| [blood-brain barrier and chemotherapy of experimental brain tumors (author's transl)]. | | 1979 | 91993 |
| neural changes in calves intranasally inoculated with two strains of infectious bovine rhinotracheitis virus. | | 1979 | 541454 |
| [ischemic toxin and some disorders of cardiac activity]. | | 1975 | 1166691 |
| quantitative and qualitative dna variations in anabaena azollae strasb. living in azolla filiculoides lam. | heterocysts and vegetative cells of the filamentous nitrogen-fixing anabaena azollae isolated from the apex to the basal leaf cavities of azolla filiculoides were examined by epifluorescent microscope after fluorochrome staining. acridine orange (ao), dapi, and chromomycin fluorochromes were used in order to evidence total dna content and respectively, a + t and g + c bases. measurements of fluorescence intensities were made on photographic prints by the automatic image analysis system quantimet ... | 1992 | 1374307 |
| differences in mrna levels in anabaena living freely or in symbiotic association with azolla. | azolla is a small water fern in whose leaf cavities the filamentous nitrogen-fixing cyanobacterium anabaena azollae is symbiotically associated. using cloned genes from anabaena 7120 for glutamine synthetase (gs), ribulose-1,5-bisphosphate (rubp) carboxylase, nitrogenase and the 32-kd protein of photosystem ii, mrna levels of the corresponding genes in the anabaena endosymbiont were studied by northern hybridization. in rna isolated from the endosymbiont there is a 10-fold reduction of gs transc ... | 1986 | 2869943 |
| clostridium difficile, sulphasalazine, and ulcerative colitis. | clostridium difficile has been implicated in the relapse of ulcerative colitis. controversy exists over this role and its relationship to sulphasalazine exposure. sixty two of 77 patients with a documented relapse of ulcerative colitis were investigated for the presence of clostridium difficile, or its toxin, prior to hospitalization. there was a low incidence of detection which was related to antibiotic exposure (2/62). sampling during the treatment period showed that the occurrence of clostrid ... | 1987 | 2897683 |
| effects of intrauterine devices on the surface ultrastructure of human endometrium before and after removal. | the effects of copper-releasing iuds on the endometrial ultrastructure were evaluated in 101 women. endometrial samples were obtained in the secretory phase of the menstrual cycle, both during and after iud use, and were evaluated using both scanning and electron microscopy. the degree and extent of changes to the surface ultrastructure of the endometrium were found to be related to the copper surface area of the iud. regardless of the duration of iud use, by one month after iud removal the endo ... | 1988 | 3252727 |
| oncology nursing society--position paper on hiv-related issues. | | 1988 | 3357840 |
| oncology nursing society--position paper on hiv-related issues. | | 1988 | 3357840 |
| plasma, red blood cell, total blood, and extracellular fluid volumes in healthy horse foals during growth. | during the growth interval encompassing age 2 days through 24 weeks, plasma, rbc, total blood, and extracellular fluid (ecf) volumes were determined in 7 healthy, resting foals. evans blue dye and sodium thiocyanate were used to estimate plasma and ecf volumes, respectively. absolute plasma volume remained stable from 2 days through 2 weeks of age, then increased progressively through 24 weeks of age. after decreasing between 2 days and 2 weeks of age, absolute rbc and total blood volumes progre ... | 1987 | 3434917 |
| leads from the mmwr. trichinosis--maine, alaska. | | 1986 | 3944989 |
| staining mitochondria in saccharomyces cerevisiae. | | 1969 | 4178311 |
| treatment of moloney lymphoma with lethal doses of dimethyl-myleran combined with injections of haemopoietic cells. | | 1969 | 4178590 |
| cotranscription of genes encoding the small and large subunits of ribulose-1,5-bisphosphate carboxylase in the cyanobacterium anabaena 7120. | in the filamentous cyanobacterium anabaena, the gene for the small subunit (rbcs) of ribulose-1,5-bisphosphate carboxylase is linked to and transcribed together with the gene encoding the large subunit (rbcl) of the same enzyme. the two genes are separated by a spacer of 545 base pairs (bp) that does not contain an open reading frame. both genes hybridize with a predominant 3.1-kilobase transcript that initiates 414 bp upstream from the rbcl coding region. the nucleotide sequence 14-8 bp precedi ... | 1984 | 6091125 |
| antigenic similarity among anabaena azollae separated from different species of azolla. | | 1982 | 6186252 |
| characterization of a nitrogen-fixation (nif) gene cluster from anabaena azollae 1a shows that closely related cyanobacteria have highly variable but structured intergenic regions. | the exact identity of cyanobacteria that have been cultured from symbiotic associations with the water fern azolla spp., whether they are required in the symbiotic process, and their relationship to the symbiotic species, is a matter of some debate. we have characterized a 6 kb region containing the nifb operon and the nifh gene from cyanobacterium anabaena azollae 1a, a putative symbiont of azolla caroliniana. five complete open reading frames have been sequenced. all are very highly conserved ... | 1995 | 7496536 |
| dna amplification fingerprinting of the azolla-anabaena symbiosis. | the azolla-anabaena symbiosis has been used for centuries as a nitrogen biofertilizer in rice paddies. genetic improvement of the symbiosis has been limited by the difficulty in identifying azolla-anabaena accessions and anabaena azollae strains. the recently developed technique of dna amplification fingerprinting (daf) was applied to this problem. daf uses single, short, oligonucleotide primers of arbitrary sequence to direct amplification of a characteristic set of dna products by a thermostab ... | 1993 | 8425061 |
| mutational analysis of asp51 of anabaena azollae glutamine synthetase. d51e mutation confers resistance to the active site inhibitors l-methionine-dl-sulfoximine and phosphinothricin. | the role of asp51 in the catalytic activity of glutamine synthetase from the cyanobacterium anabaena azollae has been analyzed. five mutant enzymes, d51s, d51a, d51e, d51n and d51r, were constructed by site-directed mutagenesis and characterized. asp51 appears to participate in the binding of ammonium ion, as affinity for this substrate was affected in all cases, although it varied according to the charge and/or size of the amino-acid residue, decreasing in the order glu > asn > ser > ala. the r ... | 1999 | 10583418 |
| a cyanobacterial recombination study, involving an efficient n2-fixing non-heterocystous partner. | many filamentous cyanobacteria fix atmospheric nitrogen under natural conditions in specialized anaerobic compartments, heterocysts, interspersed between vegetative cells, which provide protection to the o2-sensitive nitrogenase. a few unicellular cyanobacterial strains are also known to fix nitrogen aerobically at a slower rate. filamentous cyanobacteria lacking heterocysts are not known so far to fix nitrogen. we describe the isolation and purification of a non-heterocystous filamentous cyanob ... | 2000 | 11061181 |
| biodiversity of anabaena azollae isolates from different azolla cultures. | the random amplified polymorphic dna (rapd) profile of a. azollae strains isolated from four different azolla cultures was studied by using different primers. the objective of this study was to determine whether polymerase chain reaction (pcr) with different primers could differentiate the isolated a. azollae strains from one another. the primers amplified specific sequences of the isolates and generated fingerprinting pattern characteristic of each isolate. clear polymorphism was noticed among ... | 2000 | 11395965 |
| changes in symbiotic and associative interrelations in a higher plant-bacterial system during space flight. | the miniature cenosis consisting of the water fern azolla with its associated symbiotic nitrogen-fixing cyanobacterium anabaena and the concomitant bacteria was investigated. ecological closure was shown to produce sharp quantitative and qualitative changes in the number and type of concomitant bacteria. changes in the distribution of bacterial types grown on beef-extract broth after space flight were recorded. anabaena azollae underwent the most significant changes under spaceflight conditions. ... | 1983 | 11542458 |
| the pore of the leaf cavity of azolla species: teat cell differentiation and cell wall projections. | the differentiation of the specialized secretory teat cells of the leaf cavity pore of azolla species was investigated at the ultrastructural level with emphasis on their peculiar cell wall projections. the results indicated that the projections are formed as soon as the teat cells complete their differentiation and that their production is principally associated with changes in endoplasmic reticulum profiles. the number of projections increases with the teat cell age and is stimulated under sal ... | 2002 | 11926065 |
| azolla--a model organism for plant genomic studies. | the aquatic ferns of the genus azolla are nitrogen-fixing plants that have great potentials in agricultural production and environmental conservation. azolla in many aspects is qualified to serve as a model organism for genomic studies because of its importance in agriculture, its unique position in plant evolution, its symbiotic relationship with the n2-fixing cyanobacterium, anabaena azollae, and its moderate-sized genome. the goals of this genome project are not only to understand the biology ... | 2003 | 15626330 |
| [the genetic diversity and homology of anabaena azollae and its host plant (azolla) based on rapd analysis]. | symbiotic anabeana azollae and its host plant anabeana-free azolla were isolated from 16 azolla accessions representing different azolla species or geographic origins.dna polymorphic fragments were obtained by simultaneous rapd amplification of both symbiont and host. the upgma clusters of anabeana azollae and its host azolla were established separately based on dice coefficient caculation and a coordinated relationship was shown between anabeana azollae and its azolla host along both individual ... | 2002 | 15901562 |
| characterization and expression of a metallothionein gene in the aquatic fern azolla filiculoides under heavy metal stress. | a cdna encoding a type 2 metallothionein (mt) was isolated from azolla filiculoides, termed azmt2, accession no. af482470. the azmt2 transcript was expressed in sterile a. filiculoides that were free of the cyanobiont anabaena azollae after erythromycin treatment, proving that azmt2 is encoded by the fern genome. azmt2 rna expression was enhanced by the addition of cd(+2), cu(+2), zn(+2) and ni(+2) to the growth medium. the transcript level of azmt2 correlated with the metal content in the plant ... | 2005 | 16133213 |
| azolla filiculoides nitrogenase activity decrease induced by inoculation with chlamydomonas sp. | experiments were conducted to determine the influence of chlamydomonas sp. on nitrogen fixation (c(2)h(2) --> c(2)h(4)) in azolla filiculoides and on the nitrogen fixation and growth of free-living anabaena azollae 2b organisms. inoculation of azolla medium with chlamydomonas sp. was associated with decreased nitrogenase activity in a. filiculoides and with increases in the density of a fungal population identified as acremonium sp. subsequent inoculation of azolla medium with this fungus was al ... | 1986 | 16347211 |
| dna probes show genetic variation in cyanobacterial symbionts of the azolla fern and a closer relationship to free-living nostoc strains than to free-living anabaena strains. | twenty-two isolates of anabaena azollae derived from seven azolla species from various geographic and ecological sources were characterized by dna-dna hybridization. cloned dna fragments derived from the genomic sequences of three different a. azollae isolates were used to detect restriction fragment length polymorphism among all symbiotic anabaenas. dna clones were radiolabeled and hybridized against southern blot transfers of genomic dnas of different isolates of a. azollae digested with restr ... | 1990 | 16348182 |
| a cobalt requirement for symbiotic growth of azolla filiculoides in the absence of combined nitrogen. | cobalt was shown to be essential for the symbiotic growth of azolla filiculoides and anabacna azollac in the absence of fixed nitrogen. addition of 0.01 mug/liter cobalt resulted in large increases in yield, chlorophyll content and nitrogen fixation as compared to control cultures without cobalt. cobalt was not required for the growth of azolla when nitrate nitrogen was supplied. the number of anabaena azollae cells in the fronds of azolla appeared to be decreased by ommission of cobalt from the ... | 1966 | 16656330 |
| the azolla, anabaena azollae relationship: i. initial characterization of the association. | cultures of azolla caroliniana willd. free of the symbiotic blue-green alga, anabaena azollae, were obtained by treatment of azolla fronds with a regimen of antibiotics. these symbiontfree plants can be maintained only on medium containing a combined nitrogen source.morphological aspects of the symbiotic association show the confinement of the anabaena azollae within the leaf cavity of the azolla. procedures were established for the isolation of pure preparations of anabaena azollae and azolla c ... | 1974 | 16658796 |
| the azolla, anabaena azollae relationship: ii. localization of nitrogenase activity as assayed by acetylene reduction. | anaerobic (microaerophilic) acetylene reduction by azolla caroliniana willd. was dependent on light and saturated at approximately 450 foot candles. maximum rates of acetylene reduction were 60 nmoles/mg chlorophyll minute. however, rates of 25 to 30 nmoles/mg chlorophyll minute were more common.the growth of azolla for 35 days with nitrate or urea as a nitrogen source decreased the rate of acetylene reduction approximately 30% compared to controls grown on nitrogen. prolonged growth on nitrate ... | 1974 | 16658797 |
| azolla-anabaena azollae relationship: iv. photosynthetically driven, nitrogenase-catalyzed h(2) production. | the water fern, azolla caroliniana willd., containing the symbiotic, heterocystous blue-green alga, anabaena azollae, has been studied under various growth conditions to characterize its light-dependent production of h(2). the response of h(2) production to n(2) and c(2)h(2) and the absence of a differential effect of m-chlorocarbonyl cyanide phenylhydrazone on h(2) production and c(2)h(2) reduction, coupled with the parallel inhibition of both processes by dcmu imply that the production of h(2) ... | 1976 | 16659630 |
| azolla-anabaena azollae relationship: v. n(2) fixation, acetylene reduction, and h(2) production. | in order to characterize the reactions catalyzed by nitrogenase in the azolla-anabaena association, (15)n(2) fixation, c(2)h(2) reduction, and atp-dependent h(2) production were measured in both the azolla-anabaena complex and in the alga isolated from the complex.the rate of reduction of substrates and of atp-dependent h(2) evolution was determined at various partial pressures of c(2)h(2) and n(2). a pc(2)h(2) of 0.1 atm was nearly optimal for c(2)h(4) production and inhibited h(2) production b ... | 1977 | 16659984 |
| the azolla-anabaena azollae relationship : xi. phycobiliproteins in the action spectrum for nitrogenase-catalyzed acetylene reduction. | visible absorption spectra are presented for the azolla caroliniana willd.-anabaena azollae strass. association and the individual partners. although absorption by the phycobiliproteins of the endophytic cyanobacterium clearly complements the absorption by the fern pigments, their contribution to the absorption spectrum of the association is effectively concealed by the preponderance of the azolla pigments. action spectra for nitrogenase-catalyzed c(2)h(2) reduction in both the azolla-anabaena a ... | 1981 | 16662130 |
| the azolla-anabaena azollae relationship : xii. nitrogenase activity and phycobiliproteins of the endophyte as a function of leaf age and cell type. | nitrogenase activity was measured in leaves along the main stem axes of azolla pinnata r. br. the activity was negligible in leaves of the apical region, rapidly increased to a maximum as leaves matured, and declined in aging leaves. in situ absorption and fluorescence emission spectra were obtained for individual vegetative cells and heterocysts in filaments of the a. pinnata and azolla caroliniana endophytes removed from the cavities of progressively older leaves. these spectra unequivocally d ... | 1986 | 16664736 |
| azolla-anabaena relationship : xiii. fixation of [n]n(2). | the major radioactive products of the fixation of [(13)n]n(2) by azolla caroliniana willd.-anabaena azollae stras. were ammonium, glutamine, and glutamate, plus a small amount of alanine. ammonium accounted for 70 and 32% of the total radioactivity recovered after fixation for 1 and 10 minutes, respectively. the presence of a substantial pool of [(13)n]n(2)-derived (13)nh(4) (+) after longer incubation periods was attributed to the spatial separation between the site of n(2)-fixation (anabaena) ... | 1987 | 16665538 |
| superoxide dismutase in the symbiont anabaena azollae strasb. | superoxide dismutase was investigated in the symbiont anabaena azollae strasb. living in azolla filiculoides lam. in vegetative cells, three isoenzymatic forms of superoxide dismutase, containing manganese, iron, and the hybrid iron-manganese, respectively, were present. hybrid superoxide dismutase, detected for the first time in cyanobacteria, was 7% of the total superoxide dismutase present in vegetative cells. all three superoxide dismutase forms increased in the anabaena vegetative cells obt ... | 1991 | 16668392 |
| stimulation of pigment accumulation in anabaena azollae strains: effect of light intensity and sugars. | the influence of high light intensity on the growth and pigment accumulating ability of anabaena azollae was investigated. a. azollae responded positively to high light intensity (6 klx) and was further evaluated at higher intensities (10 and 15 klx), in the presence of glucose, sucrose and jaggery +/- dcmu. significant enhancement in phycobiliproteins and carotenoids was observed in the sugar supplemented cultures at high light intensities. sds-page profiles of whole cell proteins revealed the ... | 2006 | 16821712 |
| growth and cellular ion content of a salt-sensitive symbiotic system azolla pinnata-anabaena azollae under nacl stress. | salinity, at a concentration of 10 mm nacl affected the growth of azolla pinnata-anabaena azollae association and became lethal at 40 mm. plants exposed up to 30 mm nacl exhibited longer roots than the control, especially during the beginning of incubation. average root number in plants exposed to 10 and 20 mm nacl remained almost the same as in control. a further rise in nacl concentration to 30 mm reduced the root number, and roots shed off at 40 mm nacl. presence of nacl in the nutrient solut ... | 2006 | 16949957 |
| protection against salt toxicity in azolla pinnata-anabaena azollae symbiotic association by using combined-n sources. | protection from salt stress was observed in the terms of yield (fresh and dry weight, chlorophyll and protein) and nitrogenase activity. azollapinnata appeared highly sensitive to 40 mm external nacl stress. fronds of azolla unable to grow beyond a concentration of 30 mm nacl and accordingly death was recorded at 40 mm nacl on the 6th day of incubation. yield was inhibited by various levels of nacl (0, 10, 20 and 30 mm). addition of combined-n to the growth medium protected the association parti ... | 2006 | 17048699 |
| na(+) regulation by combined nitrogen in azolla pinnata-anabaena azollae symbiotic association during salt toxicity. | to study the regulation of na(+) ion by combined-n sources in azolla pinnata-anabaena azollae, na(+) influx, intracellular na(+) and na(+) efflux were investigated in the presence of different n-sources (n(2), nh(4)(+), no(3)(-) and urea) and various nacl concentrations. sodium influx by azolla pinnata fronds was minimum in the presence of no(3)(-). almost identical levels of intracellular sodium, although less than n(2) and nh(4)(+) incubated fronds were observed in the presence of no(3)(-) and ... | 2008 | 17521724 |
| effects of monosulfuron on growth, photosynthesis, and nitrogenase activity of three nitrogen-fixing cyanobacteria. | application of monosulfuron, a new sulfonylurea herbicide, produced a simulative effect on heterocyst formation and nitrogenase activity but an inhibitory effect on photosynthesis, i.e., a lower net photosynthetic rate, fewer photosynthetic pigments, and a smaller fv/fm ratio at increasingly higher monosulfuron concentrations (0.001-10 mg/l) for three nonspecific filamentous nitrogen-fixing cyanobacteria: anabaena azollae, a. flos-aquae, and a. azotica. the decrease in biliprotein of algal cells ... | 2011 | 20437038 |
| nitrous oxide and day-case laparoscopy: effects on nausea, vomiting and return to normal activity. | patients admitted for day-case laparoscopy were assigned randomly to receive nitrous oxide-oxygen or oxygen, with enflurane, during a standard anaesthetic technique. postoperative morbidity, in particular nausea and vomiting, and ability to resume normal activity were assessed over the ensuing 48 h. supplementary administration of propofol during the operative procedure was required significantly more often (p less than 0.05) in the absence of nitrous oxide. there was no significant difference i ... | 2010 | 2967712 |
| description of a food recording electronic device for use in dietary surveys. | a food recording electronic device has been developed for quantitative collection of dietary data in the home for a period of up to 3 weeks. the accumulated information on the weights and types of food, and time of consumption, is transferred to a host computer for calculation of the nutrient composition of the diet. using this method the subject does not have to read the balance or keep a written diary, and the need for coding of records by a dietitian is eliminated. | 2014 | 3957699 |
| structure of 6-(iodomethyl)-2-oxo-2-phenoxy-1,2-oxaphosphorinane. | c11h14io3p, mr = 352.11, monoclinic, p2(1)/n, a = 8.300 (3), b = 14.081 (2), c = 11.326 (4) a, beta = 104.32 (3) degrees, v = 1282.6 (13) a3, z = 4, d chi = 1.823 mg m-3, lambda(mo k alpha) = 0.71073 a, mu = 25.8 cm-1, f(000) = 688, r = 0.035 for 2364 observed reflections. the six-membered ring o(1), p(2), c(3), c(4), c(5), c(6) is in a chair conformation with phenoxy and iodomethyl groups adopting axial and equatorial orientations, respectively. the bond distances and angles are unexceptional. | 2011 | 3271550 |
| laboratory recognition of coronary artery disease (with a review of the surgical treatment). | | 2015 | 4365693 |
| prediction of dental services utilization: a multivariate approach. | | 1998 | 124704 |
| [isotopic study with radiochromium 51 and radioiron 59 of von jaksch-luzet syndrome (anemia with myelemia in rachitic children)]. | | 2016 | 4907175 |
| surgical experience in necrotising enterocolitis: a report of nineteen cases. | the results of operative intervention in 19 neonates with necrotising enterocolitis are reported. there were four deaths (21%) in the series. intestinal perforation was the indication for surgery in 10 cases (55%), three of which did not survive. timing of operative intervention can be optimised only by close liaison between experienced physicians and surgeons in order to avoid intestinal perforation. | 2014 | 4082356 |
| [arteriosclerosis and thrombocyte aggregation]. | | 1999 | 22038 |
| multinomial logit analysis of injury severity in u.s. underground bituminous coal mines, 1975-1982. | relationships among mine and injured miner characteristics and degrees of injury are examined for 91 404 injuries in underground bituminous coal mines in the united states from 1975 through 1982. injury severity varies by the mining system, geographical region, circumstances surrounding the injury, the injured miner's age, whether the miner was using powered equipment, the year in which the injury occurred and the location in the mine where the injury happened. injury severity is not related to ... | 2010 | 2937420 |
| dissociation and reassociation of trichocyst proteins: biochemical and ultrastructural studies. | trichocysts, the crystalline exocytotic organelles in paramecium tetraurelia, are composed of small, acidic proteins existing primarily as disulphide-linked dimers. we have disaggregated trichocyst proteins with heat, simultaneously observing the changes in morphology and protein composition. the tip matrix was most heat-labile; its subunits progressively broke away from the distal end. during this process, breakdown of the cylindrical shaft began. shafts first became flattened and torn lengthwi ... | 2013 | 3667715 |
| antabuse contracts for married alcoholics and their spouses: a method to maintain antabuse ingestion and decrease conflict about drinking. | antabuse is widely used in alcoholism treatment as a deterrent to impulsive drinking when the alcoholic encounters some temporary life crisis or other stressful situation. unfortunately, antabuse therapy often is not effective because the alcoholic discontinues the drug prematurely. marital conflicts and arguments, frequently about past drinking or the likelihood of future drinking, are an important stressor that can lead the newly abstinent alcoholic to relapse. the antabuse contract procedure ... | 2013 | 3735473 |
| [immunological problems in diabetes mellitus]. | | 2015 | 4390846 |
| . . . cause for alarm! | | 1986 | 1075224 |
| disabling chest pain in search of a diagnosis. | | 2011 | 3119627 |
| [examples of paraneoplastic syndromes]. | | 2015 | 4522727 |
| postoperative wound infection. | | 2016 | 5021290 |
| the surgical correction of congenital ureteropelvic junction obstructions in normally rotated kidneys. | | 2016 | 4819371 |
| aquatic plant azolla as the universal feedstock for biofuel production. | the quest for sustainable production of renewable and cheap biofuels has triggered an intensive search for domestication of the next generation of bioenergy crops. aquatic plants which can rapidly colonize wetlands are attracting attention because of their ability to grow in wastewaters and produce large amounts of biomass. representatives of azolla species are some of the fastest growing plants, producing substantial biomass when growing in contaminated water and natural ecosystems. together wi ... | 2016 | 27777623 |
| the aquatic fern azolla as a natural plant-factory for ammonia removal from fish-breeding fresh wastewater. | this study has investigated the potential of an azolla-anabaena symbiosis, a marriage between the cyanobacterium anabaena azollae and the aquatic fern (azolla), to remove ammonia from freshwater fish breeding areas. experiments were carried out under artificial light of 20, 70, and 140 μmol m(-2) s(-1). we investigated three different water temperatures for the growing azolla, ranging from sub-optimal to optimal temperatures (15, 22, and 28 °c). the capability of azolla to remove ammonia from wa ... | 2016 | 26805923 |
| effects of the naturally-occurring contaminant microcystins on the azolla filiculoides-anabaena azollae symbiosis. | harmful algal blooms (habs) contaminate aquatic ecosystems and are responsible for animal poisoning worldwide. we conducted a toxicity test with the aquatic fern and the biofertilizer, azolla filiculoides. the sporophytes were exposed to three concentrations (0.01, 0.1 and 1μgml(-1)) of a microcystin (mc) cyanobacterial crude extract and purified mc-lr. the growth of a. filiculoides decreased only at 1μgml(-1) crude extract concentration while with mc-lr it decreased at all the tested concentrat ... | 2015 | 25890050 |
| response of nitrogen-fixing water fern azolla biofertilization to rice crop. | the water fern azolla harbors nitrogen-fixing cyanobacterium anabaena azollae as symbiont in its dorsal leaves and is known as potent n2 fixer. present investigation was carried out to study the influence of fresh azolla when used as basal incorporation in soil and as dual cropped with rice variety mahsoori separately and together with and without chemical nitrogen fertilizer in pots kept under net house conditions. results showed that use of azolla as basal or dual or basal plus dual influenced ... | 2015 | 28324554 |
| deciphering the factors associated with the colonization of rice plants by cyanobacteria. | cyanobacteria-rice plant interactions were analyzed using a hydroponics experiment. the activity of plant defense and pathogenesis-related enzymes, scanning electron microscopy, growth, nitrogen fixation (measured as ara), and dna fingerprinting assays proved useful in illustrating the nature of associations of cyanobacteria with rice plants. microscopic analyses revealed the presence of short filaments and coiled masses of filaments of cyanobacteria near the epidermis and cortex of roots and sh ... | 2015 | 25515189 |
| classification and phylogeny of the cyanobiont anabaena azollae strasburger: an answered question? | the symbiosis azolla-anabaena azollae, with a worldwide distribution in pantropical and temperate regions, is one of the most studied, because of its potential application as a biofertilizer, especially in rice fields, but also as an animal food and in phytoremediation. the cyanobiont is a filamentous, heterocystic cyanobacterium that inhabits the foliar cavities of the pteridophyte and the indusium on the megasporocarp (female reproductive structure). the classification and phylogeny of the cya ... | 2014 | 24737795 |
| genetic diversity and phylogeny analysis of anabaena azollae based on rflps detected in azolla-anabaena azollae dna complexes using nif gene probes. | the cyanobacterium anabaena has both symbiotic and free-living forms. the genetic diversity of anabaena strains symbiotically associated with the aquatic fern azolla and the evolutionary relationships among these symbionts were evaluated by means of rflp (restriction fragment length polymorphism) experiments. three dna fragments corresponding to nif genes were cloned from the free-living cyanobacterium anabaena pcc 7120 and used as probes. a mixture of azolla, anabaena and bacterial dna was extr ... | 1995 | 24169885 |
| immobilization of anabaena azollae from azolla filiculoides in polyvinyl foam for ammonia production in a photobioreactor system. | anabaena azollae (as-ds), isolated from azolla filiculoides and grown in nitrogen-free medium, was immobilized in 5-mm-cube polyvinyl foam pieces and incorporated into a photobioreactor system for the production of nh3. nh3 was produced continuously and in significant amounts. benlate (methyl-1-butyl-carbamoyl)-2-benzimidazole carbamate at 5 ppm and l-methionine-d,l-sulphoximine at 50 μm stimulated nh3 production continuously for a period of 1 week. | 1994 | 24420887 |
| a novel method to produce anabaena-free azolla by in vitro fertilization of micromanipulated megasporocarps. | in the azolla-anabaena azollae symbiotic system, anabaena akinetes get entrapped between the indusium and the apical cap of the megaspore apparatus during megasporocarp development, thus maintaining the continuity of the cyanobacterial association throughout the life cycle of the fern. the entrapped akinetes serve as the source of inoculum for infecting the new sporophyte when it is emerging from the megaspore apparatus. a procedure to generate anabaena-free azolla was developed by fertilizing t ... | 1988 | 24240262 |
| the effects of immobilization on the biochemical, physiological and morphological features of anabaena azollae. | anabaena azollae, a presumptive isolate from azolla filiculoides, was immobilized in polyurethane foam, hydrophilic polyvinyl foam and alginate. when viewed by low-temperature scanning electron microscopy a thick mucilage layer covered the surface of both cells and matrix; this closely resembles the mode of attachment of the symbiont anabaena in the azolla leaf cavity. the heterocyst frequency of the immobilized a. azollae doubled relative to free-living cells and reached a level of 14-17%. immo ... | 1987 | 24225914 |
| a comparative study of nitrogen fixation by the anabaena-azolla symbiosis and free-living populations of anabaena spp. in lake ngahawa, new zealand. | the symbiotic fern azolla filiculoides var. rubra, which contains a blue-green nitrogen fixing alga anabaena azollae, fixed 164 kg n·ha(-1)·ann(-1) in the littoral zone of a small eutrophic lake. associated planktonic anabaena spp. blooms, dominated by anabaena spiroides, fixed 29.5kg n·ha(-1)·ann(-1). nitrogen fixation in both organisms was not obviously related to ambient dissolved inorganic nitrogen levels. by comparing (15)n-n2 and acetylene reduction techniques, we determined a ratio of 3 m ... | 1979 | 28309884 |