Miracle-dz/UniFAR-FTUs huggingface dataset:
Seasonal Changes and Treatment Effects on Soil Inorganic Nutrients Following a Decade of Fertilizer Addition in a Lowland Tropical Forest

We conducted monthly measurements of extractable soil nutrients, including N, P, base cations, and micronutrients, as well as the potential toxin Al, in a long-term fertilization experiment in lowland tropical rain forest in the Republic of Panama. Our prediction was that the response of individual nutrients to seasonal climate and fertilizer addition would vary depending on the nature of their biogeochemical cycles. We detected significant seasonal variation in soil pH and all nutrients measured, although only extractable K concentrations were greater in the early wet season, while extractable phosphate varied little in plots that did not receive P addition. A decade of N addition increased soil nitrate, had no effect on extractable ammonium, and decreased soil pH (∼0.8 units in plots receiving only N). The decline in pH caused a corresponding decline in extractable base cations (Ca and K) and increased extractable Al, highlighting an important but poorly understood consequence of long-term atmospheric N deposition onto tropical forests. A decade of P addition increased extractable phosphate by 50-fold, indicating that chronic fertilizer addition has overcome the high phosphate sorption capacity of the soil. Potassium addition without N increased extractable soil K by 91%, but only by 25% when K was added in combination with N, suggesting that the previously reported N × K interactive effect on trunk growth rates could be a true response to N addition. Extractable Cu and Zn were increased twofold by micronutrient fertilizer addition, were reduced in the dry season, but were not affected by N addition (i.e., soil acidification). We conclude that the response of extractable nutrients to seasonal climate and fertilizer addition varies among nutrients, and suggest that greater attention be paid to the biological implications of acidification in response to long-term atmospheric N deposition onto strongly-weathered tropical forest soils.
Paleomagnetic investigation of rhyolite lava: Is rhyolite with clearly marked flow structure a high-fidelity geomagnetic field recorder?

Rhyolite is a common volcanic rock; however, few studies have focused on the remanent magnetization of rhyolite lava, and few paleomagnetic studies have successfully investigated rhyolite lavas. We suspect that problems associated with paleomagnetic studies of rhyolite may be due to the nearly ubiquitous flow structure in rhyolite lava. In this study, we examined a thick rhyolite lava flow with clearly marked flow structure to assess its ability to record a consistent paleomagnetic direction, using material penetrated by two drill cores. Progressive thermal demagnetization isolated two magnetization components. A high-temperature component from each of the two cores yields inclinations that differ from each other. The low-temperature component had those that agreed with each other, and were also consistent with the direction expected from a geocentric axial dipole field. The modification of direction of the high-temperature component may be explained by post-magnetization acquisition tilting. The development of flow structure also leads to distortion of directions of the component, which is observed at stratigraphic positions where the volume fraction of light-colored parts of the flow structure >30%. In the case of silicic lava, the low-temperature component may retain directions parallel to the ambient field direction at the time of lava emplacement.
From Crops to Concrete: Urbanization, Deagriculturalization, and Construction Material Mining in Central Mexico

In tropical countries, urbanization and rural deagriculturalization are intimately linked processes. Growth of the construction industry, which draws labor and materials from rural and periurban areas, is a key component of rural–urban interactions. Using a case study from the Perote Valley, Mexico, this article analyzes how urban-driven concrete aggregate mining affects rural agricultural lands and livelihoods. Land-cover changes associated with aggregate surface mining were examined by comparing aerial photographs, satellite images, and Global Positioning System field maps of the valley. In addition, sixty-six formal household interviews were conducted in three agrarian communities. Results indicate that between 1995 and 2006, mine surface area quadrupled, from 181 to 706 hectares, and the spatial distribution of surface mines followed a predictable pattern of extraction, from most to least accessible. Numerous factors persuaded farmers to convert fields to mines, including increased prices for aggregates, consumerist desires for new homes, and declining returns to agriculture. Moreover, farmers believed they could or would recultivate mined land following extraction. Yet, in 2006, among the three agrarian communities, 202 (45 percent) of the 482 hectares of agricultural land extracted were not recultivated. Although deep mines were more likely to be abandoned, findings suggest that land revalorization occurred among farmers, with the scarcity value of nonrenewable aggregates gradually surpassing the land's agricultural value. In the long term, diminished agricultural potential resulting from widespread mine abandonment might drive farmers to migrate to cities for employment, creating a positive feedback between urban demand for construction aggregates and mining of agricultural fields.
Detecting hydro-climatic change using spatiotemporal analysis of rainfall time series in the Cobres River basin, Portugal

The knowledge of climatic behavior, especially u in semi-arid regions, is required to optimize the management of water resources. In this study, the climate variability is directly related to water resources that are of a high socio-economic and environmental significance. To optimize the hydraulic constructions, one needs to know the climatic behaviour of the region concerned, the role of which is very important to water resources management in the short, medium and long term. A comprehensive understanding of river flow and its distribution in time and space is essential for water resources management in the arid and or semi-arid regions. In recent years, various studies have been done detect possible climate trends and changes across the world, analyto sing changes in temperature and precipitation only (Yang
Single-Trial EEG Classification Using Spatio-Temporal Weighting and Correlation Analysis for RSVP-Based Collaborative Brain Computer Interface

Objective: Since single brain computer interface (BCI) is limited in performance, it is necessary to develop collaborative BCI (cBCI) systems which integrate multi-user electroencephalogram (EEG) information to improve system performance. However, there are still some challenges in cBCI systems, including effective discriminant feature extraction of multi-user EEG data, fusion algorithms, time reduction of system calibration, etc. Methods: This study proposed an event-related potential (ERP) feature extraction and classification algorithm of spatio-temporal weighting and correlation analysis (STC) to improve the performance of cBCI systems. The proposed STC algorithm consisted of three modules. First, source extraction and interval modeling were used to overcome the problem of inter-trial variability. Second, spatio-temporal weighting and temporal projection were utilized to extract effective discriminant features for multi-user information fusion and cross-session transfer. Third, correlation analysis was conducted to match target/non-target templates for classification of multi-user and cross-session datasets. Results: The collaborative cross-session datasets of rapid serial visual presentation (RSVP) from 14 subjects were used to evaluate the performance of the EEG classification algorithm. For single-user/collaborative EEG classification of within-session and cross-session datasets, STC had significantly higher performance than the existing state-of-the-art machine learning algorithms. Conclusion: It was demonstrated that STC was effective to improve the classification performance of multi-user collaboration and cross-session transfer for RSVP-based BCI systems, and was helpful to reduce the system calibration time.
Water Governance For Sustainable Irrigation: The Role Of Civil Society

How to share scarce water resources is one of the greatest challenges of the 21st century and presents one of the greatest risks to global societies. Governments have found it problematic to resolve these complex issues using traditional top-down approaches. Many jurisdictions have therefore made a transition from government to governance in water management as this approach integrates all sectors of civil society in the process of finding solutions with minimum socioeconomic and environmental impacts, which are widely accepted within the affected communities. This process has proven difficult and conflict ridden in most places. Australia is one of the jurisdictions in which this process has been most aggressively promoted and therefore provides a good opportunity to learn lessons for other jurisdictions.
K—Ar age, composition, and origin of Mesozoic mafic rocks related to Ferrar Group, Pensacola Mountains, Antarctica

Abstract A variety of mafic igneous bodies, including the unusually large, differentiated, layered gabbroic Dufek intrusion, and basalt and dolerite dikes and sills, intrude a Permian and older sequence in the Pensacola Mountains, near Weddell Sea, Antarctica. K-Ar age determinations show that the sills (179 ± 5 m.y.), the Dufek intrusion (172 ± 4 m.y.), and probably the dikes (minimum age 169 ± 4 m.y.) were emplaced over a narrow time interval in the Early to Middle Jurassic and are about coeval with the Ferrar Group of the Transantarctic Mountains and tholeiite elsewhere near Weddell Sea. Minerals of the sills and dikes seem to contain variable, generally minor amounts of extraneous 40Ar. Pyroxene of the Dufek intrusion lost much 40Ar, probably resulting from subsolidus phase-change activity. Inferred dike and sill magmas in Pensacola Mountains were Si02-rich tholeiites chemically like the Ross Sea area Ferrar hypersthene tholeiite, and have comparable anomalously high initial 87Sr/86Sr ratios (0.7104-0.
IDEAL PERFORMANCE CRITERIA FOR DECONVOLUTION OPERATORS

A technique to evaluate an ideal performance of a deconvolution operator has been obtained by dividing the input trace into a number of sections. The error energy is seen to decrease with an increase in the number of sections. Numerical examples show that the error energy becomes zero following a relation between the number of sections, the length of input and the length of the filter.
Angle-dependent reflectivity by means of prestack migration

Most present day seismic migration schemes determine only the zero‐offset reflection coefficient for each grid point (depth point) in the subsurface. In matrix notation, the zero‐offset reflection coefficient is found on the diagonal of a reflectivity matrix operator that transforms the illuminating source‐wave field into a reflected‐wave field. However, angle dependent reflectivity information is contained in the full reflectivity matrix. Our objective is to obtain angle‐dependent reflection coefficients from seismic data by means of prestack migration (multisource, multioffset). After downward extrapolation of source and reflected wave fields to one depth level, the rows of the reflectivity matrix (representing angle‐dependent reflectivity information for each grid point at that depth level) are recovered by deconvolving the reflected wave fields with the related source wave fields. This process is carried out in the space‐frequency domain. In order to preserve the angle‐dependent reflectivity in the im.
Constraints on the size of the Vredefort impact crater from numerical modeling

Abstract— The Vredefort structure in South Africa was created by a meteorite impact about two billion years ago. Since that time, the crater has been deeply eroded; so to estimate its original size, researchers have had to rely heavily upon comparison to other terrestrial impact structures. Recent estimates of the original crater diameter range from 160 km to as much as 400 km. In this study, we combined the capabilities of both hydrocode and finite‐element modeling, using the former to predict where the pressure of an impact‐generated shock wave would have been high enough to form planar deformation features (PDFs) and shatter cones and the latter to follow the subsequent displacement of these shock isobars during the collapse of the crater. We established constraints on the sizes of the projectile and the transient crater (and, thus, on the size of the final crater) by comparing the observed locations of PDFs around Vredefort to the results of our simulations of impacts by projectiles of various sizes. These simulations indicate that a rocky projectile with a diameter of ∼10 km, impacting vertically at a velocity of 20 km/s generates shock pressures that are consistent with the distribution of PDFs around Vredefort. These projectile parameters correspond to a transient crater ∼80 km in diameter or a final crater ∼120–160 km in diameter. Allowing for uncertainties in our modeling procedures, we consider final craters 120 to 200 km in diameter to be consistent with the observed locations of PDFs at Vredefort. The shock pressure contour corresponding to the formation of shatter cones is almost horizontal near the surface, making the locations of these features less useful constraints on the crater size. However, they may provide a constraint on the amount of erosion that has occurred since the impact.
A process-oriented model of N2O and NO emissions from forest soils: 1. Model development

To predict emissions of nitrous oxide (N 2 O) and nitric oxide (NO) from forest soils, we have developed a process-oriented model by integrating several new features with three existing models, PnET, Denitrification-Decomposition (DNDC), and a nitrification model. In the new model, two components were established to predict (1) the effects of ecological drivers (e.g., climate, soil, vegetation, and anthropogenic activity) on soil environmental factors (e.g., temperature, moisture, pH, redox potential, and substrates concentrations), and (2) effects of the soil environmental factors on the biochemical or geochemical reactions which govern NO and N 2 O production and consumption. The first component consists of three submodels for predicting soil climate, forest growth, and turnover of soil organic matter. The second component contains two submodels for nitrification and denitrification. A kinetic scheme, a so-called anaerobic balloon,' was developed to calculate the anaerobic status of the soil and divide the soil into aerobic and anaerobic fractions. Nitrification is only allowed to occur in the aerobic fraction, while denitrification occurs only in the anaerobic fraction. The size of the anaerobic balloon is defined by the simulated oxygen partial pressure which is calculated based on oxygen diffusion and consumption rates in the soil. As the balloon swells or shrinks, the model dynamically allocates substrates (e.g., dissolved organic carbon, ammonium, nitrate, etc.) into the aerobic and anaerobic fractions. With this approach, the model is able to predict both nitrification and denitrification in the same soil at the same time. This feature is important for soils where aerobic and anaerobic microsites often exist simultaneously. With the kinetic framework as well as its interacting functions, the PnET-N-DNDC model links ecological drivers to trace gas emissions. Tests for validating the new model are published in a companion paper [Stange et al., this issue].
Ocean gravity waves: A nonlinear analysis of observations

Ocean gravity waves measured at the Harvest Platform off the coast of California were analyzed using tools derived from methods of nonlinear dynamics. We compare these with laboratory data of random surface wave fields. The Harvest data show clear signs of low-dimensional dynamics in action and have an embedding dimension of six or seven. The largest Lyapunov exponent, a measure of future uncertainty, shows that the data are from a chaotic system and that predictions are limited to a horizon of about two major periods of the predominate wavelength. These results underscore the utility of nonlinear time domain methods for signal analysis and for extracting dynamical information not visible with linear methods.
Mechanical models for interseismic deformation in subduction zones

Traditionally, interseismic deformation in subduction zones has been modeled using simple elastic dislocation models (EDMs). Such models have been extensively used over the past couple of decades as geodetic networks were being established around the world. However, with the availability of 3D (vector) velocity data with dense spatio-temporal coverage during the past decade, it becomes possible to explore more complex models of deformation. Such models may allow us to infer higher-order properties of the megathrust interface or the subducting plate from the observed deformation field. For instance, we show that it may be possible to infer the elastic plate thickness of the subducting plate (over the seismic cycle timescale) under certain conditions, especially if ocean-bottom geodetic measurements become routinely available in the near future. The plate thickness can affect surface deformation on the overriding plate if only a small fraction of the flexural stresses at the trench are continuously released over the seismic cycle time-scale. Another problem we address here is how the rheology of the megathrust interface affects the evolution of slip over the seismic cycle, and therefore, the seismic hazard inferred from geodetic data. We model such slip evolution on a realistic 3D fault surface having a frictional rheology. Assuming that seismic rupture zones (or “asperities”) persist across several seismic cycles, we test the hypothesis that mechanical coupling on such asperities alone is sufficient to explain currently available geodetic observations in northern Japan. We find that it is not necessary to lock large portions of the megathrust between ruptures – unlike recent EDM predictions for northern Japan – resulting in potentially large future earthquakes. Instead, post-seismic slip around asperities immediately following seismic rupture can result in large “stress-shadow” regions, which experience negligible slip late in the cycle. Such stress-shadow regions can mimic the long-wavelength “locked” zones inferred from EDMs for the interseismic period, and account for most of the present day GPS velocities in northern Japan. The approach developed here can be extended to more complex models of deformation that include heterogeneities in crustal properties, multiple fault surfaces, and perhaps, even multiple rheologies over a single fault.
Theory and validation of the multiple window sea surface temperature technique

The development of the “split window” approach for correcting satellite measurement of radiance for atmospheric attenuation is reviewed. Then the theoretical results are compared to results from actual measurements which consist of satellite measurements in the three infrared windows of the AVHRR. Ground truth for the comparisons comes from buoys. The satellite measurements were screened for clouds, and the remaining ones were used in the analysis. Using this data set, several statistical analyses were performed. These showed that, when the two channels that are truly a split window are used, the result of the statistical model agrees with the one derived from theoretical considerations. When the 3.8-μm channel is combined with one in the 10–12 μm region, the result of the statistical model does not take the split window form. Results show that the method is capable of producing sea surface temperatures with a standard deviation of 1 K or less.
Advances in Clinical Chemistry

Advances in Clinical Chemistry, Volume 73, the latest installment in this internationally acclaimed series, contains chapters authored by world-renowned clinical laboratory scientists, physicians, and research scientists. The serial discusses the latest and most up-to-date technologies related to the field of clinical chemistry and is the benchmark for novel analytical approaches in the clinical laboratory. * Contains the expertise of international contributors * Provides the latest cutting-edge technologies in the field * Authored by world-renowned clinical laboratory scientists, physicians, and research scientists
Anisotropy of normally consolidated San Francisco Bay Mud

Consolidated-undrained tests were performed on intact specimens of San Francisco Bay mud to study the anisotropic behavior of a normally consolidated clay. Large cylindrical block samples were obtained from an excavation in reclaimed tidelands south of the San Francisco International Airport. Evidence of soil fabric and its relation to the stratigraphy of the area were studied in preparation for the investigation of anisotropy. Cubical specimens were trimmed from the block samples and tested in triaxial compression with vertical and horizontal material axes. Consolidation characteristics, as well as stress-strain, pore pressure, and strength relations, were obtained along with lateral strains in two perpendicular directions. The experimental results were carefully evaluated and showed that the clay behaved as an orthotropic material, but for practical purposes could be characterized as being cross-anisotropic. The cross-anisotropic, elastic parameters were determined and related to the initial inclinations of the effective stress paths for vertical and horizontal specimens.
Toward an improved understanding of multiphase flow in porous media

Physical description of multiphase flow in porous media ideally should be based on conservation principles. In practice, however, Darcy's law is employed as the foundation of multiphase flow studies. Darcy's law is an empirical surrogate for momentum conservation based on data obtained from experimental study of one‐dimensional single‐phase flow. In its original form [Darcy, 1856], Darcy's law contained a single, constant coefficient that depended on the properties of the medium. Since 1856, Darcy's relation has been heuristically and progressively altered by allowing this coefficient to be a spatially dependent, nonlinear function of fluid and solid phase properties, particularly of the quantities of these phases within the flow system. The shortcoming of this approach is that the governing flow equation is obtained by enhancing a simple empirical coefficient with complex functional dependencies rather than by simplifying general conservation principles. As a result, some of the important physical phenomena are not properly accounted for. Also, some assumptions intrinsic to the equations are overlooked, making accurate simulation more of an art than an entirely scientific exercise. A more general and more theoretically appealing approach to the derivation of conservation principles for multiphase flow has been evolving over the last 30 years. This approach employs a mathematical procedure for deriving conservation principles at the length scale of interest, followed by imposition of thermodynamic constraints to restrict the generality of these expressions. The product of this approach is a set of balance equations that provides a framework in which the assumptions inherent in a hypothesized model of multiphase flow are clearly stated. Requirements for more comprehensive and physically complete models can then be specified.