403 research outputs found
Plasticity in the proteome of Emiliania huxleyi CCMP 1516 to extremes of light is highly targeted
No full textSummary
Optimality principles are often applied in theoretical studies of microalgal ecophysiology to predict changes in allocation of resources to different metabolic pathways, and optimal acclimation is likely to involve changes in the proteome, which typically accounts for > 50% of cellular nitrogen (N).
We tested the hypothesis that acclimation of the microalga Emiliania huxleyi CCMP 1516 to suboptimal vs supraoptimal light involves large changes in the proteome as cells rebalance the capacities to absorb light, fix CO2, perform biosynthesis and resist photooxidative stress.
Emiliania huxleyi was grown in nutrient‐replete continuous culture at 30 (LL) and 1000 μmol photons m−2 s−1 (HL), and changes in the proteome were assessed by LC‐MS/MS shotgun proteomics. Changes were most evident in proteins involved in the light reactions of photosynthesis; the relative abundance of photosystem I (PSI) and PSII proteins was 70% greater in LL, light‐harvesting fucoxanthin–chlorophyll proteins (Lhcfs) were up to 500% greater in LL and photoprotective LI818 proteins were 300% greater in HL.
The marked changes in the abundances of Lhcfs and LI818s, together with the limited plasticity in the bulk of the E. huxleyi proteome, probably reflect evolutionary pressures to provide energy to maintain metabolic capabilities in stochastic light environments encountered by this species in nature.
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The trade-off between the light-harvesting and photoprotective functions of fucoxanthin-chlorophyll proteins dominates light acclimation in Emiliania huxleyi (clone CCMP 1516)
No full textMechanistic understanding of the costs and benefits of photoacclimation requires knowledge of how photophysiology is affected by changes in the molecular structure of the chloroplast.We tested the hypothesis that changes in the light dependencies of photosynthesis, nonphotochemical quenching and PSII photoinactivation arises from changes in the abundances of chloroplast proteins in Emiliania huxleyi strain CCMP 1516 grown at 30 (Low Light; LL) and 1000 (High Light; HL) µmol photons m-2 s-1 photon flux densities.Carbon-specific light-saturated gross photosynthesis rates were not significantly different between cells acclimated to LL and HL. Acclimation to LL benefited cells by increasing biomass-specific light absorption and gross photosynthesis rates under low light, whereas acclimation to HL benefited cells by reducing the rate of photoinactivation of PSII under high light. Differences in the relative abundances of proteins assigned to light-harvesting (Lhcf), photoprotection (LI818-like), and the photosystem II (PSII) core complex accompanied differences in photophysiology: specifically, Lhcf:PSII was greater under LL, whereas LI818:PSII was greater in HL.Thus, photoacclimation in E. huxleyi involved a trade-off amongst the characteristics of light absorption and photoprotection, which could be attributed to changes in the abundance and composition of proteins in the light-harvesting antenna of PSII
Spaces of contestation: the everyday experiences of ten African migrants in Cape Town
No full textIncludes bibliographical references.Xenophobia in South Africa is so overt that it has take a covert form. The 'xenocide' events that took place in 2008 were called xenophobic acts. It is the recurrent denialism of xenophobia on an everyday basis that this project has explored through the narrative accounts of ten African migrants in Cape Town. The lived everyday experiences of ten African migrants have brought forward the central argument of this thesis. From the data, it is evident that as a reponse to everyday pressures of prejudices and xenophobia in social and physical spaces, African migrants have developed mutable, unsettled and vagrant identities in order to cope with everyday low level violence. This argument emerged as four key stressors have been identified as the components of a more substantial explanation of xenophobia in South Africa. The four key components are: the enforcement of identity (national and group), the demarcation of spaces of belonging, the experiences of economic insecurity, and lastly a 'culture of violence' in South Africa. This thesis argues that these four stressors are the result of an on-going active process of xenophobic attitudes
Diritto alla città e beni comuni.
No full textThe article discusses the concept of the right to the city. The expression was conceived by Henri Lefebvre, but with
the passage of time it lost the connection to its author (through
the superficial and careless use made of the term in the literature) and consequently
also its strongly radical meaning. The article analyses the different contemporary interpretations of the concept of the right to the city and proposes some new ones
The Urban Political Ecology of Post-industrial Scottish Towns: Examining Greengairs and Ravenscraig
No full textUrban ecological politics is shaped by both moments of concerted action and more silent perceptions and responses. Instead of only being evident in situations of organised protest, the politics of urban ecology is also manifested, in material and symbolic terms, in the daily life of the residents. The fragmentation of urban political ecology turns out to be an important element in the affirmation of post-political forms of urban governance. Those issues were the object of fieldwork research carried out in Greengairs and Ravenscraig, two towns in North Lanarkshire, near Glasgow, with the goal of unravelling the understanding and the coping mechanisms of environmentally deprived residents. The towns are permeated by a widespread, often dissimulated, political ecology that is nonetheless always present. Empirical results demonstrate that a more comprehensive handling of the political ecology of the urban is crucial in order to halt the sources of marginalisation and ecological degradation
Barrier to abducting a woman and her serious fear in the light of the sentence of Roman Rota c. Lefebvre of 24.05.1969
No full textThe case regards the marriage of Maria and Wincety, who concluded the marriage on 15 June 1959. The woman claimed to have been kidnapped and, therefore, entered into the relationship without her consent. Little wonder that after eight days the couple was separated.Later, Mary filed a complaint regarding the invalidity of the marriage to the Campaign Tribunal on 27.10.1959 indicating two important invalidity titles: abduction, serious coercion and fear. On 6 March 1963 a negative sentence on both counts was passed, the plaintiff filed an appeal to the Appellate Tribunal of Vicariatus Urbis, which on 26 April 1968 issued a positive judgment for both the first and the second invalidity title. After filing the appeal by the defender of the marital bond, the case was considered by the Roman Rota Turnus c. Lefebvre. On 24 May 1969 the judgment was passed invalidating the marriage only with regard to the serious coercion and fear on the side of the plaintiff.Presenting and commenting on the Rota judgment the author places emphasis on the factual motivation
Przeszkoda uprowadzenia kobiety oraz ciężka bojaźń po jej stronie w świetle wyroku Roty Rzymskiej c. Lefebvre z 24 maja 1969 r.
No full textThe case regards the marriage of Maria and Wincety, who concluded the marriage on 15 June 1959. The woman claimed to have been kidnapped and, therefore, entered into the relationship without her consent. Little wonder that after eight days the couple was separated.Later, Mary filed a complaint regarding the invalidity of the marriage to the Campaign Tribunal on 27.10.1959 indicating two important invalidity titles: abduction, serious coercion and fear. On 6 March 1963 a negative sentence on both counts was passed, the plaintiff filed an appeal to the Appellate Tribunal of Vicariatus Urbis, which on 26 April 1968 issued a positive judgment for both the first and the second invalidity title. After filing the appeal by the defender of the marital bond, the case was considered by the Roman Rota Turnus c. Lefebvre. On 24 May 1969 the judgment was passed invalidating the marriage only with regard to the serious coercion and fear on the side of the plaintiff.Presenting and commenting on the Rota judgment the author places emphasis on the factual motivation
The Recent Evolution of Retirement Patterns in Canada
No full textUsing data from three waves of the General Social Survey on retirement and older workers (1994, 2002 and 2007), we document the evolution of retirement patterns over the last three decades. We combined the analysis of retirement ages of actual retirees with data on expected retirement ages of current workers to create a longer perspective on changes in retirement behaviour in Canada. We also investigate trends in work after retirement. Our findings are in line with findings from other countries. There is an upward trend in retirement ages which likely started around year 2000 for cohorts born after 1945. This trend contrasts with the slow decline in retirement ages observed prior to the end of the millennium. While the downward trend was likely due to factors such as the offering of early retirement programs in private firms, the upward trend is likely to be caused by a wider variety of sources, including better health, less pervasive defined benefit pensions and in general less generous pensions.Retirement, aging, older workers, expectations
La mort parfumée des poux. Petite archéologie de la publicité pharmaceutique radiophonique (Suivi d'un Historique des spécialités de C. et A. Salacrou)
No full text« La mort parfumée des poux ». Archeology of the radio pharmaceutical advertisement.
After Second World War, a debate sets in France the partisans and the detractors of the radio advertisement, in particular pharmaceutical advertisement. In this article, the author revises campaigns led, during the thirties, by Robert Desnos for Armand Salacrou.Au lendemain de la Seconde Guerre mondiale, un débat oppose en France les partisans et détracteurs de la publicité radiophonique. La réclame pharmaceutique, très présente sur les ondes durant les années 1930, est au coeur de la polémique. Dans cet article, l'auteur réexamine en particulier les campagnes menées par Robert Desnos et son équipe, pour la promotion des produits pharmaceutiques de Camille et Armand Salacrou.Lefebvre Thierry. La mort parfumée des poux. Petite archéologie de la publicité pharmaceutique radiophonique (Suivi d'un Historique des spécialités de C. et A. Salacrou). In: Revue d'histoire de la pharmacie, 90ᵉ année, n°336, 2002. pp. 647-665
THE N C \ (=3) STATE: AN OPPORTUNITY FOR SPIN-ORBIT CHICANERY
No full textAuthor Institution: Department of Chemistry, MIT, Cambridge MA 02139; Department of Physics and Centre for Laser, Atomic, and Molecular Sciences, University of New Brunswick, Fredericton, CanadaThe N C \ (=3) state has been fully characterized by observation and rotational analysis of the N C --A \ (3-1) band. The spin-splittings in the C \ state are observed}, 081102 (2006).} (see previous presentation) and are found to be consistent with semi-empirical predictions of diagonal and isoconfigurational off-diagonal spin-orbit coupling constants.}, 081103 (2006).} A short tutorial on prediction of spin-orbit matrix elements will be presented, drawing heavily on material presented in "The Spectra and Dynamics of Diatomic Molecules" by H. Lefebvre-Brion and RWF
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