An algorithm to coordinate measurements using stochastic human mobility patterns in large-scale participatory sensing settings

Participatory sensing is a promising new low-cost approach for collecting environmental data. However, current large-scale environmental participatory sensing campaigns typically do not coordinate the measurements of participants, which can lead to gaps or redundancy in the collected data. While some work has considered this problem, it has made several unrealistic assumptions. In particular, it assumes that complete and accurate knowledge about the participants future movements is available and it does not consider constraints on the number of measurements a user is willing to take. To address these shortcomings, we develop a computationally-efficient coordination algorithm (Best-match) to suggest to users where and when to take measurements. Our algorithm exploits human mobility patterns, but explicitly considers the inherent uncertainty of these patterns. We empirically evaluate our algorithm on a real-world human mobility and air quality dataset and show that it outperforms the state-of-the-art greedy and pull-based proximity algorithms in dynamic environments

P and S wave travel time tomography of the SE Asia-Australia collision zone

© 2019 Elsevier B.V. The southeast (SE)Asia - Australia collision zone is one of the most tectonically active and seismogenic regions in the world. Here, we present new 3-D P- and S-wave velocity models of the crust and upper mantle by applying regional earthquake travel-time tomography to global catalogue data. We first re-locate earthquakes provided by the standard ISC-Reviewed and ISC-EHB catalogues using a non-linear oct-tree scheme. A machine learning algorithm that clusters earthquakes depending on their spatiotemporal density was then applied to significantly improve the consistency of travel-time picks. We used the Fast Marching Tomography software package to retrieve 3-D velocity and interface structures from starting 1-D velocity and Moho models. Synthetic resolution and sensitivity tests demonstrate that the final models are robust, with P-wave speed variations (~130 km horizontal resolution)generally recovered more robustly than S-wave speed variations (~220 km horizontal resolution). The retrieved crust and mantle anomalies offer a new perspective on the broad-scale tectonic setting and underlying mantle architecture of SE Asia. While we observe clear evidence of subducted slabs as high velocity anomalies penetrating into the mantle along the Sunda arc, Banda arc and Halmahera arc, we also see evidence for slab gaps or holes in the vicinity of east Java. In the Banda arc, we image the slab as a single curved subduction zone. Furthermore, a high-velocity region in the mantle lithosphere connects northern Australia with Timor and West Papua. The S-wave model shows broad-scale features similar to those of the P-wave model, with mantle earthquakes generally distributed within high-velocity slabs. The high velocity mantle connection between northern Australia and the eastern margin of the Sunda arc is also present in the S-wave model. While the S-wave model has a lower resolution than the P-wave model due to the availability of fewer paths, it nonetheless provides new and complementary insights into the structure of the upper mantle beneath southeast Asia

The dividend policy in Europe : the cases of the UK, Germany, France and Italy

This thesis attempts to provide a comparative and comprehensive understanding of corporate dividend policy in European Countries. I examine the dividend policy of the firm in the UK, Germany, France and Italy. The thesis is motivated by the importance of dividend policy theory in the area of finance, the mixed theoretical and empirical evidence, the predominately US based literature and by the financial, institutional and corporate governance differences between European countries. The thesis examines the "big three imperfections" of the dividend policy: taxation, asymmetric information and agency costs. The uniqueness of the thesis is its European character. The main argument is that differences in taxation and corporate governance systems between European countries can prove a useful tool for providing some answers to the dividend puzzle. With respect to dividend taxation systems the UK operates a partial imputation system while Germany, France and Italy operate full imputation systems. With respect to the corporate governance systems the UK is characterised as a market-based country while Germany, France and Italy are characterised as bank-based systems. In general results show that there are significant differences between dividend taxation systems in European countries that result in variations of the tax discrimination variable. In all countries ex-day returns are positive and significant suggesting that ex-day prices fall by less than the amount of dividends. Results confirm that in countries where the differential taxation between dividends and capital gains is high, ex-day returns are high. Also, I find that changes in the tax systems that affect taxes on dividend and/or capital gains alter significantly ex-day returns. Furthermore, the corporate governance differences between market-based and bank-based countries result in different levels of information asymmetries and/or agency conflicts. Results in all the countries show significant share price reaction on the dividend announcement days. Evidence provides support to the information content of dividend hypothesis. Moreover, I do not find evidence to reject the signalling hypothesis over the over investment hypothesis

Barcoding Genetically Distinct Plasmodium falciparum Strains for Comparative Assessment of Fitness and Antimalarial Drug Resistance

The repeated emergence of antimalarial drug resistance in Plasmodium falciparum, including to the current frontline antimalarial artemisinin, is a perennial problem for malaria control. Next-generation sequencing has greatly accelerated the identification of polymorphisms in resistance-associated genes but has also highlighted the need for more sensitive and accurate laboratory tools to profile current and future antimalarials and to quantify the impact of drug resistance acquisition on parasite fitness. The interplay of fitness and drug response is of fundamental importance in understanding why particular genetic backgrounds are better at driving the evolution of drug resistance in natural populations, but the impact of parasite fitness landscapes on the epidemiology of drug resistance has typically been laborious to accurately quantify in the lab, with assays being limited in accuracy and throughput. Here we present a scalable method to profile fitness and drug response of genetically distinct P. falciparum strains with well-described sensitivities to several antimalarials. We leverage CRISPR/Cas9 genome-editing and barcode sequencing to track unique barcodes integrated into a nonessential gene (pfrh3). We validate this approach in multiplex competitive growth assays of three strains with distinct geographical origins. Furthermore, we demonstrate that this method can be a powerful approach for tracking artemisinin response as it can identify an artemisinin resistant strain within a mix of multiple parasite lines, suggesting an approach for scaling the laborious ring-stage survival assay across libraries of barcoded parasite lines. Overall, we present a novel high-throughput method for multiplexed competitive growth assays to evaluate parasite fitness and drug response

The Direct Costs of Patients with Traumatic Brain Injury in an Intensive Care Unit (ICU) in Cyprus

Background: The traumatic brain injuries are one of the leading causes of morbidity and mortality in our country. But studies that relate to the cost of hospitalization in the Unit are very limited.Objectives: To microeconomically assess the direct costs of patients with traumatic brain injury in Nicosia Hospital.Methodology: We got a convenience sample of all patients (7) who were hospitalized from July to September 2010. (a) The age, duration of stay, severity of incident and costs of all therapeutic procedures were surveyed using descriptive statistics (b) Pearson chi-square was used to investigate correlations between variables. (c) Multivariate Regression Analysis was employed for theinvestigation of factors affecting the cost of treatment. Age, duration of hospitalization and the cost of individual treatments were considered as independent variables for the direct cost. All tests were considered to be significant at a 5% level. Analysis was carried out using SPSS 20.0.Results: The average cost of hospitalization of the patients with traumatic brain injury in the Unit was € 18,659.51 (€ 2,936.56-33,330.2) and SD € 11,191.11. The average number of days of hospitalization was 14.14 (4-34 days) and SD 10.81 days and the average age was 36 years (13-66 years) and SD 20.06 years. Older age was associated with a significant longer stay, p <0.01 and furthermore age and disease severity had statistically significant correlation p <0.001 with the total cost of hospitalization.Conclusions: The cost of hospitalization in the Unit was influenced by age, duration of stay and severity of the patient's status (Glasgow Coma Scale

Studying the Underlying Event in Drell-Yan and High Transverse Momentum Jet Production at the Tevatron

We study the underlying event in proton-antiproton collisions by examining the behavior of charged particles (transverse momentum pT > 0.5 GeV/c, pseudorapidity |\eta| < 1) produced in association with large transverse momentum jets (~2.2 fb-1) or with Drell-Yan lepton-pairs (~2.7 fb-1) in the Z-boson mass region (70 < M(pair) < 110 GeV/c2) as measured by CDF at 1.96 TeV center-of-mass energy. We use the direction of the lepton-pair (in Drell-Yan production) or the leading jet (in high-pT jet production) in each event to define three regions of \eta-\phi space; toward, away, and transverse, where \phi is the azimuthal scattering angle. For Drell-Yan production (excluding the leptons) both the toward and transverse regions are very sensitive to the underlying event. In high-pT jet production the transverse region is very sensitive to the underlying event and is separated into a MAX and MIN transverse region, which helps separate the hard component (initial and final-state radiation) from the beam-beam remnant and multiple parton interaction components of the scattering. The data are corrected to the particle level to remove detector effects and are then compared with several QCD Monte-Carlo models. The goal of this analysis is to provide data that can be used to test and improve the QCD Monte-Carlo models of the underlying event that are used to simulate hadron-hadron collisions.Comment: Submitted to Phys.Rev.

Shrinking a large dataset to identify variables associated with increased risk of Plasmodium falciparum infection in Western Kenya

Large datasets are often not amenable to analysis using traditional single-step approaches. Here, our general objective was to apply imputation techniques, principal component analysis (PCA), elastic net and generalized linear models to a large dataset in a systematic approach to extract the most meaningful predictors for a health outcome. We extracted predictors for Plasmodium falciparum infection, from a large covariate dataset while facing limited numbers of observations, using data from the People, Animals, and their Zoonoses (PAZ) project to demonstrate these techniques: data collected from 415 homesteads in western Kenya, contained over 1500 variables that describe the health, environment, and social factors of the humans, livestock, and the homesteads in which they reside. The wide, sparse dataset was simplified to 42 predictors of P. falciparum malaria infection and wealth rankings were produced for all homesteads. The 42 predictors make biological sense and are supported by previous studies. This systematic data-mining approach we used would make many large datasets more manageable and informative for decision-making processes and health policy prioritization

Study of CP violation in Dalitz-plot analyses of B0 --> K+K-KS, B+ --> K+K-K+, and B+ --> KSKSK+

We perform amplitude analyses of the decays $B^0 \to K^+K^-K^0_S$, $B^+ \rightarrow K^+K^-K^+$, and $B^+ \to K^0_S K^0_S K^+$, and measure CP-violating parameters and partial branching fractions. The results are based on a data sample of approximately $470\times 10^6$ $B\bar{B}$ decays, collected with the BABAR detector at the PEP-II asymmetric-energy $B$ factory at the SLAC National Accelerator Laboratory. For $B^+ \to K^+K^-K^+$, we find a direct CP asymmetry in $B^+ \to \phi(1020)K^+$ of $A_{CP}= (12.8\pm 4.4 \pm 1.3)$, which differs from zero by $2.8 \sigma$. For $B^0 \to K^+K^-K^0_S$, we measure the CP-violating phase $\beta_{\rm eff} (\phi(1020)K^0_S) = (21\pm 6 \pm 2)^\circ$. For $B^+ \to K^0_S K^0_S K^+$, we measure an overall direct CP asymmetry of $A_{CP} = (4 ^{+4}_{-5} \pm 2)$. We also perform an angular-moment analysis of the three channels, and determine that the $f_X(1500)$ state can be described well by the sum of the resonances $f_0(1500)$, $f_2^{\prime}(1525)$, and $f_0(1710)$.Comment: 35 pages, 68 postscript figures. v3 - minor modifications to agree with published versio