Miracle-dz/UniFAR-FTUs huggingface dataset:
Controls on ore metal ratios in granite-related ore systems: an experimental and computational approach

ABSTRACT Size and composition (bulk metal ratios) of magmatic hydrothermal mineral deposits are affected by a number of chemical and physical processes including the nature of the source region and mode of emplacement. At shallow levels, rising plumes of vapour bubbles + melt, and the advection of water through interconnected vapour bubbles, allows access of the magmatic aqueous phase to the upper reaches of a magma chamber. These processes are operative at shallow levels where low water solubility and high molar volume for water make these processes more efficient. Partitioning experiments suggest that oxygen fugacity-dependent crystal/melt partitioning of ore metals leads to different efficiencies of removal of Cu, W, and Mo from silicate melts into ore-forming aqueous fluids. For example, the Mo/W ratio in magmatic hydrothermal deposits should increase as the oxygen fugacity of the magma increases. Further, Cu should behave as a crystal-compatible element in H2O-undersaturated, sulfide-saturated felsic magmas with fO2 NNO + 1 due to the strong partitioning of Cu from the melt into pyrrhotite. Cycling of oxidised, hydrated, sulfidised and Cl-enriched oceanic crust into mantle can give rise to magmas that contain S but are oxidised (≥NNO). The combination of high oxidation state, relatively hydrous but shallow conditions and a high Cl/H2O ratio leads to saturation with respect to H2O early during crystallisation, and loss of a large proportion of magmatic Cu to the aqueous phase. Ores formed from these oxidised magmas also possess high Mo/W ratios due to the effect of oxygen fugacity on the sequestering of Mo vs W. In less oxidised magmas, Cu and Mo are partitioned into sulfides and Ti-bearing phases, respectively, resulting in lower efficiencies of removal of Cu and Mo from melts into aqueous fluids. Further, the partitioning of W into crystallising phases is reduced, producing a more efficient removal of W into ore-forming fluids. This ultimately leads to mineral deposits with higher W/(Mo + Cu) ratios relative to deposits associated with more oxidised systems. Silicic, high-F magmas with fO2 = NNO can be found in tensional environments (e.g. rocks associated with the Climax-type deposits of the Colorado Mineral Belt). High HF/H2O activity ratios in the source regions yield melts that evolve an aqueous phase late during crystallisation, leading to relatively low ratios of compatible/incompatible elements in the melt at H2O saturation.
Dynamics of ocean surface mixed layer variability in the Indian Ocean

We present a new methodology that allows quantifying the impact of individual terms of the temperature and salinity conservation within the mixed layer on mixed layer depth (MLD). The method is applied to output from an ocean general circulation model in the Indian Ocean to investigate variability and changes in MLD. On seasonal timescales and for most areas of the Indian Ocean variability of MLD is tightly linked to all thermohaline budget terms. In the Indian Ocean at approximately 20°S the MLD covaries with surface heat and freshwater fluxes on intraseasonal and interannual timescales. The geography of the region includes the Leeuwin Current, plus the tropical eastern Indian Ocean for interannual surface freshwater fluxes. The range of seasonal amplitudes of MLD variability varies with individual budget terms but is typically within 1 m/month to 100 m/month. The ocean footprints of an intraseasonal tropical cyclone, tropical and midlatitude seasonal temperature and salinity budgets and interannual variability associated with the Indian Ocean Dipole Mode are analyzed. The results reveal close relationships of the thermohaline budgets within the mixed layer with the variability of the MLD. The associated tendencies of changes in MLD are consistent with Argo and satellite-based observations of tendencies within the mixed layer and sea-surface temperature and salinity.
Update of the Spain02 gridded observational dataset for EURO‐CORDEX evaluation: assessing the effect of the interpolation methodology

Observational gridded products are commonly used to evaluate the performance of regional climate models. To this aim, gridded datasets should be comparable to the output of these models and, thus, should represent grid‐cell area‐averaged values and, whenever possible, they should be defined on the same spatial domains as the models, in order to avoid re‐gridding or re‐projection. In this study, we present an update of the Spain02 gridded observational dataset for daily precipitation and mean temperature building on the grids defined for the EURO‐CORDEX initiative. In order to assess and intercompare different interpolation approaches, we analysed (1) two standard methodologies (ordinary kriging and thin plate splines), (2) three horizontal resolutions: 0.11°, 0.22° and 0.44° (matching the rotated EURO‐CORDEX and ENSEMBLES grids), (3) two different approaches to guarantee either area‐averaged or point representativity of the resulting grid values and (4) including/excluding orography as a covariable in the interpolation procedure. Besides introducing the new gridded datasets, in this work we also present some preliminary results on the sensitivity of temperature and precipitation (both mean and extreme regimes) to all these factors.
The impact of neighbourhood and school environments on ethnic differences in body size in adolescence

Background: Ethnicity is associated with childhood obesity, with Black African origin girls in particular being more vulnerable to overweight and obesity than their White European peers. In the UK, ethnic minorities often live and attend school in poor urban areas which may influence their opportunity for physical activity and a healthy diet. Aim: To examine neighbourhood and school effects on ethnic differences in Body Mass Index (BMI) and waist circumference trends in adolescence. Methods: Multilevel analysis of longitudinal data on BMI and waist circumference [standard deviation scores (SDS)] from 3401 adolescents in the Determinants of Adolescent Social well-being and Health (DASH) Study (870 White UK, 778 Black Caribbean, 504 Nigerian/Ghanaian, 386 Other African, 418 Indian, and 445 Pakistani/Bangladeshi). Forty-nine London schools participated in the study and the same pupils were surveyed at 11-13yrs and 14-16yrs. Neighbourhood measures included deprivation, crime, and ethnic density; school measures included ethnic density, school socioeconomic status (SES) (academic performance, free school meals, unauthorised absence) and ethos. Individual and family characteristics were also examined (including dietary and physical activity measures, family SES, and parental overweight). Results: Between 11 and 16yrs ethnic differences in BMI emerged in boys and persisted in girls; compared to their White UK peers Black Caribbean and Nigerian/Ghanaian boys and girls, and Other African girls, had a greater mean BMI SDS. These patterns were not observed for waist circumference, signalling ethnic differences in fat distribution or body composition. The DASH pupils overall had large waists compared to the 1990 Growth Reference population. The ethnic minority pupils, with the exception of the Indians, were more likely to live in more deprived, higher crime, less green areas than their White UK peers. However the ethnic minority pupils often attended better performing schools than the White UK pupils. The overall variance in body size at neighbourhood level or school level was small (<4%), and area or school context measures had little or no effect on ethnic differences in body size. Individual characteristics (such as age, pubertal status, and skipping breakfast) and maternal overweight were strong correlates of body size but did not explain the ethnic differences observed. Conclusions: There were significant ethnic differences in BMI in adolescence, emergent in late adolescence for boys. Neighbourhood and school contexts did not explain the ethnic differences in BMI age trends.
Importance of space weathering simulation products in compositional modeling of asteroids: 349 Dembowska and 446 Aeternitas as examples

Abstract— Based on recent progress in simulating space weathering on asteroids using pulse‐laser irradiation onto olivine and orthopyroxene samples, detailed analyses of two of the A and R type asteroid reflectance spectra have been performed using reflectance spectra of laser‐treated samples. The visible‐near‐infrared spectrum of olivine is more altered than that of pyroxene at the same pulse‐laser energy, suggesting that olivine weathers more rapidly than orthopyroxene in space. The same trend can be detected from reflectance spectra of the asteroids, where the more olivine an asteroid has, the redder its 1 μm band continuum can become. Comparison of the 1 μm band continuum slope and the 2/1 μm band area ratio between the asteroids and olivine and pyroxene samples (including the laser‐treated ones) suggests that asteroids may be limited in the degree of space weathering they can exhibit, possibly due to the short life of their surface regolith. Their pyroxenes may also have a limited chemical composition range. Fitting the visible continuum shape and other parts of the spectra (especially the 2μm part) has been impossible with any combination of common rock‐forming minerals such as silicates and metallic irons. However, this study shows, for the first time, excellent fits of reflectance spectra of an A asteroid (Aeternitas) and an R asteroid (Dembowska), including their visible spectral curves, band depths and shapes, and overall continuum shapes. Our results provide estimates that Aeternitas consists of 2% fresh olivine, 93% space‐weathered olivine, 1% space‐weathered orthopyroxene, and 4% chromite, and that Dembowska consists of 1% fresh olivine, 55% space‐weathered olivine, and 44% space‐weathered orthopyroxene. These results suggest that space weathering effects maybe important to the interpretation of asteroid reflectance spectra, even those with deep silicate absorption bands. Modified Gaussian model deconvolutions of the laser‐irradiated olivine samples show that their identity as olivine remained. The most recent submicroscopic mineralogical analyses have revealed that the laser‐irradiated olivine samples contain nanophase iron particles similar to those in space‐weathered lunar samples.
Depositional models for moraine formation in East Antarctic coastal oases

Abstract This paper examines the origin of moraine ridges in East Antarctic coastal oases and derives depositional models appropriate for the reconstruction of Quaternary history. On the basis of morphology, structure and sedimentology, four principal types of ridge may be identified: (1) type A moraines from when the basal debris zone crops out near an ice margin; (2) type B moraines form when large recumbent folds develop in the basal debris zone; (3) type C moraines are ice-contact screes and fans which form when debris accumulates at steep or cliffed ice margins; and (4) type D moraines are thrust-block moraines that form when unconsolidated sediment is entrained by freezing, shearing and thrusting of sediment blocks at the base of the glacier. Simple calculations of the rate of debris accumulation at ice margins suggest that type A, B and C moraines take thousands of years to form and record stable ice margins. Type D moraines are structural features that may form relatively quickly when ice margins override unconsolidated sediment. Constructing models to explain the origin of the moraines is an important part of reconstructing the Quaternary history of Antarctic coastal oases, because the models provide a basis for reconstructing the position and behaviour of the ice sheet during advance and retreat
The rôle of thermohaline circulation in climate

This article discusses the role of the THC in climate, based upon the results of several numerical experiments which use a coupled ocean-atmosphere model developed at the Geophysical Fluid Dynamics Laboratory of NOAA, USA. The first part of the article explores the mechanism which is responsible for the abrupt climate change such as the Younger Dryas event using the coupled model. In response to the freshwater discharge into high north Atlantic latitudes over a period of 500 years, the THC in the Atlantic Ocean weakens, reducing surface air temperature over the northern north Atlantic Ocean, the Scandinavian Peninsula, and the circumpolar ocean and Antarctic Continent of the southern hemisphere. Upon the termination of the water discharge at the 500th year, the THC begins to intensify, regaining its original intensity in a few hundred years. In addition, the sudden onset and the termination of the discharge of freshwater induces the multidecadal fluctuation in the intensity of the THC, which generates the almost abrupt change of climate. It is noted that similar but much weaker oscillation of the THC is also evident in the control integration of the coupled model without freshwater forcing. The irregular oscillation of the THC mentioned above appears to be related to the fluctuation of the Subarctic Gyre and associated east Greenland current, yielding the evolution of the surface salinity anomaly which resembles that of “great salinity anomaly”. The second part of this article describes the response of a coupled ocean-atmosphere model to the doubling and quadrupling of atmospheric carbon dioxide over centuries time-scale. In one integration, the CO 2 concentration increases by 1%/year (compounded) until it reaches 4 × the initial value at the 140th year and remains unchanged thereafter. In another integration, the CO 2 concentration also incleases at the rate of 1%/year until it reaches 2 × the initial value at the 70th year and remains unchanged thereafter. One of the most notable features of the CO 2 -quadrupling integration is the gradual disappearance of thermohaline circulation in most of the model oceans during the first 250-year period, leaving behind wind-driven cells. For example, thermohaline circulation nearly vanishes in the north Atlantic by the 250 years of the integration and remains very weak until the 900th year. However, it begins to restore the original intensity by the 1600th year. In the CO 2 -doubling integration, the thermohaline circulation weakens by a factor of more than 2 in the North Atlantic during the first 150 years, but almost recovers its original intensity by the 500th year. The weakening of the THC moderates temporarily the greenhouse warming over the north Atlantic Ocean and its vicinity. In both numerical experiments described above, the initial weakening of the THC results from the capping of oceanic surface by relatively fresh, low-density water, which surpresses the convective cooling of water in the sinking region of the THC. DOI: 10.1034/j.1600-0889.1999. 00008.x
The relation between heat flow, sediment thickness, and age in the eastern Pacific

Heat flow measurements in the eastern Pacific now total over 800, a sufficient number to permit the analysis of their distribution within a wide range of age zones. Major results are that (1) the mid-ocean ridge crestal regions have lower heat flow than that expected from conductive cooling models of the lithospheric plate, (2) an increase in heat flow is observed some distance away from the crest in a zone which appears to delineate a transition from dominantly convective to conductive heat transfer, and (3) the heat flow in crust older than this transition zone closely approximates that predicted by conductive cooling models for oceanic lithospheric plates. The transition from low to high heat flow occurs when 150-200 m of sediment is deposited over basement, apparently preventing convective transfer of heat from the oceanic crust to seawater. Thus the general shape of the empirical heat flow versus age curve for the East Pacific Rise (EPR) agrees with that from the Galapagos Spreading Center, but the age of the transition zone occurs in 5- to 6-m.y. -old crust on the Galapagos Spreading Center, whereas it occurs in 10- to 15-m.y. -old sea floor on the EPR. Proximity to the equatorial high sedimentation regionmore » causes the deposition of a thick layer of sediment much more quickly on the Galapagos Spreading Center than on the East Pacific Rise. Quantitatively, the degree of heat transfer by convection appears to correlate inversely with the ratio of sediment thickness to topographic relief. « less
Effect of Tropical Alfalfa on Cholesterol (Egg and Blood) and Layer Chicken Meat Quality

: Tropical alfalfa is a cultivar of alfalfa with high protein content and good adaptability with the local name Kacang Ratu BW. The supplementation of duck feed with tropical alfalfa or Kacang Ratu BW may reduce the cholesterol levels in duck meat with the presence of saponin. This study aimed to determine the effects of Kacang Ratu BW supplementation on egg cholesterol and meat quality in layer chickens. A total of 60 hyline brown chickens, aged 26 weeks, were reared at three different rearing periods and sacrificed at 38 weeks. The feed treatments were P 0 (Basal ration), P 1 (Basal ration +1% Kacang Ratu BW) and P 2 (Basal ration +3% Kacang Ratu BW). The measured parameters were meat quality (carcass and chemical quality), yolk quality (water, crude protein, and fat contents), and cholesterol level (yolk and blood). The results showed that Kacang Ratu BW supplementation significantly influenced egg yolk cholesterol and meat fat. However, the water and protein contents of the meat and eggs were not affected. Our findings indicated that feed supplemented with Kacang Ratu BW reduced the egg yolk cholesterol and the fat content of the layer of
Mangrove‐forest evolution in a sediment‐rich estuarine system: opportunists or agents of geomorphic change?

The majority of the world's mangrove forests occur on mostly mineral sediments of fluvial origin. Two perspectives exist on the biogeomorphic development of these forests, i.e. that mangroves are opportunistic, with forest development primarily driven by physical processes, or alternatively that biophysical feedbacks strongly influence sedimentation and resulting geomorphology. On the Firth of Thames coast, New Zealand, we evaluate these two possible scenarios for sediment accumulation and forest development using high‐resolution sedimentary records and a detailed chronology of mangrove‐forest (Avicennia marina) development since the 1950s. Cores were collected along a shore‐normal transect of known elevation relative to mean sea level (MSL). Activities for lead‐210 (210Pb), caesium‐137 (137Cs) and beryllium‐7 (7Be), and sediment properties were analysed, with 210Pb sediment accumulation rates (SARs), compensated for deep subsidence (~8 mm yr−1) used as a proxy for elevation gain. At least four phases of forest development since the 1950s are recognized. An old‐growth forest developed by the late‐1970s with more recent seaward forest expansion thereafter. Excess 210Pb profiles from the old‐growth forest exhibit relatively low SARs near the top (7–12 mm yr−1) and bottom (10–22 mm yr−1) of cores, separated by an interval of higher SARs (33–100 mm yr−1). A general trend of increasing SAR over time characterizes the recent forest. Biogeomorphic evolution of the system is more complex than simple mudflat accretion/progradation and mangrove‐forest expansion. Surface‐elevation gain in the old‐growth forest displays an asymptotic trajectory, with a secondary depocentre developing on the seaward mudflat from the mid‐1970s. Two‐ to ten‐fold increases in 210Pb SARs are unambiguously large and occurred years to decades before seedling recruitment, demonstrating that mangroves do not measurably enhance sedimentation over annual to decadal timescales. This suggests that mangrove‐forest development is largely dependent on physical processes, with forests occupying mudflats once they reach a suitable elevation in the intertidal. Copyright © 2015 John Wiley & Sons, Ltd.
Time‐varying sensitivity analysis clarifies the effects of watershed model formulation on model behavior

Lumped rainfall‐runoff models are widely used for flow prediction, but a long‐recognized need exists for diagnostic tools to determine whether the process‐level behavior of a model aligns with the expectations inherent in its formulation. To this end, we develop a comprehensive exploration of dominant parameters in the Hymod, HBV, and Sacramento Soil Moisture Accounting (SAC‐SMA) model structures. Model controls are isolated using time‐varying Sobol′ sensitivity analysis for twelve MOPEX watersheds in the eastern United States over a 10 year period. Sensitivity indices are visualized along gradients of observed precipitation and streamflow to identify key behavioral differences between the three models and to connect these back to the models' underlying assumptions. Results indicate that the models' dominant parameters strongly depend on time‐varying hydroclimatic conditions. Parameters associated with surface processes such as evapotranspiration and runoff generally dominate under dry conditions, when high evaporative fluxes are required for accurate simulation. Parameters associated with routing processes typically dominate under high‐flow conditions, when performance depends on the timing of flow events. The results highlight significant inter‐model differences in performance controls, even in cases where the models share similar process formulations. The dominant parameters identified can be counterintuitive; even these simple models represent complex, nonlinear systems, and the links between formulation and behavior are difficult to discern a priori as complexity increases. Scrutinizing the links between model formulation and behavior becomes an important diagnostic approach, particularly in applications such as predictions under change where dominant model controls will shift under hydrologic extremes.
A comparative assessment between object and pixel-based classification approaches for land use/land cover mapping using SPOT 5 imagery

Abstract Land use/land cover (LULC) classification with high accuracy is necessary, especially in eco-environment research, urban planning, vegetation condition study and soil management. Over the last decade a number of classification algorithms have been developed for the analysis of remotely sensed data. The most notable algorithms are the object-oriented K-Nearest Neighbour (K-NN), Support Vector Machines (SVMs) and the Decision Trees (DTs) amongst many others. In this study, LULC types of Selangor area were analyzed on the basis of the classification results acquired using the pixel-based and object-based image analysis approaches. SPOT 5 satellite images with four spectral bands from 2003 and 2010 were used to carry out the image classification and ground truth data were collected from Google Earth and field trips. In pixel-based image analysis, a supervised classification was performed using the DT classifier. On the other hand, object-oriented (K-NN) image analysis was evaluated using standard nearest neighbour as classifier. Subsequently SVM object-based classification was performed. Five LULC categories were extracted and the results were compared between them. The overall classification accuracies for 2003 and 2010 showed that the object-oriented (K-NN) (90.5% and 91%) performed better results than the pixel-based DT (68.6% and 68.4%) and object-based SVM (80.6% and 78.15%). In general, the object-oriented (K-NN) performed better than both DTs and SVMs. The obtained LULC classification maps can be used to improve various applications such as change detection, urban design, environmental management and zooning.