node

Examples of node in the following topics:

• Electrical Events

  • The heart's activity is dependent on the electrical impulses from the sinoatrial (SA) node, and the atrioventricular (AV) node, which form the intrinsic conduction system of the heart.
  • The SA node is a bundle of nerve cells located on the outer layer of the right atria.
  • The SA node impulses also travel to the AV node, which stimulates ventricular contraction.
  • The AV node slows the neural impulse from the SA node by a slight amount, which causes a delay between depolarization of the atria and the ventricles.
  • The normal firing rate in the AV node is lower compared to the SA node because it slows the rate of neural impulses.

• Lymph Nodes

  • Lymph nodes are found throughout the body, and are typically 1-2 cm long.
  • Each lymph node has an afferent lymph vessel, which directs lymph into the node, and an efferent lymph vessel, which directs lymph out of the node at the concave side of the node, known as the hilum.
  • The hilium also contains the blood supply of the lymph node.
  • Lymphadenopathy describes the condition when lymph nodes are swollen.
  • The changes observed in lymph nodes have clinical significance.

• Lymph Transport

  • Lymph circulates to the lymph node via afferent lymphatic vessels and drains into the lymph node in the subcapsular sinus.
  • Lymph circulates to the lymph node via afferent lymphatic vessels.
  • The lymph fluid drains into the node just beneath the capsule of the node into the various sinus spaces of the lymph node.
  • The sinuses converge at the hilum of the node, and lymph then leaves the lymph node via an efferent lymphatic vessel towards either a more central lymph node or towards a lymph duct for drainage into one of the subclavian veins.
  • The lymph flows from the afferent vessels into the sinuses of the lymph node, and then out of the node through the efferent vessels.

• Electric Activity in the Heart

  • The sinoatrial node (also commonly spelled sinuatrial node) is the impulse-generating (pacemaker) tissue located in the right atrium of the heart: i.e., generator of normal sinus rhythm.
  • The sinoatrial node (also commonly spelled sinuatrial node, abbreviated SA node) is the impulse-generating (pacemaker) tissue located in the right atrium of the heart, and thus the generator of normal sinus rhythm.
  • These cells form the atrioventricular node (AV node), which is an area between the atria and ventricles, within the atrial septum.
  • If the AV node also fails, Purkinje fibers are capable of acting as the pacemaker.
  • High magnification micrograph of sinoatrial node tissue and an adjacent nerve fiber.

• Node attributes

  • But, generally, a k-core is a set of nodes that are more closely connected to one another than they are to nodes in other k-cores.
  • Figure 4.3 shows four sub-groups, which are colored to identify which nodes are members of which group (the "West" group and the "WRO" group each contain only a single node).
  • Differences of amount: Figure 4.3 also uses the size of the nodes (Properties>nodes>size>attribute-based) to display an index of the number of nodes in each group.
  • This difference of amount among the nodes is best indicated, visually, by assigning the size of the node to values of some attribute.
  • Once these quantities are computed, they can be added to NetDraw (Transform>node attribute editor>edit>add column), and then added to the graph (Properties>nodes>size>attribute-based).

• Location, location, location

  • Where a node or a relation is drawn in the space is essentially arbitrary -- the full information about the network is contained in its list of nodes and relations.
  • Circle graphs are commonly used to visualize which nodes are most highly connected.
  • The nodes are located at equal distances around a circle, and nodes that are highly connected are very easy to quickly locate (e.g.
  • There are many reasonable definitions of what it means for two nodes to be "similar. " In this example, two nodes are "similar" to the extent that they have similar shortest paths (geodesic distances) to all other nodes.
  • "West" and "Educ" have very different patterns of ties to the other nodes.

• Highlighting parts of the network

  • Nodes that aren't connected are called "isolates. " Some nodes may be connected to the network by a single tie.
  • The geodesic distance between two nodes is the length of the shortest path between them.
  • The resulting graphic is one way of understanding which nodes are most similar to one another, and how the nodes may be classified into "types" based on their patterns of connection to other nodes.
  • Points are colored, and the information about which nodes fall in which partitions (i.e. which cases are in which factions) is saved to the node attributes database.Analysis>Subgroups>Newman-Girvan.
  • The network formed by selecting a node, including all actors that are connected to that node, and all the connections among those other actors is called the "ego network" or (1-step) neighborhood of an actor.

• Applying the Decision Tree

  • Decision nodes: These are commonly represented by squares.
  • Chance nodes: These may be represented by circles.
  • End nodes: These may be represented by triangles.
  • An end node is where a decision is made and its value or utility is identified.
  • The next three nodes would then read: "Report colleague to superiors," "Confront colleague," and "Ignore situation. " Each of these nodes would then have a "Yes" arrow and a "No" arrow.

• Blocks and cut-points

  • An alternative approach to finding the key "weak" spots in the graph is to ask: if a node were removed, would the structure become divided into un-connected parts?
  • If there are such nodes, they are called "cutpoints. " And, one can imagine that such cutpoints may be particularly important actors -- who may act as brokers among otherwise disconnected groups.
  • That is, we try to find the nodes that connects the graph (if there are any).
  • This means that if EDUC (node 3) were removed, the WRO would become isolated.
  • Node 3, then, is a cut-point.

• Lymphogranuloma Venereum

  • Lymphogranuloma venereum (LGV) is a sexually transmitted disease which causes an infection of the lymph nodes.
  • LGV is an infection of the lymph nodes.
  • The infectious agent spreads to the lymph nodes through the lymphatic drainage pathways, causing inflammation of the lymph nodes and lymphatic channels.
  • The enlarged lymph nodes are called buboes and are painful, inflamed and can fixate to the skin.