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Tissue cultures find increasingly widespread applications for cloning of many plants. Commercial propagation by tissue cultures is limited to ornamental plants, because the cost of skilled labor required cannot compete with conventional propagation methods. To cut down the cost, some automation is essential. A cost-effective approach is to chop the plantlets into segments on a conveying production line while using machine vision for identifying and locating the number and positions of propagation organs in images of the plantlet segments. Plantlet segments without propagation organs will be rejected, while segments with viable buds will be selected for subculturing. To this end, a machine-vision-controlled automatic subculturing system for potato tissue cultures is proposed as a simpler and more cost-effective solution than the popular trend of imitating the manual sub-culturing task by a robot. A simple and relatively fast image-processing algorithm particularly suitable for classification of potato tissue cultures, was developed. In lieu of the general Medial Axis Transform approach, this specialized algorithm takes advantage of the inherent difference between the geometrical shape and gray scale levels of the stems and the leaves as well as of the rather simple connectivity rules of attachment between them. The results indicate that machine inspection and classification of tissue culture plantlets is possible, but considerably more work needs to be done before this technique is fully developed for automating tissue culture processes. 相似文献
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Chronemic research explores the involvement of time-related messages in communication, and has shown that time is an important component of the message in both traditional and online communication. Social information processing (SIP) theory posits that online communicators exchange social information through chronemic cues. This study points to a gap in SIP theory research, and proceeds to close the gap by demonstrating that changes in socially important attributes are reflected in measurable chronemic changes. A two-person social dilemma online game is used to demonstrate that changes in a simple chronemic variable, interpost pause, reflect differences in the players’ personality (level of extraversion), as well as differences in trust within the dyad. These findings support SIP theory by showing how online chronemics provide cues to important personal and situational information. 相似文献
76.
Douglas S Kalman Samantha Feldman Robert Feldman Howard I Schwartz Diane R Krieger Robert Garrison 《Nutrition journal》2008,7(1):11
Background
Recent research has established correlations between stress, anxiety, insomnia and excess body weight and these correlations have significant implications for health. This study measured the effects of a proprietary blend of extracts of Magnolia officinalis and Phellodendron amurense (Relora®) on anxiety, stress and sleep in healthy premenopausal women.Methods
This randomized, parallel, placebo controlled clinical study was conducted with healthy, overweight (BMI 25 to 34.9), premenopausal female adults, between the ages of 20 and 50 years, who typically eat more in response to stressful situations and scores above the national mean for women on self-reporting anxiety. The intervention was Relora (250 mg capsules) or identical placebo 3 times daily for 6 weeks. Anxiety as measured by the Spielberger STATE-TRAIT questionnaires, salivary amylase and cortisol levels, Likert Scales/Visual Analog Scores for sleep quality and latency, appetite, and clinical markers of safety. The study was conducted by Miami Research Associates, a clinical research organization in Miami, FL.Results
The intent-to-treat population consisted of 40 subjects with 26 participants completing the study. There were no significant adverse events. Relora was effective, in comparison to placebo, in reducing temporary, transitory anxiety as measured by the Spielberger STATE anxiety questionnaire. It was not effective in reducing long-standing feelings of anxiety or depression as measured using the Spielberger TRAIT questionnaire. Other assessments conducted in this study including salivary cortisol and amylase levels, appetite, body morphology and sleep quality/latency were not significantly changed by Relora in comparison to placebo.Conclusion
This pilot study indicates that Relora may offer some relief for premenopausal women experiencing mild transitory anxiety. There were no safety concerns or significant adverse events observed in this study.77.
The bacterial population in an H2-dependent denitrification system was studied. The laboratory set-up was designed for the treatment of potable water and consisted of an electrochemical cell, where the water to be treated was enriched with H2 prior to entering a bioreactor. Bioreactors (columns packed with granulated active carbon) were inoculated with denitrifying bacterial strains isolated from a previous reactor, then sampled immediately after inoculation, or after 1 or 3 months of continuous operation. Total number of the bacteria and numbers of each different strain were determined at various levels of the bioreactor. The strains present in the inoculum were identified as Ochrobactrum anthropi, Pseudomonas stutzeri, Paracoccus panthotrophus and Paracoccus denitrificans. Numbers of the latter declined markedly with time with the other three strains being responsible for nitrate removal. A correlation was found between the relative abundance of each strain and its specific denitrification activity. 相似文献
78.
The heat transfer between a vertical pipe wall and turbulent gas-particle flow is numerically investigated according to the Eulerian-Lagrangian approach and the k-ε turbulence model. The particles are introduced homogeneously into the simulation volume by a unique technique referred to as an artificial feeding volume. The numerical code using additional computer programs is validated with available experimental results for the constant heat flux boundary condition. An average deviation of about 4% and a maximum deviation of about 7% were attained from the numerical predictions for various particle and pipe diameters. The effect of the geometrical parameters and the flow parameters on the gas/particle temperature, the convection heat transfer coefficient between the wall and the gas-particle mixture, and the thermal entry length were studied. An increase in particle diameter (loading ratio ≈ 0.5) extended the thermal entry length and decreased the bulk mixed temperature, particle temperature, and convection heat transfer coefficient. Increasing the pipe diameter led to a significant reduction in bulk mixed temperature and thermal entry length, in addition to a decrease in particle temperature and Nusselt number. Increasing the loading ratio up to 2.36 led to a reduction in wall temperature and bulk mixed temperature, in addition to an increase in the convective heat transfer coefficient and thermal entry length. 相似文献
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80.