Muscle contraction is the activation of tension-generating sites within muscle cells. In physiology, muscle contraction does not necessarily mean muscle shortening because muscle tension can be produced without changes in muscle length, such as when holding something heavy in the same position. The termination of muscle contraction is followed by muscle relaxation, which is a return of the muscle fibers to their low tension-generating state.

For the contractions to happen, the muscle cells must rely on the interaction of two types of filaments: thin and thick filaments.

The major constituent of thin filaments is a chain formed by helical coiling of two strands of actin, and thick filaments dominantly consist of chains of the motor-protein myosin. Together, these two filaments form myofibrils - the basic functional organelles in the skeletal muscle system.

In vertebrates, skeletal muscle contractions are neurogenic as they require synaptic input from motor neurons. A single motor neuron is able to innervate multiple muscle fibers, thereby causing the fibers to contract at the same time. Once innervated, the protein filaments within each skeletal muscle fiber slide past each other to produce a contraction, which is explained by the sliding filament theory. The contraction produced can be described as a twitch, summation, or tetanus, depending on the frequency of action potentials. In skeletal muscles, muscle tension is at its greatest when the muscle is stretched to an intermediate length as described by the length-tension relationship.

Unlike skeletal muscle, the contractions of smooth and cardiac muscles are myogenic (meaning that they are initiated by the smooth or heart muscle cells themselves instead of being stimulated by an outside event such as nerve stimulation), although they can be modulated by stimuli from the autonomic nervous system. The mechanisms of contraction in these muscle tissues are similar to those in skeletal muscle tissues.

Muscle contraction can also be described in terms of two variables: length and tension. In natural movements that underlie locomotor activity, muscle contractions are multifaceted as they are able to produce changes in length and tension in a time-varying manner. Therefore, neither length nor tension is likely to remain the same in skeletal muscles that contract during locomotion. Contractions can be described as isometric if the muscle tension changes but the muscle length remains the same. In contrast, a muscle contraction is described as isotonic if muscle tension remains the same throughout the contraction. If the muscle length shortens, the contraction is concentric; if the muscle length lengthens, the contraction is eccentric.

Types

Muscle contractions can be described based on two variables: force and length. Force itself can be differentiated as either tension or load. Muscle tension is the force exerted by the muscle on an object whereas a load is the force exerted by an object on the muscle. When muscle tension changes without any corresponding changes in muscle length, the muscle contraction is described as isometric. If the muscle length changes while muscle tension remains the same, then the muscle contraction is isotonic. In an isotonic contraction, the muscle length can either shorten to produce a concentric contraction or lengthen to produce an eccentric contraction. In natural movements that underlie locomotor activity, muscle contractions are multifaceted as they are able to produce changes in length and tension in a time-varying manner. Therefore, neither length nor tension is likely to remain constant when the muscle is active during locomotor activity.

Isometric contraction

An isometric contraction of a muscle generates tension without changing length. An example can be found when the muscles of the hand and forearm grip an object; the joints of the hand do not move, but muscles generate sufficient force to prevent the object from being dropped.

Isotonic contraction
In isotonic contraction, the tension in the muscle remains constant despite a change in muscle length. This occurs when a muscle's force of contraction matches the total load on the muscle.

Concentric contraction
In concentric contraction, muscle tension is sufficient to overcome the load, and the muscle shortens as it contracts. This occurs when the force generated by the muscle exceeds the load opposing its contraction.

During a concentric contraction, a muscle is stimulated to contract according to the sliding filament theory. This occurs throughout the length of the muscle, generating a force at the origin and insertion, causing the muscle to shorten and changing the angle of the joint. In relation to the elbow, a concentric contraction of the biceps would cause the arm to bend at the elbow as the hand moved from the leg to the shoulder (a biceps curl). A concentric contraction of the triceps would change the angle of the joint in the opposite direction, straightening the arm and moving the hand towards the leg.

Eccentric contraction

In eccentric contraction, the tension generated while isometric is insufficient to overcome the external load on the muscle and the muscle fibers lengthen as they contract. Rather than working to pull a joint in the direction of the muscle contraction, the muscle acts to decelerate the joint at the end of a movement or otherwise control the repositioning of a load. This can occur involuntarily (e.g., when attempting to move a weight too heavy for the muscle to lift) or voluntarily (e.g., when the muscle is 'smoothing out' a movement or resisting gravity such as during downhill walking). Over the short-term, strength training involving both eccentric and concentric contractions appear to increase muscular strength more than training with concentric contractions alone. However, exercise-induced muscle damage is also greater during lengthening contractions.

During an eccentric contraction of the biceps muscle, the elbow starts the movement while bent and then straightens as the hand moves away from the shoulder. During an eccentric contraction of the triceps muscle, the elbow starts the movement straight and then bends as the hand moves towards the shoulder. Desmin, titin, and other z-line proteins are involved in eccentric contractions, but their mechanism is poorly understood in comparison to cross-bridge cycling in concentric contractions.

Though the muscle is doing a negative amount of mechanical work, (work is being done on the muscle), chemical energy (of fat or glucose, or temporarily stored in ATP) is nevertheless consumed, although less than would be consumed during a concentric contraction of the same force. For example, one expends more energy going up a flight of stairs than going down the same flight.

Muscles undergoing heavy eccentric loading suffer greater damage when overloaded (such as during muscle building or strength training exercise) as compared to concentric loading. When eccentric contractions are used in weight training, they are normally called negatives. During a concentric contraction, contractile muscle myofilaments of myosin and actin slide past each other, pulling the Z-lines together. During an eccentric contraction, the myofilaments slide past each other the opposite way, though the actual movement of the myosin heads during an eccentric contraction is not known. Exercise featuring a heavy eccentric load can actually support a greater weight (muscles are approximately 40% stronger during eccentric contractions than during concentric contractions) and also results in greater muscular damage and delayed onset muscle soreness one to two days after training. Exercise that incorporates both eccentric and concentric muscular contractions (i.e., involving a strong contraction and a controlled lowering of the weight) can produce greater gains in strength than concentric contractions alone. While unaccustomed heavy eccentric contractions can easily lead to overtraining, moderate training may confer protection against injury.

Eccentric contractions in movement
Eccentric contractions normally occur as a braking force in opposition to a concentric contraction to protect joints from damage. During virtually any routine movement, eccentric contractions assist in keeping motions smooth, but can also slow rapid movements such as a punch or throw. Part of training for rapid movements such as pitching during baseball involves reducing eccentric braking allowing a greater power to be developed throughout the movement.

Eccentric contractions are being researched for their ability to speed rehabilitation of weak or injured tendons. Achilles tendinitis and patellar tendonitis (also known as jumper's knee or patellar tendonosis) have been shown to benefit from high-load eccentric contractions.

Vertebrate

In vertebrate animals, there are three types of muscle tissues: skeletal, smooth, and cardiac. Skeletal muscle constitutes the majority of muscle mass in the body and is responsible for locomotor activity. Smooth muscle forms blood vessels, gastrointestinal tract, and other areas in the body that produce sustained contractions. Cardiac muscle make up the heart, which pumps blood. Skeletal and cardiac muscles are called striated muscle because of their striped appearance under a microscope, which is due to the highly organized alternating pattern of A bands and I bands.

Skeletal muscle

Excluding reflexes, all skeletal muscles contractions occur as a result of signals originating in the brain. The brain sends electrochemical signals through the nervous system to the motor neuron that innervates several muscle fibers. In the case of some reflexes, the signal to contract can originate in the spinal cord through a feedback loop with the grey matter. Other actions such as locomotion, breathing, and chewing have a reflex aspect to them: the contractions can be initiated both consciously or unconsciously.

Neuromuscular junction

A neuromuscular junction is a chemical synapse formed by the contact between a motor neuron and a muscle fiber. It is the site in which a motor neuron transmits a signal to a muscle fiber to initiate muscle contraction. The sequence of events that results in the depolarization of the muscle fiber at the neuromuscular junction begins when an action potential is initiated in the cell body of a motor neuron, which is then propagated by saltatory conduction along its axon toward the neuromuscular junction. Once it reaches the terminal bouton, the action potential causes a  ion influx into the terminal by way of the voltage-gated calcium channels. The  influx causes synaptic vesicles containing the neurotransmitter acetylcholine to fuse with the plasma membrane, releasing acetylcholine into the synaptic cleft between the motor neuron terminal and the neuromuscular junction of the skeletal muscle fiber. Acetylcholine diffuses across the synapse and binds to and activates nicotinic acetylcholine receptors on the neuromuscular junction. Activation of the nicotinic receptor opens its intrinsic sodium/potassium channel, causing sodium to rush in and potassium to trickle out. As a result, the sarcolemma reverses polarity and its voltage quickly jumps from the resting membrane potential of -90mV to as high as +75mV as sodium enters. The membrane potential then becomes hyperpolarized when potassium exits and is then adjusted back to the resting membrane potential. This rapid fluctuation is called the end-plate potential The voltage-gated ion channels of the sarcolemma next to the end plate open in response to the end plate potential. They are sodium and potassium specific and only allow one through. This wave of ion movements creates the action potential that spreads from the motor end plate in all directions. If action potentials stop arriving, then acetylcholine ceases to be released from the terminal bouton. The remaining acetylcholine in the synaptic cleft is either degraded by active acetylcholine esterase or reabsorbed by the synaptic knob and none is left to replace the degraded acetylcholine.

Excitation–contraction coupling
Excitation–contraction coupling is the process by which a muscular action potential in the muscle fiber causes the myofibrils to contract. In skeletal muscle, excitation–contraction coupling relies on a direct coupling between key proteins, the sarcoplasmic reticulum (SR) calcium release channel (identified as the ryanodine receptor 1, RYR1) and voltage-gated L-type calcium channels (identified as dihydropyridine receptors, DHPRs). DHPRs are located on the sarcolemma (which includes the surface sarcolemma and the transverse tubules), while the RyRs reside across the SR membrane. The close apposition of a transverse tubule and two SR regions containing RyRs is described as a triad and is predominantly where excitation–contraction coupling takes place. Excitation–contraction coupling occurs when depolarization of skeletal muscle cell results in a muscle action potential, which spreads across the cell surface and into the muscle fiber's network of T-tubules, thereby depolarizing the inner portion of the muscle fiber. Depolarization of the inner portions activates dihydropyridine receptors in the terminal cisternae, which are in close proximity to ryanodine receptors in the adjacent sarcoplasmic reticulum. The activated dihydropyridine receptors physically interact with ryanodine receptors to activate them via foot processes (involving conformational changes that allosterically activates the ryanodine receptors). As the ryanodine receptors open,  is released from the sarcoplasmic reticulum into the local junctional space and diffuses into the bulk cytoplasm to cause a calcium spark. The sarcoplasmic reticulum has a large calcium buffering capacity partially due to a calcium-binding protein called calsequestrin. The near synchronous activation of thousands of calcium sparks by the action potential causes a cell-wide increase in calcium giving rise to the upstroke of the calcium transient. The  released into the cytosol binds to Troponin C by the actin filaments, to allow cross-bridge cycling, producing force and, in some situations, motion. The sarco/endoplasmic reticulum calcium-ATPase (SERCA) actively pumps  back into the sarcoplasmic reticulum. As  declines back to resting levels, the force declines and relaxation occurs.

Sliding filament theory

The sliding filament theory describes a process used by muscles to contract. It is a cycle of repetitive events that cause a thin filament to slide over a thick filament and generate tension in the muscle. It was independently developed by Andrew Huxley and Rolf Niedergerke and by Hugh Huxley and Jean Hanson in 1954. Physiologically, this contraction is not uniform across the sarcomere; the central position of the thick filaments becomes unstable and can shift during contraction but this is countered by the actions of the elastic myofilament of titin. This fine myofilament maintains uniform tension across the sarcomere by pulling the thick filament into a central position.

Cross-bridge cycle

Cross-bridge cycling is a sequence of molecular events that underlies the sliding filament theory. A cross-bridge is a myosin projection, consisting of two myosin heads, that extends from the thick filaments. Each myosin head has two binding sites: one for adenosine triphosphate (ATP) and another for actin. The binding of ATP to a myosin head detaches myosin from actin, thereby allowing myosin to bind to another actin molecule. Once attached, the ATP is hydrolyzed by myosin, which uses the released energy to move into the "cocked position" whereby it binds weakly to a part of the actin binding site. The remainder of the actin binding site is blocked by tropomyosin. With the ATP hydrolyzed, the cocked myosin head now contains adenosine diphosphate (ADP) + Pi. Two  ions bind to troponin C on the actin filaments. The troponin- complex causes tropomyosin to slide over and unblock the remainder of the actin binding site. Unblocking the rest of the actin binding sites allows the two myosin heads to close and myosin to bind strongly to actin. The myosin head then releases the inorganic phosphate and initiates a power stroke, which generates a force of 2 pN. The power stroke moves the actin filament inwards, thereby shortening the sarcomere. Myosin then releases ADP but still remains tightly bound to actin. At the end of the power stroke, ADP is released from the myosin head, leaving myosin attached to actin in a rigor state until another ATP binds to myosin. A lack of ATP would result in the rigor state characteristic of rigor mortis. Once another ATP binds to myosin, the myosin head will again detach from actin and another cross-bridge cycle occurs.

Cross-bridge cycling is able to continue as long as there are sufficient amounts of ATP and  in the cytoplasm. Termination of cross-bridge cycling can occur when  is actively pumped back into the sarcoplasmic reticulum. When  is no longer present on the thin filament, the tropomyosin changes conformation back to its previous state so as to block the binding sites again. The myosin ceases binding to the thin filament, and the muscle relaxes. The  ions leave the troponin molecule to maintain the  ion concentration in the sarcoplasm. The active pumping of  ions into the sarcoplasmic reticulum creates a deficiency in the fluid around the myofibrils. This causes the removal of  ions from the troponin. Thus, the tropomyosin-troponin complex again covers the binding sites on the actin filaments and contraction ceases.

Gradation of skeletal muscle contractions

The strength of skeletal muscle contractions can be broadly separated into twitch, summation, and tetanus. A twitch is a single contraction and relaxation cycle produced by an action potential within the muscle fiber itself. The time between a stimulus to the motor nerve and the subsequent contraction of the innervated muscle is called the latent period, which usually takes about 10 ms and is caused by the time taken for nerve action potential to propagate, the time for chemical transmission at the neuromuscular junction, then the subsequent steps in excitation-contraction coupling.

If another muscle action potential were to be produced before the complete relaxation of a muscle twitch, then the next twitch will simply sum onto the previous twitch, thereby producing a summation. Summation can be achieved in two ways: frequency summation and multiple fiber summation. In frequency summation, the force exerted by the skeletal muscle is controlled by varying the frequency at which action potentials are sent to muscle fibers. Action potentials do not arrive at muscles synchronously, and, during a contraction, some fraction of the fibers in the muscle will be firing at any given time. In a typical circumstance, when humans are exerting their muscles as hard as they are consciously able, roughly one-third of the fibers in each of those muscles will fire at once, though this ratio can be affected by various physiological and psychological factors (including Golgi tendon organs and Renshaw cells). This 'low' level of contraction is a protective mechanism to prevent avulsion of the tendon—the force generated by a 95% contraction of all fibers is sufficient to damage the body. In multiple fiber summation, if the central nervous system sends a weak signal to contract a muscle, the smaller motor units, being more excitable than the larger ones, are stimulated first. As the strength of the signal increases, more motor units are excited in addition to larger ones, with the largest motor units having as much as 50 times the contractile strength as the smaller ones. As more and larger motor units are activated, the force of muscle contraction becomes progressively stronger. A concept known as the size principle, allows for a gradation of muscle force during weak contraction to occur in small steps, which then become progressively larger when greater amounts of force are required.

Finally, if the frequency of muscle action potentials increases such that the muscle contraction reaches its peak force and plateaus at this level, then the contraction is a tetanus.

Length-tension relationship

Length-tension relationship relates the strength of an isometric contraction to the length of the muscle at which the contraction occurs. Muscles operate with greatest active tension when close to an ideal length (often their resting length). When stretched or shortened beyond this (whether due to the action of the muscle itself or by an outside force), the maximum active tension generated decreases. This decrease is minimal for small deviations, but the tension drops off rapidly as the length deviates further from the ideal. Due to the presence of elastic proteins within a muscle cell (such as titin) and extracellular matrix, as the muscle is stretched beyond a given length, there is an entirely passive tension, which opposes lengthening. Combined, there is a strong resistance to lengthening an active muscle far beyond the peak of active tension.

Force-velocity relationships

Force–velocity relationship relates the speed at which a muscle changes its length (usually regulated by external forces, such as load or other muscles) to the amount of force that it generates. Force declines in a hyperbolic fashion relative to the isometric force as the shortening velocity increases, eventually reaching zero at some maximum velocity. The reverse holds true for when the muscle is stretched – force increases above isometric maximum, until finally reaching an absolute maximum. This intrinsic property of active muscle tissue plays a role in the active damping of joints that are actuated by simultaneously active opposing muscles. In such cases, the force-velocity profile enhances the force produced by the lengthening muscle at the expense of the shortening muscle. This favoring of whichever muscle returns the joint to equilibrium effectively increases the damping of the joint. Moreover, the strength of the damping increases with muscle force. The motor system can thus actively control joint damping via the simultaneous contraction (co-contraction) of opposing muscle groups.

Smooth muscle

Smooth muscles can be divided into two subgroups: single-unit and multiunit. Single-unit smooth muscle cells can be found in the gut and blood vessels. Because these cells are linked together by gap junctions, they are able to contract as a functional syncytium. Single-unit smooth muscle cells contract myogenically, which can be modulated by the autonomic nervous system.

Unlike single-unit smooth muscle cells, multiunit smooth muscle cells are found in the muscle of the eye and in the base of hair follicles. Multiunit smooth muscle cells contract by being separately stimulated by nerves of the autonomic nervous system. As such, they allow for fine control and gradual responses, much like motor unit recruitment in skeletal muscle.

Mechanisms of smooth muscle contraction

The contractile activity of smooth muscle cells can be tonic (sustained) or phasic (transient) and is influenced by multiple inputs such as spontaneous electrical activity, neural and hormonal inputs, local changes in chemical composition, and stretch. This is in contrast to the contractile activity of skeletal muscle cells, which relies on a single neural input. Some types of smooth muscle cells are able to generate their own action potentials spontaneously, which usually occur following a pacemaker potential or a slow wave potential. These action potentials are generated by the influx of extracellular , and not . Like skeletal muscles, cytosolic  ions are also required for crossbridge cycling in smooth muscle cells.

The two sources for cytosolic  in smooth muscle cells are the extracellular  entering through calcium channels and the  ions that are released from the sarcoplasmic reticulum. The elevation of cytosolic  results in more  binding to calmodulin, which then binds and activates myosin light-chain kinase. The calcium-calmodulin-myosin light-chain kinase complex phosphorylates myosin on the 20 kilodalton (kDa) myosin light chains on amino acid residue-serine 19, enabling the molecular interaction of myosin and actin, and initiating contraction and activating the myosin ATPase.  Unlike skeletal muscle cells, smooth muscle cells lack troponin, even though they contain the thin filament protein tropomyosin and other notable proteins – caldesmon and calponin.  Thus, smooth muscle contractions are initiated by the -activated phosphorylation of myosin rather than  binding to the troponin complex that regulates myosin binding sites on actin like in skeletal and cardiac muscles.

Termination of crossbridge cycling (and leaving the muscle in latch-state) occurs when myosin light chain phosphatase removes the phosphate groups from the myosin heads. Phosphorylation of the 20 kDa myosin light chains correlates well with the shortening velocity of smooth muscle. During this period, there is a rapid burst of energy use as measured by oxygen consumption. Within a few minutes of initiation, the calcium level markedly decreases, the 20 kDa myosin light chains' phosphorylation decreases, and energy use decreases; however, force in tonic smooth muscle is maintained. During contraction of muscle, rapidly cycling crossbridges form between activated actin and phosphorylated myosin, generating force. It is hypothesized that the maintenance of force results from dephosphorylated "latch-bridges" that slowly cycle and maintain force. A number of kinases such as rho kinase, DAPK3, and protein kinase C are believed to participate in the sustained phase of contraction, and  flux may be significant.

Neuromodulation
Although smooth muscle contractions are myogenic, the rate and strength of their contractions can be modulated by the autonomic nervous system. Postganglionic nerve fibers of parasympathetic nervous system release the neurotransmitter acetylcholine, which binds to muscarinic acetylcholine receptors (mAChRs) on smooth muscle cells. These receptors are metabotropic, or G-protein coupled receptors that initiate a second messenger cascade. Conversely, postganglionic nerve fibers of the sympathetic nervous system release the neurotransmitters epinephrine and norepinephrine, which bind to adrenergic receptors that are also metabotropic. The exact effects on the smooth muscle depend on the specific characteristics of the receptor activated—both parasympathetic input and sympathetic input can be either excitatory (contractile) or inhibitory (relaxing).

Cardiac muscle

There are two types of cardiac muscle cells: autorhythmic and contractile. Autorhythmic cells do not contract, but instead set the pace of contraction for other cardiac muscle cells, which can be modulated by the autonomic nervous system. In contrast, contractile muscle cells (cardiomyocytes) constitute the majority of the heart muscle and are able to contract.

Excitation-contraction coupling
In both skeletal and cardiac muscle excitation-contraction (E-C) coupling, depolarization conduction and Ca2+ release processes occur. However, though the proteins involved are similar, they are distinct in structure and regulation. The dihydropyridine receptors (DHPRs) are encoded by different genes, and the ryanodine receptors (RyRs) are distinct isoforms. Besides, DHPR contacts with RyR1 (main RyR isoform in skeletal muscle) to regulate Ca2+ release in skeletal muscle, while the L-type calcium channel (DHPR on cardiac myocytes) and RyR2 (main RyR isoform in cardiac muscle) are not physically coupled in cardiac muscle, but face with each other by a junctional coupling.

Unlike skeletal muscle, E-C coupling in cardiac muscle is thought to depend primarily on a mechanism called calcium-induced calcium release, which is based on the junctional structure between T-tubule and sarcoplasmic reticulum. Junctophilin-2 (JPH2) is essential to maintain this structure, as well as the integrity of T-tubule. Another protein, receptor accessory protein 5 (REEP5), functions to keep the normal morphology of junctional SR. Defects of junctional coupling can result from deficiencies of either of the two proteins.  During the process of calcium-induced calcium release, RyR2s are activated by a calcium trigger, which is brought about by the flow of Ca2+ through the L-type calcium channels. After this, cardiac muscle tends to exhibit diad structures, rather than triads.

Excitation-contraction coupling in cardiac muscle cells occurs when an action potential is initiated by pacemaker cells in the sinoatrial node or atrioventricular node and conducted to all cells in the heart via gap junctions. The action potential travels along the surface membrane into T-tubules (the latter are not seen in all cardiac cell types) and the depolarisation causes extracellular  to enter the cell via L-type calcium channels and possibly sodium-calcium exchanger (NCX) during the early part of the plateau phase. Although this Ca2+ influx only count for about 10% of the Ca2+ needed for activation, it is relatively larger than that of skeletal muscle. This  influx causes a small local increase in intracellular . The increase of intracellular  is detected by RyR2 in the membrane of the sarcoplasmic reticulum, which releases  in a positive feedback physiological response. This positive feedback is known as calcium-induced calcium release and gives rise to calcium sparks ( sparks). The spatial and temporal summation of ~30,000  sparks gives a cell-wide increase in cytoplasmic calcium concentration. The increase in cytosolic calcium following the flow of calcium through the cell membrane and sarcoplasmic reticulum is moderated by calcium buffers, which bind a large proportion of intracellular calcium.  As a result, a large increase in total calcium leads to a relatively small rise in free .

The cytoplasmic calcium binds to Troponin C, moving the tropomyosin complex off the actin binding site allowing the myosin head to bind to the actin filament. From this point on, the contractile mechanism is essentially the same as for skeletal muscle (above). Briefly, using ATP hydrolysis, the myosin head pulls the actin filament toward the centre of the sarcomere.

Following systole, intracellular calcium is taken up by the sarco/endoplasmic reticulum ATPase (SERCA) pump back into the sarcoplasmic reticulum ready for the next cycle to begin. Calcium is also ejected from the cell mainly by the sodium-calcium exchanger (NCX) and, to a lesser extent, a plasma membrane calcium ATPase.  Some calcium is also taken up by the mitochondria. An enzyme, phospholamban, serves as a brake for SERCA. At low heart rates, phospholamban is active and slows down the activity of the ATPase so that  does not have to leave the cell entirely. At high heart rates, phospholamban is phosphorylated and deactivated thus taking most  from the cytoplasm back into the sarcoplasmic reticulum.  Once again, calcium buffers moderate this fall in concentration, permitting a relatively small decrease in free concentration in response to a large change in total calcium. The falling concentration allows the troponin complex to dissociate from the actin filament thereby ending contraction.  The heart relaxes, allowing the ventricles to fill with blood and begin the cardiac cycle again.

Invertebrate

Circular and longitudinal muscles

In annelids such as earthworms and leeches, circular and longitudinal muscles cells form the body wall of these animals and are responsible for their movement. In an earthworm that is moving through a soil, for example, contractions of circular and longitudinal muscles occur reciprocally while the coelomic fluid serves as a hydroskeleton by maintaining turgidity of the earthworm. When the circular muscles in the anterior segments contract, the anterior portion of animal's body begins to constrict radially, which pushes the incompressible coelomic fluid forward and increasing the length of the animal. As a result, the front end of the animal moves forward. As the front end of the earthworm becomes anchored and the circular muscles in the anterior segments become relaxed, a wave of longitudinal muscle contractions passes backwards, which pulls the rest of animal's trailing body forward. These alternating waves of circular and longitudinal contractions is called peristalsis, which underlies the creeping movement of earthworms.

Obliquely striated muscles

Invertebrates such as annelids, mollusks, and nematodes, possess obliquely striated muscles, which contain bands of thick and thin filaments that are arranged helically rather than transversely, like in vertebrate skeletal or cardiac muscles. In bivalves, the obliquely striated muscles can maintain tension over long periods without using too much energy. Bivalves use these muscles to keep their shells closed.

Asynchronous muscles

Advanced insects such as wasps, flies, bees, and beetles possess asynchronous muscles that constitute the flight muscles in these animals. These flight muscles are often called fibrillar muscles because they contain myofibrils that are thick and conspicuous. A remarkable feature of these muscles is that they do not require stimulation for each muscle contraction. Hence, they are called asynchronous muscles because the number of contractions in these muscles do not correspond (or synchronize) with the number of action potentials. For example, a wing muscle of a tethered fly may receive action potentials at a frequency of 3 Hz but it is able to beat at a frequency of 120 Hz. The high frequency beating is made possible because the muscles are connected to a resonant system, which is driven to a natural frequency of vibration.

History

In 1780, Luigi Galvani discovered that the muscles of dead frogs' legs twitched when struck by an electrical spark. This was one of the first forays into the study of bioelectricity, a field that still studies the electrical patterns and signals in tissues such as nerves and muscles.

In 1952, the term excitation–contraction coupling was coined to describe the physiological process of converting an electrical stimulus to a mechanical response. This process is fundamental to muscle physiology, whereby the electrical stimulus is usually an action potential and the mechanical response is contraction. Excitation–contraction coupling can be dysregulated in many diseases. Though excitation–contraction coupling has been known for over half a century, it is still an active area of biomedical research. The general scheme is that an action potential arrives to depolarize the cell membrane. By mechanisms specific to the muscle type, this depolarization results in an increase in cytosolic calcium that is called a calcium transient. This increase in calcium activates calcium-sensitive contractile proteins that then use ATP to cause cell shortening.

The mechanism for muscle contraction evaded scientists for years and requires continued research and updating. The sliding filament theory was independently developed by Andrew F. Huxley and Rolf Niedergerke and by Hugh Huxley and Jean Hanson. Their findings were published as two consecutive papers published in the 22 May 1954 issue of Nature under the common theme "Structural Changes in Muscle During Contraction".

See also
 Anatomical terms of motion
 calcium-induced calcium release
 Cardiac action potential
 Cramp
 Dystonia
 Exercise physiology
 Fasciculation
 Hill's muscle model
 Hypnic jerk
 In vitro muscle testing
 Lombard's paradox
 Myoclonus
 Rigor mortis
 Spasm
 Uterine contraction

References

Further reading
 Krans, J. L. (2010) The Sliding Filament Theory of Muscle Contraction. Nature Education 3(9):66
 Saladin, Kenneth S., Stephen J. Sullivan, and Christina A. Gan. (2015). Anatomy & Physiology: The Unity of Form and Function. 7th ed. New York: McGraw-Hill Education.

External links
 Animation: Myofilament Contraction
 Sliding Filament Model of Muscle Contraction

Exercise physiology
Muscular system
Skeletal muscle
Musculoskeletal system
Neurology

Muscle contraction


Bhaiyaa is Magahi language film released in 1961  directed by Phani Majumdar.

Cast
 Tarun Bose as  Parmanand
 Vijaya Choudhury as  Bindu
 Gopal as  Murli
 Helen as  Dancer / Singer at Murli's son's birthday
 Padma Khanna as  Chandra Hariram Prasad (as Kumari Padma)
 Shubha Khote as  Pretty village girl
 Achala Sachdev as  Maya
 Bhagwan Sinha
 Lata Sinha as  Kamla
 Ramayan Tiwari as  Gulati

Synopsis
Parmanand lives a poor lifestyle in a village along with his widowed stepmother, Maya, and her two children, a son, Murli, who is studying in a Bombay college, and daughter, Kamla. Parmanand is in love with beautiful Bindu and hopes to marry her someday. When Murli returns home after obtaining a degree in arts, Parmanand notices that he loves Bindu, so he steps aside and permits him to marry her much to Maya's displeasure. Shortly after the marriage, Parmanand finds out that Murli has been spending a lot of time with Chandra, the daughter of Hariram Prasad. When he counsels Murli, he gets abused, and beats Murli up.  Upset at this treatment, Murli and Bindu move out. Shortly thereafter Bindu gets pregnant much to Chandra's displeasure. Chandra confronts Bindu in a bid to make her hate her child and force her to abort while Murli files a claim in Court contesting his late father's Will as a forgery. Watch what impact this has on the rest of the family.

See also
 Cinema of Bihar

References

External links

Magahi-language films
1965 films
Films directed by Phani Majumdar
Films with screenplays by Phani Majumdar

Bhaiyaa


Humanitarian aid is material and logistic assistance to people who need help. It is usually short-term help until the long-term help by the government and other institutions replaces it. Among the people in need are the homeless, refugees, and victims of natural disasters, wars, and famines. Humanitarian relief efforts are provided for humanitarian purposes and include natural disasters and human-made disasters. The primary objective of humanitarian aid is to save lives, alleviate suffering, and maintain human dignity. It may, therefore, be distinguished from development aid, which seeks to address the underlying socioeconomic factors which may have led to a crisis or emergency. There is a debate on linking humanitarian aid and development efforts, which was reinforced by the World Humanitarian Summit in 2016. However, the conflation is viewed critically by practitioners.

Humanitarian aid is seen as "a fundamental expression of the universal value of solidarity between people and a moral imperative". Humanitarian aid can come from either local or international communities. In reaching out to international communities, the Office for the Coordination of Humanitarian Affairs (OCHA) of the United Nations (UN) is responsible for coordination responses to emergencies. It taps to the various members of Inter-Agency Standing Committee, whose members are responsible for providing emergency relief.  The four UN entities that have primary roles in delivering humanitarian aid are United Nations Development Programme (UNDP), the United Nations Refugee Agency (UNHCR), the United Nations Children's Fund (UNICEF) and the World Food Programme (WFP).

The International Committee of the Red Cross understands humanitarian relief as a norm in both international and non-international armed conflicts, and countries or war parties that prevent humanitarian relief are generally widely criticized. According to The Overseas Development Institute, a London-based research establishment, whose findings were released in April 2009 in the paper "Providing aid in insecure environments: 2009 Update", the most lethal year for aid providers in the history of humanitarianism was 2008, in which 122 aid workers were murdered and 260 assaulted. The countries deemed least safe were Somalia and Afghanistan. In 2014, Humanitarian Outcomes reported that the countries with the highest incidents were: Afghanistan, Democratic Republic of the Congo, Central African Republic, South Sudan, Sudan, Syria, Pakistan, Somalia, Yemen and Kenya.

According to the Global Humanitarian Overview of OCHA, 274 million people need humanitarian assistance and protection in 2022, or 1 out of 29 people worldwide.

Some scholars define humanitarian obligations as 'unfixed' and precisely because of that "when recipients of aid call on different parties - agencies, governments, the international community - to fulfill these obligations, they often seek to expand their limits".

History

Origins

The beginnings of organized international humanitarian aid can be traced to the late 19th century. Early campaigns include British aid to distressed populations on the continent and in Sweden during the Napoleonic Wars, and the international relief campaigns during the Great Irish Famine in the 1840s.

In 1854, when the Crimean War began Florence Nightingale and her team of 38 nurses arrived to Barracks Hospital of Scutari where there were thousands of sick and wounded soldiers. Nightingale and her team watched as the understaffed military hospitals struggled to maintain hygienic conditions and meet the needs of patients. Ten times more soldiers were dying of disease than from battle wounds. Typhus, typhoid, cholera and dysentery were common in the army hospitals. Nightingale and her team established a kitchen, laundry and increased hygiene. More nurses arrived to aid in the efforts and the General Hospital at Scutari was able to care for 6,000 patients.
Nightingale's contributions still influence humanitarian aid efforts. This is especially true in regard to Nightingale's use of statistics and measures of mortality and morbidity. Nightingale used principles of new science and statistics to measure progress and plan for her hospital. She kept records of the number and cause of deaths in order to continuously improve the conditions in hospitals. Her findings were that in every 1,000 soldiers, 600 were dying of communicable and infectious diseases. She worked to improve hygiene, nutrition and clean water and decreased the mortality rate from 60% to 42% to 2.2%. All of these improvements are pillars of modern humanitarian intervention. Once she returned to Great Britain she campaigned for the founding of the Royal Commission on the Health of the Army. She advocated for the use of statistics and coxcombs to portray the needs of those in conflict settings.

The most well-known origin story of formalized humanitarian aid is that of Henri Dunant, a Swiss businessman and social activist, who upon seeing the sheer destruction and inhumane abandonment of wounded soldiers from the Battle of Solferino in June 1859, canceled his plans and began a relief response.  Despite little to no experience as a medical physician, Dunant worked alongside local volunteers to assist the wounded soldiers from all warring parties, including Austrian, Italian and French casualties, in any way he could including the provision of food, water, and medical supplies. His graphic account of the immense suffering he witnessed, written in his book A Memory of Solferino, became a foundational text to modern humanitarianism.

A Memory of Solferino changed the world in a way that no one, let alone Dunant, could have foreseen nor truly appreciated at the time. To start, Dunant was able to profoundly stir the emotions of his readers by bringing the battle and suffering into their homes, equipping them to understand the current barbaric state of war and treatment of soldiers after they were injured or killed; in of themselves these accounts altered the course of history. Beyond this, in his two-week experience attending to the wounded soldiers of all nationalities, Dunant inadvertently established the vital conceptual pillars of what would later become the International Committee of the Red Cross and International Humanitarian Law: impartiality and neutrality. Dunant took these ideas and came up with two more ingenious concepts that would profoundly alter the practice of war; first Dunant envisioned a creation of permanent volunteer relief societies, much like the ad hoc relief group he coordinated in Solferino, to assist wounded soldiers; next Dunant began an effort to call for the adoption of a treaty which would guarantee the protection of wounded soldiers and any who attempted to come to their aid.

After publishing his foundational text in 1862, progress came quickly for Dunant and his efforts to create a permanent relief society and International Humanitarian Law. The embryonic formation of the International Committee of the Red Cross had begun to take shape in 1863 when the private Geneva Society of Public Welfare created a permanent sub-committee called "The International Committee for Aid to Wounded in Situations of War". Composed of five Geneva citizens, this committee endorsed Dunant's vision to legally neutralize medical personnel responding to wounded soldiers. The constitutive conference of this committee in October 1863 created the statutory foundation of the International Committee of the Red Cross in their resolutions regarding national societies, caring for the wounded, their symbol, and most importantly the indispensable neutrality of ambulances, hospitals, medical personnel and the wounded themselves. Beyond this, in order to solidify humanitarian practice, the Geneva Society of Public Welfare hosted a convention between 8 and 22 August 1864 at the Geneva Town Hall with 16 diverse States present, including many governments of Europe, the Ottoman Empire, the United States of America (USA), Brazil and Mexico. This diplomatic conference was exceptional, not due to the number or status of its attendees but rather because of its very raison d'être. Unlike many diplomatic conferences before it, this conference's purpose was not to reach a settlement after a conflict nor to mediate between opposing interests; indeed this conference was to lay down rules for the future of conflict with aims to protect medical services and those wounded in battle.

The first of the renowned Geneva Conventions was signed on 22 August 1864; never before in history has a treaty so greatly impacted how warring parties engage with one another. The basic tenents of the convention outlined the neutrality of medical services, including hospitals, ambulances, and related personnel, the requirement to care for and protect the sick and wounded during the conflict and something of particular symbolic importance to the International Committee of the Red Cross: the Red Cross emblem. For the first time in contemporary history, it was acknowledged by a representative selection of states that war had limits. The significance only grew with time in the revision and adaptation of the Geneva Convention in 1906, 1929 and 1949; additionally, supplementary treaties granted protection to hospital ships, prisoners of war and most importantly to civilians in wartime.

The International Committee of the Red Cross exists to this day as the guardian of International Humanitarian Law and as one of the largest providers of humanitarian aid in the world.

Late 19th century

Internationally organized humanitarian aid efforts continued to be launched for the rest of the century, often with ever-greater logistical acumen and experience. In 1876, after a drought led to cascading crop failures across Northern China, a famine broke out that lasted several years—during its course as many as 10 million people may have died from hunger and disease. British missionary Timothy Richard first called international attention to the famine in Shandong in the summer of 1876 and appealed to the foreign community in Shanghai for money to help the victims. The Shandong Famine Relief Committee was soon established, with those participating including diplomats, businessmen, as well as Christian missionaries, Catholic and Protestant alike. An international network was set up to solicit donations, ultimately bringing in 204,000 silver taels, the equivalent of $7–10 million if valued at 2012 silver prices.

Simultaneously in India, another campaign was launched in response to the Great Famine of 1876–78. Retrospectively, authorities from across the administrative and colonial structures of the British Raj and princely states have been to various degrees blamed for the shocking severity of the famine, with critiques revolving around their laissez-faire attitude and the resulting lack of any adequate policy to address the mass death and suffering across the subcontinent, though meaningful relief measures began to be introduced towards the famine's end. Privately, a famine relief fund was set up in the United Kingdom, raising £426,000 within its first few months of operation.

Early 20th century
Intertwined with and informed efforts related to the profound destruction and disruption caused by World War I, including that of the Red Cross and Red Crescent organization, the Russian famine of 1921–1922, taking place in a country already immensely burdened with systemic agriculture and logistical struggles—then ravaged by successive periods of industrial war, blockade, bad harvests, the Russian Revolution, its resulting political restructuring and social upheaval, and then the insurgency and war communism of the Russian Civil War that followed. In the nascent Russian Soviet Federative Socialist Republic, Vladimir Lenin allowed his personal friend and acclaimed thinker Maxim Gorky to pen an open letter to the international community asking for relief for the Russian people. Despite the ongoing ideological, material, and military conflicts levied by both the new socialist state and the capitalist international community towards one another, efforts to aid the starving population of Soviet Russia were intensive, deliberate, and effective. American efforts, led in large part future president Herbert Hoover, as well as those by the International Committee for Russian Relief joined extant humanitarian organizations in delivering food and medicine to Russia over the course of 1921 and 1922, at some points feeding over 10 millions Russians every day. With the United States left relatively untouched by World War I, its intensive private and public efforts in Russia constituted a clear expression of its new paramount soft power on the international stage, with power projection from European states having been either totally destroyed or severely limited in scope in the years following the conflict.

1980s

Early attempts were in private hands and were limited in their financial and organizational capabilities. It was only in the 1980s, that global news coverage and celebrity endorsement were mobilized to galvanize large-scale government-led famine (and other forms of) relief in response to disasters around the world. The 1983–85 famine in Ethiopia caused upwards of 1 million deaths and was documented by a BBC news crew, with Michael Buerk describing "a biblical famine in the 20th Century" and "the closest thing to hell on Earth".

Live Aid, a 1985 fund-raising effort headed by Bob Geldof induced millions of people in the West to donate money and to urge their governments to participate in the relief effort in Ethiopia. Some of the proceeds also went to the famine hit areas of Eritrea.

2000s

A 2004 reform initiative by Jan Egeland, resulted in the creation of the Humanitarian Cluster System, designed to improve coordination between humanitarian agencies working on the same issues.

2010s

World Humanitarian Summit

The first global summit on humanitarian diplomacy was held in 2016 in Istanbul, Turkey. An initiative of United Nations Secretary-General Ban Ki-moon, the World Humanitarian Summit included participants from governments, civil society organizations, private organizations, and groups affected by humanitarian need. Issues that were discussed included: preventing and ending conflict, managing crises, and aid financing.

Attendees at the summit agreed a series of reforms on aid spending called the Grand Bargain, including a commitment to spend 25% of aid funds directly through local and national humanitarian aid organizations.

Funding

Aid is funded by donations from individuals, corporations, governments and other organizations. The funding and delivery of humanitarian aid is increasingly international, making it much faster, more responsive, and more effective in coping to major emergencies affecting large numbers of people (e.g. see Central Emergency Response Fund). The United Nations Office for the Coordination of Humanitarian Affairs (OCHA) coordinates the international humanitarian response to a crisis or emergency pursuant to Resolution 46/182 of the United Nations General Assembly. The need for aid is ever-increasing and has long outstripped the financial resources available.

The Central Emergency Response Fund was created at the 2005 Central Emergency Response Fund at the United Nations General Assembly.

Types of humanitarian aid

Medical humanitarian aid
There are different kinds of medical humanitarian aid, including: providing medical supplies and equipment; sending professionals to an affected region; and, long-term training for local medical staff. Such aid emerged when international organizations stepped in to respond to the need of national governments for global support and partnership to address natural disasters, wars, and other crises that impact people's health. Often, a humanitarian aid organization would clash with a government's approach to the unfolding domestic conflict. In such cases, humanitarian aid organizations have sought out autonomy to extend help regardless of political or ethnic affiliation.

Limitations
Humanitarian medical aid as a sector possesses several limitations. First, multiple organizations often exist to solve the same problem. Rather than collaborating to address a given situation, organizations frequently interact as competitors, which creates bottlenecks of treatment and supplies. A second limitation is how humanitarian organizations are focused on a specific disaster or epidemic, without a plan for whatever might come next; international organizations frequently enter a region, provide short term aid, and then exit without ensuring local capacity to maintain or sustain this medical care. Finally, humanitarian medical aid assumes a biomedical approach which does not always account for the alternative beliefs and practices about health and well-being in the affected regions. This problem is rarely explored as most studies conducted are done from the lens of the donor or Westernized humanitarian organization rather than the recipient country's perspective. Discovering ways of encouraging locals to embrace bio-medicine approaches while simultaneously respecting a given people's culture and beliefs remains a major challenge for humanitarian aid organizations; in particular as organizations constantly enter new regions as crises occur. However, understanding how to provide aid cohesively with existing regional approaches is necessary in securing the local peoples' acceptance of the humanitarian aid's work.

Delivery of humanitarian aid

Methods of delivery

Humanitarian aid spans a wide range of activities, including providing food aid, shelter, education, healthcare or protection. The majority of aid is provided in the form of in-kind goods or assistance, with cash and vouchers constituting only 6% of total humanitarian spending. However, evidence has shown how cash transfers can be better for recipients as it gives them choice and control, they can be more cost-efficient and better for local markets and economies.

It is important to note that humanitarian aid is not only delivered through aid workers sent by bilateral, multilateral or intergovernmental organizations, such as the United Nations. Actors like the affected people themselves, civil society, local informal first-responders, civil society, the diaspora, businesses, local governments, military, local and international non-governmental organizations all play a crucial role in a timely delivery of humanitarian aid.

How aid is delivered can affect the quality and quantity of aid. Often in disaster situations, international aid agencies work in hand with local agencies. There can be different arrangements on the role these agencies play, and such arrangement affects that quality of hard and soft aid delivered.

Humanitarian access

Securing access to humanitarian aid in post-disasters, conflicts, and complex emergencies is a major concern for humanitarian actors. To win assent for interventions, aid agencies often espouse the principles of humanitarian impartiality and neutrality. However, gaining secure access often involves negotiation and the practice of humanitarian diplomacy. In the arena of negotiations, humanitarian diplomacy is ostensibly used by humanitarian actors to try to persuade decision makers and leaders to act, at all times and in all circumstances, in the interest of vulnerable people and with full respect for fundamental humanitarian principles. However, humanitarian diplomacy is also used by state actors as part of their foreign policy.

United Nations' response
The UN implements a multifaceted approach to assist migrants and refugees throughout their relocation process. This includes children's integration into the local education system, food security, and access to health services. The approach also encompasses humanitarian transportation, the goal of which is to ensure migrants and refugees retain access to basic goods and services and the labour market. Basic needs, including access to shelter, clean water, and child protection, are supplemented by the UN's efforts to facilitate social integration and legal regularization for displaced individuals.

Technology and humanitarian aid
Traditionally, humanitarian organizations have concentrated their efforts in the delivery of human, medical, food, shelter and water sanitation and hygiene resources during humanitarian emergencies.

Nevertheless, since the 2010 Haiti Earthquake, the institutional and operational focus of humanitarian aid has been on leveraging technology to enhance humanitarian action, ensuring that more formal relationships are established, and improving the interaction between formal humanitarian organizations such as the United Nations (UN) Office for the Coordination of Humanitarian Affairs (OCHA) and informal volunteer and technological communities known as digital humanitarians.

The recent rise in Big Data, high-resolution satellite imagery and new platforms powered by advanced computing have already prompted the development of crisis mapping to help humanitarian organizations make sense of the vast volume and velocity of information generated during disasters. For example, crowdsourcing maps (such as OpenStreetMap) and social media messages in Twitter were used during the 2010 Haiti Earthquake and Hurricane Sandy to trace leads of missing people, infrastructure damages and rise new alerts for emergencies.

Satellite imagery is now used to predict how many people will be displaced from their homes and where they will likely move. Such insights helps emergency personnel to identify how much aid in terms of water, food and medical care will be needed and where to send it before they conduct a Rapid Needs Assessment on the field, and at the same time it helps prevent putting the humanitarian organization personnel at risk. Artificial intelligence algorithms may instantaneously assess flooding, building and road damage based on satellite images and weather forecasts, allowing rescuers to distribute emergency aid more effectively and identify those still in danger and isolated from escape routes.
Another example that illustrates technology used for humanitarian purposes is the Artificial Intelligence for Digital Response platform which is a free and open source software that automatically collects and classifies tweets that are posted during emergencies, humanitarian crises and disasters. AIDR uses human and machine intelligence to automatically tag up to thousands of messages per minute so humanitarian organizations are able to make faster decisions depending on the trends from the data collected during a specific kind of emergency.

Big data for humanitarian operations provides a unique opportunity to access instantaneously contextual information about pending and ongoing humanitarian crises. The development of rigorous information management systems may lead to feasible mechanisms for forecasting and preventing crises. Nevertheless, there are important issues to be discussed concerning the veracity and validity of data. Data that are collected or generated through digital or mobile mechanisms will often pose additional challenges, especially regarding the verification when the information comes from social media. Though a significant amount of work is under way to develop software and algorithms for verifying crowdsourced or anonymously provided data, such tools are not yet operational or widely available. Also, multiple data transactions and increased complexity in data structures raise the potential for error in humanitarian data entry and interpretation, and this raises concerns about the accuracy and representativeness of data that is used for policy decisions in highly pressurized situations that demand quick decision-making.

Gender and humanitarian aid
Even prior to a humanitarian crisis, gender differences exist. Women have limited access to paid work, are at risk of child marriage, and are more exposed to Gender based violence, such as rape and domestic abuse. Conflict and natural disasters exacerbate women's vulnerabilities. When delivering humanitarian aid, it is thus important for humanitarian actors, such as the United Nations, to include challenges specific to women in their humanitarian response. The Inter-Agency Standing Committee provides guidelines for humanitarian actors on how be inclusive of gender when delivering humanitarian aid. It recommends agencies to collect data disaggregated by sex and age to better understand which group of the population is in need of what type of aid. In recent years, the United Nations have been using sex and age disaggregated data more and more, consulting with gender specialists. In the assessment phase, several UN agencies meet to compile data and work on a humanitarian response plan. Throughout the plans. women specific challenges are listed and sex and age disaggregated data are used so when they deliver aid to a country facing a humanitarian crisis, girls and women can have access to the aid they need.

Humanitarian aid and conflict

In addition to post-conflict settings, a large portion of aid is often directed at countries currently undergoing conflicts. However, the effectiveness of humanitarian aid, particularly food aid, in conflict-prone regions has been criticized in recent years. There have been accounts of humanitarian aid being not only inefficacious but actually fuelling conflicts in the recipient countries. Aid stealing is one of the prime ways in which conflict is promoted by humanitarian aid. Aid can be seized by armed groups, and even if it does reach the intended recipients, "it is difficult to exclude local members of a local militia group from being direct recipients if they are also malnourished and qualify to receive aid." Furthermore, analyzing the relationship between conflict and food aid, recent research shows that the United States food aid promoted civil conflict in recipient countries on average. An increase in United States' wheat aid increased the duration of armed civil conflicts in recipient countries, and ethnic polarization heightened this effect. However, since academic research on aid and conflict focuses on the role of aid in post-conflict settings, the aforementioned finding is difficult to contextualize. Nevertheless, research on Iraq shows that "small-scale [projects], local aid spending ... reduces conflict by creating incentives for average citizens to support the government in subtle ways." Similarly, another study also shows that aid flows can "reduce conflict because increasing aid revenues can relax government budget constraints, which can [in return] increase military spending and deter opposing groups from engaging in conflict." Thus, the impact of humanitarian aid on conflict may vary depending upon the type and mode in which aid is received, and, inter alia, the local socio-economic, cultural, historical, geographical and political conditions in the recipient countries.

Humanitarian Rights

Scholars debate the differences between human rights and humanitarian rights and their implications. In the context of refugees, it describes the organizations' responsibility to provide for their needs by considering both "fundamental human rights and humanitarian norms". Humanitarian rights are sometimes used by refugees as means to pursue their political rights. Hence, "humanitarian language, materials and practice can offer a space for politics to hide". As such, according to some scholars, the most evident tool offered by humanitarianism is the 'language of suffering' used by refugees in order to demand a compassionate action that will relieve their suffering.

Waste and corruption in humanitarian aid
Waste and corruption are hard to quantify, in part because they are often taboo subjects, but they appear to be significant in humanitarian aid. For example, it has been estimated that over $8.75  billion was lost to waste, fraud, abuse and mismanagement in the Hurricane Katrina relief effort. Non-governmental organizations have in recent years made great efforts to increase participation, accountability and transparency in dealing with aid, yet humanitarian assistance remains a poorly understood process to those meant to be receiving it—much greater investment needs to be made into researching and investing in relevant and effective accountability systems.

However, there is no clear consensus on the trade-offs between speed and control, especially in emergency situations when the humanitarian imperative of saving lives and alleviating suffering may conflict with the time and resources required to minimise corruption risks. Researchers at the Overseas Development Institute have highlighted the need to tackle corruption with, but not limited to, the following methods:

 Resist the pressure to spend aid rapidly.
 Continue to invest in audit capacity, beyond simple paper trails;
 Establish and verify the effectiveness of complaints mechanisms, paying close attention to local power structures, security and cultural factors hindering complaints;
 Clearly explain the processes during the targeting and registration stages, highlighting points such as the fact that people should not make payments to be included, photocopy and read aloud any lists prepared by leaders or committees.

Contrary practice
Countries or war parties that prevent humanitarian relief are generally under unanimous criticism. Such was the case for the Derg regime, preventing relief to the population of Tigray in the 1980s, and the prevention of relief aid in the Tigray War of 2020–2021 by the Abiy Ahmed Ali regime of Ethiopia was again widely condemned.

Aid workers

Aid workers are people who are distributed internationally to do humanitarian aid work.

Composition

The total number of humanitarian aid workers around the world has been calculated by ALNAP, a network of agencies working in the Humanitarian System, as 210,800 in 2008. This is made up of roughly 50% from NGOs, 25% from the Red Cross/Red Crescent Movement and 25% from the UN system. In 2010, it was reported that the humanitarian fieldworker population increased by approximately 6% per year over the previous 10 years.

Psychological issues
Aid workers are exposed to tough conditions and have to be flexible, resilient, and responsible in an environment that humans are not psychologically supposed to deal with, in such severe conditions that trauma is common. In recent years, a number of concerns have been raised about the mental health of aid workers.

The most prevalent issue faced by humanitarian aid workers is post-traumatic stress disorder (PTSD). Adjustment to normal life again can be a problem, with feelings such as guilt being caused by the simple knowledge that international aid workers can leave a crisis zone, whilst nationals cannot.

A 2015 survey conducted by The Guardian, with aid workers of the Global Development Professionals Network, revealed that 79 percent experienced mental health issues.

Abuse of power by aid workers

Reports of sexual exploitation in sexual exploitation and abuse in humanitarian response have been reported following humanitarian interventions in Liberia, Guinea and Sierra Leone in 2002, in Central African Republic and in the Democratic Republic of the Congo.

2021 reporting on a Racial Equity Index report indicated that just under two-thirds of aid workers have experienced racism and 98% of survey respondents witnessed racism.

Standards

The humanitarian community has initiated a number of interagency initiatives to improve accountability, quality and performance in humanitarian action. Four of the most widely known initiatives are, ALNAP, the CHS Alliance, the Sphere Project and the Core Humanitarian Standard on Quality and Accountability (CHS).  Representatives of these initiatives began meeting together on a regular basis in 2003 in order to share common issues and harmonise activities where possible.

Sphere Project

The Sphere Project handbook, Humanitarian Charter and Minimum Standards in Disaster Response, which was produced by a coalition of leading non-governmental humanitarian agencies, lists the following principles of humanitarian action:
 The right to life with dignity
 The distinction between combatant and non-combatants
 The principle of non-refoulement

Core Humanitarian Standard on Quality and Accountability

Another humanitarian standard used is the Core Humanitarian Standard on Quality and Accountability (CHS). It was approved by the CHS Technical Advisory Group in 2014, and has since been endorsed by many humanitarian actors such as "the Boards of the Humanitarian Accountability Partnership (HAP), People in Aid and the Sphere Project". It comprises nine core standards, which are complemented by detailed guidelines and indicators.

While some critics were questioning whether the sector will truly benefit from the implementation of yet another humanitarian standard, others have praised it for its simplicity. Most notably, it has replaced the core standards of the Sphere Handbook and it is regularly referred to and supported by officials from the United Nations, the EU, various NGOs and institutes.

See also
 Attacks on humanitarian workers
 Hard Choices: Moral Dilemmas in Humanitarian Intervention
 Effective altruism
 Church asylum
 Humanitarian corridor
 Humanitarian Response Index
 Vienna Declaration and Programme of Action
 World Humanitarian Day

References

Further reading

External links

 The Humanitarian Organisations Dataset (HOD): 2,505 organizations active in the humanitarian sector

Critiques of humanitarian aid

Civil affairs
Government aid programs
Philanthropy
Charity
Emergency management

Humanitarian aid


The Old Kingdom, or Abhorsen in North America, is a fantasy series written by Australian author Garth Nix. It originated in 1995 with the novel Sabriel and has continued in the novels Lirael (2001), Abhorsen (2003) and Goldenhand (2016). The series has continued with the prequel novel Clariel (2014) and the latest installment of the series, Terciel & Elinor, was released in November 2021. The Old Kingdom also consists of the novella The Creature in the Case (2005) and other short fiction.

In Australia an omnibus edition comprising three novels and one novella was titled The Old Kingdom Chronicles. Omnibus editions in the U.S. have been titled The Abhorsen Trilogy (2003) and The Abhorsen Chronicles (2009). ISFDB catalogues the entire continuing series as "The Old Kingdom / Abhorsen".

Books in the series

Sabriel

The protagonist, Sabriel, is in her final few days at her school in Ancelstierre (an alternate history of 1910s England), when she is visited by a spirit summoned by her father (the Abhorsen), who is trapped in Death, and departs to rescue him. Travelling into the Old Kingdom, while being hunted, Sabriel makes her way to the ancestral house of the Abhorsens to get clues, equipment, and help. Accompanied by her father's assistant Mogget, she discovers Touchstone; and with him continues to Belisaere (the capital of the Old Kingdom). In a sacred site under the city, Sabriel briefly frees her father, who diverts the antagonist Kerrigor while the others escape.

Sabriel and Touchstone then travel to Ancelstierre to destroy Kerrigor's body, which the local soldiery (at their behest) convey to Wyverly College, Sabriel's school. Kerrigor and his undead followers besiege the college, killing many students and guardsmen; whereupon Mogget, in his true form, fights Kerrigor for the right to kill Sabriel. Kerrigor consumes Mogget and throws Sabriel onto her sword; whereupon she throws Mogget's binding ring over Kerrigor. This creates two cats: a black Kerrigor and white Mogget, which are then bound by Ranna. Sabriel then dies, but is resurrected by her ancestors to succeed her father as the Old Kingdom's protector.

Lirael

The protagonist, Lirael, is raised among the Clayr; but having coal-black hair, a pale complexion, and brown eyes, differs physically from her chestnut-skinned, white-blonde, blue or green-eyed peers, and additionally lacks their native precognition. While trying to make a canine sending, she accidentally summons the immortal 'Disreputable Dog', thereafter her constant companion. In Ancelestierre, Prince Sameth (the son of Sabriel and Touchstone) is attacked by the necromancer Hedge and his summoned Dead Hands (a zombie-like construct); and Sameth's friend Nicholas 'Nick' Sayre is placed under Hedge's control. Sameth's father, Touchstone, thereafter conveys him to their capital Belisaere. Here he is expected to succeed his mother as the Abhorsen, a future of which he is terrified.

Concurrently, Nick Sayre crosses the border into the Old Kingdom and continues to the Red Lake: a region in the south-west of the Kingdom where neither the royal rule nor the Clayr's 'Sight' has influence. Upon news thereof, Sameth goes in search of him, and is later joined by Mogget. Meanwhile, Lirael inherits the artifacts of a Remembrancer (a clairvoyant able to view the past) and is swiftly dispatched to fulfill a very recent vision of herself and Nick Sayre upon the Red Lake. She is joined by Sameth and Mogget en route. All are attacked repeatedly and nearly overcome by Chlorr of the Mask; but they reach the Abhorsens' House, where Lirael is identified as Sabriel's half-sister and heir, and Sameth as successor to the previously extinct 'Wallmakers'.

Abhorsen

The Abhorsen's House is besieged by Dead Hands led by Chlorr of the Mask (an undead sorceress) under the control of the necromancer Hedge. Hedge himself serves Orannis the Destroyer, an immortal imprisoned millennia prior by 7 of its 8 cohorts and now wants to destroy the biosphere. The protagonists escape the siege through a well-like opening, in whose adjoined tunnel they encounter the spirit 'Astarael' (the originator of the Abhorsens' power). Meanwhile, Prince Sameth's parents, the Abhorsen Sabriel and King Touchstone, are in Ancelstierre to stop the genocide of refugees; but are nearly themselves killed by rebels and return to the Old Kingdom. Thereafter descendants of each of the powers that originally created the Charter unite at the two nations' dividing Wall (a fictionalized Hadrian's Wall) to re-enact the imprisonment of Orannis; and having done so, Lirael's 'Disreputable Dog' (a self-identified remnant of the spirit 'Kibeth') revives the dead Nicholas Sayre and departs into the border dividing Life from Death.

Clariel
Clariel, a prequel to the original three books of the series, is set some six hundred years before the events of Sabriel, in an Old Kingdom ruled by an absent King, Orrikan, who refuses to rule, or abdicate to someone who will, until his granddaughter returns to take the crown. In his place, the mercantile Guilds have taken power, led by the powerful Kilp, the Guildmaster of the Goldsmiths, who rules as governor in Belisaere. Clariel is the seventeen-year-old daughter of Jaciel, a talented goldsmith, the estranged daughter of the current Abhorsen and a cousin of the King. A descendant of two of the ancient bloodlines that bind the Kingdom to the Charter, Clariel is a berserk, disinterested in Charter Magic but whose rage and strong will gives her a latent affinity to Free Magic. Clariel's reluctant admission to an academy for the young elite and an encounter with a Free Magic creature leaves her curious about its forbidden power. After a meeting with the King ends badly, Clariel is taken to dine at the Governor's manor, where a chance encounter uncovers that Kilp's son (Clariel's unwanted fiancé) has consorted with a Free Magic creature to cheat his way up the Guild. Clariel's family is killed in the fighting that follows, Clariel briefly escapes, only to be captured. On the verge of escaping once more she is rescued and is spirited away to the Abhorsen's estates in the south, only to be locked away by the Abhorsen for her own safety. Fearing that her parents will not be avenged, Clariel conspires with Mogget to free two of the Free Magic entities imprisoned in the House and to bind them to do her bidding. In the process of doing so, Clariel corrupts her Charter Mark, weakening her link with the Charter and her ability to perform Charter Magic, but at the same time allowing her to perform feats of magic using her own raw willpower to shape and control Free Magic. When she reaches the city, she kills Kilp and his son and rescues the King, only to nearly be killed by the creatures she has bound. She is saved by Belatiel, the new Abhorsen, but is disfigured and badly injured. Belatiel assists her to the forests of the far north, and gives her a bronze mask she earlier used to protect herself from Free Magic. Clariel is destined to later become Chlorr of the Mask.

Goldenhand
Feeling restless after the events of Abhorsen and reeling from the loss of the Disreputable Dog, Lirael makes her way to The Wall to find Nicholas Sayre lying there unconscious, having woken up a Hrule — a rare free magic creature which drinks blood. From there, they journey to the Clayr's Glacier for further medical attention. At the same time, Ferin of the Athask is racing towards the Clayr's Glacier with an urgent message from Lirael's mother. Chlorr of the Mask is doing everything to stop her, as she brings necromancers together to battle at the Greenwash Bridge. Nicholas is discovered to be capable of acting as a Charter Stone, and so he and Lirael journey to the north in order to send Chlorr of the Mask to her final resting place.

Terciel and Elinor
Bonnier Books UK has signed a deal with Garth Nix for a new novel in the Old Kingdom series and his backlist, marking the first time the series will be housed under one roof in the UK.

The novel was released on November 2, 2021, and follows Sabriel's parents, Terciel and Elinor. Per Publishers Weekly:

Novellas and short stories

The Creature in the Case
The novella The Creature in the Case was published for 2005 World Book Day (HarperCollins Children's Books, March 2005, ). It was retitled "Nicholas Sayre and the Creature in the Case" for collection in Across the Wall: A Tale of the Abhorsen and Other Stories (2005).

According to the publisher, "It is six months since the cataclysmic events of Abhorsen ...". Nicholas Sayre is sent by his Uncle Edward to a party, to observe the workings of a clandestine government organisation responsible for gathering information about the Old Kingdom. The organisation's head, Alastor Dorrance, has covertly obtained a monstrous 'Hrule' and intends to free it across the Wall; and when he attempts to do so, it runs amok, destroying numerous people until pursued by Nicholas to the Wall, where it is rendered harmless by Lirael.

An Extract of the Journal of Idrach the Lesser Necromancer
This short story was distributed by the Old Kingdom series web site and collected in Across the Wall (Allen & Unwin (Australia), 2005).

An Essay on Free Magic
A short text released on the Old Kingdom Website.

To Hold the Bridge
The novella To Hold the Bridge was published in 2010 as part of the anthology Legends of Australian Fantasy, edited by Jack Dann and Jonathan Strahan (HarperCollins Publishers Australia, 2010, ).
It has also been published outside of Australia in a new collection of the author's works, To Hold the Bridge (HarperCollins, 2015, ).

Doctor Crake Crosses the Wall
This short story appears on the Old Kingdom series web site as a bonus feature.

One Wyverley Summer
For the 25th anniversary edition of Sabriel, the short story One Wyverley Summer was included as a bonus feature.

Magic

The Charter and Free Magic

In the Old Kingdom, magic takes two forms: Free Magic or Charter Magic. The former is older, and natural in origin, whereas the latter is imposed (in-universe, by the immortal 'Seven Bright Shiners') as an assurance of order. Some Free Magic remains in the world, mainly in various breeds of monster. The Charter is described as an "endless flow" of symbols describing the cosmos; each used by magicians to achieve psychokinesis. The composition of spells ranges from single Charter marks to long series requiring a 'master mark' and sometimes a physical focus (typically a sword or wand). Though Free Magic is 'corrosive' to living things and Charter Magic, Free Magic spells are required to pass the Gates of Death, and the calls of the Abhorsen's bells are Free Magic spells subject to the Charter. Although the Abhorsen may use Free Magic without suffering long-term ill effects, typical necromancers are ultimately "devoured by the Free Magic they profess to master". Practitioners of Charter Magic have a Charter Mark drawn on their forehead at birth. Marks unsullied by Free Magic are used to identify true Charter Mages (as opposed to Free Magic sorcerers or constructs in disguise).

The Five Great Charters:
In Sabriel, the Five Great Charters are identified by a song:
Five Great Charters knit the land.
Together linked, hand in hand.
One in the people who wear the Crown.
Two in the folk who keep the Dead down.
Three and Five became stone and mortar.
Four sees all in frozen water.

This rhyme dictates that at some point in history the Five Great Charters were concentrated in physical objects, or human bloodlines. The bloodlines are those of the royals, the Abhorsen, the Clayr, and the Wallmakers. After this, the entire Wallmaker line physically became the Great Charter Stones and the Wall that separates the Old Kingdom from Ancelstierre, to prevent contamination of their descent. The Great Charter Stones are located in an underground reservoir in the Old Kingdom's capital, Belisaere, and are the sources of Charter Magic in the Old Kingdom. Under the influence of the Wall, magic, both Free and Charter, exists only in the Old Kingdom; but can be practised in northern Ancelstierre, and further south if there is a strong wind from the Old Kingdom.

Bestiary

Strictly speaking, there are five basic supernatural creatures in the Old Kingdom series:

The Dead: The Dead are ghosts with both the inclination and the ability to resist the river of Death, who re-enter the world of Life. Though a rare few emerge into Life on their own power, most must be summoned by a necromancer or emerge near a broken Charter Stone (where the Charter's influence has been severely diminished, creating a "door into Death"), or where many deaths have recently occurred. All Dead are averse to running water, and most are unable to withstand direct sunlight.

There are two classes of Dead: Lesser and Greater. The Greater Dead are usually represented by Dead from beyond the Fifth Gate (spirits from the deeper realms of Death and correspondingly more powerful). Examples of the Greater Dead include Chlorr of the Mask, Lathal the Abomination (ultimately destroyed by Lirael), and Kerrigor (defeated by Sabriel). Greater Dead, such as Fifth-Gate Resters or Dead Adepts, may exist in Life without a physical body (making them much more difficult to destroy).

The name of Lesser Dead refers to Dead Hands, Ghlims, Mordauts, and Gore Crows: a range of re-embodied spirits, often used by necromancers as weapons. Lesser Dead may be incapacitated by immersing them in running water or by destroying their physical bodies with Charter Magic or explosives; Shadow Hands are impossible to harm by strictly physical means, but may be unraveled by specialized Charter Magic spells or returned to Death by the necromantic bells. Most Dead prey on the living to remain in Life.

Constructs: Free Magic constructs are forms assumed by Free Magic elementals or powerful Dead spirits (such as Kerrigor). Though such constructs may be destroyed, destroying the Elemental itself is much more difficult and typically the province of Free Magic.

Mordicants: These are fiery constructs of clay and blood, animated by Free Magic and guided by a Greater Dead spirit able to move between Life and Death at will. They are fierce combatants, and seem to have enhanced senses, able to track specific targets over hundreds of miles, resisting direct sunlight to do so. The word mordicant comes from a Latin term meaning gnawing.

Free Magic Elementals: These are free-willed beings wholly composed of Free Magic. The most common elementals belong to specific "breeds" (such as Stilken, Magrue, Jerreq, or Hish), while the most powerful are unique, or "of a singular nature". Though "many thousands" of Free Magic Elementals escaped the creation of the Charter, most were later imprisoned or enslaved by it. Of the remainder, "no truly dangerous creature of Free Magic has woken in a thousand years, save to the sound of Mosrael and Saraneth, or by a direct summons using their secret names". Some cannot be destroyed except by a Free Magic sorcerer more powerful than they, or by immersion in running water (though Free Magic creatures of the Third Kindred, or those infused with the essence of the Nine, are exempt from this rule). Charter Magic is typically ineffective.

Charter Sendings: Charter Sendings are servants or sentries constructed entirely of Charter Marks. Many may only act within a given function, which can be of indefinite complexity. Certain fixtures excepted (such as a surcoat or insignia), Charter Sendings do not possess a concrete physical shape, and derive identity primarily from their function. They are capable of emotive response, but show little desire except to fulfill their mandates.

The Bells
The bells of necromancy are seven eponymous bells used by necromancers to control the Dead, named after the Seven Bright Shiners who invested themselves in the Charter. From smallest to largest they are:

Ranna, the Sleeper, prompting drowsiness in the auditor;

Mosrael, the Waker, transmitting the ringer further into Death but the auditor into Life;

Kibeth, the Walker, which can give the Dead freedom of movement or force them to walk according to the ringer's intention;

Dyrim, the Speaker, used either to revive or annul the hearer's ability to speak;

Belgaer, the Thinker, used to restore or remove memory;

Saraneth, the Binder, a favorite of the Abhorsens, used to control the Dead directly; and

Astarael, the Weeper, also named Sorrowful, which sends both ringer and auditor far into Death.

Each bell has a specific power over the Dead and Free Magic creatures, and if used by a skilled necromancer, also on living people. An errant or improper ring can affect the caster instead of the target, or cause other adverse effects. The Abhorsens' bells are a "free-willed blend of Charter and Free Magic", though the spells they cast are "pure Free Magic".

The Nine Bright Shiners

These are the most advanced and powerful Free Magic elementals, of which seven created the Charter and are represented by the necromancers' bells. Of the remaining two, Yrael later became Mogget, the Abhorsens' companion; and Orannis, "last and mightiest of the Nine", opposed the Charter and was imprisoned by the Seven. According to "An Extract of the Journal of Idrach the Lesser Necromancer", a text posted on the series' website, the correlation of the Seven and the necromantic bells includes the Precincts of Death, with each bell equalling a specific Precinct. This would suggest that the additional precincts are related to the 8th and 9th "Bright Shiners", although it is not known which Precinct corresponds to which Bright Shiner.

Because Astarael appears under Abhorsen's House and Kibeth as the Disreputable Dog, it can be inferred that Ranna, Mosrael, Dyrim, Belgaer, and Saraneth became the Five Great Charters. These Great Charters invested themselves entirely within the bloodlines and artifacts of the Old Kingdom, as opposed to Astarael and Kibeth, who retained enough of themselves to remain separate entities (the Disreputable Dog points out that she is only Kibeth in a "hand-me-down sort of way"). It is implied that Saraneth and Mosrael wove themselves into the Abhorsen and Clayr bloodlines respectively. Additionally, Lirael (a "Remembrancer", only made possible by her shared Clayr and Abhorsen heritage) is referred to as "Astarael's get" in The Creature in the Case, and Prince Sameth is referred to as a "Wallmaker" (Ranna and Belgaer) in Abhorsen. Dyrim is considered the Great Charter of the royal bloodline.

Yrael, also known as Mogget, initially refused to take a side for or against Orannis, and was therefore later enslaved to the Abhorsen by the other immortals. Whenever unbound, he tries to kill the current Abhorsen; but, during Orannis' second binding, he assists in the binding ritual. To Sabriel, Lirael, and Sameth, Mogget appears as a small white cat; to Terciel, Sabriel's father and predecessor as Abhorsen, Mogget adopted a different name, Moregrim, and appeared as an albino dwarf. Mogget cannot use his dwarf-form without the permission of the current Abhorsen or Abhorsen-in-Waiting: Jerizael, the forty-eighth Abhorsen, forbade him from doing so for reasons unknown. At the end of the series, he re-appears as a cat.

In Lirael, when Orannis possesses Nicholas Sayre and speaks to the necromancer Hedge, the story of the Binding is told in a song very similar to the English folk song Green Grow the Rushes, O:

I'll sing you a song of the long ago.
Seven shine the Shiners, oh!
What did the Seven do way back when?
Why, they wove the Charter then!
Five for the warp, from beginning to end.
Two for the woof, to make and mend.
That's the Seven, but what of the Nine—
What of the two that chose not to shine?
The Eighth did hide, hide all away,
But the Seven caught him and made him pay.
The Ninth was strong and fought with might,
But lone Orannis was put out of the light,
Broken in two and buried under hill,
Forever to lie there wishing us ill.

Death

Death consists of Nine Precincts divided by Nine Gates, through which a grey river flows. Almost everything in Death is a bleak grey, and a subtle grey fogginess limits visibility. The river may also contain and conceal hostile dead beings, who attack living travelers. Only Abhorsens, Remembrancers, or Free Magic Necromancers can cross the boundary at will. Dead spirits can cross only when aided by a Necromancer, or when the border is weakened by a concentration of (often violent) deaths. Dexterity and great willpower are required to resist the current, which is psychological as well as physical. Each gate responds to a Free Magic spell wielded by Abhorsens and Necromancers; Dead cannot pass any Gate unless they are very powerful. Each Precinct contains a different peril.

The First Precinct is mostly knee-deep water, but has eddies and pools dangerous to the interloper. Its Gate is a huge waterfall.

The Second Precinct has pitfalls throughout its domain and low visibility; its Gate is a whirlpool.

The Third Precinct has slightly warmer ankle-deep water and visibility is slightly improved. Periodic, irresistible waves carry dead creatures through the Gate (a wall of mist), often beyond the final Ninth Gate.

The Fourth Precinct has a low concentration of Dead, as most of those who reach it have been stunned by the Third Precinct's waves, and are carried easily to the dangerous and deceptively short waterfall that comprises its Gate.

The Fifth Precinct is too deep to wade, and must be crossed by a thin black bridge that frequently attracts dead creatures. The water in the Fifth Precinct has strong mutagenic properties, and is implied to be partially responsible for the monstrous appearance of some Greater Dead and necromancers.  The Gate is a vertical river rising from the floor.

The Sixth Precinct has no current, and its water is present as a shallow pool. There are many Dead creatures in this Precinct, some of whom are Greater Dead. The Gate has no substance and can appear anywhere, but appears as a lift bordered by a cylinder of water.

The Seventh Precinct is not described, though presumably it is similar to the First and Fourth Precincts. Its Gate is a line of fire that stretches across the river.

The Eighth Precinct resembles the First and Fourth, but interspersed with flashes of fire. The Eighth Gate is a wall of darkness, which needs a spell to send a necromancer into the Ninth Precinct.

The Ninth Precinct is an endless pool of deep, still, clear water. It is warmer than the other precincts and there is no fog, allowing a necromancer to see in every direction. The Ninth Gate, resembling a starry sky, confirms the final death of any who look upon it, except those to whom remain a native span of years. Those claimed by the Gate rise at varying speeds and vanish, never to return.

People

Abhorsens

The Abhorsens are the lineage who imprison and destroy Dead and Free Magic, wherever it threatens mortal life, though inheritance is not always direct; the next Abhorsen could be a niece or cousin or sibling, rather than the current Abhorsen's child. The Abhorsen combines Charter Magic and Free Magic in its bells to control the dead, righting the wrongs created by Necromancers or Free Magic organisms. The Abhorsens' stronghold, called Abhorsen's House, is located on an island in close proximity to a great waterfall; the associated rapids complement the magical wards of the House in keeping the Dead from accessing it. In Nicholas Sayre and the Creature in the Case, the antagonist Hrule calls them "Astarael's get".
The origin of the name "Abhorsen", according to Garth Nix, is the name of the executioner from Shakespeare's Measure for Measure: "Abhorson".

The Clayr

The Clayr are an oracular group composed nearly entirely of women, who live in a snowy mountain called the Clayr's Glacier, in the northern part of the Old Kingdom. Nearly all are beautiful and possess nut-brown skin, pale blond hair, and eyes of blue or green. The Glacier is also home to the Great Library of the Clayr, which contains a variety of treasures, monsters, and rarities in addition to books. Due to the Clayr's precognitive Sight, there are often rooms created for events which unfold decades or centuries later, including the room in which Lirael discovers her fate.

The Wall Garrison

Soldiers who patrol the wall between the Old Kingdom and Ancelstierre. The soldiers include Ancelstierrean charter mages among their ranks, as charter magic is a more effective defence closer to the Wall and the Old Kingdom.

Southerlings

A group of thousands of refugees from the nations south of Ancelstierre. The necromancer Hedge killed many more of them and used their bodies to house dead spirits. They were referred to as the night crew at the lightning trap digging site.

Places

The Old Kingdom
The Old Kingdom is the setting for most of the series; it corresponds roughly with Scotland. Ancelstierre (analogous to England) and the Old Kingdom travel differently through time, with the hour of the day and the season of the year rarely in synchrony; therefore, it is possible to spend more time in the Old Kingdom than one is absent from Ancelstierre. The Old Kingdom is also the source of all charter magic. The closer a person is to the Old Kingdom, the more easily they can do charter magic. Charter magic is also possible when the wind is blowing from the north, i.e. from the Old Kingdom.

Two hundred years before Sabriel, the reigning Queen and her two daughters were murdered by Kerrigor and their blood used to break two of the six Great Charter Stones. This event was followed by two hundred years of interregnum.

Ancelstierre

It has been suggested, in a question/answer section of Across the Wall: A Tale of the Abhorsen and Other Stories, by the Disreputable Dog (in Lirael), and some online sources that The Old Kingdom and Ancelstierre are two different parallel realities, that overlap slightly at the Wall. The Old Kingdom also has a northern border which is a river gorge, much farther north than The Clayr's Glacier, where it impinges on another world.

Ancelstierre is culturally and technologically based on pre-WWI Britain.

Notes

References

External links

Australian fantasy novels
Australian young adult novels
Fantasy novel trilogies
Young adult novel series
Fictional undead

The Old Kingdom