527 research outputs found
Analyzing Demand For Disposal And Recycling Services: A Systems Approach
Pricing municipal solid waste (MSW) services using a flat fee offers no incentive to conserve on disposal. This has prompted the use of unit pricing schemes, which should reduce disposal in accordance with demand theory and encourage alternatives such as recycling. Most studies estimate distinct demand equations for disposal and recycling, and none use a systems approach to simultaneous estimate them. To that end, this research estimates such a model, which also recognizes the endogeneity of policy variables. The results offer important policy insight and shed light on the effectiveness of unit pricing in reducing disposal and simultaneously encouraging recycling.
The Influence of Parkinson\u27s Disease Symptoms on Repetitive Toe Tapping at High and Low Frequencies.
People with Parkinson\u27s Disease have impairments in repetitive movement. However, no one has quantified repetitive toe-tapping performance at different rates in persons with PD. Position of the toe and EMG of the tibialias anterior and gastrocnemius were collected while participants tapped at 70 beats per minute and 140 beats per minute. Results revealed that participants had greater impairment at the higher rate. The results of this data will inform future studies on the impact of impairments in repetitive movements on larger motor tasks such as gait
The Hyperon-Nucleon Interaction Potential in the Bound State Soliton Model: The Case
We develop the formalism to study the hyperon-nucleon interaction potential
within the bound state approach to the SU(3) Skyrme model. The general
framework is illustrated by applying it to the diagonal potential.
The central, spin-spin and tensor components of this interaction are obtained
and compared with those derived using alternative schemes.Comment: source file, 4 ps figure
Gluon topology and the spin structure of the constituent quark
Gluon topology makes a potentially important contribution to the spin of the
constituent quark.Comment: 3 pages, LaTeX, talk at DIS99, Zeuthen, April 199
Synthetic Light Curves and Spectra from a Self-Consistent 2D Simulation of an Ultra-strippped Supernova
Spectroscopy is an important tool for providing insights into the structure
of core-collapse supernova explosions. We use the Monte Carlo radiative
transfer code ARTIS to compute synthetic spectra and light curves based on a
two-dimensional explosion model of an ultra-stripped supernova. These
calculations are designed both to identify observable fingerprints of
ultra-stripped supernovae and as a proof-of-principle for using synthetic
spectroscopy to constrain the nature of stripped-envelope supernovae more
broadly. We predict very characteristic spectral and photometric features for
our ultra-stripped explosion model, but find that these do not match observed
ultra-stripped supernova candidates like SN 2005ek. With a peak bolometric
luminosity of , a peak
magnitude of in R-band, and , the model is even fainter and evolves even faster than
SN 2005ek as the closest possible analogue in photometric properties. The
predicted spectra are extremely unusual. The most prominent features are Mg II
lines at 2,800 Angstrom and 4,500 Angstrom and the infrared Ca triplet at late
times. The Mg lines are sensitive to the multi-dimensional structure of the
model and are viewing-angle dependent. They disappear due to line blanketing by
Fe group elements in a spherically averaged model with additional microscopic
mixing. In future studies, multi-D radiative transfer calculations need to be
applied to a broader range of models to elucidate the nature of observed Type
Ib/c supernovae.Comment: 13 pages, 14 figures, submitted to MNRA
Dibaryons as axially symmetric skyrmions
Dibaryons configurations are studied in the framework of the bound state
soliton model. A generalized axially symmetric ansatz is used to determine the
soliton background. We show that once the constraints imposed by the symmetries
of the lowest energy torus configuration are satisfied all spurious states are
removed from the dibaryon spectrum. In particular, we show that the lowest
allowed state in the channel carries the quantum numbers of the H
particle. We find that, within our approximations, this particle is slightly
bound in the model. We discuss, however, that vacuum effects neglected in the
present calculation are very likely to unbind the H.Comment: 24 pages, LaTeX, TAN-FNT-93-12 (it replaces old version which was
truncated
Higher-Order Black-Hole Solutions in N=2 Supergravity and Calabi-Yau String Backgrounds
Based on special geometry, we consider corrections to N=2 extremal black-hole
solutions and their entropies originating from higher-order derivative terms in
N=2 supergravity. These corrections are described by a holomorphic function,
and the higher-order black-hole solutions can be expressed in terms of
symplectic Sp(2+2) vectors. We apply the formalism to N=2 type-IIA
Calabi-Yau string compactifications and compare our results to recent related
results in the literature.Comment: 12 pages, LaTeX; reference added; minor changes, note added, version
to appear in Phys. Lett.
Targeted Chemo-Sonodynamic Therapy Treatment of Breast Tumours Using Ultrasound Responsive Microbubbles Loaded with Paclitaxel, Doxorubicin and Rose Bengal.
Mastectomy is a common surgical treatment used in the management of breast cancer but has associated physical and psychological consequences for the patient. Breast conservation surgery (BCS) is an alternative to mastectomy but is only possible when the tumour is of an appropriate size. Neo-adjuvant chemotherapy has been successfully used to downstage tumours and increase the number of patients eligible for BCS. However, the chemotherapies used in this approach are non-targeted and often result in significant side effects to the patient. In this manuscript, we evaluate the potential of ultrasound targeted microbubble destruction (UTMD) to deliver Rose Bengal-mediated sonodynamic therapy (SDT) in combination with paclitaxel (PTX) and doxorubicin (Dox) chemotherapy as a potential treatment for breast cancer. Efficacy of the combined treatment was determined in a three-dimensional (3D) spheroid model of human breast cancer and in a murine model of the disease bearing subcutaneous MCF-7 tumours. The results demonstrated a significant reduction in both the cell viability of spheroids and tumour volume following treatment with the drug loaded microbubbles and ultrasound compared to targets treated with the drug loaded microbubbles alone or a Cremophor EL suspension of PTX and Dox. In addition, the weight of animals that received the microbubble treatment was unchanged throughout the study while a reduction of 12.1% was observed for animals treated with a Cremophor suspension of PTX/Dox. These results suggest that UTMD-mediated chemo-sonodynamic therapy is an efficacious and well tolerated approach for the treatment of breast cancer
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