389 research outputs found

    Abundant Trimethylornithine Lipids and Specific Gene Sequences Are Indicative of Planctomycete Importance at the Oxic/Anoxic Interface in <i>Sphagnum</i>-Dominated Northern Wetlands

    Get PDF
    Northern wetlands make up a substantial terrestrial carbon sink and are often dominated by decay-resistant Sphagnum mosses.Recent studies have shown that planctomycetes appear to be involved in degradation of Sphagnum-derived debris. Novel trimethylornithine(TMO) lipids have recently been characterized as abundant lipids in various Sphagnum wetland planctomyceteisolates, but their occurrence in the environment has not yet been confirmed. We applied a combined intact polar lipid (IPL) andmolecular analysis of peat cores collected from two northern wetlands (Saxnäs Mosse [Sweden] and Obukhovskoye [Russia]) inorder to investigate the preferred niche and abundance of TMO-producing planctomycetes. TMOs were present throughout theprofiles of Sphagnum bogs, but their concentration peaked at the oxic/anoxic interface, which coincided with a maximum abundanceof planctomycete-specific 16S rRNA gene sequences. The sequences detected at the oxic/anoxic interface were affiliatedwith the Isosphaera group, while sequences present in the anoxic peat layers were related to an uncultured planctomycete group.Pyrosequencing-based analysis identified Planctomycetes as the major bacterial group at the oxic/anoxic interface at the Obukhovskoyepeat (54% of total 16S rRNA gene sequence reads), followed by Acidobacteria (19% reads), while in the Saxnäs Mossepeat, Acidobacteria were dominant (46%), and Planctomycetes contributed to 6% of the total reads. The detection of abundantTMO lipids in planctomycetes isolated from peat bogs and the lack of TMO production by cultures of acidobacteria suggest thatplanctomycetes are the producers of TMOs in peat bogs. The higher accumulation of TMOs at the oxic/anoxic interface and thechange in the planctomycete community with depth suggest that these IPLs could be synthesized as a response to changing redoxconditions at the oxic/anoxic interface

    Books

    Get PDF
    Oral cancer Oral Cancer: Epidemiology, Etiology and Pathology. Ed. by Colin Smith, Jens Pindborg and W. H. Binnie. Pp. ix + 106. Illustrated. R183,30. USA: Hemisphere. 1990.HPV and cervical cancer Human Papillomavirus and Cervical Cancer. Ed. by N. Munoz, F. X. Bosch and O. M. Jensen. Pp. xii + 155. Illustrated. France: International Agency for Research on Cancer. 1989.Child health Child Health in a Multicultural Society. Ed. by John Black. Pp. 75. Illustrated. ÂŁ7 (including postage). London: BMJ. 1989. (Available also from Libriger Book Distributors).Merck manual of geriatics Merck Manual of Geriatrics. Ed. by William B. Abrams The Andrew J. Fletcher. Pp. xxii + 1267. Illustrated. RI4,50. and I: Merck. 1990. USALiver disease Progress in Liver Diseases. Vol 9. Ed. by Hans Popper and Fenton Schaffner. Pp. xv + 750. Illustrated. RllO. England: Harcourt Brace Jovanovich. 1990.Clinical dietetics and nutrition Clinical Dietetics and Nutrition. 3rd ed. Ed. by F. P. Antia. Pp. xvi +438. Illustrated. Oxford: Oxford University Press. 1989.Atlas of human anatomy Wolf-Heidegger's Atlas of Human Anatomy. Ed. by H. F. Frick, B. Kummer and R. V. Putz. pp. viii + 599. ÂŁ(j(J. Basel: Karger. 1990.Health system decentralisation Health System Decentralization. Ed. by A. Mills, J. P. Vaughan, D. L. Smith and I. Tabibzadcll. pp. 151. Illustrated. SFr. 26. Geneva: World Health Organisation. 1990.Handbook of occupational medicine Handbook of Occupational Medicine. Ed. by Robert J. McCunney. Pp. xxiii + 510. Illustrated. Boston: Little, Brown. 1988.Leukaemia Leukaemia. 5th ed. Ed. by Edward S. Henderson and T. Andrew Lister. Pp. vii + 821. Illustrated. RHO. Kent: Harcoun Brace Jovanovich. 1990

    Python game design for children: Games and programming resources

    Get PDF
    This project is focused on helping middle and high school students learn how to program and think computationally. We are creating a set of resources that will be used by the students to understand programming, Python, and PyGames concepts. These resources will be used for teaching the two one-week summer camps through Clemson University\u27s Pre-Collegiate programs in June and July 2014. This camp has been offered at Georgia Tech and Clemson University for two summers using a drag and drop visual programming language to help students create games. The instructors have found that the camp attendees do not find the visual programming language to be challenging enough. Thus, we are designing curricula to teach introductory computing concepts with the Python and PyGames programming languages in a fun and creative way and to give students the opportunity to learn to design and program their own games. We are also designing and creating our own games as a way to learn the language and have examples for the kids in the camp to build upon. This project was initiated this semester and we will pilot resources this summer during the two weeks of camp. We will showcase the initial games and resources created for this project

    Carbon-isotope discrimination by leaves of Flaveria species exhibiting different amounts of C 3 -and C 4 -cycle co-function

    Full text link
    Carbon-isotope ratios were examined as δ 13 C values in several C 3 , C 4 , and C 3 −C 4 Flaveria species, and compared to predicted δ 13 C, values generated from theoretical models. The measured δ 13 C values were within 4‰ of those predicted from the models. The models were used to identify factors that contribute to C 3 -like δ 13 C values in C 3 −C 4 species that exhibit considerable C 4 -cycle activity. Two of the factors contributing to C 3 -like δ 13 C values are high CO 2 leakiness from the C 4 pathway and pi/pa values that were higher than C 4 congeners. A marked break occurred in the relationship between the percentage of atmospheric CO 2 assimilated through the C 4 cycle and the δ 13 C value. Below 50% C 4 -cycle assimialtion there was no significant relationship between the variables, but above 50% the δ 13 C values became less negative. These results demonstrate that the level of C 4 -cycle expression can increase from, 0 to 50% with little integration of carbon transfer from the C 4 to the C 3 cycle. As expression increaces above 50%, however, increased integration of C 3 - and C 4 -cycle co-function occurs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47473/1/425_2004_Article_BF00394765.pd

    The \u3cem\u3eChlamydomonas\u3c/em\u3e Genome Reveals the Evolution of Key Animal and Plant Functions

    Get PDF
    Chlamydomonas reinhardtii is a unicellular green alga whose lineage diverged from land plants over 1 billion years ago. It is a model system for studying chloroplast-based photosynthesis, as well as the structure, assembly, and function of eukaryotic flagella (cilia), which were inherited from the common ancestor of plants and animals, but lost in land plants. We sequenced the ∟120-megabase nuclear genome of Chlamydomonas and performed comparative phylogenomic analyses, identifying genes encoding uncharacterized proteins that are likely associated with the function and biogenesis of chloroplasts or eukaryotic flagella. Analyses of the Chlamydomonas genome advance our understanding of the ancestral eukaryotic cell, reveal previously unknown genes associated with photosynthetic and flagellar functions, and establish links between ciliopathy and the composition and function of flagella

    The six-minute walk test in community dwelling elderly: influence of health status.

    Get PDF
    BACKGROUND: The 6 minutes walk test (6MWT) is a useful assessment instrument for the exercise capacity of elderly persons. The impact of the health status on the 6MWT-distance in elderly, however, remains unclear, reducing its value in clinical settings. The objective of this study was to investigate to what extent the 6MWT-distance in community dwelling elderly is determined by health conditions. METHODS: One hundred and fifty-six community dwelling elderly people (53 male, 103 female) were assessed for health status and performed the 6MWT. After clinical evaluation, electrocardiography and laboratory examination participants were categorized into a stratified six-level classification system according to their health status, going from A (completely healthy) to D (signs of active disease at the moment of examination). RESULTS: The mean 6MWT-distance was 603 m (SD = 178). The 6MWT-distance decreased significantly with increasing age (ANOVA p = 0.0001) and with worsening health status (ANCOVA, corrected for age p < 0.001). A multiple linear regression model with health status, age and gender as independent variables explained 31% of the 6MWT-distance variability. Anthropometrical measures (stature, weight and BMI) did not significantly improve the prediction model. A significant relationship between 6MWT-distance and stature was only present in category A (completely healthy). CONCLUSIONS: Significant differences in 6MWT-distance are observed according to health status in community-dwelling elderly persons. The proposed health categorizing system for elderly people is able to distinguish persons with lower physical exercise capacity and can be useful when advising physical trainers for seniors

    Risk of infection and adverse outcomes among pregnant working women in selected occupational groups: A study in the Danish National Birth Cohort

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Exposure to infectious pathogens is a frequent occupational hazard for women who work with patients, children, animals or animal products. The purpose of the present study is to investigate if women working in occupations where exposure to infections agents is common have a high risk of infections and adverse pregnancy outcomes.</p> <p>Methods</p> <p>We used data from the Danish National Birth Cohort, a population-based cohort study and studied the risk of Infection and adverse outcomes in pregnant women working with patients, with children, with food products or with animals. The regression analysis were adjusted for the following covariates: maternal age, parity, history of miscarriage, socio-occupational status, pre-pregnancy body mass index, smoking habit, alcohol consumption.</p> <p>Results</p> <p>Pregnant women who worked with patients or children or food products had an excess risk of sick leave during pregnancy for more than three days. Most of negative reproductive outcomes were not increased in these occupations but the prevalence of congenital anomalies (CAs) was slightly higher in children of women who worked with patients. The prevalence of small for gestational age infants was higher among women who worked with food products. There was no association between occupation infections during pregnancy and the risk of reproductive failures in the exposed groups. However, the prevalence of CAs was slightly higher among children of women who suffered some infection during pregnancy but the numbers were small.</p> <p>Conclusion</p> <p>Despite preventive strategies, working in specific jobs during pregnancy may impose a higher risk of infections, and working in some of these occupations may impose a slightly higher risk of CAs in their offspring. Most other reproductive failures were not increased in these occupations.</p
    • …
    corecore