4,099 research outputs found
Quantum cascade laser light propagation through hollow silica waveguides
In this paper, the transmission characteristics of hollow silica waveguides with bore diameters of 300 and 1000 ÎĽm are investigated using a 7.8-ÎĽm quantum cascade laser system. We show that the bore diameter, coiling and launch conditions have an impact on the number of supported modes in the waveguide. Experimental verification of theoretical predictions is achieved using a thermal imaging camera to monitor output intensity distributions from waveguides under a range of conditions. The thermal imaging camera allowed for more detailed images than could be obtained with a conventionally used beam profiler. The results show that quasi-single-mode transmission is achievable under certain conditions although guided single-mode transmission in coiled waveguides requires a smaller bore diameter-to-wavelength ratio than is currently available. Assessment of mode population is made by investigating the spatial frequency content of images recorded at the waveguide output using Fourier transform techniques
A problem in determining fitness differences
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65191/1/j.1469-1809.1977.tb00201.x.pd
A Cortical Region Consisting Entirely of Face-Selective Cells
Face perception is a skill crucial to primates. In both humans and macaque monkeys, functional magnetic resonance imaging (fMRI) reveals a system of cortical regions that show increased blood flow when the subject views images of faces, compared with images of objects. However, the stimulus selectivity of single neurons within these fMRI-identified regions has not been studied. We used fMRI to identify and target the largest face-selective region in two macaques for single-unit recording. Almost all (97%) of the visually responsive neurons in this region were strongly face selective, indicating that a dedicated cortical area exists to support face processing in the macaque
Exploring Prosopis Management and Policy Options in the Greater Horn of Africa: Proceedings of a Regional Conference, Addis Ababa, November 2014
Prosopis and the challenge itis posing has become a serious issue in most IGAD countries, affecting the livelihoods of farmers, agro-pastoral and pastoral communities. It has taken over farmland, browse and pasture, as well as reduced the water supply for people and for livestock in affected areas. Some governments have opted for expensive physical eradication methods which, however, are not proving effective. Others are trying alternative approaches which consider Prosopis an underutilised resource, rather than just an ecological menace
In search of the ice age tropics, a tribute to Prof. Daniel Livingstone and Prof. Paul Colinvaux
Hard, soft and thin governance spaces in land-use change: comparing office-to-residential conversions in England, Scotland and the Netherlands
In recent years, converting office buildings to residential use became a high-profile issue in the UK and in the Netherlands. There has, however, been differentiation in the policy response between England and Scotland (planning policy being devolved within the UK), and the Netherlands. We conceptualize this differentiation through the lens of variegated neoliberalism in the forms of hard, soft and thin governance spaces. England, where planning deregulation is more strongly adopted, represents a thin governance space. Scotland, where there has been little policy change, illustrates a hard governance space. The Netherlands represents a soft governance space, where proactive partnerships between government and developers predominate. This paper characterizes these distinct governance spaces and explores their impact on housing delivery and place-making, and the impact of underlying ideologies and planning culture(s) in governing office-to-residential conversions in the three countries. Drawing on national government assessments and statistics, interviews with stakeholders, and case study data from three cities: Leeds, Glasgow and Rotterdam, we conclude that while both hard and soft governance spaces, to different degrees and with different merits, are environments that enable planning, thin governance spaces – being driven more by ideology than notions of good governance – imply weak planning and place-making
The Australian Farm Business Management Network: Industry, Education, Consultancy and Research Coming Together
Under the sponsorship of the University of Sydney, on 5-6th December 2002 the future of farm management in Australia was discussed. The fundamental conclusion achieved by key primary industry representatives, corporate executives, academics, consultants and researchers is that farm management will have a more significant role to play in the future than previously in servicing the primary sector. The idea of farm management as a profession was proposed. Its basis would be business management supported by farming systems and technology, and using an holistic approach to action (i.e. finance, people and environment). The new profession of Farm Business Management would seek to influence education, research, consultancy and extension in Australia. Interested parties participating of the 2002 National Farm Management Workshop came away with the idea of championing a consultative network, constituted by interested institutions and interested individuals, as a first step in the process of nurturing the future development of farm business management. By integrating farmers and academics with corporate executives, consultants and researchers the objective is to behave as a consultative group. This group will influence educational models, implement consultancy and research strategies, and network in social and professional terms. Moreover, this network will provide a systematic opportunity for the channelling of farm business management and farming systems related information at different levels for education, extension and scientific purposes. This network is called the Australian Farm Business Management Network (AFBMnetwork).Institutional and Behavioral Economics,
Who gave whom hemoglobin S: The use of restriction site haplotype variation for the interpretation of the evolution of the Î’ S -globin gene
The hypothesis that three separate mutations to the Î’ S -globin gene have occurred in Africa in challenged. The distributions of the Î’ S and other Î’-globin haplotypes and a simulation of the diffusion of the Î’ S gene are presented and argued to be more in accord with the rapid diffusion of a single mutant that by recombination and gene conversion now occurs on several different haplotypes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38540/1/1310010309_ftp.pd
Human biodiversity: Genes, race, and history. By Jonathan Marks. New York: Aldine de Gruyter. 1995 321 pp. ISBN 0-202-02032-0. $23.95 (paper)
No Abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/37675/1/1330980109_ftp.pd
Cultural transmission and evolution: A quantitative approach. By L.L. Cavalli-Sforza and M.W. Feldman. Princeton, N.J.: Princeton University Press, 1981. xiv + 388 pp., figures, tables, bibliography, index. 10.50 (paper)
No Abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/37613/1/1330570318_ftp.pd
- …