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1.
Mende S Krzyzanowski L Weber J Jaros D Rohm H 《Journal of Bioscience and Bioengineering》2012,113(2):185-191
Some Lactobacillus delbrueckii ssp. bulgaricus strains are able to synthesize exopolysaccharides (EPS) and are therefore highly important for the dairy industry as starter cultures. The aim of this study was to investigate the nutritional requirements for growth and EPS production of Lactobacillus delbrueckii ssp. bulgaricus DSM 20081. A medium was developed from a semi-defined medium (SDM) in which glucose was replaced by lactose and different combinations of supplements (nucleobases, vitamins, salts, sodium formate and orotic acid) were added. Constant pH batch fermentation with the modified medium resulted in an EPS yield of approximately 210 mg glucose equivalents per liter medium. This was a 10-fold increase over flask cultivation of this strain in SDM. Although not affecting cell growth, the mixture of salts enhanced the EPS synthesis. Whereas EPS production was approximately 12 mg/g dry biomass without salt supplementation, a significantly higher yield (approximately 20 mg/g dry biomass) was observed after adding the salt mixture. In continuous fermentation, a maximal EPS concentration was obtained at a dilution rate of 0.31/h (80 mg EPS/L), which corresponded to a specific EPS production of 49 mg/g dry biomass. 相似文献
2.
Charles R. Krause Richard C. Derksen Leona E. Horst Heping Zhu Randall Zondag 《Scanning》2009,31(1):24-27
Foliar diseases like apple scab result in significant economic losses to growers each year. Assessment in past studies involved only macroscopic disease ratings. More complete knowledge of the fate and behavior of fungicide has been needed to reduce pesticide use with less off‐target contamination. Field studies were conducted in a production nursery for over 4 years. A moderately susceptible cultivar of ornamental crabapple, Malus spp. cv “Candied Apple”, was sprayed with a fungicide using two sprayer/nozzle configurations. The fungicide used in this study was Mankocide, combination of Cu(OH)2 and mancozeb that permitted electron beam analysis (EBA) identification based on the presence of Cu, MN and Zn in the molecule and formulation. EBA was conducted using a cold field emission scanning electron microscopy and energy dispersive x‐ray microanalyzer. Fresh leaf samples were placed on sticky stubs after each fungicide treatment. The presence or absence of fungal conidia and fungicide residue were measured. EBA permitted direct visualization and identification of the pathogens, morphologically, and chemical characterization of fungicide present. EBA was useful to quantify disease control related to fungicide coverage, sprayer configuration and treatment efficacy. SCANNING 31: 24–27, 2009. Published 2009 by Wiley Periodicals, Inc. 相似文献
3.
Willott James F.; Tanner Lisa; O'Steen Jennifer; Johnson Kenneth R.; Bogue Molly A.; Gagnon Leona 《Canadian Metallurgical Quarterly》2003,117(4):716
A high-throughput phenotype screening protocol was used to measure the acoustic startle response (ASR) and prepulse inhibition (PPI) in mice. ASRs were evoked by noise bursts; prepulses for PPI were 70 dB sound pressure level tones of 4, 12, and 20 kHz. Forty inbred strains of mice were tested (in most cases using 10 males and 10 females of each strain). The data on both the ASR and PPI had high internal and test-retest reliability and showed large differences among inbred strains, indicative of strong genetic influences. Previously obtained measures of hearing sensitivity in the same inbred strains were not significantly correlated with ASR or PPI measures. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
4.
The temperature dependence of the critical current density at high temperatures and in weak applied magnetic field for YBa2Cu3O7–y
ceramic samples with a pronounced granular character is analyzed. The experimental results can be explained in terms of thermally activated motion of the intergrain Josephson vortices at grain boundaries, which may be an indication that the actual limiting factor for the critical current density in ceramic samples results from a weak pinning force density for the intergrain vortices rather than from the weak-link quenching. 相似文献
5.
Reviews and analyzes the literature concerning deinstitutionalization and women and highlights specific ways in which a major public policy initiative has affected the lives of both chronically mentally ill women and women who have been charged with the responsibility of caring for the chronically mentally ill. Special effects of deinstitutionalization on mentally ill women are evident in such areas as sexual exploitation and violence, homelessness, diversion into the criminal justice system, and stigmatization. A group of studies points to special circumstances pertaining to sexual behavior and reproductive control in a deinstitutionalized female population. It is suggested that the expectations of women's behavior based on societal role definitions have affected service planning for this population and that the use of such criteria for program planning runs the risk of injuring patients of both sexes. The need for more conceptual work and research on deinstitutionalization is stressed; however, because deinstitutionalization is an exceedingly complex phenomenon, the importance of remaining sensitive to the wide variety of circumstances that contribute to its outcomes is emphasized. (72 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
6.
In this study of the development of scientific reasoning, 10 5th–6th-grade children ( 5 boys and 5 girls) and 10 noncollege adults conducted experiments over 6 half-hour sessions to explore the causal structure of 2 physical science domains. Feedback in these systems, though relevant to discriminating among hypotheses, was noisy as a result of varying effect sizes and measurement error. After 2 hr on each task, both age groups demonstrated changes in their understanding of the content and in their strategies for generating and interpreting evidence. In general, the adults outperformed the children. Neither valid strategies nor correct beliefs alone was sufficient to guarantee success, suggesting that regarding experimentation either as domain-general induction or as domain-specific learning may oversimplify its complexity. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
7.
Discusses articles by D. E. Polkinghorne (see record 1985-07630-001), G. S. Howard (see record 1985-07626-001), and M. J. Patton (see record 1985-07629-001), who recommended that counseling research be reoriented. The accepted definition of science, based primarily on the work of pre-20th-century physical scientists, does not fit in with the current advanced thinking about the philosophy of science. Similarities and differences in the 3 articles are considered, and problems that arise from the inadequacy of available psychometric and statistical techniques for the new kinds of research envisaged are discussed. It is concluded that the rethinking of some assumptions with regard to determinism and the way counseling is defined are necessary. (4 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
8.
Williams Tannis M.; Fryer Margaret L.; Aiken Leona S. 《Canadian Metallurgical Quarterly》1977,13(6):577
Studied the use of prototypes and distinctive features in visual pattern classification with 12 Ss at each of 3 age levels: 4, 5, and 6 yrs. All Ss attended day-care centers in middle-class neighborhoods of metropolitan Canadian areas. Two tasks were performed: (a) an oddity task requiring selection of the odd pattern in problems containing 2 patterns generated from 1 prototype and 1 from another, and (b) a sequential task requiring designation from memory of each pattern's class membership. There was a marked improvement in oddity task classification accuracy between the 4- and 5-yr age levels. Performance at each age level could be predicted from measures of deviation from prototype and 2 distinctive features unrelated to pattern class membership. In the more difficult sequential task, the preschoolers did not respond to an entire set of features as subsumed in prototype measures, but a single class-defining feature significantly predicted the classifications of the 4- and 5-yr-olds. It is concluded that the ability to use single features develops prior to the ability to use a feature list or prototype and that both distinctive features and prototypes are important for perceptual learning and development. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
9.
A workable psychology of individuality is "one that would generate good research ideas, which, in turn, would lead to steady increases in dependable knowledge." Individual uniqueness "is described primarily in terms of choice and organization, and I consider it the task of psychologists to make those concepts workable—to bring them into the general stream of thinking in research, assessment, and practical activities." Tyler stresses "the significance of concepts of choice and organization in an inclusive psychology of the development of the human individual… . At each stage of our lives, we impose limits on the next stage, by the choices we make and the ways in which we organize what we have experienced." (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
10.
Annovazzi-Lodi V. Donati S. Merlo S. Leona A. 《Lightwave Technology, Journal of》1995,13(12):2349-2353
With a figure-of-eight winding of monomode fiber, we have been able to build multiturn (>100) coils which can be easily trimmed to match the condition of exactly one wavelength-per-turn birefringence. As an example, we report a 45° Faraday rotator intended for an all-fiber optical isolator at λ=1300 nm 相似文献