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Immunopeptidomics aims to identify major histocompatibility complex (MHC)-presented peptides on almost all cells that can be used in anti-cancer vaccine development. However, existing immunopeptidomics data analysis pipelines suffer from the nontryptic nature of immunopeptides, complicating their identification. Previously, peak intensity predictions by MS2PIP and retention time predictions by DeepLC have been shown to improve tryptic peptide identifications when rescoring peptide-spectrum matches with Percolator. However, as MS2PIP was tailored toward tryptic peptides, we have here retrained MS2PIP to include nontryptic peptides. Interestingly, the new models not only greatly improve predictions for immunopeptides but also yield further improvements for tryptic peptides. We show that the integration of new MS2PIP models, DeepLC, and Percolator in one software package, MS2Rescore, increases spectrum identification rate and unique identified peptides with 46% and 36% compared to standard Percolator rescoring at 1% FDR. Moreover, MS2Rescore also outperforms the current state-of-the-art in immunopeptide-specific identification approaches. Altogether, MS2Rescore thus allows substantially improved identification of novel epitopes from existing immunopeptidomics workflows.

No-tillage (NT) systems have been increasing during the last several decades. Development of a near-surface layer of laminar structure under NT has also been reported. The objectives of this work were to determine whether preferential connectivity of different pore size classes in two differently textured soils under NT exists and to propose a new index of pore connectivity based on water flux (Cw). The study was carried out at two sites in the Pampas Region of Argentina under long-term NT. Site 1 had a loamy A-horizon, and Site 2 had a sandy loam A-horizon. Undisturbed samples were extracted in vertical and horizontal directions within the first 8 cm of the soil. Saturated hydraulic conductivity (Ks), near-saturated hydraulic conductivity (h: −50, −100, −200, −300, and −500 cm), pore size distribution from water retention curve, and total porosity were determined. The index of pore connectivity based on water flux, Cw, was developed as a ratio between Kand pore volume for each pore size class. Site 1 showed laminar structure in the A-horizon, whereas Site 2 showed a blocky structure. We found a preferential connectivity in horizontal direction of macropores in Site 1. The index of pore connectivity was useful to assess the presence of preferential orientation of different pore size classes. In future studies, the connectivity of the different pore size classes should not be neglected.

This article conjoins a foundation in moral philosophy with an empirical study on the un/acceptability of moral practices in ‘Second Life’ (SL). SL-residents were asked to rank morally charged SL-scenarios in a classification from ‘(most) unacceptable’ to ‘(most) acceptable’ and, while doing so, to reason out loud about their ranking. The analysis presented here focuses on their converging and diverging arguments. Regarding converging arguments, there was consensus on the unacceptability of six scenarios. Research participants believed these scenarios transcend the merely virtual and they subsequently grounded their argumentation in actual principles. They further agreed upon seven scenarios as acceptable; these scenarios were considered as typical features of SL and subsequently were not morally problematized. Regarding other scenarios, no consensus was reached. The author discusses these findings in terms of their ethical implications and in light of current approaches in the field of ‘computer ethics’.

Rainfall simulation on micro-plot scale is a method used worldwide to assess the generation of overland flow, soil erosion, and interrelated processes such as soil sealing, crusting, splash and redistribution of solids and solutes. The so produced data are of great significance not only for the analysis of the simulated processes, but also as a source of input-data for soil erosion modelling. The reliability of the produced data therefore is of paramount importance, and quality management of rainfall simulation procedure a general responsibility of the rainfall simulation-community. This was accepted within the “International Rainfall Simulator Workshop 2011? at Trier University. The challenges of the present and near future use of small scale rainfall simulations concern the comparability of results and scales, the quality of the data for soil erosion modelling, and further technical developments to overcome physical limitations and constraints. The maybe most important step to a modern quality management is already realised: the initiation of a collaborative community of competent scientists of 11 countries that participated in this project.

Determination of the field‐saturated hydraulic conductivity (Kfs) can result in very high variability due to soil heterogeneity, the measurement method, the number of replications, and the Kfscalculation method used. Especially for dryland soils, stoniness can influence infiltration rates significantly. To identify this variability as well as its source, six widely used measurement methods were compared: single‐ring (SR) and double‐ring (DR) infiltrometers, the constant‐head well infiltrometer (CH), the inverse auger hole method (IA), the tension infiltrometer (TI), and the rainfall simulator (RFS). The six methods were applied at three locations in a semiarid part of Chile that showed moderate (15%) to high (55%) stoniness. Additionally, Kfsvariations due to different calculation techniques for the same measurement method were thoroughly investigated. Results showed that different calculation techniques sometimes gave significantly different estimates of Kfswhen using the same data set, and those relative differences were conserved among measurement locations. The borehole methods (IA and CH) showed high discard rates due to stoniness, making these methods less appropriate. The SR and DR methods gave considerably higher Kfsestimates, while the RFS and TI proved good candidates as reference methods for stony soils, with low failure rates and coefficients of variation.

Although both aboveground and belowground components of vegetation act together in reducing soil erosion, mainly the aboveground component has received attention in past research. The aim of this study was to evaluate the contribution of roots in soil erosion control and the effect of root density in soil erodibility and soil physical properties. Perennial ryegrass (Lolium perenneL. Hugo) was grown in soil pans, and laboratory rainfall simulation experiments were conducted after 4, 8, 12 weeks of their growth with seeding density of 50 kg ha−1, after 4 weeks for seeding density of 100 kg ha−1, and on a control. The experiments with ryegrass were done in the presence of complete plants and after clipping off the shoots. Roots of ryegrass grew rapidly, attaining densities of 0.614 kg m−2and 2.280 kg m−2in 4 and 12 weeks, respectively. With increasing root density, splash and wash decreased exponentially. There was positive correlation between soil shear strength and root density, but no influence of roots on bulk density and saturated hydraulic conductivity was observed.

Soil erosion processes are affected by the erodibility of the soil and by the erosivity of the rain. The effects of rain characteristics and invariant soil properties such as texture and organic matter content on soil erosion processes are well documented. The effect of antecedent soil water content (θa) on aggregate breakdown, seal formation, and subsequent soil erosion is much more disputable, however, as opposing effects have been reported. We conducted lab experiments with a rainfall simulator on a Belgian silt loam soil. The objectives were to determine the effect of θaon seal formation, runoff, and soil loss and to evaluate its effect on an empirical sediment transport equation. Air‐dried soil aggregates were subjected to θaof 0.04 (air‐dry aggregates), 0.12, and 0.19 m3m−3No runoff occurred on the soils with the highest θa, highest total runoff values were observed for intermediate θa, while intermediate amounts of total runoff were observed for the air‐dry aggregates. Soil loss, however, showed a different trend: highest values were found for the lowest θa, intermediate values for the intermediate θa, and no soil loss for the highest θaWe further observed that θahad no influence on the final runoff rates and on the final infiltration rate through the soil surface. In using a water discharge and stream power equation to predict sediment transport, the intercept and exponent of the regression equations were found to be lower for θaof 0.19 than 0.12 m3m−3, indicating decreasing erodibility with increasing θaWe therefore suggest including θaas an additional variable to assess soil erodibility in deterministic event‐based water erosion models.

Infiltration measurements in arid, stony soils are notoriously variable in visually homogeneous areas, and have been reported to be influenced by embedded stone fragments. This study aimed to identify the influence of rock fragment contents, orientation, and position within a small arid watershed on hydraulic conductivity in northern Chile. Two different measurement techniques were used, a single‐ring infiltrometer with constant ponding head and a tension infiltrometer, which were applied at both an undisturbed field site (44 locations along three transects) and on the disturbed <2‐mm soil fraction from the same locations. Variations in saturated and unsaturated hydraulic conductivities were observed when using different calculation methods, adding to the observed variability. For saturated conditions, only small differences in conductivities were observed between two calculation methods, whereas unsaturated hydraulic conductivities calculated by five different methods showed more important variations. Stone fragment content correlated significantly with both saturated and unsaturated conductivities, probably due to a positive correlation between stone content and coarse lacunar pore space. Slope orientations with higher amounts of stone fragments gave higher infiltration rates, as well as transects with steeper slopes and more, but smaller, rock fragments. When evaluating differences in infiltration rates observed along three transects in the watershed, variability could be mainly attributed to stone fragment content influences.

Background: In eukaryotes, endoplasmic reticulum stress (ERS) and the unfolded protein response (UPR) are coordinately regulated to maintain steady-state levels and activities of various cellular proteins to ensure cell survival. Objective: This review (Part I of II) focuses on specific ERS and UPR signalling regulators, their expression in the cancer phenotype and apoptosis, and proposes how their implication in these processes can be rationalised into proteasome inhibition, apoptosis induction and the development of more efficacious targeted molecular cancer therapies. Method: In this review, we contextualise many ERS and UPR client proteins that are deregulated or mutated in cancers and show links between ERS and the UPR, their implication in oncogenic transformation, tumour progression and escape from immune surveillance, apoptosis inhibition, angiogenesis, metastasis, acquired drug resistance and poor cancer prognosis. Conclusion: Evasion of programmed cell death or apoptosis is a hallmark of cancer that enables tumour cells to proliferate uncontrollably. Successful eradication of cancer cells through targeting ERS- and UPR-associated proteins to induce apoptosis is currently being pursued as a central tenet of anticancer drug discovery.

Background: Endoplasmic reticulum stress (ERS), the unfolded protein response (UPR) and apoptosis signal transduction pathways are fundamental to normal cellular homeostasis and survival, but are exploited by cancer cells to promote the cancer phenotype. Objective: Collateral activation of ERS and UPR role players impact on cell growth, cell cycle arrest or apoptosis, genomic stability, tumour initiation and progression, tumour aggressiveness and drug resistance. An understanding of these processes affords promising prospects for specific cancer drug targeting of the ERS, UPR and apoptotic pathways. Method: This review (Part II of II) brings forward the latest developments relevant to the molecular connections among cell cycle regulators, caspases, NF-κB, and the proteasome with ERS and UPR signalling cascades, their functions in apoptosis induction, apoptosis resistance and oncogenesis, and how these relationships can be exploited for targeted cancer therapy. Conclusion: Overall, ERS, the UPR and apoptosis signalling cascades (the molecular therapeutic targets) and the development of drugs that attack these targets signify a success story in cancer drug discovery, but a more reductionist approach is necessary to determine the precise molecular switches that turn on antiapoptotic and pro-apoptotic programmes.

One of the most important problems in the Loess Plateau of China affecting sustainable agriculture is inefficient nutrient use. Field experiments were conducted to study the effects of different soil management practices on the nitrogen (N) dynamics and winter wheat yield on a loess soil in Luoyang, Henan province, China. The results showed that subsoiling with mulch (SS) consistently increased the yield of winter wheat primarily by better water harvest compared with conventional tillage (CT). The influence on yield of no till with mulch (NT) depended on the amount of precipitation. TC (2 crops per year) lowered the winter wheat yield mainly due to the unfavourable soil moisture conditions after growing peanut in summer; however, the harvested peanut gained an extra profit for the local farmer. N uptake by grain and straw and N export was highest for SS. Changes in frequency and intensity of tillage practice altered soil total N content and its distribution along the slope. SS and NT increased the N content of the surface layer (0–0.20 m) compared with CT, but there was no significant effect in deeper soil layers. Considerable amounts of nitrate-N were left in the profile 0–1.60 cm just after harvest under all treatments. The cumulative nitrate-N content to a depth of 1.60 m on average was 282 kg/ha, of which 56 kg/ha was in the layer 1.20–1.60 m, which is an indication of considerable nitrate leaching. From data of 7 consecutive years between 1999 and 2006, it could be concluded that SS resulted in the highest yield and total N content in the surface layer, and is the most sustainable tillage option for the circumstances of the study area.

Compost and other organic amendments have been proven to improve the soil physical quality. In Flanders, vegetable, fruit and garden (VFG) wastes are collected selectively and composted. We studied the effects of the combined application of three different doses of VFG compost and cattle slurry and one treatment with only mineral N applied, during 9 years on a range of soil physical properties: aggregate stability, saturated hydraulic conductivity, bulk density, total pore volume and soil moisture retention. The organic amendments had a significantly beneficial impact (p<0.05) on all soil physical properties, except for the soil moisture retention which was hardly influenced by any of the treatments. The combined application of VFG compost and cattle slurry resulted in the best soil physical conditions. No significant differences were found in soil physical parameters between the unfertilized plots and plots that were fertilized with mineral N.

Erosion and loss of organic carbon (OC) result in degradation of the soil surface. Rill and interrill erosion processes on a silt loam soil were examined in laboratory rainfall and flume experiments. These experiments showed that rill and interrill erosion processes have contrasting impacts on enrichment of OC in transported sediment. Rill erosion was found to be nonselective, while for interrill erosion the enrichment ratio of OC, EROC, varied between 0.9 and 2.6 and was inversely related to the unit sediment discharge. At unit sediment discharge values >0.0017 kg s−1m−1, the EROCremained equal to 1. The enrichment process was not influenced by raindrop impact. Enrichment of OC by “aggregate stripping” was found to be unimportant in our study. This was attributed to the low aggregate stability of the soil and the equal distribution of OC within the different soil aggregate classes.

Artificial Neural Network models (ANNs) were used to predict habitat suitability for 12 macroinvertebrate taxa, using environmental input variables. This modelling technique was applied to a dataset of 102 measurement series collected in 31 sampling sites in the Greek river Axios. The database consisted of seven physical-chemical and seven structural variables, as well as abundances of 90 macroinvertebrate taxa. A seasonal variable was included to allow the description of potential temporal changes in the macroinvertebrate communities. The induced models performed well for predicting habitat suitability of the macroinvertebrate taxa. Senso-nets and sensitivity analyses revealed that dissolved oxygen concentration and the substrate composition always played a crucial role in predicting habitat suitability of the macroinvertebrates. Although ANNs are often referred to as black box prediction techniques, it was demonstrated that ANNs combined with sensitivity analyses can provide insight in the relationship between river conditions and the occurrence of macroinvertebrates, and thus deliver new ecological knowledge. Consequently, these models can be useful in decision-making for river restoration and conservation management.

A crucial parameter in predicting wind erosion is the deflation threshold shear velocity, which is highly dependent on near‐surface soil water. The empirical and theoretical models to predict the deflation threshold as affected by near‐surface water that have been reported in literature all suffer from a weak physical background and very large differences between the predicted results can be observed. The present study was conducted to develop a new conceptual model to predict the deflation threshold as affected by near‐surface wetness and to contribute to a better understanding of the role of the latter on deflation of sediment. The model was developed by solving the moment balance equation for entrainment of soil particles by wind, including the moments associated with drag forces, lift forces, aerodynamic moment forces, gravitational forces, and interparticle forces due to dry and wet bonding. The wet bonding force, which represents the effect of near‐surface soil water, is due to liquid bridge bonding or capillary forces, and adsorbed layer bonding or adhesive forces. It was related to the particle diameter squared, surface tension squared and the inverse of matric potential. The latter was then converted to water content by assuming a logarithmic relationship, which was shown to be valid between oven dryness and a matric potential of −1.5 MPa, a range that is of interest in the light of deflation of soil particles by wind. The conceptual model presented in this paper is relatively simple and predicts, for a given particle diameter and surface tension, the deflation threshold shear velocity as a function of the ratio between water content and the water content at a matric potential of −1.5 MPa.

Although transport of sediment under wind‐driven rains is generally not accounted for in equations for sediment transport by wind, the contribution of this rainsplash–saltation process can be substantial. Wind‐tunnel experiments, in which vertical deposition fluxes were measured at 23 distances from a sand tray, were conducted to study sediment transport under wind‐driven rain and rainless wind conditions. It was shown that the vertical deposition flux could be described by a double exponential equation. By integration of the vertical deposition flux over the distance of deposition, the sediment transport rate was computed. A power‐law function including both the normal component of the kinetic energy or momentum of the raindrops and the wind shear velocity was presented. However, including the wind shear velocity in the equation increased the model performance only slightly. When comparing the sediment transport rates as determined under the wind‐driven rain events with those that were observed when rain was absent, it was shown that in the latter case, the transport rate is much higher at high wind shear velocities. However, at low wind shear velocities and moisture conditions where no motion is predicted by aeolian equations, saltation due to rainsplash is likely to occur and can be predicted with the presented model.

A wind tunnel study was carried out to evaluate the effect of successive windscreens perpendicular to the wind direction on wind speed reduction. Two types of windscreens, differing in essence only in open area, were used in the experiments. Their open areas were respectively 35·7 and 57·5%. The windscreens were modelled in a wind tunnel and had a height H of 10 cm. Experiments were carried out with two and three consecutive screens of the same nature. Both screen types were used in the experiments with two consecutive screens at a mutual spacing of 24 H while the less-open windscreen was also used in experiments with two and three consecutive screens at a spacing of 12 H. A free wind speed of 6·7 m s−1was applied during the tests. Wind speed was measured midway between the tunnel walls with vane probes at one location windward and various locations downwind of the first screen. For each location, wind speed was measured at four heights above the bottom surface.The wind tunnel study illustrates clearly that the extension of the lee zone, when two successive screens are used instead of one, depends on the recovery of the wind speed reduction at the second screen. It is about half the screen spacing when the second screen is placed where the wind speed recovery is 0% or where the wind speed is minimum. The extension increases to about one screen spacing when the screen is placed where the wind speed recovery is about 60%. The extension of the lee zone when three screens are installed, also depends on the locations of the second and third screens with respect to the recovery of the wind speed. Furthermore, it follows that the type of screen has little or no effect on the lee distance where the wind velocity has recovered between 60 and 70%.A second screen placed downwind of the first where the maximum wind speed reduction occurs, is less effective than when it is placed where the wind speed is already recovering. Consequently, successive screens should not be spaced too closely in order to be most effective.

This study examines the relationship between children's abilities to perceive their symptoms of asthma via several previously researched subjective and objective procedures compared with their performance on a standardized children's drawing task and scale criteria. Results indicated that girls verbalized significantly more emotions about their drawings and were better able to detect airflow changes in their small airways than boys. The Gabriels Asthma Perception Drawing Scales (GAPDS) is a promising clinical tool for assessing children's perceptions and emotions about asthma via nonverbal methods. Varying methods of measuring asthma symptom awareness are not highly correlated; thus, more than one methodology is appropriate for use with children.

AbstractTo evaluate if the adaptation of the basically two-dimensional Revised Universal Soil Loss Equation (RUSLE) to a three-dimensional reality is appropriate far predicting off-site sediment accumulation, it was extended with the Monte Carlo error propagation technique. This technique generates the true probability distribution of model output and gives the possibility to explain whether the difference between the model output and the field observations is largely due to the uncertainty of the model input or is mainly due to the uncertainty and limitations of the model itself. It was found that the RUSLE was able to accurately predict off-site sediment accumulation in the water reservoir of a study area. The value of the measured sediment input was within the 68% confidence interval around the predicted value, with a difference of only 1.4%. Therefore, the error propagation explained this difference as mainly due to the uncertainty of the model input parameters. Consequently it can be concluded that the topographic factor of the RUSLE model also can be considered as a measure of the sediment transport capacity of the overland flow, although it was originally developed far situations where detachment limits the sediment load.

A plethora of proteomics search engine output file formats are in circulation. This lack of standardized output files greatly complicates generic downstream processing of peptide-spectrum matches (PSMs) and PSM files. While standards exist to solve this problem, these are far from universally supported by search engines. Moreover, software libraries are available to read a selection of PSM file formats, but a package to parse PSM files into a unified data structure has been missing. Here, we present psm_utils, a Python package to read and write various PSM file formats and to handle peptidoforms, PSMs, and PSM lists in a unified and user-friendly Python-, command line-, and web-interface. psm_utils was developed with pragmatism and maintainability in mind, adhering to community standards and relying on existing packages where possible. The Python API and command line interface greatly facilitate handling various PSM file formats. Moreover, a user-friendly web application was built using psm_utils that allows anyone to interconvert PSM files and retrieve basic PSM statistics. psm_utils is freely available under the permissive Apache2 license at https://github.com/compomics/psm_utils.

The pandemic readiness toolbox needs to be extended, targeting different biomolecules, using orthogonal experimental set-ups. Here, we build on our Cov-MS effort using LC–MS, adding SISCAPA technology to enrich proteotypic peptides of the SARS-CoV-2 nucleocapsid (N) protein from trypsin-digested patient samples. The Cov2MS assay is compatible with most matrices including nasopharyngeal swabs, saliva, and plasma and has increased sensitivity into the attomole range, a 1000-fold improvement compared to direct detection in a matrix. A strong positive correlation was observed with qPCR detection beyond a quantification cycle of 30–31, the level where no live virus can be cultured. The automatable sample preparation and reduced LC dependency allow analysis of up to 500 samples per day per instrument. Importantly, peptide enrichment allows detection of the N protein in pooled samples without sensitivity loss. Easily multiplexed, we detect variants and propose targets for Influenza A and B detection. Thus, the Cov2MS assay can be adapted to test for many different pathogens in pooled samples, providing longitudinal epidemiological monitoring of large numbers of pathogens within a population as an early warning system.

Sizedistribution of eroded materials has implications in deposition mechanics and in carrying capacity for pollutant materials. Dispersed clay stays in suspension virtually as long as water is moving. This dispersed clay, especially the expanding lattice types, has a high carrying capacity for pollutant materials. The aggregated materials high in clay settle according to their size and density. Their carrying capacity for pollutants is assumed to be much greater than that of single‐grained materials of the same size. Studies of the carrying capacities of the various sizes and compositions of aggregates are in progress. The present study reports size distributions and composition of material detached by water drops and transported in shallow flow. The size distributions of aggregates and primary particles in the splashed, washed, and seal material at different times during a laboratory simulated rainfall were compared for different textured soils. The wash had more finer material than did the splash. The wash and splash material at equilibrium were not different from the original soil, while the seal of all soils had a larger silt content than the original soils. The silt loam soil had seals with about the same clay content as the original soil, while silty clay soils had seals with less clay than the original soils. Of significance from this study is the low percentage of dispersed clay being eroded compared to the percent of clay in the original soil and that this percentage didn't change significantly with time. The most striking differences were between soils and these were influenced mainly by texture and aggregate condition of the original soils.

Dune sand was subjected to a range of rain intensities (6.5–64.5 mm/hr) using a rainfall simulator. A linear relationship was found between the side splash erosion and the kinetic energy of the rainfall.

Changes in redox potential, soil gas composition (O2and CO2), and oxygen diffusion rate were studied in laboratory soil columns in the presence of different stagnating groundwater tables. Under steady-state moisture conditions, a decrease in O2content was reflected by an increase in CO2content. The redox potential was related to the soil pH. The oxygen diffusion rate increased when the water table was lowered. Only at water table depths of more than 50 cm did the oxygen diffusion rate at the 5-cm soil depth exceed the level at which aeration is considered sufficient to sustain vigorous rooth growth.

Brominated poly(dG-dC) . poly(dG-dC), which forms a stable Z-DNA helix under physiological salt conditions, was used as an antigen to produce monoclonal antibodies from mice. The anti-Z-DNA antibodies were specific for the Z conformation as was shown by direct binding studies and a competitive solid phase assay. Competition could only be seen by brominated poly(dG-dC) . poly(dG-dC) under low and high salt conditions and unmodified poly(dG-dC) . poly(dG-dC) under high salt conditions. No binding could be seen to a number of other polynucleotides, including native and denatured DNA. Among the anti-Z-DNA monoclonal antibodies, examples differed in specificity: binding of one monoclonal antibody was blocked by methylation of cytosine; whereas the other antibody reacted equally well with the unmodified polymer or methyl cytosine-containing polymer in high ionic strength. The two antibodies are specific for different localized features of Z-DNA structure.

The speed and direction of displacement of individual eyebrow-shaped dunes (barkhans) was monitored at two experimental stations (Menzel El Habib and Noueil) in southern Tunisia. The displacement of the barkhans was followed from 1 June 1992 until 31 May 1993. After 1 year the barkhan at Noueil had moved 51 m in the southwest direction and the barkhan at Menzel El Habib had moved 48.5 m further westward (west by southwest). The dominant active winds with windspeeds higher than 3ms-1 sms1 were coming from east, southeast, and north. Hence the barkhans migrated in the direction of the Sahara and in particular to the Erg Oriental. The desertification process along the border of the Sahara was not due to sand movement coming from the Sahara, but resulted from a disequilibrium of the ecological system.

Chemicals were sprayed on large dry surface clods (8 to 20 mm) and small surface clods (2 to 8 mm) of a Clarion loam to test their effectiveness in preventing erosion during rainfall. The small clods were initially wetted with 15% water on a soil weight basis and mixed with bitumen emulsions. The large and small clods were subjected to a 6.35‐cm‐per‐hour simulated rainfall under controlled conditions in the laboratory. Simultaneously with the measurements of infiltration rate, determinations were made of (i) the starting time for initial runoff, (ii) energy needed to initiate runoff, (iii) runoff rate, (iv) total soil loss, and (v) final soil loss rate. Surface applications of most of the soil conditioners on large clods applied at high enough rates kept the infiltration rate high and prevented runoff on a 9% slope. Polyvinyl alcohol and polyacrylamide prevented any soil loss during 90 min. Surface applications with bitumen emulsions were also highly effective in preventing erosion of large clods but were less effective for small clods. When the bitumen emulsions were mixed with the small clods, the saturated hydraulic conductivity was very high. The infiltration rate was low because water would not enter the clod bed and stable clods were carried in the runoff water.