Data strip mining for the virtual design of pharmaceuticals withneural networks

A novel neural network based technique, called "data strip mining" extracts predictive models from data sets which have a large number of potential inputs and comparatively few data points. This methodology uses neural network sensitivity analysis to determine which predictors are most significant in the problem. Neural network sensitivity analysis holds all but one input to a trained neural network constant while varying each input over its entire range to determine its effect on the output. Elimination of variables through neural network sensitivity analysis and predicting performance through model cross-validation allows the analyst to reduce the number of inputs and improve the model's predictive ability at the same time. This paper demonstrates its effectiveness on a pair of problems from combinatorial chemistry with over 400 potential inputs each. For these data sets, model selection by neural sensitivity analysis outperformed other variable selection methods including the forward selection and genetic algorithm.     

Hybrid identification of nuclear power plant transients with artificial neural networks

Proper and rapid identification of malfunctions (transients) is of premier importance for the safe operation of nuclear power plants. Feedforward neural networks trained with the backpropagation (BP) algorithm are frequently applied to model simulated nuclear power plant malfunctions. The correct identification of unlabeled transients-or transients of the "don't-know" type have proven to be especially challenging. A novel hybrid neural network methodology is presented which also correctly classifies the unlabeled transients. From this analysis the importance for properly accommodating practical aspects such as the drift of electronics elements of a simulator, the digitization of simulated and actual plant signals, and the accumulating errors during numerical integration became obvious. Beside the feedforward neural networks trained with the BP algorithm, many other types of networks and codes were used for finding the best (sensitive and robust) algorithms. Various neural network based models were successfully applied to identify labeled and unlabeled malfunctions of the Hungarian Paks nuclear power plant simulator. The BP and probabilistic methods have been proven as the most robust against the misleading recognition of unlabeled malfunctions.     

Preparation and analysis of poly(l-lactic acid) composites with oligo(d-lactic acid)-grafted cellulose

α-Cellulose extracted from jute fiber was grafted with oligo( d -lactic acid) (ODLA) via a graft polycondensation reaction in the presence of para-toluene sulfonic acid and potassium persulfate in toluene at 130 °C for 9 h under 380 mmHg. ODLA was synthesized by the ring-opening polymerization of d -lactides in the presence of stannous octoate (0.03 wt % lactide) and d -lactic acid at 140 °C for 10 h. Composites of poly( l -lactic acid) (PLLA) with the ODLA-grafted α-cellulose were prepared by the solution-mixing and film-casting methods. The grafting of ODLA onto α-cellulose was confirmed by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The analysis of the composites was performed with FTIR spectroscopy, SEM, wide-angle X-ray diffraction, and thermogravimetric analysis. The distribution of the grafted α-cellulose in the composites was uniform and showed better compatibility with PLLA through intermolecular hydrogen bonding. Only homocrystalline structures of PLLA were present in the composites, and the thermal stability increased with increasing percentage of grafted α-cellulose. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47424.     

Good for learning,bad for motivation? A meta-analysis on the effects of computer-supported collaboration scripts

International Journal of Computer-Supported Collaborative Learning - Scripting computer-supported collaborative learning has been shown to greatly enhance learning, but is often criticized for...     

A Controlled Agitation Process for Improving Quality of Canned Green Beans during Agitation Thermal Processing

This work introduces the concept of a controlled agitation thermal process to reduce quality damage in liquid‐particulate products during agitation thermal processing. Reciprocating agitation thermal processing (RA‐TP) was used as the agitation thermal process. In order to reduce the impact of agitation, a new concept of “stopping agitations after sufficient development of cold‐spot temperature” was proposed. Green beans were processed in No. 2 (307×409) cans filled with liquids of various consistency (0% to 2% CMC) at various frequencies (1 to 3 Hz) of RA‐TP using a full‐factorial design and heat penetration results were collected. Corresponding operator's process time to impart a 10‐min process lethality (F_o) and agitation time (AT) were calculated using heat penetration results. Accordingly, products were processed again by stopping agitations as per 3 agitation regimes, namely; full time agitation, equilibration time agitation, and partial time agitation. Processed products were photographed and tested for visual quality, color, texture, breakage of green beans, turbidity, and percentage of insoluble solids in can liquid. Results showed that stopping agitations after sufficient development of cold‐spot temperatures is an effective way of reducing product damages caused by agitation (for example, breakage of beans and its leaching into liquid). Agitations till one‐log temperature difference gave best color, texture and visual product quality for low‐viscosity liquid‐particulate mixture and extended agitations till equilibration time was best for high‐viscosity products. Thus, it was shown that a controlled agitation thermal process is more effective in obtaining high product quality as compared to a regular agitation thermal process.     

Long-term effects of dissolved carbonate species on the degradation of trichloroethylene by zerovalent iron

The effect of different concentrations of total inorganic carbon (TIC) and flow rates on the reactivity of iron metal with trichloroethylene (TCE) was studied in column experiments to verify whether concentration or mass flux of TIC is the major key parameter for barrier performance. First-order rate coefficients (kobs) for TCE degradation vary initially between 0.15 and 0.32 h-' and are positively related to TIC influent concentration. Maximal kobs were reached after 164 and 591 PV, varied between 0.55 and 1.1 h(-1), and were positively correlated to the TIC mass flux, followed by a decrease resulting in values similar to the reference system at the end of the experiments. Enhancement of iron corrosion (0.7 to 3.5 mmol kgFe(-1) d(-1) and formation of gas bubbles during the initial experimental phase were observed and were also positively correlated to TIC mass flux. The higher gas bubble formation probably has a more significant effect on porosity than mineral precipitations in Fe0-systems. The results suggest that higher TIC mass fluxes cause a more pronounced acceleration in CHC degradation, but also a faster inhibition in the longer-term. This faster inhibition has serious implication for the design of funnel and gate systems.     

Ethische Aspekte des Alter(n)s im Kontext von Medizin und Gesundheitsversorgung: Problemaufriss und Forschungsperspektiven

Definition of the problem

Due to the individual and societal consequences of demographic change, moral questions regarding old age and elderly persons are moving into the focus of public attention and of ethical debates in medicine, nursing and public health. In many of these debates, however, ageing as a process and old age as a phase of life is primarily considered from the angle of the respective practices, questions and problems discussed. What is missing is a perspective that comprises the different practical contexts, makes the underlying conceptions of age(ing) explicit and reflects their meaning for the ethical debate.

Arguments

The working group “Ageing and Ethics” in the Academy for Ethics in Medicine was established to contribute to such a more comprehensive perspective. This paper gives an overview of the central topics, problems and arguments in the contemporary medical, nursing and public health ethics discourses on age(ing) and marks open questions and desiderates.

Conclusions

A more intensive consideration of age(ing) can not only improve the theoretical basis of the pertaining debates in applied ethics but also shed light on some of the anthropological foundations and normative frameworks of ethical reasoning as such.