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|Medical Dictionary - Dictionary of Medicine and Human Biology|
Sectioning of a blood vessel, or the creation of an opening into a vessel prior to its repair. [angio- + G. tome, cutting]
Edward Hartley, U.S. orthodontist, 1855–1930. See A. classification of malocclusion.
angle (θ) (ang′gl) [TA]
The meeting point of two lines or planes; the figure formed by the junction of two lines or planes; the space bounded on two sides by lines or planes that meet. For angles not listed below, see the descriptive term; e.g., axioincisal, distobuccal, labiogingival, linguogingival (2), mesiogingival, proximobuccal, etc. SYN: angulus [TA] . [L. angulus] acromial a. [TA] the prominent a. at the junction of the posterior and lateral borders of the acromion. SYN: angulus acromii [TA] . acute a. any a. less than 90°. adjacent a. an a. with a line in common with another a.. alpha a. 1. the a. between the visual and optic axes as they cross at the nodal point of the eye; 2. the a. between the visual line and the major axis of the corneal ellipse. alveolar a. the a. between the horizontal plane and a line connecting the base of the nasal spine and the middle point of the projection of the alveolus of the maxilla. anorectal a. SYN: anorectal flexure. a. of antetorsion SYN: a. of anteversion. a. of anteversion the a. formed by a line drawn through the center of the long axis of the neck of the femur meeting a line drawn in the transverse axis of the condyles, when the bone is viewed from above, looking straight down from above the head of the femur; used to illustrate the normal degree of anteversion about 12° of the neck of the femur, which may be increased or decreased in some diseases. SYN: a. of antetorsion. a. of aperture the a. formed by lines drawn from the ends of the diameter of a lens to its point of focus. SEE ALSO: angular aperture. apical a. the a. between two plane surfaces of a prism. SYN: refracting a. of a prism. axial a. an a. formed by two surfaces of a body, the line of union of which is parallel with its axis; the axial angles of a tooth are the distobuccal, distolabial, distolingual, mesiobuccal, mesiolabial, and mesiolingual. basilar a. an a. formed by the intersection at the basion of lines coming from the nasal spine and the nasal point. Bennett a. the a. formed by the sagittal plane and the path of the advancing condyle during lateral mandibular movement as viewed in the horizontal plane. beta a. the a. formed by a line connecting the bregma and hormion meeting the radius fixus. biorbital a. an a. formed by the meeting of the axes of the orbits. Broca angles 1. SYN: Broca basilar a.. 2. SYN: Broca facial a.. 3. SYN: occipital a. of parietal bone (1) . Broca basilar a. the a. formed at the basion of lines drawn from the nasion and the alveolar point. SYN: Broca angles (1) . Broca facial a. the a. formed by the intersection at the biauricular axis of lines drawn from the supraorbital point and the alveolar point. SYN: Broca angles (2) . buccal angles angles formed by the buccal surface of a tooth joining the other surfaces. bucco-occlusal a. the line of junction of the buccal and occlusal surfaces of a tooth. cardiodiaphragmatic a. SYN: cardiophrenic a.. cardiohepatic a. the a. formed by the upper border of the liver and the right border of the heart, especially as defined by percussion. SYN: cardiohepatic triangle. cardiophrenic a. the a. between the heart and the diaphragm at either lateral end of the cardiac projection on imaging (usually the chest x-ray film). The right cardiophrenic a. is normally indistinguishable from the cardiohepatic a. radiographically. SYN: cardiodiaphragmatic a., phrenopericardial a.. carrying a. the a. made by the axes of the arm and the forearm, with the elbow in full extension. cavity line a. in dentistry, the a. formed by two walls of a cavity, e.g., a tooth cavity, meeting along a line. cavosurface a. the a. formed by the junction of a cavity wall and the surface of the tooth. cephalic a. one of several angles formed by the intersection of two lines passing through certain points of the face or cranium. cephalomedullary a. the a. made by the junction of the cerebrum and the brainstem. cerebellopontile a. SYN: cerebellopontine a.. cerebellopontine a. the a. formed at the junction of the cerebellum, pons, and medulla; the most common tumor found in this location is the acoustic neuroma. SYN: angulus pontocerebellaris [TA] , cerebellopontile a., pontine a., pontocerebellar recess. costal a. SYN: a. of rib. costophrenic a. the a. between the costal and diaphragmatic parietal pleura as they meet at the costodiaphragmatic line of pleura reflection. Used as a synonym in radiology to identify the costodiaphragmatic recess. SEE ALSO: costodiaphragmatic recess. costovertebral a. the acute a. formed between either twelfth rib and the vertebral column. costoxiphoid a. the a. formed between the right or left costal arch and the long axis of the xiphoid process (usually identical to the midline); it is one half of the infrasternal a.. SEE ALSO: infrasternal a.. SYN: xiphocostal a.. craniofacial a. the a. formed by the basifacial and basicranial axes at the midpoint of the sphenoethmoidal suture. critical a. the a. of incidence at which a ray of light, in passing between two media, changes from refraction to total reflection. SYN: limiting a.. cusp a. 1. the a. made by the slopes of a cusp with the plane which passes through the tip of the cusp and which is perpendicular to a line bisecting the cusp, measured mesiodistally or buccolingually; 2. the a. made by the slopes of a cusp with a perpendicular line bisecting the cusp, measured mesiodistally or buccolingually; 3. one-half of the included a. between the buccal and lingual or mesial and distal cusp inclines. Daubenton a. SYN: occipital a. of parietal bone (2) . a. of declination obsolete term for a. of anteversion. a. of deviation 1. in a prism, the sum of the angles of incidence and emergence minus the apical a. of a prism; 2. in optics, a. of refraction; 3. in strabismus, a. of anomaly. disparity a. the difference in position of images on the retina, still permitting fusion. duodenojejunal a. SYN: duodenojejunal flexure. a. of eccentricity in strabismus, the a. between the line of fixation and the line of normal foveal fixation. a. of emergence the a. formed by a light ray emerging from the second surface of a prism and a line parallel to the incident ray. Cf.:a. of deviation. epigastric a. the a. formed by the xiphoid process with the body of the sternum. ethmoid a. the a. made by the plane of the cribriform plate of the ethmoid bone extended to meet the basicranial axis. facial a. 1. any of several variously named and variously defined anatomic angles that have been used to quantify facial protrusion; 2. in dentistry, the a. formed by the intersection of the orbitomeatal (Frankfort) plane with the nasion-pogonion line (inner lower a.), which establishes the anteroposterior relation of the mandible to the upper face at the orbitomeatal plane. SYN: Frankfort-mandibular incisor a.. a. of femoral torsion the a. formed between the longitudinal axis of the head and neck of the femur proximally and the transverse axis of the femoral condyles distally, when the femur is viewed along the axis of its shaft; normally, this a. is approximately 15° in adults, but is considerably greater in infancy. filtration a. SYN: iridocorneal a.. flip a. in a magnetic resonance imaging pulse sequence, the deviation toward transverse plane of the average axis of the protons induced by radiofrequency signals; low angles are used in rapid or bright blood imaging sequences. Frankfort-mandibular incisor a. SYN: facial a. (2) . frontal a. of parietal bone [TA] the anterior superior a. of the parietal bone. SYN: angulus frontalis ossis parietalis [TA] . a. of Fuchs a crevice between the ciliary and pupillary zones of the iris formed by atrophy of superficial layers of the iris in the pupillary zone. gamma a. the a. formed between a line joining the fixation point to the center of the eye and the optic axis. hypsiloid a. SYN: y-a.. impedance a. a term expressing the ratio of electric resistance to electric capacitance (ohms to microfarads) in the tissues of the body or any other substance. a. of incidence 1. the a. that a ray entering a refracting medium makes with a line drawn perpendicular to the surface of this medium; 2. the a. that a ray striking a reflecting surface makes with a line perpendicular to this surface. SYN: incident a.. incident a. SYN: a. of incidence. incisal guide a. the a. formed with the horizontal plane by drawing a line in the sagittal plane between incisal edges of the maxillary and mandibular central incisors when the teeth are in centric occlusion. a. of inclination the a. formed by the meeting of a line drawn through the shaft of a long bone with one passing through the long axis of its femoral neck; normally refers to the femur and humerus. SYN: neck-shaft a.. inferior a. of scapula [TA] the acute a. formed by junction of the medial and lateral borders of the scapula. SYN: angulus inferior scapulae [TA] . infrasternal a. [TA] the a. between the lower borders of the costal cartilages of the two sides as they approach the sternum. SYN: angulus infrasternalis [TA] , subcostal a.&star, subcostal arch&star, substernal a.. iridocorneal a. [TA] the acute a. between the iris and the cornea at the periphery of the anterior chamber of the eye. SYN: angulus iridocornealis [TA] , a. of iris, angulus iridis, filtration a.. a. of iris SYN: iridocorneal a.. Jacquart facial a. a facial a. with the intersection always at the nasal spine point; additional variation uses the supraorbital point instead of the glabella, and this latter version is also known as ophryospinal facial a. or Topinard facial a.. a. of jaw SYN: a. of mandible. kappa a. the a. between the pupillary axis and the visual axis; it is positive when the pupillary axis is nasal to the visual axis, and negative when the pupillary axis is temporal to the visual axis. lateral a. of eye [TA] the a. formed by the junction of the lateral parts of the upper and lower eyelids. SYN: angulus oculi lateralis [TA] , angulus oculi temporalis, external canthus, lateral canthus. lateral a. of scapula [TA] the blunt, concave head of the scapula forming the glenoid cavity at the junction of the superior and lateral borders of the bone. SYN: angulus lateralis scapulae [TA] . lateral a. of uterus the upper part of the side of the uterus at the point of its junction with the uterine tube. limiting a. SYN: critical a.. line a. in dentistry, the junction of two surfaces of the crown of a tooth, or of a tooth cavity (cavity line a.). Louis a. SYN: sternal a.. Lovibond a. the a. made at the meeting of the proximal nail fold and the nail plate when viewed from the radial aspect; normally, less than 180° but exceeding this in clubbing of the fingers. SYN: Lovibond profile sign. Ludwig a. SYN: sternal a.. lumbosacral a. the a. between the long axis of the lumbar part of the vertebral column and that of the sacrum. a. of mandible [TA] the a. formed by the lower margin of the body and the posterior margin of the ramus of the mandible. SYN: angulus mandibulae [TA] , a. of jaw. mastoid a. of parietal bone [TA] the posteroinferior point of the parietal bone. SYN: angulus mastoideus ossis parietalis [TA] . maxillary a. the a. formed by a line drawn from the ophryon and another from the point of the mandible and meeting at the contact between the upper and lower incisor teeth. medial a. of eye [TA] the a. formed by the union of the upper and lower eyelids medially. SYN: angulus oculi medialis [TA] , angulus oculi nasalis, internal canthus, medial canthus. mesial a. the a. formed by the meeting of the mesial with the labial (or buccal) or lingual surface of a tooth. metafacial a. the a. between the pterygoid processes and the base of the skull. SYN: Serres a.. meter a. the amount of convergence required to view binocularly an object 1 m distant and exerting 1 diopter of accommodation. SYN: unit of ocular convergence. a. of mouth [TA] the lateral limit of the oral fissure. SEE ALSO: labial commissure. SYN: angulus oris [TA] . neck-shaft a. SYN: a. of inclination. occipital a. of parietal bone [TA] 1. the posterior superior a. of the parietal bone; SYN: Broca angles (3) . 2. an a. formed by the junction, at the opisthion, of lines coming from the basion and from the projection in the median plane of the lower border of the orbits. SYN: angulus occipitalis ossis parietalis [TA] , Daubenton a.. SEE ALSO: Daubenton line, Daubenton plane. olfactory a. the a. formed by the plane of the lamina cribrosa and the basicranial axis. ophryospinal a. Jacquart facial a.. parietal a. an a. formed by the meeting of the prolongation of two lines tangential to the most prominent part of the zygomatic arch and to the parietofrontal suture on each side; when the lines remain parallel the a. is zero; when they diverge it is negative. SYN: Quatrefages a.. pelvivertebral a. the a. made by the pelvis as defined by the plane of the superior pelvic aperture with the general axis of the trunk or vertebral column. SEE ALSO: pelvic inclination. phrenopericardial a. SYN: cardiophrenic a.. Pirogoff a. SYN: venous a. (1) . point a. the junction of three surfaces of the crown of a tooth, or of the walls of a cavity. a. of polarization the a. of incidence at which the reflected light is all polarized. pontine a. SYN: cerebellopontine a.. pubic a. SYN: subpubic a.. Q a. the a. formed by lines representing the pull of the quadriceps muscle and the axis of the patellar tendon. Quatrefages a. SYN: parietal a.. Ranke a. the a. formed by the horizontal plane of the head and a line passing from the center of the margin of the alveolar arch of the maxilla, below the nasal spine to the center of the frontonasal suture. [J. Ranke] a. of reflection the a. that a ray reflected from a surface makes with a line drawn perpendicular to this surface; it is equal to the a. of incidence (2). refracting a. of a prism SYN: apical a.. a. of refraction the a. that a ray leaving a refracting medium makes with a line drawn perpendicular to the surface of this medium. a. of retroversion the a. formed by a line drawn through the center of the longitudinal axis of the neck and head of the humerus meeting a line drawn along the transverse axis of the condyles, when the base is viewed from above, looking straight down from above the head of the humerus; the normal a. of retroversion of the humerus is between 20° and 40°. a. of rib [TA] the rather abrupt change in curvature of the body of a rib posteriorly, such that the neck and head of the rib are directed upward. SYN: angulus costae [TA] , costal a.. Rolando a. the a. which the fissure of Rolando (central sulcus) makes with the midplane. Serres a. SYN: metafacial a.. S-N-A a. in cephalometrics, an a. measuring the anteroposterior relationship of the maxillary basal arch on the anterior cranial base; it shows the degree of maxillary prognathism. SEE ALSO: subspinale. [sella-nasion-subspinale (or point A)] S-N-B a. an a. showing the anterior limit of the mandibular basal arch in relation to the anterior cranial base. SEE ALSO: supramentale. [sella-nasion-supramentale (or point B)] sphenoid a., sphenoidal a. 1. a. formed by the intersection at the top of the sella turcica (dorsum sellae), of lines coming from the nasal point and from the tip of the rostrum of the sphenoid; 2. SYN: sphenoidal a. of parietal bone. sphenoidal a. of parietal bone [TA] the anterior inferior a. of the parietal bone. SYN: angulus sphenoidalis ossis parietalis [TA] , sphenoid a. (2) , sphenoidal a., Welcker a.. sternal a. [TA] the a. between the manubrium and the body of the sternum at the manubriosternal junction. Marks the level of the second costal cartilage (rib) for counting ribs or intercostal spaces. Denotes level of aortic arch, bifurcation of trachea, and T4/T5 intervertebral disc. SYN: angulus sterni [TA] , Louis a., Ludwig a., manubriosternal junction. sternoclavicular a. the a. formed by the junction of the clavicle with the sternum. subcostal a. infrasternal a.. subpubic a. [TA] the a. formed between the inferior rami of the pubic bones. In the female, the a. approximates that a. between the widely extended thumb and index finger (90°); in the male, it approximates the a. between the widely abducted index and middle fingers (60°). SEE ALSO: pubic arch. SYN: angulus subpubicus [TA] , pubic a.. substernal a. SYN: infrasternal a.. superior a. of scapula [TA] formerly named the medial a., it lies at the junction of the superior and medial borders of the bone. SYN: angulus superior scapulae [TA] . sylvian a. the a. formed by the sylvian line and a line perpendicular to the horizontal plane tangential to the highest point of the hemisphere. tentorial a. the a. made by the plane of the tentorium and the basicranial axis. Topinard facial a. Jacquart facial a.. a. of torsion the amount of rotation of a long bone along its axis or between two axes, measured in degrees; when this a. is oriented anteriorly, it is referred to as the a. of anteversion and most commonly describes the femur; when this a. is oriented posteriorly, it is the a. of retroversion and most commonly describes the humerus. urethrovesical a. the a. between the female urethra and the posterior vesical wall, normally about 90°; narrowing of this a. in cystocele predisposes to stress incontinence. venous a. 1. the junction of the internal jugular and subclavian veins, toward which converge the external and the anterior jugular and the vertebral veins, the thoracic duct in the left a. and the right lymphatic duct in the right a.; SYN: Pirogoff a.. 2. in neuroradiology, the a. of union of the superior thalamostriate vein (vena terminalis) with the internal cerebral vein, usually closely behind the interventricular foramen (of Monro). Virchow a. an a. formed by the meeting of a line drawn from the middle of the nasofrontal suture to the base of the anterior nasal spine with a line drawn from this last point to the center of the external auditory meatus. SYN: Virchow-Holder a.. Virchow-Holder a. SYN: Virchow a.. visual a. the a. formed at the retina by the meeting of lines drawn from the periphery of the object seen. Vogt a. a craniometric a. formed by the nasobasilar and alveolonasal lines. [K. Vogt] Weisbach a. a craniometric a. formed by the junction, at the alveolar point, of lines passing from the basion and from the middle of the frontonasal suture. Welcker a. SYN: sphenoidal a. of parietal bone. xiphocostal a. SYN: costoxiphoid a.. y-a. in craniometry, the a. at the inion formed by lines drawn from the hormion and the lambda. SYN: hypsiloid a..
Rarely used term for extreme distress or mental anguish. [L. quinsy, anguish] a. animi the sense of being in the act of dying, differing from the fear of death or the desire for death; a symptom that may occur with angina pectoris and occasionally in diseases of the medulla. SYN: a. pectoris (2) . a. pectoris 1. SYN: Gairdner disease. 2. SYN: a. animi.
Anders J., Swedish physicist, 1814–1874. See angstrom, Ångström law, Ångström unit, Ångström scale.
angstrom (Å) (ang′strom)
A unit of wavelength, 10−10 m, roughly the diameter of an atom; equivalent to 0.1 nm. [AJ Ångström]
Old name for a genus of free-living nematodes. See Turbatrix. [Mod. L. dim. of L. anguilla, eel]
1. Formation of an angle; an abnormal angle or bend in an organ. 2. In orthopaedics, a method of describing the alignment of long bones that have been affected by injury or disease; can be described in both anteroposterior and lateral planes. apex anterior a. a. in the lateral plane in which the apex of the angle is directed anteriorly. apex posterior a. a. in the lateral plane in which the apex of the angle is directed posteriorly.
angulus, gen. and pl. anguli (ang′gu-lus, -li) [TA]
SYN: angle. [L.] a. acromii [TA] SYN: acromial angle. a. costae [TA] SYN: angle of rib. a. frontalis ossis parietalis [TA] SYN: frontal angle of parietal bone. a. inferior scapulae [TA] SYN: inferior angle of scapula. a. infrasternalis [TA] SYN: infrasternal angle. a. iridis SYN: iridocorneal angle. a. iridocornealis [TA] SYN: iridocorneal angle. a. lateralis scapulae [TA] SYN: lateral angle of scapula. a. mandibulae [TA] SYN: angle of mandible. a. mastoideus ossis parietalis [TA] SYN: mastoid angle of parietal bone. a. occipitalis ossis parietalis [TA] SYN: occipital angle of parietal bone (2) . a. oculi lateralis [TA] SYN: lateral angle of eye. a. oculi medialis [TA] SYN: medial angle of eye. a. oculi nasalis SYN: medial angle of eye. a. oculi temporalis SYN: lateral angle of eye. a. oris [TA] SYN: angle of mouth. a. pontocerebellaris [TA] SYN: cerebellopontine angle. a. sphenoidalis ossis parietalis [TA] SYN: sphenoidal angle of parietal bone. a. sterni [TA] SYN: sternal angle. a. subpubicus [TA] SYN: subpubic angle. a. superior scapulae [TA] SYN: superior angle of scapula.
Absence of pleasure from the performance of acts that would ordinarily be pleasurable. [G. an- priv. + hedone, pleasure]
Absence of sweat glands or absence of sweating, e.g., due to anticholinergic drugs. SYN: adiaphoresis. [G. an- priv. + hidros, sweat]
1. Relating to, or characterized by, anhidrosis. 2. SYN: antiperspirant (2) . 3. Denoting a reduction or absence of sweat glands, characteristic of congenital ectodermal defect and a. ectodermal dysplasia. SYN: adiaphoretic.
anhistic, anhistous (an-his′tik, -tus)
Without apparent structure. [G. an- priv. + histos, web]
An enzyme that catalyzes the removal of water from a compound; most such enzymes are now known as hydrases, hydro-lyases, or dehydratases. carbonic a. a zinc-containing enzyme that catalyzes the interconversion of CO2 with HCO3− and H+. There are at least seven human isozymes that appear predominantly in red blood cells, secretory tissues, muscle, etc. A deficiency of carbonic a. II can result in osteopetrosis and metabolic acidosis. The inhibition of carbonic a. IV and possibly carbonic a. II by sulfonamides is a current therapy in the treatment of glaucoma. SYN: carbonate dehydratase, carbonate hydro-lyase.
SYN: dehydration (1) .
An oxide that can combine with water to form an acid or that is derived from an acid by the abstraction of water.
Chemical prefix denoting the removal of water. Cf.:pyro- (2) . [G. an- priv., + hydor, water]
A galactose derivative found in a number of polysaccharides ( E.G., agarose).
An intermediate formed in the folic acid-catalyzed glycine-serine interconversion. SYN: N5,N10-methenyltetrahydrofolic acid.
Sugars from which one or more molecules of water, other than water of crystallization, have been eliminated. SYN: dehydrosugars.
Containing no water, especially water of crystallization.
Rarely used term for deficiency of niacinamide which may be associated with pellagra. [G. a- priv. + niacinamide + -osis, condition]
Rarely used term for aniacinamidosis. [G. a- oruv. + niacin + -osis condition]
Shapeless; denoting a formless mass of tissue. SYN: anidous. [see anideus]
A parasitic fetus consisting of a poorly differentiated mass of tissue with slight indications of parts. SEE ALSO: holoacardius amorphus. [G. an- priv. + eidos, shape] embryonic a. a blastoderm without axial organization.
Analgesic agent related chemically and pharmacologically to meperidine hydrochloride; used for relief of moderate to severe pain; also mildly antihistaminic and spasmolytic; addiction liability is equivalent to that of morphine.
An N-acyl aniline; e.g., acetanilide.
anilinction, anilinctus (a-ni-lingk′shun, -lingk′tus)
aniline (an′i-lin, -len)
C6H5(NH2);an oily, colorless or brownish liquid, of aromatic odor and acrid taste, that is the parent substance of many synthetic dyes; derived from benzene by the substitution of the group —NH2 for one of the hydrogen unatoms. A. is highly toxic, may cause industrial poisoning, and may be carcinogenic. SYN: aminobenzene, benzeneamine, phenylamine. [Ar. an-nil, indigo]
aniline blue [C.I. 42755]
A mixture of sulfonated triphenylmethane dyes used widely as a connective tissue stain and counterstain.
Sexual stimulation by licking or kissing the anus; a type of oral-genital sexual activity. SYN: anilinction, anilinctus. [L. anus, + lingo, to lick]
anilinophil, anilinophile (an-i-lin′o-fil, -fil)
Denoting a cell or histologic structure that stains readily with an aniline dye. SYN: anilinophilous. [aniline + G. philos, fond]
Chronic aniline poisoning characterized by gastric and cardiac weakness, vertigo, muscular depression, intermittent pulse, and cyanosis. SYN: anilinism.
1. The soul or spirit. See animus (4) . 2. In jungian psychology, the inner self, in contrast to persona; a female archetype in a man. Cf.:animus (5) . [L. breath, soul]
1. A living, sentient organism that has membranous cell walls, requires oxygen and organic foods, and is capable of voluntary movement, as distinguished from a plant or mineral. 2. One of the lower a. organisms as distinguished from humans. [L.] cold-blooded a. SYN: poikilotherm. control a. in research, an a. submitted to the same conditions as the others used for the experiment, but with the crucial factor (such as the injection of antitoxin, the administration of a drug, etc.) omitted. SEE ALSO: control, control experiment. conventional a. an a. colonized by the burden of resident microorganisms normally associated with its particular species. Houssay a. an a. that has been pancreatectomized and hypophysectomized. Named after the discoverer of the principle that animals are more sensitive to insulin after removal of the pituitary, and that after this operation the intensity of diabetes in depancreatized animals is diminished. normal a. in research, an experimental a. that has neither suffered an attack of a particular disease nor received an injection of a specific microorganism or its toxin. sentinel a. an a. deliberately placed in a particular environment to detect the presence of an infectious agent, such as a virus. warm-blooded a. SYN: homeotherm.
SYN: animal charcoal.
Term used by believers in the preformation theory to designate the supposed miniature body contained in a gamete. See homunculus. [Mod. L. animalculum, dim. of L. animal, a living being]
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