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Acetosyringone	Chemical characteristics	Acetosyringone does not dissolve well in water. Although it has a melting point of about 125 degree Celsius, it is not wise to autoclave acetosyringone along with the medium used for (for example) plant infiltration by microbes.
Chemical oxygen demand	Chemical oxygen demand	In environmental chemistry, the chemical oxygen demand (COD) is an indicative measure of the amount of oxygen that can be consumed by reactions in a measured solution. It is commonly expressed in mass of oxygen consumed over volume of solution which in SI units is milligrams per litre (mg/L). A COD test can be used to easily quantify the amount of organics in water. The most common application of COD is in quantifying the amount of oxidizable pollutants found in surface water (e.g. lakes and rivers) or wastewater. COD is useful in terms of water quality by providing a metric to determine the effect an effluent will have on the receiving body, much like biochemical oxygen demand (BOD).
Chemical oxygen demand	Overview	The basis for the COD test is that nearly all organic compounds can be fully oxidized to carbon dioxide with a strong oxidizing agent under acidic conditions. The amount of oxygen required to oxidize an organic compound to carbon dioxide, ammonia, and water is given by: CO NH 3 This expression does not include the oxygen demand caused by nitrification, the oxidation of ammonia into nitrate: NH3+2O2→NO3−+H3O+ Dichromate, the oxidizing agent for COD determination, does not oxidize ammonia into nitrate, so nitrification is not included in the standard COD test.
Chemical oxygen demand	Overview	The International Organization for Standardization describes a standard method for measuring chemical oxygen demand in ISO 6060 [1].
Chemical oxygen demand	Using potassium dichromate	Potassium dichromate is a strong oxidizing agent under acidic conditions. Acidity is usually achieved by the addition of sulfuric acid. The reaction of potassium dichromate with organic compounds is given by: Cr CO NH Cr 3+ where d=2n/3+a/6−b/3−c/2 . Most commonly, a 0.25 N solution of potassium dichromate is used for COD determination, although for samples with COD below 50 mg/L, a lower concentration of potassium dichromate is preferred.
Chemical oxygen demand	Using potassium dichromate	In the process of oxidizing the organic substances found in the water sample, potassium dichromate is reduced (since in all redox reactions, one reagent is oxidized and the other is reduced), forming Cr3+. The amount of Cr3+ is determined after oxidization is complete, and is used as an indirect measure of the organic contents of the water sample.
Chemical oxygen demand	Using potassium dichromate	Measurement of excess For all organic matter to be completely oxidized, an excess amount of potassium dichromate (or any oxidizing agent) must be present. Once oxidation is complete, the amount of excess potassium dichromate must be measured to ensure that the amount of Cr3+ can be determined with accuracy. To do so, the excess potassium dichromate is titrated with ferrous ammonium sulfate (FAS) until all of the excess oxidizing agent has been reduced to Cr3+. Typically, the oxidation-reduction indicator ferroin is added during this titration step as well. Once all the excess dichromate has been reduced, the ferroin indicator changes from blue-green to a reddish brown. The amount of ferrous ammonium sulfate added is equivalent to the amount of excess potassium dichromate added to the original sample. Note: Ferroin indicator is bright red from commercially prepared sources, but when added to a digested sample containing potassium dichromate it exhibits a green hue. During the titration the color of the indicator changes from a green hue to a bright blue hue to a reddish brown upon reaching the endpoint. Ferroin indicator changes from red to pale blue when oxidized.
Chemical oxygen demand	Preparation of ferroin indicator reagent	A solution of 1.485 g 1,10-phenanthroline monohydrate is added to a solution of 695 mg FeSO4·7H2O in distilled water, and the resulting red solution is diluted to 100 mL. Calculations The following formula is used to calculate COD: 8000 sample volume where b is the volume of FAS used in the blank sample, s is the volume of FAS in the original sample, and n is the normality of FAS. If milliliters are used consistently for volume measurements, the result of the COD calculation is given in mg/L.
Chemical oxygen demand	Preparation of ferroin indicator reagent	The COD can also be estimated from the concentration of oxidizable compound in the sample, based on its stoichiometric reaction with oxygen to yield CO2 (assume all C goes to CO2), H2O (assume all H goes to H2O), and NH3 (assume all N goes to NH3), using the following formula: COD = (C/FW)·(RMO)·32Where C = Concentration of oxidizable compound in the sample, FW = Formula weight of the oxidizable compound in the sample, RMO = Ratio of the # of moles of oxygen to # of moles of oxidizable compound in their reaction to CO2, water, and ammoniaFor example, if a sample has 500 Wppm (Weight Parts per Million) of phenol: C6H5OH + 7O2 → 6CO2 + 3H2OCOD = (500/94)·7·32 = 1191 Wppm
Chemical oxygen demand	Inorganic interference	Some samples of water contain high levels of oxidizable inorganic materials which may interfere with the determination of COD. Because of its high concentration in most wastewater, chloride is often the most serious source of interference. Its reaction with potassium dichromate follows the equation: 14 H+→3Cl2+2Cr3++7H2O Prior to the addition of other reagents, mercuric sulfate can be added to the sample to eliminate chloride interference.
Chemical oxygen demand	Inorganic interference	The following table lists a number of other inorganic substances that may cause interference. The table also lists chemicals that may be used to eliminate such interference, and the compounds formed when the inorganic molecule is eliminated.
Chemical oxygen demand	Government regulation	Many governments impose strict regulations regarding the maximum chemical oxygen demand allowed in waste water before they can be returned to the environment. For example, in Switzerland, a maximum oxygen demand between 200 and 1000 mg/L must be reached before waste water or industrial water can be returned to the environment [2].
Chemical oxygen demand	History	For many years, the strong oxidizing agent potassium permanganate (KMnO4) was used for measuring chemical oxygen demand. Measurements were called oxygen consumed from permanganate, rather than the oxygen demand of organic substances. Potassium permanganate's effectiveness at oxidizing organic compounds varied widely, and in many cases biochemical oxygen demand (BOD) measurements were often much greater than results from COD measurements. This indicated that potassium permanganate was not able to effectively oxidize all organic compounds in water, rendering it a relatively poor oxidizing agent for determining COD.
Chemical oxygen demand	History	Since then, other oxidizing agents such as ceric sulphate, potassium iodate, and potassium dichromate have been used to determine COD. Of these, potassium dichromate (K2Cr2O7) has been shown to be the most effective: it is relatively cheap, easy to purify, and is able to nearly completely oxidize almost all organic compounds.
Chemical oxygen demand	History	In these methods, a fixed volume with a known excess amount of the oxidant is added to a sample of the solution being analyzed. After a refluxing digestion step, the initial concentration of organic substances in the sample is calculated from a titrimetric or spectrophotometric determination of the oxidant still remaining in the sample. As with all colorimetric methods blanks are used to control for contamination by outside material.
Object relations theory	Object relations theory	Object relations theory is a school of thought in psychoanalytic theory and psychoanalysis centered around theories of stages of ego development. Its concerns include the relation of the psyche to others in childhood and the exploration of relationships between external people, as well as internal images and the relations found in them. Thinkers of the school maintain that the infant's relationship with the mother primarily determines the formation of its personality in adult life. Particularly, attachment is the bedrock of the development of the self or the psychic organization that creates the sense of identity.
Object relations theory	Theory	While its groundwork derives from theories of development of the ego in Freudian psychodynamics, object relations theory does not place emphasis on the role of biological drives in the formation of personality in adulthood. Thinkers of the school instead suggest that the way people relate to others and situations in their adult lives is shaped by family experiences during infancy; an adult who experienced neglect or abuse in infancy expects similar behavior from others who, through transference, remind them of the neglectful or abusive parent from their past. These patterns of the behavior of people become repeated images of the events, and eventually turn into objects in the unconscious that the self carries into adulthood to be used in the unconscious to predict people's behavior in their social relationships and interactions.
Object relations theory	Theory	The first "object" in an individual is usually an internalized image of the mother. Internal objects are formed by the patterns in one's experience of being taken care of as a baby, which may or may not be accurate representations of the actual, external caretakers. Objects are usually internalized images of one's mother, father, or primary caregiver, although they could also consist of parts of a person such as an infant relating to the breast or things in one's inner world (one's internalized image of others).
Object relations theory	Theory	Later experiences can reshape these early patterns, but objects often continue to exert a strong influence throughout life. Objects are initially comprehended in the infant mind by their functions and are termed part objects. The breast that feeds the hungry infant is the "good breast", while a hungry infant that finds no breast is in relation to the "bad breast". With a "good enough" facilitating environment, part object functions eventually transform into a comprehension of whole objects. This corresponds with the ability to tolerate ambiguity, to see that both the "good" and the "bad" breast are a part of the same mother figure.
Object relations theory	History	The initial line of thought emerged in 1917 with Sándor Ferenczi and, early in the 1930s, Harry Stack Sullivan, coiner of the term "interpersonal". British psychologists Melanie Klein, Donald Winnicott, Harry Guntrip, Scott Stuart, and others extended object relations theory during the 1940s and 1950s; in 1952, Ronald Fairbairn formulated his theory of object relations.The term has been used in many different contexts, which led to different connotations and denotations. While Fairbairn popularized the term "object relations", Melanie Klein's work tends to be most commonly identified with the terms "object relations theory" and "British object relations", at least in contemporary North America, though the influence of the British Independent Group—which argued that the primary motivation of the child is object seeking rather than drive gratification—is becoming increasingly recognized. Klein felt that the psychodynamic battleground that Freud proposed occurs very early in life, during infancy. Furthermore, its origins are different from those that Freud proposed. The interactions between infant and mother are so deep and intense that they form the focus of the infant's structure of drives. Some of these interactions provoke anger and frustration; others provoke strong emotions of dependence as the child begins to recognize the mother is more than a breast from which to feed. These reactions threaten to overwhelm the individuality of the infant. The way in which the infant resolves the conflict, Klein believed, is reflected in the adult's personality.Sigmund Freud originally identified people in a subject's environment with the term "object" to identify people as the object of drives. Fairbairn took a radical departure from Freud by positing that humans were not seeking satisfaction of the drive, but actually seek the satisfaction that comes in being in relation to real others. Klein and Fairbairn were working along similar lines, but unlike Fairbairn, Klein always held that she was not departing from Freudian theory, but simply elaborating early developmental phenomena consistent with Freudian theory.
Object relations theory	History	Within the London psychoanalytic community, a conflict of loyalties took place between Klein and object relations theory (sometimes referred to as "id psychology"), and Anna Freud and ego psychology. In America, Anna Freud heavily influenced American psychoanalysis in the 1940s, 1950s, and 1960s. American ego psychology was furthered in the works of Hartmann, Kris, Loewenstein, Rapaport, Erikson, Jacobson, and Mahler. In London, those who refused to choose sides were termed the "middle school," whose members included Michael Balint and D.W. Winnicott. A certain division developed in England between the school of Anna Freud and that of Melanie Klein, which later influenced psychoanalytic politics worldwide. Klein was popularized in South America while A. Freud garnered an American allegiance.
Object relations theory	History	Fairbairn's theory of attachment Fairbairn identified how people who were abused as children internalize that experience; the "moral defense" is the tendency seen in survivors of abuse to take all the bad upon themselves, each yielding the moral evil so the caretaker-object can be regarded as good. This is a use of splitting as a defense to maintain an attachment relationship in an unsafe world. In one particular example of this circumstance, Fairbairn introduced a four-year-old girl who had suffered a broken arm from her mother to a doctor friend of his, who told the little girl that they were going to find her a new parent. The girl, now panicked and unhappy, replied that she wanted her "real mommy", before Fairbairn asked "You mean the mommy that broke your arm?" "I was bad," the girl replied; from this exchange, he theorized that she needed to believe that her love object (mother) was entirely good to firmly believe she would one day receive the love and nurturing she needed—in an attempt to recuperate these needs, she used the moral defense to make herself bad in order to preserve her mother's goodness.
Object relations theory	Kleinian object relations theory	Unconscious phantasy Klein termed the psychological aspect of instinct unconscious phantasy (deliberately spelled with 'ph' to distinguish it from the word 'fantasy'). Phantasy is a given of psychic life which moves outward towards the world. These image-potentials are given a priority with the drives and eventually allow the development of more complex states of mental life. Unconscious phantasy in the infant's emerging mental life is modified by the environment as the infant has contact with reality.
Object relations theory	Kleinian object relations theory	From the moment the infant starts interacting with the outer world, he is engaged in testing his phantasies in a reality setting. I want to suggest that the origin of thought lies in this process of testing phantasy against reality; that is, that thought is not only contrasted with phantasy, but based on it and derived from it.: 45 The role of unconscious phantasy is essential in the development of a capacity for thinking. In Bion's terms, the phantasy image is a preconception that will not be a thought until experience combines with a realization in the world of experience. The preconception and realization combine to take form as a concept that can be thought. The classic example of this is the infant's observed rooting for the nipple in the first hours of life. The instinctual rooting is the preconception. The provision of the nipple provides the realization in the world of experience, and through time, with repeated experience, the preconception and realization combined to create the concept. Mental capacity builds upon previous experience as the environment and infant interact.
Object relations theory	Kleinian object relations theory	The first bodily experiences begin to build up the first memories, and external realities are progressively woven into the texture of phantasy. Before long, the child's phantasies are able to draw upon plastic images as well as sensations—visual, auditory, kinæsthetic, touch, taste, smell images, etc. And these plastic images and dramatic representations of phantasy are progressively elaborated along with articulated perceptions of the external world.
Object relations theory	Kleinian object relations theory	With adequate care, the infant is able to tolerate increasing awareness of experience which is underlain by unconscious phantasy and leads to attainment of consecutive developmental achievements, "the positions" in Kleinian theory.
Object relations theory	Kleinian object relations theory	Projective identification As a specific term, projective identification is introduced by Klein in "Notes on some schizoid mechanisms." [Projection] helps the ego to overcome anxiety by ridding it of danger and badness. Introjection of the good object is also used by the ego as a defense against anxiety. . . .The processes of splitting off parts of the self and projecting them into objects are thus of vital importance for normal development as well as for abnormal object-relation. The effect of introjection on object relations is equally important. The introjection of the good object, first of all the mother's breast, is a precondition for normal development . . . It comes to form a focal point in the ego and makes for cohesiveness of the ego. . . . I suggest for these processes the term 'projective identification'.: 6–9 Klein imagined this function as a defense which contributes to the normal development of the infant, including ego structure and the development of object relations. The introjection of the good breast provides a location where one can hide from persecution, an early step in developing a capacity to self-soothe.
Object relations theory	Kleinian object relations theory	Ogden identifies four functions that projective identification may serve. As in the traditional Kleinian model, it serves as a defense. Projective identification serves as a mode of communication. It is a form of object relations, and "a pathway for psychological change.": 21 As a form of object relationship, projective identification is a way of relating with others who are not seen as entirely separate from the individual. Instead, this relating takes place "between the stage of the subjective object and that of true object relatedness".: 23 The paranoid-schizoid and depressive positions The positions of Kleinian theory, underlain by unconscious phantasy, are stages in the normal development of ego and object relationships, each with its own characteristic defenses and organizational structure. The paranoid-schizoid and depressive positions occur in the pre-oedipal, oral phase of development.
Object relations theory	Kleinian object relations theory	In contrast to Fairbairn and later Guntrip, Klein believed that both good and bad objects are introjected by the infant, the internalization of good objects being essential to the development of healthy ego function.: 4 Klein conceptualized the depressive position as "the most mature form of psychological organization", which continues to develop throughout the life span.: 11 The depressive position occurs during the second quarter of the first year.: 14 Prior to that the infant is in the paranoid-schizoid position, which is characterized by persecutory anxieties and the mechanisms of splitting, projection, introjection, and omnipotence—which includes idealizing and denial—to defend against these anxieties.: 7 Depressive and paranoid-schizoid modes of experience continue to intermingle throughout the first few years of childhood.
Object relations theory	Kleinian object relations theory	Paranoid-schizoid position The paranoid-schizoid position is characterized by part object relationships. Part objects are a function of splitting, which takes place in phantasy. At this developmental stage, experience can only be perceived as all good or all bad. As part objects, it is the function that is identified by the experiencing self, rather than whole and autonomous others. The hungry infant desires the good breast who feeds it. Should that breast appear, it is the good breast. If the breast does not appear, the hungry and now frustrated infant, in its distress, has destructive phantasies dominated by oral aggression towards the bad, hallucinated breast.: 5 Klein notes that in splitting the object, the ego is also split.: 6 The infant who phantasies destruction of the bad breast is not the same infant that takes in the good breast, at least not until obtaining the depressive position, at which point good and bad can be tolerated simultaneously in the same person and the capacity for remorse and reparation ensue.
Object relations theory	Kleinian object relations theory	The anxieties of the paranoid schizoid position are of a persecutory nature, fear of the ego's annihilation.: 33 Splitting allows good to stay separate from bad. Projection is an attempt to eject the bad in order to control through omnipotent mastery. Splitting is never fully effective, according to Klein, as the ego tends towards integration.: 34 Depressive position Klein saw the depressive position as an important developmental milestone that continues to mature throughout the life span. The splitting and part object relations that characterize the earlier phase are succeeded by the capacity to perceive that the other who frustrates is also the one who gratifies. Schizoid defenses are still in evidence, but feelings of guilt, grief, and the desire for reparation gain dominance in the developing mind.
Object relations theory	Kleinian object relations theory	In the depressive position, the infant is able to experience others as whole, which radically alters object relationships from the earlier phase.: 3 "Before the depressive position, a good object is not in any way the same thing as a bad object. It is only in the depressive position that polar qualities can be seen as different aspects of the same object.": 37 Increasing nearness of good and bad brings a corresponding integration of ego.
Object relations theory	Kleinian object relations theory	In a development which Grotstein terms the "primal split",: 39 the infant becomes aware of separateness from the mother. This awareness allows guilt to arise in response to the infant's previous aggressive phantasies when bad was split from good. The mother's temporary absences allow for continuous restoration of her "as an image of representation" in the infant mind.: 39 Symbolic thought may now arise, and can only emerge once access to the depressive position has been obtained. With the awareness of the primal split, a space is created in which the symbol, the symbolized, and the experiencing subject coexist. History, subjectivity, interiority, and empathy all become possible.: 14 The anxieties characteristic of the depressive position shift from a fear of being destroyed to a fear of destroying others. In fact or phantasy, one now realizes the capacity to harm or drive away a person who one ambivalently loves. The defenses characteristic of the depressive position include the manic defenses, repression and reparation. The manic defenses are the same defenses evidenced in the paranoid-schizoid position, but now mobilized to protect the mind from depressive anxiety. As the depressive position brings about an increasing integration in the ego, earlier defenses change in character, becoming less intense and allowing for an increased awareness of psychic reality.: 73 In working through depressive anxiety, projections are withdrawn, allowing the other more autonomy, reality, and a separate existence.: 16 The infant, whose destructive phantasies were directed towards the bad mother who frustrated, now begins to realize that bad and good, frustrating and satiating, it is always the same mother. Unconscious guilt for destructive phantasies arises in response to the continuing love and attention provided by caretakers.
Object relations theory	Kleinian object relations theory	[As] fears of losing the loved one become active, a very important step is made in the development. These feelings of guilt and distress now enter as a new element into the emotion of love. They become an inherent part of love, and influence it profoundly both in quality and quantity.: 65 From this developmental milestone comes a capacity for sympathy, responsibility to and concern for others, and an ability to identify with the subjective experience of people one cares about.: 65–66 With the withdrawal of the destructive projections, repression of the aggressive impulses takes place.: 72–73 The child allows caretakers a more separate existence, which facilitates increasing differentiation of inner and outer reality. Omnipotence is lessened, which corresponds to a decrease in guilt and the fear of loss.: 16 When all goes well, the developing child is able to comprehend that external others are autonomous people with their own needs and subjectivity.
Object relations theory	Kleinian object relations theory	Previously, extended absences of the object (the good breast, the mother) was experienced as persecutory, and, according to the theory of unconscious phantasy, the persecuted infant phantisizes destruction of the bad object. The good object who then arrives is not the object which did not arrive. Likewise, the infant who destroyed the bad object is not the infant who loves the good object.
Object relations theory	Kleinian object relations theory	In phantasy, the good internal mother can be psychically destroyed by the aggressive impulses. It is crucial that the real parental figures are around to demonstrate the continuity of their love. In this way, the child perceives that what happens to good objects in phantasy does not happen to them in reality. Psychic reality is allowed to evolve as a place separate from the literalness of the physical world.
Object relations theory	Kleinian object relations theory	Through repeated experience with good enough parenting, the internal image that the child has of external others, that is the child's internal object, is modified by experience and the image transforms, merging experiences of good and bad which becomes more similar to the real object (e.g. the mother, who can be both good and bad). In Freudian terms, the pleasure principle is modified by the reality principle.
Object relations theory	Kleinian object relations theory	Melanie Klein saw this surfacing from the depressive position as a prerequisite for social life. Moreover, she viewed the establishment of an inside and an outside world as the start of interpersonal relationships.
Object relations theory	Kleinian object relations theory	Klein argued that people who never succeed in working through the depressive position in their childhood will, as a result, continue to struggle with this problem in adult life. For example: the cause that a person may maintain suffering from intense guilt feelings over the death of a loved one, may be found in the unworked- through depressive position. The guilt is there because of a lack of differentiation between phantasy and reality. It also functions as a defense mechanism to defend the self against unbearable feelings of sadness and sorrow, and the internal object of the loved one against the unbearable rage of the self, which, it is feared, could destroy the internal object forever.
Object relations theory	Kleinian object relations theory	Further thinking regarding the positions Wilfred Bion articulates the dynamic nature of the positions, a point emphasised by Thomas Ogden, and expanded by John Steiner in terms of '"The equilibrium between the paranoid-schizoid and the depressive positions"'. Ogden and James Grotstein have continued to explore early infantile states of mind, and incorporating the work of Donald Meltzer, Esther Bick and others, postulate a position preceding the paranoid-schizoid. Grotstein, following Bion, also hypothesizes a transcendent position which emerges following attainment of the depressive position. This aspect of both Ogden and Grotstein's work remains controversial for many within classical object relations theory.
Object relations theory	Kleinian object relations theory	Death drive Sigmund Freud developed the concept object relation to describe or emphasize that bodily drives satisfy their need through a medium, an object, on a specific focus. The central thesis in Melanie Klein's object relations theory was that objects play a decisive role in the development of a subject and can be either part-objects or whole-objects, i.e. a single organ (a mother's breast) or a whole person (a mother). Consequently, both a mother or just the mother's breast can be the focus of satisfaction for a drive. Furthermore, according to traditional psychoanalysis, there are at least two types of drives, the libido (mythical counterpart: Eros), and the death drive, mortido (mythical counterpart: Thanatos). Thus, the objects can be receivers of both love and hate, the affective effects of the libido and the death drive.
Object relations theory	Ronald Fairbairn's model of object relations theory	Fairbairn was impressed with the work of Klein, particularly in her emphasis on internalized objects, but he objected to the notion that internalization of external objects was based on death instinct. The death instinct is a remnant of the Freudian model that was emphasized in Klein's model, and her model assumes that human behavior is motivated by a struggle between the instinctual forces of love and hate. Klein believed that each human being was born with a inborn death instinct which motivated the child to imagine hurting their mother during the schizoid period of development. The child attempts to protect themselves from becoming overwhelmed by hate by internalizing, or taking into themselves, memories of the loving aspects of their parents to counteract the hateful components. Fairbairn's model also emphasized the internalization of external objects, but his view of internalization was not based on instinctual drive, but rather the child's normal desire to understand the world around him.
Object relations theory	Ronald Fairbairn's model of object relations theory	Fairbairn began his theory with his observation of the child's absolute dependency on the good will of its mother. The infant, Fairbairn noted, was dependent on its maternal object (or caretaker) for providing him with all of his physical and psychological needs as noted in the following passage.The outstanding feature of infantile dependence is its unconditional character. The infant is completely dependent upon its object not only for his existence and physical well being, but also for the satisfaction of his psychological needs...In contrast, the very helplessness of the child is sufficient to render him dependent in an unconditional sense...He has no alternative but to accept or reject his object- an alternative that is liable to present itself to him as a choice between life and death (Fairbairn, 1952, 47) When the maternal object provides a sense of safety and warmth, the child's innate "central ego" is able to take in new experiences which allows him to expand his contact with the environment beyond the tight orbit of his mother. This is the beginning of the process of differentiation, or separation from the parent, which eventuates into a new and unique individual. As long as the maternal object continues to provide emotional warmth, support, and a sense of safety, the child will continue to develop throughout childhood. However, if the parent fails to consistently provide these factors, the child's development stops and he regresses and remains undifferentiated from his mother, as the following quote illustrates.The greatest need of a child is to obtain conclusive assurance (a) that he is genuinely loved as a person by his parents, and (b) that his parents genuinely accept his love. It is only in so far as such assurance is forthcoming in a form sufficiently convincing to enable him to depend safely upon his real objects that he is able to gradually renounce infantile dependence without misgiving. In the absence of such assurance his relationship with his objects is fraught with too much anxiety over separation to enable him to renounce the attitude of infantile dependence: for such a renunciation would be equivalent in his eyes to forfeiting all hope of ever obtaining the satisfaction of his unsatisfied emotional needs. Frustration of his desire to be loved as a person and have his love accepted is the greatest trauma that a child can experience (Fairbairn, 1952:39-40). This quote illustrates the basis of Fairbairn's model. It is completely interpersonal in that there are no biological drives of inherited instincts. The child is born with a need for love and safety, and when his interpersonal environment fails him, he stops developing psychologically and emotionally. The counterintitutive result of maternal (or paternal, if the father is the primary caregiver) failure is that the child becomes more, rather than less, dependent upon her, because by failing to meet her child's needs the child has to remain dependent in the hope that love and support will be forthcoming in the future. Over time, the failed support of the child's developmental needs leaves him further and further behind his similarly aged peers. The emotionally abandoned child must turn to his own resources for comfort, and turns to his inner world with its readily available fantasies, in an attempt to partially meet his needs for comfort, love and later, for success. Often these fantasies involve others figures who have been self-created. Fairbairn noted that the child's turn toward his inner world protected him from the harsh reality of his family environment, but turned him away from external reality. "All represent relationships with internalized objects, to which the individual is compelled to turn in default of satisfactory relationships in the outer world (Fairbairn, 1952, 40 italics in the original).
Object relations theory	Ronald Fairbairn's model of object relations theory	Fairbairn's Structural Theory Fairbairn realized that the child's absolute dependence on the good will of his mother made him intolerant of accepting or even acknowledging that he is being abused because that would weaken his necessary attachment to his parent. The child creates a delusion that he in a lives warm cocoon of love, and any information that interferes with this delusion is forcibly expelled from his consciousness, as he cannot face the terror of rejection or abandonment at three, four or five years of age. The defense that children use to maintain their sense of security is dissociation, and they force all memories of parental failures (neglect, indifference or emotional abandonments) into their unconscious. Over time the neglected child develops an ever expanding memory bank of event after event in which he was neglected. These dissociated interpersonal events are always in pairs, a self in relationship to an object. For example, a child who is neglected dissociates a memory of himself as a frightened confused self who has been neglected by a remote and indifferent parent. If these events are repeated again and again, the child's unconscious groups the memories into a view of the self and a view of the parent, both which are too toxic and upsetting to be allow into consciousness. The paired dissociations of self and object that accrued from rejections were called the antilibidinal ego (the child's frightened self) and the rejecting object (the indifferent or absent parent). Thus, in addition to the conscious central ego, which relates to the nurturing and supportive parts of the parent (called the ideal object), the child has a second view of self and object in his unconscious: the antilibidinal ego and the rejecting object. No child can live in a world devoid of hope for the future. Fairbairn had a part time position in an orphanage, where he saw neglected and abused children. He noticed that they created fantasies about the "goodness" of their parents and eagerly looked forward to being reunited with them. He realized that these children had dissociated and repressed the many physical and emotional outrages that they had been subjected to in the family. Once in the orphanage, these same children lived in a fantasy world of hope and expectation, which prevented them from psychological collapse. The fantasy self that the child develops was called the libidinal self (or libidinal ego) and it related to the very best parts of the parents, who may have shown interest or tenderness toward their child at one time or another, which the needy child then enhances with fantasy. The fantasy enhanced view of the parent was called the exciting object by Fairbairn, which was based on the excitement of the child as he spun his fantasy of a reunion with his loving parents. This pair of self and objects is also contained in the child's unconscious, but he may call them into awareness when he is desperate for comfort and support (Fairbairn, 1952, 102-119)Fairbairn's structural model contains three selves that relate to three aspects of the object. The selves do not know or relate to each other, and the process of dissociation and the development of these structures is called the splitting defense, or splitting. The child's central ego relates to the Ideal object when the parent is supportive and nurturant. The antilibidinal ego relates only to the rejecting object, and these structures contain the child's fear and anger as well as the parent's indifference, neglect or outright abuse.
Object relations theory	Ronald Fairbairn's model of object relations theory	The libidinal ego relates only to the exciting object, and these structures contain the overly hopeful child who relates to the exciting over-promising parent. The Fairbairnian object relations therapist imagines that all interactions between the client and the therapist are occurring in the client's inner object relations world, in one of the three dyads. The Fairbairnian object relations therapist also uses his/her own emotional reactions as therapeutic cues. If the therapist is feeling irritated at the client, or bored, he/she might interpret that as a re-enactment of the Antilibidinal Ego and the Bad Object, with the therapist cast in the role of Bad Object. If the therapist can patiently be an empathic therapist through the client's re-enactment, then the client has a new experience to incorporate into their inner object world, hopefully expanding their inner picture of their Good Object. Cure is seen as the client being able to receive from their inner Good Object often enough to have a more stable peaceful life.Numerous research studies have found that most all models of psychotherapy are equally helpful, the difference mainly being the quality of the individual therapist, not the theory the therapist subscribes to. Object Relations Theory attempts to explain this phenomenon via the theory of the Good Object. If a therapist can be patient and empathic, most clients improve their functioning in their world. The client carries with them a picture of the empathic therapist that helps them cope with the stressors of daily life, regardless of what theory of psychology they subscribe to.
Object relations theory	Continuing developments in the theory	Attachment theory, researched by John Bowlby and others, has continued to deepen our understanding of early object relationships. While a different strain of psychoanalytic theory and research, the findings in attachment studies have continued to support the validity of the developmental progressions described in object relations. Recent decades in developmental psychological research, for example on the onset of a "theory of mind" in children, has suggested that the formation of the mental world is enabled by the infant-parent interpersonal interaction which was the main thesis of British object-relations tradition (e.g. Fairbairn, 1952).
Object relations theory	Continuing developments in the theory	While object relations theory grew out of psychoanalysis, it has been applied to the general fields of psychiatry and psychotherapy by such authors as N. Gregory Hamilton and Glen O. Gabbard. In making object relations theory more useful as a general psychology N. Gregory Hamilton added the specific ego functions to Otto F. Kernberg's concept of object relations units.
NDUFA6	NDUFA6	NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 6 is an enzyme that in humans is encoded by the NDUFA6 gene. The NDUFA6 protein is a subunit of NADH dehydrogenase (ubiquinone), which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain.
NDUFA6	Structure	The NDUFA6 gene is located on the q arm of chromosome 22 in position 13.2 and spans 5,359 base pairs. The gene produces an 18 kDa protein composed of 154 amino acids. NDUFA6 is a subunit of the enzyme NADH dehydrogenase (ubiquinone), the largest of the respiratory complexes. The structure is L-shaped with a long, hydrophobic transmembrane domain and a hydrophilic domain for the peripheral arm that includes all the known redox centers and the NADH binding site. It has been noted that the N-terminal hydrophobic domain has the potential to be folded into an alpha helix spanning the inner mitochondrial membrane with a C-terminal hydrophilic domain interacting with globular subunits of Complex I. The highly conserved two-domain structure suggests that this feature is critical for the protein function and that the hydrophobic domain acts as an anchor for the NADH dehydrogenase (ubiquinone) complex at the inner mitochondrial membrane. NDUFA6 is one of about 31 hydrophobic subunits that form the transmembrane region of Complex I. The predicted secondary structure is primarily alpha helix, but the carboxy-terminal half of the protein has high potential to adopt a coiled-coil form. The amino-terminal part contains a putative beta sheet rich in hydrophobic amino acids that may serve as mitochondrial import signal. Related pseudogenes have also been identified on four other chromosomes.
NDUFA6	Function	The human NDUFA6 gene codes for a subunit of Complex I of the respiratory chain, which transfers electrons from NADH to ubiquinone. Initially, NADH binds to Complex I and transfers two electrons to the isoalloxazine ring of the flavin mononucleotide (FMN) prosthetic arm to form FMNH2. The electrons are transferred through a series of iron-sulfur (Fe-S) clusters in the prosthetic arm and finally to coenzyme Q10 (CoQ), which is reduced to ubiquinol (CoQH2). The flow of electrons changes the redox state of the protein, resulting in a conformational change and pK shift of the ionizable side chain, which pumps four hydrogen ions out of the mitochondrial matrix.
Swimming	Swimming	Swimming is the self-propulsion of a person through water, or other liquid, usually for recreation, sport, exercise, or survival. Locomotion is achieved through coordinated movement of the limbs and the body to achieve hydrodynamic thrust that results in directional motion. Humans can hold their breath underwater and undertake rudimentary locomotive swimming within weeks of birth, as a survival response.Swimming is consistently among the top public recreational activities, and in some countries, swimming lessons are a compulsory part of the educational curriculum. As a formalized sport, swimming is featured in a range of local, national, and international competitions, including every modern Summer Olympics.
Swimming	Swimming	Swimming involves repeated motions known as strokes in order to propel the body forward. While the front crawl, also known as freestyle, is widely regarded as the fastest out of four primary strokes, other strokes are practiced for special purposes, such as for training.
Swimming	Swimming	There are various risks present during swimming, mainly due to it taking place in water. Swimmers are at risk of incapacitation due to panic and exhaustion, which may cause death due to drowning. Other dangers include getting an infection or contact with hostile aquatic fauna. To minimize these risks, most facilities employ a lifeguard to look for signs of distress.
Swimming	Swimming	Swimmers often wear specialized swimwear, although depending on the culture of the area, some swimmers may also swim nude or wear their day attire. In addition to this, a variety of equipment can be used to enhance the swimming experience or performance, including but not limited to the use of swimming goggles, floatation devices, swim fins, and snorkels.
Swimming	Science	Swimming relies on the nearly neutral buoyancy of the human body. On average, the body has a relative density of 0.98 compared to water, which causes the body to float. However, buoyancy varies on the basis of body composition, lung inflation, muscle and fat content, centre of gravity and the salinity of the water. Higher levels of body fat and saltier water both lower the relative density of the body and increase its buoyancy. Human males tend to have a lower centre of gravity and higher muscle content, therefore find it more difficult to float or be buoyant. See also: Hydrostatic weighing. Since the human body is less dense than water, water is able to support the weight of the body during swimming. As a result, swimming is "low-impact" compared to land activities such as running. The density and viscosity of water also create resistance for objects moving through the water. Swimming strokes use this resistance to create propulsion, but this same resistance also generates drag on the body.
Swimming	Science	Hydrodynamics is important to stroke technique for swimming faster, and swimmers who want to swim faster or exhaust less try to reduce the drag of the body's motion through the water. To be more hydrodynamically effective, swimmers can either increase the power of their strokes or reduce water resistance, though power must increase by a factor of three to achieve the same effect as reducing resistance. Efficient swimming by reducing water resistance involves a horizontal water position, rolling the body to reduce the breadth of the body in the water, and extending the arms as far as possible to reduce wave resistance.Just before plunging into the pool, swimmers may perform exercises such as squatting. Squatting helps in enhancing a swimmer's start by warming up the thigh muscles.
Swimming	Infant swimming	Human babies demonstrate an innate swimming or diving reflex from newborn until the age of approximately 6 months. Other mammals also demonstrate this phenomenon (see mammalian diving reflex). The diving response involves apnea, reflex bradycardia, and peripheral vasoconstriction; in other words, babies immersed in water spontaneously hold their breath, slow their heart rate, and reduce blood circulation to the extremities (fingers and toes).
Swimming	Infant swimming	Because infants are innately able to swim, classes for babies of about 6 months old are offered in many locations. This helps build muscle memory and makes strong swimmers from a young age.
Swimming	Technique	Swimming can be undertaken using a wide range of styles, known as 'strokes,' and these strokes are used for different purposes, or to distinguish between classes in competitive swimming. It is not necessary to use a defined stroke for propulsion through the water, and untrained swimmers may use a 'doggy paddle' of arm and leg movements, similar to the way four-legged animals swim.
Swimming	Technique	There are four main strokes used in competition and recreation swimming: the front crawl, also known as freestyle, breaststroke, backstroke and butterfly. Competitive swimming in Europe started around 1800, mostly using the breaststroke. In 1873, John Arthur Trudgen introduced the trudgen to Western swimming competitions. Butterfly was developed in the 1930s, and was considered a variant of the breaststroke until accepted as a separate style in 1953. Butterfly is considered the hardest stroke by many people, but it is the most effective for all-around toning and the building of muscles. It also burns the most calories and can be the second fastest stroke if practiced regularly.In non-competitive swimming, there are some swimming strokes including sidestroke. The sidestroke toward the end of the 19th century, this pattern was changed by raising one arm above the water first, then the other, and then each in turn. It is still used in lifesaving and recreational swimming.
Swimming	Technique	Other strokes exist for particular reasons such as training, school lessons, and rescue, and it is often possible to change strokes to avoid using parts of the body, either to separate specific body parts, such as swimming with only arms or legs to exercise them harder, or for amputees or those affected by paralysis.
Swimming	History	Swimming has been recorded since prehistoric times, and the earliest records of swimming date back to Stone Age paintings from around 7,000 years ago. Written references date from 2000 BC. Some of the earliest references include the Epic of Gilgamesh, the Iliad, the Odyssey, the Bible (Ezekiel 47:5, Acts 27:42, Isaiah 25:11), Beowulf, and other sagas.
Swimming	History	The coastal tribes living in the volatile Low Countries were known as excellent swimmers by the Romans. Men and horses of the Batavi tribe could cross the Rhine without losing formation, according to Tacitus. Dio Cassius describes one surprise tactic employed by Aulus Plautius against the Celts at the Battle of the Medway: The [British Celts] thought that Romans would not be able to cross it without a bridge, and consequently bivouacked in rather careless fashion on the opposite bank; but he sent across a detachment of [Batavii], who were accustomed to swim easily in full armour across the most turbulent streams. ... Thence the Britons retired to the river Thames at a point near where it empties into the ocean and at flood-tide forms a lake. This they easily crossed because they knew where the firm ground and the easy passages in this region were to be found, but the Romans in attempting to follow them were not so successful. However, the [Batavii] swam across again and some others got over by a bridge a little way up-stream, after which they assailed the barbarians from several sides at once and cut down many of them.
Swimming	History	In 1538, Nikolaus Wynmann, a Swiss–German professor of languages, wrote the earliest known complete book about swimming, Colymbetes, sive de arte natandi dialogus et festivus et iucundus lectu (The Swimmer, or A Dialogue on the Art of Swimming and Joyful and Pleasant to Read).
Swimming	Purpose	There are many reasons why people swim, from swimming as a recreational pursuit to swimming as a necessary part of a job or other activity. Swimming may also be used to rehabilitate injuries, especially various cardiovascular and muscle injuries. People may also pursue swimming as a career or field of interest. Some may be gifted and choose to compete professionally and go on to claim fame.
Swimming	Purpose	Recreation Many swimmers swim for recreation, with swimming consistently ranking as one of the physical activities people are most likely to take part in. Recreational swimming can also be used for exercise, relaxation or rehabilitation. The support of the water, and the reduction in impact, makes swimming accessible for people who are unable to undertake activities such as running. Swimming is one of the most relaxing activities, water is known to calm us and can help reduce stress.
Swimming	Purpose	Health Swimming is primarily a cardiovascular/aerobic exercise due to the long exercise time, requiring a constant oxygen supply to the muscles, except for short sprints where the muscles work anaerobically. Furthermore, swimming can help tone and strengthen muscles. Swimming allows sufferers of arthritis to exercise affected joints without worsening their symptoms. However, swimmers with arthritis may wish to avoid swimming breaststroke, as improper technique can exacerbate arthritic knee pain. As with most aerobic exercise, swimming reduces the harmful effects of stress. Swimming is also effective in improving health for people with cardiovascular problems and chronic illnesses. It is proven to positively impact the mental health of pregnant women and mothers. Swimming can even improve mood. Although many forms of physical activity have been shown to improve bone density and health, this is where swimming has its downfalls. Due to the low-impact nature of the sport, studies have demonstrated that bone mass acquisition will be negatively impacted, which could be an issue for adolescent athletes in particular.
Swimming	Purpose	Disabled swimmers Since 2010, the Americans with Disabilities Act has required that swimming pools in the United States be accessible to disabled swimmers.
Swimming	Purpose	Elderly swimmers "Water-based exercise can benefit older adults by improving quality of life and decreasing disability. It also improves or maintains the bone health of post-menopausal women." Swimming is an ideal workout for the elderly, as it is a low-impact sport with very little risk of injury. Exercise in the water works out all muscle groups, helping with conditions such as muscular dystrophy which is common in seniors. It is also a common way to relieve pain from arthritis.
Swimming	Purpose	Sport Swimming as a sport predominantly involves participants competing to be the fastest over a given distance in a certain period of time. Competitors swim different distances in different levels of competition. For example, swimming has been an Olympic sport since 1896, and the current program includes events from 50 m to 1500 m in length, across all four main strokes and medley. During the season competitive swimmers typically train multiple times per day and week to increase endurance, strength, and preserve fitness. Furthermore when the cycle of work is completed swimmers go through a stage called taper where intensity is reduced in preparation for competition season. During taper, focus is on power and water feel.
Swimming	Purpose	The sport is governed internationally by the Fédération Internationale de Natation (FINA), and competition pools for FINA events are 25 or 50 meters in length. In the United States, a pool 25 yards in length is commonly used for competition. Other swimming and water-related sporting disciplines include open water swimming, diving, synchronized swimming, water polo, triathlon, and the modern pentathlon.
Swimming	Purpose	Safety As a popular leisure activity done all over the world, one of the primary risks of swimming is drowning. Drowning may occur from a variety of factors, from swimming fatigue to simply inexperience in the water. From 2005 to 2014, an average of 3,536 fatal unintentional drownings occurred in the United States, approximating 10 deaths a day.To minimize the risk and prevent potential drownings from occurring, lifeguards are often employed to supervise swimming locations such as pools, waterparks, lakes and beaches. Different lifeguards receive different training depending on the sites that they are employed at; i.e. a waterfront lifeguard receives more rigorous training than a poolside lifeguard. Well-known aquatic training services include the National Lifesaving Society and the Canadian Red Cross, which specialize in training lifeguards in North America.
Swimming	Purpose	Occupation Some occupations require workers to swim, such as abalone and pearl diving, and spearfishing.
Swimming	Purpose	Swimming is used to rescue people in the water who are in distress, including exhausted swimmers, non-swimmers who have accidentally entered the water, and others who have come to harm on the water. Lifeguards or volunteer lifesavers are deployed at many pools and beaches worldwide to fulfil this purpose, and they, as well as rescue swimmers, may use specific swimming styles for rescue purposes.
Swimming	Purpose	Swimming is also used in marine biology to observe plants and animals in their natural habitat. Other sciences use swimming; for example, Konrad Lorenz swam with geese as part of his studies of animal behavior.
Swimming	Purpose	Swimming also has military purposes. Military swimming is usually done by special operation forces, such as Navy SEALs and US Army Special Forces. Swimming is used to approach a location, gather intelligence, engage in sabotage or combat, and subsequently depart. This may also include airborne insertion into water or exiting a submarine while it is submerged. Due to regular exposure to large bodies of water, all recruits in the United States Navy, Marine Corps, and Coast Guard are required to complete basic swimming or water survival training.
Swimming	Purpose	Swimming is also a professional sport. Companies sponsor swimmers who have the skills to compete at the international level. Many swimmers compete competitively to represent their home countries in the Olympics. Professional swimmers may also earn a living as entertainers, performing in water ballets. Locomotion Locomotion by swimming over brief distances is frequent when alternatives are precluded. There have been cases of political refugees swimming in the Baltic Sea and of people jumping in the water and swimming ashore from vessels not intended to reach land where they planned to go.
Swimming	Risks	There are many risks associated with voluntary or involuntary human presence in water, which may result in death directly or through drowning asphyxiation. Swimming is both the goal of much voluntary presence and the prime means of regaining land in accidental situations. Most recorded water deaths fall into these categories: Panic occurs when an inexperienced swimmer or a nonswimmer becomes mentally overwhelmed by the circumstances of their immersion, leading to sinking and drowning. Occasionally, panic kills through hyperventilation, even in shallow water.
Swimming	Risks	Exhaustion can make a person unable to sustain efforts to swim or tread water, often leading to death through drowning. An adult with fully developed and extended lungs has generally positive or at least neutral buoyancy, and can float with modest effort when calm and in still water. A small child has negative buoyancy and must make a sustained effort to avoid sinking rapidly.
Swimming	Risks	Hypothermia, in which a person loses critical core temperature, can lead to unconsciousness or heart failure. Dehydration from prolonged exposure to hypertonic salt water—or, less frequently, salt water aspiration syndrome where inhaled salt water creates foam in the lungs that restricts breathing—can cause loss of physical control or kill directly without actual drowning. Hypothermia and dehydration also kill directly, without causing drowning, even when the person wears a life vest.
Swimming	Risks	Blunt trauma in a fast moving flood or river water can kill a swimmer outright, or lead to their drowning.Adverse effects of swimming can include: Exostosis, an abnormal bony overgrowth narrowing the ear canal due to frequent, long-term splashing or filling of cold water into the ear canal, also known as surfer's ear Infection from water-borne bacteria, viruses, or parasites Chlorine inhalation (in swimming pools) Heart attacks while swimming (the primary cause of sudden death among triathlon participants, occurring at the rate of 1 to 2 per 100,000 participations.) Adverse encounters with aquatic life: Stings from sea lice, jellyfish, fish, seashells, and some species of coral Puncture wounds caused by crabs, lobsters, sea urchins, zebra mussels, stingrays, flying fish, sea birds, and debris Hemorrhaging bites from fish, marine mammals, and marine reptiles, occasionally resulting from predation Venomous bites from sea snakes and certain species of octopus Electrocution or mild shock from electric eels and electric raysAround any pool area, safety equipment is often important, and is a zoning requirement for most residential pools in the United States. Supervision by personnel trained in rescue techniques is required at most competitive swimming meets and public pools.
Swimming	Lessons	Traditionally, children were considered not able to swim independently until 4 years of age, although now infant swimming lessons are recommended to prevent drowning.In Sweden, Denmark, Norway, Estonia and Finland, the curriculum for the fifth grade (fourth grade in Estonia) states that all children should learn to swim as well as how to handle emergencies near water. Most commonly, children are expected to be able to swim 200 metres (660 ft)—of which at least 50 metres (160 ft) on their back – after first falling into deep water and getting their head under water. Even though about 95 percent of Swedish school children know how to swim, drowning remains the third most common cause of death among children.In both the Netherlands and Belgium swimming lessons under school time (schoolzwemmen, school swimming) are supported by the government. Most schools provide swimming lessons. There is a long tradition of swimming lessons in the Netherlands and Belgium, the Dutch translation for the breaststroke swimming style is even schoolslag (schoolstroke). In France, swimming is a compulsory part of the curriculum for primary schools. Children usually spend one semester per year learning swimming during CP/CE1/CE2/CM1 (1st, 2nd, 3rd and 4th grade).
Swimming	Lessons	In many places, swimming lessons are provided by local swimming pools, both those run by the local authority and by private leisure companies. Many schools also include swimming lessons into their Physical Education curricula, provided either in the schools' own pool or in the nearest public pool.
Swimming	Lessons	In the UK, the "Top-ups scheme" calls for school children who cannot swim by the age of 11 to receive intensive daily lessons. Children who have not reached Great Britain's National Curriculum standard of swimming 25 meters by the time they leave primary school receive a half-hour lesson every day for two weeks during term-time.In Canada and Mexico there has been a call to include swimming in public school curriculum.In the United States there is the Infant Swimming Resource (ISR) initiative that provides lessons for infant children, to cope with an emergency where they have fallen into the water. They are taught how to roll-back-to-float (hold their breath underwater, to roll onto their back, to float unassisted, rest and breathe until help arrives), while clothed and unclothed. In ISR they teach the children how to roll with their clothes on, as a simulation, if they were to actually fall in walking or crawling by.
Swimming	Lessons	In Switzerland, swimming lessons for babies are popular, to help them getting used to be in another element. At the competition level, unlike in other countries - such as the Commonwealth countries, swimming teams are not related to educational institutions (high-schools and universities), but rather to cities or regions.
Swimming	Clothing and equipment	Swimsuits Standard everyday clothing is usually impractical for swimming and is unsafe under some circumstances. Most cultures today expect swimmers to wear swimsuits. Men's swimsuits commonly resemble shorts, or briefs. Men's casual swimsuits (for example, boardshorts) are rarely skintight, unlike competitive swimwear, like jammers or diveskins. In most cases, boys and men swim with their upper body exposed, except in countries where custom or law prohibits it in a public setting, or for practical reasons such as sun protection. Modern women's swimsuits are generally skintight, covering the pubic region and the breasts (See bikini). Women's swimwear may also cover the midriff as well. Women's swimwear is often a fashion statement, and whether it is modest or not is a subject of debate by many groups, religious and secular. Competitive swimwear is built so that the wearer can swim faster and more efficiently. Modern competitive swimwear is skintight and lightweight. There are many kinds of competitive swimwear for each gender. It is used in aquatic competitions, such as water polo, swim racing, diving, and rowing.
Swimming	Clothing and equipment	Wetsuits provide both thermal insulation and flotation. Many swimmers lack buoyancy in the leg. The wetsuit provides additional volume at a lower density and therefore improves buoyancy and trim while swimming. It provides insulation between the skin and water which reduces heat loss. The wetsuit is the usual choice for those who swim in cold water for long periods of time, as it reduces susceptibility to hypothermia.
Swimming	Clothing and equipment	Some people also choose to wear no clothing while swimming; this is known as skinny dipping. In some European countries public pools have naturist sessions to allow clothes-free swimming and many countries have naturist beaches where one can swim naked. It is legal to swim naked in the sea at all UK beaches. It was common for males to swim naked in a public setting up to the early 20th century. Today, skinny dipping can be a rebellious activity or merely a casual one.
Swimming	Clothing and equipment	Accessories Ear plugs can prevent water from getting in the ears. Noseclips can prevent water from getting in the nose. However, using noseclips in competitive swimming can cause disadvantage, so many competitive swimmer choose not to use one. For this reason, nose clips are primarily used for synchronized swimming and recreational swimming. Goggles protect the eyes from chlorinated water, and improve underwater visibility. Tinted goggles protect the eyes from sunlight that reflects from the bottom of the pool. Swim caps keep the body streamlined and protect the hair from chlorinated water, though they are not entirely watertight. Kickboards are used to keep the upper body afloat while exercising the lower body. Pull buoys are used to keep the lower body afloat while exercising the upper body.
Swimming	Clothing and equipment	Swimfins are used in training to elongate the kick and improve technique and speed. Fins also build upper calf muscles. Fins provide a significantly greater and more efficient conversion of muscle power to thrust than available from the feet, and allow the powerful leg muscles to be used effectively for propulsion through water. The value of fins as an active aid in the teaching, learning and practice of swimming has long been recognised. In the US, as early as 1947, they were used experimentally to build the confidence of reluctant beginners in swimming, while a 1950 YMCA lifesaving and water safety manual reminded swimming instructors how "flippers can be used to great advantage for treading water, surface diving, towing, underwater searching and supporting a tired swimmer". In 1967, research was conducted on fin use in teaching the crawl stroke. During the 1970s, the so-called "flipper-float" method came into vogue in Europe with the aim of helping beginners learn to swim faster and more safely, Hand paddles are used to increase resistance during arm movements, with the goal of improving technique and power.
Swimming	Clothing and equipment	Finger paddles have a similar effect to handle paddles however due to their smaller size create less resistance. They also help with improving a swimmers 'catch' in the water. Snorkels are used to help improve and maintain a good head position in the water. They may also be used by some during physical therapy. Pool noodles are used to keep the user afloat during the time in the water. Safety fencing and equipment is mandatory at public pools and a zoning requirement at most residential pools in the United States. Swimming Parachutes are used in competitive training, adding an element of resistance in the water helping athletes to increase power in the strokes central movements. Inflatable armbands are swimming aids designed to provide buoyancy for the swimmer which helps the wearer to float.
Wisconsin Card Sorting Test	Wisconsin Card Sorting Test	The Wisconsin Card Sorting Test (WCST) is a neuropsychological test of set-shifting, which is the capability to show flexibility when exposed to changes in reinforcement. The WCST was written by David A. Grant and Esta A. Berg. The Professional Manual for the WCST was written by Robert K. Heaton, Gordon J. Chelune, Jack L. Talley, Gary G. Kay, and Glenn Curtiss.
Wisconsin Card Sorting Test	Method	Stimulus cards are shown to the participant and the participant is then instructed to match the cards. They are not given instructions on how to match the cards but are given feedback when the matches they make are right or wrong.
Wisconsin Card Sorting Test	Method	When the test was first released the method of showing the cards was done with an evaluator using paper cards with the evaluator on one side of the desk facing the participant on the other. The test takes approximately 12–20 minutes to carry out using manual scoring which is greatly reduced with the aid of computer testing. The test results produce a number of useful psychometric scores, including numbers, percentages, and percentiles of: categories achieved, trials, errors, and perseverative errors.The WCST has been shown to be reliable and valid in multiple populations including people with autism, people recovering from a stroke, pediatric populations, and psychiatric populations.
Wisconsin Card Sorting Test	Clinical use	Since 1948, the test has been used by neuropsychologists and clinical psychologists in patients with acquired brain injury, neurodegenerative disease, or mental illness such as schizophrenia. It is one of several psychological tests which can be administered to patients to measure frontal lobe dysfunction. When administered, the WCST allows the clinician speculate to the following "frontal" lobe functions: strategic planning, organized searching, utilizing environmental feedback to shift cognitive sets, directing behavior toward achieving a goal, and modulating impulsive responding. The test can be administered to those from 6.5 years to 89 years of age. The WCST, relies upon a number of cognitive functions including attention, working memory, and visual processing. The WCST was originally developed to measure abstract reasoning as such it may be used to help measure an individual's competence in abstract reasoning, and the ability to change problem-solving strategies when needed. In this test, a number of cards are presented to the participants. The figures on the cards differ with respect to color, quantity, and shape.Psychological tests such as the WCST, administered alone, cannot be used to measure the effects of a frontal lobe injury, or the aspects of cognitive function it may affect, such as working memory; a variety of tests must be used. A participant may be good at one task but show dysfunction in executive function overall. Similarly, test results can be made misleading after testing the same individual over a long period of time. The participant may get better at a task, but not because of an improvement in executive cognitive function; they may have simply learned some strategies for doing this particular task that made it no longer a good measurement tool.
Ceph (software)	Ceph (software)	Ceph (pronounced ) is a free and open-source software-defined storage platform that provides object storage, block storage, and file storage built on a common distributed cluster foundation. Ceph provides completely distributed operation without a single point of failure and scalability to the exabyte level, and is freely available. Since version 12 (Luminous), Ceph does not rely on any other, conventional filesystem and directly manages HDDs and SSDs with its own storage backend BlueStore and can expose a POSIX filesystem.
Ceph (software)	Ceph (software)	Ceph replicates data with fault tolerance, using commodity hardware and Ethernet IP and requiring no specific hardware support. Ceph is highly available and ensures strong data durability through techniques including replication, erasure coding, snapshots and clones. By design, the system is both self-healing and self-managing, minimizing administration time and other costs. Large-scale production Ceph deployments include CERN, OVH and DigitalOcean.
Ceph (software)	Design	Ceph employs five distinct kinds of daemons: Cluster monitors (ceph-mon) that keep track of active and failed cluster nodes, cluster configuration, and information about data placement and global cluster state.
Ceph (software)	Design	OSDs (ceph-osd) that manage bulk data storage devices directly via the BlueStore back end, which since the v12.x release replaces the Filestore back end, which was implemented on top of a traditional filesystem) Metadata servers (ceph-mds) that maintain and broker access to inodes and directories inside a CephFS filesystem HTTP gateways (ceph-rgw) that expose the object storage layer as an interface compatible with Amazon S3 or OpenStack Swift APIs Managers (ceph-mgr) that perform cluster monitoring, bookkeeping, and maintenance tasks, and interface to external monitoring systems and management (e.g. balancer, dashboard, Prometheus, Zabbix plugin)All of these are fully distributed, and may be deployed on disjoint, dedicated servers or in a converged topology. Clients with different needs directly interact with appropriate cluster components.Ceph distributes data across multiple storage devices and nodes to achieve higher throughput, in a fashion similar to RAID. Adaptive load balancing is supported whereby frequently accessed services may be replicated over more nodes.As of September 2017, BlueStore is the default and recommended storage back end for production environments, which provides better latency and configurability than the older Filestore back end, and avoiding the shortcomings of filesystem based storage involving additional processing and caching layers. The Filestore back end will be deprecated as of the Reef release in mid 2023. XFS was the recommended underlying filesystem for Filestore OSDs, and Btrfs could be used at one's own risk. ext4 filesystems were not recommended due to limited metadata capacity. The BlueStore back end does still use XFS for a small metadata partition.
Ceph (software)	Design	Object storage S3 Ceph implements distributed object storage via the RADOS GateWay (ceph-rgw), which exposes the underlying storage layer via an interface compatible with Amazon S3 or OpenStack Swift. Ceph RGW deployments scale readily and often utilize large and dense storage media for bulk use cases that include Big Data (datalake), backups & archives, IOT, media, video recording, and deployment images for virtual machines and containers.Ceph's software libraries provide client applications with direct access to the reliable autonomic distributed object store (RADOS) object-based storage system. More frequently used are libraries for Ceph's RADOS Block Device (RBD), RADOS Gateway, and Ceph File System services. In this way, administrators can maintain their storage devices within a unified system, which makes it easier to replicate and protect the data.

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