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In the second half of the 19th century, French imperial expansion in the south of the Sahara led to the control of numerous African territories. The colonial rule France imposed on a diverse range of cultural groups and political entities brought with it the development of equally diverse inquiry and research methodologies. A new form of scholarship, africanisme, emerged as administrators, the military, and amateur historians alike began to gather ethnographic, linguistic, judicial, and historical information from the colonies. Initially, this knowledge was based on expertise gained in the field and reflected the pragmatic concerns of government rather than clear, scholarly, interrogation in line with specific scientific disciplines.
Research was thus conducted in many directions, contributing to the emergence of the so-called colonial sciences. Studies by Europeans scholars, such as those carried out by Maurice Delafosse and Charles Monteil, focused on West Africa’s past. In so doing, the colonial context of the late 19th century reshaped the earlier orientalist scholarship tradition born during the Renaissance, which had formerly produced quality research about Africa’s past, for example, about medieval Sudanese states. This was achieved through the study of Arabic manuscripts and European travel narratives. In this respect, colonial scholarship appears to have perpetuated the orientalist legacy, but in fact, it transformed the themes, questions, and problems historians raised.
In the first instance, histoire coloniale (colonial history) focused the history of European conquests and the interactions between African societies and their colonizers. Between 1890 and 1920 a network of scientists, including former colonial administrators, struggled to institutionalize colonial history in metropolitan France. Academic positions were established at the Sorbonne and the Collège de France. Meanwhile, research institutions were created in French West Africa (Afrique Occidentale Française [AOF]), French Equatorial Africa (Afrique Équatoriale Française [AEF]), and Madagascar between 1900 and the 1930s.
Yet, these imperial and colonial concerns similarly coincided with the rise of what was then known as histoire indigène (native history) centered on the precolonial histories of African societies. Through this lens emerged a more accurate vision of the African past, which fundamentally challenged the common preconception that the continent had no “history.” This innovative knowledge was often co-produced by African scholars and intellectuals.
After the Second World War, interest in colonial history started to wane, both from an intellectual and a scientific point of view. In its place, the history of sub-Saharan Africa gained popularity and took root in French academic institutions. Chairs of African history were created at the Sorbonne in 1961 and 1964, held by Raymond Mauny and Hubert Deschamps, respectively, and in 1961 at the École Pratique des Hautes Études, fulfilled by Henri Brunschwig. African historians, who were typically trained in France, began to challenge the existing European scholarship. As a result, some of the methods and sources that had been born in the colonial era, were adopted for use by a new generation of historians, whose careers blossomed after the independences.
Ronald Reagan’s foreign policy legacy remains hotly contested, and as new archival sources come to light, those debates are more likely to intensify than to recede into the background. In dealings with the Soviet Union, the Reagan administration set the superpowers on a course for the (largely) peaceful end of the Cold War. Reagan began his outreach to Soviet leaders almost immediately after taking office and enjoyed some success, even if the dominant theme of the period remains fears of Reagan as a “button-pusher” in the public’s perception. Mikhail Gorbachev’s election to the post of General Secretary proved the turning point. Reagan, now confident in US strength, and Gorbachev, keen to reduce the financial burden of the arms race, ushered in a new, cooperative phase of the Cold War. Elsewhere, in particular Latin America, the administration’s focus on fighting communism led it to support human rights–abusing regimes at the same time as it lambasted Moscow’s transgressions in that regard. But even so, over the course of the 1980s, the United States began pushing for democratization around the world, even where Reagan and his advisors had initially resisted it, fearing a communist takeover. In part, this was a result of public pressure, but the White House recognized and came to support the rising tide of democratization. When Reagan left office, a great many countries that had been authoritarian were no longer, often at least in part because of US policy. US–Soviet relations had improved to such an extent that Reagan’s successor, Vice President George H. W. Bush, worried that they had gone too far in working with Gorbachev and been hoodwinked.
Urban charter schools are public schools located in major metropolitan areas with high population densities. The majority of urban charter school students identify as Black or Latinx and often live in under-resourced communities. Urban charter schools are touted as high-quality educational options in the school choice market, yet debates about the merits of charter schools versus traditional public schools yield mixed results that substantiate arguments on both sides of the political aisle.
However, even high-performing urban charter schools have a bad reputation as mechanisms of school segregation and cogs in the school-to-prison pipeline. Higher than average test scores and graduation and college enrollment rates do little to mollify those who complain about severe discipline, racial segregation, unqualified teachers, teacher attrition, rigid scheduling, and a narrow curriculum. Urban charter schools’ emphasis on standardized testing and college preparation may overlook the culturally relevant educational experiences that low-income, racially diverse students need to compete with their wealthier, White peers.
As such, education reformers have offered a myriad of suggestions to improve urban charter schools. Most prominently is the need to racially and economically desegregate urban charter schools to enhance the social and material resources that supplement students’ learning. This includes increasing teacher diversity, which research demonstrates minimizes the frequency of suspensions and expulsions of racial minority students. Urban charter school teachers should also be knowledgeable about the sociocultural landscape of the community in which their school exists so that they understand how students’ out of school lives affect their learning processes. Finally, curricular revisions are necessary to support students’ post-high school goals beyond college enrollment. Enacting such reforms would facilitate equitable, rather than equal, learning opportunities that may help narrow racial and economic achievement gaps in the United States.
Jeffrey F. Taffet
In the first half of the 20th century, and more actively in the post–World War II period, the United States government used economic aid programs to advance its foreign policy interests. US policymakers generally believed that support for economic development in poorer countries would help create global stability, which would limit military threats and strengthen the global capitalist system. Aid was offered on a country-by-country basis to guide political development; its implementation reflected views about how humanity had advanced in richer countries and how it could and should similarly advance in poorer regions. Humanitarianism did play a role in driving US aid spending, but it was consistently secondary to political considerations. Overall, while funding varied over time, amounts spent were always substantial. Between 1946 and 2015, the United States offered almost $757 billion in economic assistance to countries around the world—$1.6 trillion in inflation-adjusted 2015 dollars. Assessing the impact of this spending is difficult; there has long been disagreement among scholars and politicians about how much economic growth, if any, resulted from aid spending and similar disputes about its utility in advancing US interests. Nevertheless, for most political leaders, even without solid evidence of successes, aid often seemed to be the best option for constructively engaging poorer countries and trying to create the kind of world in which the United States could be secure and prosperous.
Benjamin Mark Sanderson
Long-term planning for many sectors of society—including infrastructure, human health, agriculture, food security, water supply, insurance, conflict, and migration—requires an assessment of the range of possible futures which the planet might experience. Unlike short-term forecasts for which validation data exists for comparing forecast to observation, long-term forecasts have almost no validation data. As a result, researchers must rely on supporting evidence to make their projections. A review of methods for quantifying the uncertainty of climate predictions is given. The primary tool for quantifying these uncertainties are climate models, which attempt to model all the relevant processes that are important in climate change. However, neither the construction nor calibration of climate models is perfect, and therefore the uncertainties due to model errors must also be taken into account in the uncertainty quantification.
Typically, prediction uncertainty is quantified by generating ensembles of solutions from climate models to span possible futures. For instance, initial condition uncertainty is quantified by generating an ensemble of initial states that are consistent with available observations and then integrating the climate model starting from each initial condition. A climate model is itself subject to uncertain choices in modeling certain physical processes. Some of these choices can be sampled using so-called perturbed physics ensembles, whereby uncertain parameters or structural switches are perturbed within a single climate model framework. For a variety of reasons, there is a strong reliance on so-called ensembles of opportunity, which are multi-model ensembles (MMEs) formed by collecting predictions from different climate modeling centers, each using a potentially different framework to represent relevant processes for climate change. The most extensive collection of these MMEs is associated with the Coupled Model Intercomparison Project (CMIP). However, the component models have biases, simplifications, and interdependencies that must be taken into account when making formal risk assessments. Techniques and concepts for integrating model projections in MMEs are reviewed, including differing paradigms of ensembles and how they relate to observations and reality. Aspects of these conceptual issues then inform the more practical matters of how to combine and weight model projections to best represent the uncertainties associated with projected climate change.
Accounts written by foreigners—especially Europeans—about what they saw in Africa constitute one of the major sources for African history between c. 1450 and c. 1900. Some were published, while others remained in manuscript form. Unlike the ethnographic monographs of the early 20th century, they were generally written in a spontaneous and unsystematic manner, usually with a narrative structure, although in some cases an implicit “questionnaire” seems to have lain behind what was recorded.
Historians of Africa must apply the rules of source criticism to such material. These include an obligation to examine the extent to which the material is really “primary” (rather than derived from sources that already existed and still exist today); what stereotypes and fixed ideas may have shaped the author’s perceptions and writing; how the expectations of the intended readership—including a desire for exoticism or sensationalism—may have influenced the content and style, in some cases even resulting in straightforward fabrication posing as authentic description; and whether the author’s personal background—for example, financial interests, ideology, or gender—could have led him or her to perceive and write about Africa in a certain way. Certain types of data contained in travel accounts, such as quantitative or linguistic information, require cautious analysis. Some travel accounts were accompanied by engravings or other iconographic material, and although it is tempting to use these simply as illustrations, they must be subjected to the same kinds of source criticism as are applied to the written accounts themselves.
Despite these caveats, travel accounts are an indispensable source, whose full potential still remains to be discovered.
Marjon van der Pol and Alastair Irvine
The interest in eliciting time preferences for health has increased rapidly since the early 1990s. It has two main sources: a concern over the appropriate methods for taking timing into account in economics evaluations, and a desire to obtain a better understanding of individual health and healthcare behaviors. The literature on empirical time preferences for health has developed innovative elicitation methods in response to specific challenges that are due to the special nature of health. The health domain has also shown a willingness to explore a wider range of underlying models compared to the monetary domain. Consideration of time preferences for health raises a number of questions. Are time preferences for health similar to those for money? What are the additional challenges when measuring time preferences for health? How do individuals in time preference for health experiments make decisions? Is it possible or necessary to incentivize time preference for health experiments?
We live in an approximately 24-hour world and circadian rhythms have evolved to adapt organisms to the opportunities presented by Earth’s 24-hour cycle of light and dark. A “master clock” located in the suprachiasmatic nucleus (SCN) of the brain orchestrates daily rhythms in all manner of behavioral, endocrine, metabolic, autonomic, and homeostatic systems in our bodies. The SCN is comprised of about 20,000 neurons and about one third as many astroglia. How can so few neurons and astroglia guide so many rhythms? How do neurons time out an interval as long as a day? The answers are a case study in understanding how genes within cells, and cells within circuits, function together to perform complex activities and optimize bodily functions. While individual clock cells are found in virtually all bodily tissues, the unique connectome of the SCN, its specialized afferent inputs from the retinohypothalamic tract, and its neural and humoral outputs enable its “babel” of neuronal types to synchronize their activity and signal time to the rest of the body.
At the molecular-cellular level, circadian rhythms are regulated by a 24-hour transcriptional–translational feedback loop. At the SCN tissue level, individual SCN neurons coordinate their gene expression and electrical activity, working together in circuits that sustain coherent rhythms. The SCN has many distinct cell types based on their neurotransmitters, neuropeptides, and afferent and efferent connections. There has been much progress in unraveling the dynamic network organization that underlies the SCN network’s communications. Though the precise anatomical connections underlying interneuronal communication in the SCN are not completely understood, key signaling mechanisms that sustain the SCN’s intrinsic rhythmicity have been tackled using intersectional genomic tools. Transgenic animals that permit the visualization of clock gene–protein expression have enabled analysis of SCN network activity over time. Availability of animals bearing mutations in clock genes or proteins enable the determination of changes within neurons, among neurons in networks, and their impact on behavior. The use of continuous readouts of circadian activity that track behavior, or clock gene expression, or electrical activity changes over time, within an SCN or a single neuron, leads the way to unraveling mechanisms sustaining the circadian timing system. Because the results of circadian studies generate huge amounts of data, the entry of mathematical modelers and statisticians into the field has begun to yield useful and testable predictions on how these multiplexed systems work to adapt to our 24-hour world.
Gerben J. Westerhof and Susanne Wurm
Aging is often associated with inevitable biological decline. Yet research suggests that subjective aging—the views that people have about their own age and aging—contributes to how long and healthy lives they will have. Subjective age and self-perceptions of aging are the two most studied aspects of subjective aging. Both have somewhat different theoretical origins, but they can be measured reliably. A total of 41 studies have been conducted that examined the longitudinal health effects of subjective age and self-perceptions of aging. Across a wide range of health indicators, these studies provide evidence for the longitudinal relation of subjective aging with health and longevity. Three pathways might explain this relation: physiological, behavioral, and psychological pathways. The evidence for behavioral pathways, particularly for health behaviors, is strongest, whereas only a few studies have examined physiological pathways. Studies focusing on psychological pathways have included a variety of mechanisms, ranging from control and developmental regulation to mental health. Given the increase in the number of older people worldwide, even a small positive change in subjective aging might come with a considerable societal impact in terms of health gains.
Angela L. Bos, Heather Madonia, and Monica C. Schneider
Stereotypes are a set of beliefs a person holds about the personal attributes of a group of people. The beliefs are commonly held and understood, which allows people to use them as automatic shortcuts when making evaluations and decisions. Because the beliefs are so broadly understood and easily accessible, they can subconsciously influence opinion formation. In the realm of politics, citizens may use stereotypes to guide evaluations of candidates from stereotyped groups (such as African Americans or women) or as they formulate opinions about a policy that may have a particular group as its perceived beneficiary.
Because many commonly held stereotypes—such as that African Americans are lazy or violent—are not socially desirable, they pose a challenge to researchers attempting to measure them effectively. Thus, as social scientists examine the effects of stereotypes on citizen decision-making, it is important that they carefully consider how to best measure stereotypes. The goal should be to create reliable (consistent) and valid (accurate) measures that minimize social desirability in responses. Measures should reflect clear understanding of the content of the stereotype under examination and incorporate a full range of content to reflect it. One part of understanding the content of a stereotype is considering whether the group under examination is a subtype or subgroup of a larger stereotype category. For example, female politicians as a group constitute a subtype of the larger stereotyped group, women, where female politicians share little overlap in terms of stereotype content with women. Similarly, Black politicians are a subtype of Blacks, sharing little stereotype content. Male politicians, in contrast, form a subgroup of men, where they share many characteristics with the larger group, men. Stereotype content has implications for the link between stereotypes and evaluations of political actors or public policies. The ability to accurately measure stereotypes is a necessary step in understanding when and how people use stereotypes to navigate the political arena.
The intersection of two stereotypes is another important consideration, particularly since the combination of two stereotypes may be more than the sum of its parts. When researchers consider the content of stereotypes, the relationship between one stereotype to others (e.g., subtypes or subgroups), and the intersection of stereotypes, they can create improved measures of stereotypes that optimize reliability and validity.
A variety of explicit and implicit measures exist for researchers to consider, including explicit measures, such as semantic differential scales and open- and closed-ended identification of stereotype content, and implicit measures, such as the Implicit Association Test (IAT) and affective attitude measures. Two-step measures can be used to examine stereotype activation and application. While each of these measures has strengths and weaknesses, all are designed to help researchers better measure stereotypes en route to understanding how stereotypes influence peoples’ attitudes and behaviors. Reliable and valid measures of stereotypes—both implicit and explicit—can help us create more accurate understandings of the political world.