Mycological and FTIR analysis of biotic foxing on paper substrates

The small rusty stains (foxing) frequently found on historic paper documents, books, and prints have generally been analysed in the past by optical microscope through their morphochromatic appearance under visible light and UV radiation. Despite increased research efforts with more sophisticated techniques (mainly SEM and XRF), the biotic or even chemical origin of these stains remains unclear. The purpose of this paper is to verify to what extent a simple technique such as FTIR-ATR spectroscopy can be utilised for a clearer understanding of the controversial nature of foxing. Since this technique is sensitive to several organic chemical groups that are in common with both fungi and gelatine-sized ancient paper, some modern cardboards stained by biotic foxing have been selected for the analyses. The results clearly show the importance of FTIR and mycological analyses for the identification of residual microfungal agents, together with the by-products of their activity on paper substrates.     

The MADS box genes SEEDSTICK and ARABIDOPSIS Bsister play a maternal role in fertilization and seed development

The haploid generation of flowering plants develops within the sporophytic tissues of the ovule. After fertilization, the maternal seed coat develops in a coordinated manner with formation of the embryo and endosperm. In the arabidopsis bsister (abs) mutant, the endothelium, which is the most inner cell layer of the integuments that surround the haploid embryo sac, does not accumulate proanthocyanidins and the cells have an abnormal morphology. However, fertility is not affected in abs single mutants. SEEDSTICK regulates ovule identity redundantly with SHATTERPROOF 1 (SHP1) and SHP2 while a role in the control of fertility was not reported previously. Here we describe the characterization of the abs stk double mutant. This double mutant develops very few seeds due to both a reduced number of fertilized ovules and seed abortions later during development. Morphological analysis revealed a total absence of endothelium in this double mutant. Additionally, massive starch accumulation was observed in the embryo sac. The phenotype of the abs stk double mutant highlights the importance of the maternal-derived tissues, particularly the endothelium, for the development of the next generation.     

Black box analysis of the skin senses as a multiple communication channel

The skin senses have been investigated as a multichannel parallel information system. In psychophysical experiments using two cold two warmth and two vibration stimuli the capability of these senses have been determined for transmitting independent parallel information. A black box model is used to describe interactions within the system between pairs of signals causing two different response components in a multiple response after multimodal activation. The theory distinguishes two kinds of interaction, those between internal noise sources and between internal signal sources. It appears that the skin senses show only a very small interaction of their respective noise sources whereas their signal sources interact extensively. The repercussions for the skin as a parallel information transmitter is discussed shortly in the context of a development of an optimum skin vision system, which should project an environment onto the skin, employing both the sense of touch and the sense of temperature.     

Mycological aspects of a disease of young perch in Windermere

A disease of young perch in Windermere was investigated. In contrast to the case of U.D.N. infections of salmon and trout, a variety of fungi were obtained from the diseased fish. These reflected the spora present in the water at the same time to a large extent. An exception was Saprolegnia ferax , which did not grow on the fish and indicated that some degree of host specificity was involved. The Achyla isolates, both from the fish and from the water, were found to be heterothallic and male in reaction.     

In Celebration of the Publication of a New Mycological Journal from Jilin,China

The 2 4thvolumeofJOURNALOFJILINAGRICULTURALUNIVERSITYwaspublishedinFebruary 2 0 0 2asmemorialissueofthelateProf.ZHOUZong huangatJilinAgriculturalUniversity .Inthisissueatotalof34myco logicalandphytopathologicalpaperswasreported ,aswellasadetailedintroductiontothescientificcareerandachievementsofProf.ZHOU .ThetopicsandtitlesofthepapersherewellrepresentrecenttrendsandprogressinthesefieldsofstudyinChina .MycologistsinAsiahavebeenconcernedwithmycologicalinformationfromChina .…     

Building a stage for interhelical play in rhodopsin

Biochemical data providing new insights into the packing of helices I and II in the transmembrane domain of rhodopsin reveals the existence of a specific set of size- and charge-sensitive interhelical interactions that influence protein tertiary structure. These findings have broad implications towards understanding the molecular consequences of naturally occurring mutations associated with the retinal degenerative disease autosomal dominant retinitis pigmentosa.     

Mutational analysis of the Escherichia coli DEAD box protein CsdA

The Escherichia coli cold shock protein CsdA is a member of the DEAD box family of ATP-dependent RNA helicases, which share a core of nine conserved motifs. The DEAD (Asp-Glu-Ala-Asp) motif for which this family is named has been demonstrated to be essential for ATP hydrolysis. We show here that CsdA exhibits in vitro ATPase and helicase activities in the presence of short RNA duplexes with either 3' or 5' extensions at 15 degrees C. In contrast to wild-type CsdA, a DQAD variant of CsdA (Glu-157-->Gln) had no detectible helicase or ATPase activity at 15 degrees C in vitro. A plasmid encoding the DQAD variant was also unable to suppress the impaired growth of the csdA null mutant at 15 degrees C. Plasmid-encoded CsdADelta444, which lacks most of the carboxy-terminal extension, enhanced the growth of a csdA null mutant at 25 degrees C but not at 15 degrees C; this truncated protein also has limited in vitro activity at 15 degrees C. These results support the physiological function of CsdA as a DEAD box ATP-dependent RNA helicase at low temperature.