Miracle-dz/UniFAR-FTUs huggingface dataset:
Aspectos metodológicos del uso del análisis de componentes principales en campos de anomalias de altura geopotencial en el sur de sudamerica

This paper presents a discussion of methodological aspects of the use of the principal component analysis (PCA) to verify its efficacy synthesis for the daily 1000 and 500 hPa anomalies of geopotential height fields of the October to May 1979-2001 NCEP reanalyses II in southern South America. This analysis was performed in order to obtain a representative data base for future synoptic classifications. The need of orthogonal rotations and their efficacy was analyzed showing that the explained variance redistribution was not improved. A random sub-sample of 100 days was used to study the influence of the persistence effect of consecutive daily fields. This effect did not significantly modify the PCA results and did not introduce other significant PCs. The set of geopotential height data may be considerably reduced using PCA as a synthesis technique. This result was corroborated using Bartletts sphericity test and an empirical test on the modified correlation matrix. Finally, to represent a real field and thus facilitate a physical sense, it is found that the combination of two or more PCs is necessary.
Past hydrological events and global change

Gregory, K. J., Benito, G. , Dikau, R. , Golosov, V. , Johnstone, E. C. , Jones, J. A. A. , Macklin, Mark G. , Parsons, A. J., Passmore, D. G. , Poesen, J., Soja, R. , Starkel, L. , Thorndydraft, V. R. , Walling, D. E. (2006). Past hydrological events and global change. 20: 199-204.
The role of protected areas in supplying ten critical ecosystem services in drylands: a review

Well-designed and effectively managed protected areas can be a key component of strategies to address the breakdown of ecosystem services in drylands. Environmental degradation has led to food and water insecurity, dust storms and desertification. Protected areas allow maintenance and where necessary restoration of natural vegetation regimes, thus reducing erosion, reviving aquifers and maintaining sustainable livelihoods for local communities. Protected areas in drylands embrace a full range of management approaches, from strict protection to ‘protected landscapes’ where conservation is integrated with traditional lifestyles; a certain amount of grazing is often beneficial to vegetation management for instance. They vary from government-run national parks to ancient examples of community conserved areas, such as the hima of the Arabian Peninsula, which are closely linked to Islam and are currently being revived. A detailed review of options is presented, with numerous examples from dryland regions of the world, along with a typology of ecosystem services maintained. Implementation of the Convention on Biological Diversity’s Programme of Work on Protected Areas and establishment of effective protected area networks in drylands would address many of the challenges identified by the UN Convention to Combat Desertification. But this implies new attitudes to protected areas, involving greater willingness to consider community-led approaches and different and more diverse governance structures, alongside government efforts.
A Compact MPFA Method with Improved Robustness

MPFA methods were introduced to solve control- volume formulations on general grids. While these methods are general in the sense that they may be applied to any grid, their convergence properties vary. An important property for multiphase flow is the monotonicity of the numerical elliptic operator. In a recent paper, conditions for monotonicity on quadrilateral grids have been developed. These conditions indicate that MPFA formulations which lead to smaller flux stencils, are desirable for grids with high aspect ratio or severe skewness and for media with strong anisotropy or strong heterogeneity. We introduce a new MPFA method for quadrilateral grids termed the L-method. The methodology is valid for general media. For homogeneous media and uniform grids, this method has four-point flux stencils and seven-point cell stencils in two dimensions. The reduced stencil appears as a consequence of adapting the method to the closest neighboring cells. We have tested the convergence and monotonicity properties for this method, and compared it with the O-method. For moderate grids the convergence rates are the same, but for rough grids with large aspect ratios, the convergence of the O-methods is lost, while the L-method converges with a reduced convergence rate. The L-method has a somewhat larger monotonicity range than the O-methods, but the dominant difference is that when monotonicity is lost, the O-methods may give large oscillations, while the oscillations with the L-method are small or absent.
Estimating storm areal average rainfall intensity in field experiments

Estimates of areal mean precipitation intensity derived from rain gages are commonly used to assess the performance of rainfall radars and satellite rainfall retrieval algorithms. Areal mean precipitation time series collected during short-duration climate field studies are also used as inputs to water and energy balance models which simulate land-atmosphere interactions during the experiments. In two recent field experiments (1987 First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE) and the Multisensor Airborne Campaign for Hydrology 1990 (MAC-HYDRO '90)) designed to investigate the climatic signatures of land-surface forcings and to test airborne sensors, rain gages were placed over the watersheds of interest. These gages provide the sole means for estimating storm precipitation over these areas, and the gage densities present during these experiments indicate that there is a large uncertainty in estimating areal mean precipitation intensity for single storm events. Using a theoretical model of time- and area-averaged space- time rainfall and a model rainfall generator, the error structure of areal mean precipitation intensity is studied for storms statistically similar to those observed in the FIFE and MAC-HYDRO field experiments. Comparisons of the error versus gage density trade-off curves to those calculated using the storm observations show that the rainfall simulator can provide good estimates of the expected measurement error given only the expected intensity, coefficient of variation, and rain cell diameter or correlation length scale, and that these errors can quickly become very large (in excess of 20%) for certain storms measured with a network whose size is below a “critical” gage density. Because the mean storm rainfall error is particularly sensitive to the correlation length, it is important that future field experiments include radar and/or dense rain gage networks capable of accurately characterizing the rainstorm spatial and temporal correlation structure.
Privacy-preserving and Privacy-attacking Approaches for Speech and Audio - A Survey

In contemporary society, voice-controlled devices, such as smartphones and home assistants, have become pervasive due to their advanced capabilities and functionality. The always-on nature of their microphones offers users the convenience of readily accessing these devices. However, recent research and events have revealed that such voice-controlled devices are prone to various forms of malicious attacks, hence making it a growing concern for both users and researchers to safeguard against such attacks. Despite the numerous studies that have investigated adversarial attacks and privacy preservation for images, a conclusive study of this nature has not been conducted for the audio domain. Therefore, this paper aims to examine existing approaches for privacy-preserving and privacy-attacking strategies for audio and speech. To achieve this goal, we classify the attack and defense scenarios into several categories and provide detailed analysis of each approach. We also interpret the dissimilarities between the various approaches, highlight their contributions, and examine their limitations. Our investigation reveals that voice-controlled devices based on neural networks are inherently susceptible to specific types of attacks. Although it is possible to enhance the robustness of such models to certain forms of attack, more sophisticated approaches are required to comprehensively safeguard user privacy.
Room temperature phosphorescence from moisture-resistant and oxygen-barred carbon dot aggregates

Phosphorescence is difficult to be observed from carbon dot powder due to the deliquescence and self-quenching in the aggregation state. In this study, aggregation-induced room temperature phosphorescence (RTP) is first reported in self-quenching-resistant nitrogen-doped carbon dot powder, which is suggested to take advantage of the moisture-resistance, rigidization and oxygen-barrier induced by PVA-chains. Furthermore, the optical mechanism of RTP as well as fluorescence is investigated through the abnormal excitation-responsive phenomena, and the potential application in temperature sensing is also preliminarily evaluated. This study may benefit in developing phosphorescence from undesirable aggregation through structure design and exploiting emerging applications for carbon dots.
Extraction of spatial features in hyperspectral images based on the analysis of differential attribute profiles

The new generation of hyperspectral sensors can provide images with a high spectral and spatial resolution. Recent improvements in mathematical morphology have developed new techniques such as the Attribute Profiles (APs) and the Extended Attribute Profiles (EAPs) that can effectively model the spatial information in remote sensing images. The main drawbacks of these techniques is the selection of the optimal range of values related to the family of criteria adopted to each filter step, and the high dimensionality of the profiles, which results in a very large number of features and therefore provoking the Hughes phenomenon. In this work, we focus on addressing the dimensionality issue, which leads to an highly intrinsic information redundancy, proposing a novel strategy for extracting spatial information from hyperspectral images based on the analysis of the Differential Attribute Profiles (DAPs). A DAP is generated by computing the derivative of the AP; it shows at each level the residual between two adjacent levels of the AP. By analyzing the multilevel behavior of the DAP, it is possible to extract geometrical features corresponding to the structures within the scene at different scales. Our proposed approach consists of two steps: 1) a homogeneity measurement is used to identify the level L in which a given pixel belongs to a region with a physical meaning; 2) the geometrical information of the extracted regions is fused into a single map considering their level L previously identified. The process is repeated for different attributes building a reduced EAP, whose dimensionality is much lower with respect to the original EAP ones. Experiments carried out on the hyperspectral data set of Pavia University area show the effectiveness of the proposed method in extracting spatial features related to the physical structures presented in the scene, achieving higher classification accuracy with respect to the ones reported in the state-of-the-art literature
Effect of mixing patterns and light dose on growth of Anabaena circinalis in a turbid, lowland river

Anabaena circinalis is common in the lower Murray River, Australia, and may compromise water quality due to the release of toxins. The water is turbid and thermal structure may significantly affect light availability. An in situ experiment was designed to represent complete mixing, diurnal stratification and persistent stratification and test the effect on growth of A. circinalis. To represent the mixing treatments, cells were incubated in diffusion chambers that were adjusted to different positions in the water‐column throughout the day. Populations exposed to persistent stratification over six days grew significantly faster than the other treatments at a rate of 0.65 day−1. However, growth of the diurnally stratified populations was slower than (0.28 day−1), or similar to (0.40 day−1) the mixed population (0.40 day−1). Therefore, the growth of the subpopulations exposed to the euphotic zone was insufficient to counteract the slow growth of the majority that were confined to darkness during the stratified period. A relationship between growth rate (G) and average daily light dose (I) was constructed and growth rate at optimal light dose (Gmax), slope of linear section of G–I curve (α), and light dose where lines of Gmax and light‐limited portion of G–I curve intersect (Ik) were solved as 0.66 day−1, 0.12 day−1 (mol−1 m−2 day−1)−1 and 5.4 mol m−2 day−1, respectively. Using these parameters, a model was developed to predict possible differences in growth between diurnal and mixed populations under varying conditions of vertical light attenuation, mixed depth and incubation time. Copyright © 2003 John Wiley & Sons, Ltd.
IDB WORKING PAPER SERIES No . 109 New Century , Old Disparities Gender and Ethnic Wage Gaps in Latin America

This paper surveys gender and ethnic wage gaps in 18 Latin American countries, decomposing differences using matching comparisons as a non-parametric alternative to the Blinder-Oaxaca (BO) decomposition. It is found that men earn 9-27 percent more than women, with high cross-country heterogeneity. The unexplained pay gap is higher among older, informal and self-employed workers and those in small firms. Ethnic wage differences are greater than gender differences, and educational attainment differentials play an important role in explaining the gap. Higher ethnic wage gaps are found among males, singleincome generators of households and full-time workers, and in rural areas. An important share of the ethnic wage gap is due to the scarcity of minorities in highpaid positions.
Observations of Martian ice clouds by the Mars Global Surveyor Thermal Emission Spectrometer: The first Martian year

Successful operation of the Mars Global Surveyor spacecraft, beginning in September 1997 (Ls = 184°), has permitted extensive observations over more than a Martian year. Initially, thin (normal optical depth <0.06 at 825 cm−1) ice clouds and hazes were widespread, showing a distinct latitudinal gradient. With the onset of a regional dust storm at Ls = 224°, ice clouds vanished in the southern hemisphere, to reappear gradually after the decay of the storm. The zonally averaged cloud opacities show little difference between the beginning and end of the first Martian year. A broad low-latitude cloud belt with considerable longitudinal structure was present in early northern summer. Apparently characteristic of the northern summer season, it vanished between Ls = 140° and 150°. The latitudinal extent of this feature is apparently controlled by the ascending branch of the Hadley circulation. The most opaque clouds (optical depth ∼0.6) were found above the summits of major volcanic features; these showed spatial structure possibly associated with wave activity. Variety among low-lying late morning clouds suggests localized differences in circulation and microclimates. Limb observations showed extensive optically thin (optical depth <0.04) stratiform clouds at altitudes up to 55 km. Considerable latitude and altitude variations were evident in ice clouds in early northern spring (Ls = 25°); near 30 km, thin clouds extended from just north of the equator to ∼45°N, nearly to the north polar vortex. A water ice haze was present in the north polar night (Ls = 30°) at altitudes up to 40 km. Because little dust was present this probably provided heterogeneous nucleation sites for the formation of CO2 clouds and snowfall at altitudes below ∼20 km, where atmospheric temperatures dropped to the CO2 condensation point. The relatively invariant spectral shape of the water ice cloud feature over space and time indicates that ice particle radii are generally between 1 and 4 μm.
Tim ing of First Irrigation and Split Application of Nitrogen for Improved Grain Yield of Wheat in Old Himalayan Piedmont Plain of Bangladesh

ABSTRACT Soil water and nitrogen (N) are the two most important factors in wheat for obtaining higher grain yield. In this context, a field trial was conducted at the research farm (25⁰38´ N, 88⁰41´ E and 38.20 m above sea level) of the Wheat Research Centre (WRC), Bangladesh to identify the timing of first irrigation (FI timing ) and its combination with a split application of N (N SA ) for improved yield of wheat. The treatments applied were two levels of N (75 and 100 kg ha −1 ) and different amounts of N in splits with different application times of FI to verify the FI timing in light soil and to minimize N use by rescheduling the FI. Existing wheat variety ‘Prodip’ was used as the experimental material. The interaction between FI timing and N SA on yield and yield-related components of wheat, except for 1000-grain weight, did not vary significantly. However, higher grain yield (3.39 t ha −1 ) was obtained when the crop was irrigated at 15 days after sowing (DAS) than when irrigated latter (20, 25 and 30 Original Research Article
Geomorphological palaeoenvironments of the Sneeuberg Range, Great Karoo, South Africa

Sedimentary sequences within headwater valleys on the landward side of the Great Escarpment of South Africa are elucidated and their significance as indicators of environmental change is assessed. This study focuses on the Sneeuberg Range, the most prominent mountain range in the semi‐arid central Great Karoo. Valley fills of a hitherto unrecognised complexity and of a greater age than any previously recorded in the central Great Karoo are reported. Three phases of deposition spanning the Late Pleistocene up to the present are documented from sites where gully erosion has incised the valley fills. The earliest depositional phase is represented by deeply weathered, calcretised gravel deposits, which probably were emplaced by debris flow and fluvial processes in the form of a fan. These deposits subsequently were buried by finer grained, largely unconsolidated sediment, with much of this emplacement occurring during the Holocene. There is evidence for phases of landscape stability and instability within this facies. Finally, sheetwash has removed fine‐grained sediments from valley flanks and has deposited it either on valley bottoms, or in presently active gullies. This process appears to be ongoing, and is the subject of current investigation. The sedimentary deposits are interpreted as representing a wide range of palaeoenvironmental conditions that have prevailed within the central Great Karoo since the penultimate glaciation. Copyright © 2003 John Wiley & Sons, Ltd.
Generating Synthetic Daily Precipitation Realizations for Seasonal Precipitation Forecasts

AbstractSynthetic weather generation models that depend on statistics of past weather observations are often limited in their applications to issues that depend on historical weather characteristics. Enhancing these models to take advantage of increasingly available and skillful seasonal climate outlook products would broaden applications to include proactive soil and water resources management, better prediction of achieving production targets, and weather-related risk assessment. In this paper, an analytical method was developed that enables generation of daily precipitation time series for seasonal forecasts up to 12 months ahead. The method uses historical weather observations to establish reference precipitation statistics (monthly precipitation amount, number of rainy days per month, and wet–wet and dry–wet day transition probabilities) and subsequently adjusts these statistics to reflect the forecast departures from long-term average monthly precipitation. This reference and forecast departure appr.
The fractal nature of river networks

Ever since Mandelbrot (1975, 1983) coined the term, there has been speculation that river networks are fractals. Here we report analyses done on river networks to determine their fractal structure. We find that the network as a whole, although composed of nearly linear members, is practically space filling with fractal dimension near 2. The empirical results are backed by a theoretical analysis based on long-standing hydrologic concepts describing the geometric similarity of river networks. These results advance our understanding of the geometry and composition of river networks.
Analysis of GWTC-3 with fully precessing numerical relativity surrogate models

The third Gravitational-Wave Transient Catalog (GWTC-3) contains 90 binary coalescence candidates detected by the LIGO-Virgo-KAGRA Collaboration (LVK). We provide a re-analysis of binary black hole (BBH) events using a recently developed numerical relativity (NR) waveform surrogate model, NRSur7dq4, that includes all $\ell \leq 4$ spin-weighted spherical harmonic modes as well as the complete physical effects of precession. Properties of the remnant black holes' (BH's) mass, spin vector, and kick vector are found using an associated remnant surrogate model NRSur7dq4Remnant. Both NRSur7dq4 and NRSur7dq4Remnant models have errors comparable to numerical relativity simulations and allow for high-accuracy parameter estimates. We restrict our analysis to 47 BBH events that fall within the regime of validity of NRSur7dq4 (mass ratios greater than 1/6 and total masses greater than $60 M_{\odot}$). While for most of these events our results match the LVK analyses that were obtained using the semi-analytical models such as IMRPhenomXPHM and SEOBNRv4PHM, we find that for more than 20\% of events the NRSur7dq4 model recovers noticeably different measurements of black hole properties like the masses and spins, as well as extrinsic properties like the binary inclination and distance. For instance, GW150914_095045 exhibits noticeable differences in spin precession and spin magnitude measurements. Other notable findings include one event (GW191109_010717) that constrains the effective spin $\chi_{eff}$ to be negative at a 99.3\% credible level and two events (GW191109_010717 and GW200129_065458) with well-constrained kick velocities. Furthermore, compared to the models used in the LVK analyses, NRSur7dq4 recovers a larger signal-to-noise ratio and/or Bayes factors for several events.
Identification of a new dust‐stratocumulus indirect effect over the tropical North Atlantic

Over the tropical North Atlantic, during boreal summer, both stratocumulus clouds and mineral aerosols are ubiquitous. We find that low cloud fraction increases in response to high mineral aerosols loadings by 3% to 10% over much of the tropical North Atlantic, in International Satellite Cloud Climatology Project (ISSCP) and Pathfinder Atmosphere Extended (PATMOSx) observations. Using the single‐column mode of the Community Earth System Model (CESM), we estimate that this indirect effect nets a surface cooling of approximately −3 Wm−2 to −12 Wm−2 per unit of dust optical depth (DAOD) increase in mineral aerosols, similar to observed radiative forcings of −4 Wm−2 to −6 Wm−2 per unit of DAOD in ISSCP and PATMOSx. Increases in stratocumulus clouds are linked to increases in atmospheric stability, reductions in boundary layer height, and moistening of the lower atmosphere in response to increased dust load. Mineral dust is shown to behave similarly to other absorbing aerosols in indirectly forcing a response in stratocumulus clouds.