Aproximació a les investigacions empíriques en traducció: aplicació al projecte TRACE

L'objectiu d'aquest treball és el d'obtenir informació sobre investigacions empíricoexperimentals (centrant-nos en el procés de la traducció) amb vista a aplicar-la al projecte TRACE que duu a terme el grup d'investigació Tradumàtica. A partir d'una recerca bibliogràfica a revistes especialitzades i bases de dades, seleccionem setze articles representatius de la recerca en aquest camp, dels quals extraiem informació sobre el disseny. Aquesta informació ens serveix primer per a analitzar els instruments i el disseny —quant als subjectes i els materials— emprats en les investigacions i, després, per a veure com s'han utilitzat en els casos seleccionats. Finalment, n'extraiem conclusions amb el rerefons del projecte TRACE

Trace-element and phosphorus contents in sediment associated with Cretaceous oceanic anoxic events

ABSTRACT : During my SNSF-funded Ph.D. thesis project, I studied the evolution of redox conditions and organic-carbon preservation in the western Tethyan realm during three major positive excursions in the Cretaceous δ13C record, corresponding to the Valanginian, Early Aptian and Late Cenomanian. These periods were characterized by important global environmental and climate change, which was associated with perturbations in the carbon cycle. For the period of the Valanginian δ13C excursion, total organic carbon (TOC) contents and the quality of preserved organic matter are typical of oxic pelagic settings in the western Tethys. This is confirmed by the absence of major excursions in the stratigraphic distribution of RSTE during the δ13C shift. Published TOC data from other parts of the Valanginian oceans indicate that dys- to anaerobic zones were restricted to marginal seas within the Atlantic and Southern Ocean, and to the Pacific. Phosphorus (P) and mineralogical contents suggest a stepwise climatic evolution during the Valanginian, with a humid and warm climate prior to the δ13C shift leading to an increase in continental runoff. During the δ13C shift, a decrease in detrital input and P contents suggests a change in the climate towards more and conditions. During the early Aptian oceanic anoxic event (OAE 1a), a general increase followed by a rapid decrease in P contents suggests enhanced nutrient input at the beginning of OAE 1a. The return to lower values during OAE 1 a, associated with an increase in RSTE contents, may have been related to the weakened capacity to retain P in the sedimentary reservoir due to bottom-water oxygen depletion. In basinal settings, the RSTE distribution indicates well-developed anoxic conditions during OAE la, whereas in the shallower-water environments, conditions were oxic to suboxic, rather than anoxic. Furthermore, in the deeper part of the Tethys, two distinct enrichments have been observed, indicating fluctuations in the intensity of water column anoxia during the δ73C excursion. We also studied the effect of the end-Cenomanian oceanic anoxic event (OAE 2) on an expanded section in the Chrummflueschlucht (E of Euthal, Ct Switzerland). The goal here was to identify paleoceanographic and paleoenvironmental conditions during OAE 2 in this part of the northern Tethyan margin. The results show that this section is one of the most complete sections for the Cenomanian-Turonian boundary interval known from the Helvetic realm, despite a small hiatus between sediments corresponding to peaks 1 and 2 in the δ13C record. The evolution of P contents points to an increase in the input of this nutrient at the onset of OAE 2. The trends in RSTE contents show, however, that this part of the Helvetic realm was not affected by a strong depletion in oxygen conditions during OAE 2, despite its hemipelagic position. A further goal of this project was to submit the samples to a total extraction method (a combined HF/HNO3/HCI acid digestion) and compare the results obtained by the partial HNO3 acid extraction in order to standardize the analytical prócedures in the extraction of RSTE. The obtained results for samples of OAE 1 a suggest that RSTE trends using the partial HNO3 digestion are very comparable to those obtained by the total digestion method and subsequently normalized with regards to AI contents. RÉSUMÉ : Durant ce projet de thèse, financé par le Swiss National Science Funding (SNSF), j'ai étudié l'évolution des conditions redox et de la préservation de carbone organique dans le domnaine ouesttéthysien pendant trois excursions majeures du δ13C au Crétacé correspondant au Valanginien, à l'Aptien inférieur et à la limite Cénomanien-Turonien. Ces périodes sont caractérisées par des changements climatiques et environnementaux globaux associés à des perturbations dans le cylce du carbone. Pour L'excursion positive en δ13C du Valanginien, les analyses du carbone organique total (COT) et les observations palynologiques du domaine téthysien ont présenté des indications d'environnement pélagique relativementbienoxygéné. L'absence d'enrichissements en éléments traces sensibles aux conditions redox (TE) pendant l'excursion positive en δ13C confirme ces interprétations. Les données publiées de COT dans d'autres partie du globe indiquent cependant l'existence de conditions dys- à anaérobiques dans certains bassins restreints de l'Atlantique, l'Océan Austral et du Pacifique. L'évolution du phosphore (P) et la composition minéralogique des sédiments semblent indiquer un climat relativement chaud et humide avant l'excursion en δ13C entraînant une augmentation de l'altération continentale. Pendant le shift isotopique, une diminution des apports détritiques et du P suggèrent une transition vers des conditions plus arides. À l'Aptien Inférieur, le début de l'événement anoxique (OAE 1a) est marqué par une augmentation générale du P dans les sédiments indiquant une augmentation du niveau trophique à la base de l'excursion isotopique. Durant l'événement anoxique, les sédiments sont relativement appauvris en P. Cette diminution rapide associée à des enrichissements en TE est probablement liée à une remobilisation plus importante du P lors de la mise en place de conditions anoxiques dans les eaux de fond. Dans les environnements de bassin, le comportement des TE (enrichissements bien marqués) attestent de conditions réductrices bien marquées alors que dans les environnements moins profonds, les conditions semblent plutôt oxiques à dysoxiques. De plus, deux niveaux d'enrichissement en TE ont été observés dans la partie plus profonde de la Téthys, indiquant des fluctuations assez rapides dans l'intensité de l'anoxie de la colonne d'eau. Nous avons ensuite étudié les effets de l'événement anoxique de la fin du Cenomanien (OAE 2) dans un basin marginal de la marge nord de la Téthys avec la coupe de Chrummflueschlucht (à l'est de Euthal, Ct Schwyz). Les résultats ont montré que cette coupe présente un des enregistrements sédimentaires des plus complets de l'OAE 2 dans le domaine helvétique malgré un hiatus entre le pic 1 et 2 de l'excursion en δ13C. L'évolution du P montre une augmentation au début de l'OAE 2. Cependant, la distribution des TE indique que cette région n'a pas été affectée par des conditions réductrices trop importantes. Un second aspect de ce travail a été l'étude des différentes méthodes sur l'analyse de la distribution des TE. Des échantillons de l'OAE 1a ont été soumis à deux types d'extractions, l'une dite «totale » (attaque combinée d'acides HF/HNO3/HCI) et l'autre dite partielle » (HNO3). Les résultats obtenus suggèrent que les courbes de tendances des TE acquises par extraction partielle sont semblables à celle obtenues par extraction totale et normalisées par l'AI.

A methodology to event reconstruction from trace images

The widespread use of digital imaging devices for surveillance (CCTV) and entertainment (e.g., mobile phones, compact cameras) has increased the number of images recorded and opportunities to consider the images as traces or documentation of criminal activity. The forensic science literature focuses almost exclusively on technical issues and evidence assessment [1]. Earlier steps in the investigation phase have been neglected and must be considered. This article is the first comprehensive description of a methodology to event reconstruction using images. This formal methodology was conceptualised from practical experiences and applied to different contexts and case studies to test and refine it. Based on this practical analysis, we propose a systematic approach that includes a preliminary analysis followed by four main steps. These steps form a sequence for which the results from each step rely on the previous step. However, the methodology is not linear, but it is a cyclic, iterative progression for obtaining knowledge about an event. The preliminary analysis is a pre-evaluation phase, wherein potential relevance of images is assessed. In the first step, images are detected and collected as pertinent trace material; the second step involves organising and assessing their quality and informative potential. The third step includes reconstruction using clues about space, time and actions. Finally, in the fourth step, the images are evaluated and selected as evidence. These steps are described and illustrated using practical examples. The paper outlines how images elicit information about persons, objects, space, time and actions throughout the investigation process to reconstruct an event step by step. We emphasise the hypothetico-deductive reasoning framework, which demonstrates the contribution of images to generating, refining or eliminating propositions or hypotheses. This methodology provides a sound basis for extending image use as evidence and, more generally, as clues in investigation and crime reconstruction processes.

Trace element differentiation in ferruginous accumulation soil patterns under tropical rainforest of southern Cameroon, the role of climatic change

Regions under tropical rainforest cover, such as central Africa and Brazil are characterised by degradation and dismantling of old ferricrete structures. In southern Cameroon, these processes are relayed by present-day ferruginous accumulation soil facies, situated on the middle and the lower part of hill slopes. These facies become progressively harder towards the surface, containing from bottom to top, mainly kaolinite, kaolinite-goethite and Al-rich goethite-hematite, and are discontinuous to the relictic hematite-dominated ferricrete that exist in the upper part of the hill slope. These features were investigated in terms of geochemical differentiation of trace elements. It appears that, in contrast to the old ferricrete facies, the current ferruginous accumulations are enriched in transitional trace elements (V, Cr, Co, Y, Sc) and Ph, while alkali-earth elements are less differentiated. This recent chemical accumulation is controlled both by intense weathering of the granodiorite bedrock and by mobilisation of elements previously accumulated in the old ferricrete. The observed processes are clearly linked to the present-day humid climate with rising groundwater tables. They slowly replace the old ferricretes formed during Cretaceous time under more seasonal climatic conditions, representing an instructive case of continuos global change. (C) 2002 Elsevier Science B.V. All rights reserved.

Insights into shallow magmatic processes in large silicic magma bodies: the trace element record in the Fish Canyon magma body, Colorado

Highly evolved rhyolite glass plus near-solidus mineral assemblages in voluminous, dacitic, crystal-rich ignimbrites provide an opportunity to evaluate the late magmatic evolution of granodiorite batholiths. This study reports laser-ablation ICP-MS analyses of trace element concentrations in feldspars, hornblende, biotite, titanite, zircon, magnetite, and interstitial glass of the crystal-rich Fish Canyon Tuff. The high-silica rhyolite glass is characterized by relatively high concentrations of feldspar-compatible elements (e.g., 100 ppm Sr and 500 ppm Ba) and low concentrations of Y (< 7 ppm) and HREE (&SIM; 1 ppm Yb), hence high LREE/HREE (Ce/Yb > 40) compared to many well-studied high-silica rhyolite glasses and whole-rock compositions. Most minerals record some trace element heterogeneities, with, in particular, one large hornblende phenocryst showing four- to six-fold core-to-rim increases in Sr and Ba coupled with a decrease in Sc. The depletions of Y and HREE in the Fish Canyon glass relative to the whole-rock composition (concentrations in glass &SIM; 30% of those in whole rocks) reflect late crystallization of phases wherein these elements were compatible. As garnet is not stable at the low-P conditions at which the Fish Canyon magma crystallized, we show that a combination of modally abundant hornblende (&SIM; 4%) + titanite (&SIM; 0.5-1%) and the highly polymerized nature of the rhyolitic liquid led to Y and HREE depletions in melt. Relatively high Sr and Ba contents in glass and rimward Sr and Ba increases in euhedral, concentrically zoned hornblende suggest partial feldspar dissolution and a late release of these elements to the melt as hornblende was crystallizing, in agreement with textural evidence for feldspar (and quartz) resorption. Both observations are consistent with thermal rejuvenation of the magma body prior to eruption, during which the proportion of melt increased via feldspar and quartz dissolution, even as hydrous and accessory phases were crystallizing. Sr/Y in Fish Canyon glass (13-18) is lower than the typical ``adakitic'' value (> 40), confirming that high Sr/Y is a reliable indicator of high-pressure magma generation and/or differentiation wherein garnet is implicated.

Major, minor, trace element, Sm-Nd and Sr isotope compositions of mafic rocks from the earliest oceanic crust of the Alpine Tethys

Recent isotopic and biochronologic dating has demonstrated that the Gets nappe contains remnants of the oldest part of the oceanic crust of the Alpine Tethys. The ophiolites are associated with deep sea sediments, platform carbonates and continental crustal elements suggesting a transitional environment between continental and oceanic crust. Therefore, the ophiolites from the Gets nappe provide the opportunity to assess the nature of mantle source and the magma evolution during the final rifting stage of the European lithosphere. Trace clement analyses of mafic rocks can he divided into two sets: (1) P, Zr and Y contents are consistent with those of mid-ocean ridge basalts and REE patterns have a P-MORB affinity. (2) P,Zr Ti and Y contents are compatible with within-plate basalts and are characterized by REE spectra similar to that of T-MORB. Both have Nd isotopic compositions similar to those of synrift magma of the Red Sea and to the Rhine Graben. The model ages are in agreement with an LREE-enriched subcontinental mantle source derived from depleted mantle 800 to 900 Ma ago. Minor, trace element and Sm-Nd compositions suggest that these rocks are basaltic relies of an earliest stage of oceanic spreading i.e. an embryonic ocean. Comparison between REE patterns, Nd and Sr isotope compositions, isotopic and biochronologic ages from different Alpine Tethys ophiolites shows that samples with enriched LREE are from the older ophiolitic suites and are relies of the embryonic ocean floor. Later phases of ocean spreading are characterized by basalts that are depleted in LREE.

Viri, Remote execution of Python scripts

Viri is a system for automatic distribution and execution of Python code on remote machines. This is especially useful when dealing with a large group of hosts.With Viri, Sysadmins can write their own scripts, and easily distribute and execute them on any number of remote machines. Depending on the number of computers to administrate, Viri can save thousands of hours, that Sysadmins would spend transferring files, logging into remote hosts, and waiting for the scripts to finish. Viri automates the whole process.Viri can also be useful for remotely managing host settings. It should work together with an application where the information about hosts would be maintained. This information can include cron tasks, firewall rules, backup settings,... After a simple Integration of this application with your Viri infrastructure, you can change any settings in the application, and see how it gets applied on the target host automatically.

Traçologie: la trace, vecteur fondamental de la police scientifique

Les développements technologiques et la spécialisation des laboratoires de police scientifique et de science forensique éloignent de plus en plus les spécialistes de leur objet d'étude: la trace comme vestige, avec toutes les difficultés associées à son caractère unique, non contrôlé qui lui donnent la dimension d'une recherche historique plus qu'expérimentale. Pour paraphraser Kirk (Kirk 1963), la discipline qui touche à l'exploitation des traces fait appel à une pléthore de moyens techniques, mais manque cruellement de recherches et de développements fondamentaux. Cela se reflète d'ailleurs dans l'absence de rigueur quant au vocabulaire utilisé et une confusion dans la nomenclature, par exemple entre l'empreinte (référent) et la trace, l'échantillon (statistiquement sélectionné) et le spécimen, l'analyse, qui n'est pas que chimique, la contamination et la pollution. Ce manque de rigueur traverse la littérature scientifique et cet essai vise à clarifier la terminologie et à proposer un emploi sémantique strict du vocabulaire et des notions de base qui touchent aux fondements de la discipline.