Glacier ice is actually a mono-mineralic rock (a rock made of only one mineral, like limestone which is composed of the mineral calcite).
The mineral ice is the crystalline form of water (H2O).
Glacier ice forms through the metamorphism of tens of thousands of individual snowflakes into crystals of glacier ice. Each snow flake is a single, six-sided (hexagonal) crystal with a central core and six projecting arms.
The metamorphism process is driven by the weight of overlying snow.
During metamorphism, thousands of individual snowflakes recrystallize into much larger and denser individual ice crystals. Some of the largest ice crystals observed at Alaska’s Mendenhall Glacier are nearly one foot in length.
Antarctica is Earth’s southernmost continent
It contains the geographic South Pole and is situated in the Antarctic region of the Southern Hemisphere. It lies almost entirely south of the Antarctic Circle, and is surrounded by the Southern Ocean.
Here we see Antarctica on the left. For comparison we shop the Earth’s geographic north pole on the right:
At 14,200,000 square kilometres (5,500,000 square miles), it is the fifth-largest continent and nearly twice the size of Australia.
It is by far the least populated continent, with around 5,000 people in the summer and only around 1,000 in the winter.
About 98% of Antarctica is covered by ice that averages 1.9 km (1.2 mi; 6,200 feet) in thickness,
It is the coldest, driest, and windiest continent. It has the highest average elevation of all the continents.
Most of Antarctica is a polar desert, with annual precipitation of 200 mm (7.9 in) along the coast and far less inland; yet 80% of the world’s freshwater reserves are stored there, enough to raise global sea levels by about 60 metres (200 feet) if all of it were to melt.
Organisms native to Antarctica include many types of algae, bacteria, fungi, plants, protista, and certain animals, such as mites, nematodes, penguins, seals and tardigrades. Vegetation, where it occurs, is tundra.
Under the ice cap
Here’s What Antarctica Looks Like Under All The Ice Colin Schultz, Smithsonian Magazine, 6/5/2013
video: The Bedrock Beneath Antarctica – NASA, NASA Goddard
Possible mantle plume under the continent
“The possibility that a deep mantle plume manifests Pliocene and Quaternary volcanism and potential elevated heat flux in West Antarctica has been studied for more than 30 years. Recent seismic images support the plume hypothesis as the cause of Marie Byrd Land (MBL) volcanism and geophysical structure”
Influence of a West Antarctic mantle plume on ice sheet basal conditions, Helene Seroussi, Erik R. Ivins, Douglas A. Wiens, Johannes Bondzio, Journal of Geophysical Research: Solid Earth, Vol 122(9) 2017
Antarctica was the last region on Earth to be discovered, likely unseen until 1820 when the Russian expedition of Fabian Gottlieb von Bellingshausen and Mikhail Lazarev sighted the Fimbul ice shelf.
The continent remained largely neglected for the rest of the 19th century because of its harsh environment, lack of easily accessible resources, and isolation.
In January 1840, land at Antarctica was discovered for the first time, almost simultaneously, by the United States Exploring Expedition, under Lieut; Charles Wilkes; and a separate French expedition under Jules Dumont d’Urville. The latter made a temporary landing. The Wilkes expedition—though it did not make a landing—remained long enough in the region to survey and map some 800 miles of the continent. The first confirmed landing was by a team of Norwegians in 1895.
Antarctica is governed by parties to the Antarctic Treaty System. Twelve countries signed the Antarctic Treaty in 1959, and thirty-eight have signed it since then. The treaty prohibits military activities, mineral mining, nuclear explosions and nuclear waste disposal. It supports scientific research and protects the continent’s ecology.
Between 1,000 and 5,000 people from many countries reside at research stations scattered across the continent.
What is earth science?
The earth sciences include studies of the atmosphere, hydrosphere, cryosphere, and the relations among them and with the biosphere. Study of the earth sciences directly addresses several issues of great societal concern, including but not limited to natural disasters such as devastating hurricanes, and the global effects of a changing climate.
The earth sciences connect the world of science with all students’ daily experiences: The weather is a never-ending “science experiment” in progress outside classroom windows. Teachers with sound training in the earth science basics have endlessly interesting and relevant material to draw upon that connects science with the students’ past experiences and daily lives.
Earth science helps students see how all of the sciences are related because to study the Earth, scientists and students must use the knowledge and techniques of several disciplines, including but not limited to physics, chemistry, mathematics, and computer science. Learning about the Earth helps students realize that their world is made of interconnected, dynamic systems.
In addition, the earth sciences, and especially weather, connect science with the world students come to know through the news media, especially television. Surveys over the past several years have shown that television is the primary source of news for the majority of Americans. With the exception of weather, most of the science that television news presents is about health and medicine. In fact, television weathercasters are likely to be the only representatives of science students and their parents regularly see….
The value of earth science classes goes beyond the intellectual benefits. Over the years, various reports have testified to the life-saving value of earth science education. One of the most dramatic of these came from the 26 December 2004 tsunami that devastated coastal areas around the Indian Ocean, killing as many as 300,000 people. A British schoolgirl, who had studied tsunamis in school, recognized precursors of the tsunami that was about to hit the beach in Thailand she was visiting. The schoolgirl persuaded her mother to shout a warning, which is credited with saving 100 people on the beach.
In the United States, students in earth science classes learn how to react when endangered by tornadoes, hurricanes, floods, lightning, and other hazards….
Students who study the earth sciences will better understand the value of the Earth’s resources, how its components are related, and the need to care for the Earth. Men and women who possess a basic understanding of the Earth will be able to participate as informed citizens in policy debates, such as about climate change. Society will be the ultimate beneficiary as its citizens become more aware of the science that explains weather, earth’s water, the oceans, and the Earth itself.
– From Earth Science Education, Adopted by American Meteorological Society Council, 29 January 2006. Bull. Amer. Met. Soc., 87
Science is not a position. It is not a person. It is not a group. It has no social or political beliefs. rather, science is a method that allows us to test claims about the physical world in which we live. Science allows us to investigate the nature of reality, and helps reveal our place in the universe.
“In science we approach claims skeptically. That doesn’t mean that that we don’t believe anything. Rather, to be skeptical means we don’t accept a claim unless we are given compelling evidence. Skepticism is a provisional approach to claims.”
– Michael Shermer
As amazing and powerful as science is, however, it has a very specific domain: It only reveals phenomenon in the natural world. Science tells us nothing about right and wrong, good and evil. In other words, science is not about ethics or morality any more than mathematics is. Mathematics is amazing and powerful, and and we combine math with science we can engineer buildings, bridges, skyscrapers, spacecraft. and supercomputers. But math doesn’t say anything about right or wrong.
As such, we should we dubious when we hear claims that indicates science proves or disproves someone’s moral or social beliefs.
A great resource, “Understanding Science,” by the UC Museum of Paleontology of the University of California at Berkeley, clarifies:
Science is powerful. It has generated the knowledge that allows us to call a friend halfway around the world with a cell phone, vaccinate a baby against polio, build a skyscraper, and drive a car. [Yet] science has definite limits.
Science doesn’t make moral judgments
When is euthanasia the right thing to do? What universal rights should humans have? Should other animals have rights? … ultimately, individual people must make moral judgments. Science helps us describe how the world is, but it cannot make any judgments about whether that state of affairs is right, wrong, good, or bad.
Science doesn’t make aesthetic judgments
Science can reveal the frequency of a G-flat and how our eyes relay information about color to our brains, but science cannot tell us whether a Beethoven symphony, a Kabuki performance, or a Jackson Pollock painting is beautiful or dreadful. Individuals make those decisions for themselves based on their own aesthetic criteria.
Science doesn’t tell you how to use scientific knowledge
… Science, for example, can tell you how to recombine DNA in new ways, but it doesn’t specify whether you should use that knowledge to correct a genetic disease, develop a bruise-resistant apple, or construct a new bacterium.
There is no scientific experiment that one can possibility make that will tell us right from wrong, good from evil.
There is no peer-reviewed scientific evidence that proves that one should love one’s brother or that one should be racist.
There is no peer-reviewed scientific evidence that proves that we should either “share our bread with the hungry and bring the homeless into our house” (Isaiah 58:7) or that we should ignore or shun the hungry and the homeless.
There is no peer-reviewed scientific evidence that proves that we should judge people not “by the color of their skin but by the content of their character.” (Martin Luther King Jr.) or whether we should judge people from external appearances.
There is no experimental morality meter. Science doesn’t measure “goodness.”
A classic illustration of the intersection of ethics and science can be seen in the classic painting, An Experiment on a Bird in the Air Pump. It is by Joseph Wright, 1768. Science allows us to investigate air pressure, and the nature of vacuums. Science allows us to understand how varying air pressure affects the health of people and animals. But no scientific experiment can tell us whether or not it is ethical to perform experiments on animals, or if so, under what circumstances.
Scientists on science and morality
I do not believe that a moral philosophy can ever be founded on a scientific basis. … The valuation of life and all its nobler expressions can only come out of the soul’s yearning toward its own destiny. Every attempt to reduce ethics to scientific formulas must fail. Of that I am perfectly convinced.
Albert Einstein, ‘Science and God: A Dialogue’, Forum and Century (June 1930), 83, 374
Misuse of science: Examples
It is the mark of an educated mind to be able to entertain a thought without accepting it.
– Aristotle (384- 322 BCE)
If you want to build a ship, don’t drum up people together to collect wood and don’t assign them tasks and work, but rather teach them to long for the endless immensity of the sea.”
― Antoine de Saint-Exupéry
“There’s a lot of talk these days about giving children self-esteem. It’s not something you can give; it’s something they have to build. Coach Graham worked in a no-coddling zone. Self-esteem? He knew there was really only one way to teach kids how to develop it: You give them something they can’t do, they work hard until they find they can do it, and you just keep repeating the process.”
― Randy Pausch (1960-2008), The Last Lecture
“The pupil who is never required to do what he cannot do, never does what he can do.”
– John Stuart Mill (1806-1873)
“Most learning isn’t fun. Learning takes work. Discipline. Commitment from both teacher and student. Responsibility – you have to do your homework. There’s no shortcut to a quality education.”
– Clifford Stoll, High Tech Heretic
Most learning isn’t fun. Learning takes work. Discipline. Commitment, from both teacher and student. Responsibility. Many subjects aren’t fun. I wonder how the fun-to-learn teacher handles the Holocaust, Rape of Nanking, or American slavery… Show me the computer program that encourages quiet reflection. Spending an evening on the World Wide Web is much like sitting down to a dinner of Cheetos, two hours later your fingers are yellow and you’re no longer hungry, but you haven’t been nourished.
– Clifford Stoll, High-Tech Heretic
The nature of science
Science works. It is not perfect. It can be misused. It is only a tool. But it is by far the best tool we have, self-correcting, ongoing, applicable to everything. It has two rules. First: there are no sacred truths; all assumptions must be critically examined; arguments from authority are worthless. Second: whatever is inconsistent with the facts must be discarded or revised. We must understand the Cosmos as it is and not confuse how it is with how we wish it to be. The obvious is sometimes false; the unexpected is sometimes true.
— Carl Sagan
The seeker after the truth is not one who studies the writings of the ancients and, following his natural disposition, puts his trust in them, but rather the one who suspects his faith in them and questions what he gathers from them, the one who submits to argument and demonstration, and not to the sayings of a human being whose nature is fraught with all kinds of imperfection and deficiency.
Thus the duty of the man who investigates the writings of scientists, if learning the truth is his goal, is to make himself an enemy of all that he reads, and, applying his mind to the core and margins of its content, attack it from every side. He should also suspect himself, as he performs his critical examination of it, so that he may avoid falling into either prejudice or leniency.
Ibn al-Haytham (Alhazen) 965 CE- 1040 CE. Quoted in ‘Aporias (Doubts) Concerning Ptolemy’. Ibn al-Haytham, Brief life of an Arab mathematician, Abdelhamid I. Sabra
I have a friend who’s an artist and he’s some times taken a view which I don’t agree with very well. He’ll hold up a flower and say, “look how beautiful it is,” and I’ll agree, I think. And he says, “you see, I as an artist can see how beautiful this is, but you as a scientist, oh, take this all apart and it becomes a dull thing.” And I think he’s kind of nutty.
First of all, the beauty that he sees is available to other people and to me, too, I believe, although I might not be quite as refined aesthetically as he is. But I can appreciate the beauty of a flower. At the same time, I see much more about the flower that he sees. I could imagine the cells in there, the complicated actions inside which also have a beauty. I mean, it’s not just beauty at this dimension of one centimeter: there is also beauty at a smaller dimension, the inner structure…also the processes.
The fact that the colors in the flower are evolved in order to attract insects to pollinate it is interesting — it means that insects can see the color. It adds a question — does this aesthetic sense also exist in the lower forms that are…why is it aesthetic, all kinds of interesting questions which a science knowledge only adds to the excitement and mystery and the awe of a flower. It only adds. I don’t understand how it subtracts.
– Richard Feynman, a nobel prize winning physicist, on ‘The Beauty of a Flower’
“As always in life, people want a simple answer . . . and it’s always wrong.” — Susan Greenfield, neurochemist
Wonder and the universe
People travel to wonder at the height of mountains, at the huge waves of the sea, at the long courses of rivers, at the vast compass of the ocean, at the circular motion of the stars; and they pass by themselves without wondering.
– Saint Augustine of Hippo (354 – 430 CE)
We are the local embodiment of a Cosmos grown to selfawareness. We have begun to contemplate our origins: starstuff pondering the stars; organized assemblages of ten billion billion billion atoms considering the evolution of atoms; tracing the long journey by which, here at least, consciousness arose. Our loyalties are to the species and the planet. We speak for Earth. Our obligation to survive is owed not just to ourselves but also to that Cosmos, ancient and vast, from which we spring.
– Carl Sagan, Cosmos
“The universe is sentient. We all know that. We are the sentient bit. What could consciousness be, except the universe witnessing itself?”
– Steven Moffat
“We believe that the universe itself is conscious in a way that we can never truly understand. It is engaged in a search for meaning. So it breaks itself apart, investing its own consciousness in every form of life. We are the universe trying to understand itself.”
– J. Michael Straczynski
A good many times I have been present at gatherings of people who, by the standards of the traditional culture, are thought highly educated and who have with considerable gusto been expressing their incredulity at the illiteracy of scientists. Once or twice I have been provoked and have asked the company how many of them could describe the Second Law of Thermodynamics. The response was cold: it was also negative. Yet I was asking something which is about the scientific equivalent of: Have you read a work of Shakespeare’s?
– Baron Charles Percy Snow, The Two Cultures: The Rede Lecture (1959), 14-5.
Nothing in life is certain except death, taxes and the second law of thermodynamics. All three are processes in which useful or accessible forms of some quantity, such as energy or money, are transformed into useless, inaccessible forms of the same quantity. That is not to say that these three processes don’t have fringe benefits: taxes pay for roads and schools; the second law of thermodynamics drives cars, computers and metabolism; and death, at the very least, opens up tenured faculty positions.
– Seth Lloyd, Nature 430, 971 (26 August 2004)
Perhaps the best ever introduction in a physics textbook: – “Ludwig Boltzmann, who spent much of his life studying statistical mechanics, died in 1906 by his own hand. Paul Ehrenfest, carrying on the work, died similarly in 1933. Now it is our turn to study statistical mechanics.”
David Goodstein, “States of Matter” Chapter 1
“Nothing in Biology Makes Sense Except in the Light of Evolution”
– Theodosius Dobzhansky (1900-1975)
An immunologist and a cardiologist are kidnapped. The kidnappers threaten to shoot one of them, but promise to spare whoever has made the greater contribution to humanity. The cardiologist says, “Well, I’ve identified drugs that have saved the lives of millions of people.” Impressed, the kidnappers turn to the immunologist. “What have you done?” they ask. The immunologist says, “The thing is, the immune system is very complicated …” And the cardiologist says, “Just shoot me now.”
– Jessica Metcalf of Princeton
What an astonishing thing a book is. It’s a flat object made from a tree with flexible parts on which are imprinted lots of funny dark squiggles. But one glance at it and you’re inside the mind of another person, maybe somebody dead for thousands of years. Across the millennia, an author is speaking clearly and silently inside your head, directly to you.
Writing is perhaps the greatest of human inventions, binding together people who never knew each other, citizens of distant epochs. Books break the shackles of time. A book is proof that humans are capable of working magic.
Carl Sagan, Cosmos: A Personal Voyage, Persistence of Memory [Episode 11]
As seen from here on Earth, our moon has a number of types of wobble. Here we will look at each of them.
Over the course of a month, we see a bit more than half of the moon’s surface from here on Earth. This apparent motion is called lunar libration.
About 59% of the Moon’s surface is visible, thanks to
Lunar libration in latitude
due to the Moon’s axis being slightly inclined relative to the Earth’s axis. From our angle we can at one time peek over the north pole of the Moon, and then later in the lunar month we peek over the south pole. Over the entire four week cycle it gives the the effect of the Moon slowly “nodding its head yes.”
Diurnal (daily) libration
due to the observer first viewing from the western edge of the Earth as the Moon is rising, and then later from up to four thousand miles away to the east as the Moon is setting. This is due to the rotation of the Earth. The difference in perspective between the rising and setting of the Moon appears as a slight turning of the Moon first to west and then to east, as though “shaking its head no.”
Libration of longitude
an effect of the Moon’s varying rate of travel along its slightly elliptical orbit around the Earth. The Moon travels faster when it is at its closest to Earth, and its slowest when it is farthest away. Its rotation on its own axis is more regular, the difference appearing again as a slight east-west “no” oscillation.
— Skywise Unlimited, Astronomy 101
Why is there lunar libration? See this GIF from space.fm.
Lunar Axial precession
The rotational axis of the Moon undergoes precession.
What is precession? It is a change in the orientation of the rotational axis of a rotating body.
If the axis of rotation of a body is itself rotating about a second axis then that body is said to be precessing about the second axis.
Since the Moon’s axial tilt is only 1.5° with respect to the ecliptic (the plane of Earth’s orbit around the Sun), this effect is small.
Once every 18.6 years the lunar north pole describes a small circle around a point in the constellation Draco.
Correspondingly, the lunar south pole describes a small circle around a point in the constellation Dorado.
Lunar Apsidal precession
The major axis of the Moon’s elliptic orbit (the line of the apsides from perigee to apogee) precesses eastward by 360° in approximately 8.85 years.
This is the reason that an anomalistic month (the period the Moon moves from the perigee to the apogee and to the perigee again) is longer than the sidereal month (the period the Moon takes to complete one orbit with respect to the fixed stars).
Here we see the moon’s orbit apsidal precession: Lunar Apsidal motion
Precession of the plane of the Moon’s orbit.
The period = the time it takes the ascending node to move through 360° relative to the vernal equinox (autumnal equinox in Southern Hemisphere).
The period is about 18.6 years.
The direction of motion is westward, i.e. in the direction opposite to the Earth’s orbit around the Sun, if seen from the celestial north.
Investigate: Is this animation in the right section?
This is the reason that a draconic month or nodal period (the period the Moon takes to return to the same node in its orbit) is shorter than the sidereal month.
After one nodal precession period, the number of draconic months exceeds the number of sidereal months by exactly one. This period is about 6,793 days (18.60 years).
These quotes came from the Ask Dr. Math, forums. That web page no longer exists, so this archive exists here for the use of my students.
What is Mathematics?
Date: 09/22/2000 at 04:40:38
Subject: Definition of maths
Hi, please tell me the definition of maths. If there is no single definition, is there a group of definitions?
Date: 09/22/2000 at 16:15:03
From: Doctor Ian
Subject: Re: Definition of maths
Stripped to its barest essence, mathematics is the derivation of theorems from axioms. So what does that mean?
It means that mathematics is a collection of extended, collaborative games of ‘what if’, played by mathematicians who make up sets of rules (axioms) and then explore the consequences (theorems) of following those rules.
For example, you can start out with a few rules like:
A point has only location.
A line has direction and length.
Two lines interesect at a point.
and so on, and then you see where that takes you. That’s what Euclid did, and ended up more or less inventing geometry. And that’s what other mathematicians have done over the centuries, inventing arithmetic, and number theory, and calculus, and group theory, and so on.
It’s a little like what you do when you invent a board game like chess. You specify that there are such-and-such pieces, and they can move in such-and-such ways, and then you let people explore which board positions are possible or impossible to achieve.
The main difference is that in chess, you’re trying to win, while in math, you’re just trying to figure out what kinds of things can – and can’t – happen. So a ‘chessamatician’, instead of playing complete games, might just sit and think about questions like this:
If I place a knight (the piece that looks like a horse, and moves in an L-shaped jump) on any position, can it reach all other positions?
What is the minimum number of moves that would be required to get from any position to any other position?
But they would also think about questions like this:
What would happen if I changed the shape of the chessboard?
What would happen if I allowed some pieces (‘ghosts’) to move through other pieces as if they weren’t there?
What would happen if I made the board three dimensional, or let pieces disappear for specified periods, or made them appear and disappear at regular intervals (for example, if a rook becomes invisible for three moves, then visible for three, then invisible again, and so on)?
What would happen if I allowed more than two players, or let players take turns in parallel instead of in sequence?
In other words, mathematicians are interested not only in what happens when you adopt a particular set of rules, but also in what happens when you change the rules. For example, mathematicians in Germany and Russia started with Euclid’s geometry, but asked: “What if parallel lines _could_ intersect each other? How would that change things?” And they ended up inventing an entirely new branch of geometry, which turned out to be just what Einstein needed for his theory of general relativity.
I hope this helps. Write back if you’d like to discuss this some more, or if you have any other questions about math.
– Doctor Ian, The Math Forum
My own favorite definition is that math is the study of abstractions. That is, we isolate one or a few features of some kind of object for study, and see what we can learn about the behavior of those features while ignoring everything else about them: features like number, shape, or direction.
For example, when we work with numbers we are taking the concept of counting away from all other details about the things we are counting, such as color or name, and just thinking about how many there are. We learn to work with numbers as an abstract entity, so that we can add two numbers without having to think of them as representing two apples and three apples. When we finish our calculations with numbers, we can come back to the real world and know just how many apples we have.
It is often found that a concept that is first encountered in one part of our experience turns out to be useful in other areas as well. Having solved a problem in one context, we don’t have to solve it
again, because we solved it abstractly.
For example, a common problem is to find the number of sides and diagonals of a polygon. It turns out that the same solution applies also to a question about the number of handshakes that occur if everyone in a room shakes hands with everyone else, and also to a problem about the number of different ways a student could choose two classes to take.
They all look the same when you think of them abstractly. If I know the solution to one of these problems, I can transform a new problem into the known problem, and quickly find the answer. That kind of thinking is central to what math is.
As you go more deeply into math, you find that we end up studying abstractions of abstractions, such as systems of objects that behave like numbers, but don’t follow all the same rules.
This turns out to be surprisingly useful; for example, rotations of an object in space, thought of as if they were a sort of number, can be handled very neatly, even though they work very differently from numbers in some respects.
As you can see, math goes far beyond arithmetic, or even algebra and geometry. All sorts of logical thinking fit this description. And math is a very creative field, involving exploration of the unknown, not just learning rules we are told to follow.
Mathematicians invent abstract worlds, and discover all the surprises in them that are never noticed by those who don’t look for the abstractions behind the reality.
09/14/2001 at 23:35:33
This website is educational. Materials within it are being used in accord with the Fair Use doctrine, as defined by United States law.
§107. Limitations on Exclusive Rights: Fair Use. Notwithstanding the provisions of section 106, the fair use of a copyrighted work, including such use by reproduction in copies or phone records or by any other means specified by that section, for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright. In determining whether the use made of a work in any particular case is a fair use, the factors to be considered shall include: the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes; the nature of the copyrighted work; the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and the effect of the use upon the potential market for or value of the copyrighted work. (added pub. l 94-553, Title I, 101, Oct 19, 1976, 90 Stat 2546)
What is antimatter?
How was it predicted/discovered?
How can we harness power from it?
What is malaria?
Malaria is a communicable disease caused by a protist.
Protists are not plants, animals, fungi, or bacteria. They are their own branch of life on Earth. To learn more about protists click here.
Malaria can be caused by several species of Plasmodium parasites, each of which has a complex life cycle (see illustration).
Parasites enter a host’s blood through the bite of an infected mosquito.
The parasites infect the host’s red blood cells, causing fever, joint pain, anemia, and fatigue.
Where is malaria endemic?
Malaria is common in tropical and subtropical climates.
It is one of the most common infectious diseases on the planet.
It kills several million people each year, most of them children.
A tremendous amount of research has gone in to developing a malaria vaccine. Currently, scientists have developed one weak vaccine, that offer 25% to 50% protection. Further improvements are expected.
Malaria parasites are transmitted to human hosts by female mosquitoes of the genus Anopheles.
A diverse group of Anopheles (30 to 40 species) serves as vectors of human disease.
So-called “uncomplicated” malaria entails a series of recurring episodes of chills, intense fever, and sweating. This sometimes includes other symptoms such as headache, malaise, fatigue, body aches, nausea, and vomiting.
In some cases, and especially in groups such as children and pregnant women, the disease can progress to “severe malaria.”
This includes cerebral malaria/coma, seizures, severe anemia, respiratory distress, kidney and liver failure, cardiovascular collapse, and shock.
Long-term impacts include death, disability, and significant socioeconomic burden on societies where the disease is prevalent.
Why haven’t we had effective malaria vaccines?
John Timmer writes
The disease is not caused by just a single infectious agent. Instead, Malaria comes from several related species in the Plasmodium genus.
Plasmodium falciparum typically causes more severe illnesses and has thus been the target of most vaccine efforts.
There are various regional strains that differ in ways that can be significant for immune system recognition.
Even a single strain doesn’t present an easy target for an immune response, though. The parasites undergo several distinct stages within the human body, with different proteins associated with each. And the parasite can alter other proteins on its surface to act as decoys that distract the immune system.
That said, researchers have gradually identified a handful of proteins that are consistently present on the surface of malarial parasites and are essential for their infectivity. That information has led to the development of vaccines that attempt to generate an immune response to these proteins.
More vaccine progress: This time, it’s malaria, John Timmer, Ars Technica, 6/30/2021
What progress has there been on malaria vaccines?
“We have word of the most effective malaria vaccine yet discovered. A year-long trial in Burkina Faso has shown 77% efficacy, which is by far the record, and which opens the way to potentially relieving a nearly incalculable burden of disease and human suffering.”
Great Malaria Vaccine News, AAAS, Derek Lowe, Science Translational Medicine, 4/23/2021
High Efficacy of a Low Dose Candidate Malaria Vaccine R21 in 1 Adjuvant Matrix-M™, with Seasonal Administration to Children in Burkina Faso, Mehreen S. Datoo et al., 4/20/2021 – Preprint, The Lancet
The Lancet, 2021. DOI: 10.1016/S0140-6736(21)00943-0