Modeling expert problem solving in a game of chance: a Yahtzee© case study

Although developments on software agents have led to useful applications in automation of routine tasks such as electronic mail filtering, there is a scarcity of research that empirically evaluates the performance of a software agent versus that of a human reasoner, whose problem-solving capabilities the agent embodies. In the context of a game of a chance, namely Yahtzee©, we identified strategies deployed by expert human reasoners and developed a decision tree for agent development. This paper describes the computer implementation of the Yahtzee game as well as the software agent. It also presents a comparison of the performance of humans versus an automated agent. Results indicate that, in this context, the software agent embodies human expertise at a high level of fidelity.     

Sex, Age, and Training Modulate Spatial Memory in the Rhesus Monkey (Macaca mulatta).

The authors tested 90 rhesus monkeys (Macaca mulatta) on a task of spatial memory, the spatial Delayed Recognition Span Test. The results showed that performance declined significantly with age, males had greater scores than females, and the rate of apparent decline with age was greater in males than in females. Both working and reference memory declined with age, but only working memory showed sex differences. The authors compared these data with that of 22 monkeys who were trained on a simpler version of the task before formal testing. Training had no effect on males but dramatically improved working memory in young females. The results confirm a male advantage in spatial working memory at a young age and confirm a greater decline with age in males than in females. It is important to note that prior training completely reverses the deficits of young females. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Predicting change for individual psychotherapy clients on the basis of their nearest neighbors.

This study extended client-focused research by using the nearest neighbor (NN) approach, a client-specific sampling and prediction strategy derived from research on alpine avalanches. Psychotherapy clients (N = 203) seen in routine practice settings in the United Kingdom completed a battery of intake measures and then completed symptom intensity ratings before each session. Forecasts of each client's rate of change and session-by-session variability were computed on the basis of that client's NNs (n = 10-50 in different comparisons). Alternative forecasts used linear or log-linear slopes and were compared with an alternative prediction strategy. Results showed that the NN approach was superior to the alternative model in predicting rate of change, though the advantage was less clear for predicting variability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conversational Collaborative Recommendation – An Experimental Analysis

Traditionally, collaborative recommender systems have been based on a single-shot model of recommendation where a single set of recommendations is generated based on a user’s (past) stored preferences. However, content-based recommender system research has begun to look towards more conversational models of recommendation, where the user is actively engaged in directing search at recommendation time. Such interactions can range from high-level dialogues with the user, possibly in natural language, to more simple interactions where the user is, for example, asked to indicate a preference for one of k suggested items. Importantly, the feedback attained from these interactions can help to differentiate between the user’s long-term stored preferences, and her current (short-term) requirements, which may be quite different. We argue that such interactions can also be beneficial to collaborative recommendation and provide experimental evidence to support this claim.     

CX3CL1 Action on Microglia Protects from Diet-Induced Obesity by Restoring POMC Neuronal Excitability and Melanocortin System Activity Impaired by High-Fat Diet Feeding

Both hypothalamic microglial inflammation and melanocortin pathway dysfunction contribute to diet-induced obesity (DIO) pathogenesis. Previous studies involving models of altered microglial signaling demonstrate altered DIO susceptibility with corresponding POMC neuron cytological changes, suggesting a link between microglia and the melanocortin system. We addressed this hypothesis using the specific microglial silencing molecule, CX3CL1 (fractalkine), to determine whether reducing hypothalamic microglial activation can restore POMC/melanocortin signaling to protect against DIO. We performed metabolic analyses in high fat diet (HFD)-fed mice with targeted viral overexpression of CX3CL1 in the hypothalamus. Electrophysiologic recording in hypothalamic slices from POMC-MAPT-GFP mice was used to determine the effects of HFD feeding and microglial silencing via minocycline or CX3CL1 on GFP-labeled POMC neurons. Finally, mice with hypothalamic overexpression of CX3CL1 received central treatment with the melanocortin receptor antagonist SHU9119 to determine whether melanocortin signaling is required for the metabolic benefits of CX3CL1. Hypothalamic overexpression of CX3CL1 increased leptin sensitivity and POMC gene expression, while reducing weight gain in animals fed an HFD. In electrophysiological recordings from hypothalamic slice preparations, HFD feeding was associated with reduced POMC neuron excitability and increased amplitude of inhibitory postsynaptic currents. Microglial silencing using minocycline or CX3CL1 treatment reversed these HFD-induced changes in POMC neuron electrophysiologic properties. Correspondingly, blockade of melanocortin receptor signaling in vivo prevented both the acute and chronic reduction in food intake and body weight mediated by CX3CL1. Our results show that suppressing microglial activation during HFD feeding reduces DIO susceptibility via a mechanism involving increased POMC neuron excitability and melanocortin signaling.     

Dynamic Strain Aging of Nickel-Base Alloys 800H and 690

The objective of the current investigation is to characterize the dynamic strain aging (DSA) behavior in alloys 800H and 690. Constant extension rate tests were conducted at strain rates in the range of 10^?4 s^?1 to 10^?7?s^?1and temperatures between 295?K and 673?K (22?°C and 400?°C), in an argon atmosphere. Maps for the occurrence of serrated flow as a function of strain rate and temperature were built for both alloys. The enthalpy of serrated flow appearance of alloy 800H was found to be 1.07?±?0.30?eV.     

Residents' preferences for private amenities and trade-offs associated with various spatial densities and patterns

ABSTRACT

Northwest Arkansas planning policies, like a number of communities across the country, have identified goals working toward more sustainable, livable, and subsequently denser development patterns. However, the understanding of residents’ perceptions of such living arrangements is limited. This study provides a more nuanced understanding of Northwest Arkansas residents’ spatial preferences through a survey of residents’ preferences for private amenities and their trade-off with various spatial densities and patterns in support of sustainability. Results of the survey indicate a preference for, and experience with, single-family residential living arrangements and amenities, with the preponderance (80%) of survey respondents currently living in single-family housing. There is a preference for low-density neighborhoods even if it means sacrificing other amenities. This study is in alignment with previous research suggesting that people may learn to prefer where they live. Additionally, while the majority of survey respondents indicated a preference for communal greenspaces, renters are more likely to prefer communal greenspaces when compared to homeowners. This study indicates that attached, multi-family development and renter development in Northwest Arkansas should consider the provision of communal green spaces, walkable access to transit, and walkable access to services as desired amenities for those residents.     

Comparing GC–MS,HPLC and H NMR analysis of beef longissimus dorsi tissue extracts to determine the effect of suspension technique and ageing

Beef longissimus dorsi muscle samples matured over a 21 day period were analysed using three different analytical techniques; ¹H NMR, GC–MS and HPLC. The data from the three experimental techniques were correlated with each other to determine if the results were statistically similar to each other. From our analysis we determined that the metabolites measured using ¹H NMR were statistically similar to the compounds quantified using the chromatography techniques (p < 0.001). In addition, using PCA, we were able to show that different metabolites, measured using the various analytical techniques produced very similar scores and loadings plots for all the analysis and extraction techniques undertaken across the 21 day time domain. Using a combination of these three different techniques provides a unique and holistic insight into the biochemistry behind the conversion of muscle to meat which would not be possible using any single technique alone.