Forced retroevolution of an RNA bacteriophage

The operator hairpin ahead of the replicase gene in RNA bacteriophage MS2 contains overlapping signals for binding the coat protein and ribosomes. Coat protein binding inhibits further translation of the gene and forms the first step in capsid formation. The hairpin sequence was partially randomized to assess the importance of this structure element for the bacteriophage and to monitor alternative solutions that would evolve on the passaging of mutant phages. The evolutionary reconstruction of the operator failed in the majority of mutants. Instead, a poor imitation developed containing only some of the recognition signals for the coat protein. Three mutants were of particular interest in that they contained double nonsense codons in the lysis reading frame that runs through the operator hairpin. The simultaneous reversion of two stop codons into sense codons has a very low probability of occurring. Therefore the phage solved the problem by deleting the nonsense signals and, in fact, the complete operator, except for the initiation codon of the replicase gene. Several revertants were isolated with activities ranging from 1% to 20% of wild type. The operator, long thought to be a critical regulator, now appears to be a dispensable element. In addition, the results indicate how RNA viruses can be forced to step back to an attenuated form.

The return of the Prince of Denmark: a survey on recent developments in the economics of innovation

It is well known that innovation is the engine that drives the growth machine of modern capitalist economies. Therefore, not surprisingly, substantial attention has been devoted by economists to the process behind the production of innovations. Three areas have recently emerged as relevant in the field. These are: the impact of spillovers on productivity; the different forms of R&D cooperation and the role of patents in fostering innovations when these are cumulative. In this paper I summarise the relevant literature in these three areas by discussing where the current literature stands and what are its future developments.

Soliton generation from randomly modulated return-to-zero pulses

We consider return-to-zero (RZ) pulses with random phase modulation propagating in a nonlinear channel (modelled by the integrable nonlinear Schrödinger equation, NLSE). We suggest two different models for the phase fluctuations of the optical field: (i) Gaussian short-correlated fluctuations and (ii) generalized telegraph process. Using the rectangular-shaped pulse form we demonstrate that the presence of phase fluctuations of both types strongly influences the number of solitons generated in the channel. It is also shown that increasing the correlation time for the random phase fluctuations affects the coherent content of a pulse in a non-trivial way. The result obtained has potential consequences for all-optical processing and design of optical decision elements.

All-optical passive quasi-regeneration in transoceanic 40 Gbit/s return-to-zero transmission systems with strong dispersion management

A method of all-optical passive quasi-regeneration in transoceanic 40 Gbit/s return-to-zero transmission systems with strong dispersion management was described. The use of in-line nonlinear optical loop mirrors (NOLM) by the method was demonstrated. The quasi-regeneration of signals performed by NOLMs was found to improve the systems's performance.

Angel grants employees their wish – for time off in return for high performance:new breed of incentives based on what staff really want from their employer

Purpose – Describes a new breed of HR strategies that encourage employee involvement and commitment as part of high-performance working (HPW). Design/methodology/approach – Focuses on managing employee attitudes and skills through careful attention to leadership, reward and job-design policies. Highlights the differences between people's formal employment contracts and their less formal “psychological contracts”, and emphasizes the importance of the latter. Provides a case study of UK recruitment consultancy Angel Services Group Ltd, which allows staff who meet their daily targets to go home an hour early. Findings – Urges companies to have processes in place to understand the needs of individual employees. This can be done through leadership policies that require all supervisors and managers not only to manage their staff but also to know them as people. Practical implications – Emphasizes that organizations need to see HPW initiatives as part of the normal way of managing people, and not as “flavour of the month”. Originality/value – Outlines a wide range of initiatives that could help organizations to gain their employees' commitment.

Deficient inhibition of return in subclinical OCD only when attention is directed to the threatening aspects of a stimulus

Background - Inhibition of return (IOR) is thought to reflect inhibition of previously attended but irrelevant stimuli. Deficient IOR would increase the likelihood of revisiting previously searched locations or objects, thus leading to unproductive perseverations. Method - Therefore, using a novel IOR task, we investigated whether high scoring checkers attentional biases to threat would result in dysfunctional inhibitory functioning compared to low checkers. In two tasks, we compared 53 subclinical high and 49 low checkers regarding IOR effects for stimuli that were concordant with the concerns of high but not of low checkers (electrical kitchen appliances: e.g., toaster, kettle). The difference between the two tasks was the cueing procedure. In one task, an appliance was switched “ON” and “OFF” as an unpredictive cue, drawing attention to the functionality of the stimulus. Results - In this task, IOR was specifically attenuated in high checkers. In the other task, however, the cue was more abstract in form of a yellow outline that appeared around one of two appliances. Although the appliance was either “ON” or “OFF,” this did not seem to matter and high checkers revealed a typical IOR pattern similar to low checkers. Conclusions - We conclude that IOR mechanisms might not be generally deficient in high checkers; rather only when attention is drawn to the threatening aspects of ecologically valid stimuli, then disengagement of attention is deficient in high checkers. We make suggestions on how our task-specific findings may inform cognitive interventions that target attentional control in the treatment of checking/obsessive–compulsive disorder.

Inhibition of object identity in inhibition of return:implications for encoding and retrieving inhibitory processes

Inhibition of return (IOR) effects, in which participants detect a target in a cued box more slowly than one in an uncued box, suggest that behavior is aided by inhibition of recently attended irrelevant locations. To investigate the controversial question of whether inhibition can be applied to object identity in these tasks, in the present research we presented faces upright or inverted during cue and/or target sequences. IOR was greater when both cue and target faces were upright than when cue and/or target faces were inverted. Because the only difference between the conditions was the ease of facial recognition, this result indicates that inhibition was applied to object identity. Interestingly, inhibition of object identity affected IOR both whenencoding a cue face andretrieving information about a target face. Accordingly, we propose that episodic retrieval of inhibition associated with object identity may mediate behavior in cuing tasks.

Portfolio size, non-trading frequency and portfolio return autocorrelation

In this paper we re-examine the relationship between non-trading frequency and portfolio return autocorrelation. We show that in portfolios where security specific effects have not been completely diversified, portfolio autocorrelation will not increase monotonically with increasing non-trading, as indicated in Lo and MacKinlay (1990). We show that at high levels of non-trading, portfolio autocorrelation will become a decreasing function of non-trading probability and may take negative values. We find that heterogeneity among the means, variances and betas of the component securities in a portfolio can act to increase the induced autocorrelation, particularly in portfolios containing fewer stocks. Security specific effects remain even when the number of securities in the portfolio is far in excess of that considered necessary to diversify security risk. © 2014 Elsevier B.V.

The rise and fall of diasporic bonds in Japanese-Peruvian “Return” migration

Two decades after Japanese-Peruvians and other South Americans of Japanese descent began to migrate back to Japan, the return-migration phenomenon has ended. Induced by the Japanese government in the name of shared ethnicity, Japanese policymakers now largely regard return migration as a failed policy. It failed because return-migrants did not, in the view of policy- makers, assimilate, integrate, or “make it” in Japan as expected. Thus, once-imagined ethnic bonds ceased to exist in Japan. However, ethnic bonds sustained themselves well outside Japan. The Japanese-Peruvian community in Peru has thrived and maintained continuous ties with Japan. What explains the rise and fall of diasporic ethnic bonds? Drawing on my ethnographic research in Japanese-Peruvian communities in Peru and Japan, I found that diasporic ethnic bonds are cultivated or weakened depending upon where diasporic populations are located in relation to their ancestral homeland, and how such ties are utilized, for what, and by whom.