Hausdorff clustering of financial time series

A clustering procedure, based on the Hausdorff distance, is introduced and tested on the financial time series of the Dow Jones Industrial Average (DJIA) index.Comment: 9 pages, 3 figure

Sustainable Recycling of Insoluble Rust Waste for the Synthesis of Iron-Containing Perovskite-Type Catalysts

Insoluble rust waste from the scraping of rusted iron-containing materials represents a cheap, eco-friendly, and available source of iron. LaFeO3 perovskite-type powders were successfully prepared by solution combustion synthesis using rust waste from an electricity transmission tower manufacturer. Solution combustion synthesis enabled introduction of this insoluble iron precursor directly into the final product, bypassing complex extraction procedures. Catalytic activity in the propylene oxidation of the waste-derived LaFeO3 with stoichiometric Fe/La ratio was almost identical to the commercial iron nitrate-derived LaFeO3 , thus demonstrating the viability of this recycling solution. The amount of waste iron precursor was varied and its effect on the powder properties was investigated. A lesser stoichiometric amount of precursor produced a LaFeO3 -La2O3 binary system, whereas a higher stoichiometric amount led to a LaFeO3 -Fe2O3 binary system. Catalytic activity of iron-rich compositions in the propylene oxidation was only slightly lower than the stoichiometric one, whereas iron-poor compositions were much less active. This eco-friendly methodology can be easily extended to other iron perovskites with different chemical compositions and to other iron-containing compounds

Effect of Antiretroviral Therapy on Apoptosis Markers and Morphology in Peripheral Lymph Nodes of HIV-Infected Individuals

Background:: CD4+ T cell depletion and destruction and the involution of the lymphoid tissue are hallmarks of HIV infection. Although the underlying mechanisms are still unclear, apoptosis appears to play a central role. The objective of this study was to investigate the effect of antiretroviral therapy on the lymph node tissue, particularly with respect to morphology and apoptosis. Patients and Methods:: Between 1997 and 1999, two inguinal lymph nodes were excised from 31 previously untreated individuals who were in an early stage of HIV infection, the first one prior to treatment and the second after 16 to 20 months of treatment. Paraffin sections were investigated for lymph node architecture, distribution of cellular and viral markers, apoptosis, and expression of apoptotic key molecules which indirectly reflect apoptotic processes. Results:: After 16-20 months of antiretroviral therapy, a significant decrease in highly activated HIV-driven immune response was observed in the lymph node tissue as a marked reduction in follicular hyperplasia, a normalization of the follicular dendritic cell network, a significant increase in the number of CD4+ T cells, and a significant decrease in the number of CD8+ T cells. The expression of several proapoptotic (Fas, TRAIL, and active caspase 3) and antiapoptotic (Bcl-2 and IL-7Rα) molecules that were reconstituted in the tissues during therapy resembled their expression in lymph nodes of HIV-negative individuals. Limitations of the study are (a) the lack of untreated patients in the late stages, (b) for ethical reasons, the lack of a control group with untreated patients, and (c) for methodological reasons, the restriction of sequential measurements of apotpotic markers to one-third of the patients. Conclusion:: Antiretroviral therapy initiated in the early stages in HIV infection may halt the irreversible destruction of the lymph node tissue and may partially normalize apoptotic processe

Numerical simulation and experimental validation of fatigue behavior of wood-glass fiber composite T joint

In this paper, a numerical FE model is developed with ANSYS and validated by experimental tests to identify possible damage locations and fatigue breakage in different wood-glass fiber composite T-joints for marine applications. Both static and fatigue tests in three-point bending configuration have been performe

22Ne and 23Na ejecta from intermediate-mass stars: The impact of the new LUNA rate for 22Ne(p,gamma)23Na

We investigate the impact of the new LUNA rate for the nuclear reaction $^{22}$Ne$(p,\gamma)^{23}$Na on the chemical ejecta of intermediate-mass stars, with particular focus on the thermally-pulsing asymptotic giant branch (TP-AGB) stars that experience hot-bottom burning. To this aim we use the PARSEC and COLIBRI codes to compute the complete evolution, from the pre-main sequence up to the termination of the TP-AGB phase, of a set of stellar models with initial masses in the range $3.0\,M_{\odot} - 6.0\,M_{\odot}$, and metallicities $Z_{\rm i}=0.0005$, $Z_{\rm i}=0.006$, and $Z_{\rm i} = 0.014$. We find that the new LUNA measures have much reduced the nuclear uncertainties of the $^{22}$Ne and $^{23}$Na AGB ejecta, which drop from factors of $\simeq 10$ to only a factor of few for the lowest metallicity models. Relying on the most recent estimations for the destruction rate of $^{23}$Na, the uncertainties that still affect the $^{22}$Ne and $^{23}$Na AGB ejecta are mainly dominated by evolutionary aspects (efficiency of mass-loss, third dredge-up, convection). Finally, we discuss how the LUNA results impact on the hypothesis that invokes massive AGB stars as the main agents of the observed O-Na anti-correlation in Galactic globular clusters. We derive quantitative indications on the efficiencies of key physical processes (mass loss, third dredge-up, sodium destruction) in order to simultaneously reproduce both the Na-rich, O-poor extreme of the anti-correlation, and the observational constraints on the CNO abundance. Results for the corresponding chemical ejecta are made publicly available

Modeling viral coevolution: HIV multi-clonal persistence and competition dynamics

The coexistence of different viral strains (quasispecies) within the same host are nowadays observed for a growing number of viruses, most notably HIV, Marburg and Ebola, but the conditions for the formation and survival of new strains have not yet been understood. We present a model of HIV quasispecies competition, that describes the conditions of viral quasispecies coexistence under different immune system conditions. Our model incorporates both T and B cells responses, and we show that the role of B cells is important and additive to that of T cells. Simulations of coinfection (simultaneous infection) and superinfection (delayed secondary infection) scenarios in the early stages (days) and in the late stages of the infection (years) are in agreement with emerging molecular biology findings. The immune response induces a competition among similar phenotypes, leading to differentiation (quasi-speciation), escape dynamics and complex oscillations of viral strain abundance. We found that the quasispecies dynamics after superinfection or coinfection has time scales of several months and becomes even slower when the immune system response is weak. Our model represents a general framework to study the speed and distribution of HIV quasispecies during disease progression, vaccination and therapy.Comment: 20 pages, 10 figure

Performance of HPGe Detectors in High Magnetic Fields

A new generation of high-resolution hypernuclear gamma$-spectroscopy experiments with high-purity germanium detectors (HPGe) are presently designed at the FINUDA spectrometer at DAPhiNE, the Frascati phi-factory, and at PANDA, the antiproton proton hadron spectrometer at the future FAIR facility. Both, the FINUDA and PANDA spectrometers are built around the target region covering a large solid angle. To maximise the detection efficiency the HPGe detectors have to be located near the target, and therefore they have to be operated in strong magnetic fields B ~ 1 T. The performance of HPGe detectors in such an environment has not been well investigated so far. In the present work VEGA and EUROBALL Cluster HPGe detectors were tested in the field provided by the ALADiN magnet at GSI. No significant degradation of the energy resolution was found, and a change in the rise time distribution of the pulses from preamplifiers was observed. A correlation between rise time and pulse height was observed and is used to correct the measured energy, recovering the energy resolution almost completely. Moreover, no problems in the electronics due to the magnetic field were observed.Comment: submitted to Nucl. Instrum. Meth. Phys. Res. A, LaTeX, 19 pages, 9 figure

New detectors for the kaon and hypernuclear experiments with KaoS at MAMI and with PANDA at GSI

The KaoS spectrometer at the Mainz Microtron MAMI, Germany, is perceived as the ideal candidate for a dedicated spectrometer in kaon and hypernuclei electroproduction. KaoS will be equipped with new read-out electronics, a completely new focal plane detector package consisting of scintillating fibres, and a new trigger system. First prototypes of the fibre detectors and the associated new front-end electronics are shown in this contribution. The Mainz hypernuclei research program will complement the hypernuclear experiments at the planned FAIR facility at GSI, Germany. At the proposed antiproton storage ring the spectroscopy of double Lambda hypernuclei is one of the four main topics which will be addressed by the PANDA Collaboration. The experiments require the operation of high purity germanium (HPGe) detectors in high magnetic fields (B= 1T) in the presence of a large hadronic background. The performance of high resolution Ge detectors in such an environment has been investigated.Comment: Presentation at International Symposium on the Development of Detectors for Particle, Astroparticle and Synchrotron Radiation Experiments, Stanford, Ca (SNIC06), 6 pages, LaTeX, 11 eps figure