Miracle-dz/UniFAR-FTUs huggingface dataset:
Technologies de l'information et de la communication et indigènes numériques : quelle situation ?

Les jeunes utilisent beaucoup les technologies de l’information ; et de la communication dans leur vie quotidienne. Mais dans quelle mesure et comment acquierent-ils les competences techniques et les savoirs generaux necessaires a un usage raisonne de celles-ci ? Cet article, qui reprend des elements d’un rapport effectue pour le CERI-OCDE en 2008 sur les apprenants du nouveau millenaire (new millenium learners), presente un etat de la question et discute certaines des consequences pour les EIAH. Ses principales conclusions sont que si les equipements sont maintenant devenus banals, on attribue aux enfants et aux adolescents, cibles privilegiees pour le marketing, beaucoup plus de competences que la majorite d’entre eux n’en possede. Par ailleurs, il est bien atteste par les etudes menees a ce jour que les usages de ces technologies en classe et plus largement en formation, malgre une infrastructure bien developpee, restent faibles et qu’il existe un hiatus important entre les pratiques scolaires et celles qui se developpement dans la sphere privee. Cet etat de fait invite a une reflexion nouvelle sur le developpement d’environnements et de ressources a usage educatif.
Potential for Intrinsic Bioremediation of a DNT‐Contaminated Aquifer

Microorganisms indigenous to a shallow aquifer, which underlies an explosives‐contaminated site, mineralized 28% of [U‐ring‐14C] 2,4–dinitrotoluene to 14CO2 within 28 days under aerobic conditions. Approximately 20% of added 2,4–dinitrotoluene remained undegraded at the end of the incubation while approximately 22% and 6% were transformed to 4–amino‐2–nitrotoluene and 2–amino‐4–nitrotoluene, respectively. In aquifer microcosms containing 2,6–dinitrotoluene, approximately 67% of the substrate remained undegraded and approximately 14% was transformed to 2–amino‐6–nitrotoluene. The radiolabeled study indicated that about 8% of the 2,6–dinotrotoluene was mineralized to CO2. The demonstrated degradation and subsequent mineralization of dinitrotoluene compounds by aquifer microorganisms are consistent with the decline in dissolved dinitrotoluene concentrations observed along the general ground‐water flowpath at the site. The results indicate that intrinsic bioremediation may be a viable alternative for remediating contaminated ground water at this site.
On the influence of DSOW in a numerical model of the North Atlantic general circulation

Abstract Two numerical experiments regarding the North Atlantic circulation are compared. The two experiments are initialized with climatological temperatures and salinities and are integrated for ten years with different surface boundary conditions in the lceland Sea. One case climatological wind stress, SST, and surface salinity to force the model. It reproduces the Atlantic circulation found in similar studies. A change in surface boundary values In the Iceland Sea in order to improve the Denmark Strait Overflow water properties in the second case results in major changes in circulation and hydrography. The meridional overturning more than doubles and horizontal gyres are intensified. Recirculation cells occur north and south of the Gulf Stream. The Gulf Stream separates from the North American coast in a more realistic manner, and its further course is in better agreement with observations than in the reference run. The subsurface temperature distribution differs by several kelvin in the subpolar and .
Optical properties of the Indo-Asian haze layer over the tropical Indian Ocean

[1] Multiwavelength backscatter and extinction profiling was performed with a unique aerosol Raman lidar at Hulhule (4� N, 73� E), Maldives, as part of the Indian Ocean Experiment (INDOEX) between February 1999 and March 2000. The Raman lidar allowed a direct determination of the volume extinction coefficient of the particles at 355 and 532 nm at ambient conditions. Heavily polluted air masses from the Asian continent passed over the Maldives during the northeast monsoon seasons. The mean 532-nm particle optical depth was about 0.3; maximum values of 0.7 were measured. Above the polluted marine boundary layer, lofted plumes were found up to 4000-m height. On average, the freetropospheric aerosol layers contributed 30–60% to the particle optical depth. The volume extinction coefficient at 532 nm typically ranged from 25 to 175 Mm � 1 in the elevated layers. The pollution plumes are characterized separately for the air masses from Southeast Asia, North India, and South India. The analysis includes backward trajectories and emission inventory data for India. The extinction-to-backscatter ratio (lidar ratio) at 532 nm was mostly between 30 and 100 sr, and accumulated at 50–80 sr for highly absorbing particles from northern India. The shift of the lidar-ratio distribution for northern Indian aerosols by about 20 sr toward larger values compared to European values is consistent
Single sensor-based 3D feature point location for a small flying robot application using one camera

Finding the location of feature points in 3D space from 2D vision data in structured environments has been done successfully for years and has been applied effectively on industrial robots. Miniature flying robots flying in unknown environments have stringent weight, space, and security constraints. For such vehicles, it has been attempted here to reduce the number of vision sensors to a single camera. At first, feature points are detected in the image using Harris corner detector, the measurements of which are then statistically corresponded across various images, using knowledge of vehicle’s pose from onboard inertial measurement unit. First approach attempted is that of ego-motion perpendicular to camera axis and acceptable results for 3D feature point locations have been achieved. Next, except for a small region around the focus of expansion, forward translations along the camera axis have also been attempted with acceptable results, which is an improvement to the previous relevant work. The 3D location map of feature points thus obtained is utilizable for trajectory planning while ensuring collision avoidance through 3D space. Reduction of vision sensors to a single camera while utilizing minimum ego-motion space for 3D feature point location is a significant contribution of this work.
Assessment of different models for bathymetry calculation using SPOT multispectral images in a high-turbidity area: the mouth of the Guadiana Estuary

Periodic calculation of coastal bathymetries can show the evolution of geomorphological features in active areas such as mesotidal estuary mouths. Bathymetries in shallow coastal areas have been addressed mainly by two technologies, lidar and optical remote sensing. Lidar provides good accuracy, but is an expensive technique, requiring planned flights for each region and dates of interest. Optical remote sensing acquires images periodically but its results are limited by water turbidity. Here we use a lidar bathymetry to compare different bathymetry computation methods using a SPOT optical image from a nearby date. Three statistical models (green-band, PCA correlations, and GLM) were applied to obtain mathematical expressions to estimate bathymetry from that image: all gave errors lower than 1 m in an area with depths ranging from 0 to 6 m. These algorithms were then applied to images from three different dates, correcting the effects caused by different tidal and atmospheric conditions. We show how this allows the study of morphological changes. We discuss the accuracy obtained with respect to the reference bathymetry (0.9 m on average, but less than 0.5 m in low-turbidity areas), the effects of the turbidity on our estimations, and compare both with previously published results. The results show that this approach is effective and allows identification of known features of coastal dynamics, and thus it would be an important step towards short-term bathymetry monitoring based on optical satellite remote sensing.
Variations in axial morphology along the Galápagos spreading center and the influence of the Galápagos hotspot

The Galapagos Spreading Center (GSC) is marked by systematic changes in axial morphology between the Inca Fracture Zone (FZ) at 85.5°W and the 95.5°W propagator. We analyze these changes using new swath bathymetry and magnetic data acquired aboard the B/O Hesperides during the Galapagos'96 experiment. Within ∼350 km of the Galapagos hotspot the ridge axis is associated with an East Pacific Rise (EPR)-like axial high. At increasing distance from the hotspot the axial high broadens and deepens forming a distinctive transitional axial morphology (TAM). The axis in this transitional region is typically a broad zone (∼20 km wide) consisting of very rough volcanic and fault-generated topography. West of 95°W, this TAM evolves into a 20–40 km wide, 400–1500 m deep axial valley typical of the slow spreading Mid-Atlantic Ridge (MAR). There is not an abrupt change from axial high to rift valley along the GSC, but a distinct TAM occurs over a distance of ∼200–300 km along-axis and is accompanied by a gravity-estimated crustal thickening of >1–2 km. The boundary between an axial high and this TAM is quite abrupt and occurs along a segment that is less than 9 km long. These changes in axial morphology are primarily caused by variations in magma supply along the GSC due to the entrainment and dispersal of plume mantle from the Galapagos hotspot. However, the changes in morphology are not symmetric about the Galapagos FZ at 91°W. The axial high topography extends farther east of the 91°W FZ than to the west, and the rift valley which develops west of 94°W is not found at comparable distances along the GSC east of the hotspot. Axial depth variations are also asymmetric across the 91°W FZ. This asymmetry in both morphology and axial depth variation is attributed to a full spreading rate increase along the GSC from 46 mm/yr at 97°W to 64 mm/yr at 85°W. Off-axis depth changes are symmetric about the 91°W FZ and suggest that 15–40% of on-axis depth variation is dynamically supported.
Marine bivalve molluscs of Svalbard

The Norwegian archipelago of Svalbard is situated between latitudes 74 and 81”N and longitudes 10 and 3YE, on the boundary of three seas: the Greenland, the Barents and the Arctic Sea. A significant part in the surface circulation is played by the Norwegian Current, a branch of the warm North Atlantic Current, passing into the West Spitsbergen Current which governs the hydrological regime off the archipelago’s west coast. The east coast is affected by masses of cold water, flowing south as the East Spitsbergen Current (Lee 1952) and the local Sorkapp Current (Tantsura 1959; Swerpel 1985) from the central part of the Arctic Basin. A persistent frontal zone is present within the area of interaction between the two water masses (Alekseyev 1959). Due to its bottom topography, complex coastline, and hydrological properties, the area off the southwest coast of Svalbard is regarded as the region with the most intricate environmental conditions in the Barents Sea.
Porosity reduction and crustal pore pressure development

The influence of porosity reduction processes on the hydrologic characteristics of the earth's crust is examined. We present a simple mathematical model that shows the effect of porosity reduction on pore pressure development in the crust. Pore pressure in excess of hydrostatic can be generated if porosity reduction rates are sufficiently high. Elevated pore pressure could in turn affect properties such as strength and seismic reflectivity. Indirect evidence from laboratory, theoretical, and field studies indicates that porosity reduction processes are active, or very likely to be so, in large portions of the crust. Porosity, permeability, and pore pressure in the earth's crust may well be time-dependent, even in regions not subjected to large deviatoric stresses.
Structure of the Ionosphere and Atmosphere of Saturn from Pioneer 11 Saturn Radio Occultation

During the flyby of Saturn by Pioneer 11 on September 1, 1979, radio occultation measurements of the ionosphere and upper neutral atmosphere were made near the terminator at latitudes 9.7° south and 11.6° south. The principal electron density peak of the ionosphere occurs at an altitude of about 1,800 km and has a magnitude of 11,400 cm−3, with a sharp lower peak of about 9,000 cm−3 at about 1,200 km. The scale height above the main peak corresponds to an exosphere temperature of about 1150 K for an H+ ionosphere. Ionization appears to extend to 30,000 km, with a broad peak of magnitude 7,000 cm−3 at an altitude of about 14,500 km, corresponding to the inner edge of the C ring. The low density of the lower portion of the ionosphere can probably be explained by ring shadowing and equatorial anomaly, and the relatively high densities about 30,000 km, if real, could be explained if densities of ∼105 exist at higher latitudes that are connected to the site of measurement by field lines and by plasmaspheric heating by the rings. In the neutral atmosphere, measurements were made to a pressure level of about 180 mbar, showing a temperature inversion region with a triple minimum. The temperature at the principal minimum at 60,344 km is 88±4 K at a pressure of 74 mbar, and there is a prominent minimum about 80 km above the principal one. Comparisons with the temperature structure derived from the infrared radiometer data (Ingersoll et al., this issue) suggest that the helium fraction in the Saturnian atmosphere is 10±4%.
Harvesting Effects on Long‐Term Changes in Nutrient Pools of Mixed Oak Forest

The effects of sawlog harvesting (SAW) vs. whole-tree harvesting (WTH) on C and nutrient budgets of a mixed oak forest near Oak Ridge, TN, were assessed by sampling soils and vegetation just prior to and 15 yr after harvesting. Fifteen years after harvest, large woody residues in the SAW treatment lost >80% of their mass and nutrient content. Greater concentrations of Ca, K, and Mg were found in both foliage and soils in the SAW treatment than in the WTH treatment, but there were no signs of deficiency in these nutrients and no differences in growth due to treatment. There were no declines in exchangeable Ca{sup 2+} in the WTH treatment, and the increases in soil exchangeable Ca{sup 2+} pools in the SAW watersheds were approximately equal to the amount of Ca{sup 2+} released by decomposing residues. On the other hand, no treatment effects on soil C, vegetation biomass, species composition, vegetation N or P concentration, soil bulk density, or soil N were found 15 yr after treatment. Contrary to what has been speculated on regarding the basis of nutrient budgets, this study showed no detrimental effects of WTH on productivity or soil nutrient status (i.e., reductions from preharvest conditions). more » The results did show, however, that nutrients (especially Ca) from logging residues are largely retained in soils and reflected in elevated foliar nutrient concentrations. « less
VOTING WITH THEIR FEET: POPULATION TRENDS AND POLICY-MAKING IN THE FREE STATE

ABSTRACT Apartheid planning significantly influenced settlement patterns and urbanisation trends in South Africa. In many cases, black urbanisation was channelled to former homeland areas. With the demise of apartheid and the normalisation of black urbanisation, new trends started to emerge. This paper examines post-apartheid demographic trends in the Free State and argues that these aspects should be more rigorously considered in future regional planning. In essence, homeland growth has been replaced by the growth in small and medium-sized towns—mainly due to farm worker urbanisation. Despite this trend, large numbers of people are still residing in former homeland areas. The cultural connection with Lesotho also results in an influx of Lesotho citizens to the Free State. HIV/AIDS is and will remain prominent in the Free State's future demographic trends. White people are also leaving the Free State in large numbers.
Agricultural trends in India, 1891-1947: output, availability, and productivity

bondage (p. 29). To him means were as important as ends. Moreover, truth with him was God. He could not barter away truth for anything" (p. 156). As editor and manager, Gandhi supervised almost every facet of operation. He was prompt in answering business communications. His letters were "superb. " His accounting "meticulous. " "From type setting to printing, from packing to posting, from collection of subscription to over-all budgeting, he had a hand" (p. 100). He never "hit below the belt" even when unfairly attacked. No subject was too insignificant for his pen: "Louis Fischer . said that Gandhiji would attach equal importance to a letter written to President Roosevelt as much to an article on the subject of rape" (p. 79). His writings set a new style for both Gujarati and English, in India. Except for the early years in South Africa, when he edited Indian Opinion, Gandhi abjured all advertisement. He looked upon it as a curse that soiled newspapers. However, if a product was worthwhile, his papers publicized it without charge. The chapter "Liberty of the Press" is of some interest. Gandhi championed freedom of the press most of his life. Yet when freedom came in 1947 and Indian papers exaggerated news of communal violence, Gandhi advocated banning such papers. "He earlier approached the editors 'to see that false report or report likely to excite the public was not published in their newspapers. ' But these requests were of no avail In desperation he said: 'The kind of stuff that was read out to him (from press) should never be allowed to be published. Such newspapers should be banned! '" (p. 148). Naturally, Mr. Bhattacharyya sees no contradition in this. He explains it away by saying: "He (Gandhi) was all for press liberty, excepting the liberty to commit a crime. Mischievous papers, if these did disservice to the community and the country, should be banned. He had no compromise on that issue. It was no infringement of the liberty of Press" (p. 148). But, the crucial question is, who defines "disservice to the community and country? " This the author leaves unanswered. Another interesting question left unanswered by Bhattacharyya concerns the editorial policy of Harijan, which was started in JOURNAL OF ASIAN STUDIES
Polyphasic hydrothermal and meteoric fluid regimes during the growth of a segmented fault involving crystalline and carbonate rocks (Barcelona Plain, NE Spain)

A polyphasic tectonic-fluid system of a fault that involves crystalline and carbonate rocks (Hospital fault, Barcelona Plain) has been inferred from regional to thin section scale observations combined with geochemical analyses. Cathodoluminescence, microprobe analyses and stable isotopy in fracture-related cements record the circulation of successive alternations of hydrothermal and low-temperature meteoric fluids linked with three main regional tectonic events. The first event corresponds to the Mesozoic extension, which had two rifting stages, and it is characterized by the independent tectonic activity of two fault segments, namely southern and northern Hospital fault segments. During the Late Permian-Middle Jurassic rifting, these segments controlled the thickness and distribution of the Triassic sediments. Also, dolomitization was produced in an early stage by Triassic seawater at shallow conditions. During increasing burial, formation of fractures and their dolomite-related cements took place. Fault activity during the Middle Jurassic–Late Cretaceous rifting was localized in the southern segment, and it was characterized by hydrothermal brines, with temperatures over 180°C, which ascended through this fault segment precipitating quartz, chlorite, and calcite. The second event corresponds to the Paleogene compression (Chattian), which produced exhumation, folding and erosion, favouring the percolation of low-temperature meteoric fluids which produced the calcitization of the dolostones and of the dolomite cements. The third event is linked with the Neogene extension, where three stages have been identified. During the syn-rift stage, the southern segment of the Hospital fault grew by tip propagation. In the relay zone, hydrothermal brines with temperature around 140°C upflowed. During the late postrift, the Hospital fault acted as a unique segment and deformation occurred at shallow conditions and under a low-temperature meteoric regime. Finally, and possibly during the Messinian compression, NW-SE strike-slip faults offset the Hospital fault to its current configuration.
Status of Riparian Ecosystems in the United States

: An attempt was made to review all available data on the extent and status of riparian ecosystems in the U.S.A. This report presents a synthesis of the findings, including some estimates of how much land was originally covered by woody riparian vegetation, and how much remains in that condition today. A synopsis of information is presented on the status of riparian ecosystems in each of 10 regions: California, Pacific Northwest, Rocky Mountain, Arid Southwest, Plains-Grasslands, Lake States, Corn Belt, Mississippi Delta, Northeast-Appalachian, and Southeast. Woody riparian plant communities once covered an estimated 75 to 100 million acres of land in the contiguous 48 states. Mankind has converted at least two-thirds of that nationwide acreage to other non-forest land uses and it is estimated that only 25 to 35 million acres of riparian plant communities remain in a near natural condition. Across the country, loss of riparian acreages is directly attributable to water resource development (especially channel modification and water impoundment), floodplain clearing for agriculture, and urbanization. In many states of the arid west, the midwest, and the lower Mississippi alluvial valley, riparian vegetation has been reduced in area by more than 80 percent. Riparian woodlands are one of this country's most heavily modified natural vegetation types.
1998 eruption of axial volcano: Multibeam anomalies and sea‐floor observations

Lava flows erupted during the January/February 1998 seismic swarm at Axial Volcano on the Juan de Fuca Ridge have been identified by differencing of pre‐ and post‐event multibeam bathymetric surveys and by seafloor observations. A sheet flow more than 3 km in length and 500–800 m wide erupted from the uppermost south rift is the site of a robust hydrothermal system. 1998 lavas occur over about 9 km of the upper south rift zone, or about 20% of the along‐axis length of the seismicity event (∼50 km). The estimated volume of lava erupted is 18‐76 ×106 m³ for the extrusion and 100‐×106 m³ for the intrusion. The total volume is consistent with the volume from modeling of seafloor strain measurements recorded during the event.
Les changements de la végétation de la région Méditerranéenne durant le Pliocène et le Quaternaire en relation avec l'histoire du climat et de l'action de l'homme

L'analisi pollinica ha dimostrato che durante il Pliocene inferiore un primo cambiamento della vegetazione nei territori del Mediterraneo occidentale e avvenuto intorno a 3,2 milioni di anni fa a causa della comparsa di un clima a siccita estiva. Verso 2,3 milioni di anni fa si manifesta una prima comparsa di aggruppamenti steppici, indicatori del massimo di siccita, che si correla esattamente con la piu antica fase glaciale artica, mentre durante il Pleistocene inferiore compaiono delle fasi steppiche a determinismo sia xerico che termico. Durante il Pleistocene medio, poco conosciuto, i resti di microfossili indicano una estensione della vegetazione tipicamente mediterranea per una breve durata, per lo piu esclusivamente in corrispondenza di brevi flessioni climatiche. Nel Pleistocene superiore, alcune fasi aride a vegetazione mediterranea corrispondono a un clima piu umido e meno freddo che nell'Europa non mediterranea. Infine, anche se le fluttuazioni climatiche della fine dell'ultimo glaciale hanno p.