Chandra X-Ray Observatory, We Appreciate You

The maximum life span is a theoretical number whose exact value cannot be determined from existing knowledge about an organism; it is often given as a rough estimate based on the longest lived organism of its species known to date. A more meaningful measure is the average life span; this is a statistical concept that is derived by the analysis of mortality data for populations of each species. A related term is the expectation of life. Life expectancy represents the average number of years that a group of persons, all born at the same time, might be expected to live, and it is based on the changing death rate over many past years.

The concept of life span implies that there is an individual whose existence has a definite beginning and end. What constitutes the individual in most cases presents no problem: among organisms that reproduce sexually the individual is a certain amount of living substance capable of maintaining itself alive and endowed with hereditary features that are in some measure unique. In some organisms, however, extensive and apparently indefinite growth takes place and reproduction may occur by division of a single parent organism, as in many protists, including bacteria, algae, and protozoans. In order to consider life span in such organisms, the individual must be defined arbitrarily since the organisms are continually dividing. In a strict sense, the life spans in such instances are not comparable to those forms that are sexually produced.

There is a brief period during which it is impossible to say whether an organism is still alive, but this time is so short relative to the total length of life that it creates no great problem in determining life span.

Some organisms seem to be potentially immortal. Unless an accident puts an end to life, they appear to be fully capable of surviving indefinitely. This faculty has been attributed to certain fishes and reptiles, which appear to be capable of unlimited growth. Without examining the various causes of death in detail, a distinction can be made between death as a result of internal changes (i.e., aging) and death as a result of some purely external factor, such as an accident. It is notable that the absence of aging processes is correlated with the absence of individuality. In other words, organisms in which the individual is difficult to define, as in colonial forms, appear not to age.

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Which U.S. state has banned some sunscreens from 2021, and why? ☀️ Find out in this month’s edition of #PeriodicGraphics in C&EN: https://ift.tt/2jSN4jl https://ift.tt/2JWdZ71

SwRI’s Parker discovers moon over Makemake in the Kuiper Belt A Southwest Research Institute-led team has discovered an elusive, dark moon orbiting Makemake, one of the “big four” dwarf planets populating the Kuiper Belt region at the edge of our solar system. The findings are detailed in the paper “Discovery of a Makemakean Moon,” published in the June 27 issue of Astrophysical Journal Letters.

“Makemake’s moon proves that there are still wild things waiting to be discovered, even in places people have already looked,” said Dr. Alex Parker, lead author of the paper and the SwRI astronomer credited with discovering the satellite. Parker spotted a faint point of light close to the dwarf planet using data from Hubble’s Wide Field Camera 3. “Makemake’s moon – nicknamed MK2 – is very dark, 1,300 times fainter than the dwarf planet.”

A nearly edge-on orbital configuration helped it evade detection, placing it deep within the glare of the icy dwarf during a substantial fraction of its orbit. Makemake is one of the largest and brightest known Kuiper Belt Objects (KBOs), second only to Pluto. The moon is likely less than 100 miles wide while its parent dwarf planet is about 870 miles across. Discovered in 2005, Makemake is shaped like football and sheathed in frozen methane.

“With a moon, we can calculate Makemake’s mass and density,” Parker said. “We can contrast the orbits and properties of the parent dwarf and its moon, to understand the origin and history of the system. We can compare Makemake and its moon to other systems, and broaden our understanding of the processes that shaped the evolution of our solar system.”

With the discovery of MK2, all four of the currently designated dwarf planets are known to host one or more satellites. The fact that Makemake’s satellite went unseen despite previous searches suggests that other large KBOs may host hidden moons.

Prior to this discovery, the lack of a satellite for Makemake suggested that it had escaped a past giant impact. Now, scientists will be looking at its density to determine if it was formed by a giant collision or if it was grabbed by the parent dwarf’s gravity. The apparent ubiquity of moons orbiting KBO dwarf planets supports the idea that giant collisions are a near-universal fixture in the histories of these distant worlds.

top Image: illustration shows Makemake’s bright red surface and the inferred darker surface of the moon, known as MK2. Image Courtesy of NASA/SwRI/Alex Parker

lower Image: Different views of the Makemake system taken two days apart. Image Courtesy of NASA/Hubble WFC3/SwRI/Alex Parker

This is a 392 year old shark that was recently discovered in the Arctic Ocean.

This guy was wandering the oceans back in 1627 🦈

Antibodies are the secreted form of B-lymphocyte receptors and are a part of adaptive immunity, but how are these proteins formed?

Above is a diagram illustrating Paul Ehlrich’s Side Chain Theory of Antibody Formation. Ehlrich proposed that immunoglobulin molecules, a fundamental component of adaptive immunity, served as membrane bound proteins that bound to particular threats, similarly to the former “key in lock” view of enzymes in catalyzing biological reactions. Ehrlich also suggested that the action of binding a pathogenic molecule to the receptor would generate a signal to stimulate the production of more receptors of the same specificity. These “side chains” that were added on would then break off from the cell surface and become what we call antibodies.

 We now know, however, that soluble immunoglobulin receptors are specially manufactured to be secreted as antibody, rather than just “breaking off” of the lymphocyte, even though they have the same specificity as their membrane-bound counterparts.

The upper atmosphere of the Sun is dominated by plasma filled magnetic loops (coronal loops) whose temperature and pressure vary over a wide range. The appearance of coronal loops follows the emergence of magnetic flux, which is generated by dynamo processes inside the Sun. Emerging flux regions (EFRs) appear when magnetic flux bundles emerge from the solar interior through the photosphere and into the upper atmosphere (chromosphere and the corona). The characteristic feature of EFR is the Ω-shaped loops (created by the magnetic buoyancy/Parker instability), they appear as developing bipolar sunspots in magnetograms, and as arch filament systems in Hα. EFRs interact with pre-existing magnetic fields in the corona and produce small flares (plasma heating) and collimated plasma jets. The GIFs above show multiple energetic jets in three different wavelengths. The light has been colorized in red, green and blue, corresponding to three coronal temperature regimes ranging from ~0.8Mk to 2MK. 

Image Credit: SDO/U. Aberystwyth

I’ve been receiving tonnes of questions on Note - Taking recently, so I’d thought I make a post. Plus, I had fun making these graphics.

There are three different methods that I prefer when it comes to note taking:

Notes written During the Lecture

I highly recommend taking notes during the lecture.

I also use abbreviations for quicker and more efficient note taking. Some examples of abbreviation that I use are:

w/ - With

w/o - Without

e.g. - For example

Notes written After the Lecture

As for notes written after the lecture, I tend to seek the help of Google Spreadsheets or Microsoft Excel. This way I am able to organise information learnt. I do this by dividing the information provided into two columns, one for keywords or questions and the other for definitions and answers. 

*Note: This method was adapted from the note taking method I’ve used during college. 

Rewritten Notes

I also rewrite my notes. My rewritten notes are arranged based on the order they appear in the syllabus unless there are pieces of information that are related to more than one topic.

I use a black pen or pencil for my written notes, as well as coloured pens and highlighters to highlight the key words and terminologies for emphasise.

Before writing them down, I tend to visualise the layout - alternating between words and pictures/diagram. This definitely helps me with remembering for exams. All I have to do is imagine that I’m looking at that page and I can remember where everything is.

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Please click on the images for a much clearer view. 

Well, that’s all from me! I hope that you found this information helpful. And, don’t hesitate to ask me questions if you’re confused about this method of note-taking, or any other problems you might have. For more information of how to survive university, follow this page. And, for more medical school chronicles, follow me on IG. Follow my studygram/medgram for more content. 

Well, this is definitely the most fun I’ve had while making a post.

Inspired by this one from capnphaggit. Images & copyrights: Trifid Nebula (M20) by Marcus Davies, The Cat’s Eye Nebula and Star-forming region Sharpless 2-106 by NASA, ESA, the Hubble Heritage Team (STScI/AURA). Please don’t remove the credits.

If someone is attractive and charming, you’re more likely to assume they’re intelligent and hard working- even if they’re not. 

Known as the ‘Halo Effect’, it’s a theory that our generalized judgements of people can bleed over into the more specific judgements we make about them. Studies show that even though we understand the Halo Effect intellectually, it’s almost impossible for us to recognize when it’s actually happening. 

(Source, Source 2)