880 research outputs found
Two particle correlations inside one jet at "Modified Leading Logarithmic Approximation" of Quantum Chromodynamics; I: exact solution of the evolution equations at small x
We discuss correlations between two particles in jets at high energy
colliders and exactly solve the MLLA evolution equations in the small x limit.
We thus extend the Fong-Webber analysis to the region away from the hump of the
single inclusive energy spectrum. We give our results for LEP, Tevatron and LHC
energies, and compare with existing experimental data.Comment: LaTeX, 49 pages, 57 .eps figures + one log
MUMAL: multivariate analysis in shotgun proteomics using machine learning techniques.
BACKGROUND: The shotgun strategy (liquid chromatography coupled with tandem mass spectrometry) is widely applied for identification of proteins in complex mixtures. This method gives rise to thousands of spectra in a single run, which are interpreted by computational tools. Such tools normally use a protein database from which peptide sequences are extracted for matching with experimentally derived mass spectral data. After the database search, the correctness of obtained peptide-spectrum matches (PSMs) needs to be evaluated also by algorithms, as a manual curation of these huge datasets would be impractical. The target-decoy database strategy is largely used to perform spectrum evaluation. Nonetheless, this method has been applied without considering sensitivity, i.e., only error estimation is taken into account. A recently proposed method termed MUDE treats the target-decoy analysis as an optimization problem, where sensitivity is maximized. This method demonstrates a significant increase in the retrieved number of PSMs for a fixed error rate. However, the MUDE model is constructed in such a way that linear decision boundaries are established to separate correct from incorrect PSMs. Besides, the described heuristic for solving the optimization problem has to be executed many times to achieve a significant augmentation in sensitivity. RESULTS: Here, we propose a new method, termed MUMAL, for PSM assessment that is based on machine learning techniques. Our method can establish nonlinear decision boundaries, leading to a higher chance to retrieve more true positives. Furthermore, we need few iterations to achieve high sensitivities, strikingly shortening the running time of the whole process. Experiments show that our method achieves a considerably higher number of PSMs compared with standard tools such as MUDE, PeptideProphet, and typical target-decoy approaches. CONCLUSION: Our approach not only enhances the computational performance, and thus the turn around time of MS-based experiments in proteomics, but also improves the information content with benefits of a higher proteome coverage. This improvement, for instance, increases the chance to identify important drug targets or biomarkers for drug development or molecular diagnostics
Index
Proceedings index of the Fourth International Congress of CiiEM: Health, Well-Being and Ageing in the 21st Century, held in the Egas Moniz University Campus at Monte de Caparica, Portugal, from 3–5 June 2019.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/ licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.info:eu-repo/semantics/publishedVersio
Real-time cosmography with redshift derivatives
The drift in the redshift of objects passively following the cosmological expansion has long been recognized as a key model-independent probe of cosmology. Here, we study the cosmological relevance of measurements of time or redshift derivatives of this drift, arguing that the combination of first and second redshift derivatives is a powerful test of the ΛCDM cosmological model. In particular, the latter can be obtained numerically from a set of measurements of the drift at different redshifts. We show that, in the low-redshift limit, a measurement of the derivative of the drift can provide a constraint on the jerk parameter, which is j=1 for flat ΛCDM, while generically j≠1 for other models. We emphasize that such a measurement is well within the reach of the ELT-HIRES and SKA Phase 2 array surveys
Kinematical and nonlocality effects on the nonmesonic weak hypernuclear decay
We derive in detail the transition potential for nonmesonic
lambda-hypernuclear decay in a one-meson-exchange model involving the full
pseudoscalar and vector meson octets and including two effects that have been
systematically omitted in the literature. These are the kinematical effects due
to the difference between the lambda and nucleon masses and the first-order
nonlocality corrections. Numerical results for C and
He are presented and they show that the combined kinematical plus
nonlocal corrections have an appreciable influence on the partial decay rates.
However, this is somewhat diminished in the main decay observables: the total
nonmesonic rate, the neutron-to-proton branching ratio, and the asymmetry
parameter. The latter two still cannot be reconciled with the available
experimental data. The existing theoretical predictions for the sign of the
asymmetry parameter in He are confirmed.Comment: 36 pages; LaTeX2e; 1 eps figure. Changes: 2 more tables and 14 new
references added; effects on asymmetry parameter calculated; discussions
expanded; more definite conclusions reache
Tattoo disease of odontocetes as a potential indicator of a degrading or stressful environment: a preliminary report. Scientific Committee document SC/55/E1, International Whaling Commission, May-June 2003, Berlin, Germany
We examined the presence of tattoo lesions in 613 small cetaceans belonging to nine species and originating from the Southeast Pacific Ocean, the Southwest and Northeast Atlantic Ocean as well as from the North, Baltic and Mediterranean Seas. Most of the specimens had been caught in nets or were found stranded in the period 1988-2002. Thirty-five bottlenose dolphins from the Sado estuary, Portugal were photographed alive in 1994-1997. Tattoo lesions were detected in 68 of 196 Lagenorhynchus obscurus, 33 of 54 Delphinus capensis, five of 12 Tursiops truncatus, 57 of 95 Phocoena spinipinnis from Peru as well as in 17 of 35 T. truncatus from the Sado estuary, in two of 10 Stenella coeruleoalba and one of four T. truncatus from the Mediterranean Sea. Prevalence of the disease varied significantly between species in mature specimens but not among immatures. It also varied very significantly between inshore (P. spinipinnis and Sado T. truncatus) and offshore or offshore-neritic (S. coeruleoalba, L. obscurus, D. capensis and Peruvian T. truncatus) odontocetes, being higher in adult specimens of inshore (53.5%) than of offshore (29.7%) taxa. This variation may be caused by immunotoxic environmental pollutants of continental origin like organochlorines. The coastal waters of Peru and the Sado estuary suffer from eutrophication and pollution from various origins. Direct correlation with pollutant loads needs to be investigated
Application of Model-driven engineering to multi-agent systems: a language to model behaviors of reactive agents
Many users of multi-agent systems (MAS) are very commonly disinclined to model and simulate using current MAS platforms. More specifically, modeling the dynamics of a system (in particular the agents' behaviors) is very often a challenge to MAS users. This issue is more often observed in the domain of socio-ecological systems (SES), because SES domain experts are rarely programmers. Indeed, the majority of MAS platforms were not conceived taking into consideration domain-experts who are non-programmers. Most current MAS tools are not dedicated to SES, or nor do they possess an easily understandable formalism to represent the behaviors of agents. Moreover, because it is platform-dependent, a model realized in a given MAS platform cannot be properly used on another platform due to incompatibility between MAS platforms. To overcome these limitations, we propose a domain-specific language (DSL) to describe the behaviors of reactive agents, regardless of the MAS platform used for simulation. To achieve this result, we used model-driven engineering (MDE), an approach that provides tools to develop DSLs from a meta-model (abstract syntax), textual editors with syntax highlighting (for the concrete syntax) and code generation capabilities (for source-code generation of a model). As a result, we implemented a language and a textual editor that allow SES domain experts to describe behaviors in three different ways that are close to their natural expression: as equations when they are familiar with these, as a sequence of activities close to natural language or as an activity diagram to represent decisions and a sequence of behaviors using a graphic formalism. To demonstrate interoperability, we also developed code generators targeting two different MAS platforms (Cormas and Netlogo). We tested the code generators by implementing two SES models with the developed DSL. The generated code was targeted to both MAS platforms (Cormas and Netlogo), and successfully simulated in one of them. We conclude that the MDE approach provides adequate tools to develop DSL and code generators to facilitate MAS modeling and simulation by non-programmers. Concerning the DSL developed, although the behavioral aspect of MAS simulation is part of the complexity of modeling in MAS, there are still other essential aspects of model and simulation of MAS that are yet to be explored, such as model initialization and points of view on the model simulated worl
Genetic markers in the study of Anisakis typica (Diesing, 1860): larval identification and genetic relationships with other species of Anisakis Dujardin, 1845 (Nematoda: Anisakidae)
Genetic variation at 21 gene-enzyme systems was studied in a sample of an adult population of Anisakis typica
(Diesing, 1860) recovered in the dolphin Sotalia fluviatilis from the Atlantic coast of Brazil. The characteristic
alleles, detected in this population, made it possible to identify as A. typica, Anisakis larvae with a Type I morphol ogy (sensu Berland, 1961) from various fishes: Thunnus thynnus and Auxis thazard from Brazil waters, Trachurus
picturatus and Scomber japonicus from Madeiran waters, Scomberomorus commerson, Euthynnus affinis, Sarda
orientalis and Coryphaena hippurus from the Somali coast of the Indian Ocean, and Merluccius merluccius from
the Eastern Mediterranean. Characteristic allozymes are given for the identification, at any life-stage and in both
sexes, of A. typica and the other Anisakis species so far studied genetically. The distribution of A. typica in warmer
temperate and tropical waters is confirmed; the definitive hosts so far identified for this species belong to delphinids,
phocoenids and pontoporids. The present findings represent the first established records of intermediate/paratenic
hosts of A. typica and extend its range to Somali waters of the Indian Ocean and to the Eastern Mediterranean
Sea. A remarkable genetic homogeneity was observed in larval and adult samples of A. typica despite their
different geographical origin; interpopulation genetic distances were low, ranging from DNei = 0.004 (Eastern
Mediterranean versus Somali) to DNei = 0.010 (Brazilian versus Somali). Accordingly, indirect estimates of gene
flow gave a rather high average value of Nm = 6.00. Genetic divergence of A. typica was, on average, DNei = 1.12
from the members of the A. simplex complex (A. simplex s.s, A. pegreffii, A. simplex C) and DNei = 1.41 from
A. ziphidarum, which all share Type I larvae; higher values were found from both A. physeteris (DNei = 2.77) and A. brevispiculata (DNei = 2.52), which have Type II larvae (sensu Berland, 1961). Genetic relationships
among these species are shown using multidimensional scaling ordination (MDS). The genus Anisakis appears to
be phylogenetically heterogeneous and includes two distinct groups of species, which are morphologically and
genetically differentiated.info:eu-repo/semantics/publishedVersio
Effect of a Co-Stimulatory Endodomain on the Performance of T Cells Expressing a Chimeric Antigen Receptor Directed at CD19 in Patients With Relapsed/Refractory B-Cell Malignancies
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