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91.
Albert D. Rovira 《Pest management science》1973,4(3):361-366
The use of 14C-labelling of plants in short-term studies has established that the major zone of release of carbon-containing materials from roots is the zone of elongation. Much of this material is in an insoluble form, comprising sloughed-off root cap cells and polysaccharide material, and remains in the immediate vicinity of the root. Electron microscopy of ultra-thin sections of the root-soil interface of wheat plants has shown that colonisation by micro-organisms of the rhizosphere is relatively sparse in the young parts of roots. In the older parts of roots, evidence was obtained that bacteria lyse the walls of the outer root cells and this is followed by dense colonisation of these moribund outer cells by bacteria. 相似文献
92.
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94.
An 8-year-old, spayed female Domestic Short-haired cat was referred for further evaluation of chronic lymphocytic-plasmacytic stomatitis and bilateral ocular disease. The cat had been treated with systemic glucocorticoids for several months. Initial ophthalmic examination revealed bilateral deep stromal corneal ulcers, exudative panuveitis and secondary glaucoma. Mature mild neutrophilia and monocytosis were detected on complete blood cell count. Abnormalities in the serum profile were hyperglycemia, mild azotemia, hyperglobulinemia and moderate polyclonal gammapathy. Urinalysis revealed glucosuria without ketonuria. Diabetes mellitus was diagnosed and treatment with long-acting insulin was started. An enzyme-linked immunosorbent assay was highly positive for leishmaniasis, and treatment with allopurinol was started. Although specific topical treatment was applied, melting ulcers progressed to corneal perforation and both eyes were enucleated. Ocular histology showed large numbers of intracellular organisms compatible with amastigotes of the genus Leishmania located in the uveal tract, cornea, sclera and retina. Results of inmunohistochemistry staining on ocular samples were positive for Leishmania. Bone marrow cytology demonstrated numerous macrophages with intracytoplasmatic Leishmania. Polymerase chain reaction results on bone marrow for Leishmania were positive. Three weeks later, hypoglycemic episodes permitted withdrawal of the insulin therapy. To the authors' knowledge this is the first case of ocular and visceral leishmaniasis diagnosed in vivo and under systemic treatment in a cat. 相似文献
95.
Regression analysis in the l-alkylsulphonyl-2-arylacetylene series yielded significant correlations of antifungal activity against six microorganisms with certain physicochemical parameters (electronic effects, lipophilicity and steric factors). Fungicidal activity is enhanced by introducing electron-withdrawing substituents in the aryl nucleus, whereas variation of the lipophilic parameter reveals an optimum value. The results obtained indicate a mechanism of action based on a reaction of the compounds with nucleophiles present in the fungal cells, which was confirmed by determining the second-order rate constants of the reaction between 1 -alkylsulphonyl-2-arylacetylenes and the model nucleophile 4-nitro(thiophenol). The lipophilic para-meter was also determined experimentally using thin-layer chromatography. Regression analysis with this completely experimental set of parameters regression gave highly significant results in close agreement with those obtained above. 相似文献
96.
Albert J. Clemmens 《Agricultural Water Management》1982,5(2):159-170
The infiltration characteristics of a soil are important to the design, evaluation and management of border irrigation systems. The use and verification of border irrigation models also rely heavily on infiltration. This paper presents a technique for determining infiltration when detailed information is available on the total infiltrated volume during the irrigation which can be obtained from measurements of inflow, outflow, and water depths on the border strip. The method uses a volume balance at progressive times and is an extension of earlier work. Data from this method were used as input to the zone-inertia border irrigation model and good agreement was found between measured and computed values of advance, recession, runoff rates and volumes, and surface water depths. 相似文献
97.
Sugerman BE Ercolano B Barlow MJ Tielens AG Clayton GC Zijlstra AA Meixner M Speck A Gledhill TM Panagia N Cohen M Gordon KD Meyer M Fabbri J Bowey JE Welch DL Regan MW Kennicutt RC 《Science (New York, N.Y.)》2006,313(5784):196-200
We present late-time optical and mid-infrared observations of the Type II supernova 2003gd in the galaxy NGC 628. Mid-infrared excesses consistent with cooling dust in the ejecta are observed 499 to 678 days after outburst and are accompanied by increasing optical extinction and growing asymmetries in the emission-line profiles. Radiative-transfer models show that up to 0.02 solar masses of dust has formed within the ejecta, beginning as early as 250 days after outburst. These observations show that dust formation in supernova ejecta can be efficient and that massive-star supernovae could have been major dust producers throughout the history of the universe. 相似文献
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99.
Edwige Gaby Nkouaya Mbanjo Fran?ois Tchoumbougnang Albert Sone Mouelle Julius Enyong Oben Moses Nyine Carine Dochez Morag Elizabeth Ferguson James Lorenzen 《Euphytica》2012,188(3):369-386
A well-saturated genetic linkage map is valuable for fundamental and applied genetic research. Genetic linkage maps of two half-sib diploid banana populations were constructed using allele-specific-polymerase chain reactions (AS-PCRs), diversity array technology (DArT), and simple sequence repeat (SSR) markers. Molecular maps were produced for each parent using the pseudo-testcross mapping strategy. The first maternal map (6142-1, 81 individuals) consisted of 231 markers divided as followed: 121 DArT, 106 SSR and 4 AS-PCR markers in 15 linkage groups (LGs) covering 670?cM. The second maternal map (6142-1-S, 58 individuals) contained a total of 152 markers including 71 DArTs, 79 SSRs, and 2 AS-PCRs mapped to 16 LGs that spanned 698?cM. The combined paternal map (139 individuals) comprised 316 markers (196 DArTs, 117 SSRs and 3 AS-PCRs) distributed over 15 LGs with a total map length of 1,004?cM. While distorted segregation of some markers was observed in all maps, this was much more frequent for the male parent. Homology between maps was assessed using common markers. While there was generally good congruity with regard to marker order across maps, incongruity in other cases may reflect chromosomal rearrangement events such as inversions, translocations, or deletions. The new banana map can provide a better understanding of the Musa genome and could be used for the identification of economically important traits and improvement of breeding strategies. 相似文献
100.
Boguslavskiy AE Mikosch J Gijsbertsen A Spanner M Patchkovskii S Gador N Vrakking MJ Stolow A 《Science (New York, N.Y.)》2012,335(6074):1336-1340
Subcycle strong-field ionization (SFI) underlies many emerging spectroscopic probes of atomic or molecular attosecond electronic dynamics. Extending methods such as attosecond high harmonic generation spectroscopy to complex polyatomic molecules requires an understanding of multielectronic excitations, already hinted at by theoretical modeling of experiments on atoms, diatomics, and triatomics. Here, we present a direct method which, independent of theory, experimentally probes the participation of multiple electronic continua in the SFI dynamics of polyatomic molecules. We use saturated (n-butane) and unsaturated (1,3-butadiene) linear hydrocarbons to show how subcycle SFI of polyatomics can be directly resolved into its distinct electronic-continuum channels by above-threshold ionization photoelectron spectroscopy. Our approach makes use of photoelectron-photofragment coincidences, suiting broad classes of polyatomic molecules. 相似文献