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Institution

University of Bath

EducationBath, Bath and North East Somerset, United Kingdom
About: University of Bath is a education organization based out in Bath, Bath and North East Somerset, United Kingdom. It is known for research contribution in the topics: Population & Photonic-crystal fiber. The organization has 15830 authors who have published 39608 publications receiving 1358769 citations. The organization is also known as: Bath University.


Papers
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Journal ArticleDOI
TL;DR: An experimental study of supercontinuum generation in photonic crystal fibers with low-intensity femtosecond pulses provides evidence for a novel spectral broadening mechanism, and peculiarities of the measured spectra demonstrate that the reason for the white-light generation is fission of higher-order solitons into redshifted fundamentalsolitons and blueshifted nonsolitonic radiation.
Abstract: We report on an experimental study of supercontinuum generation in photonic crystal fibers with low-intensity femtosecond pulses, which provides evidence for a novel spectral broadening mechanism. The observed results agree with our theoretical calculations carried out without making the slowly varying envelope approximation. Peculiarities of the measured spectra and their theoretical explanation demonstrate that the reason for the white-light generation in photonic crystal fibers is fission of higher-order solitons into redshifted fundamental solitons and blueshifted nonsolitonic radiation.

553 citations

Journal ArticleDOI
TL;DR: In this paper, a process similar to the fractional Brownian motion has been used to model long-range dependence of returns while avoiding arbitrage, which is shown both indirectly and by constructing such an arbitrage.
Abstract: Fractional Brownian motion has been suggested as a model for the movement of log share prices which would allow long–range dependence between returns on different days. While this is true, it also allows arbitrage opportunities, which we demonstrate both indirectly and by constructing such an arbitrage. Nonetheless, it is possible by looking at a process similar to the fractional Brownian motion to model long–range dependence of returns while avoiding arbitrage.

552 citations

Journal ArticleDOI
TL;DR: The development of treatments for Alzheimer's disease during the past 30 years is reviewed, considering the drugs, potential targets, late‐stage clinical trials, development methods, emerging use of biomarkers and evolution of regulatory considerations to summarize advances and anticipate future developments.
Abstract: The modern era of drug development for Alzheimer's disease began with the proposal of the cholinergic hypothesis of memory impairment and the 1984 research criteria for Alzheimer's disease. Since then, despite the evaluation of numerous potential treatments in clinical trials, only four cholinesterase inhibitors and memantine have shown sufficient safety and efficacy to allow marketing approval at an international level. Although this is probably because the other drugs tested were ineffective, inadequate clinical development methods have also been blamed for the failures. Here, we review the development of treatments for Alzheimer's disease during the past 30 years, considering the drugs, potential targets, late-stage clinical trials, development methods, emerging use of biomarkers and evolution of regulatory considerations in order to summarize advances and anticipate future developments. We have considered late-stage Alzheimer's disease drug development from 1984 to 2013, including individual clinical trials, systematic and qualitative reviews, meta-analyses, methods, commentaries, position papers and guidelines. We then review the evolution of drugs in late clinical development, methods, biomarkers and regulatory issues. Although a range of small molecules and biological products against many targets have been investigated in clinical trials, the predominant drug targets have been the cholinergic system and the amyloid cascade. Trial methods have evolved incrementally: inclusion criteria have largely remained focused on mild-to-moderate Alzheimer's disease criteria, recently extending to early or prodromal Alzheimer disease or 'mild cognitive impairment due to Alzheimer's disease', for drugs considered to be disease modifying. The duration of trials has remained at 6-12 months for drugs intended to improve symptoms; 18- to 24-month trials have been established for drugs expected to attenuate clinical course. Cognitive performance, activities of daily living, global change and severity ratings have persisted as the primary clinically relevant outcomes. Regulatory guidance and oversight have evolved to allow for enrichment of early-stage Alzheimer's disease trial samples using biomarkers and phase-specific outcomes. In conclusion, validated drug targets for Alzheimer's disease remain to be developed. Only drugs that affect an aspect of cholinergic function have shown consistent, but modest, clinical effects in late-phase trials. There is opportunity for substantial improvements in drug discovery and clinical development methods.

551 citations

Journal ArticleDOI
12 Oct 1997-Nature
TL;DR: In this paper, a thread of coaligned multicellular filaments of Bacillus subtilis can be used to extend the length scale of inorganic materials patterning, and the resulting pore sizes are commensurate with the packing dimensions of the organic molecules.
Abstract: The synthesis of inorganic frameworks with specified and organized pore networks is of potential importance in catalysis1,2, separation technology3 and biomaterials engineering4,5. Ordered arrangements of porous channels have been produced in silica-based materials by post-synthetic removal of surfactant templates from inorganic–organic mesostructures6,7. The resulting pore sizes are commensurate with the packing dimensions of the organic molecules, and are currently limited to length scales of up to 10nm. Here we show how a bacterial superstructure, consisting of a thread of coaligned multicellular filaments of Bacillus subtilis8,9, can be used to extend the length scale of inorganic materials patterning. We produce ordered macroporous fibres of either amorphous silica or ordered mesoporous silica6,7 (MCM-41) by template-directed mineralization of the interfilament spaces followed by removal of organic material by heating to 600°C. The inorganic macrostructures consist of a macroporous framework of 0.5-μm-wide channels with curved walls of either silica or mesoporous silica, 50 to 200 nm in thickness. The formation of ordered pores in the MCM-41 replica on both the mesoscopic and macroscopic length scales illustrates how supramolecular and supercellular templates might be combined for the fabrication of inorganic materials with structural hierarchy.

548 citations

Journal ArticleDOI
TL;DR: The authors examine the growing disconnect between the process-oriented conception of entrepreneurship taught in the classroom and theorized about in premier journals and the variance-oriented notion of entrepreneurship that characterizes empirical studies of the phenomenon.
Abstract: We examine the growing disconnect between the process-oriented conception of entrepreneurship taught in the classroom and theorized about in premier journals and the variance-oriented conception of entrepreneurship that characterizes empirical studies of the phenomenon. We propose that a shift in inquiry from entrepreneurship as an act to entrepreneurship as a journey could facilitate process-oriented research by initiating a dialogue about the nature of the entrepreneurial journey, when it has begun and ended, whether it might be productively subdivided into variables or events, and what if anything remains constant throughout the process. Finally, we propose that a clearer understanding of the entrepreneurial journey is necessary to distinguish the field horizontally from research on creativity and strategy, and vertically from research on more practical business functions or more abstract systems-level concepts.

547 citations


Authors

Showing all 16056 results

NameH-indexPapersCitations
Michael Grätzel2481423303599
Brenda W.J.H. Penninx1701139119082
Amartya Sen149689141907
Gilbert Laporte12873062608
Andre K. Geim125445206833
Matthew Jones125116196909
Benoît Roux12049362215
Stephen Mann12066955008
Bruno S. Frey11990065368
Raymond A. Dwek11860352259
David Cutts11477864215
John Campbell107115056067
David Chandler10742452396
Peter H.R. Green10684360113
Huajian Gao10566746748
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202386
2022404
20212,474
20202,371
20192,144
20181,972