How similar are poxviruses?     

Mezencev R  Mereish K 《Science (New York, N.Y.)》2005,308(5726):1259-1260

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A phenylalanine clamp catalyzes protein translocation through the anthrax toxin pore     

Krantz BA  Melnyk RA  Zhang S  Juris SJ  Lacy DB  Wu Z  Finkelstein A  Collier RJ 《Science (New York, N.Y.)》2005,309(5735):777-781

The protective antigen component of anthrax toxin forms a homoheptameric pore in the endosomal membrane, creating a narrow passageway for the enzymatic components of the toxin to enter the cytosol. We found that, during conversion of the heptameric precursor to the pore, the seven phenylalanine-427 residues converged within the lumen, generating a radially symmetric heptad of solvent-exposed aromatic rings. This "phi-clamp" structure was required for protein translocation and comprised the major conductance-blocking site for hydrophobic drugs and model cations. We conclude that the phi clamp serves a chaperone-like function, interacting with hydrophobic sequences presented by the protein substrate as it unfolds during translocation.  相似文献   

Melatonin suppresses nighttime memory formation in zebrafish     

Rawashdeh O  de Borsetti NH  Roman G  Cahill GM 《Science (New York, N.Y.)》2007,318(5853):1144-1146

Memory processes are modulated by the biological clock, although the mechanisms are unknown. Here, we report that in the diurnal zebrafish both learning and memory formation of an operant conditioning paradigm occur better during the day than during the night. Melatonin treatment during the day mimics the nighttime suppression of memory formation. Training in constant light improves nighttime memory formation while reducing endogenous melatonin concentrations. Treatment with melatonin receptor antagonists at night dramatically improves memory. Pinealectomy also significantly improves nighttime memory formation. We adduce that melatonin is both sufficient and necessary for poor memory formation during the night.  相似文献   

波兰的种子产业     

熊融 《中国种业》2007,(5):23-25

在正式加入欧盟后，波兰的种子产业发生了重大的变化。本文着重介绍了波兰种子产业近年来的发展状况，以及波兰国内一些重要的种子公司。  相似文献   

Cell proliferation and expression of connexins differ in melanotic and amelanotic canine oral melanomas     

Tarso Felipe Teixeira  Luciana Boffoni Gentile  Tereza Cristina da Silva  Gregory Mennecier  Lucas Martins Chaible  Bruno Cogliati  Marco Antonio Leon Roman  Marco Antonio Gioso  Maria Lucia Zaidan Dagli 《Veterinary research communications》2014,38(1):29-38

Melanoma is a malignant neoplasm occurring in several animal species, and is the most frequently found tumor in the oral cavity in dogs. Melanomas are classified into two types: melanotic and amelanotic. Prior research suggests that human amelanotic melanomas are more aggressive than their melanotic counterparts. This study evaluates the behavior of canine melanotic and amelanotic oral cavity melanomas and quantifies cell proliferation and the expression of connexins. Twenty-five melanomas (16 melanotic and 9 amelanotic) were collected from dogs during clinical procedures at the Veterinary Hospital of the School of Veterinary Medicine and Animal Science of the University of São Paulo, Brazil. After diagnosis, dogs were followed until death or euthanasia. Histopathology confirmed the gross melanotic or amelanotic characteristics and tumors were classified according to the WHO. HMB45 or Melan A immunostainings were performed to confirm the diagnosis of amelanotic melanomas. Cell proliferation was quantified both by counting mitotic figures and PCNA positive nuclei. Expressions of connexins 26 and 43 were evaluated by immunohistochemistry, qRT-PCR and Western blot. Dogs bearing amelanotic melanomas presented a shorter lifespan in comparison to those with melanotic melanomas. Cell proliferation was significantly higher in amelanotic melanomas. Expressions of Connexins 26 and 43 were significantly reduced in amelanotic melanomas. The results presented here suggest that oral cavity melanotic and amelanotic melanomas differ regarding their behavior, cell proliferation and connexin expression in dogs, indicating a higher aggressiveness of amelanotic variants.  相似文献   

A Remote Sensing Characterization of the Effects of Anastrepha striata ＆ Anastrepha ludens on Guava Cultures in Mexico     

Eduardo Vazquez  ;Roman Alvarezl 《农业科学与技术》2014,(8):663-678

Detection of the presence of Anastrepha striata and Anastrepha ludens in guava cultures is presently done in Mexico by actually catching the flies in strategically located traps. The objective of this study is to show that it is possible to locate areas with the presence or absence of flies by remote sensing means, thereby simplifying the traditional way of detection of these plagues. In the field, groups of traps were selected where flies had been captured, as well as areas in which there was no capture in the traps. The radiometric signatures of whole trees and leaves were obtained, showing measurable differences between those specimens affected by the plague and those unaffected. Next we selected a SPOT5 image of 2007 corresponding to the study area in Calvillo, State of Aguascalientes, in Mexico, one of the major areas of guava cultures in the country. A supervised classification of the image allowed for the location of guava cultures in it. The guava culture areas obtained from this classification were validated comparing them to available maps of the cultured areas. Spectral signatures for the classes were derived from the image data. The separability of pairs of classes was also evaluated in order to maximize it. The IR/R （infrared to red ratio） ratio of the image bands was evaluated in 80 × 80 pixels around the locations of five traps where flies had been captured, and around five locations where the traps had not captured flies. Only the pixels where guava cultures were present were included in the analysis, other types of vegetation and soil coverage were rejected. We found that the index distributions with flies captured and those without flies captured cluster in two well-separated groups. We note that plotting the whole distribution of pixels around a trap yields a diagnostic view of the area, and individual index values do not provide such a view, since values with the flies＇ presence and without these overlap to some extent. Further analyses of other trap locations confirmed this separation  相似文献   

Waldschäden durch den Gartenschläfer     

Roman Kirschner 《Journal of pest science》1955,28(1):9-9

Ohne Zusammenfassung  相似文献   

波兰种子产业现状介绍     

刘善德 《种子世界》2002,(5):50-51

1概况 波兰位于欧洲中部，总面积31万km2。总人口4000万。播种面积1450万hm2,基中农作物种子生产面积……  相似文献   

A proteome-based assessment of the earthworm Eisenia fetida: response to chemical warfare agents in a sandy loam soil: The 7th international symposium on earthworm ecology · Cardiff · Wales · 2002     

Roman G. Kuperman  Ronald T. Checkai  Lisa M. Ruth  Tammy Henry  Michael Simini  David G. Kimmel  Carlton T. Phillips  Brian P. Bradley 《Pedobiologia》2003,47(5-6):617-621

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Protein resources of wildSecale species     

Dr. Roman Kubiczek  Wiesław Łuczak  Bogusław Molski 《Genetic Resources and Crop Evolution》1981,29(1):159-167

Summary The aim of this study was to find the eventual sources of increased protein content and of the changed balance between exogenic amino acids in caryopses protein of 9 wildSecale species (S. chaldicum Fed.,S. Kuprijanovii Grossh.,S. anatolicum Boiss.,S. montanum Guss.,S. silvestre Host,S. ancestrale Zhuk.,S. afghanicum Vav.,S. dighoricum Vav.,S. segetale Roshev.). A comparison was completed between the previous cited wild species and low and high protein rye cultivars ofS. cereale L. species, from the point of their amino acid composition and the ultrastructure of endosperm proteins. The wild species surpassed the cultivated varieties in protein content, useful protein content, and as much as twice the direct amount of some of the most important, from a nutritional point of view, amino acids, e.g. lysine or methionine. The first limiting amino acids were for wild species isoleucine, threonine and lysine. The wild species with the highest protein content differed significantly from the cultivated species in the amounts of protein matrix surrounding the starch granules in the deeper layers of endosperm cells.

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Proteinressourcen vonSecale-Wildarten

Zusammenfassung Von 9Secale-Wildarten (S. chaldicum Fed.,S. kuprijanovii Grossh.,S. anatolicum Boiss.,S. montanum Guss.,S. silvestre Host,S. ancestrale Zhuk.,S. afghanicum Vav.,S. dighoricum Vav.,S. segetale Roshev.) wurde das Protein der Karyopsen daraufhin untersucht, ob es darunter Sippen mit einem verbesserten Proteingehalt und einem geänderten Verhältnis von exogenen Aminosäuren gibt. Die genannten Wildarten wurden mit proteinreichen und proteinarmen Zuchtsorten vonS. cereale L. hinsichtlich der Aminosäure-Anteile und der Ultrastruktur des Endosperm-Proteins verglichen. Die Wildarten übertrafen die Zuchtsorten im Eiweißgehalt und im 'nutzbaren Eiweißgehalt und enthielten etwa die doppelte Menge der (unter dem Gesichtspunkt der Ernährung) wichtigsten Aminosäuren, wie Lysin und Methionin. Die ersten limitierenden Aminosäuren waren für die Wildarten Isoleucin, Threonin und Lysin. Die Wildarten mit dem höchsten Proteingehalt unterschieden sich signifikant in den Ausmaßen der Proteinmatrix, die die Stärkekörner von tiefer gelegenen Endospermzellen umgibt, von der Kulturart.

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Secale L.

(S. chaldicum Fed., S. kuprijanovi Grossh., S. anatolicum Boiss., S. montanum Guss., S. silvestre Host, S. ancestrale Zhuk., S. afghanicum Vav., S. dighoricum Vav., S. segetale Roshev.) ë . S. cereale L., , , . , , ( ) , . , . , ë .

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Presented as poster

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The authors thank M.Mauszyska and R.Izdebski for propagation of rye materials used in this research.  相似文献