68 research outputs found
Metabolism of alcaligenes denitrificans in biofilm vs planktonic cells
Aims: To compare the effect of phosphorous concentration (200 mg P 1-1 and 20 mg P 1-1) on
the denitrifying efficiency of Alcaligenes denitrificans when in the form of planktonic cells or in the form of a biofilm, and to select the most adequate C/N ratio.
Methods and Results: Two types of assays were carried out: with planktonic cells and with
cells in biofilm form. Anoxic bottles with the appropriate C/N and phosphorous concentration
were incubated at 30°C and submitted to orbital shaking at 150 rev min-1. The specific activity
of cells in biofilm form, in terms of substrate consumption, was significantly higher than cells in
planktonic form. With regard to the effect of increasing phosphorous concentration, an increase
in specific activity was also only evident when the cells were in biofilm form.
Conclusions: The two forms showed different performances and phosphorous concentration
only markedly affected the biofilm form.
Significance and Impact of the Study: The importance of the C/N/P ratio in the
denitrification process is demonstrated. As there was no report in the literature about the
stoichiometric relationship of heterotrophic denitrification with citrate, its stoichiometry,
including the requirement for cell synthesis, was determined.Instituto de Biotecnologia e QuĂmica Fina (IBQF).
PRAXIS XXI
Dynamical Behavior of dilaton in de Sitter space
We study the dynamical behavior of the dilaton in the background of
three-dimensional Kerr-de Sitter space which is inspired from the low-energy
string effective action. The perturbation analysis around the cosmological
horizon of Kerr-de Sitter space reveals a mixing between the dilaton and other
fields. Introducing a gauge (dilaton gauge), we can disentangle this mixing
completely and obtain one decoupled dilaton equation. However it turns out that
this belongs to the tachyon. The stability of de Sitter solution with J=0 is
discussed. Finally we compute the dilaton absorption cross section to extract
information on the cosmological horizon of de Sitter space.Comment: 11 pages, reference added and a version to appear in PL
Can we Rationally Learn to Coordinate?
In this paper we examine the issue whether individual rationality considerations are sufficient to guarantee that individuals will learn to coordinate. This question is central in any discussion of whether social phenomena (read: conventions) can be explained in terms of a purely individualistic approach. We argue that the positive answers to this general question that have been obtained in some recent work require assumptions which incorporate some convention. This conclusion may be seen as supporting the viewpoint of institutional individualism in contrast to psychological individualism
Measurement of the Charged Multiplicities in b, c and Light Quark Events from Z0 Decays
Average charged multiplicities have been measured separately in , and
light quark () events from decays measured in the SLD experiment.
Impact parameters of charged tracks were used to select enriched samples of
and light quark events, and reconstructed charmed mesons were used to select
quark events. We measured the charged multiplicities:
,
, from
which we derived the differences between the total average charged
multiplicities of or quark events and light quark events: and . We compared
these measurements with those at lower center-of-mass energies and with
perturbative QCD predictions. These combined results are in agreement with the
QCD expectations and disfavor the hypothesis of flavor-independent
fragmentation.Comment: 19 pages LaTex, 4 EPS figures, to appear in Physics Letters
Heavy quarkonium: progress, puzzles, and opportunities
A golden age for heavy quarkonium physics dawned a decade ago, initiated by
the confluence of exciting advances in quantum chromodynamics (QCD) and an
explosion of related experimental activity. The early years of this period were
chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in
2004, which presented a comprehensive review of the status of the field at that
time and provided specific recommendations for further progress. However, the
broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles
could only be partially anticipated. Since the release of the YR, the BESII
program concluded only to give birth to BESIII; the -factories and CLEO-c
flourished; quarkonium production and polarization measurements at HERA and the
Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the
deconfinement regime. All these experiments leave legacies of quality,
precision, and unsolved mysteries for quarkonium physics, and therefore beg for
continuing investigations. The plethora of newly-found quarkonium-like states
unleashed a flood of theoretical investigations into new forms of matter such
as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the
spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b},
and b\bar{c} bound states have been shown to validate some theoretical
approaches to QCD and highlight lack of quantitative success for others. The
intriguing details of quarkonium suppression in heavy-ion collisions that have
emerged from RHIC have elevated the importance of separating hot- and
cold-nuclear-matter effects in quark-gluon plasma studies. This review
systematically addresses all these matters and concludes by prioritizing
directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K.
Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D.
Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A.
Petrov, P. Robbe, A. Vair
Representational predicaments for employees: Their impact on perceptions of supervisors\u27 individualized consideration and on employee job satisfaction
A representational predicament for a subordinate vis-à -vis his or her immediate superior involves perceptual incongruence with the superior about the subordinate\u27s work or work context, with unfavourable implications for the employee. An instrument to measure the incidence of two types of representational predicament, being neglected and negative slanting, was developed and then validated through an initial survey of 327 employees. A subsequent substantive survey with a fresh sample of 330 employees largely supported a conceptual model linking being neglected and negative slanting to perceptions of low individualized consideration by superiors and to low overall job satisfaction. The respondents in both surveys were all Hong Kong Chinese. Two case examples drawn from qualitative interviews illustrate and support the conceptual model. Based on the research findings, we recommend some practical exercises to use in training interventions with leaders and subordinates. © 2013 Copyright Taylor and Francis Group, LLC
Size Doesn't Matter: Towards a More Inclusive Philosophy of Biology
notes: As the primary author, OâMalley drafted the paper, and gathered and analysed data (scientific papers and talks). Conceptual analysis was conducted by both authors.publication-status: Publishedtypes: ArticlePhilosophers of biology, along with everyone else, generally perceive life to fall into two broad categories, the microbes and macrobes, and then pay most of their attention to the latter. âMacrobeâ is the word we propose for larger life forms, and we use it as part of an argument for microbial equality. We suggest that taking more notice of microbes â the dominant life form on the planet, both now and throughout evolutionary history â will transform some of the philosophy of biologyâs standard ideas on ontology, evolution, taxonomy and biodiversity. We set out a number of recent developments in microbiology â including biofilm formation, chemotaxis, quorum sensing and gene transfer â that highlight microbial capacities for cooperation and communication and break down conventional thinking that microbes are solely or primarily single-celled organisms. These insights also bring new perspectives to the levels of selection debate, as well as to discussions of the evolution and nature of multicellularity, and to neo-Darwinian understandings of evolutionary mechanisms. We show how these revisions lead to further complications for microbial classification and the philosophies of systematics and biodiversity. Incorporating microbial insights into the philosophy of biology will challenge many of its assumptions, but also give greater scope and depth to its investigations
InfluĂȘncia da relação cĂĄlcio:magnĂ©sio do corretivo na nodulação, produção e composição mineral da alfafa
Herpetofauna da årea do Igarapé Esperança na Reserva Extrativista Riozinho da Liberdade, Acre - Brasil
The farnesyltransferase ÎČâsubunit RAM1 regulates localization of RAS proteins and appressoriumâmediated infection in Magnaporthe oryzae
- âŠ