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In 2005, parts of the Amazon basin experienced the worst drought in one hundred years, and there were indications that 2006 could have been a second successive year of drought. A July 23, 2006 article in the UK newspaper The Independent reported Woods Hole Research Center results showing that the forest in its present ...
In 2010 the Amazon rainforest experienced another severe drought, in some ways more extreme than the 2005 drought. The affected region was approximate 1,160,000 square miles (3,000,000 km2) of rainforest, compared to 734,000 square miles (1,900,000 km2) in 2005. The 2010 drought had three epicenters where vegetation di...
Ctenophora (/tᵻˈnɒfərə/; singular ctenophore, /ˈtɛnəfɔːr/ or /ˈtiːnəfɔːr/; from the Greek κτείς kteis 'comb' and φέρω pherō 'carry'; commonly known as comb jellies) is a phylum of animals that live in marine waters worldwide. Their most distinctive feature is the ‘combs’ – groups of cilia which they use for swimming – ...
Almost all ctenophores are predators, taking prey ranging from microscopic larvae and rotifers to the adults of small crustaceans; the exceptions are juveniles of two species, which live as parasites on the salps on which adults of their species feed. In favorable circumstances, ctenophores can eat ten times their own ...
Most species are hermaphrodites—a single animal can produce both eggs and sperm, meaning it can fertilize its own egg, not needing a mate. Some are simultaneous hermaphrodites, which can produce both eggs and sperm at the same time. Others are sequential hermaphrodites, in which the eggs and sperm mature at different t...
Ctenophores may be abundant during the summer months in some coastal locations, but in other places they are uncommon and difficult to find. In bays where they occur in very high numbers, predation by ctenophores may control the populations of small zooplanktonic organisms such as copepods, which might otherwise wipe o...
Despite their soft, gelatinous bodies, fossils thought to represent ctenophores, apparently with no tentacles but many more comb-rows than modern forms, have been found in lagerstätten as far back as the early Cambrian, about 515 million years ago. The position of the ctenophores in the evolutionary family tree of anim...
Ctenophores form an animal phylum that is more complex than sponges, about as complex as cnidarians (jellyfish, sea anemones, etc.), and less complex than bilaterians (which include almost all other animals). Unlike sponges, both ctenophores and cnidarians have: cells bound by inter-cell connections and carpet-like bas...
Like sponges and cnidarians, ctenophores have two main layers of cells that sandwich a middle layer of jelly-like material, which is called the mesoglea in cnidarians and ctenophores; more complex animals have three main cell layers and no intermediate jelly-like layer. Hence ctenophores and cnidarians have traditional...
Ranging from about 1 millimeter (0.039 in) to 1.5 meters (4.9 ft) in size, ctenophores are the largest non-colonial animals that use cilia ("hairs") as their main method of locomotion. Most species have eight strips, called comb rows, that run the length of their bodies and bear comb-like bands of cilia, called "ctenes...
For a phylum with relatively few species, ctenophores have a wide range of body plans. Coastal species need to be tough enough to withstand waves and swirling sediment particles, while some oceanic species are so fragile that it is very difficult to capture them intact for study. In addition oceanic species do not pres...
The internal cavity forms: a mouth that can usually be closed by muscles; a pharynx ("throat"); a wider area in the center that acts as a stomach; and a system of internal canals. These branch through the mesoglea to the most active parts of the animal: the mouth and pharynx; the roots of the tentacles, if present; all...
The outer surface bears usually eight comb rows, called swimming-plates, which are used for swimming. The rows are oriented to run from near the mouth (the "oral pole") to the opposite end (the "aboral pole"), and are spaced more or less evenly around the body, although spacing patterns vary by species and in most spec...
It is uncertain how ctenophores control their buoyancy, but experiments have shown that some species rely on osmotic pressure to adapt to water of different densities. Their body fluids are normally as concentrated as seawater. If they enter less dense brackish water, the ciliary rosettes in the body cavity may pump th...
The largest single sensory feature is the aboral organ (at the opposite end from the mouth). Its main component is a statocyst, a balance sensor consisting of a statolith, a solid particle supported on four bundles of cilia, called "balancers", that sense its orientation. The statocyst is protected by a transparent dom...
Cydippid ctenophores have bodies that are more or less rounded, sometimes nearly spherical and other times more cylindrical or egg-shaped; the common coastal "sea gooseberry," Pleurobrachia, sometimes has an egg-shaped body with the mouth at the narrow end, although some individuals are more uniformly round. From oppos...
The tentacles of cydippid ctenophores are typically fringed with tentilla ("little tentacles"), although a few genera have simple tentacles without these sidebranches. The tentacles and tentilla are densely covered with microscopic colloblasts that capture prey by sticking to it. Colloblasts are specialized mushroom-sh...
There are eight rows of combs that run from near the mouth to the opposite end, and are spaced evenly round the body. The "combs" beat in a metachronal rhythm rather like that of a Mexican wave. From each balancer in the statocyst a ciliary groove runs out under the dome and then splits to connect with two adjacent com...
The Lobata have a pair of lobes, which are muscular, cuplike extensions of the body that project beyond the mouth. Their inconspicuous tentacles originate from the corners of the mouth, running in convoluted grooves and spreading out over the inner surface of the lobes (rather than trailing far behind, as in the Cydipp...
Lobates have eight comb-rows, originating at the aboral pole and usually not extending beyond the body to the lobes; in species with (four) auricles, the cilia edging the auricles are extensions of cilia in four of the comb rows. Most lobates are quite passive when moving through the water, using the cilia on their com...
The Beroida, also known as Nuda, have no feeding appendages, but their large pharynx, just inside the large mouth and filling most of the saclike body, bears "macrocilia" at the oral end. These fused bundles of several thousand large cilia are able to "bite" off pieces of prey that are too large to swallow whole – almo...
The Cestida ("belt animals") are ribbon-shaped planktonic animals, with the mouth and aboral organ aligned in the middle of opposite edges of the ribbon. There is a pair of comb-rows along each aboral edge, and tentilla emerging from a groove all along the oral edge, which stream back across most of the wing-like body ...
Most Platyctenida have oval bodies that are flattened in the oral-aboral direction, with a pair of tentilla-bearing tentacles on the aboral surface. They cling to and creep on surfaces by everting the pharynx and using it as a muscular "foot". All but one of the known platyctenid species lack comb-rows. Platyctenids ar...
Almost all species are hermaphrodites, in other words they function as both males and females at the same time – except that in two species of the genus Ocryopsis individuals remain of the same single sex all their lives. The gonads are located in the parts of the internal canal network under the comb rows, and eggs an...
Development of the fertilized eggs is direct, in other words there is no distinctive larval form, and juveniles of all groups generally resemble miniature cydippid adults. In the genus Beroe the juveniles, like the adults, lack tentacles and tentacle sheaths. In most species the juveniles gradually develop the body for...
When some species, including Bathyctena chuni, Euplokamis stationis and Eurhamphaea vexilligera, are disturbed, they produce secretions (ink) that luminesce at much the same wavelengths as their bodies. Juveniles will luminesce more brightly in relation to their body size than adults, whose luminescence is diffused ove...
Almost all ctenophores are predators – there are no vegetarians and only one genus that is partly parasitic. If food is plentiful, they can eat 10 times their own weight per day. While Beroe preys mainly on other ctenophores, other surface-water species prey on zooplankton (planktonic animals) ranging in size from the ...
Ctenophores used to be regarded as "dead ends" in marine food chains because it was thought their low ratio of organic matter to salt and water made them a poor diet for other animals. It is also often difficult to identify the remains of ctenophores in the guts of possible predators, although the combs sometimes remai...
On the other hand, in the late 1980s the Western Atlantic ctenophore Mnemiopsis leidyi was accidentally introduced into the Black Sea and Sea of Azov via the ballast tanks of ships, and has been blamed for causing sharp drops in fish catches by eating both fish larvae and small crustaceans that would otherwise feed the...
Because of their soft, gelatinous bodies, ctenophores are extremely rare as fossils, and fossils that have been interpreted as ctenophores have been found only in lagerstätten, places where the environment was exceptionally suited to preservation of soft tissue. Until the mid-1990s only two specimens good enough for an...
The early Cambrian sessile frond-like fossil Stromatoveris, from China's Chengjiang lagerstätte and dated to about 515 million years ago, is very similar to Vendobionta of the preceding Ediacaran period. De-Gan Shu, Simon Conway Morris et al. found on its branches what they considered rows of cilia, used for filter fee...
The relationship of ctenophores to the rest of Metazoa is very important to our understanding of the early evolution of animals and the origin of multicellularity. It has been the focus of debate for many years. Ctenophores have been purported to be the sister lineage to the Bilateria, sister to the Cnidaria, sister to...
Since all modern ctenophores except the beroids have cydippid-like larvae, it has widely been assumed that their last common ancestor also resembled cydippids, having an egg-shaped body and a pair of retractable tentacles. Richard Harbison's purely morphological analysis in 1985 concluded that the cydippids are not mon...
Fresno (/ˈfrɛznoʊ/ FREZ-noh), the county seat of Fresno County, is a city in the U.S. state of California. As of 2015, the city's population was 520,159, making it the fifth-largest city in California, the largest inland city in California and the 34th-largest in the nation. Fresno is in the center of the San Joaquin V...
In 1872, the Central Pacific Railroad established a station near Easterby's—by now a hugely productive wheat farm—for its new Southern Pacific line. Soon there was a store around the station and the store grew the town of Fresno Station, later called Fresno. Many Millerton residents, drawn by the convenience of the rai...
Before World War II, Fresno had many ethnic neighborhoods, including Little Armenia, German Town, Little Italy, and Chinatown. In 1940, the Census Bureau reported Fresno's population as 94.0% white, 3.3% black and 2.7% Asian. (Incongruously, Chinatown was primarily a Japanese neighborhood and today Japanese-American bu...
In September 1958, Bank of America launched a new product called BankAmericard in Fresno. After a troubled gestation during which its creator resigned, BankAmericard went on to become the first successful credit card; that is, a financial instrument that was usable across a large number of merchants and also allowed ca...
In the 1970s, the city was the subject of a song, "Walking Into Fresno", written by Hall Of Fame guitarist Bill Aken and recorded by Bob Gallion of the world-famous "WWVA Jamboree" radio and television show in Wheeling, West Virginia. Aken, adopted by Mexican movie actress Lupe Mayorga, grew up in the neighboring town ...
Fresno has three large public parks, two in the city limits and one in county land to the southwest. Woodward Park, which features the Shinzen Japanese Gardens, numerous picnic areas and several miles of trails, is in North Fresno and is adjacent to the San Joaquin River Parkway. Roeding Park, near Downtown Fresno, is ...
Between the 1880s and World War II, Downtown Fresno flourished, filled with electric Street Cars, and contained some of the San Joaquin Valley's most beautiful architectural buildings. Among them, the original Fresno County Courthouse (demolished), the Fresno Carnegie Public Library (demolished), the Fresno Water Tower...
Fulton Street in Downtown Fresno was Fresno's main financial and commercial district before being converted into one of the nation's first pedestrian malls in 1964. Renamed the Fulton Mall, the area contains the densest collection of historic buildings in Fresno. While the Fulton Mall corridor has suffered a sharp decl...
The neighborhood of Sunnyside is on Fresno's far southeast side, bounded by Chestnut Avenue to the West. Its major thoroughfares are Kings Canyon Avenue and Clovis Avenue. Although parts of Sunnyside are within the City of Fresno, much of the neighborhood is a "county island" within Fresno County. Largely developed in ...
The popular neighborhood known as the Tower District is centered around the historic Tower Theatre, which is included on the National List of Historic Places. The theater was built in 1939 and is at Olive and Wishon Avenues in the heart of the Tower District. (The name of the theater refers to a well-known landmark wat...
This vibrant and culturally diverse area of retail businesses and residences experienced a renewal after a significant decline in the late 1960s and 1970s.[citation needed] After decades of neglect and suburban flight, the neighborhood revival followed the re-opening of the Tower Theatre in the late 1970s, which at tha...
The neighborhood features restaurants, live theater and nightclubs, as well as several independent shops and bookstores, currently operating on or near Olive Avenue, and all within a few hundred feet of each other. Since renewal, the Tower District has become an attractive area for restaurant and other local businesses...
The area is also known for its early twentieth century homes, many of which have been restored in recent decades. The area includes many California Bungalow and American Craftsman style homes, Spanish Colonial Revival Style architecture, Mediterranean Revival Style architecture, Mission Revival Style architecture, and ...
Homes from the early 20th century line this boulevard in the heart of the historic Alta Vista Tract. The section of Huntington Boulevard between First Street on the west to Cedar Avenue on the east is the home to many large, stately homes. The original development of this area began circa 1910, on 190 acres of what had...
The "West Side" of Fresno, also often called "Southwest Fresno", is one of the oldest neighborhoods in the city. The neighborhood lies southwest of the 99 freeway (which divides it from Downtown Fresno), west of the 41 freeway and south of Nielsen Ave (or the newly constructed 180 Freeway), and extends to the city limi...
The neighborhood includes Kearney Boulevard, named after early 20th century entrepreneur and millionaire M. Theo Kearney, which extends from Fresno Street in Southwest Fresno about 20 mi (32 km) west to Kerman, California. A small, two-lane rural road for most of its length, Kearney Boulevard is lined with tall palm tr...
While many homes in the neighborhood date back to the 1930s or before, the neighborhood is also home to several public housing developments built between the 1960s and 1990s by the Fresno Housing Authority. The US Department of Housing and Urban Development has also built small subdivisions of single-family homes in th...
In the north eastern part of Fresno, Woodward Park was founded by the late Ralph Woodward, a long-time Fresno resident. He bequeathed a major portion of his estate in 1968 to provide a regional park and bird sanctuary in Northeast Fresno. The park lies on the South bank of the San Joaquin River between Highway 41 and F...
Formed in 1946, Sierra Sky Park Airport is a residential airport community born of a unique agreement in transportation law to allow personal aircraft and automobiles to share certain roads. Sierra Sky Park was the first aviation community to be built[citation needed] and there are now numerous such communities across ...
Fresno is marked by a semi-arid climate (Köppen BSh), with mild, moist winters and hot and dry summers, thus displaying Mediterranean characteristics. December and January are the coldest months, and average around 46.5 °F (8.1 °C), and there are 14 nights with freezing lows annually, with the coldest night of the year...
The official record high temperature for Fresno is 115 °F (46.1 °C), set on July 8, 1905, while the official record low is 17 °F (−8 °C), set on January 6, 1913. The average windows for 100 °F (37.8 °C)+, 90 °F (32.2 °C)+, and freezing temperatures are June 1 thru September 13, April 26 thru October 9, and December 10 ...
The 2010 United States Census reported that Fresno had a population of 494,665. The population density was 4,404.5 people per square mile (1,700.6/km²). The racial makeup of Fresno was 245,306 (49.6%) White, 40,960 (8.3%) African American, 8,525 (1.7%) Native American, 62,528 (12.6%) Asian (3.6% Hmong, 1.7% Indian, 1.2...
There were 158,349 households, of which 68,511 (43.3%) had children under the age of 18 living in them, 69,284 (43.8%) were opposite-sex married couples living together, 30,547 (19.3%) had a female householder with no husband present, 11,698 (7.4%) had a male householder with no wife present. There were 12,843 (8.1%) u...
As of the census of 2000, there were 427,652 people, 140,079 households, and 97,915 families residing in the city. The population density was 4,097.9 people per square mile (1,582.2/km²). There were 149,025 housing units at an average density of 1,427.9 square miles (3,698 km2). The racial makeup of the city was 50.2% ...
To avoid interference with existing VHF television stations in the San Francisco Bay Area and those planned for Chico, Sacramento, Salinas, and Stockton, the Federal Communications Commission decided that Fresno would only have UHF television stations. The very first Fresno television station to begin broadcasting was ...
Fresno is served by State Route 99, the main north/south freeway that connects the major population centers of the California Central Valley. State Route 168, the Sierra Freeway, heads east to the city of Clovis and Huntington Lake. State Route 41 (Yosemite Freeway/Eisenhower Freeway) comes into Fresno from Atascadero ...
Fresno is the largest U.S. city not directly linked to an Interstate highway. When the Interstate Highway System was created in the 1950s, the decision was made to build what is now Interstate 5 on the west side of the Central Valley, and thus bypass many of the population centers in the region, instead of upgrading wh...
Passenger rail service is provided by Amtrak San Joaquins. The main passenger rail station is the recently renovated historic Santa Fe Railroad Depot in Downtown Fresno. The Bakersfield-Stockton mainlines of the Burlington Northern Santa Fe Railway and Union Pacific Railroad railroads cross in Fresno, and both railroad...
Starting in the late 1950s, American computer scientist Paul Baran developed the concept Distributed Adaptive Message Block Switching with the goal to provide a fault-tolerant, efficient routing method for telecommunication messages as part of a research program at the RAND Corporation, funded by the US Department of D...
Packet switching contrasts with another principal networking paradigm, circuit switching, a method which pre-allocates dedicated network bandwidth specifically for each communication session, each having a constant bit rate and latency between nodes. In cases of billable services, such as cellular communication service...
Packet mode communication may be implemented with or without intermediate forwarding nodes (packet switches or routers). Packets are normally forwarded by intermediate network nodes asynchronously using first-in, first-out buffering, but may be forwarded according to some scheduling discipline for fair queuing, traffic...
Baran developed the concept of distributed adaptive message block switching during his research at the RAND Corporation for the US Air Force into survivable communications networks, first presented to the Air Force in the summer of 1961 as briefing B-265, later published as RAND report P-2626 in 1962, and finally in re...
Starting in 1965, Donald Davies at the National Physical Laboratory, UK, independently developed the same message routing methodology as developed by Baran. He called it packet switching, a more accessible name than Baran's, and proposed to build a nationwide network in the UK. He gave a talk on the proposal in 1966, a...
In connectionless mode each packet includes complete addressing information. The packets are routed individually, sometimes resulting in different paths and out-of-order delivery. Each packet is labeled with a destination address, source address, and port numbers. It may also be labeled with the sequence number of the ...
Connection-oriented transmission requires a setup phase in each involved node before any packet is transferred to establish the parameters of communication. The packets include a connection identifier rather than address information and are negotiated between endpoints so that they are delivered in order and with error...
Both X.25 and Frame Relay provide connection-oriented operations. But X.25 does it at the network layer of the OSI Model. Frame Relay does it at level two, the data link layer. Another major difference between X.25 and Frame Relay is that X.25 requires a handshake between the communicating parties before any user packe...
ARPANET and SITA HLN became operational in 1969. Before the introduction of X.25 in 1973, about twenty different network technologies had been developed. Two fundamental differences involved the division of functions and tasks between the hosts at the edge of the network and the network core. In the datagram system, th...
AppleTalk was a proprietary suite of networking protocols developed by Apple Inc. in 1985 for Apple Macintosh computers. It was the primary protocol used by Apple devices through the 1980s and 90s. AppleTalk included features that allowed local area networks to be established ad hoc without the requirement for a centra...
The CYCLADES packet switching network was a French research network designed and directed by Louis Pouzin. First demonstrated in 1973, it was developed to explore alternatives to the early ARPANET design and to support network research generally. It was the first network to make the hosts responsible for reliable deliv...
DECnet is a suite of network protocols created by Digital Equipment Corporation, originally released in 1975 in order to connect two PDP-11 minicomputers. It evolved into one of the first peer-to-peer network architectures, thus transforming DEC into a networking powerhouse in the 1980s. Initially built with three laye...
In 1965, at the instigation of Warner Sinback, a data network based on this voice-phone network was designed to connect GE's four computer sales and service centers (Schenectady, Phoenix, Chicago, and Phoenix) to facilitate a computer time-sharing service, apparently the world's first commercial online service. (In add...
Merit Network, Inc., an independent non-profit 501(c)(3) corporation governed by Michigan's public universities, was formed in 1966 as the Michigan Educational Research Information Triad to explore computer networking between three of Michigan's public universities as a means to help the state's educational and economi...
Telenet was the first FCC-licensed public data network in the United States. It was founded by former ARPA IPTO director Larry Roberts as a means of making ARPANET technology public. He had tried to interest AT&T in buying the technology, but the monopoly's reaction was that this was incompatible with their future. Bol...
Tymnet was an international data communications network headquartered in San Jose, CA that utilized virtual call packet switched technology and used X.25, SNA/SDLC, BSC and ASCII interfaces to connect host computers (servers)at thousands of large companies, educational institutions, and government agencies. Users typic...
There were two kinds of X.25 networks. Some such as DATAPAC and TRANSPAC were initially implemented with an X.25 external interface. Some older networks such as TELENET and TYMNET were modified to provide a X.25 host interface in addition to older host connection schemes. DATAPAC was developed by Bell Northern Research...
AUSTPAC was an Australian public X.25 network operated by Telstra. Started by Telecom Australia in the early 1980s, AUSTPAC was Australia's first public packet-switched data network, supporting applications such as on-line betting, financial applications — the Australian Tax Office made use of AUSTPAC — and remote term...
Datanet 1 was the public switched data network operated by the Dutch PTT Telecom (now known as KPN). Strictly speaking Datanet 1 only referred to the network and the connected users via leased lines (using the X.121 DNIC 2041), the name also referred to the public PAD service Telepad (using the DNIC 2049). And because ...
The Computer Science Network (CSNET) was a computer network funded by the U.S. National Science Foundation (NSF) that began operation in 1981. Its purpose was to extend networking benefits, for computer science departments at academic and research institutions that could not be directly connected to ARPANET, due to fun...
Internet2 is a not-for-profit United States computer networking consortium led by members from the research and education communities, industry, and government. The Internet2 community, in partnership with Qwest, built the first Internet2 Network, called Abilene, in 1998 and was a prime investor in the National LambdaR...
The National Science Foundation Network (NSFNET) was a program of coordinated, evolving projects sponsored by the National Science Foundation (NSF) beginning in 1985 to promote advanced research and education networking in the United States. NSFNET was also the name given to several nationwide backbone networks operati...
The Very high-speed Backbone Network Service (vBNS) came on line in April 1995 as part of a National Science Foundation (NSF) sponsored project to provide high-speed interconnection between NSF-sponsored supercomputing centers and select access points in the United States. The network was engineered and operated by MCI...
The Black Death is thought to have originated in the arid plains of Central Asia, where it then travelled along the Silk Road, reaching Crimea by 1343. From there, it was most likely carried by Oriental rat fleas living on the black rats that were regular passengers on merchant ships. Spreading throughout the Mediterra...
The plague disease, caused by Yersinia pestis, is enzootic (commonly present) in populations of fleas carried by ground rodents, including marmots, in various areas including Central Asia, Kurdistan, Western Asia, Northern India and Uganda. Nestorian graves dating to 1338–39 near Lake Issyk Kul in Kyrgyzstan have inscr...
Plague was reportedly first introduced to Europe via Genoese traders at the port city of Kaffa in the Crimea in 1347. After a protracted siege, during which the Mongol army under Jani Beg was suffering from the disease, the army catapulted the infected corpses over the city walls of Kaffa to infect the inhabitants. The...
From Italy, the disease spread northwest across Europe, striking France, Spain, Portugal and England by June 1348, then turned and spread east through Germany and Scandinavia from 1348 to 1350. It was introduced in Norway in 1349 when a ship landed at Askøy, then spread to Bjørgvin (modern Bergen) and Iceland. Finally ...
The plague struck various countries in the Middle East during the pandemic, leading to serious depopulation and permanent change in both economic and social structures. As it spread to western Europe, the disease entered the region from southern Russia also. By autumn 1347, the plague reached Alexandria in Egypt, proba...
Gasquet (1908) claimed that the Latin name atra mors (Black Death) for the 14th-century epidemic first appeared in modern times in 1631 in a book on Danish history by J.I. Pontanus: "Vulgo & ab effectu atram mortem vocatibant. ("Commonly and from its effects, they called it the black death"). The name spread through Sc...
Medical knowledge had stagnated during the Middle Ages. The most authoritative account at the time came from the medical faculty in Paris in a report to the king of France that blamed the heavens, in the form of a conjunction of three planets in 1345 that caused a "great pestilence in the air". This report became the f...
The dominant explanation for the Black Death is the plague theory, which attributes the outbreak to Yersinia pestis, also responsible for an epidemic that began in southern China in 1865, eventually spreading to India. The investigation of the pathogen that caused the 19th-century plague was begun by teams of scientist...
The historian Francis Aidan Gasquet wrote about the 'Great Pestilence' in 1893 and suggested that "it would appear to be some form of the ordinary Eastern or bubonic plague". He was able to adopt the epidemiology of the bubonic plague for the Black Death for the second edition in 1908, implicating rats and fleas in the...
Other forms of plague have been implicated by modern scientists. The modern bubonic plague has a mortality rate of 30–75% and symptoms including fever of 38–41 °C (100–106 °F), headaches, painful aching joints, nausea and vomiting, and a general feeling of malaise. Left untreated, of those that contract the bubonic pla...
In October 2010, the open-access scientific journal PLoS Pathogens published a paper by a multinational team who undertook a new investigation into the role of Yersinia pestis in the Black Death following the disputed identification by Drancourt and Raoult in 1998. They assessed the presence of DNA/RNA with Polymerase ...
The study also found that there were two previously unknown but related clades (genetic branches) of the Y. pestis genome associated with medieval mass graves. These clades (which are thought to be extinct) were found to be ancestral to modern isolates of the modern Y. pestis strains Y. p. orientalis and Y. p. medieval...
The results of the Haensch study have since been confirmed and amended. Based on genetic evidence derived from Black Death victims in the East Smithfield burial site in England, Schuenemann et al. concluded in 2011 "that the Black Death in medieval Europe was caused by a variant of Y. pestis that may no longer exist." ...
The plague theory was first significantly challenged by the work of British bacteriologist J. F. D. Shrewsbury in 1970, who noted that the reported rates of mortality in rural areas during the 14th-century pandemic were inconsistent with the modern bubonic plague, leading him to conclude that contemporary accounts were...
It is recognised that an epidemiological account of the plague is as important as an identification of symptoms, but researchers are hampered by the lack of reliable statistics from this period. Most work has been done on the spread of the plague in England, and even estimates of overall population at the start vary by...
In addition to arguing that the rat population was insufficient to account for a bubonic plague pandemic, sceptics of the bubonic plague theory point out that the symptoms of the Black Death are not unique (and arguably in some accounts may differ from bubonic plague); that transference via fleas in goods was likely to...