Cells of prokaryotes have been viewed as very primitive, although some contain unusual enclosures known as microcompartments, which appear to serve as primitive organelles inside bacterial cells, carrying out special reactions in their interior.

"Students who take a biology class learn in the first three days that cells of prokaryotes are uniform and without organization, while cells of eukaryotes have a complex organization," Yeates said. "That contrast is becoming less stark; we are learning there is more of a continuum than a sharp divide. These microcompartments, which resemble viruses because they are built from thousands of protein subunits assembled into a shell-like architecture, are an important component of bacteria. I expect there will be a much greater focus on them now."

Yeates' Science paper reveals the first structures of the proteins that make up these shells, and the first high-resolution insights into how they function.

"Those microcompartments have remained shrouded in mystery, largely because of an absence of a detailed understanding of their architecture, of what the structures look like," said Yeates, who also is a member of the California NanoSystems Institute and UCLA's Molecular Biology Institute. "The complete three-dimensional structure is still unknown, but in this paper we have provided the first three-dimensional structure of the building blocks of the carboxysome, a protein shell which is the best-studied microcompartment..."

The structure of the carboxysome shows a repeating pattern of six protein molecules packed closely together.

"We didn't know six would be the magic number," Yeates said. "What surprises me is how nearly these six protein molecules fill the space between them. If you take six pennies and place them in the shape of a ring, that leaves a large space in the middle. Yet the shape of this protein molecule is such that when six proteins come together, they nearly fill the space; what struck me is how tightly packed they are. That tells us the shell plays an important role in controlling what comes in and goes out. When we saw how the many hexagons come together, we saw that they filled the space tightly as well."

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New research indicates that people shown erotic or gory images frequently fail to process what they see immediately afterwards.

Portions of the research exploring this effect by Vanderbilt University psychologist David Zald and Yale University researchers Steven Most, Marvin Chun and David Widders will be published in the August issue of Psychonomic Bulletin and Review...

Zald and his colleagues set out to determine if the rubbernecking effect carries over into more minute lapses of attention through two separate experiments.

In the first experiment, research subjects were shown hundreds of pictures that included a mix of disturbing images along with landscape or architectural photos. They were told to search the images for a particular target image. An irrelevant, emotionally negative or neutral picture preceded the target by two to eight items. The closer the negative pictures were to the target image, the more frequently the subject failed to spot the target. In a subsequent study, which has not yet been published, the researchers substituted erotic for negative images and found the same basic effect.

"We think that there is essentially a bottleneck for information processing and if a certain type of stimulus captures attention, it can basically jam up that bottleneck so subsequent information can't get through," Zald said. "It appears to happen involuntarily..."

In the second experiment, the researchers sought to determine if individuals can override their emotion-induced blindness by focusing more deliberately on the target for which they are searching. In this experiment, the subjects undertook two different trials. In one they were told specifically to look for a rotated photo of a building; in the other they were told to look for a rotated photo of either a building or a landscape.

The research team hypothesized that the more specific instruction-to look for the building only-would help the research subjects override their emotion-induced blindness. After running the tests, the researchers discovered that they were partially right: specific instructions helped some subjects control their attention, but it didn't help others.

You, animal, you!

The press release...

Genetics researchers have developed a customized gene chip to rapidly scan tumor samples for specific DNA changes that offer clues to prognosis in cases of neuroblastoma, a common form of children's cancer. Rather than covering the entire genome, the microarray focuses on suspect regions of chromosomes for signs of deleted genetic material known to play a role in the cancer.

The investigators, from The Children's Hospital of Philadelphia and Thomas Jefferson University, say their technique may be readily adapted for other types of cancer. The proof-of-principle study appears in the August issue of Genome Research.

One advantage of their technique is its flexibility, said co-author John M. Maris, M.D., a pediatric oncologist at The Children's Hospital of Philadelphia. "As future research identifies other genes active in neuroblastoma, we can modify the microarray to include such regions," he added...

Microarrays are silicon chips that contain tightly ordered selections of genetic material upon which sample material can be tested. When DNA bases from a sample bind to complementary sequences on the microarray, they cause fluorescent tags to shine under laser light. This is a signal that a particular gene variation is present in the sample.

"We can test DNA from peripheral blood and from the tumor, and we should see a loss of signal in the cancer," said Dr. Fortina. He noted that the researchers can simultaneously evaluate seven chromosomal regions known to be involved in neuroblastoma.

Unlike gene expression microarrays, which detect varying levels of RNA to measure the activity levels of different genes as DNA transfers information to RNA, the current microarray directly identifies changes in DNA. "These DNA changes, involving gain or loss of genetic material, are important for neuroblastoma prognosis," said Dr. Maris.

Researchers also report that this technique could potentially be used to identify other forms of cancer.

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In a study published in the latest issue of Current Biology, the UCL team found that brain activity measured in volunteers who were viewing a visual illusion could be used to accurately track their subjective experience while it underwent many spontaneous changes.

In the study, funded by the Wellcome Trust, John-Dylan Haynes and Geraint Rees presented volunteers with a visual illusion known as "binocular rivalry". When very different images are presented separately to each eye, they compete for access to consciousness. Volunteers experience many spontaneous switches in their awareness, sometimes seeing one image and sometimes the other.

While volunteers experienced these spontaneous switches in awareness, the UCL team measured patterns of activity in their brains using functional MRI (fMRI) brain scanning. They found that brain activity could be used to blindly predict with high precision which of the two images a volunteer was perceiving, and how their conscious perception changed over several minutes of viewing. The study thus shows that it is possible to predict the changing stream of consciousness from brain activity alone.

Dr John-Dylan Haynes of the UCL Institute of Neurology says: "Previous research on visual perception has tended to focus on perception of static, unchanging scenes, ignoring the fact that our stream of consciousness is highly dynamic and our perception changes from second to second.

"Our study represents an important but very early stage step towards eventually building a machine that can track a person's consciousness on a second-by-second basis."

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Stricter eligibility criteria are making it even harder to find patients. Often only patients with a specific condition can join the pivotal phase of a trial - the largest, most important and most costly phase of a trial to show if the drug or device really works. On average, about one in 20 prospective patients alerted about a trial actually qualify for and enroll in it, McDonald said.

A decade ago, two of three patients enrolled in a trial at the suggestion of their doctor or nurse; now doctors refer about one in four. Patients are less willing to blindly follow their doctor's advice, McDonald said.

Plus, "there are so many clinical trials, it is hard for doctors to keep them all on their radar," said Mark Summers, chief executive of 3-Wire, a firm that helps drug and device companies recruit and retain patients in their clinical trials.

Old-fashioned methods of getting rid of head lice in children are far more effective than current chemical treatments, researchers revealed yesterday (FRI).

Using a fine-tooth comb and conditioner on wet hair was four times more effective than popular chemical-based treatments like lotions and shampoo.

London School of Hygiene & Tropical Medicine (LSHTM) researcher Dr Nigel Hill said: "Millions of pounds are spent each year by desperate parents or through NHS prescriptions on lice treatments and many seem to be virtually useless.

"It's clear insecticide treatments are not working very well at all and if you speak to parents and school nurses they will confirm that..."

The research team at LSHTM tested the "bug busting" fine tooth comb method and chemical treatments in a group of 126 children with head lice.

A total of 56 were allocated the comb-and-conditioner "Bug Buster" kit, while 70 were given insecticide-based treatments. The results were assessed two to four days after the end of treatment.

Questionnaires to determine compliance with the instructions, satisfaction and to obtain background information were also filled out by parents. The results are published in this week's edition of the prestigious British Medical Journal.

The "Bug Buster" treatment showed a 57 percent success rate compared to just 13 percent for insecticide treatment.

The press release...

... a new University of Michigan Health System study shows that simply having nurses flag patients' records with a written reminder can jog the memory of busy doctors, prompt them to consider removing the catheter, and lead to a much shorter time with a catheter for many patients. The study is published in the August issue of the Joint Commission Journal on Quality and Patient Safety.

The written-reminder system isn't expensive, and in fact the study finds that its cost equals or is less than the savings that a hospital could achieve by reducing infections among patients. An estimated 40 percent of infections developed by patients during their hospital stay are urinary tract infections, and most of these infections are due to urinary catheters. The cost of treating each infection that causes symptoms is estimated to be at least $500.

The press release...

(hat tip: Gizmodo)

More at the New York Times...

The abstract...