94 research outputs found
The critical earthquake concept applied to mine rockbursts with time-to-failure analysis
We report new tests of the critical earthquake concepts performed on
rockbursts in deep South African mines. We extend the concept of an optimal
time and space correlation region and test it on the eight main shocks of our
catalog provided by ISSI. In a first test, we use the simplest signature of
criticality in terms of a power law time-to-failure formula. Notwithstanding
the fact that the search for the optimal correlation size is performed with
this simple power law, we find evidence both for accelerated seismicity and for
the presence of logperiodic behavior with a prefered scaling factor close to 2.
We then propose a new algorithm based on a space and time smoothing procedure,
which is also intended to account for the finite range and time mechanical
interactions between events. This new algorithm provides a much more robust and
efficient construction of the optimal correlation region, which allows us the
use of the logperiodic formula directly in the search process. In this
preliminary work, we have only tested the new algorithm on the largest event on
the catalog. The result is of remarkable good quality with a dramatic
improvement in accuracy and robustness. This confirms the potential importance
of logperiodic signals. Our study opens the road for an efficient implemention
of a systematic testing procedure of real-time predictions.Comment: 22 pages, 32 figure
Dragon-kings: mechanisms, statistical methods and empirical evidence
This introductory article presents the special Discussion and Debate volume
"From black swans to dragon-kings, is there life beyond power laws?" published
in Eur. Phys. J. Special Topics in May 2012. We summarize and put in
perspective the contributions into three main themes: (i) mechanisms for
dragon-kings, (ii) detection of dragon-kings and statistical tests and (iii)
empirical evidence in a large variety of natural and social systems. Overall,
we are pleased to witness significant advances both in the introduction and
clarification of underlying mechanisms and in the development of novel
efficient tests that demonstrate clear evidence for the presence of
dragon-kings in many systems. However, this positive view should be balanced by
the fact that this remains a very delicate and difficult field, if only due to
the scarcity of data as well as the extraordinary important implications with
respect to hazard assessment, risk control and predictability.Comment: 20 page
Vector-borne and other pathogens of potential relevance disseminated by relocated cats
Large populations of unowned cats constitute an animal welfare, ecological, societal and public health issue worldwide. Their relocation and homing are currently carried out in many parts of the world with the intention of relieving suffering and social problems, while contributing to ethical and humane population control in these cat populations. An understanding of an individual cat’s lifestyle and disease status by veterinary team professionals and those working with cat charities can help to prevent severe cat stress and the spread of feline pathogens, especially vector-borne pathogens, which can be overlooked in cats. In this article, we discuss the issue of relocation and homing of unowned cats from a global perspective. We also review zoonotic and non-zoonotic infectious agents of cats and give a list of practical recommendations for veterinary team professionals dealing with homing cats. Finally, we present a consensus statement consolidated at the 15th Symposium of the Companion Vector-Borne Diseases (CVBD) World Forum in 2020, ultimately to help veterinary team professionals understand the problem and the role they have in helping to prevent and manage vector-borne and other pathogens in relocated cats
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