1,097 research outputs found
A Propos of Ricardo Rojas' Ollantay.
A Propos of Ricardo Rojas' Ollantay
The Post-Boom in Spanish American Fiction
The article discusses the dating of the beginning of the Post-Boom, the factors involved in discussing it, and lists possible representative writers belonging to it. The views of Skármeta, Allende and others are reported and a list of possible Post-Boom characteristics is suggested. It is argued that there are difficulties in the way of relating the Post-Boom easily to Postmodernism, but that the notion of Post-colonialism may prove helpful in future criticism
Introduction to the special issue
Introduction to the special issu
On the Dark Side: Conrad\u27s The Secret Sharer and Valenzuela\u27s La palabra asesino
Conrad’s famous “The Secret Sharer” and the short story “La palabra asesino” [“The Word ‘Killer’” in its English translation] by the Argentine Luisa Valenzuela both concern psychological self-exploration and self-discovery, through contact with a killer, a situation which challenges conventional moral standards. It is suggested that a comparison between the two stories may throw reciprocal light on both of them. In each story an act or acts of murder becomes a trigger which sets off a train of psychological events, somewhat different in the two cases. Discussion of the differences highlights the authors\u27 priorities and the significance they attach to the darker side of the human personality. Both stories are highly ambiguous; but the ambiguity serves a different purpose in each case. Conrad is concerned with psychological doubling ; Valenzuela with exploration of aspects of the human personality which in turn may be related to aspects of Argentina\u27s collective personality as it expressed itself during the “Dirty War.” An examination of the different forces in play in the two stories improves our understanding of both
Impact of the Holocene Transgression on the Atlantic Coastline of Nova Scotia
As analogs for impact of a future sea-level rise on the coast of Nova Scotia (eastern Canada), geological data and information on relative sea-level changes are examined at three different time scales. Relative sea level rose swiftly during the early Holocene, at a maximum rate of 11 m/ka at 7500 radiocarbon years BP. Freshwater, salt-marsh, and estuarine sediments that formed during this period have been located on the inner shelf. After 5000 BP the rate slackened to about 2 m/ka. Despite overall submergence and coastal retreat since that time, gravel barriers have persisted where large amounts of sediment have been added to the littoral system by erosion of glacial deposits. The barriers often display evidence of early progradational phases in the form of gravel beach ridges, partly or wholly submerged in lagoons behind contemporary storm beaches. Tide-gauge data from the past century show submergence rates averaging 3.5 mm/a, well in excess of the longterm trend. The response of the coastline to this rapid rise is complex. Unconsolidated cliffs (bluffs) retreat at up to 5 m/a during initial exposure to wave attack and during extreme storm events, but at lesser rates (8 m/a) in some locations, but low elsewhere, in some cases showing almost no movement over the past 10 years, and neighbouring beaches are sometimes observed to behave in completely different ways. Sediment released by coastal erosion finds its way into nearby estuaries, causing growth of flood-tidal deltas and marsh aggradation. If a global rise in sea level occurs, the processes of erosion and sedimentation operating along the coast of Nova Scotia during the Holocene are expected to continue in a similar fashion, but rates of change will increase at many locations.Les données géologiques et les connaissances sur les changements du niveau marin relatif sont étudiées à trois échelles temporelles en tant qu'analogues des conséquences d'une future hausse du niveau marin sur la côte de la Nouvelle-Écosse. Le niveau marin relatif s'est rapidement élevé au cours de l'Holocène inférieur, jusqu'au taux maximal de 11 m/ka à 7500 BP. Des sédiments estuariens ou issus de marais salants et d'eau douce datant de cette période ont été localisés sur le plateau continental intérieur. Après 5000 BP le taux a diminué jusqu'à 2 m/ka. En dépit de la submersion de la région côtière et de son dégagement subséquent, les cordons littoraux de gravier ont persisté là où de grandes quantités de sédiments ont été mis en place sur le littoral par érosion des dépôts glaciaires. Les cordons montrent souvent des indices de phases de progression sous la forme de crêtes de graviers, partiellement ou entièrement submergés dans les lagunes situées derrière les plages de tempêtes contemporaines. Les données marégraphiques du siècle dernier font ressortir un taux de submersion d'environ 3,5 mm/a, taux nettement plus élevé que celui de la tendance à long terme. La réponse du littoral à cette hausse rapide est complexe. Les falaises non consolidées peuvent reculer jusqu'à 5 m/a au début de leur exposition aux fortes vagues et pendant les plus fortes tempêtes et à un rythme beaucoup plus lent (8 m/a) par endroits, lent ailleurs; certaines plages sont presque immobiles depuis 10 ans, alors que les plages voisines se comportent de façon tout à fait différente. Les sédiments libérés par l'érosion littorale se retrouvent dans les estuaires les plus proches, provoquant l'expansion des deltas d'inondation et l'extension des marais. Si une hausse globale du niveau marin survenait, les processus d'érosion et de sédimentation qui se sont manifestés le long de la côte de la Nouvelle-Écosse pendant l'Holocène agiront de façon semblable, mais le rythme des changements augmentera dans plusieurs sites
Production of 10-methyl branched fatty acids in yeast
Background: Despite the environmental value of biobased lubricants, they account for less than 2% of global lubricant use due to poor thermo-oxidative stability arising from the presence of unsaturated double bonds. Methyl branched fatty acids (BFAs), particularly those with branching near the acyl-chain mid-point, are a high-performance alternative to existing vegetable oils because of their low melting temperature and full saturation. Results: We cloned and characterized two pathways to produce 10-methyl BFAs isolated from actinomycetes and γ-proteobacteria. In the two-step bfa pathway of actinomycetes, BfaB methylates Δ9 unsaturated fatty acids to form 10-methylene BFAs, and subsequently, BfaA reduces the double bond to produce a fully saturated 10-methyl branched fatty acid. A BfaA-B fusion enzyme increased the conversion efficiency of 10-methyl BFAs. The ten-methyl palmitate production (tmp) pathway of γ-proteobacteria produces a 10-methylene intermediate, but the TmpA putative reductase was not active in E. coli or yeast. Comparison of BfaB and TmpB activities revealed a range of substrate specificities from C14-C20 fatty acids unsaturated at the Δ9, Δ10 or Δ11 position. We demonstrated efficient production of 10-methylene and 10-methyl BFAs in S. cerevisiae by secretion of free fatty acids and in Y. lipolytica as triacylglycerides, which accumulated to levels more than 35% of total cellular fatty acids. Conclusions: We report here the characterization of a set of enzymes that can produce position-specific methylene and methyl branched fatty acids. Yeast expression of bfa enzymes can provide a platform for the large-scale production of branched fatty acids suitable for industrial and consumer applications
Butterfly-parasitoid-hostplant interactions in Western Palaearctic Hesperiidae: a DNA barcoding reference library
The study of ecological interactions between plants, phytophagous insects and their natural enemies is an essential but challenging component for understanding ecosystem dynamics. Molecular methods such as DNA barcoding can help elucidate these interactions. In this study, we employed DNA barcoding to establish hostplant and parasitoid interactions with hesperiid butterflies, using a complete reference library for Hesperiidae of continental Europe and north-western Africa (53 species, 100% of those recorded) based on 2934 sequences from 38 countries. A total of 233 hostplant and parasitoid interactions are presented, some recovered by DNA barcoding larval remains or parasitoid cocoons. Combining DNA barcode results with other lines of evidence allowed 94% species-level identification for Hesperiidae, but success was lower for parasitoids, in part due to unresolved taxonomy. Potential cases of cryptic diversity, both in Hesperiidae and Microgastrinae, are discussed. We briefly analyse the resulting interaction networks. Future DNA barcoding initiatives in this region should focus attention on north-western Africa and on parasitoids, because in these cases barcode reference libraries and taxonomy are less well developed.Support for this research was provided by the Spanish National Research Council (CSIC) with a JAE-Intro fellowship for the introduction to research to ETD (reference numbers JAEINT_20_00248 and JAEINT20_EX_0638) and by projects PID2019-107078GB-I00/MCIN/AEI/10.13039/501100011033 and 2017-SGR-991 (Generalitat de Catalunya) to RV, and PID2020-117739GA-I00/MCIN/AEI/10.13039/501100011033 to GT. We thank the Rachadaphiseksomphot Fund, Graduate School, Chulalongkorn University, for the award of a Senior Postdoctoral Fellowship to DLJQ. Further support for this research was provided by the Academy of Finland (Academy Research Fellow, decision no. 328895) to VD. PDNH acknowledges support from Genome Canada through Ontario Genomics. BV has been funded by the CERCA Programme of the Generalitat de Catalunya and by the Grant RYC-22243-2017, whose PI is Josep Sardanyés. SV was supported by the Spanish Ministry of Economy and Competitiveness, grant PID2020-117822GB-I00 MINEICO/AEI/ FEDER and the European Union.INTRODUCTION
MATERIAL AND METHODS
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CONCLUSION
SUPPORTING INFORMATION
ACKNOWLEDGEMENTS
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Supplementary dat
Limits on the ultra-bright Fast Radio Burst population from the CHIME Pathfinder
We present results from a new incoherent-beam Fast Radio Burst (FRB) search
on the Canadian Hydrogen Intensity Mapping Experiment (CHIME) Pathfinder. Its
large instantaneous field of view (FoV) and relative thermal insensitivity
allow us to probe the ultra-bright tail of the FRB distribution, and to test a
recent claim that this distribution's slope, , is quite small. A 256-input incoherent beamformer was
deployed on the CHIME Pathfinder for this purpose. If the FRB distribution were
described by a single power-law with , we would expect an FRB
detection every few days, making this the fastest survey on sky at present. We
collected 1268 hours of data, amounting to one of the largest exposures of any
FRB survey, with over 2.4\,\,10\,deg\,hrs. Having seen no
bursts, we have constrained the rate of extremely bright events to
\,sky\,day above \,220 Jy\,ms
for between 1.3 and 100\,ms, at 400--800\,MHz. The non-detection also
allows us to rule out with 95 confidence, after
marginalizing over uncertainties in the GBT rate at 700--900\,MHz, though we
show that for a cosmological population and a large dynamic range in flux
density, is brightness-dependent. Since FRBs now extend to large
enough distances that non-Euclidean effects are significant, there is still
expected to be a dearth of faint events and relative excess of bright events.
Nevertheless we have constrained the allowed number of ultra-intense FRBs.
While this does not have significant implications for deeper, large-FoV surveys
like full CHIME and APERTIF, it does have important consequences for other
wide-field, small dish experiments
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