Performance analysis of interferometric noise due to unequally powered interferers in optical networks

Interferometric crosstalk has been identified as the cause of performance limits in future transparent all-optical networks. A large number of studies have been conducted on this phenomenon using a vast array of evaluation techniques. However, most major studies have considered that although the interfering terms may differ in number, the power contribution that they all make will be identical for all interfering terms. Although this situation is easy to analyze, it does not necessarily represent the situation that is likely to occur in a real network, which will be constructed of nodes with different degrees of connectivity, quite possibly from different vendors, and therefore with differing crosstalk characteristics. This paper describes a study on the impact of unequally powered interfering terms using a rigorous analysis technique. To validate the use of the chosen technique, the paper begins by bench-marking a number of common evaluation techniques against empirically derived, experimentally verified noise performance formulas

The propositional nature of human associative learning

The past 50 years have seen an accumulation of evidence suggesting that associative learning depends oil high-level cognitive processes that give rise to propositional knowledge. Yet, many learning theorists maintain a belief in a learning mechanism in which links between mental representations are formed automatically. We characterize and highlight the differences between the propositional and link approaches, and review the relevant empirical evidence. We conclude that learning is the consequence of propositional reasoning processes that cooperate with the unconscious processes involved in memory retrieval and perception. We argue that this new conceptual framework allows many of the important recent advances in associative learning research to be retained, but recast in a model that provides a firmer foundation for both immediate application and future research

A case study of argumentation at undergraduate level in history

This article examines two essays by undergraduate students in the first year of study in History at a university in the UK. It also draws on documentary evidence from the department in question and interviews with the students themselves to paint a picture of the way argumentation operates at this level. While no firm conclusions can be drawn, the evidence suggests a department with a high degree of awareness of the importance of argument and argumentation in studying History; and students who are aware and articulate about the problem facing them in constructing essays in the discipline. Suggestions are made about induction into the epistemological and argumentative demands of undergraduate study

Outcome predictability biases learning.

Much of contemporary associative learning research is focused on understanding how and when the associative history of cues affects later learning about those cues. Very little work has investigated the effects of the associative history of outcomes on human learning. Three experiments extended the "learned irrelevance" paradigm from the animal conditioning literature to examine the influence of an outcome's prior predictability on subsequent learning of relationships between cues and that outcome. All 3 experiments found evidence for the idea that learning is biased by the prior predictability of the outcome. Previously predictable outcomes were readily associated with novel predictive cues, whereas previously unpredictable outcomes were more readily associated with novel nonpredictive cues. This finding highlights the importance of considering the associative history of outcomes, as well as cues, when interpreting multistage designs. Associative and cognitive explanations of this certainty matching effect are discussed

Intention insertion: Activating an action's perceptual consequences is sufficient to induce non-willed motor behavior

An R script which reproduces the analyses described in the published pape

Evidence of a Goal-Directed Process in Human Pavlovian-Instrumental Transfer

© 2017 APA, all rights reserved). Cues that signal rewards can motivate reward-seeking behaviors, even for outcomes that are not currently desired. Three experiments examined this phenomenon, using an outcome-selective Pavlovian-instrumental transfer (PIT) design and an outcome devaluation procedure. In Experiment 1, participants learned to perform one response to earn crisps points and another response to earn popcorn points. One outcome was then devalued by adulterating it to make it taste unpleasant. On test, overall response choice was biased toward the outcome that had not been devalued, indicating goal-directed control. Stimuli that signaled crisps and popcorn also biased instrumental response choice toward their respective outcomes (a PIT effect). Most importantly, the strength of this bias was not influenced by the devaluation manipulation. In contrast, Experiment 2 demonstrated that when stimuli signaled equal probability of the two outcomes, cue-elicited response choice was sensitive to the devaluation manipulation. Experiment 3 confirmed this conclusion by demonstrating a selective avoidance of the cued, devalued outcome. Together, these data support a goal-directed model of PIT in which expected outcome probability and value make independent contributions to response choice. (PsycINFO Database Recor

Attention and associative learning in humans: An integrative review

This article presents a comprehensive survey of research concerning interactions between associative learning and attention in humans. Four main findings are described. First, attention is biased toward stimuli that predict their consequences reliably (learned predictiveness). This finding is consistent with the approach taken by Mackintosh (1975) in his attentional model of associative learning in nonhuman animals. Second, the strength of this attentional bias is modulated by the value of the outcome (learned value). That is, predictors of high-value outcomes receive especially high levels of attention. Third, the related but opposing idea that uncertainty may result in increased attention to stimuli (Pearce & Hall, 1980), receives less support. This suggests that hybrid models of associative learning, incorporating the mechanisms of both the Mackintosh and Pearce-Hall theories, may not be required to explain data from human participants. Rather, a simpler model, in which attention to stimuli is determined by how strongly they are associated with significant outcomes, goes a long way to account for the data on human attentional learning. The last main finding, and an exciting area for future research and theorizing, is that learned predictiveness and learned value modulate both deliberate attentional focus, and more automatic attentional capture. The automatic influence of learning on attention does not appear to fit the traditional view of attention as being either goal-directed or stimulus-driven. Rather, it suggests a new kind of “derived” attention

Soy protein ingestion results in less prolonged p70S6 kinase phosphorylation compared to whey protein after resistance exercise in older men

Background The phosphorylation of p70S6 Kinase (p70S6K) is an important step in the initiation of protein translation. p70S6K phosphorylation is enhanced with graded intakes of whey protein after resistance exercise. Soy protein ingestion results in lower muscle protein synthesis after exercise compared with whey; however, the underlying mechanisms responsible for this difference have not been reported. Findings 13 older men (60–75) completed an acute bout of lower body resistance exercise and ingested 30 g of soy protein or carbohydrate. Muscle biopsies were obtained in the rested and fasted state and 2 and 4 hours post exercise. Phosphorylation status of p70S6K was measured with western blot. Results were compared with previously reported data from the ingestion of 30 g of whey protein or placebo. p70S6K phosphorylation was increased 2, but not 4 hours post exercise with soy protein ingestion. p70S6K phosphorylation was not increased post exercise with carbohydrate ingestion. Conclusions Ingesting 30 g of either whey or soy protein resulted in equivalent p70S6K phosphorylation at 2 hours post exercise, however, unlike whey, soy protein failed to promote prolonged phosphorylation of p70S6K to 4 hours post-exercise

Socially sensitive lactation: Exploring the social context of breastfeeding

Many women report difficulties with breastfeeding and do not maintain the practice for as long as intended. Although psychologists and other researchers have explored some of the difficulties they experience, fuller exploration of the relational contexts in which breastfeeding takes place is warranted to enable more in-depth analysis of the challenges these pose for breastfeeding women. The present paper is based on qualitative data collected from 22 first-time breastfeeding mothers through two phases of interviews and audio-diaries which explored how the participants experienced their relationships with significant others and the wider social context of breastfeeding in the first five weeks postpartum. Using a thematic analysis informed by symbolic interactionism, we develop the overarching theme of ‘Practising socially sensitive lactation’ which captures how participants felt the need to manage tensions between breastfeeding and their perceptions of the needs, expectations and comfort of others. We argue that breastfeeding remains a problematic social act, despite its agreed importance for child health. Whilst acknowledging the limitations of our sample and analytic approach, we suggest ways in which perinatal and public health interventions can take more effective account of the social challenges of breastfeeding in order to facilitate the health and psychological well-being of mothers and their infants