Forgetting Exceptions is Harmful in Language Learning

We show that in language learning, contrary to received wisdom, keeping exceptional training instances in memory can be beneficial for generalization accuracy. We investigate this phenomenon empirically on a selection of benchmark natural language processing tasks: grapheme-to-phoneme conversion, part-of-speech tagging, prepositional-phrase attachment, and base noun phrase chunking. In a first series of experiments we combine memory-based learning with training set editing techniques, in which instances are edited based on their typicality and class prediction strength. Results show that editing exceptional instances (with low typicality or low class prediction strength) tends to harm generalization accuracy. In a second series of experiments we compare memory-based learning and decision-tree learning methods on the same selection of tasks, and find that decision-tree learning often performs worse than memory-based learning. Moreover, the decrease in performance can be linked to the degree of abstraction from exceptions (i.e., pruning or eagerness). We provide explanations for both results in terms of the properties of the natural language processing tasks and the learning algorithms.     

Design and operation of a solar fired biomass flash pyrolysis reactor

The results of continuing research on the radiant flash pyrolysis of biomass as a source of fluid fuels, industrial feedstocks and chemicals are described in this paper. Windowed free fall reactors have been developed, which act as cavity receivers for the focused radiant energy and provide a means for direct use of the radiation to rapidly pyrolyze the entering biomass. Detailed results of experiments using the 400 kWth DOE Advanced Components Test Facility at Georgia Tech. are presented. These results suggest the use of concentrated solar energy as a selective means for the production of either a hydrocarbon rich synthesis gas or sugar related sirups from biomass by flash pyrolysis.     

Design and operation of a 30KWe/2KWth downward facing beam ARC image furnace

Fabrication and operation of a bench scale solar simulator are described in this paper. Many components of the system are off-the-shelf items. The furnace is capable of providing an intense light beam with total power of 2000 Wth and a peak flux density of 10⁷ W/m² (10,000 suns). This is the most intense downward facing light beam currently available in the U.S.A. The system was designed so that the total power delivered to the test section could be varied continuously. The technical approach used in fabricating this solar simulator is explained with sufficient detail to enable other researchers to design and operate similar systems. Utilization of the downward facing beam arc image furnace offers an inexpensive alternative to the use of intermediate size, solar thermal test facilities, which are few and often very costly to maintain and operate.     

The replacement of the fantasied oedipal child: A disruptive effect of sibling loss on the mother-infant relationship.

Presents the case of a 30-yr-old woman whose sibling had died during adolescence and who experienced her own child, almost 2 decades later, as a replacement for the lost sibling. This process was facilitated by the oedipal meaning of her sibling and by the interference in her family's ability to mourn the death of the child. The case illustrates the manner in which these conflicts were activated during the patient's pregnancy and how they subsequently interfered in the developing mother–infant relationship prior to intervention. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Studies on interactions between metmyoglobin and heparin

Butyric acid is released from milk by pre-intestinal lipases during suckling. It is also known to inhibit bacterial growth. To investigate whether butyric acid may be a significant factor in controlling bacterial growth in the stomach of pre-weaned animals, the ability of butyric acid to inhibit growth of selected bacteria was tested over physiological ranges of pH and butyric acid concentrations. Six enteric and environmental strains of bacteria were used: two strains of Escherichia coli, Klebsiella pneumoniae, Enterococcus faecium, Enterococcus faecalis, and Enterococcus casseliflavus. At pH 4.5 and 5.0, the growth of all organisms was significantly inhibited in the presence of butyrate, and in some cases growth was completely arrested. At pH 6.0, butyric acid did not affect bacterial growth until the concentration reached 40 mM. The maximum concentration of butyric acid available in cow's milk after incubation with pre-gastric lipase is approximately 16 mM, which would be sufficient to prevent growth of the organisms tested at pH values occurring in the stomach. Therefore, butyric acid inhibition of bacterial growth may explain in part, the role of pre-intestinal lipases in young animals' natural defenses against bacteria in ingested food prior to weaning.     

The interfacial behavior of cytochrome c studied by pendant-drop technique

Malnutrition is common and often undiagnosed in affected patients, especially those in the hospital, and is associated with impaired organ function, increased morbidity, and prolongation of hospital stay. It should be recognized and treated appropriately, because artificial nutritional support in malnourished patients leads to improvement in nutritional status and clinical outcome. There are multiple methods to provide nutrition, some by simply keeping the esophageal lumen patent, others by providing additional or all nutrients, including enteral and parenteral routes. The enteral route is preferred due to patient acceptance, lesser expense, and lower risk of complications. The addition of specific nutrients over standard diets may add benefit. Preoperative nutrition may reduce the risk of postoperative complications. Lastly, in the terminally ill patient, minimal intervention may be all that is needed to achieve the patient's comfort, perhaps the most important goal.     

Effect of heparin and dextran sulfate on the activity of glutathione reductase from yeast

Glutathione reductase (EC 1.6.4.2) is a pivotal enzyme of the glutathione antioxidant system in a cell. The kinetic studies of the interaction of glutathione reductase with unfractionated and low molecular weight heparin and dextran sulfate can contribute to explanation of polyanions effect on the conformation changes of glutathione reductase. The tested polyanions inhibit this enzyme and the inhibition effect depends on the ionic strengths and pH value. The most potent inhibitor is dextran sulfate (ID50 is 4.1 micrograms/ml, pH = 6.8, without NaCl). The ionic strength (> 100 mM) allows the reactivating of GR if the concentration of DS is not higher than 80 micrograms/ml. The inhibition effect of tested polyanions is caused by electrostatic interactions with enzyme; the kinetic analyses indicate that it is a mixed inhibition with respect to oxidized glutathione or NADPH.     

Kinetics of the thermal decomposition of cellulose under the experimental conditions of thermal analysis. Theoretical extrapolations to high heating rates

Thermobalance-mass spectrometer (TG-MS) experiments carried out by the authors in a period of 8 years are reviewed and analyzed. Celluloses and lignocellulosic biomass samples were studied. The data are evaluated by the method of least squares. The results indicate that a single rate-controlling reaction step dominates the kinetics of the cellulose decomposition at low heating rates (2–20°C/min) provided that the heat and mass transport problems are experimentally eliminated and the amount of catalytic impurities is reduced by dilute acid or hot water washing treatments. The kinetic parameters obtained from the experiments with different cellulose and biomass samples evidenced only ca 8% scattering. A simple explanation is given for the kinetic compensation effect observed. Theoretical extrapolations are presented to predict the behavior of extremely small, idealized cellulose samples at high heating rates.