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Energy Manifold Natural Gradient Descent: From Riemannian Optimization to Modern Neuroscience, NeuroAI and Quantum Physics

Dr. Rishabh Pathak
When Geometry, Energy, Artificial Intelligence and Neuroscience Converge Modern Artificial Intelligence is rapidly moving beyond the idea that learning simply means minimizing an error function. Increasingly, researchers are asking a deeper question: what is the structure of the space in which learning takes place? This question becomes particularly important when the system being modelled is constrained, nonlinear, dynamic, or governed by physical principles. A recent work titled “Energy Manifold Natural Gradient Descent: Riemannian Optimization for Neural PDE Solvers” , by Zhangyong Liang and Huanhuan Gao, introduces Energy Manifold Natural Gradient Descent (EMNGD) , a mathematical framework that extends energy-based natural-gradient optimization from unconstrained Euclidean parameter spaces to constrained Riemannian parameter manifolds . At its core, the framework proposes a simple but powerful principle: An optimization algorithm should not only determine how to reduce error; it sh...
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Concentric Muscles Actions

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Dr. Rishabh Pathak

Concentric muscle actions refer to a type of muscle contraction where the muscle shortens as it generates force to overcome a resistance and produce joint movement. During concentric contractions, the muscle fibers contract and pull on the attached bones, resulting in the movement of body segments. Here are key points regarding concentric muscle actions:

Characteristics of Concentric Muscle Actions:

1.    Muscle Shortening:

o    During concentric contractions, the muscle fibers actively shorten as they contract, pulling the insertion point closer to the origin point.

o    This shortening of muscle fibers results in the movement of bones and joints, leading to the desired action, such as flexion or extension.

2.    Force Generation:

o    Concentric contractions involve the generation of force by the muscle to overcome an external resistance and produce movement.

o    The muscle contracts concentrically to lift, push, or pull objects, creating tension and generating mechanical work.

3.    Joint Movement:

o    Concentric muscle actions are responsible for producing joint movements in various planes of motion, including flexion, extension, abduction, adduction, and rotation.

o    The shortening of muscle fibers leads to the movement of body segments and the execution of functional tasks.

4.    Power Production:

o    Concentric contractions are associated with the production of power and the generation of force over a specific range of motion.

o    Muscles contract concentrically to accelerate body segments, perform explosive movements, and generate dynamic force output.

5.    Acceleration Phase:

o    Concentric muscle actions are typically observed during the acceleration phase of movement, where the muscle shortens to initiate and propel the body segment.

o    The concentric contraction of agonist muscles is essential for overcoming inertia and accelerating the body in the desired direction.

6.    Energy Expenditure:

o    Concentric contractions require energy expenditure by the muscle fibers to generate force and perform mechanical work.

o    The metabolic demands of concentric actions involve the conversion of chemical energy into mechanical energy to produce movement.

7.    Strength Training:

o    Concentric exercises are commonly used in strength training programs to target specific muscle groups, improve muscle strength, and enhance functional performance.

o    Resistance training involving concentric contractions helps individuals develop muscle hypertrophy, increase force production, and enhance muscular endurance.

8.    Functional Applications:

o    Concentric muscle actions are essential for performing everyday activities, sports movements, and dynamic tasks that involve lifting, pushing, pulling, and accelerating body segments.

o    Functional movements such as walking, running, jumping, and throwing rely on the coordinated activation of muscles in concentric contractions.

9.    Controlled Eccentric Phase:

o    Following a concentric contraction, muscles often undergo an eccentric phase where they lengthen under tension to control the movement and decelerate the body segment.

o    The eccentric phase acts as a braking mechanism to prevent rapid joint acceleration and protect against excessive muscle strain.

Concentric muscle actions play a vital role in generating movement, producing force, and facilitating dynamic activities that require muscle shortening and joint motion. Understanding the mechanics of concentric contractions is essential for optimizing performance, enhancing strength, and promoting efficient movement patterns in various functional contexts.

 

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