12,734 research outputs found
Does Harboring Terrorists Have Economic Costs?
The literature on conflict and terrorism has paid little attention to the economic costs of terrorism for the perpetrators of terror attacks. Our research fills that gap by examining the economic costs of harboring suicide terror attacks. We combine data on Palestinian suicide terrorists with data from the Palestinian Labor Force Survey, to identify and quantify the impact of a successful attack on unemployment and wages. We find robust evidence that terror attacks have important economic costs. They cause a significant increase in unemployment and a significant decrease in wages and on the number of Palestinians working in Israel. Importantly, these effects are persistent and last for at least six months after the attack.
Do Poor Economic Conditions Affect Terrorism?
While the existing empirical literature shows that poverty and economic conditions are not correlated with the quantity of terror, theory predicts that poverty and poor economic conditions may affect the quality of terror. Poor economic conditions may lead more able individuals to participate in terror attacks, allowing terror organizations to send betterqualified terrorists to more complex, high-impact terror missions. Using data on Palestinian suicideterrorists, we provide evidence of the correlation between economic conditions, the characteristics of suicide terrorists, and the targets they attack.
Document Retrieval on Repetitive Collections
Document retrieval aims at finding the most important documents where a
pattern appears in a collection of strings. Traditional pattern-matching
techniques yield brute-force document retrieval solutions, which has motivated
the research on tailored indexes that offer near-optimal performance. However,
an experimental study establishing which alternatives are actually better than
brute force, and which perform best depending on the collection
characteristics, has not been carried out. In this paper we address this
shortcoming by exploring the relationship between the nature of the underlying
collection and the performance of current methods. Via extensive experiments we
show that established solutions are often beaten in practice by brute-force
alternatives. We also design new methods that offer superior time/space
trade-offs, particularly on repetitive collections.Comment: Accepted to ESA 2014. Implementation and experiments at
http://www.cs.helsinki.fi/group/suds/rlcsa
Improved ESP-index: a practical self-index for highly repetitive texts
While several self-indexes for highly repetitive texts exist, developing a
practical self-index applicable to real world repetitive texts remains a
challenge. ESP-index is a grammar-based self-index on the notion of
edit-sensitive parsing (ESP), an efficient parsing algorithm that guarantees
upper bounds of parsing discrepancies between different appearances of the same
subtexts in a text. Although ESP-index performs efficient top-down searches of
query texts, it has a serious issue on binary searches for finding appearances
of variables for a query text, which resulted in slowing down the query
searches. We present an improved ESP-index (ESP-index-I) by leveraging the idea
behind succinct data structures for large alphabets. While ESP-index-I keeps
the same types of efficiencies as ESP-index about the top-down searches, it
avoid the binary searches using fast rank/select operations. We experimentally
test ESP-index-I on the ability to search query texts and extract subtexts from
real world repetitive texts on a large-scale, and we show that ESP-index-I
performs better that other possible approaches.Comment: This is the full version of a proceeding accepted to the 11th
International Symposium on Experimental Algorithms (SEA2014
Online Self-Indexed Grammar Compression
Although several grammar-based self-indexes have been proposed thus far,
their applicability is limited to offline settings where whole input texts are
prepared, thus requiring to rebuild index structures for given additional
inputs, which is often the case in the big data era. In this paper, we present
the first online self-indexed grammar compression named OESP-index that can
gradually build the index structure by reading input characters one-by-one.
Such a property is another advantage which enables saving a working space for
construction, because we do not need to store input texts in memory. We
experimentally test OESP-index on the ability to build index structures and
search query texts, and we show OESP-index's efficiency, especially
space-efficiency for building index structures.Comment: To appear in the Proceedings of the 22nd edition of the International
Symposium on String Processing and Information Retrieval (SPIRE2015
Perturbed angular correlation study of a haptenic molecule
The angular correlation of the 173-247 keV gamma-ray cascade after the electron-capture decay of (111)In is strongly perturbed when the I-p-nitrophenylethylenediaminetetraacetate chelate of (111)In(3+) is added to a solution containing rabbit antibody to dinitrophenyl groups. The radioactive chelate can be displaced by the addition of dinitrophenyllysine or unlabeled chelate. The average association constant between the antibody and the labeled chelate has been estimated from perturbed angular correlation measurements; this value is compared to the results of equilibrium dialysis. These experiments provide good evidence that information concerning macromolecular behavior can be obtained from perturbed angular correlation experiments that use chemically specific labels
On the effect of rotation on magnetohydrodynamic turbulence at high magnetic Reynolds number
This article is focused on the dynamics of a rotating electrically conducting
fluid in a turbulent state. As inside the Earth's core or in various industrial
processes, a flow is altered by the presence of both background rotation and a
large scale magnetic field. In this context, we present a set of 3D direct
numerical simulations of incompressible decaying turbulence. We focus on
parameters similar to the ones encountered in geophysical and astrophysical
flows, so that the Rossby number is small, the interaction parameter is large,
but the Elsasser number, defining the ratio between Coriolis and Lorentz
forces, is about unity. These simulations allow to quantify the effect of
rotation and thus inertial waves on the growth of magnetic fluctuations due to
Alfv\'en waves. Rotation prevents the occurrence of equipartition between
kinetic and magnetic energies, with a reduction of magnetic energy at
decreasing Elsasser number {\Lambda}. It also causes a decrease of energy
transfer mediated by cubic correlations. In terms of flow structure, a decrease
of {\Lambda} corresponds to an increase in the misalignment of velocity and
magnetic field.Comment: 18 pages, 12 figure
Efficacy of an eradication protocol in case of Pseudomonas aeruginosa primo-infections in children with cystic fibrosis
Introduction: Patients with cystic fibrosis (CF) are more susceptible to pathogens like P. aeruginosa (PA). PA primo-Ââinfections require particular attention, as with failure in eradication, there is accelerated lung deterioration. The main aim of this study is to assess the rate of PA eradication according to our particular protocol with inhaled tobramycin and oral ciprofloxacin, as there is no consensus in the literature on what eradication protocol the best is.
Methods: Retrospective single centre study with data analysis from June 1st 2007 to June 1st
2011 of patients who had primo-Ââinfections exclusively treated by 3 x 28 days of inhaled tobramycin and oral ciprofloxacin for the first and last 21 days. Success in eradication is defined by â„ 3 negative bacteriologies for 6 months after the beginning of the protocol. If â„ 1 bacteriology is positive, we consider the eradication as a failure.
Results: Out of 41 patients, 18 were included in our analysis. 7 girls (38.9%) and 11 boys (61.1%) followed the eradication protocol. Boys had 12 primo-Ââinfections and girls had 8. Among these 20 primo-Ââinfections, 16 (80%) had an all-Ââoverall success in eradication and 4 (20%) a failure. No significant statistical difference for age between these groups (t-Ââtest = 0.07, p = 0.94), neither for FEV1% (t-Ââtest = 0.96, p = 0.41) nor BMI (t-Ââtest = 1.35, p = 0.27).
Rate of success was 100% for girls and 66.6% for boys.
Conclusion: Our protocol succeeded in an overall eradication rate of 80%, without statistical significant impact on FEV1 % and BMI values. However, there is a sex difference with eradication rates in girls (100%) and boys (66.6%). A sex difference has not yet been reported in the literature. This should be evaluated in further studies
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