A connectionist model of septohippocampal dynamics during conditioning: Closing the loop.

Septohippocampal interactions determine how stimuli are encoded during conditioning. This study extends a previous neurocomputational model of corticohippocampal processing to incorporate hippocamposeptal feedback and examines how the presence or absence of such feedback affects learning in the model. The effects of septal modulation in conditioning were simulated by dynamically adjusting the hippocampal learning rate on the basis of how well the hippocampal system encoded stimuli. The model successfully accounts for changes in behavior and septohippocampal activity observed in studies of the acquisition, retention, and generalization of conditioned responses and accounts for the effects of septal disruption on conditioning. The model provides a computational, neurally based synthesis of prior learning theories that predicts changes in medial septal activity based on the novelty of stimulus events. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recent advances in cancer therapy

The treatment of cancer has developed substantially from its conception in the first years of the 20th century. Since the introduction of alkylating agents during second World War, the oncology specialty has markedly grown. In the recent years, new drugs have been approved for the treatment of cancer. Such examples include the taxanes (Docetaxel and Paclitaxel), Vinorelbine, Irinotecan, Topotecan, Gemcitabine and Gliadel. We will discuss these new chemotherapuetic agents, their pharmacology, indications, toxicity and appropriate dosing. There is no doubt that further clinical research is needed to determine the optimal use of these agents.     

The Timing of Uncertainty and the Intensity of Policy

This article analyzes the trade-off between `caution' and `intensity' in the use of the control variable in a one-state one-control dynamic stochastic quadratic linear optimization problem with discount factor. It studies the effects that changes in uncertainty of the control parameter have on the optimal first period response of the control variable, showing that the trade-off between `caution' and `intensity' depends on the timing of the uncertainty. Given an increase in current uncertainty and an equal increase in future uncertainty, caution will always prevail over intensity. Moreover, the prevalence of caution will be enlarged as the increase in future uncertainty moves farther away into the future, while this prevalence will be reduced as the increase in future uncertainty expands into the future. Finally, for the infinite horizon case, caution is the optimal policy response.     

A performance and manufacturability evaluation of bump chip carrier packages

Bump chip carrier [(BCC) registered trademark of Fujitsu Ltd.] is an attractive solution to the demand of high packaging density of low input/output (I/O)-count packages. In this paper, an extensive finite element thermomechanical analysis has been conducted to evaluate the reliability of BCC packages, both with and without heat slugs, during thermal cycling. The effect of a variety of parameters on package reliability has been evaluated, including board thickness, package size mold material, solder paste thickness, and terminal height. The solder reliability of corner leads versus inner leads, as well as square leads versus rectangular leads has also been investigated. During manufacturing, molded panels for BCC packages undergo significant warpage. Two types of mold designs are compared through three-dimensional finite element analysis. A variety of mold compound materials have been evaluated. The most effective ways to reduce manufacturing-induced warpage have been suggested.     

Computational Economics: Help for the Underestimated Undergraduate

Our concern in this paper is that the capability of economics undergraduates is substantially underestimated in the design of the present college curriculum and that our students are insufficiently challenged and motivated. Students enter our classrooms with substantial previous knowledge about computers and computation and we are not taking full advantage of this opportunity. We suggest a set of examples from computational economics which are challenging enough to motivate students and simple enough that they can master them within a few hours. By encouraging the students to modify the models in directions of their own interest, avenues for creative endeavor are opened which deeply involve the students in their own education.     

Comparative analysis of some anthropometric measurements

The main objective of this work is to determine what anthropometric method to use under field conditions, given the kind of mainutrition to be detected. In the first part of the work some criteria and procedures are given by which to compare the field perfomance characteristics (i.e. transportability, facility of use, etc.), of the most commonly used instruments. Then we extrapolate these characteristics to the respective methods like weight for age, weight for height, height for age, etc. In the second part we present a correlation matrix among the various methods and analyze it in order to associate with each method a specific typology of malnutrition.     

Probabilistic Boolean network modeling and model checking as an approach for DFMEA for manufacturing systems

Modeling manufacturing processes assists the design of new systems, allowing predictions of future behaviors, identifying improvement areas and evaluating changes to existing systems. Probabilistic Boolean networks (PBN) have been used to study biological systems, since they combine uncertainty and rule-based representation. A novel approach is proposed to model the design of an automated manufacturing assembly processes using PBNs to generate quantitative data for occurrence assessment in design failure mode and effects analysis. FMEA is a widely used tool in risk assessment (RA) to ensure design outputs consistently deliver the intended level of performance. Effectiveness of RA depends upon the robustness of the data used. Temporal logic is applied to analyze state successions in a transition system, while interactions and dynamics are captured over a set of Boolean variables using PBNs. Designs are therefore enhanced through assessment of risks, using proposed tools in the early phases of design of manufacturing systems. A two-sample T test demonstrates the proposed model provides values closer to expected values; consequently modeling observable phenomena (\(p\,\hbox {value} > 0.05\)). Simulations are used to generate data required to conduct inferential statistical tests to determine the level of correspondence between model prediction and real machine data.     

Methane Transformation using Light Gasoline as Co-Reactant over Zn/H-ZSM11

The catalytic conversion of methane (C1) to aromatic hydrocarbons (AH) such as benzene, toluene and xylenes (BTX) over a Zn/H-ZSM-11 catalyst using Light Gasoline (C5+C6) as co-reactant was studied. AH yields were as high as 30 %mol at 500 °C, w/f = 40 g h mol⁻¹ at C1 molar fraction = 0.20. The contact time and time-on-stream effects on the product distribution, were analyzed in detail in order to obtain information about the evolution of different species. The C1 conversion reached 36 mol% C using Zn/HZSM-11 with content of 2.13 mol of Zn²⁺ per cell unit.     

Changes in coping style and treatment outcome following motor vehicle accident.

Background: Motor vehicle accidents (MVAs) are highly prevalent and can result in a complex interplay of physical injury, disability, and emotional distress. It has been suggested that the manner in which individuals cope with pain experienced after injury may determine how much recovery of function can be achieved. Only a limited number of studies have examined this process in the context of a rehabilitation program, and to date few studies have examined both functional and quality of life outcomes in MVA recovery in a tertiary level program as a function of coping style. Methods: A sample of 96 consecutive referrals to a tertiary-level multidisciplinary functional restoration program completed physical performance measures pre- and post-treatment, as well as a standardized self-report measure of quality of life (QOL) at the same time points and 6-month follow-up. Results: Findings suggested that improvements from pre- to post-treatment were evident on the 6-minute walk test, left and right grip strength, and most QOL measures. Increases in active coping during treatment were associated with pre- to post-treatment increases in QOL across most domains, and improvements in performance on the 6-minute walk test. Likewise, decreases in passive coping during the course of treatment were associated with improved performance on the 6-minute walk test, right-handed standing reach test, and most QOL indicators. Conclusion: Findings suggest that those who adopt an active approach (and avoid taking a passive approach) to rehabilitation following complex musculoskeletal injury benefit along both QOL and functional dimensions relative to those who do not. (PsycINFO Database Record (c) 2011 APA, all rights reserved)