Dr Danilo Oliveira De Souza

Jean-Sébastien Girardon

Dr David J Hoffmann

Dr Elise Berrier

Jean-Sébastien Girardon

Dr J.-S Girardon

Dynamics of Citrate Coordination on Gold Nanoparticles Under Low Specific Power Laser-Induced Heating

à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

Nowadays, Surface Enhanced Raman Scattering (SERS) is well accepted as a powerful analytical technique, mainly due to the unique plasmonic properties of metal nanoparticles (NPs). 1 The basic components involved in this phenomenon are a molecule, a metal nanostructure and electromagnetic radiation, which introduces complexity in the interpretation of observed SERS spectra. [START_REF] Aroca | Surface-Enhanced Vibrational Spectroscopy[END_REF][START_REF] Aroca | [END_REF][4] Particularly, the interaction of incident radiation with adsorbed molecules may lead to photodissociation, photoreactions or photodesorption of those molecules deposed on the metallic surface of the nanostructure. Such effects are more pronounced, and of a special interest, when dealing with single molecule studies or ultra-sensitive SERS measurements. For instance, direct observation of heterogeneous photochemical reactions was reported based on the fluctuations in amino acid time-resolved SERS. 5 In that case, the authors were interested in the photochemical formation of amorphous carbon from aromatic precursors on Ag nanoparticles. Indeed, it is quite reasonable to suppose that depending on laser incidence and the arrangement of the nanoparticles (aggregations), the high electromagnetic fields induced on the hotspots could trigger photochemical processes. The classical example of this effect is the formation of graphitic or amorphous carbon by heating, giving rise to sp 2 stretching that appear as peaks around 1340 and 1580 cm -1 in Raman spectrum. [6][7][8] Many studies have been dedicated to understanding some aspect of the photochemical reactions, seeking to correlate it with hot electrons that arise from plasmonic effect or some other thermal charge transfer mechanism, [9][10][11] but there is no final consensus. 12,13 Essentially, hot electrons are produced upon resonant optical excitation of surface plasmons, becoming available to participate in photochemical reactions. The details on the generation of such hot electrons as well as the influence of molecular adsorbates and the representative processes are reviewed elsewhere. 12 Further, using molecular dynamics simulation, some works have inspected the light-induced heating of nanoparticles in molecular level and its propagation to the medium depending on the capping layer, which can cause molecular relaxation of the polymer coating, 14 and when increasing polymer density. 15 Other studies have performed numerical simulations to map the temperature distribution in nanoscale around nanoparticle networks [16][17][18] and the thermal processes of the light-to-heat conversion were reviewed theoretically and experimentally. 19 Another aspect related to laser illumination of capped noble metal nanoparticles is the fluctuation SERS signal in time-dependent studies. The detailed origin of such behavior has been discussed in the last years and it is suggested that is arises from thermally activated diffusion of molecules bonded to the nanoparticle surface, 20 even though many physical and chemical processes take place at the same time adding complexities in its interpretation. 21 Particularly, those works related the presence of as-called "spurious SERS spectra" that were not related in principle to the studied analyte deposited on the metal surface. 20,22 It was observed that even low-energy thermal processes can lead to reversible ionization at SERS-active sites, thus not related with an eventual photodecomposition. 20 Actually, thermal photochemistry reactions should not happen at low laser power, which it does not mean that other photoinduced effects are not present during a laser illumination, particularly if in resonance condition. [23][24][25] Fluctuations in the intensity of SER lines, wiggles and popping up of extra lines are not random and may raise upon laser illumination without trigging thermal-reactions, as already reported for silver nanoparticles. 26,27 Fluctuations on the Raman bands were reported on carbon clusters deposited on rough metal substrates using weak laser power (5 mW/cm 2 at the sample). 8,28 Of a special interest, it is noteworthy to say that the fluctuations occurred only in presence of oxygen, indicating a photooxidation process and CO molecule adsorption at the metal. 8 In this picture, even if great advances in understanding the interaction of capping layers and the nanoparticles have been done, it seems elusive to get further insights on the binding modes of citrate on the gold surface as well as the existence of possible photoreaction products of citrate at a single-particle level.

Here, we perform low-intensity laser power high resolution time-resolved SERS measurements in prelocalized surface plasmon resonance (LSPR) condition and we discuss intensity fluctuation in SERS spectrum in terms laser induced heating of nanoparticle in a non-destructive condition, i. e., without trigger photochemical reactions within nanoparticle's capping layer. We present a quantitative and qualitative investigation of the individual events occurring in time using a methodology we developed earlier and described elsewhere 29 to verify the influence of lighting on the capping layer of the nanoparticles as well as an eventual changing on the sensibility of SERS detection. In particular, we focus on the fluctuations on the COO -and CC stretch vibrations detected, respectively, in the 1500-1620 cm -1 and 950-1050 cm -1 ranges. We correlate these features with the fluctuations of different bond modes of the citrate to the nanoparticles along laser illumination.

Experimental Methods

Gold nanoparticles were synthesized via classic citrate reduction (aka, Turkevich method) described elsewhere.30 Briefly, 12.5 mL of HAuCl4 (5.4 mmol L-1) was added to 213 mL of milli-Q water and stirred at 75 °C. The temperature was subsequently increased until the temperature reached 80 °C. 25.0 mL of sodium citrate (5.4 mmol L-1) was added, so that the value of the cit./Au molar ratio is 2. SER spectra were recorded using a He-Ne laser for excitation (632.8 nm), and the power at the sample of 0.04 mW (5500W/cm2), adjusted using neutral density filters. The laser beam was focused on the contour line of the coffee-ring pattern (i. e., the pattern left by the puddle of the liquid solution after it evaporates) of the sample using a 100x microscope objective (NA 0.9). The Raman signal was collected in backscattering mode using the same objective through a confocal hole of 150 μm. The scattered light was dispersed using a spectrometer equipped with a 600 mm-groove grating and analyses by a Peltier-cooled CCD (Horiba Labram HR). For a series of SERS spectra of 10 minutes, we have used an acquisition time of 20 seconds per scan, with a rest time between two consecutive spectra of 40 seconds. Measurements were performed on regions where isolated nanoparticles could be found, since large NP aggregation could imply in different LSPR spectrum and, thus prevent a pre-resonance condition. All spectra were normalized with regards to their overall area and a nonlinear baseline correction (BL) were applied.

Electrospray ionization-Mass spectrometry (ESI-MS) in positive-mode was performed before laser illumination, using the supernatant solution, which was diluted with methanol in a ratio of 1 mg/mL, then directly infused at a flow rate of 5 μL.min -1 into the ESI source. The mass spectrometer (model 9. All mass spectra were externally calibrated using NaTFA (m/z 200-2000). A resolving power, m/Δm FWHM ≅530 000, in which Δm FWHM is the full peak width at a half-maximum peak height of m/z≅400 and a mass accuracy of <3 ppm, provided the unambiguous molecular formula assignments for singly charged molecular ions. Mass accuracy is determined from mass error, defined as Error=((m/z measured -m/z theoretical )/m/z theoretical )×10 6 . The mass spectra were acquired and processed using Data Analysis software (Bruker Daltonics).

Results

Raman spectra were collected at a coffee-ring pattern obtained from a cit-AuNP drop deposited over a microscope slide and let dried under ambient conditions at room temperature. Both the selected laser power and the acquisition time were deliberately kept very low to ensure that no non-reversible chemical change occur in the citrate layer. At 633 nm laser wavelength, the system is in pre-resonance condition regarding the plasmonic frequency of AuNPs. As a result, only limited sample heating is expected, although the Raman exaltation was highest.

The reference Raman spectrum of aqueous citrate is presented in Figure1 and a tentative assignment of its main features is presented in Table S1 (see supporting information). Of particular interest for our system is the study of the COO -and CC stretches vibrations (respectively, around 1550 and 990 cm -1 ) because they can tell us how the citrate is coordinated to the gold nanoparticles, as discussed by Grys et al. 31 In the case of the CC stretch region, the conventional Raman spectrum of aqueous citrate shows Raman lines at 940, 1052 and 1082 cm -1 while only SERS lines were detected at 968, 1004 and 1025 cm -1 for cit:AuNP (Figure 1). Similarly, the stretches regions of COO -mode present a blue shift with respect to ordinary acid citric. Dominant SERS modes are assigned to the bidentate coordination with the central carboxylate (red) as well as bonds from terminal carboxylates (blue). The SER spectrum of the freshly prepared cit:AuNPs coffee-ring assemblies is in line with previous reports [32][33][34][35] and suggests that the citrate is chemisorbed to the gold via the carboxylic groups. Curiously, some SERS bands (particularly, 1004, 1120, 1247, 1270 and 1365 cm -1 ) strongly indicate the presence of dicarboxyketone on the surface of AuNP (see Figure 1), which is not surprising, since this phenomenon was finely discussed before. 36 This find is further supported by our ESI-MS measurements (see below). We have investigated the evolution with time of the SER signal by following the same approach as Smith et al. 29 for refining the probability and amplitude of the occurrence of particular spectral signatures observed transiently while repeating a large number of SERS acquisitions over time. To this end, we have collected one spectrum every minute during one hour, the acquisition time for each spectrum is of 20 seconds while the sample is left in the dark (laser off) for 40 seconds.

Time-Resolved SERS

The comparison of the first (t=60 s) and last (t=3600 s) SER spectra presented in Figure S1' confirms that no degradation of the capping layer has occurred during the whole analysis. Indeed, no laser-(or heat-) induced modification that would lead to significant broadening of Raman modes and formation of carbonaceous species with typical D and G-like carbon lines was observed. 37 Usually, when destructive processes over time are accompanied by unambiguously quality deterioration, such as decreasing of peak intensities and peak broadening, 38 which would make the summed (or averaged) spectrum like the typical carbon broad-band features. 8 Instead, we observe that the relative intensity of some vibrational modes was drastically modified during the experiment as well as the rising of new lines without significant quality deterioration.

In order to re-build the chronicle of such evolution, we propose here a qualitative investigation of the time-lapsed SER features over the whole set of collected spectra. To this end, time-dependent evolution of SERS spectra is showed in Figure 2. All spectra were normalized with respect to their overall area after a baseline correction. By doing so, we remove the continuous background emission from the SER spectra as well as we assure that each individual measurement and peak is independent of the dose received from laser. Main SERS bands present during the whole process are observed at 775, 1004, 1270, 1352 and ∼1600 cm -1 . Interestingly, no remarkable changes are detected before 1920 seconds, which has been also observed for other sets of experiments, i. e., a measure made with the same parameters, on the same sample, but in a different region (Figure S1''), suggesting that the generation of such fluctuations is an activated process. In the second part of the experiment (from 1900 s), we clearly point individual events on the spectral evolution. Indeed, not only variations in the relative intensity of lines are detected, but also frequency shifts and/or transient occurrence of new lines. The instant a on the figure marks the first remarkable event on our experiment (at t=1980 s), an important increase in the intensity of the broad line centered at 1595 cm -1 , which hold its value during 2 consecutive spectra (or 120 s, in total). As soon as the intensity fluctuation ends and the intensity backs down to an ordinary value, we observe a second (shorter) one, now at 1565 cm -1 followed by simultaneous blinks at 1500 and 1130 cm -1 (mark b, in Figure 2, t=1980 s). Mark c (t=2880 s) points to another blink in the same (but sharper, this time) region centered at 1595 cm -1 , whereas the mark d (t=3240 s) is characterized by multiple concomitant events, namely, the rise of the Raman line at 1025 cm -1 followed by a slight wiggling, the increased intensity of the 1270 cm -1 line and the shift to higher position of the peak centered at 1595 cm -1 .

In order to quantify properly an eventual correlation between lines and fully portrait the species present, we provide in the following a 2D correlation picture showing the covariance map of the dataset.

Analysis of Covariance Between SER Lines

The adopted approach [START_REF] Noda | Two-Dimensional Correlation Spectroscopy -Applications in Vibrational and Optical Spectroscopy[END_REF] consists in compare quantitatively the variation in spectral intensity over the time of the experiment (t) considering two different wavenumbers, said ν n and ν m and calculating their covariance value, X(ν n , ν m ):

(1) and represents the coincidental trends (or dissimilarities) of intensities from two different wavenumbers as t is scanned. The symbol <…> denotes for a cross-correlation function. The so-called synchronous 2D correlation map, in a set of discrete dynamic spectra measured at equally k spaced points, can be calculated in a way very similar to the statistical covariance of the spectral intensity with k -1 degree of freedom, as follows:

(2)

Where

is the spectrum at time equals to t j subtracted from a reference spectrum, usually the averaged one. Our synchronous 2D correlation map is shown in Figure 3. Typical from these constructions, one observes a symmetry with respect to a diagonal line corresponding to coordinates ν n =ν m , with correlation peaks appearing at both diagonal and off-diagonal positions. Negative correlation values give purple traces whereas positive values are gradually represented by light blue to red regions (see color scale on the right). Any region of a spectrum which changes intensity to a great extent under a given perturbation will show strong autopeaks (the diagonal peaks), while those remaining near constants develop little or no autopeaks. For instance, Figure 3 tells us that the peak centered at 775 cm-1 (the A spot) has a dull autopeak as consequence of its stable intensity during the whole experiment. Equally, those evident lines seen in Figure 2 (1004, 1247, 1348, 1362 and 1485 cm-1) present no autopeaks, except 1270 cm-1 (which corresponds to autopeak D). The strongest autopeaks are marked with capital letters, from B to F. Peak B, centered at 1025 cm-1 has strong positive correlation with peaks D (1270 cm-1) and F (∼1587 cm-1), but just weak with respect to E autopeak (∼1500 cm-1). On the other hand, feature C (1130 cm-1) seems to have no clear positive correlation with any other spectral feature. Actually, there are other spots on the 2D plot that behave on the same way, however they can be barely seen because they do not present strong autopeaks. Feature A is one of them, together with weak spots at 680, 863, 915, 1190 and 1420 cm-1. It is easily verifiable that autopeak A comes from a SERS peak with stable intensity. Besides it, for the other bands the reason is they are just flash signals along the experiment and may be considered as individual events (see Figure S2', where these events could be highlighted after perform a subtraction of each spectrum by the first component taken from Principal Component Analysis).

So far, it seems the system evolves to a final stage in which a further contribution appears after isolate and transient events. On next, we go deeper on the analysis to isolate the concomitant events, then give them a proper hypothesis.

Individual Events Analysis

In order to isolate these individual events, we performed temporal profile analysis of the intensity of selected lines (Figure 4A). The criterion to be considered as an individual event is described as following:

the averaged intensity (Avg) and the standard deviation (σ) were evaluated. Individual events were defined as the events showing at least an intensity value as high as the threshold of Avg+3σ. Such flash events on the spectra, can be checked also by means of the excess Kurtosis coefficient defined for each Raman shift over time as:

(3) where μ 4 is the fourth moment about the mean and σ is the standard deviation. The Kurtosis plot has the ability to show us particular lines on a SER spectrum that contain an outlier (a flash event, in our case) either due to a high degree of abnormality of the intensity or due to a significant contribution of a new signal.

Figure 4B shows the Kurtosis coefficients as a function of the Raman shift for our experiment. It reveals that individual events happen in a wide range of the spectrum along the laser exposure. Considering the threshold of 3σ (three times the standard deviation), we have outliers in our series at 863, 1016, 1025, 1132 cm -1 and the wide region ranging from 1550 to 1620 cm -1 . Some of the bands coincide with those found on 2D plot of Figure 3. Even though the band at 1420 cm -1 is absent in Kurtosis plot, its intensity profile vs. time (Figure 4A) does suggest an individual event (also supported by Figure S2'). It seems that the smooth increasing of its intensity along the time (Figure 4A) was enough to put down its Kurtosis coefficient. Further, one observes that 1016 cm -1 and 1025 cm -1 points at Kurtosis plot correspond actually to the same feature at the time evolution of Figure 1 that arises at t=3240 s and slightly wiggle until the end of the experiment.

Since the time lapse of one of our SER spectra is far bigger (by several orders of magnitude) than the time characteristic lifetime of intermediate chemical species, we interpret these features in the context of single molecule detection. A selection of SER spectra corresponding to these individual events is presented in Figure S3' and Figure S4' shows the intensity along the time. All new peaks or peak blinks emerge from 1980 seconds on, which is our first mark point on the time-resolved plot on Figure 2 (the horizontal line with label a). It seems that some of the events are undoubtably linked and we will discuss them based on recent studies related to the citrate coordination and bridging modes to nanoparticles. 25,31 In the beginning, vibration bands such as 632, 848, 940 and 1591 cm -1 suggest that citrate molecules attached to the gold nanoparticles has a coordination mode in which at least one or two carboxylates are non-bound to the gold (see Table S1). This coordination is quite stable up to t=1920 s. Then, our system starts to suffer modifications. Based DFT calculations performed by Grys et al., 31 it was found seven possible coordination modes that citrate can be fitted when trapped between two gold nanoparticles (some of these modes are drawn on SI, see Figure S6'). Accordingly, we can associate those individual events from Figure S3' and Kurtosis analysis to one or two of the modes found on calculations. For instance, the vibration at 863 cm -1 may be associated to the modes c 2 -t 2 or c 2 -t 2 t 2 . The band at 915 cm -1 may be due to the c 2 t 2 -t 2 mode as also the c 2 mode. 1138 cm -1 vibration (and also 1132 cm -1 ) can be linked to c 2 -t 2 or t 2 t 2 modes, while the ones at 1151 and 1171 cm -1 can be connected to the c 2 -t 2 mode. The band at 1420 cm -1 is present at the c 2 -t 2 mode as well as c 2 or t 2 . Finally, 1560 cm -1 arises in c 2 -t 2 mode or c 2 . It is worth to note that among the calculated DFT modes, in three (c 2 -t 2 , c 2 -t 2 t 2 , c 2 t 2 -t 2 ) we have central and terminal carboxylates bound in adjacent nanoparticles, spanning the citrate on the Au surface. The condition to such situation is to have low surface coverage to allow the span a small gap between the neighbor nanoparticles. 31 Even though in literature Raman lines 680, 863, 1150, 1170, 1220 and 1540 cm -1 are reported as being due to CO, H 2 O 2 , O 2 or HO 2 -adsorption on gold surface, [START_REF] Maynard | [END_REF][41][42][43][44][45][46] our recorded spectra are out of range for a suitable analysis of these hypothesis. For instance, it is actually on the range 1800-2100 cm -1 one can accurately observe the CO contribution. 47 Thus, we cannot exclude this possibility, but we have no further evidence that these adsorption processes may occur undoubtedly in our experiment.

Particularly, the CC-stretches in combination with the asymmetric COO-stretches, found on the region from 1580-1620 cm -1 deserves a special attention because it is the zone where the citrate bridges to the gold nanoparticles. Thus, the vibrations there in are enough to differentiate these modes in a SER spectrum. 31 Thus, we performed accurate analysis of this region along the last instant of our experiment, since it is where the system passes by an intense variation as seen in Figure 2 and as suggested by the Kurtosis coefficients (Figure 4B). Figure 5 shows in more details the region of interest in the time range t=2700-3600 s. The first abrupt change in intensity happens for the peak around 1590 cm -1 at t=2820 s.

During the lapse of 3 scans, it remains at the same position for (blue curves), then disappear for 4 scans (grey curves) to then reappear blue-shifted and evolves slightly across high frequencies (green curves).

This reappearance comes together with the arise of a new band around 1605 cm -1 . A similar trend concerning its centroid position is clearer when observing the plot of results for the peak fitting (Figure 5A, right panel; the color zones follow those from the left panel). Also, from the fit, one observes that the areas of the peaks tend to remain constant (with neither significant variation of the FWHM values), if we ignore (for obviously reasons) the brief time when the peak around 1590 cm -1 disappears (the grey area).

Thus, one can say that there is an actual blue shift of the two main peaks in these regions (black and red dots). A similar analysis (Figure S5') is performed in the region from 980-1050 cm -1 , where it is observed the wiggle band (∼1025 cm -1 ) at the end of the experiment (from t=3180 s). (see Table S1 andS2), as confirmed by Mass Spectrometry (below). The further modifications of the spectra are attributed mainly to the reconfiguration of citrate (see Table S1).

Mass Spectrometry Analysis of cit-AuNP Solution

We carried out ESI-MS to check if before the experiment any byproduct of citrate reaction was produced during the synthesis. Figure 6 shows us the full scan ESI-MS in the range m/z=200-1100. The build-block of our system, aka citrate radical, has m/z=191 and it is out of our range of measurement. However, we can recognize a lot of structures that are closed linked to it, particularly bounded to a gold atom. Actually, ESI-MS is known to produce fragmentation (by collision dissociation) and to form dimers such as [2 M+H] + or [2 M+Na] + when analyte concentration is increased. [START_REF] Pramanik | Applied Electrospray Mass Spectrometry[END_REF][START_REF] Kind | [END_REF][50][51][52] We kept our attention to the molecular formulas containing the molecular building blocks of the measured ligand (for example, C 6 and O 7 and their multiples for citrate) with a matching isotope pattern ( 12/13 C plus the corresponding heteroatoms of the calculated molecular formulae), but eventually we found also contributions from fragmented complexes, such as dicarboxy acetone (DCA), in very low concentration (as viewed by the relative peak height, named, 365 and 563) or almost insignificant. The fragments are assigned in grey in Figure 6 and the list of the possible candidates are written in Table S3.

DCA is a well-known product from synthesis that may be present as capping AuNP or as a supernatant. 53 It is worth to note that ESI-MS points to an excess of Na + ions attached to the citrate, which is a condition that favors shorter distance among the gold nanoparticles, enabling the appearance of the c 2 -t 2 t 2 SERS modes. 31 The temporal evolution experienced by our system suggests that citrate anions undergo temperature-dependent conformational changes. Thus, we hypothesize that our system suffers a photoinduced coordination transformation from single citrate molecules bounded to gold atoms (c 2 , t 2 vibrational modes) to single citrate molecules being coordinate by different Au atoms (c 2 -t 2 t 2 , c 2 -t 2 and c 2 t 2 -t 2 ). These changes could happen locally on the hotspots between two nanoparticles as a result of, for instance, the evaporation of the residual water eventually present on our sample during SERS experiment.

Such evaporation caused by the heat transfer could allow the nanoparticles to relax and decrease the gap among them, stablishing a new local arrangement concerning citrate coordination. Further, this transformed disposition would induce the formation of additional hot spots (or increased SERS enhanced factors), making detection of previously present low-concentrated byproducts or fragments easier and more evident, particularly, DCA molecules. Indeed, a photoinduced system evolution leading to amplification of detection for similar systems has been already reported and discussed in literature. 31,54

Conclusions

We have shown that even under very low-power laser illumination, the citrate cap layer of gold nanoparticles synthesized by classic citrate reduction undergo a net transformation as seen by relative long-term time-resolved SERS experiments. We have demonstrated that it is possible to refine the citrategold bond modes by using the Kurtosis descriptor, the time-evolution of reaction product characteristic lines and the covariance values in a complementary manner. We have given a step forward in the using of such methodological method of analysis, not only applied to chemical reactions but now to local and subtle coordination changes that can lead to increased enhancement SERS amplification. Accordingly, our hypothesis is that laser induced a local surface reconfiguration without trigger any chemical reaction that changed the coordination between citrate and adjacent nanoparticles. Individual events could be due to a transient SERRS phenomenon allowed by the thermally activated formation of particular local resonant structures via charge-transfer processes. As consequence, besides the citrate capping the nanoparticles, we could increase the sensibility to extreme low concentrated fragments that were eventually present on the hotspots, such as dicarboxy acetone.

Supporting Information Summary

 Assignment of Raman and SER bands  Tentative of assignment of SERS/Raman bands (Table S1)  SERS bands for Citrate byproducts (Table S2) S3)  Additional references cited within the Supporting Information. [55][56][57][58]





4 T

 4 Solarix; Bruker Daltonics, Bremen, Germany) was set to operate over a mass range of 200-2000m/z. The ESI source conditions were as follows: nebulizer gas pressure of 1.5 bar, capillary voltage of -3.6 kV, and transfer capillary temperature of 200 °C. Ions time accumulation was 0.060 s and the FT-ICR mass spectra were acquired by accumulating 16 scans of time-domain transient signals in 512k time-domain data sets.

Figure 1 :

 1 Figure 1: Citric acid Raman vs. citrate-capped Gold Nanoparticles SERS. Blue or red highlights on the spectra are related to coordination of a particular carboxylate position, respectively, terminal or central. Symbols (*) represent the bands that can be assigned to dicarboxyketone.

Figure 2 :

 2 Figure 2: Time-resolved spectral evolution of citrate capping gold nanoparticles illuminated with a laser power of 0.04 mW. Each row represents one color-coded spectrum with time running from bottom to up. Solid white lines mark particular events (see text).

Figure 3 : 1 .

 31 Figure 3: Synchronous 2D Raman plot. Reference spectrum at the top and right of the contour map is the average spectrum. Capital letters highlight some of the main autopeaks on the analysis. A to F corresponds respectively to the peaks/regions centered around 775, 1025, 1130, 1270, 1500 and 1587 cm -1 .

Figure 4 :

 4 Figure 4: A) SERS intensities of selected bands as function of time highlighting the flash behavior. Average values for each series together with the defined threshold (see text) are also plotted for reference; vertical bars are guide for the eyes, showing the point of maximum. B) Kurtosis values as a function of wavenumber for the whole data set.

Figure 5 : 1 ;

 51 Figure 5: A) SER spectra from 2700 s up to 3600 s on the 1550-1640 cm -1 ; the dashed lines are guide for the eyes. B) Centroid and Total Area evolution obtained after the fit of individual spectra.

Figure 6 :

 6 Figure 6: Full scan ESI mass spectrometry of citrate-AuNP recorded in positive ion mode. (C 6 H 5 O 7 )3-is the molecular building block, named "Cit". m/z is the mass-over-charge ratio of the detected compounds.



  First and last spectra after 1 h irradiation (Figure S1') Evolution of SERS in a different spot of the sample (Figure S1'')



  Analysis of Individual Events  Difference contour plot of SER spectra by PC 1 (Figure S2'  SER spectra corresponding to the events of Figure S1 (Figure S3') Intensities in function of time of extra bands (Figure S4') Close analysis of the 1025 cm -1 band from t=3180 s (Figure S5')  Mass Spectrometry cit-AuNP solution  Tentative of assignment of ESI-MS lines (Table

  Citrate Coordination Modes of Gold Nanoparticles  Selected Coordination Modes as Calculated by DFT (Figure S6')

Acknowledgments

We are enormously thankful to the Prof. Dr. Jeremy J. Baumberg from The Cavendish Laboratory -Department of Physics of University of Cambridge, for gently share data of DFT simulations and SERS/Raman from citrate thermo-decomposition products. The authors thanks also Prof. Dr. Wanderson Romão, from Chemistry Department -Federal University of the Espirito Santo (UFES) for the ESI-MS measurements and the CNPq (Centro Nacional de Pesquisa Científica, Brazil) for financial support of David J. Hoffmann (In memoriam).


Paola Artero

Adriana Şerban

The Status of Qualitative and Quantitative Methods of Enquiry in Translation Research: C. S. Lewis's Narnia in French -A Corpus-based Approach

Introduction

In this paper, we give a succinct outline of the role of corpora in the contemporary discipline of Translation Studies (TS), discuss the status of qualitative and quantitative methods of enquiry in translation research, and present an ongoing corpus-based project which combines qualitative and quantitative methods. The English source texts (henceforth STs) and their French translations (TTs, from target texts) are being converted into machine-readable form and will be analysed with the software WordSmith Tools in view of establishing frequencies of occurrence of a number of linguistic features deemed relevant to the expression of ideology and point of view. The toolkit for comparative analysis includes, at this stage of the project, the following phenomena: deixis, transitivity, modality, presupposition and junction, as well as lexical choice and politeness considerations. Fine-grained, contextualised analyses will complement quantitative methods in order to help interpret statistical data (not available yet at the time of writing) and enable us to draw inferences about the translators's mediating intervention.

Corpora in translation and interpreting research

The term 'corpus' is sometimes used loosely, referring to virtually any set of oral or written texts or excerpts from texts a researcher has chosen to illustrate the points she wants to make. While the Latin word corpus -body -does not preclude using 'corpus' for a variety of collections of texts, it does carry connotations of coherence and completeness. Thus, in Corpus Linguistics the term is reserved for bodies of texts created according to well-specified design criteria which match one or several research objectives and offer a safeguard against arbitrariness and circularity. In other words, in addition to providing large amounts of real-life data and enabling certain generalisations to be made, corpus methodology puts the scholar beyond potential accusations of having chosen her data in such a way that it suits her argument and that, inevitably, what was discovered is what the researcher set out to find in the first place.

In what follows, we outline the developments in the discipline which opened the way, a few decades ago, for corpus-based work in translation and interpreting. We then discuss types of corpora and associated research questions.

Descriptive Translation Studies (DTS)

Holmes's (1972) essay "The Name and Nature of Translation Studies", which remained an unpublished manuscript for a long time, and Toury's (1980) In Search of a Theory of Translation, which later led to Descriptive Translation Studies -and Beyond (1995), are generally seen as founding texts in contemporary Translation Studies, especially in terms of the descriptive (as opposed to prescriptive) orientation the discipline was encouraged to adopt.

Toury worked on norms in translation, understood as regularities of behaviour (though there are scholars according to whom regularities of behaviour do not necessarily reflect norms), and insisted that the case study approach may not be the only method of enquiry. Something beyond isolated descriptions was felt to be needed, and this developed into a concern for carrying out systematic studies of authentic data, based on transparent and replicable methodology which would make it possible for other researchers to test the results, repeat the same protocol on other texts and pairs of languages, and to make a number of generalisations such as generalisations with respect to universal laws governing translation, irrespective of language combinations. Introspection methods were to be replaced by observation of large quantities of real-life, translated text. From here, the step towards methodology borrowed from Corpus Linguistics was a small one, although not entirely unproblematic. scholars question the illusion of objectivity and transparency empirical work seems to rely on, and to generate.

Corpora and research questions in translation 9

Corpora have been used in Translation Studies for approximately two decades. Baker (1993Baker ( , 1995[START_REF] Baker | Corpus-based Translation Studies: The Challenges that Lie Ahead[END_REF] raised awareness to the potential of corpus linguistic methodology to enrich translation research and help the discipline take a step in the direction of empirical studies, with their reputation for rigour and objectivity. A variety of research questions, corpus types and processing techniques were developed or borrowed, and the number of language combinations concerned has grown exponentially over the years (see the overviews in [START_REF] Laviosa | Corpus-based Translation Studies: Theory, Findings, Applications[END_REF][START_REF] Olohan | Routledge. The Status of Qualitative and Quantitative Methods of Enquiry in Translation[END_REF]and Zanettin, 2012; in France, where there has been substantially less corpus-based translation work, see the papers in Ballard and Pineira-Tresmontant, 2007;for interpreting, see Straniero Sergio and Falbo, 2012).

Researchers have created and analysed corpora which are computerised (e.g., [START_REF] Kenny | Lexis and Creativity in Translation: A Corpus-based Study[END_REF], Saldanha, 2005[START_REF] Bosseaux | How Does It Feel? Point of View in Translation[END_REF][START_REF] Ng | A Systemic Approach to Translating Style: A Comparative Study of Four Chinese Translations of Hemingway's The Old Man and the Sea[END_REF]) or non-computerised (e.g., McLaren, 1999[START_REF] Mason | Deixis as an Interactive Feature in Literary Translations from Romanian into English[END_REF], bilingual or multilingual, written or oral (transcribed), parallel (aligned or not) or comparable, general or specialised, complete or designed on the basis of representative samples, and can include one or several text types and genres. Some of the many research questions which have preoccupied scholars concern norms and universals of translation (such as simplification and explicitation), translator style and creativity, text strategy and audience design, as well as point of view and ideology.

In other words, Corpus-based Translation Studies (CTS) is now a well-established strand of the discipline of Translation Studies. The time is, then, ripe for (constructive) criticism and, before we outline the Narnia project, we briefly discuss some of the arguments against corpus approaches and, more generally, against empirical research in translation.

Research frameworks in Translation Studies and beyond

The question of which models -conceptual frameworks and associated methodologiesto use in translation research is linked, on the one hand, to general epistemological considerations and, on the other, to the difficulty of defining what translation is and does. There are several ways of conceptualising translation, some of them leaning towards various strands of linguistics, others towards cultural and literary studies. While it is obvious that translators work with the material of language, it is also undeniable that their actions are situated in, and influence, a wider, multidimensional context, which can and must be examined from a historical, political, sociological, psychological and anthropological perspective as well. Translation is, then, in-between not only in the sense that it ensures a passage, that it ferries or carries something across (trans-latio), bridging -and sometimes reinforcing -strictly linguistic and cultural divides, but also in terms of its essential interdisciplinarity, which appears, in turn, to be an asset and a difficult challenge to the identity of the discipline.

Irrespective of their provenance and orientation, research frameworks in Translation

Studies have strengths and limitations. We now turn our attention to some of them, with

The Status of Qualitative and Quantitative Methods of Enquiry in Translation ... Corela, HS-13 | 2013 special reference to introspective versus empirical work, the status of qualitative and quantitative methods of enquiry, and the use of case studies versus corpora.

The strengths and limitations of research models

According to Tymoczko (1998: 653), "behind the establishment of corpora, as behind the design of any experiment or research program or survey, lie intuition and human judgement". Empirical research is based on certain assumptions of Western rationalism about what the business of science should be. Objectivity and subjectivity are perceived as mutually exclusive, and priority is given to the former. Yet the perspective of the researcher, her angle of vision and subject position leave their imprint on an investigation and shape the aims, data, methods and results of the study. Any framework or model constructs the object of enquiry in its image, highlighting a small number of aspects out of a host of alternatives which would have been possible. The very choice of research questions is not neutral: why do we want to know certain things and not others?

A self-reflexive and self-critical stance, seeking to make explicit theoretical assumptions and to expose blind spots in one's methodology has become particularly important today (see the papers in Olohan, 2000 andHermans, 2002). Brownlie (2009: 79) coined the term 'Critical Descriptive Translation Studies' for approaches which seek to account for what happens in translation and at the same time in discourse(s) on translation.

Qualitative and/versus quantitative research

In his autobiography Errata, George Steiner, the celebrated author of After Babel. Aspects of Language and Translation, develops at some length his mistrust of generalisations and replicability:

Whether one shares Steiner's fascination with the unique or not, questions such as those he raises are currently debated within Translation Studies as researchers try to ascertain the role in generating knowledge of quantitative protocols vis-à-vis contextualised, qualitative analyses of linguistic and translational data. Can useful claims still be made on the basis of fine-grained examination of examples chosen by the analyst, or should preference be given to machine-readable corpus research which makes it possible to detect textual patterns and to establish representativity and generalisability? Are trends in (large scale collections of) texts more revealing than certain meaningful, isolated occurrences? How can we take into account not only the presence, but also the absence of linguistic features, where they could have appeared but did not? What can be done to minimise the risk of skewing the interpretation of the data through incomplete contextualisation and generalisations for the sake of statistical validity (Mason, 2001: 78) Undoubtedly, computerised corpora and corpus processing tools are extremely useful for locating textual features in large collections of texts and providing statistics with respect to frequencies of occurrence, thereby giving the researcher information about the scale of certain phenomena they may want to explore. But it is equally obvious at this point that one of the greatest drawbacks is decontextualisation. This is where the human analyst is needed back into the picture (see Munday's 2002 systemic model for descriptive analysis) they have never truly left -since it is also humans, with their subjectivity, aims and preferences, who design corpora and the associated processing software.

Finally, some scholars have warned against using elaborate methodologies where common sense could give the answer.

Corpora and case studies

A distinction appears to operate between corpora and case studies. Where the former carry connotations of large scale and representativity, the latter refer to isolated descriptions of individual cases and normally do not claim to extend findings beyond the study itself. The question, however, of defining what constitutes a (representative) sample where language is concerned is a fairly vexed one. How many texts to include? What must be their length? And what is a 'case'? If all of an author's writings are studied, should they be taken to represent a corpus, would the project be a case study of that particular author, or both at the same time?

We would like to submit that the distinction between a corpus and a case study approach is somewhat blurred at times. Case studies can be conducted within corpus work and, as we explain below, an entire corpus of non-negligible size can be a case.

The Narnia corpus project

The study we outline in what follows is work in progress: C. S. Lewis's The Chronicles of Narnia: Point of View and Ideology in the French Translations is a doctoral thesis currently being prepared at the University of Montpellier 3, France. Its objective is to investigate the expression of point of view and ideology in the French translated texts by comparison with the English originals of The Chronicles of Narnia, in an attempt to discover the traces of the translator's mediating presence with regard to religious and secular ideologies, children's education, and the imaginary.

Theoretical underpinnings

Translation is not a neutral, transparent process, despite often-held views to the contrary. And neither is research in, and discourse about, translation.

According to Hatim and Mason (1990: 161), "ideologies find their clearest expression in language […]. In other words, beyond the systematic linguistic choices we make, there is inevitably a prior classification of reality in ideological terms". Thought, language and ideology appear as intimately linked: "discourse is the place where language and ideology meet, and discourse analysis is the analysis of ideological dimensions of language use, and of the materialisation of language in ideology" (Wodak, 2006: 16-7). All oral and written genres are concerned, including literature (Simpson, 1993[START_REF] Dijk | Ideology: A Multidisciplinary Approach[END_REF].

Critical Discourse Analysis and also Critical Linguistics, which applies linguistic analytical methods to the criticism of text, provide useful frameworks for the study of ideology and of point of view. Narratological aspects and the technique of focalisation are key to entering a text. In Simpson's opinion, "narrative point of view is [...] the very essence of a story's style, what gives it its 'feel ' and 'colour'" (1993: 5). Point of view is the materialisation of the eye of the author, of her viewing position, and of the manner in which the author leads the reader into the fictional universe, opening the way to the characters's perceptions and thoughts, expressed through language (Bosseaux, 2007: 15). The role of the translator is to transfer, rewrite, recreate, re-present point of view in another language, and negotiate the encounter of a new readership with the text. We want to examine the ways in which new points of view and ideologies are introduced in this process.

Our project is interdisciplinary: Translation Studies and Corpus-based Translation

Studies, but also Literary Criticism, Semiotics, Discourse Analysis, Pragmatics, Stylistics and Narratology are drawn upon. Considerations of genre are important: in our case, children's literature and, in particular, the mode of fantasy.

The corpus

The seven volumes of The Chronicles of Narnia contain 110 chapters and approximately 330,000 words in the original. The French translations for the publishing house Gallimard contain 345,000 words.

We consider this collection of texts a true corpus which, to revisit the taxonomy outlined in 2.2, is specialised (children's literature) and complete (all the Narnia volumes are included), bilingual (English and French) as well as computerised and aligned, since the novels are being scanned using the optical character recognition software FreeOCR 1 and converted into machine readable form (copyright permission has been sought). They will be studied using the corpus-processing software WordSmith Tools, which helps the researcher carry out computerised stylistic analysis and comparative analysis of aligned texts.

WordSmith Tools, created by Mike Scott in 1996, comprises several components which execute different functions: WordList generates lists of words and collocations, in alphabetical or frequency order, KeyWords makes it possible to find key words in a text, and Concord is a concordancer, i.e., a tool which retrieves nodes (search words or phrases) in context and displays the result in the form of a list in which the nodes appear with their immediate surrounding co-text. WordSmith Tools has been used, for instance, by Oxford University Press's lexicographers, and by linguists and translation scholars investigating language patterns in (translated) text (see references in 2.2).

The advantage of using these tools is that a large volume of text can be processed very quickly, when it would take a long time to do the work manually.

The toolbox for analysis

Our toolbox for analysis includes, at this stage of the project: deixis, transitivity, modality, presupposition, junction, lexical choice and politeness phenomena. It will make the object of a pilot study to determine which features appear to be most relevant to the study of point of view and ideology in the translation of The Chronicles of Narnia. They will then be included in the final model for analysis.

With the help of WordSmith Tools, these features will be identified in the aligned, bilingual corpus, in order to build up lists of data, with respect to frequencies of occurrence. We will check the results manually, to avoid the risk of distortions due to misprints, for instance, or to homographs. Quantitative methods will be complemented by qualitative analysis through which we recontextualise the translators's decisionmaking processes, placing them in the wider socio-cultural, literary and aesthetic environment. Translation and publication policies will be considered.

One other reason why manual analysis is indispensable is that not all linguistic markers are equally amenable to counting. Restricting the research to those which can be easily identified by corpus-processing tools would impose unwelcome limitations on the study and lead to the exclusion of important information about ways in which point of view and ideology are expressed in translated texts.

Example of qualitative analysis: lexical choice

From what we have been able to observe at this stage of the project, the French translations remove, or at least weaken, the spiritual message of the original Narnia books, and emphasise instead the pedagogical aim of raising good young citizens. This happens, for instance, by neutralising the mystical connotation of words, as in the short excerpt below, from The Lion, the Witch and the Wardrobe. The Pevensie children meet Father Christmas: 'Some of the pictures of Father Christmas in our world make him look funny and jolly. But now that the children actually stood looking at him they didn't find it quite like that. He was so big, and so glad, and so real, that they all became quite still. They felt very glad, but also solemn. Becoming or being 'still' is translated into French in two different ways: "ils cessèrent tous de parler" and "on est grave et silencieux". "Ils cessèrent tous de parler" conveys the negative form of an action, and the word parler is neutral and lacking in the many connotations of the English "became quite still". Etymology gives us interesting clues: Old English stille, meaning 'motionless, stationary', has its origins in West Germanic *steljaz, where the root *stel-means 'fixed, not moving, standing', while the more psychological dimensions of 'quiet' and 'silent' emerged in later Old English 2 . Most of these meanings are absent in the French translation, where 'silence' itself is not even evoked at first. But in the English text we perceive immediately the image of the children remaining 'motionless' and 'silent', but also 'peaceful', 'calm' and 'serene' -all of these conveyed by 'still'. Furthermore, 'still' has sacred connotations and echoes the Bible. Below is a brief quotation from Psalm 46:10 in Latin, followed by the Authorised Version 3 and three French translations 4 characterised by a rich lexical field and a variety of choices made by the translators:

Cessate et cognoscite quoniam ego sum Deus exaltabor in gentibus exaltabor in terra. (Latin Vulgate) Be still, and know that I am God: I will be exalted among the heathen, I will be exalted in the earth. (King James Bible, 1611) Cessez, [a-t-il dit], et connaissez que je suis Dieu; je serai exalté parmi les nations, je serai exalté par toute la terre. (David Martin, 1744) Tenez-vous tranquilles, et sachez que je suis Dieu: je serai exalté parmi les nations, je serai exalté sur la terre. (John Nelson Darby, 1859/1880) Arrêtez, et sachez que je suis Dieu: je domine sur les nations, je domine sur la terre. (Louis Segond, 1910) Another word of interest to us is 'solemn', which is rendered into French in two slightly different ways. The translator, Anne-Marie Dalmais, found it necessary to add the adverb très in "très graves", to intensify the adjective. This addition reveals a feeling of something missing, a need to go deeper, although, admittedly, it could also have been motivated by the attempt to create a parallelism between "très heureux" and "très graves". 'Solemn', like the French solennel, has spiritual connotations, and both words evoke sacred rituals. The translator preferred a synonym, grave; however, she translated 'stood looking' by " contemplaient", which could be evidence of a compensation strategy. Yet, on the whole, it is possible to claim that the French translation of the excerpt is less evocative than the original with respect to spirituality, and moves away from the religious tradition the (informed) reader can perceive between the lines of C. S. Lewis's literature for children.

Example of qualitative analysis: deixis

In the excerpt below, taken from Chapter 8 of The Magician 's Nephew (1955's Nephew ( /1998)), Lewis describes the creation of Narnia. The Voice of Aslan, the Lion, gives birth to a new world, out of darkness; this evokes the well-known passage of the Book of Genesis.

We mentioned before that the author's purpose is to inspire a religious experience in his readers while never overtly mentioning religion. Here he chooses a young character, Digory, as focaliser and witness of a key moment. The readers of the ST spontaneously identify with Digory: the narrator leads them to see the scene through the child's eyes. While it starts on the same, the French translation soon tends to put more distance between the reader and the fictional universe (see similar findings in [START_REF] Mason | Deixis as an Interactive Feature in Literary Translations from Romanian into English[END_REF]. This happens initially through the different use of deictic pronouns: 'In the darkness something was happening at last. A voice had begun to sing. It was very far away and Digory found it hard to decide from what direction it was coming. Sometimes it seemed to come from all directions at once. Sometimes he almost thought it was coming out of the earth beneath them. Its lower notes were deep enough to be the voice of the earth herself. There were no words. There was hardly even a tune. But it was, beyond comparison, the most beautiful noise he had 'There were no words. There was hardly even a tune' is translated into "Il n'y avait pas de paroles. On distinguait à peine une mélodie". Although in the French text an alliteration in 'n' and 'p' mirrors the English original's alliteration in 'th', 'w' and 'n', the rhythm is different: the symmetry between the two sentences introduced in the ST by 'there' is broken, in French, by the insertion of the impersonal pronoun on. This moves the eye of the reader away from Digory to an unspecified point in the scene and an impersonal, nonspecified witness. At the same time, free indirect discourse is not used in the translation; instead, the voice of the narrator describes the extraordinary sound, and the register used is that of an adult, not a child ('the most beautiful noise' vs. "le son le plus pur").

Moreover, Digory disappears altogether as subject of the last sentence in the French excerpt above. Now the sound itself becomes the subject of the utterance ('It was so beautiful he could hardly bear it' vs. "d'une telle beauté qu'il était à peine supportable"). A little later in the translation, the distancing process is taken a step further: 'There were no clouds. The new stars and the new voices began at exactly the same time. If you had seen and heard it, as Digory did, you would have felt quite certain that it was the stars themselves which were singing, and that it was the First Voice, the deep one, which had made them appear and made them sing. (The Chronicles of Narnia: The Magician's Nephew, 1955/1998: 61) Il n'y avait pas le moindre nuage. Les étoiles et les voix avaient surgi exactement au même moment, comme si c'étaient les étoiles qui chantaient sous la direction de la Voix principale, la voix basse.' (Le Monde de Narnia : Le neveu du magicien, translated by Cécile Dutheil de la Rochère 2001Rochère /2005: 63) : 63) Here the text undergoes significant rewriting which modifies its syntax, mostly through deletions (in bold in the English excerpt above). While the ST narrator invites the reader to witness the event in her mind and with her senses, third person narration in the French translation simply relates the events. The conjunction phrase "comme si", introducing a comparison, lessens the veracity of the description; the almost firm conviction in the original text ('you would have felt quite certain') is significantly weakened.

In section 4.4 we discussed lexical choice in a short passage from The Lion, the Witch and the Wardrobe. It would be interesting to examine "la Voix principale", the translator's solution for 'First Voice' which, in Lewis's thinking, is not just 'main' or 'principal' but also first chronologically, and is a Biblical reference (see the beginning of the Gospel According to John). Or, further in the text, "phénomènes extraordinaires" and "phénomène" for 'wonders' and 'wonder': 'phenomenon' is neutral and has scientific connotations, suggesting distanced observation rather than participation in the magic of the world.

  Our study is an analysis of point of view and ideology in the most recent French translation of C. S. Lewis's The Chronicles of Narnia. The seven Narnia books were published in English between 1950 and 1956 and started being translated into a variety of languages, among which French, soon afterwards. The Gallimard full translation of The Chronicles of Narnia appeared in 2005, collecting translations of individual volumes first published in 2001 and 2002. The translators are Cécile Dutheil de la Rochère, Anne-Marie Dalmais and Philippe Morgaut.

  Thirty years later, the discipline has achieved a critical mass of research and, through success and failure, has reached a point where it is possible to look back and see what has worked in Descriptive Translation Studies and what did not, and envisage possible avenues for the future. In particular, as discussed in 3.1 below, an increasing number of The Status of Qualitative and Quantitative Methods of Enquiry in Translation ... Corela, HS-13 | 2013

  ? Is it possible to establish deliberateness and motivation in translator behavior based on The Status of Qualitative and Quantitative Methods of Enquiry in Translation ... Corela, HS-13 | 2013 text analyses, or must text-and context-based work be complemented by ethnographic research methods?

The

  Status of Qualitative and Quantitative Methods of Enquiry in Translation ... Corela, HS-13 | 2013

  [...] And Lucy felt running through her that deep shiver of gladness which you only get if you are being solemn and still. ( The Chronicles of Narnia: The Lion, the Witch and the Wardrobe, C. S. Lewis 1950/1998: 159) Les images du Père Noël, dans notre monde, lui donnent seulement l'air comique et amusant. Mais maintenant que les enfants le contemplaient effectivement, ils le trouvèrent autre. Il était si grand, il paraissait si heureux et si vrai, qu'ils cessèrent tous de parler. Ils se sentirent très heureux, mais aussi très graves. [...] Et Lucy se sentit parcourue par ce profond frisson de joie que l'on éprouve seulement quand on est grave et silencieux.' (Le Monde de Narnia : Le lion, la sorcière et l'armoire magique, translated by Anne-Marie Dalmais 2005: 174)

The

  Status of Qualitative and Quantitative Methods of Enquiry in Translation ... Corela, HS-13 | 2013

The

  Status of Qualitative and Quantitative Methods of Enquiry in Translation ... Corela, HS-13 | 2013

  The Status of Qualitative and Quantitative Methods of Enquiry in Translation ...

Corela, HS-13 | 2013

  The Status of Qualitative and Quantitative Methods of Enquiry in Translation ... Corela, HS-13 | 2013 ever heard. It was so beautiful he could hardly bear it. (The Chronicles of Narnia: TheMagician's Nephew, 1955/1998: 61) Au coeur des ténèbres, il se passait enfin quelque chose. Une voix s'éleva, une voix très lointaine dont Digory avait du mal à identifier la source. Tantôt elle semblait monter de tous les côtés en même temps, tantôt il avait l'impression qu'elle jaillissait de la terre à leurs pieds. Les notes les plus basses étaient assez profondes pour être le chant de la terre. Il n'y avait pas de paroles. On distinguait à peine une mélodie. C'était, au-delà de toute comparaison possible, le son le plus pur qu'il eût jamais entendu, d'une telle beauté qu'il était à peine supportable.' (Le Monde de Narnia : Le neveu du magicien, translated by Cécile Dutheil de laRochère 2001Rochère /2005: 63) : 63)

'I grew possessed by an intuition of the particular, of diversities so numerous that no labour of classification and enumeration could exhaust them.[…] No repetition of measurement, however closely calibrated, in whatever controlled vacuum it was carried out, could ever be perfectly the same. It would deviate by some trillionth of an inch, by a nanosecond, by the breadth of a hair -itself a teeming immensityfrom any preceding measurement. […] Did I guess that there could be no perfect facsimile of anything, that the identical word spoken twice, even in light-quick reiteration, was not and could not be the same?'(Steiner, 1997: 3)

Concluding remarks and indications for further research

Systematic analysis, in co-text and context, of linguistic features such as those discussed above is needed before we can state with confidence that an overall trend is in operation in the source and the target texts. Comparisons between the various Narnia books in French would also be extremely useful since the translations are the work of three different individuals whose points of view, reflected in their translation choices, may not coincide.

Frequency lists will give us an idea of the scale of shifts in translation we have noticed with respect to religious and secular ideology. It is true that certain isolated occurrences can be very revealing, and that strength does not always lie in numbers. It would, however, be extremely useful to know how often shifts occur, and whether there are patterns worth exploring in depth, through qualitative analysis. This is why, in our work, qualitative and quantitative methods are indissociable, since it is only through a combination of both that we can hope to reach our objectives.

Lexical choice and deixis, discussed in 4.4 and 4.5, are not the only interesting aspects worth examining. Transitivity and modality are equally relevant. While we inevitably single out textual features for the sake of analysis, it is their interaction that can give us an insight into subtly changing points of view and shifting ideologies in translating.

The Narnia corpus study is part of a larger, multilingual project on "Key Children's Texts in Translation" at the University of Montpellier 3, France, associated with the project "Key Cultural Texts in Translation", based at the University of Leicester, UK. Both projects involve the creation and analysis of electronic repositories of source texts translations we identify as key, into and out of a wide range of European and non-European languages.

BIBLIOGRAPHIE


domain: sde sde

text:
Melissa Grunst

Andrea Grunst

David Grémillet

Jérôme Fort

Avian Energetics in a Warming Arctic

come

1 Avian energetics in a warming Arctic Melissa L. Grunst a,* , Andrea S. Grunst a , David Grémillet b,c , Jérôme Fort a a Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS-La Rochelle Université, 2 Rue Olympe de Gouges, FR-17000 La Rochelle, France b CEFE, Univ Montpellier, CNRS, EPHE, IRD, Montpellier, France c Percy FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch, South Africa * mgrun002@ucr.edu

Study description:

The Arctic is warming nearly four times as rapidly as other regions of the planet, challenging the capacity of organisms to cope with shifting resources and maintain thermal balance. Tracking responses of free-living animals in dynamic environments can be challenging, but is increasingly enabled by advanced biologging approaches. We used data gathered from miniaturized bird-borne devices to demonstrate increases in energy expenditure with declining sea ice conditions and warming sea surface temperatures in a dove-sized seabird, the little auk (also named dovekie; Alle alle). This keystone species feeds on sea ice-associated copepods and inhabits large breeding colonies in the High Arctic.

Photo 1. Little auks breed at remote sites in the High Arctic, with densely aggregated breeding colonies forming on rocky, sloped terrain, creating some challenges for fieldwork. Here little auks at our Ukaleqarteq (Kap Höegh), East Greenland, study site rest on lichen-adorned rocks above nesting crevasses, with an excellent view. Far below you can see the small, brick-red cabin (bottom right) which shelters teams during field campaigns funded by the French Polar Institute IPEV, as part of a long-term monitoring program. Especially in the face of climate change, little auks face considerable variation in sea ice conditions, which affects availability of copepod prey. Note the open water-a low sea ice year. Credit: David Grémillet Photo 2. How do you track the behavior and energy use of an animal when it flies or dives out of view? We use a number of advanced biologging approaches to monitor the movement, behavior and energy expenditure of little auks as they move between the colony, foraging sites at sea, and even wintering grounds. These approaches include triaxial accelerometers (study published in Ecology), time-depth recorders, GPSs and GLSs. Here a little auk equipped with a time-depth recorder poses on a rock, with a full gular pouch indicating that it anticipates feeding its chick. To the upper right a GLS-equipped little auk takes wing, and to the left Jérôme Fort (project co-PI) releases a GLS bird.

  Photo 2. How do you track the behavior and energy use of an animal when it flies or dives out of view? We use a number of advanced biologging approaches to monitor the movement, behavior and energy expenditure of little auks as they move between the colony, foraging sites at sea, and even wintering grounds. These approaches include triaxial accelerometers (study published in Ecology), time-depth recorders, GPSs and GLSs. Here a little auk equipped with a time-depth recorder poses on a rock, with a full gular pouch indicating that it anticipates feeding its chick. To the upper right a GLS-equipped little auk takes wing, and to the left Jérôme Fort (project co-PI) releases a GLS bird. Credit: Jérôme Fort (main photo & top right) & David Grémillet (top left)