An Object-Oriented Approach to Knowledge Representation in a Biomedical Domain

An object-oriented approach has been applied to the different stages involved in developing a knowledge base about insulin metabolism. At an early stage the separation of terminological and assertional knowledge was made. The terminological component was developed by medical experts and represented in CORE. An object-oriented knowledge acquisition process was applied to the assertional knowledge. A frame description is proposed which includes features like states and events, inheritance and collaboration. States and events are formalized with qualitative calculus. The terminological knowledge was very useful in the development of the assertional component. It assisteed in understanding the problem domain, and in the implementation stage, it assisted in building good inheritance hierarchies

Exploring new frontiers in modeling complex zeolite-catalyzed reactions using advanced molecular dynamics techniques

We show the potential of advanced molecular dynamics techniques to obtain insight into the complex MTO process by thoroughly studying proton mobility and mapping free energy surfaces of reaction steps at high temperature. The applied methodology can be used to unravel any complex zeolitic process at the nanometer scale level

On the origin of the extremely different solubilities of polyethers in water

The solubilities of polyethers are surprisingly counter-intuitive. The best-known example is the difference between polyethylene glycol ([–CH2–CH2–O–]n) which is infinitely soluble, and polyoxymethylene ([–CH2–O–]n) which is completely insoluble in water, exactly the opposite of what one expects from the C/O ratios of these molecules. Similar anomalies exist for oligomeric and cyclic polyethers. To solve this apparent mystery, we use femtosecond vibrational and GHz dielectric spectroscopy with complementary ab initio calculations and molecular dynamics simulations. We find that the dynamics of water molecules solvating polyethers is fundamentally different depending on their C/O composition. The ab initio calculations and simulations show that this is not because of steric effects (as is commonly believed), but because the partial charge on the O atoms depends on the number of C atoms by which they are separated. Our results thus show that inductive effects can have a major impact on aqueous solubilities

Antibioticagebruik deels afhankelijk van bedrijfsvoering

Het antibioticagebruik op bedrijven varieert in hoge mate. De verschillen blijken deels afhankelijk van de bedrijfsvoering. De melkveehouder met een wat groter quotum, lager celgetal en hogere gezondheidsstatus gebruikt meer. Dit is in feite de ‘succesvolle’ veehouder. Dit lijkt dus de groep om op te focussen

Nonequilibrium candidate Monte Carlo: A new tool for efficient equilibrium simulation

Metropolis Monte Carlo simulation is a powerful tool for studying the equilibrium properties of matter. In complex condensed-phase systems, however, it is difficult to design Monte Carlo moves with high acceptance probabilities that also rapidly sample uncorrelated configurations. Here, we introduce a new class of moves based on nonequilibrium dynamics: candidate configurations are generated through a finite-time process in which a system is actively driven out of equilibrium, and accepted with criteria that preserve the equilibrium distribution. The acceptance rule is similar to the Metropolis acceptance probability, but related to the nonequilibrium work rather than the instantaneous energy difference. Our method is applicable to sampling from both a single thermodynamic state or a mixture of thermodynamic states, and allows both coordinates and thermodynamic parameters to be driven in nonequilibrium proposals. While generating finite-time switching trajectories incurs an additional cost, driving some degrees of freedom while allowing others to evolve naturally can lead to large enhancements in acceptance probabilities, greatly reducing structural correlation times. Using nonequilibrium driven processes vastly expands the repertoire of useful Monte Carlo proposals in simulations of dense solvated systems

Improving a Discharge Process to Decrease Readmission Rates

PURPOSE: The purpose of this quality improvement (QI) project was to improve the case management discharge instructions for patients in an inpatient psychiatric and medical unit. It utilized very specific directions on how to address disease progression symptoms outside of the acute care setting in an effort to achieve readmission rates below the 10th percentile (the unit desired). The current case management discharge process was modified in three ways, including: 1) modification of the case management discharge instructions into a user-friendly, one-page format written on a fifth-grade reading level, 2) dividing the discharge instructions section of warning signs into three categories: mild, moderate, and severe symptoms, and 3) the inclusion of a treatment sheet into the new discharge instructions which was given to the patient at discharge. Chart audits, interviews, observation, and pre- and post-intervention surveys were methods used to collect data regarding patient and nurse perceptions of the usefulness of the discharge instructions, as well as compliance with the new discharge process. OUTCOMES: User-friendliness of the discharge instruction was improved significantly from 20% to 87%. Post implementation, all nurses instructed patients about the warning symptoms on the new discharge form. The completion of the discharge compliance summary improved from 75% to 100%. IMPACT: The nurses and QI team reported satisfaction with the new form’s content and user-friendliness, increasing the likelihood that it will be used and potentially reduce readmission rates

Evaluating the microbial experience influence on anti-tumor immune response

Despite the steady increase of hygienic standards, the CDC continues to report an increase of immune-mediated diseases such as allergies and asthma. Human avoidance of microbial exposure and subsequently less experienced immune systems may be the cause for this increase. We investigated if increased microbial exposure results in increased immunity to cancer (B16 melanoma) by measuring activated lymphocytes between two groups of C57Bl/6 mice: specific pathogen free (SPF) mice (which had little microbial exposure) and cohoused (COH) mice (which were exposed to numerous microbes). Previous research shows that the CoH mouse model mimics a human adult’s immune system, while the SPF mouse model mimics that of a human infant’s. Activated lymphocyte levels were quantified with weekly bleeds using antibody staining flow cytometry. Anti-tumor response was evaluated through multiple harvests in which blood, lymph nodes, spleens, and tumors were collected and analyzed with flow cytometry. CoH mice were expected to have heightened levels of activated lymphocytes and an anti-tumor response superior to the SPF mice. The CoH mice did gain microbial experience and showed in a higher quantity of activated CD8+ T cells. Preliminary results suggest that this may have resulted in an increased anti-tumor response and slowed cancer proliferation