Posts Tagged ‘Africa’
African Rat Smears Poison On Its Fur to Protect Itself From Predators
The first mammal (except for humans) known to do such a thing
The African crested rat is the only known mammal to use a lethal plant toxin for its own defense, according to researchers in England, the US and Kenya. It chews up the bark of the Acokanthera tree, the same tree East African hunters use to make poison darts, and rubs the saliva on its flanks.
Researchers thought the rat itself was poisonous, because it displays a black and white coloration on its flanks (much like a skunk) when it’s threatened by a predator. Also, scientists have reported accounts of dogs getting sick and dying after coming into contact with the rats, which are also called maned rats.
But instead of producing poison itself, the rat grabs it from nature, researchers say. The hair on its flanks is perforated, helping it soak up the poisonous spit.
To test their theory, scientists from the Wildlife Conservation Society, the University of Oxford and the National Museum of Kenya tested a wild-caught rat. They gave it some branches and roots from the Acokanthera tree, and the rat proceeded to start gnawing the bark. Then it rubbed the saliva on itself.
The bark releases a compound called ouabain, which is used for poison arrows but also, oddly, to treat congestive heart failure, according to the .
Researchers are still not sure how the rodent is able to chew up the poisonous material without getting sick itself. But it’s a pretty effective tool to protect the 2-pound rat from predators.
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Video: Microdrone Goes On Safari, Buzzing Kenyan Wildlife To Capture Footage
The German surveillance bot maker Microdrones took one of their md4-1000 quadcopters to the Masai Mara region of the Serengeti, and used it to capture video of all sorts of African wildlife. Here’s a preview of what their drone saw.
This is apparently a production for TBS Television Japan, according to Microdrones’ YouTube feed. It looks like “Planet Earth” but with robots.
Small surveillance drones are great for entering areas where humans can’t or shouldn’t tread, and African wildlife preserves are no exception. The creatures even seemed pretty unfazed by the hovering intruder, which could be less invasive than a mud-caked Land Rover. But it would have been even cooler if one of the elephants grabbed it with a trunk.
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New Scanner Tracks Zebras’ Built-In Bar Codes
A new algorithm can like they were bar codes, helping researchers track individual animals more easily.
“StripeSpotter,” designed at the University of Illinois-Chicago and Princeton University, will help researchers build biometric databases based on field photographs. The programmers are building a zebra-print database for Plains and Grevys zebras in Kenya.
users would only need a digital camera and a laptop capable of running the simple program. Take a picture of a zebra, and the StripeCode algorithm extracts certain image features, using a dynamic programming algorithm to compare them and search for a match. This way, ecologists can determine whether an animal has been observed before, and then take field notes, GPS coordinates and other information. If there is no match, the assumption is that the zebra has never been spotted before.
It could also be used for other striped animals like tigers and giraffes, the researchers say.
The system is described in a to be presented this month at the International Conference on Multimedia Retrieval.
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Infecting Mosquitoes With Genetically Altered Fungus Curbs Malaria Parasite
Researchers at the University of Maryland, who were funded by the National Institutes of Health/National Institute of Allergy and Infectious Diseases, say the method could be an effective treatment against malaria, especially as mosquitoes increasingly evolve to resist insecticides. Even better, the fungus modification can be targeted to almost any disease-carrying insect, potentially allowing fungus-based prevention for maladies like Lyme disease or dengue fever. The study was reported today in the journal Science.
The Metarhizium anisopliae fungus naturally attacks mosquitoes, and it has already been used to reduce disease transmission — but it only works if the bugs are sprayed with fungus soon after they picked up the malaria-causing Plasmodium falciparum parasite. What’s more, the mosquitoes often die before reproducing, leaving fungus-resistant mosquitoes to take over and render the spray useless. So rather than enhance fungi to better kill mosquitoes, entomology professor Raymond St. Leger and colleagues modified the fungi to block the development of Plasmodium in the mosquito.
They used genes for a human antibody and a scorpion toxin, both of which specifically target Plasmodium, and inserted them into the fungus. They fed some mosquitoes a Plasmodium-infected blood meal, and separated them into three groups. One group got a dose of the transgenic fungus, another got a natural fungus and the third was not sprayed at all. Two weeks after the bugs were exposed to the malaria parasite, the researchers checked for its presence in their salivary glands (this is how it’s transmitted to humans).
Spraying mosquitoes with the transgenic fungus significantly reduced parasite development, the team found.
Malaria is found in 106 countries and there are an estimated 225 million malaria cases every year, including 781,000 deaths, mostly in sub-Saharan Africa. Prevention usually involves spraying bed nets and interior walls with pyrethroid insecticide to kill the mosquitoes, but the bugs are evolving to resist it, and there are no promising prospects for a chemical replacement.
Other teams have to resist Plasmodium, and modified other mosquitoes in order to reduce their populations. But transgenic mosquitoes could . A fungal treatment can be modified to keep up with mosquitoes’ natural adaptations, St. Leger said.
“Mosquitoes have an incredible ability to evolve and adapt, so there may be no permanent fix. However, our current transgenic combination could translate into additional decades of effective use of fungi as an anti-malarial biopesticide,” he said.
Video: Creepy Madagascan Beasts Rub Their Back Hairs Together To Make Squeaks
Weird tenrecs caught on camera for the first time
The animals have special quills on their backs, which look like pale teeth and are noticeably different from the rest of its coarse fur and porcupine-like spines. When a young tenrec gets lost, as in the video below, its family members rub these quills together to produce high-pitched squeaks. The sound penetrates the rainforest undergrowth to help guide the tenrec back to its kin.
About 30 species of tenrecs are found throughout Madagascar, with a few living on the African mainland. The animals share a common ancestor with elephants, aardvarks and manatees. But the only one to communicate in this way is the lowland streaked tenrec, found only in Madagascar.
Their communications are mostly outside the range of human hearing, so filmmakers used to ensure they could pick up the tenrecs' ultrasonic calls. They found that the seemingly quiet creatures were actually quite chatty.
From lemurs to fossas, Madagascar is home to a vast array of weird animals — but this one takes the cake. Watch the stridulations in this video clip narrated by David Attenborough.
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Sproxil takes on Africa’s drug counterfeiters
Not many tech startups save lives. may be one of them.
The company tags pharmaceutical products in emerging markets with a scratch-off code which is verified by sending a text message to Sproxil’s product authentication service. Sproxil was one of two companies to receive an honourable mention from the judges in the recent (having previously ) and was one of the most talked-about startups in the competition.
The World Health Organization (WHO) estimates that are counterfeit but that rate could be as high as 50 percent in some developing countries like Nigeria and Congo. WHO calculates that 200,000 of deaths caused by malaria alone could be prevented if all antimalarials were genuine. The U.S.-based Center for Medicines in the Public Interest (CMPI) projects that in 2010, counterfeit drugs will be , an increase of more than 92 percent from 2005.
Drug companies have developed myriad methods to verify the authenticity of their products including RFIDs, barcodes and holograms on packaging, chemical tests and laser scanning. Unfortunately, most of these methods have either been compromised or are too expensive for use in emerging markets. Sproxil uses simple scratch-off codes, of the type used to top up pre-paid cell phones, attached to either the drug blister, packet or an entire pallet depending on who needs to validate the product’s authenticity. The code is single use and is sent by text message to Sproxil’s authentication service. In Nigeria, more than 1,400,000 pharmaceutical items have been labeled with Sproxil’s technology.
I talked to Sproxil’s CEO Ashifi Gogo about the market and business model. According to Gogo, Sproxil can provide the mobile authentication technology more cheaply than the pharma companies themselves, because it can aggregate multiple pharma clients. When asked about the other authentication methods most likely to compete with Sproxil’s technology, Gogo mentioned barcodes but pointed out that many phones in developing countries are not yet capable of photographing the barcode and sending it for authentication.
Currently, clients pay a few cents for each code and for the text messages. Since Sproxil currently gets a fee even if the user does not text the code, it generates revenue from unused texts. Gogo intends to switch from this flat fee model to a per transaction fee as the business grows. Sproxil also sends targeted ads to users who have authenticated a code. These ads have increased sales by 10 percent for one client in Nigeria in only 3 months.
Gogo foresees the authentication technology being used for other items such as wines and spirits (fake versions are a major problem in Asia, apparently) and luxury goods. Initially though, Sproxil plans to expand into Kenya and eventually India which has a huge counterfeit drug problem. Sproxil is not the only company out there using cell phones for verification. operates a similar scheme in Kenya.
Sproxil was founded in 2009, has 12 staff members and offices in Somerville, MA and Lagos, Nigeria. The company is privately funded and, according to Gogo, profitable.
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New Anti-HIV Gel For Women Cuts AIDS Virus Transmission Chances in Half, Study Says
The women involved in the study used it only 60 percent of the time, and it was still effective -- meaning an even greater prevention rate is possible if it's used more frequently.
The study was published online Monday in Science.
The results still need to be confirmed, and scientists disagree about whether the protection it offers is sufficient to justify using the gel right away. But it's a major step in the fight to provide women another method besides condoms to protect themselves from infection. It's especially important in sub-Saharan Africa, where more than two-thirds of the world's HIV infections occur, .
Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, tells AP the gel marks the first time researchers have seen any microbicide make a statistically significant impact.
The gel was announced at the International AIDS Conference in Vienna, where thousands of scientists, policymakers and activists are gathered. The next few days will include announcements about new drug therapies and genetic research, as well as discussions about funding for research and prevention.
The study involved 900 South African women who were administered a special gel spiked with the AIDS drug tenofovir. The gel cut the risk of HIV infection by 50 percent after one year of use and 39 percent after 2 1/2 years, compared to a gel that contained no medicine, according to the study. The women used the gel only 60 percent of the time, and those who used it more often had higher rates of protection. Scientists say more frequent use is key -- the gel does not need to be changed.
Of the 444 women who received a placebo gel, 60 became infected with HIV, versus 38 infections in the 445 women who received the microbicide, reports. That's a statistically significant difference, the researchers say.
The gel is in limited supply, but 99 percent of the women in the study said they'd definitely use it if they knew it prevented the spread of HIV.
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