The protests against SOPA (Stop Online Piracy Act) and PIPA (Protect IP Act) were significant events that took place in early 2012 in response to proposed legislation in the United States aimed at combating online copyright infringement. **Background:** - **SOPA:** Introduced in the House of Representatives, SOPA aimed to give copyright holders the ability to take down infringing content and block access to foreign websites that hosted or linked to pirated content.

CD90, also known as Thymocyte Differentiation Antigen 1 (Thy-1), is a cell surface glycoprotein that is primarily expressed on T cells, but it can also be found on neurons, fibroblasts, and several other cell types. It is involved in a variety of biological processes, including cell adhesion, signaling, and immune response regulation.

Carbon-13 nuclear magnetic resonance (¹³C NMR) is a type of nuclear magnetic resonance spectroscopy that specifically targets the carbon-13 isotope of carbon. In this technique, the magnetic properties of carbon-13 nuclei, which have a nuclear spin of 1/2, are utilized to provide information about the structure, dynamics, and environment of carbon-containing compounds.

A Card Verifiable Certificate (CVC) is a type of digital certificate designed to provide a secure and verifiable method for authenticating the identity of individuals, particularly in relation to payment cards or identity cards. CVCs are commonly used in the context of EMV (Europay, MasterCard, and Visa) standards, which govern secure chip card transactions.

Hausdorff density is a concept used in measure theory and geometric measure theory, particularly in the study of sets in Euclidean space or more general metric spaces. It offers a way to evaluate the "size" of a set, particularly when classical notions of measure (like Lebesgue measure) may not apply or are insufficient.

The Yukawa interaction, named after the Japanese physicist Hideki Yukawa, is a fundamental interaction responsible for the force between nucleons (protons and neutrons) in atomic nuclei. It was proposed in the context of particle physics and is a type of scalar interaction. Here are the key points about Yukawa interactions: 1. **Mediated by Mesons**: Yukawa proposed that the strong nuclear force between nucleons is mediated by the exchange of particles known as mesons.

Carrie Anne Philbin is a prominent figure in the realm of education and technology, particularly known for her work in promoting computer science and digital literacy. She is a passionate advocate for teaching coding and robotics to students and has been involved in various initiatives aimed at making computer science more accessible. Philbin is also recognized for her contributions to the development of educational resources and often engages with the community through talks, workshops, and online platforms.

The term "Euler sequence" can refer to different concepts depending on the context, but one of the most common uses is related to the Euler numbers or the sequence of Euler's totient function. 1. **Euler Numbers**: In combinatorial mathematics, Euler numbers (not to be confused with Eulerian numbers) are a sequence of integers that occur in the expansion of certain generating functions. They can be defined recursively and are used in various areas of mathematics, such as topology and number theory.

The concept of the "line at infinity" arises primarily in projective geometry, a branch of mathematics that extends the properties of Euclidean geometry. In projective geometry, we can consider points and lines at infinity, which help to simplify and unify various geometric theorems and properties. ### Definition of Line at Infinity: 1. **Homogeneous Coordinates**: In projective geometry, points in the plane are represented using homogeneous coordinates.

Uti possidetis juris is a legal principle originating from Roman law, which translates to "as you possess under law." It is primarily used in the context of territorial disputes and refers to the idea that the borders of newly independent states should reflect the administrative boundaries that existed at the time of their independence. The principle has been particularly significant in post-colonial contexts, where it has been applied to maintain stability and order in the boundaries of states that emerged after the decolonization process.

Human presence in space refers to human activities, exploration, and habitation beyond Earth’s atmosphere. This includes a wide range of activities and achievements, from early space flights to current operations on the International Space Station (ISS) and future plans for lunar and Martian exploration. Here are some key aspects: 1. **Crewed Space Missions**: Human spaceflight began with missions like Vostok 1 in 1961, which carried Yuri Gagarin, the first human in space.

AllegroGraph is a graph database and framework for storing, querying, and analyzing large datasets represented as graphs. Developed by Franz Inc., it is designed to manage complex relationships within datasets, making it well-suited for applications that require rich data interconnectivity, such as semantic web applications, knowledge graphs, and linked data.

Graph products are operations that combine two or more graphs to create a new graph, and these products can capture different structural relationships between the original graphs. There are several types of graph products, each with its own definition and properties.

A Simplex graph is related to the concept of simplices in geometry and topology. In mathematical terms, a simplex is the generalization of the notion of a triangle or tetrahedron to arbitrary dimensions. For example: - A 0-simplex is a single point. - A 1-simplex is a line segment connecting two points. - A 2-simplex is a triangle, defined by three points. - A 3-simplex is a tetrahedron, defined by four points.

A factor graph is a type of bipartite graph used in statistics, probability, and machine learning to represent the factorization of a probability distribution. It provides a visual and structural way to denote how variables and factors (functions that define relationships between variables) are interconnected. ### Key Components: 1. **Variables**: These are typically represented as nodes on one side of the graph. Each variable can be a random variable in a probabilistic model.

Implicit blockmodeling is a method used in social network analysis for classifying and clustering individuals or nodes in a network based on their patterns of connections or interactions, without requiring a predefined model structure. It is often utilized in the study of social structures, where the relationships between individuals can be complex and not easily described by direct measures. In implicit blockmodeling, the goal is to identify "blocks" or clusters of nodes that exhibit similar connectivity patterns.

The Squeeze Theorem, also known as the Sandwich Theorem or Pinching Theorem, is a fundamental concept in calculus, specifically in the context of limits. It helps to determine the limit of a function by comparing it with two other functions that "squeeze" it in a defined manner.

Hadamard's method of descent, developed by the French mathematician Jacques Hadamard, is a technique used in the context of complex analysis and number theory, particularly for studying the growth and distribution of solutions to certain problems, such as Diophantine equations and modular forms. The method relies on the concept of reducing a problem in higher dimensions to a problem in lower dimensions (hence the term "descent").

The lower convex envelope, often referred to as the convex hull of a set of points, is a fundamental concept in computational geometry and optimization. It essentially represents the smallest convex shape that can encompass a given set of points or an entire function. For a set of points in a Euclidean space, the lower convex envelope is the boundary of the convex hull that lies below the given points.

Mixed boundary conditions refer to a type of boundary condition used in the context of partial differential equations (PDEs), where different types of conditions are applied to different parts of the boundary of the domain. Specifically, a mixed boundary condition can involve both Dirichlet and Neumann conditions, or other types of conditions, imposed on different sections of the boundary.