871 research outputs found
Metabolism of carbon and nitrogen and the uptake of nutrients by crops in different soils treated with various organic materials
Imperial Users onl
A blueprint for building an instructional team
Combined teaching efforts give variety to the classroom
Systematics of the Water Snakes of the Nerodia Cyclopion Complex
The taxonomic status of the green water snake, Nerodia cyclopion, is re-evaluated. The two recognized subspecies are compared by using a variety of standard morphological characters, and significant differences are noted. Discriminant analysis of head-scale measurements provides highly significant separation of the two taxa. Examination of specimens from the zone of parapatry reveals no evidence of recent gene flow between the taxa. Based on these morphological data, plus the biochemical and ecological data of other workers, I suggest that the subspecies be recognized as full species, Nerodia eyelopion and Nerodia floridana
Adaptation strategies for self-organising electronic institutions
For large-scale systems and networks embedded in highly dynamic, volatile, and unpredictable
environments, self-adaptive and self-organising (SASO) algorithms have been proposed as
solutions to the problems introduced by this dynamism, volatility, and unpredictability. In open
systems it cannot be guaranteed that an adaptive mechanism that works well in isolation will
work well — or at all — in combination with others.
In complexity science the emergence of systemic, or macro-level, properties from individual, or
micro-level, interactions is addressed through mathematical modelling and simulation. Intermediate
meso-level structuration has been proposed as a method for controlling the macro-level
system outcomes, through the study of how the application of certain policies, or norms, can
affect adaptation and organisation at various levels of the system.
In this context, this thesis describes the specification and implementation of an adaptive affective
anticipatory agent model for the individual micro level, and a self-organising distributed institutional
consensus algorithm for the group meso level. Situated in an intelligent transportation
system, the agent model represents an adaptive decision-making system for safe driving, and the
consensus algorithm allows the vehicles to self-organise agreement on values necessary for the
maintenance of “platoons” of vehicles travelling down a motorway. Experiments were performed
using each mechanism in isolation to demonstrate its effectiveness.
A computational testbed has been built on a multi-agent simulator to examine the interaction
between the two given adaptation mechanisms. Experiments involving various differing combinations
of the mechanisms are performed, and the effect of these combinations on the macro-level
system properties is measured. Both beneficial and pernicious interactions are observed; the
experimental results are analysed in an attempt to understand these interactions.
The analysis is performed through a formalism which enables the causes for the various interactions
to be understood. The formalism takes into account the methods by which the SASO
mechanisms are composed, at what level of the system they operate, on which parts of the
system they operate, and how they interact with the population of the system. It is suggested
that this formalism could serve as the starting point for an analytic method and experimental
tools for a future systems theory of adaptation.Open Acces
Advancing Advance Care Planning in the Primary Care Setting
Despite providers agreeing that advance care planning counseling is within their scope of practice, many reported that they lack the time, education and resources needed to provide their patients with the counseling needed to make informed advance care planning decisions. In an effort to address the perceived time crunch described by many providers, we are seeking feedback on the accessibility and ease of utilization of the rapid assessment tool we created which should allow for PCP\u27s to quickly identify patients who could benefit from advance care planning interventions. First, providers at all levels were surveyed about their personal implementation of an AD, they completed basic demographic information about their current practices, and then they assessed and provided feedback about the rapid assessment tool we created. A total of 21 providers participated over a l 0-week period. 12 reported having their own documented advanced directive, 87 .5% reported time was indicated as a major barrier to ACP discussions and 47.6% of participants indicated they would very likely use a rapid assessment tool (RAT) if one was available to prompt them to engage their patients in ACP. At the conclusion of this study, we are able to demonstrate that time continues to significant barrier to patient-provider engagement, modifications were made to the RAT and recommendations for future implementation studies for this tool were established based on the subjective feedback of the participants
Predictive habitat modelling as a tool to assess the change in distribution and extent of an OSPAR priority habitat under an increased ocean temperature scenario:consequences for marine protected area networks and management
The aims of this study were to determine the extent and distribution of an OSPAR priority habitat under current baseline ocean temperatures; to illustrate the prospect for habitat loss under a changing ocean temperature scenario; and to demonstrate the potential application of predictive habitat mapping in "future-proofing" conservation and biodiversity management. Maxent modelling and GIS environmental envelope analysis of the biogenic bed forming species, Modiolus modiolus was carried out. The Maxent model was tested and validated using 75%/25% training/test occurrence records and validated against two sampling biases (the whole study area and a 20km buffer). The model was compared to the envelope analysis and the area under the receiver operating characteristic curve (Area Under the curve; AUC) was evaluated. The performance of the Maxent model was rated as 'good' to 'excellent' on all replicated runs and low variation in the runs was recorded from the AUC values. The extent of "most suitable", "less suitable" and "unsuitable" habitat was calculated for the baseline year (2009) and the projected increased ocean temperature scenarios (2030, 2050, 2080 and 2100). A loss of 100% of "most suitable" habitat was reported by 2080. Maintaining a suitable level of protection of marine habitats/species of conservation importance may require management of the decline and migration rather than maintenance of present extent. Methods applied in this study provide the initial application of a plausible "conservation management tool"
Adaptive management, international co-operation and planning for marine conservation hotspots in a changing climate
Acknowledgements This work received funding from the MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland) and their support is gratefully acknowledged. MASTS is funded by the Scottish Funding Council (Grant reference HR09011) and contributing institutions.Peer reviewedPublisher PD
Properties and productive potential of dystric brown soil on red sandstone in beech forests of "Čestobrodica"
Dystric brown soils were studied in the mountain forest of beech (Fagetum moesiacae montanum, Jov. 1976) in the area of the Management Unit "Čestobrodica". The soil study was carried out on three series of sample plots. The soils are formed on red sandstones, and the characteristics and the way of the substrate weathering has a decisive effect on the soil characteristics
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