Das illustrirte Mississippithal : dargestellt in 80 nach der Natur aufgenommenen Ansichten vom Wasserfalle zu St. Anthony an bis zum Golf von Mexico (eine Entfernung von ungefähr 2300 englischen Meilen) /

Cf. Sabin 40807.

The novels and stories.

v. 1. The late Mrs. Null.--v. 2. The Squirrel Inn. The Merry Chanter.--v. 3. Rudder Grange.--v. 4. The hundredth man.--v. 5. Ardis Claverden.--v. 6. The great war syndicate. The stories of the three burglars. The knife that killed Po Hancy. Dusky philosophy.--v. 7. The house of Martha.--v. 8. Pomona's travels. Euphemia among the pelican's. The Rudder Grangers in England. Pomona's daughter.--v. 9. The adventures of Captain Horn.--v. 10. Mrs. Cliff's yacht.--v. 11. The great stone of Sardis. The water-devil.--v. 12. The girl at Cobhurst.--v. 13. The casting away of Mrs. Lecks and Mrs. Aleshine. The vizier of the two-horned Alexander.--v. 14. The associate hermits.--v. 15. Stories. [v.]1: The lady or the tiger? The discourager of hesitancy. The transferred ghost. The spectral mortgage. Every man his own letter-writer. Thar same old coon. Our story. Derelict. On the training of parents. A borrowed month. The baker of Barnbury. The watchmaker's wife.--v. 16. Stories. [v.]2: A tale of negative gravity. Asaph. The remarkable page. The Cloverfield's carriage. A story of assisted fate. My bull-calf. As one woman to another. Our fire-screen. My terminal moraine. Plain fishing.--v. 17. Stories. [v.]3: The griffin and the minor canon. Old Pipes and the dryad. The bee-man of Orn. The queen's museum. The clocks of Rondaine. Christmas before last; or, the fruit of the fragile palm. Prince Hassak's march. The battle of the third cousins. The banished king. The philopena. Amos Kilbright: his adscititious experiences. The Christmas shadrach. The bishop's ghost and the printer's baby. The philosophy of relative existences.--v. 18. Stories. [v.]4: The magic egg. "His wife's deceased sister." The widow's cruise. Captain Eli's best ear. Love before breakfast. The staying power of Sir Rohan. A piece of red calico. The Christmas wreck. My well and what came out of it. Mr. Tolman. My unwilling neighbor. Our archery club.--v. 19. Afield and afloat: The Buller-Podington compact. The romance of a mule-car. The governor-general. Old Applejoy's ghost. Struck by a boomerang. The skipper and El Capitan. "Come in, new year." A sailor's knot. The great staircase at Landover Hall. The ghosts in my toewer. The landsman's tale.--v. 20. Kate Bonnet: the romance of a pirate's daughter.--v. 21. John Gayther's garden.--v. 22. The captain's toll-gate.--v. 23. A bicycle of Cathay. With a memorial sketch of Mr. Stockton and a bibliography of his works.

Mixing Regimes in the Amundsen Basin of the Arctic Ocean

Thesis (Ph.D.)--University of Washington, 2016-06

Pressure and temperature effects on metal-to-metal charge transfer in cyano-bridged Co-III-Fe-II complexes

The effects of pressure and temperature on the energy (E-op) of the metal-to-metal charge transfer (MMCT, Fe-II --> Co-III) transition of the cyano-bridged complexes trans - [(LCoNCFe)-Co-14(CN)(5)](-) and cis-[(LCoNCFe)-Co-14(CN)(5)](-) (where L-14 = 6-methyl-1,4,8,11-tetraazacyclotetradecan-6-amine) were examined. The changes in the redox potentials of the cobalt and iron metal centres with pressure and temperature were also examined and the results interpreted with Marcus Hush theory. The observed redox reaction volumes can mainly be accounted for in terms of localised electrostriction effects. The shifts in E-op due to both pressure and temperature were found to be less than the shifts in the energy difference (E degrees) between the Co-III-Fe-II and Co-II-Fe-III redox isomers. The pressure and temperature dependence of the reorganisational energy, as well as contributions arising from the different spin states of Co-II, are discussed in order to account for this trend. To study the effect of pressure on Co-III electronic absorption bands, a new cyano-bridged complex, trans - [(LCoNCCo)-Co-14(CN)(5)], was prepared and characterised spectroscopically and structurally. X-Ray crystallography revealed this complex to be isostructural with trans -[(LCoNCFe)-Co-14(CN)(5)] center dot 5H(2)O.

Synthetic, EPR spectroscopic, magnetic and X-ray crystallographic structural studies on copper(II) complexes of the tridentate N2S donor ligand formed from 6-methyl-2-formylpyridine and S-methyldithiocarbazate (Hmpsme)

New copper(II) complexes of general empirical formula, Cu(mpsme)X center dot xCH(3)COCH(3) (mpsme = anionic form of the 6-methyl-2-formylpyridine Schiff base of S-methyldithiocarbazate; X = Cl, N-3, NCS, NO3; x = 0, 0.5) have been synthesized and characterized by IR, electronic, EPR and susceptibility measurements. Room temperature mu(eff) values for the complexes are in the range 1.75-2.1 mu(beta) typical of uncoupled or weakly coupled Cu(II) centres. The EPR spectra of the [Cu(mpsme)X] (X = Cl, N-3, NO3, NCS) complexes reveal a tetragonally distorted coordination sphere around the mononuclear Cu(II) centre. We have exploited second derivative EPR spectra in conjunction with Fourier filtering (sine bell and Hamming functions) to extract all of the nitrogen hyperfine coupling matrices. While the X-ray crystallography of [Cu(mpsme)NCS] reveals a linear polymer in which the thiocyanate anion bridges the two copper(II) ions, the EPR spectra in solution are typical of a magnetically isolated monomeric Cu(II) centres indicating dissociation of the polymeric chain in solution. The structures of the free ligand, Hmpsme and the {[Cu(mpsme)NO3] center dot 0.5CH(3)COCH(3)}(2) and [Cu(mpsme)NCS](n) complexes have been determined by X-ray diffraction. The {[Cu(mpsme)NO3]0.5CH(3)COCH(3)}(2) complex is a centrosymmetric dimer in which each copper atom adopts a five-coordinate distorted square-pyramidal geometry with an N2OS2 coordination environment, the Schiff base coordinating as a uninegatively charged tridentate ligand chelating through the pyridine and azomethine nitrogen atoms and the thiolate, an oxygen atom of a unidentate nitrato ligand and a bridging sulfur atom from the second ligand completing the coordination sphere. The [Cu(mpsme)(NCS)](n) complex has a novel staircase-like one dimensional polymeric structure in which the NCS- ligands bridge two adjacent copper(II) ions asymmetrically in an end-to-end fashion providing its nitrogen atom to one copper and the sulfur atom to the other. (c) 2005 Elsevier B.V. All rights reserved.

Binocular summation at contrast threshold:a new look

Contrast sensitivity is better with two eyes than one. The standard view is that thresholds are about 1.4 (v2) times better with two eyes, and that this arises from monocular responses that, near threshold, are proportional to the square of contrast, followed by binocular summation of the two monocular signals. However, estimates of the threshold ratio in the literature vary from about 1.2 to 1.9, and many early studies had methodological weaknesses. We collected extensive new data, and applied a general model of binocular summation to interpret the threshold ratio. We used horizontal gratings (0.25 - 4 cycles deg-1) flickering sinusoidally (1 - 16 Hz), presented to one or both eyes through frame-alternating ferroelectric goggles with negligible cross-talk, and used a 2AFC staircase method to estimate contrast thresholds and psychometric slopes. Four naive observers completed 20 000 trials each, and their mean threshold ratios were 1.63, 1.69, 1.71, 1.81 - grand mean 1.71 - well above the classical v2. Mean ratios tended to be slightly lower (~1.60) at low spatial or high temporal frequencies. We modelled contrast detection very simply by assuming a single binocular mechanism whose response is proportional to (Lm + Rm) p, followed by fixed additive noise, where L,R are contrasts in the left and right eyes, and m, p are constants. Contrast-gain-control effects were assumed to be negligible near threshold. On this model the threshold ratio is 2(?1/m), implying that m=1.3 on average, while the Weibull psychometric slope (median 3.28) equals 1.247mp, yielding p=2.0. Together, the model and data suggest that, at low contrasts across a wide spatiotemporal frequency range, monocular pathways are nearly linear in their contrast response (m close to 1), while a strongly accelerating nonlinearity (p=2, a 'soft threshold') occurs after binocular summation. [Supported by EPSRC project grant GR/S74515/01]

Perceiving edge blur: Gaussian-derivative filtering and a rectifying nonlinearity

We studied the visual mechanisms that encode edge blur in images. Our previous work suggested that the visual system spatially differentiates the luminance profile twice to create the `signature' of the edge, and then evaluates the spatial scale of this signature profile by applying Gaussian derivative templates of different sizes. The scale of the best-fitting template indicates the blur of the edge. In blur-matching experiments, a staircase procedure was used to adjust the blur of a comparison edge (40% contrast, 0.3 s duration) until it appeared to match the blur of test edges at different contrasts (5% - 40%) and blurs (6 - 32 min of arc). Results showed that lower-contrast edges looked progressively sharper. We also added a linear luminance gradient to blurred test edges. When the added gradient was of opposite polarity to the edge gradient, it made the edge look progressively sharper. Both effects can be explained quantitatively by the action of a half-wave rectifying nonlinearity that sits between the first and second (linear) differentiating stages. This rectifier was introduced to account for a range of other effects on perceived blur (Barbieri-Hesse and Georgeson, 2002 Perception 31 Supplement, 54), but it readily predicts the influence of the negative ramp. The effect of contrast arises because the rectifier has a threshold: it not only suppresses negative values but also small positive values. At low contrasts, more of the gradient profile falls below threshold and its effective spatial scale shrinks in size, leading to perceived sharpening.

Perceiving edge blur: linear filtering and a rectifying nonlinearity

We studied the visual mechanisms that encode edge blur in images. Our previous work suggested that the visual system spatially differentiates the luminance profile twice to create the 'signature' of the edge, and then evaluates the spatial scale of this signature profile by applying Gaussian derivative templates of different sizes. The scale of the best-fitting template indicates the blur of the edge. In blur-matching experiments, a staircase procedure was used to adjust the blur of a comparison edge (40% contrast, 0.3 s duration) until it appeared to match the blur of test edges at different contrasts (5% - 40%) and blurs (6 - 32 min of arc). Results showed that lower-contrast edges looked progressively sharper.We also added a linear luminance gradient to blurred test edges. When the added gradient was of opposite polarity to the edge gradient, it made the edge look progressively sharper. Both effects can be explained quantitatively by the action of a half-wave rectifying nonlinearity that sits between the first and second (linear) differentiating stages. This rectifier was introduced to account for a range of other effects on perceived blur (Barbieri-Hesse and Georgeson, 2002 Perception 31 Supplement, 54), but it readily predicts the influence of the negative ramp. The effect of contrast arises because the rectifier has a threshold: it not only suppresses negative values but also small positive values. At low contrasts, more of the gradient profile falls below threshold and its effective spatial scale shrinks in size, leading to perceived sharpening.

Seeing edge blur: receptive fields as multiscale neural templates

Edge blur is an important perceptual cue, but how does the visual system encode the degree of blur at edges? Blur could be measured by the width of the luminance gradient profile, peak ^ trough separation in the 2nd derivative profile, or the ratio of 1st-to-3rd derivative magnitudes. In template models, the system would store a set of templates of different sizes and find which one best fits the `signature' of the edge. The signature could be the luminance profile itself, or one of its spatial derivatives. I tested these possibilities in blur-matching experiments. In a 2AFC staircase procedure, observers adjusted the blur of Gaussian edges (30% contrast) to match the perceived blur of various non-Gaussian test edges. In experiment 1, test stimuli were mixtures of 2 Gaussian edges (eg 10 and 30 min of arc blur) at the same location, while in experiment 2, test stimuli were formed from a blurred edge sharpened to different extents by a compressive transformation. Predictions of the various models were tested against the blur-matching data, but only one model was strongly supported. This was the template model, in which the input signature is the 2nd derivative of the luminance profile, and the templates are applied to this signature at the zero-crossings. The templates are Gaussian derivative receptive fields that covary in width and length to form a self-similar set (ie same shape, different sizes). This naturally predicts that shorter edges should look sharper. As edge length gets shorter, responses of longer templates drop more than shorter ones, and so the response distribution shifts towards shorter (smaller) templates, signalling a sharper edge. The data confirmed this, including the scale-invariance implied by self-similarity, and a good fit was obtained from templates with a length-to-width ratio of about 1. The simultaneous analysis of edge blur and edge location may offer a new solution to the multiscale problem in edge detection.

Examination variability in short-wavelength automated perimetry

The study evaluated sources of within- and between-subject variability in standard white-on-white (W-W) perimetry and short-wavelength automated perimetry (SWAP). The Influence of staircase strategy on the fatigue effect in W-W perimetry was investigated for a 4 dB single step, single reversal strategy; a variable step size, single reversal dynamic strategy; and the standard 4-2 dB double reversal strategy. The fatigue effect increased as the duration of the examination Increased and was greatest in the second eye for all strategies. The fatigue effect was lowest for the 4dB strategy, which exhibited the shortest examination time and was greatest for the 4-2 dB strategy, which exhibited the longest examination time. Staircase efficiency was lowest for the 4 dB strategy and highest for the dynamic strategy which thus offers a reduced examination time and low inter-subject variability. The normal between-subject variability of SWAP was determined for the standard 4-2 dB double reversal strategy and the 3 dB single reversal FASTPAC strategy and compared to that of W-W perimetry, The decrease in sensitivity with Increase in age was greatest for SWAP. The between-subject variability of SWAP was greater than W-W perimetry. Correction for the Influence of ocular media absorption reduced the between-subject variability of SWAP, The FASTPAC strategy yielded the lowest between-subject variability In SWAP, but the greatest between-subject variability In WoW perimetry. The greater between-subject variability of SWAP has profound Implications for the delineation of visual field abnormality, The fatigue effect for the Full Threshold strategy in SWAP was evaluated with conventional opaque, and translucent occlusion of the fellow eye. SWAP exhibited a greater fatigue effect than W-W perimetry. Translucent occlusion reduced the between-subject variability of W-W perimetry but Increased the between-subject variability of SWAP. The elevation of sensitivity was greater with translucent occlusion which has implications for the statistical analysis of W-W perimetry and SWAP. The influence of age-related cataract extraction and IOL implantation upon the visual field derived by WoW perimetry and SWAP was determined. Cataract yielded a general reduction In sensitivity which was preferentially greater in SWAP, even after the correction of SWAP for the attenuation of the stimulus by the ocular media. There was no correlation between either backward or forward light scatter and the magnitude of the attenuation of W-W or SWAP sensitivity. The post-operative mean deviation in SWAP was positive and has ramifications for the statistical Interpretation of SWAP. Short-wavelength-sensitive pathway isolation was assessed as a function of stimulus eccentricity using the two-colour Increment threshold method. At least 15 dB of SWS pathway Isolation was achieved for 440 nm, 450 nm and 460 nm stimuli at a background luminance of 100 cdm-2, There was a slight decrease In SWS pathway Isolation for all stimulus wavelengths with increasing eccentricity which was not of clinical significance. Adopting a 450 nm stimulus may reduce between-subject variability In SWAP due to a reduction In ocular media absorption and macular pigment absorption.

Anatomical correlates of dynamic auditory processing:relationship to literacy during early adolescence

Adults show great variation in their auditory skills, such as being able to discriminate between foreign speech-sounds. Previous research has demonstrated that structural features of auditory cortex can predict auditory abilities; here we are interested in the maturation of 2-Hz frequency-modulation (FM) detection, a task thought to tap into mechanisms underlying language abilities. We hypothesized that an individual's FM threshold will correlate with gray-matter density in left Heschl's gyrus, and that this function-structure relationship will change through adolescence. To test this hypothesis, we collected anatomical magnetic resonance imaging data from participants who were tested and scanned at three time points: at 10, 11.5 and 13 years of age. Participants judged which of two tones contained FM; the modulation depth was adjusted using an adaptive staircase procedure and their threshold was calculated based on the geometric mean of the last eight reversals. Using voxel-based morphometry, we found that FM threshold was significantly correlated with gray-matter density in left Heschl's gyrus at the age of 10 years, but that this correlation weakened with age. While there were no differences between girls and boys at Times 1 and 2, at Time 3 there was a relationship between gray-matter density in left Heschl's gyrus in boys but not in girls. Taken together, our results confirm that the structure of the auditory cortex can predict temporal processing abilities, namely that gray-matter density in left Heschl's gyrus can predict 2-Hz FM detection threshold. This ability is dependent on the processing of sounds changing over time, a skill believed necessary for speech processing. We tested this assumption and found that FM threshold significantly correlated with spelling abilities at Time 1, but that this correlation was found only in boys. This correlation decreased at Time 2, and at Time 3 we found a significant correlation between reading and FM threshold, but again, only in boys. We examined the sex differences in both the imaging and behavioral data taking into account pubertal stages, and found that the correlation between FM threshold and spelling was strongest pre-pubertally, and the correlation between FM threshold and gray-matter density in left Heschl's gyrus was strongest mid-pubertally.

The roles of inducer size and distance in the Ebbinghaus illusion (Titchener circles)

Although the Ebbinghaus illusion is commonly used as an example of a simple size-contrast effect, previous studies have emphasised its complexity by identifying many factors that potentially influence the magnitude of the illusion. Here, in a series of three experiments, we attempt to simplify this complexity. In each trial, subjects saw a display comprising, on one side, a target stimulus surrounded by inducers and, on the other, an isolated probe stimulus. Their task was to indicate whether the probe appeared larger or smaller than the target. Probe size was adjusted with a one-up, one-down staircase procedure to find the point of subjective equality between probe and target. From these experiments, we argue that the apparent effects of inducer size are often confounded by the relative completeness of the inducing surround and that factors such as the similarity of the inducers and target are secondary. We suggest a simple model that can explain most of the data in terms of just two primary and independent factors: the relative size of the inducers and target, and the distance between the inducers and the target. The balance between these two factors determines whether the size of the target is underestimated or overestimated. © 2005 a Pion publication.

A comparison of fixed-step-size and Bayesian staircases for sensory threshold estimation

Fixed-step-size (FSS) and Bayesian staircases are widely used methods to estimate sensory thresholds in 2AFC tasks, although a direct comparison of both types of procedure under identical conditions has not previously been reported. A simulation study and an empirical test were conducted to compare the performance of optimized Bayesian staircases with that of four optimized variants of FSS staircase differing as to up-down rule. The ultimate goal was to determine whether FSS or Bayesian staircases are the best choice in experimental psychophysics. The comparison considered the properties of the estimates (i.e. bias and standard errors) in relation to their cost (i.e. the number of trials to completion). The simulation study showed that mean estimates of Bayesian and FSS staircases are dependable when sufficient trials are given and that, in both cases, the standard deviation (SD) of the estimates decreases with number of trials, although the SD of Bayesian estimates is always lower than that of FSS estimates (and thus, Bayesian staircases are more efficient). The empirical test did not support these conclusions, as (1) neither procedure rendered estimates converging on some value, (2) standard deviations did not follow the expected pattern of decrease with number of trials, and (3) both procedures appeared to be equally efficient. Potential factors explaining the discrepancies between simulation and empirical results are commented upon and, all things considered, a sensible recommendation is for psychophysicists to run no fewer than 18 and no more than 30 reversals of an FSS staircase implementing the 1-up/3-down rule.

Transmission electron tomography: quality assessment and enhancement for three-dimensional imaging of nanostructures

Nanotechnology has revolutionised humanity's capability in building microscopic systems by manipulating materials on a molecular and atomic scale. Nan-osystems are becoming increasingly smaller and more complex from the chemical perspective which increases the demand for microscopic characterisation techniques. Among others, transmission electron microscopy (TEM) is an indispensable tool that is increasingly used to study the structures of nanosystems down to the molecular and atomic scale. However, despite the effectivity of this tool, it can only provide 2-dimensional projection (shadow) images of the 3D structure, leaving the 3-dimensional information hidden which can lead to incomplete or erroneous characterization. One very promising inspection method is Electron Tomography (ET), which is rapidly becoming an important tool to explore the 3D nano-world. ET provides (sub-)nanometer resolution in all three dimensions of the sample under investigation. However, the fidelity of the ET tomogram that is achieved by current ET reconstruction procedures remains a major challenge. This thesis addresses the assessment and advancement of electron tomographic methods to enable high-fidelity three-dimensional investigations. A quality assessment investigation was conducted to provide a quality quantitative analysis of the main established ET reconstruction algorithms and to study the influence of the experimental conditions on the quality of the reconstructed ET tomogram. Regular shaped nanoparticles were used as a ground-truth for this study. It is concluded that the fidelity of the post-reconstruction quantitative analysis and segmentation is limited, mainly by the fidelity of the reconstructed ET tomogram. This motivates the development of an improved tomographic reconstruction process. In this thesis, a novel ET method was proposed, named dictionary learning electron tomography (DLET). DLET is based on the recent mathematical theorem of compressed sensing (CS) which employs the sparsity of ET tomograms to enable accurate reconstruction from undersampled (S)TEM tilt series. DLET learns the sparsifying transform (dictionary) in an adaptive way and reconstructs the tomogram simultaneously from highly undersampled tilt series. In this method, the sparsity is applied on overlapping image patches favouring local structures. Furthermore, the dictionary is adapted to the specific tomogram instance, thereby favouring better sparsity and consequently higher quality reconstructions. The reconstruction algorithm is based on an alternating procedure that learns the sparsifying dictionary and employs it to remove artifacts and noise in one step, and then restores the tomogram data in the other step. Simulation and real ET experiments of several morphologies are performed with a variety of setups. Reconstruction results validate its efficiency in both noiseless and noisy cases and show that it yields an improved reconstruction quality with fast convergence. The proposed method enables the recovery of high-fidelity information without the need to worry about what sparsifying transform to select or whether the images used strictly follow the pre-conditions of a certain transform (e.g. strictly piecewise constant for Total Variation minimisation). This can also avoid artifacts that can be introduced by specific sparsifying transforms (e.g. the staircase artifacts the may result when using Total Variation minimisation). Moreover, this thesis shows how reliable elementally sensitive tomography using EELS is possible with the aid of both appropriate use of Dual electron energy loss spectroscopy (DualEELS) and the DLET compressed sensing algorithm to make the best use of the limited data volume and signal to noise inherent in core-loss electron energy loss spectroscopy (EELS) from nanoparticles of an industrially important material. Taken together, the results presented in this thesis demonstrates how high-fidelity ET reconstructions can be achieved using a compressed sensing approach.

As Escadarias de Terraços do Ródão à Chamusca (Baixo Tejo) - Caracterização e Interpretação de Dados Sedimentares, Tectónicos, Climáticos e do Paleolítico

As unidades estratigráficas que resultaram da evolução do rio Tejo em Portugal, aqui analisadas em pormenor entre Vila Velha de Ródão e Chamusca, possuem distintas características sedimentares e indústrias líticas: uma unidade culminante do enchimento sedimentar (o ancestral Tejo, antes do início da etapa de incisão fluvial) - SLD13 (+142 a 262 m acima do leito actual; com provável idade 3,6 a 1,8 Ma), sem indústrias identificadas; terraço T1 (+76 a 180 m; ca. 1000? a 900 ka), sem indústrias; terraço T2 (+57 a 150 m; idade estimada em ca. 600 ka), sem indústrias; terraço T3 (+36 a 113 m; ca. 460 a 360? ka), sem indústrias; terraço T4 (+26 a 55 m; ca. 335 a 155 ka), Paleolítico Inferior (Acheulense) em níveis da base e intermédios mas Paleolítico Médio inicial em níveis do topo; terraço T5 (+5 a 34 m; 135 a 73 ka), Paleolítico Médio (com talhe Mustierense, Levallois); terraço T6 (+3 a 14 m; 62 a 32 ka), Paleolítico Médio final (Mustierense final); Areias da Carregueira (areias eólicas) e coluviões (+3 a ca. 100 m; 32 a 12 ka), Paleolítico Superior a Epipaleolítico; enchimento da planície aluvial (+0 a 8 m; ca. 12 ka a actual), Mesolítico e indústrias mais recentes. As diferenças na elevação (a.r.b.) das escadarias de terraços resultam de soerguimento diferencial, devido a falhas ativas. Numa dada escadaria datada, a projeção da elevação da superfície de cada terraço (a.r.b.) versus a sua idade permitiu estimar a idade do topo do terraço T2 (ca. 600 ka) e a provável idade do início da etapa de incisão (ca. 1,8 Ma). Obteve-se a duração da fase de agradação dos terraços baixos e médios: T6 – 30 ka; T5 – 62 ka; T4 – ca. 180 ka; T3 – ca. 100? ka. Conclui-se que durante o Plistocénico médio e final, as fases de incisão e alargamento do vale foram curtas (ca. 11-25 ka) e ocorreram durante períodos de nível do mar muito baixo, alternando com mais longas fases de inundação e agradação do vale durante níveis do mar mais altos. Estas oscilações eustáticas de causa climática estão sobrepostas a um contexto de soerguimento de longo termo, controlando o desenvolvimento das escadarias. Calculou-se que para os últimos ca. 155 ka as taxas de incisão de curto-termo apresentam valores (0,09 a 0,41 m/ka), aproximadamente, duplos dos calculados para o intervalo ca. 155 a 900 ka (0,04 a 0,28 m/ka). Este aumento na taxa de incisão deve estar relacionado com um aumento na taxa de soerguimento por intensificação da compressão devido à convergência entre as placas Africana e Eurasiática. Abstract: The terrace staircases of the Lower Tagus River (Ródão to Chamusca) – characterization and interpretation of the sedimentary, tectonic, climatic and Palaeolithic data The stratigraphic units that record the evolution of the Tagus River in Portugal (study area between Vila Velha de Ródão and Chamusca villages) have different sedimentary characteristics and lithic industries: a culminant sedimentary unit (the ancestral Tagus, before the drainage network entrenchment) – SLD13 (+142 to 262 m above river bed – a.r.b.; with probable age 3.6 to 1.8 Ma), without artefacts; T1 terrace (+76 to 180 m; ca. 1000? to 900 ka), without artefacts; T2 terrace (+57 to 150 m; top deposits with a probable age ca. 600 ka), without artefacts; T3 terrace (+36 to 113 m; ca. 460 to 360? ka), without artefacts; T4 terrace (+26 to 55 m; ca. 335 a 155 ka), Lower Paleolithic (Acheulian) at basal and middle levels but early Middle Paleolithic at top levels; T5 terrace (+5 to 34 m; 135 to 73 ka), Middle Paleolithic (Mousterian; Levallois technique); T6 terrace (+3 to 14 m; 62 to 32 ka), late Middle Paleolithic (late Mousterian); Carregueira Sands (aeolian sands) and colluvium (+3 a ca. 100 m; 32 to 12 ka), Upper Paleolithic to Epipaleolithic; alluvial plain (+0 to 8 m; ca. 12 ka to present), Mesolithic and more recent industries. The differences in elevation (a.r.b.) of the several terrace staircases results from differential uplift due to active faults. The age interval for each aggradation phase of T3 to T6 terraces was obtained: T3 – ca. 100? ka; T4 – ca. 180 ka; T5 – 62 ka; T6 – 30 ka. The intervals of river down-cutting and widening of the valley floor were short (ca. 11-25 ka) and coincided with periods of very low sea-level. The plotting of the elevation (a.r.b.) versus the age of each terrace surface allows to estimate the age of the T2 terrace (ca. 600 ka) and the probable age of the beginning of the incision stage (ca. 1.8 Ma). So, the high amplitude sea-level changes that characterized the Middle and Late Pleistocene strongly determined the episodic down-cutting phases of the river during the low stands sea levels that alternated with the flooding and aggradation phases of the incised valley during highstand sea levels. These climate related eustatic oscillations are superimposed onto a long term uplift pattern, controlling the river terrace staircase development. During the last ca. 155 ka, the short-term incision rates (0.09 a 0.41 m/ka) were twice the values determined for the interval 155 to 900 ka (0.04 to 0.28 m/ka). This increase in incision rate should be related with an increase in uplift rate resulting from an intensification of compression due to the convergence between African - Eurasian plates.