Ultrasonic evaluation of oxidation and reduction effects on the elastic behavior and global microstructure of YBa2Cu3O7-x

Ultrasonic velocity measurement techniques were used to evaluate the effects of oxidation and reduction on the elastic properties, global microstructure and oxygen content of the YBa2Cu3O(7-x) ceramic superconductor for samples ranging from 70 to 90 pct. of theoretical density. Bulk density, velocity, and elastic modulus generally increased with increasing oxygen content upon oxidation, and this behavior was reversible. Velocity image patterns were similar after oxidation and reduction treatments for a 90 pct. dense sample, although the velocity value at any given point on the sample was changed following the treatments. The unchanging pattern correlated with destructive measurements showing that the spatial pore distribution (fraction and size) was not measurably altered after the treatments. Changes in superconducting behavior, crystal structure, and grain structure were observed consistent with changes in oxygen content

Use of a ‘molecular tug’ to overcome limitations in the production of ‘difficult to express’ recombinant proteins

In recent years there has been an increased drive towards the production of recombinant proteins in large amounts using rapid cell culture processes. Mammalian expression systems such as Chinese Hamster Ovary (CHO) cells have remained the preferred choice for large-scale recombinant protein production (Walsh, 2014). However, in mammalian cells certain recombinant targets can prove to be ‘difficult to express’ and require extensive upstream process optimisation which can have a negative impact on industrial processes. This study has investigated the molecular mechanisms that are responsible for poor recombinant protein production. Model proteins from the Tissue Inhibitors of Metalloproteinase (TIMP) family, TIMP-2, TIMP-3 and TIMP-4, were subject to detailed study to characterise the molecular mechanisms that limit production of recombinant proteins with high sequence homology (Hussain et al., 2017). TIMP-2, -3 and -4, share significant sequence/structural homology (Douglas et al., 1997, Garcia et al., 2012), but show differences when produced in a transient CHO expression system (Hussain et al., 2017) . A systematic screen of the protein expression pathway showed all three TIMPs were detectable at the mRNA and protein level within the cell but only TIMP-2 was secreted in significant amounts into the culture medium. Analysis of the intracellular protein suggested the post-translational processing of poorly expressed TIMPs was limiting. A protein engineering approach was employed to overcome challenges in the production of these ‘difficult to express’ TIMP proteins. This approach involved the attachment of a furin-cleavable pro-sequence from a secretory growth factor to recombinant targets. The pro-sequence was predicted to act as a ‘molecular tug’ to aid transit through the protein expression pathway and/or promote correct post-translational processing. Initially, the furin-cleavable pro-sequence was added to TIMP-3 (non-secreted), which resulted in secretion of TIMP-3, however incomplete processing of the pro-sequence was observed. The protein engineering approach was optimised further and applied in combination with cell engineering (furin overexpression) to TIMP-4 (poorly secreted), which was also successfully detected in significantly higher amounts in the culture medium (Hussain et al., 2017). Together, the described protein engineering approach presents a novel strategy to increase the production of ‘difficult-to-express’ recombinant targets. References: Douglas, D. A., Shi, Y. E. & Sang, Q. X. A. 1997. Computational sequence analysis of the tissue inhibitor of metalloproteinase family. Journal of Protein Chemistry, 16, 237-255. Garcia, M. P. S., Suarez-Penaranda, J. M., Gayoso-Diz, P., Barros-Angueira, F., Gandara-Rey, J. M. & Garcia-Garcia, A. 2012. Tissue inhibitor of metalloproteinases in oral squamous cell carcinomas - A therapeutic target? Cancer Letters, 323, 11-19. Hussain, H., Fisher, D. I., Abbott, W. M., Roth, R. G. & Dickson, A. J. 2017. Use of a protein engineering strategy to overcome limitations in the production of Difficult to Express recombinant proteins. Biotechnology and Bioengineering, 114, 2348-2359. Walsh, G. 2014. Biopharmaceutical benchmarks 2014. Nature Biotechnology, 32, 992-1000

Socialist Dandies International: East Europe, 1946-1959

This article maps the looks and lifestyle choices of small groups of young, like-minded people who emerged in the postwar Soviet Union and East Europe in the background of huge political, social, and cultural changes. With their androgynous bodies wrapped in drape jackets and narrow trousers, and their love of jazz and swing, these young men stood in a sharp contrast to the official ideology that promoted socialism as a new, pure, and highly rationalized project, its ideal robust and strong man, and its mass culture that insisted on educational and restrained forms of entertainment. Through the categories of dress, body, and big city, the article investigates the clashes, and the eventual truce, between the socialist streamlined and rationalized master narrative and the young dandies' fragmented and disordered narrative. The article argues that the socialist dandies were not politically minded, and that their challenge to the officially proclaimed values was informed by their adolescent recklessness and a general postwar desolation. They were declared state enemies because the socialist regimes did not allow for alternative types of modernity. Consequently, the authorities condemned the young dandies' looks and interests as cosmopolitan, because they originated in the West, and as artificial, since they belonged to the culture that had preceded a new socialist world

Dealing with mobility: Understanding access anytime, anywhere

The rapid and accelerating move towards the adoption and use of mobile technologies has increasingly provided people and organisations with the ability to work away from the office and on the move. The new ways of working afforded by these technologies are often characterised in terms of access to information and people ‘anytime, anywhere’. This paper presents a study of mobile workers that highlights different facets of access to remote people and information, and different facets of anytime, anywhere. Four key factors in mobile work are identified from the study: the role of planning, working in ‘dead time’, accessing remote technological and informational resources, and monitoring the activities of remote colleagues. By reflecting on these issues, we can better understand the role of technology and artefact use in mobile work and identify the opportunities for the development of appropriate technological solutions to support mobile workers

Prospectus, April 24, 1985

https://spark.parkland.edu/prospectus_1985/1011/thumbnail.jp

Population genetic diversity and fitness in multiple environments

<p>Abstract</p> <p>Background</p> <p>When a large number of alleles are lost from a population, increases in individual homozygosity may reduce individual fitness through inbreeding depression. Modest losses of allelic diversity may also negatively impact long-term population viability by reducing the capacity of populations to adapt to altered environments. However, it is not clear how much genetic diversity within populations may be lost before populations are put at significant risk. Development of tools to evaluate this relationship would be a valuable contribution to conservation biology. To address these issues, we have created an experimental system that uses laboratory populations of an estuarine crustacean, <it>Americamysis bahia </it>with experimentally manipulated levels of genetic diversity. We created replicate cultures with five distinct levels of genetic diversity and monitored them for 16 weeks in both permissive (ambient seawater) and stressful conditions (diluted seawater). The relationship between molecular genetic diversity at presumptive neutral loci and population vulnerability was assessed by AFLP analysis.</p> <p>Results</p> <p>Populations with very low genetic diversity demonstrated reduced fitness relative to high diversity populations even under permissive conditions. Population performance decreased in the stressful environment for all levels of genetic diversity relative to performance in the permissive environment. Twenty percent of the lowest diversity populations went extinct before the end of the study in permissive conditions, whereas 73% of the low diversity lines went extinct in the stressful environment. All high genetic diversity populations persisted for the duration of the study, although population sizes and reproduction were reduced under stressful environmental conditions. Levels of fitness varied more among replicate low diversity populations than among replicate populations with high genetic diversity. There was a significant correlation between AFLP diversity and population fitness overall; however, AFLP markers performed poorly at detecting modest but consequential losses of genetic diversity. High diversity lines in the stressful environment showed some evidence of relative improvement as the experiment progressed while the low diversity lines did not.</p> <p>Conclusions</p> <p>The combined effects of reduced average fitness and increased variability contributed to increased extinction rates for very low diversity populations. More modest losses of genetic diversity resulted in measurable decreases in population fitness; AFLP markers did not always detect these losses. However when AFLP markers indicated lost genetic diversity, these losses were associated with reduced population fitness.</p

Prospectus, October 17, 1984

SPORTS FEATURE LADY COBRAS TAKE IV INVITATIONAL; Assistance available; many services offered; Speech team takes honors; Goal is to overthrow the \u27masculine mind\u27; PC Happenings; Parkland hosts Foley exhibit; TV for Parents and Kids debuts; Workshop focuses on sexual abuse of young children; Career restructuring focus of workshop; Hearing topic for retirees; International students enrich us all; Did You Know...; Creative Corner...Especially for you!!; Paper Dolls Souls; History; Depression; Alone; Being & Becoming; So Much; Breakable Item; Thumbism; Diary; \u27Doom Story\u27-the terror escalates; Excerpts from Some Late Evening Thoughts While Anticipating That First Great Thunderstorm of a Dry Month; Midnight; Strength or weakness; The Ultimate Weapon; Photographer captures essence of traditional, contemporary Latin America; Celebrate the Arts Week; WPCD DJ likes job, Parkland; TV programs for parents scheduled; Classifieds; Peter Pan syndrome causes relationship problems; Experience Blues Explosion; Two comedians better than one; 1978 was cruel summer for Sullivan; 1984 is proving to be a sweet fall; Drive on to educate-issues important; Powell wins invitational; Stewart places 4th; Peterson prefers to use an eight-ironhttps://spark.parkland.edu/prospectus_1984/1008/thumbnail.jp