My Science School

The leading cause of maternal mortality in Europe at that time was puerperal fever – an infection, now known to be caused by the streptococcus bacterium, that killed postpartum women.

Prior to 1823, about 1 in 100 women died in childbirth at the Vienna Hospital. But after a policy change mandated that medical students and obstetricians perform autopsies in addition to their other duties, the mortality rate for new mothers suddenly jumped to 7.5%. What was going on?

Eventually, the Vienna Hospital opened a second obstetrics division, to be staffed entirely by midwives. The older, First Division, to which Semmelweis was assigned, was staffed only by physicians and medical students. Rather quickly it became apparent that the mortality rate in the first division was much higher than the second.

Semmelweis set out to investigate. He examined all the similarities and differences of the two divisions. The only significant difference was that male doctors and medical students delivered in the first division and female midwives in the second.

Credit : The Conversation

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Today, more than ever, we are quite aware of the significance of handwashing in disease prevention. We have Ignaz Semmelweis to thank for introducing this life-saving procedure in the mid-1800s.

Ignaz Semmelweis was an Hungarian physician who discovered the cause of puerperal fever (postpartum fever) and was the first to propose an antiseptic policy for physicians. It involved handwashing before and after each medical examination.

Ignaz Semmelweis was born in Hungary. After receiving his doctor of medicine degree from Vienna in 1844, Semmelweis decided to specialise in obstetrics. He began work at the Vienna Hospital, Austria, in 1846. At the time, the maternal mortality rate in Europe was as high as 25-30%. The leading cause was puerperal fever, an infection of the female reproductive organs, that was killing postpartum women.

Semmelweis noticed that women delivered by physicians had a much higher mortality rate than those delivered by midwives. He concluded that the problem was that physicians were handling corpses during autopsies before attending to pregnant women.

Dr Semmelweis theorised that cadaverous particles - microscopic particles from the corpses-would have transferred from doctors hands to the pregnant women, who would then fall victim to the same disease. In 1847, he directed his colleagues to start cleaning their hands and medical instruments with a chlorinated lime solution before each examination.

No sooner than not, the mortality rates due to puerperal fever began to drop drastically. But his superiors refused to accept his theory and he was met with harsh criticism. In 1855, he was appointed professor of obstetrics at the University of Pest. Despite various publications of results where hand washing reduced mortality to below 1%, Semmelweis' observations were largely dismissed. In 1861, he published a book of his findings in Etiology, Concept and Prophylaxis of Childbed Fever. In 1865, he suffered a breakdown and was taken to a mental health facility, where he died. It was not until two decades later, when Joseph Lister and Louis Pasteur produced more evidence of the germ theory and antiseptic techniques, that the value of hand washing was appreciated.

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What you need:

Two unopened soda cans (club soda or flavoured, both will do: do not use diet sodas), a sink

What to do:

1. Pick up the first can. Shake it vigorously.

2. Hold it over the sink and snap it open. What happens?

3. Take the second can and shake that vigorously too.

4. Now, hold it in the palm of one hand, and using your index finger, tap or flick the can on all sides. Make sure you cover all the walls.

5. Now, open the can.

What happens:

On being opened, the first can swooshes up most of its contents in a foamy fountain. When the second can is opened, after it has been tapped on all sides, there is no foaming. You can actually enjoy the whole soda!

Why?

The fizz in the soda is actually carbon dioxide gas. When cold drinks are manufactured, a lot of carbon dioxide is dissolved in the liquid much more than the liquid can hold at normal atmospheric pressure (that is why cold drinks are also called 'carbonated' drinks). To do so, a large amount of pressure is applied.

When you open a can of soda, some of the carbon dioxide gas escapes but enough remains in the liquid so you get a fizzy taste. This carbon dioxide is visible in the form of bubbles.

When you shake a sealed can of soda, the carbon dioxide bubbles settle on the inner walls of the can. When you open this can you release the pressure inside. That means, the pressure of the can's contents falls rapidly. There is a relationship between the pressure of a gas and its volume (the number of particles/molecules packed in a small space): it was discovered by a scientist named Robert Boyle and is known as Boyle's law. According to this law, at a constant temperature, when the pressure of a gas decreases, its volume increases, and vice-versa.

So, when the pressure of the gas in the can falls, its volume suddenly increases and the bubbles multiply and swooosh! From the walls of the can the bubbles rapidly try to get to its mouth to escape. They push the liquid out too because it is in their way. That's how you get sprayed. That is why, after shaking the can, you need to tap sides. This helps dislodge the carbon dioxide bubbles from the can's walls. Once dislodged, they settle on the top of the liquid (because a gas is usually lighter than a liquid). That way, when you open the can, the carbon dioxide escapes comfortably. There is no liquid obstructing its way which means clean clothes for us, yay!

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What you need:

A small plastic glass, two drinking straws, scissors, three paperclips and a drawing pin, two small candles that can fit into the straw, a matchbox a newspaper, a ruler

What to do:

1. Place a newspaper or mat on a table (something you don't mind getting wax on).

2. Poke a hole through the bottom of the plastic glass using the scissors. Make the hole big enough so that the straw just passes through it.

3. Place the glass upside down on the newspaper and stick the straw through it like a flag post.

4. Measure the length of the second straw using the ruler and mark its centre. Poke a hole right through the centre using the drawing pin.

5. Unfold one of the paperclips as shown in the picture. Slide the open end of the clip through the holes you have just made in the straw. Rest the straw at the base of the bend.

6. Push the bent side of the clip into the first straw that is sticking out through the glass. Both the straws should look like a seesaw now.

7. Insert a candle (the wickless end) into each end of the second straw and use paperclips to hold them in place. Balance the seesaw by sliding the candles in or out of the second straw to equalize their weight.

8. Light one candle. Wait for a few seconds and then light the other one.

What happens:

Once both candles are lit, the candles start moving up and down in a seesaw swing. Gradually, this swing changes into a twirl and the candles begin to rotate.

Why?

In a normal playground seesaw, you use your legs to move yourself up and your weight to push yourself down. In case of the poor leg-less candles, their wax does the work for them.

Since you have lit one candle before the other, it starts to drip first, shedding wax. As the wax falls off that candle's weight reduces and it rises up. Then, you light the second candle. Since this candle is angled downwards, its wax drips faster and it becomes lighter quicker. That means, it moves up. As the candles drip and shed wax they keep moving up and down according to the difference in their weights. Gradually, the swinging motion of the candles increases so much that they start rotating.

Had you lit both the candles at the exact same time, there would have been no seesawing because both candles would have lost wax at the same rate.

Picture Credit : Google

What you need:

A cloth rag, two glasses, a plate, string, scissors, washing soda, hot water

What to do:

1. Fill the two glasses with hot water. Add about half a cup of washing soda into each glass. Keep the glasses on a table or on the floor.

2. Fold the rag diagonally and then roll it up tightly.

3. Cut three equal lengths of string. Tie the rolled-up rag at the centre and the sides using the string.

4. Trim off the extra length of the string.

5. Place either end of the rag into a glass. Lower the centre of the rag so that it dips downwards.

6. Place the plate underneath this dip and leave the set-up undisturbed for three to five days. Keep observing it.

What happens:

Gradually, a stalactite of washing soda is formed. It hangs from the dip in the rag and reaches the plate underneath!

Why?

First, washing soda is added to hot water which is more accepting than cold water so you can dissolve an excess of washing soda in the water while it's hot

This washing soda solution travels up the cloth through a process called capillary action Capillary action is the movement of a liquid against gravity through narrow spaces This is the same principle that allows water to be absorbed by a tree's roots and transported to its leaves

In this case, narrow spaces or capillanes are present in the cloth they absorb water and pull it upward

This happens until the cloth gets so full of the solution that it cannot hold any more. That's when the extra washing soda starts dripping from the doth onto the plate As the water cools, it cannot keep the excess washing soda dissolved and deposits it on the rag or on the plate, giving you a soda pillar!

Picture Credit : Google

What you need:

A strong magnet (the stronger the better), a Ziploc bag, any breakfast cereal that claims to have iron in it, water

What to do:

1. Put one cup of cereal in the Ziploc bag.

2. Pour warm water over it. The water should only fill about half the bag so there is an air pocket inside.

3. Seal the bag and mix its contents by shaking it around for a minute.

4. Let the mixture sit for an hour so that the cereal becomes soggy and dissolves in the water.

5. Place the magnet in one palm and place the bag over it. Put your other hand on top of the bag. Now, swivel the bag around for a minute.

6. Turn the bag over so that the magnet is now on top. The liquid falls to the base of the bag and in the air pocket, you can see what the magnet is holding up.

What happens:

Small shavings are stuck to the magnet through the bag.

If this doesn't happen for you, look for a stronger magnet or a different brand of cereal.

Why?

Many breakfast cereals are fortified which means they contain added vitamins and minerals that our body needs. These minerals include iron. Our body needs iron but cannot produce it. So it absorbs what it needs from the food we eat. Natural foods such as legumes, nuts, eggs and meat contain iron. To make cereals nutritious, manufacturers add food-grade iron to them. The quantity of this iron is very small which is why you need such a strong magnet to find it!

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Yes, banks have therapists known as wealth psychologists or counsellors who help their uber-rich clients to cope with issues arising out of their guilt about being wealthy. They also advise them on how to raise their children without them getting spoilt by wealth, and on inheritance issues.

Wealth psychologists assist many modern wealthy families, most of which built their wealth in one generation. They may not be comfortable with all aspects of being rich, and may have a lot of guilt associated with it. Even for those people who find themselves financially prepared, more are beginning to realize they may not be psychologically or emotionally prepared to cope with wealth. Ample evidence points to the notion that the more people are prepared in this way, the happier they are throughout their remaining life stages. The younger people are when they begin to work toward full preparation, the more productive their lives.

Financial planning that emphasized the quantitative side of life has given way to a practice intended to broaden the scope and clarity of one’s vision of the future, and the values that drive the commitment to living a full and complete life. Expectations of longer lives, uncertainty over a frail economy, fear of market risk, disillusionment with government and concerns over world chaos are contributing factors to new attitudes about money and happiness.

Some private wealth management and financial services firms retain wealth psychologists to train their financial advisors or provide individual counseling to clients. Wealth psychologists are increasingly included as a part of a client’s advisory team engaged in a holistic financial planning process. Their focus is on helping clients better understand their values, attitudes, and beliefs about money to better cope with self-limiting or self-destructive behaviors at the center of their relationship with money or with a family of wealth.

Credit :  Investopedia 

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The mockingbird was given its name because of its ability to mimic the calls of dozens of other bird species. In fact, the mockingbird's Latin name, Mimus polyglottos, means many-tongued mimic. The mockingbird has even been known to mimic the sounds of dogs and sirens!  The mockingbird is especially vocal on moonlit spring nights.

It ranges from the northern United States to Mexico—or to Brazil, if the tropical mockingbird (M. gilvus) is considered a race rather than a separate species—and has been introduced into Hawaii. It thrives in suburban areas. This bird sings from high perches and vigorously defends its territory; it may even sing at night.

Other species of Mimus range from Central and South America to Patagonia, and the blue mockingbird (Melanotis) inhabits much of Mexico. The Galapagos mockingbird (Nesomimus) has various races or subspecies on the different islands, showing an adaptive radiation similar to, but not as extreme as, that found in the Galapagos finch.

Credit : Britannica 

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Have you ever wondered why mockingbirds mimic other birds? Scientists believe that mockingbirds imitate the calls of other birds to deter them from settling in their territory, by giving them the impression that the place is already crowded. It is said that a mockingbird is capable of mimicking over 200 songs. In addition to bird songs, the bird can replicate dog barks, sirens and other sounds in the environment.

Scientists aren't sure about why mockingbirds mock, though. Gammon says that robins and cardinals don't change their behavior when northern mockingbirds imitate their calls. Therefore, it seems unlikely that the mockingbirds are trying to manipulate other species through vocal mimicry.

An adult male mockingbird can emit up to 200 distinctive noises. You might be surprised to learn that these birds do have songs of their own, melodies that are not lifted from other avian species. Mockingbirds are most likely to imitate sounds — like titmouse cries, cardinal chirps, and yes, even car alarms — that are acoustically similar to the rhythm and pitch of their own voices. Nobody knows why that is.

Credit : How Stuff Works 

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Have you heard of the Global Seed Vault in the Svalbard archipelago? Almost one million seed samples from all over the world are stored here for humanity's use in the event of a major global disaster. Opened in February 2008, the seed vault was built by Norway deep inside an Arctic mountain on the remote island of Spitsbergen.

It was the recognition of the vulnerability of the world’s genebanks that sparked the idea of establishing a global seed vault to serve as a backup storage facility. The purpose of the Vault is to store duplicates (backups) of seed samples from the world’s crop collections.

Permafrost and thick rock ensure that the seed samples will remain frozen even without power. The Vault is the ultimate insurance policy for the world’s food supply, offering options for future generations to overcome the challenges of climate change and population growth. It will secure millions of seeds representing every important crop variety available in the world today. It is the final back up.

Credit : Crop Trust 

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The opossum’s breeding season begins at the end of winter – in this area January and February. While foraging during the night, the male opossum smells a female in heat. Female opossums will accept a male only once during the estrus period. However, if a pregnancy does not result during the 36 hours or so that she is in heat, she will continue to come into estrus in 28 day cycles until breeding is successful.

The opossum gives birth to 16-20 (often more) babies, only 12-13 days after mating – the shortest gestation period of any North American mammal. Newborn opossums are about the size of a grain of rice. They cannot see, but will scramble from their birthplace under their mother’s tail, and wriggle across her hairy belly to the safety of her pouch. Most do not survive the journey, as the youngsters must find a nipple, and there are only 13 nipples. Neonates who do not locate a nipple will perish – each infant opossum must attach itself to one of her nipples.

After just 1 week of suckling, the babies triple their size. In 1 week the birth weight increases ten times. After about 60 to 70 days in the pouch, the youngsters’ eyes finally open, they have some control of their body temperatures, and they have grown to the size of a white-footed mouse, weighing about an ounce. At this time they occasionally release their hold on the nipple. Soon they will venture out of the pouch. When they reach 75 to 85 days of age, they are weaned and seldom go back in the pouch. They will stay with their mother until they are about 3 to 4 months old.

Credit : Wildlife Rescue League 

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The opossum or possum pretends to be dead when threatened. It lies on the ground with its mouth and eyes partially open, baring its teeth and foaming at the mouth. It can play possum' for a few hours-long enough to put off its predator. This enables the marsupial to make good its escape.

The animal doesn’t feel any pain and has no reflexes when this occurs. It even stops blinking its eyes. A possum won’t respond no matter what a predator does, even if swats, bites or breaks the possum’s bones.

Many wild animals are turned off by dead prey, an evolutionary tactic that likely keeps carnivores from consuming diseased food. Most predators will give up on prey that plays possum.

It can take the marsupial anywhere from a few minutes to a few hours to become mobile again. While they can survive these types of encounters, they can still be injured. Scientists have found many possums in the wild wandering around with healed wounds and fractures, likely from being attacked.

In addition to seemingly feigning death, possums have other remarkable traits. They have prehensile tails to climb tree branches, and they’re immune to pit viper venom. Females give birth to up to 18 babies at once just 12 to 14 days after conception.

Credit : Ripleys 

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It affects them like alcohol affects humans, resulting in flying accidents. They also find it difficult to get back to their hive. Not just that, they are prohibited from entering their hive by the other bees at the hive.

After sucking on fermented limes, a drunken bee will return home to its hive (if it can make it back, that is).  Because of the honey bee’s complex and intricate way of communicating through their waggle dance, it is not very difficult for the other members of a colony to detect the drunken bee.  Once spotted, the guard bees of the hive will immediately begin their investigation and punishment.  The rules of the honey bee society are quite strict, and without much thought, the guard bees will begin to bite off the drunken bee’s legs as punishment.  One by one the bee’s legs are torn off, and the poor drunk honeybee doesn’t have much of a chance of living after her traumatic leg removal.  This sort of punishment serves as a warning to the rest of the hive to never stray away from their duties to their colony.

"On the molecular level, the brains of honey bees and humans work the same. Knowing how chronic alcohol use affects genes and proteins in the honey bee brain may help us eventually understand how alcoholism affects memory and behavior in humans, as well as the molecular basis of addiction,” stated Julie Mustard, a study co-author and a postdoctoral researcher in entomology at Ohio State University.  Mustard studied the effects that ethanol (the intoxicating agent in liquor) had on honeybee behavior.  This study could eventually prove the long term and social effects that alcohol has on human behavior.

Credit :  Ripleys 

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Brookesia micra at less than one inch is the smallest chameleon on record. Found in Madagascar, it's also one of the smallest vertebrates on Earth. The Parson's chameleon, also found in Madagascar, is the largest chameleon species on record. It can grow up to 27 inches long.

For nine years, Brookesia micra, a cousin of B. nana described in 2012, clung to the title of tiniest chameleon. B. nana is smaller than B. micra in body size, measured from snout to cloacal opening at the base of the tail. But it sports a longer tail. Differences in how size is determined make it complicated to definitively claim that a species is the planet’s littlest.

A branch of Brookesia chameleons exhibits extreme miniaturisation, leaving scientists scouring dictionaries for synonyms for small. There is already a Brookesia minima, so the researchers settled on nana, derived from the Latin word for dwarf. Glaw and his colleagues published their findings in a recent paper in Scientific Reports.

Credit : Mongabay

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There are many opportunities available for developers, and with the advent of new technologies such as blockchain, IOT (the Internet of Things), Al / ML (artificial intelligence / machine learning), AR / VR (augmented reality / virtual reality), etc., opportunities in technology are growing rapidly. In this article, we will discuss what kinds of programming jobs are out there, the possibilities in each job, and the associated work in each of these.

Web development: Web developers are usually responsible for building websites and web applications, and the area comprises three major specialisations-front end, back end, and full stack. A lot of developers and programmers start their careers as web developers, and eventually branch into different specialisations later in their careers.

App development: There are millions of apps hosted on app store platforms, and the number is only increasing with time. Now, to build, maintain, and run these applications smoothly, an app developer comes into play. An app developer is someone whose primary responsibilities include creating, testing, and programming apps for computers, mobile phones, and tablets. With the inclusion of AR / VR and other cool technologies into apps, the scope for app developers has further broadened.

Game development: Gaming is a massive industry employing millions of people to develop, and maintain existing games. With AR / VR, the potential of gaming companies can be massive, and now is a great time to be in this industry.

Product management: It is perfect for someone who has a knack of working with people. Product managers work with developers and engineers, communicating with other teams, translating their requirements into tech requirements, and getting them implemented by engineers

App Network and cyber security: What if someone tries to hack into your systems, or use a security vulnerability to their advantage? Or what if they steal private data? Network and cyber security is that realm of computer science that deals with securing and protecting computer networks from attacks. Many companies reward people for finding bugs and security loopholes in their systems.

Database management: Database administrators are tasked with securing, organizing, and troubleshooting storage for large amounts of information for companies online. If you love analysing and recovering information as well as fast problem-solving, this could be the coding career for you.

Server administration: A server administrator or admin has the overall control of a server. The server administrator's role is to design, install, administer, and optimise company servers and related components to achieve high performance of the various business functions supported by the servers.

Today there's a massive advantage of being a coder, and the amount of versatility the skill offers is huge. Keep learning, and opportunities will find you.

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