bluuebunny/crossref_metadata_2025 huggingface dataset:
Adolescent Aggression and the Media
Authors: Levesque Roger J.R.
Published: April 2010

This chapter explores the nature of media violence and its particular influence on adolescents and their development. It shows the immense power the media potentially plays in adolescent development, including the power not only to shape aggressive and violent dispositions but also to address violence and foster non-violent relationships. To introduce the media's socializing force, the chapter also pays attention to factors that moderate and mediate media effects, although research only recently has turned to these considerations. That is, it considers the factors that shape how the media influences adolescents, since the media does not act alone. Together, findings reveal the need to reconsider how best to prepare adolescents to respond to violent media.
Regulating Speech
Authors: Levesque Roger J.R.
Published: April 2010

This chapter begins by examining how the law regulates everyone's speech, speech for adults as well as adolescents. These analyses reveal an expanding protection of free speech rights, much of which directly involves media and informational environments. After detailing the rationales for protecting speech, it examines the key limits the Constitution places on speech. The limits are important to consider given that they provide the ultimate standard on which to judge everyone's free speech. Importantly, the chapter continues and examines often ignored aspects of free speech jurisprudence, such as the right to information.
The School Climate for Lesbian, Gay, Bisexual, and Transgender (LGBT) Students
Authors: Russell Stephen T. , McGuire Jenifer K.
Published: April 2010

Schools are a critical development context for adolescents. Most research focuses on individual students and their development, but a focus on the climate of schools is crucial for analyzing policy innovations as well as student wellbeing. This chapter focuses on the school experiences of lesbian, gay, bisexual, and transgender (LGBT) students, a group for whom school safety is a pressing concern. Drawing from Rogers' (2003) theory of diffusion of innovation, it identifies planned, structural changes in school policies that create positive change in school LGBT climates and for LGBT students. It discusses strategies for measuring individual- and school-level safety and climate, and provides empirical illustrations. The chapter concludes with a discussion of contemporary policy innovations and advocacy efforts that are consistent with an emphasis on improving school climates.
Altering Patterns of Relationship and Participation: Youth Organizing as a Setting-Level Intervention
Authors: Speer Paul W.
Published: April 2010

Youth-focused community organizing — a process of developing leadership and building power for young people with the goal of creating change — provides a valuable context for understanding setting-level interventions. Collective activity, a focus on issues directly impacting youth, research and analysis of the cause of problems faced, and efforts to exert power to change conditions creating the identified problem, characterize youth organizing. Drawing on the model of a national organizing network, this chapter describes an approach to altering the pattern of relationships among youth within a setting. By altering the specific pattern of connections among youth in various settings, important outcomes are expected to emerge regarding both youth participation and their capacity to affect external environments. Through the use of network analysis, the magnitude and type of setting change can be measured. Examples of youth organizing outcomes and implications for conceptualizing setting-level interventions are provided.
The Ethnic System of Supplementary Education: Nonprofit and For-Profit Institutions in Los Angeles’ Chinese Immigrant Community
Authors: Zhou Min
Published: April 2010

Informal social settings outside of school are as important as formal educational settings for children's learning and achievement. In the United States, informal settings are often organized by ethnicity and socioeconomic status in order to mediate the processes of individual learning, which consequently leads to intergroup differences in educational outcomes. This chapter examines how a particular type of informal social setting is created and structured by the ethnic community in order to generate resources for school success. By looking specifically into the non-profit and for-profit institutions serving young children and youth in Los Angeles' Chinese immigrant community, the chapter describes an ethnic system of supplementary education that not only offers tangible support but also reinforces cultural norms in pushing immigrant children to succeed in school. It is shown that the kind of informal social setting to which Chinese immigrant children are exposed is not necessarily intrinsic to a specific culture, but results from a national-origin group's migration selectivity, the strength of a pre-existing ethnic community, and the host society's reception. National-origin groups that constitute a significant middle class with valuable resources (i.e. education, job skills, and financial assets), upon arrival in the United States, have a leg-up in the race to move ahead in their new homeland, while others lacking group resources trail behind. Educators and policymakers should be careful not to attribute school success or failure merely to culture or to structure, but to the culture—structure interaction.
Socioeconomic School Integration
Authors: Kahlenberg Richard D.
Published: April 2010

In recent years, a growing number of school districts have tried to shape the social setting of the school by implementing student assignment policies to reduce concentrations of school poverty. This chapter describes the research underlying socioeconomic school integration programs, including the finding that integration by socioeconomic status matters more to student achievement than does racial integration. It offers a theory of how to create economic integration in schools through choice and incentives rather than compulsion; articulates the ingredients of successful socioeconomic integration plans; describes how to measure the degree of economic school integration and its success or failure; outlines exemplars of efforts to create economic school integration; and considers the current status of the literature and promising future directions.
The Co-Construction of Educational Reform: The Intersection of Federal, State, and Local Contexts
Authors: Datnow Amanda
Published: April 2010

This chapter offers a theory of how district, state, and federal contexts jointly shape the success of educational reform efforts at the school level. In order to describe the “co-construction” perspective of reform implementation, it examines data from a multiple case study of a current reform movement, data-driven decision making. An analysis of data reveals that implementation is a system-wide activity, even when the desired change is mainly at the school level. However, the various policy levels have varying degrees of influence, and varying levels of connection with each other, depending on local circumstances. Implications for policy, practice, and the further study of the “co-construction” of educational reform are discussed. It is argued that examining the co-construction of reform and the linkages across the educational system would likely provide insights which could inform the fields of educational research, policy development, and evaluation.
Using Community Epidemiologic Data to Improve Social Settings: The Communities that Care Prevention System
Authors: Fagan Abigail A. , Hawkins J. David , Catalano Richard F.
Published: April 2010

This chapter describes the Communities That Care (CTC) program using examples from 12 communities implementing CTC as part of an efficacy trial. CTC is a community-based strategy that empowers members of a diverse and broad-based coalition to plan, implement and monitor prevention activities intended to promote positive youth development. CTC implementation involves six structured training workshops provided over 6-12 months and the collection of epidemiologic data including an anonymous, school-wide survey of students. When implemented community-wide, the survey allows coalition members to identify the most elevated risk factors and depressed protective factors experienced by youth. The coalition then selects evidence-based prevention policies and programs that target these factors in the major settings affecting young people: schools, families, community service organizations, and the community itself. Communities monitor program implementation and periodically re-administer the youth survey in order to gauge the effectiveness of their efforts.
Well-Being for Public Policy
Authors: Diener Ed , Lucas Richard , Schimmack Ulrich , Helliwell John
Published: April 2010

The case is made for implementing national accounts of well-being to help policy makers and individuals make better decisions. Well-being is defined as people's evaluations of their lives, including concepts such as life satisfaction and happiness, and is similar to the concept of “utility” in economics. Measures of well-being in organizations, states, and nations can provide people with useful information. Importantly, accounts of well-being can help decision makers in business and government formulate better policies and regulations in order to enhance societal quality of life. Decision makers seek to implement policies and regulations that increase the quality of life, and the well-being measures are one useful way to assess the impact of policies as well as to inform debates about potential policies that address specific current societal issues. This book reviews the limitations of information gained from economic and social indicators, and shows how the well-being measures complement this information. Examples of using well-being for policy are given in four areas: health, the environment, work and the economy, and social life. Within each of these areas, examples are described of issues where well-being measures can provide policy-relevant information. Common objections to using the well-being measures for policy purposes are refuted. The well-being measures that are in place throughout the world are reviewed, and future steps in extending these surveys are described. Well-being measures can complement existing economic and social indicators, and are not designed to replace them.
Chapter 5 The Well-Being Measures Are Valid
Authors: Diener Ed , Lucas Richard E. , Schimmack Ulrich , Helliwell John F.
Published: April 2010

A frequent concern about measures of well-being is that because they are subjective, they are unreliable and are subject to many types of artifacts and errors. The evidence for the validity and reliability of these measures is reviewed in this chapter, and the nature of measurement errors is discussed. The surveys of well-being are shown to be valid in predicting important outcomes such as suicide, and in correlating with other types of measures in a systematic way. Reports of well-being by respondents correlate with other types of measures such as biological assays and reports by knowledgeable informants. Although some measurement artifacts have been shown to influence the surveys of well-being, these often are not large, and the validity of the reports persists despite the measurement problems.
Chapter 7 The Desirability of Well-Being as a Guide for Policy
Authors: Diener Ed , Lucas Richard E. , Schimmack Ulrich , Helliwell John F.
Published: April 2010

Several conceptual concerns about using well-being measures to inform policy have been enunciated, and are discussed in this chapter. It is shown that well-being does not reflect a shallow form of hedonism, but instead reflects a desirable state that helps societies function more effectively. A related objection is that immoral behaviors that society cannot condone might sometimes lead to feelings of well-being. One answer to many of these objections is that both objective and subjective measures will be used in concert; that is, subjective measures will not replace the objective ones. This recognition undercuts many of the objections that have been raised. Some believe that policy makers might manipulate well-being, or, conversely, that citizens might alter their well-being responses to influence policy, and these critiques are discussed. Another issue is which types of well-being measures should be used, and it is argued that surveys should assess a number of different types of well-being.
Chapter 10 Work, the Economy, and Well-Being: Policy Examples
Authors: Diener Ed , Lucas Richard E. , Schimmack Ulrich , Helliwell John F.
Published: April 2010

Well-being has important influences on work life and the economy, which in turn have a large influence on people’s well-being. In this chapter several policy issues on which well-being findings shed light are presented. For example, the debilitating effects of unemployment on well-being are reviewed, and this is important as many economic models assume that people elect unemployment as the best way of maximizing their well-being given their current situation. The fact that unemployment has such a substantial impact on well-being indicates that minimizing it should be a policy imperative, although other considerations such as economic growth will also help shape policies in this area. Other issues that are discussed are the influence of worker satisfaction on job performance, the influence of risk sharing such as insurance on the ill-being resulting from natural disasters, and how graduated income taxes can affect the mean levels of well-being in societies.
Chapter 11 The Social Context of Well-Being: Policy Examples
Authors: Diener Ed , Lucas Richard E. , Schimmack Ulrich , Helliwell John F.
Published: April 2010

Humans are social animals, and well-being therefore depends greatly on the quality of their social world. The idea of “social capital” is the claim that societies have a valuable resource in social relationships that are characterized by trust and trustworthiness, by collaboration and cooperation, and by a broad concern about helping the group. On the flip side, social capital is reduced by corruption and crime. The social capital of societies is linked to their health and well-being, and policies that undercut social capital can be disastrous even if they further other types of goals. By tracking both social capital and well-being, policy makers can create better regulations that increase social well-being rather than interfere with it. Well-being measures also provide a method of measuring the value of public services. An example for evaluating the outcomes of a social experiment—a program in Canada to reduce unemployment by assessing well-being before and after the program intervention—has been provided.
Chapter 2 The Psychology of Civic Learning
Authors: Carpini Michael X. Delli
Published: April 2010

Citizen knowledge is important to the democratic polity, being related to, among other things, political tolerance and efficacy, political participation, and the ability to consistently connect policy views to meaningful political evaluations. However, a large body of research concludes that citizens possess low levels of factual knowledge about government and politics. Moreover, while traditional models — grounded in the normative logic of democratic theory — suggest that political learning is an active and rational process, recent research on heuristics and affect complicates these assumptions. This chapter argues that in order to advance our understanding of political knowledge, it is necessary to integrate five principal areas of research: the traditional model, heuristic models, impression-driven models, affect-based models, and models of operative knowledge.
Chapter 3 What Knowledge is of Most Worth?
Authors: Johnson Paul E.
Published: April 2010

Most research on political knowledge focuses on declarative knowledge or specific facts about politics. By contrast, this chapter posits the importance of operative knowledge action, which is comprised of: (1) the intention to achieve one or more goals that define a given civic task; (2) a process for achieving these goals; and (3) heuristics for selecting actions down a goal path. It is suggested that operative knowledge for civic action lies at the heart of many political activities and should be assessed whenever researchers attempt to infer the knowledge individuals have of the process for participating in the political life of their society. This chapter develops an argument for how operative knowledge is acquired, the contexts in which it is deployed, the mental models that initiate its use, and provides examples of heuristic elements of this knowledge that lead to civic behaviors. Finally, it proposes the concept of civic intelligence as a general rubric under which to consider different kinds of political knowledge.
Chapter 4 Shallow Cues With Deep Effects: Trait Judgments From Faces and Voting Decisions
Authors: Hall Crystal C. , Goren Amir , Chaiken Shelly , Todorov Alexander
Published: April 2010

This chapter examines the impact of rapid automatic processes in political decision making. Specifically, using a dual-process framework, it argues that individuals assess candidate competence on the basis of facial appearance, and that this can predict the outcomes of both U.S. congressional and gubernatorial elections. These judgments occur quickly, and are largely independent of controlled processes. These findings illustrate the complexity of electoral decision making in complicated information environments, and suggest that even though individuals may not realize it, they often have little control over their initial impressions. The chapter concludes by examining how these findings inform our understanding of electoral politics, political persuasion, and democratic citizenship more generally.
Chapter 10 Tolerance and the Contact Hypothesis: A Field Experiment
Authors: Green Donald P. , Wong Janelle S.
Published: April 2010

The contact hypothesis predicts that racial prejudice diminishes when whites and non-whites interact in a setting that fosters cooperation among people of equal status. This hypothesis has seldom, if ever, been tested using randomized experimentation outside the laboratory. This chapter reports the results of a randomized field experiment in which white students were randomly assigned to Outward Bound two- and three-week wilderness courses. In the control group, all the students in each course were non-Hispanic whites. In the treatment group, most of the students were non-Hispanic whites, but at least three of the participants were African-Americans. One month after completing the course, the white participants were interviewed by telephone. As expected, the group that experienced a racially heterogeneous environment expressed greater levels of tolerance than the control group. Although these findings require replication, the research design provides a template for future field-experiments examining the validity of the contact hypothesis.
Chapter 11 Racial Stereotyping and Political Attitudes: The View From Political Science
Authors: Peffley Mark , Hurwitz Jon
Published: April 2010

While political science has made effective use of research on the psychology of stereotyping, psychology has not benefited from political science in the same way. This chapter argues that the study of racial stereotypes can be improved by a mutual effort on the part of political scientists and psychologists alike to better understand and apply the methods and perspectives that dominate each discipline. Discussion focuses on three principal disciplinary contrasts. First, while psychology has typically been concerned with the processes underlying stereotypes, political science has focused on the collective sources and political consequences of stereotyping. Second, while political science could benefit from more experimentation, psychologists should implement research designs to enhance the external validity of their research. Finally, both disciplines are limited to the extent that they typically focus on the beliefs of the dominant group, and stereotyping research would benefit from a greater emphasis on the beliefs of racial minorities.
The Changing Portrayal of Adolescents in the Media Since 1950
Authors: Jamieson Patrick , Romer Daniel
Published: April 2010

Following World War II, unparalleled economic prosperity, along with the largest cohort of American youth, gave rise to a new teen market and a new media landscape defined by television and radio. These influences in turn gave rise to a youth culture that found expression in the mass media, and which emphasized the virtues of a consumerist ethos made possible by an ever-expanding economy. Advertising became a vehicle for advancing this new consumer culture that enabled youth to become a major audience for entertainment media, and which gave unprecedented voice to their interests and concerns. With the advent of the Internet, media have again afforded young people with even greater opportunities to create and disseminate their own content. This has led to a transformation in both how youth are portrayed in the media and how American culture has been influenced in turn. This book describes these changes since 1950, with a focus on the role of the mass media as both an influence on youth socialization and as an evolving expression of youth concerns. Experts from various fields of media studies discuss these changes in chapters that focus on different aspects of adolescent portrayal, including: the history of the emergence of youth culture; youth representation in popular music and music videos; increasing portrayal of health risk behaviors in popular movies, advertising, and other media since 1950; changes in portrayal of gender roles, body image, and different ethnic groups; and the role of new and evolving media such as video games and the Internet. The book concludes with a discussion of potential policy directions for ameliorating harm from problematic media content, and the potential use of media literacy and other strategies to encourage healthier adolescent development.
Adolescent Gender Role Portrayals in the Media
Authors: Walsh Jennifer L. , Ward L. Monique
Published: April 2010

Gender socialization is the process by which children and youth learn cultural norms and expectations for gender roles. Because the mass media have played an increasing role in this process, analyses of media content can reveal how youth have been influenced over time. A review of research indicates that women (including youth) have been under-represented compared to men in the mass media. Television commercials tend to emphasize women's appearance, and female characters show more deference and shyness compared to males. Music videos have tended to show men as aggressive and violent and women as affectionate and sexual. Teen magazine content for women has focused on appearance and dating since the 1950s. Magazine advertising has also emphasized female beauty and youthfulness. There has been little change in adolescent gender roles in any of these media. Exposure to these media may contribute to adolescent viewers' beliefs, attitudes, and behaviors about gender roles.
Adolescent Body Image and Eating in the Media
Authors: Harrison Kristen
Published: April 2010

Body image and eating behavior are important factors in adolescent development because they can have grave effects, including anorexia, bulimia, and obesity. Over 36% of deaths in the U.S. have recently been linked to cardiovascular disease, which has part of its origin in poor diet. From 40% to 60% of adolescent girls and women are dissatisfied with some aspect of their bodies, and media portrayals have been linked to such beliefs. Trends in media portrayal of the ideal female body indicate that she has gotten thinner while the actual weight of American and Canadian women has increased. Consistent exposure to the thin ideal may increase the risks of not just body dissatisfaction and disordered eating but also obesity, steroid use, surgery, and drug mixing. Various strategies for counteracting these trends are discussed.
From Twin Beds to Sex at Your Fingertips
Authors: Stern Susannah , Brown Jane D.
Published: April 2010

Portrayal of sex in the media has changed dramatically since 1950, with content that would have shocked a teen in 1950 hardly producing any reaction today. Nevertheless, adolescent sexual portrayal in the media reflects considerable cultural conflict, not unlike the messages that teens frequently receive, such as that they should wait to have sex even though many initiate it anyway. Quantitative content analyses of media that measure the frequency of teen sex may be misleading because many of these portrayals discourage sex or portray it as ridden with conflict. The media could present teen sexuality in a more helpful way, especially by showing greater use of contraceptives. Rather than being used to portray sexually responsible behavior, sex has been used primarily to attract and maintain audiences. The Internet may actually permit greater exposure to health-promoting information, but this remains to be seen.
An Overview of the Empirical Literature on Adolescents and Political Violence
Authors: Barber Brian K. , Schluterman Julie Mikles
Published: April 2010

This chapter presents an assessment of the available evidence in the research literature on how youth experience political violence. It focuses not only in evaluating the evidence for the empirical associations between exposure and/or involvement in political violence and aspects of adolescent functioning, but in how the research literature has chosen to measure conflict experiences and youth functioning. It begins with a detailed overview of past and current quantitative, empirical efforts to study political violence and its associations with youth functioning, and provides a review of 95 qualifying studies. It argues that the current state of research remains relatively simplistic both in scope (i.e. narrow definitions of conflict and functioning) and in findings, and offers recommendations for how research on this topic could provide a better understanding of the complexities inherent in youth experiences with political violence.
Growing Up in Israel
Authors: Slone Michelle
Published: April 2010

This chapter summarizes a multifaceted program of research on youth in Israel and Palestine. It outlines a model for the study of the effects of political violence on children and presents a summary of data derived with the use of this paradigm, which includes contrasting effects for Israeli and Palestinian youth. This political life events model enables the examination of the differing severity of exposure for children divided along different demographic categories such as age, gender, residential location, and religious adherence. Further, the scale used allows for the study of the consequences to children's mental health from exposure to differing levels of severity and for the detection of those factors that enhance resilience in coping with exposure to political violence.
Measuring Adolescent Perceived Support Amidst War and Disaster
Authors: Layne Christopher M. , Warren Jared S. , Hilton Sterling , Lin Dahai , Pašalić Alma , Fulton John , Pašalić Hafiza , Katalinski Ranka , Pynoos Robert S.
Published: April 2010

Directing attention to the Bosnian experience, this chapter focuses on the critical area of adolescent-perceived social support during war and disaster. It details the theoretically-justified development of a new multi-sector measure of social support and provides a series of tests to determine its reliability and validity. It concludes with a series of recommendations on how future research in this area should be directed, with the hope that with a more fundamental understanding of youth and political violence, and particularly the role of social support, interventions can be more clearly targeted to need.
Positive and Negative Psychosocial Functioning after Political Conflict
Authors: Barber Brian K. , Olsen Joseph A.
Published: April 2010

This chapter attempts to contribute to the growing literature on adolescents and political violence by providing a detailed assessment of the specific types of activism Palestinian adolescents engaged in during the first Intifada (in addition to the commonly explored degree of victimization). Analysis of data from several hundred Palestinian youth shows some evidence of impaired functioning associated with conflict exposure (particularly for females), but also evidence of enhanced functioning for both males and females associated with their degree of activism.
Tasting the World
Authors: Weine Stevan , Klebic Alma , Celik Adana , Bicic Mirela
Published: April 2010

This chapter focuses on Bosnian youth who survived ethnic cleansing and war, and who are living as refugees in Chicago. It presents a collaborative effort between several Bosnian youth and an American psychiatrist and scholar to document and analyze these youths' experiences with political violence. Through a series of first-person accounts and interviews, youths underscore the important point that refugee trauma for adolescents encompasses not only exposure to war and other forms of political violence, but also the experiences of social and cultural marginalization associated with displacement, exile immigration, and urbanization. A trauma bundle perspective is described that can assist in understanding how to better support teen refugees' efforts to manage enormous changes in their lives.
Dissociations of visual functions by brain lesions in human patients
Authors: JACOB PIERRE , JEANNEROD MARC
Published: April 2010

The task of the dorsal pathway is to determine the spatial layout of objects by processing their respective position in the visual field. According to the system of coordinates in which this processing is effected in the dorsal system, different outcomes are obtained. When an object's position is encoded in allocentric coordinates, its spatial position is determined relative to other objects. When it is encoded in egocentric coordinates, its spatial position is determined relative to the agent's effector and the object becomes a goal for action. Spatial localization and the visuomotor transformation are thus conceived of as two complementary functions of the dorsal pathway. This chapter examines neuropsychological evidence for similar dissociations in human visual capacities based on the examination of lesions in the human visual system. It considers the effects of lesions in the primary visual cortex, the ventral pathway, and in the dorsal pathway.
Visual perception
Authors: JACOB PIERRE , JEANNEROD MARC
Published: April 2010

This chapter examines both what can be perceived and how what can be perceived is perceived. First, it asks the question: how can visual perception provide knowledge at all? Since knowledge of the world acquired by perception depends on the identification and the recognition of objects, it examines problems raised by visual recognition. Second, it considers the question of how human vision interacts with the rest of human cognition: how is knowledge gained by visual perception integrated with knowledge gained by other means? Third, it examines the scope and limits of purely visual knowledge. Fourth, it asks the question: how intelligent are perceptual processes? Fifth, it asks whether all of one's visual experiences ought to be treated as beliefs or judgments. Finally, the chapter re-examines the puzzles of the phenomenology of human visual experience in the light of the problem of binding.
Did Primate Trichromacy Evolve for Frugivory or Folivory?
Authors: Sumner P , Mollon J. D
Published: April 2010

Two hypotheses have been proposed to explain the selective advantage of primate trichromacy. According to the frugivory hypothesis, the advantage lay in finding fruit amongst foliage. In contrast, the folivory hypothesis states that the advantage of trichromatic vision lay in the detection of reddish/brown colouration in the edible leaves of some tropical plants. This chapter considers evidence and arguments for the frugivory and folivory hypotheses. Spectroradiometric evidence is consistent with both the folivory and frugivory hypotheses, and tests of intraspecific differences in foraging success between dichromatic and trichromatic individuals are yet to be reported. Thus, there is at present no primary evidence that distinguishes between the two theories.
Spatial Contrast Sensitivity for Pulsed- and Steady-Pedestal Stimuli
Authors: Leonova Anna , Pokorny Joel , Smith Vivianne C.
Published: April 2010

This chapter evaluates spatial modulation sensitivity under conditions inferred to favour magnocellular (MC) and parvocellular (PC) pathways. Pulsed- and Steady-Pedestal Paradigms revealed characteristic differences in spatial frequency processing. Pulsed-Pedestal D6 spatial contrast sensitivity functions are mediated by the PC-pathway. Steady-Pedestal contrast sensitivity functions are mediated by the MC-pathway at low spatial frequencies, and by the PC-pathway above 4 cycles/deg. These data support the hypothesis of a major role for the PC-pathway in achromatic spatial vision.
Integration Times Reveal Mechanisms Responding to Isoluminant Chromatic Gratings: A Two-Centre Visual Evoked Potential Study
Authors: Robson A. G. , Kulikowski J. J. , Korostenskaja M. , Neveu M. M. , Hogg C. R. , Holder G. E.
Published: April 2010

Visual evoked potentials (VEPs) provide an objective technique for monitoring the integrity of visual pathways and have been used to monitor the activity of post-receptoral chromatic mechanisms. The temporal properties of visual processing may now be characterized in terms of VEP integration time, defined as the stimulus duration during which response components are summed to give the highest amplitude VEP. The onset of a luminance-modulated pattern of moderate spatial frequency elicits the largest VEP when the grating appearance is brief, i.e. about 40-60 ms, consistent with predominant activation of transient mechanisms. Likewise, the greatest amplitude chromatic VEPs are obtained with isoluminant coarse L/M gratings when the offset period exceeds the onset duration. This chapter compares L/M tritan integration times by obtaining VEP responses to the onset of two cycles per deg gratings of varying onset durations, in order to characterize the temporal response mechanisms contributing to the two chromatic processing streams.
The Influence of Rods on Colour Naming During Dark Adaptation
Authors: Nerger Janice L. , Volbrecht Vicki J. , Haase Kristin A.
Published: April 2010

Various studies have demonstrated that the effects of rods on hue judgments depend on the size and intensity of the test stimulus. Studies have also shown increased rod influence with smaller stimuli than with larger stimuli. This chapter shows that the differences in hue perception between the fovea and 8° nasal retinal eccentricity may be minimized if either the size or intensity of the stimuli presented to the peripheral retina is increased.
Colour Discrimination, Colour Constancy and Natural Scene Statistics
Authors: Macleod Donald I.A.
Published: April 2010

This chapter relates the processes of colour vision to the characteristics of the natural environment. The reference to natural scene statistics relates the two main parts of the chapter — the first five sections concerned with colour discrimination, and the seventh section concerned with colour appearance and its transformation or constancy under changes of illumination.
Middle Wavelength Sensitive Photopigment Gene Expression is Absent in Deuteranomalous Colour Vision
Authors: Neitz Maureen , Bollinger Kathryn , Neitz Jay
Published: April 2010

The deutan-type colour vision deficiencies, deuteranopia, and deuteranomaly are the most common types of colour blindness. A known cause of deutan colour vision defects is the loss of genes encoding the middle wavelength sensitive (M) photopigments. Deutan defects have also been found to be associated with a deleterious point mutation in the M photopigment genes. This chapter tests the hypothesis that M gene expression is absent in all commonly occurring deutan defects. It shows that the commonly occurring deutan defects in which individuals have normal appearing M genes, are caused by a failure to express M pigment. Moreover, it appears that the failure is likely to be complete.
Lantern Colour Vision Tests: One Light Or Two?
Authors: Hovis Jeffery K.
Published: April 2010

This chapter shows that the number of lights displayed in a lantern test is an important design consideration when validating lantern tests against a field test. Generally, the increasing number of lights increases the failure rate. This difference in pass rates for the single and paired light display suggests that some of the variability reported in studies correlating lantern tests to field tests may be due to the difference in the number of lights presented in different displays. The increased failure rate may be due to a combination of simultaneous contrast effects and simultaneous comparison of the adjacent lights.
Colour Naming, Colour Categories, and Central Colour-Coding in a Case of X-Linked Incomplete Achromatopsia
Authors: Nolan J. B. , Crognale M. A. , Webster M. A.
Published: April 2010

This chapter examines categorical colour perception and the nature of central processing of colour in a 33-year-old male with X-linked incomplete achromatopsia. Data from colour naming and categorization, colour contrast adaptation, and a battery of standard colour tests performed with and without a rod bleach, are presented. It is shown that despite colour deficiencies, the subject demonstrates consisted but shifted colour category and naming behaviour, while showing weak evidence for selectively tuned central chromatic mechanisms.
Visual Dysfunction Following Mercury Exposure By Breathing Mercury Vapour Or By Eating Mercury-Contaminated Food
Authors: Silveira Luiz Carlos L. , Damin Enira Terezinha B. , Pinheiro Maria Da ConceiÇÃO N. , Rodrigues Anderson R. , Moura Ana Laura A. , CÔRtes Maria Izabel T. , Mello Guilherme A.
Published: April 2010

This chapter examines the visual performance of Amazonian gold miners and other workers suffering from mercury poisoning. Subjects exposed to mercury displayed a variable degree of spatial vision dysfunction. Both achromatic and chromatic vision were impaired. They had lower achromatic contrast sensitivity and this effect was more pronounced in the medium spatial frequency range. Mercury exposed subjects also had lower red-green and blue-green chromatic contrast sensitivity than control subjects in all tested spatial frequencies.
Computational Molecular Evolution
Authors: Yang Ziheng
Published: April 2010

The field of molecular evolution has experienced explosive growth in recent years due to the rapid accumulation of genetic sequence data, continuous improvements to computer hardware and software, and the development of sophisticated analytical methods. The increasing availability of large genomic data sets requires powerful statistical methods to analyse and interpret them, generating both computational and conceptual challenges for the field. This book provides a comprehensive coverage of modern statistical and computational methods used in molecular evolutionary analysis, such as maximum likelihood and Bayesian statistics. It describes the models, methods and algorithms that are most useful for analysing the ever-increasing supply of molecular sequence data, with a view to furthering our understanding of the evolution of genes and genomes. The book emphasizes essential concepts rather than mathematical proofs. It includes detailed derivations and implementation details, as well as numerous illustrations, worked examples, and exercises.
Bayesian methods
Authors: YANG ZIHENG
Published: April 2010

This chapter provides a brief introduction to the theory and computation of Bayesian statistics and its applications to molecular evolution. It uses simple examples, such as distance estimation under the JC69 model, to introduce the general principles. It discusses the application of Bayesian inference to reconstruction of phylogenetic trees and to population genetics analysis under the coalescent. Exercises are provided at the end of the chapter.
Simulating molecular evolution
Authors: YANG ZIHENG
Published: April 2010

This chapter discusses basic techniques of computer simulation. Topics covered include random number generator, generation of continuous random variables, generation of discrete random variables, and simulating molecular evolution. Exercises are provided at the end of the chapter.
Human genetic variation of medical significance
Authors: Kidd Kenneth K. , Kidd Judith R.
Published: April 2010

This chapter reviews evidence on medically significant genetic variation in humans. Extensive amounts of normal genetic variation occur in humans, and every independently conceived individual is genetically unique. The distribution of genetic variation in populations is the product of a human evolutionary history that has included selection and random genetic drift influenced by migration, demography, and isolation. The major features of genetic variation in modern humans are the large amount of variation in Africa and the loss of variation in the expansion out of Africa. Against the background of allele frequency variation around the world, it is difficult to identify which loci have been subject to natural selection varying among geographic regions. That normal genetic variation can affect health in surprising and complex ways is illustrated by how metabolism and taste perception are related to alcoholism.
Perspectives on human health and disease from evolutionary and behavioral ecology
Authors: Strassmann Beverly I. , Mace Ruth
Published: April 2010

Patients are phenotypes; thus all medical conditions are a product of genes and the environment. One genotype can produce many phenotypes depending on the environments encountered. Such phenotypic plasticity promotes reproductive success by creating a better fit between the genotype and the environment. Evolutionary insights into kin selection, life history, parental investment, and sexual selection help us to understand: the origins of child abuse and homicide in step-families; deadbeat dads; attachment disorders; failure to thrive; female infanticide; excess male mortality from accidents, suicide, and disease; risky behaviour; immunosuppression; reproductive cancer; marital violence; and genital cutting. Many of these problems reflect reproductive conflicts of interest between individuals. Other conflicts occur within individuals and involve life history trade-offs. Conflicts of interest within and between individuals constrain natural selection, and prevent an optimal world wherein adaptation is maximized at all levels simultaneously.
Evolution of parasites
Authors: Koella Jacob C. , Turner Paul
Published: April 2010

We need to be able to predict how virulence will evolve under various circumstances. The simplest model of the evolution of virulence, which assumes that virulence and transmission are linked and that evolution maximizes total transmission, is a useful tool to understand the potential consequences of control strategies. Deeper understanding will take into account details of the host-parasite interactions, including how virulence is governed by the interaction of the host's and the parasite's genes, and where virulence is context-dependent. The evolution of virulence may depend on a virulence-transmission trade-off, but that trade-off may in turn depend on the host's condition or age, and trade-offs between virulence and other traits of the parasite may be more important for some parasites. Co-evolution and non-equilibrium situations, such as the emergence of a new disease, complicate matters further. Genomics and experimental evolution will produce helpful insights into host-parasite interactions.
Evolution, developmental plasticity, and metabolic disease
Authors: Kuzawa Christopher W. , Gluckman Peter D. , Hanson Mark A. , Beedle Alan S.
Published: April 2010

Early-life events influence late life health. An adverse early environment changes the developing organism's metabolism, physiology, and organ structure to increase risk of adult metabolic disorders, including the metabolic syndrome, diabetes, and cardiovascular disease. Early environmental cues initiate functionally coherent adjustments that alter energy-partitioning and modify nutritional requirements. When maternal nutritional and endocrine cues predict future environmental conditions, developmental and metabolic responses to these cues could provide a mechanism for fine-tuning responses to local environmental conditions. However, individuals faced with scarcity early in life are now increasingly confronted with abundance later in life, and the resulting mismatch between the environment early and late in life is an important contributor to patterns of human morbidity and mortality.
Clinical pharmacodynamics and pharmacokinetics of the antifungal extended‐spectrum triazole posaconazole: an overview
Authors: Lipp Hans‐Peter
Published: April 2010

In recent years, the antifungal triazole posaconazole has become increasingly important for the prophylaxis and treatment of systemic mycoses. Although oral bioavailability of posaconazole can be enhanced by concomitant food intake and administration in divided daily doses, increased gastric pH or gut motility, as well as enzyme‐inducing drugs, can result in lower plasma concentrations than expected. Whether therapeutic drug monitoring can reduce the risk of treatment failures by avoiding sub‐therapeutic plasma concentrations needs further examination. Based on the ability of posaconazole to inhibit cytochrome P450 3A4, several drug interactions can be expected, especially with agents that undergo extensive first‐pass effect through the gut and the liver. However, more information is needed regarding dose modifications during concomitant administration of posaconazole with drugs in certain categories, such as vinca alkaloids and retinoids, along with selected individual drugs such as everolimus.