Changes of the geological environment of the Northern Black Sea region and the chemicalization of agricultural production

The generalization of the data available, field and laboratory investigations made it possible to estimate the pesticide inflow with large rivers to the NW part of the Black Sea, and the degree of pollution of the soil cover, bottom sediments of water bodies, confined aquifers with pesticides and ground water with nitrates. As a result of the uncontrolled use of agrochemicals their residual quantities were found in 66–93% of the samples. In connection with economic activities the greatest damage was caused to the ground water — the main source of water supply in the region: in some areas the depletion of their resources, intrusion of sea water and salt ground waters into aquifers as well as presence of residual quantities of pesticides in concentrations exceeding the maximum permissible limit were detected.Ideas on limitation of the harmful impact of agrochemicals upon the region's environment are presented here.     

Geomorphology and the location of nuclear power plant sites: the Czechoslovakian experience

The need for secure sites for such sensitive installations as nuclear power plants and radioactive waste storage has brought increasing significance to the study of the geodynamic processes of the Earth's crust. Among other Earth sciences, geomorphology in Czechoslovakia is also participating in the study of both planning and operating nuclear power station sites. The experience of Czech geomorphologists has shown that the geomorphological information is necessary part of the accurate prediction of events and time which can endanger the security of nuclear power plants, radioactive waste storages, pipelines and other large installations. Geomorphological mapping and morphostructural analysis are important tools for such studies.     

Social network interactions among mentally ill persons in community housing: research issues and agenda

This paper discusses social network interactions among individuals who have been hospitalized with mental illness and who currently reside in different types of community housing programmes. First, a conceptualisation of social networks that focuses on network interactions, both supportive and non-supportive, between network interactions may be more important influences on successful or unsuccessful adaptation of current and former psychiatric patients to community life than the structural dimensions of social networks more commonly analysed in the literature. The design of a current longitudinal study of social network interactions is presented. The results of two pilot studies that examine social network interactions is presented. The results of two pilot studies that examine social network interactions with data from several community housing programmes in southern Ontario, Canada are reviewed and an agenda is stated for further data collection and analysis.     

Colonisation of the Krakatau islands by invertebrates

Arrival of invertebrates on the Krakatau islands, and the development of invertebrate assemblages there since 1883, are reviewed. Many data are imprecise, and difficulties of interpretation are outlined. A few well-known groups, such as butterflies, are used to suggest that much colonisation so far has been by relatively generalist species,and that the rate of addition of new species may become slower as the less vagile specialists characteristic of later successional vegetation may find natural colonisation harder. Studies of the assemblages developing in association with particular plant species are likely to be helpful in assessing future trends of invertebrate colonisation.     

Genetic change after colonization

Consideration is given to the case of a daughter population of a sexual species that becomes successfully established in an area previously lacking that species, as has occurred recently in the Krakataus. If the new area is isolated geographically and if the number of founder individuals is small, conventional wisdom foresees a reduction of genetic variability within the colony. This might obstruct genetic adjustment to new conditions. Recent studies of the genetics of such bottlenecked populations, however, show that, in some instances, genetic variability for quantitative traits may actually increase rather than decrease after a bottleneck event. Whereas loss of some quasi-neutral biochemical alleles may occur, the quantitative polygenic balances on which adaptation depends can be carried through the bottleneck into the new population. Novel phenotypes may result from natural selection during the generations that immediately follow the bottleneck. Growing shield volcanoes in particular show rapid turnover of their surfaces such that organisms surviving there must continually recolonize or become extinct. Such species, existing as metapopulations, should be prone to bottleneck effects that produce genetic shifts. Examples are given from Drosophila silvestris on the island of Hawaii. The relevance of such genetic shifts to population structure and evolutionary change in populations is discussed, emphasizing the probable role of metapopulation structure.     

Building in Israel throughout the ages

Conclusions Historical-botanical investigations carried out at various sites in Israel point to the use of Cedar of Lebanon wood for special construction purposes, during different periods, in various regions of the country (Tab 3).The cedar of Lebanon grows outside Israel and required a special system of commerce for it to be brought to the building sites. This included the felling of the trees in the mountains, their transportation to the coast, loading on ships, shipment or floating them by sea to Israel and its subsequent transportation to remote parts of the country. Such a commercial system could have existed only in a prosperous period characterised by a booming economy and a well-organised administration. These circumstances occurred in Palestine only from the Middle Bronze Age onwards up to the Crusaders period. Later on, during most of the Mameluk and the Ottoman periods (13th to 19th centuries), Palestine was a neglected place and an international trade in timber was in practical terms absent. Only in the second half of the nineteenth century Palestine regained part of the previous circumstances, which was characterised by the use of imported timber, firstly Near Eastern trees — the cedar of Lebanon as the most suitable one.The distribution pattern of cedar remnants in Israel is obvious and enables us to evaluate the wealth, economy, commerce, transportation systems and overall administration of the different regimes in Palestine during various periods in the past. Today there are only scattered groves and stands, most of these planted during the last decade to restore the cedar forests of the past. Therfore the evidence from Israel can show that the overexploitation of cedars for construction was one of the causes of the disappearance of the cedar forests in Lebanon and S Turkey throughout the ages.     

The use of the fracture reopening pressure in hydraulic fracturing stress measurements

Summary Practitioners of the hydraulic fracture stress measurement technique commonly estimate the hydraulic fracture tensile strength as the difference between the initial formation breakdown pressure and the fracture reopening pressure. This method, first suggested by Bredehoeft et al. (1976), was developed with the assumption that the stress state in the cracked formation is identical to the stress state in the uncracked formation. In this paper, a relationship for the fracture reopening pressure based on Linear Elastic Fracture Mechanics is developed that takes the hydraulically induced fracture into account. Situations in which the Bredehoeft technique can be appropriately applied are presented.     

Quaternary evolution of the Abu Quir bay,Egypt

The Pleistocene/Holocene history of Abu Quir bay and the adjacent shoreline has been studied using textural, petrological and geotechnical information obtained from 33 boreholes. The sedimentary vertical sequence is as follows reading from bottom to top: Late Pleistocene shelf sand and stiff mud, Late Pleistocene/Holocene transgressive sand, Holocene calcareous shelf mud, Holocene nearshore sand, prodelta mud, delta plain lagoonal and marsh mud, delta front mud and sand and coastal sand of beach and dunes. These units are produced as a response to shoreline fluctuation, resulting from a wide variety of deltaic and shelf environments. The study identifies delta lobes of the former Canopic branch which was located in the western part of the bay.     

“Industrial landscapes” as positive settings for tourism development in declining industrial cities —

This paper discusses the possibilities of revitalising declining industrial cities through tourism development. The main question is whether obsolete or declining industrial land uses in or around the city can be transformed into successful tourist land uses? Traditionally tourism and heavy industry have been considered contradictory land uses. The “industrial landscape” concept is developed here to show that undergiven circumstances, and because of the changing nature of modern industry, positive relations between the two could substantially contribute to the revitalisation process of the city. Two industrial zones within the city of Haifa, Israel, are used as a case study to show and evaluate how the concept can be implemented to bring about urban revitalisation through tourism development.     

Continental cloudiness changes this century

Surface-based observations of total cloud amount have been collected from historical records for four continents: North America, Europe, India and Australia. The records extend from 1900 to around 1985. Of the 350 individual station records investigated worldwide, 86% show an increase in total cloud amount or no change. In all four continents there is evidence of an increase in total cloud amount. This upward trend appears to be statistically significant for at least two regions: North America Australia. For North America this finding is corroborated by other recent studies.