5,989 research outputs found
Prostate Biopsy Assistance System with Gland Deformation Estimation for Enhanced Precision
Computer-assisted prostate biopsies became a very active research area during
the last years. Prostate tracking makes it possi- ble to overcome several
drawbacks of the current standard transrectal ultrasound (TRUS) biopsy
procedure, namely the insufficient targeting accuracy which may lead to a
biopsy distribution of poor quality, the very approximate knowledge about the
actual location of the sampled tissues which makes it difficult to implement
focal therapy strategies based on biopsy results, and finally the difficulty to
precisely reach non-ultrasound (US) targets stemming from different modalities,
statistical atlases or previous biopsy series. The prostate tracking systems
presented so far are limited to rigid transformation tracking. However, the
gland can get considerably deformed during the intervention because of US probe
pres- sure and patient movements. We propose to use 3D US combined with
image-based elastic registration to estimate these deformations. A fast elastic
registration algorithm that copes with the frequently occurring US shadows is
presented. A patient cohort study was performed, which yielded a statistically
significant in-vivo accuracy of 0.83+-0.54mm.Comment: This version of the paper integrates a correction concerning the
local similarity measure w.r.t. the proceedings (this typing error could not
be corrected before editing the proceedings
Collagen-Fibrinogen Lyophilised Scaffolds for Soft Tissue Regeneration
A significant body of research has considered collagen as a scaffold material for soft tissue regeneration. The main structural component of extra-cellular matrix (ECM), collagen’s advantages over synthetic polymers are numerous. However, for applications where higher stiffness and stability are required, significant cross-linking may affect bioactivity. A carbodiimide (EDC) cross-linking route consumes carboxylate groups that are key to collagen’s essential cell recognition motifs (GxOGER). Fibrinogen was considered as a promising additive as it plays a key role in the process of wound repair and contains RGD integrin binding sites which bind to a variety of cells, growth factors and cytokines. Fibrinogen’s binding sites however, also contain the same carboxylate groups as collagen. We have successfully produced highly interconnected, porous collagen-fibrinogen scaffolds using a lyophilisation technique and micro-computed tomography demonstrated minimal influence of either fibrinogen content or cross-linking concentration on the scaffold structure. The specific biological effect of fibrinogen additions into cross-linked collagen are considered by using films as a model for the struts of bulk scaffolds. By considering various additions of fibrinogen to the collagen film with increasing degrees of cross-linking, this study demonstrates a significant biological advantage with fibrinogen addition across the cross-linking concentrations typically applied to collagen-based scaffolds.The authors wish to acknowledge the support of the European Research Council for the Advanced Grant 320598 awarded to REC and the EPSRC for the Established Career Fellowship EP/N019938/1 awarded to REC and SMB. They also wish to acknowledge funding for DB from the Peoples Programme of the EU 7th Framework Programme (RAE no: PHF-GA-2013-624904)
The use of ICT in the assessment of modern languages: the English context and European viewpoints
The ever increasing explosion of highly attractive multimedia resources on offer has boosted the use of information and communication technology (ICT) in the teaching and learning of modern languages. The use of ICT to assess languages is less frequent, however, although online testing is starting to develop. This paper examines the national context for the assessment of modern foreign language proficiency in England, outlines the kinds of assessment currently available and the development of electronic forms of assessment and compares the above with the survey results of a European Union (EU) funded project on current good practice in online assessment of languages in other European countries. The findings indicate that speaking is inadequately served by online testing as tests currently focus primarily on receptive language skills. The implications for future successful online testing include the incorporation of interactive skills and effective formative feedback
Knowledge-based systems programming for knowledge intensive teaching
Typological design implies extensive knowledge of building types in order to design a building belonging to a building type. It facilitates the design process, which can be considered as a sequence of decisions. The paper gives an outline of a new approach in a course teaching typological knowledge through the medium of Knowledge-Based Systems programming. It demonstrates how Knowledge-Based Systems offer an appropriate structure for analysing the knowledge required to implement typological design. The class consists of third-year undergraduate students with no extensive previous programming experience. The implementation language is AutoLISP which operates in the AutoCAD environment. The building type used in the course is the office building. In order to become acquainted with both building type andprogramming in AutoLISP, information and instructions have been gathered and prestructured, including a worked out analysis andAutoLlSP code. Office plans are generated through use of the Knowledge-Based System. They are encoded in the form offrames. At the end of the course the students will have learned the basics of Knowledge-Based Systems, have been introduced to programming these systems, have analysed and reflected upon the design process, and gained insight into a specific building type
Cardiac Autonomic Nervous System in Heart Failure: Imaging Technique and Clinical Implications
The autonomic nervous system interacts in the pathophysiology of heart failure. Dysfunction of the sympathetic nervous system has been identified as an important prognostic marker in patients with chronic heart failure. At present, cardiac sympathetic nerve imaging with 123-iodine metaiodobenzylguanidine [123-I MIBG] has been employed most frequently for the assessment of cardiac sympathetic innervation and activation pattern. The majority of studies have shown that cardiac sympathetic dysfunction as assessed with 123-I MIBG imaging is a powerful predictor for heart failure mortality and morbidity. Additionally, 123-I MIBG imaging can be used for prediction of potentially lethal ventricular tachyarrhythmias in heart failure patients. At present however, the lack of standardization of 123-I MIBG imaging procedures represents an evident issue. Standardized criteria on the use of 123-I MIBG imaging will further strengthen the clinical use of 123-I MIBG imaging in heart failure patients
NORFISK - an ecosystem simulation model for studies of the fish stocks off the coast of Norway
A biomass based ecosystem simulation model has been fitted to a
restricted area of the Norwegian coastal waters. The model uses a
holistic ecosystem approach and data on biomasses and their
interaction with each other have been taken from the Møre region,
western Norway. The main objective was to study interactions beetween
cod, haddock saithe and herring and their prey in this area. lnitial
estimation of the biomasses was based partly on acoustic methods and
partly on data from the literature. Sampling of stomach contents was
conducted to provide data for food composition tables. The
calculations in the model were based on biomasses only, but in the
analysis each species was treated as eggs and larvae, juveniles and
adults to give biomasses with relative homogeneous structure and
behaviour. The problems of intergroup recruitment and migration have
been discussed. The results indicate that using such a model as a tool
to treat data can give a better understanding of the ecosystem
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