728 research outputs found
The natural resources of Carpinteria Marsh: their status and future
The purpose of this report is: 1) to document the natural resources of Carpinteria Marsh, 2) outline the uses those resources receive, 3) enumerate the problems and conflicts of use that affect those resources, and 4) recommend measures that will protect and enhance the marsh and its resources. It is intended as a guide for citizens, planners and administrators of all private and public entities interested in the status and future of the marsh.
This report has been prepared under contract to and fully funded by the Office of Biological Services of the U.S. Fish and Wildlife Service. The goals and purpose of this federal office are to review the impact on fish and wildlife resources of land, mineral and water development practices, such as offshore oil and gas exploration, development and
production; construction of inshore pipeline canals and refineries; power plant construction/operation and urban development. This report, and five other southern California reports, covering Agua Hedionda (San Diego County), Anaheim Bay-Huntington Harbor (Orange County), Mugu Lagoon
(Ventura County), the Northern Santa Barbara County Coastal Wetlands and the Nipomo Dunes and Wetlands (San Luis Obispo County), are scheduled to be part of the Department's "Coastal Wetland Series" that includes reports
on the natural resources of Upper Newport Bay (Orange County), Goleta Slough (Santa Barbara county), Bolinas Lagoon (Marin County), Elkhorn Slough (Monterey County), San Diego Bay and Los Penasquitos Lagoon (San Diego County), Morro Bay (San Luis Obispo County), Humboldt Bay and
the Eel River Delta (Humboldt County), Lake Earl and the Smith River Delta (Del Norte County) and Bodega Harbor (Sonoma County). (103pp.
IMPETUS: Implementing HELP in the Upper Ouémé basin
Regional climate models that take into account land-use changes indicate that in the future, a general decrease in rainfall, together with prominent surface heating, can be expected for sub-Saharan Africa and the region north of the Sahara until 2050. Due to high population growth, land use changes rapidly and influences water availability and water demand. In this context, the research project IMPETUS (‘An Integrated Approach to the Efficient Management of Scarce Water Resources in West Africa’) offers a range of options for sustainable management of different components of the hydrological cycle. Target areas are the Ouémé basin in Benin and the Drâa catchment in Morocco. This paper concentrates on the Ouémé basin.Based on plausible scenarios of future economic, demographic, and climate developments, the effects of land use, land cover change, climate change, and demographic development on water availability and water demand are quantified. Scenarios of future water availability and water demand for the Upper Ouémé (Benin) catchment are discussed. To calculate water availability, the output of a regional climate model was linked to a hydrological model that also considered land use change calculated by a cellular automata model. Future water requirements were computed by linking population growth and per capita water demand, which was derived from a regional survey. Furthermore, the need for water for animal husbandry was considered.The results of the ‘business as usual’ scenario, combined with IPCC Scenarios A1B and B2, through the year 2045 are presented. The results reveal a significant decrease in water availability (surface water and groundwater) due to a decrease in rainfall and a significant increase in evapotranspiration. Although total water consumption increases strongly, it represents only about 0.5% of the yearly renewable water resources. Comparing these data, it may be concluded that water scarcity is not a problem in Benin. However, water availability shows high temporal variations due to the rainy and the dry seasons. Even if physical water scarcity is not a limiting factor, access to water in some parts of the catchment is limited due to economic factors.Keywords: HELP, IMPETUS, Benin, Morocco, Decision Support Systems, global change, information systems, loosely coupled models, problem clusters, scenario development, water availability, water deman
Self-Similar Log-Periodic Structures in Western Stock Markets from 2000
The presence of log-periodic structures before and after stock market crashes
is considered to be an imprint of an intrinsic discrete scale invariance (DSI)
in this complex system. The fractal framework of the theory leaves open the
possibility of observing self-similar log-periodic structures at different time
scales. In the present work we analyze the daily closures of three of the most
important indices worldwide since 2000: the DAX for Germany and the Nasdaq100
and the S&P500 for the United States. The qualitative behaviour of these
different markets is similar during the temporal frame studied. Evidence is
found for decelerating log-periodic oscillations of duration about two years
and starting in September 2000. Moreover, a nested sub-structure starting in
May 2002 is revealed, bringing more evidence to support the hypothesis of
self-similar, log-periodic behavior. Ongoing log-periodic oscillations are also
revealed. A Lomb analysis over the aforementioned periods indicates a
preferential scaling factor . Higher order harmonics are also
present. The spectral pattern of the data has been found to be similar to that
of a Weierstrass-type function, used as a prototype of a log-periodic fractal
function.Comment: 17 pages, 14 figures. International Journal of Modern Physics C, in
pres
Opportunities to Intercalibrate Radiometric Sensors From International Space Station
Highly accurate measurements of Earth's thermal infrared and reflected solar radiation are required for detecting and predicting long-term climate change. We consider the concept of using the International Space Station to test instruments and techniques that would eventually be used on a dedicated mission such as the Climate Absolute Radiance and Refractivity Observatory. In particular, a quantitative investigation is performed to determine whether it is possible to use measurements obtained with a highly accurate reflected solar radiation spectrometer to calibrate similar, less accurate instruments in other low Earth orbits. Estimates of numbers of samples useful for intercalibration are made with the aid of year-long simulations of orbital motion. We conclude that the International Space Station orbit is ideally suited for the purpose of intercalibration
On the role of the effective interaction in quasi-elastic electron scattering calculations
The role played by the effective residual interaction in the transverse
nuclear response for quasi-free electron scattering is discussed. The analysis
is done by comparing different calculations performed in the Random--Phase
Approximation and Ring Approximation frameworks. The importance of the exchange
terms in this energy region is investigated and the changes on the nuclear
responses due to the modification of the interaction are evaluated. The
calculated quasi-elastic responses show clear indication of their sensibility
to the details of the interaction and this imposes the necessity of a more
careful study of the role of the different channels of the interaction in this
excitation region.Comment: 16 pages, 4 Postscript figure
Extended Theory of Finite Fermi Systems: Application to the collective and non-collective E1 strength in Pb
The Extended Theory of Finite Fermi Systems is based on the conventional
Landau-Migdal theory and includes the coupling to the low-lying phonons in a
consistent way. The phonons give rise to a fragmentation of the single-particle
strength and to a compression of the single-particle spectrum. Both effects are
crucial for a quantitative understanding of nuclear structure properties. We
demonstrate the effects on the electric dipole states in Pb (which
possesses 50% more neutrons then protons) where we calculated the low-lying
non-collective spectrum as well as the high-lying collective resonances. Below
8 MeV, where one expects the so called isovector pygmy resonances, we also find
a strong admixture of isoscalar strength that comes from the coupling to the
high-lying isoscalar electric dipole resonance, which we obtain at about 22
MeV. The transition density of this resonance is very similar to the breathing
mode, which we also calculated. We shall show that the extended theory is the
correct approach for self-consistent calculations, where one starts with
effective Lagrangians and effective Hamiltonians, respectively, if one wishes
to describe simultaneously collective and non-collective properties of the
nuclear spectrum. In all cases for which experimental data exist the agreement
with the present theory results is good.Comment: 21 figures corrected typos in author fiel
Nonperturbative versus perturbative effects in generalized parton distributions
Generalized parton distributions (GPDs) are studied at the hadronic
(nonperturbative) scale within different assumptions based on a relativistic
constituent quark model. In particular, by means of a meson-cloud model we
investigate the role of nonperturbative antiquark degrees of freedom and the
valence quark contribution. A QCD evolution of the obtained GPDs is used to add
perturbative effects and to investigate the GPDs' sensitivity to the
nonperturbative ingredients of the calculation at larger (experimental) scale.Comment: 17 pages, 10 figures; submitted to Phys. Rev.
The components of empirical multifractality in financial returns
We perform a systematic investigation on the components of the empirical
multifractality of financial returns using the daily data of Dow Jones
Industrial Average from 26 May 1896 to 27 April 2007 as an example. The
temporal structure and fat-tailed distribution of the returns are considered as
possible influence factors. The multifractal spectrum of the original return
series is compared with those of four kinds of surrogate data: (1) shuffled
data that contain no temporal correlation but have the same distribution, (2)
surrogate data in which any nonlinear correlation is removed but the
distribution and linear correlation are preserved, (3) surrogate data in which
large positive and negative returns are replaced with small values, and (4)
surrogate data generated from alternative fat-tailed distributions with the
temporal correlation preserved. We find that all these factors have influence
on the multifractal spectrum. We also find that the temporal structure (linear
or nonlinear) has minor impact on the singularity width of the
multifractal spectrum while the fat tails have major impact on ,
which confirms the earlier results. In addition, the linear correlation is
found to have only a horizontal translation effect on the multifractal spectrum
in which the distance is approximately equal to the difference between its DFA
scaling exponent and 0.5. Our method can also be applied to other financial or
physical variables and other multifractal formalisms.Comment: 6 epl page
Pion-nucleon scattering in a meson-exchange model
The pi-N interaction is studied within a meson-exchange model and in a
coupled-channels approach which includes the channels pi-N, eta-N, as well as
three effective pi-pi-N channels namely rho-N, pi-Delta, and sigma-N. Starting
out from an earlier model of the Julich group systematic improvements in the
dynamics and in some technical aspects are introduced. With the new model an
excellent quantitative reproduction of the pi-N phase shifts and inelasticity
parameters in the energy region up to 1.9 GeV and for total angular momenta J
leq 3/2 is achieved. Simultaneously, good agreement with data for the total and
differential pi-N -> eta-N transition cross sections is obtained. The
connection of the pi_N dynamics in the S_{11} partial wave with the reaction
pi-N -> eta-N is discussed.Comment: 32 pages, 9 figure
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