Crossing, Creolization, and the African Roots of American Culture

Group Harmony: The Black Urban Roots of Rhythm and Blues. Stuart L. Goosman. Philadelphia: University of Pennsylvania Press, 2005. 291 pp.
Right to Rock: The Black Rock Coalition and the Cultural Politics of Race. Maureen Mahon. Durham, NC: Duke University Press, 2004. 317 pp.
Crossovers: Essays on Race, Music, and American Culture. John Szwed. Philadelphia: University of Pennsylvania Press, 2005. 283 pp.     

African Roots/American Cultures: Africa in the Creation of the Americas.

African Roots/American Cultures: Africa in the Creation of the Americas. Sheila S. Walker. ed. Lanham, MD: Rowman and Littlefield Publishers, Inc., 2001. 400 pp.     

Medicaid and the Mainstream: Reassessment in the Context of the Taxpayer Revolt

California''s Medicaid program—Medi-Cal—attempted to implement the ideal of mainstream medical care for the poor by giving program beneficiaries a “credit card” for use in the private health care marketplace. This exposed the program to the perverse economic incentives of the fee-for-service, costplus health care system, and contributed to a high rate of increase in program costs. Attempts to control costs have been equally perverse, resulting in low payment rates, the second-guessing of physician professional judgments, the probing of medical and fiscal records, and the use of computerized surveillance systems.Attempts to shift to the use of more efficient delivery systems have had small success. Attempts to attain cost containment through restructuring the Medi-Cal program have been rejected in the name of the mainstream ideal. Costs have continued to escalate, with annual increases as high as 20 percent in some years. Medi-Cal now costs $4 billion per year, the largest single program in California state government.The taxpayer revolt in California is creating a fiscal crisis that will force rethinking of the premises of publicly funded health care for the poor, and a restructuring of strategies for reaching that objective. In the short run, it appears that the issue may not be whether the indigent will have access to mainstream medical care, but whether they will have access to any medical care. In the longer run, the crisis should represent an opportunity for building a system of health care that can serve the financially disadvantaged at a cost tolerable to our society.     

The Innovative Materiality of Revitalization Movements: Lessons from the Pueblo Revolt of 1680

ABSTRACT  Although Wallace's revitalization movement model has been successfully utilized in scores of ethnographic and ethnohistorical studies of societies throughout the world, revitalization is considerably less well documented in archaeological contexts. An examination of the materiality of revitalization movements affords an opportunity to redress this lack by investigating how material culture creates and constrains revitalization phenomena. In this article, I reconsider the revitalization model through a case study focusing on the archaeology of the Pueblo Revolt of 1680, emphasizing the central role of materiality in the formation and mediation of these movements. In doing so, I examine the archaeological signatures of revitalization movements, concluding that they are highly negotiated and heterogeneous phenomena and that the materiality of these episodes cultivates cultural innovation. I also seek to demonstrate that the distinctive types of material culture produced through revitalization are not epiphenomenal but, rather, are crucially constitutive of revitalizing processes.     

Characterizing the admixed African ancestry of African Americans

Background

Accurate, high-throughput genotyping allows the fine characterization of genetic ancestry. Here we applied recently developed statistical and computational techniques to the question of African ancestry in African Americans by using data on more than 450,000 single-nucleotide polymorphisms (SNPs) genotyped in 94 Africans of diverse geographic origins included in the HGDP, as well as 136 African Americans and 38 European Americans participating in the Atherosclerotic Disease Vascular Function and Genetic Epidemiology (ADVANCE) study. To focus on African ancestry, we reduced the data to include only those genotypes in each African American determined statistically to be African in origin.

Results

From cluster analysis, we found that all the African Americans are admixed in their African components of ancestry, with the majority contributions being from West and West-Central Africa, and only modest variation in these African-ancestry proportions among individuals. Furthermore, by principal components analysis, we found little evidence of genetic structure within the African component of ancestry in African Americans.

Conclusions

These results are consistent with historic mating patterns among African Americans that are largely uncorrelated to African ancestral origins, and they cast doubt on the general utility of mtDNA or Y-chromosome markers alone to delineate the full African ancestry of African Americans. Our results also indicate that the genetic architecture of African Americans is distinct from that of Africans, and that the greatest source of potential genetic stratification bias in case-control studies of African Americans derives from the proportion of European ancestry.     

Roots1

ABSTRACT Many unicellular eukaryotic organisms possess complex fiber systems that organize and anchor the flagellar basal apparatus in the cell [20, 24]. In 1978 we first published the observation that one of these fiber systems, the striated flagellar root of the quadriflagellate green alga Tetraselmis subcordiformis (=Platymonas subcordiformis), is a contractile organelle [31]. We subsequently found that striated flagellar roots are composed, in part, of the Ca²⁺-binding protein centrin [30]. Since that time, centrin has been found to be a ubiquitous component of the flagellar basal apparatus, basal bodies and centrioles, and centrosomes and mitotic spindle poles of eukaryotic cells (for general reviews see [28, 34]). While we have learned a great deal about centrin from other organisms, our earliest success in understanding the biology of centrin was in large part due to the extraordinary extent to which Tetraselmis cells have elaborated their centrin-based organelles. In this paper, I will return attention to several unanswered questions concerning Tetraselmis striated flagellar root behavior and I will suggest several new directions that students may wish to pursue in order to tease fresh insights from this fascinating organism.     

Geotropic Behaviour of Roots

Response of roots to a gravitational stimulus consisting ofa sudden artificial change of orientation in the gravitationalfield can be resolved into a phase of very rapid curvature andreduced growth-rate which dies out rapidly and is followed bya phase of very slow response and normal growth-rate. A somewhat similar two-phased response to sudden reorientationis found in certain plagio- and diageotropic organs. The mechanismis discussed. Starch column chromatography has been used in an attempt toisolate growth factors which according to one postulate mightbe involved, and the significance of the findings is discussed. This technique is shown to be convenient for effecting volatileactive substances which are lost in paper chromatography.     

Salinity and the Hydraulic Conductance of Roots

The effect of salinity on hydraulic conductance of intact roots of tomato (Lycopersicon esculentum Mill.) and sunflower (Helianthus annuus L.) was determined in split-root experiments using salinized nutrient solutions. Experiments were conducted in controlled climate chambers under two or three relative humidity levels and four solution osmotic potential levels. The relationship between water flux through roots (J_v) and total water potential difference between the leaves and the root medium (Δψ) was linear, usually with a small intercept. Thus, the root hydraulic conductance (L) was not affected by salinity within the range of fluxes obtained in these experiments, with L= 0.036 mm h^?1 bar^?1 for tomato and L= 0.0167 mm h^?1 bar^?1 for sunflower. Our results agreed with theoretical analysis of coupled water and ion uptake. From Cl^? and Na⁺ uptake data, the reflection coefficient (o) for tomato roots was calculated as 0.956, which was compatible with the near-zero intercept. A large intercept for sunflower could not be readily explained. Relative humidity strongly affected root growth, with more rapid growth under low humidity conditions. Transpiration of sunflower plants was reduced by 20% when the relative humidity was increased from 34% to 84%, whereas transpiration in tomato was reduced 50%.     

Focus Issue on Roots: Perennial Roots to Immortality,

Maximum lifespan greatly varies among species, and it is not strictly determined; it can change with species evolution. Clonal growth is a major factor governing maximum lifespan. In the plant kingdom, the maximum lifespans described for clonal and nonclonal plants vary by an order of magnitude, with 43,600 and 5,062 years for Lomatia tasmanica and Pinus longaeva, respectively. Nonclonal perennial plants (those plants exclusively using sexual reproduction) also present a huge diversity in maximum lifespans (from a few to thousands of years) and even more interestingly, contrasting differences in aging patterns. Some plants show a clear physiological deterioration with aging, whereas others do not. Indeed, some plants can even improve their physiological performance as they age (a phenomenon called negative senescence). This diversity in aging patterns responds to species-specific life history traits and mechanisms evolved by each species to adapt to its habitat. Particularities of roots in perennial plants, such as meristem indeterminacy, modular growth, stress resistance, and patterns of senescence, are crucial in establishing perenniality and understanding adaptation of perennial plants to their habitats. Here, the key role of roots for perennial plant longevity will be discussed, taking into account current knowledge and highlighting additional aspects that still require investigation.There is enormous diversity among the types of perennial plants and among their patterns of aging (Jones et al., 2014). Perennial plants can be divided into herbaceous (or perennial herbs) and woody perennials (trees and shrubs), and therefore, they represent very diverse organisms in size and complexity from some herbs that weigh a few grams to huge trees like sequoias (Sequoia sempervirens). Among perennial herbs, the slowest growing species described thus far, Borderea pyrenaica (a small geophyte growing in the Central Pyrenees of northeastern Spain), is also the one with the longest maximum lifespan (350 years; Fig. 1). Interestingly, fecundity of this species increases with aging, representing a case of negative senescence (Garcia et al., 2011; Morales et al., 2013). If mortality falls as size increases and if size increases with age, then mortality will fall with age, and negative senescence occurs (Vaupel et al., 2004). Negative senescence is not common in the tree of life, but it seems to occur in not only some perennial herbs, such as B. pyrenaica (Garcia et al., 2011) and Plantago lanceolata (Roach and Gampe, 2004), but also, other phylogenetically distant organisms, such as turtles (Jones et al., 2014). Other perennial herbs with higher biomass production rates and consequently, larger sizes, such as stinging nettle (Urtica dioica), are much shorter-lived (a few years only). In this case, however, perenniality is achieved by allocating an important part of their energy to asexual reproduction (production of stolons; i.e. clonal propagation), giving rise to new entire clonal plants (Koskela, 2002). Indeed, this process happens in several other plant species with rapid growth that we commonly find in gardens, such as strawberries (Fragaria × ananassa) or raspberries (Rubus idaeus). Stolons can be produced aboveground or underground (in the latter case, forming rhizomes). Van Dijk (2009) elegantly reviewed the direct and indirect methods currently used to estimate plant age in clonal and nonclonal plants, showing several examples of plant species using clonal propagation with maximum lifespans of thousands of years, with the most notable example, King’s Lomatia (Lomatia tasmanica), being dated at 43,600 years (Lynch et al., 1998). Only one wild-living clone of this species is known. Clonal propagation is the only means for propagation, because it is a sterile ancient clone. When a branch falls, that branch produces new roots, establishing a new plant that is genetically identical to its parent (Lynch et al., 1998). Here, the production of new roots becomes essential for achieving potential immortality. Another example of extreme longevity is the bristlecone pine (Pinus longaeva), with a maximum lifespan of 5,062 years. It holds the record of longevity of a single individual within the plant kingdom, which was observed by Tom Harlan during 2012 in a living individual of this species in the White Mountains (the location has not been reported; Earle, 2013).Open in a separate windowFigure 1.Examples of extreme longevity in perennial plants. A, B. pyrenaica, the perennial herb with the longest lifespan described to date. B, A cross section of the tuber of B. pyrenaica showing the scars left by the five meristematic points in the spiral. C, P. longaeva, the species with the individual with the longest lifespan ever recorded (not using clonal propagation). D, C. nodosa meadow, with a detail of the rhizomes (E) that allow clonal propagation and potential immortality in this species. [See online article for color version of this figure.]The enormous diversity in lifespans within a species responds to specific life history traits and mechanisms evolved by each individual to adapt to its habitat. Particularities of roots in perennial plants, such as meristem indeterminacy, modular growth, stress resistance, and patterns of senescence, are crucial in understanding adaptation of perennial plants to their habitats, explaining differences in longevity. Here, the key role of roots in providing long lifespans in perennial plants will be discussed, taking into account current knowledge and highlighting additional aspects that still require investigation.     

Rural Revolt in Mexico: U.S. Intervention and the Domain of Subaltern Politics

Rural Revolt in Mexico: U.S. Intervention and the Domain of Subaltern Politics. Daniel Nugent. ed. Durham, NC: Duke University Press, 1998. 384 pp.