Evolutionary search for understanding movement dynamics on mixed networks

This paper describes an approach to using evolutionary algorithms for reasoning about paths through network data. The paths investigated in the context of this research are functional paths wherein the characteristics (e.g., path length, morphology, location) of the path are integral to the objective purpose of the path. Using two datasets of combined surface and road networks, the research demonstrates how an evolutionary algorithm can be used to reason about functional paths. We present the algorithm approach, the parameters and fitness function that drive the functional aspects of the path, and an approach for using the algorithm to respond to dynamic changes in the search space. The results of the search process are presented in terms of the overall success based on the response of the search to variations in the environment and through the use of an occupancy grid characterizing the overall search process. The approach offers a great deal of flexibility over more conventional heuristic path finding approaches and offers additional perspective on dynamic network analysis.     

Obtaining a durable power of attorney for health care from nursing home residents

BACKGROUND: A durable power of attorney for health care (DPA) allows a person to appoint a surrogate decision-maker for any future period of mental incapacity. The absence of advance directives can lead to confusion and the expenditure of resources while trying to exert a substituted judgment. METHODS: The Wisconsin DPA was presented with an organized pilot program to 150 residents who had been judged by their social workers to have the capacity to make informed decisions regarding medical care. The reasons residents gave for accepting or rejecting a DPA were analyzed. RESULTS: Seventy-nine percent prepared a DPA. Reasons for signing included allowing the resident to decide who would make medical decisions and assuring that specific wishes would be carried out. Twenty-one percent did not execute a DPA. Reasons were categorized as confusion and misunderstanding regarding the legal system, mistrust, or social isolation. CONCLUSIONS: The high rate (79%) of DPA completion is probably related to individually counseling residents. However, competent residents who despite counseling do not choose to execute a DPA can have detailed advance directives ("living wills") prepared without appointing a decision-maker.     

Arsenic and selenium capture by fly ashes at low temperature

Arsenic and selenium compounds may be emitted to the environment during coal conversion processes, although some compounds are retained in the fly ashes, in different proportions depending on the characteristics of the ashes and process conditions. The possibility of optimizing the conditions to achieve better trace element retention appears to be an attractive, economical option for reducing toxic emissions. This approach requires a good knowledge of fly ash characteristics and a thorough understanding of the capture mechanism involved in the retention. In this work the ability of two fly ashes, one produced in pulverized coal combustion and the other in fluidized bed combustion, to retain arsenic and selenium compounds from the gas phase in coal combustion and coal gasification atmospheres was investigated. To explore the possible simultaneous retention of mercury, the influence of the unburned coal particle content was also evaluated. Retention capacities between 2 and 22 mg g(-1) were obtained under different conditions. The unburned coal particle content in the fly ash samples does not significantly modify retention capacities.     

Defining dimensions of distinctiveness: Group variability makes a difference to differentiation.

We tested the prediction, derived from an integration of social identity and self-categorization principles, that the relation between in-group distinctiveness and positive differentiation is curvilinear. Moderate distinctiveness is argued to provide the critical combination of intergroup difference (self-categorization theory) and intergroup similarity ( social identity theory ) to elicit intergroup differentiation. Intergroup distance (differences in group central tendencies) and group variability were manipulated orthogonally, resulting in different levels of intergroup distinctiveness (low, intermediate, and high). In line with predictions, in-group bias and positive differentiation were greatest, for both minimal and natural groups, when the combination of group variability and intergroup distance produced intermediate levels of group distinctiveness. The potential of this integrative model to account for disparate findings is discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A 600 MWe pulsed tokamak reactor

The choice of parameters for a pulsed tokamak reactor with net electrical output of 600 MW_e is considered. The physics and engineering assumptions are described in detail with particular emphasis on the magnetic field design. This leads to reactor parameters with 2 m minor radius, an aspect ratio of 3.9, and energy multiplication factorQ of 13. The sensitivity of the chosen parameters to various changes in the assumptions is analyzed. A comparison is made with a recent study of the reversed field pinch reactor, showing that the two containment systems appear to have similar potential as fusion power sources.     

Theorizing the concept and role of assurance in information systems security

Assurance has different meanings, depending on the source, audience, and interpretation. We applied institutional theory and the Capability Maturity Model to conceptualize assurance: its symbolic aspects to gain social acceptance, and its substantive aspects to improve organizational capability and effectiveness in performing IS security risk management (SRM). An empirical study examined assurance-seeking behavior and outcomes for regulatory compliance. Some degree of process maturity in SRM was found necessary for producing convincing verbal accounts and compliance evidence. Findings suggest that unless an organization's assurance claims are based on achieving Level 4 maturity, assurance will be based more on symbolism than effectiveness.     

LEARNING AND VERIFYING SAFETY CONSTRAINTS FOR PLANNERS IN A KNOWLEDGE‐IMPOVERISHED SYSTEM

We present a Bayesian approach to learning flexible safety constraints and subsequently verifying whether plans satisfy these constraints. Our approach, called the Safety Constraint Learner/Checker (SCLC), infers safety constraints from a single expert demonstration trace and minimal background knowledge, and applies these constraints to the solutions proposed by multiple planning agents in an integrated and heterogeneous ensemble. The SCLC calculates how much to blame plan fragments (partial solutions) generated by the individual planning agents. This information is used when composing these fragments into a final overall plan. In particular, fragments whose safety violations exceed a threshold are rejected. This facilitates the generation of safe plans. We have integrated the SCLC within the Generalized Integrated Learning Architecture, which was designed for Defense Advanced Research Projects Agency (DARPA)’s Integrated Learning (IL) program. The main goal of the IL program is to promote the development and success of sophisticated systems that learn to solve challenging real‐world problems based on a simple demonstration by a human expert and exiguous domain knowledge. We present experimental results showing the advantages of the SCLC on two multiagent problem‐solving tasks that were benchmark applications in DARPA’s IL program.     

Studies on anti-inflammatory agents. V. Synthesis and pharmacological properties of 3-(difluoromethyl)-1-(4-methoxyphenyl)-5- [4-(methylsulfinyl)phenyl]pyrazole and related compounds

A series of novel 1,5-diphenylpyrazole derivatives bearing hydrophilic substituents was prepared. The anti-inflammatory and analgesic activities of these compounds were evaluated by using the adjuvant arthritis and Randall-Selitto assays in rats, and the structure-activity relationships were studied. The optimal compound was 3-(difluoromethyl)-1-(4-methoxyphenyl)-5-[4-(methylsulfinyl)phenyl]pyraz ole (10) with oral ED50 values of 0.31 and 2.6 mg/kg on adjuvant-induced arthritis and carrageenin-induced foot edema, respectively. Compound 10 showed analgesic activities not only toward inflamed paw but also toward normal paw (ED30 = 0.55 and 1.8 mg/kg, respectively) in the Randall-Selitto assay, and moreover, 10 was effective in the tail-pinch assay (ED50 = 21 mg/kg) similarly to morphine. The asymmetric synthesis and pharmacological properties of the enantiomers of 10 are also reported.     

High thermoelectric figures of merit in PbTe quantum wells

High-quality Pb_1−xEu_xTe/PbTe multiple quantum wells (MQWs) have been grown by molecular beam epitaxy. The measured 300K thermoelectric properties have been compared with that of the best bulk PbTe. This experimental investigation is the first detailed study of MQW structures designed to improve ZT of thermoelectric materials and has resulted in a breakthrough in the decades-long ZT ≅ 1 barrier for a room-temperature thermoelectric material. A value of Z_2DT >1.2 has been achieved for these PbTe quantum wells.     

Biased Language Use in Stereotype Maintenance: The Role of Encoding and Goals.

In 4 studies, the authors investigated the relative impact of biased encoding of information and communication goals on biased language use. A category label (linguistic expectancy bias, Study 1) or a group label (linguistic intergroup bias, Study 2) was presented either before or after a story that participants were asked to communicate. Biased language use only emerged when participants learned about the group membership of the actor or the category label before hearing the story. However, communication goals had an effect on language use at the retrieval stage, independent of encoding (Studies 3 and 4). Although communication goal effects seemed to overwhelm encoding effects, encoding still influenced language use under externally imposed time pressure (Study 3) and self-imposed time constraints (Study 4). This research reaffirms the importance of both cognitive and communicative processes in stereotype maintenance and highlights the conditions under which they each operate. (PsycINFO Database Record (c) 2010 APA, all rights reserved)