Search Results

Microbial community ecology of tick-borne human pathogens

Clay Keith, Clay Fuqua, Curt Lively, and Michael J. Wade

in Disease Ecology: Community structure and pathogen dynamics

The prevalence of human pathogens may be determined in part by microbial interactions within vectors. Ticks represent the primary source of vector-borne infections disease in the United States and ... More

The prevalence of human pathogens may be determined in part by microbial interactions within vectors. Ticks represent the primary source of vector-borne infections disease in the United States and carry more human pathogens than any other arthropod. This chapter explores the use of molecular genetic methods to examine microbial community structure in several common tick species to test the direction and strength of microbial interactions. Microbial interactions are explored via epidemiological models to see whether they affect pathogen prevalence and disease incidence. The results are generally applicable to a wide range of arthropod vectors of disease such as mosquitoes, fleas, and lice, and provide a better understanding of how microbial community ecology affects disease dynamics.Less

Disease dynamics in plant communities

Charles E. Mitchell and Allson G. Power

in Disease Ecology: Community structure and pathogen dynamics

The prevalence of human pathogens may be determined in part by microbial interactions within vectors. Ticks represent the primary source of vector-borne infections disease in the United States and ... More

The prevalence of human pathogens may be determined in part by microbial interactions within vectors. Ticks represent the primary source of vector-borne infections disease in the United States and carry more human pathogens than any other arthropod. This chapter explores the use of molecular genetic methods to examine microbial community structure in several common tick species to test the direction and strength of microbial interactions. Microbial interactions are explored via epidemiological models to see whether they affect pathogen prevalence and disease incidence. The results are generally applicable to a wide range of arthropod vectors of disease such as mosquitoes,fleas, and lice, and provide a better understanding of how microbial community ecology affects disease dynamics.Less

Host selection and its role in transmission of arboviral encephalitides

Robert S. Unnasch, Eddie W. Cupp, and Thomas R. Unnasch

in Disease Ecology: Community structure and pathogen dynamics

Several highly virulent, arthropod-borne viruses (arboviruses) that cause serious human neurological diseases, such as West Nile encephalomyelitis, are transmitted by mosquitoes that feed on both ... More

Several highly virulent, arthropod-borne viruses (arboviruses) that cause serious human neurological diseases, such as West Nile encephalomyelitis, are transmitted by mosquitoes that feed on both wildlife and human hosts. The recent emergence of these viruses has prompted investigation into those mosquito species and wild birds that are conspicuously involved in transmission cycles. This chapter describes an innovative molecular technique used to identify the source of mosquito blood meals, which is proving to be quite useful in discerning the roles of particular vector and host species. This technique is used to determine the vectorial capacity of different mosquito species. Because species interactions are of prime importance in determining vectorial capacity, an understanding of community ecology is clearly essential for elucidating the epidemiology of vectored diseases.Less

Freshwater community interactions and malaria

Eliška Rejmánková, John Grieco, Nicole Achee, Penny Masuoka, Kevin Pope, Donald Roberts, and Richard M. Higashi

in Disease Ecology: Community structure and pathogen dynamics

The incidence of malaria has recently increased in many parts of the tropics. This increase is due mainly to drug resistance and the failure of disease control measures. But changes in vector ... More

The incidence of malaria has recently increased in many parts of the tropics. This increase is due mainly to drug resistance and the failure of disease control measures. But changes in vector (mosquito) and host (human) ecology may also play a role. This chapter presents results from field studies in Belize showing that freshwater community changes lead to changes in malaria transmission. Changes in vegetation structure, mediated by an anthropogenic increase in aquatic nutrients, lead to replacement of one mosquito species by another. Species-specific habitat selection by mosquito females leads to the replacement of a less efficient malaria vector by a more efficient one. Vector ecology is influenced by changes in land cover and host availability, leading to predictable changes in malarial dynamics.Less

Specificity of the innate immune system: a closer look at the mosquito pattern-recognition receptor repertoire

Suchismita Das, Yuemei Dong, Lindsey Garver, and George Dimopoulos

in Insect Infection and Immunity: Evolution, Ecology, and Mechanisms

The insect innate immune system is encoded by three major functional categories of genes that are involved in (1) recognition of invading microbes; (2) immune-signal amplification and transduction; ... More

The insect innate immune system is encoded by three major functional categories of genes that are involved in (1) recognition of invading microbes; (2) immune-signal amplification and transduction; and (3) effector mechanisms that mediate the killing and clearance of infectious micro-organisms. Despite its lack of adaptive immune mechanisms and antibody-mediated defences similar to those found in vertebrates, the innate immune system in insects is quite specific in its antimicrobial action. Once invading microbes are recognized through specific interaction between pattern-recognition receptors (PRRs) and pathogen-associated molecular patterns (PAMPs), a variety of defence reactions can be activated. This chapter discusses the specificity of the innate immune responses at the level of PRRs, with a major focus on the mosquito Anopheles gambiae as a model system. It first provides a general overview of the insects' PRR repertoire and highlights some of its most interesting features with regard to antimicrobial defence. It then provides detailed molecular and functional descriptions of some of the best characterized PRR families.Less

Comparative genomics of insect immunity

Fotis Kafatos, Robert Waterhouse, Evgeny Zdobnov, and George Christophides

in Insect Infection and Immunity: Evolution, Ecology, and Mechanisms

This chapter compares the Drosophila group with mosquitoes and honeybees to disentangle common themes from specific components of immunity. Honeybees, for example, have a relatively small set of ... More

This chapter compares the Drosophila group with mosquitoes and honeybees to disentangle common themes from specific components of immunity. Honeybees, for example, have a relatively small set of immune genes which demonstrate a high degree of conservatism. They are most intriguing when compared with non-social insects, as the differences between them are attributable to the evolution of sociality in bees and other Hymenoptera. The chapter highlights how the use of comparative genomics led to the unravelling of evolutionary novelties. Genes containing leucine-rich repeats are an example, which led to the discovery of a new complement-like mechanism in mosquitoes.Less

“Futile Souls Adrift on a Yacht”

Lillian Hellman

in The Dixie Limited: Writers on William Faulkner and His Influence

This chapter is an essay which reviews William Faulkner's novel, Mosquitoes, which takes place on a yacht. Mrs. Maurier, a collector of famous people in her own home town of New Orleans, arranges a ... More

This chapter is an essay which reviews William Faulkner's novel, Mosquitoes, which takes place on a yacht. Mrs. Maurier, a collector of famous people in her own home town of New Orleans, arranges a boating party for the more artistic of her friends. Among her guests are a sculptor, a young niece and the niece's mechanically inclined brother, a Jew and his sister, and a poet. The text praises the humor of Faulkner's writing, claiming that it approaches a brilliance that you can rightfully expect only in the writings of a few men. It also suggests that certain portions of Mosquitoes are “overwritten, certain Joycean passages that have no direct place or bearing, parts that are heavy and dull with overloaded description”.Less

“Preface” to British edition of Soldiers’ Pay

Richard Hughes

in The Dixie Limited: Writers on William Faulkner and His Influence

This chapter is an essay examining Soldiers' Pay, the story of a soldier who returns, like an unwanted ghost, to the country he has “saved.” The scene is the state of Georgia, an unfamiliar one to ... More

This chapter is an essay examining Soldiers' Pay, the story of a soldier who returns, like an unwanted ghost, to the country he has “saved.” The scene is the state of Georgia, an unfamiliar one to most English readers, but not so unfamiliar as that they will expect. William Faulkner deals with an aspect of the war previously practically untouched: peace. The text argues that Soldiers' Pay is more than just another (in the popular sense) “War Book.” It is a tragic, fascinating, and beautiful narrative; told by a man who writes because he can. It is not only an achievement, it is promising as well: and the promise is borne out by at least two other Faulkner novels, Mosquitoes and The Sound and the Fury.Less

West Nile Virus: Deaths of Crows and Humans

Michael B. A. Oldstone

in Viruses, Plagues, and History: Past, Present, and Future

This chapter addresses West Nile virus, the cause of a formerly unknown disease whose path through America was a trail of dead birds and dead people. West Nile virus is currently the most common and ... More

This chapter addresses West Nile virus, the cause of a formerly unknown disease whose path through America was a trail of dead birds and dead people. West Nile virus is currently the most common and severe form of mosquito-borne encephalitis in North America. At present, West Nile virus has been isolated from over 300 species of birds. The infected birds fall into two major groups: those that carry the virus and are asymptomatic and those that develop an often fatal neurologic disease. Crows, jays, magpies, and house finches, upon infection, develop high virus loads and rapidly infect the mosquitoes that prey on them. House sparrows are also reservoirs for high titers of West Nile virus and play a role in the virus’ transmission in city areas. Humans are incidental/accidental hosts in the natural mosquito–bird cycle of this viral infection. Most humans who become infected have received bites from mosquitoes carrying the West Nile virus. The viruses then replicate at the bite site and likely spread to specialized cells, dendritic cells, which act as processors of foreign antigens. Viruses may also travel directly from the bite site into and through the blood.Less

Introduction Combating Malaria in East Asia:: A Historical Perspective

Ka-che Yip

in Disease, Colonialism, and the State: Malaria in Modern East Asian History

This chapter provides an historical study of malaria in modern East Asia. It examines how different countries attempted to combat this mosquito-borne disease in the context of the global history of ... More

This chapter provides an historical study of malaria in modern East Asia. It examines how different countries attempted to combat this mosquito-borne disease in the context of the global history of malaria since the nineteenth century. It notes that malaria has affected human developments since ancient times, and it remains a major health problem in Asia, not to mention Africa, today. It reports that the study of malaria has largely been dominated by scientists as well as medical and public health specialists, while social scientists and historians have only recently been contributing their expertise to examining the cultural, social, economic, and political dimensions of the relationship between human beings and diseases, including malaria. It therefore fills an important gap in understanding the global problem of malaria and its impact on human society in an area where malaria has been, and still remains, a serious public health concern.Less

Anti-malaria Policy and Its Consequences in Colonial Taiwan

Ku Ya Wen

in Disease, Colonialism, and the State: Malaria in Modern East Asian History

This chapter aims to discuss the dynamics of change in anti-malaria policies in colonial Taiwan and their consequences. It initially examines how the Taiwanese and Japanese formed their respective ... More

This chapter aims to discuss the dynamics of change in anti-malaria policies in colonial Taiwan and their consequences. It initially examines how the Taiwanese and Japanese formed their respective understanding of the etiology and perception of malaria, and how the Japanese created a discourse of “othering” to define malaria. It discusses the initial process of anti-malaria policymaking in the 1910s and the real concerns behind malaria as a health issue. It identifies the facts — neglected in studies of colonial Taiwan medicine — associated with the change of anti-malaria policy direction beginning in 1919, and suggests that the promulgation of assimilative reform is the key to understanding this change. It notes that instead of merely targeting the parasite in the human body or the mosquitoes, the effort to eradicate the colonial disease came to involve the attempted transformation of the Taiwanese people and environment. It also studies the Japanese colonizers' self-assessment of the anti-malaria policies.Less

Prophets and Zealots: Paul Schrader’s Adaptations of The Mosquito Coast and The Last Temptation of Christ

Erica Moulton

in ReFocus: The Films of Paul Schrader

Focuses on Paul Schrader's process of adapting two novels—Paul Theroux's The Mosquito Coast and Nikos Kazantzakis' The Last Temptation of Christ. Draws on the Harry Ransom Center's collection of Paul ... More

Focuses on Paul Schrader's process of adapting two novels—Paul Theroux's The Mosquito Coast and Nikos Kazantzakis' The Last Temptation of Christ. Draws on the Harry Ransom Center's collection of Paul Schrader's papers, Schrader's annotated copies of The Last Temptation of Christ and The Mosquito Coast, the outlines that he created for both films, and the multiple script drafts. Argues there is an inherent dilemma with The Mosquito Coast because the voiceover structure distances the viewer from the protagonist, Allie Fox, instead telling the story through the eyes of his son, Charlie. However, in Last Temptation (1978), Jesus undergoes trials that challenge his followers while remaining the audience's touchstone. The shifting use of voiceover as a technical tool in screenwriting therefore serves as a gauge for demonstrating how Schrader envelops viewers in his characters' worldviews. The last section of the chapter reflects on how Schrader's presentation of such themes is informed by his own critical concept of transcendental film style.Less

Viral incidence estimation —a shortcut

Steve Selvin

in The Joy of Statistics: A Treasury of Elementary Statistical Tools and their Applications

Often the incidence of a specific virus is estimated from collected data and a process of pooling these data provides an efficient and easily applied shortcut.

West Nile Virus Ecology in Sagebrush Habitat and Impacts on Greater Sage-Grouse Populations

Brett L. Walker and David E. Naugle

in Greater Sage-Grouse: Ecology and Conservation of a Landscape Species and Its Habitats

This chapter examines the ecology of West Nile virus in sagebrush (Artemisia spp.) ecosystems of western North America, as well as its influence on Greater Sage-Grouse (Centrocercus urophasianus) ... More

This chapter examines the ecology of West Nile virus in sagebrush (Artemisia spp.) ecosystems of western North America, as well as its influence on Greater Sage-Grouse (Centrocercus urophasianus) mortality and survival. Using demographic models, it also discusses potential impacts on population growth and recommends strategies for managing and monitoring such impacts. West Nile virus can simultaneously reduce juvenile, yearling, and adult survival — three vital rates important for population growth in this species — and persistent low-level West Nile virus mortality and severe outbreaks may lead to local and regional population declines. West Nile virus mortality in simulations was projected to reduce population growth. However, marked spatial and annual fluctuations in nest success, chick survival, and other sources of adult mortality are likely to mask population-level impacts in most years. Eliminating mosquito breeding habitat from anthropogenic water sources is crucial for reducing impacts. Better data are needed on geographic and temporal variation in infection rates, mortality, and seroprevalence range-wide.Less

Civilian Government and Politics (the 1930s)

Mark Clague

in The Memoirs of Alton Augustus Adams, Sr.: First Black Bandmaster of the United States Navy

Three tragedies assailed Adams in the early 1930s. Economic stagnation gripped the islands in the wake of the navy's departure, proving one positive contribution of the naval administration. While an ... More

Three tragedies assailed Adams in the early 1930s. Economic stagnation gripped the islands in the wake of the navy's departure, proving one positive contribution of the naval administration. While an ardent navy supporter, Adams worked effectively with the islands' new civilian governor, Paul M. Pearson, and came to admire Pearson's leadership and economic initiatives. This chapter talks extensively about two Pearson projects: Bluebeard Castle Hotel and the draining of “Mosquito Bay.” Conflicts with the appointed assistant to the governor resulted in a series of investigations that resulted in considerable political damage to Pearson. When the islands' legislature proclaimed the Virgin Islands a refuge for those, especially Jews, fleeing deteriorating conditions in Europe as World War II approached, Ickes championed the humanitarian idea in Washington. Here the tradition of tolerance and openness that Adams claimed for the Virgin Islands seemed at work, leading the United States as a whole in a more compassionate and humanitarian direction.Less

Zika Comes to the Western Hemisphere and Americas: How, When, Consequences

Michael B. A. Oldstone

in Viruses, Plagues, and History: Past, Present, and Future

This chapter traces the history of the Zika virus. Viruses are usually messengers of bad news. The bad news emerging as a specialty of infection by Zika viruses and the harm they cause is the ... More

This chapter traces the history of the Zika virus. Viruses are usually messengers of bad news. The bad news emerging as a specialty of infection by Zika viruses and the harm they cause is the long-term disability of the most vulnerable populations: pregnant women and their babies. Zika virus is a member of the flavivirus group, whose fellow members are yellow fever and West Nile viruses; all three are transmitted by mosquitoes. Attacks by Zika virus and the disease it caused unexpectedly exploded in 2015–2016, mainly in Brazil and surrounding countries in Central and South America and the Caribbean. Zika was then transported to the United States. Zika infections recorded in the United States were linked primarily to airplane or ship travelers from the areas of Zika outbreaks. Adult males and females infected with Zika virus may develop an autoimmune disease termed Guillain-Barré syndrome (GBS). GBS describes persons whose own immune system attacks their nerves (polyneuropathy), leading to symmetrical weakness of the extremities requiring hospitalization.Less