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nucleus

nucleus

nucleus Sentence Examples

  • The nucleus of the city is built on a ridge of rock (Mount Sceberras) which runs like a tongue into the middle of a bay, which it thus divides into two harbours, the Grand Harbour to the east and the Marsamuschetto to the west, which are subdivided again by three other peninsulas into creeks.

  • The nucleus of the township lies on high ground to the east of the Edgware road, which crosses the Welsh Harp reservoir of Regent's Canal, a favourite fishing and skating resort.

  • Rulers of this name are found at Rhodes as late as the 1st century B.C. The Prytaneum was regarded as the religious and political centre of the community and was thus the nucleus of all government, and the official "home" of the whole people.

  • The old district of Assiniboia, the result of the efforts in colonization by the earl of Selkirk in 1811 and succeeding years, was the nucleus of the province.

  • Had his successor been as prudent and able, he might have made a unified Netherlands the nucleus of a mighty middle kingdom, interposing between France and Germany, and a revival of that of the Carolingian Lothaire.

  • (From Nassonov.) I, Nucleus of giant-cell.

  • Of the surplus 1,000,000 was allocated to the improvement of posts, telegraphs and telephones; 1,000,000 to public works (~72o,ooo for harbour improvement and 280,000 for internal navigation); 200,000 to the navy (~I32,ooo for a second dry dock at Taranto and 68,000 for coal purchase); and 200,000 as a nucleus of a fund for the purchase of valuable works of art which are in danger of exportation.

  • Piedmont was shown to possess the qualities necessary to constitute the nucleus of a great nation.

  • The only solid nucleus he finds in it is the fact that there is a great deal of beauty in this world.

  • The latter are vacuolated, and contain each a nucleus and several dark granules.

  • Nucleus of cnidoblast.

  • Another Roman basilica forms the nucleus of the cathedral.

  • Holtzmann (1872) subjected both Colossians and Ephesians to a rigorous examination, and found in Colossians at least a nucleus of Pauline material.

  • von Soden (1885), with well-considered principles of criticism, made a similar examination and found a much larger nucleus, and later still, (1893), in his commentary, reduced the non-Pauline material to a negligible minimum.

  • The cell is essentially an individualized mass of protoplasm containing a differentiated protoplasmic body, called a nucleus.

  • In the Algae such a cell consists essentially of: (1) a mass of protoplasm provided with (2) a nucleus and (3) an assimilating apparatus consisting of a colored protoplasmic body, called a chromatophore, the pigment of which in the pure green forms is chlorophyll, and which may then be called a cliloroplast.

  • The nucleus was definitely recognized in the plant cell by Robert Brown in 1831, but its presence had been previously indicated by various observers and it had been seen by Fontana in some animal cells as early as 1781.

  • In some cases both the nucleus and the chromatophores may be carried along in the rotating stream, but in others, such as T.Titeila, the chloroplasts may remain motionless iii a non-motile layer of the cytoplasm in direct contact with the cell wall.i Desmids, Diatoms and Oscillaria show creeping movements probably due to the secretion of slime by the cells; the swarmspores and plasmodium of the Myxomycetes exhibit amoehoid movements; and the motile spores of Fungi and Algae, the spermatozoids of mosses, ferns, &c., move by means of delicate prolongations, cilia or flagella cf the protoplast.

  • In young cells the chromatophores are small, colorless, highly refractive bodies, principally located around the nucleus.

  • In Spirogyra the pyrenoids are distinctly connected by cytoplasmic strands to the central mass of cytoplasm, which surrounds the nucleus, and according to some observers, they increase exclusively by division, followed by a splitting of the cytoplasmic strands.

  • Starch exists, in the majority of cases, in the form of grains, which are composed of stratified layers arranged around a nucleus or hilum.

  • Albumen crystals are also to be found in the cytoplasm, in leucoplasts and rarely in the nucleus.

  • HaberIandt has shown that in plant cells, when any new formation of membrane is to take place in a given spot, the nucleus is found in its immediate vicinity; and Klebs found that only that portion of the protoplasm of a cell which contains the nucleus is capable of forming a cell-wall; whilst Townsend has further shown that if the non-nucleated mass is connected by strands of protoplasm to the nucleated mass, either of the same cell or of a neighboring cell, it retains the power of forming a cell-membrane.

  • The Structure of the Nucleus.In the living condition the resting nucleus appears to consist of a homogeneous ground substance containing a large number of small chromatin granules and one or more large spherical granulesnucleolithe whole being surrounded by a limiting membrane which separates it from the cytoplasm.

  • The staining reactions of the various parts of the nucleus depend to some extent upon their chemical constitution.

  • B~it the staining reactions of nuclei may vary at different stages of their development; and it i~ probable that there is no method of staining which differentiates with certainty the various morphological constituents of the nucleus.

  • It forms a part of the 1mm or plastin network of the nucleus and may become impregnated with varying quantities of chromatin stored up for use in the formation of the chromosomes and other nuclear activities.

  • Centrosome.The centrosome is a minute homogeneous granule found in the cytoplasm of some cells in the neighborhood of the nucleus.

  • They are more easily seen, when the nucleus is about to undergo mitosis, at the ends of the spindle, where they form the centres towards which the radiating fibres in.

  • Nuclear Division.The formation of new cells is, in the case of tminucleate cells, preceded by or accompanied by the division of the nucleus.

  • In multinucleate cells the division of the nucleus is independent of the division of the cell.

  • 2, L), a nucleolus appears, a nuclear membrane is formed, and daughter nuclei are thus constituted which possess the same structure and staining reactions as the mother nucleus.

  • The spindle arises partly from the cytoplasm, partly from the nucleus, or it may be derived entirely from the nucleusintranuclear spindleas occurs in many of the lower plants (Fungi, &c.).

  • As division proceeds, the filamentous nature of this cytoplasm becomes more prominent and the threads begin either to converge towards the poles of the nucleus, to form a bipolar spindle, or may converge towards, or radiate from, several different points, to form a multipolar spindle.

  • The problem is a very difficult one and cannot be regarded as definitely settled, but it is difficult to understand why all this additional complexity in the division of the nucleus should be necessary if the final result is only a quantitative separation of the chromatin.

  • Cell Division.With the exception of a few plants among the Thallophytes, which consist of a single multinucleate cell, Caulerpa, Vaucheria, &c., the division of the nucleus is followed by the division of the cell either at once, in uninucleate cells, or after a certain number of nuclear divisions, in multinucleate cells.

  • with cytoplasm, nucleus ~.

  • with nucleus, nucleolus -

  • reduction in size is due to A, Two vermiform nuclei in the emthe absence of cytoplasm, bryo sac; one approaching the eggwhich is in some cases so nucleus, the other uniting with the 11 ~ ~h ~h upper polar nucleus.

  • In many of the Fungi the non-motile male cell or nucleus is carried by means of a fertilizing tube actually into the interior of the egg-cell, and is extruded through the apex in close proximity to the egg nucleus.

  • In the Algae, such as Fucus, Volvox, Oedogonium, Bulbochaete, and in the Fungus Monoblepharis, the spermatozoid is a small oval or elongate cell containing nucleus, cytoplasm and sometimes plastids.

  • In the spermatozoids of Chara, Vascular Cryptogams, and in those of Cycas, Zamia and Ginkgo, the cilia arise from a centrosome-like body which is found on one side of the nucleus of the spermatozoid mother-cell.

  • The eggcell or oosphere is a large cell containing a single large nucleus, and in the green plants the rudiments of plastids.

  • In plants with multinucleate cells, such as Albugo, Peronospora and Vaucheria, it is usually a uninucleate cell differentiated by separation of the nuclei from a multinucleate cell, but in Albugo bliti it is multinucleate, and in Sphaero plea it may contain more than one nucleus.

  • In many Gymnosperms the male nucleus penetrates the female nucleus before fusing with it (Blackman, Ikeno).

  • 4, B, C, D), it appears to take no part in the fertilization phenomena, nor in the subsequent division of the nucleus.

  • Whether this is entirely confined to the nucleus is, however, not certain.

  • The strongest direct evidence seems to be that the nuclear substances are the only parts of the cells which are always equivalent in quantity, and that in the higher plants and animals the male organ or spermatozoid is composed almost entirely of the nucleus, and that the male nucleus is carried into the female cell without a particle of cytoplasm.i Since, however, the nucleus of the female cell is always accompanied by a larger or smaller quantity of cytoplasm, and that in a large majority of the power plants and animals the male cell also contains cytoplasm, it cannot yet be definitely stated that the cytoplasm does not play some part in the process.

  • The researches of the last twenty years have shown that the structure of the nucleus and the phenomena of nuclear division in these lower forms conforms in all essential details to those in the higher plants.

  • B, single nucleus due to th~ fusion of the two pre-existing nuclei.

  • The central body probably plays the part of a nucleus and some observers consider that it has the characters of a typical nucleus with mitotic division.

  • The bacteria, in most cases, have no definite nucleus or central body.

  • The chromatin is distributed throughout the cytoplasm in the form of granules which may be regarded as a distributed nucleus corresponding to what Hertwig has designated, in protozoa, chromidia.

  • In the yeast cell the nucleus is represented by a homogenous granule, probably of a nucleolar nature, surrounded and perhaps to some extent impregnated by chromatin and closely connected with a vacuole which often has chromatin at its periphery, and contains one or more volutin granules which appear to consist of nucleic acid in combination with an unknown base.

  • Some observers consider that the yeast nucleus possesses a typical nuclear structure, and exhibits division by mitosis, but the evidence for this is not very satisfactory.

  • Harper, Sexual Reproduction and the Organization of the Nucleus in certain Mildews (pub.

  • Hantzsch (Ber., 1901, 34, p. 3337) has shown that in the action of alcohols on diazonium salts an increase in the molecular weight of the alcohol and an accumulation of negative groups in the aromatic nucleus lead to a diminution in the yield of the ether produced and to the production of a secondary reaction, resulting in the formation of a certain amount of an aromatic hydrocarbon.

  • The so-called "beetle-stones" of the coal-formation of Newhaven, near Leith, which have mostly a coprolite nucleus, have been applied to various ornamental purposes by lapidaries.

  • The red blood-corpuscles are invariably oval disks, with a central nucleus which causes a slight swelling; hence they are oval and biconvex.

  • But this very development of Mosaism implies the existence of an original nucleus or substratum, although the recovery of its precise extent is very difficult.

  • a = nucleus.

  • nucleus.

  • It is certainly derived, through Rossiya, from Slavonic Rus or Ros (Byzantine `Pws or `Pc o-oc), a name first given to the Scandinavians who founded a principality on the Dnieper in the 9th century; and afterwards extended to the collection of Russian states of which this principality formed the nucleus.

  • The principality which was to become the nucleus of the future Russian empire was not Novgorod with its democratic institutions, but its eastern neighbour Moscow, in which the popular assembly played a very insignificant part, and the supreme law was the will of the prince.

  • The nucleus of the invading horde was a small pastoral tribe in Mongolia, the chief of which, known subsequently to Europe as Jenghiz Khan, became a mighty conqueror and created a vast empire stretching from China, across northern and central Asia, to the shores of the Baltic and the valley of the Danube - a heterogeneous state containing many nationalities held together by purely administrative ties and by an enormous military force.

  • The talismanic name Immanuel became the nucleus out of which the later Messianic prophecies of Isaiah grew.

  • There are other nebulae in which a nucleus can be just discerned, others again in which the nucleus is easily seen, and still others where the nucleus is a brilliant star-like point.

  • By 1214 the nucleus of such an institute was formed round Dominic and was known as the "Holy Preaching."

  • As a result of this backward projection of later conceptions, the recovery of the true historical nucleus is difficult.

  • Below it are covered promenades, and from it steps descend to the lower town, the oldest part of which (the so-called Marina), sloping gradually towards the sea, is probably the nucleus of the Roman municipium, while the quarter of Stampace lies to the west, and beyond it again the suburb of Sant' Avendrace.

  • Nucleus of solenocyte.

  • n, So-called nucleus.

  • This forms the nucleus of the adult shell, and, as the animal grows, becomes enclosed by a reflection of the mantle-skirt.

  • Cephalic shield pointed behind; shell internal, chiefly membranous, with calcified nucleus, nautiloid; parapodia forming fins.

  • In Clausilia, according to the observations of C. Gegenbaur, the primitive shell-sac does not flatten out and disappear, but takes the form of a flattened closed sac. Within this closed sac a plate of calcareous matter is developed, and after a time the upper wall of the sac disappears, and the calcareous plate continues to grow as the nucleus of the permanent shell.

  • But it is equally plain that the Ophite nucleus has from time to time received very numerous and often curiously perverted accretions from Babylonian Judaism, Oriental Christianity and Parsism, exhibiting a striking example of religious syncretism.

  • In the eighteenth chapter he records his intention of founding a hall at Oxford, and in connexion with it a library of which his books were to form the nucleus.

  • The two nuclei are successively divided from the egg nucleus in the usual way, but they frequently become absorbed in the peripheral protoplasm instead of being extruded from the egg-cell altogether.

  • Petrunkevich (1901-1903), the second polar nucleus uniting with one daughter-nucleus of the first polar body gives rise to the germ-cells of the parthenogenetically-produced male.

  • There is no reunion of the second polar nucleus with the female pronucleus, but, according to the recent work of L.

  • The segmentation of the fertilized nucleus results in the formation of a number of nuclei which arrange themselves around the periphery of the egg and, the protoplasm surrounding them becoming constricted, a blastoderm or layer of cells, enclosing the central yolk, is formed.

  • In the egg of these insects a small number of nuclei are formed by the division of the nucleus, and each of these nuclei originates by division the cell-layers of a separate embryo.

  • The earliest churches were built with cemeteries for the dead; and thus we find the nucleus of the city of Venice, little isolated groups of dwellings each on its separate islet, scattered, as Cassiodorus 1 says, like sea-birds' nests over the face of the waters.

  • Inside the fortress lies the old Protestant burying-ground, with tombs of Sackville, of John Murray, of Sir Francis Vincent, last ambassador but one from Great Britain to the republic, of Consul Smith, whose collection of books forms the nucleus of the King's library in the British Museum, and of Catherine Tofts, the singer, Smith's first wife.

  • The swift Liburnian vessels began to raid the Lido, compelling the Venetians to arm their own vessels and thus to form the nucleus of their famous fleet, the importance of which was recognized by the Golden Bull of the emperor Basil, which conferred on Venetian merchants privileges far more extensive than any they had hitherto enjoyed, on condition that the Venetian fleet was to be at the disposition of the emperor.

  • After the fall of the Roman empire, it was the nucleus of the kingdom of Carentania, which was founded by Samo, a Frankish adventurer, but soon fell to pieces after his death.

  • From 1847 to 1851 he arranged gifts from France to American libraries aggregating 30,655 volumes, and a gift of 50 volumes by the city of Paris in 1843 (reciprocated in 1849 with more than 1000 volumes contributed by private citizens) was the nucleus of the Boston public library.

  • In Polia the connective tissue enclosed in the external muscular layer is eminently vacuolar - all the intermediate stages between such cells in which the vacuole predominates and the nucleus is peripheral and those in which the granular protoplasm still entirely fills them being moreover present.

  • His personality drew a number of strong men after him, and a society meeting held in a kitchen and then in a warehouse became the nucleus of a circuit, a chapel being built at Tunstall in July 1811, two months after the fusion of the Bourne and Clowes forces.

  • Dumas went no further that thus epitomizing his observations; and the next development was made in 1836 by Auguste Laurent, who, having amplified and discussed the applicability of Dumas' views, promulgated his Nucleus Theory, which assumed the existence of " original nuclei or radicals " (radicaux or noyaux fondamentaux) composed of carbon and hydrogen, and " derived nuclei " (radicaux or noyaux derives) formed from the original nuclei by the substitution of hydrogen or the addition of other elements, and having properties closely related to the primary nuclei.

  • The following diagrams illustrate these statements: - C ` H C OH HC /CH HC CH HC,/CH 'N/ HC CH CH CH From the benzene nucleus we can derive other aromatic nuclei, graphically represented by fusing two or more hexagons along common sides.

  • compounds derived by substituting aliphatic radicals in the benzene nucleus; such a compound is methylbenzene or toluene, C 6 H 5 CH 3.

  • This compound is readily oxidized to benzoic acid, C 6 H 5 000H, the aromatic residue being unattacked; nitric and sulphuric acids produce nitro-toluenes, C6H4 CH3 N02j and toluene sulphonic acids, C 6 H 4 CH 3 SO 3 H; chlorination may result in the formation of derivatives substituted either in the aromatic nucleus or in the side chain; the former substitution occurs most readily, chlor-toluenes, C 6 H 4 CH 3 Cl, being formed, while the latter, which needs an elevation in temperature or other auxiliary, yields benzyl chloride, C 6 H 5 CH 2 C1, and benzal chloride, C 6 11 5 CHC1 2.

  • The introduction of hydroxyl groups into the benzene nucleus gives rise to compounds generically named phenols, which, although resembling the aliphatic alcohols in their origin, differ from these substances in their increased chemical activity and acid nature.

  • These observations may be summarized by saying that the benzene nucleus is more negative in character than the aliphatic residues.

  • Generally if any group be replaced by another group, then the second group enters the nucleus in the position occupied by the displaced group; this means that if we can definitely orientate three di-derivatives of benzene, then any other compound, which can be obtained from or converted into one of our typical derivatives, may be definitely orientated.

  • Soc. 61, p. 367): If the hydrogen compound of the substituent already in the benzene nucleus can be directly oxidized to the' corresponding hydroxyl compound, then meta-derivatives predominate on further substitution, if not, then orthoand paraderivatives.

  • If we accept Kekule's formula for the benzene nucleus, then we may expect the double linkages to be opened up partially, either by oxidation or reduction, with the formation of di-, tetra-, or hexa-hydro derivatives, or entirely, with the production of open chain compounds.

  • Decompositions of this nature were first discovered in the naphthalene series, where it was found that derivatives of indene (and of hydrindene and indone) and also of benzene resulted; Zincke then extended his methods to the disintegration of the oxybenzenes and obtained analogous results, R-pentene and aliphatic derivatives being formed (Rsymbolizing a ringed nucleus).

  • An analogous oscillation prevails in the pyrazol nucleus, for L.

  • cluded that in compounds the benzene nucleus appears to be capable of existence in two tautomeric forms, in the sense that each particular derivative possesses a definite constitution.

  • The benzene nucleus presents a remarkable case, which must be considered in the formulation of any complete theory of valency.

  • [V.], 26, p. 426) in which he discussed various stereo-chemical representations of the benzene nucleus.

  • 149, p. 20) established the symmetry of the naphthalene nucleus, and showed that whichever half of the molecule be oxidized the same phthalic acid results.

  • Formula (4) is symmetrical and based on Kekule's formula: it is in full accord with the syntheses and decompositions of the naphthalene nucleus and the number of isomers found.

  • This is obviously unsymmetrical, consisting of an aliphatic and an aromatic nucleus; Claus explained the formation of the same phthalic acid from the oxidation of either nucleus by supposing that if the aromatic group be oxidized, the aliphatic residue assumes the character of a benzene nucleus.

  • By reduction, the double linkages become saturated, and compounds result which stand in much about the same relation to the original nucleus as hexamethylene does to benzene.

  • Such condensed nuclei are, in many cases, more readily obtained than the parent nucleus.

  • Thus ortho-phenylene diamine yields the following products: N H N ./`N; Xn NZ In some cases oxidation of condensed benzenoid-heterocyclic nuclei results in the rupture of the heterocyclic ring with the formation of a benzene dicarboxylic acid; but if the aromatic nucleus be weakened by the introduction of an amino group, then it is the benzenoid nucleus which is destroyed and a dicarboxylic acid of the heterocyclic ring system obtained.

  • The fifth compound, on the other hand, does not behave as an unsaturated aliphatic compound, but its deportment is that of a nucleus, many substitution derivatives being capable of synthesis.

  • This is comparable with the reduction of the benzene nucleus into hexamethylene, a substance of an aliphatic character.

  • a-pyrone condenses with the benzene ring to form coumarin and isocoumarin; benzo-'y-pyrone constitutes the nucleus of several vegetable colouring matters (chrysin, fisetin, quercetin, &c., which are derivatives of flavone or phenyl benzo-y-pyrone); dibenzo--ypyrone is known as xanthone; related to this substance are fluorane (and fluorescein), fluorone, fluorime, pyronine, &c. The pyridine ring condenses with the benzene ring to form quinoline and isoquinoline; acridine and phenanthridine are dibenzo-pyridines; naphthalene gives rise to a-and /3-naphthoquinolines and the anthrapyridines; anthracene gives anthraquinoline; while two pyridine nuclei connected by an intermediate benzene nucleus give the phenanthrolines.

  • Naphthyridines and naphthinolines result from the condensation of two pryridine and two quinoline nuclei respectively; and quino-quinolines are unsymmetrical naphthyridine nuclei condensed with a benzene nucleus.

  • In the aromatic compounds there is no regularity between the increments due to the introduction of methyl groups into the benzene nucleus or side chains; the normal value of 20 0 -21° is exhibited, however, by pyridine and its derivatives.

  • The city is built upon the lower slope of the Serra do Ouro Preto, a spur of the Espinhago, deeply cut by ravines and divided into a number of irregular hills, up which the narrow, crooked streets are built and upon which groups of low, old-fashioned houses form each a separate nucleus.

  • In 1652 a number of people in Westmorland and north Lancashire who had separated from the common national worship,' came under the influence of Fox, and it was this community (if it can be so called) at Preston Patrick which formed the nucleus of the Quaker church.

  • A reserve fund was created of which the nucleus was the sum already standing to the credit of the " Reserve fund for increasing the rate of interest " (£TI,113,865), plus £T300,000 at least in cash by the issue of sufficient unified bonds to produce that amount and the sum of £T150,000 to be paid by the government to the public debt at the rate of £T15,000 per annum.

  • Railway concessions were given to Germans over the heads of British applicants already in possession of lines from which they were expro- Activity priated, thus affording the nucleus of the Bagdad Turkey.

  • When heated with the halogens, acetophenone is substituted in the aliphatic portion of the nucleus; thus bromine gives phenacyl bromide, C6H6CO.CH2Br.

  • The nucleus of the stronghold is a donjon over 200 ft.

  • The original archduchy, which included Upper Austria, is the nucleus of the Austrian empire, and the oldest possession of the house of Habsburg in its present dominions.

  • 10), for one of the four chief cities, Akkad, Babel, Erech and Calneh, which constituted the nucleus of the kingdom of Nimrod in the land of Shinar or Babylonia.

  • The question whether a corpuscle actually has a material gravitating nucleus is undecided, but there are strong reasons for believing that its mass is entirely due to the electric charge.

  • It was named Sao Paulo, and has been at once the source whence knowledge and civilization have been diffused through Brazil, and the nucleus of a colony of its manliest and hardiest citizens, which sent out successive swarms of hardy adventurers to people the interior.

  • It is probable that the Ottadeni built a fort or camp on the rock on which Edinburgh Castle now stands, which was thus the nucleus around which, in course of time, grew a considerable village.

  • Substitution takes place usually in the nucleus and only rarely in the side chain, and according to the conditions of the experiment and the nature of the compound acted upon, one or more nitro groups enter the molecule.

  • The nucleus of the new army he found in the Czech mercenaries, seasoned veterans who readily transferred their services to the best payer.

  • Towards the second half of the 2nd century B.C. this kingdom seems to have become the nucleus of a great state under Scilurus, whose name appears on coins of Olbia, and who at the same time threatened Chersonese in the Crimea.

  • Perhaps those which were to be sung according to the old Davidic mode formed the nucleus of the collection, and to these were added other poems to be sung according to the more intricate Korahite and Asaphic modes.

  • Certain departmental details were despatched to South Africa to form a working nucleus for military bases, and early in September the cabinet sanctioned the despatch to Natal from India of a mixed force, 5600 strong, while two battalions were ordered to South Africa from the Mediterranean.

  • 1 Thus they are pro vided with a nucleus which is the centre of cell activity; Pathological both of the reproductive and chemical (metabolic) pro- GelIs.

  • The nucleus in its vegetative stage shows a fine network throughout containing in the meshes the so-called nuclear-sap; attached to the network are the chromosomes, in the form of small irregular masses, which have a strong affinity for the " basic dyes."

  • Embedded in the nucleus are one or more nucleoli (plasmosomes) having an affinity for the " acid dyes."

  • The centrosomes which play so important a part in cell division may be found either lying within or at one side of the nucleus in the vegetative condition of the cell.

  • When mitosis is about to take place, they separate from one another and pass to the poles of the nucleus, forming the achromatic spindle.

  • After the division and cleavage of the chromosomes of the original nucleus have taken place they pass from the equator to the poles of the spindle, rearranging themselves close to the separated centrosomes to form daughter nuclei.

  • It consists in an unequal number of chromosomes passing over to each of the daughter nuclei, so that one may become hypochromatic, the other hyperchromatic. When this happens the resulting cleavage of the cytoplasm and nucleus is also unequal.

  • Pigmented cell with resting nucleus.

  • The attraction-sphere and centrosome lie in the cytoplasma in the neighbourhood of the nucleus.

  • Large cell with a single nucleus; nucleoli in a state of degeneration.

  • The nucleolus is elongated, and its longest measurement lies in the direction of the equatorial plane of the nucleus.

  • Division of the nucleolus by elongation, construction, and equilateral division of the nucleus.

  • Division of the nucleolus without any evidence of division of the nucleus.

  • Nucleus with many nucleoli.

  • Direct division of nucleus.

  • Multiple direct division of the nucleus.

  • - Fragmentation of the nucleus.

  • In the earlier accepted notion of direct segmentation, usually known as the schema of Remak, division was described as commencing in the nucleolus, as thereafter spreading to the nucleus, and as ultimately implicating the cell-substance.

  • Oertel thinks that in man we have these two different functions carried on by the one nucleus containing both chromatin orders.

  • The liver cells are seen to contain a large globule of fat which pushes the cell nucleus to one side - giving the signet-ring appearance.

  • (x 300 diam.) colour, situated specially at the poles of the fibre nucleus and extending short distance in the long axis of the fibre.

  • The building of the National Portrait Gallery, adjoining it, dates from 1896, but the nucleus of the collection was formed in 1858.

  • The third natural division of Burma is the old province of Tenasserim, which, constituted in 1826 with Moulmein as its capital, formed the nucleus from which the British supremacy throughout Burma has grown.

  • This formed the nucleus of his future army.

  • C 6 H 5 CCl: CH 2 or a-compounds, and C 6 H 1 CH: CHC1, or co-compounds, whilst in the third the benzene nucleus is substituted.

  • Those substituted in the benzene nucleus are obtained by condensing two molecules of a substituted benzyl and benzal chlorides.

  • The kingship formed the nucleus of new governments as the feudal system passed away.

  • This very likely formed the nucleus of a book which bore the name of that sheik and was much read in the 3rd century from the Flight.

  • Gesch., 3rd ed., p. 160) rejects the earlier foundation; on the other hand, he insists, with the majority of scholars and against Kosters, on the actual return of exiles in 537 to form the nucleus of the post-exilic community (loc. cit., p. 157 n.).

  • At a temperature of about 300-400° C. the alkyl chloride formed in this reaction attacks the benzene nucleus and replaces hydrogen by an alkyl group or groups, forming primary amines homologous with the original amine; thus methylaniline hydrochloride is converted into paraand ortho-toluidine hydrochloride, and trimethyl phenyl ammonium iodide is converted into mesidine hydriodide.

  • This is Harnack's date for the nucleus of Vis.

  • In the case of the pearl oyster this parasite is a cestode larva, but in the less valuable but no less genuine pearl produced by Mytilus, &c., the nucleus is a Trematode-larva (Jameson).

  • They occasionally exhibit striation and originate from large branched cells, the nucleus and unmodified part of which form conspicuous elements.

  • Philaret's zeal for the purity of orthodoxy sometimes led him into excesses: but he encouraged the publication of theological works, formed the nucleus of the subsequently famous Patriarchal Library, and commanded that every archbishop should establish a seminary for the clergy, himself setting the example.

  • The former, which was the original nucleus of all the commercial prosperity of the city, begins on the second Wednesday before Easter; and the latter on the second Wednesday before the 8th of September.

  • The works erected by the Turks for the capture of the fortress of Arad formed the nucleus of the new town.

  • But it was also frequently used to denote (in whole or part) that portion of the old Mithradatic kingdom which lay between the Halys (roughly) and the borders of Colchis, Lesser Armenia, Cappadocia and Galatia - the region properly designated by the title "Cappadocia towards the Pontus," which was always the nucleus of the Pontic kingdom.

  • Thus the three colleges which formed the nucleus of the Imperial University of Tokyo were presided over by a graduate of Michigan College (Professor Toyama), a member of the English bar (Professor HOzumi) and a graduate of Cambridge (Baron Kikuchi).

  • Ehrenberg), a genus of lobose Rhizopoda, characterized by a chitinous plano-convex shell, the circular aperture central on the fiat ventral face, and more than one nucleus and contractile vacuole.

  • Since it does not form an addition product with bromine, reduction must have taken place in one of the nuclei only, and on account of the aromatic character of the compound it must be in that nucleus which does not contain the amino group. This tetrahydro compound yields adipic acid, (CH 2) 4 (CO 2 H) 2, when oxidized by potassium permanganate.

  • The nucleus of the town, the ancient village, lies south of the highroad to Uxbridge, west of the open Ealing Common.

  • Rutherford had announced the nuclear theory of atomic structure which required each atom to consist of a minute positively charged nucleus about which negative electrons were distributed.

  • This number is probably to be identified with the electric charge upon the nucleus of the atom.

  • The voyage of the " Challenger " supplied for the first time the nucleus of a collection of deep-sea deposits sufficient to serve as the basis for comprehensive classification and mapping.

  • The history of Prester John no doubt originally gathered round some nucleus of fact, though what that was is extremely difficult to determine.

  • 1072), succeeded in stripping off the later accretions from the original nucleus of the Historia.

  • The district originally formed part of the parish of Kilmalcolm, the nucleus of the town being the village of Newark attached to the barony of that name.

  • Its dualistic system and its anti-social principles were known only to a few, but its antiecclesiastical organization formed a permanent nucleus round which gathered a great deal of political and ecclesiastical discontent.

  • In 1835 the nucleus of the present district of British Sikkim or Darjeeling was created by a cession of a portion of the hills by the raja of Sikkim to the British as a sanatorium.

  • The 10th division, forming the nucleus of the 4th Army, had begun to land at Takushan on the 19th of May.

  • Five centuries later Lauenburg was incorporated with Hanover, and Wittenberg is the nucleus of modern Saxony, the name being thus transferred from the west to the east of Germany.

  • The latter traced the tubes as far as the nucleus of the ovule.

  • Cytology (q.v.), the intimate structure and behaviour of the cell and its contents - protoplasm, nucleus, &c.

  • No portion of the regular army of the Netherlands is allowed to be sent on colonial service, but individual soldiers are at liberty to enlist, by permission of their commanding officers, in the army of Netherlands India, and they form its nucleus.

  • General Daendels, who was governor from 1808 to 1811, caused the ramparts of the town to be demolished, and began to form the nucleus of a new city at Weltevreden.

  • The other course is to consider matter as formed of ultimate atoms, each the nucleus or core of an intrinsic modification impressed on the surrounding region of the aether; this might conceivably be of the nature of vortical motion of a liquid round a ring-core, thus giving a vortex atom, or of an intrinsic strain of some sort radiating from a core, which would give an electric atom.

  • We recognize an atom only through its physical activities, as manifested in its interactions with other atoms at a distance from it; this field of physical activity would be identical with the surrounding field of aethereal motion or strain that is inseparably associated with the nucleus, and is carried on along with it as it moves.

  • To make room for these we have to remember that the atomic nucleus has remained entirely undefined and beyond our problem; so that what may occur, say when two molecules come into close relations, is outside physical science - not, however, altogether outside, for we know that when the vital nexus in any portion of matter is dissolved, the atoms will remain, in their number, and their atmospheres, and all inorganic relations, as they were before vitality supervened.

  • An important question arises whether, when a material body is moved through the aether, the nucleus of each atom carries some of the surrounding aether along with it; or whether it practically only carries on its strain-form or physical atmosphere, which is transferred from one portion of aether to another after the manner of a shadow, or rather like a loose knot which can slip along a rope without the rope being required to go with it.

  • More recently a way has been pointed out in which a mobile permanent field of electric force could exist% in such a medium so as to travel freely in company with its nucleus or intrinsic charge - the nature of the mobility of the latter, as well as its intimate constitution, remaining unknown.

  • He had as a nucleus but few regular troops, but the energy of the military and civil authorities enabled his force to be augmented by national guards, &c., to 17,600 men.

  • Nucleus >>

  • QUINONES, in organic chemistry, a group of compounds in which two hydrogen atoms of a benzene nucleus are replaced by two oxygen atoms. This replacement may take place either in the ortho or para positions, giving rise to orthoquinones or to paraquinones; metaquinones do not appear to have been isolated.

  • A small nucleus of the proverbs may be Solomon's; but the great majority represent no doubt the generalizations of a long succession of " wise men."

  • Alex., Tert., Hippol.), it is seen that there is a fixed nucleus of writings that is acknowledged, with one exception, over all parts of the Christian world.

  • The transcontinental railway from Limon to Puntarenas was begun in 1871, and forms the nucleus of a system intended ultimately to connect all the fertile parts of the country, and to join the railways of Nicaragua and Panama.

  • Among the institutions connected with the university are the national institution for East Indian languages, ethnology and geography; the fine botanical gardens, founded in 1587; the observatory (1860); the natural history museum, with a very complete anatomical cabinet; the museum of antiquities (Museum van Oudheden), with specially valuable Egyptian and Indian departments; a museum of Dutch antiquities from the earliest times; and three ethnographical museums, of which the nucleus was P. F.

  • 1560), who founded a college for them in 1545 in the town of Billom, besides making over to them his house at Paris, the hotel de Clermont, which became the nucleus of the afterwards famous college of Louis-le-Grand, while a formal legalization was granted to them by the states-general at Poissy in 1561.

  • The old town forms a nucleus of narrow, winding streets surrounded by boulevards, beyond which lie modern quarters with regular thoroughfares and public gardens.

  • Maximilian carried the elaborate etiquette of the court of Vienna to Mexico, but favouring toleration of Protestantism, and the supremacy of the Crown over the Church, he was too liberal for the clericals who had set him up. As a foreigner he was unpopular, and the regiments of Austrians and Belgians which were to serve as the nucleus of his own army were more so.

  • This encounter roused the New England colonies, and in a few days some 16,000 of their townsmen marched in small bands upon Boston to protest against and resist further similar incursions; and in this irregular body we have the nucleus of the colonial forces which carried the war through.

  • In B the nucleus is shown.

  • and was the first to indicate the presence of a nucleus in the cell-body.

  • (X 2000.) II, Clear zone or halo around kineto- a.fl, p. fl, l .s, nucleus.

  • A - D shows the formation of the two nuclear elements (trophonucleus and kinetonucleus) from the definitive nucleus (synkaryon) of the ookinete.

  • The larger nuclear body, which corresponds to the trophonucleus of a Trypanosome, is usually round or oval; the smaller one, representing a kinetonucleus, has the form either of a little rod or of a round grain, and is generally separate from the larger nucleus.

  • In 1904 the formation of a municipally supported gallery of modern art (mainly due to the initiative and generosity of Mr Hugh Lane) was signalized by an exhibition including the pictures intended to constitute the nucleus of the gallery.

  • The old town, close to the river, forms a nucleus round which a newer and more extensive quarter, bordered by boulevards, has grown 'up; the suburbs of St Christophe and Deols lie on the right bank of the Indre.

  • In some Southern states some counties have been subdivided into school districts, each of which elects a school committee, and from this nucleus there may possibly develop something resembling the New England town.

  • The church forms the nucleus, as the centre of the religious life of the community.

  • The church forms the nucleus.

  • (2) Tropine group. Alkaloids characterized by containing the tropine nucleus.

  • The rival school of Basra, on the other hand, has given currency to a story that the original collection made by al-Mufaddal included a much smaller number of poems. The Berlin MS. of al-Marzugi's commentary states that the number was thirty, but a better reading of the passage, found elsewhere,' mentions eighty; and that al-Asma`i and his school added to this nucleus poems which increased the number to a hundred and twenty.

  • Later the sediments lying to the south-east of this " protaxis," or nucleus of the continent, were pushed against its edge and raised into the Appalachian chain of mountains, which, however, extends only a short distance into Canada.

  • Maildulphus, a Scottish or Irish monk, who came into England about 635, built a hermitage near the site of the modern Malmesbury (Maildulphi-urbs, Maldelmesburh, Malmesbiri) and gathered disciples round him, thus forming the nucleus of the later abbey of which Aldhelm his pupil became the first abbot.

  • If we say that he carried on a successful war against the Saxons, was probably betrayed by his wife and a near kinsman, and fell in battle, we have stated all which can be claimed as an historical nucleus for his legend.

  • The flame then appears as a long, narrow, luminous cone, the end being enveloped by a dimly visible portion of flame corresponding to that which surrounds the free flame, while there is also a dark nucleus about the wick.

  • Taken as a whole it is modern in aspect, but its regularity of form is in reality derived from the ancient Roman town of Augusta Taurinorum, which formed its nucleus.

  • Hewitt has also attacked the problem by brominating the oxyazobenzenes, and has shown that when the hydrobromic acid produced in the reaction is allowed to remain in the system, a brombenzene-azo-phenol is formed, whilst if it be removed (by the addition of sodium acetate) bromination takes place in the phenolic nucleus; consequently the presence of the mineral acid gives the azo compound a pseudo-quinonoid character, which it does not possess if the mineral acid be removed from the sphere of the reaction.

  • 1557; Parallaticae commentationis praxeosque nucleus quidam (London, 1573).

  • We have thus the nucleus of that international parliament which idealist peacemakers have dreamt of since the time of Henry IV.'s " grand design."

  • But around this nucleus have collected many tribes of foreign origin.

  • The upper basin of the Trent formed the nucleus of the kingdom of Mercia (q.v.), while farther down the east coast was the kingdom of East Anglia.

  • To get a better share in the European trade at the mouth of the river a body of colonists migrated further down and built Obutöng or Old Town, and shortly afterwards a rival colony established itself at Aqua Akpa or Duke Town, which thus formed the nucleus of the existing town.

  • The only effect of adding solvent will be to separate further from each other the systems composed of solute particle as nucleus and solvent as atmosphere; it will not affect the action of each nucleus on its atmosphere.

  • It is thought to depend upon some connexion, not yet anatomically demonstrated, between the third cranial nerve and its nucleus in the floor of the iter and the substantia nigra.

  • Once afterwards (1898) he held office as minister of home affairs, and in 1900 he stepped down from the leadership of the Jiyu-tõ in order that the latter might form the nucleus of the Seiyu-kai organized by Count Ito.

  • There was thus very strong circumstantial evidence in favour of fertilization, although the male nucleus was not traced.

  • nucleus in skin.

  • The Brera Gallery, the nucleus of which was formed in 1806, possesses Raphael's famous "Sposalizio," and many pictures and frescoes by Luini, Guadenzio Ferrari and Bramantino; the collection of the works of Carlo Crivelli (fl.

  • The nucleus of a cosmopolitan society thus formed has expanded into a powerful community enjoying privileges and immunities unknown to natives not receiving its protection.

  • Although many fungi have been regarded as devoid of nuclei, and all have not as yet been proved to contain them, the numerous investigations of recent years have revealed them in the cells of all forms thoroughly examined, and we are justified in concluding that the nucleus is as essential to the cell of a fungus as to that of other organisms. The hyphae of many contain numerous, even hundreds of nuclei (Phycomycetes); those of others have several (Aspergillus) in each segment, or only two (Exoascus) or one (Erysiphe) in each cell.

  • Even the isolated cells of the yeast plant have each one nucleus.

  • In young asci a similar fusion of two nuclei occurs, and also in basidia, in each case the nucleus of the ascus or of the basidium resulting from the fusion subsequently giving rise by division to the nuclei of the ascospores and basidiospores respectively.

  • The contents of the antheridium are not set free, but that organ penetrates the oogonium by means of a narrow outgrowth, the fertilizing tube, and a male nucleus then passes over into the single oosphere, which at first multinucleate becomes uninucleate before fertilization.

  • In the development of the ascus we find two nuclei at the base which fuse together to form the single nucleus of the young ascus.

  • The single nucleus divides by three successive divisions to form eight nuclei lying free in the protoplasm of the ascus.

  • Then by a special method, described first by Harper, a mass of protoplasm is cut out round each nucleus; thus eight uninucleate ascospores are formed by free-cell formation.

  • 6, The multicellular ascogonium 3, Passage of the antheridial derived by division from the nucleus towards that of the oogonium; the terminal cell oogonium.

  • Under other conditions, of which the temperature is an important one, the nucleus in the yeast-cell divides, and each daughter-nucleus again, and four spores are formed in the mother cell, a process obviously comparable to the typical development of ascospores in an ascus.

  • The study of the nucleus of yeast-cells is rendered difficult by the presence of other deeply staining granules termed by Guillermond naetachromatic granules.

  • In the process of budding the nucleus divides apparently by a process of direct division.

  • In the formation of spores the nucleus of the cell divides, the protoplasm collects round the nuclei to form the spores by free-cell formation; the protoplasm (epiplasm) not used in this process becomes disorganized.

  • De Bary brought forward very strong evidence for the origin of the ascocarp in Sphaerotheca and Erysiphe by a sexual process, but Harper in 1895 was the first to prove conclusively, by the observation of the nuclear fusion, that there was a definite fertilization in Sphaerotheca Humuli by the fusion of a male (antheridial) nucleus with a female, ascogonial (oogonial) nucleus.

  • C, A basidium before the four nucleiderived from the secondary nucleus of the basidium have passed into the four basidiospores.

  • D, Passage of a nucleus through the sterigma into the basidiospore.

  • There we find an association of nuclei either by the fusion of two similar cells as described by Christmann or by the migration of the nucleus of a vegetative cell into a special cell of the aecidium.

  • uredospores in the hemi and a, Fertile cells; at a 2 the brachy forms, and before the passage of a nucleus from formation of teleutospores in the adjoining cell is seen.

  • Whether B, Formation of the first sporethe association of nuclei in the mother-cell (sm), from the ordinary mycelium takes place basal cell (a) of one of the by the migration of a nucleus rows of spores.

  • (1896); "Sexual Reproduction and the Organization of the Nucleus in certain Mildews," Publ.

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