Binding of terbium(III) to yeast enolase

Several independent criteria indicate 2 mol of terbium(III) bind to yeast enolase in the absence of substrate-fluorescence titrations of enzyme and metal, effects on thermal stability and published ultrafiltration and inhibition experiments. These measurements also suggest the terbium binding sites are the same as those normally occupied by “conformational” magnesium. Terbium binds much more strongly than magnesium, however, and measurements of the kinetics of the absorbance change in the terbium-enzyme on adding excess EDTA suggest the terbium-enzyme dissociation constant is about $\text{1}\text{500}$ that of the magnesium-enzyme. Measurements of enzyme activity as a function of substrate concentration show that terbium permits no enzymatic activity. However, magnesium competes more effectively with the lanthanide if the substrate analogue 3-aminoenolpyruvate 2-phosphate (AEP) is present.The fluorescence of the lanthanide is not readily observed on exciting the terbium-enzyme at 280 nm, indicating the absence of tyrosines or tryptophans in the coordination sphere of the metal. Excitation of terbium using 488 nm radiation from an argon ion laser shows the fluorescence of the metal is enhanced by binding to the enzyme. EDTA and carbonate have similar effects. This suggests carboxyl groups are involved in binding metal at the conformational sites of yeast enolase. Measurements of lifetimes of enzyme-bound terbium in the presence and absence of D₂O indicated three moles of water remained on each of the bound metals, independently of the buffer used. If enzyme-bound terbium is assumed to be nine-coordinate, the metal must bind to six groups from the enzyme. The presence of substrate does not markedly affect the emission spectrum of the bound terbium or the number of water molecules remaining on the metal, but calorimetric measurements show that substrate binds to the terbium enzyme.     

JUSTICE, STIGMA, AND THE NEW EPIDEMIOLOGY OF HEALTH DISPARITIES

Recent research in epidemiology has identified a number of factors beyond access to medical care that contribute to health disparities. Among the so-called socioeconomic determinants of health are income, education, and the distribution of social capital. One factor that has been overlooked in this discussion is the effect that stigmatization can have on health. In this paper, I identify two ways that social stigma can create health disparities: directly by impacting health-care seeking behaviour and indirectly through the internalization of negative interpersonal judgments. I then argue that social arrangements that foster self-respect can reduce the impact of stigmatization on health disparities. I conclude by showing how John Rawls' conception of justice can be used to address the intersection of stigma, health, and self-respect, in contrast to critics of his position, who have seen him as excessively focused on the allocation of material goods.     

Ornithine decarboxylase and polyamines in the resumption of cycling by diluted and reoxygenated mammalian cells

Plateau-phase V79 Chinese hamster cells induced to reenter the proliferative cell cycle from G1/G0 by dilution in fresh medium showed an early increase in ornithine decarboxylase (ODC) followed by increases in some polyamines and in DNA synthesis. In contrast, cells accumulated in G1/G0 by growth in extreme hypoxia for 60 h and induced to recycle by reoxygenation did not respond with early increases in either ODC or polyamines.     

人工髋关节置换术在320例股骨头缺血性坏死中的治疗体会

目的：探讨人工髋关节置换术在治疗股骨头缺血性坏死（ANFH）中的临床疗效。方法：选择2007年2月-2011年2月我院收治的320例（340髋）股骨头缺血性坏死患者,均采用人工髋关节置换术对患者进行治疗,其中160例（172髋）患者应用骨水泥型假体进行治疗,另外160例（168）患者采用非骨水泥型假体进行治疗。采用Harris评分对患者手术前后的髋关节功能情况进行评价,并比较骨水泥治疗组和非骨水泥治疗组的临床疗效。结果：患者均获得随访,随访时间为3～18个月。全部患者手术后的Harris评分明显高于手术前,差异有统计学意义（P〈0．05）。骨水泥治疗组和非骨水泥治疗组在术后出血量、术后Harris评分及住院时间方面的差异无统计学意义（P〉0．05）,但非骨水泥治疗组的并发症发生率明显低于骨水泥治疗组（P〈0．05）。结论：采用人工髋关节置换术治疗ANFH疗效显著,能明显改善患者的生活质量,骨水泥型假体与非骨水泥型假体的治疗效果相当,应根据患者的具体情况进行合理的选择。     

John Marshall's Kalahari Family

Throughout his career and through his films, John Marshall has embodied many representational debates in anthropology and ethnographic media production. With A Kalahari Family, Marshall has provided his most reflexive film to date as well as a comprehensive visual record of 50 years of transition among the Ju'hoansi, from lingering, hunter-gatherer subsistence to problematic and often tragic contemporary living conditions. A Kalahari Family bears witness to the negative effects a racist ideology and varied development agendas have had on an indigenous group of people, and the transformative effects they continue to have. In the film, the audience also witnesses the evolution of John Marshall himself, from naïve, inexperienced teenager engaging an exotic other, with all the inherent cultural baggage of a Western perspective, to his eventual emergence as a filmmaker and a dedicated advocate for the people with whom he has become so involved.     

John W. Burgess,the racial state and the making of the American science of politics

This article examines the place of racial ideas in the constitution of political science as an academic discipline in the USA. For the Gilded Age generation that built the first PhD-granting departments in political science in the country, ‘race’ was the source of sovereignty, the basis of democratic legitimacy and a tool for delineating democracy's borders. It was also an important element of that cohort's aspiration to a ‘science’ of politics, distinct from what they viewed as the ‘abstract and formal’ theorizing of the eighteenth and early nineteenth centuries. Moreover, while the brand of racialism that characterized this founding moment came to seem outmoded within a few decades, in the 1920s political scientists seeking once again to claim an empirical, scientific basis for their discipline – and for American democracy – turned to new accounts and sciences of race.     

Ovarian maturity,egg development,and offspring generation of the deep-water shrimp Plesionika edwardsii (Decapoda,Pandalidae) from three isolated populations in the eastern North Atlantic

Ovarian maturity, egg development and brood size were analysed for three isolated populations (Madeira, the Canary Islands and Cape Verde Islands) of Plesionika edwardsii (Decapoda, Pandalidae) in the eastern Atlantic. Multiple colour patterns were observed at the same ovarian maturity stage, which was verified histologically, invalidating the extensive use of ovarian colour as a maturity stage criterion. The physiological size at sexual maturity, based on the maturity of the ovaries, was higher in Madeira (carapace length of 19.73?mm) and decreased to the Cape Verdes (16.39?mm). Synchronic ovarian maturation was observed during the embryo incubation process, and ovigerous females bearing embryos at the final stage of development were found throughout the year. Females are multiple spawners during the reproductive season, after which the reproductive process ends and a rest period begins. The absence of females larger than the size at sexual maturity with ovaries in Stage 1, the incubation of embryos in the final developmental stages, suggests that the resting period begins with a process that reabsorbs the energy located in the ovaries and that the resting period occurs asynchronously in females in each of the studied populations. Embryo size was independent of female body size in the three populations studied, but increased with the developmental stage. A power equation was used to describe the relationship between brood size and female body size in the three areas studied. The mean number of external Stage I embryos carried by females decreased from Madeira (n?=?7868) to the Cape Verdes (n?=?3781), where less energy, in terms of the number of embryos and the size of the eggs, was invested in reproduction. Although female size decreases from north to south, the egg number was higher in Madeira than in the Cape Verdes for the same size range.     

An Ichnotaxonomic Approach to Wrinkled Microbially Induced Sedimentary Structures

Microbially induced sedimentary structures (MISS) are an important facet of recent paleoichnological work because of their taphonomic implications. MISS are extensively studied in terms of their formation processes, recognition in the ancient record, and their diverse morphologies. Classification and terminology schemes are based on their appearance and mode of formation; however, the taxonomic treatment of MISS remains debated. Traditionally MISS have been considered sedimentary structures, and arguments have been made that they cannot be treated as trace fossils under the International Code of Zoological Nomenclature (ICZN) due to MISS being formed by communities of microbiota including algae, cyanobacteria, and others, rather than a single tracemaker. Here, we reexamine MISS using an ichnotaxonomic approach and apply ichnologic terminology and binomial names. Upon reexamining the holotype of Kinneyia Walcott, a genus commonly used to describe some MISS, we argue it cannot be used to correctly describe wrinkle or ripple-like features seen in MISS, and we agree with previous authors that Kinneyia is likely not biogenic in origin. We here assign a new ichnogenus and ichnospecies, Rugalichnus matthewii, to ripple-like sedimentary wrinkle marks known as MISS, separating them from the nomen dubium genus Kinneyia.