Deciding when to lend a helping hand: a decision-making framework for seabird island restoration

Following the removal of an introduced species, island restoration can follow two general approaches: passive, where no further intervention occurs and the island is assumed to recover naturally, and; active, where recovery of key taxa (e.g. seabirds) is enhanced by manipulating movement and demography. Steps for deciding between these techniques are: (1) outlining an explicit restoration goal; (2) building a conceptual model of the system; (3) identifying the most effective management approach; and (4) implementing and monitoring outcomes. After decades of island restoration initiatives, retrospective analysis of species’ responses to active and passive management approaches is now feasible. We summarize the advantages of incorporating these analyses of past restoration results as an initial step in the decision-making process. We illustrate this process using lessons learned from the restoration of seabird-driven island ecosystems after introduced vertebrate eradication in New Zealand. Throughout seven decades of successful vertebrate eradication projects, the goals of island restoration have shifted from passive to active enhancement of island communities, which are heavily dependent on burrow-nesting petrel population recovery. Using a comparative analysis of petrel response to past predator eradications we built a conceptual model of petrel recovery dynamics and defined key site and species characteristics for use in a stepwise decision tree to select between active or passive seabird population management. Active restoration techniques should be implemented when seabird populations are absent or declining; and on islands with no nearby source colony, small remnant colonies, highly altered habitat with shallow soil and slopes, and with competitive species pairs. As we continue to restore complex island communities, decision-making tools using a logical, step-wise framework informed by previous restoration successes and failures can aid in increasing understanding of ecosystem response.     

Atomic force microscopy: a powerful tool to observe biomolecules at work

Atomic force microscopes (AFMs) move a sharp tip attached to a soft cantilever in a TV-raster-like pattern over a surface and record deflections of the tip that correspond to the surface topography. When operated in physiological solutions, an AFM allows biomolecules to be observed in their native environment. Progress in instrumentation, sample-preparation methods and recording conditions has provided images of biomolecules and their assemblies that reveal submolecular details. In addition, the AFM allows conformational changes to be observed directly. This article discusses these points and illustrates them with some pertinent examples.     

Deciding group movements: Where and when to go

A group of animals can only move cohesively, if group members “somehow” reach a consensus about the timing (e.g., start) and the spatial direction/destination of the collective movement. Timing and spatial decisions usually differ with respect to the continuity of their cost/benefit distribution in such a way that, in principle, compromises are much more feasible in timing decision (e.g., median preferred time) than they are in spatial decisions. The consequence is that consensus costs connected to collective timing decisions are usually less skewed amongst group members than are consensus costs connected to spatial decisions. This, in turn, influences the evolution of decision sharing: sharing in timing decisions is most likely to evolve when conflicts are high relative to group cohesion benefits, while sharing in spatial decisions is most likely to evolve in the opposite situation. We discuss the implications of these differences for the study of collective movement decisions.     

Who is eating what: diet assessment using next generation sequencing

The analysis of food webs and their dynamics facilitates understanding of the mechanistic processes behind community ecology and ecosystem functions. Having accurate techniques for determining dietary ranges and components is critical for this endeavour. While visual analyses and early molecular approaches are highly labour intensive and often lack resolution, recent DNA-based approaches potentially provide more accurate methods for dietary studies. A suite of approaches have been used based on the identification of consumed species by characterization of DNA present in gut or faecal samples. In one approach, a standardized DNA region (DNA barcode) is PCR amplified, amplicons are sequenced and then compared to a reference database for identification. Initially, this involved sequencing clones from PCR products, and studies were limited in scale because of the costs and effort required. The recent development of next generation sequencing (NGS) has made this approach much more powerful, by allowing the direct characterization of dozens of samples with several thousand sequences per PCR product, and has the potential to reveal many consumed species simultaneously (DNA metabarcoding). Continual improvement of NGS technologies, on-going decreases in costs and current massive expansion of reference databases make this approach promising. Here we review the power and pitfalls of NGS diet methods. We present the critical factors to take into account when choosing or designing a suitable barcode. Then, we consider both technical and analytical aspects of NGS diet studies. Finally, we discuss the validation of data accuracy including the viability of producing quantitative data.     

How to have an effective academic sabbatical: recommendations for what to do and what to avoid

Sabbaticals - i.e., academic sabbaticals, sabbatical leaves, sabbatical semesters - provide faculty members with a unique opportunity to engage in scholarly projects. Ranging from a year to shorter periods, these time windows - usually free of rigid day-to-day obligations - can be powerful means to reflect on past and present projects, to renew perspectives, and to receive fresh impetus for both your research and teaching. When reading the literature on sabbaticals, it is somewhat surprising that relatively small amounts of space are devoted to this important part of academic life. Here we provide practical recommendations [1-4: pre-sabbatical; 5-8: intra-sabbatical; 9-10: post-sabbatical] for making your sabbatical a satisfying endeavor.     

Opening Remarks: Thinking and Deciding

SYNOPSIS. Apart from providing students with the fundamentalconcepts and some of the data supporting these concepts, anintroductory university course in biology should suggest waysof thinking about important human problems that relate to biology.Most of these problems such as abortion, genetic engineering,right to life, environmental pollution, and overuse of naturalresources, have no single solution that will be accepted byall people. Science cannot specify what the solution shouldbe—that must be a human choice. However, the data andprocedures of science can be invaluable in helping human beingsmake informed choices and, once a choice has been made, makemore probable the achieving of the desired goal.     

Deciding Not to Decide: Computational and Neural Evidence for Hidden Behavior in Sequential Choice

Understanding the cognitive and neural processes that underlie human decision making requires the successful prediction of how, but also of when, people choose. Sequential sampling models (SSMs) have greatly advanced the decision sciences by assuming decisions to emerge from a bounded evidence accumulation process so that response times (RTs) become predictable. Here, we demonstrate a difficulty of SSMs that occurs when people are not forced to respond at once but are allowed to sample information sequentially: The decision maker might decide to delay the choice and terminate the accumulation process temporarily, a scenario not accounted for by the standard SSM approach. We developed several SSMs for predicting RTs from two independent samples of an electroencephalography (EEG) and a functional magnetic resonance imaging (fMRI) study. In these studies, participants bought or rejected fictitious stocks based on sequentially presented cues and were free to respond at any time. Standard SSM implementations did not describe RT distributions adequately. However, by adding a mechanism for postponing decisions to the model we obtained an accurate fit to the data. Time-frequency analysis of EEG data revealed alternating states of de- and increasing oscillatory power in beta-band frequencies (14–30 Hz), indicating that responses were repeatedly prepared and inhibited and thus lending further support for the existence of a decision not to decide. Finally, the extended model accounted for the results of an adapted version of our paradigm in which participants had to press a button for sampling more information. Our results show how computational modeling of decisions and RTs support a deeper understanding of the hidden dynamics in cognition.     

利用蚕豆根观察植物有丝分裂

洋葱因取材方便、发根条件简单、染色体数目少（2n=16）,因此常作为有丝分裂实验的首选材料^[1]。但由于菜农在采收洋葱后会喷洒一种植物保鲜剂—青鲜素（MH）,这就阻碍了洋葱发根。根据笔者的发现,春季（3、4月）洋葱发根根多,其他时间发根根非常少^[2],因此对开展此实验,取材在时间上受到限制,但若采用蚕豆根尖,可避免此问题,