606 research outputs found
Relative cluster entropy for power-law correlated sequences
We propose an information-theoretical measure, the \textit{relative cluster
entropy} , to discriminate among cluster partitions
characterised by probability distribution functions and . The measure is
illustrated with the clusters generated by pairs of fractional Brownian motions
with Hurst exponents and respectively. For subdiffusive, normal and
superdiffusive sequences, the relative entropy sensibly depends on the
difference between and . By using the \textit{minimum relative
entropy} principle, cluster sequences characterized by different correlation
degrees are distinguished and the optimal Hurst exponent is selected. As a case
study, real-world cluster partitions of market price series are compared to
those obtained from fully uncorrelated sequences (simple Browniam motions)
assumed as a model. The \textit{minimum relative cluster entropy} yields
optimal Hurst exponents , , and respectively for
the prices of DJIA, S\&P500, NASDAQ: a clear indication of non-markovianity.
Finally, we derive the analytical expression of the relative cluster entropy
and the outcomes are discussed for arbitrary pairs of power-laws probability
distribution functions of continuous random variables
Hunting in times of change: Uncovering indigenous strategies in the Colombian amazon using a role-playing game
Despite growing industrialization, the shift to a cash economy and natural resource overexploitation, indigenous people of the Amazon region hunt and trade wildlife in order to meet their livelihood requirements. Individual strategies, shaped by the hunters' values and expectations, are changing in response to the region's economic development, but they still face the contrasting challenges of poverty and overhunting. For conservation initiatives to be implemented effectively, it is crucial to take into account people's strategies with their underlying drivers and their adaptive capabilities within a transforming socio-economic environment. To uncover hunting strategies in the Colombian Amazon and their evolution under the current transition, we co-designed a role-playing game together with the local stakeholders. The game revolves around the tension between ecological sustainability and food securityâhunters' current main concern. It simulates the mosaic of activities that indigenous people perform in the wet and dry season, while also allowing for specific hunting strategies. Socio-economic conditions change while the game unfolds, opening up to emerging alternative potential scenarios suggested by the stakeholders themselves. Do hunters give up hunting when given the opportunity of an alternative income and protein source? Do institutional changes affect their livelihoods? We played the game between October and December 2016 with 39 playersâall of them huntersâfrom 9 different communities within the Ticoya reserve. Our results show that providing alternatives would decrease overall hunting effort, but impacts are not spatially homogenous. Legalizing trade could lead to overhunting except when market rules and competition come into place. When it comes to coupled human-nature systems, the best way forward to produce socially just and resilient conservation strategies might be to trigger an adaptive process of experiential learning and scenario exploration. The use of games as âboundary objectsâ can guide stakeholders through the process, eliciting the plurality of their strategies, their drivers and how outside change affects them
Reconciling taxonomy and phylogenetic inference: formalism and algorithms for describing discord and inferring taxonomic roots
Although taxonomy is often used informally to evaluate the results of
phylogenetic inference and find the root of phylogenetic trees, algorithmic
methods to do so are lacking. In this paper we formalize these procedures and
develop algorithms to solve the relevant problems. In particular, we introduce
a new algorithm that solves a "subcoloring" problem for expressing the
difference between the taxonomy and phylogeny at a given rank. This algorithm
improves upon the current best algorithm in terms of asymptotic complexity for
the parameter regime of interest; we also describe a branch-and-bound algorithm
that saves orders of magnitude in computation on real data sets. We also
develop a formalism and an algorithm for rooting phylogenetic trees according
to a taxonomy. All of these algorithms are implemented in freely-available
software.Comment: Version submitted to Algorithms for Molecular Biology. A number of
fixes from previous versio
A comparison of sacral neuromodulation vs. transvaginal electrical stimulation for the treatment of refractory overactive bladder: The impact on quality of life, body image, sexual function, and emotional well-being
Overactive bladder syndrome (OAB) is defined by the presence of urinary urgency, with or without urge incontinence, usually accompanied by an increase in urinary frequency and nocturia in the absence of urinary tract infections (UTI) or other diseases. The overall prevalence of OAB symptoms in the female population is reported to be 16.6% and increases with advancing age and menopause. The aetiology of OAB is not fully understood and is likely to affect a heterogeneous population of patients due to changes to their central and peripheral nervous systems. Although OAB is frequently associated with female sexual dysfunction (FSD), its real impact on sexual function in women has been evaluated only in a few studies. The first line of treatment for OAB includes behavioural modification and physical therapy, either as monotherapies or in combination. Many patients who have not had success in managing their symptoms with more conservative therapies may decide to resort to third-line treatments for refractory OAB. These treatments include neuromodulation therapies, particularly transvaginal electrical stimulation (TES) and sacral neuromodulation (SN). The aim of this short commentary is to provide an overview of the effectiveness of these treatments and of their impact on quality of life, body image, sexual function, and emotional well-being
Searches for the Violation of Pauli Exclusion Principle at LNGS in VIP(-2) experiment
The VIP (Violation of Pauli exclusion principle) experiment and its follow-up
experiment VIP-2 at the Laboratori Nazionali del Gran Sasso (LNGS) search for
X-rays from Cu atomic states that are prohibited by the Pauli Exclusion
Principle (PEP). The candidate events, if they exist, will originate from the
transition of a orbit electron to the ground state which is already
occupied by two electrons. The present limit on the probability for PEP
violation for electron is 4.7 set by the VIP experiment. With
upgraded detectors for high precision X-ray spectroscopy, the VIP-2 experiment
will improve the sensitivity by two orders of magnitude.Comment: 5 pages, 3 figures, 1 table. Conference proceedings for oral
presentation at TAUP 2015, Torin
High sensitivity tests of the Pauli Exclusion Principle with VIP2
The Pauli Exclusion Principle is one of the most fundamental rules of nature
and represents a pillar of modern physics. According to many observations the
Pauli Exclusion Principle must be extremely well fulfilled. Nevertheless,
numerous experimental investigations were performed to search for a small
violation of this principle. The VIP experiment at the Gran Sasso underground
laboratory searched for Pauli-forbidden X-ray transitions in copper atoms using
the Ramberg-Snow method and obtained the best limit so far. The follow-up
experiment VIP2 is designed to reach even higher sensitivity. It aims to
improve the limit by VIP by orders of magnitude. The experimental method,
comparison of different PEP tests based on different assumptions and the
developments for VIP2 are presented.Comment: 6 pages, 3 figures, Proceedings DISCRETE2014 Conferenc
Testing the Pauli Exclusion Principle for electrons at LNGS
High-precision experiments have been done to test the Pauli exclusion
principle (PEP) for electrons by searching for anomalous -series X-rays from
a Cu target supplied with electric current. With the highest sensitivity, the
VIP (VIolation of Pauli Exclusion Principle) experiment set an upper limit at
the level of for the probability that an external electron captured
by a Cu atom can make the transition from the 2 state to a 1 state
already occupied by two electrons. In a follow-up experiment at Gran Sasso, we
aim to increase the sensitivity by two orders of magnitude. We show proofs that
the proposed improvement factor is realistic based on the results from recent
performance tests of the detectors we did at Laboratori Nazionali di Frascati
(LNF).Comment: 8 pages, 5 figures, conference proceedings on TAUP 201
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