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1.
    
Zusammenfassung Es wird über Laboratoriums-Versuche mit 3 verschiedenen Typen von Bacillus thuringiensis-Präparaten an Honigbienen berichtet: (a) mit dem Sporen- Endotoxin-Komplex, (b) mit vegetativen Zellen und (c) mit von diesen produziertem wasserlöslichem thermostabilem Exotoxin. Während Sporen-Endotoxin-Präparate (geprüft an 5 Varietäten) in den für die Bekämpfung von Lepidopteren-Raupen benutzten Dosierungen ungefährlich sind, wirken hohe Dosen toxisch, wenn sie im Futtersaft adulten Bienen appliziert werden. Ein durch vegetative Zellen bedingter nachteiliger Einfluß auf Bienen wurde nicht beobachtet. Das Exotoxin welches von bestimmten Varietäten (z.B. var. thuringiensis) in die Kulturflüssigkeit abgegeben wird, wirkt auf Bienen giftig, wenn es im Futtersaft und als Konzentrat verfüttert wird.
Summary In laboratory trials the effects of three types of preparations of Bacillus thuringiensis were tested on adult honey bees (Apis mellifera L.): (a) the spore-endotoxin-complex, (b) vegetative cells, and (c) the exotoxin. Though spore-endotoxin-preparations (of 5 varieties) were harmless to bees in dosage used for biological control, higher dosages applied in sugar solution were toxic. By using a medium concentration of vegetative cells no disease symptoms could be observed on bees. But the water-soluble thermostable factor, the so-called exotoxin, which is produced by the vegetative cells of several varieties (for example var. thuringiensis), was toxic to bees after feeding. The consequences of these observations are discussed.
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2.
Psychological parameters of mental activity (30 in total) and their genetic determination were studied in 67 families of schizophrenia patients (67 patients, 107 parent, and 30 sibs). Abnormalities of most of the examined characteristics were found in both the patients and their healthy relatives. Parameters of attention shifting and emotionality revealed the largest genetic component (25–75 and 17–98%, respectively) in all analyzed groups of relatives (probands–affected sibs, probands–healthy sibs, healthy parents–healthy children, affected parents–affected children). Significant impact of genetic factors was also found in parameters stability of attention under conditions of continuous concentration, mediated retention span productivity of voluntary retention by reproduction data, personal anxiety level, reflection of unusual social groups, and self-assessment. The relationships among the characteristics examined in the system of mental activity were established by means of cluster analysis. The results of this study can be used in medical genetic counseling for identifying subjects at high risk for schizophrenia.  相似文献   

3.
Summary Changes in the proximal stump of axons of divided rat sciatic nerves in the first 6 weeks after nerve section were studied, particularly in terms of alterations in the organelle content, axoplasmic ultrastructure and the diameter of the axons. A variety of organelle types were observed; quasi-membranous structures, multivesicular bodies, dense bodies, vesicles and tubules, dense cored vesicles and alveolate vesicles: their identification and the functional implications of their presence are discussed. Alterations in the ultrastructure of the stained elements of the axoplasm are described. Axons containing excess organelles were divided into classes, comprising myelinated axons; and supergiant, giant and conventional non-myelinated axons. Temporal changes in these axons are described. The characteristics of the various classes of apparently non-myelinated axon are considered in terms of their identification as regenerating terminal sprouts of myelinated axons, segmentally demyelinated axons, sections through abnormal nodes of Ranvier or merely non-myelinated axons. The structure of axons in regenerating units is described. Changes in the neurofilament microtubule ratio of small axons without excess organelles are demonstrated, and spiralling of neurofilaments in some myelinated and non-myelinated axons with normal axoplasmic ultrastructure is illustrated and discussed.Medical Research Council Scholar.McLoughlin Fellow.The authors have great pleasure in acknowledging the expert technical assistance of Mrs. Frances Burton. G. W. would also like to thank the British Medical Research Council, the Wellcome Trust and LEPRA (British Leprosy relief association) for financial assistance without which this work could not have been completed.  相似文献   

4.
David Habeshaw 《Planta》1973,110(3):213-226
Summary Evidence is presented that the size and activity of sinks for the products of photosynthesis exert a large measure of control over carbohydrate levels in the leaves of the sugar beet plant. Further data is presented to show that a correlation exists between the level carbohydrate in the leaf and the rate of photosynthesis. The rate of photosynthesis can thus be linked directly to the sinks of the plant by their ability to control rates of translocation from leaves.  相似文献   

5.
Zusammenfassung In Temperaturkabinen wird die Fortpflanzungspotenz von Myzus persicae (Sulzer) (Herkunft Groß-Lüsewitz) bei Dauertemperaturen von 15 bis 30° auf Kohlrüben (Brassica napus subspec. rapifera) untersucht.Eine Populationsanalyse nach Birch (1948) (intrinsic rate of increase) ergab den höchsten Wachstumsfaktor bei Dauertemperaturen zwischen 20 und 23°.Dauertemperaturen >25° führten zu einer starken Minderung der. Fortpflanzungspotenz. 30° ist die obere Grenze der Fortpflanzung der untersuchten Myzus persicae-Population.
The reproductive potential of the peach-potato aphid (origin Gross-Lüsewitz) was studied at temperatures between 15° and 30° in constant temperature chambers. They were cultivated on Swede (Brassica napus spp. rapifera) which stood in Knop's nutrient under gauze cloches in petri dishes. The production of juvenile larvae and the mortality of the mothers was measured daily. The total of all larvae (including those which were dropped) and the total of larvae on the leaf were separately enumerated. The larvae on the leaf were designated as viable larvae. A population analysis using Birch's method showed a maximum value for the growth factor k (difference between birth and mortality rates) of 23° for the total of all larvae, and of 20° for the viable larvae (Fig. 6). The daily relative growth-ratio was at the same temperatures respectively 1.36 and 1.34 (Table IV). Optimum development of M. persicae on swedes occurs thus between 20° and 23°. The percentages of viable larvae which add to the net production of total larvae are 53, 61, 30, and 24 (Table III) at temperatures of 15, 20, 25, and 30° respectively. The average length of a generation was 18.5 days at 15° and less than 13 days at 28 to 30° (Fig. 5). The multiplication rate per generation was 38 at 15°, 48 at 20°, but only 5.5 at 30° (Fig. 4). The time of development from first-stage larva to adult was 12.5 days at 15°, 5 days at 28° and 6 days at 30° (Table VII). The upper limit, where a weak multiplication was still possible, was at 30°. It is concluded that in regions where such limiting temperatures occur during some part of the day, the temperature can be the major regulating factor of the insect populations.
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6.
Summary Stereology and semi-automatic image analysis were used with the aim of comparing the structure of parathyroid glands from untreated adult Mongolian gerbils fixed by immersion with those fixed by perfusion. Subclassification of the chief cells based upon the staining affinity or electron density of the cytoplasm was readily performed only in glands fixed by immersion, and so-called atrophic cells were observed only in these glands. The atrophic cells were often surrounded by light chief cells. In glands fixed by perfusion, light chief cells were only rarely encountered. A significant difference between glands fixed by immersion and those fixed by perfusion was found only with regard to the form of cells and nuclei, those fixed by perfusion being more spherical. When comparing individual cells within glands fixed by immersion, light chief cells were more spherical and had a significantly larger nuclear and cellular size, and a lower mitochondrial volume density than the intermediate/dark chief cells. Otherwise there were no significant differences in any of the parameters investigated. These data indicate that occurrence of socalled light chief cells and atrophic cells is a result of improper fixation. The results of this study do not favour the concept of a functional cycle with a simultaneous occurrence of active and inactive cells within parathyroid glands.  相似文献   

7.
Summary The temporal muscles of the guinea pig show a sexual differentiation reflected in their histochemical enzyme pattern. Using histochemical methods for mitochondrial (SDH, -GPDH), and glycolytic enzymes (phosphorylase, LDH) it could be shown, that in adult animals the male muscle is a white muscle with marked activity of glycolytic enzymes, the female muscle a red muscle displaying high activity of mitochondrial enzymes. This differential enzyme pattern can be converted by the application of testosterone to the female type during the postnatal development. The male sex hormone thus affects the histochemical enzyme pattern of the muscle, converting the red, female into a white, male muscle in the female guinea pig.  相似文献   

8.
We have used restriction fragment length polymorphism (RFLP) analysis and DNA sequencing to characterize two distinct DRB1 alleles expressed on DRw52 and DQw7-associated haplotypes but not readily defined by conventional DR serology. These two haplotypes, designated HLA-D HAG and PEV, react variably with DRw13(w6), DRw14(w6), and the more broad DR 3+6 antisera. Analysis of RFLP revealed that HLA-D HAG and PEV are associated with different DRw52 variants, and that HAG is indistinguishable from DRw18(3) haplotypes. Sequencing of the HAG and PEV DRB1 genes showed each to represent novel alleles. Nevertheless, these sequences show similarities with the other alleles of the DR5, w6, and w8 family. HAG (DRB1*1303) appears to have arisen either from two recombinational events involving at least three DRB1 sequences (DRB1*1101, DRB1*0803, DRB1*0401) or from a single recombinational event together with multiple point mutational events. PEV appears to represent a DRB1*1301-1302/DRB1*1101 recombinant allele, with recombination having occured in the region of bases 175 – 198. The results of this study suggest that the DRw52 family haplotypes is derived from a relatively restricted number of ancestral sequences, with diversity among DRB1 alleles within this family arising through gene conversion or recombination events.  相似文献   

9.
On the basis of symposium contributions onChlorella, Hibbertia, Eucalyptus, Ambrosia and on numerical approaches some fundamental problems of (bio)systematics, evolution, and taxonomic categories are discussed: Methods available for analysing affinities; conflicting evidence from phenetic, biochemical, cytogenetic and other analyses; further classification problems in cases of intermediacy, etc. While sibs of various levels and their natural hierarchy often can be objectively defined, this appears impossible for particular taxonomic levels itself (e. g. species). A single objective taxonomic system of organisms is unrealistic. Certain guiding lines for relative and practicable concepts of species and genus are proposed.Presented at the symposium Speciation and the Species Concept during the XIIth International Botanical Congress, Leningrad, July 8, 1975.  相似文献   

10.
The immune system furnishes the organism with the utmost effective defence mechanisms against foreign and changes in self without doing self-harm. However, optimized efficacy in the defence against the immense variety of foreign antigens generates a higher risk for inadvertent self challenge. Such inherent short-comings are the inevitable burden traded for the benefits of an optimally organized defence system. The central molecules involved in specific immune reactions include antigen receptors of B and T lymphocytes, and antigen-presenting proteins encoded by the major histocompatibility complex (MHC; in man HLA). The genetics and evolution of these multigene families is discussed here with respect to their potential contributions to disturbances of self recognition. Simple molecular biological tools and procedures for efficiently screening the immunologically relevant genes are described.Dedicated to Professor Dr. U. Wolf on the occasion of his 60th birthday  相似文献   

11.
Summary Stationary phase cells of strain phr/MC 2 ofE. coli are not photoreactivable but the frequency of UV-induced mutations to low Streptomycine-resistance (S 3, 3/ml) is decreased strongly by illumination with light of fluorescence tubes (310 to 500 nm) after UV-irradiation. Also dark-reversion (DRM) of these mutations due to keeping UV-irradiated cells in saline is observed. Illumination before UV-irradiation decreases the frequency of the mutations (photoprotection against mutation=PPM) to the same extent as the combined action of photoreversion (PRM) and DRM. The lag-phase of cell division is prolonged strongly by illumination from 80 min without light to 150 min by the light-dose of highest activity. The additional lag is nearly the same if the illumination is done before, after or without UV-irradiation; this lag is about additive to the small lag caused by UV. Pre-illumination of the stationary-phase cells does not cause photoprotection against killing (PP), it even decreases the survival after high UV-doses. The observations support the hypothesis that PRM in this strain may be indirect, i.e. caused by the light-induced additional division lag which enhances the dark repair of UV-premutations. Also spontaneous premutations which are apparently present in the stationary-phase cells seem to be influenced by the light in this way.  相似文献   

12.
Zusammenfassung Die Retinula im Ommatidium der Mehlmotte besteht aus einer wechselnden Anzahl (9–12, meist 11) langgestreckter, prismatischer Sinneszellen. Außerdem enthält jede Retinula nahe der Basalmembran im Zentrum zwischen diesen distalen Retinulazellen noch eine basale Retinulazelle. Die Längsachse der Retinula wird von der Achsenstruktur eingenommen, die aus Mikrovilli besteht. Ihr distaler Teil ist der Achsenfaden, der breitere, proximale Teil bildet das Rhabdom. Dieses erscheint im Querschnitt meist vierstrahlig gelappt, da seine Außenseite in Längsrichtung tief gekehlt ist. Der Rhabdomquerschnitt gliedert sich in mehrere Schöpfe parallel angeordneter Mikrovilli (Rhabdomsektoren); jeder Rhabdomsektor besteht aus 1 oder 2 Rhabdomeren. Die basale Retinulazelle entsendet einen kleinen Schopf von Mikrovilli in die proximale Spitze des Rhabdoms. Die distalen Retinulazellen setzen sich proximal in Neuriten fort, welche sich in Einkehlungen der basalen Retinulazelle bzw. der Tracheenendzelle einschmiegen. Jeweils eine Tracheole durchbricht zusammen mit dem Neuritenstrang einer Retinula die Basalmembran; sie verzweigt sich distal zu ca. 30 Tracheolen, die die Retinula umhüllen.Die Kristallkegelzellen grenzen distal an die Cornea; proximal laufen die Kristallkegelzellen eines Ommatidiums in einen gemeinsamen Fortsatz aus, der zwischen den Retinulazellen unmittelbar am Achsenfaden endet. — Nur das helladaptierte Auge wurde untersucht. Hierbei erscheint im distalen Teil der Retinula nur der Achsenfaden lichtdurchlässig, das Cytoplasma der Retinulazellen hingegen von Pigmentgrana durchsetzt und für Licht undurchlässig.
Fine structure of the eye of the meal moth, Ephestia kuehniella Zeller (Lepidoptera, Pyralididae)
Summary In each ommatidium of the meal moth a retinula is formed from a varying number (9–12, mostly 11) of elongated, prismatic sense cells. In addition, a basal retinular cell is situated near the basement membrane in the center of the other (distal) retinular cells. The axis of the retinula is occupied by many microvilli forming the axial structure, the distal section of which is the slender axial thread. Proximally, the axial structure widens (to 8.5 m instead of 1 m in diameter) and is now called rhabdom. Cross sections of the rhabdom mostly look like a petaloid with four petals; this figure is due to longitudinal infoldings along the length of the rhabdom surface. The rhabdom cross section is subdivided into several brushes of microvilli (rhabdom sectors), each one being characterized by an approximately parallel arrangement of its microvilli. One rhabdom sector may be composed of one or two rhabdomeres respectively.The basal retinular cell participates in rhabdom formation through a small brush of microvilli at the proximal end of the rhabdom. Proximally, the distal retinular cells taper into slender neurites which are embedded in grooves at the surface of the basal retinular cell and the tracheal end cell respectively. One tracheole piercing the basement membrane together with the neurites of one retinula branches into about 30 tracheoles surrounding the retinula.The crystalline cone cells touch the cornea; proximally, their cytoplasm forms a point which eventually terminates amongst the distal tips of the retinular cells, immediately at the axial thread.—Our work was restricted to light adapted eyes; in this condition, light transmission in the distal part of the retinula seems to be blocked by retinular cell pigment except inside the axial thread.
Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.  相似文献   

13.
Richard Lewontin's (1970) early work on the units of selection initiated the conceptual and theoretical investigations that have led to the hierarchical perspective on selection that has reached near consensus status today. This paper explores other aspects of his work, work on what he termed continuity and quasi-independence, that connect to contemporary explorations of modularity in development and evolution. I characterize such modules and argue that they are the true units of selection in that they are what evolution by natural selection individuates, selects among, and transforms.  相似文献   

14.
Embryogenetic pathways differ markedly among monotremes, marsupials, and placentals, and their analysis provides information of fundamental importance to recognition of mammalian evolutionary directions. The cap of cuboidal cells of the marsupial late unilaminar blastocyst, generally known as the embryonic area, probably is induced to form (prior to origin of Hensen's node) by signals from earliest hypoblastic cells (anterior visceral endoderm). The thickened cap is a medullary plate of sauropsid terminology because it includes epiblastic cells presumptive to neurectoderm (including neural crest), Hensen's node, primitive streak, and gut endoderm. The remainder of the definitive embryo (i.e., parts of epidermal origin, including ectodermal placodes) derives from squamous ectoderm (surrounding the medullary plate) of the blastocyst's ill-named trophoblastic area. Amniotic ectoderm develops farther distally within the trophoblastic area. The autapomorphic inner cell mass (ICM) of placental mammals is homologous to medullary plate of the marsupial blastocyst plus morphologically undefined, proximal parts of surrounding ectoderm (of the trophoblastic area). Considerations of early cell lineages in marsupials are greatly affected by recognition that the boundary between future embryonic and extra-embryonic tissues does not match the margin of the medullary plate (i.e., embryonic area). Marsupials and monotremes largely conform to sauropsid early embryogenesis, but placentals express, at earliest developmental stages, innovations unique within Amniota that are linked to early establishment of the brain. Neonatal marsupials and hatchling monotremes are extremely altricial and closely comparable anatomically/physiologically; they share a temporal pattern in combining early morphogenesis of craniofacial features (related to suckling) with deferral of telencephalic completion into postnatal/posthatching life. Placentals contrast greatly in establishing the central nervous system prior to rudiments of the cranial skeleton and associated musculature, and they complete essentials of forebrain development before birth. Comparative evidence from transitory periderm suggests that primordial eutherians had extremely altricial hatchlings or newborns, whichever was the mode of early development. Details remain unknown about the origin of the unique specialization of ICM plus encapsulating trophoblast from the more generalized blastula of ancestral synapsids.  相似文献   

15.
Summary The seasonal progression of phenophases in 21 shrub species of the Chilean matorral was analyzed. Five modules or basic units that are responsible for the aboveground architecture of the plants were characterized. These modules appear to be organized in seven different spatial arrangements. In drought-deciduous species a module type with an absolute short shoot with limited apical growth, leafy or spiny, predominated. In evergreen species long shoot and temporal leafy short shoot module types were more frequent. The spatial arrangement of morphologically different modules and the temporal sequence of their formation allow a dynamic interpretation of the modular architecture of the plants.  相似文献   

16.
Résumé Pour rechercher le poireau, Acrolepiopsis assectella doit utiliser des stimulus olfactifs issus du végétal-hôte et notamment les substances soufrées spécifiques. Le pouvoir attractif de l'«odeur» du poireau et celui de différents thiosulfinates et disulfures trouvés dans cette plante sont donc étudiés et comparés par olfactométrie. Le comportement de mâles et de femelles vierges et fécondées est observé, en fonction de l'âge des imagos, pendant la scotophase. Alors qu'un courant d'air sans «odeur» significative déclenche essentiellement l'orientation et l'immobilisation des insectes face au flux, la plus part des mâles et des femelles quel que soit leur état sexuel sont attirés par le courant d'air lorsque celui-ci transporte l'«odeur» du poireau ou les substances volatiles étudiées. La sensibilité à l'«odeur» de la plante-hôte semble se modifier avec l'âge des insectes, les mâles âgés et les jeunes femelles étant les plus attirés. Cependant, ces dernières conservent une forte sensibilité une fois fécondées. Aux âges où l'«odeur» du poireau est la plus efficace, les thiosulfinates déclenchent chez les mâles et les femelles vierges une attraction plus importante que les disulfures, le radical propyle étant plus actif que le méthyle. Le thiosulfinate de dipropyle, labile, très abondant dans le poireau, semble donc avoir un rôle informationnel prépondérant.
Summary To find the leek, Acrolepiopsis assectella uses olfactory stimulants from the hostplant, and specially the specific sulphur compounds. The attractiveness of the leek smell and of different thiosulfinates and disulfides found in this plant were studied and compared in an olfactometer. The behaviour of , and virgin or mated was observed during the scotophase according to to the age of the adults. In a clean air current the insects orient and remain stationary. The majority of and virgin or mated move upwind when the air current bears the leek smell or the voltile sulphur compounds. The sensitivity to the hostplant smell seems to change with the age of the insect, old and young being most attracted. Once mated, the retain a high sensitivity. When the responsiveness to the leek smell is highest (at 1 day and 5 days) the thiosulfinates have a greater effect than the disulfides in both and virgin . The propyl moiety is more active than the methyl one. The labile dipropyl thiosulfinate (propyl propanethiosulfinate), very profuse in the leek, seems to have the major role.
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17.
A novel approach was used to compare male and female recombination rates in wheat. Doubled haploid lines were developed from an F1 using two distinct approaches: the anther-culture technique and the Hordeum bulbosum system, from which sets of lines were developed from male and female meioses, respectively. The genotype of the lines was established at RFLP and isozyme markers polymorphic on chromosomes of homoeologous groups 6 and 7, and male and female linkage maps were calculated using this information. The markers in one segment of chromosome 6B exhibited disturbed segregation frequencies in the anther-culture population. The male and female maps differed significantly in recombination frequency between some markers on two chromosomes, and these were consistent in direction within chromosomes and inconsistent in direction between chromosomes. In two of the four chromosomes studied the male map was much longer than the female map. These results suggest that significant differences may exist in male and female recombination frequencies in bread wheat which are specific to certain chromosomal segments but are inconsistent in direction between chromosomes. Other factors, such as environmental influences, may also be important in creating differences.  相似文献   

18.
Conclusion Even a cursory look at the ethnographic literature on other Northwest Coast societies reveals some striking similarities with the Tlingit way of conceptualizing aristocrats as special persons. Thus the Kwakiutl referred to their chiefs as real or complete people, who were heavier than commoners. The Coast Tsimshian called their highest aristocrats real or ripe persons, in contrast to the low-ranking ones, who were described as unhealed or green. The Coast Tshimshian also referred to their chiefs as strong, heavy, and solid like a rock. The neighboring Gitksan contrasted the chiefs, described as people who were good and clean and stayed put, with the commoners, who were said to be dirty, ignorant, and always moving around. Because spirits of the dead liked to return to persons who were clean and showed respect by giving away wealth and feasts, there was considerable moral and practical pressure on the aristocrats to remain pure, train knowledgeable and clean heirs, and continue potlatching. Finally, among the Haida, rank was tied to a wider system of symbolic classification, associating aspects of food, space, clothing, ritual pollution and the ethic of industry with attributes of seniority.While some of the symbolic associations of aristocratic status are culture specific, others are present in several, if not all, of the NWC cultures. What we need is a comparative symbology of aristocratic status, which would combine the reanalysis of the existing ethnographic data with the introduction of some new materials that can still be obtained in the field. Such work would be the best tribute to Irving Goldman himself and to our common illustrious ancestors—Franz Boas and Marcel Mauss.Sergei Kan is Professor of Anthropology at Dartmouth College.  相似文献   

19.
A. M. M. Berrie  J. Robertson 《Planta》1976,131(3):211-215
Summary Abscisic acid (ABA) has been unequivocally identified as an endogenous component of seeds of Grand Rapids lettuce. Both free and bound ABA levels were followed during imbibition at various temperatures but no clear role for ABA in the imposition of thermodormancy emerged. Furthermore it was apparent that different seed batches showed different ratios of free to bound ABA and patterns of changes. An unsuccessful attempt was made to identify bound ABA, presumed to be the glucosyl ester.Abbreviations ABA abscisic acid - ABA Me ester methyl abscisate - ECD electron capture detector - FID flame ionisation detector - GC-MS combined gas liquid chromatography, mass spectrometry - GLC gas liquid chromatography - PVP polyvinyl-pyrrolidone - TLC thin layer chromatography  相似文献   

20.
K. Das  H. M. Srivastava 《Genetica》1969,40(1):555-565
Observations on morphology, sterility and cytology of some interchangetrisomics obtained from the progeny of radiation induced interchangeheterozygotes in a 6-rowed barley (Hordeum vulgare L.) var. K12 are described. The different interchange trisomics show distinct phenotypic expression and have been classified as bushy, slender, robust, semi-erect and pseudonormal on the basis of their gross morphology, leaf characteristics, awn and spike lengths. All interchange trisomics show pollen and ovule sterility which varies between plants. Meiotic behaviour is described. The five different interchange trisomics appear to have different extra chromosomes.  相似文献   

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