Formation and emergence of ICT clusters in India: the case of Bangalore and Hyderabad

Since the 1990s, information and communication technologies clusters (ICT clusters) have been created in developing countries, especially in Asia, where India is one of the most dynamic countries. Bangalore and Hyderabad are two important examples of Indian clusters. This article aims to analyze the characteristics of ICT clusters, Indian policies to develop IC technologies, the formation and emergence of the Bangalore and Hyderabad clusters and their impacts on the population, as well as to show that ICT development is a strategic issue for India but does not benefit all of its population.     

地球物理学方法在区分多年冻土区咸水层和淡水融化层中的应用

Direct current resistivity and ground penetrating radar surveys were employed to obtain the value of the resistivity and dielectric constant in the brine near the Barrow, Alaska. The geophysical surveys were undertaken together with the permafrost drilling program for the measuring of the ground temperature regime and for the core sampling. The sampled cores were measured for their physical and chemical properties in the laboratory under different temperature conditions (-60 to 20 ℃). Laboratory results support field observations and led to the development of a technique for distinguishing freshwater taliks and brine layers in permafrost. These methods were also employed in freshwater taliks near Council,Alaska. The electrical resistivity is a powerful and sensitive parameter for brine detection. However, the resistivity is a less sensitive indicator of the soil type or water content under highly saline conditions.High frequency dielectric constant is an ideal second parameter for the indication of the soil type, liquid water content and other physical properties. The imaginary part of the dielectric constant and resistivity have a significant dependence upon salinity, i.e. upon freezing temperature. The ground temperature regime and the freezing point of the brine layer are important parameters for studying the electric properties of permafrost terrain.     

Continental subduction and exhumation of high-pressure rocks: insights from thermo-mechanical laboratory modelling

Thermo-mechanical physical modelling of continental subduction is performed to investigate the exhumation of deeply subducted continental crust. The model consists of two lithospheric plates made of new temperature sensitive analogue materials. The lithosphere is underlain by liquid asthenosphere. The continental lithosphere contains three layers: the weak sedimentary layer, the crust made of a stronger material, and of a still stronger lithospheric mantle. The whole model is subjected to a constant vertical thermal gradient, causing the strength reduction with depth in each lithospheric layer. Subduction is driven by both push force and pull force. During subduction, the subducting lithosphere is heating and the strength of its layers reduces. The weakening continental crust reaches maximal depth of about 120 km and cannot subduct deeper because its frontal part starts to flow up. The subducted crust undergoes complex deformation, including indicated upward ductile flow of the most deeply subducted portions and localised failure of the subducted upper crust at about 50-km depth. This failure results in the formation of the first crustal slice which rises up between the plates under the buoyancy force. This process is accompanied by the delamination of the crustal and mantle layers of the subducting lithosphere. The delamination front propagates upwards into the interplate zone resulting in the formation of two other crustal slices that also rise up between the plates. Average equivalent exhumation rate of the crustal material during delamination is about 1 cm/year. The crust-asthenosphere boundary near the interplate zone is uplifted. The subducted mantle layer then breaks off, removing the pull force and thereby stopping the delamination and increasing horizontal compression of the lithosphere. The latter produces shortening of the formed orogen and the growth of relief. The modelling reveals an interesting burial/exhumation evolution of the sedimentary cover. During initial stages of continental subduction the sediments of the continental margin are dragged to the overriding plate base and are partially accreted at the deep part of the interplate zone (at 60-70 km-depth). These sediments remain there until the beginning of delamination during which the pressure between the subducted crust and the overriding plate increases. This results in squeezing the underplated sediments out. Part of them is extruded upwards along the interplate zone to about 30-km depth at an equivalent rate of 5-10 cm/year.     

Diagnosing drought using the downstreamness concept: the effect of reservoir networks on drought evolution

ABSTRACT

To effectively manage hydrological drought, there is an urgent need to better understand and evaluate its human drivers. Using the “downstreamness” concept, we assess the role of a reservoir network in the emergence and evolution of droughts in a river basin in Brazil. In our case study, the downstreamness concept shows the effect of a network of reservoirs on the spatial distribution of stored surface water volumes over time. We demonstrate that, as a consequence of meteorological drought and recovery, the distribution of stored volumes became spatially skewed towards upstream locations, which affected the duration and magnitude of hydrological drought both upstream (where drought was alleviated) and downstream (where drought was aggravated). The downstreamness concept thus appears to be a useful entry point for spatiotemporally explicit assessments of hydrological drought and for determining the likelihood of progression from meteorological drought to a human-modified hydrological drought in a basin.     

Automatic identification of continuous or non-continuous evolution of landslides and quantification of deformations

Landslides - Nowadays, the 3D modelling of surfaces is widely used to provide point clouds in geosciences. To study the evolution of landslides, many point clouds are available but post-processing...     

Estuarine flooding in urban areas: enhancing vulnerability assessment

The assessment of vulnerability provides valuable knowledge in the risk assessment steps of a risk governance process. Given the multiscale, multilevel, and multisectorial aspects of flood risk, the diversified entities that directly and indirectly intervene in risk management require specific outputs from the assessment studies. Urban areas in estuarine margins are particularly exposed and vulnerable to flooding. Such interface conditions are found in the Old City Centre of the Seixal, located in the Tagus estuary, Portugal. Here, two distinct methodologies were applied for the assessment of territorial vulnerability. A regional, lower-scale, methodology explores the application of the statistical procedure based on the SoVI^® at the statistical block level. A second, local and higher-scale, methodology is based in data collected through field matrices at the building and statistical sub-block level. Comparison of results revealed that the lower-scale assessment provides information on the vulnerability drivers at the regional and municipal level. Nevertheless, only at a higher-scale, it is possible to characterize and differentiate the smaller geographical units of analysis that compose the Old City Centre of Seixal. The lower-scale vulnerability assessment allows a strategic response, based on adaptation measures such as spatial planning, institutional capacity building and public awareness. The local level assessment provides more accurate knowledge to support local emergency planning and the allocation of operational and material resources at the urban level. Nevertheless, rather than antagonistic, both models can be considered as complementary, having in mind the requirements of an holistic flood risk governance model.

     

Bismuth selenides from St. Andreasberg,Germany: an oxidised five-element style of mineralisation and its relation to post-Variscan vein-type deposits of central Europe

International Journal of Earth Sciences - Carbonate veinlets at Roter Bär, a former underground mine in the polymetallic St. Andreasberg vein district of the Harz Mountains, Germany, host...     

Testing models of step formation against observations of channel steps in a steep mountain stream

Steep streams often feature a step-pool morphology where the steps determine channel stability and dissipate the stream's energy, and thus are important for local flow hydraulics and bedload transport. Steps also play a key-role for the coupling of channels and adjacent hillslopes by controlling hillslope stability. Although step-pool systems have been investigated in various modelling and experimental efforts, the processes of step formation and destruction remain under debate. Theories of step formation consider a wide range of dominant drivers and fall into three groups favouring hydraulic controls ( HC ), granular interactions during flow ( GI ) or random drivers ( RD ) as relevant factors for step location. A direct evaluation of these models with field observations is challenging, as step formation cannot be directly observed. Based on the physical mechanisms of the various formation models we derive diagnostic morphometric parameters and test them with a field data set from a steep stream in Switzerland. Our results suggest that one class of alluvial steps form due to jamming in narrow and narrowing sections of the channel, while steps in wide and widening sections form around rarely mobile keystones. These two models of step formation apply in our study reach at the same time in different locations of the channel. A third class of steps is forced by logs. Such steps are typically located close to the original growth position of the tree and therefore reflect strong channel-hillslope coupling. Wood-forced steps make up a minor fraction of the step population, but contribute significantly to the cumulative step height and are therefore relevant to reach-scale flow resistance of the channel. © 2019 John Wiley & Sons, Ltd.     

Inorganic nitrogen uptake and related enzymatic activity in the seagrass Zostera noltii

The preferential inorganic nitrogen source for the seagrass Zostera noltii was investigated in plants from Ria Formosa, South Portugal. Rates of ammonium and nitrate uptake were determined at different concentrations of these nutrients (5, 25 and 50 μm ), supplied simultaneously (NH₄NO₃) or separately (KNO₃ and NH₄Cl). The activity of the enzymes nitrate reductase (NR) and glutamine synthetase (GS) was also assessed. The results showed that ammonium is the preferential inorganic nitrogen source for Z. noltii, but, in the absence of ammonium, the species also has a high nitrate uptake capacity. The simultaneous availability of both inorganic nitrogen forms enhanced the uptake rate of ammonium and decreased the uptake rate of nitrate compared to when only one of the nitrogen forms was supplied. The activity of both enzymes was much higher in the leaves than in the roots, highlighting the importance of the leaves as primary reducing sites in the nitrogen assimilation process.