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1.
Z. Bouček 《BioControl》1964,9(1):9-15
Summary The author reviews the European species of the Pteromalid genusCallitula
Spinola and keys them out. All four species develop as parasites, probably all on small Diptera: two species [pyrrhogaster (Walk.) andbicolor
spin.] on Cecidomyids and Chloropids in grass stems, two species are associated withPhragmites communis [C. ferrierei sp. n. andelongatus (Thoms)]. From the latter two one is described as new and in the other (elongatus) the so-far-unknown male is described. *** DIRECT SUPPORT *** A5180147 00002
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2.
Cytochalasin D, an inhibitor of actin polymerization, interferes with ascogonial differentiation in the fertilefluffy mutant ofNeurospora crassa. As the total level of actin and its mRNA remain unchanged, this suggests that it is in its microfilamentous form (F-form)
that actin is stringently required for female differentiation. *** DIRECT SUPPORT *** A00EN042 00011 相似文献
3.
The energy charge ofAzotobacter vinelandii was measured and found to be poised at a value of 0.3. This value was expected in view of the rate of oxygen consumption
observed in these resting cells. Adenine nucleotides and poly-β-hydroxybutyric acid were also determined and the relative
amounts of these were used as a basis for speculation on long term survival ofAzotobacter cysts in soil. *** DIRECT SUPPORT *** A01R4012 00003 相似文献
4.
Epinigericin toxicity towards Tetrahymena pyriformis GL; changes in cell volume and intracellular pH
A study of the toxicity of epinigericin, an antibiotic ionophor, towards the ciliate Tetrahymena pyriformis showed that this molecule stopped cell division, increased cell volume and led to a more basic intracellular pH. The action of epinigericin was probably linked to its function as an ionophor. The ionic selectivity of this molecule is still not known. The raising of the intracellular pH of ciliates by this antibiotic may be linked to its toxic action and its ion-transport mechanism in Tetrahymena. *** DIRECT SUPPORT *** AG903066 00009 相似文献
5.
N. Rashevsky 《Bulletin of mathematical biology》1949,11(1):15-17
When the functionQ in the equation ∇2c +Q(c) = 0 is positive and is of a specified kind, the equation admits of a centrally spherical solution such thatc is positive everywhere, tending to zero at infinity anddc/dr=0 atr=0. Physically this corresponds to a local concentration of the solute in an infinite medium without any membranes present.
This result would indicate the possibility of the formation of spontaneous concentrations and non-uniformities in non-linear
diffusion fields. Possible biological implications are mentioned. *** DIRECT SUPPORT *** A01E2041 00002 相似文献
6.
The HLA class I sequences included in this compilation are taken from publications listed in the papers: Nomenclature for factors of the HLA system, 1991 (Bodmer et al. 1992); Nomenclature for factors of the HLA system, 1990 (Bodmer et al. 1991); and Nomenclature for factors of the HLA system, 1989 (Bodmer et al. 1990). Due to the increased number of sequences we have only included sequences for exons 2, 3, and 4 in this compilation. Where discrepancies have arisen between reported sequences, the original authors have been contacted where possible, and necessary amendments to published sequences have been incorporated into this alignment. Future sequencing may identify errors in this list and we would welcome any evidence that helps to maintain the accuracy of this compilation. In the sequence alignments, identify between nucleotides is indicated by a hyphen (-). An unavailable sequence is indicated by a period (.). Gaps in the sequence are inserted to maintain the alignment between different alleles showing variation in amino acid number. *** DIRECT SUPPORT *** A4903038 00002 相似文献
7.
Effect of nickel and aluminium was studied on aflatoxin and lipid production by two strains ofAspergillus flavus in a sucrose—asparagine—salts medium. Inclusion of aluminium in the medium established an inverse relationship between aflatoxin
and lipid production. At lower concentrations aluminium stimulated aflatoxin production, whereas at higher concentrations
it stimulated total lipid production. Nickel at higher concentrations resulted in an increase in total aflatoxin production.
However, no definite correlation was observed between total aflatoxin and total lipid production when nickel was included
in the medium. *** DIRECT SUPPORT *** A00FP116 00002 相似文献
8.
Mechanically isolated hyphal walls of the oomyceteApodachlyella completa (Humphrey) Indoh. (Leptomitales) were investigated by means of biochemical, cytochemical, and X-ray analyses. Microscopic
examination of the cell wall preparations revealed them to be free of cytoplasmic contaminants β-Glucans account for 88% of
wall weight and contain predominantly I→3 and I→6 linkages. Cellulose was demonstrated cytochemically and by X-ray diffraction
and accounts for approximately 6% of wall dry weight. Additionally, walls contain 5% insoluble hexosamine, 4.8% protein, 1.1%
lipid, and 0.5% ash. Chitin was qualitatively detected by means of cytochemical and X-ray analysis. The cell wall composition
ofA. completa is similar to that reported for other oomycetes, in that β-glucans are the primary wall constituents. However, this fungus
shows the unusual feature of chitin occurring simultaneously with cellulose, as do the closely related speciesApodachlya sp. andLeptomitus lacteus. *** DIRECT SUPPORT *** A01R4022 00007 相似文献
9.
ITS regions (internal transcribed spacers—ITS1 andITS2—with the 5.8S gene of the nuclear rDNA) of 25 fruit body samples ofTerfezia terfezioides, originating from Hungary and Italy, were compared. The amplification and sequencing of the ITS region was successful with
both theITS1-ITS4 andITSIF-ITS4 primer pairs. No differences of the restriction fragment length polymorphism profiles were detected among 19 samples collected
in one place at the same time. The sequences of the ITS region of 9 samples collected in different localities were highly
invariable, differing in only two bases. Thus the intraspecific homogeneity of the ITS region seems to be an important species-specific
characteristic ofT. terfezioides in contrast to otherTerfezia species. As the samples of the species were collected from different and distant localities of Europe, the ITS sequence ofT. terfezioides can be considered a very conservative, reliable molecular marker of the fungus. *** DIRECT SUPPORT *** A00EN076 00008 相似文献
10.
A membrane filter direct count method was devised for enumeratingBdellovibrio cells in “clean” suspensions. The procedure involves filtering a specified volume of a diluted, Trisbuffered suspension ofBdellovibrio cells through a known area of a 100-nm-pore-size Millipore brand membrane filter. A clarification solvent was used to render
the filter transparent, so that the bdeloyvibrios on the filter could be photomicrographed and counted either visually or
by means of a Quantimet 720 Image Analyzing Computer. The number ofBdellovibrio cells per milliliter in the undituted suspension could be calculated from the mean number of cells per unit area of the filter,
the dilution factor, and the volume of diluted suspension filtered. TheBdellovibrio cells were distributed on the filters in a Poisson manner when there were not more than about 3.5 cells per 100 μm2 of filter surface. The membrane filter direct counts correlated well with direct counts obtained by the Petroff-Hausser method.
The correlation of direct counts with plaque (“viable”) counts showed that 80 to 95% of the direct-countedBdellovibrio cells in the clean suspensions were capable of forming plaques on lawns of suitable substrate bacteria. *** DIRECT SUPPORT
*** A01R4002 00007 相似文献
11.
Michael Nee 《Brittonia》1982,34(1):85-88
Solanum citrinum from northeastern Mexico is described, figured and discussed. *** DIRECT SUPPORT *** A01CT119 00006 相似文献
12.
Jiří Soják 《Folia Geobotanica》1971,6(2):217-219
Einige alpine, balkanische, mediterrane und kaukasische Arten der GattungHieracium werden in die GattungPilosella versetzt. Es werden 60 neue nomenklatorische Kombinationen vorgeschlagen. *** DIRECT SUPPORT *** A01DO021 00005 相似文献
13.
Marshall D. Sundberg 《American journal of botany》1982,69(10):1707-1709
Petal-stamen initiation was examined in nine species of Cyclamen. The pattern observed in all species is similar to that previously described in the commercial hybrid C. persicum ‘***F-1 Rosemunde Rose‘: Stamens arise as adaxial outgrowths of common petal-stamen primordia. This pattern differs from the characteristic “Primulaceous type” described in the literature. The correlation between the pattern of petal-stamen initiation and phylogenetic specialization within the Primulales is discussed. 相似文献
14.
In previous paper, Saccharomyces cerevisiae LBG H620 and DAM 2155 were compared regarding their ability to float. LBG H620 did not float at all; cells' surface properties indicated that the yeast LBG H620 has a high surface hydrophilicity and a high electrokinetic potential; yeast DSM 2155 possesses high hydrophobicity and a low electrokinetic potential [Tybussek et al. (1994) J Appl Microbiol Biotechnol 41:13–22]. In the present paper, the morphologies of these two yeast strains are compared. Strain LBG H620 formed only single or dudding cells, strain DSM 2155 formed cell aggregates, their size depending on the cultivation condiotions: in the presence of adequate substrate concentration cell aggregates were formed, and during substrate limitation single cell dominated. During rerspiratory growth rather small spherical aggregates and during respiratory/fermentative growth long-strain aggregates were observed *** DIRECT SUPPORT *** AG903053 00004 相似文献
15.
A standardized disk susceptibility test was evaluated by comparing results with minimal inhibitory concentrations obtained
with agar dilution methods. The agar overlay method was used to test 152 Gram-negative bacilli against eight different antimicrobial
agents. One to 3% of the isolates were resistant to an antimicrobic by the MIC method, but appeared to be susceptible by the
disk method. Most very major discrepancies involved disk tests withProteus sp., a microorganism notoriously difficult to test reproducibly.Serratia sp. vs. the polymyxins andKlebsiella sp. vs. nitrofurantoin accounted for most other major discrepancies. With other microorganism-drug combinations, the disk
test was a reasonably accurate technique for classifying bacteria into resistant or susceptible categories. Gentamicin disk
tests were unsatisfactory, but when an intermediate zone category of 13–16 mm was applied, the false susceptible test results
were reduced to 2.6%. Intermediate zone sizes were obtained with 6% of the disk tests; most of those isolates were resistant
or susceptible but not intermediate in susceptibility. About 11% of the strains had intermediate MICs (5–20% with different
drugs), but most of those strains were fully susceptible by the disk technique. *** DIRECT SUPPORT *** A01R4011 00007 相似文献
16.
Biocontrol of fungal root rot diseases of crop plants by the use of rhizobia and bradyrhizobia 总被引:1,自引:0,他引:1
Twenty-oneRhizobium andBradyrhizobium strains were testedin vitro against the mycelial growth of three pathogenic fungi on solid and liquid media. All tested rhizobia and bradyrhizobia significantly
suppressed the growth of the three soil-borne root-infecting fungi (Fusarium solani, Macrophominia phasolina andRhizoctonia solani) either in the absence or presence of iron. This indicates that the siderophore played a minor role in the biocontrol potential
ofRhizobium andBradyrhizobium against pathogenic fungi. Pot experiments revealed that the numbers of propagules causing disease after 4 weeks of planting
varied with species and host plant. The three most activeRhizobium andBradyrhizobium strains (R. leguminosarum bv.phaseoli TAL 182,B. japonicum TAL 377 andBradyrhizobium sp. (lupin) WPBS 3211 D) tested under greenhouse conditions for their ability to protect one leguminous (soybean) and two
non-leguminous (sunflower and okra) seedlings from root rot caused byFusarium solani, Macrophominia phaseolina andRhizoctonia solani provided significant suppression of disease severity compared with nonbacterized control in both leguminous and non-leguminous
seedlings.Bradyrhizobium sp. (lupin) WPBS 3211 D provided the lowest degree of resistance against all the tested pathogens with all host plants. ***
DIRECT SUPPORT *** A00EN058 00013 相似文献
17.
Microbial sensor for selective determination of sulphide 总被引:2,自引:0,他引:2
H. Kurosawa T. Hirano K. Nakamura Y. Amano 《Applied microbiology and biotechnology》1994,41(5):556-559
A microbial sensor consisting of immobilized Thiobacillus thiooxidans, a gas-permeable membrane, and an O2 electrode was prepared for the determination of sulphide. When a sample solution containing sulphide was passed into the flow cell, the output of the microbial sensor decreased markedly with time until a steady state was reached. The total time required for an assay was 20–30 min by the steady-state method. In the pulse method, the total time required for an assay was about 5 min. A linear relationship was obtained between the sensor output and the concentration of sodium sulphide below 0.40 mm. The minimum detectable concentration of sodium sulphide was 0.02 mm. Selectivity of the sensor was satisfactory. The microbial sensor was applied to the determination of sulphide in spring water. A good agreement was obtained between the microbial sensor and the methylene blue method. The regression coefficient was 0.97 for five experiments. The activity of the microbial membrane was stable for more than 25 days. The response was reproducible with 2.5% of the relative standard deviation when a sample solution containing 0.2 mm sodium sulphide was employed. *** DIRECT SUPPORT *** AG903053 00005 相似文献
18.
Barbara Ertter 《Brittonia》1988,40(4):398-399
A new variety,Ivesia aperta var.canina, is described from Dog Valley, Sierra County, Nevada. It differs from the typical variety and approachesI. sericoleuca in its larger, paler yellow petals; longer filaments and styles; and decumbent-ascending vs ascending-erect stems. *** DIRECT SUPPORT *** A01CT146 00004 相似文献
19.
Bacillus subtilis strain 316 M was found to produce extracellular alkaline serine proteinase and lectin. The characteristics of proteinase and lectin accumulation during the growth of the producer organism were found to be similar. The maxima of proteolytic and lectin activities were close and observed at 16 h and 14 h of B. subtilis 316 M batch cultivation, respectively. Alkaline serine proteinase was purified by ion exchange chromatography directly from the culture fluid. Proteinase (eluate) purified 40-fold possessed 60–90 units/ml of caseinolytic activity and 240–320 units/ml of elastolytic activity. Eluate obtained after enzyme sorption on the ion exchanger was used for lectin isolation followed by ammonium sulphate precipiration. Lectin purified 12.3-fold was shown to have a high carbohydrate specificity to N-glycolylneuraminic, N-acetylneuraminic, N-acetylmuramic and d-galacturonic acids with minimal inhibiting concentrations of 2.5–7.5 mm. *** DIRECT SUPPORT *** AG903053 00002 相似文献
20.
The sea anemoneCereus pedunculatus was artificially UV-irradiated to test the effect of UV-light on the number of endosymbiotic dinoflagellates in its gastrodermis
and on their ultrastructure. Anemones were kept in the laboratory in a light: dark cycle (LD 12∶12; 13 W m−2) at 18 °C and briefly (2, 5 and 9 d) exposed to UV radiation at quasisolar intensities, 0.5 or 1 W m−2. Their tentacles were then examined in the electron microscope for qualitative and quantitative changes in the zooxanthellae.
There was an intensity-dependent decrease in the number of symbionts, which in some cases were lost altogether (bleaching).
Irradiated anemones contained a larger proportion of symbionts with ultrastructural abnormalities, namely diminished starch,
some mitochondria with altered matrix and, in particular, characteristic changes in the chloroplasts; instead of being densely
stacked, the thylakoids were spread apart and swollen at the ends of their membranes to form vesicle-like structures. Relatively
large vesicles also appeared in the cytoplasm. The resulting enlargement of the whole dinoflagellate cell was documented morphometrically.
Another intensity-dependent effect was a significant decrease in mitosis rate, established by counting dividing symbiont cells
in TEM micrographs. *** DIRECT SUPPORT *** A03B6037 00006 相似文献