Nice summary (and timely given West Africa’s current Ebola outbreak). Now while bats host a large number of pathogenic viruses and bacteria, they also provide crucial ecosystem services, such as pollination and insect control, estimated in billions of dollars!
Genetic analysis of hair samples attributed to yeti, bigfoot and other anomalous primates
In the first ever systematic genetic survey, we have used rigorous decontamination followed by mitochondrial 12S RNA sequencing to identify the species origin of 30 hair samples attributed to anomalous primates. Two Himalayan samples, one from Ladakh, India, the other from Bhutan, had their closest genetic affinity with a Paleolithic polar bear, Ursus maritimus. Otherwise the hairs were from a range of know extant mammals.
It could still be out there, right?!
Article in Proc B (http://bit.ly/1j1jv89)
Experts on rare and threatened species issue a warning that lemurs and slipper orchids are at risk of widespread extinction.
My friend is a AAAS Media Fellow writing for NatGeo this summer. Check out her stuff!
Bat Flight and Zoonotic Viruses
Bats are sources of high viral diversity and high-profile zoonotic viruses worldwide. Although apparently not pathogenic in their reservoir hosts, some viruses from bats severely affect other mammals, including humans. Examples include severe acute respiratory syndrome coronaviruses, Ebola and Marburg viruses, and Nipah and Hendra viruses. Factors underlying high viral diversity in bats are the subject of speculation. We hypothesize that flight, a factor common to all bats but to no other mammals, provides an intensive selective force for coexistence with viral parasites through a daily cycle that elevates metabolism and body temperature analogous to the febrile response in other mammals. On an evolutionary scale, this host–virus interaction might have resulted in the large diversity of zoonotic viruses in bats, possibly through bat viruses adapting to be more tolerant of the fever response and less virulent to their natural hosts.
Photo credit: Ian Waldie / Getty Images
A 50-cent microscope that folds together from a sheet of paper will make diagnosing diseases and citizen science disruptively accessible.
"Foldscope is an origami-based print-and-fold optical microscope that can be assembled from a flat sheet of paper. Although it costs less than a dollar in parts, it can provide over 2,000X magnification with sub-micron resolution (800nm), weighs less than two nickels (8.8 g), is small enough to fit in a pocket (70 × 20 × 2 mm3), requires no external power, and can survive being dropped from a 3-story building or stepped on by a person. Its minimalistic, scalable design is inherently application-specific instead of general-purpose gearing towards applications in global health, field based citizen science and K12-science education."
CAPTCHAs are a time-worn way for humans to tell computers that we are human. They are those little boxes filled with distorted text that we’ve been told humans can decipher, but computers—the bad guys’ computers—cannot. So, Watson-be-damned, we enter the letters and gain access to whatever is behind the veil, leaving the bad bots steaming outside the pearly, CAPTCHA’d gates. As Google’s ReCAPTCHA website puts it: “Tough on bots, easy on humans.”
It is a satisfying display of human superiority built into the daily experience of the web. And, BONUS, you’re often helping do optical character recognition on old books at the same time. Take that, Machines, you don’t even have any books.
But then along comes Google today noting, in a showily short and breezy blog post, that their machines can beat ReCAPTCHAs 99% of the time.
Let us welcome our CAPTCHA- and address-reading computer overlords.
Source: The Atlantic
The switch happened only 30 years ago; the bacteria now kills 500,000 per year.
Bacterial diseases cause millions of deaths every year. Most of these bacteria were benign at some point in their evolutionary past, and we don’t always understand what turned them into disease-causing pathogens. In a new study, researchers have tracked down when this switch happened in one flesh-eating bacteria. They think the knowledge might help predict future epidemics.
The flesh-eating culprit in question is called GAS, or Group A β-hemolytic streptococcus, a highly infective bacteria. Apart from causing the flesh-eating disease necrotizing fasciitis, GAS is also responsible for a range of less harmful infections. It affects more than 600 million people every year, and it causes an estimated 500,000 deaths.
These bacteria appeared to have affected humans since the 1980s. Scientists think that GAS must have evolved from a less harmful streptococcus strain. The new study, published in PNAS, reconstructs that evolutionary history.
Lead researcher James Musser of the Methodist Hospital Research Institute said, “This is the first time we have been able to pull back the curtain to reveal the mysterious processes that gives rise to a virulent pathogen.”
Photo: Streptococcus pyogenes / WikiCommons
Ever since our conception, humans have fallen victim to infectious disease - microscopic, airbourne pathogens and parasites that infiltrate our bodies and turn them against us. Shown above, and described below, are 10 of the deadliest pathogens humankind has encountered throughout history. Some, like poliovirus, show how far we’ve come - while others, such as HIV, remind us how far we have still to go in the battle against nature’s smallest assassins.
The Bubonic Plague: Also called the Black Death due to the formation of necrotic tissue on living victims, the bubonic plague - most commonly caused by a small bacterium, Yersinia pestis - is estimated to have killed around 75 million people, including half the total population of Europe. Although controlled, the bubonic plague is still endemic today.
Poliomyelitis: One of the most dreaded childhood diseases of the 20th century, the causitive agent of polio, poliovirus, has caused 10,000 deaths since 1916, and permanent paralysis to thousands. Its presence in the population is substantially reduced in the modern day due to an effective polio vaccine and vaccination programme.
Smallpox: Marked in history as the pathogen of choice for the first-ever documented case of biological warfare, in which smallpox-infected blankets were thrown into enemy camps, smallpox and its two viral agents - variola major (pictured above) and variola minor - decimated the Native American population in the United States from 12 million to 235,000. It is also credited with destroying the Aztec civilisation when brought to South America by the conquistadors. WHO declared the official eradication of smallpox in 1979, although samples are still stored in laboratories for research.
Cholera: Caused by the bacterium Vibrio cholerae, cholera is perhaps best known for being one of the most rapidly fatal illnesses known - a healthy person may become hypotensive within an hour of symptoms onset, and will die within 2-3 if no treatment is provided. Cholera has killed approximately 12,000 people since 1991.
Spanish Influenza: An especially virulent strain of Influenza A virus, subtype H1N1, killed 50 to 100 million people in the years 1918 and 1919 alone. Many of its victims were healthy young adults, in stark contrast to the flu of today, which usually preys on the old and infirm. The extraordinary death toll is believed to have resulted from the extreme virulence of the virus and the severity of symptoms, believed to have been caused by cytokine storms.
Tuberculosis: Caused by various strains of mycobacteria, most commonly Mycobacterium tuberculosis, tuberculosis is a usually lethal and sadly common infectious disease that affects up to 80% of the population in some African and Asian countries.
Influenza: Commonly known as the flu, influenza is caused by a massive family of RNA-based viruses of the family orthomyxoviridae. It causes about 36,000 deaths per year.
Malaria: Malaria is a vector-bourne infectious disease caused by protozoan parasites of the genus Plasmodium, typically Plasmodium falciparum and Plasmodium vivax. It causes approximately 2.7 million deaths per year, a large percentage of them young children in sub-Saharan Africa. No vaccine has yet been created for malaria; drugs must be taken continuously to reduce the risk of infection.
AIDS: Acquired Immunodeficiency Syndrome (AIDS) is caused by HIV, the human immunodeficiency virus. Death results from specific damage to the immune system, leaving people susceptible to opportunistic infection in the late stages. Although treatments exist to decelerate the virus’ progression, there is no known cure, and 21 million have died of AIDS since 1981. HIV is usually passed by blood-to-blood transmission.
Ebola: Ebola is a potentially lethal hemorrhagic fever that has caused approximately 1,600 human deaths. It is a zoonotic disease caused by the ebola virus whose primary animal vector is thought to be the fruit bat. Mortality rates are generally very high, in the region of 80% – 90%, with the cause of death usually due to hypovolemic shock or organ failure.
Images: Top left: Yersinia pestis. Top right: poliovirus. Second line, left: Variola major. Second line, center: Vibrio cholerae. Second line, right: Influenza A, subtype H1N1. Third line, left: Mycobacterium tuberuclosis. Third line, right: Influeza A. Bottom left: Plasmodium falciparum in red blood cells. Bottom center: HIV. Bottom right: Ebola virus.