301 research outputs found
Shock wave-boundary layer interactions in laminar transonic flow.
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76478/1/AIAA-1973-239-112.pd
Struggling to a monumental triumph : Re-assessing the final stages of the smallpox eradication program in India, 1960-1980
The global smallpox program is generally presented as the brainchild of a handful of actors from the WHO headquarters in Geneva and at the agency's regional offices. This article attempts to present a more complex description of the drive to eradicate smallpox. Based on the example of India, a major focus of the campaign, it is argued that historians and public health officials should recognize the varying roles played by a much wider range of participants. Highlighting the significance of both Indian and international field officials, the author shows how bureaucrats and politicians at different levels of administration and society managed to strengthen—yet sometimes weaken—important program components. Centrally dictated strategies developed at WHO offices in Geneva and New Delhi, often in association with Indian federal authorities, were reinterpreted by many actors and sometimes changed beyond recognition
Sox6 Directly Silences Epsilon Globin Expression in Definitive Erythropoiesis
Sox6 is a member of the Sox transcription factor family that is defined by the conserved high mobility group (HMG) DNA binding domain, first described in the testis determining gene, Sry. Previous studies have suggested that Sox6 plays a role in the development of the central nervous system, cartilage, and muscle. In the Sox6-deficient mouse, p(100H), ɛy globin is persistently expressed, and increased numbers of nucleated red cells are present in the fetal circulation. Transfection assays in GM979 (erythroleukemic) cells define a 36–base pair region of the ɛy proximal promoter that is critical for Sox6 mediated repression. Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) assays demonstrate that Sox6 acts as a repressor by directly binding to the ɛy promoter. The normal expression of Sox6 in wild-type fetal liver and the ectopic expression of ɛy in p(100H) homozygous fetal liver demonstrate that Sox6 functions in definitive erythropoiesis. The present study shows that Sox6 is required for silencing of ɛy globin in definitive erythropoiesis and suggests a role for Sox6 in erythroid cell maturation. Thus, Sox6 regulation of ɛy globin might provide a novel therapeutical target in the treatment of hemoglobinopathies such as sickle cell anemia and thalassemia
Multifaceted contributions : health workers and smallpox eradication in India
Smallpox eradication in South Asia was a result of the efforts of many grades of health-workers. Working from within the confines of international organisations and government structures, the role of the field officials, who were of various nationalities and also drawn from the cities and rural enclaves of the countries in these regions, was crucial to the development and deployment of policies. However, the role of these personnel is often downplayed in official histories and academic histories, which highlight instead the roles played by a handful of senior officials within the World Health Organization and the federal governments in the sub-continent. This article attempts to provide a more rounded assessment of the complex situation in the field. In this regard, an effort is made to underline the great usefulness of the operational flexibility displayed by field officers, wherein lessons learnt in the field were made an integral part of deploying local campaigns; careful engagement with the communities being targeted, as well as the employment of short term workers from amongst them, was an important feature of this work
The Role of Public Health Institutions in Global Health System Strengthening Efforts: The US CDC's Perspective
Peter Bloland and colleagues from the US CDC lay out the agency's priorities for health systems strengthening efforts
A sensual philology for Anglo-Saxon England
What forgotten forms can philology assume anew? Reassessing how early medieval writers loved words differently than we do reveals significant gaps between past and presence senses of the physical phenomena words can index. In the early medieval language of Old English texts there remains a largely uncharted capacity for less linguistically driven aspects of expression, formed through a network of words, sounds, bodies and media: how the mute sound of a bell and the crook of a silent finger come together in medieval sign language, or how the Old English word for ring becomes a weeping, poetic gasp within a heaving breast. Such early medieval moments of communication survive because of language and in spite of language, and qualify the visualist framework through which we predictably reconstitute the medieval past, calling, /sotto voce/, for more than lovely words
Social Contact Networks and Disease Eradicability under Voluntary Vaccination
Certain theories suggest that it should be difficult or impossible to eradicate a vaccine-preventable disease under voluntary vaccination: Herd immunity implies that the individual incentive to vaccinate disappears at high coverage levels. Historically, there have been examples of declining coverage for vaccines, such as MMR vaccine and whole-cell pertussis vaccine, that are consistent with this theory. On the other hand, smallpox was globally eradicated by 1980 despite voluntary vaccination policies in many jurisdictions. Previous modeling studies of the interplay between disease dynamics and individual vaccinating behavior have assumed that infection is transmitted in a homogeneously mixing population. By comparison, here we simulate transmission of a vaccine-preventable SEIR infection through a random, static contact network. Individuals choose whether to vaccinate based on infection risks from neighbors, and based on vaccine risks. When neighborhood size is small, rational vaccinating behavior results in rapid containment of the infection through voluntary ring vaccination. As neighborhood size increases (while the average force of infection is held constant), a threshold is reached beyond which the infection can break through partially vaccinated rings, percolating through the whole population and resulting in considerable epidemic final sizes and a large number vaccinated. The former outcome represents convergence between individually and socially optimal outcomes, whereas the latter represents their divergence, as observed in most models of individual vaccinating behavior that assume homogeneous mixing. Similar effects are observed in an extended model using smallpox-specific natural history and transmissibility assumptions. This work illustrates the significant qualitative differences between behavior–infection dynamics in discrete contact-structured populations versus continuous unstructured populations. This work also shows how disease eradicability in populations where voluntary vaccination is the primary control mechanism may depend partly on whether the disease is transmissible only to a few close social contacts or to a larger subset of the population
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