City apartments or jungle huts? By their microbes you shall know them

By Associated Press, adapted by Newsela staff

02.24.16

WASHINGTON, D.C. — Whether it is a jungle hut or a high-rise apartment, your home is covered in bacteria. That is not always a bad thing. However, new research from the Amazon rain forest suggests city dwellers might want to open a window.

Learning About Microbes

Scientists traveled through South America, from remote villages in Peru to a large Brazilian city, to track one of the unseen effects of urbanization. Over time, more and more people have moved to urban areas like cities. Many things change as new buildings arise and more people live in a small area of land. This study focused on how urbanization affects the diversity of bacteria inside people's homes.

The study is a small first step in a larger quest to understand how different environmental bugs help shape what's called our microbiome. Microbiomes are the collections of bacteria and other tiny microbes that live inside our bodies. These trillions of bacteria share our bodies and play a critical role in our health.

"Very little is known about the microbes of the built environment," according to microbiologist Maria Gloria Dominguez-Bello. She is a professor at New York University, and led the study in South America.

The Walls Have Germs

Her team found that as people in the Amazon rain forest come to live in larger villages and cities the kinds of bacteria in their homes change. They lose the bugs mostly found in nature and pick up those that typically live on people.

In fact, in city dwellings, the researchers could tell just by the bacteria on the walls that "this is a kitchen or this is a bathroom or this is a living room. That's amazing," Dominguez-Bello said.

As she puts it, "the walls talk."

Everyone carries a customized set of bacteria on the skin, in the nose and in the gut. This bacteria starts accumulating at birth and helps with such things as digestion and the immune system, which fights off colds and disease. What influences the balance of good bugs and bad varies depending on such things as your diet, how you were born, and what antibiotic medicines you take. Environmental exposures play a role, too.

One Theory Of Allergies

For example, one theory suggests asthma and allergies are on the rise in Western populations because kids get less contact with bugs that were once common in their surroundings. This theory may be one reason why children who grow up on farms or around animals tend to have fewer of those immune-related illnesses.

Increasingly, scientists also are investigating where we spend a lot of time, especially our homes. To track the effects of urbanization, Dominguez-Bello's team studied the bacterial communities of 10 houses and their inhabitants from four different locations. Three of these were in Peru: a village of hunter-gatherers, a slightly more modern rural village and the medium-sized city of Iquitos. The fourth location was Manaus, a larger city in Brazil.

These locations gave the scientists the opportunity to compare similar people living in four different states of urbanization. Peru and Brazil are neighboring countries in South America. Each includes large sections of the Amazon rain forest. The people living in the two small villages are relatively similar to those living in Iquitos (population about 150,000) and Manaus (population about 2,000,000).

Bad Germs: Gone With The Wind?

Housing styles help tell the story, said study co-author Humberto Cavallin, an architect at the University of Puerto Rico. Large families shared open-air jungle huts with no outside walls. Homes in the rural villages had indoor walls but they did not reach the roof. City homes were larger with standard rooms and smaller families.

Despite having fewer people living in them, it was the city dwellings that had the most human bacteria living on their walls and floors, the researchers reported. In Manaus, bacteria normally found in the mouth and in the gut were the most important in telling rooms apart. The more crowded jungle and village homes were filled with bacteria commonly more found in soil and water than with human microbes.

The walls of city homes were acting as traps and retaining the bacteria that people shed. This was especially true when compared with the village homes that allowed air to circulate more freely, the team reported. Dominguez-Bello was so struck by the findings that she insisted the windows in her New York office be unsealed so she could open them.

A Balancing Act

She next will compare the microbiomes of the residents with their homes. However, she did acknowledge that there is a balancing act to this. While jungle and village homes may allow for more air to move within them, these have their own set of problems. For example, many of these homes do not have screens to keep out disease-carrying mosquitoes.

Still, the findings reflect research in U.S. homes and hospitals about the role of ventilation, said Jack Gilbert of the University of Chicago. He is a microbiologist who was not involved in the study. His own housing study was able to match which family lived where by the bacteria they shed inside.

He said that when it comes to studying microbiomes and bacteria, "our modern homes are set up perfectly."

Questions:

1. How did Maria Gloria Dominguez-Bello make her discovery about bacteria?

2. According to the study, what is the connection between urbanization and bacteria?

3. Why did village homes have less human bacteria than city homes?

4. Microbiomes are the collections of bacteria and other tiny microbes that live inside our bodies. These trillions of bacteria share our bodies and play a critical role in our health.

Which word would BEST replace "critical" in this sentence without changing its meaning?

A. minor

B. important

C. negative

D. mysterious

5. The walls of city homes were acting as traps and retaining the bacteria that people shed.

What is the BEST definition of "retaining" as used above?

A. to clean something

B. to harm something

C. to transform something

D. to hold on to something

6. Based on your understanding, define the word "antibiotic".

PRO/CON: The world's getting warmer, can nuclear power help us?

By Tribune News Service, adapted by Newsela staff
02.05.16

PRO: Using more nuclear energy will stop greenhouse gases

Nuclear power plants produce energy by splitting apart the nucleus, or center, of atoms. When the nucleus is split, heat is released. That newly released energy is then used to produce electricity. In turn, that electricity is sent through a grid to light our homes and power our computers. 

Nuclear power is only one of many ways of producing electricity. However, it is superior to any other method for one important reason. It is the best way to produce carbon-free electric power. 

Carbon is in carbon dioxide and other gases. It is released or emitted when fuels like coal, gas or oil are burned. People burn these fuels to power cars and all sorts of machinery. 

Carbon-containing gases are the main cause of the so-called greenhouse effect. Once they are released through the burning of fuels, they remain in the atmosphere and trap heat, just as heat is trapped in a greenhouse. Over time, this has caused average global temperatures to rise. 

A Valuable Tool

The global increase in average temperature is known as climate change or global warming. It is putting the planet at risk. Polar ice caps are starting to melt, thereby causing ocean levels to rise. Increasingly, coastlines and island nations are being submerged. In other parts of the world, droughts are becoming common as lakes and rivers dry up.

The world is starting to come together to try to limit climate change. Clearly, a carbon-free source of energy like nuclear power is a valuable tool in that effort.

Nuclear power now accounts for more than 60 percent of the United States' zero-carbon electricity. It is playing an essential part in the battle to reduce greenhouse gas emissions.

Wind power and solar power can also produce energy without releasing carbon. However, they are not constant. To work, the sun has to be out, or the wind has to be blowing.

Nuclear power plants run 24 hours a day, seven days a week. They are the only constant source of power that does not emit greenhouse gases.

An Excellent Safety Record

Many claim nuclear power is dangerous. Nuclear power plants produce radiation, which can be a dangerous form of energy. Even a small amount can cause severe damage to living things. Nuclear plants are built to keep radiation from leaking out, but many people worry such leaking will happen anyway.

Actually, there is no reason for concern. The nuclear power industry has an excellent safety record. 

The first commercial nuclear reactor began producing electricity more than 50 years ago. In all that time, there has not been a single death or injury from a radiation-related nuclear power plant accident in the United States. 

Many other countries also successfully rely on nuclear power. In France, nuclear power supplies 75 percent of the electricity, with enough to spare to provide almost a quarter of the electricity in Europe. 

The picture is very different in China, the world’s biggest carbon polluter. There, nuclear energy provides only 2 percent of the power. Coal remains China’s main energy source, and its use is increasing not only in China but throughout Asia.

Last month, representatives of most of the world's nations met in Paris, France, to discuss the climate crisis. The agreement they signed was far-reaching. It set a goal of bringing carbon emissions down to zero by the second half of this century.

Meeting that goal might seem impossible. However, France and Sweden show that countries can change their energy use very quickly. Both have been able to greatly increase their use of carbon-fee nuclear power in a relatively short time.

Reducing The Need For Oil

If the world built nuclear reactors at the same rate as France and Sweden have, the effect would be enormous. In 25 to 34 years, all the electricity now produced though burning coal and natural gas could be produced by nuclear power.

During this period, electric vehicles powered by nuclear-generated electricity could dramatically reduce the need for oil. These changes would greatly lower global carbon emissions and would help prevent dangerous climate change.

Meeting the new climate control goals is a daunting challenge. The world’s population is expected to increase to more than 9 billion by 2040. As a result, global demand for electricity will nearly double.

Unless the use of nuclear power is greatly increased, it will be impossible to both meet future energy demand and prevent dangerous climate change. Nuclear power is the only way to achieve both those goals at the same time.

CON: Nuclear power is only part of the answer, we need more solar and wind energy

The 2015 Paris climate agreement sets a remarkable goal. It calls on all countries to greatly reduce their greenhouse gas emissions.

Most of these emissions come from the burning of fossil fuels like coal, oil and natural gas. The message could not be clearer: We need to change the way we generate and use energy, and do so quickly.

The United States set itself a modest goal. It has pledged to cut emissions by around a quarter by 2025. The country has already taken some steps to meet that goal, but much more is needed.

Perhaps the most realistic approach is to increase the use of both nuclear power and renewable energy. Renewable energy sources, also called renewables, include such things as wind power and solar power.

A Better Bet

China has been using this approach. It plans to double its nuclear power capacity, and has 24 new plants now under construction. However, it is also expanding its use of wind and solar power.

Should the United States do the same? Yes, but only in part. Currently, our 99 nuclear reactors only account for about 8 percent of the electricity the U.S. consumes. Most of the energy we use, about 81 percent, comes from fossil fuels.

Nuclear power will have an important part to play, but it is unlikely to replace much fossil fuel use. It is still too expensive and too risky.

A better bet is to expand the use of renewables, while also working to make our energy use less wasteful.

Globally, nuclear electricity production has been leveling off while wind and solar power are soaring. There are good reasons for this.

One is cost. The new nuclear plants now being built in the U.S. are expected to cost $8 billion to $9 billion each, possibly more. It is also very expensive to safely shut down plants, which eventually becomes necessary when they are too old.

These very high costs make it difficult for the private utilities that provide our electricity to increase nuclear power generation. They see more promise and lower costs in natural gas-powered plants or in turning to renewables.

Nuclear Waste, And A Disaster

The problem of radioactive waste is another big reason to avoid an increase in nuclear power. There is currently no acceptable way to dispose of the highly radioactive waste nuclear plants create. 

There is also always the chance of the kind of disaster that occurred in Fukushima, Japan. In 2011, an earthquake there caused radiation-contaminated water to leak out of a nuclear plant, poisoning the surrounding area. The U.S. public remains understandably concerned that such a disaster could happen here.

A better way is for the country to greatly increase its use of renewables. At the same time, we should try to use energy in a way that is less wasteful. A non-wasteful use of energy is known as energy efficiency.

There are many ways to cut down on wasteful energy loss. Among them are improved building design, and a greater use of trains and buses in place of cars. We should modernize our electrical grid, and design better lighting, heating and cooling systems.

The United States also should put more money into research on promising new types of energy.

The federal government has long favored nuclear power and fossil fuels. For the past 10 years, renewables and energy efficiency have begun to receive significant support. We should keep moving in that direction, and quickly.

Questions:

1. What are the advantages of using nuclear plant?

2. What are the disadvantages of using nuclear plant?

3. Which countries are currently using nuclear plant as their main power supply?

4. Define "renewables" and give a few examples.

5. In your opinion, should our country use nuclear power and why?

When a friend yawns, women feel urge to yawn too, study says

By Los Angeles Times, Adapted by Newsela staff

02.11.16

If a person yawns, some people will yawn back. Women do this more often than men. Scientists from Italy made this claim recently in a science magazine. They did tests to find out if people can catch the urge to yawn.  

A yawn is involuntary. A person does not mean to do it. It happens by opening the mouth, breathing in, expanding a tube that leads to the eardrums, and then exhaling. The whole event takes about six seconds. 

Catching yawns is an example of a social contagion. A social contagion is when information, ideas or behaviors are spread from person to person. It spreads almost like a cold does. A person who sees a friend yawn might also yawn, even if he or she is not tired. A person may also yawn if they hear, see, read about, or even think about yawning.

It Starts In Childhood

Scientists connect contagious yawning to empathy. When a person is empathic, they can sense other people’s feelings. They may even feel the way the other person does. Contagious yawning seems to start when children are 4 or 5 years old, about the same time children start to develop empathy. In old age it falls off, along with empathy.

Scientists looked at why contagious yawning is related to empathy. They say it uses the same neural network. A neural network is a system of cells that send messages to the brain, spine and nerves. Contagious yawning also happens more with friends and family than with strangers.

People are not the only ones who catch yawns from others. Chimpanzees, bonobos, dogs, wolves and other animals do also. Contagious yawning can even spread between animals and humans. Scientists have found that chimpanzees and dogs both catch human yawns.

Strangers Get No Reaction

Science also suggests that women have more empathy than men do. Scientists connect more empathy to more contagious yawning. They say that if women are more empathic than men, then they must catch more yawns, too.

To find out, the Italian scientists took a closer look. They observed people at work, eating dinner and at other places. Over five years, they recorded almost 1,500 cases of yawning. The scientists watched 92 pairs of people who passed a yawn at least three times.

They found no difference between men and women in ordinary yawning. However, women did catch yawns much more often than men did. Scientists also found that both men and women yawned when friends and family yawned. Neither one yawned very often when people that they did not know well yawned.  

Scientists say the fact that women have more empathy could affect more than just social yawning. It could make them better parents, better at communicating, and better at living in groups. Greater empathy may also allow women to have relationships that last longer.

Vocabulary:

a. empathy 

b. urge

b. contagion 

d. involuntary

- the communication of disease from one person to another by close contact (                     )

- the ability to understand and share the feelings of another           (                         )

- done without will or conscious control (                        )

- a strong desire or impulse (                         )

Questions:

1. What was the claim that the scientists from Italy made?

2. What is the process of a yawn?

3. What cause people to yawn?

4. Why women are more contagious to yawn?

5. In your opinion, how does a good sleep affect a person's daily routine?

Grade Level 5