Small commercial fishing vessels are the largest, most diverse, and constantly evolving class of marine vessels in existence. Yet the methods used to evaluate their stability reflect a one size fits all approach with ...
详细信息
Small commercial fishing vessels are the largest, most diverse, and constantly evolving class of marine vessels in existence. Yet the methods used to evaluate their stability reflect a one size fits all approach with little improvement over the many decades since their introduction in the early 1900s. This conflict coupled with significant flaws in the methods used to convey stability guidance to the crews leads to unacceptable risks being taken and fishing vessels and their crews being lost. Improvements are needed in all areas of small commercial fishing vessel analysis: better criteria that reflect the true dynamic environment faced by the crews, better means to convey stability guidance, including the current risk of capsize to the crews, and lastly a program to teach stability and how to use the guidance provided.
The assumption of the work presented in this paper is the situatedness of the change process. The Enterprise Knowledge Development-Change Management Method (EKD-CMM) provides multiple and dynamically constructed ways ...
详细信息
The assumption of the work presented in this paper is the situatedness of the change process. The Enterprise Knowledge Development-Change Management Method (EKD-CMM) provides multiple and dynamically constructed ways of working to organize and to guide the change management. The method is built on the notion of labeled graph of intentions and strategies called a road map and the associated guidelines. The EKD-CMM road map is a navigational structure that supports the dynamic selection of the intention to be achieved next and the appropriate strategy to achieve it whereas guidelines help in the operationalization of the selected intention following the selected strategy. This paper presents the EKD-CMM road map and guidelines and exemplifies their use with a real case study. (C) 2002 Elsevier Science B.V. All rights reserved.
A method based on computer vision for detection and localisation of crop rows, especially of small-grain crops, is described. The method is intended for use in a system for automatic guidance of agricultural implement...
详细信息
A method based on computer vision for detection and localisation of crop rows, especially of small-grain crops, is described. The method is intended for use in a system for automatic guidance of agricultural implements in selective treatment of rows and/or inter-row spaces, e.g. with an inter-row cultivator. The computer vision system consists of a colour video camera and a computer. The camera is focussed on the field surface from an inclined angle to obtain images that cover up to about five rows simultaneously. New images are continuously transferred to the computer, which processes them and calculates the necessary lateral movements of the implement. The processing method does not include a segmentation step, which is found in-most other methods for plant detection. The segmentation step has been replaced by,computation of centres of gravity for row segments in the image. This approach has proven-to reduce the computational burden of the image processing software. The estimation of the orientation and the lateral position of the centre lines of the rows is accomplished by weighted linear regression. The accuracy of the estimation was determined by comparing the calculated row centre line with the position of a reference string, which was placed parallel to the row along the centre line of an adjacent inter-row space. (C) 2002 Elsevier Science B.V. All rights reserved.
Vibration induced by an alternating magnetic field is proposed as a method for the identification of modified brachytherapy seeds with Doppler ultrasound. In vitro experiments,with agar and liver-tissue phantoms using...
详细信息
Vibration induced by an alternating magnetic field is proposed as a method for the identification of modified brachytherapy seeds with Doppler ultrasound. In vitro experiments,with agar and liver-tissue phantoms using a clinical scanner and simple apparatus demonstrate that the technique is feasible.
Rationale and Objectives. The purpose of this study was to develop and test new assistive devices to aid in the performance of safe, easy, and accurate microwave thermocoagulation therapy guided by magnetic resonance ...
详细信息
Rationale and Objectives. The purpose of this study was to develop and test new assistive devices to aid in the performance of safe, easy, and accurate microwave thermocoagulation therapy guided by magnetic resonance (MR) imaging. Materials and Methods. An open-configuration MR imager with an optical tracking system for image plane control and a microwave coagulator operating at 2.45 GHz were used. Liver tumors were percutaneously punctured under the guidance of MR images and ablated. Handpiece adapters were then prepared for the optical tracking system. An MR-compatible endoscopic system also was used. Navigation software was installed and customized. These devices were combined to provide near-real-time MR image-guided navigation during thermocoagulation therapy for liver tumors. Results. The handpiece adapters improved the flexibility of approaches for percutaneous puncture of tumors. The MR-compatible endoscope was used as a thoracoscope, and tumors just below the diaphragm were safely and easily punctured through the diaphragm. The customized navigation software displayed near-real-time MR images together with two reformatted images (on the same plane and on a perpendicular plane) from the registered high-resolution three-dimensional data. enabling, accurate MR imaging navigation. Conclusion. These new assistive devices made it easier to perform safe, easy, and accurate MR-guided thermocoagulation therapy of liver tumors.
In the present study, the influence of astrocyte alignment on the direction and length of regenerating neurites was examined in vitro. Astrocytes were experimentally manipulated by different approaches to create longi...
详细信息
In the present study, the influence of astrocyte alignment on the direction and length of regenerating neurites was examined in vitro. Astrocytes were experimentally manipulated by different approaches to create longitudinally aligned monolayers. When cultured on the aligned monolayers, dorsal root ganglion neurites grew parallel to the long axis of the aligned astrocytes and were significantly longer than controls. Engineered monolayers expressed linear arrays of fibronectin, laminin, neural cell adhesion molecule, and chondroitin sulfate proteoglycan that were organized parallel to one another, suggesting that a particular spatial arrangement of these molecules on the astrocyte surface may be necessary to direct nerve regeneration in vivo. In contrast, no bias in directional outgrowth was observed for neurites growing on unorganized monolayers. The results suggest that altering the organization of astrocytes and their scar-associated matrix at the lesion site may be used to influence the direction and the length of adjacent regenerating axons in the damaged brain and spinal cord. (C) 2003 Elsevier Science (USA). All rights reserved.
During development, primary olfactory axons typically grow to their topographically correct target zone without extensive remodelling. Similarly, in adults, new axons arising from the normal turnover of sensory neuron...
详细信息
During development, primary olfactory axons typically grow to their topographically correct target zone without extensive remodelling. Similarly, in adults, new axons arising from the normal turnover of sensory neurons essentially project to their target without error. In the present study we have examined axon targeting in the olfactory pathway following extensive chemical ablation of the olfactory neuroepithelium in the P2-tau:LacZ line of mice. These mice express LacZ in the P2 subpopulation of primary olfactory neurons whose axons target topographically fixed glomeruli on the medial and lateral surfaces of the olfactory bulb. Intraperitoneal injections of dichlobenil selectively destroyed the sensory neuroepithelium of the nasal cavity without direct physical insult to the olfactory neuron pathway. Primary olfactory neurons regenerated and LacZ staining revealed the trajectory of the P2 axons. Rather than project solely to their topographically appropriate glomeruli, the regenerating P2 axons now terminated in numerous inappropriate glomeruli which were widely dispersed over the olfactory bulb. While these errors in targeting were refined over time, there was still considerable mis-targeting after four months of regeneration.
This paper is in response to a previous article;in a Special Issue of Toxicology Letters. That article criticised the current regulatory framework in the European, Union for the environmental risk assessment of veteri...
详细信息
This paper is in response to a previous article;in a Special Issue of Toxicology Letters. That article criticised the current regulatory framework in the European, Union for the environmental risk assessment of veterinary medicinal products (VMPs) and feed additives (FAs), in particular the ongoing process of international harmonisation of guidance. This response addresses the concerns raised in relation to veterinary medicinal products and demonstrates that the VICH process has been brought within the scope of current EU regulatory processes for veterinary medicines and therefore is not separate to them. Consultation with stakeholders takes place throughout the VICH process, with an additional period of open public consultation before guidance is adopted and implemented. (C) 2003 Elsevier Science Ireland Ltd. All rights reserved.
Coordinated motor behaviors rely on a maze-like network of axonal connections between motoneurons and the body musculature. Since the time of the Renaissance, scientists have been fascinated by the question of how suc...
详细信息
Coordinated motor behaviors rely on a maze-like network of axonal connections between motoneurons and the body musculature. Since the time of the Renaissance, scientists have been fascinated by the question of how such complex, yet stereotypic, connectivity arises during embryogenesis. Here. we review the long journey of motor axons, which traverse diverse territories along predetermined routes riddled with a wealth of divergent pathway options. We conclude that motor axon migration occurs in a stepwise manner, with each step being controlled by local guidance cues, that motor axons rely on some of the same cues that also control axon migration within the CNS, and that, due to species-specific anatomical variations, the cell types providing such local cues may vary. Although studies of motor axon migration have not yet resulted in a complete understanding of the cellular and molecular mechanisms regulating this process, we have come a long way since the days of da Vinci. (C) 2003 Elsevier Inc. All rights reserved.
Neuroembryogenesis critically depends on signaling molecules that modulate cell proliferation, differentiation, and the formation of neural networks. In an attempt to identify potential morphogenetic active components...
详细信息
Neuroembryogenesis critically depends on signaling molecules that modulate cell proliferation, differentiation, and the formation of neural networks. In an attempt to identify potential morphogenetic active components that are distributed in a graded fashion in the developing nervous system, we generated substraction libraries of the embryonic nasal and temporal chick retina. Selected clones were analyzed by sequencing, Northern and Western blotting, in situ hybridization, and immunocytochemistry. Retinal fatty acid-binding protein (R-FABP) mRNA displayed the most pronounced topographic gradient. R-FABP was most strongly expressed in nasal retina, though topographic differences were not evident on the protein level. R-FABP expression was subject to a pronounced spatio-temporal regulation. Peak expression was at the period of cell generation/migration and differentiation. To identify the cell types involved in R-FAPB synthesis, ganglion cells as the only retinal projection neurons were enriched by enzymatic delayering. Cell somata, axons, and growth cones were R-FABP immunoreactive. Most interestingly, R-FABP immunoreactivity was critically dependent on the growth substratum. It was abrogated when axons grew on isolated glial endfeet. Radial glia purified by complement-mediated cytolysis also expressed R-FABP at moderate levels. The expression level was significantly increased during mitosis and dropped down again in postmitotic cells. Further on, transient loss of cell-cell and substratum contact induced a subcellular redistribution of R-FABP. In conjunction with the morphogen-binding activity of other FABP family members and their impact on cell migration and tissue differentiation, R-FABP characteristics suggest a regulatory function during retinal histogenesis but not during topographic map formation. (C) 2003 Elsevier Science (USA). All rights reserved.
暂无评论