Class,culture, and the Miskito Indians: A historical perspective

Conclusion In this paper I have endeavored to outline a dialectical analysis of the Miskito Indian historical experience of the last 350 years. This history has been divided into three periods, in each of which class processes have been integrally tied to particular ethnic configurations. In the first, pre-contact period, a series of autonomous egalitarian hunting, gathering and horticultural groups, linked in a network of mutual trading and raiding, inhabited the various river basins of the coastal region. In the second period, beginning roughly in the early 17th century, integration as a periphery in the British mercantile empire engendered a political economic transformation in which local headmen emerged as focal points in the articulation of coastal production with British exchange networks. The new level of power over the allocation of social surpluses assumed by these headmen was validated through the symbolic framework of British monarchy. This also served the geopolitical interests of the British. The rise of this incipient tributary mode of production was a central force in the emergence of the Miskito as a new ethnic entity.The decline of mercantilism and the rise of the second phase of the Industrial Revolution saw a shift in British interests in the periphery from commodities to sources of labor and loci for investment. This brought about a second transformation in which the incipient tributary kingship was undermined both from within, by the demise of the slave trade, and from without, by increasing foreign contact coupled with population expansion and the large-scale introduction of wage labor. The Miskito were now integrated fairly uniformly as an underclass in the new coastal class hierarchy. However, wage labor took its place beside kin-ordered production and exchange in a dualistic system, which alternated with continual booms and busts in the local economy. Ethnic groupings now both defined, and were rooted in, class differentiation.As we have seen, due to its theoretically fragmented and inconsistent nature, our received anthropological history of the Miskito also serves us poorly, if we want to develop a critical understanding of the Atlantic coast of Nicaragua and its dilemmas within the revolution. Focusing on the intersection of class and ethnic processes through history gives us a more coherent and analytically convincing picture. It provides us, as well, with a basis for a deeper understanding of the roots of the Miskito/Sandinista conflict. While politics conceived in terms of class or in terms of ethnicity have given rise to ostensibly different social agendas, it is clear that historically the two have never been separate aspects of existence. Miskito culture is an historical creation — evolved in response to the ongoing pressures of integration into a world political economy whose center lay in Europe or the United States and expressive of the class processes set off by these encounters.Yet it is more than just an expression of these processes, for the way in which the Miskito defined and articulated themselves as a cultural unit played a central role in the shaping of those processes themselves. Thus, a Marxist analysis that downplays the importance of ethnic identity in favor of class identity will miss fundamental aspects of what it is to be Miskito, culturally and politically, as well as economically. By the same token, ethnic movements that eschew class analysis in favor of a strictly cultural interpretation will fall into a similar trap, becoming perhaps more vulnerable to acting in ways that go against their own interests. Whatever the outcome of this particular situation, given the size and importance of the indigenous peoples through the Americas, the left's ability to deal with culture as a basis of resistance will have a deep impact on the course of progressive social change throughout the region.Daniel Noveck received his BA degree in anthropology, from the University of Massachusetts, Amherst.     

Class,political power,and nationalism in Syria: a historical sociology of state-society relations

In the wake of the present crisis in the Middle East, this paper proposes to locate the processes of state formation and nation building within a larger historical context, recovering the historicity of the crisis. It records the rise and fall of a nationalist developmental project in Syria through an analysis of class relations. It highlights an essential continuity in the nature of class reproduction from the late Ottoman to the early independence period, centered on the conservative nationalism of the mercantile ruling bloc. It associates the rise of a national developmental project with the politicization of the “middle classes,” which occupied a central role in the state apparatus. This class represented the main driving force behind the expansion of the boundaries of political power and the process of nation building. It is the class polarization of society that fuelled the development of a nation-building project and favored the creation of a national populist alliance against the monopoly of traditional ruling classes. However, this alliance was short-lived, and the process of authoritarian demobilization that followed led to the resurgence of personal networks and the end of nation building.     

Basal medium development for serum-free culture: a historical perspective

The evolution of basal synthetic formulations to support mammalian cell culture applications has been facilitated by the contributions of many investigators. Definition of minimally-required nutrient categories by Harry Eagle in the 1950's spawned an iterative process of continuous modification and refinement of the exogenous environment to cultivate new cell types and to support emerging applications of cultured mammalian cells. Key historical elements are traced, leading to the development of high potency, basal nutrient formulations capable of sustaining serum-free proliferation and biological production. Emerging techniques for alimentation of fed batch and continuous perfusion bioreactors, using partial nutrient concentrates deduced from spent medium analysis, can enhance medium utilization and bioreactor productivity.     

Cell culture process development: advances in process engineering

Representatives from the cell culture process development community met on September 11 and 12, 2006 at the ACS National Meeting in San Francisco to discuss "Cell Culture Process Development: Advances in Process Engineering". This oral session was held as part of the Division of Biochemical Technology (BIOT) program. The presentations addressed the very small scale (less than 1 mL) to the very large scale (20,000 L). The topics covered included development of high throughput cell culture screening systems, modeling and characterization of bioreactor environments from mixing and shear perspectives at both small and large scales, systematic approaches for improving scale-up and scale-down activities, development of disposable bioreactor technologies, and novel perfusion culture approaches. All told, this well-attended session resulted in a valuable exchange of technical information and demonstrated a high level of interest within the process development community.     

Scale-up of a myoblast culture process

The effects of different types of cell carriers, strategies for cell transfer on carriers, and of several fusion inhibitors on the growth kinetics of primary human myoblasts culture were studied in order to develop a bioprocess suitable for the treatment of Duchenne muscular dystrophy based on the transplantation of unfused cells. Our results indicate that myoblast production is larger on Cytodex 1 and 3 than on polypropylene or polyester fabrics and on a commercial porous macrocarrier. Myoblast growth conditions with Cytodex 1 were further investigated to establish the bioprocess operating conditions. It was found that microcarrier density of 3 g DW l(-1), inoculum density of 2x10(5) cells ml(-1), and continuous agitation speed of 30-rpm result in final myoblast production comparable to static cultures. However, for all the culture conditions used, myoblasts growth kinetics exhibited a lag phase that lasted a minimum of 1 week prior to growth, the end of the lag phase correlating with the appearance of microcarrier aggregates. Based on this observation, we propose that aggregation promotes cell growth by offering a network of very large inter-particular pores that protect cells from mechanical stress. We took advantage of the presence of these aggregates for the scale-up of the culture process. Indeed, using myoblast-loaded microcarrier-aggregates instead of myoblast suspension to inoculate a fresh suspension of microcarriers significantly reduced the duration of the lag phase and allowed the scale-up of the bioprocess at the 500-ml scale. In order to ensure the production of unfused myoblasts, the efficiency of five different fusion inhibitors was investigated. Only calpeptin (9.1 microg ml(-1)) significantly inhibited the fusion of the myoblasts, while TGFbeta (50 ng ml(-1)) and LPA (10 microg ml(-1)) increased myoblasts growth but did not affect fusion, sphingosine (30 microg ml(-1)) induced a 50% death and NMMA (25 microg ml(-1)) had no effect on either growth or fusion. Finally, transplantation trials on severe combined immunodeficient mice showed that microcarrier-cultured human myoblasts grown using the optimized bioprocess resulted in grafts as successful as myoblasts grown in static cultures. The bioprocess, therefore, prove to be suitable for the large-scale production of myoblasts required for muscular dystrophy treatment.     

The culture of single plant cells: a historical view.

Plant tissue culture, introduced unsuccessfully at the beginning of the twentieth century by Haberlandt, received full confirmation in the late Thirties by the works of Gautheret and Nobécourt, thanks to the discovery of auxin. A further special improvement--the free cell culture--, already fore-told by Haberlandt, was successfully achieved towards the mid-1950s by several physiologists thanks to coconut milk (cytokinin). The English physiologist Frederick Steward (who grouped an excellent American team of research during his twenty years stay at the Cornell University in Ithaca) was able to obtain complete cell differentiation from single cells cultured in vitro and demonstrate the totipotence of plant cells at any stage of development. The historical meaning of the research of Steward's team, accomplished between 1958 and 1970, rests on the concept of plant hormones as regulators of gene activity. In other terms, organogenesis was conceived as an epigenetically controlled series of events in which plant genes were "switched on" or "switched off" by special biomolecules. Steward's research paved the way for molecular plant physiology and inspired future research on the relation between cell receptors and specific hormones.     

Effect of culture conditions of Kluyveromyces marxianus on its autolysis, and process optimization

Cultivation of the lactose-metabolizing yeast Kluyveromyces marxianus var. marxianus (formerly K.?fragilis) on supplemented whey permeate resulted in cellular yield little affected by culture conditions in the ranges pH?=?2.3–5 and T?=?30–40?°C. When autolysis was induced only by energy source deficiency and thermal shock, cellular material solubilization depended slightly on autolysis temperature in the range T?=?45–60?°C. On the contrary, the process was under tight control of culture conditions; when autolysis was carried out at 50?°C with an initial dry cellular concentration of 50?g l^?1, a clear optimum was observed for cells cultivated at pH?=?4.5 and T?=?35?°C. So the critical step of the autolytic process consisted in biosynthesis of lytic enzymes (during cell growth) rather than enzymatic progress (during autolysis). These results were compatible with a model previously proposed for Saccharomyces cerevisiae [1].     

An online, non-invasive fluorescence probe for immobilized cell culture process development

An online, analytical technology was developed that utilized fluorescence to detect cells during an immobilized cell culture process. Chinese hamster ovary (CHO) cells that produced monoclonal antibodies (mAb) were transfected to express green fluorescent protein (GFP), and stable, fluorescence-positive cells were obtained by fluorescence-activated cell sorting (FACS). The immobilized cell culture process was then used to test the effects of sodium butyrate on cells. In this study, cells were cultured in porous, fibrous matrices that were placed in spinner flasks. A lab-scale, perfusion bioreactor with computer-controlled, online fluorescence sensors that continuously detected GFP fluorescence and quantified cell growth was utilized. In addition, the level of GFP fluorescence was used to predict mAb production in the culture without sampling for cell counting and protein analysis. Thus, non-invasive, fluorescence detection of cells provided a rapid, reliable and robust approach for developing an immobilized cell culture process.     

Assessing historical fish community composition using surveys, historical collection data, and species distribution models

Accurate establishment of baseline conditions is critical to successful management and habitat restoration. We demonstrate the ability to robustly estimate historical fish community composition and assess the current status of the urbanized Barton Creek watershed in central Texas, U.S.A. Fish species were surveyed in 2008 and the resulting data compared to three sources of fish occurrence information: (i) historical records from a museum specimen database and literature searches; (ii) a nearly identical survey conducted 15 years earlier; and (iii) a modeled historical community constructed with species distribution models (SDMs). This holistic approach, and especially the application of SDMs, allowed us to discover that the fish community in Barton Creek was more diverse than the historical data and survey methods alone indicated. Sixteen native species with high modeled probability of occurrence within the watershed were not found in the 2008 survey, seven of these were not found in either survey or in any of the historical collection records. Our approach allowed us to more rigorously establish the true baseline for the pre-development fish fauna and then to more accurately assess trends and develop hypotheses regarding factors driving current fish community composition to better inform management decisions and future restoration efforts. Smaller, urbanized freshwater systems, like Barton Creek, typically have a relatively poor historical biodiversity inventory coupled with long histories of alteration, and thus there is a propensity for land managers and researchers to apply inaccurate baseline standards. Our methods provide a way around that limitation by using SDMs derived from larger and richer biodiversity databases of a broader geographic scope. Broadly applied, we propose that this technique has potential to overcome limitations of popular bioassessment metrics (e.g., IBI) to become a versatile and robust management tool for determining status of freshwater biotic communities.     

Production,characterization and use of expendable kefir starter culture in the kefir production process

Upon sterilization, freeze-dried kefir grains are to be supplemented with yeast preparation, yeast showing the lowest survival in the course of freeze drying. A mixture of 20% sucrose solution and starch appeared to be the most efficient dispersing agent to protect yeast in the freeze-drying process. A starter which is produced with the kefir starter culture, does not differ in its microbiological, biochemical and organoleptic properties from a starter as obtained with kefir grains in the same time, such starter shows a better consistency. The preparation of such starters is less laborious and less complicated than the preparation of starters using kefir grains.     

A high-yielding, generic fed-batch cell culture process for production of recombinant antibodies

A fed-batch cell culture process was developed that has general applicability to all evaluated Sp2/0 (n = 8) and NS0 (n = 1) antibody-producing cell lines. The two key elements of this generic process were a protein-free concentrated feed medium, and a robust, metabolically responsive feeding strategy based on the off-line measurement of glucose. The fed-batch process was shown to perform equivalently at the 15 L development scale and 750 L manufacturing scale. Compared to batch cultures, the fed-batch process yielded a 4. 3 fold increase in the average integral of viable cell concentration and a 1.7 fold increase in average specific antibody production rate, equivalent to a 7.6 fold increase in average final antibody concentration. The highest producing cell line reached a peak viable cell concentration of 1.0 x 10(7) cell mL(-1) and a final antibody concentration of 750 mg L(-1) in a 10 day process. For all lines evaluated, reducing bioreactor pH set point from 7.2 to 7.0 resulted in an additional 2.4 fold increase in average final antibody concentration. The optimized fed-batch process consistently yielded a volumetric productivity exceeding 50 mg L(-1) day(-1). This generic, high-yielding fed-batch process significantly decreased development time, and increased manufacturing efficiency, thereby facilitating the clinical evaluation of numerous recombinant antibodies.     

High‐throughput miniaturized bioreactors for cell culture process development: Reproducibility,scalability, and control

Decreasing the timeframe for cell culture process development has been a key goal toward accelerating biopharmaceutical development. Advanced Microscale Bioreactors (ambr?) is an automated micro‐bioreactor system with miniature single‐use bioreactors with a 10–15 mL working volume controlled by an automated workstation. This system was compared to conventional bioreactor systems in terms of its performance for the production of a monoclonal antibody in a recombinant Chinese Hamster Ovary cell line. The miniaturized bioreactor system was found to produce cell culture profiles that matched across scales to 3 L, 15 L, and 200 L stirred tank bioreactors. The processes used in this article involve complex feed formulations, perturbations, and strict process control within the design space, which are in‐line with processes used for commercial scale manufacturing of biopharmaceuticals. Changes to important process parameters in ambr? resulted in predictable cell growth, viability and titer changes, which were in good agreement to data from the conventional larger scale bioreactors. ambr? was found to successfully reproduce variations in temperature, dissolved oxygen (DO), and pH conditions similar to the larger bioreactor systems. Additionally, the miniature bioreactors were found to react well to perturbations in pH and DO through adjustments to the Proportional and Integral control loop. The data presented here demonstrates the utility of the ambr? system as a high throughput system for cell culture process development. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:718–727, 2014     

哺乳动物细胞灌流培养工艺开发与优化

近年来生物药市场需求量激增,高产量、高质量、低成本的哺乳动物细胞灌流培养工艺顺势成为工业界和学术界普遍关注的热点。文中围绕灌流培养工艺特有的操作环节及工艺优化应着重关注的细节展开论述,综述了近年来在灌流培养工艺开发和优化上取得的进步和提出的策略,以期为哺乳动物细胞灌流培养技术的开发提供参考。     

Stem cell culture engineering - process scale up and beyond

Advances in stem cell research and recent work on clinical trials employing stem cells have heightened the prospect of stem cell applications in regenerative medicine. The eventual clinical application of stem cells will require transforming cell production from laboratory practices to robust processes. Most stem cell applications will require extensive ex vivo handling of cells, from isolation, cultivation, and directed differentiation to product cell separation, cell derivation, and final formulation. Some applications require large quantities of cells in each defined batch for clinical use in multiple patients; others may be for autologous use and require only small-scale operations. All share a common requirement: the production must be robust and generate cell products of consistent quality. Unlike the established manufacturing process of recombinant protein biologics, stem cell applications will likely see greater variability in their cell source and more fluctuations in product quality. Nevertheless, in devising stem cell-based bioprocesses, much insight could be gained from the manufacturing of biological materials, including recombinant proteins and anti-viral vaccines. The key to process robustness is thus not only the control of traditional process chemical and physical variables, but also the sustenance of cells in the desired potency or differentiation state through controlling non-traditional variables, such as signaling pathway modulators.