The role of 'naturalness' and seral stage in the assessment and management of coastal sites

Conservation and restoration of Mediterranean coastal habitats often requires rapid assessment of the ‘state of health’ of the environment. A potential solution to this issue may be represented by the implementation of a method for rapid assessment of the ‘naturalness’ of coastal areas. The degree of naturalness of a site is diagnosed by sampling and analysing the anthropogenicity of the ecosystem in the area, and, from its inverse interpretation, the naturalness grade that characterises the habitat may be deduced. We are suggesting that the principal criterion for defining values of naturalness in the upper part of the scale should be the position of a terrestrial plant community along a sere. Using species richness as a criterion for naturalness would probably not be suitable, as this value is fundamentally a statistic and does not give any information regarding the ‘state of health’ of the ecosystem. As such, the identity of the species, rather than their number would be a better indicator of naturalness. A natural habitat, one that has been undisturbed by human actions, would be characterized by a primary climax community. Disturbances (man-made and otherwise) would act to erode the integrity of the climax community and would introduce other species (usually opportunistic species) which would occupy disturbed patches and coexist with the climax vegetation. A disturbance of very large magnitude would revert the succession to early seral stages which would subsequently proceed (if undisturbed) through a secondary succession, reaching a secondary climax. When actively managed sites were compared to unmanaged coastal areas in the Maltese islands, it was found that the former were statistically more likely to show a higher position in the seral stage of the vegetation community. This emphasizes the fact that some kinds of human disturbances do not reduce the naturalness value of a site. In fact, active management and conservation practices that entail a proper strategic plan should be considered. This allows managers to spatially and temporally determine the position of a plant community along a sere and would provide them with a rapid indication of how different types and intensities of negative human disturbance affect coastal vegetation.peer-reviewe

A constraint programming approach to the hospitals/residents problem

An instance I of the Hospitals/Residents problem (HR) involves a set of residents (graduating medical students) and a set of hospitals, where each hospital has a given capacity. The residents have preferences for the hospitals, as do hospitals for residents. A solution of I is a <i>stable matching</i>, which is an assignment of residents to hospitals that respects the capacity conditions and preference lists in a precise way. In this paper we present constraint encodings for HR that give rise to important structural properties. We also present a computational study using both randomly-generated and real-world instances. We provide additional motivation for our models by indicating how side constraints can be added easily in order to solve hard variants of HR

Systems management techniques and problems

Report is reviewed which discusses history and trends of systems management, its basic principles, and nature of problems that lend themselves to systems approach. Report discusses systems engineering as applied to weapons acquisition, ecology, patient monitoring, and retail merchandise operations

Post processing of multimedia information - concepts, problems, and techniques

Currently, most research work on multimedia information processing is focused on multimedia information storage and retrieval, especially indexing and content-based access of multimedia information. We consider multimedia information processing should include one more level-post-processing. Here &quot;post-processing&quot; means further processing of retrieved multimedia information, which includes fusion of multimedia information and reasoning with multimedia information to reach new conclusions. In this paper, the three levels of multimedia information processing storage, retrieval, and post-processing- are discussed. The concepts and problems of multimedia information post-processing are identified. Potential techniques that can be used in post-processing are suggested, By highlighting the problems in multimedia information post-processing, hopefully this paper will stimulate further research on this important but ignored topic.<br /

Techniques, problems and uses of mega-geomorphological mapping

A plea for a program of global geomorphological mapping based on remote sensing data is presented. It is argued that the program is a necessary step in bringing together the rapidly evolving concepts of plate tectonics with the science of geomorphology. Geomorphologists are urged to bring temporal scales into their subject and to abandon their recent isolation from tectonics and geological history. It is suggested that a start be made with a new geomorphological map of Europe, utilizing the latest space technology

Acoustic holography: Problems associated with construction and reconstruction techniques

The implications of the difference between the inspecting and interrogating radiations are discussed. For real-time, distortionless, sound viewing, it is recommended that infrared radiation of wavelength comparable to the inspecting sound waves be used. The infrared images can be viewed with (IR visible) converter phosphors. The real-time display of the visible image of the acoustically-inspected object at low sound levels such as are used in medical diagnosis is evaluated. In this connection attention is drawn to the need for a phosphor screen which is such that its optical transmission at any point is directly related to the incident electron beam intensity at that point. Such a screen, coupled with an acoustical camera, can enable instantaneous sound wave reconstruction