Lunar navigation study, volume 2 Final report, Jan. - Dec. 1966

Performance data utilization in mission phase, lunar exploration phase, and navigational phase of lunar roving vehicle mission

Hippocampal Infusion of Zeta Inhibitory Peptide Impairs Recent, but Not Remote, Recognition Memory in Rats.

Spatial memory in rodents can be erased following the infusion of zeta inhibitory peptide (ZIP) into the dorsal hippocampus via indwelling guide cannulas. It is believed that ZIP impairs spatial memory by reversing established late-phase long-term potentiation (LTP). However, it is unclear whether other forms of hippocampus-dependent memory, such as recognition memory, are also supported by hippocampal LTP. In the current study, we tested recognition memory in rats following hippocampal ZIP infusion. In order to combat the limited targeting of infusions via cannula, we implemented a stereotaxic approach for infusing ZIP throughout the dorsal, intermediate, and ventral hippocampus. Rats infused with ZIP 3-7 days after training on the novel object recognition task exhibited impaired object recognition memory compared to control rats (those infused with aCSF). In contrast, rats infused with ZIP 1 month after training performed similar to control rats. The ability to form new memories after ZIP infusions remained intact. We suggest that enhanced recognition memory for recent events is supported by hippocampal LTP, which can be reversed by hippocampal ZIP infusion

Percolative shunting on electrified surface

The surface discharge of electrified dielectrics at high humidity is considered. The percolative nature of charge transport in electrets is established. Particular attention is given to the phenomena of adsorption and nucleation of electrically conducting phase in the cause of percolation cluster growth on electrified surface. The critical index of the correlation lenght for percolation cluster is found, and its value is in good agreement with the known theoretical estimations.Comment: 4 pages with 1 figure, revtex, published in Tech. Phys. Lett. 25 (1999) 877-879 with one additional figur

Equivalence of operator-splitting schemes for the integration of the Langevin equation

We investigate the equivalence of different operator-splitting schemes for the integration of the Langevin equation. We consider a specific problem, so called the directed percolation process, which can be extended to a wider class of problems. We first give a compact mathematical description of the operator-splitting method and introduce two typical splitting schemes that will be useful in numerical studies. We show that the two schemes are essentially equivalent through the map that turns out to be an automorphism. An associated equivalent class of operator-splitting integrations is also defined by generalizing the specified equivalence.Comment: 4 page

Optimizing prediction of binge eating episodes : a comparison approach to test alternative conceptualizations of the affect regulation model

Background : Although a wealth of studies have tested the link between negative mood states and likelihood of a subsequent binge eating episode, the assumption that this relationship follows a typical linear dose&ndash;response pattern (i.e., that risk of a binge episode increases in proportion to level of negative mood) has not been challenged. The present study demonstrates the applicability of an alternative, non-linear conceptualization of this relationship, in which the strength of association between negative mood and probability of a binge episode increases above a threshold value for the mood variable relative to the slope below this threshold value (threshold dose response model). Methods : A sample of 93 women aged 18 to 40 completed an online survey at random intervals seven times per day for a period of one week. Participants self-reported their current mood state and whether they had recently engaged in an eating episode symptomatic of a binge. Results : As hypothesized, the threshold approach was a better predictor than the linear dose&ndash;response modeling of likelihood of a binge episode. The superiority of the threshold approach was found even at low levels of negative mood (3 out of 10, with higher scores reflecting more&nbsp; negative mood). Additionally, severity of negative mood beyond this threshold value appears to be useful for predicting time to onset of a binge episode. Conclusions : Present findings suggest that simple dose&ndash;response formulations for the association between&nbsp; negative mood and onset of binge episodes miss vital aspects of this relationship. Most&nbsp; notably, the impact of mood on binge eating appears to depend on whether a threshold value&nbsp; of negative mood has been breached, and elevation in mood beyond this point may be useful&nbsp; for clinicians and researchers to identify time to onset. <br /

Factors Associated with Player Satisfaction and Educational Value of Serious Games

Computer games are well established forms of entertainment which have been shown to promote the development of important cognitive skills. This has also seen their evolution into games supporting training and education, known as serious games. In order to investigate those factors that would be important when de-veloping these types of games we conducted a two year study on undergraduate game development students. Seventy four students participated in the study. They were asked for their views on three web-based serious games (Cancer Game, Dar-fur is Dying and Elude). A series of study questionnaires were used to collect data on their playing experience, satisfaction with the games and how well they ac-quired subject specific knowledge after playing them. The students’ views on the games’ entertainment and educational value were mixed. Two games (Cancer Game and Darfur is Dying) were able to increase players’ knowledge as a result of playing them but to differing extents. Suggested improvements to the games fo-cused on providing more appropriate background information on the subject with-in the game, and giving the player better feedback on how to play it. When the re-sults were compared to existing heuristics on game development improvements to the design of the game interface, game mechanics and game playability were iden-tified. The need to incorporate learning outcomes into the games and that they be outcome based are also important pedagogical factors. In this initial study we have suggested a series of heuristics which the authors believe will be important to developers of serious games

Transport on Directed Percolation Clusters

We study random lattice networks consisting of resistor like and diode like bonds. For investigating the transport properties of these random resistor diode networks we introduce a field theoretic Hamiltonian amenable to renormalization group analysis. We focus on the average two-port resistance at the transition from the nonpercolating to the directed percolating phase and calculate the corresponding resistance exponent $\phi$ to two-loop order. Moreover, we determine the backbone dimension $D_B$ of directed percolation clusters to two-loop order. We obtain a scaling relation for $D_B$ that is in agreement with well known scaling arguments.Comment: 4 page

Lunar navigation study, sections 1 through 7 Final report, Jun. 1964 - May 1965

Lunar navigation analysis using passive nongyro, inertial navigation, and radio frequency technolog

Lunar navigation study, summary volume Final report, Jun. 1964 - May 1965

Lunar surface navigation and guidance study to implement lunar surface vehicle exploration mission