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1.
A method is presented for generating pairs of textures for which the statistics of intersection with any collinear set of points placed at random on either texture are the same. The constraint that such Buffon needle statistics be identical is stronger than identity of second-order statistics. Nonetheless, many such texture pairs are effortlessly distinguishable. An example is given of such a texture pair, whose components are composed of either congruent ellipses or circles of various radii. The discriminability of such texture pairs implies that adequate models for human texture preception must contain local nonlinearities which receive input from non-collinear points.  相似文献   

2.
A contextualizing image (CI) is a powerful central image of a dream which appears to contextualize (provide a picture-context for) the dreamer's emotion. For instance, dreamers who have experienced any serious traumatic event sometimes dream, I was overwhelmed by a tidal wave. This appears to picture their feeling of terror and/or vulnerability.A scoring system for CIs is examined here and is applied to dreams and daydreams supplied by 40 students. Two raters scoring dreams on a blind basis showed good inter-rater reliability. Recent dreams were shown to have more as well as more intense CIs than recent daydreams; likewise, dreams that stand out had more intense CIs than daydreams that stand out. Students with thin boundaries had more and more intense CIs than students with thick boundaries in their recent dreams and nightmare, but not so clearly in dreams and nightmares that stand out. The emotions judged as contextualized by the powerful images tended towards fear/terror and helplessness/vulnerability in dreams (especially in dreams that stand out) whereas emotions contextualized by images in daydreams showed a wide range with no clusters.  相似文献   

3.
The paper characterizes Darwin's theory, providing a synthesis of recent historical investigations in this area. Darwin's reading of Malthus led him to appreciate the importance of population pressures, and subsequently of natural selection, with the help of the wedge metaphor. But, in itself, natural selection did not furnish an adequate account of the origin of species, for which a principle of divergence was needed. Initially, Darwin attributed this to geographical isolation, but later, following his work on barnacles which underscored the significance of variation, and arising from his work on botanical arithmetic, he supposed that diversity allowed more places to be occupied in a given region. So isolation was not regarded as essential. Large regions with intense competition, and with ample variation spread by blending, would facilitate speciation. The notion of place was different from niche, and it is questioned whether Darwin's views on ecology were as modern as is commonly supposed. Two notions of struggle are found in Darwin's theory; and three notions of variation. Criticisms of his theory led him to emphasize the importance of variation over a range of forms. Hence the theory was populational rather than typological. The theory required a Lamarckian notion of inheritable changes initiated by the environment as a source of variation. Also, Darwin deployed a use/habit theory; and the notion of sexual selection. Selection normally acted at the level of the individual, though kin selection was possible. Group selection was hinted at for man. Darwin's thinking (and also the exposition of his theory) was generally guided by the domestic-organism analogy, which satisfied his methodological requirement of a vera causa principle.  相似文献   

4.
It is shown that the utility of usual circular line source models is highly questionable. A line source model related to arbitrary cross-sections is given and essential differences between the source strength of the circular and non-circular model are found in the case of fairly flat elliptic fibers.  相似文献   

5.
Salmon gonadotropin (GTH II) is a heterodimeric glycoprotein hormone ( and II subunits), serving as a maturational GTH, and is produced in a specific gonadotropic cell-type (GTH II-cells) containing small granules and large globules. In trout GTH II-cells, double immunolabeling for the - and II-subunits shows that colocalization of the - and II-immunolabeling is confined to the small granules, indicating storage of functional GTH II. On the other hand, -immunolabeling is absent in the large globules, even though II labeling is abundant throughout the period of seasonal gametogenesis. The -specific antiserum recognizes the intact -subunit as well as the reduced and deglycosylated -subunits by immunoblotting. These results indicate that an accumulation of the II-subunit is specifically generated in the large globules of these cells. In fact, with sexual maturity, the quantity of II-subunits becomes elevated in the trout pituitary due to a marked increase in GTH II-cells containing many large globules. However, the derivation and function of the large globules and the fate of their contained II-subunits remains unknown.  相似文献   

6.
Mattres  Dieter 《Zoomorphology》1962,51(4):375-546
Ohne ZusammenfassungAlphabetisches Verzeichnis der im Text gebranchten Abkürzungen AK Anbieten der Kopfgrube () - AR-seitig außenrandseitig (auf Elytre bezogen) - EO Elytralorgan (EO-Arten = Arten mit Elytralorganen im männlichen Geschlecht) - f Flucht () - F Flucht () - FA, fa frontale Auseinandersetzung (, ) - FS, fs Fühlertrillern bzw. Frontalspiel (, ) - gk Grubenknabbern () - IR-seitig innenrandseitig (auf Elytre bezogen) - K Kopulation - KG Kopfgrube (KG-Arten = Arten mit Kopfgrube im männlichen Geschlecht) - KI Abdomenkitzeln () - KV Kopulationsversuch () - LP-Feld den weiblichen Labialpalpen korreliertes Drüsenporenfeld - MP-Feld den weiblichen Maxillarpalpen korreliertes Drüsenporenfeld - 180 Drehung des um 180° - ob Organbeißen () - ok Organknabbern () - OZ Organzuwendung () - P Prüfung der Kopulationsbereitschaft durch - RB rückwärtige Berührung durch - SLV Seitwärtslauf nach vorn () - SLH Seitwärtslauf nach hinten () - U Umrundung () - vl Vorwärtslauf () - 180 Drehung des um 180° Habilitationsschrift.  相似文献   

7.
Maximum inhibition of Glycine max, cv. Essex seed germination occurred at 10 g/ml following 72 hr imbibition in constant light. Seeds imbided 108 hr in constant darkness at this concentration showed a 20% rise in germination over that of the control. Imbibition of G. max, cv. Williams seeds in either light or dark for 96 hr did not suppress germination. Imbibition of Essex seeds in either light or dark at 2.5 through 10 g/ml stimulated root elongation except for 10 g/ml at 96 hr (light). Maximum inhibition of Williams root elongation under constant light was at 48 and 72 hr with 10 g/ml. Statistically significant differences in cotyledon, leaf and stem lengths between non-treated (NT) and treated (T) seedlings were not found except for Williams stem length at 2.5 / ml. Root elongation was stimulated 1.2- and 1.1-folds, respectively, at 5.0 (Essex) and 2.5 (Williams) g/ml. Toxin at 2.5 through 10.0 g/ml did not markedly alter either cotyledon or leaf widths with the exception of Williams leaf width at 2.5 g/ml. Medium supplementation with 2.5 through 10.0 g/ml resulted in cotyledon, leaf and root weight enhancements for Essex seedlings. Stem weight was not markedly affected. An 18% rise in Williams cotyledon weight above that of the control was seen at 2.5 g/ml. Williams leaf weights were increased 1.75- and 1.25-folds, respectively, at 2.5 and 10.0 g/ml. Aflatoxin B1, at 2.5 g/ml promoted Williams stem and root elongation 1.20- and 1.09-folds, respectively. Most of the radioactivity from 65Zn-ZnCl2 recovered within organs was found within Essex roots for both T and NT seedlings. A higher amount of radioactivity was recovered within roots at each toxin concentration than was without toxin. However, this was not statistically significant. Significant differences in the distribution of radioactivity within roots between NT and T Williams seedlings were not observed. Generally, AFB1 failed to affect significantly these two varieties of soybeans based on the tests relating to germination, growth and radiolabel uptake.  相似文献   

8.
Summary The content of free amino acids was determined in erythrocytes of adult Leghorn (Lg, White Rock (WR) and Cornish (Cr) hens, bred under identical conditions. The concentration of total amino acids was twice as high in the erythrocytes as in plasma, amounting to 396 m/100 ml, 424 m/100 ml and 475m/100 ml in White Rock, Cornish and Leghorn hens, respectively.Significant differences were found in the ratio of basic amino acids to acidic amino acids. These values were 0.76, 1.75 and 3.19 in White Rick, Leghorn and Cornish hens, respectively; in the plasma of all 3 breeds the ratio was 1. Statistically significant interbreed differences were expressed more distinctly in erythrocyte than in plasma amino acid concentrations. For absolute concentrations the differences were significant in the case of 9 amino acids.  相似文献   

9.
Summary In a lactic acid fermentation by Streptococcus faecalis, the specific consumption rate of glucose (v) and the specific production rate of lactic acid () were represented by the following simple equations as functions of the specific growth rate (): 1/=(1/) + 1/ = (1/) + By use of data from a batch culture, these two equations were derived from enzyme kinetics of the product inhibition. These equations were successfully applied to the results of batch culture and chemostat culture. In addition, calculation of ATP yield by these equations agreed with the experimental results better than the conventional Leudeking-Piret type equation, which includes two terms associated with growth and not with growth. Correspondence to: H. Ohara  相似文献   

10.
Summary A single injection of -interferon (-IFN) (30 000 units/mouse), a major biological modifier of natural killer (NK) cytolytic activity, strongly stimulated NK activity in normal mice, as expected, while the same treatment did not statistically alter the NK response in cyclophosphamide (CY)-suppressed animals.We investigated the possibility of thymosin 1 cooperating with -IFN in boosting NK activity in CY-suppressed animals.The results show that treatment with thymosin 1 (200 g/kg) for 4 days, followed by a single injection of -IFN 24 h before testing, strongly restored NK activity in CY-suppressed mice. Thymosin 1 was, moreover, able to accelerate the recovery rate of NK activity in bone marrow reconstituted murine chimeras.Taken together the data support the concept that the synergic effect between thymosin 1 and -IFN could be the result of effects on differentiation of the NK lineage at different levels.  相似文献   

11.
Feulgen and silver-stained karyotypes and meiosis of two triploid viviparous onion forms (Allium cepa var.viviparum), the Croatian Ljutika and the Indian Pran, were comparatively analyzed. The results of chromosome measurements show that Ljutika and Pran are karyologically not identical, although significant similarities were found in the morphology of their chromosomes. Five geographically distant clones of Ljutika showed good agreement in the number and gross morphology of the chromosomes and in the number and position of NORs and interphase nucleoli. Heterotrivalents were predominant in meiosis of Ljutika but a relatively high frequency of higher multivalents together with univalents and bivalents were also observed. The relationship between Ljutika and Pran and their possible origin are discussed.  相似文献   

12.
The primary structure of Rose-ringed Parakeet hemoglobin -chain was established, completing the analysis of this hemoglobin. Comparisons with other avian -chains show variations smaller than those for the corresponding -chains. There are 11 amino acid exchanges in relationship to the only other characterized psittaciform -chain, and a total of 35 positions are affected by differences among all avian -chains analyzed (versus 61 for the -chains). At three positions, the Psittacula -chain has residues unique to this species. Three 11 contacts are modified, by substitutions at positions 51, 116, and 125.  相似文献   

13.
Given a finite set of strings of elements (e.g. words or syllables written in terms of letters, which may be true alphabetic symbols, or markers for features which put together form the word describing an object), the problem is posed of memorizing the strings not in lexicographic order, but by grouping them into classes, each of which can be taken as an entry into a multilayered, fast-access memory; this is equivalent to memorizing, rather than the strings, the structural rules which characterize them. This problem is solved by means of a heuristic algorithm, which gives results that stay invariant under arbitrary permutations of the elements; heuristics may affect optimality, not exactness of the solution, and provides considerable gains in computing costs. The exposition, for convenience of the reader, is self-contained, although this work is part of a more general program on form and language analysis.  相似文献   

14.
The conformational properties of the oligosaccharide chain of GM1 ganglioside containingN-glycolyl-neuraminic acid, -Gal-(1-3)--GalNAc-(1-4)-[-Neu5Gc-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer, were studied through NMR nuclear Overhauser effect investigations on the monomeric ganglioside in dimethylsulfoxide, and on mixed micelles of ganglioside and dodecylphosphocholine in water. Several interresidual contacts for the trisaccharide core--GalNAc-(1-4)-[-Neu5Gc-(2-3)]--Gal-were found to fix the relative orientitation of the three saccharides, while the glycosidic linkage of the terminal -Gal-was found to be quite mobile as the -Gal-(1-3)--GalNAc-disaccharide exists in different conformations. These results are similar to those found for two GM1 gangliosides containingN-acetyl-neuraminic acid and neuraminic acid [1].Abbreviations Ganglioside nomenclature is in accordance with Svennerholm [23] and the IUPAC-IUB Recommendations [24] GM3(Neu5Ac) II3Neu5AcLacCer, -Neu5Ac-(2-3)--Gal-(1-4)--Glc-(1-1)-Cer - GM3(Neu5Gc) II3Neu5GcLacCer, -Neu5Gc-(2-3)--Gal-(1-4)--Glc-(1-1)-Cer - GM1(Neu5Ac) II3Neu5AcGgOse4Cer, -Gal-(1-3)--GalNAc-(1-4)-[-Neu5Ac-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer - GM1(Neu5Gc) II3Neu5GcGgOse4Cer, -Gal-(1-3)--GalNAc-(1-4)-[-Neu5Gc-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer - GM1(Neu) II3NeuGgOse4Cer, -Gal-(1-3)--GalNAc-(1-4)-[-Neu-(2-3)]--Glc-(1-1)-Cer - GD1a IV3Neu5AcII3Neu5AcGgOse4Cer, -Neu5Ac-(2-3)--Gal-(1-3)--GalNAc-(1-4)-[-Neu5Ac-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer - GalNAc-GD1a IV4GalNAcIV3Neu5AcII3Neu5AcGgOse4Cer, -GalNAc-(1-4)-[-Neu5Ac-(2-3)]--Gal-(1-3)--GalNAc-(1-4)-[-Neu5Ac-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer - Neu neuraminic acid - Neu5Ac N-acetyl-neuraminic acid - Neu5Gc N-glycolyl-neuraminic acid - Cer ceramide  相似文献   

15.
On age morphological changes of males of Chydoridae (Cladocera)   总被引:2,自引:2,他引:0  
N. N. Smirnov 《Hydrobiologia》1967,30(3-4):555-571
Summary Young and adult males of 11 species of Chydoridae are studied, their figures being published here (fig. 1–15). The necessity is stressed to distinguish young forms of males and gynandromorphic individuals.Pleuroxus balatonicus is considered to be described from the population ofPleuroxus unicatus having under Balaton Lake conditions retarded transformation of young males into adult form, and accordingly having unusually numerous young males. \qO\qs\qn\qo\qv\qn\qy\ye \qr\ye\qz\qu\ql\Qj\qt\qa\qt\qy 11 (. 1–15). . , Pleuroxus uncinatus , Pleuroxus balatonicus.  相似文献   

16.
Christian Dumas 《Planta》1977,137(2):177-184
Chromatographic (thin-layer, gas column, column chromatography) analyses of neutral lipids and fatty acids of reproductive tissues of Forsythia intermedia Zab., a self-incompatible species, were performed with two objectives in mind: 1. To determine whether there is a qualitative evolution of the different classes of lipids and fatty acids that could be correlated with the three functional stages observed during previous histochemical and ultrastructural studies. The stigmatic exudate and intracellular accumulations consist mainly of neutral lipids. 2. To compare the lipid composition of the stigma (both thrum and pin forms) with that of the style, the ovary, and the anther, and to investigate the possible existence of a stigma-specific lipid compound. Stigmatic neutral lipids are found mostly in a glyceridic mixture probably containing hydrocarbons and terpenes. The fatty acids identified are between C:7 and C: 12, with the maximum unsaturated form being a C: 18. During the secretory process there is no great qualitative diference between the neutral lipids and fatty acids found in the stigmas of thrum and pin forms. Sterols are present in styles, ovaries, and anthers, but not in stigmas. They represent the only difference in the lipid composition of these various floral structures.  相似文献   

17.
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   

18.
The main contribution of this paper is to propose a new cluster maintenance algorithm and a companion cluster initialization algorithm based on a number of interesting and novel properties of diameter-2 graphs. The initialization algorithm naturally blends into cluster maintenance, showing the unity between these two operations. We refer to our algorithms as tree-based since they depend on a spanning tree maintained at various nodes. Unlike the vast majority of published clustering algorithms, our algorithms are cluster-centric, as opposed to node-centric, and work in the presence of node mobility. Extensive simulation results have shown the effectiveness of our algorithms when compared to other clustering schemes proposed in the literature.Lan Wang received his B.S. and M.S. degrees in computer science from Harbin Engineering University, China in 1992 and 1995, respectively. From 1995 to 1999, he worked as a software engineer at the System Engineering Research Institute of CSSC, Beijing, China. He is currently a PhD student at the Computer Science Department of Old Dominion University.Stephan Olariu received the M.Sc. and Ph.D. degrees in computer science from McGill University, Montreal, Canada in 1983 and 1986, respectively. In 1986 he joined the Computer Science Department at Old Dominion University where he is now a full professor. He has published extensively in various journals, book chapters, and conference proceedings. His research interests include wireless networks and mobile computing, parallel and distributed systems, performance evaluation, and medical image processing. Prof. Olariu serves on the editorial board of several archival journals including IEEE Transactions on Parallel and Distributed Systems, Journal of Parallel and Distributed Computing, International Journal of Foundations of Computer Science, Journal of Supercomputing, International Journal of Computer Mathematics, VLSI Design, and Parallel Algorithms and Applications.  相似文献   

19.
Byers  D.M.  Rosé  S.D.  Cook  H.W.  Hao  C.  Fedoroff  S. 《Neurochemical research》1998,23(12):1493-1499
Many events involved in activation of microglia and leukocytes by lipopolysaccharide (LPS) are mediated by protein kinase C (PKC), and we have recently demonstrated that a major PKC substrate, MARCKS-related protein (MRP), is selectively induced by LPS in murine microglia. In microglia from LPS-nonresponsive (C3H/HeJ) mice, induction of MRP and secretion of CSF-1 required much higher LPS concentrations (100 ng/ml) than in normal (C3H/OuJ) microglia (10 ng/ml). By contrast, TNF production was not significantly increased in C3H/HeJ microglia even at 1 g LPS/ml. Microglia expressed PKC isoforms , , , and (but not and ); PKC isoform levels were similar in both normal and C3H/HeJ microglia and no significant change in response to LPS was noted. Our results indicate that LPS alters PKC substrate (rather than kinase) expression, and that the Lpsd mutation in C3H/HeJ mice differentially affects regulation of several gene products implicated in microglial function.  相似文献   

20.
Regulation of β-xylosidase formation by xylose in Trichoderma reesei   总被引:1,自引:0,他引:1  
The soft-rot fungus Trichoderma reesei forms -xylosidase (EC 3.2.1.37) activity during cultivation on xylan and xylose, but not on glucose. When mycelia precultivated on glycerol were washed and transferred to fresh medium without a carbon and nitrogen source, -xylosidase formation was induced by xylan, xylobiose and xylose. A supply of 4 mm xylose and a pH of 2.5 provided optimal conditions for induction. -Xylosidase accounted for the major portion of total extracellular protein under these conditions, and could be purified to physical homogeneity by a single anion exchange chromatography step. A recombinant strain of T. reesei that carries multiple copies of the homologous xylanase II-encoding gene has a six-fold increased xylanase activity, but forms comparable -xylosidase activities. This shows that the rate of xylan hydrolysis has no effect on the induction of -xylosidase. Methyl--d-xyloside inhibited -xylosidase competitively and was a weak -xylosidase inducer. The induction by xylobiose and xylan was strongly enhanced by the simultaneous addition of methyl--d-xylosidese and xylan or xylobiose. The results suggest that a slow supply of xylose is a trigger for -xylosidase induction.  相似文献   

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