Enuresis: What is bed wetting and how to control it?

Bed-wetting is normal and very com­mon among preschoolers, affecting 40 percent of children at age three. It is much less frequent in school-age children, occurring in 20 percent of five-year-olds, 10 percent of six-year-olds, and 3 percent of twelve-year-olds. Thus, during the middle years of childhood, parents may want to seek the assistance of their pedia­trician in an effort to reduce or eliminate bed-wetting, or enuresis, says a document of the American Academy of Pediatrics.

 

For a child to remain dry at night, her brain must keep a full bladder from emptying. Or a signal from the bladder must be strong enough to awaken the child from sleep and send her to the toilet. It is a com­plex neurodevelopmental process for the bladder to send the signal, for the brain to receive it, and for the child to respond by awakening and using the toilet.

 

There are many theories about the causes of bed-wetting. Many parents fear that a disease is causing the difficulty. How­ever, no more than 1 percent of cases actu­ally are related to physical diseases such as kidney or bladder infections, diabetes, or congenital defects of the urinary sys­tem. In these instances the child also generally experiences changes in the fre­quency and volume of daytime urination, or discomfort associated with urination.

 

In the majority of cases of bed-wetting, however, the cause is simply delayed maturation of bladder control mecha­nisms, often related to the child's geneticbackground. These children are physically and psychologically normal.

 

Emotional problems are an occasional cause of enuresis. For instance, a child who is overwhelmed with stress may develop enuresis, even though she had formerly been dry at night. Children who are being sexually or physically abused may also de­velop enuresis.

 

Most school-age children who wet their beds have primary enuresis, meaning they have had this condition since birth and have never developed nighttime bladder control. These children often have a family history of this problem, and they seem to have inherited the tendency for developing nighttime bladder control at a later-than-average age. In most cases the child becomes dry at about the same age that her parent(s) did. Interestingly, if one identical twin has a bed-wetting problem, her twin also will; however, fraternal twins (non-identical twins with different genetic make­ups) often do not both have this problem.

 

Sometimes parents pressure a child to develop nighttime bladder control before her body is ready to do so. These parents may erroneously view bed-wetting as a will­ful and oppositional act of their child, and thus they may try coercing her to change her behavior. The youngster may become discouraged and depressed when she con­tinues to wet the bed. As hard as she may try, the enuresis is beyond her voluntary control, and she may become frustrated  and despondent because of her lack of suc­cess.

 

For the child who wets the bed, parents need to remain supportive and encouraging. They should be sensitive to the child's embarrassment or discomfort over this problem. The youngster may resist spend­ing the night at a friend's house or going to summer camp and may be uncomfortable about her friends' finding out about this condition. Parents can reassure the child that it is not her fault, and the problem willget better in time.

Stars outside the solar system too have planets, says Nasa

FIRST PLANETS FOUND AROUND SUN-LIKE STARS IN A CLUSTER

NASA-funded astronomers have, for the first time,
spotted planets orbiting sun-like stars in a crowded cluster of
stars. The findings offer the best evidence yet planets can sprout up
in dense stellar environments. Although the newfound planets are not
habitable, their skies would be starrier than what we see from Earth.


The starry-skied planets are two so-called hot Jupiters, which are
massive, gaseous orbs that are boiling hot because they orbit tightly
around their parent stars. Each hot Jupiter circles a different
sun-like star in the Beehive Cluster, also called the Praesepe, a
collection of roughly 1,000 stars that appear to be swarming around a
common center, says a Nasa statement.

The Beehive is an open cluster, or a grouping of stars born at about
the same time and out of the same giant cloud of material. As such,
the stars share a similar chemical composition. Unlike the majority
of stars, which spread out shortly after birth, these young stars
remain loosely bound together by mutual gravitational attraction.

"We are detecting more and more planets that can thrive in diverse and
extreme environments like these nearby clusters," said Mario R.
Perez, the NASA astrophysics program scientist in the Origins of
Solar Systems Program. "Our galaxy contains more than 1,000 of these
open clusters, which potentially can present the physical conditions
for harboring many more of these giant planets."

The two new Beehive planets are called Pr0201b and Pr0211b. The star's
name followed by a "b" is the standard naming convention for planets.


"These are the first 'b's' in the Beehive," said Sam Quinn, a graduate
student in astronomy at Georgia State University in Atlanta and the
lead author of the paper describing the results, which was published
in the Astrophysical Journal Letters.

Quinn and his team, in collaboration with David Latham at the
Harvard-Smithsonian Center for Astrophysics, discovered the planets
by using the 1.5-meter Tillinghast telescope at the Smithsonian
Astrophysical Observatory's Fred Lawrence Whipple Observatory in
Arizona to measure the slight gravitational wobble the orbiting
planets induce upon their host stars. Previous searches of clusters
had turned up two planets around massive stars but none had been
found around stars like our sun until now.

"This has been a big puzzle for planet hunters," Quinn said. "We know
that most stars form in clustered environments like the Orion nebula,
so unless this dense environment inhibits planet formation, at least
some sun-like stars in open clusters should have planets. Now, we
finally know they are indeed there."

The results also are of interest to theorists who are trying to
understand how hot Jupiters wind up so close to their stars. Most
theories contend these blistering worlds start out much cooler and
farther from their stars before migrating inward.

"The relatively young age of the Beehive cluster makes these planets
among the youngest known," said Russel White, the principal
investigator on the NASA Origins of Solar Systems grant that funded
this study. "And that's important because it sets a constraint on how
quickly giant planets migrate inward. And knowing how quickly they
migrate is the first step to figuring out how they migrate."

The research team suspects planets were turned up in the Beehive
cluster because it is rich in metals. Stars in the Beehive have more
heavy elements such as iron than the sun has.

According to White, "Searches for planets around nearby stars suggest
that these metals act like a 'planet fertilizer,' leading to an
abundant crop of gas-giant planets. Our results suggest this may be
true in clusters as well."

Microbial life on the Mars? Nasa Mars rover Opportunity reveals geological mystery of the Red Planet

NASA MARS ROVER OPPORTUNITY REVEALS GEOLOGICAL MYSTERY

NASA's long-lived rover Opportunity has returned
an image of the Martian surface that is puzzling researchers.

Spherical objects concentrated at an outcrop Opportunity reached last
week differ in several ways from iron-rich spherules nicknamed
"blueberries" the rover found at its landing site in early 2004 and
at many other locations to date, says a NASA statement.

Opportunity is investigating an outcrop called Kirkwood in the Cape
York segment of the western rim of Endeavour Crater. The spheres
measure as much as one-eighth of an inch (3 millimeters) in diameter.
The analysis is still preliminary, but it indicates that these
spheres do not have the high iron content of Martian blueberries.

"This is one of the most extraordinary pictures from the whole
mission," said Opportunity's principal investigator, Steve Squyres of
Cornell University in Ithaca, N.Y. "Kirkwood is chock full of a dense
accumulation of these small spherical objects. Of course, we
immediately thought of the blueberries, but this is something
different. We never have seen such a dense accumulation of spherules
in a rock outcrop on Mars."

The Martian blueberries found elsewhere by Opportunity are concretions
formed by action of mineral-laden water inside rocks, evidence of a
wet environment on early Mars. Concretions result when minerals
precipitate out of water to become hard masses inside sedimentary
rocks. Many of the Kirkwood spheres are broken and eroded by the
wind. Where wind has partially etched them away, a concentric
structure is evident.

Opportunity used the microscopic imager on its arm to look closely at
Kirkwood. Researchers checked the spheres' composition by using an
instrument called the Alpha Particle X-Ray Spectrometer on
Opportunity's arm.

"They seem to be crunchy on the outside, and softer in the middle,"
Squyres said. "They are different in concentration. They are
different in structure. They are different in composition. They are
different in distribution. So, we have a wonderful geological puzzle
in front of us. We have multiple working hypotheses, and we have no
favorite hypothesis at this time. It's going to take a while to work
this out, so the thing to do now is keep an open mind and let the
rocks do the talking."

Just past Kirkwood lies another science target area for Opportunity.
The location is an extensive pale-toned outcrop in an area of Cape
York where observations from orbit have detected signs of clay
minerals. That may be the rover's next study site after Kirkwood.
Four years ago, Opportunity departed Victoria Crater, which it had
investigated for two years, to reach different types of geological
evidence at the rim of the much larger Endeavour Crater.

The rover's energy levels are favorable for the investigations. Spring
equinox comes this month to Mars' southern hemisphere, so the amount
of sunshine for solar power will continue increasing for months.

"The rover is in very good health considering its 8-1/2 years of hard
work on the surface of Mars," said Mars Exploration Rover Project
Manager John Callas of NASA's Jet Propulsion Laboratory in Pasadena,
Calif. "Energy production levels are comparable to what they were a
full Martian year ago, and we are looking forward to productive
spring and summer seasons of exploration."

NASA launched the Mars rovers Spirit and Opportunity in the summer of
2003, and both completed their three-month prime missions in April
2004. They continued bonus, extended missions for years. Spirit
finished communicating with Earth in March 2010. The rovers have made
important discoveries about wet environments on ancient Mars that may
have been favorable for supporting microbial life.

What makes the complete face and gives us our identity: Scientists say five genes help in the formation of a face

Five Genes Help Form a Face

by Elizabeth Pennisi 

Here's an advance that may have cops smiling from ear to ear: Researchers have now teased out five genes that help control the width of the human face. Though hundreds of genes involved in face shape remain to be identified, the findings represent an early step toward facial reconstruction with DNA, says a report published in the Science.

Crime labs see a bright future for forensic genomics; they are already moving toward predicting hair and eye colour based on genetic information. But the ultimate goal is to reconstruct the full visage of a criminal from his DNA, which might be found at a crime scene.

But the face is a very complex structure, requiring much genetic input to be put together. Eight years ago, Manfred Kayser, a geneticist at Erasmus MC in Rotterdam, the Netherlands, wondered whether it would even be possible to tease out which versions of a gene would lead to a broad nose or a wide forehead. If it were, he reasoned, then eventually a computer program could build a composite of a perpetrator's face based on DNA—much as a sketch artist today combines the recollections of eyewitnesses to help an investigation. "If you can get into the shape of the nose, the eyes, the lips, that can be of a lot of value," says Bruce Budowle, a geneticist at the University of North Texas Health Science Center in Fort Worth who was not involved in the work.

Before Kayser and his colleagues could start to identify those genes, they needed to break down the face into discrete, measurable features that could be assessed in each individual. Looking at MRI images, they picked out nine landmarks on the face. The distances between different pairs of landmarks in a given face were traits for the team to evaluate—for example, the spacing between the eyes or the distance from the tip of the nose to its base.

As part of the International Visible Trait Genetics Consortium, he and his colleagues examined the DNA of five groups of people to see whether any particular variants of a gene were associated with each trait. Each group contained between 545 and 2470 individuals. Three other groups of people were subsequently evaluated as well, as a way to independently test the genetic correlations derived from the first five groups.

Kayser and his colleagues report today in PLoS Genetics. The genes influenced traits such as the width of the face, the distance between the eyes, and how far the nose sticks out. One gene, called PAX3, had already been linked to the shape of the face in children, giving Kayser confidence that his approach to finding relevant genes worked. Other researchers had previously tied two of the other genes, one on chromosome 2 and one on chromosome 3, to facial problems such as a cleft lip or misformed jaws. The final two genes were newly connected to facial development, he notes. "That we were able to find these genes was a surprise," he adds.

On the downside, the work confirms what many had suspected. "There are no common variants with large effects," says Lavinia Paternoster, a geneticist at the University of Bristol in the United Kingdom, who plans to work with Kayser in the future on finding more facial genes. "It is likely that there are many hundreds or thousands of these variants," each having a small influence on the face, she says.

That many more genes are involved, each contributing a little bit toward building the face, means that "this is just the first step in a long journey," Budowle says. Kayser's team plans to hunt for other genes, by increasing the number of landmarks they evaluate and acquiring MRIs of more people. Finding genes with small effects requires that a lot of people be studied, Paternoster points out, and that could be hard to do because there aren't many studies where DNA was collected and MRIs were done.

Budowle is optimistic that within 2 to 5 years, some form of facial reconstruction with DNA will be possible. But that certainly is not possible now, Paternoster says: "The variability in this study only explains a very tiny proportion of the variability in face shape, and so cannot be used to predict the face shape."

What lies in the Red Planet Mars: Latest photos further deepen mystery of the Earth's neighbour

Mystery Spheres on Mars

NASA's long-lived rover Opportunity has returned an image of the Martian surface that is puzzling researchers.

Spherical objects concentrated at an outcrop called Kirkwood on the western rim of Endeavour Crater differ in several ways from iron-rich spherules nicknamed "blueberries" the rover found at its landing site in early 2004.

"This is one of the most extraordinary pictures from the whole mission," said Opportunity's principal investigator, Steve Squyres of Cornell University in Ithaca, N.Y. "Kirkwood is chock full of a dense accumulation of these small spherical objects. Of course, we immediately thought of the blueberries, but this is something different. We never have seen such a dense accumulation of spherules in a rock outcrop on Mars."

Using its Microscopic Imager, Opportunity photographed these small spherical objects on Sept. 6, 2012. The view covers an area about 2.4 inches across at an outcrop called "Kirkwood" on the western rim of Endeavour Crater.The spheres measure as much as one-eighth of an inch (3 millimeters) in diameter. The analysis is still preliminary, but it indicates that these spheres do not have the high iron content of Martian blueberries.

The Martian blueberries found elsewhere by Opportunity are concretions formed by action of mineral-laden water inside rocks, evidence of a wet environment on early Mars. Concretions result when minerals precipitate out of water to become hard masses inside sedimentary rocks. Many of the Kirkwood spheres are broken and eroded by the wind. Where wind has partially etched them away, a concentric structure is evident.

Opportunity used the microscopic imager on its arm to look closely at Kirkwood. Researchers checked the spheres' composition by using an instrument called the Alpha Particle X-Ray Spectrometer on Opportunity's arm.

"They seem to be crunchy on the outside, and softer in the middle," Squyres said. "They are different in concentration. They are different in structure. They are different in composition. They are different in distribution. So, we have a wonderful geological puzzle in front of us. We have multiple working hypotheses, and we have no favorite hypothesis at this time. It's going to take a while to work this out, so the thing to do now is keep an open mind and let the rocks do the talking."

Just past Kirkwood lies another science target area for Opportunity. The location is an extensive pale-toned outcrop in an area of Cape York where observations from orbit have detected signs of clay minerals. That may be the rover's next study site after Kirkwood. Four years ago, Opportunity departed Victoria Crater, which it had investigated for two years, to reach different types of geological evidence at the rim of the much larger Endeavour Crater.

The rover's energy levels are favorable for the investigations. Spring equinox comes this month to Mars' southern hemisphere, so the amount of sunshine for solar power will continue increasing for months.  Indeed, Opportunity is on the verge of completing the first Martian Marthon.

"The rover is in very good health considering its 8-1/2 years of hard work on the surface of Mars," said Mars Exploration Rover Project Manager John Callas of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Energy production levels are comparable to what they were a full Martian year ago, and we are looking forward to productive spring and summer seasons of exploration."

The dangers of nanoparticles: Even plants are affected by tiny nanoparticles as they disrupt the physiological functions

Metal Nanoparticles Hurt Soybean Growth

by Robert F. Service

Soybeans are the second largest crop harvested in the United States and a $30-billion-a-year industry. But soybean production could face a new long-term threat from large amounts of metallic nanoparticles in the environment, says a report in the journal Science.

A new study reveals that one type of these nano-sized materials, found in everything from cosmetics to electronic devices, can be absorbed by soybeans and move throughout their tissues, while another type of nanoparticle likely stunts their growth. The findings, the authors say, raise concerns about the impact of nanoparticles on a host of other crops.

Metal contamination has long been a concern in agriculture. The U.S. Environmental Protection Agency currently requires companies that discharge potentially toxic metals into wastewater to remove the metals before the water is sent to wastewater treatment plants. Half of the organic material collected from such treatment plants eventually ends up on farmers' fields as fertilizer. However, the presence of metal nanoparticles in wastewater is neither regulated nor monitored. And, within a decade, industry could be producing millions of metric tons of some metal nanoparticles per year, raising concerns about their accumulation in the environment.

Such concerns have already prompted some initial studies looking for possible biological impacts. In 2010, researchers led by Jorge Gardea-Torresdey, a chemist at the University of Texas, El Paso, reported inEnvironmental Science & Technology that when soybeans were grown hydroponically and exposed to high levels of zinc oxide and cerium oxide nanoparticles, those particles could accumulate in plant tissues, with cerium oxide triggering genetic damage in the plants' roots. Another study published online last month in Applied and Environmental Microbiology found that high concentrations of zinc oxide and titanium dioxide nanoparticles disrupt soil bacterial communities and interfere with the ability of rhizobia bacteria that associate with soybeans to use nitrogen from the air to produce fertilizer for the plant. This ability of soybeans to "fix" nitrogen has a major impact on agriculture. Whereas 97% of corn farmed in the United States requires fertilizer, only 18.5% of the 77 million acres of soybeans farmed in the United States each year are fertilized.

Still, it was unclear whether compounds present in the dirt would lock up nanoparticles or whether the nanoparticles would be "bioavailable," allowing plants to take them up. So for the new study, University of California, Santa Barbara, environmental microbiologist Patricia Holden, who led the Applied and Environmental Microbiology study, teamed up with Gardea-Torresdey as well as colleagues at four other institutions in the United States and South Korea to test the effect of metal nanoparticles on soybeans grown the old-fashioned way. They mixed zinc oxide and cerium oxide nanoparticles into separate batches of soil from an organic farm in California. Then they split these mixtures into several lots, each time adding a different amount of pristine soil to give the lots concentrations of metal nanoparticles that previous hydroponic studies had flagged as potentially having a biological impact. That gave them three different soil concentrations of each of the two nanoparticles. For the zinc oxide, the concentration was either 0.005, 0.1, or 0.5 grams per kilogram of soil. For cerium oxide, the concentration was either 0.1, 0.5, or 1 gram per kilogram. The team then tracked the amount of nanoparticles taken up by different tissues of the plant and the impact on their growth.

The researchers report their results online this week in the Proceedings of the National Academy of Sciences. Only plant roots and the root nodules that serve as nurseries for rhizobia absorbed cerium oxide nanoparticles. But at the mid- and high-exposure levels the plants were essentially unable to fix nitrogen. Holden says that in these cases the root nodules that normally house nitrogen-fixing bacteria were "were vacant of bacteria." But she cautions that although it appears that the cerium oxide nanoparticles are the culprit, the researchers can't yet be sure.

As for the zinc oxide, Holden's team found that these metal particles didn't seem to have any significant biological effect, though soybean tissues with high levels of the metal tended to hold less water. Still, zinc levels rose throughout the plants' tissues, even in the beans that would be used as food for humans and livestock. This high level of zinc doesn't necessarily pose a threat to people, Holden says, since the zinc levels were essentially on par with the amount of zinc recommended for people's diets in the United States. But she adds that she and her colleagues aren't sure if the zinc in soybeans is transformed into zinc ions, the form of the metal that is normally present in our bodies, or remains zinc oxide nanoparticles, which could have different biological effects.

"This is a pioneering study" that's beginning to tease out potential agricultural impacts of nanomaterials, says Andre Nel, a nanomaterials toxicologist at the University of California, Los Angeles. He is quick to add that it is unlikely that soybeans and other plants are currently exposed to nanoparticle concentrations as high as those used in the new study, but researchers aren't sure. "In the world of agricultural exposure levels, nobody knows what the nanomaterial concentration is."

"Is this an indication we should be worried about the food supply? I don't know," Holden says. The take-home message, she says, is that "there is a potential for nanomaterials to be bioavailable in soil and affect agriculture." Whether they will eventually accumulate in the high concentrations shown to have an impact here is unclear. However, she says, "it's important that the scientific community asks these questions in advance."