How fast does a blue whale's heart beat?

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or the first time, researchers have managed to record the heart rate of the largest animal that has ever lived on planet Earth — the blue whale.

Share on PinterestResearchers have recorded the heart rate of the world's largest animal.

The blue whale, also known as a sulfur-bottom whale, or by its Latin name, Balaenoptera musculus, is the largest animal known to have lived, with an average weight of 150 tons and a maximum length of 30 meters (m).

A host of mind-boggling figures characterize this colossal animal: Calves are about 8-m long and can weigh up to 90 kilograms (kg), an adult whale has about 100 long grooves on its throat and chest, and only its heart can weigh up to 700 kg — but how fast does this huge vital organ beat?

Understanding physiological parameters, such as this mammal's heartbeat, enable researchers to understand better its evolution, as well as better manage and preserve the species, which some list as endangered.

To find out how fast such a large heart can beat, researchers from Stanford University in California set out to place electrocardiogram sensors on a blue whale in Monterey Bay.

Jeremy Goldbogen, who is an assistant professor of biology in the School of Humanities Sciences at Stanford, is the lead author of the paper that details the exploits of the research team. The scientists collaborated with Paul Ponganis, from the Scripps Institution of Oceanography.

Goldbogen and team published their findings in Proceedings of the National Academy of Sciences.

Placing electronic sensors on a blue whale

The scientists had previously measured the heart rates of emperor penguins using a tag full of sensors, and they then decided to try out the system in whales.

The team trialed the sensor tag in small, captive whales, and it succeeded. However, applying the tag to a blue whale in the wild was a different feat altogether that entailed various other challenges.

Firstly, people have trained captive whales to flip their bellies up, which allows for easier access. Secondly, the grooves on the blue whale's underside enable the large mammal to expand a great deal when feeding, thus making it easy for the tag to detach.

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"I honestly thought it was a long shot because we had to get so many things right — finding a blue whale, getting the tag in just the right location on the whale, good contact with the whale's skin and, of course, making sure the tag is working and recording data," Goldbogen explains.

"We had to put these tags out without really knowing whether or not they were going to work," says study co-author David Cade, who also placed the tag on the whale. "The only way to do it was to try it. So we did our best."

Cade managed to stick the tag from the first try, and four suction cups secured the electronic tag near the mammal's left flipper, where it recorded its heart rate.

Blue whale's heart performs at extremes

Once the researchers had analyzed the data, it revealed intriguing insights. When diving, the whale's heart slowed to 4–8 beats per minute and a minimum of two beats per minute.

When the whale was at the bottom of the ocean feeding, that heartbeat raised 2.5 times more than the minimum, and then gradually slowed again.

When it rose back to the surface and breathed in oxygen, the whale increased its heart rate to 25–37 beats per minute — a rate that is "near the estimated maximum heart rate possible," as the authors write in their paper.

Overall, the whale's highest heart rate was near the extreme, and the low rate was 30–50 times lower than that which the researchers had predicted.

"Animals that are operating at physiological extremes can help us understand biological limits to size," says Goldbogen.

"They may also be particularly susceptible to changes in their environment that could affect their food supply. Therefore, these studies may have important implications for the conservation and management of endangered species like blue whales."

Jeremy Goldbogen

The researchers think that the extreme limits near which a blue whale's heart operates may explain why there has never been another animal as large as this mammal — a heart would not be able to sustain the physiological needs of a larger body.

Source: MedicalNewsToday

What are the best home remedies for fever?

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ever occurs when a person's body temperature rises above the normal range. Although fevers tend to be harmless, they can cause great discomfort. A very high or persistent fever sometimes requires medical attention, though most fevers only require treatment with home remedies.

Infection is the most common cause of fever. In fact, developing a fever is the body's way of helping fight off the infection.

Some other causes include inflammatory conditions, certain cancers, and reactions to drugs or vaccines.

However, there are many ways to treat a fever at home. In this article, learn about some safe and effective fever home remedies for people of all ages.

Symptoms of fever

Share on PinterestA person should drink lots of fluids when they have a fever.

The average body temperature is around 98.6°F (37°C). However, body temperature fluctuates naturally throughout the day, especially with physical activity.

A low grade fever occurs when a person's body temperature reaches 100–102°F (37.8 to 39°C). A high grade fever occurs when a person's body temperature exceeds 104°F (40°C).

Aside from a higher body temperature, a person with a fever may also experience:

• sweating
• chills
• headache
• muscle aches
• loss of appetite
• fatigue
• lethargy

Very high fevers can sometimes cause seizures. These are called "febrile seizures." They are most common in children between 6 months and 5 years of age.

Symptoms of a febrile seizure include:

• twitching
• eye rolling
• stiffness in the arms or legs
• convulsions
• loss of consciousness

Febrile seizures tend to last a few minutes and do not usually cause any serious health problems. However, a child who has had a febrile seizure is more likely to have them again in future.

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Home remedies for adults

There are several things an adult can do to feel more comfortable when they have a fever. These include:

Drinking lots of fluids

During a fever, the body needs to use more water to compensate for its elevated temperature. This can lead to dehydration.

Drinking water or an electrolyte replacement drink can help rehydrate the body.

Resting

Fighting an infection takes a lot of energy. People should rest as much as possible to help the body recover.

Taking a tepid bath

Many people consider taking a cold bath when they have a fever. However, doing so can cause shivering, which will increase body temperature even more.

Instead, people can take a lukewarm or tepid bath to help the body cool off. A bath can also help soothe tired muscles.

Using over-the-counter medications

Medications are not usually necessary to treat a fever. However, some over-the-counter (OTC) medications can help reduce a fever and make a person feel more comfortable. These medications include:

• ibuprofen
• acetaminophen
• naproxen

Dressing lightly

Having a fever can cause a person to feel hot one minute and cold the next. Wearing too many layers can trap heat against the body, raising body temperature further.

People should wear few layers and add more if they start to feel cold.

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Home remedies for children and infants

The treatments for fever in children are very similar to those for adults. However, there are a few subtle differences.

For example, to treat a fever, children and infants should try:

Drinking plenty of fluids

Like adults, children with a fever also need plenty of fluids. However, it can be difficult to get young children to drink extra water.

Some more appealing alternatives include:

• warm chicken broth
• popsicles
• flavored jello
• diluted fruit juice

Resting

Children may feel better after taking OTC medications. As a result, they may feel more energetic and playful.

However, it is important to ensure that children rest until the fever or illness has passed.

If a child cannot sleep or relax, parents and caregivers can try reading them a story or playing them some gentle music.

Taking warm baths

Children are unlikely to appreciate bathing when they are sick. An alternative option is to place a warm washcloth on the child's forehead to help soothe the fever.

People should never apply rubbing alcohol to a child's skin in an attempt to soothe a fever. Alcohol can be dangerous when absorbed into the skin.

Taking OTC medications

As with adults, medication is not usually necessary for a child with fever. However, taking OTC medications can help reduce a fever and make a child feel more comfortable.

One drug that is suitable for children of most ages is acetaminophen. It is available under the brand name Tylenol.

Tylenol's manufacturers state that it is suitable for use even in very young infants. However, the Food and Drug Administration (FDA) do not supply dosage instructions for acetaminophen in children under 2 years of age.

People who wish to treat a young infant should ask their doctor's or pharmacist's advice on appropriate dosages.

Some medications are not suitable for children under certain ages. These include aspirin, which is not suitable for people under 16 years of age, and ibuprofen, which is not suitable for children under 3 months of age or those who weigh under 5 kilograms.

Ibuprofen is also not suitable for children with asthma.

When to see a doctor

People should be sure to see a doctor if they or their child experience a very high or persistent fever that does not respond to medication.

It is also important to seek medical attention if the fever is accompanied by any of the following symptoms:

• stiffness or pain in the neck
• sensitivity to light
• rash
• dehydration
• seizure

These symptoms could indicate a more serious infection, such as meningitis.

The threshold for seeking medical treatment is typically lower for children and infants than it is for adults. In general, people should seek medical treatment for a child who:

• is under 3 months old and has a fever of 100.4°F (38°C) or higher
• is 3–6 months old and has a temperature of 102.2°F (39°C) or higher
• has a fever that has lasted for longer than 5 days
• has other signs of illness, such as a rash
• has symptoms of dehydration, such as sunken eyes, a lack of tears when crying, or nappies that are not very wet
• is not eating and seems generally unwell

Summary

Fever is a common symptom of infection and inflammation. In most cases, a person can help soothe a fever at home.

A fever does not usually require medical treatment. However, taking OTC medications can lower a person's body temperature and help them feel more comfortable.

It is important to remember that some medications are not suitable for children under certain ages. Always check appropriate treatments and dosages with a doctor or pharmacist before administering them to a child or infant.

A person should see a doctor if they or their child experience a high or persistent fever that does not respond to medication. A fever that is accompanied by more serious signs of illness also requires medical attention.

• Complementary Medicine / Alternative Medicine
• Flu / Cold / SARS
• Infectious Diseases / Bacteria / Viruses
• Pediatrics / Children's Health

 9 sourcescollapsed

Medically reviewed by Kevin Martinez, M.D. on November 5, 2019 New — Written by Nicole Galan

Source: MedicalNewsToday

Should we worry about an eastern equine encephalitis outbreak?

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astern equine encephalitis (EEE) is a potentially deadly illness caused by a mosquito-borne virus. While infections in humans have been rare in the United States, an upsurge in reported cases this year has caused experts to wonder whether EEE could be the next Zika or West Nile.

Share on PinterestA rare virus has been infecting more and more people in the U.S. Experts are calling for a strategy to address a potential outbreak.

The EEE virus is carried by mosquitoes — through mosquito bites, it can be transmitted to equines, such as horses or zebras, and to humans.

This virus has been present in the U.S. for centuries, though it has rarely infected people.

However, if it does infect a person and the infection evolves into a severe form of the disease, EEE can be deadly.

Only a handful of these infections in humans had been reported throughout the U.S. each year for the past few years.

According to dataTrusted Source from the Centers for Disease Control and Prevention (CDC), last year there were six reported cases of EEE and five in 2017.

Until this year, the highest annual number of EEE cases in the country over the last decade had been 15, in 2012.

But as of November, this year has seen an upsurge in EEE cases in humans, including fatalities due to the illness. The CDC reportTrusted Source that there have been "36 confirmed cases of [EEE] virus disease [...] this year, including 14 deaths."

This situation has made some specialists wonder whether the EEE virus may not become the next threat to public health, much like the Zika or West Nile viruses.

'A new era' for mosquito-borne viruses?

Recently, experts from the National Institute of Allergy and Infectious Diseases (NIAID) published a commentary in The New England Journal of Medicine describing the EEE virus and how researchers plan to address this potential threat.

In the article — the first author of which is Dr. David Morens — the experts place EEE in the context of recent mosquito-borne virus (arbovirus) outbreaks worldwide.

"In recent years, the Americas have witnessed a steady stream of other emerging or reemerging arboviruses, such as dengue, West Nile, chikungunya, Zika, and Powassan, as well as increasing numbers of travel-related cases of various other arboviral infections," they write, warning that:

"This year's EEE outbreaks may thus be a harbinger of a new era of arboviral emergences."

Part of what makes the EEE virus potentially dangerous for humans is that its symptoms are sometimes indistinguishable from those of other viral infections. Some individuals report no symptoms at all in the initial stages of infection.

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The EEE virus takes 3–10 days to incubate inside a human host, and its — nonspecific — symptoms include fever, malaise, intense headaches, muscle aches, nausea, and vomiting.

Moreover, the specialists explain, EEE infections are difficult to diagnose with tests, as it is tricky to isolate the virus in samples of blood or spinal fluid. Yet, if neurologic symptoms of EEE do appear, these will be visible within approximately 5 days of infection.

And these, too, may be initially indistinguishable from the symptoms of viral meningitisTrusted Source.

"However, [after this period,] rapid clinical progression ensues," the experts write. "By the time definitive serologic diagnosis is possible, within a week after infection, neurologic damage may already have occurred."

"An estimated 96% of people infected with EEE [virus] remain asymptomatic; however, of those who have symptoms, 33% or more die, and most of the rest sustain permanent, often severe, neurologic damage," the specialists report.

Worrying lack of a prevention strategy

So what can we do in the event of an EEE outbreak? So far, not much, according to Dr. Morens and colleagues. Currently, no known antiviral drugs are safe and effective in the treatment of this viral infection.

For the time being, people who become infected will receive no more than "supportive treatmentTrusted Source," according to the CDC.

Some researchers have experimented with fighting the virus using monoclonal antibodies — artificially created antibodies that can help boost the immune response to a given pathogen. However, though this approach has shown some promise, scientists have, at this point, only tested it in animals.

Moreover, the monoclonal antibody treatment only appears to be effective if the researchers administer it to the animals before they become infected with the EEE virus.

Dr. Morens and colleagues believe that finding a vaccine for EEE would be an effective method of prevention, and some research has already gone into this.

"However," they note, "there may not be strong incentives to proceed to advanced development and licensure because of the nature of the disease: Outbreaks are rare, brief, and focal, and they occur sporadically in unpredictable locations, making it difficult to identify an appropriate target population for vaccination."

This is why the NIAID specialists are calling for a nationwide strategy for preventing an EEE outbreak before it gets the chance to become a reality.

"In the absence of vaccines or specific treatments, state and local health departments can provide early warning of imminent human infections by surveilling equids, birds, and mosquitoes," the team advises. Yet, "Even these blunt prevention tools are continuously threatened by underfunding of public health efforts."

"Sadly, the [U.S.'] ability to control arboviral diseases is little better in 2019 than it was more than a century ago," Dr. Morens and colleagues warn.

"Though the best way to respond to these threats is not entirely clear, to ignore them completely and do nothing would be irresponsible," the specialists conclude.

Source: MedicalNewsToday