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1.
Summary Eleven restriction site polymorphisms in the -globin gene cluster were determined in 48 Chinese with homozygous -thalassemia and their parents. Seven haplotypes were identified as associated with the thal chromosome and 25 with the A chromosome. The distribution of the various thal haplotypes in different regions of South China was mapped and discussed in relation to prenatal diagnosis and migration of the Chinese people. 相似文献
2.
Carl C. Childers Raul Villanueva Hugo Aguilar Ryan Chewning John P. Michaud 《Experimental & applied acarology》2001,25(6):461-474
Residual toxicities of registered and selected experimental pesticides used on citrus against Agistemus industani Gonzalez (Acari: Stigmaeidae) were compared. Pesticides considered highly toxic to A. industani were: abamectin 0.15 EC at 731ml/ha+FC 435-66 petroleum oil at 46.8l/ha, pyridaben 75WP at 469g/ha, ethion 4EC at 7.01l/ha+FC 435-66 petroleum oil at 46.8l/ha, propargite 6.55 EC at 3.51l/ha, chlorfenapyr 2SC at 1.46l/ha applied alone or in combination with FC 435-66 petroleum oil at 46.8l/ha, sulphur 80DF at 16.81kg/ha, dicofol 4EC at 7.01l/ha, fenbutatin oxide 50WP at 2.24kg/ha, benomyl 50WP at 2.24kg/ha, benomyl 50WP at 1.68kg/ha+ferbam 76 GF at 5.60kg/ha, ferbam 76GF at 11.21kg/ha, neem oil 90EC at 46.8l/ha, and copper hydroxide DF (40% metallic copper) at 4.48kg metallic copper/ha+FC 435-66 petroleum oil at 46.8l/ha. Pesticides that were moderately to slightly toxic included: copper sulphate 98% at 4.48kg metallic copper/ha+FC 435-66 petroleum oil at 46.8l/ha, fenbuconazole 2F at 280ml/ha+FC 435-66 petroleum oil at 46.8l/ha, FC 435-66 petroleum oil applied alone at 46.8l/ha or 23.4l/ha, and diflubenzuron 25WP at 1.40kg/ha. Pesticides that were non-toxic included: fenbuconazole 2F at 585ml/ha, malathion 57EC at 5.85l/ha, FC 435-66 petroleum oil at 46.8l/ha, carbaryl 80S at 3.36kg/ha, chlorpyrifos 4EC at 4.68l/ha, and formetanate 92SP at 1.12kg/ha. Understanding the toxic effects of field weathered pesticides against key predacious mite species is important for effective IPM. The results of this study provide a comparison of direct and indirect toxic effects of various pesticides to A. industani under field conditions. 相似文献
3.
Deposition of amyloid peptide in human brain in the form of senile plaques is a neuropathological hallmark of Alzheimers disease (AD). Levels of a phospholipid breakdown product, glycerophosphocholine (GPC), also increase in AD brain. The effect of GPC on amyloid (1–40) peptide (A) aggregation in PBS buffer was investigated by circular dichroism and fluoresence spectroscopy; interactions of A and GPC with the intact erythrocyte membrane was examined by fluoresence spectroscopy. Fluorescamine labeled A studies indicate GPC enhances A aggregation. CD spectroscopy reveals that A in the presence of GPC adopts 14% more -sheet structure than does A alone. Fluorescamine anisotropy measurements show that GPC and A interact in the phospholipid head-group region of the erythrocyte membrane. In summary, both soluble A and GPC insert into the phospholipid head-group region of the membrane where they interact leading to -sheet formation in soluble A which enhances A aggregation. 相似文献
4.
Dr P. S. J. Overhage 《Acta biotheoretica》1957,12(2):81-114
Zusammenfassung Die Arbeit stellt die Frage nach den Kriterien des fossil belegten Biologischen Aufstiegs der Organismenwelt, d.h. derjenigen Vervollkommnung, die sich nicht innerhalb des Rahmens eines gegebenen Bauplans hält, wie die Anpassungsvervollkommnung, sondern über verschiedenrangige Baupläne hinweg zu höheren Typen führt, z.B. von den Fischen über die Amphibien und Reptilien zu den Säugern bzw. Vögeln. Ausführlich werden zwei Gruppen von Kriterien besprochen, ihr Inhalt dargelegt und ihre Eindeutigkeit zur Charakterisierung des Biologischen Aufstiegs untersucht. Die erste Gruppe umfasst die Kriterien der zunehmenden Differenzierung und harmonischeren Integration. Diese legen die morphologisch-physiologische Differenzierung oder genauer die Ganzheit der Organismen zugrunde, d.h. ihre Vielheit in der Einheit. Die zweite Kriteriengruppe, nämlich zunehmende Umweltunabhängigkeit und zunehmende individuelle Autonomie, geht von den Beziehungen des Organismus zur Umwelt und zu andern Lebensformen aus und betont die Subsistenz der Individuen, d.h. ihr grösseres oder geringeres Losgelöstsein oder ihre Selbständigkeit. Da nun Ganzheit und Subsistenz die entscheidenden Elemente einer biologischen Definition des Individuums sind, lässt sich sagen, dass der Biologische Aufstieg eines Organismus um so höher ist, je stärker seine Ganzheit und Subsistenz und damit sein Individuumsein ist.Eindeutigkeit kommt allen genannten Kriterien nicht zu. Die Gründe für ihre Unschärfe sind verschiedener Art. Zunächst gibt es noch keine eindeutige und vollständige Definition des biologischen Individuums, so dass sich nicht eindeutig umreissen lässt, was einem Organismus eine stärkere oder weniger starke Individualität verleiht. Dann sind die Linien, über die sich Vervollkommnungen vollziehen und von denen die eine innerhalb des Bauplans bleibt (Anpassungsvervollkommnung), die andere aber über ihn hinausführt (Biologischer Aufstieg) so innig und in so eigenartiger Weise miteinander verflochten, dass sie sich nicht sauber scheiden und in ihren charakteristischen Merkmalen genau beschreiben lassen. Jeder Vertreter eines Bauplans, ganz gleich von welcher Ranghöhe, ist nämlich notwendig in eine Umwelt eingepasst und irgendwie spezialisiert. Es gibt keine Typen mit reinen Bauplanmerkmalen, die nach keiner Richtung hin eine Anpassungsvervollkommnung, sondern nur Merkmale des Biologischen Aufstiegs aufweisen. Schliesslich kennen wir fossil nur die Entfaltung oder Ausgestaltung der Grossbaupläne des Tierreichs, nämlich des Wirbeltierstammes und der verschiedenen Gruppen der Wirbellosen, nicht aber das Interessanteste und Wichtigste, nämlich ihren Biologischen Aufstieg zu der organisatorischen Höhe, mit der sie sich im Silur bzw. im Kabrium bereits vorstellen. Das erst würde einen tieferen Einblick in das Wesen des Biologischen Aufstiegs vermitteln.
Summary This article deals with the question of the criteria for the biological ascent (Biologischer Aufstieg) of the organic world, resting on fossil evidence. That is, of that improvement which is not only restricted to the framework of a given general structure (Bauplan) as is the improvement of adaptation, but which also leads beyond general structures (Baupläne) of differentiated levels to a higher type,e.g. from the fishes through the amphibians and reptiles to the mammals or birds. Two groups of criteria are discussed at length, their content exposed and their univocity for the characterisation of this biological ascent is examined. The first group includes the criteria of increasing differentiation and more harmonious integration. The basis for these is the morphological-physiological differentiation, or more exactly, the totality of the organisms,i.e., their variety-in-unity. The second group of criteria, increasing independence of environment and increasing individual autonomy, is derived from the relationships of the organism to its environment and to other living forms, and stresses the subsistence of individuals,i.e., their greater or lesser degree of independence or self-sufficiency. Now since totality and subsistence are the decisive elements in a biological definition of the individual, it may be said that the biological ascent of an organism is higher, the more perfect its totality and subsistence and therefore its individuality is.The criteria mentioned are not univocal. The reasons for this lack of clarity are varied. First of all, there is no univocal and complete definition of the biological individual, so that it cannot be exactly stated just what gives an organism a more or less perfect individuality. Then the lines, along which improvements are made, and according to which the one remains within the general structure (improvement of adaptation) and the other goes beyond the general structure (biological ascent), are so intimately and singularly bound together, that they cannot be cleanly distinguished, and their characteristic notes exactly described. For each representative of a general structure, regardless of its level, is necessarily fitted into an environment and somehow or other specialised. There are no types with only notes of the general structure which show in no direction an improvment of adaption, but only the signs of biological ascent. Finally, we only have fossil evidence for the development or deployment of the great general structures (Grossbaupläne) of the animal world, namely that of the vertebrates and of the different groups of invertebrates, not for the most interesting and most important, that is, their biological ascent to the level of organisation with which they are found in the Silurian or Cambrian periods. Only that would give us a deeper insight into the essence of biological ascent.
Résumé Ce travail pose la question des critères de la progression biologique (Biologischer Aufstieg), d'après les documents fossiles, dans le monde des organismes, c'est-à-dire de ce perfectionnement qui ne s'arrête pas à l'intérieur du cadre d'un phylum (Bauplan) donné, comme le perfectionnement de l'adaptation, mais qui conduit, au-de-là de phylums (Baupläne) de rang différent, à des types supérieurs, par exemple, des Poissons pas les Amphibies et les Reptiles jusqu'aux Mammifères ou aux Oiseaux. Deux groupes de critères y sont recensés en détail, leur contenu est exposé, et on les examine pour voir s'ils caractérisent sans ambiguïté la progression biologique. Le premier groupe comprend les critères de différenciation croissante et d'intégration harmonique. Ils sont fondés sur la différenciation morphophysiologique ou plus exactement sur la totalité des organismes, c'est-à-dire leur multiplicité dans l'unité. Le second groupe de critères, à savoir indépendance croissante du milieu et autonomie individuelle croissante, part des relations de l'organisme au milieu et aux autres formes vivantes et souligne la subsistence des individus, c'est-à-dire leur plus ou moins grande indépendence ou leur stabilité interne. Comme totalité et subsistence sont les éléments décisifs d'une définition biologique de l'individu, on peut dire que la progression biologique d'un organisme est d'autant plus élevée que sa totalité et subsistence et par là son être individuel sont plus accusés.Tous les critères mentionnés ne sont pas uniformes. Les motifs de leur imprécision sont divers. Tout d'abord, il n'y a pas encore de définition unique et complète de l'individu biologique, de sorte qu'on ne peut circonscrire d'une manière univoque ce qui confère à un organisme une individualité plus forte ou moins forte. Ensuite les lignées au-delà desquelles s'accomplissent des perfectionnements, et dont l'une reste intérieur au phylum (perfectionnement de l'adaptation), tandis que l'autre le transcende (progression biologique), sont entrelacées si intimement et d'une façon si particulière qu'elles ne se laissent pas séparer franchement et décrire rigoureusement selon leurs signes distinctifs. Tout représentant d'un phylum, peu importe son palier, est en effet nécessairement inséré dans un milieu et en quelque façon spécialisé. Il n'existe pas des types à caractères phylétiques purs, qui ne montrent dans aucune direction un perfectionnement de l'adaptation, mais seulement des marques caractéristiques de la progression biologique. Enfin nous ne connaissons pas les restes fossiles que le développement ou la formation des grands phylums (Grossbaupläne) du règne animal, à savoir du rameau des Vertébrés et des divers groupes des Invertébrés, mais non pas le plus intéressant et le plus important, leur progression biologique jusqu'au degré d'organisation qu'ils présentent déjà à l'époque du Silurien ou plutôt du Cambrien. C'est cela seulement qui permettrait une vue plus profonde sur la nature de la progression biologique.相似文献
5.
David H. Foster 《Biological cybernetics》1972,11(4):223-229
An experiment is described which shows in operation the program set out in Foster (1972a) for the investigation of the invariance transformations of visual recognition. The concern in the present study is with the Lie group of rotations SO(2), and a certain centrally located foveal Landolt ring. By presenting to the visual system this Landolt ring and a rotated image in rapid succession, one attempted to induce a specified rotation-type phi-motion. Two subjects were employed. Both reported the existence of the required type of phi-motion for rotations 0 of the Landolt ring about the visual axis with -2/72/7. By appealing to the basic Proposition 2 of Foster (1972 a), the conclusion is reached that the visual system appears capable of effecting upon a certain centrally located foveal annulus the local 1-parameter group of rotations about the visual axis 0, [–2/7,2/7]. 相似文献
6.
Kurt Kuhnen 《Journal of Ornithology》1985,126(1):1-13
Zusammenfassung Uferschwalben kehren aus den afrikanischen Winterquartieren in Trupps beiderlei Geschlechts zurück. Erste Beringungsergebnisse belegen, daß zunächst mehrjährige, vermutlich untereinander bekannte Vögel eintreffen, die den Brutplatz aus vergangenen Brutperioden her kennen. Die Masse der später ankommenden Vögel dürfte weitgehend aus einjährigen oder ortsfremden Uferschwalben bestehen, die sich größtenteils erst während der Paarbildung persönlich kennenlernen. Der anfängliche Schwarmzusammenhalt der nacheinander eintreffenden Trupps führt zur Bildung von Subkolonien, die für Brutplätze ab einer bestimmten Größenordnung typisch sind. Uferschwalben- gründen nacheinander mehrere Reviere, d. h. sie besetzen Steilwandbereiche, in denen sie ausschließlich mit den Füßen eine Röhre oder Mulde graben, singen und Bogenflüge starten. Bis auf singende oder bekannte werden Artgenossen im Revier geduldet. Uferschwalben- suchen besetzte Reviere auf. Ohne Röhrenbindung verhalten sie sich still und unauffällig, ihre Grabungsaktivitäten sind von untergeordneter Bedeutung. Die Bindung an ein bestimmtes Revier entwickelt sich individuell verschieden und entscheidet über den Abschluß des Röhrenbaues (Herstellung der Nistkammer). Reviere ohne dauerhafte -Bindung werden von den aufgegeben. Aktivitäten, die auf wachsende Revierbindung eines hindeuten, sind: häufige oder/und länger dauernde Aufenthalte des in einem besetzten Revier und sporadisches Mitgraben; aggressives Verhalten gegenüber Artgenossen (i. d. R. fremde ), die im Revier landen wollen; gemeinschaftlicher, leiser Gesang von und im Röhrenbereich. Aktivitäten, die für eine vollzogene Paarbildung sprechen, sind: Fertigstellen der Röhre durch Grabung der Nestkammer; längere gemeinsame Aufenthalte innerhalb und außerhalb der Röhre; Voranfliegen des beim Röhrenanflug; Übernachten von und in der Röhre; Nestbau; ausdauernde Verfolgungsflüge während der Kopulationsphase. Die Paarbildung ist demnach ein individueller Prozeß, bei dem die Aktivitäten der im Revier als Werbung, die der als Revierwahl interpretiert werden.
On pair-formation in the Sand Martin,Riparia riparia
Summary European Sand Martins arrive at their breeding sites in flocks of usually unmated and . Ringing results of a large population in NW-Germany and own observations indicate that the first flocks about a dozen individuals with an approximately balanced sex ratio appear at traditional breeding places and consist of older, experienced resident birds (presumably acquainted with one another). The birds arriving over the next several weeks are mainly first-year or non-resident individuals. The flocks arrive separately in areas with suitable sandcliffs, synchronize the pair-formation activities and avoid disturbances among paired and unpaired birds. This behaviour causes the formation of subcolonies, which are typical for all densely occupied breeding places. Each settles on a fixed area on the sandcliff (territory) in order to excavate a burrow, to sing the territory-song (fig. 2 b) and to perfor the territory-circle-flight (fig. 2 c, 4 a). Silent birds (normally ) are welcomed or tolerated by the resident . The sexes are monomorphic and therefore courtship displays of the are non-aggressive until establishment of pair-bonds. Only intruding singing or individually known neighbouring are driven away, usually at early stages of territory occupation. Unmated are normally shy and very sensitive to protracted disturbances. visit several occupied territories of the colony (fig. 1–3) in order to choose a burrow. leave territories which do not attract a . They settle new territories on the sandcliff, causing a surplus of burrows compared to breeding pairs in the colony. Activities which indicate the development of pair-bonds are: regular visits of a to a particular occupied territory with sporadic excavations by the ; aggressive activities of the towards other visitors usually , but sometimes at first even against the resident (i. e.: vocal threats, bill-gaping, pecking or pushing with the bill or vigorous face-to-face fights, fig. 3 b, 3 c). and sing the soft mating song at or in the burrow (fig. 1 c). Activities which indicate completed pair-bonds are: completion of the burrow by digging the nestchamber, predominantly done by the ; both birds staying together over long periods, both inside and outside the burrow; invitation-flight by the (fig. 4 b); and spending the night together in the burrow; beginning of nest-building, first only by the , then by both birds and finally only by the , accompanied by the (guarding-flight;, fig. 4c); mate-pursuit flights (sexual chases) during copulation phase, in which the singing pursues the silent , often accompanied by other (cp. fig. 4 d). Pair-formation in the Sand Martin occurs on individual territories and not, according toHickling (1959), within the flock.相似文献
7.
We have isolated an unusual T cell receptor chain cDNA clone (7.1) from a library made from RNA derived from adult thymus of C57BL/Ka mice. This cDNA clone corresponds to the appropriately processed C1 constant region exons preceded by 1.5 kb of J-C1 intron. The 7.1 coding region is extremely homologous to the C1 gene of BALB/c mice, differing at the protein level by a single deletion (alanine 139) and a single substitution. This latter change eliminates the sole N-linked sugar attachment site, providing a basis for strain-specific glycosylation patterns. The J-C1 intronic region contains two DNA segments (termed J1 and J2) that are highly reminiscent of joining (J) segments; both have potentially functional recombination and donor splice sequences flanking an open reading frame. Northern analysis suggests that 7.1 may be derived from a large, variable region-containing precursor. 相似文献
8.
The rate of accumulation of conjugated dienes of polyunsaturated fatty acids was measured during free-radical oxidation of linoleic acid (18:2n-6, LA), -linolenic acid (18:3n-3, -LNA), and -linolenic acid (18:3n-6, -LNA) initiated by 2,2"-azo-bis-(2-amidinopropane) hydrochloride in aqueous micellar solutions of sodium dodecyl sulfate and sodium cholate. It was shown that, unlike homogeneous solutions, the oxidative stability of PUFAs in aqueous dispersions increased with an increase in the extent of unsaturation. The rate of LA oxidation was more than tenfold greater than that of - and -LNA. The antioxidant activity of -carotene, in contrast to homogeneous solutions, in both micellar systems studied depended on the degree of PUFA unsaturation. We found that 5 M -carotene effectively inhibited the LA oxidation (almost by 90%), whereas the oxidation of -LNA and -LNA was not inhibited by -carotene even at much greater concentration (30 M). The paradoxical discrepancy between the extent of unsaturation and the PUFA oxidation rate, as well as a decrease in the efficiency of -carotene-dependent inhibition of oxidation of more polyunsaturated fatty acids in reactions conducted in aqueous dispersions is consistent with the model according to which the peroxyl radicals of LA and fatty acids with the doublebond number greater than two exhibit different polarity. 相似文献
9.
Annerose und Fritz Anders 《Molecular & general genetics : MGG》1963,94(1):1-18
Zusammenfassung Beim wildenPlatypoecilus maculatus aus Mexiko, der im männlichen Geschlecht heterogamet ist (Gordon 1946), ist neben dem gonosomalen noch ein autosomales System von Geschlechtsrealisatoren am Werke (vgl.Öktay 1959). Es vermag in extremen Konstellationen, die zufalls- oder selektionsbedingt sein können, denXY-Mechanismus epistatisch zu überlagern, so da\XY-Individuen zu determiniert werden können.XY- sind voll vital und fertil und ergeben in Paarungen mitXY- nebenXX- undXY- voll vitale und fertileXY-.Auf Grund der vorliegenden Kreuzungsergebnisse und der Befunde anderer Autoren wird angenommen, daß der normalerweise rein gonosomale Geschlechtsbestimmungsmodus vonPlatypoecilus maculatus aus dem primitiveren autosomal polyfaktoriellen, der unter anderem bei einem nahen Verwandten dieser Art,Xiphophorus helleri, vorkommt (Kosswig 1931 ff.), hervorgegangen ist.Mit 1 Textabbildung 相似文献
10.
C. M. Tu 《Archives of microbiology》1976,108(3):259-263
Of 147 microorganisms isolated from a loamy sand, 71 showed good growth with lindane (-1,2,3,4,5,6-hexachlorocyclohexane) and produced chloride in an aqueous medium. Thirteen soil microorganisms were selected to study the utilization of lindane. Lindane was metabolized by the microbes to -2,3,4,5,6-pentachloro-1-cyclohexene (-PCCH), -3,4,5,6-tetrachloro-1-cyclohexene (-TCCH), -3,4,5,6-tetrachloro-1-cyclohexene (-TCCH), -3,4,5,6-tetrachloro-1-cyclohexene (-TCCH), and pentachlorobenzene (PCB). Cells of Pseudomonas sp. No. 62 grown on lindane simultaneously adapted to -PCCH, -TCCH, -TCCH, -TCCH, PCB, 1,2,3,4-tetrachlorobenzene (1,2,3,4-TCB) and 1,2,4,5-tetrachlorobenzene (1,2,4,5-TCB). The bacteria degraded each of these chemicals at least partially as indicated by an increased rate of oxygen consumption.Abbreviations Lindane
-1,2,3,4,5,6-hexachlorocyclohexane
- -PCCH
-2,3,4,5,6-pentachloro-1-cyclohexene
- -TCCH
-3,4,5,6-tetrachloro-1-cyclohexene
- -TCCH
-3,4,5,6-tetrachloro-1-cyclohexene
- -TCCH
-3,4,5,6-tetrachloro-1-cyclohexene
- PCB
pentachlorobenzene
- 1,2,3,4-TCB
1,2,3,4-tetrachlorobenzene
- 1,2,3,5-TCB
1,2,3,5-tetrachlorobenzene
- 1,2,4,5-TCB
1,2,4,5-tetrachlorobenzene
- 1,2,3-tCB
1,2,3-trichlorobenzene
- 1,2,4-tCB
1,2,4-trichlorobenzene
- 1,3,5-tCB
1,3,5-trichlorobenzene
- 1,2-DCB
1,2-dichlorobenzene
- 1,3-DCB
1,3-dichlorobenzene
- 1,4-DCB
1,4-dichlorobenzene
- MCB
monochlorobenzene
Contribution No. 631, Research Institute, Agriculture Canada, University Sub Post Office, London, Ontario N6A 5B7 相似文献
11.
Various Spirulina strains were assayed for their productivity of -linolenic acid (Lnn). Spirulina platensis ARM-346 was found to accumulate large amounts of Lnn. Urea as a nitrogen source was found to be most effective giving a yield of 13.5 mg Lnn/g dry cell mass. With increase in temperature the Lnn content was found to increase along with biomass. The optimum temperature for maximum Lnn and biomass production was found to be 35°C. The Lnn content was highest at 0.06% (w/v) NaCl and 0.07% (w/v) K2HPO4. Cells cultivated in the orange region of the electromagnetic spectrum as energy source showed a high content of Lnn, and there was less biomass compared to cells grown in red light. When the culture was left in the dark for various times, after 144 h it contained about 26% more Lnn than in conventionally cultivated cells. 相似文献
12.
Elisabeth Tschermak-Woess Gertrude Hasitschka-Jenschke 《Plant Systematics and Evolution》1958,104(4-5):577-582
Zusammenfassung In den Fäden der GrünalgenMicrospora amoena undSpirogyra crassa wechseln geschlossene Abschnitte von eigentlich ruhenden Zellen mit Abschnitten von präprophasischen, das sind Mitose-bereiten, mitotisch aktiven und posttelophasischen, also unmittelbar nach der Mitose stehenden Zellen ab. Nur ausnahmsweise schieben sich Zellen des einen Typus in Abschnitte von Zellen des anderen Typus ein.Dieses Verhalten wird hypothetisch mit dem Auftreten und der Weiterleitung teilungsinduzierender Hormone erkärt. Daß die Teilungsstadien einschließlich der vor- und nachmitotischen Stadien nicht entsprechend einem Gefälle streng geordnet aufeinanderfolgen, beruht wahrscheinlich auf der Verschiedenartigkeit der äußeren und inneren Faktoren, die auf die einzelnen Zellen einwirken. Genealogische Faktoren spielen offenbar eine untergeordnete Rolle. 相似文献
13.
An efficient and reliable micropropagation system for Persian clover (Trifolium resupinatum L.) was developed using different explants and media. Node, hypocotyl and cotyledonary node explants were cultured on Murashige and Skoog (MS) medium supplemented with combinations of either 6-benzyladenine (BA) and indole-3-butyric acid (IBA) or BA, Kinetin (KIN) and IBA. Direct multiple shoots developed within 6weeks in all explants in most media tested. The best shoot multiplication capacity was obtained from cotyledonary node explants on MS medium containing 7.1M BA and 1M IBA or 14.1M BA and 1M IBA. Elongated shoots were rooted on either MS medium alone or combination with different concentrations of indole-3-butyric acid (IBA), indole-3-acetic acid (IAA) and -naphthaleneacetic acid (NAA). High rooting was achieved in half strength MS medium containing 8M IBA. 相似文献
14.
Dr. Kunihiko Fukushima 《Biological cybernetics》1973,12(2):58-63
A model of associative memory for time varying spatial patterns is proposed and simulated on a digital computer. This is a network composed of many neuron-like elements, and shows an ability for associative memory similar to that of the brain.Suppose a number of sequences of spatial patterns are presented to this network, for example, 12345, ABC, and so on. Then, these patterns are memorized in the network. After that, if any part of one of these sequences, say 23, is presented to the circuit, the rest of the sequence, 45, is recalled following to it. It resembles to such a situation — if we hear a part of a melody which we have memorized in the past, the rest of the melody is recalled even after it is stopped half-way. Although the recalled patterns are not always 100% correct, they are not completely destroyed even if the presented patterns are imperfect. 相似文献
15.
The effect of estradiol, hydrocortisone and progesterone on 3,20-and 3,17-hydroxysteroid dehydrogenase (HSD) in mutants of Streptomyces hydrogenans was compared to the steroid response of the wild type. Mutants were defective in arginine biosynthesis and/or aerial mycelial formation and lacked both enzymes or only 17-HSD. Some 17-HSD mutants had lost the ability to be induced by estradiol, by progesterone or by both. Some 20-HSD mutants had lost the ability to be induced by hydrocortisone, by progesterone or by both. Non-inducibility of 17-and 20-HSD by progesterone was not co-ordinate. An additional study of the growth phase-dependent enzyme activity of the wild type after induction with estradiol, hydrocortisone and progesterone was performed.Non-standard abbreviations 17-HSD
3,17-Hydroxysteroid dehydrogenase (EC 1.1.1.51)
- 20-HSD
3,20-hydroxysteroid dehydrogenase (EC 1.1.1.53)
- AO
acridine orange
- EBr
ethidium bromide
- EMS
ethyl methanesulfonate
- MNNG
N-methyl-N-nitro-N-nitrosoguanidine 相似文献
16.
Claire D. F. Parsons 《Culture, medicine and psychiatry》1984,8(1):71-93
Idioms of distress refers to the popular expression of emotional tension that arises in the relationship between sickness and kinship. By reference to case studies and discussions among the Polynesian people of Tonga, the author shows where such tension arises and how it influences the sickness process. Sickness is necessarily a collective phenomenon which can best be understood not simply as a clinical event, but as an experience that is part of the experience of family. Various ways of expressing distress as a reflexive encounter between personal and cultural meaning systems are reviewed, as are several new concepts such as doing sickness as kinship, and turning in the process of decision making in the kinship management of sickness. The explanatory models of sickness in Tonga are shown to encompass culturally sanctioned expressions of distress as part of the adaptive coping mechanisms in that society. Distress frequently emerges in somatic form, as a number of studies have shown. However, the author emphasizes the kinship meaning of sickness, kinship management and sickness therapy, the adaptive process of idiomatic expressions of distress, which are expanded here and offered as potential avenues for elaboration in other cultural milieu. Two aspects of the notion idioms of distress are noted, and the phenomenon is understood as a process which acts as a prime mover in social change. 相似文献
17.
By adding 50% (v/v) filtered culture broth to fresh MS medium, the specific growth rate of Panax notoginseng was increased from 0.046 d–1 to 0.068 d–1, and the polysaccharide production and productivity reached 1.21 g l–1 and 61 mg/(ld), respectively, which were 1.3- and 2.3-fold of the control. Further supplementation of the conditioned medium with sucrose, ammonium, nitrate and phosphate gave a cell density of 13.7 g l–1 and a specific growth rate of 0.086 d–1. Polysaccharide production was 1.65 g l–1 and the productivity was 78 mg/(ld). 相似文献
18.
Four patients with ovarian cancer received 20 mg of sizofiran, a -1,3-glucan (molecular weight: 450,000), intramuscularly one day before and 4, 7, 11, 14, 18 and 21 days after second look laparotomy and recombinant interferon- (rIFN-) intraperitoneally on the day of second look laparotomy and 4, 7, 11, 14, 18 and 21 days thereafter.The peritoneal cavity was washed with physiological saline and peritoneal macrophages (Mø) were isolated. The number of Mø increased 30-1600 times during the treatment period. The concentrations of interleukin-1, interferon-, tumor necrosis factor and prostaglandin E2 were also found increased in the supernatant fluid of Mø cultured for 24 hours with 10 µg/ml of lipopolysaccharide. The present study demonstrated that the activation of peritoneal Mø could be maintained and its number was increased by repeated dosing of sizofiran and rIFN- in combination every three or four days in patients with ovarian cancer. Peritoneal Mø thus activated may exert an antitumor effect on ovarian cancer. 相似文献
19.
-N-Acetyl-d-hexosaminidase from Aspergillus oryzae catalysed the stereo- and regiospecific formation of the 6-O-benzylated disaccharide derivatives GalNAc1-3(6- OBn)Gal-SEt and GlcNAc1-3(6-OBn)Gal-SEt, which were obtained in transglycosylation reactions employing ethyl 6- O-benzyl-1-thio--d-galactopyranoside as acceptor. Preparative amounts of the chitobiose derivative GlcNAc1- 3GlcNAc-OPhNO2-p was prepared as well. - N-Acetyl-d-hexosaminidase from bovine testes catalysed the specific synthesis of GlcNAc1-3(6-OBn)GlcNH2-SEt and GalNAc1-3(6-OBn)GlcNH2-SEt, employing ethyl 2-amino-6-O-benzyl-2-deoxy-1-thio--d-glucopyranoside as acceptor. -d-Glucuronidase from E. coli was found to catalyse the formation of GlcA1-3(6-OBn)GlcNH2- SEt employing the same acceptor. 相似文献
20.
Wilson IB 《Glycoconjugate journal》2001,18(6):439-447
Recently, it has been found that plants, including tomato (Lycopersicon esculentum), express the Lewis-a epitope, Gal1,3(Fuc1,4)GlcNAc, on some N-glycans. By searching the EST database, it was possible to identify a tomato cDNA encoding a protein, designated FucTC, of 413 amino acids with homology to plant and mammalian 1,3/4-fucosyltransferases. The cDNA was expressed in Pichia pastoris and the recombinant enzyme was found to transfer fucose from GDP-Fuc (Km 16 M) to lacto-N-tetraose (Gal1,3GlcNAc1,3Gal1,4Glc; Km 80 M) as well as to 1,3- and 1,4-galactosylated N-glycans. It is concluded that FucTC is responsible for the biosynthesis of Lewis-a on N-glycans in tomato. 相似文献