Miracle-dz/UniFAR-FTUs huggingface dataset:
Impact of Sampling Depth on Differences in Soil Carbon Stocks in Long-Term Agroecosystem Experiments

The depth of sampling has recently been highlighted as critical to making accurate measurements of changes in SOC stocks. This paper aimed to determine the effects of land management changes (LMC) on soil organic carbon (SOC) by re-sampling long-term agoecosystem experiments (LTAEs) across Canada using identical sampling and laboratory protocols. The impact of sampling depth on the monitoring of LMC-induced differences in SOC stock in LTAEs in Canada, and the implications on statistical power and sampling design, were assessed. In most cases, four cores would be suitable for detecting a significant difference in SOC stock of 5 Mg ha -1 at 95% confidence for LMCs in western Canada. The impact of eliminating fallow on SOC stocks was typically restricted to the surface 15 cm. The impact of perennial forages on the average cumulative SOC was sufficiently large to be detectable at all sampling depths (to 60 cm). In three of the six LTAEs sampled in western Canada comparing conventional tillage to no-till, there was a significantly greater SOC storage in the 0- to 30-depth than the 0- to 15-cm depth, suggesting that sampling below 15 cm could be necessary. The same comparisons in eastern Canada suggested that sampling often must exceed the 30-cm depth to account for any changes in SOC due to moldboard plow tillage. Nonetheless, there was little evidence to suggest that increasing sampling intensity or sampling deeper would improve the ability to detect a difference in SOC stocks for this LMC.
The Role of Landscape in the Distribution of Deer-Vehicle Collisions in South Mississippi

Deer-vehicle collisions (DVCs) have a negative impact on the economy, traffic safety, and the general well-being of otherwise healthy deer. To mitigate DVCs, it is imperative to gain a better understanding of factors that play a role in their spatial distribution. Much of the existing research on DVCs in the United States has been inconclusive, pointing to a variety of causal factors that seem more specific to study site and region than indicative of broad patterns. Little DVC research has been conducted in the southern United States, making the region particularly important with regard to this issue. In this study, we evaluate landscape factors that contributed to the distribution of 347 DVCs that occurred in Forrest and Lamar Counties of south Mississippi, from 2006 to 2009. Using nearest-neighbor and discriminant analysis, we demonstrate that DVCs in south Mississippi are not random spatial phenomena. We also develop a classification model that identified seven landscape metrics, explained 100 percent of the variance, and could distinguish DVCs from control sites with an accuracy of 81.3 percent.
Simplify Support Vector Machines by Iterative Learning

Support vector machines(SVM) perform good generalization ability on various application fields in practice,especially for small sample problems.But in the SVM research on handwritten character recognition,it is substantially slower in test phase than neural networks with same generalization performance.So simplifying SVM without loss in generalization ability is important research in order to improve the classification speed of SVM.In this paper,we use iterative learning method to simplify the decision function of SVM.Computational results show that our method can simplify SVM effectively,it cam be implemented easily.
Relative Entropy Relaxations for Signomial Optimization

Signomial programs (SPs) are optimization problems specified in terms of signomials, which are weighted sums of exponentials composed with linear functionals of a decision variable. SPs are nonconvex optimization problems in general, and families of NP-hard problems can be reduced to SPs. In this paper we describe a hierarchy of convex relaxations to obtain successively tighter lower bounds of the optimal value of SPs. This sequence of lower bounds is computed by solving increasingly larger-sized relative entropy optimization problems, which are convex programs specified in terms of linear and relative entropy functions. Our approach relies crucially on the observation that the relative entropy function, by virtue of its joint convexity with respect to both arguments, provides a convex parametrization of certain sets of globally nonnegative signomials with efficiently computable nonnegativity certificates via the arithmetic-geometric-mean inequality. By appealing to representation theorems from real algeb.
Thermal structure and dust loading of the Martian atmosphere during late southern summer: Mariner 9 revisited

The temperature structure and dust loading of the Martian atmosphere are investigated using thermal emission spectra recorded by the Mariner 9 infrared interferometer spectrometer (IRIS). The analysis is restricted to a subset of the IRIS data consisting of approximately 2400 spectra in a 12-day period extending from LS =343° to LS =348°, corresponding to late southern summer on Mars. Simultaneous retrieval of the vertical distribution of both atmospheric temperature and dust optical depth is accomplished through an iterative procedure which is performed on each spectrum. The inclusion of dust opacity in the retrieval algorithm causes the retrieved temperatures to change by more than 20 K in some atmospheric layers. The largest column-integrated 9 μm dust optical depths (∼ 0.4) occur over the equatorial regions. The highest atmospheric temperatures (> 260 K) are found at low altitudes near the subsolar latitude (∼ 6°S) while the coldest temperatures (< 150 K) are found at levels near 1.0 mbar over the winter pole. A comparison of temperature maps for 1400 LT and 0200 LT indicates diurnal temperature variations as large as 80 K at low altitudes near the subsolar latitude, whereas diurnal temperature changes at pressures less than 1.0 mbar are typically about 10 K. Both dayside and night side temperatures above about 0.1 mbar (∼ 40 km) are warmer over the winter (north) polar region than over the equator or the summer (south) polar region. This thermal structure suggests the existence of a net zonally averaged meridional circulation with rising motion at low latitudes, poleward flow at altitudes above 40 km, and subsidence over the poles. Because a meridional circulation transports atmospheric constituents as well as heat, it has significant implications for the net flux of dust and water into the polar regions.
Planetary boundary layer errors in mesoscale inversions of column‐integrated CO2 measurements

Observing platforms of greenhouse gas column mole fractions using remote sensing instruments have enhanced the capability of carbon data assimilation systems at large scales and helped improve our understanding of the underlying processes involved in the exchange of carbon at the surface of the globe. In this study, we quantify the additional information carried by these measurements at finer scales and consider the impact of vertical transport errors in current modeling systems, one of the main sources of uncertainties in regional inverse flux estimates. Surface‐based column‐integrated sensors are shown to be a significant source of information to constrain local surface fluxes at fine scales. Gain and error reduction are only about 20% lower than for in situ instruments. Column measurements show less dependence on near‐field surface fluxes compared to in situ, with the error reduction being more homogeneously distributed. However, vertical transport errors still impact the flux retrievals, as with in situ measurements but to a lesser extent. Inverse fluxes from both types of measurements were affected by errors in vertical mixing and mean horizontal winds, with a larger impact on the inverse carbon balance using in situ measurements. The use of remote sensing measurements also appeared to constrain significantly the boundary concentrations, a critical limitation in current regional inversions. We finally performed a pseudo‐data experiment combining both types of instruments, creating an optimal observing network with a lower impact of planetary boundary layer transport errors on the surface fluxes and the boundary concentrations, and a more widely distributed reduction of the errors over the boundaries.
Redox‐controlled multiple‐species reactive chemical transport: 1. Model development

A redox-controlled multiple-species, multidimensional reactive chemical transport model, DYNAMIX, is developed. The model includes advection, diffusion-dispersion, transport of oxygen, oxidation-reduction and, as a consequence, acid-base reactions, aqueous complexation, precipitation-dissolution, and kinetic mineral dissolution. A partial equilibrium condition is incorporated into the model which accounts for both thermodynamic equilibrium and kinetic chemical interaction between aqueous and solid phases. The model solves for aqueous and mineral phase compositions as function of time and space. A correct mineral assemblage is automatically searched for based on the principle of minimized Gibbs free energy. The mass of chemicals is conserved in both aqueous and solid phases. A two-step dynamic mixing algorithm is used to solve the coupled transport and reaction equations. At each time step, the transport equation is first solved by the explicit difference method. The chemical equilibrium submodel is then called to calculate the distribution of chemical species under thermodynamic partial equilibrium conditions. By splitting the transport and reaction equations, the two-step method significantly reduces computational time and memory storage requirements, which allows DYNAMIX to efficiently handle two- or three-dimensional problems.
Distance-Redshift Relation in a Realistic Inhomogeneous Universe

We investigate the distance-redshift relation in a realistic inhomogeneous universe where the mass distribution is described by the mass function of Sheth and Tormen. It is found that the derived distance deviates systematically from the standard distance up to 10% depending on the choice of the lowest halo mass in which baryonic matter condensed to form luminous object such as galaxies. Remarkably the derived distance is well approximated by the Dyer-Roeder distance if we choose the clumpiness parameter α calculated by our model. We also discuss the effect of inhomogeneities in the determination of dark energy parameter in the supernovae observation, and find that this effect must be taken into account for the future high redshift supernovae observation. Subject Index: 401, 402, 466
Comparison of slow‐release nitrogen yield from organic soil amendments and chemical fertilizers and implications for regeneration of disturbed sites

Soil amendments are commonly used to regenerate nutrient levels on disturbed construction sites or mined lands prior to revegetation. Management of nitrogen (N) inputs to the degraded substrates is difficult because the low level of ambient fertility on disturbed substrates requires large total N inputs to sustain revegetative growth, but it also requires low N bioavailability in order to avoid weedy invasion and eutrophication of local watersheds. Commonly available soil amendment materials have a wide variety of N contents and release rates, making specification of appropriate N amendments difficult. We compared N release rates of a variety of organic‐based soil amendments and chemical fertilizers in long‐term aerobic incubation chambers in the lab and at a field revegetation site. The N release rate from these amendments fell into four general groups: (1) rapid N release from soluble chemical fertilizer formulations, (2) longer, controlled N release from chemical‐based, slow‐release formulations, and a two‐phase release pattern (rapid initial phase, slower second phase) from (3) organic‐based blends, as well as (4) unsupplemented municipal yard‐waste composts. The release rates from organic‐based amendments were about three times faster in the 30°C laboratory incubations than in the cool, moist winter growing season at a field site in the Central Valley of California. Relative rates of N release can be compared between amendment materials to help guide selection of N amendments, according to the plant‐growth goals of the revegetation project. Copyright © 2006 John Wiley & Sons, Ltd.
Observation of the resonant character of the $Z(4430)^-$ state

Resonant structures in $B^0\to\psi'\pi^-K^+$ decays are analyzed by performing a four-dimensional fit of the decay amplitude, using $pp$ collision data corresponding to $\rm 3 fb^{-1}$ collected with the LHCb detector. The data cannot be described with $K^+\pi^-$ resonances alone, which is confirmed with a model-independent approach. A highly significant $Z(4430)^-\to\psi'\pi^-$ component is required, thus confirming the existence of this state. The observed evolution of the $Z(4430)^-$ amplitude with the $\psi'\pi^-$ mass establishes the resonant nature of this particle. The mass and width measurements are substantially improved. The spin-parity is determined unambiguously to be $1^+$.
PRE-FAILURE INSTABILITY BEHAVIOR OF SAND IN STRAIN PATH TESTING UNDER PLANE-STRAIN CONDITIONS

Experimental data are presented in this paper to study the instability behavior of sand in strain path testing under plane-strain conditions. K0 consolidated strain path tests were conducted on Changi sand using a plane-strain apparatus. The test results show that the occurrence of pre-failure instability under plane-strain conditions is affected by the void ratio and the strain increment ratio. This is consistent with previous findings established under axisymmetric conditions. However, instability behavior of medium dense sand in strain path-controlled plane-strain tests can also be affected by shear band formation. In this case, on-failure instability takes place and failure is likely caused by shear band development. This observation is different from that in triaxial strain path-controlled tests where shear bands do not normally occur.
Phosphate availability and the ultimate control of new nitrogen input by nitrogen fixation in the tropical Pacific Ocean

Abstract. Due to the low atmospheric input of phosphate into the open ocean, it is one of the key nutrients that could ultimately control primary production and carbon export into the deep ocean. The observed trend over the last 20 years has shown a decrease in the dissolved inorganic phosphate (DIP) pool in the North Pacific gyre, which has been correlated to the increase in di-nitrogen (N2) fixation rates. Following a NW-SE transect, in the Southeast Pacific during the early austral summer (BIOSOPE cruise), we present data on DIP, dissolved organic phosphate (DOP) and particulate phosphate (PP) pools along with DIP turnover times (TDIP) and N2 fixation rates. We observed a decrease in DIP concentration from the edges to the centre of the gyre. Nevertheless the DIP concentrations remained above 100 nmol L−1 and T DIP was more than 6 months in the centre of the gyre; DIP availability remained largely above the level required for phosphate limitation to occur and the absence of Trichodesmium spp and low nitrogen fixation rates were likely to be controlled by other factors such as temperature or iron availability. This contrasts with recent observations in the North Pacific Ocean at the ALOHA station and in the western Pacific Ocean at the same latitude (DIAPALIS cruises) where lower DIP concentrations (
The North Atlantic thermohaline circulation simulated by the GISS climate model during 1970–99

Abstract Evidence based on numerical simulations is presented for a strong correlation between the North Atlantic Oscillation (NAO) and the North Atlantic overturning circulation. Using an ensemble of numerical experiments with a coupled ocean‐atmosphere model including both natural and anthropogenic forcings, it is shown that the weakening of the thermohaline circulation (THC) could be delayed in response to a sustained upward trend in the NAO, which was observed over the last three decades of the twentieth century, 1970–99. Overall warming and enhanced horizontal transports of heat from the tropics to the subpolar North Atlantic overwhelm the NAO‐induced cooling of the upper ocean layers due to enhanced fluxes of latent and sensible heat, so that the net effect of warmed surface ocean temperatures acts to increase the vertical stability of the ocean column. However, the strong westerly winds cause increased evaporation from the ocean surface, which leads to a reduced fresh water flux over the western part of the North Atlantic. Horizontal poleward transport of salinity anomalies from the tropical Atlantic is the major contributor to the increasing salinities in the sinking regions of the North Atlantic. The effect of positive salinity anomalies on surface ocean density overrides the opposing effect of enhanced warming of the ocean surface, which causes an increase in surface density in the Labrador Sea and in the ocean area south of Greenland. The increased density of the upper ocean layer leads to deeper convection in the Labrador Sea and in the western North Atlantic. With a lag of four years, the meridional overturning circulation of the North Atlantic shows strengthening as it adjusts to positive density anomalies and enhanced vertical mixing. During the positive NAO trend, the salinity‐driven density instability in the upper ocean, due to both increased northward ocean transports of salinity and decreased atmospheric freshwater fluxes, results in a strengthening overturning circulation in the North Atlantic when the surface atmospheric temperature increases by 0.3°C and the ocean surface temperature warms by 0.5° to 1°C.
Empirical Relations in Properties of Unconsolidated Quartz Sands and Silts Pertaining to Water Flow

During a laboratory investigation using radiotracers, empirical formulas were developed to replace the ambiguous or incorrect Dupuit-Forchheimer assumption used in relationships governing the flow of water through porous, unconsolidated materials ranging from clay to coarse sands or fine gravels. The Dupuit-Forchheimer assumption states that the ratio of specific flow rate to average flow velocity is equal to porosity, but it is not specified whether true porosity or void ratio or specific yield, also called effective porosity, is meant. The hydraulic conductivity shows a good correlation with the maximum 10% grain size, and the ratio of specific flow rate to average flow velocity shows good correlation with functions of specific yield and percentile sorting coefficient. From field measurements of specific flow rate and average flow velocity the specific yield can be computed.
X-ray emission from the stellar population in M 32

Using Chandra observations, we study the X-ray emission of the stellar population in the compact dwarf elliptical galaxy M 32. The proximity of M 32 allows one to resolve all bright point sources with luminosities higher than $8\times10^{33}~{\rm erg~s^{-1}}$ in the 0.5–7 keV band. The remaining (unresolved) emission closely follows the galaxy's optical light and is characterized by an emissivity per unit stellar mass of ~$4.3\times10^{27}~{\rm erg~s^{-1}}~M_\odot^{-1}$ in the 2–10 keV energy band. The spectrum of the unresolved emission above a few keV smoothly joins the X-ray spectrum of the Milky Way's ridge measured with RXTE and INTEGRAL . These results strongly suggest that weak discrete X-ray sources (accreting white dwarfs and active binary stars) provide the bulk of the “diffuse” emission of this gas-poor galaxy. Within the uncertainties, the average X-ray properties of the M 32 stars are consistent with those of the old stellar population in the Milky Way. The inferred cumulative soft X-ray (0.5–2 keV) emissivity is however smaller than is measured in the immediate Solar vicinity in our Galaxy. This difference is probably linked to the contribution of young (age $\ll 1$ Gyr) stars, which are abundant in the Solar neighborhood but practically absent in M 32. Combining Chandra , RXTE and INTEGRAL data, we obtain a broad-band (0.5–60 keV) X-ray spectrum of the old stellar population in galaxies.
Executions, Deterrence and Homicide: A Tale of Two Cities - eScholarship

We compare homicide rates in two quite similar cities with vastly different execution risks. Singapore had an execution rate close to 1 per million per year until an explosive twentyfold increase in 1994-95 and 96 to a level that we show was probably the highest in the world. Then over the next 11 years, Singapore executions dropped by about 95%. Hong Kong, by contrast, has no executions all during the last generation and abolished capital punishment in 1993. Homicide levels and trends are remarkably similar in these two cities over the 35 years after 1973, with neither the surge in Singapore executions nor the more recent steep drop producing any differential impact. By comparing two closely matched places with huge contrasts in actual execution but no differences in homicide trends, we have generated a unique test of the exuberant claims of deterrence that have been produced over the past decade in the U.S.
MODIS‐based remote sensing monitoring of grass production in China

Monitoring grassland production is of great importance for utilizing and administering grassland, developing pasturage and improving the ecological environment. Using Moderate Resolution Imaging Spectroradiometer (MODIS) data and ground truth data for the six grassland regions of China, regional models were established to estimate the grassland production in 2005. The Normalized Difference Vegetation Index (NDVI) was first computed from the MODIS data. Ground truth data were obtained from a large‐scale field investigation in 2005. The following results were obtained: (1) total hay output from the grassland in China was 294 214 thousand tons in 2005, with an average yield of 830 kg/ha. (2) There were three regions with high grass productivity in 2005: the grassland covering Hulunbuir, Xilinhaote and the western Daxing'anling; the region including eastern Qinghai, northwestern Sichuan and mid‐southern Gansu; and the northwestern Xinjiang region. (3) Grassland production for the whole of China in August 2005 remained at the same level as that in August 2004. However, the situation in the major grassland provinces was different: grass production in 2005 in both Qinghai and Gansu increased by 9% and 4%, respectively, when compared with that in 2004. Grass production in Inner Mongolia decreased by 3%, while the production in Liaoning, Xinjiang and Sichuan remained unchanged in comparison to that in 2004. (4) The models based on the six regions are the most suitable for monitoring grass production in China and can meet the need of estimating of grass productivity. The results are very important for grassland administration, pasture grazing and grassland ecosystem studies in China.