1,316 research outputs found
Effects of landscape gradients on wetland vegetation communities: information for large-scale restoration
Projects of the scope of the restoration of the Florida Everglades require substantial
information regarding ecological mechanisms, and these are often poorly understood. We provide critical
base knowledge for Everglades restoration by characterizing the existing vegetation communities of an
Everglades remnant, describing how present and historic hydrology affect wetland vegetation community
composition, and documenting change from communities described in previous studies. Vegetation
biomass samples were collected along transects across Water Conservation Area 3A South (3AS)
A Novel Scheme to Search for Fractional Charge Particles in Low Energy Accelerator Experiments
In the Standard Model of particle physics, the quarks and anti-quarks have
fractional charge equal to or of the electron's charge. There
has been a large number of experiments searching for fractional charge,
isolatable, elementary particles using a variety of methods, including
collisions using dE/dx ionization energy loss measurements, but no evidence has
been found to confirm existence of free fractional charge particles, which
leads to the quark confinement theory. In this paper, a proposal to search for
this kind particles is presented, which is based on the conservation law of
four-momentum. Thanks to the CLEOc and BESIII detectors' large coverage, good
particle identification, precision measurements of tracks' momenta and their
large recorded data samples, these features make the scheme feasible in
practice. The advantage of the scheme is independent of any theoretical models
and sensitive for a small fraction of the quarks transitioning to the
unconfinement phase from the confinement phase.Comment: 9 page
The Active Traveling Wave in the Cochlea
A sound stimulus entering the inner ear excites a deformation of the basilar
membrane which travels along the cochlea towards the apex. It is well
established that this wave-like disturbance is amplified by an active system.
Recently, it has been proposed that the active system consists of a set of
self-tuned critical oscillators which automatically operate at an oscillatory
instability. Here, we show how the concepts of a traveling wave and of
self-tuned critical oscillators can be combined to describe the nonlinear wave
in the cochlea.Comment: 5 pages, 2 figure
Benchmarking with Spine Tango: potentials and pitfalls
The newly released online statistics function of Spine Tango allows comparison of own data against the aggregated results of the data pool that all other participants generate. This comparison can be considered a very simple way of benchmarking, which means that the quality of what one organization does is compared with other similar organizations. The goal is to make changes towards better practice if benchmarking shows inferior results compared with the pool. There are, however, pitfalls in this simplified way of comparing data that can result in confounding. This means that important influential factors can make results appear better or worse than they are in reality and these factors can only be identified and neutralized in a multiple regression analysis performed by a statistical expert. Comparing input variables, confounding is less of a problem than comparing outcome variables. Therefore, the potentials and limitations of automated online comparisons need to be considered when interpreting the results of the benchmarking procedur
Computer aided diagnosis for cardiovascular diseases based on ECG signals : a survey
The interpretation of Electroencephalography (ECG) signals is difficult, because even subtle changes in the waveform can indicate a serious heart disease. Furthermore, these waveform changes might not be present all the time. As a consequence, it takes years of training for a medical practitioner to become an expert in ECG-based cardiovascular disease diagnosis. That training is a major investment in a specific skill. Even with expert ability, the signal interpretation takes time. In addition, human interpretation of ECG signals causes interoperator and intraoperator variability. ECG-based Computer-Aided Diagnosis (CAD) holds the promise of improving the diagnosis accuracy and reducing the cost. The same ECG signal will result in the same diagnosis support regardless of time and place. This paper introduces both the techniques used to realize the CAD functionality and the methods used to assess the established functionality. This survey aims to instill trust in CAD of cardiovascular diseases using ECG signals by introducing both a conceptional overview of the system and the necessary assessment method
The Semiglades: The Collision of Restoration, Social Values, and the Ecosystem Concept
Abstract Defining success targets in restoration and how social values affect them are two commonly discussed issues in restoration today. We believe that how success is commonly defined-with vague terms such as "healthy ecosystem" or cited as a return to a previous, historic state-needs to be reevaluated. With the increasing number of novel ecosystems, there is an increasing conflict between the ecosystem concept, social values, and restoration. This arises from the fact that ecosystems are defined by the values of the scientists describing them, necessarily constraining the ecosystem to a generally static concept. It is not directly the concept, but how it is perceived through our filter of social values that represses the creativity and innovation needed in restoration today. Within restoration, we feel that the ecosystem concept does a disservice by ignoring the increasing number of novel systems, and that hinders real progress in a time when hesitation can be costly. To best illustrate this, we offer the example of restoration of the Florida Everglades and how it has become a novel system in pattern and process. We suggest renaming the Everglades "The Semiglades" in hopes of opening a dialog to expose social/ecosystem biases and include novel landscapes in management and planning
Production, Collection and Utilization of Very Long-Lived Heavy Charged Leptons
If a fourth generation of leptons exists, both the neutrino and its charged
partner must be heavier than 45 GeV. We suppose that the neutrino is the
heavier of the two, and that a global or discrete symmetry prohibits
intergenerational mixing. In that case, non-renormalizable Planck scale
interactions will induce a very small mixing; dimension five interactions will
lead to a lifetime for the heavy charged lepton of years. Production
of such particles is discussed, and it is shown that a few thousands can be
produced and collected at a linear collider. The possible uses of these heavy
leptons is also briefly discussed.Comment: 9 pages Late
Isoscalar-isovector mass splittings in excited mesons
Mass splittings between the isovector and isoscalar members of meson nonets
arise in part from hadronic loop diagrams which violate the Okubo-Zweig-Iizuka
rule.
Using a model for these loop processes which works qualitatively well in the
established nonets, I tabulate predictions for the splittings and associated
isoscalar mixing angles in the remaining nonets below about 2.5 GeV, and
explain some of their systematic features.
The results for excited vector mesons compare favorably with experiment.Comment: 8 RevTeX pages, including 1 LaTeX figure.
CMU-HEP93-23/DOE-ER-40682-4
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