159 research outputs found

    Prognosing the Compliance of Declarative Business Processes Using Event Trace Robustness

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    Several proposals have studied the compliance of execution of business process traces in accordance with a set of compliance rules. Unfortunately, the detection of a compliance violation (diagnosis) means that the observed events have already violated the compliance rules that describe the model. In turn, the detection of a compliance violation before its actual occurrence would prevent misbehaviour of the business processes. This functionality is referred to as proactive management of compliance violations in literature. However, existing approaches focus on the detection of inconsistencies between the compliance rules or monitoring process instances that are in a violable state. The notion of robustness could help us to prognosticate the occurrence of these inconsistent states in a premature way, and to detect, depending on the current execution state of the process instance, how “close” the execution is to a possible violation. On top of being able to possibly avoid violations, a robust trace is not sensitive to small changes. In this paper we propose the way to determine whether a process instance is robust against a set of compliance rules during its execution at runtime. Thanks to the use of constraint programming and the capacities of super solutions, a robust trace can be guaranteed

    Comparison of the thermal decomposition processes of several aminoalcohol-based ZnO inks with one containing ethanolamine

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    Four inks for the production of ZnO semiconducting films have been prepared with zinc acetate dihy-drate as precursor salt and one among the following aminoalcohols: aminopropanol (APr), aminomethylbutanol (AMB), aminophenol (APh) and aminobenzyl alcohol (AB) as stabilizing agent. Their thermaldecomposition process has been analyzed in situ by thermogravimetric analysis (TGA), differential scan-ning calorimetry (DSC) and evolved gas analysis (EGA), whereas the solid product has been analysedex-situ by X-ray diffraction (XRD) and infrared spectroscopy (IR). Although, except for the APh ink, crys-talline ZnO is already obtained at 300◦C, the films contain an organic residue that evolves at highertemperature in the form of a large variety of nitrogen-containing cyclic compounds. The results indicatethat APr can be a better stabilizing agent than ethanolamine (EA). It gives larger ZnO crystal sizes withsimilar carbon content. However, a common drawback of all the amino stabilizers (EA included) is thatnitrogen atoms have not been completely removed from the ZnO film at the highest temperature of ourexperiments (600◦C)

    T-cell allorecognition of donor glutathione S-transferase T1 in plasma cell-rich rejection

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    AIM: To investigate the role of glutathione S-transferase T1 donor-specific T lymphocytes in plasma cell-rich rejection of liver allografts. METHODS: The study group included 22 liver transplant patients. Among them, 18 patients were mismatched for the glutathione S-transferase T1 (GSTT1) alleles (don+/rec-), and 4 were matched (don+/rec+). Seven of the mismatched patients produced anti-GSTT1 antibodies and developed plasma cell-rich rejection (former de novo immune hepatitis). For the detection of specific T lymphocytes, peripheral blood mononuclear cells were collected and stored in liquid nitrogen. The memory T cell response was studied by adding to the cell cultures to a mix of 39 custom-made, 15-mer overlapping peptides, which covered the entire GSTT1 amino acid sequence. The specific cellular response to peptides was analyzed by flow cytometry using the markers CD8, CD4, IL-4 and IFNγ. RESULTS: Activation of CD8+ T cells with different peptides was observed exclusively in the group of patients with plasma-cell rich rejection (3 out of 7), with production of IL-4 and/or IFNγ at a rate of 1%-4.92% depending on the peptides. The CD4+ response was most common and not exclusive for patients with the disease, where 5 out of 7 showed percentages of activated cells from 1.24% to 31.34%. Additionally, two patients without the disease but with the mismatch had cells that became stimulated with some peptides (1.45%-5.18%). Highly unexpected was the finding of a double positive CD4+CD8low T cell population that showed the highest degree of activation with some of the peptides in 7 patients with the mismatch, in 4 patients with plasma cell-rich rejection and in 3 patients without the disease. Unfortunately, CD4+CD8low cells represent 1% of the total number of lymphocytes, and stimulation could not be analyzed in 9 patients due to the low number of gated cells. Cells from the 4 patients included as controls did not show activation with any of the peptides. CONCLUSION: Patients with GSTT1 mismatch can develop a specific T-cell response, but the potential role of this response in the pathogenesis of plasma cell-rich rejection is unknown

    Role of Ethanolamine on the Stability of a Sol-Gel ZnO ink

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    This work presents a detailed structural and chemical characterization of the system formed by zinc acetate dihydrate (ZAD) and ethanolamine (EA) with methoxyethanol (ME), in order to describe its stability. The origin of the mixture degradation during storage at room conditions is analyzed. Complementary computational (or theoretical) DFT calculations on the precursor formed in this reaction in ME and those of EA (free or in the same solvent) and in the presence or absence of CO2, light or both simultaneously are also reported in order to clarify the relative weight of these factors in the degradation process. In all cases, the models were tested as potential energy minimum and their photo-absorption spectra were simulated. The calculations show that the monomeric species formed in this process tend to assembly into dimers, which are more photosensitive and reactive than the monomer. Our results explain the experimental observations and provide a better understanding of the role played by EA, ME and CO2 in the formation of ZnO and, consequently, allow optimizing the technological processes to prepare these films

    Study of a sol-gel precursor and its evolution towards ZnO

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    The processes involved in the assembly of zinc acetate dihydrate {Zn(CH3COO)2·2H2O} and ethanolamine (H2NCH2CH2OH), with or without 2-methoxyethanol as solvent, have been analysed by infrared spectra, mass spectrometry, nuclear magnetic resonance, powder X-ray diffraction and computational studies. Thermal evolution of the mixtures was characterized by thermoanalytical and structural techniques (thermogravimetry, differential thermal analysis, differential scanning calorimetry, X-ray diffraction and X-Ray photoelectron spectroscopy). Computational studies together with experiments served to thoroughly describe the precursor and its decomposition. The thermal decomposition of the mixture and its transformation into crystalline ZnO take place in a temperature range between 50 and 450 °C through different processes. With solvent, the processes need temperatures 90 oC higher with respect to the mixture without solvent, and ZnO arises at 250 ºC

    Influence of the Nature of Aminoalcohol on ZnO Films Formed by Sol-Gel Methods

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    Here we present comparative studies of: (i) the formation of ZnO thin films via the sol-gel method using zinc acetate dihydrate (ZAD), 2-methoxyethanol (ME) as solvent, and the aminoalcohols (AA): ethanolamine, (S)-(+)-2-amino-1-propanol, (S)-(+)-2-amino-3-methyl-1-butanol, 2-aminophenol, and aminobenzyl alcohol, and (ii) elemental analyses, infrared spectroscopy, X-ray diffraction, scanning electron microscopy, absorption and emission spectra of films obtained after deposition by drop coating on glass surface, and thermal treatments at 300, 400, 500 and 600 ◦C. The results obtained provide conclusive evidences of the influence of the AA used (aliphatic vs. aromatic) on the ink stability (prior to deposition), and on the composition, structures, morphologies, and properties of films after calcination, in particular, those due to the different substituents, H, Me, or iPr, and to the presence or the absence of a -CH2- unit. Aliphatic films, more stable and purer than aromatic ones, contained the ZnO wurtzite form for all annealing temperatures, while the cubic sphalerite (zinc-blende) form was also detected after using aromatic AAs. Films having frayed fibers or quartered layers or uniform yarns evolved to 'neuron-like' patterns. UV and photoluminescence studies revealed that these AAs also affect the optical band gap, the structural defects, and photo-optical properties of the films

    From ethanolamine precursor towards ZnO - How N is released from the experimental and theoretical points of view

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    This work presents experimental and computational studies on ZnO formation after decomposition of a sol-gel precursor containing ethanolamine and Zn(II) acetate. The structural modifications suffered during decomposition of the monomeric and dimeric Zn(II) complexes formed, containing bidentate deprotonated ethanolamine and acetato ligands, have been described experimentally and explained via Car-Parrinello Molecular Dynamics. Additional metadynamics simulations provide an overview of the dimer evolution by the cleavage of the Zn-N bond, the structural changes produced and their effects on the Zn(II) environment. The results provide conclusive evidence of the relevance of ethanolamine used as a stabilizer in the formation of ZnO

    Heterosis y aptitud combinatoria para producción y calidad de forraje en seis poblaciones de maíz

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    Six corn populations drawn from outstanding forage quality germplasm, and 15 of their direct crosses were assessed in four sites located between 1,117 and 1,932 m asl. The purpose of the present study was to determine general and specific combining ability and mid parent heterosis for whole plant dry matter (TDM), ear dry matter (EDM), stover dry matter (SDM), in vitro dry matter digestibility (IVDMD), neutral detergent fiber content (NDF) and crude protein (CP). Populations showed significant differences for all dry matter yield characteristics, but not for forage quality, while crosses showed differences for EDM and IVDMD. General combining ability effects (GCA) were high and significant only for TDM, while specific combining ability effects (SCA) were significant for IVDMD. Population P3 had the highest GCA for TDM (0.66 t ha-1) and P5F for EDM (0.49 t ha-1). Early cross P1*P2 had the highest heterosis for TDM (17.6 %) and highly significant SCA effects for both TDM and IVDMD (1.48 t ha-1 and 22.6 g kg-1, respectively), while crosses P2*P5F, P1*P4 and P1*P6F had high mid parent heterosis for EDM, with values ranging from 18.6 % to 26.2 %. None of the crosses showed mid parent heterosis for forage traits of importance.Seis poblaciones de maíz derivadas de fuentes de germoplasma sobresalientes por sus cualidades forrajeras y sus 15 cruzas directas se evaluaron en cuatro localidades entre 1,117 y 1,932 m sobre el nivel del mar. El objetivo fue determinar la aptitud combinatoria general y específica, y la heterosis media para variables de producción: materia seca total (MST), de elote (MSEL) y de rastrojo (MSRAS) y variables de calidad del forraje: digestibilidad in vitro de la materia seca (DIVMS), contenido de fibra detergente neutro (FDN) y proteína cruda (PC). Las poblaciones difirieron significativamente en las tres variables de producción, pero no en calidad forrajera, en cambio las cruzas difirieron en producción de MSEL y en DIVMS. Los efectos de aptitud combinatoria general (ACG) fueron significativos sólo para MST y MSEL, mientras que los efectos de aptitud combinatoria específica (ACE), lo fueron adicionalmente para DIVMS. La población P3 tuvo la mayor ACG para MST (0.66 t ha-1), y la población P5F para MSEL (0.49 t ha-1). La cruza precoz P1xP2 presentó la heterosis media más alta para MST con 17.6 % y efectos positivos y significativos de ACE para MST y DIVMS con valores de 1.48 t ha-1 y 22.6 g kg-1. En cambio, las cruzas P2xP5F, P1xP4 y P1xP6F tuvieron los valores de heterosis más altos para MSEL con valores de 18.1 a 26.2 %. Ninguna cruza tuvo heterosis media importante para caracteres de calidad de forraje

    Increasing dominance of large lianas in Amazonian forests

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    Ecological orthodoxy suggests that old-growth forests should be close to dynamic equilibrium, but this view has been challenged by recent findings that neotropical forests are accumulating carbon and biomass, possibly in response to the increasing atmospheric concentrations of carbon dioxide. However, it is unclear whether the recent increase in tree biomass has been accompanied by a shift in community composition. Such changes could reduce or enhance the carbon storage potential of old-growth forests in the long term. Here we show that non-fragmented Amazon forests are experiencing a concerted increase in the density, basal area and mean size of woody climbing plants (lianas). Over the last two decades of the twentieth century the dominance of large lianas relative to trees has increased by 1.7–4.6% a year. Lianas enhance tree mortality and suppress tree growth, so their rapid increase implies that the tropical terrestrial carbon sink may shut down sooner than current models suggest. Predictions of future tropical carbon fluxes will need to account for the changing composition and dynamics of supposedly undisturbed forests
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