Miracle-dz/UniFAR-FTUs huggingface dataset:
Drape corrections of aeromagnetic data using wavelets

Aeromagnetic surveys are commonly flown at a constant height above the terrain to minimise the magnetic effects of variable terrain clearance. This is known as drape flying. However, in mountainous regions it is often not operationally feasible to perform a drape survey. Instead, the survey is flown at a constant barometric height and the draped magnetic data are calculated numerically using a level-to-drape continuation operator. Existing techniques for this calculation include the chessboard and Taylorseries methods. An alternative method described here, based on the wavelet transform, approaches the problem by representing the continuation integral using a family of wavelet basis-functions localised in both space and frequency. This allows the generation of a set of coefficients that can be efficiently applied to the wavelet transform of the signal. The wavelet approach can be used for both 1D and 2D signals. If the drape surface is closer to the ground than the barometric survey height, a major difficulty in the drape correction is the control of noise. This is achieved in the wavelet domain by using a locally-adaptive, exponential noise-reduction filter which can be designed based on the wavelet coefficients. The method can be extended in some cases to generate draped images below the ground surface that can be used to sharpen images of magnetic basement in sedimentary basins. The wavelet method is compared with conventional techniques using data from the Edge Hills region in Canada and the Browse Basin in Western Australia. In this study, the wavelet approach combined with the exponential smoothing filter produces sharper images than either the chessboard or Taylor-series methods.
The role of phosphorus on eutrophication: a historical review and future perspectives

The eutrophication phenomenon is one of the main challenges regarding the ecological quality of surface waters, caused mainly by leaching of fertilizer from agriculture and by discharge of wastewater containing high amounts of phosphorus. This is a global environmental problem, which does not have yet a suitable solution. European Union developed and is implementing the Water Framework Directive (WFD-2000/60/EC), which requires the restoration of eutrophic water bodies quality until 2015; however, derogations have been claimed when eutrophication is the main pressure due to the complexity into recovery the degraded waters. In this context, this review aims to give a general overview of the historical evolution of phosphorus, its uses and consequently its role on eutrophication. Moreover, the main methodologies and some commercial products used for phosphorus precipitation are discussed. Since the main treatments focus on phosphorus precipitation, the scarcity of this mineral source is pointed out. More than an overview, this review leaves the question how many more years do we have enough mineral phosphorus reserves to guarantee enough food production.
The Great Lakes-to-Florida Highway: A Politics of Road Space in 1920s West Virginia and Virginia

Americans spend much of their lives on highways, yet few understand the complex geographies behind their development. Politics, scale, and geographical imagination are indelibly intertwined in the process of boosting and building roads. In recent years, geographers have encouraged research on past mobilities, including road space. This article discusses efforts to link the Great Lakes and Florida through West Virginia and southwestern Virginia during the 1920s, a transitional period in the history of road development when the numbered U.S. Highway System replaced historic-scenic named trails. Southern West Virginia and southwestern Virginia are often considered remote and isolated, but they were viewed as essential links in the Great Lakes-to-Florida Highway and the Cleveland-Marietta-Asheville-Florida Highway.
Basanites related to Late Eocene extension from NE Oman

Six small basanite intrusions were emplaced into the allochthonous Batain Nappes of NE Oman along approximately north–south to NNW–SSE lineaments. They contain olivine, clinopyroxene, plagioclase, analcite, ulvöspinel and apatite ± biotite ± calcite. The basanites are primitive, with Mg numbers (100Mg/(Mg + Fe2+)) from 63.18 to 69.37, and are nepheline normative. Compositional variation suggests fractionation of olivine and clinopyroxene. Thermobarometric studies on rare spinel lherzolite xenoliths suggests re-equilibration at shallow depth. 143Nd/144Nd and 87Sr/86Sr isotopic data and REE modelling indicate that the magmas were formed by 1–2% melting of an ocean-island basalt (OIB)-like source containing about 3–4% garnet. Deviations from OIB are explained by mobilization of incompatible elements from potassic layers in the lithosphere during ascent. Sedimentological studies and three new whole-rock Ar/Ar ages (39.77 ± 0.26, 37.63 ± 0.46 and 36.51 ± 0.21 Ma, Lutetian to Priabonian time) suggest intrusion during maximum deepening of the Abat Trough. Movements were related to dextral strike-slip movement along major tectonic structures during the initial stages of the opening of the Gulf of Aden. The basanites were formed by decompressional melting of an asthenospheric mantle source facilitated by thinned lithosphere and depression of the solidus by H2O- and CO2-rich fluids.
Costo de transacción y estrategia corporativa

Resumen: En este trabajo se hara una presentacion de los elementos teoricos propuestos en los planteamientos hechos por R.Coase (1937, 1960, 1994) y O. Williamson (1981, 1991); destacando sus contribuciones analiticas en el campo de la Estrategia Empresarial Corporativa, ademas de identificar sus posibles limitaciones conceptuales y metodologicas.Abstract:This paper will present the theoretical elements proposed by Coase (1937,1960,1994) and Williamson (1981,1991); remarking their analytical contributions in the field of Corporative Strategy. Additionally, this work identifies its possible conceptual and methodological limitations.
Tectonic evolution of the central Annapurna Range, Nepalese Himalayas

The metamorphic core of the Himalayan orogen, or Greater Himalayan sequence, is a northward tapering prism bound at the bottom by a N dipping family of thrust faults (the Main Central thrust system) and at the top by a N dipping family of normal faults (the South Tibetan detachment system). Research in the central Annapurna Range of Nepal demonstrates a close temporal and spatial association between contractional and extensional deformation on these bounding fault systems and within the metamorphic core throughout much of the Early Miocene. The Main Central thrust system is represented here by a 2- to 3-km-thick zone of high strain that developed during two or more episodes of movement. Most of its displacement was concentrated along the Chomrong thrust, a sharp, late-metamorphic discontinuity that places middle amphibolite facies rocks of the Greater Himalayan sequence on top of lower amphibolite facies rocks of the Lesser Himalayan sequence. The earliest demonstrable movement on this thrust system occurred ∼22.5 Ma; the most recent movement may be as young as Pliocene. The oldest element of the South Tibetan detachment system in this area is the Deorali detachment, which appears to have been active at the same time as the earliest shortening structures of the Main Central thrust system. Fabrics related to the Deorali detachment are disrupted by a previously unrecognized, SW vergent, thrust structure, the Modi Khola shear zone. The effect of this structure, which is constrained to be between 22.5 and 18.5 Ma, was to shorten rock packages that had been extended previously during movement on the Deorali detachment. Transition back to a local extensional regime after 18.5 Ma was marked by development of the Machhupuchhare detachment and related splays. Geologic evidence for rapid, two-way transitions between contraction and extension in the Annapurna Range indicates that extensional deformation in convergent settings does not only represent gravitational collapse at the end of an orogenic cycle; it also appears to be an important factor in mountain range development.
Law Dome CO2, CH4 and N2O ice core records extended to 2000 years BP

New measurements of atmospheric greenhouse gas concentrations in ice from Law Dome, Antarctica reproduce published Law Dome CO2 and CH4 records, extend them back to 2000 years BP, and include N2O. They have very high air age resolution, data density and measurement precision. Firn air measurements span the past 65 years and overlap with the ice core and direct atmospheric observations. Major increases in CO2, CH4 and N2O concentrations during the past 200 years followed a period of relative stability beforehand. Decadal variations during the industrial period include the stabilization of CO2 and slowing of CH4 and N2O growth in the 1940s and 1950s. Variations of up to 10 ppm CO2, 40 ppb CH4 and 10 ppb N2O occurred throughout the preindustrial period. Methane concentrations grew by 100 ppb from AD 0 to 1800, possibly due to early anthropogenic emissions.
Earliest Fish Remains from the Lake Malawi Basin, Malawi, and Biogeographical Implications

ABSTRACT Fossil elements belonging to fishes were recovered from the Pliocene Chiwondo Beds in the Malawi Rift. This is our first knowledge of fishes from Lake Malawi. The Chiwondo Bed fishes can be assigned to living taxa including lungfish (Protopterus), catfishes (Bagridae, Claroteidae and Clariidae), cichlids, and a single tooth referred to tigerfish (Hydrocynus). Although small and taphonomically biased, the assemblage shows several taxonomic differences compared with the modern Lake Malawi fauna. Most of the geographic and taxonomic affinities of the assemblage are with fishes from the African East Coast Province rivers, whereas the modern lake fauna primarily has affinities to the Zambezi River system. The Chiwondo fish assemblage contributes new information on Plio-Pleistocene eastern/southern African biogeography and waterways, and how these may have influenced faunal movements between eastern and southern Africa.
Seasonal variation of surface and vertical profile of aerosol properties over a tropical urban station Hyderabad, India

One year measurement of vertical profiles of volume backscatter and extinction coefficient, aerosol optical depth (AOD), mass concentration of black carbon (BC) and composite aerosol along with thermodynamic structure of the atmosphere has been carried out over an urban tropical location of Hyderabad(17.47°N, 78.58°E), India, during April 2009 to March 2010. The mean mixing layer height (MLH) exhibits large seasonality exceeding 4 km in pre‐monsoon period whereas in winter it comes down to ~1.5 km with an annual mean value of 2.35 ± 1.02 km. Surface BC mass fraction (FBC) shows marked seasonal variation from winter (13 ± 1.9%), pre‐monsoon (8.19 ± 2.16%), monsoon (7.3 ± 1.8%) to post‐monsoon (11.8 ± 0.18%). The profiles of volume backscatter and extinction coefficients reveal presence of elevated aerosol layers from 2 to 4 km and strong oscillations during pre‐monsoon (March–May) and monsoon (June–September) seasons, respectively, while in post‐monsoon (October–November) and winter (December–February), the aerosols are well within the lower boundary layer and also exhibit a drastic decrease with increasing altitude. These elevated aerosol layers and vertical distribution appear to be closely linked to the thermodynamic structure of the atmosphere. The aerosol optical properties in conjunction with air mass back trajectory analysis indicate that the observed elevated aerosol layers during pre‐monsoon and monsoon could contain significant fraction of coarse mode particles with a mix of dust and marine aerosols. Further analysis reveals that the aerosols within atmospheric boundary layer (ABL) dominate the column aerosol loading with ABL‐AOD contributing to ~77.7 ± 17.0%, with significant seasonal variation from winter (86.2 ± 13.1%), pre‐monsoon (76.6 ± 12.8%), monsoon (54.2 ± 15.6%) to post monsoon (80.8 ± 14.8%). Seasonal variation of ABL‐AOD and BC mass fraction follows similar pattern in the ABL indicating that BC may be an important contributor to the ABL aerosol loading.
Road extraction from high-resolution remote sensing images based on characteristics

In this paper, an automated road extraction from high-resolution remote sensing images method based on road synthetical characteristics is presented. First, spectral property, geometric property and textural property of road class have been considered and a road clustering model has been established. Second, mathematical morphology has been applied to extract road centerlines. Experiments prove that the model of this paper could describe the features of road well and accurately identify the road class from high-resolution remote sensing images.
Do Eddies Play a Role in the Momentum Balance of the Leeuwin Current

Abstract The Leeuwin Current is a poleward-flowing eastern boundary current off the western Australian coast, and alongshore momentum balance in the current has been hypothesized to comprise a southward pressure gradient force balanced by northward wind and bottom stresses. This alongshore momentum balance is revisited using a high-resolution upper-ocean climatology to determine the alongshore pressure gradient and altimeter and mooring observations to derive an eddy-induced Reynolds stress. Results show that north of the Abrolhos Islands (situated near the shelf break between 28.2° and 29.3°S), the alongshore momentum balance is between the pressure gradient and wind stress. South of the Abrolhos Islands, the Leeuwin Current is highly unstable and strong eddy kinetic energy is observed offshore of the current axis. The alongshore momentum balance on the offshore side of the current reveals an increased alongshore pressure gradient, weakened alongshore wind stress, and a significant Reynolds stress exerte.
Search for the Associated Production of a Higgs Boson and a Top Quark Pair in Multilepton Final States with the ATLAS Detector The ATLAS Collaboration

The Yukawa coupling of the Higgs boson to the top quark is a key parameter of the Standard Model, and can be constrained using the associated production process pp → tt̄H + X . A search for this process using final states with multiple leptons, primarily targeting the decays H → WW ∗ and H → ττ, has been performed using 13.2 fb−1 of data recorded by the ATLAS detector in 2015 and 2016 at a center of mass energy √ s = 13 TeV. The best-fit value of the ratio of observed and Standard Model cross sections is 2.5 ± 0.7 (stat) +1.1 −0.9 (syst), and an upper limit on this ratio of 4.9 (2.3 expected) is found at 95% confidence level. © 2016 CERN for the benefit of the ATLAS Collaboration. Reproduction of this article or parts of it is allowed as specified in the CC-BY-4.0 license.
A spatio-temporal video analysis system for object segmentation

A robust system for the extraction of temporal coherent masks of physical meaningful objects in video sequences is proposed. The system is based on six modules combining three-dimensional nonlinear diffusion filters, morphological operators and a region merging technique that exploit information from previous frames and motion compensation. An initial mask is produced using the semiautomatic segmentation tool for still images. The video sequence is then filtered to remove high frequency components due to noise and texture in the spatial domain and to smooth abrupt changes in the temporal domain. Prefiltered sequences are passed to the main processing unit to initialize the segmentation using morphological tools. Here information from the YUV and HSV color spaces is used. Highly accurate segmentation areas defined by watershed lines are fused together to build larger regions representing objects in the scene. This process is carried out by a region merger module which uses information from the previously segmented frame and motion compensation. Several computer simulations were conducted to assess the performance of the proposed system.
Hydrogeomorphic processes of thermokarst lakes with grounded‐ice and floating‐ice regimes on the Arctic coastal plain, Alaska

Thermokarst lakes cover > 20% of the landscape throughout much of the Alaskan Arctic Coastal Plain (ACP) with shallow lakes freezing solid (grounded ice) and deeper lakes maintaining perennial liquid water (floating ice). Thus, lake depth relative to maximum ice thickness (1·5–2·0 m) represents an important threshold that impacts permafrost, aquatic habitat, and potentially geomorphic and hydrologic behaviour. We studied coupled hydrogeomorphic processes of 13 lakes representing a depth gradient across this threshold of maximum ice thickness by analysing remotely sensed, water quality, and climatic data over a 35‐year period. Shoreline erosion rates due to permafrost degradation ranged from < 0·2 m/year in very shallow lakes (0·4 m) up to 1·8 m/year in the deepest lakes (2·6 m). This pattern of thermokarst expansion masked detection of lake hydrologic change using remotely sensed imagery except for the shallowest lakes with stable shorelines. Changes in the surface area of these shallow lakes tracked interannual variation in precipitation minus evaporation (P − EL) with periods of full and nearly dry basins. Shorter‐term (2004–2008) specific conductance data indicated a drying pattern across lakes of all depths consistent with the long‐term record for only shallow lakes. Our analysis suggests that grounded‐ice lakes are ice‐free on average 37 days longer than floating‐ice lakes resulting in a longer period of evaporative loss and more frequent negative P − EL. These results suggest divergent hydrogeomorphic responses to a changing Arctic climate depending on the threshold created by water depth relative to maximum ice thickness in ACP lakes. Copyright © 2011 John Wiley & Sons, Ltd.
Combined EDL-Mobility Planning for Planetary Missions

between the performance of each system or attempt to minimize overall system and mission risk. A major challenge is that the performance of EDL is inherently uncertain due to uncertainty in the aerodynamics, atmospheric variability and dispersions in the spacecraft position and velocity as it enters the atmosphere. The surface mobility performance, is however, more predictable with the performance issues being more related to obstacle avoidance, pathplanning and mission duration. The analysis results for EDL such as the landing footprint are described using PDFs (Probability Density Functions) obtained by using physics-based Monte-Carlo simulations of the EDL process. The proposed approach rst builds a mobility cost-to-go map that encodes the driving cost of any point on the map to a science target location. The cost term in this cost-to-go map could include a variety of metrics such as traverse distance, drive time, wheel rotation slip on soft soil, and proximity to hazards. It then convolves the mobility cost-to-go map with the landing PDF given by the EDL system simulations to provide a histogram representation of the PDF of the driving cost. This can be used to evaluate the overall performance and risk of the mission as it combines the uncertainties in EDL performance with the more predictable mobility performance. By capturing the coupling between EDL and mobility explicitly, this analysis framework enables quantitative trade-os between EDL and mobility system performance, as well as characterizes mission risks in a statistical way. Simulation results are presented with a realistic Mars terrain data.
Waveform inversion of very long period impulsive signals associated with magmatic injection beneath

We use data from broadband seismometers deployed around the summit of Kilauea Volcano to quantify the mechanism associated with a transient in the flow of magma feeding the east rift eruption of the volcano. The transient is marked by rapid inflation of the Kilauea summit peaking at 22 μrad 4.5 hours after the event onset, followed by slow deflation over a period of 3 days. Superimposed on the summit inflation is a series of sawtooth displacement pulses, each characterized by a sudden drop in amplitude lasting 5–10 s followed by an exponential recovery lasting 1–3 min. The sawtooth waveforms display almost identical shapes, suggesting a process involving the repeated activation of a fixed source. The particle motion associated with each sawtooth is almost linear, and its major swing shows compressional motion at all stations. Analyses of semblance and particle motion are consistent with a point source located 1 km beneath the northeast edge of the Halemaumau pit crater. To estimate the source mechanism, we apply a moment tensor inversion to the waveform data, assuming a point source embedded in a homogeneous half-space with compressional and shear wave velocities representative of the average medium properties at shallow depth under Kilauea. Synthetic waveforms are constructed by a superposition of impulse responses for six moment tensor components and three single force components. The origin times of individual impulses are distributed along the time axis at appropriately small, equal intervals, and their amplitudes are determined by least squares. In this inversion, the source time functions of the six tensor and three force components are determined simultaneously. We confirm the accuracy of the inversion method through a series of numerical tests. The results from the inversion show that the waveform data are well explained by a pulsating transport mechanism operating on a subhorizontal crack linking the summit reservoir to the east rift of Kilauea. The crack acts like a buffer in which a batch of fluid (magma and/or gas) accumulates over a period of 1–3 min before being rapidly injected into a larger reservoir (possibly the east rift) over a timescale of 5–10 s. The seismic moment and volume change associated with a typical batch of fluid are approximately 1014 N m and 3000 m3, respectively. Our results also point to the existence of a single force component with amplitude of 109 N, which may be explained as the drag force generated by the flow of viscous magma through a narrow constriction in the flow path. The total volume of magma associated with the 4.5-hour-long activation of the pulsating source is roughly 500,000 m3 in good agreement with the integrated volume flow rate of magma estimated near the eruptive site.
Are monoterpene emissions influenced by humidity?

Monoterpene mixing ratios and fluxes were measured above a ponderosa pine plantation in the Sierra Nevada mountains from July to October 1998. Data were obtained during a variety of weather regimes including periods of extreme heat and dryness as well as during rain. Monoterpene emissions were highly elevated during and after the rain events, and the expected exponential increase of emissions with temperature did not occur during extremely hot and dry conditions, suggesting an influence of ambient humidity levels on monoterpene emissions. Therefore, we propose a modified emission algorithm based on responses to both temperature and humidity.
Estimation of uncertainty for massive Porites coral skeletal density

Previous studies have not demonstrated the estimate errors in growth parameters (skeletal density, extension rate and calcification rate) for massive coral skeletons. In order to discuss the variability of coral skeletal growth, it is crucial for quantitative evaluation of the parameters with errors. We report the protocol of calculating errors as combined standard uncertainty for coral skeletal density (uρSA) based on ISO/IEC Guide 98-3 (2008). We applied the non-destructive transparent X-ray 2-D imaging scanner, TATSCAN-X1, which enabled to quick and quantitative analysis of the uρSA parameters with digital procedures. We analyzed the annual skeletal density for massive Porites coral collected from Ishigaki Island. The skeletal densities changed from 1.45 to 1.70 g/cm 3 and uρSA were ca. 0.02 g/cm 3 . Our results indicated that the uρSA was derived from the combined effects of 78.5% from the standard uncertainty of deducing of analytical curve (u ln OD (Y)→ρ*t (X)) and 6.3% from that of the sample thickness error (utSA).