The quartet distance is a metric used in phylogenetics to measure the structural similarity between two phylogenetic trees (or trees representing evolutionary relationships). It quantifies how dissimilar two trees are based on the arrangements of their leaf nodes, particularly looking at groups of four taxa (species or organisms). ### Key Points about Quartet Distance: 1. **Quartets**: Given any four taxa, there are three possible ways to arrange them in a bifurcating (or unrooted) tree.
The Short Oligonucleotide Analysis Package (SOAP) is a bioinformatics tool designed for the analysis of short oligonucleotide sequences, particularly in the context of high-throughput sequencing data. SOAP provides a range of functionalities for data processing, including alignment, visualization, and interpretation of sequencing results. Key features of SOAP typically include: 1. **Read Alignment:** Tools to align short reads (short oligonucleotides) from sequencing experiments to reference genomes or sequences.
TopHat is a bioinformatics software tool used primarily for aligning RNA-Seq reads to a reference genome. It is designed to handle the unique challenges posed by RNA sequencing data, particularly the splicing of eukaryotic genes. Key features of TopHat include: 1. **Detection of Splicing Events**: TopHat identifies exon-exon junctions in RNA-Seq data, which is essential for mapping reads that span across splice junctions where introns are excised.
The ViennaRNA Package is a widely used software suite for the prediction and analysis of RNA secondary structures. It is particularly useful in computational biology and bioinformatics for researchers studying RNA sequences, as it provides tools to predict how RNA folds and to analyze various structural features. Key features of the ViennaRNA Package include: 1. **RNA Secondary Structure Prediction**: It includes algorithms that predict the most stable secondary structure of an RNA sequence based on thermodynamic models.
The "Z Curve" can refer to several concepts depending on the context in which it is used. Here are a few interpretations: 1. **Statistical Z-curve**: In statistics, a Z-curve can refer to the standard normal distribution curve, which is a bell-shaped curve that represents the distribution of z-scores. A z-score indicates how many standard deviations an element is from the mean, and the Z-curve provides a visual representation of this distribution.
A checksum is a value used to verify the integrity of a data set. It is typically calculated by applying a specific algorithm to a block of data and producing a fixed-size string of characters, which can be in the form of a number or a sequence of hexadecimal digits. The primary purpose of a checksum is to detect errors that may have occurred during data transmission or storage.
MD5, which stands for Message-Digest Algorithm 5, is a widely used cryptographic hash function that produces a 128-bit (16-byte) hash value. It is commonly expressed as a 32-character hexadecimal number.
Geometric algorithms are a subset of algorithms in computer science and computational geometry that deal with the study and manipulation of geometric objects and their properties. These algorithms are designed to solve problems that involve geometric shapes, points, lines, polygons, and higher-dimensional objects. They are widely used in various fields, including computer graphics, robotics, geographic information systems (GIS), motion planning, and computer-aided design (CAD).
The Boltzmann sampler is a probabilistic method used to generate samples from a distribution that is governed by the Boltzmann distribution (or Gibbs distribution). In statistical mechanics, the Boltzmann distribution describes the probability of a system being in a certain state based on its energy and the temperature of the system.
The term "reverse-search algorithm" can refer to different concepts in different contexts, but it often relates to search methods or strategies that are applied in various fields such as computer science, data structures, and graph theory. Below are some interpretations of what a reverse-search algorithm might involve: 1. **Graph Search Algorithms**: In graph theory, reverse-search may refer to algorithms that explore a graph from a target node back to the start node.
The Tompkins-Paige algorithm is an algorithm used in the field of computer science, particularly in the domain of automated theorem proving and logic programming. It is primarily used for the resolution of logical formulas. The algorithm focuses on the resolution principle, which is a fundamental method in propositional and first-order logic. It allows for the derivation of conclusions from premises using a process called resolution, which involves combining clauses to produce new clauses.
Geohash-36 is a variant of the Geohash encoding system, which is a method for encoding geographic coordinates (latitude and longitude) into a single string of characters. The traditional Geohash system uses a base-32 encoding scheme, utilizing 32 characters (which typically include letters and numbers) to represent the geographic area.
The Nielsen transformation is a mathematical procedure used primarily in the field of algebraic topology and related areas such as functional analysis. Specifically, it concerns the transformation of topological spaces and continuous mappings. One of the most common contexts in which the Nielsen transformation is discussed is in relation to Nielsen fixed point theory. This is a branch of mathematics that studies the number and properties of fixed points of continuous functions. The Nielsen transformation provides a way to systematically analyze and modify continuous maps while preserving their topological properties.
The Higher Residuality Problem, often referred to simply as "higher residuosity," is a concept in number theory and algebraic geometry that deals with the distribution of prime residues in modular arithmetic. Although there may not be a well-defined term widely recognized specifically as "Higher Residuosity Problem," the concept can be explored through related areas. In general, the residuosity problem examines whether certain numbers can be represented as residues modulo a prime or composite number.
The "Table of costs of operations in elliptic curves" typically refers to a comparative analysis of the computational costs associated with various operations when working with elliptic curves in cryptographic contexts. These costs can vary based on number representation (e.g., binary or affine coordinates), the underlying field (prime or binary fields), and the specific algorithms used.
Cosmological simulation is a computational approach used in astrophysics and cosmology to model the large-scale structure of the universe and the formation and evolution of cosmic structures over time. These simulations utilize the laws of physics, particularly the principles of general relativity, hydrodynamics, and particle physics, to predict how matter, energy, and forces interact on cosmological scales.
A **ringed topos** is a concept from the field of topos theory, which is a branch of category theory that generalizes set theory and provides a framework for discussing various mathematical structures. In topos theory, a "topos" (plural: "topoi") is a category that behaves like the category of sets and has certain properties that make it suitable for doing mathematics in a categorical context.
BigDFT is a software package designed for performing large-scale density functional theory (DFT) calculations in computational materials science and chemistry. It is particularly focused on providing high-throughput DFT capabilities, allowing researchers to efficiently study and simulate complex systems with large numbers of atoms.

Pinned article: Introduction to the OurBigBook Project

Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
We have two killer features:
  1. topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculus
    Articles of different users are sorted by upvote within each article page. This feature is a bit like:
    • a Wikipedia where each user can have their own version of each article
    • a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
    This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
    Figure 1.
    Screenshot of the "Derivative" topic page
    . View it live at: ourbigbook.com/go/topic/derivative
  2. local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:
    This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
    Figure 5. . You can also edit articles on the Web editor without installing anything locally.
    Video 3.
    Edit locally and publish demo
    . Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    Descendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact