A contig, short for "contiguous sequence," is a term commonly used in genomics and bioinformatics. It refers to a set of overlapping DNA segments that collectively represent a consensus sequence of a certain region of a genome. Contigs are formed during the process of assembling a genome from shorter DNA sequences, such as those obtained from sequencing technologies.

Approximation theory is a branch of mathematics that focuses on how functions can be approximated by simpler or more easily computable functions. It deals with the study of how to represent complex functions in terms of simpler ones and how to quantify the difference between the original function and its approximation. The field has applications in various areas, including numerical analysis, functional analysis, statistics, and machine learning, among others.

A bi-directional delay line is an electronic or optical component designed to introduce a time delay in a signal that can travel in both directions along the line. This means that the signal can be delayed whether it is propagating in one direction or the opposite. Bi-directional delay lines can be implemented in various forms, including: 1. **Electrical Delay Lines**: These are typically made using transmission lines such as coaxial cables or twisted pair cables, often incorporated with electronic components to provide delay.

The Chebyshev pseudospectral method is a numerical technique used for solving differential equations and integral equations with high accuracy. This method leverages the properties of Chebyshev polynomials and utilizes spectral collocation, making it particularly effective for problems with smooth solutions. Here’s a breakdown of the key components: ### Chebyshev Polynomials Chebyshev polynomials are a sequence of orthogonal polynomials defined on the interval \([-1, 1]\).

Fixed-point computation is a method of representing real numbers in a way that uses a fixed number of digits for the integer part and a fixed number of digits for the fractional part. This contrasts with floating-point representation, where the number of significant digits can vary to accommodate a wider range of values. In fixed-point representation, the position of the decimal point is fixed or predetermined.

The angle of incidence in optics refers to the angle formed between an incident ray and the normal to the surface at the point where the ray strikes the surface. The normal is an imaginary line that is perpendicular to the surface at the point of contact. In mathematical terms, if a ray of light is coming in at a certain angle relative to this normal line, that angle is defined as the angle of incidence (typically denoted as \( \theta_i \)).

Aperture has a couple of different meanings depending on the context, but it is most commonly associated with photography and optics. Here are the main definitions: 1. **Photography**: In photography, aperture refers to the size of the opening in a lens through which light passes. It is one of the three critical elements of exposure, alongside shutter speed and ISO. Aperture is usually measured in f-stops (f/numbers), where a lower f-stop (e.g., f/1.

In optics, a caustic refers to the envelope of light rays that are refracted or reflected by a curved surface or by a light source, typically creating a concentrated pattern of light. The term "caustic" can also refer to the pattern of light created on a surface when light shines through a transparent medium like water or glass.

In optics, "coma" refers to a type of optical aberration that occurs when light from a point source does not converge to a single point after passing through a lens or reflecting off a mirror. This leads to a blurring of images, particularly noticeable when viewing off-axis objects. Coma is characterized by distorted images that appear to have a tail or a comet-like shape, hence the name "coma.

Depth of focus is a term used in optics that refers to the range of distances over which a lens can create a sharp image of a subject on a sensor or film. It is closely related to depth of field, but the two concepts apply to different aspects of the imaging process. 1. **Depth of Focus**: This is the distance between the nearest and farthest points from the lens at which the image remains in acceptable focus on the imaging plane (like a film or digital sensor).

Optical aberration refers to the imperfections in the imaging properties of optical systems, such as lenses and mirrors, that prevent them from focusing all incoming light to a single point. These aberrations result in distortions or blurriness in the images produced by these optical devices. There are several types of optical aberrations, each affecting image quality in different ways.

Snell's law, also known as the law of refraction, describes how light rays change direction when they pass from one medium into another with a different refractive index.

The transmission coefficient is a measure used in various fields of physics and engineering, particularly in wave mechanics, optics, and quantum mechanics, to describe the fraction of an incident wave (such as light, sound, or particles) that passes through a barrier or interface.

Affinity electrophoresis is a specialized technique used to separate and analyze biomolecules, usually proteins or nucleic acids, based on their specific interactions with other molecules. This method combines the principles of electrophoresis with affinity chromatography, relying on the specific binding characteristics between an analyte and a ligand. In affinity electrophoresis, the separation process is typically performed on a gel or in a solution where the desired ligand is immobilized.

Alloenzymes are variants of enzymes that have different structural forms but catalyze the same biochemical reaction. These variants arise from allelic differences in the genes that encode the enzyme, leading to slight variations in the amino acid sequence. Alloenzymes can differ in terms of their kinetic properties, stability, and regulation, but they serve the same function within the metabolic pathways of an organism.

Biliprotein is a type of protein that contains bilins as chromophores. Bilins are linear tetrapyrrole compounds that derive from the breakdown of heme, which is a component of hemoglobin and other heme-containing proteins. Biliproteins are found in various organisms, particularly in photosynthetic prokaryotes like cyanobacteria and certain algae.

China National GeneBank (CNGB) is a major biogenetic research facility located in Shenzhen, China. It was established to support the national strategy for biological resources and to promote research in genomics, biotechnology, and biodiversity. The bank serves as a repository of genetic material, including DNA, RNA, and other biological samples, and is aimed at facilitating research in various fields such as agriculture, medicine, and environmental science.

Complement component 5a (C5a) is a small but biologically active peptide that is generated during the complement activation pathway, specifically from the cleavage of complement component 5 (C5) by the enzyme C5 convertase. C5a serves as an important inflammatory mediator and plays a crucial role in the immune system by promoting various responses.

A DNA-encoded chemical library (DECL) is a powerful and innovative technology used in drug discovery and biochemistry that combines the principles of chemistry and molecular biology. It enables the rapid and efficient screening of a large number of compounds for potential biological activity. ### Key Features of DNA-Encoded Chemical Libraries: 1. **Linkage to DNA**: In a DECL, small chemical compounds are covalently linked to unique DNA tags.

DNA-templated organic synthesis is an innovative technique that uses DNA molecules as templates to facilitate the synthesis of organic compounds in a highly selective manner. This method exploits the unique properties of DNA, such as its ability to form specific base-pairing interactions and its structural stability, to guide the assembly of small organic molecules.