bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of pollution from oil shale mining in Estonia
Authors: Vallner L. , Sepp K. 
Published: February 2007

AbstractThe largest commercially exploited oil shale deposit in the world is in northeast Estonia. the accumulation of solid residues by oil shale mines and processing plants has resulted in numerous dumps and ash hills, which are polluting the environment. the groundwater and streams are highly polluted by sulphates, phenols and oil products. a dump hill of radioactive wastes poses a serious threat to the Baltic Sea. Local people suffer from diseases more often than in other regions of Estonia.
Effects of heavy metals from mining and industry on some rivers in Poland: An already exploded chemical time bomb?
Authors: Suschka J. 
Published: February 2007

AbstractUpper Silesia has rich deposits of hard coal and substantial deposits of zinc, lead and iron ores. the watersheds of two rivers cut right through the zinc and lead ore mining region and most of the tailing drainage water is contaminated with heavy metals. in total, about 807 tyr‐1 of zinc, 67t yr‐1 of lead and 17 tyr‐1 of cadmium are discharged with the drainage and process waste water. in the Upper Silesia many industrial plants also discharge waste water contaminated with heavy metals. the Bukowno Complex is the most important regional source of heavy metals and the Biala Przemsza River is the main receiver of waste waters from this complex. Measured data at a cross‐section of this river are given. It is shown by a simplified calculation that lead and zinc are transported downstream to the Vistula River and later to the Baltic Sea, or are deposited in the river bed. It is shown that there are many other possible sources of heavy metals. Atmospheric deposition of metals on the surface leads to surface runoff, accumulation in plants, and subsequently discharge with animal or human excreta. Contaminated sediments will continue to pollute the overflowing river water, perhaps for centuries. Mobilization of heavy metals and factors affecting that process are discussed in relation to providing safe drinking water now and in the future. It is emphasized that the drinking water quality is already threatened.
Chemical dump sites in Poland
Authors: Zurek J. , Samsonowicz A. , Gosk E. 
Published: February 2007

AbstractRecent political and other changes have made it more difficult to manage and control Poland's numerous chemical dump sites. Many previous owners and managers of these sites are no longer in charge and valuable data, collected and stored locally, May, be lost if a countrywide inventory is not made soon. Previously unnoticed surface and groundwater pollution will then increase significantly. Three maps are presented showing the amounts of generated and stored hazardous wastes and the number of chemical dump sites in Poland. Further information is needed on site verification. It is proposed that a computerized database, combining existing and supplementary information, should be developed to provide the decision‐makers with a tool for establishing priorities for monitoring, protective measures and remedial action.
Long‐term environmental risks for soils, groundwaters and sediments in the danube catchment area: The danube chemical time bombs project
Authors: Várallyay G. , Salomons W. , Czíkós I. 
Published: February 2007

AbstractThe accumulation of pollutants in soils, sediments and groundwaters due to natural causes or as a consequence of human activities is a serious problem in the Danube region. the sudden release of the (temporarily) immobilized pollutants as a consequence of various soil degradation processes (acidification, salinization or alkalinization, The destruction of the soil structure and clay minerals, a decrease in the organic matter content and the buffering capacity) is even more harmful. This chemical time bomb phenomena significantly influences the present and future land and water use in the whole Danube catchment area and therefore has great practical significance. the aim of this project, as the first phase of an integrated environmental master plan, is to identify the problems, to delineate problem areas, to analyse the natural system (present status, vulnerability, future risks) and to develop the scientific tools and infrastructure for long‐term environmental risk assessment, which will be the scientific basis for the plan of action to prevent, eliminate or, at least, reduce the harmful side‐effects and the unfavourable ecological and economic consequences of the chemical time bomb in the Danube catchment area.
Effect of vegetation removal on airflow patterns and dune dynamics in the southwest Kalahari desert
Authors: Wiggs G. F. S. , Livingstone I. , Thomas D. S. G. , Bullard J. E. 
Published: February 2007

AbstractVegetation is a major control of dune surface activity. To assess the effect of removing vegetation from otherwise largely inactive sand‐dune surfaces, two field experiments were undertaken in the southwest Kalahari Desert of southern Africa. In the first, wind velocity profiles were measured on two flat surfaces, one vegetated and one where vegetation had been removed by fire. In the second, levels of dune surface activity were measured on burnt and vegetated sites over a ten week period. The data indicate a striking increase in the near‐surface wind velocity allied to a decrease in shear stress after the destruction of the vegetation canopy as a result of burning, grazing or drought. Measurements on the consequences of such changes in the airflow patterns on dune dynamics suggest a three‐fold increase in dune surface activity after vegetation clearance. The dunes therefore have a staggered response to the contemporary environment, being largely inactive relicts for much of the time, but becoming more active as vegetation is episodically removed.
Living with the past: Uses of history for understanding landscape change and degradation
Authors: Wasson R. J. 
Published: February 2007

AbstractThe analysis of land degradation is almost always ahistorical, and as a consequence is of diminished value. Global change, as it has come to be known, is thought of as a climatic phenomenon of this and the next century, but has actually been happening as a consequence of land use and climate variation for centuries. Land and water degradation are probably the most obvious manifestations of this global change. The various uses of historical analyses are exemplified in this paper to show their value as contextual explanations, possible analogues of future conditions, a library of experiments already performed, and a narrative of change.
Land‐use change and climate
Authors: Henderson‐Sellers A. 
Published: February 2007

AbstractHuman activities in Australia and world‐wide cause, or contribute to, desertification, deforestation, salinization and soil erosion, and also to reforestation, irrigation and landscape ‘management’. Human‐induced land‐use changes impact on the Earth's climate both locally and on a larger scale, right up to disturbance of the general circulation and hence the global climate. People have become a major environmental agent acting on the future climate through land‐use change, particularly deforestation (and reforestation), desertification (which often includes overgrazing and excessive exploitation of vegetation), agricultural expansion, and soil erosion and degradation. The largest impact of land‐use change on the future climate seems likely to be as a result of enhanced greenhouse gas emissions. At the same time, rapidly increasing populations, especially in the tropics, demand additional food, water for drinking and cleaning, and materials for the construction of shelters—all of which depend upon sustaining a reasonable climate. Climate and human land‐use requirements are linked, but the closeness of that link varies from intimate dependency to callous disdain. In this paper, the impacts of human‐induced land‐use changes on future climate are explored in the context of the projections of global climate models.
Indigenous soil and water conservation: A review of the state of knowledge and prospects for building on traditions
Authors: Critchley W. R. S. , Reij C. , Willcocks T. J. 
Published: February 2007

AbstractAfter half a century of failed soil and water conservation projects in tropical developing countries, technical specialists and policy makers are reconsidering their strategy. It is increasingly recognised that the land users have valuable environmental knowledge themselves. This review explores two hypotheses: first, that much can be learned from previously ignored indigenous soil and water conservation (ISWC) practices; second, that ISWC can often act as a suitable starting point for the development of technologies and programmes. However, information on ISWC is patchy and scattered. Many ancient, derelict systems are better described than traditions which still persist today. ISWC has been most commonly developed under dry and marginal conditions, and/or on steep hillsides. Sustained population pressure has often tended to stimulate ISWC. There is a need for more incorporation of ISWC into resource conservation programmes: many projects have ignored local traditions to their detriment. It is widely agreed that further study and research on ISWC is required and justified as a logical starting point towards developing adoptable and sustainable soil and water conservation systems for small‐scale farmers.
Nature, extent and severity of soil erosion in upland Scotland
Authors: Grieve I. C. , Davidson D. A. , Gordon J. E. 
Published: February 2007

AbstractThis paper examines the nature, extent and severity of soil erosion in upland Scotland, an area subject to land management pressures typical of temperate maritime uplands. Erosion features were classified and their area measured from aerial photographs. Some 12 per cent of the upland area sampled was subject to some form of erosion, which is very similar to the percentage for Europe as a whole. The most significant erosion category was peat erosion, with 6 per cent of the area being affected; a figure which increased to 20 per cent in one sub‐region. Peat erosion varied in severity, with the most severe erosion being in areas of eastern Scotland with the greatest land management pressures. Gully erosion of slopes on mineral soils was found in almost 5 per cent of the area sampled, particularly in sub‐regions with large amplitude of relief. Debris flow/cone features and screes were less extensive and largely found at higher altitudes. Footpath erosion was mapped in popular mountain areas, but overall the mean length of eroded footpaths was less than that of large gullies. There was little evidence of spatial linkages between erosion of mineral soils and land management at the scale of the survey. Separating the roles of upland management and extreme rainfall events in the inception of erosion remains a key issue in the study of accelerated erosion in temperate maritime upland areas. Some guidance for management is presented.
Erosion and soil productivity in Australia and New Zealand
Authors: Dregne H. E. 
Published: February 2007

AbstractSoil erosion assumes a different form in Australia and New Zealand. Sheet, rill and gully erosion are common in eastern Australia and wind erosion in the dry cropland areas. In New Zealand, mass movement dominates the erosion landscape but other kinds, including wind erosion, do occur. It is unclear how much of the mass movement is a natural phenomenon and how much is human‐induced. In either case, it causes long‐term reductions in soil productivity. A landmark analysis of the soil productivity loss due to land degradation was conducted by the Australian state of New South Wales. Water erosion was a greater problem than wind erosion, but soil structure deterioration was more costly than either kind of erosion.
Human activities and their impact on land degradation ‐ psilorites mountain in crete: A historical perspective
Authors: Lyrintzis G. , Papanastasis V. 
Published: February 2007

AbstractInformation ins presented on use of the natural resources of the Psilorites mountain in Crete throughour successive historical periods. The dominant human activities are described and their impact on hydrology, flora and fauna is analysed in an attempt to understand the land degradation processes on this Mediterranean mountain.
Soil degradation in the tropical lowlands of Santa Cruz, Eastern Bolivia
Authors: Barber R. G. 
Published: February 2007

AbstractThis paper examines the soil degradation processes that are threatening the productivity of the mechanized annual cropping areas in the Santa Cruz lowlands of tropical eastern Bolivia. The dominant process is that of machinery‐induced and natural compaction, which has resulted in an estimated 50 per cent of the soils in the Central Zone being moderately to severely compacted, causing serious root restriction and the loss of both transmission and water‐storage pores. Degradation has made the soils increasingly susceptible to moisture stress due to the combined effect of (i) restricted rooting as a result of compaction and the hardsetting characteristics of the soils, (ii) reduced rainfall infiltration due to the loss of transmission pores and surface crusting, and (iii) a decrease in available soil moisture caused by the loss of storage pores, the incorporation of wind‐blown fine sand deposits, and soil organic matter losses due to accelerated decomposition rates. The loss of transmission pores has also made the soils more prone to waterlogging in periods of high rainfall. The degradation tendencies of these soils are exacerbated by the greater variability of seasonal rainfall during the last 20 years that has led to a greater frequency or extremely high or extremely low rainfall events than hitherto.
Reclamation of degraded cocoa lands using Albizia Zygia
Authors: Anim‐Kwapong G. J. , Teklehaimanot Z. 
Published: February 2007

AbstractThe structure of the population of Albizia zygia and the regeneration potential of the species from seed were studied in three site conditions (mature cocoa stand, fallow and intact natural forest) in the moist semi‐deciduous forest zone in Ghana. The potential of the species to regenerate vegetatively was also assessed. Different population structures and different natural regeneration status were observed for each site. Regeneration from seed appeared to be of a little importance in the fallow site, whereas vegetative regeneration was found to be a major mechanism of secondary succession in abandoned cocoa farms. The population of Albizia zygia in the forest appeared to be stable, while in the mature cocoa fields it was in decline.Efficient seed pretreatment techniques and vegetative propagation methods using juvenile cuttings, which are useful for enhanced management of the species, are also presented.Management strategies using the species for the rehabilitation of degraded cocoa farms are discussed.
Influence of mineral fertilizers and different soil types on nutrient leaching: Results of lysimeter studies in East Germany
Authors: Meissner R. , Rupp H. , Seeger J. , Schonert P. 
Published: February 2007

AbstractA lysimeter experiment on mineral fertilizer use and soil type was begun in 1985 to study the interrelationships between the level of mineral fertilization and the leaching of nutrients. Increased application of mineral fertilizers brought about not only a significant reduction in effluence build‐up, but also a significant increase in yield. The lowest levels of nitrogen leaching were found in clay‐sand soil in use as grassland, and the highest in sandy soil used as arable land. Unexpectedly, the study was unable to prove statistically that a reduction in N, P and K leaching follows automatically from a reduction in mineral fertilization. Hence, suboptimal fertilization cannot be the only corrective measure if a noticeable or marked reduction in the adverse impact on water quality due to nutrient leaching is to be achieved. Interim plantings should be integrated in crop rotations. Agricultural crops must be siteadapted and suited to the fertilization regime.
Gully erosion associated with the expansion of unterraced almond cultivation in the coastal Sierra de Lujar, S. Spain
Authors: Faulkner H. 
Published: February 2007

AbstractSince Moorish times, the lower slopes of the Sierra de Lujar in southern Spain have been intensively cultivated. Despite steep slopes and the highly erodible nature of the local micaschist/quartzite bedrock and derivative Quaternary sequences, accelerated erosion has largely been contained throughout this history by substantial, well‐maintained rock terraces. However, since 1987, European Union (EU) agricultural policy has been to encourage the cultivation of certain crops by subsidising their expanded cultivation on a ‘per hectare’ basis. This has resulted in hasty clearance of native Mediterranean matorral on sites really unsuitable for the local staple crop (almonds), and erosion‐prevention terraces are often absent or rudimentary. Gullying is now a very serious problem on some of these newly cleared sites.This paper identifies the lithological, topographic and agricultural policy controls on the consequent gully distribution, and then explores the pedological and hydrological controls on gully initiation on a single unterraced slope. Using these results alongside morphological data from gully surveys, a gully initiation and growth model is presented. This suggests that two types of gully are present in the area. ‘Type 1’ or upper‐slope gullies are initiated by overland flows, which are relatively infrequent. By contrast, ‘type 2’ or slope‐base gully initiation involves saturation and collapse in fossil landslip scars in Holocene colluvium. These two very different morphological systems may integrate through the terminal fan of the upslope gullies, in a manner described by Tiexeira de Oliveira 1990. The implications of this are that in the study area, sediment removal is associated with a very few highly productive sites. Contemporary management is briefly assessed against this model of geomorphic change in the area.
Agroforestry developments and potential in the Brazilian Amazon
Authors: Smith N. J. H. , Fik T. J. , Alvim P. de T. , Falesi I. C. , SerrãO E. A. S. 
Published: February 2007

AbstractMuch attention in the media and scientific literature has focused on the destruction of tropical forests in Amazonia since the early 1970s, especially in the Brazilian states of Rondǒnia, Acre, Paré and Mato Grosso. Concern is mounting that the peeling back of the forests is wiping out biodiversity, destroying soil resources, possibly exacerbating global warming, and provoking land conflicts, among other socioeconomic and ecological problems. Yet little regard has been paid to some of the promising agricultural developments in the region that are helping to counteract pressures on the remaining forest while recuperating debilitated areas. In particular, a pronounced trend towards planting a mix of tree crops on small farms throughout the basin augers well for the future of the rainforest and more sustainable agriculture. Agroforestry developments in Amazonia underscore the linkages between conserving biodiversity and more productive and resilient agricultural systems.
Pricing bridges to cross a river
Authors: Bouhtou Mustapha , Grigoriev Alexander , Hoesel Stan van , van der Kraaij Anton F. , Spieksma Frits C.R. , Uetz Marc 
Published: February 2007

AbstractWe consider a pricing problem in directed, uncapacitated networks. Tariffs must be defined by an operator, the leader, for a subset of m arcs, the tariff arcs. Costs of all other arcs in the network are assumed to be given. There are n clients, the followers, and after the tariffs have been determined, the clients route their demands independent of each other on paths with minimal total cost. The problem is to find tariffs that maximize the operator's revenue. Motivated by applications in telecommunication networks, we consider a restricted version of this problem, assuming that each client utilizes at most one of the operator's tariff arcs. The problem is equivalent to pricing bridges that clients can use in order to cross a river. We prove that this problem is APX‐hard. Moreover, we analyze the effect of uniform pricing, proving that it yields both an m approximation and a (1 + lnD)‐approximation. Here, D is upper bounded by the total demand of all clients. In addition, we consider the problem under the additional restriction that the operator must not reject any of the clients. We prove that this problem does not admit approximation algorithms with any reasonable performance guarantee, unless P = NP, and we prove the existence of an n‐approximation algorithm. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007
Sudden onset blindness in sickle cell disease due to retinal artery occlusion
Authors: Liem Robert I. , Calamaras Diane M. , Chhabra Manpreet S. , Files Beatrice , Minniti Caterina P. , Thompson Alexis A. 
Published: February 2007

AbstractCentral retinal artery occlusion (CRAO) is a rare and potentially devastating cause of acute blindness in sickle cell disease (SCD) that is unique compared to classic sickle retinopathy. Few details related to this complication in SCD are known, including its risk factors, pathogenesis, presentation, treatment and outcomes. We present three patients with SCD and retinal artery occlusion. The overall variability in clinical presentation, treatment and prognosis reported in the literature underscores the need for a greater understanding of these factors as they relate to this complication in SCD. Pediatr Blood Cancer 2008;50:624–627. © 2007 Wiley‐Liss, Inc.
Treatment of children with diffuse intrinsic brain stem glioma with radiotherapy, vincristine and oral VP‐16: A Children's Oncology Group phase II study
Authors: Korones David N. , Fisher Paul G. , Kretschmar Cynthia , Zhou Tianni , Chen Zhengjia , Kepner James , Freeman Carolyn 
Published: February 2007

AbstractBackgroundThe prognosis for children with brain stem glioma remains grim. Based on studies suggesting efficacy of vincristine and oral VP‐16, The Pediatric Oncology Group (POG, now part of the Children's Oncology Group) conducted a study using these agents in combination with standard external beam radiation for children with newly diagnosed brain stem glioma.MethodsChildren were eligible for the study if they 3–21 years of age, had MRI‐evidence of a diffuse intrinsic pontine glioma, and had neurologic deficits of <6 months duration. Patients received local radiotherapy to a dosage of 54 Gy. Chemotherapy consisted of two 28‐day cycles of vincristine, 1.5 mg/m2, days 1, 8, and 15 and oral VP‐16, 50 mg/m2, days 1–21, starting concurrent with radiation, and continuing for ten cycles following radiation.ResultsOf the 31 children enrolled, 30 were eligible and evaluable for survival and toxicity. Their median age was 8 years (range 3–14 years). Seven patients (23%) had a partial response following radiation, 18 (60%) had stable disease, 2 (7%) had progressive disease, and response in 3 patients (10%) was not measured. All 30 children have died. Overall survival at 1 year was 27 ± 7% and at 2 years, 3 ± 2%. The median survival was 9 months (range 3–36 months). Hematologic toxicity was significant; other toxicities included constipation, mucositis, emesis, and infection.ConclusionThe addition of vincristine and oral VP‐16 to standard external beam radiation causes moderate toxicity and does not improve survival of children with diffuse intrinsic brain stem glioma. Pediatr Blood Cancer 2008;50:227–230. © 2007 Wiley‐Liss, Inc.