Schistosoma haematobium (urinary blood fluke) mated pair (WIP)
Models created with 3ds Max and ZBrush for the urinary blood fluke animation.
After blood fluke larvae hatch, males (brown) and females (purple) pair off, with the larger males cradling the thinner females within their gynaecophoric canal.
The mated pair travel through the blood vessels until they reach the arteries surrounding the bladder. This is where the female will lay her eggs.
this is awesome
A blueprint for restoring touch with a prosthetic hand
New research at the University of Chicago is laying the groundwork for touch-sensitive prosthetic limbs that one day could convey real-time sensory information to amputees via a direct interface with the brain.
he research, published early online in theProceedings of the National Academy of Sciences, marks an important step toward new technology that, if implemented successfully, would increase the dexterity and clinical viability of robotic prosthetic limbs.
"To restore sensory motor function of an arm, you not only have to replace the motor signals that the brain sends to the arm to move it around, but you also have to replace the sensory signals that the arm sends back to the brain," said the study’s senior author, Sliman Bensmaia, PhD, assistant professor in the Department of Organismal Biology and Anatomy at the University of Chicago. "We think the key is to invoke what we know about how the brain of the intact organism processes sensory information, and then try to reproduce these patterns of neural activity through stimulation of the brain.”
Bensmaia’s research is part of Revolutionizing Prosthetics, a multi-year Defense Advanced Research Projects Agency (DARPA) project that seeks to create a modular, artificial upper limb that will restore natural motor control and sensation in amputees. Managed by the Johns Hopkins University Applied Physics Laboratory, the project has brought together an interdisciplinary team of experts from academic institutions, government agencies and private companies.
Bensmaia and his colleagues at the University of Chicago are working specifically on the sensory aspects of these limbs. In a series of experiments with monkeys, whose sensory systems closely resemble those of humans, they indentified patterns of neural activity that occur during natural object manipulation and then successfully induced these patterns through artificial means.
The first set of experiments focused on contact location, or sensing where the skin has been touched. The animals were trained to identify several patterns of physical contact with their fingers. Researchers then connected electrodes to areas of the brain corresponding to each finger and replaced physical touches with electrical stimuli delivered to the appropriate areas of the brain. The result: The animals responded the same way to artificial stimulation as they did to physical contact.
Next the researchers focused on the sensation of pressure. In this case, they developed an algorithm to generate the appropriate amount of electrical current to elicit a sensation of pressure. Again, the animals’ response was the same whether the stimuli were felt through their fingers or through artificial means.
Finally, Bensmaia and his colleagues studied the sensation of contact events. When the hand first touches or releases an object, it produces a burst of activity in the brain. Again, the researchers established that these bursts of brain activity can be mimicked through electrical stimulation.
The result of these experiments is a set of instructions that can be incorporated into a robotic prosthetic arm to provide sensory feedback to the brain through a neural interface. Bensmaia believes such feedback will bring these devices closer to being tested in human clinical trials.
"The algorithms to decipher motor signals have come quite a long way, where you can now control arms with seven degrees of freedom. It’s very sophisticated. But I think there’s a strong argument to be made that they will not be clinically viable until the sensory feedback is incorporated,” Bensmaia said. “When it is, the functionality of these limbs will increase substantially.”
The Defense Advanced Research Projects Agency, National Science Foundation and National Institutes of Health funded this study. Additional authors include Gregg Tabot, John Dammann, Joshua Berg and Jessica Boback from the University of Chicago; and Francesco Tenore and R. Jacob Vogelstein from the Johns Hopkins University Applied Physics Laboratory.
To pinpoint why depression messes with memory, researchers took a page from Sesame Street’s book.
The show’s popular game “One of these things is not like the others” helps young viewers learn to differentiate things that are similar – a process known as “pattern separation.”
A new Brigham Young University study concludes that this same skill fades in adults in proportion to the severity of their symptoms of depression. The more depressed someone feels, the harder it is for them to distinguish similar experiences they’ve had.
If you’ve ever forgotten where you parked the car, you know the feeling (though it doesn’t mean you have depression).
“That’s really the novel aspect of this study – that we are looking at a very specific aspect of memory,” said Brock Kirwan, a psychology and neuroscience professor at BYU.
Depression has been generally linked to poor memory for a long time. To find out why, Kirwan and his former grad student D.J. Shelton put people through a computer-aided memory test. The participants viewed a series of objects on the screen. For each one, they responded whether they had seen the object before on the test (old), seen something like it (similar), or not seen anything like it (new).
With old and new items, participants with depression did just fine. They often got it wrong, however, when looking at objects that were similar to something they had seen previously. The most common incorrect answer was that they had seen the object before.
“They don’t have amnesia,” Kirwan said. “They are just missing the details.”
This can be a challenge in a number of everyday situations, such as trying to remember which friends and family members you’ve told about something personal – and which ones are still in the dark.
The findings also give an important clue about what is happening in the brain that might explain this.
“There are two areas in your brain where you grow new brain cells,” Kirwan said. “One is the hippocampus, which is involved in memory. It turns out that this growth is decreased in cases of depression.”
Because of this study, we know a little more about what these new brain cells are for: helping us see and remember new experiences. The study appears in the journal Behavioral Brain Research.
systemic lupus erythematosus, a chronic inflammatory autoimmune condition in which antibodies are produced against self-antigens (particularly nuclear proteins), causes widespread damage to multiple organs and tissues
the apparent “fusion” of erythrocytes seen above is one of the many pathological features of this disease
the malar, or “butterfly”, rash across the bridge of the nose and onto the cheekbones is another (well-known) characteristic of lupus
credit: Armen Y Gasparyan, Cell Picture Show, Cell
A new blood test can be used to discriminate between people with Alzheimer’s disease and healthy controls. It’s hoped the test, described in the open access journal Genome Biology, could one day be used to help diagnose the disease and other degenerative disorders.
Alzheimer’s disease, the most common form of dementia, can only be diagnosed with certainty at autopsy, so the hunt is on to find reliable, non-invasive biomarkers for diagnosis in the living. Andreas Keller and colleagues focused on microRNAs (miRNAs), small non-coding RNA molecules known to influence the way genes are expressed, and which can be found circulating in bodily fluids including blood.
The team, from Saarland University and Siemens Healthcare highlighted and tested a panel of 12 miRNAs, levels of which were found to be different amongst a small sample of Alzheimer’s patients and healthy controls. In a much bigger sample, the test reliably distinguished between the two groups.
Decent biomarkers need to be accurate, sensitive (able to correctly identify people with the disease) and specific (able to correctly pinpoint people without the disease). The new test scores over 90% on all three measures. But whilst the test shows obvious promise, it still needs to be validated for clinical use, and may eventually work best when combined with other standard diagnostic tools, such as imaging, the authors say.
As people with other brain disorders can sometimes show Alzheimer’s-like symptoms, the team also looked for the miRNA signature in other patient groups. The test distinguished controls from people with various psychological disorders, such as schizophrenia and depression, with over 95% accuracy, and from patients with other neurodegenerative disorders, such as mild cognitive impairment and Parkinson’s disease, with lower accuracy. It also discriminated between Alzheimer’s patients and patients with other neurodegenerative disorders, with an accuracy of around 75%. But by tweaking the miRNAs used in the test, accuracy could be improved.
The work builds on previous studies highlighting the potential of miRNAs as blood-based biomarkers for many diseases, including numerous cancers, and suggests that miRNAs could yield useful biomarkers for various brain disorders. But it also sheds light on the mechanisms underpinning Alzheimer’s disease. Two of the miRNAs are known involved in amyloid precursor protein processing, which itself is involved in the formation of plaques, a classic hallmark of Alzheimer’s disease. And many of the miRNAs are believed to influence the growth and shape of neurons in the developing brain.
Ay, gracias <3 En qué universidad estás?