Miracle-dz/UniFAR-FTUs huggingface dataset:
Palaeomagnetism of neoproterozoic formations in the volta basin

The Volta basin lies on the southern part of the West African craton, more precisely on the Leo (or Man) craton. The Dahomeyides chain is thrust onto its eastern fringe. The Volta basin is filled with Neoproterozoic to Cambro- Ordovician sediments. From bottom to top they are: the Boumbouaka Supergroup made of sandstone, micro-conglomerates, siltstones, shales and limestone lenses; the Pendjari or Oti Supergroup composed of a triad made of a diamictite, a cap carbonate and a silexitic complex that passes upwards to siltstones and shales; the Tamale Supergroup representing the molasse of the Dahomeyides chain. The three supergroups were sampled for palaeomagnetic study. The magnetic mineralogical study shows magnetite and hematite as carriers of magnetization. Mean palaeomagnetic directions are calculated on the high temperature components and yield a mean palaeopole, Plon=349.3°, Plat=44.1°, dp=26.6°, dm=33.7°, for formations with ages between 993±62 Ma and 660±9 Ma and a mean palaeopole, Plon=119.5°, Plat=71.2°, dp=19.8°, dm=38.1°, for sites dated between 635 Ma and 600 Ma which are, respectively, the ages of the marinoan glaciations in Volta basin and the Pan-African deformation, responsible of the Dahomeyides chain. The palaeolatitudes of the older formations about 44.9° S and that of the younger sites about 9.1° S show a migration of the West African craton from medium to low latitude during the Neoproterozoic, in conformity with the Snowball Earth hypothesis. KEYWORDS: West African craton, Volta basin, Virtual Geomagnetic Pole, Palaeolatitude, Snowball Earth
Interpretation of Forest Harvest Conditions in New Brunswick Using Landsat TM Enhanced Wetness Difference Imagery (EWDI)

RÉSUMÉ On décrit des zones de coupes à blanc et de coupes partielles ainsi que les conditions sylvicoles des peuplements forestiers au Nouveau-Brunswick au cours d'une période d'un an (1997–1998) au moyen de l'interprétation visuelle des différences observées suite à l'application de la transformation «Tasseled Cap» sur deux images Landsat Thematic Mapper. Une image rehaussée des différences d'humidité (EWDI) a été utilisée pour créer des exemples de changements reliés à des conditions de changements connues au sol; nous avons interprété des patrons distinctifs dans les compositions colorées normales et l'image EWDI associés avec les coupes à blanc, les coupes progressives et les coupes d'ensemencement, les coupes par bandes et les coupes associées au jardinage par groupe, et les éclaircies précommerciales et commerciales. Notre interprétation suggère que ces traitements au niveau des peuplements forestiers et les patrons spectraux qu'ils entraînent pourraient servir de base pour le développement d'une méthode de classification ou potentiellement d'un système automatisé de détection et de suivi.
Modeling air movement and bubble trapping in firn

A finite difference model for gas diffusion and bubble trapping in firn is described. The model uses prescribed profiles of density, open and closed porosity, and diffusivity to determine the diffusion and trapping processes. The model is calibrated and tested by using measured air composition in the firn at the DE08-2 site on Law Dome, Antarctica. In particular, we focus on carbon dioxide (CO2), methane (CH4), and sulfur hexafluoride (SF6), which have well-determined atmospheric records (CO2 since 1958, CH4 since 1983, and SF6 since 1978). These trace gases are used to tune the diffusivity-porosity relationship, which is the most uncertain of the model inputs. Modeled trace gas profiles in the DE08-2 firn are improved if allowance is made for reduced diffusion through the most prominent DE08-2 melt layer from the summer of 1989/1990. The relatively rapid growth rate of SF6 in the atmosphere permits good definition of the diffusion reduction due to the melt layer (about 80%). The model quantifies the smoothing effect of the firn diffusion and bubble trapping on atmospheric signals. Gravitational separation in the firn is investigated by comparison of modeled δ15N2 with observations. The model is used to calculate the isotopic diffusion correction for δ13C02 and δ13CH4. This corrects for the fractionating effects of the firn diffusion process on the different isotopes. The diffusion and gravitational corrections are critical at the measurement precision currently being obtained; for δ13CO2 the diffusion correction is up to about 10 times the current measurement precision. The diffusion correction is even more significant for δ13CH4; at over 1‰ at the bottom of the firn it is more than double the change over the last decade. The fully corrected δ13C02 record from the DE08-2 firn is compared with the history of Cape Grim direct atmospheric measurements with excellent agreement.
Kurilite – Ag8Te3Se – a new mineral from the Prasolovskoe deposit, Kuril islands, Russian Federation

Abstract Kurilite, with the simplified formula, Ag8Te3Se, is a new mineral from the Prasolovskoe epithermal Au-Ag deposit, Kunashir Island, Kuril arc, Russian Federation. It occurs as aggregates up to 2 mm in size, composed of brittle xenomorphic grains, up to several μm in size, in quartz, associated with tetrahedrite, hessite, sylvanite and petzite. Kurilite is opaque, grey, with a metallic lustre and a black streak. Under plane-polarized light, kurilite is white with no observed bireflectance, cleavage, or parting observed. Under crossed polars it appears isotropic without internal reflections. Reflectance values in air and in oil, are tabulated. It has a mean VHN (25 g load) of 99.9 kg/mm2 which equates roughly to a Mohs hardness of 3. Electron microprobe analyses yield a mean composition of Ag 63.71, Au 0.29, Te 29.48, Se 5.04, S 0.07, total 98.71 wt. %. The empirical formula (based on 12 atoms) is (Ag7.97Au0.02)∑7.99Te3. 00(Se0.86Te0.12S0.03)∑1.01. The calculated density is 7.799 g/cm3 (based on the empirical formula and unit-cell parameters refined from single-crystal data). Kurilite is rhombohedral, R3 or R3̄, a 15.80(1), c 19.57(6) Å, V 4231(12)Å3, c:a 1.2386, Z = 15. Its crystal structure remains unsolved. The seven strongest lines of the X-ray powder-diffraction pattern [d in Å (I)(hkl)] are: 3.727(20)(131), 2.996(50)(232), 2.510(30)(226,422), 2.201(100)(128,416,342), 2.152(20)(603), 2.079(30)(253), 2.046(20)(336,434). The mineral is named after the locality.
Geomorphology and structural segmentation of the crest of the southern (Pacific‐Antarctic) East Pacific Rise

Geomorphology of the boundary between Pacific and Antarctic plates was mapped with a Sea Beam multibeam echosounder and a SeaMARC II bathymetric side scan sonar, from the southern end of Juan Fernandez microplate at 35°S to Heezen transform at 56°S. There are six spreading center systems separated by two large, left-stepping nontransform offsets (at 36.5°S and 41.5°S), two right-stepping transform-fault systems, and a left-stepping hybrid structure with equally long strike-slip and nontransform offsets. Axial rift zones (spreading axes) are generally within 1° of normal to the relative motion predicted by current plate rotation models. Most axial rift zones crop out along the crests of typical East Pacific Rise (EPR) axial ridges which commonly have flat rather than humped long profiles. About 2% of this fast-spreading (84–100 mm/yr) rise crest has an axial rift valley instead of an axial ridge. The longest rift-valley segment is midway between Menard and Vacquier transforms near 51°S, where an anomalously deep rise crest may mark a zone of below-average mantle upwelling. Nontransform offsets structurally similar to those on the tropical EPR, but mostly formed by differential asymmetric spreading, subdivide the four longest spreading center systems. On the northern, transform-free two thirds of the rise, net rift propagation at migrating offsets has been into the faster Pacific plate. This causes right steps to migrate north, left steps to migrate south, and crust to be transferred to the east flank. This pattern has prevailed for several million years, judging from the oblique fracture zones (pseudofaults) mapped on the rise flanks with older marine data and Geosat altimetry. On this rise crest, the difference in stress on two plates with very different velocities may control the direction of offset migration.
Study of parallel numerical methods for semiconductor device simulation

Simulators of semiconductor devices have to solve systems of equations generated by the discretization of partial differential equations, which are the most time‐consuming part of the simulation process. Therefore, the use of an effective method to solve these linear systems is essential. In this work we have evaluated the efficiency of different parallel direct and iterative solvers used for the solution of the drift–diffusion equations in semiconductor device simulation. Several preconditioning techniques have been applied in order to minimize the execution times. We have found that FGMRES and BCGSTAB solvers preconditioned with Additive Schwarz are the most suitable for these types of problems. The results were obtained in an HP Superdome cluster with 128 Itanium2 1.5 GHz. Copyright © 2005 John Wiley & Sons, Ltd.
Evidence of dynamic scaling in space‐time rainfall

As in any evolving process, including rainfall, variability in space and time are not independent of each other but depend in a way particular to the process at hand. Understanding and quantifying the space-time dependences in a process over a range of scales is not always easy because these dependences may be hidden under complex patterns with pronounced statistical variability at all scales. In this paper, we report our efforts to understand the spatiotemporal organization of rainfall at a range of scaies (2 km to 20 km in space and 10 min to several hours in time) and explore the existence of simple relationships which might connect the rate of rainfall pattern evolution at small space and time scales to that at larger scales. Specifically, we seek to understand whether there exist space-time transformations under which these relationships can be parameterized in a simple scale-invariant framework. On the basis of analysis of several tropical convective storms in Darwin, Australia, we found that the rate of evolution of rainfall remains invariant under space-time transformations of the form t ∼ L z (dynamic scaling). In other words, the dependence of the statistical structure of rainfall on space (L) and time (t) can be reduced to a single parameter t/L z , where z is called the dynamic scaling exponent. The space-time organization in rainfall, apart from being interesting in its own right, permits the development of simple rainfall downscaling schemes which incorporate both spatial and temporal persistence.
Methane emissions from rice fields: Effect of soil properties

Flooded rice fields emit methane and are important contributors to the increasing atmospheric methane concentration. Various estimates of global release rates of methane from rice paddies range from a low of 20 Tg per year to a high of 200 Tg per year. Global estimates of methane emissions from rice fields depend upon obtaining reliable data from a variety of soil types. We have compared a variety of methane emission data sets obtained over a four-year period from three different soil types found at the Texas Agricultural Experiment Station near Beaumont, Texas, with several physical and chemical properties of the soils. We find that seasonal methane emissions directly correlate with the percent sand in the soils. Along a transect with soil sand content ranging from 18.8% to 32.5%, seasonal methane emissions ranged from 15.1 g m −2 to 36.3 g m−2.
Structural frame work of the fore-arc basin, NW Sumatra

The fore-arc basin of the Sunda Arc off Sumatra is a strongly subsiding trough contained between the rising subduction complex and the elevated continental core. Up to 4 km of Miocene–Recent strata on the eastern flank of the basin have transgressed over an unconformity cut across a Palaeogene continental margin that was uplifted and structurally disrupted during the late Oligocene. The large step-like offsets of the palaeo-shelf edge, and probably some of the structural disruption, can be attributed to right-lateral strike-slip faults that splay across the fore-arc basin from the Sumatra Fault Zone. Offsets range up to 100 km+, producing marginal re-entrants that became sites of turbidite-filled basins trapped behind the growing Neogene accretionary prism. The larger re-entrants may be floored with oceanic crust, but the proximity of exposed subduction complex to the palaeo-margin precludes the existence of a continuous band of oceanic crust beneath the fore-arc basin. The seaward flank of the fore-arc basin has migrated westwards during Neogene subduction, but not so much as the trench, and in a much more complicated fashion. During the early Miocene, the inner trench slope had a juvenile terrace-like morphology. By late mid-Miocene time, the trench slope break was near sea level and formed a shelf edge high. Thrusting and folding related to subduction probably decreased gradually upslope until late-Pliocene, when large flexures and E-directed reverse faults developed, marking an arcward shift in the rear or eastern boundary of the deformation associated with subduction. The episodic development of arcward-directed structures, involving previously stabilized fore-arc basin strata, suggests periods of increased stress levels along the base of the accretionary prism.
Modelling of water flow through typical Bavarian soils: 1. Estimation of hydraulic characteristics of the unsaturated zone

Abstract Over an eight-year period (1984–1991), seven experimental lysimeters filled with different soil materials from the State of Bavaria (quartz and tertiary sands, quartz and fluvioglacial gravels) were used to study water flow and tracer transport through the unsaturated zone under natural atmospheric conditions. The experiments were performed in the input—output mode using weekly water flow and tracer contents (environmental deuterium) in the precipitation and in the outflow in order to estimate the unsaturated hydraulic and transport parameters of the soils with limited measured data. This paper (Part 1) presents the evaluation of soil hydraulic parameters for tested soils, while the second paper (Part 2) is concerned with the estimation of transport parameters (dispersion, water content and possible zones with stagnant water). The estimation of the soil physical characteristics, i.e. the relationship between water pressure head and water content, performed by applying the van Genuchten model, showed a satisfactory accuracy against the measured data. Determination of the hydraulic conductivity as a function of water content using the van Genuchten-Mualem conductivity model did not yield good results, due to the fact that the theoretical water flow model based on such soil parameters was not able to fit the measured values of water content at the upper 20 cm and the cumulative water outflow simultaneously. To estimate the conductivity—water content characteristics, the inverse modelling technique was used for each lysimeter. The cumulative outflow curves were fitted to the observed outflow data by a trial-and-error procedure using the conductivity—water content relationship as the fitting function. It was shown that this method of estimating the soil characteristics yields parameters which are closer to the true values compared to those found in small-scale column experiments. The soil characteristics obtained in this part of the study were further used for modelling environmental deuterium transport through the soils (Part 2).
High-Resolution Satellite Measurements of the Atmospheric Boundary Layer Response to SST Variations along the Agulhas Return Current

Abstract The marine atmospheric boundary layer (MABL) response to sea surface temperature (SST) perturbations with wavelengths shorter than 30° longitude by 10° latitude along the Agulhas Return Current (ARC) is described from the first year of SST and cloud liquid water (CLW) measurements from the Advanced Microwave Scanning Radiometer (AMSR) on the Earth Observing System (EOS) Aqua satellite and surface wind stress measurements from the QuikSCAT scatterometer. AMSR measurements of SST at a resolution of 58 km considerably improves upon a previous analysis that used the Reynolds SST analyses, which underestimate the short-scale SST gradient magnitude over the ARC region by more than a factor of 5. The AMSR SST data thus provide the first quantitatively accurate depiction of the SST-induced MABL response along the ARC. Warm (cold) SST perturbations produce positive (negative) wind stress magnitude perturbations, leading to short-scale perturbations in the wind stress curl and divergence fields that are li.
Does the Sverdrup critical depth model explain bloom dynamics in estuaries

In this paper we use numerical models of coupled biological-hydrodynamic processes to search for general principles of bloom regulation in estuarine waters. We address three questions: What are the dynamics of stratie cation in coastal systems as ine uenced by variable freshwater input and tidal stirring? How does phytoplankton growth respond to these dynamics? Can the classical Sverdrup Critical Depth Model (SCDM) be used to predict the timing of bloom events in shallow coastal domains such as estuaries? We present results of simulation experiments which assume that vertical transport and net phytoplankton growth rates are horizontally homogeneous. In the present approach the temporally and spatially varying turbulent diffusivities for various stratie cation scenarios are calculated using a hydrodynamic code that includes the Mellor-Yamada 2.5 turbulence closure model. These diffusivities are then used in a time- and depth-dependent advection-diffusion equation, incorporating sources and sinks, for the phytoplankton biomass. Our modeling results show that, whereas persistent stratie cation greatly increases the probability of a bloom, semidiurnal periodic stratie cation does not increase the likelihood of a phytoplankton bloom over that of a constantly unstratie ed water column. Thus, for phytoplankton blooms, the physical regime of periodic stratie cation is closer to complete mixing than to persistent stratie cation. Furthermore, the details of persistent stratie cation are important: surface layer depth, thickness of the pycnocline, vertical density difference, and tidal current speed all weigh heavily in producing conditions which promote the onset of phytoplankton blooms. Our model results for shallow tidal systems do not conform to the classical concepts of stratie cation and blooms in deep pelagic systems. First, earlier studies (Riley, 1942, for example) suggest a monotonic increase in surface layer production as the surface layer shallows. Our model results suggest, however, a nonmonotonic relationship between phytoplankton population growth and surface layer depth, which results from a balance between several ‘ ‘ competing’ ’ processes, including the interaction of sinking with turbulent mixing and average net growth occurring within the surface layer. Second, we show that the traditional SCDM must be ree ned for application to energetic shallow systems or for systems in which surface layer mixing is not strong enough to counteract the sinking loss of phytoplankton. This need for ree nement arises because of the leakage of phytoplankton from the surface layer by turbulent diffusion and sinking, processes not considered in the classical SCDM. Our model shows that, even for low sinking rates and small turbulent
Comprehensive comparative assessment of the Arabidopsis thaliana MLO2–CALMODULIN2 interaction by various in vitro and in vivo protein–protein interaction assays

Mildew resistance locus o (MLO) proteins are heptahelical integral membrane proteins of which some isoforms act as susceptibility factors for the powdery mildew pathogen. In many angiosperm plant species, loss-of-function mlo mutants confer durable broad-spectrum resistance against the fungal disease. Barley Mlo is known to interact via a cytosolic carboxyl-terminal domain with the intracellular calcium sensor calmodulin (CAM) in a calcium-dependent manner. Site-directed mutagenesis has revealed key amino acid residues in the barley Mlo calmodulin-binding domain (CAMBD) that, when mutated, affect the MLO–CAM association. We here tested the respective interaction between Arabidopsis thaliana MLO2 and CAM2 using seven different types of in vitro and in vivo protein–protein interaction assays. In each assay, we deployed a wild-type version of either the MLO2 carboxyl terminus (MLO2CT), harboring the CAMBD, or the MLO2 full-length protein and corresponding mutant variants in which two key residues within the CAMBD were substituted by non-functional amino acids. We focused in particular on the substitution of two hydrophobic amino acids (LW/RR mutant) and found in most protein–protein interaction experiments reduced binding of CAM2 to the corresponding MLO2/MLO2CT-LW/RR mutant variants in comparison with the respective wild-type versions. However, the Ura3-based yeast split-ubiquitin system and in planta bimolecular fluorescence complementation (BiFC) assays failed to indicate reduced CAM2 binding to the mutated CAMBD. Our data shed further light on the interaction of MLO and CAM proteins and provide a comprehensive comparative assessment of different types of protein–protein interaction assays with wild-type and mutant versions of an integral membrane protein.
Tonga Ridge and Lau Basin crustal structure from seismic refraction data

[1] The crustal structure across the Tonga-Lau arc-back arc system from the Lau Ridge to the Pacific Plate (178°–170°W, 18°19°S) is modeled, using data from an 840-km-long air gun refraction line over 19 ocean bottom seismometers and one land station. The data reveal that the Pacific Plate crust is 5.5 km thick, with a velocity structure similar to that found at the present-day East Pacific Rise (EPR). Beneath Tonga Ridge, an intermediate velocity layer (6–7 km/s) is up to 7.5 km thick and has a velocity-depth distribution similar to andesitic rocks found in continental crust. The crust is abnormally thin (4 km) at the boundary between the Tonga Ridge and the Lau Basin. At the east end of Lau Basin, the crust is 5.5–6.5 km thick and resembles crust formed at the EPR except for a thicker sheeted-dike section (2–3 km) and thinner lower crust (2 km). The Lau Basin crust thickens to 7–8 km near the Central Lau Spreading Center (CLSC), mostly through thickening of the lower crust. The crust thickens again to 8.5–9.5 km at 50 km west of the CLSC, mostly through thickening of the midcrust. In the thick westernmost section, the crustal structure is uniform even though one part of this section formed through extension of arc-type crust while the rest was created at an oceanic spreading center. The relative homogeneity of these rocks suggests that their petrology may be dominated by postemplacement magmatic infilling from a mantle source west of the spreading center.
Language-Based Access to Gestural Components of Conceptual Knowledge

We report two experiments in which production of articulated hand gestures was used to reveal the nature of gestural knowledge evoked by sentences referring to manipulable objects. Two gesture types were examined: functional gestures (executed when using an object for its intended purpose) and volumetric gestures (used when picking up an object simply to move it). Participants read aloud a sentence that referred to an object but did not mention any form of manual interaction (e.g., Jane forgot the calculator) and were cued after a delay of 300 or 750 ms to produce the functional or volumetric gesture associated with the object, or a gesture that was unrelated to the object. At both cue delays, functional gestures were primed relative to unrelated gestures, but no significant priming was found for volumetric gestures. Our findings elucidate the types of motor representations that are directly linked to the meaning of words referring to manipulable objects in sentences.