Virtual reality for mice teaches scientists about navigation

A mouse is ready to enter a virtual-reality system where its brain can be imaged while it thinks it’s running through a maze.
A mouse is ready to enter a virtual-reality system where its brain can be imaged while it thinks it’s running through a maze.

 

Scientists can now observe the brains of lab animals in microscopic detail as the animals go about some action. A technique called two-photon imaging, in particular, allows neuroscientists to watch thousands of neurons working in concert to encode information.

The trouble is, two-photon imaging requires the animal’s head to stay fixed in place. That would seem to preclude watching the brain as the animal does anything of much interest.

One creative solution is virtual reality—a computer-generated environment experienced through a headset. A few years ago neuroscientists started designing tiny virtual-reality systems to fool mice into thinking they were navigating a maze when they were really running on the top of a large ball, their heads fixed in position.

Until now, however, mice didn’t run on the ball until they’d had weeks of training. Jeremy Freeman, working with colleague Nicholas Sofroniew and others at the HHMI Janelia Research Campus in Virginia, created a virtual maze the mice seem to understand right away: they navigate through virtual corridors without training. It’s designed to exploit the way mice navigate in nature, Freeman says. Instead of relying primarily on their eyes, mice rely heavily on their whiskers to feel their way through the world.

In the whisker-oriented virtual reality, the walls move to give the mouse the illusion that it is running down winding corridors, he says. But the whole time, the rodent’s head is stationary.

This approach doesn’t translate neatly to the human world. Mice rely heavily on their whiskers to get around, and the neural imaging requires genetically altering mice to produce fluorescent proteins. However, this mouse-sized VR could still shed plenty of light on autism and other conditions that affect decisions, learning and the senses.


Story Source:

The above post is reprinted from materials provided by MIT Technology Review. Note: Materials may be edited for content and length.

Death in Every Stride – Literary Review

IMG-20150817-WA0002

We sometimes come across situations that make us feel sick. There is the tightening of stomach and the possibility of throwing up. The thought that what transpires before us is in fact a dream, might also creep up in our minds. But to our horror, we would realize that what has happened has happened and cannot be changed. That is exactly the feeling that one gets while reading Death in Every Stride.

Krisanne is a young girl who gets married to Paul with great expectations. She meets the harsh realities of life in the guise of Paul and his erratic behaviour. How she leads her life with patience and doggedness is explained by Megha Agarwal in this short novel.

Try as one might, it is impossible to go into the ‘novel-reading mode’ after a couple of chapters. The ferocity of the words used to describe the protagonist’s husband makes the reader to reel under the punch of each word. In the process, the author has managed to bring out the varied emotions of Krisanne, the protagonist of the novel. The Hopeful Krisanne, dreaming of the joy of married life and yet wondering about the change that is to happen is a nice opening to the story. What perhaps makes one to look at this not as a story is the narrative technique used. The lack of additional information about the characters, the places and the story in general gives one the feeling of reading a personal diary. That is what makes this story so disturbing and real.

The thought of the possibility of many Krisannes suffering silently in this country makes the reader to pause in his/her reading spree and ponder. Paul has been portrayed as nothing short of a marauding monster – suspicious, inhumane and sickening in his sexual preference. The perseverance of Krisanne is evident throughout the story, reminding the readers of the many housewives across India holding fast to the tradition of marriage and bearing the atrocities of their husbands.

Megha Agarwal, the young author, has expressed the untold miseries of many a woman pan India in a way that few experienced and older women would be able to do. Be it the shifting emotions of Krisanne, her shock at her husband’s behaviour, the solace that Krisanne finds in Patricia, the submissive nature of Aarav and the scornful nature of Emily, Megha has wrought all carefully and presented them as a bundle of feelings for the readers. Authorspress has indeed come out with a book that almost every Indian can connect with because of the issues dealt with in the book.

However, there are some downsides to the book as well. If Megha Agarwal had only lengthened the stroke of her writings and increased the word count of the book by adding more details, Death in Every Stride’s stride would’ve turned into a gallop, garnering more interest. The reader as of now, completes reading the book almost as quick as he/she starts reading. Another big letdown of the book is its editing. Proper editing of the book could’ve transformed this book into a wonder beyond belief.

But what cannot be denied is the fact that Megha Agarwal has contributed to Indian Literature a book that talks for women, their plight, their perseverance and their ability to fight back. Megha is an author to look out for!

NASA shows off Pluto’s largest moon

pluto-moon-Horizon-mission
This composite of enhanced color images of Pluto (lower right) and Charon (upper left), was taken by NASA’s New Horizons spacecraft as it passed through the Pluto system on July 14, 2015. This image highlights the striking differences between Pluto and Charon. The color and brightness of both Pluto and Charon have been processed identically to allow direct comparison of their surface properties, and to highlight the similarity between Charon’s polar red terrain and Pluto’s equatorial red terrain. Pluto and Charon are shown with approximately correct relative sizes, but their true separation is not to scale. The image combines blue, red and infrared images taken by the spacecraft’s Ralph/Multispectral Visual Imaging Camera (MVIC). Credits: NASA/JHUAPL/SwRI

 

NASA’s New Horizons spacecraft has returned the best color and the highest resolution images yet of Pluto’s largest moon, Charon – and these pictures show a surprisingly complex and violent history.

At half the diameter of Pluto, Charon is the largest satellite relative to its planet in the solar system. Many New Horizons scientists expected Charon to be a monotonous, crater-battered world; instead, they’re finding a landscape covered with mountains, canyons, landslides, surface-color variations and more.

NASA has posted some new high-res enhanced color pictures of Pluto’s largest moon, Charon (shown above in the upper left corner). Other than a reddish polar region, the images also reveal a surprisingly detailed landscape with canyons, mountains and more. A video composite of images (embedded after the break) takes us flying over a canyon NASA says is four times as long as the Grand Canyon, and twice as deep. NASA says even better pictures are on the way, although with the spacecraft 3.1 billion miles away and still going, we’ll be waiting a year to get everything.

charon-neutral-bright
Charon in Enhanced Color NASA’s New Horizons captured this high-resolution enhanced color view of Charon just before closest approach on July 14, 2015. The image combines blue, red and infrared images taken by the spacecraft’s Ralph/Multispectral Visual Imaging Camera (MVIC); the colors are processed to best highlight the variation of surface properties across Charon. Charon’s color palette is not as diverse as Pluto’s; most striking is the reddish north (top) polar region, informally named Mordor Macula. Charon is 754 miles (1,214 kilometers) across; this image resolves details as small as 1.8 miles (2.9 kilometers). Credits: NASA/JHUAPL/SwRI

 

Making batteries with portabella mushrooms

Diagram showing how mushrooms are turned into a material for battery anodes. Credit: Image courtesy of University of California - Riverside
Diagram showing how mushrooms are turned into a material for battery anodes.
Credit: Image courtesy of University of California – Riverside

Can portabella stop cell phone batteries from degrading over time?

Researchers at the University of California, Riverside Bourns College of Engineering think so.

They have created a new type of lithium-ion battery anode using portabella mushrooms, which are inexpensive, environmentally friendly and easy to produce. The current industry standard for rechargeable lithium-ion battery anodes is synthetic graphite, which comes with a high cost of manufacturing because it requires tedious purification and preparation processes that are also harmful to the environment.

With the anticipated increase in batteries needed for electric vehicles and electronics, a cheaper and sustainable source to replace graphite is needed. Using biomass, a biological material from living or recently living organisms, as a replacement for graphite, has drawn recent attention because of its high carbon content, low cost and environmental friendliness.

UC Riverside engineers were drawn to using mushrooms as a form of biomass because past research has established they are highly porous, meaning they have a lot of small spaces for liquid or air to pass through. That porosity is important for batteries because it creates more space for the storage and transfer of energy, a critical component to improving battery performance.

In addition, the high potassium salt concentration in mushrooms allows for increased electrolyte-active material over time by activating more pores, gradually increasing its capacity.

A conventional anode allows lithium to fully access most of the material during the first few cycles and capacity fades from electrode damage occurs from that point on. The mushroom carbon anode technology could, with optimization, replace graphite anodes. It also provides a binderless and current-collector free approach to anode fabrication.

“With battery materials like this, future cell phones may see an increase in run time after many uses, rather than a decrease, due to apparent activation of blind pores within the carbon architectures as the cell charges and discharges over time,” said Brennan Campbell, a graduate student in the Materials Science and Engineering program at UC Riverside.

The research findings were outlined in a paper, “Bio-Derived, Binderless, Hierarchically Porous Carbon Anodes for Li-ion Batteries,” published in the journal Scientific Reports. It was authored by Cengiz Ozkan and Mihri Ozkan, both professors in the Bourns College of Engineering, and three of their current or former graduate students: Campbell, Robert Ionescu and Zachary Favors.

Nanocarbon architectures derived from biological materials such as mushrooms can be considered a green and sustainable alternative to graphite-based anodes, said Cengiz Ozkan, a professor of mechanical engineering and materials science and engineering.

The nano-ribbon-like architectures transform upon heat treatment into an interconnected porous network architecture which is important for battery electrodes because such architectures possess a very large surface area for the storage of energy, a critical component to improving battery performance.

One of the problems with conventional carbons, such as graphite, is that they are typically prepared with chemicals such as acids and activated by bases that are not environmentally friendly, said Mihri Ozkan, a professor of electrical and computer engineering. Therefore, the UC Riverside team is focused on naturally-derived carbons, such as the skin of the caps of portabella mushrooms, for making batteries.

It is expected that nearly 900,000 tons of natural raw graphite would be needed for anode fabrication for nearly six million electric vehicle forecast to be built by 2020. This requires that the graphite be treated with harsh chemicals, including hydrofluoric and sulfuric acids, a process that creates large quantities of hazardous waste. The European Union projects this process will be unsustainable in the future.

The Ozkan’s research is supported by the University of California, Riverside.

This paper involving mushrooms is published just over a year after the Ozkan’s labs developed a lithium-ion battery anode based on nanosilicon via beach sand as the natural raw material. Ozkan’s team is currently working on the development of pouch prototype batteries based on nanosilicon anodes.

The UCR Office of Technology Commercialization has filed patents for the inventions above.


Story Source:

The above post is reprinted from materials provided by University of California – Riverside. The original item was written by Sean Nealon. Note: Materials may be edited for content and length.


Journal Reference:

  1. Brennan Campbell, Robert Ionescu, Zachary Favors, Cengiz S. Ozkan, Mihrimah Ozkan. Bio-Derived, Binderless, Hierarchically Porous Carbon Anodes for Li-ion Batteries. Scientific Reports, 2015; 5: 14575 DOI: 10.1038/srep14575

Sleep may strengthen long-term memories in the immune system

The immune system "remembers" an encounter with a bacteria or virus by collecting fragments from the bug to create memory T cells, which last for months or years and help the body recognize a previous infection and quickly respond. Credit: © Sabphoto / Fotolia
The immune system “remembers” an encounter with a bacteria or virus by collecting fragments from the bug to create memory T cells, which last for months or years and help the body recognize a previous infection and quickly respond.
Credit: © Sabphoto / Fotolia

More than a century ago, scientists demonstrated that sleep supports the retention of memories of facts and events. Later studies have shown that slow-wave sleep, often referred to as deep sleep, is important for transforming fragile, recently formed memories into stable, long-term memories. Now, in an Opinion article published September 29 inTrends in Neurosciences, part of a special issue on Neuroimmunology, researchers propose that deep sleep may also strengthen immunological memories of previously encountered pathogens.

“While it has been known for a long time that sleep supports long-term memory formation in the psychological domain, the idea that long-term memory formation is a function of sleep effective in all organismic systems is in our view entirely new,” says senior author Jan Born of the University of Tuebingen. “We consider our approach toward a unifying concept of biological long-term memory formation, in which sleep plays a critical role, a new development in sleep research and memory research.”

The immune system “remembers” an encounter with a bacteria or virus by collecting fragments from the bug to create memory T cells, which last for months or years and help the body recognize a previous infection and quickly respond. These memory T cells appear to abstract “gist information” about the pathogens, as only T cells that store information about the tiniest fragments ever elicit a response. The selection of gist information allows memory T cells to detect new pathogens that are similar, but not identical, to previously encountered bacteria or viruses.

Studies in humans have shown that long-term increases in memory T cells are associated with deep slow-wave sleep on the nights after vaccination. Taken together, the findings support the view that slow-wave sleep contributes to the formation of long-term memories of abstract, generalized information, which leads to adaptive behavioral and immunological responses. The obvious implication is that sleep deprivation could put your body at risk.

“If we didn’t sleep, then the immune system might focus on the wrong parts of the pathogen,” Born says. “For example, many viruses can easily mutate some parts of their proteins to escape from immune responses. If too few antigen-recognizing cells [the cells that present the fragments to T cells] are available, then they might all be needed to fight off the pathogen. In addition to this, there is evidence that the hormones released during sleep benefit the crosstalk between antigen-presenting and antigen-recognizing cells, and some of these important hormones could be lacking without sleep.”

Born says that future research should examine what information is selected during sleep for storage in long-term memory, and how this selection is achieved. In the end, this research could have important clinical implications.

“In order to design effective vaccines against HIV, malaria, and tuberculosis, which are based on immunological memory, the correct memory model must be available,” Born says. “It is our hope that by comparing the concepts of neuronal and immunological memory, a model of immunological memory can be developed which integrates the available experimental data and serves as a helpful basis for vaccine development.”


Story Source:

The above post is reprinted from materials provided by Cell Press. Note: Materials may be edited for content and length.


Journal Reference:

  1. Westermann et al. System Consolidation during Sleep–A Common Principle Underlying Psychological and Immunological Memory Formation. Trends in Neurosciences, September 2015 DOI:10.1016/j.tins.2015.07.007

Liquid water flows on today’s Mars: NASA confirms evidence

Dark, narrow streaks on Martian slopes such as these at Hale Crater are inferred to be formed by seasonal flow of water on contemporary Mars. The streaks are roughly the length of a football field. Credit: NASA/JPL-Caltech/Univ. of Arizona
Dark, narrow streaks on Martian slopes such as these at Hale Crater are inferred to be formed by seasonal flow of water on contemporary Mars. The streaks are roughly the length of a football field.
Credit: NASA/JPL-Caltech/Univ. of Arizona

New findings from NASA’s Mars Reconnaissance Orbiter (MRO) provide the strongest evidence yet that liquid water flows intermittently on present-day Mars.

Using an imaging spectrometer on MRO, researchers detected signatures of hydrated minerals on slopes where mysterious streaks are seen on the Red Planet. These darkish streaks appear to ebb and flow over time. They darken and appear to flow down steep slopes during warm seasons, and then fade in cooler seasons. They appear in several locations on Mars when temperatures are above minus 10 degrees Fahrenheit (minus 23 Celsius), and disappear at colder times.

“Our quest on Mars has been to ‘follow the water,’ in our search for life in the universe, and now we have convincing science that validates what we’ve long suspected,” said John Grunsfeld, astronaut and associate administrator of NASA’s Science Mission Directorate in Washington. “This is a significant development, as it appears to confirm that water — albeit briny — is flowing today on the surface of Mars.”

These downhill flows, known as recurring slope lineae (RSL), often have been described as possibly related to liquid water. The new findings of hydrated salts on the slopes point to what that relationship may be to these dark features. The hydrated salts would lower the freezing point of a liquid brine, just as salt on roads here on Earth causes ice and snow to melt more rapidly. Scientists say it’s likely a shallow subsurface flow, with enough water wicking to the surface to explain the darkening.

“We found the hydrated salts only when the seasonal features were widest, which suggests that either the dark streaks themselves or a process that forms them is the source of the hydration. In either case, the detection of hydrated salts on these slopes means that water plays a vital role in the formation of these streaks,” said Lujendra Ojha of the Georgia Institute of Technology (Georgia Tech) in Atlanta, lead author of a report on these findings published Sept. 28 by Nature Geoscience.

Ojha first noticed these puzzling features as a University of Arizona undergraduate student in 2010, using images from the MRO’s High Resolution Imaging Science Experiment (HiRISE). HiRISE observations now have documented RSL at dozens of sites on Mars. The new study pairs HiRISE observations with mineral mapping by MRO’s Compact Reconnaissance Imaging Spectrometer for Mars (CRISM).

The spectrometer observations show signatures of hydrated salts at multiple RSL locations, but only when the dark features were relatively wide. When the researchers looked at the same locations and RSL weren’t as extensive, they detected no hydrated salt.

Ojha and his co-authors interpret the spectral signatures as caused by hydrated minerals called perchlorates. The hydrated salts most consistent with the chemical signatures are likely a mixture of magnesium perchlorate, magnesium chlorate and sodium perchlorate. Some perchlorates have been shown to keep liquids from freezing even when conditions are as cold as minus 94 degrees Fahrenheit (minus 70 Celsius). On Earth, naturally produced perchlorates are concentrated in deserts, and some types of perchlorates can be used as rocket propellant.

Perchlorates have previously been seen on Mars. NASA’s Phoenix lander and Curiosity rover both found them in the planet’s soil, and some scientists believe that the Viking missions in the 1970s measured signatures of these salts. However, this study of RSL detected perchlorates, now in hydrated form, in different areas than those explored by the landers. This also is the first time perchlorates have been identified from orbit.

MRO has been examining Mars since 2006 with its six science instruments.

“The ability of MRO to observe for multiple Mars years with a payload able to see the fine detail of these features has enabled findings such as these: first identifying the puzzling seasonal streaks and now making a big step towards explaining what they are,” said Rich Zurek, MRO project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California.

For Ojha, the new findings are more proof that the mysterious lines he first saw darkening Martian slopes five years ago are, indeed, present-day water.

“When most people talk about water on Mars, they’re usually talking about ancient water or frozen water,” he said. “Now we know there’s more to the story. This is the first spectral detection that unambiguously supports our liquid water-formation hypotheses for RSL.”

The discovery is the latest of many breakthroughs by NASA’s Mars missions.

“It took multiple spacecraft over several years to solve this mystery, and now we know there is liquid water on the surface of this cold, desert planet,” said Michael Meyer, lead scientist for NASA’s Mars Exploration Program at the agency’s headquarters in Washington. “It seems that the more we study Mars, the more we learn how life could be supported and where there are resources to support life in the future.”


Story Source:

The above post is reprinted from materials provided by NASA/Jet Propulsion Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. Lujendra Ojha, Mary Beth Wilhelm, Scott L. Murchie, Alfred S. McEwen, James J. Wray, Jennifer Hanley, Marion Massé & Matt Chojnacki. Spectral evidence for hydrated salts in recurring slope lineae on Mars AOP. Nature Geoscience, 2015; DOI: 10.1038/ngeo2546

Small-scale nuclear fusion may be a new energy source

[dropcap]Fusion energy [/dropcap]may soon be used in small-scale power stations. This means producing environmentally friendly heating and electricity at a low cost from fuel found in water. Both heating generators and generators for electricity could be developed within a few years, according to research that has primarily been conducted at the University of Gothenburg.

Nuclear fusion is a process whereby atomic nuclei melt together and release energy. Because of the low binding energy of the tiny atomic nuclei, energy can be released by combining two small nuclei with a heavier one. A collaboration between researchers at the University of Gothenburg and the University of Iceland has been to study a new type of nuclear fusion process. This produces almost no neutrons but instead fast, heavy electrons (muons), since it is based on nuclear reactions in ultra-dense heavy hydrogen (deuterium).

“This is a considerable advantage compared to other nuclear fusion processes which are under development at other research facilities, since the neutrons produced by such processes can cause dangerous flash burns,” says Leif Holmlid, Professor Emeritus at the University of Gothenburg.

No radiation The new fusion process can take place in relatively small laser-fired fusion reactors fueled by heavy hydrogen (deuterium). It has already been shown to produce more energy than that needed to start it. Heavy hydrogen is found in large quantities in ordinary water and is easy to extract. The dangerous handling of radioactive heavy hydrogen (tritium) which would most likely be needed for operating large-scale fusion reactors with a magnetic enclosure in the future is therefore unnecessary.

Rendering of an atom. Nuclear fusion is a process whereby atomic nuclei melt together and release energy. Credit: © Sergey Nivens / Fotolia
Rendering of an atom. Nuclear fusion is a process whereby atomic nuclei melt together and release energy.
Credit: © Sergey Nivens / Fotolia

 

” A considerable advantage of the fast heavy electrons produced by the new process is that these are charged and can therefore produce electrical energy instantly. The energy in the neutrons which accumulate in large quantities in other types of nuclear fusion is difficult to handle because the neutrons are not charged. These neutrons are high-energy and very damaging to living organisms, whereas the fast, heavy electrons are considerably less dangerous.”

Neutrons are difficult to slow down or stop and require reactor enclosures that are several meters thick. Muons — fast, heavy electrons — decay very quickly into ordinary electrons and similar particles.

Research shows that far smaller and simpler fusion reactors can be built. The next step is to create a generator that produces instant electrical energy.

The research done in this area has been supported by GU Ventures AB, the holding company linked to the University of Gothenburg. The results have recently been published in three international scientific journals.


Story Source:

The above post is reprinted from materials provided by University of Gothenburg. The original item was written by Carina Eliasson. Note: Materials may be edited for content and length.


Journal References:

  1. Leif Holmlid, Sveinn Olafsson. Spontaneous ejection of high-energy particles from ultra-dense deuterium D(0). International Journal of Hydrogen Energy, 2015; 40 (33): 10559 DOI: 10.1016/j.ijhydene.2015.06.116
  2. Leif Holmlid, Sveinn Olafsson. Muon detection studied by pulse-height energy analysis: Novel converter arrangements. Review of Scientific Instruments, 2015; 86 (8): 083306 DOI: 10.1063/1.4928109
  3. Leif Holmlid. Heat generation above break-even from laser-induced fusion in ultra-dense deuterium. AIP Advances, 2015; 5 (8): 087129 DOI: 10.1063/1.4928572

Feckless – Vocabwagon

Feckless

The meaning of the word feckless is to lack  strength of character or to be irresponsible.

The word feckless is a noun.

Examples

  1. Although everyone wanted Ruth to score high grades in SAT, her feckless behaviour brought down her scores.
  2. The inexperienced man being made the captain of the team was a feckless move by the board.

Android flat button (xml) Tutorial

What is flat design?

Flat design is a minimalistic design approach that emphasizes usability. It features clean, open space, crisp edges, bright colors and two-dimensional/flat illustrations.

Benefits of flat design

Bright, contrasting colors make illustrations and buttons pop from backgrounds, easily grab attention, and guide the user’s eye. The purpose of minimalistic imagery also contributes to flat design’s functional character.

Tutorial

First we need to choose two colors: for normal state and pressed state. Usually that’s the same colors with different type of depth. Pressed state color will also be used as for bottom line of flat button normal state.

Create colors.xml file inside values folder and define two colors there:

<resources>
    <color name="blue_pressed">@android:color/holo_blue_dark</color>
    <color name="blue_normal">@android:color/holo_blue_light</color>
</resources>

We used two standard android holo colors:

<!-- A dark Holo shade of blue -->
<color name="holo_blue_dark">#ff0099cc</color>
<!-- A light Holo shade of blue -->
<color name="holo_blue_light">#ff33b5e5</color>

 

Now we need to create dimen.xml file inside values folder and define two parameters:

<resources>
    <dimen name="corner_radius">4dp</dimen>
    <dimen name="layer_padding">3dp<<dimen>
</resources>

Corner radius indicate how rounded the corners of our button will be. See image below.say-hello-android-flat-button-1

 

Layer radius indicate distance between bottom and top layer of our button. See image below.say-hello-android-flat-button-2

 

Next step is to define shapes for button background. Create rect_pressed.xml file inside drawable folder. This will be our pressed state background and bottom layer for normal state.

<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
  <corners android:radius="@dimen/corner_radius" />
  <solid android:color="@color/blue_pressed" />
</shape>>

 

say-hello-android-flat-button-drawableFor normal state create rect_normal.xml file inside drawable folder. This drawable combines two layers, for bottom layer we used rect_pressed drawable and for top layer we defined new shape with little padding on the bottom (to make bottom layer visible) and new blue color.

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:drawable="@drawable/rect_pressed" />
 
  <item android:bottom="@dimen/layer_padding">
      <shape android:shape="rectangle">
          <corners android:radius="@dimen/corner_radius" />
          <solid android:color="@color/blue_normal" />
      </shape>
  </item>
</layer-list>

say-hello-android-flat-button-drawable-1

Last thing to do is to define selector for our button. Create flat_selector.xml file inside drawablefolder.

<selector xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:state_pressed="true" android:drawable="@drawable/rect_pressed"/>
  <item android:drawable="@drawable/rect_normal"/>
</selector>

That’s all, now simply define your button and set background to flat_selector.

<Button
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:background="@drawable/flat_selector"
      android:textColor="@android:color/white"
      android:text="Say Hello" />

Hope you enjoy this little article.

Feeling anxious? Check your orbitofrontal cortex, cultivate your optimism

Glass half full or half empty? What you see may depend in part on the size of your orbitofrontal cortex. Optimistic people also tend to be less anxious, research finds. Credit: Graphic by Julie McMahon
Glass half full or half empty? What you see may depend in part on the size of your orbitofrontal cortex. Optimistic people also tend to be less anxious, research finds.
Credit: Graphic by Julie McMahon

 

A new study links anxiety, a brain structure called the orbitofrontal cortex, and optimism, finding that healthy adults who have larger OFCs tend to be more optimistic and less anxious.

The new analysis, reported in the journal Social, Cognitive and Affective Neuroscience, offers the first evidence that optimism plays a mediating role in the relationship between the size of the OFC and anxiety.

Anxiety disorders afflict roughly 44 million people in the U.S. These disorders disrupt lives and cost an estimated $42 billion to $47 billion annually, scientists report.

The orbitofrontal cortex, a brain region located just behind the eyes, is known to play a role in anxiety. The OFC integrates intellectual and emotional information and is essential to behavioral regulation. Previous studies have found links between the size of a person’s OFC and his or her susceptibility to anxiety. For example, in a well-known study of young adults whose brains were imaged before and after the colossal 2011 earthquake and tsunami in Japan, researchers discovered that the OFC actually shrank in some study subjects within four months of the disaster. Those with more OFC shrinkage were likely to also be diagnosed with post-traumatic stress disorder, the researchers found.

Other studies have shown that more optimistic people tend to be less anxious, and that optimistic thoughts increase OFC activity.

The team on the new study hypothesized that a larger OFC might act as a buffer against anxiety in part by boosting optimism.

Most studies of anxiety focus on those who have been diagnosed with anxiety disorders, said University of Illinois researcher Sanda Dolcos, who led the research with graduate student Yifan Hu and psychology professor Florin Dolcos. “We wanted to go in the opposite direction,” she said. “If there can be shrinkage of the orbitofrontal cortex and that shrinkage is associated with anxiety disorders, what does it mean in healthy populations that have larger OFCs? Could that have a protective role?”

The researchers also wanted to know whether optimism was part of the mechanism linking larger OFC brain volumes to lesser anxiety.

The team collected MRIs of 61 healthy young adults and analyzed the structure of a number of regions in their brains, including the OFC. The researchers calculated the volume of gray matter in each brain region relative to the overall volume of the brain. The study subjects also completed tests that assessed their optimism and anxiety, depression symptoms, and positive (enthusiastic, interested) and negative (irritable, upset) affect.

A statistical analysis and modeling revealed that a thicker orbitofrontal cortex on the left side of the brain corresponded to higher optimism and less anxiety. The model also suggested that optimism played a mediating role in reducing anxiety in those with larger OFCs. Further analyses ruled out the role of other positive traits in reducing anxiety, and no other brain structures appeared to be involved in reducing anxiety by boosting optimism.

“You can say, ‘OK, there is a relationship between the orbitofrontal cortex and anxiety. What do I do to reduce anxiety?'” Sanda Dolcos said. “And our model is saying, this is working partially through optimism. So optimism is one of the factors that can be targeted.”

“Optimism has been investigated in social psychology for years. But somehow only recently did we start to look at functional and structural associations of this trait in the brain,” Hu said. “We wanted to know: If we are consistently optimistic about life, would that leave a mark in the brain?”

Florin Dolcos said future studies should test whether optimism can be increased and anxiety reduced by training people in tasks that engage the orbitofrontal cortex, or by finding ways to boost optimism directly.

“If you can train people’s responses, the theory is that over longer periods, their ability to control their responses on a moment-by-moment basis will eventually be embedded in their brain structure,” he said.


Story Source:

The above post is reprinted from materials provided by University of Illinois at Urbana-Champaign. The original item was written by Diana Yates. Note: Materials may be edited for content and length.


Journal References:

  1. Sanda Dolcos et al. Optimism and the Brain: Trait Optimism Mediates the Protective Role of the Orbitofrontal Cortex Gray Matter Volume against Anxiety. Social, Cognitive and Affective Neuroscience, September 2015 DOI: 10.1093/scan/nsv106
  2. A Sekiguchi, M Sugiura, Y Taki, Y Kotozaki, R Nouchi, H Takeuchi, T Araki, S Hanawa, S Nakagawa, C M Miyauchi, A Sakuma, R Kawashima. Brain structural changes as vulnerability factors and acquired signs of post-earthquake stress. Molecular Psychiatry, 2012; 18 (5): 618 DOI: 10.1038/mp.2012.51