58 research outputs found
Controlled method of reducing electrophoretic mobility of macromolecules, particles, or cells
A method of reducing electrophoretic mobility of macromolecules, particles, cells, and other substances is provided which comprises interacting in a conventional electrophoretic separating procedure, the substances with a polymer-linked affinity compound comprised of a hydrophilic neutral polymer such as polyethylene glycol bound to a second component such as a hydrophobic compound, an immunocompound such as an antibody or antibody active fragment, or a ligand such as a hormone, drug, antigen, or a hapten. The reduction of electrophoretic mobility achieved is directly proportional to the concentration of the polymer-linked affinity compound employed, and such reduction can comprise up to 100 percent for particular particles and cells. The present invention is advantageous in that electrophoretic separation can now be achieved for substances whose native surface charge structure had prevented them from being separated by normal electrophoretic means. Depending on the affinity component utilized, separation can be achieved on the basis of the specific/irreversible, specific/reversible, semi-specific/reversible, relatively nonspecific/reversible, or relatively nonspecific/irreversible ligand-substance interactions
Controlled method of reducing electrophoretic mobility of various substances
A method of reducing electrophoretic mobility of macromolecules, particles, cells, and the like is provided. The method comprises interacting the particles or cells with a polymer-linked affinity compound composed of: a hydrophilic neutral polymer such as polyethylene glycol, and an affinity component consisting of a hydrophobic compound such as a fatty acid ester, an immunocompound such as an antibody or active fragment thereof or simular macromolecule, or other ligands. The reduction of electrophoretic mobility achieved is directly proportional to the concentration of the polymer-linked affinity compound employed, and the mobility reduction obtainable is up to 100 percent for particular particles and cells. The present invention is advantageous in that analytical electrophoretic separation can not be achieved for macromolecules, particles, and cells whose native surface charge structure had prevented them from being separated by normal electrophoretic means. Depending on the affinity component utilized, separation can be achieved on the basis of specific/irreversible, specific/reversible, semi-specific/reversible, relatively nonspecific/reversible, or relatively nonspecific/irreversible ligand-substance interactions. The present method is also advantageous in that it can be used in a variety of standard laboratory electrophoresis equipment
Cultural Diversity in the United States and Its Impact on Human Development
Previous studies have yielded mixed results on the impact of cultural diversity on economic performance. We find a positive relationship in the United States between cultural diversity and a comprehensive measure of human development that incorporates health, education, and income. We also disaggregate cultural diversity into three components including ethnicity, language, and religion. We find a positive relationship between human development and both religious and language diversity, and a negative relationship with ethnic diversity. These relationships are robust, using several alternative mathematical measures of diversity. Our results are consistent with diversity generating benefits from exposure to a variety of experiences, ideas, and skills while introducing costs due to difficulty in communication, difference in preferences, and conflict between polarized groups. We conclude that strong institutions are essential to maximize the benefits of diversity while mitigating the associated costs
Music Education Majors vs. Elementary Education Majors: The Relationship Between World Music Preferences and International-Mindedness
Many educators agree that learning world music is beneficial for the development of international-mindedness. The purpose of this study is twofold: 1) to examine whether there is a significant difference in preference and familiarity for world music between music education and elementary education majors, and 2) to find out how international-mindedness is related to preference and/or familiarity to world music. In this cross-sectional survey study pre-service teachers (N=85) provided insights into their familiarity and preference for world music samples with which they may or may not have been familiar. They were also asked to respond to survey items designed to measure international-mindedness. Findings indicate there is a significant difference between music education and elementary education majors’ preference for world music. Music education majors preferred the world music examples to a significantly greater degree than did their elementary education counterparts. Interestingly, there was not a significant difference between groups for familiarity with world music – only with preference for world music. Furthermore, there were significant correlations between preferences and international-mindedness
FNAS phase partitions
Project NAS8-36955 D.O. #100 initially involved the following tasks: (1) evaluation of various coatings' ability to control wall wetting and surface zeta potential expression; (2) testing various methods to mix and control the demixing of phase systems; and (3) videomicroscopic investigation of cell partition. Three complementary areas were identified for modification and extension of the original contract. They were: (1) identification of new supports for column cell partition; (2) electrokinetic detection of protein adsorption; and (3) emulsion studies related to bioseparations
085— Success of Batesian Mimicry in the Ant-Mimicking Spider \u3ci\u3eMyrmarachne formicaria\u3c/i\u3e
Myrmarachne formicaria (Salticidae) is an ant-mimicking spider which arrived in North America fairly recently, first noted in Ohio in 2001. It is important to understand how M. formicaria will impact other species as it spreads throughout North America. The goal of this study was to assess the success of Batesian mimicry used by the ant-mimicking spider in avoiding predation when in a staged encounter with another salticid spider. Myrmarachne formicaria mimic ants in the movement of their forelegs to resemble ant antennae, as well as bob their abdomen. The predator spiders were placed in a small petri dish with either M. formicaria or a non-mimic salticid spider of a different species. M. formicaria was attacked less frequently by the predator compared to the non-mimic (p= 0.045). We scored the frequency of behaviors in the ant-mimics including abdominal bobbing and movement of their enlarged chelicerae. Preliminary analysis of the videos showed that ant-mimics benefit from some of these movements as individuals that were not attacked exhibited a longer duration of chelicerae movement. We found no significant difference in abdomen movement between ant-mimics that were attacked or not. Ant-mimics do seem to benefit from a lower incidence of attack. Further investigation is needed to understand the benefit that Batesian mimicry provides for these spiders
Diversity in the Heartland of America: The Impact on Human Development in Indiana
This article is the third in a series of studies measuring the impact of cultural diversity on human development. We disaggregate cultural diversity into three components: ethnicity, language, and religion. The first study examined the impact of diversity internationally. We found that countries are worse off with greater diversity, especially religious diversity; however, we found that more-prosperous countries with strong institutions benefited from increased diversity. We concluded that strong institutions are essential to maximize the benefits of diversity while mitigating the associated costs. The second study examined the impact of diversity within the United States, where institutional strength was assumed to be relatively great and similar between states. We found an overall negative impact from diversity. Ethnic diversity was negatively associated with human development, while religious and language diversity had a positive impact. We concluded that in the United States, there is more tolerance for religious and language differences compared to ethnic differences. In this third study, we examine the impact of diversity within the state of Indiana. As with our national results, we find a generally negative relationship between human development and diversity. Ethnic diversity has a negative impact, while religious and language diversity are generally positive influences. Strong political and legal institutions may not be sufficient to extract net benefits from diversity if social attitudes that guide behavior are not supportive. The results suggest that net benefits from diversity in Indiana may depend on improvement of social attitudes and in commitment to social services that support historically disadvantaged minority groups
Hardware for studying the demixing of aqueous polymer two-phase systems in low gravity
The gravity-free demixing behavior of aqueous polymer two-phase systems (APTPS) has been studied on Earth, and onboard KC-135 aircraft and the Space Shuttle. Results suggest a good correlation between the demixing behavior of isopycnic systems on Earth and the low g behavior of systems exhibiting phase density differences. The short term (20 s) behavior of APTPS onboard KC-135 aircraft has been shown to mimic their initial demixing behavior in space. It appears that the few minutes of low g provided by parabolic rocket flight will be sufficient to study all but the later stages of demixing of APTPS. We are therefore turning our attention toward the design and use of hardware for studying the demixing of APTPS onboard sounding rockets. This seminar will discuss the evolution of hardware and research from hand-held KC-135 and Shuttle hardware through to automated hardware designed for utilization of KC-135, sounding rocket, and Space Shuttle Mid-deck Locker flight opportunities
Characterization of surfaces
Low gravity biotechnology experiments indicate a need to better understand and control a host of liquid-solid interfacial phenomena which reduce the efficiency of bioseparations methods on earth as well as in space. We have improved and utilized polymeric and silane derivatives, developed in association with MSFC, in order to control such phenomena. The objectives of the proposed research have been obtained. They were to improve NASA-patented coatings capable of controlling macromolecular adsorption, electroosmosis, and particle electrophoresis over a wide range of pH, and to further characterize the ability of polymeric coatings to control wall wetting interactions. To date this research has resulted in six publications and four abstracts. It has also aided researchers at MSFC with studies on the electrophoresis of large DNA molecules in free solution. It will continue to enhance NASA's efforts to exploit the space environment to enhance knowledge of phenomena relevant to biotechnology, and obtain bioseparations currently unobtainable on Earth. Abstracts from the 1994 ACS Meeting in Birmingham are attached
Microgravity sciences application visiting scientist program
Marshall Space Flight Center pursues scientific research in the area of low-gravity effects on materials and processes. To facilitate these Government performed research responsibilities, a number of supplementary research tasks were accomplished by a group of specialized visiting scientists. They participated in work on contemporary research problems with specific objectives related to current or future space flight experiments and defined and established independent programs of research which were based on scientific peer review and the relevance of the defined research to NASA microgravity for implementing a portion of the national program. The programs included research in the following areas: protein crystal growth, X-ray crystallography and computer analysis of protein crystal structure, optimization and analysis of protein crystal growth techniques, and design and testing of flight hardware
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