (IMPROVE, EPA-AQS, AERONET) aerosol observations over eastern North America to improve MODIS aerosol retrievals and constrain surface aerosol concentrations and sources

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    We use an ensemble of satellite (MODIS), aircraft, and ground-based aerosol observations during the ICARTT field campaign over eastern North America in summer 2004 to (1) examine the consistency between different aerosol measurements, (2) evaluate a new retrieval of aerosol optical depths (AODs) and inferred surface aerosol concentrations (PM2.5) from the MODIS satellite instrument, and (3) apply this collective information to improve our understanding of aerosol sources. The GEOS-Chem global chemical transport model (CTM) provides a transfer platform between the different data sets, allowing us to evaluate the consistency between different aerosol parameters observed at different times and locations. We use an improved MODIS AOD retrieval based on locally derived visible surface reflectances and aerosol properties calculated from GEOS-Chem. Use of GEOS-Chem aerosol optical properties in the MODIS retrieval not only results in an improved AOD product but also allows quantitative evaluation of model aerosol mass from the comparison of simulated and observed AODs. The aircraft measurements show narrower aerosol size distributions than those usually assumed in models, and this has important implications for AOD retrievals. Our MODIS AOD retrieval compares well to the ground-based AERONET data (R = 0.84, slope = 1.02), significantly improving on the MODIS c005 operational product. Inference of surface PM2.5 from our MODIS AOD retrieval shows good correlation to the EPA-AQS data (R = 0.78) but a high regression slope (slope = 1.48). The high slope is seen in all AOD-inferred PM2.5 concentrations (AERONET: slope = 2.04; MODIS c005: slope = 1.51) and could reflect a clear-sky bias in the AOD observations. The ensemble of MODIS, aircraft, and surface data are consistent in pointing to a model overestimate of sulfate in the mid-Atlantic and an underestimate of organic and dust aerosol in the southeastern United States. The sulfate overestimate could reflect an excessive contribution from aqueous-phase production in clouds, while the organic carbon underestimate could possibly be resolved by a new secondary pathway involving dicarbonyls

    Ariel - Volume 4 Number 7

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    Editors David Jacoby Eugenia Miller Tom Williams Associate Editors Paul Bialas Terry Burt Michael Leo Gail Tenikat Editor Emeritus and Business Manager Richard J. Bonnano Movie Editor Robert Breckenridge Staff Richard Blutstein Mary F. Buechler J.D. Kanofsky David Mayer Rocket Webe

    Mineral exploration in the Lower Palaeozoic rocks of south-west Cumbria. Part 1, regional surveys

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    The results of geochemical, geological and geophysical surveys over Lower Palaeozoic rocks in the south-western part of Cumbria are given in two reports. This report (Part 1) describes the results of a geochemical drainage survey and an examination of mineralised sites, and relates them to information from new geological mapping and an assessment of regional geophysical data. Part 2 contains details of follow-up surveys in the Black Combe inlier. The geochemical drainage survey, involving the collection and analysis of heavy mineral concentrates and stream sediment samples from 119 sites, found substantial antimony, arsenic, barium, bismuth, copper, iron, lead, tin, tungsten and zinc anomalies. Gold was reported for the first time from this part of the Lake District: small amounts were noted in panned concentrates from five sites. Other minerals identified in panned concentrates included arsenopyrite, baryte, bismutite, bismuthinite, cassiterite, chalcopyrite, cerussite, pyrite, pyromorphite, scheelite, sphalerite, stolzite and wolfram&e. The examination of old workings and outcrops revealed many undocumented occurrences of quartzsulphide vein-style mineralisation. The chemical analysis of samples taken from old workings and other occurrences confirmed field observations that locally, particularly in the Black Combe area, this mineralisation is polymetallic with variable amounts of arsenic, gold, bismuth, copper, lead, zinc and in a few cases antimony, barium, cobalt, nickel, tungsten and tin. Iron mineralisation occurs both as oxide (hematite) and sulphide deposits. Mercury was present in appreciable amounts in samples from the High Brow pyrite mine. The distribution of panned concentrate anomalies suggests that the vein-style mineralisation is polyphase and that individual phases may be zoned. Highest zinc anomalies occur near Torver and the highest lead on the west side of Black Combe. Tin and tungsten are restricted largely to the central part of Black Combe, and the most prominent arsenic and bismuth anomalies are found in the same area. Copper anomalies are widespread over the Skiddaw Group and the Borrowdale Volcanic Group. Barium anomalies indicate that baryte mineralisation is weak and localised, occurring principally within the Black Combe area and close to the Windermere Supergroup basal unconformity. Iron oxides from host rocks and hematite mineralisation are responsible for local enrichments of iron, antimony, arsenic and molybdenum in panned concentrates

    Collineation group as a subgroup of the symmetric group

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    Let Ψ\Psi be the projectivization (i.e., the set of one-dimensional vector subspaces) of a vector space of dimension ≥3\ge 3 over a field. Let HH be a closed (in the pointwise convergence topology) subgroup of the permutation group SΨ\mathfrak{S}_{\Psi} of the set Ψ\Psi. Suppose that HH contains the projective group and an arbitrary self-bijection of Ψ\Psi transforming a triple of collinear points to a non-collinear triple. It is well-known from \cite{KantorMcDonough} that if Ψ\Psi is finite then HH contains the alternating subgroup AΨ\mathfrak{A}_{\Psi} of SΨ\mathfrak{S}_{\Psi}. We show in Theorem \ref{density} below that H=SΨH=\mathfrak{S}_{\Psi}, if Ψ\Psi is infinite.Comment: 9 page

    Steiner t-designs for large t

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    One of the most central and long-standing open questions in combinatorial design theory concerns the existence of Steiner t-designs for large values of t. Although in his classical 1987 paper, L. Teirlinck has shown that non-trivial t-designs exist for all values of t, no non-trivial Steiner t-design with t > 5 has been constructed until now. Understandingly, the case t = 6 has received considerable attention. There has been recent progress concerning the existence of highly symmetric Steiner 6-designs: It is shown in [M. Huber, J. Algebr. Comb. 26 (2007), pp. 453-476] that no non-trivial flag-transitive Steiner 6-design can exist. In this paper, we announce that essentially also no block-transitive Steiner 6-design can exist.Comment: 9 pages; to appear in: Mathematical Methods in Computer Science 2008, ed. by J.Calmet, W.Geiselmann, J.Mueller-Quade, Springer Lecture Notes in Computer Scienc

    Using big data to improve ecotype matching for Magnolias in urban forestry

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    Trees play major roles in many aspects of urban life, supporting ecosystems, regulating temperature and soil hydrology, and even affecting human health. At the scale of the urban forest, the qualities of these individual trees become powerful tools for mitigating the effects of, and adapting to climate change and for this reason attempts to select the right tree for the right place has been a long-term research field. To date, most urban forestry practitioners rely upon specialist horticultural texts (the heuristic literature) to inform species selection whilst the majority of research is grounded in trait-based investigations into plant physiology (the experimental literature). However, both of these literature types have shortcomings: the experimental literature only addresses a small proportion of the plants that practitioners might be interested in whilst the data in the heuristic (obtained through practice) literature tends to be either too general or inconsistent. To overcome these problems we used big datasets of species distribution and climate (which we term the observational literature) in a case study genus to examine the climatic niches that species occupy in their natural range. We found that contrary to reports in the heuristic literature, Magnolia species vary significantly in their climatic adaptations, occupying specific niches that are constrained by trade-offs between water availability and energy. The results show that not only is ecotype matching between naturally-distributed populations and urban environments possible but that it may be more powerful and faster than traditional research. We anticipate that our findings could be used to rapidly screen the world’s woody flora and rapidly communicate evidence to nurseries and plant specifiers. Furthermore this research improves the potential for urban forests to contribute to global environmental challenges such as species migration and ex-situ conservation
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