Blood and tissue compatibility of modified polyester: thrombosis, inflammation, and healing

OBJECTIVE: The effects of BRL-32872, azimilide and a selective blocker of the delayed rectifier potassium current, E-4031, were measured at two different basic cycle lengths (BCL), 300 and 1000 ms. Calcium channel antagonists of sarcolemmal (verapamil and nitrendipine) and sarcoplasmic reticulum (ryanodine) membranes were used to investigate whether the inhibition of the calcium current or the calcium release from the sarcoplasmic reticulum could alter the reverse-rate dependence of E-4031 on action potential duration (APD). METHODS: Guinea pig isolated papillary muscles were superfused with a Tyrode solution maintained at 37 degrees C and stimulated at a BCL of 300 or 1000 ms. The standard microelectrode technique was used to record action potential parameters and to study the effects of azimilide, BRL-32872 and E-4031. E-4031 was superfused at increasing concentrations (0.01, 0.03, 0.1 and 0.3 microM) in the absence or in the presence of verapamil (0.3 microM), nitrendipine (0.03 microM) or ryanodine (0.1 microM). RESULTS: BRL-32872 and azimilide induced a self-limited concentration-dependent increase in APD. The effect of BRL-32872 was not dependent on the stimulation frequency whereas the effect of azimilide was significantly reduced at the shorter BCL. E-4031 induced a concentration-dependent increase in APD at both stimulation BCL. The increase in APD was significantly more pronounced in fibres stimulated at a BCL of 1000 ms than in fibres stimulated at a BCL of 300 ms, characterising the reverse-frequency dependent effect of class III antiarrhythmic agents. The reverse-frequency dependence in action potential prolongation induced by E-4031 was significantly reduced in the presence of a low concentration of verapamil (0.3 microM), nitrendipine (0.03 microM), or ryanodine (0.1 microM. CONCLUSION: The results show that BRL-32872, in contrast to azimilide, does not induce the reverse-rate dependency of action potential prolongation typically produced by class III antiarrhythmic agents such as E-4031. Our results also show that reverse-rate dependency induced by E-4031 can be reduced by the simultaneous administration of a low concentration of a calcium channel antagonist or an inhibitor of the release of calcium from the sarcoplasmic reticulum. It is thus suggested that compounds with a suitable balance of potassium and calcium antagonistic activities may have less adverse effects than purely selective potassium channel blockers.     

The essential Gcd10p-Gcd14p nuclear complex is required for 1-methyladenosine modification and maturation of initiator methionyl-tRNA

Gcd10p and Gcd14p are essential proteins required for the initiation of protein synthesis and translational repression of GCN4 mRNA. The phenotypes of gcd10 mutants were suppressed by high-copy-number IMT genes, encoding initiator methionyl tRNA (tRNAiMet), or LHP1, encoding the yeast homolog of the human La autoantigen. The gcd10-504 mutation led to a reduction in steady-state levels of mature tRNAiMet, attributable to increased turnover rather than decreased synthesis of pre-tRNAiMet. Remarkably, the lethality of a GCD10 deletion was suppressed by high-copy-number IMT4, indicating that its role in expression of mature tRNAiMet is the essential function of Gcd10p. A gcd14-2 mutant also showed reduced amounts of mature tRNAiMet, but in addition, displayed a defect in pre-tRNAiMet processing. Gcd10p and Gcd14p were found to be subunits of a protein complex with prominent nuclear localization, suggesting a direct role in tRNAiMet maturation. The chromatographic behavior of elongator and initiator tRNAMet on a RPC-5 column indicated that both species are altered structurally in gcd10Delta cells, and analysis of base modifications revealed that 1-methyladenosine (m1A) is undetectable in gcd10Delta tRNA. Interestingly, gcd10 and gcd14 mutations had no effect on processing or accumulation of elongator tRNAMet, which also contains m1A at position 58, suggesting a unique requirement for this base modification in initiator maturation.     

Distributed formation control with relaxed motion requirements

Heterogeneous formation shape control with interagent bearing and distance constraints involves the design of a distributed control law that ensures the formation moves such that these interagent constraints are achieved and maintained. This paper looks at the design of a distributed control scheme to solve different formation shape control problems in an ambient two‐dimensional space with bearing, distance and mixed bearing and distance constraints. The proposed control law allows the agents in the formation to move in any direction on a half‐plane and guarantees that despite this freedom, the proposed shape control algorithm ensures convergence to a formation shape meeting the prescribed constraints. This work provides an interesting and novel contrast to much of the existing work in formation control where distance‐only constraints are typically maintained and where each agent's motion is typically restricted to follow a very particular path. A stability analysis is sketched, and a number of illustrative examples are also given. Copyright © 2014 John Wiley & Sons, Ltd.     

K-winner networks.

A special class of mutually inhibitory networks is analyzed, and parameters for reliable K-winner performance are presented. The network dynamics are modeled using interactive activation, and results are compared with the sigmoid model. For equal external inputs, network parameters that select the units with the larger initial activations (the network converges to the nearest stable state) are derived. Conversely, for equal initial activations, networks that select the units with larger external inputs (the network converges to the lowest energy stable state) are derived. When initial activations are mixed with external inputs, anomalous behavior results. These discrepancies are analyzed with several examples. Restrictions on initial states are derived which ensure accurate K-winner performance when unequal external inputs are used.     

Parallel interval-based reasoning in medical knowledge-based system Clinaid

The paper continues a series of papers and a monograph [33], where we have described the conceptual structures as well as the basic architecture of a knowledge-based systemCunaid.     

How users perceive and respond to security messages: a NeuroIS research agenda and empirical study

Users are vital to the information security of organizations. In spite of technical safeguards, users make many critical security decisions. An example is users’ responses to security messages – discrete communication designed to persuade users to either impair or improve their security status. Research shows that although users are highly susceptible to malicious messages (e.g., phishing attacks), they are highly resistant to protective messages such as security warnings. Research is therefore needed to better understand how users perceive and respond to security messages. In this article, we argue for the potential of NeuroIS – cognitive neuroscience applied to Information Systems – to shed new light on users’ reception of security messages in the areas of (1) habituation, (2) stress, (3) fear, and (4) dual-task interference. We present an illustrative study that shows the value of using NeuroIS to investigate one of our research questions. This example uses eye tracking to gain unique insight into how habituation occurs when people repeatedly view security messages, allowing us to design more effective security messages. Our results indicate that the eye movement-based memory (EMM) effect is a cause of habituation to security messages – a phenomenon in which people unconsciously scrutinize stimuli that they have previously seen less than other stimuli. We show that after only a few exposures to a warning, this neural aspect of habituation sets in rapidly, and continues with further repetitions. We also created a polymorphic warning that continually updates its appearance and found that it is effective in substantially reducing the rate of habituation as measured by the EMM effect. Our research agenda and empirical example demonstrate the promise of using NeuroIS to gain novel insight into users’ responses to security messages that will encourage more secure user behaviors and facilitate more effective security message designs.     

When Deceitful Chats Look Truthful

The amount of deception taking place via electronic text-based communication is increasing. Research has sought to automatically detect deception by analyzing the text from the communicator. However, the deceptive intent of the communication partner is being ignored. We compare the text from subjects who are trying to deceive each other, subjects trying to deceive truth tellers, subjects telling the truth to truth tellers, and subjects telling the truth to deceivers. We hypothesize that despite the intent of the partner, deceitful text will cluster closest to deceitful text. We cluster each of the four conditions using the text content. The cluster algorithm placed subjects trying to deceive each other closest to subjects telling the truth to each other. In this analysis, the language that led subjects to choose the same outcomes had a stronger effect than the language tied to being deceitful or truthful.