Ring Definition and 1000 Threads

In molecular biology, a RING (Really Interesting New Gene) finger domain is a protein structural domain of zinc finger type which contains a C3HC4 amino acid motif which binds two zinc cations (seven cysteines and one histidine arranged non-consecutively). This protein domain contains 40 to 60 amino acids. Many proteins containing a RING finger play a key role in the ubiquitination pathway.

View More On Wikipedia.org
Recent contents Top users
  1. S

    What Are the Automorphisms of Z[x]?

    Question: What are the automorphisms of Z[x]? I know there are two automorphisms, one of which is the identity map, ø(f(x)) = f(x). What is the other one? ø(f(x)) = -f(x) for all f(x) in Z[x]? Or does it have something to do with the degree or factorization of the polynomials? Please...
  2. S

    Electrodynamics for a rotating ring

    Homework Statement A thin copper (resistivity 1.7 x 10-8 Ωm, density 8.9 g/cm3) ring rotates about an axis perpendicular to a uniform magnetic field B0. Its initial frequency of rotation is ω0. Calculate the time it takes the frequency to decrease to 1/e of its initial value, under the...
  3. A

    Find the period of oscillation of a little charged ring

    Homework Statement Find the period of oscillation, T, of a little charged ring that is free to move along a vertical wire when placed equi-distant between two like charges above and below it. Small displacement only. Treat the “little” ring like a point charge and use the binomial expansion...
  4. F

    MHB Integral Ring Theory: Proving Integral Extension Property for Quotient Rings

    Let $S$ be a commutative ring and $R$ a sub-ring. Let $J$ be an ideal of $S$ and $I$ be the intersection of $J$ and $R$. Show that if $S$ is integral over $R$, then $S/J$ is integral over $R/I$. My attempt: Let $x+J$ be in $S/J$. Then $x$ is integral over $R$ so there is a monic polynomial...
  5. T

    Conceptual doubt - Rotating nonconducting ring

    Homework Statement Consider a non conducting ring of radius r and mass m which has a total charge q distributed uniformly on it.The ring is rotated about its axis with an angular speed ω. a)Find the equivalent electric current in the circuit. b)Find the magnetic moment μ of the ring...
  6. F

    MHB How can you simplify generated ideals in a commutative unital ring?

    Let $x,y$ be members of a commutative unital ring. By using various 'rules' show that $<y^4+3x^3-2x^2,7y^4+5(xy+yx^2),x^3+2y^3>+<x^3,xy^2,xy^3,yx^2,xy^2,y^4$> $=<x^2,xy,y^3>$, where $<.>$ denotes the ideal generated by$.$ Can you tell me the rules for simplyifing these generated ideals (and I...
  7. Radarithm

    K&K Question 3.22 - Mass, String, and Ring

    Homework Statement A mass m whirls around on a string which passes through a ring, as shown. Neglect gravity. Initially the mass is distance r0 from the center and is revolving at angular velocity ω0. The string is pulled with constant velocity V starting at t = 0 so that the radial distance...
  8. KiNGGeexD

    Electrostatic potential of a circular ring

    I'm a little stumped with this problem, I have posted a photograph below as there is a diagram to compliment the questionExpressions which I used where V(r)= k q/r Where q= σ da Where da is an element of area And k= 1/4πεI messed around with these expressions for a while but it didn't really...
  9. Saitama

    Frequency of Circular Motion in Ring Rolling Inside a Cone

    Homework Statement (See attachment) Assume that the surface has friction and a small ring of radius ##r## rolls on the surface without slipping. Assume conditions have been set up so that (1) point of contact between the ring and the cone moves in a circle at height ##h## above the tip...
  10. evinda

    MHB Find all the zero divisors in a ring

    Hello! :D I am given the following exercise:Find all the zero divisors in the ring $\mathbb{Z}_{20}$. For each zero divisor $[a]$,find an element $[b] \neq [0]$ such that $[a][b]=[0]$. That's what I did..Could you tell me if it is right?? Zero divisors at the ring $\mathbb{Z}_{20}$: $\{ [2]...
  11. evinda

    MHB Finding the Units of the Ring $R=\mathbb{Z}[w]$

    Hello! :D I am given the following exercise and I have some questions :o Calculate the units of $R=\mathbb{Z}[w]=\{ a+bw, a,b \in \mathbb{Z}\} , w=\frac{-1+i \sqrt{3}}{2}$. In my notes is the following solution: We remark that $w$ is a root of $x^2+x+1$ So, $w^2+w+1=0 \Rightarrow w^2=-w-1$...
  12. 1

    Is "Multiplication Commutative in Rings?

    Is (-x) * y = x * (-y) true for all rings? It seems simple enough but I feel like * must be commutative when trying to prove this.
  13. evinda

    MHB Do I Have to Show All Axioms to Prove a Set is a Ring?

    Hey again! :) I have a question.. If I have to show that a set $S$ is a ring,do I have to show all the axioms or is it enough to show the criteria: $s_1,s_2 \in S$ and $s_1-s_2 \in S$ $s_1 \cdot s_2 \in S$ ?
  14. N

    What is the acceleration of the ring on a vertical rod with a spring?

    Homework Statement A ring is moving on a vertical rod attached to a spring. Find the velocity of the ring when spring becomes horizontal. The spring is ideal with spring constant 400N/m. Mass of ring is 10kg. Natural length of spring is 4m. Initially the ring is at rest as shown in...
  15. Sudharaka

    MHB What Is the Annihilator of a Quotient Ring?

    Hi everyone, :) I think I need to refresh my memory about annihilators and quotient rings. Hope you can help me with the following example. I want to find the annihilator of $a'$ and $b'$ of the quotient ring $R=\mathbb{Z}/(a'b')$ where $a',\,b'>1$. So if I go by the definition...
  16. Math Amateur

    MHB Ring Theory texts and "right notation" for maps/functions

    I would like members views on right notation for maps/functions. I am thinking of studying some material in some of the chapters of the book: Introduction to Ring Theory by P. M. Cohn Cohn claims his book is suitable for 2nd and 3rd year undergraduates and the book seems to have some really...
  17. Sudharaka

    MHB Ring Epimorphism and Nil Radical

    Hi everyone, :) Here's a question that I failed to do correctly in an exam. I want to find the answer to this and understand it fully. Any comments, hints would be greatly appreciated. Question: If $\theta:\, R\rightarrow S$ is a ring epimorphism, prove that \(\theta(\mbox{Nil }(...
  18. L

    Charged ring, integrate for electric potential

    Homework Statement A flat ring of inner radius R1 and outer radius R2 carries a uniform surface charge density σ. Determine the electric potential at points along the axis (the x axis). [Hint: Try substituting variables.] Homework Equations V = (kQ)/r The Attempt at a Solution...
  19. T

    Calculating Flux Through a Circular Ring

    Homework Statement A particle having charge q = 8.85 μC is placed on the axis of a circular ring of radius R = 30 cm. Distance of the particle from centre of the ring is a = 40 cm. Calculate electrical flux passing through the ring. Homework Equations Flux through a surface = ∫E.ds...
  20. E

    FPGA-Based System Design with Multiplexed Ring Oscillators

    Hello Sir, I am PG scholar in VLSI design.I am doing my project on FPGA based system in that i have to used ring oscillator.From number oscillator i need to choose two oscillator based on multiplexer.Can anyone tell me how it is?
  21. L

    Question about the E-field along center axis of charged ring

    http://www.physics.udel.edu/~watson/phys208/exercises/kevan/efield1.html I'm having trouble understanding the derivative notation. I know that "dE" and dQ" have to do with the derivative, but what exactly does that mean in the context of this problem? For some reason I find it difficult to...
  22. P

    Ring of charge electric potential

    Homework Statement The ring is in the z,y plane. D = 2m R = 4m Q = 8 * 10^-6 C X = distance to the edge λ = dQ/dX dX = rdθ dQ = infinitely small charge dX = infinitely small arc of ring What is the potential difference at the point D perpendicular to the centre of the ring? Homework Equations...
  23. Mordred

    Saturn's north pole hexagon vortex ring

    New photo released today from NASA showing remarkable detail of a hexagon vortex ring at Saturn's North pole. http://www.space.com/24534-saturn-hexagon-vortex-nasa-cassini-photo.html Anyone see any papers explaining how the ring gets its shape?
  24. tipu_sultan

    What is role of Quad Ring Main Unit (QRM) in Substation?

    Below is the typical diagram of a Substation in which MIL and MIR are with TR-1 and TR-2 respectively. Where TR-1 and TR-2 are the transformers whose function is to step down the voltage. I have also confusion about the flow(path) of the electricity with in substation. The confusion is that...
  25. Math Amateur

    MHB Localization in Commutative Ring Theory

    I am reading Watson: Topics in Commutative Ring Theory. in Ch 3: Localization, Watson defines the quotient field of an integral domain as follows: -------------------------------------------------------------------------------------------------- We begin by defining an equivalence relation on...
  26. A

    Inserted mass on a rotating ring, problem with solution interpretation

    Homework Statement Its about a system like in picture. I have it solved alredy BUT I still have a problem After getting the dynamic equation by Newtonian and Lagrangian methods I solved one of them making the hipótesis of Little oscillations. This diferential equation has three solutions...
  27. U

    Force on small wire segment in ring

    Homework Statement Part (a): Describe what happens to current when ring contracts Part(b): Find how much energy is stored, changing per unit time and rate of mechanical work being done Part (c): Show the pressure is given by: Part (d): Why is the force on a small wire segment not BIL...
  28. Math Amateur

    MHB Ideals of a Residue Class Ring- Ring Isomorphism

    I am reading R. Y. Sharp: Steps in Commutative Algebra. In Chapter 2: Ideals on page 32 we find Exercise 2.40 which reads as follows: ----------------------------------------------------------------------------------------------- Let I, J be ideals of the commutative ring R such that I...
  29. N

    Understanding Rotor RMF in Squirrel Cage & Slip Ring Induction Motors

    is the rotor rotating magnetic field(R-RMF) present in squirrel cage induction motor (SCIM). Is it same as in 3 phase ROTOR winding of slip ring induction motor (SRIM), generating rotor RMF. * THE 3 phase, supply given to stator 3 phase winding of SRIM, generates (RMF), which cuts the rotor 3...
  30. B

    What Is the Coefficient of Static Friction Between the Ring and the Shaft?

    Homework Statement The 5-kg cylinder is suspended from two equal length cords. The end of each cord is attached to a ring of negligible mass that passes along a horizontal shaft. If the rings can be separated by the greatest distance d= 400 mm and still support the cylinder, determine the the...
  31. P

    Point loading for a circular ring -- Stress calculation

    I need to find a suitable mathematical method of calculating the stresses at multiple points of a circular ring subjected to point loading. I'll calculate the rest myself- any suggestions?
  32. Y

    Calculating the Electric field at a point due to a ring of charge

    I don't know if this is the correct section. It is not exactly a homework problem, but here it is: If I were given a circle of charge with radius r and were asked to find the electric field due to this circle of charge at the center of the circle, would it be valid to do the following...
  33. Math Amateur

    MHB Structure of R[X] and an exercise on ring adjunction

    I am reading R.Y. Sharp's book "Steps in Commutative Algebra" At the moment I am trying to achieve a full understanding of the mechanics and nature of LEMMA 1.11 and am reflecting on Exercise 1.12 which follows it. LEMMA 1.11 reads as follows: (see attachment)...
  34. Math Amateur

    MHB Quasi-local commutative ring with maximal ideal M

    I am reading R.Y. Sharp: Steps in Commutative Algebra. In Chapter 3: Prime Ideals and Maximal Ideals, Exercise 3.19 reads as follows: Let R be a quasi-local commutative ring with maximal ideal M. Show that the ring R[[X_1, ... \ ... , X_n]] of formal power series in indeterminates X_1, ...
  35. Astrum

    How Does Angular Velocity Change When a Mass on a String is Pulled Inward?

    Homework Statement A mass ##m## whirls around on a string which passes through a ring. Neglect gravity. Initially the mass is at distance ##r_0## from the center and is revolving at angular velocity ##\omega _0##. The string is pulled with constant velocity ##v## starting at ##t=0## so that...
  36. R

    Potential and field of a thing circular ring

    Homework Statement I'm trying to work through an example in my classical mechanics textbook (Fowles and Cassiday, 7th ed, example 6.7.2. The problem I am having is when he expands the integrand into a power series. I'll write out the first part of the solution. The question is "find the...
  37. S

    MHB Can You Find a Counterexample for This Module Over a Commutative Ring?

    Hi, Let $A$ be a commutative ring, $M$ an $A-$module and $U,V,V'$ submodules of $M$ such that $U \cap V = U \cap V'$ and $U+V=U+V'$. Does it follow that $V=V'$? The answer is no because the condition that $V \subset V'$ is necessary though I can't find a counterexample. Does someone has a...
  38. S

    Quantity of zeros on a ring - Complex Analysis

    Determine the quantitiy of zeroes of the function: f(z)=z^{4}-8z+10 a) Inside the circle | z | < 1 b) Inside the ring 1 \leq | z | < 2a) f(z)=(z^{4}-8z)+10=g(z)+h(z) As |h(z)| \geq |g(z)| \forall z : | z | = 1 Then by Rouche's Theorem the number of zeros of the function inside the circle is the...
  39. E

    How much further does a ring roll up a hill

    Homework Statement http://puu.sh/5nLnI.png Homework Equations I = mr2 The Attempt at a Solution Moment of inertia: Mass density = mass / area = 2.59 / (π*9.52 - π*7.52) = 0.02424772368 kg / cm2I = (areaA)(density)(radiusA) - (areaB)(density)(radiusB) =...
  40. R

    How to find the mass (or volume) of Saturn's ring?

    Homework Statement Saturn has the largest ring system of any planet, with the inner edge about 7000 km above Saturn’s surface and extending to its outer edge about 80,000 km above the surface. However, the rings are only about 20 m thick. The rings are made of billions of small particles, most...
  41. Mandelbroth

    Ring of Polynomials and Ring of Polynomial Functions

    Recently, I've developed a habit of trying to separate the idea of a function from the idea of the image of the function. This has mostly just confused me, but I am adamant about sticking to it. I think the two terms, "ring of polynomials" and "ring of polynomial functions," are not...
  42. S

    Emf induced in a conducting ring.

    Consider a magnetic field perpendicular to a conducting ring moving with a velocity, v.When the ring is moving on the ground in translational motion alone, will emf be induced? I am slightly confused because if you consider the two halves of the ring as two rods, emf will be induced in both of...
  43. N

    Magnetic flux through triangular ring

    Homework Statement Very long wire carrying current I is surrounded by a brass ring of a triangular cross section. (figure attached) Show that ψ = μ° I h ------ (b - a ln ((a+b)/b) 2∏b Homework Equations A = (μ°I/2∏ * ln x) az (according to one of the solutions, where x is the...
  44. R

    Optics Newton’s ring apparatus Problem

    Homework Statement Here is a worked problem: I don't see why they've used "m-1/2" instead of "m+1/2"?Homework Equations According to my textbook the radius of mth bright fringe is: ##x = ((m+\frac{1}{2})\lambda R)^{1/2}## Where R is the radius of curvature of the convex lens.The Attempt...
  45. K

    Work done by rotating a ring in a magnetic field.

    Homework Statement Our teacher isn't very descriptive: A ring of radius "a" and resistance "R" is placed at the center of a long solenoid with "n" turns (assume the solenoid is longer and wider than the ring) with its axis lined up with that of the solenoid. Find the amount of work done to...
  46. C

    MHB Prove $R\ncong R\left[x\right]$ for Noetherian Ring

    Let $R$ be a commutative Noetherian ring with identity. Prove that $R\ncong R\left[x\right]$ and give an example that the result is not true if $R$ is not Noetherian.
  47. S

    Torque and Moment of Inertia of a black ring

    Homework Statement A black ring is placed concentrically on a turntable and is being pulled by a constant force of 12.5 N and the force is applied at a distance of .01m from the spindle/pulley. It's known that the ring accounts for about 8.50% of the total moment of inertia. Find moment of...
  48. O

    Find acceleration due to large planar ring

    Homework Statement Firstly, my beautiful picture: http://imgur.com/WZTl3rr A ship has encountered a massive planar ring in space. The ring has radius R=1km and mass M=1.0 * 1018. Calculate the force per unit mass on the Enterprise assuming the starship is located at a point on the plane of...
  49. Sudharaka

    MHB Eigenvalues and Eigenvectors over a Polynomial Ring

    Hi everyone, :) Here's another question that I solved. Let me know if you see any mistakes or if you have any other comments. Thanks very much. :) Problem: Prove that the eigenvector \(v\) of \(f:V\rightarrow V\) over a field \(F\), with eigenvalue \(\lambda\), is an eigenvector of \(P(f)\)...
  50. marellasunny

    Epicyclic gear:modules for the sun,planet and ring gear

    Is the module(M) of the sun,planet and ring gear in a 'planetary gear set' equal to each other always? Is it possible for M to be different for each of the gears in the set?[-Applications of this?] $$PCD_{Ring}=PCD_{Sun}+2*PCD_{Planet}\Rightarrow N_{Ring}=N_{Sun}+2*N_{Planet}$$ is valid only...
Back
Top