APC Science Union · Online Library

A Brief History of Fluorescent-Protein Research and the Mechanisms of Fluorescence Author: 极地冰川 Reviewed by: 未名 Abstract   Green fluorescent protein (GFP), discovered and isolated from the jellyfish Aequorea victoria in 1962, and the red fluorescent protein drFP583, discovered in 1999 in corals of the genus Discosoma, are now among the most widely used proteins across biological research. They are nontoxic to organisms, efficiently emit characteristic fluorescence when excited by light of specific wavelengths, have low molecular weights, are readily incorporated into vectors, and can be expressed in many organisms. These properties give them broad potential in numerous fields. Many fluorescent proteins are already used in practical research. History of Fluorescent-Protein Re ...

The Phases of Earth as Seen from the Moon Author: Congyu Reviewed by: Yuandao and Shiguang   What does Earth look like from the Moon? If you know something about Earth, the Moon, and lunar phases, you may readily notice that something is amiss in this image. The screenshot comes from Horizon Lunar Colony, a map in the game Overwatch. Setting its artistry and visual impact aside, we will begin with Earth and the Moon and introduce a few basic ideas about the phases of celestial bodies. Figure 1: Screenshot from Overwatch. The image greatly exaggerates Earth's apparent size. From the Moon, Earth has an apparent diameter of about 1.9 degrees, only 3.6 times that of the Sun.   The phase of a celestial body is determined by the relative positions of the Sun, the body, an ...

Early Greek Philosophy Author: Михaїл-А-Булгáкoв☦️ Reviewer: Nancy   Early Greek philosophy belonged to Greek culture as a whole and to all Greeks, not only to city-states such as Athens and Sparta. Its thinkers shared the use of ancient Greek for thought, expression, and exchange. They shifted humanity's perspective on the world away from the divine focus of early civilization and toward a human-centered outlook intended to educate and cultivate—regardless of whether the earlier authority came from the gods of Babylon, Assyria, Egypt, or Greece's own Olympus.   Early Greek philosophy reached the Stoics through the selective interpretations of Socrates, Plato, and especially Aristotle. In the hands of the Greek and Latin Church Fathers, it later met Neoplatonism and ...

The Basics of Mineral Description: How to Read a Rock Author: 约翰史密斯   Hello, everyone. Today we will introduce some common terms used to describe the many properties of minerals.   First, why do we need to learn how to describe minerals? The Earth contains an extraordinary variety of mineral deposits. Some specimens that look completely different are actually the same mineral, while others that look remarkably alike have entirely different compositions.   Consider what happens if we judge a specimen only by its most obvious appearance. Take the famous “fool’s gold,” for example:   It may glitter with a golden-yellow shine, but it has nothing to do with gold: it is simply pyrite. And even among iron ores, there are hematite, magnetite, limonite, a ...

How to Use Color Well Author: 时光   How do you “do color” properly? Did that wording send your mind somewhere questionable? No—this is an entirely respectable science article. So let me show you a color picture. Very proper, isn't it? The charming little object below is called a color wheel. It will be the main character in what follows, so take a moment to remember what it looks like.   This article introduces the fundamentals of color and several common ways of building a palette. Color Theory and Color Schemes How Do Humans See Color?   In nature, light travels from a source to the surface of an object. Most illuminated objects absorb part of that light and reflect the rest into our eyes. The reflected light becomes the color we see. If an object absor ...

The Degeneracy of the Genetic Code Author: Shenzhou Reviewed by: Shenzhou   During protein translation, the genetic code establishes the main informational connection between a nucleotide sequence and an amino acid sequence, while tRNA goes on to create the physical connection between them. In other words, the genetic code is the essential bridge linking proteins with nucleotide sequences.   Early in the study of the genetic code, mathematical analysis led some scientists to conclude that only a system in which three bases specify one amino acid could encode all 20 amino acids. Crick later performed experiments in which different numbers of bases were inserted into or deleted from bacteriophages and the resulting phenotypes compared. His results confirmed the hypoth ...

The Cambrian Explosion and Representative Early Life Author: John Smith Reviewed by: Dongda A Few Words Before We Begin   As its name suggests, paleontology studies life from its earliest origins through to the recent past. Geologists have divided Earth's history into many units according to the order of rock strata and the fossils they contain. Much as biology classifies species into kingdom, phylum, class, order, family, genus, and species, the geologic time scale is divided into eons, eras, periods, epochs, ages, and chrons. Every smaller unit belongs within a larger one. The relationship is like that of the Zhìdé era name (583–587), which belongs to the Chen dynasty, itself part of the Northern and Southern Dynasties. Broadly speaking, units larger than a period span too ...

Culture and Consumer Society I: Milk Tea and Sneakers, Please Author: 涛声 Reviewer: 观复·钧天   A few days ago, Taotao's WeChat Moments and Qzone feeds were flooded with posts about "the first cup of milk tea in autumn":   Whatever. Taotao was not jealous at all, QAQ. One post did catch his attention, though:   Interesting.jpg. After thinking for a long time, Taotao realized that "Is the 'first cup of milk tea in autumn' a capitalist scam?" is not an easy question. The question does reveal something, however: our buying behavior is shaped not only by our empty wallets and less-than-careful calculations, but also by cultural factors and ideas.   Examples are everywhere in a consumer society. Sneakers, anime merchandise, the first milk tea of autumn, ...

Author: Abaiter Reviewer: Shiguang   Russia has a uniquely dramatic history of spaceflight. Following its development over time, this article offers a brief account, analysis, and review of the Russian, Soviet, and post-Soviet Russian space programs along two main threads: theory and engineering. For each spaceflight theory, we will introduce its mechanical principles and engineering applications from a quantitative perspective. For each mission, we will collect as much information as possible about its scientific objectives, payload parameters, and instruments. For each space transportation system, we will give figures such as its payload capacity to different orbits and its specific impulse. This will let us see directly how Russian and Soviet spaceflight rose and declined, b ...

Protein Translation Author: Shenzhou Reviewed by: Shenzhou and Myelin   Proteins are the principal functional molecules responsible for the activities of life, and their biosynthesis is known as translation. Translation is the process in which mRNA serves as a template and, with the aid of a ribosome, tRNA converts the nucleotide sequence on the mRNA into an amino acid sequence to synthesize a polypeptide chain. The main participants are tRNA, rRNA, and mRNA. tRNA carries and transfers amino acids. rRNA combines with several ribosomal proteins to form the ribosome, where polypeptides are translated. mRNA acts as the messenger carrying codons and provides the template for translation. mRNA   Jacob and Monod proposed the concept of messenger RNA in 1961. They reasoned ...