3,413 research outputs found
Explaining participation rates in recreational fishing across industrialised countries
On average, 10.52% of the total population was found to fish for recreation across the industrialised world (N = 27 countries), amounting to an estimated 118 million (95% confidence interval 81–154 million) people in North America, Europe and Oceania. Participation rates declined with population density and gross domestic product, indicating a negative effect of urbanisation and post-modernisation on fishing interest. Participation rates also declined with increasing median age, average household size and unemployment rate, suggesting resource limitation to constrain participation in fishing. By contrast, two indicators of the cultural importance of fish (fish landings and per capita fish consumption) and an indicator of perceived need for leisure (weekly working hours) were positively correlated with fishing participation. Based on these findings, which explained 60% of the variance in fishing participation across the industrialised world, reduced fishing interest is to be expected with post-industrialisation. Dedicated management and marketing intervention is needed to reverse the track of diminishing fishing interest in industrialised countries
Readout and Control of a Power-recycled Interferometric Gravitational-wave Antenna
Interferometric gravitational wave antennas are based on Michelson
interferometers whose sensitivity to small differential length changes has been
enhanced by adding multiple coupled optical resonators. The use of optical
cavities is essential for reaching the required sensitivity, but sets
challenges for the control system which must maintain the cavities near
resonance. The goal for the strain sensitivity of the Laser Interferometer
Gravitational-wave Observatory (LIGO) is 10^-21 rms, integrated over a 100 Hz
bandwidth centered at 150 Hz. We present the major design features of the LIGO
length and frequency sensing and control system which will hold the
differential length to within 5 10^-14 m of the operating point. We also
highlight the restrictions imposed by couplings of noise into the gravitational
wave readout signal and the required immunity against them.Comment: Presentation at ICALEPCS 2001, San Jose, November 2001, (WECT003), 3
page
Guaranteed Detection of a Minimal Supersymmetric Model Higgs Boson at Hadron Supercolliders
We demonstrate that expected efficiencies and purities for -tagging at
SSC/LHC detectors should allow detection of at least one of the Higgs bosons of
the Minimal Supersymmetric Model in t\anti t~Higgs production, with
Higgs\rta b\anti b decay, over a substantial range of supersymmetric
parameter space. In particular, with the addition of this mode to those
previously considered, there is no region of supersymmetric parameter space for
which {\it none} of the Higgs bosons of the model can be seen at the SSC/LHC.Comment: 9 pages, uses phyzzx.tex and tables.tex macros, full postscript file,
including embedded figures, available via anonymous ftp at ucdhep.ucdavis.edu
as [anonymous.gunion]hbb_susy.ps, preprint UCD-93-2
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