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This chapter considers the long-term outcomes of exotic bird establishment in terms of the propensity for evolution in exotic bird populations. It shows that exotic birds have occasionally lost substantial amounts of genetic variation via the introduction process, but that just as many (if not more) populations have not lost genetic variation. It is difficult to pin down the influence that the loss or gain of genetic variation has on establishment success; this is a research area that is ripe for exploration.

Unlike all of the previous chapters, this one is devoted to low-dimensional semiconductor structures (quantum wells, quantum wires and quantum dots-nanocrystals). Basic classification of these structures is outlined and densities of electronic states are described. A detailed theoretical treatment of electronic states and exciton effects in quantum wells, both with infinite and finite barriers, is presented in effective-mass approximation. Strong and weak quantum confinement limits are discussed. Selection rules for optical transitions in quantum wells are outlined and optical absorption and emission spectra are compared. Specificity of exciton behaviour is stressed. Quantum dots with spherically symmetric potential are described in strong and weak quantum confinement regime. Salient luminescence features of quantum dots are summarized and illustrated via typical examples. Briefly mentioned are other interesting luminescence-related phenomena: phonon bottleneck, excitons indirect in real space, enhancement of nano-luminescence by metal nanoparticles and exciton multiplication.

Visual input is processed in parallel in the early stages of the visual system. Later, object recognition processes are also massively parallel, matching a visual object with a vast array of stored representation. A tight bottleneck in processing lies between these stages. It permits only one or a few visual objects at any one time to be submitted for recognition. That bottleneck limits performance on visual search tasks when an observer looks for one object in a field containing distracting objects. Guided Search is a model of the workings of that bottleneck. It proposes that a limited set of attributes, derived from early vision, can be used to guide the selection of visual objects. The bottleneck and recognition processes are modeled using an asynchronous version of a diffusion process. The current version (Guided Search 4.0) captures a range of empirical findings.

This chapter evaluates the mental time estimation hypothesis which proposes that timing might be subject to a discrete central attentional bottleneck and timing cannot take place until certain operations have finished. The chapter reviews the evidence for a central attentional bottleneck and discusses its relevance to the study of timing under conditions of divided attention. The findings refute the suggestion that timing is wholly subject to the same discrete central bottleneck as other types of effortful mental processes.

This chapter offers a model in which there is no limit to the amount of activation available, with the possibility of multiple distinct activations. However limitations arise if there are too many representations active at one time, leading to competition and interference, and a requirement for an inhibitory process for activations that are not relevant for the task in hand. It suggests that efficiency of inhibitory function might offer a major source of individual differences in working memory capacity. It also suggests that at any one time there is a set of activations that are readily accessible, and there is a subset of these that are in the focus of attention. it is specific about competition between activations for the focus of attention. This last concept is described as a processing bottleneck.

The attentional blink (AB) phenomenon can be succinctly defined as an increase in the difficulty of reporting a second (masked) target that follows (after a short delay) a first target that required immediate processing. This chapter reviews evidence supporting the view that the AB phenomenon results from a bottleneck in the information-processing stream required to perform tasks designed to reveal the AB phenomenon. The chapter is organized into six sections. The first four describe a major prediction of bottleneck models of dual-task interference, followed by relevant evidence from AB and related paradigms. The fifth section reviews evidence pertinent to the issue of the locus of the bottleneck in the AB phenomenon. The last section presents some conclusions.

Humans often experience difficulty when asked to perform multiple tasks at the same time. Two of the better-known forms of dual-task interference are the attentional blink (AB) effect and the Psychological Refractory Period (PRP) effect. These phenomena have traditionally been studied independently, using divergent methodologies and different dependent measures. This chapter aims to explore the possibility that these dual-task phenomena might reflect the same underlying processing limitation — a central bottleneck. It also discusses how AB and PRP effects are related to other phenomena such as repetition blindness and movements of spatial attention across visual space.

The economic dynamism since the late 1980s of the south China manufacturing region has been founded on a regional history of tenacious social and economic ties between two societies adopting opposing systems of political economy—a colony of Britain claimed by some as the haven of laissez-faire capitalism and its neighboring Chinese province ruled by one of the world's largest socialist states. These connections have survived more than a century of political changes and international transfers of sovereignty. The change in China's strategy of national economic development from self-reliance to an emphasis on active absorption of foreign investment coincided with the emergence of bottlenecks in Hong Kong's economy, particularly the shortage of cheap labor for its labor-intensive export production. It was east-west commerce in that period that made Canton (today's Guangzhou) and Hong Kong the bones of contention between the Chinese and foreign interests led by the British.

We’re all familiar with the truism “It’s not what you know, it’s who you know.” Managers invariably use their personal contacts when they need to, say, meet an impossible deadline, get advice on a strategic decision, or learn the truth about a new boss. Increasingly, it’s through these informal networks—not just through traditional organizational hierarchies— that information is found and work gets done. Social networks can be powerful political tools as well; few managers can resist the temptation to use their connections to discredit business initiatives they dislike or to support proposals they favor. Most corporations, however, treat informal networks as an invisible enemy—one that keeps decisions from being made and work from getting done. To many senior executives, these intricate webs of communication are unobservable and ungovernable—and, therefore, not amenable to the tools of scientific management. As a result, executives tend to work around informal networks or, worse, try to ignore them. When they do acknowledge the networks’ existence, executives fall back on intuition— scarcely a dependable tool—to guide them in nurturing this social capital. It doesn’t have to be that way. It is entirely possible to develop informal networks systematically. In fact, our research suggests that if senior managers focus their attention on a handful of key role-players in the group, the effectiveness of any informal network can be enhanced. After analyzing informal networks at more than 50 large organizations over the past five years, we’ve identified four common role-players whose performance is critical to the productivity of any organization. First, there are central connectors, who link most people in an informal network with one another. They aren’t usually the formal leaders within a unit or department, but they know who can provide critical information or expertise that the entire network draws on to get work done. Then there are boundary spanners, who connect an informal network with other parts of the company or with similar networks in other organizations. They take the time to consult with and advise individuals from many different departments—marketing, production, or R&D, for instance—regardless of their own affiliations.

Over the past decade, significant restructuring efforts have resulted in organizations with fewer hierarchical levels and more permeable internal and external boundaries. A byproduct of these restructuring efforts is that coordination and work increasingly occur through informal networks of relationships rather than through channels tightly prescribed by formal reporting structures or detailed work processes. For example, informal networks cutting across core work processes or holding together new product development initiatives are not found on formal organizational charts. Rather, these networks often promote organizational flexibility, innovation, and efficiency, as well as quality of products or services, by virtue of effectively pooling unique expertise. Supporting collaboration and work in these informal networks is increasingly important for organizations competing on knowledge and an ability to innovate and adapt. Unfortunately, critical informal networks often compete with and are fragmented by such aspects of organizations as formal structure, work processes, geographic dispersion, human resource practices, leadership style, and culture. This is particularly problematic in knowledge-intensive settings where management is counting on collaboration among employees with different types of expertise. People rely very heavily on their network of relationships to find information and solve problems—one of the most consistent findings in the social science literature is that who you know often has a great deal to do with what you come to know. Yet both practical experience and scholarly research indicate significant difficulty in getting people with different expertise, backgrounds, and problemsolving styles to effectively integrate their unique perspectives. Simply moving boxes on an organizational chart is not sufficient to ensure effective collaboration among high-end knowledge workers. Movement toward de-layered, flexible organizations and emphasis on supporting collaboration in knowledge-intensive work has made it increasingly important for executives and managers to attend to informal networks within their organizations. Performance implications of effective informal networks can be significant as the rapidly growing social capital tradition has indicated at the individual, team, and organizational levels. Yet while research indicates ways managers can influence informal networks at both the individual and whole network levels, executives seem to do relatively little to assess and support critical, but often invisible, informal networks in organizations.

Clinical trial processes are what we repeatedly do in clinical research, but, unfortunately, the habit of excellence is not as prevalent as it might be. Processes are only as good as the ways in which they are carried out, so this aspect is worth looking at before examining the processes themselves. Excellence means the very best that is achievable in a given situation with the knowledge and resources available, and it is not to be confused with perfection, which is rarely attainable, and trying to achieve it is a waste of time. Although the rational implementation of the various approaches described later can help to make the clinical development process significantly more efficient, this will not in itself achieve excellence. Implementation needs to take place in a cultural, intellectual, and operational environment that lends the necessary support. There are many possible components of such an environment, but one can go far by • instituting some basic behavioral elements; • doing things as well as they can be done all the time; • simplifying processes; • not allowing regulations to develop into liabilities. I have included this section risking that it might be considered unnecessary and patronizing by some. After all, everybody believes that their behavior is impeccable, just as everybody is a perfect driver. It only takes a few people to behave badly to poison an organization (or to injure others). . . . Laws control the lesser man. Right conduct controls the greater one. . . . . . .—Chinese proverb. . . . . .Good behavior is the last refuge of mediocrity.. . . . . . —Henry S. Haskins, stockbroker who was expelled for alleged misconduct and published his aphorisms anonymously. . . Can principles be applied that encourage positive, ethical, complex, and intelligent behavior without retreating into the lowest common denominator of mediocrity? One can argue the extent to which principles can help to achieve these objectives, but what is undeniable is that, in their absence, the results can be extremely damaging. This is exemplified not only by the poor performance metrics but also by the poor reputation of the pharmaceutical industry in the public’s view.

This chapter introduces the reader to the profound cultural paradox at the heart of this book: that mobility—particularly transnational migration—is both a cherished collective value and an increasingly restricted and impossible goal for the majority of Dakar’s residents. Beginning with the anthropologist’s story of “arrival” in the field, the introduction considers the urban embouteillage as a tangible expression of this paradox and as a critical indigenous framework for making sense of its contradictory effects on urban life and policy. The chapter does three things: It familiarizes the reader with the concept of the bottleneck and its everyday uses. It reflects on the challenges and opportunities offered by ethnographic research in this volatile context. It elaborates the bottleneck as an instance and site of infrastructural overload; a gendered experience of citizenship; an everyday bureaucratic reality after structural adjustment; and a critical vantage point for writing about Africa’s worldliness.

Accompanying cab drivers as they move along the city’s emergent highways and neglected side roads, this chapter considers what citizenship and governance look like for many urban residents in an era of intense urban construction and infrastructural impasse. The chapter argues that the traffic bottleneck indexed deep concerns about the suspension of lives and itineraries, but it also offered unexpected strategies and occasions for recuperating the meantime—for elaborating networks, hatching plans, revising legitimate practices, and claiming identities that helped bridge the inescapable present with far-off, mobile futures. In doing so, the chapter positions taxi drivers’ experiences and perspectives as normative rather than derivative, alternative, or contrary to official visions for the city. It thus works toward developing the embouteillage as a critical ethnographic framework for thinking about the paradoxes of contemporary urban belonging in Dakar more broadly.

The conclusion considers the adaptability and utility of the concept of embouteillage at other moments and in other places. It first argues that the bottleneck remained a culturally relevant and analytically powerful way of understanding life and policy in Dakar after the road projects were complete and the traffic has eased. It then moves beyond the African continent to ask how the concept of embouteillage might help us understand predicaments of governance, authority, and belonging unfolding on other terrains. Focusing in particular on bottlenecked lives and landscapes in the United States in the time of the Great Recession and widespread housing foreclosures, this chapter considers embouteillage as a framework that is at once expressly Senegalese and surprisingly flexible and adaptable. In doing so, the conclusion explores the generative possibilities that are opened up when insights gathered in Dakar are centralized as a normative and productive standard for understanding life lived elsewhere.

The main theme of the chapter revolves around the notion of “monster,” both in its biological and social dimensions, in order to explain the processes that eventually brought about the appearance of modern humans, conceptualized in two basic steps. The first step would correspond to the appearance and subsequent consolidation of a developmental monstrosity in the mind/brain of a subpopulation of hominids. Such a monstrosity, just a would-be FL at this stage, would initially have had a negative impact by turning these individuals into social monsters in the eyes of their conspecifics, with the effect of generating a reproductive barrier and thus opening the way to a process of speciation. The process would only culminate with the advent of a number of environmental circumstances giving rise to a population bottleneck, altering the genetic makeup of the population, and favoring the preservation of the original developmental monstrosity.

Major transitions involving different species or unrelated members of the same species (egalitarian transitions) are always cooperative, with both partners retaining the ability to reproduce. Only transitions involving relatives (fraternal transitions) can be altruistic, with one partner losing its ability to reproduce. The stability of social groups relies on their members having a coincidence of fitness interests, which occurs via either shared reproductive fate (in non-relatives) or shared genes (in relatives). Conflict resolution within groups, which serves to alleviate the tragedy of the commons, occurs through two broad mechanisms. The first is self-limitation, e.g., when relatedness to other group members decreases individual selfishness; and the second is coercion. A life cycle with a bottleneck (e.g., development from a single cell) increases relatedness and hence reduces potential conflict, whereas a life cycle without a bottleneck (e.g., development from a group of cells) reduces relatedness and hence increases potential conflict.

Chapter 4 discusses how the immediacy of language processing provides a fundamental constraint on theories of language acquisition and evolution. Language happens in the here-and-now. Because memory is fleeting, new material will rapidly obliterate previous material, creating a Now-or-Never bottleneck. To successfully deal with the continual deluge of linguistic information, the brain must compress and recode its input into “chunks” as rapidly as possible. It must deploy all available information predictively to ensure that local linguistic ambiguities are dealt with Right-First-Time; once the original input is lost, there is no way to recover it. Similarly, language learning must also occur in the here-and-now. This implies that language acquisition involves learning how to process linguistic structure, rather than inducing a grammar. Incoming language is recoded incrementally into chunks of increasing granularity, from sounds to constructions, and beyond. Importantly, several key properties of language follow naturally from this perspective, including the local nature of linguistic dependencies, the quasi-regular nature of linguistic structure, multiple levels of linguistic representation, and duality of patterning (i.e., that meaningful units are composed of smaller elements).