Temporal stability in predictive process monitoring

Predictive process monitoring is concerned with the analysis of events produced during the execution of a business process in order to predict as early as possible the final outcome of an ongoing case. Traditionally, predictive process monitoring methods are optimized with respect to accuracy. However, in environments where users make decisions and take actions in response to the predictions they receive, it is equally important to optimize the stability of the successive predictions made for each case. To this end, this paper defines a notion of temporal stability for binary classification tasks in predictive process monitoring and evaluates existing methods with respect to both temporal stability and accuracy. We find that methods based on XGBoost and LSTM neural networks exhibit the highest temporal stability. We then show that temporal stability can be enhanced by hyperparameter-optimizing random forests and XGBoost classifiers with respect to inter-run stability. Finally, we show that time series smoothing techniques can further enhance temporal stability at the expense of slightly lower accuracy.     

Heating requirements in greenhouse farming in southern Italy: evaluation of ground-source heat pump utilization compared to traditional heating systems

Greenhouse farming, where energy consumptions are mainly related to the greenhouses heating, is one of the sectors consuming the most energy in the agricultural industry. High costs and the uncertain availability of fossil fuels constrain the use of heating applications. Among possible solutions, the utilization of renewable heating systems such as geothermal energy through ground-source heat pump systems (GSHPs) at competitive prices has to be taken in consideration. The competitiveness of these systems depends mainly on the characteristics of the end-users, i.e., the annual heating loads. Few studies focusing on the potential of using these systems start with an analysis of the thermal requirements and end with a cost evaluation in tune with local assets, geo-climatic conditions, and landscape protection. This paper analyzes the greenhouse crop industry in the Apulia region in southern Italy, as a potential end-user of GSHP systems. Data collected from an area mainly devoted to greenhouse crop production have been used to (a) describe greenhouse farms, (b) define the heating requirements of a greenhouse model representative of the most used typology in the investigated area, and (c) examine the economic viability of greenhouse heating with GSHP systems. Both vertical and horizontal ground heat exchanger (GHE) configurations are compared with conventional fossil-fuel heating systems. In all scenarios considered, the observed payback periods appear reasonable and worthy of consideration. The results suggest that these technologies can fully satisfy the winter heating requirements in a cost-effective way and they can support the planning of measures aimed to improve the sector competitiveness.     

Attenuation of Combined Nickel(II) Oxide and Manganese(II,III) Oxide Nanoparticles’ Adverse Effects with a Complex of Bioprotectors

Stable suspensions of NiO and Mn₃O₄ nanoparticles (NPs) with a mean (±s.d.) diameter of 16.7 ± 8.2 and 18.4 ± 5.4 nm, respectively, purposefully prepared by laser ablation of 99.99% pure nickel or manganese in de-ionized water, were repeatedly injected intraperitoneally (IP) to rats at a dose of 2.5 mg/kg 3 times a week up to 18 injections, either alone or in combination. A group of rats was injected with this combination with the background oral administration of a “bio-protective complex” (BPC) comprising pectin, vitamins A, C, E, glutamate, glycine, N-acetylcysteine, selenium, iodide and omega-3 PUFA, this composition having been chosen based on mechanistic considerations and previous experience. After the termination of injections, many functional and biochemical indices and histopathological features (with morphometric assessment) of the liver, spleen, kidneys and brain were evaluated for signs of toxicity. The Ni and Mn content of these organs was measured with the help of the atomic emission and electron paramagnetic resonance spectroscopies. We obtained blood leukocytes for performing the RAPD (Random Amplified Polymorphic DNA) test. Although both metallic NPs proved adversely bio-active in many respects considered in this study, Mn₃O₄-NPs were somewhat more noxious than NiO-NPs as concerns most of the non-specific toxicity manifestations and they induced more marked damage to neurons in the striatum and the hippocampus, which may be considered an experimental correlate of the manganese-induced Parkinsonism. The comparative solubility of the Mn₃O₄-NPs and NiO-NPs in a biological medium is discussed as one of the factors underlying the difference in their toxicokinetics and toxicities. The BPC has attenuated both the organ-systemic toxicity and the genotoxicity of Mn₃O₄-NPs in combination with NiO-NPs.     

Magnetoelectric effect in orthorhombic Gd2(MoO4)3

Dependences of the electric polarization upon the magnetic field in metastable orthorhombic ferroelectric ferroelastic paramagnetic β'-phase of Gd₂(MoO₄) were measured in direct current magnetic fields up to 19T at temperatures from 5K to 300K. The electric polarization was measured along the [001] axis in magnetic field along the [100] and [010] axes. The largest values of changes of the electric polarization that were induced by the magnetic field were of the order of (10^-11-10_-12)Q/cm².

A time dependence of the electric polarization at a constant field value was observed. Relatively large hysteresis on the field dependences of the electric polarization was observed at temperatures between liquid nitrogen and liquid helium. The dependences measured in magnetic fields directed along the [100] axis show jumps of the electric polarization in some cases. At liquid helium temperatures field dependences of the electric polarization show a tendency to the saturation. These are the first observations of the magnetoelectric effect in β'-gadolinium molybdate.     

In vitro efficacy of a hydrophilic central venous catheter loaded with silver to prevent microbial colonization

A method was developed to load the surface of a central venous catheter with silver to prevent bacterial colonization. Silver confers a broad antimicrobial activity with a relatively low risk of resistance. Catheters were incubated with a silver nitrate solution in different concentrations. The solvent, incubation temperature and incubation period were varied to examine the influence on the catheter loading. With increasing incubation temperature, time and concentration of silver nitrate, higher rates of silver elution were observed by atomic absorption spectroscopy. Furthermore, by using ethanol-water as a solvent instead of pure water, the amount of silver bound to the catheter surface was enhanced. The release of silver from the catheter surface is mainly controlled by first order kinetics. Antimicrobial efficacy of the modified catheter, in comparison to unloaded catheters, was tested in a stationary and a dynamic model with different microorganisms. Adherence experiments with Candida albicans showed almost complete inhibition of growth during a period of 72 hours, including initial adherence. While initial adherence of bacteria could not be prevented, these experiments showed an excellent reduction of bacterial colonization. In a perfusion model, adhesion of E. coli could be reduced for at least seven days. Further studies are planned to examine prolonged antimicrobial effects.     

Interpretation of doping phenomena in high-T c superconductors

On the basis of an indirect-exchange pairing mechanism of superconductivity we present a consistent interpretation of doping phenomena in both hole-doped as well as electron-doped high-T _c superconductors. We argue that in all these materials the unifying feature is the existence of a correlated narrow band of electron states formed due to doping. Numerous experimental evidences for the occurrence of such a band (reflectivity, thermoelectric power, electrical resistivity, X-ray absorption, point-contact tunneling etc.) now exist. Assuming the existence of such a band it was earlier shown that the indirect-exchange (superexchange) coupling between electrons in this band via closed-shell oxygen anions is attractive in the s-wave channel and leads to high-T _c superconductivity. Within the framework of this pairing mechanism, recent doping experiments (for both types of doping) can be given a unified interpretation. In addition, definitive predictions of the doping conditions under which critical temperatures are expected to enhance, are made.     

Ultraviolet erythema sensitivity in anamnestic (I-IV) and phototested (1-4) Caucasian skin phototypes: the need for a new classification system

The anamnestic skin phototypes (ASP) I-IV of 22 Caucasian volunteers wee compared with their phototested skin phototypes (PSP) using solar simulating, broadband UV radiation. The Commission Internationale de l'Eclairage (CIE)-weighted (i.e. erythemally effective) minimal erythema doses (MED) for solar simulating radiation varied from 20 mJ/cm2 (PSP type 1) to 57 mJ/cm2 (PSP type 4). In only 11 of 21 volunteers did the ASP (I-IV) and PSP (1-4) classifications coincide, and the MED values of the volunteers within the different ASP groups (I-IV) overlapped considerably. To compare the reactivity to erythematogenic radiation of different wavelengths, narrowband monochromator irradiations were performed at 298 nm, 310 nm and 330 nm. The CIE-weighted MED values at these wavelengths (20-80 mJ/cm2) corresponded well with those obtained in the broadband testing. Our results indicate that, with classification by interrogation, Caucasian skin can reliably be classified into only two subtypes, corresponding to Fitzpatrick phototypes I-III and phototype IV, respectively. A classification into four sensitivity types can be achieved by phototesting, only. We propose that the concept of ASP should be used with caution. The concept of PSP 1-4 should be favored.     

Increased liver lipase activity in rats with essential fatty acid deficiency

Liver lipase activity was measured in EFA-deficient rats (long-term) and in control rats and rats fed an EFA-deficient diet for two weeks (short-term). Liver lipase activity was significantly enhanced by EFA deficiency, both in long-term and short-term experiments. The enhanced liver lipase activity could be normalized by feeding these rats normal laboratory chow for 14 days. Since during EFA deficiency prostaglandin synthesis is impaired, the possible involvement of prostaglandins in the observed changes in liver lipase actvity during EFA deficiency was studied. Administration of the prostaglandin synthesis inhibitor indomethacin (5 mg/kg body weight, i.p.) to normally fed rats for two days led to an increase of liver lipase activity. Prostaglandin E₂ was found to inhibit the secretion of liver lipase activity by freshly isolated parenchymal liver cellsin vitro. These results indicate that the increase in liver lipase activity during EFA deficiency may be due to an impairment of the prostaglandin synthesis.